[{"id":10,"title":"Decoupling the CT Paradigm in Membrane Chlorination: Equivalent Versus Inequivalent Impacts of Hypochlorite Concentration and Exposure Time on Contaminants Rejection.","authors":"Su, Wenhao; Yao, Keyu; Li, Jiaxing; Xing, Dingyu; Qiu, Jianhua; Li, Wanbin; Guo, Hao","year":2026,"date":"2026 Aug 18","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"CT (i.e., hypochlorite concentration C × exposure time T) value, borrowed from water disinfection that assumes the equivalent contribution of C and T, is widely used to indicate membrane chlorination intensity. Although intentional chlorine treatment is commonly applied to polyamide nanofiltration membranes for surface modification or fouling control, whether C and T play equivalent roles in membrane rejection of diverse contaminants, such as per- and polyfluoroalkyl substances (PFASs), antibiotics, and endocrine disrupting compounds (EDCs), remains unclear. Herein, we investigated the impacts of C and T on contaminant rejection across CT values of 1000-20,000 ppm × h. Results reveal near-equivalent effects on the rejection of PFASs and antibiotics at low chlorination intensities (e.g., ≤ 2000 ppm × h), but significantly inequivalent impacts on the rejection of all contaminants at higher intensities (e.g., CT ≥ 10,000 ppm × h). High-C chlorination induced more severe polyamide degradation than long T chlorination, drastically compromising contaminant rejection (e.g., sulfadiazine rejection of 98.2% vs 59.3% for membranes chlorinated at 2000 ppm × 10 h and 20,000 ppm × 1 h, respectively). Based on these results, a conceptual framework was established to decouple the traditional CT paradigm, revealing the fundamental mechanisms of chlorination-induced changes in membrane rejection.","pmid":"42611467","doi":"10.1021/acs.est.6c05663","url":"https://pubmed.ncbi.nlm.nih.gov/42611467/"},{"id":11,"title":"An oligothiophene-based \"turn-on\" fluorescent probe: Ultrasensitive detection and bioimaging of hypochlorite in environmental and living systems.","authors":"Liang, Limin; Li, Baokun; Jin, Zichen; Hu, Tingting; Wei, Tao; Niu, Qingfen","year":2027,"date":"2027 Jan 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorite (ClO(-)) is widely used for disinfection and sterilization but its overuse poses risks to environmental and food safety as well as human health. Developing effective detection tools is therefore of great importance. Herein, we report an oligothiophene-based fluorescent probe 2TS for ClO(-) detection in environmental and biological samples. 2TS exhibits a highly specific \"turn-on\" fluorescence response to ClO(-) with rapid response (<10 s), excellent sensitivity (LOD = 6.3 nM), good photostability (≥6 h), and wide pH tolerance (4-10). 2TS not only permits sensitive and quantitative ClO(-) determination in water, bleach, disinfectant, and soil matrices with satisfactory recoveries (97.20-102.20%), but also facilitates on-site visual detection of ClO(-) in fresh produce, thereby contributing to food safety monitoring. 2TS-loaded test strips allow rapid naked-eye detection of ClO(-) in aqueous media, and smartphone-assisted RGB analysis further provides instrument-free quantitative detection on food surfaces and test strips. Moreover, its good biocompatibility enables real-time bioimaging of ClO(-) in living cells, onion tissues, and zebrafish. This work offers a simple and effective fluorescent tool for visual monitoring and bioimaging of ClO(-) in diverse environmental and biological systems.","pmid":"42600306","doi":"10.1016/j.saa.2026.128600","url":"https://pubmed.ncbi.nlm.nih.gov/42600306/"},{"id":12,"title":"Validation of digital PCR as a complementary tool to MS2 plaque assay for virucidal activity assessment.","authors":"Kim, Sung Jae; Yang, Song Yi; Song, Min Sik; Kim, Cheong Ung; Park, Yong Ho; Jung, Woo Kyung; Lee, Jae Myun; Chung, Hee Chun","year":2026,"date":"2026","journal":"Frontiers in public health","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"INTRODUCTION: Bacteriophage MS2 is widely applied as a surrogate for pathogenic non-enveloped RNA viruses that are difficult to culture. However, standardized approaches for evaluating disinfectant efficacy using MS2 remain limited. This study aimed to validate dPCR as a rapid quantitative complement to the previously established MS2 plaque assay, assessing their concordance in disinfectant efficacy testing using a previously established double-layer protocol. METHODS: A previously established double-layer MS2 plaque assay was employed. Disinfectant efficacy was tested against two widely used agents-70% ethanol and 60 ppm hypochlorous acid (HOCl)-according to the Korean Disinfectant Efficacy Test Guideline. Viral reduction was determined by plaque counts and further quantified by dPCR following RNase treatment to eliminate free RNA. Agreement between the established plaque assay and dPCR was evaluated using regression and Bland-Altman analyses. RESULTS: Treatment with 70% ethanol yielded only partial inactivation, with a 2.43-log10 reduction, below the ≥4-log10 benchmark for virucidal efficacy. In contrast, 60 ppm HOCl achieved a 4.38-log10 reduction, confirming effective MS2 inactivation. The dPCR counts correlated strongly with plaque counts (R = 0.999), and Bland-Altman analysis demonstrated excellent agreement within 95% confidence limits, supporting dPCR as a practical alternative to plaque assays. However, the reliability of dPCR as a proxy at low viral concentrations near the limit of detection (<10(2) PFU/mL) requires further validation. CONCLUSION: This study successfully validated dPCR as a rapid quantitative complement to the previously established MS2 double-layer plaque assay, demonstrating its utility in disinfectant efficacy testing. The findings confirm ethanol's limited virucidal capacity against MS2 and HOCl's effectiveness at low concentrations. These results establish dPCR as a promising molecular tool that complements plaque assay results for comprehensive viral surrogate evaluation in disinfection studies.","pmid":"42577465","doi":"10.3389/fpubh.2026.1850944","url":"https://pubmed.ncbi.nlm.nih.gov/42577465/"},{"id":15,"title":"New design of a chimeric enzyme based on vanadium-dependent bromoperoxidase and glucose oxidase to highlight the microbicidal properties of the reaction products: HOBr and HOCl.","authors":"Amalric, Valentin; Gounel, Sébastien; Thureau, Aurélien; Pécastaings, Gilles; Branham, Paul J; Agarwal, Vinayak; Stines-Chaumeil, Claire","year":2026,"date":"2026 Nov","journal":"Journal of biotechnology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Vanadium-dependent haloperoxidases are enzymes found in bacteria, fungi and red or brown macroalgae. They are used as a defense system for the latter by producing bromoform. The intermediate product, HOBr or HOCl, is also a microbicidal compound that can be exploited in many domains as medical tools or disinfectant sprays for example. We show that the mutation identified in Ohshiro's work, which alters substrate specificity toward chloride, is transferable to the homologous enzyme from Chondrus crispus. We then applied genetic and enzymatic engineering to design a chimera with glucose oxidase, thereby enhancing antimicrobial properties by providing a local source of H(2)O(2). We used the SpyTag/SpyCatcher technology to form the chimera and obtained homogenous objects, indicating that one oligomeric form is favored. We demonstrated the release of HOBr and HOCl thanks to NADH that reacts spontaneously with it outside the active site of the enzyme. We also measured the steady-state kinetic parameters of the wild-type or modified enzymes. The formation of the chimera increased the specificity of ccVHPO1 inside the chimera, towards KBr or H(2)O(2), compared to the enzyme alone with the SpyCatcher. Finally, we showed a significant increase in the microbicidal effect between a coupled enzymatic system with the glucose oxidase (the two enzymes are free in solution) compared to the chimera system, which is completely bactericidal at concentrations around 20 nM.","pmid":"42567274","doi":"10.1016/j.jbiotec.2026.08.002","url":"https://pubmed.ncbi.nlm.nih.gov/42567274/"},{"id":20,"title":"Hypochlorite detection via the irreversible imine-bond cleavage by a practical fluorescent sensor: applications to smartphone-assisted environmental water and food bioimaging.","authors":"Lee, Ayin; Batsaikhan, Otgontsetseg; Lee, Han-Seul; Kim, Ki-Tae; Kim, Cheal","year":2026,"date":"2026 Oct 5","journal":"Bioorganic chemistry","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Abnormally high levels of hypochlorite (ClO(-)) can cause serious damage to environmental and biological systems, thereby highlighting the necessity for detectors capable of sensitive monitoring and quantification of ClO(-) in these systems. In this study, we synthesized and evaluated a practical and portable fluorescent turn-off sensor, BHMT-Cl ((E)-2-(2-(3-(benzo[d]thiazol-2-yl)-2-hydroxy-5-methylbenzylidene)hydrazineyl)-N,N,N-trimethyl-2-oxoethan-1-aminium chloride), for the detection of ClO(-). BHMT-Cl exhibited selective and sensitive detection of ClO(-) in pure water via a green fluorescence turn-off, with a critically low detection limit of 2.78 μM. The sensing mechanism was elucidated to involve the cleavage of the imine bond in BHMT-Cl, supported by (1)H NMR titration, ESI-mass analysis, FT-IR and DFT calculations. BHMT-Cl was readily applied for the sensitive detection and quantification of ClO(-) in diverse environmental water samples and demonstrated portability through smartphone-based analysis and test kits. In biological applications, BHMT-Cl enabled bioimaging of ClO(-) in zebrafish as well as in fungal and plant systems, confirming its broad applicability. Overall, BHMT-Cl showed strong potential as a versatile tool for monitoring ClO(-) in biological and environmental matrix.","pmid":"42556267","doi":"10.1016/j.bioorg.2026.110331","url":"https://pubmed.ncbi.nlm.nih.gov/42556267/"},{"id":21,"title":"HYPOChLorous Acid TEsting Studies in percutaneous DRAINAGE (HYPOCLATES:DRAINAGE): protocol for a single-centre, controlled, ambispective cohort study comparing hypochlorous acid versus saline irrigation in percutaneous drainage of intra-abdominal abscesses.","authors":"Nadvornik, Mika P; Hoch Al Hessen, Tobias; Siegel, Niels; Kramer, Axel; Harnoss, Jonathan M; Probst, Pascal; Al-Saeedi, Mohammed; Klauss, Miriam; Loos, Martin; Michalski, Christoph W; Harnoss, Julian C","year":2026,"date":"2026 Jul 29","journal":"BMJ open","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"INTRODUCTION: Percutaneous drainage is the standard of care for intra-abdominal abscesses. Additional saline irrigation provides mechanical cleansing but lacks antimicrobial activity. Hypochlorous acid (HOCl), an endogenous antiseptic with broad-spectrum microbicidal activity and high tissue compatibility, is a promising alternative for intracavitary infection control. This study evaluates whether HOCl irrigation shortens the indwelling time of percutaneous irrigation drains and systemic antibiotic duration compared with saline irrigation in patients with intra-abdominal abscesses. METHODS AND ANALYSIS: Following an institutional change in routine practice on 1 December 2025, this single-centre, controlled, ambispective cohort study at the Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, compares a prospectively followed cohort treated with continuous HOCl-containing irrigation (Granudacyn) with a non-concurrent, retrospectively assembled saline cohort from the preceding period. Both cohorts include drains managed with continuous high-volume irrigation (at least 1 L per 24 h for a minimum of 3 consecutive days). The primary endpoints are the indwelling time of the index irrigation drain (placement to removal) and the duration of systemic antibiotic therapy. Secondary endpoints include hospital and intensive care unit stay, reinterventions, complication severity (Clavien-Dindo), time to fistula closure and infection-related parameters. Confounding is addressed using propensity-score methods, and time-to-event endpoints are analysed accounting for competing events. ETHICS AND DISSEMINATION: The study has received ethical approval from the Ethics Committee of Heidelberg University's Medical Faculty (S-520/2025). As pseudonymised routine clinical data are used without additional patient contact or deviation from standard care, individual informed consent is waived in accordance with the national regulations and General Data Protection Regulation. Study findings will be disseminated through peer-reviewed publications. TRIAL REGISTRATION NUMBER: DRKS00038653.","pmid":"42526920","doi":"10.1136/bmjopen-2026-117218","url":"https://pubmed.ncbi.nlm.nih.gov/42526920/"},{"id":23,"title":"Bactericidal and anti-inflammatory activity of defined hypochlorite solution.","authors":"Chapman, Christopher David; Dakin, Myles Hyla Edward; Aspinall, Richard","year":2026,"date":"2026","journal":"PloS one","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"BACKGROUND: Hypochlorite is an antiseptic that has been used for over a century for industrial sterilisation and antisepsis. More recently, the topical application of hypochlorite to severe burn patients increased their rate of survival post infection with Gram-negative bacteria, of which antisepsis cannot be solely responsible. METHODOLOGY: Broth microdilution experiments were performed to confirm anti-microbial activity. Cytokine exposure was performed by dialytic exposure of serum spiked with either interleukin-6 or interleukin-10, accounting for contextually appropriate organic load. Cytokine degradation was measured by immunoassay and by functional bioassay utilising HEK-Blue cells. Hypochlorite mediated cytotoxicity against dermal cells was assessed via direct exposure, followed by a 1-hour attenuation period. Resazurin was utilised to assay the impact of hypochlorite on cell viability. RESULTS: We have shown that this formulation of hypochlorite in isotonic saline has multiple mechanisms. The first is that 7 mmol/L hypochlorite is capable of eliminating both Gram-negative and Gram-positive bacteria, and that the same concentration differentially degrades the function of IL-6 and IL-10. IL-6 was seen to be 3 times more susceptible to loss of function than IL-10 after only 5 minutes of exposure (P < 0.005). The asymmetrical effect on these cytokines was observed between 7 and 1.75 mmol/L, and across the entire time scale examined. This hypochlorite formulation has the capability to sterilize a wound, and by altering the cytokine profile reduce inflammation and scarring, and improve wound healing. CONCLUSIONS: These findings, taken with the burn survival study, suggest that the increased survival rate after application of hypochlorite could be due to the combined effect of elimination of infective pathogens, and the differential degradation of interleukin-6 and interleukin-10 at the site of injury.","pmid":"42497178","doi":"10.1371/journal.pone.0352576","url":"https://pubmed.ncbi.nlm.nih.gov/42497178/"},{"id":25,"title":"Boranil-phenothiazine conjugates with dual-state emission for ratiometric tracking of HClO in food samples and injured liver cells.","authors":"Hai, Xue; Zhao, Yucheng; Meng, Xinjia; Jiao, Junrong; Zhang, Jian; Shao, Xiangmin; Wang, Jianhong; Wang, Jiamin","year":2026,"date":"2026 Dec 15","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HClO) is applied as a disinfectant in food processing and sanitation, while excessive residues may pose potential risks to food safety and human health. Therefore, the development of sensitive, rapid, and reliable analytical methods for HClO detection is of considerable importance. Herein, an innovative donor-acceptor (D-A) fluorophore, HC-SN, formulated from an asymmetric phenothiazine-boron difluoride complex, is developed for ratiometric sensing and imaging of HClO. Owing to its significantly twisted molecular structure, HC-SN effectively suppresses π-π stacking and exhibits prominent dual-state emission characteristics, achieving exceptional photoluminescence quantum efficiencies across both solvated and solid phases. Upon the HClO-triggered specific oxidation of the thioether moiety, the intramolecular charge transfer (ICT) process is modulated, leading to a distinct ratiometric fluorescence response accompanied by a significant hypsochromic shift in the emission spectrum. The probe displays excellent analytical performance, featuring remarkable specificity, ultrafast reaction kinetics (under 30 s), and an ultrasensitive detection threshold of 66.87 nM. In addition, HC-SN permits accurate quantification of HClO in food-related liquid samples and was fabricated into fluorescent test strips for naked-eye screening. Importantly, its applicability is further demonstrated by an acetaminophen-induced liver injury cell model. These results suggest that HC-SN provides a practical and versatile platform for HClO monitoring in food safety analysis and related biological systems.","pmid":"42480401","doi":"10.1016/j.saa.2026.128473","url":"https://pubmed.ncbi.nlm.nih.gov/42480401/"},{"id":27,"title":"HYPOChLorous Acid TEsting Studies in secondary peritonitis (Hypoclates:Peritonitis): extended hypochlorous acid versus isotonic lavage for the prevention of surgical site infections in secondary peritonitis in Germany - protocol for a sequential, quasi-experimental cohort study.","authors":"Hoch Al Hessen, Tobias; Siegel, Niels; Nadvornik, Mika P; Kramer, Axel; Harnoss, Jonathan M; Probst, Pascal; Al-Saeedi, Mohammed; Loos, Martin; Michalski, Christoph W; Harnoss, Julian C","year":2026,"date":"2026 Jul 15","journal":"BMJ open","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"INTRODUCTION: Surgical site infections (SSIs) impose a significant clinical and economic burden on the healthcare systems. To date, traditional preventive strategies have frequently failed to demonstrate definitive efficacy. Hypochlorous acid (HOCl) has emerged as a compelling antimicrobial alternative, characterised by potent microbicidal properties and excellent biocompatibility. Hypoclates:Peritonitis investigates the clinical impact of an HOCl-based lavage strategy in patients undergoing surgical treatment for secondary peritonitis. The trial evaluates the primary endpoint of postoperative SSI incidence up to day 10 (±2 days), hypothesising that the antimicrobial and biocompatible properties of HOCl significantly lower infection rates compared with standard isotonic lavage. METHODS: Using a sequential, quasi-experimental design, this mono-centric study assesses the clinical impact of adopting an intensified, multi-day HOCl-lavage protocol (Granudacyn) for patients with secondary peritonitis. We will compare a prospective intervention group (n≈100) against a preceding cohort of equal size that received standard isotonic irrigation. The primary endpoint is defined as the frequency of SSIs-inclusive of superficial, deep and organ/space infections according to Centers for Disease Control and Prevention criteria-monitored through hospital discharge or up to postoperative day 10 (±2 days). Secondary evaluative measures include the length of intensive care unit and total hospital stay, the duration of postoperative antibiotic therapy and the cumulative morbidity burden as calculated by the Comprehensive Complication Index. ETHICS AND DISSEMINATION: Ethical clearance for this trial was provided by the Institutional Review Board of the Medical Faculty of Heidelberg University (S-523/2025). To facilitate knowledge transfer and evidence-based practice, the study results will be presented at international scientific meetings and published in peer-reviewed journals, thereby contributing to the refinement of SSI prevention protocols in emergency visceral surgery. TRIAL REGISTRATION NUMBER: German Clinical Trials Register (DRKS), DRKS00038630.","pmid":"42457415","doi":"10.1136/bmjopen-2026-119499","url":"https://pubmed.ncbi.nlm.nih.gov/42457415/"},{"id":32,"title":"A novel borondifluoro indolenine-functionalized red-shift ratiometric fluorescent probe for detection of hypochlorous acid in drug-induced liver injury.","authors":"Yang, Linlin; Wang, Guangnian; Xin, Fei; Xie, Fan; Wang, Chenhan; Cui, Shaoli; Li, Lili; He, Guangjie; Ren, Wenjie","year":2027,"date":"2027 Jan 1","journal":"Talanta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The diagnosis of drug-induced liver injury (DILI) remains a significant clinical challenge due to the lack of reliable tools for visualizing related biomarkers in vivo. Hypochlorous acid (HClO), a key indicator of oxidative stress, has been demonstrated to be closely linked to the onset and progression of DILI. Herein, to address the limitations of conventional HClO/ClO(-) detection, we developed a D-π-A architecture probe BFI-Naph through rational molecular engineering of a borondifluoro indolenine (BFI) core and a naphthol group. The probe exhibits a rapid (∼30 s), sensitive (LOD = 120 nM), large emission red-shifted (134 nm) and highly selective ratiometric fluorescence. The probe BFI-Naph was constructed based on the ClO-induced chlorination and concomitant pKa decreased mechanism. This structural and electronic adjustment enables a red shift in the fluorescence emission wavelength-from the red region toward the NIR region-upon recognition, thereby improving the accuracy of ratiometric signals in vivo. We successfully employed BFI-Naph to image endogenous HClO upregulation during APAP-induced hepatotoxicity in live cells. Most importantly, the probe enabled the clear visualization of elevated HClO levels in DILI and OA models. This study not only provides a powerful optical tool for the diagnosis and mechanistic investigation of DILI but also offers a versatile design strategy for developing precision biosensors.","pmid":"42391699","doi":"10.1016/j.talanta.2026.130225","url":"https://pubmed.ncbi.nlm.nih.gov/42391699/"},{"id":34,"title":"Hypochlorous acid testing studies: elective surgeries (Hypoclates:Elective).","authors":"Hoch Al Hessen, Tobias; Siegel, Niels; Nadvornik, Mika P; Kramer, Axel; Harnoss, Jonathan M; Probst, Pascal; Al-Saeedi, Mohammed; Loos, Martin; Michalski, Christoph W; Harnoss, Julian C","year":2026,"date":"2026 Jun 29","journal":"BMJ open","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"INTRODUCTION: Surgical site infections (SSI) impose a substantial clinical and economic burden on healthcare systems, accounting for approximately 15% of nosocomial infections. While intraoperative lavage is predominantly performed with isotonic solutions, its efficacy in preventing SSI remains unproven. Hypochlorous acid (HOCl) has emerged as a promising antimicrobial agent due to its potent microbicidal properties and high biocompatibility. The primary objective of this study is to evaluate whether the systematic introduction of a standardised intraoperative lavage with HOCl reduces the incidence of SSI in patients undergoing elective visceral surgery compared with conventional irrigation with isotonic saline. It is hypothesised that the implementation of HOCl-based lavage will lead to a significant reduction in the composite rate of superficial, deep and organ/space SSIs during the immediate postoperative hospitalisation period. METHODS: This is a single-centre, prospective, sequential, quasi-experimental trial conducted at Heidelberg University Hospital. A prospective cohort of approximately 500 adult patients undergoing elective visceral surgery with HOCl-based lavage (Granudacyn) will be compared with a sequential retrospective control cohort of 500 patients treated with isotonic solution. The primary outcome is the incidence of SSI (superficial, deep or organ/space) according to Centres for Disease Control and Prevention criteria, assessed until hospital discharge or postoperative day 10 (±2 days). Secondary outcomes include length of stay in the intensive care unit and hospital, duration of antibiotic therapy and the Comprehensive Complication Index (CCI). ETHICS AND DISSEMINATION: The study protocol has been approved by the Ethics Committee of the Medical Faculty of Heidelberg University (S-522/2025). Findings will be disseminated through peer-reviewed publications and presentations at international surgical congresses to inform clinical practice and future SSI prevention guidelines. TRIAL REGISTRATION NUMBER: DRKS00038635.","pmid":"42373189","doi":"10.1136/bmjopen-2026-119500","url":"https://pubmed.ncbi.nlm.nih.gov/42373189/"},{"id":35,"title":"Unlocking HClO detection via an AIE \"off-on-off\" fluorescent switch.","authors":"Zhang, Zhixin; Wang, Xiangyi; Zeng, Xianchuan; Zhu, Yingkai; Chen, Yuping; Fan, Baolei; He, Youling; Li, Yan; Zhang, Fei; Ye, Long","year":2026,"date":"2026 Dec 15","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HClO) is a key reactive oxygen species (ROS) involved in both normal physiology and disease pathogenesis. Imbalances in its intracellular levels are strongly associated with inflammatory disorders and cancer. In this work, we introduce TPE-ML, a novel aggregation-induced emission (AIE) probe built on a thiomorpholine scaffold. This probe features a distinctive \"off-on-off\" fluorescence switching behavior. It exhibits a Stokes shift of approximately 170 nm and enables sensitive detection of HClO with a limit of detection as low as 1.37 μM. Solvent-dependent assays confirm its AIE characteristics: the fluorescence intensity increases 15-fold in solvent mixtures with 99% water fraction. Upon selective oxidation by HClO, TPE-ML converts from an AIE-active aggregated state to a dispersed state, accompanied by marked fluorescence quenching. Theoretical calculations further reveal an increased dipole moment and hydrophobicity (log P) further altered electronic properties after oxidation. Using the standard addition method, TPE-ML achieved quantitative analysis of HClO in strawberries, apples, baby cabbage, and lettuce, with spiked recoveries ranging from 98.3% to 107.8%. It also permitted on site visual monitoring, as the fluorescence turned from yellow to dark under 365 nm UV illumination. Furthermore, this probe allowed real time imaging of both externally added and endogenously produced HClO in living 4 T1 cells, underscoring its biomedical promise. Collectively, this work introduces a fresh AIE based sensing mechanism for HClO, thereby enriching the methodological toolbox for ROS detection in biological specimens.","pmid":"42372365","doi":"10.1016/j.saa.2026.128322","url":"https://pubmed.ncbi.nlm.nih.gov/42372365/"},{"id":36,"title":"From live cells to real-world samples: A PET-based ultrafast and photostable turn-on fluorescent probe for on-site quantification and in vivo visualization of HClO.","authors":"Zhang, Tieshan; Wang, Lu; Zhou, Zicheng; Zuo, Shuangmeng; Wu, Jian; Zuo, Yujing; Jiang, Pengcheng; Yu, Haitao; Qi, Yanyu","year":2027,"date":"2027 Jan 1","journal":"Talanta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HClO) plays a vital role in pathogen elimination within biological systems and water treatment processes owing to its strong oxidizing properties. Meanwhile, excessive or residual HClO may not only cause pathological damage but also pose potential threats to the environment and public health. Therefore, the detection of trace HClO in complex systems is of great significance. We designed and synthesized an ultrafast, highly photostable coumarin-based turn-on probe, CUM-DMTC. By utilizing photoinduced electron transfer (PET) quenching, it exhibits an extremely low background signal. Upon specific oxidation by HClO followed by rapid hydrolysis in PBS buffer solution, PET process is blocked, leading to fluorescence recovery with over 100-fold enhancement at 450 nm within 434 ms, which ranks among the fastest response times reported. The probe demonstrates a low detection limit of 5.3 nM and a large Stokes shift of 113 nm. CUM-DMTC displays exceptional selectivity, anti-interference capability, and photostability-the fluorescence intensity increases by only 0.9% after continuous irradiation for 9000 s. The sensing mechanism was systematically validated through density functional theory calculations, high-resolution mass spectrometry (HRMS), (1)H NMR spectroscopy, and Fourier-transform infrared spectroscopy (FT-IR). Portable test strips combined with smartphone-based RGB readout enabled on-site quantitative detection of HClO in real water samples. Furthermore, the probe exhibits low cytotoxicity and remarkable intracellular photostability (supporting continuous scanning for over 30 min), and successfully visualizes HClO in HeLa cells and live zebrafish, highlighting its strong potential for real-time bioimaging applications.","pmid":"42364587","doi":"10.1016/j.talanta.2026.130199","url":"https://pubmed.ncbi.nlm.nih.gov/42364587/"},{"id":37,"title":"Impact of Chemical Aging on Venison Processing Knife Topography and Recoverable Chronic Wasting Disease Prion Seeding Activity.","authors":"Bryant, Damani N; Lurndahl, Nicole A; Ellis-Cramer, Maddy; Gresch, Sarah C; Schwabenlander, Marc D; Larsen, Peter A; Wolf, Tiffany M; Lichtenberg, Stuart S","year":2026,"date":"2026 Jun 17","journal":"Pathogens (Basel, Switzerland)","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Infectious prion adsorption on metal, minerals, wood, and plastic is well documented, raising the specter of food safety hazards for meat packing workers, sport hunters, and consumers. We previously demonstrated that sodium hypochlorite, and to a lesser extent, potassium peroxymonosulfate, and hypochlorous acid can decontaminate prion-contaminated nonporous surfaces. However, the extent to which chemical aging of surfaces affects subsequent recoverable prion seeding activity is unknown. In this study, we investigated the potential for four chemical decontaminants known for their anti-prion activity (sodium hypochlorite [bleach], hypochlorous acid [Briotech], potassium peroxymonosulfate [Virkon-S], and Wex-Cide-128) to alter the surfaces of steel knives and the subsequent prion decontamination efficacy of each. We found that hypochlorous acid, sodium hypochlorite, and potassium peroxymonosulfate corrode the surfaces of steel knives, resulting in significant physical alterations. Knives exposed to hypochlorous acid exhibited the most substantial corrosion (rust), which is consistent with its oxidizing effects. Oxidation of the knife surface was corroborated by complementary energy-dispersive X-ray spectroscopy data trends. Scanning electron microscopy data indicate corrosion is apparent after minimal exposure to oxidizing agents. Finally, we used the real-time quaking-induced conversion assay on swabs collected from chemically aged knife surfaces to evaluate recoverable surface-associated CWD-prion seeding activity detected by RT-QuIC after prion exposure and decontamination. Our results indicate decreased recoverable prion seeding activity from knife surfaces aged with 40% bleach. We also observed some recoverable seeding activity post-decontamination on knives chemically aged with 10% bleach and Wex-Cide-128, but largely similar efficacy to prior studies. This implies that existing chemical prion decontaminants are likely effective after repeated use on steel surfaces.","pmid":"42347257","doi":"10.3390/pathogens15060645","url":"https://pubmed.ncbi.nlm.nih.gov/42347257/"},{"id":39,"title":"Cutaneous safety evaluation of pure hypochlorous acid solution in preterm infants and neonates with complex wounds.","authors":"Amaya, Rene; Heisler, Emily","year":2026,"date":"2026 Apr","journal":"Wounds : a compendium of clinical research and practice","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Preterm infants are at heightened risk of skin injury and infection due to the immaturity of their epidermal barrier and immune defenses. Safe wound cleansing options remain limited in this population. OBJECTIVE: To evaluate cutaneous safety and tolerability associated with use of a pure hypochlorous acid-preserved cleanser (pHA) in preterm and neonatal patients with complex wounds. MATERIALS AND METHODS: This retrospective study evaluated the cutaneous safety of a pHA in 100 preterm and neonatal patients with complex wounds admitted to a tertiary care facility between January 2023 and July 2025. Demographic, clinical, and wound data were extracted from the electronic medical record. pHA was applied at each wound care encounter and was continued until wound closure, discharge, or transfer of care. RESULTS: Patients received a mean of 7.6 pHA applications over a mean treatment duration of 18.7 days. The youngest treated infant was born at 21 weeks' gestation. Across 766 cumulative applications, no cutaneous adverse effects or wound-related complications were observed, including contact dermatitis, erythema, chemical burns, infection, or secondary breakdown. In patients receiving pHA concurrently with other advanced wound therapies, no cutaneous adverse effects attributable to combined use were identified. CONCLUSION: This retrospective series represents the largest reported evaluation to date of cutaneous safety and tolerability associated with pHA use in neonatal patients. Future prospective multicenter studies are warranted to further characterize cutaneous safety of pHA use and to evaluate efficacy outcomes in neonatal wound care.","pmid":"42319836","doi":"10.25270/wnds/25126","url":"https://pubmed.ncbi.nlm.nih.gov/42319836/"},{"id":47,"title":"Ultrafine \"dry vapor\" hypochlorous: proof-of-concept disinfection application.","authors":"Hogan, Reed B 2nd; Mijalis, Eleni; Green, Charlotte; Porter, Terrell; Spankovich, Christopher","year":2026,"date":"2026","journal":"Frontiers in cellular and infection microbiology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"INTRODUCTION: Current disinfection strategies are limited by cost, safety concerns, and logistical inefficiencies, particularly in busy healthcare environments. Hypochlorous acid (HOCl) offers broad-spectrum antimicrobial activity with a well-established safety profile, but its use as an ultrafine aqueous \"dry vapor\" has not been widely studied in healthcare settings. This proof-of-concept study evaluated the feasibility of using ultrafine aqueous HOCl for large-scale disinfection in outpatient medical facilities. METHODS: Four outpatient facilities ranging from 4,500 to 90,000 square feet were treated with ultrafine aqueous (<2 micron) HOCl. Samples were collected from staff, procedure, and public areas. ATP bioluminescence in Relative Light Units (RLU) was measured before treatment and at 30 and 60-minutes post-treatment. Results: Statistically significant reductions in RLU were observed at 30 minutes (p < 0.001) and 60 minutes (p < 0.001) post-treatment compared to baseline. Significant reduction was also noted from 30 minutes to 60 minutes (p < 0.001). All facilities achieved disinfection levels below the guidelines for terminal disinfection of hospital non-surgical areas. CONCLUSION: Ultrafine aqueous HOCl is an efficient and safe disinfection method for large medical facilities, with implications for improving infection control practices and reducing healthcare-associated infections.","pmid":"42291301","doi":"10.3389/fcimb.2026.1679518","url":"https://pubmed.ncbi.nlm.nih.gov/42291301/"},{"id":49,"title":"[Not Available].","authors":"Cortés Luengo, Solange; Villalobos Sandoval, Ana; Farfán Cerda, Valentina; Dachardi Astete, Valentina; Silva Opazo, Carolina","year":2026,"date":"2026 Jun","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"","pmid":"42275429","doi":"10.12968/jowc.2026.0256","url":"https://pubmed.ncbi.nlm.nih.gov/42275429/"},{"id":50,"title":"Bactericidal, fungicidal, and antiviral activity of highly purified hypochlorous acid water.","authors":"Mokudai, Takayuki; Iwasawa, Atsuo; Kikuchi, Kenji; Niwano, Yoshimi","year":2026,"date":"2026","journal":"Journal of microorganism control","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"This study demonstrates that high-purity hypochlorous acid water (HP-HAW) produced via reverse osmosis (RO) membrane filtration exhibits rapid, broad-spectrum antimicrobial and antiviral activity, comparable to that of hypochlorous acid water (HAW) prepared without RO membrane treatment. Common vegetative bacteria, dermatophytes, and Candida albicans were completely inactivated within 10 s, indicating excellent performance for routine disinfection. HP-HAW also showed moderate efficacy against Mycobacterium abscessus but limited activity against M. avium, M. kansasii, and spore-forming bacteria. Filamentous fungi such as Aspergillus niger were more resistant than the other fungal species tested, requiring longer exposure. Strong antiviral activity was observed against adenoviruses, influenza virus, norovirus, and others, although some enteroviruses (e.g., coxsackievirus A6 and B5) were resistant. Overall, HP-HAW demonstrates promising disinfectant properties comparable to those of HAW without RO membrane filtration; however, its limited efficacy against certain pathogens should be considered for practical applications.","pmid":"42270376","doi":"10.4265/jmc.31.2_67","url":"https://pubmed.ncbi.nlm.nih.gov/42270376/"},{"id":51,"title":"HYPOChLorous Acid TEsting Studies in elective groin VASCULAR surgery (HYPOCLATES:VASCULAR): protocol for an ambispective cohort study evaluating a standard change to hypochlorous acid lavage in patients undergoing elective groin vascular surgery.","authors":"Nadvornik, Mika P; Uhl, Jonathan; Hoch Al Hessen, Tobias; Siegel, Niels; Kramer, Axel; Michalski, Christoph W; Böckler, Dittmar; Meisenbacher, Katrin; Harnoss, Julian C","year":2026,"date":"2026 Jun 4","journal":"BMC surgery","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Surgical site infections remain a frequent and clinically relevant complication following elective open vascular groin surgery, particularly in procedures involving implantation of alloplastic material. Despite routine use in many surgical disciplines, the role of standardized intraoperative wound irrigation in vascular groin surgery is insufficiently defined. Hypochlorous acid is a physiologically occurring antimicrobial agent with broad-spectrum activity and favourable tissue compatibility, making it a promising option for intraoperative wound lavage. However, clinical evidence for its preventive use in elective vascular groin procedures is limited. METHODS: Hypoclates:vascular is a single-centre, ambispective cohort study conducted at Heidelberg University Hospital. Adult patients undergoing elective open vascular groin surgery with arterial exposure are included. A departmental standard change introduced intraoperative wound irrigation with at least 250 ml hypochlorous acid-containing Granudacyn(®) prior to wound closure, with additional irrigation of alloplastic material where applicable. Patients treated before this change form a retrospective control cohort without antiseptic lavage, while those treated thereafter constitute the prospective cohort. The primary outcome is the incidence of surgical site infections classified according to Centers for Disease Control and Prevention criteria. Secondary outcomes include postoperative morbidity, wound-related complications, antibiotic use, length of hospital stay, and overall morbidity assessed by the Comprehensive Complication Index. Multivariable logistic regression will be used to explore associations between hypochlorous acid-based irrigation and infectious outcomes. DISCUSSION: This study provides a pragmatic real-world evaluation of standardized hypochlorous acid-based intraoperative wound irrigation in elective open vascular groin surgery. The results will clarify whether this physiologically compatible antiseptic approach is associated with reduced surgical site infections and postoperative morbidity, thereby informing the design of future randomized trials and evidence-based perioperative standards in vascular surgery. TRIAL REGISTRATION: The study was registered on 25 March 2026 in the German Clinical Trials Register (registration identifier: DRKS00039521) prior to data acquisition.","pmid":"42243808","doi":"10.1186/s12893-026-03902-3","url":"https://pubmed.ncbi.nlm.nih.gov/42243808/"},{"id":52,"title":"A novel lysosome-targeting fluorescent probe for intracellular HClO imaging and aqueous environment detection based on smartphone-assisted quantification.","authors":"Zhang, Jiayi; Wang, Qian; Ren, Yashuang; Xiang, Honglu; Cao, Lamei; Li, Yu; Li, Dan; Gao, Feiran; Xiao, Songyang; Tang, Yuping; Luo, Weifang","year":2026,"date":"2026 Sep 15","journal":"Bioorganic chemistry","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"Hypochlorous acid (HClO), a reactive oxygen species (ROS), regulates multiple physiological and pathological processes in humans. However, its excessive accumulation induces diseases such as inflammatory bowel disease, rheumatoid arthritis, cardiovascular diseases, and neurodegenerative diseases. Besides, HClO is employed for public disinfection in infectious disease outbreaks to block pathogen transmission, but its over-discharge causes water pollution, endangering aquatic organisms and triggering severe human respiratory and skin diseases. To clarify HClO's complex roles in environmental and biological systems, developing accurate detection methods is imperative. This study synthesized a novel naphthalene-derived fluorescent probe Z via acylation and substitution reactions, using 4-bromo-1,8-naphthalimide as the fluorophore, morpholine as the lysosome-targeting group, and dimethylthiocarbamoyl chloride as the recognition group. Probe Z exhibits prominent visualization advantages: upon HClO addition, it turns from pale yellow to fluorescent yellow under 365 nm UV light within 1 min, with a 13-fold fluorescence enhancement, high selectivity, high sensitivity, and a low detection limit of 0.52 nM. It can detect HClO in water samples and achieve fluorescent imaging of lysosomal HClO in cells. Notably, combined with the data processing function of smartphones, it enables reliable quantification of HClO, providing a new tool for exploring HClO's biological roles and on-site high-throughput visual detection.","pmid":"42235425","doi":"10.1016/j.bioorg.2026.110043","url":"https://pubmed.ncbi.nlm.nih.gov/42235425/"},{"id":55,"title":"Comparative Efficacy of Hypochlorous Acid and Mafenide Acetate in Reducing Infection Rates in Postoperative Burn Patients: A Retrospective Cohort Study.","authors":"Carrarini, Mia J; Fedor, Christopher J; Zein, Omar; Liu, Hilary Y; Arellano, José Antonio; Elias, Garth; Corcos, Alain C; Ziembicki, Jenny A; Yassin, Mohamed H; Egro, Francesco M","year":2026,"date":"2026 Sep 8","journal":"Journal of burn care & research : official publication of the American Burn Association","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Infection is a leading cause of mortality in patients with third-degree burns, contributing to over 75% of burn-related deaths. Despite the widespread use of hypochlorous acid (HOCl) and mafenide acetate (MA) as wet dressings in burn care, direct comparisons of their effectiveness are limited. Thus, this study evaluates the relative efficacy of HOCl and MA in managing infections and improving survival outcomes in postoperative burn patients. This retrospective study included adults with second and third-degree burns who underwent excision and grafting between January 2012 and February 2024 at an American Burn Association-verified burn center. Infection, mortality, length of stay, number of operations, and complications were compared across initial antiseptic treatment using chi-square and Mann-Whitney tests. The study cohort comprised 274 patients, the majority of whom sustained flame burns (63.1%), with an average total body surface area burned of 11.2 ± 13.7%. Within the cohort, 88.7% received MA and 11.3% HOCl. Thirteen patients (41.9%) who received HOCl developed an infection requiring antibiotics, which on average, took 6.85 ± 5.71 days to develop. This was not statistically different from those in the MA group, of which 90 patients (37.0%) developed an infection (P = .5840) which took 6.50 ± 8.47 days to develop (P = .4436). Mortality was also not significantly different between groups. No significant differences were found between HOCl and MA in infection, mortality, or morbidity outcomes. Both treatments are viable antiseptic options for postoperative burn care, and clinicians can be flexible in choosing either treatment based on patient needs, cost, or availability without compromising care quality.","pmid":"42176191","doi":"10.1093/jbcr/irag080","url":"https://pubmed.ncbi.nlm.nih.gov/42176191/"},{"id":56,"title":"A cellulose-based near-infrared fluorescent probe for rapid hypochlorous acid detection, ferroptosis monitoring, and in vivo imaging.","authors":"Chen, Yanyu; Li, Shen; Liu, Keyin; Chen, Yunling; Kong, Fangong","year":2026,"date":"2026 Aug 1","journal":"Carbohydrate polymers","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HClO) is a widely used chemical reagent that plays a crucial role in physiological redox homeostasis. However, its precise detection in complex biological and environmental matrices remains challenging. In this study, a novel cellulose-based Nile Red fluorescent probe (TC-NR) was synthesized by covalently tethering a Nile Red derivative (NR) onto a modified cellulose backbone. The cellulose-based probe functions as a \"turn-on\" sensor for hypochlorous acid (HClO) at λ(em) = 667 nm. Owing to its superior fluorescence response, high selectivity, and favorable biocompatibility, TC-NR was validated in live-cell assays. It demonstrated sensitive imaging of exogenous and endogenous HClO, confirming its utility in monitoring dynamic changes in HClO levels during ferroptosis. Moreover, TC-NR exhibited robust performance with high sensitivity and precision (96.16-103.16% achieved recoveries) across diverse real-sample matrices such as tap water, Heihu Spring water, bottled drinking water, milk, and black tea. These results demonstrate the promising utility of TC-NR for the quantitative analysis of HClO, offering a powerful tool for applications spanning from environmental monitoring to biomedical research.","pmid":"42173566","doi":"10.1016/j.carbpol.2026.125438","url":"https://pubmed.ncbi.nlm.nih.gov/42173566/"},{"id":60,"title":"Problems with the iodometric titration method used to evaluate the disinfecting activity of sodium hypochlorite.","authors":"Fukui, Koji; Okada, Yuta; Sugiyama, Kenta; Kishimoto, Ayuta; Kohno, Masahiro","year":2026,"date":"2026 Mar-Apr","journal":"Free radical research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Sodium hypochlorite (NaOCl) is widely used as a disinfectant and antiviral agent because of its strong oxidative properties. The principal antimicrobial species in NaOCl solutions are hypochlorite ion (OCl(-)) and hypochlorous acid (HOCl), whose relative proportions vary with pH. The iodometric titration method (KI method) is commonly used to evaluate disinfecting efficacy by measuring available chlorine; however, it cannot distinguish specific oxidizing species. In this study, we investigated the NaOCl-derived oxidizing species quantified by the KI method using absorption spectroscopy, pH measurements, and electron spin resonance (ESR) analysis to determine whether the KI method appropriately reflects disinfecting activity. NaOCl solutions were prepared by dissolving solid NaOCl in ultrapure water, and portions were acidified with sulfuric acid (H(2)SO(4)). Absorption spectra showed peaks corresponding to OCl(-) in NaOCl solutions and HOCl in acidified NaOCl solutions, indicating that most OCl(-) was converted to HOCl after acidification. However, the KI method yielded nearly identical oxidizing capacities for both solutions, contradicting reports that HOCl has much higher bactericidal activity than OCl(-). Because the KI method enforces strongly acidic conditions through H(2)SO(4) addition, OCl(-) is likely converted to HOCl during measurement, meaning the original chemical composition is not preserved. ESR analysis during the KI procedure further suggested the generation of highly reactive hydroxyl radicals (•OH) while HOCl concentrations remained largely unchanged. These findings indicate that OCl(-) and HOCl may not be directly measured by the KI method. Our results suggest that the conventional KI-based evaluation of disinfecting efficacy may need to be reconsidered.","pmid":"42143403","doi":"10.1080/10715762.2026.2673600","url":"https://pubmed.ncbi.nlm.nih.gov/42143403/"},{"id":61,"title":"Influence of Hypochlorous Acid Obtained From an Electrolytic Device on the Mechanical Properties of Root Dentin.","authors":"Souza, Matheus Albino; Farina, Carolina Bianchi; Longhi, Anna Vithoria da Costa; Dallepiane, Felipe Gomes; Pizzi, Camila Yasmin Monteiro; Piccolo, Nathan Mateus; Zart, Ana Beatriz Canabarro; Trindade, Bianca Gonçalves; Rissardo, Leonardo Scarparo; Ziglioli, Natália Ulmi; Arenhardt, Vicenzo Ghisleni; Steier, Liviu; de Figueiredo, José Antônio Poli","year":2026,"date":"2026 Apr","journal":"Clinical and experimental dental research","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"OBJECTIVES: Sodium hypochlorite (NaOCl) exhibits antimicrobial activity. However, it is associated with negative effects in endodontics, such as cytotoxicity and alterations in the mechanical properties of root dentin, leading to the search for new alternatives. Hypochlorous acid (HClO) exhibits antimicrobial activity and low cytotoxicity as irrigation solution. Therefore, the aim of this study was to evaluate the influence of HClO on the mechanical properties of root dentin. MATERIAL AND METHODS: Samples were obtained from 120 mandibular bovine incisors, which were distributed into four experimental groups: microhardness (30 teeth/60 samples), flexural strength (15 teeth/60 samples), cohesive strength (15 teeth/60 samples), and fracture resistance (60 teeth/60 samples). For all tests, the samples were subdivided into six groups (n = 10): G1: distilled water (DW); G2:1% NaOCl; G3:2.5% NaOCl; G4:5.25% NaOCl; G5:250 ppm HClO; and G6:500 ppm HClO. The irrigation protocol was set at 30 min. Then, a Vickers tester was used to evaluate microhardness, and flexural strength, cohesive strength, and fracture resistance were evaluated in a universal testing machine. One-way ANOVA and Tukey tests were used for multiple comparisons in all evaluations (α = 5%). RESULTS: The highest microhardness was observed in DW, 250 ppm HClO and 500 ppm HClO, with no statistical differences between them (p > 0.05). The highest flexural and cohesive strength were observed in DW, 1% NaOCl, HClO 250 ppm, and HClO 500 ppm, with no statistical differences between them (p > 0.05). Regarding the fracture resistance, there were no statistical differences between all groups (p > 0.05). CONCLUSION: It was concluded that HClO preserved the mechanical properties of root dentin.","pmid":"42046840","doi":"10.1002/cre2.70332","url":"https://pubmed.ncbi.nlm.nih.gov/42046840/"},{"id":64,"title":"From Antibiosis to HOCL Antisepsis: Far-Forward Infection Control in Modern Warfare.","authors":"Rasmussen, Eric D; Makarov, Vasyl","year":2026,"date":"2026 Jun 27","journal":"Journal of special operations medicine : a peer reviewed journal for SOF medical professionals","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Modern military medicine continues to rely heavily on anti-biotic-based infection treatment, even as antimicrobial resistance, delayed evacuation, and contested logistics erode its effectiveness. A renewed emphasis on antisepsis-safe, stable, potent, broad-spectrum, and field-ready-now offers a practical alternative for far-forward field care and delayed evacuation. Hypochlorous acid (HOCl), a natural antimicrobial compound made by human neutrophils, has regained attention for its effectiveness and safety, making HOCl antisepsis the possible first step in far-forward infection prevention. Advances in electrochemistry now permit local high-volume production of pure, physiologically compatible and noncytotoxic HOCl with a rigorously-tested efficacy and safety profile and a 2-year shelf life. Laboratory, clinical, and humanitarian field data on its application to wounds consistently show rapid microbial reduction and biofilm disruption, leading to measurably enhanced wound healing. For those providing care in resource-limited settings, the use of HOCl demonstrates how infection prevention can move beyond pathogen-specific therapy toward safe and effective antisepsis. This paper outlines the rationale, evidence, and operational considerations supporting a proposed transition. It also argues that adopting point-of-injury wound intervention with HOCl might provide a highly effective, easy to use, and tissue-safe antiseptic for Individual First Aid Kits (IFAKs) and Special Operations medics. It concludes that lessons from the war in Ukraine should inform new research evaluating changes in TCCC protocols.","pmid":"42024812","doi":"10.55460/J.Spec.Oper.Med.2026.KPUM-MM54","url":"https://pubmed.ncbi.nlm.nih.gov/42024812/"},{"id":66,"title":"Rethinking Skin Preparation: Is Hypochlorous Acid (Clinisept+) a Safe Alternative Skin Preparation in Aesthetic Surgery?","authors":"Arnaout, Ali; Goodarzi, Mohammad R; Nugent, Nora F; Pacifico, Marc D; Urso-Baiarda, Fulvio; Durrant, Charles A T; Heppell, Simon; Ali-Khan, Ahmed S","year":2026,"date":"2026 Jun","journal":"Aesthetic plastic surgery","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Surgical site infections (SSIs) in aesthetic surgery, though rare (~1%), can compromise outcomes. Standard preoperative antiseptics such as chlorhexidine gluconate (CHG) and povidone-iodine are effective but may cause irritation or toxicity. Clinisept+ is a stabilised hypochlorous acid (HOCl) solution with broad antimicrobial activity and excellent tissue compatibility, yet evidence for its surgical use is limited. METHODS: A prospective, multicentre audit was conducted in four UK private aesthetic surgery clinics (January-August 2024). All patients received Clinisept+ as the sole preoperative skin preparation. Demographics, smoking status, procedure type, antibiotic prophylaxis, SSIs, wound complications, and skin reactions were recorded. SSIs were defined as infections requiring treatment. Associations with smoking and antibiotic use were analysed with Fisher's exact test. RESULTS: A total of 157 patients (median age 45 years; 78% female) underwent diverse aesthetic procedures. The SSI rate was 1.27% (2/157), both minor and resolving with oral antibiotics. All SSIs occurred in smokers without prophylactic antibiotics (p = 0.04 vs non-smokers). Wound-healing complications occurred in 5.1% (8/157), none infected. No skin sensitivity or allergic reactions were reported. CONCLUSIONS: Clinisept+ yielded SSI rates comparable to historical data for CHG and povidone-iodine, with excellent tolerability and no observed skin irritation. HOCl-based preparation may be advantageous in patients with sensitive skin or when operating near mucosal or delicate regions. These findings support its safe use in aesthetic surgery, though randomised controlled trials are warranted to confirm non-inferiority. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.","pmid":"42009924","doi":"10.1007/s00266-026-05806-2","url":"https://pubmed.ncbi.nlm.nih.gov/42009924/"},{"id":67,"title":"A novel fluorescent probe based on 3-hydroxyphthalic anhydride for the differential detection of ClO(-), Al(3+) and Zn(2+) and its application in biological imaging.","authors":"Liu, Bo; Wu, Liangqiang; Xu, Hai; Li, Zhixue; Shen, Renshun; Fan, Zixuan; Bai, Yutong; Xu, Dejun; Yang, Qingbiao; Song, Yan","year":2026,"date":"2026 Oct 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorite (ClO(-)), a commonly used disinfectant in food processing, can pose health risks if there is excessive residue. Aluminum ions (Al(3+)) and zinc ions (Zn(2+)) are closely related to human health, and an imbalance in their concentrations can lead to neurological diseases and metabolic disorders. We used 3-hydroxyphthalic anhydride derivatives as the fluorescent matrix and constructed a new type of multi-functional fluorescent probe BHD by introducing an aminothiazole group. By utilizing the differential interaction mechanisms between the probe and target ions (ClO(-) initiates oxidative quenching, and Al(3+)/Zn(2+) form coordination complexes), the differential detection of three types of ions can be achieved. BHD has good selectivity and can specifically respond in complex environments to achieve differential detection of ClO(-)/Al(3+)/Zn(2+) at different wavelengths. The probe also has good biocompatibility. Biological experiments have proven that the probe BHD has low cytotoxicity and can achieve the visualization imaging of ClO(-)/Al(3+)/Zn(2+) in living cells, providing a new tool for environmental monitoring and biomedical research.","pmid":"42008964","doi":"10.1016/j.saa.2026.127902","url":"https://pubmed.ncbi.nlm.nih.gov/42008964/"},{"id":68,"title":"Determination of the susceptibility of onychomycosis agents isolated in Sakarya to octenidine dihydrochloride and hypochlorous acid.","authors":"Gül, Merve; Çiftci, Ihsan Hakkı; Erman, Gülay; Yağmur, Ahmet Can; Aydemir, Özlem; Kılbaş, İmdat; Köroğlu, Mehmet","year":2026,"date":"2026 Aug","journal":"European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The aim of this study was to investigate the susceptibility of onychomycosis agents to octenidine dihydrochloride (OCT-D) and hypochlorous acid (HOCl) antiseptics using agar dilution, tube dilution, and flow cytometry methods. In this study, onychomycosis agents including dermatophytes (Trichophyton spp., Microsporum spp., Candida spp.) and secondary agents such as Aspergillus niger and Fusarium solani were cultured on Sabouraud dextrose agar (SDA). Species identification was confirmed using MALDI-TOF MS. The minimum inhibitory concentration (MIC) values of OCT-D, HOCl, and terbinafine for dermatophytes grown on culture plates were determined using the agar dilution method and the broth microdilution (tube dilution) method in accordance with the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Following MIC determination, the minimum fungicidal concentration (MFC) was assessed. Based on the MFC results, flow cytometry analysis was performed using SYTO 9 and propidium iodide (PI) dyes to investigate the fungicidal effects of OCT-D, HOCl, and terbinafine.As a result of antifungal susceptibility testing of onychomycosis agents, approximate MIC values obtained by the agar dilution method were 250 mg/L for OCT-D, 128 mg/L for HOCl, and 0.064 mg/L for terbinafine. Using the tube dilution method, approximate MIC values were 62.5 mg/L, 64 mg/L, and 0.032 mg/L for OCT-D, HOCl, and terbinafine, respectively. Flow cytometry-based viability analyses showed that the results obtained using the tube dilution method were more consistent. Since OCT-D and HOCl demonstrated MIC values far below their commercially available concentrations and exhibited high fungicidal activity, further studies suggest that these agents may be strong alternatives for topical treatment.","pmid":"41995953","doi":"10.1007/s10096-026-05477-6","url":"https://pubmed.ncbi.nlm.nih.gov/41995953/"},{"id":70,"title":"Stoichiometric hydrogen peroxide versus hypochlorite generation via dual-cell continuous flow system enables singlet oxygen-dominated phenol oxidation.","authors":"Wan, Zihao; Hong, Hui; Wu, Zelin; Wang, Jie; Xi, Chenyi; Xie, Shiwei; Zhang, Na","year":2026,"date":"2026 Apr","journal":"Water science and technology : a journal of the International Association on Water Pollution Research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Current electrochemical processes utilizing singlet oxygen ((1)O(2)) for wastewater treatment face limitations due to inefficient hydrogen peroxide (H(2)O(2)) generation and uncontrollable stoichiometric ratios between H(2)O(2) and hypochlorite (ClO(-)). To address these operational bottlenecks, this study developed a dual-cell continuous-flow system that decouples the production of H(2)O(2) and ClO(-) to degrade phenol and other organic contaminants. The system features a natural air diffusion cathode (ADC) for energy-efficient H(2)O(2) generation without aeration and a dimensionally stable anode (DSA) for active chlorine production. By optimizing the applied current ratio (ADC:DSA = 2:1), an optimal 1:1 H(2)O(2)/ClO(-) stoichiometric molar ratio was achieved. This precise control successfully maximized (1)O(2) production (steady-state concentration: 5.77 ± 0.24 × 10(-10) mM), resulting in a 97.9% removal of phenol under optimal conditions. Additionally, the system achieved removal rates of 71.6% for bisphenol A and 81.3% for sulfamethoxazole. Furthermore, the (1)O(2)-dominated oxidation pathway suppressed the formation of chlorinated byproducts by 24-48% compared to a conventional single-cell electrochemical method. Overall, this engineered dual-cell architecture effectively overcomes the intrinsic bottlenecks of conventional electro-oxidation, establishing a robust, (1)O(2)-driven paradigm for the safe and selective pretreatment of refractory wastewaters.","pmid":"41983983","doi":"10.2166/wst.2026.248","url":"https://pubmed.ncbi.nlm.nih.gov/41983983/"},{"id":74,"title":"Red-Emissive Carbon Dots from Sustainable Biomass for Selective Sensing and Imaging of Hypochlorous Acid in Swimming Pool Water and Cells.","authors":"Zhang, Mengying; Guan, Yuwei; Su, Shan; Zhang, Congpeng; Cheng, Yong; Wei, Yun","year":2026,"date":"2026 Apr 21","journal":"Analytical chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HClO) detection is crucial for public health surveillance and the early diagnosis of related diseases. Currently, carbon dot (CD)-based fluorescent probes for HClO detection face issues such as insufficient green synthesis, a short fluorescence wavelength, and a lack of in-depth mechanistic studies. To address the above challenges, in this work, the biomass lotus leaf was used as the carbon source, and red fluorescent lotus leaf CDs (L-CDs) were green-synthesized. The probe exhibited high selectivity and sensitivity for HClO, with a detection limit of 0.44 μM. This method was successfully applied to detecting HClO in real water samples and the fluorescence imaging of endogenous and exogenous HClO in living cells. Through the combination of density functional theory calculations and experiments, the structure of L-CDs was speculated, and the oxidation and chlorination reactions with HClO were revealed from the perspectives of molecular structure and electron orbitals. This study introduced a new method for the sensitive detection of HClO, offering further insight into the mechanism of HClO detection by CDs.","pmid":"41949999","doi":"10.1021/acs.analchem.5c08114","url":"https://pubmed.ncbi.nlm.nih.gov/41949999/"},{"id":76,"title":"AIE-based dual-mode chemosensor for hypochlorite detection in water: Environmental and biological applications in diverse water samples, zebrafish, artemia, and plants.","authors":"Kim, Seoyeon; Lee, Yun-Seo; Lee, Sooseong; Lee, Jae Jun; Yun, Kijeong; Kim, Ki-Tae; Kim, Cheal","year":2026,"date":"2026 Jul 5","journal":"Bioorganic chemistry","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"An aggregation-induced emission (AIE)-based dual-mode probe for the fluorogenic and colorimetric detection of hypochlorite (ClO(-)), THP-2·Cl (1,1'-((((1E,1'E)-[2,2'-bithiopHene]-5,5'-diylbis(methanylylidene))bis(hydrazin-1-yl-2-ylidene))bis(2-oxoethane-2,1-diyl))bis(pyridin-1-ium) chloride), was designed. THP-2·Cl exhibited sensitive and selective response to ClO(-), with the activation of strong blue fluorescence and color variation from yellow to colorless in 100% water. The limits of detection in color and fluorescence variations were obtained as 4.5 × 10(-6) M and 1.6 × 10(-6) M. The recognition mechanism was elucidated to be an AIE activation through the cleavage of the imine bond by using electrospray ionization mass spectrometry (ESI-MS), (1)H nuclear magnetic resonance spectroscopy (NMR) titration, and theoretical calculations. Test strips coated with THP-2·Cl could be applied to probe ClO(-) simply. The quantitative analyses for the identification of ClO(-) in real environmental samples including drinking water, tap water, seawater, river water, and sewage were successfully achieved using THP-2·Cl. Interestingly, THP-2·Cl could visualize ClO(-) through fluorescence in various biological system, such as live zebrafish, artemia, fresh onion tissue and celery.","pmid":"41924845","doi":"10.1016/j.bioorg.2026.109815","url":"https://pubmed.ncbi.nlm.nih.gov/41924845/"},{"id":80,"title":"Disruption of pulmonary surfactant function under oxidative stress: structural and biophysical insights.","authors":"Cejas, Jimena Del P; Cañadas, O; Ledesma, A; Rosa, A S; Collada, A; Blanco-Rivero, A; Pérez-Gil, J; Disalvo, E A; Frías, María de Los A","year":2026,"date":"2026 Aug 15","journal":"Journal of colloid and interface science","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Pulmonary surfactant forms surface-active films at the air-liquid interface which are essential for alveolar stability but are highly susceptible to oxidative damage under inflammatory conditions. The reactive species hypochlorous acid (HClO/ClO(-)), generated by activated neutrophils, is a potent oxidant that may compromise surfactant integrity; however, its molecular and functional impact remains incompletely understood. In this study, the effects of oxidative stress induced by HClO/ClO(-) on the biophysical and structural properties of a fully native porcine surfactant were investigated using Langmuir balance, captive bubble surfactometry, differential scanning calorimetry, FTIR-ATR spectroscopy, and epifluorescence microscopy. Oxidation induced concentration- and time-dependent inhibition of surfactant adsorption and interfacial film stability. Langmuir balance experiments revealed selective disruption of films containing unsaturated phospholipids or native mixtures, while saturated monolayers remained largely unaffected. FTIR-ATR analysis showed perturbations in lipid headgroup regions and protein secondary structure rearrangements towards β-sheet-rich aggregates, consistent with oxidative unfolding and aggregation. These molecular changes compromise protein-lipid interactions, delaying adsorption and respreading at the air-liquid interface. Epifluorescence microscopy further revealed disruption of lateral lipid organization and altered formation of three-dimensional surfactant reservoirs enriched in disordered components. Functional assays confirmed impaired reduction of surface tension during quasi-static cycling, partially alleviated under dynamic cycling, suggesting exclusion or depuration of oxidized components from the interface. Together, these findings demonstrate that neutrophil-derived oxidants progressively compromise pulmonary surfactant by targeting lipid-protein cooperativity, leading to early interfacial dysfunction followed by structural reorganization. This mechanistic insight advances understanding of oxidative surfactant inactivation and supports the development of antioxidant strategies or oxidant-resistant surfactant formulations as potential therapeutic interventions for inflammatory lung injury.","pmid":"41905308","doi":"10.1016/j.jcis.2026.140353","url":"https://pubmed.ncbi.nlm.nih.gov/41905308/"},{"id":89,"title":"Dual-channel fluorescent probe for in-situ differential detection of HClO and H(2)S in crops and food.","authors":"Liu, Wei; Zhang, Rumeng; Chen, Yutong; Gu, Wuyan; Du, Haijiang; Han, Zhixiang; Gao, Zhiheng; Wang, Kun; Long, Lingliang","year":2026,"date":"2026 May 1","journal":"Food chemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HClO) and Hydrogen sulfide (H(2)S) are vital redox regulators in crops, yet their imbalance can trigger oxidative stress. Simultaneous detection of both is challenging with conventional single-target probes. To address this, we engineered a dual-functional probe, ZZ, based on a coumarin-quinolinium structure. It selectively identifies HClO and H(2)S via distinct fluorescence channels: blue emission for HClO and near-infrared (NIR) for H(2)S. Additionally, it shows a visible colour change from yellow to colorless or red upon exposure to HClO or H(2)S, respectively, enabling both fluorescent and colorimetric readouts within a single sensing platform. The probe was effectively used for real-time imaging in live cells, zebrafish, and plants under stress. When integrated with a portable device, it also facilitated rapid, in-situ quantification of HClO in foods and H(2)S in beverages. This work establishes a versatile, field-deployable tool for investigating HClO-H(2)S crosstalk in agriculture and enhancing food safety surveillance.","pmid":"41791160","doi":"10.1016/j.foodchem.2026.148712","url":"https://pubmed.ncbi.nlm.nih.gov/41791160/"},{"id":92,"title":"Elevated Antibacterial Activity of a Polygalacturonic + Caprylic Acids Wound Ointment Compared with Hypochlorous Acid in a Three-Dimensional Wound Biofilm Model.","authors":"Gerges, Bahgat; Rosenblatt, Joel; Truong, Y-Lan; Jiang, Ying; Raad, Issam","year":2026,"date":"2026 Feb 8","journal":"Pathogens (Basel, Switzerland)","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Bacterial biofilms play a major role in delayed wound-healing and in the development of chronic, non-healing wounds. Natural, plant-based agents, which can eradicate bacterial biofilms, are alternatives to antibiotics and antiseptics in the treatment of bacterially contaminated wounds. Bacterial wound biofilms are three-dimensional and complex microbial communities. Therefore, in this study, we used a three-dimensional fibrin-gel wound biofilm (FGWB) model to compare a commonly used natural agent in wound care, hypochlorous acid (HOCl), to a combination of two natural plant-based agents, polygalacturonic acid (PG) and caprylic acid (CAP) (PG + CAP), for their abilities to eradicate resistant bacterial biofilms of common wound pathogens methicillin resistant Staphylococcus aureus (MRSA), multi-drug resistant (MDR) Pseudomonas aeruginosa, metallo β-Lactamase Escherichia coli, and Streptococcus pyogenes. PG + CAP produced a significantly greater reduction in viable organisms when compared to HOCL (p ≤ 0.05) against all tested bacterial isolates. PG + CAP was highly effective against biofilms of all resistant bacterial isolates and is a promising option that merits further study for treating chronic wounds contaminated with bacterial biofilms.","pmid":"41754440","doi":"10.3390/pathogens15020188","url":"https://pubmed.ncbi.nlm.nih.gov/41754440/"},{"id":95,"title":"Rationally constructed nanoprobe based on the molecular docking strategy for rapid hypochlorous acid detection in foods and biosystems.","authors":"Ouyang, Min; Zhang, Xueyi; Lin, Qinlu; Zhou, Liyi","year":2026,"date":"2026 Apr 15","journal":"Food chemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HClO) is not only often used as an effective preservative in the food industry, but also is an important reactive oxygen species in organisms. Herein, a series of Near-infrared (NIR) small-molecule HClO fluorescent probes based on dicyanoisophorone fluorophore were constructed by reasonable design, and docking with bovine serum albumin was carried out, and the best docking effect was screened to prepare a fluorescent nanoprobe (DBH-1) for HClO detection via the self-assembly of host and guest. This nanoprobe features outstanding water solubility, good biocompatibility, and high sensitivity (35.56 nM) toward HClO. Impressively, DBH-1 has been successfully used for the detection of HClO in food samples, living cells, zebrafish, and mouse models with satisfactory results. Therefore, DBH-1 can not only serve as a robust tool to detect HClO in food samples and biosystems, but also provide technical guidance and theoretical basis for the design of other self-assembled nanoprobes.","pmid":"41713346","doi":"10.1016/j.foodchem.2026.148505","url":"https://pubmed.ncbi.nlm.nih.gov/41713346/"},{"id":98,"title":"A deprotection-oxidation cascade-regulated dual-responsive near-infrared fluorescent probe for individual and sequential detection of H(2)S/HClO with applications in food safety monitoring.","authors":"Yang, Jie; Fu, Chao; Zhou, Yicong; Zhang, Hua; Song, Xiangzhi; Li, Dandan; Liu, Chuanxiang","year":2026,"date":"2026 Apr 1","journal":"Analytica chimica acta","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: Hydrogen sulfide (H(2)S) and hypochlorous acid (HClO), as critical reactive sulfur (RSS) and oxygen (ROS) species, respectively play dual roles in physiological regulation and food safety. While numerous fluorescent probes exist for individual detection of H(2)S or HClO, dual-functional probes remain rare despite their significant potential in food safety, environmental monitoring, and biomedicine. RESULTS: A novel A-π-A (acceptor-π-bridge-acceptor) type near-infrared fluorescent probe, DCIQ-DNBS, was developed for the first time, featuring dual-response mechanisms for individual and sequential detection of H(2)S and HClO via H(2)S-triggered thiolysis of the 2,4-dinitrobenzenesulfonyl (DNBS) and HClO mediated DNBS-deprotection-oxidation of electron-deficient CC bond cascade oxidation. The probe DCIQ-DNBS demonstrates exceptional selectivity and rapid response times, and offers dual-channel fluorescence signaling with non-overlapping emissions: a near-infrared response at 740 nm for H(2)S (LOD, 49 nM) and a short-wavelength yellow emission at 562 nm for HClO (LOD, 40 nM). Practical applications were demonstrated through DCIQ-DNBS loaded portable test strips, which successfully enabled visual monitoring of gaseous H(2)S in food spoilage samples and quantitative tracing of HClO in foods. Furthermore, cellular studies revealed the probe's capability to detect elevated levels of both H(2)S and HClO in HeLa cells. SIGNIFICANCE AND NOVELTY: This novel single-probe system enables the individual and sequential detection of two distinct analytes in a single assay. By generating unique emission signals for each target, it eliminates the need for separate tests or complex separation steps, thereby revolutionizing efficiency in fields like food safety monitoring.","pmid":"41708239","doi":"10.1016/j.aca.2026.345191","url":"https://pubmed.ncbi.nlm.nih.gov/41708239/"},{"id":103,"title":"Hypochlorous acid lavage versus intrawound vancomycin powder for prevention of deep surgical-site infection after major posterior spine surgery: A retrospective case series with a historical control group.","authors":"Özer, Hıdır; Kaşko Arici, Yeliz; Palaoglu, Selçuk; Kutlu, Hakan; Nabi, Vugar","year":2026,"date":"2026 Jan-Apr","journal":"Journal of orthopaedic surgery (Hong Kong)","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"PurposeDespite systemic antibiotics and topical vancomycin powder, deep surgical-site infections (SSIs) remain a devastating complication of major posterior spine surgery, driving morbidity, costs, and antimicrobial resistance. In this study, we aimed to compare deep surgical-site infection (SSI) incidence following major posterior spine surgery between patients receiving intraoperative hypochlorous acid (HOCl) lavage and a historical control group receiving intrawound vancomycin powder.MethodsIn this retrospective comparative study, 161 patients undergoing major posterior spinal surgery received ≥2L of topical HOCl lavage, while 88 historical controls received intra-wound vancomycin powder. The primary endpoint was deep SSI incidence within 12 months. Demographics, operative variables, and microbiological data were analyzed with rigorous statistical methods.ResultsDeep SSI rates were nearly identical: 3.1% (5/161) with HOCl versus 3.4% (3/88) with vancomycin (p = 0.999), with no HOCl-related adverse effects. Pathogen profiles (including MRSA, S. epidermidis, and E. coli) were comparable between groups, underscoring HOCl's broad-spectrum efficacy.ConclusionHOCl lavage showed similar deep SSI rates to intrawound vancomycin powder in this retrospective cohort; prospective multicenter studies are warranted to validate these findings and define optimal protocols.","pmid":"41656744","doi":"10.1177/10225536261425277","url":"https://pubmed.ncbi.nlm.nih.gov/41656744/"},{"id":107,"title":"A near-infrared fluorescent probe with rapid-response hypochlorite for imaging rheumatoid arthritis and wound healing in vivo.","authors":"Shi, Zhengyang; Wu, Hanbin; Chen, Zhengxin; Wang, Yao; Zhang, Long; Huang, Zhongxi; Zhang, Zhipeng; Yin, Haiyun; Xie, Yusheng; Yu, Changmin","year":2026,"date":"2026 Jun 1","journal":"Talanta","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Real-time monitoring of hypochlorite (ClO(-)) fluctuations in inflamed tissues is crucial for evaluating the onset, progression, and prognosis of inflammatory diseases such as rheumatoid arthritis (RA). In this study, we rationally developed a small-molecule fluorescent probe (SX-ClO) based on a malononitrile-isophorone fluorophore skeleton coupled with a diaminomaleonitrile moiety as the ClO(-)-responsive unit. The probe operated through an intramolecular ICT modulation mechanism upon specific reaction with ClO(-), enabling a remarkable fluorescence turn-on response with high selectivity, excellent sensitivity, and minimal background interference. SX-ClO demonstrated a reliable ability to visualize both endogenous and exogenous ClO(-) in live RAW 264.7 macrophages, thereby facilitating dynamic evaluation of intracellular oxidative microenvironments. Beyond in vitro performance, SX-ClO achieved high-contrast fluorescence imaging of ClO(-) accumulation in λ-carrageenan-induced RA mouse joints, effectively distinguishing inflamed joints from healthy ones. Moreover, the probe successfully detected elevated ClO(-) levels in MRSA-infected wound tissues, providing clear visualization of bacterial infection-associated oxidative bursts. Overall, these properties enable real-time visualization and dynamic monitoring of pathological processes at the molecular level, highlighting its potential for clinical translation in early diagnosis and disease progression tracking.","pmid":"41621290","doi":"10.1016/j.talanta.2026.129485","url":"https://pubmed.ncbi.nlm.nih.gov/41621290/"},{"id":108,"title":"An oxidative cleavage-based HCR-CRISPR/Cas12a biosensor for highly sensitive detection of hypochlorous acid.","authors":"Liu, Xin; Wang, Xiangyue; He, Shaoying; Li, Mingxi; Lu, Chunhua; Xing, Chao","year":2026,"date":"2026 Mar 2","journal":"The Analyst","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HClO) is a critical disinfectant in public health and water treatment, yet its excessive presence in environmental matrices poses significant risks to human health (e.g., respiratory irritation, tissue damage) and aquatic ecosystems (e.g., biodiversity loss). Herein, we developed an oxidative cleavage-based hybridization chain reaction (HCR)-CRISPR/Cas12a biosensor for highly sensitive detection of HClO. The sensor utilizes a dual-lock switch mechanism: HClO selectively cleaves a phosphorothioated (PS) DNA hairpin (Lock 1), releasing an initiator strand to trigger the HCR and generate PAM-containing long dsDNA. Simultaneously, the locked crRNA (L-crRNA), which is caged by a PS-modified silent chain (Lock 2), can be released when the PS-modified silent chain is degraded under HClO incubation, allowing the activated crRNA to dynamically regulate Cas12a-crRNA complex formation. Then, HCR-dsDNA activates Cas12a's trans-cleavage activity, enabling fluorescence signal readout via reporter DNA cleavage. The dual-lock strategy minimizes nonspecific activation in CRISPR/Cas12a systems, significantly enhancing sensitivity and specificity. Our work establishes a robust platform for environmental pollutant monitoring, with applications in water safety assessment and food quality control.","pmid":"41615337","doi":"10.1039/d5an01299f","url":"https://pubmed.ncbi.nlm.nih.gov/41615337/"},{"id":110,"title":"Antibiofilm and antimetabolic effects of disinfectants on Pseudomonas aeruginosa strains isolated from cosmetic manufacturing environments.","authors":"Korzekwa, Kamila; Kowalczyk-Chrząstowska, Daria; Szmurło, Aleksandra; Wernecki, Maciej; Ulatowska-Jarża, Agnieszka; Buzalewicz, Igor; Wojnicz, Dorota","year":2026,"date":"2026 Jan 26","journal":"Applied microbiology and biotechnology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Pseudomonas aeruginosa is a major contaminant in cosmetics, posing significant health risks to consumers. These bacteria form biofilms that protect them from disinfectants commonly used in the cosmetic industry. This study aimed to assess the impact of disinfectants, cleaners, and sanitizers on the metabolic activity and biofilm formation of P. aeruginosa isolated from the production line in a cosmetic manufacturer. In vitro experiments were conducted using silicone, Teflon, ethylene propylene diene monomer and acid-resistant steel surfaces, which are commonly used materials in cosmetic production line equipment. Spectrophotometric methods were used to evaluate biofilm formation and metabolic activity, while different imaging techniques (SEM, EFM, OCT) were employed to visualize biofilm structure directly on examined surfaces. The results showed that hypochlorous acid is the most effective disinfectant in inhibiting biofilm formation. Hypochlorous acid significantly reduced the metabolic activity of P. aeruginosa, particularly in biofilms forming on the surface made of stainless steel. Additionally, the study validated the feasibility of implementing a sterilization method using hypochlorous acid directly in industrial conditions for production line sterilization. Results showed a significant reduction in contamination levels in water passing through the installation, from an uncountable level to below 0.1 × 10(1) CFU mL(-1). In conclusion, the effectiveness of disinfectants in preventing biofilm formation and metabolic activity is dependent on their composition and the type of surface on which the biofilms form. Hypochlorous acid proves to be an effective disinfectant for combating bacterial biofilms in the cosmetic industry. KEY POINTS: The tested strains of P. aeruginosa formed a strong biofilm and were drug-resistant Hypochlorous acid exhibited the highest antibacterial efficacy among the tested agents Hypochlorous acid effectively eliminated biofilm-associated microbes in the facility's water system.","pmid":"41586898","doi":"10.1007/s00253-026-13719-y","url":"https://pubmed.ncbi.nlm.nih.gov/41586898/"},{"id":115,"title":"Polyhexanide, Povidone-Iodine, and Hypochlorous Acid Show High In Vitro Antimicrobial Efficacy Against Pathogens Commonly Associated With Equine Infectious Keratitis.","authors":"Stolle, Leonie Maria; Oltmanns, Hilke; Meißner, Jessica; Heun, Frederik; Schieder, Ann-Kathrin; Wolff, Hinrich Tönjes; Ohnesorge, Bernhard; Busse, Claudia","year":2026,"date":"2026 Jan","journal":"Veterinary ophthalmology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVE: To determine the in vitro antimicrobial activity of specific antiseptics against common equine ocular surface pathogens. METHODS: Staphylococcus aureus (S. aureus) (n = 12), Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) (n = 9), Enterobacter hormaechei (E. hormaechei) (n = 6), and Bacillus cereus (B. cereus) (n = 5) were collected from corneal samples of horses with ulcerative keratitis. Reference strains were included. Minimum bactericidal concentrations (MBC) of polyhexanide, povidone-iodine, and hypochlorous acid were tested using the microdilution method. After incubation with the antimicrobial agent, the inocula were subcultured according to the Clinical and Laboratory Standards Institute guidelines. Colony growth was manually counted and photographically documented. RESULTS: The MBC values of polyhexanide were 0.8-3.2 ppm for S. aureus, 0.8-1.6 ppm for S. zooepidemicus, 1.6-3.2 ppm for E. hormaechei, and 1.6-6.4 ppm for B. cereus. For povidone-iodine, values were 8-32 ppm for S. aureus, 4-16 ppm for S. zooepidemicus, 8-16 ppm for E. hormaechei, and 8-16 ppm for B. cereus. For hypochlorous acid, values were 0.4-6.4 ppm for S. aureus, 0.4-3.2 ppm for S. zooepidemicus, 0.8-1.6 ppm for E. hormaechei, and 1.6-6.4 ppm for B. cereus. The MBC values of methicillin-resistant S. aureus isolates were comparable to those of methicillin-susceptible isolates. CONCLUSION: All antiseptics are highly efficient against common equine ocular bacterial surface pathogens, in concentrations that are well below those of commercially available products. In accordance with the One Health approach, these findings highlight their potential in treating infectious ocular surface disease either as an alternative or alongside topical antibiotics. Further in vivo and clinical studies are required to investigate the translatability of their in vitro effectiveness to clinic cases.","pmid":"41552904","doi":"10.1111/vop.70141","url":"https://pubmed.ncbi.nlm.nih.gov/41552904/"},{"id":121,"title":"Practical and versatile hypochlorite sensor using a xanthene scaffold: Integrating theoretical analysis with environmental and biological applications.","authors":"Lee, Jae Jun; Batsaikhan, Otgontsetseg; Kim, Soyeon; Choi, Yoonseo; Kim, Ki-Tae; Kim, Cheal","year":2026,"date":"2026 Feb","journal":"Bioorganic chemistry","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"A xanthene-based fluorescence and colorimetric sensor, HCC (2,3,6,7,11,12-hexahydro-1H,5H,10H-chromeno[2,3-f]pyrido[3,2,1-ij]quinoline-13-carbaldehyde), was designed for the selective detection of ClO(-). HCC exhibited detection limits of 0.36 μM in fluorescence and 3.0 μM in UV-vis analysis and demonstrated high selectivity against various anions and ROS. The ClO(-) sensing mechanism was examined using (1)H NMR, ESI-MS, and DFT calculations, revealing that fluorescence quenching resulted from xanthene ring cleavage and π-conjugation disruption. The practical applicability of HCC was evaluated in water samples, test strip-based detection, and smartphone-assisted quantification. In addition, bioimaging experiments using zebrafish confirmed ClO(-)-induced fluorescence quenching in living organisms, while edible plant-based sensing demonstrated its utility in tracking ClO(-) uptake through root absorption. Furthermore, HCC was successfully applied for ClO(-) residue detection on mushrooms. These results suggest that HCC serves as a highly sensitive and versatile ClO(-) sensor with potential applications in environmental monitoring, biological imaging, and food safety assessment.","pmid":"41478198","doi":"10.1016/j.bioorg.2025.109455","url":"https://pubmed.ncbi.nlm.nih.gov/41478198/"},{"id":122,"title":"Hypochlorous Acid as an Adjunctive Treatment for Periocular Necrotizing Fasciitis.","authors":"Jordan, David R; Kanda, Pushpinder","year":2026,"date":"2026 Jul-Aug 01","journal":"Ophthalmic plastic and reconstructive surgery","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"PURPOSE: To report the outcomes of a small case series of patients with periorbital necrotizing fasciitis (PONF) treated with high-dose intravenous antibiotics and dilute, pure hypochlorous acid (HOCL) irrigated through affected tissues as well as sprayed topically, with no tissue debridement. METHODS: In this single-center, retrospective chart review, 6 patients were identified between May 1, 2022, and May 1, 2024, with PONF who had HOCL used during their treatment. The primary outcome measures included successful eradication of infection, acceptable aesthetic result with minimal or no reconstruction required, and little or no loss of vision. Results of treatment were compared with those PONF patients in the literature treated more traditionally with antibiotics and debridement, and those treated with antibiotics alone. RESULTS: Of the 6 patients identified with PONF, all 6 were treated with dilute, pure HOCL (0.033%). The median age of the patients was 51 (range 32-73). The female-to-male ratio was equal. The median follow-up time since the first presentation was 158 days (range 30-180). Streptococcus pyogenes was the most common causative organism, found in 80% of cases. No patient underwent tissue debridement in the periocular area. All patients recovered with minimal sequelae. No patient reported loss of vision on their final follow-up visit. There were no patients who required enucleation or exenteration and no patients died because of PONF. CONCLUSIONS: The authors describe a simple method of introducing dilute, pure HOCL (0.033%) without hypochlorite or sodium hypochlorite as impurities via irrigation and topical spray into the treatment plan for PONF. There was little if any loss of tissue with this treatment in this series. The outcomes compared favorably to those outcomes in the literature of PONF patients treated more traditionally with antibiotics and debridement, and those patients treated more conservatively with antibiotics alone. HOCL irrigation and spray techniques appear to be beneficial in the management of PONF and decrease the need to debride, allowing faster disease resolution and contributing to favorable outcomes.","pmid":"41474122","doi":"10.1097/IOP.0000000000003170","url":"https://pubmed.ncbi.nlm.nih.gov/41474122/"},{"id":133,"title":"High rate pervaporation and disinfection efficacy of hypochlorous acid in vacuum-driven membrane process.","authors":"Sakurai, Ayaka; Shimada, Chisato; Fukuzaki, Satoshi","year":2025,"date":"2025","journal":"Journal of microorganism control","category":"Materials & industrial applications","evidence":"Journal article / other","relevance":"Medium","abstract":"This study investigated the pervaporation of hypochlorous acid (HOCl) using a vacuum-driven process with a separation module containing 6,000 silicone rubber (SR) hollow fibers. Gaseous hypochlorous acid (HOCl((g))) discharged from the membrane module was accumulated in a 1 m(3) chamber. Weakly acidic (pH 5.0) hypochlorite solutions with free available chlorine (FAC) concentrations of 100-1,000 mg/L were fed through the lumen of the SR hollow fibers. Both the HOCl permeation rate and the steady-state HOCl((g)) concentration increased with the feed FAC concentration. When a 1,000 mg/L hypochlorite solution was used, the HOCl((g)) concentration in the chamber reached 5,500 ppb within 40 min. This accumulated HOCl((g)), when applied to microorganisms on wet agar plates at a concentration of approximately 320 ppb, achieved a >3-log reduction in viable bacterial cells within 10 min and fungal spores within 20 min. These results demonstrate that high-rate pervaporation of HOCl can be achieved using an SR hollow fiber membrane in a vacuum-driven process, and the resulting HOCl((g)) is effective for rapid disinfection.","pmid":"41391859","doi":"10.4265/jmc.30.4_121","url":"https://pubmed.ncbi.nlm.nih.gov/41391859/"},{"id":134,"title":"Pervaporation of hypochlorous acid using a hollow fiber membrane made from silicone rubber and its application for indoor disinfection.","authors":"Sakurai, Ayaka; Shimada, Chisato; Fukuzaki, Satoshi","year":2025,"date":"2025","journal":"Journal of microorganism control","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The high permeability of silicone rubber is beneficial for use in membranes for pervaporation. In this study, pervaporation of hypochlorous acid (HOCl) was studied using a separation module containing a 6,000 silicone rubber (SR) hollow fiber membrane. Pervaporation experiments were conducted in a 1 m(3) chamber. The membrane module was operated without using a vacuum pump, and the permeation of HOCl proceeded according to the solution-diffusion process. When weakly acidic (pH 5.0) hypochlorite solutions with concentrations of 100-1,000 mg/L were fed through the lumen of the SR hollow fiber membrane, the permeation of HOCl proceeded spontaneously under atmospheric pressure. During the operation of the membrane module, the concentration of gaseous hypochlorous acid (HOCl((g))) in the chamber gradually increased and reached a steady state. The steady-state HOCl((g)) concentration increased as the concentration of undissociated hypochlorous acids (HOCl((aq))) in the feed hypochlorite solutions increased. An exponential dependence of the steady-state HOCl((g)) concentration on the steady-state HOCl((aq)) concentration was observed. Operation of the SR hollow fiber membrane fed with weakly acidic hypochlorite solutions (i.e., 500 mg/L) in a 75 m(3) room resulted in a uniform distribution of 7-10 ppb HOCl((g)), thereby exerting a moderate bactericidal effect against Staphylococcus aureus cells.","pmid":"41391858","doi":"10.4265/jmc.30.4_115","url":"https://pubmed.ncbi.nlm.nih.gov/41391858/"},{"id":135,"title":"Evaluation of test methods and the efficacy of hypochlorous acid water atomization against Pseudomonas aeruginosa in hospital rooms.","authors":"Takahashi, Mikio; Simooki, Osamu","year":2026,"date":"2026 Jun","journal":"Infection, disease & health","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: Since the COVID-19 pandemic, the use of hypochlorous acid water has been spreading. However, limited studies have assessed its safety and efficacy when atomised in hospital environments. This study evaluated the disinfection performance of atomised hypochlorous acid water against Pseudomonas aeruginosa, a key pathogen in nosocomial infection control. METHODS: Two test methods for P. aeruginosa, which is susceptible to drying, have been developed. In the first method, 10 μL of bacterial suspension was pipetted onto five spots in a Petri dish, allowed to dry, and solidified (bacterial suspension 'pipetting method'). The second method involved diluting the bacterial suspension 100-fold in saline and pouring 8 mL into a Petri dish (bacterial suspension 'pooling method'). RESULTS: In the pipetting method, no reduction in viable bacteria was observed following atomization of 40 ppm hypochlorous acid water, whereas a significant bactericidal effect (p < 0.001) was detected at 300 ppm. Conversely, in the pooling method, a significant reduction in viable bacteria (p < 0.01) was observed at 40 ppm, with bacterial counts falling below the detection limit at 300 ppm, clearly demonstrating a strong bactericidal effect. The effectiveness of the pooling method may be attributed to enhanced penetration of hypochlorous acid particles, which could promote oxidative action. CONCLUSION: These findings confirm the bactericidal efficacy of hypochlorous acid water atomization in hospital wards against P. aeruginosa. Furthermore, as a performance test, these methods were close to real clinical settings in terms of nutritional conditions and the pooling method could properly evaluate desiccation-sensitive bacteria.","pmid":"41339195","doi":"10.1016/j.idh.2025.10.001","url":"https://pubmed.ncbi.nlm.nih.gov/41339195/"},{"id":137,"title":"Isoform-specific oxidative modifications of tropoelastin by HOCl and MPO alter protein self-assembly.","authors":"Mikkelsen, Karoline Lindgaard; Nybo, Tina; Davies, Michael J; Rogowska-Wrzesinska, Adelina","year":2025,"date":"2025 Dec","journal":"Redox report : communications in free radical research","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: Tropoelastin (TE), the soluble precursor of elastin, is critical for the elasticity of arteries, lungs, and skin. Oxidative damage to TE has been implicated in vascular diseases, but the isoform-specific effects remain poorly understood. Hypochlorous acid (HOCl), generated by the enzyme myeloperoxidase (MPO) targets extracellular matrix proteins during inflammatory processes. However, the differential susceptibility and functional consequences in specific TE isoforms are unknown. METHODS: We investigated the effects of HOCl and MPO-derived oxidants on two human TE isoforms, TE2 and TE6. Oxidative modifications were analyzed using high-resolution LC-MS/MS, with site-specific identification of chlorinated tyrosines and oxidized cysteine residues. Functional consequences were assessed using turbidity-based coacervation assays. RESULTS: TE2 exhibited chlorination at multiple tyrosine residues, particularly 3,5-dichlorotyrosine, while showing minimal cysteine oxidation. In contrast, TE6 was more oxidised at its single disulfide bond, resulting in irreversible sulfonic acid formation. These isoform-specific patterns translated into functional differences: TE2 demonstrated enhanced coacervation , whereas TE6 showed reduced assembly capacity, consistent with structural destabilization. CONCLUSION: HOCl and MPO-derived oxidants induce distinct modifications in tropoelastin isoforms, resulting in divergent effects on protein self-assembly. These findings highlight the importance of isoform context in extracellular matrix remodeling under oxidative stress and may have implications for vascular pathologies.","pmid":"41312739","doi":"10.1080/13510002.2025.2592409","url":"https://pubmed.ncbi.nlm.nih.gov/41312739/"},{"id":138,"title":"Dissecting HOCl Action in Chronic Wound Biofilms: Proteomic Insights From a Host-Relevant Model of Pseudomonas aeruginosa.","authors":"Robins, Lori I; Gafken, Philip; Lin, Chenwei; Jones, Lisa; Hooper, Sarah E","year":2025,"date":"2025 Dec","journal":"MicrobiologyOpen","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Pseudomonas aeruginosa is found in 48%-52% of chronic wound biofilms, where its resistance to antimicrobials and host immunity presents a major clinical challenge. Although hypochlorous acid (HOCl) is known to be an effective antimicrobial, its mechanism of action remains unclear because standard experimental conditions often produce a mixture of HOCl and hypochlorite (OCl⁻), making it difficult to isolate the effects of HOCl. Here, we use proteomic profiling to investigate the effects of a pure, stable HOCl gel on P. aeruginosa biofilms in a physiologically relevant chronic wound model. We applied HOCl gel (5.7 mM, pH 6) to mature P. aeruginosa biofilms established in a wound-mimicking flow model. Proteins were analyzed using tandem mass tag (TMT)-based quantitative proteomics, identifying 1,878 proteins. HOCl treatment significantly reduced biofilm viability and altered the abundance of 330 proteins. We observed substantial depletion of proteins involved in biosynthesis, virulence, antibiotic resistance, and biofilm formation, alongside enrichment of stress response proteins. These findings indicate a shift toward survival phenotypes and weakened pathogenicity. Our data reveal that HOCl disrupts multiple pathways essential for P. aeruginosa survival and virulence. Crucially, our experimental design eliminates confounding factors that can lead to unintentional testing of mixed HOCl and OCl⁻ species, allowing us to assess the specific effects of HOCl. These findings call for a re-evaluation of HOCl research methodologies and reiterate the importance of realistic infection models in antimicrobial testing.","pmid":"41307276","doi":"10.1002/mbo3.70181","url":"https://pubmed.ncbi.nlm.nih.gov/41307276/"},{"id":139,"title":"Dog- to- dog bite wound management - Comparison of the antiseptic efficacy of polyhexanide and hypochlorous acid with regard to reducing the use of antibiotics: A randomized clinical trial.","authors":"Peters, M; Eberle, D; Reese, S; Wolf, G; Meyer-Lindenberg, A","year":2026,"date":"2026 Feb","journal":"Veterinary journal (London, England : 1997)","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"Therapy of dog bite wounds often includes empirical usage of antibiotics. This prospective clinical study aimed to compare the efficacy of polyhexanide and hypochlorous acid in reducing bacterial wound bio-burden and preventing the necessity for prophylactic antibiotics and to monitor the prevalence of multidrug- resistant bacteria. Thirty-four dogs with 51 bite wounds were randomly assigned to one of the treatment groups. Wounds were surgically debrided and treated with polyhexanide or hypochlorous acid. Swabs for culturing were taken three times: before and directly after debridement and directly after lavage. Veterinary patients were further divided into post-surgery care with and without prophylactic antibiotics. Wound healing until suture removal was monitored. Data were analyzed using a generalized linear model for ordinal data. Positive bacterial culture results after the first swab were obtained in 82.4 % wounds. Staphylococcus pseudintermedius was overrepresented in wounds, which later on developed complications. Neisseria species and streptococci species were overrepresented in cases of delayed wound closure. In 41.2 % of wounds multi-drug resistant bacteria could be detected. No negative effect of occurrence of multi-drug resistant bacteria on wound healing was observed. None of the compared antiseptics showed a significantly better wound decontamination. No superior antiseptic was found for wound lavage. Hypochlorous acid-based antiseptics provide the practical advantage of a shorter contact time. Prophylactic antibiotics should always be considered in severe dog bite wounds and might not be needed in low grade bite wounds.","pmid":"41276211","doi":"10.1016/j.tvjl.2025.106505","url":"https://pubmed.ncbi.nlm.nih.gov/41276211/"},{"id":140,"title":"Mapping of HOCl-oxidized RNA identifies abasic sites as major damage and oxidation product of oxo(8)G.","authors":"Weber, Marlies; Raorane, Kasturi; Grampp, Clara Johanna; Bourguignon, Valérie; Kilz, Lea-Marie; Glänzer, David; Marchand, Virginie; Kreutz, Christoph; Motorin, Yuri; Helm, Mark","year":2025,"date":"2025 Nov 21","journal":"Nature communications","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"RNA oxidation is an important yet understudied process, partly because methods to localize oxidized residues in RNA are lacking. We introduce OAbSeq, a deep-sequencing approach that maps oxidized sites with high sensitivity by exploiting aniline-induced strand scission at noncanonical nucleosides to generate unique ligation-competent fragments utilized for library preparation. Applied to yeast RNA, OAbSeq detects widespread signals predominating at purines, especially at guanosines. Exogenous oxidation increased signal intensity but preserved the guanosine-dominated pattern. Parallel quantification of 8-oxoguanosine (oxo(8)G) and abasic sites revealed that abasic sites are more abundant than oxo(8)G following oxidative treatment in vitro and under physiological conditions. These data support a model in which guanosine oxidation proceeds via transient oxo(8)G yielding abasic sites that can be mapped at nucleotide resolution by OAbSeq. Our findings also suggest abasic sites may be a more informative marker of RNA oxidative damage than oxo(8)G, facilitating studies of RNA oxidation dynamics in cells.","pmid":"41271707","doi":"10.1038/s41467-025-65108-0","url":"https://pubmed.ncbi.nlm.nih.gov/41271707/"},{"id":141,"title":"Furan-modulated ClO(-) probe with typical turn-on fluorescence response, high signal-to-noise ratio and reactivity for applications in food samples, test strips, live cells and zebrafish.","authors":"Xu, Chenggong; Sun, Hao; Xin, Zhongxiang; Rui, Wenjuan; Li, Shuo; Zhou, Yifan; Dan, Wenjia; Dai, Jiangkun","year":2026,"date":"2026 Mar 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"As a reactive oxygen species (ROS) and antibacterial agent, hypochlorite (ClO(-)) is crucial in both food processing and life activities, and ClO(-) fluorescent probes have been widely proposed in recent years. However, research on further improving their sensing performance is still not comprehensive enough. In this work, by introducing benzene and furan groups with different electronegativity, three aggregation-induced emission (AIE) based ClO(-) fluorescent probes with CN bond as the reaction site were rationally prepared. After comparative analysis, it was found the furan group with stronger electron-donating ability can completely eliminate the fluorescence of Probe C, and after the addition of ClO(-), it showed a typical turn-on fluorescence response with a signal-to-noise ratio (S/N) of up to 58.26-fold. Meanwhile, combined with its low background fluorescence, Probe C exhibited better detection sensitivity, and the detection limit (LOD) was as low as 0.16 μM. Moreover, with the assistance of electron-withdrawing diaminomaleonitrile (DAMN), Probe C also demonstrated higher reactivity toward ClO(-) due to the increased electron cloud density around the reaction site, and the reaction equilibrium can be achieved within 4 min. Eventually, Probe C with high specificity and photostability was successfully applied to the accurate determination of ClO(-) in food samples, and demonstrated satisfactory performance in naked-eye recognition using test strips, as well as live cell and zebrafish imaging.","pmid":"41265347","doi":"10.1016/j.saa.2025.127215","url":"https://pubmed.ncbi.nlm.nih.gov/41265347/"},{"id":142,"title":"Cell phenotyping reveals chemical water disinfection treatment-induced molecular and morphological perturbations.","authors":"Zhang, Xin; Harir, Mourad; Schick, Joel A; Lucio, Marianna; Gomes, Inês B; Simões, Manuel; Schmitt-Kopplin, Philippe","year":2025,"date":"2025 Dec 5","journal":"Journal of hazardous materials","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Evaluating how different disinfectants influence the formation and toxicity of disinfection by-products (DBPs) is key to improving water treatment. Previous studies suggest that OXONE (potassium peroxymonosulfate) at ten times the minimum bactericidal concentration (MBC) provides more effective biofilm control compared to conventional chlorination and may serve as a promising alternative disinfectant. In this study, we investigated the changes in molecular composition, formation of DBPs, and human cell morphological responses in synthetic tap water (STW) treated with OXONE and calcium hypochlorite (Ca(OCl)₂) at MBC and 10 ×MBC. Ultrahigh-resolution mass spectrometry revealed that OXONE at 10 ×MBC enriched highly oxygenated CHOS species, increased hydrogen and sulfur content, and produced molecules with lower molecular weight and greater saturation. Ca(OCl)₂ increased CHOCl abundance, with chlorine content rising from 0.04 % at MBC to 0.11 % at 10 ×MBC, while maintaining molecular structures with similar degrees of unsaturation. DBPs analysis showed a 7.2-fold increase in CHOCl₂-DBPs under Ca(OCl)₂ at 10 ×MBC, predominantly in saturated/low-unsaturation structures, while OXONE increased sulfur-containing DBPs by 1.59-fold, mainly with lower aromaticity. Cell painting assay (CPA) in human U2OS cells revealed pronounced morphological changes and viability loss with OXONE at 10 ×MBC (Wilcoxon p < 0.05 vs Ca(OCl)₂), linked to microtubule disruption confirmed by β-tubulin staining. Integration of chemical and morphological data linked toxicity to sulfur-rich features, with CHOS compounds predominating and CHO contributing via OXONE-driven transformations, together driving the observed morphological disruptions. Overall, these findings reveal distinct chemical and cytotoxic effects of each disinfectant, highlighting the need to optimize treatment efficacy with health safety.","pmid":"41265268","doi":"10.1016/j.jhazmat.2025.140504","url":"https://pubmed.ncbi.nlm.nih.gov/41265268/"},{"id":145,"title":"Real-time and continuous monitoring of hypochlorous acid using a wearable sensor based on boronic acid nanofibers and gold nanoparticles.","authors":"Thiruppathi, Murugan; Velusamy, Nithya; Lin, Pei-Ying; Ho, Ja-An Annie","year":2026,"date":"2026 Feb 15","journal":"Biosensors & bioelectronics","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HOCl) is a widely used disinfectant, but excessive exposure can harm humans and plants. Given its widespread use and the likelihood of exposure on surfaces from agricultural and domestic products, there is a critical need for high-throughput, sensitive, and reliable protocols to monitor HOCl levels on plant surfaces and human skin. Conventional electrochemical sensors and the standard N, N-diethyl-p-phenylenediamine (DPD) spectrophotometric method are unsuitable for real-time or on-site detection. We developed a wearable electrochemical sensor integrated with smartphone technology for sensitive HOCl monitoring to address this. The sensor employs a screen-printed carbon electrode (SPCE) modified with polyaminophenylboronic acid (PAPBA) nanofibers and gold nanoparticles (AuNPs), which enhance conductivity and specificity. The modified electrode was thoroughly characterized by surface, functional, and electrochemical analyses, confirming successful fabrication and stability. The device exhibited a wide linear range (10 μM-10 mM) and a low detection limit (0.19 μM). Its practical utility was demonstrated by analyzing HOCl levels in pool water, floor cleaner, and sanitizer, as well as directly on plant leaves and pig skin, highlighting adaptability for smart farming and bioscience research. Reliability was ensured by cross-confirmation with the DPD method, validating accuracy and consistency across diverse environmental contexts.","pmid":"41252932","doi":"10.1016/j.bios.2025.118210","url":"https://pubmed.ncbi.nlm.nih.gov/41252932/"},{"id":147,"title":"A circular crRNA-triggered CRISPR/Cas12a fluorescent platform for detection of myeloperoxidase activity.","authors":"Gao, Yuan; Dong, Peng; Lin, Huan; Tian, Jing","year":2026,"date":"2026 Mar 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase (MPO) is a key enzymatic biomarker for the diagnosis and therapeutic monitoring of acute leukemia. Here, we developed a CRISPR/Cas12a-based fluorescent sensing platform using a circular phosphorothioate-modified crRNA (crRNA-PS) for selective MPO activity detection. In this system, MPO catalyzes hypochlorous acid (HClO) generation, which oxidizes and linearizes the circular crRNA-PS, activating Cas12a-mediated trans-cleavage of a fluorescent reporter. The assay exhibited high sensitivity with detection limits of 0.79 ng/mL for MPO and 0.21 μM for HClO, along with excellent selectivity against reactive oxygen/nitrogen species and biomolecular interferents. Reliable performance was achieved in 1 % fetal bovine serum with recoveries of 92.87-112.54 %. The sensor also maintained stable responses over 8 weeks, indicating strong structural integrity of the circular crRNA-PS. Furthermore, the system was applied for inhibitor screening, yielding IC₅₀ values of 127.2 μM for SHA and 0.81 μM for 4-ABAH. This strategy provides a rapid, sensitive, and robust platform for MPO detection with promising clinical potential.","pmid":"41240694","doi":"10.1016/j.saa.2025.127149","url":"https://pubmed.ncbi.nlm.nih.gov/41240694/"},{"id":150,"title":"The smartphone-assisted fluorescent and colorimetric dual-mode sensor based on novel graphitic carbon nitride quantum dots for environmental sensing and bioimaging of hypochlorite.","authors":"Sun, Xincheng; Ji, Yuxin; Meng, Yachu; Zhang, Xiaoran; Zhu, Jingling; Li, Jun; Shuang, Shaomin; Dong, Chuan","year":2026,"date":"2026 Feb 1","journal":"Biosensors & bioelectronics","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"The novel graphitic carbon nitride quantum dots (g-C(3)N(4) QDs) as dual-mode sensor for fluorescent and colorimetric detection of hypochlorite (ClO(-)) was prepared via a low-temperature solid thermal polymerization method. g-C(3)N(4) QDs exhibited yellow fluorescence at 518 nm. Upon reaction with ClO(-), the -NH(2) groups on the QDs surface were oxidized to N=O, leading to static quenching and a decrease in absorbance. Based on this mechanism, g-C(3)N(4) QDs were used as a dual-mode sensor for ClO(-) with a response time of only 10 s. A linear range of 0.1-70 μM and detection limit of 32 nM (fluorescent method) and 37 nM (colorimetric method) were acquired. Interestingly, the smartphone-integrated sensing platform can portably and visually evaluate ClO(-) changes due to sensitive color changes. This functionality was complemented by its successful application in complex real-world samples, including tap water, swimming pool water, and 84 disinfectants, demonstrating robust practical utility. g-C(3)N(4) QDs were applied to visualize ClO(-) in cells, zebra fish and a tumor-bearing mouse model. This work presented a novel approach for synthesizing g-C(3)N(4) QDs and dual-mode rapidly monitoring ClO(-) in environment. Moreover, g-C(3)N(4) QDs was expected as a potential tool for early diagnosis of cancer via monitoring ClO(-).","pmid":"41166933","doi":"10.1016/j.bios.2025.118155","url":"https://pubmed.ncbi.nlm.nih.gov/41166933/"},{"id":152,"title":"Effects of hydrogen-rich hypochlorous acid water on broiler drinking water bacterial level, growth performance, antioxidant capacity, and intestinal environment.","authors":"Li, Jian; Liu, Chang; Peng, Chonglian; Wang, Yang; Li, Baoming; Yang, Li; Peng, Han; Zheng, Weichao","year":2025,"date":"2025 Dec","journal":"Poultry science","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Pathogenic microbial contamination in broiler drinking water constitutes a critical factor in disease occurrence and transmission within large-scale farming operations. Effective drinking water quality management is essential for optimizing broiler health and production performance. Functional additives, such as hypochlorous acid water (HAW) and hydrogen-rich water (HRW), are often added to farm drinking systems. HAW inhibits bacterial growth, and HRW enhances antioxidant capacity in broilers. This study aimed to investigate the combined effects of these two functional additives and evaluate their impacts on bacteria and biofilm in the drinking water system, broiler production performance, antioxidant capacity, and intestinal environment. A total of 480 broilers were randomly divided into four groups (n = 120 each) and raised for 42 days with distinct aqueous solutions: Group A (tap water), Group B (HAW, 0.3 mg/L), Group C (HRW, 1200 ppb), and Group D (combined HAW and HRW, hydrogen-rich hypochlorous acid water [HRHAW], 0.3 mg/L + 1200 ppb). The results indicated that the sterilization rate of planktonic bacteria in drinking water exceeded 99.90 % after the HRHAW intervention, and the biofilm biomass decreased by 62.85 %. Compared with controls, HRHAW showed no significant impact on the feed-gain ratio but significantly improved breast meat tenderness (39.15 %) and antioxidant capacity (SOD: 6.52 %-27.54 %; GSH-PX: 8.54 %-50.97 %). Intestinal health was enhanced through oxidative stress mitigation and antibacterial effects. In summary, HRHAW successfully integrates the antioxidant benefits of HRW with the antimicrobial efficacy of HAW, significantly reducing the bacterial content in drinking water and enhancing the antioxidant capacity of broilers, thereby positively influencing broiler health.","pmid":"41151446","doi":"10.1016/j.psj.2025.106009","url":"https://pubmed.ncbi.nlm.nih.gov/41151446/"},{"id":154,"title":"Impact of surface roughness on the effectiveness of commercial disinfectants against wet biofilms.","authors":"Stallings, Kayley; Buckley, David; Teska, Peter; Jiang, Xiuping","year":2025,"date":"2025 Nov 4","journal":"Journal of applied microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"AIMS: A standardized approach to mimic real-world surface wear is critical for assessing disinfection performance in practical applications. This study developed a reproducible method to simulate surface damage and evaluate its effect on disinfectant efficacy. METHODS AND RESULTS: First, we developed a novel and reproducible method to standardize surface scratching and simulate worn surface roughness. This was achieved by modifying a Sutherland Rub Tester® with sandpaper, calibrated weight, and controlled abrasion cycles, allowing consistent replication of surface damage for experimental evaluation. Second, we adapted a standardized EPA method to compare disinfection efficacy against Pseudomonas aeruginosa and Staphylococcus aureus biofilms on scratched and nonscratched stainless steel (SS) and high-density polyethylene (HDPE) coupons, treated with three disinfectant products: hypochlorite (CL), hydrogen peroxide (HP), and quaternary ammonium (QA). Surface roughness increased by 0.82 µm (SS) and 12.69 µm (HDPE) after 80-grit sandpaper treatment. Biofilm reductions following three disinfectant treatments ranged from 3.23 to 6.22 logs (P. aeruginosa) and 2.92-5.62 logs (S. aureus) for all coupon types, with surface roughness having no significant impact on disinfection efficacy. A 6-log reduction was achieved only with CL against P. aeruginosa on nonscratched HDPE. CONCLUSION: This study developed a reproducible surface-scratching method and found that biofilm disinfection was affected by bacteria, surface material, and disinfectants.","pmid":"41129390","doi":"10.1093/jambio/lxaf263","url":"https://pubmed.ncbi.nlm.nih.gov/41129390/"},{"id":156,"title":"An Activable Photosensitizer for Sunshine-Driven Photodynamic Therapy Against Multiple-Antibiotic-Resistant Bacteria by Exploiting Macrophage Chemotaxis.","authors":"Wang, Zehui; Wang, Lai; Zhou, Lin; Xiao, Yi; Zhang, Xinfu","year":2026,"date":"2026 Jan","journal":"Advanced materials (Deerfield Beach, Fla.)","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Aiming to improve photodynamic therapy (PDT) safety and specificity at the in vivo level, a new concept is proposed by combining the chemotaxis and circulating ability of macrophages with the controllable therapeutic efficiency of PDT. Moreover, an irradiation strategy is utilized of sunbathing to conduct PDT. Specifically, an inflammation-activable photosensitizer (Lyso710A) based on NIR BODIPY is designed and loaded it into macrophages. These \"armed\" macrophages are then transferred into the infected host to capture bacteria and transport them to the surface of the skin through blood circulation, where sunlight can penetrate. Upon capturing bacteria, the photodynamic effect of Lyso710A is turned on by the macrophage's endogenous hypochlorous acid (HClO). When these macrophages reach the epidermis, the bacteria are eradicated by the photodynamic effect of the activated photosensitizer during exposure to sunlight. Furthermore, this strategy demonstrates promising therapeutic efficacy in two animal models (mouse and rabbit) with systemic bacterial infection, using a low photosensitizer dose of 0.14 mg Kg(-1) in animals. This work demonstrates an intelligent and promising approach to breaking the routine of PDT and, for the first time, executing PDT for deep-tissue bacterial infection simply by bathing in the sunshine.","pmid":"41128169","doi":"10.1002/adma.202508232","url":"https://pubmed.ncbi.nlm.nih.gov/41128169/"},{"id":158,"title":"Synergistic antibacterial effect of hydroxyl radicals generated by the combination of hypochlorous acid and UV irradiation.","authors":"Lee, Hwa Yong; Lee, Han Bit; Kim, Younghee","year":2025,"date":"2025","journal":"PloS one","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"Livestock farms are at risk of exposure to various environmental pollutants, particularly airborne viruses that can cause infectious diseases. Hydroxyl radicals (•OH) are well-known for their strong bactericidal and virucidal properties and are widely applied in disinfection processes. However, their efficacy is significantly diminished in the presence of organic substances. This study investigated the bactericidal effects of hydroxyl radicals generated from hypochlorous acid (HOCl) under UV irradiation and evaluated their resistance to quenching by airborne organic matter. Rose Bengal (RNO) dye was used as a probe to detect •OH radical generation, while yeast extract served as a representative organic contaminant. RNO bleaching efficiency increased in a concentration-dependent manner under UV irradiation, confirming the formation of hydroxyl radicals. However, in the presence of yeast extract, this bleaching effect was drastically reduced, indicating that organic compounds can interfere with radical activity. The bactericidal effects of UV light and HOCl were independently evaluated using Salmonella as a model organism. The presence of organic matter significantly reduced the bactericidal efficacy of both UV and HOCl treatments when applied separately. In contrast, combined exposure to HOCl and UV irradiation demonstrated a 10% increase in bacterial reduction and halved the required exposure time, regardless of HOCl concentration. These findings highlight the synergistic bactericidal potential of HOCl and UV irradiation and support their applicability in airborne bacterial disinfection under realistic environmental conditions.","pmid":"41091726","doi":"10.1371/journal.pone.0334003","url":"https://pubmed.ncbi.nlm.nih.gov/41091726/"},{"id":161,"title":"Trapping DNA Radicals With DMPO Reduces Hypochlorous Acid-Induced 8-oxo-7,8-dihydro-2'-deoxyguanosine and Mutagenesis in Lung Epithelial Cells.","authors":"Lopez, C M; Ramirez, D C; Gomez Mejiba, S E","year":2025,"date":"2025","journal":"Oxidative medicine and cellular longevity","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Pulmonary neutrophilic inflammation (PNI) is the recruitment and activation of neutrophils in the microvasculature with the release of myeloperoxidase (MPO) in the airways. Bystander epithelial cells can take up MPO, where it can generate HOCl. HOCl can react with DNA, generating DNA radicals, which then decay to produce several mutagenic end-oxidation products, such as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo). Herein, we aimed to test whether HOCl-induced DNA radicals precede DNA oxidation and mutagenesis in A549 human lung epithelial cells as an in vitro model that resembles PNI. Interestingly, by trapping HOCl-induced DNA radicals, the nitrone spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) blocks the formation of 8-oxo-dGuo and possibly other end-oxidation products, forming DNA-DMPO nitrone adducts. By preventing DNA oxidation, DMPO reduces the mutation of the hypoxanthine phosphoribosyl transferase (hrpt) gene, one of the genes most sensitive to oxidative damage. The transcription factor p53 is known as the master regulator of the cell response to genomic damage. By trapping DNA radicals, DMPO also blocks the translocation of p53 to the cell nucleus, suggesting that by trapping DNA radicals with DMPO, end-oxidation products are prevented, and the cell response to genomic damage is blunted. Trapping DNA radicals to reduce the accumulation of HOCl-induced mutagenic end-oxidation products will provide new therapeutic avenues to reduce genotoxic damage during PNI.","pmid":"41049128","doi":"10.1155/omcl/8868348","url":"https://pubmed.ncbi.nlm.nih.gov/41049128/"},{"id":162,"title":"Rapid Activation of Amino Acids with Cyanide and Hypochlorite.","authors":"Marshall, Luke K; Yi, Ruiqin; Brown, Joshua J; Fahrenbach, Albert C","year":2025,"date":"2025 Oct 15","journal":"Journal of the American Chemical Society","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Cyanogen chloride (NCCl) produced from the reaction of (-)CN with HOCl has previously been shown to afford activation of ribonucleotides. We now report that NCCl reacts with primary aliphatic amino acids to rapidly produce N-carbamoyl dipeptides in excellent yields (89-98%). Studies with l-alanine suggest that racemization of the amino acids does not occur significantly during the reaction. Quantum chemical (DFT) calculations predict that the mechanism proceeds via activated 2-amino-5(4H)-oxazolone intermediates, which undergo amino acid nucleophilic attack. NCCl can also be generated in situ from glycine and HOCl, enabling the \"sacrificial activation\" of glycine to form N-carbamoyl diglycine. At 70 °C, selective peptide bond hydrolysis yields N-carbamoyl glycine, which is a known peptide precursor. The findings herein build upon prior work involving NCCl in prebiotic ribonucleotide synthesis and activation, highlighting its potential as a general chemical activator for the prebiotic condensation of life's molecular building blocks.","pmid":"41036577","doi":"10.1021/jacs.5c12639","url":"https://pubmed.ncbi.nlm.nih.gov/41036577/"},{"id":163,"title":"Magnetic nanoparticle SERS sensor for rapid and selective detection of ClO(-) in drinking water.","authors":"Wang, Liu; Wang, Mingli","year":2025,"date":"2025 Oct 1","journal":"Mikrochimica acta","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"A selective detection strategy is proposed for the determination of residual hypochlorite in drinking water. Flower-like Fe(3)O(4)@SiO(2)@Ag magnetic nanoparticles can aggregate on a silver film-coated magnetic substrate surface under a magnetic field, enabling the separation and enrichment of the analyte from the sample. 4-Mercaptophenol is functionalized on magnetic nanoparticles enabling quantitative detection of ClO(-) through a \"signal off\" mechanism. This substrate exhibits high sensitivity, with an analytical enhancement factor calculated using Rhodamine B (RhB) as an example reaching 1.89 × 10(5), and a detection limit for ClO(-) as low as 0.0125 mg/L. The substrate also demonstrates good uniformity, reproducibility, and selectivity. Detection in actual drinking water samples indicates the potential application of this detection strategy in food safety.","pmid":"41032103","doi":"10.1007/s00604-025-07586-z","url":"https://pubmed.ncbi.nlm.nih.gov/41032103/"},{"id":165,"title":"Virus inactivation effect of hypochlorite solution containing nitrate ions.","authors":"Satake, Erina; Ishiyama, Maho; Sekiguchi, Masaki; Sasaki, Atsushi; Yano, Shigekazu; Endo, Masatoshi","year":2025,"date":"2025 Dec","journal":"Analytical sciences : the international journal of the Japan Society for Analytical Chemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Hypochlorous acid (HClO) is widely used as a disinfectant due to its strong oxidizing power, but its efficacy is highly dependent on pH and decreases under neutral to alkaline conditions. In addition, its high concentration poses safety and environmental concerns. In this study, we investigated the enhancement of virucidal activity at lower HClO concentrations through the formation of monochloramine (NH(2)Cl) by supplementing with ammonium-form nitrogen (NH(4)(+)-N) or nitrate-form nitrogen (NO(3)(-)-N) under different pH conditions. Using bacteriophage φ6 as an enveloped virus model, plaque assays revealed that virus inactivation was most effective at pH 8 when 15-20 ppm of NH(4)(+)-N was added to 30 ppm HClO solution, with over 90% reduction in infectivity. Under acidic conditions (pH 6), the formation of NH(2)Cl was limited due to the rapid consumption of free chlorine and insufficient generation of NH₃, resulting in reduced virucidal efficacy; however, increasing the amount of NH(4)(+)-N led to improved inactivation effects. In contrast, at pH 8, NH(2)Cl formation was enhanced, contributing to improved disinfection efficiency. Similar effects were observed when NO(3)(-)-N was used, likely due to its reduction to NH₄⁺ in the presence of organic matter. These results demonstrate that optimizing pH and nitrogen sources can improve the efficacy of low-concentration HClO solutions by generating NH(2)Cl in situ, offering a safer and more sustainable approach to viral disinfection.","pmid":"41028557","doi":"10.1007/s44211-025-00831-8","url":"https://pubmed.ncbi.nlm.nih.gov/41028557/"},{"id":167,"title":"Rapid inactivation of aerosolised influenza virus using low-concentration gaseous hypochlorous acid.","authors":"Narihata, Koki; Minamiguchi, Masaru; Hata, Miki; Ueda, Mitsuhiko; Yoshida, Shinji; Sakoda, Yoshihiro","year":2025,"date":"2025 Sep 29","journal":"Scientific reports","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Effective infection control measures are crucial for limiting pathogen transmission, including aerosol infections. Several instances of the use of hypochlorous acid solution spray to inactivate airborne viruses have been reported. However, its effectiveness in controlling infections in aerosol transmission scenarios remains unclear. We evaluated the efficacy of gaseous hypochlorous acid [HOCl((g))], which is safe for occupied environments, in infection control. Exposure to 10-20 ppb HOCl((g)) for several seconds significantly reduced the infectivity of aerosolised H1N1 influenza A virus in water-rich droplets by 2.09-2.79 logs. However, no significant reduction occurred in dry aerosols after water evaporation. A stronger inactivation effect was noted at 50% compared to 30% relative humidity, with a 3.06-fold increase in effectiveness. Comparative analysis with a reactive oxygen species gas (O₃), possessing lower liquid-phase solubility than HOCl((g)), suggested that aerosol water content facilitates HOCl-mediated virucidal activity. Viral infectivity decreased by 2.34 logs under 20-ppb conditions, even in the presence of 0.3% mucin. These findings underscore the effectiveness of HOCl((g)) against aerosolised H1N1 influenza A virus and its potential for infection control.","pmid":"41023359","doi":"10.1038/s41598-025-19020-8","url":"https://pubmed.ncbi.nlm.nih.gov/41023359/"},{"id":170,"title":"Hypochlorous Acid (HOCl) as a Promising Respiratory Antiseptic.","authors":"Winter, Michael; Boecker, Dirk; Posch, Wilfried","year":2025,"date":"2025 Sep 7","journal":"Viruses","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"The COVID-19 pandemic has inflicted unprecedented pressure on communities and healthcare systems around the world. An outstandingly broad and intensive investigation of possible therapeutic interventions is currently taking place to prevent similar future threats to the global population. Investigating the related mechanisms of action is often complex and time consuming. Moreover, research on biochemical interactions of new drugs involves a considerable amount of effort, consequently bearing inherent financial and operational risks for pharmaceutical companies. An interesting approach to counteract colonization and infection is the concept of antiseptic treatment in vivo. Antiseptics are cost-effective and globally accessible, due to their ease of production, transportation and handling. A broad spectrum of active agents with different properties is readily available. One of these substances is hypochlorous acid (HOCl), which is also a naturally occurring biocidal agent and as such part of the innate immune system. Its successful history of medical use in wound treatment, combined with low cytotoxicity and documented efficacy against various pathogens, suggests that HOCl might be an effective agent for treating the respiratory mucosa. This could potentially enable therapeutic inhalation for combating bacterial infections and viral pathogens such as human respiratory syncytial, influenza, and SARS-CoV-2 viruses, which will be discussed in the present article.","pmid":"41012647","doi":"10.3390/v17091219","url":"https://pubmed.ncbi.nlm.nih.gov/41012647/"},{"id":171,"title":"The Use of Hypochlorous Acid in the Treatment of Periorbital Necrotizing Fasciitis.","authors":"Siktberg, Jonathan; Mawn, Louise A","year":2026,"date":"2026 Jul-Aug 01","journal":"Ophthalmic plastic and reconstructive surgery","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Periorbital necrotizing fasciitis (PONF) is a severe skin and soft tissue infection that corrupts the body's natural immune response, leading to extensive tissue necrosis that can result in exenteration or death. Reactive oxygen species, such as hypochlorous acid, are among the elements employed by the immune system in fighting bacterial infection. In necrotizing fasciitis this immune response is thwarted, as the responsible pathogens produce enzymes that eliminate these reactive oxygen species. The host immune response can be augmented by the external application of hypochlorous acid to severely infected tissues. This report presents a case series of 18 orbits from 15 patients treated with a novel treatment approach in the orbit-local administration of hypochlorous acid-in addition to traditional treatment with surgical debridement and intravenous antibiotics. Patients in this series were diagnosed with periorbital necrotizing fasciitis and received local hypochlorous acid administration via an orbital catheter and a Penrose drain to allow for flow-through of the bacterial toxins. Hypochlorous acid was well tolerated in all patients. Zero patients underwent exenteration, and zero patients died. Further investigation into hypochlorous acid treatment in periorbital necrotizing fasciitis is warranted.","pmid":"40990206","doi":"10.1097/IOP.0000000000003061","url":"https://pubmed.ncbi.nlm.nih.gov/40990206/"},{"id":173,"title":"Active electroceutical treatment of Pseudomonas aeruginosa infected murine wounds.","authors":"Mack, Colin R; Wilgus, Traci A; Dellos-Nolan, Sheri; DiCesare, Tony; Bentley, Daria; Daniel, Fraser J; Subramaniam, Vish V; Mahajan, Sahil; Stoodley, Paul; Wozniak, Daniel J; Prakash, Shaurya","year":2025,"date":"2025","journal":"PloS one","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"Chronic, infected dermal wounds have a high burden of cost and remain a persistent hurdle within healthcare. Electroceutical dressings that deliver antimicrobial agents directly to the wound site have emerged as an alternative solution to current standards of care. Here, through a systematic evaluation in an infected murine wound model we report on an actively powered electroceutical dressing that generates hypochlorous acid in situ as an antimicrobial agent to clear infection. In a significant new discovery, we also report that the treatment of these infected wounds with the actively powered electroceutical promotes the closure of wounds better than other test conditions. In a 10-day murine study, mice were wounded, and the dermal injury was infected with Pseudomonas aeruginosa. Four treatment plans were administered to these wounds: no treatment, a commercially available electroceutical dressing, and our electroceutical dressing both powered and unpowered. The mice were subsequently sacrificed 8 days post infection. The powered electroceutical dressing demonstrated significantly reduced bacterial burden compared to untreated wounds. The powered electroceutical dressing also showed the highest wound closure with nearly 60% wound area reduction and approximately 36% percent re-epithelization of the wound bed in contrast to the no-treatment case. When compared against the other treatments, the powered electroceutical dressing demonstrated an improved capability in promoting wound area reduction while lowering infection burden.","pmid":"40982459","doi":"10.1371/journal.pone.0331785","url":"https://pubmed.ncbi.nlm.nih.gov/40982459/"},{"id":177,"title":"Activity of HOCl-generating e-bandage with clinically available hydrogels against Staphylococcus aureus and Acinetobacter baumannii biofilms.","authors":"Dagsuyu, Eda; Kies, Paige; Karau, Melissa J; Patel, Robin; Beyenal, Haluk","year":2025,"date":"2025 Oct 7","journal":"Microbiology spectrum","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Biofilms hinder wound infection healing, making wound infections a healthcare challenge for which innovative treatments are needed. A 1.77 cm(2) electrochemical bandage (e-bandage), which generates the biocide hypochlorous acid (HOCl), has shown promising anti-biofilm activity in vitro, ex vivo, and in vivo. The e-bandage is a three-electrode system operationalized by a hydrogel. In addition to providing a conductive electrolyte for the electrodes, the hydrogel provides a protective barrier for the wound. How different hydrogels impact e-bandage functionality is not completely defined. Here, the in vitro activity of seven clinically available hydrogels (xanthan gum, 3M, Duoderm, Prontosan, Purilon, Skintegrity, and Solosite) was evaluated with 1.77 cm(2) HOCl-generating e-bandages using a potentiostat with a multiplexer in a membrane biofilm model against methicillin-resistant Staphylococcus aureus IDRL-6169 and Acinetobacter baumannii ATCC-17978. When applied with polarized HOCl-producing e-bandages, all evaluated hydrogels except Solosite yielded ≥5.5 log(10)CFU/cm(2) reductions in bacterial quantities after 6 h of treatment, with most being below the detection limit at that time point. Prontosan exhibited antibacterial activity independent of e-bandage. Results of this study inform the selection of clinically available hydrogels that may be suitable for use with a 1.77 cm(2) HOCl-producing e-bandage. IMPORTANCE: In this study, it was shown that some clinically available hydrogels, combined with a 1.77 cm(2) HOCl-generating electrochemical bandage, deliver time-dependent antimicrobial activity against methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii biofilms, offering a potential approach to treat wound infections, including those caused by antimicrobial-resistant bacteria.","pmid":"40965148","doi":"10.1128/spectrum.01762-25","url":"https://pubmed.ncbi.nlm.nih.gov/40965148/"},{"id":179,"title":"Disinfection effects of slightly acidic hypochlorous electrolyzed water on high-frequency contact surfaces in intensive care units: A prospective study.","authors":"Gao, Huihui; Li, Haiwei; Xu, Qiaoxia; Li, Shuyan; Jiang, Yi","year":2026,"date":"2026 Jan","journal":"Journal of occupational and environmental hygiene","category":"Water, sanitation & biosecurity","evidence":"Randomized controlled trial","relevance":"High","abstract":"Appropriate disinfection of high-frequency contact surfaces in intensive care units (ICUs) is vital for controlling and preventing healthcare-associated infections. Two hundred high-frequency contact surfaces in the ICU of Zhejiang Provincial People's Hospital-Yuecheng Branch were selected and randomized into the trichloroisocyanuric acid (TCCA) or slightly acidic hypochlorous electrolyzed water (SAEW) group (100 surfaces per group) for examination from April 8, 2024, to May 10, 2024. TCCA solutions containing 500 mg/L of chlorine and SAEW were used as disinfectants for wiping and disinfecting the surfaces. The bacterial colony count and disinfection pass rate of the two groups at 5 min, 4 hr, and 8 hr after disinfection were compared. No significant differences were found between the TCCA and SAEW groups in 5 min, 4 hr, or 8 hr bacterial colony count. At 5 min, 4 hr, and 8 hr after disinfection, the surface disinfection pass rates of the TCCA group were 97.00%, 76.00%, and 66.00%, respectively, and those of the SAEW group were 96.00%, 73.00%, and 60.00%, respectively. The pass rates did not significantly differ (5 min, p = 1.000; 4 hr, p = 0.626; 8 hr, p = 0.380). The use of SAEW showed comparable results in ICU high-frequency contact surface disinfection to the use of TCCA containing 500 mg/L of chlorine, indicating it is effective for disinfecting high-frequency surfaces in ICUs.","pmid":"40953487","doi":"10.1080/15459624.2025.2555298","url":"https://pubmed.ncbi.nlm.nih.gov/40953487/"},{"id":182,"title":"Effect of single inhalation of hypochlorous acid on the activity of cysteine cathepsins in rat blood plasma.","authors":"Murashevych, Bohdan; Abraimova, Olha; Netronina, Olha; Girenko, Dmitry; Herhel, Tetiana; Maslak, Hanna","year":2025,"date":"2025 Aug-Sep","journal":"Inhalation toxicology","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"OBJECTIVE: Gaseous hypochlorous acid HOCl(g) is a promising agent for continuous complex disinfection of premises, but the toxic effect of its inhalation has been practically not studied. In this study, the effect of inhalation of 0.75 and 1.79 ppm HOCl(g) on ​​the activity of cysteine ​​cathepsins B, H and L, and alpha-1 antitrypsin in the blood plasma of rats was studied to assess the extent of lysosome damage as an element of oxidative stress. MATERIALS AND METHODS: the inhalation exposure was carried out in the 'whole-body' mode during a single 4-hour treatment of animals of two age groups in inhalation chamber equipped with a specially designed evaporative unit. Biochemical parameters were analyzed 2 h and 24 h after the procedure. RESULTS AND DISCUSSION: it was found that the activity of cathepsin L did not change in any of the animal groups, while the activities of cathepsins B and H significantly increased. Inhalation had the greatest effect on cathepsin H, which increased by 1.6-6.4 times in different groups, and the reaction of young animals was more intense. Alpha-1 antitrypsin levels were also elevated both 2 and 24 h after exposure, but age-dependent differences were not significant. In all cases, an increase in the deviation of biochemical parameters from the norm was noted with an increase in the HOCl(g) concentration. CONCLUSIONS: HOCl(g) inhalation at the concentrations used causes pronounced oxidative stress in animals. More detailed biochemical, histological and immunohistochemical studies are needed to assess the toxic consequences of such exposure.","pmid":"40936202","doi":"10.1080/08958378.2025.2558569","url":"https://pubmed.ncbi.nlm.nih.gov/40936202/"},{"id":183,"title":"Engineering a dual-response fluorescent probe for bioimaging of hypochlorous acid and hydrazine in foods, plants, cells and bacteria.","authors":"Fang, Haoran; Qiao, Zixiao; Sui, Xinlin; Quinto, Maurizio; He, Wenmeng; Zhao, Wei; Wang, Beibei","year":2026,"date":"2026 Feb 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Real-time monitoring of toxic hypochlorous acid (HClO) and hydrazine (N(2)H(4)) in food, plants, cells and bacteria is extremely important for ensuring food safety and environmental protection. Thus, a dual-response fluorescent probe has been fabricated for the detection of HClO (548 nm) and hydrazine (448 nm), with low limit of detection (11.4 nM for HClO and 48 nM for hydrazine), and fast response time (200 s for HClO and 5 s for hydrazine). A smartphone-assisted sensing platform was established for quantitative monitoring HClO and hydrazine. The probe was then employed to recognize HClO and hydrazine in plants, food samples, living cells, roots of Arabidopsis thaliana, Pseudomonas aeruginosa and onion epidermal cells. These findings demonstrated the promising potential of the proposed probe in the detection of HClO and hydrazine in food safety and environmental monitoring.","pmid":"40934562","doi":"10.1016/j.saa.2025.126911","url":"https://pubmed.ncbi.nlm.nih.gov/40934562/"},{"id":184,"title":"Hypochlorous Acid for a Persistent Filler Nodule: A Case Report.","authors":"Urbanski, Nicholas; Bommareddy, Kanthi; Aguilera, Shino Bay","year":2025,"date":"2025 Sep 1","journal":"Journal of drugs in dermatology : JDD","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"While noninflammatory nodules after hyaluronic acid (HA) filler injection are a relatively common phenomenon, delayed-onset nodules (DONs) are relatively uncommon and a significant complication of HA filler treatment. DONs can be inflammatory, granulomatous, or infectious. Infectious nodules are a significant concern for aesthetic providers due to the development of biofilms, and understanding the pathophysiology, diagnosis, and management of DONs is essential for clinicians to minimize risks and optimize patient outcomes. A sixty-year-old female presented to the clinic with a 3 cm hard, rope-like, indurated nodule with finger-like projections and purulent exudate on the left zygomatic cheek. She developed a firm, growing nodule, which was treated with hyaluronidase, intralesional fluorouracil, steroids, and antibiotics over multiple visits at an outside clinic. Steroid treatment resulted in attenuation of growth, but the nodule grew subsequently afterward. At our office, we added hypochlorous acid to the treatment plan over 3 clinic visits, resulting in the lesion decreasing in size significantly with no tenderness, swelling, or drainage. Biofilms are a therapeutic challenge because of their antibiotic resistance, unique biochemical milieu, and ability to evade the immune system. Hypochlorous acid is a safe and effective treatment for infections because of its broad-spectrum antimicrobial coverage and oxidative properties.","pmid":"40911738","doi":"10.36849/jdd.9096","url":"https://pubmed.ncbi.nlm.nih.gov/40911738/"},{"id":185,"title":"A water-soluble phenothiazine-based fluorescent probe for selective detection and bioimaging of hypochlorite.","authors":"Yang, Yang; Shao, Yuxin; Bao, Xiaoying; Xu, Ning; Dong, Wu; Gao, Chao-Ying","year":2026,"date":"2026 Feb 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"A hydrophilic phenothiazine-based fluorescent probe (PTZMN) was developed for the selective and sensitive detection of hypochlorite (ClO(-)) in pure water. Upon ClO(-) stimulation, PTZMN exhibited a distinct colorimetric shift and a \"turn-on\" fluorescence response at 496 nm, with a low detection limit of 5.2 × 10(-7) mol/L and excellent linearity (R(2) = 0.9956) within the 0-60 μL range. ESI-MS, (1)H NMR, and DFT studies confirmed that ClO(-) induces oxidative cleavage of the imine (C=N) bond, disrupting intramolecular charge transfer process (ICT). The probe showed high selectivity and strong anti-interference capability, and was successfully applied to ClO(-) detection in disinfectants and water samples, as well as on test strips for naked-eye colorimetric detection and fluorescence detection (LOD < 10(-5) mol/L). Moreover, PTZMN was successfully applied to high-resolution fluorescence imaging in live HeLa cells and zebrafish embryos, with no observable toxicity. These findings highlight PTZMN's potential as a powerful platform for environmental analysis, portable detection and biological redox imaging.","pmid":"40907065","doi":"10.1016/j.saa.2025.126892","url":"https://pubmed.ncbi.nlm.nih.gov/40907065/"},{"id":186,"title":"Dual-optical response probe to HSO(3)(-) and HClO via ICT and solvatochromic effects for food and cellular applications.","authors":"Zhang, Xiufeng; Xu, Yiping; Shi, Lei; Bai, Ruiyang; Zhu, Chenxin; Yuan, Xinyu; Zhang, Siyun; Sun, Hongxia; Lang, Yunhe","year":2026,"date":"2026 Feb 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Sulfite (HSO(3)(-)) and hypochlorous acid (HClO) serve as essential food additives and key raw materials in bleaching agents. However, excessive consumption of these compounds may disrupt cellular redox homeostasis, leading to a series of adverse physical effects. Therefore, the development of reliable analytical methods to detect HSO(3)(-) and HClO levels in food products is of significant importance. In this study, we developed a hemicyanine dye-based fluorescent probe (TBA) for the sensitive and selective detection of HSO(3)(-) and HClO. The probe incorporates distinct recognition sites (a CC bond for HSO(3)(-) and an -NH(2) group for HClO) operating in different solvent systems to enable dual-analyte discrimination. TBA exhibited excellent sensitivity, with detection limits (LOD) of 1.1 μM for HSO(3)(-) (60 min response) in water and 10.7 μM for HClO (40 s response) in ethanol. Furthermore, the probe was successfully adapted into a portable test strip format, demonstrating reliable quantification in real samples (recovery: 88.97-104.88 %). In addition, TBA displayed mitochondria-targeted capability, allowing its application in live cells HSO(3)(-) imaging.","pmid":"40889450","doi":"10.1016/j.saa.2025.126857","url":"https://pubmed.ncbi.nlm.nih.gov/40889450/"},{"id":191,"title":"Periprocedural Use of Hypochlorous Acid Mist for Improving Healing and Cosmesis of the Face After Laser.","authors":"Blyumin-Karasik, Marianna; Colon, Jessica; Gaer, Sophie; Vigil, Isabella; Nguyen, Sylvie; Rosen, Jordan","year":2025,"date":"2025 Aug","journal":"Journal of cosmetic dermatology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Laser resurfacing treatments have revolutionized dermatological procedures by improving skin texture, tone, and quality. Effective periprocedural care remains essential to reduce side effects, support healing, and optimize aesthetic outcomes. Hypochlorous acid (HOCl), a naturally occurring oxidant with anti-inflammatory and antimicrobial properties, has demonstrated efficacy in promoting wound healing and minimizing scarring. AIM: To evaluate the use of stabilized HOCl mist in the periprocedural care of patients undergoing laser resurfacing. METHODS: Ten patients underwent treatment with UltraClear, CO2RE, and/or GentleMax Pro laser devices. Stabilized HOCl mist was applied before and after the procedure, with continued application twice daily for 1 week posttreatment. Follow-up assessments at 1-3 weeks and 1-3 months post-procedure included clinical photography, tolerability evaluation, and aesthetic outcome assessment. Outcomes measured included Clinician Erythema Assessment (CEA), 4-point Edema Scale, Investigator Global Assessment of Pigmentation Scale (IPA), and Global Aesthetic Improvement Scale (GAIS). Statistical analysis was performed using the Friedman and Wilcoxon signed-rank tests. RESULTS: HOCl mist was associated with accelerated recovery, including a noticeable reduction in erythema and pigmentation. Statistically significant improvements were observed in CEA (p = 0.007) and IPA (p = 0.012) scores, indicating reduced clinical severity and pigment alteration. Edema and GAIS scores showed no statistically significant change. CONCLUSION: Stabilized HOCl mist is well-tolerated and may significantly aid post-procedural recovery by minimizing side effects and reducing discomfort. Results support the potential role of stabilized HOCl mist as a beneficial adjunct in post-laser skincare, contributing to faster healing, reduced inflammation, and enhanced cosmetic results.","pmid":"40832716","doi":"10.1111/jocd.70412","url":"https://pubmed.ncbi.nlm.nih.gov/40832716/"},{"id":193,"title":"A ratiometric AIE probe with sequential activation for selective dual detection and imaging of fluoride and hypochlorous acid.","authors":"Wei, Mingjie; Long, Ruiqing; Liu, Rong; Zheng, Linxin; Wang, Simiao; Jiang, Yu; Gu, Biao; Niu, Li","year":2025,"date":"2025 Oct","journal":"Analytical and bioanalytical chemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The development of efficient dual-detection systems for fluoride ions (F(-)) and hypochlorous acid (HClO) in biological environments represents a significant challenge in analytical chemistry, given their distinct chemical properties and crucial yet contrasting roles in physiological processes. Addressing this challenge, we have engineered a sequentially activated fluorescent probe (SA-S-TBM) that leverages aggregation-induced emission (AIE) characteristics to achieve unprecedented simultaneous detection of both analytes under physiological conditions. The design overcomes traditional limitations through a unique cascade activation mechanism: initial F(-)-induced desilylation generates a red-emitting SA-S intermediate, which subsequently undergoes HClO-specific oxidation to produce green-fluorescent SA-SO, creating two well-resolved emission peaks (Δλ = 98 nm) that effectively eliminate spectral interference-a critical advancement in dual-analyte detection technology. Remarkably, SA-S-TBM demonstrates exceptional analytical performance with ultrahigh sensitivity (detection limits of 20.3 nM for F(-) and 1.72 μM for HClO) and outstanding selectivity against competing biological species. Moreover, with low toxicity and excellent cell permeability, SA-S-TBM successfully visualized intracellular F⁻ and HClO through distinct fluorescence signals, highlighting its strong potential for biological detection and as a tool to explore their roles in pathophysiological processes.","pmid":"40826235","doi":"10.1007/s00216-025-06065-x","url":"https://pubmed.ncbi.nlm.nih.gov/40826235/"},{"id":198,"title":"An Acid-Oxidising Solution Containing Hypochlorous Acid Reduces Staphylococcus aureus and Improves Bacterial Diversity in Epidermolysis Bullosa Wounds.","authors":"Zhou, Xiaolong A; Burns, Michael B; Ren, Ziyou; Stagaman, Elise; Green, Stefan J; Wu, Lok Yiu Ashley; Yang, Lynna; Rangel, Stephanie; Rabbaa, Lydia; Paller, Amy S","year":2025,"date":"2025 Aug","journal":"Experimental dermatology","category":"Human clinical & healthcare","evidence":"Clinical trial","relevance":"Medium","abstract":"Epidermolysis bullosa (EB) is a group of rare genetic skin disorders characterised by skin fragility and chronic, painful wounds that are highly susceptible to bacterial infection, particularly by Staphylococcus aureus (SA). This study evaluated the efficacy of an acid-oxidising solution containing hypochlorous acid (HOCl) in reducing SA colonisation, promoting wound healing, and restoring a healthier microbiome in EB wounds. In a 12-week open-label pilot study, 15 EB patients applied the HOCl-based spray (APR-TD011) daily to chronic wounds for 8 weeks, with full-length 16S rRNA sequencing of wound swabs performed before, during, and after treatment. At baseline, 87% of patients were culture-positive for SA, and sequencing revealed that SA had the highest relative abundance (34%), followed by Acinetobacter guillouiae and Pseudomonas poae. SA relative abundance decreased precipitously by Weeks 4 (to 11%) and 8 (primary endpoint; to 10%, p < 0.01), and this effect persisted at 4 weeks post-treatment (Week 12; to 9.7%), including for methicillin-resistant SA. Concurrently, bacterial diversity increased, and wound sizes diminished in correlation with reduced SA levels (r = 0.64). Younger patients exhibited greater SA reduction trends. The treatment was well-tolerated, with minimal adverse effects and high patient satisfaction. This study underscores the role of microbial dysbiosis in EB wounds and highlights HOCl-based solutions as a promising therapy to mitigate pathogenic burden and enhance wound healing.","pmid":"40803690","doi":"10.1111/exd.70147","url":"https://pubmed.ncbi.nlm.nih.gov/40803690/"},{"id":203,"title":"Mitigating Legionella spp. risk in an Australian healthcare facility using on-site electrochemical water disinfection.","authors":"Hem, Sopheak; Drigo, Barbara; Vasileiadis, Sotirios; Brunetti, Gianluca; Smith, Euan; Ferro, Sergio; Lombi, Enzo; Ashbolt, Nicholas J; Donner, Erica","year":2025,"date":"2025 Jul","journal":"Journal of water and health","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Legionella spp. are Gram-negative bacteria present in natural and engineered water systems that can cause legionellosis (Legionnaires' disease and Pontiac fever). When present in biofilms of healthcare facilities, they are a likely source of legionellosis for immunocompromised patients. The objective of this study was to evaluate an electrochemical water disinfection system to produce and dose hypochlorous acid (HOCl) to reduce this risk in a hospital with systemic Legionella spp. contamination. Furthermore, Legionella spp. colony counts were compared to quantitative polymerase chain reaction (qPCR) results. Before and after implementing the disinfection system, tap water and pipe biofilms were analysed for microbial contamination. Post-implementation monitoring continued for over six months, assessing microbial quality using heterotrophic colony counts, Legionella serotyping, and qPCR targeting total bacteria (16S rRNA) and Legionella spp. By the third sampling event (22 days post-commissioning), water quality consistently improved, with no culture-positive Legionella counts observed thereafter. qPCR analysis confirmed these results, proving more sensitive and reliable than traditional methods. The qPCR assays for Legionella spp. and bacterial 16S rRNA were also cost-effective for system optimisation and diagnostics.","pmid":"40742217","doi":"10.2166/wh.2025.395","url":"https://pubmed.ncbi.nlm.nih.gov/40742217/"},{"id":204,"title":"Long-term performance of low-cost free chlorine sensors to monitor on-site water reuse.","authors":"Herold, Gaétan; Rodino, Francesca; Prévoteau, Antonin; Carrara, Sandro; Reynaert, Eva","year":2025,"date":"2025 Jul","journal":"Water science and technology : a journal of the International Association on Water Pollution Research","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Water scarcity increasingly challenges the supply of sufficient quantities of safe water for human consumption. On-site water reuse systems can contribute to mitigating the effects of water scarcity by closing water cycles locally. However, broader adoption of on-site water reuse is constrained by the high cost of water quality monitoring. This work demonstrates the successful design and validation of low-cost chlorine amperometric sensors for long-term monitoring using Prussian blue-coated screen-printed carbon electrodes. The study is relevant for practice, as testing was conducted in a water reuse system treating real greywater and municipal wastewater. The sensors achieved a relatively stable sensitivity of 8.55 ± 1.19 μA/(ppm⋅cm(2)) for hypochlorous acid after a 3-day stabilization period and maintained a sensitivity of 3.72 μA/(ppm⋅cm(2)) after 1 month. The sensors exhibited a linear dynamic range from 0.3 to 5 ppm for hypochlorous acid (R(2) > 0.95). This study highlights the potential of Prussian blue-coated sensors as a practical solution for continuous chlorine monitoring in on-site water reuse applications. The findings encourage further research to improve durability and scalability to optimise the sensors for applications where low-cost sensing solutions are needed without personnel on-site for regular sensor maintenance and calibration.","pmid":"40739827","doi":"10.2166/wst.2025.090","url":"https://pubmed.ncbi.nlm.nih.gov/40739827/"},{"id":213,"title":"An in vitro study of the effects of pathophysiologically relevant levels of oxidative damage on cortical bone tissue quality.","authors":"Iranmanesh, Faezeh; Dapaah, Daniel Y; Tupy, Jindra; Montesano, John; Willett, Thomas L","year":2025,"date":"2025 Nov","journal":"Journal of the mechanical behavior of biomedical materials","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"This study examined the impact of in vitro oxidative damage on cortical bone tissue quality assessed using mechanical testing, biochemical assays, and thermo-analytical methods. The primary hypothesis of this study was that oxidative damage, caused in vivo by oxidative stress-a key factor in aging and various inflammatory diseases-deteriorates bone tissue quality by damaging bone collagen, the main component of the bone's organic phase. To test this hypothesis in vitro, bovine cortical bone specimens were exposed to neutral hypochlorous acid solution (a potent reactive oxygen species) to induce oxidative damage, which was measured in terms of carbonylation. Carbonylation is a stable biomarker of protein oxidation. Mechanical testing revealed degradation of cortical bone mechanical properties due to oxidation. There was a marked degradation of mechanical properties, specifically pre-yield and post-yield properties such as tensile (30-40 %) and compressive (19-23 %) yield strength, as well as tensile (25-45 %) and compressive (11-16 %) ultimate strength. Exposure to neutral hypochlorous acid solutions increased the carbonyl content (normalized to collagen content), confirming protein oxidative damage. In addition, the observed carbonyl levels in the oxidized groups were similar to those measured in human cortical bone specimens. Thermo-analytical tests including differential scanning calorimetry (DSC) and hydrothermal isothermal tension (HIT) tests, providing measures of collagen nativity and connectivity, revealed negative correlations with carbonyl content (r = -0.46, p = 0.0038). The hypothesis that physiological levels of oxidative damage generated in vitro degrade cortical bone mechanical properties by damaging the bone collagen has been confirmed. This suggests that oxidative damage of bone collagen is important towards understanding the degradation of bone quality in aging and various diseases.","pmid":"40663912","doi":"10.1016/j.jmbbm.2025.107108","url":"https://pubmed.ncbi.nlm.nih.gov/40663912/"},{"id":214,"title":"Thiocoumarin Ethenylene-Bridge Dicyanoisophorone Skeleton: A Strategy for Ratiometric Fluorescent Detection of Hypochlorous Acid.","authors":"Yuan, Mengyao; Du, Yongyu; Xu, Kuoxi; Wang, Yuan","year":2025,"date":"2025 Jul 25","journal":"Organic letters","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Herein, an ethylene-bridge bond of diethylaminocoumarin and dicyanoisophorone unit fluorescence probe was developed for the specific detection of HClO. The sensing mechanism involves HClO-induced cleavage of the N,N-dimethylthiocarbamate group, oxidation-triggered ethylene bridge rearrangement, ultimately leading to the formation of a unique thiophene ring structure. The probe was successfully applied for simultaneous detection of HClO in beverage and food samples. Moreover, the probe facilitated high-contrast imaging of both endogenous and exogenous HClO in live cells and in vivo mouse models, offering a powerful tool for elucidating HClO-associated physiological and pathological mechanisms.","pmid":"40643442","doi":"10.1021/acs.orglett.5c01943","url":"https://pubmed.ncbi.nlm.nih.gov/40643442/"},{"id":215,"title":"Effect of intraperitoneal hypochlorous acid (HOCl) on bacterial translocation in an experimental peritonitis model in rats.","authors":"Contarlı, Ahmet; Zihni, Ismail; Şirin, Mümtaz Cem","year":2025,"date":"2025 Jul","journal":"Ulusal travma ve acil cerrahi dergisi = Turkish journal of trauma & emergency surgery : TJTES","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"BACKGROUND: This study compared the effects of saline, routinely used for intra-abdominal irrigation, with hypochlorous acid (HOCl), which we believe could be suitable for clinical practice in the future, on bacterial translocation in a rat model of peritonitis. METHODS: Four groups were formed: Sham, Control, cecal ligation and puncture with saline (CLP+SF), and cecal ligation and puncture with hypochlorous acid (CLP+HA), with 11 rats in each group, for a total of 44 rats. One rat in the Control group died and was excluded from the study. The comparison focused on saline, which is routinely used for intra-abdominal irrigation, and HOCl, which is considered a potential option for future clinical use. RESULTS: A statistically significant difference was observed between the CLP+SF and CLP+HA groups in liver, spleen, and mesenteric lymph node tissue cultures (p<0.001, p=0.004, and p=0.001, respectively). However, no significant difference was found between the CLP+SF and CLP+HA groups in blood cultures (p=0.181). Although bacterial growth in blood cultures was numerically lower in the CLP+HA group, the absence of statistical significance between the CLP+HA group and other groups was attributed to the limited sample size and the short duration of the experimental peritonitis/sepsis model. Additionally, enzyme-linked immunosorbent assay (ELISA) results from blood samples showed that the mean levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), both inflammatory markers, did not differ significantly among the groups. This indicates that HOCl significantly reduced bacterial translocation without suppressing the inflammatory response. CONCLUSION: It is predicted that the widespread use of HOCl in clinical practice could reduce mortality and morbidity in cases of perforation-induced peritonitis of intra-abdominal sepsis, shorten hospital stays, lower the cost of medical treatment, and contribute to the national economy in the healthcare sector.","pmid":"40629731","doi":"10.14744/tjtes.2025.51759","url":"https://pubmed.ncbi.nlm.nih.gov/40629731/"},{"id":217,"title":"Hypochlorous acid as a potential cavity conditioner for caries-affected dentin.","authors":"Sanon, Kittisak; Elseoudy, Nader; Hiraishi, Noriko; Tamura, Yukihiko; Sanchavanakit, Neeracha; ThanNaing, SoeKayThwe; Shimada, Yasushi; Tagami, Junji; Thongthai, Pasiree","year":2025,"date":"2025 Jul 1","journal":"Scientific reports","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"To evaluate the effects of hypochlorous acid (HOCl) conditioning on bond strength to caries-affected dentin (CAD), antibacterial efficacy against Streptococcus mutans (S. mutans), and dental pulp cell compatibility. Extracted human molars with occlusal caries were pretreated with 50 ppm HOCl before adhesive application (Clearfil SE Bond 2), with untreated specimens serving as controls. Microtensile bond strength (µTBS) was evaluated after 24-hour storage and 10,000 thermocycles. Antibacterial efficacy was assessed by colony-forming unit (CFU) enumeration following S. mutans incubation with HOCl solution. Rat dental pulp cells were cultured with HOCl at concentrations of 0, 0.5, 1, 5, 10, and 50 ppm. Cell viability was assessed using Cell Counting Kit-8. Data underwent statistical analysis using one-way ANOVA with Tukey's post hoc test (α = 0.05). HOCl pretreatment significantly enhanced µTBS to CAD (from 25.6 ± 4.3 to 35.8 ± 7.2, p < 0.001) and maintained bond stability after thermocycling (32.1 ± 4.5, p > 0.05). HOCl demonstrated significant antibacterial efficacy against S. mutans with substantial reduction of viable bacteria (p < 0.001). Additionally, HOCl maintained compatibility with dental pulp cells. HOCl shows a promise as a dentin conditioner, offering enhance bond performance to CAD with improved bond durability, while providing antibacterial benefits and maintaining biocompatibility.","pmid":"40596309","doi":"10.1038/s41598-025-06191-7","url":"https://pubmed.ncbi.nlm.nih.gov/40596309/"},{"id":221,"title":"Hypochlorous acid and taurine chloramine co-mediate the innate arm of anti-Vibrio immunity in oyster hemocytes.","authors":"Wu, Siwei; Bai, Jing; Zhang, Xiangyu; Mao, Fan; Luo, Huazeng; Zhou, Ziyuan; Tao, Wensi; Wang, Wei; Yu, Ziniu; Wong, Nai-Kei; Zhang, Yang","year":2025,"date":"2025 Oct","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Balanced and temporally coordinated generation of reactive oxygen species (ROS) and antioxidants is crucial to productive clearance of pathogens in marine molluscan invertebrates, such as the oyster. Despite the presence of an oyster homolog of the myeloperoxidase (MPO) gene in its genome and a hyperabundant pool of intracellular taurine, it remains unclear how precisely ROS-based antibacterial immunity and pro-survival antioxidant production are orchestrated during microbial infections. Herein, we leveraged HKOCl-3, an established probe selective for hypochlorous acid (HOCl), to visualize the dynamics of bactericidal HOCl production in oyster hemocytes challenged with Vibrio parahaemolyticus, a clinically significant Gram-negative pathogen. We hypothesized that taurine (2-aminoethanesulphonic acid), an organosulfur osmolyte that scavenges HOCl efficiently, forms taurine chloramine (TauCl) in vivo to modulate hemocytic immune response, while mitigating host injury. In molecular imaging and flow cytometry, rapid production of HOCl was observed following V. parahaemolyticus challenge. TMB (3,3',5,5'-tetramethylbenzidine) assay confirmed the concomitant formation of TauCl in oyster hemocytes under V. parahaemolyticus stimulation. This TauCl biosynthesis was executed by the cysteine dioxygenase and cysteine sulfinic acid decarboxylase (CDO/CSAD) pathway, as verified by qRT-PCR. The potency of TauCl bactericidal activity was broadly comparable to that of HOCl in bacterial clearance assay. As a pro-survival agent, TauCl mitigated apoptosis in V. parahaemolyticus-challenged hemocytes, while this effect could be nullified by the chloramine scavenger bilirubin. In terms of transcriptomic changes, TauCl stimulated the phagosomes, endocytosis, FoxO signaling pathways, and induced upregulation of various antioxidant enzymes, thereby favoring redox homeostasis in hemocytes. Activation of pro-survival transcription was achieved by TauCl direct binding to Keap1. Overall, our work demonstrated for the first time how phagocyte-derived HOCl and TauCl act as immune effectors within an intimately overlapping window of host defense, with theoretical implications for understanding ROS metabolism and immunomodulation in broader disease contexts.","pmid":"40541803","doi":"10.1016/j.freeradbiomed.2025.06.027","url":"https://pubmed.ncbi.nlm.nih.gov/40541803/"},{"id":222,"title":"Evaluation of commercially available produce antimicrobial washes to improve the quality and microbial safety of fresh produce.","authors":"Mina, Hansel A; Buckley, David A; Burnett, Jack; Deering, Amanda J","year":2025,"date":"2025 Oct 2","journal":"International journal of food microbiology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Despite ongoing efforts to mitigate foodborne pathogen contamination, outbreaks associated with the consumption of fresh produce persist. This research evaluated the efficacy of three sanitizers in reducing various microorganisms on the surfaces of fresh cucumbers, broccoli, and lettuce under retail crisping conditions. Specifically, this study examined the ability of peracetic acid (PAA; 80 mg/L), hypochlorous acid (FAC; 50 mg/L free available chlorine), and accelerated hydrogen peroxide (AHP; 500 mg/L) to reduce pathogens (0.79-2.41 log CFU/g) and natural microbiota, including aerobic bacteria (0.54-2.55 log CFU/g) and yeasts and molds (0.34-1.58 log CFU/g), when applied for 1 min at both 5 and 25 °C. Results showed that all antimicrobial washes significantly reduced pathogens at both temperatures (p < 0.05). Cucumbers treated with the washing solutions exhibited a greater reduction in E. coli O157:H7 (up to 3.72 log CFU/g), S. typhimurium (up to 2.07 log CFU/g), and aerobic bacteria (up to 2.55 log CFU/g) compared to broccoli and lettuce (p < 0.05). This study also investigated the sanitizers' ability to prevent cross-contamination during the retail crisping process of lettuce heads (contact time: 1.5, 3, and 5 min). PAA and FAC significantly reduced cross-contamination with E. coli O157:H7 and S. typhimurium after 3 min of immersion. PAA also significantly reduced L. monocytogenes cross-contamination in batch 2 after 3 min of contact time (p < 0.05). In contrast, immersion of lettuce heads in water alone (WTC) was ineffective at reducing foodborne pathogens and cross-contamination risks. Highlighting the significance of postharvest antimicrobial washes in reducing the contamination and cross-contamination of fresh produce with foodborne pathogens at the retail level.","pmid":"40526997","doi":"10.1016/j.ijfoodmicro.2025.111318","url":"https://pubmed.ncbi.nlm.nih.gov/40526997/"},{"id":223,"title":"Pro-inflammatory properties of M1 phenotypes of human macrophages: prolongation of myeloperoxidase-mediated oxidative stress.","authors":"Yurkanova, Maria D; Kosheleva, Nastasia V; Teplova, Arina A; Timashev, Peter S; Vlasova, Irina I","year":2025,"date":"2025 May","journal":"Free radical research","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Macrophages and neutrophils are the main immune cells of the acute stage of inflammation. Upon their activation, membrane-bound NADPH oxidase produces superoxide anion radical, which is converted to H(2)O(2) by superoxide dismutase (SOD). In this study, we compared the production of hydrogen peroxide by two phenotypes of pro-inflammatory human M1 macrophages and neutrophils activated with phorbol-12-myristate 13-acetate. Macrophages were obtained from blood monocytes (monocyte-derived macrophages (MDM)) differentiated into MDM using GM- or M-CSF growth factors and polarized into the M1 state, receiving GM_M1, M_M1, respectively. The total level of H(2)O(2) production measured in the presence of horseradish peroxidase differed significantly between two types of macrophages. Only GM_M1 macrophages had a level of H(2)O(2) production comparable to neutrophils. GM_M1 appear at the site of inflammation after neutrophils, they continue the work of neutrophils in creating a pro-inflammatory environment: they produce several times more H(2)O(2) and pro-inflammatory cytokines than M_M1, which arrive at inflammatory site later. Upon activation, MDM_M1 formed big blot-like and smaller dense spheroid-like aggregates. Activated neutrophils secrete the enzyme myeloperoxidase (MPO), which synthesizes the very potent oxidant hypochlorous acid (HOCl) only in the presence of H(2)O(2). Neutrophils are short lived cells, MPO can use H(2)O(2) produced by activated cultured MDM to synthesize HOCl at physiologically relevant concentrations to prolong oxidative stress.","pmid":"40525586","doi":"10.1080/10715762.2025.2519528","url":"https://pubmed.ncbi.nlm.nih.gov/40525586/"},{"id":224,"title":"A ratiometric fluorescent probe for sensitive detection of benzoyl peroxide and hypochlorite in food.","authors":"Cui, Shun-Qiang; Liang, Xin-Yi; Cai, Zhi-Qiang; Yuan, Hou-Qun; Zhang, Qiu-Yu; Xia, Yi-Fan; Sandra, A K I M A N A; Guo, Ling-Yi; Wang, Ran; Zhao, Shi-Yu; Li, Yan-Xia; Bao, Guang-Ming","year":2025,"date":"2025 Oct 30","journal":"Food chemistry","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Chronic exposure to oxidants such as benzoyl peroxide (BPO) and hypochlorite (ClO(-)) poses significant health risks, driving the urgent need for sensitive detection methods. We developed a dual-emitting ratiometric fluorescence probe based on europium metal-organic frameworks encapsulated nitrogen-doped carbon dots (N-CDs@Eu-MOFs). This probe enables rapid detection within 1 min for BPO and 3 min for ClO(-), demonstrating broad linear ranges (0.1-6.0 μM) with ultralow detection limits (6.80 nM for BPO, 5.78 nM for ClO(-)). N-CDs@Eu-MOFs successfully quantified both analytes in five real food matrices, showing recovery rates of 91.94-108.33 % for BPO and 91.25-107.22 % for ClO(-), confirming its reliability in real-world applications. Additionally, portable N-CDs@Eu-MOFs-embedded gel beads were fabricated that facilitate smartphone-based BPO quantification through RGB analysis, achieving recovery rates of 91.41-105.44 % in food samples. This instrument-free approach combines laboratory-grade accuracy with on-site practicality, significantly advancing food safety monitoring.","pmid":"40517657","doi":"10.1016/j.foodchem.2025.145116","url":"https://pubmed.ncbi.nlm.nih.gov/40517657/"},{"id":226,"title":"Hypochlorite-Driven Oxidative Dissolution Boosts Neurodevelopmental Toxicity of Cadmium Sulfide Nanoparticles in Zebrafish.","authors":"Ye, Xiaolin; Xie, Yizhen; Liang, Zhenda; Wang, Shenqing; Zhou, Li; Wang, Xiaohong; Martyniuk, Christopher J; Yan, Bing","year":2025,"date":"2025 Jun 24","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Metal elements in aquatic environments are often transformed into metal sulfide nanoparticles (MSNPs), which are generally considered less toxic due to their low solubility. However, emerging evidence suggests that the oxidative dissolution of MSNPs can lead to the release of toxic metal ions. Here, we investigated the neurodevelopmental toxicity of cadmium sulfide nanoparticles (CdSNPs) in zebrafish under environmentally relevant oxidative conditions induced by hypochlorite, a common disinfectant used in wastewater treatment. We observed that the dissolution of CdSNPs in hypochlorite solutions followed an inverted U-shaped pattern with respect to hypochlorite concentration and reaction time over 24 h. Compared with CdSNP exposure alone, hypochlorite-mediated oxidative dissolution markedly potentiated neurodevelopmental toxicity, evidenced by abnormal light-dark behavioral responses in transgenic hb9:EGFP zebrafish. Mechanistic investigations revealed that the toxicity was primarily driven by dissolved cadmium ions released both in vitro and in vivo, which disrupted serotonergic, dopaminergic, and noradrenergic neurotransmitter systems. Metabolomic profiling and protein expression analyses revealed that cadmium disrupts the synthesis, metabolism, and receptor interactions of monoamine neurotransmitters. This study shows a previously underappreciated mechanism by which oxidative transformation under disinfection-relevant conditions enhances MSNP toxicity, offering critical insights into the ecological and health risks associated with metal sulfide nanoparticles in aquatic systems.","pmid":"40509697","doi":"10.1021/acs.est.4c14507","url":"https://pubmed.ncbi.nlm.nih.gov/40509697/"},{"id":228,"title":"Kinetic stability and transformation pathway of halogenated nitrophenols in drinking water.","authors":"Ge, Jiacheng; Chen, Xiaoyan; Du, Zhenqi; Zhou, Yingying; Qu, Ruixin; Cui, Jiangdong; Ding, Shunke; Chu, Wenhai","year":2025,"date":"2025 Sep 5","journal":"Journal of hazardous materials","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Halogenated nitrophenols (HNPs) have raised significant concerns due to their extensive detection and potent toxicity. Understanding how these compounds persist and degrade over time is crucial for predicting their potential accumulation and assessing the long-term exposure risks. Kinetic studies showed that the degradation of HNPs through hydrolysis and chloramination over realistic hydraulic retention times is relatively low. The species-specific second-order rate constants for the reaction of hypochlorous acid and the acid-catalyzed reaction of hypochlorous acid with anionic HNP species, which accounted for HNP degradation during chlorination, range from 3.84 ± 1.09-363.25 ± 50.44 M⁻¹min⁻¹ and from (1.50 ± 0.091) × 10⁶ to (1.34 ± 0.36) × 10⁸ M⁻²min⁻¹ , respectively. The reactivity order of reactive species in hydrolysis, chlorination, and chloramination with HNP species has also been verified through computational modeling using density functional theory. The introduction of nitro group onto HNPs significantly diminishes the electron density of the benzene ring, thereby reducing their inherent reactivity compared with other aromatic DBPs. The hydrolysis and chlorination of HNPs primarily result in the formation of halogenated hydroquinones and various polyhaloquinones and polyhalophenols, respectively. These results suggest that HNPs and their transformation products exhibit relatively high persistence and exposure risks.","pmid":"40482509","doi":"10.1016/j.jhazmat.2025.138812","url":"https://pubmed.ncbi.nlm.nih.gov/40482509/"},{"id":229,"title":"Efficient phosphonate degradation by Ti(4)O(7) electrode under realistic conditions: Key contribution of HOCl and long-term stability.","authors":"He, Lingyu; Luo, Jiayu; Hu, Haiyang; Zhang, Xin; Lei, Yang","year":2025,"date":"2025 Sep","journal":"Chemosphere","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Using phosphorus-containing scale inhibitors (i.e., phosphonates) in cooling water poses a significant challenge to water pollution and eutrophication during discharge. Here we report an efficient electrochemical oxidation (EO) process based on a low-cost titanium suboxide (Ti(4)O(7)) inert anode. We found that ubiquitous chloride ions (Cl(-)) in cooling water significantly promoted the transformation of methylene phosphonic acid (NTMP, a representative phosphonate) into orthophosphate. In the Cl(-)-Ti(4)O(7)-AO system, hypochlorous acid (HOCl) is the primary reactive species responsible for the sequential cleavage of C-P and C-C bonds, converting organic phosphorus into inorganic phosphate. Furthermore, the presence of HCO(3)(-) or humic acid (HA) under realistic conditions showed negligible effects on the degradation of NTMP. In long-term operation, the Ti(4)O(7)-AO system sustained 100% conversion efficiency of NTMP over continuous-flow operation mode for more than 720 h, even though the cathode was almost entirely covered with CaCO(3) deposits. The results revealed that cathode scaling does not profoundly affect the conversion of organic phosphorus to phosphate in the Ti(4)O(7)-AO system. Overall, our study elucidates the mechanism and robust efficiency of the Cl(-)-Ti(4)O(7)-AO system in treating phosphonate-laden wastewater and offers a new solution for dealing with cooling water by coupling electrochemical oxidation with ubiquitous chloride ions.","pmid":"40472602","doi":"10.1016/j.chemosphere.2025.144510","url":"https://pubmed.ncbi.nlm.nih.gov/40472602/"},{"id":233,"title":"Histones in neutrophil extracellular traps (NETs) contain oxidative post-translational modifications induced by the myeloperoxidase oxidant hypochlorous acid.","authors":"Hemmling, Helen; Hallberg, Line A E; Hägglund, Per; Hawkins, Clare L","year":2025,"date":"2025 Jul","journal":"Redox biology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Extracellular traps (NETs) released by neutrophils during inflammation play a role in clearing infection but also contribute to disease pathology. NETs consist of a DNA backbone containing histones, anti-microbial granule proteins, such as myeloperoxidase (MPO), and other proteins. MPO remains enzymatically active and generates hypochlorous acid (HOCl) to kill pathogens. However, HOCl also readily reacts with proteins, but whether histones and other NET proteins are modified by this oxidant is unknown. This is significant as post-translational modification of histones alters their intracellular and extracellular reactivity. In this study, we used a proteomic approach to characterise the protein composition of NETs and identify HOCl-induced oxidative modifications on histones and other proteins. NETs were collected from primary neutrophils and the PLB-985 cell line and stimulated with phorbol myristate acetate (PMA) or nigericin, a bacterial peptide derived from Streptomyces hygroscopicus. There was evidence for Lys nitrile and aminoadipic semialdehyde formation, Tyr and Trp chlorination, and Met oxidation on histones and other proteins, including quinone oxidoreductase. Chlorination of Tyr-88 on histone H4 was particularly abundant and occurred to a greater extent in NETs from neutrophils exposed to PMA compared to nigericin, consistent with nigericin triggering NET release via a non-oxidative pathway. Chlorination of histone H4 Tyr-88 was also observed in the nuclear and cytoplasmic cell extracts of stimulated cells and could be decreased on treatment of the neutrophils with the MPO inhibitor AZD5904. These findings provide the first evidence that HOCl modifies proteins within NETs, particularly histone H4, which may be relevant in disease.","pmid":"40456203","doi":"10.1016/j.redox.2025.103696","url":"https://pubmed.ncbi.nlm.nih.gov/40456203/"},{"id":239,"title":"High-performance ratiometric fluorescent probe for rapid, visual and ultrasensitive monitoring/bioimaging of hypochlorite in real-life samples and living systems.","authors":"Wang, Tao; Yin, Pengcheng; Jiang, Biaobiao; Niu, Qingfen","year":2025,"date":"2025 Aug 15","journal":"Journal of hazardous materials","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorite (ClO(-)) is a highly reactive chemical extensively used in households, public areas, and various industries due to its multiple functions of disinfection, bleaching, and sterilization. However, overuse of ClO(-) may contaminate the water, soil, air and food, leading to negative impacts on the environments, ecosystems and food safety. Meanwhile, excessive ClO(-) in human body can also cause severe damage to the immune system. Thus, the development of effective and precise detection tools for ClO(-) is of great significance to better understand its complicated roles in environments and biosystems. Herein, a new high-performance ratiometric fluorescent probe 2-amino-3-((10-propyl-10H-phenothiazin-3-yl)methylene)-amino)maleonitrile (PD) was developed for effective detection of ClO(-) in various bio/environmental and food samples. Probe PD exhibits highly-specific \"ratiometric\" fluorescent response to ClO(-) with rapid response (< 1 min), excellent sensitivity (detection limit, 47.4 nM), wide applicable pH range (4 -12), and excellent versatility in practical applications. In practical applications, PD enables the sensitive and quantitative detection of ClO(-) levels in various water samples, bio-fluids, dairy products, fruits and vegetables with high-precision (recoveries, 97.00 -104.40 %), as well as the successful application for visual tracking ClO(-) in fresh fruits and vegetables. Furthermore, test strips containing PD offer a visual and convenient tool for quick identification of ClO(-) in aqueous media by the naked eye. Importantly, the good biocompatibility of PD enables its practical applications in real-time bioimaging of endogenous/exogenous ClO(-) levels in living cells, bacteria, onion cells, Arabidopsis, as well as zebrafish. This study provided an effective method for visual monitoring and bioimaging of ClO(-) levels in various environments, foods and living biosystems.","pmid":"40398030","doi":"10.1016/j.jhazmat.2025.138656","url":"https://pubmed.ncbi.nlm.nih.gov/40398030/"},{"id":240,"title":"Mutation in Staphylococcus aureus that supports gain of function in susceptibility both to hypochlorous acid and to human neutrophils.","authors":"Teghanemt, Athmane; Schilcher, Katrin; Kavanaugh, Jeffery S; Horswill, Alexander R; Nauseef, William M","year":2025,"date":"2025 Jul 9","journal":"Journal of leukocyte biology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Optimal antimicrobial action of human neutrophils (polymorphonuclear leukocytes [PMNs]) relies on the synergy of oxidants and granule proteins, most notably that between the granule protein myeloperoxidase (MPO) and hydrogen peroxide (H2O2) to oxidize chloride anion to produce the potent microbicide, hypochlorous acid (HOCl). However, despite the potency of HOCl, some ingested Staphylococcus aureus cells survive within PMNs and contribute to disease. To identify factors that support the resistance of ingested staphylococci to PMN-oxidative killing, we screened the Nebraska Transposon Mutant Library in the USA300 methicillin-resistant S. aureus strain for mutants that were more sensitive or resistant to HOCl. We identified a mutant in mazF that survived challenge with reagent HOCl better than did the parental strain. In addition, the mutant resisted killing by human PMNs, suggesting that MazF contributes to the susceptibility of S. aureus to HOCl-mediated damage, the ability of S. aureus to recover from HOCl attack, or both. To confirm the genetic basis of the MazF phenotypes, we transformed the mutant with an expression plasmid carrying the wild-type mazF gene or the empty vector control to complement the phenotype. The deletion mutant with the empty vector survived better in reagent HOCl and in PMNs than did the parental strain or the complemented deletion mutant. Taken together, these data suggest that in the absence of mazF expression, USA300 methicillin-resistant S. aureus better resisted, repaired, or both resisted and repaired the sublethal damage produced by HOCl alone or by antimicrobial elements in human PMNs.","pmid":"40388361","doi":"10.1093/jleuko/qiaf057","url":"https://pubmed.ncbi.nlm.nih.gov/40388361/"},{"id":241,"title":"A dual-functional fluorescence probe bearing thiocoumarin ethylene-bridge dicyanopyrone skeleton for detection hydrogen sulfide and hypochlorous acid.","authors":"Yuan, Mengyao; Du, Yongyu; Liu, Mengjie; Wang, Yanjin; Xu, Kuoxi","year":2025,"date":"2025 Aug 15","journal":"Journal of hazardous materials","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Due to the vital roles of hydrogen sulfide and hypochlorous acid in beverage, food, pathology and physiology, the real-time and in situ detection of them have attracted a lot of interest. Herein, a dual-functional fluorescence probe CS was developed containing ethylene-bridge bond of electron donor diethylaminocoumarin and electron acceptor 2-(2,6-dimethyl-4H-pyran-4-ylidene)malononitrile unit. CS exhibited a high specificity, sensitivity (detection limit: 21.64 nM for H(2)S, 0.26 μM for HClO) and rapid response (within 180 s for H(2)S, 25 s for HClO) with a large Stokes shift (125 nm) and good photostability. Meaningfully, the detection mechanism of HClO involved cleavage of N, N-dimethylthiocarbamate and oxidation bridging of ethylene bonds, ultimately forming a unique thiophene ring process. CS has been applied for simultaneous detection of H(2)S and HClO in beverage and food samples. Furthermore, the specific response property of CS for visualization of endogenous and exogenous HClO in cells and mice made it as a powerful tool for investigating a diverse array of HClO-related physiological and pathological processes.","pmid":"40373417","doi":"10.1016/j.jhazmat.2025.138621","url":"https://pubmed.ncbi.nlm.nih.gov/40373417/"},{"id":247,"title":"Generation, fate and transport of volatile chlorine compounds following hypochlorite discharges to municipal sewers.","authors":"Sun, Xiaoyu; Parker, Wayne","year":2025,"date":"2025 Jun","journal":"Chemosphere","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The presence of volatile chlorine compounds in the headspaces of sewers receiving hypochlorite discharges is of concern because of their potential to cause corrosion of infrastructure and risks associated with human exposures. In the current study their presence was investigated using a commercial gas phase Cl(2) sensor. NCl(3) was identified as the most likely gas phase species when ammonia is present and it was found that the Cl(2) sensor was cross-sensitive to this species. The Cl/N ratio substantially impacted gaseous NCl(3) concentrations with maximum values observed at a Cl:N ratio of 12:1. Gaseous NCl(3) concentrations decreased as pH increased (6.5-7.5) and temperature decreased (20-15(o)C). A model that included liquid-gas mass transfer (K(L)a) and first order decay in liquid (k(dl)) and gas (k(dg)) phases was calibrated. The value of k(dl) decreased as the Cl/N ratio increased (10:1-14:1) but increased as pH and temperature increased. Values of k(dl) and K(L)a were lower in real wastewater than in synthetic wastewater. Simulations with a sewer model revealed that with a fixed hypochlorite loading, peak headspace NCl(3) concentrations decreased as wastewater flow increased due to changes in Cl/N ratio. Increased air flow reduced headspace NCl(3) concentrations immediately downstream of the discharge due to dilution but had little effect further downstream. Wastewater pH impacted headspace NCl(3) concentrations by controlling the concentration of NCl(3) in the wastewater. Temperature influenced peak headspace concentrations through its impact on mass transfer and gas phase decay rates. This study provides insights that can be employed to develop sewer use bylaws that regulate hypochlorite discharges.","pmid":"40318526","doi":"10.1016/j.chemosphere.2025.144451","url":"https://pubmed.ncbi.nlm.nih.gov/40318526/"},{"id":248,"title":"A phenothiazine-based ratiometric fluorescent probe for detecting hypochlorite (ClO(-)) and its application in foods and water samples.","authors":"Shen, Siyi; Yuan, Yuehua; Song, Jinping; Zhu, Yongjun; Wang, Yuzhen; Yue, Chaoyi; Du, Mengqing; Wei, Jiyuan; Feng, Feng; Tian, Maozhong","year":2025,"date":"2025 Sep 1","journal":"Food chemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"As a significant reactive oxygen species (ROS), ClO(-) plays versatile roles in daily life and many biological events. However, its abnormal levels are responsible for serious harm to human health. Therefore, it is of crucial interest to develop effective methods for detecting ClO(-) in foods and living organisms. In this work, a novel fluorescent probe ethyl 2-(3-formyl-2-methoxy-10H-phenothiazin-10-yl)acetate (PEA) for detecting ClO(-) was presented. It shows the merits of rapid ratiometric response (within 10 s), high selectivity and very large Stokes shift (190 nm). The detection limit of PEA for ClO(-) was determined to be 0.47 μM. We not only successfully prepared paper test strips for efficient qualitative naked eye ClO(-) detection, but also demonstrated its potential for the valid detection of ClO(-) in natural water samples, beverages and foods. Furthermore, the probe PEA was also applied to the fluorescence imaging of ClO(-) in onion epidermal cells.","pmid":"40311560","doi":"10.1016/j.foodchem.2025.144547","url":"https://pubmed.ncbi.nlm.nih.gov/40311560/"},{"id":249,"title":"Genome-wide characterization of hypothiocyanite stress response in Escherichia coli.","authors":"Meredith, Julia D; Gray, Michael J","year":2025,"date":"2025 May 22","journal":"Journal of bacteriology","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Oxidative stress is one of the major methods of microbial population control and pathogen clearing by the mammalian immune system. The methods by which bacteria are able to escape damage by host-derived oxidants such as hydrogen peroxide (H(2)O(2)) and hypochlorous acid (HOCl) have been relatively well described, while other oxidants' effects on bacteria and their genetic responses are not as well understood. Hypothiocyanite/hypothiocyanous acid (OSCN(-)/HOSCN) is one such oxidative stress agent. In this study, we used RNA-sequencing to characterize the global transcriptional response of Escherichia coli to treatment with HOSCN and the impact of deletions of the HOSCN resistance proteins RclA (HOSCN reductase), RclB, and RclC on that response. The HOSCN response of E. coli was different from the previously characterized responses of E. coli to other oxidants such as H(2)O(2), superoxide, or HOCl and distinct from the reported responses of other bacteria such as Streptococcus pneumoniae and Pseudomonas aeruginosa to HOSCN. Strikingly, deletion of any one of the Rcl proteins had very similar effects on the transcriptional response to HOSCN, indicating that any disruption of HOSCN defense in E. coli results in similar impacts, despite the fact that we do not currently understand the mechanism(s) by which RclB and RclC contribute to that defense. IMPORTANCE: Understanding how bacteria sense and respond to oxidative stress provides insights into how our bodies interact with the microbial population within us. In this study, we have characterized the genetic response of E. coli to the important immune oxidant hypothiocyanite and investigated the role of rclABC genes in that response.","pmid":"40298396","doi":"10.1128/jb.00524-24","url":"https://pubmed.ncbi.nlm.nih.gov/40298396/"},{"id":251,"title":"Exploring the Efficacy of Hypochlorous Acid as a Cost Effective Environmental Decontaminant in Dentistry: A Scoping Review.","authors":"Ahmed, R; Ahmed, S","year":2025,"date":"2025 Apr 1","journal":"Nigerian journal of clinical practice","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"Dental procedures result in the production of bioaerosols that contaminate various environmental surfaces in the dental clinic. In order to maintain a safe environment in the dental clinic and prevent cross contamination, it is important to find alternative disinfection methods and agents to ensure effective decontamination. Hypochlorous acid (HOCl) is a cost-effective antimicrobial agent that can be used for infection control. The purpose of this scoping review is to provide evidence from the literature supporting the routine use of HOCl as a biodecontamination and disinfection agent in dental clinics. An electronic search was completed on the following databases: PubMed, Web of Science, Scopus, Wiley, and Science Direct. The studies were included based on their titles, abstract, and relevance to HOCl and the ability to render pathogens deactivated after exposure to HOCl vapor. The search focused on studies in the past 5 years. The search resulted in a total of 15 articles being selected after exclusions based on duplications, title, and abstract assessment. The articles included studies that used various HOCl concentrations and expanded on the inactivation of several pathogens. The reviewed studies highlight HOCl's broad-spectrum antimicrobial efficacy, with significant reductions in severe acute respiratory syndrome coronavirus 2, methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and Clostridioides difficile, reinforcing its role in optimizing disinfection protocols across healthcare and occupational settings. The articles selected provided clear evidence that under correct and established parameters, HOCl can provide a cheaper safer alternative to most disinfectants. Further studies are recommended on applications methods in clinical settings.","pmid":"40288999","doi":"10.4103/njcp.njcp_674_24","url":"https://pubmed.ncbi.nlm.nih.gov/40288999/"},{"id":255,"title":"Effectiveness of sanitizers on different biofilm-forming microorganisms associated with the poultry drinking water system.","authors":"Ogundipe, Tolulope T; Obe, Tomi","year":2025,"date":"2025 Jul","journal":"Poultry science","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The sanitation of the poultry drinking water system (DWS) is essential to controlling pathogens and biofilms in the DWS. Intervention approaches including several sanitizers have been developed, but there is limited information on the efficacy of some of these sanitizers. The aim of this study was to evaluate the effectiveness of peracid-based (PAB), peroxide-based (PB), and hypochlorite-based (HB) sanitizers against field-isolated Salmonella (10), E. coli (2) and Bacillus (2), along with their antibiofilm effects on six of these bacterial strains on polyvinylchloride (PVC), a common DWS pipe material. The minimum inhibitory and bactericidal concentrations (MIC and MBC) were determined using the microdilution broth method. For biofilm production, PVC rings were inoculated (5-6 Log(10) CFU/mL) in buffered peptone water, incubated at 30°C for 48 h, and detached with cotton swabs for quantification. The antibiofilm effect of the sanitizers was further assessed at MIC, 2X-MIC, 4X-MIC, and water (control). Data was analyzed using ANOVA and Least squares in JMP Pro 18. The MIC and MBC of PAB for all isolates ranged from 11.36 to 28.42 ppm, PB from 15.26 to 71.21 ppm, and HB was 106.67 to 350 ppm. Bacillus licheniformis formed the most biofilm (5.39 Log(10) CFU/mL) as single-species bacteria while Salmonella attached more (6.36 Log(10) CFU/mL) than E. coli (5.41 Log(10) CFU/mL) and Bacillus (2.08 Log(10) CFU/mL) when grown together in mixed cultures. PAB and HB eliminated the biofilms of all strains tested at MIC in mixed-species cultures while PB had no significant effect. Overall, PAB demonstrated the greatest potential as a DWS sanitizer, showing superior efficacy against planktonic and biofilm cells compared to PB and HB. This research highlights the importance of targeted microbial profiling and sanitizer efficacy testing for pre-harvest pathogen control, providing valuable insights for enhancing food safety in poultry production systems.","pmid":"40279691","doi":"10.1016/j.psj.2025.105122","url":"https://pubmed.ncbi.nlm.nih.gov/40279691/"},{"id":257,"title":"A fluorescent chemoprobe based on carbazole for hypochlorite with fast response: Design and its applications in test strips, water samples and living cells.","authors":"Savran, Tahir; Karuk Elmas, Sukriye Nihan; Arslan, Fatma Nur; Sadi, Gökhan; Yilmaz, Ibrahim","year":2025,"date":"2025 Oct 15","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorite (ClO(-)) has been widely used as the main component of cleaning agents, and is also used in the treatment of disinfect water. The concentration of ClO(-) is critical for living organisms andthe environment. Hence, it is essential to develop reliable, sensitive and user-friendly molecular sensors to determine ClO(-). In this context, the synthesized probe 2,4-di-tert-butyl-6-((E)-(((E)-(9-pentyl-9H-carbazol-3-yl)methylene) hydrazono) methyl) phenol (TBCP) can detect ClO(-) with rapid response (1 min), low detection limit (0.28 µM) and high sensitivity. Also, the sensor is utilized at wide pH range (4-10) for the determination of ClO(-). TBCP showed outstanding selectivity for ClO(-) over other competing analytes via a fluorescent response change from colorless to orange, and its response mechanism was based on a deprotonation phenomenon. The ClO(-) level was successfully determined by TBCP on test kits, cotton swabs and in real samples. Fluorescent bio-imaging of ClO(-) in HEPG2 cells was also carried out in the presence of TBCP. Furthermore, DFT calculations were performed successfully for TBCP and TBCP + ClO(-) complex.","pmid":"40262362","doi":"10.1016/j.saa.2025.126243","url":"https://pubmed.ncbi.nlm.nih.gov/40262362/"},{"id":259,"title":"Involvement of purinergic signalling in the vasomotor response to hypochlorous acid in porcine coronary artery.","authors":"Baghdadi, Ashwaq; Dunn, William R; Ralevic, Vera","year":2025,"date":"2025 Oct","journal":"Purinergic signalling","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Hypochlorous acid (HOCl) is generated by neutrophils during the innate immune response. ATP is released from cells by various stimuli and during inflammation but whether ATP is released by and participates in the response to HOCl is unclear. This study investigated vasomotor effects of HOCl on the porcine coronary artery (PCA) and the involvement of ATP and purine receptors. HOCl at 100 μM induced rapid and transient endothelium-dependent relaxation followed by slow and sustained endothelium-independent relaxation. Transient endothelium-dependent relaxation was induced by 500 μM HOCl, followed by endothelium-dependent contraction, then slow endothelium-independent relaxation. 8-(p-sulphophenyl)theophylline (8-SPT), an adenosine/P1 receptor antagonist, blocked rapid relaxation and contraction to HOCl but an A(2A) receptor antagonist, ZM 241385, and an A(1) receptor antagonist, DPCPX, had no effect. Suramin, a P2 receptor antagonist (and membrane channel inhibitor), blocked rapid relaxation (at 100 μM HOCl) and contraction to HOCl. Other antagonists for P2, P2X1, P2Y1 and P2X4 receptors (PPADS, reactive blue 2, NF449, MRS2179 and BX430) did not affect HOCl responses. Relaxation to exogenous ATP was inhibited by 8-SPT but not by suramin suggesting that suramin block of HOCl responses may involve inhibition of membrane channels and endogenous ATP release. Apyrase, which hydrolyzes nucleotides, abolished responses to HOCl, ATP and unexpectedly adenosine. Neither probenecid nor carbenoxelone (connexin and pannexin channel inhibitors) blocked responses to HOCl. Luminescent ATP assay showed that HOCl elicited ATP release from cultures of human coronary artery endothelial cells. These findings advance our understanding of inflammation by showing that HOCl evokes endothelium-dependent vasorelaxation and contraction in coronary arteries which may involve P1 receptors implicating endogenous adenosine, possibly generated from rapid metabolism of ATP released by HOCl.","pmid":"40238052","doi":"10.1007/s11302-025-10086-7","url":"https://pubmed.ncbi.nlm.nih.gov/40238052/"},{"id":260,"title":"Electrochemical Catheter Hub Operated by a Wearable Micropotentiostat Prevents Acinetobacter baumannii Infection In Vitro.","authors":"Al-Qurahi, Majid; Fleming, Derek; Kim, Won-Jun; Bozyel, Ibrahim; Patel, Robin; Beyenal, Haluk","year":2025,"date":"2025 Jul","journal":"Biotechnology and bioengineering","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Intraluminal infection of central venous catheters, used for long-term treatment, can result in central line-associated bloodstream infection (CLABSI). These infections can be challenging to prevent and treat due to formation of biofilms within catheter lumens, which shield bacteria from the human immune response and conventional antimicrobial therapies. Preventing bacterial colonization of catheter hubs is a strategy to prevent CLABSI. To address this, we developed a nonantibiotic, animal-ready electrochemical catheter hub (e-catheter hub), operated by a wearable, battery-powered micropotentiostat (MP), that internally generates tunable hypochlorous acid (HOCl) for preventing intraluminal infection. The design evaluated three different electrode materials-titanium, platinum, and gold-for HOCl generation and biocidal activity, using working and counter electrodes of the same materials and a silver/silver chloride-plated wire as a quasi-reference electrode. e-catheter hubs operated by MPs at 1.5 V(Ag/AgCl) for 3 h generated HOCl, reducing Acinetobacter baumannii ATCC-17978 below the detection limit (average reduction of 4.40 ± 0.05 log(10) CFU/mL). The efficacy of e-catheter hubs operated by MPs in generating HOCl and achieving biocidal activity is comparable to that of a commercial potentiostat. This study represents the first step in developing a localized, nonantibiotic strategy to mitigate CLABSI risk.","pmid":"40235195","doi":"10.1002/bit.28990","url":"https://pubmed.ncbi.nlm.nih.gov/40235195/"},{"id":265,"title":"A dual-responsive ratiometric fluorescent probe for the detection of hypochlorite and hydrazine in environmental samples, live cells, and plant tissues.","authors":"Banik, Dipanjan; Banerjee, Shilpita; Halder, Satyajit; Ganguly, Rajdeep; Karak, Anirban; Ghosh, Pintu; Jana, Kuladip; Mahapatra, Ajit Kumar","year":2025,"date":"2025 Apr 17","journal":"Analytical methods : advancing methods and applications","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorite (ClO(-)), a potent oxidizer and disinfectant, and hydrazine, a powerful reducing agent, are widely used in daily life and various industries. However, their extensive use comes with significant risks, as they are highly toxic to both the environment and human health. They have been associated with various health issues and even linked to cancer. Therefore, the simultaneous detection of hypochlorite and hydrazine is crucial for assessing their impact and monitoring the onset and progression of related diseases. A phenanthroimidazole-indandione based colorimetric and ratiometric fluorescent probe PIID was designed and synthesized for dual channel detection of hypochlorite and hydrazine in environmental and biological samples. Probe PIID, which showed a strong yellow-orange emission at 640 nm with a massive Stokes shift of 220 nm, exhibited excellent fluorescence change from yellow-orange to green (526 nm) in the presence of ClO(-) and from yellow-orange to blue (424 nm) in the presence of hydrazine in an aqueous-THF solvent system. A strong ICT effect, which was acting in probe PIID, gets weakened through ClO(-) - mediated cleavage of the CC bridge bond to produce aldehyde PIB with a blue shift of 114 nm and hydrazine-induced hydrazinolysis of the indanedione moiety to form hydrazone compound PIBH with a blue shift of 216 nm and that was also confirmed by DFT studies. Not only that, the probe exhibits excellent selectivity over other ROS (reactive oxygen species) and amines with a very fast response time of 40 seconds for hypochlorite and 90 seconds for hydrazine, and high sensitivity was observed with detection limits of 32.75 nM for hypochlorite and 92 nM for hydrazine. Moreover, PIID was employed to monitor both the analytes successfully in environmental water samples and in a solid-state TLC strip study. Hypochlorite was monitored in commercial disinfectants, and by exogenous bioimaging in human breast cancer cells (MDA-MB 231) and endogenous bioimaging in RAW 264.7 macrophage cells with very low cytotoxicity and good cell viability. Meanwhile, hydrazine was tracked in soil samples, and confocal imaging was performed on onion tissue.","pmid":"40197602","doi":"10.1039/d5ay00153f","url":"https://pubmed.ncbi.nlm.nih.gov/40197602/"},{"id":269,"title":"Beyond anaerobic respiration-new physiological roles for DmsABC and other S-/N-oxide reductases in Escherichia coli.","authors":"Zhong, Qifeng; Nasreen, Marufa; Yang, Ruizhe; Struwe, Michel; Kobe, Bostjan; Kappler, Ulrike","year":2025,"date":"2025 May 22","journal":"Journal of bacteriology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Sulfoxide reductases in pathogenic bacteria have recently received increasing attention for their association with virulence and survival within the host. Here, we have re-investigated the physiological role of the molybdenum-containing DmsABC dimethyl sulfoxide (DMSO) reductase from Escherichia coli, which has a proposed role in anaerobic respiration with DMSO. Our investigation into potential physiological substrates revealed that DmsABC efficiently reduces pyrimidine N-oxide, nicotinamide N-oxide, and methionine sulfoxide, and exposure to host cell-produced stressors such as hypochlorite or hydrogen peroxide specifically increased expression of the E. coli dmsA gene. E. coli strains lacking dmsA showed increased lag times in the presence of hypochlorite, and these strains also showed up to a 90% reduction in adherence to human bladder cells. Interestingly, in the presence of hypochlorite, expression of multiple alternative S-/N-oxide reductases present in E. coli was elevated by 2- to 4-fold in a ∆dmsA strain compared to the wild-type strain, suggesting functional redundancy. The phenotypes of the E. coli ∆dmsA strains were strikingly similar to ∆dmsA strains of the respiratory pathogen Haemophilus influenzae, which confirms the role of both enzymes in supporting host-pathogen interactions. We propose that this function is conserved in enzymes closely related to E. coli DmsABC. Our study also uncovered that the expression of many E. coli Mo enzymes was induced by oxidative stressors, including metals such as copper, and further work should be directed at determining the connection of these enzymes to host-pathogen interactions.IMPORTANCEBacterial urinary tract infections are debilitating and frequently recurring in human populations worldwide, and Escherichia coli strains are a major cause of these infections. In this study, we have uncovered a new mechanism by which E. coli can avoid being killed by the human immune system. The bacteria use a set of seven related enzymes that can reverse damage to essential cell components such as amino acids, vitamins, and DNA building blocks. Antibacterial compounds produced by the human immune system specifically induced the production of these enzymes, confirming that they play a role in helping E. coli survive during infection and making these enzymes potential future drug targets.","pmid":"40162811","doi":"10.1128/jb.00463-24","url":"https://pubmed.ncbi.nlm.nih.gov/40162811/"},{"id":278,"title":"In-situ quantitative detection of hypochlorous acid in food samples by employing a near-infrared fluorescent probe in association with a portable optical data acquisition system.","authors":"Wang, Yuqing; Zhang, Rumeng; Liu, Wei; Gu, Wuyan; Wang, Kun; Faheem, Muhammad; Wei, Jie; Qian, Jing; Long, Lingliang","year":2025,"date":"2025 May 1","journal":"Analytica chimica acta","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"BACKGROUND: Hypochlorous acid (HClO) is a crucial disinfectant in the food industry. It can be used to soak perishable foods like vegetables, fruits, eggs, fish, and raw meat before processing and storage, eliminating microorganisms, bacteria, fungi, and pathogens to ensure food safety. HClO also helps preserve vegetables and fruits by reducing ethylene production, delaying rotting, decreasing cell membrane permeability, inhibiting polyphenol oxidase activity, and postponing discoloration. However, excessive HClO residues in food can degrade nutrients and pose health risks. Thus, it's urgent to develop an efficient method for in-situ quantitative determination of HClO in various food samples. RESULTS: A colorimetric and near-infrared (NIR) fluorescent probe, YQ, has been developed for HClO. In YQ, the 2-(2-methyl-4H-chromen-4-ylidene) malononitrile conjugated 1,2-dihydrocyclopenta[b]chromen-6-ol acts as a NIR fluorophore, and the O-phenyl methanethioate is incorporated as a new recognition group for HClO. When exposed to HClO, the probe shows highly sensitive and selective NIR fluorescence response with detection limit of 74 nM. It also exhibits significant colorimetric changes after sensing reaction, substantially enhancing detection reliability. The probe has been applied for imaging exogenous and endogenous HClO in living cells. The residual HClO concentrations in lettuce leaves after spraying with different concentrations of HClO solutions were also monitored. Test strips made with YQ enable in-situ HClO detection in water samples. Notably, to accomplish in-situ quantitative detection, a portable optical signal detection system was devised. Probe YQ, together with this self-fabricated system, has been implemented for in-situ quantitative detection of HClO in tomatoes and strawberries. SIGNIFICANCE: Existing methods for quantifying HClO typically require costly equipment, advanced technical skills, and complex sample preparation, making them unsuitable for in-situ quantification. Here, the developed colorimetric and NIR fluorescent probe for HClO avoids background interference from the food matrix and enhances detection reliability. More importantly, when coupled with the self-made portable optical signal detection system, this probe can be served as a powerful tool for in-situ quantitative measurement of HClO in diverse foods.","pmid":"40074461","doi":"10.1016/j.aca.2025.343844","url":"https://pubmed.ncbi.nlm.nih.gov/40074461/"},{"id":280,"title":"Eficacia y seguridad del ácido hipocloroso pH 5,5 en el manejo de heridas complejas en usuarios pediátricos.","authors":"Sánchez, María Carolina Medel; Contreras, Ilia Merino; González, Carolina Latorre; Durán, Bárbara Ampuero","year":2024,"date":"2024 Jun 1","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Serie de casos que sugieren los beneficios de la implementación de una solución limpiadora no citotóxica de pH ácido en el tratamiento de heridas complejas en usuarios pediátricos en dos centros de salud de Santiago, Chile. Se propone como tratamiento adicional al manejo etiológico el uso de una solución limpiadora compuesta de ácido hipocloroso (HOCl) en una concentración de 330 ppm y pH 5,5 (Vashe® Wound Solution, Urgo Medical, Texas, Estados Unidos) la cual ha demostrado ser segura y efectiva en el manejo de heridas en usuarios pediátricos. Se evidencian beneficios significativos en términos de cicatrización acelerada y reducción del dolor en los casos tratados. Aunque existen limitaciones en la evidencia actual, los resultados preliminares sugieren que el HOCl pH 5,5 puede ser una opción terapéutica efectiva en el manejo de heridas y alteraciones cutáneas en el usuario pediátrico.","pmid":"40072930","doi":"10.12968/jowc.2024.33.latam_Sup_7.6","url":"https://pubmed.ncbi.nlm.nih.gov/40072930/"},{"id":282,"title":"Taurine supplementation alleviates asthma airway inflammation aggravated by HOCl exposure.","authors":"Chen, Yingjun; Yi, Shiting; Wang, Qian; Li, Yanwen; Lin, Sitong; Liang, Shixiu","year":2025,"date":"2025 Jun 15","journal":"Journal of hazardous materials","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Environmental pollutant exposure has been demonstrated to be associated with the onset and progression of asthma. Hypochlorous acid (HOCl), as an environmental exposure-relevant chlorine-based disinfectant, its role in asthmatic airway inflammation remains unclear. Through administering HOCl in drinking water during early life and the perinatal period, we discovered that early-life HOCl drinking water exposure not only aggravated airway inflammation in asthmatic mice but also that perinatal HOCl drinking water exposure could promote airway inflammation in the offspring of asthmatic mice. By gut microbiota sequencing, it was found that HOCl drinking water exposure could reduce the gut microbiota diversity in asthmatic mice, with the abundances of Lactobacillus, Faecalibaculum, Muribaculum, and [Eubacterium]_ventriosum_group being decreased, while increasing the abundances of Dubosiella and Parabacteroides. Further fecal metabolomics analysis revealed that HOCl drinking water exposure significantly enhanced the arachidonic acid metabolism pathway. And there was a certain correlation between the abundances of the significantly altered bacterial genera and the levels of arachidonic acid metabolites. Finally, treatment with taurine, a HOCl neutralizer, showed that taurine could significantly alleviate the asthma airway inflammation aggravated by HOCl exposure. In summary, these results provide evidence for the exacerbation of asthma airway inflammation by HOCl exposure and confirm that taurine supplementation can serve as a potential therapeutic approach.","pmid":"40058197","doi":"10.1016/j.jhazmat.2025.137796","url":"https://pubmed.ncbi.nlm.nih.gov/40058197/"},{"id":285,"title":"Boosting hypochlorite's disinfection power through pH modulation.","authors":"Sil, Timir Baran; Malyshev, Dmitry; Aspholm, Marina; Andersson, Magnus","year":2025,"date":"2025 Feb 28","journal":"BMC microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"PURPOSE: Hypochlorite-based formulations are widely used for surface disinfection. However, the efficacy of hypochlorite against spore-forming bacteria varies significantly in the literature. Although neutral or low pH hypochlorite solutions are effective sporicides due to the formation of hypochlorous acid (HOCl), their optimal conditions and the specific role of pH in disinfection remain unclear. These conditions also increase the solution's corrosiveness and compromise its shelf life. Therefore, further research is needed to identify the pH conditions that balance solution stability and effective hypochlorite-based spore disinfection. RESULTS: This study investigates the impact of neutral to alkaline pH on the sporicidal efficiency of hypochlorite against a pathogenic Bacillus cereus strain. We apply a 5,000 ppm hypochlorite formulation for 10-min across a pH range of 7.0-12.0, simulating common surface decontamination practices. Our results demonstrate that hypochlorite is largely ineffective at pH levels above 11.0, showing less than 1-log reduction in spore viability. However, there is a significant increase in sporicidal efficiency between pH 11.0 and 9.5, with a 4-log reduction in viability. This pH level corresponds to 2 - 55 ppm of the HOCl ionic form of hypochlorite. Further reduction in pH slightly improves the disinfection efficacy. However, the shelf life of hypochlorite solution decreases exponentially below pH 8.5. To explore the pH-dependent efficacy of hypochlorite, Raman spectroscopy and fluorescence imaging were used to investigate the biochemical mechanisms of spore decontamination. Results showed that lower pH enhances spore permeability and promotes calcium dipicolinic acid (CaDPA) release from the core. CONCLUSION: Our results highlight the complex relationship between pH, sporicidal efficacy of hypochlorite, and its shelf life. While lower pH enhances the sporicidal efficiency, it compromises the solution's shelf life. A pH of 9.5 offers a balance, significantly improving shelf life compared to previously suggested pH ranges 7.0-8.0 while maintaining effective spore inactivation. Our findings challenge the common practice of diluting sodium hypochlorite with water to a 5,000 ppm solution, as this highly alkaline solution (pH of 11.9), is insufficient for eliminating B. cereus spores, even after a 10-min exposure. These findings are critical for improving disinfection practices, highlighting the importance of optimizing sodium hypochlorite effectiveness through pH adjustments before application.","pmid":"40021972","doi":"10.1186/s12866-025-03831-w","url":"https://pubmed.ncbi.nlm.nih.gov/40021972/"},{"id":294,"title":"Reactions of oxazepam with two typical water treatment oxidants in aqueous solutions: Results based on density functional theory.","authors":"Zhang, Ling-Ling; Dai, Hong-Yu; Peng, Tao; Liu, Xiao-Yuan; Zhou, Zhi-Cheng; Xu, Chao; Yang, Bin; Ying, Guang-Guo","year":2025,"date":"2025 Mar","journal":"Chemosphere","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Pharmaceutical residues in the environment and their transformation mechanism are important challenges in environmental pollution research. The present study investigated the transformation mechanisms and reaction kinetics of oxazepam, a representative of benzodiazepine pharmaceutical, with two typical water treatment oxidants including HOCl and ∙OH in aqueous solution through theoretical calculations and experimental verification. The results showed that oxazepam is a chiral molecule with two enantiomers in equal proportions. The reactions between oxazepam and HOCl can be classified into Cl-substitution, OH-substitution, and bond-fission reactions. Among these substitutions, the Cl-substitution reaction at the N23 site was most likely to occur. The bond-fission reactions were predominated by the cleavage of the C27-N29 bond, which could lead to further bond cleavage reactions. The reactions between oxazepam and ∙OH involved the addition and H-abstraction pathways, with the addition reactions at the C5, C13, and C17 sites being the top three major reaction pathways. The kinetics rate constants obtained by the density functional theory (DFT) calculation were 0.16 and 1.78 × 10(11) M(-1) s(-1) for the reactions of oxazepam with HOCl (k(HOCl), M(-1) s(-1)) and ∙OH (k(·OH), M(-1) s(-1)) respectively, which are basically consistent with the experimental results. This comprehensive understanding of the reaction mechanisms of oxazepam with HOCl and ∙OH based on quantum chemical calculations is crucial for exploring the chlorination and advanced oxidation of benzodiazepine pharmaceuticals.","pmid":"39914085","doi":"10.1016/j.chemosphere.2025.144182","url":"https://pubmed.ncbi.nlm.nih.gov/39914085/"},{"id":295,"title":"Construction of a flavonol-based colorimetric and fluorescent probe with large Stokes shift for detecting hypochlorous acid in foodstuffs and imaging in living cells, zebrafish and plants tissues.","authors":"Xu, Tongtong; Liang, Yueyin; Gong, Shuai; Meng, Zhiyuan; Zhang, Yan; Huang, Shun; Liu, Tianqi; Wang, Shifa; Wang, Zhonglong","year":2025,"date":"2025 May 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The excessive addition of hypochlorous acid (HClO) during food preservation can reduce the nutritional value of foodstuffs, and its abnormal levels in organisms will affect normal physiological and pathological activities. Herein, an efficient fluorescent probe HTTPC for monitoring HClO in foodstuffs and biosystems has been developed from natural flavonol. HTTPC itself emitted intense orange fluorescence emission in nearly 100 % aqueous solution, and it underwent a remarkable fluorescence quenching effect after being treated with HClO. HTTPC could selectively recognize HClO over other different biologically relevant species. Moreover, HTTPC featured many distinguished sensing properties, including large Stokes shift (184 nm), low detection limit (4.7 nM), strong anti-interference capability and rapid response to HClO (10 s). Furthermore, HTTPC can serve as a potential approach for qualitative determination of HClO residues within foodstuffs with good recoveries. HTTPC exhibited outstanding biocompatibility and low cytotoxicity, and it could successfully achieve the real-time fluorescence imaging of HClO fluctuations within live HeLa cells, zebrafish and onion tissues.","pmid":"39893736","doi":"10.1016/j.saa.2025.125800","url":"https://pubmed.ncbi.nlm.nih.gov/39893736/"},{"id":312,"title":"A 12-month retrospective review of pressure injury plastic surgical flap techniques utilizing pure hypochlorous acid (pHA) preserved wound solution for wound bed preparation.","authors":"Fligor, Caleb W; Duplechain, Abby B; Chaffin, Abigail E","year":2024,"date":"2024 Dec","journal":"Wound management & prevention","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: The presence of heavy microbial colony formation, polymicrobial infection, and local altered pH contribute to the high rate of postoperative complications following surgical reconstruction of stage IV pressure injuries (PIs). PURPOSE: The objective of this study was to determine the rate of bacteria-related postoperative complications following surgical reconstruction of stage IV PIs in which a pure hypochlorous acid (pHA) antimicrobially preserved wound cleaning solution was used. METHODS: This 1-year retrospective review evaluated the outcomes of patients who underwent surgical reconstructive treatment of chronic stage IV PI. Surgical management consisted of wide debridement, intraoperative cultures, and irrigation with 8 to 10 minutes indwelling of a pHA antimicrobially preserved wound cleaning solution prior to closure and application of incisional negative pressure wound therapy (iNPWT). RESULTS: Thirteen patients (18 chronic, stage IV PIs) were included in the study. Intraoperative cultures were positive for 10/18 wounds (55.6%). A bacteria-related postoperative complication occurred in 1 patient (1/13, 7.7%; postoperative dehiscence requiring reoperation). CONCLUSIONS: Adjunctive irrigation and indwelling of a pHA antimicrobially preserved wound cleansing solution in the surgical management of chronic, stage IV PIs in this 1-year retrospective review resulted in a 7.7% bacteria-related postoperative complication rate.","pmid":"39788876","doi":"10.25270/wmp.24001","url":"https://pubmed.ncbi.nlm.nih.gov/39788876/"},{"id":313,"title":"Inactivation Effects of Hypochlorous Acid, Chlorine Dioxide, and Ozone on Airborne SARS-CoV-2 and Influenza A Virus.","authors":"Imoto, Yasuo; Matsui, Hidehito; Ueda, Chihiro; Nakajima, Eri; Hanaki, Hideaki","year":2025,"date":"2025 Jan 3","journal":"Food and environmental virology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A virus are primarily transmitted through droplets or aerosols from patients. The inactivation effects of existing virus control techniques may vary depending on the environmental factors. Therefore, it is important to establish a suitable evaluation system for assessing virus control techniques against airborne viruses for further real-world implementation. This study aimed to assess the inactivating effects of chemical substances on SARS-CoV-2 and influenza A virus in the air using an established evaluation system. A mixture containing SARS-CoV-2 and influenza A virus in diluted saliva was nebulized into the designed 1 m(3) chamber, and the virucidal effects of hypochlorous acid, chlorine dioxide, and ozone in the air samples at 23 ± 1 °C with 50 ± 5% relative humidity were determined using the plaque assay. Both viral infectivity titers decreased depending on chemical substance concentration and exposure time. The concentrations of hypochlorous acid, chlorine dioxide, and ozone in the air reached an approximately 2-log reduction of SARS-CoV-2 infectivity titer within 10 min at 0.02, 1.0, and 1.0 ppm, respectively. SARS-CoV-2 persisted in the air even under conditions where the influenza A virus was inactivated below the detection limits. These findings demonstrate that hypochlorous acid, chlorine dioxide, and ozone are effective in inactivating SARS-CoV-2 and influenza A virus in the air.","pmid":"39752095","doi":"10.1007/s12560-024-09626-y","url":"https://pubmed.ncbi.nlm.nih.gov/39752095/"},{"id":321,"title":"Residual level of chlorine disinfectant, the formation of disinfection by-products, and its impact on soil enzyme activity.","authors":"Hua, Li; Wei, Xinlong; Wang, Meiting","year":2024,"date":"2024 Dec 18","journal":"Environmental geochemistry and health","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Disinfectants can kill pathogenic microorganisms, effectively block the spread of infectious diseases, and are widely used during epidemics. However, a little has been studied about the environmental hazards caused by the heavy use of disinfectants. In this paper, the residual situation of chlorine ions in the soil, possible disinfection by-products (DBPs), and effects on soil enzyme activities after using 84 disinfectants (main component: sodium hypochlorite) and hypochlorite disinfectant (main component: hypochlorous acid) were investigated. It was found that the residual rates were generally higher than 92% for the 84 disinfectant treatment and between 80% ~ 90% for the hypochlorite disinfectant treatments. The overall change in chlorine ion concentration in the soil-leaching solution of the hypochlorite disinfectant treatments was relatively small and stable compared to the 84 disinfectant treatments. Several types of trihalomethanes (THMs) were detected after 24 h of disinfection. The generation concentration of THMs was higher for the 84 disinfectant than for the hypochlorite disinfectant. The generation of trichloromethane was the highest, ranging from 1000 to 3000 μg/L. Soil enzyme activities changed much when the soil was treated with the disinfectant for 28 days. The above results indicated that hypochlorite disinfectant was safer and more stable than 84 disinfectants, and trichloromethane should be strictly controlled as a key indicator among the disinfection by-products. In addition, the long-term application of disinfectants affects soil enzyme activities obviously.","pmid":"39692919","doi":"10.1007/s10653-024-02337-0","url":"https://pubmed.ncbi.nlm.nih.gov/39692919/"},{"id":323,"title":"In Vitro and In Vivo Translational Insights into the Intraoperative Use of Antiseptics and Lavage Solutions Against Microorganisms Causing Orthopedic Infections.","authors":"Dudek, Bartłomiej; Brożyna, Malwina; Karoluk, Michał; Frankiewicz, Mariusz; Migdał, Paweł; Szustakiewicz, Konrad; Matys, Tomasz; Wiater, Adrian; Junka, Adam","year":2024,"date":"2024 Nov 26","journal":"International journal of molecular sciences","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The growing antibiotic resistance of microorganisms causing postoperative infections following orthopedic surgeries underscores the urgent need for localized antiseptic and lavage delivery systems to enhance infection control. This study evaluates the in vitro effectiveness of antiseptic and lavage solutions-including polyhexanide, povidone-iodine, low-concentrated hypochlorite, Ringer's solution, and saline-against Staphylococcus epidermidis, Staphylococcus aureus MRSA, Cutibacterium acnes, Corynebacterium amycolatum, Pseudomonas aeruginosa, and Candida albicans. Using microplate models (Minimum Inhibitory Concentration, Minimum Biofilm Eradication Concentration, and Biofilm-Oriented Antiseptic Test assays), flow-based models (Bioflux system), and surfaces relevant to orthopedic implants (e.g., stainless steel disks/screws, Co-Cr-Mo, Ti-Al-Nb orthopedic alloys, and ultra-high-molecular-weight polyethylene), as well as a bio-nano-cellulose scaffold representing tissue, we assessed the solutions' activity. The cytotoxicity of the solutions was evaluated using osteoblast and keratinocyte cell lines, with additional in vivo insights gained through the Galleria mellonella larval model. The results show that polyhexanide-based solutions outperformed povidone-iodine in biofilm eradication in most tests applied, particularly on complex surfaces, whereas iodine demonstrated higher cytotoxicity in applied in vitro and in vivo tests. Low-concentration hypochlorite solutions exhibited minimal antibiofilm activity but also showed no cytotoxicity in cell line and G. mellonella larval models. These findings highlight the importance of careful antiseptic selection and rinsing protocols to balance infection control efficacy with tissue compatibility in orthopedic applications.","pmid":"39684431","doi":"10.3390/ijms252312720","url":"https://pubmed.ncbi.nlm.nih.gov/39684431/"},{"id":325,"title":"A selenium-based fluorescent sensor for the reversible detection of ClO(-) and H(2)S in foods.","authors":"Shen, Siyi; Tian, Maozhong; Xia, Wenhui; Song, Jinping; Wang, Yuzhen; Wei, Jiyuan; Wang, Xiaohui; Yuan, Yuehua; Feng, Feng","year":2025,"date":"2025 Mar 15","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"HClO/ClO(-) and H(2)S are two kinds of momentous biological small molecules in the organism, and the redox balance between them is considerable for the physiological and pathological properties of organisms. Hence, it is very crucial to monitor the redox course between HClO and H(2)S. Herein, a reversible fluorescent sensor (IPSe) for ClO(-) and H(2)S was firstly constructed with the selenium atom as the response site and the dicyanoisophorone as the fluorophore. The sensor IPSe could detect ClO(-) with good selectivity and sensitivity due to the oxidation reaction of the selenium atom triggered by ClO(-). The recognition of IPSe to hypochlorite induced a hypsochromic shift of the absorption maximum from 420 nm to 380 nm. IPSe exhibited the prominent low detection limit of 55.3 nM for detecting ClO(-), accompanied by distinct fluorescent attenuation. Moreover, H(2)S could efficiently return the fluorescence of the IPSe solution to the original level by H(2)S reducing selenoxide. The experimental results show that the suggested method has high precision and accuracy for the detection of ClO(-) and H(2)S. The applications in real water samples, beverages and cell imaging verified that the IPSe was capable of monitoring the changes in the concentration of ClO(-)/H(2)S, which indicates that it is of great meaning to survey the biological functions of ClO(-) and H(2)S via IPSe.","pmid":"39674110","doi":"10.1016/j.saa.2024.125570","url":"https://pubmed.ncbi.nlm.nih.gov/39674110/"},{"id":327,"title":"Efficient removal of manganese ions from waters using hypochlorite-modified granular activated carbon.","authors":"Chang, Ying-Ju; Huang, Chihpin; Chang, Jo-Shu; Lee, Duu-Jong","year":2025,"date":"2025 Jan","journal":"Journal of environmental management","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Conventional drinking waterworks generally disregard the manganese removal efficiencies. For the first time, this study demonstrates the potential of ClO(-)-modified activated carbon for efficient Mn removal from raw water. The 10% NaClO-modified granular activated carbon increases the Mn(2+) adsorption capacity from 4.28 mg/g to 28.1 mg/g at an initial Mn concentration of 50 mg/L at pH 7 and 25 °C. Conversely, applying strong acids, bases, oxidants, or microwave treatments adversely impacts the adsorption capacity of the modified activated carbon. The kinetic adsorption tests and equilibrium measurements reveal increased Mn(2+) adsorption capacities with ClO(-) concentration and initial Mn(2)⁺ concentration, peaking at 35 °C. The mechanistic studies show that the chemical complexation with the C=C bonds on the carbon's surface from ClO(-)-modification principally contributes to the enhanced Mn(2)⁺ adsorption. Jar tests demonstrate that 5% NaClO-modified activated carbon can completely remove 0.3 mg/L Mn(2+) or over 98% of 1 mg/L Mn(2)⁺ in the presence of competing Fe(2)⁺ ions. The ClO-modified granular activated carbon has excellent potential for practical drinking water production since all materials used are certified by the National Sanitation Foundation (NSF).","pmid":"39657478","doi":"10.1016/j.jenvman.2024.123577","url":"https://pubmed.ncbi.nlm.nih.gov/39657478/"},{"id":328,"title":"Electrolyzed Saline Prevents Virus Transmission in Dental Procedures: An In Vitro Study.","authors":"Munjaković, H; Mikuletič, T; Zayed, N; Kolenc, M; Manevski, D; Triglav, T; Steyer, A; Teughels, W; Seme, K; Fidler, A; Gašperšič, R","year":2025,"date":"2025 Feb","journal":"Journal of dental research","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"In dentistry, disinfection with antimicrobials is employed under different conditions and at different time points. During the COVID-19 pandemic, the use of disinfectant dental sprays was proposed, among other measures, to help prevent the transmission of infections during dental procedures that require highly effective antiseptics at particularly short contact times. The study aimed to evaluate the efficacy of electrolyzed saline (EOS) compared with other antiseptics in terms of the spread of enveloped and nonenveloped viruses by ultrasonic scaler (USS)-generated dental spray. Suspension tests were performed to evaluate the antiviral efficacy of EOS against herpes simplex virus 1 (HSV-1) and human adenovirus (HAdV), which served as models for enveloped and nonenveloped viruses, respectively. EOS, mostly composed of hypochlorous acid (HOCl), reduced the amount of both virus types in the presence or absence of artificial saliva by > 4 log(10) 50% tissue culture infectious dose (P < 0.001). In addition, the mechanism of virucidal effect was investigated using transmission electron microscopy. Following this assessment, a virus-laden dental spray transmission model was used to simulate virus-infected patients undergoing dental procedures with USS. Attenuation was achieved by substituting the USS coolant with one of the effective, pretested antiseptics. Due to safety concerns, nonhuman viral pathogens-equine arteritis virus (EAV) and feline calicivirus (FCV)-served as enveloped and nonenveloped virus models, respectively. Viral infection was evaluated by direct droplet/aerosol infection of RK-13 or CRFK cells. In addition, the biocompatibility of the antiseptics was tested with exposure to human oral keratinocytes. EOS demonstrated strong virucidal activity against both enveloped and nonenveloped viruses and was able to absolutely prevent airborne transmission of EAV and FCV through dental spray in the splatter and droplet/aerosol samples. The study emphasized that EOS, a chlorine-based antiseptic, is a promising, reasonably safe, broad-spectrum agent for preventing dental spray-mediated viral transmission.","pmid":"39639474","doi":"10.1177/00220345241296071","url":"https://pubmed.ncbi.nlm.nih.gov/39639474/"},{"id":341,"title":"A dual-functional rhodamine B and azo-salicylaldehyde derivative for the simultaneous detection of copper and hypochlorite: synthesis, biological applications and theoretical insights.","authors":"S, Vishnu; Das, Avijit Kumar; Bylappa, Yatheesharadhya; Nag, Anish; Dolai, Malay","year":2024,"date":"2024 Dec 5","journal":"Analytical methods : advancing methods and applications","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"A multifunctional rhodamine derivative containing azo-salicylaldehyde (BBS) was designed and synthesized as a colorimetric and fluorescence turn-on probe for the selective detection of copper cations (Cu(2+)) and hypochlorite anions (OCl(-)) in aqueous media. In the presence of Cu(2+), the probe BBS exhibited turn-on absorption and fluorescence change at 554 nm and 585 nm, respectively. The binding mechanism of BBS with Cu(2+) induces the opening of a spirolactam ring in the rhodamine moiety by the formation of a metal-ligand complex, achieving 10-fold enhancement in fluorescence and quantum yield, along with a binding constant of 1 × 10(4) M(-1) and a detection limit of 2.61 μM. Addition of OCl(-) enhanced the absorbance and fluorescence intensities at 520 nm and 575 nm, respectively. The probe BBS underwent hypochlorite-mediated oxidation, followed by hydrolysis, resulting in the formation of rhodamine B itself, which is detectable by the naked eye via the color and fluorescence enhancement by 11-fold with a high quantum yield and a detection limit of 1.96 μM. For practical applications, sensor BBS can be used to detect Cu(2+) in water samples and on cotton swabs. For biological applications, the interaction of the BBS-Cu(II) complex with transport proteins such as bovine serum albumin (BSA) and ct-DNA was investigated through UV-vis and fluorescence titration experiments. Additionally, the structural optimization of BBS and the BBS-Cu(II) complex was demonstrated using DFT, and the interactions of the BBS-Cu(II) complex with BSA and ct-DNA were analysed through theoretical docking studies. Bioimaging studies were conducted by capturing fluorescence images of BBS with Cu(2+) and OCl(-) in a physiological medium containing living plant tissue using green gram seeds.","pmid":"39508779","doi":"10.1039/d4ay01758g","url":"https://pubmed.ncbi.nlm.nih.gov/39508779/"},{"id":344,"title":"A colorimetric fluorescent probe for reversible detection of HSO(3)(-)/H(2)O(2) and effective discrimination of HSO(3)(-)/ClO(-) and its application in food and bioimaging.","authors":"Gao, Yuexing; Peng, Yan; Shi, Lei; Zhang, Siyun; Bai, Ruiyang; Lang, Yunhe; He, Yonggui; Zhang, Buyue; Zhang, Ziyi; Zhang, Xiufeng","year":2025,"date":"2025 Feb 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"In view of the significant role of reactive sulfur species (RSS) and reactive oxygen species (ROS) in maintaining the redox homeostasis of organisms, we proposed a colorimetric fluorescent probe (HTN) for reversible detection of HSO(3)(-)/H(2)O(2) and effective discrimination of HSO(3)(-)/ClO(-). C = C is the active site for the Michael addition of HSO(3)(-) and the oxidation of ClO(-). When HTN interacts with HSO(3)(-) and ClO(-), it exhibits fluorescence quenching. The addition of oxidizing H(2)O(2) to the system can restore the conjugate structure of the addition product of HSO(3)(-) (HTN-HSO(3)(-)) and the fluorescence recovery, but it cannot restore the structure of the oxidation product of ClO(-) (HTN-ClO(-)). By studying the change of the reversibility/non-reversibility of the probe structure with the addition of H(2)O(2), the purpose of reversible detection of HSO(3)(-)/H(2)O(2) and distinguishing HSO(3)(-)/ClO(-) is achieved. In addition, HTN can not only be used as a fluorescent ink to detect HSO(3)(-) on the test paper, but also has excellent detection effect on HSO(3)(-) and ClO(-) in real food samples and water samples. Meantime, HTN has good biocompatibility and can target mitochondria to achieve reversible detection of HSO(3)(-)/H(2)O(2) and effective discrimination of HSO(3)(-)/ClO(-) in living cells. Therefore, HTN has great potential as a molecular tool for studying redox homeostasis in the interaction network of complex living systems.","pmid":"39481270","doi":"10.1016/j.saa.2024.125275","url":"https://pubmed.ncbi.nlm.nih.gov/39481270/"},{"id":346,"title":"The economic and quality effects of wound cleansing with pure hypochlorous acid: evidence-based evaluation and clinical experience.","authors":"Mallow, Peter J; Black, Joyce; Chaffin, Abigail E; Couch, Kara S; Faust, Elizabeth; Fernández, Luis G; Gallagher, Kathy E; Lam, Loan; Niezgoda, Jeffrey A; Weir, Dot","year":2024,"date":"2024 Oct","journal":"Wounds : a compendium of clinical research and practice","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Chronic or hard-to-heal wounds fail to proceed through an orderly and timely healing process, resulting in a lack of anatomic and functional integrity. Infection is a common driver of nonhealing processes; therefore, infection prevention and management are essential components to healing chronic wounds. Inexpensive specialized cleansers, such as pure hypochlorous acid (pHA), can be used to cleanse vulnerable wounds to reduce microbial burden, thereby reducing the risk of infection and significantly decreasing the likelihood of the patient developing a costly wound complication. OBJECTIVE: To report the findings of an expert panel composed of 10 health care professionals (HCPs) from diverse medical specialties convened to discuss the use of pHA in various care settings. METHODS: During the panel discussion, experienced HCPs presented specific case examples in which pHA was used, along with associated costs. RESULTS: A major theme of the panel discussion was the widespread benefit of pHA across various types of wounds and wound care settings. In addition, the patient cases illustrated a negligible economic impact of pHA coupled with positive effects on patient outcomes. This work did not include the development of a consensus statement. CONCLUSION: Together, the information presented in the panel discussion supports pHA as a dominant strategy (more effective, less costly) compared with standard wound management practices in many treatment settings.","pmid":"39432725","doi":"10.25270/wnds/24101","url":"https://pubmed.ncbi.nlm.nih.gov/39432725/"},{"id":352,"title":"Development of optimal indoor air disinfection and ventilation protocols for airborne infectious diseases.","authors":"Park, Jooyeon; Lee, Kyoung Hwa; Song, Young Goo; Park, Hyungmin; Lee, Kwang Suk","year":2024,"date":"2024","journal":"PloS one","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Since the COVID-19 pandemic, there has been persistent emphasis on the importance of indoor air disinfection and ventilation in isolation units in the hospital environment. Nevertheless, no optimal and concrete disinfection protocol has been proposed to inactivate the viruses as quickly as possible. In this study, we experimentally evaluated various ventilation and disinfection protocols based on the combination of negative-pressure ventilation, ultraviolet (UV) light illumination, and Hypochlorous acid (HOCl) spray against three active virus species in a 3.5 cubic meters isolation unit. This small-size unit has gained attention during the pandemic due to the high demand for compact mobile laboratory systems capable of rapid disease diagnosis. In accordance with the WHO laboratory biosafety guidance, which states that all enclosed units where diagnostic work is conducted must ensure proper ventilation and disinfection activities, we aim to propose virus removal protocols for units compact enough to be installed within a van or deployed outdoor. The results confirmed the superiority (in terms of virus removal rate and time required) of the virus removal methods in the order of UV light, ventilation, and HOCl spray. Ultimately, we propose two optimal protocols: (i) UV light alone for three minutes, and (ii) UV light with ventilation for three minutes, followed by one-minute ventilation only. The time span of three minutes in the latter protocol is based on the clinical practice such that the medical staffs have a sufficient time to process the samples taken in transition to next patient to care.","pmid":"39352895","doi":"10.1371/journal.pone.0311274","url":"https://pubmed.ncbi.nlm.nih.gov/39352895/"},{"id":354,"title":"Dual action electrochemical bandage operated by a programmable multimodal wearable potentiostat.","authors":"Bozyel, Ibrahim; Fleming, Derek; Won-Jun, Kim; Rosen, Peter F; Gelston, Suzanne; Ozdemir, Dilara; Kies, Paige; Koscianski, Christina; Karau, Melissa; Ay, Suat U; Patel, Robin; Beyenal, Haluk","year":2025,"date":"2025 Jan 1","journal":"Biosensors & bioelectronics","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"We have developed electrochemical bandage (e-bandage) prototypes that generate the reactive oxygen species hypochlorous acid (HOCl) or hydrogen peroxide (H(2)O(2)) for potential use to treat biofilm-infected wounds in humans. We have shown that both e-bandage-generated HOCl and H(2)O(2) kill biofilms in vitro and in infected wounds on mice, with the former being more active in vitro. The H(2)O(2)-generating e-bandage, more so than the HOCl-generating e-bandage, was associated with improved healing of infected wounds. Here, a strategy in which H(2)O(2) and HOCl are alternately generated-for dual action-was explored. The goal was to develop a programmable multimodal wearable potentiostat [PMWP] that can generate HOCl or H(2)O(2), as needed. An ultralow-power microcontroller unit was developed to manage operation of the PMWP. The system was operated with a 260-mAh capacity coin battery and weighed 4.6 g, making it suitable for future small animal experiments (and ultimately, potential evaluation in humans). As assessed using electrochemical parameters, the device functioned comparably to a commercial benchtop potentiostat. To confirm antimicrobial activity, PMWP-controlled e-bandages were tested in vitro against clinical isolates of methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus faecium, and Candida auris. When programmed to deliver HOCl followed by H(2)O(2), PMWP-controlled e-bandages exhibited activity against biofilms of all study isolates tested. Finally, we demonstrated the PMWP's usability in a murine wound infection model.","pmid":"39342698","doi":"10.1016/j.bios.2024.116791","url":"https://pubmed.ncbi.nlm.nih.gov/39342698/"},{"id":355,"title":"A novel ratiometric colorimetric sensor for detecting hypochlorite and ascorbic acid based on cascade reaction.","authors":"Sun, Miaowen; Liu, Yanzhu; Shi, Lingge; Dou, Haomiao; Ma, Feiyan; Xu, Guangda; Zhao, Longshan","year":2025,"date":"2025 Jan","journal":"Analytical biochemistry","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Hypochlorite and ascorbic acid (AA), play an indispensable role in numerous physiological activities. Herein, a ratiometric colorimetric sensing strategy for the determination of hypochlorite and AA was developed via the catalytic oxidation and reduction of 3,3',5,5'-tetramethylbenzidine (TMB). Interestingly, in the presence of Fe(3)O(4)-MOF-5(Fe) and hypochlorite, TMB complexes in acidic environments were oxidized to blue oxidized TMB and further diazotized to produce yellow-green diazotized TMB, resulting in the hypochlorite concentration-dependent ratiometric variation for the absorbance at 652 and 450 nm (A(450)/A(652)). Moreover, the diazotized TMB was restored to colorless TMB due to the reducibility of AA, and the detection limit of hypochlorite and AA were 0.027 and 0.677 μM, respectively. The ratiometric colorimetric sensing platform offered higher sensitivity and better selectivity because of the specific hypochlorite-induced reaction and the excellent peroxidase-like activity of Fe(3)O(4)-MOF-5(Fe). The proposed novel strategy provided the guidance to develop sensors for successive detection of hypochlorite and AA in complicated samples.","pmid":"39322174","doi":"10.1016/j.ab.2024.115678","url":"https://pubmed.ncbi.nlm.nih.gov/39322174/"},{"id":356,"title":"Enhanced electrolytic production of hypochlorous acid using phosphorus-modified carbon felt electrodes: A study in disinfectant synthesis.","authors":"Ren, Shuoqi; Zhang, Qiwei; Yuan, Mu; Cui, Chongwei; Qiu, Shan; Deng, Fengxia","year":2024,"date":"2024 Oct","journal":"Chemosphere","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"In this study, we fabricated phosphorus-modified carbon felt electrode anodes for chloride oxidation in saline solutions to produce HClO via electrocatalysis, forming a compound fungicide saline applicable for debridement and disinfection. A low-cost phosphorus-modified carbon felt electrode (P@CF) with high chlorine evolution reaction activity was synthesized to address the reduced efficiency of CER and the solution's pH increase. Heteroatoms P and O were introduced into the carbon felt by phosphoric acid activation followed by heat treatment. The maximum active chlorine concentration on the P@CF electrode could reach 616.8 mg/L in 60 min under the optimal synthesis conditions of a phosphoric acid mass fraction of 30%, a phosphoric acid impregnation time of 3 h, and a heat treatment temperature of 300 °C. The active chlorine concentration was 1.8 times higher on the P@CF electrode compared to the original carbon felt electrode. The optimal reaction conditions for the generation of active chlorine were as follows: salt concentration of 9 g/L, voltage of 7 V, and electrode spacing of 2 cm as verified by response surfaces. This electrolysis reaction follows one-stage reaction kinetics. Subsequently, the disinfection efficacy of the produced disinfectants was examined. The prepared disinfectant was also compared to a commercially available hypochlorite disinfectant, showing similar disinfection effects on E. coli for both.","pmid":"39306113","doi":"10.1016/j.chemosphere.2024.143367","url":"https://pubmed.ncbi.nlm.nih.gov/39306113/"},{"id":366,"title":"HOCl-producing electrochemical bandage is active in murine polymicrobial wound infection.","authors":"Fleming, Derek; Bozyel, Ibrahim; Koscianski, Christina A; Ozdemir, Dilara; Karau, Melissa J; Cuello, Luz; Anoy, Md Monzurul Islam; Gelston, Suzanne; Schuetz, Audrey N; Greenwood-Quaintance, Kerryl E; Mandrekar, Jayawant N; Beyenal, Haluk; Patel, Robin","year":2024,"date":"2024 Oct 3","journal":"Microbiology spectrum","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Wound infections, exacerbated by the prevalence of antibiotic-resistant bacterial pathogens, necessitate innovative antimicrobial approaches. Polymicrobial infections, often involving Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), present challenges due to biofilm formation and antibiotic resistance. Hypochlorous acid (HOCl), a potent antimicrobial agent, holds promise as an alternative therapy. An electrochemical bandage (e-bandage) that generates HOCl in situ via precise polarization controlled by a miniaturized potentiostat was evaluated for the treatment of murine wound biofilm infections containing both P. aeruginosa with \"difficult-to-treat\" resistance and MRSA. Previously, HOCl-producing e-bandage was shown to reduce murine wound biofilms containing P. aeruginosa alone. Here, in 5-mm excisional skin wounds containing 48-h biofilms comprising MRSA and P. aeruginosa combined, polarized e-bandage treatment reduced MRSA by 1.1 log(10) CFU/g (P = 0.026) vs non-polarized e-bandage treatment (no HOCl production), and 1.4 log(10) CFU/g (0.0015) vs Tegaderm only controls; P. aeruginosa was similarly reduced by 1.6 log(10) CFU/g (P = 0.0032) and 1.6 log(10) CFU/g (P = 0.0015), respectively. For wounds infected with MRSA alone, polarized e-bandage treatment reduced bacterial load by 1.1 log(10) CFU/g (P = 0.0048) and 1.3 log(10) CFU/g (P = 0.0048) compared with non-polarized e-bandage and Tegaderm only, respectively. The e-bandage treatment did not negatively impact wound healing or cause tissue toxicity. The addition of systemic antibiotics did not enhance the antimicrobial efficacy of e-bandages. This study provides additional evidence for the HOCl-producing e-bandage as a novel antimicrobial strategy for managing wound infections, including in the context of antibiotic resistance and polymicrobial infections. IMPORTANCE: New approaches are needed to combat the rise of antimicrobial-resistant infections. The HOCl-producing electrochemical bandage (e-bandage) leverages in situ generation of HOCl, a natural biocide, for broad-spectrum killing of wound pathogens. Unlike traditional therapies that may exhibit limited activity against biofilms and antimicrobial-resistant organisms, the e-bandage offers a potent, standalone solution that does not contribute to further resistance or require adjunctive antibiotic therapy. Here, we show the ability of the e-bandage to address polymicrobial infection by antimicrobial resistant clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa, two commonly isolated, co-infecting wound pathogens. Effectiveness of the HOCl-producing e-bandage in reducing pathogen load while minimizing tissue toxicity and avoiding the need for systemic antibiotics underscores its potential as a tool in managing complex wound infections.","pmid":"39162542","doi":"10.1128/spectrum.00626-24","url":"https://pubmed.ncbi.nlm.nih.gov/39162542/"},{"id":368,"title":"AIE-based fluorescent probe designed with xanthone as a π-bridge for detecting of ClO(-) in pericarp and living cells.","authors":"Chao, Mingzhen; Zhang, Haitao; Hu, Qingfei; Ma, Shanghong; Cui, Xiubin; Yu, Xin","year":2025,"date":"2025 Jan 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The role of ClO(-) in the physiological functioning of organisms is significant. In this paper, the four fluorescent probes HON(x) (HON(1), HON(2), HON(3) and HON(4)) were prepared based on oxyanthracene through the introduction of different substituents, and their photophysical properties were investigated, among which the AIE effect of HON(1) was the most significant, and therefore the fluorescent \"turn-off\" ClO(-) probe HON(1)-CN was chosen to be prepared by constructing the ClO(-) recognition site hydrazone bond at HON(1). The ClO(-) recognises the hydrazone group in the probe HON(1)-CN, and when the hydrazone bond is broken, the aldehyde group is released, generating HON(1) with yellow fluorescence. The probe HON(1)-CN is highly selective and stable for the detection of ClO(-) with a detection limit of 0.48 μM and a more than 10-fold increase in fluorescence intensity when the fluorescence is 'switched on', and to a lesser extent, the probe is also very good for the detection of hypochlorite ClO(-) in the pericarp. Finally, HON(1)-CN has also been used to detect the presence of ClO(-) in HeLa cells and zebrafish.","pmid":"39154404","doi":"10.1016/j.saa.2024.124984","url":"https://pubmed.ncbi.nlm.nih.gov/39154404/"},{"id":372,"title":"Identifying initial transformation products during chlorination of the indole moiety and unveiling their formation mechanisms.","authors":"Huan, MengXue; Liu, Yong Dong; Zhong, Rugang","year":2024,"date":"2024 Sep 18","journal":"Environmental science. Processes & impacts","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"To identify toxicity drivers within poorly characterized high-molar-weight disinfection by-products (DBPs), relatively stable high-yield initial transformation products generated from aromatic amino acids and peptides and humic substances have drawn much attention. In this study, initial transformation products in chlorination of the indole moiety in tryptophan (Trp) are proposed and their formation mechanisms were investigated using a quantum chemical computational method. The results indicate that 3-Cl-Trp+ is initially formed after the Cl(+) of HOCl attacks the indole moiety, and nucleophilic addition with nucleophilic agents (H(2)O and OCl(-)) is thermodynamically preferred over deprotonation to generate 2-X-3-Cl-indoline moiety (X = OH and OCl), which is in contrast to indole. Over 25 types of initial transformation products are proposed from the 2-X-3-Cl-indoline moiety and two ring opening pathways were found at N1-C2 and C2-C3 bonds. Significantly, most structures of initial transformation products proposed based on experimental detection m/z values were confirmed using quantum chemical calculations and some new products are proposed in this work. The results are helpful to expand our understanding of the intrinsic reactivity of aromatic ring towards chlorination by hypochlorous acid.","pmid":"39132965","doi":"10.1039/d4em00196f","url":"https://pubmed.ncbi.nlm.nih.gov/39132965/"},{"id":374,"title":"A ratiometric fluorescent probe for selective detection of hypochlorite (ClO(-)) and gallium (III) (Ga(3+)) ions in environmental and food samples.","authors":"Pan, Yan; Liang, Zhongding; Li, Lin; Yan, Liqiang; Wu, Xiongzhi","year":2024,"date":"2024 Dec 15","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorite (ClO(-)) and gallium (Ⅲ) ions (Ga(3+)) have extensive applications in various human industries and daily activities. However, their inherent toxicity poses significant risks to environmental preservation and human well-being. Hence, the development of reliable and handy detection tools for ClO(-) and Ga(3+) in the environment and food is crucial. In this study, a ratiometric fluorescent probe was prepared based on benzothiazolaldehyde and pyridine-2-carboxylic acid hydrazide, which exhibited exceptional performance characteristics for the selective detection of ClO(-) and Ga(3+). These features include high specificity, low detection limits (0.28 μM for ClO(-), 0.13 μM for Ga(3+)), mild pH conditions (pH 4-11 for ClO(-), pH 6-11 for Ga(3+)), fast response time (within 30 s), as well as versatile applicability across different matrices such as water, soil, food, and plant samples. Additionally, this probe can be used with a smartphone color recognition app. The probe offers a convenient and effective tool for the detection of ClO(-) and Ga(3+), demonstrating its potential application value in environmental monitoring and food safety.","pmid":"39116591","doi":"10.1016/j.saa.2024.124927","url":"https://pubmed.ncbi.nlm.nih.gov/39116591/"},{"id":375,"title":"Probing the toxic hypochlorous acid in natural waters and biosystem by a coumarin-based fluorescence probe.","authors":"Ma, Junyan; Zhao, Mingtao; Kong, Xiangtao; Li, He; Xie, Hua; Yang, Xiaomei; Zhang, Zhenxing","year":2024,"date":"2024 Sep 1","journal":"Ecotoxicology and environmental safety","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"Since the onset of the SARS-CoV-2 pandemic in early 2020, there has been a notable rise in sodium hypochlorite disinfectants. Sodium hypochlorite undergoes hydrolysis to generate hypochlorous acid for virus eradication. This chlorine-based disinfectant is widely utilized for public disinfection due to its effectiveness. Although sodium hypochlorite disinfection is convenient, its excessive and indiscriminate use can harm the water environment and pose a risk to human health. Hypochlorous acid, a reactive oxygen species, plays a crucial role in the troposphere, stratospheric chemistry, and oxidizing capacity. Additionally, hypochlorous acid is vital as a reactive oxygen species in biological systems, and its irregular metabolism and level is associated with several illnesses. Thus, it is crucial to identify hypochlorous acid to comprehend its environmental and biological functions precisely. Here, we constructed a new fluorescent probe, utilizing the twisted intramolecular charge transfer mechanism to quickly and accurately detect hypochlorous acid in environmental water and biosystems. The probe showed a notable increase in fluorescence when exposed to hypochlorous acid, demonstrating its excellent selectivity, fast response time (less than 10 seconds), a large Stokes shift (∼ 102 nm), and a low detection limit of 15.5 nM.","pmid":"39097417","doi":"10.1016/j.ecoenv.2024.116836","url":"https://pubmed.ncbi.nlm.nih.gov/39097417/"},{"id":380,"title":"The effect of hypochlorous acid inhalation on the activity of antioxidant system enzymes in rats of different ages.","authors":"Murashevych, Bohdan; Maslak, Hanna; Girenko, Dmitry; Abraimova, Olha; Netronina, Olha; Shvets, Volodymyr","year":2024,"date":"2024 Aug-Sep","journal":"Free radical research","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"Hypochlorous acid HOCl is an effective disinfectant with a broad spectrum and high rate of microbicidal action. Its use for air treatment can be an effective tool for the prevention and therapy of infectious diseases. In this work, the in vivo study was conducted on 110 Wistar Han rats (12 and 72 weeks old) on the effect of a single inhalation of air containing gaseous HOCl on the activity of antioxidant system enzymes. For this, a special installation was designed to uniformly maintain the concentration of HOCl in the air and regulate it over a wide range. Inhalation exposure was carried out for 4 h at total chlorine concentrations in the air of approximately 2.0 mg/m(3) and 5.0 mg/m(3), after which the animals were observed for 14 days. The effect of inhalation on the antioxidant system activity varied significantly in animals of different ages. Catalase activity in young rats increased approximately 2-fold on days 1-2 after inhalation, regardless of the HOCl concentration, while in old animals a sharp dose-dependent decrease was initially observed. The glutathione peroxidase activity in animals of both ages increased upon inhalation of air with 5.0 mg/m(3) HOCl, and in old animals this was more pronounced; when the HOCl concentration decreased to 2.0 mg/m(3), this indicator increased slightly in old rats and remained virtually unchanged in young ones. The glutathione reductase activity when exposed to 2.0 mg/m(3) HOCl did not change for both age groups, and with increasing HOCl concentration it increased by 1.5-2.0 times in all animals.","pmid":"39073910","doi":"10.1080/10715762.2024.2386688","url":"https://pubmed.ncbi.nlm.nih.gov/39073910/"},{"id":381,"title":"A self-assembled nanoprobe for rapid detection of hypochlorite in pure water and its application in living cells, food and environmental systems.","authors":"Liang, Tianyu; Chen, Xinyu; Liu, Shuling; Li, Hanyang; Du, Tianli; Li, Yang; Tian, Mingyu; Wu, Chengyan; Sun, Xiaofei; Qiang, Taotao; Zhong, Keli; Tang, Lijun","year":2024,"date":"2024 Nov 1","journal":"Talanta","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"As an important ROS species participating in various physiological and pathological processes, high level of hypochlorite (ClO(-)) poses significant health and safety concerns, necessitating efficient detection methods. Herein, this study introduces a water-soluble fluorescent nanoprobe Nano-SJD, effectively detect ClO(-) in both food samples and living cells. The small molecular probe SJD with N, N-dimethylthiocarbamyl (DMTC) as recognition moiety was constructed based on a naphthalene derivative. To further improve the water solubility, SJD was assembled with an amphiphilic copolymer (mPEG-DSPE) to prepare a water soluble fluorescent nanoprobe Nano-SJD. Fortunately, the nanoprobe preserves the excellent properties of small molecules and performs very well optical response to ClO(-) in aqueous solution, possessing the advantages including ultra-rapid response (within 1 s), minimal interference, low detection limits (0.39 μM) and good pH stability. What's more important, we have also developed smartphone-compatible test paper strips for convenient on-site detection of ClO(-) in real-water samples. Additionally, the robust fluorescent imaging behavior of Nano-SJD for visualization of ClO(-) in living cells highlights its broad potential in biosystem applicability.","pmid":"39067201","doi":"10.1016/j.talanta.2024.126597","url":"https://pubmed.ncbi.nlm.nih.gov/39067201/"},{"id":386,"title":"[An in vitro experiment on the stability and irritant of hypochlorous acid in oral cavity].","authors":"Liu, Zhao-Chen; Sun, Pei; Pan, Ke-Qing; Wang, Pei-Yan; Zhang, Hui; Yuan, Chang-Qing; Deng, Jing","year":2024,"date":"2024 Apr","journal":"Shanghai kou qiang yi xue = Shanghai journal of stomatology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"PURPOSE: To study the stability of physicochemical properties and sterilizing effect about two commercially available hypochlorous acid (HClO) products under simulated clinical conditions, and to evaluate the compatibility of HClO on soft and hard tissues and cells in oral cavity. METHODS: Samples of HClO solution with different production processes were prepared, to detect the changes of physicochemical indexes of each sample over time under simulated clinical conditions (shielded from light at 20-25 ℃, open the cover for 5 minutes every day), including free available chlorine, oxidation-reduction potential and pH. Through suspension quantitative germicidal test, the antibiosis-concentration curve of HClO solution was made, so as to calibrate the change of antibacterial ability of disinfectant with the decrease of available chlorine content during storage. Pulp, tongue and dentine were immersed in PBS, 100 ppm HClO, 200 ppm HClO and 3% NaClO. The influence on soft and hard tissues was evaluated by weighing method and microhardness test. The toxic effects of HClO, NaClO and their 10-fold diluent on human gingival fibroblasts were determined by CCK-8 cytotoxicity assay. GraphPad PRIS 8.0 software was used to analyze the data. RESULTS: Under simulated conditions, the free available chlorine (FAC) of HClO solution decayed with time, and the attenuation degree was less than 20 ppm within 1 month. The bactericidal effect of each HClO sample was still higher than 5log after concentration decay. There was no obvious dissolution and destruction to soft and hard tissues for HClO(P＞0.05). The cell viability of HClO to human gingival fibroblast cells (HGFC) was greater than 80%, which was much higher than 3% NaClO (P＜0.001). CONCLUSIONS: The bactericidal effect and stability of HClO solution can meet clinical needs, which has low cytotoxicity and good histocompatibility. It is expected to become a safe and efficient disinfection product in the field of living pulp preservation and dental pulp regeneration.","pmid":"39005089","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/39005089/"},{"id":401,"title":"Correlation between disinfection efficacy and cumulative amount of free chlorine reaching various positions during ultrasonic fogging with hypochlorite solution.","authors":"Fukuzaki, Satoshi; Hotta, Hajime; Nojima, Shun","year":2024,"date":"2024","journal":"Journal of microorganism control","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"When a hypochlorite solution is ultrasonically fogged in a room, free chlorine, i.e., HOCl and OCl(-), reaches various positions in two forms: fine fog droplets and gaseous hypochlorous acid（HOCl((g))）. In this study, the cumulative amount of free chlorine reaching various positions on the floor away from the fogger was measured in a 90-m(3) room, using a sulfamate-carrying glass-fiber filter indicator. The fine droplets were blown out from the fogger into the spaces at different discharge port angles of 30 - 90°. Free chlorine was successfully trapped by sulfamate, forming monochlorosulfamate, which was stably retained on the indicator. The cumulative amount of free chlorine（ ng/indicator） increased with fogging time at each position and depended on the blow angle and distance from the fogger. Minor differences in the HOCl((g)) concentration near the floor at all positions were observed. The disinfection efficacy of the fogging treatment against Staphylococcus aureus on wet surfaces was relatively higher at positions near the fogger and lower at positions far from the fogger. At each discharge port angle, a strong correlation between the logarithmic reduction in relative viable cells and the cumulative amount of free chlorine reaching S. aureus plates was observed. The slopes of the regression lines of correlation diagrams as a function of the cumulative amount of free chlorine were between -0.0362 and -0.0413 ng(-1). This study demonstrated that the cumulative amount of free chlorine measured using the filter indicator could reflect the sum of the free chlorine of both fine droplets and HOCl((g)), and that the disinfection efficiency depended on the cumulative amount of free chlorine reaching different areas.","pmid":"38880619","doi":"10.4265/jmc.29.2_75","url":"https://pubmed.ncbi.nlm.nih.gov/38880619/"},{"id":405,"title":"The efficient application of instilling negative pressure wound therapy with a hypochlorous acid-preserved wound cleanser: a case series and practical advice.","authors":"Matthews, Marc R; Fernández, Luis G; Hermans, Michel He; Chakravarthy, Debashish","year":2024,"date":"2024 May","journal":"Wounds : a compendium of clinical research and practice","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"BACKGROUND: The use of negative pressure wound therapy with instillation and dwell time (NPWTi-d) has been shown to be effective in removing nonviable tissue, reducing bioburden, and promoting granulation tissue formation in acute and chronic infected wounds. OBJECTIVE: To illustrate the clinical efficacy of the use of pure hypochlorous acid (pHA) antimicrobially preserved wound cleansing solution as the instillation fluid for NPWTi-d (NPWTi-d/pHA) in wound bed preparation in patients with complex wounds. CASE REPORT: The treatment protocol for use of NPWTi-d/pHA in preparing wound beds for final closure is demonstrated in 3 illustrative cases of patients with complex wounds resulting from necrotizing infection and trauma with heavy contamination. All 3 patients developed a healthy-appearing wound bed deemed suitable for primary closure an average of approximately 1 month following initial surgical debridement. CONCLUSION: The cases presented demonstrate the ability of a pHA antimicrobially preserved wound cleansing solution used as the instillation fluid with NPWTi-d to aid in bacterial reduction, mechanical debridement, and promotion of wound healing. Use of NPWTi-d/pHA in these cases of extensive necrotizing infection and posttraumatic injury with heavy contamination allowed for final closure an average of 1 month after initial surgical debridement.","pmid":"38861209","doi":"10.25270/wnds/21122","url":"https://pubmed.ncbi.nlm.nih.gov/38861209/"},{"id":411,"title":"The HOCl dry fog-is it safe for human cells?","authors":"Lewandowski, Rafał Bogdan; Stępińska, Małgorzata; Osuchowski, Łukasz; Kasprzycka, Wiktoria; Dobrzyńska, Monika; Mierczyk, Zygmunt; Trafny, Elżbieta Anna","year":2024,"date":"2024","journal":"PloS one","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"This study aims to investigate if high-concentration HOCl fogging disinfection causes cytotoxicity and genotoxicity to cultured primary human skin fibroblasts. The cells were exposed to a dry fog of HOCl produced from solutions with a concentration of 300 ppm (5.72 mM) or 500 ppm (9.53 mM). After four times when fibroblasts were exposed to aerosolized HOCl at a concentration of 500 ppm for 9 minutes, significant cytotoxicity and genotoxicity effects were observed. Significant changes in the morphology of fibroblasts and cell death due to membrane disruption were observed, independent of the number of exposures. Flow cytometry analyses performed under these experimental conditions indicated a decrease in the number of cells with an intact cell membrane in the exposed samples compared to the sham samples, dropping to 49.1% of the total cells. Additionally, under the same conditions, the neutral comet assay results demonstrated significant DNA damage in the exposed cells. However, no analogous damages were found when the cells were exposed to aerosolized HOCl generated from a 300-ppm solution for 3 minutes, whether once or four times. Therefore, we have concluded that aerosolized HOCl in dry fog, with a concentration exceeding 300 ppm, can cause cytotoxic and genotoxic effects on human skin fibroblasts.","pmid":"38809935","doi":"10.1371/journal.pone.0304602","url":"https://pubmed.ncbi.nlm.nih.gov/38809935/"},{"id":413,"title":"A First-in-Human Randomized Clinical Study Investigating the Safety and Tolerability of Stabilized Hypochlorous Acid in Patients with Chronic Leg Ulcers.","authors":"Fazli, Magnus Mustafa; Kirketerp-Møller, Klaus; Sonne, David Peick; Balchen, Torben; Gundersen, Glenn; Jørgensen, Elin; Bjarnsholt, Thomas","year":2024,"date":"2024 Nov","journal":"Advances in wound care","category":"Water, sanitation & biosecurity","evidence":"Randomized controlled trial","relevance":"High","abstract":"Objective: Biofilm infections in chronic wounds are common and pose a significant clinical challenge. This challenge was addressed by developing the SoftOx Biofilm Eradicator (SBE) composed of hypochlorous acid (HOCl) and acetic acid with strong broad-spectrum antimicrobial activity. Approach: First-in-human study investigating the safety and tolerability as primary endpoints and wound size effect and antimicrobial efficacy as secondary endpoints of SBE treatment in chronic leg wound patients. The study was divided into two as follows: a randomized, double-blinded, Single Ascending Dose (SAD) phase (n = 16 SBE; n = 4 placebo), where patients were treated with SBE or saline (placebo) only once, followed by an open-label, Multiple Ascending Dose (MAD) phase (n = 8), where patients were treated with SBE once daily or twice daily over five days. Reporting is according to CONSORT guidelines. Results: SBE was safe and well-tolerated in chronic leg wound patients. There were no significant differences in pain during and after treatment with SBE or the placebo. The SBE treatment reduced bioburden in wounds compared to baseline, with 98% and 49% median reduction after SBE or placebo treatment, respectively. A dose-dependent trend in absolute wound size reduction was observed in the MAD groups with a median (min, max) change of -2.99 (-14.25, -1.5) cm(2) in the once-daily and -10.48 (-17.95, -0.38) cm(2) in the twice-daily group, respectively. Innovation and Conclusion: This study demonstrated the safe use of HOCl-based SBE in chronic leg wounds with promising trends of immediate antimicrobial action and beneficial effect on wound healing.","pmid":"38780759","doi":"10.1089/wound.2024.0040","url":"https://pubmed.ncbi.nlm.nih.gov/38780759/"},{"id":414,"title":"Evaluation of treatment of methicillin-resistant Staphylococcus aureus biofilms with intermittent electrochemically generated H(2)O(2) or HOCl.","authors":"Anoy, Md Monzurul Islam; Kim, Won-Jun; Gelston, Suzanne; Fleming, Derek; Patel, Robin; Beyenal, Haluk","year":2024,"date":"2024 Jul 9","journal":"Antimicrobial agents and chemotherapy","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Chronic wound infections can be difficult to treat and may lead to impaired healing and worsened patient outcomes. Novel treatment strategies are needed. This study evaluated the effects of intermittently produced hydrogen peroxide (H(2)O(2)) and hypochlorous acid (HOCl), generated via an electrochemical bandage (e-bandage), against methicillin-resistant Staphylococcus aureus biofilms in an agar membrane biofilm model. By changing the working electrode potential, the e-bandage generated either HOCl (1.5 V(Ag/AgCl)) or H(2)O(2) (-0.6 V(Ag/AgCl)). The degree of biocidal activity of intermittent treatment with HOCl and H(2)O(2) correlated with HOCl treatment time; HOCl treatment durations of 0, 1.5, 3, 4.5, and 6 hours (with the rest of the 6-hour total treatment time devoted to H(2)O(2) generation) resulted in mean biofilm reductions of 1.36 ± 0.2, 2.22 ± 0.16, 3.46 ± 0.38, 4.63 ± 0.74, and 7.66 ± 0.5 log CFU/cm(2), respectively, vs. non-polarized controls, respectively. However, application of H(2)O(2) immediately after HOCl treatment was detrimental to biofilm removal. For example, 3 hours HOCl treatment followed by 3 hours H(2)O(2) resulted in a 1.90 ± 0.84 log CFU/cm(2) lower mean biofilm reduction than 3 hours HOCl treatment followed by 3 hours non-polarization. HOCl generated over 3 hours exhibited biocidal activity for at least 7.5 hours after e-bandage operation ceased; 3 hours of HOCl generation followed by 7.5 hours of non-polarization resulted in a biofilm cell reduction of 7.92 ± 0.12 log CFU/cm(2) vs. non-polarized controls. Finally, intermittent treatment with HOCl (i.e., interspersed with periods of e-bandage non-polarization) for various intervals showed similar effects (approximately 6 log CFU/cm(2) reduction vs. non-polarized control) to continuous treatment with HOCl for 3 hours, followed by 3 hours of non-polarization. These findings suggest that timing and sequencing of HOCl and H(2)O(2) treatments are crucial for maximizing biofilm control when using an e-bandage strategy.","pmid":"38771032","doi":"10.1128/aac.01722-23","url":"https://pubmed.ncbi.nlm.nih.gov/38771032/"},{"id":417,"title":"Multidisciplinary expert consensus statements and recommendations for use of hypochlorous acid as a solution for negative pressure wound therapy with instillation.","authors":"Kim, Paul J; Fernandez, Luis; Obst, Mary Ann; Chaffin, Abigail; Faust, Elizabeth; Lantis, John; Couch, Kara; Desvigne, Michael; Suski, Mark; Kundu, Neilendu; Matthews, Marc; Simman, Richard; Murphy, Christine; Nierenberg, Natalie E; Téot, Luc","year":2024,"date":"2024 Apr","journal":"Wounds : a compendium of clinical research and practice","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: HOCl (eg, pHAp) preserved solutions have antimicrobial properties and are considered safe and effective for wound management. NPWTi-d (or NPWTi) is an established adjunctive wound modality for a variety of wound etiologies in various anatomic locations in which an instillate solution dwells on the surface of the wound to assist in wound bed preparation. A variety of solutions have been used, including 0.9% normal saline wound cleansers and antiseptics. pHAp is growing in popularity as the solution of choice for NPWTi-d. OBJECTIVE: To evaluate consensus statements on the use of NPWTi-d with pHAp. METHODS: A 15-member multidisciplinary panel of expert clinicians in the United States, Canada, and France convened in person in April 2023 in Washington, D.C. and/or corresponded later to discuss 10 statements on the use of pHAp with NPWTi-d. The panelists then replied \"agree\" or \"disagree\" to each statement and had the option to provide comments. RESULTS: Ten consensus statements are presented, along with the proportion of agreement or disagreement and summary comments. Although agreement with the statements on NPWTi-d with pHAp varied, the statements appear to reflect individual preferences for use rather than concerns about safety or efficacy. CONCLUSION: The consensus indicates that NPWTi-d with pHAp can have a beneficial effect in wound care.","pmid":"38743855","doi":"10.25270/wnds/23143","url":"https://pubmed.ncbi.nlm.nih.gov/38743855/"},{"id":418,"title":"Assessing the stability and sporicidal efficacy of oxidizing disinfectants.","authors":"Brown, L; Marshall, A; Conway, L; Otter, J; Norville, P; Clarke, J","year":2024,"date":"2024 Jul","journal":"The Journal of hospital infection","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: The role of the healthcare environment in the transmission of clinical pathogens is well established. EN 17126:2018 was developed to address the need for regulated sporicidal product testing and includes a realistic medical soil to enable validation of products that claim combined cleaning and disinfection efficacy. AIM: To investigate the chemical stability and sporicidal efficacy of oxidizing disinfectant products in the presence of simulated clean and medical dirty conditions. METHODS: Disinfectant stability and sporicidal efficacy were evaluated in like-for-like ratios of soil:product. Disinfectants were exposed to simulated test soils and free chlorine, chlorine dioxide or peracetic acid concentrations were measured using standard colorimetric methods. Efficacy of disinfectants against C. difficile R027 endospores was assessed as per EN 17126:2018. Comparisons of performance between clean and medical dirty conditions were performed using one-way analysis of variance. Correlation analysis was performed using Pearson product-moment correlation. FINDINGS: Performance of chlorine-releasing agents (sodium dichloroisocyanurate, chlorine dioxide and hypochlorous acid) was concentration dependent, with 1000 ppm chlorine showing reduced stability and efficacy in dirty conditions. By contrast, peracetic acid product demonstrated stability and consistently achieved efficacy in dirty conditions. CONCLUSION: These results have implications for clinical practice, as ineffective environmental decontamination may increase the risk of transmission of pathogens that can cause healthcare-associated infections.","pmid":"38705474","doi":"10.1016/j.jhin.2024.04.010","url":"https://pubmed.ncbi.nlm.nih.gov/38705474/"},{"id":420,"title":"Antimicrobial action, cytotoxicity and erosive potential of hypochlorous acid obtained from an electrolytic device compared with sodium hypochlorite.","authors":"Souza, Matheus Albino; Steier, Liviu; Vanin, Gabriele Nichetti; Zanella, Mylena Lazareti; Pizzi, Camila Monteiro; Ferreira, Eduarda Rizzon; Dallepiane, Felipe Gomes; Piccolo, Nathan Mateus; da Silva Koch, Jordana; Souza, Kellyn Rocca; Costa, Ubirajara Maciel da; Dos Santos, Vanessa Valgas; Palatynska-Ulatowska, Aleksandra; de Figueiredo, José Antônio Poli","year":2024,"date":"2024 Apr 29","journal":"Clinical oral investigations","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVES: This study aimed to compare the antimicrobial action, cytotoxicity, cleaning ability, and erosion of dentine of hypochlorous acid (HClO) obtained from an electrolytic device at two different concentrations (Dentaqua) and three concentrations of sodium hypochlorite (NaOCl). METHODS: Microbiological test-The root canals of sixty single-rooted extracted human teeth were inoculated with Enterococcus faecalis and divided into 6 groups (n = 10), according to decontamination protocol: DW (control); 1% NaOCl; 2.5% NaOCl; 5.25% NaOCl; 250 ppm HClO and 500 ppm HClO. The colony-forming units were counted to evaluate the decontamination potential of each group, calculating the reduction in bacterial percentage. Cytotoxicity test-Cytotoxicity was evaluated after inoculation of the same tested protocols in fibroblastic cells for 3 min, calculating the cell viability percentages. Specifical statistical analysis was performed (α = 5%). Cleaning ability and erosion-Fifty-six single-rooted bovine lower incisors were divided into seven groups of 8 roots each, being the test groups 1% NaOCl; 2.5% NaOCl; 5,25% NaOCl; 250 ppm HClO and 500 ppm HClO, and a negative and positive control. Negative control was not contaminated, and the other groups were inoculated with Enterococcus faecalis. SEM images were ranked as from the cleanest to the least clean. Erosion was also assessed, being ranked from the least to the most eroded dentine. RESULTS: The highest bacterial reduction was observed in experimental groups, with no statistical differences between them (p > 0.05). The highest number of viable cells was observed in control group, followed by 250 ppm HClO and 500 ppm HClO groups, with statistical differences between them (p < 0.05). 1% NaOCl; 2.5% NaOCl; 5.25% NaOCl and 500 ppm HClO displayed the cleanest areas. All sodium hypochlorite groups displayed erosion with higher ranks with greater concentration, while hypochlorous acid did not display any erosion regardless the concentration. CONCLUSIONS: It is possible to conclude that HClO obtained from an electrolytic device presented high antimicrobial activity and low cytotoxicity in both tested concentrations. 500 ppm HClO did not display erosion and showed great cleaning ability. CLINICAL RELEVANCE: The use of 500 ppm hypochlorous acid may reduce unfavorable behavior of sodium hypochlorite whilst maintaining its antimicrobial action.","pmid":"38683234","doi":"10.1007/s00784-024-05675-6","url":"https://pubmed.ncbi.nlm.nih.gov/38683234/"},{"id":421,"title":"Antibacterial efficacy of silver nanoparticles, sodium hypochlorite, chlorhexidine, and hypochlorous acid on dentinal surfaces infected with Enterococcus faecalis.","authors":"Oncu, Aysenur; Celikten, Berkan; Aydın, Betül; Amasya, Gulin; Tuncay, Erkan; Eskiler, Gamze Guney; Açık, Leyla; Sevimay, Fatma Semra","year":2024,"date":"2024 Sep","journal":"Microscopy research and technique","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The purpose of this study was to evaluate the antibacterial effect of silver nanoparticles (AgNPs) against Enterococcus faecalis and compare it with different irrigation solutions. This study was performed using 64 dentin blocks. E. faecalis suspension was dispensed to each sample and incubated under anaerobic conditions at 37°C throughout 21 days. After the inoculation period, the following solutions were added to each group and kept for 5 min: Group 1, 5.25% sodium hypochlorite (NaOCl); Group 2, 2.5% NaOCl; Group 3, 1% NaOCl; Group 4, 2% chlorhexidine (CHX); Group 5, 200 ppm hypochlorous acid (HOCl); and Group 6, AgNPs. The samples of positive control were treated with sterile saline. Biofilm viability assay was performed using the LIVE/DEAD BacLight Bacterial Viability Kit. Samples were examined using confocal laser scanning microscopy, respectively. There was no significant difference between the 5.25% NaOCl, 2.5% NaOCl, and 1%NaOCl groups (p > .05). However, these groups showed statistically higher antibacterial activity than the 2% CHX, 200 ppm HOCl, and AgNP groups. Also, 2% CHX showed greater percentage of dead cells compared with the AgNP and HOCl groups. While AgNPs group showed lower dead cell rate than all NaOCl groups and 2% CHX, it caused higher dead cells than 200 ppm HOCl group. The 200 ppm HOCl group showed the lowest percentage of dead cells (p < .05) Although the antibacterial effect of AgNPs is not as high as NaOCl and CHX, it has considerable bactericidal activity against E. faecalis and can be improved by further studies. RESEARCH HIGHLIGHTS: New antimicrobial approaches for root canal irrigation. Antimicrobial effect of silver nanoparticles against E. faecalis. Elimination of the biofilm layer for the success of endodontic treatment.","pmid":"38683025","doi":"10.1002/jemt.24590","url":"https://pubmed.ncbi.nlm.nih.gov/38683025/"},{"id":424,"title":"Elevated levels of iodide promote peroxidase-mediated protein iodination and inhibit protein chlorination.","authors":"Jokumsen, Kathrine V; Huhle, Valerie H; Hägglund, Per M; Davies, Michael J; Gamon, Luke F","year":2024,"date":"2024 Aug 1","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"At inflammatory sites, immune cells generate oxidants including H₂O₂. Myeloperoxidase (MPO), released by activated leukocytes employs H₂O₂ and halide/pseudohalides to form hypohalous acids that mediate pathogen killing. Hypochlorous acid (HOCl) is a major species formed. Excessive or misplaced HOCl formation damages host tissues with this linked to multiple inflammatory diseases. Previously (Redox Biology, 2020, 28, 101331) we reported that iodide (I⁻) modulates MPO-mediated protein damage by decreasing HOCl generation with concomitant hypoiodous acid (HOI) formation. HOI may however impact on protein structure, so in this study we examined whether and how HOI, from peroxidase/H₂O₂/I⁻ systems ± Cl⁻, modifies proteins. Experiments employed MPO and lactoperoxidase (LPO) and multiple proteins (serum albumins, anastellin), with both chemical (intact protein and peptide mass mapping, LC-MS) and structural (SDS-PAGE) changes assessed. LC-MS analyses revealed dose-dependent iodination of anastellin and albumins by LPO/H(2)O(2) with increasing I⁻. Incubation of BSA with MPO/H(2)O(2)/Cl⁻ revealed modest chlorination (Tyr286, Tyr475, ∼4 %) and Met modification. Lower levels of these species, and extensive iodination at specific Tyr and His residues (>20 % modification with ≥10 μM I⁻) were detected with increasing I⁻. Anastellin dimerization was inhibited by increasing I⁻, but less marked changes were observed with albumins. These data confirm that I⁻ competes with Cl⁻ for MPO and is an efficient HOCl scavenger. These processes decrease protein chlorination and oxidation, but result in extensive iodination. This is consistent with published data on the presence of iodinated Tyr on neutrophil proteins. The biological implications of protein iodination relative to chlorination require further clarification.","pmid":"38663830","doi":"10.1016/j.freeradbiomed.2024.04.230","url":"https://pubmed.ncbi.nlm.nih.gov/38663830/"},{"id":426,"title":"Antimicrobial action and cytotoxicity of hypochlorous acid obtained from an innovative electrolytic device - An in vitro study.","authors":"Souza, Matheus Albino; Zanella, Mylena Lazareti; Vanin, Gabriele Nichetti; Dallepiane, Felipe Gomes; Pizzi, Camila Yasmin Monteiro; Ferreira, Eduarda Rizzon; Fuhr, Marciele Cristiane Spanenberg; Piccolo, Nathan Mateus; Palhano, Huriel Scartazzini; da Silva Koch, Jordana; Souza, Kellyn Rocca; da Costa, Ubirajara Maciel; Dos Santos, Vanessa Valgas; Steier, Liviu; Bertol, Charise Dallazem; Figueiredo, José Antônio Poli de","year":2024,"date":"2024 Jul","journal":"Archives of oral biology","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"OBJECTIVE: This study evaluated the antimicrobial effect and cytotoxicity of hypochlorous acid(HClO) obtained from an innovative electrolytic device. DESIGN: The root canals of fifty extracted human teeth were inoculated with Enterococcus faecalis and divided into 5 groups (n = 10): DW (control); 2% chlorhexidine gel(CHX); 2.5% sodium hypochlorite(NaOCl); 250 ppm HClO and 500 ppm HClO. The counting of colony forming units evaluated the decontamination potential of each group. Cytotoxicity was evaluated after inoculation of tested protocols in fibroblastic cells for 3 min, calculating the cell viability. Specific statistical analysis was performed (α = 5%). RESULTS: The highest bacterial reduction was observed in experimental groups, with no statistical differences from each other (p > 0.05). The highest number of viable cells was observed in control group, followed by 250 ppm HClO and 500 ppm HClO groups, with statistical differences from each other (p < 0.05). CONCLUSIONS: It could be concluded that HClO presented high antimicrobial activity and low cytotoxicity at both tested concentrations.","pmid":"38657440","doi":"10.1016/j.archoralbio.2024.105966","url":"https://pubmed.ncbi.nlm.nih.gov/38657440/"},{"id":430,"title":"Taming Janus-Faced Quinoline-Derived Fluorescent Probes for Dual-Channel Distinguishable Visualization of HSO(3)(-) and HClO in Dried Foods and Living Cells.","authors":"Xu, Zi Yi; Wang, Rong; Xiao, Qi; Luo, Hong Qun; Li, Nian Bing","year":2024,"date":"2024 May 1","journal":"Journal of agricultural and food chemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"With the booming development of food manufacturing, developing ideal analytical tools to precisely quantify food additives is highly sought after in the food science field. Herein, a new series of quinoline-derived multifunctional fluorescent probes has been synthesized. Bearing double reactive sites, these compounds display fluorescence response toward both bisulfite (HSO(3)(-)) and hypochlorous acid (HClO). Among these compact structures, compound ethyl-2-cyano-3-(6-(methylthio)quinolin-2-yl)acrylate (QTE) was screened out. Probe QTE not only shows ratiometric variation toward HSO(3)(-) with little cross talk but also performs turn-off signal toward HClO. In addition, probe QTE has been utilized for bioimaging of HClO in living cells. Furthermore, the HSO(3)(-) content in dried food samples has been appraised by QTE with satisfactory results. Meanwhile, relying on the apparent chromaticity change, a flexible dark-box device has been elaborated for chromatic analysis, promoting visualization of HSO(3)(-) in the field.","pmid":"38630689","doi":"10.1021/acs.jafc.4c00375","url":"https://pubmed.ncbi.nlm.nih.gov/38630689/"},{"id":431,"title":"The therapeutic potential of thiocyanate and hypothiocyanous acid against pulmonary infections.","authors":"Ashtiwi, Nuha Milad; Kim, Susan O; Chandler, Joshua D; Rada, Balázs","year":2024,"date":"2024 Jul","journal":"Free radical biology & medicine","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"Hypothiocyanous acid (HOSCN) is an endogenous oxidant produced by peroxidase oxidation of thiocyanate (SCN(-)), an ubiquitous sulfur-containing pseudohalide synthesized from cyanide. HOSCN serves as a potent microbicidal agent against pathogenic bacteria, viruses, and fungi, functioning through thiol-targeting mechanisms, independent of currently approved antimicrobials. Additionally, SCN(-) reacts with hypochlorous acid (HOCl), a highly reactive oxidant produced by myeloperoxidase (MPO) at sites of inflammation, also producing HOSCN. This imparts both antioxidant and antimicrobial potential to SCN(-). In this review, we discuss roles of HOSCN/SCN(-) in immunity and potential therapeutic implications for combating infections.","pmid":"38608822","doi":"10.1016/j.freeradbiomed.2024.04.217","url":"https://pubmed.ncbi.nlm.nih.gov/38608822/"},{"id":432,"title":"Hemicyanine-Phenothiazine Based Highly Selective Ratiometric Fluorescent Probes for Detecting Hypochlorite Ion in Fruits, Vegetables and Beverages.","authors":"Zhang, Jinyang; Wang, Zhe; Zhang, Rui; Lei, Xueli; Wang, Guangtu; Zou, Ping","year":2025,"date":"2025 Apr","journal":"Journal of fluorescence","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Hypochloric acid (HClO) is a reactive oxygen species (ROS) that functions as a bacteriostatic and disinfectant in food production. Excessive levels of ClO(-), however, have been linked to various health issues, including cardiovascular diseases (Halliwell and Gutteridge in Oxford University press, USA, 2015), arthritis, and neurodegenerative diseases (Heinzelmann and Bauer in Biol Chem. 391(6):675-693, 2010). Therefore, synthesizing highly selective and sensitive probes for rapidly detecting endogenous ClO(-) in daily foods is currently a popular research topic (Kalyanaraman et al. in Redox Biol. 15:347-362, 2018; Winterbourn in Nat Chem Biol. 4(5):278-286, 2008; Turrens in J Physiol. 552(2):335-344, 2003). Thus, we have developed two highly selective ratiometric fluorescent probes (Probe1 and Probe2) based on indole-phenothiazine to detect ClO(-) in common vegetables, fruits and beverages qualitatively and quantitatively. Moreover, Both Probe1 and Probe2 have shown good specificity and stability, with high fluorescence intensity and long duration (Feng et al. in Adv Sci. 5:1800397, 2018; Wei et al. in Angew Chem. 131(14):4595-4599, 2019; Baruah et al. in J Mater Chem B, 2022).","pmid":"38607530","doi":"10.1007/s10895-024-03694-w","url":"https://pubmed.ncbi.nlm.nih.gov/38607530/"},{"id":434,"title":"Hypochlorous acid-the future of wound care?","authors":"Roshan, Muhammad; Tariq, Maryam; Akhtar, Muhammad Sulaman","year":2024,"date":"2024 Mar","journal":"JPMA. The Journal of the Pakistan Medical Association","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"","pmid":"38591320","doi":"10.47391/JPMA.10290","url":"https://pubmed.ncbi.nlm.nih.gov/38591320/"},{"id":437,"title":"Detection and application of hypochlorous acid in both aqueous environments and living organisms.","authors":"Zhang, Qian; Zhang, Di; Zhu, Zeyu; Jiang, Yuliang","year":2024,"date":"2024 Jun 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The scarcity of water resources has raised concerns regarding drinking water safety. Excessive addition of hypochlorous acid (OCl(-)) as a disinfectant in drinking water can result in severe consequences. Moreover, abnormal levels of OCl(-) within the human body can lead to various diseases. Employing fluorescence analysis, the design and synthesis of specific fluorescent probes for simultaneous detection of OCl(-) in water environments and living organisms holds strategic significance in ensuring the safety of drinking water and mitigating potential risks caused by its abnormal concentrations. This article utilizes naphthalimide as a precursor to develop a novel probe enabling highly sensitive detection of OCl(-) in water environments and at the organelle level within living organisms. This endeavor serves to provide assurance for drinking water safety and offers health alerts.","pmid":"38581774","doi":"10.1016/j.saa.2024.124225","url":"https://pubmed.ncbi.nlm.nih.gov/38581774/"},{"id":442,"title":"Virucidal efficacy of hypochlorous acid water for aqueous phase and atomization against SARS-CoV-2.","authors":"Kubo, Makoto; Eda, Ryotaro; Maehana, Shotaro; Fuketa, Hiroshi; Shinkai, Norihiro; Kawamura, Naohisa; Kitasato, Hidero; Hanaki, Hideaki","year":2024,"date":"2024 Mar","journal":"Journal of water and health","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Coronavirus disease 2019 (COVID-19) is an infectious viral disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that emerged at the end of 2019. SARS-CoV-2 can be transmitted through droplets, aerosols, and fomites. Disinfectants such as alcohol, quaternary ammonium salts, and chlorine-releasing agents, including hypochlorous acid, are used to prevent the spread of SARS-CoV-2 infection. In the present study, we investigated the efficacy of ionless hypochlorous acid water (HOCl) in suspension and by spraying to inactivate SARS-CoV-2. The virucidal efficacy of HOCl solution in tests against SARS-CoV-2 was evaluated as 50% tissue culture infectious dose. Although the presence of organic compounds influenced the virucidal efficacy, HOCl treatment for 20 s was significantly effective to inactivate Wuhan and Delta strains in the suspension test. HOCl atomization for several hours significantly reduced the SARS-CoV-2 attached to plastic plates. These results indicate that HOCl solution with elimination containing NaCl and other ions may have high virucidal efficacy against SARS-CoV-2. This study provides important information about the virucidal efficacy and use of HOCl solution.","pmid":"38557574","doi":"10.2166/wh.2024.348","url":"https://pubmed.ncbi.nlm.nih.gov/38557574/"},{"id":443,"title":"Dual-Channel/Localization Single-Molecule Fluorescence Probe for Monitoring ATP and HOCl in Early Diagnosis and Therapy of Rheumatoid Arthritis.","authors":"Qu, Wangbo; Tian, Ruowei; Yang, Bin; Guo, Taiyu; Wu, Zhou; Li, Yong; Geng, Zhirong; Wang, Zhilin","year":2024,"date":"2024 Apr 9","journal":"Analytical chemistry","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Rheumatoid arthritis (RA), a common chronic inflammatory illness, is still incurable, reducing the sufferers' quality of life significantly. Adenosine 5'-triphosphate (ATP) and hypochlorous acid (HOCl) are key indicators in RA, but their precise mechanisms in RA pathophysiology are unknown. As a result, in order to detect ATP and HOCl simultaneously, we created two new dual-channel/localization single-molecule fluorescence probes, RhTNMB and RhFNMB. Furthermore, RhFNMB outperformed RhTNMB in terms of detection performance. ATP and HOCl produce independent fluorescence responses in the light red channel (λ(ex) = 520 nm, λ(em) = 586 nm) and deep red channel (λ(ex) = 620 nm, λ(em) = 688 nm), respectively, without spectral crosstalk. It should be noted that the probe RhFNMB successfully imaged ATP in mitochondria and HOCl in cells. Surprisingly, the probe RhFNMB demonstrated remarkable detection ability in the diagnosis and treatment of Pseudomonas aeruginosa-induced abdominal inflammation in mice. We continued to apply the probe RhFNMB to track ATP and HOCl in RA and discovered that ATP and HOCl concentrations were considerably greater in RA joints than in normal joints. We also confirmed the therapeutic effect of methotrexate on RA. This study is the first to achieve dual-channel imaging of ATP and HOCl, which is of great value for the early diagnosis and therapy of RA.","pmid":"38551643","doi":"10.1021/acs.analchem.3c05342","url":"https://pubmed.ncbi.nlm.nih.gov/38551643/"},{"id":444,"title":"Anti-biofilm effectiveness of protocols for cleaning complete dentures in hospitalized patients: a randomized controlled trial.","authors":"Gomes, Anna Clara Gurgel; Maciel, Janaina Gomes; Garcia, Amanda Aparecida Maia Neves; Coelho, Letycia Accioly Simões; Rodrigues, Giulia Murcia; Porto, Vinicius Carvalho; Polyzois, Grigorios; Klein, Marlise Inêz; Soares, Simone; Urban, Vanessa Migliorini; Neppelenbroek, Karin Hermana","year":2024,"date":"2024","journal":"Journal of applied oral science : revista FOB","category":"Water, sanitation & biosecurity","evidence":"Randomized controlled trial","relevance":"High","abstract":"BACKGROUND: Denture biofilm acts as a potential reservoir for respiratory pathogens, considerably increasing the risk of lung infections, specifically aspiration pneumonia, mainly 48h after hospital admission. The establishment of a straightforward, affordable, and applicable hygiene protocol in a hospital environment for the effective control of denture biofilm can be particularly useful to prevent respiratory infections or reduce the course of established lung disease. OBJECTIVES: To evaluate the anti-biofilm effectiveness of denture cleaning protocols in hospitalized patients. METHODOLOGY: The maxillary complete dentures (MCDs) of 340 hospitalized participants were randomly cleaned once using one of the following 17 protocols (n=20): brushing with distilled water, toothpaste, or neutral liquid soap (controls); immersion in chemical solutions (1% sodium hypochlorite, alkaline peroxide, 0.12% or 2% chlorhexidine digluconate), or microwave irradiation (650 W for 3 min) combined or not with brushing. Before and after the application of the protocols, the biofilm of the intaglio surface of the MCDs was evaluated using two methods: denture biofilm coverage area (%) and microbiological quantitative cultures on blood agar and Sabouraud Dextrose Agar (CFU/mL). Data were subjected to the Wilcoxon and Kruskal-Wallis tests (α=0.05). RESULTS: All 17 protocols significantly reduced the percentage area of denture biofilm and microbial and fungal load (P<0.05). The highest percentage reductions in the area of denture biofilm were observed for 1% hypochlorite solution with or without brushing and for 2% chlorhexidine solution and microwave irradiation only in association with brushing (P<0.05). The greatest reductions in microbial and fungal load were found for the groups that used solutions of 2% chlorhexidine and 1% hypochlorite and microwave irradiation, regardless of the association with brushing (P<0.05). CONCLUSIONS: A single immersion for 10 min in 1% sodium hypochlorite, even in the absence of brushing, proved to be a straightforward, rapid, low-cost, and effective protocol for cleaning the dentures of hospitalized patients.","pmid":"38537031","doi":"10.1590/1678-7757-2022-0381","url":"https://pubmed.ncbi.nlm.nih.gov/38537031/"},{"id":449,"title":"Identification of reaction sites and chlorinated products of purine bases and nucleosides during chlorination: a computational study.","authors":"Zhang, Fuhao; Mo, Yonghang; Cao, Xiaomin; Zhou, Yingying; Liu, Yong Dong; Zhong, Rugang","year":2024,"date":"2024 Apr 3","journal":"Organic & biomolecular chemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HOCl) released from activated leukocytes plays a significant role in the human immune system, but is also implicated in numerous diseases due to its inappropriate production. Chlorinated nucleobases induce genetic changes that potentially enable and stimulate carcinogenesis, and thus have attracted considerable attention. However, their multiple halogenation sites pose challenges to identify them. As a good complement to experiments, quantum chemical computation was used to uncover chlorination sites and chlorinated products in this study. The results indicate that anion salt forms of all purine compounds play significant roles in chlorination except for adenosine. The kinetic reactivity order of all reaction sites in terms of the estimated apparent rate constant k(obs-est) (in M(-1) s(-1)) is heterocyclic NH/N (10(2)-10(7)) > exocyclic NH(2) (10(-2)-10) > heterocyclic C8 (10(-5)-10(-1)), but the order is reversed for thermodynamics. Combining kinetics and thermodynamics, the numerical simulation results show that N9 is the most reactive site for purine bases to form the main initial chlorinated product, while for purine nucleosides N1 and exocyclic N(2)/N(6) are the most reactive sites to produce the main products controlled by kinetics and thermodynamics, respectively, and C8 is a possible site to generate the minor product. The formation mechanisms of biomarker 8-Cl- and 8-oxo-purine derivatives were also investigated. Additionally, the structure-kinetic reactivity relationship study reveals a good correlation between lg k(obs-est) and APT charge in all purine compounds compared to FED(2) (HOMO), which proves again that the electrostatic interaction plays a key role. The results are helpful to further understand the reactivity of various reaction sites in aromatic compounds during chlorination.","pmid":"38516867","doi":"10.1039/d3ob02111d","url":"https://pubmed.ncbi.nlm.nih.gov/38516867/"},{"id":450,"title":"ROS signaling in innate immunity via oxidative protein modifications.","authors":"Manoharan, Renuka Ramalingam; Prasad, Ankush; Pospíšil, Pavel; Kzhyshkowska, Julia","year":2024,"date":"2024","journal":"Frontiers in immunology","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"The innate immune response represents the first-line of defense against invading pathogens. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) have been implicated in various aspects of innate immune function, which involves respiratory bursts and inflammasome activation. These reactive species widely distributed within the cellular environment are short-lived intermediates that play a vital role in cellular signaling and proliferation and are likely to depend on their subcellular site of formation. NADPH oxidase complex of phagocytes is known to generate superoxide anion radical (O(2) (•-)) that functions as a precursor for antimicrobial hydrogen peroxide (H(2)O(2)) production, and H(2)O(2) is utilized by myeloperoxidase (MPO) to generate hypochlorous acid (HOCl) that mediates pathogen killing. H(2)O(2) modulates the expression of redox-responsive transcriptional factors, namely NF-kB, NRF2, and HIF-1, thereby mediating redox-based epigenetic modification. Survival and function of immune cells are under redox control and depend on intracellular and extracellular levels of ROS/RNS. The current review focuses on redox factors involved in the activation of immune response and the role of ROS in oxidative modification of proteins in macrophage polarization and neutrophil function.","pmid":"38515749","doi":"10.3389/fimmu.2024.1359600","url":"https://pubmed.ncbi.nlm.nih.gov/38515749/"},{"id":455,"title":"Inhalation of gaseous hypochlorous acid and its effect on human respiratory epithelial cells in laboratory model systems.","authors":"Muramatsu, Takashi; Kodama, Kazuya; Yamada, Tetsuyoshi; Yamada, Atsushi; Fukuzaki, Satoshi","year":2024,"date":"2024","journal":"Journal of microorganism control","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"During the disinfection of indoor spaces using gaseous hypochlorous acid (HOCl((g))), inhalation is the most common route of exposure for humans. In this study, an artificial human respiratory tract model was exposed to 12-140 ppb HOCl((g)) at an aspiration flow rate of 800 mL/s for 15 h in a 1 m(3) chamber. The respiratory tract model was equipped with 5th order bronchi and all gas-contact parts were made of silicone rubber with no other chlorine-consuming substances. The concentration of HOCl((g)) reaching the lung pseudo-space was approximately 47.4% of the HOCl((g)) concentrations in the chamber and was calculated to be very close to zero when the chamber concentration was less than 20.5 ppb. The disappearance of HOCl((g)) during inhalation is likely due to the adsorption of HOCl((g)) on the gas-contact silicone rubber surfaces. The cytotoxicity of HOCl((g)) on respiratory epithelial cells was also examined using human air-liquid-interface airway tissue models. Human nasal epithelium and bronchiolar epithelium were exposed to 100 ppb and 500 ppb HOCl((g)) for 8 h and 5 d, respectively. No significant effects of HOCl((g)) on cell viability and ciliary activity were observed in any cell type, indicating that low concentrations of HOCl((g）), less than 500 ppb, had no cytotoxic effect.","pmid":"38508761","doi":"10.4265/jmc.29.1_39","url":"https://pubmed.ncbi.nlm.nih.gov/38508761/"},{"id":461,"title":"Simultaneous determination of environmental endocrine disruptors bisphenol A and 4-nitrophenol bleached from food-contacting materials using the spin-ladder compound La(2)Cu(2)O(5) modified glassy carbon electrode.","authors":"Mayil Vealan, S B; Chinnathambi, Sekar","year":2024,"date":"2024 Apr","journal":"Chemosphere","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Environmental endocrine-disrupting chemicals, Bisphenol A (BPA) and 4-Nitrophenol (4-NP), pose significant risks to reproductive health in both animals and humans. Here, we introduce the first utilization of the 4-leg spin ladder compound La(2)Cu(2)O(5) as an electrode material for electrochemical sensor. Nanostructured La(2)Cu(2)O(5) was synthesized via a straightforward Sol-Gel method and thoroughly characterized using X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and powder X-ray diffraction. La(2)Cu(2)O(5) nanoparticles modified glassy carbon electrode (GCE) exhibited a significant electrocatalytic activity towards the oxidation of BPA and 4-NP in phosphate buffer saline (pH 7.0). Square wave voltammetry studies revealed lowest detection limits of 3 nM for BPA and 2.6 nM for 4-NP over a wider concentration range of 0.01-500 μM. Notably, this study marks the first utilization of La(2)Cu(2)O(5) for simultaneous electrochemical detection of BPA and 4-NP, demonstrating its potential in this field. Furthermore, the sensor exhibited good sensitivity, reproducibility, and selectivity towards BPA and 4-NP, even in the presence of similar potential organic and inorganic interferents. Additionally, the newly developed sensor enabled simultaneous quantification of BPA and 4-NP in real samples such as packaged milk, river water, and plastic bottles, achieving recovery rates above 95%. Importantly, our results underscore the leaching of BPA into water from thin and thick plastics at elevated temperatures (40 °C-80 °C), emphasizing the utility of the proposed sensor for rapid and simultaneous detection of BPA and 4-NP in environmental and food matrices.","pmid":"38417491","doi":"10.1016/j.chemosphere.2024.141559","url":"https://pubmed.ncbi.nlm.nih.gov/38417491/"},{"id":474,"title":"Uses of gaseous hypochlorous acid for controlling microorganisms in indoor spaces.","authors":"Fukuzaki, Satoshi","year":2023,"date":"2023","journal":"Journal of microorganism control","category":"Food & agriculture","evidence":"Review","relevance":"High","abstract":"Hypochlorous acid (HOCl) is an active species in the chlorination process. Hypochlorite salts that release hypochlorite ion (OCl(-)) have been used for more than 200 years as disinfecting, cleaning, deodorizing, and decolorizing agents in various technological fields. In the food industry, sodium hypochlorite is the most widely used among chlorine compounds. The antimicrobial activity of a dilute hypochlorite solution is attributed largely to HOCl because of its cell membrane permeability. OCl(-) exhibits an excellent cleaning action for organic soils on solid surfaces. HOCl has been used as an aqueous solution, and its objects to be treated are things. In hypochlorite solution, HOCl is volatile and easily volatilized by stirring, bubbling, atomizing, or forced-air vaporization. On the other hand, OCl(-) is non-volatile and stays in the solution. Recently, the scope of objects to be treated with hypochlorite solution has been expanded to indoor spaces, and the use of gaseous hypochlorous acid (HOCl(（g)) ) has been studied intensively. This review describes the mechanisms of actions of hypochlorous acid as liquid-based and gaseous disinfectants and provides the evidence for the safety and effectiveness of HOCl(（g)) for controlling microorganisms in indoor spaces.","pmid":"38233168","doi":"10.4265/jmc.28.4_165","url":"https://pubmed.ncbi.nlm.nih.gov/38233168/"},{"id":477,"title":"HOCl-producing electrochemical bandage for treating Pseudomonas aeruginosa-infected murine wounds.","authors":"Fleming, Derek; Bozyel, Ibrahim; Ozdemir, Dilara; Otero, Judith Alvarez; Karau, Melissa J; Anoy, Md Monzurul Islam; Koscianski, Christina; Schuetz, Audrey N; Greenwood-Quaintance, Kerryl E; Mandrekar, Jayawant N; Beyenal, Haluk; Patel, Robin","year":2024,"date":"2024 Feb 7","journal":"Antimicrobial agents and chemotherapy","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"The growing threat of antibiotic-resistant bacterial pathogens necessitates the development of alternative antimicrobial approaches. This is particularly true for chronic wound infections, which commonly harbor biofilm-dwelling bacteria. A novel electrochemical bandage (e-bandage) delivering low-levels of hypochlorous acid (HOCl) was evaluated against Pseudomonas aeruginosa murine wound biofilms. 5 mm skin wounds were created on the dorsum of mice and infected with 10(6) colony-forming units (CFU) of P. aeruginosa. Biofilms were formed over 2 days, after which e-bandages were placed on the wound beds and covered with Tegaderm. Mice were administered Tegaderm-only (control), non-polarized e-bandage (no HOCl production), or polarized e-bandage (using an HOCl-producing potentiostat), with or without systemic amikacin. Purulence and wound areas were measured before and after treatment. After 48 hours, wounds were harvested for bacterial quantification. Forty-eight hours of polarized e-bandage treatment resulted in mean biofilm reductions of 1.4 log(10) CFUs/g (P = 0.0107) vs non-polarized controls and 2.2 log(10) CFU/g (P = 0.004) vs Tegaderm-only controls. Amikacin improved CFU reduction in Tegaderm-only (P = 0.0045) and non-polarized control groups (P = 0.0312) but not in the polarized group (P = 0.3876). Compared to the Tegaderm-only group, there was less purulence in the polarized group (P = 0.009). Wound closure was neither impeded nor improved by either polarized or non-polarized e-bandage treatment. Concurrent amikacin did not impact wound closure or purulence. In conclusion, an HOCl-producing e-bandage reduced P. aeruginosa in wound biofilms with no impairment in wound healing, representing a promising antibiotic-free approach for addressing wound infection.","pmid":"38214514","doi":"10.1128/aac.01216-23","url":"https://pubmed.ncbi.nlm.nih.gov/38214514/"},{"id":480,"title":"N-aminomorpholine-functionalized bromine-doped carbon dots for hypochlorous acid detection in foods and imaging in live cells.","authors":"Zhao, Chengda; Yuan, Pengxiang; Wang, Dan; Li, Shiyao; Yao, Huan; Yang, Liu-Pan; Wang, Li-Li; Du, Fangfang","year":2024,"date":"2024 May 30","journal":"Food chemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HClO) is used in food preservation. However, excessive HClO can deteriorate nutritional composition of food, compromise its quality, and potentially induce various diseases. Consequently, the development of multifunctional fluorescent probes for the sensitive and selective detection of HClO is highly anticipated for food safety. In this work, we designed a nanoprobe using N-aminomorpholine (AM)-functionalized bromine-doped carbon dots (Br-CDs-AM) for sensing HClO. This nanoprobe exhibits pH stability, strong resistance to photobleaching, superior long-term photostability (12 weeks), high sensitivity (19.3 nM), and an ultrarapid response (8 s) for detecting HClO residues in food matrices with percentage recovery (96.5 %-108 %) and RSDs less than 5.34 %. In addition, extremely low cytotoxicity and outstanding biocompatibility enable the nanoprobe to be used primarily for lysosome tracking and rapidly visualizing HClO in live cells. Thus, this study provides a new pathway to design unconventional nanoprobes for food safety assessment and subcellular organelle-specific imaging HClO.","pmid":"38181668","doi":"10.1016/j.foodchem.2023.138284","url":"https://pubmed.ncbi.nlm.nih.gov/38181668/"},{"id":482,"title":"Construction of optical dual-mode sensing platform based on green emissive carbon quantum dots for effective detection of ClO(-) and cellular imaging.","authors":"Chen, Huajie; Li, Dai; Zheng, Yutao; Wang, Kui; Zhang, He; Feng, Zhipeng; Huang, Bolin; Wen, Huiyun; Wu, Jiyong; Xue, Weiming; Huang, Saipeng","year":2024,"date":"2024 Mar 15","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Hypochlorite (ClO(-)) is an important redox regulator in reactive oxygen species, which play a considerable role in oxidative stress and related diseases. Hence, accurate and sensitive monitoring of ClO(-) concentration was urgently needed in the fields of life sciences, food and environment. Bright green fluorescent carbon quantum dots (G-CQDs) were synthesized utilizing one-step hydrothermal method with citric acid and acriflavine precursors. Through TEM, FTIR, XPS and zeta potential characterization procedures, G-CQDs illustrated uniformly dispersed and significant number of -NH(2) and -OH on the surface. Meanwhile, the fluorescence and colorimetric analysis exhibited wide linear range and low detection limit response to ClO(-). The fluorescence changes of G-CQDs were identified via smartphone to realize mobile sensing of ClO(-). Subsequently, G-CQDs was applied for visualization and quantitative detection of ClO(-) in drinking water samples with satisfactory recovery rate. More importantly, G-CQDs demonstrated good water solubility, optical stability and excellent biocompatibility, which offered a promising analysis approach in cell imaging and exogenous ClO(-) detection in living cells. G-CQDs illustrated bright prospect and great potential in practical application of ClO(-) associated disease prevention and early clinical diagnosis.","pmid":"38157745","doi":"10.1016/j.saa.2023.123733","url":"https://pubmed.ncbi.nlm.nih.gov/38157745/"},{"id":484,"title":"Bleached enamel reversal using grape seed extract, green tea, curcumin-activated photodynamic therapy, and Er: YAG on microleakage and bond integrity of composite material bonded to the enamel surface.","authors":"Almohareb, Thamer; Al Ahdal, Khold; Maawadh, Ahmed M; Al Deeb, Laila; Alshamrani, Ahoud S; Alrahlah, Ali","year":2024,"date":"2024 Feb","journal":"Photodiagnosis and photodynamic therapy","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"AIMS: Bleached enamel reversal using antioxidants sodium ascorbate (SA), Green tea extract (GTE), grape seed extract (GSE), Curcumin photosensitizer (CP) and Er: YAG laser on the adhesive strength and marginal leakage of composite material bonded to the bleached enamel surface. MATERIALS AND METHODS: Enamel surface of hundred and twenty sound human first premolar teeth was cleansed using pumice and bleached with 35 % hydrogen peroxide. The samples were randomly divided into 5 groups based on the antioxidants used. n = 20 Group 1 (Control): No antioxidant agent, Group 2: 10 % SA solution, Group 3: 6.5 % GSE, Group 4: 5 % GTE, Group 5: Er: YAG laser and Group 6: CP. Following reversal, the composite was built and cured for 40 s. All the specimens were stored in distilled water at room temperature for 1 day. Microleakage, SBS, and failure mode were analyzed. Kolmogorov-Smirnov test, one-way analysis of variance, and Tukey's multiple post hoc test were used to analyze the data statistically. RESULTS: Group 2 (SA) (20.11 ± 5.79 nm) exhibited minimum value of microleakage and highest SBS (10.22 ± 1.62 MPa). Whereas, Group 1 (No antioxidant agent) displayed maximum scores of marginal leakage (28.11±8.89 nm) and lowest SBS (7.02 ± 1.22 MPa). CONCLUSION: CP, GTE and GSE can be used as a potential alternative to the commonly used SA solution to reverse the negative impact of bleaching on the enamel surface. The use of reversal agents CP, GTE and GSE improves bond values with a decrease in microleakage scores However, future studies are still warranted to conclude the outcomes of the existing study.","pmid":"38145770","doi":"10.1016/j.pdpdt.2023.103943","url":"https://pubmed.ncbi.nlm.nih.gov/38145770/"},{"id":487,"title":"A novel thienothiophene-based \"dual-responsive\" probe for rapid, selective and sensitive detection of hypochlorite.","authors":"Suna, Garen; Erdemir, Eda; Liv, Lokman; Karakus, Aysenur Cataler; Gunturkun, Dilara; Ozturk, Turan; Karakuş, Erman","year":2024,"date":"2024 Apr 1","journal":"Talanta","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"BACKGROUND: Hypochlorite/hypochlorous acid (ClO(-)/HOCl) is a biologically crucial reactive oxygen species (ROS), produced in living organisms and has a critical role as an antimicrobial agent in the natural defense system. However, when ClO(-) is produced excessively, it can lead to the oxidative damage of biomolecules, resulting in organ damage and various diseases. Therefore, it is imperative to have a straightforward, quick and reliable method for over watching the minimum amount of ClO(-) in different environments. RESULTS: Herein, a new probe TTM, containing thienothiophene and malononitrile units, was developed for exceptionally selective and sensitive hypochlorite (ClO(-)) detection. TTM demonstrated a rapid \"turn-on\" fluorescence response (<30 s), naked-eye detection (colorimetric), voltammetric read-out with anodic scan, low detection limit (LOD = 0.58 μM and 1.43 μM for optical and electrochemical methods, respectively) and applicability in detecting ClO(-) in real water samples and living cells. SIGNIFICANCE AND NOVELTY: This study represents one of the rare examples of a small thienothiophene-based molecule for both optical and electrochemical detections of ClO(-) in an aqueous medium.","pmid":"38128280","doi":"10.1016/j.talanta.2023.125545","url":"https://pubmed.ncbi.nlm.nih.gov/38128280/"},{"id":489,"title":"Effects of alpha-tocopherol antioxidant on fracture strength and adhesion of endodontically treated teeth restored after dental bleaching.","authors":"Marcomini, Natália; Albaricci, Maria Carolina da Costa; Costa, Joatan Lucas de Sousa Gomes; Besegato, João Felipe; Godoy, Eduardo Fernández; Dantas, Andréa Abi Rached; Kuga, Milton Carlos","year":2024,"date":"2024 Feb","journal":"European journal of oral sciences","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"This study evaluated the effect of different concentrations of alpha-tocopherol in gel form on fracture strength, hybrid layer formation, and microtensile bond strength of endodontically treated teeth bleached with 40% hydrogen peroxide (H(2) O(2) ). Sixty bovine incisors were randomized into one of six groups (n = 10 incisors per group) defined by the interventions carried out after endodontic treatment. In the control group, no additional intervention was carried out, while all teeth in the five intervention groups were bleached with 40% H(2) O(2) and subsequently treated with alpha-tocopherol at concentrations of 15% (15AT), 20% (20AT), or 25% (25AT), with 10% sodium ascorbate (10SA), or with nothing (40HP). Fracture strength was evaluated in a mechanical testing machine, hybrid layer formation was assessed using scanning electron microscopy, and bond strength was determined using microtensile bond-strength testing. Data were analyzed using Kruskal-Wallis and Dunn's tests. No statistically significant difference regarding fracture strength was observed among groups. Hybrid layer formation was greater in the 15AT group than in groups 40HP and 10SA. Teeth in groups 15AT, 20AT, and 25AT demonstrated higher bond strength than teeth in groups 40HP and 10SA. Alpha-tocopherol, preferably at 15%, effectively reverses the deleterious effects, of bleaching, on hybrid layer formation and bond strength to dentin.","pmid":"38115770","doi":"10.1111/eos.12965","url":"https://pubmed.ncbi.nlm.nih.gov/38115770/"},{"id":490,"title":"Dual-channel versatile molecular sensing platform for individual and successive HClO and H(2)S detection: Applicable in toxic alerts of environmental samples and living organisms.","authors":"Chen, Song; Liu, Xiangbao; Li, Qi; Fu, Shuang; Zhang, Hongguang; Li, Shuang; Wang, Luan; He, Chuan; Chen, Wenqiang; Hou, Peng","year":2024,"date":"2024 Mar 5","journal":"Journal of hazardous materials","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"In this study, we have successfully developed a novel dual-response fluorescent probe, NACou, designed for the visual and quantitative detection of HClO/H(2)S in real water samples and liquid beverages by a thin-film sensing platform. Additionally, NACou demonstrated efficacy for sensing HClO/H(2)S in HeLa cells, plants and zebrafish through distinct fluorescent channels, yielding satisfactory results. NACou exhibited a multi-modal fluorescence response mechanism for detecting HClO and H(2)S with remarkable low detection limits of 27.8 nM and 34.4 nM, accompanied by outstanding fluorescent enhancement (209-fold and 148-fold, respectively). These advantages position NACou as a potent molecular tool for HClO and H(2)S sensing. The specific recognition performance of NACou towards HClO/H(2)S were confirmed through fluorescence spectroscopy, mass analysis and UV-vis spectroscopy. Importantly, the thin-film sensing platform with the visible fluorescence change can enable rapid assays for water quality and food safety monitoring, showcasing significant practical application value. Impressively, NACou has been employed in warning against liver injury induced by multiple drugs, allowing for the exploration of the pathogenesis and degree of drug-induced injury.","pmid":"38103299","doi":"10.1016/j.jhazmat.2023.133253","url":"https://pubmed.ncbi.nlm.nih.gov/38103299/"},{"id":491,"title":"Hypochlorous acid hygiene solution in patients affected by blepharitis: a prospective randomised study.","authors":"Mencucci, Rita; Morelli, Alberto; Favuzza, Eleonora; Galano, Angelo; Roszkowska, Anna Maria; Cennamo, Michela","year":2023,"date":"2023 Dec 7","journal":"BMJ open ophthalmology","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"BACKGROUND/AIMS: To investigate the clinical outcomes and antimicrobial activity of an hypochlorous acid hygiene solution compared with hyaluronic acid wipes for blepharitis treatment in patients with dry eye disease (DED). METHODS: This study involved 48 eyes of 48 patients affected by blepharitis with mild to moderate DED. 24 patients were treated with a hypochlorous acid hygiene solution (HOCL group) and 24 patients were treated with hyaluronic acid wipes (HYAL group) for a period of 4 weeks. The following clinical outcomes were assessed before (V0) and after the treatment period (V1): non-invasive keratograph break up time (NIK-BUT), tear film BUT (TF-BUT) tear meniscus height (TMH), Keratograph meibography, Meibomian Gland Yield Secretion Score (MGYSS), Corneal Staining Score (CSS), Schirmer test I, Keratograph conjunctival redness score and Ocular Surface Disease Index (OSDI). Moreover, microbiological analysis of upper and lower eyelid margins was performed at V0 both before and 5 min after treatment. RESULTS: After 1-month NIK-BUT and TF-BUT significantly increased in HOCL group, while they did not show a statistically significant difference in HYAL group compared with baseline. OSDI, TMH and MGYSS showed a significant difference in both groups, while Schirmer test, meibography, CSS and conjunctival redness score did not significantly change in both groups. Bacterial load showed a significant reduction in both groups, more pronounced in HOCL group compared with HYAL group. CONCLUSIONS: Hypochlorous acid hygiene solution can be securely employed in blepharitis treatment considering the satisfying clinical outcomes and antimicrobial activity compared with hyaluronic acid wipes.","pmid":"38088255","doi":"10.1136/bmjophth-2022-001209","url":"https://pubmed.ncbi.nlm.nih.gov/38088255/"},{"id":494,"title":"From Oxidized Fatty Acids to Dimeric Species: In Vivo Relevance, Generation and Methods of Analysis.","authors":"Leopold, Jenny; Prabutzki, Patricia; Engel, Kathrin M; Schiller, Jürgen","year":2023,"date":"2023 Nov 29","journal":"Molecules (Basel, Switzerland)","category":"Food & agriculture","evidence":"Review","relevance":"High","abstract":"The occurrence of free fatty acids (FFAs) and the generation of reactive oxygen species (ROS) such as hydroxyl radicals (HO(●)) or hypochlorous acid (HOCl) is characteristic of inflammatory diseases, for instance, rheumatoid arthritis. Unsaturated fatty acids react with ROS yielding a variety of important products such as peroxides and chlorohydrins as primary and chain-shortened compounds (e.g., aldehydes and carboxylic acids) as secondary products. These modified fatty acids are either released from phospholipids by phospholipases or oxidatively modified subsequent to their release. There is increasing evidence that oligomeric products are also generated upon these processes. Fatty acid esters of hydroxy fatty acids (FAHFAs) are considered as very important products, but chlorinated compounds may be converted into dimeric and (with smaller yields) oligomeric products, as well. Our review is structured as follows: first, the different types of FFA oligomers known so far and the mechanisms of their putative generation are explained. Industrially relevant products as well as compounds generated from the frying of vegetable oils are also discussed. Second, the different opinions on whether dimeric fatty acids are considered as \"friends\" or \"foes\" are discussed.","pmid":"38067577","doi":"10.3390/molecules28237850","url":"https://pubmed.ncbi.nlm.nih.gov/38067577/"},{"id":496,"title":"Topical Stabilized Super-Oxidized Hypochlorous Acid for Wound Healing in Hair Restoration Surgery: A Real-Time Usage-Controlled Trial Evaluating Safety, Efficacy, and Tolerability.","authors":"Stough, Dow","year":2023,"date":"2023 Dec 1","journal":"Journal of drugs in dermatology : JDD","category":"Human clinical & healthcare","evidence":"Clinical trial","relevance":"Medium","abstract":"OBJECTIVE: Assess the perceived efficacy of stabilized, super-oxidized hypochlorous acid (HOCl) in hair transplant surgical procedures intraoperative and postoperative. BACKGROUND: Stabilized, super-oxidized hypochlorous acid (HOCl) is highly effective against bacterial, fungal, and viral microorganisms. In addition, topical HOCl will increase tissue oxygenation of wound sites to aid in healing. This molecule represents an ideal agent for intraoperative and postoperative use in hair restoration procedures that involve thousands of small wounds. METHODS: 35 patients were enrolled in a multi-site study following repeat or initial hair restoration surgery. Surgeons were provided a 500 mL trigger spray bottle of HOCl spray liquid for use prior to and throughout the surgical procedure. Patients were provided with a ten-day supply of HOCl for postoperative care. Two formulations were utilized, one was applied to the recipient sites while the other was applied to the donor area postoperatively. Patients and surgeons were provided with observational surveys regarding healing and usage of the products. RESULTS: Statistical analysis found 56% had significant reduction in the amount of erythema compared to their current wound healing regimen. More than half of the patients (54%) had significant improvement of pruritus. The compliance rating for this study was 97% among patients. Surgeons were queried on the overall efficacy. There were no incidences of donor or recipient tissue necrosis. CONCLUSION: The evolution of hair restoration surgery has been accompanied by large numbers of grafts being implanted. This change necessitates the requirement for optimum intraoperative and postoperative care. Topical, stabilized hypochlorous spray represents a major advance in wound cleansing and healing and offers the theoretical benefits of reducing tissue necrosis through oxygenation. J Drugs Dermatol. 2023;22(12):1191-1196. doi:10.36849/JDD.7172.","pmid":"38051837","doi":"10.36849/JDD.7172","url":"https://pubmed.ncbi.nlm.nih.gov/38051837/"},{"id":498,"title":"Candida albicans resistance to hypochlorous acid.","authors":"Douglas, Lois M; Min, Kyunghun; Konopka, James B","year":2023,"date":"2023 Dec 19","journal":"mBio","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Hypochlorous acid (HOCl), commonly known as bleach, is generated during the respiratory burst by phagocytes and is a key weapon used to attack Candida albicans and other microbial pathogens. However, the effects of hypochlorous acid on C. albicans have been less well studied than H(2)O(2), a different type of oxidant produced by phagocytes. HOCl kills C. albicans more effectively than H(2)O(2) and results in disruption of the plasma membrane. HOCl induced a very different transcriptional response than H(2)O(2), and there were significant differences in the susceptibility of mutant strains of C. albicans to these oxidants. Altogether, these results indicate that HOCl has distinct effects on cells that could be targeted in novel therapeutic strategies to enhance the killing of C. albicans and other pathogens.","pmid":"38032204","doi":"10.1128/mbio.02671-23","url":"https://pubmed.ncbi.nlm.nih.gov/38032204/"},{"id":499,"title":"Efficacy of hypochlorous acid as an alternative oral antimicrobial agent on human gingival fibroblasts, Aggregatibacter actinomycetemcomitans, and Candida albicans biofilms in vitro.","authors":"Bayraktar, Gözdem; Yılmaz Göler, Ayşe Mine; Aksu, Burak; Öztürk Özener, Hafize","year":2023,"date":"2023 Oct-Nov","journal":"Biofouling","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"This study compared the cytotoxicity and antimicrobial activity of hypochlorous acid (HOCl) at 50 ppm and 200 ppm and 0.2% chlorhexidine (CHX) at various time intervals, in vitro. Cell viability and cytotoxicity of human gingival fibroblasts (HGF) were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and the lactate dehydrogenase assay. Antimicrobial effects on Aggregatibacter actinomycetemcomitans and Candida albicans were determined using the time-kill method. All solutions exhibited a significant impact on HGFs in a dose- and time-dependent manner. 50 ppm HOCl demonstrated the highest cell viability, followed by 200 ppm HOCl. Both HOCl solutions were less cytotoxic to HGFs than 0.2% CHX. 50 ppm and 200 ppm HOCl demonstrated stronger efficiencies than CHX against A. actinomycetemcomitans and C. albicans. The data suggest that HOCl solutions have potential as an alternative antiseptic to CHX due to their lower cytotoxicity and superior antimicrobial activity, but optimal dosage of HOCl requires further investigations.","pmid":"38018019","doi":"10.1080/08927014.2023.2288071","url":"https://pubmed.ncbi.nlm.nih.gov/38018019/"},{"id":500,"title":"Gas-Phase and Surface-Initiated Reactions of Household Bleach and Terpene-Containing Cleaning Products Yield Chlorination and Oxidation Products Adsorbed onto Indoor Relevant Surfaces.","authors":"Deeleepojananan, Cholaphan; Grassian, Vicki H","year":2023,"date":"2023 Dec 12","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The use of household bleach cleaning products results in emissions of highly oxidative gaseous species, such as hypochlorous acid (HOCl) and chlorine (Cl(2)). These species readily react with volatile organic compounds (VOCs), such as limonene, one of the most abundant compounds found in indoor enviroments. In this study, reactions of HOCl/Cl(2) with limonene in the gas phase and on indoor relevant surfaces were investigated. Using an environmental Teflon chamber, we show that silica (SiO(2)), a proxy for window glass, and rutile (TiO(2)), a component of paint and self-cleaning surfaces, act as a reservoir for adsorption of gas-phase products formed between HOCl/Cl(2) and limonene. Furthermore, high-resolution mass spectrometry (HRMS) shows that the gas-phase reaction products of HOCl/Cl(2) and limonene readily adsorb on both SiO(2) and TiO(2). Surface-mediated reactions can also occur, leading to the formation of new chlorine- and oxygen-containing products. Transmission Fourier-transform infrared (FTIR) spectroscopy of adsorption and desorption of bleach and terpene oxidation products indicates that these chlorine- and oxygen-containing products strongly adsorb on both SiO(2) and TiO(2) surfaces for days, providing potential sources of human exposure and sinks for additional heterogeneous reactions.","pmid":"38010858","doi":"10.1021/acs.est.3c06656","url":"https://pubmed.ncbi.nlm.nih.gov/38010858/"},{"id":507,"title":"New diamond coatings for a safer electrolytic disinfection.","authors":"Gimenes Vernasqui, Laís; de Oliveira Santiago Santos, Gessica; Isidro, Julia; Oliveira Silva, Taynara; de Vasconcelos Lanza, Marcos Roberto; Saez, Cristina; Gomes Ferreira, Neidenei; Rodrigo Rodrigo, Manuel Andres","year":2023,"date":"2023 Nov","journal":"Environmental science and pollution research international","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"In this work, a new coating of boron-doped diamond ultra-nanocrystalline (U-NBDD), tailored to prevent massive formation of perchlorates during disinfection, is evaluated as electrode for the reclaiming of treated secondary wastewater by the electrochemically assisted disinfection process. Results obtained are compared to those obtained by using a standard electrode (STD) that was evaluated as a standard in previous research showing outstanding performance for this application. First tests were carried out to evaluate the chlorine speciation obtained after the electrolysis of synthetic chloride solutions at two different ranges of current densities. Concentrations of hypochlorite obtained using the U-NBDD anode at 25 mA cm(-2) were 1.5-fold higher, outperforming STD anode; however, at 300 mA cm(-2), an overturn on the behavior of anodes occurs where the amount of hypochlorite produced on STD anode was 1.5-fold higher. Importantly, at low current density the formation of chlorates and perchlorates is null using U-NBDD. Then, the disinfection of the real effluent of the secondary clarifier of a municipal wastewater treatment facility is assessed, where inactivation of Escherichia coli is achieved at low charge applied per volume electrolyzed (0.08 A h L(-1)) at 25 mA cm(-2) using the U-NBDD. These findings demonstrate the appropriateness of the strategy followed in this work to obtain safer electro-disinfection technologies for the reclaiming of treated wastewater.","pmid":"37875760","doi":"10.1007/s11356-023-30407-w","url":"https://pubmed.ncbi.nlm.nih.gov/37875760/"},{"id":512,"title":"A unique phenothiazine-based fluorescent probe using benzothiazolium as a reactivity regulator for the specific detection of hypochlorite in drinking water and living organisms.","authors":"Fang, Jie; Li, Xiang; Gao, Chao; Gao, Shihao; Li, Wei; Seidu, Mohammed Awal; Zhou, Hongjun","year":2024,"date":"2024 Feb 1","journal":"Talanta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"As a common disinfectant and an essential reactive oxygen species (ROS), hypochlorite (ClO(-)) plays vital roles in both water treatment and cell metabolism, but its abnormal level can cause serious harm to human health. Therefore, quantifying ClO(-) level in drinking water and living organisms is extremely significant. Herein, we decorated different cationic heterocycles on phenothiazine core to construct three fluorescent probes for ClO(-). According to the results, only benzothiazolium moiety reasonably adjusted the electron cloud density at sulfur atom of phenothiazine core for the specific oxidation with ClO(-), thus endowing the prepared probe PT-BT with a perfect selectivity for ClO(-). Meanwhile, PT-BT exhibited a low detection limit (38 nM) and a fast response (within 20 s) toward ClO(-). Furthermore, this probe was utilized to fabricate a ready-to-use test strip, which could quantitatively measure ClO(-) level in real water samples by a portable smartphone sensing platform. Notably, PT-BT targeted mitochondria efficiently, and successfully visualized endogenous ClO(-) in living cells and zebrafish larvae. Especially, PT-BT was able to monitor the dynamic change of ClO(-) level in inflammatory mice. These results strongly manifested that probe PT-BT was a promising tool for detecting ClO(-) in drinking water and living organisms.","pmid":"37832451","doi":"10.1016/j.talanta.2023.125299","url":"https://pubmed.ncbi.nlm.nih.gov/37832451/"},{"id":513,"title":"Bifunctional near-infrared fluorescent probe for the selective detection of bisulfite and hypochlorous acid in food, water samples and in vivo.","authors":"Shang, Zhuye; Meng, Qingtao; Zhang, Run; Zhang, Zhiqiang","year":2023,"date":"2023 Oct 23","journal":"Analytica chimica acta","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"We report the development of a bifunctional near-infrared fluorescent probe (QZB) for selective sensing of bisulfite (HSO(3)(-)) and hypochlorous acid (HOCl). The synergistic detection of HSO(3)(-) and HOCl was achieved via a C=C bond recognition site. In comparison with the red-fluorescence QZB, two different products with non-fluorescence and paleturquoise fluorescence were produced by the recognition of QZB towards HSO(3)(-) and HOCl respectively, which can realize effectively the dual-functional detection of HSO(3)(-) and HOCl. QZB features prominent preponderances of dual-function response, near-infrared emission, reliability at physiological pH, low cytotoxicity and high sensitivity to HSO(3)(-) and HOCl. The detection of HSO(3)(-) in actual food samples has been successfully achieved using QZB. Utilization of QZB-based test strip to semi-quantitatively detect HSO(3)(-) and HOCl in real-world water samples by the \"naked-eye\" colorimetry are then demonstrated. Simultaneously, the determination of HSO(3)(-) and HOCl in real-world water sample has been achieved by smartphone-based standard curves. Additionally, the applications of QZB for imaging HSO(3)(-) and HOCl in vivo are successfully demonstrated. Consequently, the successful development of QZB could be promising as an efficient tool for researching the role of HSO(3)(-)/HOCl in the regulation of redox homeostasis regulation in vivo and complex signal transduction and for future food safety evaluation.","pmid":"37827680","doi":"10.1016/j.aca.2023.341783","url":"https://pubmed.ncbi.nlm.nih.gov/37827680/"},{"id":516,"title":"Expression of RcrB confers resistance to hypochlorous acid in uropathogenic Escherichia coli.","authors":"Crompton, Mary E; Gaessler, Luca F; Tawiah, Patrick O; Polzer, Lisa; Camfield, Sydney K; Jacobson, Grady D; Naudszus, Maren K; Johnson, Colton; Meurer, Kennadi; Bennis, Mehdi; Roseberry, Brendan; Sultana, Sadia; Dahl, Jan-Ulrik","year":2023,"date":"2023 Oct 26","journal":"Journal of bacteriology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"To eradicate bacterial pathogens, neutrophils are recruited to the sites of infection, where they engulf and kill microbes through the production of reactive oxygen and chlorine species (ROS/RCS). The most prominent RCS is the antimicrobial oxidant hypochlorous acid (HOCl), which rapidly reacts with various amino acid side chains, including those containing sulfur and primary/tertiary amines, causing significant macromolecular damage. Pathogens like uropathogenic Escherichia coli (UPEC), the primary causative agent of urinary tract infections, have developed sophisticated defense systems to protect themselves from HOCl. We recently identified the RcrR regulon as a novel HOCl defense strategy in UPEC. Expression of the rcrARB operon is controlled by the HOCl-sensing transcriptional repressor RcrR, which is oxidatively inactivated by HOCl resulting in the expression of its target genes, including rcrB. The rcrB gene encodes a hypothetical membrane protein, deletion of which substantially increases UPEC's susceptibility to HOCl. However, the mechanism behind protection by RcrB is unclear. In this study, we investigated whether (i) its mode of action requires additional help, (ii) rcrARB expression is induced by physiologically relevant oxidants other than HOCl, and (iii) expression of this defense system is limited to specific media and/or cultivation conditions. We provide evidence that RcrB expression is sufficient to protect E. coli from HOCl. Furthermore, RcrB expression is induced by and protects from several RCS but not from ROS. RcrB plays a protective role for RCS-stressed planktonic cells under various growth and cultivation conditions but appears to be irrelevant for UPEC's biofilm formation. IMPORTANCE Bacterial infections pose an increasing threat to human health, exacerbating the demand for alternative treatments. Uropathogenic Escherichia coli (UPEC), the most common etiological agent of urinary tract infections (UTIs), are confronted by neutrophilic attacks in the bladder, and must therefore be equipped with powerful defense systems to fend off the toxic effects of reactive chlorine species. How UPEC deal with the negative consequences of the oxidative burst in the neutrophil phagosome remains unclear. Our study sheds light on the requirements for the expression and protective effects of RcrB, which we recently identified as UPEC's most potent defense system toward hypochlorous acid (HOCl) stress and phagocytosis. Thus, this novel HOCl stress defense system could potentially serve as an attractive drug target to increase the body's own capacity to fight UTIs.","pmid":"37791752","doi":"10.1128/jb.00064-23","url":"https://pubmed.ncbi.nlm.nih.gov/37791752/"},{"id":517,"title":"Effects of hypochlorous acid mouthwash on salivary bacteria including Staphylococcus aureus in patients with periodontal disease: a randomized controlled trial.","authors":"Lin, Ying-Chu; Tsai, Cheng-Feng; Huang, Hsiao-Ling","year":2023,"date":"2023 Sep 28","journal":"BMC oral health","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"BACKGROUND: The effects of a low concentration of hypochlorous acid (HOCl) mouthwash on salivary bacteria remained unclear. We aimed to evaluate the antibacterial effects of 100 ppm HOCl mouthwash on salivary bacteria, including Staphylococcus aureus (S. aureus), in patients with periodontal disease (PD). METHODS: Patients with PD were randomized into mouthwash-only (MW, n = 26) and mouthwash with periodontal flosser (MWPF, n = 27) groups. Patients without PD were selected for the control group (n = 30). S. aureus culture and saliva samples (before and after the intervention) were collected for bacterial DNA extraction. A real-time polymerase chain reaction assay and serial dilutions of S. aureus culture and saliva samples were used to measure the salivary bacteria total count (SBTC) and confirm the antibacterial effects of the mouthwash using S. aureus. RESULTS: No significant difference in demographic data was observed among the three groups. Before the intervention, the baseline SBTC of the MW and MWPF groups was significantly higher than that of the control group. After the mouthwash rinses, the SBTC data significantly changed in the MW and MWPF groups only (by 62.4% and 77.4%, respectively). After the base-2 log-transformation of the SBTC data, a similar trend was observed. Linear regression revealed that baseline SBTC and the MWPF intervention significantly affected SBTC reduction percentage by volume. After incubation with 10% (v/v) of mouthwash, the survival rates of 10(6) and 10(7) colony-forming units/mL of S. aureus were 0.51% ± 0.06% and 1.42% ± 0.37%, respectively. CONCLUSIONS: These study results indicated that 100 ppm HOCl mouthwash treatment could effectively reduce SBTC in patients with PD and the abundance of S. aureus. It provides that the HOCl mouthwash can be an option for individuals to help control SBTC, especially in patients with PD. TRIAL REGISTRATION: The study protocol was approved by the Institutional Review Board of Kaohsiung Medical University Hospital (KMUHIRB-F(I)-20200042) on 20/03/2020 and retrospectively registered at ClinicalTrial.gov (NCT05372835) on 13/05/2022.","pmid":"37770865","doi":"10.1186/s12903-023-03358-4","url":"https://pubmed.ncbi.nlm.nih.gov/37770865/"},{"id":519,"title":"Characterization of Olive Oil Volatile Compounds after Elution through Selected Bleaching Materials-Gas Chromatography-Mass Spectrometry Analysis.","authors":"Al-Dabbas, Maher M; Al-Jaloudi, Rawan; Abdullah, Mai Adnan; Abughoush, Mahmoud","year":2023,"date":"2023 Sep 5","journal":"Molecules (Basel, Switzerland)","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Using different bleaching materials to eliminate or reduce organic volatiles in deteriorated olive oils will positively affect its characteristics. This study aims to identify the volatiles of oxidized olive oil after physical bleaching using selected immobilized adsorbents. Oxidized olive oil was eluted using open-column chromatography packed with silica gel, bentonite, resin, Arabic gum, and charcoal at a 1:5 eluent system (w/v, adsorbent: oxidized olive oil). The smoke point was determined. The collected distilled vapor was injected into GC-MS to identify the volatiles eluted after partial refining with each of these bleaching compounds. The results showed that volatile compounds were quantitatively and qualitatively affected by the type of adsorbents used for the elution of olive oil and the smoking points of eluted oils. The most prominent detected volatile compounds were limonene (14.53%), piperitone (10.35%), isopropyl-5-methyl-(2E)-hexenal (8.6%), methyl octadecenoate (6.57%), and citronellyl acetate (5.87%). Both bentonite and resin were superior in decreasing the ratio of volatile compounds compared with other bleaching materials used. Resin immobilized medium was significantly affected (p < 0.05), raising the smoke point. These results highlighted some information regarding the characteristics of volatile compounds that result after the physical elution of olive oil through selected adsorbents.","pmid":"37764219","doi":"10.3390/molecules28186444","url":"https://pubmed.ncbi.nlm.nih.gov/37764219/"},{"id":520,"title":"The Use of Hypochlorous Acid, Test-and-removal, and Cross-fostering to Eradicate Mouse Pathogens in an Animal Facility.","authors":"Shih, Hsin-Yi; Chen, Ying-Chun; Liao, Ching-Fong","year":2023,"date":"2023 Jul 5","journal":"Journal of the American Association for Laboratory Animal Science : JAALAS","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Hypochlorous acid (HOCl), used as a liquid or a fog, has broad antimicrobial and deodorizing effects. Our facility was the first in Taiwan that was built with a system to supply stabilized, biosafe HOCl solution (50 ppm available chlorine concentration, pH 6) into a new animal barrier facility that housed genetically modified mice. The HOCl system creates an extremely clean environment that allows us to raise mice in static, filter-top cages and to handle them on open tables without the need for biologic safety cabinets (BSC). Our animal facility (AF) sometimes receives mice from outside sources that are infected with pathogens, notably murine norovirus (MNV), Helicobacter spp., and trichomonads. We found that our standard operation procedure (SOP) prevented cross-contamination to other mice, including those in adjacent cages. After the removal of infected mice from a room, the remaining mice remained uninfected, without the need for extensive environmental decontamination. Learning this allowed us to use a test-and-removal method to eliminate pathogens. In addition, infected mouse strains that were not commercially available were rederived by using cross-fostering. After finding unexpected infections, we were able to identify all infected mice by widespread screening. We then removed contaminated cages and performed cross-fostering as needed. This approach was able to successfully eliminate murine norovirus, Helicobacter spp., and trichomonads. Over the 12 y in which we managed this AF, we refined our husbandry methods and our approach to the detection and eradication of pathogens by using HOCl fog and solution, the test-and-removal, and cross-fostering.","pmid":"37758477","doi":"10.30802/AALAS-JAALAS-22-000115","url":"https://pubmed.ncbi.nlm.nih.gov/37758477/"},{"id":521,"title":"Microbiological analysis concerning the antibacterial effect of atomized Ionless® hypochlorous acid water in a nursery school environment.","authors":"Miura, Miho; Gotoh, Kenji; Tanamachi, Chiyoko; Katayama, Hideki; Fuketa, Hiroshi; Tomoike, Hideki; Kawamura, Naohisa; Watanabe, Hiroshi; Mihashi, Mutsuko","year":2024,"date":"2024 Feb","journal":"Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"INTRODUCTION: In daycare centers, infants come in close contact with each other, and contact, droplet, and mouth-to-mouth infections may occur owing to sharing of toys. Additional effective disinfection methods should be considered aside from wiping with disinfectants-including alcohol or sodium hypochlorite solution-for environmental disinfection of daycare centers. We aimed to examine the usefulness of hypochlorous acid water atomization in the effective disinfection of the classroom environment and toys at a nursery school. METHODS: Environmental cultures of the nursery and toys were prepared to evaluate the species and bacterial load and to assess the contaminated areas. Staphylococcus aureus petri dishes were placed at high-frequency contact sites, and hypochlorous acid water was atomized to achieve a 0.03-ppm atmospheric chlorine concentration. After the atomization, the amount of S. aureus bacteria on the Petri dish and the changes in bacterial count isolated from the environment and toys were evaluated. RESULTS: Hypochlorous acid water atomization was performed for 5 h to avoid condensation. After a 3-h atomization, ≥99.99% of S. aureus was eliminated on petri dishes; furthermore, a significant disinfection effect was observed on environmental bacteria at least 1 h after atomization. For rubber and textile toys, the significant disinfection effect was observed 1 h after atomization, and for plastic toys, the effect was observed 3 h after atomization. CONCLUSIONS: Hypochlorous acid water atomization is a useful strategy to disinfect nursery school classrooms.","pmid":"37758000","doi":"10.1016/j.jiac.2023.09.024","url":"https://pubmed.ncbi.nlm.nih.gov/37758000/"},{"id":522,"title":"Electrolyzed Hypochlorous Acid (HOCl) Aqueous Solution as Low-Impact and Eco-Friendly Agent for Floor Cleaning and Sanitation.","authors":"Gessi, Alessandro; Formaglio, Paolo; Semeraro, Bruno; Summa, Daniela; Tamisari, Elena; Tamburini, Elena","year":2023,"date":"2023 Sep 5","journal":"International journal of environmental research and public health","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Recently, the use of disinfectants has been becoming a diffused and sometimes indiscriminate practice of paramount importance to limit the spreading of infections. The control of microbial contamination has now been concentrated on the use of traditional agents (i.e., hypochlorite, ozone). However, their prolonged use can cause potential treats, for both human health and environment. Currently, low-impact but effective biocides that are prepared in a way that avoids waste, with a very low toxicity, and safe and easy to handle and store are strongly needed. In this study, produced electrochemically activated hypochlorous (HOCl) acid solutions are investigated and proposed, integrated in a scrubbing machine for floor cleaning treatment. Such an innovative machine has been used for floor cleaning and sanitation in order to evaluate the microbial charge and organic dirt removal capacity of HOCl in comparison with a machine charged with traditional Ecolabel standard detergent. The potential damage on floor materials has also been investigated by means of Scanning Electron Microscope (SEM). A comparative Life Cycle Assessment (LCA) analysis has been carried out for evaluating the sustainability of the use of the HOCl-based and detergent-based machine.","pmid":"37754572","doi":"10.3390/ijerph20186712","url":"https://pubmed.ncbi.nlm.nih.gov/37754572/"},{"id":525,"title":"Fracture strength and hybrid layer formation of endodontically-treated teeth after dental bleaching photoactivated with violet LED.","authors":"de Almeida, Eran Nair Mesquita; Victorino, Keli Regina; Besegato, João Felipe; Costa, Joatan Lucas de Sousa Gomes; Leandrin, Thais Piragine; Vitória, Matheus Sousa; de Andrade, Marcelo Ferrarezi; Kuga, Milton Carlos","year":2023,"date":"2023 Dec","journal":"Photodiagnosis and photodynamic therapy","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVE: To evaluate in vitro the effect of dental bleaching using high concentration hydrogen peroxide (HP) photoactivated with violet LED on fracture strength and hybrid layer formation. METHODS: forty endodontically-treated bovine teeth were randomized into four groups (n = 10): C - Control, HP - 35% hydrogen peroxide, HP-BL - 35% hydrogen peroxide photoactivated with blue LED, HP-VL - 35% hydrogen peroxide photoactivated with violet LED. Three bleaching sessions with an interval of 7 days between them were performed. After 10 days of the last bleaching session, the dental crowns were restored and submitted to the fracture strength test. Five specimens from each group were used to evaluate the hybrid layer formation by scanning electron microscope (SEM) images. One-way ANOVA and Kruskal-Wallis test were used for parametric and non-parametric data, respectively. Significance level of 5% was adopted to all the tests. RESULTS: No differences on fracture strength among the groups were observed (p > 0.05). HP and HP-BL showed alterations on hybrid layer formation compared to C group (p < 0.05), but not for HP-VL (p > 0.05). No differences on hybrid layer formation were observed among HP, HP-VL and HP-BL groups (p > 0.05). CONCLUSION: Dental bleaching, photoactivated or not, did not affect the fracture strength of endodontically-treated teeth. Regardless of the protocol used, hydrogen peroxide altered the hybrid layer formation at some level when the restoration was placed after 10 days of the last bleaching session.","pmid":"37748699","doi":"10.1016/j.pdpdt.2023.103813","url":"https://pubmed.ncbi.nlm.nih.gov/37748699/"},{"id":533,"title":"Antimicrobial Coatings for Medical Textiles via Reactive Organo-Selenium Compounds.","authors":"Hoque, Ejajul; Tran, Phat; Jacobo, Unique; Bergfeld, Nicholas; Acharya, Sanjit; Shamshina, Julia L; Reid, Ted W; Abidi, Noureddine","year":2023,"date":"2023 Aug 31","journal":"Molecules (Basel, Switzerland)","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Bleached and cationized cotton fabrics were chemically modified with reactive organoselenium compounds through the nucleophilic aromatic substitution (S(N)Ar) reaction, which allowed for organo-selenium attachment onto the surface of cotton fabrics via covalent bonds and, in the case of the cationized cotton fabric, additional ionic interactions. The resulting textiles exhibited potent bactericidal activity against S. aureus (99.99% reduction), although only moderate activity was observed against E. coli. Fabrics treated with reactive organo-selenium compounds also exhibited fungicidal activities against C. albicans, and much higher antifungal activity was observed when organo-selenium compounds were applied to the cationized cotton in comparison to the bleached cotton. The treatment was found to be durable against rigorous washing conditions (non-ionic detergent/100 °C). This paper is the first report on a novel approach integrating the reaction of cotton fabrics with an organo-selenium antimicrobial agent. This approach is attractive because it provides a method for imparting antimicrobial properties to cotton fabrics which does not disrupt the traditional production processes of a textile mill.","pmid":"37687210","doi":"10.3390/molecules28176381","url":"https://pubmed.ncbi.nlm.nih.gov/37687210/"},{"id":535,"title":"Cost-per-Response Analysis of Pure Hypochlorous Acid Among Patients with Chronic Venous Leg Ulcers: A Health Economic Analysis.","authors":"Niezgoda, Jeffrey A; Niezgoda, Jonathan A; Niezgoda, Kathleen M; Mallow, Peter J","year":2023,"date":"2023 Nov 1","journal":"Advances in skin & wound care","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"OBJECTIVE: To estimate the total cost-per-wound healing response (CPR) and the per-day CPR of patients with chronic leg ulcers treated with pure hypochlorous acid (pHA) as part of their overall would healing regimen. METHODS: The authors developed a deterministic decision-tree model to estimate the incremental CPR for pHA. The analysis was performed using clinical data from a published single-arm prospective study. The outcome of interest was re-epithelialization at 90 days. Economic data for pHA were based on public prices of pHA per dressing change from the wound care center perspective. The following time points were assessed: 90, 60, and 30 days. Dressing changes occurred every 2.5 days. Sensitivity analysis was performed to gauge the robustness of the results. RESULTS: A total of 31 patients (68% women) with 31 lesions (average age of wound, 29 months; range, 1-240 months) were included in the clinical study. Re-epithelialization occurred in 23 lesions (74%) at 90 days, 17 (55%) at 60 days, and 3 (10%) at 30 days. The total CPRs were $75.69, $68.27, and $193.44, and the per-day CPRs were $0.84, $1.13, and $6.45 at 90, 60, and 30 days, respectively. The sensitivity analysis revealed that CPRs ranged from $0.63 to $1.12 per day at 90 days. CONCLUSIONS: Incorporating pHA into standard wound healing protocols is a minimal added expense and may yield a substantial economic savings of $2,695 at 90 days.","pmid":"37682298","doi":"10.1097/ASW.0000000000000024","url":"https://pubmed.ncbi.nlm.nih.gov/37682298/"},{"id":537,"title":"In vitro activity of hypochlorous acid generating electrochemical bandage against monospecies and dual-species bacterial biofilms.","authors":"Kletzer, Joseph; Raval, Yash S; Mohamed, Abdelrhman; Mandrekar, Jayawant N; Greenwood-Quaintance, Kerryl E; Beyenal, Haluk; Patel, Robin","year":2023,"date":"2023 Sep 5","journal":"Journal of applied microbiology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"AIMS: As antimicrobial resistance is on the rise, treating chronic wound infections is becoming more complex. The presence of biofilms in wound beds contributes to this challenge. Here, the activity of a novel hypochlorous acid (HOCl) producing electrochemical bandage (e-bandage) against monospecies and dual-species bacterial biofilms formed by bacteria commonly found in wound infections was assessed. METHODS AND RESULTS: The system was controlled by a wearable potentiostat powered by a 3V lithium-ion battery and maintaining a constant voltage of + 1.5V Ag/AgCl, allowing continuous generation of HOCl. A total of 19 monospecies and 10 dual-species bacterial biofilms grown on polycarbonate membranes placed on tryptic soy agar (TSA) plates were used as wound biofilm models, with HOCl producing e-bandages placed over the biofilms. Viable cell counts were quantified after e-bandages were continuously polarized for 2, 4, 6, and 12 hours. Time-dependent reductions in colony forming units (CFUs) were observed for all studied isolates. After 12 hours, average CFU reductions of 7.75 ± 1.37 and 7.74 ± 0.60 log10 CFU/cm2 were observed for monospecies and dual-species biofilms, respectively. CONCLUSIONS: HOCl producing e-bandages reduce viable cell counts of in vitro monospecies and dual-species bacterial biofilms in a time-dependent manner in vitro. After 12 hours, >99.999% reduction in cell viability was observed for both monospecies and dual-species biofilms.","pmid":"37667489","doi":"10.1093/jambio/lxad194","url":"https://pubmed.ncbi.nlm.nih.gov/37667489/"},{"id":540,"title":"Hybrid light applied with 37% carbamide peroxide bleaching agent with or without titanium dioxide potentializes color change effectiveness.","authors":"Guedes, Rafaela de Almeida; Carlos, Natália Russo; Turssi, Cecilia Pedroso; França, Fabiana Mantovani Gomes; Vieira-Junior, Waldemir Francisco; Kantovitz, Kamila Rosamilia; Bronze-Uhle, Erika Soares; Lisboa-Filho, Paulo Noronha; Basting, Roberta Tarkany","year":2023,"date":"2023 Dec","journal":"Photodiagnosis and photodynamic therapy","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"BACKGROUND: The effectiveness of dental color change was assessed by incorporating titanium dioxide (TiO(2)) into 37% carbamide peroxide bleaching agent associated with hybrid light. METHODOLOGY: Fifty bovine incisors were selected to receive the bleaching treatment, and separated into five groups (n = 10): 35% hydrogen peroxide (HP) (Whiteness HP, FGM/HP); 37% carbamide peroxide (CP) (Whiteness SuperEndo, FGM/CP); CP + hybrid light (HL) (CP HL); CP + 1% TiO(2) (CP TiO(2)); CP TiO(2) + hybrid light (CP TiO(2) HL). The bleaching gels were applied to the dental surface for 30 min. Hybrid light (Whitening Plus, DMC/infrared laser diodes + blue LEDs +violet LEDs) was applied with 1 min of active light, alternating with 1 min of pause. A spectrophotometer (VITA Easyshade® Advance, Vita) was used to determine the color of the dental elements at baseline and time points after the 1st, 2nd and 3rd bleaching sessions. Color change effectiveness was evaluated using Vita Classical, CIEL*a*b*, WI(D) and ΔE(ab), ΔE(00) and ΔWI(D) parameters. RESULTS: Generalized mixed linear models for repeated measures (α = 5%) showed significant decrease in Vita Classical scores and a* and b* values, as well as an increase in L* and ∆W(ID) values for all the groups. Higher color change values for ΔE(ab) were observed for CP HL and CP TiO(2) HL, while those of ΔE(00) and ΔWI(D) were higher for CP TiO(2) HL at the end of the bleaching treatment. CONCLUSION: Hybrid light applied with TiO(2) incorporated into CP potentiated the effectiveness of the color change in the tooth structure(.)","pmid":"37640206","doi":"10.1016/j.pdpdt.2023.103762","url":"https://pubmed.ncbi.nlm.nih.gov/37640206/"},{"id":546,"title":"Antimicrobial efficacy of chlorine agents against selected oral pathogens.","authors":"Almhöjd, Ulrica Scherdin; Lehrkinder, Anna; Roos-Jansåker, Ann-Marie; Lingström, Peter","year":2023,"date":"2023 Sep","journal":"Clinical oral investigations","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"OBJECTIVES: Method-dependent comparison of antimicrobial agents' efficacy against oral pathogens. MATERIALS AND METHODS: Several sodium hypochlorite solutions (NaOCl)-Perisolv(®), Carisolv(®) and Dakin's solution-were equated with chlorhexidine (CHX) and hydrogen peroxide (H(2)O(2)) against ten oral micro-organisms related to caries and periodontitis using different minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) techniques. Agents were adjusted to the final 70 mmol/L concentration of active chlorine molecule. RESULTS: Apart from H(2)O(2) and the amino acids of Perisolv(®), all the agents revealed an antimicrobial effect. Agar diffusion test ranked CHX (p < 0.05) as the most effective against all ten specimens, followed by the NaOCl of Perisolv(®) and Dakin's solution. Correspondingly, in broth microdilution on agar, CHX was the most effective in eradicating micro-organisms at 0.03 mmol/L compared with 2.2 mmol/L of Dakin's solution. In contrast, the bactericidal concentration of Dakin's solution was the most effective at 0.2 mmol/L, (p < 0.001), followed by Perisolv(®) (2.14 mmol/L), CHX (2.38 mmol/L) and Carisolv(®) (3.33 mmol/L) after 5 and 10 min in broth dilution test. In live/dead analysis, 60-min exposure to a 2-fold concentration of agents resulted in two-log Aggregatibacter actinomycetemcomitans inhibition by CHX (35 mmol/L) whilst Streptococcus mutans was more susceptible, in 0.8 and 8.8 mmol/L, after 10 min to CHX and Dakin's respectively. CONCLUSION: Replacement of CHX with tested hypochlorite agents showed evident potential and promoted rapid antimicrobial effect. CLINICAL RELEVANCE: Effective antimicrobial agents are crucial in controlling pathogen-induced oral infections increasing clinical possibilities to combat oral biofilms. Additionally, CHX substitution with hypochlorite agents could eliminate CHX's adverse effects.","pmid":"37606720","doi":"10.1007/s00784-023-05190-0","url":"https://pubmed.ncbi.nlm.nih.gov/37606720/"},{"id":547,"title":"Fabrication of CdS quantum dots with egg white and application in the assay of hypochlorous acid and myeloperoxidase activity and inhibition.","authors":"Xia, Xiaodong","year":2023,"date":"2023 Aug 31","journal":"Analytical methods : advancing methods and applications","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The myeloperoxidase (MPO)/H(2)O(2)-Cl(-) enzymatic reaction system and its product hypochlorous acid (HOCl) are closely related to many disease processes, and new methods to detect the levels of HOCl and MPO are being focused on. MPO is the only known enzyme for the catalytic production of HOCl in biological systems; therefore, monitoring the HOCl levels is a selective and direct readout of MPO activity. This study reported a simple and efficient fluorescence assay of HOCl and MPO activity and inhibition. Highly fluorescent CdS quantum dots (CdS QDs) were prepared in one pot where NaOH-pretreated egg white served as a stabilizer. These CdS QDs exhibit strong green emission centered at ca. 550 nm and enable rapid and selective fluorescence response to HOCl with a linear detection range of 8.0-250 μM and a limit of detection (LOD) of 2.5 μM. Moreover, the CdS QDs were further applied for sensing MPO based on the fluorescence quenching exerted by its reaction product HOCl. Detection of MPO is accomplished with a linear range from 0.1 to 40 mU mL(-1) (1 U is the MPO concentration for catalysis of 1 micromolar substrate per minute) and a LOD of 0.06 mU mL(-1). The developed synthesis method can be applied to large-scale synthesis of CdS QDs, and the strategy to sense HOCl and MPO activity and inhibition has potential biomedical applications such as clinical diagnosis and drug screening.","pmid":"37591805","doi":"10.1039/d3ay01148h","url":"https://pubmed.ncbi.nlm.nih.gov/37591805/"},{"id":553,"title":"Boronate-Based Oxidant-Responsive Derivatives of Acetaminophen as Proinhibitors of Myeloperoxidase.","authors":"Pierzchała, Karolina; Pięta, Jakub; Pięta, Marlena; Rola, Monika; Zielonka, Jacek; Sikora, Adam; Marcinek, Andrzej; Michalski, Radosław","year":2023,"date":"2023 Aug 21","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase (MPO) is an important component of the human innate immune system and the main source of a strong oxidizing and chlorinating species, hypochlorous acid (HOCl). Inadvertent, misplaced, or excessive generation of HOCl by MPO is associated with multiple human inflammatory diseases. Therefore, there is a considerable interest in the development of MPO inhibitors. Here, we report the synthesis and characterization of a boronobenzyl derivative of acetaminophen (AMBB), which can function as a proinhibitor of MPO and release acetaminophen, the inhibitor of chlorination cycle of MPO, in the presence of inflammatory oxidants, i.e., hydrogen peroxide, hypochlorous acid, or peroxynitrite. We demonstrate that the AMBB proinhibitor undergoes conversion to acetaminophen by all three oxidants, with the involvement of the primary phenolic product intermediate, with relatively long half-life at pH 7.4. The determined rate constants of the reaction of the AMBB proinhibitor with hydrogen peroxide, hypochlorous acid, or peroxynitrite are equal to 1.67, 1.6 × 10(4), and 1.0 × 10(6) M(-1) s(-1), respectively. AMBB showed lower MPO inhibitory activity (IC(50) > 0.3 mM) than acetaminophen (IC(50) = 0.14 mM) toward MPO-dependent HOCl generation. Finally, based on the determined reaction kinetics and the observed inhibitory effects of two plasma components, uric acid and albumin, on the extent of AMBB oxidation by ONOO(-) and HOCl, we conclude that ONOO(-) is the most likely potential activator of AMBB in human plasma.","pmid":"37534491","doi":"10.1021/acs.chemrestox.3c00140","url":"https://pubmed.ncbi.nlm.nih.gov/37534491/"},{"id":554,"title":"0.01% Hypochlorous Acid Treats Aspergillus fumigatus Keratitis in Rats by Reducing Fungal Load and Inhibiting the Inflammatory Response.","authors":"Zhao, Kai; Hu, Fen; Zhang, Zhaowei; Yin, Xiaoyue; Wang, He; Li, Mingxin","year":2023,"date":"2023 Aug 1","journal":"Translational vision science & technology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"PURPOSE: To investigate the antifungal and anti-inflammatory effects of 0.01% hypochlorous acid (HCLO) on rats with Aspergillus fumigatus keratitis. METHODS: The time-kill assay and broth microdilution procedures were used in vitro to demonstrate that 0.01% HCLO was fungicidal and fungistatic. The severity of the disease was evaluated in vivo using a clinical score and slit-lamp photographs. Fungal load, polymorphonuclear neutrophil infiltration, and the production of related proteins were determined using colony plate counting, in vivo confocal microscopy, periodic acid-Schiff staining, fungal fluorescence staining, immunofluorescence staining, myeloperoxidase assay, and Western blotting. RESULT: In vitro, 0.01% HCLO can destroy A. fumigatus spores in 1 minute. The optical density of the 0.01% HCLO group was significantly lower than that of the phosphate-buffered saline control group (P < 0.01), and no visible mycelium was observed using a fluorescence microscope. 0.01% HCLO reduced the severity of A. fumigatus keratitis in rats by decreasing the clinical score, fungal loading (periodic acid-Schiff, plate count, and fungal fluorescence staining), and inhibiting neutrophil infiltration and activity (immunofluorescence staining and myeloperoxidase). Furthermore, the Western blot analysis revealed that 0.01% HCO decreased protein expression levels of tumor necrosis factor-α and IL-1β. CONCLUSIONS: According to our findings, 0.01% HCLO can kill A. fumigatus spores in vitro. It has antifungal and anti-inflammatory effects on A. fumigatus keratitis in rats. It also inhibited A. fumigatus growth; decreased neutrophil infiltration, tumor necrosis factor-α, and IL-1β expression; and provided a potential treatment for fungal keratitis. TRANSLATIONAL RELEVANCE: This study provides a potential treatment for fungal keratitis in the clinic.","pmid":"37531113","doi":"10.1167/tvst.12.8.3","url":"https://pubmed.ncbi.nlm.nih.gov/37531113/"},{"id":557,"title":"GYY4137, a hydrogen sulfide donor, protects against endothelial dysfunction in porcine coronary arteries exposed to myeloperoxidase and hypochlorous acid.","authors":"Harper, Andrew; Chapel, Maike; Hodgson, Grace; Malinowski, Krzysztof; Yates, Imogen; Garle, Michael; Ralevic, Vera","year":2023,"date":"2023 Oct","journal":"Vascular pharmacology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"BACKGROUND AND AIMS: Myeloperoxidase (MPO) and its principal reaction product hypochlorous acid (HOCl) are part of the innate immune response but are also associated with endothelial dysfunction, thought to involve a reduction in nitric oxide (NO) bioavailability. We aimed to investigate the effect of MPO and HOCl on vasorelaxation of coronary arteries and to assess directly the involvement of NO. In addition, we hypothesised that the slow release hydrogen sulfide (H(2)S) donor GYY4137 would salvage coronary artery endothelial function in the presence of MPO and HOCl. METHODS AND RESULTS: Contractility of porcine coronary artery segments was measured using isometric tension recording. Incubation with MPO (50 ng/ml) plus hydrogen peroxide (H(2)O(2)) (30 μM; substrate for MPO) impaired endothelium-dependent vasorelaxation to bradykinin in coronary arteries. HOCl (10-500 μM) also impaired endothelium-dependent relaxations. There was no effect of MPO plus H(2)O(2), or HOCl, on endothelium-independent relaxations to 5'-N-ethylcarboxamidoadenosine and sodium nitroprusside. L-NAME (300 μM), a NO synthase inhibitor, attenuated bradykinin relaxations, leaving L-NAME-resistant relaxations to bradykinin mediated by endothelium-dependent hyperpolarization. In the presence of L-NAME, MPO plus H(2)O(2) largely failed to impair endothelium-dependent relaxations to bradykinin. Similarly, HOCl failed to inhibit endothelium-dependent relaxations to bradykinin in the presence of L-NAME. GYY4137 (1-100 μM) protected endothelium-dependent relaxations to bradykinin from dysfunction caused by MPO plus H(2)O(2), and HOCl, with no effect alone on bradykinin relaxation responses. The specific MPO inhibitor aminobenzoic acid hydrazide (ABAH) (1 and 10 μM) also protected against MPO plus H(2)O(2)-induced endothelial dysfunction (at 10 μM ABAH), but was less potent than GYY4137. CONCLUSIONS: MPO plus H(2)O(2), and HOCl, impair coronary artery endothelium-dependent vasorelaxation via inhibition of NO. GYY4137 protects against endothelial dysfunction in arteries exposed to MPO plus H(2)O(2), and HOCl. H(2)S donors such as GYY4137 are possible therapeutic options to control excessive MPO activity in cardiovascular diseases.","pmid":"37500030","doi":"10.1016/j.vph.2023.107199","url":"https://pubmed.ncbi.nlm.nih.gov/37500030/"},{"id":559,"title":"Evaluation of 0.01% Hypochlorous Acid Eye Drops Combined with Conventional Treatment in the Management of Fungal Corneal Ulcers: Randomized Controlled Trial.","authors":"Wang, He; Yin, Xiaoyue; Zhang, Zhaowei; Wang, Yining; Zhang, Ling; Guo, Jianxin; Li, Mingxin","year":2023,"date":"2023 Oct","journal":"Current eye research","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"PURPOSE: To evaluate the efficacy and safety of hypochlorous acid (HOCI) eye drops in the treatment of fungal keratitis. METHODS: A total of 96 patients (96 eyes) with fungal keratitis were randomly divided into two groups: group Ι (conventional treatment + topical HOCI eye drops); The group II (conventional treatment). According to its severity, those patients were divided into grade Ι or grade II. Use of fungal scraping and culture to identify the type of fungal infection, slit lamp examination, and corneal fluorescein staining to observe regression, and confocal corneal microscopy to assess fungal mycelial changes. The main outcome measures were the success rate, healing time, visual recovery, and complications. The Kaplan-Meier curve method was used to analysis of the survival function of days to cure between the two groups. RESULTS: There were no statistical differences between the two groups in terms of general condition, medical history, and grading. Corneal scraping results showed that all patients had filamentous fungi. For grade Ι patients, all patients were cured, and the patients in Group I showed faster healing speed than that in Group II (t = -3.665, p < .01). For grade II patients, the recovery time (t = -4.121, p < .01) and the disappearance of hypopyon (t = -4.291, p < .01) were significantly faster in the combination group. In grade Ι and II patients, the final visual acuity and the incidence of complications such as corneal neovascularization, cataract, and hyphema showed no differences in both groups. The survival curve showed that the healing rate of ulcers in the combination treatment group was faster than that in the conventional treatment group (χ(2) = 14.332, p = .001). CONCLUSION: HOCI can accelerate the healing of fungal keratitis without obvious complications, indicating a promising future in the field of keratitis treatment.","pmid":"37493085","doi":"10.1080/02713683.2023.2226374","url":"https://pubmed.ncbi.nlm.nih.gov/37493085/"},{"id":560,"title":"Fabrication of a paper-based facile and low-cost microfluidic device and digital imaging technique for point-of-need monitoring of hypochlorite.","authors":"Debnath, Snehasish; Ghosh, Riya; Pragti; Mukhopadhyay, Suman; Baskaran, Kamesh Viswanathan; Chatterjee, Pabitra B","year":2023,"date":"2023 Aug 21","journal":"The Analyst","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Lab-on-a-paper-based devices are promising alternatives to the existing arduous techniques for point-of-need monitoring. The present work reports an instant and facile method to produce a microfluidic paper-based analytical device (μPAD). The fabricated μPAD has been used to detect hypochlorite (OCl(-)) by incorporating newly synthesized chromo-fluorogenic ratiometric probes 1 and 2 into the sample reception zone. The probes showed high selectivity and fast response (<10 s) toward OCl(-) with an excellent linear relationship in the concentration range of 0-100 μM. The concentration-dependent fluorometric change driven by the reaction of 1@μPAD with OCl(-) has been monitored using gel-doc imaging systems, which is unprecedented. Digitizing the intensity of the colour solution with different mathematical models of colour has developed a straightforward method for monitoring OCl(-) without any interference from its competitors. 1@μPAD can detect OCl(-) at ∼10 times lower than the WHO recommended limit. The detection limit of 1@μPAD via a digital camera-based fluorescence technique was found to be better over digital camera-based cuvette assays. Therefore, 1@μPAD has been successfully utilized to monitor OCl(-) in actual environmental water samples with portability, ease of use, and sensitivity. The analytical RSD was found to be ≤3% based on fluorimetric detection using 1@μPAD. The chemodosimetric reaction between OCl(-) and the probe was evidenced by UV-vis and fluorescence spectroscopy, (1)H NMR, and ESI-MS. The rapid response time, biocompatibility, low cytotoxicity, 100% aqueous solubility, ratiometric feature, and exclusive OCl(-) selectivity over other competitive ROS/RNS successfully lead to the application of the probes for bioimaging of exogenous as well as endogenous OCl(-) in normal cells (HEK293) and cancerous cells (HeLa).","pmid":"37486009","doi":"10.1039/d3an00533j","url":"https://pubmed.ncbi.nlm.nih.gov/37486009/"},{"id":562,"title":"Kinetics and mechanism of triclocarban degradation by the chlorination process: Theoretical calculation and experimental verification.","authors":"Peng, Tao; Xu, Chao; Yang, Bin; Gu, Feng-Long; Ying, Guang-Guo","year":2023,"date":"2023 Oct","journal":"Chemosphere","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Triclocarban (TCC) is an antimicrobial agent commonly used in many household and personal care products, and has been found persistent in the aquatic environment. Here we elucidate the kinetics and mechanism of TCC degradation during chlorination process by density functional theory (DFT) calculation and experimental verification. Results showed that hypochlorous acid (HOCl)/hypochlorite (OCl(-)) reacted with TCC via Cl-substitution, OH-substitution and C-N bond cleavage pathways. The reactivity of OCl(-) (2.80 × 10(-7) M(-1) s(-1)) with TCC was extremely low and HOCl (1.96 M(-1) s(-1)) played the dominant role in TCC chlorination process. The N site of TCC was the most reactive site for chlorination. The second-order rate constants, which are determined using density functional theory (DFT) (k(TCC-chlorine)(C), 1.96 M(-1) s(-1)), can be separated into reaction rate constants related to the reactions of HOCl and OCl(-) with different isomers of TCC (TCC2 and TCC6). The obtained k(TCC-chlorine)(C) was consistent with the experimental determined second-order rate constant (k(TCC-chlorine)(E), 3.70 M(-1) s(-1)) in chlorination process. Eight transformation products (TP348, TP382, TP127, TP161, TP195, TP330, TP204, and TP296) were experimentally detected for chlorination of TCC, which could also be predicted by DFT calculation. Explicit water molecules participated in the chlorination reaction by transmitting the proton and connecting with TCC, HOCl/OCl(-) and other H(2)O molecules, and obviously reduced the energy barrier of chlorination.","pmid":"37467851","doi":"10.1016/j.chemosphere.2023.139551","url":"https://pubmed.ncbi.nlm.nih.gov/37467851/"},{"id":567,"title":"New dual-responsive fluorescent sensor for hypochlorite and cyanide sensing and its imaging application in live cells and zebrafish.","authors":"Ma, Wenwen; Chen, Ruiming; Hu, Tingting; Xing, Shu; Zhou, Guanglian; Qin, Xiaoxu; Ren, Huijun; Zhang, Zhengyang; Chen, Jianbin; Niu, Qingfen","year":2023,"date":"2023 Dec 1","journal":"Talanta","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Excessive levels of cyanide (CN(-)) and hypochlorite (ClO(-)) anions are the significant threats to the human health and the environment. Thus, great efforts have been to design and synthesize molecular sensors for the simple, instantaneous and efficient detecting environmentally and biologically important anions. Currently, developing a single molecular sensor for multi-analyte sensing is still a challenging task. In our present work, we developed a new molecular sensor (3TM) based on oligothiophene and Meldrum's acid units for detecting cyanide and hypochlorite anions in biological, environmental and food samples. The detecting ability of 3TM has been examined to various testing substances containing amino acids, reactive oxygen species, cations and anions, showing its high selectivity, excellent sensitivity, short response time (ClO(-): 30 s, CN(-): 100 s), and broad pH working range (4-10). The detection limits were calculated as 4.2 nM for ClO(-) in DMSO/H(2)O (1/8, v/v) solution and 6.5 nM for CN(-) in DMSO/H(2)O (1/99, v/v) solution. Sensor 3TM displayed sharp turn-on fluorescence increasement (555 nm, 435 nm) and sensitive fluorescence color changes caused by CN(-)/ClO(-), which is ascribed to the nucleophilic addition and oxidation of ethylenic linkage by cyanide and hypochlorite, respectively. Moreover, sensor 3TM was applied for hypochlorite and cyanide detecting in real-world water, food samples and bio-imaging in live cells and zebrafish. To our knowledge, the developed 3TM sensor is the seventh single-molecular sensor for simultaneous and discriminative detecting hypochlorite and cyanide in food, biological and aqueous environments using two distinct sensing modes.","pmid":"37418961","doi":"10.1016/j.talanta.2023.124910","url":"https://pubmed.ncbi.nlm.nih.gov/37418961/"},{"id":570,"title":"The effect of a preparation containing glycocholic acid on the biocidal efficacy of sodium hypochlorite in a biofilm laboratory model.","authors":"Haddad, Yoseif; Chan, Wing Chuan; Ha, William Nguyen; Conde, Antonio; Estevez, Roberto; Lopez, Alejandro Peña; Gates, Georgia Charlotte; Rossi-Fedele, Giampiero","year":2023,"date":"2023 Dec","journal":"Australian endodontic journal : the journal of the Australian Society of Endodontology Inc","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"This study assessed the antimicrobial effect of sodium hypochlorite (NaOCl) mixtures combined with Keratobacter (KB) using an engineered biofilm root canal model. Clinical and reagent grade NaOCl were mixed with KB (9:1-vol/vol) to assess pH values over 1 min to select the ideal solution with a pH just below the pKa of hypochlorous acid. The samples were randomly divided into five groups: 1% and 4% NaOCl reagents, a mixture of NaOCl:KB using 1% and 4% NaOCl reagents and distilled water. Outcome measures were colony-forming units (CFUs/mL) and positive/negative cultures. No significant differences were observed in the pairwise comparisons between 1%, 4% NaOCl and 4% NaOCl+KB for the outcome CFUs/mL. Only 4% NaOCl presented with negative cultures in all samples, whereas 1% NaOCl and 4% NaOCl+KB had similar results (54% vs. 40%). The addition of KB has a limited effect on the antimicrobial efficacy of 4% NaOCl in this laboratory model.","pmid":"37403810","doi":"10.1111/aej.12771","url":"https://pubmed.ncbi.nlm.nih.gov/37403810/"},{"id":575,"title":"Effects of experimental bleaching gels containing co-doped titanium dioxide and niobium pentoxide combined with violet light.","authors":"Matos, Iago César Ribeiro Teles; Kury, Matheus; de Melo, Priscila Borges Gobbo; de Souza, Leticia Vasconcelos Silva; Esteban Florez, Fernando Luis; Cavalli, Vanessa","year":2023,"date":"2023 Aug","journal":"Clinical oral investigations","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"OBJECTIVES: The objective of the study is to evaluate the bleaching potential of 6% hydrogen peroxide (6% HP) gels containing NF_TiO(2) or Nb(2)O(5) irradiated with a violet LED light and the effects on enamel mineral content and surface morphology. METHODS: Particles were synthesized, and experimental gels were chemically analyzed by preliminary and accelerated stability tests, pH, and HP decomposition rate. Bovine enamel blocks were treated with 6% HP gels containing (n = 10): 5% NF_TiO(2), 5% Nb(2)O(5), 2.5% NF_TiO(2) + 2.5% Nb(2)O(5) or without particles (6% HP), irradiated or not with LED, and the control was treated with 35% HP. Color (∆E(00)) and whitening index (∆WID) variations, surface microhardness (SH), average roughness (∆Ra), Ca-P concentration (EDS), and enamel morphology (SEM) were assessed. Bleaching was performed in 3 sessions of 30 min and 7-day intervals. Data were submitted to two- (pH, decomposition rate, ∆E(00), and ∆WID) or three-way ANOVA and Bonferroni (SH), Kruskal-Wallis (∆Ra), and Dunnet tests (α = 0.05). RESULTS: No changes in the gel's color, odor, or translucency were observed. The pH (6 to 6.5) remained stable over time, and light irradiation boosted the HP decomposition rate. NF_TiO(2) and Nb(2)O(5)-containing gels displayed higher ∆E(00) and ΔWID when light-irradiated (p < 0.05). Nb(2)O(5) and Nb(2)O(5) + NF_TiO(2) decreased enamel SH (p < 0.05), but no SH changes were found among groups (p > 0.05). No differences among groups were noted in ∆Ra, Ca-P content, and enamel morphology after treatments (p > 0.05). CONCLUSION: Experimental light-irradiated 6% HP gels containing NF_TiO(2) or Nb(2)O(5) were chemically stable and exhibited bleaching potential comparable with 35% HP. CLINICAL RELEVANCE: Low-concentrated HP gels containing NF_TiO(2) or Nb(2)O(5) and light-irradiated stand as a possible alternative to in-office bleaching.","pmid":"37369816","doi":"10.1007/s00784-023-05113-z","url":"https://pubmed.ncbi.nlm.nih.gov/37369816/"},{"id":578,"title":"Substrate-dependent metabolomic signatures of myeloperoxidase activity in airway epithelial cells: Implications for early cystic fibrosis lung disease.","authors":"Kim, Susan O; Shapiro, Joseph P; Cottrill, Kirsten A; Collins, Genoah L; Shanthikumar, Shivanthan; Rao, Padma; Ranganathan, Sarath; Stick, Stephen M; Orr, Michael L; Fitzpatrick, Anne M; Go, Young-Mi; Jones, Dean P; Tirouvanziam, Rabindra M; Chandler, Joshua D","year":2023,"date":"2023 Sep","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Myeloperoxidase (MPO) is released by neutrophils in inflamed tissues. MPO oxidizes chloride, bromide, and thiocyanate to produce hypochlorous acid (HOCl), hypobromous acid (HOBr), and hypothiocyanous acid (HOSCN), respectively. These oxidants are toxic to pathogens, but may also react with host cells to elicit biological activity and potential toxicity. In cystic fibrosis (CF) and related diseases, increased neutrophil inflammation leads to increased airway MPO and airway epithelial cell (AEC) exposure to its oxidants. In this study, we investigated how equal dose-rate exposures of MPO-derived oxidants differentially impact the metabolome of human AECs (BEAS-2B cells). We utilized enzymatic oxidant production with rate-limiting glucose oxidase (GOX) coupled to MPO, and chloride, bromide (Br(-)), or thiocyanate (SCN(-)) as substrates. AECs exposed to GOX/MPO/SCN(-) (favoring HOSCN) were viable after 24 h, while exposure to GOX/MPO (favoring HOCl) or GOX/MPO/Br(-) (favoring HOBr) developed cytotoxicity after 6 h. Cell glutathione and peroxiredoxin-3 oxidation were insufficient to explain these differences. However, untargeted metabolomics revealed GOX/MPO and GOX/MPO/Br(-) diverged significantly from GOX/MPO/SCN(-) for dozens of metabolites. We noted methionine sulfoxide and dehydromethionine were significantly increased in GOX/MPO- or GOX/MPO/Br(-)-treated cells, and analyzed them as potential biomarkers of lung damage in bronchoalveolar lavage fluid from 5-year-olds with CF (n = 27). Both metabolites were associated with increasing bronchiectasis, neutrophils, and MPO activity. This suggests MPO production of HOCl and/or HOBr may contribute to inflammatory lung damage in early CF. In summary, our in vitro model enabled unbiased identification of exposure-specific metabolite products which may serve as biomarkers of lung damage in vivo. Continued research with this exposure model may yield additional oxidant-specific biomarkers and reveal explicit mechanisms of oxidant byproduct formation and cellular redox signaling.","pmid":"37356776","doi":"10.1016/j.freeradbiomed.2023.06.021","url":"https://pubmed.ncbi.nlm.nih.gov/37356776/"},{"id":580,"title":"Electrochemically synthesized green fluorescent carbon dots for quantitation of hypochlorite and carbendazim.","authors":"Lo, Kuan-Min; Lin, Yu-Shen; Liou, Je-Wen; Chiu, Tai-Chia; Hu, Cho-Chun","year":2023,"date":"2023 Jun 15","journal":"Journal of food and drug analysis","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Green emission carbon dots (CDs) electrochemically prepared from 2,6-pyridinedicarboxylic acid and o-phenyl-enediamine were applied separately for the quantitation of hypochlorite and carbendazim. The characteristic and optical properties of the CDs were studied through fluorescence, UV-vis absorption, X-ray photoelectron spectroscopy, and transmission electron microscopy. The synthesized CDs were mainly 0.8-2.2 nm in size, with an average size of 1.5 nm. The CDs exhibited green luminescence centered at 520 nm when excited by 420 nm light. The green emission of the CDs is quenched after the addition of hypochlorite, mainly through the redox reaction between hypochlorite and hydroxyl groups on the CDs surface. Furthermore, the hypochlorite-induced fluorescence quenched can be prevented in the presence of carbendazim. The sensing approaches exhibit good linear ranges of 1-50 μM and 0.05-5 μM for hypochlorite and carbendazim, respectively, with low detection limits of 0.096 and 0.005 μM, respectively. Practicalities of the luminescent probes were separately validated by the quantitation of the two analytes in real sample matrix with recoveries ranging from 96.3 to 108.9% and the relative standard deviation values below 5.51%. Our results show the potential of the sensitive, selective, and simple CD probe for water and food quality control.","pmid":"37335167","doi":"10.38212/2224-6614.3445","url":"https://pubmed.ncbi.nlm.nih.gov/37335167/"},{"id":582,"title":"Immersion of debrided diabetic foot ulcer tissue in electrochemically generated pH neutral hypochlorous acid significantly reduces the microbial bioburden: whole-genome sequencing of Staphylococcus aureus, the most prevalent species recovered.","authors":"Grealy, L; Wilson, P; Gillen, C; Duffy, É; Healy, M-L; Daly, B; Polyzois, I; Van Harten, M; Dougall, A; Brennan, G I; Coleman, D C; McManus, B A","year":2023,"date":"2023 Aug","journal":"The Journal of hospital infection","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Diabetic foot ulcer infections (DFUIs) are the leading cause of lower-limb amputations, mediated predominantly by Staphylococcus aureus. pH-neutral electrochemically generated hypochlorous acid (anolyte) is a non-toxic, microbiocidal agent with significant potential for wound disinfection. AIMS: To investigate both the effectiveness of anolyte for microbial bioburden reduction in debrided ulcer tissues and the population of resident S. aureus. METHODS: Fifty-one debrided tissues from 30 people with type II diabetes were aliquoted by wet weight and immersed in 1- or 10-mL volumes of anolyte (200 parts per million) or saline for 3 min. Microbial loads recovered were determined in colony forming units/g (cfu/g) of tissue following aerobic, anaerobic and staphylococcal-selective culture. Bacterial species were identified and 50 S. aureus isolates from 30 tissues underwent whole-genome sequencing (WGS). FINDINGS: The ulcers were predominantly superficial, lacking signs of infection (39/51, 76.5%). Of the 42/51 saline-treated tissues yielding ≥10(5) cfu/g, a microbial threshold reported to impede wound-healing, only 4/42 (9.5%) were clinically diagnosed DFUIs. Microbial loads from anolyte-treated tissues were significantly lower than saline-treated tissues using 1 mL (1065-fold, 2.0 log) and 10 mL (8216-fold, 2.1 log) immersion volumes (P<0.0005). S. aureus was the predominant species recovered (44/51, 86.3%) and 50 isolates underwent WGS. All were meticillin susceptible and comprised 12 sequence types (STs), predominantly ST1, ST5 and ST15. Whole-genome multi-locus sequence typing identified three clusters of closely related isolates from 10 patients indicating inter-patient transmission. CONCLUSIONS: Short immersions of debrided ulcer tissue in anolyte significantly reduced microbial bioburden: a potential novel DFUI treatment.","pmid":"37308064","doi":"10.1016/j.jhin.2023.06.006","url":"https://pubmed.ncbi.nlm.nih.gov/37308064/"},{"id":586,"title":"HOCl Rapidly Kills Corona, Flu, and Herpes to Prevent Aerosol Spread.","authors":"Guan, H; Nuth, M; Weiss, S R; Fausto, A; Liu, Y; Koo, H; Wolff, M S; Ricciardi, R P","year":2023,"date":"2023 Aug","journal":"Journal of dental research","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"The COVID-19 pandemic has escalated the risk of SARS-CoV-2 transmission in the dental practice, especially as droplet-aerosol particles are generated by high-speed instruments. This has heightened awareness of other orally transmitted viruses, including influenza and herpes simplex virus 1 (HSV1), which are capable of threatening life and impairing health. While current disinfection procedures commonly use surface wipe-downs to reduce viral transmission, they are not fully effective. Consequently, this provides the opportunity for a spectrum of emitted viruses to reside airborne for hours and upon surfaces for days. The objective of this study was to develop an experimental platform to identify a safe and effective virucide with the ability to rapidly destroy oral viruses transported within droplets and aerosols. Our test method employed mixing viruses and virucides in a fine-mist bottle atomizer to mimic the generation of oral droplet-aerosols. The results revealed that human betacoronavirus OC43 (related to SARS-CoV-2), human influenza virus (H1N1), and HSV1 from atomizer-produced droplet-aerosols were each fully destroyed by only 100 ppm of hypochlorous acid (HOCl) within 30 s, which was the shortest time point of exposure to the virucide. Importantly, 100 ppm HOCl introduced into the oral cavity is known to be safe for humans. In conclusion, this frontline approach establishes the potential of using 100 ppm HOCl in waterlines to continuously irrigate the oral cavity during dental procedures to expeditiously destroy harmful viruses transmitted within aerosols and droplets to protect practitioners, staff, and other patients.","pmid":"37246843","doi":"10.1177/00220345231169434","url":"https://pubmed.ncbi.nlm.nih.gov/37246843/"},{"id":592,"title":"Microstructural effect of different concentrations of hydrogen peroxide photoactivated with LED/laser.","authors":"Manzoli, Tatiane Miranda; Costa, Joatan Lucas de Sousa Gomes; Besegato, João Felipe; Zaniboni, Joissi Ferrari; Galvani, Lucas David; Dantas, Andréa Abi Rached; Kuga, Milton Carlos","year":2023,"date":"2023 Jun","journal":"Photodiagnosis and photodynamic therapy","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"BACKGROUND: The use of different concentrations of hydrogen peroxide (HP) photoactivated with LED/laser sources is common however, their influence on tooth structure is not yet fully elucidated. This study aimed to evaluate the pH, microhardness and surface roughness of different bleaching protocols photoactivated with LED/laser. METHODS: Forty bovine incisors were sectioned (7 × 7 × 2 mm) and randomized into four groups for analysis of pH (n = 5), microhardness and roughness (n = 10): HP35, HP6_L, HP15_L, HP35_L. The pH analysis was performed in the initial and final minute of the bleaching protocol. Microhardness and roughness were evaluated before and 7 days after the last bleaching session. Results were obtained from two-way ANOVA for repeated measures and Bonferroni post-test at a significance level of 5%. RESULTS: HP6_L showed higher pH and greater stability between the initial and final evaluations, while the other groups showed similar pH with reduced values in the intragroup evaluation. No differences between groups in microhardness and roughness evaluations were observed. CONCLUSIONS: Although HP6_L showed higher alkalinity and pH stability, none of the protocols reduced the microhardness and surface roughness of bovine enamel.","pmid":"37201771","doi":"10.1016/j.pdpdt.2023.103613","url":"https://pubmed.ncbi.nlm.nih.gov/37201771/"},{"id":596,"title":"Carbocyanine-Based Optical Sensor Array for the Discrimination of Proteins and Rennet Samples Using Hypochlorite Oxidation.","authors":"Shik, Anna V; Stepanova, Irina A; Doroshenko, Irina A; Podrugina, Tatyana A; Beklemishev, Mikhail K","year":2023,"date":"2023 Apr 26","journal":"Sensors (Basel, Switzerland)","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Optical sensor arrays are widely used in obtaining fingerprints of samples, allowing for solutions of recognition and identification problems. An approach to extending the functionality of the sensor arrays is using a kinetic factor by conducting indicator reactions that proceed at measurable rates. In this study, we propose a method for the discrimination of proteins based on their oxidation by sodium hypochlorite with the formation of the products, which, in turn, feature oxidation properties. As reducing agents to visualize these products, carbocyanine dyes IR-783 and Cy5.5-COOH are added to the reaction mixture at pH 5.3, and different spectral characteristics are registered every several minutes (absorbance in the visible region and fluorescence under excitation by UV (254 and 365 nm) and red light). The intensities of the photographic images of the 96-well plate are processed by principal component analysis (PCA) and linear discriminant analysis (LDA). Six model proteins (bovine and human serum albumins, γ-globulin, lysozyme, pepsin, and proteinase K) and 10 rennet samples (mixtures of chymosin and pepsin from different manufacturers) are recognized by the proposed method. The method is rapid and simple and uses only commercially available reagents.","pmid":"37177503","doi":"10.3390/s23094299","url":"https://pubmed.ncbi.nlm.nih.gov/37177503/"},{"id":597,"title":"Point-of-Care and Dual-Response Detection of Hydrazine/Hypochlorite-Based on a Smart Hydrogel Sensor and Applications in Information Security and Bioimaging.","authors":"Du, Man; Zhang, Yue; Xu, Zhice; Dong, Zhipeng; Zhao, Shuchun; Du, Hongxia; Zhao, Hua","year":2023,"date":"2023 May 5","journal":"Molecules (Basel, Switzerland)","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"A novel dual-response fluorescence probe (XBT-CN) was developed by using a fluorescence priming strategy for quantitative monitoring and visualization of hydrazine (N(2)H(4)) and hypochlorite (ClO(-)). With the addition of N(2)H(4)/ClO(-), the cleavage reaction of C=C bond initiated by N(2)H(4)/ClO(-) was transformed into corresponding hydrazone and aldehyde derivatives, inducing the probe XBT-CN appeared a fluorescence \"off-on\" response, which was verified by DFT calculation. HRMS spectra were also conducted to confirm the sensitive mechanism of XBT-CN to N(2)H(4) and ClO(-). The probe XBT-CN had an obvious fluorescence response to N(2)H(4) and ClO(-), which caused a significant color change in unprotected eyes. In addition, the detection limits of XBT-CN for N(2)H(4) and ClO(-) were 27 nM and 34 nM, respectively. Interference tests showed that other competitive analytes could hardly interfere with the detection of N(2)H(4) and ClO(-) in a complex environment. In order to realize the point-of-care detection of N(2)H(4) and ClO(-), an XBT-CN@hydrogel test kit combined with a portable smartphone was developed. Furthermore, the portable test kit has been applied to the detection of N(2)H(4) and ClO(-) in a real-world environment and food samples, and a series of good results have been achieved. Attractively, we demonstrated that XBT-CN@hydrogel was successfully applied as an encryption ink in the field of information security. Finally, the probe can also be used to monitor and distinguish N(2)H(4) and ClO(-) in living cells, exhibiting excellent biocompatibility and low cytotoxicity.","pmid":"37175308","doi":"10.3390/molecules28093896","url":"https://pubmed.ncbi.nlm.nih.gov/37175308/"},{"id":598,"title":"The bleaching effect of office bleaching agents containing S-PRG filler evaluated by pH value and electron spin resonance.","authors":"Akabane, Kodai; Hiraishi, Noriko; Shimojima, Mika; Nassar, Mohannad; Qi, Feng; Otsuki, Masayuki; Shimada, Yasushi","year":2023,"date":"2023 Jul","journal":"Clinical oral investigations","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"OBJECTIVES: Surface reaction-type pre-reacted glass-ionomer (S-PRG) filler releases six types of ions with a neutralizing ability. This study evaluated the effect of S-PRG filler incorporation in an H(2)O(2)-based bleaching material on the bleaching efficacy, pH, and reaction state. MATERIALS AND METHODS: The experimental bleaching material was formulated by the addition of 5% or 10% S-PRG fillers to the powder part. The stained bovine teeth were treated with the prepared bleaching paste. Commission internationale de l'éclairage (CIE) L*a*b* color space values were recorded before and after bleaching, and the color difference (ΔE) and whiteness index (WI(D)) were calculated. Moreover, the used bleaching formulations were assessed for their pH values and reaction state by evaluating the oxidation state of manganese (Mn(+2)) using electron spin resonance (ESR). RESULTS: The results of ΔE and WI(D) showed that the addition of S-PRG filler increased the bleaching effect, but there was no significant difference between the groups with 5% and 10% S-PRG filler. A significant increase in pH in S-PRG filler groups (5% pH 6.7, 10% pH 6.8) was found compared to the 0% group (pH 4.8). ESR measurements showed that the signal emitted from Mn(+2) decreased over time. The S-PRG filler groups showed a significantly higher reduction in Mn(+2) compared to the 0% group, with no significant difference between the 5% and 10% S-PRG groups. CONCLUSIONS: S-PRG filler addition resulted in improved bleaching efficacy, higher reaction rate, and pH values that are close to neutral. CLINICAL RELEVANCE: S-PRG filler addition may be effective on the bleaching outcome of H(2)O(2)-based materials.","pmid":"37133698","doi":"10.1007/s00784-023-05031-0","url":"https://pubmed.ncbi.nlm.nih.gov/37133698/"},{"id":600,"title":"Highly water dispersible collagen/polyaniline nanocomposites with strong adhesion for electrochromic films with enhanced cycling stability.","authors":"Zhao, Yinghui; Liu, Wentao; Bai, Xue; Huang, Wenhuan; Gu, Yingchun; Chen, Sheng; Lan, Jianwu","year":2023,"date":"2023 Jun 30","journal":"International journal of biological macromolecules","category":"Materials & industrial applications","evidence":"Journal article / other","relevance":"Medium","abstract":"Electrochromic materials have attracted extensive attention recently due to their versatile applications in smart windows, displays, antiglare rearview mirrors, and so on. Herein we report a new electrochromic composite prepared from collagen and polyaniline (PANI) through a self-assembly assisted co-precipitation method. The introduction of hydrophilic collagen macromolecules into PANI nanoparticles makes the collagen/PANI (C/PANI) nanocomposite obtain excellent dispersibility in water, which provides good environmental-friendly solution processability. Furthermore, the C/PANI nanocomposite exhibits excellent film-forming properties and adhesion to the ITO glass matrix. The resulting electrochromic film of the C/PANI nanocomposite displays significantly improved cycling stability compared with the pure PANI film after 500 coloring-bleaching cycles. On the other hand, the composite films also exhibit yellow, green and blue polychromatic properties at different applied voltages and high average transmittance at the bleaching state. The C/PANI electrochromic material illustrates scaling potential for the application of electrochromic devices.","pmid":"37119893","doi":"10.1016/j.ijbiomac.2023.124657","url":"https://pubmed.ncbi.nlm.nih.gov/37119893/"},{"id":601,"title":"Chemical oxygen demand and tannin/lignin removal from paper mill wastewater by electrocoagulation combined with peroxide and hypochlorite treatments.","authors":"Caglak, Abdulkadir; Sari-Erkan, Hanife; Onkal Engin, Guleda","year":2024,"date":"2024 Jun","journal":"Environmental technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The present investigation sought to assess the practicality of utilizing a combined pre-treatment approach comprising electrocoagulation, peroxide, and hypochlorite treatments for the removal of chemical oxygen demand (COD) and tannin/lignin from paper mill wastewater. The study aimed to optimize the operating parameters with a view to maximizing the removal efficiencies while minimizing energy consumption. A pair of iron electrodes were used as anode and cathode in the study, and the main operating parameters were determined as initial pH, applied current, treatment time and oxidant dosage/COD ratio. Response surface methodology (RSM) was used to evaluate the effect of these parameters on COD and tannin/lignin removals. The primary findings of the investigation indicated that the integration of electrocoagulation with peroxide and hypochlorite treatments exhibited efficacy in removing COD, tannin/lignin, colour, phenol, and turbidity from paper mill wastewater. The optimized conditions resulted in COD removal efficiencies of 48.13 ± 2.2% and 29.53 ± 1.4% for EC with H(2)O(2) and Ca(OCl)(2), respectively. Tannin/lignin removal efficiencies were 92.59 ± 3.6% and 94.09 ± 1.8% for EC-H(2)O(2) and EC-Ca(OCl)(2), respectively. The specific energy consumption (SEC) values showed that EC-Ca(OCl)(2) required 7 times more energy than EC-H(2)O(2) for removing 1 kg COD. The principal deduction drawn from the study was that EC-H(2)O(2) pre-treatment demonstrated superior COD removal efficiency and lower energy consumption, while EC-Ca(OCl)(2) pre-treatment exhibited greater efficiency in removing toxic and recalcitrant pollutants. In future studies, it would be useful to conduct research to increase COD removal efficiency in addition to tannin/lignin removal in EC-Ca(OCl)(2) process.","pmid":"37105959","doi":"10.1080/09593330.2023.2206529","url":"https://pubmed.ncbi.nlm.nih.gov/37105959/"},{"id":605,"title":"Bleach Emissions Interact Substantially with Surgical and KN95 Mask Surfaces.","authors":"Bhattacharyya, Nirvan; Tang, Mengjia; Blomdahl, Daniel C; Jahn, Leif G; Abue, Pearl; Allen, David T; Corsi, Richard L; Novoselac, Atila; Misztal, Pawel K; Hildebrandt Ruiz, Lea","year":2023,"date":"2023 Apr 25","journal":"Environmental science & technology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Mask wearing and bleach disinfectants became commonplace during the COVID-19 pandemic. Bleach generates toxic species including hypochlorous acid (HOCl), chlorine (Cl(2)), and chloramines. Their reaction with organic species can generate additional toxic compounds. To understand interactions between masks and bleach disinfection, bleach was injected into a ventilated chamber containing a manikin with a breathing system and wearing a surgical or KN95 mask. Concentrations inside the chamber and behind the mask were measured by a chemical ionization mass spectrometer (CIMS) and a Vocus proton transfer reaction mass spectrometer (Vocus PTRMS). HOCl, Cl(2), and chloramines were observed during disinfection and concentrations inside the chamber are 2-20 times greater than those behind the mask, driven by losses to the mask surface. After bleach injection, many species decay more slowly behind the mask by a factor of 0.5-0.7 as they desorb or form on the mask. Mass transfer modeling confirms the transition of the mask from a sink during disinfection to a source persisting >4 h after disinfection. Humidifying the mask increases reactive formation of chloramines, likely related to uptake of ammonia and HOCl. These experiments indicate that masks are a source of chemical exposure after cleaning events occur.","pmid":"37061949","doi":"10.1021/acs.est.2c07937","url":"https://pubmed.ncbi.nlm.nih.gov/37061949/"},{"id":606,"title":"Influence of violet LED and fluoride-containing carbamide peroxide bleaching gels on early-stage eroded/abraded teeth.","authors":"Palandi, Samuel da Silva; Kury, Matheus; Cavalli, Vanessa","year":2023,"date":"2023 Jun","journal":"Photodiagnosis and photodynamic therapy","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"PURPOSE: This study evaluated enamel with early-stage erosion/abrasion following bleaching with 20% and 45% carbamide peroxide (CP) gels containing fluoride (F) and irradiated with violet LED (LED). METHODS: Enamel blocks were immersed in 1% citric acid (5 min) and artificial saliva (120 min) three times to produce early-stage enamel erosion. Simulated toothbrushing was performed only after the first saliva immersion, to provoke enamel abrasion. The erosive/abraded enamel samples were submitted to (n=10): LED/CP20, CP20, LED/CP20_F, CP20_F, LED/CP45, CP45, LED/CP45_F, CP45_F, LED, and control (without treatment). The pH of the gels was assessed, and color (ΔE(00)) and whiteness index (ΔWI(D)) changes were calculated after cycling (T(1)), and 7 days from bleaching (T(2)). Enamel surface roughness average (Ra) and Knoop microhardness (kg/mm(2), %SHR) were evaluated at baseline (T(0)) at T(1) and T(2.) Scanning electron microscopy evaluated the enamel surface morphology at T(2). RESULTS: The gels' pH was neutral and CP20 and CP45 exhibited no differences in ΔE(00) and ΔWI(D) (p>0.05) but LED increased these parameters for CP20_F and CP45. Erosion/abrasion significantly decreased mean kg/mm(2), and the LED group was the only one not increasing microhardness after bleaching (p>0.05). None of the groups fully recovered the initial microhardness. All groups exhibited %SHR similar to the control (p>0.05) and the increase in Ra was detected only after erosion/abrasion. CP20_F groups exhibited a more preserved enamel morphology. CONCLUSION: Light irradiation combined with low-concentrated CP gel promoted a bleaching effect comparable to the high-concentrated CP. The bleaching protocols did not adversely impact the surface of early-stage eroded/abraded enamel.","pmid":"37059164","doi":"10.1016/j.pdpdt.2023.103568","url":"https://pubmed.ncbi.nlm.nih.gov/37059164/"},{"id":607,"title":"Visualizing stimulus-responsive dual-ligand fluorescent probes for hypochlorite: A novel strategy for real application in tap water.","authors":"Han, Jianhong; Wang, Yuting; Ren, Zehua; Zhang, Lianke; Hu, Shuting; Li, Yumei; Liu, Pai","year":2023,"date":"2023 Jun","journal":"Luminescence : the journal of biological and chemical luminescence","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"As an effective ingredient of disinfectants, ClO(-) inevitably remains in water, which induces potential health hazards such as lung damage and kidney disease. In this study, we synthesized stimulus-responsive dual-ligand luminol-Tb-GMP coordination polymer nanoparticles (luminol-Tb-GMP CPNPs) as highly selective fluorescent probes for the real-time and visual detection of ClO(-) . CPNPs consist of Tb(3+) , a nuclear metal, that coordinates with GMP and luminol, an auxiliary ligand. GMP can be oxidized by ClO(-) and damage its structure, resulting in fluorescence quenching of CPNPs. The two-ligand CPNPs sensor has a rapid fluorescent response, significant fluorescent color change, and high sensitivity, with a linear range of 2-18 μM and a detection limit of 0.14 μM. It has been successfully used to detect ClO(-) in tap water, fountain water, and drinking water. Simultaneously, the portable filter paper strip was prepared to expand the range of applications outside the laboratory, which will provide a promising application for the real-time and semiquantitative analysis of ClO(-) .","pmid":"37057382","doi":"10.1002/bio.4500","url":"https://pubmed.ncbi.nlm.nih.gov/37057382/"},{"id":609,"title":"Hypochlorous acid-activated near-infrared fluorescent probe for in vivo/exogenous detection and dairy toxicity evaluation.","authors":"Wang, Xiao; Wang, Xuechuan; Lu, Qiangqiang; Sun, Xiaolong; Han, Qingxing","year":2023,"date":"2023 Aug 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Oxidative stress has been reported to be closely associated with many diseases, and an excessive overdose of hypochlorite (ClO(-)) can also induce stress-related diseases. In this study, we designed and synthesized a NIR probe, named W-1a based on computational analysis of DCM (4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran) derivatives for specific detection of ClO(-). The probe exhibited dual fluorescence and colorimetric sensing with a response time of <1 min and a detection limit of 0.15 μM. Additionally, the probe was successfully applied for fluorescence imaging of ClO(-) at the cellular level and ebrafish endogenous/exogenous ClO(-) assay and dairy toxicity assessment. Thus, we present a potential method for developing an efficient and reliable detection of ClO(-) in early stage using near-infrared dyes.","pmid":"37037175","doi":"10.1016/j.saa.2023.122661","url":"https://pubmed.ncbi.nlm.nih.gov/37037175/"},{"id":611,"title":"Can all highly concentrated in-office bleaching gels be used as a single-application?","authors":"da Silva, Karine Letícia; Favoreto, Michael Willian; Centenaro, Gabrielle Gomes; Bernardi, Laís Giacomini; Borges, Christiane Philippini Ferreira; Reis, Alessandra; Loguercio, Alessandro D","year":2023,"date":"2023 Jul","journal":"Clinical oral investigations","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVE: This in vitro study aims to evaluate of hydrogen peroxide (HP) diffusion into the pulp chamber, bleaching efficacy (BE), and pH stability (pH) of single-application high concentrated in-office bleaching gels. MATERIALS AND METHODS: Eighty-eight healthy premolars were randomly into eleven groups (n = 8) according to the in-office dental bleaching: DSP White Clinic 35% calcium (DW), Nano White 35% (NW), Opalescence XTra Boost 40% (OB), Pola Office + 37.5% (PO), Potenza Bianco Pro SS 38% (PB), Total Blanc 35% (TB), Total Blanc One-Step 35% (TO), Whiteness Automixx 35% (WA), Whiteness Automixx Plus 35% (WP), and Whiteness HP Blue 35% (WB). A group not exposed to bleaching agents was the control group (CG). All bleaching agents were applied in one session with a single application. After the bleaching procedure, the concentration of HP diffusion (μg/mL) into the pulp chamber was assessed using UV-Vis spectrophotometry. The BE (ΔE(ab) and ΔE(00)) was evaluated before and 1 week after the bleaching procedure using a digital spectrophotometer. The pH of each bleaching gel was evaluated by digital pHmeter. The one-way ANOVA and Tukey's was used for a statistical analysis (α = 0.05). RESULTS: The concentration of HP diffusion into the pulp chamber was higher in all in-office bleaching gels when compared to CG (p < 0.0000001). However, there are a significant difference between them (p = 0.0001). A significant BE was observed in all in-office bleaching gels (p < 0.0001 for ΔE(ab) and ΔE(00)), with a significant difference between them (p < 0.0001). PO, OB, TB, WP, and WB showed a higher BE when compared to DW, PB, and WA (p < 0.0001). Most bleaching gels were slightly acidic or alkaline during the total application time, while DW, PB, TB, and WA showed a high acidic behavior after 30 min of application. CONCLUSIONS: A single application was able to produce a bleaching efficacy. However, usually, gels with slightly acidic or alkaline pH during the application time reduces the HP diffusion into the pulp chamber. CLINICAL RELEVANCE: The single-application of bleaching gels with slightly acidic or alkaline and stable pH decreased the penetration of hydrogen peroxide into the pulp chamber in in-office bleaching and maintained the bleaching efficacy.","pmid":"37017758","doi":"10.1007/s00784-023-04980-w","url":"https://pubmed.ncbi.nlm.nih.gov/37017758/"},{"id":612,"title":"Comparison of antibiofilm activity of low-concentrated hypochlorites vs polyhexanide-containing antiseptic.","authors":"Paleczny, Justyna; Junka, Adam Felix; Krzyżek, Paweł; Czajkowska, Joanna; Kramer, Axel; Benkhai, Hicham; Żyfka-Zagrodzińska, Ewa; Bartoszewicz, Marzenna","year":2023,"date":"2023","journal":"Frontiers in cellular and infection microbiology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Chronic wound infection is highly associated with morbidity and endangers the patient's life. Therefore, wound care products must have a potent antimicrobial and biofilm-eradicating effect. In this work, the antimicrobial/antibiofilm activity of two low-concentrated chlorine-based and releasing solutions was investigated on a total of 78 strains of methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, using the cohesive spectrum of in vitro settings, including microtiter plate models, biofilm-oriented antiseptic test, cellulose-based biofilm model, biofilm bioreactors and Bioflux model. The antiseptic containing polyhexamethylene biguanide was used in the character of usability control of performed tests. The results obtained by static biofilm models indicate that low-concentrated chlorine-based and releasing solutions display none to moderate antibiofilm activity, while data obtained by means of the Bioflux model, providing flow conditions, indicate the moderate antibiofilm activity of substances compared with the polyhexanide antiseptic. Considering in vitro data presented in this manuscript, the earlier reported favorable clinical results of low-concentrated hypochlorites should be considered rather an effect of their rinsing activity combined with low cytotoxicity but not the antimicrobial effect per se. For the treatment of heavily biofilm-infected wounds, polyhexanide should be considered the agent of choice because of its higher efficacy against pathogenic biofilms.","pmid":"37009512","doi":"10.3389/fcimb.2023.1119188","url":"https://pubmed.ncbi.nlm.nih.gov/37009512/"},{"id":617,"title":"Antiseptic efficacy of two mouth rinses in the oral cavity to identify a suitable rinsing solution in radiation- or chemotherapy induced mucositis.","authors":"Zwicker, Paula; Freitag, Marcus; Heidel, Florian H; Kocher, Thomas; Kramer, Axel","year":2023,"date":"2023 Mar 26","journal":"BMC oral health","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"OBJECTIVES: Oral mucositis caused by intensive cancer chemotherapy or radiotherapy frequently results in pronounced damage of the oral mucosa leading to painful oral hygiene. To support oral care, antimicrobial effective mouth rinses may be used. Thus, the efficacy of a hypochlorite-based mouth rinse (Granudacyn®), assumed to be highly biocompatible because of the compounds being part of the natural pathogen defense, as possible antiseptic agent in case of oral mucositis was compared to that of an octenidine based antiseptic mouth rinse (Octenidol® md). MATERIALS AND METHODS: The study was conducted as monocentric, controlled, randomized, blind cross over comparative study on 20 volunteers. As a proof of principle, we performed the study on orally healthy subjects and not cancer patients. The efficacy was determined as reduction of colony forming units (cfu) on buccal mucosa as well as in saliva. After mouth rinsing for 30 s, samples were taken after 1 min, 15 min, 30 and 60 min. The lg-reduction was calculated as difference between lg-values of cfu pre- and post-treatment. RESULTS: Both antiseptic mouth rinses induced a significant reduction of cfu on buccal mucosa and in saliva 1 min after mouth rinsing. The effect persisted up to 60 min. The octenidine based rinse was significantly superior to the hypochlorite-based rinse up to the last sample 60 min after rinsing. However, the known cytotoxicity of octenidine argues against its application. CONCLUSION: Within the limits of this study, due to its antiseptic efficacy, the hypochlorite-based rinse Granudacyn® can be regarded appropriate to support the oral hygiene in patients with a sensitive oral mucosa during an aggressive cancer chemotherapy and radiation treatment in case of oral mucositis.","pmid":"36966298","doi":"10.1186/s12903-023-02884-5","url":"https://pubmed.ncbi.nlm.nih.gov/36966298/"},{"id":618,"title":"Rapid and ratiometric fluorescent detection of hypochlorite by glutathione functionalized molybdenum disulfide quantum dots.","authors":"Zhong, Yaping; Guo, Lijuan; Zou, Yibiao; Chen, Yu; Lu, Zhentan; Wang, Dong","year":2023,"date":"2023 Jul 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"We proposed a rapid and ratiometric fluorescent detection method for hypochlorite by glutathione functionalized molybdenum disulfide quantum dots (G-MoS(2) QDs). The G-MoS(2) QDs were obtained through a hydrothermal method and the maximum fluorescence intensity was obtained at 430 nm under excitation of 360 nm. The fluorescence of G-MoS(2) QDs at 430 nm can be weakened by curcumin through the inner filter effect, meanwhile the fluorescence of curcumin at 540 nm appeared. Hypochlorite can fast oxidize curcumin and weaken the inner filter effect, thus the fluorescence of curcumin at 540 nm decreased and the fluorescence of G-MoS(2) QDs at 430 nm increased. This process takes only 30 s at room temperature. This is the rationale behind our rapid ratiometric fluorescent detection model for hypochlorite. Two linear detection ranges for hypochlorite are obtained with concentration from 1 to 20 μM and 20 to 30 μM, the limit of detection (LOD) was 11.5 nM. The standard spike recovery tests on milk and tap water samples showed satisfactory results, which extended the application of G-MoS(2) QDs in the field of ratiometric fluorescence detection assays.","pmid":"36963221","doi":"10.1016/j.saa.2023.122649","url":"https://pubmed.ncbi.nlm.nih.gov/36963221/"},{"id":620,"title":"Synergistic effect of two formulations of hypochlorous acid in the treatment of 346 chronic ulcers.","authors":"Herruzo, Rafael; Fondo Alvarez, Erika; Herruzo, Irene; Santiso Casanova, Emma; Cerame Perez, Silvia","year":2023,"date":"2023 May-Jun","journal":"Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Our objective was to assess the efficacy of two successive applications of hypochlorous acid, first as a liquid and then as a gel because liquid hypochlorous acid is effective but has little residual effect, while the gel form has more residual power, and compare it with that of other products. An experimental non-randomised study was carried out, treating 346 chronic ulcers in 220 patients. The antiseptic treatment has been divided into 'hypochlorous acid' (Clortech), 'hypochlorous acid liquid + gel' (Clortech + Microdacyn60(R) -hydrogel) and 'Others' (Prontosan or Chlorhexidine or Microdacyn60(R) -hydrogel). Bivariate and multivariate studies analysed the characteristics of the patients and their ulcers, including size, symptoms, signs, treatments received and their duration, and so on. The ulcers were complicated, of long evolution, and most had a vascular origin. On average, antiseptic treatment lasted 14 weeks. At the time of their discharge, or last treatment in the clinics, 59% of the ulcers had healed completely, 9.5% worsened, and 6.9% had become infected during this period. In the bivariate and multivariate studies, we took as reference the 'others' treatments that showed no significant differences in healing time or infection rates compared with liquid hypochlorous acid 100-500 mg/L alone. However, hypochlorous acid liquid + gel showed a synergistic effect, with a higher probability of achieving complete healing (four times) and a lower probability of infection (a fifth), compared to the 'other' antiseptics. In conclusion, a synergistic effect was found with the successive application of hypochlorous acid in liquid followed by gel, an effect that increased healing probability and decreased the risk of the ulcer becoming infected.","pmid":"36951216","doi":"10.1111/wrr.13079","url":"https://pubmed.ncbi.nlm.nih.gov/36951216/"},{"id":623,"title":"Influence of thermal cycles and disinfection on the roughness, microhardness and color of PETG/TPU and PMMA.","authors":"Neto, Clóvis Lamartine De Moraes Melo; Bernardi, Bruno Simão; Dekon, Stefan Fiuza De Carvalho; Santos, Daniela Micheline Dos; Goiato, Marcelo Coelho","year":2023,"date":"2023 Jan-Jun","journal":"Polimery w medycynie","category":"Materials & industrial applications","evidence":"Journal article / other","relevance":"Medium","abstract":"BACKGROUND: Occlusal splints can protect teeth during bruxism, preventing tooth wear, as well as during sports activities, shielding them from impacts. OBJECTIVES: To verify the influence of thermal cycles and disinfection on the roughness, microhardness and color of polyethylene terephthalate glycol/thermoplastic polyurethane (PETG/TPU) and poly(methyl methacrylate) (PMMA). MATERIAL AND METHODS: Thirty-six PETG/TPU samples and 36 PMMA samples were prepared (ø10 mm × 3 mm). Six groups were created according to the material and the disinfection method used (n = 12 each): PETG/TPU (glister), PETG/TPU (hypochlorite), PETG/TPU (soap), PMMA (glister), PMMA (hypochlorite), and PMMA (soap). Roughness, Knoop microhardness and color evaluations were performed before the experiments (T1), after thermocycling (T2) and after disinfection (T3). Three-way repeated measures analysis of variance (ANOVA) and Tukey's test were used for statistical evaluations. RESULTS: For roughness and color, ANOVA showed statistical significance based on the interaction between thermal cycling, material and disinfectant factors. In terms of Knoop microhardness, ANOVA showed statistical significance based on the interaction between thermal cycling and material factors. CONCLUSIONS: Roughness results were clinically acceptable in all groups at all time points, except the PETG/TPU and PMMA groups disinfected with hypochlorite. Microhardness significantly increased for both materials after thermal cycling, and at all time points, the microhardness of PMMA was significantly higher than that of PETG/TPU. After thermal cycling, the color changes were clinically unacceptable in all groups.","pmid":"36929643","doi":"10.17219/pim/159350","url":"https://pubmed.ncbi.nlm.nih.gov/36929643/"},{"id":624,"title":"Curcumin from Curcuma longa Linn. (Family: Zingiberaceae) attenuates hypochlorous acid-induced cytotoxicity and oxidative damage to human red blood cells.","authors":"Tantry, Irfan Qadir; Ali, Asif; Mahmood, Riaz","year":2023,"date":"2023 Jun","journal":"Toxicology in vitro : an international journal published in association with BIBRA","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Hypochlorous acid (HOCl) is a major oxidant produced by activated neutrophils via the myeloperoxidase catalyzed reaction. The production of HOCl eliminates a wide range of pathogens. However, HOCl can also cause significant oxidative damage in cells and tissues where it is generated. The protective effect of curcumin was studied on HOCl-induced oxidative damage to human red blood cells (RBC). Isolated RBC were incubated with HOCl at 37 °C in absence or presence of different concentrations of curcumin. Hemolysates were prepared and assayed for various biochemical parameters. Treatment of RBC with HOCl alone increased hemolysis, protein carbonyls, heme degradation and chloramines as compared to untreated control cells. This was accompanied by reduction in glutathione level, total sulfhydryls and free amino groups. HOCl also lowered the activities of major antioxidant enzymes and diminished the antioxidant power of RBC. Pre-treatment of RBC with different concentrations of curcumin resulted in concentration-dependent attenuation in all these parameters while curcumin alone had no significant effect. Scanning electron microscopy showed that curcumin prevented HOCl-induced morphological changes in RBC and restored their normal biconcave shape. Thus curcumin can be used as a chemoprotective agent to mitigate HOCl-induced oxidative damage to cells. These results also explain the beneficial effects of curcumin against Helicobacter pylori induced stomach ulcers, caused by excessive production of HOCl at the site of bacterial infection.","pmid":"36924976","doi":"10.1016/j.tiv.2023.105583","url":"https://pubmed.ncbi.nlm.nih.gov/36924976/"},{"id":625,"title":"In-vitro evaluation of the effectiveness of polyphenols based strawberry extracts for dental bleaching.","authors":"Kohli, Shivani; Bhatia, Shekhar; Banavar, Spoorthi Ravi; Al-Haddad, Afaf; Kandasamy, Murugesh; Qasim, Syed Saad Bin; Kit-Kay, Mak; Pichika, Mallikarjuna Rao; Daood, Umer","year":2023,"date":"2023 Mar 13","journal":"Scientific reports","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"To formulate a dental bleaching agent with strawberry extract that has potent bleaching properties and antimicrobial efficacy. Enamel specimens (3 × 3 × 2 mm(3)) were prepared. Quaternary Ammonium Silane (CaC2 enriched) was homogenized with fresh strawberries: Group 1: supernatant strawberry (10 g) extract < Group 2: supernatant strawberry (10 g) extract + 15%HA (Hydroxyapatite) < Group 3: supernatant strawberry (10 g) extract + 15% (HA-2%k21) < Group 4: supernatant strawberry (20 g) extract only (20 g strawberries) < Group 5: supernatant strawberry (20 g) extract + 15% HA < Group 6: supernatant strawberry (20 g) extract + 15% (HA-2%K21) < Group 7: In-office Opalescence Boost 35%. Single-colony lactobacillus was examined using confocal microscopy identifying bacterial growth and inhibition in presence of bleaching agents using 300 µL aliquot of each bacterial culture. Images were analysed by illuminating with a 488 nm argon/helium laser beam. Colour difference (∆E00) was calculated using an Excel spreadsheet implementation of the CIEDE2000 colour difference formula and colour change measured between after staining and after bleaching. Scanning electron microscope was used to image specimens. Raman spectra were collected, and enamel slices were used for STEM/TEM analysis. HPLC was used for strawberry extract analysis. Nano-indentation was performed and X-ray photoelectron spectroscopy. Antioxidant activity was determined along with molecular simulation. hDPSCs were expanded for Alamar Blue Analysis and SEM. Mean colour change was significantly reduced in group 1 compared to other groups (p < 0.05). CLSM showed detrimental effects of different strawberry extracts on bioflms, especially with antimicrobial (p < 0.05). Groups 1, 2 and 3 showed flatter/irregular surfaces with condensation of anti-microbial in group 3. In strawberry specimens, bands predominate at 960 cm(-1). HPLC determined the strawberry extracts content. Molecular simulation verified interaction between calcium and polyphenol components. XPS peak-fitted high-resolution corresponding results of Ca2p(3/2) and Ca2p(1/2) for all k21 groups. Combination of 10 g strawberry extract supernatant and 15% (hydroxyapatite 2%k21) improved the whiteness and provided additional antimicrobial potential. The novel strawberry extract and antimicrobial based dental formulation had immediate bleaching effect without promoting significant changes in enamel morphology.","pmid":"36914760","doi":"10.1038/s41598-023-31125-6","url":"https://pubmed.ncbi.nlm.nih.gov/36914760/"},{"id":626,"title":"Hypervirulent R20291 Clostridioides difficile spores show disinfection resilience to sodium hypochlorite despite structural changes.","authors":"Malyshev, Dmitry; Jones, Imogen Anne; McKracken, Matthew; Öberg, Rasmus; Harper, Glenn M; Joshi, Lovleen Tina; Andersson, Magnus","year":2023,"date":"2023 Mar 6","journal":"BMC microbiology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Clostridioides difficile is a spore forming bacterial species and the major causative agent of nosocomial gastrointestinal infections. C. difficile spores are highly resilient to disinfection methods and to prevent infection, common cleaning protocols use sodium hypochlorite solutions to decontaminate hospital surfaces and equipment. However, there is a balance between minimising the use of harmful chemicals to the environment and patients as well as the need to eliminate spores, which can have varying resistance properties between strains. In this work, we employ TEM imaging and Raman spectroscopy to analyse changes in spore physiology in response to sodium hypochlorite. We characterize different C. difficile clinical isolates and assess the chemical's impact on spores' biochemical composition. Changes in the biochemical composition can, in turn, change spores' vibrational spectroscopic fingerprints, which can impact the possibility of detecting spores in a hospital using Raman based methods. RESULTS: We found that the isolates show significantly different susceptibility to hypochlorite, with the R20291 strain, in particular, showing less than 1 log reduction in viability for a 0.5% hypochlorite treatment, far below typically reported values for C. difficile. While TEM and Raman spectra analysis of hypochlorite-treated spores revealed that some hypochlorite-exposed spores remained intact and not distinguishable from controls, most spores showed structural changes. These changes were prominent in B. thuringiensis spores than C. difficile spores. CONCLUSION: This study highlights the ability of certain C. difficile spores to survive practical disinfection exposure and the related changes in spore Raman spectra that can be seen after exposure. These findings are important to consider when designing practical disinfection protocols and vibrational-based detection methods to avoid a false-positive response when screening decontaminated areas.","pmid":"36879193","doi":"10.1186/s12866-023-02787-z","url":"https://pubmed.ncbi.nlm.nih.gov/36879193/"},{"id":627,"title":"Lignin and spent bleaching clay into mono-aromatic hydrocarbons by a cascade dual catalytic pyrolysis system: Critical role of spent bleaching clay.","authors":"Wan, Zhen; Li, Zhihe; Yi, Weiming; Zhang, Andong; Li, Guo; Wang, Shaoqing","year":2023,"date":"2023 May 1","journal":"International journal of biological macromolecules","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"In the present study, a cascade dual catalytic system was used for the co-pyrolysis of lignin with spent bleaching clay (SBC) to efficiently produce mono-aromatic hydrocarbon (MAHs). The cascade dual catalytic system is composed of calcined SBC (CSBC) and HZSM-5. In this system, SBC not only acts as a hydrogen donor and catalyst in the co-pyrolysis process, but is also used as a primary catalyst in the cascade dual catalytic system after recycling the pyrolysis residues. The effects of different influencing factors (i.e., temperature, CSBC-to-HZSM-5 ratio, and raw materials-to-catalyst ratio) on the system were explored. It was observed that, when the temperature was 550 °C, the CSBC-to-HZSM-5 ratio was 1:1, and when the raw materials-to-catalyst ratio was 1:2, the highest bio-oil yield was 21.35 wt%. The relative MAHs content in bio-oil was 73.34 %, whereas the relative polycyclic aromatic hydrocarbons (PAHs) content was 23.01 %. Meanwhile, the introduction of CSBC inhibited the generation of graphite-like coke as indicated by HZSM-5. This study realizes the full resource utilization of spent bleaching clay and reveals the environmental hazards caused by spent bleaching clay and lignin waste.","pmid":"36870660","doi":"10.1016/j.ijbiomac.2023.123879","url":"https://pubmed.ncbi.nlm.nih.gov/36870660/"},{"id":633,"title":"Hypochlorous acid inactivates oral pathogens and a SARS-CoV-2-surrogate.","authors":"Tazawa, Kento; Jadhav, Rutuja; Azuma, Mariane Maffei; Fenno, J Christopher; McDonald, Neville J; Sasaki, Hajime","year":2023,"date":"2023 Feb 18","journal":"BMC oral health","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: Droplets and aerosols produced during dental procedures are a risk factor for microbial and viral transmission. Unlike sodium hypochlorite, hypochlorous acid (HOCl) is nontoxic to tissues but still exhibits broad microbicidal effect. HOCl solution may be applicable as a supplement to water and/or mouthwash. This study aims to evaluate the effectiveness of HOCl solution on common human oral pathogens and a SARS-CoV-2 surrogate MHV A59 virus, considering the dental practice environment. METHODS: HOCl was generated by electrolysis of 3% hydrochloric acid. The effect of HOCl on human oral pathogens, Fusobacterium nucleatum, Prevotella intermedia, Streptococcus intermedius, Parvimonas micra, and MHV A59 virus was studied from four perspectives: concentration; volume; presence of saliva; and storage. HOCl solution in different conditions was utilized in bactericidal and virucidal assays, and the minimum inhibitory volume ratio that is required to completely inhibit the pathogens was determined. RESULTS: In the absence of saliva, the minimum inhibitory volume ratio of freshly prepared HOCl solution (45-60 ppm) was 4:1 for bacterial suspensions and 6:1 for viral suspensions. The presence of saliva increased the minimum inhibitory volume ratio to 8:1 and 7:1 for bacteria and viruses, respectively. Applying a higher concentration of HOCl solution (220 or 330 ppm) did not lead to a significant decrease in the minimum inhibitory volume ratio against S. intermedius and P. micra. The minimum inhibitory volume ratio increases in applications of HOCl solution via the dental unit water line. One week of storage of HOCl solution degraded HOCl and increased the minimum growth inhibition volume ratio. CONCLUSIONS: HOCl solution (45-60 ppm) is still effective against oral pathogens and SAR-CoV-2 surrogate viruses even in the presence of saliva and after passing through the dental unit water line. This study indicates that the HOCl solution can be used as therapeutic water or mouthwash and may ultimately reduce the risk of airborne infection in dental practice.","pmid":"36803460","doi":"10.1186/s12903-023-02820-7","url":"https://pubmed.ncbi.nlm.nih.gov/36803460/"},{"id":634,"title":"The microstructure and thermal properties of pulsed electric field pretreated oxidized starch.","authors":"Li, Ying; Wang, Jin-Hua; Wang, Er-Chun; Tang, Zhong-Sheng; Han, Yu; Luo, Xiu-Er; Zeng, Xin-An; Woo, Meng-Wai; Han, Zhong","year":2023,"date":"2023 Apr 30","journal":"International journal of biological macromolecules","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The structure and thermal properties of pulsed electric field (PEF) assisted sodium hypochlorite oxidized starch were investigated. The carboxyl content of the oxidized starch was increased by 25 % when compared with the traditional oxidation method. Dents and cracks were evident on the surface of the PEF-pretreated starch. Compared with native starch, the peak gelatinization temperature (T(p)) of PEF-assisted oxidized starch (POS) was reduced by 10.3 °C, while that of the oxidized starch without PEF treatment (NOS) was only reduced by 7.4 °C. In addition, PEF treatment further reduces the viscosity and improve the thermal stability of the starch slurry. Therefore, PEF treatment combined with hypochlorite oxidation is an effective method to prepare oxidized starch. PEF showed great potential in expanding starch modification, to promote a wider application of oxidized starch in the paper, the textile and the food industry.","pmid":"36801303","doi":"10.1016/j.ijbiomac.2023.123721","url":"https://pubmed.ncbi.nlm.nih.gov/36801303/"},{"id":638,"title":"Efficient microwave-assisted mineralization of oxytetracycline driven by persulfate and hypochlorite over Cu-biochar catalyst.","authors":"Zhang, Qiaozhi; Sun, Yuqing; Xu, Weijian; Cao, Yang; Wu, Chunfei; Wang, Chi-Hwa; Tsang, Daniel C W","year":2023,"date":"2023 Mar","journal":"Bioresource technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Microwave (MW)-assisted catalytic degradation of organic pollutants draws increasing attention owing to its high efficiency in wastewater treatment. This work developed Cu-loaded biochar (CuBC) catalysts for time-efficient mineralization of refractory and high-concentration oxytetracycline (OTC). With only 1 min at 80 °C, Na(2)S(2)O(8) achieved 100% total organic carbon (TOC) removal over the Cu5BC, while NaClO mineralized 73.3% TOC over the metal-free BC, in contrast to a relatively low mineralization efficiency (< 35%) achieved by H(2)O(2). The high efficiency in MW-assisted oxidation systems could be ascribed to reactive oxidizing species ((•)SO(4)(-) or (•)ClO), which otherwise were barely detectable in a conventional heating system. The interactions between CuBC and MW were revealed by correlating the physiochemical characteristics to the MW absorption ability. The proposed catalytic systems can contribute to the development of a high-throughput and low-carbon wastewater treatment technology.","pmid":"36731614","doi":"10.1016/j.biortech.2023.128698","url":"https://pubmed.ncbi.nlm.nih.gov/36731614/"},{"id":640,"title":"Surface Inactivation of a SARS-CoV-2 Surrogate with Hypochlorous Acid is Impacted by Surface Type, Contact Time, Inoculum Matrix, and Concentration.","authors":"Hamilton, Allyson N; Chandran, Sahaana; Baker, Christopher A; Gibson, Kristen E","year":2023,"date":"2023 Jun","journal":"Food and environmental virology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Indirect contact with contaminated surfaces is a potential transmission route for COVID-19. Therefore, it is necessary to investigate convenient and inexpensive surface sanitization methods, such as HOCl, against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 surrogate, Phi6 (~ 7 log PFU/mL), was prepared in artificial saliva and tripartite matrices, spot inoculated on coupons of either stainless steel or vinyl, and allowed to dry. The coupons were sprayed with either 500 ppm or 1000 ppm HOCl, and remained on the surface for 0 s (control), 5 s, 30 s, or 60 s. Samples were enumerated via the double agar overlay assay. Statistical analysis was completed in R using a generalized linear model with Quasipoisson error approximations. Time, concentration, surface type, and inoculum matrix were all significant contributors to log reduction at P = 0.05. Significant three-way interactions were observed for 1000 ppm, vinyl, and 60 s (P = 0.03) and 1000 ppm, tripartite, and 60 s (P = 0.0121). A significant two-way interaction between vinyl and 60 s was also observed (P = 0.0168). Overall, increased HOCl concentration and exposure time led to increased Phi6 reduction. Notably, the highest estimated mean log reduction was 3.31 (95% CI 3.14, 3.49) for stainless steel at 60 s and 1000 ppm HOCl in artificial saliva, indicating that this method of sanitization may not adequately reduce enveloped viruses to below infective thresholds.","pmid":"36680664","doi":"10.1007/s12560-023-09549-0","url":"https://pubmed.ncbi.nlm.nih.gov/36680664/"},{"id":645,"title":"In vitro effectiveness of different dental bleaching protocols using violet LED.","authors":"Bachiega-Silva, Bruno; Mayer-Santos, Eric; Jurema, Ana Luiza Barbosa; Caneppele, Taciana Marco Ferraz; Brugnera-Junior, Aldo; de Freitas, Patrícia Moreira","year":2023,"date":"2023 Jun","journal":"Photodiagnosis and photodynamic therapy","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"PURPOSE: There has been growing demand for dental bleaching worldwide, however, despite being effective, hydrogen peroxide (HP) can negatively affect the dental structure. Thus, new techniques, such as violet LED light have emerged and need to be studied. The aim of this study was to analyze and compare the effectiveness of violet LED light alone or combined with 35% HP gel. METHODS: Six different tooth bleaching techniques (n = 10) were performed in intrinsically pigmented bovine teeth: G1 - 35% HP (1x/week for 4 weeks, 45 min of gel application); G2 - 35% HP (1x/week for 4 weeks, 15 min of gel application); G3 - violet LED (1x/week for 4 weeks); G4 - violet LED (2x/week for 2 weeks); G5 - violet LED (4x/week for 1 week); G6 - Violet LED + 35% HP (hybrid technique, 1x/week for 4 weeks, 15 min of gel application). Specimens were submitted to color evaluation at predetermined times using Konica Minolta® spectrophotometer, and the surface morphology (n = 3) was qualitatively analyzed by Scanning Electron Microscope (SEM). Data of the color change test were analyzed considering a 5% level of significance. RESULTS: There was significant difference in color (p <0.05) for all groups after bleaching protocols. SEM analysis revealed that the greatest change in surface occurred in Group G1, with demineralization of the dental enamel. When considering the same time interval, there were no statistical differences for axis L*, but differences were shown for axis a* (G2, G3, G4 ≥ G1, G5 ≥ G6) and b* (G1, G2, G3, G4, G5 > G6). Regarding the comparison of ΔE00 between groups, results showed statistical difference between groups, with G1 ≥ G2, G5, G6 ≥ G3, G4. CONCLUSION: Bleaching protocols with less time (15 min) or no exposure to 35% HP (violet LED, 4x/week) could promote bleaching results as those obtained by the conventional technique using 35% HP for 45 min, with no enamel surface changes, showing to be a promising alternative to tooth bleaching.","pmid":"36640856","doi":"10.1016/j.pdpdt.2022.103245","url":"https://pubmed.ncbi.nlm.nih.gov/36640856/"},{"id":648,"title":"A dual-responsive fluorescent turn-on sensor for sensitively detecting and bioimaging of hydrazine and hypochlorite in biofluids, live-cells, and plants.","authors":"Chen, Ruiming; Hu, Tingting; Xing, Shu; Wei, Tao; Chen, Jianbin; Li, Tianduo; Niu, Qingfen; Zhang, Zhengyang; Ren, Huijun; Qin, Xiaoxu","year":2023,"date":"2023 Jan 25","journal":"Analytica chimica acta","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hydrazine (N(2)H(4)) and hypochlorite (ClO(-)) are extremely harmful to the public health, so it is vitally necessary to detect them in living system. Herein, we developed a new phenthiazine-thiobarbituric acid based dual-analyte responsive fluorescent sensor PT for visually distinguishing and detecting N(2)H(4) and ClO(-). PT underwent N(2)H(4)/ClO(-)-induced CC breakage, achieving olive-drab/brilliant green fluorescence lighting-up response towards N(2)H(4)/ClO(-) with superb specifity, ultra-sensitivity (detection limit: 15.4 nM for N(2)H(4), 13.7 nM for ClO(-)), and ultra-fast response (N(2)H(4): <15 s, ClO(-): <20 s). The mechanisms for sensing N(2)H(4) and ClO(-) were investigated with support of spectral measurements and DFT investigation. Sensor based paper-strip/silica-gel device was developed for in-field supervision and on-site monitoring of gaseous and aqueous N(2)H(4) and ClO(-) solution. In addition, the PT was also applied for quantitatively detecting N(2)H(4) and ClO(-) in soil, food, plants and bio-fluids. Moreover, PT was utilized to visualize exogenous N(2)H(4) and ClO(-) in living plants and live-cells, demonstrating this sensor utilized as a powerful tool to detect N(2)H(4) and ClO(-) in biological fields.","pmid":"36628730","doi":"10.1016/j.aca.2022.340735","url":"https://pubmed.ncbi.nlm.nih.gov/36628730/"},{"id":652,"title":"Superoxide: The enigmatic chemical chameleon in neutrophil biology.","authors":"Kettle, Anthony J; Ashby, Louisa V; Winterbourn, Christine C; Dickerhof, Nina","year":2023,"date":"2023 Mar","journal":"Immunological reviews","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"The burst of superoxide produced when neutrophils phagocytose bacteria is the defining biochemical feature of these abundant immune cells. But 50 years since this discovery, the vital role superoxide plays in host defense has yet to be defined. Superoxide is neither bactericidal nor is it just a source of hydrogen peroxide. This simple free radical does, however, have remarkable chemical dexterity. Depending on its environment and reaction partners, superoxide can act as an oxidant, a reductant, a nucleophile, or an enzyme substrate. We outline the evidence that inside phagosomes where neutrophils trap, kill, and digest bacteria, superoxide will react preferentially with the enzyme myeloperoxidase, not the bacterium. By acting as a cofactor, superoxide will sustain hypochlorous acid production by myeloperoxidase. As a substrate, superoxide may give rise to other forms of reactive oxygen. We contend that these interactions hold the key to understanding the precise role superoxide plays in neutrophil biology. State-of-the-art techniques in mass spectrometry, oxidant-specific fluorescent probes, and microscopy focused on individual phagosomes are needed to identify bactericidal mechanisms driven by superoxide. This work will undoubtably lead to fascinating discoveries in host defense and give a richer understanding of superoxide's varied biology.","pmid":"36609987","doi":"10.1111/imr.13183","url":"https://pubmed.ncbi.nlm.nih.gov/36609987/"},{"id":653,"title":"Ratiometric and colorimetric probes with large stokes shift for sensing of exogenous hypochlorite in potato sprouts and industrial effluents.","authors":"Assiri, Mohammed A; Waseem, Muhammad Tahir; Hamad, Asad; Imran, Muhammad; Farooq, Umar; Shahzad, Sohail Anjum","year":2023,"date":"2023 Apr 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Being one of the important reactive oxygen species (ROS), hypochlorite ions (ClO(-)) are involved in the control of several pathological and physiological processes. However, overexpression of ClO(-) may prompt several disorders including cancer. Therefore, two fluorescein functionalized compounds with catechol (probe 1) and 2-naphthyl (probe 2) as substituents were synthesized through Schiff base reaction to recognize ClO(-) in food items and industrial samples. While probe 2 exhibited turn-off fluorescent response towards ClO(-) with limit of detection (LOD) of 86.7 nM, structurally alike probe 1 showed excellent ratiometric response with low detection limit (36.3 nM), large Stokes shift (353 nm), and 'fast' response time (15 s). (1)H NMR titration experiments favored spiroring opening of probe 1 upon the reaction with ClO(-). Probe 1 was successfully utilized for the monitoring of exogenous ClO(-) in industrial samples. Further, fabrication of probe coated fluorescent paper strips and recognition of ClO(-) in sprouting potato show diverse practical applicability of our probes.","pmid":"36603278","doi":"10.1016/j.saa.2022.122298","url":"https://pubmed.ncbi.nlm.nih.gov/36603278/"},{"id":654,"title":"Near-source hypochlorous acid emissions from indoor bleach cleaning.","authors":"Stubbs, Annastacia D; Lao, Melodie; Wang, Chen; Abbatt, Jonathan P D; Hoffnagle, John; VandenBoer, Trevor C; Kahan, Tara F","year":2023,"date":"2023 Jan 25","journal":"Environmental science. Processes & impacts","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Cleaning surfaces with sodium hypochlorite (NaOCl) bleach can lead to high levels of gaseous chlorine (Cl(2)) and hypochlorous acid (HOCl); these have high oxidative capacities and are linked to respiratory issues. We developed a novel spectral analysis procedure for a cavity ring-down spectroscopy (CRDS) hydrogen peroxide (H(2)O(2)) analyzer to enable time-resolved (3 s) HOCl quantification. We measured HOCl levels in a residential bathroom while disinfecting a bathtub and sink, with a focus on spatial and temporal trends to improve our understanding of exposure risks during bleach use. Very high (>10 ppmv) HOCl levels were detected near the bathtub, with lower levels detected further away. Hypochlorous acid concentrations plateaued in the room at a level that depended on distance from the bathtub. This steady-state concentration was maintained until the product was removed by rinsing. Mobile experiments with the analyzer inlet secured to the researcher's face were conducted to mimic potential human exposure to bleach emissions. The findings from mobile experiments were consistent with the spatial and temporal trends observed in the experiments with fixed inlet locations. This work provides insight on effective strategies to reduce exposure risk to emissions from bleach and other cleaning products.","pmid":"36602445","doi":"10.1039/d2em00405d","url":"https://pubmed.ncbi.nlm.nih.gov/36602445/"},{"id":655,"title":"Comparison of hyaluronic acid, hypochlorous acid, and flurbiprofen on postoperative morbidity in palatal donor area: a randomized controlled clinical trial.","authors":"Alpan, Aysan Lektemur; Cin, Gizem Torumtay","year":2023,"date":"2023 Jun","journal":"Clinical oral investigations","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"OBJECTIVE: This study aims to evaluate the effects of topical hyaluronic acid (HA), hypochlorous acid (HOCl), and flurbiprofen on postoperative morbidity of palatal donor sites after free gingival graft (FGG) surgery. MATERIALS AND METHODS: Sixty patients requiring FGG were randomly assigned into four groups: control, HA gel (600 mg/100 g high molecular weight hyaluronic acid), HOCl spray (170-200 ppm, ph7.1), flurbiprofen spray (0.075gr flurbiprofen). Topical agents were applied for 14 days, according to groups. Patients were followed for 28 days. Palatal healing was assessed with the Laundry wound healing index (WHI). Complete epithelization (CE) was evaluated with photographs and H(2)O(2) bubbling. Pain, burning sensation, chewing efficacy, and tissue color match (CM) were evaluated using a visual analog scale (VAS). Postoperative analgesic consumption and delayed bleeding (DB) were also recorded. RESULTS: HA provided better WHI values on the 7(th), 14(th), and 21(st) days compared to the other groups, respectively (p < 0.05). CE was formed on the 21(st) day in the HA group but on the 28(th) day in the other groups. HOCl and flurbiprofen groups were not different from the control group or each other in terms of WHI. HOCl had the lowest VAS scores of all time periods. DB was not observed in any group. Significantly fewer analgesics were taken in the topical agent-applied groups compared to the control group. CONCLUSIONS: HA exhibits a positive impact on the epithelization of palatal wound healing and color matching. HOCl and flurbiprofen provided less pain; however, they might have negative effects on palatal wound healing. CLINICAL RELEVANCE: As a result of obtaining free gingival grafts from palatal tissue for mucogingival surgical procedures, secondary wound healing of the donor area occurs. This wound in the palatal region can cause discomfort and pain every time patients use their mouths. The use of HA can reduce postoperative complications by accelerating wound healing and reducing pain. The topical use of flurbiprofen and HOCl can reduce patients' pain.","pmid":"36595064","doi":"10.1007/s00784-022-04848-5","url":"https://pubmed.ncbi.nlm.nih.gov/36595064/"},{"id":658,"title":"Physicochemical evaluation of hydrogen peroxide bleaching gels containing titanium dioxide catalytic agent, and their influence on dental color change associated with violet LED.","authors":"Carlos, Natália Russo; Basting, Rosanna Tarkany; Amaral, Flávia Lucisano Botelho do; França, Fabiana Mantovani Gomes; Turssi, Cecilia Pedroso; Kantovitz, Kamila Rosamilia; Bronze-Uhle, Erika Soares; Lisboa Filho, Paulo Noronha; Cavalli, Vanessa; Basting, Roberta Tarkany","year":2023,"date":"2023 Mar","journal":"Photodiagnosis and photodynamic therapy","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"BACKGROUND: The purpose of this study was: 1) to analyze the physical-chemical properties of hydrogen peroxide (HP) agents at 7.5% (HP7) and 35% (HP35), and the association with or without TiO(2) nanotubes; 2) to evaluate dental bleaching effectiveness by using HP7 and HP35 together with or without TiO(2) nanotubes, and applied with or without violet LED (VL). METHODOLOGY: 80 bovine incisors were treated according to groups (n = 10): HP35; HP35 + VL; HP35T (HP35 + TiO(2)); HP35T + VL; HP7; HP7 + VL; HP7T (HP7 + TiO(2)); HP7T + VL. Bleaching effectiveness was measured at 4 time points according to the Vita Classical, CIEL*a*b*, CIEDE2000, and WI(D) parameters. HP35, HP35T, HP7, and HP7T were evaluated for mass change, pH, mean particle size (P), polydispersity (PDI), and zeta potential (ZP), over 6 months of storage. RESULTS: The pH of HP35 thickener was higher when associated to TiO(2). At baseline, both of the bleaching gels containing TiO(2) had lower P, PDI, and PZ (p < 0.05). All groups showed a significant decrease in Vita Classical color scores (p = 0.0037). There was a higher L* value, and lower b* values for HP7 when associated to VL after the 3rd session. (p < 0.05). HP35T showed higher color change (ΔE(ab), ΔE(00)), and lower a* value in the presence of VL (p < 0.05). ΔWI(D) presented lower values for both gels, when TiO(2) was incorporated (p ≤ 0.05). CONCLUSION: The incorporation of TiO(2) to the bleaching gel showed good stability with minimal variations in physical-chemical properties. The color change in HP35 was more effective than in HP7, but the VL boosted the bleaching effectiveness of HP7, whereas TiO(2) did not increase bleaching effectiveness.","pmid":"36572111","doi":"10.1016/j.pdpdt.2022.103254","url":"https://pubmed.ncbi.nlm.nih.gov/36572111/"},{"id":660,"title":"An improved method for the detection of myeloperoxidase chlorinating activity in biological systems using the redox probe hydroethidine.","authors":"Vigder, Niv; Suarna, Cacang; Corcilius, Leo; Nadel, James; Chen, Weiyu; Payne, Richard; Tumanov, Sergey; Stocker, Roland","year":2023,"date":"2023 Feb 1","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Conversion of the redox probe hydroethidine (HE) to 2-chloroethidium (2-Cl-E(+)) by myeloperoxidase (MPO)-derived hypochlorous acid (HOCl) provides comparable specificity and superior sensitivity to measurement of 3-chlorotyrosine (3-Cl-Tyr), the gold standard biomarker for MPO chlorinating activity in biological systems. However, a limitation of the former method is the complex mixture of products formed by the reaction of HE with reagent HOCl, coupled with the difficult purification of 2-Cl-E(+) from this mixture for analytical purposes. This limitation prompted us to test whether 2-Cl-E(+) could be formed by reaction of HE with the strong and widely used chlorinating agent, N-chlorosuccinimide (NCS). Unexpectedly, such reaction yielded 2-chlorohydroethidine (2-Cl-HE) as the major product in addition to 2-Cl-E(+), as assessed by high performance liquid chromatography (HPLC), mass spectrometry (MS), and nuclear magnetic resonance (NMR). 2-Cl-HE was also observed to be the major chlorination product formed from HE with both reagent and enzymatically generated HOCl, just as it was formed ex vivo in different healthy and diseased mouse and human tissues upon incubation with glucose/glucose oxidase to generate a flux of hydrogen peroxide (H(2)O(2)). Quantification of 2-Cl-HE plus 2-Cl-E(+) improved the sensitivity of the HE-based method compared with measurement of only 2-Cl-E(+). Moreover, 2-chlorodimidium (2-Cl-D(+)) was developed as a practical internal standard instead of the previously used internal standard, deuterated 2-Cl-E(+) (d(5)-2-Cl-E(+)). Overall, the present study describes an improved method for the detection of MPO/chlorinating activity in biological systems of health and disease.","pmid":"36565892","doi":"10.1016/j.freeradbiomed.2022.12.014","url":"https://pubmed.ncbi.nlm.nih.gov/36565892/"},{"id":661,"title":"Amino acid buffered hypochlorite facilitates debridement of porcine infected burn wounds.","authors":"Alexander P, Larsson; Jonathan, Rakar; Gunnar, Kratz; Johan P E, Junker","year":2023,"date":"2023 Sep","journal":"Burns : journal of the International Society for Burn Injuries","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"INTRODUCTION: Removal of necrotic tissue is a vital step in the treatment of full-thickness burn wounds, with surgical debridement being the most effective method. Since minor burn wounds are typically treated on an outpatient basis where surgical capabilities can be limited there is a need for alternative treatment options. In this study we aim to evaluate the use of amino acid buffered hypochlorite (AABH) as a chemical enhancement for wound debridement in a porcine infected burn wound model. METHOD: A total of 60 full-thickness burn wounds, 3 cm in diameter, were created on four pigs using a standardized burn device. The wounds were inoculated with 10(7) colony-forming units (CFU) of S. aureus. The experimental groups included wounds debrided with a plastic curette, wounds debrided after pretreatment with AABH, and control wounds wiped with gauze. Wounds were treated twice per week for three weeks. Debridement, healing, and infection parameters were evaluated over time. RESULTS: After one week, but not after two and three weeks, the curette and AABH groups had higher debrided weights compared to control (p < 0.05). Percentage of wound area adequately cleared from necrotic tissue was higher in the AABH-group compared to the curette-group and control, after one week. The earliest healing was measured in the AABH group after two weeks (5 % of wounds), which also had the most healed wounds after three weeks (55 %). In both the AABH and the curette groups, bacterial load had fallen below 10(5) CFU/g after two weeks. No CFU were detectable in the AABH group after three weeks. The AABH-group was also the easiest to debride. CONCLUSION: Our results indicate that AABH facilitates wound debridement and could be a helpful addition to an effective treatment modality for removal of necrotic tissue in full-thickness burns.","pmid":"36543728","doi":"10.1016/j.burns.2022.11.011","url":"https://pubmed.ncbi.nlm.nih.gov/36543728/"},{"id":662,"title":"Evaluation of hypochlorous acid as an ear flush in dogs with chronic otitis externa.","authors":"Mueller, Ralf S; Baumann, Katja N; Boehm, Teresa; Dörfelt, Stefanie; Kasper, Bettina; Udraite-Vovk, Laura","year":2023,"date":"2023 Apr","journal":"Veterinary dermatology","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"BACKGROUND: Chronic otitis externa (OE) in dogs frequently requires anaesthetised ear flushing. OBJECTIVES: To evaluate hypochlorous acid as an ear flushing and antimicrobial agent in dogs with chronic OE. ANIMALS: Twenty dogs with chronic OE caused by the same organisms bilaterally. MATERIALS AND METHODS: One ear was flushed under anaesthesia with hypochlorous acid, the other with saline solution. Subsequently, the ear flushed with hypochlorous acid was cleaned with the same solution twice daily for 2 weeks, the other ear with a commercial ear cleaner. An ear medication containing miconazole, polymyxin B and prednisolone was used once daily in both ears. Clinical scores were determined before the flush. Ear cytological results were obtained, a hearing test was conducted before and after the ear flush, and a culture was taken directly after flushing. Ears were evaluated after 2 weeks of therapy. RESULTS: Yeast was present in the ears of 11, cocci in one and a mixed infection in eight dogs. Five ears were negative on culture after flushing with hypochlorous acid, one after the saline flush. Clinical and cytological scores decreased significantly with both solutions after 2 weeks of treatment. There was no difference between treatments in any of the scores at any time point between treatments and in the results of the hearing test before and after the flushing procedure. Adverse effects were not seen. CONCLUSIONS AND CLINICAL RELEVANCE: Hypochlorous acid is a suitable cleaning solution for canine OE.","pmid":"36517454","doi":"10.1111/vde.13142","url":"https://pubmed.ncbi.nlm.nih.gov/36517454/"},{"id":665,"title":"Myeloperoxidase-derived hypochlorous acid targets human airway epithelial plasmalogens liberating protein modifying electrophilic 2-chlorofatty aldehydes.","authors":"Shakya, Shubha; Pyles, Kelly D; Albert, Carolyn J; Patel, Rakesh P; McCommis, Kyle S; Ford, David A","year":2023,"date":"2023 Feb","journal":"Redox biology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Neutrophil and airway epithelial cell interactions are critical in the inflammatory response to viral infections including respiratory syncytial virus, Sendai virus, and SARS-CoV-2. Airway epithelial cell dysfunction during viral infections is likely mediated by the interaction of virus and recruited neutrophils at the airway epithelial barrier. Neutrophils are key early responders to viral infection. Neutrophil myeloperoxidase catalyzes the conversion of hydrogen peroxide to hypochlorous acid (HOCl). Previous studies have shown HOCl targets host neutrophil and endothelial cell plasmalogen lipids, resulting in the production of the chlorinated lipid, 2-chlorofatty aldehyde (2-ClFALD). We have previously shown that the oxidation product of 2-ClFALD, 2-chlorofatty acid (2-ClFA) is present in bronchoalveolar lavage fluid of Sendai virus-infected mice, which likely results from the attack of the epithelial plasmalogen by neutrophil-derived HOCl. Herein, we demonstrate small airway epithelial cells contain plasmalogens enriched with oleic acid at the sn-2 position unlike endothelial cells which contain arachidonic acid enrichment at the sn-2 position of plasmalogen. We also show neutrophil-derived HOCl targets epithelial cell plasmalogens to produce 2-ClFALD. Further, proteomics and over-representation analysis using the ω-alkyne analog of the 2-ClFALD molecular species, 2-chlorohexadecanal (2-ClHDyA) showed cell adhesion molecule binding and cell-cell junction enriched categories similar to that observed previously in endothelial cells. However, in contrast to endothelial cells, proteins in distinct metabolic pathways were enriched with 2-ClFALD modification, particularly pyruvate metabolism was enriched in epithelial cells and mitochondrial pyruvate respiration was reduced. Collectively, these studies demonstrate, for the first time, a novel plasmalogen molecular species distribution in airway epithelial cells that are targeted by myeloperoxidase-derived hypochlorous acid resulting in electrophilic 2-ClFALD, which potentially modifies epithelial physiology by modifying proteins.","pmid":"36508858","doi":"10.1016/j.redox.2022.102557","url":"https://pubmed.ncbi.nlm.nih.gov/36508858/"},{"id":666,"title":"Elevated levels of chloramines and chlorine detected near an indoor sports complex.","authors":"Angelucci, Andrea A; Crilley, Leigh R; Richardson, Rob; Valkenburg, Thalassa S E; Monks, Paul S; Roberts, James M; Sommariva, Roberto; VandenBoer, Trevor C","year":2023,"date":"2023 Feb 22","journal":"Environmental science. Processes & impacts","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Chloramines (NH(2)Cl, NHCl(2), and NCl(3)) are toxic compounds that can be created during the use of bleach-based disinfectants that contain hypochlorous acid (HOCl) and the hypochlorite ion (OCl(-)) as their active ingredients. Chloramines can then readily transfer from the aqueous-phase to the gas-phase. Atmospheric chemical ionization mass spectrometry using iodide adduct chemistry (I-CIMS) made observations across two periods (2014 and 2016) at an urban background site on the University of Leicester campus (Leicester, UK). Both monochloramine (NH(2)Cl) and molecular chlorine (Cl(2)) were detected and positively identified from calibrated mass spectra during both sampling periods and to our knowledge, this is the first detection of NH(2)Cl outdoors. Mixing ratios of NH(2)Cl reached up to 2.2 and 4.0 parts per billion by volume (ppbv), with median mixing ratios of 30 and 120 parts per trillion by volume (pptv) during the 2014 and 2016 sampling periods, respectively. Levels of Cl(2) were observed to reach up to 220 and 320 pptv. Analysis of the NH(2)Cl and Cl(2) data pointed to the same local source, a nearby indoor sports complex with a swimming pool and a cleaning product storage shed. No appreciable levels of NHCl(2) and NCl(3) were observed outdoors, suggesting the indoor pool was not likely to be the primary source of the observed ambient chloramines, as prior measurements made in indoor pool atmospheres indicate that NCl(3) would be expected to dominate. Instead, these observations point to indoor cleaning and/or cleaning product emissions as the probable source of NH(2)Cl and Cl(2) where the measured levels provide indirect evidence for substantial amounts transported from indoors to outdoors. Our upper estimate for total NH(2)Cl emissions from the University of Leicester indoor sports complexes scaled for similar sports complexes across the UK is 3.4 × 10(5) ± 1.1 × 10(5) μg h(-1) and 0.0017 ± 0.00034 Gg yr(-1), respectively. The Cl-equivalent emissions in HCl are only an order of magnitude less to those from hazardous waste incineration and iron and steel sinter production in the UK National Atmospheric Emissions Inventory (NAEI).","pmid":"36484250","doi":"10.1039/d2em00411a","url":"https://pubmed.ncbi.nlm.nih.gov/36484250/"},{"id":669,"title":"In Vitro Activity of a Hypochlorous Acid-Generating Electrochemical Bandage against Yeast Biofilms.","authors":"Kletzer, Joseph; Raval, Yash S; Mohamed, Abdelrhman; Mandrekar, Jayawant N; Greenwood-Quaintance, Kerryl E; Beyenal, Haluk; Patel, Robin","year":2023,"date":"2023 Jan 24","journal":"Antimicrobial agents and chemotherapy","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The antibiofilm activity of a hypochlorous acid (HOCl)-producing electrochemical bandage (e-bandage) was assessed against 14 yeast isolates in vitro. The evaluated e-bandage was polarized at +1.5 V(Ag/AgCl) to allow continuous production of HOCl. Time-dependent decreases in the biofilm CFU counts were observed for all isolates with e-bandage treatment. The results suggest that the described HOCl-producing e-bandage could serve as a potential alternative to traditional antifungal wound biofilm treatments.","pmid":"36472429","doi":"10.1128/aac.01166-22","url":"https://pubmed.ncbi.nlm.nih.gov/36472429/"},{"id":670,"title":"3-Aminophenylboronic acid-functionalized molybdenum disulfide quantum dots for fluorescent determination of hypochlorite.","authors":"Zhong, Yaping; Guo, Lijuan; Lu, Zhentan; Wang, Dong","year":2022,"date":"2022 Dec 6","journal":"Mikrochimica acta","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"A simple method is reported for hypochlorite determination based on fluorescence 3-aminophenylboronic acid-functionalized molybdenum disulfide quantum dots (B-MoS(2) QDs). B-MoS(2) QDs with strong fluorescence at 380 nm have been successfully synthesized by the amidation reaction between APBA and hydrothermal MoS(2) QDs. Hypochlorite sensing was proposed utilizing the fluorescent quenching effect of 3,3',5,5'-tetramethylbenzidine dihydrochloride (TMB) on B-MoS(2) QDs and the fast redox reaction between hypochlorite and TMB. The fluorescent quenching effect of TMB to B-MoS(2) QDs was proved to be caused by static dynamic quenching and inner filter effect. A good linear relationship was obtained in the hypochlorite concentration range from 1 to 20 μM, and the limit of detection (LOD) was 36.8 nM. The proposed fluorescent detection assay was simple and fast, taking only 5 min at room temperature. Satisfactory results were obtained in the standard spike recovery tests on tap water and milk samples, which indicate high potential in constructing fluorescent bio-detection assays.","pmid":"36471018","doi":"10.1007/s00604-022-05598-7","url":"https://pubmed.ncbi.nlm.nih.gov/36471018/"},{"id":674,"title":"Preparation of nanocellulose crystal from bleached pulp with an engineering cellulase and co-production of ethanol.","authors":"Yang, Tiantian; Li, Xuezhi; Guo, Yingjie; Zhao, Jian; Qu, Yinbo","year":2023,"date":"2023 Feb 1","journal":"Carbohydrate polymers","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The study investigated the feasibility of co-production of nanocellulose crystal (CNC) and ethanol using the bleached pine kraft pulp (BPKP) as a substrate by enzymatic hydrolysis. An engineering strain Penicillum oxalicum cEES-XM was constructed to produce suitable cellulase used in enzymatic hydrolysis of BPKP for preparing CNC. The cellulase from Trichoderma reesei SCB18 was used for simultaneous saccharification and fermentation of residues and hydrolysates from enzymatic hydrolysis for producing ethanol. The result showed that the CNC yield reached 7.35 % (w/w) by hydrolysis at 10 % solid content, and the final ethanol concentration was 13.27 mg/mL in fermentation liquor. Using SEM, XRD, TGA, and DLS methods, the characteristics of CNC including, morphology, crystallinity, thermal stability and particle size distribution, were also examined. This work provided a reference for realizing high-efficient application of cellulose in the pulp.","pmid":"36436849","doi":"10.1016/j.carbpol.2022.120291","url":"https://pubmed.ncbi.nlm.nih.gov/36436849/"},{"id":680,"title":"The Assessment of Activity of Antiseptic Agents against Biofilm of Staphylococcus aureus Measured with the Use of Processed Microscopic Images.","authors":"Krasowski, Grzegorz; Migdał, Paweł; Woroszyło, Marta; Fijałkowski, Karol; Chodaczek, Grzegorz; Czajkowska, Joanna; Dudek, Bartłomiej; Nowicka, Joanna; Oleksy-Wawrzyniak, Monika; Kwiek, Bartłomiej; Paleczny, Justyna; Brożyna, Malwina; Junka, Adam","year":2022,"date":"2022 Nov 4","journal":"International journal of molecular sciences","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Staphylococcal biofilms are major causative factors of non-healing wound infections. Their treatment algorithms recommend the use of locally applied antiseptic agents to counteract the spread of infection. The efficacy of antiseptics against biofilm is assessed in vitro by a set of standard quantitative and semi-quantitative methods. The development of software for image processing additionally allowed for the obtainment of quantitative data from microscopic images of biofilm dyed with propidium iodine and SYTO-9 reagents, differentiating dead cells from live ones. In this work, the method of assessment of the impact of antiseptic agents on staphylococcal biofilm in vitro, based on biofilms' processed images, was proposed and scrutinized with regard to clinically relevant antiseptics, polyhexanide, povidone-iodine and hypochlorite. The standard quantitative culturing method was applied to validate the obtained data from processed images. The results indicated significantly higher activity of polyhexanide and povidone-iodine than hypochlorite against staphylococcal biofilm. Taking into account the fact that in vitro results of the efficacy of antiseptic agents against staphylococcal biofilm are frequently applied to back up their use in hospitals and ambulatory units, our work should be considered an important tool; providing reliable, quantitative data in this regard.","pmid":"36362310","doi":"10.3390/ijms232113524","url":"https://pubmed.ncbi.nlm.nih.gov/36362310/"},{"id":685,"title":"Chlorination-induced pK(a) decrease: an improved strategy to design ratiometric hypochlorite fluorescent probes with ideally high selectivity.","authors":"Han, Shaohui; Ding, Binghui; Xiong, Haiqing; Zuo, Bojun; Ye, Yong; Li, Haipu; Song, Xiangzhi","year":2022,"date":"2022 Nov 21","journal":"The Analyst","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Based on the selective ClO(-)-triggered chlorination reaction and the subsequent pK(a) decrease of phenols, a new strategy was developed for rationally designing ratiometric ClO(-) fluorescent probes with high selectivity. By investigating the fluorescence responses of 6-cyano-2-naphthol toward ClO(-) and the pK(a)-dependent response mechanism, we developed a rapid, sensitive and selective two-photon ratiometric fluorescent probe, Naph-DFOB, to detect ClO(-). This probe displayed a ratiometric fluorescence change (from 509 nm to 628 nm) toward ClO(-) and was successfully applied to image intracellular ClO(-) in living cells with two-photon excitation. Using Naph-DFOB as a useful tool, the investigation of lipopolysaccharide (LPS)-induced acute lung injury in a mouse model was effectively performed.","pmid":"36345932","doi":"10.1039/d2an01476a","url":"https://pubmed.ncbi.nlm.nih.gov/36345932/"},{"id":686,"title":"Disinfectant resistance of Salmonella in in vitro contaminated poultry house models and investigation of efficient disinfection methods using these models.","authors":"Ohashi, Ikuyo; Kobayashi, Sota; Tamamura-Andoh, Yukino; Arai, Nobuo; Takamatsu, Daisuke","year":2022,"date":"2022 Dec 14","journal":"The Journal of veterinary medical science","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Salmonellaenterica subsp. enterica (Salmonella) shows disinfectant resistance by forming biofilms on solid surfaces. However, efficient disinfection methods to eliminate Salmonella biofilms from farms have not yet been examined in detail. In this study, more than 80% of Salmonella strains from farms in Yamagata prefecture, Japan, were biofilm producers. Regardless of the extent of their biofilm formation ability, their biofilms were highly resistant to hypochlorous acid on plastic surfaces. To establish efficient disinfection methods in farms, we developed in vitro Salmonella-contaminated poultry house models by depositing dust on ceramic and stainless-steel carriers in poultry houses for one month and culturing a representative Salmonella strain on the carriers. Biofilm-like structures, including Salmonella-like cells, were observed on the models by scanning electron microscopy. Salmonella was not efficiently removed from the models even by cleaning with a surfactant at 25/65°C and disinfection with quaternary ammonium compound or hypochlorous acid at 25°C; on the contrary, viable Salmonella cells increased in some tests under these conditions, suggesting that these models successfully simulate the highly persistent characteristics of Salmonella in farms. However, the persistent bacterial cells were markedly decreased by soaking in 65°C surfactant followed by rinsing with 80°C water, additional cleaning using chlorine dioxide or disinfection with dolomitic lime, suggesting the effectiveness of these methods against Salmonella in farms. Since many different disinfection conditions may be easily tested in laboratories, our models will be useful tools for establishing effective and practical disinfection methods in farms.","pmid":"36328590","doi":"10.1292/jvms.22-0311","url":"https://pubmed.ncbi.nlm.nih.gov/36328590/"},{"id":687,"title":"The Lesson Learned from the COVID-19 Pandemic: Can an Active Chemical Be Effective, Safe, Harmless-for-Humans and Low-Cost at a Time? Evidence on Aerosolized Hypochlorous Acid.","authors":"Benedusi, Mascia; Tamburini, Elena; Sicurella, Mariaconcetta; Summa, Daniela; Ferrara, Francesca; Marconi, Peggy; Cervellati, Franco; Costa, Stefania; Valacchi, Giuseppe","year":2022,"date":"2022 Oct 13","journal":"International journal of environmental research and public health","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The COVID-19 pandemic has underlined the importance of disinfectants as tools to prevent and fight against coronavirus spreading. An ideal disinfectant and sanitizer must be nontoxic to surface contact, noncorrosive, effective, and relatively inexpensive as it is hypochlorous acid (HOCl). The present work intended to evaluate, on different surfaces, the bactericidal and virucidal effectiveness of nebulized HOCl and test its safety usage in 2D and 3D skin and lung models. Our data showed that HOCl at the dose of 300 ppm did not affect cellular and tissue viability, not their morphology. The HOCl bactericidal properties varies with the surface analyzed: 69% for semi-porous, 96-99.9% for flat and porous. This discrepancy was not noticed for the virucidal properties. Overall, this study showed that nebulized HOCl can prevent virus and bacteria growth without affecting lung and skin tissues, making this compound a perfect candidate to sanitize indoor environments.","pmid":"36293740","doi":"10.3390/ijerph192013163","url":"https://pubmed.ncbi.nlm.nih.gov/36293740/"},{"id":689,"title":"A converged approach of electro-biological process for decolorization and degradation of toxic synthetic dyes.","authors":"Annamalai, Sivasankar; Muthukumar, Venkatesan; Alkhulaifi, Manal M","year":2022,"date":"2022 Oct 22","journal":"Environmental monitoring and assessment","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Being one of the leading industries worldwide, the textile industry has been consuming large quantities of groundwater and discharging huge volumes of dye-contaminated effluents into our aquatic environment. Augmentation of water sources via reuse of treated effluents is therefore highly necessary. In the present study, the decolorization and degradation of synthetic toxic dye from an aqueous solution were investigated through an electro-biological route. Initially, decolorization of synthetic dye solutions (100, 500, and 1000 mg L(-1)) was carried out by electrooxidation process using mixed metal oxide and titanium as anode and cathode, respectively. The electrooxidation solutions were further treated using bacteria (Pseudomonas aeruginosa) that were isolated from petroleum-transporting pipelines. UV-Vis, TOC, chemical oxygen demand, and NMR analyses revealed that the biodegradation process with electrooxidation enhanced the mineralization of the synthetic dye solutions. An optimum NaCl electrolyte concentration of 3 g L(-1) was sufficient to produce reactive species viz., free chlorine and hypochlorite, which are responsible for the Reactive Blue 19 (RB-19) decolorization. Among the three RB-19 concentrations, the highest removal percentage was noticed at 100 mg L(-1) (100%) with energy consumption and energy costs equal to 5.44 kWh m(-3) and 0.65 USD m(-3), respectively.","pmid":"36271209","doi":"10.1007/s10661-022-10583-x","url":"https://pubmed.ncbi.nlm.nih.gov/36271209/"},{"id":690,"title":"An Intensive Multidisciplinary Approach in Management of Extensive Nonuremic Calciphylaxis of the Bilateral Lower Extremities with Angioinvasive Fungus and Mold.","authors":"Roberson, Jeffrey L; Butt, Zoya; Florez-Pollack, Stephanie; Morgan, Eric; Rosenbach, Misha; Braslow, Benjamin M; Yelon, Jay A","year":2023,"date":"2023 Jan 5","journal":"Journal of burn care & research : official publication of the American Burn Association","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"Management of infected wounds related to calciphylaxis poses a significant clinical challenge with high morbidity and mortality. Given no definitive management guidelines exist specific to nonuremic calciphylaxis, multiple modalities including sodium thiosulfate, antibiotics, hyperbaric oxygen therapy, and surgical debridement with wound care must be considered. When occurring over a large surface area, standard daily dressing changes are especially labor intensive, inefficient, and ineffective. Negative pressure wound therapy with instillation and dwell time offers broad wound coverage with ongoing therapeutic benefit. We present the case of a previously healthy 19-year-old woman who was transferred for tertiary level care of extensive nonuremic calciphylaxis wounds of the bilateral lower extremities complicated by angioinvasive coinfection with fungus and mold that was managed with a multidisciplinary approach of intensive medical management, aggressive surgical debridement, and negative pressure wound therapy with instillation of hypochlorous acid solution. Ultimately, she achieved full granulation and wound coverage with skin grafting. Large area, infected wounds related to nonuremic calciphylaxis can be successfully managed with multidisciplinary medical management, aggressive surgical debridement, and negative pressure wound therapy that can instill and dwell hypochlorous acid solution.","pmid":"36269818","doi":"10.1093/jbcr/irac158","url":"https://pubmed.ncbi.nlm.nih.gov/36269818/"},{"id":702,"title":"In Vitro and In Vivo Antimicrobial Activity of Hypochlorous Acid against Drug-Resistant and Biofilm-Producing Strains.","authors":"Palau, Marta; Muñoz, Estela; Lujan, Enric; Larrosa, Nieves; Gomis, Xavier; Márquez, Ester; Len, Oscar; Almirante, Benito; Abellà, Jordi; Colominas, Sergi; Gavaldà, Joan","year":2022,"date":"2022 Oct 26","journal":"Microbiology spectrum","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The aims of this study were as follows. First, we determined the antimicrobial efficacy of hypochlorous acid (HClO) against bacterial, fungal, and yeast strains growing planktonically and growing in biofilms. Second, we sought to compare the activity of the combination of daptomycin and HClO versus those of the antimicrobial agents alone for the treatment of experimental catheter-related Staphylococcus epidermidis infection (CRI) using the antibiotic lock technique (ALT) in a rabbit model. HClO was generated through direct electric current (DC) shots at determined amperages and times. For planktonic susceptibility studies, 1 to 3 DC shots of 2, 5, and 10 mA from 0 to 300 s were applied. A DC shot of 20 mA from 0 to 20 min was applied to biofilm-producing strains. Central venous catheters were inserted into New Zealand White rabbits, inoculated with an S. epidermidis strain, and treated with saline solution or ALT using daptomycin (50 mg/mL), HClO (20 mA for 45 min), or daptomycin plus HClO. One hundred percent of the planktonic bacterial, fungal, and yeast strains were killed by applying one DC shot of 2, 5, and 10 mA, respectively. One DC shot of 20 mA for 20 min was sufficient to eradicate 100% of the tested biofilm-producing strains. Daptomycin plus HClO lock therapy showed the highest activity for experimental CRI with S. epidermidis. HClO could be an effective strategy for treating infections caused by extensively drug-resistant or multidrug-resistant and biofilm-producing strains in medical devices and chronic wounds. The results of the ALT using daptomycin plus HClO may be promising. IMPORTANCE Currently, drug-resistant infections are increasing and there are fewer antibiotics available to treat them. Therefore, there is an urgent need to find new antibiotics and nonantimicrobial strategies to treat these infections. We present a new nonantibiotic strategy based on hypochlorous acid generation to treat long-term catheter-related and chronic wounds infections.","pmid":"36190404","doi":"10.1128/spectrum.02365-22","url":"https://pubmed.ncbi.nlm.nih.gov/36190404/"},{"id":704,"title":"Activity of a hypochlorous acid-producing electrochemical bandage as assessed with a porcine explant biofilm model.","authors":"Tibbits, Gretchen; Mohamed, Abdelrhman; Gelston, Suzanne; Flurin, Laure; Raval, Yash S; Greenwood-Quaintance, Kerryl E; Patel, Robin; Beyenal, Haluk","year":2023,"date":"2023 Jan","journal":"Biotechnology and bioengineering","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The activity of a hypochlorous acid-producing electrochemical bandage (e-bandage) in preventing methicillin-resistant Staphylococcus aureus infection (MRSA) infection and removing biofilms formed by MRSA was assessed using a porcine explant biofilm model. e-Bandages inhibited S. aureus infection (p = 0.029) after 12 h (h) of exposure and reduced 3-day biofilm viable cell counts after 6, 12, and 24 h exposures (p = 0.029). Needle-type microelectrodes were used to assess HOCl concentrations in explant tissue as a result of e-bandage treatment; toxicity associated with e-bandage treatment was evaluated. HOCl concentrations in infected and uninfected explant tissue varied between 30 and 80 µM, decreasing with increasing distance from the e-bandage. Eukaryotic cell viability was reduced by an average of 71% and 65% in fresh and day 3-old explants, respectively, when compared to explants exposed to nonpolarized e-bandages. HOCl e-bandages are a promising technology that can be further developed as an antibiotic-free treatment for wound biofilm infections.","pmid":"36168277","doi":"10.1002/bit.28248","url":"https://pubmed.ncbi.nlm.nih.gov/36168277/"},{"id":705,"title":"Violet LED associated with high concentration hydrogen peroxide: Effects on bleaching efficacy, pH, and temperature.","authors":"Manzoli, Tatiane Miranda; Costa, Joatan Lucas de Sousa Gomes; Besegato, João Felipe; Gelio, Mariana Bena; Galvani, Lucas David; Bordini, Ester Alves Ferreira; Kuga, Milton Carlos; Dantas, Andréa Abi Rached","year":2022,"date":"2022 Dec","journal":"Photodiagnosis and photodynamic therapy","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"BACKGROUND: This study aimed to evaluate the bleaching efficacy, pH, and temperature of 35% hydrogen peroxide (HP) gel used alone or associated with violet LED. METHODS: Sixty bovine crowns were sectioned (5 × 5 × 2mm). After staining with black tea, the specimens were randomized into four groups (n = 10) according to the bleaching protocol: HP35R: 3 × 15 min 35% HP; HP35: 1 × 45 min 35% HP; HP35VR: 3 × 8min 35% HP + Violet LED; HP35V: 1 × 24 min + Violet LED. Two bleaching sessions were performed for all the groups. Color change was evaluated before, 24h after each session, 7 days and 15 days after the last session. The variables ∆E(00) [CIEDE2000] and W(ID) were used for color analysis. The pH variation (initial and final) and the temperature of the gel were recorded (n = 5). ANOVA two-way for repeated measures and Bonferroni post-test was used at a significance level of 5%. RESULTS: HP35VR and HP35V the most noticeable color change(p < 0.05). The final values of pH were lower than the initial ones, but with no difference between the groups (p > 0.05). Groups HP35VR and HP35V showed an increase in temperature in relation to HP35R (p < 0.05). CONCLUSIONS: Violet LED improved the bleaching efficacy of 35% HP in a time-saving manner without negatively affecting the pH and temperature of 35% HP. The renewal of HP did not influence the outcomes.","pmid":"36162757","doi":"10.1016/j.pdpdt.2022.103133","url":"https://pubmed.ncbi.nlm.nih.gov/36162757/"},{"id":706,"title":"Malate synthase contributes to the survival of Salmonella Typhimurium against nutrient and oxidative stress conditions.","authors":"Sarkhel, Ratanti; Apoorva, Shekhar; Priyadarsini, Swagatika; Sridhar, Hari Balaji; Bhure, Sanjeev Kumar; Mahawar, Manish","year":2022,"date":"2022 Sep 25","journal":"Scientific reports","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"To survive and replicate in the host, S. Typhimurium have evolved several metabolic pathways. The glyoxylate shunt is one such pathway that can utilize acetate for the synthesis of glucose and other biomolecules. This pathway is a bypass of the TCA cycle in which CO(2) generating steps are omitted. Two enzymes involved in the glyoxylate cycle are isocitrate lyase (ICL) and malate synthase (MS). We determined the contribution of MS in the survival of S. Typhimurium under carbon limiting and oxidative stress conditions. The ms gene deletion strain (∆ms strain) grew normally in LB media but failed to grow in M9 minimal media supplemented with acetate as a sole carbon source. However, the ∆ms strain showed hypersensitivity (p < 0.05) to hypochlorite. Further, ∆ms strain has been significantly more susceptible to neutrophils. Interestingly, several folds induction of ms gene was observed following incubation of S. Typhimurium with neutrophils. Further, ∆ms strain showed defective colonization in poultry spleen and liver. In short, our data demonstrate that the MS contributes to the virulence of S. Typhimurium by aiding its survival under carbon starvation and oxidative stress conditions.","pmid":"36155623","doi":"10.1038/s41598-022-20245-0","url":"https://pubmed.ncbi.nlm.nih.gov/36155623/"},{"id":707,"title":"COVID-19, Overzealous Sanitizer Use, and Hair Discoloration: Case Reports.","authors":"Sadat Sadati, Maryam; Nozari, Farnoosh","year":2022,"date":"2022 Jul","journal":"Acta dermatovenerologica Croatica : ADC","category":"Food & agriculture","evidence":"Case report","relevance":"High","abstract":"Proper hand hygiene is one of the top preventive measures against the Coronavirus Disease 2019 (COVID-19). In this study, we report the cases of four patients who presented with blonde discoloration of hair of the dorsal hands and distal forearms during the COVID-19 pandemic. The mean age of participants was 41.25±4.35 years, and 75% percent of them were men. Three patients were medical staff who had to use antiseptics frequently, and one of them was a housewife. In all participants, the primary color of hand hair was black. The duration of sanitizer use was approximately four months (Table 1). One of the patients, a 42-year-old male ophthalmologist, was examined due to the blonde discoloration of hairs of the dorsal hands and distal forearms (Figure 1). The color of the hand and forearms hair had changed to blonde. However, the underlying skin was unaffected. A dermoscopy examination showed lighter hair compared with the natural black hair of unaffected parts. In addition, the hair color of the scalp, upper arms, and other body parts was normal. The patient had frequently used a hand sanitizer that contained 70% ethanol and didecyl dimethyl ammonium chloride (DDAC) for the past five months. The three other patients also had blonde discoloration observable on the hair of dorsal hands. They all reported excessive use of various alcoholic sanitizers. However, they were unaware of other ingredients. In addition, the examination of hair shafts and underlying skin was normal. The COVID-19 pandemic caused an abrupt increase in the use of sanitizers. Hand disinfectants consist of two main categories: non-alcohol-based hand sanitizers and alcohol-based hand sanitizers. The alcohol-based type is an effective measure for the inactivation of enveloped viruses such as coronaviruses (1). It has been shown that percutaneous absorption of alcohol is possible through intact skin. The use of ethanol as a penetration enhancer for pharmaceutical purposes also confirms that ethanol can be absorbed via the skin and be systematically distributed in the body (2). Reisfield et al. observed that intensive use of ethanol-based sanitizers led to an increase in urinary ethanol biomarkers concentrations (3). Alcohols used in various types of gels and solutions are easily released during hand rubbing (4). Ethanol absorption by inhalation should therefore also be taken into account (5). Different pathways of ethanol metabolism can produce free radicals, which affect the antioxidant system (6). In addition, DDAC is also associated with cell growth inhibition and stress oxidative induction (7). Hair discoloration may be a voluntary cosmetic change or a result of chemical or metal exposure. Most unwanted hair discolorations are blonde or white (8). Previous data suggested that an increase in pro-oxidants and a decrease in antioxidants play an important role in hair discoloration. A study performed by Akin Belli et al. demonstrated that hair discoloration is closely related to factors such as emotional stress and alcohol consumption, which cause oxidative stress (9). Hair discoloration might therefore result from oxidative stress induced by ethanol and DDAC used in sanitizers. Golden hair discoloration has been associated with chloride in water. Hypochlorous acid in swimming pool water can penetrate the hair cortex through the cuticle, where it can oxidize and degenerate melanosomes (10). Another possible hypothesis is that the chloride compound in DDAC might be the culprit in sanitizer hair discoloration. Additionally, the bleaching compounds used in some hand disinfectants could be another possible cause of hair discoloration. To the best of our knowledge, this observation of hair discoloration was not previously reported during the COVID-19 outbreak. It is also noteworthy that most hair discoloration normalizes over time (8). The limitations of our study included the fact that the hand sanitizers used by the patients were unavailable and thus their ingredients could not be examined. Furthermore, as most of the sanitizers in this current pandemic are not standardized, they may have unknown ingredients with discoloration properties. Due to the overzealous use of various antiseptics during the pandemic, it is expected that this side-effect will be observed more and more often. Therefore, physicians must be aware of this presentation and reassure the patient regarding this phenomenon. Additionally, products free of such agents should be prescribed to avoid hair discoloration.","pmid":"36153721","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/36153721/"},{"id":708,"title":"Mapping the modification of histones by the myeloperoxidase-derived oxidant hypochlorous acid (HOCl).","authors":"Hallberg, Line A E; Thorsen, Nicoline W; Hartsema, Els A; Hägglund, Per M; Hawkins, Clare L","year":2022,"date":"2022 Nov 1","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Histones are critical for the packaging of nuclear DNA and chromatin assembly, which is facilitated by the high abundance of Lys and Arg residues within these proteins. These residues are also the site of a range of post-translational modifications, which influence the regulatory function of histones. Histones are also present in the extracellular environment, following release by various pathways, particularly neutrophil extracellular traps (NETs). NETs contain myeloperoxidase, which retains its enzymatic activity and produces hypochlorous acid (HOCl). This suggests that histones could be targets for HOCl under conditions where aberrant NET release is prevalent, such as chronic inflammation. In this study, we examine the reactivity of HOCl with a mixture of linker (H1) and core (H2A, H2B, H3 and H4) histones. HOCl modified the histones in a dose- and time-dependent manner, resulting in structural changes to the proteins and the formation of a range of post-translational modification products. N-Chloramines are major products following exposure of the histones to HOCl and decompose over 24 h forming Lys nitriles and carbonyls (aminoadipic semialdehydes). Chlorination and dichlorination of Tyr, but not Trp residues, is also observed. Met sulfoxide and Met sulfones are formed, though these oxidation products are also detected albeit at a lower extent, in the non-treated histones. Evidence for histone fragmentation and aggregation was also obtained. These results could have implications for the development of chronic inflammatory diseases, given the key role of Lys residues in regulating histone function.","pmid":"36152914","doi":"10.1016/j.freeradbiomed.2022.09.016","url":"https://pubmed.ncbi.nlm.nih.gov/36152914/"},{"id":714,"title":"Effects of stabilized hypochlorous acid on oral biofilm bacteria.","authors":"Aherne, Olivia; Ortiz, Roberto; Fazli, Magnus M; Davies, Julia R","year":2022,"date":"2022 Sep 20","journal":"BMC oral health","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: Caries and periodontitis are amongst the most prevalent diseases worldwide, leading to pain and loss of oral function for those affected. Prevention relies heavily on mechanical removal of dental plaque biofilms but for populations where this is not achievable, alternative plaque control methods are required. With concerns over undesirable side-effects and potential bacterial resistance due to the use of chlorhexidine gluconate (CHX), new antimicrobial substances for oral use are greatly needed. Here we have investigated the antimicrobial effect of hypochlorous acid (HOCl), stabilized with acetic acid (HAc), on oral biofilms and compared it to that of CHX. Possible adverse effects of stabilized HOCl on hydroxyapatite surfaces were also examined. METHODS: Single- and mixed-species biofilms of six common oral bacteria (Streptococcus mutans, Streptococcus gordonii, Actinomyces odontolyticus, Veillonella parvula, Parvimonas micra and Porphyromonas gingivalis) within a flow-cell model were exposed to HOCl stabilized with 0.14% or 2% HAc, pH 4.6, as well as HOCl or HAc alone. Biofilm viability was assessed in situ using confocal laser scanning microscopy following LIVE/DEAD® BacLight™ staining. In-situ quartz crystal microbalance with dissipation (QCM-D) was used to study erosion of hydroxyapatite (HA) surfaces by stabilized HOCl. RESULTS: Low concentrations of HOCl (5 ppm), stabilized with 0.14% or 2% HAc, significantly reduced viability in multi-species biofilms representing supra- and sub-gingival oral communities, after 5 min, without causing erosion of HA surfaces. No equivalent antimicrobial effect was seen for CHX. Gram-positive and Gram-negative bacteria showed no significant differential suceptibility to stabilized HOCl. CONCLUSIONS: At low concentrations and with exposure times which could be achieved through oral rinsing, HOCl stabilized with HAc had a robust antimicrobial activity on oral biofilms, without causing erosion of HA surfaces or affecting viability of oral keratinocytes. This substance thus appears to offer potential for prevention and/or treatment of oral biofilm-mediated diseases.","pmid":"36127658","doi":"10.1186/s12903-022-02453-2","url":"https://pubmed.ncbi.nlm.nih.gov/36127658/"},{"id":716,"title":"Group II truncated haemoglobin YjbI prevents reactive oxygen species-induced protein aggregation in Bacillus subtilis.","authors":"Imai, Takeshi; Tobe, Ryuta; Honda, Koji; Tanaka, Mai; Kawamoto, Jun; Mihara, Hisaaki","year":2022,"date":"2022 Sep 20","journal":"eLife","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Oxidative stress-mediated formation of protein hydroperoxides can induce irreversible fragmentation of the peptide backbone and accumulation of cross-linked protein aggregates, leading to cellular toxicity, dysfunction, and death. However, how bacteria protect themselves from damages caused by protein hydroperoxidation is unknown. Here, we show that YjbI, a group II truncated haemoglobin from Bacillus subtilis, prevents oxidative aggregation of cell-surface proteins by its protein hydroperoxide peroxidase-like activity, which removes hydroperoxide groups from oxidised proteins. Disruption of the yjbI gene in B. subtilis lowered biofilm water repellence, which associated with the cross-linked aggregation of the biofilm matrix protein TasA. YjbI was localised to the cell surface or the biofilm matrix, and the sensitivity of planktonically grown cells to generators of reactive oxygen species was significantly increased upon yjbI disruption, suggesting that YjbI pleiotropically protects labile cell-surface proteins from oxidative damage. YjbI removed hydroperoxide residues from the model oxidised protein substrate bovine serum albumin and biofilm component TasA, preventing oxidative aggregation in vitro. Furthermore, the replacement of Tyr(63) near the haem of YjbI with phenylalanine resulted in the loss of its protein peroxidase-like activity, and the mutant gene failed to rescue biofilm water repellency and resistance to oxidative stress induced by hypochlorous acid in the yjbI-deficient strain. These findings provide new insights into the role of truncated haemoglobin and the importance of hydroperoxide removal from proteins in the survival of aerobic bacteria.","pmid":"36125244","doi":"10.7554/eLife.70467","url":"https://pubmed.ncbi.nlm.nih.gov/36125244/"},{"id":717,"title":"Hypochlorous acid produced at the counter electrode inhibits catalase and increases bactericidal activity of a hydrogen peroxide generating electrochemical bandage.","authors":"Anoy, Md Monzurul Islam; Gelston, Suzanne; Mohamed, Abdelrhman; Flurin, Laure; Raval, Yash S; Greenwood-Quaintance, Kerryl; Patel, Robin; Lewandowski, Zbigniew; Beyenal, Haluk","year":2022,"date":"2022 Dec","journal":"Bioelectrochemistry (Amsterdam, Netherlands)","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Previously, an electrochemical bandage (e-bandage) that uses a three-electrode system to produce hydrogen peroxide (H(2)O(2)) electrochemically on its working electrode was developed as a potential strategy for treating biofilms; it showed activity in reducing biofilms in an agar biofilm model. Xanthan gum-based hydrogel, including NaCl, was used as the electrolyte. While H(2)O(2) generated at the working electrode in the vicinity of a biofilm is a main mechanism of activity, the role of the counter electrode was not explored. The goal of this research was to characterize electrochemical reactions occurring on the counter electrode of the e-bandage. Counter electrode potential varied between 1.2 and 1.5 V(Ag/AgCl); ∼125 µM hypochlorous acid (HOCl) was generated within 24 h in the e-bandage system. When HOCl was not produced on the counter electrode (achieved by removing NaCl from the hydrogel), reduction of Acinetobacter baumannii BAA-1605 biofilm was 1.08 ± 0.38 log(10) CFU/cm(2) after 24 h treatment, whereas when HOCl was produced, reduction was 3.87 ± 1.44 log(10) CFU/cm(2). HOCl inhibited catalase activity, abrogating H(2)O(2) decomposition. In addition to H(2)O(2) generation, the previously described H(2)O(2)-generating e-bandage generates HOCl on the counter electrode, enhancing its biocidal activity.","pmid":"36115186","doi":"10.1016/j.bioelechem.2022.108261","url":"https://pubmed.ncbi.nlm.nih.gov/36115186/"},{"id":719,"title":"Reactive silver inks for antiviral, repellent medical textiles with ultrasonic bleach washing durability compared to silver nanoparticles.","authors":"Galante, Anthony J; Pilsbury, Brady C; Yates, Kathleen A; LeMieux, Melbs; Bain, Daniel J; Shanks, Robert M Q; Romanowski, Eric G; Leu, Paul W","year":2022,"date":"2022","journal":"PloS one","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Medical textiles are subject to particularly harsh disinfection procedures in healthcare settings where exposure risks are high. This work demonstrates a fabric treatment consisting of a reactive silver ink and low surface energy PDMS polymer that provides for superhydrophobicity and antiviral properties against enveloped herpes simplex virus stocks even after extended ultrasonic bleach washing. The antiviral properties of reactive silver ink has not been previously reported or compared with silver nanoparticles. The fabric treatment exhibits high static contact angles and low contact angle hysteresis with water, even after 300 minutes of ultrasonic bleach washing. Similarly, after this bleach washing treatment, the fabric treatment shows reductions of infectious virus quantities by about 2 logs compared to controls for enveloped viruses. The use of silver ink provides for better antiviral efficacy and durability compared to silver nanoparticles due to the use of reactive ionic silver, which demonstrates more conformal coverage of fabric microfibers and better adhesion. This study provides insights for improving the wash durability of antiviral silver fabric treatments and demonstrates a bleach wash durable, repellent antiviral treatment for reusable, functional personal protective equipment applications.","pmid":"36103519","doi":"10.1371/journal.pone.0270718","url":"https://pubmed.ncbi.nlm.nih.gov/36103519/"},{"id":721,"title":"Quantitative Measurements of the Depth of Enamel Demineralization before and after Bleach: An In Vitro Study.","authors":"Naim, Sara; Spagnuolo, Gianrico; Osman, Essam; Mahdi, Syed Sarosh; Battineni, Gopi; Qasim, Syed Saad B; Cernera, Mariangela; Rifai, Hasna; Jaafar, Nada; Maalouf, Elie; Zogheib, Carina Mehanna","year":2022,"date":"2022","journal":"BioMed research international","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVE: This study is aimed at determining two main points. First, if the Canary System™ (CS), initially used to assess caries, can measure a decalcification depth of bleached enamel quantitatively, and second, whether or not whitening has a harmful effect on enamel. This device can be considered a useful tool in the clinical assessment of the progression of demineralization after bleaching. MATERIALS AND METHODS: This study collected sixty human premolars that are in a good state recently extracted for orthodontic reason. To properly disinfect and preserve the premolars, they were stored in a saline solution and later in distilled water for a period of two weeks to allow the premolars to rehydrate. Later, 24 hours before the experiment, the premolars were introduced into a solution of artificial saliva to acquire back their minerals. The mineral content of the teeth was measured by the Canary System™ before bleaching. The teeth were bleached with 30% hydrogen peroxide (fläsh HP 30%), 30 min per week and for 3 consecutive weeks to simulate the conditions of strong bleaching in the clinic. The extent of demineralized enamel was measured by the Canary System™ at three points on the enamel surface of each tooth. The data were averaged for each application of the bleaching product. The demineralization extent of the teeth was measured by the Canary System™ before and after bleaching. The significance level was set at 0.05, and SPSS version 26 was used. The data were analyzed by using Wilcoxon's and Student's tests. RESULTS: Mineral loss occurred after the first bleaching session; the Canary System™ detected a decalcification in the first bleaching session (532 ± 322 μm) compared to the other sessions (p ≤ 0.05), while no significant change was detected between the second and the third sessions (p > 0.05). CONCLUSION: Based on the findings of the present study, under in vitro conditions, it was possible to measure the demineralization extent of bleached enamel with the Canary System™.","pmid":"36065254","doi":"10.1155/2022/2805343","url":"https://pubmed.ncbi.nlm.nih.gov/36065254/"},{"id":722,"title":"Decontamination efficacy of common liquid disinfectants against non-spore-forming biological agents in soil matrices.","authors":"Richter, William R; Sunderman, Michelle M; Fulton, Megan L; Willenberg, Zachary; Serre, Shannon; Oudejans, Lukas; Wood, Joseph; Calfee, Michael W","year":2022,"date":"2022 Dec","journal":"Journal of applied microbiology","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"AIMS: The purpose of this study was to evaluate decontamination efficacy, within three soil types, against Yersinia pestis, Burkholderia pseudomallei, and the Venezuelan Equine Encephalitis virus (VEEV). METHODS AND RESULTS: One of three liquid disinfectants (dilute bleach, Virkon-S or Klozur One) was added to three soil types (sand, loam, or clay) and allowed contact for four pre-spike durations: 0, 15, 30 and 60 min. Y. pestis, B. pseudomallei, or VEEV was then spiked into the soil (10 microliters or approx. 1 × 10(7) CFU or PFU into 1 g soil) and decontamination efficacy assessed at post-spike contact times of 10 or 60 min at ambient environmental conditions. Across all soil types, sandy soil resulted in the least quenching to all three disinfectants tested as shown by sustained decontamination efficacy across all pre-spike and post-spike timepoints. Clay and loam soil types exhibited quenching effects on the hypochlorite and peroxygen based disinfectants (dilute bleach and Virkon S) and in general resulted in decreased efficacy with increased pre-spike contact time. The sodium persulfate (Klozur One) performance was the most consistent across all soil types and pre-spike contact times, resulting in greater efficacy with increased post-spike time. CONCLUSIONS: Liquid disinfectants can provide high levels of decontamination in soil for both viral and non-spore-forming bacterial select agents. Hypochlorite and peroxygen based disinfectants used in soils containing higher organic content (loam or clay) may require extended contact times or re-application of liquid disinfectant, in as little as 15 min of application, to achieve a 6-log reduction. SIGNIFICANCE AND IMPACT OF THE STUDY: These results provide information for the performance of three disinfectants in soil against non-spore-forming select agents. These data may aid response decision makers following a biological contamination incident by informing the selection of disinfectant as well as the re-application time to achieve effective site remediation.","pmid":"36056613","doi":"10.1111/jam.15802","url":"https://pubmed.ncbi.nlm.nih.gov/36056613/"},{"id":725,"title":"Chloride Enhances DNA Reactivity with Chlorine under Conditions Relevant to Water Treatment.","authors":"Szczuka, Aleksandra; Horton, Jordon; Evans, Kelsey J; DiPietri, Vincent T; Sivey, John D; Wigginton, Krista R","year":2022,"date":"2022 Sep 20","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Free available chlorine (FAC) is widely used to inactivate viruses by oxidizing viral components, including genomes. It is commonly assumed that hypochlorous acid (HOCl) is the chlorinating agent responsible for virus inactivation; however, recent studies have underscored that minor constituents of FAC existing in equilibrium with HOCl, such as molecular chlorine (Cl(2)), can influence FAC reactivity toward select organic compounds. This study measures the FAC reaction kinetics with dsDNA and ssDNA extracted from representative bacteriophages (T3 and ϕX174) in samples augmented with chloride. Herein, chloride enhances FAC reactivity toward dsDNA and, to a lesser extent, toward ssDNA, especially at pH < 7.5. The enhanced reactivity can be attributed to the formation of Cl(2). Second-order rate constants were determined for reactions of ssDNA and dsDNA with HOCl and Cl(2). DNA chlorination kinetics followed the reactivity-selectivity principle, where the more-reactive nucleophilic species (ssDNA, ∼100× more reactive than dsDNA) reacted less selectively with electrophilic FAC species. The addition of chloride was also shown to enhance the inactivation of bacteriophage T3 (dsDNA genome) by FAC but did not enhance the inactivation of bacteriophage ϕX174 (ssDNA genome). Overall, the results suggest that Cl(2) is an important chlorinating agent of nucleic acids and viruses.","pmid":"36027047","doi":"10.1021/acs.est.2c03267","url":"https://pubmed.ncbi.nlm.nih.gov/36027047/"},{"id":726,"title":"Altered physical-chemical properties of home bleaching gels after an accelerated stability study and their effects on tooth enamel.","authors":"Sobral-Souza, Danielle Ferreira; Gouveia, Thayla Hellen Nunes; Ortiz, Mariangela Ivette Guanipa; Condeles, André Luís; Junior, José Carlos Toledo; Franz-Montan, Michelle; Aguiar, Flávio Henrique Baggio; Lima, Débora Alves Nunes Leite","year":2022,"date":"2022 Dec","journal":"Clinical oral investigations","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"OBJECTIVES: To investigate the physical-chemical properties of home bleaching gels based on Carbamide Peroxide (CP) and Hydrogen Peroxide (HP) after accelerated stability (AS) and its effects on enamel. MATERIALS AND METHODS: A total of 360 bovine teeth blocks were divided (n = 12): Control, CP10%-Whiteness Perfect, CP10%-Pola Night, HP7.5%-Pola Day, and HP7.5%-White Class Calcium. Microhardness (KHN), roughness (Ra), color (ΔE and ΔE(00)), hardness, compressibility, elasticity, cohesiveness, adhesiveness, weight, pH, and calcium (Ca) quantification in enamel were analyzed without storage of the bleaching gels and after AS at 1 and 3 months. Data of Ca, KHN, and Ra were analyzed through mixed models for repeated measurements and the Tukey-Kramer test. Values of weight, hardness, compressibility, and elasticity were analyzed with two-way ANOVA and Tukey's test. ΔE/ΔE(00) data, cohesiveness, and adhesiveness were analyzed with Kruskal-Wallis and Dunn tests (α = 0.05). RESULTS: Groups subject to AS had lower ΔE and ΔE(00) compared to those without storage. Lower KHN and higher Ra values were found after bleaching treatment in all groups compared to controls. Higher amounts of Ca were found on the first day of evaluation in the gels subject to AS for 3 months, regardless of the bleaching agent used. CONCLUSIONS: Incorrectly stored bleaching gel accentuates adverse effects on enamel. Temperature and humidity interfere directly with the chemical stability of bleaching agents, reducing their properties. CLINICAL RELEVANCE: HP is an unstable oxidizing agent when stored at high temperatures. Therefore, pH becomes more acidic and potentiates the demineralizing effect on enamel.","pmid":"35999386","doi":"10.1007/s00784-022-04683-8","url":"https://pubmed.ncbi.nlm.nih.gov/35999386/"},{"id":739,"title":"Scylla, Charybdis, and navigating antimicrobial action in the neutrophil phagosome.","authors":"Nauseef, William M","year":2022,"date":"2022 Oct","journal":"Journal of leukocyte biology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The text extracted from the initial paragraph of a paper coauthored by Zanvil Cohn, one of the pioneers in the study of leukocyte biology, highlights two phenomena that stimulated investigations of innate immunity in the middle of the last century, namely phagocytosis and intracellular antimicrobial activity. Although many features of phagocytosis have been characterized since that time, fundamental aspects of the antimicrobial action of neutrophils remain unknown. The report by Ashby et al. provides a refined and nuanced look at the interface between an ingested microbe, Staphylococcus aureus, and HOCl generated by the myeloperoxidase (MPO)-H(2) O(2) -chloride system in neutrophil phagosomes and represents a holistic approach to the analysis of bactericidal mechanisms that recognizes contributions from both phagocyte and its ingested prey.","pmid":"35929044","doi":"10.1002/JLB.4CE0422-232R","url":"https://pubmed.ncbi.nlm.nih.gov/35929044/"},{"id":742,"title":"A specific turn-on fluorescence probe for determination of nitazoxanide based on feasible oxidation reaction with hypochlorite: Applying cobalt ferrite nanoparticles for pre-concentration and extraction of its metabolite from real urine samples.","authors":"Abdel-Lateef, Mohamed A; Alzahrani, Eman; Pashameah, Rami Adel; Almahri, Albandary; Abu-Hassan, Ahmed A; El Hamd, Mohamed A; Mohammad, Bassam Shaaban","year":2022,"date":"2022 Sep 20","journal":"Journal of pharmaceutical and biomedical analysis","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Nitazoxanide is an antimicrobial compound that was originally developed as an antiprotozoal drug. Recently nitazoxanide has been identified as broad-spectrum antiviral agent and redirected for the remediation of some respiratory tract viral infections. In this study, the spectrofluorimetric technique has been applied to determine Nitazoxanide (NTX) in tablets or its metabolite, tizoxanide (TZD), in human urine samples. The developed methodology is based on oxidizing NTX (non-fluorescence) into a highly fluorescent product by sodium hypochlorite. The fluorescence emission intensity was measured at 436.5 nm after fluorescence excitation at 362.5 nm. After optimizing all conditions, the analytical procedures and bio-analytical steps were evaluated and validated using ICH and FDA criteria, respectively. The method linearity, LOQ, and LOD values of NTX were 1.0-5.0 µg/mL, 0.434, and 0.143 µg/mL, respectively. The other novelty side of the presented work is the application of cobalt ferrite (CoFe(2)O(4)) nanoparticles (NPs) as a magnetic solid-phase for the pre-concentration and extraction process. The synthesized magnetic nanoparticles were characterized by scanning electron microscope and zeta sizer techniques. Finally, the utilized magnetic nanoparticles exhibited good recovery results for pre-concentration and extraction of NTX or its metabolite from spiked and real human urine samples, respectively.","pmid":"35905532","doi":"10.1016/j.jpba.2022.114941","url":"https://pubmed.ncbi.nlm.nih.gov/35905532/"},{"id":743,"title":"Effect of oral antiseptics on the viral load of SARS-CoV-2: A randomized controlled trial.","authors":"Sevinç Gül, Sema Nur; Dilsiz, Alparslan; Sağlık, İmran; Aydın, Nurten Nur","year":2022,"date":"2022 Jul-Sep","journal":"Dental and medical problems","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"BACKGROUND: In the oral cavity, which plays an important role in the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), it is possible to reduce the viral load of SARS-CoV-2 with antiseptics, thereby minimizing the transmission of the virus during dental procedures. OBJECTIVES: The aim of this study was to clinically evaluate the effect of the hypochlorous acid (HClO) and povidone-iodine (PVP-I) solutions on the oral viral load of SARS-CoV-2. MATERIAL AND METHODS: This randomized controlled trial was conducted on 75 patients hospitalized in the COVID-19 ward of a local hospital. All the patients included in the study were within the first 24 h of hospitalization and the first 5 days of coronavirus disease 2019 (COVID-19) symptoms. The viral load of mouthwash samples was measured with the cycle threshold (Ct) value of SARS-CoV-2 through a realtime reverse transcription polymerase chain reaction (RT-PCR). The patients were divided into 3 groups. The effect on the patient's SARS-CoV-2 viral load was investigated after gargling the mouths and throats for 30 s with HClO, PVP-I and isotonic saline. First, a sample was taken after gargling with isotonic saline, then another sample was taken after gargling for 30 s with a particular antiseptic to determine the viral load of SARS-CoV-2. RESULTS: Comparing the before and after mouthwash samples from all 3 groups, there were no statistically significant differences in the Ct values before and after gargling (p > 0.05). However, there were statistically significant differences in the number of negative samples after the use of HClO and PVP-I, which were positive before gargling (p < 0.05). CONCLUSIONS: In the light of the data obtained in this study, there is insufficient evidence that gargling with HClO or PVP-I reduces viral load. Taken together, these findings imply no role for antiseptics in the transmission of SARS-CoV-2 by the aerosol generated during dental procedures, or more generally, SARS-CoV-2 infection control.","pmid":"35904769","doi":"10.17219/dmp/150831","url":"https://pubmed.ncbi.nlm.nih.gov/35904769/"},{"id":744,"title":"Designing of a high-performance fluorescent small molecule enables dual-mode and ultra-sensitive fluorescence visualizing of HSO(3)(-) and HClO in dried fruit, beverage, and water samples.","authors":"Xu, Zi Yi; Wu, You; Wang, Xiao Hu; Chen, Jing Rong; Luo, Hong Qun; Li, Nian Bing","year":2022,"date":"2022 Dec 15","journal":"Food chemistry","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Herein, a novel hemicyanine derivative (E)-3-(1,1-dimethyl-2-(4-(methylthio)styryl)-1H-benzo[e]indol-3-ium-3-yl)propane-1-sulfonate (BIS) has been reasonably designed. Compound BIS is long-wavelength emissive and water-soluble with a large Stokes shift. Intriguingly, probe BIS provides a dual-mode fluorescence response pattern for the sensing of bisulfite (HSO(3)(-)) and hypochlorous acid (HClO) with great limit of detections (3.6 and 57.4 nM). First, the 1,4-Michael addition of HSO(3)(-) on the conjugated double bond triggers a ratiometric response (I(465)/I(575)). Second, the rapid oxidation of HClO on the thioether moiety provides a turn-on response (I(575)). Evaluation of HSO(3)(-) and HClO levels in dried fruit, beverage, and water samples has been carried out with satisfactory results. Moreover, motivated by an impressive chromatic variation (red to blue), smartphone-assisted signal readout system and thin-film sensing platform are facilely constructed for real-time and on-site measurement of HSO(3)(-) levels. Furthermore, probe BIS is used for the in vivo imaging of HSO(3)(-) in edible fish models.","pmid":"35882164","doi":"10.1016/j.foodchem.2022.133754","url":"https://pubmed.ncbi.nlm.nih.gov/35882164/"},{"id":745,"title":"Aggregation-Induced Emission Fluorophore-Incorporated Curcumin-Based Ratiometric Nanoprobe for Hypochlorite Detection in Food Matrices.","authors":"Shen, Yizhong; Nie, Chao; Zhu, Chunlei; Zheng, Zhi; Wu, Yongning","year":2022,"date":"2022 Aug 3","journal":"Journal of agricultural and food chemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The development of efficient, economic, reliable, and accurate monitoring of hypochlorite (ClO(-)) in food matrices is in great demand for food safety assessment, particularly during its massive use against the COVID-19 epidemic. Here, we prepared an aggregation-induced emission (AIE) fluorophore tetraphenylethylene (TPE)-incorporated curcumin-based hybrid ratiometric fluorescence nanoprobe (Curcumin/TPE@HyNPs) through amphiphilic phospholipid polymer-powered nanoprecipitation, which exhibited a fast, highly sensitive, and selective response to the residual ClO(-) in real food matrices. Because of the inner filter effect (IFE) from curcumin toward TPE inside the nanoprobe, the bright fluorescence of TPE aggregation at ∼437 nm was effectively quenched, along with an enhanced fluorescence of curcumin at ∼478 nm. Once there was a ClO(-) residue in food matrices, ClO(-) triggered the oxidation of o-methoxyphenol inside curcumin and led to the almost complete absorption collapse, thereby terminating curcumin fluorescence at ∼478 nm and the IFE process. Accordingly, the fluorescence of TPE at ∼437 nm was recovered. In this case, a ratiometric fluorescent response of Curcumin/TPE@HyNPs toward the residual ClO(-) in food matrices (e.g., milk) was proposed with a low detection limit of 0.353 μM and a rapid response time of 140.0 s. Notably, the phospholipid polymer as the protection layer effectively reduced/evaded the nonspecific binding of signal reporters inside the nanoprobe, facilitating it to directly monitor the residual ClO(-) in real food matrices. This work provided a novel approach to utilize the unconventional AIE luminophors for constructing the efficient and reliable early warning mechanisms toward various food contaminants.","pmid":"35876793","doi":"10.1021/acs.jafc.2c03826","url":"https://pubmed.ncbi.nlm.nih.gov/35876793/"},{"id":747,"title":"Whitening efficacy of low concentration hydrogen peroxide photoactivated with blue or violet LED.","authors":"Costa, Joatan Lucas de Sousa Gomes; Besegato, João Felipe; Zaniboni, Joissi Ferrari; Vitória, Matheus Sousa; Gelio, Mariana Bena; Kuga, Milton Carlos","year":2022,"date":"2022 Sep","journal":"Photodiagnosis and photodynamic therapy","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"BACKGROUND: Bleaching protocols using low concentration hydrogen peroxide (HP) photoactivated with LED sources have been widely discussed. Herein, we evaluated the whitening efficacy of 15% HP photoactivated with blue or violet LED compared to 35% HP. METHODS: Thirty bovine crowns were sectioned into 5 × 5 × 2 mm specimens. After staining in black tea, the specimens were randomized into three groups (n = 10): 35% HP, 15% HP + blue LED and 15% HP + violet LED. Two bleaching sessions were performed and the color assessment (∆L*, ∆a*, ∆b*, ∆E(ab) [CIELab], ∆E(00) [CIEDE2000] and WI(D)) was performed before, 24h after each session, 7 days and 1 month after the last session. Data were evaluated by two-way repeated measures ANOVA and Bonferroni post-test at a significance level of 5%. RESULTS: All groups showed effective and similar results over 1 month of follow-up (p > 0.05), with only intragroup differences among the time intervals (p < 0.05). CONCLUSIONS: The use of 15% HP photoactivated with blue or violet LED showed similar whitening efficacy compared to 35% HP. Thus, the association of low concentration bleaching gels with blue or violet LED sources can provide successful and less-aggressive treatment in terms of color change.","pmid":"35872355","doi":"10.1016/j.pdpdt.2022.103028","url":"https://pubmed.ncbi.nlm.nih.gov/35872355/"},{"id":748,"title":"The effect of hypochlorous acid on the filtration performance and bacterial decontamination of N95 filtering facemask respirators.","authors":"Brooks, J Patrick; Lupfer, Christopher; Yang, Wang; Hao, Weixing; Kapiamba, Kashala Fabrice","year":2023,"date":"2023 Apr","journal":"American journal of infection control","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: Stabilized hypochlorous acid (HOCl) is increasingly used as a hospital disinfectant and antiseptic, yet its effect on N95 filtration facemask respirators (FFR) is unknown. These FFRs could also contribute to fomite-based transmission of nosocomial infections if worn for extended use between patient rooms. METHODS: Filtration performance of N95 FFR fabric swatches was assessed after various levels of HOCl exposure. N95 swatches were then contaminated with 10(8)Escherichia coli or 10(8)Staphylococci aureus and treated with HOCl solution, 70% ethyl alcohol, or normal saline. Surviving bacterial numbers were assessed by plate counts. RESULTS: The size-dependent filtration efficiency of HOCl-sprayed N95 FFR fabric ranged from 96% to 100%, showing no significant change. Flow resistance testing revealed almost no change compared to control. Submersion in HOCl, but not spraying, had an excellent bactericidal effect on contaminated swatches. DISCUSSION: The role of the outer hydrophobic layer of N95 FFRs is discussed regarding the effects of HOCl on filtration and bacterial decontamination. CONCLUSIONS: N95 material, sprayed with or briefly submerged in HOCl, maintained its filtration function. HOCl delivery by spray pump, however, would not accomplish decontamination of extended use FFRs between patient encounters. HOCl submersion of intact FFRs, contaminated with various hospital pathogens, is worth further study.","pmid":"35870660","doi":"10.1016/j.ajic.2022.07.013","url":"https://pubmed.ncbi.nlm.nih.gov/35870660/"},{"id":749,"title":"Hypochlorous acid and white vinegar: Artifact-free COVID-19 disinfection options for photostimulable storage phosphor plates.","authors":"Pamukcu, Umut; Peker, Ilkay","year":2022,"date":"2022 Sep","journal":"Oral surgery, oral medicine, oral pathology and oral radiology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"OBJECTIVES: To examine the artifacts on intraoral photostimulable storage phosphor (PSP) plate images caused by 3 different disinfectants that are effective against pathogens including SARS-CoV-2. STUDY DESIGN: Nine new PSP plates, to be wiped with hypochlorous acid (HOCl) in group A, alcohol in group B, and white vinegar in group C, were distributed in 3 groups. Twelve images of each PSP plate with increasing numbers of wipes were examined for artifacts. The comparisons were evaluated by Kruskal-Wallis and post hoc tests. The reliability of the measurements was evaluated using the intraclass correlation coefficient (ICC) and Cohen kappa statistic. RESULTS: Artifacts were observed only on group B images. In terms of artifact scores, the difference between group A and group C was not statistically significant (P > .05), whereas group B artifact scores were significantly higher than group A and group C (P < .05). Intraobserver reliability was perfect (ICC and kappa of 1.0) and interobserver reliability was considered excellent (ICC = 0.985) or almost perfect (kappa = 0.956). CONCLUSIONS: HOCl and white vinegar can be alternative disinfection options for PSP plates tested in this study. Unlike alcohol, they did not produce artifacts. Additional research evaluating their effects on image quality is needed to determine if they are appropriate for disinfection.","pmid":"35869016","doi":"10.1016/j.oooo.2022.03.003","url":"https://pubmed.ncbi.nlm.nih.gov/35869016/"},{"id":754,"title":"Kinetics and mechanism of the reaction of hydrogen peroxide with hypochlorous acid: Implication on electrochemical water treatment.","authors":"Lu, Xiaohui; Zhou, Xiaoqun; Qiu, Wei; Wang, Ziyue; Wang, Yishi; Zhang, Haochen; Yu, Jiaxin; Wang, Da; Gu, Jia; Ma, Jun","year":2022,"date":"2022 Sep 15","journal":"Journal of hazardous materials","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Reduction of HOCl to Cl(-) by in-situ electrochemical synthesis or ex-situ addition of H(2)O(2) is a feasible method to minimize Cl-DBPs and ClO(x)(-) (x = 2, 3, and 4) formation in electrochemical oxidative water treatment systems. This work has investigated the kinetics and mechanism of the reaction between H(2)O(2) and HOCl. The kinetics study showed the species-specific second order rate constants for HOCl with H(2)O(2) (k(1)), HOCl with HO(2)(-) (k(2)) and OCl(-) with H(2)O(2) (k(3)) are 195.5 ± 3.3 M(-1)s(-1), 4.0 × 10(7) M(-1)s(-1) and 3.5 × 10(3) M(-1)s(-1), respectively. The density functional theory calculation showed k(2) is the most advantageous thermodynamically pathway because it does not need to overcome a high energy barrier. The yields of (1)O(2) generation from the reaction of H(2)O(2) with HOCl were reinvestigated by using furfuryl alcohol (FFA) as a probe, and an average of 92.3% of (1)O(2) yields was obtained at pH 7-12. The second order rate constants of the reaction of (1)O(2) with 13 phenolates were determined by using the H(2)O(2)/HOCl system as a quantitative (1)O(2) production source. To establish a quantitative structure activity relationship, quantum chemical descriptors were more satisfactory than empirical Hammett constants. The potential implications in electrochemical oxidative water treatment were discussed at the end.","pmid":"35816805","doi":"10.1016/j.jhazmat.2022.129420","url":"https://pubmed.ncbi.nlm.nih.gov/35816805/"},{"id":755,"title":"Three-Dimensional Quantitative Structure and Activity Relationship of Flavones on Their Hypochlorite Scavenging Capacity.","authors":"Yang, Xin; Wang, Tian; Žuvela, Petar; Sun, Mingtai; Xu, Chunyuhang; Zheng, Hongling; Wang, Xiang; Jing, Linzhi; Du, Ke; Wang, Suhua; Wong, Ming Wah; Huang, Dejian","year":2022,"date":"2022 Jul 20","journal":"Journal of agricultural and food chemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Flavonoids, a class of polyphenolic substances widely present in the plant realm, are considered as ideal hypochlorite scavengers. However, to our knowledge, little study has focused on the structure-activity relationship between flavonoids and hypochlorite scavenging capacity. Herein, we report for the first time the three-dimensional quantitative structure and activity relationship (3D-QSAR) combined with comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). Four models derived from CoMFA and CoMSIA with different combinations of descriptors were built and compared; the CoMFA model, which included both steric and electrostatic fields, showed great potential (R(2) = 0.989; Q(2) = 0.818) in predictive quality according to both internal and external validation criteria. Additionally, the average local ionization energy (ALIE), electrostatic potential (ESP), and orbital weighted dual descriptor (OWDD) were determined to identify the key structural moiety for scavenging capacity of flavonoids against hypochlorite. The computational results indicated that hypochlorous acid (HClO) serves as an electrophile undergoing electrophilic addition to the C6 carbon, which has the highest negative charge density, which are influenced by the functional groups on the flavones. The DFT calculated mechanism revealed the catalytic role of water of mono- and di-chlorination reactions, characterized by low activation barriers, and the involvement of neutral, instead of high-energy carbocation, intermediates.","pmid":"35815596","doi":"10.1021/acs.jafc.2c03860","url":"https://pubmed.ncbi.nlm.nih.gov/35815596/"},{"id":758,"title":"Effects of an amino acid buffered hypochlorite solution as an adjunctive to air-powder abrasion in open-flap surface decontamination of implants failed for peri-implantitis: an ex vivo randomized clinical trial.","authors":"La Monaca, Gerardo; Pranno, Nicola; Mengoni, Fabio; Puggioni, Gianluca; Polimeni, Antonella; Annibali, Susanna; Cristalli, Maria Paola","year":2023,"date":"2023 Feb","journal":"Clinical oral investigations","category":"Water, sanitation & biosecurity","evidence":"Randomized controlled trial","relevance":"High","abstract":"OBJECTIVES: To evaluate ex vivo the efficacy of an amino acid buffered hypochlorite solution supplemented to surface debridement with air-powder abrasion in removing bacterial biofilm following open-flap decontamination of implants failed due to peri-implantitis. MATERIALS AND METHODS: This study was an ex vivo, single-blind, randomized, intra-subject investigation. Study population consisted of 20 subjects with at least three implants failed for peri-implantitis (in function for > 12 months and progressive bone loss exceeding 50%) to be explanted. For each patient, implants were randomly assigned to surface decontamination with sodium bicarbonate air-powder abrasion (test-group 1) or sodium bicarbonate air-powder abrasion supplemented by amino acid buffered hypochlorite solution (test-group 2) or untreated control group. Following open-flap surgery, untreated implants (control group) were explanted. Afterwards, test implants were decontaminated according to allocation and explanted. Microbiological analysis was expressed in colony-forming units (CFU/ml). RESULTS: A statistically significant difference in the concentrations of CFU/ml was found between implants of test-group 1 (63,018.18 ± 228,599.36) (p = 0.007) and implants of test-group 2 (260.00 ± 375.80) (p < 0.001) compared to untreated implants (control group) (86,846.15 ± 266,689.44). The concentration of CFU/ml on implant surfaces was lower in test-group 2 than in test-group 1, with a statistically significant difference (p < 0.001). CONCLUSION: The additional application of amino acid buffered hypochlorite solution seemed to improve the effectiveness of implant surface decontamination with air-powder abrasion following open-flap surgery. CLINICAL RELEVANCE: Lacking evidence on the most effective method for biofilm removal from contaminated implant surfaces, the present experimental study provides further information for clinicians and researchers.","pmid":"35802191","doi":"10.1007/s00784-022-04608-5","url":"https://pubmed.ncbi.nlm.nih.gov/35802191/"},{"id":762,"title":"Hypochlorous Acid-Activated Multifunctional Fluorescence Platform for Depression Therapy and Antidepressant Efficacy Evaluation.","authors":"Wang, Xin; Wang, Ruiyuan; Ding, Qi; Wu, Wei; Che, Feida; Li, Ping; Zhang, Wen; Zhang, Wei; Liu, Zhenzhen; Tang, Bo","year":2022,"date":"2022 Jul 12","journal":"Analytical chemistry","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Current diagnosis of depression rests on the symptoms, so it still lacks objective criteria. Meanwhile, existing treatment of depression is dominated by antidepressants, which produce troublesome side effects and usually require months to achieve effect. Therefore, more reliable diagnostic criteria and effective therapy are urgently needed. Some core hallmarks in the etiology of depression have been established, including declined neurotransmitters and inflammatory responses, manifesting in oxidative stress. Thus, we fabricated a HClO-triggered multifunctional fluorescence platform (MB-Rs) for simultaneous neurotransmitter/antidepressant delivery and efficacy evaluation. In MB-Rs, although a urea linkage could be specifically cut off by HClO, methylene blue (MB) endowed with excellent anti-inflammatory and optical properties was covalently linked with neurotransmitters (dopamine or 5-hydroxytryptamine) or antidepressants (fluoxetine). Encountering excess HClO in the brain of mice with depression, MB-Rs released corresponding antidepressants and MB with anti-inflammatory and bright fluorescence. By relieving oxidative stress, inflammation, and coinstantaneous increasing neurotransmitters, MB-Rs elicited better antidepressant response and fewer side effects compared with clinical antidepressants. Furthermore, MB-Rs successfully evaluated the efficacy of antidepressants in mice based on HClO-induced fluorescence. Therefore, this work provides a promising platform for depression diagnosis and treatment.","pmid":"35763564","doi":"10.1021/acs.analchem.2c01639","url":"https://pubmed.ncbi.nlm.nih.gov/35763564/"},{"id":765,"title":"Effect of Hypochlorites on the Compressive Strength and Surface Hardness of Type V Dental Stone: An In Vitro Study.","authors":"Nautiyal, Mansi; Jyothi, K S; Muttagi, Seshagiri; Pallavi, N T; D'Almeida, Avita Uh; Shah, Chintan P; Kaur, Harsimran; Singh, Nishtha","year":2022,"date":"2022 Feb 1","journal":"The journal of contemporary dental practice","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"AIM: The study aimed to evaluate the compressive strength and surface hardness of a type V dental stone after hypochlorite disinfection. MATERIALS AND METHODS: Two types of specimens were made according to the American Dental Association (ADA) specification no. 25 for each wet compressive strength, dry compressive strength, and surface hardness. The specimens were split into three groups with 30 samples each according to the type of disinfection. All specimens were immersed in their respective disinfecting solutions for 30 minutes at room temperature and after removal, they were left to dry for 24 hours at room temperature. Total five cycles of immersion and drying were followed. A compressive strength test was done using a universal testing machine. Wet compressive strength was tested one hour after the last cycle and dry compressive strength was tested 7 days after the last cycle. Surface hardness was measured after 48 hours using Vickers hardness test. The results were statistically analyzed. RESULTS: There was a statistical difference between the calcium hypochlorite and sodium hypochlorite groups for both dry and wet compressive strength. The mean wet compressive strength of calcium hypochlorite was higher when compared to the sodium hypochlorite group and it was statistically significant (p = 0.042). The results were similar and statistically significant (p = 0.003) for dry compressive strength. When the mean surface hardness of the sodium hypochlorite (A(s)) group was compared to calcium hypochlorite the results were highly significant (p = 0.0001) with the mean surface hardness of the calcium hypochlorite group more than the sodium hypochlorite group. CONCLUSION: Calcium hypochlorite used as a disinfectant showed better compressive strength and surface hardness when compared to sodium hypochlorite as a disinfectant. CLINICAL SIGNIFICANCE: Dental casts poured in the contaminated impressions which might not be disinfected at all or properly. They also come in contact with the prosthesis that might be tried inside the patient's mouth and sent to a lab for corrections without disinfecting the cast causing cross-contamination between patients, dentists, and laboratory personnel. However, immersion disinfection with sodium or calcium hypochlorite might affect important properties of the cast. Any negative effect on the mechanical or physical properties of the cast will affect the final outcome of the prosthesis.","pmid":"35748452","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/35748452/"},{"id":766,"title":"A fluorescence digital image-based method using carbon quantum dots to evaluate the compliance of a biocidal agent.","authors":"de Almeida, João Paulo Barbosa; Dos Santos, Vagner Bezerra; do Nascimento, Gustavo Alves; Suarez, Willian Toito; de Azevedo, Walter Mendes; Ferreira, Aldebarã Fausto; Maia, Matheus Valentin","year":2022,"date":"2022 Jul 7","journal":"Analytical methods : advancing methods and applications","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"In this work, a simple, low-cost and easy-to-handle analytical procedure based on carbon quantum dots (CQDs) is proposed to check commercially available formulated microbicides that are used to mitigate the transmission of viruses, such as SARS-COV-2, or bacterial diseases. For this purpose, CQDs were synthesized via pyrolysis using citric acid and ethylenediamine as precursors to produce an intense fluorescence that is used to measure the concentration of hypochlorite, an important biocidal agent present in sanitizing mats, by quenching mechanisms. The characterization of the CQDs was performed using IR spectrophotometry, UV-Vis spectrophotometry, spectrofluorometry, thermogravimetric analysis, scanning electron microscopy, dynamic light scattering, X-ray diffraction, energy-dispersive spectroscopy, and zeta potential measurements. For analytical purposes, fluorescence was measured in a UV chamber irradiated using an LED with the maximum emission at 350 nm. A smartphone was coupled to the UV chamber to measure the fluorescence quenching due to the presence of hypochlorite, and further the digital images were decomposed by RGB data using free software. Tests of pH, CQD concentration and stability of the fluorescence emitted were performed. The stability study of the fluorescence emitted by the CQD solution showed a relative standard deviation lower than 5.0%. The fluorescence digital image-based (FDIB) method resulted in a linear range from 17.44 μmol L(-1) to 90.0 μmol L(-1) with an LOD of 3.30 μmol L(-1) for the determination of hypochlorite using a microplate made of PLA (polylactic acid) customized using a 3D printer. Furthermore, the hypochlorite concentration was tested in situ for its compliance in a sanitizing mat, in a real use situation (daily, a group of four people, each one kept their feet on the mat for 30 s). After 2.5 h, the monitored concentration of hypochlorite was 0.04953% (w/v) or 7.63 mmol L(-1), and therefore, it was inefficient to act as a sanitizing agent. Thus, for the first time in the literature, an FDIB method with CQDs is used to verify in situ microbicide practices with a fast and low-cost analytical procedure.","pmid":"35736378","doi":"10.1039/d2ay00678b","url":"https://pubmed.ncbi.nlm.nih.gov/35736378/"},{"id":769,"title":"Influence of plasma halide, pseudohalide and nitrite ions on myeloperoxidase-mediated protein and extracellular matrix damage.","authors":"Xu, Shuqi; Chuang, Christine Y; Malle, Ernst; Gamon, Luke F; Hawkins, Clare L; Davies, Michael J","year":2022,"date":"2022 Aug 1","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase (MPO) mediates pathogen destruction by generating the bactericidal oxidant hypochlorous acid (HOCl). Formation of this oxidant is however associated with host tissue damage and disease. MPO also utilizes H(2)O(2) to oxidize other substrates, and we hypothesized that mixtures of other plasma anions, including bromide (Br(-)), iodide (I(-)), thiocyanate (SCN(-)) and nitrite (NO(2)(-)), at normal or supplemented concentrations, might modulate MPO-mediated HOCl damage. For the (pseudo)halide anions, only SCN(-) significantly modulated HOCl formation (IC(50) ∼33 μM), which is within the normal physiological range, as judged by damage to human plasma fibronectin or extracellular matrix preparations detected by ELISA and LC-MS. NO(2)(-) modulated HOCl-mediated damage, in a dose-dependent manner, at physiologically-attainable anion concentrations. However, this was accompanied by increased tyrosine and tryptophan nitration (detected by ELISA and LC-MS), and the overall extent of damage remained approximately constant. Increasing NO(2)(-) concentrations (0.5-20 μM) diminished HOCl-mediated modification of tyrosine and methionine, whereas tryptophan loss was enhanced. At higher NO(2)(-) concentrations, enhanced tyrosine and methionine loss was detected. These analytical data were confirmed in studies of cell adhesion and metabolic activity. Together, these data indicate that endogenous plasma levels of SCN(-) (but not Br(-) or I(-)) can modulate protein modification induced by MPO, including the extent of chlorination. In contrast, NO(2)(-) alters the type of modification, but does not markedly decrease its extent, with chlorination replaced by nitration. These data also indicate that MPO could be a major source of nitration in vivo, and particularly at inflammatory sites where NO(2)(-) levels are often elevated.","pmid":"35718304","doi":"10.1016/j.freeradbiomed.2022.06.222","url":"https://pubmed.ncbi.nlm.nih.gov/35718304/"},{"id":771,"title":"Impact of disinfectants on the intestinal bacterial symbionts and immunity of silkworm (Bombyx mori L.).","authors":"Li, Guannan; Cai, Miao; Zheng, Xi; Xie, Xiaofan; Zhu, Yong; Long, Yaohang","year":2022,"date":"2022 Nov","journal":"Environmental science and pollution research international","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"The insect egg surface can serve as a vehicle for vertical symbiont transmission from the maternal parent to its offspring. Hypochlorite and formaldehyde are two common disinfectants used for insect egg surface sterilization. Here, we explored the intestinal microecology and immune response profile of the silkworm Bombyx mori strain Dazao after disinfectant exposure by using high-throughput sequencing technology and real-time PCR analysis. After egg surface sterilization, no significant difference (P > 0.05) in overall body weight was observed among the control, sodium hypochlorite, and formaldehyde groups. 16S rRNA metagenomic sequencing revealed that the main abundant intestinal bacteria were Enterococcus, Burkholderia, Phenylobacterium, Ralstonia, Chitinophaga, Bradyrhizobium, Herbaspirillum, and two unclassified Bacteroidetes species. Egg surface sterilization evidently altered the composition and abundance of intestinal microbiota but did not significantly change its alpha diversity. The dysbiosis of intestinal microbiota resulted in the perturbation of the immune response profile of the silkworm intestine. Our findings reveal that hypochlorite has a blocking effect on the symbiont transmission compared with formaldehyde. More importantly, egg surface sterilization exerts substantial effects on the ecophysiological traits of insects. The present study contributes to the scientific and reasonable application of disinfectants for insect egg surface sterilization during industrial silk production and laboratory-scale insect rearing.","pmid":"35713834","doi":"10.1007/s11356-022-21442-0","url":"https://pubmed.ncbi.nlm.nih.gov/35713834/"},{"id":772,"title":"Tetraphenylethylene-thiosemicarbazone based ultrafast, highly sensitive detection of hypochlorite in aqueous environments and dairy products.","authors":"Erdemir, Eda; Suna, Garen; Gunduz, Simay; Şahin, Musa; Eğlence-Bakır, Songül; Karakuş, Erman","year":2022,"date":"2022 Jul 25","journal":"Analytica chimica acta","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"We have designed and synthesised a novel fluorescent probe with a tetraphenylethylene (TPE) scaffold as an active fluorescent unit and thiosemicarbazide (TSC) group as a recognition unit. The probe, TPE-TSC, exhibited superior selectivity towards hypochlorite (ClO(-)) with a low limit of detection (2.0 nM). It also demonstrated a turn-off response for a brief period (<30 s) via an oxidation reaction. Furthermore, high-resolution mass spectrometry (HRMS) revealed that TPE-TSC reacted with ClO(-) by forming a carboxylic acid moiety in nearly 100% aqueous environments. More significantly, the probe detected ClO(-) in disinfectant, spiked milk samples, and spiked water samples. In all, TPE-TSC proposes an optimistic approach precisely for the determining the quality of milk and water contaminated with ClO(-) and trace amounts of ClO(-) in disinfectants.","pmid":"35701038","doi":"10.1016/j.aca.2022.340029","url":"https://pubmed.ncbi.nlm.nih.gov/35701038/"},{"id":775,"title":"Nitrogen doped carbon quantum dots (N-CQDs) with high luminescence for sensitive and selective detection of hypochlorite ions by fluorescence quenching.","authors":"Qi, Hongxia; Zhai, Zizhuo; Dong, Xipeng; Zhang, Pudun","year":2022,"date":"2022 Oct 15","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"A highly luminescent nitrogen-doped carbon quantum dots (N-CQDs) with a quantum yield of 44% was prepared by a facile hydrothermal synthesis method using citric acid (CA) and ethylenediamine (EDA) with a molar ratio of 1:1 at 200 °C for 5 h. The hypochlorite (ClO(-)) ions significantly quench the fluorescence of the N-CQDs according to a pseudo-second-order kinetic model. A sensitive and selective quantification method with an excellent linearity in the range of 1.0-10.0 μM was developed to detect ClO(-) ions based on the fluorescence quenching. The limit of detection (LOD) of 0.43 μM and the limit of quantification (LOQ) of 1.04 μM were achieved, respectively. This approach was successfully applied to detect the residual ClO(-) ions in local tap water and in swimming pool water. In addition, the developed fluorescence quenching method was also successfully applied in anti-counterfeiting and paper encryption. Both of the applications in real world suggest that the as-prepared N-CQDs is a kind of promising fluorescence probe for rapid detecting ClO(-) ions in environment fields, and has potential applications in text secrecy fields.","pmid":"35687990","doi":"10.1016/j.saa.2022.121456","url":"https://pubmed.ncbi.nlm.nih.gov/35687990/"},{"id":776,"title":"Rational construction of deep-red fluorescent probe for rapid detection of HClO and its application in bioimaging and paper-based sensing.","authors":"Fang, Xingliang; Jin, Xilang; Ma, Xuehao; Guan, Li; Chen, Weixing; She, Mengyao","year":2022,"date":"2022 Aug","journal":"Analytical and bioanalytical chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HClO), the core bactericidal substance of the human immune system, plays a vital role in many physiological and pathological processes in the human body. In this work, we designed and synthesized a novel deep-red fluorescent probe TCF-ClO for the determination of hypochlorous acid through theoretical analysis. The results showed that probe TCF-ClO exhibited excellent characteristics of long-wavelength emission (635 nm), fast response (< 1 min), and low detection limit (24 nM). In addition, it had been successfully used for imaging of HClO in living HeLa cells. More importantly, the TCF-ClO composited paper-based sensing material was successfully constructed. The RGB/gray value was obtained from a mobile phone and computer, which could achieve the quantitative detection of HClO, with a linear detection range of 0-50 μM and a detection limit of 1.09 μM (RGB mode)/3.38 μM (gray mode). The function of the paper-based sensor extended from qualitative to quantitative detection of HClO, and it is expected to become a portable device widely used in the environmental area.","pmid":"35676562","doi":"10.1007/s00216-022-04154-9","url":"https://pubmed.ncbi.nlm.nih.gov/35676562/"},{"id":783,"title":"Oxidation of bacillithiol during killing of Staphylococcus aureus USA300 inside neutrophil phagosomes.","authors":"Ashby, Louisa V; Springer, Reuben; Loi, Vu Van; Antelmann, Haike; Hampton, Mark B; Kettle, Anthony J; Dickerhof, Nina","year":2022,"date":"2022 Oct","journal":"Journal of leukocyte biology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Targeting immune evasion tactics of pathogenic bacteria may hold the key to treating recalcitrant bacterial infections. Staphylococcus aureus produces bacillithiol (BSH), its major low-molecular-weight thiol, which is thought to protect this opportunistic human pathogen against the bombardment of oxidants inside neutrophil phagosomes. Here, we show that BSH was oxidized when human neutrophils phagocytosed S. aureus, but provided limited protection to the bacteria. We used mass spectrometry to measure the oxidation of BSH upon exposure of S. aureus USA300 to either a bolus of hypochlorous acid (HOCl) or a flux generated by the neutrophil enzyme myeloperoxidase. Oxidation of BSH and loss of bacterial viability were strongly correlated (r = 0.99, p < 0.001). BSH was fully oxidized after exposure of S. aureus to lethal doses of HOCl. However, there was no relationship between the initial BSH levels and the dose of HOCl required for bacterial killing. In contrast to the HOCl systems, only 50% of total BSH was oxidized when neutrophils killed the majority of phagocytosed bacteria. Oxidation of BSH was decreased upon inhibition of myeloperoxidase, implicating HOCl in phagosomal BSH oxidation. A BSH-deficient S. aureus USA300 mutant was slightly more susceptible to treatment with either HOCl or ammonia chloramine, or to killing within neutrophil phagosomes. Collectively, our data show that myeloperoxidase-derived oxidants react with S. aureus inside neutrophil phagosomes, leading to partial BSH oxidation, and contribute to bacterial killing. However, BSH offers only limited protection against the neutrophil's multifaceted killing mechanisms.","pmid":"35621076","doi":"10.1002/JLB.4HI1021-538RR","url":"https://pubmed.ncbi.nlm.nih.gov/35621076/"},{"id":786,"title":"A new-type HOCl-activatable fluorescent probe and its applications in water environment and biosystems.","authors":"Wang, Kun; Liu, Yilin; Liu, Caiyun; Zhu, Hanchuang; Li, Xiwei; Yu, Miaohui; Liu, Lunying; Sang, Guoqing; Sheng, Wenlong; Zhu, Baocun","year":2022,"date":"2022 Sep 15","journal":"The Science of the total environment","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The outbreak and spread of Corona Virus Disease 2019 (COVID-19) has led to a significant increase in the consumption of sodium hypochlorite (NaOCl) disinfectants. NaOCl hydrolyzes to produce hypochlorous acid (HOCl) to kill viruses, which is a relatively efficient chlorine-based disinfectant commonly used in public disinfection. While people enjoy the convenience of NaOCl disinfection, excessive and indiscriminate use of it will affect the water environment and threaten human health. Importantly, HOCl is an indispensable reactive oxygen species (ROS) in human body. Whether its concentration is normal or not is closely related to human health. Excessive production of HOCl in the body contributes to some inflammatory diseases and even cancer. Also, we noticed that the concentration of ROS in cancer cells is about 10 times higher than that in normal cells. Herein, we developed a HOCl-activatable biotinylated dual-function fluorescent probe BTH. For this probe, we introduced biotin on the naphthalimide fluorophore, which increased the water solubility and enabled the probe to aggregate in cancer cells by targeting specific receptor overexpressed on the surface of cancer cell membrane. After reacting to HOCl, the p-aminophenylether moiety of this probe was oxidatively removed and the fluorescence of the probe was recovered. As expected, in the PBS solution with pH of 7.4, BTH could give full play to the performance of detecting HOCl, and it has made achievements in detecting the concentration of HOCl in actual water samples. Besides that, BTH had effectively distinguished between cancer cells and normal cells through a dual-function discrimination strategy, which used biotin to enrich the probe in cancer cells and reacted with overexpressed HOCl in cancer cells. Importantly, this dual-function discrimination strategy could obtain the precision detection of cancer cells, thereby offering assistance for improving the accuracy of early cancer diagnosis.","pmid":"35609703","doi":"10.1016/j.scitotenv.2022.156164","url":"https://pubmed.ncbi.nlm.nih.gov/35609703/"},{"id":788,"title":"Impact of agitation/activation strategies on the antibiofilm potential of sodium hypochlorite/etidronate mixture in vitro.","authors":"Cai, Ming; Cai, Yanling; Yang, Ruiqi; Xu, Zhezhen; Neelakantan, Prasanna; Wei, Xi","year":2022,"date":"2022 May 23","journal":"BMC oral health","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"BACKGROUND: To investigate the effect of a rotary agitation method or ultrasonically activated irrigation on the antibiofilm effect of a mixture of sodium hypochlorite (NaOCl) and etidronate (1-hydroxyethylidene-1,1-bisphosphonate, HEBP) using a dual-species biofilm model in root canal system. METHODS: Mature dual-species biofilms of Enterococcus faecalis and Streptococcus gordonii were formed in root canals of mandibular premolars. Teeth were randomly allotted (n = 12) to group 1, XP-endo Finisher (XPF); group 2, ultrasonically activated irrigation (UAI); group 3, syringe-and-needle irrigation (SNI). In all groups, canals were instrumented with a rotary instrument (XP-endo Shaper) prior to irrigant agitation/activation. A mixture containing 2.5% NaOCl and 9% HEBP was used throughout the experiment. Bacterial counts from the canal were determined using qPCR before preparation (S1), after preparation (S2), and after final irrigation agitation/activation (S3). Bacterial viability within the dentinal tubules in the coronal, middle and apical root-thirds was quantified using confocal microscopy after Live/Dead staining. The bacterial counts and viability were compared between groups using one-way ANOVA and post-hoc Tukey's tests. Paired t-test was used to compare the bacterial counts within groups. RESULTS: Instrumentation alone could significantly reduce the microbial counts in all the groups (P < 0.0001). Subsequent agitation/activation resulted in significant microbial reduction only in XPF and UAI (P < 0.05), both of which reduced significantly more microbial counts than SNI (P < 0.05). Live/Dead staining revealed that XPF and UAI showed significantly greater percentage of dead bacteria within the dentinal tubules than SNI in the coronal third (P < 0.05); UAI resulted in the significantly highest percentage of dead bacteria in the middle third (P < 0.05); while there was no significant difference between the groups in the apical third (P > 0.05). CONCLUSIONS: When using the sodium hypochlorite/etidronate mixture for irrigation, final irrigant agitation/activation with XP-endo Finisher or ultrasonic can improve disinfection of the main root canal space and the dentinal tubules in the coronal third, while ultrasonically activated irrigation appears to exhibit better disinfection within dentinal tubules in the middle third.","pmid":"35606751","doi":"10.1186/s12903-022-02222-1","url":"https://pubmed.ncbi.nlm.nih.gov/35606751/"},{"id":790,"title":"An increase in surface hydrophobicity mediates chaperone activity in N-chlorinated RidA.","authors":"Varatnitskaya, Marharyta; Fasel, Julia; Müller, Alexandra; Lupilov, Natalie; Shi, Yunlong; Fuchs, Kristin; Krewing, Marco; Jung, Christoph; Jacob, Timo; Sitek, Barbara; Bandow, Julia E; Carroll, Kate S; Hofmann, Eckhard; Leichert, Lars I","year":2022,"date":"2022 Jul","journal":"Redox biology","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Under physiological conditions, Escherichia coli RidA is an enamine/imine deaminase, which promotes the release of ammonia from reactive enamine/imine intermediates. However, when modified by hypochlorous acid (HOCl), it turns into a potent chaperone-like holdase that can effectively protect E. coli's proteome during oxidative stress. However, it is unknown, which residues need to be chlorinated for activation. Here, we employ a combination of LC-MS/MS analysis, a chemo-proteomic approach, and a mutagenesis study to identify residues responsible for RidA's chaperone-like function. Through LC-MS/MS of digested RidA(HOCl), we obtained direct evidence of the chlorination of one arginine residue. To overcome the instability of the N-chloramine modification, we established a chemoproteomic approach using 5-(dimethylamino) naphthalene-1-sulfinic acid (DANSO(2)H) as a probe to label N-chlorinated lysines. Using this probe, we were able to detect the N-chlorination of six additional lysine residues. Moreover, using a mutagenesis study to genetically probe the role of single arginine and lysine residues, we found that the removal of arginines R105 and/or R128 led to a substantial reduction of RidA(HOCl)'s chaperone activity. These results, together with structural analysis, confirm that the chaperone activity of RidA is concomitant with the loss of positive charges on the protein surface, leading to an increased overall protein hydrophobicity. Molecular modelling of RidA(HOCl) and the rational design of a RidA variant that shows chaperone activity even in the absence of HOCl further supports our hypothesis. Our data provide a molecular mechanism for HOCl-mediated chaperone activity found in RidA and a growing number of other HOCl-activated chaperones.","pmid":"35598378","doi":"10.1016/j.redox.2022.102332","url":"https://pubmed.ncbi.nlm.nih.gov/35598378/"},{"id":793,"title":"Effect of Stabilized Hypochlorous Acid on Re-epithelialization and Bacterial Bioburden in Acute Wounds: A Randomized Controlled Trial in Healthy Volunteers.","authors":"Burian, Ewa A; Sabah, Lubna; Kirketerp-Møller, Klaus; Gundersen, Glenn; Ågren, Magnus S","year":2022,"date":"2022 May 31","journal":"Acta dermato-venereologica","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"The aim of this randomized controlled trial was to evaluate the wound-healing effect and antimicrobial properties of a novel stabilized hypochlorous acid solution on acute wounds, using a suction blister wound model. One suction blister was raised and de-roofed on each forearm in 20 healthy volunteers. Stabilized hypochlorous acid/control (sterile 0.9% NaCl) solutions were assigned to either wound by randomization. Wounds were irrigated and treated on days 0, 2 and 4. Re-epithelialization was assessed blindly by digital planimetry, and bacterial growth was assessed as the number of colony-forming units cultured from surface swabs. Hypochlorous acid solution increased the degree of re-epithelialization on day 4 by 14% compared with the control solution (95% confidence interval (CI) 6.8-20%, p = 0.00051) and was not inferior (p < 0.0001) to the control solution on day 10 (0.3%, 95% CI -1.3-1.9%). Median bacterial counts were lower with stabilized hypochlorous acid compared with control and were further reduced after irrigation and treatment of both groups on day 4, but remained lower in the stabilized hypochlorous acid group compared with the control group. This study demonstrates immediate and durable antimicrobial action and a beneficial effect on acute wound healing after irrigation and treatment with a stabilized hypochlorous acid formulation.","pmid":"35578822","doi":"10.2340/actadv.v102.1624","url":"https://pubmed.ncbi.nlm.nih.gov/35578822/"},{"id":795,"title":"Miniaturized 3D printed electrochemical platform with optimized Fibrous carbon electrode for non-interfering hypochlorite sensing.","authors":"Mohan, Jaligam Murali; Amreen, Khairunnisa; Javed, Arshad; Dubey, Satish Kumar; Goel, Sanket","year":2022,"date":"2022 Sep","journal":"Chemosphere","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"3D printing technology based electrochemical device can provide ease of fabrication, cost effectiveness, rapid detection and lower limit of detection. Herein, a novel, customized, portable and inexpensive 3D printed electrochemical device, has been presented. Fibrous carbon Toray paper, deposited with gold nanoparticles through electrodeposition, used as a working electrode which Further device was tested with 1 mM sodium hypochlorite using cyclic voltammetry (CV) and square wave voltammetry (SWV) in 0.1 M PBS. Hypochlorite has a pivotal role in supporting the growing chemical and paper industries and finds diverse uses in several clinical applications. It is primarily used for disinfecting food, water and surfaces. The scan rate study was carried out from 20 mVs(-1) to 250 mVs(-1) using cyclic voltammetry technique. The diffusion coefficient obtained from scan rate effect was 1.39 × 10(-6) cm(2)s(-1). The concentration range was evaluated with SWV technique, in a linear range of 0.6 μM-40 μM, with a detection limit of 0.7 μM. The device was further analyzed to ensure non-interference from co-existing chemicals like sodium chloride, potassium nitrate, sodium carbonate, sodium nitrite. Real sample analysis was done with sea, artificial sea and tap water with impressive recovery values. In summary, the developed working electrode can be customized and modified based on testing analyte; thus, the proposed device can be used for various other biochemical analytes.","pmid":"35568213","doi":"10.1016/j.chemosphere.2022.134915","url":"https://pubmed.ncbi.nlm.nih.gov/35568213/"},{"id":805,"title":"Reaction Mechanisms of Histidine and Carnosine with Hypochlorous Acid Along with Chlorination Reactivity of N-Chlorinated Intermediates: A Computational Study.","authors":"Han, Yuzhou; Zhou, Yingying; Liu, Yong Dong; Zhong, Rugang","year":2022,"date":"2022 May 16","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HOCl) released from activated leukocytes not only plays a significant role in the human immune system but is also implicated in numerous diseases including atherosclerosis and some cancers due to its inappropriate production. Histidine (His) and carnosine (Car), as a respective mediator and protective agent of HOCl damage, have attracted considerable attention; however, their detailed reaction mechanisms are still unclear. In this study, using a His residue with two peptide bond groups (HisRes) as a model, the reaction mechanisms of HisRes and Car including N(ε)H and N(δ)H tautomers with HOCl along with the chlorination reactivity of N-chlorinated intermediates were investigated by quantum chemical methods. The obtained results indicate that in the imidazole side chain, the pyridine-like N is the most reactive site rather than the pyrrole-like N, and the kinetic order of all of the possible reaction sites in HisRes follows pyridine-like N > imidazole C(δ) ≫ imidazole C(ε) > pyrrole-like N, while that in Car is pyridine-like N ≫ imidazole C(δ) ≫ amide N. As for N-chlorinated intermediates at imidazole, although the unprotonated form has a low chlorination reactivity as expected, it can still chlorinate tyrosine. Especially, the protonated form exhibits similar ability to HOCl, causing secondary damage in vivo. N-Chlorinated Car features higher internal chlorine migration ability than its intermolecular transchlorination, preventing further HOCl-induced damage. Additionally, a generally overlooked nucleophilic Cl(-) shift is also found in N-chlorinated Car/HisRes, indicating that nucleophilic sites in biomolecules also need to be considered. The outcomes of this study are expected to expand our understanding of secondary damage and protective mechanisms involved in HOCl in humans.","pmid":"35436107","doi":"10.1021/acs.chemrestox.1c00389","url":"https://pubmed.ncbi.nlm.nih.gov/35436107/"},{"id":807,"title":"Characterisation of chemical damage on tissue structures by multispectral imaging and machine learning procedures: Alkaline hypochlorite effect in C. elegans.","authors":"Verdú, Samuel; Fuentes, Cristina; Barat, José M; Grau, Raúl","year":2022,"date":"2022 Jun","journal":"Computers in biology and medicine","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Multispectral imaging represents a powerful technique to maximise data collection and analysis for biological materials. It improves the exploitation and understanding of in vivo/vitro experiments. This work focused on testing the capability of multispectral imaging to characterise the tissue damage produced by alkaline hypochlorite on the body and eggs of the biological model C. elegans. To that end, three synchronisation processes with different final bleach and sodium hydroxide concentrations were performed. The impact of treatments was characterised by measuring egg viability and morphology, besides capturing multispectral images of both nematode bodies and eggs. Multispectral images consisted of seven slices captured from different wavelengths within the visible/infrared spectrum by different light-pass filters. The results showed dependence between increased alkaline hypochlorite concentration and loss of egg viability/morphology. This relation was also observed for the imaging data, which showed alterations to tissue transmittance for all the tested wavelengths for both bodies and eggs. Localised alterations related to alkaline hypochlorite diffusion through anatomical nematode orifices were recognised. Applying multivariate methods to imaging data successfully characterised tissue alterations, from which treatment type was predicted for both nematodes and eggs. Moreover, the alterations recorded by imaging data were also used to predict egg viability regardless of treatment type (0.94). The high correlation between the imaging data from nematodes and eggs with egg viability evidenced multispectral imaging's ability to characterise tissue damage and its possible practical application to study alterations to the tissues of this biological model.","pmid":"35427984","doi":"10.1016/j.compbiomed.2022.105477","url":"https://pubmed.ncbi.nlm.nih.gov/35427984/"},{"id":810,"title":"Comparison of hypochlorous acid and Povidone Iodine as a disinfectant in neonatal circumcision.","authors":"Gözüküçük, Ali; Çakıroğlu, Basri","year":2022,"date":"2022 Jun","journal":"Journal of pediatric urology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"INTRODUCTION: Neonatal circumcision is a procedure used worldwide which has very low rates of complication if conducted by a specialist. The present research aims to examine the wound healing effects of Hypochlorous Acid (HCOL) and Povidone Iodine (PI) used as a disinfectant prior to the procedure of circumcision and their antibacterial effectiveness. MATERIAL AND METHOD: The findings of sixty infants subjected to neonatal circumcision at the Hisar Intercontinental Hospital between January 2021 and June 2021 were prospectively recorded. Based on the disinfectant used, the patients were divided into two group: Group 1 including 28 patients for whom HCOL was used as an antiseptic solution, and Group 2 including 32 patients to whom PI was administered. RESULTS: Group 1 was formed of 28 patients while Group 2 included 32 patients. The mean ages of each group was 15.46 ± 10.58 (2-29) and 12.63 ± 10.00 (2-28) days, respectively. When the complications were examined individually, no significant difference was found between the groups. However, when all complications were analyzed collectively, it was determined that there was a significant difference, and the complication rate of Group 2 was greater (p = 0.037). In Group 2, the rate of edema and wound healing delay was significantly greater than that of Group 1 (p: 0.037 p: 0.036) (Table 1). CONCLUSION: It was determined that HCOL is reliable to be used as a disinfectant prior to neonatal circumcision.","pmid":"35414414","doi":"10.1016/j.jpurol.2022.03.011","url":"https://pubmed.ncbi.nlm.nih.gov/35414414/"},{"id":812,"title":"Inactivation of SARS-CoV-2 and influenza A virus by dry fogging hypochlorous acid solution and hydrogen peroxide solution.","authors":"Urushidani, Masahiro; Kawayoshi, Akira; Kotaki, Tomohiro; Saeki, Keiichi; Mori, Yasuko; Kameoka, Masanori","year":2022,"date":"2022","journal":"PloS one","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is transmitted mainly by droplet or aerosol infection; however, it may also be transmitted by contact infection. SARS-CoV-2 that adheres to environmental surfaces remains infectious for several days. We herein attempted to inactivate SARS-CoV-2 and influenza A virus adhering to an environmental surface by dry fogging hypochlorous acid solution and hydrogen peroxide solution. SARS-CoV-2 and influenza virus were air-dried on plastic plates and placed into a test chamber for inactivation by the dry fogging of these disinfectants. The results obtained showed that the dry fogging of hypochlorous acid solution and hydrogen peroxide solution inactivated SARS-CoV-2 and influenza A virus in CT value (the product of the disinfectant concentration and contact time)-dependent manners. SARS-CoV-2 was more resistant to the virucidal effects of aerosolized hypochlorous acid solution and hydrogen peroxide solution than influenza A virus; therefore, higher concentrations of disinfectants or longer contact times were required to inactivate SARS-CoV-2 than influenza A virus. The present results provide important information for the development of a strategy that inactivates SARS-CoV-2 and influenza A virus on environmental surfaces by spatial fogging.","pmid":"35389997","doi":"10.1371/journal.pone.0261802","url":"https://pubmed.ncbi.nlm.nih.gov/35389997/"},{"id":817,"title":"Efficacy of hypochlorous acid (HOCl) fog in sanitizing surfaces against Enterococcus faecalis.","authors":"Feng, Kuan-Che; Ghai, Anish; Liu, Haijiao; Salerno, Andrew; Miller, Curtis; Liu, Jessica; Manesh, Sana; Cymerman, Jerome; Simon, Marcia; Walker, Stephen G; Rafailovich, Miriam","year":2022,"date":"2022 Dec","journal":"American journal of infection control","category":"Materials & industrial applications","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Fogging is an efficient method when disinfection of large areas is desired. METHODS: Two methods of ultrasonic fogging, pulsed and continuous, were compared on bacteria dried on either aluminum or polystyrene surfaces. We characterized commercial and home-made hypochlorous acid (HOCl) with respect to storage and means of production. RESULTS: We found that the initial chlorine concentration of the commercial solution was approximately 550 ppm, and when stored open under ambient conditions, the chlorine content decreased at a rate of 30% every 100 days. The HOCl produced using the home synthesizers had a maximum chlorine content of 257.6 ppm which decayed by 65% after 100 days. A second synthesizer produced a liquid with high chlorine content and pH, 750ppm and pH = 8.55. The anti-bacterial efficacy was probed using Enterococcus faecalis, a persistent source of infection in public and clinical spaces. Time course studies determined that E. faecalis could survive dry on surfaces for more than 12 weeks, but was easily eliminated in half the fogging time. CONCLUSIONS: The most effective mode of application was determined to be continuous fogging where a 6.59 log reduction was established in vertical geometry. The optimal pulsed fogging protocol produced a similar reduction, but required nearly 5 times as long. The home synthesized versions yielded much lower log bacterial reductions. No significant differences in outcome were determined between polymer or metal surfaces.","pmid":"35307474","doi":"10.1016/j.ajic.2022.03.009","url":"https://pubmed.ncbi.nlm.nih.gov/35307474/"},{"id":818,"title":"Neutrophil-Derived Myeloperoxidase and Hypochlorous Acid Critically Contribute to 20-Hydroxyeicosatetraenoic Acid Increases that Drive Postischemic Angiogenesis.","authors":"Azcona, Juan A; Tang, Samantha; Berry, Elizabeth; Zhang, Frank F; Garvey, Radha; Falck, John R; Schwartzman, Michal Laniado; Yi, Tao; Jeitner, Thomas M; Guo, Austin M","year":2022,"date":"2022 Jun","journal":"The Journal of pharmacology and experimental therapeutics","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Compensatory angiogenesis is an important adaptation for recovery from critical ischemia. We recently identified 20-hydroxyeicosatetraenoic acid (20-HETE) as a novel contributor of ischemia-induced angiogenesis. However, the precise mechanisms by which ischemia promotes 20-HETE increases that drive angiogenesis are unknown. This study aims to address the hypothesis that inflammatory neutrophil-derived myeloperoxidase (MPO) and hypochlorous acid (HOCl) critically contribute to 20-HETE increases leading to ischemic angiogenesis. Using Liquid Chromatography-Mass Spectrometry/Mass Spectrometry, Laser Doppler Perfusion Imaging, and Microvascular Density analysis, we found that neutrophil depletion and MPO knockout mitigate angiogenesis and 20-HETE production in the gracilis muscles of mice subjected to hindlimb ischemia. Furthermore, we found MPO and HOCl to be elevated in these tissues postischemia as assessed by immunofluorescence microscopy and in vivo live imaging of HOCl. Next, we demonstrated that the additions of either HOCl or an enzymatic system for generating HOCl to endothelial cells increase the expression of CYP4A11 and its product, 20-HETE. Finally, pharmacological interference of hypoxia inducible factor (HIF) signaling results in ablation of HOCl-induced CYP4A11 transcript and significant reductions in CYP4A11 protein. Collectively, we conclude that neutrophil-derived MPO and its product HOCl activate HIF-1α and CYP4A11 leading to increased 20-HETE production that drives postischemic compensatory angiogenesis. SIGNIFICANCE STATEMENT: Traditionally, neutrophil derived MPO and HOCl are exclusively associated in the innate immunity as potent bactericidal/virucidal factors. The present study establishes a novel paradigm by proposing a unique function for MPO/HOCl as signaling agents that drive critical physiological angiogenesis by activating the CYP4A11-20-HETE signaling axis via a HIF-1α-dependent mechanism. The findings from this study potentially identify novel therapeutic targets for the treatment of ischemia and other diseases associated with abnormal angiogenesis.","pmid":"35306474","doi":"10.1124/jpet.121.001036","url":"https://pubmed.ncbi.nlm.nih.gov/35306474/"},{"id":822,"title":"An efficient PeT based fluorescent probe for mapping mitochondrial oxidative stress produced via the Nox2 pathway.","authors":"Baruah, Mousumi; Jana, Anal; Ali, Mudassar; Mapa, Koyeli; Samanta, Animesh","year":2022,"date":"2022 Mar 30","journal":"Journal of materials chemistry. B","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The human innate immune system eliminates invading pathogens through phagocytosis. The first step of this process is activating the nicotinamide adenine dinucleotide phosphate oxidase (Nox2) that utilizes NADPH to produce superoxide anion radicals and other reactive oxygen species (ROS). These ROS then alter the mitochondrial membrane potential and increase peroxide in the mitochondria. The peroxide reacts with myeloperoxidase (MPO) and chloride ions to produce pro-inflammatory oxidant hypochlorous acid (HOCl), which causes oxidative stress leading to cell death. The adverse effects of HOCl are highly associated with cardiovascular disease, neurodegenerative disorders, acute lung injuries, inflammatory diseases, and cancer. Therefore, mapping HOCl in the Nox2 pathway is crucial for an in-depth understanding of the innate immune system. Herein, we developed a unique pentacyclic pyridinium probe, PM-S, that exhibited efficient photoinduced electron transfer (PeT) with HOCl triggered methyl(phenyl)sulfane. PM-S showed several advantages, including better chemical stability, large Stokes shifts (>6258 cm(-1)), high sensitivity (∼50 nM) and specificity to mitochondria, compared to its parent pyrylium PY-S derivative. This probe is also efficient in studying the HOCl produced via the Nox2 pathway in HepG2 and HeLa cells. Analysis using a simple microplate reader and FACS analysis with various inhibitors and inducers supported the mechanistic understanding of Nox2, which can offer an advanced platform for monitoring the inflammatory process more efficiently.","pmid":"35289831","doi":"10.1039/d2tb00356b","url":"https://pubmed.ncbi.nlm.nih.gov/35289831/"},{"id":824,"title":"Hypochlorous acid as a disinfectant for high-risk HPV: Insight into the mechanism of action.","authors":"Robins, Lori I; Clark, Andrew; Gafken, Philip R; Alam, Samina; Milici, Janice; Hassan, Reem; Wang, Che-Yen; Williams, Jeffrey; Meyers, Craig","year":2022,"date":"2022 Jul","journal":"Journal of medical virology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Medical instruments that are not autoclavable but may become contaminated with high-risk human papillomaviruses (HPVs) during use must be thoroughly disinfected to avoid the possibility of iatrogenic transmission of infection. There is an expectation that prolonged soaking of instruments in the United States Food and Drug Administration-cleared chemical disinfectant solutions will result in high-level decontamination, but HPV16 and HPV18 are known to be resistant to commonly used formulations. However, they are susceptible to a variety of oxidative agents, including those based on chlorine. Here, we tested the efficacy of homogeneous hypochlorous acid (HOCl) solutions against mature infectious virions of HPV16 and HPV18 dried onto butadiene styrene coupons and ultrasonic probes. Both viruses were inactivated to >4 log reduction value (LRV) after 15 s on coupons and 5 min on ultrasonic probes. Morphologic changes became evident within those contact times by transmission electron microscopy when HPV16 virus-like particles were exposed to HOCl under identical conditions. Mass spectrometry analysis of trypsin-digested products of L1 capsid proteins exposed to HOCl showed that mostly conserved residues were modified by oxidation and that these changes rapidly lead to instability of the protein demonstrable on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Modifications to these residues may contribute to rapid virus inactivation. The use of homogeneous HOCl solutions for HPV decontamination provides a highly effective means of assuring the safety of nonautoclavable medical instruments.","pmid":"35277984","doi":"10.1002/jmv.27716","url":"https://pubmed.ncbi.nlm.nih.gov/35277984/"},{"id":825,"title":"The Microbiome of Meibomian Gland Secretions from Patients with Internal Hordeolum Treated with Hypochlorous Acid Eyelid Wipes.","authors":"Yang, Shu; Wu, Bing-Cheng; Cheng, Zhe; Li, Lan; Zhang, Yuan-Ping; Zhao, Hui; Zeng, Han-Mei; Qi, Dong-Fang; Ma, Zi-Yao; Li, Jian-Guo; Han, Rui; Qu, Fang-Zhou; Luo, Yan; Liu, Yi; Chen, Xiao-Lei; Dai, Hong-Mei","year":2022,"date":"2022","journal":"Disease markers","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"OBJECTIVE: The aims of our experiment were to compare the microorganisms in meibomian gland secretions from patients with internal hordeolum before and after treatment using hypochlorous acid eyelid wipes, to elucidate the mechanism underlying hypochlorous acid eyelid wipe treatment of internal hordeolum. METHODS: This was a prospective, matched-pair study. A total of eight patients with internal hordeolum who attended the ophthalmology clinic of our hospital from April to August 2020 were included. Meibomian gland secretions were collected from subjects before treatment (Group A) and from patients cured after eyelid cleaning with hypochlorous acid eyelid wipes for 7 days (Group B). Samples were submitted to 16S rRNA high-throughput sequencing, and the resulting data were analyzed to compare the differences in the structure and composition of meibomian gland secretion microbial flora before and after treatment of internal hordeolum. RESULTS: A total of 2127 operational taxonomic units were obtained from the two groups of samples, and there was no significant difference in alpha diversity before and after eyelid cleaning. At the phylum level, there was no significant difference between the two groups. The predominant phyla in Group A included the following: Firmicutes (32.78% ± 20.16%), Proteobacteria (26.73% ± 7.49%), Acidobacteria (10.58% ± 11.45%), Bacteroidetes (9.05% ± 6.63%), Actinobacteria (8.48% ±1.77%), and Chloroflexi (3.15% ± 3.12%), while those in Group B were the following: Proteobacteria (31.86% ± 9.69%), Firmicutes (29.07% ± 24.20%), Acidobacteria (11.33% ± 7.53%), Actinobacteria (7.10% ± 1.98%), Bacteroidetes (5.39% ± 5.17%), and Chloroflexi (3.89% ± 3.67%). Starting from the class level, significant differences in microbial communities were detected before and after eyelid cleaning (P < 0.05). Linear discriminant analysis effect size analysis showed the core flora in Group A microbiome comprising Actinobacteria, Staphylococcus, Staphylococcaceae, Staphylococcus aureus, Ruminococcacea UCg-014, Ruminococcacea-UCG-014, Halomonadaceae, Neisseria, Methylobacterium, Frankiales, and Neisseria sicca, while those in Group B microbial were Streptococcus sp., Blautia, Bifidobacterium pseudocatenulatum, Subdoligranulum, Subdoligranulum variabile, Faecalibacterium, and Faecalibacterium prausnitzii. CONCLUSION: Eyelid cleaning with hypochlorous acid eyelid wipes does not change the biodiversity in the meibomian gland secretions of patients with internal hordeolum. Hypochlorous acid eyelid wipes may affect the internal hordeolum through broad-spectrum antibacterial action to effectively reduce the relative abundance of symbiotic pathogens, such as Staphylococcus, Neisseria, Actinomycetes, and Ruminococcus and increase that of Faecalibacterium prausnitzii and other symbiotic probiotics with anti-inflammatory effects.","pmid":"35251376","doi":"10.1155/2022/7550090","url":"https://pubmed.ncbi.nlm.nih.gov/35251376/"},{"id":827,"title":"Engineering of Portable Smartphone Integrated with Liposome-Encapsulated Curcumin for Onsite Visual Ratiometric Fluorescence Imaging of Hypochlorite.","authors":"Shen, Yizhong; Zhu, Chunlei; Wei, Yunlong; Chen, Huanhuan; Wu, Zeyu; Ye, Yingwang; Han, De-Man","year":2022,"date":"2022 Apr 19","journal":"Chemistry (Weinheim an der Bergstrasse, Germany)","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Precisely onsite monitoring of hypochlorite (ClO(-) ) is of great significance to guide its rational use, reducing/avoiding its potential threat toward food safety and human health. Considering ClO(-) could quench fluorescence of curcumin (CCM) by oxidizing the o-methoxyphenol of CCM into benzoquinone, a portable ratiometric fluorescence sensor integrated with smartphone was designed for realizing the visual point-of-care testing (POCT) of ClO(-) . The amphiphilic phospholipid polymer was used as carrier to wrap curcumin, forming a novel liposome-encapsulated CCM, which provided a scaffold to bind with [Ru(bpy)(3) ](2+) through electrostatic interaction, thus assembling [Ru(bpy)(3) ](2+) -functionalized liposome-encapsulated CCM ([Ru(bpy)(3) ](2+) @CCM-NPs). Further integrated with smartphone, visual imaging of [Ru(bpy)(3) ](2+) @CCM-NPs could be achieved and the accurate onsite detection of ClO(-) could be realized with a detection limit of 66.31 nM and a linear range of 0.2210 to 80.0 μM. In addition, the sensor could monitor ClO(-) in real samples with an onsite detection time of ∼154.0 s.","pmid":"35233854","doi":"10.1002/chem.202200263","url":"https://pubmed.ncbi.nlm.nih.gov/35233854/"},{"id":831,"title":"Hydrogen Peroxide and Hypochlorite Responsive Fluorescent Nanoprobes for Sensitive Cancer Cell Imaging.","authors":"Chen, Yun; Ye, Jing; Lv, Gang; Liu, Weiwei; Jiang, Hui; Liu, Xiaohui; Wang, Xuemei","year":2022,"date":"2022 Feb 11","journal":"Biosensors","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Accurate diagnosis of cancer cells directly affects the clinical treatment of cancer and can significantly improve the therapeutic effect of cancer patients. Cancer cells have a unique microenvironment with a large amount of peroxide inside, effectively differentiated from relevant microenvironment normal cells. Therefore, designing the high-sensitive probes to recognize and distinguish the special physiological microenvironment of cancer cells can shed light on the early diagnosis of cancers. In this article, we design and construct a fluorescence (FL) contrast agent for cancer cell recognition and imaging analysis. Firstly, luminol-gold NPs (Lum-AuNPs) have been initially built, and then successfully loaded with the fluorescent receptor Chlorin e6 (Ce6) to prepare the luminescent nanoprobes (Ce6@Lum-AuNPs) with green synthesis, i.e., with biocompatible agents and mild temperature. The as-prepared fluorescent Ce6@Lum-AuNPs can efficiently and sensitively realize FL bioimaging of cancer cells. The relevant bio-sensing mechanism pertains to the presence of hypochlorite (ClO(-)); hydrogen peroxide (H(2)O(2)) in cancer cells could readily interact with luminol to produce chemiluminescence, which can activate the Ce6 component to emit near-infrared (NIR) FL. Therefore, this raises the possibility of utilizing the Ce6@Lum-AuNPs as efficient fluorescent nanoprobes for promising cancer early diagnosis and other relevant disease bioanalysis.","pmid":"35200371","doi":"10.3390/bios12020111","url":"https://pubmed.ncbi.nlm.nih.gov/35200371/"},{"id":832,"title":"Strategy for reducing cytotoxicity and obtaining esthetic efficacy with 15 min of in-office dental bleaching.","authors":"Ortecho-Zuta, Uxua; de Oliveira Duque, Carla Caroline; de Oliveira Ribeiro, Rafael Antonio; Leite, Maria Luísa; Soares, Diana Gabriela; Hebling, Josimeri; Briso, André Luiz Fraga; de Souza Costa, Carlos Alberto","year":2022,"date":"2022 May","journal":"Clinical oral investigations","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVES: Evaluate in vitro the esthetic efficacy and cytotoxicity of a bleaching gel containing 35% hydrogen peroxide (BG-35%H(2)O(2)), applied for different time intervals, on enamel coated or not with polymeric biomaterials. MATERIALS AND METHODS: Nanofiber scaffolds (NSc) and a primer catalyst (PrCa) were used to coat the bovine enamel/dentin discs before the application of BG-35%H(2)O(2), according to the following groups: G1-negative control (NC, without treatment); G2, G3, and G4-BG-35%H(2)O(2) applied for 3 × 15, 2 × 15, and 15 min; G5, G6, and G7-BG-35%H(2)O(2) applied on enamel coated with NSc and PrCa for 3 × 15; 2 × 15, and 15 min, respectively. The culture medium with components of gel diffused through the discs was applied on MDPC-23 cells, which were evaluated regarding to viability (VB), integrity of the membrane (IM), and oxidative stress (OxS). The quantity of H(2)O(2) diffused and esthetic efficacy (ΔE/ΔWI) of the dental tissues were also analyzed (ANOVA/Tukey; p < 0.05). RESULTS: Only G7 was similar to G1 regarding VB (p > 0.05). The lowest value of H(2)O(2) diffusion occurred in G4 and G7, where the cells exhibited the lowest OxS than G2 (p < 0.05). Despite G5 showing the greatest ΔE regarding other groups (p < 0.05), the esthetic efficacy observed in G7 was similar to G2 (p > 0.05). ΔWI indicated a greater bleaching effect for groups G5, G6, and G7 (p < 0.05). CONCLUSION: Coating the dental enamel with polymeric biomaterials reduced the time and the cytotoxicity of BG-35%H(2)O(2). CLINICAL SIGNIFICANCE: Coating the dental enamel with polymeric biomaterials allows safer and faster BG-35%H(2)O(2) application.","pmid":"35199193","doi":"10.1007/s00784-022-04379-z","url":"https://pubmed.ncbi.nlm.nih.gov/35199193/"},{"id":835,"title":"Resistance of Streptococcus pneumoniae to Hypothiocyanous Acid Generated by Host Peroxidases.","authors":"Shearer, Heather L; Kaldor, Christopher D; Hua, Harry; Kettle, Anthony J; Parker, Heather A; Hampton, Mark B","year":2022,"date":"2022 Mar 17","journal":"Infection and immunity","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Streptococcus pneumoniae is a serious human respiratory pathogen. It generates hydrogen peroxide (H(2)O(2)) as part of its normal metabolism, yet it lacks enzymes that remove this oxidant. Here we show that lactoperoxidase and myeloperoxidase, two host enzymes present in the respiratory tract, convert bacterial H(2)O(2) into HOSCN that S. pneumoniae can resist. We found that incubation of S. pneumoniae with myeloperoxidase in chloride-rich buffer killed the bacteria due to formation of toxic hypochlorous acid (HOCl). However, the addition of physiological concentrations of thiocyanate protected the bacteria. Similarly, S. pneumoniae remained viable in the presence of lactoperoxidase and thiocyanate even though the majority of bacterial H(2)O(2) was converted to hypothiocyanous acid (HOSCN). S. pneumoniae and Pseudomonas aeruginosa, another respiratory pathogen, were similarly sensitive to H(2)O(2) and HOCl. In contrast, S. pneumoniae tolerated much higher doses of HOSCN than P. aeruginosa. When associated with neutrophil extracellular traps (NETs), S. pneumoniae continued to generate H(2)O(2), which was converted to HOCl by myeloperoxidase (MPO) present on NETs. However, there was no loss in bacterial viability because HOCl was scavenged by the NET proteins. We conclude that at sites of infection, bacteria will be protected from HOCl by thiocyanate and extracellular proteins including those associated with NETs. Resistance to HOSCN may give S. pneumoniae a survival advantage over other pathogenic bacteria. Understanding the mechanisms by which S. pneumoniae protects itself from HOSCN may reveal novel strategies for limiting the colonization and pathogenicity of this deadly pathogen.","pmid":"35156851","doi":"10.1128/IAI.00530-21","url":"https://pubmed.ncbi.nlm.nih.gov/35156851/"},{"id":836,"title":"Hypochlorous acid as an antiseptic in the care of patients with suspected COVID-19 infection.","authors":"Gessa Sorroche, M; Relimpio López, I; García-Delpech, S; Benítez Del Castillo, J M","year":2022,"date":"2022 Feb","journal":"Archivos de la Sociedad Espanola de Oftalmologia","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"PURPOSE: The SARS-CoV-2 virus, which causes COVID-19 disease, is transmitted by aerosols or by contact with infected surfaces. The route of entry to the body is through the nasal, oral or conjunctival mucosa. Health workers must use effective protection measures against the entry of the virus into mucous membranes, both physical and antiseptic filters. There is an antiseptic used in Ophthalmology that we believe could have virucidal action against the SARS-CoV-2 virus, formulated based on 0.01% hypochlorous acid. METHODS: An exhaustive search has been carried out in the databases of Pubmed and Web of Science to identify relevant articles on the virucidal activity of hypochlorous acid in different concentrations until October 4, 2020. RESULTS: There is evidence of the virucidal efficacy of 0.01% hypochlorous acid against SARS-CoV-2. According to the different scientific publications reviewed, hypochlorous acid has virucidal efficacy against different viruses, among them, SARS-CoV-2. CONCLUSIONS: The 0.01% hypochlorous acid could act as an effective antiseptic against SARS-CoV-2, exerting a barrier on the mucosa to prevent COVID-19 infection. It can be used on the eyes, nose and mouth. We consider it necessary to assess its use in the protocol for patient health care in ophthalmology consultations, as well as to recommend its use to the general population to reduce viral load and/or prevent transmission of infection. Additional in vivo studies would be required to confirm its antiseptic action.","pmid":"35152952","doi":"10.1016/j.oftale.2021.01.010","url":"https://pubmed.ncbi.nlm.nih.gov/35152952/"},{"id":843,"title":"Rapid in vitro virucidal activity of slightly acidic hypochlorous acid water toward aerosolized coronavirus in simulated human-dispersed droplets.","authors":"Miyaoka, Yu; Yamaguchi, Makiko; Kadota, Chisaki; Hasan, Md Amirul; Kabir, Md Humayun; Shoham, Dany; Murakami, Harumi; Takehara, Kazuaki","year":2022,"date":"2022 Apr 2","journal":"Virus research","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The virucidal activities were evaluated by spraying slightly acidic hypochlorous acid waters (SAHWs) containing various concentrations of free available chlorine - 100, 200, 300 and 500 ppm (SAHW-100, -200, -300 and -500, respectively) - toward aerosol of an avian coronavirus (infectious bronchitis virus: IBV). The viral solution was supplemented with 0.5% fetal bovine serum (FBS) to simulate normal human droplets generated by sneezing or coughing in a real-life scenario. The virus containing 0.5% FBS was sprayed and exposed to SAHWs for a few seconds in a closed chamber, before reaching the air sampler. The results showed that IBV exposed to SAHW-100 and -200 for a few seconds decreased by 0.21 log(10) and 0.80 log(10), respectively, compared to the pre-exposed samples to SAHWs as controls. On the other hand, reductions of 1.16 log(10) and 1.67 log(10) were achieved following the exposure to SAHW-300 and -500, respectively, within a few seconds. These results suggest that SAHWs have rapid in vitro virucidal activity toward aerosolized IBV. The findings obtained for IBV might basically be applicable in relation to SARS-CoV-2, given the resemblance between the two viruses. To prevent human-to-human transmissions by aerosols, the inactivation of viruses in the air by exposure to SAHWs for a few seconds seems to be an effective way.","pmid":"35093473","doi":"10.1016/j.virusres.2022.198701","url":"https://pubmed.ncbi.nlm.nih.gov/35093473/"},{"id":847,"title":"Effects of tooth bleaching protocols with violet LED and hydrogen peroxide on enamel properties.","authors":"Costa, Joatan Lucas de Sousa Gomes; Besegato, João Felipe; Zaniboni, Joissi Ferrari; Galvani, Lucas David; Kuga, Milton Carlos","year":2022,"date":"2022 Jun","journal":"Photodiagnosis and photodynamic therapy","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"BACKGROUND: This study evaluated the color change, enamel surface roughness and microhardness after different tooth bleaching protocols, using hydrogen peroxide (HP) and/or violet LED. METHODS: Forty bovine specimens (7 × 7 × 2 mm) were randomly distributed into 4 groups: 35% HP, 6% HP, 6% HP + violet LED and violet LED alone. First, the specimens were stained with black tea and then submitted to two bleaching sessions of 30 min with an interval of 7 days. Color change (∆L*, ∆a*, ∆b* and ∆E(00)) after 24 h of each session and 1 week after the last session was evaluated. Enamel roughness and microhardness were evaluated immediately before the sessions, 24 h and 1 week after the last session. Data were evaluated by ANOVA for repeated measures and Bonferroni post-test or Kruskall-Wallis and Dunn tests (α = 0.05). Representative specimens from each group were analyzed by scanning electron microscopy. RESULTS: 6% HP + violet LED and 35% HP showed the highest color change, while violet LED alone had the lowest results. Enamel roughness analyses showed that 6% HP + violet LED and 35% HP showed changes after two bleaching sessions. No differences were observed regarding enamel microhardness. CONCLUSIONS: The use of 6% HP + violet LED showed enhanced bleaching efficacy compared to 35% HP. However, violet LED used alone exhibited the lowest color change. 6% HP + violet LED and 35% HP promoted changes on enamel roughness, while no microhardness changes was observed for any group.","pmid":"35065278","doi":"10.1016/j.pdpdt.2022.102733","url":"https://pubmed.ncbi.nlm.nih.gov/35065278/"},{"id":856,"title":"A ratiometric fluorescent probe for sensing hypochlorite in physiological saline, bovine serum albumin and fetal bovine/calf serum.","authors":"Fang, Shirong; Wang, Lihong; Mei, Yongtian; Zheng, Kaibo","year":2022,"date":"2022 Mar 15","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"HClO/ClO(-), as one of important reactive oxygen species, is a highly reactive unavoidable by-product generated from normal cell metabolism. In recent years, efficient method for detectiing HClO/ClO(-) is of great important to research its pathological or physiological function in bio-systems. In this work, we have constructed a fluorescent probe (P-Hc) with ratiometric signal for sensing HClO/ClO(-) in aqueous solution, physiological saline and different serums based on 2-(benzo[d]thiazol-2-yl)phenol dye. The structure of P-Hc was characterized by NMR and HRMS spectrum. The sensing mechanism has also been verified by (1)H NMR spectrum. The P-Hc displays good sensitivity and selectivity for HClO/ClO(-) with a limit of detection (LOD) of 2.03 × 10(-6) M. Furthermore, P-Hc has been applied for sensing HClO/ClO(-) in physiological saline and different serums. Thus, P-Hc may provide a novel method for ratiometric fluorescent sensing HClO/ClO(-) in bio-samples.","pmid":"34954481","doi":"10.1016/j.saa.2021.120738","url":"https://pubmed.ncbi.nlm.nih.gov/34954481/"},{"id":861,"title":"Effect of ionizing radiation on human myeloperoxidase: Reaction with hydrated electrons.","authors":"Ramos, Daniel R; Fernández, M Isabel; Furtmüller, Paul G; Obinger, Christian; García, M Victoria; Santaballa, J Arturo; Canle, Moisés","year":2022,"date":"2022 Jan","journal":"Journal of photochemistry and photobiology. B, Biology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase (MPO) is a myeloid-lineage restricted enzyme largely expressed in the azurophilic granules of neutrophils. It catalyses the formation of reactive oxygen species, mainly hypochlorous acid, contributing to anti-pathogenic defense. Disorders in the production or regulation of MPO may lead to a variety of health conditions, mainly of inflammatory origin, including autoimmune inflammation. We have studied the effect of ionizing radiation on the activity of MPO, as measured by the capacity retained by the enzyme to produce hypochlorous acid as reactive oxygen species after exposure to successive doses of solvated electrons, the strongest possible one-e(-) reducing agent in water. Chlorination activity was still present after a very high irradiation dose, indicating that radiation damage does not take place at the active site, hindered in the core of MPO structure. Decay kinetics show a dependence on the wavelength, supporting that the process must occur at peripheral functional groups situated on external and readily accessible locations of the enzyme. These results are relevant to understand the mechanism of resistance of our innate anti-pathogenic defense system and also to get insight into potential strategies to regulate MPO levels as a therapeutic target in autoimmune diseases.","pmid":"34864529","doi":"10.1016/j.jphotobiol.2021.112369","url":"https://pubmed.ncbi.nlm.nih.gov/34864529/"},{"id":868,"title":"Luminescence Nanoprobe in the Near-Infrared-II Window for Ultrasensitive Detection of Hypochlorite.","authors":"Fu, Xiao; Wu, Jinmei; Xu, Huajian; Wan, Pingping; Fu, Huimin; Mei, Qingsong","year":2021,"date":"2021 Nov 30","journal":"Analytical chemistry","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Sensitive and selective detection of hypochlorite is in great demand for food safety, especially in fresh cold chain products. However, the detection limit of traditional visible emission-based strategies cannot satisfy the requirement of ultrasensitive analysis in practical applications. In this work, we explored a novel luminescent nanoprobe in the near-infrared-II (NIR-II) window to greatly improve the hypochlorite detection limit for analysis of real milk samples, which was based on the fluorescence resonance energy-transfer process between the hypochlorite-responsive dye (FD1080) and the lanthanide-doped downconverted nanoparticles. Specifically, the NIR-II luminescence from Yb ions was first suppressed by FD1080 due to the energy-transfer mechanism. In the presence of hypochlorite, FD1080 was bleached to recover the luminescence. As a proof-of-concept, the optimal nanoprobe exhibited a linear luminescence recovery in the range of 0.1-1 nM with the detection limit of 0.0295 nM for hypochlorite. Real milk sample detection experiments showed that the probe had good accuracy and precision.","pmid":"34784176","doi":"10.1021/acs.analchem.1c03582","url":"https://pubmed.ncbi.nlm.nih.gov/34784176/"},{"id":872,"title":"Hypochlorous Acid-Generating Electrochemical Catheter Prototype for Prevention of Intraluminal Infection.","authors":"Cano, Edison J; Flurin, Laure; Mohamed, Abdelrhman; Greenwood-Quaintance, Kerryl E; Raval, Yash S; Beyenal, Haluk; Patel, Robin","year":2021,"date":"2021 Oct 31","journal":"Microbiology spectrum","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Central line-associated bloodstream infection (CLABSI) contributes to mortality and cost. While aseptic dressings and antibiotic-impregnated catheters prevent some extraluminal infections, intraluminal infections remain a source of CLABSIs. In this proof-of-concept study, an electrochemical intravascular catheter (e-catheter) prototype capable of electrochemically generating hypochlorous acid intraluminally using platinum electrodes polarized at a constant potential of 1.5 electrode potential relative to saturated silver/silver chloride reference electrode measured in volts (V(Ag/AgCl)) was developed. After 24 h of prepolarization at 1.5 V(Ag/AgCl), their activity was tested against clinical isolates of Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecium, and Escherichia coli derived from catheter-related infections. e-catheters generated a mean HOCl concentration of 15.86 ± 4.03 μM and had a mean pH of 6.14 ± 0.79. E-catheters prevented infections of all four species, with an average reduction of 8.41 ± 0.61 log(10) CFU/ml at 48 h compared to controls. Polarized e-catheters which generate low amounts of HOCl continuously should be further developed to prevent intraluminal infection. IMPORTANCE Catheter-related infections constitute an economic and mortality burden in health care. Several options are available to reduce the risk of infection, but only a few focus on preventing intraluminal infection, which occurs in long-term catheters, most often used for dialysis, prolonged treatment, or chemotherapy. A prototype of a catheter called an \"e-catheter\" composed of three electrodes, capable of producing hypochlorous acid (HOCl) electrochemically in its lumen, was developed. When polarized at 1.5 V, chloride ions in the solution are oxidized to continuously produce low amounts of HOCl, which exhibits antibacterial activity in the lumen of the catheter. Here, this prototype was shown to be able to generate HOCl as well as prevent infection in a preliminary in vitro catheter model. This approach is a potential strategy for catheter infection prevention.","pmid":"34704827","doi":"10.1128/Spectrum.00557-21","url":"https://pubmed.ncbi.nlm.nih.gov/34704827/"},{"id":873,"title":"Can hypochlorous acid be a powerful sanitizer to replace alcohol for disinfection ? -Its bactericidal, degradation of the solutions under various storage condition, and steel rust effects.","authors":"Kameda, Takashi; Oka, Shunya; Igawa, Jun-Ichi; Sakamoto, Makoto; Terada, Kazuto","year":2022,"date":"2022 Feb 1","journal":"Dental materials journal","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Coronavirus disease pandemic has led to a shortage of disinfectant alcohol (DA; 76.9-81.4% ethanol solution) in Japan. This study investigated the availability of hypochlorous acid (HA) as an alternative disinfectant to DA in clinical environment. HA is a safe and economical disinfectant with a broad antibacterial spectrum and low risk of hand irritation, which is used worldwide. In this study, HA and sodium hypochlorite solution (SH) were degraded over time and the degradation was accelerated by temperature and lighting. Results of bactericidal effects of HA revealed that the realistic effective concentration should be 200 ppm. Compared with DA, the dental carbon steel burs were more severely rusted by SH and HA. These results indicated that high concentration of HA generated on-site could be an effective and safe disinfectant for use immediately after generation with consideration of object materials in clinical environment, as an alternative to DA.","pmid":"34690228","doi":"10.4012/dmj.2021-146","url":"https://pubmed.ncbi.nlm.nih.gov/34690228/"},{"id":875,"title":"The effectiveness of the information-motivation model and domestic brushing with a hypochlorite-based formula on peri-implant mucositis: A randomized clinical study.","authors":"Cosola, Saverio; Oldoini, Giacomo; Giammarinaro, Enrica; Covani, Ugo; Genovesi, Annamaria; Marconcini, Simone","year":2022,"date":"2022 Feb","journal":"Clinical and experimental dental research","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"OBJECTIVE: Management of mucositis is essential for the long-term maintenance of dental implants. This study determined the efficacy, in terms of clinical parameters, of an adjunctive domiciliary agent paired with non-surgical periodontal therapy (NSPT) for patients with peri-implant mucositis. MATERIALS AND METHODS: Patients involved in a periodontal maintenance program were randomly distributed to the domestic use of a chlorhexidine toothpaste and mouthwash (control) or a hypochlorite-based formula brushing solution (test) after diagnosis of peri-implant mucositis. A modified approach towards NSPTwas performed after 10 days of domestic use of the assigned maintenance product in both groups. Clinical and patient-related outcomes were recorded during a 90-day follow-up period. RESULTS: Forty patients completed the three-month study (20 patients per group). Both groups showed relevant clinical and patient outcome improvements after the NSPT (T2) and between T1 and T2 (p < 0 0.01), except for PPD. For the test group, the clinical improvement was significantly greater than that for the control group at the seventh-day evaluation (T(1) ) in the gingival index (0-3) and FMBS (%). Favorable outcomes were maintained during the entire follow-up period. CONCLUSION: The present study showed that the modified NSPT paired with the domestic use of nitradine-based formula helps resolve peri-implant mucositis and that nitradine might represent an alternative to chlorhexidine in these cases. CLINICAL RELEVANCE: The gold standard for nonsurgical maintenance is full-mouth disinfection. A previous decontamination of the oral cavity with chlorhexidine or nitradine domiciliary for 10 days could reduce plaque and inflammation, resulting in a painless operative session. This protocol may help reduce airborne contamination and the risk of cross-infection, and during the pandemic, the protocol is safer for clinicians. In the same clinical cases, nitradine may be more efficient than chlorhexidine, and the former has no side effects such as discolouration.","pmid":"34677005","doi":"10.1002/cre2.487","url":"https://pubmed.ncbi.nlm.nih.gov/34677005/"},{"id":878,"title":"Effect of hypochlorous acid nasal spray as an adjuvant therapy after functional endoscopic sinus surgery.","authors":"Jiang, Rong-San; Liang, Kai-Li","year":2022,"date":"2022 Jan-Feb","journal":"American journal of otolaryngology","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"OBJECTIVES: To evaluate the efficacy of hypochlorous acid (HOCl) nasal spray as an adjuvant therapy after functional endoscopic sinus surgery (FESS). MATERIAL AND METHODS: Patients with chronic rhinosinusitis who had received FESS for treatment were recruited and assigned to one of two groups at random at one month post-surgery. In the HOCl group, patients received 0.02% HOCl nasal spray three times a day for two months. In the control group, normal saline (NS) nasal irrigation was given. Before FESS and before and after nasal spray or irrigation, patients completed the Taiwanese version of the 22-item Sino-Nasal Outcome Test (TWSNOT-22). In addition, patients received endoscopic examination, acoustic rhinometry, smell test, saccharine transit test, and bacterial cultures obtained from their middle meatus. RESULTS: Seventy-eight patients completed the study. Among them, 41 received HOCl nasal spray, and 37 received NS irrigation. Endoscopic score significantly decreased after 2-month HOCl nasal spray (p = 0.036). TWSNOT-22 score also decreased, although insignificantly (p = 0.285). In contrast, TWSNOT-22 score significantly decreased after NS nasal irrigation (p = 0.017), but endoscopic score did not significantly decrease (p = 0.142). CONCLUSIONS: Our results showed that HOCl nasal spray had a similar effect to that of NS nasal irrigation in post-FESS care. It can be an alternative of NS nasal irrigation for its convenient application.","pmid":"34653953","doi":"10.1016/j.amjoto.2021.103264","url":"https://pubmed.ncbi.nlm.nih.gov/34653953/"},{"id":879,"title":"Hard-to-heal ulcers treated with hypochlorous acid oxidising solution and standard of care: a 32-week follow-up.","authors":"Ricci, Elia; Pittarello, Monica","year":2021,"date":"2021 Oct 2","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"OBJECTIVE: Immediately following a two-year prospective case series in which the wounds of 60 patients with hard-to-heal ulcers were treated with a hypochlorous acid oxidising solution (AOS) in addition to standard of care (SoC) for 70 days (T0-T70), a subset of 31 patients (51.7%) whose wounds had not fully healed by T70 opted to continue with treatment for a further 22 weeks (days T70-T224, a total treatment time of 32 weeks (224 days). The objective was to provide long-term evidence on the clinical performance and safety of AOS when used in association with the usual SoC in patients with stalled, hard-to-heal ulcers of various aetiologies. METHOD: As per the main study, wounds were formally assessed by the study lead at 28 days (±14 days, depending on patient attendance). Parameters assessed at fortnightly visits included area, depth and duration of ulcer; pain; wound bed preparation (WBP) score; and infection status. Wounds were managed in accordance with the SoC protocol. RESULTS: By T224, 35.5% (n=11) of wounds healed completely and 83.9% showed some types of improvement. All wounds were free of infection and colonisation, the WBP score improved (100% A1-A2 at T196), and pain scores fell. Use of AOS in combination with several types of dressing (SoC) for such a long period confirmed a good safety profile. CONCLUSION: This follow-up evaluation, coupled with the primary study, suggests that AOS might represent a valuable therapeutic addition for the management of hard-to-heal ulcers for long periods of treatment. DECLARATION OF INTEREST: ER worked as a consultant for APR Applied Pharma Research S.A. The authors have no other conflicts of interest.","pmid":"34644135","doi":"10.12968/jowc.2021.30.10.840","url":"https://pubmed.ncbi.nlm.nih.gov/34644135/"},{"id":880,"title":"Wound bed preparation with hypochlorous acid oxidising solution and standard of care: a prospective case series.","authors":"Ricci, Elia; Pittarello, Monica","year":2021,"date":"2021 Oct 2","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"OBJECTIVE: This prospective case series aims to evaluate the clinical impact of a hypochlorous acid oxidising solution (AOS) in association with usual standard of care (SoC) on wound bed preparation (WBP) in patients with hard-to-heal ulcers of various aetiologies. The AOS (Nexodyn, APR Applied Pharma Research S.A., Switzerland) comprises three main features: highly pure and stabilised hypochlorous acid, acidic pH and high reduction-oxidation potential. METHOD: Between February 2015 and February 2017, patients who met the inclusion criteria were treated with AOS and usual SoC. Data collection ran for 70 days: T0-T70. A baseline assessment was undertaken at T0; parameters assessed at fortnightly visits included: WBP score, area and depth of ulcer, duration, pain, Bates-Jensen score and infection status. RESULTS: A total of 60 patients took part in the study. By T70, 68.3% of wounds had healed or improved and a significant wound size reduction of 21% was observed (p<0.001), despite a mean wound duration of 20.6 months. All wounds were free of local infection and cellulitis; 10% were colonised. WBP scores improved, while Bates-Jensen and pain scores fell significantly over time. CONCLUSION: This evaluation suggests that AOS might represent a valuable therapeutic addition for an optimal WBP in the routine management of hard-to-heal ulcers of different aetiologies. DECLARATION OF INTEREST: ER worked as a consultant for APR Applied Pharma Research S.A. The authors have no other conflicts of interest.","pmid":"34644134","doi":"10.12968/jowc.2021.30.10.830","url":"https://pubmed.ncbi.nlm.nih.gov/34644134/"},{"id":882,"title":"Rational design of an HClO-specific triggered self-immolative fluorescent turn-on sensor and its bioimaging applications.","authors":"Wang, Xiao-Bo; Zhang, Da-Long; Li, Hui-Jing; Lu, Xuhao; Liu, Quanze; Wu, Yan-Chao","year":2021,"date":"2021 Nov 3","journal":"Journal of materials chemistry. B","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The development of a rapid and intuitive method for the detection of a specific small molecule biomarker is important for understanding the pathogenesis of relevant diseases. Described here is the design and evaluation of an HClO-specific triggered self-immolative fluorescent sensor (RESClO) based on the structure of an N-protected Resorufin dye. Due to the interrupted π-conjugated structure of the Resorufin dye, the free sensor showed very weak absorption and fluorescence. It can quickly complete the response to HClO (within 10 s) with high selectivity and sensitivity (LOD = 16.8 nM) in aqueous solution. The sensor can be made into test strips to quickly detect HClO in the environment by obvious changes in color and fluorescence. It was successfully used for bioimaging of exogenous and endogenous HClO in cells and zebra fish. More importantly, it can also be used for visual imaging of mouse arthritis models. Thus, sensor RESClO can provide a simple and promising visual analytical tool for the detection of HClO in the environment and the early diagnosis of HClO-mediated related diseases.","pmid":"34632477","doi":"10.1039/d1tb01721g","url":"https://pubmed.ncbi.nlm.nih.gov/34632477/"},{"id":886,"title":"A novel ER-targeted two-photon fluorescent probe for monitoring abnormal concentrations of HClO in diabetic mice.","authors":"Zhang, Weiyao; Song, Wenhui; Lin, Weiying","year":2021,"date":"2021 Sep 22","journal":"Journal of materials chemistry. B","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Diabetes is closely related to the presence of excess HClO induced by endoplasmic reticulum stress. Thus, a novel two-photon fluorescent probe was designed and synthesized for the detection of HClO in the endoplasmic reticulum. Significantly, it has been verified that high glucose can indeed induce oxidative stress of the endoplasmic reticulum and produce excessive HClO. Moreover, the probe has also been successfully used in tissue imaging of diabetic mice.","pmid":"34551059","doi":"10.1039/d1tb01327k","url":"https://pubmed.ncbi.nlm.nih.gov/34551059/"},{"id":888,"title":"Current status of hypochlorite technology on the wastewater treatment and sludge disposal: Performance, principals and prospects.","authors":"Cheng, Xiaoshi; Wang, Suna; Huang, Wenxuan; Wang, Feng; Fang, Shiyu; Ge, Ran; Zhang, Qin; Zhang, Le; Du, Wei; Fang, Fang; Feng, Qian; Cao, Jiashun; Luo, Jingyang","year":2022,"date":"2022 Jan 10","journal":"The Science of the total environment","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"As cost-effective and high-efficient oxidants, the hypochlorite chemicals have been widely utilized for bleaching and disinfection. However, its potential applications in wastewater treatment and sludge disposal were less concerned. This paper mainly summarized the state-of-the-art applications of hypochlorite technology in wastewater and sludge treatment based on the main influencing factors and potential mechanisms of hypochlorite treatment. The results indicated that the hypochlorite approaches were not only effective in pollutants removal and membrane fouling mitigation for wastewater treatment, but also contributed to sludge dewatering and resource recovery for sludge disposal. The ClO(-) and large generated free active radicals (i.e., reactive chlorine species and reactive oxygen species), which possessed strong oxidative ability, were the primary contributors to the pollutants decomposition, and colloids/microbes flocs disintegration during the hypochlorite treatment process. The performance of hypochlorite treatment was highly associated with various factors (i.e., pH, temperature, hypochlorite types and dosage). In combination with the reasonable activators (i.e., Fe(2+) and ultraviolet), auxiliary agents, and innovative processes (i.e., hydrothermal and electro-oxidation), the operational performance of hypochlorite technology could be further enhanced. Finally, the feasibility and benefits of hypochlorite application for wastewater and sludge treatment were analyzed, and the existing challenges and future research efforts that need to be made have also prospected. The review can hopefully provide a theoretical basis and technical guidance to extend the application of hypochlorite technology for wastewater treatment and sludge disposal on large scale.","pmid":"34525771","doi":"10.1016/j.scitotenv.2021.150085","url":"https://pubmed.ncbi.nlm.nih.gov/34525771/"},{"id":892,"title":"One-step synthesis of nitrogen-doped multi-emission carbon dots and their fluorescent sensing in HClO and cellular imaging.","authors":"Wang, Chunxia; Pan, Caiwen; Wei, Zitong; Liu, Ji; Song, Zhaoyi; Ma, Wenjun; Wang, Ming; Mao, Lanqun","year":2021,"date":"2021 Sep 8","journal":"Mikrochimica acta","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Tunable multicolor carbon dots (CDs) with a quantum yield reach up to 35% were generated directly from rhodamine and urea via one-step hydrothermal approach and purified through silica gel column chromatography. Transmission electron microscopy images reveal that the as-prepared CDs possess a small size distribution below 10 nm with bright blue, green, and yellow color emission, designated as b-CDs, g-CDs, and y-CDs, respectively. The in-depth investigations reveal that the multicolor emission CDs with different fraction displays fluorescence emission wavelength ranges from 398 nm (b-CDs), 525 nm (g-CDs), to 553 nm (y-CDs) which could be well modulated by controlling the amount of heteroatom nitrogen especially amino nitrogen onto their surface structures. Further experiments verify the important role of nitrogen content by using rhodamine solely or substituting urea with sulfur containing compounds as precursors to produce corresponding CDs since the performance is lower than that of urea incorporation. Theoretical calculation results also reveal that the increasing amount of amino nitrogen into their surface structures of b-CDs, g-CDs to y-CDs is responsible for reduced band gaps energy, which result in the redshifted wavelength. Benefiting from the excellent photoluminescence properties, wide pH variation range, high photo stability, and low toxicity, these CDs were employed for HClO sensing at 553 nm within the range 5 to 140 μM with a limit of detection (LOD) of 0.27 ± 0.025 μM (n = 3) and multicolor cellular imaging in HeLa cells. Tunable multicolor carbon dots (CDs) were generated directly from rhodamine and urea via one-step hydrothermal approach and purified through silica gel column chromatography. The as-prepared CDs exhibit bright blue, green, and yellow color emission which could be well modulated by controlling the increasing incorporation of heteroatom nitrogen especially amino nitrogen into their surface structures. These CDs were employed for HClO sensing and demonstrated to multicolor cellular imaging in HeLa cells.","pmid":"34498123","doi":"10.1007/s00604-021-04973-0","url":"https://pubmed.ncbi.nlm.nih.gov/34498123/"},{"id":893,"title":"Hypochlorous acid solution is a potent antiviral agent against SARS-CoV-2.","authors":"Hatanaka, Noritoshi; Yasugi, Mayo; Sato, Tomoko; Mukamoto, Masafumi; Yamasaki, Shinji","year":2022,"date":"2022 Feb","journal":"Journal of applied microbiology","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"AIM: A novel coronavirus, termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) suddenly appeared in Wuhan, China, and has caused pandemic. In this study, we evaluated antiviral activity of purified hypochlorous acid (HClO) against coronaviruses such as SARS-CoV-2 and transmissible gastroenteritis virus (TGEV) responsible for pig diseases. MATERIALS AND RESULTS: In a suspension test, 28.1 ppm HClO solution inactivated SARS-CoV-2 in phosphate-buffered saline with the reduction of 10(4) of 50% tissue culture infectious dose per ml (TCID(50) per ml) within 10 s. When its concentration increased to 59.4 ppm, the virus titre decreased to below the detection limit (reduction of 5 logs TCID(50) ) within 10 s even in the presence of 0.1% foetal bovine serum. In a carrier test, incubation with 125 ppm HClO solution for 10 min or 250 ppm for 5 min inactivated SARS-CoV-2 by more than 4 logs TCID(50) per ml or below the detection limit. Because the titre of TGEV was 10-fold higher, TGEV was used for SARS-CoV-2 in a suspension test. As expected, 56.3 ppm HClO solution inactivated TGEV by 6 logs TCID(50) within 30 s. CONCLUSIONS: In a carrier test, 125 ppm HClO solution for 10 min incubation is adequate to inactivate 4 logs TCID(50) per ml of SARS-CoV-2 or more while in a suspension test 56.3 ppm HClO is adequate to inactivate 5 logs TCID(50) per ml of SARS-CoV-2 when incubated for only 10 s regardless of presence or absence of organic matter. SIGNIFICANCE AND IMPACT OF THE STUDY: Effectiveness of HClO solution against SARS-CoV-2 was demonstrated by both suspension and carrier tests. HClO solution inactivated SARS-CoV-2 by 5 logs TCID(50) within 10 s. HClO solution has several advantages such as none toxicity, none irritation to skin and none flammable. Thus, HClO solution can be used as a disinfectant for SARS-CoV-2.","pmid":"34480823","doi":"10.1111/jam.15284","url":"https://pubmed.ncbi.nlm.nih.gov/34480823/"},{"id":902,"title":"Effect of Mechanical Debridement and Irrigation With Hypochlorous Acid Wound Management Solution on Methicillin-resistant Staphylococcus aureus Contamination and Healing Deep Dermal Wounds in a Porcine Model.","authors":"Davis, Stephen C; Gil, Joel; Li, Jie; Simms, Colin; Valdes, Jose; Solis, Michael; Higa, Alexander","year":2021,"date":"2021 Aug","journal":"Wound management & prevention","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"BACKGROUND: Wound cleansing is an important component of wound management. PURPOSE: This study was conducted to examine the effect of a wound management solution (WMS) containing hypochlorous acid (HOCl) on methicillin-resistant Staphylococcus aureus (MRSA) and healing when used in conjunction with debridement. METHODS: Nineteen (19) deep reticular dermal wounds (22 mm × 22 mm × 3 mm deep) were created on the paravertebral and thoracic areas of 3 female pigs using a specialized electrokeratome. Wounds were separated by at least 5 cm to 7 cm of unwounded skin and inoculated with MRSA. After 72 hours, all wounds were debrided with a curette and irrigated with either the WMS or sterile saline solution twice per day from day 0 to day 4. Wounds then were irrigated once a day until the completion of the study (day 11). Wound tissue specimens were taken using punch biopsy for microbiological and histological analysis on days 4, 8, and 11 post treatment. Percent of wound epithelialized, epithelial thickness (cell layers µm), white cell infiltrate (1 = absent, 2 = mild, 3 = moderate, 4 = marked, 5 = exuberant), and percent of granulation tissue formation were calculated and assessed. Microbiology and histology results were analyzed for significant differences between treatments and among assessment days using one-way analysis of variance and student t-tests. A P value ≤ .05 was considered significant. RESULTS: The WMS effected a bacterial reduction (P ≤ .05) of more than 2.74 ± 0.43 and 1.03 ± 0.22 Log CFU/g in all assessment days compared with baseline before and after debridement, respectively. Percent epithelialization was significantly different between treatments on day 8, only 78.3% and 67.8% for HOCl and saline, respectively (P ≤ .05). No significant differences between treatments were observed for epithelial thickness or granulation tissue formation. CONCLUSION: The combination of debridement and HOCl wound irrigation can significantly reduce MRSA contamination and facilitate the healing process compared to saline irrigation. Clinical studies are needed to confirm these results.","pmid":"34370678","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/34370678/"},{"id":904,"title":"Hypochlorous acid initiated lipid chlorination at air-water interface.","authors":"Guo, Changlu; Yang, Miao; He, Jing; Kan, Guangfeng; Yu, Kai; Liu, Zhuo; Lin, Sifan; Jiang, Jie; Zhang, Hong","year":2021,"date":"2021 Dec 1","journal":"The Science of the total environment","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"There has been a surge of interest in interfacial hypochlorous acid (HOCl) chemistry for indoor air quality and public health. Here we combined nanoelectrospray mass spectrometry (nESI-MS) and acoustic levitation (AL) techniques to study the chlorination chemistry of three model lipids (DPPE, POPG, DOPG) mediated by HOCl at the air-water interface of levitated water droplet. For DPPE with no CC double bonds, HOCl was insensitive to the alkane chains, and showed considerable delay directing to head amino groups compared to that in aqueous environment. Chlorination chemistry, for POPG and DOPG with CC double bonds, preferentially reacted with double bonds of one chain. The mechanism was discussed in light of these observations, and it is concluded that the increased hydrophilicity of the chlorinated chain disturbed the lipid packing and attracted it toward the water phase. In addition, the reaction rate constant and reactive uptake coefficient suggested that the chlorination of lipids exposed to HOCl at the air-water interface is likely to occur rapidly. These results gain the knowledge of HOCl mediated lipid interface reaction at the molecule level, and would better understand the adverse health effects associated with elevated indoor pollutants.","pmid":"34340067","doi":"10.1016/j.scitotenv.2021.149320","url":"https://pubmed.ncbi.nlm.nih.gov/34340067/"},{"id":906,"title":"Melatonin interferes with COVID-19 at several distinct ROS-related steps.","authors":"Camp, Olivia G; Bai, David; Gonullu, Damla C; Nayak, Neha; Abu-Soud, Husam M","year":2021,"date":"2021 Oct","journal":"Journal of inorganic biochemistry","category":"Food & agriculture","evidence":"Review","relevance":"High","abstract":"Recent studies have shown a correlation between COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and the distinct, exaggerated immune response titled \"cytokine storm\". This immune response leads to excessive production and accumulation of reactive oxygen species (ROS) that cause clinical signs characteristic of COVID-19 such as decreased oxygen saturation, alteration of hemoglobin properties, decreased nitric oxide (NO) bioavailability, vasoconstriction, elevated cytokines, cardiac and/or renal injury, enhanced D-dimer, leukocytosis, and an increased neutrophil to lymphocyte ratio. Particularly, neutrophil myeloperoxidase (MPO) is thought to be especially abundant and, as a result, contributes substantially to oxidative stress and the pathophysiology of COVID-19. Conversely, melatonin, a potent MPO inhibitor, has been noted for its anti-inflammatory, anti-oxidative, anti-apoptotic, and neuroprotective actions. Melatonin has been proposed as a safe therapeutic agent for COVID-19 recently, having been given with a US Food and Drug Administration emergency authorized cocktail, REGEN-COV2, for management of COVID-19 progression. This review distinctly highlights both how the destructive interactions of HOCl with tetrapyrrole rings may contribute to oxygen deficiency and hypoxia, vitamin B12 deficiency, NO deficiency, increased oxidative stress, and sleep disturbance, as well as how melatonin acts to prevent these events, thereby improving COVID-19 prognosis.","pmid":"34304092","doi":"10.1016/j.jinorgbio.2021.111546","url":"https://pubmed.ncbi.nlm.nih.gov/34304092/"},{"id":908,"title":"Loss of mTORC2 Activity in Neutrophils Impairs Fusion of Granules and Affects Cellular Metabolism Favoring Increased Bacterial Burden in Sepsis.","authors":"Breda, Cristiane Naffah de Souza; Breda, Leandro Carvalho Dantas; Carvalho, Larissa Anastácio da Costa; Amano, Mariane Tami; Terra, Fernanda Fernandes; Silva, Reinaldo Correia; Fragas, Matheus Garcia; Forni, Maria Fernanda; Fonseca, Monique Thaís Costa; Venturini, Gabriela; Feitosa, Amanda Campelo Melo; Ghirotto, Bruno; Cruz, Mario Costa; Cunha, Flávia Franco; Ignacio, Aline; Latância, Marcela; Castoldi, Angela; Andrade-Oliveira, Vinícius; Martins da Silva, Eloisa; Hiyane, Meire Ioshie; Pereira, Alexandre da Costa; Festuccia, William; Meotti, Flávia Carla; Câmara, Niels Olsen Saraiva","year":2021,"date":"2021 Jul 15","journal":"Journal of immunology (Baltimore, Md. : 1950)","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Sepsis is a complex infectious syndrome in which neutrophil participation is crucial for patient survival. Neutrophils quickly sense and eliminate the pathogen by using different effector mechanisms controlled by metabolic processes. The mammalian target of rapamycin (mTOR) pathway is an important route for metabolic regulation, and its role in neutrophil metabolism has not been fully understood yet, especially the importance of mTOR complex 2 (mTORC2) in the neutrophil effector functions. In this study, we observed that the loss of Rictor (mTORC2 scaffold protein) in primary mouse-derived neutrophils affects their chemotaxis by fMLF and their microbial killing capacity, but not the phagocytic capacity. We found that the microbicidal capacity was impaired in Rictor-deleted neutrophils because of an improper fusion of granules, reducing the hypochlorous acid production. The loss of Rictor also led to metabolic alterations in isolated neutrophils, increasing aerobic glycolysis. Finally, myeloid-Rictor-deleted mice (LysMRic Δ/Δ) also showed an impairment of the microbicidal capacity, increasing the bacterial burden in the Escherichia coli sepsis model. Overall, our results highlight the importance of proper mTORC2 activation for neutrophil effector functions and metabolism during sepsis.","pmid":"34261666","doi":"10.4049/jimmunol.2000573","url":"https://pubmed.ncbi.nlm.nih.gov/34261666/"},{"id":910,"title":"Valorization of high-salinity effluents for CO(2) fixation and hypochlorite generation.","authors":"Acosta-Santoyo, Gustavo; León-Fernández, Luis F; Bustos, Erika; Cañizares, Pablo; Rodrigo, M A; Llanos, Javier","year":2021,"date":"2021 Dec","journal":"Chemosphere","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"In this work, it is evaluated the fixation of carbon dioxide using the alkali generated in the chloralkaline process, as a new way to face the treatment of highly saline wastewater, in which it is aimed not to separate the wastewater into concentrated and diluted streams but to recover value-added products (VAPs) while contributing to minimize the carbon fingerprint of other processes. The electrolytic process is combined with a reactive absorption and with a crystallization, demonstrating the formation of pure nahcolite, hypochlorite (or chlorine) and hydrogen from the waste. Carbon dioxide is captured with a current efficiency over 90% and the energy required is around 0.65 kWh kg(-1), which is very promising from the view point of sustainability, considering that the system can be easily powered with green energies.","pmid":"34246099","doi":"10.1016/j.chemosphere.2021.131359","url":"https://pubmed.ncbi.nlm.nih.gov/34246099/"},{"id":911,"title":"Hypochlorous Acid Versus Saline Nasal Irrigation in Allergic Rhinitis: A Multicenter, Randomized, Double-Blind, Placebo-controlled Study.","authors":"Kim, Ho Chan; Kim, Dong-Kyu; Kim, Ji Sun; Lee, Ho Jun; Bae, Mi Rye; Choi, Woo Ri; Jang, Yong Ju","year":2022,"date":"2022 Jan","journal":"American journal of rhinology & allergy","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"BACKGROUND: Low concentrations of hypochlorous acid (HOCl) have proven antipruritic, anti-inflammatory, and antimicrobial effects without toxicity, although the mechanism has not been fully elucidated. OBJECTIVE: The aim of this study was to evaluate the effectiveness of HOCl nasal irrigation to reduce allergic rhinitis (AR) symptoms compared with saline nasal irrigation. METHODS: This was multicenter, randomized, double-blind, placebo-controlled study. Initially, 139 patients with perennial AR were enrolled; however, 25 did not successfully complete the study. Patients were randomly assigned to the nasal irrigation with low-concentration HOCl (n = 55) or normal saline (n = 59) treatment groups for the 4-week study period. Participants completed the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) at every visit (baseline, Weeks 2 and 4), and Total Nasal Symptom Score (TNSS) was determined before and after nasal irrigation every morning and evening. RESULTS: We found that RQLQ scores significantly decreased after 4 weeks in the HOCl and placebo groups, but the decrement of the RQLQ score was similar between the 2 groups. Additionally, TNSS improved in both groups between baseline and Week 4, whereas there were no significant differences in the change of TNSS between the 2 groups. The HOCl group did not show any clinical side effects related to nasal irrigation. CONCLUSION: Allergic symptoms significantly decreased with low-concentration HOCl nasal irrigation, without significant adverse events. However, HOCl showed no additional improvement in symptoms compared with saline nasal irrigation for patients with perennial AR.","pmid":"34236253","doi":"10.1177/19458924211029428","url":"https://pubmed.ncbi.nlm.nih.gov/34236253/"},{"id":914,"title":"Secondary Effects of Hypochlorite Treatment on the Emerging Pollutant Candesartan: The Formation of Degradation Byproducts and Their Toxicological Profiles.","authors":"Luongo, Giovanni; Saviano, Lorenzo; Libralato, Giovanni; Guida, Marco; Siciliano, Antonietta; Previtera, Lucio; Di Fabio, Giovanni; Zarrelli, Armando","year":2021,"date":"2021 Jun 5","journal":"Molecules (Basel, Switzerland)","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"In recent years, many studies have reported the frequent detection of antihypertensive agents such as sartans (olmesartan, valsartan, irbesartan and candesartan) in the influents and effluents of wastewater treatment plants (WWTPs) and in the superficial waters of rivers and lakes in both Europe and North America. In this paper, the degradation pathway for candesartan (CAN) was investigated by simulating the chlorination process that is normally used to reduce microbial contamination in a WWTP. Twelve isolated degradation byproducts (DPs), four of which were isolated for the first time, were separated on a C-18 column by employing a gradient HPLC method, and their structures were identified by combining nuclear magnetic resonance and mass spectrometry and comparing the results with commercial standards. On the basis of these results, a mechanism of formation starting from the parent drug is proposed. The ecotoxicity of CAN and its DPs was studied by conducting a battery of ecotoxicity tests; bioassays were performed using Aliivibrio fischeri (bacterium), Daphnia magna (planktonic crustacean) and Raphidocelis subcapitata (alga). The ecotoxicity results shed new light on the increased toxicity of DPs compared with the parent compound.","pmid":"34198752","doi":"10.3390/molecules26113422","url":"https://pubmed.ncbi.nlm.nih.gov/34198752/"},{"id":917,"title":"Degradation of carbamazepine by UVA/WO(3)/hypochlorite process: Kinetic modelling, water matrix effects, and density functional theory calculations.","authors":"Ding, Han; Hu, Jiangyong","year":2021,"date":"2021 Oct","journal":"Environmental research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The rapid recombination of electron/hole pairs is a major setback in the application of WO(3)-based photocatalysis in water treatment. In this study, hypochlorite (ClO(-)) was used as an electron acceptor to enhance the photocatalytic degradation of carbamazepine (CBZ) using UVA-excited WO(3). The results showed that CBZ degradation in the UVA/WO(3)/ClO(-) system followed a pseudo-first order reaction kinetic model. The addition of 0.1 mM ClO(-) to the UVA/WO(3) system at pH values of 8.2 and 6.2 increased the rate constant (k(obs)) of the degradation process 5.3- and 11.5-fold, respectively. Further, increasing the WO(3) dosage or decreasing the initial CBZ concentration resulted in an increase in k(obs). However, at high concentrations, ClO(-) inhibited CBZ degradation. Based on the kinetic model, it could be suggested that ClO played a dominant role in the degradation process. Furthermore, the water matrix effects were as follows: the optimal pH was 6.2; humic acid, chloride, bicarbonate, and ammonium exhibited inhibitory effects on CBZ degradation; and sulfate ion significantly enhanced the degradation. Density functional theory (DFT) calculations indicated a strong affinity between ClO(-) and the WO(3) surface. Specifically, the electrical energy per order that was associated with the use of ClO(-) varied in the range of 0.100-1.617 kWh/m(3). In summary, this study shows that ClO(-) is an excellent electron acceptor for excited WO(3), while clarifying the CBZ degradation-enhancing effect of ClO(-) as well as the kinetic model and DFT calculations. These findings can be employed in the degradation of recalcitrant contaminants in a cost-effective manner, while being significant for the development of more effective catalysts of UV-assisted advanced oxidation processes.","pmid":"34186085","doi":"10.1016/j.envres.2021.111569","url":"https://pubmed.ncbi.nlm.nih.gov/34186085/"},{"id":918,"title":"Antibiofilm Efficacy of Polihexanide, Octenidine and Sodium Hypochlorite/Hypochlorous Acid Based Wound Irrigation Solutions against Staphylococcus aureus, Pseudomonas aeruginosa and a Multispecies Biofilm.","authors":"Salisbury, Anne-Marie; Mullin, Marc; Chen, Rui; Percival, Steven L","year":2022,"date":"2022","journal":"Advances in experimental medicine and biology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Infection and the formation of biofilms have been shown to have a significant role in increased inflammation and delayed wound healing. Wound irrigation solutions are used to debride wounds, removing cell debris and infecting microorganisms, therefore preventing infection. The aim of this study was to evaluate a Polihexanide (PHMB) based wound irrigation solution, Octenidine HCl based wound irrigation solution and electrolysed water based wound care solution for antibiofilm efficacy against Staphylococcus aureus, Pseudomonas aeruginosa and a multispecies biofilm in several models to gain a broad understanding of ability. The PHMB based wound irrigation solution demonstrated broad range antibiofilm efficacy against P. aeruginosa, S. aureus and the multispecies biofilm. The Octenidine HCl based wound irrigation solution and the electrolysed water based wound care solution demonstrated potent antibiofilm efficacy against S. aureus and to a lesser extent P. aeruginosa. Overall, less efficacy was observed in the drip flow bioreactor model for all 3 test solutions, which may be attributed to the continuous flow of nutrients during treatment, which may have diluted or washed away the solution. The data presented also highlights the importance of testing antibiofilm activity in a range of biofilm models and against different bacterial strains to get an overall representation of efficacy.","pmid":"34173213","doi":"10.1007/5584_2021_645","url":"https://pubmed.ncbi.nlm.nih.gov/34173213/"},{"id":920,"title":"A Bacterial Inflammation Sensor Regulates c-di-GMP Signaling, Adhesion, and Biofilm Formation.","authors":"Perkins, Arden; Tudorica, Dan A; Teixeira, Raphael D; Schirmer, Tilman; Zumwalt, Lindsay; Ogba, O Maduka; Cassidy, C Keith; Stansfeld, Phillip J; Guillemin, Karen","year":2021,"date":"2021 Jun 29","journal":"mBio","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Bacteria that colonize animals must overcome, or coexist, with the reactive oxygen species products of inflammation, a front-line defense of innate immunity. Among these is the neutrophilic oxidant bleach, hypochlorous acid (HOCl), a potent antimicrobial that plays a primary role in killing bacteria through nonspecific oxidation of proteins, lipids, and DNA. Here, we report that in response to increasing HOCl levels, Escherichia coli regulates biofilm production via activation of the diguanylate cyclase DgcZ. We identify the mechanism of DgcZ sensing of HOCl to be direct oxidation of its regulatory chemoreceptor zinc-binding (CZB) domain. Dissection of CZB signal transduction reveals that oxidation of the conserved zinc-binding cysteine controls CZB Zn(2+) occupancy, which in turn regulates the catalysis of c-di-GMP by the associated GGDEF domain. We find DgcZ-dependent biofilm formation and HOCl sensing to be regulated in vivo by the conserved zinc-coordinating cysteine. Additionally, point mutants that mimic oxidized CZB states increase total biofilm. A survey of bacterial genomes reveals that many pathogenic bacteria that manipulate host inflammation as part of their colonization strategy possess CZB-regulated diguanylate cyclases and chemoreceptors. Our findings suggest that CZB domains are zinc-sensitive regulators that allow host-associated bacteria to perceive host inflammation through reactivity with HOCl. IMPORTANCE Immune cells are well equipped to eliminate invading bacteria, and one of their primary tools is the synthesis of bleach, hypochlorous acid (HOCl), the same chemical used as a household disinfectant. In this work, we present findings showing that many host-associated bacteria possess a bleach-sensing protein that allows them to adapt to the presence of this chemical in their environment. We find that the bacterium Escherichia coli responds to bleach by hunkering down and producing a sticky matrix known as biofilm, which helps it aggregate and adhere to surfaces. This behavior may play an important role in pathogenicity for E. coli and other bacteria, as it allows the bacteria to detect and adapt to the weapons of the host immune system.","pmid":"34154415","doi":"10.1128/mBio.00173-21","url":"https://pubmed.ncbi.nlm.nih.gov/34154415/"},{"id":921,"title":"Comparison of the SARS-CoV-2-inactivating activities of the differently manufactured hypochlorous acid water products with various pH.","authors":"Takeda, Yohei; Matsuda, Sachiko; Jamsransuren, Dulamjav; Ogawa, Haruko","year":2021,"date":"2021 Jun","journal":"Journal of water and health","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The use of effective disinfectants is a key method of controlling the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hypochlorous acid water (HAW) has a broad spectrum of virucidal activities. We previously reported that acidic electrolyzed water, one of the HAW products, had potent SARS-CoV-2-inactivating activity and showed promise as a disinfectant. However, different manufacturing methods have produced several HAW products with various pH values. Here, we compared the SARS-CoV-2-inactivating activities of various HAW products. At sufficiently high volume and residual chlorine concentration (RCC), the HAW products inactivated SARS-CoV-2 efficiently regardless of pH or manufacturing method. However, although HAW products at pH 5.0-6.4 maintained high RCC and sustained virucidal activity for 21 days, the RCC rapidly decreased in HAW products at pH ≤ 3.0. Our results may guide in choosing appropriate HAW products for different usage situations.","pmid":"34152297","doi":"10.2166/wh.2021.260","url":"https://pubmed.ncbi.nlm.nih.gov/34152297/"},{"id":924,"title":"Topical hypochlorous acid (HOCl) blocks inflammatory gene expression and tumorigenic progression in UV-exposed SKH-1 high risk mouse skin.","authors":"Jandova, Jana; Snell, Jeremy; Hua, Anh; Dickinson, Sally; Fimbres, Jocelyn; Wondrak, Georg T","year":2021,"date":"2021 Sep","journal":"Redox biology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HOCl) is the active oxidizing principle underlying drinking water disinfection, also delivered by numerous skin disinfectants and released by standard swimming pool chemicals used on a global scale, a topic of particular relevance in the context of the ongoing COVID-19 pandemic. However, the cutaneous consequences of human exposure to HOCl remain largely unknown, posing a major public health concern. Here, for the first time, we have profiled the HOCl-induced stress response in reconstructed human epidermis and SKH-1 hairless mouse skin. In addition, we have investigated the molecular consequences of solar simulated ultraviolet (UV) radiation and HOCl combinations, a procedure mimicking co-exposure experienced for example by recreational swimmers exposed to both HOCl (pool disinfectant) and UV (solar radiation). First, gene expression elicited by acute topical HOCl exposure was profiled in organotypic human reconstructed epidermis. Next, co-exposure studies (combining topical HOCl and UV) performed in SKH-1 hairless mouse skin revealed that the HOCl-induced cutaneous stress response blocks redox and inflammatory gene expression elicited by subsequent acute UV exposure (Nos2, Ptgs2, Hmox1, Srxn1), a finding consistent with emerging clinical evidence in support of a therapeutic role of topical HOCl formulations for the suppression of inflammatory skin conditions (e.g. atopic dermatitis, psoriasis). Likewise, in AP-1 transgenic SKH-1 luciferase-reporter mice, topical HOCl suppressed UV-induced inflammatory signaling assessed by bioluminescent imaging and gene expression analysis. In the SKH-1 high-risk mouse model of UV-induced human keratinocytic skin cancer, topical HOCl blocked tumorigenic progression and inflammatory gene expression (Ptgs2, Il19, Tlr4), confirmed by immunohistochemical analysis including 3-chloro-tyrosine-epitopes. These data illuminate the molecular consequences of HOCl-exposure in cutaneous organotypic and murine models assessing inflammatory gene expression and modulation of UV-induced carcinogenesis. If translatable to human skin these observations provide novel insights on molecular consequences of chlorination stress relevant to environmental exposure and therapeutic intervention.","pmid":"34144392","doi":"10.1016/j.redox.2021.102042","url":"https://pubmed.ncbi.nlm.nih.gov/34144392/"},{"id":925,"title":"High concentrations of hypochlorous acid-based disinfectant in the environment reduced the load of SARS-CoV-2 in nucleic acid amplification testing.","authors":"Duan, Xiuzhi; Wang, Xuchu; Xie, Yiyi; Yu, Pan; Zhuang, Tingting; Zhang, Yingzhi; Fang, Liuyu; Ping, Ying; Liu, Weiwei; Tao, Zhihua","year":2021,"date":"2021 Aug","journal":"Electrophoresis","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"During the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic, chlorine-containing disinfectants have been widely used in nucleic acid amplification testing laboratories. Whether the use of disinfectants affect the results of viral nucleic acid amplification is unknown. We examined the impact of different hypochlorous acid (HOCl) concentrations on the quantitative results of SARS-CoV-2 by real-time reverse-transcription polymerase chain reaction (RT-PCR). We also explored the mechanisms and models of action of chlorine-containing disinfectants that affected the detection of SARS-CoV-2. The results showed that different HOCl concentrations and different action times had an impact on the SARS-CoV-2 results. High concentrations of ambient HOCl have a greater impact than low concentrations, and this effect will increase with the extension of the action time and with the increase in ambient humidity. Compared with the enzymes or the extracted RNA required for RT-PCR, the impact of HOCl on the SARS-CoV-2 detection is more likely to be caused by damage to primers and probes in the PCR system. The false negative result still existed after changing the ambient disinfectant to ethanol but not peracetic acid. The use of HOCl in the environment will have an unpredictable impact on the nucleic acid test results of SARS-CoV-2. In order to reduce the possibility of false negative of SARS-CoV-2 nucleic acid test and prevent the spread of epidemic disease, environmental disinfectants should be used at the beginning and end of the experiment rather than during the experimental operation.","pmid":"34142386","doi":"10.1002/elps.202000387","url":"https://pubmed.ncbi.nlm.nih.gov/34142386/"},{"id":926,"title":"Efficacy of Hypochlorite in Disinfesting Nonfungal Plant Pathogens in Agricultural and Horticultural Plant Production: A Meta-Analysis.","authors":"Copes, Warren E; Ojiambo, Peter S","year":2021,"date":"2021 Dec","journal":"Plant disease","category":"Food & agriculture","evidence":"Systematic review / meta-analysis","relevance":"High","abstract":"Bleach products containing hypochlorite are commonly used as disinfectants to eliminate nonfungal plant pathogens from production surfaces, tools, plant surfaces, irrigation water, and produce dump tanks. Although bleach products are useful, their effectiveness has been reported to vary under specific settings. A meta-analysis was conducted of 86 studies to assess the overall efficacy of hypochlorite against plant pathogenic bacteria, oomycetes, and viruses and to identify factors that explain differences in product efficacy. Hypochlorite resulted in a significant (P < 0.0001) reduction in disease intensity or propagule viability, with a mean Hedges' g standardized difference ([Formula: see text]) of 3.01, indicating that overall, hypochlorite treatments are highly effective. However, heterogeneity in g was significant (P < 0.0001) between studies, wherein 69.8% of the variance observed in g was attributed to true effects. Furthermore, an estimate of between-study variability was moderate (τ(2) = 1.46). Random effects (REs) metaregression showed limited effects of moderator variables dosage, contact time, targeted material of treatment, and organism type on product efficacy when all organism types were considered together. Because subgroup [Formula: see text] was significantly higher (P = 0.0070) for oomycetes ([Formula: see text] = 3.30) than for bacteria ([Formula: see text] = 2.19), subsequent metaregressions were performed by organism type. For oomycetes, five RE metaregression models, each containing two moderators and their interaction, resulted in significant (P = 0.05) effects, where models with dosage and time, dosage and genus, time and genus, dosage and target, and time and target accounted for ≤50, 71, 57, 48, and 47%, respectively, of the variance in true effect sizes (R(2)) associated with [Formula: see text]. For viruses, only the RE metaregression model containing time and target and their interaction resulted in significant (P = 0.0435) effects accounting for 38% of the variance in true effect sizes associated with [Formula: see text]. None of the RE metaregression models for bacteria were significant, although they still accounted for ≤28% of the variance in true effect sizes associated with [Formula: see text]. These results show that although the current recommended rates for dosage and contact time for commercial bleach products are generally expected to result in effective disinfestation, the efficacy against nonfungal plant pathogens is expected to be influenced by the organism type and target being treated with hypochlorite.","pmid":"34129349","doi":"10.1094/PDIS-09-20-2046-RE","url":"https://pubmed.ncbi.nlm.nih.gov/34129349/"},{"id":927,"title":"Debriding effect of amino acid-buffered hypochlorite on hard-to-heal wounds covered by devitalised tissue: pilot study.","authors":"Eliasson, Björn; Fagerdahl, Ann-Mari; Jönsson, Anders; Apelqvist, Jan","year":2021,"date":"2021 Jun 2","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"OBJECTIVE: Wounds such as lower extremity ulcers are serious, costly and frequently hard to heal. Guidelines conclude that new dressings and treatments generally fail to show superiority compared with standard of care. Several mechanisms are probably responsible for impaired healing of hard-to-heal wounds, including inflammation and infection. Amino acid-buffered hypochlorite has presumed antiseptic and antibacterial properties and has been shown to be useful in the treatment of diabetic foot ulcers (DFUs). We evaluated the debriding effect of amino acid-buffered hypochlorite (ChloraSolv) on full skin hard-to-heal lower extremity ulcers covered with devitalised tissue (≥50%), with six applications over 5 weeks and follow-up at 12 weeks. METHOD: This was an open-label, single-arm, multicentre, pre-market pilot investigation. We recruited subjects with a lower extremity ulcer, covered with devitalised tissue (≥50%), who were candidates for cleansing and debridement/desloughing. There was a weekly application of the investigational device for five weeks. Follow-up for wound status evaluation was performed at 12 weeks from baseline. RESULTS: We evaluated 57 subjects (33 males, 24 females, median age 73 years, range 51-90 years) (intention-to-treat). Of these, 61.4% had a leg ulcer and 38.6% a foot ulcer. The median wound size at baseline was 7.7cm(2) (range 2.1-52cm(2)) with devitalised tissue coverage of 76.5%. After 5 weeks, a decrease of 72.7% in devitalised tissue was seen, and 71.4% of the subjects showed a decrease in devitalised tissue of ≥50% (evaluated independently using PictZar). At 12 weeks' follow-up the decrease in devitalised tissue was 84.4%. Wound-related pain was reported by ten subjects, resulting in 17 adverse events (AEs). Among these, 12 AEs from eight subjects were recorded as possibly or probably related to the investigational device and one AE was reported to have a causal relationship with the investigational device. CONCLUSION: This clinical study suggests that amino acid-buffered hypochlorite can be effective and well tolerated in the treatment of hard-to-heal lower extremity ulcers to dissolve and remove devitalised tissue.","pmid":"34121441","doi":"10.12968/jowc.2021.30.6.455","url":"https://pubmed.ncbi.nlm.nih.gov/34121441/"},{"id":928,"title":"A phenothiazine coumarin based ratiometric fluorescent probe for real-time detection of lysosomal hypochlorite in living cell and zebra fish.","authors":"Liu, Jiaojiao; Niu, Peixin; Rong, Yifan; Chen, Wenqiang; Liu, Xingjiang; Wei, Liuhe; Song, Xiangzhi","year":2021,"date":"2021 Nov 15","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Hypochlorite (ClO(-)), a type of reactive oxygen species (ROS), plays an essential role in complex biological systems. Real-time detection of the content and distribution of ClO(-) in cells or subcellular organelle is critically essential. In this paper, a lysosomal-targeted fluorescent probe, Cou-Lyso, was constructed for real-time detection of ClO(-) in a ratiometric manner, achieving high sensitivity with a low detection limit (0.58 μM). Upon reaction with ClO(-), this probe was subjected to a significant fluorescence change from red emission (λ(max)em = 610 nm) to green emission (λ(max)em = 535 nm) with the ratio of I(535 nm)/I(610 nm) displaying a 76-fold enhancement from 0.04 to 3.03. The confocal imaging experiments for Cou-Lyso showed that this probe could detect ClO(-) in living cell and zebra fish. This probe has been successfully applied to stain lysosome and image lysosomal ClO(-) based on co-localization imaging experiments.","pmid":"34119769","doi":"10.1016/j.saa.2021.120024","url":"https://pubmed.ncbi.nlm.nih.gov/34119769/"},{"id":930,"title":"Rational design of AIE-based fluorescent probes for hypochlorite detection in real water samples and live cell imaging.","authors":"Xu, Chenggong; Zhou, Yanmei; Li, Zhaoge; Zhou, Yunhao; Liu, Xiaoqiang; Peng, Xiaojun","year":2021,"date":"2021 Sep 15","journal":"Journal of hazardous materials","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"As one kind of important disinfectant and reactive oxygen species (ROS), hypochlorite (ClO(-)), plays vital roles in both water treatment and cell homeostasis. In this work, by decorating a series of groups with different electron donating and withdrawing properties on tetraphenylethene (TPE), four aggregation-induced emission (AIE)-based fluorescent probes containing C˭C double bonds as the potential reaction sites named Probe A, B, C and D were constructed, and their sensing performance for ClO(-) was systematically studied. The results showed that the substituents can not only effectively tune the photophysical properties of the probes, but also make a significant impact on their sensing performance for ClO(-). Combined with the theoretical calculation results, it can be inferred that the reactivity of the probes for ClO(-) can be greatly enhanced with the increase of electron cloud density on the C˭C double bonds by the introduction of strong electron-donating group (EDG) and electron-withdrawing group (EWG) adjacent to the double bonds. Finally, the best performing Probe D was selected and then successfully applied to ClO(-) detection in real water samples and live cell imaging.","pmid":"34102351","doi":"10.1016/j.jhazmat.2021.126243","url":"https://pubmed.ncbi.nlm.nih.gov/34102351/"},{"id":931,"title":"Evaluation of hydroxyl radical and reactive chlorine species generation from the superoxide/hypochlorous acid reaction as the basis for a novel advanced oxidation process.","authors":"Liou, Sin-Yi; Dodd, Michael C","year":2021,"date":"2021 Jul 15","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The reaction of hypochlorous acid (HOCl) with superoxide radical (O(2)(•)(-)) - a source of hydroxyl radical (HO(•)) and various reactive chlorine species (RCS) - was investigated as the basis for a novel non-photochemical advanced oxidation process (AOP). Moderately stable (t(1/2) ~ minutes) aqueous O(2)(•)(-) stocks were prepared by several approaches at pH>12 and either (a) added directly to aqueous free available chlorine (FAC; i.e., HOCl/OCl(-)) at circumneutral pH, or (b) premixed with alkaline FAC and then acidified to pH 7, to degrade various organic probe compounds via in situ generated HO(•) and RCS. Radical production was optimal at [HO(2)(•)/O(2)(•)(-)](0)/[FAC](0) ~ 2, with ~0.8 mol HO(•) formed/mol FAC consumed, and HO(•) and RCS exposures reaching ~5×10(-10) and ~10(-9) M×s, respectively. Similar trends were observed in natural waters and organic matter-amended phosphate buffer containing up to 5 mgC/L of dissolved organic carbon. Direct formation of oxyhalides, trihalomethanes (THMs), and haloacetic acids (HAAs), was minimal, though THM and HAA formation was moderately enhanced during post-chlorination of O(2)(•)(-)/FAC-treated solutions. This process could provide a beneficial addition to the range of available AOPs due to its high radical exposures, simplicity, rapid time-scales, potential for on-site O(2)(•)(-) generation, and widespread accessibility of FAC and other reagents.","pmid":"34052475","doi":"10.1016/j.watres.2021.117142","url":"https://pubmed.ncbi.nlm.nih.gov/34052475/"},{"id":937,"title":"Deletion of both methionine sulfoxide reductase A and methionine sulfoxide reductase C genes renders Salmonella Typhimurium highly susceptible to hypochlorite stress and poultry macrophages.","authors":"Nair, Sonu S; Chauhan, Tapan Kumar Singh; Kumawat, Manoj; Sarkhel, Ratanti; Apoorva, Shekhar; Shome, Arijit; Athira, V; Kumar, Bablu; Abhishek; Mahawar, Manish","year":2021,"date":"2021 Apr","journal":"Molecular biology reports","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Salmonella Typhimurium survives and replicates inside the oxidative environment of phagocytic cells. Proteins, because of their composition and location, are the foremost targets of host inflammatory response. Among others, Met-residues are highly prone to oxidation. Methionine sulfoxide reductase (Msr), with the help of thioredoxin-thioredoxin reductase, can repair oxidized methionine (Met-SO) residues to Met. There are four methionine sulfoxide reductases localized in the cytosol of S. Typhimurium, MsrA, MsrB, MsrC and BisC. MsrA repairs both protein-bound and free 'S' Met-SO, MsrB repairs protein-bound 'R' Met-SO, MsrC repairs free 'R' Met-SO and BisC repairs free 'S' Met-SO. To assess the role(s) of various Msrs in Salmonella, few studies have been conducted by utilizing ΔmsrA, ΔmsrB, ΔmsrC, ΔmsrAΔmsrB, ΔmsrBΔmsrC and ΔbisC mutant strains of S. Typhimurium. Out of the above-mentioned mutants, ΔmsrA and ΔmsrC were found to play important role in the stress survival of this bacterium; however, the combined roles of these two genes have not been determined. In the current study, we have generated msrAmsrC double gene deletion strain (ΔmsrAΔmsrC) of S. Typhimurium and evaluated the effect of gene deletions on the survival of Salmonella against hypochlorite stress and intramacrophage replication. In in vitro growth curve analysis, ΔmsrAΔmsrC mutant strain showed a longer lag phase during the initial stages of the growth; however, it attained similar growth as the wild type strain of S. Typhimurium after 5 h. The ΔmsrAΔmsrC mutant strain has been highly (~ 3000 folds more) sensitive (p < 0.001) to hypochlorite stress. Further, ΔmsrA and ΔmsrAΔmsrC mutant strains showed more than 8 and 26 folds more susceptibility to poultry macrophages, respectively. Our data suggest that the deletion of both msrA and msrC genes severely affect the oxidative stress survival and intramacrophage proliferation of S. Typhimurium.","pmid":"33954903","doi":"10.1007/s11033-021-06381-2","url":"https://pubmed.ncbi.nlm.nih.gov/33954903/"},{"id":938,"title":"The Safety and Antimicrobial Properties of Stabilized Hypochlorous Acid in Acetic Acid Buffer for the Treatment of Acute Wounds-a Human Pilot Study and In Vitro Data.","authors":"Burian, Ewa A; Sabah, Lubna; Kirketerp-Møller, Klaus; Ibstedt, Elin; Fazli, Magnus M; Gundersen, Glenn","year":2023,"date":"2023 Jun","journal":"The international journal of lower extremity wounds","category":"Water, sanitation & biosecurity","evidence":"Clinical trial","relevance":"High","abstract":"Acute wounds may require cleansing to reduce the risk of infection. Stabilized hypochlorous acid in acetic buffer (HOCl + buffer) is a novel wound irrigation solution with antimicrobial properties. We performed a first-in-man, prospective, open-label pilot study to document preliminary safety and performance in the treatment of acute wounds. The study enrolled 12 subjects scheduled for a split-skin graft transplantation, where the donor site was used as a model of an acute wound. The treatment time was 75 s, given on 6 occasions. A total of 7 adverse events were regarded as related to the treatment; all registered as pain during the procedure for 2 subjects. One subject had a wound infection at the donor site. The mean colony-forming unit (CFU) decreased by 41% after the treatment, and the mean epithelialization was 96% on both days 14 (standard deviation [SD] 8%) and 21 (SD 10%). The study provides preliminary support for the safety, well-tolerance, and efficacy of HOCl + buffer for acute wounds. The pain was frequent although resolved quickly. Excellent wound healing and satisfying antimicrobial properties were observed. A subsequent in vitro biofilm study also indicated good antimicrobial activity against Pseudomonas aeruginosa with a 96% mean reduction of CFU, when used for a treatment duration of 15 min (P < .0001), and a 50% decrease for Staphylococcus aureus (P = .1010). Future larger studies are needed to evaluate the safety and performance of HOCl + buffer in acute wounds, including the promising antimicrobial effect by prolonged treatment on bacterial biofilms.","pmid":"33949232","doi":"10.1177/15347346211015656","url":"https://pubmed.ncbi.nlm.nih.gov/33949232/"},{"id":940,"title":"Hypochlorous acid-modified human serum albumin suppresses MHC class II - dependent antigen presentation in pro-inflammatory macrophages.","authors":"Ulfig, Agnes; Bader, Verian; Varatnitskaya, Marharyta; Lupilov, Natalie; Winklhofer, Konstanze F; Leichert, Lars I","year":2021,"date":"2021 Jul","journal":"Redox biology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Macrophages are innate immune cells that internalize and present exogenous antigens to T cells via MHC class II proteins. They operate at sites of infection in a highly inflammatory environment, generated in part by reactive oxygen species, in particular the strong oxidant hypochlorous acid (HOCl) produced in the neutrophil respiratory burst. HOCl effectively kills a broad range of pathogens but can also contribute to host tissue damage at sites of inflammation. To prevent tissue injury, HOCl is scavenged by human serum albumin (HSA) and other plasma proteins in interstitial fluids, leading to the formation of variously modified advanced oxidation products (AOPPs) with pro-inflammatory properties. Previously, we showed that HOCl-mediated N-chlorination converts HSA and other plasma proteins into efficient activators of the phagocyte respiratory burst, but the role of these AOPPs in antigen presentation by macrophages remained unclear. Here, we show that physiologically relevant amounts of N-chlorinated HSA can strongly impair the capacity of THP-1-derived macrophages to present antigens to antigen-specific T cells via MHC class II proteins at multiple stages. Initially, N-chlorinated HSA inhibits antigen internalization by converting antigens into scavenger receptor (SR) ligands and competing with the modified antigens for binding to SR CD36. Later steps of antigen presentation, such as intracellular antigen processing and MHC class II expression are negatively affected, as well. We propose that impaired processing of pathogens or exogenous antigens by immune cells at an initial stage of infection prevents antigen presentation in an environment potentially hostile to cells of the adaptive immune response, possibly shifting it towards locations removed from the actual insult, like the lymph nodes. On the flip side, excessive retardation or complete inhibition of antigen presentation by N-chlorinated plasma proteins could contribute to chronic infection and inflammation.","pmid":"33940547","doi":"10.1016/j.redox.2021.101981","url":"https://pubmed.ncbi.nlm.nih.gov/33940547/"},{"id":942,"title":"Mechanism of cyanocobalamin chlorination by hypochlorous acid.","authors":"Dereven'kov, Ilia A; Osokin, Vladimir S; Hannibal, Luciana; Makarov, Sergei V; Khodov, Ilya A; Koifman, Oskar I","year":2021,"date":"2021 Jun","journal":"Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCl) is a strong oxidant produced by myeloperoxidase. Previous work suggested that HOCl modifies the corrin ring of cobalamins to yield chlorinated species via mechanisms that are incompletely understood. Herein, we report a mechanistic study on the reaction between cyanocobalamin (CNCbl, vitamin B(12)) and HOCl. Under weakly acidic, neutral and weakly alkaline conditions, the reaction produces the c-lactone derivative of CNCbl chlorinated at the C10-position of corrin ring (C10-Cl-CNCbl-c-lactone). Formation of C10-Cl-CNCbl-c-lactone was not observed at pH ≥ 9.9. The chlorination of CNCbl by HOCl proceeds via two pathways involving one and two HOCl molecules: the reaction is initiated by the very fast formation of a complex between CNCbl and HOCl, which either undergoes slow transformation to chlorinated species, or rapidly reacts with a second HOCl molecule to produce C10-Cl-CNCbl. Subsequent reaction of C10-Cl-CNCbl with HOCl proceeds rapidly toward lactone ring formation by H-atom abstraction at position C8. This work uncovered mechanisms and products of the reaction of a biologically active and therapeutically used cobalamin, CNCbl and the endogenous oxidant HOCl. Binding and reactivity studies of C10-Cl-CNCbl and C10-Cl-CNCbl-c-lactone with relevant proteins of the cobalamin pathway and with cultured cells are necessary to elucidate the potential physiological effects of these species.","pmid":"33914169","doi":"10.1007/s00775-021-01869-5","url":"https://pubmed.ncbi.nlm.nih.gov/33914169/"},{"id":944,"title":"A novel ratiometric and colorimetric chemosensor for highly sensitive, selective and ultrafast tracing of HClO in live cells, bacteria and zebrafish.","authors":"Ding, Feng; Wen, Han; Zhuo, Ruijiang; Li, Jiawei; Zheng, Hui; Deng, Yuru; Shen, Jianliang; He, Xiaojun","year":2021,"date":"2021 May 29","journal":"Analytica chimica acta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HClO) along with its ionic form, hypochlorite anion (ClO(-)) are critical reactive oxygen species (ROS), which play vital roles in biological systems. Dysregulated production of HClO/ClO(-) can result in tissue damage and cause a variety of diseases. Besides, Sodium hypochlorite has been widely used as a bleaching agent for water disinfection, surface cleaning in daily life. Excessive exposure to sodium hypochlorite will lead to symptoms of severe breathing and skin problems. Therefore, developing a state-of-the-art (simple, highly sensitive, highly selective and super fast-response) sensor for tracking HClO is of biological, toxicological, and environmental importance. Though many HClO probes have been reported so far, this big aim still presents a challenge. Researchers around the world are continuing to develop new HClO probes that could improve their sensitivity, selectivity, the limit of detection, response time, easiness to use, etc. Herein, with coumarin as the fluorophore molecule, we rationally developed a novel chemosensor (CMTH) for detecting HClO with both ratiometric and colorimetric responses resulted from the oxidation reaction of CN bond. Further analysis results indicated that CMTH can realize highly sensitive with low limit of detection (256 nM, among the best of its kind) and highly selective (over a bunch of interfering analytes) imaging detection of HClO in multiple organisms with low cytotoxicity, and good cell and tissue permeability as well. In particular, compared to other fluorescent HClO probes reported so far, CMTH excels in the response time to HClO (< 40 s), being the top-notch of its kind. Besides, owing to its excellent water solubility, CMTH can also be applied to track HClO in the environmental system. Taken together, we have presented here a novel chemosensor, CMTH, as a colorimetric and ratiometric chemosensor for highly sensitive and ultrafast imaging detection of HClO in aqueous solutions, eukaryotic cells, prokaryotic bacteria and vertebrate zebrafish.","pmid":"33896562","doi":"10.1016/j.aca.2021.338472","url":"https://pubmed.ncbi.nlm.nih.gov/33896562/"},{"id":945,"title":"A Concept for the Reduction of Mucosal SARS-CoV-2 Load using Hypochloric Acid Solutions.","authors":"Mueller, Christian A; Winter, Michael; Renner, Bertold","year":2021,"date":"2021 Jul","journal":"Drug research","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"During the next few months or years, vaccination against SARS-CoV-2 infection will significantly reduce the morbidity and mortality of COVID-19. However, additional measures are needed to protect those who are still not immunized. This is even more important in view of new viral mutations that result in increased transmission rates. We propose that the use of long-standing medicinal solutions based on hypochloric acid (HOCl) and intended for application on wounds may be effective as a gargling solution or nasal irrigation in blocking transmission of the virus. Here, we propose the use of HOCl-containing solutions for blocking the transmission of SARS-CoV-2 in combination with other prevention measures. This may constitute another important cornerstone in the fight against the COVID-19 pandemic.","pmid":"33890267","doi":"10.1055/a-1467-5956","url":"https://pubmed.ncbi.nlm.nih.gov/33890267/"},{"id":946,"title":"Endolysin LysSTG2: Characterization and application to control Salmonella Typhimurium biofilm alone and in combination with slightly acidic hypochlorous water.","authors":"Zhang, Yu; Huang, Hung-Hsin; Duc, Hoang Minh; Masuda, Yoshimitsu; Honjoh, Ken-Ichi; Miyamoto, Takahisa","year":2021,"date":"2021 Sep","journal":"Food microbiology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The gene encoding LysSTG2, an endolysin from Salmonella-lytic bacteriophage STG2, was cloned, overexpressed, and characterized. LysSTG2 consists of a single domain belonging to the Peptidase_M15 superfamily. LysSTG2 showed strong lytic activity against chloroform-treated S. Typhimurium cells after incubation at 4-50 °C for 30 min, at pH ranging from 7.0 to 11.0, and in the presence of NaCl from 0 to 300 mmol/L. It also showed lytic activity against all the 14 tested Gram-negative strains treated with chloroform, including Salmonella, E. coli, and Pseudomonas aeruginosa, but not against the Gram-positive bacteria tested. In addition, LysSTG2 (100 μg/mL) reduced the viability of S. Typhimurium NBRC 12529 planktonic cells by 1.2 log and that of the biofilm cells after 1-h treatment. Sequential treatment of slightly acidic hypochlorous water (SAHW) containing 40 mg/L available chlorine and LysSTG2 (100 μg/mL) was effective on S. Typhimurium NBRC 12529 biofilm cells, removing more than 99% of biofilm cells. These results demonstrate that LysSTG2 alone can effectively kill S. Typhimurium cells after permeabilization treatment and successfully control S. Typhimurium in biofilms in combination with SAHW, suggesting that the combined use of LysSTG2 and SAHW might be a novel and promising method for combating S. Typhimurium in food industries.","pmid":"33875220","doi":"10.1016/j.fm.2021.103791","url":"https://pubmed.ncbi.nlm.nih.gov/33875220/"},{"id":956,"title":"Mycobacterium smegmatis Resists the Bactericidal Activity of Hypochlorous Acid Produced in Neutrophil Phagosomes.","authors":"Parker, Heather A; Dickerhof, Nina; Forrester, Lorna; Ryburn, Heath; Smyth, Leon; Messens, Joris; Aung, Htin L; Cook, Gregory M; Kettle, Anthony J; Hampton, Mark B","year":2021,"date":"2021 Apr 15","journal":"Journal of immunology (Baltimore, Md. : 1950)","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Neutrophils are often the major leukocyte at sites of mycobacterial infection, yet little is known about their ability to kill mycobacteria. In this study we have investigated whether the potent antibacterial oxidant hypochlorous acid (HOCl) contributes to killing of Mycobacterium smegmatis when this bacterium is phagocytosed by human neutrophils. We found that M. smegmatis were ingested by neutrophils into intracellular phagosomes but were killed slowly. We measured a t (1/2) of 30 min for the survival of M. smegmatis inside neutrophils, which is 5 times longer than that reported for Staphylococcus aureus and 15 times longer than Escherichia coli Live-cell imaging indicated that neutrophils generated HOCl in phagosomes containing M. smegmatis; however, inhibition of HOCl production did not alter the rate of bacterial killing. Also, the doses of HOCl that are likely to be produced inside phagosomes failed to kill isolated bacteria. Lethal doses of reagent HOCl caused oxidation of mycothiol, the main low-m.w. thiol in this bacterium. In contrast, phagocytosed M. smegmatis maintained their original level of reduced mycothiol. Collectively, these findings suggest that M. smegmatis can cope with the HOCl that is produced inside neutrophil phagosomes. A mycothiol-deficient mutant was killed by neutrophils at the same rate as wild-type bacteria, indicating that mycothiol itself is not the main driver of M. smegmatis resistance. Understanding how M. smegmatis avoids killing by phagosomal HOCl could provide new opportunities to sensitize pathogenic mycobacteria to destruction by the innate immune system.","pmid":"33753427","doi":"10.4049/jimmunol.2001084","url":"https://pubmed.ncbi.nlm.nih.gov/33753427/"},{"id":960,"title":"Evaluation of Decontamination Efficacy of Electrolytically Generated Hypochlorous Acid for the Vesicating Agent: A Multimodel Study.","authors":"Sharma, Ajay Kumar; Shukla, Sandeep Kumar; Kalonia, Aman; Shaw, Priyanka; Khanna, Kushagra; Yashavarddhan, M H; Gupta, Richa; Bhatnagar, Aseem","year":2022,"date":"2022","journal":"Current pharmaceutical biotechnology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"BACKGROUND: Sulfur Mustard is a strong vesicant and chemical warfare agent that imposes toxicity to the lungs, eyes, and skin after accidental or intended exposure. OBJECTIVES: The current study was intended to explore in vitro and in vivo decontamination properties of electrolytically generated HOCl (hypochlorous acid) against CEES (2-chloroethyle ethyle sulphide), a known sulfur mustard simulant & vesicating agent. METHODS: in vitro studies were carried out using UV spectroscopy and GC-MS methods. In vivo studies were performed in Strain A and immune-compromised mice by subcutaneous as well as prophylactic topical administration of HOCl pretreated CEES. The blister formation and mortality were considered as end-point. Histopathological study was conducted on skin samples by H & E method. DNA damage studies measuring γ-H2AX and ATM have been carried out in human blood using flow cytometry. Anti-bacterial action was tested by employing broth micro dilution methods. A comparative study was also carried out with known oxidizing agents. RESULTS: The topical application of pre-treated CEES at 5, 30 min and 1 h time points showed significant (p<0.001) inhibition of blister formation. DNA damage study showed reduced mean fluorescence intensity of DSBs nearly 17-20 times, suggesting that HOCl plays a protective role against DNA damage. Histopathology showed no sign of necrosis in the epidermis upto 5 min although moderate changes were observed at 30 min. Pretreated samples were analyzed for detection of reaction products with m/z value of 75.04, 69.08, 83.93, 85.95, 123.99, 126.00, and 108.97. HOCl showed a strong bactericidal effect at 40 ppm. The absorbance spectra of HOCl treated CEES showed lowered peaks in comparison to CEES alone and other oxidizing agents. CONCLUSION: In a nutshell, our results signify the decontamination role of HOCl for biological surface application.","pmid":"33719970","doi":"10.2174/1389201022666210311140922","url":"https://pubmed.ncbi.nlm.nih.gov/33719970/"},{"id":962,"title":"Virucidal activity of slightly acidic hypochlorous acid water toward influenza virus and coronavirus with tests simulating practical usage.","authors":"Miyaoka, Yu; Kabir, Md Humayun; Hasan, Md Amirul; Yamaguchi, Makiko; Shoham, Dany; Murakami, Harumi; Takehara, Kazuaki","year":2021,"date":"2021 May","journal":"Virus research","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Slightly acidic hypochlorous acid waters (SAHWs) with pH of 5.2-5.8 containing different concentrations of free available chlorine - 62, 119, 220, 300, and 540 ppm (SAHW-62, -119, -220, -300, and -540, respectively) - were evaluated for their virucidal activity toward a low pathogenic H7N1 avian influenza virus (AIV) and an infectious bronchitis virus (IBV) in suspension, abiotic carrier, and direct spray tests, with the presence of organic materials. In the carrier test, the dropping and wiping techniques were performed toward viruses on carriers. In the suspension test, SAHW-62 could decrease the viral titer of both AIV and IBV by more than 1000 times within 30 s. With the dropping technique, IBV on carriers showed high resistance to SAHW, while AIV on plastic carrier was inactivated to an effective level (≧3 log virus reduction) within 1 min. With the wiping technique, SAHW-62 could inactivate both AIV and IBV on wiped plastic carriers to an effective level within 30 s. However, SAHW-220 could not inactivate IBV in the wiping rayon sheet to an effective level. In the direct spray test, sprayed SAHW-300 within 10 min, and SAHW-540 within 20 min, inactivated AIV and IBV on the rayon sheets to undetectable level, respectively. Our study indicates that the usage of wipes with SAHW could remove viruses from plastic carriers, while viruses remained in the wipes. Besides, a small volume of sprayed SAHW was effective against the viruses on the rayon sheets for daily cleaning in the application area. The findings we obtained concerning IBV might basically be applicable in relation to SARS-CoV-2, given the resemblance between the two viruses.","pmid":"33705798","doi":"10.1016/j.virusres.2021.198383","url":"https://pubmed.ncbi.nlm.nih.gov/33705798/"},{"id":968,"title":"Prescribed exercise regimen versus usual care and hypochlorous acid wound solution versus placebo for treating venous leg ulcers: study protocol for a randomised controlled trial (Factorial4VLU).","authors":"Jull, Andrew; Wadham, Angela; Bullen, Chris; Parag, Varsha; Parsons, John G M; Laking, George; Waters, Jill; Klonizakis, Markos; O'Brien, Jane","year":2021,"date":"2021 Feb 18","journal":"BMJ open","category":"Human clinical & healthcare","evidence":"Clinical trial","relevance":"Medium","abstract":"INTRODUCTION: Compression is the mainstay of treatment for venous leg ulcers (VLUs) and there are few effective adjuvant treatments. There is only observational evidence supporting the use of hypochlorous acid (HOCl) as a topical wound solution on VLU and some limited randomised evidence for the effect of a prescribed regimen of exercise. METHODS AND ANALYSIS: The Factorial4VLU trial is a pragmatic, blinded, factorial randomised controlled trial, with 380 participants receiving either a prescribed exercise regimen compared with usual care and either active HOCl wound solution or placebo wound solution at each dressing change for up to 24 weeks. All participants will receive compression therapy. The primary outcome is the proportion of participants with healed VLU at 12 weeks after randomisation as adjudicated by blinded review of ulcer photographs. Secondary outcomes are proportion healed at 24 weeks, time to healing, estimated change in ulcer area, change in 2-Minute Walk Test, change in health-related quality of life, incidence of infection and incidence of all-cause adverse events. If either of the interventions shows a statistically significant positive difference on healing outcomes, cost-effectiveness will be modelled using a health service perspective. ETHICS AND DISSEMINATION: The Factorial4VLU trial received ethical approval from the Northern B Health and Disability Ethics Committee. We plan to publish the results within 1 year of trial completion and will include the results on the trial registration page. TRIAL REGISTRATION NUMBERS: Australia and New Zealand Clinical Trials Register (http://www.anzctr.org.au) (ACTRN12620000116921); Universal Trial Number (WHO) (U1111-1236-2997).","pmid":"33602710","doi":"10.1136/bmjopen-2020-043420","url":"https://pubmed.ncbi.nlm.nih.gov/33602710/"},{"id":972,"title":"A sprayable Acid-Oxidizing solution containing hypochlorous acid (AOS2020) efficiently and safely inactivates SARS-Cov-2: a new potential solution for upper respiratory tract hygiene.","authors":"Giarratana, Nadia; Rajan, Balan; Kamala, Kannan; Mendenhall, Michelle; Reiner, Giorgio","year":2021,"date":"2021 Aug","journal":"European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"INTRODUCTION: To eliminate the COVID-19 pandemic, the transmission of the virus SARS-CoV-2 among the population needs to be blocked and/or at least reduced. Upper respiratory tract viral loads are highest in the early stages of the disease, and high loads are associated with higher mortality rates. This study aims to evaluate the virucidal efficacy of AOS2020, a novel sprayable Acid-Oxidizing solution containing pure and stable hypochlorous acid (HClO), on human coronavirus SARS-Cov-2 in vitro, and the tolerability profile on nasal and oral mucosa suggesting to be a potential solution for upper respiratory hygiene. METHOD: Virucidal assays and intranasal and oral irritation tests were undertaken in accordance with relevant national and international guidance and methods. RESULTS: In pre-clinical tests, the AOS2020, showed > 99.8% virucidal efficacy in < 1 min against SARS-Cov-2. The safety profile testing on both the nasal and oral mucosa indicates that AOS2020 is non-irritant. CONCLUSION: These initial results indicate that this product has the potential treatment to reduce viral load in the upper respiratory tract.","pmid":"33575830","doi":"10.1007/s00405-021-06644-5","url":"https://pubmed.ncbi.nlm.nih.gov/33575830/"},{"id":975,"title":"The Responses of Bioactive Betanin Pigment and Its Derivatives from a Red Beetroot (Beta vulgaris L.) Betalain-Rich Extract to Hypochlorous Acid.","authors":"Starzak, Karolina; Sutor, Katarzyna; Świergosz, Tomasz; Nemzer, Boris; Pietrzkowski, Zbigniew; Popenda, Łukasz; Liu, Shi-Rong; Wu, Shu-Pao; Wybraniec, Sławomir","year":2021,"date":"2021 Jan 25","journal":"International journal of molecular sciences","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Neutrophils produce hypochlorous acid (HOCl) as well as other reactive oxygen species as part of a natural innate immune response in the human body; however, excessive levels of HOCl can ultimately be detrimental to health. Recent reports suggest that betacyanin plant pigments can act as potent scavengers of inflammatory factors and are notably effective against HOCl. Comparison of the in vitro anti-hypochlorite activities of a novel betalain-rich red beetroot (Beta vulgaris L.) extract with its pure betalainic pigments revealed that the extract had the highest anti-hypochlorite activity, far exceeding the activity of all of the betalainic derivatives and selected reference antioxidants. This suggests that it may be an important food-based candidate for management of inflammatory conditions induced by excessive HOCl production. Among all pigments studied, betanidin exhibited the highest activity across the pH range.","pmid":"33503808","doi":"10.3390/ijms22031155","url":"https://pubmed.ncbi.nlm.nih.gov/33503808/"},{"id":976,"title":"Actinidia arguta Pulp: Phytochemical Composition, Radical Scavenging Activity, and in Vitro Cells Effects.","authors":"Pinto, Diana; Sut, Stefania; Dall'Acqua, Stefano; Delerue-Matos, Cristina; Rodrigues, Francisca","year":2021,"date":"2021 Mar","journal":"Chemistry & biodiversity","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hardy kiwifruit (Actinidia arguta) is a highly appreciated exotic fruit endowed with outstanding bioactive compounds. The present work proposes to characterize the pulp from A. arguta organic fruits, emphasizing its radicals scavenging capacity and effects on intestinal cells (Caco-2 and HT29-MTX). The physicochemical properties and phenolic profile were also screened. The total phenolic and flavonoid contents (TPC and TFC, respectively) of pulp were 12.21 mg GAE/g on dry weight (DW) and 5.92 mg CE/g DW, respectively. A high antioxidant activity was observed (FRAP: 151.41 μmol FSE/g DW; DPPH: 12.17 mg TE/g DW). Furthermore, the pulp did not induce a toxic effect on Caco-2 and HT29-MTX cells viability up to 1000 μg/mL. Regarding in vitro scavenging capacity, the pulp revealed the highest scavenging power against NO(.) (IC(50) =3.45 μg/mL) and HOCl (IC(50) =12.77 μg/mL). These results emphasize the richness of A. arguta fruit pulp to be used in different food products.","pmid":"33491874","doi":"10.1002/cbdv.202000925","url":"https://pubmed.ncbi.nlm.nih.gov/33491874/"},{"id":978,"title":"Hypochlorite-induced aggregation of fibrinogen underlies a novel antioxidant role in blood plasma.","authors":"Mañucat-Tan, Noralyn; Zeineddine Abdallah, Rafaa; Kaur, Harsimran; Saviane, Daniel; Wilson, Mark R; Wyatt, Amy R","year":2021,"date":"2021 Apr","journal":"Redox biology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Fibrinogen, a major constituent of blood plasma, is highly susceptible to reaction with biological oxidants. It has been proposed that fibrinogen plays a role in antioxidant defence, but oxidation of fibrinogen is also known to disrupt normal blood clotting and is implicated in the pathology of atherosclerosis. In the present study, we show that the biological oxidant hypochlorite promotes the formation of soluble high molecular weight fibrinogen assemblies ≥40 × 10(6) Da, that do not accumulate when fibrinogen is induced to aggregate by other stresses such as heating or hydroxyl-mediated damage in vitro. Hypochlorite-modified fibrinogen is stable at 37 °C as assessed by precipitation assays, and has reduced susceptibility to iron-induced (hydroxyl-mediated) precipitation compared to native fibrinogen. In contrast to hypochlorite-modified albumin, which is known to be immunostimulatory, hypochlorite-modified fibrinogen does not induce RAW 264.7 (macrophage-like) cells or EOC 13.31 (microglia-like) cells to produce reactive oxygen species or induce cell death. Furthermore, depletion of fibrinogen from human blood plasma increases the immunostimulatory property of blood plasma after it is supplemented with hypochlorite in situ. We propose that reaction of hypochlorite with fibrinogen in blood plasma potentially reduces the accumulation of other hypochlorite-modified species such as immunostimulatory hypochlorite-modified albumin. The latter represent a novel role for fibrinogen in blood plasma antioxidant defence.","pmid":"33440293","doi":"10.1016/j.redox.2020.101847","url":"https://pubmed.ncbi.nlm.nih.gov/33440293/"},{"id":980,"title":"An Integrated HOCl-Producing E-Scaffold Is Active against Monomicrobial and Polymicrobial Biofilms.","authors":"Flurin, Laure; Raval, Yash S; Mohamed, Abdelrhman; Greenwood-Quaintance, Kerryl E; Cano, Edison J; Beyenal, Haluk; Patel, Robin","year":2021,"date":"2021 Feb 17","journal":"Antimicrobial agents and chemotherapy","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Oxidizing agents like hypochlorous acid (HOCl) have antimicrobial activity. We developed an integrated electrochemical scaffold, or e-scaffold, that delivers a continuous low dose of HOCl aimed at targeting microbial biofilms without exceeding concentrations toxic to humans as a prototype of a device being developed to treat wound infections in humans. In this work, we tested the device against 33 isolates of bacteria (including isolates with acquired antibiotic resistance) grown as in vitro biofilms alongside 12 combinations of dual-species in vitro biofilms. Biofilms were grown on the bottoms of 12-well plates for 24 h. An integrated e-scaffold was placed atop each biofilm and polarized at 1.5 V for 1, 2, or 4 h. HOCl was produced electrochemically by oxidizing chloride ions (Cl(-)) in solution to chlorine (Cl(2)); dissolved Cl(2) spontaneously dissociates in water to produce HOCl. The cumulative concentration of HOCl produced at the working electrode in each well was estimated to be 7.89, 13.46, and 29.50 mM after 1, 2, and 4 h of polarization, respectively. Four hours of polarization caused an average reduction of 6.13 log(10) CFU/cm(2) (±1.99 log(10) CFU/cm(2)) of viable cell counts of monospecies biofilms and 5.53 log(10) CFU/cm(2) (±2.31 log(10) CFU/cm(2)) for the 12 dual-species biofilms studied. The described integrated e-scaffold reduces viable bacterial cell counts in biofilms formed by an array of antibiotic-susceptible and -resistant bacteria alone and in combination.","pmid":"33397650","doi":"10.1128/AAC.02007-20","url":"https://pubmed.ncbi.nlm.nih.gov/33397650/"},{"id":982,"title":"A Multiple-Hit Hypothesis Involving Reactive Oxygen Species and Myeloperoxidase Explains Clinical Deterioration and Fatality in COVID-19.","authors":"Goud, Pravin T; Bai, David; Abu-Soud, Husam M","year":2021,"date":"2021","journal":"International journal of biological sciences","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"Multi-system involvement and rapid clinical deterioration are hallmarks of coronavirus disease 2019 (COVID-19) related mortality. The unique clinical phenomena in severe COVID-19 can be perplexing, and they include disproportionately severe hypoxemia relative to lung alveolar-parenchymal pathology and rapid clinical deterioration, with poor response to O(2) supplementation, despite preserved lung mechanics. Factors such as microvascular injury, thromboembolism, pulmonary hypertension, and alteration in hemoglobin structure and function could play important roles. Overwhelming immune response associated with \"cytokine storms\" could activate reactive oxygen species (ROS), which may result in consumption of nitric oxide (NO), a critical vasodilation regulator. In other inflammatory infections, activated neutrophils are known to release myeloperoxidase (MPO) in a natural immune response, which contributes to production of hypochlorous acid (HOCl). However, during overwhelming inflammation, HOCl competes with O(2) at heme binding sites, decreasing O(2) saturation. Moreover, HOCl contributes to several oxidative reactions, including hemoglobin-heme iron oxidation, heme destruction, and subsequent release of free iron, which mediates toxic tissue injury through additional generation of ROS and NO consumption. Connecting these reactions in a multi-hit model can explain generalized tissue damage, vasoconstriction, severe hypoxia, and precipitous clinical deterioration in critically ill COVID-19 patients. Understanding these mechanisms is critical to develop therapeutic strategies to combat COVID-19.","pmid":"33390833","doi":"10.7150/ijbs.51811","url":"https://pubmed.ncbi.nlm.nih.gov/33390833/"},{"id":986,"title":"A lysosome-targetable two-photon excited near-infrared fluorescent probe for visualizing hypochlorous acid-involved arthritis and its treatment.","authors":"Mao, Guo-Jiang; Wang, Ying-Ying; Dong, Wen-Pei; Meng, Hong-Min; Wang, Qian-Qian; Luo, Xiao-Feng; Li, Yao; Zhang, Guisheng","year":2021,"date":"2021 Mar 15","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"Lysosome of phagocyte is the main site of hypochlorous acid (HClO) production, and HClO can be employed as the biomarker for the diagnosis and treatment evaluation of arthritis. In recent years, developing fluorescent probes for lysosomal HClO has attracted considerable attention, but most of them still have some defects, such as autofluorescence, phototoxicity and photobleaching because of their excitation and emission located in short-wavelength region. Due to the advantages of two-photon fluorescent probes with near-infrared emissions, a lysosome-targetable two-photon fluorescent probe (Lyso-TP-HClO) with a near-infrared emission was reported in this paper. Lyso-TP-HClO has a high selectivity and a high sensitivity to HClO in the linear range (10.0 × 10(-8) to 5.0 × 10(-6) M), with a detection limit of 3.0 × 10(-8) M. Due to the two-photon excited near-infrared emission, Lyso-TP-HClO has excellent imaging performances, such as small autofluorescence, excellent photostability, and large imaging depth. Furthermore, Lyso-TP-HClO was successfully employed for visualizing lysosomal HClO in bacteria-infected cells. At last, we have successfully used Lyso-TP-HClO to image the arthritis and evaluate the treatment of arthritis in mice. All the results confirm that Lyso-TP-HClO is a useful chemical tool for imaging of lysosomal HClO, the diagnosis of arthritis, and treatment evaluation of arthritis.","pmid":"33360565","doi":"10.1016/j.saa.2020.119326","url":"https://pubmed.ncbi.nlm.nih.gov/33360565/"},{"id":993,"title":"Distinct effects of hypochlorite types on the reduction of antibiotic resistance genes during waste activated sludge fermentation: Insights of bacterial community, cellular activity, and genetic expression.","authors":"Luo, Jingyang; Huang, Wenxuan; Zhang, Qin; Wu, Yang; Fang, Fang; Cao, Jiashun; Su, Yinglong","year":2021,"date":"2021 Feb 5","journal":"Journal of hazardous materials","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The effectiveness of hypochlorites (NaClO and Ca(ClO)(2)) on the reduction of antibiotic resistance genes (ARGs) during waste activated sludge (WAS) fermentation was determined by the quantitative PCR. NaClO and Ca(ClO)(2) exhibited distinct effects on ARGs fates. Ca(ClO)(2) was effective in removing all investigated ARGs, and the efficiency was highly dose-dependent. Unexpectedly, the NaClO treatment attenuated ARGs with lower efficiency and even caused the propagation of certain ARGs (i.e., aadA1 and tetQ) at higher doses. The extracellular polymeric substances dissolution and membrane integrity suggested that unstable NaClO had acute effects on bacteria initially, while it was ineffective to further attenuate ARGs released from hosts due to the rapid consumption of oxidative ClO(-). Without lasting and strong oxidative stress, the microbial activities of tolerant ARGs hosts will partially recover and then contribute to the ARGs dissemination across genera. In contrast, solid-state Ca(ClO)(2) was slowly released and exhibited prolonged effects on bacteria by disrupting cell membranes and removing the susceptible ARGs released from hosts. Furthermore, bacterial taxa-ARG network analysis indicated that Ca(ClO)(2) reduced the abundance of potential hosts, and the metabolic pathway and gene expression related to ARGs propagation were significantly downregulated by Ca(ClO)(2), which contributed to efficient ARGs attenuation.","pmid":"33265039","doi":"10.1016/j.jhazmat.2020.124010","url":"https://pubmed.ncbi.nlm.nih.gov/33265039/"},{"id":994,"title":"Role of Carbonate Species on General Acid Catalysis of Bromide Oxidation by Hypochlorous Acid (HOCl) and Oxidation by Molecular Chlorine (Cl(2)).","authors":"Brodfuehrer, Samuel H; Wahman, David G; Alsulaili, Abdalrahman; Speitel, Gerald E Jr; Katz, Lynn E","year":2020,"date":"2020 Dec 15","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Kinetic models for disinfectant decay and disinfection byproduct (DBP) formation are necessary for predicting water quality from the treatment plant to the tap. A kinetic model for conditions relevant to chloramine disinfection of drinking water (pH 6-9 and carbonate-buffered) was developed to simulate incomplete bromide (Br(-)) oxidation during short prechlorination periods because it is the first step in a complex system of reactions that leads to disinfectant loss and DBP formation. Hypochlorous acid (HOCl + Br- → kHOClHOBr + Cl-) and molecular chlorine (Cl2 + Br- + H2O → kCl2HOBr + 2Cl- + H+) were the free chlorine species relevant to Br(-) oxidation, and Cl(2) hydrolysis and formation reactions (Cl2 + H2O + A- ⇌ k-4k4HOCl + HA + Cl-) were necessary to accurately simulate Cl(2) concentrations instead of assuming equilibrium. Previous work has shown that Br(-) oxidation by HOCl and Cl(2) formation are acid-catalyzed and Cl(2) hydrolysis is base-catalyzed, but the impact of carbonate species had not been studied. This work showed that the carbonate species have an enhanced catalytic impact with rate constants up to 1000 times larger than would be estimated by the Brønsted relationship for similar acids, which causes the oxidation by HOCl rate constant (k(HOCl)) to nearly double and oxidation by Cl(2) to occur above pH 7 in high-alkalinity waters.","pmid":"33263389","doi":"10.1021/acs.est.0c04563","url":"https://pubmed.ncbi.nlm.nih.gov/33263389/"},{"id":995,"title":"Comparison of Skin Antiseptic Agents and the Role of 0.01% Hypochlorous Acid.","authors":"Tran, Ann Q; Topilow, Nicole; Rong, Andrew; Persad, Patrice J; Lee, Michael C; Lee, James H; Anagnostopoulos, Apostolos G; Lee, Wendy W","year":2021,"date":"2021 Sep 14","journal":"Aesthetic surgery journal","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: Hypochlorous acid (HA) has both anti-microbial and wound-healing properties with a growing role for utilization in pre-procedural care on the face. OBJECTIVES: The authors sought to compare the antiseptic property of 0.01% HA solution, 5% povidone iodine (PI), 4% chlorhexidine gluconate (CHG), and 70% isopropyl alcohol (IPA) antiseptic on facial skin. METHODS: This was a prospective single-center clinical trial. RESULTS: A total of 21 participants were recruited. Bacterial growth was seen in CHG (10%), IPA (71%), PI (81%), and HA (95%) of specimens (P < 0.001). CHG had less growth compared with HA (P = <0.001), IPA (P = <0.001), and PI (P = <0.001). No difference in bacterial growth was noted between HA and IPA (P = 0.063) or HA and PI (P = 0.25). Significant differences in mono-microbial and poly-microbial growth were seen between HA and IPA (P = 0.046) and HA and CHG (P = <0.001). Staphylococcus epidermidis grew less frequently in CHG (10%), followed by IPA (29%), PI (71%), and HA (71%). Staphylococcus capitis grew less frequently in CHG (0%), followed by PI (14%), HA (24%), and IPA (29%). CONCLUSIONS: CHG reduced the bacterial growth compared with HA, PI, and IPA. However, HA, PI, and IPA had insignificant differences in bactericidal effects. Our study provides a supporting role of HA to be considered as an antiseptic.","pmid":"33247899","doi":"10.1093/asj/sjaa322","url":"https://pubmed.ncbi.nlm.nih.gov/33247899/"},{"id":1002,"title":"Kinetics of Bacterial Inactivation by Peroxynitric Acid in the Presence of Organic Contaminants.","authors":"Yokoyama, Takashi; Miyazaki, Shinya; Akagi, Hiroko; Ikawa, Satoshi; Kitano, Katsuhisa","year":2021,"date":"2021 Jan 4","journal":"Applied and environmental microbiology","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Low-temperature atmospheric-pressure plasma has been studied for disinfection purposes. When plasma is exposed to water, reactive oxygen and nitrogen species are generated and preserved in the water fraction (plasma-treated water [PTW]), which consequently exhibits bactericidal activity. At low temperatures, one of the bactericidal components of PTW is peroxynitric acid (PNA). Importantly, PNA can also be synthesized by chemical reaction, without exposure to plasma. In this study, we evaluated the bactericidal properties of PNA based on reaction kinetics in comparison with other disinfectants. The analysis, based on dose-dependent effects, showed that PNA exhibited about 1 and 10 times the bactericidal activity of hypochlorous acid (HOCl) and peracetic acid, respectively. In addition, we evaluated the influence of organic contaminants on the bactericidal effects of PNA and HOCl. The bactericidal potential of both disinfectants was reduced by bovine serum albumin (BSA); however, PNA showed about 30-times-higher resistance against BSA inhibition than HOCl. Analysis of the dose-dependent effects of PNA revealed that the inhibition of bactericidal effect was caused by its consumption. Further experiments using model substrates containing particular amino acid residues (Met, Cys, Lys, and Leu) suggested that the bacterial inactivation by PNA is less affected by BSA due to the low reactivity and narrow reactivity spectrum of PNA for amino acid residues. Overall, our results suggest that PNA has a great disinfection potential, especially in the presence of organic contaminants (e.g., on the surface of the human body and on medical instruments contaminated with biological fluids).IMPORTANCE A good disinfectant for the human body should have various properties, such as strong bactericidal activity, harmlessness to living tissues, and resistance against biological fluids (or other organic contaminants). Peroxynitric acid (PNA) showed a bactericidal effect that was several tens up to several hundred times higher per unit of molarity than that of sodium hypochlorite and peracetic acid, which are used as general disinfectants for medical equipment. Moreover, the high resistance of PNA to organic load was confirmed, indicating that PNA will inactivate bacteria effectively even on contaminated surfaces, such as used medical devices or the human body surface. Therefore, we propose that PNA can be used as a strong disinfectant for the human body.","pmid":"33127816","doi":"10.1128/AEM.01860-20","url":"https://pubmed.ncbi.nlm.nih.gov/33127816/"},{"id":1007,"title":"HClO-Activated Fluorescence and Photosensitization from an AIE Nanoprobe for Image-Guided Bacterial Ablation in Phagocytes.","authors":"Wu, Min; Wu, Wenbo; Duan, Yukun; Liu, Xingang; Wang, Meng; Phan, Chi Uyen; Qi, Guobin; Tang, Guping; Liu, Bin","year":2020,"date":"2020 Nov","journal":"Advanced materials (Deerfield Beach, Fla.)","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Bacteria hiding in host phagocytes are difficult to kill, which can cause phagocyte disorders resulting in local and systemic tissue damage. Effective accumulation of activatable photosensitizers (PSs) in phagocytes to realize selective imaging and on-demand photodynamic ablation of bacteria is of great scientific and practical interests for precise bacteria diagnosis and treatment. Herein, HClO-activatable theranostic nanoprobes, DTF-FFP NPs, for image-guided bacterial ablation in phagocytes are introduced. DTF-FFP NPs are prepared by nanoprecipitation of an HClO-responsive near-infrared molecule FFP and an efficient PS DTF with aggregation-induced emission characteristic using an amphiphilic polymer Pluronic F127 as the encapsulation matrix. As an energy acceptor, FFP can quench both fluorescence and production of reactive oxygen species (ROS) of DTF, thus eliminating the phototoxicity of DTF-FFP NPs in normal cells and tissues. Once delivered to the infection sites, DTF-FFP NPs light up with red fluorescence and efficiently generate ROS owing to the degradation of FFP by the stimulated release of HClO in phagocytes. The selective activation of fluorescence and photosensitization is successfully confirmed by both in vitro and in vivo results, demonstrating the effectiveness and theranostic potential of DTF-FFP NPs in precise bacterial therapy.","pmid":"33079417","doi":"10.1002/adma.202005222","url":"https://pubmed.ncbi.nlm.nih.gov/33079417/"},{"id":1009,"title":"Toxicological aspects of increased use of surface and hand disinfectants in Croatia during the COVID-19 pandemic: a preliminary report.","authors":"Babić, Željka; Turk, Rajka; Macan, Jelena","year":2020,"date":"2020 Sep 1","journal":"Arhiv za higijenu rada i toksikologiju","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"All COVID-19 prevention strategies include regular use of surface disinfectants and hand sanitisers. As these measures took hold in Croatia, the Croatian Poison Control Centre started receiving phone calls from the general public and healthcare workers, which prompted us to investigate whether the risk of suspected/symptomatic poisonings with disinfectants and sanitisers really increased. To that end we compared their frequency and characteristics in the first half of 2019 and 2020. Cases of exposures to disinfectants doubled in the first half of 2020 (41 vs 21 cases in 2019), and exposure to sanitisers increased about nine times (46 vs 5 cases in 2019). In 2020, the most common ingredients of disinfectants and sanitisers involved in poisoning incidents were hypochlorite/glutaraldehyde, and ethanol/isopropyl alcohol, respectively. Exposures to disinfectants were recorded mostly in adults (56 %) as accidental (78 %) through ingestion or inhalation (86 %). Fortunately, most callers were asymptomatic (people called for advice because they were concerned), but nearly half reported mild gastrointestinal or respiratory irritation, and in one case severe symptoms were reported (gastrointestinal corrosive injury). Reports of exposure to hand sanitisers highlighted preschool children as the most vulnerable group. Accidental exposure through ingestion dominated, but, again, only mild symptoms (gastrointestinal or eye irritation) developed in one third of the cases. These preliminary findings, however limited, confirm that increased availability and use of disinfectants and sanitisers significantly increased the risk of poisoning, particularly in preschool children through accidental ingestion of hand sanitisers. We therefore believe that epidemiological recommendations for COVID-19 prevention should include warnings informing the general public of the risks of poisoning with surface and hand disinfectants in particular.","pmid":"33074170","doi":"10.2478/aiht-2020-71-3470","url":"https://pubmed.ncbi.nlm.nih.gov/33074170/"},{"id":1011,"title":"In-office bleaching with low/medium vs. high concentrate hydrogen peroxide: A systematic review and meta-analysis.","authors":"Maran, Bianca Medeiros; Matos, Thalita de Paris; de Castro, Andrea Dos Santos; Vochikovski, Laína; Amadori, Ana Luiza; Loguercio, Alessandro D; Reis, Alessandra; Berger, Sandrine Bittencourt","year":2020,"date":"2020 Dec","journal":"Journal of dentistry","category":"Food & agriculture","evidence":"Systematic review / meta-analysis","relevance":"High","abstract":"OBJECTIVE: To answer the following research question: \"Dolow/medium hydrogen peroxide (HP) concentrations used for in-office bleaching in patients with permanent dentition have similar color change and bleaching sensitivity (BS) to high HP concentrations?\" DATA: Randomized controlled trials that compared low/medium vs. high concentrate HP were included. The risk of bias (RoB) was evaluated using the Cochrane Collaboration tool. Meta-analyses were conducted for color change (ΔE*ab, ΔSGU/SGU), risk, and intensity of BS, using the random-effects model. Heterogeneity was assessed with the Cochrane Q test, I(2) statistics, and prediction interval. The GRADE assessed the certainty of the evidence. SOURCES: Search was performed in PubMed, Cochrane Library, BBO, LILACS, Scopus, Web of Science and grey literature on 15th September 2018 (updated on 13th May 2020). STUDY SELECTION: 25 studies remained. Five were at low RoB; thirteen were at unclear RoB, and seven were at high RoB. The risk of having BS was, on average, 33 % lower (RR = 0.67; 95 % CI 0.51 to 0.86) for low/medium concentrate HP than high HP. No significant difference in color change was detected among groups, except from the subgroup low vs. high HP for the immediate color change, but this difference is not clinically relevant. The certainty of evidence for color change was low and very low, and moderate for the BS. CONCLUSIONS: Low and medium hydrogen peroxide concentrate products for in-office bleaching have lower risk and intensity of bleaching sensitivity than the high concentrate hydrogen peroxide group, with no difference in color change efficacy. CLINICAL SIGNIFICANCE: The use of low concentrate hydrogen peroxide products may produce the same color change efficacy with the bonus of having lower risk and intensity of bleaching sensitivity. However, the ideal concentration at which this occurs is yet unknown and deserves further investigations. No funding. PROSPERO CRD42018108266.","pmid":"33068711","doi":"10.1016/j.jdent.2020.103499","url":"https://pubmed.ncbi.nlm.nih.gov/33068711/"},{"id":1016,"title":"Decomposition performance of hypochlorite on bead-type NiO(x)(OH)(y) catalyst: improving applicability of catalysts.","authors":"Xu, Wenying; Gao, Haoyang","year":2020,"date":"2020 Sep","journal":"Water science and technology : a journal of the International Association on Water Pollution Research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"An easy-to-use, pollution-free and reusable beaded NiO(x)(OH)(y) catalyst for improving hypochlorite oxidation was prepared by impregnating the mixture of persulfate and alkali over alumina and then reduced it with Ni(2+). The effects of catalyst preparation conditions and reaction parameters on NaClO conversion rate and Ni(2+) dissolution rate were studied. Impregnating the γ-Al(2)O(3) beads in PS/OH(-) mixed solution with 0.59 M PS and PS/OH(-) molar ratio of 1.1, and then reducing with 0.8 M Ni(2+) solution is the best condition for preparing catalyst. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The best catalytic layer is characterized by high content of chemisorbed oxygen which can be converted into atomic oxygen. The hypochlorite conversion rate increased with the catalyst dosage and reuse times, and decreased with available chlorine, while pH of hypochlorite solution had little effect on the conversion rate. After running stably for 120 h in continuous flow test, the chemisorbed oxygen content in the optimal catalytic layer decreased slightly. Atomic oxygen plays an important role in the decolorization of dye solution by NaClO/NiO(x)(OH)(y) system. The oxidant consumption cost of this process is much cheaper than Fenton reagent. The prepared catalyst has great potential in hypochlorite decomposition and wastewater treatment.","pmid":"33031074","doi":"10.2166/wst.2020.402","url":"https://pubmed.ncbi.nlm.nih.gov/33031074/"},{"id":1019,"title":"Redox regulation in host-pathogen interactions: thiol switches and beyond.","authors":"Varatnitskaya, Marharyta; Degrossoli, Adriana; Leichert, Lars I","year":2021,"date":"2021 Feb 23","journal":"Biological chemistry","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"Our organism is exposed to pathogens on a daily basis. Owing to this age-old interaction, both pathogen and host evolved strategies to cope with these encounters. Here, we focus on the consequences of the direct encounter of cells of the innate immune system with bacteria. First, we will discuss the bacterial strategies to counteract powerful reactive species. Our emphasis lies on the effects of hypochlorous acid (HOCl), arguably the most powerful oxidant produced inside the phagolysosome of professional phagocytes. We will highlight individual examples of proteins in gram-negative bacteria activated by HOCl via thiol-disulfide switches, methionine sulfoxidation, and N-chlorination of basic amino acid side chains. Second, we will discuss the effects of HOCl on proteins of the host. Recent studies have shown that both host and bacteria address failing protein homeostasis by activation of chaperone-like holdases through N-chlorination. After discussing the role of individual proteins in the HOCl-defense, we will turn our attention to the examination of effects on host and pathogen on a systemic level. Recent studies using genetically encoded redox probes and redox proteomics highlight differences in redox homeostasis in host and pathogen and give first hints at potential cellular HOCl signaling beyond thiol-disulfide switch mechanisms.","pmid":"33021957","doi":"10.1515/hsz-2020-0264","url":"https://pubmed.ncbi.nlm.nih.gov/33021957/"},{"id":1020,"title":"Post-amputation wound on diabetic foot.","authors":"Cuzic, Domagoj; Lenkovic, Maya","year":2020,"date":"2020 Oct 1","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"","pmid":"33016850","doi":"10.12968/jowc.2020.29.Sup10a.S10","url":"https://pubmed.ncbi.nlm.nih.gov/33016850/"},{"id":1021,"title":"Non-healing surgical wound with exposed bone.","authors":"Dissemond, Joachim","year":2020,"date":"2020 Oct 1","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"","pmid":"33016848","doi":"10.12968/jowc.2020.29.Sup10a.S11","url":"https://pubmed.ncbi.nlm.nih.gov/33016848/"},{"id":1022,"title":"Wound cleansing: benefits of hypochlorous acid.","authors":"Joachim, Dissemond","year":2020,"date":"2020 Oct 1","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Cleansing provides an opportunity to remove pathogens from the wound bed, thereby preventing an increase in the bioburden and delayed healing. This article describes the reported efficacy of hypochlorous acid-containing wound cleansers.","pmid":"33016847","doi":"10.12968/jowc.2020.29.Sup10a.S4","url":"https://pubmed.ncbi.nlm.nih.gov/33016847/"},{"id":1023,"title":"Dehisced surgical wound.","authors":"Younis, Ibby","year":2020,"date":"2020 Oct 1","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"","pmid":"33016846","doi":"10.12968/jowc.2020.29.Sup10a.S18","url":"https://pubmed.ncbi.nlm.nih.gov/33016846/"},{"id":1024,"title":"Diabetic foot ulcer.","authors":"Kurz, Peter","year":2020,"date":"2020 Oct 1","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"","pmid":"33016845","doi":"10.12968/jowc.2020.29.Sup10a.S17","url":"https://pubmed.ncbi.nlm.nih.gov/33016845/"},{"id":1025,"title":"Necrotising fasciitis.","authors":"Kurz, Peter","year":2020,"date":"2020 Oct 1","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"","pmid":"33016844","doi":"10.12968/jowc.2020.29.Sup10a.S14","url":"https://pubmed.ncbi.nlm.nih.gov/33016844/"},{"id":1027,"title":"Granudacyn Wound Irrigation Solution and Wound Gel.","authors":"","year":2020,"date":"2020 Oct 1","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"","pmid":"33016842","doi":"10.12968/jowc.2020.29.Sup10a.S9","url":"https://pubmed.ncbi.nlm.nih.gov/33016842/"},{"id":1028,"title":"Infected cardiac pacemaker pocket.","authors":"Oberhoffer, Martin","year":2020,"date":"2020 Oct 1","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"","pmid":"33016841","doi":"10.12968/jowc.2020.29.Sup10a.S13","url":"https://pubmed.ncbi.nlm.nih.gov/33016841/"},{"id":1031,"title":"Development of a personal passive air sampler for estimating exposure to effective chlorine while using chlorine-based disinfectants.","authors":"Ha, Yeonjeong; Kim, Yoonsub; Song, Eugene; Yoo, Hyun Jung; Kwon, Jung-Hwan","year":2021,"date":"2021 Mar","journal":"Indoor air","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"With an increasing use of indoor disinfectants such as chlorine (Cl(2) ) and hypochlorous acid, a convenient sampler for estimating exposure to oxidants, such as effective chlorine, is necessary. Here, we developed a personal passive air sampler (PPAS) composed of a redox dye, o-dianisidine, in a polydimethylsiloxane (PDMS) sheet. o-Dianisidine readily reacts with gaseous oxidants generated by bleach usage, and its color changes as the reaction progresses; hence, personal exposure to effective chlorine could be easily detected by the naked eye, while cumulative exposure could be determined by measuring concentrations of o-dianisidine reacting with it. The PPAS was calibrated, and a sampling rate of 0.00253 m(3) /h was obtained using a small test chamber. The PPAS was tested with the help of ten volunteers whose personal exposure to Cl(2) -equivalent gas was estimated after bathrooms were cleaned using spray and liquid-type household disinfection products, and the accumulated exposure-gas concentrations ranged from 69 to 408 ppbv and 148 to 435 ppbv, respectively. These PPAS-derived exposure concentrations were approximately two orders lower than those estimated using ConsExpo, suggesting a significant overestimation by prevailing screening models, possibly due to the ignorance of transformation reactions.","pmid":"32978992","doi":"10.1111/ina.12747","url":"https://pubmed.ncbi.nlm.nih.gov/32978992/"},{"id":1032,"title":"COVID-19 prophylaxis in ophthalmology.","authors":"Finger, Paul T; Fam, Anthony; Tomar, Ankit S; Garg, Gaurav; Chin, Kimberly J","year":2020,"date":"2020 Oct","journal":"Indian journal of ophthalmology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"","pmid":"32971608","doi":"10.4103/ijo.IJO_2459_20","url":"https://pubmed.ncbi.nlm.nih.gov/32971608/"},{"id":1035,"title":"Hypochlorous acid water prevents postoperative intrauterine infection after microwave endometrial ablation.","authors":"Tsuda, Akira; Kanaoka, Yasushi","year":2020,"date":"2020 Nov","journal":"The journal of obstetrics and gynaecology research","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"AIM: We investigated the effects of uterine cavity lavage using hypochlorous acid water (HClO) on preventing postoperative intrauterine infection after microwave endometrial ablation (MEA). METHODS: Four hundred and eleven consecutive patients were enrolled in this study. The patients were divided into two groups: 214 cases in 2014-2016 with disinfection using povidone-iodine antiseptic solution alone (group A) and 197 cases in 2017-2019 with additional intrauterine douche using HClO (group B). HClO was used at a concentration of 200 ppm of residual chlorine. One gram of Ceftriaxone Sodium Hydrate was administered by drip infusion during MEA in both groups. Oral antibiotics were administered after MEA only in group A but not in group B. RESULTS: Mean patient age (mean ± SD; years old) was 44.5 ± 4.6 in group A and 44.8 ± 5.4 in group B, and mean operation time (min) was 30.4 ± 19.1 in group A and 34.4 ± 22.6 in group B, respectively. Neither were significantly different between groups. The combined ablation techniques i.e. transcervical microwave myolysis and transcervical microwave adenomyolysis did not increase frequency of infection. Postoperative intrauterine infection cases in group B (8 cases) were significantly lower than those in group A (28 cases) (Chi-square test, P = 0.001). Hysterectomy was performed in three severe intrauterine infection cases in group A, but no cases of severe intrauterine infection was found in group B. No adverse effect of HClO was seen. CONCLUSION: Intrauterine douche using HClO decreases postoperative intrauterine infection after MEA.","pmid":"32939904","doi":"10.1111/jog.14471","url":"https://pubmed.ncbi.nlm.nih.gov/32939904/"},{"id":1036,"title":"A visible-light-excitable mitochondria-targeted europium complex probe for hypochlorous acid and its application to time-gated luminescence bioimaging.","authors":"Ma, Hua; Chen, Kaiwen; Song, Bo; Tang, Zhixin; Huang, Yundi; Zhang, Ting; Wang, Huanan; Sun, Wenping; Yuan, Jingli","year":2020,"date":"2020 Nov 15","journal":"Biosensors & bioelectronics","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Development of fluorescent/luminescent probes for rapid, selective and sensitive detection of reactive oxygen species (ROS) is of great significance for understanding the roles of ROS in pathophysiological processes. In the present research, a visible-light-excitable Eu(3+) complex-based probe, Eu(L)(3)(DPBT), is designed and synthesized for the time-gated luminescence (TGL) determination of hypochlorous acid (HClO) in vitro and in vivo. The proposed probe exhibits a rapid, selective and sensitive TGL response to HClO, and excellent localization of mitochondria in living cells with low cytotoxicity. These features allow the probe to be used for the TGL sensing and imaging of HClO formation in mimic inflammatory cells at a subcellular level, as well as in endotoxin-induced liver injury and rheumatoid arthritis in live mice. In addition, by immobilizing the probe in the PEG hydrogel, the smart sensor films with rapid response to HClO were prepared, and successfully used for the real-time monitoring of HClO generation in mouse wounds, in order to distinguish the infected wounds from acute ones. Overall, this study provides a useful tool for the clinical monitoring and treatment of wound diseases.","pmid":"32890933","doi":"10.1016/j.bios.2020.112560","url":"https://pubmed.ncbi.nlm.nih.gov/32890933/"},{"id":1044,"title":"Roles of RcsA, an AhpD Family Protein, in Reactive Chlorine Stress Resistance and Virulence in Pseudomonas aeruginosa.","authors":"Nontaleerak, Benya; Duang-Nkern, Jintana; Wongsaroj, Lampet; Trinachartvanit, Wachareeporn; Romsang, Adisak; Mongkolsuk, Skorn","year":2020,"date":"2020 Oct 1","journal":"Applied and environmental microbiology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Reactive chlorine species (RCS), particularly hypochlorous acid (HOCl), are powerful antimicrobial oxidants generated by biological pathways and chemical syntheses. Pseudomonas aeruginosa is an important opportunistic pathogen that has adapted mechanisms for protection and survival in harsh environments, including RCS exposure. Based on previous transcriptomic studies of HOCl exposure in P. aeruginosa, we found that the expression of PA0565, or rcsA, which encodes an alkyl hydroperoxidase D-like protein, exhibited the highest induction among the RCS-induced genes. In this study, rcsA expression was dominant under HOCl stress and greatly increased under HOCl-related stress conditions. Functional analysis of RcsA showed that the distinguishing core amino acid residues Cys60, Cys63, and His67 were required for the degradation of sodium hypochlorite (NaOCl), suggesting an extended motif in the AhpD family. After allelic exchange mutagenesis in the P. aeruginosarcsA, the P. aeruginosarcsA deletion mutant showed significantly decreased HOCl resistance. Ectopic expression of P. aeruginosarcsA led to significantly increased NaOCl resistance in Escherichia coli Moreover, the pathogenicity of the rcsA mutant decreased dramatically in both Caenorhabditis elegans and Drosophila melanogaster host model systems compared to the wild type (WT). Finally, the Cys60, Cys63, and His67 variants of RcsA were unsuccessful at complementing phenotypes of the rcsA mutant. Overall, our data indicate the importance of P. aeruginosa RcsA in defense against HOCl stress under disinfections and during infections of hosts, which involves the catalytic Cys60, Cys63, and His67 residues.IMPORTANCEPseudomonas aeruginosa is a common pathogen that is a major cause of serious infections in many hosts. Hypochlorous acid (HOCl) is a potent antimicrobial agent found in household bleach and is a widely used disinfectant. P. aeruginosa has evolved adaptive mechanisms for protection and survival during HOCl exposure. We identified P. aeruginosarcsA as a HOCl-responsive gene encoding an antioxidant protein that may be involved in HOCl degradation. RcsA has a distinguishing core motif containing functional Cys60, Cys63, and His67 residues. P. aeruginosarcsA plays an important role in bleach tolerance, with expression of P. aeruginosarcsA in Escherichia coli also conferring HOCl resistance. Interestingly, RcsA is required for full virulence in worm and fruit fly infection models, indicating a correlation between mechanisms of bleach toxicity and host immunity during infection. This provides new insights into the mechanisms used by P. aeruginosa to persist in harsh environments such as hospitals.","pmid":"32801171","doi":"10.1128/AEM.01480-20","url":"https://pubmed.ncbi.nlm.nih.gov/32801171/"},{"id":1048,"title":"Evaluating the bactericidal action of hypochlorous acid in culture media.","authors":"Ashby, Louisa V; Springer, Reuben; Hampton, Mark B; Kettle, Anthony J; Winterbourn, Christine C","year":2020,"date":"2020 Nov 1","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The bactericidal activity of the physiological oxidant hypochlorous acid (HOCl) is commonly studied in a variety of laboratory media. Reactive with numerous targets, HOCl will rapidly lose its toxicity via reduction or be converted to chloramines and other less toxic species. The objective of this study was to test the influence of various media, temperature and reaction time on the toxicity of HOCl. After incubating bacteria in media dosed with reagent HOCl, the bactericidal outcome was measured by colony forming ability. In parallel, we determined the HOCl and chloramine content after dosing media alone. Our results showed that more reagent HOCl was required to kill bacteria in culture media than in aqueous buffer, and this corresponded to the lower concentration of reactive chlorine species achieved in the media. RPMI and MOPS minimal medium retained significant oxidising equivalents after HOCl-dosing, but more nutrient-rich media such as MEM, DMEM, LB and TSB, had higher scavenging capacity. Other factors that lowered the bactericidal strength of HOCl were longer lag-times and raised temperature when pre-dosing media, and insufficient incubation time of cells with the HOCl-treated media. In summary, we demonstrate that the choice of media as well as procedural details within experiments crucially impact the cellular toxicity of HOCl. These factors influence the nature and concentration of oxidants generated, and therefore are critical in affecting cellular responses.","pmid":"32739594","doi":"10.1016/j.freeradbiomed.2020.07.033","url":"https://pubmed.ncbi.nlm.nih.gov/32739594/"},{"id":1050,"title":"The novel HOCl fluorescent probe CAN induced A549 apoptosis by inhibiting chlorination activity of MPO.","authors":"An, Zaiyong; Zhao, Zhimin; Zhao, Lin; Yue, Qiulin; Li, Kunlun; Zhao, Baoxiang; Miao, Junying; Su, Le","year":2020,"date":"2020 Sep 15","journal":"Bioorganic & medicinal chemistry letters","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCl) is an important signaling molecule for cell survival. However, it has been reported that excessive HOCl contributes to a variety of diseases such as cancers. And in cancer cells, the level of HOCl is much higher than that in normal cells. Here a coumarin-based fluorescent probe 7-Diethylamino-3-(2,3-dihydro-1H-perimidin-2-yl)-chromen-2-one (CAN) was successfully developed for HOCl detection. The probe could be oxidized by HOCl to induce significant change in its fluorescence profile, which made it feasible for ratiometric detecting HOCl. CAN (below 1 µM) did not affect cell viability and had good capacity in ratiometric detection of HOCl in RAW 264.7 cells. CAN induced A549 apoptosis and inhibited tumor growth in vitro and in vivo. And CAN could decrease the chlorination activity of myeloperoxidase (MPO) in A549. These findings suggested that CAN (below 1 µM) would develop into a HOCl probe. High activity of MPO and level of HOCl might be helpful for A549 survival. A549 could be induced apoptosis by reducing the HOCl level by CAN. It implies a new anticancer strategy by targeting HOCl.","pmid":"32717611","doi":"10.1016/j.bmcl.2020.127394","url":"https://pubmed.ncbi.nlm.nih.gov/32717611/"},{"id":1056,"title":"The effects of neutrophil-generated hypochlorous acid and other hypohalous acids on host and pathogens.","authors":"Ulfig, Agnes; Leichert, Lars I","year":2021,"date":"2021 Jan","journal":"Cellular and molecular life sciences : CMLS","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"Neutrophils are predominant immune cells that protect the human body against infections by deploying sophisticated antimicrobial strategies including phagocytosis of bacteria and neutrophil extracellular trap (NET) formation. Here, we provide an overview of the mechanisms by which neutrophils kill exogenous pathogens before we focus on one particular weapon in their arsenal: the generation of the oxidizing hypohalous acids HOCl, HOBr and HOSCN during the so-called oxidative burst by the enzyme myeloperoxidase. We look at the effects of these hypohalous acids on biological systems in general and proteins in particular and turn our attention to bacterial strategies to survive HOCl stress. HOCl is a strong inducer of protein aggregation, which bacteria can counteract by chaperone-like holdases that bind unfolding proteins without the need for energy in the form of ATP. These chaperones are activated by HOCl through thiol oxidation (Hsp33) or N-chlorination of basic amino acid side-chains (RidA and CnoX) and contribute to bacterial survival during HOCl stress. However, neutrophil-generated hypohalous acids also affect the host system. Recent studies have shown that plasma proteins act not only as sinks for HOCl, but get actively transformed into modulators of the cellular immune response through N-chlorination. N-chlorinated serum albumin can prevent aggregation of proteins, stimulate immune cells, and act as a pro-survival factor for immune cells in the presence of cytotoxic antigens. Finally, we take a look at the emerging role of HOCl as a potential signaling molecule, particularly its role in neutrophil extracellular trap formation.","pmid":"32661559","doi":"10.1007/s00018-020-03591-y","url":"https://pubmed.ncbi.nlm.nih.gov/32661559/"},{"id":1057,"title":"Hypochlorite-induced porcine model of peritoneal fibrosis through the activation of IL1β-CX3CL1-TGFβ1 signal axis.","authors":"Hsu, Yu-Ting; Wu, Ching-Ho; Chao, Chun-Yuan; Wei, Yu-Syuan; Chang, Yen-Chen; Chen, Yi-Ting; Lin, Shuei-Liong; Tsai, Su-Yi; Lee, Ya-Jane; Tsai, Pei-Shiue","year":2020,"date":"2020 Jul 13","journal":"Scientific reports","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Patients with kidney failure rely on life-saving peritoneal dialysis to facilitate waste exchange and maintain homeostasis of physical conditions. However, peritoneal dialysis often results in peritoneal fibrosis and organ adhesion that subsequently compromise the efficiency of peritoneal dialysis and normal functions of visceral organs. Despite rodent models provide clues on the pathogenesis of peritoneal fibrosis, no current large animal model which shares high degree of physiological and anatomical similarities to human is available, limiting their applications on the evaluation of pre-clinical therapeutic efficacy. Here we established for the first time, hypochlorite-induced porcine model of peritoneal fibrosis in 5-week-old piglets. We showed that administration 15-30 mM hypochlorite, a dose- and time-dependent severity of peritoneal fibrosis characterized by mesothelium fragmentation, αSMA(+) myofibroblasts accumulation, organ surface thickening and type I collagen deposition were observed. We also demonstrated in vitro using human mesothelial cells that hypochlorite-induced fibrosis was likely due to necrosis, but not programmed apoptosis; besides, overexpression of IL1β, CX3CL1 and TGFβ on the peritoneal mesothelium in current model was detected, similar to observations from peritoneal dialysis-induced peritoneal fibrosis in human patients and earlier reported mouse model. Moreover, our novel antemortem evaluation using laparoscopy provided instant feedback on the progression of organ fibrosis/adhesion which allows immediate adjustments on treatment protocols and strategies in alive individuals that can not and never be performed in other animal models.","pmid":"32661265","doi":"10.1038/s41598-020-68495-0","url":"https://pubmed.ncbi.nlm.nih.gov/32661265/"},{"id":1059,"title":"Hypochlorous Acid: A Review.","authors":"Block, Michael S; Rowan, Brian G","year":2020,"date":"2020 Sep","journal":"Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"The surgeon needs to have an inexpensive, available, nontoxic, and practical disinfectant that is effective in sanitizing against the COVID-19 (Coronavirus Disease 2019) virus. The purpose of this article was to review the evidence for using hypochlorous acid in the office setting on a daily basis. The method used to assemble recommendations was a review of the literature including evidence for this solution when used in different locations and industries other than the oral-maxillofacial clinic facility. The results indicate that this material can be used with a high predictability for disinfecting against the COVID-19 (Coronavirus Disease 2019) virus.","pmid":"32653307","doi":"10.1016/j.joms.2020.06.029","url":"https://pubmed.ncbi.nlm.nih.gov/32653307/"},{"id":1060,"title":"Preliminary Outcomes of Hypochlorous Acid as an Adjunct for Pocket Irrigation in Revision Aesthetic Breast Surgery.","authors":"Hasan, Samir; Mujadzic, Mirza; Kaswan, Sumesh; Halpern, Joshua; Van Natta, Bruce; Lund, Herluf","year":2021,"date":"2021 Mar 12","journal":"Aesthetic surgery journal","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Capsular contracture is a challenging problem for plastic surgeons despite advances in surgical technique. Breast pocket irrigation decreases bacterial bioburden. Studies have shown that hypochlorous acid (HOCl; PhaseOne Health, Nashville, TN) effectively penetrates and disrupts biofilms; however, there are limited clinical data regarding this irrigation in breast augmentation. OBJECTIVES: The aim of this study was to investigate the effects of HOCl pocket irrigation in revision breast augmentation by evaluating rates of capsular contracture recurrence, infection, and allergic reactions. METHODS: We performed an institutional review board-approved retrospective chart review of revision breast augmentation cases for Baker grade III/IV capsular contractures in which pockets were irrigated with HOCl. Data were obtained from 3 board-certified plastic surgeons. RESULTS: The study included 135 breasts in 71 patients, who ranged in age from 27 to 77 years (mean, 53.7 years). Follow-up ranged from 12 to 41 months (mean, 20.2 months). Postoperatively, there were 2 unilateral Baker grade III/IV recurrences at 13 months and 1 bilateral Baker grade II recurrence at 3 months. There were no infections or allergic reactions. The overall Baker grade III/IV capsular contracture recurrence rate was 0% at 12 months and 1.5% at 15 months. CONCLUSIONS: Breast pocket irrigation decreases bioburden, which may influence capsular contracture recurrence. We evaluated 3 varied applications of HOCl in revision aesthetic breast surgery and found a low capsular contracture recurrence rate and no adverse reactions. We plan to report our findings with HOCl in primary breast augmentation in the future, and other studies are being conducted on the efficacy of HOCl in aesthetic surgery.","pmid":"32651995","doi":"10.1093/asj/sjaa201","url":"https://pubmed.ncbi.nlm.nih.gov/32651995/"},{"id":1062,"title":"The Chlorination of N-Methyl Amino Acids with Hypochlorous Acid: Kinetics and Mechanisms.","authors":"Simon, Fruzsina; Kiss, Eszter; Szabó, Mária; Fábián, István","year":2020,"date":"2020 Aug 17","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The formation and decomposition kinetics of N-chloro-N-methyl amino acids were studied to predict the fate and impact of these compounds in water treatment technologies and biological systems. These compounds form in fast second-order reactions between N-methyl amino acids and hypochlorous acid. The comparison of the activation parameters for the reactions of N-methyl substituted and nonsubstituted branched-chain amino acids reveals the transition-state features less organized structure and stronger bonds between the reactants in the reactions with the N-methyl derivatives. This is due to a combined positive inductive effect of the N-methyl group and the alkyl side chain as well as to the steric effects of the substituents. N-Methyl-N-chloro amino acids decompose much faster than the nonsubstituted compounds. The reaction rates do not depend on the pH, and the same final product is formed in the entire pH range. N-Chlorosarcosine is an exception, as it decomposes via competing paths, k(d)(obs) = k(d) + k(d)(OH)[OH(-)], yielding different final products. This feature is most likely due to the lack of an alkyl substituent on the α-carbon atom. Under physiological pH, aldehydes and methylamine form in these reactions, which are not particularly toxic.","pmid":"32633499","doi":"10.1021/acs.chemrestox.0c00222","url":"https://pubmed.ncbi.nlm.nih.gov/32633499/"},{"id":1075,"title":"The composition of chlorinated or oxidized phosphatidylcholine products changes with hypochlorite concentration: Application to abscess lipid analysis.","authors":"Hoshioka, Yumi; Abe, Hiroko; Yajima, Daisuke; Makino, Yohsuke; Yamaguchi, Rutsuko; Saitoh, Hisako; Inokuchi, Go; Motomura, Ayumi; Nagasawa, Sayaka; Iwase, Hirotaro","year":2020,"date":"2020 Sep","journal":"Legal medicine (Tokyo, Japan)","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid, produced by myeloperoxidase upon neutrophil activation, can oxidize various compounds and exert antimicrobial activity in vivo. To elucidate the mechanisms underlying the reactions of the unsaturated phosphatidylcholines, which abound in cell membranes, with hypochlorous acid, we identified and examined phosphatidylcholine chlorination and oxidation products formed under various reaction conditions. We first investigated the products of unsaturated phosphatidylcholine and hypochlorous acid reaction with respect to hypochlorite concentration and reaction time. Next, we examined the lipids extracted postmortem from human abscesses. For all the analyses, we used liquid chromatography-quadrupole time-of-flight mass spectrometry. Various compounds, including phosphatidylcholine chlorohydrin and phosphatidylcholine hydroxide/epoxide, were detected. Oxidized phosphatidylcholines were mainly detectable upon reaction with low concentrations of sodium hypochlorite, whereas chlorinated phosphatidylcholines formed in the presence of higher concentrations. In human abscesses, oxidized phosphatidylcholines were detected in the cases with high procalcitonin concentration, whereas chlorinated phosphatidylcholines were undetected. The detections of oxidized phosphatidylcholines in human tissues might indicate previous exposure to hypochlorous acid in septic cases. Our results provide insight into the mechanisms underlying pathogen survival following inflammation associated with neutrophil activation and topical myeloperoxidase release and show postmortem biomarkers candidates for sepsis.","pmid":"32516737","doi":"10.1016/j.legalmed.2020.101724","url":"https://pubmed.ncbi.nlm.nih.gov/32516737/"},{"id":1078,"title":"Evidence-Based Review of Antibiofilm Agents for Wound Care.","authors":"Weigelt, Maximillian A; McNamara, Stephanie A; Sanchez, Daniela; Hirt, Penelope A; Kirsner, Robert S","year":2021,"date":"2021 Jan","journal":"Advances in wound care","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"Significance: Biofilms in vivo are small densely packed aggregations of microbes that are highly resistant to host immune responses and treatment. They attach to each other and to nearby surfaces. Biofilms are difficult to study and identify in a clinical setting as their quantification necessitates the use of advanced microscopy techniques such as confocal laser scanning microscopy. Nonetheless, it is likely that biofilms contribute to the pathophysiology of chronic skin wounds. Reducing, removing, or preventing biofilms is thus a logical approach to help clinicians heal chronic wounds. Recent Advances: Wound care products have demonstrated varying degrees of efficacy in destroying biofilms in in vitro and preclinical models, as well as in some clinical studies. Critical Issues: Controlled studies exploring the beneficial role of biofilm eradication and its relationship to healing in patients with chronic wounds are limited. This review aims to discuss the mode of action and clinical significance of currently available antibiofilm products, including surfactants, dressings, and others, with a focus on levels of evidence for efficacy in disrupting biofilms and ability to improve wound healing outcomes. Future Directions: Few available products have good evidence to support antibiofilm activity and wound healing benefits. Novel therapeutic strategies are on the horizon. More high-quality clinical studies are needed. The development of noninvasive techniques to quantify biofilms will facilitate increased ease of research about biofilms in wounds and how to combat them.","pmid":"32496980","doi":"10.1089/wound.2020.1193","url":"https://pubmed.ncbi.nlm.nih.gov/32496980/"},{"id":1084,"title":"Epileptic brain fluorescent imaging reveals apigenin can relieve the myeloperoxidase-mediated oxidative stress and inhibit ferroptosis.","authors":"Shao, Chenwen; Yuan, Jiwen; Liu, Yani; Qin, Yajuan; Wang, Xueao; Gu, Jin; Chen, Guiquan; Zhang, Bing; Liu, Hong-Ke; Zhao, Jing; Zhu, Hai-Liang; Qian, Yong","year":2020,"date":"2020 May 12","journal":"Proceedings of the National Academy of Sciences of the United States of America","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Myeloperoxidase (MPO)-mediated oxidative stress has been suggested to play an important role in the pathological dysfunction of epileptic brains. However, there is currently no robust brain-imaging tool to detect real-time endogenous hypochlorite (HClO) generation by MPO or a fluorescent probe for rapid high-throughput screening of antiepileptic agents that control the MPO-mediated chlorination stress. Herein, we report an efficient two-photon fluorescence probe (named HCP) for the real-time detection of endogenous HClO signals generated by MPO in the brain of kainic acid (KA)-induced epileptic mice, where HClO-dependent chlorination of quinolone fluorophore gives the enhanced fluorescence response. With this probe, we visualized directly the endogenous HClO fluxes generated by the overexpression of MPO activity in vivo and ex vivo in mouse brains with epileptic behaviors. Notably, by using HCP, we have also constructed a high-throughput screening approach to rapidly screen the potential antiepileptic agents to control MPO-mediated oxidative stress. Moreover, from this screen, we identified that the flavonoid compound apigenin can relieve the MPO-mediated oxidative stress and inhibit the ferroptosis of neuronal cells. Overall, this work provides a versatile fluorescence tool for elucidating the role of HClO generation by MPO in the pathology of epileptic seizures and for rapidly discovering additional antiepileptic agents to prevent and treat epilepsy.","pmid":"32327603","doi":"10.1073/pnas.1917946117","url":"https://pubmed.ncbi.nlm.nih.gov/32327603/"},{"id":1088,"title":"Effect of physio-chemical seed treatments on opium poppy downy mildews caused by Peronospora meconopsidis and P. somniferi.","authors":"Thangavel, Tamilarasan; Scott, Jason; Jones, Suzanne; Gugalothu, Ramya; Wilson, Calum","year":2020,"date":"2020","journal":"PloS one","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Downy mildew of opium poppy is the single biggest disease constraint afflicting the Australian poppy industry. Within the pathosystem, the transmission of infections via infested seed is of major concern. Both downy mildew pathogens of poppy; Peronospora meconopsidis and P. somniferi, are known contaminants of commercial seed stocks. Using seed naturally infested with these pathogens, the effect of physio-chemical seed treatments on seedling health and disease transmission were evaluated. Individual seed treatments were tested to determine optimal treatment parameters for each; including incubation time, temperature and treatment concentration. Optimised physiochemical treatments were then compared. The most effective treatment methods were seed washes in acidified electrolytic water (400 ppm hypochlorous acid for 5 min) and hypochlorite solution (2% NaOCI for 5 min). In seed to seedling transmission assays, these two treatments reduced transmission of P. somniferi by 88.8% and 74.61%, and P. meconopsidis by 93.3% and 100%, respectively. These methods are recommended for seed treatment of commercial opium poppy seed to assist in the control of the downy mildew diseases.","pmid":"32275719","doi":"10.1371/journal.pone.0230801","url":"https://pubmed.ncbi.nlm.nih.gov/32275719/"},{"id":1090,"title":"Hypochlorous acid-generating electrochemical scaffold eliminates Candida albicans biofilms.","authors":"Zmuda, H M; Mohamed, A; Raval, Y S; Call, D R; Schuetz, A N; Patel, R; Beyenal, H","year":2020,"date":"2020 Oct","journal":"Journal of applied microbiology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"AIMS: Wound infections involving Candida albicans can be challenging to treat because of the fungus' ability to penetrate wound tissue and form biofilms. The goal of this study was to assess the activity of a hypochlorous acid (HOCl)-generating electrochemical scaffold (e-scaffold) against C. albicans biofilms in vitro and on porcine dermal explants (ex vivo). METHODS AND RESULTS: C. albicans biofilms were grown either on acrylic-bottom six-well plates (in vitro) or on skin tissue excised from porcine ears (ex vivo), and the polarized e-scaffold was used to generate a continuous supply of low concentration HOCl near biofilm surfaces. C. albicans biofilms grown in vitro were reduced to undetectable amounts within 24 h of e-scaffold exposure, unlike control biofilms (5·28 ± 0·034 log(10) (CFU cm(-) (2) ); P < 0·0001). C. albicans biofilms grown on porcine dermal explants were also reduced to undetectable amounts in 24 h, unlike control explant biofilms (4·29 ± 0·057 log(10) (CFU cm(-) (2) ); P < 0·0001). There was a decrease in the number of viable mammalian cells (35·6 ± 6·4%) in uninfected porcine dermal explants exposed to continuous HOCl-generating e-scaffolds for 24 h compared to explants exposed to nonpolarized e-scaffolds (not generating HOCl) (P < 0·05). CONCLUSIONS: Our HOCl-generating e-scaffold is a potential antifungal-free strategy to treat C. albicans biofilms in chronic wounds. SIGNIFICANCE AND IMPACT OF THE STUDY: Wound infections caused by C. albicans are difficult to treat due to presence of biofilms in wound beds. Our HOCl producing e-scaffold provides a promising novel approach to treat wound infections caused by C. albicans.","pmid":"32249986","doi":"10.1111/jam.14656","url":"https://pubmed.ncbi.nlm.nih.gov/32249986/"},{"id":1098,"title":"A multimodel regime for evaluating effectiveness of antimicrobial wound care products in microbial biofilms.","authors":"Stoffel, Joseph J; Kohler Riedi, Petra L; Hadj Romdhane, Brittany","year":2020,"date":"2020 Jul","journal":"Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Microbial biofilms have become increasingly recognized as a cause of wound chronicity. There are several topical antimicrobial wound care products available for use; however, their effectiveness has routinely been demonstrated with planktonic microorganisms. There is no target reference value for antimicrobial effectiveness of wound care products in biofilm models. In addition, data on antimicrobial activity of products in biofilm models are scattered across many test methods in a variety of studies. The aim of this work is to directly compare commercial products containing the commonly used topical antimicrobial agents iodine, silver, polyhexamethylene biguanide, octenidine, hypochlorous acid, benzalkonium chloride, and a surfactant-based topical containing poloxamer 188. Five different in vitro biofilm models of varied complexity were used, incorporating several bacterial pathogens such as Staphylococcus, Enterococcus, Streptococcus, Pseudomonas, Acinetobacter, Klebsiella, and Enterobacter. The fungal pathogens Candida albicans and Candida auris were also evaluated. A multispecies bacterial biofilm model was also used to evaluate the products. Additionally, C. albicans was used in combination with S. aureus and P. aeruginosa in a multikingdom version of the polymicrobial biofilm model. Statistically significant differences in antimicrobial performance were observed between treatments in each model and changing microbial growth conditions or combinations of organisms resulted in significant performance differences for some treatments. The iodine and benzalkonium chloride-containing products were overall the most effective in vitro and were then selected for in vivo evaluation in an infected immunocompromised murine model. Unexpectedly, the iodine product was statistically (P > .05) no different than the untreated control, while the benzalkonium chloride containing product significantly (P < .05) reduced the biofilm compared to untreated control. This body of work demonstrates the importance of not only evaluating antimicrobial wound care products in biofilm models but also the importance of using several different models to gain a comprehensive understanding of products' effectiveness.","pmid":"32175636","doi":"10.1111/wrr.12806","url":"https://pubmed.ncbi.nlm.nih.gov/32175636/"},{"id":1100,"title":"Intraabdominal Lavage of Hypochlorous Acid: A New Paradigm for the Septic and Open Abdomen.","authors":"Fernández, Luis G; Matthews, Marc R; Seal, Lawton","year":2020,"date":"2020 Apr","journal":"Wounds : a compendium of clinical research and practice","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"INTRODUCTION: Management of the open abdomen (OA) has rapidly evolved over the last several decades due to the improved understanding of the underlying pathophysiology of patients with an OA, adoption of damage control surgery, and the use of temporary abdominal closure (TAC) techniques for this patient population. The TAC utilizing negative pressure has been successful for managing patients with an OA with improved time to closure. Recent studies have started to examine the use of TAC in conjunction with negative pressure wound therapy with instillation and dwell time (NPWTi-d) for the management of the OA. OBJECTIVE: This case series illustrates the capability, safety, and clinical effectiveness of TAC/NPWTi-d with hypochlorous acid (HOCl) solution. MATERIALS AND METHODS: Three successfully treated cases describe the use of NPWTi-d using HOCl solution for the management of patients with a septic OA. RESULTS: This initial experience suggests instillation of HOCl through the tubing set, in conjunction with the TAC device, is safe and easy to use. This technique decreased the need for more frequent OA lavages in the operating room (OR) after the index procedure, as well as the associated concomitant risks of transporting patients who are critically ill between the SICU and OR. No acute complications related to the TAC device with HOCl were noted. CONCLUSIONS: Based on the results of this study, the authors believe instillation through the TAC device may be the next evolution in the use of abdominal NPWT and programmed intermittent lavage of the peritoneal cavity represents an effective method in the care of patients with a septic OA.","pmid":"32155118","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/32155118/"},{"id":1101,"title":"Bacterial Defense Systems against the Neutrophilic Oxidant Hypochlorous Acid.","authors":"Sultana, Sadia; Foti, Alessandro; Dahl, Jan-Ulrik","year":2020,"date":"2020 Jun 22","journal":"Infection and immunity","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"Neutrophils kill invading microbes and therefore represent the first line of defense of the innate immune response. Activated neutrophils assemble NADPH oxidase to convert substantial amounts of molecular oxygen into superoxide, which, after dismutation into peroxide, serves as the substrate for the generation of the potent antimicrobial hypochlorous acid (HOCl) in the phagosomal space. In this minireview, we explore the most recent insights into physiological consequences of HOCl stress. Not surprisingly, Gram-negative bacteria have evolved diverse posttranslational defense mechanisms to protect their proteins, the main targets of HOCl, from HOCl-mediated damage. We discuss the idea that oxidation of conserved cysteine residues and partial unfolding of its structure convert the heat shock protein Hsp33 into a highly active chaperone holdase that binds unfolded proteins and prevents their aggregation. We examine two novel members of the Escherichia coli chaperone holdase family, RidA and CnoX, whose thiol-independent activation mechanism differs from that of Hsp33 and requires N-chlorination of positively charged amino acids during HOCl exposure. Furthermore, we summarize the latest findings with respect to another bacterial defense strategy employed in response to HOCl stress, which involves the accumulation of the universally conserved biopolymer inorganic polyphosphate. We then discuss sophisticated adaptive strategies that bacteria have developed to enhance their survival during HOCl stress. Understanding bacterial defense and survival strategies against one of the most powerful neutrophilic oxidants may provide novel insights into treatment options that potentially compromise the ability of pathogens to resist HOCl stress and therefore may increase the efficacy of the innate immune response.","pmid":"32152198","doi":"10.1128/IAI.00964-19","url":"https://pubmed.ncbi.nlm.nih.gov/32152198/"},{"id":1103,"title":"Ratiometric electrochemical molecular switch for sensing hypochlorous acid: Applicable in food analysis and real-time in-situ monitoring.","authors":"Kumaravel, Sakthivel; Balamurugan, T S T; Jia, Shun-Hong; Lin, Hsin-Yi; Huang, Sheng-Tung","year":2020,"date":"2020 Apr 15","journal":"Analytica chimica acta","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"A ratiometric electrochemical molecular sensing platform for real-time quantification of extracellular hypochlorous acid (HClO) production has been developed based on a latent electrochemical probe aminoferrocene thiocarbamate (AFTC 3). The substrate AFTC consist of a masked redox reporter amino ferrocene (AF 4) linked with a dimethylthiocarbamate trigger via hydroxyl benzyl alcohol. The conceptual idea behind the probe design is based on a specific chemical interaction between HClO and dimethylthiocarbamate, which allows only HClO to unmask the probe to releases AF. The scheme was manipulated to establish a highly selective (in presence of various reactive oxygen species, anions and other biological interfering species) and sensitive (detection limit 75 nM) sensing platform not only in lab samples but also in real samples (food samples, and live cells). Real-time in situ quantification platform was developed to profile HClO productions in macrophages, and it did so with great consistency.","pmid":"32145845","doi":"10.1016/j.aca.2020.01.065","url":"https://pubmed.ncbi.nlm.nih.gov/32145845/"},{"id":1113,"title":"Disinfection by-products and ecotoxic risk associated with hypochlorite treatment of irbesartan.","authors":"Romanucci, Valeria; Siciliano, Antonietta; Guida, Marco; Libralato, Giovanni; Saviano, Lorenzo; Luongo, Giovanni; Previtera, Lucio; Di Fabio, Giovanni; Zarrelli, Armando","year":2020,"date":"2020 Apr 10","journal":"The Science of the total environment","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Recently, many studies highlighted the consistent finding of irbesartan in effluents from wastewater treatment plants (WWTPs) and in some rivers and lakes in both Europe and North America, suggesting that no >80% can be removed by specific treatments. The present investigation attempts to study the chemical fate of irbesartan in a simulated chlorination step, mimicking the conditions of a WWTP. A total of six disinfection by-products were identified, five were completely new, and separated on a C-18 column by employing a gradient HPLC method. Initially, a complete mass fragmentation pathway of the drug was established with the help of MS/TOF, and subsequently, the disinfection by-products were subjected to MS/TOF mass studies to obtain their mass and fragment pattern. The MS results helped to assign tentative structures to the disinfection products, which were verified through 1D and 2D NMR experiments. The chemical structures of the new compounds have been justified by a proposed mechanism of formation. A preliminary ecotoxicity assessment with the crustacean Daphnia magna showed that some of the identified by-products were up to 12-times more toxic than irbesartan.","pmid":"32050394","doi":"10.1016/j.scitotenv.2019.135625","url":"https://pubmed.ncbi.nlm.nih.gov/32050394/"},{"id":1121,"title":"The Role of Myeloperoxidase in Biomolecule Modification, Chronic Inflammation, and Disease.","authors":"Davies, Michael J; Hawkins, Clare L","year":2020,"date":"2020 May 1","journal":"Antioxidants & redox signaling","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"Significance: The release of myeloperoxidase (MPO) by activated leukocytes is critical in innate immune responses. MPO produces hypochlorous acid (HOCl) and other strong oxidants, which kill bacteria and other invading pathogens. However, MPO also drives the development of numerous chronic inflammatory pathologies, including atherosclerosis, neurodegenerative disease, lung disease, arthritis, cancer, and kidney disease, which are globally responsible for significant patient mortality and morbidity. Recent Advances: The development of imaging approaches to precisely identify the localization of MPO and the molecular targets of HOCl in vivo is an important advance, as typically the involvement of MPO in inflammatory disease has been inferred by its presence, together with the detection of biomarkers of HOCl, in biological fluids or diseased tissues. This will provide valuable information in regard to the cell types responsible for releasing MPO in vivo, together with new insight into potential therapeutic opportunities. Critical Issues: Although there is little doubt as to the value of MPO inhibition as a protective strategy to mitigate tissue damage during chronic inflammation in experimental models, the impact of long-term inhibition of MPO as a therapeutic strategy for human disease remains uncertain, in light of the potential effects on innate immunity. Future Directions: The development of more targeted MPO inhibitors or a treatment regimen designed to reduce MPO-associated host tissue damage without compromising pathogen killing by the innate immune system is therefore an important future direction. Similarly, a partial MPO inhibition strategy may be sufficient to maintain adequate bacterial activity while decreasing the propagation of inflammatory pathologies.","pmid":"31989833","doi":"10.1089/ars.2020.8030","url":"https://pubmed.ncbi.nlm.nih.gov/31989833/"},{"id":1123,"title":"Antimicrobial efficacy of a very stable hypochlorous acid formula compared with other antiseptics used in treating wounds: in-vitro study on micro-organisms with or without biofilm.","authors":"Herruzo, R; Herruzo, I","year":2020,"date":"2020 Jun","journal":"The Journal of hospital infection","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: Many antiseptics have been used to treat wounds. AIM: To compare the microbicidal efficacy of ClHO (Clortech®) with other antiseptics used on wounds, healthy skin and mucous membranes. METHODS: The microbicidal efficacy of 13 antiseptic products on eight micro-organisms (three Gram-positive; three Gram-negative; two yeasts) inoculated on organic germ-carriers was studied. In addition, the loss of efficacy against Staphylococcus aureus and Pseudomonas aeruginosa with biofilm was assessed with the six best-performing products. FINDINGS: Chlorhexidine (1%) had the highest microbicidal effect at 1 min. At 5 min, 500 and 1500 mg/L ClHO showed similar, or better, activity than the other antiseptics studied. The ClHO concentration of 300 mg/L achieved this same efficacy at 10 min. The product that lost the most efficacy due to biofilm was 1% chlorhexidine, while 1% PVP-I and ClHO at either 300 or 500 mg/L were moderately affected by biofilm. The most effective in the presence of biofilm was ClHO at 1500 mg/L. CONCLUSIONS: ClHO at medium-low concentrations (300 or 500 mg/L) is a good antiseptic that can be used on wounds and mucous membranes for 5-10 min. Lower concentrations of ClHO, as well as of the other antiseptics studied, were less effective or more altered by the biofilm. ClHO at a concentration of 1500 mg/L is very effective in the presence or absence of biofilm that can be used on healthy skin for 5 min.","pmid":"31987843","doi":"10.1016/j.jhin.2020.01.013","url":"https://pubmed.ncbi.nlm.nih.gov/31987843/"},{"id":1125,"title":"Structural Study on Hypochlorous Acid-Mediated Chlorination of Betanin and Its Decarboxylated Derivatives from an Anti-Inflammatory Beta vulgaris L. Extract.","authors":"Kumorkiewicz-Jamro, Agnieszka; Starzak, Karolina; Sutor, Katarzyna; Nemzer, Boris; Pietrzkowski, Zbigniew; Popenda, Łukasz; Wybraniec, Sławomir","year":2020,"date":"2020 Jan 16","journal":"Molecules (Basel, Switzerland)","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HOCl) produced by neutrophils is a part of the natural innate immune response system in the human body, but excessive levels of HOCl can ultimately be detrimental to health. Recent reports suggest that betacyanin plant pigments can act as potent scavengers of inflammatory factors and are notably effective against HOCl. In this contribution, chlorination mechanism and position of the electrophilic substitution in betacyanins was studied by high-resolution mass spectrometry and further structural analyses by NMR techniques, which completed the identification of the chlorinated betacyanins. For the study on the influence of the position of decarboxylation on the chlorination mechanism, a comparison of the chlorination position between betanin as well as 17-, and 2,17-decarboxylated betanins was performed. The structural study confirmed that the chlorination position in betanin occurs within the dihydropyridinic moiety at carbon C-18. Therefore, out of the aqueous free chlorine equilibrium species: HOCl, OCl(-), Cl(2), and Cl(2)O, the most potent chlorinating agents are HOCl and Cl(2)O postulated previously and the attack of the Cl(⁺) ion on the carbon C-18 with a cyclic intermediate version is considered.","pmid":"31963358","doi":"10.3390/molecules25020378","url":"https://pubmed.ncbi.nlm.nih.gov/31963358/"},{"id":1132,"title":"Enhancement of the Aggregation-Induced Emission by Hydrogen Bond for Visualizing Hypochlorous Acid in an Inflammation Model and a Hepatocellular Carcinoma Model.","authors":"Han, Xiaomin; Ma, Yufan; Chen, Yuzhi; Wang, Xuefei; Wang, Zhuo","year":2020,"date":"2020 Feb 4","journal":"Analytical chemistry","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"As an important reactive oxygen species, hypochlorous acid (HClO) is produced in various physiological processes. The abnormal rise of the HClO level is associated with a large number of inflammatory diseases. In this work, we develop a simple, aqueous-soluble aggregration-induced emission (AIE) probe for sensing HClO with significant aggregation-induced fluorescence (>1000 times). Two probes, CH(3)O-TPE-Py(+)-N(+) (COTN) and OH-TPE-Py(+)-N(+) (HOTN) (TPE, tetraphenylethylene), are synthesized for sensing HClO by the cleavage of the Py(+)-N(+) group; the reaction products are CH(3)O-TPE-CHO (COT) and OH-TPE-CHO (HOT), respectively. The hydrophobicity of the probes is changed with the increased aggregation-induced emission. During the process, HOTN shows significantly better response than COTN. The slightly different chemical structures of COTN and HOTN result in a significant response to HClO. The theoretical calculation data support the theory that the hydrogen bond contributes to the excellent sensitivity for HClO. On the basis of the good response to HClO in vitro, HOTN is used to image inflammation and hepatocellular carcinoma in vivo because these diseases always produce high HClO levels.","pmid":"31913021","doi":"10.1021/acs.analchem.9b05347","url":"https://pubmed.ncbi.nlm.nih.gov/31913021/"},{"id":1134,"title":"Short-Term Guideline Values for Chlorine in Marine Waters.","authors":"Batley, Graeme E; Simpson, Stuart L","year":2020,"date":"2020 Apr","journal":"Environmental toxicology and chemistry","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"Chlorination is commonly used to control biofouling organisms, but chlorine rapidly hydrolyzes in seawater to hypochlorite, which undergoes further reaction with bromide, and then with organic matter. These reaction products, collectively termed chlorine-produced oxidants (CPOs), can be toxic to marine biota. Because the lifetime of the most toxic forms is limited to several days, appropriate guideline values need to be based on short-term (acute) toxicity tests, rather than chronic tests. Flow-through toxicity tests that provide continuous CPO exposure are the most appropriate, whereas static-renewal tests generate variable exposure and effects depending on the renewal rate. There are literature data for acute CPO toxicity from flow-through tests, together with values from 2 sensitive 15-min static tests on 30 species from 9 taxonomic groups. These values were used in a species sensitivity distribution (SSD) to derive guideline values that were protective of 99, 95, and 90% of species at 2.2, 7.2, and 13 µg CPO/L respectively. These are the first marine guideline values for chlorine to be derived using SSDs, with all other international guideline values based on the use of assessment factors applied to data for the most sensitive species. In applying these conservative guideline values in field situations, it would need to be demonstrated that concentrations of CPOs would be reduced to below the guideline value within an acceptable mixing zone through both dilution and dissociation. Environ Toxicol Chem 2020;39:754-764. © 2020 SETAC.","pmid":"31907965","doi":"10.1002/etc.4661","url":"https://pubmed.ncbi.nlm.nih.gov/31907965/"},{"id":1135,"title":"Developing chlorine-based antiseptic by electrolysis.","authors":"Mourad, Khaldoon A; Hobro, Sture","year":2020,"date":"2020 Mar 20","journal":"The Science of the total environment","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The use of Alcohol-based antiseptics is efficient and approved, however it has some limitations. This paper examined the possibility of using hypochlorite water as a chlorine-based antiseptic for handwashing in public buildings and healthcare facilities. The electrolysis method was used, which produces Hypochlorous acid (HOCl) from mixing drinking water with small amounts of sodium hydroxide. Hypochlorous acid is usually produced by blood cells to surround pathogens when the skin is cut and exposed to pathogens. The methods used were based on hydrolysing drinking water at a different salt concentration (from 0 up to saline water 0.9% NaCl) under the different power supply. The results showed that 0.005-0.01% hydrochloride water can be a perfect antiseptic that can kill most bacteria and pathogenies within 12 s. In one prototype set up one litter of the prepared solution needed the only 2 g of NaCl, 12 V and 3 amps' power. However, the pH value should be maintained to be around 5-6. The results also showed that the most efficient way was to produce the solution on-site. However, if stored properly it can be used for 7-10 days after production.","pmid":"31905555","doi":"10.1016/j.scitotenv.2019.136108","url":"https://pubmed.ncbi.nlm.nih.gov/31905555/"},{"id":1136,"title":"Topical stabilized hypochlorous acid: The future gold standard for wound care and scar management in dermatologic and plastic surgery procedures.","authors":"Gold, Michael H; Andriessen, Anneke; Bhatia, Ashish C; Bitter, Patrick Jr; Chilukuri, Suneel; Cohen, Joel L; Robb, Chris W","year":2020,"date":"2020 Feb","journal":"Journal of cosmetic dermatology","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"BACKGROUND: Hypochlorous acid (HOCl), a naturally occurring molecule produced by the immune system, is highly active against bacterial, viral, and fungal microorganisms. Moreover, HOCl is active against biofilm and increases oxygenation of the wound site to improve healing. Natural HOCl is unstable; through technology, it can be stabilized into an effective topical antiseptic agent. AIM: This paper focuses on the use of topical stabilized HOCl in wound and scar management for pre-, peri-, and postprocedures-including its ability to reduce the occurrence hypertrophic scars and keloids. The role of the product in other skin conditions is beyond the scope of this article. METHODS: A panel comprising clinicians with experience in cosmetic and surgical procedures met late 2018 to discuss literature search results and their own current clinical experience regarding topical stabilized HOCl. The panel of key opinion leaders in dermatology and plastic surgery defined key insights and consensus statements on the direction of use for the product. RESULTS: Topical stabilized HOCl provides an optimal wound healing environment and, when combined with silicone, may be ideal for reducing scarring. Additionally, in contrast to chlorhexidine, HOCl, used as an antiseptic skin preparation, raises no concerns of ocular- or ototoxicity. CONCLUSIONS: For wound care and scar management, topical stabilized HOCl conveys powerful microbicidal and antibiofilm properties, in addition to potency as a topical wound healing agent. It may offer physicians an alternative to other less desirable wound care measures.","pmid":"31904191","doi":"10.1111/jocd.13280","url":"https://pubmed.ncbi.nlm.nih.gov/31904191/"},{"id":1146,"title":"Evaluating the effectiveness of HOCl application on odor reduction and earthworm population growth during vermicomposting of food waste employing Eisenia fetida.","authors":"Kim, Chanwoo; Her, Younggu; Kim, Yooan; Jung, Chanhoon; Lim, Hangkyo; Suh, Kyo","year":2019,"date":"2019","journal":"PloS one","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Vermicomposting has been recommended as an eco-friendly method to transform organic waste into nutrient resources with minimum energy input. However, odor and pest issues associated with this method limit the use of vermicomposting, especially in indoor conditions. This study evaluated the effectiveness of applying hypochlorous acid (HOCl) to deodorize the vermicomposting process and improve the breeding environment for earthworms (Eisenia fetida). The deodorization performance of HOCl was compared by measuring the amount of ammonia (NH3) and amine (R-NH2) released from the decaying process of two types of food waste: HOCl-treated (HTW) waste and non-treated waste (NTW). The total and individual weights of earthworms in the waste treated with HOCl was measured to evaluate the impact on earthworm reproduction after applying HOCl. The results showed that HOCl application could reduce NH3 by 40% and R-NH2 by 80%, and increase the earthworm population size and total weight by up to 29% and 92%, respectively, compared to the control group. These results suggest that HOCl application is potentially an efficient method to control the odor and to boost earthworm reproduction and thus facilitate vermicomposting for improved food waste treatment and environmental quality.","pmid":"31856257","doi":"10.1371/journal.pone.0226229","url":"https://pubmed.ncbi.nlm.nih.gov/31856257/"},{"id":1152,"title":"Hypotonic, Acidic Oxidizing Solution Containing Hypochlorous Acid (HClO) as a Potential Treatment of Hailey-Hailey Disease.","authors":"Cialfi, Samantha; Calabro, Salvatore; Franchitto, Matteo; Zonfrilli, Azzurra; Screpanti, Isabella; Talora, Claudio","year":2019,"date":"2019 Dec 4","journal":"Molecules (Basel, Switzerland)","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Hailey-Hailey disease (HHD) is a rare, chronic and recurrent blistering disorder, characterized by erosions occurring primarily in intertriginous regions and histologically by suprabasal acantholysis. Mutation of the Golgi Ca(2+)-ATPase ATP2C1 has been identified as having a causative role in Hailey-Hailey disease. HHD-derived keratinocytes have increased oxidative-stress that is associated with impaired proliferation and differentiation. Additionally, HHD is characterized by skin lesions that do not heal and by recurrent skin infections, indicating that HHD keratinocytes might not respond well to challenges such as wounding or infection. Hypochlorous acid has been demonstrated in vitro and in vivo to possess properties that rescue both oxidative stress and altered wound repair process. Thus, we investigated the potential effects of a stabilized form of hypochlorous acid (APR-TD012) in an in vitro model of HHD. We found that treatment of ATP2C1-defective keratinocytes with APR-TD012 contributed to upregulation of Nrf2 (nuclear factor (erythroid-derived 2)-like 2). Additionally, APR TD012-treatment restored the defective proliferative capability of siATP2C1-treated keratinocytes. We also found that the APR-TD012 treatment might support wound healing process, due to its ability to modulate the expression of wound healing associated cytokines. These observations suggested that the APR-TD012 might be a potential therapeutic agent for HHD-lesions.","pmid":"31817098","doi":"10.3390/molecules24244427","url":"https://pubmed.ncbi.nlm.nih.gov/31817098/"},{"id":1165,"title":"Carbon Dots as Fluorescent/Colorimetric Probes for Real-Time Detection of Hypochlorite and Ascorbic Acid in Cells and Body Fluid.","authors":"Wei, Zhenni; Li, Huiqing; Liu, Suibo; Wang, Wei; Chen, Hongli; Xiao, Lehui; Ren, Cuiling; Chen, Xingguo","year":2019,"date":"2019 Dec 17","journal":"Analytical chemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorite (ClO(-)) and ascorbic acid (AA) are reported to have a high correlation with oxidative stress and related diseases, so it is necessary and critical to develop sensitive and fast response sensors to investigate the dynamical variation of these redox substances, especially those sensors which can detect ClO(-) and AA in real time in two manners. However, it is still an unmet challenge for now. Herein, novel carbon dots (RD-CDs) which can respond to ClO(-) and AA rapidly, reversibly, and dynamically by fluorescence and colorimetry were synthesized. In the fluorescence manner, the constructed nanosensor possessed high selectivity toward ClO(-) in the range of 0.1-100 μM with a detection limit of 83 nM, and can be selectively recovered by AA. It endows this sensor with good capacity as a fluorescent probe for dynamic detection of ClO(-) and AA in living cells, which can be monitored by a fluorescence microscope. In the colorimetric manner, ClO(-) and AA can be detected by UV-vis in the range of 5-200 μM and 1-30 μM, respectively. The concentrations of ClO(-) and AA in humor can be measured by RD-CDs in both fluorescence and colorimetric mode. The results above-mentioned demonstrate its great potential in biosensing.","pmid":"31756070","doi":"10.1021/acs.analchem.9b03272","url":"https://pubmed.ncbi.nlm.nih.gov/31756070/"},{"id":1167,"title":"Metabolic Activation of Tofacitinib Mediated by Myeloperoxidase in Vitro.","authors":"Guo, Xiucai; Jia, Yudi; Han, Lingling; Zhao, Yanhong; Li, Wei; Zhang, Zhengyu; Peng, Ying; Zheng, Jiang","year":2019,"date":"2019 Dec 16","journal":"Chemical research in toxicology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Tofacitinib (TFT) is used for the treatment of moderately and severely active rheumatoid arthritis. Unfortunately, TFT was reported to induce leukopenia, and the underlying mechanisms remain unclear. The present study demonstrated that TFT was oxidized to a chemically reactive nitrenium ion by myeloperoxidase (MPO) occurring in neutrophils. The electrophilic ion showed chemical reactivity toward N-acetyl-cysteine (NAC) to produce two TFT-NAC conjugates (M1 and M2) in incubation of TFT with leucocytes in the presence of NAC. The generation of the nitrenium ion was verified by HClO-mediated oxidation of TFT. In addition, the nitrenium ion was found to react with sulfhydryl groups of cysteine residues of cellular protein in leucocytes after exposure to TFT. The study facilitates the understanding of the mechanisms of TFT toxic action.","pmid":"31725283","doi":"10.1021/acs.chemrestox.9b00280","url":"https://pubmed.ncbi.nlm.nih.gov/31725283/"},{"id":1173,"title":"Luminescent metal organic frameworks with recognition sites for detection of hypochlorite through energy transfer.","authors":"Guo, Lan; Liu, Yuan; Qu, Fengli; Liu, Zhe; Kong, Rongmei; Chen, Guang; Fan, Wenjing; Xia, Lian","year":2019,"date":"2019 Nov 4","journal":"Mikrochimica acta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"A luminescent metal organic framework (LMOF) of type UiO-66-NH(2) was chosen for specific and sensitive detection of trace levels of hypochlorite. Hypochlorite causes the quenching of the blue fluorescence of nano-UiO-66-NH(2) (with excitation/emission maxima at 325/430 nm), and this finding forms the basis for a fluorometric assay for hypochlorite. The method overcomes disadvantages of conventional redox-probes which are interfered by oxidants with oxidation capability stronger than that of hypochlorite. Compared with other fluorescent probes for sensing hypochlorite, UiO-66-NH(2) has a comparable detection limit of 0.3 μmol L(-1) and a broad linearity relationship in the range of 1-8 μmol L(-1). The probe was successfully applied to the detection of hypochlorite in complex water samples and living Hela cells. Graphical abstract Schematic representation of hypochlorite induced quenching of the blue fluorescence of nano-UiO-66-NH(2) (with excitation/emission maxima at 325/430 nm) through energy transfer. It overcomes disadvantages of conventional redox-probes which are interfered by oxidants with oxidation capability stronger than that of hypochlorite.","pmid":"31686245","doi":"10.1007/s00604-019-3806-x","url":"https://pubmed.ncbi.nlm.nih.gov/31686245/"},{"id":1176,"title":"Comparative study of Cl,N-Cdots and N-Cdots and application for trinitrophenol and ClO(-) sensor and cell-imaging.","authors":"Wang, Huiping; Zhang, Li; Guo, Xueqing; Dong, Wenjuan; Wang, Ruiping; Shuang, Shaomin; Gong, Xiaojuan; Dong, Chuan","year":2019,"date":"2019 Dec 24","journal":"Analytica chimica acta","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"To understand the effect of Cl doping in carbon dots, nitrogen-doped carbon dots (N-Cdots) and nitrogen and chlorine dual-doped carbon dots (Cl,N-Cdots) were fabricated by high-temperature carbonization and low-temperature concentrated acid (HCl) acidification of dried shaddock peel, respectively. The quantum yield of Cl,N-Cdots is about four times of that of N-Cdots and the size of Cl,N-Cdots is smaller than that of N-Cdots. Furthermore, since trinitrophenol (PA) and ClO(-) could effectively quench the fluorescence of Cl,N-Cdots, the fluorescence sensors for determining PA and ClO(-) was constructed, respectively. The linear range of PA and ClO(-) are 0.9-90 μM and 3.24-216 μM with the limit of detection of 37.1 nM and 2.88 μM, respectively. The proposed sensor was used to detect PA in Taiyuan tap water, Wutai tap water, Wutai rain water and Wutai river water samples with encouraging results. The as-constructed sensor was also used to detect ClO(-) in Taiyuan tap water and commercial disinfectants. Last but not least, Cl,N-Cdots was employed as an agent for A549 and HeLa cell-imaging, possessing optimal imaging effect and ultra-low cytotoxicity. Our results suggested that Cl,N-Cdots has promising applications in sensing, water monitoring, commodity supervision and cell-imaging.","pmid":"31679577","doi":"10.1016/j.aca.2019.09.019","url":"https://pubmed.ncbi.nlm.nih.gov/31679577/"},{"id":1177,"title":"Electrochemically-Activated Water Presents Bactericidal Effect Against Salmonella Heidelberg Isolated from Poultry Origin.","authors":"Wilsmann, Daiane Elisa; Carvalho, Daiane; Zottis Chitolina, Gabriela; Apellanis Borges, Karen; Quedi Furian, Thales; Carvalho Martins, Abrahão; Webber, Bruna; Pinheiro do Nascimento, Vladimir","year":2020,"date":"2020 Mar","journal":"Foodborne pathogens and disease","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Salmonella spp. are among the most important pathogens in poultry farming, and Salmonella Heidelberg (SH) is one of the most frequent serotypes isolated in Brazil. SH has a zoonotic potential and stands out as a pathogen that is difficult to eliminate from the poultry chain due to its resistance to disinfectants. One alternative to traditional disinfectants is the electrochemically-activated water (ECA), a bactericidal compound produced from the electrolysis of salt and water. ECA generators produce a compound that consists of free chlorine, hypochlorous acid, and other free radicals. This alternative control method is safe for human health and reduces environmental contamination. The present study aimed at evaluating the efficacy of ECA against 30 SH isolates from poultry origin in scenarios that simulated the chiller environment (4°C, 5 and 50 parts per million [ppm], 5 and 40 min of exposure) and the cleaning and disinfection process (25°C, 200 ppm, 5 and 10 min of exposure). In the quantitative test, SH was susceptible to ECA. The mean bacterial counts decreased significantly compared to the control group, especially at 200 ppm. At this concentration, ECA inhibited the growth of almost 87% of the Salmonella strains, and the results showed a significant decrease in the mean bacterial counts for both exposure times (5 and 10 min). These findings demonstrate that ECA is effective against SH in vitro and it is a possible alternative to disinfection in the poultry industry for the control of this pathogen. However, in situ tests in the food industry are needed.","pmid":"31647339","doi":"10.1089/fpd.2019.2682","url":"https://pubmed.ncbi.nlm.nih.gov/31647339/"},{"id":1180,"title":"A real-time-based in vitro assessment of the oxidative antimicrobial mechanisms of the myeloperoxidase-hydrogen peroxide-halide system.","authors":"Atosuo, Janne; Suominen, Eetu","year":2019,"date":"2019 Dec","journal":"Molecular immunology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Mammals have evolved a special cellular mechanism for killing invading microbes, which is called the phagocytosis. Neutrophils are the first phagocytosing cells that migrate into the site of infection. In these cells, hypochlorite (HOCl) and other hypohalites, generated in the myeloperoxidase (MPO)-hydrogen peroxide (H(2)O(2))-halide system is primarily responsible for oxidative killing. Here, we present a method for assessing these oxidative mechanisms in an in vitro cell-free system in a kinetical real-time-based manner by utilizing a bioluminescent bacterial probe called Escherichia coli-lux. The E. coli-lux method provides a practical tool for assessing the effects of various elementary factors in the MPO-H(2)O(2)-halide system. Due to the reported versatile intracellular pH and halide concentration during the formation of the phagolysosome and respiratory burst, the antimicrobial activity of the MPO-H(2)O(2)-halide system undergoes extensive alterations. Here, we show that at a physiological pH or lower, the antimicrobial activity of MPO is high, and the system effectively enhances the H(2)O(2)-dependent oxidative killing of E. coli by chlorination. The HOCl formed in this reaction is a prominent microbe killer. During the respiratory burst, there is a shift to a more alkaline environment. At pH 7.8, the chlorinating activity of MPO was shown to be absent, and the activity of the HOCl decreased. At this higher pH, the activity of H(2)O(2) is enhanced and high enough to kill E. coli without the participation of MPO, and the lowered chloride concentration seemed still to enhance the H(2)O(2)-dependent killing capacity.","pmid":"31593870","doi":"10.1016/j.molimm.2019.09.017","url":"https://pubmed.ncbi.nlm.nih.gov/31593870/"},{"id":1184,"title":"Inactivation of Rhizoctonia solani in fertigation water using regenerative in situ electrochemical hypochlorination.","authors":"Lévesque, Serge; Graham, Thomas; Bejan, Dorin; Lawson, Jamie; Zhang, Ping; Dixon, Mike","year":2019,"date":"2019 Oct 2","journal":"Scientific reports","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The capture and re-use of greenhouse fertigation water is an efficient use of fertilizer and limited water resources, although the practice is not without risk. Plant pathogens and chemical contaminants can build up over successive capture and re-use cycles; if not properly managed they can lead to reduced productivity or crop loss. There are numerous established and emerging water treatment technologies available to treat fertigation water. Electrochemical processes are emerging as effective means for controlling pathogens via in situ regenerative hypochlorination; a process that is demonstrated here to achieve pathogen control in fertigation solutions without leading to the accumulation of potentially phytotoxic free chlorine residuals associated with other chlorination processes. An electrochemical flow cell (EFC) outfitted with ruthenium dioxide (RuO(2)) dimensionally stable anodes (DSA) was characterized and evaluated for free chlorine production and Rhizoctonia solani inactivation in both irrigation and fertigation solutions. Pathogen inactivation was achieved at low current densities and short residence or cell contact times. Effluent free chlorine concentrations were significantly lower than commonly reported phytotoxic threshold values (approximately 2.5 mg/L) when fertilizer (containing ammonium) was present in the test solution; an effect attributable to reactions associated with breakpoint chlorination, including chloramine formation, as well as the presence of other oxidizable compounds in the fertilizer. Chloride concentrations were stable under the test conditions suggesting that the EFC was operating as a regenerative in situ electrochemical hypochlorination system. No significant changes to macronutrient concentrations were found following passage through the EFC.","pmid":"31578375","doi":"10.1038/s41598-019-50600-7","url":"https://pubmed.ncbi.nlm.nih.gov/31578375/"},{"id":1186,"title":"Iodide modulates protein damage induced by the inflammation-associated heme enzyme myeloperoxidase.","authors":"Gamon, Luke F; Dieterich, Simon; Ignasiak, Marta T; Schrameyer, Verena; Davies, Michael J","year":2020,"date":"2020 Jan","journal":"Redox biology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Iodide ions (I(-)) are an essential dietary mineral, and crucial for mental and physical development, fertility and thyroid function. I(-) is also a high affinity substrate for the heme enzyme myeloperoxidase (MPO), which is involved in bacterial cell killing during the immune response, and also host tissue damage during inflammation. In the presence of H(2)O(2) and Cl(-), MPO generates the powerful oxidant hypochlorous acid (HOCl), with excessive formation of this species linked to multiple inflammatory diseases. In this study, we have examined the hypothesis that elevated levels of I(-) would decrease HOCl formation and thereby protein damage induced by a MPO/Cl(-)/H(2)O(2) system, by acting as a competitive substrate. The presence of increasing I(-) concentrations (0.1-10 μM; i.e. within the range readily achievable by oral supplementation in humans), decreased damage to both model proteins and extracellular matrix components as assessed by gross structural changes (SDS-PAGE), antibody recognition of parent and modified protein epitopes (ELISA), and quantification of both parent amino acid loss (UPLC) and formation of the HOCl-biomarker 3-chlorotyrosine (LC-MS) (reduced by ca. 50% at 10 μM I(-)). Elevated levels of I(-) ( > 1 μM) also protected against functional changes as assessed by a decreased loss of adhesion (eg. 40% vs. < 22% with >1 μM I(-)) of primary human coronary artery endothelial cells (HCAECs), to MPO-modified human plasma fibronectin. These data indicate that low micromolar concentrations of I(-), which can be readily achieved in humans and are readily tolerated, may afford protection against cell and tissue damage induced by MPO.","pmid":"31568923","doi":"10.1016/j.redox.2019.101331","url":"https://pubmed.ncbi.nlm.nih.gov/31568923/"},{"id":1188,"title":"Decontamination of aerosolised bacteria from a pig farm environment using a pH neutral electrochemically activated solution (Ecas4 anolyte).","authors":"Tenzin, Sangay; Ogunniyi, Abiodun David; Khazandi, Manouchehr; Ferro, Sergio; Bartsch, Jonathon; Crabb, Simon; Abraham, Sam; Deo, Permal; Trott, Darren J","year":2019,"date":"2019","journal":"PloS one","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"An electrochemically activated solution (ECAS), generated by electrolysis of a dilute sodium chloride solution in a four-chamber electrolytic cell (Ecas4), was tested as a sanitising aerosol in eliminating bacteria from the environment of a weaning room vacated 24-48h earlier, at a continuous flow pig farm. An ultrasonic humidifier was used to fill the environment with a fog (droplets with diameters of 1-5 μm) containing 0.25 ppm of hypochlorous acid. The weaning room was fogged for 3 min at 30 min intervals during five hours of aerosol disinfection. An innovative sample treatment with propidium monoazide dye in conjunction with cyclonic air sampling was optimised and adapted for discerning live/dead bacteria in subsequent molecular quantification steps. Without fogging, total bacterial load ranged from 5.06 ± 0.04 to 5.75 ± 0.04 Log10 CFU/m3. After the first hour of fogging, a 78% total bacterial reduction was observed, which further increased to > 97% after the second hour, > 99.4% after the third and 99.8% after the fourth hour, finally resulting in a 99.99% reduction from the farm environment over five hours. Unlike the current formaldehyde spray disinfection protocol, which requires a long empty period because of its hazardous properties, this economically viable and environmentally friendly disinfection protocol may significantly lower downtime. Moreover, ECAS fogging can be easily adapted to a variety of applications, including the elimination of pathogens from livestock farm air environment for disease prevention, as well as decontamination after disease outbreaks.","pmid":"31553747","doi":"10.1371/journal.pone.0222765","url":"https://pubmed.ncbi.nlm.nih.gov/31553747/"},{"id":1192,"title":"Enhanced thallium(I) removal from wastewater using hypochlorite oxidation coupled with magnetite-based biochar adsorption.","authors":"Li, Huosheng; Xiong, Jingfang; Zhang, Gaosheng; Liang, Aiping; Long, Jianyou; Xiao, Tangfu; Chen, Yongheng; Zhang, Ping; Liao, Dandan; Lin, Lianhua; Zhang, Hongguo","year":2020,"date":"2020 Jan 1","journal":"The Science of the total environment","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The development of efficient and regenerable adsorbent coupled with advanced oxidation for enhanced thallium (Tl) removal has been a recent focus on wastewater treatment. In this study, a magnetite-based biochar derived from watermelon rinds was synthesized and used as a sustainable adsorbent and catalyst for hypochlorite oxidation and removal of Tl(I) from wastewater. The addition of hypochlorite substantially enhanced the Tl(I) removal under normal pH range (6-9). Maximum Tl adsorption capacity of 1123 mg/g was achieved, which is 12.3% higher than the highest value previously reported. The magnetic biochar can be regenerated using 0.1 mol/L HNO(3) solution for elution in only 5 min, with a Tl desorption efficiency of 78.9%. The Tl removal efficiency was constantly higher than 98.5% during five consecutive recycle tests, indicating the effective reuse performance of the adsorbent. Oxidation, surface precipitation, pore retention and surface complexation were the main mechanisms for Tl(I) removal. The re-dissolution of Tl compounds and ion exchange of Tl cations with proton were the main mechanisms for adsorbent regeneration. Given the fast oxidation rate, high adsorption capacity, steady reusability and facile separability, this magnetic biochar-hypochlorite technique is a promising means for Tl(I) removal from wastewater. The catalytic hypochlorite oxidation induced by the magnetic biochar has also great potential to the effective removal of other pollutants.","pmid":"31494421","doi":"10.1016/j.scitotenv.2019.134166","url":"https://pubmed.ncbi.nlm.nih.gov/31494421/"},{"id":1194,"title":"A twist six-membered rhodamine-based fluorescent probe for hypochlorite detection in water and lysosomes of living cells.","authors":"Wang, Zechen; Zhang, Qinghao; Liu, Junwen; Sui, Ran; Li, Yahui; Li, Yue; Zhang, Xinfu; Yu, Haibo; Jing, Kui; Zhang, Mingyan; Xiao, Yi","year":2019,"date":"2019 Nov 15","journal":"Analytica chimica acta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"A novel six-membered rhodamine-based fluorescent probe (6G-ClO) was developed from 2-formyl rhodamine (6G-CHO) and used for hypochlorite detection in water and HUVEC cells. Different from planar penta cycle of rhodamine spirolactam, there was a twist six-membered spirocyclic hydrazone in 6G-ClO optimized by Gaussian software at DFT/B3LYP/6-31G(d) level. The high selectivity, high sensitivity and fast response of 6G-ClO towards ClO(-) would be attributed to the twist six-membered spirocycle. Test-strip prepared with 6G-ClO was successfully used to semi-quantitatively indicate the concentration of ClO(-) in water. 6G-ClO can also quantitatively detect the concentration of ClO(-) in tap water and swimming pool water. The detection limit of 6G-ClO was as low as 12 nM. The co-localization staining of HUVEC cells further verified that 6G-ClO could specifically accumulate in lysosomes and capture exogenous/endogenous ClO(-) in living lysosomes. 6G-ClO would be a practical probe for real-time monitoring of ClO(-) in the biological and real water samples.","pmid":"31472700","doi":"10.1016/j.aca.2019.07.046","url":"https://pubmed.ncbi.nlm.nih.gov/31472700/"},{"id":1199,"title":"The formation of N-chloramines with proteinogenic amino acids.","authors":"Szabó, Mária; Simon, Fruzsina; Fábián, István","year":2019,"date":"2019 Nov 15","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"In this study, the formation of 17 N-chloramines from proteinogenic amino acids and HOCl was studied by direct kinetic method in the pH = 3-13 range. Thus, the uncertainties associated with the indirect methods used in some of the previous studies were eliminated. Each reaction proceeds according to an overall second order kinetics: v = - k [HOCl][R-NH(2)] and the rate constants are several times 10(7) M(-1)s(-1). A very slight correlation was found between the lgk and the pK(AA) of the amino acids. The results make possible to predict the reactivity order of the amino acids toward HOCl under various conditions. A comparison of the parameters of activation indicates that the presence of a bulky substituent on the side chain close to the α-carbon atom decreases the strength of bonding between the reactants and make the structure more diffuse in the transition state. The chlorination of histidine proceeds via two pH dependent paths presumably leading to the formation of N-chloramine and a side chain chlorinated product. The latter compound may be involved in fast subsequent trans-chlorination reactions. The results presented here resolve earlier discrepancies in the literature and are relevant in chlorination water treatment technologies as well as in the interpretation of in vivo processes involving the formation of N-chloro amino acids in a wide pH range.","pmid":"31445310","doi":"10.1016/j.watres.2019.114994","url":"https://pubmed.ncbi.nlm.nih.gov/31445310/"},{"id":1203,"title":"Neutrophils as Sentinel Cells of the Immune System: A Role of the MPO-halide-system in Innate and Adaptive Immunity.","authors":"Marcinkiewicz, Janusz; Walczewska, Maria","year":2020,"date":"2020","journal":"Current medicinal chemistry","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"For decades, neutrophils were generally regarded as the cells of innate immunity with proinflammatory and phagocytic properties involved in a dual activity, beneficial (antimicrobial) and detrimental (tissue damage). Importantly, until the discovery of toll-like receptors (TLRs), a role of neutrophils in adaptive immunity was limited to the effector stage of humoral response and phagocytosis of opsonized antigens. Moreover, in common opinion, neutrophils, as well as the entire innate immune system, were not functionally associated with adaptive immunity. At the time we demonstrated protein chlorination by HOCl, the major product of neutrophil MPO-halide system enhances protein immunogenicity. Based on this discovery, we proposed, as the first, a new role for neutrophils as APC-accessory cells involved in the induction stage of adaptive immunity. Thereafter, we developed our theory concerning the role of neutrophils as the cells which link innate and adaptive immunity. We proposed that protein modification by HOCl may act as a neutrophildependent molecular tagging system, by which sentinel dendritic cells can faster recognise pathogen- derived antigens. Contemporaneously, it was demonstrated that taurine, the most abundant free amino acid in neutrophil cytosol and the major scavenger of HOCl, is a part of the oxidantantioxidant network and is responsible for the regulation and termination of acute inflammation. Moreover, it has been described, that taurine chloramine (TauCl), the physiological products of the reaction of HOCl with taurine, show anti-microbial and anti-inflammatory properties. In this review, the role of HOCl, taurine and TauCl in innate and adaptive immunity will be discussed.","pmid":"31424363","doi":"10.2174/0929867326666190819123300","url":"https://pubmed.ncbi.nlm.nih.gov/31424363/"},{"id":1210,"title":"Exposure of Pseudomonas aeruginosa to bactericidal hypochlorous acid during neutrophil phagocytosis is compromised in cystic fibrosis.","authors":"Dickerhof, Nina; Isles, Vivienne; Pattemore, Philip; Hampton, Mark B; Kettle, Anthony J","year":2019,"date":"2019 Sep 6","journal":"The Journal of biological chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase is a major neutrophil antimicrobial protein, but its role in immunity is often overlooked because individuals deficient in this enzyme are usually in good health. Within neutrophil phagosomes, myeloperoxidase uses superoxide generated by the NADPH oxidase to oxidize chloride to the potent bactericidal oxidant hypochlorous acid (HOCl). In this study, using phagocytosis assays and LC-MS analyses, we monitored GSH oxidation in Pseudomonas aeruginosa to gauge their exposure to HOCl inside phagosomes. Doses of reagent HOCl that killed most of the bacteria oxidized half the cells' GSH, producing mainly glutathione disulfide (GSSG) and other low-molecular-weight disulfides. Glutathione sulfonamide (GSA), a HOCl-specific product, was also formed. When neutrophils phagocytosed P. aeruginosa, half of the bacterial GSH was lost. Bacterial GSA production indicated that HOCl had reacted with the bacterial cells, oxidized their GSH, and was sufficient to be solely responsible for bacterial killing. Inhibition of NADPH oxidase and myeloperoxidase lowered GSA formation in the bacterial cells, but the bacteria were still killed, presumably by compensatory nonoxidative mechanisms. Of note, bacterial GSA formation in neutrophils from patients with cystic fibrosis (CF) was normal during early phagocytosis, but it was diminished at later time points, which was mirrored by a small decrease in bacterial killing. In conclusion, myeloperoxidase generates sufficient HOCl within neutrophil phagosomes to kill ingested bacteria. The unusual kinetics of phagosomal HOCl production in CF neutrophils confirm a role for the cystic fibrosis transmembrane conductance regulator in maintaining HOCl production in neutrophil phagosomes.","pmid":"31341024","doi":"10.1074/jbc.RA119.009934","url":"https://pubmed.ncbi.nlm.nih.gov/31341024/"},{"id":1211,"title":"Inactivation of Shiga toxin-producing Escherichia coli in fresh beef by electrolytically-generated hypochlorous acid, peroxyacetic acid, lactic acid and caprylic acid.","authors":"Cap, Mariana; Vaudagna, Sergio; Mozgovoj, Marina; Soteras, Trinidad; Sucari, Adriana; Signorini, Marcelo; Leotta, Gerardo","year":2019,"date":"2019 Nov","journal":"Meat science","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Several studies have been conducted to verify the decontamination potential of electrolytically-generated hypochlorous acid, peroxyacetic acid, lactic acid and caprylic acid against Shiga toxin-producing Escherichia coli (STEC) in beef products. However, there is no consensus regarding their effectiveness. The aim of this study was to compare these four treatments under the same conditions and establish a ranking according to their effectiveness to inactivate STEC in fresh beef. Samples were inoculated with two levels of inoculum and rinsed for 15 s in 100 mL of antimicrobial solution treatment. Caprylic acid was the most effective treatment, followed by lactic acid and peroxyacetic acid. Electrolytically-generated hypochlorous acid had no effect. Sensory analysis showed no significant differences either in flavor or in color between samples treated with caprylic acid and reference samples. Caprylic acid appears to be an effective and viable alternative to conventional interventions frequently used for meat product decontamination.","pmid":"31323451","doi":"10.1016/j.meatsci.2019.107886","url":"https://pubmed.ncbi.nlm.nih.gov/31323451/"},{"id":1216,"title":"N-chlorination mediates protective and immunomodulatory effects of oxidized human plasma proteins.","authors":"Ulfig, Agnes; Schulz, Anton V; Müller, Alexandra; Lupilov, Natalie; Leichert, Lars I","year":2019,"date":"2019 Jul 12","journal":"eLife","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCl), a powerful antimicrobial oxidant, is produced by neutrophils to fight infections. Here, we show that N-chlorination, induced by HOCl concentrations encountered at sites of inflammation, converts blood plasma proteins into chaperone-like holdases that protect other proteins from aggregation. This chaperone-like conversion was reversible by antioxidants and was abrogated by prior methylation of basic amino acids. Furthermore, reversible N-chlorination of basic amino acid side chains is the major factor that converts plasma proteins into efficient activators of immune cells. Finally, HOCl-modified serum albumin was found to act as a pro-survival molecule that protects neutrophils from cell death induced by highly immunogenic foreign antigens. We propose that activation and enhanced persistence of neutrophils mediated by HOCl-modified plasma proteins, resulting in the increased and prolonged generation of ROS, including HOCl, constitutes a potentially detrimental positive feedback loop that can only be attenuated through the reversible nature of the modification involved.","pmid":"31298656","doi":"10.7554/eLife.47395","url":"https://pubmed.ncbi.nlm.nih.gov/31298656/"},{"id":1219,"title":"The myeloperoxidase product, hypochlorous acid, reduces thrombus formation under flow and attenuates clot retraction and fibrinolysis in human blood.","authors":"Misztal, Tomasz; Golaszewska, Agata; Tomasiak-Lozowska, Maria Magdalena; Iwanicka, Marta; Marcinczyk, Natalia; Leszczynska, Agnieszka; Chabielska, Ewa; Rusak, Tomasz","year":2019,"date":"2019 Sep","journal":"Free radical biology & medicine","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Hypochlorite (HOCl), a strong oxidant and antimicrobial agent, has been proposed to be associated with hemostatic abnormalities during inflammatory response. However, its complex impact on hemostasis is not completely understood. In this report we studied the effect of clinically relevant (micromolar) HOCl concentrations on thrombus formation under flow, kinetics of platelet-fibrin clot formation, its architecture, retraction, and lysis. We found that HOCl (up to 500 µM) did not affect kinetics of coagulation measured in whole blood. HOCl (500-1000 µM) markedly diminished thrombus formation under flow. Clot retraction rate was reduced by HOCl dose-dependently (50-500 µM). HOCl (125-500 µM) inhibited fibrinolysis in whole blood and in platelet-depleted plasma, dose-dependently. Activity of plasmin was reduced by HOCl at concentrations started from 500 µM. HOCl (up to 500 µM) did not reduce plasminogen binding to fibrin under flow. HOCl (125-500 µM) modulated architecture of fibrin- and platelet-fibrin clots towards structures made of thin and densely packed fibers. Exposure of pure fibrinogen to HOCl (10-1000 µM) resulted in formation of dityrosine and was associated with altered fibrin structure derived from such modified fibrinogen. HOCl-altered fibrin net structure was not related with modulation of platelet procoagulant response, thrombin generation, and factor XIII activity. We conclude that, in human blood, clinically relevant HOCl concentrations may inhibit thrombus formation under flow, clot retraction and fibrinolysis. Fibrinolysis and clot retraction seem to be the most sensitive to HOCl-evoked inhibition. HOCl-modified fibrinogen and altered clot structure associated with it are likely to be primary sources of attenuated fibrinolysis.","pmid":"31279970","doi":"10.1016/j.freeradbiomed.2019.07.003","url":"https://pubmed.ncbi.nlm.nih.gov/31279970/"},{"id":1221,"title":"Deterioration Mechanism of a Tertiary Polyamide Reverse Osmosis Membrane by Hypochlorite.","authors":"Hashiba, Koki; Nakai, Satoshi; Ohno, Masaki; Nishijima, Wataru; Gotoh, Takehiko; Iizawa, Takashi","year":2019,"date":"2019 Aug 6","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"A tertiary polyamide membrane was synthesized using N,N'-dimethyl-m-phenylenediamine. The durability of this membrane to chlorination by hypochlorite treatment followed by sodium hydroxide treatment was examined, and then deterioration mechanisms were proposed. The tertiary polyamide membrane demonstrated better durability to free chlorine than a conventional secondary polyamide one; however, the former was deteriorated by hypochlorite for 24 h at 2000 ppm of free chlorine below pH 7.5. The salt rejection and permeation performance of the membrane were almost unchanged, and the least chlorination of the active layer occurred during hypochlorite treatment at pH 10. These results indicated that hypochlorous acid rather than hypochlorite ion was the free chlorine species that induced membrane deterioration. The deterioration became severe as chlorination progressed, resulting in collapse of the active layer below pH 7.5. Chlorination and hydrolysis of the model tertiary amide N-methylbenzanilide and Fourier transfer infrared spectroscopy of a deteriorated membrane showed that chlorination of the tertiary polyamide occurred via direct chlorination of the benzene bound to the amidic nitrogen. Silver ion probing of the deteriorated membrane revealed that amide bond scission occurred in the active layer, which might be related to the electron deficiency of the amidic nitrogen caused by chlorination of its benzene ring.","pmid":"31276395","doi":"10.1021/acs.est.9b00663","url":"https://pubmed.ncbi.nlm.nih.gov/31276395/"},{"id":1223,"title":"Analysis of protein chlorination by mass spectrometry.","authors":"Nybo, Tina; Davies, Michael J; Rogowska-Wrzesinska, Adelina","year":2019,"date":"2019 Sep","journal":"Redox biology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Chlorination of tyrosine is a commonly known effect/consequence of myeloperoxidase activity at sites of inflammation, and detection of 3-chlorotyrosine has been used as biomarker for inflammatory diseases. However, few studies have addressed site specific chlorination in proteins, and no methods for large scale chloroproteomics studies have yet been published. In this study, we present an optimized mass spectrometry based protocol to identify and quantify chlorinated peptides from single proteins modified by HOCl (100 and 500 μM, within estimated pathophysiological levels), at a high level of sensitivity and accuracy. Particular emphasis was placed on 1) sensitive and precise detection of modification sites, 2) the avoidance of loss or artefactual creation of modifications, 3) accurate quantification of peptide abundance and reduction of missing values problem, 4) monitoring the dynamics of modification in samples exposed to different oxidant concentrations and 5) development of guidelines for verification of chlorination sites assignment. A combination of an optimised sample preparation protocol, and improved data analysis approaches have allowed identification of 33 and 15 chlorination sites in laminin and fibronectin, respectively, reported in previous manuscripts [1,2]. The method was subsequently tested on murine basement membrane extract, which contains high levels of laminin in a complex mixture. Here, 10 of the major chlorination sites in laminin were recapitulated, highlighting the utility of the method in detecting damage in complex samples.","pmid":"31181457","doi":"10.1016/j.redox.2019.101236","url":"https://pubmed.ncbi.nlm.nih.gov/31181457/"},{"id":1229,"title":"Catalase prevents myeloperoxidase self-destruction in response to oxidative stress.","authors":"Ali, Iyad; Khan, Sana N; Chatzicharalampous, Charalampos; Bai, David; Abu-Soud, Husam M","year":2019,"date":"2019 Aug","journal":"Journal of inorganic biochemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Catalase (CAT) and myeloperoxiase (MPO) are heme-containing enzymes that have attracted attention for their role in the etiology of numerous respiratory disorders such as cystic fibrosis, bronchial asthma, and acute hypoxemic respiratory failure. However, information regarding the interrelationship and competition between the two enzymes, free iron accumulation, and decreased levels of non-enzymatic antioxidants at sites of inflammation is still lacking. Myeloperoxidase catalyzes the generation of hypochlorous acid (HOCl) from the reaction of hydrogen peroxide (H(2)O(2)) and chloride (Cl(-)). Self-generated HOCl has recently been proposed to auto-inhibit MPO through a mechanism that involves MPO heme destruction. Here, we investigate the interplay of MPO, HOCl, and CAT during catalysis, and explore the crucial role of MPO inhibitors and HOCl scavengers in protecting the catalytic site from protein modification of both enzymes against oxidative damage mediated by HOCl. We showed that CAT not only competes with MPO for H(2)O(2) but also scavenges HOCl. The protective role provided by CAT versus the damaging effect provided by HOCl depends in part on the ratio between MPO/CAT and the affinity of the enzymes towards H(2)O(2) versus HOCl. The severity of such damaging effects mainly depends on the ratio of HOCl to enzyme heme content. In addition to its effect in mediating protein modification and aggregation, HOCl oxidatively destroys the catalytic sites of the enzymes, which contain porphyrin rings and iron. Thus, modulation of MPO/CAT activities may be a fundamental feature of catalysis, and functions to down-regulate HOCl synthesis and prevent hemoprotein heme destruction and/or protein modification.","pmid":"31103890","doi":"10.1016/j.jinorgbio.2019.110706","url":"https://pubmed.ncbi.nlm.nih.gov/31103890/"},{"id":1240,"title":"Fluorescence measurements of peroxynitrite/peroxynitrous acid in cold air plasma treated aqueous solutions.","authors":"Tarabová, Barbora; Lukeš, Petr; Hammer, Malte U; Jablonowski, Helena; von Woedtke, Thomas; Reuter, Stephan; Machala, Zdenko","year":2019,"date":"2019 Apr 24","journal":"Physical chemistry chemical physics : PCCP","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Qualitative detection of peroxynitrite/peroxynitrous acid (ONOO-/ONOOH) as one of the key bactericidal agents produced in cold air plasma activated aqueous solutions is presented. We examined the use of the 2,7-dichlorodihydrofluorescein diacetate (H2DCFDA) fluorescent dye to detect ONOO-/ONOOH in plasma activated non-buffered water (PAW) or buffered solution (PAPB) generated by DC-driven self-pulsed transient spark discharge at atmospheric pressure in ambient air. The diagnostic selectivity of H2DCFDA to reactive oxygen and nitrogen species (RONS) typical of plasma activated aqueous solutions was examined by using various scavengers of RONS. This cross-reactivity study showed the highest sensitivity of the H2DCFDA dye to ONOO-/ONOOH. However, besides ONOO-/ONOOH, H2DCFDA also exhibited sensitivity to hypochlorite anions/hypochlorous acid (OCl-/HOCl), showing that for a selective study it is important to have an idea about the possible constituents in the studied solutions. The sensitivity of H2DCFDA to other RONS even in much higher concentrations was negligible. The presence of nitrites (NO2-) and hydrogen peroxide (H2O2) in PAW led predominantly to the production of peroxynitrous acid with a strong fluorescence response of H2DCFDA in PAW. Plasma treatment of buffered solutions led to the weak response of H2DCFDA. The fluorescence induced in PAW decreased after scavenging individual reactants, namely NO2- and H2O2, as well as by scavenging the product of the peroxynitrite forming reaction, proving that the fluorescence response of H2DCFDA is primarily due to the formation of ONOO-/ONOOH. A chemical kinetics analysis of post-discharge processes and the pseudo-second order reaction between H2O2 and NO2- confirms formation of peroxynitrous acid in PAW with a rate in the order of tens of nM per second. The post-discharge evolution of the ONOOH formation rate was clearly correlated with the parallel detection of ONOO-/ONOOH by fluorescence spectroscopy using the H2DCFDA dye.","pmid":"30982833","doi":"10.1039/c9cp00871c","url":"https://pubmed.ncbi.nlm.nih.gov/30982833/"},{"id":1245,"title":"Inactivation of conidia from three Penicillium spp. isolated from fruit juices by conventional and alternative mild preservation technologies and disinfection treatments.","authors":"Nierop Groot, Masja; Abee, Tjakko; van Bokhorst-van de Veen, Hermien","year":2019,"date":"2019 Aug","journal":"Food microbiology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Fungi are able to grow on diverse food products and contribute to food spoilage worldwide causing food loss. Consumers prefer freshly squeezed fruit juices, however, the shelf life of these juices is limited due to outgrowth of yeast and fungi. The shelf life of pulsed electric field (PEF) treated juice can be extended from 8 days up to a few weeks before spoilage by moulds becomes apparent. Conidia produced by three Penicillium ssp. (Penicillium expansum, Penicillium buchwaldii and Penicillium bialowiezense), previously isolated from spoiled PEF treated fruit juice and smoothie, were characterized for resistance towards selected mild physical processing techniques in orange juice and toward sanitizers on surfaces. The results show that Penicillium spp. conidia are susceptible to mild heat, high pressure pasteurization (HPP), PEF, cold atmospheric plasma (CAP), UV, and chemical sanitizers chlorine dioxide and hypochlorite albeit with different susceptibility. Treatment with mild heat, HPP, PEF, or chlorine dioxide reduced conidia by more than 5 log. For hypochlorite, UV, and CAP the reduction was between 1 and 3 log. Together, this study provides data for the development of intervention strategies to eliminate spoilage mould conidia in fruit juices.","pmid":"30910081","doi":"10.1016/j.fm.2018.06.004","url":"https://pubmed.ncbi.nlm.nih.gov/30910081/"},{"id":1246,"title":"Dietary Flavonoids Scavenge Hypochlorous Acid via Chlorination on A- and C-Rings as Primary Reaction Sites: Structure and Reactivity Relationship.","authors":"Yang, Xin; Wang, Tian; Guo, Jinlong; Sun, Mingtai; Wong, Ming Wah; Huang, Dejian","year":2019,"date":"2019 Apr 17","journal":"Journal of agricultural and food chemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Dietary flavonoids are known as scavengers of reactive oxygen species such as hypochlorous acid. In spite of the abundant scavenging capacity data reported, few reports have addressed the relationship between the scavenging capacity and structures of different flavonoids. We characterized the reaction products of five flavonoids (apigenin, quercetin, naringenin, ampelopsin, and epicatechin) with hypochlorous acid and found that primary chlorination reaction occurred on the A-ring (C6 or C8) and/or C-rings but not on B-rings. Correlation of the hypochlorous acid scavenging capacity (IC(50) values) and the structural features of flavonoids revealed that the hydroxyl groups in the A-ring and B-ring can enhance the scavenging capacity, whereas the C(2)C(3) double bond has a negative impact on the HClO scavenging capacity. Combining the SAR analysis and chemical study, we proposed that the reaction mechanism between flavonoids and HClO should be an electrophilic substitution reaction. Density functional theory (DFT) results are consistent with the selectivity of chlorination on the flavonoids. Our findings highlight the importance of considering specific reactive oxygen species when measuring radical scavenging capacity of dietary antioxidants.","pmid":"30901210","doi":"10.1021/acs.jafc.8b06689","url":"https://pubmed.ncbi.nlm.nih.gov/30901210/"},{"id":1249,"title":"Construction of Its Evaluation System in Originally Designed Test-Chamber System and Sporicidal Activity of Aerosolized Hypochlorite Solution to Bacillus subtilis Spores.","authors":"Ishikawa, Shu; Ueno, Shohei; Mitsui, Mai; Matsumura, Yoshinobu; Hatsuoka, Tetsuro","year":2019,"date":"2019","journal":"Biocontrol science","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Effective spatial disinfection systems are required for human health care, public hygiene, and food and medicine manufacturing. Although some aerosolized disinfectants were already applied to its purpose, accurate evaluation systems were under constructed. In this study, the spatial sporicidal activity of aerosolized hypochlorite solution (AHS) to dormant cells, Bacillus subtilis spores, was evaluated by an originally designed chamber system. In the test-chamber, AHS was supplied and existed as micro-droplets, and environmental relative humidity (RH) could be controlled. Available chlorine (AC) exposure was also controlled with appropriate AC loading but was influenced by the acidity of AHS. Our results indicated that inactivation of spore was depend on AC exposure amount and time. On the other hand, unsaturated environmental RH markedly decreased spore inactivation. This study indicated that our test-chamber system can provide reproducible test data under a homogeneous air condition, and, thereby, that the data obtained by the chamber system should contribute to predicting the AC-required dose to disinfect a whole building.","pmid":"30880314","doi":"10.4265/bio.24.57","url":"https://pubmed.ncbi.nlm.nih.gov/30880314/"},{"id":1251,"title":"Enhanced fluorescence sensing of hypochlorous acid using serum albumin as a signal amplifier.","authors":"Zhang, Peng; Zhang, Qian; Li, Shasha; Chen, Wenhui; Guo, Xinjie; Ding, Caifeng","year":2019,"date":"2019 Feb 28","journal":"Journal of materials chemistry. B","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HOCl/ClO(-)) is well-known as a pivotal member of reactive oxygen species (ROS) and acts as a vital regulator of cell activities including cell differentiation, migration, and immune response. However, overexpressed ClO(-) may cause tissue damage; thus, significant efforts have been devoted to ClO(-) sensing at the molecular level. Herein, a mitochondria-targeting fluorescent probe for ClO(-) was developed based on oxidation by ClO(-), releasing a green emissive luminogen under physiological conditions. In particular, a \"signal amplifier\", bovine serum albumin (BSA), was utilized to promote the fluorescence response, which effectively converted the probe from a \"turn-off\" mode to a ratiometric fluorescence system. This analytical strategy reduced the limit of detection to as low as 1.5 nM and was also applicable to live cells, accompanied by significant fluorescence change from red to green with a modified signal-to-noise ratio. Moreover, the probe exhibited good performance for targeting mitochondria and monitoring endogenous ClO(-). Based on the results of this study, the well-designed probe and analytical method could be promising for intracellular ClO(-) detection.","pmid":"32255163","doi":"10.1039/c8tb03023e","url":"https://pubmed.ncbi.nlm.nih.gov/32255163/"},{"id":1252,"title":"Hypochlorous-Acid-Generating Electrochemical Scaffold for Treatment of Wound Biofilms.","authors":"Kiamco, Mia Mae; Zmuda, Hannah M; Mohamed, Abdelrhman; Call, Douglas R; Raval, Yash S; Patel, Robin; Beyenal, Haluk","year":2019,"date":"2019 Feb 25","journal":"Scientific reports","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Biofilm formation causes prolonged wound infections due to the dense biofilm structure, differential gene regulation to combat stress, and production of extracellular polymeric substances. Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa are three difficult-to-treat biofilm-forming bacteria frequently found in wound infections. This work describes a novel wound dressing in the form of an electrochemical scaffold (e-scaffold) that generates controlled, low concentrations of hypochlorous acid (HOCl) suitable for killing biofilm communities without substantially damaging host tissue. Production of HOCl near the e-scaffold surface was verified by measuring its concentration using needle-type microelectrodes. E-scaffolds producing 17, 10 and 7 mM HOCl completely eradicated S. aureus, A. baumannii, and P. aeruginosa biofilms after 3 hours, 2 hours, and 1 hour, respectively. Cytotoxicity and histopathological assessment showed no discernible harm to host tissues when e-scaffolds were applied to explant biofilms. The described strategy may provide a novel antibiotic-free strategy for treating persistent biofilm-associated infections, such as wound infections.","pmid":"30804362","doi":"10.1038/s41598-019-38968-y","url":"https://pubmed.ncbi.nlm.nih.gov/30804362/"},{"id":1257,"title":"Disinfection by-Products and Ecotoxic Risk Associated with Hypochlorite Treatment of Tramadol.","authors":"Romanucci, Valeria; Siciliano, Antonietta; Galdiero, Emilia; Guida, Marco; Luongo, Giovanni; Liguori, Renato; Di Fabio, Giovanni; Previtera, Lucio; Zarrelli, Armando","year":2019,"date":"2019 Feb 15","journal":"Molecules (Basel, Switzerland)","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"In recent years, many studies have highlighted the consistent finding of tramadol (TRA) in the effluents from wastewater treatment plants (WTPs) and also in some rivers and lakes in both Europe and North America, suggesting that TRA is removed by no more than 36% by specific disinfection treatments. The extensive use of this drug has led to environmental pollution of both water and soil, up to its detection in growing plants. In order to expand the knowledge about TRA toxicity as well as the nature of its disinfection by-products (DBPs), a simulation of the waste treatment chlorination step has been reported herein. In particular, we found seven new by-products, that together with TRA, have been assayed on different living organisms (Aliivibrio fischeri, Raphidocelis subcapitata and Daphnia magna), to test their acute and chronic toxicity. The results reported that TRA may be classified as a harmful compound to some aquatic organisms whereas its chlorinated product mixture showed no effects on any of the organisms tested. All data suggest however that TRA chlorination treatment produces a variety of DBPs which can be more harmful than TRA and a risk for the aquatic environment and human health.","pmid":"30769936","doi":"10.3390/molecules24040693","url":"https://pubmed.ncbi.nlm.nih.gov/30769936/"},{"id":1262,"title":"The apoA-I mimetic peptide 4F protects apolipoprotein A-I from oxidative damage.","authors":"White, C Roger; Datta, Geeta; Wilson, Landon; Palgunachari, Mayakonda N; Anantharamaiah, G M","year":2019,"date":"2019 Mar","journal":"Chemistry and physics of lipids","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"High density lipoprotein (HDL) is prone to modification by the oxidizing and chlorinating agent hypochlorite anion (OCl(-)). Oxidation of apolipoprotein (apo) A-I, the major protein in HDL, reduces ABCA-1 mediated cholesterol efflux and other protective responses to HDL. The apoA-I mimetic peptide 4F has been shown to undergo oxidation; however, the ability of the peptide to mediate cholesterol efflux remains intact. Here, we show that 4F protects apoA-I from hypochlorite-mediated oxidation. Mass spectral analysis of apoA-I shows that tyrosine residues that are prone to hypochlorite-mediated chlorination are protected in the presence of 4F. Furthermore, 4F enhances the cholesterol efflux ability of apoA-I to a greater extent than either 4F or apoA-I alone, even after hypochlorite oxidation. These observations suggest that apoA-I in lipid complexes may be protected by the presence of 4F, resulting in the preservation of its anti-inflammatory and anti-atherogenic properties. These studies also form the basis for the future studies of nanoparticles possessing both apoA-I and 4F.","pmid":"30707910","doi":"10.1016/j.chemphyslip.2019.01.009","url":"https://pubmed.ncbi.nlm.nih.gov/30707910/"},{"id":1274,"title":"Fluorescence Quenching-Based Mechanism for Determination of Hypochlorite by Coumarin-Derived Sensors.","authors":"Starzak, Karolina; Matwijczuk, Arkadiusz; Creaven, Bernadette; Matwijczuk, Alicja; Wybraniec, Sławomir; Karcz, Dariusz","year":2019,"date":"2019 Jan 11","journal":"International journal of molecular sciences","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"A fluorescence quenching-based mechanism for the determination of hypochlorite was proposed based on spectroscopic and chromatographic studies on the hypochlorite-sensing potency of three structurally similar and highly fluorescent coumarins. The mode of action was found to rely upon a chlorination of the coumarin-based probes resulting from their reaction with sodium hypochlorite. Importantly, the formation of chlorinated derivatives was accompanied by a linear decrease in the fluorescence intensities of the probes tested. The results obtained suggest the applicability of a coumarin-dependent hypochlorite recognition mechanism for the detection of, as well as for quantitative determination of, hypochlorite species in vitro.","pmid":"30642004","doi":"10.3390/ijms20020281","url":"https://pubmed.ncbi.nlm.nih.gov/30642004/"},{"id":1277,"title":"The Utility of Hypochlorous Acid Wound Therapy in Wound Bed Preparation and Skin Graft Salvage.","authors":"Odom, Elizabeth B; Mundschenk, Minh-Bao; Hard, Kathryn; Buck, Donald W 2nd","year":2019,"date":"2019 Mar","journal":"Plastic and reconstructive surgery","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"","pmid":"30601316","doi":"10.1097/PRS.0000000000005359","url":"https://pubmed.ncbi.nlm.nih.gov/30601316/"},{"id":1288,"title":"Chlorination and oxidation of the extracellular matrix protein laminin and basement membrane extracts by hypochlorous acid and myeloperoxidase.","authors":"Nybo, Tina; Dieterich, Simon; Gamon, Luke F; Chuang, Christine Y; Hammer, Astrid; Hoefler, Gerald; Malle, Ernst; Rogowska-Wrzesinska, Adelina; Davies, Michael J","year":2019,"date":"2019 Jan","journal":"Redox biology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Basement membranes are specialized extracellular matrices that underlie arterial wall endothelial cells, with laminin being a key structural and biologically-active component. Hypochlorous acid (HOCl), a potent oxidizing and chlorinating agent, is formed in vivo at sites of inflammation via the enzymatic action of myeloperoxidase (MPO), released by activated leukocytes. Considerable data supports a role for MPO-derived oxidants in cardiovascular disease and particularly atherosclerosis. These effects may be mediated via extracellular matrix damage to which MPO binds. Herein we detect and quantify sites of oxidation and chlorination on isolated laminin-111, and laminin in basement membrane extracts (BME), by use of mass spectrometry. Increased modification was detected with increasing oxidant exposure. Mass mapping indicated selectivity in the sites and extent of damage; Met residues were most heavily modified. Fewer modifications were detected with BME, possibly due to the shielding effects. HOCl oxidised 30 (of 56 total) Met and 7 (of 24) Trp residues, and chlorinated 33 (of 99) Tyr residues; 3 Tyr were dichlorinated. An additional 8 Met and 10 Trp oxidations, 14 chlorinations, and 18 dichlorinations were detected with the MPO/H(2)O(2)/Cl(-) system when compared to reagent HOCl. Interestingly, chlorination was detected at Tyr(2415) in the integrin-binding region; this may decrease cellular adhesion. Co-localization of MPO-damaged epitopes and laminin was detected in human atherosclerotic lesions. These data indicate that laminin is extensively modified by MPO-derived oxidants, with structural and functional changes. These modifications, and compromised cell-matrix interactions, may promote endothelial cell dysfunction, weaken the structure of atherosclerotic lesions, and enhance lesion rupture.","pmid":"30476874","doi":"10.1016/j.redox.2018.10.022","url":"https://pubmed.ncbi.nlm.nih.gov/30476874/"},{"id":1292,"title":"Safety and efficacy profiles of different commercial sodium hypochlorite/hypochlorous acid solutions (NaClO/HClO): antimicrobial efficacy, cytotoxic impact and physicochemical parameters in vitro.","authors":"Severing, Anna-Lena; Rembe, Julian-Dario; Koester, Verena; Stuermer, Ewa K","year":2019,"date":"2019 Feb 1","journal":"The Journal of antimicrobial chemotherapy","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"BACKGROUND: Sodium hypochlorite (NaClO, SHC)/hypochlorous acid (HClO, HCA) wound irrigation solutions have experienced a renaissance in the prevention and treatment of low-level wound infections. They are attributed with lower cytotoxicity and have therefore gained increasing attention in daily clinical practice. OBJECTIVES: To determine the cytotoxicity and antimicrobial efficacy of six NaClO/HClO wound irrigation solutions. METHODS: For cytotoxicity evaluation (based on DIN EN 10993-5), human keratinocytes (HaCaT) and human skin fibroblasts (BJ) were used. Staphylococcus aureus and Pseudomonas aeruginosa were used for antimicrobial efficacy evaluation (based on DIN EN 13727). Solutions were evaluated after 1, 5 and 15 min of exposure. Additionally, physicochemical properties (pH and oxidation-reduction potential values) were investigated. RESULTS: Efficacy and cytotoxicity varied significantly between solutions. Generally, increasing antimicrobial activity was associated with decreasing cell viability. Furthermore, a concentration- and time-dependent impact on pathogens and cells was observed: cytotoxic and antimicrobial activity increased with rising NaClO/HClO solution concentrations and extended exposure times. Based on these in vitro evaluations, the following ranking (lowest to highest microbicidal effect and cytotoxic impact) was found: Microdacyn60® (SHC/HCA-M) < Granudacyn® (SHC/HCA-G) < Veriforte™ (SHC/HCA-V) < KerraSol™ (SHC-K) < Lavanox® (SHC-L) ≪ ActiMaris®forte (SHC/SM-A). CONCLUSIONS: The presented results indicate that microbicidal effects are almost always associated with certain negative side effects on cell proliferation. Efficacy and biocompatibility of NaClO/HClO solutions depend on their specific formulation and physicochemical properties. The investigations also underline the necessity for exact product- and application-specific efficacy profiles.","pmid":"30388236","doi":"10.1093/jac/dky432","url":"https://pubmed.ncbi.nlm.nih.gov/30388236/"},{"id":1293,"title":"Heterogeneous Chlorination of Squalene and Oleic Acid.","authors":"Schwartz-Narbonne, Heather; Wang, Chen; Zhou, Shouming; Abbatt, Jonathan P D; Faust, Jennifer","year":2019,"date":"2019 Feb 5","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Washing with chlorine bleach leads to high mixing ratios of gas-phase HOCl. Using two methods that are sensitive to surface film composition-attenuated total reflection fourier transform infrared (ATR-FTIR) spectroscopy and direct analysis in real time mass spectrometry (DART-MS)-we present the first study of the chlorination chemistry that occurs when gaseous HOCl reacts with thin films of squalene and oleic acid. At mixing ratios of 600 ppbv, HOCl forms chlorohydrins by adding across carbon-carbon double bonds without breaking the carbon backbone. The initial uptake of one HOCl molecule occurs on the time scale of a few minutes at these mixing ratios. For oleic acid, ester formation proceeds immediately thereafter, leading to dimeric and trimeric chlorinated products. For squalene, subsequent HOCl uptake occurs until all six of its carbon-carbon double bonds become chlorinated within 1-2 h. These results indicate that chlorination of skin oil, which contains substantial carbon unsaturation, is likely to occur rapidly under common cleaning conditions, potentially leading to the irritation associated with chlorinated bleach. This chemistry will likely also proceed with cooking oils, in the human respiratory system which has unsaturated surfactants as important components of lung fluid, and with organic components of the sea surface microlayer.","pmid":"30387352","doi":"10.1021/acs.est.8b04248","url":"https://pubmed.ncbi.nlm.nih.gov/30387352/"},{"id":1299,"title":"Postoperative effects on lower third molars of using mouthwashes with super-oxidized solution versus 0.2% chlorhexidine gel: A randomized double-blind trial.","authors":"Coello-Gómez, A; Navarro-Suárez, S; Diosdado-Cano, J-M; Azcárate-Velazquez, F; Bargiela-Pérez, P; Serrera-Figallo, M-A; Torres-Lagares, D; Gutiérrez-Pérez, J-L","year":2018,"date":"2018 Nov 1","journal":"Medicina oral, patologia oral y cirugia bucal","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"BACKGROUND: The main objective of the present study is to evaluate the effects and possible benefits with regard to the postoperative period of lower third molar extractions, comparing the intraalveolar application of a bioadhesive gel of 0.2% chlorhexidine (CHX) to the use of a mouthwash with a super-oxidized solution, (SOS) Dermacyn® Wound Care (Oculus Innovative Sciences lnc., California, USA). MATERIAL AND METHODS: A randomized double-blind study was carried out in 20 patients with a split-mouth design, with a total of 40 extractions of symmetrically impacted bilateral lower third molars. Patients were divided into two groups, a control group (C = 20) and an experimental group (D = 20). Any infectious complications, wound healing, plaque accumulation in the stitches, and presence of trismus and inflammation were evaluated using the distance between different facial points, at three, eight, and fifteen days after extraction. Pain, swelling, and amount of analgesics taken were evaluated using the VAS scale throughout the 15 days following extraction. Tolerance to treatment was evaluated using a verbal scale. Results were statistically compared using the Student's t- and chi-squared tests. RESULTS: No statistically significant differences were found between the two groups with regard to infectious complications, swelling, or wound healing. Use of analgesics and self-reported pain levels were slightly lower in the experimental group than in the control group during days 6 and 7 of the study (p < 0.05). The global treatment tolerance was satisfactory and similar in both groups. CONCLUSIONS: Both CHX and SOS are effective at improving the postoperative period after extraction of lower third molars.","pmid":"30341268","doi":"10.4317/medoral.22622","url":"https://pubmed.ncbi.nlm.nih.gov/30341268/"},{"id":1302,"title":"Evaluation of residual toxicity of hypochlorite-treated water using bioluminescent microbes and microalgae: Implications for ballast water management.","authors":"Lee, Jung-Suk; Hong, Seongjin; Lee, Junghyun; Choi, Tae Seob; Rhie, Kitae; Khim, Jong Seong","year":2019,"date":"2019 Jan 15","journal":"Ecotoxicology and environmental safety","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Total residual oxidants (TRO) in treated ballast water can produce various disinfection by-products (DBPs) depending on local conditions, such as salinity and organic matter content in water. Because TRO and DBPs are known to be harmful to aquatic organisms and humans, ecotoxicity tests have been proposed for screening the residual toxicity before discharging treated ballast water. In the present study, we aimed to address the decay rates and toxicity changes of TRO under various conditions in salinity, initial TRO concentrations, and residence time of TRO. In addition, the toxicological sensitivities of bioluminescent bacteria Vibrio fischeri and a commonly-used microalgae Skeletonema costatum relative to the residual toxicity of TRO and six selected DBPs were determined. Decay rate of TRO concentration increased as a function of salinity and was affected by the initial concentrations of TRO. Unexpectedly, significant bioluminescence inhibition was observed for hypochlorite-treated water at < 0.1 mg L(-1) TRO (expressed as Cl(2)), which is a lower concentration than the maximum allowable discharge concentration (MADC) to marine waters established by the International Maritime Organization (IMO). The ecotoxicological thresholds of no observed effective concentration and median effect concentration for all tested DBPs were about 3-10 times lower for V. fischeri than for S. costatum. The results indicate that bioluminescent microbes possess an ecologically-relevant sensitivity to both TRO and DBPs in ballast water. In general, bioassay using V. fischeri was potentially more effective than microalgae for screening the total toxicity of TRO and DBPs in treated ballast water, especially given that ballast water usually contains a highly variable and complex mixture of toxicants.","pmid":"30317117","doi":"10.1016/j.ecoenv.2018.10.002","url":"https://pubmed.ncbi.nlm.nih.gov/30317117/"},{"id":1307,"title":"pH controlled byproduct formation in aqueous decomposition of N-chloro-α-alanine.","authors":"Simon, Fruzsina; Szabó, Mária; Fábián, István","year":2019,"date":"2019 Jan 15","journal":"Journal of hazardous materials","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"N-chloro-amino acids are readily formed in chlorination water treatment technologies. These reactions are also important in biological systems where HOCl plays an important role in the defense mechanism against invading pathogens. The intermediates and the products formed are of primary concern because they may have significant biological activities. In order to clarify intimate details and resolve discrepancies in the literature, the decomposition kinetics of N-chloro-α-alanine (MCA) was studied in the neutral - alkaline pH range by UV-vis spectrophotometry and (1)H-NMR method. In contrast to earlier reports, the decomposition reaction proceeds via two distinct reaction paths: k(obs1) = k(OH)[OH(-)] + k, where k(OH) = (1.38 ± 0.02) × 10(-2) M(-1)s(-1) and k = (2.95 ± 0.09) × 10(-4) s(-1). In slightly alkaline solution, the sole product is acetaldehyde. Under alkaline conditions, the main product is pyruvate ion, however, N-acetyl-α-alanine is also formed in a subsequent reaction sequence. A detailed kinetic model is postulated which involves the rate determining dissociation of MCA into Cl(-) and ethanimine which produces acetaldehyde in further reaction steps. Via the OH(-) assisted path, first a carbanion is formed which undergoes dechlorination and produces iminopropionate ion. This species is transformed into pyruvate ion through hydration and deamination steps.","pmid":"30243251","doi":"10.1016/j.jhazmat.2018.09.004","url":"https://pubmed.ncbi.nlm.nih.gov/30243251/"},{"id":1308,"title":"Chlorination and oxidation of human plasma fibronectin by myeloperoxidase-derived oxidants, and its consequences for smooth muscle cell function.","authors":"Nybo, Tina; Cai, Huan; Chuang, Christine Y; Gamon, Luke F; Rogowska-Wrzesinska, Adelina; Davies, Michael J","year":2018,"date":"2018 Oct","journal":"Redox biology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Fibronectin (FN) occurs as both a soluble form, in plasma and at sites of tissue injury, and a cellular form in tissue extracellular matrices (ECM). FN is critical to wound repair, ECM structure and assembly, cell adhesion and proliferation. FN is reported to play a critical role in the development, progression and stability of cardiovascular atherosclerotic lesions, with high FN levels associated with a thick fibrotic cap, stable disease and a low risk of rupture. Evidence has been presented for FN modification by inflammatory oxidants, and particularly myeloperoxidase (MPO)-derived species including hypochlorous acid (HOCl). The targets and consequences of FN modification are poorly understood. Here we show, using a newly-developed MS protocol, that HOCl and an enzymatic MPO system, generate site-specific dose-dependent Tyr chlorination and dichlorination (up to 16 of 100 residues modified), and oxidation of Trp (7 of 39 residues), Met (3 of 26) and His (1 of 55) within selected FN domains, and particularly the heparin- and cell-binding regions. These alterations increase FN binding to heparin-containing columns. Studies using primary human coronary artery smooth muscle cells (HCASMC) show that exposure to HOCl-modified FN, results in decreased adherence, increased proliferation and altered expression of genes involved in ECM synthesis and remodelling. These findings indicate that the presence of modified fibronectin may play a major role in the formation, development and stabilisation of fibrous caps in atherosclerotic lesions and may play a key role in the switching of quiescent contractile smooth muscle cells to a migratory, synthetic and proliferative phenotype.","pmid":"30237127","doi":"10.1016/j.redox.2018.09.005","url":"https://pubmed.ncbi.nlm.nih.gov/30237127/"},{"id":1310,"title":"Quantitative assessment of cyanide in cystic fibrosis sputum and its oxidative catabolism by hypochlorous acid.","authors":"Eiserich, Jason P; Ott, Sean P; Kadir, Tamara; Morrissey, Brian M; Hayakawa, Keri A; La Merrill, Michele A; Cross, Carroll E","year":2018,"date":"2018 Dec","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"RATIONALE: Cystic fibrosis (CF) patients are known to produce cyanide (CN(-)) although challenges exist in determinations of total levels, the precise bioactive levels, and specificity of its production by CF microflora, especially P. aeruginosa. Our objective was to measure total CN(-) levels in CF sputa by a simple and novel technique in P. aeruginosa positive and negative adult patients, to review respiratory tract (RT) mechanisms for the production and degradation of CN(-), and to interrogate sputa for post-translational protein modification by CN(-) metabolites. METHODS: Sputa CN(-) concentrations were determined by using a commercially available CN(-) electrode, measuring levels before and after addition of cobinamide, a compound with extremely high affinity for CN(-). Detection of protein carbamoylation was measured by Western blot. MEASUREMENTS AND MAIN RESULTS: The commercial CN(-) electrode was found to overestimate CN(-) levels in CF sputum in a highly variable manner; cobinamide addition rectified this analytical issue. Although P. aeruginosa positive patients tended to have higher total CN(-) values, no significant differences in CN(-) levels were found between positive and negative sputa. The inflammatory oxidant hypochlorous acid (HOCl) was shown to rapidly decompose CN(-), forming cyanogen chloride (CNCl) and the carbamoylating species cyanate (NCO(-)). Carbamoylated proteins were found in CF sputa, analogous to reported findings in asthma. CONCLUSIONS: Our studies indicate that CN(-) is a transient species in the inflamed CF airway due to multiple biosynthetic and metabolic processes. Stable metabolites of CN(-), such as cyanate, or carbamoylated proteins, may be suitable biomarkers of overall CN(-) production in CF airways.","pmid":"30213640","doi":"10.1016/j.freeradbiomed.2018.09.007","url":"https://pubmed.ncbi.nlm.nih.gov/30213640/"},{"id":1312,"title":"Antiviral innate immune response in non-myeloid cells is augmented by chloride ions via an increase in intracellular hypochlorous acid levels.","authors":"Ramalingam, Sandeep; Cai, Baiyi; Wong, Junsheng; Twomey, Matthew; Chen, Rui; Fu, Rebecca M; Boote, Toby; McCaughan, Hugh; Griffiths, Samantha J; Haas, Jürgen G","year":2018,"date":"2018 Sep 11","journal":"Scientific reports","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Phagocytes destroy ingested microbes by producing hypochlorous acid (HOCl) from chloride ions (Cl(-)) and hydrogen peroxide within phagolysosomes, using the enzyme myeloperoxidase. HOCl, the active ingredient in bleach, has antibacterial/antiviral properties. As myeloperoxidase is needed for HOCl production, non-myeloid cells are considered incapable of producing HOCl. Here, we show that epithelial, fibroblast and hepatic cells have enhanced antiviral activity in the presence of increasing concentrations of sodium chloride (NaCl). Replication of enveloped/non-enveloped, DNA (herpes simplex virus-1, murine gammaherpesvirus 68) and RNA (respiratory syncytial virus, influenza A virus, human coronavirus 229E, coxsackievirus B3) viruses are inhibited in a dose-dependent manner. Whilst treatment with sodium channel inhibitors did not prevent NaCl-mediated virus inhibition, a chloride channel inhibitor reversed inhibition by NaCl, suggesting intracellular chloride is required for antiviral activity. Inhibition is also reversed in the presence of 4-aminobenzoic hydrazide, a myeloperoxidase inhibitor, suggesting epithelial cells have a peroxidase to convert Cl(-) to HOCl. A significant increase in intracellular HOCl production is seen early in infection. These data suggest that non-myeloid cells possess an innate antiviral mechanism dependent on the availability of Cl(-) to produce HOCl. Antiviral activity against a broad range of viral infections can be augmented by increasing availability of NaCl.","pmid":"30206371","doi":"10.1038/s41598-018-31936-y","url":"https://pubmed.ncbi.nlm.nih.gov/30206371/"},{"id":1314,"title":"Role of hypochlorous acid (HOCl) and other inflammatory mediators in the induction of macrophage extracellular trap formation.","authors":"Rayner, Benjamin S; Zhang, Yunjia; Brown, Bronwyn E; Reyes, Leila; Cogger, Victoria C; Hawkins, Clare L","year":2018,"date":"2018 Dec","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The infiltration of activated leukocytes, including macrophages, at sites of inflammation and the formation and presence of hypochlorous acid (HOCl) are interlinked hallmarks of many debilitating disease processes, including atherosclerosis, arthritis, neurological and renal disease, diabetes and obesity. The production of extracellular traps by activated leukocytes in response to a range of inflammatory stimuli is increasingly recognised as an important process within a range of disease settings. We show that exposure of human monocyte-derived macrophages to pathophysiological levels of HOCl results in the dose-dependent extrusion of DNA and histones into the cellular supernatant, consistent with extracellular trap formation. Concurrent with, but independent of these findings, macrophage exposure to HOCl also resulted in an immediate and sustained cytosolic accumulation of Ca(2+), culminating in the increased production of cytokines and chemokines. Polarisation of the macrophages prior to HOCl exposure revealed a greater propensity for inflammatory M1 macrophages to produce extracellular traps, whereas alternatively-activated M2 macrophages were less susceptible to HOCl insult. M1 macrophages also produced extracellular traps on exposure to phorbol myristate acetate (PMA), interleukin-8 (IL-8) and tumour necrosis factor α (TNFα). Taken together, these data indicate a potential role for macrophages in mediating extracellular trap formation, which may be relevant in pathological conditions characterised by chronic inflammation or excessive HOCl formation.","pmid":"30189264","doi":"10.1016/j.freeradbiomed.2018.09.001","url":"https://pubmed.ncbi.nlm.nih.gov/30189264/"},{"id":1315,"title":"Antioxidant Activity of Hydrogen Nanobubbles in Water with Different Reactive Oxygen Species both in Vivo and in Vitro.","authors":"Liu, Shu; Oshita, Seiichi; Thuyet, Dang Quoc; Saito, Masanao; Yoshimoto, Takahiko","year":2018,"date":"2018 Oct 2","journal":"Langmuir : the ACS journal of surfaces and colloids","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hydrogen water as a new therapeutic antioxidant has been widely used in living organisms under stress. In this study, we applied nanobubble (NB) technology to hydrogen water. The antioxidant capacity of hydrogen NB water was studied with respect to different reactive oxygen species (ROS) both in vitro and in vivo. Using a relatively weak reduced dye, APF, we showed that hydrogen NB water can effectively remove three cytotoxic ROS, (•)OH, ClO(-), and ONOO(-), from water. Hydrogen NB water could also remove O(2)(•-), which is a physiologically important ROS, from water. However, hydrogen water could not reduce other physiologically important ROS such as H(2)O(2) and NO. At similar dissolved hydrogen concentrations, hydrogen NB water displayed higher antioxidant activity than hydrogen water without NB. Barley seed germination tests were used to study the antioxidant effect of hydrogen NB water on ROS generation in vivo. Our results showed that this decreased the physiological activity of barley seeds in their normal homeostatic state. Hydrogen NB water eliminated endogenous O(2)(•-) in seeds and inhibited germination. The usage of hydrogen NB water should be individually considered according to the types of cells involved. Our results offer basic data concerning the application of hydrogen NB water in different fields.","pmid":"30189133","doi":"10.1021/acs.langmuir.8b02440","url":"https://pubmed.ncbi.nlm.nih.gov/30189133/"},{"id":1318,"title":"Heterogeneity of hypochlorous acid production in individual neutrophil phagosomes revealed by a rhodamine-based probe.","authors":"Albrett, Amelia M; Ashby, Louisa V; Dickerhof, Nina; Kettle, Anthony J; Winterbourn, Christine C","year":2018,"date":"2018 Oct 5","journal":"The Journal of biological chemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The rhodamine-based probe R19-S has been shown to react with hypochlorous acid (HOCl) to yield fluorescent R19, but not with some other oxidants including hydrogen peroxide. Here, we further examined the specificity of R19-S and used it for real-time monitoring of HOCl production in neutrophil phagosomes. We show that it also reacts rapidly with hypobromous acid, bromamines, and hypoiodous acid, indicating that R19-S responds to these reactive halogen species as well as HOCl. Hypothiocyanous acid and taurine chloramine were unreactive, however, and ammonia chloramine and dichloramine reacted only very slowly. MS analyses revealed additional products from the reaction of HOCl with R19-S, including a chlorinated species as a minor product. Of note, phagocytosis of opsonized zymosan or Staphylococcus aureus by neutrophils was accompanied by an increase in R19 fluorescence. This increase depended on NADPH oxidase and myeloperoxidase activities, and detection of chlorinated R19-S confirmed its specificity for HOCl. Using live-cell imaging to track individual phagosomes in single neutrophils, we observed considerable heterogeneity among the phagosomes in the time from ingestion of a zymosan particle to when fluorescence was first detected, ranging from 1 to >30 min. However, once initiated, the subsequent fluorescence increase was uniform, reaching a similar maximum in ∼10 min. Our results confirm the utility of R19-S for detecting HOCl in real-time and provide definitive evidence that isolated neutrophils produce HOCl in phagosomes. The intriguing variability in the onset of HOCl production among phagosomes identified here could influence the way they kill ingested bacteria.","pmid":"30135208","doi":"10.1074/jbc.RA118.004789","url":"https://pubmed.ncbi.nlm.nih.gov/30135208/"},{"id":1321,"title":"Commentary on: Surgical Breast Pocket Irrigation With Hypochlorous Acid (HOCl): An In Vivo Evaluation of Pocket Protein Content and Potential HOCl Antimicrobial Capacity.","authors":"Van Natta, Bruce W","year":2018,"date":"2018 Oct 15","journal":"Aesthetic surgery journal","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"","pmid":"30084921","doi":"10.1093/asj/sjy148","url":"https://pubmed.ncbi.nlm.nih.gov/30084921/"},{"id":1322,"title":"Surgical Breast Pocket Irrigation With Hypochlorous Acid (HOCl): An In Vivo Evaluation of Pocket Protein Content and Potential HOCl Antimicrobial Capacity.","authors":"Haws, Melinda J; Gingrass, Mary K; Porter, R Stephen; Brindle, C Tod","year":2018,"date":"2018 Oct 15","journal":"Aesthetic surgery journal","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"BACKGROUND: Hypochlorous acid (HOCl) demonstrates rapid and broad antimicrobial activity against planktonic and biofilm phenotype bacteria in vitro. OBJECTIVES: To identify the protein content present in breast pockets in vivo and calculate the estimated active concentration of HOCl, (PhaseOne, Integrated Healing Technologies, Franklin, TN) following HOCl-protein interactions. METHODS: Fluid samples were collected prior to implant insertion in 18 consecutive patients, representing 36 pocket samples, with all cases being bilateral primary breast augmentations. Samples were evaluated by an independent CLIA approved laboratory for albumin and total protein concentration in g/dL. Results were compared to HOCl solution concentration and protein binding potential to determine availability of free HOCl. RESULTS: The mean tissue sample concentration (right and left breast) was 31.6 mg/dL which translates to 0.0001 mmol per 20 cc of interstitial fluid. Mean total protein levels (right and left breast) were 62.3 mg/dL or 0.000187 mmol per 20 cc interstitial fluid. Based upon potential stoichiometric neutralization of HOCl by proteins in either a 1:1 or 3:1 ratio, using 115 cc of HOCl solution (per breast) at a concentration of 250 ppm/mL or 0.025% HOCl or = 0.48 mmol HOCl/dL, there would be 2950 times the amount of active HOCl at a 1:1 reaction ratio, or 983 times more HOCl assuming a 3:1 reaction ratio. Based on the range of identified levels of protein in individual surgical pockets in the study, there is an estimated 242 to 12,500 times more HOCl molecules than protein at a 3:1 molar ratio of binding or reactive protein. CONCLUSIONS: n estimated range of 983-2950 times more HOCl molecules are present during irrigation with 230 cc of PhaseOne® (115 cc for each breast) than available protein. This supports the antimicrobial and anti-biofilm activity as described in previous in vitro studies when using PhaseOne® as part of pocket irrigation.","pmid":"30084898","doi":"10.1093/asj/sjy031","url":"https://pubmed.ncbi.nlm.nih.gov/30084898/"},{"id":1327,"title":"Antimicrobial activity of hypochlorite solutions and reciprocating instrumentation associated with photodynamic therapy on root canals infected with Enterococcus faecalis - An in vitro study.","authors":"Souza, Matheus Albino; Tumelero Dias, Caroline; Zandoná, Julia; Paim Hoffmann, Igor; Sanches Menchik, Vitor Hugo; Palhano, Huriel Scartazzini; Bertol, Charise Dallazem; Rossato-Grando, Luciana Grazziotin; Cecchin, Doglas; de Figueiredo, José Antônio Poli","year":2018,"date":"2018 Sep","journal":"Photodiagnosis and photodynamic therapy","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"INTRODUCTION: The aim of this study is to evaluate the antimicrobial activity of hypochlorite solutions and reciprocating instrumentation associated with photodynamic therapy (PDT). METHODS: One hundred and thirty two root canals were enlarged up to #35 K-file and inoculated with E.faecalis for 14 days. The 132 samples were randomly divided into eleven groups (n = 12) and subjected to the following protocols: G1-distilled water + Reciproc R40 (control), G2-1% sodium hypochlorite (NaOCl) + Reciproc R40, G3-2.5% NaOCl + Reciproc R40; G4-1% calcium hypochlorite (Ca[OCl](2)) + Reciproc R40, G5-2.5% Ca(OCl)(2) + Reciproc R40; G6-PDT; G7-distilled water + Reciproc R40 + PDT, G8-1% NaOCl + Reciproc R40 + PDT, G9-2.5% NaOCl + Reciproc R40 + PDT; G10-1% Ca(OCl)(2) + Reciproc R40 + PDT, G11-2.5% Ca(OCl)(2) + Reciproc R40 + PDT. The percentage bacterial reduction was checked by counting the colony-forming units (CFUs) in 10 samples of each group. The remaining 2 samples of each group were submitted to scanning electronic microscopy (SEM) to illustrate the effectiveness of the proposed treatments. Data were subjected to one-way ANOVA followed by Tukey's post hoc test (α = 0.05). RESULTS: The greatest ability to promote bacterial reduction was observed in groups 8 (1% NaOCl + R40 + PDT), 9 (2.5% NaOCl + R40 + PDT), 10 (1% Ca[OCl](2) + R40 + PDT), and 11 (2.5% Ca[OCl](2) + R40 + PDT), with no significant difference between them (p < 0.05). CONCLUSIONS: The association of PDT with hypochlorite solutions and reciprocating instrumentation provides effective elimination of E.faecalis.","pmid":"30053480","doi":"10.1016/j.pdpdt.2018.07.015","url":"https://pubmed.ncbi.nlm.nih.gov/30053480/"},{"id":1331,"title":"0.01% Hypochlorous Acid as an Alternative Skin Antiseptic: An In Vitro Comparison.","authors":"Anagnostopoulos, Apostolos G; Rong, Andrew; Miller, Darlene; Tran, Ann Q; Head, Trajen; Lee, Michael C; Lee, Wendy W","year":2018,"date":"2018 Dec","journal":"Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVE: Compare the in vitro efficacy of hypochlorous acid 0.01% (HA), povidone iodine 5% (PI), chlorhexidine gluconate 4% (CHG), and isopropyl alcohol 70% (IPA) against common skin microorganisms. MATERIALS AND METHODS: Time-kill studies were conducted against methicillin-susceptible Staphylococcus aureus (MSSA) and Staphylococcus epidermidis (MSSE), methicillin-resistant S. aureus (MRSA) and S. epidermidis (MRSE), Candida albicans, Corynebacterium species (striatum and amycolatum), Propionibacterium acnes, Pseudomonas aeruginosa, Streptococcus pyogenes, Staphylococcus capitis, and Staphylococcus xylosus. RESULTS: Methicillin-resistant S. aureus: Bactericidal effect was immediate for HA and IPA. For PI and CHG, the effect occurred at 1 and 10 minutes, respectively. Methicillin-resistant S. epidermidis: Hypochlorous acid, IPA, and PI had immediate bactericidal effects, whereas CHG required 1 minute. Methicillin-susceptible Staphylococcus aureus: All agents had bactericidal effects at 1 minute. C. species, S. pyogenes, P. aeruginosa, and P. acnes: All antiseptics demonstrated immediate bactericidal effects. Methicillin-susceptible Staphylococcus epidermidis and S. capitis: Hypochlorous acid and IPA had immediate effect, whereas PI and CHG required 1 minute. C. albicans: Hypochlorous acid, IPA, and PI were immediately bactericidal, whereas CHG required 1 minute. S. xylosus: Hypochlorous acid and CHG were immediately bactericidal, whereas IPA and PI required 1 and 2 minutes, respectively. CONCLUSION: In vitro studies of HA 0.01% were observed to have equal or more efficacious antiseptic properties compared with IPA, CHG, and PI. Future studies will be needed to investigate its role in periocular use.","pmid":"29985866","doi":"10.1097/DSS.0000000000001594","url":"https://pubmed.ncbi.nlm.nih.gov/29985866/"},{"id":1334,"title":"Chlorine Dioxide-Pollutant Transformation and Formation of Hypochlorous Acid as a Secondary Oxidant.","authors":"Terhalle, Jens; Kaiser, Pascal; Jütte, Mischa; Buss, Johanna; Yasar, Sermin; Marks, Robert; Uhlmann, Helmut; Schmidt, Torsten C; Lutze, Holger V","year":2018,"date":"2018 Sep 4","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Chlorine dioxide (ClO(2)) has been used as a disinfectant in water treatment for a long time, and its use for micropollutant abatement in wastewater has recently been suggested. Surprisingly, a mechanistic understanding of ClO(2) reactions in (waste)water matrices is largely lacking. The present study contributes to this mechanistic understanding by performing a detailed investigation of ClO(2) reactions with organic matter using phenol as a surrogate for reactive phenolic moieties. A concept for indirectly determining HOCl using 2- and 4-bromophenol was developed. The reaction of phenol with ClO(2) formed chlorite (62 ± 4% per ClO(2) consumed) and hypochlorous acid (HOCl) (42 ± 3% per ClO(2) consumed). The addition of ClO(2) to wastewater (5 × 10(-5) M ClO(2)) resulted in 40% atenolol and 47% metoprolol transformation. The presence of the selective HOCl scavenger glycine largely diminished their transformation, indicating that atenolol and metoprolol were transformed by a fast reaction with HOCl (e.g., k (atenolol + HOCl) = 3.5 × 10(4) M(-1) s(-1)) that formed in ClO(2) reactions with the wastewater matrix. The formation of HOCl may thus increase the number of transformable micropollutants in ClO(2) applications. However, chlorine related byproducts may also be formed.","pmid":"29966411","doi":"10.1021/acs.est.8b01099","url":"https://pubmed.ncbi.nlm.nih.gov/29966411/"},{"id":1337,"title":"Achieving low concentrations of chromium in drinking water by nanofiltration: membrane performance and selection.","authors":"Giagnorio, Mattia; Ruffino, Barbara; Grinic, Daria; Steffenino, Sara; Meucci, Lorenza; Zanetti, Maria Chiara; Tiraferri, Alberto","year":2018,"date":"2018 Sep","journal":"Environmental science and pollution research international","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"This study evaluates nanofiltration as a feasible process to reach low concentrations of chromium in drinking water and provides means for the selection of the most suitable membrane based on the specific treatment needs. Chromium removal is concerning since new stringent limits (10 μg/L) for hexavalent Cr concentration in potable water were recently adopted in various countries. Three commercial nanofiltration membranes were tested against this threshold value: two membranes made of semi-aromatic polyamide and the third having a sulfonated polyethersulfone asymmetric film as the selective layer. The rejection observed as a function of chemical composition in the feed solution suggests that electrostatic effect is an important mechanism of chromium(VI) removal for the membranes with higher surface charge and lower film density. The performance of such membranes is strongly affected by the presence of salts, especially divalent cations, which reduce both Cr(VI) rejection and the permeate flux. The removal of Cr(VI) by denser membranes is dominated by solution-diffusion and is not influenced by feed ionic strength. The exposure of membranes to high chromium concentrations and to hypochlorite, typically employed as an oxidizing agent in water treatment plants, was also investigated. An analysis of the operational membrane life is thus discussed, based on the loss in performance due to active film degradation. All three membranes showed adequate rejection of chromium from tap and well water of diverse chemical composition, suggesting that nanofiltration is an effective process to remove chromium for the production of safe drinking water. However, membranes with different properties should be adopted depending on specific feed water composition and on the productivity required from the system. A final analysis is presented to help with the choice of the most suitable nanofiltration membrane based on initial and target Cr(VI) concentration in feed and product water, respectively.","pmid":"29946838","doi":"10.1007/s11356-018-2627-5","url":"https://pubmed.ncbi.nlm.nih.gov/29946838/"},{"id":1339,"title":"The stability of chlorinated, brominated, and iodinated haloacetamides in drinking water.","authors":"Ding, Shunke; Chu, Wenhai; Krasner, Stuart W; Yu, Yun; Fang, Chao; Xu, Bin; Gao, Naiyun","year":2018,"date":"2018 Oct 1","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Haloacetamides (HAMs), a group of nitrogenous disinfection byproducts (N-DBPs), can decompose to form corresponding intermediate products and other DBPs. The stability of ten different HAMs, including two chlorinated, five brominated, and three iodinated species was investigated with and without the presence of chlorine, chloramines, and reactive solutes such as quenching agents. The HAM basic hydrolysis and chlorination kinetics were well described by a second-order kinetics model, including first-order in HAM and hydroxide and first-order in HAM and hypochlorite, respectively, whereas the HAM neutral hydrolysis kinetic was first-order in HAM. Furthermore, HAMs decompose instantaneously when exposed to hypochlorite, which was almost two and nine orders of magnitude faster than HAM basic and neutral hydrolysis, respectively. In general, HAM hydrolysis and chlorination rates both increased with increasing pH and the number of halogens substituted on the methyl group. Moreover, chlorinated HAMs are more unstable than their brominated analogs, followed by the iodinated ones, due to the decrease in the electron-withdrawing inductive effect from chlorine to iodine atom. During hydrolysis, HAMs mainly directly decompose into the corresponding haloacetic acids (HAAs) via a nucleophilic reaction between the carbonyl carbon and hydroxide. For HAM chlorination reactions, hypochlorite reacts with HAMs to form the N-chloro-HAMs (N-Cl-HAMs) via Cl(+) transfer from chlorine to the amide nitrogen. N-Cl-HAMs can further degrade to form HAAs via hypochlorous acid addition. In contrast, the reactions between chloramines and HAMs were found to be insignificant. Additionally, four common quenching agents, including sodium sulfite, sodium thiosulfate, ascorbic acid, and ammonium chloride, were demonstrated to expedite HAM degradation, whereas ammonium chloride was the least influential among the four. Taft linear free energy relationships were established for both HAM hydrolysis and chlorination reactions, based on which the hydrolysis and chlorination rate constants for three monohaloacetamides were estimated. The hydrolysis and chlorination rates of 13 HAMs decreased in the following order: TCAM > BDCAM > DBCAM > TBAM > DCAM > BCAM > DBAM > CIAM > BIAM > DIAM > MCAM > MBAM > MIAM (where C = chloro, B = bromo, I = iodo, T = tri, D = di, M = mono). Lastly, using the HAM kinetic model established in this study, HAM half-lifes in drinking water distribution systems can be predicted on the basis of pH and residual chlorine concentration.","pmid":"29920459","doi":"10.1016/j.watres.2018.06.024","url":"https://pubmed.ncbi.nlm.nih.gov/29920459/"},{"id":1340,"title":"Wavelength-dependent chlorine photolysis and subsequent radical production using UV-LEDs as light sources.","authors":"Yin, Ran; Ling, Li; Shang, Chii","year":2018,"date":"2018 Oct 1","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"UV-LEDs are considered as the most promising UV light sources, because it has the potential to replace conventional UV lamps in some water treatment applications in the foreseeable future. In this study, UV-LEDs at four wavelengths in the UV-C or near UV-C range (i.e., 257.7, 268, 282.3, and 301.2 nm) were used to investigate the wavelength-dependency on chlorine photolysis and its subsequent radical formation. The fluence-based photodecay rates of hypochlorous acid (HOCl) and hypochlorite (OCl(-)) were monotonically correlated to their molar absorption coefficients and quantum yields, and the chlorine photodecay rates were much more significantly affected by molar absorption coefficients (β = 0.949) than quantum yields (β = 0.055). An empirical model that incorporated the chlorine photodecay rate constants, quantum yields, and molar absorption coefficients of HOCl and OCl(-) was established, validated and then used to predict the chlorine photodecay rate at any wavelength (257.7-301.2 nm) and pH (5-10). The modelling results suggested that the maximum fluence-based rate constant (1.46 × 10(-4) m(2) J(-1)) was obtained at 289.7 nm and pH 9.95. The wavelength dependency was larger at alkaline pH than at acidic pH, and the pH dependency was the largest at the longest wavelength. The formation of hydroxyl radicals (HO·) and reactive chlorine species (RCS) decreased with increasing wavelength at pH 6, and increased with increasing wavelength at pH 7. More HO· was formed at pH 6 than pH 7, but RCS showed the opposite pH-dependency. The findings in this study provide the fundamental information in selecting UV-LEDs with specific wavelength for enhancing/optimizing chlorine photodecay and/or its radical generation at different pHs in real-world applications.","pmid":"29913386","doi":"10.1016/j.watres.2018.06.018","url":"https://pubmed.ncbi.nlm.nih.gov/29913386/"},{"id":1346,"title":"Insight into the interactions of proteinase inhibitor- alpha-2-macroglobulin with hypochlorite.","authors":"Siddiqui, Tooba; Zia, Mohammad Khalid; Ali, Syed Saqib; Ahsan, Haseeb; Khan, Fahim Halim","year":2018,"date":"2018 Oct 1","journal":"International journal of biological macromolecules","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Hypochlorous acid (HOCl), an active bleaching agent is one of the major oxidant produced by neutrophils under physiological conditions. It is among one of the most potent reactive oxygen species (ROS) which causes oxidation of biomolecules. Treatment of proteins with hypochlorite results in direct oxidative damage to the protein. Alpha-2-macroglobulin (α(2)M) is a major proteinase inhibitor that can inhibit proteinase of any kind regardless of their specificity and catalytic mechanism. The proteinase-antiproteinase balance plays an important role in mediating inflammation associated tissue destruction. In this paper, we intend to study hypochlorite induced modifications in proteinase inhibitor- α(2)M via biophysical techniques such as absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD), fourier transform infrared spectrometry (FTIR) and isothermal titration calorimetry (ITC). It was found that hypochlorite decreases the anti-proteolytic potential and causes inactivation of sheep α(2)M. It also causes structural and functional change in sheep α(2)M as evident by UV-Visible absorption spectroscopy and fluorescence measurements. Change in secondary structure of α(2)M was confirmed by CD and FTIR. Thermodynamics parameters such as entropy change (ΔS), enthalpy change (ΔH), Gibbs free energy change (ΔG) and the number of binding sites (N) of α(2)M-HOCl binding in solutions were determined by ITC. Moreover, it was found that binding of HOCl with α(2)M was exothermic in nature.","pmid":"29778882","doi":"10.1016/j.ijbiomac.2018.05.112","url":"https://pubmed.ncbi.nlm.nih.gov/29778882/"},{"id":1347,"title":"Disinfection of transboundary animal disease viruses on surfaces used in pork packing plants.","authors":"Krug, Peter W; Davis, Talina; O'Brien, Catherine; LaRocco, Michael; Rodriguez, Luis L","year":2018,"date":"2018 Jun","journal":"Veterinary microbiology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"In the event of an intentional or accidental incursion of a transboundary animal disease (TAD) virus into the US, a major concern to the meat industry would be the potential contamination of packing plants by processing infected animals. TAD agents such as foot and mouth disease virus (FMDV), African swine fever virus (ASFV) and classical swine fever virus (CSFV) are found in swine products such as blood and feces and are present in the tissues of infected animals. To test the disinfection of TAD viruses in a pork-packing environment, a previously developed disinfection assay was used to test two biocides currently used by industry sanitarians, against TAD viruses dried on industry relevant surfaces in saline or swine products. With the exception of one virus, both commercial disinfectants tested were effective against the TAD viruses dried on steel, plastic, and sealed concrete surfaces in the absence of the swine products. Disinfectant activity was greatly inhibited in the presence of dried blood and meat juices. The acidic disinfectants were able to inactivate the viruses in swine feces whereas fecal material generally inhibited sodium hypochlorite-based disinfectants. These results highlight the importance of manufacturer-recommended pre-cleaning steps to remove gross soil before surface disinfection. Taken together, these data support the use of acid- and surfactant-containing commercial products for packing plant disinfection during a TAD virus outbreak event.","pmid":"29778199","doi":"10.1016/j.vetmic.2018.04.029","url":"https://pubmed.ncbi.nlm.nih.gov/29778199/"},{"id":1349,"title":"Impact of antimicrobial wipes compared with hypochlorite solution on environmental surface contamination in a health care setting: A double-crossover study.","authors":"Siani, Harsha; Wesgate, Rebecca; Maillard, Jean-Yves","year":2018,"date":"2018 Oct","journal":"American journal of infection control","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"OBJECTIVE: Antimicrobial wipes are increasingly used in health care settings. This study evaluates, in a clinical setting, the efficacy of sporicidal wipes versus a cloth soaked in a 1,000 ppm chlorine solution. INTERVENTION: A double-crossover study was performed on 2 different surgical and cardiovascular wards in a 1,000-bed teaching hospital over 29 weeks. The intervention period that consisted of surface decontamination with the preimpregnated wipe or cloth soaked in chlorine followed a 5-week baseline assessment of microbial bioburden on surfaces. Environmental samples from 11 surfaces were analyzed weekly for their microbial content. RESULTS: A total of 1,566 environmental samples and 1,591 ATP swabs were analyzed during the trial. Overall, there were significant differences in the recovery of total aerobic bacteria (P < .001), total anaerobic bacteria (P < .001), and ATP measurement (P < .001) between wards and between the different parts of the crossover study. Generally, the use of wipes produced the largest reduction in the total aerobic and anaerobic counts when compared with the baseline data or the use of 1,000 ppm chlorine. Collectively, the introduction of training plus daily wipe disinfection significantly reduced multidrug-resistant organisms recovered from surfaces. Reversion to using 1,000 ppm chlorine resulted in the number of sites positive for multidrug-resistant organisms rising again. CONCLUSIONS: This double-crossover study is the first controlled field trial comparison of using preimpregnated wipes versus cotton cloth dipped into a bucket of hypochlorite to decrease surface microbial bioburden. The results demonstrate the superiority of the preimpregnated wipes in significantly decreasing microbial bioburden from high-touch surfaces.","pmid":"29759641","doi":"10.1016/j.ajic.2018.03.020","url":"https://pubmed.ncbi.nlm.nih.gov/29759641/"},{"id":1352,"title":"[Enzymatic and bactericidal activity of monomeric and dimeric forms of myeloperoxidase].","authors":"Vakhrusheva, T V; Sokolov, A V; Kostevich, V A; Vasilyev, V B; Panasenko, O M","year":2018,"date":"2018 Mar","journal":"Biomeditsinskaia khimiia","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"This study was carried out to compare the enzymatic and bactericidal activity of mature, dimeric myeloperoxidase (MPO) and its monomeric form. Dimeric MPO was isolated from HL-60 cells. Hemi-MPO obtained from dimeric MPO by reductive cleavage of a disulfide bond between protomeric subunits was used as the monomeric form. Both peroxidase and halogenating (chlorinating) activities of MPO were assayed, each of them by two methods. Bactericidal activity of the MPO/Н2О2/Cl- system was tested using the Escherichia coli laboratory strain DH5a. No difference in the enzymatic and bactericidal activity between dimeric MPO and hemi-MPO was found. Both forms of the enzyme also did not differ in the resistance to HOCl, the main product of MPO. HOCl caused a dose-dependent decrease in peroxidase and chlorinating activity, and the pattern of this decrease was identical for dimeric MPO and hemi-MPO. At equal heme concentration, a somewhat higher bactericidal effect was observed for the hemi-MPO/Н2О2/Cl- system compared with the dimeric MPO/Н2О2/Cl- system. However, this is most likely not related to some specific property of hemi-MPO and can be accounted for by the higher probability of contacting between bacterial surface and hemi-MPO molecules due to their two-fold greater number relative to that of dimeric MPO molecules at the same heme concentration. By using Western-blotting with antibodies to MPO, we showed, for the first time, that the dimeric molecule of MPO could be cleaved into two monomeric subunits by HOCl, most probably due to oxidation of the disulfide bond between these subunits. This finding suggests that appearance in blood of MPO corresponding in mass to its monomer may result from the damage of dimeric MPO by reactive halogen species, especially upon their overproduction underlying oxidative/halogenative stress in inflammatory diseases.","pmid":"29723147","doi":"10.18097/PBMC20186402175","url":"https://pubmed.ncbi.nlm.nih.gov/29723147/"},{"id":1355,"title":"Evaluation of decontamination efficacy of commonly used antimicrobial interventions for beef carcasses against Shiga toxin-producing Escherichia coli.","authors":"Signorini, Marcelo; Costa, Magdalena; Teitelbaum, David; Restovich, Viviana; Brasesco, Hebe; García, Diego; Superno, Valeria; Petroli, Sandra; Bruzzone, Mariana; Arduini, Victor; Vanzini, Mónica; Sucari, Adriana; Suberbie, Germán; Maricel, Turina; Rodríguez, Ricardo; Leotta, Gerardo A","year":2018,"date":"2018 Aug","journal":"Meat science","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"In Argentina, Shiga toxin producing Escherichia coli (STEC) serogroups O157, O26, O103, O111, O145 and O121 are adulterant in ground beef. In other countries, the zero-tolerance approach to all STEC is implemented for chilled beef. Argentinean abattoirs are interested in implementing effective interventions against STEC on carcasses. Pre-rigor beef carcasses were used to determine whether nine antimicrobial strategies effectively reduced aerobic plate, coliform and E. coli counts and stx and eae gene prevalence. These strategies were: citric acid (2%; automated), acetic acid (2%; manual and automated), lactic acid (LA 2%; manual and automated), LA (3%; automated), electrolytically-generated hypochlorous acid (400 ppm; manual), hot water (82 °C; automated) and INSPEXX (0.2%; automated). Automated application of 2% LA after 30-60-min aeration and 3% LA at 55 °C were the most effective interventions. Automated application was more effective than manual application. Decontamination of beef carcasses through automated application of lactic acid and hot water would reduce public health risks associated with STEC contamination.","pmid":"29656275","doi":"10.1016/j.meatsci.2018.04.009","url":"https://pubmed.ncbi.nlm.nih.gov/29656275/"},{"id":1357,"title":"Topical Hypochlorite and Skin Acidification Improves Erythroderma of Omenn Syndrome.","authors":"Wat, Margaret; Olicker, Arielle; Meyerson, Howard; Nedorost, Susan; Paller, Amy S; Cooper, Kevin","year":2018,"date":"2018 Apr","journal":"Pediatrics","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"We describe a case of Omenn syndrome displaying exudative erythroderma and other characteristic features, including alopecia, absent B and naïve T cells, hyper immunoglobulin E levels, and eosinophilia. A pathogenic recombination-activating RAG1 homozygous genetic mutation confirmed the diagnosis. She required frequent antibiotics at both treatment and prophylactic doses, which alone did not control her erythroderma, but her high risk of infection precluded the use of systemic agents such as cyclosporine, which would further suppress her already severely compromised immune system. Thrice-weekly topical dilute hypochlorite compresses, combined with skin acidification with a low pH emollient, were initiated to control inflammation and for cutaneous bacterial prophylaxis. She demonstrated a marked improvement in her erythroderma within days after treatment initiation. Further improvement continued with the addition of systemic corticosteroids, with resolution of erythroderma after her first dose. This case reveals for the first time that dilute topical hypochlorite and skin pH restoration holds promise to control severe dermatitis associated with immunodeficiency and inflammatory syndromes with minimal side effects.","pmid":"29610161","doi":"10.1542/peds.2017-1249","url":"https://pubmed.ncbi.nlm.nih.gov/29610161/"},{"id":1358,"title":"Evaluation of substantivity of hypochlorous acid as an antiplaque agent: A randomized controlled trial.","authors":"Lafaurie, G I; Zaror, C; Díaz-Báez, D; Castillo, D M; De Ávila, J; Trujillo, T G; Calderón-Mendoza, J","year":2018,"date":"2018 Nov","journal":"International journal of dental hygiene","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"BACKGROUND: Hypochlorous acid (HOCl) is a non-antibiotic antimicrobial substance with significant effects on pathogenic oral micro-organisms. The effects of HOCl as an antiplaque agent have not been studied. OBJECTIVE: The aim of this study was to evaluate the substantivity of HOCl mouthwashes compared with chlorhexidine (CHX) rinses and a placebo. MATERIALS AND METHODS: A double-blind randomized controlled trial with 75 participants was conducted. Participants were divided into five groups using block randomization: 0.025% HOCl, 0.05% HOCl, 0.12% CHX, 0.2% CHX, and sterile water as a placebo. Participants were instructed to use each rinse solution for 30 seconds after dental prophylaxis. Samples of saliva were taken at baseline and after 30 seconds, 1, 3, 5 and 7 hours to assess substantivity, and bacterial viability was established by the fluorescence method. Visible plaque in all participants was assessed with the Turesky index at baseline and at 7 hours, and adverse events were also assessed. RESULTS: HOCl led to a 33% reduction in bacterial counts in the saliva after 30 seconds compared with a 58% reduction by CHX. HOCl has no substantivity, and bacterial counts returned to baseline after 1 hour. Placebo treatment led to the highest plaque count after 7 hours compared with the CHX and HOCl groups, although the differences were not significant. HOCl rinsing induced the highest percentages of unpleasant taste and dryness sensations. CONCLUSIONS: HOCl rinses have an initial effect on bacterial viability in saliva but have no substantivity. Other mechanisms may explain its antiplaque effect.","pmid":"29608039","doi":"10.1111/idh.12342","url":"https://pubmed.ncbi.nlm.nih.gov/29608039/"},{"id":1361,"title":"Drinking water microbiome assembly induced by water stagnation.","authors":"Ling, Fangqiong; Whitaker, Rachel; LeChevallier, Mark W; Liu, Wen-Tso","year":2018,"date":"2018 Jun","journal":"The ISME journal","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"What happens to tap water when you are away from home? Day-to-day water stagnation in building plumbing can potentially result in water quality deterioration (e.g., lead release or pathogen proliferation), which is a major public health concern. However, little is known about the microbial ecosystem processes in plumbing systems, hindering the development of biological monitoring strategies. Here, we track tap water microbiome assembly in situ, showing that bacterial community composition changes rapidly from the city supply following ~6-day stagnation, along with an increase in cell count from 10(3) cells/mL to upwards of 7.8 × 10(5) cells/mL. Remarkably, bacterial community assembly was highly reproducible in this built environment system (median Spearman correlation between temporal replicates = 0.78). Using an island biogeography model, we show that neutral processes arising from the microbial communities in the city water supply (i.e., migration and demographic stochasticity) explained the island community composition in proximal pipes (Goodness-of-fit = 0.48), yet declined as water approached the faucet (Goodness-of-fit = 0.21). We developed a size-effect model to simulate this process, which indicated that pipe diameter drove these changes by mediating the kinetics of hypochlorite decay and cell detachment, affecting selection, migration, and demographic stochasticity. Our study challenges current water quality monitoring practice worldwide which ignore biological growth in plumbing, and suggests the island biogeography model as a useful framework to evaluate building water system quality.","pmid":"29588495","doi":"10.1038/s41396-018-0101-5","url":"https://pubmed.ncbi.nlm.nih.gov/29588495/"},{"id":1364,"title":"Uric acid disrupts hypochlorous acid production and the bactericidal activity of HL-60 cells.","authors":"Carvalho, Larissa A C; Lopes, João P P B; Kaihami, Gilberto H; Silva, Railmara P; Bruni-Cardoso, Alexandre; Baldini, Regina L; Meotti, Flavia C","year":2018,"date":"2018 Jun","journal":"Redox biology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Uric acid is the end product of purine metabolism in humans and is an alternative physiological substrate for myeloperoxidase. Oxidation of uric acid by this enzyme generates uric acid free radical and urate hydroperoxide, a strong oxidant and potentially bactericide agent. In this study, we investigated whether the oxidation of uric acid and production of urate hydroperoxide would affect the killing activity of HL-60 cells differentiated into neutrophil-like cells (dHL-60) against a highly virulent strain (PA14) of the opportunistic pathogen Pseudomonas aeruginosa. While bacterial cell counts decrease due to dHL-60 killing, incubation with uric acid inhibits this activity, also decreasing the release of the inflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF- α). In a myeloperoxidase/Cl(-)/H(2)O(2) cell-free system, uric acid inhibited the production of HOCl and bacterial killing. Fluorescence microscopy showed that uric acid also decreased the levels of HOCl produced by dHL-60 cells, while significantly increased superoxide production. Uric acid did not alter the overall oxidative status of dHL-60 cells as measured by the ratio of reduced (GSH) and oxidized (GSSG) glutathione. Our data show that uric acid impairs the killing activity of dHL-60 cells likely by competing with chloride by myeloperoxidase catalysis, decreasing HOCl production. Despite diminishing HOCl, uric acid probably stimulates the formation of other oxidants, maintaining the overall oxidative status of the cells. Altogether, our results demonstrated that HOCl is, indeed, the main relevant oxidant against bacteria and deviation of myeloperoxidase activity to produce other oxidants hampers dHL-60 killing activity.","pmid":"29510342","doi":"10.1016/j.redox.2018.02.020","url":"https://pubmed.ncbi.nlm.nih.gov/29510342/"},{"id":1371,"title":"The aldehyde dehydrogenase AldA contributes to the hypochlorite defense and is redox-controlled by protein S-bacillithiolation in Staphylococcus aureus.","authors":"Imber, Marcel; Loi, Vu Van; Reznikov, Sylvia; Fritsch, Verena Nadin; Pietrzyk-Brzezinska, Agnieszka J; Prehn, Janek; Hamilton, Chris; Wahl, Markus C; Bronowska, Agnieszka K; Antelmann, Haike","year":2018,"date":"2018 May","journal":"Redox biology","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Staphylococcus aureus produces bacillithiol (BSH) as major low molecular weight (LMW) thiol which functions in thiol-protection and redox-regulation by protein S-bacillithiolation under hypochlorite stress. The aldehyde dehydrogenase AldA was identified as S-bacillithiolated at its active site Cys279 under NaOCl stress in S. aureus. Here, we have studied the expression, function, redox regulation and structural changes of AldA of S. aureus. Transcription of aldA was previously shown to be regulated by the alternative sigma factor SigmaB. Northern blot analysis revealed SigmaB-independent induction of aldA transcription under formaldehyde, methylglyoxal, diamide and NaOCl stress. Deletion of aldA resulted in a NaOCl-sensitive phenotype in survival assays, suggesting an important role of AldA in the NaOCl stress defense. Purified AldA showed broad substrate specificity for oxidation of several aldehydes, including formaldehyde, methylglyoxal, acetaldehyde and glycol aldehyde. Thus, AldA could be involved in detoxification of aldehyde substrates that are elevated under NaOCl stress. Kinetic activity assays revealed that AldA is irreversibly inhibited under H(2)O(2) treatment in vitro due to overoxidation of Cys279 in the absence of BSH. Pre-treatment of AldA with BSH prior to H(2)O(2) exposure resulted in reversible AldA inactivation due to S-bacillithiolation as revealed by activity assays and BSH-specific Western blot analysis. Using molecular docking and molecular dynamic simulation, we further show that BSH occupies two different positions in the AldA active site depending on the AldA activation state. In conclusion, we show here that AldA is an important target for S-bacillithiolation in S. aureus that is up-regulated under NaOCl stress and functions in protection under hypochlorite stress.","pmid":"29433022","doi":"10.1016/j.redox.2018.02.001","url":"https://pubmed.ncbi.nlm.nih.gov/29433022/"},{"id":1373,"title":"Enzymatic and bactericidal activity of myeloperoxidase in conditions of halogenative stress.","authors":"Vakhrusheva, Tatyana V; Grigorieva, Daria V; Gorudko, Irina V; Sokolov, Alexey V; Kostevich, Valeria A; Lazarev, Vassili N; Vasilyev, Vadim B; Cherenkevich, Sergey N; Panasenko, Oleg M","year":2018,"date":"2018 Oct","journal":"Biochemistry and cell biology = Biochimie et biologie cellulaire","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase (MPO), found mainly in neutrophils, is released in inflammation. MPO produces reactive halogen species (RHS), which are bactericidal agents. However, RHS overproduction, i.e., halogenative stress, can also damage host biomolecules, and MPO itself may be targeted by RHS. Therefore, we examined the susceptibility of MPO to inactivation by its primary products (HOCl, HOBr, HOSCN) and secondary products such as taurine monochloramine (TauCl) and taurine monobromamine (TauBr). MPO was dose-dependently inhibited up to complete inactivity by treatment with HOCl or HOBr. TauBr diminished the activity but did not eliminate it. TauCl had no effect. MPO became inactivated when producing HOCl or HOBr but not HOSCN. Taurine protected MPO against inactivation when MPO was catalyzing oxidation of Cl(-) to HOCl, whereas taurine failed to prevent inactivation when MPO was working with Br(-), either alone or in combination with Cl(-). SCN(-) interfered with HOCl-mediated MPO inhibition. UV-vis spectra showed that heme degradation is involved in HOCl- and HOBr-mediated MPO inactivation. A negative linear correlation between the remaining chlorinating activity of HOCl- or HOBr-modified MPO and Escherichia coli survival upon incubation with MPO/H(2)O(2)/Cl(-) was found. This study elucidated the possibility of MPO downregulation by MPO-derived RHS, which could counteract halogenative stress.","pmid":"29394490","doi":"10.1139/bcb-2017-0292","url":"https://pubmed.ncbi.nlm.nih.gov/29394490/"},{"id":1374,"title":"Chlorinated Lipids Elicit Inflammatory Responses in vitro and in vivo.","authors":"Yu, Hong; Wang, Meifang; Wang, Derek; Kalogeris, Theodore J; McHowat, Jane; Ford, David A; Korthuis, Ronald J","year":2019,"date":"2019 Jan","journal":"Shock (Augusta, Ga.)","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Increased endothelial cell adhesion molecule (ECAM) expression, leukocyte-endothelial cell adhesive interactions (LECA), platelet-endothelial cell adhesion (PECA), mast cell activation, production of reactive oxygen species (ROS), and microvascular permeability are hallmarks of the inflammatory response. The infiltration of inflammatory phagocytes is associated with myeloperoxidase (MPO)-dependent production of hypochlorous acid, a reactive chlorinating species that targets membrane lipids to produce halogenated lipids such as 2-chlorohexadecanal (2-ClHDA) and 2-chloropalmitic acid (2-ClPA). Whether these chlorinated lipids contribute to microcirculatory dysfunction is largely unknown. Thus, the objectives of this study were to determine if chlorinated lipids exposure induces such inflammatory responses in an in vitro model employing cultured human intestinal mesenteric vascular endothelial cells (HIMVEC), and in an in vivo model examining responses in small intestinal and mesenteric postcapillary venules of naive rats. Following the addition of either 2-ClPA or 2-ClHDA to the culture medium, HIMVEC displayed increased platelet and neutrophil adherence that was associated with elevated expression of ECAMs and increased permeability. In vivo, chlorinated lipid exposure significantly increased LECA, PECA, ROS production, and albumin leakage, inflammatory events that were associated with mast cell activation and increased tissue MPO activity and expression. Our data provide proof-of-principle that 2-ClPA and 2-ClHDA induce powerful proinflammatory responses both in vitro and in vivo, suggesting the possibility that these chlorinated lipid products of the MPO/ hydrogen peroxide /chloride system may contribute to inflammation noted in neutrophil-dependent, myeloperoxidase-mediated pathologic states such as ischemia/reperfusion, hemorrhagic shock, and sepsis.","pmid":"29394241","doi":"10.1097/SHK.0000000000001112","url":"https://pubmed.ncbi.nlm.nih.gov/29394241/"},{"id":1377,"title":"In Vitro Evaluation of a Hypochlorous Acid Hygiene Solution on Established Biofilms.","authors":"Romanowski, Eric G; Stella, Nicholas A; Yates, Kathleen A; Brothers, Kimberly M; Kowalski, Regis P; Shanks, Robert M Q","year":2018,"date":"2018 Nov","journal":"Eye & contact lens","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVES: The purpose of this study was to determine whether a commercial formulation of hypochlorous acid hygiene solution (0.01%), Avenova, can destroy existing biofilms formed by ocular clinical bacterial isolates, including blepharitis isolates of Staphylococcus aureus and coagulase-negative staphylococci, and a keratitis isolate of Pseudomonas aeruginosa. METHODS: Biofilms grown in bacterial growth media on disposable contact lens cases were challenged with hypochlorous acid hygiene solution. At various time points, surviving bacteria were quantified by serial dilution and colony counts. Staphylococcus aureus biofilms formed on glass were challenged using a hypochlorous acid hygiene solution and imaged using vital staining and confocal laser scanning microscopy. RESULTS: Bactericidal activity (≥3 Log10; 99.9%) was observed for all tested bacterial species after a 30-min exposure. Staphylococcus aureus biofilms had a bactericidal level of killing by 10 min (P<0.01), Staphylococcus capitis by 5 min (P<0.001), Staphylococcus epidermidis by 30 min (P<0.001), and P. aeruginosa by 10 min (P<0.01). Confocal microscopy and crystal violet staining analysis of bacterial biofilms treated with hypochlorous acid solution both demonstrated that biofilm bacteria were readily killed, but biofilm structure was largely maintained. CONCLUSIONS: Hypochlorous acid (0.01%) hygiene solution was able to achieve bactericidal levels of killing of bacteria in biofilms but did not disrupt biofilm structures. Susceptibility of tested staphylococcal blepharitis isolates varied by species, with S. capitis being the most susceptible and S. epidermidis being the least susceptible.","pmid":"29369234","doi":"10.1097/ICL.0000000000000456","url":"https://pubmed.ncbi.nlm.nih.gov/29369234/"},{"id":1382,"title":"The effect of HOCl-induced modifications on phosphatase and tensin homologue (PTEN) structure and function.","authors":"Verrastro, Ivan; Tveen-Jensen, Karina; Spickett, Corinne M; Pitt, Andrew R","year":2018,"date":"2018 Feb","journal":"Free radical research","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Oxidation by reactive species can cause changes in protein function and affect cell signalling pathways. Phosphatase and tensin homologue (PTEN) is a negative regulator of the PI3K/AKT pathway and is known to be inhibited by oxidation, but its oxidation by the myeloperoxidase-derived oxidant hypochlorous acid (HOCl) has not previously been investigated. PTEN-GST was treated with HOCl:protein ratios from 15:1 to 300:1. Decreases in PTEN phosphatase activity were observed at treatment ratios of 60:1 and higher, which correlated with the loss of the intact protein band and appearance of high molecular weight aggregates in SDS-PAGE. LC-MSMS was used to map oxidative modifications (oxPTMs) in PTEN-GST tryptic peptides and label-free quantitative proteomics used to determine their relative abundance. Twenty different oxPTMs of PTEN were identified, of which 14 were significantly elevated upon HOCl treatment in a dose-dependent manner. Methionine and cysteine residues were the most heavily oxidised; the percentage modification depended on their location in the sequence, reflecting differences in susceptibility. Other modifications included tyrosine chlorination and dichlorination, and hydroxylations of tyrosine, tryptophan, and proline. Much higher levels of oxidation occurred in the protein aggregates compared to the monomeric protein for certain methionine and tyrosine residues located in the C2 and C-terminal domains, suggesting that their oxidation promoted protein destabilisation and aggregation; many of the residues modified were classified as buried according to their solvent accessibility. This study provides novel information on the susceptibility of PTEN to the inflammatory oxidant HOCl and its effects on the structure and activity of the protein.","pmid":"29298524","doi":"10.1080/10715762.2018.1424333","url":"https://pubmed.ncbi.nlm.nih.gov/29298524/"},{"id":1383,"title":"Hypochlorous Acid Promoted Platinum Drug Chemotherapy by Myeloperoxidase-Encapsulated Therapeutic Metal Phenolic Nanoparticles.","authors":"Dai, Yunlu; Cheng, Siyuan; Wang, Zhongliang; Zhang, Ruili; Yang, Zhen; Wang, Jingjing; Yung, Bryant C; Wang, Zhantong; Jacobson, Orit; Xu, Can; Ni, Qianqian; Yu, Guocan; Zhou, Zijian; Chen, Xiaoyuan","year":2018,"date":"2018 Jan 23","journal":"ACS nano","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"This study applies in situ production of hypochlorous acid (HOCl) to improve the therapeutic efficacy of platinum drugs. The phagocytic enzyme myeloperoxidase (MPO) is coated with two functional polyphenol derivatives (platinum prodrug polyphenols and PEG polyphenols) and ferric ion by metal phenolic coordination, which can shield MPO from degradation by other compounds in the blood. Moreover, the platinum prodrug can be reduced to cisplatin in cells and produce hydrogen peroxide (H(2)O(2)). The MPO catalyzes the conversion of H(2)O(2) to HOCl in the intercellular environment. The as-prepared MPO Pt PEG nanoparticles (MPP NPs) can be employed as a reactive oxygen species cascade bioreaction to enhance platinum drug therapy. The MPP NPs show prolonged blood circulation and high tumor accumulation as evidenced by (89)Zr-based positron emission tomography imaging. The MPP NPs effectively inhibit tumor growth in vivo. As a first-in-class platform to harness the highly toxic HOCl in nanomedicine for cancer therapy, this strategy may open doors for further development of progressive therapeutic systems.","pmid":"29293312","doi":"10.1021/acsnano.7b06852","url":"https://pubmed.ncbi.nlm.nih.gov/29293312/"},{"id":1387,"title":"Preliminary Results of the Use of a Stabilized Hypochlorous Acid Solution in the Management of Ralstonia Pickettii Biofilm on Silicone Breast Implants.","authors":"Brindle, C Tod; Porter, Steve; Bijlani, Kiran; Arumugam, Sridhar; Matias, Rowena; Najafi, Ron; Fisher, Jack","year":2018,"date":"2018 May 15","journal":"Aesthetic surgery journal","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: Ralstonia Pickettii biofilms are associated with pocket infections following breast implant surgeries. Biofilm protects bacteria most topically applied antimicrobial irrigations. OBJECTIVES: To evaluate the effectiveness of four antimicrobial solutions on the planktonic form and established biofilm of Ralstonia Pickettii grown on 3 different types of silicone breast implants. METHODS: Time kill assays at clinical concentrations of chlorhexidine gluconate, povidone iodine, triple-antibiotic solution, and a 0.025% hypochlorous acid solution stabilized in amber glass were evaluated. Normal saline was the control. Three types of silicone implants, two with a textured surface and one smooth surface, were selected. Planktonic assays were performed after implants were soaked for one, five, 30, and 120 minute time points. Biofilm assays were performed after 5 and 120 minutes of implant soak time. Both tests evaluated cell-forming units (CFU/mL). RESULTS: Triple antibiotic solution had no effect on R. pickettii and was dropped from the study. Remaining solutions showed total kill of planktonic bacteria at one minute. Saline control showed no significant effect on biofilm as anticipated. Stabilized hypochlorous acid was the only solution tested capable of eradicating R. pickettii biofilm on all implant surfaces tested within the first five minute soak time. CONCLUSIONS: Noncytotoxic, 0.025% hypochlorous acid in normal saline, stabilized in amber glass, successfully eradicated Ralstonia pickettii in planktonic and mature biofilm on three types of silicone implants during initial five minute soak time and may be the preferred antimicrobial solution for pocket lavage. This preliminary study requires further investigation. Leaching and implant compatibility testing is currently in progress.","pmid":"29240873","doi":"10.1093/asj/sjx229","url":"https://pubmed.ncbi.nlm.nih.gov/29240873/"},{"id":1388,"title":"Redox-Sensing Under Hypochlorite Stress and Infection Conditions by the Rrf2-Family Repressor HypR in Staphylococcus aureus.","authors":"Loi, Vu Van; Busche, Tobias; Tedin, Karsten; Bernhardt, Jörg; Wollenhaupt, Jan; Huyen, Nguyen Thi Thu; Weise, Christoph; Kalinowski, Jörn; Wahl, Markus C; Fulde, Marcus; Antelmann, Haike","year":2018,"date":"2018 Sep 1","journal":"Antioxidants & redox signaling","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"AIMS: Staphylococcus aureus is a major human pathogen and has to cope with reactive oxygen and chlorine species (ROS, RCS) during infections, which requires efficient protection mechanisms to avoid destruction. Here, we have investigated the changes in the RNA-seq transcriptome by the strong oxidant sodium hypochlorite (NaOCl) in S. aureus USA300 to identify novel redox-sensing mechanisms that provide protection under infection conditions. RESULTS: NaOCl stress caused an oxidative stress response in S. aureus as indicated by the induction of the PerR, QsrR, HrcA, and SigmaB regulons in the RNA-seq transcriptome. The hypR-merA (USA300HOU_0588-87) operon was most strongly upregulated under NaOCl stress, which encodes for the Rrf2-family regulator HypR and the pyridine nucleotide disulfide reductase MerA. We have characterized HypR as a novel redox-sensitive repressor that controls MerA expression and directly senses and responds to NaOCl and diamide stress via a thiol-based mechanism in S. aureus. Mutational analysis identified Cys33 and the conserved Cys99 as essential for NaOCl sensing, while Cys99 is also important for repressor activity of HypR in vivo. The redox-sensing mechanism of HypR involves Cys33-Cys99 intersubunit disulfide formation by NaOCl stress both in vitro and in vivo. Moreover, the HypR-controlled flavin disulfide reductase MerA was shown to protect S. aureus against NaOCl stress and increased survival in J774A.1 macrophage infection assays. Conclusion and Innovation: Here, we identified a new member of the widespread Rrf2 family as redox sensor of NaOCl stress in S. aureus that uses a thiol/disulfide switch to regulate defense mechanisms against the oxidative burst under infections in S. aureus. Antioxid. Redox Signal. 29, 615-636.","pmid":"29237286","doi":"10.1089/ars.2017.7354","url":"https://pubmed.ncbi.nlm.nih.gov/29237286/"},{"id":1390,"title":"Hypochlorous Acid Versus Povidone-Iodine Containing Irrigants: Which Antiseptic is More Effective for Breast Implant Pocket Irrigation?","authors":"Hu, Honghua; Sleiman, Janine; Johani, Khalid; Vickery, Karen","year":2018,"date":"2018 Jun 13","journal":"Aesthetic surgery journal","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"BACKGROUND: Capsular contracture induced by chronic subclinical infection is a major cause of poor outcomes and reoperation in breast implant surgery. The use of pocket irrigation with antiseptic/antibiotic has been shown to reduce the incidence of contracture. A new formulation of hypochlorous acid solution PhaseOne has been proposed as potential agent for irrigation. OBJECTIVES: This study aimed to test the efficacy of hypochlorous acid solution PhaseOne for use in breast pocket irrigation as an alternative to povidone iodine solution Betadine. METHODS: The efficacy of PhaseOne, a hypochlorous acid formulated wound and skin cleanser, was tested in vitro against planktonic and biofilm Staphylococcus aureus with or without biological soil and in an implant attachment assay. Its activity was compared with Betadine containing 10% povidone iodine. RESULTS: Our findings showed that PhaseOne was unable to eradicate planktonic and/or biofilm S. aureus in the presence of either tryptone soy broth or bovine calf serum (protein soil) in a variety of in vitro assays. CONCLUSIONS: We advise that povidone iodine containing irrigants are superior to hypochlorous acid containing irrigants in the clinical setting and should remain the recommended solution for pocket irrigation to reduce bacterial contamination at breast implants surgery.","pmid":"29190321","doi":"10.1093/asj/sjx213","url":"https://pubmed.ncbi.nlm.nih.gov/29190321/"},{"id":1393,"title":"Comparative study of dissolved organic matter generated from activated sludge during exposure to hypochlorite, hydrogen peroxide, acid and alkaline: Implications for on-line chemical cleaning of MBR.","authors":"Cai, Weiwei; Liu, Yu","year":2018,"date":"2018 Feb","journal":"Chemosphere","category":"Materials & industrial applications","evidence":"Journal article / other","relevance":"Medium","abstract":"Although on-line chemical cleaning has been extensively employed for maintaining the MBR permeability, little attention has been given to the negative impacts of such prevalent membrane cleaning practice. This study thus comparatively investigated the potential release of dissolved organic matter (DOM) from activated sludge upon the exposure to different kinds of frequently-used cleaning reagents, i.e. NaClO, H(2)O(2), HCl and NaOH. It was found that NaClO at 50 and 80 mg L(-1) triggered significant release of DOM, while NaOH strongly promoted soluble nitrogen release. However, the DOM generation induced by H(2)O(2) in the range of 0-80 mg L(-1) was nearly negligible. The combined analysis by EEM-PARAFAC and LC-OCD-OND further revealed that NaClO-triggered DOM mainly originated from the breakdown of humic substances and other small humics with molecular weight (MW) less than 500 Da. In contrast, proteins and other biopolymers with higher MW highly contributed to DOM induced by NaOH. Most of DOM detected in this study belonged to low molecular weight (LMW) substances, which were not considered readily biodegradable or physically retainable by microfiltration membrane. It appears from this study that DOM generated from suspended activated sludge during membrane cleaning with different chemicals should be taken into serious consideration when water recycle and reuse are concerned.","pmid":"29145090","doi":"10.1016/j.chemosphere.2017.11.032","url":"https://pubmed.ncbi.nlm.nih.gov/29145090/"},{"id":1394,"title":"Disruption of Biofilms and Neutralization of Bacteria Using Hypochlorous Acid Solution: An In Vivo and In Vitro Evaluation.","authors":"Day, Anna; Alkhalil, Abdulnaser; Carney, Bonnie C; Hoffman, Hilary N; Moffatt, Lauren T; Shupp, Jeffrey W","year":2017,"date":"2017 Dec","journal":"Advances in skin & wound care","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVES: The aims of this study were to assess the effectiveness of a hypochlorous acid-based wound cleanser (Vashe Wound Solution [VWS], SteadMed Medical, Fort Worth, Texas) in disrupting methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa biofilms relative to other cleansers using an in vitro collagen biofilm model and to evaluate cleansers' cytotoxicity. The bioburden reduction of venous stasis wounds by VWS and another cleanser was evaluated. METHODS: Plates coated with collagen films incubated with active bacteria cultures to yield biofilm mimics were treated with VWS, 1% and 10% povidone-iodine (PI), 0.05% chlorhexidine wound solution (CWS), or normal saline for 3 or 10 minutes. Biofilms were then analyzed for biomass density using a crystal violet assay, quantitative cultures, and fluorescent microscopy. Cytotoxicity was measured using neutral red uptake by primary human dermal fibroblasts. Pre- and postcleansing exudates and swab samples obtained from venous stasis wounds of patients were processed and plated on a series of selective agar plates for bacteria typing and quantification. RESULTS: All agents tested significantly neutralized methicillin-resistant S aureus and P aeruginosa biofilms compared with saline control as assessed by crystal violet assay and fluorescent microscopy assays. Undiluted VWS was significantly less cytotoxic compared with 1% PI, CWS, and 10% PI (in increasing order of cytotoxicity). There was no significant difference in bacterial reduction in wounds after treatment with VWS or CWS for any type of bacteria examined using selective media. In wounds that were treated with VWS or CWS, there was a similar percentage reduction in bacterial colony-forming units from precleansing levels when plated on tryptic soy agar, MacConkey, streptococcal, and mannitol salt agar plates. Plates treated with CWS trended toward higher bacterial reduction on nonselective and gram-negative agars, whereas VWS trended toward higher bacterial reduction in Streptococcus-selective agars. CONCLUSIONS: These findings support the use of VWS in the treatment of wounds with biofilms and to reduce the bioburden of venous stasis ulcers. While VWS-treated biofilms had higher biomass than CWS- and saline-treated biofilms, most of the cellular component was not viable. Ultimately, VWS had a similar effectiveness to CWS in eliminating bacteria but with lower cytotoxicity.","pmid":"29140837","doi":"10.1097/01.ASW.0000526607.80113.66","url":"https://pubmed.ncbi.nlm.nih.gov/29140837/"},{"id":1395,"title":"Oxidation of C-reactive protein by hypochlorous acid leads to the formation of potent platelet activator.","authors":"Boncler, Magdalena; Kehrel, Beate; Szewczyk, Rafał; Stec-Martyna, Emilia; Bednarek, Radosław; Brodde, Martin; Watala, Cezary","year":2018,"date":"2018 Feb","journal":"International journal of biological macromolecules","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"We examined the structural and functional consequences of oxidative modification of C-reactive protein (CRP) by hypochlorous acid (HOCl), which can be generated in vivo via the myeloperoxidase/H(2)O(2)/Cl(-) system. HOCl exposure resulted in the oxidation and chlorination of CRP amino acid residues, leading to protein unfolding, greater surface hydrophobicity and the formation of aggregates. After treatment of isolated platelets with 50μg/ml HOCl-CRP, the modified CRP significantly stimulated platelet activation (over 10-fold increase in the fraction of CD62-positive platelets compared to controls, P<0.008), enhanced deposition of platelets onto immobilized fibrinogen (two-fold rise in platelet adhesion compared to controls, P<0.0001), and induced platelet aggregation by up to 79.5%. The ability of HOCl-CRP to interact with several platelet receptors (TLR-4, GPIIbIIIa) and plasma proteins (C1q, IgG) strongly indicates that HOCl-modification leads to structural changes of CRP resulting in the formation of new ligand binding sites, which is characteristic of the monomeric form of CRP exerting pro-inflammatory effects on a variety of cells. Overall, the oxidation of native CRP by HOCl seems to represent an alternative mechanism of CRP modification, by which CRP reveals its pro-inflammatory and pro-thrombotic properties, and as such, it might be of causal relevance in the pathogenesis of atherosclerosis.","pmid":"29111269","doi":"10.1016/j.ijbiomac.2017.10.159","url":"https://pubmed.ncbi.nlm.nih.gov/29111269/"},{"id":1397,"title":"Isomer distribution of hydroxyoctadecadienoates (HODE) and hydroxyeicosatetraenoates (HETE) produced in the plasma oxidation mediated by peroxyl radical, peroxynitrite, hypochlorite, 15-lipoxygenase, and singlet oxygen.","authors":"Umeno, Aya; Morita, Mayuko; Yoshida, Yasukazu; Naito, Yuji; Niki, Etsuo","year":2017,"date":"2017 Dec 1","journal":"Archives of biochemistry and biophysics","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Free and ester forms of unsaturated fatty acids and cholesterol are oxidized in vivo by multiple oxidants to give diverse products. Some lipid oxidation is mediated by enzymes to selectively give specific products, while others proceed randomly to produce mixtures of many kinds of regioisomers and stereoisomers. The efficacy of antioxidants against lipid oxidation depends on the nature of the oxidants and therefore the identification of oxidant is important for understanding the roles and effects of lipid oxidation and antioxidants in vivo. In the present study, the isomer distribution of hydro(pero)xyoctadecadienoates (H(p)ODEs) and hydro(pero)xyeicosatetraenoates (H(p)ETEs), the most abundant lipid oxidation products found in human plasma, produced in the oxidation of plasma by peroxyl radicals, peroxynitrite, hypochlorite, 15-lipoxygenase, and singlet oxygen were examined. It was shown that 9- and 13-(E,E)-HODEs, 13(S)-(Z,E)-HODE, and 10- and 12-(Z,E)-HODEs were specific lipid oxidation products by free radical, 15-lipoxygenase, and singlet oxygen, respectively. The isomer distribution of HODEs produced by peroxynitrite was similar to that by peroxyl radical, suggesting that the peroxynitrite mediated lipid oxidation proceeds by free radical mechanisms. The production of HODEs and HETEs by hypochlorite was very small. HODEs may be a better biomarker than HETEs since linoleates are oxidized by simpler mechanisms than arachidonates and all the HODEs isomers can be quantified more easily. These products may be used as specific biomarkers for the identification of responsible oxidants and for the assessment of oxidant-specific lipid oxidation levels and effects of antioxidants in vivo.","pmid":"29097313","doi":"10.1016/j.abb.2017.10.023","url":"https://pubmed.ncbi.nlm.nih.gov/29097313/"},{"id":1398,"title":"Preparation of an Efficient Ratiometric Fluorescent Nanoprobe (m-CDs@[Ru(bpy)(3)](2+)) for Visual and Specific Detection of Hypochlorite on Site and in Living Cells.","authors":"Zhan, Yuanjin; Luo, Fang; Guo, Longhua; Qiu, Bin; Lin, Yuhong; Li, Juan; Chen, Guonan; Lin, Zhenyu","year":2017,"date":"2017 Nov 22","journal":"ACS sensors","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorite (ClO(-)) is one of the most important reactive oxygen species (ROS), which plays an important role in sustaining human innate immunity during microbial invasion. Moreover, ClO(-) is a powerful oxidizer for water treatment. The safety of drinking water is closely related to its content. Herein, m-phenylenediamine (mPD) is used as a precursor to prepare carbon dots (named m-CDs) with highly fluorescent quantum yield (31.58% in water), and our investigation shows that the strong fluorescent emission of m-CDs can be effectively quenched by ClO(-). Based on these findings, we developed a novel fluorescent nanoprobe (m-CDs) for highly selective detection of ClO(-). The linear range was from 0.05 to 7 μM (R(2) = 0.998), and the limit of detection (S/N = 3) was as low as 0.012 μM. Moreover, a portable agarose hydrogel solid matrix-based ratiometric fluorescent nanoprobe (m-CDs@[Ru(bpy)(3)](2+)) sensor was subsequently developed for visual on-site detection of ClO(-) with the naked eyes under a UV lamp, suggesting its potential in practical application with low cost and excellent performance in water quality monitoring. Additionally, intracellular detection of exogenous ClO(-) was demonstrated via ratiometric imaging microscopy.","pmid":"29094932","doi":"10.1021/acssensors.7b00601","url":"https://pubmed.ncbi.nlm.nih.gov/29094932/"},{"id":1399,"title":"Intracavity lavage and wound irrigation for prevention of surgical site infection.","authors":"Norman, Gill; Atkinson, Ross A; Smith, Tanya A; Rowlands, Ceri; Rithalia, Amber D; Crosbie, Emma J; Dumville, Jo C","year":2017,"date":"2017 Oct 30","journal":"The Cochrane database of systematic reviews","category":"Human clinical & healthcare","evidence":"Systematic review / meta-analysis","relevance":"Medium","abstract":"BACKGROUND: Surgical site infections (SSIs) are wound infections that occur after an operative procedure. A preventable complication, they are costly and associated with poorer patient outcomes, increased mortality, morbidity and reoperation rates. Surgical wound irrigation is an intraoperative technique, which may reduce the rate of SSIs through removal of dead or damaged tissue, metabolic waste, and wound exudate. Irrigation can be undertaken prior to wound closure or postoperatively. Intracavity lavage is a similar technique used in operations that expose a bodily cavity; such as procedures on the abdominal cavity and during joint replacement surgery. OBJECTIVES: To assess the effects of wound irrigation and intracavity lavage on the prevention of surgical site infection (SSI). SEARCH METHODS: In February 2017 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase and EBSCO CINAHL Plus. We also searched three clinical trials registries and references of included studies and relevant systematic reviews. There were no restrictions on language, date of publication or study setting. SELECTION CRITERIA: We included all randomised controlled trials (RCTs) of participants undergoing surgical procedures in which the use of a particular type of intraoperative washout (irrigation or lavage) was the only systematic difference between groups, and in which wounds underwent primary closure. The primary outcomes were SSI and wound dehiscence. Secondary outcomes were mortality, use of systemic antibiotics, antibiotic resistance, adverse events, re-intervention, length of hospital stay, and readmissions. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for inclusion at each stage. Two review authors also undertook data extraction, assessment of risk of bias and GRADE assessment. We calculated risk ratios or differences in means with 95% confidence intervals where possible. MAIN RESULTS: We included 59 RCTs with 14,738 participants. Studies assessed comparisons between irrigation and no irrigation, between antibacterial and non-antibacterial irrigation, between different antibiotics, different antiseptics or different non-antibacterial agents, or between different methods of irrigation delivery. No studies compared antiseptic with antibiotic irrigation. Surgical site infectionIrrigation compared with no irrigation (20 studies; 7192 participants): there is no clear difference in risk of SSI between irrigation and no irrigation (RR 0.87, 95% CI 0.68 to 1.11; I(2) = 28%; 14 studies, 6106 participants). This would represent an absolute difference of 13 fewer SSIs per 1000 people treated with irrigation compared with no irrigation; the 95% CI spanned from 31 fewer to 10 more SSIs. This was low-certainty evidence downgraded for risk of bias and imprecision.Antibacterial irrigation compared with non-antibacterial irrigation (36 studies, 6163 participants): there may be a lower incidence of SSI in participants treated with antibacterial irrigation compared with non-antibacterial irrigation (RR 0.57, 95% CI 0.44 to 0.75; I(2) = 53%; 30 studies, 5141 participants). This would represent an absolute difference of 60 fewer SSIs per 1000 people treated with antibacterial irrigation than with non-antibacterial (95% CI 35 fewer to 78 fewer). This was low-certainty evidence downgraded for risk of bias and suspected publication bias.Comparison of irrigation of two agents of the same class (10 studies; 2118 participants): there may be a higher incidence of SSI in participants treated with povidone iodine compared with superoxidised water (Dermacyn) (RR 2.80, 95% CI 1.05 to 7.47; low-certainty evidence from one study, 190 participants). This would represent an absolute difference of 95 more SSIs per 1000 people treated with povidone iodine than with superoxidised water (95% CI 3 more to 341 more). All other comparisons found low- or very low-certainty evidence of no clear difference between groups.Comparison of two irrigation techniques: two studies compared standard (non-pulsed) methods with pulsatile methods. There may, on average, be fewer SSIs in participants treated with pulsatile methods compared with standard methods (RR 0.34, 95% CI 0.19 to 0.62; I(2) = 0%; two studies, 484 participants). This would represent an absolute difference of 109 fewer SSIs occurring per 1000 with pulsatile irrigation compared with standard (95% CI 62 fewer to 134 fewer). This was low-certainty evidence downgraded twice for risks of bias across multiple domains. Wound dehiscenceFew studies reported wound dehiscence. No comparison had evidence for a difference between intervention groups. This included comparisons between irrigation and no irrigation (one study, low-certainty evidence); antibacterial and non-antibacterial irrigation (three studies, very low-certainty evidence) and pulsatile and standard irrigation (one study, low-certainty evidence). Secondary outcomesFew studies reported outcomes such as use of systemic antibiotics and antibiotic resistance and they were poorly and incompletely reported. There was limited reporting of mortality; this may have been partially due to failure to specify zero events in participants at low risk of death. Adverse event reporting was variable and often limited to individual event types. The evidence for the impact of interventions on length of hospital stay was low or moderate certainty; where differences were seen they were too small to be clinically important. AUTHORS' CONCLUSIONS: The evidence base for intracavity lavage and wound irrigation is generally of low certainty. Therefore where we identified a possible difference in the incidence of SSI (in comparisons of antibacterial and non-antibacterial interventions, and pulsatile versus standard methods) these should be considered in the context of uncertainty, particularly given the possibility of publication bias for the comparison of antibacterial and non-antibacterial interventions. Clinicians should also consider whether the evidence is relevant to the surgical populations under consideration, the varying reporting of other prophylactic antibiotics, and concerns about antibiotic resistance.We did not identify any trials that compared an antibiotic with an antiseptic. This gap in the direct evidence base may merit further investigation, potentially using network meta-analysis; to inform the direction of new primary research. Any new trial should be adequately powered to detect a difference in SSIs in eligible participants, should use robust research methodology to reduce the risks of bias and internationally recognised criteria for diagnosis of SSI, and should have adequate duration and follow-up.","pmid":"29083473","doi":"10.1002/14651858.CD012234.pub2","url":"https://pubmed.ncbi.nlm.nih.gov/29083473/"},{"id":1401,"title":"Neutrophil granule proteins generate bactericidal ammonia chloramine on reaction with hydrogen peroxide.","authors":"Green, Jessie N; Chapman, Anna L P; Bishop, Cynthia J; Winterbourn, Christine C; Kettle, Anthony J","year":2017,"date":"2017 Dec","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The neutrophil enzyme, myeloperoxidase, by converting hydrogen peroxide (H(2)O(2)) and chloride to hypochlorous acid (HOCl), provides important defense against ingested micro-organisms. However, there is debate about how efficiently HOCl is produced within the phagosome and whether its reactions with phagosomal constituents influence the killing mechanism. The phagosome is a small space surrounding the ingested organism, into which superoxide, H(2)O(2) and high concentrations of proteins from cytoplasmic granules are released. Previous studies imply that HOCl is produced in the phagosome, but a large proportion should react with proteins before reaching the microbe. To mimic these conditions, we subjected neutrophil granule extract to sequential doses of H(2)O(2). Myeloperoxidase in the extract converted all the H(2)O(2) to HOCl, which reacted with the granule proteins. 3-Chlorotyrosine, protein carbonyls and large amounts of chloramines were produced. At higher doses of H(2)O(2), the extract developed potent bactericidal activity against Staphylococcus aureus. This activity was due to ammonia monochloramine, formed as a secondary product from protein chloramines and dichloramines. Isolated myeloperoxidase and elastase also became bactericidal when modified with HOCl and antibacterial activity was seen with a range of species. Comparison of levels of protein modification in the extract and in phagosomes implies that a relatively low proportion of phagosomal H(2)O(2) would be converted to HOCl, but there should be sufficient for substantial protein chloramine formation and some breakdown to ammonia monochloramine. It is possible that HOCl could kill ingested bacteria by an indirect mechanism involving protein oxidation and monochloramine formation.","pmid":"29055823","doi":"10.1016/j.freeradbiomed.2017.10.343","url":"https://pubmed.ncbi.nlm.nih.gov/29055823/"},{"id":1404,"title":"Myofibrillar protein oxidation affects filament charges, aggregation and water-holding.","authors":"Bao, Yulong; Boeren, Sjef; Ertbjerg, Per","year":2018,"date":"2018 Jan","journal":"Meat science","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Hypochlorous acid (HClO) is a strong oxidant that is able to mediate protein oxidation. In order to study the effect of oxidation on charges, aggregation and water-holding of myofibrillar proteins, extracted myofibrils were oxidized by incubation with different concentrations of HClO (0, 1, 5, and 10mM). Loss of free thiols, loss of histidine and formation of carbonyls were greater with increasing oxidation level and the particle size increased. Water-holding in the 5 and 10mM HClO groups were greater than in the non-oxidized control. Isoelectric focusing (IEF) showed that the isoelectric point (pI) of oxidized proteins were lower compared to non-oxidized ones. The lower pI values of oxidized proteins suggests that oxidation increased the overall net negative charge of myofibrillar proteins solubilized for IEF. Here we propose a hypothesis that oxidation-induced increase in net negative charges is the driving force for improved water-holding in myofibrils, whereas protein cross-linking and aggregation have an opposing effect by decreasing the water-holding.","pmid":"28968552","doi":"10.1016/j.meatsci.2017.09.011","url":"https://pubmed.ncbi.nlm.nih.gov/28968552/"},{"id":1412,"title":"Low-density lipoprotein modified by myeloperoxidase oxidants induces endothelial dysfunction.","authors":"Abdo, Adrian I; Rayner, Benjamin S; van Reyk, David M; Hawkins, Clare L","year":2017,"date":"2017 Oct","journal":"Redox biology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Low-density lipoprotein (LDL) modified by hypochlorous acid (HOCl) produced by myeloperoxidase (MPO) is present in atherosclerotic lesions, where it is implicated in the propagation of inflammation and acceleration of lesion development by multiple pathways, including the induction of endothelial dysfunction. Thiocyanate (SCN(-)) ions are utilised by MPO to produce the oxidant hypothiocyanous acid (HOSCN), which reacts with LDL in a different manner to HOCl. Whilst the reactivity of HOCl-modified LDL has been previously studied, the role of HOSCN in the modification of LDL in vivo is poorly defined, although emerging evidence suggests that these particles have distinct biological properties. This is important because elevated plasma SCN(-) is linked with both the propagation and prevention of atherosclerosis. In this study, we demonstrate that both HOSCN- and HOCl-modified LDL inhibit endothelium-mediated vasorelaxation ex vivo in rat aortic ring segments. In vitro experiments with human coronary artery endothelial cells show that HOSCN-modified LDL decreases in the production of nitric oxide (NO(•)) and induces the loss of endothelial nitric oxide synthase (eNOS) activity. This occurs to a similar extent to that seen with HOCl-modified LDL. In each case, these effects are related to eNOS uncoupling, rather than altered expression, phosphorylation or cellular localisation. Together, these data provide new insights into role of MPO and LDL modification in the induction of endothelial dysfunction, which has implications for both the therapeutic use of SCN(-) within the setting of atherosclerosis and for smokers, who have elevated plasma levels of SCN(-), and are more at risk of developing cardiovascular disease.","pmid":"28818791","doi":"10.1016/j.redox.2017.08.004","url":"https://pubmed.ncbi.nlm.nih.gov/28818791/"},{"id":1415,"title":"Pseudomonas aeruginosa defense systems against microbicidal oxidants.","authors":"Groitl, Bastian; Dahl, Jan-Ulrik; Schroeder, Jeremy W; Jakob, Ursula","year":2017,"date":"2017 Nov","journal":"Molecular microbiology","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"The most abundant oxidants controlling bacterial colonization on mucosal barrier epithelia are hypochlorous acid (HOCl), hypobromous acid (HOBr) and hypothiocyanous acid (HOSCN). All three oxidants are highly antimicrobial but little is known about their relative efficacies, their respective cellular targets, or what specific responses they elicit in bacteria. To address these important questions, we directly tested the individual oxidants on the virulent Pseudomonas aeruginosa strain PA14. We discovered that HOCl and HOBr work almost interchangeably, impacting non-growing bacterial cultures more significantly than actively growing bacteria, and eliciting similar stress responses, including the heat shock response. HOSCN treatment is distinctly different, affecting primarily actively growing PA14 and evoking stress responses suggestive of membrane damage. What all three oxidants have in common, however, is their ability to cause substantial protein aggregation. This effect became particularly obvious in strains lacking polyphosphate, a newly recognized chemical chaperone. Treatment of PA14 with the FDA-approved anti-inflammatory drug mesalamine, which has recently been shown to attenuate polyP production in a wide range of bacteria, effectively decreased the resistance of PA14 toward all three oxidants, suggesting that we have discovered a novel, targetable defense system in P. aeruginosa.","pmid":"28795780","doi":"10.1111/mmi.13768","url":"https://pubmed.ncbi.nlm.nih.gov/28795780/"},{"id":1425,"title":"New Insights into the Stability of Silver Sulfide Nanoparticles in Surface Water: Dissolution through Hypochlorite Oxidation.","authors":"Li, Lingxiangyu; Xu, Zhenlan; Wimmer, Andreas; Tian, Qinghua; Wang, Xinping","year":2017,"date":"2017 Jul 18","journal":"Environmental science & technology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Silver sulfide nanoparticles (Ag(2)SNPs) are considered to be stable in the environment due to the extreme low solubility of Ag(2)S (K(sp): 6.3 × 10(-50)). Little is known about the stability of Ag(2)SNPs in surface water disinfected with aqueous chlorine, one of the globally most used disinfectants. Our results suggested that both uncoated and polyvinylpyrrolidone (PVP)-coated Ag(2)SNPs (100 μg/L) underwent dissolution in surface water disinfected with aqueous chlorine at a dose of 4 mg/L, showing the highest dissolved silver ion concentrations of 22.3 and 10.5 μg/L within 45 min, respectively. The natural organic matter (NOM) and dissolved oxygen (DO) posed effects on the Ag(2)SNPs dissolution by chlorine; NOM accelerated Ag(2)SNPs dissolution while DO reduced the rate and extent of Ag(2)SNPs dissolution. We further demonstrated that Ag(2)SNPs dissolution was primarily attributed to active oxidative substances including hydroxyl radical and H(2)O(2) originating from the hypochlorite oxidation. Additionally, water containing Ag(2)SNPs disinfected with hypochlorite showed stronger interference on the zebra fish (Danio rerio) embryo hatching than Ag(2)SNPs and hypochlorite on their own. This work documented that Ag(2)SNPs could undergo dissolution in surface water through hypochlorite oxidation, posing potential risks to aquatic organisms, and therefore showed new insights into the stability of Ag(2)SNPs in natural environment.","pmid":"28608678","doi":"10.1021/acs.est.7b01738","url":"https://pubmed.ncbi.nlm.nih.gov/28608678/"},{"id":1426,"title":"Oxidation of phosphorothioate DNA modifications leads to lethal genomic instability.","authors":"Kellner, Stefanie; DeMott, Michael S; Cheng, Ching Pin; Russell, Brandon S; Cao, Bo; You, Delin; Dedon, Peter C","year":2017,"date":"2017 Aug","journal":"Nature chemical biology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Genomic modification by sulfur in the form of phosphorothioate (PT) is widespread among prokaryotes, including human pathogens. Apart from its physiological functions, PT sulfur has redox and nucleophilic properties that suggest effects on bacterial fitness in stressful environments. Here we show that PTs are dynamic and labile DNA modifications that cause genomic instability during oxidative stress. In experiments involving isotopic labeling coupled with mass spectrometry, we observed sulfur replacement in PTs at a rate of ∼2% h(-1) in unstressed Escherichia coli and Salmonella enterica. Whereas PT levels were unaffected by exposure to hydrogen peroxide (H(2)O(2)) or hypochlorous acid (HOCl), PT turnover increased to 3.8-10% h(-1) after HOCl treatment and was unchanged by H(2)O(2), consistent with the repair of HOCl-induced sulfur damage. PT-dependent sensitivity to HOCl extended to cytotoxicity and DNA strand breaks, which occurred at HOCl doses that were orders of magnitude lower than the corresponding doses of H(2)O(2). The genotoxicity of HOCl in PT-containing bacteria suggests reduced fitness in competition with HOCl-producing organisms and during infections in humans.","pmid":"28604692","doi":"10.1038/nchembio.2407","url":"https://pubmed.ncbi.nlm.nih.gov/28604692/"},{"id":1427,"title":"A Graphene Quantum Dots-Hypochlorite Hybrid System for the Quantitative Fluorescent Determination of Total Antioxidant Capacity.","authors":"Wang, Min; Chen, Jie; Liu, Chenghao; Qiu, Jianding; Wang, Xiaomeng; Chen, Peng; Xu, Chenjie","year":2017,"date":"2017 Aug","journal":"Small (Weinheim an der Bergstrasse, Germany)","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Antioxidants play a major part in the prevention and impairment of oxidative stress-induced damages and diseases. Evaluating the antioxidants activity/capacity in food and biological fluid is proved to be useful for the diagnosis and treatment of these oxidative stress-induced diseases. Herein, a graphene quantum dots (GQDs)-hypochlorite system to detect the antioxidants including nonenzymatic and enzymatic antioxidants in the biological fluid is proposed. The detection principle is based on the fact that antioxidants can protect the fluorescence of GQDs from hypochlorite-caused quenching by acting as the scavengers of hypochlorite. The GQDs-hypochlorite system allows the accurate quantification of the total antioxidant capacity (TAC) of commercial drinks as well as the extracellular superoxide dismutase (SOD) secretion upon stimulation of cytokines or hyperglycemia. This system shows the excellent analytical recoveries for commercial drinks (>89.9%) and good consistency with ELISA testing for SOD secretion in cell-conditioned medium. These results demonstrate the ability and reliability of the GQD-hypochlorite system for detecting and quantifying TAC in real drinks and complex biological fluids.","pmid":"28597508","doi":"10.1002/smll.201700709","url":"https://pubmed.ncbi.nlm.nih.gov/28597508/"},{"id":1429,"title":"An alternative approach to gynecological wound healing.","authors":"Rzepka, Jakub; Mosoń, Katarzyna; Dębski, Romuald","year":2017,"date":"2017","journal":"Ginekologia polska","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"An 89-year-old woman was reffered to our Clinic with vulvar cancer. She also suffered from obesity [with body mass index (BMI) 35 kg/m2], persistent hypertension, diabetes mellitus type 2 treated with oral medications. In 2015 she underwent a surgery due to endometrial carcinoma. Total abdominal hysterectomy with bilateral salphingoophorectomy, omentectomy and pelvical node dissection was performed (histopathology revealed adenocarcinoma serosum G2; FIGO stage Ib). In January 2016 after vulvar ulceration biopsy plano-epithelial squamous vulvar cancer was diagnosed. She was referred to surgery. She has undergone an operation in October 2016. She was admitted to gynaecological unit at our institution. Physical examination revealed mutilated vulva with excised labia major, labia minor, and narrowing of vaginal orifice. The right side shown tumor 2.5 cm in diameter, with slough area and no deep infiltration and satellital nodule on the left labia majora 1cm in diameter. The cervix, vaginal wall, rectum and anus appeared normal. There were no enlarged lymph nodes at the inguinal area.","pmid":"28509325","doi":"10.5603/GP.a2017.0042","url":"https://pubmed.ncbi.nlm.nih.gov/28509325/"},{"id":1430,"title":"A fluorescent homogeneous assay for myeloperoxidase measurement in biological samples. A positive correlation between myeloperoxidase-generated HOCl level and oxidative status in STZ-diabetic rats.","authors":"Stocker, Pierre; Cassien, Mathieu; Vidal, Nicolas; Thétiot-Laurent, Sophie; Pietri, Sylvia","year":2017,"date":"2017 Aug 1","journal":"Talanta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase (MPO) is a key enzyme derived from leukocytes which is associated with the initiation and progression of many inflammatory diseases. Increased levels of MPO may contribute to cellular dysfunction and tissues injury by producing highly reactive oxidants such as hypochlorous acid (HOCl). Myeloperoxidase-generated HOCl is therefore considered as a relevant biomarker of oxidative stress-related damage and its quantitation is of great importance to the study of disease progression. In this context, the current study describes a rapid, sensitive and homogeneous fluorescence-based method for detecting the MPO chlorination activity in biological samples. This assay utilizes 7-hydroxy-2-oxo-2H-chromene-8-carbaldehyde oxime as a selective probe for HOCl detection, and is adapted to 96-well microplates to allow high-throughput quantitation of active MPO. The ability of the method to monitor HOCl release was further investigated in hyperglycemic streptozotocin-treated diabetic rats. The data proved that the present assay has a reliable performance when quantitating the active MPO in the plasma of diabetic animals, a feature of inflammatory disease found concomitant with an elevation of protein carbonyls levels and lipid peroxidation and which was negatively correlated with the ratio of reduced-to-oxidized glutathione.","pmid":"28501147","doi":"10.1016/j.talanta.2017.03.102","url":"https://pubmed.ncbi.nlm.nih.gov/28501147/"},{"id":1432,"title":"Oxidized 5-aminosalicylic acid activates Nrf2-HO-1 pathway by covalently binding to Keap1: Implication in anti-inflammatory actions of 5-aminosalicylic acid.","authors":"Kang, Sookjin; Kim, Wooseong; Jeong, Seongkeun; Lee, Yonghyun; Nam, Joon; Lee, Sunyoung; Jung, Yunjin","year":2017,"date":"2017 Jul","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Mesalazine (5-aminosalicylic acid, 5-ASA), a currently used drug for anti-inflammatory bowel disease, is easily oxidized by HOCl, a strong oxidant generated in gut inflammation, to produce electrophilic quinones. We investigated whether this chemical feature has an implication in the anti-inflammatory pharmacology of 5-ASA. Human colon carcinoma HCT116 cells were treated with HOCl-reacted 5-ASA. Oxidized 5-ASA activated Nrf2 while 5-ASA itself was not effective. Activation of Nrf2 led to induction of hemeoxygenase (OH)-1, an anti-inflammatory enzyme. Western blot analysis of Keap1, a cytosolic repressor of Nrf2, following precipitation of biotin-labeled proteins in cell lysates treated with biotin-tagged 5-ASA, revealed a much greater amount of Keap1 when biotin-tagged 5-ASA was oxidized with HOCl. Precipitation of Keap1 was attenuated markedly by pretreatment with oxidized 5-ASA or a sulfhydryl donor. In addition, treatment with oxidized 5-ASA in cell lysates reduced the Keap1 amount that coimmunoprecipitated with Nrf2. In parallel, rectal administration of 5-ASA increased the level of HO-1 and nuclear Nrf2 in the inflamed colonic tissues, but not in normal colonic tissues. Moreover, oral gavage of sulfasalazine, a colon-specific prodrug of 5-ASA currently used clinically, activated the Nrf2-HO-1 pathway in the colonic tissues where inflammation was in progress, which was not observed when inflammation subsided. Collectively, our data suggest that Nrf2-HO-1 pathway is involved in the anti-inflammatory pharmacology of 5-ASA, which was likely being exerted exclusively in the inflammatory state.","pmid":"28473247","doi":"10.1016/j.freeradbiomed.2017.04.366","url":"https://pubmed.ncbi.nlm.nih.gov/28473247/"},{"id":1437,"title":"Personal protective equipment solution for UK military medical personnel working in an Ebola virus disease treatment unit in Sierra Leone.","authors":"Reidy, P; Fletcher, T; Shieber, C; Shallcross, J; Towler, H; Ping, M; Kenworthy, L; Silman, N; Aarons, E","year":2017,"date":"2017 May","journal":"The Journal of hospital infection","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"The combination of personal protective equipment (PPE) together with donning and doffing protocols was designed to protect British and Canadian military medical personnel in the Kerry Town Ebola Treatment Unit (ETU) in Sierra Leone. The PPE solution was selected to protect medical staff from infectious risks, notably Ebola virus, and chemical (hypochlorite) exposure. PPE maximized dexterity, enabled personnel to work in hot temperatures for periods of up to 2h, protected mucosal membranes when doffing outer layers, and minimized potential contamination of the doffing area with infectious material by reducing the requirement to spray PPE with hypochlorite. The ETU was equipped to allow medical personnel to provide a higher level of care than witnessed in many existing ETUs. This assured personnel working as part of the international response that they would receive as close to Western treatment standards as possible if they were to contract Ebola virus disease (EVD). PPE also enabled clinical interventions that are not seen routinely in West African EVD treatment regimens, whilst providing a robust protective barrier. Competency in using PPE was developed during a nine-day pre-deployment training programme. This allowed over 60 clinical personnel per deployment to practice skills in PPE in a simulated ETU and in classrooms. Overall, the training provided: (i) an evidence base underpinning the PPE solution chosen; (ii) skills in donning and doffing of PPE; (iii) personnel confidence in the selected PPE; and (iv) quantifiable testing of each individual's capability to don PPE, perform tasks and doff PPE safely.","pmid":"28420487","doi":"10.1016/j.jhin.2017.03.018","url":"https://pubmed.ncbi.nlm.nih.gov/28420487/"},{"id":1443,"title":"Inhibition of Myeloperoxidase- and Neutrophil-Mediated Hypochlorous Acid Formation in Vitro and Endothelial Cell Injury by (-)-Epigallocatechin Gallate.","authors":"Tian, Rong; Ding, Yun; Peng, Yi-Yuan; Lu, Naihao","year":2017,"date":"2017 Apr 19","journal":"Journal of agricultural and food chemistry","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Myeloperoxidase (MPO) plays important roles in various diseases through its unique chlorinating activity to catalyze excess hypochlorous acid (HOCl) formation. Epidemiological studies indicate an inverse correlation between plant polyphenol consumption and the incidence of cardiovascular diseases. Here we showed that (-)-epigallocatechin gallate (EGCG), the main flavonoid present in green tea, dose-dependently inhibited MPO-mediated HOCl formation in vitro (chlorinating activities of MPO: 50.2 ± 5.7% for 20 μM EGCG versus 100 ± 5.6% for control, P < 0.01). UV-vis spectral and docking studies indicated that EGCG bound to the active site (heme) of MPO and resulted in the accumulation of compound II, which was unable to produce HOCl. This flavonoid also effectively inhibited HOCl generation in activated neutrophils (HOCl formation: 65.0 ± 5.6% for 20 μM EGCG versus 100 ± 6.2% for control, P < 0.01) without influencing MPO and Nox2 release and superoxide formation, suggesting that EGCG specifically inhibited MPO but not NADPH oxidase activity in activated neutrophils. Moreover, EGCG inhibited MPO (or neutrophil)-mediated HOCl formation in human umbilical vein endothelial cells (HUVEC) culture and accordingly protected HUVEC from MPO (or neutrophil)-induced injury (P < 0.05, all cases), although it did not induce cytotoxicity to HUVEC (P > 0.05, all cases). Our results indicate that dietary EGCG is an effective and specific inhibitor of MPO activity and may participate in the regulation of immune responses at inflammatory sites.","pmid":"28361543","doi":"10.1021/acs.jafc.7b00631","url":"https://pubmed.ncbi.nlm.nih.gov/28361543/"},{"id":1444,"title":"Optimization for zeolite regeneration and nitrogen removal performance of a hypochlorite-chloride regenerant.","authors":"Zhang, Wei; Zhou, Zhen; An, Ying; Du, Silu; Ruan, Danian; Zhao, Chengyue; Ren, Ning; Tian, Xiaoce","year":2017,"date":"2017 Jul","journal":"Chemosphere","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Simultaneous zeolites regeneration and nitrogen removal were investigated by using a mixed solution of NaClO and NaCl (NaClO-NaCl solution), and effects of the regenerant on ammonium removal performance and textural properties of zeolites were analyzed by long-term adsorption and regeneration operations. Mixed NaClO-NaCl solution removed more NH(4)(+) exchanged on zeolites and converted more of them to nitrogen than using NaClO or NaCl solution alone. Response surface methodological analysis indicated that molar ratio of hypochlorite and nitrogen (ClO(-)/N), NaCl concentration and pH value all had significant effects on zeolites regeneration and NH(4)(+) conversion to nitrogen, and the optimum condition was obtained at ClO(-)/N of 1.75, NaCl concentration of 20 g/L and pH of 10.0. Zeolites regenerated by mixed NaClO-NaCl solution showed higher ammonium adsorption rate and lower capacity than unused zeolites. Zeolites and the regeneration solution were both effective even after 20 cycles of use. Composition and morphological analysis revealed that the main mineral species and surface morphology of zeolites before and after NaClO-NaCl regeneration were unchanged. Textural analysis indicated that NaClO-NaCl regeneration leads to an increased surface area of zeolites, especially the microporosity. The results indicated that NaClO-NaCl regeneration is an attractive method to achieve sustainable removal of nitrogen from wastewater through zeolite.","pmid":"28351015","doi":"10.1016/j.chemosphere.2017.03.091","url":"https://pubmed.ncbi.nlm.nih.gov/28351015/"},{"id":1448,"title":"Topical Approaches to Improve Surgical Outcomes and Wound Healing: A Review of Efficacy and Safety.","authors":"Totoraitis, Kristin; Cohen, Joel L; Friedman, Adam","year":2017,"date":"2017 Mar 1","journal":"Journal of drugs in dermatology : JDD","category":"Food & agriculture","evidence":"Review","relevance":"High","abstract":"<p>Surgical procedures are an important piece of a dermatologist's daily practice. Therefore, the optimization of post-surgical wound healing is an area of utmost importance and interest. Although low risk, one notable barrier to proper wound healing is surgical site infection.</p> <p>In an attempt to mitigate this risk and improve surgical outcomes, multiple topical products continue to be used both pre- and postprocedure. Traditionally, this includes both topical antibiotics and antiseptics. However, these products are not without consequence.</p> <p>The overuse of topical antibiotics as prophylaxis for infection has contributed to increased bacterial resistance, and in fact is no longer recommended by the American Academy of Dermatology in clean post surgical wounds. Topical antiseptics, including chlorhexidine and povidone-iodine, can have a cytotoxic effect on keratinocytes and may actually impede wound healing as a result. In addition, chlorhexidine in particular can produce both otologic and ocular toxic effects when used on the face. Emerging products, such as hypochlorous acid, may be a potential alternative to the more commonly used agents, as it has effective antimicrobial actions and minimal adverse effects. Therefore, the purpose of this review is to highlight several topical products used to optimize post-surgical wound healing and discuss both their efficacy and safety.</p> <p><em>J Drugs Dermatol. 2017;16(3):209-212.</em></p>.","pmid":"28301615","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/28301615/"},{"id":1452,"title":"Reaction of tetracycline with biologically relevant chloramines.","authors":"Benavides, J; Barrias, P; Piro, N; Arenas, A; Orrego, A; Pino, E; Villegas, L; Dorta, E; Aspée, A; López-Alarcón, C","year":2017,"date":"2017 May 5","journal":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Helicobacter pylori (H. pylori) infection triggers inflammatory processes with the consequent production of hypochlorous acid (HOCl), monochloramine (NH(2)Cl), and protein-derived chloramines. As the therapy for eradicating H. pylori is partially based on the use of tetracycline, we studied the kinetic of its consumption elicited by HOCl, NH(2)Cl, N-chloro-n-butylamine (NHCl-But, used as a lysine-derived chloramine model), and lysozyme-derived chloramines. In the micromolar concentration range, tetracycline reacted rapidly with HOCl, generating in the first few seconds intermediates of short half-life. In contrast, a slow tetracycline consumption was observed in the presence of high NH(2)Cl and NHCl-But concentrations (millimolar range). Similar chlorinated products of tetracycline were identified by mass spectrometry, in the presence of HOCl and NH(2)Cl. These results evidenced that tautomers of tetracycline are pivotal intermediates in all reactions. In spite of the low reactivity of chloramines towards tetracycline, it is evident that, in the concentration range where they are produced in a H. pylori infection (millimolar range), the reactions lead to oxidation and/or chlorination of tetracycline. This kind of reactions, which were also observed triggered by lysozyme-derived chloramines, could limit the efficiency of the tetracycline-based therapy.","pmid":"28187315","doi":"10.1016/j.saa.2017.02.001","url":"https://pubmed.ncbi.nlm.nih.gov/28187315/"},{"id":1457,"title":"Myeloperoxidase targets oxidative host attacks to Salmonella and prevents collateral tissue damage.","authors":"Schürmann, Nura; Forrer, Pascal; Casse, Olivier; Li, Jiagui; Felmy, Boas; Burgener, Anne-Valérie; Ehrenfeuchter, Nikolaus; Hardt, Wolf-Dietrich; Recher, Mike; Hess, Christoph; Tschan-Plessl, Astrid; Khanna, Nina; Bumann, Dirk","year":2017,"date":"2017 Jan 23","journal":"Nature microbiology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Host control of infections crucially depends on the capability to kill pathogens with reactive oxygen species (ROS). However, these toxic molecules can also readily damage host components and cause severe immunopathology. Here, we show that neutrophils use their most abundant granule protein, myeloperoxidase, to target ROS specifically to pathogens while minimizing collateral tissue damage. A computational model predicted that myeloperoxidase efficiently scavenges diffusible H(2)O(2) at the surface of phagosomal Salmonella and converts it into highly reactive HOCl (bleach), which rapidly damages biomolecules within a radius of less than 0.1 μm. Myeloperoxidase-deficient neutrophils were predicted to accumulate large quantities of H(2)O(2) that still effectively kill Salmonella, but most H(2)O(2) would leak from the phagosome. Salmonella stimulation of neutrophils from normal and myeloperoxidase-deficient human donors experimentally confirmed an inverse relationship between myeloperoxidase activity and extracellular H(2)O(2) release. Myeloperoxidase-deficient mice infected with Salmonella had elevated hydrogen peroxide tissue levels and exacerbated oxidative damage of host lipids and DNA, despite almost normal Salmonella control. These data show that myeloperoxidase has a major function in mitigating collateral tissue damage during antimicrobial oxidative bursts, by converting diffusible long-lived H(2)O(2) into highly reactive, microbicidal and locally confined HOCl at pathogen surfaces.","pmid":"28112722","doi":"10.1038/nmicrobiol.2016.268","url":"https://pubmed.ncbi.nlm.nih.gov/28112722/"},{"id":1459,"title":"Fruiting Bodies of Antrodia cinnamomea and Its Active Triterpenoid, Antcin K, Ameliorates N-Nitrosodiethylamine-Induced Hepatic Inflammation, Fibrosis and Carcinogenesis in Rats.","authors":"Tien, An-Jan; Chien, Chen-Yen; Chen, Yueh-Hsi; Lin, Lung-Chin; Chien, Chiang-Ting","year":2017,"date":"2017","journal":"The American journal of Chinese medicine","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Antrodia cinnamomea (A. cinnamomea), a popular medicinal mushroom in Taiwan, is widely used to prevent or treat liver diseases. Systematic studies on the anti-inflammatory effect of A. cinnamomea and its molecular mechanisms have not yet been fully investigated. HPLC fingerprint analysis identified seven ergostane-type triterpenoids from A. cinnamomea water extract (ACW), including high amounts of Antcin K (AC), Antcin C, Antcin H, Dehydrosulphurenic acid, Antcin B, Antcin A and Dehydroeburicoic acid. Here, we explored the effects and mechanisms of ACW and the highest content AC on N-nitrosodiethylamine (DEN) induced liver inflammation, fibrosis and carcinogenesis in rats. In the in vitro study, we measured how ACW and AC dose-dependently scavenged O[Formula: see text], H(2)O(2) and HOCl by a chemiluminescence analyzer. In the in vivo experiment, oral intake ACW and AC significantly inhibited DEN-enhanced hepatocellular inflammation, fibrosis and carcinoma by pathologic observation, the elevated bile and liver reactive oxygen species (ROS) amounts, plasma [Formula: see text]-glutamyl transpeptidase, and oxidative stress including 3-nitrotyrosine, 4-hydroxynonenal and Kuppfer cell infiltration (ED-1 stains) in the inflammatory livers. DEN enhanced nuclear factor-[Formula: see text]B (NF-[Formula: see text]B) translocation, whereas ACW and AC suppressed DEN-enhanced NF-[Formula: see text]B translocation through the inhibition of its upstream signaling of p85/phosphoinositide-3-kinase, mitogen activated protein kinase and CYP2E1 expression. In conclusion, DEN can induce hepatocellular inflammation, fibrosis and carcinoma by increasing NF-[Formula: see text]B translocation to the nucleus, and oxidative injury. ACW and its active component, Antcin K, counteract DEN-induced hepatic injury and inflammation by the protective and therapeutic mechanisms of a direct scavenging ROS activity and an upregulation of anti-oxidant defense mechanisms.","pmid":"28081627","doi":"10.1142/S0192415X17500124","url":"https://pubmed.ncbi.nlm.nih.gov/28081627/"},{"id":1460,"title":"Myeloperoxidase-mediated protein lysine oxidation generates 2-aminoadipic acid and lysine nitrile in vivo.","authors":"Lin, Hongqiao; Levison, Bruce S; Buffa, Jennifer A; Huang, Ying; Fu, Xiaoming; Wang, Zeneng; Gogonea, Valentin; DiDonato, Joseph A; Hazen, Stanley L","year":2017,"date":"2017 Mar","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Recent studies reveal 2-aminoadipic acid (2-AAA) is both elevated in subjects at risk for diabetes and mechanistically linked to glucose homeostasis. Prior studies also suggest enrichment of protein-bound 2-AAA as an oxidative post-translational modification of lysyl residues in tissues associated with degenerative diseases of aging. While in vitro studies suggest redox active transition metals or myeloperoxidase (MPO) generated hypochlorous acid (HOCl) may produce protein-bound 2-AAA, the mechanism(s) responsible for generation of 2-AAA during inflammatory diseases are unknown. In initial studies we observed that traditional acid- or base-catalyzed protein hydrolysis methods previously employed to measure tissue 2-AAA can artificially generate protein-bound 2-AAA from an alternative potential lysine oxidative product, lysine nitrile (LysCN). Using a validated protease-based digestion method coupled with stable isotope dilution LC/MS/MS, we now report protein bound 2-AAA and LysCN are both formed by hypochlorous acid (HOCl) and the MPO/H(2)O(2)/Cl(-) system of leukocytes. At low molar ratio of oxidant to target protein N(ε)-lysine moiety, 2-AAA is formed via an initial N(ε)-monochloramine intermediate, which ultimately produces the more stable 2-AAA end-product via sequential generation of transient imine and semialdehyde intermediates. At higher oxidant to target protein N(ε)-lysine amine ratios, protein-bound LysCN is formed via initial generation of a lysine N(ε)-dichloramine intermediate. In studies employing MPO knockout mice and an acute inflammation model, we show that both free and protein-bound 2-AAA, and in lower yield, protein-bound LysCN, are formed by MPO in vivo during inflammation. Finally, both 2-AAA and to lesser extent LysCN are shown to be enriched in human aortic atherosclerotic plaque, a tissue known to harbor multiple MPO-catalyzed protein oxidation products. Collectively, these results show that MPO-mediated oxidation of protein lysyl residues serves as a mechanism for producing 2-AAA and LysCN in vivo. These studies further support involvement of MPO-catalyzed oxidative processes in both the development of atherosclerosis and diabetes risk.","pmid":"28069522","doi":"10.1016/j.freeradbiomed.2017.01.006","url":"https://pubmed.ncbi.nlm.nih.gov/28069522/"},{"id":1463,"title":"Transformation of aminopyrine in the presence of free available chlorine: Kinetics, products, and reaction pathways.","authors":"Cai, Mei-Quan; Feng, Li; Zhang, Li-Qiu","year":2017,"date":"2017 Mar","journal":"Chemosphere","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Aminopyrine (AMP) has been frequently detected in the aquatic environment. In this study, the transformation mechanism of AMP by free available chlorine (FAC) oxidation was investigated. The results showed that FAC reacted with AMP rapidly, and a 74% elimination was achieved for 1.30 μM AMP after 2 min at 14.08 μM FAC dose. AMP chlorination was strongly pH-dependent, and its reaction included second- and third-order kinetic processes. Three active FAC species, including chlorine monoxide (Cl(2)O), molecular chlorine (Cl(2)), and hypochlorous acid (HOCl), were observed to contribute to AMP degradation. The intrinsic rate constants of each FAC species with neutral (AMP(0)) and cation (AMP(+)) species were obtained by kinetic fitting. Cl(2)O exhibited the highest reactivity with AMP(0) (k(AMP0, Cl2O) = (4.33 ± 1.4) × 10(9) M(-1)s(-1)). In addition, Cl(2) showed high reactivity (10(6)-10(7) M(-1)s(-1)) in the presence of chloride, compared with HOCl (k(AMP+, HOCl) = (5.73 ± 0.23) × 10(2) M(-1)s(-1), k(AMP0, HOCl) = (9.68 ± 0.96) × 10(2) M(-1)s(-1)). At pH 6.15 and 14.08 μM FAC dose without chloride addition, the contribution of Cl(2)O reached to the maximum (33.3%), but in the whole pH range, HOCl was the main contributor (>66.6%) for AMP degradation. The significance of Cl(2) was noticeable in water containing chloride. Moreover, 11 transformation products were identified, and the main transformation pathways included pyrazole ring breakage, hydroxylation, dehydrogenation, and halogenation.","pmid":"28056449","doi":"10.1016/j.chemosphere.2016.12.033","url":"https://pubmed.ncbi.nlm.nih.gov/28056449/"},{"id":1465,"title":"Protein S-Bacillithiolation Functions in Thiol Protection and Redox Regulation of the Glyceraldehyde-3-Phosphate Dehydrogenase Gap in Staphylococcus aureus Under Hypochlorite Stress.","authors":"Imber, Marcel; Huyen, Nguyen Thi Thu; Pietrzyk-Brzezinska, Agnieszka J; Loi, Vu Van; Hillion, Melanie; Bernhardt, Jörg; Thärichen, Lena; Kolšek, Katra; Saleh, Malek; Hamilton, Chris J; Adrian, Lorenz; Gräter, Frauke; Wahl, Markus C; Antelmann, Haike","year":2018,"date":"2018 Feb 20","journal":"Antioxidants & redox signaling","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"AIMS: Bacillithiol (BSH) is the major low-molecular-weight thiol of the human pathogen Staphylococcus aureus. In this study, we used OxICAT and Voronoi redox treemaps to quantify hypochlorite-sensitive protein thiols in S. aureus USA300 and analyzed the role of BSH in protein S-bacillithiolation. RESULTS: The OxICAT analyses enabled the quantification of 228 Cys residues in the redox proteome of S. aureus USA300. Hypochlorite stress resulted in >10% increased oxidation of 58 Cys residues (25.4%) in the thiol redox proteome. Among the highly oxidized sodium hypochlorite (NaOCl)-sensitive proteins are five S-bacillithiolated proteins (Gap, AldA, GuaB, RpmJ, and PpaC). The glyceraldehyde-3-phosphate (G3P) dehydrogenase Gap represents the most abundant S-bacillithiolated protein contributing 4% to the total Cys proteome. The active site Cys151 of Gap was very sensitive to overoxidation and irreversible inactivation by hydrogen peroxide (H(2)O(2)) or NaOCl in vitro. Treatment with H(2)O(2) or NaOCl in the presence of BSH resulted in reversible Gap inactivation due to S-bacillithiolation, which could be regenerated by the bacilliredoxin Brx (SAUSA300_1321) in vitro. Molecular docking was used to model the S-bacillithiolated Gap active site, suggesting that formation of the BSH mixed disulfide does not require major structural changes. Conclusion and Innovation: Using OxICAT analyses, we identified 58 novel NaOCl-sensitive proteins in the pathogen S. aureus that could play protective roles against the host immune defense and include the glycolytic Gap as major target for S-bacillithiolation. S-bacillithiolation of Gap did not require structural changes, but efficiently functions in redox regulation and protection of the active site against irreversible overoxidation in S. aureus. Antioxid. Redox Signal. 28, 410-430.","pmid":"27967218","doi":"10.1089/ars.2016.6897","url":"https://pubmed.ncbi.nlm.nih.gov/27967218/"},{"id":1468,"title":"Potential roles of myeloperoxidase and hypochlorous acid in metabolism and toxicity of alkene hydrocarbons and drug molecules containing olefinic moieties.","authors":"Zhang, Xin-Yu; Elfarra, Adnan A","year":2017,"date":"2017 May","journal":"Expert opinion on drug metabolism & toxicology","category":"Food & agriculture","evidence":"Review","relevance":"High","abstract":"Adverse drug reactions (ADRs) pose a significant health problem and are generally attributed to reactive metabolites. Olefinic moieties in drugs can undergo cytochrome P450-mediated bioactivation to produce reactive metabolites but myeloperoxidase (MPO)-mediated bioactivation of these moieties has not been reported. Thus, small molecules of alkene hydrocarbons are used as model compounds to characterize the MPO-mediated metabolism. Areas covered: The authors focus on MPO-mediated metabolism of alkene hydrocarbons to form chlorohydrins and the potential role of chlorohydrins in alkene toxicity and carcinogenicity. A case study is presented, in which a carcinogenic alkene, 1,3-butadiene, is demonstrated to form 1-chloro-2-hydroxy-3-butene (CHB) through the MPO-mediated pathway. Further bioactivation of CHB yields a cross-linking metabolite, 1-chloro-3-buten-2-one (CBO), which is highly reactive toward glutathione, proteins, nucleosides, and DNA. Toxicity and mutagenicity of CHB and CBO are also presented. Expert opinion: Alkene hydrocarbons readily undergo MPO-mediated bioactivation to form chlorohydrins, which can further be biotransformed into proteins/DNA-modifying reactive metabolites. Therefore, chlorohydrin formation may play an important role in alkene toxicity and carcinogenicity. Olefinic moieties in drugs are expected to undergo similar bioactivation, which may contribute to ADRs. Studies to investigate the roles of MPO and chlorohydrin formation in ADRs are thus warranted.","pmid":"27936967","doi":"10.1080/17425255.2017.1271413","url":"https://pubmed.ncbi.nlm.nih.gov/27936967/"},{"id":1471,"title":"Low-concentration hypochlorous acid nasal irrigation for chronic sinonasal symptoms: a prospective randomized placebo-controlled study.","authors":"Yu, Myeong Sang; Kim, Bo-Hyung; Kang, Sung-Ho; Lim, Dae Jun","year":2017,"date":"2017 Mar","journal":"European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"Low-concentration hypochlorous acid (HOCl) is an endogenous antibacterial and antiviral agent. The purpose of this study was to evaluate the effectiveness of HOCl irrigation in patients with chronic rhinosinusitis (CRS) refractory to medical therapy. Forty-three adult patients (mean age 45.5 years) were enrolled in this study. They were randomly chosen to receive nasal irrigation with either low-concentration HOCl generated by a Salicid device (n = 21), or a placebo (saline; n = 22) for 8 weeks. The outcome measures were scores on the 20-Item SinoNasal Outcome Test (SNOT-20), rhinosinusitis disability index (RSDI), nasal endoscopic score, and bacterial cultures. The SNOT-20 scores were significantly lower in the HOCl group than in the placebo group after 2 weeks of treatment (p < 0.05) and remained lower after 4 weeks of treatment. With respect to the RSDI scores, there was a significant improvement in the HOCl group at 1 week after treatment and in both groups at 2 weeks after treatment (p < 0.05). There were no significant differences in the endoscopic scores between the two groups after the treatment. The bacterial culture rates were lower in the HOCl group than in the placebo group after 4 weeks of treatment, but this was not significant (p > 0.05). Our results showed that low-concentration HOCl irrigation resulted in a greater improvement in CRS symptoms as compared to saline irrigation.","pmid":"27853946","doi":"10.1007/s00405-016-4387-5","url":"https://pubmed.ncbi.nlm.nih.gov/27853946/"},{"id":1472,"title":"A contrast study of Dermacyn on enterocoely irrigate to control intraoperative infection.","authors":"Liu, Jun; Fan, Peishi; Chu, Jun; Yang, Jian; Yang, Xiaohu; Zhang, Lu; Guo, Chunliang","year":2017,"date":"2017 Apr","journal":"Minerva chirurgica","category":"Water, sanitation & biosecurity","evidence":"Randomized controlled trial","relevance":"High","abstract":"BACKGROUND: To evaluate antimicrobial properties of Dermacyn in abdominal infections, and to develop a new method for peritoneal lavage without using antibiotics. METHODS: One hundred and ten patients suffering from intestinal perforation (abdominal closed injury), who had been treated with opened surgical repair or partial intestinal resection, were enrolled in this study. In the study group, Dermacyn was used for peritoneal lavage. During the same period, 102 patients with intestinal perforation of abdominal closed injury and opened repair or partial intestinal resection were enrolled as a control group. For the control group, metronidazole physiological saline was used for peritoneal lavage. Patients from both groups had a postoperative indwelling peritoneal drainage tube. Five objective indicators were studied and compared at 24, 48, and 72 hours: volume of drainage, drainage fluid culture, blood routine test, C-reactive protein, calcitonin and antibiotics dose. RESULTS: There were no significant differences between the drainage volumes in two groups three days after the operation. There were significant differences in the nature of the drainage fluid, bacterial culture results, blood routine, C-reactive protein and procalcitonin between the two groups. In the experimental group, after the Dermacyn flushing, the average volume of peritoneal drainage fluid was reduced (from 30 to 5 mL) from 24 to 72 hours postoperatively. CONCLUSIONS: The use of Dermacyn as an antibiotic agent for intraoperative peritoneal lavage was effective in reducing the risk of infection, due to its broad-spectrum bactericidal effect. Dermacyn could be used safely to perform peritoneal flushing to clean the operation site.","pmid":"27841850","doi":"10.23736/S0026-4733.16.07192-3","url":"https://pubmed.ncbi.nlm.nih.gov/27841850/"},{"id":1474,"title":"Kinetic studies on the reaction of cob(II)alamin with hypochlorous acid: Evidence for one electron oxidation of the metal center and corrin ring destruction.","authors":"Dassanayake, Rohan S; Farhath, Mohamed M; Shelley, Jacob T; Basu, Soumitra; Brasch, Nicola E","year":2016,"date":"2016 Oct","journal":"Journal of inorganic biochemistry","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Kinetic and mechanistic studies on the reaction of a major intracellular vitamin B(12) form, cob(II)alamin (Cbl(II)), with hypochlorous acid/hypochlorite (HOCl/OCl(-)) have been carried out. Cbl(II) (Co(II)) is rapidly oxidized by HOCl to predominately aquacobalamin/hydroxycobalamin (Cbl(III), Co(III)) with a second-order rate constant of 2.4×10(7)M(-1)s(-1) (25.0°C). The stoichiometry of the reaction is 1:1. UHPLC/HRMS analysis of the product mixture of the reaction of Cbl(II) with 0.9mol equiv. HOCl provides support for HOCl being initially reduced to Cl and subsequent H atom abstraction from the corrin macrocycle occurring, resulting in small amounts of corrinoid species with two or four H atoms fewer than the parent cobalamin. Upon the addition of excess (H)OCl further slower reactions are observed. Finally, SDS-PAGE experiments show that HOCl-induced damage to bovine serum albumin does not occur in the presence of Cbl(II), providing support for Cbl(II) being an efficient HOCl trapping agent.","pmid":"27567143","doi":"10.1016/j.jinorgbio.2016.07.009","url":"https://pubmed.ncbi.nlm.nih.gov/27567143/"},{"id":1475,"title":"A quantum chemical study of HOCl-induced transformations of carbamazepine.","authors":"Tandarić, Tana; Vrček, Valerije; Šakić, Davor","year":2016,"date":"2016 Nov 22","journal":"Organic & biomolecular chemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The antiepileptic drug carbamazepine (CBZ) is one of the most persistent pharmaceuticals in the environment. Its chemical fate is influenced by the type of wastewater treatment. This study sets out to determine the degradation mechanism and products in the reaction between CBZ and hypochlorous acid (HOCl), which is the main chlorinating species in water. In the search for the most feasible pathways of HOCl-induced transformations of CBZ, a quantum chemical approach was employed. Chlorination and epoxidation of CBZ are two initial, competitive processes that result in two key intermediates: N-chloramide and 10,11-epoxide. The calculated free energy barriers (ΔG) for these reactions are 105.7 and 95.7 kJ mol(-1) resp., which is in agreement with the experimental energy barrier of 98.2 kJ mol(-1). All transformation products detected in chlorination experiments were located by computational models, and the reaction mechanism underlying their formation was described in detail. Different computational methods (density functional and ab initio theory) were applied, and the double hybrid B2-PLYPD functional was found to be superior in terms of efficiency and accuracy. Of special interest are oxoiminostilbene and formylacridine, which are the final products in the degradation cascade. Their exceptional thermodynamic stability, as predicted by quantum chemical methods, suggests that these structures should be considered as recalcitrants in chlorinated waters. Fruitful interplay between computational models and experimental data proves that the quantum chemical approach can be used as a predictive tool in environmental degradation studies.","pmid":"27808324","doi":"10.1039/c6ob02166b","url":"https://pubmed.ncbi.nlm.nih.gov/27808324/"},{"id":1476,"title":"Staphylococcus aureus SaeR/S-regulated factors reduce human neutrophil reactive oxygen species production.","authors":"Guerra, Fermin E; Addison, Conrad B; de Jong, Nienke W M; Azzolino, Joseph; Pallister, Kyler B; van Strijp, Jos A G; Voyich, Jovanka M","year":2016,"date":"2016 Nov","journal":"Journal of leukocyte biology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Neutrophils are the first line of defense after a pathogen has breached the epithelial barriers, and unimpaired neutrophil functions are essential to clear infections. Staphylococcus aureus is a prevalent human pathogen that is able to withstand neutrophil killing, yet the mechanisms used by S. aureus to inhibit neutrophil clearance remain incompletely defined. The production of reactive oxygen species (ROS) is a vital neutrophil antimicrobial mechanism. Herein, we test the hypothesis that S. aureus uses the SaeR/S two-component gene regulatory system to produce virulence factors that reduce neutrophil ROS production. With the use of ROS probes, the temporal and overall production of neutrophil ROS was assessed during exposure to the clinically relevant S. aureus USA300 (strain LAC) and its isogenic mutant LACΔsaeR/S Our results demonstrated that SaeR/S-regulated factors do not inhibit neutrophil superoxide (O(2)(-)) production. However, subsequent neutrophil ROS production was significantly reduced during exposure to LAC compared with LACΔsaeR/S In addition, neutrophil H(2)O(2) production was reduced significantly by SaeR/S-regulated factors by a mechanism independent of catalase. Consequently, the reduction in neutrophil H(2)O(2) resulted in decreased production of the highly antimicrobial agent hypochlorous acid/hypochlorite anion (HOCl/(-)OCl). These findings suggest a new evasion strategy used by S. aureus to diminish a vital neutrophil antimicrobial mechanism.","pmid":"27334228","doi":"10.1189/jlb.4VMAB0316-100RR","url":"https://pubmed.ncbi.nlm.nih.gov/27334228/"},{"id":1481,"title":"A fast-responsive fluorescent probe based on BODIPY dye for sensitive detection of hypochlorite and its application in real water samples.","authors":"Wang, Yun; Xia, Jinchen; Han, Juan; Bao, Xu; Li, Yuanyuan; Tang, Xu; Ni, Liang; Wang, Lei; Gao, Mengmeng","year":2016,"date":"2016 Dec 1","journal":"Talanta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorite serves as a powerful antimicrobial agent in human immune system, the detection of which is of great significance. Herein a novel fluorescent probe based on BODIPY dye and diaminomaleonitrile has been synthesized and characterized to sense hypochlorite. The fluorescence of the system is dramatically enhanced by ClO(-) due to the removal of C=N isomerization effect in physiological pH condition. The complete reaction only needs a few seconds, which enables the probe to facilitate real-time detection. This probe also has satisfactory selectivity for ClO(-) even in the presence of other interferential ions and shows high sensitivity with a detection limit of 19.8nM. Furthermore, Probe 1 has been successfully applied to detect ClO(-) in real water samples.","pmid":"27769492","doi":"10.1016/j.talanta.2016.09.025","url":"https://pubmed.ncbi.nlm.nih.gov/27769492/"},{"id":1485,"title":"Antiseptics and Antibiotics for Surgical Wounds Healing by Secondary Intention: Summary of a Cochrane Review.","authors":"Norman, Gill; Dumville, Jo C; Crosbie, Emma J","year":2016,"date":"2016 Nov 1","journal":"JAMA dermatology","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"CLINICAL QUESTION: Do antiseptics and antibiotics benefit surgical wounds healing by secondary intention (SWHSI)? BOTTOM LINE: No high-quality randomized clinical trials have addressed this question. Current evidence is limited and insufficient; it is uncertain whether treating SWHSI with antiseptics or antibiotics is beneficial.","pmid":"27681006","doi":"10.1001/jamadermatol.2016.3131","url":"https://pubmed.ncbi.nlm.nih.gov/27681006/"},{"id":1486,"title":"Involvement of vascular peroxidase 1 in angiotensin II-induced hypertrophy of H9c2 cells.","authors":"Yang, Wei; Liu, Zhaoya; Xu, Qian; Peng, Haiyang; Chen, Luyao; Huang, Xiao; Yang, Tianlun; Yu, Zaixin; Cheng, Guangjie; Zhang, Guogang; Shi, Ruizheng","year":2017,"date":"2017 Aug","journal":"Journal of the American Society of Hypertension : JASH","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Oxidative stress has been implicated in cardiac hypertrophy and heart failure. Vascular peroxidase 1 (VPO1), a peroxidase in the cardiovascular system, uses the hydrogen peroxide (H(2)O(2)) derived from co-expressed NADPH oxidases (NOX) to produce hypochlorous acid (HOCl) and catalyze peroxidative reactions. Our previous studies showed that VPO1 contributes to the vascular smooth muscle cell proliferation and endothelial dysfunction in spontaneous hypertensive rats (SHRs); however, the role of VPO1 in cardiomyocytes hypertrophy is still uninvestigated. The present study was therefore undertaken to examine the role of VPO1 in the angiotensin II-induced cardiac hypertrophy, and the underlying mechanism by which VPO1 regulates the redox signaling. As compared to WKY rats, the SHRs exhibited increased myocyte cross sectional area, enhanced Nox2 and VPO1 expression level in cardiac tissue, and an increased Ang II level in plasma. In cultured H9c2 cell line, Ang II increased the hypertrophy-related gene (BNP/ANF) expression and the cellular surface area, which was attenuated by knocking down of VPO1 via VPO1 siRNA or pharmacological inhibition of NOX/VPO1 pathway. Moreover, the enhanced hypochlorous acid (HOCl) production and phosphorylation of ERK1/2 was suppressed by VPO1 knockdown. Furthermore, the protective role of VPO1 siRNA transfection on H9c2 cardiomyocytes hypertrophy was abrogated on the HOCl stimulation, and the phosphorylated ERK1/2 expression level was found also upregulated after HOCl stimulation. In conclusion, these results suggest that the Nox2/VPO1/HOCl/ERK1/2 redox signaling pathway was implicated in the pathogenesis of Ang II-induced cardiac hypertrophy.","pmid":"27651140","doi":"10.1016/j.jash.2016.08.002","url":"https://pubmed.ncbi.nlm.nih.gov/27651140/"},{"id":1487,"title":"Sensitive detection and estimation of cell-derived peroxynitrite fluxes using fluorescein-boronate.","authors":"Rios, Natalia; Piacenza, Lucía; Trujillo, Madia; Martínez, Alejandra; Demicheli, Verónica; Prolo, Carolina; Álvarez, María Noel; López, Gloria V; Radi, Rafael","year":2016,"date":"2016 Dec","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The specific and sensitive detection of peroxynitrite (ONOO(-)/ONOOH) in biological systems is a great challenge due to its high reactivity towards several biomolecules. Herein, we validated the advantages of using fluorescein-boronate (Fl-B) as a highly sensitive fluorescent probe for the direct detection of peroxynitrite under biologically-relevant conditions in two different cell models. The synthesis of Fl-B was achieved by a very simply two-step conversion synthetic route with high purity (>99%) and overall yield (∼42%). Reactivity analysis of Fl-B with relevant biological oxidants including hydrogen peroxide (H(2)O(2)), hypochlorous acid (HOCl) and peroxynitrite were performed. The rate constant for the reaction of peroxynitrite with Fl-B was 1.7×10(6)M(-1)s(-1), a million times faster than the rate constant measured for H(2)O(2) (k=1.7M(-1)s(-1)) and 2,700 faster than HOCl (6.2×10(2)M(-1)s(-1)) at 37°C and pH 7.4. The reaction of Fl-B with peroxynitrite was significant even in the presence of physiological concentrations of CO(2), a well-known peroxynitrite reactant. Experimental and simulated kinetic analyses confirm that the main oxidation process of Fl-B takes place with peroxynitrite itself via a direct bimolecular reaction and not with peroxynitrite-derived radicals. Fl-B was successfully applied for the detection of endogenously-generated peroxynitrite by endothelial cells and in macrophage-phagocyted parasites. Moreover, the generated data allowed estimating the actual intracellular flux of peroxynitrite. For instance, ionomycin-stimulated endothelial cells generated peroxynitrite at a rate of ∼ 0.1μMs(-1), while immunostimulated macrophages do so in the order of ∼1μMs(-1) inside T. cruzi-infected phagosomes. Fl-B revealed not to be toxic in concentrations up to 1mM for 24h. Cellular peroxynitrite detection was achieved by conventional laboratory fluorescence-based methods including flow cytometry and epi-fluorescence microscopy. Fl-B was shown to be more sensitive than the coumarin boronate due to a higher molar absorption coefficient and quantum yield. Overall, our results show that Fl-B is a kinetically selective and highly sensitive probe for the direct detection of cell-derived peroxynitrite.","pmid":"27641237","doi":"10.1016/j.freeradbiomed.2016.08.033","url":"https://pubmed.ncbi.nlm.nih.gov/27641237/"},{"id":1491,"title":"Effects of air polishing and an amino acid buffered hypochlorite solution to dentin surfaces and periodontal ligament cell survival, attachment, and spreading.","authors":"Schmidlin, Patrick R; Fujioka-Kobayashi, Masako; Mueller, Heinz-Dieter; Sculean, Anton; Lussi, Adrian; Miron, Richard J","year":2017,"date":"2017 Jun","journal":"Clinical oral investigations","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVES: The aim of this study is to examine morphological changes of dentin surfaces following air polishing or amino acid buffered hypochlorite solution application and to assess their influence on periodontal ligament (PDL) cell survival, attachment, and spreading to dentin discs in vitro. MATERIALS AND METHODS: Bovine dentin discs were treated with either (i) Classic, (ii) Plus, or (iii) Perio powder (EMS). Furthermore, Perisolv® a hypochlorite solution buffered with various amino acids was investigated. Untreated dentin discs served as controls. Morphological changes to dentin discs were assessed using scanning electron microscopy (SEM). Human PDL cells were seeded onto the respectively treated discs, and samples were then investigated for PDL cell survival, attachment, and spreading using a live/dead assay, adhesion assay, and SEM imaging, respectively. RESULTS: Both control and Perisolv®-rinsed dentin discs demonstrated smooth surfaces at low and high magnifications. The Classic powders demonstrated the thickest coating followed by the Powder Plus. The Perio powder demonstrated marked alterations of dentin discs by revealing the potential to open dentinal tubules even before rinsing. Seeding of PDL cells demonstrated an almost 100 % survival rate on all samples demonstrating very high biocompatibility for all materials. Significantly higher PDL cell numbers were observed on samples treated with the Perio powder and the Perisolv® solution (approximately 40 % more cells; p < 0.05). SEM imaging revealed the potential for PDL cells to attach and spread on all surfaces. CONCLUSION: The results from the present study demonstrate that cell survival and spreading of PDL cells on root surfaces is possible following either air polishing or application with Perisolv®. Future in vitro and animal testing is necessary to further characterize the beneficial effects of either system in a clinical setting. CLINICAL RELEVANCE: The use of air polishing or application with Perisolv amino acid buffered hypochlorite solution was effective in treating root surfaces and allowed for near 100 % PDL cell survival, attachment, and spreading onto all root surfaces.","pmid":"27596604","doi":"10.1007/s00784-016-1950-9","url":"https://pubmed.ncbi.nlm.nih.gov/27596604/"},{"id":1493,"title":"Kinetics and mechanisms of formation of earthy and musty odor compounds: Chloroanisoles during water chlorination.","authors":"Zhang, Kejia; Zhou, Xinyan; Zhang, Tuqiao; Mao, Minmin; Li, Lei; Liao, Wenchao","year":2016,"date":"2016 Nov","journal":"Chemosphere","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Chloroanisoles are often reported as off-flavor compounds which produce an earthy and musty flavors and odors in drinking water. To improve understanding and ultimately minimize the formation of 2,4-dichloroanisole (2,4-DCA), 2,6-dichloroanisole (2,6-DCA) and 2,4,6-trichloroanisole (2,4,6-TCA), which have low odor threshold concentrations (OTC: 0.03-4 ng L(-1)), a kinetic database for the chlorination of anisole was established by kinetic measurements. The results showed that HOCl reacted with anisole in acidic solution, with the hydrogen ion as an important catalyst. Quantification of product distribution of the produced chloroanisoles demonstrated that a chlorine attack in the para-position was favored over the ortho-position. A kinetic model was formulated, which permitted investigation of the relative importance of the chlorine dose and other water quality parameters including the concentrations of anisole and several metal ions, as well as temperature, on the product distribution of chloroanisoles. In general, high chlorine doses led to low concentrations of intermediates. The presence of ions such as Fe(3+) and Al(3+) facilitated the formation of chloroanisoles, but Zn(2+) and Mn(2+) did not. The kinetic model can be applied to optimize water chlorination and minimize earthy and musty odors.","pmid":"27561731","doi":"10.1016/j.chemosphere.2016.08.051","url":"https://pubmed.ncbi.nlm.nih.gov/27561731/"},{"id":1495,"title":"Elimination of biofilm and microbial contamination reservoirs in hospital washbasin U-bends by automated cleaning and disinfection with electrochemically activated solutions.","authors":"Swan, J S; Deasy, E C; Boyle, M A; Russell, R J; O'Donnell, M J; Coleman, D C","year":2016,"date":"2016 Oct","journal":"The Journal of hospital infection","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"BACKGROUND: Washbasin U-bends are reservoirs of microbial contamination in healthcare environments. U-Bends are constantly full of water and harbour microbial biofilm. AIM: To develop an effective automated cleaning and disinfection system for U-bends using two solutions generated by electrochemical activation of brine including the disinfectant anolyte (predominantly hypochlorous acid) and catholyte (predominantly sodium hydroxide) with detergent properties. METHODS: Initially three washbasin U-bends were manually filled with catholyte followed by anolyte for 5min each once weekly for five weeks. A programmable system was then developed with one washbasin that automated this process. This U-bend had three cycles of 5min catholyte followed by 5min anolyte treatment per week for three months. Quantitative bacterial counts from treated and control U-bends were determined on blood agar (CBA), R2A, PAS, and PA agars following automated treatment and on CBA and R2A following manual treatment. FINDINGS: The average bacterial density from untreated U-bends throughout the study was >1×10(5) cfu/swab on all media with Pseudomonas aeruginosa accounting for ∼50% of counts. Manual U-bend electrochemically activated (ECA) solution treatment reduced counts significantly (<100cfu/swab) (P<0.01 for CBA; P<0.005 for R2A). Similarly, counts from the automated ECA-treatment U-bend were significantly reduced with average counts for 35 cycles on CBA, R2A, PAS, and PA of 2.1±4.5 (P<0.0001), 13.1±30.1 (P<0.05), 0.7±2.8 (P<0.001), and 0 (P<0.05) cfu/swab, respectively. P. aeruginosa was eliminated from all treated U-bends. CONCLUSION: Automated ECA treatment of washbasin U-bends consistently minimizes microbial contamination.","pmid":"27485396","doi":"10.1016/j.jhin.2016.07.007","url":"https://pubmed.ncbi.nlm.nih.gov/27485396/"},{"id":1498,"title":"Effectiveness of Hypochlorous Acid to Reduce the Biofilms on Titanium Alloy Surfaces in Vitro.","authors":"Chen, Chun-Ju; Chen, Chun-Cheng; Ding, Shinn-Jyh","year":2016,"date":"2016 Jul 19","journal":"International journal of molecular sciences","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Chemotherapeutic agents have been used as an adjunct to mechanical debridement for peri-implantitis treatment. The present in vitro study evaluated and compared the effectiveness of hypochlorous acid (HOCl), sodium hypochlorite (NaOCl), and chlorhexidine (CHX) at eliminating Gram-negative (E. coli and P. gingivalis) and Gram-positive (E. faecalis and S. sanguinis) bacteria. The effect of irrigating volume and exposure time on the antimicrobial efficacy of HOCl was evaluated, and a durability analysis was completed. Live/dead staining, morphology observation, alamarBlue assay, and lipopolysaccharide (LPS) detection were examined on grit-blasted and biofilm-contaminated titanium alloy discs after treatment with the three chemotherapeutic agents. The results indicated that HOCl exhibited better antibacterial efficacy with increasing irrigating volumes. HOCl achieved greater antibacterial efficacy as treatment time was increased. A decrease in antimicrobial effectiveness was observed when HOCl was unsealed and left in contact with the air. All the irrigants showed antibacterial activity and killed the majority of bacteria on the titanium alloy surfaces of biofilm-contaminated implants. Moreover, HOCl significantly lowered the LPS concentration of P. gingivalis when compared with NaOCl and CHX. Thus, a HOCl antiseptic may be effective for cleaning biofilm-contaminated implant surfaces.","pmid":"27447617","doi":"10.3390/ijms17071161","url":"https://pubmed.ncbi.nlm.nih.gov/27447617/"},{"id":1515,"title":"Solanum diploconos fruits: profile of bioactive compounds and in vitro antioxidant capacity of different parts of the fruit.","authors":"Ribeiro, Alessandra Braga; Chisté, Renan Campos; Lima, José L F C; Fernandes, Eduarda","year":2016,"date":"2016 May 18","journal":"Food & function","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Solanum diploconos is an unexploited Brazilian native fruit that belongs to the same genus of important food crops, such as tomato (Solanum lycorpersicum) and potato (Solanum tuberosum). In this study, we determined, for the first time, the profile of bioactive compounds (phenolic compounds, carotenoids, ascorbic acid and tocopherols) of the freeze-dried pulp and peel of Solanum diploconos fruits, as well as of an extract obtained from the whole fruit. Additionally, the antioxidant potential of the whole fruit extract was evaluated in vitro, against reactive oxygen species (ROS) and reactive nitrogen species (RNS). Eighteen phenolic compounds were identified in the peel and pulp and 6 compounds were found in the whole fruit extract. Coumaric, ferulic and caffeic acid derivatives were revealed to be the major phenolic constituents. All-trans-β-carotene was the major carotenoid (17-38 μg g(-1), dry basis), but all-trans-lutein and 9-cis-β-carotene were also identified. The peel and pulp presented <2 μg per mL of tocopherols, and ascorbic acid was not detected. The whole fruit extract exhibited scavenging capacity against all tested ROS and RNS (IC50 = 14-461 μg mL(-1)) with high antioxidant efficiency against HOCl. Thus, Solanum diploconos fruits may be seen as a promising source of bioactive compounds with high antioxidant potential against the most physiologically relevant ROS and RNS.","pmid":"27142444","doi":"10.1039/c6fo00326e","url":"https://pubmed.ncbi.nlm.nih.gov/27142444/"},{"id":1517,"title":"Universal decolonization with hypochlorous solution in a burn intensive care unit in a tertiary care community hospital.","authors":"Gray, Dorinne; Foster, Kevin; Cruz, Abner; Kane, Gail; Toomey, Mike; Bay, Curtis; Kardos, Patricia; Ostovar, Gholamabbas Amin","year":2016,"date":"2016 Sep 1","journal":"American journal of infection control","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Infections are the leading cause of morbidity and mortality in burn patients. Patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) are at higher risk of developing an invasive infection, and MRSA is endemic in many burn units. The typical decolonization regimen of mupirocin and chlorhexidine bathing is not optimal in burn patients because of chlorhexidine limitations on nonintact skin. We studied the impact of universal decolonization using mupirocin and hypochlorous acid bathing on health care-associated MRSA infections in a burn intensive care unit. We show a significant decrease in total MRSA infections.","pmid":"27079244","doi":"10.1016/j.ajic.2016.02.008","url":"https://pubmed.ncbi.nlm.nih.gov/27079244/"},{"id":1518,"title":"Inactivation of bacteria on surfaces by sprayed slightly acidic hypochlorous acid water: in vitro experiments.","authors":"Hakim, Hakimullah; Alam, Md Shahin; Sangsriratanakul, Natthanan; Nakajima, Katsuhiro; Kitazawa, Minori; Ota, Mari; Toyofuku, Chiharu; Yamada, Masashi; Thammakarn, Chanathip; Shoham, Dany; Takehara, Kazuaki","year":2016,"date":"2016 Aug 1","journal":"The Journal of veterinary medical science","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The capacity of slightly acidic hypochlorous acid water (SAHW), in both liquid and spray form, to inactivate bacteria was evaluated as a potential candidate for biosecurity enhancement in poultry production. SAHW (containing 50 or 100 ppm chlorine, pH 6) was able to inactivate Escherichia coli and Salmonella Infantis in liquid to below detectable levels (≤2.6 log10 CFU/ml) within 5 sec of exposure. In addition, SAHW antibacterial capacity was evaluated by spraying it using a nebulizer into a box containing these bacteria, which were present on the surfaces of glass plates and rayon sheets. SAHW was able to inactivate both bacterial species on the glass plates (dry condition) and rayon sheets within 5 min spraying and 5 min contact times, with the exception of 50 ppm SAHW on the rayon sheets. Furthermore, a corrosivity test determined that SAHW does not corrode metallic objects, even at the longest exposure times (83 days). Our findings demonstrate that SAHW is a good candidate for biosecurity enhancement in the poultry industry. Spraying it on the surfaces of objects, eggshells, egg incubators and transport cages could reduce the chances of contamination and disease transmission. These results augment previous findings demonstrating the competence of SAHW as an anti-viral disinfectant.","pmid":"27052464","doi":"10.1292/jvms.16-0075","url":"https://pubmed.ncbi.nlm.nih.gov/27052464/"},{"id":1520,"title":"Linking Inflammation and Parkinson Disease: Hypochlorous Acid Generates Parkinsonian Poisons.","authors":"Jeitner, Thomas M; Kalogiannis, Mike; Krasnikov, Boris F; Gomolin, Irving; Peltier, Morgan R; Moran, Graham R","year":2016,"date":"2016 Jun","journal":"Toxicological sciences : an official journal of the Society of Toxicology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Inflammation is a common feature of Parkinson Disease and other neurodegenerative disorders. Hypochlorous acid (HOCl) is a reactive oxygen species formed by neutrophils and other myeloperoxidase-containing cells during inflammation. HOCl chlorinates the amine and catechol moieties of dopamine to produce chlorinated derivatives collectively termed chlorodopamine. Here, we report that chlorodopamine is toxic to dopaminergic neurons both in vivo and in vitro Intrastriatal administration of 90 nmol chlorodopamine to mice resulted in loss of dopaminergic neurons from the substantia nigra and decreased ambulation-results that were comparable to those produced by the same dose of the parkinsonian poison, 1-methyl-4-phenylpyridinium (MPP+). Chlorodopamine was also more toxic to differentiated SH SY5Y cells than HOCl. The basis of this selective toxicity is likely mediated by chlorodopamine uptake through the dopamine transporter, as expression of this transporter in COS-7 cells conferred sensitivity to chlorodopamine toxicity. Pharmacological blockade of the dopamine transporter also mitigated the deleterious effects of chlorodopamine in vivo The cellular actions of chlorodopamine included inactivation of the α-ketoglutarate dehydrogenase complex, as well as inhibition of mitochondrial respiration. The latter effect is consistent with inhibition of cytochrome c oxidase. Illumination at 670 nm, which stimulates cytochrome c oxidase, reversed the effects of chlorodopamine. The observed changes in mitochondrial biochemistry were also accompanied by the swelling of these organelles. Overall, our findings suggest that chlorination of dopamine by HOCl generates toxins that selectively kill dopaminergic neurons in the substantia nigra in a manner comparable to MPP+.","pmid":"27026709","doi":"10.1093/toxsci/kfw052","url":"https://pubmed.ncbi.nlm.nih.gov/27026709/"},{"id":1523,"title":"Chlorination of Betacyanins in Several Hypochlorous Acid Systems.","authors":"Wybraniec, Sławomir; Starzak, Karolina; Pietrzkowski, Zbigniew","year":2016,"date":"2016 Apr 13","journal":"Journal of agricultural and food chemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"This study presents a comparative evaluation of chlorination of betanin, betanidin, and neobetanin exposed to sodium hypochlorite and myeloperoxidase (MPO)/H2O2/Cl(-) systems. For betanin/betanidin, the chlorination takes place at the aglycone unit, but for neobetanin, no chlorinated products in the reaction mixtures can be detected. In the RP-HPLC system, monochloro-betanin/-betanidin were eluted earlier than their corresponding nonchlorinated substrates. An influence of Cl(-) concentration on betanin/betanidin chlorination efficiency in sodium hypochlorite and MPO systems was investigated. At pH 3-5, the yields of formed monochloro-betanin/-betanidin decrease dramatically at higher Cl(-) concentrations, indicating that generated Cl2 is not the chlorinating agent in the presence of sodium hypochlorite. The intriguing low activity of Cl2 in betanin/betanidin chlorination compared to HOCl and/or Cl2O can be explained by a special position of the attack by molecules of HOCl and/or Cl2O. In the MPO/H2O2/Cl(-) system, the highest efficiency of monochloro-betanin/-betanidin generation is observed at pH 5.","pmid":"26947920","doi":"10.1021/acs.jafc.5b06020","url":"https://pubmed.ncbi.nlm.nih.gov/26947920/"},{"id":1524,"title":"Real-Time Discrimination and Versatile Profiling of Spontaneous Reactive Oxygen Species in Living Organisms with a Single Fluorescent Probe.","authors":"Zhang, Ruilong; Zhao, Jun; Han, Guangmei; Liu, Zhengjie; Liu, Cui; Zhang, Cheng; Liu, Bianhua; Jiang, Changlong; Liu, Renyong; Zhao, Tingting; Han, Ming-Yong; Zhang, Zhongping","year":2016,"date":"2016 Mar 23","journal":"Journal of the American Chemical Society","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Fluorescent probes are powerful tools for the investigations of reactive oxygen species (ROS) in living organisms by visualization and imaging. However, the multiparallel assays of several ROS with multiple probes are often limited by the available number of spectrally nonoverlapping chromophores together with large invasive effects and discrepant biological locations. Meanwhile, the spontaneous ROS profilings in various living organs/tissues are also limited by the penetration capability of probes across different biological barriers and the stability in reactive in vivo environments. Here, we report a single fluorescent probe to achieve the effective discrimination and profiling of hydroxyl radicals (•OH) and hypochlorous acid (HClO) in living organisms. The probe is constructed by chemically grafting an additional five-membered heterocyclic ring and a lateral triethylene glycol chain to a fluorescein mother, which does not only turn off the fluorescence of fluorescein, but also create the dual reactive sites to ROS and the penetration capability in passing through various biological barriers. The reactions of probe with •OH and HClO simultaneously result in cyan and green emissions, respectively, providing the real-time discrimination and quantitative analysis of the two ROS in cellular mitochondria. Surprisingly, the accumulation of probes in the intestine and liver of a normal-state zebrafish and the transfer pathway from intestine-to-blood-to-organ/tissue-to-kidney-to-excretion clearly present the profiling of spontaneous •OH and HClO in these metabolic organs. In particular, the stress generation of •OH at the fresh wound of zebrafish is successfully visualized for the first time, in spite of its extremely short lifetime.","pmid":"26938117","doi":"10.1021/jacs.5b12848","url":"https://pubmed.ncbi.nlm.nih.gov/26938117/"},{"id":1528,"title":"Flow-through Instillation of Hypochlorous Acid in the Treatment of Necrotizing Fasciitis.","authors":"Crew, John R; Thibodeaux, Kerry T; Speyrer, Marcus S; Gauto, Anibal R; Shiau, Timothy; Pang, Liliana; Bley, Keith; Debabov, Dimitri","year":2016,"date":"2016 Feb","journal":"Wounds : a compendium of clinical research and practice","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"INTRODUCTION: Necrotizing fasciitis (NF) is a rare and rapidly progressing bacterial infection of soft tissues. Bacterial toxins cause local tissue damage and necrosis, as well as blunt immune system responses. A self-propagating cycle of bacterial invasion, toxin release and tissue destruction can continue until substantial amounts of tissue become necrotic. Neutralization of bacterial toxins should improve the results. MATERIALS AND METHODS: Pure hypochlorous acid (HOCl) (0.01% w/v) with no sodium hypochlorite impurity in saline pH 4-5, which was recently shown to both eradicate bacteria and neutralize bacterial toxins in vitro, was administered via flowthrough instillation to 6 patients with NF 4-6 times daily as needed. Utilizing a vacuum-assisted closure, 5-10 mL of pure 0.01% HOCl with no sodium hypochlorite impurity was instilled and removed frequently to irrigate the wounds. RESULTS: Of the 6 patients, no deaths or limb amputations occurred. All infected areas healed completely without major complications. CONCLUSION: The toxicity and immune dysfunction caused by bacterial toxins and toxins released from damaged cells may be mitigated by flow-through instillation with saline containing pure 0.01% HOCl with no sodium hypochlorite impurity. Randomized controlled clinical trial research of this relatively simple and inexpensive instillation protocol is suggested for identified cases of NF.","pmid":"26891136","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/26891136/"},{"id":1529,"title":"Germicide wound pad with active, in situ, electrolytically produced hypochlorous acid.","authors":"Rubinsky, L; Patrick, B; Mikus, P; Rubinsky, B","year":2016,"date":"2016 Apr","journal":"Biomedical microdevices","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"We describe a new wound dressing technology that can actively generate an inorganic germicide agent, in situ, within the wound pad. The technology provides real time control over the quantitative, spatial and temporal delivery of the germicide. The identity of the germicide is hypochlorous acid (HClO). The HClO is produced in a flexible wound pad, made of a composite of thin (micrometer scale) layers of various materials, with different electrochemical properties that enhance HClO production. Active control over the production of HClO is achieved by control of the pH and of the electric potential across the layers. The effectiveness of the Active HClO Pad (AHClOP) concept is demonstrated in a study on sterilization of E. coli in a deep wound contamination simulating gel. The performance of the AHClOP is compared with that of four commercial wound dressings. Results show that the AHClOP can sterilize throughout the gel, while the commercial dressings cannot.","pmid":"26888442","doi":"10.1007/s10544-016-0052-4","url":"https://pubmed.ncbi.nlm.nih.gov/26888442/"},{"id":1537,"title":"TrpA1 Regulates Defecation of Food-Borne Pathogens under the Control of the Duox Pathway.","authors":"Du, Eun Jo; Ahn, Tae Jung; Kwon, Ilmin; Lee, Ji Hye; Park, Jeong-Ho; Park, Sun Hwa; Kang, Tong Mook; Cho, Hana; Kim, Tae Jin; Kim, Hyung-Wook; Jun, Youngsoo; Lee, Hee Jae; Lee, Young Sik; Kwon, Jae Young; Kang, KyeongJin","year":2016,"date":"2016 Jan","journal":"PLoS genetics","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Pathogen expulsion from the gut is an important defense strategy against infection, but little is known about how interaction between the intestinal microbiome and host immunity modulates defecation. In Drosophila melanogaster, dual oxidase (Duox) kills pathogenic microbes by generating the microbicidal reactive oxygen species (ROS), hypochlorous acid (HOCl) in response to bacterially excreted uracil. The physiological function of enzymatically generated HOCl in the gut is, however, unknown aside from its anti-microbial activity. Drosophila TRPA1 is an evolutionarily conserved receptor for reactive chemicals like HOCl, but a role for this molecule in mediating responses to gut microbial content has not been described. Here we identify a molecular mechanism through which bacteria-produced uracil facilitates pathogen-clearing defecation. Ingestion of uracil increases defecation frequency, requiring the Duox pathway and TrpA1. The TrpA1(A) transcript spliced with exon10b (TrpA1(A)10b) that is present in a subset of midgut enteroendocrine cells (EECs) is critical for uracil-dependent defecation. TRPA1(A)10b heterologously expressed in Xenopus oocytes is an excellent HOCl receptor characterized with elevated sensitivity and fast activation kinetics of macroscopic HOCl-evoked currents compared to those of the alternative TRPA1(A)10a isoform. Consistent with TrpA1's role in defecation, uracil-excreting Erwinia carotovora showed higher persistence in TrpA1-deficient guts. Taken together, our results propose that the uracil/Duox pathway promotes bacteria expulsion from the gut through the HOCl-sensitive receptor, TRPA1(A)10b, thereby minimizing the chances that bacteria adapt to survive host defense systems.","pmid":"26726767","doi":"10.1371/journal.pgen.1005773","url":"https://pubmed.ncbi.nlm.nih.gov/26726767/"},{"id":1538,"title":"Virus removal and integrity in aged RO membranes.","authors":"Pype, Marie-Laure; Donose, Bogdan C; Martí, Llucia; Patureau, Dominique; Wery, Nathalie; Gernjak, Wolfgang","year":2016,"date":"2016 Mar 1","journal":"Water research","category":"Materials & industrial applications","evidence":"Journal article / other","relevance":"Medium","abstract":"Membrane ageing reduces the quality of the filtered water. Therefore, in order to warrant public health, monitoring membrane performances are of utmost importance. Reverse osmosis (RO) membranes are generally used to remove viruses and salt. However, there is no detailed study demonstrating the impact of aged membrane on the rejection of viruses and of membrane integrity indicators. In this paper, the impact of hypochlorite induced RO ageing on the rejection of a virus surrogate (MS2 phage) and four membrane integrity indicators (salt, dissolved organic matter, rhodamine WT and sulphate) was evaluated. Hypochlorite exposure was either active (under filtration) or passive (soaking), and the changes of the membrane surface chemistry were characterised using several autopsy techniques. Under this accelerated ageing condition, the introduction of chlorine in the membrane chemistry and the breakage of amide bonds caused an increase of the water permeability and a decrease of the virus surrogate's and indicators' rejection. Ageing resulted in a more negatively charged membrane and also in a higher hydrophobicity, which lead to the adsorption of MS2 phage. Despite severe physical membrane damage leading to a reduction of salt rejection to 1.2 log (94%), the minimum rejection of MS2 phage stayed on or above 4 log.","pmid":"26724450","doi":"10.1016/j.watres.2015.12.023","url":"https://pubmed.ncbi.nlm.nih.gov/26724450/"},{"id":1540,"title":"Unexpected products of the hypochlorous acid-induced oxidation of oleic acid: A study using high performance thin-layer chromatography-electrospray ionization mass spectrometry.","authors":"Schröter, Jenny; Griesinger, Hans; Reuÿ, Eyla; Schulz, Michael; Riemer, Thomas; Süÿ, Rosmarie; Schiller, Jürgen; Fuchs, Beate","year":2016,"date":"2016 Mar 25","journal":"Journal of chromatography. A","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Reactive oxygen species (ROS) play important physiological roles and are of particular relevance in the pathogenesis of inflammatory diseases. At inflammatory conditions, the enzyme myeloperoxidase generates hypochlorous acid (HOCl) which adds to the double bonds of fatty acyl residues of (phospho)lipids under the formation of chlorohydrins. This may lead to the development of many inflammatory diseases, such as atherosclerosis or arthritis, if the ROS generation exceeds a certain extent. Using oleic acid as the simplest unsaturated fatty acid which contains just a single double bond, as a model system, we investigated all products - including the chlorohydrin - after its reaction with HOCl by a combination of thin-layer chromatography and electrospray ionization mass spectrometry. Unlike the general acceptance, the reaction of oleic acid and HOCl leads not exclusively to the formation of chlorohydrin (isomers) but is much more complex: there are also considerable amounts of dimeric and (to a minor extent) trimeric products which can be assigned to isomeric ethers and esters. The obtained products after oleic acid chlorination were also compared with the reaction products of 1-palmitoyl-2-oleoyl-sn-phosphatidylcholine (POPC) and HOCl. The reasons why different products are obtained will be discussed and the involvement of the carboxylic acid emphasized.","pmid":"26700153","doi":"10.1016/j.chroma.2015.11.059","url":"https://pubmed.ncbi.nlm.nih.gov/26700153/"},{"id":1541,"title":"Serotonin as a putative scavenger of hypohalous acid in the brain.","authors":"Kalogiannis, Mike; Delikatny, E James; Jeitner, Thomas M","year":2016,"date":"2016 Apr","journal":"Biochimica et biophysica acta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Neurodegenerative disorders represent the culmination of numerous insults including oxidative stress. The long etiology of most of these disorders suggests that lessening the effects of one or more of the insults could significantly delay disease onset. Antioxidants have been tested as possible therapeutics for neurodegenerative disorders, but with little success. Here we report that serotonin acts as a scavenger of hypochlorous acid (HOCl) in the brain. Serotonin was shown to prevent the oxidation of 2-thio-5-nitrobenzoate by HOCl in a biphasic manner. The first phase was a partial scavenging that occurred at concentrations of serotonin that exceeded those of HOCl. (1)H-NMR studies indicated that HOCl chlorinates both the aryl and akyl nitrogen atoms of serotonin. Thus, the oxidation of 2-thio-5-nitrobenzoate that occurred during the first phase of scavenging is likely due to the formation of serotonergic chloramines. A second phase of scavenging occurred at concentrations of HOCl that exceeded those of serotonin. Under these conditions, the chlorinated serotonin polymerized and formed inert aggregates. Serotonin was further shown to prevent the loss of cells and cellular α-ketoglutarate dehydrogenase complex activity caused by HOCl. Extracellular concentrations of serotonin in the brain can be elevated with selective serotonin reuptake inhibitors and suggests that such compounds could be used to increase the cerebral antioxidant capacity. Acute administration of selective serotonin reuptake inhibitors to mice treated with endotoxin partially mitigated sickness behavior and protein chlorination in the brain. These observations suggest that serotonin may act to suppress chlorinative stress in the brain.","pmid":"26699077","doi":"10.1016/j.bbadis.2015.12.012","url":"https://pubmed.ncbi.nlm.nih.gov/26699077/"},{"id":1544,"title":"Viability and Effects on Bacterial Proteins by Oral Rinses with Hypochlorous Acid as Active Ingredient.","authors":"Castillo, Diana Marcela; Castillo, Yormaris; Delgadillo, Nathaly Andrea; Neuta, Yineth; Jola, Johana; Calderón, Justo Leonardo; Lafaurie, Gloria Inés","year":2015,"date":"2015 Oct","journal":"Brazilian dental journal","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"This study investigated the effect of hypochlorous acid (HOCl) rinses and chlorhexidine (CHX) on the bacterial viability of S. mutans, A. israelii, P. gingivalis, A. actinomycetemcomitans, E. corrodens, C. rectus, K. oxytoca, K. pneumoniae and E. cloacae. The percentage of live bacteria was tested by fluorescence method using Live/Dead kit(r) and BacLight (Molecular Probes(r)) and compared between groups by the Kruskal-Wallis and U Mann-Whitney tests with Bonferroni correction (p value<0.012). The effect of HOCl and CHX on total proteins of P. gingivalis and S. mutans was determined by SDS-PAGE. CHX showed a higher efficacy than HOCl against S. mutans, A. israelii, E. corrodens and E. cloacae (p<0.001) while HOCl was more effective than CHX against P. gingivalis, A. actinomycetemcomitans, C. rectus and K. oxytoca (p=0.001). CHX and HOCl had similar efficacy against K. pneumoniae. Proteins of P. gingivalis and S. mutans were affected similarly by HOCl and CHX. HOCl reduced the bacterial viability especially in periodontopathic bacteria, which may support its use in the control of subgingival biofilm in periodontal patients.","pmid":"26647939","doi":"10.1590/0103-6440201300388","url":"https://pubmed.ncbi.nlm.nih.gov/26647939/"},{"id":1545,"title":"Repairing oxidized proteins in the bacterial envelope using respiratory chain electrons.","authors":"Gennaris, Alexandra; Ezraty, Benjamin; Henry, Camille; Agrebi, Rym; Vergnes, Alexandra; Oheix, Emmanuel; Bos, Julia; Leverrier, Pauline; Espinosa, Leon; Szewczyk, Joanna; Vertommen, Didier; Iranzo, Olga; Collet, Jean-François; Barras, Frédéric","year":2015,"date":"2015 Dec 17","journal":"Nature","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"The reactive species of oxygen and chlorine damage cellular components, potentially leading to cell death. In proteins, the sulfur-containing amino acid methionine is converted to methionine sulfoxide, which can cause a loss of biological activity. To rescue proteins with methionine sulfoxide residues, living cells express methionine sulfoxide reductases (Msrs) in most subcellular compartments, including the cytosol, mitochondria and chloroplasts. Here we report the identification of an enzymatic system, MsrPQ, repairing proteins containing methionine sulfoxide in the bacterial cell envelope, a compartment particularly exposed to the reactive species of oxygen and chlorine generated by the host defence mechanisms. MsrP, a molybdo-enzyme, and MsrQ, a haem-binding membrane protein, are widely conserved throughout Gram-negative bacteria, including major human pathogens. MsrPQ synthesis is induced by hypochlorous acid, a powerful antimicrobial released by neutrophils. Consistently, MsrPQ is essential for the maintenance of envelope integrity under bleach stress, rescuing a wide series of structurally unrelated periplasmic proteins from methionine oxidation, including the primary periplasmic chaperone SurA. For this activity, MsrPQ uses electrons from the respiratory chain, which represents a novel mechanism to import reducing equivalents into the bacterial cell envelope. A remarkable feature of MsrPQ is its capacity to reduce both rectus (R-) and sinister (S-) diastereoisomers of methionine sulfoxide, making this oxidoreductase complex functionally different from previously identified Msrs. The discovery that a large class of bacteria contain a single, non-stereospecific enzymatic complex fully protecting methionine residues from oxidation should prompt a search for similar systems in eukaryotic subcellular oxidizing compartments, including the endoplasmic reticulum.","pmid":"26641313","doi":"10.1038/nature15764","url":"https://pubmed.ncbi.nlm.nih.gov/26641313/"},{"id":1546,"title":"Aerosol Disinfection Capacity of Slightly Acidic Hypochlorous Acid Water Towards Newcastle Disease Virus in the Air: An In Vivo Experiment.","authors":"Hakim, Hakimullah; Thammakarn, Chanathip; Suguro, Atsushi; Ishida, Yuki; Nakajima, Katsuhiro; Kitazawa, Minori; Takehara, Kazuaki","year":2015,"date":"2015 Dec","journal":"Avian diseases","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Existence of bioaerosol contaminants in farms and outbreaks of some infectious organisms with the ability of transmission by air increase the need for enhancement of biosecurity, especially for the application of aerosol disinfectants. Here we selected slightly acidic hypochlorous acid water (SAHW) as a candidate and evaluated its virucidal efficacy toward a virus in the air. Three-day-old conventional chicks were challenged with 25 doses of Newcastle disease live vaccine (B1 strain) by spray with nebulizer (particle size <3 μm in diameter), while at the same time reverse osmosis water as the control and SAHW containing 50 or 100 parts per million (ppm) free available chlorine in pH 6 were sprayed on the treated chicks with other nebulizers. Exposed chicks were kept in separated cages in an isolator and observed for clinical signs. Oropharyngeal swab samples were collected from 2 to 5 days postexposure from each chick, and then the samples were titrated with primary chicken kidney cells to detect the virus. Cytopathic effects were observed, and a hemagglutination test was performed to confirm the result at 5 days postinoculation. Clinical signs (sneezing) were recorded, and the virus was isolated from the control and 50 ppm treatment groups, while no clinical signs were observed in and no virus was isolated from the 100 ppm treatment group. The virulent Newcastle disease virus (NDV) strain Sato, too, was immediately inactivated by SAHW containing 50 ppm chlorine in the aqueous phase. These data suggest that SAHW containing 100 ppm chlorine can be used for aerosol disinfection of NDV in farms.","pmid":"26629621","doi":"10.1637/11107-042115-Reg.1","url":"https://pubmed.ncbi.nlm.nih.gov/26629621/"},{"id":1550,"title":"Silica Gel for Enhanced Activity and Hypochlorite Protection of Cyanuric Acid Hydrolase in Recombinant Escherichia coli.","authors":"Radian, Adi; Aukema, Kelly G; Aksan, Alptekin; Wackett, Lawrence P","year":2015,"date":"2015 Nov 3","journal":"mBio","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Chlorinated isocyanuric acids are widely used water disinfectants that generate hypochlorite, but with repeated application, they build up cyanuric acid (CYA) that must be removed to maintain disinfection. 3-Aminopropyltriethoxysilane (APTES)-treated Escherichia coli cells expressing cyanuric acid hydrolase (CAH) from Moorella thermoacetica exhibited significantly high CYA degradation rates and provided protection against enzyme inactivation by hypochlorite (chlorine). APTES coating or encapsulation of cells had two benefits: (i) overcoming diffusion limitations imposed by the cell wall and (ii) protecting against hypochlorite inactivation of CAH activity. Cells encapsulated in APTES gels degraded CYA three times faster than nonfunctionalized tetraethoxysilane (TEOS) gels, and cells coated with APTES degraded CYA at a rate of 29 µmol/min per mg of CAH protein, similar to the rate with purified enzyme. UV spectroscopy, fluorescence spectroscopy, and scanning electron microscopy showed that the higher rates were due to APTES increasing membrane permeability and enhancing cyanuric acid diffusion into the cytoplasm to reach the CAH enzyme. Purified CAH enzyme was shown to be rapidly inactivated by hypochlorite. APTES aggregates surrounding cells protected via the amine groups reacting with hypochlorite as shown by pH changes, zeta potential measurements, and infrared spectroscopy. APTES-encapsulated E. coli cells expressing CAH degraded cyanuric acid at high rates in the presence of 1 to 10 ppm hypochlorite, showing effectiveness under swimming pool conditions. In contrast, CAH activity in TEOS gels or free cells was completely inactivated by hypochlorite. These studies show that commercially available silica materials can selectively enhance, protect, and immobilize whole-cell biocatalysts for specialized applications. IMPORTANCE: Hypochlorite is used in vast quantities for water disinfection, killing bacteria on surfaces, and washing and whitening. In pools, spas, and other waters, hypochlorite is frequently delivered as chlorinated isocyanuric acids that release hypochlorite and cyanuric acid. Over time, cyanuric acid accumulates and impairs disinfection and must be removed. The microbial enzyme cyanuric acid hydrolase can potentially remove cyanuric acid to restore disinfection and protect swimmers. Whole bacterial cells expressing cyanuric acid hydrolase were encapsulated in an inert silica matrix containing an amine group. The amine group serves to permeabilize the cell membrane and accelerate cyanuric acid degradation, and it also reacts with hypochlorite to protect against inactivation of cyanuric acid hydrolase. Methods for promoting whole-cell biocatalysis are important in biotechnology, and the present work illustrates approaches to enhance rates and protect against an inhibitory substance.","pmid":"26530383","doi":"10.1128/mBio.01477-15","url":"https://pubmed.ncbi.nlm.nih.gov/26530383/"},{"id":1551,"title":"The role of vascular peroxidase 1 in ox-LDL-induced vascular smooth muscle cell calcification.","authors":"Tang, Yixin; Xu, Qian; Peng, Haiyang; Liu, Zhaoya; Yang, Tianlun; Yu, Zaixin; Cheng, Guangjie; Li, Xiaohui; Zhang, Guogang; Shi, Ruizheng","year":2015,"date":"2015 Dec","journal":"Atherosclerosis","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Reactive oxygen species (ROS)-induced osteogenic differentiation of vascular smooth muscle cells (VSMCs) is associated with the pathogenesis of vascular calcification. Vascular peroxidase 1 (VPO1), a peroxidase in the cardiovascular system, utilizes the hydrogen peroxide (H2O2) produced by co-expressed NADPH oxidases to produce hypochlorous acid (HOCl) and catalyze peroxidative reactions. The aim of this study was to determine whether VPO1 plays a role in the osteogenic differentiation of VSMCs in the setting of the vascular calcification induced by oxidized low-density lipoprotein (ox-LDL). In cultured primary rat VSMCs, we observed that the expression of VPO1 was significantly increased in combination with increases in calcification, as demonstrated via increased mineralization, as well as increased alkaline phosphatase (ALP) activity and up-regulated runt-related transcription factor 2 (Runx2) expression in ox-LDL-treated cells. Ox-LDL-induced VSMC calcification and Runx2 expression were both inhibited by knockdown of VPO1 using a small interfering RNA or by an NADPH oxidase inhibitor. Moreover, the knockdown of VPO1 in VSMCs suppressed the production of HOCl and the phosphorylation of AKT, ERK and P38 MAPK. Furthermore, HOCl treatment facilitated the phosphorylation of AKT, ERK1/2 and P38 MAPK and the expression of Runx2, whereas LY294002 (a specific inhibitor of PI3K), U0126 (a specific inhibitor of ERK1/2) and SB203580 (a specific inhibitor of P38 MAPK) significantly attenuated the HOCl-induced up-regulation of Runx2. Collectively, these results demonstrated that VPO1 promotes ox-LDL-induced VSMC calcification via the VPO1/HOCl/PI3K/AKT, ERK1/2, and P38 MAPK/Runx2 signaling pathways.","pmid":"26520887","doi":"10.1016/j.atherosclerosis.2015.08.047","url":"https://pubmed.ncbi.nlm.nih.gov/26520887/"},{"id":1553,"title":"Novel Electrokinetic Microfluidic Detector for Evaluating Effectiveness of Microalgae Disinfection in Ship Ballast Water.","authors":"Maw, Myint Myint; Wang, Junsheng; Li, Fabo; Jiang, Jinhu; Song, Younan; Pan, Xinxiang","year":2015,"date":"2015 Oct 26","journal":"International journal of molecular sciences","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Ship ballast water treatment methods face many technical challenges. The effectiveness of every treatment method usually is evaluated by using large scale equipment and a large volume of samples, which involves time-consuming, laborious, and complex operations. This paper reports the development of a novel, simple and fast platform of methodology in evaluating the efficiency and the best parameters for ballast water treatment systems, particularly in chemical disinfection. In this study, a microfluidic chip with six sample wells and a waste well was designed, where sample transportation was controlled by electrokinetic flow. The performance of this microfluidic platform was evaluated by detecting the disinfection of Dunaliella salina (D. salina) algae in ballast water treated by sodium hypochlorite (NaClO) solution. Light-induced chlorophyll fluorescence (LICF) intensity was used to determine the viability of microalgae cells in the system, which can be operated automatically with the dimension of the detector as small as 50 mm × 24 mm × 5 mm. The 40 µL volume of sample solution was used for each treatment condition test and the validity of detection can be accomplished within about five min. The results show that the viability of microalgae cells under different treatment conditions can be determined accurately and further optimal treatment conditions including concentrations of NaClO and treatment time can also be obtained. These results can provide accurate evaluation and optimal parameters for ballast water treatment methods.","pmid":"26516836","doi":"10.3390/ijms161025560","url":"https://pubmed.ncbi.nlm.nih.gov/26516836/"},{"id":1556,"title":"Fungal Infections After Boston Type 1 Keratoprosthesis Implantation: Literature Review and In Vitro Antifungal Activity of Hypochlorous Acid.","authors":"Odorcic, Silvia; Haas, Wolfgang; Gilmore, Michael S; Dohlman, Claes H","year":2015,"date":"2015 Dec","journal":"Cornea","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"PURPOSE: To review the current literature describing cases of fungal keratitis and endophthalmitis after Boston keratoprosthesis (KPro) implantation and to characterize the antifungal activity of 0.01% hypochlorous acid against medically relevant fungi. METHODS: A literature review of fungal keratitis or endophthalmitis in KPro patients from January 2001 to April 2015, and an in vitro time kill assay characterizing the fungicidal activity of 0.01% hypochlorous acid against fungi causing ocular infections. RESULTS: Fifteen publications, predominantly retrospective case series, were identified. Infection rates after KPro implantation ranged from 0.009 to 0.02 fungal infections per patient-year of follow-up. The largest single-surgeon series reported an incidence of 2.4% for fungal endophthalmitis during a 10-year period. Causative organisms included both yeasts and molds. Outcomes were favorable if infections were caught early and treated appropriately; less favorable outcomes were reported in developing countries where fungal species are endemic and resources are limited. 0.01% hypochlorous acid is rapidly fungicidal, reducing the number of viable yeast cells or mold conidia by at least 99.99% within 60 seconds. The antifungal activity extended to all molds (Acremonium kiliense, Aspergillus flavus, Aspergillus fumigatus, Fusarium solani, and Mucor indicus) and yeast species (Candida albicans and Candida parapsilosis) tested. CONCLUSIONS: Fungal infections remain a lifelong concern in patients after KPro implantation. There is a growing need for a standard antifungal prophylaxis regimen, especially in the developing world. The rapid broad-spectrum in vitro fungicidal activity of 0.01% hypochlorous acid against all fungi tested makes it an attractive candidate as an antifungal prophylaxis in KPro patients.","pmid":"26488624","doi":"10.1097/ICO.0000000000000639","url":"https://pubmed.ncbi.nlm.nih.gov/26488624/"},{"id":1557,"title":"A computational study of the chlorination and hydroxylation of amines by hypochlorous acid.","authors":"Šakić, Davor; Hanževački, Marko; Smith, David M; Vrček, Valerije","year":2015,"date":"2015 Dec 28","journal":"Organic & biomolecular chemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The reactions of hypochlorous acid (HOCl) with ammonia, (di)methylamine, and heterocyclic amines have been studied computationally using double-hybrid DFT methods (B2PLYP-D and BK-PLYP) and a G3B3 composite scheme. In the gas phase the calculated energy barriers for N- and/or C-hydroxylation are ca. 100 kJ mol(-1) lower than the barrier for N-chlorination of amines. In the model solvent, however, the latter process becomes kinetically more favored. The explicit solvent effects are crucial for determination of the reaction mechanism. The N-chlorination is extremely susceptible to the presence of explicit water molecules, while no beneficial solvation effect has been found for the N- or C-hydroxylation of amines. The origin of the observed solvent effects arises from differential solvation of the respective transition states for chlorine- and oxygen-transfers, respectively. The nature of solvation of the transition state structures has been explored in more detail by classical molecular dynamics (MD) simulation. In agreement with the quantum mechanical approach, the most stable structural motif, which includes the amine, HOCl, and two reactive waters, has been identified during the MD simulation. The inclusion of 5 or 6 explicit water molecules is required to reproduce the experimental barriers for HOCl-induced formation of N-chloramines in an aqueous environment.","pmid":"26486691","doi":"10.1039/c5ob01823d","url":"https://pubmed.ncbi.nlm.nih.gov/26486691/"},{"id":1560,"title":"Specific role of taurine in the 8-brominated-2'-deoxyguanosine formation.","authors":"Asahi, Takashi; Nakamura, Yoshimasa; Kato, Yoji; Osawa, Toshihiko","year":2015,"date":"2015 Nov 15","journal":"Archives of biochemistry and biophysics","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"At the sites of inflammation, hypohalous acids, such as hypochlorous acid and hypobromous acid (HOBr), are produced by myeloperoxidase. These hypohalous acids rapidly react with the primary amino groups to produce haloamines, which are relatively stable and can diffuse long distances and cross the plasma membrane. In this study, we examined the effects of taurine, the most abundant free amino acid in the leukocyte cytosol, on the hypohalous acid-dependent formation of 8-chloro-2'-deoxyguanosine (8-CldG) and 8-bromo-2'-deoxyguanosine (8-BrdG). The reaction of taurine with HOBr yielded taurine bromamine, which is the most stable among other bromamines of amino acids. Taurine also enhanced the bromination of only dG among the four 2'-deoxynucleosides, whereas it inhibited the 8-CldG formation. The specificity of taurine for the enhanced formation of halogenated dG is completely different from that of nicotine, an enhancer of chlorination. The amount of dibrominated taurine (taurine dibromamine) closely correlated with the formation of 8-BrdG, suggesting that taurine dibromamine might be a plausible mediator for the dG bromination in vivo.","pmid":"26456401","doi":"10.1016/j.abb.2015.10.002","url":"https://pubmed.ncbi.nlm.nih.gov/26456401/"},{"id":1562,"title":"Amide Link Scission in the Polyamide Active Layers of Thin-Film Composite Membranes upon Exposure to Free Chlorine: Kinetics and Mechanisms.","authors":"Powell, Joshua; Luh, Jeanne; Coronell, Orlando","year":2015,"date":"2015 Oct 20","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The volume-averaged amide link scission in the aromatic polyamide active layer of a reverse osmosis membrane upon exposure to free chlorine was quantified at a variety of free chlorine exposure times, concentrations, and pH and rinsing conditions. The results showed that (i) hydroxyl ions are needed for scission to occur, (ii) hydroxide-induced amide link scission is a strong function of exposure to hypochlorous acid, (iii) the ratio between amide links broken and chlorine atoms taken up increased with the chlorination pH and reached a maximum of ∼25%, (iv) polyamide disintegration occurs when high free chlorine concentrations, alkaline conditions, and high exposure times are combined, (v) amide link scission promotes further chlorine uptake, and (vi) scission at the membrane surface is unrepresentative of volume-averaged scission in the active layer. Our observations are consistent with previously proposed mechanisms describing amide link scission as a result of the hydrolysis of the N-chlorinated amidic N-C bond due to nucleophilic attack by hydroxyl ions. This study increases the understanding of the physicochemical changes that could occur for membranes in treatment plants using chlorine as an upstream disinfectant and the extent and rate at which those changes would occur.","pmid":"26394532","doi":"10.1021/acs.est.5b02110","url":"https://pubmed.ncbi.nlm.nih.gov/26394532/"},{"id":1566,"title":"Observation of the multiple halogenation of peptides in the electrospray ionization source.","authors":"Kostyukevich, Yury; Zhdanova, Ekaterina; Kononikhin, Alexey; Popov, Igor; Kukaev, Eugene; Nikolaev, Eugene","year":2015,"date":"2015 Jul","journal":"Journal of mass spectrometry : JMS","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The chlorination of peptides and proteins is an important posttranslational modification, which is a physiological signature of an enzyme myeloperoxidase and can serve as a potential biomarker of some diseases (Parkinson's disease, Alzheimer's disease, etc.). The quantification of the chlorinated peptides has been very challenging in part due to their low levels and artifacts associated with sample preparation. One of the most convenient and promising methods to detect and investigate the chlorinated peptides in the biological samples is the electrospray ionization (ESI) mass spectrometry coupled to the fragmentation techniques (collision-induced dissociation and electron capture dissociation/electron transfer dissociation). We have shown that if the chlorine anions are present in the solution, then the peptide can undergo the chlorination during the ESI ionization. The effect was found to depend on the values of electric potentials of metal parts of the ESI interface. It was found that the grounding of ESI syringe results in the formation of an additional electric loop leading to the electrolytic production of Cl2 and as a consequence the hypochlorous acid inside the ESI needle. Hypochlorous acid reacts with amino groups of peptides and proteins producing chloramine or causing the protein cleavage. In the paper, it is shown on the example of the solution of the several peptides in the presence of HCl that by manipulating the ESI syringe potential, it is possible to create complexes with up to five Cl atoms for sample peptides when the ESI is operated in the positive mode.","pmid":"26349644","doi":"10.1002/jms.3599","url":"https://pubmed.ncbi.nlm.nih.gov/26349644/"},{"id":1571,"title":"Kinetic Analysis of Haloacetonitrile Stability in Drinking Waters.","authors":"Yu, Yun; Reckhow, David A","year":2015,"date":"2015 Sep 15","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Haloacetonitriles (HANs) are an important class of drinking water disinfection byproducts (DBPs) that are reactive and can undergo considerable transformation on time scales relevant to system distribution (i.e., from a few hours to a week or more). The stability of seven mono-, di-, and trihaloacetonitriles was examined under a variety of conditions including different pH levels and disinfectant doses that are typical of drinking water distribution systems. Results indicated that hydroxide, hypochlorite, and their protonated forms could react with HANs via nucleophilic attack on the nitrile carbon, forming the corresponding haloacetamides (HAMs) and haloacetic acids (HAAs) as major reaction intermediates and end products. Other stable intermediate products, such as the N-chloro-haloacetamides (N-chloro-HAMs), may form during the course of HAN chlorination. A scheme of pathways for the HAN reactions was proposed, and the rate constants for individual reactions were estimated. Under slightly basic conditions, hydroxide and hypochlorite are primary reactants and their associated second-order reaction rate constants were estimated to be 6 to 9 orders of magnitude higher than those of their protonated conjugates (i.e., neutral water and hypochlorous acid), which are much weaker but more predominant nucleophiles at neutral and acidic pHs. Developed using the estimated reaction rate constants, the linear free energy relationships (LFERs) summarized the nucleophilic nature of HAN reactions and demonstrated an activating effect of the electron withdrawing halogens on nitrile reactivity, leading to decreasing HAN stability with increasing degree of halogenation of the substituents, while subsequent shift from chlorine to bromine atoms has a contrary stabilizing effect on HANs. The chemical kinetic model together with the reaction rate constants that were determined in this work can be used for quantitative predictions of HAN concentrations depending on pH and free chlorine contact times (CTs), which can be applied as an informative tool by drinking water treatment and system management engineers to better control these emerging nitrogenous DBPs, and can also be significant in making regulatory decisions.","pmid":"26275044","doi":"10.1021/acs.est.5b02772","url":"https://pubmed.ncbi.nlm.nih.gov/26275044/"},{"id":1576,"title":"Removal of caffeine from aqueous solution by indirect electrochemical oxidation using a graphite-PVC composite electrode: A role of hypochlorite ion as an oxidising agent.","authors":"Al-Qaim, Fouad F; Mussa, Zainab H; Othman, Mohamed R; Abdullah, Md P","year":2015,"date":"2015 Dec 30","journal":"Journal of hazardous materials","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The electrochemical oxidation of caffeine, a widely over-the-counter stimulant drug, has been investigated in effluent wastewater and deionized water (DIW) using graphite-poly vinyl chloride (PVC) composite electrode as anode. Effects of initial concentration of caffeine, chloride ion (Cl(-)) loading, presence of hydrogen peroxide (H2O2), sample volume, type of sample and applied voltage were determined to test and to validate a kinetic model for the oxidation of caffeine by the electrochemical oxidation process. The results revealed that the electrochemical oxidation rates of caffeine followed pseudo first-order kinetics, with rate constant values ranged from 0.006 to 0.23 min(-1) depending on the operating parameters. The removal efficiency of caffeine increases with applied voltage very significantly, suggesting a very important role of mediated oxidation process. However, the consumption energy was considered during electrochemical oxidation process. In chloride media, removal of caffeine is faster and more efficiently, although occurrence of more intermediates takes place. The study found that the adding H2O2 to the NaCl solution will inhibit slightly the electrochemical oxidation rate in comparison with only NaCl in solution. Liquid chromatography-time of flight-mass spectrometry (LC-TOF-MS) technique was applied to the identification of the by-products generated during electrochemical oxidation, which allowed to construct the proposed structure of by-products.","pmid":"26218306","doi":"10.1016/j.jhazmat.2015.07.007","url":"https://pubmed.ncbi.nlm.nih.gov/26218306/"},{"id":1579,"title":"Control of Salmonella Cross-Contamination between Green Round Tomatoes in a Model Flume System.","authors":"Gereffi, Scott; Sreedharan, Aswathy; Schneider, Keith R","year":2015,"date":"2015 Jul","journal":"Journal of food protection","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Tomato Best Management Practices require Florida packers to treat tomatoes in a flume system containing at least 150 ppm of free chlorine or other approved sanitizer. However, research is needed to determine the ability of these sanitizers to prevent the transfer of pathogens from contaminated to uncontaminated tomatoes, particularly under realistic packinghouse conditions. The goal of this research was to assess the minimum levels of sanitizer needed to prevent Salmonella cross-contamination between tomatoes in a model flume system under clean conditions and conditions where organic matter was added. Inoculated tomatoes (ca. 8.3 log CFU per tomato) were treated along with uninoculated tomatoes in a model flume system containing 0, 10, or 25 ppm of hypochlorous acid (HOCl) under organic loading conditions of 0, 500, or 4,000 ppm of chemical oxygen demand (COD). In the absence of HOCl, uninoculated tomatoes were highly contaminated (ca. 5 log CFU per tomato) by 15 s. No contamination was detectable (<2 log CFU per tomato) on uninoculated tomatoes when HOCl was present, except with 10 ppm at 4,000 ppm of COD, suggesting failure of 10 ppm of HOCl as a sanitizer under very high organic loading conditions. In the presence of HOCl or peroxyacetic acid, Salmonella was undetectable (<1 log CFU/ml) in the model flume water samples after 2 and 30 s, respectively. Upon enrichment, none of the uninoculated tomatoes treated with 25 ppm of HOCl for 120 s were positive for Salmonella, even in the presence of organic loading at 500 ppm of COD. Based on these findings, 25 ppm of HOCl may be adequate to prevent cross-contamination when the concentration is properly maintained, COD does not exceed 500 ppm, and tomatoes are treated for at least 120 s. Further validation in a larger commercial setting and using higher organic loading levels is necessary because managing HOCl at this low concentration is difficult, especially in a recirculating system. The use of less sanitizer by packers could reduce chemical and disposal costs.","pmid":"26197278","doi":"10.4315/0362-028X.JFP-14-524","url":"https://pubmed.ncbi.nlm.nih.gov/26197278/"},{"id":1585,"title":"Do pH and flavonoids influence hypochlorous acid-induced catalase inhibition and heme modification?","authors":"Krych-Madej, Justyna; Gebicka, Lidia","year":2015,"date":"2015 Sep","journal":"International journal of biological macromolecules","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCl), highly reactive oxidizing and chlorinating species, is formed in the immune response to invading pathogens by the reaction of hydrogen peroxide with chloride catalyzed by the enzyme myeloperoxidase. Catalase, an important antioxidant enzyme, catalyzing decomposition of hydrogen peroxide to water and molecular oxygen, hampers in vitro HOCl formation, but is also one of the main targets for HOCl. In this work we have investigated HOCl-induced catalase inhibition at different pH, and the influence of flavonoids (catechin, epigallocatechin gallate and quercetin) on this process. It has been shown that HOCl-induced catalase inhibition is independent on pH in the range 6.0-7.4. Preincubation of catalase with epigallocatechin gallate and quercetin before HOCl treatment enhances the degree of catalase inhibition, whereas catechin does not affect this process. Our rapid kinetic measurements of absorption changes around the heme group have revealed that heme modification by HOCl is mainly due to secondary, intramolecular processes. The presence of flavonoids, which reduce active catalase intermediate, Compound I to inactive Compound II have not influenced the kinetics of HOCl-induced heme modification. Possible mechanisms of the reaction of hypochlorous acid with catalase are proposed and the biological consequences are discussed.","pmid":"26116387","doi":"10.1016/j.ijbiomac.2015.06.038","url":"https://pubmed.ncbi.nlm.nih.gov/26116387/"},{"id":1588,"title":"Nitrite attenuated hypochlorous acid-mediated heme degradation in hemoglobin.","authors":"Lu, Naihao; Li, Jiayu; Ren, Xiaoming; Tian, Rong; Peng, Yi-Yuan","year":2015,"date":"2015 Aug 5","journal":"Chemico-biological interactions","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Hypochlorous acid (HOCl) is elevated in many inflammatory diseases and causes the accumulation of free iron. Through the Fenton reaction, free iron has the ability to generate free radicals and subsequently is toxic. Recent studies have demonstrated that HOCl participates in heme destruction of hemoglobin (Hb) and free iron release. In this study, it was showed that nitrite (NO2(-)) could prevent HOCl-mediated Hb heme destruction and free iron release. Also, NO2(-) prevented HOCl-mediated loss of Hb peroxidase activity. After the NO2(-)/HOCl treatment, Tyr 42 in α-chain was found to be nitrated in Hb, attenuating the electron transferring abilities of phenolic compounds. The protective effects of NO2(-) on HOCl-induced heme destruction were attributed to its reduction of ferryl Hb and/or direct scavenging of HOCl. Therefore, NO2(-) could show protective effects in some inflammatory diseases by preventing HOCl-mediated heme destruction of hemoproteins and free iron release.","pmid":"26051522","doi":"10.1016/j.cbi.2015.05.021","url":"https://pubmed.ncbi.nlm.nih.gov/26051522/"},{"id":1597,"title":"Novel mechanism for scavenging of hypochlorite involving a periplasmic methionine-rich Peptide and methionine sulfoxide reductase.","authors":"Melnyk, Ryan A; Youngblut, Matthew D; Clark, Iain C; Carlson, Hans K; Wetmore, Kelly M; Price, Morgan N; Iavarone, Anthony T; Deutschbauer, Adam M; Arkin, Adam P; Coates, John D","year":2015,"date":"2015 May 12","journal":"mBio","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Reactive chlorine species (RCS) defense mechanisms are important for bacterial fitness in diverse environments. In addition to the anthropogenic use of RCS in the form of bleach, these compounds are also produced naturally through photochemical reactions of natural organic matter and in vivo by the mammalian immune system in response to invading microorganisms. To gain insight into bacterial RCS defense mechanisms, we investigated Azospira suillum strain PS, which produces periplasmic RCS as an intermediate of perchlorate respiration. Our studies identified an RCS response involving an RCS stress-sensing sigma/anti-sigma factor system (SigF/NrsF), a soluble hypochlorite-scavenging methionine-rich periplasmic protein (MrpX), and a putative periplasmic methionine sulfoxide reductase (YedY1). We investigated the underlying mechanism by phenotypic characterization of appropriate gene deletions, chemogenomic profiling of barcoded transposon pools, transcriptome sequencing, and biochemical assessment of methionine oxidation. Our results demonstrated that SigF was specifically activated by RCS and initiated the transcription of a small regulon centering around yedY1 and mrpX. A yedY1 paralog (yedY2) was found to have a similar fitness to yedY1 despite not being regulated by SigF. Markerless deletions of yedY2 confirmed its synergy with the SigF regulon. MrpX was strongly induced and rapidly oxidized by RCS, especially hypochlorite. Our results suggest a mechanism involving hypochlorite scavenging by sacrificial oxidation of the MrpX in the periplasm. Reduced MrpX is regenerated by the YedY methionine sulfoxide reductase activity. The phylogenomic distribution of this system revealed conservation in several Proteobacteria of clinical importance, including uropathogenic Escherichia coli and Brucella spp., implying a putative role in immune response evasion in vivo. IMPORTANCE: Bacteria are often stressed in the environment by reactive chlorine species (RCS) of either anthropogenic or natural origin, but little is known of the defense mechanisms they have evolved. Using a microorganism that generates RCS internally as part of its respiratory process allowed us to uncover a novel defense mechanism based on RCS scavenging by reductive reaction with a sacrificial methionine-rich peptide and redox recycling through a methionine sulfoxide reductase. This system is conserved in a broad diversity of organisms, including some of clinical importance, invoking a possible important role in innate immune system evasion.","pmid":"25968643","doi":"10.1128/mBio.00233-15","url":"https://pubmed.ncbi.nlm.nih.gov/25968643/"},{"id":1599,"title":"Metabolic Response of Escherichia coli upon Treatment with Hypochlorite at Sub-Lethal Concentrations.","authors":"Drazic, Adrian; Kutzner, Erika; Winter, Jeannette; Eisenreich, Wolfgang","year":2015,"date":"2015","journal":"PloS one","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Hypochlorite is a reactive oxygen species that is worldwide as an antibacterial disinfectant. Hypochlorite exposure is known to cause oxidative damage to DNA and proteins. As a response to these effects, the metabolite profiles of organisms treated with sub-lethal doses of hypochlorite are assumed to be severely modified; however, the nature of these changes is hardly understood. Therefore, using nuclear magnetic resonance spectroscopy and gas chromatography-coupled mass spectrometry, we analyzed the time-dependent impact of hypochlorite exposure with a sub-lethal concentration (50 µM) on the metabolite profile of the Escherichia coli strain MG1655. Principle component analysis clearly distinguished between the metabolite profiles of bacteria treated for 0, 5, 10, 20, 40, or 60 min. Major changes in the relative amounts of fatty acids, acetic acid, and formic acid occurred within the first 5 min. Comparative gas chromatography-coupled mass spectrometry analyses revealed that the amounts of free methionine and alanine were significantly decreased in the treated cells, demonstrating their susceptibility to hypochlorite exposure. The concentrations of succinate, urea, orotic acid, 2-aminobutyric acid, and 2-hydroxybutyric acid were also severely affected, indicating general changes in the metabolic network by hypochlorite. However, most metabolite levels relaxed to the reference values of untreated cells after 40-60 min, reflecting the capability of E. coli to rapidly adapt to environmental stress factors such as the presence of sub-lethal oxidant levels.","pmid":"25932918","doi":"10.1371/journal.pone.0125823","url":"https://pubmed.ncbi.nlm.nih.gov/25932918/"},{"id":1605,"title":"Does the Transcription Factor NemR Use a Regulatory Sulfenamide Bond to Sense Bleach?","authors":"Gray, Michael Jeffrey; Li, Yan; Leichert, Lars Ingo-Ole; Xu, Zhaohui; Jakob, Ursula","year":2015,"date":"2015 Sep 20","journal":"Antioxidants & redox signaling","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Reactive chlorine species (RCS), such as hypochlorous acid (i.e., bleach), are antimicrobial oxidants produced by the innate immune system. Like many redox-regulated transcription factors, the Escherichia coli repressor NemR responds to RCS by using the reversible oxidation of highly conserved cysteines to alter its DNA-binding affinity. However, earlier work showed that RCS response in NemR does not depend on any commonly known oxidative cysteine modifications. We have now determined the crystal structure of NemR, showing that the regulatory cysteine, Cys106, is in close proximity to a highly conserved lysine (Lys175). We used crystallographic, biochemical, and mass spectrometric analyses to analyze the role of this lysine residue in RCS sensing. Based on our results, we hypothesize that RCS treatment of NemR results in the formation of a reversible Cys106-Lys175 sulfenamide bond. This is, to our knowledge, the first description of a protein whose function is regulated by a cysteine-lysine sulfenamide thiol switch, constituting a novel addition to the biological repertoire of functional redox switches.","pmid":"25867078","doi":"10.1089/ars.2015.6346","url":"https://pubmed.ncbi.nlm.nih.gov/25867078/"},{"id":1606,"title":"Oxidation by neutrophils-derived HOCl increases immunogenicity of proteins by converting them into ligands of several endocytic receptors involved in antigen uptake by dendritic cells and macrophages.","authors":"Biedroń, Rafał; Konopiński, Maciej K; Marcinkiewicz, Janusz; Józefowski, Szczepan","year":2015,"date":"2015","journal":"PloS one","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"The initiation of adaptive immune responses to protein antigens has to be preceded by their uptake by antigen presenting cells and intracellular proteolytic processing. Paradoxically, endocytic receptors involved in antigen uptake do not bind the majority of proteins, which may be the main reason why purified proteins stimulate at most weak immune responses. A shared feature of different types of adjuvants, capable of boosting immunogenicity of protein vaccines, is their ability to induce acute inflammation, characterized by early influx of activated neutrophils. Neutrophils are also rapidly recruited to sites of tissue injury or infection. These cells are the source of potent oxidants, including hypochlorous acid (HOCl), causing oxidation of proteins present in inflammatory foci. We demonstrate that oxidation of proteins by endogenous, neutrophils-derived HOCl increases their immunogenicity. Upon oxidation, different, randomly chosen simple proteins (yeast alcohol dehydrogenase, human and bovine serum albumin) and glycoproteins (human apo-transferrin, ovalbumin) gain the ability to bind with high affinity to several endocytic receptors on antigen presenting cells, which seems to be the major mechanism of their increased immunogenicity. The mannose receptor (CD206), scavenger receptors A (CD204) and CD36 were responsible for the uptake and presentation of HOCl-modified proteins by murine dendritic cells and macrophages. Other scavenger receptors, SREC-I and LOX-1, as well as RAGE were also able to bind HOCl-modified proteins, but they did not contribute significantly to these ligands uptake by dendritic cells because they were either not expressed or exhibited preference for more heavily oxidised proteins. Our results indicate that oxidation by neutrophils-derived HOCl may be a physiological mechanism of conferring immunogenicity on proteins which in their native forms do not bind to endocytic receptors. This mechanism might enable the immune system to detect infections caused by pathogens not recognized by pattern recognition receptors.","pmid":"25849867","doi":"10.1371/journal.pone.0123293","url":"https://pubmed.ncbi.nlm.nih.gov/25849867/"},{"id":1611,"title":"Chlorination of the β-triketone herbicides tembotrione and sulcotrione: Kinetic and mechanistic study, transformation products identification and toxicity.","authors":"Tawk, Alice; Deborde, Marie; Labanowski, Jérôme; Gallard, Hervé","year":2015,"date":"2015 Jun 1","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The fate of tembotrione (TBT) and sulcotrione (SCT) during chlorination was investigated in this work. Chlorination kinetics of TBT and SCT were studied by using a continuous-flow reactor in the pH range 2-12 with an excess of total chlorine. Second-order reaction was observed and rate constants of 9.69 (±0.15) × 10(3) M(-1)s(-1) for TBT and 9.48 (±0.62) × 10(3) M(-1)s(-1) for SCT were obtained at pH 7. Intrinsic rate constants for the elementary reactions of chlorine species with neutral and deprotonated forms of TBT and SCT were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the deprotonated form of the pesticide is predominant at neutral pH. Several degradation products during chlorination of TBT and SCT were identified by LC-MS/MS and a reaction pathway was proposed. Chlorine initially reacted on the α-carbon of the three carbonyl functional groups. This reaction initiated the well-known haloform reaction and produced chloroform as end-product. Molar yields of 0.99 mol CHCl3/mol and 0.91 mol CHCl3/mol were obtained for TBT and SCT, respectively at pH 7. Moreover, a toxicity evaluation using Vibrio fischeri was carried out to study the toxicity pattern during TBT and SCT chlorination. An increase in toxicity was observed but it could not be clearly assigned to the identified byproducts.","pmid":"25813488","doi":"10.1016/j.watres.2015.02.060","url":"https://pubmed.ncbi.nlm.nih.gov/25813488/"},{"id":1614,"title":"Microbial community-based polyhydroxyalkanoates (PHAs) production from wastewater: Techno-economic analysis and ex-ante environmental assessment.","authors":"Fernández-Dacosta, Cora; Posada, John A; Kleerebezem, Robbert; Cuellar, Maria C; Ramirez, Andrea","year":2015,"date":"2015 Jun","journal":"Bioresource technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"This work investigates the potential for polyhydroxybutyrate (PHB) production from wastewater, from a techno-economic and an environmental perspective, examining scale-up opportunities and bottlenecks prior to commercialisation. Conceptual process design, economic, environmental impacts and sensitivity analysis are developed for one fermentation process and three downstream processing routes, based on alkali, surfactant-hypochlorite and solvent treatments. Environmentally and cost-wise, the alkali treatment is the most favourable with production costs of 1.40€/kg PHB, global warming potential of 2.4kgCO2-eq/kg PHB and non-renewable energy use of 106MJ/kg PHB. The solvent-based process yields the highest costs and environmental burdens: 1.95€/kg PHB, 4.30kgCO2-eq/kg PHB and 156MJ/kg PHB. The production of PHB from wastewater is identified as an interesting alternative to pure culture-polyhydroxyalkanoates production from sugars. However, these results are not yet competitive with those for the petrochemical counterparts. Additional performance improvements may be possible, through process integration and optimisation.","pmid":"25796067","doi":"10.1016/j.biortech.2015.03.025","url":"https://pubmed.ncbi.nlm.nih.gov/25796067/"},{"id":1618,"title":"Methicillin-resistant Staphylococcus aureus (MRSA) contamination in bedside surfaces of a hospital ward and the potential effectiveness of enhanced disinfection with an antimicrobial polymer surfactant.","authors":"Yuen, John W M; Chung, Terence W K; Loke, Alice Y","year":2015,"date":"2015 Mar 11","journal":"International journal of environmental research and public health","category":"Materials & industrial applications","evidence":"Clinical trial","relevance":"Medium","abstract":"The aim in this study was to assess the effectiveness of a quaternary ammonium chloride (QAC) surfactant in reducing surface staphylococcal contamination in a routinely operating medical ward occupied by patients who had tested positive for methicillin-resistant Staphylococcus aureus (MRSA). The QAC being tested is an antibacterial film that is sprayed onto a surface and can remain active for up to 8 h. A field experimental study was designed with the QAC plus daily hypochlorite cleaning as the experimental group and hypochlorite cleaning alone as the control group. The method of swabbing on moistened surfaces was used for sampling. It was found that 83% and 77% of the bedside surfaces of MRSA-positive and MRSA-negative patients respectively were contaminated with staphylococci at 08:00 hours, and that the staphylococcal concentrations increased by 80% at 1200 h over a 4-hour period with routine ward and clinical activities. Irrespective of the MRSA status of the patients, high-touch surfaces around the bed-units within the studied medical ward were heavily contaminated (ranged 1 to 276 cfu/cm2 amongst the sites with positive culture) with staphylococcal bacteria including MRSA, despite the implementation of daily hypochlorite wiping. However, the contamination rate dropped significantly from 78% to 11% after the application of the QAC polymer. In the experimental group, the mean staphylococcal concentration of bedside surfaces was significantly (p<0.0001) reduced from 4.4±8.7 cfu/cm2 at 08:00 hours to 0.07±0.26 cfu/cm2 at 12:00 hours by the QAC polymer. The results of this study support the view that, in addition to hypochlorite wiping, the tested QAC surfactant is a potential environmental decontamination strategy for preventing the transmission of clinically important pathogens in medical wards.","pmid":"25768241","doi":"10.3390/ijerph120303026","url":"https://pubmed.ncbi.nlm.nih.gov/25768241/"},{"id":1620,"title":"Effect of hypochlorous acid solution on the eradication and prevention of Pseudomonas aeruginosa infection, serum biochemical variables, and cecum microbiota in rats.","authors":"Goto, Kazuo; Kuwayama, Eri; Nozu, Ryoko; Ueno, Masami; Hayashimoto, Nobuhito","year":2015,"date":"2015","journal":"Experimental animals","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"In this study, hypochlorous acid solution, a weak acid, provided as drinking water to rats, was evaluated for its ability to eradicate and prevent Pseudomonas aeruginosa infection, while monitoring its simultaneous effect on serum biochemical variables and microbiota in the rat cecum. The results suggest that the solution could not eliminate the bacteria in the experimentally infected rats; however, the administration of a 10-parts-per-million (ppm) hypochlorous acid solution as drinking water was effective in inhibiting horizontal spread of P. aeruginosa infection among cage mates. Additionally, exposure to hypochlorous solution did not have any effect on serum biochemical variables of the rat including levels of total cholesterol, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), albumin, total bilirubin, lipase, amylase, urea nitrogen, total protein, calcium (Ca), phosphorus (P), sodium (Na), chlorine (Cl), except for potassium (K) levels. The most frequently isolated bacteria in the rat cecum included species belonging to Bacteroidales, Lactobacillus, Clostridiales, Erysipelotrichaceae, Akkermansia, Coriobacteriales, and Firmicutes. The ratio of the terminal restriction fragment length polymorphism (T-RFLP) peaks did not differ across rats administered with 5 and 10 ppm weak acid solution as compared to the control group for any of the bacteria, except for Erysipelotrichaceae and Firmicutes, where the ratio of T-RFLP peaks was higher in the 5 ppm group for Erysipelotrichaceae and in the 10 ppm group for Firmicutes than that in the control group (P<0.01). The results suggest that the weak acid hypochlorous solution could not eradicate P. aeruginosa completely from rats. The solution was effective in preventing infection without affecting serum biochemical variables; however, some of bacterial microbiota may have changed due to administration of the solution.","pmid":"25736708","doi":"10.1538/expanim.14-0068","url":"https://pubmed.ncbi.nlm.nih.gov/25736708/"},{"id":1627,"title":"Imidazole catalyzes chlorination by unreactive primary chloramines.","authors":"Roemeling, Margo D; Williams, Jared; Beckman, Joseph S; Hurst, James K","year":2015,"date":"2015 May","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Hypochlorous acid and simple chloramines (RNHCl) are stable biologically derived chlorinating agents. In general, the chlorination potential of HOCl is much greater than that of RNHCl, allowing it to oxidize or chlorinate a much wider variety of reaction partners. However, in this study we demonstrate by kinetic analysis that the reactivity of RNHCl can be dramatically promoted by imidazole and histidyl model compounds via intermediary formation of the corresponding imidazole chloramines. Two biologically relevant reactions were investigated--loss of imidazole-catalyzed chlorinating capacity and phenolic ring chlorination using fluorescein and the tyrosine analog, 4-hydroxyphenylacetic acid (HPA). HOCl reacted stoichiometrically with imidazole, N-acetylhistidine (NAH), or imidazoleacetic acid to generate the corresponding imidazole chloramines which subsequently decomposed. Chloramine (NH2Cl) also underwent a markedly accelerated loss in chlorinating capacity when NAH was present, although in this case N-α-acetylhistidine chloramine (NAHCl) did not accumulate, indicating that the catalytic intermediate must be highly reactive. Mixing HOCl with 1-methylimidazole (MeIm) led to very rapid loss in chlorinating capacity via formation of a highly reactive chlorinium ion (MeImCl(+)) intermediate; this behavior suggests that the reactive forms of the analogous imidazole chloramines are their conjugate acids, e.g., the imidazolechlorinium ion (HImCl(+)). HOCl-generated imidazole chloramine (ImCl) reacted rapidly with fluorescein in a specific acid-catalyzed second-order reaction to give 3'-monochloro and 3',5'-dichloro products. Equilibrium constants for the transchlorination reactions HOCl + HIm = H2O + ImCl and NH2Cl + HIm = NH3 + ImCl were estimated from the dependence of the rate constants on [HIm]/[HOCl] and literature data. Acid catalysis again suggests that the actual chlorinating agent is HImCl(+); consistent with this interpretation, MeIm markedly catalyzed fluorescein chlorination by HOCl. Time-dependent imidazole-catalyzed HPA chlorination by NH2Cl was also demonstrated by product analyses. Quantitative assessment of the data suggests that physiological levels of histidyl groups will react with primary chloramines to generate a flux of imidazole chloramine sufficient to catalyze biological chlorination via HImCl(+), particularly in environments that generate high concentrations of HOCl such as the neutrophil phagosome.","pmid":"25660996","doi":"10.1016/j.freeradbiomed.2015.01.026","url":"https://pubmed.ncbi.nlm.nih.gov/25660996/"},{"id":1630,"title":"Hypohalous acids contribute to renal extracellular matrix damage in experimental diabetes.","authors":"Brown, Kyle L; Darris, Carl; Rose, Kristie Lindsey; Sanchez, Otto A; Madu, Hartman; Avance, Josh; Brooks, Nickolas; Zhang, Ming-Zhi; Fogo, Agnes; Harris, Raymond; Hudson, Billy G; Voziyan, Paul","year":2015,"date":"2015 Jun","journal":"Diabetes","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"In diabetes, toxic oxidative pathways are triggered by persistent hyperglycemia and contribute to diabetes complications. A major proposed pathogenic mechanism is the accumulation of protein modifications that are called advanced glycation end products. However, other nonenzymatic post-translational modifications may also contribute to pathogenic protein damage in diabetes. We demonstrate that hypohalous acid-derived modifications of renal tissues and extracellular matrix (ECM) proteins are significantly elevated in experimental diabetic nephropathy. Moreover, diabetic renal ECM shows diminished binding of α1β1 integrin consistent with the modification of collagen IV by hypochlorous (HOCl) and hypobromous acids. Noncollagenous (NC1) hexamers, key connection modules of collagen IV networks, are modified via oxidation and chlorination of tryptophan and bromination of tyrosine residues. Chlorotryptophan, a relatively minor modification, has not been previously found in proteins. In the NC1 hexamers isolated from diabetic kidneys, levels of HOCl-derived oxidized and chlorinated tryptophan residues W(28) and W(192) are significantly elevated compared with nondiabetic controls. Molecular dynamics simulations predicted a more relaxed NC1 hexamer tertiary structure and diminished assembly competence in diabetes; this was confirmed using limited proteolysis and denaturation/refolding. Our results suggest that hypohalous acid-derived modifications of renal ECM, and specifically collagen IV networks, contribute to functional protein damage in diabetes.","pmid":"25605804","doi":"10.2337/db14-1001","url":"https://pubmed.ncbi.nlm.nih.gov/25605804/"},{"id":1633,"title":"Inflaming the diseased brain: a role for tainted melanins.","authors":"Jeitner, T M; Kalogiannis, M; Patrick, P A; Gomolin, I; Palaia, T; Ragolia, L; Brand, D; Delikatny, E J","year":2015,"date":"2015 May","journal":"Biochimica et biophysica acta","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Inflammation plays a crucial role in neurodegenerative diseases, but the irritants responsible for this response remain largely unknown. This report addressed the hypothesis that hypochlorous acid reacts with dopamine to produce melanic precipitates that promote cerebral inflammation. Spectrophotometric studies demonstrated that nM amounts of HOCl and dopamine react within seconds. A second-order rate constant for the reaction of HOCl and dopamine of 2.5 × 10(4)M(-1)s(-1) was obtained by measuring loss of dopaminergic fluorescence due to HOCl. Gravimetric measurements, electron microscopy, elemental analysis, and a novel use of flow cytometry confirmed that the major product of this reaction is a precipitate with an average diameter of 1.5 μm. Flow cytometry was also used to demonstrate the preferential reaction of HOCl with dopamine rather than albumin. Engulfment of the chlorodopamine particulates by phagocytes in vitro caused these cells to release TNFα and die. Intrastriatal administration of 10(6) particles also increased the content of TNFα in the brain and led to a 50% loss of the dopaminergic neurons in the nigra. These studies indicate that HOCl and dopamine react quickly and preferentially with each other to produce particles that promote inflammation and neuronal death in the brain.","pmid":"25585261","doi":"10.1016/j.bbadis.2015.01.004","url":"https://pubmed.ncbi.nlm.nih.gov/25585261/"},{"id":1634,"title":"Human native, enzymatically modified and oxidized low density lipoproteins show different lipidomic pattern.","authors":"Orsó, Evelyn; Matysik, Silke; Grandl, Margot; Liebisch, Gerhard; Schmitz, Gerd","year":2015,"date":"2015 Mar","journal":"Biochimica et biophysica acta","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"In the present paper we have performed comparative lipidomic analysis of two prototypic atherogenic LDL modifications, oxidized LDL and enzymatically modified LDL. Oxidization of LDL was carried out with different chemical modifications starting from the same native LDL preparations: (i) by copper oxidation leading to terminally oxidized LDL (oxLDL), (ii) by moderate oxidization with HOCl (HOCl LDL), (iii) by long term storage of LDL at 4°C to produce minimally modified LDL (mmLDL), or (iv) by 15-lipoxygenase, produced by a transfected fibroblast cell line (LipoxLDL). The enzymatic modification of LDL was performed by treatment of native LDL with trypsin and cholesteryl esterase (eLDL). Free cholesterol (FC) and cholesteryl esters (CE) represent the predominant lipid classes in all LDL preparations. In contrast to native LDL, which contains about two-thirds of total cholesterol as CE, enzymatic modification of LDL decreased the proportion of CE to about one-third. Free cholesterol and CE in oxLDL are reduced by their conversion to oxysterols. Oxidization of LDL preferentially influences the content of polyunsaturated phosphatidylcholine (PC) and polyunsaturated plasmalogen species, by reducing the total PC fraction in oxLDL. Concomitantly, a strong rise of the lysophosphatidylcholine (LPC) fraction can be found in oxLDL as compared to native LDL. This effect is less pronounced in eLDL. The mild oxidation of LDL with hypochlorite and/or lipoxygenase does not alter the content of the analyzed lipid classes and species in a significant manner. The lipidomic characterization of modified LDLs contributes to the better understanding their diverse cellular effects.","pmid":"25583048","doi":"10.1016/j.bbalip.2015.01.001","url":"https://pubmed.ncbi.nlm.nih.gov/25583048/"},{"id":1635,"title":"The effects of hypochlorous acid and neutrophil proteases on the structure and function of extracellular superoxide dismutase.","authors":"Morales, Karla; Olesen, Mads Nikolaj; Poulsen, Ebbe Toftgaard; Larsen, Ulrike G; Enghild, Jan J; Petersen, Steen Vang","year":2015,"date":"2015 Apr","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Extracellular superoxide dismutase (EC-SOD) is expressed by both macrophages and neutrophils and is known to influence the inflammatory response. Upon activation, neutrophils generate hypochlorous acid (HOCl) and secrete proteases to combat invading microorganisms. This produces a hostile environment in which enzymatic activity in general is challenged. In this study, we show that EC-SOD exposed to physiologically relevant concentrations of HOCl remains enzymatically active and retains the heparin-binding capacity, although HOCl exposure established oxidative modification of the N-terminal region (Met32) and the formation of an intermolecular cross-link in a fraction of the molecules. The cross-linking was also induced by activated neutrophils. Moreover, we show that the neutrophil-derived proteases human neutrophil elastase and cathepsin G cleaved the N-terminal region of EC-SOD irrespective of HOCl oxidation. Although the cleavage by elastase did not affect the quaternary structure, the cleavage by cathepsin G dissociated the molecule to produce EC-SOD monomers. The present data suggest that EC-SOD is stable and active at the site of inflammation and that neutrophils have the capacity to modulate the biodistribution of the protein by generating EC-SOD monomers that can diffuse into tissue.","pmid":"25582887","doi":"10.1016/j.freeradbiomed.2014.12.027","url":"https://pubmed.ncbi.nlm.nih.gov/25582887/"},{"id":1637,"title":"Postantifungal-like effect of sublethal treatment of Candida albicans with acid-electrolyzed water.","authors":"Mokudai, Takayuki; Kanno, Taro; Niwano, Yoshimi","year":2015,"date":"2015 Mar","journal":"Archives of oral biology","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"OBJECTIVE: Acid-electrolyzed water (AEW) has been applied to the treatment of oral candidiasis. We evaluated the postantifungal effect (PAFE)-like activity of AEW against Candida albicans under sublethal conditions by exposing C. albicans to dilute AEW. DESIGN: The growth of C. albicans after a short-term exposure to dilute AEW was evaluated in broth and on agar culture. The involvement of reactive oxygen species (ROS) in the PAFE was examined by flow cytometric analysis with hydroxyphenyl fluorescein (HPF) as a fluorescence probe. RESULTS: The dilute AEW exerted PAFE-like activity against C. albicans. ROS were produced in the cells treated with AEW diluted 16 times or fewer. The increase in HPF fluorescence after treatment with dilute AEW was cancelled by dimethyl sulfoxide, a hydroxyl radical (OH) scavenger. CONCLUSION: It would be expected that the ROS, especially OH, produced in the C. albicans cells treated with sublethal dilutions of AEW could exert PAFE-like activity against the fungal cells.","pmid":"25555249","doi":"10.1016/j.archoralbio.2014.12.008","url":"https://pubmed.ncbi.nlm.nih.gov/25555249/"},{"id":1639,"title":"Activation of RidA chaperone function by N-chlorination.","authors":"Müller, Alexandra; Langklotz, Sina; Lupilova, Nataliya; Kuhlmann, Katja; Bandow, Julia Elisabeth; Leichert, Lars Ingo Ole","year":2014,"date":"2014 Dec 17","journal":"Nature communications","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Escherichia coli RidA is a member of a structurally conserved, yet functionally highly diverse protein family involved in translation inhibition (human), Hsp90-like chaperone activity (fruit fly) and enamine/imine deamination (Salmonella enterica). Here, we show that E. coli RidA modified with HOCl acts as a highly effective chaperone. Although activation of RidA is reversed by treatment with DTT, ascorbic acid, the thioredoxin system and glutathione, it is independent of cysteine modification. Instead, treatment with HOCl or chloramines decreases the amino group content of RidA by reversibly N-chlorinating positively charged residues. N-chlorination increases hydrophobicity of RidA and promotes binding to a wide spectrum of unfolded cytosolic proteins. Deletion of ridA results in an HOCl-sensitive phenotype. HOCl-mediated N-chlorination thus is a cysteine-independent post-translational modification that reversibly turns RidA into an effective chaperone holdase, which plays a crucial role in the protection of cytosolic proteins during oxidative stress.","pmid":"25517874","doi":"10.1038/ncomms6804","url":"https://pubmed.ncbi.nlm.nih.gov/25517874/"},{"id":1641,"title":"Microbicidal activity of neutrophils is inhibited by isolates from recurrent vaginal candidiasis (RVVC) caused by Candida albicans through fungal thioredoxin reductase.","authors":"Ratti, Bianca Altrão; Godoy, Janine Silva Ribeiro; de Souza Bonfim Mendonça, Patrícia; Bidóia, Danielle Lazarin; Nakamura, Tânia Ueda; Nakamura, Celso Vataru; Lopes Consolaro, Marcia Edilaine; Estivalet Svidzinski, Terezinha Inez; de Oliveira Silva, Sueli","year":2015,"date":"2015 Jan","journal":"Cellular immunology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Vulvovaginal candidiasis (VVC) is characterized by an infection of the vulva and vagina, mainly caused by Candida albicans, a commensal microorganism that inhabits the vaginal, digestive, and respiratory mucosae. Vulvovaginal candidiasis affects approximately 75% of women, and 5% develop the recurrent form (RVVC). The aim of the present study was to evaluate whether neutrophils microbicidal response is triggered when activated with RVVC isolates caused by C. albicans. Our results showed that RVVC isolates induced neutrophil migration but significantly decrease the microbicidal activity of neutrophils, compared with VVC and ASS isolates. The microbicidal activity of neutrophils is highly dependent on the production of reactive oxygen species/reactive nitrogen species (ROS/RNS). However, this isolate induced detoxification of ROS/RNS produced by neutrophils, reflected by the high level of thiol groups and by the oxygen consumption. Therefore, RVVC isolates induced biochemical changes in the inflammatory response triggered by neutrophils, and these effects were mainly related to the detoxification of ROS/RNS through the thioredoxin reductase (TR), a key antioxidant enzyme in fungi. This might be one of the resistance mechanisms triggered by RVVC caused by C. albicans.","pmid":"25497972","doi":"10.1016/j.cellimm.2014.11.004","url":"https://pubmed.ncbi.nlm.nih.gov/25497972/"},{"id":1643,"title":"Inactivation of chemical and heat-resistant spores of Bacillus and Geobacillus by nitrogen cold atmospheric plasma evokes distinct changes in morphology and integrity of spores.","authors":"van Bokhorst-van de Veen, Hermien; Xie, Houyu; Esveld, Erik; Abee, Tjakko; Mastwijk, Hennie; Nierop Groot, Masja","year":2015,"date":"2015 Feb","journal":"Food microbiology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Bacterial spores are resistant to severe conditions and form a challenge to eradicate from food or food packaging material. Cold atmospheric plasma (CAP) treatment is receiving more attention as potential sterilization method at relatively mild conditions but the exact mechanism of inactivation is still not fully understood. In this study, the biocidal effect by nitrogen CAP was determined for chemical (hypochlorite and hydrogen peroxide), physical (UV) and heat-resistant spores. The three different sporeformers used are Bacillus cereus a food-borne pathogen, and Bacillus atrophaeus and Geobacillus stearothermophilus that are used as biological indicators for validation of chemical sterilization and thermal processes, respectively. The different spores showed variation in their degree of inactivation by applied heat, hypochlorite, hydrogen peroxide, and UV treatments, whereas similar inactivation results were obtained with the different spores treated with nitrogen CAP. G. stearothermophilus spores displayed high resistance to heat, hypochlorite, hydrogen peroxide, while for UV treatment B. atrophaeus spores are most tolerant. Scanning electron microscopy analysis revealed distinct morphological changes for nitrogen CAP-treated B. cereus spores including etching effects and the appearance of rough spore surfaces, whereas morphology of spores treated with heat or disinfectants showed no such changes. Moreover, microscopy analysis revealed CAP-exposed B. cereus spores to turn phase grey conceivably because of water influx indicating damage of the spores, a phenomenon that was not observed for non-treated spores. In addition, data are supplied that exclude UV radiation as determinant of antimicrobial activity of nitrogen CAP. Overall, this study shows that nitrogen CAP treatment has a biocidal effect on selected Bacillus and Geobacillus spores associated with alterations in spore surface morphology and loss of spore integrity.","pmid":"25481059","doi":"10.1016/j.fm.2014.03.018","url":"https://pubmed.ncbi.nlm.nih.gov/25481059/"},{"id":1647,"title":"Evaluation of sprayed hypochlorous acid solutions for their virucidal activity against avian influenza virus through in vitro experiments.","authors":"Hakim, Hakimullah; Thammakarn, Chanathip; Suguro, Atsushi; Ishida, Yuki; Kawamura, Akinobu; Tamura, Miho; Satoh, Keisuke; Tsujimura, Misato; Hasegawa, Tomomi; Takehara, Kazuaki","year":2015,"date":"2015 Feb","journal":"The Journal of veterinary medical science","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCl) solutions were evaluated for their virucidal ability against a low pathogenic avian influenza virus (AIV), H7N1. HOCl solutions containing 50, 100 and 200 ppm chlorine (pH 6) or their sprayed solutions (harvested in dishes placed at 1 or 30 cm distance between the spray nozzle and dish) were mixed with the virus with or without organic materials (5% fetal bovine serum: FBS). Under plain diluent conditions (without FBS), harvested solutions of HOCl after spraying could decrease the AIV titer by more than 1,000 times, to an undetectable level (< 2.5 log10TCID50/ml) within 5 sec, with the exception of the 50 ppm solution harvested after spraying at the distance of 30 cm. Under the dirty conditions (in the presence of 5% FBS), they lost their virucidal activity. When HOCl solutions were sprayed directly on the virus on rayon sheets for 10 sec, the solutions of 100 and 200 ppm could inactivate AIV immediately after spraying, while 50 ppm solution required at least 3 min of contact time. In the indirect spray form, after 10 sec of spraying, the lids of the dishes were opened to expose the virus on rayon sheets to HOCl. In this form, the 200 ppm solution inactivated AIV within 10 min of contact, while 50 and 100 ppm could not inactivate it. These data suggest that HOCl can be used in spray form to inactivate AIV at the farm level.","pmid":"25421399","doi":"10.1292/jvms.14-0413","url":"https://pubmed.ncbi.nlm.nih.gov/25421399/"},{"id":1650,"title":"Optimization of microwave-assisted extraction of polyphenols from herbal teas and evaluation of their in vitro hypochlorous acid scavenging activity.","authors":"Bekdeşer, Burcu; Durusoy, Nazan; Özyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat","year":2014,"date":"2014 Nov 19","journal":"Journal of agricultural and food chemistry","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCl) is an important reactive oxygen species (ROS) and non-radical and is taking part in physiological processes concerned with the defense of the organism, but there has been limited information regarding its scavenging by polyphenols. This study was designed to examine the HOCl scavenging activity of several polyphenols and microwave-assisted extracts of herbal teas. HOCl scavenging activity has usually been determined spectrophotometrically by a KI/taurine assay at 350 nm. Because some polyphenols (i.e., apigenin and chrysin) have a strong ultraviolet (UV) absorption in this range, their HOCl scavenging activity was alternatively determined without interference using resorcinol (1,3-dihydroxybenzene) as a fluorogenic probe. In the present assay, HOCl induces the chlorination of resorcinol into its non-fluorescent products. Polyphenols as HOCl scavengers inhibit the chlorination of the probe by this species. Thus, the 25% inhibitive concentration (IC25) value of polyphenols was determined using the relative increase in fluorescence intensity of the resorcinol probe. The HOCl scavenging activities of the test compounds decreased in the order: epigallocatechin gallate > quercetin > gallic acid > rutin > catechin > kaempferol. The present study revealed that epigallocatechin gallate (IC25 = 0.1 μM) was the most effective scavenging agent. In addition to polyphenols, four herbal teas were evaluated for their HOCl activity using the resorcinol method. The proposed spectrofluorometric method was practical, rapid, and less open to interferences by absorbing substances in the range of 200-420 nm. The results hint to the possibility of polyphenols having beneficial effects in diseases, such as atherosclerosis, in which HOCl plays a pathogenic role.","pmid":"25365495","doi":"10.1021/jf503065h","url":"https://pubmed.ncbi.nlm.nih.gov/25365495/"},{"id":1658,"title":"Protein chlorination in neutrophil phagosomes and correlation with bacterial killing.","authors":"Green, Jessie N; Kettle, Anthony J; Winterbourn, Christine C","year":2014,"date":"2014 Dec","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Neutrophils ingest and kill bacteria within phagocytic vacuoles. We investigated where they produce hypochlorous acid (HOCl) following phagocytosis by measuring conversion of protein tyrosine residues to 3-chlorotyrosine. We also examined how varying chloride availability affects the relationship between HOCl formation in the phagosome and bacterial killing. Phagosomal proteins, isolated following ingestion of opsonized magnetic beads, contained 11.4 Cl-Tyr per thousand tyrosine residues. This was 12 times higher than the level in proteins from the rest of the neutrophil and ~6 times higher than previously recorded for protein from ingested bacteria. These results indicate that HOCl production is largely localized to the phagosomes and a substantial proportion reacts with phagosomal protein before reaching the microbe. This will in part detoxify the oxidant but should also form chloramines which could contribute to the killing mechanism. Neutrophils were either suspended in chloride-free gluconate buffer or pretreated with formyl-Met-Leu-Phe, a procedure that has been reported to deplete intracellular chloride. These treatments, alone or in combination, decreased both chlorination in phagosomes and killing of Staphylococcus aureus by up to 50%. There was a strong positive correlation between the two effects. Killing was predominantly oxidant and myeloperoxidase dependent (88% inhibition by diphenylene iodonium and 78% by azide). These results imply that lowering the chloride concentration limits HOCl production and oxidative killing. They support a role for HOCl generation, rather than an alternative myeloperoxidase activity, in the killing process.","pmid":"25236747","doi":"10.1016/j.freeradbiomed.2014.08.013","url":"https://pubmed.ncbi.nlm.nih.gov/25236747/"},{"id":1659,"title":"Clinically relevant HOCl concentrations reduce clot retraction rate via the inhibition of energy production in platelet mitochondria.","authors":"Misztal, T; Rusak, T; Tomasiak, M","year":2014,"date":"2014 Dec","journal":"Free radical research","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Using porcine blood, we examined the impact of hypochlorite, product of activated inflammatory cells, on clot retraction (CR), an important step of hemostasis. We found that, in vitro, HOCl is able to reduce CR rate and enlarge final clot size in whole blood (t.c. 100 μM), platelet-rich plasma (PRP) threshold concentration (t.c. 50 μM), and an artificial system (washed platelets and fibrinogen) (t.c. 25 nM). Combination of low HOCl and peroxynitrite concentrations resulted in synergistic inhibition of CR by these stressors. Concentrations of HOCl completely inhibiting CR failed to affect the kinetics of coagulation measured in PRP and in platelet-free plasma. Concentrations of HOCl reducing CR rate in PRP augmented production of lactate, inhibited consumption of oxygen by platelets, and decreased total adenosine triphosphate (ATP) content in PRP-derived clots. In an artificial system, concentrations of HOCl resulting in inhibition of CR (25-100 nM) reduced mitochondrial transmembrane potential and did not affect actin polymerization in thrombin-stimulated platelets. These concentrations of HOCl failed to affect the adhesion of washed platelets to fibrinogen and to evoke sustained calcium signal, thus excluding stressor action on glycoprotein IIb/IIIa receptors. Exogenously added Mg-ATP almost completely recovered HOCl-mediated retardation of CR. Concentrations of HOCl higher than those affecting CR reduced thromboelastometric variables (maximum clot firmness and α angle). We conclude that low clinically relevant HOCl concentrations may evoke the inhibition of CR via the reduction of platelet contractility resulted from malfunction of platelet mitochondria. At the inflammatory conditions, CR may be the predominant HOCl target.","pmid":"25236568","doi":"10.3109/10715762.2014.960866","url":"https://pubmed.ncbi.nlm.nih.gov/25236568/"},{"id":1663,"title":"Antibacterial validation of electrogenerated hypochlorite using carbon-based electrodes.","authors":"Locker, J; Fitzgerald, P; Sharp, D","year":2014,"date":"2014 Dec","journal":"Letters in applied microbiology","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"This proof-of-concept study explores the novel use of carbon-based electrodes for the electrochemical generation of hypochlorite and compares the antimicrobial efficacy against commercial hypochlorite solution. Antimicrobial concentrations of hypochlorite were generated using pad-printed carbon and carbon fibre electrodes, yielding up to 0·027% hypochlorite in 60 min and 0·1% hypochlorite in 15 min, respectively, in a nondivided assembly. The minimum inhibitory concentration (MIC) of the electrogenerated hypochlorite produced using carbon fibre electrodes was established for four medically important bacteria (Pseudomonas aeruginosa and Staphylococcus aureus approx. 0·025%, Escherichia coli and Enterococcus faecalis approx. 0·012%) and found to be in agreement with those determined using commercial hypochlorite solution. Therefore, carbon-based electrodes, particularly carbon fibre, have proven effective for the generation of antimicrobial concentrations of hypochlorite. The similarity of the MIC values to commercial hypochlorite solutions suggests that the antimicrobial efficacy is derived from the quantified hypochlorite generated and not due to marked cogeneration of reactive oxygen species, as identified for other assemblies. As such, the application of carbon electrodes may be suitable for the local production of hypochlorite for healthcare antisepsis. SIGNIFICANCE AND IMPACT OF THE STUDY: Carbon fibre electrodes can rapidly generate antimicrobial concentrations of hypochlorite; as such, these cheap and commercially available electrodes are proposed for the local production of hypochlorite for healthcare antisepsis. Importantly, the antimicrobial properties of the electrochemically generated hypochlorite mirror those of commercial hypochlorite, suggesting this is not enhanced by the cogeneration of reactive oxygen species. This illustrates the potential use of disposable carbon electrodes for localized small-volume production of hypochlorite for surface and skin cleansing, and opens a broader scope of research into the exploitation of carbon electrodes for this application.","pmid":"25179583","doi":"10.1111/lam.12324","url":"https://pubmed.ncbi.nlm.nih.gov/25179583/"},{"id":1667,"title":"Kinetics of 3-nitrotyrosine modification on exposure to hypochlorous acid.","authors":"Curtis, M P; Neidigh, J W","year":2014,"date":"2014 Nov","journal":"Free radical research","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The markers 3-nitrotyrosine and 3-chlorotyrosine are measured as surrogates for reactive nitrogen species and hypochlorous acid respectively, which are both elevated in inflamed human tissues. Previous studies reported a loss of 3-nitrotyrosine when exposed to hypochlorous acid, suggesting that observations of 3-nitrotyrosine underestimate the presence of reactive nitrogen species in diseased tissue (Whiteman and Halliwell, Biochemical and Biophysical Research Communications, 258, 168-172 (1999)). This report evaluates the significance of 3-nitrotyrosine loss by measuring the kinetics of the reaction between 3-nitrotyrosine and hypochlorous acid. The results demonstrate that 3-nitrotyrosine is chlorinated by hypochlorous acid or chloramines to form 3-chloro-5-nitrotyrosine. As 3-nitrotyrosine from in vivo samples is usually found within proteins rather than as free amino acid, we also examined the reaction of 3-nitrotyrosine modification in the context of peptides. The chlorination of 3-nitrotyrosine in peptides was observed to occur up to 700-fold faster than control reactions using equivalent amino acid mixtures. These results further advance our understanding of tyrosine chlorination and the use of 3-nitrotyrosine formed in vivo as a biomarker of reactive nitrogen species.","pmid":"25119650","doi":"10.3109/10715762.2014.954110","url":"https://pubmed.ncbi.nlm.nih.gov/25119650/"},{"id":1669,"title":"The use of hypochlorous acid as a model for investigating bladder overactivity.","authors":"Dambros, Miriam; Dambros, Mara Celia; Lorenzetti, Fabio; Dassen, E L H M; van Koeveringe, G A","year":2014,"date":"2014 May-Jun","journal":"International braz j urol : official journal of the Brazilian Society of Urology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Involuntary detrusor contractions play an important role in the development of urge incontinence. Also in an in-vitro situation contractions which develop spontaneously can be seen; a parallel with the in vivo observations is likely. In order to study this muscle overactivity we investigated the possibility to induce this phenomenon with oxidative stress using hypochlorous acid (HOCl). MATERIALS AND METHODS: Urinary bladder muscle strips from pigs were mounted in a custom made organ bath and incubated for 20 minutes in Krebs solution. Next HOCl (10 µM) was added to the organ bath and the onset of overactive contractions was closely followed. Overactivity was defined as a development of more than 5 phasic detrusor contractions per minute without any other provocation in the 30 minutes following addition of HOCl to the organ bath. RESULTS: Of the 50 strips which were used 36 (72%) became overactive after exposure to HOCl during 30 minutes recording. In 76% of the overactive strips overactivity occurred within 5 minutes, in 19% between 5 and 15 minutes, and in 5% it took longer than 15 minutes. The overactivity could be stopped by washing out HOCl for 10 minutes after which still a significant contraction after EFS and ACh stimulation was seen. CONCLUSIONS: It can be concluded that an oxidative stressor, like HOCl, is capable of inducing smooth muscle overactivity. This model can be used for the development and testing of new treatment modalities for the overactive detrusor. Furthermore, this study provides evidence for a causal relationship between oxidative stress and detrusor overactivity.","pmid":"25010308","doi":"10.1590/S1677-5538.IBJU.2014.03.16","url":"https://pubmed.ncbi.nlm.nih.gov/25010308/"},{"id":1671,"title":"Influence of sanitizers on the lipopolysaccharide toxicity of Escherichia coli strains cultivated in the presence of Zygosaccharomyces bailii.","authors":"Mogotsi, Lerato; De Smidt, Olga; Venter, Pierre; Groenewald, Willem","year":2014,"date":"2014","journal":"TheScientificWorldJournal","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The influence of sublethal concentrations of two sanitizers, liquid iodophor and liquid hypochlorite (LH), on the growth rates and toxicity of food-borne pathogenic Escherichia coli strains grown in the presence of spoilage yeast Zygosaccharomyces bailii was assessed. When grown in combination with Z. bailii both E. coli O113 and E. coli O26 exhibited slower growth rates, except when E. coli O113 was grown in combination with Z. bailii at 0.2% LH. The growth rate of Z. bailii was not impacted by the addition of the sanitizers or by communal growth with E. coli strains. LAL and IL-6 results indicated a decrease in toxicity of pure E. coli cultures with comparable profiles for control and sanitizer exposed samples, although the LAL assay proved to be more sensitive. Interestingly, pure cultures of Z. bailii showed increased toxicity measured by LAL and decreased toxicity measured by IL-6. LAL analysis showed a decrease in toxicity of both E. coli strains grown in combination with Z. bailii, while IL-6 analysis of the mixed cultures showed an increase in toxicity. The use of LAL for toxicity determination in a mixed culture overlooks the contribution made by spoilage yeast, thus demonstrating the importance of using the appropriate method for toxicity testing in mixed microbe environments.","pmid":"24977173","doi":"10.1155/2014/135856","url":"https://pubmed.ncbi.nlm.nih.gov/24977173/"},{"id":1675,"title":"Superior bactericidal activity of N-bromine compounds compared to their N-chlorine analogues can be reversed under protein load.","authors":"Gottardi, W; Klotz, S; Nagl, M","year":2014,"date":"2014 Jun","journal":"Journal of applied microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"AIMS: To investigate and compare the bactericidal activity (BA) of active bromine and chlorine compounds in the absence and presence of protein load. METHODS AND RESULTS: Quantitative killing tests against Escherichia coli and Staphylococcus aureus were performed both in the absence and in the presence of peptone with pairs of isosteric active chlorine and bromine compounds: hypochlorous and hypobromous acid (HOCl and HOBr), dichloro- and dibromoisocyanuric acid, chlorantine and bromantine (1,3-dibromo- and 1,3 dichloro-5,5-dimethylhydantoine), chloramine T and bromamine T (N-chloro- and N-bromo-4-methylbenzenesulphonamide sodium), and N-chloro- and N-bromotaurine sodium. To classify the bactericidal activities on a quantitative basis, an empirical coefficient named specific bactericidal activity (SBA), founded on the parameters of killing curves, was defined: SBA= mean log reductions/(mean exposure times x concentration) [mmol 1(-1) min (-1)]. In the absence of peptone, tests with washed micro-organisms revealed a throughout higher BA of bromine compounds with only slight differences between single substances. This was in contrast to chlorine compounds, whose killing times differed by a factor of more than four decimal powers. As a consequence, also the isosteric pairs showed according differences. In the presence of peptone, however, bromine compounds showed an increased loss of BA, which partly caused a reversal of efficacy within isosteric pairs. CONCLUSIONS: In medical practice, weakly oxidizing active chlorine compounds like chloramines have the highest potential as topical anti-infectives in the presence of proteinaceous material (mucous membranes, open wounds). Active bromine compounds, on the other hand, have their chance at insensitive body regions with low organic matter, for example skin surfaces. SIGNIFICANCE AND IMPACT OF THE STUDY: The expected protein load is one of the most important parameters for selection of a suited active halogen compound.","pmid":"24905215","doi":"10.1111/jam.12474","url":"https://pubmed.ncbi.nlm.nih.gov/24905215/"},{"id":1681,"title":"Five-year longitudinal assessment (2008 to 2012) of E-101 solution activity against clinical target and antimicrobial-resistant pathogens.","authors":"Denys, Gerald A; Pillar, Chris M; Sahm, Daniel F; O'Hanley, Peter; Stephens, Jackson T Jr","year":2014,"date":"2014 Aug","journal":"Antimicrobial agents and chemotherapy","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"This study summarizes the topical E-101 solution susceptibility testing results for 760 Gram-positive and Gram-negative target pathogens collected from 75 U.S. sites between 2008 and 2012 and 103 ESKAPE pathogens. E-101 solution maintained potent activity against all bacterial species studied for each year tested, with MICs ranging from <0.008 to 0.25 μg porcine myeloperoxidase (pMPO)/ml. These results confirm that E-101 solution retains its potent broad-spectrum activity against U.S. clinical isolates and organisms with challenging resistance phenotypes.","pmid":"24841272","doi":"10.1128/AAC.03020-14","url":"https://pubmed.ncbi.nlm.nih.gov/24841272/"},{"id":1683,"title":"Nanomolar detection of hypochlorite by a rhodamine-based chiral hydrazide in absolute aqueous media: application in tap water analysis with live-cell imaging.","authors":"Goswami, Shyamaprosad; Das, Avijit Kumar; Manna, Abhishek; Maity, Anup Kumar; Saha, Partha; Quah, Ching Kheng; Fun, Hoong-Kun; Abdel-Aziz, Hatem A","year":2014,"date":"2014 Jul 1","journal":"Analytical chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"By employing the oxidation property of hypochlorite (OCl(-)), a novel rhodamine-based hydrazide of the chiral acid ((S)-(-)-2-pyrrolidone-5-carboxylic acid) (RHHP) was designed and synthesized for detection of OCl(-) absolutely in aqueous medium at nanomolar level. The structure of the chiral sensor was also proved by the X-ray crystallography. The bioactivity and the application of the probe for detection of OCl(-) in natural water system have been demonstrated. A plausible mechanism for oxidation of the sensor followed by hydrolysis is also proposed. The sensibility of the receptor toward OCl(-) was studied in absolute aqueous media, and the detection limit of hypochlorite-mediated oxidation to the receptor in nanomolar level makes this platform (RHHP) an ultrasensitive and unique system for OCl(-) oxidation.","pmid":"24806145","doi":"10.1021/ac500418k","url":"https://pubmed.ncbi.nlm.nih.gov/24806145/"},{"id":1689,"title":"Effects of indoor swimming pools on the nasal cytology of pool workers.","authors":"Erkul, E; Yaz, A; Cıngı, C; İnançli, H M; San, T; Bal, C","year":2014,"date":"2014 May","journal":"The Journal of laryngology and otology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"OBJECTIVE: We aimed to evaluate the relationship between swimming pool pollutants and allergic rhinitis in swimming pool workers. MATERIALS AND METHODS: Twenty-seven indoor pool workers (group 1) and 49 control subjects (group 2) were enrolled in the study. A skin prick test was performed and a nasal smear was obtained from each subject to evaluate rhinitis. RESULTS: When the groups were compared in terms of epithelial cells, group 1 had significantly more epithelial cells than group 2. When the groups were compared with regard to eosinophils, group 1 had significantly more eosinophils than group 2. The skin prick test results for both groups were not significantly different. CONCLUSION: Indoor pool workers showed severe symptoms of rhinitis and eosinophilic nasal cytology, likely due to chlorine. Nasal cytology is an easy-to-administer diagnostic test and can be used to follow up rhinitis in indoor pool workers, along with nasal endoscopy, a detailed clinical history and a skin prick test.","pmid":"24762781","doi":"10.1017/S0022215114000784","url":"https://pubmed.ncbi.nlm.nih.gov/24762781/"},{"id":1691,"title":"Development of a functional ruthenium(II) complex for probing hypochlorous acid in living cells.","authors":"Ye, Zhiqiang; Zhang, Run; Song, Bo; Dai, Zhichao; Jin, Dayong; Goldys, Ewa M; Yuan, Jingli","year":2014,"date":"2014 Jun 14","journal":"Dalton transactions (Cambridge, England : 2003)","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"A functional ruthenium(ii) complex, [Ru(bpy)2(AN-bpy)](PF6)2 (bpy: 2,2'-bipyridine, AN-bpy: 4-methyl-4'-(4-amino-3-nitro-phenoxy-methylene)-2,2'-bipyridine), has been designed and synthesized as a turn-on luminescent probe for the imaging of hypochlorous acid (HOCl) in living cells. Due to the intramolecular photoinduced electron transfer (PET), the ruthenium(ii) complex itself is almost non-luminescent. However, it can specifically and rapidly react with HOCl in aqueous media to afford a highly luminescent derivative, [Ru(bpy)2(HM-bpy)](PF6)2 (HM-bpy: 4-hydroxymethyl-4'-methyl-2,2'-bipyridine), accompanied by a 110-fold luminescence enhancement. Taking advantage of high specificity and sensitivity, and excellent photophysical properties of the ruthenium(ii) complex probe, [Ru(bpy)2(AN-bpy)](PF6)2 was successfully applied to the luminescence imaging of the exogenous HOCl in living HeLa cells and the endogenous HOCl in porcine neutrophils. The results corroborate that indeed [Ru(bpy)2(AN-bpy)](PF6)2 is a useful luminescent probe for the monitoring of HOCl in biological systems.","pmid":"24740358","doi":"10.1039/c4dt00179f","url":"https://pubmed.ncbi.nlm.nih.gov/24740358/"},{"id":1692,"title":"Thermodynamic properties of chloramine formation and related reactions during water treatment: a G4MP2, G4, and W1BD theoretical study.","authors":"Rayne, Sierra; Forest, Kaya","year":2014,"date":"2014","journal":"Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"A high-level gas and aqueous phase theoretical thermodynamic study was conducted on the primary and related chemical reactions which occur during chloramination for water treatment using the G4MP2, G4, and W1BD composite methods with the SMD, PCM, and CPCM solvation models. The standard state (298.15 K, 1 atm or 1M) formation of mono-, di-, and tri-chloramines from their precursors via hypochlorous acid chlorination is substantially exothermic and exergonic in both the gas and aqueous phases. The excellent agreement between experimental and theoretical values for a range of structural and thermodynamic calculations on a suite of calibration compounds suggests that the G4MP2, G4, and W1BD calculations meet or exceed criteria for thermochemical accuracy. The temperature influence on the thermodynamics of chloramine formation is projected to be negligible regardless of phase between 0 and 100°C. Additional thermodynamic calculations were undertaken on associated chloramination reactions involving the disproportionation of monochloramine, the decomposition of di- and tri-chloramine, and the reactions of trichloramine with ammonia and dichloramine. The results from these investigations not only provide a better understanding of the reaction thermodynamics, they also allow for a more rigorous interpretation of proposed chloramination mechanisms.","pmid":"24679082","doi":"10.1080/10934529.2014.882180","url":"https://pubmed.ncbi.nlm.nih.gov/24679082/"},{"id":1696,"title":"Poisoning injuries associated with water and wastewater treatment facilities.","authors":"Forrester, Mathias B","year":2014,"date":"2014 Mar","journal":"Journal of occupational and environmental medicine","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"","pmid":"24603207","doi":"10.1097/JOM.0000000000000103","url":"https://pubmed.ncbi.nlm.nih.gov/24603207/"},{"id":1702,"title":"Cleaning of filtering facepiece respirators contaminated with mucin and Staphylococcus aureus.","authors":"Heimbuch, Brian K; Kinney, Kimberly; Lumley, April E; Harnish, Delbert A; Bergman, Michael; Wander, Joseph D","year":2014,"date":"2014 Mar","journal":"American journal of infection control","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Decontamination, cleaning, and reuse of filtering facepiece respirators (FFRs) has been proposed to mitigate an acute FFR shortage during a public health emergency. Our study evaluates the ability of commercially available wipe products to clean FFRs contaminated with either infectious or noninfectious aerosols. METHODS: Three models of surgical N95 FFRs were contaminated with aerosols of mucin or viable Staphylococcus aureus then cleaned with hypochlorite, benzalkonium chloride, or nonantimicrobial wipes. After cleaning, FFRs were separated into components (nose pad, fabrics, and perforated strip), and contaminants were extracted and quantified. Filtration performance was assessed for cleaned FFRs. RESULTS: Mucin removal was <1 log for all wipe products on all components. Inert wipes achieved ∼1-log attenuation in viable S aureus on fabrics from all FFR models--removal was less effective from nose pads and perforated edges. Both antimicrobial wipes achieved 3-5-log attenuation on most components, with smaller reductions on nose pads and greater reductions on perforated strips. Particle penetration following cleaning yielded mean values <5%. The highest penetrations were observed in FFRs cleaned with benzalkonium chloride wipes. CONCLUSIONS: FFRs can be disinfected using antimicrobial wipe products, but not effectively cleaned with the wipes evaluated in this study. This study provides informative data for the development of better FFRs and applicable cleaning products.","pmid":"24462175","doi":"10.1016/j.ajic.2013.09.014","url":"https://pubmed.ncbi.nlm.nih.gov/24462175/"},{"id":1704,"title":"The in vitro antimicrobial activity of wound and skin cleansers at nontoxic concentrations.","authors":"Rani, Suriani Abdul; Hoon, Russell; Najafi, Ramin Ron; Khosrovi, Behzad; Wang, Lu; Debabov, Dmitri","year":2014,"date":"2014 Feb","journal":"Advances in skin & wound care","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVE: To determine in vitro antibacterial activity of commercially available skin, wound, and skin/wound cleansers at cell-safe (nontoxic) concentrations. DESIGN: Saline and 19 other commercial wound and skin cleansers were evaluated for cytotoxic effects on mouse dermal fibroblasts. Cells were exposed to serial 10-fold dilutions of each cleanser until treatment-induced cytotoxicity was comparable to the baseline cytotoxicity of unexposed control fibroblasts. Antimicrobial \"time-kill\" kinetics of these test concentrations of cleansers was tested against methicillin-resistant Staphylococcus aureus. RESULTS: The experimental design allowed calculation of relative cytotoxicity indexes ranging from 0 to 100,000. Shur-Clens Restore Wound Cleanser (ConvaTec, Skillman, New Jersey) and saline were found to be the least toxic (toxicity index: 0); Hibiclens (Mölnlycke Health Care, Norcross, Georgia), Restore Skin Cleanser (Hollister Inc, Libertyville, Illinois), and Betadine Surgical Scrub (Pursue Products LP, Stamford, Connecticut) were found to be the most toxic (toxicity index: 10,000). At noncytotoxic concentrations, NeutroPhase (NovaBay Pharmaceuticals Inc, Emeryville, California) was the most rapidly bactericidal, achieving a 4-log reduction in colony-forming units in less than 1 minute. Puracyn (Innovacyn Inc, Rialto, California) was next at 30 minutes, whereas most of the agents tested required more than 24 hours. CONCLUSIONS: Wound healing depends on controlling bacterial balance while maintaining the viability of the healing tissues. In vitro toxicity indexes provide helpful guidelines subsequent to in vivo evaluations and clinical applications. The study findings suggest that NeutroPhase, in contrast with many commercially available wound cleansers, has rapid bactericidal activity at concentrations that are safe for human cells.","pmid":"24440863","doi":"10.1097/01.ASW.0000443255.73875.a3","url":"https://pubmed.ncbi.nlm.nih.gov/24440863/"},{"id":1706,"title":"Effect of hypochlorite oxidation on cholinesterase-inhibition assay of acetonitrile extracts from fruits and vegetables for monitoring traces of organophosphate pesticides.","authors":"Kitamura, Kentaro; Maruyama, Kaori; Hamano, Sachiko; Kishi, Tomohiro; Kawakami, Tsuyoshi; Takahashi, Yasuo; Onodera, Sukeo","year":2014,"date":"2014 Feb","journal":"The Journal of toxicological sciences","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"A reproducible method for monitoring traces of cholinesterase (ChE) inhibitors in acetonitrile extracts from fruits and vegetables is described. The method is based on hypochlorite oxidation and ChE inhibition assay. Four common representative samples of produce were selected from a supermarket to investigate the effect of different matrices on pesticides recoveries and assay precision. The samples were extracted with acetonitrile to prepare them for ChE inhibition assays: if necessary, clean-up was performed using dispersive solid-phase extraction for gas chromatography-mass spectrometry (GC/MS) analyses. Chlorine was tested as an oxidising reagent for the conversion of thiophosphorus pesticides (P=S compounds) into their P=O analogues, which have high ChE-inhibiting activity. Chlorine consumption of individual acetonitrile extracts was determined and was strongly dependent on the individual types of fruits and vegetables. After treating the acetonitrile extracts with an excess hypochlorite at 25°C for 15 min, the ChE-inhibiting activities and detection limits for each chlorine-treated pesticide solution were determined. Matrix composition did not interfere significantly with the determination of the pesticides. Enhanced anti-ChE activities leading to low detection limits (ppb levels) were observed for the chlorine-treated extracts that were spiked with chlorpyrifos, diazinon, fenitrothion, and isoxathion. This combination of oxidative derivatisation and ChE inhibition assays was used successfully to monitor and perform semi-quantitative determination of ChE inhibitors in apple, tomato, cucumber, and strawberry samples.","pmid":"24418711","doi":"10.2131/jts.39.71","url":"https://pubmed.ncbi.nlm.nih.gov/24418711/"},{"id":1707,"title":"Comparison of oxygen and hypochlorite as cathodic electron acceptor in microbial fuel cells.","authors":"Jadhav, D A; Ghadge, A N; Mondal, Debika; Ghangrekar, M M","year":2014,"date":"2014 Feb","journal":"Bioresource technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Effect of oxygen and sodium hypochlorite (NaOCl) as cathodic electron acceptors on performance of a clayware microbial fuel cell (MFC) was evaluated in this study. Maximum power density of 6.57 W/m(3) was obtained with NaOCl as catholyte, which is about 9 times higher than oxygen being used as an electron acceptor. Voltammetry and Tafel analysis further supported the faster reduction kinetics lead to increase in power output and reduction in internal resistance of MFC operated with NaOCl as an electron acceptor. Using NaOCl as catholyte, higher exchange current density of 10.91 and 11.52 mA/m(2) and lower charge transfer resistance of 0.58 and 0.56 kΩ m(2) was observed for anode and cathode, respectively. Higher organic matter removal of about 90% with 25% Coulombic efficiency was achieved using NaOCl as catholyte. Higher internal resistance, lower cathode potential and slow reduction kinetics deteriorated performance of MFC using oxygen as cathodic electron acceptor.","pmid":"24413450","doi":"10.1016/j.biortech.2013.12.069","url":"https://pubmed.ncbi.nlm.nih.gov/24413450/"},{"id":1710,"title":"Nicotine mediates hypochlorous acid-induced nuclear protein damage in mammalian cells.","authors":"Salama, Samir A; Arab, Hany H; Omar, Hany A; Maghrabi, Ibrahim A; Snapka, Robert M","year":2014,"date":"2014 Jun","journal":"Inflammation","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Activated neutrophils secrete hypochlorous acid (HOCl) into the extracellular space of inflamed tissues. Because of short diffusion distance in biological fluids, HOCl-damaging effect is restricted to the extracellular compartment. The current study aimed at investigating the ability of nicotine, a component of tobacco and electronic cigarettes, to mediate HOCl-induced intracellular damage. We report, for the first time, that HOCl reacts with nicotine to produce nicotine chloramine (Nic-Cl). Nic-Cl caused dose-dependent damage to proliferating cell nuclear antigen (PCNA), a nuclear protein, in cultured mammalian lung and kidney cells. Vitamin C, vitamin E analogue (Trolox), glutathione, and N-acetyl-L-cysteine inhibited the Nic-Cl-induced PCNA damage, implicating oxidation in PCNA damage. These findings point out the ability of nicotine to mediate HOCl-induced intracellular damage and suggest antioxidants as protective measures. The results also raise the possibility that Nic-Cl can be created in the inflamed tissues of tobacco and electronic cigarette smokers and may contribute to smoking-related diseases.","pmid":"24357417","doi":"10.1007/s10753-013-9797-6","url":"https://pubmed.ncbi.nlm.nih.gov/24357417/"},{"id":1712,"title":"A near-infrared fluorescent probe for selective detection of HClO based on Se-sensitized aggregation of heptamethine cyanine dye.","authors":"Cheng, Guanghui; Fan, Jiangli; Sun, Wen; Cao, Jianfang; Hu, Chong; Peng, Xiaojun","year":2014,"date":"2014 Jan 28","journal":"Chemical communications (Cambridge, England)","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"A Se-containing heptamethine cyanine dye based fluorescent probe was successfully developed and used for HClO detection with rapid response and high selectivity based on aggregation behavior. The probe could react with HClO with significant change in its fluorescence profile, which makes it practical for detecting HClO in fetal bovine serum and in living mice.","pmid":"24310167","doi":"10.1039/c3cc47864e","url":"https://pubmed.ncbi.nlm.nih.gov/24310167/"},{"id":1720,"title":"Rapid and ratiometric detection of hypochlorite with real application in tap water: molecules to low cost devices (TLC sticks).","authors":"Goswami, Shyamaprosad; Manna, Abhishek; Paul, Sima; Quah, Ching Kheng; Fun, Hoong-Kun","year":2013,"date":"2013 Dec 25","journal":"Chemical communications (Cambridge, England)","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"We have designed a chemodosimeter DPNO (weak fluorescence) which can be oxidized to HPNO (strong blue fluorescence) by OCl(-) with high selectivity and sensitivity in a ratiometric approach with a noticeably lower detection limit. The sensor could be useful for the detection of hypochlorites in tap water.","pmid":"24185489","doi":"10.1039/c3cc47121g","url":"https://pubmed.ncbi.nlm.nih.gov/24185489/"},{"id":1723,"title":"Comparative reactivity of the myeloperoxidase-derived oxidants hypochlorous acid and hypothiocyanous acid with human coronary artery endothelial cells.","authors":"Lloyd, Mitchell M; Grima, Michael A; Rayner, Benjamin S; Hadfield, Katrina A; Davies, Michael J; Hawkins, Clare L","year":2013,"date":"2013 Dec","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"In the immune response, hypohalous acids are generated by activated leukocytes via the release of myeloperoxidase and the formation of H2O2. Although these oxidants have important bactericidal properties, they have also been implicated in causing tissue damage in inflammatory diseases, including atherosclerosis. Hypochlorous acid (HOCl) and hypothiocyanous acid (HOSCN) are the major oxidants formed by myeloperoxidase under physiological conditions, with the ratio of these oxidants dependent on diet and smoking status. HOCl is highly reactive and causes marked cellular damage, but few data are available on the effects of HOSCN on mammalian cells. In this study, we have compared the actions of HOCl and HOSCN on human coronary artery endothelial cells (HCAEC). HOCl reacts rapidly with the cells, resulting in extensive cell death by both apoptosis and necrosis, with necrosis dominating at higher oxidant doses. In contrast, HOSCN is consumed more slowly, with cell death occurring only by apoptosis. Exposure of HCAEC to HOCl and HOSCN induces changes in mitochondrial membrane permeability, which, in the case of HOSCN, is associated with mitochondrial release of proapoptotic factors, including cytochrome c, apoptosis-inducing factor, and endonuclease G. With each oxidant, apoptosis appears to be caspase-independent, with the inactivation of caspases 3/7 observed, and pretreatment of the cells with the caspase inhibitor Z-VAD-fmk having no effect on the extent of cell death. Loss of cellular thiols, depletion of glutathione, and the inactivation of thiol-dependent enzymes, including glyceraldehyde-3-phosphate dehydrogenase, were seen with both oxidants, though to a much greater extent with HOCl. The ability of myeloperoxidase-derived oxidants to induce endothelial cell apoptosis may contribute to the formation of unstable lesions in atherosclerosis. The results with HOSCN may be particularly significant for smokers, who have elevated plasma levels of SCN(-), the precursor of this oxidant.","pmid":"24120969","doi":"10.1016/j.freeradbiomed.2013.10.007","url":"https://pubmed.ncbi.nlm.nih.gov/24120969/"},{"id":1725,"title":"Role of cysteines in the stability and DNA-binding activity of the hypochlorite-specific transcription factor HypT.","authors":"Drazic, Adrian; Tsoutsoulopoulos, Amelie; Peschek, Jirka; Gundlach, Jasmin; Krause, Maike; Bach, Nina C; Gebendorfer, Katharina M; Winter, Jeannette","year":2013,"date":"2013","journal":"PloS one","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Reactive oxygen species are important components of the immune response. Hypochlorite (HOCl) is produced by neutrophils to kill invading microorganisms. The bactericidal activity of HOCl is due to proteome-wide unfolding and oxidation of proteins at cysteine and methionine residues. Escherichia coli cells are protected from HOCl-killing by the previously identified dodecameric transcription factor HypT (YjiE). Here, we aimed to unravel whether HOCl activates HypT directly or via a reaction product of HOCl with a cellular component. Bacterial viability assays and analysis of target gene regulation indicate that HypT is highly specific to activation by HOCl and that no reaction products of HOCl such as monochloramine, hydroxyl radicals, or methionine sulfoxide activate HypT in vivo. Surprisingly, purified HypT lost its DNA-binding activity upon incubation with HOCl or reaction products that oxidize HypT to form a disulfide-linked dimer, and regained DNA-binding activity upon reduction. Thus, we postulate that the cysteines in HypT contribute to control the DNA-binding activity of HypT in vitro. HypT contains five cysteine residues; a HypT mutant with all cysteines substituted by serine is aggregation-prone and forms tetramers in addition to the typical dodecamers. Using single and multiple cysteine-to-serine mutants, we identified Cys150 to be required for stability and Cys4 being important for oligomerization of HypT to dodecamers. Further, oxidation of Cys4 is responsible for the loss of DNA-binding of HypT upon oxidation in vitro. It appears that Cys4 oxidation upon conditions that are insufficient to stimulate the DNA-binding activity of HypT prevents unproductive interactions of HypT with DNA. Thus, Cys4 oxidation may be a check point in the activation process of HypT.","pmid":"24116067","doi":"10.1371/journal.pone.0075683","url":"https://pubmed.ncbi.nlm.nih.gov/24116067/"},{"id":1726,"title":"Efficacy of dilute hypochlorite solutions and an electrochemically activated saline solution containing hypochlorous acid for disinfection of methicillin-resistant Staphylococcus aureus in a pig skin model.","authors":"Chang, Bailey; Nerandzic, Michelle M; Kundrapu, Sirisha; Sunkesula, Venkata C K; Deshpande, Abhishek; Donskey, Curtis J","year":2013,"date":"2013 Nov","journal":"Infection control and hospital epidemiology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"","pmid":"24113614","doi":"10.1086/673448","url":"https://pubmed.ncbi.nlm.nih.gov/24113614/"},{"id":1742,"title":"Aqueous chlorination of carbamazepine: kinetic study and transformation product identification.","authors":"Soufan, M; Deborde, M; Delmont, A; Legube, B","year":2013,"date":"2013 Sep 15","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Carbamazepine reactivity and fate during chlorination was investigated in this study. From a kinetic standpoint, a third-order reaction (first-order relative to the CBZ concentration and second-order relative to the free chlorine concentration) was observed at neutral and slightly acidic pH, whereas a second-order reaction (first order relative to the CBZ concentration and first order relative to the free chlorine concentration) was noted under alkaline conditions. In order to gain insight into the observed pH-dependence of the reaction order, elementary reactions (i.e. reactions of Cl2, Cl2O, HOCl with CBZ and of ClO(-) with CBZ or of HOCl with the ionized form of CBZ) were highlighted and second order rate constants of each of them were calculated. Close correlations between the experimental and modeled values were obtained under these conditions. Cl2 and Cl2O were the main chlorination agents at neutral and acidic pH. These results indicate that, for a 1 mg/L free chlorine concentration and 1-10 mg/L chloride concentration at pH 7, halflives about 52-69 days can be expected. A low reactivity of chlorine with CBZ could thus occur under the chlorination steps used during water treatment. From a mechanistic viewpoint, several transformation products were observed during carbamazepine chlorination. As previously described for the chlorination of polynuclear aromatic or unsaturated compounds, we proposed monohydroxylated, epoxide, diols or chlorinated alcohol derivatives of CBZ for the chemical structures of these degradation products. Most of these compounds seem to accumulate in solution in the presence of excess chlorine.","pmid":"23891541","doi":"10.1016/j.watres.2013.05.047","url":"https://pubmed.ncbi.nlm.nih.gov/23891541/"},{"id":1743,"title":"Bovine pulp tissue dissolution ability of HealOzone®, Aquatine Alpha Electrolyte® and sodium hypochlorite.","authors":"Rossi-Fedele, Giampiero; Steier, Liviu; Dogramaci, Esma Jane; Canullo, Luigi; Steier, Gabriela; de Figueiredo, Jose Antonio Poli","year":2013,"date":"2013 Aug","journal":"Australian endodontic journal : the journal of the Australian Society of Endodontology Inc","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The aim of this study was to evaluate the bovine pulp tissue dissolution ability of HealOzone, Aquatine Alpha Electrolyte® and 0.5% sodium hypochlorite, used alone or in combination. Thirty bovine pulp fragments were weighed, divided into six groups and placed individually in Eppendorf tubes containing the tested solution until total dissolution occurred. The groups were: G1: saline (negative control), G2: Aquatine Alpha Electrolyte®, G3: 0.5% NaOCl (positive control), G4: Saline + HealOzone, G5: 0.5% NaOCl + HealOzone, G6: Aquatine Alpha Electrolyte® + HealOzone. HealOzone was activated for 2 min with a #6 cup covering the test tube opening on a fixed platform. Two blinded observers using 2× loupes magnification assessed the samples continuously for the first 2 h, and then every hour for the next 8 h. Dissolution speed was calculated by dividing pulp weight by dissolution time (mg min(-1) ). G3 (NaOCl) and G5 (NaOCl + HealOzone) dissolved the pulp tissue completely. The mean dissolution speed for G3 was 0.396 mg min(-1) (SD 0.032) and for G5 was 0.775 mg min(-1) (SD 0.2). Student's t-test showed that G5 dissolved bovine pulp tissue faster than G3 (P = 0.01). Only groups containing sodium hypochlorite dissolved pulp tissue, whilst HealOzone enhanced speed of dissolution.","pmid":"23890260","doi":"10.1111/j.1747-4477.2010.00287.x","url":"https://pubmed.ncbi.nlm.nih.gov/23890260/"},{"id":1744,"title":"pH-dependent Si-fluorescein hypochlorous acid fluorescent probe: spirocycle ring-opening and excess hypochlorous acid-induced chlorination.","authors":"Best, Quinn A; Sattenapally, Narsimha; Dyer, Daniel J; Scott, Colleen N; McCarroll, Matthew E","year":2013,"date":"2013 Sep 11","journal":"Journal of the American Chemical Society","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"We report the synthesis and characterization of a fluorescent probe (Hypo-SiF) designed for the detection of hypochlorous acid (HOCl) using a silicon analogue of fluorescein (SiF). The probe is regulated in an \"off-on\" fashion by a highly selective thioether spirocyclic nonfluorescent structure that opens to form a mixture of fluorescent products in the presence of HOCl. Over a range of pH values, the probe reacts with a stoichiometric amount of HOCl, resulting in a mixture of two pH-dependent fluorescent species, a SiF disulfide product and a SiF sulfonate product. The unique colorimetric properties of the individual SiF fluorophores were utilized to perform simultaneous detection of HOCl and pH. When an excess of HOCl is present, the SiF fluorophores become chlorinated, via an intermediate halohydrin, resulting in a more pH independent and red-shifted fluorophore.","pmid":"23889259","doi":"10.1021/ja401426s","url":"https://pubmed.ncbi.nlm.nih.gov/23889259/"},{"id":1747,"title":"N-acetyl lysyltyrosylcysteine amide inhibits myeloperoxidase, a novel tripeptide inhibitor.","authors":"Zhang, Hao; Jing, Xigang; Shi, Yang; Xu, Hao; Du, Jianhai; Guan, Tongju; Weihrauch, Dorothee; Jones, Deron W; Wang, Weiling; Gourlay, David; Oldham, Keith T; Hillery, Cheryl A; Pritchard, Kirkwood A Jr","year":2013,"date":"2013 Nov","journal":"Journal of lipid research","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase (MPO) plays important roles in disease by increasing oxidative and nitrosative stress and oxidizing lipoproteins. Here we report N-acetyl lysyltyrosylcysteine amide (KYC) is an effective inhibitor of MPO activity. We show KYC inhibits MPO-mediated hypochlorous acid (HOCl) formation and nitration/oxidation of LDL. Disulfide is the major product of MPO-mediated KYC oxidation. KYC (≤4,000 μM) does not induce cytotoxicity in bovine aortic endothelial cells (BAECs). KYC inhibits HOCl generation by phorbol myristate acetate (PMA)-stimulated neutrophils and human promyelocytic leukemia (HL-60) cells but not superoxide generation by PMA-stimulated HL-60 cells. KYC inhibits MPO-mediated HOCl formation in BAEC culture and protects BAECs from MPO-induced injury. KYC inhibits MPO-mediated lipid peroxidation of LDL whereas tyrosine (Tyr) and tryptophan (Trp) enhance oxidation. KYC is unique as its isomers do not inhibit MPO activity, or are much less effective. Ultraviolet-visible spectral studies indicate KYC binds to the active site of MPO and reacts with compounds I and II. Docking studies show the Tyr of KYC rests just above the heme of MPO. Interestingly, KYC increases MPO-dependent H₂O₂ consumption. These data indicate KYC is a novel and specific inhibitor of MPO activity that is nontoxic to endothelial cell cultures. Accordingly, KYC may be useful for treating MPO-mediated vascular disease.","pmid":"23883583","doi":"10.1194/jlr.M038273","url":"https://pubmed.ncbi.nlm.nih.gov/23883583/"},{"id":1750,"title":"Fluorescent hydroxylamine derived from the fragmentation of PAMAM dendrimers for intracellular hypochlorite recognition.","authors":"Wu, Te-Haw; Liu, Ching-Ping; Chien, Chih-Te; Lin, Shu-Yi","year":2013,"date":"2013 Aug 26","journal":"Chemistry (Weinheim an der Bergstrasse, Germany)","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Herein, a promising sensing approach based on the structure fragmentation of poly(amidoamine) (PAMAM) dendrimers for the selective detection of intracellular hypochlorite (OCl(-)) is reported. PAMAM dendrimers were easily disrupted by a cascade of oxidations in the tertiary amines of the dendritic core to produce an unsaturated hydroxylamine with blue fluorescence. Specially, the novel fluorophore was only sensitive to OCl(-), one of reactive oxygen species (ROS), resulting in an irreversible fluorescence turn-off. The fluorescent hydroxylamine was selectively oxidised by OCl(-) to form a labile oxoammonium cation that underwent further degradation. Without using any troublesomely synthetic steps, the novel sensing platform based on the fragmentation of PAMAM dendrimers, can be applied to detect OCl(-) in macrophage cells. The results suggest that the sensing approach may be useful for the detection of intracellular OCl(-) with minimal interference from biological matrixes.","pmid":"23853105","doi":"10.1002/chem.201300494","url":"https://pubmed.ncbi.nlm.nih.gov/23853105/"},{"id":1751,"title":"Novel strategies for enhanced removal of persistent Bacillus anthracis surrogates and Clostridium difficile spores from skin.","authors":"Nerandzic, Michelle M; Rackaityte, Elze; Jury, Lucy A; Eckart, Kevin; Donskey, Curtis J","year":2013,"date":"2013","journal":"PloS one","category":"Water, sanitation & biosecurity","evidence":"Randomized controlled trial","relevance":"High","abstract":"BACKGROUND: Removing spores of Clostridium difficile and Bacillus anthracis from skin is challenging because they are resistant to commonly used antimicrobials and soap and water washing provides only modest efficacy. We hypothesized that hygiene interventions incorporating a sporicidal electrochemically generated hypochlorous acid solution (Vashe(®)) would reduce the burden of spores on skin. METHODS: Hands of volunteers were inoculated with non-toxigenic C. difficile spores or B. anthracis spore surrogates to assess the effectiveness of Vashe solution for reducing spores on skin. Reduction in spores was compared for Vashe hygiene interventions versus soap and water (control). To determine the effectiveness of Vashe solution for removal of C. difficile spores from the skin of patients with C. difficile infection (CDI), reductions in levels of spores on skin were compared for soap and water versus Vashe bed baths. RESULTS: Spore removal from hands was enhanced with Vashe soak (>2.5 log10 reduction) versus soap and water wash or soak (~2.0 log10 reduction; P<0.05) and Vashe wipes versus alcohol wipes (P<0.01). A combined approach of soap and water wash followed by soaking in Vashe removed >3.5 log10 spores from hands (P<0.01 compared to washing or soaking alone). Bed baths using soap and water (N =26 patients) did not reduce the percentage of positive skin cultures for CDI patients (64% before versus 57% after bathing; P =0.5), whereas bathing with Vashe solution (N =21 patients) significantly reduced skin contamination (54% before versus 8% after bathing; P =0.0001). Vashe was well-tolerated with no evidence of adverse effects on skin. CONCLUSIONS: Vashe was safe and effective for reducing the burden of B. anthracis surrogates and C. difficile spores on hands. Bed baths with Vashe were effective for reducing C. difficile on skin. These findings suggest a novel strategy to reduce the burden of spores on skin.","pmid":"23844234","doi":"10.1371/journal.pone.0068706","url":"https://pubmed.ncbi.nlm.nih.gov/23844234/"},{"id":1752,"title":"Neutrophils Turn Plasma Proteins into Weapons against HIV-1.","authors":"Speth, Cornelia; Brodde, Martin F; Hagleitner, Magdalena; Rambach, Günter; Van Aken, Hugo; Dierich, Manfred; Kehrel, Beate E","year":2013,"date":"2013","journal":"PloS one","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"As a consequence of innate immune activation granulocytes and macrophages produce hypochlorite/hypochlorous acid (HOCl) via secretion of myeloperoxidase (MPO) to the outside of the cells, where HOCl immediately reacts with proteins. Most proteins that become altered by this system do not belong to the invading microorganism but to the host. While there is no doubt that the myeloperoxidase system is capable of directly inactivating HIV-1, we hypothesized that it may have an additional indirect mode of action. We show in this article that HOCl is able to chemically alter proteins and thus turn them into Idea-Ps (Idea-P = immune defence-altered protein), potent amyloid-like and SH-groups capturing antiviral weapons against HIV-1. HOCl-altered plasma proteins (Idea-PP) have the capacity to bind efficiently and with high affinity to the HIV-1 envelope protein gp120, and to its receptor CD4 as well as to the protein disulfide isomerase (PDI). Idea-PP was able to inhibit viral infection and replication in a cell culture system as shown by reduced number of infected cells and of syncytia, resulting in reduction of viral capsid protein p24 in the culture supernatant. The unmodified plasma protein fraction had no effect. HOCl-altered isolated proteins antithrombin III and human serum albumin, taken as representative examples of the whole pool of plasma proteins, were both able to exert the same activity of binding to gp120 and inhibition of viral proliferation. These data offer an opportunity to improve the understanding of the intricacies of host-pathogen interactions and allow the generation of the following hypothetical scheme: natural immune defense mechanisms generate by posttranslational modification of plasma proteins a potent virucidal weapon that immobilizes the virus as well as inhibits viral fusion and thus entry into the host cells. Furthermore simulation of this mechanism in vitro might provide an interesting new therapeutic approach against microorganisms.","pmid":"23840401","doi":"10.1371/journal.pone.0066073","url":"https://pubmed.ncbi.nlm.nih.gov/23840401/"},{"id":1753,"title":"Effects of C-reactive protein on the neutrophil respiratory burst in vitro.","authors":"Ling, Martin R; Chapple, Iain L C; Creese, Andrew J; Matthews, John B","year":2014,"date":"2014 May","journal":"Innate immunity","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"This study determined the influence of physiologically relevant concentrations of C-reactive protein (CRP) on reactive oxygen species (ROS) production by neutrophils. Neutrophils from healthy individuals were incubated with soluble pentameric CRP prior to TLR stimulation with Fusobacterium nucleatum, or FcγR stimulation with IgG-opsonised Staphylococcus aureus or heat-aggregated IgG. ROS generation by unstimulated cells and those after stimulation were determined using luminol, isoluminol and lucigenin chemiluminescence, detecting predominantly intracellular hypochlorous acid (HOCl), extracellular hydrogen peroxide (detected as HOCl) and extracellular superoxide respectively. Baseline (unstimulated) neutrophil ROS generation and release was reduced compared with vehicle control by 10 µg/ml CRP. There was no consistent effect of CRP on FcγR-stimulated HOCl production, but the extracellular superoxide response was reduced by 10 µg/ml CRP. By contrast, CRP reduced intracellular (10 µg/ml) and extracellular (3 and 10 µg/ml) HOCl generation, but increased superoxide release (1-10 µg/ml) in response to TLR stimulation. Physiologically relevant concentrations of CRP inhibited baseline ROS generation and reduced FcγR-stimulated extracellular superoxide and TLR-stimulated HOCl release, suggesting that CRP may offer some degree of host protection from neutrophil-associated, low-level oxidative stress. However, CRP enhanced TLR-mediated superoxide release from neutrophils, potentially increasing oxidative stress but aiding host protection from infection.","pmid":"23839528","doi":"10.1177/1753425913493199","url":"https://pubmed.ncbi.nlm.nih.gov/23839528/"},{"id":1754,"title":"A dendritic cell vaccine pulsed with autologous hypochlorous acid-oxidized ovarian cancer lysate primes effective broad antitumor immunity: from bench to bedside.","authors":"Chiang, Cheryl Lai-Lai; Kandalaft, Lana E; Tanyi, Janos; Hagemann, Andrea R; Motz, Gregory T; Svoronos, Nikolaos; Montone, Kathleen; Mantia-Smaldone, Gina M; Smith, Lori; Nisenbaum, Harvey L; Levine, Bruce L; Kalos, Michael; Czerniecki, Brian J; Torigian, Drew A; Powell, Daniel J Jr; Mick, Rosemarie; Coukos, George","year":2013,"date":"2013 Sep 1","journal":"Clinical cancer research : an official journal of the American Association for Cancer Research","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"PURPOSE: Whole tumor lysates are promising antigen sources for dendritic cell (DC) therapy as they contain many relevant immunogenic epitopes to help prevent tumor escape. Two common methods of tumor lysate preparations are freeze-thaw processing and UVB irradiation to induce necrosis and apoptosis, respectively. Hypochlorous acid (HOCl) oxidation is a new method for inducing primary necrosis and enhancing the immunogenicity of tumor cells. EXPERIMENTAL DESIGN: We compared the ability of DCs to engulf three different tumor lysate preparations, produce T-helper 1 (TH1)-priming cytokines and chemokines, stimulate mixed leukocyte reactions (MLR), and finally elicit T-cell responses capable of controlling tumor growth in vivo. RESULTS: We showed that DCs engulfed HOCl-oxidized lysate most efficiently stimulated robust MLRs, and elicited strong tumor-specific IFN-γ secretions in autologous T cells. These DCs produced the highest levels of TH1-priming cytokines and chemokines, including interleukin (IL)-12. Mice vaccinated with HOCl-oxidized ID8-ova lysate-pulsed DCs developed T-cell responses that effectively controlled tumor growth. Safety, immunogenicity of autologous DCs pulsed with HOCl-oxidized autologous tumor lysate (OCDC vaccine), clinical efficacy, and progression-free survival (PFS) were evaluated in a pilot study of five subjects with recurrent ovarian cancer. OCDC vaccination produced few grade 1 toxicities and elicited potent T-cell responses against known ovarian tumor antigens. Circulating regulatory T cells and serum IL-10 were also reduced. Two subjects experienced durable PFS of 24 months or more after OCDC. CONCLUSIONS: This is the first study showing the potential efficacy of a DC vaccine pulsed with HOCl-oxidized tumor lysate, a novel approach in preparing DC vaccine that is potentially applicable to many cancers.","pmid":"23838316","doi":"10.1158/1078-0432.CCR-13-1185","url":"https://pubmed.ncbi.nlm.nih.gov/23838316/"},{"id":1756,"title":"Protection of flavonoids against hypochlorite-induced protein modifications.","authors":"Siwak, Justyna; Lewinska, Anna; Wnuk, Maciej; Bartosz, Grzegorz","year":2013,"date":"2013 Nov 15","journal":"Food chemistry","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Plant polyphenols, such as flavonoids, are ubiquitous components of human diet, and have been recognised as efficient radical scavengers and antioxidants. Their protective effects were especially seen in cell-free assays. Whilst in living cells, depending on experimental conditions, polyphenols may manifest both anti- and pro-oxidative activity. In the present study, the effectiveness of fifteen structurally different flavonoids against hypochlorite-mediated changes in in vitro systems, with and without cells, was tested and compared. Quercetin was found to be the best protector against hypochlorite-mediated fluorescein bleaching and BSA thiol groups oxidation, whilst in living cells its effects on hypochlorite-associated cytotoxicity were moderate. Contrary, epigallocatechin gallate, pelargonidin and catechin, with less impressive hypochlorite scavenging activity in cell-free assays, were the most effective against 3-chlorotyrosine formation after hypochlorite treatment. Taken together, special care should be taken when extrapolating the results on antioxidant propensity of food bioactive compounds in vitro to the cellular milieu.","pmid":"23790908","doi":"10.1016/j.foodchem.2013.04.018","url":"https://pubmed.ncbi.nlm.nih.gov/23790908/"},{"id":1762,"title":"Antioxidant activity and inhibitory effects of lead (Leucaena leucocephala) seed extracts against lipid oxidation in model systems.","authors":"Benjakul, Soottawat; Kittiphattanabawon, Phanat; Shahidi, Fereidoon; Maqsood, Sajid","year":2013,"date":"2013 Aug","journal":"Food science and technology international = Ciencia y tecnologia de los alimentos internacional","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Antioxidant activity of brown lead (Leucaena leucocephala) seed extracts with and without prior chlorophyll removal was studied in comparison with mimosine. Both extracts showed similar hydroxyl radical (HO(•)) scavenging activity, hydrogen peroxide (H2O2) scavenging activity, singlet oxygen inhibition and hypochlorous acid (HOCl) scavenging capacity (p > 0.05). Nevertheless, the extract without prior chlorophyll removal had higher oxygen radical absorbance capacity than that with prior chlorophyll removal (p < 0.05). Generally, lead seed extracts with and without prior chlorophyll removal possessed a lower antioxidant activity, compared with mimosine. When lead seed extract without prior chlorophyll removal (100 and 200 ppm) was used in different lipid oxidation model systems, including β-carotene-linoleic acid and lecithin liposome systems, the preventive effect toward lipid oxidation was dose-dependent. At the same level of use, mimosine exhibited a higher efficacy in prevention of lipid oxidation in both systems as indicated by the lower increases in thiobarbituric acid reactive substances. A similar result was obtained in minced mackerel. Therefore, lead seed extract containing mimosine could act as a natural antioxidant to prevent lipid oxidation in foods.","pmid":"23729420","doi":"10.1177/1082013212455186","url":"https://pubmed.ncbi.nlm.nih.gov/23729420/"},{"id":1764,"title":"One-electron oxidation and reduction of glycosaminoglycan chloramides: a kinetic study.","authors":"Sibanda, S; Parsons, B J; Houee-Levin, C; Marignier, J-L; Paterson, A W J; Heyes, D J","year":2013,"date":"2013 Oct","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Hypochlorous acid and its acid-base counterpart, hypochlorite ions, produced under inflammatory conditions, may produce chloramides of glycosaminoglycans, these being significant components of the extracellular matrix (ECM). This may occur through the binding of myeloperoxidase directly to the glycosaminoglycans. The N-Cl group in the chloramides is a potential selective target for both reducing and oxidizing radicals, leading possibly to more efficient and damaging fragmentation of these biopolymers relative to the parent glycosaminoglycans. In this study, the fast reaction techniques of pulse radiolysis and nanosecond laser flash photolysis have been used to generate both oxidizing and reducing radicals to react with the chloramides of hyaluronan (HACl) and heparin (HepCl). The strong reducing formate radicals and hydrated electrons were found to react rapidly with both HACl and HepCl with rate constants of 1-1.7 × 10(8) and 0.7-1.2 × 10(8)M(-1)s(-1) for formate radicals and 2.2 × 10(9) and 7.2 × 10(8)M(-1)s(-1) for hydrated electrons, respectively. The spectral characteristics of the products of these reactions were identical and were consistent with initial attack at the N-Cl groups, followed by elimination of chloride ions to produce nitrogen-centered radicals, which rearrange subsequently and rapidly to produce C-2 radicals on the glucosamine moiety, supporting an earlier EPR study by M.D. Rees et al. (J. Am. Chem. Soc.125: 13719-13733; 2003). The oxidizing hydroxyl radicals also reacted rapidly with HACl and HepCl with rate constants of 2.2 × 10(8) and 1.6 × 10(8)M(-1)s(-1), with no evidence from these data for any degree of selective attack on the N-Cl group relative to the N-H groups and other sites of attack. The carbonate anion radicals were much slower with HACl and HepCl than hydroxyl radicals (1.0 × 10(5) and 8.0 × 10(4)M(-1)s(-1), respectively) but significantly faster than with the parent molecules (3.5 × 10(4) and 5.0 × 10(4)M(-1)s(-1), respectively). These findings suggest that these potential in vivo radicals may react in a site-specific manner with the N-Cl group in the glycosaminoglycan chloramides of the ECM, possibly to produce more efficient fragmentation. This is the first study therefore to conclusively demonstrate that reducing radicals react rapidly with glycosaminoglycan chloramides in a site-specific attack at the N-Cl group, probably to produce a 100% efficient biopolymer fragmentation process. Although less reactive, carbonate radicals, which may be produced in vivo via reactions of peroxynitrite with serum levels of carbon dioxide, also appear to react in a highly site-specific manner at the N-Cl group. It is not yet known if such site-specific attacks by this important in vivo species lead to a more efficient fragmentation of the biopolymers than would be expected for attack by the stronger oxidizing species, the hydroxyl radical. It is clear, however, that the N-Cl group formed under inflammatory conditions in the extracellular matrix does present a more likely target for both reactive oxygen species and reducing species than the N-H groups in the parent glycosaminoglycans.","pmid":"23684776","doi":"10.1016/j.freeradbiomed.2013.05.012","url":"https://pubmed.ncbi.nlm.nih.gov/23684776/"},{"id":1767,"title":"Selective metabolism of hypothiocyanous acid by mammalian thioredoxin reductase promotes lung innate immunity and antioxidant defense.","authors":"Chandler, Joshua D; Nichols, David P; Nick, Jerry A; Hondal, Robert J; Day, Brian J","year":2013,"date":"2013 Jun 21","journal":"The Journal of biological chemistry","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"The endogenously produced oxidant hypothiocyanous acid (HOSCN) inhibits and kills pathogens but paradoxically is well tolerated by mammalian host tissue. Mammalian high molecular weight thioredoxin reductase (H-TrxR) is evolutionarily divergent from bacterial low molecular weight thioredoxin reductase (L-TrxR). Notably, mammalian H-TrxR contains a selenocysteine (Sec) and has wider substrate reactivity than L-TrxR. Recombinant rat cytosolic H-TrxR1, mouse mitochondrial H-TrxR2, and a purified mixture of both from rat selectively turned over HOSCN (kcat = 357 ± 16 min(-1); Km = 31.9 ± 10.3 μM) but were inactive against the related oxidant hypochlorous acid. Replacing Sec with Cys or deleting the final eight C-terminal peptides decreased affinity and turnover of HOSCN by H-TrxR. Similarly, glutathione reductase (an H-TrxR homologue lacking Sec) was less effective at HOSCN turnover. In contrast to H-TrxR and glutathione reductase, recombinant Escherichia coli L-TrxR was potently inhibited by HOSCN (IC50 = 2.75 μM). Similarly, human bronchial epithelial cell (16HBE) lysates metabolized HOSCN, but E. coli and Pseudomonas aeruginosa lysates had little or no activity. HOSCN selectively produced toxicity in bacteria, whereas hypochlorous acid was nonselectively toxic to both bacteria and 16HBE. Treatment with the H-TrxR inhibitor auranofin inhibited HOSCN metabolism in 16HBE lysates and significantly increased HOSCN-mediated cytotoxicity. These findings demonstrate both the metabolism of HOSCN by mammalian H-TrxR resulting in resistance to HOSCN in mammalian cells and the potent inhibition of bacterial L-TrxR resulting in cytotoxicity in bacteria. These data support a novel selective mechanism of host defense in mammals wherein HOSCN formation simultaneously inhibits pathogens while sparing host tissue.","pmid":"23629660","doi":"10.1074/jbc.M113.468090","url":"https://pubmed.ncbi.nlm.nih.gov/23629660/"},{"id":1772,"title":"Nebulized thiocyanate improves lung infection outcomes in mice.","authors":"Chandler, J D; Min, E; Huang, J; Nichols, D P; Day, B J","year":2013,"date":"2013 Jul","journal":"British journal of pharmacology","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"BACKGROUND AND PURPOSE: Nebulized saline solutions are used in the treatment of multiple pulmonary diseases including cystic fibrosis (CF), asthma and chronic obstructive pulmonary disease (COPD). The benefits of these therapies include improved lung function, phlegm clearance and fewer lung infections. The thiocyanate anion (SCN) is a normal component of the airway epithelial lining fluid (ELF) secreted by pulmonary epithelia with antioxidant and host defence functions. We sought to test if SCN could be nebulized to combat lung infection by bolstering innate immune defence and antioxidant capacity. EXPERIMENTAL APPROACH: We established an effective antioxidant concentration of SCN in vitro using a bronchiolar epithelial cell line. We then developed a nebulization method of SCN in mice that increased ELF SCN above this concentration up to 12 h and used this method in a prolonged Pseudomonas aeruginosa infection model to test if increasing SCN improved host defence and infection outcomes. KEY RESULTS: SCN protected against cytotoxicity in vitro from acute and sustained exposure to inflammation-associated oxidative stress. Nebulized SCN effectively reduced bacterial load, infection-mediated morbidity and airway inflammation in mice infected with P. aeruginosa. SCN also sustained adaptive increases in reduced GSH in infected mice. CONCLUSIONS AND IMPLICATIONS: SCN is a dually protective molecule able to both enhance host defence and decrease tissue injury and inflammation as an antioxidant. Nebulized SCN could be developed to combat lung infections and inflammatory lung disease.","pmid":"23586967","doi":"10.1111/bph.12206","url":"https://pubmed.ncbi.nlm.nih.gov/23586967/"},{"id":1777,"title":"Sporicidal efficacy of pH-adjusted bleach for control of bioburden on production facility surfaces.","authors":"Frazer, Anne Cornish; Smyth, Josephine N; Bhupathiraju, Vishvesh K","year":2013,"date":"2013 Jun","journal":"Journal of industrial microbiology & biotechnology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"pH-adjusted bleach was one of the agents used to disinfect contaminated public buildings in the USA following the 2001 bioterrorist attack with Bacillus anthracis spores. A USEPA fact sheet describes the preparation of pH-adjusted bleach by combining diluted sodium hypochlorite (NaOCl) with a controlled amount of 5 % acetic acid. This paper reports a modification of this procedure to qualify the use of pH-adjusted bleach for routine disinfection of cleanroom surfaces in pharmaceutical manufacturing facilities whenever a short contact time is desirable or there is a need for enhanced germicidal or sporicidal activity. Adjustment of pH was obtained reproducibly with either acetic acid or HCl, confirming the feasibility of developing standard procedures for the controlled addition of acid to diluted NaOCl solutions without compromising operator safety and convenience. Efficacy testing using spores from an in-house isolate of Bacillus pumilus confirmed that NaOCl solutions in the pH 5-8 range have much greater sporicidal activity on surfaces than do unadjusted alkaline solutions (pH > 11). With a contact time of 0.5 min, the log10 reduction in spore viable counts was >5.4 for the five representative surfaces tested relative to untreated controls. Solutions of pH-adjusted NaOCl are known to be less stable than unadjusted alkaline solutions. Stability studies were performed by monitoring sporicidal efficacy, level of free available chlorine (FAC), and pH. Testing included several NaOCl concentrations and adjustment to different starting pHs. The efficacy of pH-adjusted solutions persisted in open containers for at least 12 h even though some FAC degradation occurred. In addition, solutions of 0.29 or 0.50 % NaOCl stored at room temperature protected from light retained efficacy for at least 4 weeks, indicating that short-term storage of solutions is possible following pH adjustment. The inorganic chemical degradation of pH-adjusted NaOCl solutions generates chlorate ion, an undesirable by-product. A comparison of chemical stability for 0.12, 0.25, and 0.50 % NaOCl solutions adjusted to different initial pHs indicated that the least chlorate formation occurred with 0.12 % NaOCl.","pmid":"23532317","doi":"10.1007/s10295-013-1257-7","url":"https://pubmed.ncbi.nlm.nih.gov/23532317/"},{"id":1778,"title":"Modelling trihalomethanes formation in water supply systems.","authors":"Di Cristo, Cristiana; Esposito, Giovanni; Leopardi, Angelo","year":2013,"date":"2013 Jan-Feb","journal":"Environmental technology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Chlorination is the most widely used method for disinfection of drinking water, but there are concerns about the formation of by-products, such as trihalomethanes (THMs), since the chronic exposure to them may pose risks to human health. For these reasons regulations fix maximum acceptable THMs levels throughout distribution networks, so it is very important to be able to correctly reproduce their formation. In the literature many models for predicting THMs formation have been developed, both based on empirical relationships and on kinetics involved during chlorine reactions. In this work the use of some of these models and their reliability in real situations is investigated through the application to the Aurunci-Valcanneto Water Supply System in Southern Lazio (Italy). The comparison of the performances of 18 selected literature empirical models furnishes interesting observations, indicating that the formula, developed using field data, results in being more suitable for reproducing THMs formation for the presented case study. Other considerations are also offered from the comparison with the results obtained using a simple first order kinetic model, calibrated using measured data.","pmid":"23530316","doi":"10.1080/09593330.2012.679702","url":"https://pubmed.ncbi.nlm.nih.gov/23530316/"},{"id":1780,"title":"Distribution and infection-related functions of bacillithiol in Staphylococcus aureus.","authors":"Pöther, Dierk-Christoph; Gierok, Philipp; Harms, Manuela; Mostertz, Jörg; Hochgräfe, Falko; Antelmann, Haike; Hamilton, Chris J; Borovok, Ilya; Lalk, Michael; Aharonowitz, Yair; Hecker, Michael","year":2013,"date":"2013 Apr","journal":"International journal of medical microbiology : IJMM","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Bacillithiol (Cys-GlcN-malate, BSH) serves as a major low molecular weight thiol in low GC Gram-positive bacteria including Bacillus species and a variety of Staphylococcus aureus strains. These bacteria do not produce glutathione (GSH). In this study, HPLC analyses were used to determine BSH levels in different S. aureus strains. Furthermore, the role of BSH in the resistance against oxidants and antibiotics and its function in virulence was investigated. We and others (Newton, G.L., Fahey, R.C., Rawat, M., 2012. Microbiology 158, 1117-1126) found that BSH is not produced by members of the S. aureus NCTC8325 lineage, such as strains 8325-4 and SH1000. Using bioinformatics we show that the BSH-biosynthetic gene bshC is disrupted by an 8-bp duplication in S. aureus NCTC8325. The functional bshC-gene from BSH-producing S. aureus Newman (NWMN_1087) was expressed in S. aureus 8325-4 to reconstitute BSH-synthesis. Comparison of the BSH-producing and BSH-minus strains revealed higher resistance of the BSH-producing strain against the antibiotic fosfomycin and the oxidant hypochlorite but not against hydrogen peroxide or diamide. In addition, a higher bacterial load of the BSH-producing strain was detected in human upper-airway epithelial cells and murine macrophages. This indicates a potential role of BSH in protection of S. aureus during infection.","pmid":"23517692","doi":"10.1016/j.ijmm.2013.01.003","url":"https://pubmed.ncbi.nlm.nih.gov/23517692/"},{"id":1785,"title":"Super-oxidized solution (Dermacyn Wound Care) as adjuvant treatment in the postoperative management of complicated diabetic foot osteomyelitis: preliminary experience in a specialized department.","authors":"Aragón-Sánchez, Javier; Lázaro-Martínez, Jose Luis; Quintana-Marrero, Yurena; Sanz-Corbalán, Irene; Hernández-Herrero, Maria J; Cabrera-Galván, Juan J","year":2013,"date":"2013 Jun","journal":"The international journal of lower extremity wounds","category":"Human clinical & healthcare","evidence":"Case report","relevance":"Medium","abstract":"Surgery is usually used to treat diabetic foot osteomyelitis (DFO), whether primarily or in cases in which antibiotics are not able to control infection. In many cases, the bone is only partially removed, which means that residual infection remains in the bone margins, and the wound is left open to heal by secondary intent. The use of culture-guided postoperative antibiotic treatment and adequate management of the wound must be addressed. No trials exist dealing with local treatment in the postoperative management of these cases of complicated DFO. We decided to test a super-oxidized solution, Dermacyn Wound Care (DWC; Oculus Innovative Sciences Netherlands BV, Sittard, Netherlands) to obtain preliminary experience in patients in whom infected bone remained in the surgical wounds. Our hypothesis was that DWC could be useful to control infection in the residual infected bone and surrounding soft tissues and would thus facilitate healing. Fourteen consecutive patients who underwent conservative surgery for DFO, in whom clean bone margins could not be assured, were treated in the postoperative period with DWC. Eleven cases were located in the forefoot, 6 on the first ray and the rest in lesser toes, 1 in the Lisfranc joint, and 2 on the calcaneus. No side effects appeared during treatment. Neither allergies nor skin dermatitis were found. Limb salvage was successfully achieved in 100% of the cases. Healing was achieved in a median period of 6.8 weeks.","pmid":"23446366","doi":"10.1177/1534734613476710","url":"https://pubmed.ncbi.nlm.nih.gov/23446366/"},{"id":1786,"title":"Myeloperoxidase deficiency induces MIP-2 production via ERK activation in zymosan-stimulated mouse neutrophils.","authors":"Tateno, N; Matsumoto, N; Motowaki, T; Suzuki, K; Aratani, Y","year":2013,"date":"2013 May","journal":"Free radical research","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Myeloperoxidase (MPO), a major constituent of neutrophils, catalyzes the production of hypochlorous acid (HOCl) from hydrogen peroxide (H2O2) and chloride anion. We have previously reported that MPO-deficient (MPO(-/-)) neutrophils produce greater amount of macrophage inflammatory protein-2 (MIP-2) in vitro than do wild type when stimulated with zymosan. In this study, we investigated the molecular mechanisms governing the up-regulation of MIP-2 production in the mutant neutrophils. Interestingly, we found that zymosan-induced production of MIP-2 was blocked by pre-treatment with U0126, an inhibitor of mitogen-activated protein kinase/extracellular-signal-regulated kinase (ERK), and with BAY11-7082, an inhibitor of nuclear factor (NF)-κB. Western blot analysis indicated that U0126 also inhibited the phosphorylation of p65 subunit of NF-κB (p65), indicating that MIP-2 was produced via the ERK/NF-κB pathway. Intriguingly, we found that ERK1/2, p65, and alpha subunit of inhibitor of κB (IκBα) in the MPO(-/-) neutrophils were phosphorylated more strongly than in the wild type when stimulated with zymosan. Exogenous H2O2 treatment in addition to zymosan stimulation enhanced the phosphorylation of ERK1/2 without affecting the zymosan-induced MIP-2 production. In contrast, exogenous HOCl inhibited the production of MIP-2 as well as IκBα phosphorylation without affecting ERK activity. The zymosan-induced production of MIP-2 in the wild-type neutrophils was enhanced by pre-treatment of the MPO inhibitor 4-aminobenzoic acid hydrazide. Collectively, these results strongly suggest that both lack of HOCl and accumulation of H2O2 due to MPO deficiency contribute to the up-regulation of MIP-2 production in mouse neutrophils stimulated with zymosan.","pmid":"23438680","doi":"10.3109/10715762.2013.778990","url":"https://pubmed.ncbi.nlm.nih.gov/23438680/"},{"id":1788,"title":"Carotenoids and phenolic compounds from Solanum sessiliflorum, an unexploited Amazonian fruit, and their scavenging capacities against reactive oxygen and nitrogen species.","authors":"Rodrigues, Eliseu; Mariutti, Lilian R B; Mercadante, Adriana Z","year":2013,"date":"2013 Mar 27","journal":"Journal of agricultural and food chemistry","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The composition of carotenoids and phenolic compounds from mana-cubiu (Solanum sessiliflorum), a fruit native to Amazonia, was determined by high-performance liquid chromatography coupled to diode array and mass spectrometry detectors (HPLC-DAD-MS(n)). The antioxidant capacities of the hydrophilic and carotenoid extracts against some reactive oxygen (ROO(•), H(2)O(2), HOCl, and HO(•)) and nitrogen (ONOO(-)) species were also determined. Seventeen carotenoids and three phenolic compounds were found in mana-cubiu. The major carotenoids were (all-E)-β-carotene (7.15 μg/g of dry weight) and (all-E)-lutein (2.41 μg/g of dry weight). The 5-caffeoylquinic acid (1351 μg/g of dry weight) was the major phenolic compound, representing more than 78% (w/w) of the total phenolic compounds. Moreover, two dihydrocaffeoyl spermidines were found in the hydrophilic extract. Both mana-cubiu extracts were able to scavenge all the tested reactive species. The carotenoid extract was shown to be a potent scavenger of peroxyl radical, while the hydrophilic extract was a potent hydrogen peroxide and hypochlorous acid scavenger.","pmid":"23432472","doi":"10.1021/jf3054214","url":"https://pubmed.ncbi.nlm.nih.gov/23432472/"},{"id":1790,"title":"Discrimination of infectious hepatitis A viruses by propidium monoazide real-time RT-PCR.","authors":"Sánchez, Gloria; Elizaquível, Patricia; Aznar, Rosa","year":2012,"date":"2012 Mar","journal":"Food and environmental virology","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"The discrimination of infectious and inactivated viruses remains a key obstacle when using quantitative RT-PCR (RT-qPCR) to quantify enteric viruses. In this study, propidium monoazide (PMA) and RNase pretreatments were evaluated for the detection and quantification of infectious hepatitis A virus (HAV). For thermally inactivated HAV, PMA treatment was more effective than RNase treatment for differentiating infectious and inactivated viruses, with HAV titers reduced by more than 2.4 log(10) units. Results showed that combining 50 μM of PMA and RT-qPCR selectively quantify infectious HAV in media suspensions. Therefore, PMA treatment previous to RT-qPCR detection is a promising alternative to assess HAV infectivity.","pmid":"23412764","doi":"10.1007/s12560-011-9074-5","url":"https://pubmed.ncbi.nlm.nih.gov/23412764/"},{"id":1793,"title":"Direct electric current treatment under physiologic saline conditions kills Staphylococcus epidermidis biofilms via electrolytic generation of hypochlorous acid.","authors":"Sandvik, Elizabeth L; McLeod, Bruce R; Parker, Albert E; Stewart, Philip S","year":2013,"date":"2013","journal":"PloS one","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The purpose of this study was to investigate the mechanism by which a direct electrical current reduced the viability of Staphylococcus epidermidis biofilms in conjunction with ciprofloxacin at physiologic saline conditions meant to approximate those in an infected artificial joint. Biofilms grown in CDC biofilm reactors were exposed to current for 24 hours in 1/10(th) strength tryptic soy broth containing 9 g/L total NaCl. Dose-dependent log reductions up to 6.7 log(10) CFU/cm(2) were observed with the application of direct current at all four levels (0.7 to 1.8 mA/cm(2)) both in the presence and absence of ciprofloxacin. There were no significant differences in log reductions for wells with ciprofloxacin compared to those without at the same current levels. When current exposures were repeated without biofilm or organics in the medium, significant generation of free chlorine was measured. Free chlorine doses equivalent to the 24 hour endpoint concentration for each current level were shown to mimic killing achieved by current application. Current exposure (1.8 mA/cm(2)) in medium lacking chloride and amended with sulfate, nitrate, or phosphate as alternative electrolytes produced diminished kills of 3, 2, and 0 log reduction, respectively. Direct current also killed Pseudomonas aeruginosa biofilms when NaCl was present. Together these results indicate that electrolysis reactions generating hypochlorous acid from chloride are likely a main contributor to the efficacy of direct current application. A physiologically relevant NaCl concentration is thus a critical parameter in experimental design if direct current is to be investigated for in vivo medical applications.","pmid":"23390518","doi":"10.1371/journal.pone.0055118","url":"https://pubmed.ncbi.nlm.nih.gov/23390518/"},{"id":1797,"title":"Vascular peroxidase 1: a novel enzyme in promoting oxidative stress in cardiovascular system.","authors":"Ma, Qi-Lin; Zhang, Guo-Gang; Peng, Jun","year":2013,"date":"2013 Jul","journal":"Trends in cardiovascular medicine","category":"Food & agriculture","evidence":"Review","relevance":"High","abstract":"Vascular peroxidase 1 (VPO1) is a recently identified novel family member of peroxidases in cardiovascular system. As an enzyme that is downstream of NADPH oxidases (NOX), VPO1 functions to utilize NOX - derived hydrogen peroxide (H2O2) to produce hypochlorous acid (HOCl), a strong oxidant which is believed to greatly promote oxidative stress. Under multiple conditions, NOX is activated concomitantly with an increase in superoxide anion (O2(.-)) and H2O2 production. The latter is converted to HOCl by VPO1. In this process (O2(.-) → H2O2 → HOCl), the oxidant reactivities of reactive oxygen species (ROS) are significantly increased and therefore the oxidative stress is dramatically amplified. Several lines of evidence suggest that the NOX/VPO1 pathway - mediated oxidative stress plays an important role in myocardial ischemia-reperfusion injury, endothelial cell apoptosis and/or smooth muscle cell proliferation. In addition, VPO1 can be secreted into the extracellular space to participate in extracellular matrix formation, suggesting that VPO1 may also play a role in cardiovascular remodeling (such as fibrosis). This function is independent of the peroxidase activity of VPO1.","pmid":"23357484","doi":"10.1016/j.tcm.2012.11.002","url":"https://pubmed.ncbi.nlm.nih.gov/23357484/"},{"id":1799,"title":"Interaction between chlorhexidine-impregnated gutta-percha points and several chlorine-containing endodontic irrigating solutions.","authors":"Rossi-Fedele, G; Doğramacı, E J; Steier, L; de Figueiredo, J A P","year":2013,"date":"2013 Jul","journal":"International endodontic journal","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"AIM: To evaluate if the immersion of chlorhexidine-impregnated gutta-percha points in chlorine-containing endodontic irrigants causes colour changes and precipitate formation. METHODOLOGY: Eighty-one size 25 chlorhexidine medicated (Activ Points, Roeko, Langenau, Germany) and 27 size 25 standard gutta-percha points (Roeko) were immersed in microtubes, containing the following solutions: 0.5 and 5.25% NaOCl or Aquatine (Optident, Ilkley, UK). The samples were visually assessed, by two independent observers, at regular intervals over 3 weeks, to detect colour changes and precipitate formation. A score system was used to grade the precipitate intensity. To compare the number of days required for a precipitate to form mean and standard differences were calculated; the means between the groups were compared using a one-way analysis of variance test. Mean intensity scores were calculated and compared between groups using Kruskal-Wallis procedure followed by the Mann-Whitney test. RESULTS: The groups containing 5.25% NaOCl started to produce a visible precipitate after fourteen days (16.48 ± 0.98) for the Activ points; this process was first noticed with the standard gutta-percha group on day 17 (18.33 ± 1.22 days), with a statistically significant difference (P = 0.002). When looking at the intensity scores from day 17 onwards, these two groups differed statistically, with a greater amount for the AP group (P < 0.001). No other test group presented with changes. CONCLUSION: The placement of impregnated gutta-percha points, in 5.25% NaOCl for a 2-week period, caused the formation of a precipitate in the experimental conditions of this study.","pmid":"23331158","doi":"10.1111/iej.12044","url":"https://pubmed.ncbi.nlm.nih.gov/23331158/"},{"id":1800,"title":"Role of lysine during protein modification by HOCl and HOBr: halogen-transfer agent or sacrificial antioxidant?","authors":"Sivey, John D; Howell, Stanley C; Bean, Doyle J; McCurry, Daniel L; Mitch, William A; Wilson, Corey J","year":2013,"date":"2013 Feb 19","journal":"Biochemistry","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"Although protein degradation by neutrophil-derived hypochlorous acid (HOCl) and eosinophil-derived hypobromous acid (HOBr) can contribute to the inactivation of pathogens, collateral damage to host proteins can also occur and has been associated with inflammatory diseases ranging from arthritis to atherosclerosis. Though previous research suggested halotyrosines as biomarkers of protein damage and lysine as a mediator of the transfer of a halogen to tyrosine, these reactions within whole proteins are poorly understood. Herein, reactions of HOCl and HOBr with three well-characterized proteins [adenylate kinase (ADK), ribose binding protein, and bovine serum albumin] were characterized. Three assessments of oxidative modifications were evaluated for each of the proteins: (1) covalent modification of electron-rich amino acids (assessed via liquid chromatography and tandem mass spectrometry), (2) attenuation of secondary structure (via circular dichroism), and (3) fragmentation of protein backbones (via sodium dodecyl sulfate-polyacrylamide gel electrophoresis). In addition to forming halotyrosines, HOCl and HOBr converted lysine into lysine nitrile (2-amino-5-cyanopentanoic acid), a relatively stable and largely overlooked product, in yields of up to 80%. At uniform oxidant levels, fragmentation and loss of secondary structure correlated with protein size. To further examine the role of lysine, a lysine-free ADK variant was rationally designed. The absence of lysine increased yields of chlorinated tyrosines and decreased yields of brominated tyrosines following treatments with HOCl and HOBr, respectively, without influencing the susceptibility of ADK to HOX-mediated losses of secondary structure. These findings suggest that lysine serves predominantly as a sacrificial antioxidant (via formation of lysine nitrile) toward HOCl and as a halogen-transfer mediator [via reactions involving ε-N-(di)haloamines] with HOBr.","pmid":"23327477","doi":"10.1021/bi301523s","url":"https://pubmed.ncbi.nlm.nih.gov/23327477/"},{"id":1803,"title":"Antiviral activity of Ecasol against feline calicivirus, a surrogate of human norovirus.","authors":"Chander, Yogesh; Johnson, Thomas; Goyal, Sagar M; Russell, R J","year":2012,"date":"2012 Dec","journal":"Journal of infection and public health","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Human norovirus (NoV) is a major cause of acute gastroenteritis in closed settings such as hospitals, hotels and cruise ships. The virus survives on inanimate surfaces for extended periods of time, and environmental contamination has been implicated in its transmission. The disinfection of contaminated areas is important in controlling the spread of NoV infections. Neutral solutions of electrochemically activated (ECA)-anolyte have been shown to be powerful disinfectants against a broad range of bacterial pathogens. The active chemical ingredient is hypochlorous acid (HOCl), which is registered as an approved food contact surface sanitizer in the United States by the Environmental Protection Agency, pursuant to 40 CFR 180.940. We evaluated the antiviral activity of Ecasol (an ECA-anolyte) against feline calicivirus (FCV), a surrogate of NoV. FCV dried on plastic surfaces was exposed to Ecasol for 1, 2, or 5min. After exposure to Ecasol, the virus titers were compared with untreated controls to determine the virus inactivation efficacy after different contact times. Ecasol was found to decrease the FCV titer by >5log(10) within 1min of contact, indicating its suitability for inactivation of NoV on surfaces.","pmid":"23287613","doi":"10.1016/j.jiph.2012.10.001","url":"https://pubmed.ncbi.nlm.nih.gov/23287613/"},{"id":1804,"title":"Single-cell analysis of cell viability after a biocide treatment unveils an absence of positive correlation between two commonly used viability markers.","authors":"Ducret, Adrien; Dukan, Sam","year":2013,"date":"2013 Feb","journal":"MicrobiologyOpen","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Discrimination among viable/active or dead/inactive cells in a microbial community is a vital question to address issues on ecological microbiology or microbiological quality control. It is commonly assumed that metabolically active cells (ChemchromeV6 [CV6] procedure) correspond to viable cells (direct viable count procedure [DVC]), although this assumption has never been demonstrated and is therefore a matter of debate. Indeed, simultaneous determination of cell viability and metabolic activity has never been performed on the same cells. Here, we developed a microfluidic device to investigate the viability and the metabolic activity of Escherichia coli cells at single-cell level. Cells were immobilized in a flow chamber in which different solutions were sequentially injected according to different scenarios. By using time-lapse microscopy combined with automated tracking procedures, we first successfully assessed the ability of cells to divide and their metabolic activity at single-cell level. Applying these two procedures on the same cells after a hypochlorous acid (HOCl) treatment, we showed that the ability of cells to divide and their metabolic activity were anticorrelated. These results indicate that the relation between CV6 uptake and cell viability may be partially incorrect. Care must be taken in using the terms \"CV6-positive\" and \"viable\" synonymously.","pmid":"23281341","doi":"10.1002/mbo3.62","url":"https://pubmed.ncbi.nlm.nih.gov/23281341/"},{"id":1805,"title":"Active halogen compounds and proteinaceous material: loss of activity of topical anti-infectives by halogen consumption.","authors":"Gottardi, Waldemar; Nagl, Markus","year":2013,"date":"2013 Feb","journal":"The Journal of pharmacy and pharmacology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"OBJECTIVES: The activity of oxidants, such as halogens and active halogen compounds, decreases generally in the presence of proteinaceous material. A quantification of consumption effects was performed to judge the suitability of different representatives as antiseptics and their compatibility with pharmaceutical additives. METHODS: An iodometric approach served to assess the temporal loss of oxidation capacity in the presence of peptone and fetal calf serum (FCS). The tested agents comprised active halogen compounds, well-known and in particular novel chloramine-based agents indicated for the topical treatment of infections. KEY FINDINGS: The decrease in oxidation capacity was higher in the presence of FCS than of peptone and correlated with the reactivity of the oxidants in both cases. The highest consumption rates were for active bromine compounds followed by hypochlorous acid and heterocyclic chlorimides, such as dichloro-isocyanuric acid, while N-chlorotaurine and related amine-based analogues were least consumed. The pH dependence was only remarkable for chloramine T. CONCLUSIONS: The observed consumption effects are the result of the differing oxidizing (chlorinating) potencies. Since consumption and irritation are founded on the very same reactions, representatives with low reactivity (N-chloro amino acids) are regarded as more tolerable and retain more oxidative capacity, which provides a more sustained antimicrobial activity.","pmid":"23278688","doi":"10.1111/j.2042-7158.2012.01589.x","url":"https://pubmed.ncbi.nlm.nih.gov/23278688/"},{"id":1807,"title":"Formation of organochlorine by-products in bleached laundry.","authors":"Leri, Alessandra C; Anthony, Laura N","year":2013,"date":"2013 Feb","journal":"Chemosphere","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Laundering fabrics with chlorine bleach plays a role in health and hygiene as well as aesthetics. However, laundry bleaching may create chlorinated by-products with potentially adverse human health effects. Studies have shown that toxic chlorinated gases are produced in the headspace of washing machines when hypochlorite-containing bleach is used. Laundry bleaching has also been implicated in contributing dissolved organochlorine to municipal wastewater. However, there have been no reports of organochlorines produced and retained in fabric as a result of laundry bleaching. We have used a chlorine-specific X-ray spectroscopic analysis to demonstrate the formation of organochlorine by-products in cotton fabrics laundered with chlorine bleach under typical household conditions. Organochlorine formation increases at higher wash temperature. At least two pools of organochlorine are produced in bleached fabric: a labile fraction that diminishes over several months of storage time as well as a more stable fraction that persists after more than 1 year. Our results also suggest that residual hypochlorite remains in fabric after laundering with bleach, presenting the possibility of direct and sustained dermal contact with reactive chlorine. This study provides a first step toward identifying a new risk factor for elevated organochlorine body burdens in humans.","pmid":"23261123","doi":"10.1016/j.chemosphere.2012.10.088","url":"https://pubmed.ncbi.nlm.nih.gov/23261123/"},{"id":1809,"title":"Inhibition by polyphenolic phytochemicals and sulfurous compounds of the formation of 8-chloroguanosine mediated by hypochlorous acid, human myeloperoxidase, and activated human neutrophils.","authors":"Nakano, Toshiki; Masuda, Mitsuharu; Suzuki, Toshinori; Ohshima, Hiroshi","year":2012,"date":"2012","journal":"Bioscience, biotechnology, and biochemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HOCl) produced by myeloperoxidase (MPO) of activated neutrophils can react with nucleic acid bases to form chlorinated nucleosides such as 8-chloroguanosine (Cl-Guo). Chlorination is enhanced by nicotine. We investigated the effects of various natural antioxidants including polyphenolic phytochemicals on the formation of Cl-Guo by HOCl in the presence and the absence of nicotine. Polyphenols, including catechins, curcumin, resveratrol, silibinin, and sulfurous compound α-lipoic acid, were found to inhibit both HOCl- and human MPO-induced Cl-Guo formation dose-dependently. Among the test compounds, (-)-epigallocatechin gallate (EGCG) showed the strongest inhibitory effect. Cl-Guo formation, mediated by activated human neutrophils in the presence of nicotine, was inhibited by EGCG, silibinin, and α-lipoic acid. These results suggest that polyphenols and sulfurous compounds have the potential to inhibit the induction of nucleobase damage mediated by chlorination, with possible application to reducing DNA damage associated with inflammation and cigarette-smoke inhalation.","pmid":"23221717","doi":"10.1271/bbb.120482","url":"https://pubmed.ncbi.nlm.nih.gov/23221717/"},{"id":1810,"title":"Chlorination and oxidation of heparin and hyaluronan by hypochlorous acid and hypochlorite anions: effect of sulfate groups on reaction pathways and kinetics.","authors":"Akeel, Almabrok; Sibanda, Sambulelwe; Martin, Stephen W; Paterson, Andrew W J; Parsons, Barry J","year":2013,"date":"2013 Mar","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Hypochlorous acid (HOCl), produced in inflammatory conditions by the enzyme myeloperoxidase, and its anion hypochlorite (OCl(-)) exist in vivo at almost equal concentrations. Their reactions with hyaluronan and heparin (as a model for sulfated glycosaminoglycans in the extracellular matrix) have been studied as a function of pH. The major product in these reactions is the chloramide derivative of the glycosaminoglycans. Spectral, chloramide yield, and kinetic measurements show sharply contrasting behavior of heparin and hyaluronan and the data allow the calculation of second-order rate constants for the reactions of both HOCl and OCl(-) for all reaction pathways leading to the formation of chloramides and also oxidation products. By comparison with hyaluronan, it can be demonstrated that both N-sulfate and O-sulfate groups in heparin influence the proportions of these pathways in this glycosaminoglycan. Evidence is also given for further oxidation pathways involving a reaction of HOCl with the chloramide product of hyaluronan but not with heparin. The significance of these results for the mechanisms of inflammation, particularly for fragmentation of extracellular matrix glycosaminoglycans, is discussed.","pmid":"23220380","doi":"10.1016/j.freeradbiomed.2012.11.020","url":"https://pubmed.ncbi.nlm.nih.gov/23220380/"},{"id":1811,"title":"Synthesis, characterization, and reactivity of hypochloritoiron(III) porphyrin complexes.","authors":"Cong, Zhiqi; Yanagisawa, Sachiko; Kurahashi, Takuya; Ogura, Takashi; Nakashima, Satoru; Fujii, Hiroshi","year":2012,"date":"2012 Dec 26","journal":"Journal of the American Chemical Society","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"A hypochloritoiron(III) porphyrin species has been proposed as a key intermediate in an antimicrobial defense system in neutrophils and in heme-catalyzed chlorination reactions. We report herein the preparation, spectroscopic characterization, and reactivity of the bis(hypochlorito)iron(III) porphyrin complex [(TPFP)Fe(III)(OCl)(2)](-) (1) and the imidazole-hypochloritoiron complexes (TPFP)Fe(III)(OCl)(1-R-Im) [R = CH(3) (2), H (3), CH(2)CO(2)H (4)], in which TPFP is 5,10,15,20-tetrakis(pentafluorophenyl)porphyrinate. The structures of 1-4 were confirmed by absorption, (2)H and (19)F NMR, EPR, and resonance Raman spectroscopy and electrospray ionization mass spectrometry at low temperature. The reactions of 1 and 2 with various organic substrates show that 1 and 2 are capable of chlorination, sulfoxidation, and epoxidation reactions and that 1 is much more reactive with these substrates than 2.","pmid":"23214510","doi":"10.1021/ja3108774","url":"https://pubmed.ncbi.nlm.nih.gov/23214510/"},{"id":1814,"title":"A simple yet effective chromogenic reagent for the rapid estimation of bromate and hypochlorite in drinking water.","authors":"Zhang, Jia; Yang, Xiurong","year":2013,"date":"2013 Jan 21","journal":"The Analyst","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"We present a method for the rapid visible assay of bromate and hypochlorite in drinking water within 5 min. The assay utilizes a commercially common reagent and allows the determination of bromate and hypochlorite at several ppb levels with remarkably high selectivity over other ions.","pmid":"23175696","doi":"10.1039/c2an36287b","url":"https://pubmed.ncbi.nlm.nih.gov/23175696/"},{"id":1817,"title":"Free chlorine inactivation of fungi in drinking water sources.","authors":"Pereira, V J; Marques, R; Marques, M; Benoliel, M J; Barreto Crespo, M T","year":2013,"date":"2013 Feb 1","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The effectiveness of free chlorine for the inactivation of fungi present in settled surface water was tested. In addition, free chlorine inactivation rate constants of Cladosporium tenuissimum, Cladosporium cladosporioides, Phoma glomerata, Aspergillus terreus, Aspergillus fumigatus, Penicillium griseofulvum, and Penicillium citrinum that were found to occur in different source waters were determined in different water matrices (laboratory grade water and settled water). The effect of using different disinfectant concentrations (1 and 3 mg/l), temperatures (21 and 4 °C), and pH levels (6 and 7) was addressed. The sensitivity degree of different fungi isolates to chlorine disinfection varied among different genera with some species showing a higher resistance to disinfection and others expected to be more prone to protection from inactivation by the water matrix components. When the disinfection efficiency measured in terms of the chlorine concentration and contact time (Ct) values needed to achieve 99% inactivation were compared with the Ct values reported as being able to achieve the same degree of inactivation of other microorganisms, fungi were found to be more resistant to chlorine inactivation than bacteria and viruses and less resistant than Cryptosporidium oocysts.","pmid":"23164218","doi":"10.1016/j.watres.2012.09.052","url":"https://pubmed.ncbi.nlm.nih.gov/23164218/"},{"id":1818,"title":"Reactions of copper macrocycles with antioxidants and HOCl: potential for biological redox sensing.","authors":"Sowden, Rebecca J; Trotter, Katherine D; Dunbar, Lynsey; Craig, Gemma; Erdemli, Omer; Spickett, Corinne M; Reglinski, John","year":2013,"date":"2013 Feb","journal":"Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"A series of simple copper N(2)S(2) macrocycles were examined for their potential as biological redox sensors, following previous characterization of their redox potentials and crystal structures. The divalent species were reduced by glutathione or ascorbate at a biologically relevant pH in aqueous buffer. A less efficient reduction was also achieved by vitamin E in DMSO. Oxidation of the corresponding univalent copper species by sodium hypochlorite resulted in only partial (~65 %) recovery of the divalent form. This was concluded to be due to competition between metal oxidation and ligand oxidation, which is believed to contribute to macrocycle demetallation. Electrospray mass spectrometry confirmed that ligand oxidation had occurred. Moreover, the macrocyclic complexes could be demetallated by incubation with EDTA and bovine serum albumin, demonstrating that they would be inappropriate for use in biological systems. The susceptibility to oxidation and demetallation was hypothesized to be due to oxidation of the secondary amines. Consequently these were modified to incorporate additional oxygen donor atoms. This modification led to greater resistance to demetallation and ligand oxidation, providing a better platform for further development of copper macrocycles as redox sensors for use in biological systems.","pmid":"23160798","doi":"10.1007/s10534-012-9596-9","url":"https://pubmed.ncbi.nlm.nih.gov/23160798/"},{"id":1819,"title":"Evaluation of antioxidant activity of leafy vegetables and beans with myoglobin method.","authors":"Terashima, Masaaki; Fukukita, Akiko; Kodama, Riho; Miki, Haruka; Suzuki, Mayuko; Ikegami, Maya; Tamura, Noriko; Yasuda, Akari; Morikawa, Mami; Matsumura, Saki","year":2013,"date":"2013 Mar","journal":"Plant cell reports","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"KEY MESSAGE : Antioxidant activity of seven leafy vegetables and four beans against five reactive oxygen species and reactive nitrogen species was clearly characterized with a protocol using myoglobin as a reporter probe. Antioxidant activity of seven leafy vegetables and four beans against peroxyl radical, hydroxyl radical, hypochlorite ion, and peroxynitrite ion has been measured using myoglobin as a reporter probe (myoglobin method). Conventional DPPH method was also used to evaluate antioxidant activity of the samples. Difference of activity against different reactive oxygen species (ROS) and reactive nitrogen species (RNS) was characterized by plotting the data in a 5-axe cobweb chart. This plot clearly showed the characteristics of the antioxidant activity of the leafy vegetables and the beans. The samples examined in this work were categorized into four groups. (1) The samples showed high antioxidant activity against all ROS and RNS: daikon sprout, spinach, Qing-geng-cai, and onion. (2) The samples showed high antioxidant activity against peroxyl radical: red bean and soy bean. (3) The samples showed high antioxidant against hypochlorite ion: broccoli floret, cabbage, and Chinese cabbage. (4) The samples showed weak antioxidant activity against all ROS and RNS: cowpea and common beans. Our protocol is probably useful to characterize antioxidant activity of the crops of different cultivars, the crops obtained in different growing environments and growing seasons, the crops harvested at different age, and the crops stored in the different conditions, as well as the changes of activity during cooking process of the crops.","pmid":"23160640","doi":"10.1007/s00299-012-1368-z","url":"https://pubmed.ncbi.nlm.nih.gov/23160640/"},{"id":1821,"title":"DNA of Dientamoeba fragilis detected within surface-sterilized eggs of Enterobius vermicularis.","authors":"Röser, Dennis; Nejsum, Peter; Carlsgart, Anne Josefine; Nielsen, Henrik Vedel; Stensvold, Christen Rune","year":2013,"date":"2013 Jan","journal":"Experimental parasitology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"With no evidence of a cyst stage, the mode of transmission of Dientamoeba fragilis, an intestinal protozoon of common occurrence and suggested pathogenicity, is incompletely known. Numerous studies have suggested that eggs of intestinal nematodes, primarily Enterobius vermicularis (pinworm), can serve as vectors for D. fragilis, although attempts to culture D. fragilis from pinworm eggs have been unsuccessful and data from epidemiological studies on D. fragilis/pinworm co-infection have been conflicting. The aim of this study was to investigate whether we could detect D. fragilis DNA from pinworm eggs collected from routine diagnostic samples (cellophane tape) and surface-sterilised by hypochlorite. DNA was extracted from individual eggs and tested by PCR using D. fragilis- and E. vermicularis-specific primers; amplicons were sequenced for confirmation. In cellophane tape samples from 64 patients with unknown D. fragilis status we detected D. fragilis DNA in 12/238 (5%) eggs, and in a patient known to harbour D. fragilis we detected D. fragilis DNA in 39/99 (39%) eggs. The finding of D. fragilis DNA within eggs of E. vermicularis strongly supports the hypothesis of D. fragilis-transmission by pinworm and has implications for antimicrobial intervention as well as control and public health measures.","pmid":"23116599","doi":"10.1016/j.exppara.2012.10.009","url":"https://pubmed.ncbi.nlm.nih.gov/23116599/"},{"id":1824,"title":"Virus inactivation mechanisms: impact of disinfectants on virus function and structural integrity.","authors":"Wigginton, Krista Rule; Pecson, Brian M; Sigstam, Thérese; Bosshard, Franziska; Kohn, Tamar","year":2012,"date":"2012 Nov 6","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Oxidative processes are often harnessed as tools for pathogen disinfection. Although the pathways responsible for bacterial inactivation with various biocides are fairly well understood, virus inactivation mechanisms are often contradictory or equivocal. In this study, we provide a quantitative analysis of the total damage incurred by a model virus (bacteriophage MS2) upon inactivation induced by five common virucidal agents (heat, UV, hypochlorous acid, singlet oxygen, and chlorine dioxide). Each treatment targets one or more virus functions to achieve inactivation: UV, singlet oxygen, and hypochlorous acid treatments generally render the genome nonreplicable, whereas chlorine dioxide and heat inhibit host-cell recognition/binding. Using a combination of quantitative analytical tools, we identified unique patterns of molecular level modifications in the virus proteins or genome that lead to the inhibition of these functions and eventually inactivation. UV and chlorine treatments, for example, cause site-specific capsid protein backbone cleavage that inhibits viral genome injection into the host cell. Combined, these results will aid in developing better methods for combating waterborne and foodborne viral pathogens and further our understanding of the adaptive changes viruses undergo in response to natural and anthropogenic stressors.","pmid":"23098102","doi":"10.1021/es3029473","url":"https://pubmed.ncbi.nlm.nih.gov/23098102/"},{"id":1825,"title":"Chloride transport in functionally active phagosomes isolated from Human neutrophils.","authors":"Aiken, Martha L; Painter, Richard G; Zhou, Yun; Wang, Guoshun","year":2012,"date":"2012 Dec 15","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Chloride anion is critical for hypochlorous acid (HOCl) production and microbial killing in neutrophil phagosomes. However, the molecular mechanism by which this anion is transported to the organelle is poorly understood. In this report, membrane-enclosed and functionally active phagosomes were isolated from human neutrophils by using opsonized paramagnetic latex microspheres and a rapid magnetic separation method. The phagosomes recovered were highly enriched for specific protein markers associated with this organelle such as lysosomal-associated membrane protein-1, myeloperoxidase (MPO), lactoferrin, and NADPH oxidase. When FITC-dextran was included in the phagocytosis medium, the majority of the isolated phagosomes retained the fluorescent label after isolation, indicative of intact membrane structure. Flow cytometric measurement of acridine orange, a fluorescent pH indicator, in the purified phagosomes demonstrated that the organelle in its isolated state was capable of transporting protons to the phagosomal lumen via the vacuolar-type ATPase proton pump (V-ATPase). When NADPH was supplied, the isolated phagosomes constitutively oxidized dihydrorhodamine 123, indicating their ability to produce hydrogen peroxide. The preparations also showed a robust production of HOCl within the phagosomal lumen when assayed with the HOCl-specific fluorescent probe R19-S by flow cytometry. MPO-mediated iodination of the proteins covalently conjugated to the phagocytosed beads was quantitatively measured. Phagosomal uptake of iodide and protein iodination were significantly blocked by chloride channel inhibitors, including CFTRinh-172 and NPPB. Further experiments determined that the V-ATPase-driving proton flux into the isolated phagosomes required chloride cotransport, and the cAMP-activated CFTR chloride channel was a major contributor to the chloride transport. Taken together, the data suggest that the phagosomal preparation described herein retains ion transport properties, and multiple chloride channels including CFTR are responsible for chloride supply to neutrophil phagosomes.","pmid":"23089227","doi":"10.1016/j.freeradbiomed.2012.10.542","url":"https://pubmed.ncbi.nlm.nih.gov/23089227/"},{"id":1828,"title":"Preventing protein oxidation with sugars: scavenging of hypohalous acids by 5-selenopyranose and 4-selenofuranose derivatives.","authors":"Storkey, Corin; Pattison, David I; White, Jonathan M; Schiesser, Carl H; Davies, Michael J","year":2012,"date":"2012 Nov 19","journal":"Chemical research in toxicology","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Heme peroxidases including myeloperoxidase (MPO) are released at sites of inflammation by activated leukocytes. MPO generates hypohalous acids (HOX, X = Cl, Br, SCN) from H(2)O(2); these oxidants are bactericidal and are key components of the inflammatory response. However, excessive, misplaced or mistimed production can result in host tissue damage, with this implicated in multiple inflammatory diseases. We report here methods for the conversion of simple monosaccharide sugars into selenium- and sulfur-containing species that may act as potent water-soluble scavengers of HOX. Competition kinetic studies show that the seleno species react with HOCl with rate constants in the range 0.8-1.0 × 10(8) M(-1) s(-1), only marginally slower than those for the most susceptible biological targets including the endogenous antioxidant, glutathione. The rate constants for the corresponding sulfur-sugars are considerably slower (1.4-1.9 × 10(6) M(-1) s(-1)). Rate constants for reaction of the seleno-sugars with HOBr are ~8 times lower than those for HOCl (1.0-1.5 × 10(7) M(-1) s(-1)). These values show little variation with differing sugar structures. Reaction with HOSCN is slower (~10(2) M(-1) s(-1)). The seleno-sugars decreased the extent of HOCl-mediated oxidation of Met, His, Trp, Lys, and Tyr residues, and 3-chlorotyrosine formation, on both isolated bovine serum albumin and human plasma proteins, at concentrations as low as 50 μM. These studies demonstrate that novel selenium (and to a lesser extent, sulfur) derivatives of monosaccharides could be potent modulators of peroxidase-mediated damage at sites of acute and chronic inflammation, and in multiple human pathologies.","pmid":"23075063","doi":"10.1021/tx3003593","url":"https://pubmed.ncbi.nlm.nih.gov/23075063/"},{"id":1830,"title":"Targeted subendothelial matrix oxidation by myeloperoxidase triggers myosin II-dependent de-adhesion and alters signaling in endothelial cells.","authors":"Rees, Martin D; Dang, Lei; Thai, Thuan; Owen, Dylan M; Malle, Ernst; Thomas, Shane R","year":2012,"date":"2012 Dec 15","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"During inflammation, myeloperoxidase (MPO) released by circulating leukocytes accumulates within the subendothelial matrix by binding to and transcytosing the vascular endothelium. Oxidative reactions catalyzed by subendothelial-localized MPO are implicated as a cause of endothelial dysfunction in vascular disease. While the subendothelial matrix is a key target for MPO-derived oxidants during disease, the implications of this damage for endothelial morphology and signaling are largely unknown. We found that endothelial-transcytosed MPO produced hypochlorous acid (HOCl) that reacted locally with the subendothelial matrix and induced covalent cross-linking of the adhesive matrix protein fibronectin. Real-time biosensor and live cell imaging studies revealed that HOCl-mediated matrix oxidation triggered rapid membrane retraction from the substratum and adjacent cells (de-adhesion). De-adhesion was linked with the alteration of Tyr-118 phosphorylation of paxillin, a key adhesion-dependent signaling process, as well as Rho kinase-dependent myosin light chain-2 phosphorylation. De-adhesion dynamics were dependent on the contractile state of cells, with myosin II inhibition with blebbistatin attenuating the rate of membrane retraction. Rho kinase inhibition with Y-27632 also conferred protection, but not during the initial phase of membrane retraction, which was driven by pre-existing actomyosin tensile stress. Notably, diversion of MPO from HOCl production by thiocyanate or nitrite attenuated de-adhesion and associated signaling responses, despite the latter substrate supporting MPO-catalyzed fibronectin nitration. These data show that subendothelial-localized MPO employs a novel \"outside-in\" mode of redox signaling, involving HOCl-mediated matrix oxidation. These MPO-catalyzed oxidative events are likely to play a previously unrecognized role in altering endothelial integrity and signaling during inflammatory vascular disorders.","pmid":"23059132","doi":"10.1016/j.freeradbiomed.2012.10.002","url":"https://pubmed.ncbi.nlm.nih.gov/23059132/"},{"id":1831,"title":"Resorcinol as a spectrofluorometric probe for the hypochlorous acid scavenging activity assay of biological samples.","authors":"Özyürek, Mustafa; Bekdeşer, Burcu; Güçlü, Kubilay; Apak, Reşat","year":2012,"date":"2012 Nov 6","journal":"Analytical chemistry","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"A novel spectrofluorometric method was developed and validated for hypochlorous acid (HOCl) scavenging activity estimation using resorcinol, which is a highly sensitive and chemically stable fluorogenic probe. This assay is based on the chlorination of resorcinol to its nonfluorescent products in the presence of HOCl. HOCl reacts with both resorcinol and HOCl scavengers incubated in solution for 10 min, where scavengers compete with resorcinol for the HOCl. Thus, the relative increase in fluorescence intensity of intact resorcinol is proportional to the antioxidative activity of HOCl scavengers. Using this reaction, a kinetic approach was adopted to assess the HOCl scavenging activity of amino acids, vitamins, and plasma and thiol antioxidants. This assay, which is applicable to small molecule antioxidants and tissue homogenates, proved to be efficient for thiol-type antioxidants for which the widely used 5-thio-2-nitrobenzoic acid (TNB) test is not accurately responsive. Thus, conventional problems of the TNB assay arising from the reactivity of thiol-type scavengers to produce extra TNB by direct reduction of 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) were overcome. Moreover, unlike enzymatic assays (e.g., elastase), there is no confusion as to whether the putative scavenger actually reacts with HOCl or inhibits the enzyme.","pmid":"23046424","doi":"10.1021/ac302369p","url":"https://pubmed.ncbi.nlm.nih.gov/23046424/"},{"id":1833,"title":"Presence of hydrogen peroxide, a source of hydroxyl radicals, in acid electrolyzed water.","authors":"Mokudai, Takayuki; Nakamura, Keisuke; Kanno, Taro; Niwano, Yoshimi","year":2012,"date":"2012","journal":"PloS one","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"BACKGROUND: Acid electrolyzed water (AEW), which is produced through the electrolysis of dilute sodium chloride (NaCl) or potassium chloride solution, is used as a disinfectant in various fields because of its potent antimicrobial activity. The hydroxyl radical, an oxygen radical species, is often suggested as a putative active ingredient for AEW antimicrobial activity. METHODOLOGY/PRINCIPAL FINDINGS: The aim of the present study is to detect hydroxyl radicals in AEW. The hydroxyl radicals in AEW prepared under different conditions were determined using an electron spin resonance (ESR) technique. A signal from 5,5-dimethyl-1-pyrroline N-oxide (DMPO)-OH, an adduct of DMPO and the hydroxyl radical, was detected in AEW prepared by double or triple electrolyses of 1% NaCl but not of 0.1% NaCl solution. Then the presence of hydrogen peroxide as a proposed source of hydroxyl radicals was examined using a combination of ESR and a Fenton reaction. The DMPO-OH signal was clearly detected, even in AEW prepared by single electrolysis of 0.1% NaCl solution, when ferrous sulfate was added to induce a Fenton reaction, indicating the presence of hydrogen peroxide in the AEW. Since sodium formate, a hydroxyl radical scavenger, did not affect the bactericidal activity of AEW, it is concluded that the radical is unlikely to contribute to the antimicrobial activity of AEW, although a small amount of the radical is produced from hydrogen peroxide. Dimethyl sulfoxide, the other hydroxyl radical scavenger used in the present study, canceled the bactericidal activity of AEW, accompanied by complete depletion of free available chlorine, suggesting that hypochlorous acid is probably a major contributor to the antimicrobial activity. CONCLUSIONS: It is strongly suggested that although hydrogen peroxide is present in AEW as a source of hydroxyl radicals, the antimicrobial activity of AEW does not depend on these radicals.","pmid":"23029505","doi":"10.1371/journal.pone.0046392","url":"https://pubmed.ncbi.nlm.nih.gov/23029505/"},{"id":1834,"title":"Sensitive and simple determination of bromate in foods disinfected with hypochlorite reagents using high performance liquid chromatography with post-column derivatization.","authors":"Yokota, Azusa; Kubota, Hiroki; Komiya, Satomi; Sato, Kyoko; Akiyama, Hiroshi; Koshiishi, Ichiro","year":2012,"date":"2012 Nov 2","journal":"Journal of chromatography. A","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"A novel analytical method for the quantification of bromate in fresh foods using high performance liquid chromatography (HPLC) with a post-column reaction has been developed. The fresh food sample solutions were pretreated with homogenization, centrifugal ultrafiltration and subsequent solid phase extraction using a strong anion-exchange resin. After separation on a strong anion-exchange chromatography column using a highly concentrated NaCl solution (0.3M) as the eluent, the bromate was quantified by detection using a post-column reaction with a non-carcinogenic reagent (tetramethylbenzidine). The developed HPLC technique made it possible to quantify bromate in salt-rich fresh foods. The recoveries from fresh foods spiked with bromate at low levels (2 or 10 ng/g) satisfactorily ranged from 75.3 to 90.7%. The lowest quantification limit in fresh foods was estimated to be 0.6 ng/g as bromic acid. The method should be helpful for the quantification of bromate in fresh foods disinfected with hypochlorite solutions.","pmid":"23026260","doi":"10.1016/j.chroma.2012.09.014","url":"https://pubmed.ncbi.nlm.nih.gov/23026260/"},{"id":1835,"title":"Microbicidal effect of weak acid hypochlorous solution on various microorganisms.","authors":"Ono, Tomoko; Yamashita, Koji; Murayama, Tomomi; Sato, Toshio","year":2012,"date":"2012","journal":"Biocontrol science","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"We investigated the microbicidal effect of weak acid hypochlorous solutions of pH 5.0 - 6.0, produced by mixing NaClO and HCl in water, against various bacteria, fungi, and virus in vitro. The weak acid hypochlorous solution had excellent microbicidal effect against a broad microbicidal spectrum of standard strains and clinical isolates in a short time. The microbicidal effects of hypochlorous solutions did not depend on the available chlorine concentration but on the HClO concentration. These results show that the weak acid hypochlorous solution has practical applicability in such places as hospitals and establishments related to the food industry.","pmid":"23007104","doi":"10.4265/bio.17.129","url":"https://pubmed.ncbi.nlm.nih.gov/23007104/"},{"id":1838,"title":"Antioxidant characteristics of extracts from cereal residues by their subcritical water treatment.","authors":"Murayama, Yusuke; Wiboonsirikul, Jintana; Khuwijitjaru, Pramote; Kobayashi, Takashi; Adachi, Shuji","year":2012,"date":"2012","journal":"Journal of oleo science","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Subcritical water treatment of cereal residues including okara, defatted rice bran, desalted soy sauce lees, sake lees, corn kernel hull, and defatted rapeseed was conducted at 260°C for 5 min to obtain the antioxidative extracts. The antioxidative activities of the extracts were evaluated using DPPH radical, peroxyl radical, hydroxyl radical, hypochlorite ion, and peroxynitrite ion. The results show that the extracts from the sake lees, corn kernel hull, and defatted rapeseed had differently the antioxidative activities against all radicals and ions. However, the okara, defatted rice bran and desalted soy sauce lees had no activity against the hypochlorite ion.","pmid":"22975779","doi":"10.5650/jos.61.465","url":"https://pubmed.ncbi.nlm.nih.gov/22975779/"},{"id":1839,"title":"Ginsenoside Rb1 directly scavenges hydroxyl radical and hypochlorous acid.","authors":"Lü, Jian-Ming; Weakley, Sarah M; Yang, Zhen; Hu, Ming; Yao, Qizhi; Chen, Changyi","year":2012,"date":"2012","journal":"Current pharmaceutical design","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Reactive oxygen species (ROS) have been implicated in a variety of inflammatory diseases including cardiovascular disease (CVD), cancer, diabetes, Alzheimer's disease, autism, cataracts and aging. When endogenous mechanisms for the maintenance of redox homeostasis are overwhelmed, dietary intake of antioxidants contributes substantially to balancing the body's oxidant/antioxidant status. Ginsenosides are thought to be primarily responsible for the pharmacological effect of P. ginseng root extracts on oxidative stress and inflammation. However, little is known about the underlying antioxidant mechanisms of individual ginsenoside; specifically, the reactivity of ginsenoside Rb1 with ROS has not been well studied. We found that Rb1 can significantly and selectively reduce hydroxyl radical (●OH) and hypochlorous acid (HOCl), two of the strongest ROS, with unique molecular mechanisms in a cell-free system. Rb1 directly scavenges the ●OH and protects plasmid DNA from damage induced by ●OH. ●OH likely attacks the double bond on the side chain of Rb1 as well as hydrogen atoms adjacent to the -OH groups, including those of sugar moieties. Rb1 also shows a high reactivity to HOCl and effectively inhibits HOCl-induced tyrosine chlorination in a cell free system. HOCl is added to the double bond of Rb1; the -Cl group and -OH group of HOCl possibly bond at C-24 and C-25 of Rb1 based on the regioselectivity of Markovnikov's Rule. To our knowledge, this is the first demonstration that ginsenoside Rb1 scavenges HOCl and protects tyrosine from HOCl-induced chlorination. Thus, this study reveals unique antioxidant mechanisms of individual ginsenoside Rb1, which may contribute to the pharmacological effect of P. ginseng and to the development of effective strategies for clinical applications of ginsenosides.","pmid":"22974003","doi":"10.2174/138161212803832254","url":"https://pubmed.ncbi.nlm.nih.gov/22974003/"},{"id":1840,"title":"Enhanced bromate formation during chlorination of bromide-containing waters in the presence of CuO: catalytic disproportionation of hypobromous acid.","authors":"Liu, Chao; von Gunten, Urs; Croué, Jean-Philippe","year":2012,"date":"2012 Oct 16","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Bromate (BrO(3)(-)) in drinking water is traditionally seen as an ozonation byproduct from the oxidation of bromide (Br(-)), and its formation during chlorination is usually not significant. This study shows enhanced bromate formation during chlorination of bromide-containing waters in the presence of cupric oxide (CuO). CuO was effective to catalyze hypochlorous acid (HOCl) or hypobromous acid (HOBr) decay (e.g., at least 10(4) times enhancement for HOBr at pH 8.6 by 0.2 g L(-1) CuO). Significant halate concentrations were formed from a CuO-catalyzed hypohalite disproportionation pathway. For example, the chlorate concentration was 2.7 ± 0.2 μM (225.5 ± 16.7 μg L(-1)) after 90 min for HOCl (C(o) = 37 μM, 2.6 mg L(-1) Cl(2)) in the presence of 0.2 g L(-1) CuO at pH 7.6, and the bromate concentration was 6.6 ± 0.5 μM (844.8 ± 64 μg L(-1)) after 180 min for HOBr (C(o) = 35 μM) in the presence of 0.2 g L(-1) CuO at pH 8.6. The maximum halate formation was at pHs 7.6 and 8.6 for HOCl or HOBr, respectively, which are close to their corresponding pK(a) values. In a HOCl-Br(-)-CuO system, BrO(3)(-) formation increases with increasing CuO doses and initial HOCl and Br(-) concentrations. A molar conversion (Br(-) to BrO(3)(-)) of up to (90 ± 1)% could be achieved in the HOCl-Br(-)-CuO system because of recycling of Br(-) to HOBr by HOCl, whereas the maximum BrO(3)(-) yield in HOBr-CuO is only 26%. Bromate formation is initiated by the formation of a complex between CuO and HOBr/OBr(-), which then reacts with HOBr to generate bromite. Bromite is further oxidized to BrO(3)(-) by a second CuO-catalyzed process. These novel findings may have implications for bromate formation during chlorination of bromide-containing drinking waters in copper pipes.","pmid":"22963047","doi":"10.1021/es3021793","url":"https://pubmed.ncbi.nlm.nih.gov/22963047/"},{"id":1843,"title":"Semicarbazide in selected bird's nest products.","authors":"Xing, Yuan-Na; Ni, Hong-Gang; Chen, Ze-Yong","year":2012,"date":"2012 Sep","journal":"Journal of food protection","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Currently, a number of food producers use hypochlorite to bleach food and inhibit the growth of bacteria, preserving the food. Because the presence of high amounts of nitrogen could result in the formation of semicarbazide (SEM), the bleaching process could be one of the predominant sources of SEM in food. To investigate this, we selected instant bottled bird's nest as an example of a food that is bleached in its production. SEM was detected in 27 of 28 instant bottled bird's nest samples. The levels of SEM detected mostly fell in the range of 5 to 50 μg/kg, which accounted for 75% of all samples measured. The SEM detected in the instant bottled bird's nest was found to have originated neither from the use of the antimicrobial agent nitrofurazone nor from azodicarbonamide, which is used as a blowing agent in gaskets used to seal the metal lid of the bottle. Instead, it could have originated from the bleaching process used in the preparation of the nests. Additionally, human exposure to SEM via consumption of instant bottled bird's nest for five subgroups of the population was estimated. Sensitivity analysis suggested that concentration of SEM in food is the most significant parameter governing human exposure via consumption of SEM-containing food.","pmid":"22947474","doi":"10.4315/0362-028X.12-065","url":"https://pubmed.ncbi.nlm.nih.gov/22947474/"},{"id":1844,"title":"A solar-driven UV/Chlorine advanced oxidation process.","authors":"Chan, Po Yee; Gamal El-Din, Mohamed; Bolton, James R","year":2012,"date":"2012 Nov 1","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"An overlap of the absorption spectrum of the hypochlorite ion (OCl(-)) and the ultraviolet (UV) end of the solar emission spectrum implies that solar photons can probably initiate the UV/chlorine advanced oxidation process (AOP). The application of this solar process to water and wastewater treatment has been investigated in this study. At the bench-scale, the OCl(-) photolysis quantum yield at 303 nm (representative of the lower end of the solar UV region) and at concentrations from 0 to 4.23 mM was 0.87 ± 0.01. Also the hydroxyl radical yield factor (for an OCl(-) concentration of 1.13 mM) was 0.70 ± 0.02. Application of this process, at the bench-scale and under actual sunlight, led to methylene blue (MB) photobleaching and cyclohexanoic acid (CHA) photodegradation. For MB photobleaching, the OCl(-) concentration was the key factor causing an increase in the pseudo first-order rate constants. The MB photobleaching quantum yield was affected by the MB concentration, but not much by the OCl(-) concentration. For CHA photodegradation, an optimal OCl(-) concentration of 1.55 mM was obtained for a 0.23 mM CHA concentration, and a scavenger effect was observed when higher OCl(-) concentrations were applied. Quantum yields of 0.09 ± 0.01 and 0.89 ± 0.06 were found for CHA photodegradation and OCl(-) photolysis, respectively. In addition, based on the Air Mass 1.5 reference solar spectrum and experimental quantum yields, a theoretical calculation method was developed to estimate the initial rate for photoreactions under sunlight. The theoretical initial rates agreed well with the experimental rates for both MB photobleaching and CHA photodegradation.","pmid":"22939221","doi":"10.1016/j.watres.2012.07.047","url":"https://pubmed.ncbi.nlm.nih.gov/22939221/"},{"id":1849,"title":"Influences of chloride and hypochlorite on neutrophil extracellular trap formation.","authors":"Akong-Moore, Kathryn; Chow, Ohn A; von Köckritz-Blickwede, Maren; Nizet, Victor","year":2012,"date":"2012","journal":"PloS one","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: The release by neutrophils of DNA-based extracellular traps (NETs) is a recently recognized innate immune phenomenon that contributes significantly to control of bacterial pathogens at tissue foci of infection. NETs have also been implicated in the pathogenesis of non-infectious diseases such as small vessel vasculitis, lupus and cystic fibrosis lung disease. Reactive oxygen species (ROS) are important mediators of NET generation (NETosis). Neutrophils with reduced ROS production, such as those from patients with chronic granulomatous disease or myeloperoxidase (MPO) deficiency, produce fewer NETs in response to inflammatory stimuli. To better understand the roles of various ROS in NETosis, we explore the role of MPO, its substrates chloride ion (Cl(-)) and hydrogen peroxide (H(2)O(2)), and its product hypochlorite (HOCl) in NETosis. FINDINGS: In human peripheral blood neutrophils, pharmacologic inhibition of MPO decreased NETosis. Absence of extracellular Cl(-), a substrate for MPO, also reduced NETosis. While exogenous addition of H(2)O(2) and HOCl stimulated NETosis, only exogenous HOCl could rescue NETosis in the setting of MPO inhibition. Neither pharmacological inhibition nor genetic deletion of MPO in murine neutrophils blocked NETosis, in contrast to findings in human neutrophils. CONCLUSIONS: Our results pinpoint HOCl as the key ROS involved in human NETosis. This finding has implications for understanding innate immune function in diseases in which Cl(-) homeostasis is disturbed, such as cystic fibrosis. Our results also reveal an example of significant species-specific differences in NET phenotypes, and the need for caution in extrapolation to humans from studies of murine NETosis.","pmid":"22912772","doi":"10.1371/journal.pone.0042984","url":"https://pubmed.ncbi.nlm.nih.gov/22912772/"},{"id":1851,"title":"PEGylated single-walled carbon nanotubes activate neutrophils to increase production of hypochlorous acid, the oxidant capable of degrading nanotubes.","authors":"Vlasova, Irina I; Vakhrusheva, Tatyana V; Sokolov, Alexey V; Kostevich, Valeria A; Gusev, Alexandr A; Gusev, Sergey A; Melnikova, Viktoriya I; Lobach, Anatolii S","year":2012,"date":"2012 Oct 1","journal":"Toxicology and applied pharmacology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Perspectives for the use of carbon nanotubes in biomedical applications depend largely on their ability to degrade in the body into products that can be easily cleared out. Carboxylated single-walled carbon nanotubes (c-SWCNTs) were shown to be degraded by oxidants generated by peroxidases in the presence of hydrogen peroxide. In the present study we demonstrated that conjugation of poly(ethylene glycol) (PEG) to c-SWCNTs does not interfere with their degradation by peroxidase/H(2)O(2) system or by hypochlorite. Comparison of different heme-containing proteins for their ability to degrade PEG-SWCNTs has led us to conclude that the myeloperoxidase (MPO) product hypochlorous acid (HOCl) is the major oxidant that may be responsible for biodegradation of PEG-SWCNTs in vivo. MPO is secreted mainly by neutrophils upon activation. We hypothesize that SWCNTs may enhance neutrophil activation and therefore stimulate their own biodegradation due to MPO-generated HOCl. PEG-SWCNTs at concentrations similar to those commonly used in in vivo studies were found to activate isolated human neutrophils to produce HOCl. Both PEG-SWCNTs and c-SWCNTs enhanced HOCl generation from isolated neutrophils upon serum-opsonized zymosan stimulation. Both types of nanotubes were also found to activate neutrophils in whole blood samples. Intraperitoneal injection of a low dose of PEG-SWCNTs into mice induced an increase in percentage of circulating neutrophils and activation of neutrophils and macrophages in the peritoneal cavity, suggesting the evolution of an inflammatory response. Activated neutrophils can produce high local concentrations of HOCl, thereby creating the conditions favorable for degradation of the nanotubes.","pmid":"22884993","doi":"10.1016/j.taap.2012.07.027","url":"https://pubmed.ncbi.nlm.nih.gov/22884993/"},{"id":1853,"title":"Effect of chlorination condition and permeability of chlorine species on the chlorination of a polyamide membrane.","authors":"Gu, Joung-Eun; Jun, Byung-Moon; Kwon, Young-Nam","year":2012,"date":"2012 Oct 15","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Most studies on membrane chlorination have been investigated in an unpressurized chlorination mode, even if the polyamide membrane was continuously exposed to chlorine under high operating pressure in real water/wastewater treatment plants. In this study, performance changes due to polyamide membrane chlorination were investigated in both pressurized and unpressurized chlorination modes. Chlorination in an unpressurized mode showed a flux increase at high pH and a flux decline at low pH due to the compaction and swelling of the polyamide chains, respectively. On the other hand, chlorination performed in a pressurized mode decreased the water flux in both acidic and alkaline conditions, showing that compaction is overwhelming compared to swelling. The permeability of HOCl, a dominant species at low pH, through the polyamide membrane was pH independent and almost similar to the system recovery, but the permeability of OCl(-), which is dominant at high pH, was maxima at a neutral pH. The different performance behaviors of membranes chlorinated at various pH conditions in the presence or absence of applied pressure could be explained by the permeability of chlorine species and compaction/swelling of polymer chains after chlorination. The effect of membrane chlorination on the chemical property changes at the two different modes was confirmed using attenuated total reflection Fourier transform infrared analysis, and a conceptual model of performance change was proposed to explain the performance discrepancy between the two chlorination modes.","pmid":"22877880","doi":"10.1016/j.watres.2012.07.030","url":"https://pubmed.ncbi.nlm.nih.gov/22877880/"},{"id":1855,"title":"A study for biofilm removing and antimicrobial effects by microbubbled tap water and other functional water, electrolyzed hypochlorite water and ozonated water.","authors":"Ozaki, Miwa; Ohshima, Tomoko; Mukumoto, Mio; Konishi, Hirokazu; Hirashita, Ayao; Maeda, Nobuko; Nakamura, Yoshiki","year":2012,"date":"2012","journal":"Dental materials journal","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The purpose of this study was to examine the biofilm removing and antimicrobial effects of microbubbled tap water and other functional water. The biofilm removal test showed that the activity of microbubbled tap water against the biofilm of Candida albicans and Streptococcus mutans was significantly higher than that of ordinary tap water (p<0.01). When the antimicrobial activities of two types of functional water were compared, the activity of electrolyzed hypochlorite water was significantly stronger than that of the ozonated water (p<0.01). The antimicrobial effect of the electrolyzed hypochlorite water was increased in the microbubbled form, and was stronger than microbubbled tap water. The same results were obtained not only for biofilms, but also for planktonic microbes. Our results demonstrated that the microbubbled water showed strong biofilm removing effects. Moreover, the application of functional water, such as electrolyzed hypochlorite microbubbled water was effective for both removing and sterilizing biofilms.","pmid":"22864222","doi":"10.4012/dmj.2012-042","url":"https://pubmed.ncbi.nlm.nih.gov/22864222/"},{"id":1856,"title":"Isoniazid as a substrate and inhibitor of myeloperoxidase: identification of amine adducts and the influence of superoxide dismutase on their formation.","authors":"Forbes, Louisa V; Furtmüller, Paul G; Khalilova, Irada; Turner, Rufus; Obinger, Christian; Kettle, Anthony J","year":2012,"date":"2012 Oct 1","journal":"Biochemical pharmacology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Neutrophils ingest Mycobacteria tuberculosis (Mtb) in the lungs of infected individuals. During phagocytosis they use myeloperoxidase (MPO) to catalyze production of hypochlorous acid (HOCl), their most potent antimicrobial agent. Isoniazid (INH), the foremost antibiotic in the treatment of tuberculosis, is oxidized by MPO. It rapidly reduced compound I of MPO [k = (1.22 ± 0.05) × 10(6) M(-1) s(-1)] but reacted less favorably with compound II [(9.8 ± 0.6) × 10(2) M(-1) s(-1)]. Oxidation of INH by MPO and hydrogen peroxide was unaffected by chloride, the physiological substrate for compound I, and the enzyme was partially converted to compound III. This indicates that INH is oxidized outside the classical peroxidation cycle. In combination with superoxide dismutase (SOD), MPO oxidized INH without exogenous hydrogen peroxide. SOD must favor reduction of oxygen by the INH radical to give superoxide and ultimately hydrogen peroxide. In both oxidation systems, an adduct with methionine was formed and it was a major product with MPO and SOD. We show that it is a conjugate of an acyldiimide with amines. INH substantially inhibited HOCl production by MPO and neutrophils below pharmacological concentrations. The reversible inhibition is explained by diversion of MPO to its ferrous and compound III forms during oxidation of INH. MPO, along with SOD released by Mtb, will oxidize INH at sites of infection and their interactions are likely to limit the efficacy of the drug, promote adverse drug reactions via formation of protein adducts, and impair a major bacterial killing mechanism of neutrophils.","pmid":"22846601","doi":"10.1016/j.bcp.2012.07.020","url":"https://pubmed.ncbi.nlm.nih.gov/22846601/"},{"id":1857,"title":"Myeloperoxidase: a leukocyte-derived protagonist of inflammation and cardiovascular disease.","authors":"Nussbaum, Claudia; Klinke, Anna; Adam, Matti; Baldus, Stephan; Sperandio, Markus","year":2013,"date":"2013 Feb 20","journal":"Antioxidants & redox signaling","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"SIGNIFICANCE: The heme-enzyme myeloperoxidase (MPO) is one of the major neutrophil bactericidal proteins and is stored in large amounts inside azurophilic granules of neutrophils. Upon cell activation, MPO is released and extracellular MPO has been detected in a wide range of acute and chronic inflammatory conditions. Recent ADVANCES AND CRITICAL ISSUES: Apart from its role during infection, MPO has emerged as a critical modulator of inflammation throughout the last decade and is currently discussed in the initiation and propagation of cardiovascular diseases. MPO-derived oxidants (e.g., hypochlorous acid) interfere with various cell functions and contribute to tissue injury. Recent data also suggest that MPO itself exerts proinflammatory properties independent of its catalytic activity. Despite advances in unraveling the complex action of MPO and MPO-derived oxidants, further research is warranted to determine the precise nature and biological role of MPO in inflammation. FUTURE DIRECTIONS: The identification of MPO as a central player in inflammation renders this enzyme an attractive prognostic biomarker and a potential target for therapeutic interventions. A better understanding of the (patho-) physiology of MPO is essential for the development of successful treatment strategies in acute and chronic inflammatory diseases.","pmid":"22823200","doi":"10.1089/ars.2012.4783","url":"https://pubmed.ncbi.nlm.nih.gov/22823200/"},{"id":1859,"title":"Effects of hypochlorous acid exposure on the rejection of salt, polyethylene glycols, boron and arsenic(V) by nanofiltration and reverse osmosis membranes.","authors":"Do, Van Thanh; Tang, Chuyang Y; Reinhard, Martin; Leckie, James O","year":2012,"date":"2012 Oct 15","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The separation layer of polyamide-based (PA) thin film composite (TFC) membranes can be modified by active chlorine species. The PA-TFC membranes, NF90, BW30 and NF270, were exposed to different concentrations of sodium hypochlorite (NaOCl) at pH 5 for 24 h. Elemental composition obtained from X-ray Photoelectron Spectroscopy (XPS) showed that the chlorine content in the PA layer increased with the chlorine concentrations. Treatment of membranes with 10 ppm Cl increased the membrane hydrophilicity. By contrast, when treated with 1000 ppm Cl or more, the membranes became less hydrophilic. Water permeability values for all 3 membrane types declined with increased chlorine concentrations. Filtration of polyethylene glycols (PEGs) with molecular weights of 200, 400 and 600 Daltons (Da) was performed to investigate the influence of chlorine treatment on membrane molecular weight cut off (MWCO) and rejection by size exclusion. Treatment with 10 and 100 ppm Cl lowered the MWCO while treatment with higher concentrations increased the MWCO. All chlorinated membranes experienced higher NaCl rejection compared to virgin ones. The performance of NF90 was tested with respect to the rejection of inorganic contaminants including boron (H(3)BO(3)) and arsenic (H(2)AsO(4)(-)). The boron rejection results paralleled PEG rejection whereas those for arsenic followed NaCl rejection patterns. The changes in membrane performance due to chlorine treatment were explained in terms of competing mechanisms: membrane tightening, bond cleavage by N-chlorination and chlorination promoted polyamide hydrolysis.","pmid":"22818949","doi":"10.1016/j.watres.2012.06.044","url":"https://pubmed.ncbi.nlm.nih.gov/22818949/"},{"id":1864,"title":"Enhanced inactivation of Salmonella and Pseudomonas biofilms on stainless steel by use of T-128, a fresh-produce washing aid, in chlorinated wash solutions.","authors":"Shen, Cangliang; Luo, Yaguang; Nou, Xiangwu; Bauchan, Gary; Zhou, Bin; Wang, Qin; Millner, Patricia","year":2012,"date":"2012 Oct","journal":"Applied and environmental microbiology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The effect of the washing aid T-128 (generally recognized as safe [GRAS] formulation, composed mainly of phosphoric acid and propylene glycol) on inactivation of Salmonella and Pseudomonas populations in biofilms on stainless steel was evaluated under conditions of increasing organic matter loads in chlorinated wash solutions dominated by hypochlorous acid. Biofilms were formed statically on stainless steel coupons suspended in 2% lettuce extract after inoculation with Salmonella enterica serovar Thompson or Newport or with Pseudomonas fluorescens. Coupons with biofilms were washed in chlorine solutions (0, 0.5, 1, 2, 5, 10, or 20 mg/liter at pH 6.5, 5.0 and 2.9), with or without T-128, and with increasing loads of organic matter (0, 0.25, 0.5, 0.75, or 1.0% lettuce extract). Cell populations on coupons were dispersed using intermittent, pulsed ultrasonication and vortexing and enumerated by colony counts on XLT-4 or Pseudomonas agars. Cell responses to fluorescent viability staining of biofilm treatment washing solutions were examined using confocal laser scanning microscopy. Results showed that 0.1% T-128 (without chlorine) reduced P. fluorescens biofilm populations by 2.5 log(10) units but did not reduce Salmonella populations. For both Salmonella and Pseudomonas, the sanitizing effect of free chlorine (1.0 to 5.0 mg/liter) was enhanced (P < 0.05) when it was combined with T-128. Application of T-128 decreased the free chlorine depletion rate caused by increasing organic matter in wash waters and significantly (P < 0.05) augmented inactivation of bacteria in biofilms compared to treatments without T-128. Image analysis of surfaces stained with SYTO and propidium iodide corroborate the cultural assay results showing that T-128 can aid in reducing pathogen viability in biofilms and thus can aid in sanitizing stainless steel contact surfaces during processing of fresh-cut produce.","pmid":"22752180","doi":"10.1128/AEM.01094-12","url":"https://pubmed.ncbi.nlm.nih.gov/22752180/"},{"id":1867,"title":"PEGylated D-amino acid oxidase restores bactericidal activity of neutrophils in chronic granulomatous disease via hypochlorite.","authors":"Nakamura, Hideaki; Fang, Jun; Mizukami, Tomoyuki; Nunoi, Hiroyuki; Maeda, Hiroshi","year":2012,"date":"2012 Jun","journal":"Experimental biology and medicine (Maywood, N.J.)","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Chronic granulomatous disease (CGD) causes impaired hydrogen peroxide (H(2)O(2)) generation. Consequently, neutrophils in patients with CGD fail to kill infecting pathogens. We expected that supplementation with H(2)O(2) would effectively restore the bactericidal function of neutrophils in CGD. Here, we used polyethylene glycol-conjugated D-amino acid oxidase (PEG-DAO) as an H(2)O(2) source. The enzyme DAO generates H(2)O(2) by using D-amino acid and oxygen as substrates. PEG-DAO plus D-amino acid indeed exerted bacteriostatic activity against Staphylococcus aureus via H(2)O(2) in vitro. Furthermore, use of PEG-DAO plus D-amino acids, which increased the amount of intracellular H(2)O(2), restored bactericidal activity of neutrophils treated with diphenylene iodonium, in which nicotinamide adenine dinucleotide phosphate (NADPH) oxidase was defective. This restoration of bactericidal activity was mediated by myeloperoxidase, with concomitant production of H(2)O(2) by PEG-DAO plus D-Ala. We also confirmed that PEG-DAO treatment restored bactericidal activity of congenitally defective neutrophils from patients with CGD. These results indicate that PEG-DAO can supply additional H(2)O(2) for defective NADPH oxidase of neutrophils from patients with CGD, and thus neutrophils regain bactericidal activity.","pmid":"22715431","doi":"10.1258/ebm.2012.011360","url":"https://pubmed.ncbi.nlm.nih.gov/22715431/"},{"id":1874,"title":"Colorimetric determination of hypochlorite with unmodified gold nanoparticles through the oxidation of a stabilizer thiol compound.","authors":"Zhang, Jia; Wang, Xiaolei; Yang, Xiurong","year":2012,"date":"2012 Jun 21","journal":"The Analyst","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"In this article, we report a colorimetric approach for the determination of hypochlorite (OCl(-)) with gold nanoparticles (Au NPs). The test proceeds as two individual steps and selectivity is developed based on the strong oxidizing ability of hypochlorite. In concentrated phosphate buffer (PB), the red solution of citrate-capped Au NPs could be stabilized by the chemisorption of 11-mercaptoundecanoic acid (MUA), without which the colloidal suspension turned blue because of salt-induced particles aggregation. However, by its oxidizing power, OCl(-) converted the alkanethiol to a sulfonate derivative, which could not protect Au NPs from aggregation, thereby a blue solution was observed after the subsequent addition of Au suspension. With this method and under the optimal conditions (28 nm Au NP, 50 mM PB, pH 7.0, and 10 min for the colorimetric response), 1.5 μM of OCl(-) can be easily visualized by the naked eye. This sensitive and selective colorimetric assay opens up a fresh insight of facile, rapid, and reliable detection of OCl(-), and may find its future application in the monitoring of OCl(-)/HOCl in waters sanitized by chlorine or hypochlorite compounds.","pmid":"22573188","doi":"10.1039/c2an35239g","url":"https://pubmed.ncbi.nlm.nih.gov/22573188/"},{"id":1877,"title":"Hypochlorous acid-induced heme damage of hemoglobin and its inhibition by flavonoids.","authors":"Gebicka, Lidia; Banasiak, Ewa","year":2012,"date":"2012 Sep","journal":"Toxicology in vitro : an international journal published in association with BIBRA","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Hypochlorous acid (HOCl), produced by activated neutrophils, is highly reactive oxidizing and chlorinating agent of biologically relevant molecules. Hemoglobin (Hb), present in large amounts inside red blood cells, is the main target for HOCl in these cells. In this work heme damage of hemoglobin induced by hypochlorous acid in the absence and presence of some popular dietary flavonoids, catechin, epigallocatechin gallate and quercetin has been studied by stopped-flow spectrophotometry. Hypochlorous acid, being in a large molar excess to hemoglobin, initiates modifications of the heme group of oxy- as well as of methemoglobin, which eventually leads to heme damage. Flavonoids present at concentrations comparable with that of hemoglobin inhibit these processes. The kinetics of the reactions of the investigated flavonoids with HOCl has been also studied and the rate constants of the order of 10(5)M(-1)s(-1) have been found. It is concluded that under conditions used in this study the inhibition of Hb heme damage by flavonoids results from the competition of these compounds with hemoglobin towards HOCl and/or from the formation of Hb-flavonoid complex in which heme group is more resistant against HOCl-induced damage.","pmid":"22542755","doi":"10.1016/j.tiv.2012.04.010","url":"https://pubmed.ncbi.nlm.nih.gov/22542755/"},{"id":1878,"title":"K⁺-Cl⁻ cotransport mediates the bactericidal activity of neutrophils by regulating NADPH oxidase activation.","authors":"Sun, Yuan-Ting; Shieh, Chi-Chang; Delpire, Eric; Shen, Meng-Ru","year":2012,"date":"2012 Jul 15","journal":"The Journal of physiology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Neutrophilic phagocytosis is an essential component of innate immunity. During phagocytosis, the generation of bactericidal hypochlorous acid(HOCl) requires the substrates, Cl− and superoxide produced by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase to kill the internalized pathogens. Here we show that the neutrophilic K+–Cl− cotransporter (KCC) constitutes aCl− permeation pathway and mediates the bactericidal activity by regulating NADPH oxidase activation. Dihydroindenyloxy alkanoic acid (DIOA), a KCC inhibitor, suppressed the toxin- or chemical-induced efflux of 36Cl− or 86Rb+, and diminished the production of superoxide in human and murine neutrophils. Inhibition of KCC activity or knockdown of KCC expression, in particular KCC3, reduced the phosphorylation as well as the membrane recruitment of oxidase components. Activated neutrophils displayed a significant colocalization of KCC3 and early endosomal marker, indicating that KCC3 could be localized on the phagosomes once neutrophils are activated. The NADPH oxidase activity and the phosphorylation level of oxidase component were 50% lower in the neutrophils isolated from KCC3−/− mice than in the neutrophils isolated from KCC3+/+ mice.Mortality rate after intraperitoneal challenge with Staphylococcus aureus was higher in KCC3−/− mice, and the bacterial clearance was impaired in the survivors.We conclude that, in activated neutrophil, NADPH oxidase complexes are associated with KCC3 at the plasma membrane and are internalized to form phagosomes, where KCC activity and expression level affect the production of oxidants.","pmid":"22526882","doi":"10.1113/jphysiol.2011.225300","url":"https://pubmed.ncbi.nlm.nih.gov/22526882/"},{"id":1879,"title":"Microbicidal activity of vascular peroxidase 1 in human plasma via generation of hypochlorous acid.","authors":"Li, Hong; Cao, Zehong; Moore, D Ray; Jackson, Patricia L; Barnes, Stephen; Lambeth, J David; Thannickal, Victor J; Cheng, Guangjie","year":2012,"date":"2012 Jul","journal":"Infection and immunity","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Members of the heme peroxidase family play an important role in host defense. Myeloperoxidase (MPO) is expressed in phagocytes and is the only animal heme peroxidase previously reported to be capable of using chloride ion as a substrate to form the highly microbicidal species hypochlorous acid (HOCl) at neutral pH. Despite the potent bacterial killing activity of HOCl, individuals who fail to express MPO typically show only a modest increase in some fungal infections. This may point to the existence of redundant host defense mechanisms. Vascular peroxidase 1 (VPO1) is newly discovered member of the heme peroxidase family. VPO1 is expressed in cells of the cardiovascular system and is secreted into the bloodstream. In the present study, we investigate whether VPO1 is capable of generating HOCl and its role in host defense. Like MPO, VPO1 in the presence of H₂O₂ and chloride generates HOCl. VPO1-dependent HOCl generation was demonstrated by chlorination of taurine and tyrosine using mass spectrometry. In addition, the VPO1/H₂O₂/Cl⁻ system can cause the chlorination of monochlorodimedone and the oxidation of 5-thio-2-nitrobenzoic acid. Purified VPO1 and VPO1 in plasma mediate bacterial killing that is dependent on chloride and H₂O₂; killing is inhibited by peroxidase inhibitors and by the H₂O₂ scavenger catalase. In the presence of erythrocytes, bacterial killing by VPO1 is slightly reduced. Thus, VPO1, in addition to MPO, is the second member of the heme peroxidase family capable of generating HOCl under physiological conditions. VPO1 is likely to participate in host defense, with bactericidal activity mediated through the generation of HOCl.","pmid":"22526679","doi":"10.1128/IAI.06337-11","url":"https://pubmed.ncbi.nlm.nih.gov/22526679/"},{"id":1880,"title":"Chemical fate and genotoxic risk associated with hypochlorite treatment of nicotine.","authors":"Zarrelli, Armando; DellaGreca, Marina; Parolisi, Alice; Iesce, Maria Rosaria; Cermola, Flavio; Temussi, Fabio; Isidori, Marina; Lavorgna, Margherita; Passananti, Monica; Previtera, Lucio","year":2012,"date":"2012 Jun 1","journal":"The Science of the total environment","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Nicotine, the main alkaloid of tobacco, is a non- prescription drug to which all members of a tobacco-smoking society are exposed either through direct smoke inhalation or through second-hand passive 'smoking'. Nicotine is also commercially available in some pharmaceutical products and is used worldwide as a botanical insecticide in agriculture. Nicotine dynamics in indoor and outdoor environments as well as the human excretions and the manufacturing process are responsible for its entry in the environment through municipal and industrial wastewater discharges. The presence of nicotine in surface and ground waters points out that it survives a conventional treatment process and persists in potable-water supplies. Complete removal of nicotine is instead reported when additional chlorination steps are used. In this paper a simulation of STP chlorination of nicotine and a genotoxic evaluation of its main degradation products are reported. Under laboratory conditions removal of nicotine seems not to be due to mineralization but to transformation in oxidized and chlorinated products. The by-products have been isolated after fractionation by diverse chromatographic procedures and their structures determined using mass spectrometry and (1)H and (13)C NMR spectroscopy. Preliminary genotoxic SOS Chromotests with Escherichia coli PQ37 evidence no toxicity of the products.","pmid":"22521104","doi":"10.1016/j.scitotenv.2012.03.047","url":"https://pubmed.ncbi.nlm.nih.gov/22521104/"},{"id":1881,"title":"Effect of thermal cycling and disinfection on colour stability of denture base acrylic resin.","authors":"Goiato, Marcelo C; Dos Santos, Daniela M; Baptista, Gabriella T; Moreno, Amália; Andreotti, Agda M; Bannwart, Lisiane C; Dekon, Stefan F C","year":2013,"date":"2013 Dec","journal":"Gerodontology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"OBJECTIVES: The purpose of this study was to investigate the effect of thermal cycling and disinfection on the colour change of denture base acrylic resin. MATERIALS AND METHODS: Four different brands of acrylic resins were evaluated (Onda Cryl, QC 20, Classico and Lucitone). All brands were divided into four groups (n = 7) determined according to the disinfection procedure (microwave, Efferdent, 4% chlorhexidine or 1% hypochlorite). The treatments were conducted three times a week for 60 days. All specimens were thermal cycled between 5 and 55°C with 30-s dwell times for 1000 cycles before and after disinfection. The specimens' colour was measured with a spectrophotometer using the CIE L*a*b* system. The evaluations were conducted at baseline (B), after first thermal cycling (T1 ), after disinfection (D) and after second thermal cycling (T2 ). Colour differences (ΔE) were calculated between T1 and B (T1 B), D and B (DB), and T2 and B (T2 B) time-points. RESULTS: The samples submitted to disinfection by microwave and Efferdent exhibited the highest values of colour change. There were significant differences on colour change between the time-points, except for the Lucitone acrylic resin. CONCLUSIONS: The thermal cycling and disinfection procedures significantly affected the colour stability of the samples. However, all values obtained for the acrylic resins are within acceptable clinical parameters.","pmid":"22519836","doi":"10.1111/j.1741-2358.2012.00676.x","url":"https://pubmed.ncbi.nlm.nih.gov/22519836/"},{"id":1882,"title":"Transmission electron microscopic analysis showing structural changes to bacterial cells treated with electrolyzed water and an acidic sanitizer.","authors":"Feliciano, Lizanel; Lee, Jaesung; Pascall, Melvin A","year":2012,"date":"2012 Apr","journal":"Journal of food science","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The effects of various sanitizers on the viability and cellular injury to structures of Escherichia coli and Listeria innocua were investigated. A food grade organic acidic formulation (pH 2.5) and acidic, neutral, and basic electrolyzed water [AEW (pH 2.7, oxidation reduction potential; ORP: 1100 mV, free available chlorine; FAC: 150 ppm), NEW (pH 6.9, ORP: 840 mV, FAC: 150 ppm), BEW (pH 11.6, ORP: -810 mV)] were used to treat E. coli and L. innocua cells. After 10 min of exposure to the sanitizers, changes to the bacterial numbers and cell structures were evaluated by plate counting and transmission electron microscopy (TEM), respectively. It was concluded from the results that the sanitizers reduced the E. coli cells between 2 and 3 log CFU/mL. Except for the BEW treatment, reductions in L. innocua population were greater (>1 log CFU/mL) than that of E. coli for all treatments. Data from the TEM showed that all sanitizers caused changes to the cell envelope and cytoplasm of both organisms. However, smaller changes were observed for L. innocua cells. Decrease in the integrity of the cell envelope and aggregation of the cytoplasmic components appeared to be mainly because of exposure to the sanitizers. The organic acid formulation and AEW were the most effective sanitizers against bacterial cells, indicating that penetration of acidic substances effectively caused the cell inactivation. PRACTICAL APPLICATION: An understanding of the method in which E-water and an acidic sanitizer cause injury to E. coli and L. innocua would be helpful in selecting an effective chemical agent as a food safety tool. This will allow a scientist to target similar microorganisms such as food borne bacteria with structures that are vulnerable to the sanitizer.","pmid":"22515246","doi":"10.1111/j.1750-3841.2012.02633.x","url":"https://pubmed.ncbi.nlm.nih.gov/22515246/"},{"id":1883,"title":"Laccase- and chloroperoxidase-nanotube paint composites with bactericidal and sporicidal activity.","authors":"Grover, Navdeep; Borkar, Indrakant V; Dinu, Cerasela Zoica; Kane, Ravi S; Dordick, Jonathan S","year":2012,"date":"2012 May 10","journal":"Enzyme and microbial technology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Laccase and chloroperoxidase (CPO) were separately immobilized onto multi-walled carbon nanotubes (MWNTs) and subsequently mixed with a commercial eco-friendly paint to generate biocatalytic coatings. The laccase-nanotube based paints showed >99% bactericidal activity against Escherichia coli and Staphylococcus aureus (both challenged with 10⁶ CFU/mL) within 30 min and >98% sporicidal activity against Bacillus cereus and Bacillus anthracis-ΔSterne (initially challenged with 10⁴ CFU/mL) within 120 min. The CPO-nanotube based paints also showed >99% antimicrobial activity within 30 min against E. coli and S. aureus (both challenged with 10⁶ CFU/mL). These enzyme-nanotube based formulations provide an eco-friendly route to generate biocidal compounds, which can prevent the growth of a broad spectrum of bacterial pathogens, including spores. These enzyme-containing paints may be envisioned to be applied as self-decontaminating coatings onto a wide range of surfaces, such as hospital infrastructure, medical devices and equipment, food processing and packaging, etc.; in all cases effective killing of a variety of infectious organisms is critical.","pmid":"22500892","doi":"10.1016/j.enzmictec.2012.01.006","url":"https://pubmed.ncbi.nlm.nih.gov/22500892/"},{"id":1885,"title":"Prevalence of dental erosion in adolescent competitive swimmers exposed to gas-chlorinated swimming pool water.","authors":"Buczkowska-Radlińska, J; Łagocka, R; Kaczmarek, W; Górski, M; Nowicka, A","year":2013,"date":"2013 Mar","journal":"Clinical oral investigations","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"OBJECTIVES: The purpose of this study was to analyze the prevalence of dental erosion among competitive swimmers of the local swimming club in Szczecin, Poland, who train in closely monitored gas-chlorinated swimming pool water. MATERIALS AND METHODS: The population for this survey consisted of a group of junior competitive swimmers who had been training for an average of 7 years, a group of senior competitive swimmers who had been training for an average of 10 years, and a group of recreational swimmers. All subjects underwent a clinical dental examination and responded to a questionnaire regarding aspects of dental erosion. In pool water samples, the concentration of calcium, magnesium, phosphate, sodium, and potassium ions and pH were determined. The degree of hydroxyapatite saturation was also calculated. RESULTS: Dental erosion was found in more than 26 % of the competitive swimmers and 10 % of the recreational swimmers. The lesions in competitive swimmers were on both the labial and palatal surfaces of the anterior teeth, whereas erosions in recreational swimmers developed exclusively on the palatal surfaces. Although the pH of the pool water was neutral, it was undersaturated with respect to hydroxyapatite. CONCLUSION: The factors that increase the risk of dental erosion include the duration of swimming and the amount of training. An increased risk of erosion may be related to undersaturation of pool water with hydroxyapatite components. CLINICAL RELEVANCE: To decrease the risk of erosion in competitive swimmers, the degree of dental hydroxyapatite saturation should be a controlled parameter in pool water.","pmid":"22476450","doi":"10.1007/s00784-012-0720-6","url":"https://pubmed.ncbi.nlm.nih.gov/22476450/"},{"id":1887,"title":"Effect of different disinfectants on the microhardness and roughness of acrylic resins for ocular prosthesis.","authors":"Moreno, Amália; Goiato, Marcelo C; dos Santos, Daniela M; Haddad, Marcela F; Pesqueira, Aldiéris A; Bannwart, Lisiane C","year":2013,"date":"2013 Mar","journal":"Gerodontology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Ocular prosthesis materials should have specific properties for their indication and durability; therefore, it is important to investigate their physical behaviour when affected by several disinfectants. OBJECTIVES: This study evaluated the influence of different disinfecting solutions on the microhardness and surface roughness of acrylic resins for ocular prosthesis. MATERIALS AND METHODS: Fifty samples simulating ocular prostheses were fabricated with N1 resin and colourless resin and divided (n = 10) according to the disinfectant used: neutral soap, Opti-free, Efferdent, 1% hypochlorite (HYC) and 4% chlorhexidine (CHX). Samples were stored in saline solution at 37°C and disinfected during 120 days. Both microhardness and roughness were investigated before, after 60 days and 120 days of disinfection and storage. Microhardness was measured using a microhardner and the roughness with a roughness device. RESULTS: N1 resin showed lower microhardness when compared with colourless resin (p < 0.05). HYC and CHX groups exhibited the highest change of microhardness and roughness values (p < 0.05). An increase in roughness and reduction in microhardness of ocular acrylic resins were observed after both periods of disinfection and storage (p < 0.05). CONCLUSION: Both disinfection/storage periods affected the microhardness and roughness values of the samples.","pmid":"22471379","doi":"10.1111/j.1741-2358.2012.00642.x","url":"https://pubmed.ncbi.nlm.nih.gov/22471379/"},{"id":1888,"title":"Enhancement of anti-cholinesterase activity of aqueous samples by hypochlorite oxidation for monitoring traces of organophosphorus pesticides in water.","authors":"Kanno, Ayako; Kawakami, Tsuyoshi; Takahashi, Yasuo; Onodera, Sukeo","year":2012,"date":"2012","journal":"The Journal of toxicological sciences","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"A reproducible method for monitoring traces of cholinesterase (ChE) inhibitors in aqueous samples is described: the method is based on chemical oxidation and a ChE inhibition assay. Chlorine was tested as an oxidizing reagent for conversion of various thiophosphorus pesticides (P=S compounds) into their P=O analogs, which have higher ChE-inhibiting activity. After treating buffered pesticide solutions (pH 6.0) with chlorine (final concentration less than 10 mg/l) of at 25°C for 15 min, the ChE-inhibiting activities and detection limits for each pesticide were determined. Greater ChE-inhibiting activities, leading to lower detection limits (ppb levels), were observed for the chlorine-treated solutions fortified azinphos methyl, diazinon, isoxathion and ronnel etc. No changes in the ChE-inhibiting activities were observed for carbamate pesticide solutions tested before and after chlorination, but an additive effect showed against ChE when these compounds were mixed with paraoxon in water. This combination of oxidative derivatization and ChE inhibition assay was applied successfully to the detection and determination of ChE inhibitors in natural and drinking water samples.","pmid":"22467030","doi":"10.2131/jts.37.389","url":"https://pubmed.ncbi.nlm.nih.gov/22467030/"},{"id":1889,"title":"Myeloperoxidase-derived chlorinating species induce protein carbamylation through decomposition of thiocyanate and urea: novel pathways generating dysfunctional high-density lipoprotein.","authors":"Holzer, Michael; Zangger, Klaus; El-Gamal, Dalia; Binder, Veronika; Curcic, Sanja; Konya, Viktoria; Schuligoi, Rufina; Heinemann, Akos; Marsche, Gunther","year":2012,"date":"2012 Oct 15","journal":"Antioxidants & redox signaling","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"AIMS: Protein carbamylation through cyanate is considered as playing a causal role in promoting cardiovascular disease. We recently observed that the phagocyte protein myeloperoxidase (MPO) specifically induces high-density lipoprotein (HDL) carbamylation, rather than chlorination, in human atherosclerotic lesions, raising the possibility that MPO-derived chlorinating species are involved in cyanate formation. RESULTS: Here, we show that MPO-derived chlorinating species rapidly decompose the plasma components thiocyanate (SCN) and urea, thereby promoting (lipo)protein carbamylation. Strikingly, the presence of physiologic concentrations of SCN completely prevented MPO-induced 3-chlorotyrosine formation in HDL. SCN scavenged a 2.5-fold molar excess of hypochlorous acid, promoting HDL carbamylation, but not chlorination. Cyanate significantly impaired (i) HDL's ability to activate lecithin-cholesterol acyltransferase; (ii) the activity of paraoxonase, a major HDL-associated anti-inflammatory enzyme; and (iii) the antioxidative activity of HDL. INNOVATION: Here, we report that MPO-derived chlorinating species preferentially induce protein carbamylation-rather than chlorination-in the presence of physiologically relevant SCN concentrations. The carbamylation of HDL results in the loss of its anti-inflammatory and antioxidative activities. CONCLUSION: MPO-mediated decomposition of SCN and/or urea might be a relevant mechanism for generating dysfunctional HDL in human disease.","pmid":"22462773","doi":"10.1089/ars.2011.4403","url":"https://pubmed.ncbi.nlm.nih.gov/22462773/"},{"id":1894,"title":"Evaluation of an automated dental unit water system's contamination control protocol.","authors":"Puttaiah, Raghunath; Svoboda, Kathy K H; Lin, Shih Ming; Montebugnoli, Lucio; Dolci, Giovanni; Spratt, David; Siebert, Jeff","year":2012,"date":"2012 Jan 1","journal":"The journal of contemporary dental practice","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: This study addresses the efficacy of an automated decontamination protocol using the germicide 'tetra acetyl ethylene diamine (TAED) perborate' (Farmec SpA, Italy). The germicide TAED perborate protocol is used in the Castellini Dental Units fitted with an Autosteril unit (an automated device that can cycle 0.26% TAED perborate solution and sterile water for cleaning the water system between patients and overnight). Prior to testing the Autosteril and the 0.26% TAED perborate protocol on the Logos Jr Dental Unit (Castellini SpA, Italy), TAED perborate was used on a dental unit water system simulation device. METHODS: A dental unit water system simulation device equipped with four dental unit water systems and with naturally grown and mature biofilm contamination was used in this study (three treatment units and one control). One treatment group used a simulated 5 minutes contact with TAED perborate and sterile water for irrigation; the second used a simulated 5 minutes contact with TAED perborate and 2 ppm ClO2 for irrigation; the third used a simulated 5 minutes contact with TAED perborate and municipal water for irrigation. The control group used municipal water for irrigation with no cleaning/disinfection protocols. This protocol was repeated for 30 cycles. Laser scanning confocal microscopy (LSCM) was used to study the effects on natural and mature biofilms, and R2A agar used to quantify heterotrophic plate counts in the effluent irrigant. Antimicrobial efficacy was evaluated by challenging TAED perborate with microbes and spores (M. smegmatis and B. subtilis). Deleterious effects of the germicide were evaluated on metal and nonmetal parts of dental unit water systems. Heterotrophic plate counts using R2A agar and LSCM of the lines were conducted to assess biofilm and microbial control. RESULTS: Baseline water samples showed mean contamination >5.6 log10 cfu/ml. After initial cleaning, all three groups maintained mean contamination levels of less than 1.1 (SD <0.3) log10 cfu/ml. LSCM of baseline samples was positive for live biofilm in all groups. At the end of the study, viable biofilm was only present in the control. In the microbial challenge test, all vegetative organisms were killed within 30 seconds of contact, while spores were killed within 5 minutes. Corrosion was seen in metals used in US-manufactured dental unit materials, while not observed in those used in the Castellini Logos Jr dental unit. CONCLUSION: In this study, the TAED perborate protocol was effective in biofilm control and control of dental treatment water contamination. Use of sterile water or 2 ppm ClO2 along with TAED treatment also controlled planktonic contamination effectively. CLINICAL SIGNIFICANCE: Environmental biofilms contaminate dental unit water systems over time and affect the quality of dental treatment water. Contaminants include environmental biofilms, microbes, including gram-negative rods and endotoxins in high doses that are not of acceptable quality for treating patients. There are many germicidal protocols for treating this contamination and one such is the prescribed use of TAED perborate used in conjunction with sterile water for irrigation in the autosteril device, an integral component of the Castellini dental units for between patient decontamination of dental unit water systems. This study was conducted on an automated simulation dental unit water system to test the TAED perborate protocol's efficacy on naturally grown, mature environmental biofilms, it's efficacy on microbes and spores and it's effects on materials used in dental unit water systems. This translational research addresses both microbial control and material effects of TAED perborate in studying efficacy and possible deleterious effects and simulated use in dentistry. Currently, this antimicrobial use protocol is followed worldwide in the Castellini dental units that are used in day-to-day dental patient care.","pmid":"22430686","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/22430686/"},{"id":1895,"title":"The effects of environmental conditions on persistence and inactivation of Brucella suis on building material surfaces.","authors":"Calfee, M Worth; Wendling, M","year":2012,"date":"2012 Jun","journal":"Letters in applied microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"AIMS: The purpose of this study was to evaluate the effects of environmental conditions and material type on persistence and inactivation of Brucella suis. METHODS AND RESULTS: Brucella suis (approx. 1 × 10(8) CFU) was spiked onto surfaces (glass, aluminium and wood) by liquid inoculation. Persistence was evaluated over 56 days at 22 ± 2°C, 40 ± 15% r.h. and 5 ± 3°C, 30 ± 15% r.h. In addition, three readily available decontaminants (pH-adjusted bleach, 70% ethanol and 1% citric acid) were evaluated for their effectiveness at inactivating Br. suis on these materials. Decontaminations were conducted following 0 and 28 days exposure to the two conditions. Results indicated that Br. suis can persist on environmental surfaces for at least 56 days. Persistence was highest at low temperature. Decontamination was most challenging on wood with all three decontaminants. CONCLUSIONS: Following a Br. suis contamination incident, passive decontamination (through attenuation) may not be feasible, as this organism can persist for months. In addition, the results suggest that some sporicidal decontaminants may be ineffective on materials such as wood, even for vegetative biological agents such as Br. suis. SIGNIFICANCE AND IMPACT OF STUDY: This study aids incident commanders and remediation experts to make informed decisions regarding decontamination after a biological contamination incident.","pmid":"22409312","doi":"10.1111/j.1472-765X.2012.03237.x","url":"https://pubmed.ncbi.nlm.nih.gov/22409312/"},{"id":1897,"title":"Control of bacterial contamination of washbasin taps and output water using Ecasol: a one-year study.","authors":"Boyle, M A; O'Donnell, M J; Miller, A; Russell, R J; Coleman, D C","year":2012,"date":"2012 Apr","journal":"The Journal of hospital infection","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: Contaminated washbasin taps and output water are an important source of bacteria that may cause nosocomial infection. A five-week pretreatment study of hot and cold water from 15 washbasin taps at Dublin Dental Hospital showed consistently heavy contamination by aerobic heterotrophic bacteria: mean bacterial counts of 482.5 [standard deviation (SD) 293] colony-forming units (cfu)/mL and 5022 (SD 4322) cfu/mL, respectively. AIM: To minimize microbial contamination of washbasin taps and output water in the long term using the electrochemically generated, pH-neutral disinfectant, Ecasol. METHODS: Initially, the 15,000-L water tank providing cold and hot water to washbasins, calorifiers and the distribution network were drained and sediment was removed. The system was shock-dosed with Ecasol 100 ppm to eradicate gross contamination and biofilms. Thereafter, tank water was automatically maintained at Ecasol 2.5 ppm prior to distribution. The microbiological quality of water from five sentinel washbasin taps was monitored weekly for 54 weeks using R2A agar. FINDINGS: The mean counts for hot, cold, mains and tank water during the 54-week study period were 1 (SD 4) cfu/mL, 2 (SD 4) cfu/mL, 205 (SD 160) cfu/mL and 0 cfu/mL, respectively. Swab samples of 33/40 taps, each tested on three separate occasions, yielded no growth on R2A agar, while five samples yielded <20 cfu/swab and two samples yielded >200 cfu/swab. No detrimental effects due to Ecasol were observed in the water network. CONCLUSION: Ecasol consistently minimized bacterial contamination of washbasin taps and output water in a dental hospital setting.","pmid":"22382277","doi":"10.1016/j.jhin.2012.01.011","url":"https://pubmed.ncbi.nlm.nih.gov/22382277/"},{"id":1901,"title":"Laboratory evaluation of large-scale decontamination approaches.","authors":"Calfee, M W; Ryan, S P; Wood, J P; Mickelsen, L; Kempter, C; Miller, L; Colby, M; Touati, A; Clayton, M; Griffin-Gatchalian, N; McDonald, S; Delafield, R","year":2012,"date":"2012 May","journal":"Journal of applied microbiology","category":"Materials & industrial applications","evidence":"Journal article / other","relevance":"Medium","abstract":"AIMS: To evaluate the effectiveness of two spray-based decontamination methods for surface contamination reduction and to determine the potential for contamination spread by these methods. METHODS AND RESULTS: Material coupons (treated plywood and concrete) were contaminated with c. 1 × 10(7) spores of Bacillus atrophaeus by aerosol deposition. Decontaminants (pH-adjusted bleach or Spor-Klenz(®) RTU) were applied to coupons by either backpack sprayer or gas-powered sprayer. Contact time, reapplication frequency and rinse method were also varied. In addition to surface removal efficacy, partitioning of contamination between the rinsate and aerosol fractions was determined. Results indicated that pH-adjusted bleach was effective (≥6 logs reduction) when two applications and a 30 min contact time were administered, regardless of the decontaminant application method or material. Spor-Klenz(®) RTU was effective on wood, but achieved ≤3 logs reduction on concrete. A shortened application procedure with pH-adjusted bleach resulted in lower efficacy on wood, and a greater apparent potential for contamination spread. CONCLUSIONS: Consideration of material surface type is important when selecting a decontaminant. Also, achieving conditions that effectively inactivate surface biological contamination are critical to preventing the spread of contamination. SIGNIFICANCE AND IMPACT OF THE STUDY: Results presented here are intended to help development of remediation plans following a biological contamination incident.","pmid":"22332972","doi":"10.1111/j.1365-2672.2012.05259.x","url":"https://pubmed.ncbi.nlm.nih.gov/22332972/"},{"id":1906,"title":"Protective role of D-amino acid oxidase against Staphylococcus aureus infection.","authors":"Nakamura, Hideaki; Fang, Jun; Maeda, Hiroshi","year":2012,"date":"2012 Apr","journal":"Infection and immunity","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"D-Amino acid oxidase (DAO) is a hydrogen peroxide-generating enzyme that uses a D-amino acid as a substrate. We hypothesized that DAO may protect against bacterial infection, because hydrogen peroxide is one of the most important molecules in the antibacterial defense systems in mammals. We show here that DAO suppressed the growth of Staphylococcus aureus in a manner that depended on the concentration of DAO and D-amino acid in vitro. Addition of catalase abolished the bacteriostatic activity of DAO. Although DAO plus D-Ala showed less bactericidal activity, addition of myeloperoxidase (MPO) greatly enhanced the bactericidal activity of DAO. Furthermore, DAO was able to utilize bacterial lysate, which contains D-Ala derived from peptidoglycan; this could produce hydrogen peroxide with, in the presence of myeloperoxidase, formation of hypochlorous acid. This concerted reaction of DAO and MPO led to the bactericidal action. In vivo experiments showed that DAO(-/-) (mutant) mice were more susceptible to S. aureus infection than were DAO(+/+) (wild-type) mice. These results suggest that DAO, together with myeloperoxidase, may play an important role in antibacterial systems in mammals.","pmid":"22271930","doi":"10.1128/IAI.06214-11","url":"https://pubmed.ncbi.nlm.nih.gov/22271930/"},{"id":1910,"title":"Hypochlorous acid regulates neutrophil extracellular trap release in humans.","authors":"Palmer, L J; Cooper, P R; Ling, M R; Wright, H J; Huissoon, A; Chapple, I L C","year":2012,"date":"2012 Feb","journal":"Clinical and experimental immunology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Neutrophil extracellular traps (NETs) comprise extracellular chromatin and granule protein complexes that immobilize and kill bacteria. NET release represents a recently discovered, novel anti-microbial strategy regulated non-exclusively by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase generation of reactive oxygen intermediates (ROIs), particularly hydrogen peroxide. This study aimed to characterize the role of ROIs in the process of NET release and to identify the dominant ROI trigger. We employed various enzymes, inhibitors and ROIs to record their effect fluorometrically on in vitro NET release by human peripheral blood neutrophils. Treatment with exogenous superoxide dismutase (SOD) supported the established link between hydrogen peroxide and NET production. However, treatment with myeloperoxidase inhibitors and direct addition of hypochlorous acid (HOCl; generated in situ from sodium hypochlorite) established that HOCl was a necessary and sufficient ROI for NET release. This was confirmed by the ability of HOCl to stimulate NET release in chronic granulomatous disease (CGD) patient neutrophils which, due to the lack of a functional NADPH oxidase, also lack the capacity for NET release in response to classical stimuli. Moreover, the exogenous addition of taurine, abundantly present within the neutrophil cytosol, abrogated NET production stimulated by phorbol myristate acetate (PMA) and HOCl, providing a novel mode of cytoprotection by taurine against oxidative stress by taurine.","pmid":"22236002","doi":"10.1111/j.1365-2249.2011.04518.x","url":"https://pubmed.ncbi.nlm.nih.gov/22236002/"},{"id":1913,"title":"Degradation of polyamide nanofiltration and reverse osmosis membranes by hypochlorite.","authors":"Do, Van Thanh; Tang, Chuyang Y; Reinhard, Martin; Leckie, James O","year":2012,"date":"2012 Jan 17","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The degradation of polyamide (PA) nanofiltration and reverse osmosis membranes by chlorine needs to be understood in order to develop chlorine-resistant membranes. Coated and uncoated fully aromatic (FA) and piperazine (PIP) semi-aromatic PA membranes were treated with hypochlorite solution and analyzed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR). XPS results showed that in chlorine treated FA PA membranes the ratio of bound chlorine to surface nitrogen was 1:1 whereas it was only 1:6 in the case of PIP PA membranes. Surface oxygen of uncoated FA and PIP membranes increased with increasing hypochlorite concentration whereas it decreased for coated FA membranes. High resolution XPS data support that chlorination increased the number of carboxylic groups on the PA surface, which appear to form by hydrolysis of the amide bonds (C(O)-N). FTIR data indicated the disappearance of the amide II band (1541 cm(-1)) and aromatic amide peak (1609 cm(-1)) in both coated and uncoated chlorinated FA membranes, consistent with the N-chlorination suggested by the XPS results. Furthermore, the surface charge of chlorinated membranes at low pH (<6) became negative, consistent with amide-nitrogen chlorination. Chlorination appeared to both increase and decrease membrane hydrophobicity depending on chlorination exposure conditions, which implied that N-chlorination and hydrolysis may be competing processes. The effects of property changes on the membrane performance were also observed for NF90, BW30, and NF270 membranes.","pmid":"22221176","doi":"10.1021/es203090y","url":"https://pubmed.ncbi.nlm.nih.gov/22221176/"},{"id":1914,"title":"Myeloperoxidase targets apolipoprotein A-I, the major high density lipoprotein protein, for site-specific oxidation in human atherosclerotic lesions.","authors":"Shao, Baohai; Pennathur, Subramaniam; Heinecke, Jay W","year":2012,"date":"2012 Feb 24","journal":"The Journal of biological chemistry","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Oxidative damage by myeloperoxidase (MPO) has been proposed to deprive HDL of its cardioprotective effects. In vitro studies reveal that MPO chlorinates and nitrates specific tyrosine residues of apoA-I, the major HDL protein. After Tyr-192 is chlorinated, apoA-I is less able to promote cholesterol efflux by the ABCA1 pathway. To investigate the potential role of this pathway in vivo, we used tandem mass spectrometry with selected reaction monitoring to quantify the regiospecific oxidation of apoA-I. This approach demonstrated that Tyr-192 is the major chlorination site in apoA-I in both plasma and lesion HDL of humans. We also found that Tyr-192 is the major nitration site in apoA-I of circulating HDL but that Tyr-18 is the major site in lesion HDL. Levels of 3-nitrotyrosine strongly correlated with levels of 3-chlorotyrosine in lesion HDL, and Tyr-18 of apoA-I was the major nitration site in HDL exposed to MPO in vitro, suggesting that MPO is the major pathway for chlorination and nitration of HDL in human atherosclerotic tissue. These observations may have implications for treating cardiovascular disease, because recombinant apoA-I is under investigation as a therapeutic agent and mutant forms of apoA-I that resist oxidation might be more cardioprotective than the native form.","pmid":"22219194","doi":"10.1074/jbc.M111.337345","url":"https://pubmed.ncbi.nlm.nih.gov/22219194/"},{"id":1916,"title":"Assessing the reactivity of free chlorine constituents Cl₂, Cl₂O, and HOCl toward aromatic ethers.","authors":"Sivey, John D; Roberts, A Lynn","year":2012,"date":"2012 Feb 21","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Cl(2) and Cl(2)O are highly reactive electrophiles capable of influencing rates of disinfection byproduct (DBP) precursor chlorination in solutions of free available chlorine (FAC). The current work examines how organic compound structure influences susceptibility toward chlorination by Cl(2) and Cl(2)O relative to the more abundant (but less reactive) electrophile HOCl. Chlorination rates and products were determined for three aromatic ethers, whose reactivities with FAC increased in the order: 3-methylanisole <1,3-dimethoxybenzene <1,3,5-trimethoxybenzene. Varying solution conditions (pH, [FAC], [Cl(-)]) permitted quantification of regiospecific second-order rate constants for formation of each product by Cl(2), Cl(2)O, and HOCl. Our results indicate that as the reactivity of methoxybenzenes decreases, the importance of Cl(2) and Cl(2)O (relative to HOCl) increases. Accordingly, Cl(2) and Cl(2)O are likely to play important roles in generating DBPs that originate from natural organic matter (NOM) constituents of somewhat moderate reactivity. As [Cl(2)] is proportional to [Cl(-)] and [Cl(2)O] is proportional to [HOCl](2), ramifications for DBP control measures may differ significantly for these precursors compared to more reactive NOM moieties likely to react predominantly with HOCl. In particular, the role of chloride as a chlorination catalyst challenges its traditional classification as an \"inert\" electrolyte in water treatment processes.","pmid":"22211432","doi":"10.1021/es203094z","url":"https://pubmed.ncbi.nlm.nih.gov/22211432/"},{"id":1920,"title":"Severe hypoxaemia due to methaemoglobinaemia and aspiration pneumonia.","authors":"Mizutani, Tomonori; Hojo, Masayuki","year":2012,"date":"2012 Jan","journal":"Emergency medicine journal : EMJ","category":"Food & agriculture","evidence":"Case report","relevance":"High","abstract":"The authors report a case of a previously healthy 40-year-old man who was admitted to the emergency department due to severe hypoxaemia after emesis. He vomited after a cup of coffee with the milk at his office. On admission, he showed cyanosis and oxygen saturation measured by pulse oximetry was extremely low (86%) in spite of the administration of 10 litres of oxygen. The authors suspected pneumonia, but oxygen saturation was disproportionately low to pneumonia severity. Oxygen saturation measured by pulse oximetry was significantly different from oxygen saturation calculated from arterial blood gas analysis, suggesting the existence of haemoglobin abnormality. The level of methaemoglobin was 9.3% (reference range, 1-2%). The patient was treated by antibiotics for pneumonia, and his methaemoglobinaemia was spontaneously ameliorated. The authors later found that the patient drank bleach containing hypochlorous acid instead of milk by mistake. To conclude, the patient's hypoxaemia was due to pneumonia and drug-induced acquired methaemoglobinaemia.","pmid":"22186266","doi":"10.1136/emj.03.2011.3937rep","url":"https://pubmed.ncbi.nlm.nih.gov/22186266/"},{"id":1924,"title":"Hypochlorous acid-induced heme degradation from lactoperoxidase as a novel mechanism of free iron release and tissue injury in inflammatory diseases.","authors":"Souza, Carlos Eduardo A; Maitra, Dhiman; Saed, Ghassan M; Diamond, Michael P; Moura, Arlindo A; Pennathur, Subramaniam; Abu-Soud, Husam M","year":2011,"date":"2011","journal":"PloS one","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Lactoperoxidase (LPO) is the major consumer of hydrogen peroxide (H(2)O(2)) in the airways through its ability to oxidize thiocyanate (SCN(-)) to produce hypothiocyanous acid, an antimicrobial agent. In nasal inflammatory diseases, such as cystic fibrosis, both LPO and myeloperoxidase (MPO), another mammalian peroxidase secreted by neutrophils, are known to co-localize. The aim of this study was to assess the interaction of LPO and hypochlorous acid (HOCl), the final product of MPO. Our rapid kinetic measurements revealed that HOCl binds rapidly and reversibly to LPO-Fe(III) to form the LPO-Fe(III)-OCl complex, which in turn decayed irreversibly to LPO Compound II through the formation of Compound I. The decay rate constant of Compound II decreased with increasing HOCl concentration with an inflection point at 100 µM HOCl, after which the decay rate increased. This point of inflection is the critical concentration of HOCl beyond which HOCl switches its role, from mediating destabilization of LPO Compound II to LPO heme destruction. Lactoperoxidase heme destruction was associated with protein aggregation, free iron release, and formation of a number of fluorescent heme degradation products. Similar results were obtained when LPO-Fe(II)-O(2), Compound III, was exposed to HOCl. Heme destruction can be partially or completely prevented in the presence of SCN(-). On the basis of the present results we concluded that a complex bi-directional relationship exists between LPO activity and HOCl levels at sites of inflammation; LPO serve as a catalytic sink for HOCl, while HOCl serves to modulate LPO catalytic activity, bioavailability, and function.","pmid":"22132121","doi":"10.1371/journal.pone.0027641","url":"https://pubmed.ncbi.nlm.nih.gov/22132121/"},{"id":1927,"title":"[Myeloperoxidase-induced biodegradation of single-walled carbon nanotubes is mediated by hypochlorite].","authors":"Vlasova, I I; Sokolov, A V; Chekanov, A V; Kostevich, V A; Vasil'ev, V B","year":2011,"date":"2011 Jul-Aug","journal":"Bioorganicheskaia khimiia","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Broad prospects for the use of single-walled carbon nanotubes (SWNTs) in medicine and biotechnology raise the concerns about both their toxicity, and the mechanisms of biodegradation and excretion from the body. SWNTs biodegradation as a result of catalytic activity of myeloperoxidase (MPO) was shown in the isolated MPO system as well as in the suspension of neutrophils [Kagan V.E., et al., 2010]. In the present study we analyzed the ability of different MPO-produced oxidants to participate in the modification and degradation of SWNTs. The comparison of the ability of various peroxidases to degrade SWNTs in vitro revealed that myeloperoxidase, due to its ability to produce hypochlorite, and lactoperoxidase, due to its ability to produce hypobromite, are extremely efficient in the degradation of carbon nanotubes. The biodegradation of SWNTs in the model system can also be caused by free radicals generated as a result of heme degradation and, to a lesser extent, by active oxoferryl intermediates of peroxidases. Our experiments showed that in the presence of blood plasma, peroxidase intermediates or free radical products of heme degradation were unable to initiate biodegradation of carbon nanotubes, only the generation of hypochlorite by MPO can cause the biodegradation of carbon nanotubes in vivo. Titration of SWNTs suspension containing plasma with hypochlorite at high concentrations resulted in the decrease in the optical absorbance of the suspension indicating the degradation of nanotubes. Our results clearly indicate that hypochlorite can serve as a main oxidizing agent which is able to modify and degrade nanotubes in the sites of inflammation and in the phagosomes.","pmid":"22096994","doi":"10.1134/s1068162011040157","url":"https://pubmed.ncbi.nlm.nih.gov/22096994/"},{"id":1932,"title":"Comparison of different washing treatments for reducing pathogens on orange surfaces and for preventing the transfer of bacterial pathogens to fresh-squeezed orange juice.","authors":"Martínez-Gonzáles, N E; Martínez-Chávez, L; Martínez-Cárdenas, C; Castillo, A","year":2011,"date":"2011 Oct","journal":"Journal of food protection","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The objectives of this study were to compare the effectiveness of various washing treatments for reducing Escherichia coli O157:H7, Salmonella sp., and Listeria monocytogenes populations on orange surfaces and to measure the effect of some of these treatments in preventing the transfer of pathogens during juice extraction. Orange surfaces inoculated with L. monocytogenes or a mixture of E. coli O157:H7 and Salmonella Typhimurium were washed by water spray and then sprayed with or dipped in water at 80°C for 1 min, 70% ethanol for 15, 30, or 45 s or 1, 2, or 4 min, 2 or 4% lactic acid solution at 55°C for 15, 30, or 45 s or 1, 2, or 4 min, or 200 mg/liter hypochlorite at pH 6.5 or 10 for 15 s. The surviving populations of these pathogens on the oranges were enumerated after each treatment. In a further stage, the ability of these pathogens to be transferred to the juice during extraction was tested. Juice was obtained from inoculated oranges that were subjected to selected treatments using chlorine, lactic acid, ethanol, and hot water as described above, and then bacterial counts in orange juice were determined. The application of these treatments reduced the populations of pathogens on orange surfaces by 1.9 to >4.9 log, 1.9 to >4.6 log, and 1.4 to 3.1 log cycles for E. coli O157:H7, Salmonella Typhimurium, and L. monocytogenes, respectively. The treatments using hot water or lactic acid showed greater reductions than other treatments. The time, antimicrobial concentration, and form of application affected the bacterial reduction. All treatments resulted in undetectable counts in the juice. Nevertheless, pathogens were recovered by the enrichment-plating method. Treatment of oranges before juice extraction may reduce the risk associated with consuming orange juice.","pmid":"22004816","doi":"10.4315/0362-028X.JFP-10-357","url":"https://pubmed.ncbi.nlm.nih.gov/22004816/"},{"id":1933,"title":"Effect of disinfection and storage on the flexural strength of ocular prosthetic acrylic resins.","authors":"Goiato, Marcelo C; dos Santos, Daniela M; Moreno, Amália; Iyda, Mariana G; Rezende, Maria C R A; Haddad, Marcela F","year":2012,"date":"2012 Jun","journal":"Gerodontology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"OBJECTIVE: To evaluate the influence of chemical disinfection and storage duration on the flexural strength of acrylic resins commonly used to make ocular prostheses. METHODS: A total of 260 samples were manufactured with N1 resin and colourless resin. Both resins were thermopolymerised using a microwave oven. Samples were stored and periodically disinfected and were divided into groups: control (no disinfection) (I), neutral soap (II), Opti-free (III), Efferdent (IV), 1% hypochlorite (V) or 4% chlorhexidine (VI). The flexural strength was measured before and after 60 and 120 days of storage. Data were analysed by anova and Tukey test (0.05). RESULTS: The flexural strength of the N1 resin was higher than that for the colourless resin. There was a significant difference in the flexural strength before and after 60 and 120 days of storage with disinfection, regardless of the resin and disinfectant. Group I in the initial period exhibited greater flexural strength, with significant difference only in group VI after 120 days. CONCLUSION: It can be concluded that the flexural strength only changed after 120 days of storage for samples disinfected with chlorhexidine. However, all flexural strength values obtained herein were acceptable clinical limits for the acrylic resins.","pmid":"22004090","doi":"10.1111/j.1741-2358.2011.00570.x","url":"https://pubmed.ncbi.nlm.nih.gov/22004090/"},{"id":1934,"title":"Preparation and X-ray crystal study of benziodoxaborole derivatives: new hypervalent iodine heterocycles.","authors":"Nemykin, Victor N; Maskaev, Andrey V; Geraskina, Margarita R; Yusubov, Mekhman S; Zhdankin, Viktor V","year":2011,"date":"2011 Nov 7","journal":"Inorganic chemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"A series of heterocyclic compounds containing trivalent iodine, oxygen, and boron in a five-membered ring were prepared and structurally investigated by X-ray crystallography. 1-Chloro-4-fluoro-1H-1λ(3)-benzo[d][1,2,3]iodoxoborol-3-ol was synthesized by chlorination of 2-fluoro-6-iodophenylboronic acid followed by treatment of the intermediate iododichloride with water. 1-Acetoxy-4-fluoro-1H-1λ(3)-benzo[d][1,2,3]iodoxoborol-3-ol, 1-acetoxy-1H-1λ(3)-benzo[d][1,2,3]iodoxoborol-3-ol, and similar 1-substituted trifluoroacetate derivatives of benziodoxaborole were prepared the hypochlorite oxidation of 2-fluoro-6-iodophenylboronic acid or 2-iodophenylboronic acid in acetic or trifluoroacetic acid, respectively. 1-Acetoxy substituted benziodoxaborole can be further converted to the respective trifluoroacetate by treatment with trifluoroacetic acid or to the 1-hydroxy derivative by basic hydrolysis with aqueous NaHCO(3). X-ray structural studies of 1-chloro- and 1-trifluoroacetoxy substituted benziodoxaboroles 13, 17, and 18 have shown the presence of a planar five-membered heterocyclic ring with unusually short endocyclic I-O bond distance of 2.04-2.09 Å. Slow crystallization of 4-fluoro-1-trifluoroacetoxy-1H-1λ(3)-benzo[d][1,2,3]iodoxoborol-3-ol from methanol resulted in the formation of a tetrameric macrocyclic structure 21 resulting from self-assembly of the initially formed 4-fluoro-1,3-dimethoxy-1H-1λ(3)-benzo[d][1,2,3]iodoxoborol. Structural parameters of the five-membered iodoxoborol ring, such as the planar geometry and the short B-O and O-I bonds lengths in 13, 17, and 18 compared to those in 21 and known benziodoxoles are indicative of partially aromatic character of this ring. Density functional theory (DFT) predicted NIST (0) and NIST (1) indexes for 1-chloro- and 1-trifluoroacetoxy substituted benziodoxaboroles, however, are indicative of significantly lower aromaticity compared to the classic aromatic systems.","pmid":"21988373","doi":"10.1021/ic201922n","url":"https://pubmed.ncbi.nlm.nih.gov/21988373/"},{"id":1936,"title":"Optimizing acidified bleach solutions to improve sporicidal efficacy on building materials.","authors":"Wood, J P; Calfee, M W; Clayton, M; Griffin-Gatchalian, N; Touati, A","year":2011,"date":"2011 Dec","journal":"Letters in applied microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"AIMS: We evaluated whether lowering pH (with acetic acid) and raising free available chlorine (FAC) levels in bleach solutions would improve efficacy in inactivating Bacillus spores on different materials. We also determined how varying pH and FAC levels affected bleach stability. METHODS AND RESULTS: Acidified bleach solutions with pH levels of 4.5, 6 and 7.5 and FAC levels between 5000 and 10,000 ppm were evaluated for decontamination efficacy against Bacillus subtilis spores inoculated onto test coupons made from wood, ceramic and galvanized steel. Lowering the pH or increasing the FAC level improved efficacy in some of the tests, but depended on the material, which significantly affected decontamination efficacy. The acidified bleach at pH of 7.5 was significantly less effective than bleach at a pH of 4.5 or 6. The FAC levels in the bleach were the most stable at pH 4.5, and stability at pH 4.5 was not significantly affected by the initial FAC level. CONCLUSIONS: It may be advisable to use bleach solutions with lower pH (rather than high FAC levels) in light of both the decontamination efficacy and bleach stability results. For wood materials, use of sporicides other than acidified bleach may be warranted. SIGNIFICANCE AND IMPACT OF THE STUDY: These results may be useful in preparing acidified bleach solutions for decontamination of materials contaminated with spores such as Bacillus anthracis.","pmid":"21981715","doi":"10.1111/j.1472-765X.2011.03162.x","url":"https://pubmed.ncbi.nlm.nih.gov/21981715/"},{"id":1937,"title":"Antioxidant activity of flavonoids evaluated with myoglobin method.","authors":"Terashima, Masaaki; Kakuno, Yuri; Kitano, Naruho; Matsuoka, Chiharu; Murase, Mayumi; Togo, Naoko; Watanabe, Ryoko; Matsumura, Saki","year":2012,"date":"2012 Feb","journal":"Plant cell reports","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Antioxidant activities of four flavonoids (rutin, quercetin, luteolin, and kaempferol) and two non-flavonoids (chlorogenic acid and pyrocatechol) against four reactive oxygen species (ROS) have been measured with a myoglobin method developed by our group. The myoglobin method uses the absorbance changes of myoglobin (a probe molecule) due to the reaction with the ROS as an indicator for the antioxidant activity measurement. Myoglobin protective ratio (MPR) was defined to express the antioxidant activities of the specimens. Antioxidant activities against hypochlorite ion, hydroxyl radical, peroxyl radical, and peroxynitrite were measured with the myoglobin method. The antioxidant activities were comprehensively evaluated by plotting MPR against four ROS and vitamin C equivalent concentration evaluated by DPPH quenching method in 5-axe cobweb charts. The four flavonoids show a very similar pattern in the 5-axe cobweb charts, while the patterns of two non-flavonoids are quite different from that of the flavonoids. This procedure combining the myoglobin method with the cobweb charts is useful in the evaluation of antioxidant activities of plant-derived food, and also can be extended to monitor antioxidant condition of media for plant cell cultures.","pmid":"21971747","doi":"10.1007/s00299-011-1163-2","url":"https://pubmed.ncbi.nlm.nih.gov/21971747/"},{"id":1939,"title":"Selective and absolute quantification of endogenous hypochlorous acid with quantum-dot conjugated microbeads.","authors":"Yang, Yi-Cyun; Lu, Hsueh-Han; Wang, Wei-Ti; Liau, Ian","year":2011,"date":"2011 Nov 1","journal":"Analytical chemistry","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Endogenous hypochlorous acid (HOCl) secreted by leukocytes plays a critical role in both the immune defense of mammalians and the pathogenesis of various diseases intimately related to inflammation. We report the first selective and absolute quantification of endogenous HOCl produced by leukocytes in vitro and in vivo with a novel quantum dot-based sensor. An activated human neutrophil secreted 6.5 ± 0.9 × 10(8) HOCl molecules into its phagosome, and kinetic measurement for the secretions showed that the extracellular generation of HOCl was temporally retarded, but the quantity eventually attained a level comparable with its intraphagosomal counterpart with a delay of about 1.5 h. The quantity of HOCl secreted from the hepatic leukocytes of rats with or without stimulation of lipopolysaccharide was also determined. These results indicate a possibility to extend our approach to not only clinical settings for quantitative assessment of the bactericidal capability of isolated leukocytes of patients but also fundamental biomedical research that requires critical evaluation of the inflammatory response of animals.","pmid":"21950322","doi":"10.1021/ac202077x","url":"https://pubmed.ncbi.nlm.nih.gov/21950322/"},{"id":1946,"title":"Human apolipoprotein A-I-derived amyloid: its association with atherosclerosis.","authors":"Ramella, Nahuel A; Rimoldi, Omar J; Prieto, Eduardo D; Schinella, Guillermo R; Sanchez, Susana A; Jaureguiberry, María S; Vela, María E; Ferreira, Sergio T; Tricerri, M Alejandra","year":2011,"date":"2011","journal":"PloS one","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Amyloidoses constitute a group of diseases in which soluble proteins aggregate and deposit extracellularly in tissues. Nonhereditary apolipoprotein A-I (apoA-I) amyloid is characterized by deposits of nonvariant protein in atherosclerotic arteries. Despite being common, little is known about the pathogenesis and significance of apoA-I deposition. In this work we investigated by fluorescence and biochemical approaches the impact of a cellular microenvironment associated with chronic inflammation on the folding and pro-amyloidogenic processing of apoA-I. Results showed that mildly acidic pH promotes misfolding, aggregation, and increased binding of apoA-I to extracellular matrix elements, thus favoring protein deposition as amyloid like-complexes. In addition, activated neutrophils and oxidative/proteolytic cleavage of the protein give rise to pro amyloidogenic products. We conclude that, even though apoA-I is not inherently amyloidogenic, it may produce non hereditary amyloidosis as a consequence of the pro-inflammatory microenvironment associated to atherogenesis.","pmid":"21811627","doi":"10.1371/journal.pone.0022532","url":"https://pubmed.ncbi.nlm.nih.gov/21811627/"},{"id":1947,"title":"Disinfection methods for spores of Bacillus atrophaeus, B. anthracis, Clostridium tetani, C. botulinum and C. difficile.","authors":"Oie, Shigeharu; Obayashi, Akiko; Yamasaki, Hirofumi; Furukawa, Hiroyuki; Kenri, Tsuyoshi; Takahashi, Motohide; Kawamoto, Keiko; Makino, Sou-ichi","year":2011,"date":"2011","journal":"Biological & pharmaceutical bulletin","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"To evaluate disinfection methods for environments contaminated with bioterrorism-associated microorganism (Bacillus anthracis), we performed the following experiments. First, the sporicidal effects of sodium hypochlorite on spores of five bacterial species were evaluated. Bacillus atrophaeus was the most resistant to hypochlorite, followed in order by B. anthracis, Clostridium botulinum and Clostridium tetani, and Clostridium difficile. Subsequently, using B. atrophaeus spores that were the most resistant to hypochlorite, the sporicidal effects of hypochlorite at lower pH by adding vinegar were evaluated. Hypochlorite containing vinegar had far more marked sporicidal effects than hypochlorite alone. Cleaning with 0.5% (5000 ppm) hypochlorite containing vinegar inactivated B. atrophaeus spores attached to vinyl chloride and plywood plates within 15 s, while that not containing vinegar did not inactivate spores attached to cement or plywood plates even after 1 h. Therefore, the surfaces of cement or plywood plates were covered with gauze soaked in 0.5% hypochlorite containing vinegar, and the sporicidal effects were evaluated. B. atrophaeus spores attached to plywood plates were not inactivated even after 6 h, but those attached to cement plates were inactivated within 5 min. On the other hand, covering the surfaces of plywood plates with gauze soaked in 0.3% peracetic acid and gauze soaked in 2% glutaral inactivated B. atrophaeus spores within 5 min and 6 h, respectively. These results suggest that hypochlorite containing vinegar is effective for disinfecting vinyl chloride, tile, and cement plates contaminated with B. anthracis, and peracetic acid is effective for disinfecting plywood plates contaminated with such microorganism.","pmid":"21804226","doi":"10.1248/bpb.34.1325","url":"https://pubmed.ncbi.nlm.nih.gov/21804226/"},{"id":1949,"title":"Phenylpropanoid and phenylisoprenoid metabolites from Asteraceae species as inhibitors of protein carbonylation.","authors":"Marín, Marta; Giner, Rosa M; Recio, M Carmen; Máñez, Salvador","year":2011,"date":"2011 Oct","journal":"Phytochemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Three phenolic antioxidant and anti-inflammatory compounds: 7-methylaromadendrin, isoprenylhydroquinone glucoside, and 3.5-dicaffeoylquinic acid methyl ester, all isolated from Western Mediterranean Asteraceae species, have been studied for their inhibitory activity against protein carbonylation, a harmful post-translational modification of peptide chains associated with degenerative diseases. All compounds have proven to be effective, with 50% inhibitory concentration (IC₅₀) values in the micromolar range, against bovine serum albumin carbonylation caused by hypochlorite, peroxynitrite, and phorbol ester-induced leukocyte oxidative burst.","pmid":"21762940","doi":"10.1016/j.phytochem.2011.06.005","url":"https://pubmed.ncbi.nlm.nih.gov/21762940/"},{"id":1951,"title":"The effect of a low concentration of hypochlorous acid on rhinovirus infection of nasal epithelial cells.","authors":"Yu, Myeong Sang; Park, Hyung Wook; Kwon, Hyun Ja; Jang, Yong Ju","year":2011,"date":"2011 Jan-Feb","journal":"American journal of rhinology & allergy","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"BACKGROUND: Low concentrations of hypochlorous acid (HOCl) have been shown to exhibit both antibacterial and anti-influenza virus activity, but HOCl still has not been used to kill human rhinovirus (HRV). To model the antiviral effect of nasal irrigation with low-level HOCl in patients with the common cold, we tested the effects of a low concentration of HOCl on HRV infection of primary human nasal epithelial cells (HNEC). METHODS: Cells were infected with HRV for 24 hours and treated with HOCl three times, for 5 minutes each time, at 12 hour intervals. The effects of HOCl on rhinovirus-induced secretion of IL-6 and IL-8 were assessed by ELISA and HRV replication was determined by viral titration. RESULTS: HOCl treatment significantly inhibited HRV-induced secretion of IL-6 and IL-8 and significantly reduced viral titer. The effects of HOCl peaked at 1 minute after HOCl generation and decreased thereafter. CONCLUSION: These in vitro findings indicate that nasal irrigation with low-level HOCl solution may improve clinical symptoms in patients with the common cold.","pmid":"21711976","doi":"10.2500/ajra.2011.25.3545","url":"https://pubmed.ncbi.nlm.nih.gov/21711976/"},{"id":1954,"title":"Influence of pH changes on chlorine-containing endodontic irrigating solutions.","authors":"Rossi-Fedele, G; Guastalli, A R; Doğramacı, E J; Steier, L; De Figueiredo, J A P","year":2011,"date":"2011 Sep","journal":"International endodontic journal","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"Chlorine-containing solutions are used for broad disinfection purposes. Water disinfection literature suggests that their disinfectant action depends on pH values as this will influence the available free chlorine forms. Hypochlorous acid (HOCl) has been suggested to have an antimicrobial effect around 80-100 times stronger than the hypochlorite ion. The aim of this paper was to review the influence of pH changes on the efficacy of chlorine-containing endodontic irrigating solutions. An electronic and hand search (articles published through to 2010, including 'in press' articles; English language; search terms 'root canal irrigants AND sodium hypochlorite or hypochlorous acid or superoxidized water or electrochemically activated solution'; 'antimicrobial action AND sodium hypochlorite or hypochlorous acid or superoxidized water or electrochemically activated solution'; 'tissue dissolution AND sodium hypochlorite or hypochlorous acid or superoxidized water or electrochemically activated solution'; 'smear layer AND sodium hypochlorite or hypochlorous acid or superoxidized water or electrochemically activated solution') was performed to identify publications that compared chlorine water solutions with different pH. Of 1304 publications identified, 20 were considered for inclusion in the review. The search resulted in the retrieval of articles studying sodium hypochlorite (NaOCl), superoxidized waters (SOW) and sodium dichloroisocyanurate (NaDCC). Regarding antimicrobial efficacy, the literature suggested that reducing the pH value of NaOCl to between 6 and 7.5 would lead to improved action; SOW was described as having a lower antimicrobial effect. The tissue dissolution activity NaOCl decreased when the pH reached values between 6 and 7.5; NaDCC and SOW had no clinically relevant tissue dissolution capability. Chlorine solutions of different characteristics appeared to have some cleaning efficacy although they should to be used in conjunction with chelating and/or detergent agents.","pmid":"21658076","doi":"10.1111/j.1365-2591.2011.01911.x","url":"https://pubmed.ncbi.nlm.nih.gov/21658076/"},{"id":1960,"title":"Airway exposure to hypochlorite prior to ovalbumin induces airway hyperreactivity without evidence for allergic sensitization.","authors":"Hox, Valérie; Vanoirbeek, Jeroen A; Callebaut, Ina; Bobic, Sonja; De Vooght, Vanessa; Ceuppens, Jan; Hoet, Peter; Nemery, Benoit; Hellings, Peter W","year":2011,"date":"2011 Jul 28","journal":"Toxicology letters","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"BACKGROUND: Some epidemiologic studies have indicated that attendance to chlorinated swimming pools is associated with airway hyperreactivity (AHR), allergies and asthma. AIM: To investigate the effects of sodium hypochlorite (NaClO), the main pool disinfectant, on allergic sensitization and airway inflammation in mice. METHODS: In a first series of experiments, mice were sensitized to ovalbumin (OVA), followed by OVA aerosols with or without prior nasal instillation of NaClO (3ppm active chlorine). In a second series, naïve mice received 1-7 nasal instillations of OVA, 10min after instillations of NaClO or water. After 1, 3, 5 and 7 exposures airway reactivity to methacholine, cellular inflammation in bronchoalveolar lavage (BAL), serum OVA-specific IgEs and lung Th2 cytokines were measured. RESULTS: In the first mouse model, airway allergy parameters were not significantly altered upon NaClO administration. However in the second model, NaClO exposure prior to OVA did induce AHR, already after 1 combined application. Combined NaClO+OVA exposure did not lead to an influx of inflammatory cells in BAL fluid or production of anti-OVA IgEs. No AHR developed when OVA was heat-denatured, pre-chlorinated, or replaced by bovine serum albumin or lipopolysaccharide. CONCLUSION: Nasal instillation of NaClO prior to OVA induces AHR without allergic sensitization. This response is OVA-specific.","pmid":"21570453","doi":"10.1016/j.toxlet.2011.04.017","url":"https://pubmed.ncbi.nlm.nih.gov/21570453/"},{"id":1962,"title":"Hydrogen [corrected] peroxide-dependent photocytotoxicity by phloxine B, a xanthene-type food colorant.","authors":"Qi, Hang; Takano, Hiroshi; Kato, Yoji; Wu, Qian; Ogata, Chiharu; Zhu, Beiwei; Murata, Yoshiyuki; Nakamura, Yoshimasa","year":2011,"date":"2011 Jul","journal":"Biochimica et biophysica acta","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"BACKGROUND: Phloxine B (PhB; 2',4',5',7'-tetrabromo-4,5,6,7-tetrachloro-fluorescein), an artificial xanthene colorant, has been used as a red coloring agent in drugs and cosmetics as well as foods in some countries. However, little effort has been devoted to the study of this colorant as a potentially useful medicinal agent. METHODS: We investigated the daily light-induced photocytotoxicity of PhB in two human leukemia cells, HL-60 and Jurkat, and its underlying mechanisms by in vitro experiments using antioxidants. REUSLTS AND CONCLUSIONS: PhB inhibited cell proliferation more preferentially to HL-60 cells than to Jurkat cells. Co-treatment of catalase completely blocked the photocytotoxicity by PhB in HL-60 cells, whereas the effect of histidine was only partial, suggesting that hydrogen peroxide (H(2)O(2)), rather than singlet oxygen, might be a prerequisite for the PhB-induced HL-60 cell death. Actually, PhB produced a significant amount of H(2)O(2) in the media as well as in the cells in concentration- and light-dependent manners. Furthermore, methionine, a hypochlorous acid (HOCl) scavenger, also significantly attenuated the cytotoxicity in HL-60 cells, but not in Jurkat cells, indicating the involvement of myeloperoxidase (MPO)-dependent hypohalous acid formation during the photocytotoxicity. In vitro experiments revealed that halogenated tyrosine was generated from the reaction of bovine serum albumin with PhB and HL-60 cell lysate. The present findings suggested that PhB induced a differential photodynamic action in the MPO-containing leukemia cells through an H(2)O(2)-dependent mechanism. GENERAL SIGNIFICANCE: Our findings provide new insights into the molecular mechanisms underlying the PhB-induced apoptosis and also evaluated PhB as a promising PDT agent.","pmid":"21565256","doi":"10.1016/j.bbagen.2011.04.010","url":"https://pubmed.ncbi.nlm.nih.gov/21565256/"},{"id":1967,"title":"4-fluoro-2-methoxyphenol, an apocynin analog with enhanced inhibitory effect on leukocyte oxidant production and phagocytosis.","authors":"de Almeida, Ana Carolina; Cabral Marques, Otávio; Arslanian, Christina; Condino-Neto, Antonio; Ximenes, Valdecir F","year":2011,"date":"2011 Jun 25","journal":"European journal of pharmacology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Apocynin, a methoxy-substituted catechol (4-hydroxy-3-methoxyacetophenone), originally extracted from the roots of Picrorhiza kurroa, has been extensively used as a non-toxic inhibitor of the multienzymatic complex NADPH oxidase. We discovered that the analogous methoxy-substituted catechol, 4-Fluoro-2-methoxyphenol (F-apocynin), in which the acetyl group present in apocynin was changed to a fluorine atom, was significantly more potent as an inhibitor of NADPH oxidase activity, myeloperoxidase (MPO) chlorinating activity and phagocytosis of microorganisms by neutrophils; it was also as potent as apocynin in inhibiting tumor necrosis factor-alpha (TNFα) release by peripheral blood mononuclear cells. We attribute the increased potency of F-apocynin to its increased lipophilicity, which could facilitate the passage of the drug through the cell membrane. The inhibition of MPO chlorination activity, phagocytosis and TNFα release shows that apocynin and F-apocynin actions are not restricted to reactive oxygen species inhibition, but further studies are needed to clarify if these mechanisms are related. Like apocynin, F-apocynin did not show cell toxicity, and is a strong candidate for use in the treatment of inflammatory diseases.","pmid":"21497599","doi":"10.1016/j.ejphar.2011.03.043","url":"https://pubmed.ncbi.nlm.nih.gov/21497599/"},{"id":1971,"title":"Synergistic roles of Helicobacter pylori methionine sulfoxide reductase and GroEL in repairing oxidant-damaged catalase.","authors":"Mahawar, Manish; Tran, ViLinh; Sharp, Joshua S; Maier, Robert J","year":2011,"date":"2011 May 27","journal":"The Journal of biological chemistry","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCl) produced via the enzyme myeloperoxidase is a major antibacterial oxidant produced by neutrophils, and Met residues are considered primary amino acid targets of HOCl damage via conversion to Met sulfoxide. Met sulfoxide can be repaired back to Met by methionine sulfoxide reductase (Msr). Catalase is an important antioxidant enzyme; we show it constitutes 4-5% of the total Helicobacter pylori protein levels. msr and katA strains were about 14- and 4-fold, respectively, more susceptible than the parent to killing by the neutrophil cell line HL-60 cells. Catalase activity of an msr strain was much more reduced by HOCl exposure than for the parental strain. Treatment of pure catalase with HOCl caused oxidation of specific MS-identified Met residues, as well as structural changes and activity loss depending on the oxidant dose. Treatment of catalase with HOCl at a level to limit structural perturbation (at a catalase/HOCl molar ratio of 1:60) resulted in oxidation of six identified Met residues. Msr repaired these residues in an in vitro reconstituted system, but no enzyme activity could be recovered. However, addition of GroEL to the Msr repair mixture significantly enhanced catalase activity recovery. Neutrophils produce large amounts of HOCl at inflammation sites, and bacterial catalase may be a prime target of the host inflammatory response; at high concentrations of HOCl (1:100), we observed loss of catalase secondary structure, oligomerization, and carbonylation. The same HOCl-sensitive Met residue oxidation targets in catalase were detected using chloramine-T as a milder oxidant.","pmid":"21460217","doi":"10.1074/jbc.M111.223677","url":"https://pubmed.ncbi.nlm.nih.gov/21460217/"},{"id":1972,"title":"Development of an Si-rhodamine-based far-red to near-infrared fluorescence probe selective for hypochlorous acid and its applications for biological imaging.","authors":"Koide, Yuichiro; Urano, Yasuteru; Hanaoka, Kenjiro; Terai, Takuya; Nagano, Tetsuo","year":2011,"date":"2011 Apr 20","journal":"Journal of the American Chemical Society","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"A far-red to near-infrared (NIR) fluorescence probe, MMSiR, based on Si-rhodamine, was designed and synthesized for sensitive and selective detection of HOCl in real time. MMSiR and its oxidized product SMSiR have excellent properties, including pH-independence of fluorescence, high resistance to autoxidation and photobleaching, and good tissue penetration of far-red to NIR fluorescence emission. The value of MMSiR was confirmed by real-time imaging of phagocytosis using a fluorescence microscope. wsMMSiR, a more hydrophilic derivative of MMSiR, permitted effective in vivo imaging of HOCl generation in a mouse peritonitis model. This probe is expected to be a useful tool for investigating the wide range of biological functions of HOCl.","pmid":"21443186","doi":"10.1021/ja111470n","url":"https://pubmed.ncbi.nlm.nih.gov/21443186/"},{"id":1975,"title":"Hypochlorite-modified high-density lipoprotein promotes induction of HO-1 in endothelial cells via activation of p42/44 MAPK and zinc finger transcription factor Egr-1.","authors":"Rossmann, Christine; Rauh, Anamaria; Hammer, Astrid; Windischhofer, Werner; Zirkl, Sandra; Sattler, Wolfgang; Malle, Ernst","year":2011,"date":"2011 May 1","journal":"Archives of biochemistry and biophysics","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Modification/chlorination of high-density lipoprotein (HDL) by hypochlorous acid (HOCl), formed by the myeloperoxidase-H₂O₂-chloride system of activated phagocytes, converts an anti-atherogenic lipoprotein into a pro-inflammatory lipoprotein particle. Chlorinated HDL is present in human lesion material, binds to and is internalized by endothelial cells and impairs expression and activity of endothelial nitric oxide synthase. The present study aimed at clarifying whether exposure of endothelial cells to pro-inflammatory HOCl-HDL impacts on expression of heme oxygenase-1, a potential rescue pathway against endothelial dysfunction. Our findings revealed that HDL modified by HOCl, added as reagent or generated enzymatically, induced phosphorylation of p42/44 mitogen-activated protein kinase, expression of transcription factor early growth response-1 (Egr-1) and enhanced expression of heme oxygenase-1 in human endothelial cells. Upregulation of heme oxygenase-1 could be blocked by an inhibitor upstream of p42/44 mitogen-activated protein kinase and/or knockdown of Egr-1 by RNA-interference. Electrophoretic mobility shift assays demonstrated HOCl-HDL-mediated induction of the Egr-1 DNA binding activity. Immunocytochemical and immunoblotting experiments demonstrated HOCl-HDL-induced translocation of Egr-1 to the nucleus. The present study demonstrates a novel compensatory pathway against adverse effects of HOCl-HDL, providing cytoprotection in a number of pathological conditions including cardiovascular disease.","pmid":"21354100","doi":"10.1016/j.abb.2011.02.016","url":"https://pubmed.ncbi.nlm.nih.gov/21354100/"},{"id":1976,"title":"One-electron reduction of N-chlorinated and N-brominated species is a source of radicals and bromine atom formation.","authors":"Pattison, David I; O'Reilly, Robert J; Skaff, Ojia; Radom, Leo; Anderson, Robert F; Davies, Michael J","year":2011,"date":"2011 Mar 21","journal":"Chemical research in toxicology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous (HOCl) and hypobromous (HOBr) acids are strong bactericidal oxidants that are generated by the human immune system but are implicated in the development of many human inflammatory diseases (e.g., atherosclerosis, asthma). These oxidants react readily with sulfur- and nitrogen-containing nucleophiles, with the latter generating N-halogenated species (e.g., chloramines/bromamines (RR'NX; X = Cl, Br)) as initial products. Redox-active metal ions and superoxide radicals (O(2)(•-)) can reduce N-halogenated species to nitrogen- and carbon-centered radicals. N-Halogenated species and O(2)(•-) are generated simultaneously at sites of inflammation, but the significance of their interactions remains unclear. In the present study, rate constants for the reduction of N-halogenated amines, amides, and imides to model potential biological substrates have been determined. Hydrated electrons reduce these species with k(2) > 10(9) M(-1) s(-1), whereas O(2)(•-) reduced only N-halogenated imides with complex kinetics indicative of chain reactions. For N-bromoimides, heterolytic cleavage of the N-Br bond yielded bromine atoms (Br(•)), whereas for other substrates, N-centered radicals and Cl(-)/Br(-) were produced. High-level quantum chemical procedures have been used to calculate gas-phase electron affinities and aqueous solution reduction potentials. The effects of substituents on the electron affinities of aminyl, amidyl, and imidyl radicals are rationalized on the basis of differential effects on the stabilities of the radicals and anions. The calculated reduction potentials are consistent with the experimental observations, with Br(•) production predicted for N-bromosuccinimide, while halide ion formation is predicted in all other cases. These data suggest that interaction of N-halogenated species with O(2)(•-) may produce deleterious N-centered radicals and Br(•).","pmid":"21344936","doi":"10.1021/tx100325z","url":"https://pubmed.ncbi.nlm.nih.gov/21344936/"},{"id":1977,"title":"Efficacy of liquid spray decontaminants for inactivation of Bacillus anthracis spores on building and outdoor materials.","authors":"Wood, J P; Choi, Y W; Rogers, J V; Kelly, T J; Riggs, K B; Willenberg, Z J","year":2011,"date":"2011 May","journal":"Journal of applied microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"AIMS: To obtain data on the efficacy of various liquid and foam decontamination technologies to inactivate Bacillus anthracis Ames and Bacillus subtilis spores on building and outdoor materials. METHODS AND RESULTS: Spores were inoculated onto test coupons and positive control coupons of nine different materials. Six different sporicidal liquids were spray-applied to the test coupons and remained in contact for exposure times ranging from 10 to 70 min. Following decontamination, spores were recovered from the coupons and efficacy was quantified in terms of log reduction. CONCLUSIONS: The hydrogen peroxide/peracetic acid products were the most effective, followed by decontaminants utilizing hypochlorous acid chemistry. Decontamination efficacy varied by material type. SIGNIFICANCE AND IMPACT OF THE STUDY: The study results may be useful in the selection of technologies to decontaminate buildings and outdoor areas in the event of contamination with B. anthracis spores. These results may also facilitate selection of decontaminant liquids for the inactivation of other spore-forming infectious disease agents.","pmid":"21332900","doi":"10.1111/j.1365-2672.2011.04980.x","url":"https://pubmed.ncbi.nlm.nih.gov/21332900/"},{"id":1978,"title":"Kinetics of 3-chlorotyrosine formation and loss due to hypochlorous acid and chloramines.","authors":"Curtis, Matthew P; Hicks, Andrew J; Neidigh, Jonathan W","year":2011,"date":"2011 Mar 21","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The persistent activation of innate immune cells in chronic inflammation is gaining recognition as a contributing factor in a number of human diseases. A distinguishing feature of activated leukocytes at sites of inflammation is their production of reactive species such as hypochlorous acid (HOCl). Investigating the role of reactive molecules such as HOCl in inflammation and human disease requires appropriate biomarkers. The preferred biomarker for HOCl, and by extension its synthesizing enzyme myeloperoxidase, is 3-chlorotyrosine. 3-Chlorotyrosine is a chemically stable product formed when HOCl, or an HOCl-generated chloramine, reacts with the tyrosine side chain and is readily measured by sensitive mass spectrometry methods. However, Whiteman and Spencer ((2008) Biochem. Biophys. Res. Commun., 371, 50 - 53.) noted that 3-chlorotyrosine is degraded by HOCl, calling into question its use as a biomarker. The kinetic rate constants for the reaction of 3-chlorotyrosine with HOCl, histidine chloramine, or lysine chloramine to form 3,5-dichlorotyrosine are reported. The kinetics of tyrosine chlorination in the context of a peptide with a nearby lysine residue was also determined and further supports the role of chloramines in the chlorination of protein-bound tyrosine residues. The likelihood of free and protein-bound 3,5-dichlorotyrosine occurring in vivo, given the reported rate constants, is discussed.","pmid":"21319831","doi":"10.1021/tx100380d","url":"https://pubmed.ncbi.nlm.nih.gov/21319831/"},{"id":1981,"title":"Inhibition of tubulin polymerization by hypochlorous acid and chloramines.","authors":"Landino, Lisa M; Hagedorn, Tara D; Kim, Shannon B; Hogan, Katherine M","year":2011,"date":"2011 Apr 15","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Protein thiol oxidation and modification by nitric oxide and glutathione are emerging as common mechanisms to regulate protein function and to modify protein structure. Also, thiol oxidation is a probable outcome of cellular oxidative stress and is linked to degenerative disease progression. We assessed the effect of the oxidants hypochlorous acid and chloramines on the cytoskeletal protein tubulin. Total cysteine oxidation by the oxidants was monitored by labeling tubulin with the thiol-selective reagent 5-iodoacetamidofluorescein; by reaction with Ellman's reagent, 5,5'-dithiobis(2-nitrobenzoic acid); and by detecting interchain tubulin disulfides by Western blot under nonreducing conditions. Whereas HOCl induced both cysteine and methionine oxidation of tubulin, chloramines were predominantly cysteine oxidants. Cysteine oxidation of tubulin, rather than methionine oxidation, was associated with loss of microtubule polymerization activity, and treatment of oxidized tubulin with disulfide reducing agents restored a considerable portion of the polymerization activity that was lost after oxidation. By comparing the reactivity of hypochlorous acid and chloramines with the previously characterized oxidants, peroxynitrite and the nitroxyl donor Angeli's salt, we have identified tubulin thiol oxidation, not methionine oxidation or tyrosine nitration, as a common outcome responsible for decreased polymerization activity.","pmid":"21256958","doi":"10.1016/j.freeradbiomed.2011.01.018","url":"https://pubmed.ncbi.nlm.nih.gov/21256958/"},{"id":1983,"title":"Hypochlorous and peracetic acid induced oxidation of dairy proteins.","authors":"Kerkaert, Barbara; Mestdagh, Frédéric; Cucu, Tatiana; Aedo, Philip Roger; Ling, Shen Yan; De Meulenaer, Bruno","year":2011,"date":"2011 Feb 9","journal":"Journal of agricultural and food chemistry","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"Hypochlorous and peracetic acids, both known disinfectants in the food industry, were compared for their oxidative capacity toward dairy proteins. Whey proteins and caseins were oxidized under well controlled conditions at pH 8 as a function of the sanitizing concentration. Different markers for protein oxidation were monitored. The results established that the protein carbonyl content was a rather unspecific marker for protein oxidation, which did not allow one to differentiate the oxidant used especially at the lower concentrations. Cysteine, tryptophan, and methionine were proven to be the most vulnerable amino acids for degradation upon hypochlorous and peracetic acid treatment, while tyrosine was only prone to degradation in the presence of hypochlorous acid. Hypochlorous acid induced oxidation gave rise to protein aggregation, while during peracetic acid induced oxidation, no high molecular weight aggregates were observed. Protein aggregation upon hypochlorous acid oxidation could primarily be linked to tryptophan and tyrosine degradation.","pmid":"21214246","doi":"10.1021/jf1037807","url":"https://pubmed.ncbi.nlm.nih.gov/21214246/"},{"id":1984,"title":"Severe hypoxaemia due to methaemoglobinaemia and aspiration pneumonia.","authors":"Mizutani, Tomonori; Hojo, Masayuki","year":2011,"date":"2011 Sep 4","journal":"BMJ case reports","category":"Food & agriculture","evidence":"Case report","relevance":"High","abstract":"The authors report a case of a previously healthy 40-year-old man who was admitted to the emergency department due to severe hypoxaemia after emesis. He vomited after a cup of coffee with the milk at his office. On admission, he showed cyanosis and oxygen saturation measured by pulse oximetry was extremely low (86%) in spite of the administration of 10 litres of oxygen. The authors suspected pneumonia, but oxygen saturation was disproportionately low to pneumonia severity. Oxygen saturation measured by pulse oximetry was significantly different from oxygen saturation calculated from arterial blood gas analysis, suggesting the existence of haemoglobin abnormality. The level of methaemoglobin was 9.3% (reference range, 1-2%). The patient was treated by antibiotics for pneumonia, and his methaemoglobinaemia was spontaneously ameliorated. The authors later found that the patient drank bleach containing hypochlorous acid instead of milk by mistake. To conclude, the patient's hypoxaemia was due to pneumonia and drug-induced acquired methaemoglobinaemia.","pmid":"22679183","doi":"10.1136/bcr.03.2011.3937","url":"https://pubmed.ncbi.nlm.nih.gov/22679183/"},{"id":1986,"title":"Chemical fate and mutagenic formation potentials of phenothiazine and related compounds during water chlorination.","authors":"Sekizawa, Taro; Onodera, Sukeo","year":2010,"date":"2010 Dec","journal":"The Journal of toxicological sciences","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The reactions of hetero-tricyclic aromatic hydrocarbons (H-TCAHs) with hypochlorite in an aqueous solution were investigated under conditions that simulate wastewater disinfection. H-TCAH-hypochlorite reaction products were determined by gas chromatographic-mass spectrometric (GC-MS) analyses. For 20 µM, 10H-phenothiazine, 10H-phenoxazine, and phenoxathiin reacted rapidly with active chlorine in neutral pH (7.0), but no phenazine-hypochlorite reaction was observed over pH values of 5-9 for 1 hr. The 10H-phenothiazine-hypochlorite reaction began by oxidation with active chlorine to form its dioxides, followed by chloro-substitution in water. The extent of the reactions depended on the chlorine dose, solution pH and compound structures. Ames assays for the chlorination byproducts of 10H-phenothiazine and 10H-phenoxazine also showed to be weak mutagenicity in TA98 and TA100 strains without S9 mix, but no chlorination byproducts of phenoxathiin exhibited any mutagenicity in both tester strains with and without S9 mix.","pmid":"21139335","doi":"10.2131/jts.35.853","url":"https://pubmed.ncbi.nlm.nih.gov/21139335/"},{"id":1988,"title":"Kinetic analysis of phagosomal production of reactive oxygen species.","authors":"Tlili, Asma; Dupré-Crochet, Sophie; Erard, Marie; Nüsse, Oliver","year":2011,"date":"2011 Feb 1","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Phagocytes produce large quantities of reactive oxygen species for pathogen killing; however, the kinetics and amplitude of ROS production on the level of individual phagosomes are poorly understood. This is mainly due to the lack of appropriate methods for quantitative ROS detection with microscopic resolution. We covalently attached the ROS-sensitive dye dichlorodihydrofluorescein (DCFH(2)) to yeast particles and investigated their fluorescence due to oxidation in vitro and in live phagocytes. In vitro, the dye was oxidized by H(2)O(2) plus horseradish peroxidase but also by HOCl. The latter produced a previously unrecognized oxidation product with red-shifted excitation and emission spectra and a characteristic difference in the shape of the excitation spectrum near 480 nm. Millimolar HOCl bleached the DCFH(2) oxidation products. Inside phagosomes, DCFH(2)-labeled yeast were oxidized for several minutes in a strictly NADPH oxidase-dependent manner as shown by video microscopy. Inhibition of the NADPH oxidase rapidly stopped the fluorescence increase of the particles. At least two characteristic kinetics of oxidation were distinguished and the variability of DCFH(2) oxidation in phagosomes was much larger than the variability upon oxidation in vitro. We conclude that DCFH(2)-yeast is a valuable tool to investigate the kinetics and amplitude of ROS production in individual phagosomes.","pmid":"21111807","doi":"10.1016/j.freeradbiomed.2010.11.024","url":"https://pubmed.ncbi.nlm.nih.gov/21111807/"},{"id":1990,"title":"Taurine in cardiovascular disease.","authors":"Zulli, Anthony","year":2011,"date":"2011 Jan","journal":"Current opinion in clinical nutrition and metabolic care","category":"Food & agriculture","evidence":"Review","relevance":"High","abstract":"PURPOSE OF REVIEW: The shift of modern dietary regimens from 'Mediterranean' to 'western' style is believed to be responsible, in part, for the increase in cardiovascular disease, obesity, type II diabetes and cancer. A classic 'Mediterranean' diet consists of adequate intake of seafood, vegetables, fruit, whole grain and nonpurified monounsaturated vegetable oil. Thus, in humans, dietary intake of seafood is the major source of taurine, as the level of endogenously produced taurine is low. RECENT FINDINGS: Taurine has been shown to affect coronary artery disease, blood pressure, plasma cholesterol and myocardial function in animal models of human disease. A major role of taurine is to act as an antioxidant and absorb hypochlorous acid but not the oxidative radical. It seems that this beneficial effect of taurine in antioxidant therapy has not been well promoted. SUMMARY: This review will focus on determining whether taurine could be a factor contributing to the further prevention of heart disease.","pmid":"21076292","doi":"10.1097/MCO.0b013e328340d863","url":"https://pubmed.ncbi.nlm.nih.gov/21076292/"},{"id":1991,"title":"Feasibility of an electrochemically assisted Fenton method using Fe(2 +)/HOCl system as an advanced oxidation process.","authors":"Kishimoto, N; Sugimura, E","year":2010,"date":"2010","journal":"Water science and technology : a journal of the International Association on Water Pollution Research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The feasibility of an electrochemically assisted Fenton treatment using a Fenton-type reaction of ferrous iron (Fe(2 + )) and hypochlorous acid (HOCl) is discussed in this research. The reactor used was composed of an undivided single cell with a ruthenium dioxide-coated titanium anode and a stainless steel cathode, in which Fe(2 + ) and HOCl were catalytically regenerated from ferric iron at the cathode and chloride ion at the anode, respectively. Although the reactor functioned well, the degradation rate of 1,4-dioxane as a hydroxyl radical probe decreased at the current density more than 6.92 mA cm(-2). The decrease in degradation rate was inferred to be caused by the vain consumption of hydroxyl radicals by excess HOCl and the deposition of ferric hydroxide on the cathode at relatively high current density. The current efficiency of 1,4-dioxane removal remained more than 90% at the current density less than 6.92 mA cm(-2) and the iron concentration not less than 1.0 mmol L(-1). Consequently, this technique is thought to be applicable to the treatment of wastewater containing high concentration of chloride ion such as landfill leachate, scrubber wastewater from incineration plants, etc.","pmid":"21076218","doi":"10.2166/wst.2010.203","url":"https://pubmed.ncbi.nlm.nih.gov/21076218/"},{"id":1996,"title":"The effect of chlorine-based disinfectant on wettability of a vinyl polysiloxane impression material.","authors":"Blalock, John S; Cooper, Jeril R; Rueggeberg, Frederick A","year":2010,"date":"2010 Nov","journal":"The Journal of prosthetic dentistry","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"STATEMENT OF PROBLEM: Extended contact of impression materials with chemical disinfectant could remove surfactant, significantly altering the contact angle and wettability characteristics of an impression material. PURPOSE: The purpose of this study was to determine the effect of contact time of chemical disinfectant solution on the dynamic contact angle of a commercial vinyl polysiloxsane impression material. MATERIAL AND METHODS: Discs (3.5 × 25 mm) of heavy-body and wash consistencies of material (n=5) were fabricated and either left untreated, or subjected to spray treatment with a commercial disinfectant for various lengths of time (1, 20, or 60 minutes, or 24 hours). Treated specimens were washed and dried, after which dynamic contact angle measurements of a water droplet were determined at various points in time after deposition: 0, 2, 5, 10, 15, and 20 seconds. The same wash product was used without added surfactant (control). For a given type of impression material, contact angles were subjected to 1-way ANOVA within each droplet deposition time for all periods of disinfectant contact (α=.05). The Tukey-Kramer post hoc test was applied for pairwise means comparisons. RESULTS: For each impression material type, significant increases in contact angles were found as the duration of disinfectant contact increased, at each measured droplet deposition time point. For both materials containing surfactant, extended contact with chemical disinfectant resulted in increased contact angles that were not significantly different from those of the nonsurfactant-containing control product. CONCLUSIONS: Increasing the contact time between a surfactant-containing impression material and a disinfecting solution can significantly alter the resulting contact angle of the impression material and render it similar to a material depleted of surfactant. Following manufacturer-recommended chemical disinfection times reduces surfactant loss and only minimally affects surface wettability.","pmid":"20970540","doi":"10.1016/S0022-3913(10)60151-5","url":"https://pubmed.ncbi.nlm.nih.gov/20970540/"},{"id":1999,"title":"Neutrophil- and myeloperoxidase-mediated metabolism of reduced nimesulide: evidence for bioactivation.","authors":"Yang, Min; Chordia, Mahendra D; Li, Fengping; Huang, Tao; Linden, Joel; Macdonald, Timothy L","year":2010,"date":"2010 Nov 15","journal":"Chemical research in toxicology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Nimesulide, a widely used nonsteroidal anti-inflammatory drug (NSAID), has been associated with rare idiosyncratic hepatotoxicity. The chemical mechanisms underlying the liver injury remain unknown. We have undertaken the detailed study of the metabolic pathways of nimesulide in an effort to identify potential reactive metabolites. A previous report from this laboratory has demonstrated that one of the known nimesulide metabolites, termed reduced nimesulide (M1), is further bioactivated by human liver microsomes (HLMs) to form a reactive diiminoquinone species M2. The formation of M2 was confirmed indirectly by trapping with N-acetylcysteine (NAC). The aim of this study was to explore the fate of M1 in an inflammatory environment created by the recruitment of leukocytes. Leukocytes upon activation produce hydrogen peroxide (H(2)O(2)) and other myeloperoxidase (MPO) products, such as hypochlorous acid (HOCl), that are capable of metabolite oxidation. We demonstrate here that the reduced nimesulide, M1, undergoes a facile oxidation with activated neutrophils or with MPO in the presence of H(2)O(2) or HOCl to produce a variety of reactive as well as stable metabolites. One major metabolite, M3, was also produced by HLM as determined by trapping with NAC. Other metabolites, for example, M6, M8, and M9, were unique to the myeloperoxidase, because of their mode of formation from activation of the amino group of reduced nimesulide. The structures of some of these reactive metabolites were proposed on the basis of liquid chromatography-tandem mass spectrometry analyses and established by their comparison with synthetic standards. Metabolite M6 is interesting because it provides clear evidence of amine activation and indicates the potential of the reactive intermediate of M1 to conjugate with protein nucleophiles. In summary, our results demonstrate that a known nimesulide metabolite could be bioactivated by MPO through a pathway distinct from HLM-mediated pathways and that the generation of reactive species by the MPO-mediated bioactivation pathway at the site of inflammation may contribute to the toxicity associated with nimesulide.","pmid":"20939553","doi":"10.1021/tx1001496","url":"https://pubmed.ncbi.nlm.nih.gov/20939553/"},{"id":2003,"title":"RNA interference against CFTR affects HL60-derived neutrophil microbicidal function.","authors":"Bonvillain, Ryan W; Painter, Richard G; Adams, Daniel E; Viswanathan, Anand; Lanson, Nicholas A Jr; Wang, Guoshun","year":2010,"date":"2010 Dec 15","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Biosynthesis of hypochlorous acid, a potent antimicrobial oxidant, in phagosomes is one of the chief mechanisms employed by polymorphonuclear neutrophils to combat infections. This reaction, catalyzed by myeloperoxidase, requires chloride anion (Cl(-)) as a substrate. Thus, Cl(-) availability is a rate-limiting factor that affects neutrophil microbicidal function. Our previous research demonstrated that defective CFTR, a cAMP-activated chloride channel, present in cystic fibrosis (CF) patients leads to deficient chloride transport to neutrophil phagosomes and impaired bacterial killing. To confirm this finding, here we used RNA interference against this chloride channel to abate CFTR expression in the neutrophil-like cells derived from HL60 cells, a promyelocytic leukemia cell line, with dimethyl sulfoxide. The resultant CFTR deficiency in the phagocytes compromised their bactericidal capability, thereby recapitulating the phenotype seen in CF patient cells. The results provide further evidence suggesting that CFTR plays an important role in phagocytic host defense.","pmid":"20870018","doi":"10.1016/j.freeradbiomed.2010.09.012","url":"https://pubmed.ncbi.nlm.nih.gov/20870018/"},{"id":2009,"title":"Microbicidal and cytotoxic effects of functional water in vitro.","authors":"Gomi, Kazuhiro; Makino, Tomohiko; Suzuki, Shinichi; Hasegawa, Masako; Maeda, Nobuko; Arai, Takashi","year":2010,"date":"2010 Oct","journal":"Quintessence international (Berlin, Germany : 1985)","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVE: Several kinds of functional water are used in the fields of food hygiene and medicine. The purpose of this study was to evaluate both the disinfection and cytotoxic effects of functional water in comparison with commonly used root canal irrigants such as sodium hypochlorite solution and hydrogen peroxide solution. METHOD AND MATERIALS: Three kinds of functional water were examined: alkaline electrolysis water (AEW), strong acid electrolyzed water (SAEW), and hypochlorous acid water (HAW). The disinfection effect was studied using Enterococcus faecalis and Candida albicans with or without organic substance. Each kind of functional water was applied to samples, and the colony formation was evaluated. The cytotoxic effect was evaluated by mitogenic assay (MTT) and alkaline phosphatase (ALPase) activity in pulp cells. RESULTS: SAEW and HAW showed microbicidal effects in the presence of organic substance, with an effect almost similar to sodium hypochlorite solution. AEW did not show any microbicidal effect. SAEW, AEW, and HAW at 10- and 1,000-times dilution did not inhibit the MTT assay and ALPase activity. The cytotoxicity of SAEW and HAW against pulp cells was mild compared to that of sodium hypochlorite solution. CONCLUSION: Functional water like SAEW and HAW have a good microbicidal effect under existing organic substance and are also mild to pulp cells.","pmid":"20806093","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/20806093/"},{"id":2010,"title":"Dermacyn irrigation in reducing infection of a median sternotomy wound.","authors":"Mohd, Abdul Ramzisham Rahman; Ghani, Mohd Khairulasri; Awang, Raflis Ruzairee; Su Min, Joanna Ooi; Dimon, Mohd Zamrin","year":2010,"date":"2010 Aug","journal":"The heart surgery forum","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"BACKGROUND: Sternal wound infection is an infrequent yet potentially devastating complication following sternotomy. Among the standard practices used as preventive measures are the use of prophylactic antibiotics and povidone-iodine as an irrigation agent. A new antiseptic agent, Dermacyn super-oxidized water (Oculus Innovative Sciences), has recently been used as a wound-irrigation agent before the closure of sternotomy wounds. METHODS: This prospective, randomized clinical trial was conducted to compare the effectiveness of Dermacyn and povidone-iodine in reducing sternotomy wound infection in patients undergoing coronary artery bypass graft surgery. Upon chest closure and after insertion of sternal wires, wounds were soaked for 15 minutes with either Dermacyn or povidone-iodine. Subcutaneous tissue and skin were then closed routinely. Patients were followed up, and any wound infection was analyzed. RESULTS: Of the 178 patients, 88 patients were in the Dermacyn group, and 90 were in the povidone-iodine group. The mean (+/-SD) age of the patients was 61.1 +/- 7.6 years. The incidence of sternotomy wound infection was 19 cases (10.7%). Five (5.7%) of these cases were from the Dermacyn group, and 14 (15.6%) were from the povidone-iodine group (P = .033). No Dermacyn-related complication was identified. CONCLUSION: We found Dermacyn to be safe and more effective as a wound-irrigation agent than povidone-iodine for preventing sternotomy wound infection.","pmid":"20719724","doi":"10.1532/HSF98.20091162","url":"https://pubmed.ncbi.nlm.nih.gov/20719724/"},{"id":2011,"title":"Lack of cytotoxicity by Trustwater Ecasol™ used to maintain good quality dental unit waterline output water in keratinocyte monolayer and reconstituted human oral epithelial tissue models.","authors":"Boyle, M A; O'Donnell, M J; Russell, R J; Coleman, D C","year":2010,"date":"2010 Nov","journal":"Journal of dentistry","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"We previously showed that residual treatment of dental chair unit (DCU) supply water using the electrochemically-activated solution Trustwater Ecasol™ (2.5 ppm) provided an effective long-term solution to the problem of dental unit waterline (DUWL) biofilm resulting in DUWL output water quality consistently superior to potable water. OBJECTIVES: To investigate the cytoxicity of Ecasol using cultured keratinocyte monolayers and reconstituted human oral epithelial (RHE) tissue and to extend the study of Ecasol's effectiveness in maintaining the microbiological quality of DUWL output water. METHODS: TR146 human keratinocyte monolayers and RHE tissues were exposed to Ecasol (2.5-100 ppm) for 1h periods after removal of growth medium and washing with phosphate-buffered saline (PBS). Experiments were repeated using Ecasol that had been exposed for 30 min to 1-2mg/mL bovine serum albumin (BSA), equivalent to protein concentrations in saliva. To quantitatively determine cytotoxic effects on monolayers following Ecasol exposure, the Alamar Blue proliferation assay (assesses cell viability) and the Trypan Blue exclusion assay (assesses plasma membrane integrity), were used. Cytotoxicity effects on RHE tissues were assessed by the Alamar Blue assay and by histopathology. RESULTS: Ecasol at >5.0 ppm resulted in significant (P<0.001) cytotoxicity to keratinocyte monolayers following a 1h exposure. These effects, however, were completely negated by BSA pretreatment of Ecasol. No cytotoxicity was observed in the more complex RHE tissue at any of the Ecasol concentrations tested. In a 60-week study of 10 DCUs, tested weekly, the average density of aerobic heterotrophic bacteria in Ecasol-treated (2.5 ppm) DCU supply water was <1cfu/mL and in DUWL output water was 6.5cfu/mL. CONCLUSIONS: Ecasol present as a residual disinfectant in DUWL output water is very unlikely to have adverse effects on human oral tissues at levels effective in maintaining DUWL output water quality at better than potable standard water quality.","pmid":"20713118","doi":"10.1016/j.jdent.2010.08.005","url":"https://pubmed.ncbi.nlm.nih.gov/20713118/"},{"id":2015,"title":"Kinetics and mechanism of the reaction of sodium azide with hypochlorite in aqueous solution.","authors":"Betterton, Eric A; Lowry, Joe; Ingamells, Robin; Venner, Brad","year":2010,"date":"2010 Oct 15","journal":"Journal of hazardous materials","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Production of toxic sodium azide (NaN(3)) surged worldwide over the past two decades to meet the demand for automobile air bag inflator propellant. Industrial activity and the return of millions of inflators to automobile recycling facilities are leading to increasing release of NaN(3) to the environment so there is considerable interest in learning more about its environmental fate. Water soluble NaN(3) could conceivably be found in drinking water supplies so here we describe the kinetics and mechanism of the reaction of azide with hypochlorite, which is often used in water treatment plants. The reaction stoichiometry is: HOCl + 2N(3)(-) = 3N(2) + Cl(-) + OH(-), and proceeds by a key intermediate chlorine azide, ClN(3), which subsequently decomposes by reaction with a second azide molecule in the rate determining step: ClN(3) + N(3)(-) --> 3N(2) + Cl(-) (k = 0.52+/-0.04 M(-1) s(-1), 25 degrees C, mu = 0.1 M). We estimate that the half-life of azide would be approximately 15 s at the point of chlorination in a water treatment plant and approximately 24 days at some point downstream where only residual chlorine remains. Hypochlorite is not recommended for treatment of concentrated azide waste due to formation of the toxic chlorine azide intermediate under acidic conditions and the slow kinetics under basic conditions.","pmid":"20667654","doi":"10.1016/j.jhazmat.2010.06.093","url":"https://pubmed.ncbi.nlm.nih.gov/20667654/"},{"id":2016,"title":"Evaluation of Vashe Wound Therapy in the clinical management of patients with chronic wounds.","authors":"Niezgoda, Jeffrey A; Sordi, Peter J; Hermans, Michel H E","year":2010,"date":"2010 Aug","journal":"Advances in skin & wound care","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"OBJECTIVE: To analyze if Vashe Wound Therapy (PuriCore, Malvern, Pennsylvania) is a valuable contribution to standard protocols of wound care. DESIGN: Open, noncomparative study. SETTING: Outpatient clinic. PATIENTS: Thirty-one patients, primarily with venous or mixed venous/arterial leg ulcers. INTERVENTIONS: Vashe Wound Therapy (hypochlorous acid, produced on site and on demand) was used as an adjunct to a standard wound care protocol. MAIN OUTCOME MEASURES: Wound healing, reduction of pain, and odor. MAIN RESULTS: At the end of the study, 86% of all lesions healed, and the average size of reduction in nonhealed wounds was 47%. Odor was present at the beginning of enrollment in 21 patients and was rated 4.58 on the visual analog scale. In all patients, the odor score at end of treatment was zero. Seventy-seven percent of all patients reported a positive pain score at the beginning of participation in the evaluation (average pain score, 4.7). At the end of the study, no patient experienced pain. CONCLUSION: Vashe Wound Therapy is a valuable contribution to standard protocols of wound care.","pmid":"20664326","doi":"10.1097/01.ASW.0000383198.35815.a2","url":"https://pubmed.ncbi.nlm.nih.gov/20664326/"},{"id":2017,"title":"Conventional oxidation treatments for the removal of arsenic with chlorine dioxide, hypochlorite, potassium permanganate and monochloramine.","authors":"Sorlini, Sabrina; Gialdini, Francesca","year":2010,"date":"2010 Nov","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Arsenic is widespread in soils, water and air. In natural water the main forms are arsenite (As(III)) and arsenate (As(V)). The consumption of water containing high concentration of arsenic produces serious effects on human health, like skin and lung cancer. In Italy, Legislative Decree 2001/31 reduced the limit of arsenic from 50 to 10 μg/L, in agreement with the European Directive 98/83/EC. As consequence, many drinking water treatment plant companies needed to upgrade the existing plants where arsenic was previously removed or to build up new plants for arsenic removal when this contaminant was not previously a critical parameter. Arsenic removal from water may occur through the precipitation with iron or aluminum salts, adsorption on iron hydroxide or granular activated alumina (AA), reverse osmosis and ion exchange (IE). Some of the above techniques, especially precipitation, adsorption with AA and IE, can reach good arsenic removal yields only if arsenic is oxidized. The aim of the present work is to investigate the efficiency of the oxidation of As(III) by means of four conventional oxidants (chlorine dioxide, sodium hypochlorite, potassium permanganate and monochloramine) with different test conditions: different type of water (demineralised and real water), different pH values (5.7-6-7 and 8) and different doses of chemicals. The arsenic oxidation yields were excellent with potassium permanganate, very good with hypochlorite and low with monochloramine. These results were observed both on demineralised and real water for all the tested reagents with the exception of chlorine dioxide that showed a better arsenic oxidation on real groundwater than demineralised water.","pmid":"20638704","doi":"10.1016/j.watres.2010.06.032","url":"https://pubmed.ncbi.nlm.nih.gov/20638704/"},{"id":2018,"title":"Ability of hypochlorous acid and N-chloramines to chlorinate DNA and its constituents.","authors":"Stanley, Naomi R; Pattison, David I; Hawkins, Clare L","year":2010,"date":"2010 Jul 19","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase is a heme enzyme released by activated phagocytes that is responsible for the generation of the strong oxidant hypochlorous acid (HOCl). Although HOCl has potent bactericidal properties and plays an important role in the human immune system, this oxidant also causes damage to tissues, particularly under inflammatory conditions. There is a strong link between chronic inflammation and the incidence of many cancers, which may be associated with the ability of HOCl and related oxidants such as N-chloramines to damage DNA. However, in contrast to HOCl, little is known about the reactivity of N-chloramines with DNA and its constituents. In this study, we examine the ability of HOCl and various N-chloramines to form chlorinated base products on nucleosides, nucleotides, DNA, and in cellular systems. Experiments were performed with N-chloramines formed on Nalpha-acetyl-histidine (His-C), Nalpha-acetyl-lysine (Lys-C), glycine (Gly-C), taurine (Tau-C), and ammonia (Mono-C). Treatment of DNA and related materials with HOCl and His-C resulted in the formation of 5-chloro-2'-deoxycytidine (5CldC), 8-chloro-2'-deoxyadenosine (8CldA) and 8-chloro-2'-deoxyguanosine (8CldG). With the nucleosides, 8CldG was the favored product in each case, and HOCl was the most efficient chlorinating agent. 5Cl(d)C was the most abundant product on exposure of the nucleotides and DNA to HOCl and His-C, with only low levels of chlorinated products observed with Lys-C, Gly-C, Tau-C, and Mono-C. 5CldC was also formed on exposure of smooth muscle cells to either HOCl or His-C. Cellular RNA was also a target for HOCl and His-C, with evidence for the formation of 5-chloro-cytidine (5ClC). This study shows that HOCl and the model N-chloramine, His-C, are able to chlorinate cellular genetic material, which may play a role in the development of various inflammatory cancers.","pmid":"20593802","doi":"10.1021/tx100188b","url":"https://pubmed.ncbi.nlm.nih.gov/20593802/"},{"id":2022,"title":"Antimicrobial effects of hypochlorite on Escherichia coli in water and selected vegetables.","authors":"Erkmen, Osman","year":2010,"date":"2010 Aug","journal":"Foodborne pathogens and disease","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"In this study, the antimicrobial effects of hypochlorite (HOCl) on Escherichia coli in tap water were investigated. The effects of 0.1% thyme oil and 100 mg/L HOCl on E. coli on vegetables (lettuce, parsley leafs, and red pepper) were also studied. E. coli was reduced by 2.54, 3.33, 3.93, 4.87, and 5.57 log colony forming units (cfu)/mL with 0.25, 0.5, 1.0, 10, and 50 mg/mL HOCl, respectively. There was an increase of more than 30% in the inactivation of E. coli with 10 degrees C rise in temperature, a remarkable increase in antimicrobial activity at pH 5.0 was also observed with 5.62 log cfu/mL reductions in 30 sec, as well as marked neutralization of the effect in the presence of 0.1% peptone in water was noted. Biphasic kinetics in the inactivation curves of E. coli was observed. HOCl, thyme oil, and their mixture reduced the number of E. coli between 1.23 and 3.75 log cfu/mL after 5-min exposure on vegetables. The degree of E. coli inactivation depends on concentration of residual chlorine, suspending medium, type of vegetables, and the use of thyme essential oil.","pmid":"20524899","doi":"10.1089/fpd.2009.0509","url":"https://pubmed.ncbi.nlm.nih.gov/20524899/"},{"id":2026,"title":"Use of propidium monoazide in reverse transcriptase PCR to distinguish between infectious and noninfectious enteric viruses in water samples.","authors":"Parshionikar, Sandhya; Laseke, Ian; Fout, G Shay","year":2010,"date":"2010 Jul","journal":"Applied and environmental microbiology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Human enteric viruses can be present in untreated and inadequately treated drinking water. Molecular methods, such as the reverse transcriptase PCR (RT-PCR), can detect viral genomes in a few hours, but they cannot distinguish between infectious and noninfectious viruses. Since only infectious viruses are a public health concern, methods that not only are rapid but also provide information on the infectivity of viruses are of interest. The intercalating dye propidium monoazide (PMA) has been used for distinguishing between viable and nonviable bacteria with DNA genomes, but it has not been used to distinguish between infectious and noninfectious enteric viruses with RNA genomes. In this study, PMA in conjunction with RT-PCR (PMA-RT-PCR) was used to determine the infectivity of enteric RNA viruses in water. Coxsackievirus, poliovirus, echovirus, and Norwalk virus were rendered noninfectious or inactivated by treatment with heat (72 degrees C, 37 degrees C, and 19 degrees C) or hypochlorite. Infectious or native and noninfectious or inactivated viruses were treated with PMA. This was followed by RNA extraction and RT-PCR or quantitative RT-PCR (qRT-PCR) analysis. The PMA-RT-PCR results indicated that PMA treatment did not interfere with detection of infectious or native viruses but prevented detection of noninfectious or inactivated viruses that were rendered noninfectious or inactivated by treatment at 72 degrees C and 37 degrees C and by hypochlorite treatment. However, PMA-RT-PCR was unable to prevent detection of enteroviruses that were rendered noninfectious by treatment at 19 degrees C. After PMA treatment poliovirus that was rendered noninfectious by treatment at 37 degrees C was undetectable by qRT-PCR, but PMA treatment did not affect detection of Norwalk virus. PMA-RT-PCR was also shown to be effective for detecting infectious poliovirus in the presence of noninfectious virus and in an environmental matrix. We concluded that PMA can be used to differentiate between potentially infectious and noninfectious viruses under the conditions defined above.","pmid":"20472736","doi":"10.1128/AEM.02800-09","url":"https://pubmed.ncbi.nlm.nih.gov/20472736/"},{"id":2029,"title":"Myeloperoxidase-induced genomic DNA-centered radicals.","authors":"Gomez-Mejiba, Sandra E; Zhai, Zili; Gimenez, Maria S; Ashby, Michael T; Chilakapati, Jaya; Kitchin, Kirk; Mason, Ronald P; Ramirez, Dario C","year":2010,"date":"2010 Jun 25","journal":"The Journal of biological chemistry","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Myeloperoxidase (MPO) released by activated neutrophils can initiate and promote carcinogenesis. MPO produces hypochlorous acid (HOCl) that oxidizes the genomic DNA in inflammatory cells as well as in surrounding epithelial cells. DNA-centered radicals are early intermediates formed during DNA oxidation. Once formed, DNA-centered radicals decay by mechanisms that are not completely understood, producing a number of oxidation products that are studied as markers of DNA oxidation. In this study we employed the 5,5-dimethyl-1-pyrroline N-oxide-based immuno-spin trapping technique to investigate the MPO-triggered formation of DNA-centered radicals in inflammatory and epithelial cells and to test whether resveratrol blocks HOCl-induced DNA-centered radical formation in these cells. We found that HOCl added exogenously or generated intracellularly by MPO that has been taken up by the cell or by MPO newly synthesized produces DNA-centered radicals inside cells. We also found that resveratrol passed across cell membranes and scavenged HOCl before it reacted with the genomic DNA, thus blocking DNA-centered radical formation. Taken together our results indicate that the formation of DNA-centered radicals by intracellular MPO may be a useful point of therapeutic intervention in inflammation-induced carcinogenesis.","pmid":"20406811","doi":"10.1074/jbc.M109.086579","url":"https://pubmed.ncbi.nlm.nih.gov/20406811/"},{"id":2034,"title":"Computational studies on metathetical and redox processes of HOCl in gas phase. III. Its self-reaction and interactions with HNOx (x = 1-3).","authors":"Xu, Z F; Lin, M C","year":2010,"date":"2010 Apr 29","journal":"The journal of physical chemistry. A","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The gas-phase redox reactions of HOCl with its self and HNO(x) (x = 1-3) have been studied theoretically by ab initio quantum chemical and statistical mechanical theories. The structures of reactants, intermediate complexes, products, and transition states were optimized at the MPW1PW91/6-311+G(3df,2p) level of theory. The potential energy surface of each reaction was refined at the CCSD(T)/6-311+G(3df,2p) level of theory. The most favorable products are predicted to be ClClO + H(2)O and ClOCl + H(2)O for the HOCl self-reaction (A), H(2)O + Cl + NO for the HOCl + HNO reaction (B), H(2)O + ClNO(2) for the HOCl + HONO-t reaction (C), H(2)O + cis-ClONO for the HOCl + HONO-c reaction (D). For the HOCl + HONO(2) reaction (E), only one dehydration reaction channel was considered to produce H(2)O + ClONO(2). The rate constants of all above five reactions have been predicted at 300-3000 K by the VTST/RRKM theory. The calculation shows that the theoretical rate constants are within the upper limits of experimental results. In addition, we calculated the equilibrium constant for the Cl(2)O + H(2)O --> HOCl + HOCl reaction, which is also in reasonable agreement with experimental data within the error of the available experimental enthalpy change.","pmid":"20361765","doi":"10.1021/jp100977k","url":"https://pubmed.ncbi.nlm.nih.gov/20361765/"},{"id":2036,"title":"Occurrence of bromate, chlorite and chlorate in drinking waters disinfected with hypochlorite reagents. Tracing their origins.","authors":"Garcia-Villanova, Rafael J; Oliveira Dantas Leite, M Vilani; Hernández Hierro, J Miguel; de Castro Alfageme, Santiago; García Hernández, Cristina","year":2010,"date":"2010 May 15","journal":"The Science of the total environment","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Bromate was first reported as a disinfection by-product from ozonated waters, but more recently it has been reported also as a result of treatment using hypochlorite solutions worldwide. The aim of this study was to study the scope of this phenomenon in the drinking waters (n=509) of Castilla y León, Spain, and in the hypochlorite disinfectant reagents. Two thirds of the treated waters monitored were found to have bromate concentrations higher than 1 microg/l, and of them a median value of 8 microg/l and a maximum of 49 microg/l. These concentrations are higher than those reported so far, however, a great variability can be found. Median values for chlorite were of 5 microg/l, and of 119 microg/l for chlorate. Only 7 out of 40 hypochlorite feedstock solutions were negative for bromate, the rest showing a median of 1022 mg/l; and 4 out of 14 calcium hypochlorite pellets were also negative, the rest with a median of 240 mg/kg. Although bromate is cited as potentially added to water from calcium hypochlorite pellets, no reference is found in scientific literature regarding its real content. Chlorite (median 2646 mg/l) and chlorate (median 20,462 mg/l) and chlorite (median 695 mg/kg) and chlorate (median 9516 mg/kg) were also monitored, respectively, in sodium hypochlorite solutions and calcium hypochlorite pellets. The levels of chlorite and chlorate in water are considered satisfactory, but not those of bromate, undoubtedly owing to the high content of bromide in the raw brines employed by the chlor-alkali manufacturers. Depending on the manufacturer, the bromate concentrations in the treated waters may be very heterogeneous owing to the lack of specification for this contaminant in the disinfectant reagents -the European Norms EN 900 and 901 do not mention it.","pmid":"20347118","doi":"10.1016/j.scitotenv.2010.03.011","url":"https://pubmed.ncbi.nlm.nih.gov/20347118/"},{"id":2038,"title":"Diaphragm tension reduced in dystrophic mice by an oxidant, hypochlorous acid.","authors":"Lafoux, Aude; Divet, Alexandra; Gervier, Pascal; Huchet-Cadiou, Corinne","year":2010,"date":"2010 Feb","journal":"Canadian journal of physiology and pharmacology","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"In dystrophin-deficient skeletal muscle cells, in which Ca2+ homeostasis is disrupted and reactive oxygen species production is increased, we hypothesized that hypochlorous acid (HOCl), a strong H2O2-related free radical, damages contractile proteins and the sarcoplasmic reticulum. The aim of the present study was to investigate the effects of exposure to oxidative stress, generated by applying HOCl (100 micromol/L and 1 mmol/L), on the contractile function and sarcoplasmic reticulum properties of dystrophic mice. Experiments were performed on diaphragm muscle, which is severely affected in the mdx mouse, and the results were compared with those obtained in healthy (non-dystrophic) mice. In Triton-skinned fibres from C57BL/10 and mdx mice, 1 mmol/L HOCl increased myofibrillar Ca2+ sensitivity, but decreased maximal Ca2+-activated tension. In the presence of HOCl, higher concentrations of MgATP were required to produce rigor tensions. The interaction between HOCl and the Ca2+ uptake mechanisms was demonstrated using saponin-skinned fibres and sarcoplasmic reticulum vesicles. The results showed that HOCl, at micromolar or millimolar concentrations, can modify sarcoplasmic reticulum Ca2+ uptake and that this effect was more pronounced in diaphragm muscle from mdx mice. We conclude that in dystrophic diaphragm skeletal muscle cells, HOCl activates a cellular pathway that leads to an increase in the intracellular concentration of Ca2+.","pmid":"20237587","doi":"10.1139/Y09-117","url":"https://pubmed.ncbi.nlm.nih.gov/20237587/"},{"id":2043,"title":"Estimation of antioxidant capacity against peroxynitrite and hypochlorite with fluorescein.","authors":"Robaszkiewicz, Agnieszka; Bartosz, Grzegorz","year":2010,"date":"2010 Mar 15","journal":"Talanta","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Peroxynitrite and hypochlorite are oxidants relevant in many pathological situations. We propose a simple spectrofluorometric assay to determine antioxidant capacity against hypochlorite and peroxynitrite based on protection against fluorescein bleaching. The assay can be performed on a microplate and requires minute amounts of material. Standard antioxidants show different reactivities for both oxidants. Antioxidant capacity of fruit bodies of edible mushrooms, tea, coffee and wine estimated as exemplary biological material point to considerable differences in the scavenging capacity of various biological material against hypochlorite, peroxynitrite and peroxyl radicals.","pmid":"20152473","doi":"10.1016/j.talanta.2009.11.004","url":"https://pubmed.ncbi.nlm.nih.gov/20152473/"},{"id":2048,"title":"Small molecular, macromolecular, and cellular chloramines react with thiocyanate to give the human defense factor hypothiocyanite.","authors":"Xulu, Bheki A; Ashby, Michael T","year":2010,"date":"2010 Mar 9","journal":"Biochemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Thiocyanate reacts noncatalytically with myeloperoxidase-derived HOCl to produce hypothiocyanite (OSCN(-)), thereby potentially limiting the propensity of HOCl to inflict host tissue damage that can lead to inflammatory diseases. However, the efficiency with which SCN(-) captures HOCl in vivo depends on the concentration of SCN(-) relative to other chemical targets. In blood plasma, where the concentration of SCN(-) is relatively low, proteins may be the principal initial targets of HOCl, and chloramines are a significant product. Chloramines eventually decompose to irreversibly damage proteins. In the present study, we demonstrate that SCN(-) reacts efficiently with chloramines in small molecules, in proteins, and in Escherichia coli cells to give OSCN(-) and the parent amine. Remarkably, OSCN(-) reacts faster than SCN(-) with chloramines. These reactions of SCN(-) and OSCN(-) with chloramines may repair some of the damage that is inflicted on protein amines by HOCl. Our observations are further evidence for the importance of secondary reactions during the redox cascades that are associated with oxidative stress by hypohalous acids.","pmid":"20085320","doi":"10.1021/bi902089w","url":"https://pubmed.ncbi.nlm.nih.gov/20085320/"},{"id":2053,"title":"Hypochlorite oxidation of select androgenic steroids.","authors":"Mash, Heath; Schenck, Kathleen; Rosenblum, Laura","year":2010,"date":"2010 Mar","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Steroid hormones are vital for regulation of various biological functions including sexual development. Elevated concentrations of natural and synthetic androgenic steroids have been shown to adversely affect normal development in indigenous aqueous species. Androgens and their synthetic analogs released from agricultural activities and wastewater discharge may be introduced into drinking water sources. The fate of androgenic steroids during drinking water treatment, specifically the use of chlorine for biological control, has not been extensively studied. As such, this study focuses on the hypochlorite oxidation of a select number of androgenic compounds that vary in their structural composition. Where a favorable reaction is observed, we also attempt to describe the product distribution. The results show compounds that possess a ketonic functional group conjugated with a double bond inhibit oxidation by hypochlorite in the absence of biological or indirect oxidative pathways. Oxidative reactivity in the presence of hypochlorite was favorably correlated with the presence of isolated unsaturated carbon bonds and resulted in various transformation products.","pmid":"20031185","doi":"10.1016/j.watres.2009.11.051","url":"https://pubmed.ncbi.nlm.nih.gov/20031185/"},{"id":2061,"title":"HOCl-mediated glycerophosphocholine and glycerophosphoethanolamine generation from plasmalogens in phospholipid mixtures.","authors":"Lessig, Jacqueline; Fuchs, Beate","year":2010,"date":"2010 Jan","journal":"Lipids","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Many mammalian tissues and cells contain, in addition to (diacyl) phospholipids, considerable amounts of plasmalogens, which may function as important antioxidants. Apart from the \"scavenger\" function mediated by the high sensitivity of the vinyl-ether bond, the functional role of plasmalogens is so far widely unknown. Furthermore, there is increasing evidence that plasmalogen degradation products have harmful effects in inflammatory processes. In a previous investigation glycerophosphocholine (GPC) formation was verified as a novel plasmalogen degradation pathway upon oxidation with hypochlorous acid (HOCl), however these investigations were performed in simple model systems. Herein, we examine plasmalogen degradation in a more complex system in order to evaluate if GPC generation is also a major pathway in the presence of other highly unsaturated glycerophospholipids (GPL) representing an additional reaction site of HOCl targets. Using MALDI-TOF mass spectrometry and (31)P NMR spectroscopy, we confirmed that the first step of the HOCl-induced degradation of GPL mixtures containing plasmalogens is the attack of the vinyl-ether bond resulting in the generation of 1-lysophosphatidylcholine (lysoPtdCho) or 1-lysophosphatidylethanolamine. In the second step HOCl reacts with the fatty acyl residue in the sn-2 position of 1-lysoPtdCho. This reaction is about three times faster in comparison to comparable diacyl-GPL. Thus, the generation of GPC and glycerophosphoethanolamine (GPE) from plasmalogens are relevant products formed from HOCl attack on the vinyl-ether bond of plasmalogens under pathological conditions.","pmid":"19937395","doi":"10.1007/s11745-009-3365-8","url":"https://pubmed.ncbi.nlm.nih.gov/19937395/"},{"id":2064,"title":"Chloramination of organophosphorus pesticides found in drinking water sources.","authors":"Duirk, Stephen E; Desetto, Lisa M; Davis, Gary M; Lindell, Cristal; Cornelison, Christopher T","year":2010,"date":"2010 Feb","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The degradation of commonly detected organophosphorus (OP) pesticides, in drinking water sources, was investigated under simulated chloramination conditions. Due to monochloramine autodecomposition, it is difficult to observe the direct reaction of monochloramine with each OP pesticide. Therefore, a model was developed to examine the reaction of monochloramine (NH(2)Cl) and dichloramine (NHCl(2)) with chlorpyrifos (CP), diazinon (DZ), and malathion (MA). Monochloramine was found not to be very reactive with each OP pesticides, (k)NH(2)Cl,OP = 11-21 M(-1)h(-1). While, dichloramine (NHCl(2)) was found to be 2 orders of magnitude more reactive with each of the OP pesticides than monochloramine, (k)NHCl(2),OP = 2000-2900 M(-1)h(-1), which is still three orders of magnitude less than the hypochlorous acid reaction rate coefficient with each OP pesticide. For each pesticide, the reactivity of the three chlorinated oxidants was then found to correlate with half-wave potentials (E(1/2)) of each oxidant. With reaction rate coefficients for the three chlorinated oxidations as well as neutral and alkaline hydrolysis rate coefficients for the pesticides, the model was used to determine the dominant reaction pathways as a function of pH. At pH 6.5, OP pesticide transformation was mostly due to the reaction of hypochlorous acid and dichloramine. Above pH 8, alkaline hydrolysis or the direct reaction with monochloramine was the primary degradation pathway responsible for the transformation of OP pesticides. This demonstrates the ability of models to be used as tools to elucidate degradation pathways and parameterize critical reaction parameters when used with select yet comprehensive data sets.","pmid":"19900689","doi":"10.1016/j.watres.2009.10.012","url":"https://pubmed.ncbi.nlm.nih.gov/19900689/"},{"id":2066,"title":"Comparative study of HOCl-inflicted damage to bacterial DNA ex vivo and within cells.","authors":"Suquet, Christine; Warren, Jeffrey J; Seth, Nimulrith; Hurst, James K","year":2010,"date":"2010 Jan 15","journal":"Archives of biochemistry and biophysics","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The prospects for using bacterial DNA as an intrinsic probe for HOCl and secondary oxidants/chlorinating agents associated with it has been evaluated using both in vitro and in vivo studies. Single-strand and double-strand breaks occurred in bare plasmid DNA that had been exposed to high levels of HOCl, although these reactions were very inefficient compared to polynucleotide chain cleavage caused by the OH.-generating reagent, peroxynitrite. Plasmid nicking was not increased when intact Escherichia coli were exposed to HOCl; rather, the amount of recoverable plasmid diminished in a dose-dependent manner. At concentration levels of HOCl exceeding lethal doses, genomic bacterial DNA underwent extensive fragmentation and the amount of precipitable DNA-protein complexes increased several-fold. The 5-chlorocytosine content of plasmid and genomic DNA isolated from HOCl-exposed E. coli was also slightly elevated above controls, as measured by mass spectrometry of the deaminated product, 5-chlorouracil. However, the yields were not dose-dependent over the bactericidal concentration range. Genomic DNA recovered from E. coli that had been subjected to phagocytosis by human neutrophils occasionally showed small increases in 5-chlorocytosine content when compared to analogous cellular reactions where myeloperoxidase activity was inhibited by azide ion. Overall, the amount of isolable 5-chlorouracil from the HOCl-exposed bacterial cells was far less than the damage manifested in polynucleotide bond cleavage and cross-linking.","pmid":"19850004","doi":"10.1016/j.abb.2009.10.006","url":"https://pubmed.ncbi.nlm.nih.gov/19850004/"},{"id":2067,"title":"Hypochlorous acid reacts with the N-terminal methionines of proteins to give dehydromethionine, a potential biomarker for neutrophil-induced oxidative stress.","authors":"Beal, Jennifer L; Foster, Steven B; Ashby, Michael T","year":2009,"date":"2009 Nov 24","journal":"Biochemistry","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Electrophilic halogenating agents, including hypohalous acids and haloamines, oxidize free methionine and the N-terminal methionines of peptides and proteins (e.g., Met-1 of anti-inflammatory peptide 1 and ubiquitin) to produce dehydromethionine (a five-membered isothiazolidinium heterocycle). Amide derivatives of methionine are oxidized to the corresponding sulfoxide derivatives under the same reaction conditions (e.g., Met-3 of anti-inflammatory peptide 1). Other biological oxidants, including hydrogen peroxide and peroxynitrite, also produce only the corresponding sulfoxides. Hypothiocyanite does not react with methionine residues. We suggest that dehydromethionine may be a useful biomarker for the myeloperoxidase-induced oxidative stress associated with many inflammatory diseases.","pmid":"19839600","doi":"10.1021/bi901343d","url":"https://pubmed.ncbi.nlm.nih.gov/19839600/"},{"id":2068,"title":"Mitigation of Alicyclobacillus spp. spores on food contact surfaces with aqueous chlorine dioxide and hypochlorite.","authors":"Friedrich, Loretta M; Goodrich-Schneider, Renee; Parish, Mickey E; Danyluk, Michelle D","year":2009,"date":"2009 Dec","journal":"Food microbiology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The prevalence of Alicyclobacillus spp. and other spore-forming spoilage organisms in food handling and processing environments presents a sanitation challenge to manufacturers of products such as juices and beverages. The objectives of this study were to determine the efficacy of chlorine dioxide and sodium hypochlorite in killing Alicyclobacillus spores in situ and to evaluate the efficacy of various chlorine dioxide and hypochlorite sanitizing regimes on Alicyclobacillus spp. spores on stainless steel, wood, and rubber conveyor material. Five or two log CFU/ml spore concentrations were left in aqueous solution or inoculated onto stainless steel, rubber, or wood coupons and challenged with sanitizer for varied time intervals. After treatment, the coupons were placed in sterile sample bags, massaged with neutralizing buffer, and enumerated on Ali agar. Surfaces were also examined before and after treatment by scanning electron microscopy to confirm destruction or removal of the spores. For both five and two log CFU/ml spore concentrations, treatments of 50 and 100 ppm of chlorine dioxide and 1000 and 2000 ppm of hypochlorite, respectively, were the most effective. Of the range of chlorine dioxide concentrations and contact time regimes evaluated for all surfaces, the most effective concentration/time regime applied was 100 ppm for 10 min. Reductions ranged from 0 to 4.5 log CFU/coupon. Chlorine dioxide was least effective when applied to wood. Hypochlorite was not efficient at eliminating Alicyclobacillus spores from any of the food contact surfaces at any time and concentration combinations tested. Chlorine dioxide is an alternative treatment to kill spores of Alicyclobacillus spp. in the processing environment.","pmid":"19835785","doi":"10.1016/j.fm.2009.06.011","url":"https://pubmed.ncbi.nlm.nih.gov/19835785/"},{"id":2069,"title":"Methionine oxidation contributes to bacterial killing by the myeloperoxidase system of neutrophils.","authors":"Rosen, Henry; Klebanoff, Seymour J; Wang, Yi; Brot, Nathan; Heinecke, Jay W; Fu, Xiaoyun","year":2009,"date":"2009 Nov 3","journal":"Proceedings of the National Academy of Sciences of the United States of America","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Reactive oxygen intermediates generated by neutrophils kill bacteria and are implicated in inflammatory tissue injury, but precise molecular targets are undefined. We demonstrate that neutrophils use myeloperoxidase (MPO) to convert methionine residues of ingested Escherichia coli to methionine sulfoxide in high yield. Neutrophils deficient in individual components of the MPO system (MPO, H(2)O(2), chloride) exhibited impaired bactericidal activity and impaired capacity to oxidize methionine. HOCl, the principal physiologic product of the MPO system, is a highly efficient oxidant for methionine, and its microbicidal effects were found to correspond linearly with oxidation of methionine residues in bacterial cytosolic and inner membrane proteins. In contrast, outer envelope proteins were initially oxidized without associated microbicidal effect. Disruption of bacterial methionine sulfoxide repair systems rendered E. coli more susceptible to killing by HOCl, whereas over-expression of a repair enzyme, methionine sulfoxide reductase A, rendered them resistant, suggesting a direct role for methionine oxidation in bactericidal activity. Prominent among oxidized bacterial proteins were those engaged in synthesis and translocation of peptides to the cell envelope, an essential physiological function. Moreover, HOCl impaired protein translocation early in the course of bacterial killing. Together, our findings indicate that MPO-mediated methionine oxidation contributes to bacterial killing by neutrophils. The findings further suggest that protein translocation to the cell envelope is one important pathway targeted for damage.","pmid":"19833874","doi":"10.1073/pnas.0909464106","url":"https://pubmed.ncbi.nlm.nih.gov/19833874/"},{"id":2075,"title":"Site-specific hypochlorous acid-induced oxidation of recombinant human myoglobin affects specific amino acid residues and the rate of cytochrome b5-mediated heme reduction.","authors":"Szuchman-Sapir, Andrea J; Pattison, David I; Davies, Michael J; Witting, Paul K","year":2010,"date":"2010 Jan 1","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase catalyzes the reaction of chloride ions with H(2)O(2) to yield hypochlorous acid (HOCl), which can damage proteins. Human myoglobin (HMb) differs from other Mbs by the presence of a cysteine residue at position 110 (Cys110). This study has (i) compared wild-type and a Cys110Ala variant of HMb to assess the influence of Cys110 on HOCl-induced amino acid modification and (ii) determined whether HOCl oxidation of HMb affects the rate of ferric heme reduction by cytochrome b(5). For wild-type HMb (HOCl:Mb ratio of 5:1 mol:mol), Cys110 was preferentially oxidized to a homodimeric or cysteic acid product-sulfenic/sulfinic acids were not detected. At a HOCl:Mb ratio 10:1 mol:mol, methionine (Met) oxidation was detected, and this was enhanced in the Cys110Ala variant. Tryptophan (Trp) oxidation was detected only in the Cys110Ala variant at the highest HOCl dose tested, with oxidation susceptibility following the order Cys>Met>Trp. Tyrosine chlorination was evident only in reactions between HOCl and the Cys110Ala variant and at a longer incubation time (24 h), consistent with the formation via chlorine-transfer reactions from preformed chloramines. HOCl-mediated oxidation of wild-type HMb resulted in a dose-dependent decrease in the observed rate constant for ferric heme reduction (approx two-fold at HOCl:Mb of 10:1 mol:mol). These data indicate that Cys110 influences the oxidation of HMb by HOCl and that oxidation of Cys, Met, and Trp residues is associated with a decrease in the one-electron reduction of ferric HMb by other proteins; such heme-Fe(3+) reduction is critical to the maintenance of function as an oxygen storage protein in tissues.","pmid":"19800968","doi":"10.1016/j.freeradbiomed.2009.09.023","url":"https://pubmed.ncbi.nlm.nih.gov/19800968/"},{"id":2077,"title":"Analysis of myeloperoxidase promotor polymorphism and enzyme activity in Turkish patients with vitiligo.","authors":"Aksoy, S Nur; Erbagci, Zulal; Saygili, E Ilker; Sever, Tugce; Erbagci, A Binnur; Pehlivan, Sacide","year":2009,"date":"2009 Nov-Dec","journal":"European journal of dermatology : EJD","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Vitiligo is an acquired depigmentary disorder characterized by white areas of the skin due to loss of epidermal melanocytes. Oxidative stress and free radicals are suggested as important phenomena in the pathogenesis of vitiligo. Myeloperoxidase is a lysosomal enzyme of polymorphonuclear leukocytes and acts as a catalyst in the production of hypochlorous acid, a powerful oxidant. In this study we analysed enzyme activity and gene polymorphism of myeloperoxidase in patients with vitiligo. Fifty-four patients with vitiligo and 58 healthy controls were enrolled to this study. Patient groups were subdivided according to localization of the lesions; generalized, acrofacial and local. Plasma myeloperoxidase enzyme activity was determined with ELISA and G-463A gene (-463) polymorphism with the PCR-RFLP (AciI) method. The plasma MPO level was significantly lower in vitiligo patients than in the healthy controls (p = 0.005), however, it was not significantly different among subtypes of vitiligo (p = 0.8). A significant difference was not observed for G-463A genotype and allele distribution in patients with vitiligo. In conclusion, the present study is the first study investigating MPO G-463A polymorphism and enzyme levels, which warrants further studies with higher patient numbers and broader polymorphism panels.","pmid":"19758957","doi":"10.1684/ejd.2009.0793","url":"https://pubmed.ncbi.nlm.nih.gov/19758957/"},{"id":2081,"title":"Semicarbazide is non-specific as a marker metabolite to reveal nitrofurazone abuse as it can form under Hofmann conditions.","authors":"Bendall, Justin G","year":2009,"date":"2009 Jan","journal":"Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Detecting illegal nitrofurazone treatment of food-producing animals has been undermined by the reliance on semicarbazide as a marker metabolite for analysis because, during processing, semicarbazide forms in a variety of foods not exposed to nitrofurazone by previously unexplained pathways. In this study, formation of semicarbazide was examined under dairy product processing conditions. Hypochlorite dosed into milk on an industrial scale, at concentrations extreme for unintentional residues, produced monochloramine, but, without pH adjustment, hypochlorite alone did not generate semicarbazide. Dosed hypochlorite and peroxyacetic acid each generated low ng g(-1) levels of semicarbazide in milk (and whey) only when used in conjunction with localised high pH conditions, which can occur during both anion exchange and neutralisation. Dosed hydroxyurea generated semicarbazide at any pH, with greatest levels formed at high pH. Detecting nitrofurazone abuse can be better accomplished by analysis either for nitrofurazone itself or for the marker metabolite 5-nitro-2-furaldehyde, rather than semicarbazide.","pmid":"19680870","doi":"10.1080/02652030802190276","url":"https://pubmed.ncbi.nlm.nih.gov/19680870/"},{"id":2082,"title":"Chlorhexidine prevents hypochlorous acid-induced inactivation of alpha1-antitrypsin.","authors":"Montecucco, Fabrizio; Bertolotto, M; Ottonello, L; Pende, A; Dapino, P; Quercioli, A; Mach, F; Dallegri, F","year":2009,"date":"2009 Nov","journal":"Clinical and experimental pharmacology & physiology","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"1. Chlorhexidine digluconate has been used as a topical antiseptic in the treatment of acne vulgaris and periodontitis. The acute phase of these diseases involves neutrophilic infiltration. Neutrophil activation and recruitment to inflammatory sites are crucial in both protection against bacterial infection and the induction of hystotoxic damage. Activated neutrophils release several enzymes, including elastase and myeloperoxidase (MPO), which contribute to tissue injury via direct toxic actions, the generation of oxidants and inactivation of protective factors, such as alpha1-antitrypsin (alpha1-AT). In the present study, we investigated whether chlorhexidine can modulate neutrophil-mediated histotoxicity. 2. Human primary neutrophils were isolated from healthy donors. Inactivation of alpha1-AT by neutrophils or hypochlorous acid (HOCl) was evaluated by spectrophotometry and sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis of its capacity to complex with porcine pancreatic elastase (PPE). Neutrophil generation of HOCl, superoxide anion and MPO release were assessed spectrophometrically. 3. Chlorhexidine (0, 0.5, 1, 5 and 10 micromol/L) dose-dependently prevented HOCl-induced inactivation of alpha1-AT and reduced HOCl recovery from phorbol myristate acetate (PMA)-treated human neutrophils, but did not inhibit superoxide anion and MPO release. Chlorhexidine directly inhibited HOCl recovery from neutrophils and HOCl-induced inactivation of alpha1-AT in a cell-free assay. Accordingly, chlorhexidine reversed HOCl-mediated inhibition of alpha1-AT capacity to complex with PPE. 4. These data suggest that chlorhexidine prevents neutrophil-induced alpha1-AT inactivation via a direct inhibitory action on HOCl. Although highly speculative, the present study indicates that chlorhexidine may protect inflamed tissues not only through its antimicrobial properties, but also via a direct anti-inflammatory effect on neutrophil toxic products.","pmid":"19671069","doi":"10.1111/j.1440-1681.2009.05270.x","url":"https://pubmed.ncbi.nlm.nih.gov/19671069/"},{"id":2087,"title":"Impact of hypochlorite-based disinfection on bacterial contamination of cystic fibrosis patients' home-nebulisers.","authors":"Reychler, G; Leonard, A; Van Ossel, C; Godding, V; Gigi, J; Simon, A; Lebecque, P","year":2009,"date":"2009 Aug","journal":"The Journal of hospital infection","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Nebulisers are a potential source of bacterial contamination in cystic fibrosis (CF) patients. The aims of the study were to survey patient practice regarding maintenance of home nebulisers and to assess the impact of standardised guidelines derived from a previous in-vitro study. In total, 42 CF patients were studied. During two consecutive home visits, a questionnaire regarding routine patient practice was completed by a nurse while sputum and equipment samples were taken for bacteriological analyses. The first visit took place at baseline, and the second followed the implementation of detailed instructions for cleaning and disinfecting the nebulisers using a 0.5% hypochlorite solution. The first visit identified a great diversity in routine patient practices. Commensal bacteria, environmental bacteria and potential CF pathogens contaminated 78.5%, 57.1% and 14.3% of nebulisers respectively. After hypochlorite disinfection, rate and degree of global contamination decreased significantly, but the number of CF pathogens was not affected. There was no concordance between CF pathogens isolated from patients' sputum and their equipment. We conclude that in this sample of patients, initial routine practices were varied. With regard to CF pathogens, the superiority of a hypochlorite solution over a mix of other disinfection methods was not demonstrated.","pmid":"19596489","doi":"10.1016/j.jhin.2009.05.011","url":"https://pubmed.ncbi.nlm.nih.gov/19596489/"},{"id":2091,"title":"A centralised, automated dental hospital water quality and biofilm management system using neutral Ecasol maintains dental unit waterline output at better than potable quality: a 2-year longitudinal study.","authors":"O'Donnell, M J; Boyle, M; Swan, J; Russell, R J; Coleman, D C","year":2009,"date":"2009 Oct","journal":"Journal of dentistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Most studies addressing biofilm formation in dental chair unit waterlines (DUWLs) have focused on a range of individual dental chair units (DCUs) and no studies on a centralised approach in a large number of DCUs have been reported to date. OBJECTIVES: To develop a centralised, automated water quality and biofilm management system serving the distribution network providing water to Dublin Dental Hospital's 103 DCUs, capable of maintaining DUWL supply and output water at better than potable quality standards in the long-term and requiring a minimum of human intervention. The potable water standard for the European Union does not specify an upper limit of aerobic heterotrophic bacteria, whereas a maximum of 100 cfu/mL is permitted in bottled water. METHODS: Mains water of varying quality was treated by specifically selected automated filtration units to provide DCUs with water of consistent chemical composition. This water was then automatically disinfected using an electrochemically activated solution Ecasol (Trustwater Group, Clonmel, Ireland) (2.5 ppm) prior to distribution to DCUs. Microbiological quality of both DUWL supply and output water was monitored weekly by culture on R2A agar for 10 sentinel DCUs for a 100-week period. DUWLs were tested for the presence of biofilm by electron microscopy. RESULTS: Chemical composition of processed mains water consistently bettered potable water standards. DUWL supply water and output water aerobic heterotrophic bacterial counts averaged <1 and 18.1 cfu/mL, respectively, from the 10 DCUs, compared to 88 cfu/mL for unprocessed mains water. This correlated with the absence of biofilm in DUWLs. No adverse effects due to Ecasol treatment of supply water were observed for DUWLs or DCU instruments. CONCLUSIONS: This centralised and automated water treatment and biofilm management system consistently maintains DUWL output water at better than potable quality simultaneously in a large number of DCUs over the long-term.","pmid":"19573971","doi":"10.1016/j.jdent.2009.06.001","url":"https://pubmed.ncbi.nlm.nih.gov/19573971/"},{"id":2092,"title":"Pathways for the decay of organic dichloramines and liberation of antimicrobial chloramine gases.","authors":"Coker, Melanie S A; Hu, Wan-Ping; Senthilmohan, Senti T; Kettle, Anthony J","year":2008,"date":"2008 Dec","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"When neutrophils phagocytose bacteria, they generate the cytotoxic agent hypochlorous acid (HOCl). The specific role that HOCl plays in bacterial killing is unclear. In the phagosome, it should react with neutrophil proteins to form protein chloramines and dichloramines. We investigated the stability of model dichloramines that are likely to be formed on N-terminal amino acids and Lys residues of proteins contained within phagosomes. Dichloramines were much more unstable than their analogous monochloramines. The stability was affected by substituents on the alpha-carbon. Amino acid dichloramines were extremely unstable, indicating that an alpha-carboxyl group facilitated decomposition. In general, the absence of a substituent enhanced stability. The carboxyl group on N-terminal Glu residues favored break down, but this effect was not apparent with Asp residues. Unstable dichloramines that contained a substituent on their alpha-carbon were cytotoxic and killed 50% of 10(5) Staphylococcus aureus (LD50) at a dose of approximately 2.5 nmol. Their cytotoxicity declined with time. The dichloramines of N-alpha-acetyl Lys and taurine were not bactericidal up to 10 nmol per 10(5) S. aureus. None of the analogous monochloramines were cytotoxic at this dose. Dichloramines decomposed to yield chlorimines, aldehydes, and the inorganic gases ammonia monochloramine (NH2Cl) and ammonia dichloramine (NHCl2). The LD50 values were determined for NH2Cl (0.37 +/- 0.14 nmol), NHCl2 (0.08 +/- 0.02 nmol), and HOCl (0.14 +/- 0.04 nmol). Stable products formed during the breakdown of dichloramines were not bactericidal. We propose a potential antimicrobial mechanism that explains in part how HOCl can react mainly with neutrophil components but still promote killing of phagocytosed bacteria. HOCl produced in phagosomes will react with amine groups on neutrophil proteins to form unstable dichloramines that will liberate cytotoxic NH2Cl and NHCl2. These gases will contribute to killing of ingested bacteria.","pmid":"19548354","doi":"10.1021/tx800232v","url":"https://pubmed.ncbi.nlm.nih.gov/19548354/"},{"id":2093,"title":"Effect of electrolyzed strong acid water on peritoneal irrigation of experimental perforated peritonitis.","authors":"Kubota, Akio; Nose, Keisuke; Yonekura, Takeo; Kosumi, Takuya; Yamauchi, Katsuji; Oyanagi, Harumasa","year":2009,"date":"2009","journal":"Surgery today","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"PURPOSE: Electrolyzed strong acid water (ESAW) is generated by the electrolysis of a weak sodium chloride solution. Although ESAW is known to have a strong bactericidal activity and to be harmless to the living body, its effectiveness and safety in the treatment of perforated peritonitis has not been well established. METHODS: Male Wistar rats were used for the study. Three hours after cecal ligation and puncture, the cecum was resected and the peritoneal cavity was irrigated with 50 ml of saline (Group S, n=12) or ESAW (Group E, n=14). The 5-day survival rate was compared between the two groups. In another pair of animals (n=10 each), bacteria in the ascitic fluid were counted at 6 and 18 h after irrigation. RESULTS: No adverse effects of ESAW were observed in the experimental group. The 5-day survival rate was 25% (3/12) and 85.7% (12/14) in Groups S and E, respectively (P < 0.01). The bacterial count at 18 h after the irrigation in Groups S and E was (5.0 +/- 2.5) x 10(5)/ml and (2.2 +/- 2.0) x 10(4)/ml, respectively (P < 0.0001). CONCLUSION: Peritoneal lavage with ESAW had no adverse effect, and achieved more effective decontamination than saline for perforated peritonitis. Therefore, the results of this study are considered to warrant and support the clinical application of ESAW.","pmid":"19468808","doi":"10.1007/s00595-008-3914-4","url":"https://pubmed.ncbi.nlm.nih.gov/19468808/"},{"id":2094,"title":"Feasibility of infectious prion digestion using mild conditions and commercial subtilisin.","authors":"Pilon, John L; Nash, Paul B; Arver, Terry; Hoglund, Don; Vercauteren, Kurt C","year":2009,"date":"2009 Oct","journal":"Journal of virological methods","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Two serine protease enzymes, subtilisin 309 and subtilisin 309-v, were used to digest brain homogenates containing high levels of prion infectivity using mildly alkaline conditions to investigate prion decontamination methods. To establish that PrP(res) infectivity was eliminated, we utilized the Rocky Mountain Laboratory (RML) mouse-adapted scrapie model system for bioassay. Only one digestion condition (subtilisin 309 at 138mAU/ml, 55 degrees C and 14h digestion time pH 7.9) was considered to be highly relevant statistically (P<0.001) compared to control, with 52% of challenged mice surviving until the end of the study period. In contrast, treatment of PrP(res) by autoclaving at 134 degrees C or treatment with hypochlorite at a concentration of 20,000 ppm completely protected mice from prionosis. Further, in vitro assays suggest that potential proteolytic based PrP(res) decontamination methods must use high enzyme concentration, pH values >9.0, and elevated temperatures to be a safely efficacious, thereby limiting applicability on delicate surgical instruments and use in the environment.","pmid":"19467265","doi":"10.1016/j.jviromet.2009.04.040","url":"https://pubmed.ncbi.nlm.nih.gov/19467265/"},{"id":2097,"title":"Possible role of reactive chlorine in microbial antagonism and organic matter chlorination in terrestrial environments.","authors":"Bengtson, Per; Bastviken, David; de Boer, Wietse; Oberg, Gunilla","year":2009,"date":"2009 Jun","journal":"Environmental microbiology","category":"Food & agriculture","evidence":"Review","relevance":"High","abstract":"Several studies have demonstrated that extensive formation of organically bound chlorine occurs both in soil and in decaying plant material. Previous studies suggest that enzymatic formation of reactive chlorine outside cells is a major source. However, the ecological role of microbial-induced extracellular chlorination processes remains unclear. In the present paper, we assess whether or not the literature supports the hypothesis that extracellular chlorination is involved in direct antagonism against competitors for the same resources. Our review shows that it is by no means rare that biotic processes create conditions that render biocidal concentrations of reactive chlorine compounds, which suggest that extracellular production of reactive chlorine may have an important role in antagonistic microbial interactions. To test the validity, we searched the UniprotPK database for microorganisms that are known to produce haloperoxidases. It appeared that many of the identified haloperoxidases from terrestrial environments are originating from organisms that are associated with living plants or decomposing plant material. The results of the in silico screening were supported by various field and laboratory studies on natural chlorination. Hence, the ability to produce reactive chlorine seems to be especially common in environments that are known for antibiotic-mediated competition for resources (interference competition). Yet, the ability to produce haloperoxidases is also recorded, for example, for plant endosymbionts and parasites, and there is little or no empirical evidence that suggests that these organisms are antagonistic.","pmid":"19453612","doi":"10.1111/j.1462-2920.2009.01915.x","url":"https://pubmed.ncbi.nlm.nih.gov/19453612/"},{"id":2099,"title":"Methylamine dichloramine may play a role in the process of colorectal disease through architectural and oxidative changes in crypts in mice.","authors":"Tachikawa, Mariko; Amano, Kayoko; Nishiyama, Kotaro; Urano, Atsushi; Kato, Koichi; Yamanaka, Kenzo","year":2009,"date":"2009 Jun 19","journal":"Life sciences","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"AIMS: Methylamine dichloramine (CH(3)NCl(2)) produced by neutrophils may promote colon tumors and colitis via architectural and oxidative changes in crypts, which are secretory granulae composed of goblet cells located in the colorectal mucosal layer. We investigated whether CH(3)NCl(2), in comparison with the other reactive oxygen species (ROS) such as H(2)O(2) and HOCl, derived from primed neutrophils in inflammatory sites in the large intestine, is a biogenic factor for the induction of colorectal disease in mice. MAIN METHODS: Male ICR-strain mice were administered each oxidant (0.5-0.7 micromol/mouse) by enema under anesthesia. The colorectal tissues were evaluated by histopathological and immunohistochemical analyses. Hemolysis and hemoglobin oxidation by the methylamine chloramines and HOCl were examined by adding them (50-400 microM) to a sheep erythrocyte suspension (1x10(8) cells/ml) and its lysate at pH 7 and 37 degrees C. KEY FINDINGS: CH(3)NCl(2) oxidized erythrocyte hemoglobin more effectively than HOCl, indicating it has high cell permeability and selective oxidation ability. CH(3)NCl(2) mainly induced atrophy of crypts at 6 h after administration, while the other ROS tested did not. Furthermore, 4-hydroxy-2-nonenal (4-HNE) showed positive immunostains throughout the mucosal layer, including around the basal regions of atrophied crypts, only with CH(3)NCl(2), while positive immunostains were observed for 3-nitrotyrosine (3-NT) in the atrophied crypts and their surrounding lamina propria in the mucosal layer. SIGNIFICANCE: The results suggest that CH(3)NCl(2)derived from primed neutrophils may play the most important role in promoting the development of colon tumor formation and colitis by oxidative stress through its high degree of cell permeability.","pmid":"19389412","doi":"10.1016/j.lfs.2009.04.007","url":"https://pubmed.ncbi.nlm.nih.gov/19389412/"},{"id":2103,"title":"Upflow anaerobic filter for the degradation of adsorbable organic halides (AOX) from bleach composite wastewater of pulp and paper industry.","authors":"Deshmukh, N S; Lapsiya, K L; Savant, D V; Chiplonkar, S A; Yeole, T Y; Dhakephalkar, P K; Ranade, D R","year":2009,"date":"2009 May","journal":"Chemosphere","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The removal of AOX from bleach plant effluent of pulp and paper industry was studied using upflow anaerobic filter. In this paper biodegradation of AOX at different concentrations and effect of electron donors like acetate and glucose thereon in an upflow anaerobic filter at 20 d HRT is described. Results showed significant improvement in AOX degradation when electron donors such as acetate and glucose were supplemented to the influent. AOX degradation was 88% at 28 mg AOX L(-1) and 28% at 42 mg AOX L(-1). The percent degradation efficiency was enhanced to 90.7, 90.2, and 93.0 at 28 mg AOX L(-1) when the influent was supplemented with glucose, acetate and both glucose and acetate, respectively. Similarly, the efficiency was 57, 56.6 and 79.6 at 42 mg AOX L(-1) when the influent was supplemented with glucose, acetate and both glucose and acetate, respectively. The GC-MS analysis data indicated that supplementation of the influent with electron donor increased the biodegradability of number of chlorinated organic compounds.","pmid":"19327815","doi":"10.1016/j.chemosphere.2009.02.042","url":"https://pubmed.ncbi.nlm.nih.gov/19327815/"},{"id":2104,"title":"What are the plasma targets of the oxidant hypochlorous acid? A kinetic modeling approach.","authors":"Pattison, David I; Hawkins, Clare L; Davies, Michael J","year":2009,"date":"2009 May","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase (MPO) is a heme enzyme, released by activated leukocytes at sites of inflammation, which catalyzes the formation of the potent oxidant, hypochlorous acid (HOCl), from H2O2. HOCl is a key component of the inflammatory response and is bactericidal but has been linked with several human pathologies as a result of damage to host tissue. Elevated plasma MPO levels are a strong independent risk factor, and predictor of outcomes, for cardiovascular disease. Rate constants for reaction of HOCl with individual biological targets and the products of these reactions have been determined, but the targets of HOCl in complex biological fluids such as plasma are incompletely defined. In this study, rate constants (M(-1) s(-1)) for the reactions of ascorbate with HOCl (ca. 6 x 10(6)) and imidazole chloramine (7.7 x 10(4)) have been determined to supplement known kinetic parameters. HOCl-mediated oxidation of the major plasma protein, albumin, was investigated both experimentally and computationally; these approaches provide consistent data. The computational studies were extended to examine the fate of HOCl in plasma. The model predicts that plasma proteins consume the majority of HOCl with limited damage to other materials. Ascorbate or alpha-tocopherol, even at the levels achieved in human supplementation studies, do not attenuate these reactions. In contrast, elevated levels of thiocyanate ions (SCN(-)), as detected in heavy smokers, can modulate HOCl-mediated reactions as a result of the formation of the highly specific oxidant hypothiocyanous acid (HOSCN). These observations support the hypothesis that MPO-generated HOSCN is a key agent in smoking-enhanced atherosclerosis.","pmid":"19326902","doi":"10.1021/tx800372d","url":"https://pubmed.ncbi.nlm.nih.gov/19326902/"},{"id":2109,"title":"Chlorogenic acid protects paraoxonase 1 activity in high density lipoprotein from inactivation caused by physiological concentrations of hypochlorite.","authors":"Gugliucci, Alejandro; Bastos, Deborah H Markowicz","year":2009,"date":"2009 Mar","journal":"Fitoterapia","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"We hypothesized that chlorogenic acids, the main phenolics in coffee, many fruits and Ilex paraguariensis extracts, protect paraoxonase 1 activity in HDL from inactivation by chlorination at concentrations of HOCl (50 microM) and chlorogenic acid (2-10 microM) compatible with those found in humans. When human HDL was incubated in the presence of HOCl/OCl-, a concentration dependent loss of activity was apparent. Of interest, 5 caffeoylquinic acid at 5 micromol/L affords more than 60% protection of the activity reaching 100% at 25 micromol/L. This compound and the plant sources that are rich in them may be protectors of paraoxonase 1 activity.","pmid":"19248222","doi":"10.1016/j.fitote.2009.01.001","url":"https://pubmed.ncbi.nlm.nih.gov/19248222/"},{"id":2110,"title":"Hypochlorite treatments are not a significant source of perchlorate exposure in lettuce.","authors":"Sanchez, C A; Fonseca, J M; Blount, B C; Krieger, R I","year":2009,"date":"2009 Mar 25","journal":"Journal of agricultural and food chemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Leafy vegetables, such as lettuce ( Lactuca sativa L), have been identified as a potential source of perchlorate exposure to humans. Perchlorate is of concern because excessive amounts may impair thyroid function by inhibiting iodide uptake by the sodium iodide symporter. Perchlorate has been identified as an oxidation product in sodium hypochlorite. Dilute hypochlorite solutions are widely used on lettuce as a preservative and as a treatment to reduce microbial food risks. However, the potential of hypochlorite to be a source of human perchlorate exposure from lettuce had not been evaluated. Studies were conducted with lettuce collected in the San Luis Valley of southern Colorado and in the lower Colorado River Valley of southwestern Arizona to represent conditions under which hypochlorite is applied to lettuce in the field and in salad processing facilities. We used spray and dipping solutions that were dilutions of concentrated sodium hypochlorite that would contain from 12000 and 120000 microg/L perchlorate. The perchlorate content of iceberg and romaine lettuce averaged 6.2 and 7.2 microg/kg fw in southern Colorado and 14.0 and 56.7 microg/kg fw in southwestern Arizona and there were no significant (P > 0.05) increases in the perchlorate content of lettuce due to hypochlorite treatments. Because of the relatively low concentrations of perchlorate present after dilution and the low volumes applied to lettuce, hypochlorite solutions do not appear to be a significant source of the perchlorate levels found in lettuce.","pmid":"19245207","doi":"10.1021/jf8033013","url":"https://pubmed.ncbi.nlm.nih.gov/19245207/"},{"id":2115,"title":"Spatio-temporal analysis of infra-specific genetic variations among a Pseudomonas aeruginosa water network hospital population: invasion and selection of clonal complexes.","authors":"Lavenir, R; Sanroma, M; Gibert, S; Crouzet, O; Laurent, F; Kravtsoff, J; Mazoyer, M-A; Cournoyer, B","year":2008,"date":"2008 Nov","journal":"Journal of applied microbiology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"AIMS: To investigate infra-specific spatio-temporal dynamics of a hospital water network Pseudomonas aeruginosa population. To infer the origin of water network isolates and assess their potential health hazard. METHODS AND RESULTS: 168 P. aeruginosa strains were isolated from tap waters and swabs of tap nozzle aerators of a hospital unit, over 2 years, and from rectal swabs and nosocomial infections. Genetic diversity among this collection was assessed by pulsed field gel electrophoresis of SpeI restricted genomic DNA. Virulence gene sets, biofilm properties, and hypochlorite resistance were analysed. Exactly 68% of the water samples and 74% of the tap nozzle aerators harboured P. aeruginosa. The strains were divided into 22 clonal lineages, with one dominant clone shown to have been involved in a nosocomial infection. CONCLUSIONS: An important turnover among the P. aeruginosa hospital population was observed. Some clonal lineages were found to persist, spread in the unit, and diversify into clonal complexes. Rectal carriage appeared an important source of contamination of the water network. SIGNIFICANCE AND IMPACT OF THE STUDY: High P. aeruginosa infra-specific population diversity suggested a broad ability in colonizing water networks but persistence analysis indicated a strong selection leading to the emergence of dominant clones.","pmid":"19146487","doi":"10.1111/j.1365-2672.2008.03907.x","url":"https://pubmed.ncbi.nlm.nih.gov/19146487/"},{"id":2116,"title":"Phagocytosis, oxidative burst, and produced reactive species are affected by iron deficiency anemia and anemia of chronic diseases in elderly.","authors":"Paino, I M M; Miranda, J C; Marzocchi-Machado, C M; Cesarino, E J; de Castro, F A; de Souza, A M","year":2009,"date":"2009 Summer","journal":"Biological trace element research","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Iron and oxidative stress have a regulatory interplay. During the oxidative burst, phagocytic cells produce free radicals such as hypochlorous acid (HOCl). Nevertheless, scarce studies evaluated the effect of either iron deficiency anemia (IDA) or anemia of chronic disease (ACD) on phagocyte function in the elderly. The aim of the present study was to determine the oxidative burst, phagocytosis, and nitric oxide (*NO) and HOCl, reactive species produced by monocytes and neutrophils in elderly with ACD or IDA. Soluble transferrin receptor, serum ferritin, and soluble transferrin receptor/log ferritin (TfR-F) index determined the iron status. The study was constituted of 39 patients aged over 60 (28 women and 11 men) recruited from the Brazilian Public Health System. Oxidative burst fluorescence intensity per neutrophil in IDA group and HOCl generation in both ACD and IDA groups were found to be lower (p < 0.05). The percentages of neutrophils and monocytes expressing phagocytosis in ACD group were found to be higher (p < 0.05). There was an overproduction of *NO from monocytes, whereas the fundamental generation of HOCl appeared to be lower. Phagocytosis, oxidative burst, and *NO and HOCl production are involved in iron metabolism regulation in elderly patients with ACD and IDA.","pmid":"19129984","doi":"10.1007/s12011-008-8303-8","url":"https://pubmed.ncbi.nlm.nih.gov/19129984/"},{"id":2122,"title":"Chemical fate and changes in mutagenic activity of antibiotics nitrofurazone and furazolidone during aqueous chlorination.","authors":"Nakamura, Hitomi; Kawakami, Tsuyoshi; Niino, Tatsuhiro; Takahashi, Yasuo; Onodera, Sukeo","year":2008,"date":"2008 Dec","journal":"The Journal of toxicological sciences","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Reactions of nitrofuran antibiotics (nitrofurazone (NFZ) and frazolidone (FZD)) with hypochlorite in aqueous solution were investigated under the conditions that simulate wastewater disinfection. The chlorination byproducts were determined by high performance liquid chromatography. At the levels of 5 microM, NFZ reacted rapidly with free chlorine in neutral pH (7.0), while the FZD-hypochlorite reaction was reasonably slow under the same pH. Nevertheless, the strong mutagenic parents disappeared completely after the hypochlorite reactions, and the chlorination byproducts were observed to exert a weak mutagenic effect on Salmonella typhimurium TA100 without S9-mix. The extent of the reactions depended on the chlorine dose, solution pH and compound structures.","pmid":"19043283","doi":"10.2131/jts.33.621","url":"https://pubmed.ncbi.nlm.nih.gov/19043283/"},{"id":2126,"title":"Bleach activates a redox-regulated chaperone by oxidative protein unfolding.","authors":"Winter, J; Ilbert, M; Graf, P C F; Ozcelik, D; Jakob, U","year":2008,"date":"2008 Nov 14","journal":"Cell","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Hypochlorous acid (HOCl), the active ingredient in household bleach, is an effective antimicrobial produced by the mammalian host defense to kill invading microorganisms. Despite the widespread use of HOCl, surprisingly little is known about its mode of action. In this study, we demonstrate that low molar ratios of HOCl to protein cause oxidative protein unfolding in vitro and target thermolabile proteins for irreversible aggregation in vivo. As a defense mechanism, bacteria use the redox-regulated chaperone Hsp33, which responds to bleach treatment with the reversible oxidative unfolding of its C-terminal redox switch domain. HOCl-mediated unfolding turns inactive Hsp33 into a highly active chaperone holdase, which protects essential Escherichia coli proteins against HOCl-induced aggregation and increases bacterial HOCl resistance. Our results substantially improve our molecular understanding about HOCl's functional mechanism. They suggest that the antimicrobial effects of bleach are largely based on HOCl's ability to cause aggregation of essential bacterial proteins.","pmid":"19013278","doi":"10.1016/j.cell.2008.09.024","url":"https://pubmed.ncbi.nlm.nih.gov/19013278/"},{"id":2127,"title":"Unusual products of the aqueous chlorination of atenolol.","authors":"DellaGreca, Marina; Iesce, Maria Rosaria; Pistillo, Paola; Previtera, Lucio; Temussi, Fabio","year":2009,"date":"2009 Feb","journal":"Chemosphere","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The reaction of the drug atenolol with hypochlorite under conditions that simulate wastewater disinfection was investigated. The pharmaceutical reacted in 1h yielding three products that were separated by chromatographic techniques and characterized by spectroscopic features. Two unusual products 2-(4-(3-(chloro(2-chloropropan-2-yl)amino)-2-hydroxypropoxy)phenyl) acetamide and 2-(4-(3-formamido-2-hydroxypropoxy)phenyl) acetamide were obtained along with 2-(4-hydroxyphenyl) acetamide. When the reaction was stopped at shorter times only 2-(4-(3-amino-2-hydroxypropoxy)phenyl) acetamide and the dichlorinated product were detected. Tests performed on the seeds of Lactuca sativa show that chlorinated products have phytotoxic activity.","pmid":"18996563","doi":"10.1016/j.chemosphere.2008.09.067","url":"https://pubmed.ncbi.nlm.nih.gov/18996563/"},{"id":2129,"title":"Neutral super-oxidised solutions are effective in killing P. aeruginosa biofilms.","authors":"Sauer, Karin; Thatcher, Eileen; Northey, Robert; Gutierrez, Andres A","year":2009,"date":"2009","journal":"Biofouling","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Bacteria growing in biofilms can become up to 1000-fold more resistant to antibiotics and biocides as compared to their planktonic counterparts. As a result of this increased resistance, biofilms and biofilm-related infections cannot be effectively treated with conventional antibiotic therapy. The goal of this study was to determine the efficacy of three neutral pH, super-oxidised solutions (nSOSs, OIS-80, OIS-125, OIS-200, Microcyn Technology) varying in oxychlorine concentration (80, 125 and 200 ppm) against P. aeruginosa grown planktonically and as biofilms. Exposure for 20 s of exponential phase cells to any of the three solutions was sufficient to reduce viability by more than five logs. However, only exposure for 10 min to OIS-125 and OIS-200 for 10 min was sufficient to eradicate stationary phase P. aeruginosa cells. The efficacy of nSOSs on P. aeruginosa biofilms, grown to maturity in continuous flow tube reactors, was determined upon treatment up to 60 min. Viability pre- and post-treatment was determined by CFU counts. The effect of these solutions on P. aeruginosa biofilms and biofilm architecture was further visualised by confocal scanning laser microscopy and quantitatively analysed by COMSTAT. Under these experimental conditions, only OIS-125 and OIS-200 achieved a >3-log reduction and biofilm disaggregation within 30 min of exposure. Because OIS-125 and OIS-200 enhance the disaggregation of biofilms, their use in the treatment of surface-related biofilm infections deserves further investigation.","pmid":"18846439","doi":"10.1080/08927010802441412","url":"https://pubmed.ncbi.nlm.nih.gov/18846439/"},{"id":2132,"title":"Hypochlorite-induced oxidation of dairy proteins: impact of pH and oxidant concentration.","authors":"Kerkaert, B; Mestdagh, F; Cucu, T; De Meulenaer, B","year":2008,"date":"2008","journal":"Communications in agricultural and applied biological sciences","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"","pmid":"18831266","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/18831266/"},{"id":2133,"title":"Examination of hypochlorous acid-induced damage to cytosine residues in a CpG dinucleotide in DNA.","authors":"Kang, Joseph I Jr; Sowers, Lawrence C","year":2008,"date":"2008 Jun","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Inflammation-mediated, neutrophil-derived hypochlorous acid can damage DNA and result in the chlorination damage products 5-chlorocytosine and 5-chlorouracil as well as the oxidation damage products 5-hydroxycytosine and 5-hydroxyuracil. While 5-chlorocytosine could potentially perturb epigenetic signals if formed at a CpG dinucleotide, the remaining products are miscoding and could result in transition mutations. In this article, we have investigated the reaction of hypochlorous acid with an oligonucleotide site-specifically enriched with 15N to probe the reactivity of cytosine at CpG. These experiments demonstrate directly the formation of 5-chlorocytosine at a CpG dinucleotide in duplex DNA. We observe that chlorination relative to oxidation damage is greater at CpG by a factor of approximately two, whereas similar amounts of 5-chlorocytosine and 5-hydroxycytosine are formed at two non-CpG sites examined. The relative amounts of deamination of the cytosine to uracil derivatives are similar at CpG and non-CpG sites. Overall, we observe that the reactivity of cytosine at CpG and non-CpG sites toward hypochlorous acid induced damage is similar (5-chlorocytosine > 5-hydroxycytosine > 5-hydroxyuracil > 5-chlorouracil), with a greater proportion of chlorination damage at CpG sites. These results are in accord with the potential of inflammation-mediated DNA damage to both induce transition mutations and to perturb epigenetic signals.","pmid":"18826175","doi":"10.1021/tx800037h","url":"https://pubmed.ncbi.nlm.nih.gov/18826175/"},{"id":2138,"title":"Identification of plasma proteins that are susceptible to thiol oxidation by hypochlorous acid and N-chloramines.","authors":"Summers, Fiona A; Morgan, Philip E; Davies, Michael J; Hawkins, Clare L","year":2008,"date":"2008 Sep","journal":"Chemical research in toxicology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Hypochlorous acid (HOCl), the major strong oxidant produced by myeloperoxidase, reacts readily with free amino groups to form N-chloramines. Although HOCl and N-chloramines play an important role in the human immune system by killing bacteria and invading pathogens, they have also been shown to cause damage to tissues, which is believed to contribute to a number of diseases. It has been shown previously that N-chloramines react more readily with protein thiols than with other targets in plasma, but the nature of the plasma thiol-containing proteins oxidized is unknown. In this study, the ability of N-chloramines to selectively oxidize thiol-containing plasma proteins was determined using the thiol-specific probe, 5-iodoacetamidofluorescein, combined with two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Experiments were performed with N-chloramines formed on Nalpha-acetyl-lysine, Nalpha-acetyl-histidine (HisCA), glycine, taurine, and ammonia. With the exception of HisCA, the N-chloramines were more efficient than HOCl at oxidizing plasma thiols. The thiol-containing plasma proteins alpha1-antitrypsin and transthyretin were found to be oxidized in addition to albumin, with this treatment resulting in the inactivation of alpha1-antitrypsin. A similar selectivity of reaction and extent of thiol oxidation were also observed with myeloperoxidase in the presence of hydrogen peroxide and chloride ions.","pmid":"18698849","doi":"10.1021/tx8001719","url":"https://pubmed.ncbi.nlm.nih.gov/18698849/"},{"id":2140,"title":"Effects of a low concentration hypochlorous Acid nasal irrigation solution on bacteria, fungi, and virus.","authors":"Kim, Hyun Jik; Lee, Jeung-Gweon; Kang, Ju Wan; Cho, Hyung-Ju; Kim, Hyun Su; Byeon, Hyung Kwon; Yoon, Joo-Heon","year":2008,"date":"2008 Oct","journal":"The Laryngoscope","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVES/HYPOTHESIS: Saline irrigation would be more effective for chronic sinusitis patients if it had bactericidal effects. Low concentrations of hypochlorous acid may be used as a nasal irrigation solution. First, we developed a 0.85% NaCl solution by adding NaCl to tap water (pH 7.0 and 8.4) and measuring the concentration of free chlorine and hypochlorous acid after giving the solution a short electrical impulse of 20 seconds. Then we investigated whether the derived hypochlorous acid had a toxic effect on human primary nasal epithelial cells, if and what effect it had on the expression of mucin genes, and, finally, if it had bactericidal, fungicidal, or virucidal effects. STUDY DESIGN: In vitro biochemical experiment. METHODS: We treated human primary nasal epithelial cells with 3.5 ppm of hypochlorous acid and then examined the cells for cytotoxicity. We also investigated the bactericidal, fungicidal, and virucidal effects by challenging the cells with the following microorganisms Aspergillus fumigatus, Haemophilus influenzae, Klebsiella pneumoniae, Rhizopus oryzae, Candida albicans, Methicillin-resistant Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus pyogenes. To study the virucidal effects of HOCl, we used the human influenza A virus to challenge the cells. RESULTS: : In the cytotoxicity assay and in the morphological examination, the cells did not show anytoxicity at 30 minute or 2 hours after treatment with HOCl. More than 99% of bactericidal or fungicidal activity was noted for all species, except for Candida albicans, in tap water at either pH 7.0 or 8.4. In addition, a 3.2-log10 reduction was achieved in cells challenged with the human influenza A virus. CONCLUSIONS: A low concentration HOCl solution can be used as an effective nasal irrigation solution.","pmid":"18677274","doi":"10.1097/MLG.0b013e31817f4d34","url":"https://pubmed.ncbi.nlm.nih.gov/18677274/"},{"id":2144,"title":"Hypochlorous acid oxidizes methionine and tryptophan residues in myoglobin.","authors":"Szuchman-Sapir, Andrea J; Pattison, David I; Ellis, Natasha A; Hawkins, Clare L; Davies, Michael J; Witting, Paul K","year":2008,"date":"2008 Sep 15","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"After acute myocardial infarction (AMI), infiltrating proinflammatory cells generate two-electron oxidants such as hypochlorous acid (HOCl). Myoglobin (Mb) is present at approximately 0.3 mM in cardiomyocytes and, therefore, represents a significant target for oxidation. Exposure of horse Mb (50 microM) to reagent HOCl (0-500 microM) or activated human neutrophils (4-40x10(6) cells/ml) yielded oxidized Mb (Mb(ox)) as judged by amino acid analysis and peptide mass mapping. HOCl/Mb ratios of 1-5 mol/mol gave Mb(ox) with up to four additional oxygen atoms. Hydrolysis of Mb(ox) followed by amino acid analysis indicated that methionine (Met) and tryptophan (Trp) residues were modified by HOCl. Peptide mass mapping revealed that Met55 was oxidized at a lower HOCl/Mb ratio than Met131 and this preceded Trp7/14 modification (susceptibility Met55>Met131>Trp7>Trp14). Incubation of Mb with activated neutrophils and physiological chloride anion yielded Mb(ox) with a composition similar to that determined with HOCl/Mb ratios <2 mol/mol, with oxidation of Met, but not Trp, detected. These data indicate that Mb undergoes site-specific oxidation depending on the HOCl/protein ratio. As Mb is released from necrotic cardiomyocytes into the vasculature after AMI, HOCl-modified Mb may be a useful surrogate marker to gauge the extent of myocardial inflammation.","pmid":"18625300","doi":"10.1016/j.freeradbiomed.2008.06.010","url":"https://pubmed.ncbi.nlm.nih.gov/18625300/"},{"id":2151,"title":"Galloylated catechins as potent inhibitors of hypochlorous acid-induced DNA damage.","authors":"Kawai, Yoshichika; Matsui, Yuri; Kondo, Hajime; Morinaga, Hiroshi; Uchida, Koji; Miyoshi, Noriyuki; Nakamura, Yoshimasa; Osawa, Toshihiko","year":2008,"date":"2008 Jul","journal":"Chemical research in toxicology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCl), a strong oxidant derived from myeloperoxidase in neutrophils and macrophages, can chlorinate DNA bases at the site of inflammation. Because little is known about the protective role of natural antioxidants, such as polyphenols, for the myeloperoxidase-derived DNA damage, we screened the inhibitory effects of various phenolic antioxidants on the chlorination of the 2'-deoxycytidine residue by HOCl in vitro and found that green tea catechins, especially (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg), significantly inhibited the chlorination. These catechins also reduced nucleoside- and taurine-chloramines, which can induce secondary oxidative damage, into their native forms. Mass spectrometric and nuclear magnetic resonance analyses showed that ECg and EGCg can effectively scavenge HOCl and/or chloramine species resulting in the formation of mono- and dichlorinated ECg and EGCg. Using the HL-60 human leukemia cell line, it was found that ECg could efficiently accumulate in the cells. Immunocytometric analyses using antihalogenated 2'-deoxycytidine antibody showed that pretreatment of cells with ECg inhibited the HOCl-induced immunofluorescence. In addition, the chlorinated ECg derivatives were detected in the HOCl-treated HL-60 cells. These results showed that green tea catechins, especially 3-galloylated catechins, may be the plausible candidate for the prevention of inflammation-derived DNA damage and perhaps carcinogenesis.","pmid":"18512968","doi":"10.1021/tx800069e","url":"https://pubmed.ncbi.nlm.nih.gov/18512968/"},{"id":2153,"title":"Comparing the efficacy of chlorine, chlorine dioxide, and ozone in the inactivation of Cryptosporidium parvum in water from Parana State, Southern Brazil.","authors":"Pereira, Juliana Tracz; Costa, Adriana Oliveira; de Oliveira Silva, Márcia Benedita; Schuchard, Wagner; Osaki, Silvia Cristina; de Castro, Edilene Alcântara; Paulino, Rosangela Clara; Soccol, Vanete Thomaz","year":2008,"date":"2008 Dec","journal":"Applied biochemistry and biotechnology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"In the present work, assays were performed to compare the efficacy of hypochlorous acid, chlorine dioxide, and ozone in the inactivation of Cryptosporidium oocyst in public water supply from Brazilian South conditions. Experiments were carried out in samples containing 2 x 10(4) oocysts/ml of C. parvum purified from feces of experimentally contaminated calves. An in vitro excystation method was used to evaluate oocysts' viability and to determine the inactivation rates of hypochlorous acid at 2 ppm, chlorine dioxide at 1, 2, and 5 ppm, and ozone at the doses of 0.18, 0.24, 0.36, 0.48, and 1.44 mg/l. By using hypochlorous acid, the maximum inactivation rate obtained was 49.04% after 120 min. Chlorine dioxide at 5 ppm inactivated 90.56% of oocysts after 90 min of contact. Ozone was the most effective product, rendering an inactivation of 100% with the concentration of 24 mg/l. Resistance of Cryptosporidium to the usual disinfectants and the need for more effective water treatments to prevent waterborne diseases in Brazil are discussed in this manuscript.","pmid":"18498060","doi":"10.1007/s12010-008-8214-3","url":"https://pubmed.ncbi.nlm.nih.gov/18498060/"},{"id":2154,"title":"Inactivation of mitochondrial NADP+-dependent isocitrate dehydrogenase by hypochlorous acid.","authors":"Park, Sin Young; Lee, Su-Min; Shin, Seoung Woo; Park, Jeen-Woo","year":2008,"date":"2008 May","journal":"Free radical research","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeoloperoxidase catalyses the formation of hypochlorous acid (HOCl) via reaction of H(2)O(2) with Cl(-) ion. Although HOCl is known to play a major role in the human immune system by killing bacteria and other invading pathogens, excessive generation of this oxidant is known to cause damage to tissue. Recently, it was demonstrated that the control of mitochondrial redox balance and oxidative damage is one of the primary functions of mitochondrial NADP(+)-dependent isocitrate dehydrogenase (IDPm) to supply NADPH for antioxidant systems. This study investigated whether the IDPm would be a vulnerable target of HOCl as a purified enzyme and in intact cells. Loss of enzyme activity was observed and the inactivation of IDPm was reversed by thiols. Transfection of HeLa cells with an IDPm small interfering RNA (siRNA) markedly enhanced HOCl-induced oxidative damage to cells. The HOCl-mediated damage to IDPm may result in the perturbation of the cellular antioxidant defense mechanisms and subsequently lead to a pro-oxidant condition.","pmid":"18484410","doi":"10.1080/10715760802098834","url":"https://pubmed.ncbi.nlm.nih.gov/18484410/"},{"id":2156,"title":"Hypothiocyanous acid is a more potent inducer of apoptosis and protein thiol depletion in murine macrophage cells than hypochlorous acid or hypobromous acid.","authors":"Lloyd, Mitchell M; van Reyk, David M; Davies, Michael J; Hawkins, Clare L","year":2008,"date":"2008 Sep 1","journal":"The Biochemical journal","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypohalous acids are generated by activated leucocytes, via the formation of H(2)O(2) and the release of peroxidase enzymes (myeloperoxidase and eosinophil peroxidase). These species are important bactericidal agents, but HOCl (hypochlorous acid) and HOBr (hypobromous acid) have also been implicated in tissue damage in a number of inflammatory diseases. HOSCN (hypothiocyanous acid; cyanosulfenic acid) is a milder, more thiol-specific, oxidant than HOCl or HOBr and as such may be a more potent inducer of cellular dysfunction due to selective targeting of critical thiol residues on proteins. In the present study, HOCl and HOBr are shown to react rapidly with macrophage (J774A.1) cells, resulting in a greater extent of cell lysis compared with HOSCN. However, HOSCN induces apoptosis and necrosis with greater efficacy, and at lower concentrations, than HOCl or HOBr. Apoptosis occurs in conjunction with an increased release of cytochrome c into the cytosol, but no associated increase in caspase activity. Similarly, apoptosis is observed on treating the cells in the presence of a caspase inhibitor, suggesting that it is mediated by a caspase-independent pathway. HOSCN oxidized protein thiols more efficiently than either HOCl or HOBr. The greater efficacy of HOSCN in inducing apoptosis is attributed to selective damage to critical mitochondrial membrane protein thiol groups, resulting in increased permeability and subsequent leakage of cytochrome c into the cytosol. This induction of damage by HOSCN may be of critical importance in people with elevated levels of SCN(-) (thiocyanate ions) arising from cigarette smoking, and plays a role in the pathologies associated with this biological insult.","pmid":"18459943","doi":"10.1042/BJ20080468","url":"https://pubmed.ncbi.nlm.nih.gov/18459943/"},{"id":2157,"title":"Hypochlorous acid damages histone proteins forming 3-chlorotyrosine and 3,5-dichlorotyrosine.","authors":"Kang, Joseph I Jr; Neidigh, Jonathan W","year":2008,"date":"2008 May","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"While the last 30 years chronicles an extensive effort to understand the damage to DNA caused by reactive oxygen species (ROS), little research has examined the chemical damage to the histone proteins found in chromatin. Hypochlorous acid (HOCl), the primary product of activated neutrophils, is known to damage both DNA and proteins. This article describes the use of mass spectrometry to quantitate the formation of 3-chlorotyrosine and 3,5-dichlorotyrosine, stable and unique markers of protein damage caused by HOCl, in the core histone proteins. Our results indicate that up to 25% of the tyrosine in histone proteins become chlorinated by excess HOCl. We also observe significant formation of 3-chlorotyrosine and 3,5-dichlorotyrosine at low HOCl concentrations and short reaction times. We use mass spectrometry to identify the tyrosine residues on each histone protein that are chlorinated based on the observation of chlorine-containing peptides following protease digestion of histone proteins exposed to HOCl. The tyrosine residues preferentially chlorinated by HOCl are generally within three residues of a lysine or histidine residue, further implicating the initial formation of chloramines in the efficient chlorination of tyrosine residues. The methods and results described here should further our understanding of how HOCl produced at sites of inflammation might damage chromatin.","pmid":"18452314","doi":"10.1021/tx7003486","url":"https://pubmed.ncbi.nlm.nih.gov/18452314/"},{"id":2162,"title":"The combined performance of UV light and chlorine during reclaimed water disinfection.","authors":"Montemayor, M; Costan, A; Lucena, F; Jofre, J; Muñoz, J; Dalmau, E; Mujeriego, R; Sala, L","year":2008,"date":"2008","journal":"Water science and technology : a journal of the International Association on Water Pollution Research","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"The combined effects of disinfectant agents on the microbiological quality of reclaimed water produced by two full-scale water reclamation plants in Catalonia, Spain, were examined in this work. All the disinfectant treatments tested led to the absence, or near absence, of E. coli in 100 mL samples of water, with log reductions of more than 3 log u. Hypochlorite reduced the bacterial concentrations. However, ultraviolet light was more effective than hypochlorite at reducing the concentrations of bacteriophages, viruses and pathogenic protozoa such as Cryptosporidium spp. We conclude that a combination of these two disinfectant agents is effective in protecting public health, as each agent acts to a different degree against the different groups of microorganisms studied. Further studies should investigate the combined action of disinfectant agents at water reclamation plants with ultraviolet light equipment in more favourable working conditions in order to assess their capacity to inactivate microorganisms.","pmid":"18413956","doi":"10.2166/wst.2008.206","url":"https://pubmed.ncbi.nlm.nih.gov/18413956/"},{"id":2163,"title":"Loss of 3-chlorotyrosine by inflammatory oxidants: implications for the use of 3-chlorotyrosine as a bio-marker in vivo.","authors":"Whiteman, Matthew; Spencer, Jeremy P E","year":2008,"date":"2008 Jun 20","journal":"Biochemical and biophysical research communications","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Activated neutrophils generate the potent oxidant hypochlorous acid (HOCl) from the enzyme myeloperoxidase (MPO). A proposed bio-marker for MPO-derived HOCl in vivo is 3-chlorotyrosine, elevated levels of which have been measured in several human inflammatory pathologies. However, it is unlikely that HOCl is produced as the sole oxidant at sites of chronic inflammation as other reactive species are also produced during the inflammatory response. The work presented shows that free and protein bound 3-chlorotyrosine is lost upon addition of the pro-inflammatory oxidants, HOCl, peroxynitrite, and acidified nitrite. Furthermore, incubation of 3-chlorotyrosine with activated RAW264.7 macrophages or neutrophil-like HL-60 cells resulted in significant loss of 3-chlorotyrosine. Therefore, at sites of chronic inflammation where there is concomitant ONOO(-) and HOCl formation, it is possible measurement of 3-chlorotyrosine may represent an underestimate of the true extent of tyrosine chlorination. This finding could account for some of the discrepancies reported between 3-chlorotyrosine levels in tissues in the literature.","pmid":"18405660","doi":"10.1016/j.bbrc.2008.03.153","url":"https://pubmed.ncbi.nlm.nih.gov/18405660/"},{"id":2164,"title":"Denture cleansers, soft lining materials and water temperature: what is the effect?","authors":"Handa, Rajesh K; Jagger, Daryll C; Vowles, Richard W","year":2008,"date":"2008 Apr","journal":"Primary dental care : journal of the Faculty of General Dental Practitioners (UK)","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"AIM: To investigate the effect of water temperature, in association with four denture cleansers, on the colour and surface roughness of five soft lining materials. METHOD: Two silicone soft lining materials (Molloplast B and Sofreliner) represented the heat-cured, laboratory-based and chairside materials that are available. The wide range of chairside, acrylic resin-based, temporary soft lining materials was represented by Coe-Soft, Viscogel and Eversoft. An alkaline hypochlorite (Dentural) and three effervescent peroxide solutions with a range of active pH values (Steradent Active Plus, pH 6; Steradent Extra Strength, pH 3; Superdrug Fresh, pH 11) were selected as the cleansers. The denture cleansers were used at two temperatures: 55 degrees C (manufacturers' recommended temperature) and 80 degrees C. The colour of the specimens was evaluated using a colorimeter and the surface roughness was assessed using a three-dimensional, non-contact surface profilometer. This study reported on the effect of using both the higher temperatures and the recommended temperature on the colour and roughness of permanent and temporary soft lining materials. RESULTS AND CONCLUSION: The results of the study showed that the temperature of the water used with denture cleansers might have a detrimental effect on the colour and surface roughness of some permanent and temporary soft lining materials.","pmid":"18397592","doi":"10.1308/135576108784000285","url":"https://pubmed.ncbi.nlm.nih.gov/18397592/"},{"id":2167,"title":"The role of chloride anion and CFTR in killing of Pseudomonas aeruginosa by normal and CF neutrophils.","authors":"Painter, Richard G; Bonvillain, Ryan W; Valentine, Vincent G; Lombard, Gisele A; LaPlace, Stephanie G; Nauseef, William M; Wang, Guoshun","year":2008,"date":"2008 Jun","journal":"Journal of leukocyte biology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Chloride anion is essential for myeloperoxidase (MPO) to produce hypochlorous acid (HOCl) in polymorphonuclear neutrophils (PMNs). To define whether chloride availability to PMNs affects their HOCl production and microbicidal capacity, we examined how extracellular chloride concentration affects killing of Pseudomonas aeruginosa (PsA) by normal neutrophils. PMN-mediated bacterial killing was strongly dependent on extracellular chloride concentration. Neutrophils in a chloride-deficient medium killed PsA poorly. However, as the chloride level was raised, the killing efficiency increased in a dose-dependent manner. By using specific inhibitors to selectively block NADPH oxidase, MPO, and cystic fibrosis transmembrane conductance regulator (CFTR) functions, neutrophil-mediated killing of PsA could be attributed to three distinct mechanisms: CFTR-dependent and oxidant-dependent; chloride-dependent but not CFTR- and oxidant-dependent; and independent of any of the tested factors. Therefore, chloride anion is involved in oxidant- and nonoxidant-mediated bacterial killing. We previously reported that neutrophils from CF patients are defective in chlorination of ingested bacteria, suggesting that the chloride channel defect might impair the MPO-hydrogen peroxide-chloride microbicidal function. Here, we compared the competence of killing PsA by neutrophils from normal donors and CF patients. The data demonstrate that the killing rate by CF neutrophils was significantly lower than that by normal neutrophils. CF neutrophils in a chloride-deficient environment had only one-third of the bactericidal capacity of normal neutrophils in a physiological chloride environment. These results suggest that CFTR-dependent chloride anion transport contributes significantly to killing PsA by normal neutrophils and when defective as in CF, may compromise the ability to clear PsA.","pmid":"18353929","doi":"10.1189/jlb.0907658","url":"https://pubmed.ncbi.nlm.nih.gov/18353929/"},{"id":2169,"title":"The influence of dental unit waterline cleaners on composite-to-dentin bond strengths.","authors":"Ritter, André V; Ghaname, Eduardo; Leonard, Ralph H","year":2008,"date":"2008 Jan-Feb","journal":"Dental assistant (Chicago, Ill. : 1994)","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"BACKGROUND: One approach to controlling dental unit waterline (DUWL) contamination by microorganisms is the addition of chemical cleaners to the treatment water. Yet, there is concern that these cleaners might affect the bonding of resin-based composites to enamel and dentin. The authors evaluated the influence of DUWL cleaners on composite-to-dentin bond strengths. METHODS: The authors tested the strength of resin-based composite bonded to dentin in specimens treated with distilled water (control) or one of four cleaners. They tested a total-etch adhesive, a self-etching primer/adhesive and an experimental self-etching primer/ adhesive. The authors stored the specimens for 24 hours at 37 C and tested them to determine their bond strengths. RESULTS: The mean shear bond strengths (SBSs) varied according to the cleaner and adhesive used, ranging from 14.7 to 21.9 megapascals. However, the authors found no statistically significant differences and/or interactions between mean SBSs of specimens treated with the various DUWL cleaners and adhesives (P > or = .05). CONCLUSIONS: The tested DUWL cleaners did not significantly influence composite-to-dentin bond strengths for the total-etch adhesive and self-etching primer/adhesives used in this study. CLINICAL IMPLICATIONS. The conclusions imply that bonding of resin-based composites to dentin is not affected by the cleaners tested when they are used to treat DUWL contamination.","pmid":"18333599","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/18333599/"},{"id":2170,"title":"Effect of N-chloroamino acids on the erythrocyte.","authors":"Robaszkiewicz, A; Bartosz, G; Soszyński, M","year":2008,"date":"2008 Jan","journal":"Free radical research","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Amino acids present in blood plasma may be targets for oxidation and chlorination by HOCl/OCl(-). N-Chloroamino acids have been reported to be less reactive, but more selective than HOCl/OCl(-) in their reactions; therefore, they may act as secondary mediators of HOCl/OCl(-)-induced injury. This study compared the effects of five N-chloroamino acids (AlaCl, LysCl, SerCl, AspCl and PheCl) on erythrocytes with the action of HOCl/OCl(-). The N-chloroamino acids differed in stability and reactivity. They had a weaker haemolytic action than HOCl/OCl(-); HOCl/OCl(-), AlaCl and PheCl increased osmotic fragility of erythrocytes at a concentration of 1 mm. Oxidation of glutathione, formation of protein-glutathione mixed disulphides and efflux of GSSG from erythrocytes were observed for erythrocytes treated with all the employed chloroderivatives, while increased oxidation of 2',7'-dichlorofluorescin was detected only after treatment of the cells with 1 mm HOCl/OCl(-), AlaCl and PheCl. Generally, the reactivity of at least some N-chloroamino acids may be not much lower with respect to HOCl/OCl(-).","pmid":"18324521","doi":"10.1080/10715760701774873","url":"https://pubmed.ncbi.nlm.nih.gov/18324521/"},{"id":2175,"title":"Quantifying changes in the thiol redox proteome upon oxidative stress in vivo.","authors":"Leichert, Lars I; Gehrke, Florian; Gudiseva, Harini V; Blackwell, Tom; Ilbert, Marianne; Walker, Angela K; Strahler, John R; Andrews, Philip C; Jakob, Ursula","year":2008,"date":"2008 Jun 17","journal":"Proceedings of the National Academy of Sciences of the United States of America","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"Antimicrobial levels of reactive oxygen species (ROS) are produced by the mammalian host defense to kill invading bacteria and limit bacterial colonization. One main in vivo target of ROS is the thiol group of proteins. We have developed a quantitative thiol trapping technique termed OxICAT to identify physiologically important target proteins of hydrogen peroxide (H(2)O(2)) and hypochlorite (NaOCl) stress in vivo. OxICAT allows the precise quantification of oxidative thiol modifications in hundreds of different proteins in a single experiment. It also identifies the affected proteins and defines their redox-sensitive cysteine(s). Using this technique, we identified a group of Escherichia coli proteins with significantly (30-90%) oxidatively modified thiol groups, which appear to be specifically sensitive to either H(2)O(2) or NaOCl stress. These results indicate that individual oxidants target distinct proteins in vivo. Conditionally essential E. coli genes encode one-third of redox-sensitive proteins, a finding that might explain the bacteriostatic effect of oxidative stress treatment. We identified a select group of redox-regulated proteins, which protect E. coli against oxidative stress conditions. These experiments illustrate that OxICAT, which can be used in a variety of different cell types and organisms, is a powerful tool to identify, quantify, and monitor oxidative thiol modifications in vivo.","pmid":"18287020","doi":"10.1073/pnas.0707723105","url":"https://pubmed.ncbi.nlm.nih.gov/18287020/"},{"id":2177,"title":"Myeloperoxidase-catalyzed chlorination: the quest for the active species.","authors":"Ramos, Daniel R; García, M Victoria; Canle L, Moisés; Santaballa, J Arturo; Furtmüller, Paul G; Obinger, Christian","year":2008,"date":"2008 May-Jun","journal":"Journal of inorganic biochemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Myeloperoxidase (MPO) is a dominating enzyme of circulating polymorphonuclear neutrophils that catalyzes the two-electron oxidation of chloride, thereby producing the strong halogenating agent hypochlorous acid (ClO(-)/HOCl). In absence of MPO the tripeptide Pro-Gly-Gly reacts with HOCl faster than the amino acid taurine (2-aminoethanesulfonic acid, Tau), while the MPO-mediated chlorination shows reverse order. A comparative study of the enzymatic oxidation of both substrates at pH 4.0-6.0, varying H2O2 concentration is presented. Initial and equilibrium rates studies have been carried on, reaction rates in the latter being slower due to the chemical equilibrium between MPO-I and MPO-II-HO2. A maximum of chlorination rate is observed for Pro-Gly-Gly and Tau when [H2O2] approximately 0.3-0.7 mM and pH approximately 4.5-5.0. Several mechanistic possibilities are considered, the proposed one implies that chlorination takes place via two pathways. One, for bulkier substrates, involves chlorination by free HOCl outside the heme cavity; ClO(-) is released from the active center, diffuses away the heme cavity, and undergoes protonation to HOCl. The other implies the existence of compound I-Cl(-) complex (MPO-I-Cl), capable of chlorinating smaller substrates in the heme pocket. Electronic structure calculations show the size of Pro-Gly-Gly comparable to the available gap in the substrate channel, this tripeptide being unable to reach the active site, and its chlorination is only possible by free HOCl outside the enzyme.","pmid":"18279963","doi":"10.1016/j.jinorgbio.2008.01.003","url":"https://pubmed.ncbi.nlm.nih.gov/18279963/"},{"id":2180,"title":"Effectiveness of selected premilking teat-cleaning regimes in reducing teat microbial load on commercial dairy farms.","authors":"Gibson, H; Sinclair, L A; Brizuela, C M; Worton, H L; Protheroe, R G","year":2008,"date":"2008 Mar","journal":"Letters in applied microbiology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"AIMS: To determine the effectiveness of premilking teat-cleaning regimes in reducing the teat microbial load and effect on milk quality. METHODS AND RESULTS: The effectiveness of several premilking teat-cleaning regimes in reducing teat microbial load was assessed using 40 cows on each of the four commercial UK dairy farms with herringbone parlours during two sampling periods. In the first experiment, all the treatments reduced teat total viable count (TVC), but there was no significant difference between the hypochlorite wash and dry wipe, iodine dip and dry and alcohol-medicated wipe or dry wipe alone. In the second experiment, the chlorine wash and dry wipe was significantly more effective in reducing teat TVC than a water wash and dry, chlorine dip and dry or a dry wipe. There was no relationship between cleaning regime and milk TVC, Enterobacteriaceae or Escherichia coli levels. CONCLUSIONS: All of the cleaning techniques studied reduced teat microbial load, however, the chlorine wash and dry was the most effective. SIGNIFICANCE AND IMPACT OF THE STUDY: The premilking teat-cleaning techniques studied reduced the teat microbial load and therefore reduced the potential for milk contamination; however, a wash including an effective disinfectant followed by a dry wipe was the most effective.","pmid":"18179447","doi":"10.1111/j.1472-765X.2007.02308.x","url":"https://pubmed.ncbi.nlm.nih.gov/18179447/"},{"id":2185,"title":"Comparison of the inactivation of Bacillus subtilis spores and MS2 bacteriophage by MIOX, ClorTec and hypochlorite.","authors":"Clevenger, T; Wu, Y; DeGruson, E; Brazos, B; Banerji, S","year":2007,"date":"2007 Dec","journal":"Journal of applied microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"AIMS: To compare the disinfection ability of two widely used electrolytic generation systems (ClorTec and MIOX) and the conventional chlorine disinfectant (sodium hypochlorite) using three strains of Bacillus subtilis spores and MS2 bacteriophage. METHODS AND RESULTS: Three B. subtilis aerobic spore strains (ATCC1A1, 35021 and 35946) and the bacteriophage MS2 (ATCC 15597-B1) were propagated and sporulated. Four indicator organisms were exposed to four disinfectant treatments for comparing the effectiveness of inactivation: hypochlorite, ClorTec, MIOX and MIOX-anode. The results indicated that the two electrolytic generation systems were as effective as the conventional chlorination for the inactivation of micro-organisms used. Some data points showed the variation using anova analysis, in which the inactivation of MIOX and ClorTec was higher than that of hypochlorite. CONCLUSIONS: The ClorTec and MIOX systems are quite similar to hypochlorite in the inactivation-effectiveness for aerobic spores and bacteriophage in drinking water. SIGNIFICANCE AND IMPACT OF THE STUDY: Laboratory-scale investigation proved that gaseous chlorine could be replaced by either ClorTec or MIOX systems for the drinking water treatment utilities, which still could maintain the same disinfection efficiency.","pmid":"18045412","doi":"10.1111/j.1365-2672.2007.03481.x","url":"https://pubmed.ncbi.nlm.nih.gov/18045412/"},{"id":2186,"title":"Toxicogenomic response to chlorination includes induction of major virulence genes in Staphylococcus aureus.","authors":"Chang, Matthew Wook; Toghrol, Freshteh; Bentley, William E","year":2007,"date":"2007 Nov 1","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Despite the widespread use of chlorination for microbial control in aqueous environments, cellular response mechanisms of human pathogens, such as Staphylococcus aureus, against chlorination remain unknown. In this work, genome-wide transcriptional analysis was performed to elucidate cellular response of S. aureusto hypochlorous acid, an active antimicrobial product of chlorination in aqueous solution. Our results suggest that hypochlorous acid repressed transcription of genes involved in cell wall synthesis, membrane transport, protein synthesis, and primary metabolism, while amino acid synthesis genes were induced. Furthermore, hypochlorous acid induced transcription of genes encoding major virulence factors of S. aureus, such as exotoxins, hemolysins, leukocidins, coagulases, and surface adhesion proteins, which all play essential roles in staphylococcal virulence. This work implies that chlorination may stimulate production of virulence factors, which provides new insight into host-pathogen interactions and effects of chlorine application for microbial control.","pmid":"18044543","doi":"10.1021/es070929k","url":"https://pubmed.ncbi.nlm.nih.gov/18044543/"},{"id":2192,"title":"Myricitrin as a substrate and inhibitor of myeloperoxidase: implications for the pharmacological effects of flavonoids.","authors":"Meotti, Flavia Carla; Senthilmohan, Revathy; Harwood, D Tim; Missau, Fabiana Cristina; Pizzolatti, Moacir G; Kettle, Anthony J","year":2008,"date":"2008 Jan 1","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Flavonoids are increasingly being ingested by the general population as chemotherapeutic and anti-inflammatory agents. They are potentially toxic because of their conversion to free radicals and reactive quinones by peroxidases. Little detailed information is available on how flavonoids interact with myeloperoxidase, which is the predominant peroxidase present at sites of inflammation. This enzyme uses hydrogen peroxide to oxidize chloride to hypochlorous acid, as well as to produce an array of reactive free radicals from organic substrates. We investigated how the flavonoid myricitrin is oxidized by myeloperoxidase and how it affects the activities of this enzyme. Myricitrin was readily oxidized by myeloperoxidase in the presence of hydrogen peroxide. Its main oxidation product was a dimer that underwent further oxidation. In the presence of glutathione, myricitrin was oxidized to a hydroquinone that was conjugated to glutathione. When myeloperoxidase oxidized myricitrin and related flavonoids it became irreversibly inactivated. The number of hydroxyl groups in the B ring of the flavonoids and the presence of a free hydroxyl m-phenol group in the A ring were important for the inhibitory effects. Less enzyme inactivation occurred in the presence of chloride. Neutrophils also oxidized myricitrin to dimers in a reaction that was partially dependent on myeloperoxidase. Myricitrin did not affect the production of hypochlorous acid by neutrophils. We conclude that myricitrin will be oxidized by neutrophils at sites of inflammation to produce reactive free radicals and quinones. It is unlikely to affect hypochlorous acid production by neutrophils.","pmid":"17963707","doi":"10.1016/j.freeradbiomed.2007.09.017","url":"https://pubmed.ncbi.nlm.nih.gov/17963707/"},{"id":2197,"title":"Study of sugar beet cyst nematode life cycle using plant tissue culture method.","authors":"Shadmehr, Atena; Nouroozi, Payman; Garousi, Ghasemali; Ahmadi, Ali-Reza","year":2007,"date":"2007 Sep 1","journal":"Pakistan journal of biological sciences : PJBS","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"After optimization of sterilizing of cyst and larva second stage of Heterodera schachtii, possibility of using nematode on seedlings of sugar beet (Beta vulgaris L.) in in vitro conditions were studied using sterilized larvae of beet cyst nematode. For this purpose, non sterile cysts were extracted from infected soil and hatched into zinc chloride solution with concentration of 0.5 g L(-1). Then, for preparation of sterile second stage larvae, several sterilizing treatments were used. Mean comparisons were performed between sterilized live larvae number by Duncan's method. Results showed that 70% ethanol for 1 min followed by 2.5% hypochlorite sodium for 5 minutes and 0.1% hypochlorite sodium for 20 min were best treatments for disinfecting cysts and larvae, respectively. In parallel, two nematode susceptible sugar beet varieties were applied to produce seedlings in in vitro culture. PG(oB) medium containing different hormonal compositions was used for producing of hairy roots and inoculation of seedling with sterilized larvae. After nematode inoculation tests, daily observations were done by counting cysts and stained roots and larvae under stereomicroscope. Between 5-12 cysts formed on the roots of each seedling from two varieties 40 days after inoculation. As a result, it seems that this technique can be used for sugar beet germplasm evaluation to screen nematode resistant genotypes in in vitro controlled condition.","pmid":"19090198","doi":"10.3923/pjbs.2007.2910.2914","url":"https://pubmed.ncbi.nlm.nih.gov/19090198/"},{"id":2199,"title":"Ultraviolet spectrophotometric determination of nitrate: detecting nitrification rates and inhibition.","authors":"Kelly, Richard T 2nd; Love, Nancy G","year":2007,"date":"2007 Jul","journal":"Water environment research : a research publication of the Water Environment Federation","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Simple methods that rapidly detect nitrification inhibition are needed to enforce pretreatment programs and prevent upsets. The objective of this study was to demonstrate a rapid method for measuring nitrification inhibition by using nitrate generation rates (NGRs) coupled with direct UV detection of nitrate. The NGRs were measured with UV spectrophotometry at wavelengths between 225 and 240 nm, without chemical manipulation, and verified against ion chromatography. The method was shown to quickly and accurately measure nitrate concentrations after correcting for nitrite interference. Cadmium, hypochlorite and 1-chloro-2,4-dintrobenzene (CDNB) were tested for their ability to cause nitrification inhibition using this method. The CDNB was found to cause a correctable interference with the test, while hypochlorite provided an uncorrectable interference. Used as a batch method coupled with biotic and abiotic controls, this approach can be deployed at full-scale treatment plants as a relatively rapid (1.5 hours) means of identifying nitrification-inhibiting wastewaters.","pmid":"17710926","doi":"10.2175/106143007x156682","url":"https://pubmed.ncbi.nlm.nih.gov/17710926/"},{"id":2204,"title":"Chlorination products: emerging links with allergic diseases.","authors":"Bernard, A","year":2007,"date":"2007","journal":"Current medicinal chemistry","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"Exposure of the human population to chlorination products has considerably increased during the 20(th) century especially after the 1960s with the development of public and leisure pools. The present article summarizes current knowledge regarding the human exposure to chlorination products and reviews studies suggesting that these chemicals might be involved in the development or exacerbation of allergic diseases. Populations regularly in contact with chlorination products such as swimmers, lifeguards or workers using chlorine as cleaning or bleaching agent show increased risks of allergic diseases or of respiratory disorders frequently associated with allergy. Experimental evidence suggests that chlorination products promote allergic sensitization by compromising the permeability or the immunoregulatory function of epithelial barriers. These findings led to the chlorine hypothesis proposing that the rise of allergic diseases could result less from the declining exposure to microbial agents (the hygiene hypothesis) than from the increasing and largely uncontrolled exposure to products of chlorination, the most widely used method to achieve hygiene in the developed world. Giving the increasing popularity of water recreational areas, there is an obvious need to assess the effects of chlorine-based oxidants on human health and their possible implication in the epidemic of allergic diseases.","pmid":"17627515","doi":"10.2174/092986707781058940","url":"https://pubmed.ncbi.nlm.nih.gov/17627515/"},{"id":2205,"title":"Inhibition of the myeloperoxidase chlorinating activity by non-steroidal anti-inflammatory drugs: flufenamic acid and its 5-chloro-derivative directly interact with a recombinant human myeloperoxidase to inhibit the synthesis of hypochlorous acid.","authors":"Van Antwerpen, Pierre; Dufrasne, François; Lequeux, Mathieu; Boudjeltia, Karim Zouaoui; Lessgyer, Ilham; Babar, Sajida; Moreau, Patrick; Moguilevsky, Nicole; Vanhaeverbeek, Michel; Ducobu, Jean; Nève, Jean","year":2007,"date":"2007 Sep 10","journal":"European journal of pharmacology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The present in vitro study was designed to assess the inhibition of the myeloperoxidase (MPO)/H(2)O(2)/Cl(-) system by several non steroidal anti-inflammatory drugs (NSAIDs) of the oxicam family and of nimesulide and to compare their effect with flufenamic acid in order to investigate their influence on the chlorinating activity of MPO as a protective mechanism during chronic inflammatory syndromes. The inhibition of the system was assessed by measurement of the taurine chlorination while the accumulation of compound II was used to investigate the mechanism of inhibition. The oxidation products of NSAIDs by the MPO/H(2)O(2)/Cl(-) system were identified and flufenamic acid and derivatives were also assessed in the inhibition of LDL oxidation in two models. Flufenamic acid (IC(50) = 1.1+/-0.3 microM) is the most efficient inhibitor of the MPO/H(2)O(2)/Cl(-) system and nimesulide (IC(50) = 2.1+/-0.3 microM) is more active than the other NSAIDs of the oxicam family (IC(50) = 8-12 microM). The accumulation of compound II revealed that flufenamic acid acts as an electron donor while the other NSAIDs are antagonists of chloride anions. The identification of the oxidation products confirms that flufenamic behaves like an electron donor and is directly oxidized in the 5-hydroxy-derivative but gives also the 5-chloro-derivative which similarly inhibits the MPO/H(2)O(2)/Cl(-) system. Flufenamic acid has the best inhibiting activity towards the MPO/H(2)O(2)/Cl(-) system. However, in models that assess the LDL oxidation, flufenamic acid and its derivatives were unable to properly inhibit MPO activity as the enzyme is adsorbed on macrostructures such as LDL molecules.","pmid":"17610876","doi":"10.1016/j.ejphar.2007.05.057","url":"https://pubmed.ncbi.nlm.nih.gov/17610876/"},{"id":2207,"title":"S-allylcysteine scavenges singlet oxygen and hypochlorous acid and protects LLC-PK(1) cells of potassium dichromate-induced toxicity.","authors":"Medina-Campos, Omar Noel; Barrera, Diana; Segoviano-Murillo, Sabina; Rocha, Diana; Maldonado, Perla D; Mendoza-Patiño, Nicandro; Pedraza-Chaverri, José","year":2007,"date":"2007 Oct","journal":"Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"It has been found that S-allylcysteine (SAC), a garlic-derived compound, has in vivo and in vitro antioxidant properties. In addition, it is known that SAC is able to scavenge different reactive oxygen or nitrogen species including superoxide anion (O(2)(-)), hydrogen peroxide (H(2)O(2)), hydroxyl radical (OH()), and peroxynitrite anion (ONOO(-)) although the IC(5O) values for each reactive species has not been calculated and the potential ability of SAC to scavenge singlet oxygen ((1)O(2)) and hypochlorous acid (HOCl) has not been explored. The purposes of this work was (a) to explore the potential ability of SAC to scavenge (1)O(2) and HOCl, (b) to further characterize the O(2)(-), H(2)O(2), OH(), and ONOO(-) scavenging ability of SAC by measuring the IC(50) values using in vitro assays, and (c) to explore the potential ability of SAC to ameliorate the potassium dichromate (K(2)Cr(2)O(7))-induced cytotoxicity in LLC-PK1 cells in which oxidative stress is involved. The scavenging activity was compared against the following reference compounds: N-acetylcysteine for O(2)(-), sodium pyruvate for H(2)O(2), dimethylthiourea for OH(), lipoic acid and glutathione for (1)O(2), lipoic acid for HOCl, and penicillamine for ONOO(-). It was found that SAC was able to scavenge concentration-dependently all the species assayed with the following IC(5O) (mean+/-SEM, mM): O(2)(-) (14.49+/-1.67), H(2)O(2) (68+/-1.92), OH() (0.68+/-0.06), (1)O(2) (1.93+/-0.27), HOCl (2.86+/-0.15), and ONOO(-) (0.80+/-0.05). When the ability of SAC to scavenge these species was compared to those of the reference compounds it was found that the efficacy of SAC (a) to scavenge O(2)(-), H(2)O(2), OH(), and ONOO(-) was lower, (b) to scavenge HOCl was similar, and (c) to scavenge (1)O(2) was higher. In addition, it was found that SAC was able to prevent K(2)Cr(2)O(7)-induced toxicity in LLC-PK1 cells in culture. It was showed for the first time that SAC is able to scavenge (1)O(2) and HOCl and to ameliorate the K(2)Cr(2)O(7)-induced toxicity.","pmid":"17576034","doi":"10.1016/j.fct.2007.05.002","url":"https://pubmed.ncbi.nlm.nih.gov/17576034/"},{"id":2208,"title":"Dermacyn on the infected foot ulcers of 10 patients.","authors":"Kaehn, K","year":2007,"date":"2007 May","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"","pmid":"17552409","doi":"10.12968/jowc.2007.16.5.27035","url":"https://pubmed.ncbi.nlm.nih.gov/17552409/"},{"id":2210,"title":"Molecular monitoring of disinfection efficacy using propidium monoazide in combination with quantitative PCR.","authors":"Nocker, Andreas; Sossa, Katherine E; Camper, Anne K","year":2007,"date":"2007 Aug","journal":"Journal of microbiological methods","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"One of the major drawbacks of DNA-based microbial diagnostics is its inability to discriminate between live and dead bacteria. Due to the persistence of DNA in the environment after cells have lost their viability, DNA-based assays cannot assess pathogenic risk since signals can originate from both live and dead cells. Presented here is a potential application of the novel chemical propidium monoazide (PMA), which results in the selective suppression of DNA detection from dead cells. PMA can only penetrate dead cells with permeabilized cell membranes. Upon intercalation into the DNA, covalent crosslinkage of PMA to DNA is achieved through light exposure. This modification prevents the DNA from being amplified by PCR. The method, in combination with quantitative PCR as a diagnostic tool, successfully monitored the disinfection efficacy of hypochlorite, benzalkonium and heat on several model pathogens. Threshold cycle numbers increased with increasing disinfection strength after PMA treatment of samples compared to non-PMA treated samples. With some disinfectant-specific differences, monitoring viability loss with membrane integrity as an indicator seemed to be more conservative than monitoring viability loss with plate counts. Loss of viability after short UV-exposure could not be monitored with PMA as UV light affects viability by inducing DNA damage without directly affecting membrane permeability.","pmid":"17544161","doi":"10.1016/j.mimet.2007.04.014","url":"https://pubmed.ncbi.nlm.nih.gov/17544161/"},{"id":2211,"title":"Detection and characterization of N-alpha-chloramines by electrospray tandem mass spectrometry.","authors":"Raftery, Mark J","year":2007,"date":"2007 Jul 15","journal":"Analytical biochemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Hypochlorous acid (HOCl) is a major product of activated neutrophils and may be important in antimicrobial activities of cells by oxidation or chlorination of susceptible amino acids. Three major peaks separated using C18 reverse phase-high-performance liquid chromatography RP-HPLC after incubation of leucine enkephalin (LeuEnk) with HOCl. Electrospray mass spectrometry showed masses of m/z 556.2, 590.2, and 624.4 corresponding to unmodified LeuEnk and peptides altered by addition of one or two chlorines (Cl). Formation of stable N-alpha-chloramines was indicated because the chlorinated peptides were readily reduced with the physiological reductants glutathione and ascorbic acid to LeuEnk (m/z 556.2) within 10 min. Sequence-specific ions observed in product ion spectra of single-charged monochlorinated and dichlorinated peptides were consistent with modification of the N-terminal amine. There was no evidence for chlorination of the Tyr aromatic ring in any spectra. Similar RP-HPLC profiles were obtained after oxidation of des-Tyr1-LeuEnk (GGFL) with the masses of the major products being m/z 393.3, 427.2, and 461.1. These were identified as unmodified GGFL, N-alpha-Cl-GGFL, and N-alpha-Cl2-GGFL based on comparison of tandem mass spectra. Oxidation of Met and formation of disulfide dimers was observed after incubation of either N-alpha-Cl-LeuEnk or N-alpha-Cl2-LeuEnk with a protein, indicating that both peptide N-alpha-chloramines were able to readily modify sulfur-containing amino acids within proteins. These data indicate initial formation of stable N-alpha-chorinated peptides after incubation with HOCl and suggest that N-alpha-chlorinated peptides may exist for some hours in the absence of physiological reducing agents or sulfur-containing amino acids.","pmid":"17537392","doi":"10.1016/j.ab.2007.04.016","url":"https://pubmed.ncbi.nlm.nih.gov/17537392/"},{"id":2212,"title":"Proteomic analysis of a hypochlorous acid-tolerant Listeria monocytogenes cultural variant exhibiting enhanced biofilm production.","authors":"Folsom, James P; Frank, Joseph F","year":2007,"date":"2007 May","journal":"Journal of food protection","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Following exposure of Listeria monocytogenes Scott A (SA) to hypochlorous acid, rough colony variants were identified that were tolerant of hypochlorous acid and produced increased amounts of biofilm. A derivative of one of these variants was smooth, produced even more biofilm, and exhibited greater biofilm chlorine resistance. The objective of this research was to compare the protein expression of a cultural variant to SA and to identify proteins that might be associated with biofilm production and chlorine tolerance. Suspension chlorine tolerance for several cultural variants (SAR, SAR5, and SBS) was determined by exposure to 60 to 120 ppm of hypochlorous acid for 5 min. Hypochlorous acid tolerance of biofilms was determined after growing biofilms on stainless steel and then exposing them to 200 ppm of hypochlorous acid for 5 min. All cultural variants were able to survive 120 ppm of hypochlorous acid in suspension. There was little difference in the hypochlorous acid tolerance of the cultural variant planktonic cells. The cultural variants produced greater amounts of biofilm than the common form of L. monocytogenes and were more tolerant of hypochlorous acid. The SBS variant was selected for proteomic comparison because it was the variant that produced the most biofilm and was the most tolerant of hypochlorous acid when grown as a biofilm. Protein expression of planktonic and biofilm cells of SBS was compared to SA by two-dimensional difference gel electrophoresis. The 50s ribosomal protein, L10, was down-regulated in biofilm SBS. Other proteins down-regulated in planktonic SBS were the peroxide resistance protein (Dpr) and a sugar-binding protein (LMO0181). This sugar-binding protein was also up-regulated in biofilm SBS. One protein spot down-regulated in planktonic SBS contained both 50s ribosomal protein L7/L12 and an unknown protein (LM01888).","pmid":"17536671","doi":"10.4315/0362-028x-70.5.1129","url":"https://pubmed.ncbi.nlm.nih.gov/17536671/"},{"id":2221,"title":"\"Solvent effects on the silylation-gas chromatography-mass spectrometric determination of natural and synthetic estrogenic steroid hormones\" Comment on \"Formation of chlorinated estrones via hypochlorous disinfection of wastewater effluent containing estrone\" by Hideyuki Nakamura, Ryoko Kuruto-Niwa, Mitsuo Uchida and Yoshiyasu Terao [Chemosphere 66 (2007) 1441-1448].","authors":"Zuo, Yuegang; Lin, Yuejuan","year":2007,"date":"2007 Oct","journal":"Chemosphere","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"17499335","doi":"10.1016/j.chemosphere.2007.03.065","url":"https://pubmed.ncbi.nlm.nih.gov/17499335/"},{"id":2227,"title":"Modification of tryptophan and methionine residues is implicated in the oxidative inactivation of surfactant protein B.","authors":"Manzanares, Dahis; Rodriguez-Capote, Karina; Liu, Suya; Haines, Thomas; Ramos, Yudith; Zhao, Lin; Doherty-Kirby, Amanda; Lajoie, Gilles; Possmayer, Fred","year":2007,"date":"2007 May 8","journal":"Biochemistry","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Exposing BLES (bovine lipid extract surfactant), a clinical surfactant, to reactive oxygen species (ROS) alters surfactant protein B (SP-B), as indicated by Coomassie Blue staining, silver staining, and Western analysis. Hypochlorous acid (HOCl) treatment leads to elevated maximum surface tension (gammamax) and a deterioration in minimum gamma (gammamin) during surface area cycling. Fenton reaction resulted in immediate increases in gammamin and gammamax. Intrinsic fluorescence measurements indicated Fenton, but not HOCl, induced conversion of Trp9 of SP-B to hydroxyTrp (OHTrp), N-formylkynurenine (NFKyn), and kynurenine (Kyn). Electrospray ionization mass spectrometry (ESI-MS) revealed molecular weight alterations consistent with oxidation of Met (HOCl, Fenton) and Trp (Fenton) residues. Oxidative alterations to Met29 and Met65 (HOCl, Fenton) and to Trp9 (OHTrp with HOCL and NFKyn plus Kyn with Fenton) were confirmed by matrix-assisted laser desorption mass spectrometry (MALDI-MS) studies on SP-B tryptic fragments. Some Met oxidation was observed with control SP-B. When taken together with captive bubble tensiometer measurements, these studies suggest that Met oxidation of SP-B by HOCl or Fenton interferes with phospholipid respreading during compression-expansion of surfactant films, while Fenton oxidation, which produces more extensive Met oxidation and disruption of the indole ring of Trp9, further abrogated the ability of such films to attain low surface tensions during compression. These studies provide insight into the manner by which ROS generated during acute lung injury and the acute respiratory distress syndrome act to inhibit not only endogenous surfactant but also therapeutic surfactants administered to counteract these conditions.","pmid":"17425286","doi":"10.1021/bi062304p","url":"https://pubmed.ncbi.nlm.nih.gov/17425286/"},{"id":2233,"title":"Investigation of pathways of advanced glycation end-products accumulation in macrophages.","authors":"Nagai, Ryoji; Fujiwara, Yukio; Mera, Katsumi; Otagiri, Masaki","year":2007,"date":"2007 Apr","journal":"Molecular nutrition & food research","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Advanced glycation end-products (AGE) play a role in the pathogenesis of several diseases, including diabetic complications and atherosclerosis. In atherosclerotic lesions of human aortas, AGE are localized in the extracellular matrix and intracellularly in foam cells. Two interpretations are possible for AGE accumulation inside macrophages, one is endocytic uptake of extracellular AGE-proteins by scavenger receptors; the other is intracellular AGE formation inside the macrophages. In the present study, we determined the pathways involved in AGE accumulation inside macrophages. RAW 264.7 cells, a murine macrophage cell line, incubated with BSA and 1600 mM glucose for 40 weeks, recognized heavily modified AGE- BSA. In contrast, the cells showed no ligand activity for mildly modified AGE-BSA, prepared by incubating BSA with 50 mM glucose for 24 weeks. Nepsilon-(carboxymethyl)lysine (CML)-modified proteins of about 65 kDa were detected in human monocyte-derived macrophages incubated for 7 days with 30 mM glucose and phorbol myristate acetate. Furthermore, CML was generated when glycated protein was incubated with hypochloric acid. Taken together, our results indicate that AGE detected inside foam cells in atherosclerotic lesions are generated intracellularly rather than representing endocytic uptake of extracellular AGE-proteins by scavenger receptors.","pmid":"17390398","doi":"10.1002/mnfr.200600255","url":"https://pubmed.ncbi.nlm.nih.gov/17390398/"},{"id":2234,"title":"Comparison of rinsing and sanitizing procedures for reducing bacterial pathogens on fresh cantaloupes and bell peppers.","authors":"Alvarado-Casillas, S; Ibarra-Sánchez, S; Rodríguez-García, O; Martínez-Gonzáles, N; Castillo, A","year":2007,"date":"2007 Mar","journal":"Journal of food protection","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Increased consumption of fruits and vegetables is linked to health benefits but also to an increase in the number of outbreaks of foodborne illness. To determine the effectiveness of different sanitizing treatments for reducing bacterial pathogens on fresh produce, fresh cantaloupes and bell peppers were harvested and inoculated with suspensions of Salmonella Typhimurium and Escherichia coli O157:H7. The inoculated fruits were treated with water wash alone or were washed and then waxed or rinsed with 200 mg/liter hypochlorite, 10% Ca(OH)2, or 2% lactic acid solutions applied by dipping for 15 s or spraying for 15 s. Preliminary experiments with chlorine treatments indicated that spraying with a 200, 600, or 1,000 mg/liter hypochlorite solution reduced populations of both pathogens by 2.1 to 2.6 and 1.5 to 2.1 log CFU for Salmonella Typhimurium and E. coli O157:H7, respectively. In general, no differences were observed between chlorine solutions without pH adjustment (pH 9.2) and those with pH adjusted to 6.0. When different wash regimes were applied to inoculated cantaloupes or bell peppers, water wash alone produced significantly lower counts of both pathogens on bell peppers in comparison to untreated controls. However, this reduction was not observed on cantaloupes, indicating a possible surface effect. Application of 2% L-lactic acid by spray was the treatment that resulted in the lowest bacterial counts on both cantaloupes and bell peppers. This treatment did not produce any deleterious change in the sensorial characteristics of the products tested. None of the pathogens studied was able to grow during refrigerated storage (5 degrees C for cantaloupes and 10 degrees C for bell peppers), although numbers close to the detection limit of the counting method were found in randomly tested individual samples at days 14 and 28 of storage, indicating that these pathogens can survive for long periods on the produce surface. These results indicate that selected produce commodities could be sanitized at the packing facility. However, these interventions should not be applied as a replacement for but only as a complement to good hygiene practices.","pmid":"17388055","doi":"10.4315/0362-028x-70.3.655","url":"https://pubmed.ncbi.nlm.nih.gov/17388055/"},{"id":2236,"title":"Chlorination of lignin by ubiquitous fungi has a likely role in global organochlorine production.","authors":"Ortiz-Bermúdez, Patricia; Hirth, Kolby C; Srebotnik, Ewald; Hammel, Kenneth E","year":2007,"date":"2007 Mar 6","journal":"Proceedings of the National Academy of Sciences of the United States of America","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Soils and decayed plant litter contain significant quantities of chlorinated aromatic polymers that have a natural but largely unknown origin. We used cupric oxide ligninolysis coupled with gas chromatography/mass spectrometry to show that Curvularia inaequalis, a widely distributed litter ascomycete, chlorinated the aromatic rings of lignin in wood that it was degrading. In aspen wood decayed for 24 weeks, two chlorolignin fragments, 5-chlorovanillin and 2-chlorosyringaldehyde, were each found at approximately 10 mug/g of wood (dry weight). These levels resemble those of similar structures generally found in unpolluted environmental samples. Fractionation of the extractable proteins followed by tandem mass spectrometric analysis showed that the colonized wood contained a previously described C. inaequalis chloroperoxidase that very likely catalyzed lignin chlorination. Chlorolignin produced by this route and humus derived from it are probably significant components of the global chlorine cycle because chloroperoxidase-producing fungi are ubiquitous in decaying lignocellulose and lignin is the earth's most abundant aromatic substance.","pmid":"17360449","doi":"10.1073/pnas.0610074104","url":"https://pubmed.ncbi.nlm.nih.gov/17360449/"},{"id":2237,"title":"The dimensional stability of dental impression materials following immersion in disinfecting solutions.","authors":"Martin, N; Martin, M V; Jedynakiewicz, N M","year":2007,"date":"2007 Jun","journal":"Dental materials : official publication of the Academy of Dental Materials","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"OBJECTIVES: This investigation examined the effect of several disinfectant systems upon the dimensional stability of a range of common dental impression materials. A new disinfection process based upon hypochlorous acid was one of those examined (Sterilox). METHODS: Test specimens of commercially available impression materials from the following categories were investigated: alginates, addition-cured silicones, condensation-cured silicones and polyether. Three disinfection regimes were tested: sodium hypochlorite 5.25%, Perform ID and Sterilox. A custom-built automatic laser micrometer was used to measure the dimensions of sample discs of the test materials before disinfection, immediately after and then following 24h storage. Analysis of variance was employed to identify statistically significant differences within groups and across groups. RESULTS: All the disinfection routines tested resulted in acceptable levels of dimensional stability within the category of normal use of each impression material. All the materials tested can be disinfected with 10% Sterilox without undergoing unacceptable levels of dimensional change. SIGNIFICANCE: All the disinfection routines tested resulted in acceptable levels of dimensional stability within the category of normal use of each impression material.","pmid":"17353045","doi":"10.1016/j.dental.2007.01.004","url":"https://pubmed.ncbi.nlm.nih.gov/17353045/"},{"id":2240,"title":"An original route to immobilize an organic biocide onto a transparent tin dioxide electrode.","authors":"Debiemme-Chouvy, Catherine; Haskouri, Sanae; Folcher, Guy; Cachet, Hubert","year":2007,"date":"2007 Mar 27","journal":"Langmuir : the ACS journal of surfaces and colloids","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Prevention of biofilm growth on surfaces immersed in an aqueous environment could be obtained either by the release of an antifouling biocide or by the presence of such compounds on the surface. In this paper it is shown, for the first time, that an electrochemical treatment performed in the presence of chlorides and proteins allows the immobilization of an organic biocide (chloramine) on the electrode. This electrode is a stable transparent conductive tin dioxide film coated on glass. It is polarized to oxidize chloride ions into hypochlorous acid, which reacts with the organic matter (bovine serum albumin) present at the electrode/solution interface, leading on one hand to the chlorination of the proteins with in particular the chloramine formation and on the other hand to the protein aggregation on the surface.","pmid":"17311439","doi":"10.1021/la063613j","url":"https://pubmed.ncbi.nlm.nih.gov/17311439/"},{"id":2246,"title":"Chlorination by a long-lived intermediate in the mechanism of flavin-dependent halogenases.","authors":"Yeh, Ellen; Blasiak, Leah C; Koglin, Alexander; Drennan, Catherine L; Walsh, Christopher T","year":2007,"date":"2007 Feb 6","journal":"Biochemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The flavin-dependent halogenase RebH catalyzes the formation of 7-chlorotryptophan as the initial step in the biosynthesis of antitumor agent rebeccamycin. The reaction of FADH2, Cl-, and O2 in the active site generates the powerful oxidant HOCl, which was presumed to carry out the chlorination reaction. Herein, we demonstrate the formation of a long-lived chlorinating intermediate (t1/2 = 63 h at 4 degrees C) when RebH, FADH2, Cl-, and O2 react in the absence of substrate tryptophan. This intermediate remained on the enzyme after removal of FAD and transferred chlorine to tryptophan with kinetically competent rates. The identity of this intermediate is suggested by the X-ray crystal structure of RebH, which revealed an active site Lys79 located in a central position between flavin and tryptophan binding sites and just 4.1 A above C7 of tryptophan. The chlorinating species is proposed to be a Lys-epsilonNH-Cl (lysine chloramine) from reaction of enzyme-generated HOCl with the active site Lys79. This covalent enzyme chloramine likely plays a key role in directing regiospecific chlorination of substrate in this important class of biosynthetic enzymes.","pmid":"17260957","doi":"10.1021/bi0621213","url":"https://pubmed.ncbi.nlm.nih.gov/17260957/"},{"id":2247,"title":"Different experimental protocols for decontamination affect the cleaning of medical devices. A preliminary electron microscopy analysis.","authors":"Tessarolo, F; Caola, I; Fedel, M; Stacchiotti, A; Caciagli, P; Guarrera, G M; Motta, A; Nollo, G","year":2007,"date":"2007 Apr","journal":"The Journal of hospital infection","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"The aim of the present study was to examine the efficiency of different decontamination-cleaning protocols on blood-soiled catheters used for interventional cardiology. Electrophysiology and cardiac ablation disposable devices were contaminated with bacteria-spiked human blood and underwent four different pre-sterilization protocols, including a chlorine-releasing agent, a polyphenolic emulsion, and an enzymatic detergent. Treated samples were examined by optical microscopy, scanning electron microscopy and transmission electron microscopy to identify and characterize biological and inorganic residuals. The use of chlorine as a first treatment caused denaturation of serum proteins and adherence of blood components to the surface of the device, thus hindering the cleaning efficiency of subsequent treatments with enzymatic detergents. An enzymatic/chlorine protocol was more efficient, but was considered to be a greater risk to healthcare staff. Polyphenolic-based treatments had the highest level of efficiency in bioburden removal, but interaction and adsorption of this class of chemicals onto biopolymers might lead to serious concerns about toxicity on subsequent reuse. Adequate pre-sterilization cleaning is fundamental for sterilization success and high-resolution electron microscopy can provide significant and detailed information about the efficiency of chemicals used for cleaning a blood-soiled device.","pmid":"17241696","doi":"10.1016/j.jhin.2006.10.015","url":"https://pubmed.ncbi.nlm.nih.gov/17241696/"},{"id":2256,"title":"Hypochlorous acid-derived modification of phospholipids: characterization of aminophospholipids as regulatory molecules for lipid peroxidation.","authors":"Kawai, Yoshichika; Kiyokawa, Hitomi; Kimura, Yuki; Kato, Yoji; Tsuchiya, Koichiro; Terao, Junji","year":2006,"date":"2006 Nov 28","journal":"Biochemistry","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"Hypochlorous acid (HOCl), an inflammatory oxidant derived from neutrophil myeloperoxidase, can chlorinate cytosolic proteins and nuclear DNA bases of target cells by passing through the cell membrane. However, little is known about the consequences of HOCl-derived modification of cell membrane components, including phospholipids. In this study, we characterize the reaction of HOCl with phospholipid molecules and found that aminophospholipids are the key molecules that chemically regulate lipid peroxidation. Upon incubation with HOCl, the peroxidation of egg yolk phosphatidylcholine was significantly enhanced in the presence of phosphatidylethanolamine (PE). In contrast, the peroxidation was significantly inhibited in the presence of phosphatidylserine (PS). On the basis of mass spectrometric and electron paramagnetic resonance characterization, the initiator of the peroxidation was identified as the nitrogen-centered radical originating from PE-derived chloramines, especially N,N-dichlorinated PE, a major product in the HOCl-modified PE. Although PS was also chlorinated upon reaction with HOCl, the formed chloramine rapidly decomposed to phosphatidylglycolaldehyde, a novel class of lipid aldehyde. Formation of phosphatidylglycolaldehyde was also confirmed in the porcine brain PS and erythrocyte cell membrane ghost exposed to HOCl. These results provide a novel mechanism for the HOCl-induced oxidative damage and its endogenous protection in the cell membrane at the site of inflammation.","pmid":"17115715","doi":"10.1021/bi0610909","url":"https://pubmed.ncbi.nlm.nih.gov/17115715/"},{"id":2259,"title":"Amuchina 10% solution, safe antiseptic for preventing infections of exit-site of Tenckhoff catheters, in the pediatric population of a dialysis program.","authors":"Mendoza-Guevara, L; Castro-Vazquez, F; Aguilar-Kitsu, A; Morales-Nava, A; Rodriguez-Leyva, F; Sanchez-Barbosa, J L","year":2007,"date":"2007","journal":"Contributions to nephrology","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"Although, decreasing in incidence with the disconnection systems, the first complication is still peritonitis in patients with chronic renal failure and the second is infection of Tenckhoff catheter exit-site. All efforts made to diminish the frequency of exit-site infection lower the possibility of peritonitis. The pediatric population is well-known to have a major risk of infectious complications, and making easy and safe the care of the exit-site will prevent the peritonitis that follows. The aim of the study was to evaluate the efficacy of the Amuchina 10% solution vs. pH neutral soap in children with chronic renal failure, on preventing exit-site infection. There were 60 patients who were assigned randomly to one of two groups. One group used Amuchina 10% solution for the daily cleaning of the exit-site, and the other used pH neutral soap, with 14 months of follow-up. Before the study they have to be free of infection for at least 30 days. All were taught by the same nurse how to clean their exit-site. Groups were almost identical in years, sex, and time on dialysis. We had nine infections in the soap group and none in the Amuchina 10% solution group, with an OR: 17 (p = 0.004). From these nine infections, the bacteria isolated were: 4 (13%) were caused by Pseudomona aeruginosa, 1 (3.3%) by Staphylococcus aureus, coagulase-positive staphylococci in 2 (6.6%) and Serratia marcensens in 1 (3.3%). In conclusion, Amuchina 10% solution is effective in preventing infection on the exit-site, without any secondary topical reaction.","pmid":"17099309","doi":"10.1159/000096959","url":"https://pubmed.ncbi.nlm.nih.gov/17099309/"},{"id":2260,"title":"Exit-site care in peritoneal dialysis.","authors":"Wadhwa, Nand K; Reddy, Gampala H","year":2007,"date":"2007","journal":"Contributions to nephrology","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"Exit-site infection (ESI), tunnel infection and associated peritonitis are major causes of morbidity and catheter loss in chronic peritoneal dialysis patients. Meticulous exit-site care is vital in preventing ESI. Avoiding trauma to the exit-site and daily cleaning of the exit-site with a dedicated antimicrobial soap is essential for the longevity of the peritoneal dialysis catheter. Antibiotics cream and disinfectant agents including povidone-iodine, chlorhexidine, electrolytic chloroxidizing solutions (Amuchina 10% - ExSept Plus, Amuchina 5% - ExSept) are useful to keep the resident micro-organisms inhibited. ESI rates in peritoneal dialysis patients treated with Amuchina 10% (ExSept Plus) and Amuchina 5% (ExSept) for the exit-site care are similar or lower compared to povidone-iodine or chlorhexidine. Electrolytic chloroxidizing (Amuchina 10% - ExSept Plus and Amuchina 5% - ExSept) solutions for exit-site care are effective for prevention and treatment of ESI.","pmid":"17099306","doi":"10.1159/000096955","url":"https://pubmed.ncbi.nlm.nih.gov/17099306/"},{"id":2262,"title":"[Disinfection efficiency of peracetic acid, alone and in combination with hypochlorite, against Mycobacterium avium in drinking water].","authors":"Schiavano, G F; Sisti, M; De Santi, M; Brandi, G","year":2006,"date":"2006 Sep-Oct","journal":"Annali di igiene : medicina preventiva e di comunita","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Peracetic acid (PAA) is a disinfectant with a wide spectrum of antimicrobial activity, but little is known about the feasibility of using it in the field of drinking water treatment. The aim of this study has been assess disinfectant efficacy of PAA, alone or in combination with hypochlorite, against M. avium in drinking water M. avium is a common opportunistic pathogen in immunocompromised subjects that is able to survive and grow in drinking water distribution systems. In this study PAA did not show appreciable activity against the greater number of tested strains (16/21) up to 5 ppm of PAA, a weak activity was seen on 4 strains, while a significant reduction in viable cells (about 50%) was seen only on 1 strain after 48 h of treatment with 5 ppm of PAA. We also evidenced that M. avium was unaffected by chlorine concentration usually present in drinking water distribution system. Finally, the combination of PAA and sodium hypochlorite did not promote enhanced antimicrobial efficacy respect to the single disinfectants. In conclusion, our result would indicate that PAA is an unlikely candidate for the disinfection of drinking water from M. avium and further strategies are required to eliminate M. avium from drinking water system.","pmid":"17089953","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/17089953/"},{"id":2263,"title":"Modeling the reactions of superoxide and myeloperoxidase in the neutrophil phagosome: implications for microbial killing.","authors":"Winterbourn, Christine C; Hampton, Mark B; Livesey, John H; Kettle, Anthony J","year":2006,"date":"2006 Dec 29","journal":"The Journal of biological chemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Neutrophils kill bacteria by ingesting them into phagosomes where superoxide and cytoplasmic granule constituents, including myeloperoxidase, are released. Myeloperoxidase converts chloride and hydrogen peroxide to hypochlorous acid (HOCl), which is strongly microbicidal. However, the role of oxidants in killing and the species responsible are poorly understood and the subject of current debate. To assess what oxidative mechanisms are likely to operate in the narrow confines of the phagosome, we have used a kinetic model to examine the fate of superoxide and its interactions with myeloperoxidase. Known rate constants for reactions of myeloperoxidase have been used and substrate concentrations estimated from neutrophil morphology. In the model, superoxide is generated at several mm/s. Most react with myeloperoxidase, which is present at millimolar concentrations, and rapidly convert the enzyme to compound III. Compound III turnover by superoxide is essential to maintain enzyme activity. Superoxide stabilizes at approximately 25 microM and hydrogen peroxide in the low micromolar range. HOCl production is efficient if there is adequate chloride supply, but further knowledge on chloride concentrations and transport mechanisms is needed to assess whether this is the case. Low myeloperoxidase concentrations also limit HOCl production by allowing more hydrogen peroxide to escape from the phagosome. In the absence of myeloperoxidase, superoxide increases to >100 microM but hydrogen peroxide to only approximately 30 microM. Most of the HOCl reacts with released granule proteins before reaching the bacterium, and chloramine products may be effectors of its antimicrobial activity. Hydroxyl radicals should form only after all susceptible protein targets are consumed.","pmid":"17074761","doi":"10.1074/jbc.M605898200","url":"https://pubmed.ncbi.nlm.nih.gov/17074761/"},{"id":2264,"title":"Study on inactivation kinetics of hepatitis A virus and enteroviruses with peracetic acid and chlorine. New ICC/PCR method to assess disinfection effectiveness.","authors":"Bigliardi, L; Sansebastiano, G","year":2006,"date":"2006 Jun","journal":"Journal of preventive medicine and hygiene","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The virucidal activity of chlorine-compounds was studied using hepatitis A virus (HAV) and Poliovirus 2 and comparing the disinfectant efficiency of peracetic acid. HAV presented a higher resistance to HClO than Poliovirus did. With ClO2 the inactivation times of HAV were markedly shorter. A comparison between these data and those resulting from the kinetics with peracetic acid (PA) showed that PA is less effective than chlorine. As a preliminary to future research, the PCR-test integrated with cell-cultures was experimentally introduced for a quick evaluation of the HAV-infectiveness, with the aim of possible application in the field of disinfection and of viruses-isolation from environmental and food samples.","pmid":"17066904","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/17066904/"},{"id":2268,"title":"Effect of hypochloride on microbial ecology of bulking and foaming activated sludge treatment for tannery wastewater.","authors":"Ovez, Süleyman; Ors, Canan; Murat, Selda; Orhon, Derin","year":2006,"date":"2006","journal":"Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"This study investigates the effect of hypochloride application for controlling bulking and foaming on the microbial ecology of an activated sludge system treating tannery wastewater. Detailed characterization of the wastewater treatment influent and effluent is also reported for the study period. During the study, bulking and foaming are first monitored with a sudden burst in the sludge volume index over 250 mL g(-1), creating a significant deterioration of the effluent quality. The corresponding upset in the microbial ecology is the combined excessive proliferation of M. parvicella, N. limicola II and Gordona (Nocardia) spp., but mainly triggered by Gordona contamination of the floc structure and the rapid outward growth of this filamentous microorganism extending to adjacent flocs. Chlorine application at an average rate of 3 g Cl(-1)(kg MLSS.day)(-1) for 12 days provide an effective solution for bulking and foaming, restoring the effluent quality. It destroys filamentous texture between the flocs, leaving only a lot of loose and chopped filament fragments and, totally removes the Gordona spp. from solution which retrieves back into the flocs. Therefore, chlorine remediation of bulking and foaming, although temporarily effective, is only superficial as the Gordona seeding inside the floc remains intact and potentially available for excessive growth in the next favorable conditions.","pmid":"17018406","doi":"10.1080/10934520600867813","url":"https://pubmed.ncbi.nlm.nih.gov/17018406/"},{"id":2269,"title":"Characterization of the microbial flora in disinfecting footbaths with hypochlorite.","authors":"Langsrud, Solveig; Seifert, Linn; Møretrø, Trond","year":2006,"date":"2006 Sep","journal":"Journal of food protection","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"Change or disinfection of footwear are measures to prevent cross contamination between areas with low and high hygienic levels in the food industry. The efficacy of disinfecting footwear is not well documented. Samples of used disinfectant and from swabbing of corners after draining were taken from disinfecting footbaths containing chlorine in four Norwegian cheese factories. Bacteria were present in 9 of 12 footbaths and more positive samples were found from swab samples than from used disinfectant. The microbial flora in footbaths varied between the dairies. In two dairies, the flora was dominated by Pseudomonas spp. and Acinetobacter spp., respectively. In the third dairy, both Bacillus spp. and Staphylococcus spp. were present and in the fourth dairy, the flora was diverse (Acinetobacter sp., Enterococcus faecalis, Klebsiella pneumoniae, and Bacillus sp.). The strains were not resistant to the recommended user concentration of chlorine in bactericidal suspension or surface tests. The degree of attachment to plastic varied between strains and species and bacteria attached to surfaces were in general more resistant than suspended bacteria. The results of the survey indicated that disinfecting footbaths containing chlorine may act as contamination sources in food factories and should not be used without regular hygienic monitoring.","pmid":"16995523","doi":"10.4315/0362-028x-69.9.2193","url":"https://pubmed.ncbi.nlm.nih.gov/16995523/"},{"id":2272,"title":"CFTR Expression in human neutrophils and the phagolysosomal chlorination defect in cystic fibrosis.","authors":"Painter, Richard G; Valentine, Vincent G; Lanson, Nicholas A Jr; Leidal, Kevin; Zhang, Qiang; Lombard, Gisele; Thompson, Connie; Viswanathan, Anand; Nauseef, William M; Wang, Guangdi; Wang, Guoshun","year":2006,"date":"2006 Aug 29","journal":"Biochemistry","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Production of hypochlorous acid (HOCl) in neutrophils, a critical oxidant involved in bacterial killing, requires chloride anions. Because the primary defect of cystic fibrosis (CF) is the loss of chloride transport function of the CF transmembrane conductance regulator (CFTR), we hypothesized that CF neutrophils may be deficient in chlorination of bacterial components due to a limited chloride supply to the phagolysosomal compartment. Multiple approaches, including RT-PCR, immunofluorescence staining, and immunoblotting, were used to demonstrate that CFTR is expressed in resting neutrophils at the mRNA and protein levels. Probing fractions of resting neutrophils isolated by Percoll gradient fractionation and free flow electrophoresis for CFTR revealed its presence exclusively in secretory vesicles. The CFTR chloride channel was also detected in phagolysosomes, a special organelle formed after phagocytosis. Interestingly, HL-60 cells, a human promyelocytic leukemia cell line, upregulated CFTR expresssion when induced to differentiate into neutrophils with DMSO, strongly suggesting its potential role in mature neutrophil function. Analyses by gas chromatography and mass spectrometry (GC-MS) revealed that neutrophils from CF patients had a defect in their ability to chlorinate bacterial proteins from Pseudomonas aeruginosa metabolically prelabeled with [(13)C]-l-tyrosine, unveiling defective intraphagolysosomal HOCl production. In contrast, both normal and CF neutrophils exhibited normal extracellular production of HOCl when stimulated with phorbol ester, indicating that CF neutrophils had the normal ability to produce this oxidant in the extracellular medium. This report provides evidence which suggests that CFTR channel expression in neutrophils and its dysfunction affect neutrophil chlorination of phagocytosed bacteria.","pmid":"16922501","doi":"10.1021/bi060490t","url":"https://pubmed.ncbi.nlm.nih.gov/16922501/"},{"id":2273,"title":"Arthritogenicity of collagen type II is increased by chlorination.","authors":"Westman, E; Lundberg, K; Erlandsson Harris, H","year":2006,"date":"2006 Aug","journal":"Clinical and experimental immunology","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"During inflammation, activated neutrophils, monocytes and macrophages produce and release myeloperoxidase (MPO). MPO converts hydrogen peroxide to hypochlorous acid, a highly reactive and oxidizing agent. Proteins subjected to hypochlorous acid become chlorinated. We analysed how chlorination of the cartilage antigen collagen type II (CII) affects its immunogenic and arthritogenic properties by studying immune responses to chlorinated CII in comparison to immune responses to CII and by studying the development of arthritis in rats immunized with CII-Cl. CII-Cl immunization of LEW.1AV1 rats caused a 100% incidence of arthritis with a mean maximum score of 9.2 (maximal score possible 16). The same dose of non-chlorinated CII did not induce arthritis at all. Rats immunized with CII-Cl developed high anti-CII-Cl IgG titres and also developed IgG antibodies recognizing the non-chlorinated form of CII. Analysis of cytokine mRNA expression in lymph nodes 10 days after immunzation revealed an increased expression of interferon (IFN)-gamma mRNA and interleukin (IL)-1beta mRNA in CII-Cl-immunized rats compared to CII-immunized rats. Thus, chlorination of CII increased its immunogenicity as well as its arthritogenicity. As neutrophils, monocytes and macrophages are abundant cells in arthritic joints of patients with rheumatoid arthritis, chlorination might be a mechanism by which immunoreactivity to CII is induced and by which chronic joint inflammation is supported.","pmid":"16879255","doi":"10.1111/j.1365-2249.2006.03129.x","url":"https://pubmed.ncbi.nlm.nih.gov/16879255/"},{"id":2274,"title":"Modified low-density lipoproteins and high-density lipoproteins. From investigation tools to real in vivo players.","authors":"Koller, Elisabeth; Volf, Ivo; Gurvitz, Aner; Koller, Franz","year":2006,"date":"2006","journal":"Pathophysiology of haemostasis and thrombosis","category":"Food & agriculture","evidence":"Review","relevance":"High","abstract":"It has long been known that the oxidative state of the various plasma lipoproteins modulates platelet aggregability, thereby contributing to atherogenesis. Low-density lipoprotein (LDL), occurring in vivo both in the native and oxidised forms, interacts directly with platelets, by binding to specific receptors. While the identity of the receptors for native LDL and some subfractions of high-density lipoproteins (HDL) remains disputed, apoE-containing HDL(2) binds to LRP8. The nature of these interactions as well as the distinction between candidate receptor proteins was elucidated using covalently modified apolipoproteins, which pointed to the participation of apolipoproteins in high affinity binding. However, the platelet effects initiated by binding of native lipoproteins remain controversial. Some of this ambiguity can be traced to the fact that native LDL inevitably undergoes substantial oxidisation upon modification, including by radiolabelling. The platelet-activating effects provoked by oxidised LDL are irrefutable, but many details remain unknown. The role of CD36 in platelet binding by oxidised LDL is well established, although additional receptors may exist. Much less is known about the interaction of oxidised HDL with platelets, since platelet activation was observed in some, but not all studies. Various frequently applied in vitro oxidation methods produce modified lipoprotein species that may not be relevant in vivo. Based on the reported modifications obtained by in vitro oxidation of LDL, early investigations focused mainly on the formation and the eventual effects of oxidised lipids. More recently, alterations to lipoproteins performed using hypochloric acid and myeloperoxidase redirected the attention to the role of modified apoproteins in triggering platelet responses.","pmid":"16877881","doi":"10.1159/000093225","url":"https://pubmed.ncbi.nlm.nih.gov/16877881/"},{"id":2275,"title":"[Comparison on the in vitro hatching methods for Taenia solium eggs].","authors":"Zhao, Yan-bing","year":2006,"date":"2006 Feb 28","journal":"Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Sodium hypochlorite digestion (NaClo) method and enzyme method were compared in the hatching of Taenia solium eggs. Both methods are effective, but the sodium hypochlorite digestion shows higher hatching rate (96.4%) and viability (89.0%) in a shorter reaction time (< 5 min) without needing expensive reagents.","pmid":"16866155","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/16866155/"},{"id":2283,"title":"Surface detail, compressive strength, and dimensional accuracy of gypsum casts after repeated immersion in hypochlorite solution.","authors":"Abdullah, Mohammed Aleem","year":2006,"date":"2006 Jun","journal":"The Journal of prosthetic dentistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"STATEMENT OF PROBLEM: One method used to disinfect a dental cast is immersion in a disinfecting solution. Repeated immersion of a cast in disinfectant may affect surface detail as well as other physical properties. PURPOSE: The purpose of this study was to evaluate the changes in surface detail quality, dimensional accuracy, and wet compressive strength of dental casts as a result of repeated disinfection in slurry containing 0.525% sodium hypochlorite solution. MATERIAL AND METHODS: Two different test specimen configurations were used, one for evaluating surface detail quality and dimensional accuracy and the other for compressive strength. Sixty specimens each were made of type III and type IV dental stone (Excalibur). Thirty specimens were immersed in slurry, a supernatant solution of calcium sulfate in distilled water (control casts), and 30 in slurry with sodium hypochlorite (test casts) solutions for 30 minutes and air dried for 24 hours. This process was repeated 7 times before testing. Linear dimensional change, surface detail quality, and wet compressive strength were determined according to American National Standards Institute/American Dental Association (ANSI/ADA) standards. The data were analyzed using 2-way analysis of variance and 2-sample independent t tests (alpha=.05). RESULTS: For specimens prepared with type III and type IV stone, treatment by immersion in slurry (control casts) and in slurry with sodium hypochlorite (test casts) resulted in an increase (P<.0001) in linear dimensional change. The type IV casts treated with slurry with sodium hypochlorite showed significantly less (P<.0001) mean linear dimensional change (0.025%) compared with type III stone casts (0.063%), and the values remained within the ANSI/ADA specified standards. Both test solutions caused some degree of erosion or damage to the surface quality of casts made from type III and type IV stones. However, the difference between the control and test casts was not significant. Slurry with 0.525% sodium hypochlorite solution decreased the compressive strength of both types of stones significantly (P<.001) compared with distilled water slurry. However, the values remained close to ANSI/ADA standards. CONCLUSION: The results demonstrated that repeated immersion of type III and type IV stone specimens in slurry with distilled water and slurry with 0.525% sodium hypochlorite, along with drying in air, caused a significant increase in linear dimension and a significant decrease in wet compressive strength. Although both the solutions caused some degree of damage to surface details for type III and type IV stones, the difference was not significant.","pmid":"16765160","doi":"10.1016/j.prosdent.2006.03.019","url":"https://pubmed.ncbi.nlm.nih.gov/16765160/"},{"id":2286,"title":"Evidence that monochloramine disinfectant could lead to elevated Pb levels in drinking water.","authors":"Switzer, Jay A; Rajasekharan, Vishnu V; Boonsalee, Sansanee; Kulp, Elizabeth A; Bohannan, Eric W","year":2006,"date":"2006 May 15","journal":"Environmental science & technology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Many water districts have recently shifted from free chlorine (in the form of HOCl/OCl-) to monochloramine (NH2-Cl) as a disinfectant for drinking water to lower the concentration of chlorinated hydrocarbon byproducts in the water. There is concern that the use of NH2Cl disinfectant may lead to higher Pb levels in drinking water. In this study, the electrochemical quartz crystal microbalance is used to compare the effects of these two disinfectants on the dissolution of Pb films. A 0.5 microm thick Pb film nearly completely dissolves in a NH2Cl solution, but it is passivated in a HOCl/OCl- solution. X-ray diffraction analysis shows that the NH2Cl oxidizes Pb to Pb(II) species such as Pb3-(OH)2(CO3)2, whereas the stronger oxidant, HOCl/OCl-, oxidizes Pb to Pb(IV) as an insoluble PbO2 conversion coating. Although NH2Cl may produce less halogenated organic byproducts than HOCl/OCl- when used as a disinfectant, it may lead to increased Pb levels in drinking water.","pmid":"16749710","doi":"10.1021/es052411r","url":"https://pubmed.ncbi.nlm.nih.gov/16749710/"},{"id":2287,"title":"Redox-sensitive impairment of porcine coronary artery vasodilation by hypochlorite-modified LDL.","authors":"Plass, Christian A; Schmid, Werner; Holy, Erik W; Kreatschitsch, Ursula; Laggner, Hildegard; Volf, Ivo","year":2007,"date":"2007 Feb","journal":"Atherosclerosis","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Atherosclerotic vascular disease is associated with abnormal vasomotor function and oxidized low density lipoproteins (OxLDL) are believed to play a keyrole therein. Several compounds emerging from LDL lipid peroxidation have been shown to be able to alter vasomotion but the role of oxidized apoB in this process is not fully understood. Myeloperoxidase has been identified in atherosclerotic lesions and hypochlorite produced by this enzyme represents a strong oxidant. LDL oxidation by hypochlorite differs from most other forms of LDL oxidation in that hypochlorite-mediated oxidation shows a predilection for the protein moiety of LDL and does not result in lipid peroxidation. In this work, we use porcine coronary artery segments and show that hypochlorite-oxidized LDL (hyp-OxLDL) are able to impair dilatation induced by substance P in a dose- and modification-dependent way. Treatment of hyp-OxLDL with methionine resulted in quantitative elimination of reactive chloramines in LDL and complete recovery of relaxation. As application of the scavenger receptor antagonist maleylated albumin strongly interferes with the effects of hyp-OxLDL on vasomotion, we conclude that specific binding of hypochlorite-modified apoB is likely to be involved in mediating the observed effects.","pmid":"16730731","doi":"10.1016/j.atherosclerosis.2006.04.001","url":"https://pubmed.ncbi.nlm.nih.gov/16730731/"},{"id":2289,"title":"L-arginine chlorination results in the formation of a nonselective nitric-oxide synthase inhibitor.","authors":"Yang, Jian; Ji, Ruirui; Cheng, Yunhui; Sun, Ju-Zhong; Jennings, Lisa K; Zhang, Chunxiang","year":2006,"date":"2006 Sep","journal":"The Journal of pharmacology and experimental therapeutics","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Reduced nitric oxide (NO) bioavailability and impaired vascular function are the key pathological characteristics of inflammatory diseases such as atherosclerosis. We have recently found that leukocyte-derived hypochlorous acid is able to react with the nitric-oxide synthase (NOS) substrate L-arginine to produce chlorinated L-arginine (cl-L-Arg). Interestingly, cl-L-Arg potently inhibits the formation of NO metabolites in cultured endothelial cells. It is unknown whether cl-L-Arg has a direct inhibitory effect on endothelial NOS (eNOS). In addition, the effect of cl-L-Arg on the other NOS isoforms, neuronal NOS (nNOS) and inducible NOS (iNOS), is also unknown. Therefore, we designed the current study to test the effects of cl-L-Arg on eNOS, nNOS, and iNOS. Using recombinant NOS, we found that cl-L-Arg had a direct inhibitory effect on the activity of NOS. The effect of cl-L-Arg on NOS activity is nonselective, as all three NOS isoforms were inhibited with a similar IC(50). We further determined the effect of cl-L-Arg on the three NOS isoforms at the tissue level. The results demonstrated that cl-L-Arg potently inhibited all three NOS isoform-mediated vessel reactivities, as well as the NOS signaling molecule cGMP. Cl-L-Arg might serve as a novel endogenous NOS inhibitor and an important mediator for vascular dysfunction under inflammatory conditions such as atherosclerosis. Blocking cl-L-Arg formation may be a new therapeutic approach to cardiovascular diseases.","pmid":"16717106","doi":"10.1124/jpet.106.104422","url":"https://pubmed.ncbi.nlm.nih.gov/16717106/"},{"id":2290,"title":"Effects of biological oxidants on the catalytic activity and structure of group VIA phospholipase A2.","authors":"Song, Haowei; Bao, Shunzhong; Ramanadham, Sasanka; Turk, John","year":2006,"date":"2006 May 23","journal":"Biochemistry","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Group VIA phospholipase A(2) (iPLA(2)beta) is expressed in phagocytes, vascular cells, pancreatic islet beta-cells, neurons, and other cells and plays roles in transcriptional regulation, cell proliferation, apoptosis, secretion, and other events. A bromoenol lactone (BEL) suicide substrate used to study iPLA(2)beta functions inactivates iPLA(2)beta by alkylating Cys thiols. Because thiol redox reactions are important in signaling and some cells that express iPLA(2)beta produce biological oxidants, iPLA(2)beta might be subject to redox regulation. We report that biological concentrations of H(2)O(2), NO, and HOCl inactivate iPLA(2)beta, and this can be partially reversed by dithiothreitol (DTT). Oxidant-treated iPLA(2)beta modifications were studied by LC-MS/MS analyses of tryptic digests and included DTT-reversible events, e.g., formation of disulfide bonds and sulfenic acids, and others not so reversed, e.g., formation of sulfonic acids, Trp oxides, and Met sulfoxides. W(460) oxidation could cause irreversible inactivation because it is near the lipase consensus sequence ((463)GTSTG(467)), and site-directed mutagenesis of W(460) yields active mutant enzymes that exhibit no DTT-irreversible oxidative inactivation. Cys651-sulfenic acid formation could be one DTT-reversible inactivation event because Cys651 modification correlates closely with activity loss and its mutagenesis reduces sensitivity to inhibition. Intermolecular disulfide bond formation might also cause reversible inactivation because oxidant-treated iPLA(2)beta contains DTT-reducible oligomers, and oligomerization occurs with time- and temperature-dependent iPLA(2)beta inactivation that is attenuated by DTT or ATP. Subjecting insulinoma cells to oxidative stress induces iPLA(2)beta oligomerization, loss of activity, and subcellular redistribution and reduces the rate of release of arachidonate from phospholipids. These findings raise the possibility that redox reactions affect iPLA(2)beta functions.","pmid":"16700550","doi":"10.1021/bi060502a","url":"https://pubmed.ncbi.nlm.nih.gov/16700550/"},{"id":2294,"title":"Inactivation of biological agents using neutral oxone-chloride solutions.","authors":"Delcomyn, Carrie A; Bushway, Karen E; Henley, Michael V","year":2006,"date":"2006 Apr 15","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Bleach solutions containing the active ingredient hypochlorite (OCl-) serve as powerful biological disinfectants but are highly caustic and present a significant compatibility issue when applied to contaminated equipment or terrain. A neutral, bicarbonate-buffered aqueous solution of Oxone (2K2HSO5.KHSO4.K2SO4) and sodium chloride that rapidly generates hypochlorite and hypochlorous acid (HOCl) in situ was evaluated as a new alternative to bleach for the inactivation of biological agents. The solution produced a free chlorine (HOCl + OCl-) concentration of 3.3 g/L and achieved > or =5.8-log inactivation of spores of Bacillus atrophaeus, Bacillus thuringiensis, Aspergillus niger, and Escherichia coli vegetative cells in 1 min at 22 degrees C. Seawaterwas an effective substitute for solid sodium chloride and inactivated 5 to 8 logs of each organism in 10 min over temperatures ranging from -5 degrees C to 55 degrees C. Sporicidal effectiveness increased as free chlorine concentrations shifted from OCl- to HOCl. Neutrally buffered Oxone-chloride and Oxone-seawater solutions are mitigation alternatives for biologically contaminated equipment and environments that would otherwise be decontaminated using caustic bleach solutions.","pmid":"16683620","doi":"10.1021/es052146+","url":"https://pubmed.ncbi.nlm.nih.gov/16683620/"},{"id":2295,"title":"Triclosan reactivity in chloraminated waters.","authors":"Greyshock, Aimee E; Vikesland, Peter J","year":2006,"date":"2006 Apr 15","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Triclosan, widely employed as an antimicrobial additive in many household personal care products, has recently been detected in wastewater treatment plant effluents and in source waters used for drinking water supplies. Chloramines used either as alternative disinfectants in drinking water treatment or formed during chlorination of nonnitrified wastewater effluents have the potential to react with triclosan. This study examined triclosan reactivity in chloraminated waters over the pH range of 6.5-10.5. Experimental and modeling results show that monochloramine directly reacts with the phenolate form of triclosan; however, the reaction is relatively slow as evinced by the second-order rate constant k(ArO)-NH2Cl = 0.025 M(-1) s(-1). Kinetic modeling indicates that for pH values less than 9.5, reactions between triclosan and two monochloramine autodecomposition intermediates, hypochlorous acid (k(ArO)-HOC = 5.4 x 10(3) M(-1) s(-1)) and dichloramine (k(ArO)-NHCl2 = 60 M(-1) s(-1)), are responsible for a significant percentage of the observed triclosan decay. The products of these reactions include three chlorinated triclosan byproducts as well as 2,4-dichlorophenol and 2,4,6-trichlorophenol. Low levels of chloroform were detected after 1 week at pH values of 6.5 and 7.5. The slow reactivity of triclosan in the presence of chloramines explains the recalcitrance of this species in nonnitrified wastewater effluents.","pmid":"16683600","doi":"10.1021/es051952d","url":"https://pubmed.ncbi.nlm.nih.gov/16683600/"},{"id":2296,"title":"Paullinia pinnata extracts rich in polyphenols promote vascular relaxation via endothelium-dependent mechanisms.","authors":"Zamble, Alexis; Carpentier, Marie; Kandoussi, Abdelmejid; Sahpaz, Sevser; Petrault, Olivier; Ouk, Tawarak; Hennuyer, Nathalie; Fruchart, Jean-Charles; Staels, Bart; Bordet, Régis; Duriez, Patrick; Bailleul, François; Martin-Nizard, Françoise","year":2006,"date":"2006 Apr","journal":"Journal of cardiovascular pharmacology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Paullinia pinnata L. (Sapindaceae) is an African tropical plant whose roots and leaves are used in traditional medicine for many purposes, especially for erectile dysfunction, but its action mechanism is unknown. P. pinnata root and leaf methanolic extracts are rich in phenolic compounds. This study shows that both extracts are highly antioxidative and induce a slight transcriptional activity of peroxisome proliferator activated receptor-alpha. They also increased and decreased endothelial nitric oxide synthase and endothelin-1 mRNA levels in bovine aortic endothelial cells, respectively. In this study P. pinnata methanolic extracts in cumulative doses elicited in a dose-dependent manner the relaxation of phenylephrine precontracted isolated rat aortic rings. N-nitro-L-arginine methyl ester significantly attenuated the capacity of both extracts to induce arterial relaxation, indicating that this arterial relaxation was mediated by endothelial nitric oxide release. It could be suggested that the arterial relaxation induced by both extracts could be mainly linked to their capacities to inhibit nitric oxide oxidation through their antioxidant properties.","pmid":"16680075","doi":"10.1097/01.fjc.0000211734.53798.1d","url":"https://pubmed.ncbi.nlm.nih.gov/16680075/"},{"id":2297,"title":"Evaluation of hypochlorous acid washes in the treatment of chronic venous leg ulcers.","authors":"Selkon, J B; Cherry, G W; Wilson, J M; Hughes, M A","year":2006,"date":"2006 Jan","journal":"Journal of wound care","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"OBJECTIVE: Hypochlorous acid (HOCl) is a highly microbiocidal agent active against bacteria, viruses and fungi. Using quantitative microbiology, preliminary studies showed it achieved an appreciable reduction in the bacterial burden in chronic venous leg ulcers. The study aimed to determine whether it has a role as an additional treatment for chronic venous ulcers that have not healed with conventional treatment. METHOD: On the basis of previous reports we designed a study in which patients acted as their own controls, in that only patients who failed to achieve a 44% reduction in wound size with standard treatment (compression bandaging) received HOCl washes. RESULTS: Of 30 patients admitted to the study, 10 achieved a 44% ulcer reduction after three weeks of standard treatment. In addition to the standard compression treatment, the remaining 20 patients were given HOCl washes over 12 weeks. Of the 20 ulcers, nine (45%) healed and five (25%) reduced in size by over 60%. All patients became free of pain. CONCLUSION: These findings confirm the clinical efficacy of treating venous leg ulcers with hypochlorous washes. Use of HOCl washes as an adjunctive therapy for recalcitrant venous leg ulcers appreciably increases healing and rapidly relieves pain.","pmid":"16669304","doi":"10.12968/jowc.2006.15.1.26861","url":"https://pubmed.ncbi.nlm.nih.gov/16669304/"},{"id":2298,"title":"Captopril inhibits the oxidative modification of apolipoprotein B-100 caused by myeloperoxydase in a comparative in vitro assay of angiotensin converting enzyme inhibitors.","authors":"Van Antwerpen, Pierre; Legssyer, Ilham; Zouaoui Boudjeltia, Karim; Babar, Sajida; Moreau, Patrick; Moguilevsky, Nicole; Vanhaeverbeek, Michel; Ducobu, Jean; Nève, Jean","year":2006,"date":"2006 May 10","journal":"European journal of pharmacology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The oxidative modification of low-density lipoproteins (LDL) is a key event in the formation of atheromatous lesions. Indeed, oxidized derivatives accumulate in the vascular wall and promote a local inflammatory process which triggers the progression of the atheromatous plaque. Myeloperoxidase (MPO) has been mentioned as a major contributor to this oxidative process. It takes part in the oxidation both of lipids by chlorination and peroxidation and of apolipoprotein B-100. Based on recent observations with several anti-inflammatory and thiol-containing drugs, the present study was designed to test the hypothesis that anti-hypertensive agents from the angiotensin converting enzyme (ACE) inhibitors group inhibit the oxidative modifications of Apo B-100 caused by MPO. Captopril, ramipril, enalapril, lisinopril and fosinopril were assessed by measuring: their inhibiting effect on the MPO/H(2)O(2)/Cl(-) system, the accumulation of compound II, which reflects the inhibition of the synthesis of HOCl and the LDL oxidation by MPO in presence of several concentrations of ACE inhibitors. Only captopril, a thiol-containing ACE inhibitor, was able to significantly decrease the oxidative modification of LDL in a dose dependent manner and this by scavenging HOCl. This efficient anti-hypertensive drug therefore appears to also protect against the atherosclerotic process by this newly documented mechanism.","pmid":"16631159","doi":"10.1016/j.ejphar.2006.03.022","url":"https://pubmed.ncbi.nlm.nih.gov/16631159/"},{"id":2299,"title":"A perspective on the environmental risk of halogenated by-products from uses of hypochlorite using a whole effluent toxicity based approach.","authors":"Johnson, Ian; Pickup, John A; van Wijk, Dolf","year":2006,"date":"2006 Apr","journal":"Environmental toxicology and chemistry","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"An assessment has been made of the potential for toxic effects to aquatic life that may arise from halogenated organic by-products formed by reaction of hypochlorite with organic matter in various use scenarios as a contribution to the risk assessment of sodium hypochlorite under the European Union Existing Chemicals legislation. In the study, samples that would represent worst-case models for effluents containing halogenated by-products from a range of uses of hypochlorite were prepared by chlorinating and then dechlorinating (removing residual chlorine) raw settled sewage (C/D-RSS). This sample was then compared to raw settled sewage that had not been treated (RSS) to assess whether halogenated by-products formed in the chlorination process were toxic or bioaccumulable and persistent. The relative toxicity of the samples was assessed using a series of tests with representatives of different taxonomic groups (bacteria, algae, and invertebrates). The persistence and potential for bioaccumulation of chlorinated by-products was assessed by exposing solid-phase microextraction fibers to samples of RSS and C/D-RSS before and after degradation in a Zahn-Wellens test. For all the taxa tested in the study, the mixture of by-products formed in the C/D-RSS sample did not increase toxicity relative to that measured in the RSS sample. Chlorination of the raw settled sewage did produce additional potentially bioaccumulable halogenated substances compared to the raw settled sewage. However, after degradation, the amount of potentially bioaccumulable halogenated substances in the RSS and C/D-RSS samples was comparable, indicating that these substances were degradable. The results are discussed in the context of the overall risk assessment for sodium hypochlorite.","pmid":"16629158","doi":"10.1897/05-195r.1","url":"https://pubmed.ncbi.nlm.nih.gov/16629158/"},{"id":2313,"title":"Reactive oxygen species inactivation of surfactant involves structural and functional alterations to surfactant proteins SP-B and SP-C.","authors":"Rodríguez-Capote, Karina; Manzanares, Dahis; Haines, Thomas; Possmayer, Fred","year":2006,"date":"2006 Apr 15","journal":"Biophysical journal","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Exposing bovine lipid extract surfactant (BLES), a clinical surfactant, to reactive oxygen species arising from hypochlorous acid or the Fenton reaction resulted in an increase in lipid (conjugated dienes, lipid aldehydes) and protein (carbonyls) oxidation products and a reduction in surface activity. Experiments where oxidized phospholipids (PL) were mixed with BLES demonstrated that this addition hampered BLES biophysical activity. However the effects were only moderately greater than with control PL. These results imply a critical role for protein oxidation. BLES oxidation by either method resulted in alterations in surfactant proteins SP-B and SP-C, as evidenced by altered Coomassie blue and silver staining. Western blot analyses showed depressed reactivity with specific antibodies. Oxidized SP-C showed decreased palmitoylation. Reconstitution experiments employing PL, SP-B, and SP-C isolated from control or oxidized BLES demonstrated that protein oxidation was more deleterious than lipid oxidation. Furthermore, addition of control SP-B can improve samples containing oxidized SP-C, but not vice versa. We conclude that surfactant oxidation arising from reactive oxygen species generated by air pollution or leukocytes interferes with surfactant function through oxidation of surfactant PL and proteins, but that protein oxidation, in particular SP-B modification, produces the major deleterious effects.","pmid":"16443649","doi":"10.1529/biophysj.105.073106","url":"https://pubmed.ncbi.nlm.nih.gov/16443649/"},{"id":2325,"title":"A sensitive and selective assay for chloramine production by myeloperoxidase.","authors":"Dypbukt, Jeannette M; Bishop, Cynthia; Brooks, Wendy M; Thong, Bob; Eriksson, Håkan; Kettle, Anthony J","year":2005,"date":"2005 Dec 1","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"We describe a new assay for the chlorination activity of myeloperoxidase and detection of chloramines. Chloramines were detected by using iodide to catalyze the oxidation of either 3,3',5,5'-tetramethylbenzidine (TMB) or dihydrorhodamine to form strongly absorbing or fluorescent products, respectively. With TMB as little as 1 muM taurine chloramine could be detected. The sensitivity of the dihydrorhodamine assay was about 10-fold greater. The chlorination activity of myeloperoxidase was measured by trapping hypochlorous acid with taurine and subsequently using iodide to promote the oxidation reactions of the accumulated taurine chloramine. A similar approach was used to detect hypochlorous acid production by stimulated human neutrophils. Iodide-dependent catalysis distinguished N-chloramines from N-bromamines. This allows for discrimination between heme peroxidases that generate either hypochlorous acid or hypobromous acid. The assay has distinct advantages over existing assays for myeloperoxidase with regard to sensitivity, specificity, and its ease and versatility of use.","pmid":"16274882","doi":"10.1016/j.freeradbiomed.2005.07.008","url":"https://pubmed.ncbi.nlm.nih.gov/16274882/"},{"id":2326,"title":"Generation of free radicals during decomposition of hydroperoxide in the presence of myeloperoxidase or activated neutrophils.","authors":"Panasenko, O M; Chekanov, A V; Arnhold, J; Sergienko, V I; Osipov, A N; Vladimirov, Yu A","year":2005,"date":"2005 Sep","journal":"Biochemistry. Biokhimiia","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"It was shown with the spin trap alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone that myeloperoxidase (MPO) in the presence of its substrates H2O2 and Cl- as well as activated neutrophils destroy tert-butyl hydroperoxide producing two adducts of O-centered radicals which were identified as peroxyl and alcoxyl radicals. Inhibitory analysis performed with traps of hypochlorite (taurine and methionine), free radical scavengers (2,6-di-tret-butyl-4-methylphenol and mannitol), and MPO inhibitors (salicylhydroxamic acid and 4-aminobenzoic acid hydrazide) revealed that the destruction of the hydroperoxide group in the presence of isolated MPO or activated neutrophils was directly caused by the activity of MPO: some radical intermediates appeared as a result of the chlorination cycle of MPO at the stage of hypochlorite generation, whereas the other radicals were produced independently of hypochlorite, presumably with involvement of the peroxidase cycle of MPO. The data suggest that the activated neutrophils located in the inflammatory foci and secreting MPO into the extracellular space can convert hydroperoxides into free radicals initiating lipid peroxidation and other free radical reactions and, thus, promoting destruction of protein-lipid complexes (biological membranes, blood lipoproteins, etc.).","pmid":"16266270","doi":"10.1007/s10541-005-0215-z","url":"https://pubmed.ncbi.nlm.nih.gov/16266270/"},{"id":2334,"title":"Tryptophan 7-halogenase (PrnA) structure suggests a mechanism for regioselective chlorination.","authors":"Dong, Changjiang; Flecks, Silvana; Unversucht, Susanne; Haupt, Caroline; van Pée, Karl-Heinz; Naismith, James H","year":2005,"date":"2005 Sep 30","journal":"Science (New York, N.Y.)","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Chlorinated natural products include vancomycin and cryptophycin A. Their biosynthesis involves regioselective chlorination by flavin-dependent halogenases. We report the structural characterization of tryptophan 7-halogenase (PrnA), which regioselectively chlorinates tryptophan. Tryptophan and flavin adenine dinucleotide (FAD) are separated by a 10 angstrom-long tunnel and bound by distinct enzyme modules. The FAD module is conserved in halogenases and is related to flavin-dependent monooxygenases. On the basis of biochemical studies, crystal structures, and by analogy with monooxygenases, we predict that FADH2 reacts with O2 to make peroxyflavin, which is decomposed by Cl-. The resulting HOCl is guided through the tunnel to tryptophan, where it is activated to participate in electrophilic aromatic substitution.","pmid":"16195462","doi":"10.1126/science.1116510","url":"https://pubmed.ncbi.nlm.nih.gov/16195462/"},{"id":2336,"title":"Superoxide-dependent oxidation of melatonin by myeloperoxidase.","authors":"Ximenes, Valdecir F; Silva, Sueli de O; Rodrigues, Maria R; Catalani, Luiz H; Maghzal, Ghassan J; Kettle, Anthony J; Campa, Ana","year":2005,"date":"2005 Nov 18","journal":"The Journal of biological chemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase uses hydrogen peroxide to oxidize numerous substrates to hypohalous acids or reactive free radicals. Here we show that neutrophils oxidize melatonin to N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK) in a reaction that is catalyzed by myeloperoxidase. Production of AFMK was highly dependent on superoxide but not hydrogen peroxide. It did not require hypochlorous acid, singlet oxygen, or hydroxyl radical. Purified myeloperoxidase and a superoxide-generating system oxidized melatonin to AFMK and a dimer. The dimer would result from coupling of melatonin radicals. Oxidation of melatonin was partially inhibited by catalase or superoxide dismutase. Formation of AFMK was almost completely eliminated by superoxide dismutase but weakly inhibited by catalase. In contrast, production of melatonin dimer was enhanced by superoxide dismutase and blocked by catalase. We propose that myeloperoxidase uses superoxide to oxidize melatonin by two distinct pathways. One pathway involves the classical peroxidation mechanism in which hydrogen peroxide is used to oxidize melatonin to radicals. Superoxide adds to these radicals to form an unstable peroxide that decays to AFMK. In the other pathway, myeloperoxidase uses superoxide to insert dioxygen into melatonin to form AFMK. This novel activity expands the types of oxidative reactions myeloperoxidase can catalyze. It should be relevant to the way neutrophils use superoxide to kill bacteria and how they metabolize xenobiotics.","pmid":"16148002","doi":"10.1074/jbc.M506384200","url":"https://pubmed.ncbi.nlm.nih.gov/16148002/"},{"id":2339,"title":"Bromination and chlorination reactions of myeloperoxidase at physiological concentrations of bromide and chloride.","authors":"Senthilmohan, Revathy; Kettle, Anthony J","year":2006,"date":"2006 Jan 15","journal":"Archives of biochemistry and biophysics","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase and eosinophil peroxidase use hydrogen peroxide to oxidize halides and thiocyanate to their respective hypohalous acids. Myeloperoxidase produces mainly hypochlorous acid and hypothiocyanite. Hypobromous acid and hypothiocyanite are the major products of eosinophil peroxidase. We have investigated the ability of myeloperoxidase to produce hypobromous acid in the presence of physiological concentrations of chloride and bromide. In accord with previous studies, between pH 5 and 7, myeloperoxidase converted about 90% of available hydrogen peroxide to hypochlorous acid and the remainder to hypobromous acid. Above pH 7, there was an abrupt rise in the yield of hypobromous acid. At pH 7.8, it accounted for 40% of the hydrogen peroxide. Bromide, at physiological concentrations, promoted a dramatic increase in bromination of human serum albumin catalyzed by myeloperoxidase. The level of 3-bromotyrosine increased to 16-fold greater than that for 3-chlorotyrosine. Chlorination of tyrosyl residues was not affected by bromide. With reagent hypohalous acids, bromination of tyrosyl residues was considerably more facile than chlorination. Hypochlorous acid promoted bromination to only a limited extent, which ruled out transhalogenation as a substantive route to 3-bromotyrosine. Chloramines and bromamines were also formed on albumin. Bromamines decayed much faster than chloramines and rapidly gave rise to protein carbonyls. We conclude that at physiological concentrations of chloride and bromide, hypobromous acid can be a major oxidant produced by myeloperoxidase. Its production in vivo will depend on pH and the concentration of bromide. Once produced, hypobromous acid will react with proteins to form bromamines, carbonyls, and brominated tyrosine residues. Consequently, 3-bromotyrosine should be considered as an oxidative product of myeloperoxidase and cannot be used as a specific biomarker for eosinophil peroxidase.","pmid":"16125131","doi":"10.1016/j.abb.2005.07.005","url":"https://pubmed.ncbi.nlm.nih.gov/16125131/"},{"id":2340,"title":"Inactivation of Escherichia coli O157:H7 in biofilm on stainless steel by treatment with an alkaline cleaner and a bacteriophage.","authors":"Sharma, M; Ryu, J-H; Beuchat, L R","year":2005,"date":"2005","journal":"Journal of applied microbiology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"AIMS: To determine the effectiveness of an alkaline cleaner used in food-processing plants and a lytic bacteriophage specific for Escherichia coli O157:H7 in killing wild type and rpoS-deficient cells of the pathogen in a biofilm. METHODS AND RESULTS: Wild type and rpoS-deficient cells were attached to stainless steel coupons (c. 7-8 log CFU per coupon) on which biofilms were developed during incubation at 22 degrees C for 96 h in M9 minimal salts media (MSM) with one transfer to fresh medium. Coupons were treated with 100 and 25% working concentrations of a commercial alkaline cleaner (pH 11.9, with 100 microg ml(-1) free chlorine) used in the food industry, chlorine solutions (50 and 100 microg ml(-1) free chlorine), or sterile deionized water (control) at 4 degrees C for 1 and 3 min. Treatment with 100% alkaline cleaners reduced populations by 5-6 log CFU per coupon, a significant (P < or = 0.05) reduction compared with treatment with water. Initial populations (2.6 log CFU per coupon) of attached cells of both strains were reduced by 1.2 log CFU per coupon when treated with bacteriophage KH1 (7.7 log PFU ml(-1)) for up to 4 days at 4 degrees C. Biofilms containing low populations (2.7-2.8 log CFU per coupon) of wild type and rpoS-deficient cells that had developed for 24 h at 22 degrees C were not decreased by more than 1 log CFU per coupon when treated with KH1 (7.5 log PFU ml(-1)) at 4 degrees C. CONCLUSIONS: Higher numbers of cells of E. coli O157:H7 in biofilms are killed by treatment with an alkaline cleaner than with hypochlorite alone, possibly through a synergistic mechanism of alkaline pH and hypochlorite. Populations of cells attached on coupons were reduced by treating with bacteriophage but cells enmeshed in biofilms were protected. SIGNIFICANCE AND IMPACT OF THE STUDY: The alkaline pH, in combination with hypochlorite, in a commercial cleaner is responsible for killing E. coli O157:H7 in biofilms. Treatment with bacteriophage KH1 reduces populations of cells attached to coupon surfaces but not cells in biofilms.","pmid":"16108786","doi":"10.1111/j.1365-2672.2005.02659.x","url":"https://pubmed.ncbi.nlm.nih.gov/16108786/"},{"id":2345,"title":"Methionine sulfoxide and proteolytic cleavage contribute to the inactivation of cathepsin G by hypochlorous acid: an oxidative mechanism for regulation of serine proteinases by myeloperoxidase.","authors":"Shao, Baohai; Belaaouaj, Abderrazzaq; Verlinde, Christophe L M J; Fu, Xiaoyun; Heinecke, Jay W","year":2005,"date":"2005 Aug 12","journal":"The Journal of biological chemistry","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Using myeloperoxidase and hydrogen peroxide, activated neutrophils produce high local concentrations of hypochlorous acid (HOCl). They also secrete cathepsin G, a serine protease implicated in cytokine release, receptor activation, and degradation of tissue proteins. Isolated cathepsin G was inactivated by HOCl but not by hydrogen peroxide in vitro. We found that activated neutrophils lost cathepsin G activity by a pathway requiring myeloperoxidase, suggesting that oxidants generated by myeloperoxidase might regulate cathepsin G activity in vivo. Tandem mass spectrometric analysis of oxidized cathepsin G revealed that loss of a peptide containing Asp108, which lies in the active site, associated quantitatively with loss of enzymatic activity. Catalytic domain peptides containing Asp108 were lost from the oxidized protein in concert with the conversion of Met110 to the sulfoxide. Release of this peptide was blocked by pretreating cathepsin G with phenylmethylsulfonyl fluoride, strongly implying that oxidation introduced proteolytic cleavage sites into cathepsin G. Model system studies demonstrated that methionine oxidation can direct the regiospecific proteolysis of peptides by cathepsin G. Thus, oxidation of Met110 may contribute to cathepsin G inactivation by at least two distinct mechanisms. One involves direct oxidation of the thioether residue adjacent to the aspartic acid in the catalytic domain. The other involves the generation of new sites that are susceptible to proteolysis by cathepsin G. These observations raise the possibility that oxidants derived from neutrophils restrain pericellular proteolysis by inactivating cathepsin G. They also suggest that methionine oxidation could render cathepsin G susceptible to autolytic cleavage. Myeloperoxidase may thus play a previously unsuspected role in regulating tissue injury by serine proteases during inflammation.","pmid":"15967795","doi":"10.1074/jbc.M504040200","url":"https://pubmed.ncbi.nlm.nih.gov/15967795/"},{"id":2346,"title":"Reactive sulfur species: kinetics and mechanism of the oxidation of cystine by hypochlorous acid to give N,N'-dichlorocystine.","authors":"Nagy, Péter; Ashby, Michael T","year":2005,"date":"2005 Jun","journal":"Chemical research in toxicology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Cystine and HOCl (a neutrophil-derived oxidant) react to form an intermediate that has a half-life of ca. 5 min at pH 7.5. The intermediate subsequently decomposes to eventually yield a mixture of cystine, higher oxides of Cys, and other uncharacterized species. Spectral titrations, transitory (1)H NMR and UV-vis spectra, and the reaction properties of the intermediate are consistent with a formulation of N,N'-dichlorocystine {NDC = [-SCH(2)CH(NHCl)(CO(2)H)](2)}. The reaction of equimolar amounts of HOCl with cystine at pH 11.3 does not yield N-chlorocystine [NCC = (-O2C)(H3N+)CHCH(2)SSCH(2)CH(NHCl)(CO(2)H)] but rather a 1:1 mixture of NDC and cystine. This result could be explained by two mechanisms: rapid disproportionation of NCC to produce NDC and cystine or a faster reaction of the second equivalent of HOCl with NCC than the first equivalent of HOCl reacts with cystine. The latter mechanism is favored because of our observation by NMR spectroscopy that NDC decomposes via a species that we have assigned as NCC. Thus, disproportionation of NCC is apparently a relatively slow process. The rates of reaction of cystine(0) = [-SCH(2)CH(NH(3)(+))(CO(2)(-))](2) degrees , cystine(1-) = [((-)O(2)C)(H(2)N)CHCH(2)SSCH(2)CH(NH(3)(+))(CO(2)(-))](-), and cystine(2-) = [-SCH(2)CH(NH2)(CO2)(-))]2(2-) have been investigated, and it is clear that cystine(0) is unreactive, whereas cystine(2-) is about four times more reactive than cystine(1-). Accordingly, the following mechanism is proposed (constants for 5 degrees C): HOCl = H+ + OCl-, pK1 = 7.47; cystine(0) = cystine(1-) + H+, pK2 = 8.15; cystine(1-) = cystine(2-) + H+, pK3 = 9.00; cystine(1-) + HOCl --> NCC(1-) + H2O, k4 = 4.3(2) x 10(6) M(-1) s(-1); cystine(2-) + HOCl --> NCC(2)(-) + H2O, k5 = 1.6(2) x 10(7) M(-1) s(-1); NCC(1-) --> NCC(2-) + H+, k6 = fast; NCC(2-) + HOCl --> NDC(2-) + H2O, k7 = fast. At physiologic pH, the k4 pathway dominates. The generation of long-lived chloramine derivatives of cystine may have physiological consequences, since such compounds are known to react with nucleophiles via mechanisms that are also characteristic of HOCl, electrophilic transfer C+.","pmid":"15962926","doi":"10.1021/tx050079r","url":"https://pubmed.ncbi.nlm.nih.gov/15962926/"},{"id":2347,"title":"Oxidation of heparan sulphate by hypochlorite: role of N-chloro derivatives and dichloramine-dependent fragmentation.","authors":"Rees, Martin D; Pattison, David I; Davies, Michael J","year":2005,"date":"2005 Oct 1","journal":"The Biochemical journal","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Activated phagocytes release the haem enzyme MPO (myeloperoxidase) and produce superoxide radicals and H2O2 via an oxidative burst. MPO uses H2O2 and Cl- to form HOCl, the physiological mixture of hypochlorous acid and its anion present at pH 7.4. As MPO binds to glycosaminoglycans, oxidation of extracellular matrix and cell surfaces by HOCl may be localized to these materials. However, the reactions of HOCl with glycosaminoglycans are poorly characterized. The GlcNAc (N-acetylglucosamine), GlcNSO3 (glucosamine-N-sulphate) and GlcNH2 [(N-unsubstituted) glucosamine] residues of heparan sulphate are potential targets for HOCl. It is shown here that HOCl reacts with each of these residues to generate N-chloro derivatives, and the absolute rate constants for these reactions have been determined. Reaction at GlcNH2 residues yields chloramines and, subsequently, dichloramines with markedly slower rates, k2 approximately 3.1x10(5) and 9 M(-1) x s(-1) (at 37 degrees C) respectively. Reaction at GlcNSO3 and GlcNAc residues yields N-chlorosulphonamides and chloramides with k2 approximately 0.05 and 0.01 M(-1) x s(-1) (at 37 degrees C) respectively. The corresponding monosaccharides display a similar pattern of reactivity. Decay of the polymer-derived chloramines, N-chlorosulphonamides and chloramides is slow at 37 degrees C and does not result in major structural changes. In contrast, dichloramine decay is rapid at 37 degrees C and results in fragmentation of the polymer backbone. Computational modelling of the reaction of HOCl with heparan sulphate proteoglycans (glypican-1 and perlecan) predicts that the GlcNH2 residues of heparan sulphate are major sites of attack. These results suggest that HOCl may be an important mediator of damage to glycosaminoglycans and proteoglycans at inflammatory foci.","pmid":"15932347","doi":"10.1042/BJ20050630","url":"https://pubmed.ncbi.nlm.nih.gov/15932347/"},{"id":2350,"title":"Mechanism of interaction of betanin and indicaxanthin with human myeloperoxidase and hypochlorous acid.","authors":"Allegra, Mario; Furtmüller, Paul Georg; Jantschko, Walter; Zederbauer, Martina; Tesoriere, Luisa; Livrea, Maria A; Obinger, Christian","year":2005,"date":"2005 Jul 8","journal":"Biochemical and biophysical research communications","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCl) is the most powerful oxidant produced by human neutrophils and contributes to the damage caused by these inflammatory cells. It is produced from H2O2 and chloride by the heme enzyme myeloperoxidase (MPO). Based on findings that betalains provide antioxidant and anti-inflammatory effects, we performed the present kinetic study on the interaction between the betalains, betanin and indicaxanthin, with the redox intermediates, compound I and compound II of MPO, and its major cytotoxic product HOCl. It is shown that both betalains are good peroxidase substrates for MPO and function as one-electron reductants of its redox intermediates, compound I and compound II. Compound I is reduced to compound II with a second-order rate constant of (1.5+/-0.1) x 10(6) M(-1) s(-1) (betanin) and (1.1+/-0.2) x 10(6) M(-1) s(-1) (indicaxanthin), respectively, at pH 7.0 and 25 degrees C. Formation of ferric (native) MPO from compound II occurs with a second-order rate constant of (1.1+/-0.1) x 10(5) M(-1) s(-1) (betanin) and (2.9+/-0.1) x 10(5) M(-1) s(-1) (indicaxanthin), respectively. In addition, both betalains can effectively scavenge hypochlorous acid with determined rates of (1.8+/-0.2) x 10(4) M(-1) s(-1) (betanin) and (7.7+/-0.1) x 10(4) M(-1) s(-1) (indicaxanthin) at pH 7.0 and 25 degrees C. At neutral pH and depending on their concentration, both betalains can exhibit a stimulating and inhibitory effect on the chlorination activity of MPO, whereas at pH 5.0 only inhibitory effects were observed even at micromolar concentrations. These findings are discussed with respect to our knowledge of the enzymatic mechanisms of MPO.","pmid":"15913556","doi":"10.1016/j.bbrc.2005.05.031","url":"https://pubmed.ncbi.nlm.nih.gov/15913556/"},{"id":2351,"title":"Modeling physiological resistance in bacterial biofilms.","authors":"Cogan, N G; Cortez, Ricardo; Fauci, Lisa","year":2005,"date":"2005 Jul","journal":"Bulletin of mathematical biology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"A mathematical model of the action of antimicrobial agents on bacterial biofilms is presented. The model includes the fluid dynamics in and around the biofilm, advective and diffusive transport of two chemical constituents and the mechanism of physiological resistance. Although the mathematical model applies in three dimensions, we present two-dimensional simulations for arbitrary biofilm domains and various dosing strategies. The model allows the prediction of the spatial evolution of bacterial population and chemical constituents as well as different dosing strategies based on the fluid motion. We find that the interaction between the nutrient and the antimicrobial agent can reproduce survival curves which are comparable to other model predictions as well as experimental results. The model predicts that exposing the biofilm to low concentration doses of antimicrobial agent for longer time is more effective than short time dosing with high antimicrobial agent concentration. The effects of flow reversal and the roughness of the fluid/biofilm are also investigated. We find that reversing the flow increases the effectiveness of dosing. In addition, we show that overall survival decreases with increasing surface roughness.","pmid":"15893555","doi":"10.1016/j.bulm.2004.11.001","url":"https://pubmed.ncbi.nlm.nih.gov/15893555/"},{"id":2354,"title":"Green fluorescent protein-expressing Escherichia coli as a selective probe for HOCl generation within neutrophils.","authors":"Palazzolo, Amy M; Suquet, Christine; Konkel, Michael E; Hurst, James K","year":2005,"date":"2005 May 10","journal":"Biochemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Escherichia coli were transformed by electroporation to introduce a plasmid harboring a GFP gene-containing vector. The fluorescence of the purified GFP isolated from the transformant was quenched by myeloperoxidase (MPO)-generated HOCl, by peroxynitrous acid (ONOOH) and by enzymatically or radiolytically generated NO(2)(.) but not by other putative neutrophil-generated oxidants. Fluorescence from the bacterium was effectively quenched by HOCl but not peroxynitrite, oxidizing radicals derived from its O-O bond homolysis, or the other oxidants under study. Exposure of serum-opsonized bacteria to human neutrophils resulted in extensive loss of GFP fluorescence; fluorescence microscopy revealed that phagocytosed bacteria were completely quenched but that bacteria remaining in the external media were unquenched. Addition of sodium azide to the medium to inhibit MPO prevented neutrophil-mediated fluorescence quenching. Because the amount of HOCl required to inhibit bacterial fluorescence was an order of magnitude greater than required to inhibit colonial growth, these results imply that sufficient HOCl was formed within the neutrophil phagosome to kill the microbe.","pmid":"15865436","doi":"10.1021/bi047342s","url":"https://pubmed.ncbi.nlm.nih.gov/15865436/"},{"id":2357,"title":"New methods in the evaluation of chemical disinfectants used in health care services.","authors":"Vieira, Cristina Dutra; Farias, Luiz de Macêdo; Diniz, Cláudio Galuppo; Alvarez-Leite, Maria Eugênia; Camargo, Elizabeth Ribeiro da Silva; Carvalho, Maria Auxiliadora Roque de","year":2005,"date":"2005 Apr","journal":"American journal of infection control","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"BACKGROUND: A considerable number of tests are recommended in the literature to evaluate in vitro commercial chemical solutions. The variety of tests reflects their limitations and the need to enhance disinfection process. METHODS: In this study the efficacy of 4 chemical disinfectants selected by their practical use in Health Care Services and by literature recommendation in aerobic and in strict anaerobic bacteria were evaluated by their practical use in Health Care Services and by literature recommendation in aerobic and in strict anaerobic bacteria. Viability was tested in biofilms grown on glass and rubber tip carriers. RESULTS: The results showed microbial growth in chemical solutions at concentrations recommended by the literature or at very close concentrations to them. Viable cells were recovered from biofilms after 30 minutes (Bacteroides fragilis) and 60 minutes (Streptococcus mutans and Salmonella tiphymurium) contact with 2.4% glutaraldehyde and after 60 minutes (S tiphymurium) in 2.0% glutaraldehyde. In 70% ethyl alcohol, S tiphymurium was viable up to 10 minutes, Escherichia coli up to 30 minutes, and S mutans up to 60 minutes. In 1% sodium hypochlorite, S mutans was viable up to 30 minutes and S tiphymurium up to 45 minutes. Detection of cell viability could be related to methodologic differences, including biofilm formation, as demonstrated by scanning electron microscopy. It should be emphasized that B fragilis, the most clinically relevant obligate anaerobe, remained viable in one routinely used solution. CONCLUSION: These findings pointed out the need of periodic surveillance of disinfectants' activity used in Health Care Services and the need of reviewing routines of disinfection protocols.","pmid":"15798671","doi":"10.1016/j.ajic.2004.10.007","url":"https://pubmed.ncbi.nlm.nih.gov/15798671/"},{"id":2358,"title":"Exploitation of the unusual thermodynamic properties of human myeloperoxidase in inhibitor design.","authors":"Jantschko, Walter; Furtmüller, Paul Georg; Zederbauer, Martina; Neugschwandtner, Karin; Lehner, Isabella; Jakopitsch, Christa; Arnhold, Jürgen; Obinger, Christian","year":2005,"date":"2005 Apr 15","journal":"Biochemical pharmacology","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Myeloperoxidase plays a fundamental role in oxidant production by neutrophils. It uses hydrogen peroxide and chloride to catalyze the production of hypochlorous acid (HOCl), which contributes to both bacterial killing and oxidative injury of host tissue. Thus, MPO is an interesting target for anti-inflammatory therapy. Here, based on the extraordinary and MPO-specific redox properties of its intermediates compound I and compound II, we present a rational approach in selection and design of reversible inhibitors of HOCl production mediated by MPO. In detail, indole and tryptamine derivatives were investigated for their ability to reduce compounds I and II and to affect the chlorinating activity of MPO. It is shown that these aromatic one-electron donors bound to the hydrophobic pocket at the distal heme cavity and were oxidized efficiently by compound I (k3), which has a one-electron reduction potential of 1.35 V. By contrast, compound II (E degrees ' of the compound II/ferric couple is 0.97 V) reduction (k4) was extremely slow. As a consequence compound II, which does not participate in the halogenation cycle, accumulated. The extent of chlorinating activity inhibition (IC50) was related to the k3/k4 ratio. The most efficient inhibitors were 5-fluorotryptamine and 5-chlorotryptamine with IC50 of 0.79 microM and 0.73 microM and k3/k4 ratios of 386,000 and 224,000, respectively. The reversible mechanism of inhibition is discussed with respect to the enzymology of MPO and the development of drugs against HOCl-dependent tissue damage.","pmid":"15794935","doi":"10.1016/j.bcp.2005.02.006","url":"https://pubmed.ncbi.nlm.nih.gov/15794935/"},{"id":2359,"title":"[Semicarbazide in food].","authors":"Yamamoto, Miyako; Uneyama, Chikako; Toda, Miou; Morikawa, Kaoru","year":2004,"date":"2004 Dec","journal":"Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan","category":"Food & agriculture","evidence":"Review","relevance":"High","abstract":"","pmid":"15794098","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/15794098/"},{"id":2360,"title":"Role of environmental cleaning in controlling an outbreak of Acinetobacter baumannii on a neurosurgical intensive care unit.","authors":"Denton, M; Wilcox, M H; Parnell, P; Green, D; Keer, V; Hawkey, P M; Evans, I; Murphy, P","year":2005,"date":"2005 Apr","journal":"Intensive & critical care nursing","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"An outbreak of Acinetobacter baumannii colonization and infection occurred in 19 patients over a 14-month period during 1998-1999 on a neurosurgical intensive care unit. During efforts to control the outbreak a significant correlation was observed between the number of environmental isolates of A. baumannii obtained during each monthly screening and the number of patients with A. baumannii colonization/infection in the same calendar month (P=0.004). Use of 1000 ppm hypochlorite solution and the introduction of new cleaning protocols reduced the number of environmental isolates. Failure to maintain low levels of environmental contamination with A. baumannii resulted in increases in patient colonization. This study showed that high standards of cleaning play an integral role in controlling outbreaks of A. baumannii in the intensive care unit setting.","pmid":"15778073","doi":"10.1016/j.iccn.2003.10.008","url":"https://pubmed.ncbi.nlm.nih.gov/15778073/"},{"id":2361,"title":"Genotoxicity of the disinfection by-products resulting from peracetic acid- or hypochlorite-disinfected sewage wastewater.","authors":"Crebelli, R; Conti, L; Monarca, S; Feretti, D; Zerbini, I; Zani, C; Veschetti, E; Cutilli, D; Ottaviani, M","year":2005,"date":"2005 Mar","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Wastewater disinfection is routinely carried out to prevent the spread of human pathogens present in wastewater effluents. To this aim, chemical and physical treatments are applied to the effluents before their emission in water bodies. In this study, the influence of two widely used disinfectants, peracetic acid (PAA) and sodium hypochlorite (NaClO), on the formation of mutagenic by-products was investigated. Wastewater samples were collected before and after disinfection, in winter and in summer, at a pilot plant installed in a municipal wastewater-treatment plant. Samples were adsorbed using silica C18 cartridges and the concentrates were tested for mutagenicity in the Salmonella typhimurium reversion test with strains TA98 and TA100. Non-concentrated water samples were tested with two plant genotoxicity assays (the Allium cepa root anaphase aberration test and the Tradescantia/micronucleus test). Mutagenicity assays in bacteria and in Tradescantia showed borderline mutagenicity in some of the wastewater samples, independent of the disinfection procedure applied. Negative results were obtained in the A. cepa anaphase aberration test. These results indicate that, in the conditions applied, wastewater disinfection with PAA and NaClO does not lead to the formation of significant amounts of genotoxic by-products.","pmid":"15766965","doi":"10.1016/j.watres.2004.12.029","url":"https://pubmed.ncbi.nlm.nih.gov/15766965/"},{"id":2364,"title":"Hypochlorous acid scavenging properties of local Mediterranean plant foods.","authors":"Schaffer, Sebastian; Eckert, Gunter P; Müller, Walter E; Llorach, Rafael; Rivera, Diego; Grande, Simona; Galli, Claudio; Visioli, Francesco","year":2004,"date":"2004 Dec","journal":"Lipids","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Oxidative modification of low density lipoprotein (LDL) is involved in the pathogenesis of atherosclerosis and coronary heart disease, which are low in the Mediterranean area possibly due to a high dietary proportion of plant foods. Ethanolic extracts were prepared from more than 120 Mediterranean edible plants collected in remote areas (which maintain their traditional diet) and their antioxidant potential was studied. Extracts derived from Agaricus campestris, Cynara cardunculus, Thymus pulegioides, and Vicia faba were subjected to further analysis in this study. The extracts' potential to scavenge the DPPH radical (2,2-diphenyl-1-picrylhydrazyl radical) and hypochlorous acid (HOCl), as well as their antioxidant capacity, was comparable to the those obtained for standard antioxidants (e.g., quercetin, Trolox). Myeloperoxidase (MPO) catalyzes the production of the highly chlorinating and oxidizing agent HOCl, which reacts with the LDL apoprotein moiety, leading to the derivatization of its aminoacidic residues. Coincubation with extracts significantly prevented HOCl-induced modification of the LDL residue tryptophan, whereas higher concentrations were required to retard lysine damage. Moreover, the extracts inhibited MPO-catalyzed guaiacol oxidation in a concentration-dependent manner in a cell-free assay but, in contrast, did not affect MPO activity in isolated human neutrophils. MPO is also known to facilitate nitric dioxide oxidation. The formation of 3-nitrotyrosine was significantly lower in bovine endothelial aortic cells incubated with C. cardunculus or T. pulegioides. In synthesis, our study shows that local Mediterranean plant foods prevent HOCl toxicity in vitro and, thus, suggests further mechanisms responsible for the reported health-beneficial effect of the Mediterranean diet.","pmid":"15736921","doi":"10.1007/s11745-004-1353-9","url":"https://pubmed.ncbi.nlm.nih.gov/15736921/"},{"id":2366,"title":"1H NMR analysis as a diagnostic probe for human saliva.","authors":"Grootveld, Martin; Silwood, Christopher J L","year":2005,"date":"2005 Apr 1","journal":"Biochemical and biophysical research communications","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The applications of high resolution (1)H NMR analysis as a diagnostic probe for human saliva are reviewed with special reference to diabetes mellitus, and a recently published report regarding the ability of this technique to detect advanced glycation endproducts (AGEs) in this biofluid [Biochem. Biophys. Res. Commun. 323 (2004) 377-381]. We also demonstrate that hypochlorous acid/hypochlorite (HOCl/OCl(-))-induced modifications to the (1)H NMR profiles of human salivary supernatants arise from the chlorination and, where appropriate, oxidation of amino acids and malodorous amines, together with the oxidation of carbohydrates and alpha-keto acid anions. The attack of HOCl/OCl(-) on carbohydrates yields formate (singlet, delta = 8.46 ppm), the (1)H NMR signal of which was erroneously assigned to AGE species by the authors of [Biochem. Biophys. Res. Commun. 323 (2004) 377-381].","pmid":"15721264","doi":"10.1016/j.bbrc.2005.01.112","url":"https://pubmed.ncbi.nlm.nih.gov/15721264/"},{"id":2367,"title":"Chlorine transfer between glycine, taurine, and histamine: reaction rates and impact on cellular reactivity.","authors":"Peskin, Alexander V; Midwinter, Robyn G; Harwood, David T; Winterbourn, Christine C","year":2005,"date":"2005 Feb 1","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid formed by activated neutrophils reacts with amines to produce chloramines. Chloramines vary in stability, reactivity, and cell permeability. We have examined whether chloramine exchange occurs between physiologically important amines or amino acids and if this affects interactions of chloramines with cells. We have demonstrated transchlorination reactions between histamine, glycine, and taurine chloramines by measuring chloramine decay rates with mixtures as well as by mass spectrometry. Kinetic analysis suggested the formation of an intermediate complex with a high Km. Apparent second-order rate constants, determined for concentrations <Km, were 19.4, 23.8, 6.0, and 7.5 M(-1) min(-1) for glycine chloramine (Gly-Cl) and taurine, Gly-Cl and histamine, histamine chloramine and glycine, and taurine chloramine (Tau-Cl) and glycine, respectively. Thus with 10 mM amine concentrations, half-lives for chloramine exchange are of the order of a few minutes. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity in cells was measured as an indicator of permeability of the chloramines. When endothelial or Jurkat cells were treated in Hanks' buffer, Gly-Cl inhibited GAPDH, whereas Tau-Cl, which does not penetrate the cells, did not. Adding glycine to Tau-Cl brought about inhibition, whereas taurine mitigated the effect of Gly-Cl. For cells in full medium, high chloramine concentrations were needed to inhibit GAPDH because of scavenging by methionine and other constituents. In methionine-free medium, chlorine exchange resulted in GAPDH inhibition by Tau-Cl, whereas Gly-Cl was less effective than in Hanks' buffer. Thus interchange between chloramines occurs readily and modulates their cellular effects.","pmid":"15693173","doi":"10.1016/j.freeradbiomed.2004.11.006","url":"https://pubmed.ncbi.nlm.nih.gov/15693173/"},{"id":2370,"title":"Myeloperoxidase plays critical roles in killing Klebsiella pneumoniae and inactivating neutrophil elastase: effects on host defense.","authors":"Hirche, Tim O; Gaut, Joseph P; Heinecke, Jay W; Belaaouaj, Azzaq","year":2005,"date":"2005 Feb 1","journal":"Journal of immunology (Baltimore, Md. : 1950)","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Activated neutrophils use myeloperoxidase (MPO) to generate an array of potent toxic oxidants. In the current studies we used genetically altered mice deficient in MPO to investigate the role of the enzyme in host defense against the Gram-negative bacterium Klebsiella pneumoniae, an important human pathogen. For comparison, we used mice deficient in the antimicrobial molecule, neutrophil elastase (NE). When challenged i.p., mice deficient in either MPO or NE were markedly more susceptible to bacterial infection and death. In vitro studies suggested that MPO impairs the morphology of bacteria in a distinctive way. Of importance, our in vitro studies found that MPO mediated oxidative inactivation of NE, an enzyme that has been widely implicated in the pathogenesis of various tissue-destructive diseases. This pathway of oxidative inactivation may be physiologically relevant, because activated neutrophils isolated from MPO-deficient mice exhibited increased elastase activity. Our observations provide strong evidence that MPO, like NE, is a key player in the killing of K. pneumoniae bacteria. They also suggest that MPO may modulate NE to protect the host from the tissue-degrading activity of this proteinase.","pmid":"15661916","doi":"10.4049/jimmunol.174.3.1557","url":"https://pubmed.ncbi.nlm.nih.gov/15661916/"},{"id":2376,"title":"Aqueous chlorination kinetics of some endocrine disruptors.","authors":"Deborde, Marie; Rabouan, Sylvie; Gallard, Hervé; Legube, Bernard","year":2004,"date":"2004 Nov 1","journal":"Environmental science & technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The aqueous chlorination kinetics of six endocrine disruptors (EDs: 4-n-nonylphenol, beta-estradiol, estrone, estriol, 17alpha-ethinylestradiol, progesterone) were studied in the 3.50-12.00 pH range, at 20+/-2 degrees C, in the presence of an excess of total chlorine. Under these conditions, all molecules with a phenolic group in their structure were rapidly oxidized by chlorine, whereas progesterone remained unchanged. In the first step, apparent kinetic rate constants were determined at various pH levels. Then each elementary reaction kinetic rate constant, i.e., the reaction of hypochlorous acid (HOCl) with ionized EDs and neutral EDs and an acid-catalyzed reaction of HOCl with neutral EDs, was calculated in the second step. The results showed that chlorination exhibits a second-order reaction rate. The rate constants for the acid-catalyzed reaction ranged from 3.02 x 10(4) M(-1) s(-1) (for 4-n-nonylphenol) to 1.82-2.62 x 10(5) M(-1) s(-1) (for hormones). The rate constants of HOCI reactions with ionized EDs were found to be equal to 7.5 x 10(4) M(-1) s(-1) (for 4-n-nonylphenol) and between 3.52 and 4.15 x 10(5) M(-1) s(-1) (for hormones), while the rate contants of HOCI with neutral EDs were much lower, i.e., between 1.31 M(-1) s(-1) (for 4-n-nonylphenol) and 3.74-4.82 M(-1) s(-1) (for hormones). At pH 7, the apparent-second-order rate constants were calculated to range from 12.6 to 131.1 M(-1) s(-1). For a total chlorine concentration of 1 mg/L, the corresponding half-life times at pH 7 were about 65 min for 4-n-nonylphenol and 6-8 min for hormones.","pmid":"15575274","doi":"10.1021/es040006e","url":"https://pubmed.ncbi.nlm.nih.gov/15575274/"},{"id":2377,"title":"Effects of phenylbutazone, indomethacin, prostaglandin E2, butyrate, and glutamine on restitution of oxidant-injured right dorsal colon of horses in vitro.","authors":"Rötting, Anna K; Freeman, David E; Constable, Peter D; Eurell, Jo Ann C; Wallig, Matthew A","year":2004,"date":"2004 Nov","journal":"American journal of veterinary research","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVE: To study the effects of phenylbutazone, indomethacin, prostaglandin E2 (PGE2), glutamine, and butyrate on restitution of oxidant-injured right dorsal colon of horses in vitro. SAMPLE POPULATION: Right dorsal colon from 9 adult horses euthanatized for reasons other than gastrointestinal tract disease. PROCEDURES: Mucosal segments from the right dorsal colon were injured via exposure to HOCl and incubated in Ussing chambers in solutions containing phenylbutazone, indomethacin, indomethacin and PGE2, glutamine, and butyrate. Transepithelial resistance and mucosal permeability to mannitol were measured, and all mucosal segments were examined histologically. RESULTS: The HOCl-injured mucosa had lower resistance and higher permeability to mannitol, compared with control tissue. Histologic changes were also evident. Resistance of HOCl-injured mucosa recovered partially during the incubation period, and glutamine improved recovery. Phenylbutazone and indomethacin increased resistance, but these increases were not significant. Butyrate and PGE2 had no effects, compared with nontreated HOCl-injured tissues. Mucosal permeability to mannitol was lower in glutamine-treated tissue, compared with nontreated tissue. Histologic changes reflected the resistance and permeability changes. CONCLUSIONS AND CLINICAL RELEVANCE: According to our findings, phenylbutazone and indomethacin do not seem to interfere with restitution of oxidant-injured mucosa of equine colon in vitro, and glutamine could facilitate mucosal restitution.","pmid":"15566100","doi":"10.2460/ajvr.2004.65.1589","url":"https://pubmed.ncbi.nlm.nih.gov/15566100/"},{"id":2378,"title":"Safety and protective effect of a disinfectant (STEL water) for white spot syndrome viral infection in shrimp.","authors":"Park, Jong-Hwan; Seok, Seung-Hyeok; Cho, Sun-a; Baek, Min-Won; Lee, Hui-Young; Kim, Dong-Jae; Kim, Han-Yun; Chang, Se-Ok; Park, Jae-Hak","year":2004,"date":"2004 Sep 8","journal":"Diseases of aquatic organisms","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The efficacy of STEL water for protection against white spot syndrome virus (WSSV) infection was evaluated using shrimp. The LC50 of residual chlorine (Cl-) in STEL water for brood-stock and 2-mo-old shrimp were 2.3 and 3.2 ppm, respectively. All 2-month-old shrimp raised in seawater containing more than 40 microl 2l(-1) of a WSSV-infected tissue homogenate died within 3 d post-exposure (dpe). Thus, a 10-fold dose of 400 microl 2 l(-1) was used in the disinfection tests. Low concentrations of STEL water effectively prevented mortality of shrimp at this challenge dose. All 2-month-old shrimp exposed to seawater with 400 microl of viral homogenate disinfected with STEL water at Cl- concentrations over 0.125 ppm for 1 and 10 min, lived until 5 dpe. With 5-mo-old shrimp, all positive control shrimps died within 3 dpe, whereas most shrimp reared in seawater disinfected with STEL water for 1 h before addition of homogenate lived until 5 dpe. Results suggested that continuous disinfection of seawater with STEL water may be effective for preventing WSSV infection in shrimp.","pmid":"15521325","doi":"10.3354/dao060253","url":"https://pubmed.ncbi.nlm.nih.gov/15521325/"},{"id":2382,"title":"Hypochlorous acid and taurine-N-monochloramine in periodontal diseases.","authors":"Mainnemare, A; Mégarbane, B; Soueidan, A; Daniel, A; Chapple, I L C","year":2004,"date":"2004 Nov","journal":"Journal of dental research","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"Chronic periodontitis is a multi-factorial disease involving anaerobic bacteria and the generation of an inflammatory response, including the production of metalloproteinases, pro-inflammatory cytokines, and eicosanoids. Hypochlorous acid (HOCl) and taurine-N-monochloramine (TauCl) are the end-products of the neutrophilic polymorphonuclear leukocyte (PMN) respiratory burst. They act synergistically to modulate the inflammatory response. In the extracellular environment, HOCl and TauCl may directly neutralize interleukin 6 (IL-6) and several metalloproteinases, while HOCl increases the capacity of alpha(2)-macroglobulin to bind Tumor Necrosis Factor-alpha, IL-2, and IL-6, and facilitates the release of various growth factors. TauCl inhibits the production of inflammatory mediators, prostaglandins, and nitric oxide. HOCl activates tyrosine kinase signaling cascades, generating an increase in the production of extracellular matrix components, growth factors, and inflammatory mediators. Thus, HOCl and TauCl appear to play a crucial role in the periodontal inflammatory process. Taken together, these findings may offer opportunities for the development of novel host-modulating therapies for the treatment of periodontitis.","pmid":"15505230","doi":"10.1177/154405910408301101","url":"https://pubmed.ncbi.nlm.nih.gov/15505230/"},{"id":2383,"title":"Contribution of brominated organic disinfection by-products to the mutagenicity of drinking water.","authors":"Echigo, S; Itoh, S; Natsui, T; Araki, T; Ando, R","year":2004,"date":"2004","journal":"Water science and technology : a journal of the International Association on Water Pollution Research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The activity inducing chromosomal aberrations of the mixture of brominated disinfection by-products (DBPs) was approximately three times higher than that of the chlorinated counterparts for the same hypohalous acid dose. With the combination of chromosomal aberration test and a new analytical technique to differentiate total organic chlorine (TOCl) and total organic bromine (TOBr), it was found that TOBr was correlated to the mutagenicity of chlorinated waters. It was also implied that for a bromide-to-TOC ratio of 0.1 (mg/mg C), brominated DBPs could account for at least 29% of the total toxicity of DBPs formed during chlorination. On the other hand, bromate ion, a major ozonation DBP, was not a major contributor to the activity inducing chromosomal aberrations of the water treated with an ozone/chlorine sequential process. Therefore, ozonation is one possible option to reduce the health risk caused by DBPs even in the presence of bromide.","pmid":"15497864","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/15497864/"},{"id":2384,"title":"Chlorine transfer between glycine, taurine, and histamine: reaction rates and impact on cellular reactivity.","authors":"Peskin, Alexander V; Midwinter, Robyn G; Harwood, David T; Winterbourn, Christine C","year":2004,"date":"2004 Nov 15","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid formed by activated neutrophils reacts with amines to produce chloramines. Chloramines vary in stability, reactivity, and cell permeability. We have examined whether chloramine exchange occurs between physiologically important amines or amino acids and if this affects interactions of chloramines with cells. We have demonstrated transchlorination reactions between histamine, glycine, and taurine chloramines by measuring chloramine decay rates with mixtures as well as by mass spectrometry. Kinetic analysis suggested the formation of an intermediate complex with a high K(m). Apparent second-order rate constants, determined for concentrations <K(m), were 19.4, 23.8, 6.0, and 7.5 M(-1) min(-1) for glycine chloramine (Gly-Cl) and taurine, Gly-Cl and histamine, histamine chloramine and glycine, and taurine chloramine (Tau-Cl) and glycine, respectively. Thus with 10 mM amine concentrations, half-lives for chloramine exchange are on the order of a few minutes. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity in cells was measured as an indicator of permeability of the chloramines. When endothelial or Jurkat cells were treated in Hanks' buffer, Gly-Cl inhibited GAPDH, whereas Tau-Cl, which does not penetrate the cells, did not. Adding glycine to Tau-Cl brought about inhibition, whereas taurine mitigated the effect of Gly-Cl. For cells in full medium, high chloramine concentrations were needed to inhibit GAPDH because of scavenging by methionine and other constituents. In methionine-free medium, chlorine exchange resulted in GAPDH inhibition by Tau-Cl, whereas Gly-Cl was less effective than in Hanks' buffer. Thus interchange between chloramines occurs readily and modulates their cellular effects.","pmid":"15477013","doi":"10.1016/j.freeradbiomed.2004.08.010","url":"https://pubmed.ncbi.nlm.nih.gov/15477013/"},{"id":2387,"title":"Oxidative modification of type II collagen differentially affects its arthritogenic and tolerogenic capacity in experimental arthritis.","authors":"Marcinkiewicz, Janusz; Biedroń, Rafał; Maresz, Katarzyna; Kwaśny-Krochin, Beata; Bobek, Małgorzata; Kontny, Ewa; Maśliński, Wlodzimierz; Chain, Benjamin","year":2004,"date":"2004 Jul-Aug","journal":"Archivum immunologiae et therapiae experimentalis","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"INTRODUCTION: Oxidative modification of proteins affects their biological properties. Previously we have shown that hypochlorite (HOCl), the product of activated neutrophils, enhances protein immunogenecity. Collagen type II, a primary component of cartilage, is commonly used in the induction of arthritis in animals (CIA). The aim of this study was to examine whether HOCl may affect immunogenic, tolerogenic, and arthritogenic properties of collagen. MATERIALS AND METHODS: DBA/J mice were injected with either native (CNAT) or chlorinated collagen (CHOCl) to induce arthritis. The effect of chlorination on collagen properties was measured by evaluation of incidence and severity of CIA. Moreover, the concentration of serum anti-collagen IgG antibodies and myeloperoxidase (MPO) activity in inflamed joints was determined. RESULTS: Mice immunized with CNAT in adjuvant developed arthritis (CIA) with an incidence of 69%. CNAT also exerted tolerogenic properties when injected intravenously either before or shortly after primary immunization, resulting in decreased incidence and severity of CIA, reduced MPO activity in inflamed joints, and lowered serum levels of anti-CNAT IgG anti-bodies. Chlorination of collagen significantly diminished its ability to induce CIA and to trigger generation of anti-CNAT IgG antibodies. Interestingly, chlorination did not affect tolerogenic properties of collagen administered prior to primary immunization with CNAT. CONCLUSIONS: These results suggest that chlorination of collagen may selectively affect functional epitopes of collagen. It is likely that in inflamed joints, neutrophil derived HOCl, in some circumstances, will destroy arthritogenic and immunogenic B cell epitopes, while regulatory T cell epitopes will be preserved.","pmid":"15467493","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/15467493/"},{"id":2389,"title":"Oxidized caprine alpha-2-macroglobulin: damaged but not completely dysfunctional.","authors":"Khan, Shakil A; Khan, Fahim H","year":2004,"date":"2004 Sep 24","journal":"Biochimica et biophysica acta","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Caprine alpha-2-macroglobulin (alpha2M) is a broad-spectrum, homotetrameric proteinase inhibitor that can maximally bind a single molecule of proteinase. Inhibition of proteinases by caprine alpha2M results from a series of conformational changes that are initiated by the proteinase and results in physical sequestration of the proteinase within the closed cage-like structure of conformationally altered alpha2M. In a previous study, uric acid-generated superoxide anion was identified as one of the physiologically relevant inactivators of alpha2M S.A. Khan, F.H. Khan [Free. Radic. Res. 34 (2001) 113]. We now demonstrate that hypochlorous acid (HOCl) and, to lesser extent, hydrogen peroxide (H2O2) destroy the antiproteolytic potential of caprine alpha2M. At physiologically attainable concentration, we found that HOCl significantly compromised functional integrity of the inhibitor. High concentrations of H2O2 also partially diminished proteinase inhibitory capacity of alpha2M by a mechanism not involving formation of hydroxyl radicals. For hydrogen peroxide, catalase completely protected alpha2M activity while the ability to protect the inhibitor from HOCl-induced inactivation was limited by availability of albumin. Structure function analysis demonstrated that oxidized caprine inhibitor, unlike its human counterpart, retained its tetrameric configuration as well as its characteristic ability to undergo major conformational change upon trypsinization. It is proposed that inhibition of alpha2M activity may be due to oxidation of essential residues of the inhibitor and/or structural rearrangement of the subunits.","pmid":"15374618","doi":"10.1016/j.bbagen.2004.06.008","url":"https://pubmed.ncbi.nlm.nih.gov/15374618/"},{"id":2390,"title":"Endogenous formation of novel halogenated 2'-deoxycytidine. Hypohalous acid-mediated DNA modification at the site of inflammation.","authors":"Kawai, Yoshichika; Morinaga, Hiroshi; Kondo, Hajime; Miyoshi, Noriyuki; Nakamura, Yoshimasa; Uchida, Koji; Osawa, Toshihiko","year":2004,"date":"2004 Dec 3","journal":"The Journal of biological chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"A potential role of DNA damage by leukocyte-derived reactive species in carcinogenesis has been suggested. Leukocyte-derived peroxidases, such as myeloperoxidase and eosinophil peroxidase, use hydrogen peroxide and halides (Cl- and Br-) to generate hypohalous acids (HOCl and HOBr), halogenating intermediates. It has been suggested that these oxidants lead to the formation of halogenated products upon reaction with nucleobases. To verify the consequences of phagocyte-mediated DNA damage at the site of inflammation, we developed a novel monoclonal antibody (mAb2D3) that recognizes the hypohalous acid-modified DNA and found that the antibody most significantly recognized HOCl/HOBr-modified 2'-deoxycytidine residues. The immunoreactivity of HOCl-treated oligonucleotide was attenuated by excess methionine, suggesting that chloramine-like species may be the plausible epitopes of the antibody. On the basis of further characterization combined with mass spectrometric analysis, the epitopes of mAb2D3 were determined to be novel N4,5-dihalogenated 2'-deoxycytidine residues. The formation of the dihalogenated 2'-deoxycytidine in vivo was immunohistochemically demonstrated in the lung and liver nuclei of mice treated with lipopolysaccharides, an experimental inflammatory model. These results strongly suggest that phagocyte-derived oxidants, hypohalous acids, endogenously generate the halogenated DNA bases such as a novel dihalogenated 2'-deoxycytidine in vivo. Halogenation (chlorination and/or bromination) of DNA therefore may constitute one mechanism for oxidative DNA damage at the site of inflammation.","pmid":"15364942","doi":"10.1074/jbc.M408210200","url":"https://pubmed.ncbi.nlm.nih.gov/15364942/"},{"id":2391,"title":"Effects of cleaning and disinfection in reducing the spread of Norovirus contamination via environmental surfaces.","authors":"Barker, J; Vipond, I B; Bloomfield, S F","year":2004,"date":"2004 Sep","journal":"The Journal of hospital infection","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"A reverse transcriptase polymerase chain reaction assay was used to study the transfer of Norovirus (NV) from contaminated faecal material via fingers and cloths to other hand-contact surfaces. The results showed that, where fingers come into contact with virus-contaminated material, NV is consistently transferred via the fingers to melamine surfaces and from there to other typical hand-contact surfaces, such as taps, door handles and telephone receivers. It was found that contaminated fingers could sequentially transfer virus to up to seven clean surfaces. The effectiveness of detergent- and disinfectant-based cleaning regimes typical of those that might be used to decontaminate faecally contaminated surfaces and reduce spread of NV was also compared. It was found that detergent-based cleaning with a cloth to produce a visibly clean surface consistently failed to eliminate NV contamination. Where there was faecal soiling, although a combined hypochlorite/detergent formulation at 5000 ppm of available chlorine produced a significant risk reduction, NV contamination could still be detected on up to 28% of surfaces. In order consistently to achieve good hygiene, it was necessary to wipe the surface clean using a cloth soaked in detergent before applying the combined hypochlorite/detergent. When detergent cleaning alone or combined hypochlorite/detergent treatment failed to eliminate NV contamination from the surface and the cleaning cloth was then used to wipe another surface, the virus was transferred to that surface and to the hands of the person handling the cloth. In contrast, were surfaces where contaminated with NV-infected faecal suspension diluted to 1 in 10 and 1 in 80, intended to simulate surfaces that have become contaminated after secondary transfer, treatment with a combined bleach/detergent formulation, without prior cleaning, was sufficient to decontaminate surfaces and prevent transfer.","pmid":"15350713","doi":"10.1016/j.jhin.2004.04.021","url":"https://pubmed.ncbi.nlm.nih.gov/15350713/"},{"id":2392,"title":"Comparison of the inhibition of myeloperoxidase-catalyzed hypochlorite formation in vitro and in whole blood by different plant extracts contained in a phytopharmacon treating functional dyspepsia.","authors":"Schempp, Harald; Hippeli, Susanne; Weiser, Dieter; Kelber, Olaf; Elstner, Erich F","year":2004,"date":"2004","journal":"Arzneimittel-Forschung","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Ethanolic extracts from nine medicinal plants are combined in Iberogast (IG). This phytomedicine is successfully used in the treatment of gastrointestinal disorders. Functional gastrointestinal diseases such as non-ulcerous dyspepsia (NUD) are in many cases initiated by, or correlated to, inflammatory processes, where reactive oxygen species (ROS) play a crucial role. In this respect one prominent source of ROS are myeloperoxidase (MPO)-driven oxidation and chlorination reactions, assumed to be mainly responsible for tissue damage. In this study the contribution of the nine extracts to the overall performance of IG was compared with emphasis on MPO produced ROS. Concerning the influence on MPO-dependent chlorination reactions, it turned out that of the nine IG-components Iberis amara extract (IAE) exerted the highest activity. Furthermore, this can impressively be reproduced in an ex vivo experiment with whole blood, where neutrophilic leukocytes are activated by zymosan. Moreover, along with the extract of chamomile flowers, IAE counteracts the pro-oxidative properties of caraway, peppermint and celandine. As a consequence. IG was also efficiently inhibiting MPO-catalysed chlorinations. As shown by the addition of catalase, the pro-oxidative effects of caraway, peppermint and celandine are due to their content of hydrogen peroxide. The latter is probably an autoxidation product of certain monoterpenes in the essential oil part of these extracts. If one of the component extracts of IG is omitted, the antioxidant acitivity is reduced. Thus we conclude that all the single extracts combined in IG are of importance for the therapeutical effect, working in concert.","pmid":"15344843","doi":"10.1055/s-0031-1296989","url":"https://pubmed.ncbi.nlm.nih.gov/15344843/"},{"id":2393,"title":"Hypochlorous acid impairs endothelium-derived nitric oxide bioactivity through a superoxide-dependent mechanism.","authors":"Stocker, Roland; Huang, Annong; Jeranian, Erin; Hou, Jing Yun; Wu, Tina T; Thomas, Shane R; Keaney, John F Jr","year":2004,"date":"2004 Nov","journal":"Arteriosclerosis, thrombosis, and vascular biology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"OBJECTIVE: To determine how hypochlorous acid (HOCl), the principal product of myeloperoxidase, modulates vascular function. METHODS AND RESULTS: Rabbit arterial rings exposed to HOCl (0 to 500 micromol/L) exhibited dose- and time-dependent impairment of endothelium-dependent arterial relaxation to acetylcholine and A23187, but not the NO donor, diethylamine NONOate, suggesting that HOCl targets the endothelium. This effect was not because of cytotoxicity, as HOCl treatment produced no significant change in endothelial cell morphology or lactate dehydrogenase release. We observed HOCl-mediated endothelial cell protein oxidation by immunoreactivity to HOP-1, a monoclonal antibody specific for HOCl-oxidized protein. In support of this notion, known HOCl scavengers, such as methionine and N-acetylcysteine, partially preserved endothelium-derived NO bioactivity in response to HOCl. In an unanticipated observation, HOCl-mediated impairment of NO bioactivity was prevented by manganese superoxide dismutase in a manner dependent on its enzymatic activity. Finally, we found that HOCl reduced endothelial nitric oxide synthase dimer stability, an effect that was also inhibited by superoxide dismutase. CONCLUSIONS: Taken together, these data indicate that HOCl imparts a defect in endothelial NO production due to a superoxide-dependent reduction in endothelial nitric oxide synthase dimer stability. These data provide another mechanism whereby myeloperoxidase-derived oxidants can contribute to the impairment of NO bioactivity that is characteristic of atherosclerosis.","pmid":"15331437","doi":"10.1161/01.ATV.0000143388.20994.fa","url":"https://pubmed.ncbi.nlm.nih.gov/15331437/"},{"id":2394,"title":"External decontamination of wild leeches with hypochloric acid.","authors":"Aydin, Atakan; Nazik, Hasan; Kuvat, Samet Vasfi; Gurler, Nezahat; Ongen, Betigul; Tuncer, Serdar; Hocaoglu, Emre; Kesim, Sinan Nur","year":2004,"date":"2004 Aug 25","journal":"BMC infectious diseases","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"BACKGROUND: Medicinal leech, Hirudo medicinalis, has been used in plastic and reconstructive surgery, to relieve venous congestion and to improve the microrevascularization of flaps. In many countries, wild leeches are still provided from local markets and utilised with antibiotic prophylaxies. In this research, results of identification of bacteria in the transport fluid is reported, oral and intestinal floras and the antibiograms of the identified microorganisms are investigated. Also, to avoid possible infections, the ability of hypochloric acid, a disinfectant, to suppress the relevant microorganisms without changing the life style and behavior of leeches in terms of sucking function, is investigated. METHODS: Bacterial identifications and antibiograms of oral and intestinal flora and transport medium were performed for 10 leeches. The optimum concentration of hypochloric acid which eliminated microorganisms without affecting the viability and sucking function of the leeches were determined by dilution of hypochloric acid to 100, 50, 25, 12.5, 6.25 ppm concentrations in different groups of 25 leeches. Finally, 20 leeches were applied atraumatically to the bleeding areas of rats, the duration of suction was determined and compared statistically between the leeches treated and not treated with hypochloric acid solution. RESULTS: Aeromonas hydrophilia was the most commonly identified microorganism and found to be resistant to first generation cephalosporins, frequently used in prophylaxis at surgical wards. In the next stages of the study, the leeches were subjected to a series of diluted hypochloric acid solutions. Although disinfection of the transport material and suppression of the oral flora of hirudo medicinalis were successful in 100, 50, 25, 12.5, 6.25 ppm concentrations; 12.5 ppm solution was the greatest concentration in which hirudo medicinalis could survive and sucking function was not affected significantly. CONCLUSIONS: External decontamination of wild leeches with 12.5 ppm hypochloric acid enables bacterial suppression without causing negative effects on leech sucking function and life.","pmid":"15329153","doi":"10.1186/1471-2334-4-28","url":"https://pubmed.ncbi.nlm.nih.gov/15329153/"},{"id":2396,"title":"Hypochlorous acid inhibition by acetoacetate: implications on neutrophil functions.","authors":"da Costa, Miriani; Ximenes, Valdecir Farias; da Fonseca, Luiz Marcos","year":2004,"date":"2004 Aug","journal":"Biological & pharmaceutical bulletin","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Type-1 diabetic patients experience hyperketonemia caused by an increase in fatty acid metabolism. Thus, the aim of this study was to measure the effect of ketone bodies as suppressors of oxidizing species produced by stimulated neutrophils. Both acetoacetate and 3-hydroxybutyrate have suppressive effect on the respiratory burst measured by luminol-enhanced chemiluminescence. Through measurements of hypochlorous acid production, using neutrophils or the myeloperoxidase/H2O2/Cl- system, it was found that acetoacetate but not 3-hydroxybutyrate is able to inhibit the generation of this antimicrobial oxidant. The superoxide anion scavenging properties were confirmed by ferricytochrome C reduction and lucigenin-enhanced chemiluminescence assays. However, ketone bodies did not alter the rate of oxygen uptake by stimulated neutrophils, measured with an oxygen electrode. A strong inhibition of the expression of the cytokine IL-8 by cultured neutrophils was also observed; this is discussed with reference to the antioxidant-like property of acetoacetate.","pmid":"15305018","doi":"10.1248/bpb.27.1183","url":"https://pubmed.ncbi.nlm.nih.gov/15305018/"},{"id":2397,"title":"The potential role of neutrophils in promoting the metastatic phenotype of tumors releasing interleukin-8.","authors":"De Larco, Joseph E; Wuertz, Beverly R K; Furcht, Leo T","year":2004,"date":"2004 Aug 1","journal":"Clinical cancer research : an official journal of the American Association for Cancer Research","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"In the last decade, several groups have shown a direct correlation between the inappropriate or ectopic release of interleukin (IL)-8 by tumor cells in vitro and their growth and metastatic potential using in vivo models of tumor growth. IL-8 is a potent neutrophil chemoattractant. Neutrophils, as \"early responders\" to wounds and infections, release enzymes to remodel the extracellular matrix of the tissues through which they migrate to reach the site of the wound or infection. It is proposed that the host's cellular response to IL-8 released by tumor cells enhances angiogenesis and contributes to tumor growth and progression. The activities released by the responding neutrophils could serve as enablers of tumor cell migration through the extracellular matrix, helping them enter the vasculature and journey to new, metastatic sites. The reactive oxygen species produced by neutrophilic oxidases to kill invading organisms have the potential to interact with tumor cells to attenuate their apoptotic cascade and increase their mutational rate. It is proposed that the increase in metastatic potential of tumors ectopically releasing IL-8 is, in part, attributable to their ability to attract neutrophils. Discussed here are possible mechanisms by which the neutrophils responding to ectopic IL-8 contribute to the in vivo growth, progression, and metastatic potential of tumor cells. Possible targets are also presented for the development of therapies to attenuate the effects of the ectopic IL-8 release by tumor cells.","pmid":"15297389","doi":"10.1158/1078-0432.CCR-03-0760","url":"https://pubmed.ncbi.nlm.nih.gov/15297389/"},{"id":2402,"title":"Internalization of bacterial pathogens in tomatoes and their control by selected chemicals.","authors":"Ibarra-Sánchez, L S; Alvarado-Casillas, S; Rodríguez-García, M O; Martínez-Gonzáles, N E; Castillo, A","year":2004,"date":"2004 Jul","journal":"Journal of food protection","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The effect of different washing or sanitizing agents was compared for preventing or reducing surface and internal contamination of tomatoes by Salmonella Typhimurium and Escherichia coli O157:H7. The tomatoes were inoculated by dipping them in a bacterial suspension containing approximately 6.0 log CFU/ml of each pathogen and then rinsing them with tap water, hypochlorite solution (250 mg/liter), or lactic acid solution (2%, wt/vol). All treatments were applied by dipping or spraying, and solutions were applied at 5, 25, 35, and 55 degrees C. With the exception of the lactic acid dip at 5 degrees C, all treatments reduced both pathogens on the surfaces of the tomatoes by at least 2.9 cycles. No significantly different results were obtained (P > 0.05) with the dipping and spraying techniques. For internalized pathogens, the mean counts for tomatoes treated with water alone or with chlorine ranged from 0.8 to 2.1 log CFU/g. In contrast, after lactic acid spray treatment, all core samples of tomatoes tested negative for Salmonella Typhimurium and, except for one sample with a low but detectable count, all samples tested negative for E. coli O157:H7 with a plate count method. When the absence of pathogens was verified by an enrichment method, Salmonella was not recovered from any samples, whereas two of four samples tested positive for E. coli O157:H7 even though the counts were negative. Few cells of internalized pathogens were able to survive in the center of the tomato during storage at room temperature (25 to 28 degrees C). The average superficial pH of tomatoes treated with tap water, chlorine, or lactic acid was 4.9 to 5.2, 4.1 to 4.3, and 2.5, respectively (P < 0.05), whereas no differences were observed in the internal pH (3.6 to 3.7) of the tomatoes treated with different sanitizers. The general practice in the tomato industry is to wash the tomatoes in chlorinated water. However, chlorine is rapidly degraded by organic matter usually present in produce. Therefore, lactic acid sprays may be a more effective alternative for decontaminating tomato surfaces. The use of warm (55 degrees C) sprays could reduce pathogen internalization during washing.","pmid":"15270485","doi":"10.4315/0362-028x-67.7.1353","url":"https://pubmed.ncbi.nlm.nih.gov/15270485/"},{"id":2404,"title":"Hypochlorite scavenging activity of flavonoids.","authors":"Firuzi, Omidreza; Mladenka, Premysl; Petrucci, Rita; Marrosu, Giancarlo; Saso, Luciano","year":2004,"date":"2004 Jun","journal":"The Journal of pharmacy and pharmacology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Scavengers of hypochlorite, a highly reactive oxidant produced by activated phagocytes, could have potential therapeutic effects in diseases in which this oxidant plays a pathogenic role. Flavonoids are polyphenolic substances present in food plants and have been extensively studied for their antioxidant properties against various free radicals. Less is known about their reactivity with hypochlorite. In this study, the hypochlorite scavenging activity of flavonoids was investigated using a microplate assay recently developed in our laboratory. This method evaluates the ability of a substance to inhibit the formation of chloramines in human serum albumin upon oxidation by hypochlorite. Thirteen flavonoids were tested. Most of them inhibited human serum albumin oxidation at micro-molar concentrations and appeared more active than Trolox, a water-soluble equivalent of vitamin E. It was observed that the greater the number of hydroxyl substitutions, the greater the scavenging activity. The 3-hydroxy substitution seemed to be particularly important for scavenging activity, whereas the presence of a 2,3-double bond in the C ring did not. Flavonoids were found to be good hypochlorite scavengers in-vitro and further information is provided about the chemical aspects important for scavenging activity. Thus, flavonoids could have beneficial effects in diseases such as atherosclerosis in which hypochlorite plays a pathogenic role.","pmid":"15231046","doi":"10.1211/0022357023556","url":"https://pubmed.ncbi.nlm.nih.gov/15231046/"},{"id":2406,"title":"Renibacterium salmoninarum: effect of hypochlorite treatment, and survival in water.","authors":"Hirvelä-Koski, Varpu","year":2004,"date":"2004 Apr 21","journal":"Diseases of aquatic organisms","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"The effect of different concentrations of sodium hypochlorite on Renibacterium salmoninarum and the survival of the bacterium in autoclaved river water and groundwater were examined. The disinfection trial was performed using R. salmoninarum ATCC 33209. The concentrations of free chlorine were 10, 50, 100 and 200 mg 1(-1), the contact times were 5, 15, and 30 min and 24 h, and the test suspensions were subcultured both on Kidney disease medium (KDM2) agar and in 3 parallel KDM2 broths, which were then subcultured on KDM2 and selective KDM (SKDM) agar. The survival of the bacterium in river water and groundwater was studied using 4 isolates of R. salmoninarum including ATCC 33209. Treatment with sodium hypochlorite effectively reduced the number of culturable cells of R. salmoninarum, but use of the recovery broth showed that small numbers of cells remained viable at all concentrations of free chlorine. The numbers of R. salmoninarum decreased to an undetectable level after 4 wk incubation in the survival trials, but low numbers of colonies were again found in the subculture after 5 wk incubation. Viable cells of R. salmoninarum were still detected in subcultures of all strains after 20 wk of incubation in river water.","pmid":"15212289","doi":"10.3354/dao059027","url":"https://pubmed.ncbi.nlm.nih.gov/15212289/"},{"id":2407,"title":"Formation of semicarbazide (SEM) in food by hypochlorite treatment: is SEM a specific marker for nitrofurazone abuse?","authors":"Hoenicke, K; Gatermann, R; Hartig, L; Mandix, M; Otte, S","year":2004,"date":"2004 Jun","journal":"Food additives and contaminants","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Semicarbazide (SEM) is considered to be a characteristic protein-bound side-chain metabolite of the banned veterinary drug nitrofurazone. It is therefore used as a marker for nitrofurazone abuse. Recently, there has been concern about other sources of SEM in tissue samples, which are not linked to the illegal use of nitrofurazone. The present studies have shown that SEM can occur naturally, e.g. in algae, shrimps and eggs, and is formed from natural substances, e.g. arginine and creatine. A significant formation of SEM was observed in samples treated with hypochlorite commonly used in food processing for disinfection or bleaching. SEM was formed in different kinds of nitrogen compound-containing samples (0.3-20 microg kg(-1)) after treatment with 1% active chlorine. It was detected in the mg kg(-1) range after hypochlorite treatment (0.015% active chlorine) of creatine. Lower levels were also formed from creatinine, arginine and urea. SEM present in hypochlorite-treated carrageenan proved mostly to occur in the tissue-bound form. Therefore, differentiation between SEM from nitrofurazone abuse and SEM originating from natural constituents (due to hypochlorite treatment) seems not to be unambiguously possible.","pmid":"15204530","doi":"10.1080/02652030410001712484","url":"https://pubmed.ncbi.nlm.nih.gov/15204530/"},{"id":2413,"title":"Alteration of an autoantigen by chlorination, a process occurring during inflammation, can overcome adaptive immune tolerance.","authors":"Westman, E; Harris, H E","year":2004,"date":"2004 May","journal":"Scandinavian journal of immunology","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Autoimmune diseases are characterized by chronic inflammation in target organs and immunoreactivity towards one or multiple autoantigens. Several potential mechanisms of tolerance breaking have been postulated, one being inflammation-associated events. We have investigated whether chlorination of an autoantigen can lead to disruption of self-tolerance. Chlorination of antigens might occur during inflammation via the granulocyte-specific, myeloperoxidase-catalysed conversion of hydrogen peroxide to hypochlorous acid (HOCl). HOCl, being a strong oxidant, reacts with proteins both within cellular phagosomes and in the immediate extracellular environment. By immunizing Lew.1AV1 rats with chlorinated or unmodified rat serum albumin (RSA), we could detect tolerance-breaking effects of chlorination. RSA is a systemic autoantigen in rat not inducing antibody production upon immunization in its unmodified form. Rats immunized with chlorinated RSA (RSA-Cl) developed high titres of immunoglobulin G (IgG) specific for RSA-Cl which cross-reacted with native RSA. T cells reactive with both RSA-Cl and RSA were detected by [(3)H]-thymidine incorporation. We hence speculated that immunological tolerance established for unmodified proteins, during certain circumstances such as inflammation, might be broken by induced protein chlorination. T cells specific for the chlorinated protein can confer help to B cells recognizing both the chlorinated and the native form of the protein, leading to the formation of high-affinity autoreactive antibodies and possibly autoimmune disease.","pmid":"15140055","doi":"10.1111/j.0300-9475.2004.01428.x","url":"https://pubmed.ncbi.nlm.nih.gov/15140055/"},{"id":2414,"title":"The reactions of oxicam and sulfoanilide non steroidal anti-inflammatory drugs with hypochlorous acid: determination of the rate constants with an assay based on the competition with para-aminobenzoic acid chlorination and identification of some oxidation products.","authors":"Van Antwerpen, P; Dubois, J; Gelbcke, M; Neve, J","year":2004,"date":"2004 Mar","journal":"Free radical research","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCl) is an oxygen-derived species involved in physiological processes related to the defence of the organism that may cause adverse effects when its production is insufficiently controlled. In order to examine its reactivity with potential scavenging molecules from the non steroidal anti-inflammatory drugs (NSAIDs) family, a competition assay based on para-aminobenzoic acid (PABA) chlorination was developed. The original optimised in vitro fluorimetric procedure offered the possibility to determine rate constants (ks) for the reaction with HOCl in physiologically relevant conditions. The specificity of the system was improved by a liquid chromatography (LC) which allows the separation of the drugs and their oxidation products. After determination of the rate constant for PABA chlorination by HOCl (mean +/- SD in M(-1) s(-1): 4.3 +/- 0.3 x 10(3)), the applied mathematical model for a chemical competition permits to obtain linear curves from competition studies between several NSAIDs and PABA. Their slopes provided the following rate constants for the different studied drugs: tenoxicam: 4.0 +/- 0.7 x 10(3), piroxicam: 3.6 +/- 0.7 x 10(3), lornoxicam: 4.3 +/- 0.7 x 10(3), meloxicam: 1.7 +/- 0.3 x 10(4), nimesulide: 2.3 +/- 0.6 x 10(2). Meloxicam therefore reacted significantly faster than the other oxicams and nimesulide, which is the weakest scavenger of the studied series. The identification of some of the oxidation products by NMR or MS permitted to explore the reaction mechanism and to examine some aspects of the structure/activity relationships for the molecules of the same chemical family.","pmid":"15129733","doi":"10.1080/10715760310001659404","url":"https://pubmed.ncbi.nlm.nih.gov/15129733/"},{"id":2419,"title":"Epigallocatechin gallate markedly enhances formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine in the reaction of 2'-deoxyguanosine with hypochlorous acid.","authors":"Suzuki, Toshinori; Nakano, Toshiki; Masuda, Mitsuharu; Ohshima, Hiroshi","year":2004,"date":"2004 May 1","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"A tea polyphenol, (-)-epigallocatechin gallate (EGCG), which can scavenge a variety of reactive oxygen species, enhances the yield of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) up to 20-fold in the reaction of 2'-deoxyguanosine with hypochlorous acid (HOCl), compared with the reaction without EGCG. Certain concentrations of EGCG inhibited HOCl-mediated oxidation of 2'-deoxyguanosine to 8-oxo-dG to a limited extent, but efficiently inhibited further oxidation of 8-oxo-dG to spiroiminodihydantoin nucleoside, resulting in the accumulation of 8-oxo-dG in the reaction mixture. Conversely, EGCG inhibited dose-dependently an increase in 8-oxo-dG levels in calf thymus DNA incubated with HOCl. However, addition of HOCl to the DNA preoxidized with an oxidant-generating system (CuCl2, ascorbate, H2O2), led to the extensive loss of 8-oxo-dG due to its further oxidation. EGCG effectively inhibited this HOCl-mediated loss of 8-oxo-dG in the oxidized DNA, resulting in an apparent increase in 8-oxo-dG levels in the oxidized DNA, compared with the levels found without EGCG. The conversion of 8-oxo-dG into other oxidized lesions will inevitably affect recognition by DNA repair enzymes as well as the rates of mutations and DNA synthesis. Thus, our results suggest that as a biomarker of oxidative DNA damage, not only 8-oxo-dG but also the products of its further oxidation should be analyzed.","pmid":"15082062","doi":"10.1016/j.freeradbiomed.2004.02.004","url":"https://pubmed.ncbi.nlm.nih.gov/15082062/"},{"id":2426,"title":"Evaluation of products upon the reaction of hypohalous acid with unsaturated phosphatidylcholines.","authors":"Spalteholz, Holger; Wenske, Kathrin; Panasenko, Oleg M; Schiller, Jürgen; Arnhold, Jürgen","year":2004,"date":"2004 Apr","journal":"Chemistry and physics of lipids","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Myeloperoxidase released from stimulated neutrophils is able to produce hypochlorous and hypobromous acids. The composition of the reaction products of the interaction of hypohalous acid with double bonds of phosphatidylcholines was analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry using reagents enriched in 16O, 18O, 35Cl, 37Cl, 79Br, or 81Br. Two different types of products were assigned according to the mass spectra. First, chlorohydrins as well as bromohydrins were formed whereby the oxygen introduced was derived from water as shown by using H2 16O or H2 18O. In the second product a hydrogen atom was replaced by a halogen. This was clearly evidenced by different mass shifts using chlorine or bromine isotopes and the lack of any effects by oxygen isotopes. These results are consistent with the view that two principal possibilities of stabilisation of pi-complexes formed after binding of Cl(+) or Br(+) to the pi-system of the double bond exist.","pmid":"14998730","doi":"10.1016/j.chemphyslip.2003.12.005","url":"https://pubmed.ncbi.nlm.nih.gov/14998730/"},{"id":2429,"title":"Morphological and physiological changes of Staphylococcus aureus exposed to hypochlorous acid.","authors":"Abid, N; Maalej, S; Rouis, S","year":2004,"date":"2004","journal":"Letters in applied microbiology","category":"Materials & industrial applications","evidence":"Journal article / other","relevance":"Medium","abstract":"AIMS: To characterize hypochlorous acid (HOCl) stress resistance of Staphylococcus aureus and to assess physiological state and changes in cell morphology. METHODS AND RESULTS: Clinical wild-type strain of S. aureus was used in the stress with HOCl at concentrations ranging from 0 to 4 mg l(-1). Concentrations below 1.5 mg l(-1) caused no significant drop in viability. During 2 h of HOCl stress at 2 mg l(-1), there was appearance of minicells capable of passing through the 0.45 microm pores of filtration membranes. Intracellular proteins increased gradually to reach a level of 51% of dry weight and an enhanced synthesis of at least two proteins of 23 and 220 kDa was concluded. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: Staphylococcus aureus can undergo morphological and physiological changes during 2 h of exposure to 2 mg l(-1) of HOCl, which represents an adaptative response towards the hypochlorous acid stress. This evolution limits the use of 0.45 microm pores size membrane filters for research on S. aureus in waters and the clinical environment.","pmid":"14962048","doi":"10.1111/j.1472-765x.2004.01482.x","url":"https://pubmed.ncbi.nlm.nih.gov/14962048/"},{"id":2430,"title":"Minimizing prion risk without compromising the microbial composition of biofilms grown in vivo in a human plaque model.","authors":"Watson, P S; Sissons, C H; Devine, D A; Shore, R C; Kirkham, J; Nattress, B R; Marsh, P D; Robinson, C","year":2004,"date":"2004","journal":"Letters in applied microbiology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"AIMS: To determine whether the stringency of sterilization procedures for biological components of in vivo dental plaque-generating devices based on enamel can be increased to minimize prion risk without compromising natural biofilm composition. METHODS AND RESULTS: The composition of in vitro biofilms, grown on hypochlorite-treated and untreated autoclaved enamel surfaces, was determined using culture-based methods and checkerboard DNA: DNA hybridization analysis. No differences were found between biofilms recovered from either substrate. SIGNIFICANCE: Several in situ models allow generation of plaque in the oral cavity, followed by recovery of intact biofilms for experimentation. Approaches allowing plaque formation on natural tooth surfaces are most valuable, but present a possible infection risk to volunteers wearing plaque-collecting devices, particularly with respect to prions. Hypochlorite treatment of biological material, as an adjunct to autoclaving, reduces infection risk without compromising biofilm composition and should be adopted in all future studies using plaque-generating devices incorporating enamel, where there is a potential prion threat, and further investigated in other biological hard tissues.","pmid":"14962042","doi":"10.1111/j.1472-765x.2003.01477.x","url":"https://pubmed.ncbi.nlm.nih.gov/14962042/"},{"id":2431,"title":"HOCl-mediated cell death and metabolic dysfunction in the yeast Saccharomyces cerevisiae.","authors":"King, David A; Hannum, Diane M; Qi, Jian-Shen; Hurst, James K","year":2004,"date":"2004 Mar 1","journal":"Archives of biochemistry and biophysics","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"The nature of oxidative damage to Saccharomyces cerevisiae caused by levels of HOCl that inhibit cell replication was explored with the intent of identifying the loci of lethal lesions. Functions of cytosolic enzymes and organelles that are highly sensitive to inactivation by HOCl, including aldolase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and the mitochondrion, were only marginally affected by exposure of the yeast to levels of HOCl that completely inhibited colony formation. Loss of function in membrane-localized proteins, including the hexose transporters and PMA1 H(+)-ATPase, which is the primary proton pump located within the S. cerevisiae plasma membrane, was also marginal and K(+) leak rates to the extracellular medium increased only slowly with exposure to increasing amounts of HOCl, indicating that the plasma membrane retained its intrinsic impermeability to ions and metabolites. Adenylate phosphorylation levels in fermenting yeast declined in parallel with viability; however, yeast grown on respiratory substrates maintained near-normal phosphorylation levels at HOCl doses several-fold greater than that required for killing. This overall pattern of cellular response to HOCl differs markedly from that previously reported for bacteria, which appear to be killed by inhibition of plasma membrane proteins involved in energy transduction. The absence of significant loss of function in critical oxidant-sensitive cellular components and retention of ATP-synthesizing capabilities in respiring yeast cells exposed to lethal levels of HOCl suggests that toxicity in this case may arise by programmed cell death.","pmid":"14871479","doi":"10.1016/j.abb.2003.12.012","url":"https://pubmed.ncbi.nlm.nih.gov/14871479/"},{"id":2434,"title":"Antibacterial titanium plate anodized by being discharged in NaCl solution exhibits cell compatibility.","authors":"Shibata, Y; Kawai, H; Yamamoto, H; Igarashi, T; Miyazaki, T","year":2004,"date":"2004 Feb","journal":"Journal of dental research","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Implant surfaces should be modified to achieve excellent cell compatibility as well as antibacterial activity. Our previous study demonstrated that titanium plates anodized by being discharged in NaCl (Ti-Cl) exhibited high antibacterial activity. Since Ti-Cl was prepared with a NaCl solution, we hypothesized that Ti-Cl would exhibit low toxicity toward cells. The aims of this study were to characterize the surface of Ti-Cl and investigate the cell compatibility (MC3T3-E1 and L929 cells) of Ti-Cl. The results demonstrated that, since the TiCl(3) formed on the Ti-Cl surface was hydrolyzed into HCl, HClO, and TiOH after immersion in pure distilled water, TiCl(3) contributed to the antibacterial activity of Ti-Cl. On the other hand, TiO formed on the Ti-Cl surface enhanced cell extension and cell growth through a larger adsorption of fibronectin compared with the pure titanium control. These findings suggest that antibacterial titanium is a promising material for use in dental implant systems.","pmid":"14742647","doi":"10.1177/154405910408300206","url":"https://pubmed.ncbi.nlm.nih.gov/14742647/"},{"id":2438,"title":"Degradation of isoxaflutole (balance) herbicide by hypochlorite in tap water.","authors":"Lin, Chung-Ho; Lerch, Robert N; Garrett, Harold E; George, Milon F","year":2003,"date":"2003 Dec 31","journal":"Journal of agricultural and food chemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Chlorine has been widely employed for the disinfection of drinking water. Additionally, it has the capacity to oxidize many organic compounds in water. Isoxaflutole (Balance; IXF) belongs to a new class of isoxazole herbicides. Isoxaflutole has a very short soil half-life and rapidly degrades to a stable and phytotoxic metabolite, diketonitrile (DKN). Further degradation of DKN produces a nonbiologically active benzoic acid (BA) metabolite. In experiments using high-performance liquid chromatography-UV spectroscopy (HPLC-UV) and HPLC tandem mass spectrometry (HPLC-MS/MS), DKN was found to rapidly react with hypochlorite in tap water, yielding the BA metabolite as the major end product. One milligram per liter (19 microM) of hypochlorite residue in tap water was able to completely oxidize up to 1600 microg/L (4.45 micromol/L) of DKN. In tap water, the disappearance of IXF was much more rapid than in DI water. As soon as the IXF is hydrolyzed to DKN, the DKN quickly reacts with the OCl(-) to form nonphytotoxic BA. As a result, the herbicide solutions prepared with tap water at 500 microg/L will no longer possess any herbicidal activity after 48 h of storage. However, in agronomic settings, highly concentrated tank solutions (600-800 mg/L) may be prepared with tap water since the conversion of IXF to BA would represent <5% of the herbicide; therefore, any impact on the herbicide efficacy would be negligible. Results of this study show that current chlorination disinfection protocols in municipal water systems would completely eliminate the phytotoxic form of this new herbicide, DKN, from drinking water supplies; yet, farmers can use chlorinated tap water without significant loss of efficacy.","pmid":"14690388","doi":"10.1021/jf034473b","url":"https://pubmed.ncbi.nlm.nih.gov/14690388/"},{"id":2439,"title":"Hypochlorite action on plasma fibronectin promotes its extended conformation in complexes with antibodies.","authors":"Olszowski, Slawomir; Olszowska, Ewa; Kusior, Dorota; Piwowarczyk, Miroslaw; Stelmaszynska, Teresa","year":2003,"date":"2003 Jul","journal":"Journal of protein chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"We investigated the influence of hypochlorite (HOCl/OCl-) on plasma fibronectin (Fn) aggregation and examined an affinity of Fn aggregates to Fn specific antibodies. Human plasma Fn HOCl/OCl(-)-mediated modification was monitored with differential OD method and with measurements of tryptophan fluorescence followed by acrylamide quenching of tryptophan emission. Antibody fibronectin complex formation was examined in ELISA systems with chemiluminescence (CL) detection. Results were expressed as an average of three experiments performed in triplicate. Fn aggregation/fragmentation was monitored with dynamic light scattering method. It was showed that HOCl/OCl- mediated chlorination promotes Fn aggregation/fragmentation with concomitant oxidation of tryptophan moieties and dichlorotyrosine formation. Quenching experiments revealed that in chlorinated Fn the percentage of intact tryptophan moieties buried in the hydrophobic Fn core increases as compared to unchlorinated Fn. In general, ELISA experiments showed that chlorination of plasma Fn diminished the number of available epitopes but for lower HOCl/OCl- concentrations (1-2 mM) the reverse effect is observed--the number of accessible fibronectin epitopes is increased when Fn adopts extended conformation in complex with antibody. Our results suggest that HOCl/OCl(-)-mediated plasma Fn chlorination leads to the formation of soluble aggregates and is followed by refolding processes. Fn chlorination with low doses of HOCl/OCl- promotes extended Fn conformation which in turn increases affinity toward specific antibodies and may promote Fn-IgG cluster formation. Thus it seems possible that mildly chlorinated plasma Fn promotes formation of IgG clusters which in turn may activate neutrophils.","pmid":"14690247","doi":"10.1023/b:jopc.0000005460.94172.1d","url":"https://pubmed.ncbi.nlm.nih.gov/14690247/"},{"id":2445,"title":"Lysine residues direct the chlorination of tyrosines in YXXK motifs of apolipoprotein A-I when hypochlorous acid oxidizes high density lipoprotein.","authors":"Bergt, Constanze; Fu, Xiaoyun; Huq, Nabiha P; Kao, Jeff; Heinecke, Jay W","year":2004,"date":"2004 Feb 27","journal":"The Journal of biological chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Oxidized lipoproteins may play an important role in the pathogenesis of atherosclerosis. Elevated levels of 3-chlorotyrosine, a specific end product of the reaction between hypochlorous acid (HOCl) and tyrosine residues of proteins, have been detected in atherosclerotic tissue. Thus, HOCl generated by the phagocyte enzyme myeloperoxidase represents one pathway for protein oxidation in humans. One important target of the myeloperoxidase pathway may be high density lipoprotein (HDL), which mobilizes cholesterol from artery wall cells. To determine whether activated phagocytes preferentially chlorinate specific sites in HDL, we used tandem mass spectrometry (MS/MS) to analyze apolipoprotein A-I that had been oxidized by HOCl. The major site of chlorination was a single tyrosine residue located in one of the protein's YXXK motifs (where X represents a nonreactive amino acid). To investigate the mechanism of chlorination, we exposed synthetic peptides to HOCl. The peptides encompassed the amino acid sequences YKXXY, YXXKY, or YXXXY. MS/MS analysis demonstrated that chlorination of tyrosine in the peptides that contained lysine was regioselective and occurred in high yield if the substrate was KXXY or YXXK. NMR and MS analyses revealed that the N(epsilon) amino group of lysine was initially chlorinated, which suggests that chloramine formation is the first step in tyrosine chlorination. Molecular modeling of the YXXK motif in apolipoprotein A-I demonstrated that these tyrosine and lysine residues are adjacent on the same face of an amphipathic alpha-helix. Our observations suggest that HOCl selectively targets tyrosine residues that are suitably juxtaposed to primary amino groups in proteins. This mechanism might enable phagocytes to efficiently damage proteins when they destroy microbial proteins during infection or damage host tissue during inflammation.","pmid":"14660678","doi":"10.1074/jbc.M309046200","url":"https://pubmed.ncbi.nlm.nih.gov/14660678/"},{"id":2450,"title":"Interaction of myeloperoxidase with vascular NAD(P)H oxidase-derived reactive oxygen species in vasculature: implications for vascular diseases.","authors":"Zhang, Chunxiang; Yang, Jian; Jacobs, Jonathan D; Jennings, Lisa K","year":2003,"date":"2003 Dec","journal":"American journal of physiology. Heart and circulatory physiology","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Vascular NAD(P)H oxidase-derived reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) have emerged as important molecules in the pathogenesis of atherosclerosis, hypertension, and diabetic vascular complications. Additionally, myeloperoxidase (MPO), a transcytosable heme protein that is derived from leukocytes, is also believed to play important roles in the above-mentioned inflammatory vascular diseases. Previous studies have shown that MPO-induced vascular injury responses are H2O2 dependent. It is well known that MPO can use leukocyte-derived H2O2; however, it is unknown whether the vascular-bound MPO can use vascular nonleukocyte oxidase-derived H2O2 to induce vascular injury. In the present study, ANG II was used to stimulate vascular NAD(P)H oxidases and increase their H2O2 production in the vascular wall, and vascular dysfunction was used as the vascular injury parameter. We demonstrated that vascular-bound MPO has sustained activity in the vasculature. MPO could use the vascular NAD(P)H oxidase-derived H2O2 to produce hypochlorus acid (HOCl) and its chlorinating species. More importantly, MPO derived HOCl and chlorinating species amplified the H2O2-induced vascular injury by additional impairment of endothelium-dependent relaxation. HOCl-modified low-density lipoprotein protein (LDL), a specific biomarker for the MPO-HOCl-chlorinating species pathway, was expressed in LDL and MPO-bound vessels with vascular NAD(P)H oxidase-derived H2O2. MPO-vascular NAD(P)H oxidase-HOCl-chlorinating species may represent a common pathogenic pathway in vascular diseases and a new mechanism involved in exacerbation of vascular diseases under inflammatory conditions.","pmid":"14613914","doi":"10.1152/ajpheart.00435.2003","url":"https://pubmed.ncbi.nlm.nih.gov/14613914/"},{"id":2452,"title":"Histamine chloramine reactivity with thiol compounds, ascorbate, and methionine and with intracellular glutathione.","authors":"Peskin, Alexander V; Winterbourn, Christine C","year":2003,"date":"2003 Nov 15","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Histamine is stored in granules of mast cells and basophils and released by inflammatory mediators. It has the potential to intercept some of the HOCl generated by the neutrophil enzyme, myeloperoxidase, to produce histamine chloramine. We have measured rate constants for reactions of histamine chloramine with methionine, ascorbate, and GSH at pH 7.4, of 91 M(-1)s(-1), 195 M(-1)s(-1), and 721 M(-1)s(-1), respectively. With low molecular weight thiols, the reaction was with the thiolate and rates increased exponentially with decreasing thiol group pK(a). Comparing rate constants for different chloramines reacting with ascorbate or a particular thiol anion, these were higher when there was less negative charge in the vicinity of the chloramine group. Histamine chloramine was the most reactive among biologically relevant chloramines. Consumption of histamine chloramine and oxidation of intracellular GSH were examined for human fibroblasts. At nontoxic doses, GSH loss over 10 min was slightly greater than that with HOCl, but the cellular uptake of histamine chloramine was 5-10-fold less. With histamine chloramine, GSSG was a minor product and most of the GSH was converted to mixed disulfides with proteins. HOCl gave a different profile of GSH oxidation products, with significantly less GSSG and mixed disulfide formation. There was irreversible oxidation and losses to the medium, as observed with HOCl and other cell types. Thus, histamine chloramine shows high preference for thiols both in isolation and in cells, and in this respect is more selective than HOCl.","pmid":"14607524","doi":"10.1016/s0891-5849(03)00502-1","url":"https://pubmed.ncbi.nlm.nih.gov/14607524/"},{"id":2454,"title":"Effects of acetylcysteine and migration of resident eosinophils in an in vitro model of mucosal injury and restitution in equine right dorsal colon.","authors":"Rötting, Anna K; Freeman, David E; Eurell, Jo Ann C; Constable, Peter D; Wallig, Matthew","year":2003,"date":"2003 Oct","journal":"American journal of veterinary research","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVES: To evaluate the in vitro protective effects of acetylcysteine and response of resident mucosal eosinophils in oxidant-induced injury to tissues of right dorsal colon of horses. ANIMALS: 9 adult horses. PROCEDURE: Gastrointestinal mucosa was damaged in vitro with 3 mM hypochlorous acid (HOCl), with and without prior exposure to 6mM acetylcysteine. Control tissues were not exposed to HOCl or acetylcysteine. Control and damaged tissues were incubated in Krebs-Ringer-bicarbonate solution and tissue resistance measured during 240 minutes. Tissue permeability to radiolabeled mannitol was also used to assess mucosal barrier integrity. Tissues were examined by light microscopy before and after HOCl exposure and during and after incubation. RESULTS: Exposure to HOCl caused tissue damage and decreased tissue resistance. Restitution did occur during the incubation period. Eosinophils were located near the muscularis mucosae in freshly harvested tissues and migrated towards the luminal surface in response to HOCl-induced injury. Compared with tissues treated with HOCl without acetylcysteine, pretreatment with acetylcysteine prevented HOCl-induced tissue damage, changes in resistance, and histologically detectable eosinophil migration. The permeability to mannitol increased to the same extent in tissues treated with HOCl alone or with acetylcysteine and HOCl. CONCLUSIONS AND CLINICAL RELEVANCE: Eosinophils migrated toward the mucosal surface in equine colon in response to oxidant-induced damage in vitro. This novel finding could be relevant to inflammation in equine colon and a pathophysiologic feature of many colonic diseases. Acetylcysteine protected the mucosa against oxidant-induced injury and may be useful as a treatment option for various gastrointestinal tract disorders in horses.","pmid":"14596455","doi":"10.2460/ajvr.2003.64.1205","url":"https://pubmed.ncbi.nlm.nih.gov/14596455/"},{"id":2455,"title":"Human phagocytic cell responses to Scedosporium apiospermum (Pseudallescheria boydii): variable susceptibility to oxidative injury.","authors":"Gil-Lamaignere, Cristina; Roilides, Emmanuel; Lyman, Caron A; Simitsopoulou, Maria; Stergiopoulou, Theodouli; Maloukou, Avgi; Walsh, Thomas J","year":2003,"date":"2003 Nov","journal":"Infection and immunity","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Scedosporium apiospermum (Pseudallescheria boydii) is an emerging opportunistic filamentous fungus that causes serious infections in both immunocompetent and immunocompromised patients. To gain insight into the immunopathogenesis of infections due to S. apiospermum, the antifungal activities of human polymorphonuclear leukocytes (PMNs), mononuclear leukocytes (MNCs), and monocyte-derived macrophages (MDMs) against two clinical isolates of S. apiospermum were evaluated. Isolate SA54A was amphotericin B resistant and was the cause of a fatal disseminated infection. Isolate SA1216 (cultured from a successfully treated localized subcutaneous infection) was susceptible to amphotericin B. MDMs exhibited similar phagocytic activities against conidia of both isolates. However, PMNs and MNCs responded differently to the hyphae of these two isolates. Serum opsonization of hyphae resulted in a higher level of superoxide anion (O(2)(-)) release by PMNs in response to SA54A (amphotericin B resistant) than that seen in response to SA1216 (amphotericin B susceptible; P < 0.001). Despite this increased O(2)(-) production, PMNs and MNCs induced less hyphal damage to SA54A than to SA1216 (P < 0.001). To investigate the potential mechanisms responsible for these differences, hyphal damage was evaluated in the presence of antifungal oxidative metabolites as well as in the presence of a series of inhibitors and scavengers of antifungal PMN function. Mannose, catalase, superoxide dismutase, dimethyl sulfoxide, and heparin had no effect on PMN-induced hyphal damage to either of the two isolates. However, azide, which inhibits PMN myeloperoxidase activity, significantly reduced hyphal damage to SA1216 (P < 0.01) but not to SA54A. Hyphae of SA1216 were slightly more susceptible to oxidative pathway products, particularly HOCl, than those of SA54A. Thus, S. apiospermum is susceptible to antifungal phagocytic function to various degrees. The selective inhibitory pattern of azide with respect to hyphal damage and the parallel susceptibility to HOCl suggests an important difference in susceptibilities to myeloperoxidase products that may be related to the various levels of pathogenicity and amphotericin B resistance of S. apiospermum.","pmid":"14573669","doi":"10.1128/IAI.71.11.6472-6478.2003","url":"https://pubmed.ncbi.nlm.nih.gov/14573669/"},{"id":2458,"title":"In vitro inhibition of human neutrophil histotoxicity by ambroxol: evidence for a multistep mechanism.","authors":"Ottonello, Luciano; Arduino, Nicoletta; Bertolotto, Maria; Dapino, Patrizia; Mancini, Marina; Dallegri, Franco","year":2003,"date":"2003 Oct","journal":"British journal of pharmacology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Neutrophils are major culprits for the protease/antiprotease imbalance during various lung diseases, that is, chronic obstructive pulmonary disease, cystic fibrosis, idiopathic pulmonary fibrosis and adult respiratory distress syndrome. Thus, these cells are presently considered an ideal target for the pharmacologic control of tissue injury during these diseases. This study was planned in order to investigate if ambroxol and its precursor bromhexine are actually capable of preventing alpha-1-antitrypsin (A1AT) inactivation by stimulated neutrophils and possibly to look into the mechanisms underlying this event. Ambroxol inhibited the production of superoxide anion by activated neutrophils, whereas bromhexine had no inhibitory effect. Ambroxol decreased the production of hypochlorous acid (HOCl) from activated neutrophils with high efficiency, whereas bromhexine had a modest activity. Ambroxol and bromhexine were capable of limiting the chlorination of monochlorodimedon by HOCl, displaying the capacity of directly scavenging the oxidant. Ambroxol decreased the release of elastase and myeloperoxidase from activated neutrophils, whereas bromhexine was ineffective. Ambroxol prevented the A1AT inactivation by neutrophils, whereas bromhexine was completely ineffective. Among drugs currently available for in vivo use in humans, ambroxol is unique by virtue of its ability to prevent neutrophil-mediated A1AT inactivation via inhibition of HOCl production as well as HOCl scavenging. Also taking into account its capacity for curbing elastase release, the drug displays the potential to lessen the burden of oxidants/proteases and to increase the antiprotease shield at the site of inflammation. Thus, ambroxol appears to be a good candidate for raising attempts to develop new therapeutic histoprotective approaches to inflammatory bronchopulmonary diseases.","pmid":"14534155","doi":"10.1038/sj.bjp.0705497","url":"https://pubmed.ncbi.nlm.nih.gov/14534155/"},{"id":2463,"title":"Growth of Escherichia coli in model distribution system biofilms exposed to hypochlorous acid or monochloramine.","authors":"Williams, Margaret M; Braun-Howland, Ellen B","year":2003,"date":"2003 Sep","journal":"Applied and environmental microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Bacteria indigenous to water distribution systems were used to grow multispecies biofilms within continuous-flow slide chambers. Six flow chambers were also inoculated with an Escherichia coli isolate obtained from potable water. The effect of disinfectants on bacterial populations was determined after exposure of established biofilms to 1 ppm of hypochlorous acid (ClOH) for 67 min or 4 ppm of monochloramine (NH(2)Cl) for 155 min. To test the ability of bacterial populations to initiate biofilm formation in the presence of disinfectants, we assessed the biofilms after 2 weeks of exposure to residual concentrations of 0.2 ppm of ClOH or 4 ppm of NH(2)Cl. Lastly, to determine the effect of recommended residual concentrations on newly established biofilms, we treated systems with 0.2 ppm of ClOH after 5 days of growth in the absence of disinfectant. Whole-cell in situ hybridizations using fluorescently tagged, 16S rRNA-targeted oligonucleotide probes performed on cryosectioned biofilms permitted the direct observation of metabolically active bacterial populations, including certain phylogenetic groups and species. The results of these studies confirmed the resistance of established bacterial biofilms to treatment with recommended levels of disinfectants. Specifically, Legionella pneumophila, E. coli, and beta and delta proteobacteria were identified within biofilms both before and after treatment. Furthermore, although it was undetected using routine monitoring techniques, the observation of rRNA-containing E. coli within biofilms demonstrated not only survival but also metabolic activity of this organism within the model distribution systems. The persistence of diverse bacterial species within disinfectant-treated biofilms suggests that current testing practices underestimate the risk to immunocompromised individuals of contracting waterborne disease.","pmid":"12957935","doi":"10.1128/AEM.69.9.5463-5471.2003","url":"https://pubmed.ncbi.nlm.nih.gov/12957935/"},{"id":2465,"title":"MCLA-dependent chemiluminescence suggests that singlet oxygen plays a pivotal role in myeloperoxidase-catalysed bactericidal action in neutrophil phagosomes.","authors":"Arisawa, Fumio; Tatsuzawa, Hidetaka; Kambayashi, Yasuhiro; Kuwano, Hiroyuki; Fujimori, Ken; Nakano, Minoru","year":2003,"date":"2003 Jul-Aug","journal":"Luminescence : the journal of biological and chemical luminescence","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Bacteria ingested by a neutrophil are located in phagosomes in which H(2)O(2) is produced through the NADPH oxidase-dependent respiratory burst. Myeloperoxidase (MPO) plays important role in the bactericidal action of phagosomes. MPO catalyses the reaction of H(2)O(2) and Cl(-) to produce HClO. The chemical mechanism behind the bactericidal action of the MPO-H(2)O(2)-Cl(-) system is unclear. Bactericidal action may result from (a) the direct reactions of HOCl with biological components (through amine chlorination) or (b) (1)O(2), formed non-enzymatically from HOCl and H(2)O(2), that mainly works to kill microorganisms through bacterial respiratory chain injury. To answer this question, we developed a Cypridina luciferin analogue (MCLA)-dependent chemiluminescence method to determine the rate of formation of (1)O(2) from a (1)O(2) source at pH 4.5-9.0. Using the MCLA-dependent chemiluminescence method, we found that the rate of formation of (1)O(2) from the MPO-H(2)O(2)-Cl(-) system peaked at pH 7.0. Segal et al. (28) reported that almost all Staphylococcus aureus is killed 2 min after phagocytosis by neutrophils where the phagosomal pH is 7.4-7.75. However, amine chlorination by HOCl did not proceed at pH > 7.0. Moreover, the bactericidal activities of the MPO-H(2)O(2)-Cl(-) system with Escherichia coli at pH 4.5 and 8.0 were paralleled by the rate of formation of (1)O(2). Combining these observations and the results reported by Segal et al., we concluded that (1)O(2) is a major chemical species in the killing of bacteria in neutrophil phagosomes.","pmid":"12950060","doi":"10.1002/bio.728","url":"https://pubmed.ncbi.nlm.nih.gov/12950060/"},{"id":2467,"title":"Fragmentation of extracellular matrix by hypochlorous acid.","authors":"Woods, Alan A; Davies, Michael J","year":2003,"date":"2003 Nov 15","journal":"The Biochemical journal","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The interaction of extracellular matrix with cells regulates their adhesion, migration and proliferation, and it is believed that damage to vascular matrix components is a factor in the development of atherosclerosis. Evidence has been provided for a role for the haem enzyme MPO (myeloperoxidase), released by activated monocytes (and possibly macrophages), in oxidative events within the artery wall. As MPO is released extracellularly, and is highly basic, it might be expected to associate with poly-anionic matrix components thereby localizing damage to these materials. In this study the reaction of the MPO-derived oxidant hypochlorous acid (HOCl) with extracellular matrix from vascular smooth muscle cells and healthy pig arteries has been examined. HOCl is rapidly consumed by such matrix samples, with the formation of matrix-derived chloramines or chloramides. The yield of these intermediates increases with HOCl dose. These materials undergo a time- and temperature-dependent decay, which parallels the release of sugar and protein components from the treated matrix, consistent with these species being important intermediates. Matrix damage is enhanced by species that increase chloramine/chloramide decomposition, with copper and iron ions being effective catalysts, and decreased by compounds which scavenge chloramines/chloramides, or species derived from them. The effect of such matrix modifications on cellular behaviour is poorly understood, though it is known that changes in matrix materials can have profound effects on cell adhesion, proliferation, growth and phenotype. The observed matrix modifications reported here may therefore modulate cellular behaviour in diseases such as atherosclerosis where MPO-derived oxidants are generated.","pmid":"12911330","doi":"10.1042/BJ20030715","url":"https://pubmed.ncbi.nlm.nih.gov/12911330/"},{"id":2469,"title":"Myeloperoxidase-derived hypochlorous acid antagonizes the oxidative stress-mediated activation of iron regulatory protein 1.","authors":"Mütze, Sebine; Hebling, Ulrike; Stremmel, Wolfgang; Wang, Jian; Arnhold, Jürgen; Pantopoulos, Kostas; Mueller, Sebastian","year":2003,"date":"2003 Oct 17","journal":"The Journal of biological chemistry","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCl) is a highly reactive product generated by the myeloperoxidase reaction during the oxidative burst of activated neutrophils, which is implicated in many bactericidal and cytotoxic responses. Recent evidence suggests that HOCl may also play a role in the modulation of redox sensitive signaling pathways. The short half-life of HOCl and the requirement for a continuous presence of H2O2 as a substrate for its myeloperoxidase-catalyzed generation make the study of HOCl-mediated responses very difficult. We describe here an enzymatic model consisting of glucose/glucose oxidase, catalase, and myeloperoxidase (GOX/CAT/MPO) that allows the controlled generation of both HOCl and H2O2 and thus, mimics the oxidative burst of activated neutrophils. By employing this model we show that HOCl prevents the H2O2-mediated activation of iron regulatory protein 1 (IRP1), a central post-transcriptional regulator of mammalian iron metabolism. Activated IRP1 binds to (R)iron-responsive elements\" (IREs) within the mRNAs encoding proteins of iron metabolism and thereby controls their translation or stability. The inhibitory effect of HOCl is not a result of a direct modification of IRP1 by this oxidant. Kinetics experiments provide evidence that HOCl intervenes with the signaling cascade, which results in the activation of IRP1. We further demonstrate that HOCl antagonizes the H2O2-mediated increase in the levels of transferrin receptor, which is a downstream target of IRP1. Our findings suggest that HOCl can modulate signaling pathways in a concerted action with H2O2. The GOX/CAT/MPO system provides a valuable tool for studying the regulatory function of HOCl.","pmid":"12888561","doi":"10.1074/jbc.M307159200","url":"https://pubmed.ncbi.nlm.nih.gov/12888561/"},{"id":2471,"title":"Reassessment of the microbicidal activity of reactive oxygen species and hypochlorous acid with reference to the phagocytic vacuole of the neutrophil granulocyte.","authors":"Reeves, Emer P; Nagl, Markus; Godovac-Zimmermann, Jasminca; Segal, Anthony W","year":2003,"date":"2003 Aug","journal":"Journal of medical microbiology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"During phagocytosis, neutrophils undergo a burst of respiration in which oxygen is reduced to superoxide (O(-)(2)), which dismutates to form H(2)O(2). Myeloperoxidase (MPO) is discharged from the cytoplasmic granules into the phagosome following particle ingestion. It is thought to utilize H(2)O(2) to oxidize halides, which then react with and kill ingested microbes. Recent studies have provided new information as to the concentration of O(-)(2) and proteins, and the pH, within the vacuole. This study was conducted to examine the antimicrobial effect of O(-)(2), H(2)O(2) and hypochlorous acid under these conditions and it was found that the previously described bactericidal effect of these agents was reversed in the presence of granule proteins or MPO. To establish which cellular proteins were iodinated by MPO, cellular proteins and bacterial proteins, iodinated in neutrophils phagocytosing bacteria in the presence of (125)I, were separated by 2D gel electrophoresis. Iodinated spots were detected by autoradiography and the oxidized proteins were identified by MS. The targets of these iodination reactions were largely those of the host cell rather than those of the engulfed microbe.","pmid":"12867557","doi":"10.1099/jmm.0.05181-0","url":"https://pubmed.ncbi.nlm.nih.gov/12867557/"},{"id":2473,"title":"Collagen type II modification by hypochlorite.","authors":"Olszowski, Sławomir; Mak, Paweł; Olszowska, Ewa; Marcinkiewicz, Janusz","year":2003,"date":"2003","journal":"Acta biochimica Polonica","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Oxidation of proteins is a common phenomenon in the inflammatory process mediated by highly reactive agents such as hypochlorite (HOCl/OCl(-)) produced by activated neutrophils. For instance, in rheumatoid arthritis hypochlorite plays an important role in joint destruction. One of the major targets for HOCl/OCl(-) is collagen type II (CII) - the primary cartilage protein. In our study, HOCl/OCl(-) mediated collagen II modifications were tested using various methods: circular dichroism (CD), HPLC, ELISA, dynamic light scattering (DLS), fluorimetry and spectrophotometry. It was shown that hypochlorite action causes deamination with consecutive carbonyl group formation and transformation of tyrosine residues to dichlorotyrosine. Moreover, it was shown that ammonium chloramine (NH(2)Cl) formed in the reaction mixture reacts with CII. However, in this case the yield of carbonyl groups and dichlorotyrosine is lower than that observed for HOCl/OCl(-) by 50%. CD data revealed that collagen II exists as a random coil in the samples and that chlorination is followed by CII fragmentation. In the range of low HOCl/OCl(-) concentrations (up to 1 mM) 10-90 kDa peptides are predominant whereas massive production of shorter peptides was observed for high (5 mM) hypochlorite concentration. DLS measurements showed that chlorination with HOCl/OCl(-) decreases the radius of collagen II aggregates from 30 to 6.8 nm. Taking into account the fact that chlorinated collagen is partially degraded, the DLS results suggest that smaller micelles are formed of the 10-90 kDa peptide fraction. Moreover, collagen chlorination results in epitope modification which affects CII recognition by anti-CII antibodies. Finally, since in the synovial fluid the plausible hypochlorite concentration is smaller than that used in the model the change of size of molecular aggregates seems to be the best marker of hypochlorite-mediated collagen oxidation.","pmid":"12833171","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/12833171/"},{"id":2474,"title":"Comparison of the effect of detergent versus hypochlorite cleaning on environmental contamination and incidence of Clostridium difficile infection.","authors":"Wilcox, M H; Fawley, W N; Wigglesworth, N; Parnell, P; Verity, P; Freeman, J","year":2003,"date":"2003 Jun","journal":"The Journal of hospital infection","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"To determine how best to decontaminate the hospital environment of Clostridium difficile, we carried out a cross-over study on two elderly medicine wards to determine whether cleaning with a hypochlorite disinfectant was better than using neutral detergent in reducing the incidence of C. difficile infection (CDI). We examined 1128 environmental samples in two years, 35% of which grew C. difficile. There was a significant decrease of CDI incidence on ward X, from 8.9 to 5.3 cases per 100 admissions (P<0.05) using hypochlorite, but there was no significant effect on ward Y. On ward X the incidence of CDI was significantly associated with the proportion of culture-positive environmental sites (P<0.05). On ward Y the only significant correlation between CDI and C. difficile culture-positive environmental sites was in patient side-rooms (r=0.41, P<0.05). The total daily defined doses of cefotaxime, cephradine and aminopenicillins were similar throughout the trial. These results provide some evidence that use of hypochlorite for environmental cleaning may significantly reduce incidence of CDI, but emphasize the potential for confounding factors.","pmid":"12818583","doi":"10.1016/s0195-6701(02)00400-0","url":"https://pubmed.ncbi.nlm.nih.gov/12818583/"},{"id":2477,"title":"Mechanisms of killing of Bacillus subtilis spores by hypochlorite and chlorine dioxide.","authors":"Young, S B; Setlow, P","year":2003,"date":"2003","journal":"Journal of applied microbiology","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"AIMS: To determine the mechanisms of Bacillus subtilis spore killing by hypochlorite and chlorine dioxide, and its resistance against them. METHODS AND RESULTS: Spores of B. subtilis treated with hypochlorite or chlorine dioxide did not accumulate damage to their DNA, as spores with or without the two major DNA protective alpha/beta-type small, acid soluble spore proteins exhibited similar sensitivity to these chemicals; these agents also did not cause spore mutagenesis and their efficacy in spore killing was not increased by the absence of a major DNA repair pathway. Spore killing by these two chemicals was greatly increased if spores were first chemically decoated or if spores carried a mutation in a gene encoding a protein essential for assembly of many spore coat proteins. Spores prepared at a higher temperature were also much more resistant to these agents. Neither hypochlorite nor chlorine dioxide treatment caused release of the spore core's large depot of dipicolinic acid (DPA), but hypochlorite- and chlorine dioxide-treated spores much more readily released DPA upon a subsequent normally sub-lethal heat treatment than did untreated spores. Hypochlorite-killed spores could not initiate the germination process with either nutrients or a 1 : 1 chelate of Ca2+-DPA, and these spores could not be recovered by lysozyme treatment. Chlorine dioxide-treated spores also did not germinate with Ca2+-DPA and could not be recovered by lysozyme treatment, but did germinate with nutrients. However, while germinated chlorine dioxide-killed spores released DPA and degraded their peptidoglycan cortex, they did not initiate metabolism and many of these germinated spores were dead as determined by a viability stain that discriminates live cells from dead ones on the basis of their permeability properties. CONCLUSIONS: Hypochlorite and chlorine dioxide do not kill B. subtilis spores by DNA damage, and a major factor in spore resistance to these agents appears to be the spore coat. Spore killing by hypochlorite appears to render spores defective in germination, possibly because of severe damage to the spore's inner membrane. While chlorine dioxide-killed spores can undergo the initial steps in spore germination, these germinated spores can go no further in this process probably because of some type of membrane damage. SIGNIFICANCE AND IMPACT OF THE STUDY: These results provide information on the mechanisms of the killing of bacterial spores by hypochlorite and chlorine dioxide.","pmid":"12807454","doi":"10.1046/j.1365-2672.2003.01960.x","url":"https://pubmed.ncbi.nlm.nih.gov/12807454/"},{"id":2478,"title":"Biological and dietary antioxidants protect against DNA nitration induced by reaction of hypochlorous acid with nitrite.","authors":"Chen, Hauh-Jyun Candy; Wu, Shi-Bei; Chang, Chia-Ming","year":2003,"date":"2003 Jul 1","journal":"Archives of biochemistry and biophysics","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Nitryl chloride, formed by reaction of hypochlorous acid with nitrite, might contribute to nitrative damage of biomolecules in addition to peroxynitrite. Damage of DNA by these reactive nitrogen oxide species is implicated in carcinogenesis associated with chronic infections and inflammation. Nitrated DNA adducts, such as 8-nitroguanine and 8-nitroxanthine, are not stable in DNA since they undergo spontaneous depurination, leading to apurinic site formation. In this report, we investigate the protective effect of biological and dietary antioxidants in inhibiting DNA nitration induced by nitryl chloride. The effect of inhibition was evaluated by decrease of 8-nitroxanthine and 8-nitroguanine formation. Among the 21 compounds examined, dihydrolipoic acid is the most effective in preventing DNA nitration, followed by N-acetyl-L-cysteine and folic acid. For sulfur-containing compounds, the more highly reduced compounds are stronger inhibitors of DNA nitration. The major product of N-acetyl-L-cysteine reaction with nitryl chloride is characterized as the (R)-2-acetylamino-3-sulfopropionic acid, a physiologically irreversible product, suggesting that nitryl chloride is a strong oxidizing agent.","pmid":"12801519","doi":"10.1016/s0003-9861(03)00220-0","url":"https://pubmed.ncbi.nlm.nih.gov/12801519/"},{"id":2480,"title":"Oxidative degradation of indigocarmine by hypochlorite--a tool for determination of hypochlorite in commercial samples.","authors":"Harriram, A; Govender, V; Jonnalagadda, S B","year":2003,"date":"2003 Jun","journal":"Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The oxidative action of hypochlorite on indigocarmine is investigated. Hypochlorite dissociates indigocarmine to produce isatin-5-monosulphonic acid, with a stoichiometry of 2:1. The probable mechanism is proposed. The suitability of reaction between hypochlorite and indigocarmine as an indicator reaction for the determination of high levels of hypochlorite in synthetic and commercial samples is investigated. A simple and reliable kinetic-analytical method is developed for the determination of hypochlorite ion at alkaline pH, based on its oxidizing activity.","pmid":"12774908","doi":"10.1081/ese-120019863","url":"https://pubmed.ncbi.nlm.nih.gov/12774908/"},{"id":2482,"title":"Phagocytes produce 5-chlorouracil and 5-bromouracil, two mutagenic products of myeloperoxidase, in human inflammatory tissue.","authors":"Henderson, Jeffrey P; Byun, Jaeman; Takeshita, Junko; Heinecke, Jay W","year":2003,"date":"2003 Jun 27","journal":"The Journal of biological chemistry","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Oxidative damage to DNA has been implicated in carcinogenesis during chronic inflammation. Epidemiological and biochemical studies suggest that one potential mechanism involves myeloperoxidase, a hemeprotein secreted by human phagocytes. In this study, we demonstrate that human neutrophils use myeloperoxidase to oxidize uracil to 5-chlorouracil in vitro. Uracil chlorination by myeloperoxidase or reagent HOCl exhibited an unusual pH dependence, being minimal at pH approximately 5, but increasing markedly under either acidic or mildly basic conditions. This bimodal curve suggests that myeloperoxidase initially produces HOCl, which subsequently chlorinates uracil by acid- or base-catalyzed reactions. Human neutrophils use myeloperoxidase and H2O2 to chlorinate uracil, suggesting that nucleobase halogenation reactions may be physiologically relevant. Using a sensitive and specific mass spectrometric method, we detected two products of myeloperoxidase, 5-chlorouracil and 5-bromouracil, in neutrophil-rich human inflammatory tissue. Myeloperoxidase is the most likely source of 5-chlorouracil in vivo because halogenated uracil is a specific product of the myeloperoxidase system in vitro. In contrast, previous studies have demonstrated that 5-bromouracil could be generated by either eosinophil peroxidase or myeloperoxidase, which preferentially brominates uracil at plasma concentrations of halide and under moderately acidic conditions. These observations indicate that the myeloperoxidase system promotes nucleobase halogenation in vivo. Because 5-chlorouracil and 5-bromouracil can be incorporated into nuclear DNA, and these thymine analogs are well known mutagens, our observations raise the possibility that halogenation reactions initiated by phagocytes provide one pathway for mutagenesis and cytotoxicity at sites of inflammation.","pmid":"12707270","doi":"10.1074/jbc.M303928200","url":"https://pubmed.ncbi.nlm.nih.gov/12707270/"},{"id":2484,"title":"Effects of hypochlorite and hydrogen peroxide on cardiac autonomic receptors and vascular endothelial function.","authors":"Sand, Carsten; Peters, Stephan L M; Pfaffendorf, Martin; van Zwieten, Pieter A","year":2003,"date":"2003 Apr","journal":"Clinical and experimental pharmacology & physiology","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"1. Reactive oxygen species (ROS) are known to be involved in the progression of various cardiovascular diseases. One source of ROS is activated neutrophils, which can release superoxide anion radicals and hydrogen peroxide by membrane-bound NAD(P)H oxidases. These ROS not only destroy bacteria, but may also affect mammalian tissue. In addition, hydrogen peroxide serves as a substrate for myeloperoxidase, an enzyme that is released by activated neutrophils during inflammatory processes, as seen, for instance, in reperfusion injury and atherosclerosis. Myeloperoxidase catalyses the oxidation of chloride by hydrogen peroxide, yielding hypochlorite, an extremely potent oxidant. 2. The purpose of the present study was to evaluate the effects of hypochlorite on a variety of receptor-dependent processes in rat isolated left atria and rat thoracic aorta and to compare these results with the phenomena observed after incubation with hydrogen peroxide. 3. In the presence of hypochlorite (300 micro mol/L), the positive inotropic response of alpha1-adrenoceptor stimulation by methoxamine (300 micro mol/L) was converted into a negative inotropic response. In contrast, the positive inotropic effects of the beta1/beta2-adrenoceptor agonist isoprenaline (3 micro mol/L) and endothelin (ET)-1 (100 nmol/L) remained largely unaffected. 4. The inversion of alpha1-adrenoceptor-mediated inotropy was not obtained in the presence of hydrogen peroxide (500 micro mol/L). Hydrogen peroxide did not affect the positive inotropic response of isoprenaline, but it completely abolished the inotropic effect of ET-1. 5. The effect of cardiac M2-receptor stimulation was studied in the presence of hypochlorite and hydrogen peroxide. The negative inotropic response to acetylcholine (ACh) was significantly enhanced after hypochlorite incubation compared with control. 6. In the rat thoracic aorta, endothelial function, evaluated by means of ACh-induced vasodilation, was completely abolished in the presence of hypochlorite (100 micro mol/L), but remained unaffected by treatment with the same concentration of hydrogen peroxide. 7. From these data, we conclude that hypochlorite exerts more toxic properties than its precursor hydrogen peroxide, leading to substantial physiological alterations in cardiac and vascular tissue.","pmid":"12680842","doi":"10.1046/j.1440-1681.2003.03822.x","url":"https://pubmed.ncbi.nlm.nih.gov/12680842/"},{"id":2486,"title":"Inhibition of hypochlorous acid-induced oxidative reactions by nitrite: is nitrite an antioxidant?","authors":"Whiteman, Matthew; Rose, Peter; Halliwell, Barry","year":2003,"date":"2003 Apr 18","journal":"Biochemical and biophysical research communications","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Acute and chronic inflammation result in increased nitrogen monoxide (z.rad;NO) formation and the accumulation of nitrite (NO(2)(-)). Neutrophils stimulated by various inflammatory mediators release myeloperoxidase to produce the cytotoxic agent hypochlorous acid (HOCl). At physiologically attainable concentrations, we found that NO(2)(-) significantly inhibits HOCl-mediated DNA strand breakage and ascorbate depletion. HOCl-mediated inactivation of pure alpha(1)-antiproteinase or of the elastase inhibitory capacity of human plasma was inhibited by the addition of NO(2)(-). NO(2)(-) was more effective than ascorbate, GSH, and urate at inhibiting HOCl-mediated toxicity to human HepG2 cells in culture. These data suggest that NO(2)(-) may act in an antioxidant manner by removing HOCl at sites of inflammation where both HOCl and z.rad;NO are overproduced.","pmid":"12684065","doi":"10.1016/s0006-291x(03)00503-5","url":"https://pubmed.ncbi.nlm.nih.gov/12684065/"},{"id":2490,"title":"Transformation and activation of benzidine by oxidants of the inflammatory response.","authors":"Lakshmi, Vijaya M; Hsu, Fong Fu; Zenser, Terry V","year":2003,"date":"2003 Mar","journal":"Chemical research in toxicology","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Aromatic amines, such as benzidine (BZ), initiate bladder cancer in humans. Inflammation/infection play an important role in this cancer. This study was designed to assess the influence of inflammatory oxidants, including reactive nitrogen oxygen species (RNOS), on BZ transformation and activation. RNOS were generated under various conditions and reacted with BZ, and the products were examined by HPLC. Conditions that generate nitrogen dioxide radical, NO(2)(-) + myeloperoxidase + H(2)O(2) and ONOO(-), produced primarily a single new product, which was identified by MS as azobenzidine (AZO-BZ). The myeloperoxidase-catalyzed reaction was inhibited by 1 mM cyanide and did not require NO(2)(-). Chloride (100 mM) reduced the myeloperoxidase reaction by 30% with taurine having little effect. In contrast, conditions that generate N(2)O(3), i.e., NO donor diethylamine (DEA) NONOate, produced two products, which were identified by MS as 4'-OH-4-aminobiphenyl (4'-OH-ABP) and 4-aminobiphenyl (ABP). 2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, an oxidant of NO thought to produce NO(2)(*), had a biphasic effect on product formation. At a concentration equal to DEA NONOate, a 5-fold increase in BZ nitrosation was observed, while at higher concentrations nitrosation was greatly diminished and formation of AZO-BZ occurred. Glutathione prevented RNOS transformation of BZ. With MPO and ONOO(-), a new product was formed that cochromatographed with 3-(glutathione-S-yl)BZ. Glutathione also prevented nitrosation of BZ but did not form additional BZ products. HOCl-mediated activation of BZ, 4'-OH-ABP, and ABP to bind DNA was assessed. A higher level of binding was observed at pH 5.5 than pH 7.4. BZ elicited the most binding. More binding was observed at both pH values with 4'-OH-ABP than ABP. Thus, components of the inflammatory response are capable of BZ transformation and activation.","pmid":"12641437","doi":"10.1021/tx0200966","url":"https://pubmed.ncbi.nlm.nih.gov/12641437/"},{"id":2492,"title":"Efficacy of selected hand hygiene agents used to remove Bacillus atrophaeus (a surrogate of Bacillus anthracis) from contaminated hands.","authors":"Weber, David J; Sickbert-Bennett, Emily; Gergen, Maria F; Rutala, William A","year":2003,"date":"2003 Mar 12","journal":"JAMA","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"CONTEXT: The intentional use of Bacillus anthracis transmitted via the US mail in October-November 2001 resulted in 22 people developing inhalation or cutaneous anthrax. Glove use with handwashing prior to and after contact with potential contaminated environmental surfaces and cutaneous lesions has been recommended. However, only limited data are available on the susceptibility of B anthracis to antiseptics. OBJECTIVE: To evaluate the efficacy of several hand antiseptics (interventions) and soap and water (control) against Bacillus atrophaeus, a surrogate of B anthracis. DESIGN, SETTING, AND PARTICIPANTS: Challenge study conducted among healthy adult volunteers, using the Standard Test Method for Evaluation of the Effectiveness of Health Care Professional Handwash Formulations (American Society for Testing and Materials E 1174-94) to determine the efficacy of various hand hygiene products at wash times of 10, 30, and 60 seconds. Volunteers were excluded if they had eczema, psoriasis, or other chronic skin conditions; nonintact skin; or allergies to any study agent. Study agents were a waterless rub containing 61% ethyl alcohol, a 2% chlorhexidine gluconate preparation, and an antibacterial microfiber towel that releases hypochlorite. A nonantimicrobial soap was used as a control. MAIN OUTCOME MEASURE: Reduction of B atrophaeus spores (log10 CFU/mL) on contaminated hands. RESULTS: Washes of 10, 30, and 60 seconds with either soap and water or 2% chlorhexidine gluconate eliminated 1.5 to 2.0 log10 CFUs/mL of B atrophaeus spores at wash 3. Mean reductions (95% confidence intervals) with 10-, 30-, and 60-second washes with soap and water were 2.4 (2.2-2.5), 2.3 (2.2-2.4), and 2.1 (1.9-2.4) log(10) CFUs/mL, respectively; and with 2% chlorhexidine gluconate, 2.1 (2.0-2.3), 1.8 (1.5-2.0), and 1.7 (1.5-1.9) log10 CFUs/mL, respectively. Handwashing with chlorine-containing towels was increasingly effective as the wipe time increased; reductions at 10, 30, and 60 seconds were 1.3 (1.1-1.5), 1.6 (1.2-2.0), and 2.2 (2.1-2.2) log10 CFUs/mL, respectively. A waterless rub containing 61% ethyl alcohol was ineffective in eliminating B atrophaeus spores at all times tested (0 [-0.1 to 0.1], -0.2 [-0.3 to -0.1], and 0 [-0.2 to 0.2] log10 CFUs/mL). CONCLUSIONS: In this evaluation of hand hygiene agents, handwashing with soap and water, 2% chlorhexidine gluconate, or chlorine-containing towels reduced the amount of B atrophaeus spore contamination, whereas use of a waterless rub containing ethyl alcohol was not effective in removing spores.","pmid":"12633189","doi":"10.1001/jama.289.10.1274","url":"https://pubmed.ncbi.nlm.nih.gov/12633189/"},{"id":2495,"title":"The physiology and pharmacology of singlet oxygen.","authors":"Stief, Thomas W","year":2003,"date":"2003 Apr","journal":"Medical hypotheses","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Reactive oxygen species (ROS) are generated by many different cells. Singlet oxygen (1O(2)) and a reaction product of it, excited carbonyls (C=O*), are important ROS. 1O(2) and C=O* are nonradicalic and emit light (one photon/molecule) when returning to ground state oxygen. Especially activated polymorphonuclear neutrophil granulocytes (PMN) produce large amounts of 1O(2). Via activation of the respiratory burst (NADPH oxidase and myeloperoxidase) they synthesize hypochlorite (NaOCl) and chloramines (in particular N-chlorotaurine). Chloramines are selective and stable chemical generators of 1O(2). In the human organism, 1O(2) is both a signal and a weapon with therapeutic potency against very different pathogens, such as microbes, virus, cancer cells and thrombi. Chloramines at blood concentrations between 1 and 2 mmol/L inactivate lipid enveloped virus and chloramines at blood concentrations below 0.5 mmol/L, i.e. at oxidant concentrations that do not affect thrombocytes or hemostasis factors, act antithrombotically by activation of the physiologic PMN mediated fibrinolysis; this thrombolysis is of selective nature, i.e. it does not impair the hemostasis system of the patient allowing the antithrombotic treatment in patients where the current risky thrombolytic treatment is contraindicated. The action of 1O(2) might be compared to the signaling and destroying gunfire of soldiers directed against bandits at night, resulting in an autorecruitment of the physiological inflammatory response. Chloramines (such as the mild and untoxic oxidant chloramine T (N-chloro-p-toluene-sulfonamide)) and their signaling and destroying reaction product 1O(2) might be promising new therapeutic agents against a multitude of up to now refractory diseases.","pmid":"12615524","doi":"10.1016/s0306-9877(03)00026-4","url":"https://pubmed.ncbi.nlm.nih.gov/12615524/"},{"id":2497,"title":"Pulmonary surfactant protein-A (SP-A) restores the surface properties of surfactant after oxidation by a mechanism that requires the Cys6 interchain disulfide bond and the phospholipid binding domain.","authors":"Rodriguez Capote, Karina; McCormack, Francis X; Possmayer, Fred","year":2003,"date":"2003 Jun 6","journal":"The Journal of biological chemistry","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Reactive oxygen species produced by activated leuko-cytes in the alveolar epithelial lining fluid have been implicated in the inactivation of pulmonary surfactant and the impairment of lung function. Oxidation of bovine lipid extract surfactant (BLES), a therapeutic surfactant, with hypochlorous acid (H-BLES) or the Fenton reaction (F-BLES) led to temporary increases in conjugated dienes and formation of malondialdehyde and 4-hydroxy-2-nonenal. Electrospray ionization mass spectrometry revealed the appearance of lipid hydroperoxides, peroxides, lysophospholipids, and free fatty acids. Captive bubble tensiometer studies of H-BLES demonstrated prolonged adsorption times, film instability at low surface tensions during film compression, and reduced respreadability during film expansion. F-BLES exhibited prolonged adsorption times, a marked effect on increasing compressibility during compression, and a lesser effect on reducing respreadability on expansion. Addition of native bovine or rat surfactant-associated protein A (SP-A) reversed the effects of oxidation on surfactant biophysical properties. Studies using mutant recombinant rat SP-As indicated that an intact carbohydrate recognition domain and disulfide-dependent oligomeric assembly are critical for these effects, but the collagen-like region is not required. We conclude that SP-A can reverse the detrimental effects of surfactant oxidation on the biophysical properties of surfactant, by a mechanism that is dependent on interchain disulfide bond formation and the C-terminal domains of the protein.","pmid":"12600986","doi":"10.1074/jbc.M212697200","url":"https://pubmed.ncbi.nlm.nih.gov/12600986/"},{"id":2498,"title":"Oxidation of Cu, Zn-superoxide dismutase by the myeloperoxidase/hydrogen peroxide/chloride system: functional and structural effects.","authors":"Auchère, Françoise; Capeillère-Blandin, Chantal","year":2002,"date":"2002 Nov","journal":"Free radical research","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"This study investigated the functional and structural effects of bovine Cu, Zn-superoxide dismutase (Cu, Zn-SOD) oxidation by the myeloperoxidase (MPO)/hydrogen peroxide (H2O2)/chloride system and reagent hypochlorous acid (HOCl). Exposure to HOCl led to a fast inactivation accompanied by structural alterations. The residual SOD activity depended on the reactants concentration ratio and on the exposure time. The concomitant high consumption of HOCl indicated the presence of multiple targets on the protein. As assessed by SDS/PAGE, HOCl caused the dissociation of the protein into protomers at 16 kDa stable to both SDS and reducing conditions. Results from isoelectric focusing gels showed that exposure to HOCl induced the formation of modified protein derivatives, with a more acidic net electric charge than the parent molecule, consistent with the presence of additional ions observed in the electrospray ionization mass spectra. The reaction of protein with HOCl resulted in changes in protein conformation as assessed by the UV fluorescence and oxidation of the unique methionine and tyrosine, chlorination of several lysines with formation of chloramines. There was no significant formation of dityrosine and carbonyl groups. Exposure to high levels of HOCl resulted in complete enzyme inactivation, loss of additional lysine, histidine and arginine residues and coincident detection of weakly bound zinc and copper using 4-pyridylazaresorcinol. Collectively, the results suggest that the decrease of the dismutase activity is probably related to both dissociation into protomers and unfolding due to extensive oxidative modifications of amino acids.","pmid":"12592671","doi":"10.1080/1071576021000016454","url":"https://pubmed.ncbi.nlm.nih.gov/12592671/"},{"id":2503,"title":"Relative contributions of myeloperoxidase and NADPH-oxidase to the early host defense against pulmonary infections with Candida albicans and Aspergillus fumigatus.","authors":"Aratani, Y; Kura, F; Watanabe, H; Akagawa, H; Takano, Y; Suzuki, K; Dinauer, M C; Maeda, N; Koyama, H","year":2002,"date":"2002 Dec","journal":"Medical mycology","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Generation of oxidative products by phagocytic cells is known to be an important host defense mechanism directed toward killing of invading microorganisms. The importance of two major oxidant-producing enzymes, myeloperoxidase (MPO) and NADPH-oxidase, in in vivo fungicidal action was directly compared in genetically engineered mice. Both MPO-deficient (MPO-/-) and NADPH-oxidase-deficient (X-linked chronic granulomatous disease [X-CGD]) mice showed increased susceptibility to pulmonary infections with Candida albicans and Aspergillus fumigatus compared with normal mice, and the X-CGD mice exhibited shorter survivals than MPO-/- mice. This increased mortality of X-CGD mice was associated with a 10- to 100-fold increased outgrowth of the fungi in their organs during the first 6 days. These results suggest that superoxide (O2-) produced by NADPH-oxidase is more important than hypochlorous acid (HOCl) produced by MPO, although both oxidative products obviously contribute to the host defense against pulmonary infection with those fungi. We also observed that MPO-/-/X-CGD double knockout mice showed comparable levels of susceptibility to the X-CGD mice against C. albicans and A. funigatus, indicating that MPO is unable to play a role in host defense in the absence of NADPH-oxidase. This strongly suggests that hydrogen peroxide, the precursor of HOCl, is solely derived from O2- produced by NADPH-oxidase.","pmid":"12521119","doi":"10.1080/mmy.40.6.557.563","url":"https://pubmed.ncbi.nlm.nih.gov/12521119/"},{"id":2504,"title":"Capsid functions of inactivated human picornaviruses and feline calicivirus.","authors":"Nuanualsuwan, Suphachai; Cliver, Dean O","year":2003,"date":"2003 Jan","journal":"Applied and environmental microbiology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"The exceptional stability of enteric viruses probably resides in their capsids. The capsid functions of inactivated human picornaviruses and feline calicivirus (FCV) were determined. Viruses were inactivated by UV, hypochlorite, high temperature (72 degrees C), and physiological temperature (37 degrees C), all of which are pertinent to transmission via food and water. Poliovirus (PV) and hepatitis A virus (HAV) are transmissible via water and food, and FCV is the best available surrogate for the Norwalk-like viruses, which are leading causes of food-borne and waterborne disease in the United States. The capsids of all 37 degrees C-inactivated viruses still protected the viral RNA against RNase, even in the presence of proteinase K, which contrasted with findings with viruses inactivated at 72 degrees C. The loss of ability of the virus to attach to homologous cell receptors was universal, regardless of virus type and inactivation method, except for UV-inactivated HAV, and so virus inactivation was almost always accompanied by the loss of virus attachment. Inactivated HAV and FCV were captured by homologous antibodies. However, inactivated PV type 1 (PV-1) was not captured by homologous antibody and 37 degrees C-inactivated PV-1 was only partially captured. The epitopes on the capsids of HAV and FCV are evidently discrete from the receptor attachment sites, unlike those of PV-1. These findings indicate that the primary target of UV, hypochlorite, and 72 degrees C inactivation is the capsid and that the target of thermal inactivation (37 degrees C versus 72 degrees C) is temperature dependent.","pmid":"12514015","doi":"10.1128/AEM.69.1.350-357.2003","url":"https://pubmed.ncbi.nlm.nih.gov/12514015/"},{"id":2506,"title":"Biological reactivity and biomarkers of the neutrophil oxidant, hypochlorous acid.","authors":"Winterbourn, Christine C","year":2002,"date":"2002 Dec 27","journal":"Toxicology","category":"Food & agriculture","evidence":"Review","relevance":"High","abstract":"Free radicals or reactive oxygen species are thought to contribute to the pathology of many diseases. These include inflammatory conditions, where neutrophils accumulate in large numbers and are stimulated to produce superoxide and other reactive oxidants. Hypochlorous acid (HOCl), produced by myeloperoxidase-catalysed oxidation of chloride by hydrogen peroxide, is the major strong oxidant generated by these cells. Neutrophil-mediated injury may also be important in toxicology when an initial insult is followed by an inflammatory response. It is important to characterize the inflammatory component of such injury and the extent to which it involves reactive oxidants. On the one hand, this requires an understanding of how neutrophil oxidants react with cells and tissue constituents. On the other, specific biomarkers are needed so that oxidative damage can be quantified in clinical material and related to disease severity. This presentation considers biologically relevant reactions of HOCl and the biomarker assays that can be applied to probing the pathological role of myeloperoxidase and its products.","pmid":"12505315","doi":"10.1016/s0300-483x(02)00286-x","url":"https://pubmed.ncbi.nlm.nih.gov/12505315/"},{"id":2507,"title":"Inhibition of human surfactant protein A function by oxidation intermediates of nitrite.","authors":"Davis, Ian C; Zhu, Sha; Sampson, Jacinda B; Crow, John P; Matalon, Sadis","year":2002,"date":"2002 Dec 15","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"NitraNitration of protein tyrosine residues by peroxynitrite (ONOO - ) has been implicated in a variety of inflammatory diseases such as acute respiratory distress syndrome (ARDS). Pulmonary surfactant protein A (SP-A) has multiple functions including host defense. We report here that a mixture of hypochlorous acid (HOCl) and nitrite (NO 2 - ) induces nitration, oxidation, and chlorination of tyrosine residues in human SP-A and inhibits SP-A's ability to aggregate lipids and bind mannose. Nitration and oxidation of SP-A was not altered by the presence of lipids, suggesting that proteins are preferred targets in lipid-rich mixtures such as pulmonary surfactant. Moreover, both horseradish peroxidase and myeloperoxidase (MPO) can utilize NO 2 - and hydrogen peroxide (H 2 O 2 ) as substrates to catalyze tyrosine nitration in SP-A and inhibit its lipid aggregation function. SP-A nitration and oxidation by MPO is markedly enhanced in the presence of physiological concentrations of Cl - and the lipid aggregation function of SP-A is completely abolished. Collectively, our results suggest that MPO released by activated neutrophils during inflammation utilizes physiological or pathological levels of NO 2 - to nitrate proteins, and may provide an additional mechanism in addition to ONOO - formation, for tissue injury in ARDS and other inflammatory diseases associated with upregulated *NO and oxidant production.","pmid":"12488138","doi":"10.1016/s0891-5849(02)01170-x","url":"https://pubmed.ncbi.nlm.nih.gov/12488138/"},{"id":2508,"title":"Augmenting effect of acetic acid for acidification on bactericidal activity of hypochlorite solution.","authors":"Kuroiwa, K; Nakayama, H; Kuwahara, T; Tamagawa, K; Hattori, K; Murakami, K; Korai, H; Ohnishi, Y","year":2003,"date":"2003","journal":"Letters in applied microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"AIMS: Bactericidal activity of chlorine solution is enhanced by weak acidification. We compared the effects of various acids on the bactericidal activity of hypochlorite solution to establish a method for safe and effective use of an acidic hypochlorite solution. METHODS AND RESULTS: The bactericidal activities of acidic hypochlorite solutions that had been adjusted to pH 5.0 with hydrochloric acid, acetic acid, citric acid, lactic acid, formic acid, phosphoric acid or sulphuric acid against Bacillus subtilis spores were compared. The acidic solutions prepared with hydrochloric acid and acetic acid showed the highest bactericidal activity, and all of the spores (5 x 106 cfu ml(-1)) were killed within 10 min. On the other hand, the solutions prepared with citric acid and lactic acid showed no bactericidal activity against any bacterial strains tested in this study despite the low pH. The amount of chlorine gas produced by the preparation using acetic acid was sixfold less than that produced from the preparation using hydrochloric acid. CONCLUSIONS: Acetic acid is the most suitable and safe acid for the preparation of an acidic hypochlorite solution. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study provide useful information for establishing a method for safe and effective use of an acidic hypochlorite solution.","pmid":"12485341","doi":"10.1046/j.1472-765x.2003.01261.x","url":"https://pubmed.ncbi.nlm.nih.gov/12485341/"},{"id":2513,"title":"Pyrrolidine dithiocarbamate is a potent antioxidant against hypochlorous acid-induced protein damage.","authors":"Zhu, Ben-Zhan; Carr, Anitra C; Frei, Balz","year":2002,"date":"2002 Dec 4","journal":"FEBS letters","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The antioxidant potential of the dithiol compound pyrrolidine dithiocarbamate (PDTC) against protein damage induced by hypochlorous acid (HOCl) was investigated. The effects of PDTC were compared to those of reduced glutathione (GSH) and N-acetylcysteine (NAC). PDTC markedly and in a concentration-dependent manner inhibited HOCl-induced inactivation of alpha(1)-antiproteinase, protein carbonyl formation on serum albumin and oxidation of human low-density lipoprotein. The direct scavenging of HOCl by PDTC was demonstrated by two quantitative methods, oxidation of ferrocyanide and chlorination of monochlorodimedon. In all assay systems, PDTC was two to three times more potent than GSH and NAC, while diethyldithiocarbamate was about as effective as PDTC. These data demonstrate that PDTC is a potent antioxidant against HOCl-induced protein oxidative damage, suggesting that PDTC might be useful in the prevention and treatment of inflammatory conditions.","pmid":"12459467","doi":"10.1016/s0014-5793(02)03637-2","url":"https://pubmed.ncbi.nlm.nih.gov/12459467/"},{"id":2514,"title":"Detection of HOCl-mediated protein oxidation products in the extracellular matrix of human atherosclerotic plaques.","authors":"Woods, Alan A; Linton, Stuart M; Davies, Michael J","year":2003,"date":"2003 Mar 1","journal":"The Biochemical journal","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Oxidation is believed to play a role in atherosclerosis. Oxidized lipids, sterols and proteins have been detected in early, intermediate and advanced human lesions at elevated levels. The spectrum of oxidized side-chain products detected on proteins from homogenates of advanced human lesions has been interpreted in terms of the occurrence of two oxidative mechanisms, one involving oxygen-derived radicals catalysed by trace transition metal ions, and a second involving chlorinating species (HOCl or Cl2), generated by the haem enzyme myeloperoxidase (MPO). As MPO is released extracellularly by activated monocytes (and possibly macrophages) and is a highly basic protein, it would be expected to associate with polyanions such as the glycosaminoglycans of the extracellular matrix, and might result in damage being localized at such sites. In this study proteins extracted from extracellular matrix material obtained from advanced human atherosclerotic lesions are shown to contain elevated levels of oxidized amino acids [3,4-dihydroxyphenylalanine (DOPA), di-tyrosine, 2-hydroxyphenylalanine ( o-Tyr)] when compared with healthy (human and pig) arterial tissue. These matrix-derived materials account for 83-96% of the total oxidized protein side-chain products detected in these plaques. Oxidation of matrix components extracted from healthy artery tissue, and model proteins, with reagent HOCl is shown to give rise to a similar pattern of products to those detected in advanced human lesions. The detection of elevated levels of DOPA and o-Tyr, which have been previously attributed to the occurrence of oxygen-radical-mediated reactions, by HOCl treatment, suggests an alternative route to the formation of these materials in plaques. This is believed to involve the formation and subsequent decomposition of protein chloramines.","pmid":"12456264","doi":"10.1042/BJ20021710","url":"https://pubmed.ncbi.nlm.nih.gov/12456264/"},{"id":2521,"title":"Human neutrophil oxidative bursts and their in vitro modulation by different N-acetylcysteine concentrations.","authors":"Allegra, Luigi; Dal Sasso, Monica; Bovio, Cinzia; Massoni, Carola; Fonti, Elena; Braga, Pier Carlo","year":2002,"date":"2002","journal":"Arzneimittel-Forschung","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Reactive oxygen species released by activated polymorphonuclear leukocytes as an expression of their defensive function are considered to be a major source of the cytotoxic oxidant stress, that triggers a self-sustaining phlogogenic loop in the respiratory system. N-Acetylcysteine (CAS 616-91-1, NAC), a known mucolytic drug, possesses also antioxidant properties, but it undergoes a rapid and extensive first-pass metabolism resulting in low tissue availability. Thus to further improve the NAC bioavailability a single oral administration of 1200 mg NAC has been recently proposed. This study has been performed to investigate in vitro by means of luminol amplified chemiluminescence the ability of the concentration of 35 mumol/l NAC available after single oral administration of 1200 NAC to interfere with human neutrophil oxidative burst evoked by both corpuscolate and soluble stimulants, in comparison with 16 mumol/l NAC, the serum concentration obtainable after single oral administration of 600 mg NAC. At concentrations of 16 and 35 mumol/l, NAC significantly reduced in a concentration-dependent manner the activation of polymorphonuclear neutrophils (PMNs) oxidative bursts induced by all of the stimulants (C. albicans, formyl-methionyl-leucyl-phenylalanine (fMLP), phorbol myristate acetate (PMA)). This effect was also present in cell-free systems, thus confirming the scavenger activity of these two concentrations of NAC. The fact that no effects were seen on PMN phagocytosis and bacterial killing indicates that NAC has no negative influence on other PMN functions such as antimicrobial activity.","pmid":"12404881","doi":"10.1055/s-0031-1299949","url":"https://pubmed.ncbi.nlm.nih.gov/12404881/"},{"id":2522,"title":"Predicting drug-induced agranulocytosis: characterizing neutrophil-generated metabolites of a model compound, DMP 406, and assessing the relevance of an in vitro apoptosis assay for identifying drugs that may cause agranulocytosis.","authors":"Iverson, S; Zahid, N; Uetrecht, J P","year":2002,"date":"2002 Nov 10","journal":"Chemico-biological interactions","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"DMP 406 is a clozapine analogue developed by Dupont-Pharma for the treatment of schizophrenia. Unfortunately it caused agranulocytosis in dogs during preclinical studies. Clozapine also causes agranulocytosis and this is believed to be due to a reactive nitrenium ion metabolite produced by neutrophils. We studied the oxidation of DMP 406 by activated neutrophils and found that the major reactive species that is produced is not a nitrenium ion but rather an imine. This metabolite is similar to the reactive metabolite that has been proposed to be responsible for mianserin-induced agranulocytosis. Therefore we also studied the oxidation of mianserin by activated neutrophils and found that, although the major species is an iminium ion, it also bears a lactam moiety in the piperazine ring resulting from further oxidation. We usually find that HOCl is a good model system for the production of reactive metabolites of drugs that are formed by activated neutrophils, but in the case of both DMP 406 and mianserin, the products produced were significantly different than those formed by activated neutrophils. In contrast, the combination of horseradish peroxidase and hydrogen peroxide (HRP/H(2)O(2)) formed a very similar pattern of products, and this system was used to produce sufficient quantities of metabolites to allow for identification. The reactive metabolites of both DMP 406 and mianserin reacted with a range of nucleophiles, but in many cases the reaction was reversible. The best nucleophile for trapping these reactive metabolites was cyanide. It has been demonstrated that the products of clozapine oxidation by HRP/H(2)O(2), presumably the nitrenium ion, induced apoptosis in neutrophils at therapeutic concentrations of clozapine. It has been suggested that this process is involved in the mechanism of clozapine-induced agranulocytosis. We tested DMP 406 and mianserin in this system to see if the ability of a reactive metabolite of a drug to cause apoptosis could predict the ability of that drug to cause agranulocytosis. We used clozapine as a positive control and we also tested olanzapine, a drug that forms a reactive metabolite similar to that of clozapine but is given at a lower dose and does not cause agranulocytosis. We found that DMP 406 did not increase apoptosis at concentrations below 50 microM, and although mianserin did increase apoptosis at 10 microM this is above the therapeutic concentration. Olanzapine caused an increase in apoptosis at the same concentration as clozapine (1 microM), but because its therapeutic concentration is lower, this concentration was above the pharmacological range. There was no increase in apoptosis with any drug in the absence of HRP/H(2)O(2). These results indicate that this assay is unable to reliably predict the ability of different types of drugs to cause agranulocytosis. This is not a surprising result given that different drugs may induce agranulocytosis by different mechanisms.","pmid":"12399162","doi":"10.1016/s0009-2797(02)00061-3","url":"https://pubmed.ncbi.nlm.nih.gov/12399162/"},{"id":2528,"title":"Nitration and chlorination of folic acid by peroxynitrite and hypochlorous acid, and the selective binding of 10-nitro-folate to folate receptor beta.","authors":"Nakamura, Motoyuki; Nagayoshi, Ryusaku; Ijiri, Kosei; Nakashima-Matsushita, Noriko; Takeuchi, Toru; Matsuyama, Takami","year":2002,"date":"2002 Oct 11","journal":"Biochemical and biophysical research communications","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The aim of this work was to characterize folates modified by ONOO(-) and HOCl and to evaluate the binding capacity of folates modified by ONOO(-) to folate receptor alpha and beta. For the modification of folate by ONOO(-), folic acid was reacted with the combination of PMA activated PMN and PAPA NONOate or chemically synthesized ONOO(-). For the modification of folate by HOCl, folic acid was reacted with the combination of MPO and H(2)O(2) or NaOCl. The structures of products were determined by 1H-NMR and MALDI-TOF mass. Nitrated folate species were identified as 10-nitro-folate and 12-nitro-folate, and chlorinated folate was identified as 12-chloro-folate. The 10-nitro-folate showed the selective binding to FR-beta, compared to folic acid.","pmid":"12372420","doi":"10.1016/s0006-291x(02)02359-8","url":"https://pubmed.ncbi.nlm.nih.gov/12372420/"},{"id":2529,"title":"Seawater in treatment of waste waters.","authors":"Chunilall, V; Covender, M; Jonnalagadda, S B","year":2002,"date":"2002 Sep","journal":"Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Hypochlorite which is generated electrolytically from seawater under optimized conditions was evaluated for its (i) bacterial sensitivity to Escherichia coli in comparison to commercial bleaches and (ii) utilization in the treatment of sanitary effluent. Effective bacterial growth inhibition occurs using the hypochlorite containing seawater. Waste water samples from sewage treatment plant, from two sampling points, i.e., one after primary treatment (Sample 1) and the second prior to the discharge of the effluent into the river (Sample 2) were analyzed. Sample 1 was subjected to the hypochlorite treatment and Sample 2 was used to assess the treatment work's efficiency. Quality parameters namely Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Dissolved Solids (DS), Suspended Solids (SS) were monitored at each sampling point. The addition of hypochlorite to sample at point 1 lowered the BOD and COD levels and improved the water quality.","pmid":"12369643","doi":"10.1081/ese-120013274","url":"https://pubmed.ncbi.nlm.nih.gov/12369643/"},{"id":2531,"title":"Reaction of lactoperoxidase compound I with halides and thiocyanate.","authors":"Furtmüller, Paul Georg; Jantschko, Walter; Regelsberger, Günther; Jakopitsch, Christa; Arnhold, Jürgen; Obinger, Christian","year":2002,"date":"2002 Oct 1","journal":"Biochemistry","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Lactoperoxidase (LPO) is found in mucosal surfaces and exocrine secretions, including milk, tears, and saliva, and has physiological significance in antimicrobial defense which involves (pseudo-) halide oxidation. This study for the first time presents transient kinetic measurements of the reactivity of its competent redox intermediate compound I with halides and thiocyanate, using the sequential stopped-flow technique. Compound I was produced with either H(2)O(2) [(1.1 +/- 0.1) x 10(7) M(-1) s(-1)] or hypochlorous acid [(3.2 +/- 0.1) x 10(7) M(-1) (s-1)]. At pH 7 and 15 degrees C, the two-electron reduction of compound I to native LPO by bromide and iodide has a second-order rate constant of (4.1 +/- 0.1) x 10(4) M(-1) s(-1) and (1.2 +/- 0.04) x 10(8) M(-1) s(-1), respectively. With thiocyanate the reaction is extremely fast (2.0 x 10(8) M(-1) s(-1)), whereas chloride cannot function as electron donor. The results are discussed with respect to known kinetic data of homologous mammalian peroxidases and to the physiological role of LPO in antimicrobial defense.","pmid":"12269834","doi":"10.1021/bi026326x","url":"https://pubmed.ncbi.nlm.nih.gov/12269834/"},{"id":2532,"title":"Skin toxicokinetics of mustard gas in the guinea pig: effect of hypochlorite and safety aspects.","authors":"Wormser, Uri; Brodsky, Berta; Sintov, Amnon","year":2002,"date":"2002 Sep","journal":"Archives of toxicology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Sulfur mustard (SM, mustard gas) is a chemical warfare vesicant that rapidly penetrates the skin due to its hydrophobicity. This study measured the rate of SM disappearance from the skin after topical application of the vesicant. In both fur-covered and hairless animals, the remaining toxicant levels measured 60 min after exposure to undiluted SM were 0.6% and 0.3%, respectively, of the initially applied SM amount. However, SM concentration reached 0.4% of the initial dose 3 h following exposure in female fur-covered guinea pigs. SM quantities extracted from skin of male fur-covered and hairless guinea pigs immediately after 16 min of exposure to SM vapor were 12.2 and 21.8 microg, respectively; levels declined to 1.6 and 1.7 microg at 30 and 15 min following termination of exposure of male fur-covered and hairless guinea pigs, respectively. Three swabbing treatments of undiluted SM-exposed skin with gauze pads soaked in 0.5% hypochlorite caused 68% reduction in skin SM content. Similar findings were obtained when hypochlorite was replaced by water (64% reduction). SM content in the gauze pads was 59, 38 and 25 microg, respectively, for the first, second and third decontamination processes with water. No SM was detected in the gauze pads soaked with hypochlorite. In vitro studies showed that incubation of SM with 0.5% hypochlorite at a ratio of 10:1 (v/v) did not cause SM inactivation, whereas 4% hypochlorite reduced SM levels by 17%. However, at a decontaminant:SM ratio of 1000:1, 0.5% and 4% hypochlorite reduced SM levels by 92% and 99%, respectively. These findings are important for health authorities and regulatory agencies in planning precautionary steps to be taken in case of emergency and in routine laboratory work.","pmid":"12242609","doi":"10.1007/s00204-002-0362-6","url":"https://pubmed.ncbi.nlm.nih.gov/12242609/"},{"id":2538,"title":"Inhibition of hypochlorous acid-induced cellular toxicity by nitrite.","authors":"Whiteman, Matthew; Hooper, D Craig; Scott, Gwen S; Koprowski, Hilary; Halliwell, Barry","year":2002,"date":"2002 Sep 17","journal":"Proceedings of the National Academy of Sciences of the United States of America","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Chronic inflammation results in increased nitrogen monoxide (.NO) formation and the accumulation of nitrite (NO(2-)). Neutrophils stimulated by various inflammatory mediators release myeloperoxidase to produce the cytotoxic agent hypochlorous acid (HOCl). Exposure of chondrocytic SW1353 cells to HOCl resulted in a concentration- and time-dependent loss in viability, ATP, and glutathione levels. Treatment of cells with NO(2-) but not nitrate (NO(3-)) substantially decreased HOCl-dependent cellular toxicity even when NO(2-) was added at low (microM) concentrations. In contrast, NO(2-) alone (even at 1 mM concentrations) did not affect cell viability or ATP and glutathione levels. These data suggest that NO(2-) accumulation at chronic inflammatory sites, where both HOCl and.NO are overproduced, may be cytoprotective against damage caused by HOCl. We propose that this is because HOCl is removed by reacting with NO(2-) to give nitryl chloride (NO2Cl), which is less damaging in our cell system.","pmid":"12221280","doi":"10.1073/pnas.152462399","url":"https://pubmed.ncbi.nlm.nih.gov/12221280/"},{"id":2541,"title":"Development of a standard test to assess the resistance of Staphylococcus aureus biofilm cells to disinfectants.","authors":"Luppens, Suzanne B I; Reij, Martine W; van der Heijden, Rob W L; Rombouts, Frank M; Abee, Tjakko","year":2002,"date":"2002 Sep","journal":"Applied and environmental microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"A standardized disinfectant test for Staphylococcus aureus cells in biofilms was developed. Two disinfectants, the membrane-active compound benzalkonium chloride (BAC) and the oxidizing agent sodium hypochlorite, were used to evaluate the biofilm test. S. aureus formed biofilms on glass, stainless steel, and polystyrene in a simple system with constant nutrient flow that mimicked as closely as possible the conditions used in the current standard European disinfectant test (EN 1040). The biofilm that was formed on glass contained cell clumps and extracellular polysaccharides. The average surface coverage was 60%, and most (92%) of the biofilm cells were viable. Biofilm formation and biofilm disinfection in different experiments were reproducible. For biofilms exposed to BAC and hypochlorite the concentrations needed to achieve 4-log killing were 50 and 600 times higher, respectively, than the concentrations needed to achieve this level of killing with the European phase 1 suspension test cells. Our results show that a standardized disinfectant test for biofilm cells is a useful addition to the current standard tests.","pmid":"12200265","doi":"10.1128/AEM.68.9.4194-4200.2002","url":"https://pubmed.ncbi.nlm.nih.gov/12200265/"},{"id":2542,"title":"Loss of oxidized and chlorinated bases in DNA treated with reactive oxygen species: implications for assessment of oxidative damage in vivo.","authors":"Whiteman, Matthew; Hong, Huang Shan; Jenner, Andrew; Halliwell, Barry","year":2002,"date":"2002 Aug 30","journal":"Biochemical and biophysical research communications","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Oxidative damage to DNA has been reported to occur in a wide variety of disease states. The most widely used \"marker\" for oxidative DNA damage is 8-hydroxyguanine. However, the use of only one marker has limitations. Exposure of calf thymus DNA to an .OH-generating system (CuCl(2), ascorbate, H(2)O(2)) or to hypochlorous acid (HOCl), led to the extensive production of multiple oxidized or chlorinated DNA base products, as measured by gas chromatography-mass spectrometry. The addition of peroxynitrite (ONOO(-)) (<200 microM) or SIN-1 (1mM) to oxidized DNA led to the extensive loss of 8-hydroxyguanine, 5-hydroxycytosine, 2,6-diamino-4-hydroxy-5-formamidopyrimidine, 2-hydroxyadenine, 8-hydroxyadenine, and 4,6-diamino-5-formamidopyrimidine were lost at higher ONOO(-) concentrations (>200 microM). Exposure of DNA to HOCl led to the generation of 5-Cl uracil and 8-Cl adenine and addition of ONOO(-) (<200 microM) or SIN-1 (1mM) led to an extensive loss of 8-Cl adenine and a small loss of 5-Cl uracil at higher concentrations (>500 microM). An .OH-generating system (CuCl(2)/ascorbate/H(2)O(2)) could also destroy these chlorinated species. Treatment of oxidized or chlorinated DNA with acidified nitrite (NO(2)(-), pH 3) led to substantial loss of various base lesions, in particular 8-OH guanine, 5-OH cytosine, thymine glycol, and 8-Cl adenine. Our data indicate the possibility that when ONOO(-), nitrite in regions of low pH or .OH are produced at sites of inflammation, levels of certain damaged DNA bases could represent an underestimate of ongoing DNA damage. This study emphasizes the need to examine more than one modified DNA base when assessing the role of reactive species in human disease.","pmid":"12200130","doi":"10.1016/s0006-291x(02)02018-1","url":"https://pubmed.ncbi.nlm.nih.gov/12200130/"},{"id":2543,"title":"[Perspectives of improvement of water disinfection technology in superficial sources].","authors":"Terent'ev, V I; Gritsenko, V K; Lopatin, S A; Kir'ianova, L F; Raevskiĭ, K K; Fokanov, V P; Shallar', A V","year":2002,"date":"2002 May-Jun","journal":"Gigiena i sanitariia","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"","pmid":"12198898","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/12198898/"},{"id":2555,"title":"Human neutrophils use the myeloperoxidase-hydrogen peroxide-chloride system to chlorinate but not nitrate bacterial proteins during phagocytosis.","authors":"Rosen, Henry; Crowley, Jan R; Heinecke, Jay W","year":2002,"date":"2002 Aug 23","journal":"The Journal of biological chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The generation of extracellular oxidants by neutrophils has been widely investigated, but knowledge about the chemical reactions that occur in the phagolysosome, the cellular compartment that kills pathogens, is more limited. One important pathway may involve the production of potent halogenating agents such as hypochlorous acid (HOCl) by the myeloperoxidase-hydrogen peroxide-halide system. However, explorations of the oxidation chemistry of phagolysosomes have been hampered by the organelle's inaccessibility. To overcome this limitation, we recovered Escherichia coli that had been internalized by human neutrophils. We then analyzed the bacterial proteins for 3-chlorotyrosine, a stable marker of damage by HOCl. Mass spectrometric analysis revealed that levels of 3-chlorotyrosine in E. coli proteins increased markedly after the bacteria were internalized by human neutrophils. This increase failed to occur in E. coli exposed to neutrophils deficient in NADPH oxidase or myeloperoxidase, implicating H(2)O(2) and myeloperoxidase in the halogenation reaction. The extent of protein chlorination by normal neutrophils paralleled bacterial killing. Our observations support the view that the phagolysosome of human neutrophils uses the myeloperoxidase-hydrogen peroxide-chloride system to chlorinate bacterial proteins. In striking contrast, human neutrophils failed to nitrate bacterial proteins unless the medium was supplemented with 1 mm nitrite, and the level of nitration was low. Protein chlorination associated with bacterial killing was unaffected by the presence of nitrite in the medium. Nitration required NADPH oxidase but appeared to be independent of myeloperoxidase, suggesting that neutrophils can nitrate proteins through a pathway that requires nitrite but is independent of myeloperoxidase.","pmid":"12060654","doi":"10.1074/jbc.M202331200","url":"https://pubmed.ncbi.nlm.nih.gov/12060654/"},{"id":2556,"title":"Neutrophil hypochlorous acid production is impaired in multiple organ failure patients with candidaemia; reversal with antifungal agents.","authors":"Hussien, M; Delecata, R J; Carey, P D","year":2002,"date":"2002 Apr","journal":"Inflammation research : official journal of the European Histamine Research Society ... [et al.]","category":"Water, sanitation & biosecurity","evidence":"Clinical trial","relevance":"High","abstract":"OBJECTIVE AND DESIGN: Neutrophil-derived hypochlorous acid (PMN-HOCL) is a potent bactericidal and fungicidal agent. Neutrophils from patients with multiple organ failure (MOF) have an altered ability to inhibit Candida albicans. Conversely antifungal agents are effective in decreasing mortality in MOF patients with fungaemia. We determined the effect on the rate of production of PMN-HOCL in a series of MOF patients with C. albicans fungaemia when antifungal agents are administered. SUBJECTS AND METHODS: Eleven patients with MOF were recruited. Four patients had culture-positive C. albicans fungaemia (group 1) and 7 patients with MOF but without C. albicans fungaemia acted as controls (group 2). HOCL assays were performed on peripheral blood PMN obtained from group 1 and group 2 patients. RESULTS: The maximum PMN-HOCL production rate for group 1 increased from 0.24 nmol/million PMN/min to 0.8 nmol/million PMN/min after treatment with antifungal agents (p < 0.01) (Mann-Whitney U test) whereas the PMN-HOCL kinetic (rate) curves for group 1 post-treatment and for group 2 were similar (student's-t-test). CONCLUSIONS: These findings suggest that antifungal treatment improve PMN-HOCL production in MOF patients with C. albicans fungaemia and may improve the effectiveness in eradicating the organism.","pmid":"12058960","doi":"10.1007/pl00000295","url":"https://pubmed.ncbi.nlm.nih.gov/12058960/"},{"id":2560,"title":"Novel products generated from 2'-deoxyguanosine by hypochlorous acid or a myeloperoxidase-H2O2-Cl- system: identification of diimino-imidazole and amino-imidazolone nucleosides.","authors":"Suzuki, Toshinori; Masuda, Mitsuharu; Friesen, Marlin D; Fenet, Bernard; Ohshima, Hiroshi","year":2002,"date":"2002 Jun 1","journal":"Nucleic acids research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Hypochlorous acid (HOCl), generated by myeloperoxidase from H2O2 and Cl-, plays an important role in host defense and inflammatory tissue injury. We report here the identification of products generated from 2'-deoxyguanosine (dGuo) with HOCl. When 1 mM dGuo and 1 mM HOCl were reacted at pH 7.4 and 37 degrees C for 15 min and the reaction was terminated with N-acetylcysteine (N-AcCys), two products were generated in addition to 8-chloro-2'-deoxyguanosine (8-Cl-dGuo). One was identified as an amino-imidazolone nucleoside (dIz), a previously reported product of dGuo with other oxidation systems. The other was identified as a novel diimino-imidazole nucleoside, 2,5-diimino-4-[(2-deoxy-beta-D-erythro-pentofuranosyl)amino]-2H,5H-imidazole (dDiz) by spectrometric measurements. The yields were 1.4% dDiz, 0.6% dIz and 2.4% 8-Cl-dGuo, with 61.5% unreacted dGuo. Precursors of dDiz and dIz containing a chlorine atom were found in the reaction solution in the absence of termination by N-AcCys. dDiz, dIz and 8-Cl-dGuo were also formed from the reaction of dGuo with myeloperoxidase in the presence of H2O2 and Cl- under mildly acidic conditions. These results imply that dDiz and dIz are generated from dGuo via chlorination by electrophilic attack of HOCl and subsequent dechlorination by N-AcCys. These products may play a role in cytotoxic and/or genotoxic effects of HOCl.","pmid":"12034845","doi":"10.1093/nar/30.11.2555","url":"https://pubmed.ncbi.nlm.nih.gov/12034845/"},{"id":2561,"title":"Efficacy of HOCl scavenging by sulfur-containing compounds: antioxidant activity of glutathione disulfide?","authors":"den Hartog, Gertjan J M; Haenen, Guido R M M; Vegt, Erik; van der Vijgh, Wim J F; Bast, Aalt","year":2002,"date":"2002 Mar-Apr","journal":"Biological chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HOCl) is a bactericidal compound formed by activated neutrophils during inflammation. Overproduction of HOCl causes damage to tissues at the site of neutrophil accumulation. The deleterious effects of excessive HOCl formation can be attenuated using antioxidants. Thiols and thioethers are known to be very effective HOCl scavengers. In the present study, the potency of several sulfur-containing compounds to protect acetylcholinesterase, glutathione S-transferase P1-1 (GST P1-1) and alpha1-antiproteinease against inactivation by HOCl was determined. Surprisingly, glutathione disulfide was an effective protector of acetylcholinesterase against hypochlorous acid. Glutathione disulfide did not provide protection for GST P1-1 and alpha1-antiproteinease against oxidative inactivation by HOCl. The implications of this finding are discussed.","pmid":"12033460","doi":"10.1515/BC.2002.073","url":"https://pubmed.ncbi.nlm.nih.gov/12033460/"},{"id":2562,"title":"Human neutrophils oxidize low-density lipoprotein by a hypochlorous acid-dependent mechanism: the role of vitamin C.","authors":"Carr, Anitra C; Frei, Balz","year":2002,"date":"2002 Mar-Apr","journal":"Biological chemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Oxidatively modified low-density lipoprotein (LDL) has been strongly implicated in the pathogenesis of atherosclerosis. Peripheral blood leukocytes, such as neutrophils, can oxidize LDL by processes requiring superoxide and redox-active transition metal ions; however, it is uncertain whether such catalytic metal ions are available in the artery wall. Stimulated leukocytes also produce the reactive oxidant hypochlorous acid (HOCl) via the heme enzyme myeloperoxidase. Since myeloperoxidase-derived HOCl may be a physiologically relevant oxidant in atherogenesis, we investigated the mechanisms of neutrophil-mediated LDL modification and its possible prevention by the antioxidant ascorbate (vitamin C). As a sensitive marker of LDL oxidation, we measured LDL thiol groups. Stimulated human neutrophils (5x10(6) cells/ml) incubated with human LDL (0.25 mg protein/ml) time-dependently oxidized LDL thiols (33% and 79% oxidized after 10 and 30 min, respectively). Supernatants from stimulated neutrophils also oxidized LDL thiols (33% oxidized after 30 min), implicating long-lived oxidants such as N-chloramines. Experiments using specific enzyme inhibitors and oxidant scavengers showed that HOCl, but not hydrogen peroxide nor superoxide, plays a critical role in LDL thiol oxidation by neutrophils. Ascorbate (200 microM) protected against neutrophil-mediated LDL thiol oxidation for up to 15 min of incubation, after which LDL thiols became rapidly oxidized. Although stimulated neutrophils accumulated ascorbate during oxidation of LDL, pre-loading of neutrophils with ascorbate did not attenuate oxidant production by the cells. Thus, activated neutrophils oxidize LDL thiols by HOCl- and N-chloramine-dependent mechanisms and physiological concentrations of vitamin C delay this process, most likely due to scavenging of extracellular oxidants, rather than by attenuating neutrophil oxidant production.","pmid":"12033452","doi":"10.1515/BC.2002.065","url":"https://pubmed.ncbi.nlm.nih.gov/12033452/"},{"id":2564,"title":"The reactions of hypochlorous acid, the reactive oxygen species produced by myeloperoxidase, with lipids.","authors":"Spickett, C M; Jerlich, A; Panasenko, O M; Arnhold, J; Pitt, A R; Stelmaszyńska, T; Schaur, R J","year":2000,"date":"2000","journal":"Acta biochimica Polonica","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"Myeloperoxidase (MPO), an abundant enzyme in phagocytes, has been implicated in the pathogenesis of various inflammatory diseases including atherosclerosis. The major oxidant produced by MPO, hypochlorous acid (HOCl), is able to modify a great variety of biomolecules by chlorination and/or oxidation. In this paper the reactions of lipids (preferentially unsaturated fatty acids and cholesterol) with either reagent HOCl or HOCl generated by the MPO-hydrogen peroxide-chloride system are reviewed. One of the major issues has been whether the reaction of HOCl with lipids of low density lipoprotein (LDL) yields predominantly chlorohydrins or lipid hydroperoxides. Electrospray mass spectrometry provided direct evidence that chlorohydrins rather than peroxides are the major products of HOCl- or MPO-treated LDL phosphatidylcholines. Nevertheless lipid peroxidation is a possible alternative reaction of HOCl with polyunsaturated fatty acids if an additional radical source such as pre-formed lipid hydroperoxides is available. In phospholipids carrying a primary amino group such as phosphatidylethanolamine chloramines are the preferred products compared to chlorohydrins. Cholesterol can be converted by HOCl to great variety of oxysterols besides three isomers of chlorohydrins. For the situation in vivo it appears that the type of reaction occurring between HOCl and lipids would very much depend on the circumstances, e.g. the pH and the presence of radical initiators. The biological effects of lipid chlorohydrins are not yet well understood. It has been shown that chlorohydrins of both unsaturated fatty acids as well as of cholesterol may cause lysis of target cells, possibly by disruption of membrane structures.","pmid":"11996112","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/11996112/"},{"id":2565,"title":"Immunology. Lethal weapons.","authors":"Roos, Dirk; Winterbourn, Christine C","year":2002,"date":"2002 Apr 26","journal":"Science (New York, N.Y.)","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"","pmid":"11976433","doi":"10.1126/science.1071271","url":"https://pubmed.ncbi.nlm.nih.gov/11976433/"},{"id":2569,"title":"Vitamin C protects against hypochlorous Acid-induced glutathione depletion and DNA base and protein damage in human vascular smooth muscle cells.","authors":"Jenner, Andrew M; Ruiz, J Emilio; Dunster, Christina; Halliwell, Barry; Mann, Giovanni E; Siow, Richard C M","year":2002,"date":"2002 Apr 1","journal":"Arteriosclerosis, thrombosis, and vascular biology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HOCl), generated by myeloperoxidase released from activated macrophages, is thought to contribute to vascular dysfunction and oxidation of low density lipoproteins (LDLs) in atherogenesis. We have previously shown that HOCl exposure can cause chlorination and oxidation of isolated DNA and that vitamin C protects human arterial smooth muscle cells against oxidized LDL-mediated damage. We report in the present study that vitamin C attenuates HOCl-induced DNA base and protein damage and depletion of intracellular glutathione (GSH) and ATP in human arterial smooth muscle cells. Cells were pretreated in the absence or presence of 100 micromol/L vitamin C (24 hours) and then exposed to HOCl (0 to 500 micromol/L, 0 to 60 minutes) in the absence of vitamin C. Intracellular GSH and ATP levels were depleted by HOCl treatment, and gas chromatography-mass spectroscopy revealed a concentration- and time-dependent increase in DNA base oxidation and protein damage (measured as 3-chlorotyrosine). Pretreatment of smooth muscle cells with vitamin C significantly reduced the extent of HOCl-induced DNA and protein damage and attenuated decreases in intracellular ATP and GSH. Our findings suggest that physiological levels of vitamin C provide an important antioxidant defense against HOCl-mediated injury in atherosclerosis.","pmid":"11950693","doi":"10.1161/01.atv.0000013785.03265.5c","url":"https://pubmed.ncbi.nlm.nih.gov/11950693/"},{"id":2572,"title":"Effects of Rosa canina fruit extract on neutrophil respiratory burst.","authors":"Daels-Rakotoarison, D A; Gressier, B; Trotin, F; Brunet, C; Luyckx, M; Dine, T; Bailleul, F; Cazin, M; Cazin, J-C","year":2002,"date":"2002 Mar","journal":"Phytotherapy research : PTR","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Respiratory burst leads polymorphonuclear neutrophils (PMN) to produce reactive oxygen species (ROS) such as superoxide anions (O(2)(o-)), hypochlorous acid (HOCl) and hydrogen peroxide (H(2)O(2)) which may possess deleterious effects for the organism. Rosa canina fruits are well known to contain a large amount of vitamin C which is antioxidant. This study was focused on the polyphenolics contained in rose hips to evaluate their antioxidative properties. We prepared a rose hip extract deprived of vitamin C. The extract contained mainly phenolics such as proanthocyanidins and flavonoids. We investigated its effects directly against (O(2)(o-)), HOCl and H(2)O(2) and investigated its effects on isolated PMN. For that, in vitro inflammatory conditions were reproduced by stimulating PMN with stimuli having different transductional pathways, in order to determine a possible mechanism of action. The results showed that the extract can inhibit ROS tested in acellular and cellular systems. The IC(50) obtained were 5.73 mg/L, 1.33 mg/L and 2.34 mg/L respectively for (O(2)(o-)), HOCl and H(2)O(2) in acellular experiments. For cellular experiments, the IC(50) were quite similar. Thus, the extract did not present an effect on PMN metabolism. Therefore, the antioxidative effects of Rosa canina are due not only to vitamin C but also to polyphenolics.","pmid":"11933119","doi":"10.1002/ptr.985","url":"https://pubmed.ncbi.nlm.nih.gov/11933119/"},{"id":2576,"title":"Mechanisms contributing to hypochlorous acid resistance of a Salmonella isolate from a poultry-processing plant.","authors":"Mokgatla, R M; Gouws, P A; Brözel, V S","year":2002,"date":"2002","journal":"Journal of applied microbiology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"AIMS: We have recently reported the isolation of Salmonella that have acquired tolerance to hypochlorous acid (HOCl) (Mokgatla et al. 1998). The aim of this work was to investigate possible protective mechanisms involved in the increased tolerance to HOCl of a selected resistant strain. METHODS AND RESULTS: One resistant (Salmonella 104) and one sensitive (Salmonella 81) isolate in exponential phase were exposed to HOCl at a final active concentration of 28 mg l(-1). Cultures were assayed for superoxide dismutase and catalase activity, as well as for four membrane-bound dehydrogenases (malate, lactate, glutamate and glucose-6-phosphate dehydrogenase). The degree of single-strand breaks in genomic DNA was analysed and lipopolysaccharide profiles determined. The resistant Salmonella isolate differed from the sensitive isolate in a number of ways. It responded within 10 min of exposure by producing catalase and decreasing the activity levels of four membrane-bound dehydrogenases. This combination would lead to lower levels of hydroxyl radicals and singlet oxygen, moieties thought to be integrally involved in the antibacterial action of HOCl. Furthermore, the resistant strain did not display the same degree of DNA damage as did the sensitive strain. CONCLUSIONS: Strain 104 is believed to grow in the presence of 28 mg l(-1) HOCl by protecting itself against HOCl by decreasing the levels of species that could react with HOCl to generate toxic reactive oxygen radicals and by improved DNA damage repair mechanisms. SIGNIFICANCE AND IMPACT OF THE STUDY: The occurrence of Salmonella able to grow in the presence of 28 mg l(-1) HOCl is of relevance to the food-processing and drinking water treatment industries as these strains would survive sanitation regimes.","pmid":"11872134","doi":"10.1046/j.1365-2672.2002.01565.x","url":"https://pubmed.ncbi.nlm.nih.gov/11872134/"},{"id":2579,"title":"The role of advanced oxidation protein products in regulation of dendritic cell function.","authors":"Alderman, Charles J J; Shah, Sachit; Foreman, John C; Chain, Benjamin M; Katz, David R","year":2002,"date":"2002 Mar 1","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The basis for this study was the \"injury hypothesis,\" which holds that release of micro-environmental constituents, such as reactive oxygen species and oxidants, acts as a signal, and potential activator, of dendritic cell (DC)-mediated antigen presentation. Following this oxidative stress, dityrosine containing cross-linked proteins, advanced oxidation protein products (AOPP), are known to be generated, and we proposed that they may serve as moieties that mediate such signals. Therefore, the effect of AOPP on DCs has been examined in vitro. There were no AOPP-induced changes in DC phenotype as judged by expression of typical surface costimulatory molecules. However, at higher cell concentrations AOPP-treated DCs were more potent inducers in an oxidative mitogenesis assay than controls. Thus, AOPP may act like superantigens, allowing for bypass of upregulation of costimulation, and, either alone or in synergy with oxidants themselves, serving as amplifiers of DC function.","pmid":"11864777","doi":"10.1016/s0891-5849(01)00735-3","url":"https://pubmed.ncbi.nlm.nih.gov/11864777/"},{"id":2585,"title":"Indirect electrochemical treatment of saline dyestuff wastewater.","authors":"Zhan, X M; Wang, J L; Wen, X H; Qian, Y","year":2001,"date":"2001 Sep","journal":"Environmental technology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Dyestuff wastewater is always found to contain highly-concentrated sodium chloride. In many cases, biological processes are not available to dispose saline dyestuff wastewater. In this paper, both direct a nd indirect electrochemical oxidation of saline dyestuff wastewater were carried out and the accessibility of indirect electrochemical oxidation by electrochemically generated hypochlorite was investigated. It was found that the indirect electrochemical process removed COD by 87% and color by 100% in 50 minutes while the direct electrochemical process removed COD by 47% and color by 50% in 5 hours. The rate-limiting step for hypochlorite evolution at the anode was found to be diffusion-controlled. For the two processes, COD removal kinetics could be simplified as the pseudo first-order kinetics. The rate constants of COD removal were 0.038 min(-1) and 0.0018 min(-1) for the indirect and direct oxidation respectively. Current efficiency of the indirect process was I while that of the direct process was 0.16; cost efficiency of the two processes was 8,000 mg-COD (kWh)(-1) and 1,000 mg-COD (kWh)(-1) respectively. It can be concluded that the indirect electrochemical process is a promising method for the disposal of saline dyestuff wastewater.","pmid":"11816771","doi":"10.1080/09593332208618222","url":"https://pubmed.ncbi.nlm.nih.gov/11816771/"},{"id":2587,"title":"Hypochlorite-induced damage to DNA, RNA, and polynucleotides: formation of chloramines and nitrogen-centered radicals.","authors":"Hawkins, Clare L; Davies, Michael J","year":2002,"date":"2002 Jan","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Stimulated monocytes and neutrophils generate hypochlorite (HOCl) via the release of the enzyme myeloperoxidase and hydrogen peroxide. HOCl is a key bactericidal agent, but can also damage host tissue. As there is a strong link between chronic inflammation and some cancers, we have investigated HOCl damage to DNA, RNA, and polynucleotides. Reaction of HOCl with these materials is shown to yield multiple semistable chloramines (RNHCl/RR'NCl), which are the major initial products, and account for 50-95% of the added HOCl. These chloramines decay by thermal and metal-ion catalyzed processes, to give nucleoside-derived, nitrogen-centered, radicals. The latter have been characterized by EPR spin trapping. The propensity for radical formation with polynucleotides is cytidine > adenosine = guanosine > uridine = thymidine. The rates of decay, and yield of radicals formed, are dependent on the nature of the nucleobase on which they are formed, with chloramines formed from ring heterocyclic amine groups being less stable than those formed on exocyclic amines (RNH2 groups). Evidence is presented for chlorine transfer from the former, kinetically favored, sites to the more thermodynamically favored exocyclic amines. EPR experiments have also provided evidence for the rapid addition of pyrimidine-derived nitrogen-centered radicals to other nucleobases to give dimers and the oxidation of DNA by radicals derived from preformed nucleoside chloramines. Direct reaction of HOCl with plasmid DNA gives rise to single- and double-strand breaks via chloramine-mediated reactions. Preformed nucleoside chloramines also induce plasmid cleavage, though this only occurs to a significant extent with unstable thymidine- and uridine-derived chloramines, where radical formation is rapid. Overall the data rationalize the preferential formation of chlorinated 2'-deoxycytidine and 2'-deoxyadenosine in DNA and suggest that DNA damage induced by HOCl, and preformed chloramines, occurs at sequence-specific sites.","pmid":"11800600","doi":"10.1021/tx015548d","url":"https://pubmed.ncbi.nlm.nih.gov/11800600/"},{"id":2591,"title":"Superoxide radicals can act synergistically with hypochlorite to induce damage to proteins.","authors":"Hawkins, Clare L; Rees, Martin D; Davies, Michael J","year":2002,"date":"2002 Jan 2","journal":"FEBS letters","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"Activated phagocytes generate both superoxide radicals via a respiratory burst, and HOCl via the concurrent release of the haem enzyme myeloperoxidase. Amine and amide functions on proteins and carbohydrates are major targets for HOCl, generating chloramines (RNHCl) and chloramides (RC(O)NClR'), which can accumulate to high concentrations (>100 microM). Here we show that superoxide radicals catalyse the decomposition of chloramines and chloramides to reactive nitrogen-centred radicals, and increase the extent of protein fragmentation compared to that observed with either superoxide radicals or HOCl, alone. This synergistic action may be of significance at sites of inflammation, where both superoxide radicals and chloramines/chloramides are formed simultaneously.","pmid":"11755528","doi":"10.1016/s0014-5793(01)03226-4","url":"https://pubmed.ncbi.nlm.nih.gov/11755528/"},{"id":2592,"title":"Chlorination of bacterial and neutrophil proteins during phagocytosis and killing of Staphylococcus aureus.","authors":"Chapman, Anna L P; Hampton, Mark B; Senthilmohan, Revathy; Winterbourn, Christine C; Kettle, Anthony J","year":2002,"date":"2002 Mar 22","journal":"The Journal of biological chemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Myeloperoxidase is proposed to play a central role in bacterial killing by generating hypochlorous acid within neutrophil phagosomes. However, it has yet to be demonstrated that these inflammatory cells target hypochlorous acid against bacteria inside phagosomes. In this investigation, we treated Staphylococcus aureus with varying concentrations of reagent hypochlorous acid and found that even at sublethal doses, it converted some tyrosine residues in their proteins to 3-chlorotyrosine and 3,5-dichlorotyrosine. To determine whether or not ingested bacteria were exposed to hypochlorous acid in neutrophil phagosomes, we labeled their proteins with [(13)C(6)]tyrosine and used gas chromatography with mass spectrometry to identify the corresponding chlorinated isotopes after the bacteria had been phagocytosed. Chlorinated tyrosines were detected in bacterial proteins 5 min after phagocytosis and reached levels of approximately 2.5/1000 mol of tyrosine at 60 min. Inhibitor studies revealed that chlorination was dependent on myeloperoxidase. Chlorinated neutrophil proteins were also detected and accounted for 94% of total chlorinated tyrosine residues formed during phagocytosis. We conclude that hypochlorous acid is a major intracellular product of the respiratory burst. Although some reacts with the bacteria, most reacts with neutrophil components.","pmid":"11733505","doi":"10.1074/jbc.M106134200","url":"https://pubmed.ncbi.nlm.nih.gov/11733505/"},{"id":2597,"title":"Reconstitution of bactericidal activity in chronic granulomatous disease cells by glucose-oxidase-containing liposomes.","authors":"Gerber, C E; Bruchelt, G; Falk, U B; Kimpfler, A; Hauschild, O; Kuçi, S; Bächi, T; Niethammer, D; Schubert, R","year":2001,"date":"2001 Nov 15","journal":"Blood","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Chronic granulomatous disease (CGD) is an inherited primary immunodeficiency characterized by phagocytes devoid of a functioning nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. The failure of CGD phagocytes to produce reactive oxygen species (ROS) results in a marked increase in the susceptibility of affected patients to life-threatening bacterial and fungal infections. This study investigated whether loading of CGD phagocytes with glucose oxidase (GO)-containing liposomes (GOLs) could restore cellular production of bactericidal ROS (eg, H2O2 and HOCl) in vitro. Results indicate that GO encapsulated in liposomes enabled NADPH oxidase-deficient phagocytes to use H2O2 for the production of highly bactericidal HOCl. The intracellular colocalization of bacteria and liposomes (or liposome-derived ferritin) was demonstrated by confocal laser microscopy and electron microscopy. After uptake of GOLs (approximately 0.2 U/mL at 1 mM total lipid concentration, size approximately 180 nm), CGD granulocytes produced HOCl levels comparable to those of normal phagocytes. Remarkably, after treatment with GOLs, CGD phagocytes killed Staphylococcus aureus as efficiently as normal granulocytes. Moreover, treated cells retained sufficient motility toward chemotactic stimuli as measured by chemotaxis assay. Side effects were evaluated by measuring the H2O2 concentrations and the production of methemoglobin in whole blood. These studies revealed that H2O2 produced by GOLs was degraded immediately by the antioxidative capacity of whole blood. Elevated methemoglobin levels were observed only after application of extremely high amounts of GOLs (2 U/mL). In summary, the application of negatively charged GOLs might provide a novel effective approach in the treatment of patients with CGD at high risk for life-threatening infections.","pmid":"11698296","doi":"10.1182/blood.v98.10.3097","url":"https://pubmed.ncbi.nlm.nih.gov/11698296/"},{"id":2604,"title":"Effects of the reactive oxygen species hydrogen peroxide and hypochlorite on endothelial nitric oxide production.","authors":"Jaimes, E A; Sweeney, C; Raij, L","year":2001,"date":"2001 Oct","journal":"Hypertension (Dallas, Tex. : 1979)","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Reactive oxygen species (ROS) hydrogen peroxide (H(2)O(2)) and hypochlorite (HOCl) participate in the pathogenesis of ischemia/reperfusion injury, inflammation, and atherosclerosis. Both NO and ROS are important modulators of vascular tone and architecture and of adhesive interactions between leukocytes, platelets, and vascular endothelium. We studied the effect of H(2)O(2) and HOCl on receptor-dependent (bradykinin [10(-6) mol/L] and ADP [10(-4) mol/L]) and receptor-independent mechanisms (calcium ionophore A23187 [10(-6) mol/L]) of NO production by porcine aortic endothelial cells (ECs). Changes in the level of EC cGMP (the second messenger of NO) were used as a surrogate of NO production. EC cGMP increased 300% in response to bradykinin and A23187 and 200% in response to ADP. Exposure of ECs to H(2)O(2) (50 micromol/L) for 30 minutes significantly impaired cGMP levels in response to ADP, bradykinin, and the receptor-independent NO agonist A23187. In contrast, preincubation with HOCl (50 micromol/L) impaired cGMP production only in response to ADP and bradykinin but not A23187. These concentrations of H(2)O(2) and HOCl did not result in increased EC lethality as assessed by lactate dehydrogenase release. Neither H(2)O(2) nor HOCl affected EC cGMP production in response to NO donor sodium nitroprusside, which suggests that guanylate cyclase is resistant to these oxidants. We also demonstrated that neither H(2)O(2) nor HOCl affects endothelial NO synthase (eNOS) catalytic activity as measured by conversion of L-arginine to L-citrulline in EC homogenates supplemented with eNOS cofactors. The present studies show that H(2)O(2) impairs NO production in response to both receptor-dependent and receptor-independent agonists and that these effects are due, at least in part, to inactivation of eNOS cofactors, whereas HOCl inhibits NO production by interfering with receptor-operated mechanisms at the level of the cell membrane. Concentrations of H(2)O(2) and HOCl used in the present studies have been shown to be generated in vivo during inflammation and ischemia/reperfusion. Therefore, we infer that these effects of H(2)O(2) and HOCl on EC NO production may contribute to disregulated vascular tone and altered leukocyte-EC interactions that occur in vascular injury as a result of those causes in which ROS generation is involved.","pmid":"11641302","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/11641302/"},{"id":2606,"title":"Antimicrobials in periodontal maintenance.","authors":"Jorgensen, M G; Slots, J","year":2001,"date":"2001 Summer","journal":"Journal of dental hygiene : JDH","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"Mechanical and chemical antimicrobial intervention is the mainstay of preventive periodontal therapy. Successful periodontal maintenance care depends upon the ability of oral health care professionals to combat periodontal infections, and patient compliance with prescribed follow-up care. Since tooth brushing, flossing, and oral rinsing do not reach pathogens present in furcations and at the depths of deep periodontal pockets, adequate oral hygiene should include subgingival treatment with home irrigators or other appropriate self-care remedies in patients with these conditions. Povidone-iodine for professional use and diluted bleach for self-care are inexpensive and valuable antimicrobial agents in periodontal maintenance. The present article outlines the prudent use of antimicrobial therapy in periodontal maintenance.","pmid":"11603305","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/11603305/"},{"id":2610,"title":"Neutrophils employ the myeloperoxidase system to generate antimicrobial brominating and chlorinating oxidants during sepsis.","authors":"Gaut, J P; Yeh, G C; Tran, H D; Byun, J; Henderson, J P; Richter, G M; Brennan, M L; Lusis, A J; Belaaouaj, A; Hotchkiss, R S; Heinecke, J W","year":2001,"date":"2001 Oct 9","journal":"Proceedings of the National Academy of Sciences of the United States of America","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"The myeloperoxidase system of neutrophils uses hydrogen peroxide and chloride to generate hypochlorous acid, a potent bactericidal oxidant in vitro. In a mouse model of polymicrobial sepsis, we observed that mice deficient in myeloperoxidase were more likely than wild-type mice to die from infection. Mass spectrometric analysis of peritoneal inflammatory fluid from septic wild-type mice detected elevated concentrations of 3-chlorotyrosine, a characteristic end product of the myeloperoxidase system. Levels of 3-chlorotyrosine did not rise in the septic myeloperoxidase-deficient mice. Thus, myeloperoxidase seems to protect against sepsis in vivo by producing halogenating species. Surprisingly, levels of 3-bromotyrosine also were elevated in peritoneal fluid from septic wild-type mice and were markedly reduced in peritoneal fluid from septic myeloperoxidase-deficient mice. Furthermore, physiologic concentrations of bromide modulated the bactericidal effects of myeloperoxidase in vitro. It seems, therefore, that myeloperoxidase can use bromide as well as chloride to produce oxidants in vivo, even though the extracellular concentration of bromide is at least 1,000-fold lower than that of chloride. Thus, myeloperoxidase plays an important role in host defense against bacterial pathogens, and bromide might be a previously unsuspected component of this system.","pmid":"11593004","doi":"10.1073/pnas.211190298","url":"https://pubmed.ncbi.nlm.nih.gov/11593004/"},{"id":2613,"title":"Antioxidant properties of alpha-crystallin.","authors":"Manzanares, D; Bauby, C; de la Peña, R; Garcia, J C; Sanchez, R; Martinez, S; Romay, C H; López-Reconde, J L; Pino, E; Lissi, E A","year":2001,"date":"2001 Apr","journal":"Journal of protein chemistry","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"alpha-Crystallin is a major chaperone lens protein to which has been ascribed antioxidant functions. In the present work we have evaluated the antioxidant and free radical scavenging properties of bovine alpha-crystallin in a series of in vitro models: zimosan-induced, luminol-enhanced chemiluminescence response of polymorphonuclear leukocytes, the autoxidation of brain homogenate, bleaching of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)-derived radical cations, trapping of peroxyl radicals, and reactivity toward hypochloric acid. In all these systems, the reactivity of alpha-crystallin is higher than or similar to that of bovine serum albumin. It is concluded that, given the high concentrations of ol-crystallin in the lenses, its capacity to interact with free radicals and to remove hypochlorous acid could contribute to the maintenance of the lens functionality.","pmid":"11565898","doi":"10.1023/a:1010996528884","url":"https://pubmed.ncbi.nlm.nih.gov/11565898/"},{"id":2615,"title":"Endothelial dysfunction is induced by proinflammatory oxidant hypochlorous acid.","authors":"Zhang, C; Patel, R; Eiserich, J P; Zhou, F; Kelpke, S; Ma, W; Parks, D A; Darley-Usmar, V; White, C R","year":2001,"date":"2001 Oct","journal":"American journal of physiology. Heart and circulatory physiology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The myeloperoxidase (MPO)-derived oxidant hypochlorous acid (HOCl) plays a role in tissue injury under inflammatory conditions. The present study tests the hypothesis that HOCl decreases nitric oxide (NO) bioavailability in the vasculature of Sprague-Dawley rats. Aortic ring segments were pretreated with HOCl (1-50 microM) followed by extensive washing. Endothelium-dependent relaxation was then assessed by cumulative addition of acetylcholine (ACh) or the calcium ionophore A23187. HOCl treatment significantly impaired both ACh- and A23187-mediated relaxation. In contrast, endothelium-independent relaxation induced by sodium nitroprusside was unaffected. The inhibitory effect of HOCl on ACh-induced relaxation was reversed by exposure of ring segments to L-arginine but not D-arginine. In cellular studies, HOCl did not alter endothelial NO synthase (NOS III) protein or activity, but inhibited formation of the NO metabolites nitrate (NO3(-) and nitrite (NO2(-). The reduction in total NO metabolite production in bovine aortic endothelial cells was also reversed by addition of L-arginine. These data suggest that HOCl induces endothelial dysfunction via modification of L-arginine.","pmid":"11557534","doi":"10.1152/ajpheart.2001.281.4.H1469","url":"https://pubmed.ncbi.nlm.nih.gov/11557534/"},{"id":2616,"title":"Biofilm penetration and disinfection efficacy of alkaline hypochlorite and chlorosulfamates.","authors":"Stewart, P S; Rayner, J; Roe, F; Rees, W M","year":2001,"date":"2001 Sep","journal":"Journal of applied microbiology","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"AIMS: The purpose of this study was to compare the efficacy, in terms of bacterial biofilm penetration and killing, of alkaline hypochlorite (pH 11) and chlorosulfamate (pH 5.5) formulations. METHODS AND RESULTS: Two species biofilms of Pseudomonas aeruginosa and Klebsiella pneumoniae were grown by flowing a dilute medium over inclined stainless steel slides for 6 d. Microelectrode technology was used to measure concentration profiles of active chlorine species within the biofilms in response to treatment at a concentration of 1000 mg total chlorine l(-1). Chlorosulfamate formulations penetrated biofilms faster than did hypochlorite. The mean penetration time into approximately 1 mm-thick biofilms for chlorosulfamate (6 min) was only one-eighth as long as for the same concentration of hypochlorite (48 min). Chloride ion penetrated biofilms rapidly (5 min) with an effective diffusion coefficient in the biofilm that was close to the value for chloride in water. Biofilm bacteria were highly resistant to killing by both antimicrobial agents. Biofilms challenged with 1000 mg l(-1) alkaline hypochlorite or chlorosulfamate for 1 h experienced 0.85 and 1.3 log reductions in viable cell numbers, respectively. Similar treatment reduced viable numbers of planktonic bacteria to non-detectable levels (log reduction greater than 6) within 60 s. Aged planktonic and resuspended laboratory biofilm bacteria were just as susceptible to hypochlorite as fresh planktonic cells. CONCLUSION: Chlorosulfamate transport into biofilm was not retarded whereas hypochlorite transport clearly was retarded. Superior penetration by chlorosulfamate was hypothesized to be due to its lower capacity for reaction with constituents of the biofilm. Poor biofilm killing despite direct measurement of effective physical penetration of the antimicrobial agent into the biofilm demonstrates that bacteria in the biofilm are protected by some mechanism other than simple physical shielding by the biofilm matrix. SIGNIFICANCE AND IMPACT OF THE STUDY: This study lends support to the theory that the penetration of antimicrobial agents into microbial biofilms is controlled by the reactivity of the antimicrobial agent with biofilm components. The finding that chlorine-based biocides can penetrate, but fail to kill, bacteria in biofilms should motivate the search for other mechanisms of protection from killing by antimicrobial agents in biofilms.","pmid":"11556920","doi":"10.1046/j.1365-2672.2001.01413.x","url":"https://pubmed.ncbi.nlm.nih.gov/11556920/"},{"id":2618,"title":"15N chemically induced dynamic nuclear polarization during reaction of N-acetyl-L-tyrosine with the nitrating systems nitrite/hydrogen peroxide/horseradish peroxidase and nitrite/hypochloric acid.","authors":"Lehnig, M","year":2001,"date":"2001 Sep 15","journal":"Archives of biochemistry and biophysics","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"During reaction of N-acetyl-l-tyrosine with the nitrating system (15)NO(-)(2)/H(2)O(2)/HRP at pH 7.5, emission is observed in the (15)N NMR signals of 3-nitro-N-acetyl-l-tyrosine and the 1-nitrocyclohexa-2,5-dien-4-one derivative of N-acetyl-l-tyrosine. The occurrence of (15)N CIDNP proves the formation of radical pairs. The nitration products are formed by recombination of (15)NO(*)(2) and N-acetyl-l-tyrosinyl radicals Tyrac(*). The (15)N NMR signals of (15)NO(-)(2) and of (15)NO(-)(3) show enhanced absorption. The (15)N CIDNP effects are built up in radical pairs [(15)NO(*)(2), Tyrac(*)](F) formed by diffusive encounters of the radicals. Nuclear polarization is transferred into (15)NO(-)(2) and (15)NO(-)(3) by disproportionation reactions of (15)NO(*)(2) and by H abstraction of (15)NO(*)(2) from N-acetyl-l-tyrosine. If N-acetyl-l-tyrosine is not present, (15)NO(-)(3) does not show (15)N CIDNP, indicating that peroxynitrite is not formed as an intermediate during the reaction. Peroxynitrate is not formed either, which is indicated by the absence of (15)N CIDNP during reaction or a (15)N NMR signal after reaction. Emission also appears in nitrated tyrosine residues of bovine serum albumin during reaction of albumin with the (15)NO(-)(2)/H(2)O(2)/HRP system. Analogous but smaller effects are observed during reaction of the nitrating system (15)NO(-)(2)/HOCl with N-acetyl-l-tyrosine at pH 7.5, proving the radical character of this reaction, too. The (15)N CIDNP effects are weak because of the low yield of nitration products.","pmid":"11556811","doi":"10.1006/abbi.2001.2494","url":"https://pubmed.ncbi.nlm.nih.gov/11556811/"},{"id":2620,"title":"Chlorination of guanosine and other nucleosides by hypochlorous acid and myeloperoxidase of activated human neutrophils. Catalysis by nicotine and trimethylamine.","authors":"Masuda, M; Suzuki, T; Friesen, M D; Ravanat, J L; Cadet, J; Pignatelli, B; Nishino, H; Ohshima, H","year":2001,"date":"2001 Nov 2","journal":"The Journal of biological chemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Activated human neutrophils secrete myeloperoxidase, which generates HOCl from H2O2 and Cl(-). We have found that various (2'-deoxy)nucleosides react with HOCl to form chlorinated (2'-deoxy)nucleosides, including novel 8-chloro(2'-deoxy)guanosine, 5-chloro(2'-deoxy)cytidine, and 8-chloro(2'-deoxy)adenosine formed in yields of 1.6, 1.6, and 0.2%, respectively, when 0.5 mM nucleoside reacted with 0.5 mM HOCl at pH 7.4. The relative chlorination, oxidation, and nitration activities of HOCl, myeloperoxidase, and activated human neutrophils in the presence and absence of nitrite were studied by analyzing 8-chloro-, 8-oxo-7,8-dihydro-, and 8-nitro-guanosine, respectively, using guanosine as a probe. 8-Chloroguanosine was always more easily formed than 8-oxo-7,8-dihydro- or 8-nitro-guanosine. Using electrospray ionization tandem mass spectrometry, we show that several chlorinated nucleosides including 8-chloro(2'-deoxy)guanosine are formed following exposure of isolated DNA or RNA to HOCl. Micromolar concentrations of tertiary amines such as nicotine and trimethylamine dramatically enhanced chlorination of free (2'-deoxy)nucleosides and nucleosides in RNA by HOCl. As the G-463A polymorphism of the MPO gene, which strongly reduces myeloperoxidase mRNA expression, is associated with a reduced risk of lung cancer, chlorination damage of DNA /RNA and nucleosides by myeloperoxidase and its enhancement by nicotine may be important in the pathophysiology of human diseases associated with tobacco habits.","pmid":"11533049","doi":"10.1074/jbc.M102700200","url":"https://pubmed.ncbi.nlm.nih.gov/11533049/"},{"id":2625,"title":"Hypochlorite-induced damage to nucleosides: formation of chloramines and nitrogen-centered radicals.","authors":"Hawkins, C L; Davies, M J","year":2001,"date":"2001 Aug","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Stimulated monocytes and neutrophils generate hypochlorite (HOCl) via the release of the enzyme myeloperoxidase and hydrogen peroxide. HOCl is a key bactericidal agent, but can also damage host tissue. As there is a strong link between chronic inflammation and some cancers, we have investigated HOCl damage to DNA bases. We show that reaction of HOCl with the exocyclic -NH(2) groups of cytidine, adenosine, and guanosine, and the ring NH groups of all bases, yields chloramines (RNHCl/RR'NCl). These are the major initial products. Chloramine decay can be accelerated by UV light and metal ions, and these reactions, together with thermal decomposition, give rise to nucleoside-derived nitrogen-centered radicals. Evidence is presented for the rapid addition of pyrimidine-derived nitrogen-centered radicals to another parent molecule to give dimers. Experiments with nucleoside mixtures show that the propensity for radical formation is cytidine > adenosine = guanosine > uridine = thymidine. These data are inconsistent with the selectivity of HOCl attack and the stability of the resulting chloramines, but can be rationalized if chlorine transfer between bases is rapid and yields the most stable chloramine, with such transfer preceding radical formation. Thus, though thymidine is the major initial site of chloramine formation, rapid chlorine atom transfer generates cytidine and adenosine chloramines. These reactions rationalize the preferential formation of chlorinated cytidine and adenosine in DNA.","pmid":"11511181","doi":"10.1021/tx010071r","url":"https://pubmed.ncbi.nlm.nih.gov/11511181/"},{"id":2627,"title":"Reactive carbonyl formation by oxidative and non-oxidative pathways.","authors":"Adams, S; Green, P; Claxton, R; Simcox, S; Williams, M V; Walsh, K; Leeuwenburgh, C","year":2001,"date":"2001 Aug 1","journal":"Frontiers in bioscience : a journal and virtual library","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The spectrophotometric protein carbonyl assay is used as an indicator of protein damage by free radical reactions in vitro and in a variety of pathologies. We investigated model proteins and a variety of oxidative and non-oxidative reactions, as well as what effects hemoglobin, myoglobin, and cytochrome c might have on levels of protein carbonyls. We show that oxidative as well as non-oxidative mechanisms introduce carbonyl groups into proteins, providing a moiety for quantification with 2,4-dinitrophenylhydrazine (DNPH). Bovine serum albumin exposed to oxidative scenarios, such as hypochlorous acid, peroxynitrite, and metal-catalyzed oxidation exhibited variable, but increased levels of carbonyls. Other non-oxidative modification systems, in which proteins are incubated with various aldehydes, such as malondialdehyde, acrolein, glycolaldehyde, and glyoxal also generated significant amounts of carbonyls. Furthermore, purified myoglobin, hemoglobin, and cytochrome c show high absorbance at the same wavelengths as DNPH. The high levels observed are due to the innate absorbance of hemoglobin, myoglobin, and cytochrome c near the assay spectra of DNPH. These studies show that carbonyl content could be due to oxidative as well as non-oxidative mechanisms and that heme-containing compounds may effect carbonyl quantification.","pmid":"11487471","doi":"10.2741/adams","url":"https://pubmed.ncbi.nlm.nih.gov/11487471/"},{"id":2628,"title":"Vitamins C and E: missing links in preventing preterm premature rupture of membranes?","authors":"Woods, J R Jr; Plessinger, M A; Miller, R K","year":2001,"date":"2001 Jul","journal":"American journal of obstetrics and gynecology","category":"Materials & industrial applications","evidence":"Review","relevance":"Medium","abstract":"We propose that generation of reactive oxygen species may be a potentially reversible pathophysiologic pathway leading to preterm premature rupture of the membranes. Reactive oxygen species generated by the body's response to diverse insults such as infection, cigarette smoking, bleeding, or cocaine use can activate collagenolytic enzymes and impair fetal membrane integrity. Vitamin E, a lipid-soluble antioxidant, inhibits membrane-damaging effects of reactive oxygen species-induced lipid peroxidation. Vitamin C, a water-soluble antioxidant in plasma, stimulates and protects collagen synthesis while recycling vitamin E. Prior evidence shows that (1) damage by reactive oxygen species can impair fetal membrane integrity, (2) reduced midgestation levels of vitamin C are associated with preterm premature rupture of membranes, and (3) these vitamins can be safely and effectively absorbed and delivered to gestational tissues. Current prenatal vitamin preparations contain vitamins C and E in concentrations that are less than 1/3 and 1/10, respectively; these levels have been suggested for effective antioxidant protection. We hypothesize that increased dietary consumption or supplementation of vitamins C and E during pregnancy may reduce physiologically the risks of that portion of preterm premature rupture of membranes that is mediated by excessive or undamped peroxidation of fetal membranes. This hypothesis, if confirmed, should stimulate initiation of therapeutic trials to test the efficacy of enhanced supplementation with vitamins C and E during pregnancy to prevent preterm premature rupture of membranes.","pmid":"11483896","doi":"10.1067/mob.2001.115868","url":"https://pubmed.ncbi.nlm.nih.gov/11483896/"},{"id":2630,"title":"Treatment of arsenic in Bangladesh well water using a household co-precipitation and filtration system.","authors":"Meng, X; Korfiatis, G P; Christodoulatos, C; Bang, S","year":2001,"date":"2001 Aug","journal":"Water research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Laboratory and field tests were conducted to evaluate the effectiveness of a household filtration process and investigate the effects of phosphate and silicate on the removal of arsenic from Bangladesh groundwater by ferric hydroxides. Fe/As ratios of greater than 40 (mg/mg) were required to reduce arsenic to less than 50 microg/L in Bangladesh well water due to the presence of elevated phosphate and silicate concentrations. The household filtration process included co-precipitation of arsenic by adding a packet (approximately 2 g) of ferric and hypochlorite salts to 20 L of well water and subsequent filtration of the water through a bucket sand filter. A field demonstration study was performed to test the treatment system in seven households in Bangladesh in March and April 2000. Experimental results obtained from the participating families proved that the household treatment process removed arsenic from approximately 300 microg/L in the well water to less than 50 microg/L. The participating families liked this simple and affordable process and used it to prepare clean water for drinking and cooking. A larger scale field test is currently underway.","pmid":"11471680","doi":"10.1016/s0043-1354(01)00007-0","url":"https://pubmed.ncbi.nlm.nih.gov/11471680/"},{"id":2631,"title":"Characterization of the O(2)-evolving reaction catalyzed by [(terpy)(H2O)Mn(III)(O)2Mn(IV)(OH2)(terpy)](NO3)3 (terpy = 2,2':6,2\"-terpyridine).","authors":"Limburg, J; Vrettos, J S; Chen, H; de Paula, J C; Crabtree, R H; Brudvig, G W","year":2001,"date":"2001 Jan 24","journal":"Journal of the American Chemical Society","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The complex [(terpy)(H(2)O)Mn(III)(O)(2)Mn(IV)(OH(2))(terpy)](NO(3))(3) (terpy = 2,2':6,2' '-terpyridine) (1)catalyzes O(2) evolution from either KHSO(5) (potassium oxone) or NaOCl. The reactions follow Michaelis-Menten kinetics where V(max) = 2420 +/- 490 mol O(2) (mol 1)(-1) hr(-1) and K(M) = 53 +/- 5 mM for oxone ([1] = 7.5 microM), and V(max) = 6.5 +/- 0.3 mol O(2) (mol 1)(-1) hr(-1) and K(M) = 39 +/- 4 mM for hypochlorite ([1] = 70 microM), with first-order kinetics observed in 1 for both oxidants. A mechanism is proposed having a preequilibrium between 1 and HSO(5-) or OCl(-), supported by the isolation and structural characterization of [(terpy)(SO(4))Mn(IV)(O)(2)Mn(IV)(O(4)S)(terpy)] (2). Isotope-labeling studies using H(2)(18)O and KHS(16)O(5) show that O(2) evolution proceeds via an intermediate that can exchange with water, where Raman spectroscopy has been used to confirm that the active oxygen of HSO(5-) is nonexchanging (t(1/2) >> 1 h). The amount of label incorporated into O(2) is dependent on the relative concentrations of oxone and 1. (32)O(2):(34)O(2):(36)O(2) is 91.9 +/- 0.3:7.6 +/- 0.3:0.51 +/- 0.48, when [HSO(5-)] = 50 mM (0.5 mM 1), and 49 +/- 21:39 +/- 15:12 +/- 6 when [HSO(5-)] = 15 mM (0.75 mM 1). The rate-limiting step of O(2) evolution is proposed to be formation of a formally Mn(V)=O moiety which could then competitively react with either oxone or water/hydroxide to produce O(2). These results show that 1 serves as a functional model for photosynthetic water oxidation.","pmid":"11456544","doi":"10.1021/ja001090a","url":"https://pubmed.ncbi.nlm.nih.gov/11456544/"},{"id":2634,"title":"Chlorination of N-acetyltyrosine with HOCl, chloramines, and myeloperoxidase-hydrogen peroxide-chloride system.","authors":"Drabik, G; Naskalski, J W","year":2001,"date":"2001","journal":"Acta biochimica Polonica","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"N-acetyl-L-tyrosine (N-acTyr), with the alpha amine residue blocked by acetylation, can mimic the reactivity of exposed tyrosyl residues incorporated into polypeptides. In this study chlorination of N-acTyr residue at positions 3 and 5 in reactions with NaOCl, chloramines and the myeloperoxidase (MPO)-H2O2-Cl- chlorinating system were invesigated. The reaction of N-acTyr with HOCl/OCl- depends on the reactant concentration ratio employed. At the OCl-/N-acTyr (molar) ratio 1:4 and pH 5.0 the chlorination reaction yield is about 96% and 3-chlorotyrosine is the predominant reaction product. At the OCl-/N-acTyr molar ratio 1:1.1 both 3-chlorotyrosine and 3,5-dichlorotyrosine are formed. The yield of tyrosine chlorination depends also on pH, amounting to 100% at pH 5.5, 91% at pH 4.5 and 66% at pH 3.0. Replacing HOCl/OCl- by leucine/chloramine or alanine/chloramine in the reaction system, at pH 4.5 and 7.4, produces trace amount of 3-chlorotyrosine with the reaction yield of about 2% only. Employing the MPO-H2O2-Cl- chlorinating system at pH 5.4, production of a small amount of N-acTyr 3-chloroderivative was observed, but the reaction yield was low due to the rapid inactivation of MPO in the reaction system. The study results indicate that direct chlorination of tyrosyl residues which are not incorporated into the polypeptide structure occurs with excess HOCl/OCl- in acidic media. Due to the inability of the myeloperoxidase-H2O2-Cl- system to produce high enough HOCl concentrations, the MPO-mediated tyrosyl residue chlorination is not effective. Semistable amino-acid chloramines also appeared not effective as chlorine donors in direct tyrosyl chlorination.","pmid":"11440179","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/11440179/"},{"id":2637,"title":"Reaction of acylated homoserine lactone bacterial signaling molecules with oxidized halogen antimicrobials.","authors":"Borchardt, S A; Allain, E J; Michels, J J; Stearns, G W; Kelly, R F; McCoy, W F","year":2001,"date":"2001 Jul","journal":"Applied and environmental microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Oxidized halogen antimicrobials, such as hypochlorous and hypobromous acids, have been used extensively for microbial control in industrial systems. Recent discoveries have shown that acylated homoserine lactone cell-to-cell signaling molecules are important for biofilm formation in Pseudomonas aeruginosa, suggesting that biofouling can be controlled by interfering with bacterial cell-to-cell communication. This study was conducted to investigate the potential for oxidized halogens to react with acylated homoserine lactone-based signaling molecules. Acylated homoserine lactones containing a 3-oxo group were found to rapidly react with oxidized halogens, while acylated homoserine lactones lacking the 3-oxo functionality did not react. The Chromobacterium violaceum CV026 bioassay was used to determine the effects of such reactions on acylated homoserine lactone activity. The results demonstrated that 3-oxo acyl homoserine lactone activity was rapidly lost upon exposure to oxidized halogens; however, acylated homoserine lactones lacking the 3-oxo group retained activity. Experiments with the marine alga Laminaria digitata demonstrated that natural haloperoxidase systems are capable of mediating the deactivation of acylated homoserine lactones. This may illustrate a natural defense mechanism to prevent biofouling on the surface of this marine alga. The Chromobacterium violaceum activity assay illustrates that reactions between 3-oxo acylated homoserine lactone molecules and oxidized halogens do occur despite the presence of biofilm components at much greater concentrations. This work suggests that oxidized halogens may control biofilm not only via a cidal mechanism, but also by possibly interfering with 3-oxo acylated homoserine lactone-based cell signaling.","pmid":"11425738","doi":"10.1128/AEM.67.7.3174-3179.2001","url":"https://pubmed.ncbi.nlm.nih.gov/11425738/"},{"id":2638,"title":"Effects of rice seed surface sterilization with hypochlorite on inoculated Burkholderia vietnamiensis.","authors":"Miché, L; Balandreau, J","year":2001,"date":"2001 Jul","journal":"Applied and environmental microbiology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"When a combination of hydrogen peroxide and hypochlorite was used to surface sterilize rice seeds, a 10(2)- to 10(4)-fold decrease in CFU was observed during the first 15 h after inoculation of the rice rhizosphere organism Burkholderia vietnamiensis TVV75. This artifact could not be eliminated simply by rinsing the seeds, even thoroughly, with sterile distilled water. When growth resumed, a significant increase in the frequency of rifampin- and nalidixic acid-resistant mutants in the population was observed compared to the control without seeds. This phenomenon was a specific effect of hypochlorite; it was not observed with hydrogen peroxide alone. It was also not observed when the effect of hypochlorite was counteracted by sodium thiosulfate. We hypothesized that the hypochlorite used for disinfection reacted with the rice seed surface, forming a chlorine cover which was not removed by rinsing and generated mutagenic chloramines. We studied a set of rifampin- and nalidixic acid-resistant mutants obtained after seed surface sterilization. The corresponding rpoB and gyrA genes were amplified and sequenced to characterize the induced mutations. The mutations in five of seven nalidixic acid-resistant mutants and all of the rifampin-resistant mutants studied were found to correspond to single amino acid substitutions. Hypochlorite surface sterilization can thus be a source of artifacts when the initial bacterial colonization of a plant is studied.","pmid":"11425720","doi":"10.1128/AEM.67.7.3046-3052.2001","url":"https://pubmed.ncbi.nlm.nih.gov/11425720/"},{"id":2643,"title":"Effects of hypochlorite on cultured respiratory epithelial cells.","authors":"Kampf, C; Roomans, G M","year":2001,"date":"2001 May","journal":"Free radical research","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Neutrophils and eosinophils are involved in the pathogenesis of many respiratory diseases. The enzymes myeloperoxidase and eosinophil peroxidase catalyze the reaction of H2 O2 with Cl to produce the reactive oxygen species HOCl. Normal human bronchial epithelial (NHBE) cells were exposed to 0.18-0.90 mM HOCl for 48 h, and studied with immunohistochemical, metabolic and morphological studies. The ability of the cells to attach to each other and/or to the matrix was altered. Immunohistochemical studies showed a decreased amount of desmosomes and focal adhesion sites, although the morphology of the cells was not affected. The ability of the mitochondria to oxidize glucose was reduced. HOCl-exposed cells had an increased production of NO, probably by an increased activity of cNOS, due to increased intracellular Ca2+. The antioxidant N-acetylcysteine inhibited both the NO production and the effects of HOCl on glucose oxidation. The cNOS-inhibitor N-propyl-L-arginine inhibited HOCl-induced NO production. X-ray microanalysis showed an increase in the intracellular Na+ /K+ ratio, which indicates cell damage. In conclusion, exposure to HOCl results in cell detachment and metabolic alterations in normal human bronchial epithelial cells. Oxygen radicals could in part mediate the effects. Oxygen radicals could hence contribute to the observed epithelial damage in respiratory diseases.","pmid":"11378533","doi":"10.1080/10715760100300441","url":"https://pubmed.ncbi.nlm.nih.gov/11378533/"},{"id":2646,"title":"8-Nitroxanthine, an adduct derived from 2'-deoxyguanosine or DNA reaction with nitryl chloride.","authors":"Chen, H J; Chen, Y M; Wang, T F; Wang, K S; Shiea, J","year":2001,"date":"2001 May","journal":"Chemical research in toxicology","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"Activated phagocytic cells generate reactive nitrogen species, including nitryl chloride and peroxynitrite, for host defense against invading pathogens. It has been proposed that these reactive nitrogen species may cause DNA damage and thus contribute to the multistage carcinogenesis process associated with chronic infections and inflammation. Previous studies showed that peroxynitrite reacted with guanine, 2'-deoxyguanosine, or DNA forming 8-nitroguanine. We herein report formation of 8-nitroxanthine as the major nitration product in reactions of 2'-deoxyguanosine or calf thymus DNA with nitryl chloride produced by mixing nitrite with hypochlorous acid, and 8-nitroguanine was a minor product in these reactions. 8-Nitroxanthine was characterized by its NMR and laser desorption ionization mass spectra and by deamination of 8-nitroguanine. Formation of 8-nitroxanthine was also detected by xanthine reaction with various reactive nitrogen species, including nitryl chloride, peroxynitrite, nitronium tetrafluoroborate, and heated nitric and nitrous acid. The identity of 8-nitroxanthine in nitryl chloride-treated dG and DNA was confirmed by co-injection with synthetic 8-nitroxanthine and by its reduction to 8-aminoxanthine. Levels of 8-nitroxanthine and 8-nitroguanine in these reactions were quantified by reversed-phase HPLC with photodiode array detection. Once formed, 8-nitroxanthine was spontaneously removed from DNA with a half-life of 2 h at 37 degrees C and pH 7.4. Therefore, 8-nitroxanthine might be an important DNA lesion derived from reactive nitrogen species in vivo.","pmid":"11368552","doi":"10.1021/tx0002334","url":"https://pubmed.ncbi.nlm.nih.gov/11368552/"},{"id":2652,"title":"Inhibition of the myeloperoxidase chlorinating activity by non-steroidal anti-inflammatory drugs investigated with a human recombinant enzyme.","authors":"Nève, J; Parij, N; Moguilevsky, N","year":2001,"date":"2001 Apr 6","journal":"European journal of pharmacology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Non-steroidal anti-inflammatory drugs (NSAIDs) were investigated for their ability to affect the chlorinating activity of human myeloperoxidase and to scavenge HOCl, the main myeloperoxidase system product. Fourteen drugs representative of various NSAIDs families were tested with the chlorination of taurine used as a detection system. All were unable to inhibit taurine chlorination in a system without myeloperoxidase. In contrast, most of them induced a dose-dependent inhibition of the taurine chlorination mediated by a myeloperoxidase/H2O2/Cl- system. This took place at variable drug concentrations and IC50 were calculated. The inhibitory effect was therefore due to a direct interaction with the enzyme rather than to HOCl scavenging. A spectroscopic method used to measure the myeloperoxidase compound II lifetime in presence of the different drugs showed that all the drugs, which inhibited chlorination activity were able to induce accumulation of compound II. The extent of chlorinating activity inhibition (IC50) was inversely related to the duration of the block of enzyme in compound II form. This further demonstrates that myeloperoxidase is an interesting target for anti-inflammatory therapy. The recombinant myeloperoxidase used for the first time in this kind of study was as convenient for pharmacological purposes as the purified one.","pmid":"11301057","doi":"10.1016/s0014-2999(01)00895-0","url":"https://pubmed.ncbi.nlm.nih.gov/11301057/"},{"id":2653,"title":"Hypochlorous acid produced by the myeloperoxidase system of human phagocytes induces covalent cross-links between DNA and protein.","authors":"Kulcharyk, P A; Heinecke, J W","year":2001,"date":"2001 Mar 27","journal":"Biochemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Phagocytic oxidants have been implicated in tissue injury and oncogenesis, and their pathophysiological role in modifying nucleobases and amino acids has been widely explored. Their ability to cross-link proteins and DNA, however, has not been considered, even though reversible DNA-protein interactions are key to gene expression and to DNA replication and repair. In the current studies, we show that hypochlorous acid (HOCl), generated by the myeloperoxidase-hydrogen peroxide-chloride system of phagocytes, cross-links single-stranded DNA-binding protein (SSB) to single-stranded oligonucleotides. Exposure of SSB and a homopolymer of radiolabeled thymidine (dT(40)) to HOCl resulted in the formation of a radiolabeled band with slower mobility than the free oligonucleotide, as determined by denaturing polyacrylamide gel electrophoresis. This radiolabeled band did not appear if the reaction mixture was treated with protease or nuclease, indicating that it represents a covalent complex of DNA and protein. Oligonucleotides of adenosine and cytidine behaved similarly to the thymidine oligonucleotide, demonstrating that they are also capable of participating in the cross-linking reaction. The covalent complex of radiolabeled dT(40) and SSB was also generated by chloramines and the complete myeloperoxidase-hydrogen peroxide-chloride system. The enzymatic reaction required each component of the system and was inhibited by heme poisons and chloride-free conditions, implicating myeloperoxidase and HOCl. DNA-protein cross-links were generated in Escherichia coli exposed to HOCl, suggesting that double-stranded DNA is also a target for the reaction. These results indicate that long-lived chloramines and HOCl generated by myeloperoxidase can generate covalent DNA-protein cross-links that may contribute to the mutagenic and cytotoxic effects of phagocytes on microbial pathogens and host tissue.","pmid":"11297432","doi":"10.1021/bi001962l","url":"https://pubmed.ncbi.nlm.nih.gov/11297432/"},{"id":2654,"title":"Degradation of chlortoluron in water disinfection processes: a kinetic study.","authors":"Losito, I; Zambonin, C G; Palmisano, F","year":2000,"date":"2000 Dec","journal":"Journal of environmental monitoring : JEM","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The kinetics of the reaction between chlortoluron, a phenylurea herbicide [N'-(2-hydroxy-4-methyl-5-chlorophenyl)-N,N-dimethylurea], and hypochlorite, the active species in water disinfection processes involving chlorine, were investigated by HPLC-UV and HPLC-electrospray ionisation mass spectrometry (HPLC-ESI-MS). In particular, the concentrations of the main chlortoluron by-products were monitored as a function of time by HPLC-ESI-MS and a kinetic model was developed to fit the relevant curves. The results showed that chlortoluron degradation starts with two parallel pathways, namely, chlorination and hydroxylation of the aromatic ring, which are then followed by consecutive chlorination reactions, and after almost 2 weeks by ring opening and partial mineralisation, as confirmed by head-space solid-phase microextraction gas chromatography-MS (SPME-GC-MS) and total organic carbon (TOC) measurements. Kinetic constants for the first reactions of the overall process, under pseudo-first-order conditions (hypochlorite excess), were estimated by a fitting procedure.","pmid":"11296745","doi":"10.1039/b005673l","url":"https://pubmed.ncbi.nlm.nih.gov/11296745/"},{"id":2655,"title":"Biofilm formation by salmonella spp. on food contact surfaces and their sensitivity to sanitizers.","authors":"Joseph, B; Otta, S K; Karunasagar, I; Karunasagar, I","year":2001,"date":"2001 Mar 20","journal":"International journal of food microbiology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Biofilm formation by two poultry isolates of Salmonella on three commonly used food contact surfaces viz plastic, cement and stainless steel were studied. Biofilm formation of both the isolates showed a similar trend with the highest density being on plastic followed by cement and steel. Salmonella weltevreden formed biofilm with a cell density of 3.4 x 10(7), 1.57 x 10(6) and 3 x 10(5) cfu/cm2 on plastic, cement and steel respectively while Salmonella FCM 40 biofilm on plastic, cement and steel were of the order of 1.2 x 10(7), 4.96 x 10(6) and 2.23 x 10(5) cfu/cm2 respectively. The sensitivity of the biofilm cells grown on these surfaces to different levels of two sanitizers namely hypochlorite and iodophor for varying exposure times was studied. Biofilm cells offered greater resistance when compared to their planktonic counterparts. Such biofilm cells in a food processing unit are not usually removed by the normal cleaning procedure and therefore could be a source of contamination of foods coming in contact with such surfaces.","pmid":"11294359","doi":"10.1016/s0168-1605(00)00466-9","url":"https://pubmed.ncbi.nlm.nih.gov/11294359/"},{"id":2658,"title":"Enhanced antioxidant activity after chlorination of quercetin by hypochlorous acid.","authors":"Binsack, R; Boersma, B J; Patel, R P; Kirk, M; White, C R; Darley-Usmar, V; Barnes, S; Zhou, F; Parks, D A","year":2001,"date":"2001 Mar","journal":"Alcoholism, clinical and experimental research","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"BACKGROUND: Several epidemiological studies indicate that moderate consumption of red wine decreases both the incidence and mortality associated with cardiovascular disease. Quercetin and rutin (quercetin-3-rutinoside) are polyphenols present in relatively large concentrations in red wine and may play a role in this cardioprotective phenomenon. The precise mechanisms of cardioprotection remain unclear but may involve the action of these polyphenols as antioxidants, which attenuate the tissue injury that results from the production of proinflammatory oxidants such as hypochlorous acid (HOCl). METHODS: To study the interaction of these polyphenols with proinflammatory oxidants, we mixed quercetin or rutin with HOCl (0-150 microM) and analyzed the reaction products by high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance. RESULTS: Stable mono- and dichlorinated derivates were detected for both quercetin and the glycoside derivative, rutin, which suggests that both the conjugated and unconjugated forms of quercetin reacted with HOCl similarly. Chlorination of quercetin occurred only at two sites, and the derivates (6-chloroquercetin, 6,8-dichloroquercetin) were more potent antioxidants toward oxidative modification of low-density lipoproteins and ABTS radical formation than the unmodified form. CONCLUSIONS: These data suggest that under certain pathological conditions in vivo (e.g., inflammation), flavonols may be converted to chlorinated derivates, which exhibit an enhanced antioxidant potential and thereby play a role in cardioprotection.","pmid":"11290856","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/11290856/"},{"id":2662,"title":"Protection of erythrocytes by the macrophage synthesized antioxidant 7,8 dihydroneopterin.","authors":"Gieseg, S P; Maghzal, G; Glubb, D","year":2001,"date":"2001 Feb","journal":"Free radical research","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Neopterin and the reduced form, 7,8-dihydroneopterin (78NP) are pteridines released from macrophages when stimulated with gamma-interferon in vivo. The role of 78NP in inflammatory response is unknown though neopterin has been used clinically as a marker of immune cell activation, due to its very fluorescent nature. Using red blood cells as a cellular model, we demonstrated that micromolar concentrations can inhibit or reduce red blood cell haemolysis induced by 2,2'-azobis(amidinopropane)dihydrochloride (AAPH), hydrogen peroxide, or hypochlorite. One hundred microM 78NP prevented HOCl haemolysis using a high HOCl concentration of 5 micromole HOCl/10(7) RBC. Fifty microM 78NP reduced the haemolysis caused by 2 mM hydrogen peroxide by 39% while the same 78NP concentration completely inhibited haemolysis induced by 2.5 mM AAPH. Lipid peroxidation levels measured as HPLC-TBARS were not affected by addition of 78NP. There was no correlation between lipid oxidation and cell haemolysis suggesting that lipid peroxidation is not essential for haemolysis. Conjugated diene measurements taken after 6 and 12 hour exposure to hydrogen peroxide support the TBARS data. Gel electrophoresis of cell membrane proteins indicated 78NP might inhibit protein damage. Using dityrosine as an indicator of protein damage, we demonstrated 200 microM 78NP reduced dityrosine formation in H(2) O(2) /Fe(++) treated red blood cell ghosts by 30%. HPLC analysis demonstrated a direct reaction between 78NP and all three oxidants. Two mM hydrogen peroxide oxidised 119 nM of 78NP per min while 1 mM AAPH only oxidised 50 nM 78NP/min suggesting that 78NP inhibition of haemolysis is not due to 78NP scavenging the primary initiating reactants. In contrast, the reaction between HOCl and 78NP was near instant. AAPH and hydrogen peroxide oxidised 78NP to 7,8-dihydroxanthopterin while hypochlorite oxidation produced neopterin. The cellular antioxidant properties of 78NP suggest it may have a role in protecting immune cells from free radical damage during inflammation.","pmid":"11264890","doi":"10.1080/10715760100300121","url":"https://pubmed.ncbi.nlm.nih.gov/11264890/"},{"id":2663,"title":"Macrophage myeloperoxidase regulation by granulocyte macrophage colony-stimulating factor in human atherosclerosis and implications in acute coronary syndromes.","authors":"Sugiyama, S; Okada, Y; Sukhova, G K; Virmani, R; Heinecke, J W; Libby, P","year":2001,"date":"2001 Mar","journal":"The American journal of pathology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Inflammation and oxidative stress contribute to the pathogenesis of many human diseases including atherosclerosis. Advanced human atheroma contains high levels of the enzyme myeloperoxidase that produces the pro-oxidant species, hypochlorous acid (HOCl). This study documents increased numbers of myeloperoxidase-expressing macrophages in eroded or ruptured plaques causing acute coronary syndromes. In contrast, macrophages in human fatty streaks contain little or no myeloperoxidase. Granulocyte macrophage colony-stimulating factor, but not macrophage colony-stimulating factor, selectively regulates the ability of macrophages to express myeloperoxidase and produce HOCl in vitro. Moreover, myeloperoxidase-positive macrophages in plaques co-localized with granulocyte macrophage colony-stimulating factor. Pro-inflammatory stimuli known to be present in human atherosclerotic plaque, including CD40 ligand, lysophosphatidylcholine, or cholesterol crystals, could induce release of myeloperoxidase from HOCl production by macrophages in vitro. HOCl-modified proteins accumulated at ruptured or eroded sites of human coronary atheroma. These results identify granulocyte macrophage colony-stimulating factor as an endogenous regulator of macrophage myeloperoxidase expression in human atherosclerosis and support a particular role for the myeloperoxidase-expressing macrophages in atheroma complication and the acute coronary syndromes.","pmid":"11238037","doi":"10.1016/S0002-9440(10)64036-9","url":"https://pubmed.ncbi.nlm.nih.gov/11238037/"},{"id":2669,"title":"Increased atherosclerosis in myeloperoxidase-deficient mice.","authors":"Brennan, M L; Anderson, M M; Shih, D M; Qu, X D; Wang, X; Mehta, A C; Lim, L L; Shi, W; Hazen, S L; Jacob, J S; Crowley, J R; Heinecke, J W; Lusis, A J","year":2001,"date":"2001 Feb","journal":"The Journal of clinical investigation","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Myeloperoxidase (MPO), a heme enzyme secreted by activated phagocytes, generates an array of oxidants proposed to play critical roles in host defense and local tissue damage. Both MPO and its reaction products are present in human atherosclerotic plaque, and it has been proposed that MPO oxidatively modifies targets in the artery wall. We have now generated MPO-deficient mice, and show here that neutrophils from homozygous mutants lack peroxidase and chlorination activity in vitro and fail to generate chlorotyrosine or to kill Candida albicans in vivo. To examine the potential role of MPO in atherosclerosis, we subjected LDL receptor-deficient mice to lethal irradiation, repopulated their marrow with MPO-deficient or wild-type cells, and provided them a high-fat, high-cholesterol diet for 14 weeks. White cell counts and plasma lipoprotein profiles were similar between the two groups at sacrifice. Cross-sectional analysis of the aorta indicated that lesions in MPO-deficient mice were about 50% larger than controls. Similar results were obtained in a genetic cross with LDL receptor-deficient mice. In contrast to advanced human atherosclerotic lesions, the chlorotyrosine content of aortic lesions from wild-type as well as MPO-deficient mice was essentially undetectable. These data suggest an unexpected, protective role for MPO-generated reactive intermediates in murine atherosclerosis. They also identify an important distinction between murine and human atherosclerosis with regard to the potential involvement of MPO in protein oxidation.","pmid":"11181641","doi":"10.1172/JCI8797","url":"https://pubmed.ncbi.nlm.nih.gov/11181641/"},{"id":2672,"title":"Reactions of hypochlorous acid with tyrosine and peptidyl-tyrosyl residues give dichlorinated and aldehydic products in addition to 3-chlorotyrosine.","authors":"Fu, S; Wang, H; Davies, M; Dean, R","year":2000,"date":"2000 Apr 14","journal":"The Journal of biological chemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"The toxicity of hypochlorous acid (HOCl) generated from activated neutrophils has been associated with several pathological processes such as atherosclerosis. Formation of 3-chlorotyrosine (Cl-Tyr) has been used as a marker for assessing the involvement of HOCl in such processes. In this study, we aimed to investigate the formation of Cl-Tyr from reaction of HOCl with tyrosine (both free and peptide-bound) and the fate of Cl-Tyr under such conditions. Tyrosine, N-acetyltyrosine, bovine serum albumin, and human low density lipoproteins were incubated with a range of reagent hypochlorite concentrations for varying periods in 10 mM phosphate buffer (pH 7.4) at 22 degrees C. The reaction products, and several biological samples, were hydrolyzed (in the case of proteins), isolated, and purified by high pressure liquid chromatography and characterized or quantitated by mass spectrometry and NMR. A significant amount of 3,5-dichlorotyrosine (diCl-Tyr) was obtained from the bovine serum albumin, low density lipoprotein, and some biological samples, in addition to Cl-Tyr, indicating that Cl-Tyr competes effectively for HOCl even when tyrosine is present in great excess. Cl-Tyr and diCl-Tyr were also formed from free tyrosine but then reacted further with HOCl. This finding differs from a claim in the literature that Cl-Tyr was not formed in such a system. The further reaction products of Cl-Tyr and diCl-Tyr with HOCl were elucidated as their corresponding mono- and dichlorinated 4-hydroxyphenylacetaldehydes. These results indicate the importance of assessing other products of HOCl action in addition to Cl-Tyr.","pmid":"10753880","doi":"10.1074/jbc.275.15.10851","url":"https://pubmed.ncbi.nlm.nih.gov/10753880/"},{"id":2674,"title":"Effect of electrolyzed water on wound healing.","authors":"Yahagi, N; Kono, M; Kitahara, M; Ohmura, A; Sumita, O; Hashimoto, T; Hori, K; Ning-Juan, C; Woodson, P; Kubota, S; Murakami, A; Takamoto, S","year":2000,"date":"2000 Dec","journal":"Artificial organs","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"Electrolyzed water accelerated the healing of full-thickness cutaneous wounds in rats, but only anode chamber water (acid pH or neutralized) was effective. Hypochlorous acid (HOCl), also produced by electrolysis, was ineffective, suggesting that these types of electrolyzed water enhance wound healing by a mechanism unrelated to the well-known antibacterial action of HOCl. One possibility is that reactive oxygen species, shown to be electron spin resonance spectra present in anode chamber water, might trigger early wound healing through fibroblast migration and proliferation.","pmid":"11121980","doi":"10.1046/j.1525-1594.2000.06557-3.x","url":"https://pubmed.ncbi.nlm.nih.gov/11121980/"},{"id":2677,"title":"Production of brominating intermediates by myeloperoxidase. A transhalogenation pathway for generating mutagenic nucleobases during inflammation.","authors":"Henderson, J P; Byun, J; Williams, M V; Mueller, D M; McCormick, M L; Heinecke, J W","year":2001,"date":"2001 Mar 16","journal":"The Journal of biological chemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The existence of interhalogen compounds was proposed more than a century ago, but no biological roles have been attributed to these highly oxidizing intermediates. In this study, we determined whether the peroxidases of white blood cells can generate the interhalogen gas bromine chloride (BrCl). Myeloperoxidase, the heme enzyme secreted by activated neutrophils and monocytes, uses H2O2 and Cl(-) to produce HOCl, a chlorinating intermediate. In contrast, eosinophil peroxidase preferentially converts Br(-) to HOBr. Remarkably, both myeloperoxidase and eosinophil peroxidase were able to brominate deoxycytidine, a nucleoside, and uracil, a nucleobase, at plasma concentrations of Br(-) (100 microM) and Cl(-) (100 mM). The two enzymes used different reaction pathways, however. When HOCl brominated deoxycytidine, the reaction required Br(-) and was inhibited by taurine. In contrast, bromination by HOBr was independent of Br(-) and unaffected by taurine. Moreover, taurine inhibited 5-bromodeoxycytidine production by the myeloperoxidase-H2O2-Cl(-)- Br(-) system but not by the eosinophil peroxidase-H2O2-Cl(-)-Br(-) system, indicating that bromination by myeloperoxidase involves the initial production of HOCl. Both HOCl-Br(-) and the myeloperoxidase-H2O2-Cl(-)-Br(-) system generated a gas that converted cyclohexene into 1-bromo-2-chlorocyclohexane, implicating BrCl in the reaction. Moreover, human neutrophils used myeloperoxidase, H2O2, and Br(-) to brominate deoxycytidine by a taurine-sensitive pathway, suggesting that transhalogenation reactions may be physiologically relevant. 5-Bromouracil incorporated into nuclear DNA is a well known mutagen. Our observations therefore raise the possibility that transhalogenation reactions initiated by phagocytes provide one pathway for mutagenesis and cytotoxicity at sites of inflammation.","pmid":"11096071","doi":"10.1074/jbc.M005379200","url":"https://pubmed.ncbi.nlm.nih.gov/11096071/"},{"id":2678,"title":"Hair-discoloration of Japanese elite swimmers.","authors":"Nanko, H; Mutoh, Y; Atsumi, R; Kobayashi, Y; Ikeda, M; Yoshikawa, N; Fukuda, S; Kawa, Y; Mizoguchi, M","year":2000,"date":"2000 Oct","journal":"The Journal of dermatology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"To understand hair-discoloration in relation to swimming, we examined sixty-seven elite swimmers of the Japan National Swimming Team and fifty-four, age-matched subjects as controls. The incidence of hair discoloration (61%) in the swimmers' group was significantly higher than that in controls (0%) (p<0.0001). Interestingly, surface damage of the nail plates coexisted in the swimmers with the scalp-hair discoloration. The hairs picked from the eight swimmers and two age-matched individuals as controls were examined by electron microscope (EM) and EM X-ray microanalyzer. The swimmers' discolored, golden hair revealed complete disappearance of hair cuticle both by scanning EM (SEM) and transmission EM (TEM). The quantity of melanosomes in the cortex decreased, and their diameter was smaller than that of controls. In addition, irregularly shaped melanosomes with variable electron density and less electron-dense melanosomes with white haloes were frequently observed in the swimmers' golden hair. The X-ray elemental spectrograph by SEM revealed that the content of sulfur in all the swimmers' discoloured hair was lower than that in the normal controls and that the content of chlorine in the male swimmers' discoloured hair was higher than that in the female swimmers and the normal controls. The X-ray elemental microanalysis by TEM focused on melanosomes in the cortex of the cross section and detected elemental chlorine in all swimmers' golden hairs. It did not detect any element in the control hairs. The 14C-tyrosine uptake test of hairbulbs found no significant difference between the swimmers and the normal controls. These findings suggest that hair discoloration was mainly due to cuticle damage by friction with water. Hypochlorous acid in the swimming pool water can penetrate to the hair cortex through the cuticle. It can oxidize and degenerate melanosomes there.","pmid":"11092265","doi":"10.1111/j.1346-8138.2000.tb02243.x","url":"https://pubmed.ncbi.nlm.nih.gov/11092265/"},{"id":2679,"title":"Inflammatory properties of IgG modified by oxygen radicals and peroxynitrite.","authors":"Uesugi, M; Yoshida, K; Jasin, H E","year":2000,"date":"2000 Dec 1","journal":"Journal of immunology (Baltimore, Md. : 1950)","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"In inflammatory arthritis, there is evidence indicating that the affected tissues produce large amounts of oxygen-free radicals and NO. Herein, we examine the biologic effects of exposure of IgG to hypochlorous acid (HOCl) and peroxynitrite (ONOO). The concentrations of IgG modified by chlorination and nitrosation were measured in synovial fluids from inflammatory and noninflammatory arthritis. Human IgG was exposed to increasing concentrations of HOCl and ONOO, and the resulting products were tested for complement component binding; binding to FcgammaRI; activation of polymorphonuclear neutrophils; effect on the Ab-combining site of Abs; and in vivo inflammatory activity in a rabbit model of acute arthritis. Rheumatoid synovial fluids contained significantly greater concentrations of nitrosated and chlorinated IgG compared with ostearthritic specimens. In vitro exposure of human IgG to HOCl and ONOO resulted in a concentration-dependent decrease in C3 and C1q fixation. The decrease in Fc domain-dependent biologic functions was confirmed by competitive binding studies to the FcgammaRI of U937 cells. HOCl-treated IgG monomer was 10 times less effective in competing for binding compared with native IgG, and ONOO-treated IgG was 2.5 times less effective. The modified IgGs were also ineffective in inducing synthesis of H(2)O(2) by human PMN. The Ag-binding domains of IgG also showed a concentration-dependent decrease in binding to Ag. The ability of the modified IgGs to induce acute inflammation in rabbit knees decreased 20-fold as gauged by the intensity of the inflammatory cell exudates. These studies clarify the modulating role of biological oxidants in inflammatory processes in which Ag-autoantibody reactions and immune complex pathogenesis may play an important role.","pmid":"11086095","doi":"10.4049/jimmunol.165.11.6532","url":"https://pubmed.ncbi.nlm.nih.gov/11086095/"},{"id":2680,"title":"Improvement in bioreactor productivities using free radicals: HOCl-induced overproduction of xanthan gum from Xanthomonas campestris and its mechanism.","authors":"Rao, Y M; Sureshkumar, G K","year":2001,"date":"2001 Jan 5","journal":"Biotechnology and bioengineering","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Free-radical induction has been employed as a novel strategy to improve bioreactor productivity and, more specifically, the quality and productivity of xanthan gum from Xanthomonas campestris cultures. A 210% increase in xanthan yield and a 20% increase in viscosity (quality) resulted from HOCl (oxidant) treatment. The acetate mass fraction in xanthan gum decreased by 42% and its pyruvate mass fraction increased by 63% as a result of HOCl treatment. The growth rate was almost unaffected by HOCl treatment. A hypothesis to explain the mechanism of xanthan gum overproduction by free-radical induction has been formulated. The significant aspects of the hypothesis, such as SoxS protein binding to the promoter region of the gum gene and the consequent increase in mRNA concentrations, have been experimentally verified.","pmid":"11084595","doi":"10.1002/1097-0290(20010105)72:1<62::aid-bit9>3.0.co;2-9","url":"https://pubmed.ncbi.nlm.nih.gov/11084595/"},{"id":2681,"title":"Ultraviolet spectrophotometric characterization and bactericidal properties of electrolyzed oxidizing water as influenced by amperage and pH.","authors":"Len, S V; Hung, Y C; Erickson, M; Kim, C","year":2000,"date":"2000 Nov","journal":"Journal of food protection","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"To identify the primary component responsible in electrolyzed oxidizing (EO) water for inactivation, this study determined the concentrations of hypochlorous acid (HOCl) and hypochlorite ions (OCl-) and related those concentrations to the microbicidal activity of the water. The ultraviolet absorption spectra were used to determine the concentrations of HOCl and OCl- in EO water and the chemical equilibrium of these species with change in pH and amperage. EO water generated at higher amperage contained a higher chlorine concentration. The maximum concentration of HOCl was observed around pH 4 where the maximum log reduction (2.3 log10 CFU/ml) of Bacillus cereus F4431/73 vegetative cells also occurred. The high correlation (r = 0.95) between HOCl concentrations and bactericidal effectiveness of EO water supports HOCl's role as the primary inactivation agent. Caution should be taken with standard titrimetric methods for measurement of chlorine as they cannot differentiate the levels of HOCl present in EO water of varying pHs.","pmid":"11079696","doi":"10.4315/0362-028x-63.11.1534","url":"https://pubmed.ncbi.nlm.nih.gov/11079696/"},{"id":2684,"title":"Environmental control to reduce transmission of Clostridium difficile.","authors":"Mayfield, J L; Leet, T; Miller, J; Mundy, L M","year":2000,"date":"2000 Oct","journal":"Clinical infectious diseases : an official publication of the Infectious Diseases Society of America","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Restrictive antibiotic policies and infection control measures have been shown to reduce the incidence of Clostridium difficile-associated diarrhea (CDAD) among hospitalized patients. To date, the role of environmental disinfectants in reducing nosocomial CDAD rates has not been well studied. In a before-and-after intervention study, patients in 3 units were evaluated to determine if unbuffered 1:10 hypochlorite solution is effective as an environmental disinfectant in reducing the incidence of CDAD. Among 4252 patients, the incidence rate of CDAD for bone marrow transplant patients decreased significantly, from 8.6 to 3.3 cases per 1000 patient-days (hazard ratio, 0.37; 95% confidence interval, 0.19-0.74), after the environmental disinfectant was switched from quaternary ammonium to 1:10 hypochlorite solution in the rooms of patients with CDAD. Reverting later to quaternary ammonium solution increased the CDAD rate to 8.1 cases per 1000 patient-days. No reduction in CDAD rates was seen among neurosurgical intensive care unit and general medicine patients, for whom baseline rates were 3.0 and 1.3 cases per 1000 patient-days, respectively. Unbuffered 1:10 hypochlorite solution is effective in decreasing patients' risk of developing CDAD in areas where CDAD is highly endemic. Presumed mechanisms include reducing the environmental burden and the potential for C. difficile transmission among susceptible patients.","pmid":"11049782","doi":"10.1086/318149","url":"https://pubmed.ncbi.nlm.nih.gov/11049782/"},{"id":2689,"title":"Relative reactivity of lysine and other peptide-bound amino acids to oxidation by hypochlorite.","authors":"Nightingale, Z D; Lancha, A H Jr; Handelman, S K; Dolnikowski, G G; Busse, S C; Dratz, E A; Blumberg, J B; Handelman, G J","year":2000,"date":"2000 Sep 1","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Antibacterial and inflammatory responses of neutrophils and macrophages produce hypochlorite as a major oxidant. Numerous side chains of amino acids found in extracellular proteins can be modified by hypochlorite, including His, Arg, Tyr, Lys, Trp, and Met. We studied the relative reactivity of each of these amino acid residues in short N-blocked peptides, where other residues in the peptide were highly resistant to hypochlorite attack. Hypochlorite treatment led to modified peptides in each case, which were detected by changes in retention on reversed-phase HPLC. A distinct single product, consuming two equivalents of hypochlorite per equivalent of peptide, was obtained from the Lys-containing peptides. UV spectroscopy, nuclear magnetic resonance (NMR), and electrospray/mass spectroscopy identified this product as the dichloramine at the epsilon-amino group of the Lys side chain. The dichloramine at Lys did not decompose to form a detectable amount of carbonyl reactive with dinitrophenylhydrazine. The dichloramine at Lys did however quantitatively revert back to Lys during HCl digestion of the tetrapeptide for amino acid analysis, with simultaneous modification of the adjacent Phe residue. The formation of the dichloramine at Lys was not blocked by peptides or acetylated amino acids that contained Tyr, His, or Arg. In contrast, the presence of equimolar Met-containing peptide, or N-Acetyl-Trp, both inhibited the formation of the dichloramine at Lys. Thus, Met and Trp side chains of proteins might be able to protect Lys from chloramine formation under some circumstances, but this interpretation must consider that Met and Trp are typically found in relatively inaccessible hydrophobic sites, whereas lysine is typically exposed on the protein surface. The hierarchy of amino acid reactivities examined here will aid in the prediction of residues in biological samples most likely to be modified by hypochlorite.","pmid":"11020664","doi":"10.1016/s0891-5849(00)00262-8","url":"https://pubmed.ncbi.nlm.nih.gov/11020664/"},{"id":2694,"title":"Mechanism of reaction of myeloperoxidase with hydrogen peroxide and chloride ion.","authors":"Furtmüller, P G; Obinger, C; Hsuanyu, Y; Dunford, H B","year":2000,"date":"2000 Oct","journal":"European journal of biochemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"The reaction of myeloperoxidase compound I (MPO-I) with chloride ion is widely assumed to produce the bacterial killing agent after phagocytosis. Two values of the rate constant for this important reaction have been published previously: 4.7 x 106 M-1.s-1 measured at 25 degrees C [Marquez, L.A. and Dunford, H.B. (1995) J. Biol. Chem. 270, 30434-30440], and 2.5 x 104 M-1.s-1 at 15 degrees C [Furtmüller, P.G., Burner, U. & Obinger, C. (1998) Biochemistry 37, 17923-17930]. The present paper is the result of a collaboration of the two groups to resolve the discrepancy in the rate constants. It was found that the rate constant for the reaction of compound I, generated from myeloperoxidase (MPO) and excess hydrogen peroxide with chloride, decreased with increasing chloride concentration. The rate constant published in 1995 was measured over a lower chloride concentration range; the 1998 rate constant at a higher range. Therefore the observed conversion of compound I to native enzyme in the presence of hydrogen peroxide and chloride ion cannot be attributed solely to the single elementary reaction MPO-I + Cl- --> MPO + HOCl. The simplest mechanism for the overall reaction which fit the experimental data is the following: MPO+H2O2 &rlarr;k-1k1 MPO-I+H2O MPO-I+Cl- &rlarr;k-2k2 MPO-I-Cl- MPO-I-Cl- -->k3 MPO+HOCl where MPO-I-Cl- is a chlorinating intermediate. We can now say that the 1995 rate constant is k2 and the corresponding reaction is rate-controlling at low [Cl-]. At high [Cl-], the reaction with rate constant k3 is rate controlling. The 1998 rate constant for high [Cl-] is a composite rate constant, approximated by k2k3/k-2. Values of k1 and k-1 are known from the literature. Results of this study yielded k2 = 2.2 x 106 M-1.s-1, k-2 = 1.9 x 105 s-1 and k3 = 5.2 x 104 s-1. Essentially identical results were obtained using human myeloperoxidase and beef spleen myeloperoxidase.","pmid":"10998045","doi":"10.1046/j.1432-1327.2000.01491.x","url":"https://pubmed.ncbi.nlm.nih.gov/10998045/"},{"id":2695,"title":"Dissociation of DNA double strand by hypohalous acids.","authors":"Shishido, N; Nakamura, S; Nakamura, M","year":2000,"date":"2000","journal":"Redox report : communications in free radical research","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Calf thymus DNA was treated with authentic HOCl, and hypohalous acid-generating systems. This caused a decrease in fluorescence of ethidium-DNA complexes when ethidium bromide was subsequently added to the DNA. The fluorescence continued to decrease up to 30 min after adding HOCl. Loss in fluorescence was proportional to the concentration of HOCl and was complete when a 3-fold excess of HOCl was added to the DNA. No significant decrease in the fluorescence was observed when the chlorination was carried out in the presence of a concentration of monochlorodimedone (MCD) equivalent to that of HOCl. MCD is known to react stoichiometrically with HOCl. The decrease in fluorescence was completely inhibited by H2O2, ascorbate and glutathione (GSH). We have estimated the rate constant for the reaction of HOCl with H2O, to be 1-2 x 10(5) M(-1)s(-1). When compared with authentic HOCl, HOCl-generating systems (Cl + H2O2 + MPO or chloroperoxidase) were found to be inefficient in damaging DNA. This result most likely arises because the rate constant for reaction of HOCl with H2O2 is about 1000-fold faster than that for the reaction with DNA. HOBr and HOI generating systems also had a limited ability to damage DNA. We conclude that good chlorine acceptors and antioxidants protect DNA from hypohalous acid-induced oxidative damage.","pmid":"10994880","doi":"10.1179/135100000101535690","url":"https://pubmed.ncbi.nlm.nih.gov/10994880/"},{"id":2700,"title":"Kinetics of chlorination of monochlorodimedone by myeloperoxidase.","authors":"Jerlich, A; Tschabuschnig, S; Fabjan, J S; Schaur, R J","year":2000,"date":"2000","journal":"International journal of clinical & laboratory research","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The phagocyte-derived enzyme myeloperoxidase has been recently implicated in the pathogenesis of atherosclerosis, because it catalyzes the reaction of hydrogen peroxide with chloride ions to give the highly toxic oxidant hypochlorous acid. The aim of this study was to determine the dependence of this reaction on the concentration of hydrogen peroxide and of the enzyme by means of the photometric monochlorodimedone assay. The initial rate of hypochlorous acid formation increased less than proportionally with increasing myeloperoxidase concentrations. Variation of the concentration of hydrogen peroxide had a biphasic effect, with an optimal concentration of hydrogen peroxide. Above this concentration enzyme destruction is apparently predominant. The progress curves of hypochlorous acid formation showed two distinct maxima. It was concluded that hypochlorous acid not only reacts with monochlorodimedone but also with the amino groups of myeloperoxidase to form intermediary chloramines that may further chlorinate monochlorodimedone. This was supported by the kinetics in the presence of the amino compound glycine, a competitive substrate for chlorination by hypochlorous acid. In the presence of high concentrations of glycine the progress curve rises continuously, yielding a greatly increased concentration of chlorinating species, either hypochlorous acid or chloramines. We concluded that glycine protects myeloperoxidase against hypochlorous acid-induced self-destruction.","pmid":"10984130","doi":"10.1007/s005990070031","url":"https://pubmed.ncbi.nlm.nih.gov/10984130/"},{"id":2703,"title":"Oxidation of 7,8-dihydroneopterin by hypochlorous acid yields neopterin.","authors":"Widner, B; Mayr, C; Wirleitner, B; Fuchs, D","year":2000,"date":"2000 Aug 28","journal":"Biochemical and biophysical research communications","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"In vitro, interferon-gamma stimulates primate monocytes/macrophages to produce the pteridines neopterin and 7,8-dihydroneopterin. These pteridines are capable of modulating the oxidative potential of reactive species. Neopterin is pro-oxidative whereas 7, 8-dihydroneopterin is an effective antioxidant. In the presence of oxygen, 7,8-dihydroneopterin is rapidly oxidized and after loosing the side chain 7,8-dihydroxanthopterin is formed. It is considered that under physiological conditions, 7,8-dihydroneopterin cannot be a source for neopterin production. In this study it is demonstrated that hypochlorous acid is capable to oxidize 7,8-dihydroneopterin yielding neopterin. Neopterin is less affected by hypochlorous acid, and in a mixture of both pteridines similar to the in vivo situation, only 7,8-dihydroneopterin is oxidized, thereby increasing the ratio towards neopterin. The findings may beat relevance for the in vivo situation since hypochlorous acid shifts the neopterin/7, 8-dihydroneopterin ratio towards the side of neopterin, hence probably increasing the oxidative potential in a micro-environment.","pmid":"10964663","doi":"10.1006/bbrc.2000.3323","url":"https://pubmed.ncbi.nlm.nih.gov/10964663/"},{"id":2705,"title":"Improved sensitivity proteomics by postharvest alkylation and radioactive labelling of proteins.","authors":"Vuong, G L; Weiss, S M; Kammer, W; Priemer, M; Vingron, M; Nordheim, A; Cahill, M A","year":2000,"date":"2000 Jul","journal":"Electrophoresis","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"We describe approaches to improve the detection of proteins by postharvest alkylation and subsequent radioactive labeling with either [3H]iodoacetamide or 125I. Database protein sequence analysis suggested that cysteine is not suitable for detection of the entire proteome, but that cysteine alkylating reagents can increase the number of proteins able to be detected by iodination chemistry. Proteins were alkylated with beta-(4-hydroxyphenyl)ethyl iodoacetamide, or with 1,5-l-AEDANS (the Hudson Weber reagent). Subsequent iodination using the Iodo-Gen system was found to be most efficient. The enhanced sensitivity obtainable by using these approaches is expected to be sufficient for visualization of the lowest copy number proteins from human cells, such as from clinical samples. However, we argue that significantly improved methods of protein separation will be necessary to resolve the large number of proteins expected to be detectable with this sensitivity.","pmid":"10949135","doi":"10.1002/1522-2683(20000701)21:13<2594::AID-ELPS2594>3.0.CO;2-K","url":"https://pubmed.ncbi.nlm.nih.gov/10949135/"},{"id":2706,"title":"Survival of Yersinia enterocolitica and mesophilic aerobic bacteria on eggshell after washing with hypochlorite and organic acid solutions.","authors":"Favier, G I; Escudero, M E; Mattar, M A; de Guzmán, A M","year":2000,"date":"2000 Aug","journal":"Journal of food protection","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Populations of Yersinia enterocolitica 0:9 and mesophilic aerobic bacteria on the shell of fresh chicken eggs were assessed prior and after washing with 0.75%, 1%, and 3% acetic and lactic acids, 50, 100, and 200 mg/liter (ppm) of chlorine, and water. Highest reductions of mesophilic aerobic bacterial populations (normal flora) on trypticase soy agar were 1.28 and 2.15 log10 cycles with 100 and 200 mg/liter of chlorine, 0.28 and 0.36 log10 cycles with 1% and 3% acetic acid, and 0.70 and 0.71 log10 cycles with 1% and 3% lactic acid, respectively, as compared to the control group. No Salmonella or Yersinia were detected among the natural flora of the eggs. On Y. enterocolitica O:9-inoculated eggs, reductions of 2.66, 2.77, and 2.92 log10 cycles by 50, 100, and 200 mg/liter of chlorine, of 2.47, 2.48, and 2.49 log10 cycles by 0.75%, 1%, and 3% of acetic acid, and of 2.48 and 2.72 log10 cycles with 1% and 3% of lactic acid, respectively, were observed with respect to the control. Organic acids at 3% caused detachment of the surface cuticle of the eggshell. Y. enterocolitica was more sensitive to the wash treatments than the natural microflora. The absence of potentially pathogenic Y. enterocolitica, observed for other fresh foods, should be a norm for fresh eggs sold in retail stores.","pmid":"10945580","doi":"10.4315/0362-028x-63.8.1053","url":"https://pubmed.ncbi.nlm.nih.gov/10945580/"},{"id":2708,"title":"Antimicrobial and cytotoxic activity of hypochlorous acid: interactions with taurine and nitrite.","authors":"Marcinkiewicz, J; Chain, B; Nowak, B; Grabowska, A; Bryniarski, K; Baran, J","year":2000,"date":"2000 Jun","journal":"Inflammation research : official journal of the European Histamine Research Society ... [et al.]","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVE: HOCl, a major bactericidal product of neutrophil MPO-halide system reacts with taurine to form taurine chloramine (TauCl), a less toxic anti-inflammatory mediator. Recently, it has been reported that HOCl may also react with nitrite (NO2-), a major end-product of nitric oxide (NO) metabolism, to form very active oxidant, nitryl chloride (NO2Cl). The present study was conducted to elucidate the effect of nitrite on bactericidal and some immunoregulatory properties of HOCl and TauCl. MATERIALS: TauCl was prepared from NaOCl and taurine. The reaction was carried out at pH 5.0 and pH 7.4, in the presence or absence of nitrite. All reactions were monitored by UV absorption spectra. METHODS: Bactericidal activity of HOCl and TauCl in the presence of nitrite was tested by incubation of E. coli with the compounds and determined by the pour-plate method. To test the effect of the compounds on activity of inflammatory cells, murine peritoneal neutrophils (PMN) and macrophages were used. The cells were activated in vitro with either LPS, IFN-gamma or zymosan and the production of following mediators was measured: reactive oxygen species using luminol-dependent chemiluminescence; nitric oxide by Griess reaction; TNF-alpha using capture ELISA. In addition, we tested the effect of HOCl and TauCl on activity of myeloperoxidase (MPO). RESULTS: At physiological pH nitrite reacts with HOCl but not with TauCl. This reaction was abolished in the presence of taurine. Nitrite prevented HOCl-mediated bacterial killing, inhibition of MPO activity, cellular cytotoxicity and inhibition of TNF-alpha production. Nitrite did not affect any activity of TauCl. CONCLUSION: We have shown that nitrite may react in vitro with HOCl but not with TauCl, to form new biologically active product(s). We did not confirm the hypothesis that a product of HOCl reaction with nitrite is more toxic than HOCl. To the contrary, we found that nitrite diminished bactericidal and immunoregulatory properties of HOCl. In vivo, nitrite will also compete with taurine for reaction with PMN-released HOCl. Nevertheless, due to high concentration of taurine in PMN cytosol, formation of TauCl will be a major regulatory mechanism of MPO-halide-system.","pmid":"10939618","doi":"10.1007/PL00000208","url":"https://pubmed.ncbi.nlm.nih.gov/10939618/"},{"id":2715,"title":"Efficacy of novel organic acid and hypochlorite treatments for eliminating Escherichia coli O157:H7 from alfalfa seeds prior to sprouting.","authors":"Lang, M M; Ingham, B H; Ingham, S C","year":2000,"date":"2000 Jun 30","journal":"International journal of food microbiology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"This study investigated novel two-step organic acid/hypochlorite treatments as alternatives to 20000 ppm active chlorine (from calcium hypochlorite) for eliminating Escherichia coli O157:H7 from alfalfa seeds prior to sprouting. Commercially available alfalfa seeds were inoculated with a five-strain E. coli O157:H7 mixture and dried to attain ca. 10(6) CFU/g of seeds. Seeds then underwent one of several soak treatments including: (1) 5% (v/v) lactic acid for 10 min at 42 degrees C; (2) 5% acetic acid (v/v) for 10 min at 42 degrees C; (3) 2.5% lactic acid for 10 min at 42 degrees C followed by 2000 ppm active chlorine (from calcium hypochlorite) for 15 min at 25 degrees C; (4) 5% lactic acid for 10 min at 42 degrees C followed by 2000 ppm active chlorine for 15 min at 25 degrees C; or (5) 20000 ppm active chlorine for 15 min at 25 degrees C. Each treatment reduced numbers of inoculum cells by about 6.0 log10 CFU/g as determined by plating on Sorbitol MacConkey agar (SMac). Plating on non-selective brain heart infusion agar (BHI) showed that treatments 1-4 reduced counts by 2.3-4.1 log10 CFU/g, thus indicating a large proportion of injured cells. Successive lactic acid and hypochlorite treatments (3 and 4) were more lethal than either organic acid alone (1 and 2). No surviving cells were detected on SMac or BHI following treatment with 20000 ppm active chlorine (treatment 5). Regardless of the previous treatment, E. coli O157:H7 counts increased to 10(7)-10(8) CFU/g during sprouting. Germination of seeds was not adversely affected by any of the treatments (germination > 90%). Results of this study show that: (a) non-lethal cell injury must be considered when evaluating intervention treatments against E. coli O157:H7 on alfalfa seeds; (b) reductions of 2-4 log10 CFU/g can be attained without using 20000 ppm active chlorine; (c) successive lactic acid and hypochlorite treatments have greater lethality than organic acid treatments alone; and (d) none of the treatments tested can prevent regrowth of surviving E. coli O157:H7 during sprouting.","pmid":"10898464","doi":"10.1016/s0168-1605(00)00297-x","url":"https://pubmed.ncbi.nlm.nih.gov/10898464/"},{"id":2719,"title":"Nitrite-induced deamination and hypochlorite-induced oxidation of DNA in intact human respiratory tract epithelial cells.","authors":"Spencer, J P; Whiteman, M; Jenner, A; Halliwell, B","year":2000,"date":"2000 Apr 1","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"No modification of purine or pyrimidine bases was observed when isolated DNA was incubated with 1 mM nitrite at pH 7.4. However, exposure of human bronchial epithelial cells in culture medium at pH 7.4 to nitrite at concentrations of 100 microM or greater led to deamination of purine bases in cellular DNA. Deamination was more extensive in cells exposed to lower extracellular pH values and higher nitrite concentrations. Significant increases in the levels of xanthine and hypoxanthine, putative deamination products of guanine and adenine, respectively, were observed in DNA from nitrite-treated cells but no rise in any base oxidation products such as 8-hydroxyguanine. This pattern of damage suggests that exposure of cells to nitrite (even at pH 7.4) leads to intracellular generation of \"reactive nitrogen species\" capable of deaminating purines in DNA. In addition, significant DNA strand breakage occurred in nitrite-treated cells. The time course of base damage suggested that the repair of deaminated purine lesions in these cells is slow. By contrast, DNA isolated from cells exposed to hypochlorous acid (HOCl) has significant oxidation of pyrimidine bases and chlorination of cytosine but little oxidation of purines. Exposure of cells to both species (NO(2)(-) plus HOCl) potentiated the oxidative DNA base damage observed but decreased the extent of deamination. We hypothesize that this is due to the formation of nitryl chloride (NO(2)Cl) from reaction of HOCl with *NO(2)(-). The relevance of our observations to events in the stomach and respiratory tract, at sites of inflammation, and in ischemic tissues is discussed.","pmid":"10832065","doi":"10.1016/s0891-5849(00)00190-8","url":"https://pubmed.ncbi.nlm.nih.gov/10832065/"},{"id":2726,"title":"Comparison of mono- and dichlorinated tyrosines with carbonyls for detection of hypochlorous acid modified proteins.","authors":"Chapman, A L; Senthilmohan, R; Winterbourn, C C; Kettle, A J","year":2000,"date":"2000 May 1","journal":"Archives of biochemistry and biophysics","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Hypochlorous acid is a potent oxidant capable of oxidizing and chlorinating proteins. Based on its indiscriminant reactivity, it is proposed to play a major role in tissue damage associated with a range of inflammatory diseases. We have determined the relative tendencies for formation of protein carbonyls, chlorinated tyrosine residues, and epitopes recognized by an antibody raised against hypochlorous acid oxidized protein (HOP-1) when albumin is treated with hypochlorous acid. We have also tested the specificity of the HOP-1 antibody by measuring how effectively it recognizes proteins oxidized by hypobromous acid. 3-Chlorotyrosine, along with a new marker of hypochlorous acid dependent protein modification, 3, 5-dichlorotyrosine, was formed at the lowest doses of hypochlorous acid that were capable of generating protein carbonyls. Comparatively high doses of hypochlorous acid were needed to generate epitopes recognized by HOP-1, which were also produced by hypobromous acid. Our study demonstrates that it is advantageous to measure protein carbonyls and HOP-1 epitopes in conjunction with chlorinated tyrosines when attempting to identify the oxidants responsible for inflammatory tissue damage.","pmid":"10775446","doi":"10.1006/abbi.2000.1744","url":"https://pubmed.ncbi.nlm.nih.gov/10775446/"},{"id":2729,"title":"Nitrite as a substrate and inhibitor of myeloperoxidase. Implications for nitration and hypochlorous acid production at sites of inflammation.","authors":"van Dalen, C J; Winterbourn, C C; Senthilmohan, R; Kettle, A J","year":2000,"date":"2000 Apr 21","journal":"The Journal of biological chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase is a heme enzyme of neutrophils that uses hydrogen peroxide to oxidize chloride to hypochlorous acid. Recently, it has been shown to catalyze nitration of tyrosine. In this study we have investigated the mechanism by which it oxidizes nitrite and promotes nitration of tyrosyl residues. Nitrite was found to be a poor substrate for myeloperoxidase but an excellent inhibitor of its chlorination activity. Nitrite slowed chlorination by univalently reducing the enzyme to an inactive form and as a consequence was oxidized to nitrogen dioxide. In the presence of physiological concentrations of nitrite and chloride, myeloperoxidase catalyzed little nitration of tyrosyl residues in a heptapeptide. However, the efficiency of nitration was enhanced at least 4-fold by free tyrosine. Our data are consistent with a mechanism in which myeloperoxidase oxidizes free tyrosine to tyrosyl radicals that exchange with tyrosyl residues in peptides. These peptide radicals then couple with nitrogen dioxide to form 3-nitrotyrosyl residues. With neutrophils, myeloperoxidase-dependent nitration required a high concentration of nitrite (1 mM), was doubled by tyrosine, and increased 4-fold by superoxide dismutase. Superoxide is likely to inhibit nitration by reacting with nitrogen dioxide and/or tyrosyl radicals. We propose that at sites of inflammation myeloperoxidase will nitrate proteins, even though nitrite is a poor substrate, because the co-substrate tyrosine will be available to facilitate the reaction. Also, production of 3-nitrotyrosine will be most favorable when the concentration of superoxide is low.","pmid":"10766781","doi":"10.1074/jbc.275.16.11638","url":"https://pubmed.ncbi.nlm.nih.gov/10766781/"},{"id":2731,"title":"Hypochlorous acid-induced responses in sheep isolated pulmonary artery rings.","authors":"Turan, N N; Demiryürek, A T; Kanzik, I","year":2000,"date":"2000 May","journal":"Pharmacological research","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The formation of reactive oxygen species (ROS) appears to play a significant role in many pathological states including cystic fibrosis and asthma. Although stimulated inflammatory cells represent a major source of oxygen metabolites and these cells are able to generate the potent oxidant hypochlorous acid (HOCl) effects of HOCl on arteries are not known. HOCl at low concentrations (10(-7)to 10(-4)m) did not affect the resting force or have an action in precontracted sheep pulmonary arteries. HOCl at 10(-4) m concentration reduced histamine-induced relaxations in endothelium intact preparations. However, at high concentrations (10(-2) to 1 m) HOCl led to constriction under resting conditions and caused vasodilation in endothelium intact and denuded serotonin (10 microm) precontracted arteries. These effects of HOCl were significantly reduced by pretreatment of l -arginine (10(-3)m), sodium nitroprusside (SNP, 10(-5) m) and N -acetyl-l-cysteine (NAC, 10(-4) m). The effects of SNP and NAC on HOCl-induced responses were due to direct interaction since only these compounds markedly diminished the HOCl-induced luminol chemiluminescence (CL). Lack of contraction with KCl after high concentrations of HOCl showed that HOCl causes irreversible tissue damage. These results suggest that HOCl produce vasoconstriction under resting force and cause vasodilation when the pulmonary arteries precontracted. HOCl may interact with endothelium-derived mediators and contribute to tissue injury and vascular dysfunction seen in disease states.","pmid":"10753560","doi":"10.1006/phrs.1999.0628","url":"https://pubmed.ncbi.nlm.nih.gov/10753560/"},{"id":2733,"title":"Vitamin C protects against and reverses specific hypochlorous acid- and chloramine-dependent modifications of low-density lipoprotein.","authors":"Carr, A C; Tijerina, T; Frei, B","year":2000,"date":"2000 Mar 1","journal":"The Biochemical journal","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Activated phagocytes produce the highly reactive oxidant hypochlorous acid (HOCl) via the myeloperoxidase-catalysed reaction of hydrogen peroxide with chloride ions. HOCl reacts readily with a number of susceptible targets on apolipoprotein B-100 of low-density lipoprotein (LDL), resulting in uncontrolled uptake of HOCl-modified LDL by macrophages. We have investigated the effects of vitamin C (ascorbate), an effective water-soluble antioxidant, on the HOCl- and chloramine-dependent modification of LDL. Co-incubation of vitamin C (25-200 microM) with LDL resulted in concentration-dependent protection against HOCl (25-200 microM)-mediated oxidation of tryptophan and lysine residues, formation of chloramines and increases in the relative electrophoretic mobility of LDL. Vitamin C also partially protected against oxidation of cysteine residues by HOCl, and fully protected against oxidation of these residues by the low-molecular-mass chloramines, N(alpha)-acetyl-lysine chloramine and taurine chloramine, and to a lesser extent monochloramine (each at 25-200 microM). Further, we found that HOCl (25-200 microM)-dependent formation of chloramines on apolipoprotein B-100 was fully reversed by 200 microM vitamin C; however, the loss of lysine residues and increase in relative electrophoretic mobility of LDL were only partially reversed, and the loss of tryptophan and cysteine residues was not reversed. Time-course experiments showed that the reversal by vitamin C of HOCl-dependent modifications became less efficient as the LDL was incubated for up to 4 h at 37 degrees C. These data show that vitamin C not only protects against, but also reverses, specific HOCl- and chloramine-dependent modifications of LDL. As HOCl-mediated LDL modifications have been strongly implicated in the pathogenesis of atherosclerosis, our data indicate that vitamin C could contribute to the anti-atherogenic defence against HOCl.","pmid":"10677371","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/10677371/"},{"id":2737,"title":"The effectiveness of hygiene procedures for prevention of cross-contamination from chicken carcases in the domestic kitchen.","authors":"Cogan, T A; Bloomfield, S F; Humphrey, T J","year":1999,"date":"1999 Nov","journal":"Letters in applied microbiology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Thirteen sites in each of 60 domestic kitchens were examined for Salmonella and Campylobacter spp. following the preparation of a chicken for cooking and the application of different hygiene regimes. During food preparation bacteria became widely disseminated to hand and food contact surfaces. Where cleaning was carried out with detergent and hot water using a prescribed routine there was no significant decrease in the frequency of contaminated surfaces. Where hypochlorite was used in addition, a significant reduction in the number of contaminated sites was observed. The study suggests that there is a need to better understand and promote effective hygiene procedures for the domestic kitchen.","pmid":"10664978","doi":"10.1046/j.1472-765x.1999.00656.x","url":"https://pubmed.ncbi.nlm.nih.gov/10664978/"},{"id":2742,"title":"The reported clinical utility of taurine in ischemic disorders may reflect a down-regulation of neutrophil activation and adhesion.","authors":"McCarty, M F","year":1999,"date":"1999 Oct","journal":"Medical hypotheses","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"The first publications regarding clinical use of taurine were Italian reports claiming therapeutic efficacy in angina, intermittent claudication and symptomatic cerebral arteriosclerosis. A down-regulation of neutrophil activation and endothelial adhesion might plausibly account for these observations. Endothelial platelet-activating factor (PAF) is a crucial stimulus to neutrophil adhesion and activation, whereas endothelial nitric oxide (NO) suppresses PAF production and acts in various other ways to antagonize binding and activation of neutrophils. Hypochlorous acid (HOCl), a neutrophil product which avidly oxidizes many sulfhydryl-dependent proteins, can be expected to inhibit NO synthase while up-regulating PAF generation; thus, a vicious circle can be postulated whereby HOCl released by marginating neutrophils acts on capillary or venular endothelium to promote further neutrophil adhesion and activation. Taurine is the natural detoxicant of HOCl, and thus has the potential to intervene in this vicious circle, promoting a less adhesive endothelium and restraining excessive neutrophil activation. Agents which inhibit the action of PAF on neutrophils, such as ginkgolides and pentoxifylline, have documented utility in ischemic disorders and presumably would complement the efficacy of taurine in this regard. Fish oil, which inhibits endothelial expression of various adhesion factors and probably PAF as well, and which suppresses neutrophil leukotriene production, may likewise be useful in ischemia. These agents may additionally constitute a non-toxic strategy for treating inflammatory disorders in which activated neutrophils play a prominent pathogenic role. Double-blind studies to confirm the efficacy of taurine in symptomatic chronic ischemia are needed.","pmid":"10608263","doi":"10.1054/mehy.1998.0760","url":"https://pubmed.ncbi.nlm.nih.gov/10608263/"},{"id":2743,"title":"Antioxidant properties of albumin: effect on oxidative metabolism of human neutrophil granulocytes.","authors":"Kouoh, F; Gressier, B; Luyckx, M; Brunet, C; Dine, T; Cazin, M; Cazin, J C","year":1999,"date":"1999 Oct 30","journal":"Farmaco (Societa chimica italiana : 1989)","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"The present study aims at investigating the effect of bovine serum albumin (BSA) on the trial of oxidative-stress. The antioxidant effects of BSA were determined by human neutrophil granulocytes oxygen free radicals and their by-products (O2-, H2O2, HOCl) productions. BSA interacts with those reactive oxygen species (ROS) in a dose-dependent manner. The 50% inhibitory concentration (IC50) of BSA estimated, after phorbol-12-myristate-13-acetate (PMA) stimulation were: 33.5 mg/ml for O2-, 6.5 mg/ml for H2O2, and 6.85 mg/ml for HOCl. When neutrophils were washed after pre-incubation with BSA, there was no significant decrease of ROS after stimulation of PMA (maximal: 15 +/- 1.2%). In the free cell experiments, IC50 for H2O2 and HOCl were 7.86 mg/ml and 0.67 mg/ml, respectively. The mechanism at which BSA acts may result from a simple chemical interaction with ROS rather than an intracellular mechanism by intervention in PMA oxidative metabolism. These antioxidant activities confer to BSA properties, which might be used to prevent damage inflicted by these ROS during inflammatory disorders.","pmid":"10575739","doi":"10.1016/s0014-827x(99)00082-8","url":"https://pubmed.ncbi.nlm.nih.gov/10575739/"},{"id":2749,"title":"NADPH as a co-substrate for studies of the chlorinating activity of myeloperoxidase.","authors":"Auchère, F; Capeillère-Blandin, C","year":1999,"date":"1999 Nov 1","journal":"The Biochemical journal","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The reinvestigation of the kinetics of myeloperoxidase (MPO) activity with the use of NADPH as a probe has allowed us to determine the effects of H(2)O(2), Cl(-) ion and pH on the MPO-dependent production of HOCl. The chlorination rate of NADPH did not depend on NADPH concentration and was entirely related to the rate of production of HOCl by MPO. The overall oxidation of NADPH occurred similarly in the absence of O(2) and was insensitive to scavengers of the superoxide radical anion. Experiments performed on the direct oxidation of NADPH by MPO in the presence and the absence of H(2)O(2) showed that neither the rate nor the stoichiometry of the reaction could interfere in the NADPH oxidation process involved in the steady-state chlorination cycle. The oxidation of NADPH was characterized by a decrease in the A(339) of the reduced nicotinamide with the concomitant appearance of a new chromophore with absorbance maximum at 274 nm, characterized by isosbestic points at 300 and 238 nm. The reaction product did not possess any enzymic properties with dehydrogenases and led to a metabolite other than NADP(+). Its amount accounted for a stoichiometric conversion of H(2)O(2) into HOCl. Analyses of the NADPH reaction allowed the determination of both kinetic (k(cat) and K(m)) and thermodynamic (K(d)) parameters. When the values of kinetic parameters were compared with previously published ones, the main discrepancy was found with data obtained with the chlorination of monochlorodimedon and a better agreement with diethanolchloramine formation or H(2)O(2) consumption. Variations in the extent of NADPH oxidation with Cl(-) concentration enabled us to determine the dissociation constant for the enzyme-Cl(-) complex. In the course of titration studies, the spectral properties of NADPH reacting with either HOCl or the MPO/H(2)O(2)/Cl(-) system were quantitatively similar in terms of stoichiometry and absorbance coefficient and thus led to identical chlorinated products. However, no spectral modification occurred with NADP(+) and adenine nucleotide analogues under the same conditions. A quantitative comparison of difference spectra obtained with NADPH and NMNH indicated that chlorination occurred on the nicotinamide part of the molecule.","pmid":"10527939","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/10527939/"},{"id":2750,"title":"Consecutive halogen transfer between various functional groups induced by reaction of hypohalous acids: NADH oxidation by halogenated amide groups.","authors":"Prütz, W A","year":1999,"date":"1999 Nov 1","journal":"Archives of biochemistry and biophysics","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Cyclic dipeptides (c-Gly(2), c-Ser(2), c-Gly-Phe, etc.) were used as simple protein models to investigate the HOCl-induced generation and reactivity of chlorinated amide groups. The pH dependence of the kinetics of amide chlorination reveals that ClO(-) (not HOCl) is the reactive agent. N-Chlorinated cyclopeptides are stable up to 30 min, they exhibit narrow absorption bands around 215 nm, and they are capable of oxidizing certain biological substrates, the reactivity decreasing in the order GSH > ascorbate > methionine > NADH >> GSSG. The chloroamide is less reactive, but much more selective in its reactions, than HOCl or ClO(-); thus, with formation of the chloroamide prolonged oxidative effects, directed toward specific target molecules, can be expected. Chlorination of NADH, yielding a catalytically inactive species (NAD/Cl), was investigated in most detail because it is likely to be an important and highly lethal process. The chloroamide group is far more reactive toward NADH than chloroamines derived from primary amines. Chloronucleotides formed by reaction of ClO(-) with inosine, GMP, TMP, or UMP are capable of quantitative chlorine transfer to cyclopeptides; however, no chlorine transfer between the amide nitrogen and primary amines is detectable, in either direction. The results presented enable prediction of chlorine transfer cascades induced by HOCl/ClO(-), involving nucleotides, peptide amide groups, and final target molecules. Chlorinated NAD(P)H, as a stable terminal product of consecutive chlorine transfer reactions, might be a useful biological marker for assessing the role of HOCl in inflammatory events. Bromination by BrO(-) of cyclopeptides is more than two orders of magnitude faster than chlorination by ClO(-), and the reactivity of bromoamide with NADH exceeds that of chloroamide by more than four orders of magnitude.","pmid":"10525295","doi":"10.1006/abbi.1999.1377","url":"https://pubmed.ncbi.nlm.nih.gov/10525295/"},{"id":2754,"title":"Oxidative damage to proteins of bronchoalveolar lavage fluid in patients with acute respiratory distress syndrome: evidence for neutrophil-mediated hydroxylation, nitration, and chlorination.","authors":"Lamb, N J; Gutteridge, J M; Baker, C; Evans, T W; Quinlan, G J","year":1999,"date":"1999 Sep","journal":"Critical care medicine","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"OBJECTIVE: To assess the degree, source, and patterns of oxidative damage to bronchoalveolar lavage proteins as a modification of amino acid residues in patients with acute respiratory distress syndrome (ARDS). DESIGN: Prospective, controlled study. SETTING: Adult intensive care unit of a postgraduate teaching hospital. PATIENTS: Twenty-eight patients with established ARDS were studied and compared with six ventilated patients without ARDS and 11 normal healthy controls. INTERVENTIONS: Supportive techniques appropriate to ARDS. MEASUREMENTS AND MAIN RESULTS: Evidence of oxidative modification of bronchoalveolar lavage fluid protein, indicative of the production of specific reactive oxidizing species, was sought using a high-performance liquid chromatography technique. Bronchoalveolar lavage fluid samples from patients with ARDS, ventilated intensive care controls, and normal healthy controls were analyzed. Concentrations of orthotyrosine were significantly higher in the ARDS group than in either control group (7.98 + 3.78 nmol/mg for ARDS, 0.67 + 0.67 for ventilated controls, and 0.71 + 0.22 for healthy controls; p < .05). Chlorotyrosine concentrations were also significantly increased in the ARDS group over either control group (4.82 + 1.07 nmol/mg for ARDS, 1.55 + 1.34 for ventilated controls, and 0.33 + 0.12 for healthy controls; p < .05). Nitrotyrosine concentrations were similarly significantly increased in the ARDS groups compared with each control group (2.21 + 0.65 nmol/mg for ARDS, 0.29 + 0.29 for ventilated controls, and 0.06 + 0.03 for healthy controls; p < .05). Chlorotyrosine and nitrotyrosine concentrations showed significant correlations with myeloperoxidase concentrations in bronchoalveolar lavage fluid, measured using an enzyme-linked immunosorbent assay in patients with ARDS. These findings suggest a possible relationship between inflammatory cell activation, oxidant formation, and damage to proteins in the lungs of these patients CONCLUSIONS: Overall, our data strongly suggest heightened concentrations of oxidative stress in the lungs of patients with ARDS that lead to significantly increased oxidative protein damage.","pmid":"10507592","doi":"10.1097/00003246-199909000-00007","url":"https://pubmed.ncbi.nlm.nih.gov/10507592/"},{"id":2759,"title":"Short exposure of polymorphonuclear leucocytes to sodium fluoride suppresses the response to fMLP.","authors":"Knoll-Köhler, E; Büssem, G","year":1999,"date":"1999 Jul","journal":"Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS)","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Fluoridated dental care products are used to prevent dental decay. Up to now, there are no data available on whether the fluoride (F-) component of these products affects the bactericidal activity of salivary polymorpho-nuclear leucocytes, which are involved in the protection of the oral mucosa against infection. Therefore, after determining the concentration/time profile of F- in mixed saliva of healthy subjects after topical application of 0.5 g of a 1.25% F- containing gel, unstimulated and fMLP-stimulated polymorphonuclear leucocytes (PMNs) were shortly exposed to these F- concentrations and the generation of superoxide and hypochloric acid were measured, as well as the liberation of lysomal enzymes, and correlated with the cellular Ca2+ and cAMP-levels. The results show that F-, at concentrations as retained in saliva, did not activate the oxidative burst in unstimulated PMNs. In fMLP-activated PMNs, F-suppressed the receptor-mediated increase in the oxidative burst and the liberation of fl-glucuronidase by reduction of the availability of extracellular Ca2+ and, thus, the influx of Ca2+ necessary to couple completely the fMLP signal to effector pathways. These F- concentrations neither altered the liberation of Ca2+ from internal stores nor induced a rise in cAMP. The possible clinical consequences of these results for xerostomic patients with respect to the generation of HOSCN/OSCN/SCN in saliva an important non-immune factor for oral health, are dicussed.","pmid":"10445221","doi":"10.1016/S0946-672X(99)80026-1","url":"https://pubmed.ncbi.nlm.nih.gov/10445221/"},{"id":2760,"title":"Chlorination and nitration of soy isoflavones.","authors":"Boersma, B J; Patel, R P; Kirk, M; Jackson, P L; Muccio, D; Darley-Usmar, V M; Barnes, S","year":1999,"date":"1999 Aug 15","journal":"Archives of biochemistry and biophysics","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Diets enriched in soy foods containing a high concentration of isoflavonoids are associated with a decrease in the incidence of several chronic inflammatory diseases. Studies with experimental models of diseases, such as atherosclerosis, suggest that these effects can be ascribed to the biological properties of the isoflavones. Since the isoflavones and tyrosine have structural similarities and modifications to tyrosine by inflammatory oxidants such as hypochlorous acid (HOCl) and peroxynitrite (ONOO(-)) have been recently recognized, we hypothesized that the isoflavones also react with HOCl and ONOO(-). Using an in vitro approach, we demonstrate in the present study that the isoflavones genistein, daidzein, and biochanin-A can be chlorinated and nitrated by these oxidants. These reactions were investigated using high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance. In the reaction with HOCl, both mono- and dichlorinated derivatives of genistein and biochanin-A are formed, whereas with daidzein only a monochlorinated derivative was detected. The reaction between genistein or daidzein and ONOO(-) yielded a mononitrated product. However, no nitrated product was detected with biochanin-A. Furthermore, the reaction between genistein and sodium nitrite and HOCl yielded a chloronitrogenistein derivative, as well as a dichloronitrogenistein derivative. These results indicate that the ability of the isoflavones to react with these oxidant species depends on their structure and suggest that they could be formed under conditions where these reactive species are generated under pathological conditions.","pmid":"10441377","doi":"10.1006/abbi.1999.1330","url":"https://pubmed.ncbi.nlm.nih.gov/10441377/"},{"id":2765,"title":"Reactive oxygen species are partially involved in the bacteriocidal action of hypochlorous acid.","authors":"Dukan, S; Belkin, S; Touati, D","year":1999,"date":"1999 Jul 15","journal":"Archives of biochemistry and biophysics","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HOCl) is probably the most widely used disinfectant worldwide and has an important role in inflammatory reaction and in human resistance to infection. However, the nature and mechanisms of its bactericidal activity are still poorly understood. Bacteria challenged aerobically with HOCl concentrations ranging from 9.5 to 76 microM exhibit higher ability to form colonies anaerobically than aerobically. Conversely, aerobic plating greatly increased lethality after an anaerobic HOCl challenge, although anaerobic survival did not depend on whether HOCl exposure was aerobic or anaerobic. Even a short transient exposure to air after anaerobic HOCl challenge reduced anaerobic survival, indicative of immediate deleterious effects of oxygen. Exposure to HOCl can cause lethal DNA damage as judged by the fact that recA sensitivity to HOCl was oxygen dependent. Antioxidant defenses such as reduced glutathione and glucose-6-phosphate dehydrogenase were depleted or inactivated at 10 microM HOCl, while other activities, such as superoxide dismutase, dropped only above 57 microM HOCl. Cumulative deficiencies in superoxide dismutase and glucose-6-phosphate dehydrogenase rendered strains hypersensitive to HOCl. This indicates that part of HOCl toxicity on Escherichia coli is mediated by reactive oxygen species during recovery.","pmid":"10395749","doi":"10.1006/abbi.1999.1265","url":"https://pubmed.ncbi.nlm.nih.gov/10395749/"},{"id":2768,"title":"Effectiveness of various disinfectants in the elimination of Yersinia enterocolitica on fresh lettuce.","authors":"Escudero, M E; Velázquez, L; Di Genaro, M S; de Guzmán, A M","year":1999,"date":"1999 Jun","journal":"Journal of food protection","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The effectiveness of various disinfectants against two potentially pathogenic Yersinia enterocolitica strains (Y. enterocolitica W1024 O:9 [strain A] and Y. enterocolitica B O:5 Lis Xz [strain B]) on shredded lettuce was examined. Dip-wash treatments using 25, 100, and 300 ppm of chlorine at 4 and 22 degrees C, 0.2% Orenco Peel 40, 0.1% Tergitol, 0.5% acetic acid, and 0.5% lactic acid at 22 degrees C were performed. Surfactants and organic acids were also tested in combination with 100 ppm of chlorine. Reductions of Y. enterocolitica counts with 100 ppm (2.68 log10 for strain A and 2.36 log10 for strain B at 22 degrees C) and 300 ppm of chlorine (3.15 log10 for strain A and 2.55 log10 for strain B at 4 degrees C) were observed after 10 min. Inhibitory effect of different chlorine solutions was not significantly (P < 0.05) influenced by temperature. Surfactants in combination with chlorine were more effective than surfactants alone. Treatment with 0.2% Orenco Peel 40 plus 100 ppm of chlorine resulted in reductions of 2.69 log10 CFU/g for strain A and 3.18 1og10 CFU/g for strain B at 10 min. Dip solutions containing 0.1% Tergitol plus 100 ppm of chlorine produced a significant reduction of 2.73 log10 CFU/g in strain A (P < 0.05). With the 0.5% lactic acid plus 100 ppm of chlorine combination, inactivation of Y. enterocolitica was >6 log10. The bactericidal effect of disinfectants was related to the concentration, exposure time, combination with chlorine (surfactants and organic acids), and susceptibility of each strain. Since the presence of pathogenic Y. enterocolitica on ready-to-use vegetables represents a health hazard, treatments as effective as 0.5% lactic acid plus 100 ppm of chlorine are recommended for washing of fresh lettuce.","pmid":"10382658","doi":"10.4315/0362-028x-62.6.665","url":"https://pubmed.ncbi.nlm.nih.gov/10382658/"},{"id":2769,"title":"Analysis of 3-nitrotyrosine in biological fluids and protein hydrolyzates by high-performance liquid chromatography using a postseparation, on-line reduction column and electrochemical detection: results with various nitrating agents.","authors":"Ohshima, H; Celan, I; Chazotte, L; Pignatelli, B; Mower, H F","year":1999,"date":"1999","journal":"Nitric oxide : biology and chemistry","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Nitric oxide reacts rapidly with superoxide to form the strong nitrating agent peroxynitrite, which is responsible for much of the tissue damage associated with diverse pathophysiological conditions such as inflammation. The occurrence of free or protein-bound nitrotyrosine (NTYR) has been considered as evidence for in vivo formation of peroxynitrite. However, various agents can nitrate tyrosine, and their relative significance in vivo has not been determined due to lack of a sensitive method to analyze NTYR in tissue proteins and biological fluids. We have developed a new HPLC-electrochemical detection method to analyze NTYR in protein hydrolyzates or biological fluids. The sample is injected directly into a reversed-phase HPLC column and NTYR is subsequently reduced by a platinum column to 3-aminotyrosine, which is quantified with an electrochemical detector. The method is simple, selective, and sensitive (detection limit, 0.1 pmol per 20-microl injection). We have applied this method to compare in vitro the ability of various nitrating agents to form NTYR in bovine serum albumin and human plasma. Yields of NTYR formed in human plasma proteins incubated with 1 or 10 mM nitrating agent decreased in the following order: synthetic peroxynitrite > 3-morpholinosydonimine, a generator of both NO and superoxide > Angeli's salt, which forms nitroxyl anion (NO-) > spermine-NONOate, which releases NO > sodium nitrite plus hypochlorite, which forms the nitrating agent nitryl chloride (NO2Cl). A simple purification method using a C18 Sep-Pak cartridge is also described for analysis of free NTYR in human plasma.","pmid":"10369183","doi":"10.1006/niox.1999.0216","url":"https://pubmed.ncbi.nlm.nih.gov/10369183/"},{"id":2770,"title":"Disinfection of hospital waste sludge using hypochlorite and chlorine dioxide.","authors":"Tsai, C T; Lin, S T","year":1999,"date":"1999 May","journal":"Journal of applied microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Hypochlorite and chlorine dioxide were used to disinfect hospital waste-water sludge. Their abilities to inactivate pathogenic micro-organisms were compared. Reductions in indigenous coliform organisms and Pseudomonas aeruginosa were estimated. The results indicate that hypochlorite is a better disinfectant than chlorine dioxide for coliforms. Higher disinfection efficiency was obtained by treating a lower concentration of sludge. In addition, a higher agitation speed gave a higher disinfection efficiency with hypochlorite. The disinfection efficiencies of both disinfectants were higher against settled sludge than against thickened sludge. Therefore, it is recommended that disinfection should be performed on settled sludge rather than in a thickening tank.","pmid":"10347878","doi":"10.1046/j.1365-2672.1999.00732.x","url":"https://pubmed.ncbi.nlm.nih.gov/10347878/"},{"id":2775,"title":"[Puncture of liver cystic masses and abscesses].","authors":"Nishanov, K T; Durmanov, B D; Ishankhodzhaev, Kh R; Borovskiĭ, S P","year":1999,"date":"1999","journal":"Khirurgiia","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"The results of punctional treatment of cavital masses and abscesses of the liver in 58 patients are analysed. In 33 patients sanation was carried out according to traditional method, including local application of broad spectrum antibiotics; in 25 patients the solution of sodium-hypochlorite was used for treatment. Control group consisted of 38 patients, who underwent open surgical procedure. The application of the developed method of punctional treatment with the use of electrolyze solution of sodium hypochlorite provides the possibility to increase the terms of temperature normalization and cleansing and elimination of cavity 1.5 times comparing to traditional method of treatment, to decrease the number of complications and lethality, to reduce the duration of postoperation period 1.5-2 times comparing to the patients in whom traditional method of treatment was used, and 2-2.5 times comparing to the patients, who underwent operation.","pmid":"10216349","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/10216349/"},{"id":2777,"title":"Hypochlorous acid-induced DNA base modification: potentiation by nitrite: biomarkers of DNA damage by reactive oxygen species.","authors":"Whiteman, M; Spencer, J P; Jenner, A; Halliwell, B","year":1999,"date":"1999 Apr 13","journal":"Biochemical and biophysical research communications","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Chronic inflammation results in increased nitric oxide formation and nitrite (NO-2) accumulation. Activated phagocytes release myeloperoxidase generating the cytotoxic agent hypochlorous acid (HOCl). Reaction of HOCl with NO-2 results in the formation of nitryl chloride (NO2Cl), a potent oxidising, nitrating and chlorinating species. Exposure of DNA to NO-2 alone (up to 250 microM) at pH 7.4 did not induce oxidative DNA base damage. However, incubation of DNA with NO-2 in the presence of HOCl led to increases in thymine glycol, 5-hydroxyhydantoin, 8-hydroxyadenine and 5-chlorouracil to levels higher than those achieved by HOCl alone. No significant increases in 8-hydroxyguanine, xanthine, hypoxanthine, 2-hydroxyadenine, FAPy guanine, FAPy adenine and 8-chloroadenine were observed. HOCl-induced depletion of FAPy guanine and 8-hydroxyguanine was reduced in the presence of NO-2. Modification of DNA by HOCl/NO-2 (presumably generating NO2Cl) produces a pattern of DNA base damage products in isolated DNA that is similar to the pattern produced by HOCl but not other reactive species.","pmid":"10198253","doi":"10.1006/bbrc.1999.0448","url":"https://pubmed.ncbi.nlm.nih.gov/10198253/"},{"id":2778,"title":"Identification of the factors affecting the rate of deactivation of hypochlorous acid by melatonin.","authors":"Dellegar, S M; Murphy, S A; Bourne, A E; DiCesare, J C; Purser, G H","year":1999,"date":"1999 Apr 13","journal":"Biochemical and biophysical research communications","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"It has been found that melatonin reacts rapidly with hypochlorous acid in phosphate-buffered, ethanol-water solutions to produce 2-hydroxymelatonin. The rate law, d[2 - HOMel]/dt - kHOCl[Mel][HOCl] - kOCl-[Mel][OCl-], was obtained. At 37 degrees C and at a water concentration of 23.5 M, kOCl- = 6.0 x 10(2) L. mol-1. s-1, and kHOCl was found to be a function of the water concentration, kHOCl = 11 +/- 3 L3. mol-3. s-1. [H2O]2, indicating that the availability of water at the site of the reaction plays a significant role. The part that the structural components of melatonin play in determining the reaction pathway was examined by comparing the rate of deactivation of HOCl by melatonin to that of the model compounds indole, 5-methoxyindole, and 3-methylindole. The relative reactivity is explained in terms of steric and electronic effects, and it was found that the presence of the substituent at the 3-position influences the nature of the oxidation product. Melatonin and 3-methylindole yielded hydroxylated products, whereas indole and 5-methoxyindole produce chlorinated products.","pmid":"10198231","doi":"10.1006/bbrc.1999.0438","url":"https://pubmed.ncbi.nlm.nih.gov/10198231/"},{"id":2779,"title":"Inactivation of myocardial dihydrolipoamide dehydrogenase by myeloperoxidase systems: effect of halides, nitrite and thiol compounds.","authors":"Gutierrez-Correa, J; Stoppani, A O","year":1999,"date":"1999 Feb","journal":"Free radical research","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Dihydrolipoamide dehydrogenase (LADH) lipoamide reductase activity decreased whereas enzyme diaphorase activity increased after LADH treatment with myeloperoxidase (MPO) dependent systems (MPO/H2O2/halide, MPO/NADH/halide and MPO/H2O2/nitrite systems. LADH inactivation was a function of the composition of the inactivating system and the incubation time. Chloride, iodide, bromide, and the thiocyanate anions were effective complements of the MPO/H2O2 system. NaOCl inactivated LADH, thus supporting hypochlorous acid (HOCl) as putative agent of the MPO/H2O2/NaCl system. NaOCl and the MPO/H2O2/NaCl system oxidized LADH thiols and NaOCl also oxidized LADH methionine and tyrosine residues. LADH inactivation by the MPO/NADH/halide systems was prevented by catalase and enhanced by superoxide dismutase, in close agreement with H2O2 production by the LADH/NADH system. Similar effects were obtained with lactoperoxidase and horse-radish peroxidase supplemented systems. L-cysteine, N-acetylcysteine, penicillamine, N-(2-mercaptopropionylglycine), Captopril and taurine protected LADH against MPO systems and NaOCl. The effect of the MPO/H2O2/NaNO2 system was prevented by MPO inhibitors (sodium azide, isoniazid, salicylhydroxamic acid) and also by L-cysteine, L-methionine, L-tryptophan, L-tyrosine, L-histidine and reduced glutathione. The summarized observations support the hypothesis that peroxidase-generated \"reactive species\" oxidize essential thiol groups at LADH catalytic site.","pmid":"10193578","doi":"10.1080/10715769900300111","url":"https://pubmed.ncbi.nlm.nih.gov/10193578/"},{"id":2781,"title":"Modification of beta-adrenoceptors and adenylyl cyclase in hearts perfused with hypochlorous acid.","authors":"Persad, S; Dhalla, N S","year":1998,"date":"1998 Oct-Nov","journal":"Canadian journal of physiology and pharmacology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"It is now well known that the signal transduction pathway involving beta-adrenoceptors and adenylyl cyclase is altered in ischemic heart disease. Since leukocytes accumulate in the ischemic heart and produce hypochlorous acid (HOCl), we investigated the effects of HOCl upon beta-adrenoceptors and adenylyl cyclase activities by perfusing rat hearts with 0.1 mM HOCl for 10 min and isolating cardiac membranes. Marked depressions in both the density and affinity of beta1-adrenoceptors were observed, whereas no significant change in the affinity or density of beta2-adrenoceptors was seen in hearts perfused with HOCl. After treatment of hearts with HOCl, competition curves using isoproterenol, a beta-adrenoceptor agonist, revealed a decrease in the proportion of high affinity binding sites. The adenylyl cyclase activities in the absence and presence of forskolin, NaF, Gpp(NH)p, or isoproterenol were depressed in hearts perfused with HOCl; however, the stimulatory effects of these agents on adenylyl cyclase were either unaltered or augmented. The presence of methionine in the perfusion medium prevented the HOCl-induced changes in beta1-adrenoceptors and adenylyl cyclase activity. These results suggest that HOCl may produce a defect in the beta-adrenoceptor linked signal transduction mechanism by affecting both beta1-adrenoceptors and adenylyl cyclase enzyme in the myocardium.","pmid":"10100877","doi":"10.1139/cjpp-76-10-11-961","url":"https://pubmed.ncbi.nlm.nih.gov/10100877/"},{"id":2783,"title":"Severe impairment in early host defense against Candida albicans in mice deficient in myeloperoxidase.","authors":"Aratani, Y; Koyama, H; Nyui, S; Suzuki, K; Kura, F; Maeda, N","year":1999,"date":"1999 Apr","journal":"Infection and immunity","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase (MPO) catalyzes the reaction of hydrogen peroxide with chloride ion to produce hypochlorous acid (HOCl), which is used for microbial killing by phagocytic cells. Despite the important role of MPO in host defense, however, MPO deficiency is relatively common in humans, and most of these individuals are in good health. To define the in vivo role of MPO, we have generated by gene targeting mice having no MPO activity in their neutrophils and monocytes. The mice without MPO developed normally, were fertile, and showed normal clearance of intraperitoneal Staphylococcus aureus. However, they showed increased susceptibility to pneumonia and death following intratracheal infection with Candida albicans. Furthermore, the lack of MPO significantly enhanced the dissemination of intraperitoneally injected C. albicans into various organs during the first 7 days. Thus, MPO is important for early host defense against fungal infection, and the inability to generate HOCl cannot be compensated for by other oxygen-dependent systems in vivo in mice. The mutant mice serve as a model for studying pulmonary and systemic candidiasis.","pmid":"10085024","doi":"10.1128/IAI.67.4.1828-1836.1999","url":"https://pubmed.ncbi.nlm.nih.gov/10085024/"},{"id":2784,"title":"Oxidative resistance of Na/K-ATPase.","authors":"Kurella, E G; Tyulina, O V; Boldyrev, A A","year":1999,"date":"1999 Feb","journal":"Cellular and molecular neurobiology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"1. Oxidative modification of Na/K-ATPase from brain and kidney has been studied. Brain enzyme has been found to be more sensitive than kidney enzyme to inhibition by both H2O2 and NaOCl. 2. The inhibition of Na/K-ATPase correlates well with the decrease in a number of SH groups, suggesting that the latter belong mainly to ATPase protein and are essential for the enzyme activity. We suggest that the differences in the number, location, and accessibility of SH groups in Na/K-ATPase isozymes predict their oxidative stability. 3. The hydrophilic natural antioxidant carnosine, the hydrophobic natural antioxidant alpha-tocopherol, and the synthetic antioxidant ionol as well as the ferrous ion chelating agent deferoxamine were found to protect Na/K-ATPase from oxidation by different concentrations of H2O2. The data suggest that these antioxidants are effective due to their ability to neutralize or to prevent formation of hydroxyl radicals.","pmid":"10079972","doi":"10.1023/a:1006976810642","url":"https://pubmed.ncbi.nlm.nih.gov/10079972/"},{"id":2785,"title":"Alterations in cardiac membrane beta-adrenoceptors and adenylyl cyclase due to hypochlorous acid.","authors":"Persad, S; Elimban, V; Siddiqui, F; Dhalla, N S","year":1999,"date":"1999 Jan","journal":"Journal of molecular and cellular cardiology","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Although neutrophils and eosinophils are known to produce hypochlorous acid (HOCI) at the site of cardiac injury, the exact role of this toxic oxidant on the signal transduction mechanism in the heart is not clear. In this study, the effects of HOCI on beta-adrenoceptors, G-proteins and adenylyl cyclase activity were assessed by incubating rat heart membranes with HOCl. The basal as well as forskolin-, NaF-, 5-guanylylimidodiphosphate-, and isoproterenol-stimulated adenylyl cyclase activities were depressed by incubating cardiac membranes with HOCl. While both the density and affinity of the beta1-adrenoceptors were decreased by treatment of cardiac membranes with HOCl, the characteristics of the beta2-adrenoceptors were not modified significantly. Although cholera toxin-stimulated adenylyl cyclase activity, cholera toxin-catalyzed ADP-ribosylation and stimulatory guanine nucleotide binding protein immunoreactivity were depressed by HOCl, the pertussis toxin-stimulated adenylyl cyclase activity, pertussis toxin-catalyzed ADP ribosylation and inhibitory guanine nucleotide binding protein immunoreactivity were unaltered by HOCl. The presence of L-methionine in the incubation medium prevented the HOCl-induced alterations in adenylyl cyclase activities and characteristics of beta1-adrenoceptors. These results suggest that HOCl may be one of the factors attenuating the beta-adrenoceptor linked signal transduction mechanism in conditions such as ischemic heart disease.","pmid":"10072719","doi":"10.1006/jmcc.1998.0847","url":"https://pubmed.ncbi.nlm.nih.gov/10072719/"},{"id":2786,"title":"The effect of bioburden on in-depth disinfection of denture base acrylic resin.","authors":"Saunders, T R; Guillory, V L; Gregoire, S T; Pimsler, M; Mitchell, M S","year":1998,"date":"1998 Nov","journal":"Journal of the California Dental Association","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"This study evaluated the effectiveness of three different disinfectant solutions against denture bioburden absorbed within the depth of acrylic resin. Specimens were taken from dentures that had been worn by the patients for 15 to 20 years and were scheduled for replacement.","pmid":"10029780","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/10029780/"},{"id":2787,"title":"Comparative oxidation of loxapine and clozapine by human neutrophils.","authors":"Jegouzo, A; Gressier, B; Frimat, B; Brunet, C; Dine, T; Luyckx, M; Kouach, M; Cazin, M; Cazin, J C","year":1999,"date":"1999","journal":"Fundamental & clinical pharmacology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The clozapine-induced agranulocytosis could be due to the formation of a reactive intermediate formed in polymorphonuclear neutrophils and granulocyte precursors with the myeloperoxidase-hydrogen peroxide system. On the contrary, no case of agranulocytosis has been described for loxapine, an other neuroleptic drug with a very close structural analogy. We have compared the clozapine and loxapine interaction with the oxidative burst and particularly with this enzymatic complex. On the one hand, the assay of the oxidative species demonstrated a different impact for the two neuroleptics. The 50% inhibitory concentration was 92 microM for hydrogen peroxide and 40 microM for hypochlorous acid for loxapine. The loxapine target is located before the myeloperoxidase-hydrogen peroxide system in the oxidative stream, whereas clozapine diverts the chlorination pathway of the enzyme. On the other hand, the in vitro metabolism of drugs by the myeloperoxidase-hydrogen peroxide system has been investigated by mass spectrometry. Loxapine remains inert but clozapine undergoes the oxidation. The glutathione or ascorbate addition in the medium leads to a removal of the oxidation. Glutathione is able to trap the toxic intermediate and could avoid its formation.","pmid":"10027097","doi":"10.1111/j.1472-8206.1999.tb00329.x","url":"https://pubmed.ncbi.nlm.nih.gov/10027097/"},{"id":2789,"title":"Bactericidal effect of electrolyzed neutral water on bacteria isolated from infected root canals.","authors":"Horiba, N; Hiratsuka, K; Onoe, T; Yoshida, T; Suzuki, K; Matsumoto, T; Nakamura, H","year":1999,"date":"1999 Jan","journal":"Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"OBJECTIVE: The purposes of this study were to examine the time-related changes in pH, oxidation-reduction potential, and concentration of chlorine of electrolyzed neutral water and to evaluate the bactericidal effect of electrolyzed neutral water against bacteria from infected root canals. STUDY DESIGN: Various properties of electrolyzed neutral water--pH value, oxidation-reduction potential, and concentration of chlorine--were measured at different times after storage of the water in the open state, the closed state, or the closed-and-dark state. The bactericidal effect of the various electrolyzed neutral water samples was then tested against 17 strains of bacteria, including 15 strains isolated from infected canals, as well as against 1 strain of fungus. Each bacterial or fungal suspension was mixed with electrolyzed neutral water, and the 2 substances were reacted together for 1 minute. After incubation for 1 to 7 days, the bactericidal effect of the electrolyzed neutral water was determined. RESULTS: The pH value and oxidation-reduction potential of electrolyzed neutral water remained almost unchanged when the water was stored in a dark, closed container. However, the concentration of chlorine decreased from 18.4 ppm to 10.6 ppm. Electrolyzed neutral water showed a bactericidal or growth-inhibitory effect against the bacteria. CONCLUSIONS: The results indicate that electrolyzed neutral water maintains a constant pH and oxidation-reduction potential when kept in a closed container without light and that it exhibits a bacteriostatic/bactericidal action against isolates obtained from infected root canals.","pmid":"9927086","doi":"10.1016/s1079-2104(99)70300-8","url":"https://pubmed.ncbi.nlm.nih.gov/9927086/"},{"id":2791,"title":"Which conditions promote a remanent (persistent) bactericidal activity of chlorine covers?","authors":"Gottardi, W; Nagl, M","year":1998,"date":"1998 Dec","journal":"Zentralblatt fur Hygiene und Umweltmedizin = International journal of hygiene and environmental medicine","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The interaction of disinfectants containing active chlorine compounds (hypochlorite, chloramine T) with skin surfaces produces a so called chlorine cover which is a true chemical transformation of the protein matrix of the outermost horny skin layer by forming covalent N-Cl bonds. Though its intensity can easily be measured, the results on its remanent (persistent) bactericidal action until now have not been described consistently. While Gottardi and Karl observed a well-defined remanent action which correlated with the cover strength in the artificially with E. coli contaminated arm, Koller, Rotter, and Gottardi were not able to prove it, neither in artificially contaminated hands nor in the case of the resident bacterial colonization. To clarify these not consistent results, the bactericidal activity of chlorine covers on transient (dry contamination of the finger tips with Micrococcus luteus) as well as on resident colonization (after wearing gloves for 3 h) has been re-investigated using contact plates for recovering the bacteria. The results are showing that the remanent bactericidal action of chlorine covers strongly depends on the skin milieu, with moist conditions caused by sweat (surgical gloves) favoring the bactericidal activity. Elution experiments prove that protein constituents (detected by UV-spectrometry) continuously are transported to the skin-surface. It is obvious that the latter equilibrate with the chlorine cover by forming bactericidal N-Cl compounds with the effect that oxidation capacity fixed at the protein matrix is mobilized enabling the remanent bactericidal action.","pmid":"9916287","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/9916287/"},{"id":2793,"title":"Effect of cephapirin and mecillinam on the phagocytic and respiratory burst activity of neutrophil leukocytes isolated from bovine blood.","authors":"Dosogne, H; Hoeben, D; Burvenich, C; Lohuis, J A","year":1998,"date":"1998 Dec","journal":"Journal of veterinary pharmacology and therapeutics","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Antimicrobial therapy is the most commonly used treatment of bacterial infections in dairy cows. Polymorphonuclear neutrophil leukocytes (PMN) play an important role in the first line defence against invading bacteria and it is important that the function of PMN is not compromised by antibiotics. We investigated the in vitro effect of cephapirin, a first generation cephalosporin, and mecillinam, an amidinopenicillin with activity against mainly Gram-negative bacteria, on phagocytosis and respiratory burst activity of PMN isolated from bovine blood. After in vitro incubation of PMN with different concentrations of the antibiotics, phagocytosis was evaluated by flow cytometry and respiratory burst activity was evaluated by registration of chemiluminescence (CL) with a luminometer. None of the investigated concentrations of cephapirin and mecillinam had an effect in vitro on phagocytosis of Escherichia coli by PMN. At high concentrations (100 and 1000 microg/mL), cephapirin and mecillinam reduced the respiratory burst activity of PMN. Part of these suppressive effects could be ascribed to oxidant scavenging. Inhibitory effects of cephapirin were stronger than mecillinam. In conclusion, cephapirin and mecillinam did not seem to affect antibacterial activity of PMN isolated from bovine blood in vitro at therapeutic concentrations.","pmid":"9885963","doi":"10.1046/j.1365-2885.1998.00159.x","url":"https://pubmed.ncbi.nlm.nih.gov/9885963/"},{"id":2794,"title":"Isolation of Salmonella resistant to hypochlorous acid from a poultry abattoir.","authors":"Mokgatla, R M; Brözel, V S; Gouws, P A","year":1998,"date":"1998 Dec","journal":"Letters in applied microbiology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Salmonella is a Gram-negative bacterium that has been implicated in several food-borne poisoning outbreaks. Poultry products are considered to be the major vehicles of food-borne poisoning caused by Salmonella. The resistance of Salmonella, isolated from different stages in a local poultry abattoir, to hypochlorous acid (HOCl) was studied. Isolates cultured in quarter strength Tryptone Soya Broth were treated with 72 ppm HOCl, incubated at 30 degrees C with shaking, and absorbance was measured at 660 nm every 20 min. A number of resistant isolates, which carried on growing following HOCl addition, were obtained. All the isolates from the bleeding stage were sensitive to HOCl, whereas those from the scalding stage were resistant to HOCl. Other stages had a population of resistant and sensitive isolates. It is evident that some Salmonella will grow in the presence of concentrations of HOCl deemed to be inhibitory. Hence, an effective concentration of HOCl must be applied in poultry abattoirs to ensure that all the Salmonella are eradicated.","pmid":"9871358","doi":"10.1046/j.1472-765x.1998.00432.x","url":"https://pubmed.ncbi.nlm.nih.gov/9871358/"},{"id":2798,"title":"Hypochlorous acid activates the tumor suppressor protein p53 in cultured human skin fibroblasts.","authors":"Vile, G F; Rothwell, L A; Kettle, A J","year":1998,"date":"1998 Nov 1","journal":"Archives of biochemistry and biophysics","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The carcinogenicity associated with chronic inflammation has been attributed to neutrophils and the oxidants they produce. Neutrophils accumulate at sites of chronic inflammation, where they are stimulated to produce hydrogen peroxide which is converted to hypochlorous acid by coreleased myeloperoxidase. We report here that levels of the tumor suppressor protein p53 were increased in cultured human skin fibroblasts that had been incubated with stimulated neutrophils. The increase in p53 required the myeloperoxidase-dependent generation of hypochlorous acid and could be mimicked by exposing cells to a flux of hypochlorous acid produced by purified myeloperoxidase and a hydrogen peroxide-generating system. Levels of p53 were very sensitive to hypochlorous acid, with fluxes as low as 0.2 microM per min being effective. Levels of the p53-dependent protein WAF1/CIP1 were also elevated when fibroblasts were treated with hypochlorous acid. This result indicates that the p53 in the cells treated with hypochlorous acid was transcriptionally active. Hydrogen peroxide alone also elevated p53 and WAF1/CIP1, but the fluxes required were nearly 10-fold higher than those that were effective for hypochlorous acid. Our results implicate hypochlorous acid in the neutrophil-dependent initiation of a signal transduction pathway which could minimize the carcinogenicity of chronic inflammation.","pmid":"9799559","doi":"10.1006/abbi.1998.0881","url":"https://pubmed.ncbi.nlm.nih.gov/9799559/"},{"id":2800,"title":"Inside the neutrophil phagosome: oxidants, myeloperoxidase, and bacterial killing.","authors":"Hampton, M B; Kettle, A J; Winterbourn, C C","year":1998,"date":"1998 Nov 1","journal":"Blood","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"","pmid":"9787133","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/9787133/"},{"id":2804,"title":"Reactions of hypochlorous acid with biological substrates are activated catalytically by tertiary amines.","authors":"Prütz, W A","year":1998,"date":"1998 Sep 15","journal":"Archives of biochemistry and biophysics","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The activation of reactions of HOCl with a variety of model substrates by tertiary amines was investigated spectroscopically by tandem-mix and stopped-flow techniques. HOCl-induced chlorination of salicylate can be sped up by several orders of magnitude by catalytic amounts of trimethylamine (TMN). The effect is obviously due to the fast generation of reactive quarternary chloramonium ions, TMN+ Cl, which act as chain carrier in a catalytic reaction cycle. Of various catalysts tested, quinine shows the highest activity; this is attributable to the quinuclidine (QN) substituent, a bicyclic tertiary amine, forming a particularly reactive chloro derivative, QN+ Cl, which does not decompose autocatalytically. The rate of catalytic salicylate chlorination as a function of pH (around pH 7) depends not at least on the basicity of the tertiary amine; the rate increases with pH in the cases of TMN and quinuclidine (high basicity), but decreases with pH in the case of MES (low basicity). Tertiary amines also catalyze the interaction between HOCl and alkenes, as shown using sorbate as model. Reaction of HOCl with the nucleotides GMP and CMP is sped up remarkably by catalytic amounts of tertiary amines. In the case of GMP the same product spectrum is produced by HOCl in absence and presence of catalyst, but a change in the product spectra is obtained when AMP and CMP are reacted with HOCl in presence of catalyst. Using poly(dA-dT).poly(dA-dT) as DNA model, it is shown that HOCl primarily induces an absorbance increase at 263 nm, which indicates unfolding of the double strand due to fast chlorination of thymidine; a subsequent secondary absorbance decrease can be explained by slow chlorination of adenosine. Both the primary and secondary processes are activated by catalytic amounts of quinine. No evidence was found for a radical pathway in TMN-mediated oxidation of formate by HOCl. The present results suggest that low concentrations of certain tertiary amines have the potential of modifying the spectrum of target molecules which can be damaged by HOCl in biological systems.","pmid":"9735167","doi":"10.1006/abbi.1998.0822","url":"https://pubmed.ncbi.nlm.nih.gov/9735167/"},{"id":2805,"title":"Mechanism of depression in cardiac sarcolemmal Na+-K+-ATPase by hypochlorous acid.","authors":"Kato, K; Shao, Q; Elimban, V; Lukas, A; Dhalla, N S","year":1998,"date":"1998 Sep","journal":"The American journal of physiology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Oxidative stress during pathological conditions such as ischemia-reperfusion is known to promote the formation of hypochlorous acid (HOCl) in the heart and to result in depression of cardiac sarcolemmal (SL) Na+-K+-ATPase activity. In this study, we examined the direct effects of HOCl on SL Na+-K+-ATPase from porcine heart. HOCl decreased SL Na+-K+-ATPase activity in a concentration- and time-dependent manner. Characterization of Na+-K+-ATPase activity in the presence of different concentrations of MgATP revealed a decrease in the maximal velocity (Vmax) value, without a change in affinity for MgATP on treatment of SL membranes with 0.1 mM HOCl. The Vmax value of Na+-K+-ATPase, when determined in the presence of different concentrations of Na+, was also decreased, but affinity for Na+ was increased when treated with HOCl. Formation of acylphosphate by SL Na+-K+-ATPase was not affected by HOCl. Scatchard plot analysis of [3H]ouabain binding data indicated no significant change in the affinity or maximum binding capacity value for ouabain binding following treatment of SL membranes with HOCl. Western blot analysis of Na+-K+-ATPase subunits in HOCl-treated SL membranes showed a decrease (34 +/- 9% of control) in the beta1-subunit without any change in the alpha1- or alpha2-subunits. These data suggest that the HOCl-induced decrease in SL Na+-K+-ATPase activity may be due to a depression in the beta1-subunit of the enzyme.","pmid":"9730967","doi":"10.1152/ajpcell.1998.275.3.C826","url":"https://pubmed.ncbi.nlm.nih.gov/9730967/"},{"id":2808,"title":"Rapid monitoring method to assess efficacy of sanitizers against Pseudomonas putida biofilms.","authors":"Chumkhunthod, P; Schraft, H; Griffiths, M W","year":1998,"date":"1998 Aug","journal":"Journal of food protection","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"Biofilms of luminescent Pseudomonas putida were developed on rubber surfaces by incubation in brain heart infusion (BHI) broth. Scanning electron microscopy (SEM) and epifluorescence microscopy (EFM) were used to examine biofilm formation. To test the efficacy of two sanitizers commonly employed in dairy plants for CIP (cleaning in place) procedures, a novel bioluminescence method and aerobic plating were used to enumerate cells. Immediately after the sanitizer treatments an apparent 5-log reduction of biofilm-associated cells was determined. However, when the samples were resuscitated for 18 h in BHI broth, high numbers of cells were detected which reached levels close to those of nontreated controls. The results demonstrated that neither sanitizer could completely eliminate biofilm-associated P. putida. The microbial bioluminescence method proved to be the best way for assessing effectiveness of sanitizers against microbial biofilms.","pmid":"9713769","doi":"10.4315/0362-028x-61.8.1043","url":"https://pubmed.ncbi.nlm.nih.gov/9713769/"},{"id":2809,"title":"A possible involvement of oxidative lung injury in endotoxin-induced bronchial hyperresponsiveness to substance P in guinea pigs.","authors":"Iwamae, S; Tsukagoshi, H; Hisada, T; Uno, D; Mori, M","year":1998,"date":"1998 Aug","journal":"Toxicology and applied pharmacology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Reactive oxygen-derived free radical species have been implicated in the pathogenesis and pathophysiology of inflammatory lung diseases. In a guinea pig model of aerosolized endotoxin-induced bronchial hyperresponsiveness to substance P, a possible involvement of oxidative lung injury was assessed by measuring the changes in membrane-bound neutral endopeptidase activity in the airway tissues and the level of lipid peroxides in the plasma. Vehicle-treated animals developed a neutrophilic airway inflammation, bronchial hyperresponsiveness to substance P associated with neutral endopeptidase hypoactivity, and elevation of lipid peroxides at 18 to 24 h after an exposure to endotoxin (75 microgram/ml, 40 min). A nonselective phosphodiesterase inhibitor, aminophylline, and selective phosphodiesterase isoenzyme inhibitors, SDZ-ISQ-844 (type III/IV) and SDZ-MKS-492 (type III), attenuated the neutrophilic airway inflammation induced by endotoxin. Aminophylline, SDZ-MKS-492, and a superoxide anion-generating NADPH-oxidase inhibitor apocynin inhibited bronchial hyperresponsiveness to substance P with attenuation of neutral endopeptidase inactivation induced by endotoxin. SDZ-ISQ-844, SDZ-MKS-492, and apocynin attenuated the elevation of lipid peroxides. The generation of hypochlorite (OCl-) from whole blood leukocytes was attenuated by aminophylline, SDZ-ISQ-844, SDZ-MKS-492, and apocynin at 1 to 2 h after exposure. These results suggest that reactive oxygen-derived free radical species-mediated oxidative lung injury may play an important role in endotoxin-induced bronchial hyperresponsiveness to substance P, and that phosphodiesterase isoenzyme inhibitors may be potentially useful as anti-inflammatory drugs.","pmid":"9707501","doi":"10.1006/taap.1998.8476","url":"https://pubmed.ncbi.nlm.nih.gov/9707501/"},{"id":2810,"title":"Myeloperoxidase and horseradish peroxidase catalyze tyrosine nitration in proteins from nitrite and hydrogen peroxide.","authors":"Sampson, J B; Ye, Y; Rosen, H; Beckman, J S","year":1998,"date":"1998 Aug 15","journal":"Archives of biochemistry and biophysics","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Nitration of tyrosine residues in proteins occurs in a wide range of inflammatory diseases involving neutrophil and macrophage activation. We report that both myeloperoxidase (MPO) and horseradish peroxidase (HRP) utilize nitrite (NO2-) and hydrogen peroxide (H2O2) as substrates to catalyze tyrosine nitration in proteins. MPO was approximately 10 times more effective than HRP as a nitration catalyst of bovine serum albumin (BSA). Nitration of BSA by MPO did not require chloride as a cofactor. Physiologic levels of chloride did not significantly inhibit nitration by MPO. Oxidation of chloride to hypochlorous acid (HOCl) is catalyzed by MPO but not by HRP, yet HRP also catalyzed nitration from hydrogen peroxide plus nitrite. Therefore, HOCl formation was not obligatory for tyrosine nitration. Although HOCl plus nitrite can nitrate the amino acid tyrosine in simple solutions, protein nitration by HOCl plus nitrite was not observed in heart homogenates, probably due to the presence of multiple alternative targets of both HOCl and HOCl plus nitrite. In contrast, MPO catalyzed nitration of many proteins in rat heart homogenates using NO2- plus H2O2, suggesting that peroxidase-catalyzed nitration of tyrosine could occur in the presence of competing substrates in vivo. HOCl could substitute for H2O2 as the oxidizing substrate for nitration of either BSA or tissue homogenates catalyzed by either peroxidase. Activated neutrophils may generate nitrotyrosine by several mechanisms, including peroxynitrite, HOCl plus nitrite, and a chloride-independent mechanism involving MPO, nitrite, and hydrogen peroxide.","pmid":"9705211","doi":"10.1006/abbi.1998.0772","url":"https://pubmed.ncbi.nlm.nih.gov/9705211/"},{"id":2811,"title":"[The effect of pH on hypochlorite-induced peroxidation of phospholipid liposomes].","authors":"Panasenko, O M; Arnhold, J; Sergienko, V I","year":1998,"date":"1998 May-Jun","journal":"Biofizika","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"In order to make a further sight into mechanism of hypochlorite (HOCl/OCl-)-induced lipid peroxidation we investigated the effect of pH of incubation medium on accumulation of lipid peroxidation products and also on kinetics of HOCl/OCl- decay and disappearance of double bonds during incubation of egg yolk phosphatidylcholine liposomes with hypochlorite. On the one hand, the increase in pH values led to decrease of the rate of a reaction of hypochlorite with double bonds of phosphatidylcholine acyl chains and, on the other hand, to increase in accumulation of primary (conjugated dienes and lipid peroxides) and secondary (TBA-reactive substances) products of lipid peroxidation. The present data and our previous results allow to suppose that besides the electrophilic addition of HOCl to double bonds another reaction of HOCl/OCl- with some lipid intermediate occurs that leads to initiation of free radical processes of lipid peroxidation. This reaction increases in velocity as pH rises at least in the range from 6.50 to 8.15. The role of intermediate may be performed by organic hydroperoxides which are known to be present in some proportion in lipid phase in vivo.","pmid":"9702338","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/9702338/"},{"id":2813,"title":"Salicylate hydroxylation as an indicator of hydroxyl radical generation in dextran sulfate-induced colitis.","authors":"Blackburn, A C; Doe, W F; Buffinton, G D","year":1998,"date":"1998 Aug","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Reactive oxygen and nitrogen species have been implicated as mediators of mucosal injury in inflammatory bowel disease. This study investigated hydroxyl radical (.OH) generation in the inflamed colon of dextran sulfate sodium (DSS)-induced colitis by measuring the .OH-specific product of salicylate hydroxylation, 2,3-dihydroxybenzoic acid (DHB). Colitis was induced in 6-7 week old CBA/H male mice by supplementing the drinking water with 5% DSS for 7 days. On the last day of dextran exposure, mice were injected with salicylate (SAL) (100 mg/kg i.p.) 60 min before sacrifice, and mucosal homogenates were assayed for SAL and 2,3-DHB by HPLC with fluorescence and electrochemical detection. Mucosal 2,3-DHB levels in mice exposed to 5% DSS were increased by 83% (p < .005); however, SAL levels were also elevated by 182% (p < .001). This translated to a 34% decrease in the ratio 2,3-DHB:SAL in inflamed mucosa, possibly indicating greater catabolism or decreased production of 2,3-DHB. In vitro investigation of the stability of DHBs and SAL in the presence of oxidants of inflammatory lesions revealed that 2,3-DHB and 2,5-DHB were rapidly degraded by hypochlorous acid (HOCl), with initial decomposition rates of 190 and 281 nmol/min, respectively (100microM DHB with 200microM HOCl). Methionine prevented decomposition of DHBs in vitro; however, in mice with 5% DSS-induced colitis, where mucosal myeloperoxidase activity was ten-fold control levels (p < .001), administration of methionine (up to 200 mg/kg i.p.) with SAL was ineffective at increasing the ratio 2,3-DHB:SAL. SAL was also degraded in vitro by HOCl (4.7 nmol/min) resulting in the formation of new fluorescent species which may be useful as indicators of HOCl-mediated injury. Salicylate hydroxylation was unable to provide conclusive evidence supporting a role for .OH in the tissue injury of DSS-induced colitis, as metabolic disturbances in the diseased animals other than changes in .OH generation may have altered 2,3-DHB levels. This problem is relevant to any study involving the in vivo use of trapping molecules. In particular, the susceptibility of 2,3-DHB to degradation by HOCl brings into question the usefulness of salicylate hydroxylation for measurement of .OH-generation in any neutrophilic inflammatory lesion.","pmid":"9680176","doi":"10.1016/s0891-5849(98)00068-9","url":"https://pubmed.ncbi.nlm.nih.gov/9680176/"},{"id":2814,"title":"Evidence for roles of radicals in protein oxidation in advanced human atherosclerotic plaque.","authors":"Fu, S; Davies, M J; Stocker, R; Dean, R T","year":1998,"date":"1998 Aug 1","journal":"The Biochemical journal","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Oxidative damage might be important in atherogenesis. Oxidized lipids are present at significant concentrations in advanced human plaque, although tissue antioxidants are mostly present at normal concentrations. Indirect evidence of protein modification (notably derivatization of lysine) or oxidation has been obtained by immunochemical methods; the specificities of these antibodies are unclear. Here we present chemical determinations of six protein-bound oxidation products: dopa, o-tyrosine, m-tyrosine, dityrosine, hydroxyleucine and hydroxyvaline, some of which reflect particularly oxy-radical-mediated reaction pathways, which seem to involve mainly the participation of transition- metal ions. We compared the relative abundance of these oxidation products in normal intima, and in human carotid plaque samples with that observed after radiolytically generated hydroxyl radical attack on BSA in vitro. The close similarities in relative abundances in the latter two circumstances indicate that hydroxyl radical damage might occur in plaque. The relatively higher level of dityrosine in plaque than that observed after radiolysis suggests the additional involvement of HOCl-mediated reactions in advanced plaque.","pmid":"9677308","doi":"10.1042/bj3330519","url":"https://pubmed.ncbi.nlm.nih.gov/9677308/"},{"id":2816,"title":"Association of myeloperoxidase with heparin: oxidative inactivation of proteins on the surface of endothelial cells by the bound enzyme.","authors":"Daphna, E M; Michaela, S; Eynat, P; Irit, A; Rimon, S","year":1998,"date":"1998 Jun","journal":"Molecular and cellular biochemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Chromatography of human myeloperoxidase (MPO) on a heparin-agarose column demonstrated a tight association of the protein with the resin. The electrophoretic mobility of mixtures of MPO and heparin in polyacrylamide gels under nondenaturing conditions was consistent with a strong interaction of the cationic enzyme with the polyanionic polysaccharide. Purified MPO prebound to bovine aorta endothelial cells (BAEC) and supplemented with hydrogen peroxide dose- and time-dependently abrogated the interaction of coagulation factor IX (FIX) with factor IX-binding protein (FIXBP) on the surface of BAEC reflecting oxidative modification of the binding protein. This inactivation of FIXBP required the presence of chloride implicating hypochlorite in the reaction. Hypochlorite and activated neutrophils exerted a similar effect. The oxidative modification of FIXBP was only partially dependent on the addition of hydrogen peroxide and was abolished by exogenous heparin which displaced MPO from the cell surface, emphasizing the functional differences between cell-bound and free enzyme.","pmid":"9655178","doi":"10.1023/a:1006848730927","url":"https://pubmed.ncbi.nlm.nih.gov/9655178/"},{"id":2817,"title":"Reactivity of cartilage and selected carbohydrates with hydroxyl radicals: an NMR study to detect degradation products.","authors":"Schiller, J; Arnhold, J; Schwinn, J; Sprinz, H; Brede, O; Arnold, K","year":1998,"date":"1998 Feb","journal":"Free radical research","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"It was investigated to what extent isolated, monomeric and polymeric carbohydrates as well as cartilage specimens are affected by hydroxyl radicals generated by gamma-irradiation or Fenton reaction and what products can be detected by means of NMR spectroscopy. Resonances of all protons in glucose and other monosaccharides as well as carbon resonances in 13C-enriched glucose were continuously diminished upon gamma-irradiation. Formate and malondialdehyde were found as NMR detectable products in irradiated glucose solutions under physiologically relevant (aerated) conditions. In polysaccharide solutions (e.g. hyaluronic acid) gamma-irradiation and also treatment with the Fenton reagent caused first an enhancement of resonances according to mobile N-acetyl groups at 2.02 ppm. This indicates a breakdown of glycosidic bonds in polysaccharides. Using higher radiation doses or higher concentrations of the Fenton reagent formate was also detected. The same sequence of events was observed upon treatment of bovine nasal cartilage with the Fenton reagent. First, glycosidic linkages in cartilage polysaccharides were cleaved and subsequently formate was formed. In contrast, collagen of cartilage was affected only to a very low extent. Thus, HO-radicals caused the same action on cartilage as on isolated polymer solutions, inducing a fragmentation of polysaccharides and the formation of formate.","pmid":"9645397","doi":"10.3109/10715769809065806","url":"https://pubmed.ncbi.nlm.nih.gov/9645397/"},{"id":2819,"title":"Degradation of hyaluronic acid, poly- and monosaccharides, and model compounds by hypochlorite: evidence for radical intermediates and fragmentation.","authors":"Hawkins, C L; Davies, M J","year":1998,"date":"1998 Jun","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Degradation of hyaluronic acid by oxidants such as HO. and HOCl/CIO- is believed to be important in the progression of rheumatoid arthritis. While reaction of hyaluronic acid with HO. has been investigated extensively, reaction with HOCl/ClO- is less well defined. Thus, little is known about the site(s) of HOCl/ClO- attack, the intermediates formed, or the mechanism(s) of polymer degradation. In this study reaction of HOCl/ClO- with amides, sugars, polysaccharides, and hyaluronic acid has been monitored by UV-visible (220-340 nm) and EPR spectroscopy. UV-visible experiments have shown that HOCl/ClO- reacts preferentially with N-acetyl groups. This reaction is believed to give rise to transient chloramide (R-NCl-C(O)-R') species, which decompose rapidly to give radicals via either homolysis (to produce N. and Cl.) or heterolysis (one-electron reduction, to give N. and Cl.) of the N--C bond. The nature of the radicals formed has been investigated by EPR spin trapping. Reaction of HOCl/ClO- with hyaluronic acid, chondroitin sulphates A and C, N-acetyl sugars, and amides gave novel, carbon-centered, spin adducts, the formation of which is consistent with selective initial attack at the N-acetyl group. Thus, reaction with hyaluronic acid and chondroitin sulphate A, appears to be localized at the N-acetylglucosamine sugar rings. These carbon-centered radicals are suggested to arise from rapid rearrangement of initial nitrogen-centered radicals, formed from the N-acetyl chloramide, by reactions analogous to those observed with alkoxyl radicals. The detection of increasing yields of low-molecular-weight radical adducts from hyaluronic acid and chondroitin sulphate A with increasing HOCl/ClO-concentrations suggests that formation of the initial nitrogen-centered species on the N-acetylglucosamine rings, and the carbon-centered radicals derived from them, brings about polymer fragmentation.","pmid":"9641257","doi":"10.1016/s0891-5849(98)00009-4","url":"https://pubmed.ncbi.nlm.nih.gov/9641257/"},{"id":2820,"title":"Free radical-scavenging properties of olive oil polyphenols.","authors":"Visioli, F; Bellomo, G; Galli, C","year":1998,"date":"1998 Jun 9","journal":"Biochemical and biophysical research communications","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Plants in the Mediterranean basin, such as vine and olive trees, have developed an array of antioxidant defences to protect themselves from environmental stress. Accordingly, the incidence of coronary heart disease and certain cancers is lower in the Mediterranean area, where olive oil is the dietary fat of choice. As opposed to other vegetable oils, extra virgin olive oil, which is obtained by physical pressure from a whole fruit, is rich in phenolic components that are responsible for the particular stability of the oil. We have investigated the scavenging actions of some olive oil phenolics, namely hydroxytyrosol and oleuropein, with respect to superoxide anion generation, neutrophils respiratory burst, and hypochlorous acid. The low EC50S indicate that both compounds are potent scavengers of superoxide radicals and inhibitors of neutrophils respiratory burst: whenever demonstrated in vivo, these properties may partially explain the observed lower incidence of CHD and cancer associated with the Mediterranean diet.","pmid":"9636654","doi":"10.1006/bbrc.1998.8735","url":"https://pubmed.ncbi.nlm.nih.gov/9636654/"},{"id":2824,"title":"A comparison of the oxidation of clozapine and olanzapine to reactive metabolites and the toxicity of these metabolites to human leukocytes.","authors":"Gardner, I; Zahid, N; MacCrimmon, D; Uetrecht, J P","year":1998,"date":"1998 Jun","journal":"Molecular pharmacology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Olanzapine was shown to be oxidized to a reactive intermediate by HOCl, which is the major oxidant produced by activated neutrophils. A mass spectrum obtained using a flow system in which the reactants were fed into a mixing chamber and the products flowed directly into a mass spectrometer revealed a reactive intermediate at m/z 311. This is 2 mass units less than the protonated molecular ion of parent olanzapine and suggests that the reactive intermediate is a nitrenium ion. The reactive intermediate could be trapped with glutathione or N-acetylcysteine to produce two conjugates. These data are analogous to results we reported previously with the structurally related atypical antipsychotic agent clozapine. However, the clozapine and olanzapine reactive metabolites showed differences in their ability to cause toxicity to human neutrophils. Toxicity to neutrophils was observed only at high concentrations of clozapine (>50 microM) when HOCl was used to generate reactive metabolite. In contrast, concentration-dependent toxicity (p < 0.05) was observed when neutrophils were incubated with clozapine (0-20 microM) and H2O2 to generate clozapine reactive metabolite. No toxicity was observed with clozapine alone (at concentrations of > 50 microM). Similar results were observed in monocytes and HL-60 cells. Olanzapine reactive metabolite only seemed to cause slight toxicity at the highest concentrations tested (20 microM), even when the reactive metabolite was generated using H2O2. Neutrophils from two patients with a history of clozapine-induced agranulocytosis seemed to be more sensitive to the toxic effects of the clozapine reactive metabolite; however, the numbers are too small to draw any definite conclusions.","pmid":"9614200","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/9614200/"},{"id":2825,"title":"Hypochlorite-induced damage to proteins: formation of nitrogen-centred radicals from lysine residues and their role in protein fragmentation.","authors":"Hawkins, C L; Davies, M J","year":1998,"date":"1998 Jun 15","journal":"The Biochemical journal","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Stimulated monocytes and neutrophils generate hypochlorite (HOCl) via the release of the enzyme myeloperoxidase and hydrogen peroxide. HOCl damages proteins by reaction with amino acid side-chains or backbone cleavage. Little information is available about the mechanisms and intermediates involved in these reactions. EPR spin trapping has been employed to identify radicals on proteins, peptides and amino acids after treatment with HOCl. Reaction with HOCl gives both high- and low-molecular-mass nitrogen-centred, protein-derived radicals; the yield of the latter increases with both higher HOCl:protein ratios and enzymic digestion. These radicals, which arise from lysine side-chain amino groups, react with ascorbate, glutathione and Trolox. Reaction of HOCl-treated proteins with excess methionine eliminates radical formation, which is consistent with lysine-derived chloramines (via homolysis of N-Cl bonds) being the radical source. Incubation of HOCl-treated proteins, after removal of excess oxidant, gives rise to both nitrogen-centred radicals, over a period of hours, and time-dependent fragmentation of the protein. Treatment with excess methionine or antioxidants (Trolox, ascorbate, glutathione) protects against fragmentation; urate and bilirubin do not. Chloramine formation and nitrogen-centred radicals are therefore key species in HOCl-induced protein fragmentation.","pmid":"9620862","doi":"10.1042/bj3320617","url":"https://pubmed.ncbi.nlm.nih.gov/9620862/"},{"id":2828,"title":"Functional sites of chemically modified tetracyclines: inhibition of the oxidative activation of human neutrophil and chicken osteoclast pro-matrix metalloproteinases.","authors":"Sorsa, T; Ramamurthy, N S; Vernillo, A T; Zhang, X; Konttinen, Y T; Rifkin, B R; Golub, L M","year":1998,"date":"1998 May","journal":"The Journal of rheumatology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVE: We studied the relative ability of 6 different chemically modified non-antimicrobial analogs of tetracycline (CMT) to inhibit human and chicken matrix metalloproteinases (MMP) in vitro. The ability of tetracycline and its analogs to inhibit MMP appears to depend on the Ca++/Zn++ binding site at C11 (carbonyl oxygen) and C12 (OH group) of the molecule, which is lacking in CMT-5, the pyrazole derivative of tetracycline. This significant property of CMT-5 was used to differentiate between the effects of CMT on already active MMP versus the oxidative activation of latent MMP (pro-MMP). METHODS: Cultured chicken osteoclast conditioned medium and purified human neutrophil progelatinase (MMP-9) and pro-collagenase (MMP-8) were assayed for proteinase activities using gelatin and collagen, respectively. The pro-MMP were activated either by preincubation with 1 mM aminophenylmercuric acetate (APMA) or 100 microM sodium hypochlorite (NaOCI). CMT were added either to the preincubation mixtures together with NaOCl or after activation of pro-MMP with NaOCl. RESULTS: All CMT tested, except CMT-5, inhibited APMA or NaOCl activated pro-MMP. However, CMT-5 (like the other CMT), inhibited the oxidative activation of pro-MMP by NaOCl when added together by scavenging the reactive oxygen species. The degradation of type-I collagen by chicken osteoclast conditioned medium was probably due to MMP-2 and/or MMP-13. CONCLUSION: Oxidative activation of pro-MMP may be crucial during soft tissue/bone destruction in the inflammatory diseases, including the arthritides. Our results indicate that the Ca++/Zn++ binding site of CMT is not essential for inhibition of the oxidative activation of pro-MMP.","pmid":"9598901","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/9598901/"},{"id":2829,"title":"Formation of carbonyls during attack on insulin by submolar amounts of hypochlorite.","authors":"Handelman, G J; Nightingale, Z D; Dolnikowski, G G; Blumberg, J B","year":1998,"date":"1998 May 1","journal":"Analytical biochemistry","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Bovine insulin was reacted at pH 4.0 with submolar amounts of hypochlorite. At least one molecule of insulin was modified per two molecules of hypochlorite added, as estimated by HPLC of native and modified insulin. About 5% of the hypochlorite-modified insulin reacted with dinitrophenylhydrazine (DNPH), a reagent which specifically labels carbonyl groups. The major DNPH-labeled product was isolated from the native insulin on reverse-phase HPLC, using trifluoroacetic acid/water/acetonitrile gradients. The UV spectrum of the major peak on the HPLC diode-array detector was representative of DNPH adducts, with lambda max = 365 nm. Several methods, including total amino acid analysis, tryptic digestion, and collision-induced dissociation-electrospray MS, indicate that the major carbonyl in the DNPH-labeled product was on the amino-terminal phenylalanine of the insulin B-chain. Amino acid analysis indicated that tyrosine was also degraded by hypochlorite, but we could not detect a carbonyl group formed at tyrosine. These findings suggest that the terminal amino groups of proteins are highly vulnerable to carbonyl formation during hypochlorite attack. The use of relatively low amounts of active oxygen species (such as hypochlorite), followed by chromatographic isolation of the protein labeled with a carbonyl-specific reagent, can be a useful approach to the study of reactive sites on proteins.","pmid":"9570850","doi":"10.1006/abio.1998.2592","url":"https://pubmed.ncbi.nlm.nih.gov/9570850/"},{"id":2830,"title":"Protective effects of carnosine against protein modification mediated by malondialdehyde and hypochlorite.","authors":"Hipkiss, A R; Worthington, V C; Himsworth, D T; Herwig, W","year":1998,"date":"1998 Mar 12","journal":"Biochimica et biophysica acta","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Malondialdehyde (MDA) and hypochlorite anions are deleterious products of oxygen free-radical metabolism. The effects of carnosine, a naturally occurring dipeptide (beta-alanyl-L-histidine), on protein modification mediated by MDA and hypochlorite have been studied. MDA and hypochlorite induced formation of carbonyl groups and high molecular weight and cross-linked forms of crystallin, ovalbumin and bovine serum albumin. The presence of carnosine effectively inhibited these modifications in a concentration-dependent manner. It is proposed that relatively non-toxic carnosine and related peptides might be explored as potential therapeutic agents for pathologies that involve protein modification mediated by MDA or hypochlorite.","pmid":"9545530","doi":"10.1016/s0304-4165(97)00123-2","url":"https://pubmed.ncbi.nlm.nih.gov/9545530/"},{"id":2834,"title":"Antibiotics commonly used to treat mastitis and respiratory burst of bovine polymorphonuclear leukocytes.","authors":"Hoeben, D; Burvenich, C; Heyneman, R","year":1998,"date":"1998 Feb","journal":"Journal of dairy science","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The in vitro effects of six doses (2 x 10(-3) to 2 x 10(-8) M) of antimicrobial drugs that are frequently used in udder infusions on the capacity of bovine blood polymorphonuclear neutrophilic leukocytes to generate reactive oxygen species were studied by the measurement of luminol-dependent chemiluminescence after stimulation with phorbol 12-myristate 13-acetate. All drugs, except cloxacillin, significantly decreased chemiluminescence at the highest dose. Doxycyline induced the most severe inhibition, followed by neomycin and dihydrostreptomycin. The effect of ampicillin was due to the scavenging of reactive oxygen species and interactions with luminol. The inhibition observed with oleandomycin, neomycin, lincomycin, and dihydrostreptomycin was not due to direct effects on the production of oxidative metabolites but rather to interference with other components involved in the production of light, such as interference with the interaction between luminol and the myeloper-oxidase-H2O2-halide system. The deleterious effects of doxycycline can be explained by several factors: decreased production of superoxide, yellow color, the scavenging of reactive oxygen species, and Ca2+ chelating effect. In conclusion, the results of this study show that antibiotics may affect neutrophil function at concentrations that are reached in the mammary gland after local and repeated administration.","pmid":"9532493","doi":"10.3168/jds.S0022-0302(98)75590-0","url":"https://pubmed.ncbi.nlm.nih.gov/9532493/"},{"id":2836,"title":"Oxidant-scavenging activities of beta-lactam agents.","authors":"Carreer, R; Deby-Dupont, G; Deby, C; Jadoul, L; Mathy, M","year":1998,"date":"1998 Jan","journal":"European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The relative antioxidant effect of ampicillin, ceftazidime, ceftriaxone, and cefuroxime on oxygen-reactive species was examined in vitro using stimulated human polymorphonuclear neutrophils. There was no evidence that any of the beta-lactam agents tested had an effect on superoxide or H2O2 generation. In contrast, all of the beta-lactam agents prevented hypochlorous acid (HOCI) chlorination of 1,1-dimethyl-4-chloro-3,5-cyclo-hexanedione in a cell-free system at concentrations of < 10 microg/ml. Furthermore, all antibiotics provided dose-dependent protection against HOCI cytotoxicity to 16HBE140 bronchial epithelial cells. Taken together, these data indicate a possible therapeutic role for beta-lactam agents in protecting host tissues from HOCI-induced oxidative damage.","pmid":"9512182","doi":"10.1007/BF01584363","url":"https://pubmed.ncbi.nlm.nih.gov/9512182/"},{"id":2838,"title":"The action of VIRKON No Foam on the hepatitis B virus.","authors":"Scioli, D; Pizzella, T; Vollaro, L; Nardiello, S; De Feo, L","year":1997,"date":"1997 Dec","journal":"European journal of epidemiology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The aim of this work was to verify the in vitro virucidal activity of VIRKON No Foam (VIRKON NF) against the HBV DNA, notoriously one the most resistant viruses to heat and to the most commonly used disinfectants. VIRKON NF, an oxidizing agent, has a synergic effect on nucleic acids, polypeptides, glycoproteins, and structural proteins. The experiment was conducted using the serum of a patient with HBsAg+/HBeAg+/HBVDNA+ with a DNA concentration 100 pg/ml. The virucidal activity was tested using the Slot Blot method, the result being evaluated as an inhibition of the autoradiographic signal because of contact of different concentrated solutions and various contact times with the serum. Preliminary tests were carried out after contact of VIRKON NF with serum solutions at 0.1-0.5-1-4% concentrations for a 15 min contact time. VIRKON NF showed an inhibition of autoradiographic signal equal respectively to 0%, 25-50%, 50-70%, 100%. Further experiments were carried out to compare VIRKON NF virucidal activity on HBV to the activity of the most common disinfectants, such as formic aldehyde, Amuchina, glutaraledhyde and phenol. In this way, the infected serum was put into contact with both the most common disinfectant and 1-1.5-2-3-4% VIRKON NF solutions in contact times of 15, 10, 5, 2 min. Using 3% concentrations for a contact time of 10 min, VIRKON NF showed an autoradiographic inhibition signal of 90%. Regarding other disinfectants, only a 2% glutaraldehyde solution for a contact time of 15 min showed similar virucidal activity.","pmid":"9476816","doi":"10.1023/a:1007399926095","url":"https://pubmed.ncbi.nlm.nih.gov/9476816/"},{"id":2843,"title":"Intraphagosomal chlorination dynamics and yields determined using unique fluorescent bacterial mimics.","authors":"Jiang, Q; Griffin, D A; Barofsky, D F; Hurst, J K","year":1997,"date":"1997 Oct","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Fluorescein was covalently attached through a cystamine linker group to carboxy-derivatized polyacrylamide microspheres to generate phagocytosable particles containing fluorescent reporter groups. A unique feature of these beads is that the dye was recoverable in near-quantitative yield from intracellular environments by thiol reduction of the cystamine disulfide bond. Fluorescence microscopy indicated that individual neutrophils could bind as many as approximately 20 serum-opsonized beads, although no appreciable cellular association was observed for unopsonized beads. By using methyl viologen to quench external fluorescence, it was demonstrated that 70-90% of the neutrophil-associated fluorescein on opsonized beads was inaccessible to the medium. The particle-bound fluorescein underwent near-stoichiometric conversion to chlorinated derivatives when reacted with HOCl or the cell-free myeloperoxidase (MPO)-H2O2-Cl- system; products were identified by HPLC separation and electrospray ionization mass spectrometry of the recovered dye. Fluorescence changes accompanying phagocytosis were consistent with chlorination of the dye; fluorescence spectrometric and chemical trapping measurements indicated that intraphagosomal chlorination was far more extensive than extracellular chlorination. Yields of recovered chlorofluoresceins determined by HPLC indicated that sufficient HOCl had been produced intracellularly to kill entrapped bacteria. Fluorescein chlorination coincided approximately with phagocytosis and stimulated uptake of O2 by the cells. Demonstration that HOCl is produced within phagosomes in sufficient concentrations to kill bacteria on a time scale associated with death constitutes strong evidence in support of a primary role for HOCl in the microbicidal action of neutrophils.","pmid":"9348429","doi":"10.1021/tx9700984","url":"https://pubmed.ncbi.nlm.nih.gov/9348429/"},{"id":2845,"title":"Formation of nitric oxide-derived inflammatory oxidants by myeloperoxidase in neutrophils.","authors":"Eiserich, J P; Hristova, M; Cross, C E; Jones, A D; Freeman, B A; Halliwell, B; van der Vliet, A","year":1998,"date":"1998 Jan 22","journal":"Nature","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Nitric oxide (.NO) plays a central role in the pathogenesis of diverse inflammatory and infectious disorders. The toxicity of .NO is thought to be engendered, in part, by its reaction with superoxide (O2.-), yielding the potent oxidant peroxynitrite (ONOO-). However, evidence for a role of ONOO- in vivo is based largely upon detection of 3-nitrotyrosine in injured tissues. We have recently demonstrated that nitrite (NO2-), a major end-product of .NO metabolism, readily promotes tyrosine nitration through formation of nitryl chloride (NO2Cl) and nitrogen dioxide (.NO2) by reaction with the inflammatory mediators hypochlorous acid (HOCl) or myeloperoxidase. We now show that activated human polymorphonuclear neutrophils convert NO2- into NO2Cl and .NO2 through myeloperoxidase-dependent pathways. Polymorphonuclear neutrophil-mediated nitration and chlorination of tyrosine residues or 4-hydroxyphenylacetic acid is enhanced by addition of NO2- or by fluxes of .NO. Addition of 15NO2- led to 15N enrichment of nitrated phenolic substrates, confirming its role in polymorphonuclear neutrophil-mediated nitration reactions. Polymorphonuclear neutrophil-mediated inactivation of endothelial cell angiotensin-converting enzyme was exacerbated by NO2-, illustrating the physiological significance of these reaction pathways to cellular dysfunction. Our data reveal that NO2- may regulate inflammatory processes through oxidative mechanisms, perhaps by contributing to the tyrosine nitration and chlorination observed in vivo.","pmid":"9450756","doi":"10.1038/34923","url":"https://pubmed.ncbi.nlm.nih.gov/9450756/"},{"id":2847,"title":"Effects of hypochlorous acid and ascorbic acid on conductance, permeability, and structure of equine colonic mucosa in vitro.","authors":"Inoue, O J; Freeman, D E; Wallig, M","year":1998,"date":"1998 Jan","journal":"American journal of veterinary research","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"OBJECTIVES: To study effects of hypochlorous acid (HOCl) on equine colonic mucosa in vitro, and determine whether addition of ascorbic acid protects against the effects. ANIMALS: 6 healthy horses and ponies. PROCEDURE: Short-circuit current was measured in mucosa mounted in Ussing chambers. Incubation conditions were: control (no additions); 5 mM HOCl; 1 mM HOCl; same and 5 mM ascorbic acid; 3 mM HOCl; 3 mM HOCl and 5 mM ascorbic acid; 7 mM HOCl; and 7 mM HOCl plus 5 mM ascorbic acid. Permeability was measured with [3H]mannitol and, at the conclusion of each experiment, tissues were examined microscopically to assess the effects of HOCl and ascorbic acid, alone or in combination. RESULTS: Short-circuit current and conductance increased transiently in response to 1 mM HOCl. Tissues had mild surface epithelial damage, as evident by swelling and separation of isolated cells. These changes were abolished when tissues were coincubated with 5 mM ascorbic acid and 1 mM HOCl. At 3 and 7 mM concentrations, HOCl caused marked increase in tissue conductance, short-circuit current, and permeability to mannitol; these changes were associated with histologic damage. Again, coincubation with 5 mM ascorbic acid protected against these changes. Additional studies indicated that the effects of HOCl and the protective effects of ascorbic acid were not mediated through changes in pH. CONCLUSIONS: HOCl in low concentrations is capable or increasing the short-circuit current in equine colon, possibly by increasing secretions; however, higher concentrations can cause tissue damage. The addition of 5 mM ascorbic acid blocks these changes. CLINICAL RELEVANCE: The concentration of HOCl produced by activated neutrophils could damage equine colonic mucosa and potentially contribute to or cause reperfusion injury. The ability of ascorbic acid to ameliorate this injury in an in vitro setting offers a potential method for pharmacologic evaluation of this injury and for treatment.","pmid":"9442250","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/9442250/"},{"id":2848,"title":"Interactions of hypochlorous acid with pyrimidine nucleotides, and secondary reactions of chlorinated pyrimidines with GSH, NADH, and other substrates.","authors":"Prütz, W A","year":1998,"date":"1998 Jan 1","journal":"Archives of biochemistry and biophysics","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"HOCl-induced chlorination of pyrimidine nucleotides, PyNH, strikingly depends on the nature of the available chlorine acceptor group. For CMP, with an -NH2 group as acceptor, the reaction is slow and involves predominantly the acid [k(CMP + HOCl) approximately 100 M-1 s-1 at pH 6]; apparent rate constants of the reaction decrease around the pK alpha (HOCl), to 0 in alkaline solution. For TMP and UMP, with a heterocyclic > NH group (at 3N) as acceptor, the reaction is faster and involves mainly the conjugated CIO- anion [e.g., k(UMP + ClO-) approximately 3 x 10(4) M-1 s-1 and k(UMP + HOCl) approximately 200 M-1 s-1]. The 3-N-methylthymidine derivative is inert toward HOCl. Reactions of ClO- with TMP, UMP, and poly(U) are shown to be reversible, PyNH + ClO- = PyNCl + OH-; an increase in pH due to this reaction was confirmed, and equilibrium constants have been estimated. The chlorinated derivatives of TMP and UMP are very reactive toward GSH, disulfide, aliphatic amines, and NADH. In contrast, the PyNCl derivative of CMP is unreactive, except with GSH. Rate constants of reactions of PyNCl species with various substrates are presented. Oxidation of NADH, by both HOCl and PyNCl derivatives, leads to a stable product (not NAD+) which is irreversibly degraded by reaction with excess HOCl, but inert toward acsorbate, GSH, and H2O2. Thiols (GSH) and disulfides (DTPA) were previously found capable of scavenging up to four HOCl molecules (Prütz, W. A., Arch. Biochem. Biophys. 332, 110-120, 1996). In the present study it was established that reactions of GSH or DTPA with excess HOCl give rise to a rapid drop in the pH by release of up to four HCl molecules per GSH or DTPA, as expected for a sequence of consecutive sulfoxidations. Reactions of GSH and DTPA with PyNCl efficiently regenerate PyNH, namely up to four molecules per GSH or DTPA in the case of TMP and UMP, but only one molecule per GSH in the case of CMP. The PyNCl derivatives of TMP and UMP transfer chlorine slowly but completely to CMP or AMP. Such chlorine transfer between nucleic acid bases is likely to occur also in DNA; it is shown that HOCl in fact induces a complex series of reactions on interaction with native DNA.","pmid":"9439597","doi":"10.1006/abbi.1997.0440","url":"https://pubmed.ncbi.nlm.nih.gov/9439597/"},{"id":2853,"title":"Hypochlorous acid-induced base modifications in isolated calf thymus DNA.","authors":"Whiteman, M; Jenner, A; Halliwell, B","year":1997,"date":"1997 Nov","journal":"Chemical research in toxicology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Exposure of calf thymus DNA to hypochlorous acid/hypochlorite leads to extensive DNA base modification. Large concentration-dependent increases in pyrimidine oxidation products [thymine glycol (cis/trans), 5-hydroxycytosine, 5-hydroxyuracil, 5-hydroxyhydantoin] but not purine oxidation products (8-hydroxyguanine, 2- and 8-hydroxyadenine, FAPy guanine, FAPy adenine) were observed at pH 7.4. In addition, large increases in 5-chlorouracil (probably formed from 5-chlorocytosine during sample preparation), a novel chlorinated base, were observed. Addition of HOCl to DNA already damaged by .OH generated by a mixture of ascorbate, copper(II) chloride, and hydrogen peroxide showed that hypochlorous acid led to a loss of 8-hydroxyguanine, 2- and 8-hydroxyadenine, FAPy guanine, FAPy adenine, and 5-hydroxycytosine in a concentration- and pH-dependent manner. Nevertheless, time course studies suggested that the formation of purine oxidation products in isolated DNA by hypochlorous acid was not a major oxidation pathway. If this pattern of damage, especially the production of 5-chlorocytosine, is unique to hypochlorous acid, it might act as a \"fingerprint\" of damage to DNA by HOCl.","pmid":"9403176","doi":"10.1021/tx970086i","url":"https://pubmed.ncbi.nlm.nih.gov/9403176/"},{"id":2854,"title":"Reaction of hypochlorous acid with bovine nasal cartilage comparison to pig articular cartilage.","authors":"Schiller, J; Arnhold, J; Zachäus, A; Arnold, K","year":1997,"date":"1997 Sep-Oct","journal":"Zeitschrift fur Naturforschung. C, Journal of biosciences","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The action of sodium hypochlorite (NaOCl) on bovine nasal cartilage was studied by proton nuclear magnetic resonance (1H-NMR) spectroscopy in order to model degradation processes of cartilage caused by neutrophil-derived hypochlorous acid. Nasal cartilage was chosen as a mean of comparison because it differs from articular cartilage in its composition. It contains some more proteoglycans, i.e. polymeric carbohydrates and less collagen than articular cartilage. This is important for studying the influence of hypochlorous acid on cartilage components (collagen and polysaccharides). Cartilage samples were incubated at 37 degrees C with phosphate buffer in the presence or absence of NaOCl. Supernatants were collected and assayed by NMR-spectroscopy. In the presence of pure phosphate buffer, the supernatants of bovine nasal cartilage were less rich in low molecular mass metabolites (e.g. amino acids, lactate) than articular cartilage. However, intense signals for highly mobile N acetyl groups of cartilage polysaccharides were detectable in nasal cartilage. NaOCl caused an increase in signals for acetate and formiate. Signals for N-acetyl groups rose only during the first 25 minutes of incubation with NaOCl. Then, their concentration decreased markedly. These changes were related to an enhanced release of chondroitinsulfate from nasal cartilage.","pmid":"9373999","doi":"10.1515/znc-1997-9-1019","url":"https://pubmed.ncbi.nlm.nih.gov/9373999/"},{"id":2857,"title":"Contrasting effects of hypochlorous acid and hydrogen peroxide on endothelial permeability: prevention with cAMP drugs.","authors":"Ochoa, L; Waypa, G; Mahoney, J R Jr; Rodriguez, L; Minnear, F L","year":1997,"date":"1997 Oct","journal":"American journal of respiratory and critical care medicine","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Activated polymorphonuclear leukocytes generate a cascade of reduced oxygen metabolites. In addition to their antimicrobial role, hydrogen peroxide (H2O2) and hypochlorous acid (HOCl) function as inflammatory mediators and increase the protein permeability of the vascular endothelium. The objectives of the present study were to compare the effects of H2O2 and HOCl with respect to relative potencies and the time course and magnitude of changes in cell shape and permeability of endothelial cell monolayers derived from bovine pulmonary artery, to determine if HOCl produced by conversion of H2O2 with myeloperoxidase and Cl- produces comparable results as the direct administration of HOCl, and to show that adenosine 3',5'-cyclic monophosphate (cAMP)-enhancing agents can prevent the increased endothelial permeability induced by HOCl and H2O2. HOCl given directly or produced by myeloperoxidase, H2O2, and Cl- caused faster and greater changes in cell shape (cell retraction), electrical resistance, and protein permeability (125I-labeled albumin clearance) of endothelial cell monolayers than induced by H2O2. HOCl (10 to 100 microM) induced these changes within 1 to 3 min, whereas H2O2 (50 to 400 microM) required approximately 30 min. 8-Bromo-cAMP prevented the increased endothelial protein permeability induced by HOCl or H2O2, but isoproterenol only prevented the H2O2 response. Thus, HOCl at a much lower concentration caused a faster and greater increase in endothelial permeability in vitro than H2O2, and an increased intracellular level of cAMP prevented the increased permeability induced by either oxidant.","pmid":"9351629","doi":"10.1164/ajrccm.156.4.96-10115","url":"https://pubmed.ncbi.nlm.nih.gov/9351629/"},{"id":2862,"title":"Cyanate-mediated inhibition of neutrophil myeloperoxidase activity.","authors":"Qian, M; Eaton, J W; Wolff, S P","year":1997,"date":"1997 Aug 15","journal":"The Biochemical journal","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Cyanate (CNO-) forms spontaneously in solutions containing urea, and is present in urine and the body fluids of uraemic patients. We have explored the possibility that CNO- might be one of the unknown substances responsible for the reported impairment, by urine and uraemic plasma, of neutrophil oxidative metabolism (especially as measured by luminol-enhanced chemiluminescence). Luminol-enhanced chemiluminescence generated by human neutrophils derives predominantly from the activity of myeloperoxidase (MPO) which produces hypochlorous acid from H2O2 and Cl-. We hypothesized that CNO- (which resembles the 'pseudohalide' thiocyanate, an alternative substrate for MPO) might somehow interfere with the activity of MPO. In support of this, we find: (i) CNO- inhibits both peroxidative and halogenating activities of MPO and also inhibits the enzyme within intact human neutrophils; (ii) the inhibition is H2O2-dependent, irreversible, accompanied by covalent addition of [14C]CNO- (or a carbon-containing fragment thereof) to the enzyme; (iii) CNO- also inhibits Cl-/H2O2/MPO-mediated bacterial killing. Impairment of this arm of neutrophil bactericidal activity by CNO- formed from urea may be one factor in the risk of urinary-tract infection associated with urinary stasis and perhaps in the generalized increase in susceptibility to infection in uraemic patients.","pmid":"9337863","doi":"10.1042/bj3260159","url":"https://pubmed.ncbi.nlm.nih.gov/9337863/"},{"id":2864,"title":"Nitric oxide and antimicrobial activity of reactive oxygen intermediates.","authors":"Marcinkiewicz, J","year":1997,"date":"1997 Aug","journal":"Immunopharmacology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"It is well documented that nitric oxide contributes to the bactericidal activities of phagocytes. Murine activated neutrophils and macrophages produce both reactive oxygen intermediates (ROI) and reactive nitrogen intermediates (RNI). However, only neutrophils in the presence of myeloperoxidase, produce an antimicrobial agent, hypochlorous acid (HOCl). Complex interactions of RNI (nitric oxide) with other antimicrobial agents of phagocytes are likely to exist, but these have not been clearly demonstrated. In this study, we treated bacteria (Escherichia coli) with the NO donor, S-nitrosoglutathione (GSNO) and hydrogen peroxide (H2O2) or HOCl. We found that exposure to H2O2 of the bacteria tested resulted in minimal toxicity. However the killing activities of H2O2 were potentiated by GSNO. On the contrary, the NO-donor completely abolished the bactericidal activity of HOCl. Our results indicate that NO-donating drugs in non toxic concentrations used for experimental purposes may strongly affect the cytotoxic activity of neutrophils and macrophages. We suggest that the similar interactions may exist at sites of inflammation.","pmid":"9285242","doi":"10.1016/s0162-3109(96)00168-3","url":"https://pubmed.ncbi.nlm.nih.gov/9285242/"},{"id":2866,"title":"Hypochlorite-induced peroxidation of egg yolk phosphatidylcholine is mediated by hydroperoxides.","authors":"Panasenko, O M; Arnhold, J; Vladimirov YuA; Arnhold, K; Sergienko, V I","year":1997,"date":"1997 Jul","journal":"Free radical research","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Using a chemiluminescent method, the consumption of HOCl/OCl- was investigated during interaction with liposomes prepared from dimyristoylphosphatidylcholine (DMPC) or egg yolk phosphatidylcholine (EYPC). The concentration of HOCl/OCl-decreased with time in the suspension of EYPC that contain unsaturated lipids and did not change in DMPC liposome suspensions. HOCl/OCl- was consumed more rapidly in peroxidized EYPC. The amount of double bonds was lowered by 40% in peroxidized liposomes and decreased by approximately one-third under the action of HOCl/OCl- in both native and peroxidized EYPC samples. Second-order rate constants for the interaction between HOCl and phospholipid double bonds of 0.50 M-1 s-1 were calculated for native EYPC on basis of the consumption of HOCl/OCl- or from the decrease in concentration of double bonds. In peroxidized EYPC this reaction constant was similar as determined following changes in double bonds. It is concluded that the consumption of HOCl/OCl- increased in peroxidized liposomes due to additional reactions with lipid peroxidation products. tert-Butyl hydroperoxide and cumene hydroperoxide, or organic peroxides or epoxides (cis-9,10-epoxystearic acid; cholesterol-5 alpha,6 alpha-epoxide; trans-2,3-epoxy-butane; cis-2,3-epoxy-butane) were incorporated into liposomes and investigated in respect to their ability (1) to increase the consumption of HOCl/OCl- in DMPC liposomes, (2) to generate a non-enhanced chemiluminescence with HOCl/OCl- and (3) to evoke an accumulation of lipid peroxidation products (TBARS) in EYPC liposomes in the absence and presence of NaOCl. None of peroxides or epoxides tested showed any effect on the consumption of HOCl/OCl- or the generation of chemiluminescence. Nor increase of TBARS both in the absence or presence of HOCl/OCl-. In contrast, tert-butyl hydroperoxide and cumene hydroperoxide increased the consumption of HOCl/OCl- in DMPC liposomes and mediated a higher accumulation of TBARS in EYPC liposomes in the presence of HOCl/OCL- over the control. These data suggest that lipid peroxidation in EYPC can be initiated by the reaction of HOCl/OCL- with organic hydroperoxides.","pmid":"9269574","doi":"10.3109/10715769709097832","url":"https://pubmed.ncbi.nlm.nih.gov/9269574/"},{"id":2868,"title":"Structural features associated with reactive metabolite formation in clozapine analogues.","authors":"Uetrecht, J; Zahid, N; Tehim, A; Fu, J M; Rakhit, S","year":1997,"date":"1997 May 2","journal":"Chemico-biological interactions","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Clozapine is associated with a high incidence of agranulocytosis. We had previously found that it is oxidized by granulocytes, or simply HOCl, to a reactive metabolite that irreversibly binds to the cells, and we proposed that this reactive metabolite is responsible for clozapine-induced agranulocytosis. The reactive metabolite appeared to be a nitrenium ion formed by chlorination of the nitrogen bridge between the two aromatic rings. If this is correct, analogs that contain this structural feature should also be oxidized to a reactive intermediate while those not possessing this feature would, at least, not form the same type of reactive intermediate and, therefore, may not induce agranulocytosis. We tested the first part of this hypothesis with three clozapine analogs that do contain a nitrogen bridge and three that do not. Consistent with the hypothesis, the three analogs that do contain the nitrogen bridge formed reactive intermediates that could be trapped with glutathione when oxidized by HOCl, myeloperoxidase or activated neutrophils. In contrast, we found no evidence of a reactive intermediate on oxidation of analogs that contained an oxygen or sulfur bridge rather than a nitrogen bridge. If such reactive metabolites are responsible for drug-induced agranulocytosis, it should be possible to use such a simple screening method to test drugs at an early stage in their development for the potential to induce agranulocytosis.","pmid":"9212779","doi":"10.1016/s0009-2797(97)00017-3","url":"https://pubmed.ncbi.nlm.nih.gov/9212779/"},{"id":2869,"title":"Identification of intermediates in the catalytic cycle of chloroperoxidase.","authors":"Wagenknecht, H A; Woggon, W D","year":1997,"date":"1997 May","journal":"Chemistry & biology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"BACKGROUND: Chloroperoxidase (CPO) is the most versatile of the hemethiolate proteins, catalyzing the chlorination of activated C-H bonds and reactions reminiscent of peroxidase, catalase, and cytochrome P450. Despite 30 years of continuous efforts, no intermediates of the enzyme's catalytic cycle have been identified except for compound I. Thus, in the absence of conclusive evidence it is generally believed that the halogenation of substrates proceeds by means of 'free HOCI' in solution. RESULTS: The pH profile of chloroperoxidase from Caldariomyces fumago revealed a new active-site complex that can be detected only at pH 4.4. According to ultra-violet (UV) spectroscopy, and by comparison with suitable enzyme models, this intermediate is the HOCl adduct of the iron(III) protoporphyrin(IX). Inactivation of chloroperoxidase by diethyl pyrocarbonate, which interrupts the proton shuttle by modification of the distal histidine, led to the formation of the -OCl adduct of the iron complex, which was identified by comparison with a corresponding active site analogue. CONCLUSIONS: The availability of enzyme models of heme-thiolate proteins allowed the identification by UV spectroscopy of both the -OCl adduct and the HOCl adduct of the iron(III) protoporphyrin(IX) of chloroperoxidase. The existence of these previously elusive intermediates suggests that the chlorination catalyzed by CPO, and its corresponding active site analogue, proceeds by Cl+ transfer from the HOCl adduct to the substrate bound in the distal pocket of the enzyme.","pmid":"9195874","doi":"10.1016/s1074-5521(97)90127-7","url":"https://pubmed.ncbi.nlm.nih.gov/9195874/"},{"id":2872,"title":"3-Chlorotyrosine, a specific marker of myeloperoxidase-catalyzed oxidation, is markedly elevated in low density lipoprotein isolated from human atherosclerotic intima.","authors":"Hazen, S L; Heinecke, J W","year":1997,"date":"1997 May 1","journal":"The Journal of clinical investigation","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Oxidation of LDL may be of pivotal importance in atherogenesis, but the mechanisms that promote oxidation in vivo remain poorly understood. We have explored the possibility that one pathway involves myeloperoxidase, a heme protein secreted by phagocytes. Myeloperoxidase is the only human enzyme known to generate hypochlorous acid (HOCl), a potent oxidizing agent, at physiological halide concentrations. LDL exposed to the complete myeloperoxidase-H2O2-Cl- system underwent chlorination of its protein tyrosyl residues. Treatment of LDL with reagent HOCl resulted in 3-chlorotyrosine formation, implicating HOCl as an intermediate in the enzymatic reaction pathway. In contrast, 3-chlorotyrosine was undetectable in LDL oxidized by hydroxyl radical, copper, iron, hemin, glucose, peroxynitrite, horseradish peroxidase, lactoperoxidase, or lipoxygenase. These results indicate that 3-chlorotyrosine is a specific marker for LDL oxidation by myeloperoxidase. To address the role of myeloperoxidase in promoting LDL oxidation in vivo, we used stable isotope dilution gas chromatography-mass spectrometry to quantify 3-chlorotyrosine in human aortic tissue and in LDL isolated from atherosclerotic lesions. The level of 3-chlorotyrosine in atherosclerotic tissue obtained during vascular surgery was sixfold higher than that of normal aortic intima. Moreover, the level of 3-chlorotyrosine was 30-fold higher in LDL isolated from atherosclerotic intima compared with circulating LDL. The detection of 3-chlorotyrosine in human atherosclerotic lesions indicates that halogenation reactions catalyzed by the myeloperoxidase system of phagocytes constitute one pathway for protein oxidation in vivo. These findings raise the possibility that the myeloperoxidase-H2O2-Cl- system plays a critical role in converting LDL into an atherogenic form.","pmid":"9151778","doi":"10.1172/JCI119379","url":"https://pubmed.ncbi.nlm.nih.gov/9151778/"},{"id":2877,"title":"Secretion and inactivation of myeloperoxidase by isolated neutrophils.","authors":"King, C C; Jefferson, M M; Thomas, E L","year":1997,"date":"1997 Mar","journal":"Journal of leukocyte biology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Neutrophils prevent infection by ingesting and killing microorganisms but oxidants and proteases released by neutrophils damage host tissues. Our aim was to identify factors that regulate oxidant production by the enzyme myeloperoxidase (MPO) following secretion of MPO into the medium. Cells stimulated with phorbol myristate acetate (PMA) or opsonized zymosan particles secreted MPO and released superoxide free radicals (.O2-). Dismutation of .O2- produced hydrogen peroxide (H2O2) and MPO catalyzed the oxidation of chloride ion by H2O2 to produce the toxic oxidant hypochlorous acid (HOCl). Adding the enzyme superoxide dismutase (SOD) to increase the rate of conversion of .O2- to H2O2 had pH-dependent effects on HOCl production. From pH 6.0 to 7.4, SOD promoted HOCl production by up to 500% but SOD had no effect at pH 7.6 and inhibited by 40 +/- 10% at pH 7.8. In further experiments at pH 7.0, MPO activity in the cells decreased by 25 +/- 2 and 44 +/- 4% during 1-h incubations with PMA and zymosan. Only 1 +/- 0 and 3 +/- 1% of the total activity was found in the medium, indicating that most of the secreted MPO was inactivated. Loss of activity was not accompanied by proteolytic destruction of the MPO protein, which was measured with anti-MPO antibodies. SOD raised the amount of active MPO in the medium two- to sevenfold, but adding deferoxamine to chelate iron or adding ferric ion had no effect. The ionophore A23187 was as effective as zymosan as a stimulus for MPO secretion but .O2- production by ionophore-stimulated cells was less than 4% of that of PMA- or zymosan-stimulated cells and most of the secreted MPO was found active in the medium. When PMA-stimulated cells were incubated with purified MPO, the added MPO activity was lost from the medium. Binding or proteolysis did not account for loss of activity as indicated by recovery of added radioiodinated MPO from the medium. The visible absorption spectrum of MPO was lost, indicating destruction of the iron-containing prosthetic group. Loss of activity and loss of the MPO spectrum were blocked by SOD but not by deferoxamine or catalase. The results indicate that, in the physiological pH range, inactivation of MPO in the medium suppressed HOCl production. Inactivation required O2- but not HOCl, H2O2, or free iron. Inactivation of secreted MPO may limit MPO-mediated damage to host tissues by stimulated neutrophils.","pmid":"9060452","doi":"10.1002/jlb.61.3.293","url":"https://pubmed.ncbi.nlm.nih.gov/9060452/"},{"id":2879,"title":"Products of the reaction of cholesterol with hypochlorite anion.","authors":"Momynaliev, K T; Osipova, S V; Sadovskaya, V L; Govorun, V M; Sergienko, V I","year":1997,"date":"1997 Feb","journal":"Biochemistry. Biokhimiia","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Products of the reaction of cholesterol with hypochlorite (OCI) in various systems (egg phosphatidylcholine liposomes, low-density lipoproteins, and aqueous colloidal dispersion of cholesterol) were separated and analyzed by TLC, HPLC, and gas chromatography-mass spectrometry. The reactions of hypochlorite with cholesterol result in the same reaction products in all treated systems. Eighteen fractions were isolated from the reaction mixture by normal-phase HPLC in hexane-isopropanol (95:5 v/v); these were then examined by gas chromatography-mass spectrometry. Six products less polar than cholesterol were isolated from the reaction mixture; two of them were identified as 4,6-cholesten-3-one and 4-cholesten-3,6-dione. Among the oxidation products more polar than cholesterol, nine compounds were identified; they are 5,7-cholestadien-3 beta-ol,3,5-cholestadien-7-one, 4-cholesten-3 beta, 6 beta-diol, 5-cholesten-3 beta, 7 beta-diol, cholestan-3 beta, 5 alpha, 6 beta-triol, 5 alpha-cholestan-3 beta-ol-6-one, 5-cholesten-3 beta-ol-7-one, 5 alpha, 6 alpha-epoxycholestan-3 beta-ol, and 5 alpha-cholesten-3,6-dione.","pmid":"9159869","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/9159869/"},{"id":2881,"title":"Activation of the NF-kappaB transcription factor in a T-lymphocytic cell line by hypochlorous acid.","authors":"Schoonbroodt, S; Legrand-Poels, S; Best-Belpomme, M; Piette, J","year":1997,"date":"1997 Feb 1","journal":"The Biochemical journal","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"Reactive oxygen species (ROS) such as hydrogen peroxide serve as second messengers in the induction of the transcription factor NF-kappaB, and hence in the activation and replication of human immunodeficiency virus type 1 (HIV-1) in human cells. During inflammatory reactions, many oxidative species are produced, one of which is hypochlorous acid (HOCl), which is responsible for the microbicidal effects of activated human polymorphonuclear leukocytes. Treatment of a T-lymphocytic cell line with micromolar concentrations of HOCl promoted the appearance of transcription factor NF-kappaB (the heterodimer p50/p65) in the nucleus of the cells, even in the absence of de novo protein synthesis. Western blot analysis of the NF-kappaB inhibitory subunits (IkappaB) demonstrated that both IkappaB-alpha proteolysis and p105 processing were induced by the treatment. NF-kappaB activation was very effective when cells were subjected to hyperthermia before being treated with HOCl. Various antioxidants, such as pyrrolidine dithiocarbamate, p-bromophenacyl-bromide and nordihydroguaiaretic acid could strongly reduce NF-kappaB translocation, demonstrating the importance of oxidative species in the transduction mechanism. Moreover, ACH-2 cells treated with HOCl or H2O2 released tumour necrosis factor-alpha (TNF-alpha) in the supernatants. The importance of TNF-alpha release in NF-kappaB induction by HOCl or H2O2 was demonstrated by the fact that: (1) the nuclear appearance of NF-kappaB was promoted in untreated cells; and (2) synergism between TNF-alpha and HOCl was detected. Collectively, these results suggest that HOCl should be considered as an oxidative species capable of inducing NF-kappaB in a T-lymphocytic cell line through a transduction mechanism involving ROS, and having a long-distance effect through subsequent TNF-alpha release.","pmid":"9032466","doi":"10.1042/bj3210777","url":"https://pubmed.ncbi.nlm.nih.gov/9032466/"},{"id":2883,"title":"Acid adaptation sensitizes Salmonella typhimurium to hypochlorous acid.","authors":"Leyer, G J; Johnson, E A","year":1997,"date":"1997 Feb","journal":"Applied and environmental microbiology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Acid adaptation of Salmonella typhimurium at a pH of 5.0 to 5.8 for one to two cell doublings resulted in marked sensitization of the pathogen to halogen-based sanitizers including chlorine (hypochlorous acid) and iodine. Acid-adapted S. typhimurium was more resistant to an anionic acid sanitizer than was its nonadapted counterpart. A nonselective plating medium of tryptose phosphate agar plus 1% pyruvate was used throughout the study to help recover chemically stressed cells. Mechanisms of HOCl-mediated inactivation of acid-adapted and nonadapted salmonellae were investigated. Hypochlorous acid oxidized a higher percentage of cell surface sulfhydryl groups in acid-adapted cells than in nonadapted cells, and sulfhydryl oxidation was correlated with cell inactivation. HOCl caused severe metabolic disruptions in acid-adapted and nonadapted S. typhimurium, such as respiratory loss and inability to restore the adenylate energy charge from a nutrient-starved state. Sensitization of S. typhimurium to hypochlorous acid by acid adaptation also involved increased permeability of the cell surface because nonadapted cells treated with EDTA became sensitized. The results of this study establish that acid-adapted S. typhimurium cells are highly sensitized to HOCl oxidation and that inactivation by HOCl involves changes in membrane permeability, inability to maintain or restore energy charge, and probably oxidation of essential cellular components. This study provides a basis for improved practical technologies to inactivate Salmonella and implies that acid pretreatment of food plant environments may increase the efficacy of halogen sanitizers.","pmid":"9023924","doi":"10.1128/aem.63.2.461-467.1997","url":"https://pubmed.ncbi.nlm.nih.gov/9023924/"},{"id":2884,"title":"Human neutrophils employ the myeloperoxidase-hydrogen peroxide-chloride system to convert hydroxy-amino acids into glycolaldehyde, 2-hydroxypropanal, and acrolein. A mechanism for the generation of highly reactive alpha-hydroxy and alpha,beta-unsaturated aldehydes by phagocytes at sites of inflammation.","authors":"Anderson, M M; Hazen, S L; Hsu, F F; Heinecke, J W","year":1997,"date":"1997 Feb 1","journal":"The Journal of clinical investigation","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Reactive aldehydes derived from reducing sugars and lipid peroxidation play a critical role in the formation of advanced glycation end (AGE) products and oxidative tissue damage. We have recently proposed another mechanism for aldehyde generation at sites of inflammation that involves myeloperoxidase, a heme enzyme secreted by activated phagocytes. We now demonstrate that human neutrophils employ the myeloperoxidase-H202-chloride system to produce alpha-hydroxy and alpha,beta-unsaturated aldehydes from hydroxy-amino acids in high yield. Identities of the aldehydes were established using mass spectrometry and high performance liquid chromatography. Activated neutrophils converted L-serine to glycolaldehyde, an alpha-hydroxyaldehyde which mediates protein cross-linking and formation of Nepsilon-(carboxymethyl)lysine, an AGE product. L-Threonine was similarly oxidized to 2-hydroxypropanal and its dehydration product, acrolein, an extremely reactive alpha,beta-unsaturated aldehyde which alkylates proteins and nucleic acids. Aldehyde generation required neutrophil activation and a free hydroxy-amino acid; it was inhibited by catalase and heme poisons, implicating H202 and myeloperoxidase in the cellular reaction. Aldehyde production by purified myeloperoxidase required H202 and chloride, and was mimicked by reagent hypochlorous acid (HOCl) in the absence of enzyme, suggesting that the reaction pathway involves a chlorinated intermediate. Collectively, these results indicate that the myeloperoxidase-H202-chloride system of phagocytes converts free hydroxy-amino acids into highly reactive alpha-hydroxy and alpha,beta-unsaturated aldehydes. The generation of glycolaldehyde, 2-hydroxypropanal, and acrolein by activated phagocytes may thus play a role in AGE product formation and tissue damage at sites of inflammation.","pmid":"9022075","doi":"10.1172/JCI119176","url":"https://pubmed.ncbi.nlm.nih.gov/9022075/"},{"id":2886,"title":"Mass spectrometric quantification of 3-chlorotyrosine in human tissues with attomole sensitivity: a sensitive and specific marker for myeloperoxidase-catalyzed chlorination at sites of inflammation.","authors":"Hazen, S L; Crowley, J R; Mueller, D M; Heinecke, J W","year":1997,"date":"1997","journal":"Free radical biology & medicine","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Oxidative modification of proteins has been implicated in a variety of processes ranging from atherosclerosis to aging. Identifying the underlying oxidation pathways has proven difficult, however, due to the lack of specific markers for distinct oxidation pathways. Previous in vitro studies demonstrated that 3-chlorotyrosine is a specific product of myeloperoxidase-catalyzed oxidative damage and that the chlorinated amino acid may thus serve as an index of phagocyte-mediated tissue injury in vivo. Here we describe a highly sensitive and specific analytical method for the quantification of 3-chlorotyrosine content of tissues. The assay combines gas chromatography with stable isotope dilution mass spectrometry, and it detects attomole levels of 3-chlorotyrosine in a single determination. Furthermore, the method is highly reproducible, with inter- and intra-sample coefficients of variance of < 3%. The specificity, sensitivity, and reproducibility of 3-chlorotyrosine determination should make this method useful for exploring the role of myeloperoxidase in catalyzing oxidative reactions in vivo.","pmid":"9378370","doi":"10.1016/s0891-5849(97)00084-1","url":"https://pubmed.ncbi.nlm.nih.gov/9378370/"},{"id":2890,"title":"Metabolism of clozapine by human neutrophils: evidence for a specific oxidation of clozapine by the myeloperoxidase system with inhibition of enzymatic chlorination cycle.","authors":"Frimat, B; Gressier, B; Odou, P; Brunet, C; Dine, T; Luycky, M; Cazin, M; Cazin, J C","year":1997,"date":"1997","journal":"Fundamental & clinical pharmacology","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The use of clozapine, an unique antipsychotic drug, raises the real problem of drug-induced polymorphonuclear neutrophil cytotoxicity. Clozapine prescription has been restricted due to a 1-2% incidence of drug-induced agranulocytosis. The exact mechanism of this adverse effect is not yet known. The myeloperoxidase-hydrogen peroxide system could play a key role in the initiation of agranulocytosis. Therefore, we have investigated the clozapine effects on hydrogen peroxide and hypochlorous acid, evaluated the peroxidase-mediated metabolism of clozapine by mass spectrometry analysis because myeloperoxidase uses hydrogen peroxide and chloride producing hypochlorous acid in its chlorination cycle, and thus could oxidise clozapine in its peroxidation cycle. First, evidence for inhibition of hypochlorous acid production and scavenging of hydrogen peroxide by clozapine were demonstrated in vitro, in different cell-free and cellular systems. Results are consistent with an inhibition of the myeloperoxidase chlorination cycle when clozapine is oxidised in the peroxidation cycle. Secondly, ion-spray mass spectrometry analysis allowed us to confirm clozapine oxidation by the myeloperoxidase system. Actually, clozapine N-oxide with a m/z at 343 was formed. It could be the final step of the metabolisation of clozapine via two successive univalent oxidations mediated by peroxidase. We suggest that generation of a free cation radical, CLZ(o+), was the initial step. CLZ(o+) is a very reactive species and may play an important role in the onset of agranulocytosis either by direct toxicity or via an immunological mechanism. However, this assumption does not exclude the possible role of other metabolic ways involving, in particular, N-desmethylclozapine.","pmid":"9243259","doi":"10.1111/j.1472-8206.1997.tb00195.x","url":"https://pubmed.ncbi.nlm.nih.gov/9243259/"},{"id":2893,"title":"Oxidation of bovine beta-casein by hypochlorite.","authors":"Yang, C Y; Gu, Z W; Yang, H X; Yang, M; Wiseman, W S; Rogers, L K; Welty, S E; Katta, V; Rohde, M F; Smith, C V","year":1997,"date":"1997","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"We recently observed two 2,4-dinitrophenylhydrazine (DNPH)-reactive proteins of 40 and 120 kDa in the bronchoalveolar lavage fluids of rats exposed to >95% O(2) for 48 h. The N-terminal sequences of these proteins were both identical over 16 amino acids with rat beta-casein, which, in addition to its more common association with milk, is produced by cytotoxic T-lymphocytes, and has been found to have proinflammatory properties. Because of the inflammatory response that accompanies hyperoxic lung injury, we investigated the oxidation of bovine beta-casein by HOCl. Following exposure to HOCl at 4 degrees C for 15 min, derivatization with DNPH, washing, and digestion with trypsin, the resultant peptides were separated by reverse-phase HPLC. One peptide isolated from a peak absorbing at 365 nm was identified as AVP(Y*)PQR, corresponding to amino acids 177-183 of bovine beta-casein. Analysis of the peptide by both electrospray and matrix assisted laser desorption ionization (MALDI) mass spectrometry identified a molecular ion MH+ of 1008.5 Da, which represents an increase of 178 Da from the calculated monoisotopic MH+ of the unmodified peptide of 830.45 Da. Daughter ion spectra of the doubly charged parent ion of the peptide further support the oxidation of the tyrosine to the quinone methide, with subsequent conversion to the corresponding hydrazone with DNPH. A second pair of products were identified as arising from oxidation of Y(193) within the tryptic peptide constituted by amino acids 184-202, and the corresponding chymotryptic cleavage side product, 191-202. Exposure of beta-casein to increasing amounts of HOCl revealed that M and Y residues were the most susceptible, although bovine beta-casein contains no C, and a single W, which would not be detected by our methods. The approach described in the present report can be used to evaluate the contributions of distinct mechanisms of oxidation in other experimental or pathological models.","pmid":"9098098","doi":"10.1016/s0891-5849(96)00551-5","url":"https://pubmed.ncbi.nlm.nih.gov/9098098/"},{"id":2896,"title":"Aminobenzoic acid compounds as HOCl traps for activated neutrophils.","authors":"She, Z W; Mays, D C; Sagone, A L Jr; Davis, W B","year":1997,"date":"1997","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"This study was designed to develop traps for hypochlorous acid (HOCl) which could be used to detect HOCl in the microenvironment of activated neutrophils. Reagent HOCl was found to react with para-aminobenzoic acid (PABA) in aqueous solution to produce a predominant metabolite detectable by high performance liquid chromatography (HPLC). Mass spectroscopy and nuclear magnetic resonance identified this metabolite as the ring addition product 3-chloro PABA. The related compound para-aminosalicylic acid (PAS) was also metabolized by HOCl to 3-chloro PAS. The formation of the 3-chloro metabolite was specific for reactions involving HOCl, since several other oxidants in chloride buffer failed to produce the metabolite. Human blood neutrophils activated by phorbol myristate acetate or zymosan in the presence of PABA (or PAS) used their HOCl to produce large amounts of the 3-chloro metabolite. The formation of 3-chloro PABA was inhibited by azide, catalase, and taurine, which is consistent with the production of the metabolite by the neutrophil myeloperoxidase (MPO) pathway. The reaction of HOCl with PABA and PAS was relatively slow as shown by competitive reactions with endogenous antioxidants like taurine, methionine, and glutathione. This was confirmed in reactions involving PABA/PAS and reagent HOCl or HOCl generated by the MPO enzyme system. In these in vitro systems, glutathione and serum completely inhibited the formation of the 3-chloro metabolite. In contrast, activated neutrophils metabolized PABA/PAS to the 3-chloro metabolite even in the presence of 1% serum. These findings demonstrate that PABA and PAS are specific trapping agents for HOCl produced by neutrophils in complex biological conditions.","pmid":"9034238","doi":"10.1016/s0891-5849(96)00486-8","url":"https://pubmed.ncbi.nlm.nih.gov/9034238/"},{"id":2906,"title":"Efficacy of teat dips containing a hypochlorous acid germicide against experimental challenge with Staphylococcus aureus and Streptococcus agalactiae.","authors":"Boddie, R L; Nickerson, S C","year":1996,"date":"1996 Sep","journal":"Journal of dairy science","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Two teat dip formulations containing sodium dichloroisocyanurate, which released hypochlorous acid (2800 ppm) as the active ingredient, were tested for efficacy against new Staphylococcus aureus and Streptococcus agalactiae IMI using an experimental challenge model. Product 1 reduced the number of new Staph. aureus IMI by 73.6% and reduced the number of new Strep. agalactiae IMI by 65.1%. Product 2 reduced the number of new Staph. aureus IMI by 69.0% and reduced the number of new Strep. agalactiae IMI by 63.5%. No adverse effects on teat skin condition were observed over the course of the studies.","pmid":"8899537","doi":"10.3168/jds.S0022-0302(96)76533-5","url":"https://pubmed.ncbi.nlm.nih.gov/8899537/"},{"id":2908,"title":"Formation of nitrating and chlorinating species by reaction of nitrite with hypochlorous acid. A novel mechanism for nitric oxide-mediated protein modification.","authors":"Eiserich, J P; Cross, C E; Jones, A D; Halliwell, B; van der Vliet, A","year":1996,"date":"1996 Aug 9","journal":"The Journal of biological chemistry","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"Detection of 3-nitrotyrosine has served as an in vivo marker for the production of the cytotoxic species peroxynitrite (ONOO-). We show here that reaction of nitrite (NO2-), the autoxidation product of nitric oxide (.NO), with hypochlorous acid (HOCl) forms reactive intermediate species that are also capable of nitrating phenolic substrates such as tyrosine and 4-hydroxyphenylacetic acid, with maximum yields obtained at physiological pH. Monitoring the reaction of NO2- with HOCl by continuous flow photodiode array spectrophotometry indicates the formation of a transient species with spectral characteristics similar to those of nitryl chloride (Cl-NO2). Reaction of synthetic Cl-NO2 with N-acetyl-L-tyrosine results in the formation of 3-chlorotyrosine and 3-nitrotyrosine in ratios that are similar to those obtained by the NO2-/HOCl reaction (4:1). Tyrosine residues in bovine serum albumin are also nitrated and chlorinated by NO2-/HOCl and synthetic Cl-NO2. The reaction of N-acetyl-L-tyrosine with NO2-/HOCl or authentic Cl-NO2 also produces dityrosine, suggesting that free radical intermediates are involved in the reaction mechanism. Our data indicate that while chlorination reactions of Cl-NO2 are mediated by direct electrophilic addition to the aromatic ring, a free radical mechanism appears to be operative in nitrations mediated by NO2-/HOCl or Cl-NO2, probably involving the combination of nitrogen dioxide (.NO2) and tyrosyl radical. We propose that NO2- reacts with HOCl by Cl+ transfer to form both cis- and trans-chlorine nitrite (Cl-ONO) and Cl-NO2 as intermediates that modify tyrosine by either direct reaction or after decomposition to reactive free and solvent-caged Cl. and .NO2 as reactive species. Formation of Cl-NO2 and/or Cl-ONO in vivo may represent previously unrecognized mediators of inflammation-mediated protein modification and tissue injury, and offers an additional mechanism of tyrosine nitration independent of ONOO-.","pmid":"8702599","doi":"10.1074/jbc.271.32.19199","url":"https://pubmed.ncbi.nlm.nih.gov/8702599/"},{"id":2909,"title":"Effects of extracts from Populus tremula L., solidago virgaurea L. and Fraxinus excelsior L. on various myeloperoxidase systems.","authors":"von Kruedener, S; Schneider, W; Elstner, E F","year":1996,"date":"1996 Aug","journal":"Arzneimittel-Forschung","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Extracts from Populus tremula, Solidago virgaurea and Fraxinus excelsior are used as anti-inflammatory drugs. The effects of these extracts on myeloperoxidase (MPO), an enzyme liberated by activated granulocytes and known to produce the destructive agent hypochloric acid, were investigated. Populus and Fraxinus inhibited this enzyme, Solidago was without effect. These results were obtained concordantly with four different MPO-assays (H2O2/MPO; X/XOD/MPO; activated PMN; and elastase/alpha 1-PI-MPO). Fractionation of Populus and Fraxinus extracts showed that this inhibition is due to several different compounds. Well known or wide spread substances as e.g. rutin, salicylic acid, chlorogenic acid etc. had no or only little effect on the enzyme.","pmid":"9125284","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/9125284/"},{"id":2911,"title":"Hypochlorous acid interactions with thiols, nucleotides, DNA, and other biological substrates.","authors":"Prütz, W A","year":1996,"date":"1996 Aug 1","journal":"Archives of biochemistry and biophysics","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"HOC1-induced one-electron oxidation of Fe(CN)(6)4- was used as a reference reaction to investigate the stoichiometry of interaction of HOCl with a variety of biological substrates. GSH and GSSG were both found capable of reacting with four and 2-mercaptoethanol with three HOCl molecules. Stopped-flow investigations, with HOCl in excess, indicate that very fast primary reactions of HOCl with GSH and DTPA are followed by slower secondary reactions. In the case of GSH we propose that one HOCl reacts at the terminal alpha-amino-group and three HOCl react at the -SH group to generate the sulfonylchloride GSO2Cl. This assignment is supported by the finding that reaction of HOCl (in excess) with 2-mercaptonaphthalene generates the absorption spectrum of authentic naphthalene-2-sulfonylchloride. NADH reacts with at least two HOCl molecules. A very fast primary reaction of HOCl was followed by a slower secondary reaction at HOCl/NADH > 2, but neither the primary nor the secondary reaction led to NAD+. Stopped-flow investigations of reactions of HOCl with nucleotides indicate that HOCl reacts slowly with the amino-groups of AMP, CMP, and GMP but very fast with the heterocyclic NH-groups of GMP, inosine, and TMP. AMP and CMP promote, but GMP, inosine, and TMP retard HOCl-induced oxidation of Fe(CN)(6)4-. At present we have no convincing evidence, however, that products of interaction of HOCl with nucleotides are capable of one-electron oxidation of Fe(CN)6(-4), with generation of free radical intermediates. HOCl causes slow but very efficient denaturation of native DNA, in our opinion not by oxidative fragmentation, but due to chlorination of amino- and heterocyclic NH-groups of the DNA-bases, which leads to dissociation of the double strand by the loss of hydrogen bonding. HOCl-induced oxidation of Fe(CN)(6)4- is promoted very efficiently by catalytic amounts of Cu2+. Catalysis is explainable by formation of a CuIFeIII(CN)(6)2- complex, with CuI acting as electron donor in a propagating Fenton-like reaction, CuIFeIII(CN)(6)2- +HOCl-->Cu2+ + Fe(CN)(6)3- + Cl- + OH, the rate constant of which was estimated as k = 1.8 x 10(5) M-1 s-1. HOCl is inactivated by Tris, but Hepes promotes HOCl-induced oxidation of Fe(CN)(6)4- very efficiently; this is a warning against application of such buffers in investigations of HOCl- or myeloperoxidase-induced reactions. Anthranilic acid was found to interact with four HOCl molecules to yield highly reactive (unidentified) one-electron oxidants.","pmid":"8806715","doi":"10.1006/abbi.1996.0322","url":"https://pubmed.ncbi.nlm.nih.gov/8806715/"},{"id":2912,"title":"Chlorination of cholesterol in cell membranes by hypochlorous acid.","authors":"Carr, A C; van den Berg, J J; Winterbourn, C C","year":1996,"date":"1996 Aug 1","journal":"Archives of biochemistry and biophysics","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Neutrophils and monocytes produce the highly cytotoxic hypochlorous acid (HOCl) via the myeloperoxidase (MPO)-catalyzed reaction of H2O2 with Cl-. We have investigated the reaction of reagent and MPO-derived HOCl with cholesterol in a purified liposome system, as well as progressively more complex biological systems. The products were identified by thin-layer chromatography (TLC) and characterized by mass spectrometry (MS). TLC of the HOCl-treated samples gave four major cholesterol products with color development typical of oxysterols. Two of the products coeluted with authentic alpha- and beta-chlorohydrin standards. As was the case with the standards, they were readily converted into their respective epoxides during analysis by MS. Gas chromatography-mass spectrometry analysis of the other major product (band 3) gave peaks consistent with epoxides as well as a lateeluting peak with a distinct mass spectrum. Electrospray MS of this product confirmed its identity as a chlorohydrin based on the presence of the predicted molecular ion and 3:1 Cl isotope ratios. Lipids extracted from red cells and isolated red cell membranes were exposed to HOCl and gave identical products to the purified cholesterol liposome system as determined by TLC and MS. Higher concentrations of HOCl were required due to competition by other unsaturated lipids and protein molecules. When intact red cells, neutrophils, and MCF7 mammary carcinoma cells were exposed to HOCl, cholesterol chlorohydrins were formed, as detected by TLC. The formation of cholesterol chlorohydrins could be potentially disruptive to cell membranes and result in cell lysis and death. They could also be potential biomarkers for oxidative damage associated with neutrophil/monocyte activation.","pmid":"8806710","doi":"10.1006/abbi.1996.0317","url":"https://pubmed.ncbi.nlm.nih.gov/8806710/"},{"id":2914,"title":"Virulence properties of Pseudomonas aeruginosa lacking the extreme-stress sigma factor AlgU (sigmaE).","authors":"Yu, H; Boucher, J C; Hibler, N S; Deretic, V","year":1996,"date":"1996 Jul","journal":"Infection and immunity","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"A discerning feature of Pseudomonas aeruginosa strains causing chronic endobronchial infections in cystic fibrosis is their conversion into the mucoid, exopolysaccharide alginate-overproducing phenotype. This morphologically prominent change is caused by mutations which upregulate AlgU (sigma(E)), a novel extreme-stress sigma factor with functional equivalents in gram-negative organisms. In this work, we investigated the role of algU in P. aeruginosa sensitivity to reactive oxygen intermediates, killing by phagocytic cells, and systemic virulence of this bacterium. Inactivation of algU in P. aeruginosa PA01 increased its susceptibility to killing by chemically or enzymatically generated halogenated reactive oxygen intermediates and reduced its survival in bactericidal assays with J774 murine macrophages and human neutrophils. Surprisingly, inactivation of algU caused increased systemic virulence of P. aeruginosa in mouse models of acute infection. The increased lethality of the algU-deficient strain was also observed in the endotoxin-resistant C3H/HeJ mice. Only minor differences between algU+ and algU mutant cells in their sensitivity to human serum were observed, and no differences in their lipopolysaccharide profiles were detected. Intriguingly, while inactivation of algU downregulated five polypeptides it also upregulated the expression of seven polypeptides as determined by two-dimensional gel analyses, suggesting that algU plays both a positive and a negative role in gene expression in P. aeruginosa. While the observation that algU inactivation increases systemic virulence in P. aeruginosa requires further explanation, this phenomenon contrasts with the apparent selection for strains with upregulated AlgU during colonization of the cystic fibrosis lung and suggests opposing roles for this system in chronic and acute infections.","pmid":"8698507","doi":"10.1128/iai.64.7.2774-2781.1996","url":"https://pubmed.ncbi.nlm.nih.gov/8698507/"},{"id":2917,"title":"NMR studies on human, pathologically changed synovial fluids: role of hypochlorous acid.","authors":"Schiller, J; Arnhold, J; Sonntag, K; Arnold, K","year":1996,"date":"1996 Jun","journal":"Magnetic resonance in medicine","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Recently, it has been reported that hypochlorous acid (HOCl), a special product of neutrophil myeloperoxidase, degrades N-acetyl groups of N-acetylglucosamine, chondroitin sulfate, hyaluronic acid, and minced articular cartilage via a transient product to acetate. This work concerns 1H NMR investigations of synovial fluids of patients with rheumatoid arthritis (RA). Synovial fluids of patients with severe forms of this disease are characterized by enhanced 1H NMR signals for N-acetyl groups (approximately 2.0 ppm) and acetate (1.90 ppm) and the appearance of a broad but less intense signal at 2.35 ppm. It is likely that this signal corresponds to the transient, chlorinated product of degradation of N-acetyl groups by hypochlorous acid. Moreover, 1H NMR signal intensities of N-acetyl groups and acetate strongly correlate with the myeloperoxidase activities in synovial fluids from patients with rheumatoid arthritis. These results have been confirmed by treatment of native sheep synovial fluid with sodium hypochlorite, resulting in the formation of the same resonances as observed in pathologically changed synovial fluids from humans. Thus, it is concluded that HOCl plays an important role for the cartilage degradation during rheumatoid arthritis.","pmid":"8744012","doi":"10.1002/mrm.1910350610","url":"https://pubmed.ncbi.nlm.nih.gov/8744012/"},{"id":2919,"title":"Escherichia coli exhibits negative chemotaxis in gradients of hydrogen peroxide, hypochlorite, and N-chlorotaurine: products of the respiratory burst of phagocytic cells.","authors":"Benov, L; Fridovich, I","year":1996,"date":"1996 May 14","journal":"Proceedings of the National Academy of Sciences of the United States of America","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Escherichia coli can respond to gradients of specific compounds, moving up gradients of attractants and down gradients of repellents. Stimulated phagocytic leukocytes produce H2O2, OCl-, and N-chlorotaurine in a response termed the respiratory burst. E. coli is actively repelled by these compounds. Catalase in the suspending medium eliminated the effect of H2O2. Repulsion by H2O2 could be demonstrated with 1 microM H2O2, which is far below the level that caused overt toxicity. Strains with defects in the biosynthesis of glutathione or lacking hydroperoxidases I and II retained this response to H2O2, and 2.0 mM CN- did not interfere with it. Mutants with defects in any one of the four known methyl-accepting chemotaxis proteins also retained the ability to respond to H2O2, but a \"gutted\" mutant that was deleted for all four methyl-accepting chemotaxis proteins, as well as for CheA, CheW, CheR, CheB, CheY, and CheZ, did not respond to H2O2. Hypochlorite and N-chlorotaurine were also strongly repellent. Chemotaxis down gradients of H2O2, OCl-, and N-chlorotaurine may contribute to the survival of commensal or pathogenic microorganisms.","pmid":"8643518","doi":"10.1073/pnas.93.10.4999","url":"https://pubmed.ncbi.nlm.nih.gov/8643518/"},{"id":2922,"title":"Efficacy of hypochlorous acid scavengers in the prevention of protein carbonyl formation.","authors":"Yan, L J; Traber, M G; Kobuchi, H; Matsugo, S; Tritschler, H J; Packer, L","year":1996,"date":"1996 Mar 15","journal":"Archives of biochemistry and biophysics","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"We observed that protein (bovine serum albumin) carbonyl content increases upon hypochlorite oxidation, and this increase is inhibited in a concentration-dependent manner in the presence of hypochlorite scavengers. Based on this observation, we tested whether some known hypochlorite scavengers (lipoic acid, cysteine, and glutathione) and some other antioxidants (uric acid, ascorbic acid, alpha-tocopherol, and probucol) could prevent protein carbonyl formation. N-acetylcysteine, dihydrolipoic acid, cysteine, and glutathione (reduced form, GSH), which otherwise could not be tested in a previously reported 5-thio-2-nitrobenzoic acid test system, were successfully evaluated in our assay. The hypochlorite scavenging capacity of different compounds, compared by determining the IC50 (concentration which produces 50% inhibition), showed that the compounds tested have the following potency: dihydrolipoic acid > GSH, N-acetylcysteine > cysteine > S-methyl glutathione > lipoic acid, ascorbic acid > cystine, GSSG, and uric acid. No scavenging ability was observed for either alpha-tocopherol or probucol.","pmid":"8619623","doi":"10.1006/abbi.1996.0130","url":"https://pubmed.ncbi.nlm.nih.gov/8619623/"},{"id":2925,"title":"Peroxynitrite formed by simultaneous generation of nitric oxide and superoxide selectively inhibits bovine aortic prostacyclin synthase.","authors":"Zou, M H; Ullrich, V","year":1996,"date":"1996 Mar 11","journal":"FEBS letters","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The effect of various oxidants on bovine aortic prostacyclin synthase was tested with 14C-labelled prostaglandin endoperoxide as substrate. No sensitivity against hydrogen peroxide, superoxide or hydroxyl radicals was observed but hypochlorite inhibited with an IC50 value of 7 microM. Among the reactive nitrogen species nitric oxide and nitrogen dioxide radicals were ineffective, but peroxynitrite irreversibly blocked prostacyclin biosynthesis with an IC50 value of 50 nM. Peroxynitrite acted within seconds whereas hypochlorite required up to 30 min for completion. Simultaneous generation of nitric oxide and superoxide also caused inhibition which suggested that under pathological conditions like ischemia-reperfusion not only the vasodilatory effects of nitric oxide but also those of prostacyclin could be eliminated.","pmid":"8612727","doi":"10.1016/0014-5793(96)00160-3","url":"https://pubmed.ncbi.nlm.nih.gov/8612727/"},{"id":2929,"title":"Neutrophils convert tyrosyl residues in albumin to chlorotyrosine.","authors":"Kettle, A J","year":1996,"date":"1996 Jan 22","journal":"FEBS letters","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid chlorinates tyrosyl residues in small peptides to produce chlorotyrosine. Detection of chlorotyrosine has the potential to unequivocally identify the contribution hypochlorous acid makes to inflammation. I have developed a selective and sensitive HPLC assay for measuring chlorotyrosine. When albumin was exposed to reagent hypochlorous acid, or that produced by myeloperoxidase and stimulated neutrophils, tyrosyl residues in the protein were converted to chlorotyrosine. About 2% of the hypochlorous acid generated by neutrophils was accounted for by the formation of chlorotyrosine. These results demonstrate that chlorotyrosine will be a useful marker for establishing a role for hypochlorous acid in host defence and inflammation.","pmid":"8566218","doi":"10.1016/0014-5793(95)01494-2","url":"https://pubmed.ncbi.nlm.nih.gov/8566218/"},{"id":2930,"title":"Changes in receptor function by oxidative stress in guinea pig tracheal smooth muscle.","authors":"van Hoof, I H; van Bree, L; Bast, A","year":1996,"date":"1996","journal":"Central European journal of public health","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"We studied the effects of hydrogen peroxide, hypochlorous acid and ozone on muscarinic and beta-adrenergic receptor responses in guinea pig tracheal tissue. Pretreatment of the tracheal strips with hydrogen peroxide (up to 10 mM) did not affect the muscarinic or beta-adrenergic receptor responses after stimulation with methacholine or (-)-isoprenaline respectively. In contrast to hydrogen peroxide, hypochlorous acid (1 mM and 10 mM) decreased the maximal contraction and the pD2-value after stimulation with the muscarinic agonist methacholine. Comparable effects were observed after stimulation with the beta-adrenoceptor agonist (-)-isoprenaline but the beta-adrenoceptor response seemed to be more susceptible to hypochlorous acid treatment than the muscarinic response. In other words, hypochlorous acid changes the balance between muscarinic and beta-adrenergic receptor responses of guinea pig tracheal strips in favour of the muscarinic receptor responses. In vivo exposure of the guinea pigs to 3 ppm ozone for two hours resulted in a hyperreactivity (increase in maximal contraction) after stimulation of the muscarinic receptor with methacholine. No effects were observed in the pD2-value. The beta-adrenergic receptor response was also affected after ozone exposure. No effects were seen in the maximal (-)-isoprenaline induced relaxation but there was an increase (hypersensitivity) in the pD2-value. Our data suggest that oxidative stress modulates receptor responses. Moreover, the type of oxidant seems to differentially affect various receptor responses. This may be of importance to further understand the influence of an oxidative effect (either directly via ozone or through inflammation) in lung tissue.","pmid":"9167047","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/9167047/"},{"id":2931,"title":"Oxidative modification of ovalbumin.","authors":"Olszowski, S; Olszowska, E; Stelmaszyńska, T; Krawczyk, A; Marcinkiewicz, J; Baczek, N","year":1996,"date":"1996","journal":"Acta biochimica Polonica","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Stimulated neutrophils (PMNL) are a source of the active oxygen species: O2, H2O2 and HOCl/OCl- which in turn can act on proteins yielding a variety of mixed oxidation products. A system is proposed in which a model protein-ovalbumin (OVA) first undergoes chlorination by HOCl/OCl- and next is oxidised by H2O2. The modification of functional groups (-NH2, -SH, -S-S-, > C = O, Tyr and Trp) in OVA was monitored as well as their accessibility to promote aggregation. Chlorination resulted in additional inter- or intra -S-S- bond formation followed by a decrease in the total sulfhydryl group content. Amino groups were oxidised to carbonyl moieties with a concomitant acidic shift of pI. Formation of chlorotyrosine at the chlorination step was confirmed and its further H2O2-mediated transformation to bityrosine was demonstrated. It has also been confirmed that tryptophan, and not tyrosine, is the first target for chlorination. SDS/PAGE and HPLC profiles revealed that HOCl/OCl- chlorination promotes formation of aggregates stabilised by non covalent bonds. In conclusion, we suggest that a dramatic change in the OVA molecule structure begins when the molar excess of HOCl/OCl- is about 2 per one reactive group in OVA.","pmid":"9104502","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/9104502/"},{"id":2934,"title":"Evaluation of the antioxidant activity of melatonin in vitro.","authors":"Marshall, K A; Reiter, R J; Poeggeler, B; Aruoma, O I; Halliwell, B","year":1996,"date":"1996","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Melatonin is being increasingly promoted as a treatment for \"jet lag\" and insomnia and has been suggested to act as an antioxidant in vivo. The antioxidant and potential pro-oxidant activities of melatonin were investigated in vitro. Melatonin was able to scavenge hypochlorous acid (HOCl) at a rate sufficient to protect catalase against inactivation by this molecule. Melatonin could also prevent the oxidation of 5-thio-2-nitrobenzoic acid by HOCl. Melatonin decreased the peroxidation of ox-brain phospholipids with a calculated IC50 of (210 +/- 2.3) microM. In contrast, serotonin which also scavenged HOCl, was much more effective in decreasing phospholipid peroxidation (IC50 15 +/- 5 microM). Both compounds reacted with trichloromethylperoxyl radical (CCl3O2) with rate constants of (2.7 +/- 0.2) x 10(8) and (1.2 +/- 0.1) x 10(8)M-1 s- respectively. Melatonin did not scavenge superoxide radical and weakly protected DNA against damage by the ferric bleomycin system. By contrast serotonin was weakly pro-oxidant in the ferric-bleomycin system and strongly pro-oxidant in the Fe(3+)-EDTA/H2O-deoxyribose system. Solubility restrictions precluded examination of melatonin in this system. Our data show that melatonin exerts only limited direct antioxidant activities.","pmid":"8855441","doi":"10.1016/0891-5849(96)00046-9","url":"https://pubmed.ncbi.nlm.nih.gov/8855441/"},{"id":2936,"title":"Hypochlorous acid/N-chloramines are naturally produced DNA repair inhibitors.","authors":"Pero, R W; Sheng, Y; Olsson, A; Bryngelsson, C; Lund-Pero, M","year":1996,"date":"1996 Jan","journal":"Carcinogenesis","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Human mononuclear leukocytes (HML) respond to oxidative DNA damage by activation of ADP ribosylation and initiation of DNA repair synthesis (i.e. unscheduled DNA synthesis, UDS), whereas neutrophils do not. When neutrophils are added to HML cultures in ratios up to 4:1 ADP ribosylation becomes inhibited to approximately 50-60%. The ability of neutrophils to inhibit HML ADP ribosylation was shown to be dependent on H2O2, chloride ions and myeloperoxidase, which in turn are factors known to govern HOCl and N-chloramine production by phagocytic cells. HOCl and a model N-chloramine, chloramine T, were shown to give a dose-dependent inhibition of DNA repair using four independent estimates, namely ADP ribosylation, UDS and the repair of DNA strand breaks estimated by nucleoid sedimentation and alkaline elution profiles. All the DNA repair measurements used on HML were inhibited approximately 70-80% by 100 microM doses of HOCl or chloramine T, which was considered a biologically relevant dose because: (i) viable neutrophils equal in concentration to those found in blood could easily produce 100 microM levels in short-term culture; (ii) 100 microM doses of these agents were not acutely cytotoxic judged by trypan blue stained cells after 30-60 min exposure and under the conditions used for assay, but yet they abolished 86-95% of the growth response of HML to phytohemagglutinin.","pmid":"8565122","doi":"10.1093/carcin/17.1.13","url":"https://pubmed.ncbi.nlm.nih.gov/8565122/"},{"id":2938,"title":"Chlorogenic acid as a natural scavenger for hypochlorous acid.","authors":"Kono, Y; Shibata, H; Kodama, Y; Ueda, A; Sawa, Y","year":1995,"date":"1995 Dec 26","journal":"Biochemical and biophysical research communications","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The effect of chlorogenic acid (CGA) on the killing of Escherichia coli by hypochlorous acid (HOCI) was examined. CGA prevented E. coli from bactericidal action of HOCI in a concentration-dependent manner. HOCI reacted rapidly with CGA. By comparison with the one- and two-electron oxidation products produced by peroxidase and phenolase reactions, respectively, the main product was identified as o-quinone of CGA via the formation of o-semiquinone of CGA as an intermediate The quinone form of CGA reacted further with HOCI to yield unstable product(s).","pmid":"8554623","doi":"10.1006/bbrc.1995.2865","url":"https://pubmed.ncbi.nlm.nih.gov/8554623/"},{"id":2942,"title":"The action of hypochlorous acid on phosphatidylcholine liposomes in dependence on the content of double bonds. Stoichiometry and NMR analysis.","authors":"Arnhold, J; Panasenko, O M; Schiller, J; Vladimirov YuA; Arnold, K","year":1995,"date":"1995 Oct 22","journal":"Chemistry and physics of lipids","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Kinetics of the consumption of hypochlorous acid in its reaction with double bonds of unsaturated phospholipids and fatty acids were measured using luminol chemiluminescence. Stoichiometry ratios between the consumption of HOCl/OCl- and the loss of double bonds vary from 2:1 to 1:1. Highest values were found in DMPC liposomes containing 5 mol% oleic acid or OPPC. With increasing content of double bonds or higher numbers of double bonds in a fatty acid acyl chain due to incorporated unsaturated fatty acids or phospholipids in DMPC liposomes the stoichiometry ratio falls continuously to 1:1. A ratio of about 1:1 was observed in multilamellar and unilamellar liposomes composed of egg yolk phosphatidylcholine. Products of the reaction of oleic acid with hypochlorous acid were analyses by 1H-NMR spectroscopy. Chlorohydrins were formed in both DMPC liposomes containing 5 or 40 mol% oleic acid.","pmid":"8521532","doi":"10.1016/0009-3084(95)02484-z","url":"https://pubmed.ncbi.nlm.nih.gov/8521532/"},{"id":2944,"title":"NMR studies of the action of hypochlorous acid on native pig articular cartilage.","authors":"Schiller, J; Arnhold, J; Arnold, K","year":1995,"date":"1995 Oct 15","journal":"European journal of biochemistry","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The action of sodium hypochlorite on pig articular cartilage was studied by 1H-NMR spectroscopy to model some aspects of degradation processes of cartilage during rheumatoid arthritis. Two effects of NaOCl on cartilage polysaccharides have been observed. Hypochlorous acid causes an enhanced release of oligomeric polysaccharides from cartilage. The second effect concerns the degradation of N-acetyl side chains of carbohydrates to acetate via a chlorinated transient product. Signal intensities for N-acetyl groups (approximately 2.0 ppm) increase during the first 2 h of incubation of cartilage with NaOCl. Then they decrease again. However, acetate (1.90 ppm) as the final product of degradation of N-acetyl side chains increases continuously over the period of incubation with NaOCl. In addition to polysaccharides, effects of NaOCl were only observed in cartilage samples on amino acids like alanine. The alanine resonance disappeared already at NaOCl concentrations where only small effects on cartilage polysaccharides have been observed.","pmid":"7588815","doi":"10.1111/j.1432-1033.1995.672_2.x","url":"https://pubmed.ncbi.nlm.nih.gov/7588815/"},{"id":2945,"title":"[The effect of hydrogen peroxide and hypochlorite on brain Na,K-ATPase activity].","authors":"Boldyrev, A A; Bulygina, E R; Volynskaia, E A; Kurella, E G; Tiulina, O V","year":1995,"date":"1995 Oct","journal":"Biokhimiia (Moscow, Russia)","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Brain Na,K-ATPase is subjected to direct modifying influence of the hypochlorite anion and hydrogen peroxide resulting in irreversible inactivation of the enzyme. The K0.5 values for these compounds are 20-40 microM and 1 mM, respectively. The inhibiting effect of hydrogen peroxide is suppressed by desferrioxamine (by 20-30%) which indicates that the H2O2-induced inhibition is partly due to the generation of the hydroxyl radical. Carnosine, homocarnosine and the hydrophobic antioxidants, alpha-tocopherol and ionol, protect the enzyme from H2O2: their effective concentrations are to 10 mM (carnosine), 5 microM (alpha-tocopherol), and 0.5 microM (ionol). The data obtained suggest that inhibition of Na,K-ATPase by the antioxidants is caused by their direct action on the protein molecule, while the protective effect of natural hydrophilic antioxidants are due to the quenching of the hydroxyl radical.","pmid":"8555364","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/8555364/"},{"id":2947,"title":"Action of hypochlorous acid on polymeric components of cartilage. Use of 13C NMR spectroscopy.","authors":"Schiller, J; Arnhold, J; Arnold, K","year":1995,"date":"1995 Sep-Oct","journal":"Zeitschrift fur Naturforschung. C, Journal of biosciences","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"It is a well known fact that neutrophil-derived hypochlorous acid plays an important role in cartilage destruction during rheumatoid arthritis. It has been shown by 1H NMR spectroscopy in a previous paper (Schiller et al. (1994), Biol. Chem. Hoppe-Seyler 375, 167-172) that sodium hypochlorite affects primarily the N-acetyl side chains of polymeric carbohydrates of cartilage like chondroitinsulphate and hyaluronic acid. An instable intermediate, likely to be a chloramine, is involved in these processes. The present paper deals with the application of carbon NMR spectroscopy for the study of these degradation processes, because carbon NMR gives the opportunity to detect changes on the single sugar ring carbons. Although it was not possible to prove the involvement of an intermediate, because of its fast hydrolysis, we were able to show that the reaction between sodium hypochlorite and N-acetylglucosamine affects mainly the side chain, accompanied by the formation of acetate. The application of a large excess of sodium hypochlorite leads to a breakdown of the carbohydrate ring under the formation of formiate.","pmid":"8579689","doi":"10.1515/znc-1995-9-1020","url":"https://pubmed.ncbi.nlm.nih.gov/8579689/"},{"id":2948,"title":"[Interaction of hypochlorite with hydroperoxides and other oxidation products of phosphatidylcholine liposomes].","authors":"Panasenko, O M; Arnhold, J; Vladimirov, Iu A; Sergienko, V I","year":1995,"date":"1995 Sep","journal":"Biokhimiia (Moscow, Russia)","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The chemiluminescence in the presence of luminol has been used to measure the amount of hypochlorite and its reduction during the interaction with oxidized and non-oxidized liposomes from egg yolk phosphatidylcholine as well as with organic peroxides (tert-butylhydroperoxide, cumene hydroperoxide, di-tert-butylperoxide, tert-butylperbenzoate, di-benzoylperoxide), and epoxides (cis- and trans-2,3-epoxy-butane, cholesterol-5 alpha,6 alpha-epoxide, and cis-9,10-epoxystearic acid). Since hypochlorite did not react with the saturated phospholipid, dimyristoylphosphatidylcholine (DMPC), and the reduction of double bonds in egg yolk phosphatidylcholine liposomes occurred at the same rate in both oxidized and non-oxidized liposomes, it may be suggested that hypochlorite interacted precisely with LPO products. None of the epoxides tested in this study, similar to di-tert-butylperoxide, tert-butylperbenzoate, di-benzoylperoxide, incorporated into liposomes reacted with hypochlorite. In contrast, tert-butylhydroperoxide and cumene hydroperoxide effectively reacted with it. The data obtained suggest that epoxides, dialkyl-, diacyl-, and alkyl-acyl-peroxides are not involved in hypochlorite-induced LPO. At the same time, organic hydroperoxides commonly present in certain amounts in the biomembrane lipid phase in vivo may play a role lf an intermediate; its interaction with HOCl/OCl- gives rise to free radical formation followed by accumulation of LPO products.","pmid":"8562650","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/8562650/"},{"id":2952,"title":"Activation of human neutrophils by surface-associated IgA is associated with the release of activated collagenase.","authors":"Blackburn, W D Jr; Minghetti, P P; Schrohenloher, R E; Chatham, W W","year":1995,"date":"1995 Sep","journal":"Clinical immunology and immunopathology","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Neutrophils contain on their surface a receptor for the Fc portion of IgA. Cross-linking of this receptor in the fluid phase induces superoxide production and release of granule constituents, but the response to surface associated IgA has not been previously studied. Neutrophils incubated with surface-associated IgA (SAIgA) release significant amounts of activated collagenase in addition to the granule proteins myeloperoxidase and lactoferrin. This activation is associated with release of superoxide as well as hydrogen peroxide and hypochlorous acid. Although neutrophils incubated with soluble aggregates of IgA also release granule proteins and produce superoxide, soluble aggregates of IgA do not trigger the release of activated collagenase and do not generate hydrogen peroxide or hypochlorous acid. In summary, neutrophils activated by surface associated IgA respond differently than when cells are activated by soluble aggregates of IgA. These differences may be important in understanding the mechanisms of tissue injury in patients with inflammatory disorders.","pmid":"7554445","doi":"10.1006/clin.1995.1122","url":"https://pubmed.ncbi.nlm.nih.gov/7554445/"},{"id":2953,"title":"Hypochlorite induces lipid peroxidation in blood lipoproteins and phospholipid liposomes.","authors":"Panasenko, O M; Evgina, S A; Driomina, E S; Sharov, V S; Sergienko, V I; Vladimirov, Y A","year":1995,"date":"1995 Aug","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The accumulation of lipid peroxidation products reacting with 2-thiobarbituric acid (TBARS) has been observed both in very low density blood lipoprotein (VLDL) and suspensions of liposomes prepared from VLDL phospholipids incubated with hypochlorite. Butylated hydroxytoluene (BHT) completely inhibited TBARS formation at a concentration of 100 microM, at which it decreased the concentration of hypochlorite in the absence of liposomes only by 7%. The formation of lipid peroxidation products in course of the incubation of egg yolk phospholipid liposomes with hypochlorite has been revealed using three methods: (1) measurement of TBARS, (2) measurement of additional amounts of TBARS resulting from the introduction of excess Fe2+ to peroxidized liposomes (delta TBARS), and (3) measurement of the chemiluminescence flash amplitude appeared upon the addition of Fe2+ to the suspension. The results obtained by all these methods were similar: Lipid peroxidation products were accumulated during the first 2 to 3 h of liposome incubation with 100 microM hypochlorite, and the amount of lipid peroxidation products accumulated after incubation was directly proportional to the initial hypochlorite concentration. These data suggest that hypochlorite can initiate lipid peroxidation both in lipoproteins and phospholipid liposomes.","pmid":"7649485","doi":"10.1016/0891-5849(94)00211-2","url":"https://pubmed.ncbi.nlm.nih.gov/7649485/"},{"id":2954,"title":"Cytoplasts generate oxidants but require added neutrophil granule constituents for fungicidal activity against Candida albicans hyphae.","authors":"Stein, D K; Malawista, S E; Van Blaricom, G; Wysong, D; Diamond, R D","year":1995,"date":"1995 Aug","journal":"The Journal of infectious diseases","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Killing of Candida albicans hyphae requires oxidant generation by neutrophils (PMNL), but it is uncertain whether hyphal killing is mediated by PMNL oxidants alone or requires contributions by granule constituents. This was assessed using U-cytoplasts (U-CYT), anucleate PMNL fragments depleted of cytoplasmic granules but retaining motility and respiratory burst activity. Granule-depleted U-CYT killed Staphylococcus aureus, but hyphae remained viable despite targeted generation of putatively fungicidal oxidants by avidly adherent U-CYT. Hyphal killing occurred by combining U-CYT with sublethal concentrations of purified PMNL granule extracts approximating those present in equivalent numbers of intact PMNL. Contributions of granule constituents were not entirely attributable to purified granule constituents with known antimicrobial activity (lactoferrin, cathepsin G, myeloperoxidase, and human neutrophil peptide defensins 1-3) individually or combined. Thus, oxidant generation by intact PMNL may be necessary but not always sufficient to mediate hyphal killing without complementary nonoxidative mechanisms.","pmid":"7622895","doi":"10.1093/infdis/172.2.511","url":"https://pubmed.ncbi.nlm.nih.gov/7622895/"},{"id":2957,"title":"Chlorination of tyrosyl residues in peptides by myeloperoxidase and human neutrophils.","authors":"Domigan, N M; Charlton, T S; Duncan, M W; Winterbourn, C C; Kettle, A J","year":1995,"date":"1995 Jul 14","journal":"The Journal of biological chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid is the major strong oxidant generated by human neutrophils, and it has the potential to cause much of the tissue damage that these inflammatory cells promote. It is produced from hydrogen peroxide and chloride by the heme enzyme myeloperoxidase. To unequivocally establish that hypochlorous acid contributes to inflammation, a stable and unique marker for its reaction with biomolecules needs to be identified. In this investigation we have found that reagent hypochlorous acid reacts with tyrosyl residues in small peptides and converts them to chlorotyrosine. Purified myeloperoxidase in combination with hydrogen peroxide and chloride, as well as stimulated human neutrophils, chlorinated tyrosine in the peptide Gly-Gly-Tyr-Arg. Rather than reacting directly with the aromatic ring of tyrosine, hypochlorous acid initially reacted with an amine group of the peptide to form a chloramine. The chloramine then underwent an intramolecular reaction with the tyrosyl residue to convert it to chlorotyrosine. This indicates that tyrosyl residues in proteins that are close to amine groups will be susceptible to chlorination. Peroxidases are the only enzymes capable of chlorinating an aromatic ring. Furthermore, myeloperoxidase is the only human enzyme that produces hypochlorous acid under physiological conditions. Therefore, chlorotyrosine will be a specific marker for the production of hypochlorous acid in vivo and for the involvement of myeloperoxidase in inflammatory tissue damage.","pmid":"7622459","doi":"10.1074/jbc.270.28.16542","url":"https://pubmed.ncbi.nlm.nih.gov/7622459/"},{"id":2962,"title":"Immunologic detection and measurement of hypochlorite-modified LDL with specific monoclonal antibodies.","authors":"Malle, E; Hazell, L; Stocker, R; Sattler, W; Esterbauer, H; Waeg, G","year":1995,"date":"1995 Jul","journal":"Arteriosclerosis, thrombosis, and vascular biology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Oxidation of LDL is thought to contribute to the early stages of atherogenesis. Because myeloperoxidase is present in atherosclerotic lesions and can produce the strong oxidant hypochlorous acid (HOCl), which converts LDL into its high-uptake atherogenic form in vitro, we raised polyclonal and monoclonal antibodies (MoAbs) against HOCl-modified LDL (HOCl-LDL). Characterization of the polyclonal anti-human HOCl-LDL Abs showed that they cross-reacted strongly with 4-hydroxynonenal-, malondialdehyde-, and Cu(2+)-oxidized LDL. Similarly, polyclonal and some monoclonal Abs against aldehyde- and Cu(2+)-modified LDL cross-reacted with HOCl-LDL. In contrast to the polyclonal Abs, two selected hybridoma cell line supernatants containing MoAbs raised against HOCl-LDL (MoAb-A and MoAb-B) did not cross-react with either native LDL or aldehyde- or Cu(2+)-modified LDL. MoAb-A (clone 1B10A11, subtype IgG1 kappa) recognized an epitope that appeared to be specific for HOCl-LDL and depended on the tertiary structure of the (lipo)protein, as judged by a lack of cross-reactivity with HOCl-modified human and bovine serum albumin and a loss of reactivity associated with lipoprotein denaturation. MoAb-B (clone 2D10G9, subtype IgG2b kappa), on the other hand, gave identical titration curves with HOCl-LDL and HOCl-modified albumins, suggesting that this antibody recognized epitopes that are commonly generated on proteins that have been oxidized with HOCl. Thus, MoAb-A and MoAb-B may be useful tools for the investigation of a possible role for HOCl-mediated damage to (lipo)proteins in atherosclerosis and other inflammatory diseases.","pmid":"7541296","doi":"10.1161/01.atv.15.7.982","url":"https://pubmed.ncbi.nlm.nih.gov/7541296/"},{"id":2965,"title":"[Oxidative stability of Na,K-ATPase].","authors":"Boldyrev, A A; Kurella, E G; Tiulina, O V","year":1995,"date":"1995 Jun","journal":"Doklady Akademii nauk","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"","pmid":"7580960","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/7580960/"},{"id":2970,"title":"[The technology of sewage purification and water treatment in self-contained oxidation-biosorption units].","authors":"Faĭngol'd, Z L; Terent'eva, N A; Nikolaev, V B; Beĭrit, A G; Sivacheva, O V; Vinogradova, T V","year":1995,"date":"1995 May","journal":"Antibiotiki i khimioterapiia = Antibiotics and chemoterapy [sic]","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"A technological process for oxybiosorption of sewage was developed. The process and a self-contained unit using it are described.","pmid":"8534178","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/8534178/"},{"id":2979,"title":"Hydrogen peroxide inhibits lung neutral endopeptidase.","authors":"Roisman, G L; Dusser, D J","year":1995,"date":"1995 Mar-Apr","journal":"Experimental lung research","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Oxidants have been implicated in the pathogenesis of many inflammatory airway diseases. Neutral endopeptidase (also called enkephalinase, EC 3.4.24.11) is a peptidase that is involved in the degradation of several proinflammatory peptides, such as tachykinins and kinins. Indirect evidence suggests that airway neutral endopeptidase is inactivated by oxidants. To determine whether hydrogen peroxide inactivates neutral endopeptidase, we studied the activity of this peptidase in washed crude preparations of membranes from guinea pig lungs. Washed crude membrane preparations were exposed to increasing concentrations of hydrogen peroxide (1.25-25 mM) in the presence or absence of two different concentrations of catalase (300 and 700 U/mL). Neutral endopeptidase activity was inhibited by hydrogen peroxide in a concentration-dependent fashion (p = .0001). Addition of catalase prevented, in a concentration-dependent fashion, the inhibition of neutral endopeptidase induced by hydrogen peroxide (p = .0001). Mannitol (40 mM) and L-methionine (20 mM) did not prevent inhibition of neutral endopeptidase induced by hydrogen peroxide (2.5 mM). It can be concluded that neutral endopeptidase is inactivated by hydrogen peroxide, an effect that is prevented by catalase. Hydrogen peroxide-induced inactivation of neutral endopeptidase is not mediated by spontaneous generation of either hydroxyl radical or hypochlorous acid in the membrane preparation. Our results suggest that neutral endopeptidase inactivation may occur in airway diseases associated with exposure to or production of oxidants.","pmid":"7774526","doi":"10.3109/01902149509068828","url":"https://pubmed.ncbi.nlm.nih.gov/7774526/"},{"id":2980,"title":"Oxidation of aminopyrine by hypochlorite to a reactive dication: possible implications for aminopyrine-induced agranulocytosis.","authors":"Uetrecht, J P; Ma, H M; MacKnight, E; McClelland, R","year":1995,"date":"1995 Mar","journal":"Chemical research in toxicology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Aminopyrine is associated with a high incidence of agranulocytosis. It is known to be oxidized by peroxidases and hypochlorous acid to a blue cation radical. It has been proposed that the mechanism by which hypochlorous acid oxidizes aminopyrine to a cation radical involves N-chlorination followed by loss of a chlorine radical. Another possible mechanism is loss of HCl to form an iminium ion and subsequent reaction with another molecule of aminopyrine and a hydrogen ion to form two radical cations. This mechanism would lead to incorporation of a hydrogen from water; however, using a deuterated analog, we found no hydrogen incorporation, thus providing strong evidence against this mechanism. Using a stopped-flow diode array spectrophotometer to study the reaction between aminopyrine and hypochlorous acid, an intermediate with a lambda max at approximately 420 nm was observed in the formation of the cation radical. We propose that this represents a dication formed by the loss of chloride ion from N-chloroaminopyrine. This intermediate is very reactive, with a half-life of approximately 15 ms, and in addition to being the precursor of the cation radical, it also appears to react with two molecules of water to form several other products that were observed and are consistent with the proposed dication intermediate. Similar stable products were formed when amino-pyrine was oxidized by the combination of myeloperoxidase, hydrogen peroxide, and chloride or activated neutrophils. The reactive dication formed by neutrophil-derived hypochlorous acid could be responsible for aminopyrine-induced agranulocytosis.","pmid":"7766805","doi":"10.1021/tx00044a007","url":"https://pubmed.ncbi.nlm.nih.gov/7766805/"},{"id":2988,"title":"Singlet molecular oxygen evolution upon simple acidification of aqueous hypochlorite: application to studies on the deleterious health effects of chlorinated drinking water.","authors":"Khan, A U; Kasha, M","year":1994,"date":"1994 Dec 20","journal":"Proceedings of the National Academy of Sciences of the United States of America","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"A study of the pH profile of the decomposition of aqueous hypochlorite has revealed the evolution (onset at pH 8) of single (1 delta g) molecular oxygen (singlet spin state dioxygen) detected spectroscopically (1268 nm), prior to the appearance of chlorine (onset at pH 5.5). The possible mechanism of the singlet state dioxygen evolution is presented, and the origin of its chloride ion dependence is discussed, especially in reference to chloride ion dependence of singlet molecular oxygen evolution in biological systems. Recent epidemiological analyses of the correlation of human cancer with chlorinated water supplies focus attention on the singlet oxygen mechanisms of DNA lesion formation.","pmid":"7809041","doi":"10.1073/pnas.91.26.12362","url":"https://pubmed.ncbi.nlm.nih.gov/7809041/"},{"id":2990,"title":"Multi-agent therapy in the treatment of sepsis-induced microvascular injury.","authors":"Carey, P D; Windsor, A C; Walsh, C J; Fowler, A A; Sugerman, H J","year":1994,"date":"1994 Dec","journal":"The British journal of surgery","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Cyclo-oxygenase inhibition (with ibuprofen) combined with histamine (H1, H2) receptor antagonism (with diphenhydramine and cimetidine) attenuates microvascular leak injury in sepsis syndromes. Ibuprofen reduces microvascular injury by limiting oxygen radical production by neutrophils. Histamine is known to inhibit this oxygen radical production, an effect antagonized by cimetidine. In the present study neutrophils isolated from pigs made septic with Pseudomonas organisms exhibited a significant (P < 0.05) increase in the production of the oxygen radicals, superoxide anion (O2-, 133 per cent) and hypochlorous acid (HOCl, 38 per cent). Ibuprofen used alone attenuated this sepsis-stimulated overproduction. Addition of the antihistamines cimetidine and diphenhydramine produced a significant increase in oxygen radical production (P < 0.05), by 122 per cent (O2-) and 47 per cent (HOCl), equivalent to that in untreated septic animals. This coincided with a significant deterioration in pulmonary compliance (P < 0.05) compared with that found in control animals and those treated with ibuprofen alone, and a significant accumulation of extravascular lung water (P < 0.05) at 240 and 300 min versus baseline. Histamine receptor antagonism may inadvertently enhance microvascular injury in sepsis.","pmid":"7827930","doi":"10.1002/bjs.1800811214","url":"https://pubmed.ncbi.nlm.nih.gov/7827930/"},{"id":2992,"title":"Chloride channel blockers inhibit the Na+/I- symporter in thyroid follicles in culture.","authors":"Gerard, C; Rigot, V; Penel, C","year":1994,"date":"1994 Nov 15","journal":"Biochemical and biophysical research communications","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Porcine thyroid cells in culture are able to reorganize into well-polarized follicle-like structures in the presence of cAMP analogs. These follicles exhibit on their basolateral membrane domain the Na+/I- symporter which allows iodide to accumulate in the thyrocytes. The initial rate of iodide influx through the Na+/I- symporter is inhibited up to 98% by the chloride channel blockers. 5 nitro-2(3-phenylpropylamino)benzoic acid and 3',5-Dichlorodiphenylamine-2-carboxylic acid are the most effective inhibitors, with a K0.5 value of 60 microM. This inhibition is not secondary to inhibition of chloride transport. Other chloride transporter blockers have been studied but showed lesser activities.","pmid":"7980604","doi":"10.1006/bbrc.1994.2599","url":"https://pubmed.ncbi.nlm.nih.gov/7980604/"},{"id":2993,"title":"Determinants of neutrophil HOCl generation: ligand-dependent responses and the role of surface adhesion.","authors":"Chatham, W W; Turkiewicz, A; Blackburn, W D Jr","year":1994,"date":"1994 Nov","journal":"Journal of leukocyte biology","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Neutrophil (PMN) generation of HOCl, an oxidant important in mediating tissue injury by PMN proteases, requires PMN production of H2O2 and the catalytic activity of myeloperoxidase (MPO). Production of H2O2 and MPO release vary with the PMN activating ligand and are facilitated by cellular adhesion. Leukotriene B4, platelet-activating factor, heat-aggregated immunoglobulin G (HAIgG), tumor necrosis factor alpha (TNF-alpha), and f-Met-Leu-Phe (fMLP) all triggered significant superoxide production but negligible H2O2 or HOCl generation when added to suspended PMNs. Production of H2O2 was observed when fMLP, TNF-alpha, or HAIgG was added to PMNs adherent to bovine serum albumin (BSA)-coated wells, but significant production of HOCl was observed only when HAIgG was added to PMNs adherent to BSA-coated wells or when suspended PMNs treated with TNF-alpha were allowed to settle in BSA-coated wells. Even greater production of both H2O2 and HOCl was observed when PMNs were incubated in wells coated with IgG (SAIgG). HOCl generation, when observed, was accompanied by release of MPO. Nonadherent PMNs generated HOCl when treated with 50-100 ng/ml phorbol myristate acetate or when stimulated with fMLP following treatment with cytochalasin B; PMN activation under these conditions was also associated with MPO release but HOCl production was much less efficient relative to PMNs stimulated by SAIgG. These studies indicate that surface adhesion and ligand-induced responses that facilitate release of myeloperoxidase and dismutation of superoxide to H2O2 are required for production of extracellularly released HOCl; these responses are most efficiently utilized during PMN interaction with SAIgG.","pmid":"7964173","doi":"10.1002/jlb.56.5.654","url":"https://pubmed.ncbi.nlm.nih.gov/7964173/"},{"id":2994,"title":"Interactions of human blood plasma with hydrogen peroxide and hypochlorous acid.","authors":"van der Vliet, A; Hu, M L; O'Neill, C A; Cross, C E; Halliwell, B","year":1994,"date":"1994 Nov","journal":"The Journal of laboratory and clinical medicine","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Activated neutrophils produce both hydrogen peroxide (H2O2) and hypochlorous acid (HOCl). Previous work has shown that HOCl depletes antioxidants, modifies proteins, and forms fatty acid chlorohydrins but does not cause significant lipid peroxidation in human plasma. Because activated phagocytes have been claimed to stimulate lipid peroxidation in plasma, we examined the effects of H2O2 and HOCl alone and in combination on plasma constituents. Hydrogen peroxide at concentrations below 0.5 mmol/L had little effect, but 1 to 2 mmol/L H2O2 caused loss of ascorbic acid and protein thiol groups, an effect potentiated by preincubation of the plasma with sodium azide to inhibit catalase. H2O2 caused no detectable lipid peroxidation or loss of alpha-tocopherol in plasma, but some depletion of ubiquinol occurred. The combination of HOCl and H2O2 caused more lipid peroxidation than either agent alone. Peroxidation was not inhibited by the metal chelators ethylenediaminetetraacetic acid and deferoxamine or by the singlet O2/hydroxyl radical scavenger histidine. We hypothesize that the phagocyte-derived H2O2 and HOCl could interact in the microenvironment of the activated leukocyte to induce lipid peroxidation of plasma lipoproteins or cell membranes (or both).","pmid":"7964128","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/7964128/"},{"id":2996,"title":"Hypochlorite solution as a decontaminant in sulfur mustard contaminated skin defects in the euthymic hairless guinea pig.","authors":"Gold, M B; Bongiovanni, R; Scharf, B A; Gresham, V C; Woodward, C L","year":1994,"date":"1994 Nov","journal":"Drug and chemical toxicology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Hypochlorite solutions are thought to be efficacious when used to topically decontaminate intact skin. However, few studies have examined the efficacy of decontamination of chemically contaminated wounds. Therefore, we compared the decontamination efficacy of sodium hypochlorite (0.5% and 2.5% solutions), calcium hypochlorite (0.5% and 2.5% solutions) and sterile water to untreated controls in wounds exposed to sulfur mustard (HD). Anesthetized euthymic hairless guinea pigs (EHGP) (n = 6) were exposed to 20 mg/kg (approximately 0.4 LD50) HD in a full-thickness 8 mm surgical biopsy skin defect (i.e., wound). Each animal was subsequently decontaminated, after a two-minute intra-wound exposure to liquid HD, with nothing or one of the decontamination solutions. Decontamination efficacy was determined by the visual grading of the HD-traumatized wound lesion and by comparison of the expected HD-induced leukocyte suppression. Leukocyte suppression was inconsistent in all animals; therefore, the visual grading was the only viable evaluation method. No significant differences were observed among wounds decontaminated with any of the solutions. However, the skin surrounding non-decontaminated (but exposed) control animals showed the least visual pathology. The lesions induced following decontamination are presumed to be due to the mechanical flushing of HD onto the peri-lesional skin, or by chemical damage induced by the solution, or HD-solution interaction. Further studies are required to best delineate the optimal decontamination process for HD contaminated wounds.","pmid":"7821235","doi":"10.3109/01480549409014314","url":"https://pubmed.ncbi.nlm.nih.gov/7821235/"},{"id":2997,"title":"Hypochlorous acid and chloramines increase endothelial permeability: possible involvement of cellular zinc.","authors":"Tatsumi, T; Fliss, H","year":1994,"date":"1994 Oct","journal":"The American journal of physiology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The migration of neutrophils through the endothelium at sites of inflammation may be facilitated by oxidant-mediated disruption of cellular junctions. The present study examined the effects of noncytotoxic concentrations of the membrane-penetrating neutrophil oxidants hypochlorous acid (HOCI) and monochloramine (NH2Cl), or the membrane-impermeant taurine chloramine (taurine NCl), on cultured bovine aorta endothelial monolayers. HOCl (25 microM) or NH2Cl (10 microM), but not taurine NCl (100 microM), caused a reversible shortening of the cytoskeletal actin microfilaments, cell retraction, and increased permeability within 2 min. These effects were accompanied by an increase in intracellular zinc concentration as well as the oxidation of intracellular glutathione and protein sulfhydryls. The zinc ionophore pyrithione also increased permeability. HOCl or NH2Cl, but not taurine NCl, also rapidly increased microvascular permeability in isolated perfused rat lungs. The data suggest that HOCl and NH2Cl can increase endothelial permeability by causing very rapid cytoskeletal shortening and cell retraction, possibly as a result of the oxidation of intracellular sulfhydryls and mobilization of zinc.","pmid":"7943407","doi":"10.1152/ajpheart.1994.267.4.H1597","url":"https://pubmed.ncbi.nlm.nih.gov/7943407/"},{"id":2999,"title":"Effects of the reactive oxygen species hypochlorous acid and hydrogen peroxide on force production and calcium sensitivity of rat cardiac myofilaments.","authors":"MacFarlane, N G; Miller, D J","year":1994,"date":"1994 Oct","journal":"Pflugers Archiv : European journal of physiology","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Neutrophil activation occurs after myocardial infarction/ischaemia. They produce the reactive oxygen species (ROS) hypochlorous acid (HOCl) and hydrogen peroxide (H2O2) which could contribute to contractile dysfunction upon reperfusion. The myofilaments of 'skinned' rat cardiac muscle were exposed to ROS in various states of activation. Isometric force was measured at controlled degrees of activation. A single application of 10 microM HOCl for 1 min increased log [Ca2+] for half-maximal activation (log K1/2) from 5.23 to 5.32, initial maximum Ca-activated force (FCa, max) was reduced by 18.8 +/- 5.8% and resting tension increased to 15.4 +/- 8.0% of FCa, max. At 50 microM, a 1-min exposure to HOCl produced a greater increase in Ca-sensitivity (log K1/2 increased from 5.23 to 5.47), a greater reduction in FCa, max (falling by 42.3 +/- 23.2%) and a greater increase in resting tension (to 25 +/- 10.7% of FCa, max). The nature of the resting tension rise was examined by reducing pH before and during exposure to HOCl; the results are consistent with 'rigor-like' cross-bridges being involved. H2O2 was without effect on the myofilaments at physiologically relevant (< 10 microM) concentrations. These results suggest that ROS associated with inflammation could contribute to post-ischaemic myocardial dysfunction.","pmid":"7838678","doi":"10.1007/BF00374578","url":"https://pubmed.ncbi.nlm.nih.gov/7838678/"},{"id":3001,"title":"Cholesterol chlorohydrin synthesis by the myeloperoxidase-hydrogen peroxide-chloride system: potential markers for lipoproteins oxidatively damaged by phagocytes.","authors":"Heinecke, J W; Li, W; Mueller, D M; Bohrer, A; Turk, J","year":1994,"date":"1994 Aug 23","journal":"Biochemistry","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase, a heme protein secreted by activated phagocytes, uses hydrogen peroxide to produce potent cytotoxins. One important substrate is chloride, which is converted to hypochlorous acid (HOCl). This diffusible oxidant plays a critical role in the destruction of invading pathogens. Under pathological conditions, HOCl may also injure normal tissue. Recent studies have shown that myeloperoxidase is a component of human atherosclerotic lesions. Because oxidized lipoproteins may play a central role in atherogenesis, we have explored the possibility that cholesterol is a target for damage by myeloperoxidase. Three major classes of sterol oxidation products were apparent when cholesterol-phosphatidylcholine multilamellar vesicles which had been exposed to a myeloperoxidase-hydrogen peroxide-chloride system were subsequently analyzed by normal-phase thin layer chromatography. The products were identified by gas chromatography-mass spectrometry as cholesterol alpha- and beta-chlorohydrins (6 beta-chlorocholestane-3 beta,5 alpha-diol and 5 alpha-chlorocholestane-3 beta,6 beta-diol), cholesterol alpha- and beta-epoxides (cholesterol 5 alpha,6 alpha-epoxide and cholesterol 5 beta,6 beta-epoxide), and a novel cholesterol chlorohydrin. Conversion of cholesterol to the oxidation products required active myeloperoxidase, hydrogen peroxide, and halide and could be blocked by catalase or by scavengers of HOCl. Moreover, in the absence of the enzymatic system, reagent HOCl generated the same distribution of products. These results indicate that myeloperoxidase can convert cholesterol to chlorohydrins and epoxides by a reaction involving HOCl. Other oxygenated sterols are cytotoxic and mutagenic and are potent regulators of cholesterol homeostasis in cultured mammalian cells. Cholesterol chlorohydrins might similarly mediate powerful biological effects in the artery wall. Because chlorohydrins are stable under our experimental conditions, chlorinated sterols may prove useful as markers for lipoproteins oxidatively damaged by activated phagocytes.","pmid":"8060981","doi":"10.1021/bi00199a041","url":"https://pubmed.ncbi.nlm.nih.gov/8060981/"},{"id":3004,"title":"Water chlorination, mutagenicity, and cancer epidemiology.","authors":"Cantor, K P","year":1994,"date":"1994 Aug","journal":"American journal of public health","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"","pmid":"8059872","doi":"10.2105/ajph.84.8.1211","url":"https://pubmed.ncbi.nlm.nih.gov/8059872/"},{"id":3011,"title":"Superoxide-dependent hydroxylation by myeloperoxidase.","authors":"Kettle, A J; Winterbourn, C C","year":1994,"date":"1994 Jun 24","journal":"The Journal of biological chemistry","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"When stimulated, neutrophils undergo a respiratory burst converting oxygen to superoxide. Although superoxide is critical for microbial killing by phagocytic cells, the precise role it plays has yet to be established. It has been proposed to optimize their production of hypochlorous acid and to be required for the generation of hydroxyl radicals. Superoxide is also involved in the hydroxylation of salicylate by neutrophils. However, the mechanism of this reaction is unknown. We found that neutrophils stimulated with opsonized zymosan hydroxylated salicylate to produce mainly 2,5-dihydroxybenzoate. Its formation was dependent on superoxide and a heme protein but was independent of hydrogen peroxide and hydroxyl radicals. Production of 2,5-dihydroxybenzoate was enhanced by methionine, which scavenges hypochlorous acid. Neutrophils from an individual with myeloperoxidase deficiency hydroxylated salicylate at only 13% of the level of control cells. Purified human myeloperoxidase and xanthine oxidase plus hypoxanthine hydroxylated salicylate to produce 2,5-dihydroxybenzoate. As with neutrophils, the reaction required superoxide but not hydrogen peroxide and was unaffected by hydroxyl radical scavengers. Thus, myeloperoxidase catalyzes superoxide-dependent hydroxylation. This newly recognized reaction may be relevant to the in vivo functions of superoxide and myeloperoxidase.","pmid":"8006021","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/8006021/"},{"id":3013,"title":"Structural characteristics of histamine H2 receptor antagonists that scavenge hypochlorous acid.","authors":"Ching, T L; de Jong, J; Bast, A","year":1994,"date":"1994 Jun 15","journal":"European journal of pharmacology","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Gastric and duodenal ulcers are characterized by hypersecretion of gastric acid and pepsin, inflammation of the mucosa and an influx of neutrophils. These cells can produce reactive oxygen species after stimulation. Particularly hydroxyl radicals and hypochlorous acid (HOCl) can be cytotoxic and damage the gastroduodenal mucosa. It has been shown that histamine H2 receptor antagonists such as cimetidine, ranitidine and famotidine are good hydroxyl radical scavengers. This study was undertaken to investigate whether these agents were able to scavenge the cytotoxic HOCl, and if so, which part of the molecule could be responsible for this action. It appears that the sulfur atom in the compound is of importance for scavenging HOCl. This finding should be taken into consideration in the development of new anti ulcer drugs, as HOCl is a detrimental factor in the pathophysiology of gastroduodenal ulcers.","pmid":"7925615","doi":"10.1016/0922-4106(94)90123-6","url":"https://pubmed.ncbi.nlm.nih.gov/7925615/"},{"id":3014,"title":"HOCl production by human neutrophils activated by surface-associated IgG: requirement for influx of extracellular calcium.","authors":"Blackburn, W D Jr; Chatham, W W","year":1994,"date":"1994 Jun","journal":"Journal of leukocyte biology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Neutrophils produce large quantities of HOCl when stimulated by surface-associated immunoglobulin G, a result not seen when neutrophils are stimulated with soluble complexes of IgG. Compared with unactivated cells or cells stimulated with soluble aggregates of IgG, a significant influx of extracellular 45Ca2+ was observed in cells activated by surface-associated IgG. Removal of extracellular calcium with EGTA almost completely blocked HOCl production. Similarly, treatment of neutrophils with lanthanum, which has been shown to interfere with calcium channels, also effectively blocked HOCl production. These results were not secondary to an overall decrease in activation, as superoxide production and release of the specific granule protein lactoferrin and the azurophilic granule protein myeloperoxidase were not significantly altered by lanthanum or EGTA. Production of H2O2, the precursor of HOCl, was similarly decreased by both EGTA and lanthanum. Induction of extracellular calcium influx with a calcium ionophore in the presence of soluble aggregates of IgG resulted in HOCl production. Production of HOCl is not sensitive to inhibition by pretreatment of cells with pertussis toxin. These observations indicate that the differences in the biological responses of human neutrophils to surface-associated IgG compared with soluble aggregates of IgG are associated with differing signaling events, including influx of extracellular calcium.","pmid":"8195705","doi":"10.1002/jlb.55.6.793","url":"https://pubmed.ncbi.nlm.nih.gov/8195705/"},{"id":3018,"title":"A method for screening hypochlorous acid scavengers by inhibition of the oxidation of 5-thio-2-nitrobenzoic acid: application to anti-asthmatic drugs.","authors":"Ching, T L; de Jong, J; Bast, A","year":1994,"date":"1994 May 1","journal":"Analytical biochemistry","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Neutrophils use a bactericidal mechanism through the release of the enzyme myeloperoxidase which catalyzes the formation of the powerful oxidant hypochlorous acid (HOCl) from H2O2 and Cl-. HOCl can inactivate alpha 1-antiproteinase (alpha 1-AP) which causes increased proteolytic activity at sites of pulmonary inflammation. The search for possible HOCl scavengers usually involves time-consuming enzyme assays (e.g., alpha 1-AP and elastase). We developed a method in which the compound 5-thio-2-nitrobenzoic acid could easily be oxidized by HOCl. The inhibition of this oxidation by a test compound is a measurement of its HOCl scavenging activity. To illustrate the method we tested some well-known HOCl scavengers such as S-methylated glutathione and oxidized lipoate. Finally several anti-asthmatic drugs such as terbutaline, isoproterenol, salbutamol, cromoglycate, theophylline, and dexamethasone were evaluated. Only the drug terbutaline acted as a HOCl scavenger.","pmid":"8074296","doi":"10.1006/abio.1994.1195","url":"https://pubmed.ncbi.nlm.nih.gov/8074296/"},{"id":3021,"title":"Effects of minimally invasive surgery on hypochlorous acid production by neutrophils.","authors":"Carey, P D; Wakefield, C H; Thayeb, A; Monson, J R; Darzi, A; Guillou, P J","year":1994,"date":"1994 Apr","journal":"The British journal of surgery","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"The production of chlorinated oxidants such as hypochlorous acid is a central antimicrobial and immunoregulatory function of neutrophils. Neutrophil hypochlorous acid production was compared in patients undergoing uncomplicated laparoscopic surgery (group 1) and those submitted to conventional open surgery (group 2). Preoperative peak hypochlorous acid production was similar in the two groups (mean(s.e.m.) 0.60(0.05) versus 0.69(0.06) nmol/min respectively). In group 2, mean(s.e.m.) neutrophil hypochlorous acid production fell significantly on day 1 after surgery (0.36(0.05) nmol/min; P < 0.01) but this did not occur in group 1 (0.63(0.07) nmol/min). By day 6 hypochlorous acid kinetics had returned to preoperative levels in both groups. Minimally invasive surgery is less disruptive of neutrophil function than conventional open procedures.","pmid":"8205435","doi":"10.1002/bjs.1800810425","url":"https://pubmed.ncbi.nlm.nih.gov/8205435/"},{"id":3025,"title":"Antioxidant properties of Ambroxol.","authors":"Nowak, D; Antczak, A; Król, M; Bialasiewicz, P; Pietras, T","year":1994,"date":"1994 Apr","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"We tested whether Ambroxol, a drug which stimulates the release of surfactant by pneumocytes type II, may also possess antioxidant properties. To assess the reactivity of Ambroxol with reactive oxygen species, we analysed its ability to decompose hydrogen peroxide (H2O2) and to inhibit the superoxide (O2.-)-dependent autooxidation of pyrogallol, hydroxyl radical (.OH)-mediated deoxyribose oxidation, and hypochlorous acid (HClO-induced chlorination of monochlorodimedon. Ambroxol was found to be a sufficient scavenger of HClO and .OH and also revealed the capacity to decompose H2O2. At concentrations of 25 and 70 microM, it inhibited HClO-induced chlorination of monochlorodimedon by 22 +/- 13 and 59 +/- 14%, respectively. Similarly, at concentrations of 1, 2, and 10 mM, Ambroxol decreased .OH-mediated deoxyribose oxidation by 47 +/- 11, 75 +/- 9, and 89 +/- 4%. In addition, at concentrations of 1 to 5 mM, it completely protected linoleic acid from .OH-induced peroxidative damage. Ambroxol had a weak effect on O2.(-)-dependent autooxidation of pyrogallol. Our results indicate that Ambroxol has antioxidant activity, which may have clinical significance in protecting lung tissue from oxidant-induced injury.","pmid":"8005537","doi":"10.1016/0891-5849(94)90130-9","url":"https://pubmed.ncbi.nlm.nih.gov/8005537/"},{"id":3027,"title":"Inhibition of collagenase activity by N-chlorotaurine, a product of activated neutrophils.","authors":"Davies, J M; Horwitz, D A; Davies, K J","year":1994,"date":"1994 Mar","journal":"Arthritis and rheumatism","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"OBJECTIVE: To study the effects of N-chlorotaurine on collagenase activity, as a model of the effects of neutrophil activation in inflammatory arthritis. METHODS: Collagen degradation by collagenase was measured by the release of acid-soluble counts from 3H-collagen. RESULTS: N-chlorotaurine inhibited the degradation of collagen by bacterial collagenase. This result is explained by a direct inhibition/inactivation of collagenase, since N-chlorotaurine had no effect on the proteolytic susceptibility of collagen itself. The effect appears to be specific to N-chlorotaurine since N-chloroalanine, N-chloroleucine, and HOCl/OCl- failed to inhibit collagenase; in fact, N-chloroalanine and N-chloroleucine actually increased the proteolytic susceptibility of collagen. CONCLUSION: N-chlorotaurine may minimize damage to cartilaginous joint structures in inflammatory arthritis by inhibiting/inactivating collagenase.","pmid":"8129798","doi":"10.1002/art.1780370317","url":"https://pubmed.ncbi.nlm.nih.gov/8129798/"},{"id":3029,"title":"The action of hypochlorous acid on polymeric components of cartilage.","authors":"Schiller, J; Arnhold, J; Gründer, W; Arnold, K","year":1994,"date":"1994 Mar","journal":"Biological chemistry Hoppe-Seyler","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"The action of sodium hypochlorite on N-acetylglucosamine, N-acetylgalactosamine, chondroitinsulfate and hyaluronic acid was studied by 1H-nuclear magnetic resonance (1H-NMR) in order to model some aspects of degradation processes caused by neutrophils on carbohydrate polymers of cartilage in rheumatoid arthritis. N-Acetyl side groups of carbohydrate monomers and chondroitinsulfate yield a resonance at 2.01-2.04 ppm in proton NMR-spectra. This resonance is observed in hyaluronic acid solutions only after a prolonged incubation to yield shorter polymeric chains. Sodium hypochlorite causes a continuous decrease of the line for N-acetyl groups. Two new resonances appear in the 1H-NMR spectra. An intermediate product, assumed as a chlorinated product of N-acetyl side chains, shows a chemical shift of about 2.35 ppm. This intermediate is hydrolyzed to a carbohydrate ring and acetate (1.90 ppm). Sodium hypochlorite acts in all systems investigated mainly on N-acetyl groups. Only small effects on the carbohydrate ring were found under our experimental conditions.","pmid":"8011173","doi":"10.1515/bchm3.1994.375.3.167","url":"https://pubmed.ncbi.nlm.nih.gov/8011173/"},{"id":3032,"title":"Peroxidation of human blood lipoproteins induced by exogenous hypochlorite or hypochlorite generated in the system of \"myeloperoxidase + H2O2 + Cl-\".","authors":"Panasenko, O M; Evgina, S A; Aidyraliev, R K; Sergienko, V I; Vladimirov, Y A","year":1994,"date":"1994 Feb","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Oxidation of human plasma lipoprotein (LP) was studied in the presence of exogenous hypochlorite anion (OCl-) or OCl- generated in the \"myeloperoxidase + H2O2 + Cl-\" system. OCl- effectively initiates peroxidation of lipids extracted from LP and those within LP particles, as can be judged from accumulation of secondary (thiobarbituric acid [TBA] reactive) and final (Schiff bases) products of lipid peroxidation (LPO) in LP after incubation with myeloperoxidase or exogenous OCl-. Very low density and low density lipoproteins classified as atherogenic LP are more sensitive to OCl(-)-induced LPO than high density lipoproteins. These data allow us to propose that OCl- secreted by activated neutrophils and monocyte-macrophages can produce oxidative modification of LP in vivo. The latter is known as a risk factor in the development of atherosclerosis.","pmid":"8005509","doi":"10.1016/0891-5849(94)90137-6","url":"https://pubmed.ncbi.nlm.nih.gov/8005509/"},{"id":3033,"title":"Lipoic and dihydrolipoic acids as antioxidants. A critical evaluation.","authors":"Scott, B C; Aruoma, O I; Evans, P J; O'Neill, C; Van der Vliet, A; Cross, C E; Tritschler, H; Halliwell, B","year":1994,"date":"1994 Feb","journal":"Free radical research","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"A detailed evaluation of the antioxidant and pro-oxidant properties of lipoic acid (LA) and dihydrolipoic acid (DHLA) was performed. Both compounds are powerful scavengers of hypochlorous acid, able to protect alpha 1-antiproteinase against inactivation by HOCl. LA was a powerful scavenger of hydroxyl radicals (OH.) and could inhibit both iron-dependent OH. generation and peroxidation of ox-brain phospholipid liposomes in the presence of FeCl3-ascorbate, presumably by binding iron ions and rendering them redox-inactive. By contrast, DHLA accelerated iron-dependent OH. generation and lipid peroxidation, probably by reducing Fe3+ to Fe2+. LA inhibited this pro-oxidant action of DHLA. However, DHLA did not accelerate DNA degradation by a ferric bleomycin complex and slightly inhibited peroxidation of arachidonic acid by the myoglobin-H2O2 system. Under certain circumstances, DHLA accelerated the loss of activity of alpha-antiproteinase exposed to ionizing radiation under a N2O/O2 atmosphere and also the loss of creatine kinase activity in human plasma exposed to gas-phase cigarette smoke. Neither LA nor DHLA reacted with superoxide radical (O.2-) or H2O2 at significant rates, but both were good scavengers of trichloromethylperoxyl radical (CCl3O2.). We conclude that LA and DHLA have powerful antioxidant properties. However, DHLA can also exert pro-oxidant properties, both by its iron ion-reducing ability and probably by its ability to generate reactive sulphur-containing radicals that can damage certain proteins, such as alpha 1-antiproteinase and creatine kinase.","pmid":"7516789","doi":"10.3109/10715769409147509","url":"https://pubmed.ncbi.nlm.nih.gov/7516789/"},{"id":3034,"title":"Proteolytic inactivation of alpha-1-antitrypsin by human neutrophils: involvement of multiple and interlinked cell responses to phagocytosable targets.","authors":"Ottonello, L; Dapino, P; Scirocco, M; Dallegri, F; Sacchetti, C","year":1994,"date":"1994 Jan","journal":"European journal of clinical investigation","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Neutrophil polymorphonuclear leukocytes (PMN) can inactivate the PMN-elastase inhibitor alpha-1-antitrypsin (A1AT) proteolytically, by using metalloproteinases normally stored as zymogens in myeloperoxidase (MPO)-negative granules. Supernatants from opsonized zymosan (OPZ)-triggered human PMN cleaved and inactivated human A1AT through a process inhibitable by metal-chelators, suggesting that the interaction of PMN with OPZ leads to the extracellular availability of active metalloenzymes. During OPZ-triggering, PMN used approximately 80% of the generated hydrogen peroxide (H2O2) to produce HOCl by means of the MPO pathway, while the remainder was catabolized by PMN themselves. No H2O2 was available as free compound in the extracellular environment and hydroxyl (.OH) or .OH-like radicals were not generated. The selective deletion of single components of the HOCl-generating MPO pathway resulted in the generation of PMN supernatants free of active metalloenzymes but rich of the corresponding zymogens. Similar results were obtained by replacing normal PMN with cells from a patient with hereditary MPO deficiency. No evidence was obtained for the intervention or contribution of .OH-like radicals, serine-proteinases and oxidized glutathione in the transformation of the zymogens into enzymes able to inactivate A1AT. On concluding, PMN undergoing phagocytosis release MPO in amount sufficient to handle the extracellular pool of the generated H2O2 entirely, leading to the generation of equimolar amounts of HOCl. In turn, HOCl or a similar compound derived from it interacts with concomitantly released metallozymogens, switching on their A1AT inactivating potential without the apparent contribution of other PMN-derived molecules.(ABSTRACT TRUNCATED AT 250 WORDS)","pmid":"8187807","doi":"10.1111/j.1365-2362.1994.tb02058.x","url":"https://pubmed.ncbi.nlm.nih.gov/8187807/"},{"id":3036,"title":"Neutrophil function and dysfunction in periodontal disease.","authors":"Van Dyke, T E; Vaikuntam, J","year":1994,"date":"1994","journal":"Current opinion in periodontology","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"The polymorphonuclear leukocyte or neutrophil is an integral part of the acute inflammatory response. Its function as a protective cell in the pathogenesis of periodontal disease has been studied extensively. Abnormal neutrophil function has been associated (directly or indirectly) with the pathogenesis of early onset periodontal disease. This paper reviews the recent developments in neutrophil function and dysfunction as they relate to periodontal disease progression.","pmid":"8032460","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/8032460/"},{"id":3038,"title":"Assays for the chlorination activity of myeloperoxidase.","authors":"Kettle, A J; Winterbourn, C C","year":1994,"date":"1994","journal":"Methods in enzymology","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"","pmid":"8015486","doi":"10.1016/s0076-6879(94)33056-5","url":"https://pubmed.ncbi.nlm.nih.gov/8015486/"},{"id":3040,"title":"Inhibition of nucleoside transport by reactive oxygen species in bovine heart microvascular endothelial cells.","authors":"Barankiewicz, J; Uyesaka, J; Kossenjans, W; Rymaszewski, Z","year":1994,"date":"1994","journal":"Advances in experimental medicine and biology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"","pmid":"7661020","doi":"10.1007/978-1-4615-2584-4_162","url":"https://pubmed.ncbi.nlm.nih.gov/7661020/"},{"id":3042,"title":"Potential roles of hypochlorous acid and N-chloroamines in collagen breakdown by phagocytic cells in synovitis.","authors":"Davies, J M; Horwitz, D A; Davies, K J","year":1993,"date":"1993 Dec","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"We have tested the effects of the neutrophil/macrophage products, hypochlorous acid (HOCl) and N-chloroamines, on the structural integrity and proteolytic susceptibility of collagen to determine if these agents could play a role in inflammatory joint destruction. Rates of HOCl reaction with collagen, and collagen gelation were monitored by spectrophotometric methods. Direct fragmentation, and degradation by collagenase were measured by the release of acid-soluble counts from 3H-collagen. Physiologically relevant concentrations of HOCl (5-50 microM) reacted rapidly and quantitatively at several sites in the collagen polypeptide chain, causing extensive protein fragmentation and preventing collagen gelation. In contrast, reaction with (5-50 microM) N-chloroalanine induced little direct collagen fragmentation. Oxidative damage by N-chloroamines was, however, evident because collagen displayed greatly increased proteolytic susceptibility following N-chloroamine treatment. Collagen degradation by collagenase increased as much as 3-fold after exposure to N-chloroamine treatment. Collagen degradation by collagenase increased as much as 3-fold after exposure to N-chloroalanine. N-chloroleucine caused a small increase in proteolytic susceptibility, but N-chlorotaurine had no effect. Collagen fragmentation by HOCl, inhibition of gelation by HOCl, and N-chloroalanine-induced proteolytic susceptibility, all increased with linear kinetics at oxidant concentrations of 5 microM to 1.0 mM. In synovitis, phagocytes expose collagen to HOCl, N-chloroamines, and collagenase. It is known that HOCl can activate neutrophil procollagenase. Based on our new findings, we propose a model of inflammatory joint destruction that also includes collagen fragmentation, and increased susceptibility of collagen to degradation by collagenase.(ABSTRACT TRUNCATED AT 250 WORDS)","pmid":"8138190","doi":"10.1016/0891-5849(93)90167-s","url":"https://pubmed.ncbi.nlm.nih.gov/8138190/"},{"id":3052,"title":"Acadesine prevents oxidant-induced damage in the isolated guinea pig heart.","authors":"Bullough, D A; Potter, S; Fox, M H; Zhang, C; Metzner, E K; Mullane, K M","year":1993,"date":"1993 Aug","journal":"The Journal of pharmacology and experimental therapeutics","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Acadesine is a cardioprotective nucleoside that can attenuate postischemic contractile dysfunction in the isolated heart even if administered at reperfusion, thereby implying an effect on a reperfusion-induced component of injury. Consequently, the effects of acadesine on the maintenance of cardiac function were evaluated in isolated guinea pig hearts in which the perfusion buffer was subjected to electrolysis to produce a mixture of free radicals and oxidants that have been implicated in reperfusion injury. A reduction of left ventricular developed pressure to 38 +/- 3% at 10 min after electrolysis was prevented by acadesine in a concentration-dependent manner (EC50 1 microM). Hypochlorous acid (HOCl) is a principal oxidizing species implicated in electrolysis-induced myocardial damage, and it is a major oxidant produced by neutrophils. Isolated hearts, perfused with HOCl to induce damage, were also protected by acadesine (EC50 1-3 microM). In addition, acadesine protected alpha 1-antiproteinase (alpha 1-AP) against inactivation by 30 microM HOCl with an EC50 of approximately 10 microM, demonstrating that acadesine reacts rapidly enough with HOCl to protect important biological targets. Additionally, acadesine scavenged the hydroxyl radical with a second-order rate constant of 5.0 x 10(9) M-1 s-1. In contrast, acadesine had no effect on superoxide anions generated from either xanthine-xanthine oxidase or hydrogen peroxide-mediated peroxidation. The free base of acadesine 5-amino-4-imidazole carboxamide (AICA) also reduced HOCl and attenuated the electrolysis-induced cardiac injury. However, unlike the parent molecule acadesine, AICA was not protective in the isolated heart subjected to ischemia and reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)","pmid":"8394912","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/8394912/"},{"id":3053,"title":"Chemical disinfection of duck hepatitis B virus: a model for inactivation of infectivity of hepatitis B virus.","authors":"Tsiquaye, K N; Barnard, J","year":1993,"date":"1993 Aug","journal":"The Journal of antimicrobial chemotherapy","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The susceptibility of duck hepatitis B virus (DHBV) to the virucidal effects of sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) was compared to hepatitis B virus (HBV) with the aim of using the duck as a model for studying HBV disinfection. Using viral DNA polymerase (DNAP) as a target, inhibition of DNAP activity by chlorine disinfectants was found to be concentration-dependent but independent of contact time. Two minute exposure of minimal effective concentrations of sodium hypochlorite (domestic bleach: 3600 ppm and industrial bleach: 3180 ppm) and sodium dichloroisocyanurate (3000 ppm available chlorine) to DHBV- and HBV-rich plasma totally inhibited DNA polymerase activity. DHBV particles in DHBV-carrier duck plasma (10(4.5) ID50/mL) were treated with these concentrations and inoculated intravenously into 18 one-day old ducklings (six animals/disinfectant). Analysis of plasma (0, 7 and 14 days post-infection) and post-mortem liver (14 days post-infection) by DNA hybridization techniques showed that DHBV DNA was undetectable in samples from all animals inoculated with disinfected virus particles. However, post-inoculation plasma and liver of 18 of 18 control ducklings inoculated with untreated virions were positive for DHBV DNA. These results show for the first time that total inhibition in vitro of hepadnavirus DNA polymerase activity by chemical disinfectants is predictive of inactivation of infectivity in vivo.","pmid":"8226434","doi":"10.1093/jac/32.2.313","url":"https://pubmed.ncbi.nlm.nih.gov/8226434/"},{"id":3056,"title":"Postischemic dysfunction of the heart induced by small numbers of neutrophils via formation of hypochlorous acid.","authors":"Raschke, P; Becker, B F; Leipert, B; Schwartz, L M; Zahler, S; Gerlach, E","year":1993,"date":"1993 Jul-Aug","journal":"Basic research in cardiology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The role of polymorphonuclear neutrophils (PMN) in the injury of the heart following ischemia and reperfusion is still controversial. The aim of this study was to investigate whether small numbers of PMN may cause myocardial dysfunction in an isolated system, how the resulting loss of function can be characterized and whether the formation of hypochlorous acid (HOCl) can be responsible for the PMN-mediated effect. Isolated working guinea pig hearts were subjected to a 90% reduction of coronary flow for 30 min, with or without intracoronary infusion of homologous PMN (approximately 1-2 x 10(5) cells/min, i.e. about 5-10% of normal blood count). This ischemia was followed by a 15 min reflow period in a non-working (\"Langendorff\") mode before work was resumed. In hearts perfused only with buffer, post-hypoxic heart function recovered to 75-80% of the initial value. Inclusion of unstimulated PMN did not further attenuate cardiac function. However, cardiac output was decreased to 42% of the initial value, provided thrombin (0.3 U/ml) and H2O2 (10(-5) M) were also present, and the retained PMN (about 10% of those infused) were additionally stimulated during reflow by application of FMLP (10(-6) M for 1 min). In these instances, coronary flow at any time of the experiment and release of lactate or purines during ischemia and reflow did not differ significantly between hearts perfused with or without PMN. There was no substantial release of myoglobin in controls and in PMN-treated hearts. Inotropic stimulation of the hearts with noradrenaline or exogenous Ca2+ caused a sustained increase in contractile force. However, the response was significantly reduced in PMN-perfused hearts in comparison to control hearts. The myocardial contents of high-energy phosphates with and without inotropic stimulation proved to be identical irrespective of whether experiments had been performed in the absence or presence of PMN. A similar loss of myocardial function as mediated by PMN could be produced by infusing chemically generated hypochlorous acid (HOCl, 5 x 10(-7) M for 10 min). Strikingly, that portion of the infused HOCl which actually reacted with cardiac tissue was comparable to the amount shown to be generated by stimulating 10(6) PMN retained in the coronary system (about 7 nmoles). Supplementing the perfusate with the scavengers L-methionine (10(-4) M) or uric acid (5 x 10(-4) M) prevented the attenuation of heart function provoked by PMN. The results indicate that small numbers of PMN, sufficiently activated, can depress cardiac function after 30 min of ischemia.(ABSTRACT TRUNCATED AT 400 WORDS)","pmid":"8240225","doi":"10.1007/BF00800639","url":"https://pubmed.ncbi.nlm.nih.gov/8240225/"},{"id":3060,"title":"Oxidation of desferrioxamine to nitroxide free radical by activated human neutrophils.","authors":"Soriani, M; Mazzuca, S; Quaresima, V; Minetti, M","year":1993,"date":"1993 Jun","journal":"Free radical biology & medicine","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Human neutrophils activated by PMA were found to induce the formation of a nitroxide radical from DFO. The presence of SOD was necessary to permit the formation of the DFO radical. The inactive phorbol ester did not induce DFO radical, and DL-sphinganine suppressed the radical produced by the active phorbol ester. Other cell stimuli (Zymocel and the chemotactic peptide) also induced the formation of the DFO radical, although radical concentration was very much lower than with PMA. Participation of NO, OH or 1O2 was ruled out by the inability of NG-methyl-L-arginine, NG-nitro-L-arginine, DMSO, mannitol, histidine, and methionine to inhibit the formation of DFO radical produced by PMA-activated cells. Furthermore, PMA-activated cells did not produce detectable levels of NO2-, a stable oxidation product of NO, and D2O, which enhances the lifetime of singlet oxygen, did not modify the intensity or the lifetime of DFO radical. The involvement of cell MPO was suggested by the inhibition of the DFO radical observed after treatment with catalase or with antihuman MPO antibodies. Also, HOCl was found to induce the DFO radical in cell-free reactions, but our data indicate that the reaction leading to DFO radical formation by neutrophils involves the reduction of MPO compound II back to the active enzyme (ferric-MPO). Anti-inflammatory drugs strongly increased the DFO radical produced by activated neutrophils. On the contrary, none of these drugs was able to increase the DFO radical produced by HOCl. Histidine and methionine that inhibited the DFO radical intensity in cell-free reactions, were shown to act directly on HOCl. Experiments with MPO-H2O2 in SOD- and Cl(-)-free conditions showed the formation of DFO radical and confirmed the hypothesis of the involvement of compound II. The conversion of compound II to ferric MPO by DFO optimized the enzymatic activity of neutrophils, and in the presence of monochlorodimedon (compound II promoting agent) we measured an increased HOCl production. When DFO was modified by conjugation with hydroxyethyl starch, it lost the ability to produce the radical either by neutrophils or by MPO-H2O2 and did not increase HOCl production. The inability of these DFO derivatives to produce potentially toxic species might explain their reported lower toxicity in vivo.","pmid":"7686874","doi":"10.1016/0891-5849(93)90140-p","url":"https://pubmed.ncbi.nlm.nih.gov/7686874/"},{"id":3063,"title":"Neopterin modulates toxicity mediated by reactive oxygen and chloride species.","authors":"Weiss, G; Fuchs, D; Hausen, A; Reibnegger, G; Werner, E R; Werner-Felmayer, G; Semenitz, E; Dierich, M P; Wachter, H","year":1993,"date":"1993 Apr 19","journal":"FEBS letters","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Neopterin, a pyrazino-pyrimidine derivative, is synthesized in excess by human monocytes/macrophages upon stimulation with interferon-gamma, a cytokine derived from activated I cells. Neopterin is furthermore produced constitutively. A relatively constant ratio between neopterin and its reduced form. 7,8-dihydroneopterin, has been described in human serum. In the study presented here we tested the ability of neopterin and its reduced form to modulate the effects of cytotoxic substances like hydrogen peroxide or hypochlorous acid and N-chloramine derivatives. We show that 7,8-dihydroneopterin potently reduces biological and chemical effects of these substances independently from the pH value. In contrast, at slightly alkaline pH (pH 7.5) neopterin enhances hydrogen peroxide and chloramine-T activity. This is demonstrated by increase of signal intensity in a luminol assay and also by enhancement of toxicity towards bacteria. Thus, the macrophage derived substance neopterin is able both to enhance and to reduce cytotoxicity in dependence of pH value and its oxidation state, and it may have a pivotal role in modulation of macrophage mediated effector mechanism.","pmid":"8385632","doi":"10.1016/0014-5793(93)80627-7","url":"https://pubmed.ncbi.nlm.nih.gov/8385632/"},{"id":3064,"title":"A direct viable count method for the enumeration of attached bacteria and assessment of biofilm disinfection.","authors":"Yu, F P; Pyle, B H; McFeters, G A","year":1993,"date":"1993 Apr","journal":"Journal of microbiological methods","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"This report describes the adaptation of an in situ direct viable count (in situ DVC) method in biofilm disinfection studies. The results obtained with this technique were compared to two other enumeration methods, the plate count (PC) and conventional direct viable count (c-DVC). An environmental isolate (Klebsiella pneumoniae Kp1) was used to form biofilms on stainless steel coupons in a stirred batch reactor. The in situ DVC method was applied to directly assess the viability of bacteria in biofilms without disturbing the integrity of the interfacial community. As additional advantages, the results were observed after 4 h instead of the 24 h incubation time required for colony formation and total cell numbers that remained on the substratum were enumerated. Chlorine and monochloramine were used to determine the susceptibilities of attached and planktonic bacteria to disinfection treatment using this novel analytical approach. The planktonic cells in the reactor showed no significant change in susceptibility to disinfectants during the period of biofilm formation. In addition, the attached cells did not reveal any more resistance to disinfection than planktonic cells. The disinfection studies of young biofilms indicated that 0.25 mg/l free chlorine (at pH 7.2) and 1 mg/l monochloramine (at pH 9.0) have comparable disinfection efficiencies at 25 degrees C. Although being a weaker disinfectant, monochloramine was more effective in removing attached bacteria from the substratum than free chlorine. The in situ DVC method always showed at least one log higher viable cell densities than the PC method, suggesting that the in situ DVC method is more efficient in the enumeration of biofilm bacteria. The results also indicated that the in situ DVC method can provide more accurate information regarding the cell numbers and viability of bacteria within biofilms following disinfection.","pmid":"11537721","doi":"10.1016/0167-7012(93)90044-i","url":"https://pubmed.ncbi.nlm.nih.gov/11537721/"},{"id":3066,"title":"Carbamazepine metabolism to a reactive intermediate by the myeloperoxidase system of activated neutrophils.","authors":"Furst, S M; Uetrecht, J P","year":1993,"date":"1993 Mar 24","journal":"Biochemical pharmacology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Carbamazepine is an anticonvulsant which is associated with a significant incidence of hypersensitivity reactions including agranulocytosis. We have postulated that many drug hypersensitivity reactions, especially agranulocytosis and lupus, are due to reactive metabolites generated by the myeloperoxidase (MPO) (EC 1.11.1.7) system of neutrophils and monocytes. This led to a study of the metabolism and covalent binding of carbamazepine with MPO/H2O2/Cl- and neutrophils. Metabolism and covalent binding were observed in both systems and the same pathway appeared to be involved; however, the metabolism observed with the MPO system was approximately 500-fold greater than that observed with neutrophils. The metabolites identified were an intermediate aldehyde, 9-acridine carboxaldehyde, acridine, acridone, choloroacridone, and dichloroacridone. We postulate that the first intermediate in the metabolism of carbamazepine is a carbonium ion formed by reaction of hypochlorous acid (HOCl) with the 10,11 double bond. Although we have no direct proof for the proposed carbonium ion, it provides the most likely mechanism for the observed ring contraction. Iminostilbene, a known metabolite of carbamazepine, was also metabolized by a similar pathway leading to ring contraction; however, the rate was much faster and the first step may involve N-chlorination and a nitrenium ion intermediate. These data confirm that carbamazepine is metabolized to reactive intermediates by activated leukocytes. Such metabolites could be responsible for some of the adverse reactions associated with carbamazepine, especially reactions such as agranulocytosis and lupus which involve leukocytes.","pmid":"8385460","doi":"10.1016/0006-2952(93)90279-6","url":"https://pubmed.ncbi.nlm.nih.gov/8385460/"},{"id":3070,"title":"Antioxidant protection against hypochlorous acid in human plasma.","authors":"Hu, M L; Louie, S; Cross, C E; Motchnik, P; Halliwell, B","year":1993,"date":"1993 Feb","journal":"The Journal of laboratory and clinical medicine","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid (HOCI) is a powerful oxidizing and chlorinating agent produced by the neutrophil enzyme myeloperoxidase. The antioxidant defenses of freshly prepared human plasma against HOCI/OCI- were explored. Addition of HOCI/OCI- to plasma caused rapid oxidation of ascorbic acid and thiol (-SH) groups but not of uric acid. Plasma -SH groups (which are known to be largely located on albumin) were quantitatively the most important scavenger of HOCI/OCI-, but adding extra ascorbate to plasma caused this molecule to have a more important scavenging role against HOCI/OCI-. Added HOCI/OCI- produced no detectable lipid peroxidation in plasma or depletion of lipid-soluble antioxidants (alpha-tocopherol or ubiquinol-10). No evidence of oxidative damage to protein amino acid residues (other than -SH) was detected by the carbonyl assay. It seems that -SH groups are a major target of attack by HOCI/OCI- in vivo, and plasma albumin may be an important protective antioxidant. Ascorbic acid might also play a protective role, especially in individuals supplemented with this vitamin. Ascorbate might also be important in extracellular fluids with low albumin concentrations such as synovial, respiratory tract lining, and cerebrospinal fluids.","pmid":"8381845","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/8381845/"},{"id":3076,"title":"[Javelle water and drinking water].","authors":"Jacquet, F","year":1993,"date":"1993","journal":"Bulletin de la Societe de pathologie exotique (1990)","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Because of its exceptional disinfecting properties, hypochlorite bleach is, along with vaccines and antibiotics, an outstanding tool in the prevention of water-borne infectious diseases such as cholera, and especially in tropical environments. In addition, hypochlorite bleach is available around the world, and at low cost. Moreover, hypochlorite bleach is safe for human when used as directed. It is also sale for the environment in household use. In the Public Health domain, hypochlorite bleach with its 200-year history remains both a modern product and a product of the future.","pmid":"7819808","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/7819808/"},{"id":3077,"title":"Evaluation of the antioxidant actions of ferulic acid and catechins.","authors":"Scott, B C; Butler, J; Halliwell, B; Aruoma, O I","year":1993,"date":"1993","journal":"Free radical research communications","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"We have evaluated the abilities of ferulic acid, (+/-) catechin, (+) catechin and (-) epicatechin to scavenge the reactive oxygen species hydroxyl radical (OH.), hypochlorous acid (HOCl) and peroxyl radicals (RO2.). Ferulic acid tested at concentrations up to 5 mM inhibited the peroxidation of phospholipid liposomes. Both (+/-) and (+) catechin and (-) epicatechin were much more effective. All the compounds tested reacted with trichloromethyl peroxyl radical (CCl3 O2.) with rate constants > 1 x 10(6) M-1 s-1. A mixture of FeCl3-EDTA, hydrogen peroxide (H2O2) and ascorbic acid at pH 7.4, has often been used to generate hydroxyl radicals (OH.) which are detected by their ability to cause damage to the sugar deoxyribose. Ferulic acid, (+) and (+/-) catechin and (-) epicatechin inhibited deoxyribose damage by reacting with OH. with rate constants of 4.5 x 10(9)M-1 s-1, 3.65 x 10(9) M-1 s-1, 2.36 x 10(9) M-1 s-1 and 2.84 x 10(9) M-1 s-1 respectively. (-) Epicatechin, ferulic acid and the (+) and (+/-) catechins exerted pro-oxidant action, accelerating damage to DNA in the presence of a bleomycin-iron complex. On a molar basis, ferulic acid was less effective in causing damage to DNA compared with the catechins. A mixture of hypoxanthine and xanthine oxidase generates O2-. which reduces cytochrome c to ferrocytochrome c. (+) Catechin and (-) epicatechin inhibited the reduction of cytochrome c in a concentration dependent manner. Ferulic acid and (+/-) catechin had only weak effects. All the compounds tested were able to scavenge hypochlorous acid at a rate sufficient to protect alpha-1-antiproteinase against inactivation. Our results show that catechins and ferulic acid possess antioxidant properties. This may become important given the current search for \"natural\" replacements for synthetic antioxidant food additives.","pmid":"7507456","doi":"10.3109/10715769309056512","url":"https://pubmed.ncbi.nlm.nih.gov/7507456/"},{"id":3086,"title":"[Characteristics of chloramine complexes of carnosine with hypochlorite anion].","authors":"Formaziuk, V E; Gorshkova, T Iu; Boldyrev, A A; Sergienko, V I","year":1992,"date":"1992 Sep","journal":"Biokhimiia (Moscow, Russia)","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Carnosine interaction with CIO results in the formation of a stable chloramine complex. The binding of the whole bulk of hypochlorite to carnosine is completed within one minute of incubation. During subsequent 2-hour incubation no more than 15% of the chloramine complex is destroyed; this property of carnosine makes it similar to taurine. Unlike histidine and beta-alanine, glutathione rapidly interacts with hypochlorite. However, in contrast with these compounds and carnosine, glutathione does not form stable chloramine complexes with CIO. The putative role of myeloperoxidase in the development of senile human lens opacities is discussed.","pmid":"1334704","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/1334704/"},{"id":3087,"title":"Polymicrobial sepsis disrupts normal neutrophil extracellular matrix protein interactions.","authors":"Simms, H H; D'Amico, R","year":1992,"date":"1992 Sep","journal":"Circulatory shock","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The purpose of this study was to examine how intra-abdominal sepsis and extracellular matrix proteins (fibronectin, laminin) affect adherent polymorphonuclear leukocyte (PMN) function. Two groups of swine were studied: Group I (n = 5) underwent sham laparotomy; Group II (n = 8) underwent cecal ligation and incision. PMN adherent to either fibronectin (F) or laminin (L) had increased candicidal activity over buffer (B) by Group I but not by post-operative day 8 Group II PMN. (Percent specific release 51Cr-Group I--35.00, 68.25, 64.75% for B, F, and L; P less than 0.001 comparing B vs. F or L; Group II--14.25, 12.50, 12.75% for B, F, and L; P = NS comparing B vs. F or L.) To determine the mechanism for this finding, PMN priming was then assessed by evaluating both PMN adherence to extracellular matrix proteins and the cell surface expression of CR1/CR3 by using sheep RBC opsonized with C3b or C3bi. PMN activation was assayed by using MTT-Formazan, myeloperoxidase, and hypochlorous acid (HOCl) production. Fibronectin and laminin increased PMN adherence and CR1/CR3 expression over buffer by Group I and Group II animals. Fibronectin and laminin increased MTT-Formazan, myeloperoxidase, and HOCl production over buffer by Group I PMN but not POD 8 Group II PMN. These results suggest that untreated intra-abdominal sepsis partially abrogates the effect of extracellular matrix proteins on PMN function; in particular, the activation but not priming of adherent PMN by extracellular matrix proteins is reduced in this clinical situation.","pmid":"1327574","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/1327574/"},{"id":3088,"title":"Neutral endopeptidase of a human airway epithelial cell line recovers after hypochlorous acid exposure: dexamethasone accelerates this by stimulating neutral endopeptidase mRNA synthesis.","authors":"Lang, Z; Murlas, C G","year":1992,"date":"1992 Sep","journal":"American journal of respiratory cell and molecular biology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypocholorous acid (HOCl) exposure of Calu-1 cells in situ leads to a relatively rapid and substantial decrease in whole cell neutral endopeptidase (NEP) activity that may result from the internalization of NEP from plasma membrane surfaces. To confirm this, and to assess the time course of changes in cell NEP after oxidant exposure and the potential influence of corticosteroid treatment on these, we evaluated Calu-1 NEP activity by high performance liquid chromatography and NEP-specific mRNA over the ensuing 48 h after HOCl in the presence or absence of 1 microM dexamethasone. Cells, grown to confluency in Dulbecco's modified Eagle's medium with 10% fetal bovine serum, were exposed for 5 min to 100 microM HOCl and then maintained in culture for 48 h thereafter. Before exposure, some cell plates were cooled to 4 degrees C and/or incubated for 5 min in 1 mM sodium azide. In some experiments, post-HOCl changes in NEP-specific mRNA in the presence or absence of dexamethasone were also evaluated using Northern blot analysis. We found that sodium azide at 4 degrees C totally blocked the effect of HOCl on Calu-1 NEP (n = 6). In the absence of sodium azide, NEP activity spontaneously recovered to preexposure levels within 24 h. This recovery occurred 6 h earlier in the presence of 1 microM dexamethasone. Furthermore, dexamethasone increased NEP activity at 24 and 48 h after HOCl. Northern blot analysis indicated that NEP-specific mRNA did not change during spontaneous recovery, but was increased by dexamethasone 24 h after HOCl.(ABSTRACT TRUNCATED AT 250 WORDS)","pmid":"1325811","doi":"10.1165/ajrcmb/7.3.300","url":"https://pubmed.ncbi.nlm.nih.gov/1325811/"},{"id":3089,"title":"Chlorohydrin formation from unsaturated fatty acids reacted with hypochlorous acid.","authors":"Winterbourn, C C; van den Berg, J J; Roitman, E; Kuypers, F A","year":1992,"date":"1992 Aug 1","journal":"Archives of biochemistry and biophysics","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Stimulated neutrophils produce hypochlorous acid (HOCl) via the myeloperoxidase-catalyzed reaction of hydrogen peroxide with chloride. The reactions of HOCl with oleic, linoleic, and arachidonic acids both as free fatty acids or bound in phosphatidylcholine have been studied. The products were identified by gas chromatography-mass spectrometry of the methylated and trimethylsilylated derivatives. Oleic acid was converted to the two 9,10-chlorohydrin isomers in near stoichiometric yield. Linoleic acid, at low HOCl:fatty acid ratios, yielded predominantly a mixture of the four possible monochlorohydrin isomers. Bischlorohydrins were also formed, in increasing amounts at higher HOCl concentrations. Arachidonic acid gave a complex mixture of mono- and bischlorohydrins, the relative proportions depending on the amount of HOCl added. Linoleic acid appears to be slightly more reactive than oleic acid with HOCl. Reactions of oleic and linoleic acids with myeloperoxidase, hydrogen peroxide, and chloride gave chlorohydrin products identical to those with HOCl. Lipid chlorohydrins have received little attention as products of reactions of neutrophil oxidants. They are more polar than the parent fatty acids, and if formed in cell membranes could cause disruption to membrane structure. Since cellular targets for HOCl appear to be membrane constituents, chlorohydrin formation from unsaturated lipids could be significant in neutrophil-mediated cytotoxicity.","pmid":"1321589","doi":"10.1016/0003-9861(92)90609-z","url":"https://pubmed.ncbi.nlm.nih.gov/1321589/"},{"id":3095,"title":"[Oxidative modification and inactivation of superoxide dismutase by hypochlorite].","authors":"Sharonov, B P; Churilova, I V","year":1992,"date":"1992 May","journal":"Biokhimiia (Moscow, Russia)","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The inactivating effect of hypochlorite on Cu, Zn-superoxide dismutase (SOD) from bovine erythrocytes has been studied. According to SDS gel electrophoresis and isoelectric focusing data, oxidation is associated with the degradation of the polypeptide chain, formation of aggregates, and appearance of new isoforms. These protein fractions differ from native SOD by the electric charge and molecular mass but possess a catalytic activity. Modified SOD isoforms occur as a result of intramolecular crosslinking of amino groups and aldehydes which is confirmed by the appearance of fluorescence maxima in the longwave region characteristic of such links. It is assumed that the mechanism of SOD inactivation is coupled to the oxidation of amino acids located outside the active center of the enzyme.","pmid":"1322195","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/1322195/"},{"id":3104,"title":"Different effects of hypochlorous acid on human neutrophil metalloproteinases: activation of collagenase and inactivation of collagenase and gelatinase.","authors":"Michaelis, J; Vissers, M C; Winterbourn, C C","year":1992,"date":"1992 Feb 1","journal":"Archives of biochemistry and biophysics","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Human neutrophils stimulated with phorbol 12-myristate 13-acetate (PMA) produce the reactive oxidant hypochlorous acid (HOCl) and release the matrix metalloproteinases collagenase and gelatinase from secretory granules. We have investigated the stoichiometry of activation and inactivation of the two metalloproteinases with HOCl. HOCl activated purified neutrophil procollagenase at ratios between 10 and 40 mol of HOCl/mol enzyme, but caused inactivation at higher ratios. Maximum activation was about the same as that achieved by p-aminophenyl-mercuric acetate. However, less than a third of the total collagenase released from PMA-stimulated neutrophils was activated by coreleased HOCl and most of the activity was destroyed after 1 h of stimulation. These results indicate that the HOCl/enzyme ratio must fall within a narrow range for activation to occur. In contrast to collagenase, purified progelatinase underwent negligible activation (2.5 +/- 1.2%) at HOCl/enzyme molar ratios less than 30 and was destroyed at higher ratios. Likewise no active gelatinase could be detected in supernatant from PMA-stimulated cells and almost all of the proenzyme was destroyed by HOCl after 60 min stimulation. Our results illustrate that only collagenase can be activated by HOCl in vitro and that gelatinase is much more sensitive to inactivation. Since a precise HOCl/enzyme ratio is required for collagenase activation it is doubtful whether effective enzyme regulation by HOCl could occur in vivo where various HOCl scavengers are present.","pmid":"1309976","doi":"10.1016/0003-9861(92)90030-z","url":"https://pubmed.ncbi.nlm.nih.gov/1309976/"},{"id":3105,"title":"Defining the involvement of HOCl or Cl2 as enzyme-generated intermediates in chloroperoxidase-catalyzed reactions.","authors":"Libby, R D; Shedd, A L; Phipps, A K; Beachy, T M; Gerstberger, S M","year":1992,"date":"1992 Jan 25","journal":"The Journal of biological chemistry","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Peroxidatic substrates, catechol (CAT) and 2,4,6-trimethylphenol (TMP) were used as probes of thechloride dependent reactions catalyzed by chloroperoxidase (CPO). TMP is consumed only in the presence of chloride. TMP is a competitive inhibitor versus CAT, but CAT is a noncompetitive inhibitor versus TMP in chloride-dependent CPO-catalyzed peroxidation reactions. The ratio of TMP versus CAT consumed by the chloride-dependent CPO reaction in direct competition studies increases as the chloride concentration is increased from 1.0 to 400 mM. Ratios of non-enzymatic HOCl reactions under conditions otherwise similar to those of the CPO reactions are relatively insensitive to changes in chloride concentration and are experimentally indistinguishable from the values attained by the enzyme system at high chloride concentrations. Comparison of enzymatic ratios with those of the HOCl reactions indicate that the proportion of the enzymatic reaction involving a freely dissociable, enzyme-generated, oxidized halogen species varies from 10% at low chloride concentrations to essentially 100% at high chloride concentrations. All data are consistent with a mechanism in which chloride competes with CAT for binding to both CPO compound I and the CPO chlorinating intermediate (EOCl). Chloride binding to CPO compound I leads to the formation of EOCl and initiates the CPO chloride-dependent pathway. When CAT binds to either compound I or EOCl, it is directly oxidized to product. When chloride binds to EOCl, it either induces release of HOCl or reacts with EOCl to produce Cl2, which is released from the enzyme. TMP and CAT compete for reaction with the free oxidized halogen species. This is the first direct evidence for kinetically significant involvement of a free oxidized halogen species as an intermediate in any CPO-catalyzed reaction.","pmid":"1309797","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/1309797/"},{"id":3111,"title":"Hypochlorous acid and myeloperoxidase-catalyzed oxidation of iron-sulfur clusters in bacterial respiratory dehydrogenases.","authors":"Hurst, J K; Barrette, W C Jr; Michel, B R; Rosen, H","year":1991,"date":"1991 Dec 18","journal":"European journal of biochemistry","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Hypochlorous acid and related oxidants derived from myeloperoxidase-catalyzed reactions contribute to the microbicidal activities of phagocytosing neutrophils and monocytes. Microbial iron-sulfur (Fe/S) clusters have been suggested as general targets of myeloperoxidase-derived oxidations, but no susceptible Fe/S site has yet been identified. In this study, the effects of HOCl and myeloperoxidase-catalyzed peroxidation of chloride ion upon EPR-detectable Fe/S clusters in Escherichia coli and Pseudomonas aeruginosa were examined. Increasing amounts of oxidant produced progressive loss of signal amplitudes from the S-1 and S-3 Fe/S clusters of succinate:ubiquinone oxidoreductase in respiring membrane fragments. These changes were compared to loss of microbial viability, succinate uptake rates, succinate dehydrogenase activity and succinate-dependent respiration. The amounts of oxidant required to destroy Fe/S clusters exceeded the amounts required to kill organisms or inhibit respiratory function by factors of four or five. Power saturation characteristics of the S-1 signal indicated that the S-2 signal was also resistant to modification, even in highly oxidized membranes. Loss of succinate-dependent respiration was closely associated with HOCl and myeloperoxidase-mediated microbicidal activity against P. aeruginosa and was also an early event in the oxidant-mediated metabolic dysfunctions of E. coli. However, these effects were not caused by the destruction of the Fe/S clusters within the succinate:ubiquinone oxidoreductase. Rather, the major respiration-inhibiting lesion(s) appeared to reside at points in the respiratory chain between the Fe/S clusters and the ubiquinone reductase site.","pmid":"1662610","doi":"10.1111/j.1432-1033.1991.tb16500.x","url":"https://pubmed.ncbi.nlm.nih.gov/1662610/"},{"id":3115,"title":"Hypochlorous acid mobilizes cellular zinc.","authors":"Fliss, H; Ménard, M; Desai, M","year":1991,"date":"1991 Nov","journal":"Canadian journal of physiology and pharmacology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Neutrophil oxidants, in particular hypochlorous acid (HOCl), can cause injury to healthy tissues at sites of inflammation. Some of this injury may be caused by oxidant-induced mobilization of metals. We examined the ability of HOCl to mobilize Zn2+ in target tissues. Arterial endothelial cell cultures and heart tissue sections were incubated for 90 s in buffered saline, pH 7.3, containing a suspension of N-(6-methoxy-8-quinolyl)-p-toluenesulfonamide (100 nmol/mL), a Zn(2+)-specific fluorescent chelator, and were subsequently exposed to 200 microM HOCl for 5 min. The cellular fluorescence was analyzed histologically and showed a marked increase in intensity after HOCl treatment, which was indicative of an increase in cellular free Zn2+ concentration. Incubation of HOCl-treated tissues with dithiothreitol, a membrane-permeable metal chelator, caused a sharp decline in cellular fluorescence. This study shows for the first time that HOCl can mobilize cellular Zn2+. In view of the multiple cellular roles played by Zn2+, its mobilization by oxidants at sites of inflammation may contribute to the observed injury. The ability of dithiothreitol to chelate the mobilized Zn2+ suggests that it may be able to reverse Zn(2+)-mediated injury.","pmid":"1666536","doi":"10.1139/y91-250","url":"https://pubmed.ncbi.nlm.nih.gov/1666536/"},{"id":3120,"title":"Pseudomonas and neutrophil products modify transferrin and lactoferrin to create conditions that favor hydroxyl radical formation.","authors":"Britigan, B E; Edeker, B L","year":1991,"date":"1991 Oct","journal":"The Journal of clinical investigation","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"In vivo most extracellular iron is bound to transferrin or lactoferrin in such a way as to be unable to catalyze the formation of hydroxyl radical from superoxide (.O2-) and hydrogen peroxide (H2O2). At sites of Pseudomonas aeruginosa infection bacterial and neutrophil products could possibly modify transferrin and/or lactoferrin forming catalytic iron complexes. To examine this possibility, diferrictransferrin and diferriclactoferrin which had been incubated with pseudomonas elastase, pseudomonas alkaline protease, human neutrophil elastase, trypsin, or the myeloperoxidase product HOCl were added to a hypoxanthine/xanthine oxidase .O2-/H2O2 generating system. Hydroxyl radical formation was only detected with pseudomonas elastase treated diferrictransferrin and, to a much lesser extent, diferriclactoferrin. This effect was enhanced by the combination of pseudomonas elastase with other proteases, most prominently neutrophil elastase. Addition of pseudomonas elastase-treated diferrictransferrin to stimulated neutrophils also resulted in hydroxyl radical generation. Incubation of pseudomonas elastase with transferrin which had been selectively iron loaded at either the NH2- or COOH-terminal binding site yielded iron chelates with similar efficacy for hydroxyl radical catalysis. Pseudomonas elastase and HOCl treatment also decreased the ability of apotransferrin to inhibit hydroxyl radical formation by a Fe-NTA supplemented hypoxanthine/xanthine oxidase system. However, apotransferrin could be protected from the effects of HOCl if bicarbonate anion was present during the incubation. Apolactoferrin inhibition of hydroxyl radical generation was unaffected by any of the four proteases or HOCl. Alteration of transferrin by enzymes and oxidants present at sites of pseudomonas and other bacterial infections may increase the potential for local hydroxyl radical generation thereby contributing to tissue injury.","pmid":"1655825","doi":"10.1172/JCI115408","url":"https://pubmed.ncbi.nlm.nih.gov/1655825/"},{"id":3122,"title":"N6-adenyl arylation of DNA by aristolochic acid II and a synthetic model for the putative proximate carcinogen.","authors":"Pfau, W; Schmeiser, H H; Wiessler, M","year":1991,"date":"1991 Sep-Oct","journal":"Chemical research in toxicology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Aristolochic acid II (AAII), one of the major components of the carcinogenic plant extract aristolochic acid, is known to be mutagenic and to form DNA adducts in vitro and in vivo. The major fluorescent DNA adduct formed upon xanthine oxidase mediated reduction in the presence of calf thymus (CT-) DNA or deoxyadenosine was isolated by means of preparative HPLC and identified by fluorescence, UV/vis absorbance, and 1H NMR spectroscopy as 7-(deoxy-adenosin-N6-yl)aristolactam II. As a model proximate carcinogen, N-chloroaristolactam II was prepared chemically from aristolactam II, the reduction product of AAII. This model compound was spectroscopically characterized and found to react directly with CT-DNA without any activation, forming the same deoxyadenosine adduct. HPLC analysis with fluorescence monitoring detected this adduct in vivo in the liver DNA of Wistar rats treated orally with AAII. These results confirm the anticipated metabolic activation mechanism of AAII as occurring via a cyclic nitrenium ion.","pmid":"1665354","doi":"10.1021/tx00023a015","url":"https://pubmed.ncbi.nlm.nih.gov/1665354/"},{"id":3125,"title":"Potential of animal myeloperoxidase to protect plants from pathogens.","authors":"Jacks, T J; Cotty, P J; Hinojosa, O","year":1991,"date":"1991 Aug 15","journal":"Biochemical and biophysical research communications","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The effect of animal myeloperoxidase (EC 1.11.1.7) on the viability of a plant pathogen was determined. Lethality of hydrogen peroxide to germinating spores of Aspergillus flavus increased 90-fold enzymically. Singlet oxygen was present but hypochlorite accounted for two-thirds of the increase. The results indicate myeloperoxidase could improve microbial resistance in plants, perhaps transgenically.","pmid":"1651715","doi":"10.1016/0006-291x(91)91020-d","url":"https://pubmed.ncbi.nlm.nih.gov/1651715/"},{"id":3127,"title":"Effect of tumor necrosis factor on the generation of chlorinated oxidants by adherent human neutrophils.","authors":"Test, S T","year":1991,"date":"1991 Aug","journal":"Journal of leukocyte biology","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Human neutrophils adherent to simulated biologic surfaces undergo significant activation of the respiratory burst over prolonged periods of time in response to stimulation with the cytokines tumor necrosis factor-alpha (TNF alpha) or tumor necrosis factor-beta (TNF beta) or with the chemotactic peptide N-formyl-methionylleucylphenylalanine (FMLP). In this study, neutrophils were examined for their ability to generate the highly reactive and powerful oxidant hypochlorous acid (HOCl) and the longer-lived, less reactive endogenous nitrogen-chlorine (N-Cl) derivatives in response to these stimuli either alone or when exposed to recombinant human TNF alpha (rTNF alpha) or beta (rTNF beta) prior to addition of FMLP. Neutrophils adherent to fetal bovine serum-coated polystyrene tissue culture wells were able to generate only small quantities of HOCl when incubated with rTNF alpha, rTNF beta, or FMLP individually. However, when neutrophils were first incubated with either rTNF alpha or rTNF beta prior to addition of FMLP, there was a marked increase in HOCl generation. Neutrophils stimulated in such a manner consumed approximately 18% of the HOCl generated in the formation of N-Cl derivatives. Further scrutiny of the response to the combination of rTNF alpha and FMLP revealed that HOCl release was rapid, with 80% of total HOCl accumulation occurring within 15 min after FMLP addition. The amount of HOCl generated was dependent on the number of cells added and on the concentration of both rTNF alpha and FMLP. Comparison of HOCl generation with superoxide anion and myeloperoxidase release showed that the amount of HOCl generated was limited primarily by the amount of myeloperoxidase released rather than by the degree of respiratory burst activation. These results demonstrate that human neutrophils stimulated with FMLP after a brief incubation with rTNF alpha or rTNF beta can generate cytotoxic and microbicidal concentrations of chlorinated oxidants.","pmid":"1649239","doi":"10.1002/jlb.50.2.131","url":"https://pubmed.ncbi.nlm.nih.gov/1649239/"},{"id":3132,"title":"Monochloramine induces contraction of guinea pig gallbladder via two different pathways.","authors":"Moummi, C; Gullikson, G W; Gaginella, T S","year":1991,"date":"1991 Jun","journal":"The American journal of physiology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"The purpose of the present investigation was to examine the effect and mechanism of action of the reactive oxygen metabolites monochloramine (NH2Cl), hypochlorous acid (HOCl), and hydrogen peroxide (H2O2) on gallbladder smooth muscle contractility. All oxidants caused concentration-dependent increases in resting tension of gallbladder muscle; the rank order of potencies (half-maximal concentration) was NH2Cl (30 microM) greater than HOCl (70 microM) greater than H2O2 (100 microM). The oxidant concentrations employed are those found to exist in inflamed tissue. Tetrodotoxin (0.5 microM) had no effect on gallbladder muscle contraction caused by the oxidants, suggesting a direct, nonneural action. The maximal response induced by NH2Cl, HOCl, or H2O2 was significantly (P less than 0.05) inhibited by 5 microM indomethacin and 5 microM piroxicam. The calcium channel blocker verapamil partially inhibited the contractile effect of NH2Cl but had no effect on the contraction induced by exogenous cyclooxygenase products. Monochloramine induced significant prostaglandin E2 release from the gallbladder, which was blocked by indomethacin. Furthermore, the effect of NH2Cl on the smooth muscle was blocked by 5-aminosalicylic acid (1 mM). We conclude that reactive oxygen metabolites induce contraction of gallbladder smooth muscle by a direct action. The effect is mediated via cyclooxygenase metabolites and activation of calcium influx.","pmid":"1647675","doi":"10.1152/ajpgi.1991.260.6.G881","url":"https://pubmed.ncbi.nlm.nih.gov/1647675/"},{"id":3139,"title":"An assessment of cleaning and sampling methods for food-contact surfaces in premises preparing and selling high-risk foods.","authors":"Tebbutt, G M","year":1991,"date":"1991 Apr","journal":"Epidemiology and infection","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"The performance of agar-contact plates and an alginate-swab method for sampling food surfaces before and after cleaning was compared. Contact plates were more convenient, and were at least as sensitive as the swabbing method. To assess cleaning efficiency repeated sampling was carried out in selected premises, and several cleaning methods were introduced for trial periods. Some surfaces, notably wood and polypropylene, were particularly difficult to clean. For these scrubbing with a nylon brush was the best method. Other surfaces were more easily cleaned, and generally the methods introduced as part of this study were better than the original method used in the premises. Paper proved to be unpopular, and cleaning solutions applied with it did no better than those cleaned with a multiuse cloth kept soaking in a detergent and hypochlorite solution.","pmid":"1850362","doi":"10.1017/s0950268800048470","url":"https://pubmed.ncbi.nlm.nih.gov/1850362/"},{"id":3140,"title":"Neutrophil-derived oxidants modify CCK-OP-stimulated guinea pig gallbladder contraction in vitro.","authors":"Moummi, C; Gullikson, G W; Grisham, M B; Gaginella, T S","year":1991,"date":"1991 Apr","journal":"The American journal of physiology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Neutrophil-derived oxidants such as hydrogen peroxide (H2O2), hypochlorous acid (HOCl), and monochloramine (NH2Cl) may contribute to gallbladder inflammation in cholecystitis. We examined the influence of oxidants on the biological activity of different agonists and antagonists of gallbladder smooth muscle function. The concentration-response curves for cholecystokinin-octapeptide (CCK-OP) and carbachol were examined before and after incubation of the tissues with NH2Cl (30 microM). The 50% effective concentration of CCK-OP was shifted from 0.5 +/- 0.09 nM (control) to 4 +/- 1.2 nM in the presence of NH2Cl. The effect of carbachol was not affected by NH2Cl. The contractile effect of CCK-OP (3 nM) was abolished by prior exposure to HOCl or NH2Cl. These actions were prevented by 60 microM glutathione. Oxidant-induced degradation of CCK-OP was confirmed by high-performance liquid chromatography and thin-layer chromatography. NH2Cl also significantly reduced the contractile response to neurokinin A, bradykinin, leukotriene D4, and phorbol 12,13-dibutyrate and the relaxant response to isoproterenol. Prior exposure of acetylcholine, histamine, serotonin, prostaglandin E2, vasoactive intestinal polypeptide, or calcitonin gene-related peptide to NH2Cl had no effect on their activity. The results indicate that NH2Cl generated during inflammation may decrease the biological activities of different agonists and antagonists of smooth muscle function.","pmid":"1850205","doi":"10.1152/ajpgi.1991.260.4.G571","url":"https://pubmed.ncbi.nlm.nih.gov/1850205/"},{"id":3142,"title":"Scavenging effect of 5-aminosalicylic acid on neutrophil-derived oxidants. Possible contribution to the mechanism of action in inflammatory bowel disease.","authors":"Tamai, H; Kachur, J F; Grisham, M B; Gaginella, T S","year":1991,"date":"1991 Mar 15-Apr 1","journal":"Biochemical pharmacology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Inflammatory phagocytic leukocytes produce superoxide and hydrogen peroxide and secrete myeloperoxidase (MPO) into the extracellular medium. MPO catalyzes the oxidation of Cl- by H2O2 to yield chlorinated oxidants (e.g. HOCl and NH2Cl), which have been shown to induce pathologic changes in mucosal function. We examined the ability of 5-aminosalicylic acid (5-ASA), a drug used to treat inflammatory bowel disease (IBD), to inhibit oxidation of L-cysteine by NH2Cl, HOCl and H2O2. NH2Cl and HOCl were especially strong oxidants against L-cysteine. 5-ASA prevented L-cysteine oxidation by NH2Cl and HOCl; an interaction associated with the formation of characteristic absorption spectra due to the oxidation of 5-ASA was observed. NH2Cl and HOCl evoked characteristic increases in short-circuit current (Isc), indicative of net electrolyte transport, when added to the serosal side of stripped rat colon mounted in Ussing chambers. Premixing of NH2Cl with 5-ASA 10 min before addition to the tissue markedly reduced the secretory response to NH2Cl. In contrast, 5-ASA immediately reduced the response to HOCl. The reduction in the functional response to NH2Cl and HOCl by 5-ASA may contribute to its mechanism of action in the treatment of the symptoms of IBD.","pmid":"1848973","doi":"10.1016/0006-2952(91)90207-l","url":"https://pubmed.ncbi.nlm.nih.gov/1848973/"},{"id":3143,"title":"Nucleotide chloramines and neutrophil-mediated cytotoxicity.","authors":"Bernofsky, C","year":1991,"date":"1991 Mar 1","journal":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","category":"Human clinical & healthcare","evidence":"Review","relevance":"Medium","abstract":"Hypochlorite is a reactive oxidant formed as an end product of the respiratory burst in activated neutrophils. It is responsible for killing bacteria and has been implicated in neutrophil-mediated tissue injury associated with the inflammatory process. Although hypochlorite is a potent cytotoxic agent, the primary mechanism by which it exerts its effect is unclear. This review examines evidence that the primary event in hypochlorite cytotoxicity is the loss of adenine nucleotides from the target cell. This loss appears to be mediated by the formation of adenine nucleotide chloramines which are reactive intermediates with a free radical character and are capable of forming stable ligands with proteins and nucleic acids.","pmid":"1848195","doi":"10.1096/fasebj.5.3.1848195","url":"https://pubmed.ncbi.nlm.nih.gov/1848195/"},{"id":3148,"title":"Tumor cell lysis by activated human neutrophils: analysis of neutrophil-delivered oxidative attack and role of leukocyte function-associated antigen 1.","authors":"Dallegri, F; Ottonello, L; Ballestrero, A; Dapino, P; Ferrando, F; Patrone, F; Sacchetti, C","year":1991,"date":"1991 Feb","journal":"Inflammation","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"The lysis of tumor cells, and other nucleated mammalian cells, by neutrophilic polymorphonuclear leukocytes (PMNs) triggered by phorbol myristate acetate (PMA) represents a widely used model system to dissect the PMN cytolytic armamentarium, potentially responsible for the cell damage at tissue sites of PMN activation. Although oxidants are generally considered to be instrumental in the target lysis by PMNs, the mediators actually involved remain a matter of controversy. Moreover, other factors potentially crucial to the lysis have not been clearly identified. In order to reexamine the determinants of the cytolytic process, we studied the events underlying the PMA-triggered PMN-delivered attack against two different targets, selected on the basis of preliminary experiments (B lymphoblastoid Daudi cells and erythroleukemic K 562 cells). The results suggest that the lysis is promoted by hypochlorous acid (HOCl) or a compound with characteristics very similar to HOCl itself. No evidence was obtained for the intervention or contribution of hydrogen peroxide (H2O2), hydroxyl (OH.) radicals, and the major HOCl-derived chloramines. PMNs appeared to use 35% of the generated H2O2 to produce HOCl, while the remainder appears to be consumed by PMNs themselves and target cells as well. Moreover, PMNs and target cells coaggregated at an early step of the cytolytic reaction, through a process efficiently prevented by a monoclonal antibody (MoAb J-90) directed against leukocyte function-associated antigen-1 (LFA-1). The inhibition of the PMN-target aggregation by the MoAb J-90 resulted in the impairment of the lysis, despite a normal generation of HOCl. Thus, the data demonstrate that the PMA-triggered lysis of tumor target cells by PMNs requires at least two events, occurring simultaneously: the LFA-1-mediated effector-target adherence and the PMN production of HOCl. The intervention of the LFA-1-mediated PMN-target adherence in the PMA-triggered lysis is likely to allow PMNs to focus HOCl on the target cell surface and suggests that the process requires a sort of molecule to molecule recognition at the effector-target surface level.","pmid":"1647368","doi":"10.1007/BF00917906","url":"https://pubmed.ncbi.nlm.nih.gov/1647368/"},{"id":3150,"title":"The oxidant hypochlorite (OCl-), a product of the myeloperoxidase system, degrades articular cartilage proteoglycan aggregate.","authors":"Katrantzis, M; Baker, M S; Handley, C J; Lowther, D A","year":1991,"date":"1991","journal":"Free radical biology & medicine","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The myeloperoxidase-derived oxidant, hypochlorite (OCl-) was shown to be able to degrade proteoglycan aggregate prepared from bovine articular cartilage. Exposure of proteoglycan aggregate to OCl- concentrations less than 10(-4) M resulted in a decrease in the size of the constituent proteoglycan monomers, which were unable to reaggregate with hyaluronate due to the loss of the hyaluronic acid binding region as indicated by immunoblotting using the monoclonal 1-C-6 antibody. Analysis of the [35S]-labeled core proteins by SDS/polyacrylamide electrophoresis and fluorography indicated a decrease in the size of the core protein. These data suggest that concentrations of OCl- below 10(-3) M results in the cleavage of the proteoglycan core protein in or near the hyaluronic acid binding region. The physiological consequences of these data are discussed. Exposure to higher concentrations (greater than 10(-3)) of OCl- caused more extensive degradation of the core protein; however, there was no evidence to suggest that OCl- cleaves glycosaminoglycan (GAG) chains.","pmid":"1849864","doi":"10.1016/0891-5849(91)90003-l","url":"https://pubmed.ncbi.nlm.nih.gov/1849864/"},{"id":3153,"title":"Induction of arthritis in rats by aqueous suspensions of mycobacteria without the use of oil.","authors":"Levine, S; Saltzman, A","year":1991,"date":"1991 Jan","journal":"Arthritis and rheumatism","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"We report for the first time the induction of arthritis by an aqueous, rather than an oil, suspension of killed tubercle bacilli. This was accomplished in the highly susceptible dark Agouti strain of rats, by intraperitoneal injection during the healing phase of chemically induced peritonitis. The same procedure (injection after the induction of peritonitis) augmented the incidence of arthritis produced by bovine type II collagen and Freund's complete adjuvant. Enhanced delivery of antigen from the peritoneal cavity to regional lymph nodes in the postinflammatory state was responsible for this increase in the induction of arthritis.","pmid":"1845840","doi":"10.1002/art.1780340110","url":"https://pubmed.ncbi.nlm.nih.gov/1845840/"},{"id":3154,"title":"Topical treatment of burn wounds with chloroxidating solution and silver sulfadiazine: a comparative study.","authors":"Mian, E U; Gianfaldoni, R; Mian, M","year":1991,"date":"1991","journal":"Drugs under experimental and clinical research","category":"Human clinical & healthcare","evidence":"Clinical trial","relevance":"Medium","abstract":"The present paper reports the results of clinical and laboratory tests carried out on two homogeneous groups of ten burn patients subjected to local therapy, either with isotonic chloroxidating solution Amuchina* or with 1% silver sulfadiazine cream at the Burns Centre of the Pisa University Dermatological Clinic. The local systemic behaviour of the patients examined was evaluated for the containment of septic complications at the burn site. In the group subjected to treatment with chloroxidating solution, sepsis appeared to have a lower incidence in the evolution of dermatitis in the phase of escharolysis, in the formation of granulation tissue, and in the attachment of cutaneous grafts. The systemic involvement (temperature curve, etc.) appeared to be more marked for some patients treated with silver sulfadiazine in response to septic aggression of the burn wounds. On the basis of data referring to the development of the wound granulation and the temperature curve, as well as the microbial presence and the subjective tolerance of the medication, the comparison was favourable, making all necessary allowances, to topical treatment with electrolytic chloroxidating solution; other comparative data were at the limit of significance.","pmid":"1665411","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/1665411/"},{"id":3156,"title":"HOCl exposure of a human airway epithelial cell line decreases its plasma membrane neutral endopeptidase.","authors":"Lang, Z H; Murlas, C G","year":1991,"date":"1991","journal":"Lung","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"It has recently been demonstrated that luminal exposure of airway segments in vitro to HOCl produces airway muscle hyperresponsiveness to substance P and a decrease in neutral endopeptidase (NEP) activity of tissue segment homogenates, suggesting that HOCl may decrease airway epithelial cell NEP activity. To confirm that this effect occurs in humans and to investigate possible subcellular mechanisms for it, we assessed HOCl exposure of the human airway epithelial cell line Calu-1. These cells, grown to confluency in Dulbecco's modified Eagle medium with 10% fetal bovine serum and penicillin-streptomycin, were exposed in situ for 5 min to 100 microM HOCl in a phosphate-buffered saline solution (PBS; pH 7.0 at 37 degrees C) or to PBS alone. Thereafter, cells were rinsed and assayed for NEP activity employing reverse-phase high-pressure liquid chromatography. This activity was characterized by the generation of phosphoramidon-inhibitable product (ANA) cleaved from the synthetic substrate succinyl-(ala)3-p-nitroaniline during a 30 min incubation at 37 degrees C. Cell viability was assessed by changes in LDH release, trypan blue exclusion, and cell volume. In some experiments, crude plasma membrane and soluble components of exposed cells were isolated and differential NEP activity was assayed. We found that a 5 min exposure to HOCl decreased whole cell NEP activity from 74.1 +/- 4.4 (mean +/- SE) to 54.3 +/- 6.0 pmoles of ANA/min/10(6) cells (p less than 0.05), while no parameter of cell viability was affected. NEP activity in the crude membrane fraction decreased 36.3 +/- 3.1% after exposure (p less than 0.01), whereas NEP activity in the soluble fraction increased 4.0 +/- 0.6%. Isolated membrane NEP exposed by itself was not affected. Subsequent experiments with reducing agents demonstrated that NEP activity of cell cultures pretreated with 100 mM of either beta-mercaptoethanol or dithiothrietol before HOCl exposure was not significantly different from control values. We conclude that whole cell HOCl exposure decreases Calu-1 plasma membrane NEP. This loss appears to occur by internalization of cell membrane NEP.","pmid":"1661804","doi":"10.1007/BF02714168","url":"https://pubmed.ncbi.nlm.nih.gov/1661804/"},{"id":3161,"title":"The effects of disinfectants on the dimensional stability of alginate impression materials.","authors":"Ralph, W J; Gin, S S; Cheadle, D A; Harcourt, J K","year":1990,"date":"1990 Dec","journal":"Australian dental journal","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Glutaraldehyde and hypochlorite solutions have been shown to be effective disinfectants for use in the dental surgery. However, their use in the disinfecting of alginate hydrocolloid impression materials must be open to question since these materials are dimensionally unstable when immersed in aqueous solutions for any length of time. This project investigated the dimensional changes noted in casts poured into alginate impressions which had been stored for up to 60 minutes in either hypochlorite or glutaraldehyde solutions. All changes measured were considered to be within clinical tolerance.","pmid":"1965275","doi":"10.1111/j.1834-7819.1990.tb04682.x","url":"https://pubmed.ncbi.nlm.nih.gov/1965275/"},{"id":3162,"title":"Depolymerization of synovial fluid hyaluronic acid (HA) by the complete myeloperoxidase (MPO) system may involve the formation of a HA-MPO ionic complex.","authors":"Green, S P; Baker, M S; Lowther, D A","year":1990,"date":"1990 Dec","journal":"The Journal of rheumatology","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Gel filtration analysis (Sephacryl S-1000) indicated that the Mr of purified equine synovial cell culture 3H-hyaluronic acid (HA) (Mr greater than 1.67 x 10(7) Da) decreased in a concentration dependent manner after exposure to hypochlorite (OCl-). Both high (equine) and medium (human, Mr = 5.5 x 10(5) Da) molecular weight HA were cleaved by the complete myeloperoxidase system (MPO/H2O2/Cl-). Purified human neutrophil myeloperoxidase (MPO) bound tightly to HA-Sepharose and we suggest that this is due to a strong ionic interaction between HA and MPO. The formation of such a complex did not disturb MPO activity. The significance of these results in relation to our previous studies concerning the reduction in viscosity and potential cleavage of HA by the product of the MPO/H2O2/Cl- system is discussed.","pmid":"1964699","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/1964699/"},{"id":3169,"title":"Tumor necrosis factor infusions in humans prime neutrophils for hypochlorous acid production.","authors":"Wewers, M D; Rinehart, J J; She, Z W; Herzyk, D J; Hummel, M M; Kinney, P A; Davis, W B","year":1990,"date":"1990 Oct","journal":"The American journal of physiology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Five cancer patients undergoing intravenous infusions of human recombinant tumor necrosis factor (TNF)alpha were evaluated for the effects these infusions had on the priming of circulating neutrophils for hypochlorous acid (HOCl) production. These patients were also studied for changes in temperature, circulating white blood cell counts, blood pressure, and spontaneous monocyte interleukin 1 beta (IL-1 beta) and TNF production. As predicted by previous in vitro studies, patient neutrophils increased their HOCl production to unopsonized zymosan from a baseline of 29.2 +/- 5.9 nmol I- oxidized/4 x 10(6) cells to a peak of 64.2 +/- 9.8 nmol I- oxidized/4 x 10(6) cells at 4 h after TNF infusion (P less than 0.01). Similar increases were also seen at 4 h with phorbol myristic acetate and opsonized zymosan as the stimuli. The priming effect could be reproduced in neutrophils from a normal individual by incubating them with the 30-min serum samples from the infused patients. The ability of this serum to prime neutrophils was completely blocked by a monoclonal anti-TNF alpha-antibody but not by an anti-IL-1 beta antibody. In addition to the priming of their neutrophils, patients also experienced fever, marked hypotension, and an initial fall, followed by rebound to an elevation, in circulating white blood cell counts. The TNF infusions did not produce detectable circulating IL-1 beta nor did they induce significant production of TNF or IL-1 beta by circulating blood monocytes. These studies confirm the role of TNF in producing the signs of sepsis such as hypotension, fever, and leukopenia followed by leukocytosis.(ABSTRACT TRUNCATED AT 250 WORDS)","pmid":"2171355","doi":"10.1152/ajplung.1990.259.4.L276","url":"https://pubmed.ncbi.nlm.nih.gov/2171355/"},{"id":3171,"title":"The mechanism of myeloperoxidase-catalysed oxidation of aminopyrine.","authors":"Sayo, H; Saito, M","year":1990,"date":"1990 Sep","journal":"Xenobiotica; the fate of foreign compounds in biological systems","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"1. Myeloperoxidase catalysed the H2O2-supported oxidation of aminopyrine in the presence of Cl-, generating the aminopyrine cation radical (AP+.). The rate of AP+. formation was determined by monitoring the absorbance at 565 nm. The pH optimum of the reaction was around 5.0. The rate of AP+. formation increased with increasing concentration of aminopyrine. Inhibition by excess H2O2 was seen at pH 4.5-5.5. 2. When Cl- was replaced by Br-, the rate of AP+. formation increased significantly, and inhibition by H2O2 became less evident and was observed only at pH 5.5. The rate of chemical oxidation of aminopyrine by HOCl was much slower than that by Br2. 3. Compared with the chlorination of monochlorodimedone (MCD), the reaction between aminopyrine and HOCl, produced by the enzymic peroxidation of Cl-, is rate-limiting in the myeloperoxidase-catalysed oxidation of aminopyrine. The differences in kinetic behaviour between the myeloperoxidase-catalysed chlorination of MCD and oxidation of aminopyrine are explained by the low reactivity of HOCl towards aminopyrine.","pmid":"2173287","doi":"10.3109/00498259009046911","url":"https://pubmed.ncbi.nlm.nih.gov/2173287/"},{"id":3172,"title":"Ibuprofen attenuates hypochlorous acid production from neutrophils in porcine acute lung injury.","authors":"Carey, P D; Byrne, K; Jenkins, J K; Sielaff, T D; Walsh, C J; Fowler, A A 3rd; Sugerman, H J","year":1990,"date":"1990 Sep","journal":"The Journal of surgical research","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Hypochlorous acid (HOCl), a neutrophil-generated oxidant, has been implicated in tissue destruction in sepsis-induced acute lung injury (ALI). Ibuprofen, a cyclooxygenase inhibitor, successfully attenuates many of the physiological derangements in ALI. The aim of this study was to examine the role of PMN hypochlorous acid in sepsis-induced ALI and evaluate the effect of ibuprofen therapy. Neutrophils from three groups of young (15-25 kg), anesthetized swine were studied: controls (C, n = 7) received 0.9% NaCl, septic animals (Ps, n = 8) received live Pseudomonas aeruginosa (5 x 10(8) CFU/ml at 0.3 ml/20 kg/min) for 60 min, and ibuprofen-treated animals (Ps + I, n = 6) received Ps plus ibuprofen 12.5 mg/kg administered at 0 and 120 min. Neutrophils were isolated from peripheral blood at 0, 60, and 300 min and the rate and total production of HOCl were assessed on the basis of the ability of the amino acid taurine to trap HOCl. RESULTS: Septic (Ps) PMNs produce 32% more HOCl, P less than 0.01, at 300 min than at baseline which was associated with a marked increase in both extravascular lung water (6.44 +/- 0.8 ml/kg, t = 0 vs 16.03 +/- 2.6 ml/kg, t = 300, P less than 0.01) and bronchoalveolar protein content (115 +/- 13 micrograms/ml, t = 0 vs 633 +/- 104 micrograms/ml, t = 300, P less than 0.01). Ibuprofen significantly attenuated (P less than 0.05) HOCl production when compared to Ps, in conjunction with significantly (P less than 0.05) reduced levels of extravascular lung water and bronchoalveolar lavage protein.","pmid":"2168503","doi":"10.1016/0022-4804(90)90131-k","url":"https://pubmed.ncbi.nlm.nih.gov/2168503/"},{"id":3174,"title":"Oxidant-induced increases in mucosal permeability in developing piglets.","authors":"Clark, E S; Crissinger, K D; Granger, D N","year":1990,"date":"1990 Jul","journal":"Pediatric research","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Reactive oxygen metabolites have been implicated in the pathogenesis of mucosal injury induced by ischemia-reperfusion in adult animals, with recent interest centering on the capacity of polymorphonuclear neutrophil-derived oxidants to mediate this injury. A role for oxidants has also been postulated in the etiology of neonatal necrotizing enterocolitis. Based on evidence that the intrinsic capacity of the neonatal piglet intestine to detoxify hydrogen peroxide (H2O2) is minimal relative to that of older piglets, we characterized the changes in mucosal permeability induced by luminal perfusion with H2O2 and hypochlorous acid at concentrations that can be produced physiologically by activated neutrophils (0.05 mmol/L, 0.1 mmol/L, and 0.5 mmol/L), in the distal ileum of 1-d- and 1-mo-old piglets. Mucosal permeability was quantitated by measurement of blood-to-lumen clearance of 51-labeled chromium EDTA. Luminal perfusion with either H2O2 (0.05 mmol/L and 0.1 mmol/L) or hypochlorous acid (0.1 mmol/L and 0.5 mmol/L) significantly increased mucosal permeability in newborn piglets but did not affect mucosal permeability in 1-mo-old animals. Perfusion with 0.5 mmol/L H2O2 significantly increased mucosal permeability over control values in both age groups, but injury in the newborn intestine was significantly greater than that observed in 1-mo-old animals. Thus, as predicted by the reduced intrinsic capacity of the mucosa of neonatal piglets to detoxify H2O2, the ileum of newborn piglets is more vulnerable to oxidant-induced mucosal injury than is the ileum of older animals.","pmid":"2165584","doi":"10.1203/00006450-199007000-00007","url":"https://pubmed.ncbi.nlm.nih.gov/2165584/"},{"id":3178,"title":"HOCl causes airway substance P hyperresponsiveness and neutral endopeptidase hypoactivity.","authors":"Murlas, C G; Murphy, T P; Lang, Z","year":1990,"date":"1990 Jun","journal":"The American journal of physiology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"We investigated whether exposure of guinea pig tracheal tissue to hypochlorous acid (HOCl) or hydrogen peroxide (H2O2) by perfusion through the airway lumen affected the responsiveness of airway muscle to ACh, KCl, or substance P in the presence or absence of 1 microM phosphoramidon, an inhibitor of neutral endopeptidase (NEP). Pairs of tracheal segments were immersed in a Krebs solution (pH 7.40 at 37 degrees C) and connected to perfusion circuits so that the lumen of one segment of each pair could be perfused with Krebs solution while the other was perfused for the same time (10 min) with either 0.1 microM HOCl or 10 mM H2O2. Segments after perfusion were cut into rings of similar size and placed in muscle chambers so that airway muscle force generation in vitro could be measured on stimulation by cumulative agonist doses. In addition, cell homogenates were made from other, similarly perfused tracheal segments to assess NEP activity using reverse-phase, high-pressure liquid chromatography (HPLC). We found that smooth muscle of mucosa-intact guinea pig airways perfused with HOCl, but not H2O2, was hyperresponsive to substance P but not to ACh or KCl. HOCl-perfused rings were not different from Krebs solution-exposed rings pretreated with phosphoramidon. There was no increase in substance P responsiveness of HOCl-exposed airways in which the mucosa had been removed before testing in vitro. The substance P hyperresponsiveness of HOCl-exposed, mucosa-intact airways was associated with decreased NEP activity.(ABSTRACT TRUNCATED AT 250 WORDS)","pmid":"1694406","doi":"10.1152/ajplung.1990.258.6.L361","url":"https://pubmed.ncbi.nlm.nih.gov/1694406/"},{"id":3180,"title":"Effects of neutrophils and in vitro oxidants on survival and phenotypic switching of Candida albicans WO-1.","authors":"Kolotila, M P; Diamond, R D","year":1990,"date":"1990 May","journal":"Infection and immunity","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The relationship to pathogenesis of the spontaneous phenotypic switching of Candida albicans is uncertain. Since neutrophils are critical in containment of disseminated candidiasis, we used these cells and some of their potentially microbicidal oxidative products to define effects on a C. albicans strain (WO-1) that exhibits characteristic, easily recognized switching between the white and opaque phenotypes. Blastoconidia of the opaque phenotypes were more susceptible than those of the white to killing by either intact neutrophils or cell-free oxidants, including reagent hydrogen peroxide or the myeloperoxidase-H2O2-Cl- system. Paralleling these findings, opaque blastoconidia were 2.8- to 3.6-fold more potent stimuli of neutrophil superoxide generation than were the white cells. In addition, both neutrophils and oxidants (reagent H2O2 or hypochlorous acid as well as the myeloperoxidase-H2O2-Cl- system) induced unidirectional increases in spontaneous rates of switching from white to opaque phenotypes. Differences in expression of C. albicans phenotypes therefore may determine relative susceptibility to neutrophil fungicidal mechanisms, and neutrophils themselves appear to be capable of selectively augmenting the switching process.","pmid":"2157666","doi":"10.1128/iai.58.5.1174-1179.1990","url":"https://pubmed.ncbi.nlm.nih.gov/2157666/"},{"id":3181,"title":"Kinetic studies on the reaction of compound II of myeloperoxidase with ascorbic acid. Role of ascorbic acid in myeloperoxidase function.","authors":"Marquez, L A; Dunford, H B; Van Wart, H","year":1990,"date":"1990 Apr 5","journal":"The Journal of biological chemistry","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Ascorbic acid is known to stimulate leukocyte functions. In a recent publication it was suggested that the role of ascorbic acid is to reduce compound II of myeloperoxidase back to the native enzyme (Bolscher, B. G. J. M., Zoutberg, G. R., Cuperus, R. A., and Wever, R. (1984) Biochim. Biophys. Acta 784, 189-191). In this paper we report rapid spectral scan and transient state kinetic results on the reaction of three myeloperoxidase compounds II, namely, human neutrophil myeloperoxidase, canine myeloperoxidase, and bovine spleen heme protein with ascorbate. We show by rapid scan spectra that compound II does not pass through any other intermediate when ascorbic acid reduces it back to native form. We also show that the reactions of all three compounds II involve a simple binding interaction before enzyme reduction with an apparent dissociation constant of 6.3 +/- 0.9 x 10(-4) to 2.0 +/- 0.3 x 10(-3)M and a first-order rate constant for reduction of 12.6 +/- 0.6 to 18.8 +/- 1.3 s-1. The optimum pH is 4.5, and at this pH the activation energy for the reaction is 13.2 kJ mol-1. Results of this work lend further evidence that the spleen green heme protein is very similar if not identical to leukocyte myeloperoxidase based on a comparison of spectral scans, pH-rate profiles, and kinetic parameters. We demonstrate that chloride cannot reduce compound II whereas iodide reduces compound II to native enzyme at a rate comparable to that of ascorbate. This explains why ascorbate accelerates chlorination but inhibits iodination. Formation of compound II is a dead end for the generation of hypochlorous acid; ascorbate regenerates more native enzyme to enhance the chlorination reaction namely: myeloperoxidase + peroxide----compound I followed by compound I + chloride----HOCl. On the other hand, ascorbate is a competitor with iodide for both compounds I and II and so inhibits iodination.","pmid":"2156823","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/2156823/"},{"id":3186,"title":"The chlorinating activity of human myeloperoxidase: high initial activity at neutral pH value and activation by electron donors.","authors":"Zuurbier, K W; Bakkenist, A R; Wever, R; Muijsers, A O","year":1990,"date":"1990 Feb 9","journal":"Biochimica et biophysica acta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The steady-state activity of myeloperoxidase in the chlorination of monochlorodimedone at neutral pH was investigated. Using a stopped-flow spectrophotometer we were able to show that the enzymic activity at pH 7.2 rapidly declined in time. During the first 50-100 ms after addition of H2O2 to the enzyme, a turnover number of about 320 s-1 per haem was observed. However, this activity decreased rapidly to a value of about 25s-1 after 1 s. This shows that in classical steady-state activity measurements, the real activity of the enzyme at neutral pH is grossly underestimated. By following the transient spectra of myeloperoxidase during turnover it was shown that the decrease in activity was probably caused by the formation of an enzymically inactive form of the enzyme, Compound II. As demonstrated before (Bolscher, B.G.J.M., Zoutberg, G.R., Cuperus, R.A. and Wever, R. (1984) Biochim. Biophys. Acta 784, 189-191) reductants such as ascorbic acid and ferrocyanide convert Compound II, which accumulates during turnover, into active myeloperoxidase. Activity measurements in the presence of ascorbic acid showed, indeed, that the moderate enzymic activity was higher than in the absence of ascorbic acid. With 5-aminosalicylic acid present, however, the myeloperoxidase activity remained at a much higher level, namely about 150 s-1 per haem during the time interval from 100 ms to 5 s after mixing. From combined stopped-flow/rapid-scan experiments during turnover it became clear that in the presence of 5-aminosalicylic acid the initially formed Compound II was rapidly converted back to native enzyme. Presteady-state experiments showed that 5-aminosalicylic acid reacted with Compound II with a K2 of 3.2 x 10(5) M-1.s-1, whereas for ascorbic acid a K2 of 1.5 x 10(4) M-1.s-1 was measured at pH 7.2. In the presence of 5-aminosalicylic acid during the time interval in which the myeloperoxidase activity remained constant, a Km for H2O2 at pH 7.2 was determined of about 30 microM at 200 mM chloride. In the absence of reductants the same value was found during the first 100 ms after addition of H2O2 to the enzyme. The physiological consequences of these findings are discussed.","pmid":"2155024","doi":"10.1016/0167-4838(90)90159-d","url":"https://pubmed.ncbi.nlm.nih.gov/2155024/"},{"id":3193,"title":"Ultrastructure, morphology and crystal growth of biogenic and synthetic apatites.","authors":"Heywood, B R; Sparks, N H; Shellis, R P; Weiner, S; Mann, S","year":1990,"date":"1990","journal":"Connective tissue research","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"The morphology, structure and crystal growth of apatite crystals isolated from calcified turkey tendon and synthetic carbonated apatites have been examined using high resolution transmission electron microscopy. The biogenic apatite consisted of small (35 x 20 x 5 nm) platelike crystals. Despite their irregular shape and ill-defined edges, individual particles were single domain crystals. Lattice images recorded from isolated turkey tendon crystals indicated that the crystallographic c-axis (0001) of apatite lies in the plane of the plate and parallel to the length of the crystallites. Lattice images suggested that the top face corresponds to the (1100) face of carbonated apatite. Lattice fringes observed in platelike crystallites viewed from the side corresponded to the projection of the apatite structure viewed along the [1120] direction. Thus, it can be argued that crystal growth is constrained along the [1100] direction, extends laterally along the [1120] direction, and is maximal along the [0001] direction. This latter direction is aligned with the collagen fiber axis. A mean length to width ratio (1.7) was determined by systemically measuring the maximum distances parallel and perpendicular to the c-axis identified from lattice images of the crystals. Similar information was obtained from lattice images of crystals located in collagen fibres. This confirmed that the morphological and structural features of isolated turkey tendon apatite crystals correlate directly with the in vivo crystallochemical characteristics of apatite. Crystals of synthetic carbonated apatite prepared at 37 degrees C were also platelike and, although generally much larger, had length to width ratios comparable with the turkey tendon apatite. The synthetic carbonated apatites were noticeably more sensitive to radiolytic damage than the turkey tendon crystals. The crystallographic c-axis of the inorganic particles was aligned parallel with the long, physical axis of the plate and the top face was identified as (1100). Similar data were also obtained from noncarbonated synthetic apatite samples. The results of the present study offer critical information about the crystal growth of individual carbonated apatite crystals in calcified turkey tendon and its relationship to the morphology of the crystallites. As similar growth characteristics are expressed in synthetic analogues, the data bring into question the putative regulatory role of the collagen-based matrix upon the nucleation and growth of biogenic apatite.(ABSTRACT TRUNCATED AT 400 WORDS)","pmid":"2175692","doi":"10.3109/03008209009006985","url":"https://pubmed.ncbi.nlm.nih.gov/2175692/"},{"id":3196,"title":"Hypochlorite-modified adenine nucleotides: structure, spin-trapping, and formation by activated guinea pig polymorphonuclear leukocytes.","authors":"Bernofsky, C; Bandara, B M; Hinojosa, O; Strauss, S L","year":1990,"date":"1990","journal":"Free radical research communications","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Adenosine and its nucleotides react with hypochlorite to form unstable products that have been identified as the N6 chloramine derivatives. These chloramines spontaneously oligomerize, form stable adducts with proteins and nucleic acids, and are converted with loss of chlorine to the original nucleoside or nucleotide by reducing agents. The chloramines are associated with a free radical, and the spin-trapping of adenosine chloramine with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) yielded a mixture of unstable nitroxyl adducts that corresponded to nitrogen-centered radicals from the parent nucleoside. When activated guinea pig polymorphonuclear leukocytes were stimulated with phorbol myristate acetate to produce hypochlorite, they actively incorporated [14C]adenosine into acid-insoluble products by a process that was dependent on oxygen and inhibited by azide and thiols. These findings suggest that adenine nucleotide chloramines are generated by activated phagocytic cells and form ligands with proteins and nucleic acids as observed in model systems. The results imply that nucleotide chloramines are among the cytotoxic and possibly mutagenic factors that are associated with the inflammatory process.","pmid":"2167269","doi":"10.3109/10715769009145689","url":"https://pubmed.ncbi.nlm.nih.gov/2167269/"},{"id":3202,"title":"Flow injection fluorometry of protein using hypochlorite-thiamine reagent.","authors":"Yokoyama, T; Nakamura, N; Kinoshita, T","year":1990,"date":"1990 Jan","journal":"Analytical biochemistry","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"This paper describes a flow injection protein assay based on the formation of N-chlorides. Thiamine, which gives fluorescent thiochrome on reaction with N-chlorides, is used as a reagent. The protein sample is first mixed with the carrier solution containing sodium hypochlorite to chlorinate peptide bonds. The fluorescence reagent, containing thiamine and sodium nitrite, is then delivered to the mixture; the sodium nitrite decomposes active chlorine. The assay is sensitive, reproducible, and linear over a range from 20 ng to 2 micrograms of bovine serum albumin. The fluorescence intensity reflects the correct amount of protein because the thiochrome formed is proportional to the number of peptide bonds.","pmid":"2157350","doi":"10.1016/0003-2697(90)90031-4","url":"https://pubmed.ncbi.nlm.nih.gov/2157350/"},{"id":3204,"title":"Can we obtain a further reduction of peritonitis episodes in CAPD patients already using a Y-set with disinfectant?","authors":"Viglino, G; Gandolfo, C; Cottino, R; Mariano, F; Goia, F; Servetti, L; Rivetti, M; Cavalli, P L","year":1990,"date":"1990","journal":"Advances in peritoneal dialysis. Conference on Peritoneal Dialysis","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"A protocol of patient selection and more frequent home visits have significantly reduced peritonitis episodes in CAPD patients using Y-set with Amuchina. However, no change in dropout rates were observed.","pmid":"1982795","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/1982795/"},{"id":3206,"title":"Oxidative stress and receptor responses in guinea-pig tracheal tissue.","authors":"Doelman, C J; de Vlieger, J F; Sprong, R C; Bast, A","year":1990,"date":"1990","journal":"Agents and actions. Supplements","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Reactive oxygen species are formed during inflammatory reactions in the lung. Alveolar macrophages and neutrophils and eosinophils produce superoxide anions, hydrogen peroxide, hydroxyl radicals and singlet oxygen. Neutrophils and eosinophils produce also hypochlorous acid. We now present the effects of hydrogen peroxide and hypochlorous acid on muscarinic and beta-adrenergic receptor responses of guinea pig tracheal tissue. Hydrogen peroxide (up to 10 mM) has no effect on these receptor responses, but in contrast hypochlorous acid destructs the muscarinic and beta-adrenergic receptor response. The beta-adrenergic receptor response is more susceptible to hypochlorous acid treatment than the muscarinic receptor response. This indicates that hypchlorous acid induces an autonomic imbalance between parasympatic and sympatic receptor responses in the guinea pig trachea.","pmid":"1964361","doi":"10.1007/978-3-0348-7379-6_19","url":"https://pubmed.ncbi.nlm.nih.gov/1964361/"},{"id":3207,"title":"[The oxidation of superoxide dismutase by hypochlorite. The occurrence of isomers having catalytic activity].","authors":"Sharonov, B P; Churilova, I V","year":1990,"date":"1990","journal":"Doklady Akademii nauk SSSR","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"","pmid":"1963588","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/1963588/"},{"id":3208,"title":"Formation of chloramine derivatives of histamine: role of histamine chloramines in bronchoconstriction.","authors":"Wright, C D; Low, J E","year":1989,"date":"1989 Dec 29","journal":"Biochemical and biophysical research communications","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Hypochlorous acid generated by myeloperoxidase reacts with histamine to produce chloramines. At pH 7, one mole of histamine monochloramine (HisCl) was generated per mole of H2O2 provided as substrate for myeloperoxidase. At pH 5, one mole of histamine dichloramine (HisCl2) was generated per two moles of H2O2. HisCl and HisCl2 had two and four oxidizing equivalents per molecule, respectively. In vitro, 30 microM HisCl and HisCl2 induced mepyramine-sensitive guinea pig lung parenchyma contraction with 89 and 56 percent of the response of an equivalent concentration of histamine. Pretreatment of lung strips with chloramines reduced the subsequent contractile response of the tissues to methacholine. These results suggest that H-1 histamine receptors provide for targeting of histamine chloramines to pulmonary tissue which may facilitate modification of tissue responses.","pmid":"2558645","doi":"10.1016/0006-291x(89)92704-6","url":"https://pubmed.ncbi.nlm.nih.gov/2558645/"},{"id":3209,"title":"The effects of chemical sterilisation on the dimensional stability of some elastomeric impression materials.","authors":"Salem, N; Combe, E C","year":1990,"date":"1990","journal":"Clinical materials","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"The dimensional stability of a range of dental elastomeric impression materials has been assessed, to study the effect of storage in sterilising solutions. Experiments were carried out on polysulphides, a poly(ether urethane) and several condensation and addition silicones. The last materials had the greatest dimensional stability over a range of storage conditions, which included aqueous glutaraldehyde and hypochlorite solutions.","pmid":"10150081","doi":"10.1016/0267-6605(90)90046-x","url":"https://pubmed.ncbi.nlm.nih.gov/10150081/"},{"id":3212,"title":"General mechanism for the bacterial toxicity of hypochlorous acid: abolition of ATP production.","authors":"Barrette, W C Jr; Hannum, D M; Wheeler, W D; Hurst, J K","year":1989,"date":"1989 Nov 14","journal":"Biochemistry","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"The adenylate energy charges (EC) of Escherichia coli 25922, Pseudomonas aeruginosa 27853, and Streptococcus lactis 7962 rapidly fell in nutrient-rich media from values in excess of 0.9 to below 0.1 when the organisms were exposed to lethal levels of HOCl. The same cells maintained in energy-depleted states were incapable of attaining normal EC values necessary for biosynthesis and growth when challenged with nutrient energy sources after HOCl exposure. These changes correlated quantitatively with loss of replicative capabilities. Initial rates of transport of glucose, succinate, and various amino acids that act as respiratory substrates and the ATP hydrolase activity of the F1 complex from the ATP synthase of E. coli 25922 also declined in parallel with or preceded loss of viability. These results establish that cellular death is accompanied by complete disruption of bacterial ATP production by both oxidative and fermentative pathways as a consequence of inhibition of inner membrane bound systems responsible for these processes.","pmid":"2557918","doi":"10.1021/bi00449a032","url":"https://pubmed.ncbi.nlm.nih.gov/2557918/"},{"id":3214,"title":"Mechanisms of human neutrophil-mediated cartilage damage in vitro: the role of lysosomal enzymes, hydrogen peroxide and hypochlorous acid.","authors":"Kowanko, I C; Bates, E J; Ferrante, A","year":1989,"date":"1989 Oct","journal":"Immunology and cell biology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Cartilage is a focal point of attack by cellular and molecular elements of the inflammatory response which occurs in arthritic diseases. Neutrophils damage articular cartilage by degrading matrix components and inhibiting their synthesis. The aim of this study was to elucidate mechanisms of this damage. Human neutrophils were isolated from blood by centrifuging through Ficoll-Hypaque and granule extract prepared from them. Articular cartilage from adult humans and cattle was maintained in organ culture. Cartilage degradation (release of 35S-labelled proteoglycan) or synthesis (incorporation of 35S into proteoglycan) was determined after various treatments. Human neutrophils and neutrophil granule extract degraded proteoglycan and inhibited proteoglycan synthesis. The specific leucocyte elastase inhibitor N-methoxysuccinyl-(ala)2-pro-val-chloromethylketone (MAAPVCMK) partially reversed these effects. H2O2, a product of the neutrophil respiratory burst, when added directly at 10(-6)mol/L, or generated by glucose oxidase (GO)/glucose inhibited proteoglycan synthesis but had no effect on degradation. Hypochlorous acid (OHCl), a product of the myeloperoxidase (MPO)/H2O2/Cl system at 50 mumol/L degraded proteoglycan and inhibited its synthesis. OHCl produced by granule extract (as a source of MPO) + GO-generated H2O2 + Cl- degraded proteoglycan. The results indicate that neutrophil-mediated proteoglycan degradation and inhibition of synthesis is largely attributable to elastase and secondarily to OHCl, whereas H2O2 impairs synthesis without affecting degradation of proteoglycan.","pmid":"2559027","doi":"10.1038/icb.1989.47","url":"https://pubmed.ncbi.nlm.nih.gov/2559027/"},{"id":3225,"title":"A comparison of hypochlorite and phenolic disinfectants for disinfection of clean and soiled surfaces and blood spillages.","authors":"Bloomfield, S F; Miller, E A","year":1989,"date":"1989 Apr","journal":"The Journal of hospital infection","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Suspension test methods were used to compare phenolic and hypochlorite disinfectants under conditions as recommended for use in hospitals. Using plasma to simulate soiled conditions, Clearsol (1% v/v) and Stericol (2% v/v) produced satisfactory disinfection, (i.e. 5 log reduction in 5 mins against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa in the presence of up to 50% v/v plasma (25 mg ml-1 plasma protein). Although sodium dichloroisocyanurate (NaDCC) at 2500 ppm AvCl2 was effective in the presence of up to 20% plasma, compared to 10% plasma for sodium hypochlorite 2500 ppm, sensitivity of NaDCC to inactivation was greater than for phenolics. In the presence of blood, both hypochlorites and phenolics were substantially inactivated, although here the effectiveness of NaDCC at 10,000 ppm was equivalent to the phenolics. Our results indicate that hypochlorites at 10,000 ppm, Clearsol 1% and Stericol 2% may be ineffective for treatment of blood spills unless applied at v:v ratios of 9 parts disinfectant to 1 part blood. In this situation, chlorine-releasing powder formulations, which produce higher AvCl2 concentrations and contain spilled material, offer an effective alternative.","pmid":"2567752","doi":"10.1016/0195-6701(89)90003-0","url":"https://pubmed.ncbi.nlm.nih.gov/2567752/"},{"id":3226,"title":"Role of hypochlorous acid in Trypanosoma musculi killing by phagocytes.","authors":"Vincendeau, P; Daulouède, S; Veyret, B","year":1989,"date":"1989 Apr","journal":"Parasitology","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Trypanosoma musculi are readily killed when phagocytosed by mononuclear phagocytes but the nature of the mediators of this cytotoxicity is unclear. Among the most potent mediators are oxygen-derived species. The generation of chemiluminescence (CL) by peritoneal macrophages from 12 day T. musculi-infected mice, which phagocytose and kill parasites when opsonizing antibodies are present, was recorded in the presence of antibody-coated trypanosomes. Taurine, a specific quencher of hypochlorous acid (HOCl) inhibited CL production by peritoneal macrophages, showing that HOCl is produced during phagocytosis of T. musculi. In vitro, HOCl alone exerted a powerful trypanocidal activity which was inhibited in the presence of specific quenchers. The role of HOCl generated by phagocytes in trypanosome killing was studied using granulocytes which produce more oxygen-derived species than macrophages when stimulated. Phorbol myristate acetate-triggered granulocytes can destroy T. musculi and trypanosome killing is inhibited in the presence of taurine. These data demonstrate that HOCl produced by phagocytes can effectively destroy T. musculi.","pmid":"2548148","doi":"10.1017/s0031182000062168","url":"https://pubmed.ncbi.nlm.nih.gov/2548148/"},{"id":3231,"title":"Prospected randomized study of two Y devices in continuous ambulatory peritoneal dialysis (CAPD).","authors":"Viglino, G; Colombo, A; Scalamogna, A; Cavalli, P L; Guerra, L; Renzetti, G; Gandolfo, C; De Vecchi, A; Barzaghi, V; Balteau, P","year":1989,"date":"1989","journal":"Peritoneal dialysis international : journal of the International Society for Peritoneal Dialysis","category":"Human clinical & healthcare","evidence":"Randomized controlled trial","relevance":"Medium","abstract":"To evaluate acceptability, safety, and efficacy of a Y set with two short branches (TAS) filled with electrolytic chloroxidizer solution during the dwell time, 60 patients were randomly allocated to be treated with the traditional Y set (TCS) or with the TAS. Twenty-three were new patients whereas the remaining 37 were patients already on continuous ambulatory peritoneal dialysis (CAPD) with the TCS. The follow-up was 416.5 months in the control group and 387.4 months in the test group. During the study period there were 6 peritonitis episodes in each group with an incidence of 1 episode every 69.4 patient-months in the control group and 1 episode every 64.6 patient-months in the test group. Twenty-four patients (80%) in the control group and 27 (90%) in the test group were free from peritonitis. The probability to remain free from peritonitis was respectively 87% and 83% in the test group and in control group after 12 months, 70% and 78% after 21 months. Seventy-nine percent of the patients who used both systems preferred the TAS for better handling, lower encumbrance, and major safety. One patient preferred the TCS, three patients did not find any differences between the two devices.","pmid":"2562200","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/2562200/"},{"id":3233,"title":"Free radical scavenging by myocardial fatty acid binding protein.","authors":"Samanta, A; Das, D K; Jones, R; George, A; Prasad, M R","year":1989,"date":"1989","journal":"Free radical research communications","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Recent investigations have indicated the presence of a fatty acid binding protein (FABP) in mammalian heart. This protein binds free fatty acids and their esters with high affinity, however, its physiological role remains unknown. Since FABP constitutes a significant amount of cystolic protein, it is likely that it would be a target for free radical attack. To test this hypothesis, FABP was examined for scavenging against free radicals such as the superoxide anion (O2-), hydroxyl radical (OH.) and hypochlorite radical (OCl.) which may be present in an ischemic reperfused heart. Our results suggest that FABP scavenges O2-, OH. and OCl. as indicated by the FABP inhibition of O2- -dependent reduction of cytochrome c, OH.-dependent hydroxybenzoic acid formation and OCl.-mediated chemiluminescence response. FABP was found to be a more potent scavenger of these free radicals compared to bovine serum albumin. Furthermore, FABP was more effective in scavenging OH. than O2-, and inhibited OH. mediated lipid peroxidation process. These results indicate that FABP can scavenge free radicals which may be present in an ischemic/reperfused heart and, thus, may play a significant physiological role in the heart during ischemia and reperfusion.","pmid":"2553551","doi":"10.3109/10715768909087926","url":"https://pubmed.ncbi.nlm.nih.gov/2553551/"},{"id":3234,"title":"Effects of leukocyte-derived oxidants on sarcolemmal Na,K,ATP-ase and calcium transport.","authors":"Matsuoka, T; Yanagishita, T; Kako, K J","year":1989,"date":"1989","journal":"Advances in experimental medicine and biology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Our study demonstrated that the Na,K,ATPase activity and ouabain binding sites were reduced by oxidants. Sarcolemmal calcium transport was also inhibited by hydrogen peroxide and HOC1. The action of HOC1 on the sarcolemmal functions was 2-3 orders of magnitude more powerful than that of hydrogen peroxide. Effects of hydrogen peroxide consisted of two components, i.e., the first, highly sensitive one, most probably mediated by Fe-catalyzed, site-specific free radical formation, and the second, less potent action by (high concentrations of) hydrogen peroxide. Finally, very low concentrations of hydrogen peroxide potentiated Na,K,ATPase activities when assayed using myocytes.","pmid":"2551139","doi":"10.1007/978-1-4684-5643-1_69","url":"https://pubmed.ncbi.nlm.nih.gov/2551139/"},{"id":3235,"title":"Leukocytic oxygen activation and microbicidal oxidative toxins.","authors":"Hurst, J K; Barrette, W C Jr","year":1989,"date":"1989","journal":"Critical reviews in biochemistry and molecular biology","category":"Water, sanitation & biosecurity","evidence":"Review","relevance":"High","abstract":"Following a brief introduction of cellular response to stimulation comprising leukocyte activation, three major areas are discussed: (1) the neutrophil oxidase; (2) myeloperoxidase (MPO)-dependent oxidative microbicidal reactions; and (3) MPO-independent oxidative reactions. Topics included in section (A) are current views on the activation mechanism, redox composition, structural and topographic organization of the oxidase, and its respiratory products. In section (B), emphasis is placed on recent research on cidal mechanisms of HOCl, including the oxidative biochemistry of active chlorine compounds, identification of sites of lesions in bacteria, and attendant metabolic consequences. In section (C), we review the (bio)chemistry of H2O2 and .OH microbicidal reactions, with particular attention being given to addressing the controversial issue of probe methods to identify .OH radical and critical assessment of the recent proposal that MPO-independent killing arises from site-specific metal-catalyzed Fenton-type chemistry.","pmid":"2548810","doi":"10.3109/10409238909082555","url":"https://pubmed.ncbi.nlm.nih.gov/2548810/"},{"id":3239,"title":"The inhibitory effect of acetaminophen on the myeloperoxidase-induced antimicrobial system of the polymorphonuclear leukocyte.","authors":"van Zyl, J M; Basson, K; van der Walt, B J","year":1989,"date":"1989 Jan 1","journal":"Biochemical pharmacology","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Acetaminophen binds via its acetamido side chain to purified myeloperoxidase in a pH-dependent manner and maximum binding occurred around pH 6. The H2O2-dependent myeloperoxidase-catalysed polymerization products of acetaminophen had excitation maxima at 304 nm and 334 nm in acid and alkaline solutions, respectively, and an intense blue fluorescence maximum at 426 nm. Acetaminophen can compete effectively with Cl- as myeloperoxidase substrate and thus HOCl formation is suppressed while HOCl, nevertheless present, can be scavenged by the drug. In this way the microbicidal action of the myeloperoxidase-H2O2-Cl- system can be seriously limited in the presence of high concentrations of acetaminophen. To study the effect of acetaminophen on peptide bond splitting in the myeloperoxidase antimicrobial system, thyroglobulin was used as a model peptide. Peptide bond splitting was inhibited at acetaminophen concentrations below the accepted toxic range for plasma values.","pmid":"2535934","doi":"10.1016/0006-2952(89)90163-9","url":"https://pubmed.ncbi.nlm.nih.gov/2535934/"},{"id":3246,"title":"The mechanism of myeloperoxidase-dependent chlorination of monochlorodimedon.","authors":"Kettle, A J; Winterbourn, C C","year":1988,"date":"1988 Nov 23","journal":"Biochimica et biophysica acta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Chlorination of monochlorodimedon is routinely used to measure the production of hypochlorous acid catalysed by myeloperoxidase from H2O2 and Cl-. We have found that the myeloperoxidase/H2O2/Cl- system, at pH 7.8, catalysed the loss of monochlorodimedon with a rapid burst phase followed by a much slower steady-state phase. The loss of monochlorodimedon in the absence of Cl- was only 10% of the steady-state rate in the presence of Cl-, which indicates that the major reaction of monochlorodimedon was with hypochlorous acid. During the steady-state reaction, myeloperoxidase was present as 100% compound II, which cannot participate directly in hypochlorous acid formation. Monochlorodimedon was necessary for formation of compound II, since it was not formed in the presence of methionine. Both the amount of hypochlorous acid formed during the burst phase, and the steady-state rate of hypochlorous acid production, increased with increasing concentrations of myeloperoxidase and with decreasing concentrations of monochlorodimedon. Inhibition by monochlorodimedon was competitive with Cl-. From these results, and the ability of myeloperoxidase to slowly peroxidase monochlorodimedon in the absence of Cl-, we propose that the reaction of monochlorodimedon with the myeloperoxidase/H2O2/Cl- system involves a major pathway due to hypochlorous acid-dependent chlorination and a minor peroxidative pathway. Only a small fraction of compound I needs to react with monochlorodimedon instead of Cl- at each enzyme cycle, for compound II to rapidly accumulate. Monochlorodimedon, therefore, cannot be regarded as an inert detector of hypochlorous acid production by myeloperoxidase, but acts to limit the chlorinating activity of the enzyme. In the presence of reducing species that act like monochlorodimedon, the activity of myeloperoxidase would depend on the rate of turnover of compound II. Components of human serum promoted the conversion of ferric-myeloperoxidase to compound II in the presence of H2O2. We suggest, therefore, that in vivo the rate of turnover of compound II may determine the rate of myeloperoxidase-dependent production of hypochlorous acid by stimulated neutrophils.","pmid":"2847800","doi":"10.1016/0167-4838(88)90271-3","url":"https://pubmed.ncbi.nlm.nih.gov/2847800/"},{"id":3250,"title":"Inactivation of biofilm bacteria.","authors":"LeChevallier, M W; Cawthon, C D; Lee, R G","year":1988,"date":"1988 Oct","journal":"Applied and environmental microbiology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"The current project was developed to examine inactivation of biofilm bacteria and to characterize the interaction of biocides with pipe surfaces. Unattached bacteria were quite susceptible to the variety of disinfectants tested. Viable bacterial counts were reduced 99% by exposure to 0.08 mg of hypochlorous acid (pH 7.0) per liter (1 to 2 degrees C) for 1 min. For monochloramine, 94 mg/liter was required to kill 99% of the bacteria within 1 min. These results were consistent with those found by other investigators. Biofilm bacteria grown on the surfaces of granular activated carbon particles, metal coupons, or glass microscope slides were 150 to more than 3,000 times more resistant to hypochlorous acid (free chlorine, pH 7.0) than were unattached cells. In contrast, resistance of biofilm bacteria to monochloramine disinfection ranged from 2- to 100-fold more than that of unattached cells. The results suggested that, relative to inactivation of unattached bacteria, monochloramine was better able to penetrate and kill biofilm bacteria than free chlorine. For free chlorine, the data indicated that transport of the disinfectant into the biofilm was a major rate-limiting factor. Because of this phenomenon, increasing the level of free chlorine did not increase disinfection efficiency. Experiments where equal weights of disinfectants were used suggested that the greater penetrating power of monochloramine compensated for its limited disinfection activity. These studies showed that monochloramine was as effective as free chlorine for inactivation of biofilm bacteria. The research provides important insights into strategies for control of biofilm bacteria.","pmid":"2849380","doi":"10.1128/aem.54.10.2492-2499.1988","url":"https://pubmed.ncbi.nlm.nih.gov/2849380/"},{"id":3252,"title":"The inhibition of bacterial growth by hypochlorous acid. Possible role in the bactericidal activity of phagocytes.","authors":"McKenna, S M; Davies, K J","year":1988,"date":"1988 Sep 15","journal":"The Biochemical journal","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The 'respiratory burst' of phagocytes such as neutrophils generates superoxide which forms H2O2 by dismutation. H2O2 and Cl- ions serve as substrates for the enzyme myeloperoxidase to generate hypochlorous acid (HOCl). HOCl is thought to play an important role in bacterial killing, but its mechanism of action is not well characterized. Furthermore, although many studies in vitro have shown HOCl to be a damaging oxidant with little or no specificity (particularly at high concentrations), bacteria which have been ingested by phagocytes appear to experience a rapid and selective inhibition of cell division. Bacterial membrane disruption, protein degradation, and inhibition of protein synthesis, do not seem to occur in the early phases of phagocyte action. We have now found that low concentrations of HOCl exert a rapid and selective inhibition of bacterial growth and cell division, which can be blocked by taurine or amino acids. Only 20 microM-HOCl was required for 50% inhibition of bacterial growth (5 x 10(8) Escherichia coli/ml), and 50 microM-HOCl completely inhibited cell division (colony formation). These effects were apparent within 5 min of HOCl exposure, and were not reversed by extensive washings. DNA synthesis (incorporation of [3H]-thymidine) was significantly affected by even a 1 min exposure to 50 microM-HOCl, and decreased by as much as 96% after 5 min. In contrast, bacterial membrane disruption and extensive protein degradation/fragmentation (release of acid-soluble counts from [3H]leucine-labelled cells) were not observed at concentrations below 5 mM-HOCl. Protein synthesis (incorporation of [3H]leucine) was only inhibited by 10-30% following 5 min exposure to 50 microM-HOCl, although longer exposure produced more marked reductions (80% after 30 min). Neutrophils deficient in myeloperoxidase cannot convert H2O2 to HOCl, yet can kill bacteria. We have found that H2O2 is only 6% as effective as HOCl in inhibiting E. coli growth and cell division (0.34 mM-H2O2 required for 50% inhibition of colony formation), and taurine or amino acids do not block this effect. Our results are consistent with a rapid and selective inhibition of bacterial cell division by HOCl in phagocytes. H2O2 may substitute for HOCl in myeloperoxidase deficiency, but by a different mechanism and at a greater metabolic cost.","pmid":"2848494","doi":"10.1042/bj2540685","url":"https://pubmed.ncbi.nlm.nih.gov/2848494/"},{"id":3254,"title":"Reactions of hypochlorite with catalase.","authors":"Mashino, T; Fridovich, I","year":1988,"date":"1988 Aug 31","journal":"Biochimica et biophysica acta","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"OCl-/HOCl imposed a rapid inactivation of catalase (hydrogen-peroxide: hydrogen-peroxide oxidoreductase, EC 1.11.1.6), some of which was slowly reversible upon subsequent exposure to H2O2. Ethanol accelerated this restoration of activity by H2O2. OCl- caused biphasic changes in the visible absorption spectrum of catalase, which were partially reversed by dithionite. A scheme of reactions involving axial ligation of one or two OCl- to heme iron, followed by heterolytic or homolytic cleavages of the O-Cl bond, is proposed to account for the behavior of the system.","pmid":"2841981","doi":"10.1016/0167-4838(88)90298-1","url":"https://pubmed.ncbi.nlm.nih.gov/2841981/"},{"id":3256,"title":"Preparation of bacteriologically safe bicarbonate concentrate for hemodialysis.","authors":"Ruderman, M A; Yungbluth, M M; del Greco, F; Krumlovsky, F A; Beske, R G","year":1988,"date":"1988 Jul-Sep","journal":"ASAIO transactions","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"To determine whether bacteriologic hazards associated with bicarbonate concentrate may be reduced or prevented, evaluation of a system consisting of a mixing tank supplied with R.O. water and two separate storage tanks was undertaken. Bicarbonate was mixed on a schedule specific to usage and dispensed to the storage tanks from which it was drawn off into 2.5 gallon jugs for each treatment. The mixing tank was disinfected with hypochlorite solution (200 ppm) before each use. Storage tanks and 2.5 gallon jugs were disinfected weekly and sampled immediately before scheduled disinfection and after the longest storage time. The mixing tank was sampled for corresponding batches. A 1 ml inoculum of concentrate was plated onto tryptic soy sheep blood agar, incubated for 48 hours at 35 degrees C and colony counts/ml recorded. A total of 225 batches on a 10% sampling schedule were monitored. All cultures have grown less than 50 cfu/ml, which is less than AAMI standards for maximum allowable level for water and dialysate. Bacteriologically safe bicarbonate concentrate can be reliably produced using R.O. water, controlled storage times, and rigid disinfection schedules.","pmid":"2848564","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/2848564/"},{"id":3257,"title":"Superoxide modulates the activity of myeloperoxidase and optimizes the production of hypochlorous acid.","authors":"Kettle, A J; Winterbourn, C C","year":1988,"date":"1988 Jun 1","journal":"The Biochemical journal","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Myeloperoxidase catalyses the conversion of H2O2 and Cl- to hypochlorous acid (HOCl). It also reacts with O2- to form the oxy adduct (compound III). To determine how O2- affects the formation of HOCl, chlorination of monochlorodimedon by myeloperoxidase was investigated using xanthine oxidase and hypoxanthine as a source of O2- and H2O2. Myeloperoxidase was mostly converted to compound III, and H2O2 was essential for chlorination. At pH 5.4, superoxide dismutase (SOD) enhanced chlorination and prevented formation of compound III. However, at pH 7.8, SOD inhibited chlorination and promoted formation of the ferrous peroxide adduct (compound II) instead of compound III. We present spectral evidence for a direct reaction between compound III and H2O2 to form compound II, and for the reduction of compound II by O2- to regenerate native myeloperoxidase. These reactions enable compound III and compound II to participate in the chlorination reaction. Myeloperoxidase catalytically inhibited O2- -dependent reduction of Nitro Blue Tetrazolium. This inhibition is explained by myeloperoxidase undergoing a cycle of reactions with O2-, H2O2 and O2-, with compounds III and II as intermediates, i.e., by myeloperoxidase acting as a combined SOD/catalase enzyme. By preventing the accumulation of inactive compound II, O2- enhances the activity of myeloperoxidase. We propose that, under physiological conditions, this optimizes the production of HOCl and may potentiate oxidant damage by stimulated neutrophils.","pmid":"2843172","doi":"10.1042/bj2520529","url":"https://pubmed.ncbi.nlm.nih.gov/2843172/"},{"id":3273,"title":"Action of hypochlorous acid on the antioxidant protective enzymes superoxide dismutase, catalase and glutathione peroxidase.","authors":"Aruoma, O I; Halliwell, B","year":1987,"date":"1987 Dec 15","journal":"The Biochemical journal","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"The neutrophil enzyme myeloperoxidase generates hypochlorous acid (HOCl) at sites of inflammation. Glutathione peroxidase is very quickly inactivated by low concentration of HOCl. Inactivation of catalase is also rapid, but requires higher HOCl concentrations and the haem appears to be degraded. Inactivation of bovine CuZn superoxide dismutase is slower. Hence superoxide dismutase should not be easily inactivated by HOCl at sites of inflammation, which may contribute to its effectiveness as an anti-inflammatory agent and in minimizing reperfusion injury.","pmid":"2829848","doi":"10.1042/bj2480973","url":"https://pubmed.ncbi.nlm.nih.gov/2829848/"},{"id":3274,"title":"Augmentation of neutrophil-mediated erythrocyte lysis by cells derived in vitro from human monocytes.","authors":"Dallegri, F; Ballestrero, A; Frumento, G; Patrone, F","year":1987,"date":"1987 Dec","journal":"Blood","category":"Food & agriculture","evidence":"In vitro / laboratory","relevance":"High","abstract":"Neutrophilic polymorphonuclear leukocytes (PMNs) were incubated with opsonized zymosan and lysed human erythrocytes (RBCs) as measured by a 51Cr release method. Conversely, myeloperoxidase (MPO)-negative hydrogen peroxide (H2O2)-generating cells, derived in vitro from human monocytes (monocyte-derived cells (MDCs), were ineffective per se but capable of augmenting the lysis by PMNs. The lysis by PMNs and PMNs plus MDCs was inhibited by catalase, azide, taurine, and alanine, consistent with the requirement for hypochlorous acid (HOCl). As detected under conditions similar to those used for lytic assays, MDCs failed to produce HOCl but augmented the HOCl recovery from the PMN-RBC system. Moreover, when the extent of the lysis was plotted as a function of the HOCl recovery, a positive linear relationship was found. Although the actual size of the H2O2 extracellular pool could not be measured because of the inexistence of a reliable assay to probe our cytolytic model without perturbing the equilibrium of the system, the results presented suggest that MDCs enhance the PMN-mediated lysis by improving the HOCl production, presumably by supplying extra amounts of H2O2 to be handled by PMN MPO. In fact, the events mediated by MDCs could be reproduced by using an appropriate H2O2-generating enzymatic system (glucose-glucose oxidase). The present study provides direct evidence for the possibility of cooperation between MPO-positive and MPO-negative phagocytes in exerting functions (HOCl production and, in turn, cytolysis) possibly relevant to the outcome of inflammatory processes.","pmid":"2823935","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/2823935/"},{"id":3280,"title":"Hypochlorous acid-promoted loss of metabolic energy in Escherichia coli.","authors":"Barrette, W C Jr; Albrich, J M; Hurst, J K","year":1987,"date":"1987 Oct","journal":"Infection and immunity","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Oxidation of Escherichia coli by hypochlorous acid (HOCl) or chloramine (NH2Cl) gives rise to massive hydrolysis of cytosolic nucleotide phosphoanhydride bonds, although no immediate change occurs in either the nucleotide pool size or the concentrations of extracellular end products of AMP catabolism. Titrimetric curves of the extent of hydrolysis coincide with curves for loss of cell viability, e.g., reduction in the adenylate energy charge from 0.8 to 0.1-0.2 accompanies loss of 99% of the bacterial CFU. The oxidative damage caused by HOCl is irreversible within 100 ms of exposure of the organism, although nucleotide phosphate bond hydrolysis requires several minutes to reach completion. Neither HOCl nor NH2Cl reacts directly with nucleotides to hydrolyze phosphoanhydride bonds. Loss of viability is also accompanied by inhibition of induction of beta-galactosidase. The proton motive force, determined from the distribution of 14C-radiolabeled lipophilic ions, declines with incremental addition of HOCl after loss of respiratory function; severalfold more oxidant is required for the dissipation of the proton motive force than for loss of viability. These observations establish a causal link between loss of metabolic energy and cellular death and indicate that the mechanisms of oxidant-induced nucleotide phosphate bond hydrolysis are indirect and that they probably involve damage to the energy-transducing and transport proteins located in the bacterial plasma membrane.","pmid":"2820883","doi":"10.1128/iai.55.10.2518-2525.1987","url":"https://pubmed.ncbi.nlm.nih.gov/2820883/"},{"id":3281,"title":"Oxidative killing of Aspergillus fumigatus proceeds by parallel myeloperoxidase-dependent and -independent pathways.","authors":"Washburn, R G; Gallin, J I; Bennett, J E","year":1987,"date":"1987 Sep","journal":"Infection and immunity","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"The relative importance of several oxygen intermediates in fungicidal action against opsonized Aspergillus fumigatus conidia was investigated with monocytes from normal volunteers and patients with either chronic granulomatous disease or myeloperoxidase (MPO) deficiency. Results from experiments in which catalase, taurine, mannitol, or glucose-glucose oxidase were added to these phagocytes indicated that the MPO-hydrogen peroxide-halide system and an MPO-independent oxidative system exerted comparable conidiacidal activity. These findings offer a plausible explanation for the susceptibility of patients with chronic granulomatous disease to invasive Aspergillus infections; their phagocytes fail to generate hydrogen peroxide, a substrate necessary for both systems. Patients with MPO deficiency are not known to be predisposed to invasive aspergillosis, suggesting that an MPO-independent oxidative system may provide an alternative mechanism for the oxidative killing of Aspergillus spp.","pmid":"3040589","doi":"10.1128/iai.55.9.2088-2092.1987","url":"https://pubmed.ncbi.nlm.nih.gov/3040589/"},{"id":3284,"title":"Mutagenic activity of chloramines.","authors":"Thomas, E L; Jefferson, M M; Bennett, J J; Learn, D B","year":1987,"date":"1987 May","journal":"Mutation research","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Mutagenesis by chloramines and hypochlorous acid (HOCl) was studied to determine whether these agents could contribute to the mutagenic and potentially carcinogenic activity of stimulated leukocytes and whether environmental exposure to these agents is a cause for concern. Mutagenic activity was measured using the S. typhimurium TA97a, TA100 and TA102 tester strains. Because chloramines and HOCl are bactericidal, react rapidly with cell components, and can destroy the histidine and biotin required for the mutagenesis assay, activity can't be compared directly with that of less toxic or reactive agents. Nevertheless, chloramines were mutagenic when tested under appropriate conditions. TA100 was the most sensitive strain, and the most active mutagens were lipophilic dichloramines (RNCl2) including derivatives of histamine, ethanolamine and putrescine. Lipophilic monochloramines (RNHCl) such as histamine-monochloramine and NH2Cl were less active. Hydrophilic chloramines such as taurine-chloramines had low activity, and HOCl was inactive. The metabolic state of the bacteria was critical. Chloramines were mutagenic when added to bacteria with glucose at 37 degrees C, but killing predominated when chloramines were added at 4 degrees C or 25 degrees C, or at 37 degrees C without glucose. Production of chloramines and HOCl by leukocytes in vivo could contribute to the association of chronic inflammation and cancer as a result of: (1) the entry of membrane-permeable chloramines into normal cells followed by attack on intracellular components including DNA, and (2) the production of secondary mutagens such as compounds with carbonyl groups or carbon-chlorine bonds. On the other hand, chlorination of water supplies is perhaps more likely to destroy than create mutagens, and chloramines from the environment are unlikely to penetrate the skin and mucous membranes.","pmid":"3033493","doi":"10.1016/0165-1218(87)90112-1","url":"https://pubmed.ncbi.nlm.nih.gov/3033493/"},{"id":3293,"title":"On the mechanism of chlorination by chloroperoxidase.","authors":"Dunford, H B; Lambeir, A M; Kashem, M A; Pickard, M","year":1987,"date":"1987 Jan","journal":"Archives of biochemistry and biophysics","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Spectral-scan results obtained on the millisecond time scale are reported for reactions of chloroperoxidase with peracetic acid and chloride ion in both the presence and the absence of monochlorodimedone. A multimixing experiment is performed in which stoichiometric amounts of chloroperoxidase and peracetic acid are premixed for 0.7 s before the resultant compound I is reacted with chloride ion. The combined results show that the only detectable enzyme intermediate species is compound I (except in very late stages of the reaction), that the disappearance of compound I is accelerated by the presence of chloride ion, and that it is further accelerated if both chloride and monochlorodimedone are present. It is concluded that compound I is an obligate intermediate species in the reaction. Experiments are performed on the reaction of monochlorodimedone with hypochlorous acid in both the presence and the absence of added chloride ion, but in the absence of chloroperoxidase. The presence of chloride ion greatly accelerates the reaction rate apparently by setting off a chlorine chain reaction. This reaction would be important in the enzyme-catalyzed reaction if hypochlorous acid were liberated into the solution. A careful analysis of steady-state kinetic results shows that in the chlorination of monochlorodimedone at least, liberation of free hypochlorous acid is not important in the enzyme-catalyzed pathway. Rather the reaction proceeds from compound I to formation of iron(III)-OCl by chloride ion addition to the ferryl oxygen atom. This obligate intermediate species then chlorinates the substrate. It is well described as enzyme-activated hypochlorous acid, in which replacement of the proton in HOCl by the heme iron ion produces a Cl+ species of great potency. Thus the enzyme controls chlorination of monochlorodimedone rather than unleashing an uncontrolled chain reaction in which it would be rapidly destroyed.","pmid":"3028259","doi":"10.1016/0003-9861(87)90034-8","url":"https://pubmed.ncbi.nlm.nih.gov/3028259/"},{"id":3294,"title":"A surface test for virucidal activity of disinfectants: preliminary study with herpes virus.","authors":"Tyler, R; Ayliffe, G A","year":1987,"date":"1987 Jan","journal":"The Journal of hospital infection","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"A test was developed to assess the surface activity of disinfectants against dried viral preparations. In this preliminary study a variety of disinfectants was tested against herpes virus. The results showed that 2% alkaline glutaraldehyde and 70% ethanol or isopropanol were effective in 1 min. Hypochlorite solutions (2500 ppm av. Cl2) were effective in 5 min, but povidone-iodine (10%) was slower in action and a clear soluble phenol showed uncertain activity at 5 and 10 min. High concentrations of alcohols (above 95%), two quaternary ammonium compounds and 0.5% aqueous chlorhexidine showed little activity in 10 min.","pmid":"2880894","doi":"10.1016/0195-6701(87)90090-9","url":"https://pubmed.ncbi.nlm.nih.gov/2880894/"},{"id":3296,"title":"Hypochlorous acid-activated carbon: an oxidizing agent capable of producing hydroxylated polychlorinated biphenyls.","authors":"Voudrias, E A; Larson, R A; Snoeyink, V L; Chen, A S; Stapleton, P L","year":1986,"date":"1986 Nov","journal":"Environmental health perspectives","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Granular activated carbon (GAC), in the presence of dilute aqueous hypochlorite solutions typical of those used in water treatment, was converted to a reagent capable of carrying out free-radical coupling reactions and other oxidations of dilute aqueous solutions of phenols. The products included biphenyls with chlorine and hydroxyl substitution (hydroxylated polychlorinated biphenyls). For example, 2,4-dichlorophenol, a common constituent of wastewaters and also natural waters treated with hypochlorite, was converted to 3,5,5'trichloro-2,4'-dihydroxybiphenyl and several related compounds in significant amounts. It is possible that these products pose more of a health hazard than either the starting phenols or the unhydroxylated polychlorinated biphenyl derivatives.","pmid":"3028770","doi":"10.1289/ehp.866997","url":"https://pubmed.ncbi.nlm.nih.gov/3028770/"},{"id":3297,"title":"Epidermal hyperplasia in mouse skin following treatment with alternative drinking water disinfectants.","authors":"Robinson, M; Bull, R J; Schamer, M; Long, R E","year":1986,"date":"1986 Nov","journal":"Environmental health perspectives","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Female SENCAR mice were treated with aqueous solutions of hypochlorous acid (HOCl), sodium hypochlorite (NaOCl), chlorine dioxide (ClO2), and monochloramine (NH2Cl) by whole body exposure (except head) for a 10-min period for 4 days in the first experiment and for 1 day (except NH2Cl) in the second experiment. Animals were sacrificed the day following the last treatment (experiment 1) or on day 1, 2, 3, 4, 5, 8, 10, and 12 following treatment (experiment 2), and skin thickness was measured by light microscopy at X400 by use of an eyepiece micrometer. Concentrations of disinfectants were 1, 10, 100, 300, and 1000 mg/L, for experiment 1 and 1000 mg/L for experiment 2. Thickness of the interfollicular epidermis (IFE) for control animals was 15.4 +/- 1.5 micron. After 4 days of treatment at 1000 mg/L, HOCl and ClO2 increased thickness to 39 +/- 7.0 and 40.2 +/- 11.8, and NaOCl increased thickness to 25.2 +/- 6.1 micron. Only HOCl and ClO2 were tested at 300 mg/L, yielding an IFE thickness of 30.0 +/- 13.1 and 16.8 +/- 0.8 micron, respectively. The response to HOCl was found to be dose-related; the minimally effective dose was 100 mg/L. In earlier, preliminary tests to determine optimum treatment schedule, the response to HOCl appeared to be maximal after 4 days of treatment and tended to decrease with further treatment. The time-course study following a single treatment of 1000 mg/L HOCl, however, showed a progression of IFE thickening of from 18.3 +/- 1.4 at 1 day to 30.8 +/- 8.0 at 8 days, decreasing to 19.1 +/- 6.2 micron at 12 days.(ABSTRACT TRUNCATED AT 250 WORDS)","pmid":"3028769","doi":"10.1289/ehp.8669293","url":"https://pubmed.ncbi.nlm.nih.gov/3028769/"},{"id":3305,"title":"Role of hypochlorous acid and chloramines in the extracellular cytolysis by neutrophil polymorphonuclear leukocytes.","authors":"Dallegri, F; Ballestrero, A; Frumento, G; Patrone, F","year":1986,"date":"1986 May","journal":"Journal of clinical & laboratory immunology","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"The lysis of human red blood cells (HRBC) by neutrophil polymorphonuclear leukocytes (PMN), triggered with opsonized zymosan (OPZ) particles, was inhibited by azide, catalase, Cl- -free medium and amino acids indicating the involvement of myeloperoxidase (MPO), hydrogen peroxide (H2O2), Cl- ions and hypochlorous acid (HOCl) respectively. Thus, the cytolytic process depends on the following reaction: (Formula: see text). Because the oxidizing agent HOCl is also the precursor of the chloramines, a group of oxidants formed by the reaction between HOCl and PMN-derived ammonia (NH4+) or amines (R-NH2), the observed HRBC lysis can be theoretically due to HOCl and/or chloramines. Nevertheless, we found that PMN-mediated cytotoxicity occurs as an unidirectional process, being HRBC targets lysed and PMN unaffected. This finding indicates that the cytotoxin must be relatively more efficient against HRBC as compared with PMN. In fact, reagent HOCl (used at concentrations comparable to those generated by PMN) but not chloramines displayed such a type of property. Taken together, the data suggest that HRBC are killed by PMN-derived HOCl without the requirement for chloramines: this implies that NH4+ and R-NH2, released by PMN, act as down-modulators of the cytotoxic process, serving as HOCl trapping agents.","pmid":"3016275","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/3016275/"},{"id":3306,"title":"The kinetics of dissolution of tooth enamel--a constant composition study.","authors":"Chen, W C; Nancollas, G H","year":1986,"date":"1986 May","journal":"Journal of dental research","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"The kinetics of dissolution of powdered bovine enamel and of human enamel, both untreated and extracted with either hypochlorite or chloroform, has been studied using a constant solution composition technique in undersaturated solutions of calcium phosphate (total molar calcium concentration, TCa = 0.3 to 13.1 X 10(-3) mol L-1, total molar phosphate, Tp = 0.18 to 7.9 X 10(-3) mol L-1) at an ionic strength of 0.15 mol L-1, and pH = 4.5. The kinetic equations describing the dissolution reactions suggest a surface dislocation mechanism, and the presence of fluoride ion markedly retarded the reaction. For human enamel, a fluoride level of only 0.5 ppm reduced the rate of dissolution ten-fold. In contrast, the dissolution of hydroxyapatite, HAP, is best interpreted in terms of a polynucleation process.","pmid":"3009579","doi":"10.1177/00220345860650050601","url":"https://pubmed.ncbi.nlm.nih.gov/3009579/"},{"id":3307,"title":"Inhibition of neutrophil cytolysin production by target cells.","authors":"Dallegri, F; Patrone, F; Ballestrero, A; Frumento, G; Sacchetti, C","year":1986,"date":"1986 May","journal":"Blood","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"Neutrophils, triggered by heat-aggregated human IgG (Agg.IgG), were found to lyse chicken red blood cells (CRBC) as determined by a 51Cr release method. The lysis was inhibited by azide, catalase, chloride-free medium and amino acids, suggesting the requirement for myeloperoxidase (MPO), hydrogen peroxide (H2O2), chloride ions (Cl-), and hypochlorous acid (HOC1), respectively. These results indicate that neutrophils lyse CRBC through an HOCl-(ie, MPO-H2O2-Cl-) dependent process. Although HOCl can react with neutrophil-derived nitrogenous (N-) compounds to yield chloramines, the main and well-characterized chloramines did not play a direct role in the lysis of CRBC in our model system. Thus, it appears that lysis is due either to HOCl or to an unknown compound derived from and with characteristics similar to HOCl. When CRBC were replaced with HRBC targets, no lysis could be observed. Treatment of HRBC with carmustine, to inhibit the glutathione cycle, did not affect the cell resistance to lysis by neutrophils. Conversely, the inhibition of HRBC catalase activity with aminotriazole (AT) made the cells susceptible to neutrophil-mediated HOCl-dependent lysis: this suggests that HRBC escape lysis by neutrophils through an AT-inhibitable, ie catalase-dependent, process. Through an identical catalase-dependent process, HRBC were capable of efficiently preventing the H2O2 and HOCl recovery from Agg.IgG-triggered neutrophils, tested under experimental conditions similar to those used for cytolytic assays. Together, these data suggest that HRBC targets, endowed with high catalase activity, escape neutrophil-mediated lysis by consuming (by catalase) neutrophil-derived H2O2, so that HOCl cannot be produced in amounts sufficient to promote lysis. Parallel experiments, performed with AT-treated CRBC, showed that these cells, endowed with a relatively low catalase content, only partially limit neutrophil cytolytic efficiency by a process qualitatively similar to that observed with HRBC targets. The results provide evidence that target cells can restrain neutrophil cytolytic efficiency by interfering with the MPO-H2O2-Cl system through their catalase activity.","pmid":"3008887","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/3008887/"},{"id":3311,"title":"Copper ions and hydrogen peroxide form hypochlorite from NaCl thereby mimicking myeloperoxidase.","authors":"Frenkel, K; Blum, F; Troll, W","year":1986,"date":"1986","journal":"Journal of cellular biochemistry","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"Sea urchins have elaborated multiple defenses to assure monospermic fertilization. In this work, we have concentrated on a study of the mechanism(s) by which hydrogen peroxide (H2O2) prevents polyspermy in Arbacia punctulata. We found that it is not H2O2 but probably hypochlorous acid/hypochlorite (HOCl/OCl-) derived from H2O2 that is toxic to the supernumerary sperm. The spermicidal activity of H2O2 is potentiated by at least one order of magnitude by cupric ions (Cu2+). This increased toxicity is not due to the formation of hydroxyl radicals (.OH) because .OH scavengers did not counteract the activity of Cu2+. Moreover, substitution of Cu2+ by ferrous ions (Fe2+), which are known to cause formation of .OH from H2O2, had no effect on fertilization even at 10(2)-10(3) times higher concentrations. In contrast, 3-amino-1,2,4-triazole (AT), and HOCl/OCl- scavenger, totally reversed the toxic effects of Cu2+. Furthermore, we found that HOCl/OCl- is generated in solutions of H2O2 and Cu2+ in the presence of 0.5 M NaCl and that its accumulation is abolished by AT. Thus it is possible that the antifertility properties of copper are due to its ability to mediate formation of HOCl/OCl-. HOCl/OCl- generated by Cu2+ from H2O2 and Cl-, a low concentration of exogenously added HOCl/OCl-, or increased concentrations of H2O2 has similar inhibitory effects on the fertilization process in sea urchins. Therefore, we suggest that polyspermy is prevented by the action of a myeloperoxidase that affects the formation of HOCl/OCl- from the Cl- present in sea water through reaction with H2O2 generated by the newly fertilized egg.","pmid":"3009503","doi":"10.1002/jcb.240300302","url":"https://pubmed.ncbi.nlm.nih.gov/3009503/"},{"id":3312,"title":"Effect of temperature on production of hypochlorous acid by stimulated human neutrophils.","authors":"Severns, C; Collins-Lech, C; Sohnle, P G","year":1986,"date":"1986 Jan","journal":"The Journal of laboratory and clinical medicine","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Under natural conditions or because of therapy with heat or cold, neutrophils may function at times in the human body at temperatures other than 37 degrees C. Therefore, we evaluated the effects of temperature on several functions of these cells. Phagocytosis and superoxide production by stimulated neutrophils were optimal at 37 degrees C and attained at least 70% of this peak value at 42 degrees C. In contrast, production of hypochlorous acid (as measured by an assay using the chlorination of taurine) by stimulated neutrophils was optimal at temperatures less than 37 degrees C and attained only 13% to 15% of this peak value at 42 degrees C. During a 2-hour incubation, the major suppressive effects of the higher temperature occurred during the second hour. This result was not explainable by factors related to the hypochlorous acid assay system or by loss of cell viability or myeloperoxidase activity in the cell supernatants, but rather appeared to be caused by reduced generation of hydrogen peroxide at the higher temperatures. Because the extracellular release of a strong oxidant such as hypochlorous acid might result in significant tissue injury, suppression of the release of this oxidant by elevated temperatures may explain why the application of local heat sometimes benefits certain inflammatory conditions.","pmid":"3001209","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/3001209/"},{"id":3315,"title":"Use of nitrite and hypochlorite treatments in determination of the contributions of IQ-type and non-IQ-type heterocyclic amines to the mutagenicities in crude pyrolyzed materials.","authors":"Tsuda, M; Negishi, C; Makino, R; Sato, S; Yamaizumi, Z; Hirayama, T; Sugimura, T","year":1985,"date":"1985 Dec","journal":"Mutation research","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"The mutagenic heterocyclic amines Glu-P-2, MeA alpha C and Phe-P-1, which possess a 2-aminopyridine structure in their molecule (non-IQ-type mutagens), were found to be inactivated by nitrite treatment under acidic conditions, as observed previously with Trp-P-1, Trp-P-2, Glu-P-1 and A alpha C. In contrast, MeIQx, 4,8- and 7,8-DiMeIQx, which were originally isolated from fried beef or heated model mixtures of creatinine, amino acids and glucose, and which have a 2-aminoimidazole moiety in their molecules (IQ-type mutagens), were very resistant to nitrite treatment like IQ and MeIQ. Both types of mutagenic heterocyclic amines were completely inactivated by treatment with hypochlorite. This differential inactivation of mutagenic heterocyclic amines by nitrite and hypochlorite was used in determination of the contributions of IQ-type and non-IQ-type mutagens to the total mutagenicities of various pyrolyzed materials. The percentage contributions of IQ-type mutagens to the mutagenicities of broiled sardine, fried beef, broiled horse mackerel, cigarette smoke condensate and albumin tar were 88, 75, 48, 6 and 4, respectively.","pmid":"2997601","doi":"10.1016/0165-1161(85)90002-0","url":"https://pubmed.ncbi.nlm.nih.gov/2997601/"},{"id":3318,"title":"A comparative study of neutrophil purification and function.","authors":"Grisham, M B; Engerson, T D; McCord, J M; Jones, H P","year":1985,"date":"1985 Oct 10","journal":"Journal of immunological methods","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Several different methods are currently used by numerous laboratories for the isolation of human neutrophils. These methods include partial purification by dextran sedimentation followed by water lysis, and more complete purification procedures utilizing discontinuous density gradients coupled with dextran sedimentation and in some cases hypotonic lysis. Some investigators refrain from using certain purification schemes because certain steps or reagents used in a particular method might adversely affect the functional parameter of the neutrophil they wish to measure. In spite of these concerns there has been no systematic comparison of the functional status of neutrophils prepared by the various methodologies. In this study we have compared 4 commonly used methods of isolation with neutrophil function. The results of this study indicate that while neutrophil yield and purity were determined by isolation procedure, all cells were equivalent with regard to chemotactic performance, ability to degranulate, and ability to produce superoxide and hypochlorous acid.","pmid":"2995497","doi":"10.1016/0022-1759(85)90363-1","url":"https://pubmed.ncbi.nlm.nih.gov/2995497/"},{"id":3322,"title":"Resistance of leishmanial phosphatases to inactivation by oxygen metabolites.","authors":"Saha, A K; Das, S; Glew, R H; Gottlieb, M","year":1985,"date":"1985 Sep","journal":"Journal of clinical microbiology","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"Leishmania donovani promastigotes produce large quantities of two distinct acid phosphatases; a tartrate-resistant enzyme is localized to the external surface of the plasma membrane, and a tartrate-sensitive enzyme is secreted into the growth medium. It was shown previously that preincubation of human neutrophils and macrophages with the tartrate-resistant phosphatase markedly reduced the ability of these host cells to produce superoxide anions in response to stimulation with the activator formyl-methionyl-leucyl-phenylalanine. The possibility that the cell surface acid phosphatase or the phosphatase that is secreted into the extracellular fluid might compromise other host cell functions, especially intracellular ones, depends on the ability of the enzyme to resist exposure to toxic oxygen metabolites (e.g., superoxide anion, hydrogen peroxide, hypochlorite) generated by phagocytic cells. In the present report, we show that both leishmanial acid phosphatases were relatively resistant to inactivation by oxygen metabolites. At pH 5.5, the activity of the tartrate-resistant phosphatase was reduced 50% by incubation for 1 h with each of the following: 30 mM O2-, 500 mM hydrogen peroxide, and 6 mM hypochlorite ion. These concentrations are many fold greater than the concentrations of these substances that are generated by stimulated polymorphonuclear phagocytes. The tartrate-sensitive acid phosphatase differed markedly from the tartrate-resistant phosphatase in that the former was essentially insensitive to even very high concentrations of superoxide anion and hydrogen peroxide. Furthermore, 50% inactivation of the tartrate-sensitive leishmanial phosphatase required exposure to 35 mM hypochlorite for 30 min. These results indicate that the catalytic potential of these two leishmanial acid phosphatases probably survives exposure to toxic oxygen metabolites generated by neutrophils and macrophages.","pmid":"2995435","doi":"10.1128/jcm.22.3.329-332.1985","url":"https://pubmed.ncbi.nlm.nih.gov/2995435/"},{"id":3324,"title":"Mechanisms of resistance of Aspergillus fumigatus Conidia to killing by neutrophils in vitro.","authors":"Levitz, S M; Diamond, R D","year":1985,"date":"1985 Jul","journal":"The Journal of infectious diseases","category":"Water, sanitation & biosecurity","evidence":"In vitro / laboratory","relevance":"High","abstract":"Despite the critical role for neutrophils in host defenses against invasive aspergillosis, previous studies have established that neutrophils are unable to kill resting conidia of Aspergillus fumigatus. The mechanisms of resistance of the conidia were therefore investigated. Electron microscopy studies showed the fusion of phagosomes containing A. fumigatus conidia with lysosomes of the neutrophil. Resting conidia of A. fumigatus were then compared with those that had been preincubated in broth until swollen, but not germinated, as well as with blastospores of Candida albicans (two fungal forms that are killed by neutrophils) and zymosan particles. Despite comparable susceptibility to phagocytosis, resting conidia of A. fumigatus stimulated production of significantly less superoxide anion, hydrogen peroxide, and hypochlorous acid and induced less myeloperoxidase-dependent iodination by neutrophils than did the preincubated conidia of A. fumigatus, blastospores of C. albicans, or zymosan particles. In addition, resting conidia of A. fumigatus were relatively resistant to cell-free killing by oxidants presumed to be generated by neutrophils. Thus, resistance of resting conidia of A. fumigatus to neutrophil fungicidal mechanisms appears to be secondary to both failure of the conidia to stimulate an optimal respiratory burst as well as resistance of the conidia to neutrophil oxidants. However, the reversal of this resistance by preincubation of the conidia suggests that neutrophils still may form an important host defense against the conidia of A. fumigatus.","pmid":"2989387","doi":"10.1093/infdis/152.1.33","url":"https://pubmed.ncbi.nlm.nih.gov/2989387/"},{"id":3325,"title":"Comparative reactivities of various biological compounds with myeloperoxidase-hydrogen peroxide-chloride, and similarity of the oxidant to hypochlorite.","authors":"Winterbourn, C C","year":1985,"date":"1985 Jun 18","journal":"Biochimica et biophysica acta","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The reactivities of myeloperoxidase-H2O2-Cl- and sodium hypochlorite with amino acids, uric acid, NADH, ascorbic acid, ADP, albumin, haemoglobin, alpha 1-antitrypsin and some hydroxyl radical scavengers have been compared. The ability of each compound to inhibit chlorination of monochlorodimedon by both oxidants was measured. Relative reaction rates varied over a range of 10(5), but the reactivities of the two oxidants with each compound were very similar, from which it is concluded that the reactions of hypochlorite accurately reflect those of the myeloperoxidase system. Thiol compounds (cysteine and GSH) and methionine were more than 100-times more reactive than other amino acids, which had comparable reactivity to NADH and uric acid. Benzoate, dimethylsulphoxide and formate were very much less reactive. The significance of these reactions of myeloperoxidase in microbial killing and inflammation is discussed.","pmid":"2986713","doi":"10.1016/0304-4165(85)90120-5","url":"https://pubmed.ncbi.nlm.nih.gov/2986713/"},{"id":3328,"title":"Feasibility and efficacy of in-home water chlorination in rural North-eastern Brazil.","authors":"Kirchhoff, L V; McClelland, K E; Do Carmo Pinho, M; Araujo, J G; De Sousa, M A; Guerrant, R L","year":1985,"date":"1985 Apr","journal":"The Journal of hygiene","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The purpose of this study was to assess the feasibility, acceptability and effect of an in-home water chlorination programme in a rural village. Previous studies at this site showed high levels of faecal coliforms in household water, high diarrhoea rates in children, and enterotoxigenic Escherichia coli and rotaviruses were the most common pathogens isolated from patients. Household water came from a pond and was stored in clay pots. No homes had sanitary facilities. A blind, cross-over trial of treatment of household water with inexpensive hypochlorite by a community health worker was carried out over 18 weeks among 20 families. Water in the clay pots was sampled serially, and symptom surveillance was done by medical students. The programme was generally acceptable to the villagers and no change in water use patterns were apparent. The mean faecal coliform level in the chlorinated water was significantly less than in the placebo treated samples (70 vs 16000 organisms/dl, P less than 0.001). People living in houses receiving placebo treatment had a mean of 11.2 days of diarrhoea per year, and the highest rate of 36.7 was among children less than 2 years old. Diarrhoea rates were not significantly different among the participants while exposed to water treated with hypochlorite. We conclude that a low-cost programme of this type, which utilizes community resources, is logistically feasible, appears to be culturally acceptable in this setting, and can result in a marked reduction in water contamination. The lack of effect on diarrhoea rates suggests that improvement in water quality may affect morbidity only when other variables relating to faecal-oral agent transmission are ameliorated at the same time.","pmid":"2985691","doi":"10.1017/s0022172400061374","url":"https://pubmed.ncbi.nlm.nih.gov/2985691/"},{"id":3333,"title":"Factors influencing excystation in Cryptosporidium oocysts from cattle.","authors":"Reduker, D W; Speer, C A","year":1985,"date":"1985 Feb","journal":"The Journal of parasitology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"","pmid":"2984400","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/2984400/"},{"id":3335,"title":"Co-oxidation of luminol by hypochlorite and hydrogen peroxide implications for neutrophil chemiluminescence.","authors":"Brestel, E P","year":1985,"date":"1985 Jan 16","journal":"Biochemical and biophysical research communications","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"Stimulated neutrophils produce several potent oxidants including H2O2, O2- and HOCl. Previous studies have revealed all of these compounds to be capable of oxidizing luminol, a reagent often used to indicate, by its chemiluminescence, the oxidative burst of neutrophils. Data presented in this paper indicate that H2O2 and HOCl spontaneously react at physiologic pH to produce luminol-dependent chemiluminescence 100 times the sum of the chemiluminescence of either reagent alone. This enhancement is due to a co-oxidation by HOCl and H2O2, or to a novel oxidant generated by the interaction of HOCl and H2O2. The HOCl scavenger, taurine, inhibits the chemiluminescence. Evidence is presented against the participation of hydroxyl radical, O2- or singlet oxygen in the oxidation of luminol by HOCl and H2O2. These findings have implications for potential anti-inflammatory compounds.","pmid":"2982377","doi":"10.1016/0006-291x(85)90631-x","url":"https://pubmed.ncbi.nlm.nih.gov/2982377/"},{"id":3336,"title":"Hypochlorite-serum reaction products inhibit porcine vascular endothelial cell growth in culture.","authors":"Papa, L R; McCauley, P T","year":1985,"date":"1985","journal":"Artery","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"In vitro toxicity studies wer initiated in order to determine if chlorination affects vascular endothelial cells. Twelfth to twentieth passage porcine aortic vascular endothelial cells (PAE) were grown to confluency and replated in the presence of complete media (Eagle's minimum essential media supplemented with 20% fetal bovine serum) which had been preincubated for 30 minutes with 15.0 mg/liter chlorine. During a 72-hour exposure period, control PAE cells grew to confluency, an increase of approximately 9 fold in the number of cells/plate. Those cells exposed to media preincubated with 15.0 mg/liter chlorine derived from sodium hypochlorite increased only 6 fold. There was no sign of cell killing, but an apparent inhibition of cell division. No effect was seen when either the amino acid or vitamin component of the complete media was reacted at the 15.0 mg dose level. However, when the serum component was preincubated with 15.0 mg chlorine/liter as sodium hypochlorite, an inhibition in growth rate similar to the complete media occurred.","pmid":"2998305","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/2998305/"},{"id":3338,"title":"Intraperitoneal antiseptics in experimental bacterial peritonitis.","authors":"Platt, J; Jones, R A; Bucknall, R A","year":1984,"date":"1984 Aug","journal":"The British journal of surgery","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"A model of bacterial peritonitis, using mice infected with Escherichia coli, has been used to assess the protective effects of intraperitoneal treatment with antiseptics. Of the five antiseptics tested, only chlorhexidine gluconate had any protective effect, concentrations of 0.05 and 0.02 per cent reducing the mortality to 14 and 50 per cent respectively. The other antiseptics, taurolin, noxytiolin, povidone iodine and hypochlorite were all ineffective. Delayed treatment with chlorhexidine was not as effective as instillation immediately postinfection.","pmid":"6331561","doi":"10.1002/bjs.1800710822","url":"https://pubmed.ncbi.nlm.nih.gov/6331561/"},{"id":3340,"title":"Oxidative mechanisms utilized by human neutrophils to destroy Escherichia coli.","authors":"Passo, S A; Weiss, S J","year":1984,"date":"1984 Jun","journal":"Blood","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Serum-opsonized bacteria are efficiently ingested and killed by neutrophils within the phagocytic vacuole, where they are exposed to an array of reactive oxygen metabolites and toxic lysosomal components. Although bacteria may be destroyed by oxygen-independent mechanisms alone, many types of bacteria are not killed effectively unless they are attacked by oxygen metabolites. However, the apparent inability of extracellular scavengers, or inhibitors, of oxygen metabolites to gain access to the phagocytic vacuole makes this system difficult to evaluate. Therefore, we investigated the ability of neutrophils triggered with phorbol myristate acetate to destroy unopsonized E. coli in a serum-free model system. Neutrophils incubated with phorbol myristate acetate at a cell-to-bacteria ratio of 1:4 caused a greater than 95% reduction in colony-forming units (CFU) of E. coli in 60 min at 37 degrees C. Destruction of E. coli by the stimulated neutrophils was dependent on neutrophil number, stimuli concentration, and the incubation period. The neutrophil-mediated bactericidal effect was stimulated by superoxide dismutase, but was inhibited by catalase, azide, or compounds known to scavenge hypochlorous acid. Although stimulated neutrophils can generate long-lived endogenous N- chloroamines , these compounds did not play a direct role in destruction of E. coli in our model system. However, in the presence of exogenous iodide, endogenous N- chloroamines exerted a powerful bactericidal effect. Finally, neutrophils triggered with opsonized zymosan could also mediate E. coli destruction by a qualitatively similar process. Thus, we have demonstrated that neutrophils have the potential to utilize the myeloperoxidase system to generate bactericidal quantities of a species with characteristics similar to, if not identical with, hypochlorous acid.","pmid":"6326895","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/6326895/"},{"id":3344,"title":"Myeloperoxidase-dependent fluorescein chlorination by stimulated neutrophils.","authors":"Hurst, J K; Albrich, J M; Green, T R; Rosen, H; Klebanoff, S","year":1984,"date":"1984 Apr 25","journal":"The Journal of biological chemistry","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"Hypochlorous acid (HOC1) rapidly chlorinates fluorescein compounds forming, sequentially, the corresponding 4'-chlorofluorescein and 4',5'-dichlorofluoresceins. Chlorination by cell-free myeloperoxidase-catalyzed chloride peroxidation systems gives rise to these compounds as well as variable amounts of isomeric compounds chlorinated in the 2'- and 2',7'-positions. The fluorescence intensity of the dianionic form of the dye is partially quenched upon chlorination, and its proton equilibrium constants are shifted to more acidic values. Fluorescein covalently bound to zymosan (5-isothiocyanatofluorescein-zymosan) also formed these products when the unopsonized particles were incubated with phorbol myristate acetate- or N-formyl-methionyl-leucyl-phenylalanine-stimulated human neutrophils. This reaction was associated with a fall in fluorescence intensity, which was not observed when cells from individuals with chronic granulomatous disease or myeloperoxidase deficiency were used or when azide or catalase were added to the reaction medium. Fluorescent changes accompanying phagocytosis of serum-opsonized 5-isothiocyanatofluorescein-zymosan were also consistent with chlorination of the label; the changes were shown to be myeloperoxidase-dependent by use of myeloperoxidase-deficient or azide-treated cells. Oxidative bleaching of the structurally similar sulfonphthalein dyes by HOCl also occurs at rates which parallel the dye basicities. Results are discussed in relation to the use of fluoresceinated particles and sulfonphthalein dyes in the measurement of intraphagosomal acidification.","pmid":"6325409","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/6325409/"},{"id":3346,"title":"Evaluation of disinfectants in the domestic environment under 'in use' conditions.","authors":"Scott, E; Bloomfield, S F; Barlow, C G","year":1984,"date":"1984 Apr","journal":"The Journal of hygiene","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"An 'in use' test was developed to investigate effectiveness of disinfectant application and of detergent of hot water cleaning at kitchen, bathroom and toilet sites in the domestic environment. Detergent and hot water cleaning produced no observable reduction in microbial contamination. Single and daily application tests demonstrated that hypochlorite and phenolic disinfectants can be used to produce substantial reductions in bacterial contamination in the home. Results indicate that maximum protection afforded by disinfection is relatively brief; 3-6 h after disinfection, contamination levels were only marginally less than those observed at pretreatment. Some suggestions are made for improvements in home hygiene.","pmid":"6323576","doi":"10.1017/s0022172400064214","url":"https://pubmed.ncbi.nlm.nih.gov/6323576/"},{"id":3351,"title":"A comparative kinetics study of monochloramine and hypochlorous acid in rat.","authors":"Abdel-Rahman, M S; Waldron, D M; Bull, R J","year":1983,"date":"1983 Aug","journal":"Journal of applied toxicology : JAT","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"The problem of trihalomethane formation now exists with the use of chlorine (technically, a mixture of HOCl and OCl-, depending on pH) as a disinfectant in drinking water. Monochloramine (NH2Cl) may be considered as an alternative to HOCl as a disinfectant in public water supplies. This study was conducted to compare the kinetics of NH2(36)Cl with HO36Cl in rats. The peak plasma levels of 36Cl occurred at 8 and 2 h for NH2(36)Cl and and HO36Cl, respectively. The distribution of NH2(36)Cl and HO36Cl was highest in plasma, while the lowest activity was observed in the fat. The half-life for 36Cl absorption was 2.49 and 2.16 h, while the elimination from plasma was 38.8 and 44.1 h after oral NH2(36)Cl and HO36Cl treatment, respectively. Urinary excretion accounted for most of the 36Cl eliminated in both treatments.","pmid":"6315803","doi":"10.1002/jat.2550030403","url":"https://pubmed.ncbi.nlm.nih.gov/6315803/"},{"id":3355,"title":"Disinfection studies with two strains of mouse-passaged scrapie agent. Guidelines for Creutzfeldt-Jakob and related agents.","authors":"Kimberlin, R H; Walker, C A; Millson, G C; Taylor, D M; Robertson, P A; Tomlinson, A H; Dickinson, A G","year":1983,"date":"1983 Jun","journal":"Journal of the neurological sciences","category":"Veterinary & livestock","evidence":"Human observational / experimental","relevance":"High","abstract":"A variety of disinfection procedures were tested on two strains of scrapie agent, treated either as brain macerates (autoclaving) or as 10% homogenates (chemical treatments). It is suggested that a given treatment should produce a titre loss, of both strains of scrapie, of at least 10(4) units before it be regarded as useful for the disinfection of the agents of scrapie and Creutzfeldt-Jakob disease (CJD). By this criterion, treatment at room temperature with about 4% Hycolin (0.6% chlorinated phenols), 0.2% permanganate, 5% Tego (dodecyl-di(aminoethyl)-glycine) or 5% sodium dodecyl sulphate (SDS) are unsuitable. However, data indicate that SDS might be used to reduce the heat stability of scrapie agent. Hypochlorite (Sterilex) was the only satisfactory chemical reagent tested. At least 10(4)-10(5) units of infectivity were lost by treatment with hypochlorite containing 1,000 ppm available chlorine after a 4-16 h exposure, or containing 10,000 ppm available chlorine after a half-hour exposure. The latter result points to the use of concentrated hypochlorite (about 2% available chlorine; approximately 20% Sterilex) to decontaminate surfaces. We suggest that the cleaning action of SDS, or other strong detergents, might also help to decontaminate surfaces, but studies on this are needed. Autoclaving at 126 degrees C for 1-2 h reduced titres by 10(3)-10(7) units, depending on the strain of agent. However, total disinfection of brain containing high titres of infectivity was approached only at 136 degrees C when titre losses of about 10(6) units were obtained by autoclaving for 4-32 min. Further studies are needed before we can make simple, general recommendations for the disinfection of CJD agents in hospital practice.","pmid":"6308174","doi":"10.1016/0022-510x(83)90021-7","url":"https://pubmed.ncbi.nlm.nih.gov/6308174/"},{"id":3358,"title":"Proposed mechanism for sensitization by hypochlorite treatment of Clostridium botulinum spores.","authors":"Foegeding, P M; Busta, F F","year":1983,"date":"1983 Apr","journal":"Applied and environmental microbiology","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Hypochlorite-treated Clostridium botulinum 12885A spores, but not buffer-treated spores, could be germinated with lysozyme, indicating that their coats are made permeable to lysozyme by hypochlorite treatment so that the cortex is accessible. Hypochlorite-treated spores and spores extracted with 8 M urea-2-mercaptoethanol (pH 3.0) were sensitive to certain components of recovery media, but spores sensitized to lysozyme by other treatments were not. These data indicate that hypochlorite does more than increase coat permeability to lysozyme. Scanning electron microscopy revealed a more open-appearing surface of hypochlorite-treated spores, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that a greater amount of protein was removed from hypochlorite-treated and other lysozyme-sensitized spores than from buffer-treated spores. The data suggest that spore coat proteins may be removed by hypochlorite treatment, and this may be responsible for the sensitivity of spores and for their observed ability to germinate in lysozyme.","pmid":"6305269","doi":"10.1128/aem.45.4.1374-1379.1983","url":"https://pubmed.ncbi.nlm.nih.gov/6305269/"},{"id":3360,"title":"Hypochlorite injury of Clostridium botulinum spores alters germination responses.","authors":"Foegeding, P M; Busta, F F","year":1983,"date":"1983 Apr","journal":"Applied and environmental microbiology","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"Clostridium botulinum spores were sublethally damaged by exposure to 12 or 28 micrograms of available chlorine per ml for 2 min at 25 degrees C and pH 7.0. The damaging dose was 2.7 x 10(-6) to 3.1 x 10(-6) micrograms of available chlorine per spore. Damage was manifested by a consistent 1.6 to 2.4 log difference between the most probable number enumeration of spores (modified peptone colloid medium) and the colony count (modified peptone yeast extract glucose agar); this did not occur with control spores. Damaged spores could be enumerated by the colony count procedure. Germination responses were measured in several defined and nondefined media. Hypochlorite treatment altered the rate and extent of germination in some of the media. Calcium lactate (9 mM) permitted L-alanine (4.5 mM) germination of hypochlorite-treated spores in a medium containing 12 or 55 mM sodium bicarbonate, 0.8 mM sodium thiosulfate, and 100 mM Tris-hydrochloride (pH 7.0) buffer. Tryptose inhibited L-alanine germination of the spores. Treatments with hypochlorite and with hydrogen peroxide (7%, 25 degrees C, 2 min) caused similar enumeration and germination responses, indicating that the effect was due to a general oxidation phenomenon.","pmid":"6305267","doi":"10.1128/aem.45.4.1360-1368.1983","url":"https://pubmed.ncbi.nlm.nih.gov/6305267/"},{"id":3363,"title":"Death, injury and revival of chemically treated Bacillus subtilis spores.","authors":"Gorman, S P; Hutchinson, E P; Scott, E M; McDermott, L M","year":1983,"date":"1983 Feb","journal":"The Journal of applied bacteriology","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"The resistance of spores of Bacillus subtilis NCTC 10073 to glutaraldehyde, sodium hypochlorite and povidone-iodine was compared. Revival of treated spores was examined by use of defined germination media and conditions, protein denaturing agents, ultrasonics and heat. Revival, obtained after treatment with each of the three chemical agents, originated under different sets of conditions and was of two recognizably distinct types. The results, including the evidence of electron microscopy, are discussed in terms of chemical-spore reactivity and the implications on their use and suitability as chemical sterilizers.","pmid":"6303998","doi":"10.1111/j.1365-2672.1983.tb01305.x","url":"https://pubmed.ncbi.nlm.nih.gov/6303998/"},{"id":3364,"title":"Role of pre-milking teat skin disinfection in preventing Staphylococcus aureus mastitis.","authors":"Sheldrake, R F; Hoare, R J","year":1983,"date":"1983 Feb","journal":"The Journal of dairy research","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"","pmid":"6302143","doi":"10.1017/s002202990003257x","url":"https://pubmed.ncbi.nlm.nih.gov/6302143/"},{"id":3366,"title":"Effect of chlorine treatment on infectivity of hepatitis A virus.","authors":"Peterson, D A; Hurley, T R; Hoff, J C; Wolfe, L G","year":1983,"date":"1983 Jan","journal":"Applied and environmental microbiology","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"This study examined the effect of chlorine treatment on the infectivity of hepatitis A virus (HAV). Prodromal chimpanzee feces, shown to induce hepatitis in marmosets (Saguinus sp.), was clarified, and the virus was precipitated with 7% polyethylene glycol 6000, harvested, and resuspended. The suspension was layered onto 5 to 30% linear sucrose gradients and centrifuged; the fractions containing HAV were dialyzed, and a 1:500,000 dilution of this preparation induced hepatitis and seroconversion in 2 of 4 marmosets. A 1:50 dilution of this preparation served as inoculum. Untreated inoculum induced overt hepatitis and seroconversion in 100% (5 of 5) of marmosets inoculated intramuscularly. Inoculum treated for various periods (15, 30, or 60 min) with 0.5, 1.0, or 1.5 mg of free residual chlorine per liter induced hepatitis in 14% (2 of 14), 8% (1 of 12), and 10% (1 of 10) of marmosets, respectively, and induced seroconversion in 29, 33, and 10% of the animals. Inoculum treated with 2.0 or 2.5 mg of free residual chlorine per liter was not infectious in marmosets as determined by absence of hepatitis and seroconversion in the 13 animals tested. Thus, treatment levels of 0.5 to 1.5 mg of free residual chlorine per liter inactivated most but not all HAV in the preparation, whereas concentrations of 2.0 and 2.5 mg of free residual chlorine per liter destroyed the infectivity completely. These results suggest that HAV is somewhat more resistant to chlorine than are other enteroviruses.","pmid":"6297391","doi":"10.1128/aem.45.1.223-227.1983","url":"https://pubmed.ncbi.nlm.nih.gov/6297391/"},{"id":3368,"title":"Chlorination of taurine by human neutrophils. Evidence for hypochlorous acid generation.","authors":"Weiss, S J; Klein, R; Slivka, A; Wei, M","year":1982,"date":"1982 Sep","journal":"The Journal of clinical investigation","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The model hydrogen peroxide-myeloperoxidase-chloride system is capable of generating the powerful oxidant hypochlorous acid, which can be quantitated by trapping the generated species with the beta-amino acid, taurine. The resultant stable product, taurine chloramine, can be quantitated by its ability to oxidize the sulfhydryl compound, 5-thio-2-nitro-benzoic acid to the disulfide, 5,5'-dithiobis(2-nitroben-zoic acid) or to oxidize iodide to iodine. Using this system, purified myeloperoxidase in the presence of chloride and taurine converted stoichiometric quantities of hydrogen peroxide to taurine chloramine. Chloramine generation was absolutely dependent on hydrogen peroxide, myeloperoxidase, and chloride and could be inhibited by catalase, myeloperoxidase inhibitors, or chloride-free conditions. In the presence of taurine, intact human neutrophils stimulated with either phorbol myristate acetate or opsonized zymosan particles generated a stable species capable of oxidizing 5-thio-2-nitrobenzoic acid or iodide. Resting cells did not form this species. The oxidant formed by the stimulated neutrophils was identified as taurine chloramine by both ultraviolet spectrophotometry and electrophoresis. Taurine chloramine formation by the neutrophil was dependent on the taurine concentration, time, and cell number. Neutrophil-dependent chloramine generation was inhibited by catalase, the myeloperoxidase inhibitors, azide, cyanide, or aminotriazole and by chloride-free conditions, but not by superoxide dismutase or hydroxyl radical scavengers. Thus, it appears that stimulated human neutrophils can utilize the hydrogen peroxide-myeloperoxidase-chloride system to generate taurine chloramine. Based on the demonstrated ability of the myeloperoxidase system to generate free hypochlorous acid we conclude that neutrophils chlorinate taurine by producing this powerful oxidant. The biologic reactivity and cytotoxic potential of hypochlorous acid and its chloramine derivatives suggest that these oxidants play an important role in the inflammatory response and host defense.","pmid":"6286728","doi":"10.1172/jci110652","url":"https://pubmed.ncbi.nlm.nih.gov/6286728/"},{"id":3375,"title":"The killing of newborn larvae of Trichinella spiralis by eosinophil peroxidase in vitro.","authors":"Buys, J; Wever, R; van Stigt, R; Ruitenberg, E J","year":1981,"date":"1981 Oct","journal":"European journal of immunology","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"Helminth infections in mammals are characterized by a high level of eosinophils in parasitized tissues and blood, and it has recently been suggested that these cells have a direct parasiticidal effect. Newborn larvae of Trichinella spiralis can be killed within 20 min by incubation at room temperature in a cell-free system, including purified human eosinophil peroxidase (EPO), H2O2 and chloride at pH 5.5. Killing was measured by microscopic observation of the larvae. The larvicidal effect was dependent on each component of the EPO/H2O2/Cl- system and could be prevented by using SO4(2-) instead of Cl-. Killing was totally inhibited by sodium azide and catalase, and substantially by bovine serum albumin, a protein that is an effective scavenger for HOCl. Since larvae could also be killed directly by HOCl under these conditions and EPO is able to oxidize Cl- to hypochlorous acid, it is very likely that the larvicidal effect of the EPO system is due to formation of hypochlorous acid. It is proposed that in vivo, the combination of EPO, which is exocytosed onto the surface of the parasite, and H2O2, which is generated by stimulated eosinophils, is responsible for the larvicidal effect.","pmid":"6273182","doi":"10.1002/eji.1830111018","url":"https://pubmed.ncbi.nlm.nih.gov/6273182/"},{"id":3376,"title":"Biological reactivity of hypochlorous acid: implications for microbicidal mechanisms of leukocyte myeloperoxidase.","authors":"Albrich, J M; McCarthy, C A; Hurst, J K","year":1981,"date":"1981 Jan","journal":"Proceedings of the National Academy of Sciences of the United States of America","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"Oxidative degradation of biological substrates by hypochlorous acid has been examined under reaction conditions similar to those found in active phagosomes. Iron sulfur proteins are bleached extremely rapidly, followed in decreasing order by beta-carotene, nucleotides, porphyrins, and heme proteins. Enzymes containing essential cysteine molecules are inactivated with an effectiveness that roughly parallels the nucleophilic reactivities of their sulfhydryl groups. Other compounds, including glucosamines, quinones, riboflavin, and, except for N-chlorination, phospholipids, are unreactive. Rapid irreversible oxidation of cytochromes, adenine nucleotides, and carotene pigments occurs when bacterial cells are exposed to exogenous hypochlorous acid; with Escherichia coli, titrimetric oxidation of cytochrome was found to coincide with loss of aerobic respiration. The occurrence of these cellular reactions implicates hypochlorous acid as a primary microbicide in myeloperoxidase-containing leukocytes; the reactivity patterns observed are consistent with the view that bactericidal action results primarily from loss of energy-linked respiration due to destruction of cellular electron transport chains and the adenine nucleotide pool.","pmid":"6264434","doi":"10.1073/pnas.78.1.210","url":"https://pubmed.ncbi.nlm.nih.gov/6264434/"},{"id":3377,"title":"Mechanism of the bactericidal action of myeloperoxidase: increased permeability of the Escherichia coli cell envelope.","authors":"Sips, H J; Hamers, M N","year":1981,"date":"1981 Jan","journal":"Infection and immunity","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"The killing of Escherichia coli by isolated human myeloperoxidase plus hydrogen peroxide plus chloride ions was shown to proceed via an increased permeability of the bacterial cell wall. A correlation between the extent of the increased permeability and the number of surviving colony-forming units was found (P less than 0.0005). The same phenomenon was observed with isolated human neutrophils. The permeability increase was shown to be limited, because low-molecular-weight substrate became freely permeant, but the bacteria retained their permeability barrier for protein. Furthermore, disruption of the permeability barrier was followed by destruction of cytoplasmic protein. The active antibacterial agent was probably hypochlorous acid, the direct product of the system, rather than singlet oxygen, the nonenzymic product of hypochlorous acid and hydrogen peroxide. This is concluded from the fact that the myeloperoxidase system could be mimicked by hypochlorous acid, whereas conditions that favor formation of singlet oxygen did not enhance this effect. The relevance of the system for killing of bacteria at neutral pH is discussed.","pmid":"6260658","doi":"10.1128/iai.31.1.11-16.1981","url":"https://pubmed.ncbi.nlm.nih.gov/6260658/"},{"id":3383,"title":"A potential role for hypochlorous acid in granulocyte-mediated tumor cell cytotoxicity.","authors":"Slivka, A; LoBuglio, A F; Weiss, S J","year":1980,"date":"1980 Feb","journal":"Blood","category":"Veterinary & livestock","evidence":"In vitro / laboratory","relevance":"High","abstract":"","pmid":"6243502","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/6243502/"},{"id":3384,"title":"[Antibacterial activity of a solution of H202, hypochlorite, and chloramine].","authors":"Kotula, R; Hudác, A","year":1980,"date":"1980 Jan","journal":"Ceskoslovenska stomatologie","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"","pmid":"6244901","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/6244901/"},{"id":3385,"title":"Materials and methods for cleaning dentures.","authors":"Budtz-Jørgensen, E","year":1979,"date":"1979 Dec","journal":"The Journal of prosthetic dentistry","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"Proper hygienic care of removable dentures is an important means of maintaining a healthy oral mucosa in denture wearers. Denture cleanliness is often poor due to improper mechanical cleansing and the relative inefficiency of most commercial products for chemical cleansing of dentures. Dentists and patients should realize that microbial plaque on dentures may be harmful to both the oral mucosa and the patient's general health. It is the responsibility of the patient to maintain oral hygiene through a daily home care routine. It is the obligation of the dentist to motivate and instruct the patient and provide the means and methods for plaque control. Future research should be directed to developing solution cleansers which can maintain plaque-free dentures with a daily soaking period of 15 to 30 minutes and not affect the color and surface luster of the denture acrylic resin.","pmid":"229217","doi":"10.1016/0022-3913(79)90190-2","url":"https://pubmed.ncbi.nlm.nih.gov/229217/"},{"id":3394,"title":"Myeloperoxidase, hydrogen peroxide, chloride antimicrobial system: nitrogen-chlorine derivatives of bacterial components in bactericidal action against Escherichia coli.","authors":"Thomas, E L","year":1979,"date":"1979 Feb","journal":"Infection and immunity","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"In the presence of Escherichia coli, myeloperoxidase-catalyzed oxidation of chloride ion resulted in formation of long-lived chloramine and/or chloramide derivatives of bacterial components. The same amount of these nitrogen-chlorine (N-Cl) derivatives was obtained with either hypochlorous acid (HOCl) or the myeloperoxidase system, indicating that myeloperoxidase catalyzed the oxidation of chloride to HOCl. Identical killing was obtained with HOCl or the myeloperoxidase system. About 30 to 50% of the oxidizing equivalents of HOCl were detected as N-Cl derivatives of peptides or peptide fragments that were released from the bacteria. The apparent molecular weight distribution of the peptides decreased with increasing amounts of HOCl, suggesting that peptides were fragmented by oxidative cleavage of chloramide derivatives of peptide bonds. The remaining 50 to 70% of the oxidizing equivalents of HOCl were rapidly consumed in peptide bond cleavage or the oxidation of other bacterial components. There was a close correspondence between the oxidation of bacterial sulfhydryls and bactericidal action. The N-Cl derivatives were lost and the oxidation of bacterial sulfhydryls increased over a period of several h at 37 degrees C. These changes were accompanied by increased killing. The increase in sulfhydryl oxidation and killing could be prevented by washing the bacteria to remove the N-Cl derivatives. Therefore, the N-Cl derivatives could oxidize bacterial components long after the myeloperoxidase-catalyzed oxidation of chloride was complete.","pmid":"217834","doi":"10.1128/iai.23.2.522-531.1979","url":"https://pubmed.ncbi.nlm.nih.gov/217834/"},{"id":3397,"title":"Chemically shifted singlet oxygen spectrum.","authors":"Andersen, B R; Lint, T F; Brendzel, A M","year":1978,"date":"1978 Sep 6","journal":"Biochimica et biophysica acta","category":"Veterinary & livestock","evidence":"Journal article / other","relevance":"High","abstract":"The estimated light emission spectrum was determined for a singlet oxygen (1O2)-producing system, NaOCl + H2O2, alone and in the presence of tryptophan and bovine serum albumin. Tryptophan and bovine serum albumin caused a decrease in the red emission of 1O2 and an increase in the amount of shorter wavelength light. This effect was due to chemiluminescence rather than fluorescence. Arachidonic acid caused a similar spectral shift, while guanosine demonstrated a late chemiluminescent reaction of predominantly short wavelength light in the presence of 1O2.","pmid":"210842","doi":"10.1016/0304-4165(78)90382-3","url":"https://pubmed.ncbi.nlm.nih.gov/210842/"},{"id":3406,"title":"The action of disinfectants on lamb rotavirus.","authors":"Snodgrass, D R; Herring, J A","year":1977,"date":"1977 Jul 23","journal":"The Veterinary record","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"","pmid":"197685","doi":"10.1136/vr.101.4.81-a","url":"https://pubmed.ncbi.nlm.nih.gov/197685/"},{"id":3408,"title":"[Prevention of bovine mastitis (review of foreign literature)].","authors":"Balkovoĭ, I I","year":1977,"date":"1977 Apr","journal":"Veterinariia","category":"Veterinary & livestock","evidence":"Review","relevance":"High","abstract":"","pmid":"201078","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/201078/"},{"id":3410,"title":"[Detoxification of staphylococcal-enterotoxin B in water (author's transl)].","authors":"Meyer, G; Hinterberger, J; Korte, R","year":1977,"date":"1977","journal":"Zentralblatt fur Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene. Erste Abteilung Originale. Reihe B: Hygiene, praventive Medizin","category":"Water, sanitation & biosecurity","evidence":"Animal study","relevance":"High","abstract":"Staphylococcal enterotoxin B contaminated water has been detoxified with calcium hypochlorite used in the water treatment procedure which is available now in order to get drinking water from surface water in emergency cases. Changes in toxin-activity were measured serologically by agar-gel-immuno-precipitation as well as biologically by the \"monkey-feeding test\" with young macaca mulatta. With an initial concentration of 50 ppm chlorine in tap water resp. 200 ppm in native surface water concentrations of toxin up to 40 fold average emetic dose of rhesus monkey could be inactivated safely. It was pointed out an obvious conformity between precipitation test and monkey-feeding test. The clinical efficiency of SEB on rhesus monkeys has been investigated and discussed subsequently.","pmid":"196459","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/196459/"},{"id":3413,"title":"Methods in coccidiosis research: separation of oocysts from faeces.","authors":"Ryley, J F; Meade, R; Hazelhurst, J; Robinson, T E","year":1976,"date":"1976 Dec","journal":"Parasitology","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Factors which may be important in the large-scale extraction of coccidial oocysts from faeces ha.ve been investigated with Eimeria tenella. Age of bird, inoculum, feeding status at the time of inoculation, period of collection, feeding status during collection, collection medium, homogenization and sieving, flotation, washing, sporulation and further purification have all been considered. The aim has been to establish a method to produce the maximum number of oocysts of a required degree of purity and viability, with the expenditure of the minimum amount of physical effort, time, animals and chemicals. In our method, groups of chickens 3-4 weeks of age are inoculated with 5000 oocysts of E. tenella and food is supplied ad lib. Over the period 5-8 days after inoculation, faeces are collected in trays containing 2% (w/v) potassium dichromate solution, while food intake is restricted. The faecal material is homogenized, passed once through 40 and 100 mesh sieves, centrifuged and the oocysts recovered from the sediment by 3 flotations in saturated salt solution. Following washing, oocysts are sporulated by forced aeration at 30 degrees C and may be further purified by hypochlorite treatment, or passage in 5% Tween 80 solution through a glass bead column followed by sucrose density gradient centrifugation. Routine passages along these lines over a 5 year period have given a recovery of 46% of the oocysts excreted by over 7000 birds.","pmid":"13340","doi":"10.1017/s0031182000046990","url":"https://pubmed.ncbi.nlm.nih.gov/13340/"},{"id":3419,"title":"[Clinical use of sodium hypochlorite for local treatment and prevention of urinary tract infections and therapy of contracted bladders (author's transl)].","authors":"Eisen, M; Jurcovic, K; Pfeiffer, E; Skoluda, D; Busse, K","year":1976,"date":"1976 Jan","journal":"Der Urologe. Ausg. A","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"A stable commercial electrolytic sodium hypochlorite solution was tested in 63 urologic patients. The complete germicidal action against all sorts of bacteria was shown in suspension-tests. Irrigation studies of the infected bladder were performed. It was found that continued bladder irrigations were necessary to stop bacterial ascension from the infected urethra. Bladder capacity was increased in 6 of 8 patients with nonmalignant contracted bladder or interstitial cystitis. Desinfection with sodium hypochlorite in urologic practice is cheap, easy to perform and diminishes the risk of hospitalism. Clinical studies confirmed the absence of general or local toxicity.","pmid":"176760","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/176760/"},{"id":3422,"title":"Comparison of hypochlorite teat dips containing different levels of sodium carbonate.","authors":"Natzke, R P; Postle, D S; Bray, D R","year":1975,"date":"1975 Nov","journal":"Veterinary medicine, small animal clinician : VM, SAC","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"","pmid":"171820","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/171820/"},{"id":3424,"title":"[Change in the activity of the enzymatic systems of Bacillus anthracoides spores during germination and under the action of Ca hypochlorite].","authors":"Bekhtereva, M N; Kraĭnova, O A","year":1975,"date":"1975 Sep-Oct","journal":"Mikrobiologiia","category":"Human clinical & healthcare","evidence":"Journal article / other","relevance":"Medium","abstract":"The activity of the enzymes of the citric acid cycle, glycolysis, and hexose monophosphate pathway was studied during germination of the spores of Bacillus anthracoides and upon their treatment with calcium hypochlorite. No activity of isocitrate dehydrogenase and glucose-6-phosphate dehydrogenase was found in the extracts of the vegetative cells, contrary to the spores and initiated spores. The activity of other enzymes changes but slightly in the course of germination of the spores. Treatment of the spores with calcium hypochlorite inhibited their initiation and germination and the activity of several enzymes, especially malate dehydrogenase, isocitrate dehydrogenase, and fumarase.","pmid":"173977","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/173977/"},{"id":3425,"title":"[Etiology and prevention of recurring aphthous stomatitis].","authors":"Sallay, K; Kulcsár, G; Dán, P; Nász, I; Geck, P","year":1975,"date":"1975 Sep","journal":"Deutsche zahnarztliche Zeitschrift","category":"Human clinical & healthcare","evidence":"In vitro / laboratory","relevance":"Medium","abstract":"New results concerning the etiology of recurrent aphthae are reported. According to own experiments of the authors, adenoviruses persisting in the epithelial cells of the oral mucosa may sensitize the aphthous patient. Adenovirus antigen was demonstrable in the oral mucosa cells in more than 50% of the patients and in the lymphocytes in approx. 1% of the patients. Lymphoblast transformation in the circulating lymphocytes could be demonstrated in vitro with heat-inactivated type 1 adenovirus, in 75% of the patients. This virus type has been isolated from 2 patients. Köbner's isomorphous phenomenon could be demonstrated in aphthous patients. The use of a disinfectant for mouth rinsing, the removal of foci as well as vitamin treatment are recommended for preventing recurrent aphthae.","pmid":"173517","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/173517/"},{"id":3429,"title":"The effects of various treatments on the microbial flora of whole poultry carcasses with particular reference to Staphylococcus aureus contamination.","authors":"Patterson, J T","year":1975,"date":"1975 May","journal":"British poultry science","category":"Veterinary & livestock","evidence":"Animal study","relevance":"High","abstract":"Experiments are described in which the effects of dipping defrosted eviscerated poultry carcasses, for various periods, in acetic, lactic, succinic and citric acids, hypochlorite solution containing 200 ppm free Cl2 and in water at temperatures from 70 degrees C to 100 degrees C on the microbial flora were determined. 2. Hot (70 degrees C) water dipping for 2 min appeared to be the treatment most likely to succeed in reducing Staph. aureus, giving reductions of staphylococci of from 63 to greater than 99%, without completely eliminating other organisms. 3. A storage experiment showed this method to be relatively safe, provided the carcasses were refrigerated to less than 3 degrees C as soon as possible after treatment and held at this temperature until adequately cooked.","pmid":"166733","doi":"10.1080/00071667508416191","url":"https://pubmed.ncbi.nlm.nih.gov/166733/"},{"id":3430,"title":"Water disinfection in the wilderness--a simple, effective method of iodination.","authors":"Kahn, F H; Visscher, B R","year":1975,"date":"1975 May","journal":"The Western journal of medicine","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"165639","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/165639/"},{"id":3431,"title":"[Cyclic AMP in barley seed and seedlings and bacterial and fungal contamination].","authors":"Bonnafous, J C; Olivé, J L; Borgna, J L; Mousseron-Canet, M","year":1975,"date":"1975","journal":"Biochimie","category":"Food & agriculture","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"171002","doi":"10.1016/s0300-9084(75)80148-9","url":"https://pubmed.ncbi.nlm.nih.gov/171002/"},{"id":3435,"title":"EVALUATION OF AN ANTITUMOR CELL WOUND IRRIGANT--MILTON, A STABLE HYPOCHLORITE.","authors":"VINCENT, P C; REEVE, T S; NICHOLLS, A","year":1964,"date":"1964 Aug","journal":"Cancer","category":"Human clinical & healthcare","evidence":"Animal study","relevance":"Medium","abstract":"","pmid":"14202601","doi":"10.1002/1097-0142(196408)17:8<997::aid-cncr2820170806>3.0.co;2-8","url":"https://pubmed.ncbi.nlm.nih.gov/14202601/"},{"id":3443,"title":"Flour bleachers and improvers.","authors":"","year":1961,"date":"1961 Sep 2","journal":"British medical journal","category":"Food & agriculture","evidence":"Human observational / experimental","relevance":"High","abstract":"","pmid":"14447832","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/14447832/"},{"id":3459,"title":"The action of hypochlorite and other disinfectants on micrococci with and without milk.","authors":"LASMANIS, J; SPENCER, G R","year":1953,"date":"1953 Oct","journal":"American journal of veterinary research","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"","pmid":"13092383","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/13092383/"},{"id":3467,"title":"Chemical and biologic reactions involved in the chlorination of water.","authors":"ECKBERG, O E","year":1950,"date":"1950 Jul-Aug","journal":"Medical technicians bulletin","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"","pmid":"15438351","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/15438351/"},{"id":3475,"title":"Evaluating the bactericidal efficiencies of free iodine and available chlorine by the semi-micro method.","authors":"GERSHENFELD, L; PALISI, J A","year":1949,"date":"1949 Sep","journal":"American journal of pharmacy and the sciences supporting public health","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"15394293","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/15394293/"},{"id":3476,"title":"Sporicidal properties of chlorine dioxide.","authors":"RIDENOUR, G M; INGOLS, R S; ARMBRUSTER, E H","year":1949,"date":"1949 Aug","journal":"Water & sewage works","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"18134396","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/18134396/"},{"id":3478,"title":"Chlorination at Chicago's South District Filtration Plant.","authors":"GERSTEIN, H H; BAYLIS, J R","year":1949,"date":"1949 May","journal":"Water & sewage works","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"18151807","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/18151807/"},{"id":3479,"title":"[On two cases of fungoid mycosis treated with chloramine].","authors":"LEONE, R","year":1949,"date":"1949 Mar","journal":"Il Dermosifilografo","category":"Human clinical & healthcare","evidence":"Human observational / experimental","relevance":"Medium","abstract":"","pmid":"18130516","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/18130516/"},{"id":3482,"title":"[The chlorination index].","authors":"BARON, A","year":1949,"date":"1949 Feb 28","journal":"La semaine des hopitaux : organe fonde par l'Association d'enseignement medical des hopitaux de Paris","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"18114216","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/18114216/"},{"id":3483,"title":"[Oxidation-reduction potentials and bactericidal effects of chlorine in chlorine compounds].","authors":"TRACHTMAN, N N","year":1949,"date":"1949 Feb","journal":"Higiene y salubridad","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"18129304","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/18129304/"},{"id":3485,"title":"Application of a new residual chlorine method to effluent chlorination.","authors":"STRANDSKOV, F B; MARKS, H C; HORCHLER, D H","year":1949,"date":"1949 Jan","journal":"Sewage works journal","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"18123771","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/18123771/"},{"id":3489,"title":"[A year of daily bacteriological analyzes of Leman's water and drinking water supplied to the population of Geneva].","authors":"NOVEL, E","year":1949,"date":"1949","journal":"Schweizerische Zeitschrift fur Pathologie und Bakteriologie. Revue suisse de pathologie et de bacteriologie","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"","pmid":"15391015","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/15391015/"},{"id":3494,"title":"The inhibition of sulfhydryl enzymes as the basis of the bactericidal action of chlorine.","authors":"KNOX, W E; STUMPF, P K","year":1948,"date":"1948 Apr","journal":"Journal of bacteriology","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"18909070","doi":"10.1128/JB.55.4.451-458.1948","url":"https://pubmed.ncbi.nlm.nih.gov/18909070/"},{"id":3495,"title":"[The efficiency of chlorination in large scale provisioning under the responsibility of the American Army].","authors":"FERREIRA, A B G","year":1948,"date":"1948 Apr","journal":"Boletim. Sao Paulo, Brazil (State) Reparticao de Aguas e Esgotos","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"18123317","doi":"","url":"https://pubmed.ncbi.nlm.nih.gov/18123317/"},{"id":3509,"title":"Hypochlorite sterilization of metal surfaces infected with bacteria suspended in milk.","authors":"WOLF, J; COUSINS, C M","year":1946,"date":"1946 Nov 23","journal":"Nature","category":"Food & agriculture","evidence":"Animal study","relevance":"High","abstract":"","pmid":"20276870","doi":"10.1038/158755a0","url":"https://pubmed.ncbi.nlm.nih.gov/20276870/"},{"id":3510,"title":"Bactericidal power of electrolytic hypochlorite.","authors":"MILTON, R F; HOSKINS, J L","year":1946,"date":"1946 Nov 9","journal":"Nature","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"20274357","doi":"10.1038/158673a0","url":"https://pubmed.ncbi.nlm.nih.gov/20274357/"},{"id":3511,"title":"Cultivation of Endamoeba histolytica in artificial media from cysts in drinking water subjected to chlorination.","authors":"BECKER, E R; BURKS, C; KALEITA, E","year":1946,"date":"1946 Nov","journal":"The American journal of tropical medicine and hygiene","category":"Water, sanitation & biosecurity","evidence":"Human observational / experimental","relevance":"High","abstract":"","pmid":"20279492","doi":"10.4269/ajtmh.1946.s1-26.783","url":"https://pubmed.ncbi.nlm.nih.gov/20279492/"},{"id":3515,"title":"Acid catalysis in the formation of chloroamides from hypochlorous acid; N-chlorination by hypochlorite ions and by acyl hypochlorites.","authors":"MAUGER, R P; SOPER, F G","year":1946,"date":"1946 Feb","journal":"Journal of the Chemical Society","category":"Water, sanitation & biosecurity","evidence":"Journal article / other","relevance":"High","abstract":"","pmid":"21022265","doi":"10.1039/jr9460000071","url":"https://pubmed.ncbi.nlm.nih.gov/21022265/"}]