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Li G, Tian C, Karanfil T, Liu C. Comparative formation of chlorinated and brominated disinfection byproducts from chlorination and bromination of amino acids. CHEMOSPHERE 2024; 349:140985. [PMID: 38104740 DOI: 10.1016/j.chemosphere.2023.140985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/14/2023] [Accepted: 12/14/2023] [Indexed: 12/19/2023]
Abstract
Amino acids are the main components of dissolved organic nitrogen in algal- and wastewater-impacted waters, which can react with chlorine to form toxic halogenated disinfection by-products (DBPs) in the disinfection process. In the presence of bromide, the reaction between amino acids and secondarily formed hypobromous acid can lead to the formation of brominated DBPs that are more toxic than chlorinated analogues. This study compares the formation of regulated and unregulated DBPs during chlorination and bromination of representative amino acids (AAs) (e.g., aspartic acid, asparagine, tryptophan, tyrosine, and histidine). In general, concentrations of brominated DBPs (trihalomethanes, haloacetonitriles, and haloacetamides, 24.9-5835.0 nM) during bromination were higher than their chlorinated analogues (9.3-3235.3 nM) during chlorination. This indicates the greater efficacy of bromine as a halogenating agent. However, the formation of chlorinated haloacetic acids during chlorination was higher than the corresponding brominated DBPs from bromination. It is likely that an oxidation pathway is required for the formation of haloacetic acids and chlorine is a stronger oxidant than bromine. Moreover, chlorine forms higher levels of haloacetaldehydes (74.4-1077.8 nM) from amino acids than bromine (1.0-480.2 nM) owing to the instability of brominated species. The DBP formation yields depend on the types of functional groups in the side chain of AAs. Eight intermediates resulting from chlorination/bromination of tyrosine were identified by triple quadrupole mass spectrometer, including N-chlorinated/brominated tyrosine, 3-chloro/bromo-tyrosine, and 3,5-dichloro/dibromo-tyrosine. These findings provided new insights into the DBP formation during the chlorination of algal- and wastewater-impacted waters with elevated bromide.
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Affiliation(s)
- Gengxian Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chenhao Tian
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Tanju Karanfil
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC, 29625, USA
| | - Chao Liu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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An Efficient and Economical N-Glycome Sample Preparation Using Acetone Precipitation. Metabolites 2022; 12:metabo12121285. [PMID: 36557323 PMCID: PMC9786591 DOI: 10.3390/metabo12121285] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/09/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Due to the critical role of the glycome in organisms and its close connections with various diseases, much time and effort have been dedicated to glycomics-related studies in the past decade. To achieve accurate and reliable identification and quantification of glycans extracted from biological samples, several analysis methods have been well-developed. One commonly used methodology for the sample preparation of N-glycomics usually involves enzymatic cleavage by PNGase F, followed by sample purification using C18 cartridges to remove proteins. PNGase F and C18 cartridges are very efficient both for cleaving N-glycans and for protein removal. However, this method is most suitable for a limited quantity of samples. In this study, we developed a sample preparation method focusing on N-glycome extraction and purification from large-scale biological samples using acetone precipitation. The N-glycan yield was first tested on standard glycoprotein samples, bovine fetuin and complex biological samples, and human serum. Compared to C18 cartridges, most of the sialylated N-glycans from human serum were detected with higher abundance after acetone precipitation. However, C18 showed a slightly higher efficiency for protein removal. Using the unfiltered human serum as the baseline, around 97.7% of the proteins were removed by acetone precipitation, while more than 99.9% of the proteins were removed by C18 cartridges. Lastly, the acetone precipitation was applied to N-glycome extraction from egg yolks to demonstrate large-scale glycomics sample preparation.
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Ren Z, Qiu Y, Huan M, Liu YD, Zhong R. Identification of chlorinated products from tyrosine and tyrosyl dipeptides during chlorination: a computational study. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:2345-2356. [PMID: 36281824 DOI: 10.1039/d2em00321j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Chlorinated amino acids and peptides, as the model modified protein structures relevant to pathogen inactivation and an emerging class of disinfection byproducts (DBPs) with potential health risks to humans, have attracted much attention. However, due to a large variety of peptides (over 600) identified in source water and most of them featuring multiple reaction sites, it is a huge challenge to identify all the chlorinated amino acids and peptides. As a good complement to the experiment, quantum chemical computation can be used to uncover the chlorination sites and chlorinated products. In this study, frequently detected tyrosine (Tyr) and tyrosine-amide (Tyr-Am) as well as N-acetyl-tyrosine (NacTyr) were chosen as the model amino acid and model dipeptides, respectively. The results indicate that the kinetic reactivity order of reactive sites with estimated apparent rate constants (kobs-est, in M-1 s-1) is amino N (107-8) ≫ mono-chlorinated amino N (101-3) >/≈ phenol ortho-C (100-3) ≫ meta-C (10-3), and phenol ortho-C5 (102-3) > ortho-C3 (100-2) for dipeptides, while in thermodynamics, phenol C sites are more favorable than amino N sites. Moreover, due to the smaller differences of kobs-est values between the mono-chlorinated amino N and the phenol ortho-C sites in tyrosyl dipeptides compared to free Tyr, more kinds of C-chloro-tyrosyl dipeptides are likely to be generated. Additionally, a structure-kinetic reactivity relationship study reveals good correlations between lg kobs-est and NPA charges and BDEs of protons released from amino/hydroxyl groups in tyrosyl compounds rather than FED2 (HOMO). The results are helpful to further understand the reactivity of various reaction sites in peptides and identify chlorinated products from tyrosyl peptides during chlorination.
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Affiliation(s)
- Zizhang Ren
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
| | - Yue Qiu
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
| | - Mengxue Huan
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
| | - Yong Dong Liu
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
| | - Rugang Zhong
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
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Hypochlorous Acid Chemistry in Mammalian Cells—Influence on Infection and Role in Various Pathologies. Int J Mol Sci 2022; 23:ijms231810735. [PMID: 36142645 PMCID: PMC9504810 DOI: 10.3390/ijms231810735] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/09/2022] [Accepted: 09/11/2022] [Indexed: 11/19/2022] Open
Abstract
This review discusses the formation of hypochlorous acid HOCl and the role of reactive chlorinated species (RCS), which are catalysed by the enzyme myeloperoxidase MPO, mainly located in leukocytes and which in turn contribute to cellular oxidative stress. The reactions of RCS with various organic molecules such as amines, amino acids, proteins, lipids, carbohydrates, nucleic acids, and DNA are described, and an attempt is made to explain the chemical mechanisms of the formation of the various chlorinated derivatives and the data available so far on the effects of MPO, RCS and halogenative stress. Their presence in numerous pathologies such as atherosclerosis, arthritis, neurological and renal diseases, diabetes, and obesity is reviewed and were found to be a feature of debilitating diseases.
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Dyląg M, Spychała K, Zielinski J, Łagowski D, Gnat S. Update on Stachybotrys chartarum-Black Mold Perceived as Toxigenic and Potentially Pathogenic to Humans. BIOLOGY 2022; 11:biology11030352. [PMID: 35336726 PMCID: PMC8945704 DOI: 10.3390/biology11030352] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/16/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022]
Abstract
In nature, there are many species of fungi known to produce various mycotoxins, allergens and volatile organic compounds (VOCs), as well as the commonly known etiological agents of various types of mycoses. So far, none of them have provoked so much emotion among homeowners, builders, conservators, mycologists and clinicians as Stachybotrys chartarum. This species compared to fungi of the genera Fusarium and Aspergillus is not as frequently described to be a micromycete that is toxigenic and hazardous to human and animal health, but interest in it has been growing consistently for three decades. Depending on the authors of any given review article, attention is focused either on the clinical aspects alongside the role of this fungus in deterioration of biomaterials, or aspects related to its biology, ecology and taxonomic position. On the one hand, it is well established that inhalation of conidia, containing the highest concentrations of toxic metabolites, may cause serious damage to the mammalian lung, particularly with repeated exposure. On the other hand, we can find articles in which authors demonstrate that S. chartarum conidia can germinate and form hyphae in lungs but are not able to establish an effective infection. Finally, we can find case reports that suggest that S. chartarum infection is linked with acute pulmonary hemorrhage, based on fungal structures recovered from patient lung tissue. New scientific reports have verified the current state of knowledge and note that clinical significance of this fungus is exceedingly controversial. For these reasons, understanding S. chartarum requires reviewing the well-known toxigenic features and harmful factors associated with this fungus, by gathering the newest ones into a coherent whole. The research problem related to this fungus seems to be not overly publicized, and there is still a demand to truthfully define the real threats of S. chartarum and phylogenetically related species. The most important problem, which should be fully elucidated as soon as possible, remains the clarification of the pathogenicity of S. chartarum and related species. Maybe it is urgent time to ask a critical question, namely what exactly do we know 28 years after the outbreak of pulmonary hemorrhage in infants in Cleveland, Ohio, USA most likely caused by S. chartarum?
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Affiliation(s)
- Mariusz Dyląg
- Department of Mycology and Genetics, Faculty of Biological Sciences, University of Wroclaw, 51-148 Wroclaw, Poland
- Correspondence:
| | - Klaudyna Spychała
- Student Scientific Circle (SKN Mykobiota), Faculty of Biological Sciences, University of Wroclaw, 51-148 Wroclaw, Poland;
| | - Jessica Zielinski
- Department of Oral Health Sciences, Medical University of South Carolina, Charleston, SC 29425, USA;
| | - Dominik Łagowski
- Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, 20-950 Lublin, Poland; (D.Ł.); (S.G.)
| | - Sebastian Gnat
- Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, 20-950 Lublin, Poland; (D.Ł.); (S.G.)
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Zhang D, Bond T, Li M, Dong S, Pan Y, Du E, Xiao R, Chu W. Ozonation Treatment Increases Chlorophenylacetonitrile Formation in Downstream Chlorination or Chloramination. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:3747-3755. [PMID: 33595294 DOI: 10.1021/acs.est.0c07853] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Chlorophenylacetonitriles (CPANs) are an emerging group of aromatic nitrogenous disinfection byproducts (DBPs). However, their dominant precursors and formation pathways remain unclear, which hinders the further development of effective control strategies. For the first time, CPAN precursors were screened by conducting formation potential (FP) tests on real water samples from six drinking water treatment plants (DWTPs). The average overall removal of CPAN precursors across all six DWTPs was only 10%. Moreover, ozonation increased CPAN precursors by 140% on average. Fluorescence spectroscopy showed a dramatic reduction in aromatic proteins, tyrosine-like proteins, and tryptophan-like proteins following ozonation. Low-apparent-molecular-weight (AMW) (<1 kDa) substances were correlated with the CPAN FP in these samples. We therefore hypothesized that protein fragments with low AMW, such as amino acids, are important CPAN precursors during downstream chlor(am)ination. Two aromatic free amino acids, tyrosine and tryptophan, were selected to investigate the formation of CPANs during chlor(am)ination. Both amino acids were found to act as CPAN precursors for the first time. CPAN formation pathways from these model precursors were proposed based on the frontier molecular orbital theory and intermediate products identified using high-resolution mass spectrometry. This study provides a powerful theoretical foundation for controlling CPAN formation in drinking water.
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Affiliation(s)
- Di Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, International Joint Research Center for Sustainable Urban Water System, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Tom Bond
- Department of Civil and Environmental Engineering, University of Surrey, Guildford, Surrey GU2 7XH, U.K
| | - Mingli Li
- State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, International Joint Research Center for Sustainable Urban Water System, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Shengkun Dong
- Key Laboratory of Water Cycle and Water Security in Southern China of Guangdong Higher Education Institute, School of Civil Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Yang Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Erdeng Du
- School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, Jiangsu, China
| | - Rong Xiao
- State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, International Joint Research Center for Sustainable Urban Water System, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, International Joint Research Center for Sustainable Urban Water System, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
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7
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Ekundayo TC, Igwaran A, Oluwafemi YD, Okoh AI. Global bibliometric meta-analytic assessment of research trends on microbial chlorine resistance in drinking water/water treatment systems. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 278:111641. [PMID: 33221673 DOI: 10.1016/j.jenvman.2020.111641] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/03/2020] [Accepted: 11/04/2020] [Indexed: 06/11/2023]
Abstract
Chlorine is the commonest and cheapest disinfectant used in drinking water and wastewater treatment at household, municipal and industrial levels. However, the uprising of microbial chlorine resistance (MCR) pose critical public health hazard concerns; because, its potentiate exposure to difficult-to-treat resistant pathogens. Therefore, this study aimed at evaluating the burden of MCR in drinking water/wastewater treatment and distribution systems (DWWTDS) via science mapping of research productivity (authors, countries, institutions), thematic conceptual framework, disciplines, research networks and associated intellectual landscape. MCR data were mined from Scopus and Web of Science based on optimized algorithms with the root key term "chlorine* resistant*'' and analysed for pre-set indicator variables. Results revealed 1127 documents from 442 journals and 1430% average growth rate (AGR) of research articles from 2017 to 2019 on MCR. Country-wise, the USA (n = 299), China (n = 119), and Japan (n = 43) ranked in the 1st, 2nd, and 3rd positions respectively, among the top participating countries in MCR research. MCR research had considerable performance in public health and sustainable concern subjects namely, Environmental Sciences & Ecology, Engineering, Microbiology, Water Resources, Biotechnology & Applied Microbiology, Food Science & Technology, Public, Environ & Occupational Health, Chemistry, Infectious Diseases, and Marine & Freshwater Biology; and with noticeable AGR in Environmental Sciences & Ecology (330%) and Infectious Diseases (130%). The study found biofilm-related thrusts (n = 90, 270% AGR) as main research hotspots on MCR. Overall, the study identified and discussed four important thematic areas of public health challenges in MCR that could promote increasing waterborne diseases due to (re)emerging pathogens, enteric viruses and dissemination in DWWTDS. In conclusion, this study provides comprehensive overview of the growing burden of MCR in DWWTDS and standout as a primer of information for researchers on MCR. It recommends direct, intentional and integrated research priorities on MCR to overcome accompanying public health and environmental threats. In addition, chlorine resistance in waterborne fungi have not received research attention. Research activities related to fungal chlorine resistance will be an invaluable future direction in DWWTDS and guide against exposure to waterborne pathogenic fungi and mycotoxins. It is unknown whether chlorine resistance can be acquired by horizontal gene transfer in microorganisms and future research should elucidate this important thrust.
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Affiliation(s)
- Temitope C Ekundayo
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice 5700, Eastern Cape, South Africa; Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, Eastern Cape, South Africa; Department of Biological Sciences, University of Medical Sciences, Ondo City PMB 536, Ondo State, Nigeria.
| | - Aboi Igwaran
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice 5700, Eastern Cape, South Africa; Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, Eastern Cape, South Africa
| | - Yinka D Oluwafemi
- Department of Biological Sciences, University of Medical Sciences, Ondo City PMB 536, Ondo State, Nigeria
| | - Anthony I Okoh
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice 5700, Eastern Cape, South Africa; Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, Eastern Cape, South Africa
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Wang Y, Zhang H, Song C, Gao C, Zhu G. Effect of aminophend/formaldehyde resin polymeric nanospheres as nanofiller on polyamide thin film nanocomposite membranes for reverse osmosis application. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2020.118496] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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9
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Soubhye J, Van Antwerpen P, Dufrasne F. A patent review of myeloperoxidase inhibitors for treating chronic inflammatory syndromes (focus on cardiovascular diseases, 2013-2019). Expert Opin Ther Pat 2020; 30:595-608. [DOI: 10.1080/13543776.2020.1780210] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Jalal Soubhye
- Department of Pharmacognosy, Bioanalysis and Drug Discovery, Faculty of Pharmacy, Universite Libre De Bruxelles (ULB), Bruxelles, Belgium
| | - Pierre Van Antwerpen
- Department of Pharmacognosy, Bioanalysis and Drug Discovery, Faculty of Pharmacy, Universite Libre De Bruxelles (ULB), Bruxelles, Belgium
| | - François Dufrasne
- Microbiology, Bioorganic and Macromolecular Chemistry, Faculty of Pharmacy, Universite Libre De Bruxelles, Bruxelles, Belgium
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10
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Szabó M, Bíró V, Simon F, Fábián I. The decomposition of N-chloro amino acids of essential branched-chain amino acids: Kinetics and mechanism. JOURNAL OF HAZARDOUS MATERIALS 2020; 382:120988. [PMID: 31484104 DOI: 10.1016/j.jhazmat.2019.120988] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 07/26/2019] [Accepted: 08/07/2019] [Indexed: 06/10/2023]
Abstract
The formation of N-chloro-amino acids is of outmost importance in water treatment technologies and also in vivo processes. These compounds are considered as secondary disinfectants and play important role in the defense mechanism against invading pathogens in biological systems. Adversary effects, such as apoptosis or necrosis are also associated with these compounds and the intermediates and final products formed during their decomposition. In the present study, the decomposition kinetics of the N-chloro derivatives of branched chain amino acids (BCAAs) - leucine, isoleucine, valine - were studied. On the basis of spectrophotometric measurements, it was confirmed that the decomposition proceeds via a spontaneous and an OH- assisted path in each case: kobs = k + kOH[OH-]. 1H, 13C NMR and MS experiments were also performed to identify the products and to monitor the progress of the reactions. It was established that the pH independent and the [OH-] dependent paths lead to the formation of the same aldehyde in each system (isovaleraldehyde, 2-methyl-butyraldehyde, and isobutyraldehyde) as a primary product. Under alkaline conditions, a portion of the aldehydes are converted into the corresponding Schiff-bases by the excess amino acid in a reversible process. A common mechanism was proposed for these reactions which postulates the formation of imines and hemiaminals as reactive intermediates.
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Affiliation(s)
- Mária Szabó
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
| | - Vivien Bíró
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
| | - Fruzsina Simon
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
| | - István Fábián
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary; MTA-DE Redox and Homogeneous Catalytic Reaction Mechanisms Research Group, University of Debrecen, Debrecen, Hungary.
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Yu Y, Reckhow DA. Formation of metastable disinfection byproducts during free and combined aspartic acid chlorination: Effect of peptide bonds and impact on toxicity. WATER RESEARCH 2020; 168:115131. [PMID: 31622913 DOI: 10.1016/j.watres.2019.115131] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 08/27/2019] [Accepted: 09/24/2019] [Indexed: 06/10/2023]
Abstract
The formation and occurrence of haloacetonitriles (HANs) in drinking water is of increasing concern because recent data have shown that they are the major contributors to DBP-associated toxicity of disinfected waters. Earlier research on HAN formation had established free amino acids as important HAN precursors due to their high reactivity with chlorine. However, free amino acids are unlikely to be the primary precursors for HANs in natural waters, mainly because the actual concentrations of these compounds are too low to sufficiently account for observed HAN formation. On the other hand, combined amino acids (i.e., peptides and proteins) are of much higher abundance even though it is unclear if they can contribute to HAN formation given that nearly all the amino nitrogen is tied up in peptide linkages. In order to clarify the reactivity of combined amino acids with chlorine to form HANs, dichloroacetonitrile (DCAN) formation kinetics was compared between free aspartic acid and two aspartyl-containing tetrapeptides (i.e., Asp-Asp-Asp-Asp and Arg-Gly-Asp-Ser). Results indicated that aspartyl residue could also lead to DCAN formation upon chlorination, whereas the rate of DCAN formation was much slower compared to that from free aspartic acid chlorination. Moreover, DCAN formation from the two model peptides was catalyzed by high pH. This is because chlorine-induced peptide backbone degradation is the key to DCAN formation from the chlorination of combined amino acids and this slow stepwise process is base-catalyzed. Perhaps most importantly, regardless of the precursors, DCAN was continuously formed but simultaneously degraded especially at alkaline pHs, leaving the corresponding N-chloro-2,2-dichloroacetamide (N-Cl-DCAM) and dichloroacetic acid (DCAA) as major end products. It was observed that over increasing chlorine exposure, there exists an important transition from initial organic precursors through metastable chlorination intermediates (e.g., DCAN and N-Cl-DCAM) and finally to stable end products (e.g., DCAA). By weighting DBP concentrations by their respective cytotoxic potencies, it is estimated that the aggregate cytotoxicity of chlorinated water would reach its maximum at relatively short chlorine contact times. In general, shorter water age and lower pH both resulted in higher levels of metastable intermediates (i.e., DCAN) and thus higher levels of aggregate calculated cytotoxicity. The resulting toxicity profile is different from the prevailing notion that supports current DBP regulations. Therefore, there is a risk that by placing regulatory limits and control strategies exclusively on regulated end products (e.g., HAAs), the overall toxicity of drinking water might be inadvertently elevated.
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Affiliation(s)
- Yun Yu
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, 4001 Discovery Drive, Boulder, CO, 80303, United States.
| | - David A Reckhow
- Department of Civil and Environmental Engineering, University of Massachusetts Amherst, 18 Marston Hall, 130 Natural Resources Road, Amherst, MA, 01003, United States.
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12
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Hypochlorous acid-mediated modification of proteins and its consequences. Essays Biochem 2019; 64:75-86. [DOI: 10.1042/ebc20190045] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/03/2019] [Accepted: 12/06/2019] [Indexed: 01/06/2023]
Abstract
AbstractMyeloperoxidase (MPO) is a mammalian heme peroxidase released by activated immune cells, which forms chemical oxidants, including hypochlorous acid (HOCl), to kill bacteria and other invading pathogens. In addition to this important role in the innate immune system, there is significant evidence from numerous chronic inflammatory pathologies for the elevated production of HOCl and associated oxidative modification of proteins and damage to host tissue. Proteins are major targets for HOCl in biological systems, owing to their abundance and the high reactivity of several amino acid side-chains with this oxidant. As such, there is significant interest in understanding the molecular mechanisms involved in HOCl-mediated protein damage and defining the consequences of these reactions. Exposure of proteins to HOCl results in a wide range of oxidative modifications and the formation of chlorinated products, which alter protein structure and enzyme activity, and impact the function of biological systems. This review describes the reactivity of HOCl with proteins, including the specific pathways involved in side-chain modification, backbone fragmentation and aggregation, and outlines examples of some of the biological consequences of these reactions, particularly in relation to the development of chronic inflammatory disease.
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13
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Jiang P, Jmaiff Blackstock LK, Wawryk NJ, Huang G, Li XF. Analytical characterization of N-halogenated peptides produced by disinfection: Formation, degradation, and occurrence in water. Trends Analyt Chem 2019. [DOI: 10.1016/j.trac.2018.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Shahid MA, Shi G, Yousuf M, Madridejos JML, Mahmood F, Rasheed L. A “turn-on” fluorescent probe for highly selective discrimination of hypochlorite (ClO −) from oxidants including dichromates (Cr 2O 72−) in aqueous media. NEW J CHEM 2019. [DOI: 10.1039/c9nj00610a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A carbazole-based probe was synthesized and found to fluoresce (λem,max = 440 nm) in the presence of hypochlorite.
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Affiliation(s)
- Mushtaq Ahmed Shahid
- Institute of Chemical Sciences
- Baha-ud-Din Zakaria University
- Multan 60800
- Pakistan
| | - Genggongwo Shi
- Department of Chemistry
- Ulsan National Institute of Science and Technology (UNIST)
- Ulsan 44919
- Republic of Korea
- School of Materials Science and Engineering
| | - Muhammad Yousuf
- Department of Chemistry
- Ulsan National Institute of Science and Technology (UNIST)
- Ulsan 44919
- Republic of Korea
| | - Jenica Marie L. Madridejos
- Department of Chemistry
- Ulsan National Institute of Science and Technology (UNIST)
- Ulsan 44919
- Republic of Korea
| | - Farzana Mahmood
- Institute of Chemical Sciences
- Baha-ud-Din Zakaria University
- Multan 60800
- Pakistan
| | - Lubna Rasheed
- Department of Chemistry
- Ulsan National Institute of Science and Technology (UNIST)
- Ulsan 44919
- Republic of Korea
- Division of Science and Technology
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15
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Mangum LC, Franklin NA, Garcia GR, Akers KS, Wenke JC. Rapid degradation and non-selectivity of Dakin's solution prevents effectiveness in contaminated musculoskeletal wound models. Injury 2018; 49:1763-1773. [PMID: 30104015 DOI: 10.1016/j.injury.2018.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/04/2018] [Accepted: 08/06/2018] [Indexed: 02/02/2023]
Abstract
BACKGROUND Dakin's solution (buffered sodium hypochlorite) has been used as a topical adjunct for the treatment of invasive fungal infections in trauma patients. Prudent use of Dakin's solution (DS) for complex musculoskeletal wound management implies balancing antimicrobial efficacy and human tissue toxicity, but little empirical evidence exists to inform clinical practice. To identify potentially efficacious DS concentrations and application methods, we conducted two animal studies to evaluate the ability of DS to reduce bacterial burden in small and large animal models of contaminated musculoskeletal wounds. METHODS An established rat (Rattus norvegicus) contaminated femoral defect model was employed to evaluate the antimicrobial efficacy of DS as a topical adjunctive treatment for Staphylococcus aureus infection. A range of clinically-relevant DS concentrations (0.00025%-0.125%) were tested, both with and without periodic replenishment during treatment. Next, an established goat (Capra hircus) musculoskeletal wound model, consisting of a Pseudomonas aeruginosa contaminated proximal tibia cortical defect, muscle crush, and thermal injury, was utilized to evaluate the antimicrobial efficacy of dilute DS (0.0025% and 0.025%) as a surgical irrigant solution. In situ reactive chlorine concentrations were monitored throughout each treatment using an automated iodometric titration approach. RESULTS In a rat wound model, DS treatment did not significantly reduce S. aureus bioburden after 14 days as compared to saline control. Two treatment groups (0.01% single application and 0.025% multiple application) exhibited significantly higher bacterial burden than control. In a goat musculoskeletal wound model, neither 0.0025% nor 0.025% DS significantly altered P. aeruginosa bioburden immediately following treatment or at 48 h post-treatment. Overall, DS applied to exposed soft tissue exhibited rapid degradation, e.g., 0.125% DS degraded 32% after 5 s progressing to 86% degradation after 15 min following single application. CONCLUSIONS We did not observe evidence of a therapeutic benefit following Dakin's solution treatment for any tested concentration or application method in two contaminated musculoskeletal wound models. Despite confirmation of robust bactericidal activity in vitro, our findings suggest DS at current clinically-used concentrations does not kill tissue surface-attached bacteria, nor does it necessarily cause host tissue toxicity that exacerbates infection in the setting of complex musculoskeletal injury.
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Affiliation(s)
- Lee C Mangum
- Extremity Trauma and Regenerative Medicine, United States Army Institute of Surgical Research, Fort Sam Houston, TX, USA.
| | - Nathan A Franklin
- Extremity Trauma and Regenerative Medicine, United States Army Institute of Surgical Research, Fort Sam Houston, TX, USA; Brooke Army Medical Center, Fort Sam Houston, TX, USA
| | - Gerardo R Garcia
- Extremity Trauma and Regenerative Medicine, United States Army Institute of Surgical Research, Fort Sam Houston, TX, USA
| | - Kevin S Akers
- Extremity Trauma and Regenerative Medicine, United States Army Institute of Surgical Research, Fort Sam Houston, TX, USA; Brooke Army Medical Center, Fort Sam Houston, TX, USA
| | - Joseph C Wenke
- Extremity Trauma and Regenerative Medicine, United States Army Institute of Surgical Research, Fort Sam Houston, TX, USA
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16
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Huang G, Jiang P, Jmaiff Blackstock LK, Tian D, Li XF. Formation and Occurrence of Iodinated Tyrosyl Dipeptides in Disinfected Drinking Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:4218-4226. [PMID: 29489354 DOI: 10.1021/acs.est.7b06276] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Iodinated disinfection byproducts (I-DBPs) are highly toxic, but few precursors of I-DBPs have been investigated. Tyrosine-containing biomolecules are ubiquitous in surface water. Here we investigated the formation of I-DBPs from the chloramination of seven tyrosyl dipeptides (tyrosylglycine, tyrosylalanine, tyrosylvaline, tyrosylhistidine, tyrosylglutamine, tyrosylglutamic acid, and tyrosylphenylalanine) in the presence of potassium iodide. High resolution mass spectrometry and tandem mass spectrometry (MS/MS) analyses of the benchtop reaction solutions found that all seven precursors formed both I- and Cl-substituted tyrosyl dipeptide products. Iodine substitutions occurred on the 3- and 3,5-positions of the tyrosyl-phenol ring while chlorine substituted on the free amino group. To reach the needed sensitivity to detect iodinated tyrosyl dipeptides in authentic waters, we developed a high performance liquid chromatography (HPLC)-MS/MS method with multiple reaction monitoring mode and solid phase extraction. HPLC-MS/MS analysis of tap and corresponding raw water samples, collected from three cities, identified four iodinated peptides, 3-I-/3,5-di-I-Tyr-Ala and 3-I-/3,5-di-I-Tyr-Gly, in the tap waters but not in the raw waters. The corresponding precursors, Tyr-Ala and Tyr-Gly, were also detected in the same tap and raw water samples. This study demonstrates that iodinated dipeptides exist as DBPs in drinking water.
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Affiliation(s)
- Guang Huang
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta Canada T6G 2G3
| | - Ping Jiang
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta Canada T6G 2G3
| | - Lindsay K Jmaiff Blackstock
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta Canada T6G 2G3
| | - Dayong Tian
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta Canada T6G 2G3
- College of Chemical and Environmental Engineering , Anyang Institute of Technology , Anyang 455000 , Henan P. R. China
| | - Xing-Fang Li
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta Canada T6G 2G3
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17
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Jiang P, Huang G, Jmaiff Blackstock LK, Zhang J, Li XF. Ascorbic Acid Assisted High Performance Liquid Chromatography Mass Spectrometry Differentiation of Isomeric C-Chloro- and N-Chloro-Tyrosyl Peptides in Water. Anal Chem 2017; 89:13642-13650. [DOI: 10.1021/acs.analchem.7b04262] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Ping Jiang
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, Alberta Canada T6G 2G3
| | - Guang Huang
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, Alberta Canada T6G 2G3
| | - Lindsay K. Jmaiff Blackstock
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, Alberta Canada T6G 2G3
| | - Jianye Zhang
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, Alberta Canada T6G 2G3
- College
of Chemistry and Molecular Engineering, Zhengzhou University, Henan, People’s Republic of China, 450052
| | - Xing-Fang Li
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, Alberta Canada T6G 2G3
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18
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de Vera GA, Gernjak W, Radjenovic J. Predicting reactivity of model DOM compounds towards chlorine with mediated electrochemical oxidation. WATER RESEARCH 2017; 114:113-121. [PMID: 28229949 DOI: 10.1016/j.watres.2017.01.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 01/19/2017] [Accepted: 01/20/2017] [Indexed: 06/06/2023]
Abstract
Chlorine demand of a water sample depends on the characteristics of dissolved organic matter (DOM). It is an important parameter for water utilities used to assess oxidant and/or disinfectant consumption of source waters during treatment and distribution. In this study, model compounds namely resorcinol, tannic acid, vanillin, cysteine, tyrosine, and tryptophan were used to represent the reactive moieties of complex DOM mixtures. The reactivity of these compounds was evaluated in terms of Cl2 demand and electron donating capacity (EDC). The EDC was determined by mediated electrochemical oxidation (MEO) which involves the use of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) as an electron shuttle. The Cl2 demand of readily oxidizable compounds (resorcinol, tannic acid, vanillin, and cysteine) was found to correlate well with EDC (R2 = 0.98). The EDC values (mol e-/mol C) of the model compounds are as follows: 1.18 (cysteine) > 0.77 (resorcinol) > 0.59 (vanillin) > 0.52 (tannic acid) > 0.36 (tryptophan) > 0.19 (tyrosine). To determine the effect of pre-oxidation on EDC, ozone was added (0.1 mol O3/mol C) into each model compound solution. Ozonation caused a general decrease in EDC (10-40%), chlorine demand (10-30%), and UV absorbance (10-40%), except for tyrosine which showed both increased UV275 and EDC. Before and after ozonation, 24 h disinfection byproduct (DBP) formation potential tests (Cl2 residual = 1.5 mg/L) were conducted to evaluate the use of EDC for DBP formation prediction. The results indicate that there was no significant correlation between the EDC of the model compounds and the formation potentials of adsorbable organic chlorine, trichloromethane, and trichloroacetic acid. This suggests that while EDC correlates with Cl2 demand, chlorine consumption may not directly translate to DBP formation because oxidation reactions may dominate over substitution reactions. Overall, this study provides useful insights on the reactions of ABTS+ and HOCl with model DOM compounds, and highlights the potential application of MEO for rapid determination of Cl2 demand of a water sample.
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Affiliation(s)
- Glen Andrew de Vera
- The University of Queensland, Advanced Water Management Centre, Queensland, 4072, Australia
| | - Wolfgang Gernjak
- The University of Queensland, Advanced Water Management Centre, Queensland, 4072, Australia; ICRA, Catalan Institute for Water Research, Scientific and Technological Park of the University of Girona, H(2)O Building, Emili Grahit 101, 17003 Girona, Spain; ICREA, Catalan Institute for Research and Advanced Studies, 08010, Barcelona, Spain
| | - Jelena Radjenovic
- The University of Queensland, Advanced Water Management Centre, Queensland, 4072, Australia; ICRA, Catalan Institute for Water Research, Scientific and Technological Park of the University of Girona, H(2)O Building, Emili Grahit 101, 17003 Girona, Spain.
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19
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Huang G, Jiang P, Li XF. Mass Spectrometry Identification of N-Chlorinated Dipeptides in Drinking Water. Anal Chem 2017; 89:4204-4209. [DOI: 10.1021/acs.analchem.7b00228] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Guang Huang
- Division of Analytical and
Environmental Toxicology, Department of Laboratory Medicine and Pathology,
Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Ping Jiang
- Division of Analytical and
Environmental Toxicology, Department of Laboratory Medicine and Pathology,
Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
| | - Xing-Fang Li
- Division of Analytical and
Environmental Toxicology, Department of Laboratory Medicine and Pathology,
Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3
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20
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Lin H, Levison BS, Buffa JA, Huang Y, Fu X, Wang Z, Gogonea V, DiDonato JA, Hazen SL. Myeloperoxidase-mediated protein lysine oxidation generates 2-aminoadipic acid and lysine nitrile in vivo. Free Radic Biol Med 2017; 104:20-31. [PMID: 28069522 PMCID: PMC5353359 DOI: 10.1016/j.freeradbiomed.2017.01.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 12/29/2016] [Accepted: 01/05/2017] [Indexed: 12/13/2022]
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/H2O2/Cl- system of leukocytes. At low molar ratio of oxidant to target protein Nε-lysine moiety, 2-AAA is formed via an initial Nε-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 Nε-lysine amine ratios, protein-bound LysCN is formed via initial generation of a lysine Nε-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.
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Affiliation(s)
- Hongqiao Lin
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, United States; Department of Chemistry, Cleveland State University, Cleveland, OH 44115, United States
| | - Bruce S Levison
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, United States
| | - Jennifer A Buffa
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, United States; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH 44195, United States
| | - Ying Huang
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, United States; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH 44195, United States
| | - Xiaoming Fu
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, United States; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH 44195, United States
| | - Zeneng Wang
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, United States; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH 44195, United States
| | - Valentin Gogonea
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, United States; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH 44195, United States; Department of Chemistry, Cleveland State University, Cleveland, OH 44115, United States
| | - Joseph A DiDonato
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, United States; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH 44195, United States
| | - Stanley L Hazen
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, United States; Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH 44195, United States; Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH 44195, United States.
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21
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Affiliation(s)
- Jun Jacob Hu
- Morningside Laboratory for Chemical Biology and Department of Chemistry; The University of Hong Kong; Pokfulam Road Hong Kong P. R. China
| | - Sen Ye
- Morningside Laboratory for Chemical Biology and Department of Chemistry; The University of Hong Kong; Pokfulam Road Hong Kong P. R. China
| | - Dan Yang
- Morningside Laboratory for Chemical Biology and Department of Chemistry; The University of Hong Kong; Pokfulam Road Hong Kong P. R. China
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22
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Novoa-Luna KA, Romero-Romero R, Natividad-Rangel R, Galar-Martínez M, SanJuan-Reyes N, García-Medina S, Martínez-Vieyra C, Neri-Cruz N, Gómez-Oliván LM. Oxidative stress induced in Hyalella azteca by an effluent from a NSAID-manufacturing plant in Mexico. ECOTOXICOLOGY (LONDON, ENGLAND) 2016; 25:1288-1304. [PMID: 27256318 DOI: 10.1007/s10646-016-1682-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/25/2016] [Indexed: 06/05/2023]
Abstract
Production in the pharmaceutical industry has increased and along with it, the amount of wastewater of various characteristics and contaminant concentrations. The main chemicals in these effluents are solvents, detergents, disinfectants-such as sodium hypochlorite (NaClO)-and pharmaceutical products, all of which are potentially ecotoxic. Therefore, this study aimed to evaluate the oxidative stress induced in the amphipod Hyalella azteca by the effluent from a nonsteroidal anti-inflammatory drug (NSAID)-manufacturing plant. The median lethal concentration (72 h-LC50) was determined and H. azteca were exposed to the lowest observed adverse effect level (0.0732 %) for 12, 24, 48 and 72 h, and biomarkers of oxidative stress were evaluated [hydroperoxide content (HPC), lipid peroxidation (LPX), protein carbonyl content (PCC), and the activity of the superoxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)]. Statistically significant increases with respect to the control group (P < 0.05) were observed in HPC, LPX and PCC in H. azteca at all exposure times. Antioxidant enzymes activity SOD, CAT and GPx activity also increased significantly (P < 0.05) with respect to the control group. In conclusion, the industrial effluent analyzed in the present study contains NSAIDs and NaClO, and induces oxidative stress in H. azteca.
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Affiliation(s)
- Karen Adriana Novoa-Luna
- Laboratorio de Toxicología Ambiental, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón intersección Paseo Tollocan s/n. Col. Residencial Colón, 50120, Toluca, State of Mexico, Mexico
| | - Rubí Romero-Romero
- Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, Unidad San Cayetano, 50200, Toluca, State of Mexico, Mexico
| | - Reyna Natividad-Rangel
- Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, Unidad San Cayetano, 50200, Toluca, State of Mexico, Mexico
| | - Marcela Galar-Martínez
- Laboratorio de Toxicología Acuática, Sección de Graduados e Investigación, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Plan de Ayala y Carpio s/n, 11340, Mexico, D.F., Mexico
| | - Nely SanJuan-Reyes
- Laboratorio de Toxicología Ambiental, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón intersección Paseo Tollocan s/n. Col. Residencial Colón, 50120, Toluca, State of Mexico, Mexico
| | - Sandra García-Medina
- Laboratorio de Toxicología Acuática, Sección de Graduados e Investigación, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Plan de Ayala y Carpio s/n, 11340, Mexico, D.F., Mexico
| | - Catalina Martínez-Vieyra
- Laboratorio de Toxicología Ambiental, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón intersección Paseo Tollocan s/n. Col. Residencial Colón, 50120, Toluca, State of Mexico, Mexico
| | - Nadia Neri-Cruz
- Laboratorio de Toxicología Ambiental, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón intersección Paseo Tollocan s/n. Col. Residencial Colón, 50120, Toluca, State of Mexico, Mexico
| | - Leobardo Manuel Gómez-Oliván
- Laboratorio de Toxicología Ambiental, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón intersección Paseo Tollocan s/n. Col. Residencial Colón, 50120, Toluca, State of Mexico, Mexico.
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23
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Song X, Ju H, Lasanajak Y, Kudelka MR, Smith DF, Cummings RD. Oxidative release of natural glycans for functional glycomics. Nat Methods 2016; 13:528-34. [PMID: 27135973 PMCID: PMC4887297 DOI: 10.1038/nmeth.3861] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 03/28/2016] [Indexed: 12/13/2022]
Abstract
Glycans have essential roles in biology and the etiology of many diseases. A major hurdle in studying glycans through functional glycomics is the lack of methods to release glycans from diverse types of biological samples. Here we describe an oxidative strategy using household bleach to release all types of free reducing N-glycans and O-glycan-acids from glycoproteins, and glycan nitriles from glycosphingolipids. Released glycans are directly useful in glycomic analyses and can be derivatized fluorescently for functional glycomics. This chemical method overcomes the limitations in glycan generation and promotes archiving and characterization of human and animal glycomes and their functions.
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Affiliation(s)
- Xuezheng Song
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Hong Ju
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Yi Lasanajak
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Matthew R Kudelka
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - David F Smith
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Richard D Cummings
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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24
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Claes L, Matthessen R, Rombouts I, Stassen I, De Baerdemaeker T, Depla D, Delcour JA, Lagrain B, De Vos DE. Bio-based nitriles from the heterogeneously catalyzed oxidative decarboxylation of amino acids. CHEMSUSCHEM 2015; 8:345-352. [PMID: 25470619 DOI: 10.1002/cssc.201402801] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/21/2014] [Indexed: 06/04/2023]
Abstract
The oxidative decarboxylation of amino acids to nitriles was achieved in aqueous solution by in situ halide oxidation using catalytic amounts of tungstate exchanged on a [Ni,Al] layered double hydroxide (LDH), NH4 Br, and H2 O2 as the terminal oxidant. Both halide oxidation and oxidative decarboxylation were facilitated by proximity effects between the reactants and the LDH catalyst. A wide range of amino acids was converted with high yields, often >90 %. The nitrile selectivity was excellent, and the system is compatible with amide, alcohol, and in particular carboxylic acid, amine, and guanidine functional groups after appropriate neutralization. This heterogeneous catalytic system was applied successfully to convert a protein-rich byproduct from the starch industry into useful bio-based N-containing chemicals.
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Affiliation(s)
- Laurens Claes
- Centre for Surface Chemistry and Catalysis, Department of Microbial and Molecular Systems, KU Leuven, Kasteelpark Arenberg 23, 3001 Heverlee (Belgium)
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25
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Sakuma M, Matsushita T, Matsui Y, Aki T, Isaka M, Shirasaki N. Mechanisms of trichloramine removal with activated carbon: stoichiometric analysis with isotopically labeled trichloramine and theoretical analysis with a diffusion-reaction model. WATER RESEARCH 2015; 68:839-848. [PMID: 25466640 DOI: 10.1016/j.watres.2014.10.051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/20/2014] [Accepted: 10/21/2014] [Indexed: 06/04/2023]
Abstract
This study investigated the mechanism by which activated carbon removes trichloramine, a byproduct of water treatment that has a strongly offensive chlorinous odor. A stoichiometrical mass balance for ¹⁵N before and after activated carbon treatment of laboratory-prepared ¹⁵N-labeled trichloramine solutions clearly revealed that the mechanism of trichloramine removal with activated carbon was not adsorption but rather reductive decomposition to nitrogen gas. There was a weak positive correlation between the surface decomposition rate constant of trichloramine and the concentration of basic functional groups on the surface of the carbon particles, the suggestion being that the trichloramine may have been reduced by sulfhydryl groups (-SH) on the activated carbon surface. Efficient decomposition of trichloramine was achieved with super powdered activated carbon (SPAC), which was prepared by pulverization of commercially available PAC into very fine particles less than 1 μm in diameter. SPAC could decompose trichloramine selectively, even when trichloramine and free chlorine were present simultaneously in water, the indication being that the strong disinfection capability of residual free chlorine could be retained even after trichloramine was effectively decomposed. The residual ratio of trichloramine after carbon contact increased somewhat at low water temperatures of 1-5 °C. At these low temperatures, biological treatment, the traditional method for control of a major trichloramine precursor (ammonium nitrogen), is inefficient. Even at these low temperatures, SPAC could reduce the trichloramine concentration to an acceptable level. A theoretical analysis with a diffusion-reaction model developed in the present study revealed that the increase in the trichloramine residual with decreasing water temperature was attributable to the temperature dependence of the rate of the reductive reaction rather than to the temperature dependence of the diffusive mass transfer rate.
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Affiliation(s)
- Miki Sakuma
- Graduate School of Engineering, Hokkaido University, N13W8, Sapporo 060-8628, Japan
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26
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Maresh JJ, Crowe SO, Ralko AA, Aparece MD, Murphy CM, Krzeszowiec M, Mullowney MW. Facile one-pot synthesis of tetrahydroisoquinolines from amino acids via hypochlorite-mediated decarboxylation and Pictet–Spengler condensation. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.07.043] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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27
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Yoo DG, Winn M, Pang L, Moskowitz SM, Malech HL, Leto TL, Rada B. Release of cystic fibrosis airway inflammatory markers from Pseudomonas aeruginosa-stimulated human neutrophils involves NADPH oxidase-dependent extracellular DNA trap formation. THE JOURNAL OF IMMUNOLOGY 2014; 192:4728-38. [PMID: 24740504 DOI: 10.4049/jimmunol.1301589] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cystic fibrosis (CF) airways are characterized by bacterial infections, excess mucus production, and robust neutrophil recruitment. The main CF airway pathogen is Pseudomonas aeruginosa. Neutrophils are not capable of clearing the infection. Neutrophil primary granule components, myeloperoxidase (MPO) and human neutrophil elastase (HNE), are inflammatory markers in CF airways, and their increased levels are associated with poor lung function. Identifying the mechanism of MPO and HNE release from neutrophils is of high clinical relevance for CF. In this article, we show that human neutrophils release large amounts of neutrophil extracellular traps (NETs) in the presence of P. aeruginosa. Bacteria are entangled in NETs and colocalize with extracellular DNA. MPO, HNE, and citrullinated histone H4 are all associated with DNA in Pseudomonas-triggered NETs. Both laboratory standard strains and CF isolates of P. aeruginosa induce DNA, MPO, and HNE release from human neutrophils. The increase in peroxidase activity of neutrophil supernatants after Pseudomonas exposure indicates that enzymatically active MPO is released. P. aeruginosa induces a robust respiratory burst in neutrophils that is required for extracellular DNA release. Inhibition of the cytoskeleton prevents Pseudomonas-initiated superoxide production and DNA release. NADPH oxidase inhibition suppresses Pseudomonas-induced release of active MPO and HNE. Blocking MEK/ERK signaling results in only minimal inhibition of DNA release induced by Pseudomonas. Our data describe in vitro details of DNA, MPO, and HNE release from neutrophils activated by P. aeruginosa. We propose that Pseudomonas-induced NET formation is an important mechanism contributing to inflammatory conditions characteristic of CF airways.
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Affiliation(s)
- Dae-goon Yoo
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
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Šakić D, Šonjić P, Tandarić T, Vrček V. Chlorination of N-methylacetamide and amide-containing pharmaceuticals. Quantum-chemical study of the reaction mechanism. J Phys Chem A 2014; 118:2367-76. [PMID: 24601593 DOI: 10.1021/jp5012846] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chlorination of amides is of utmost importance in biochemistry and environmental chemistry. Despite the huge body of data, the mechanism of reaction between amides and hypochlorous acid in aqueous environment remains unclear. In this work, the three different reaction pathways for chlorination of N-methylacetamide by HOCl have been considered: the one-step N-chlorination of the amide, the chlorination via O-chlorinated intermediate, and the N-chlorination of the iminol intermediate. The high-level quantum chemical G3B3 composite procedure, double-hybrid B2-PLYPD, B2K-PLYP methods, and global hybrid M06-2X and BMK methods have been employed. The calculated energy barriers have been compared to the experimental value of ΔG(#)298 ≈ 87 kJ/mol, which corresponds to reaction rate constant k(r) ≈ 0.0036 M(-1) s(-1). Only the mechanism in which the iminol form of N-methylacetamide reacts with HOCl is consistent (ΔG(#)298 = 87.3 kJ/mol at G3B3 level) with experimental results. The analogous reaction mechanism has been calculated as the most favorable pathway in the chlorination of small-sized amides and amide-containing pharmaceuticals: carbamazepine, acetaminophen, and phenytoin. We conclude that the formation of the iminol intermediate followed by its reaction with HOCl is the general mechanism of N-chlorination for a vast array of amides.
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Affiliation(s)
- Davor Šakić
- Faculty of Pharmacy and Biochemistry, University of Zagreb , A. Kovačića 1, 10000 Zagreb, Croatia
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Tolleson WH, Jackson LS, Triplett OA, Aluri B, Cappozzo J, Banaszewski K, Chang CW, Nguyen KT. Chemical inactivation of protein toxins on food contact surfaces. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:6627-6640. [PMID: 22690810 DOI: 10.1021/jf301601v] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We compared the kinetics and efficacies of sodium hypochlorite, peracetic acid, phosphoric acid-based detergent, chlorinated alkaline detergent, quaternary ammonium-based sanitizer, and peracetic acid-based sanitizer for inactivating the potential bioterrorism agents ricin and abrin in simple buffers, food slurries (infant formula, peanut butter, and pancake mix), and in dried food residues on stainless steel. The intrinsic fluorescence and cytotoxicity of purified ricin and abrin in buffers decreased rapidly in a pH- and temperature-dependent manner when treated with sodium hypochlorite but more slowly when treated with peracetic acid. Cytotoxicity assays showed rapid and complete inactivation of ricin and crude abrin in food slurries and dried food residues treated 0-5 min with sodium hypochlorite. Toxin epitopes recognized by ELISA decayed more gradually under these conditions. Higher concentrations of peracetic acid were required to achieve comparable results. Chlorinated alkaline detergent was the most effective industrial agent tested for inactivating ricin in dried food residues.
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Affiliation(s)
- William H Tolleson
- Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas 72079, United States.
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Pattison DI, Davies MJ, Hawkins CL. Reactions and reactivity of myeloperoxidase-derived oxidants: Differential biological effects of hypochlorous and hypothiocyanous acids. Free Radic Res 2012; 46:975-95. [DOI: 10.3109/10715762.2012.667566] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Shah AD, Mitch WA. Halonitroalkanes, halonitriles, haloamides, and N-nitrosamines: a critical review of nitrogenous disinfection byproduct formation pathways. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:119-31. [PMID: 22112205 DOI: 10.1021/es203312s] [Citation(s) in RCA: 426] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Interest in the formation of nitrogenous disinfection byproducts (N-DBPs) has increased because toxicological research has indicated that they are often more genotoxic, cytotoxic, or carcinogenic than many of the carbonaceous disinfection byproducts (C-DBPs) that have been a focus for previous research. Moreover, population growth has forced utilities to exploit source waters impaired by wastewater effluents or algal blooms. Both waters feature higher levels of organic nitrogen, that might serve as N-DBP precursors. Utilities are exploring new disinfectant combinations to reduce the formation of regulated trihalomethanes and haloacetic acids. As some of these new combinations may promote N-DBP formation, characterization of N-DBP formation pathways is needed. Formation pathways for halonitroalkanes, halonitriles, haloamides, and N-nitrosamines associated with chlorine, ozone, chlorine dioxide, UV, and chloramine disinfection are critically reviewed. Several important themes emerge from the review. First, the formation pathways of the N-DBP families are partially linked because most of the pathways involve similar amine precursors. Second, it is unlikely that a disinfection scheme that is free of byproduct formation will be discovered. Disinfectant combinations should be optimized to reduce the overall exposure to toxic byproducts. Third, the understanding of formation pathways should be employed to devise methods of applying disinfectants that minimize byproduct formation while accomplishing pathogen reduction goals. Fourth, the well-characterized nature of the monomers constituting the biopolymers that likely dominate the organic nitrogen precursor pool should be exploited to predict the formation of byproducts likely to form at high yields.
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Affiliation(s)
- Amisha D Shah
- Department of Chemical and Environmental Engineering, Yale University, Mason Lab 313b, 9 Hillhouse Avenue, New Haven, Connecticut 06520, United States
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Argüello-García R, Medina-Campos ON, Pérez-Hernández N, Pedraza-Chaverrí J, Ortega-Pierres G. Hypochlorous acid scavenging activities of thioallyl compounds from garlic. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:11226-11233. [PMID: 20942486 DOI: 10.1021/jf102423w] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The hypochlorous acid (HOCl) scavenging capacities of 10 garlic compounds containing modifications in the thioallyl group (-S-CH2CH ═ CH2) were determined by a catalase protection assay, and the corresponding structure-activity relationships using molecular descriptors were calculated. This scavenging activity was enhanced by increasing the number of S atoms or by the alanyl group (-CH2CH-NH2-COOH) and decreased in the absence of the C ═ C bond or in the presence of a sulfoxide group in the thioallyl group. Interestingly, S-allylcysteine and its corresponding sulfoxide (alliin) showed the highest and lowest HOCl-scavenging capacities, respectively. Quantitative modeling by multiple regression analysis and partial least-squares projections showed that the topological descriptor polar surface area and two electronic properties, namely, highest occupied molecular orbital and total energy, contributed mainly to variations in the HOCl scavenging activity of thioallyl compounds. These observations provide new insights on the antioxidant mechanism of garlic derivatives in processes involving HOCl production.
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Affiliation(s)
- Raúl Argüello-García
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados-IPN, 07360 Mexico City, Mexico
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Oxidation of Free L-histidine by tert-Butylhydroperoxide. Pharm Res 2010; 27:447-56. [DOI: 10.1007/s11095-009-0032-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Accepted: 12/07/2009] [Indexed: 10/19/2022]
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Hayes-Larson EL, Mitch WA. Influence of the method of reagent addition on dichloroacetonitrile formation during chloramination. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:700-706. [PMID: 20000677 DOI: 10.1021/es9025112] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Formation of dichloroacetonitrile (DCAN) in natural waters was evaluated for different disinfection scenarios, including application of free chlorine, preformed monochloramine or dichloramine, or formation of chloramines in situ by addition of free chlorine and ammonia in either order. Formation of DCAN was highest during free chlorination. Regardless of the order of ammonia or chlorine addition, DCAN formation was consistently higher over 1-2 day contact times when chloramines were formed in situ than when preformed chloramines were applied. During in situ chloramine formation, organic amine precursors effectively competed with ammonia to react with free chlorine, forming organic dichloramine intermediates to nitrile formation. Combined with previous research indicating that application of preformed monochloramine reduced nitrosamine formation, the results indicate that application of preformed monochloramine could provide an inexpensive alternative for chloraminating utilities to significantly reduce the exposure to DCAN and nitrosamines for consumers located within 1-2 days of water travel time from the treatment plant. This technique would be applicable in situations where chloramination is used alone (e.g., chlorination of non-nitrified secondary wastewater effluents during municipal wastewater recycling), or combined with primary disinfectants other than free chlorine (e.g., ozonation, chlorine dioxide, or ultraviolet light).
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Affiliation(s)
- Eleanor L Hayes-Larson
- Department of Chemical Engineering, Environmental Engineering Program, Yale University, New Haven, Connecticut 06520, USA
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35
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Katre YR, Joshi GK, Singh AK. Kinetics and mechanism of oxidation of L-Alanine by N-bromophthalimide in the presence of sodium dodecyl sulfate. KINETICS AND CATALYSIS 2009. [DOI: 10.1134/s0023158409030057] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Terada T, Akimoto Y, Hyo S, Suzuki D, Tanaka K, Takenaka H. Allergic potency of Japanese cedar pollen Cry j 1 is reduced by a low concentration of hypochlorous acid generated by electolysis. Allergol Int 2009; 58:255-60. [PMID: 19307775 DOI: 10.2332/allergolint.08-oa-0043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Accepted: 11/08/2008] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Although Japanese cedar (Cryptomeria japonica) pollinosis has developed into a health problem, few methods eradicate indoor allergens completely. In a recent study, however, the effectiveness of inactivation with sodium hypochlorite (NaOCl) treatment was revealed. Therefore, the present study aimed to elucidate the ability of chlorine bleach (NaOCl) to reduce the immunogenicity of the major allergenic protein of Japanese cedar (Cry j 1). METHODS Sodium dodecyl sulfate polyacrylamide gel electrophoresis, Western blotting, enzyme-linked immunosorbant assay, and skin testing were carried out in 7 individuals. RESULTS The allergenic protein was undetectable using sodium dodecyl sulfate polyacrylamide gel electrophoresis and silver staining at a sodium hypochlorite/allergenic protein molar ratio of 457. Western blotting with human sera showed the same dose-dependent efficacy. The immunogenicity of the purified protein and cedar pollen was also demonstrated on enzyme-linked immunosorbant assay to be reduced by sodium hypochlorite treatment in a dose- and time-dependent manner. Moreover, sodium hypochlorite-treatment inhibited the skin test response to the protein in all 7 individuals. CONCLUSIONS Hypochlorous acid generated by electrolysis is an effective method for significantly reducing the immunogenicity of Cry j 1.
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Affiliation(s)
- Tetsuya Terada
- Department of Otorhinolaryngology, Osaka Medical College, Osaka, Japan. Takatsuki, Osaka, Japan.
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Sauro S, Mannocci F, Tay FR, Pashley DH, Cook R, Carpenter GH, Watson TF. Deproteinization Effects of NaOCl on Acid-etched Dentin in Clinically-relevant vs Prolonged Periods of Application. A Confocal and Environmental Scanning Electron Microscopy Study. Oper Dent 2009; 34:166-173. [DOI: 10.2341/08-56] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Clinical Relevance
Complete removal of the collagen matrix prior to dentin bonding procedures has been proposed as a strategy to prevent later degradation, which may jeopardize the longevity of resin-dentin bonds. This study demonstrates that a complete removal of the exposed collagen matrix from the etched dentin surface can be achieved by applying a 12 w/v% NaOCl solution, but at this concentration, it requires a far longer reaction time than is clinically acceptable.
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Bessac BF, Jordt SE. Breathtaking TRP channels: TRPA1 and TRPV1 in airway chemosensation and reflex control. Physiology (Bethesda) 2009; 23:360-70. [PMID: 19074743 DOI: 10.1152/physiol.00026.2008] [Citation(s) in RCA: 289] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
New studies have revealed an essential role for TRPA1, a sensory neuronal TRP ion channel, in airway chemosensation and inflammation. TRPA1 is activated by chlorine, reactive oxygen species, and noxious constituents of smoke and smog, initiating irritation and airway reflex responses. Together with TRPV1, the capsaicin receptor, TRPA1 may contribute to chemical hypersensitivity, chronic cough, and airway inflammation in asthma, COPD, and reactive airway dysfunction syndrome.
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Affiliation(s)
- Bret F Bessac
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, USA
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Yang YK, Cho HJ, Lee J, Shin I, Tae J. A Rhodamine−Hydroxamic Acid-Based Fluorescent Probe for Hypochlorous Acid and Its Applications to Biological Imagings. Org Lett 2009; 11:859-61. [DOI: 10.1021/ol802822t] [Citation(s) in RCA: 248] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Young-Keun Yang
- Department of Chemistry, Yonsei University, Seoul 120-749, Korea
| | | | - Jihyun Lee
- Department of Chemistry, Yonsei University, Seoul 120-749, Korea
| | - Injae Shin
- Department of Chemistry, Yonsei University, Seoul 120-749, Korea
| | - Jinsung Tae
- Department of Chemistry, Yonsei University, Seoul 120-749, Korea
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Coker MSA, Hu WP, Senthilmohan ST, Kettle AJ. Pathways for the Decay of Organic Dichloramines and Liberation of Antimicrobial Chloramine Gases. Chem Res Toxicol 2008; 21:2334-43. [DOI: 10.1021/tx800232v] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Melanie S. A. Coker
- Free Radical Research Group, Department of Pathology, University of Otago, Christchurch, P.O. Box 4345, Syft Technologies Ltd., P.O. Box 28-149, and Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Wan-Ping Hu
- Free Radical Research Group, Department of Pathology, University of Otago, Christchurch, P.O. Box 4345, Syft Technologies Ltd., P.O. Box 28-149, and Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Senti T. Senthilmohan
- Free Radical Research Group, Department of Pathology, University of Otago, Christchurch, P.O. Box 4345, Syft Technologies Ltd., P.O. Box 28-149, and Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Anthony J. Kettle
- Free Radical Research Group, Department of Pathology, University of Otago, Christchurch, P.O. Box 4345, Syft Technologies Ltd., P.O. Box 28-149, and Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
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Bessac BF, Sivula M, von Hehn CA, Escalera J, Cohn L, Jordt SE. TRPA1 is a major oxidant sensor in murine airway sensory neurons. J Clin Invest 2008; 118:1899-910. [PMID: 18398506 DOI: 10.1172/jci34192] [Citation(s) in RCA: 337] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Accepted: 02/13/2008] [Indexed: 11/17/2022] Open
Abstract
Sensory neurons in the airways are finely tuned to respond to reactive chemicals threatening airway function and integrity. Nasal trigeminal nerve endings are particularly sensitive to oxidants formed in polluted air and during oxidative stress as well as to chlorine, which is frequently released in industrial and domestic accidents. Oxidant activation of airway neurons induces respiratory depression, nasal obstruction, sneezing, cough, and pain. While normally protective, chemosensory airway reflexes can provoke severe complications in patients affected by inflammatory airway conditions like rhinitis and asthma. Here, we showed that both hypochlorite, the oxidizing mediator of chlorine, and hydrogen peroxide, a reactive oxygen species, activated Ca(2+) influx and membrane currents in an oxidant-sensitive subpopulation of chemosensory neurons. These responses were absent in neurons from mice lacking TRPA1, an ion channel of the transient receptor potential (TRP) gene family. TRPA1 channels were strongly activated by hypochlorite and hydrogen peroxide in primary sensory neurons and heterologous cells. In tests of respiratory function, Trpa1(-/-) mice displayed profound deficiencies in hypochlorite- and hydrogen peroxide-induced respiratory depression as well as decreased oxidant-induced pain behavior. Our results indicate that TRPA1 is an oxidant sensor in sensory neurons, initiating neuronal excitation and subsequent physiological responses in vitro and in vivo.
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Affiliation(s)
- Bret F Bessac
- Department of Pharmacology and Section of Pulmonary and Critical Care Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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Deborde M, von Gunten U. Reactions of chlorine with inorganic and organic compounds during water treatment-Kinetics and mechanisms: a critical review. WATER RESEARCH 2008; 42:13-51. [PMID: 17915284 DOI: 10.1016/j.watres.2007.07.025] [Citation(s) in RCA: 1033] [Impact Index Per Article: 64.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 07/13/2007] [Accepted: 07/18/2007] [Indexed: 05/17/2023]
Abstract
Numerous inorganic and organic micropollutants can undergo reactions with chlorine. However, for certain compounds, the expected chlorine reactivity is low and only small modifications in the parent compound's structure are expected under typical water treatment conditions. To better understand/predict chlorine reactions with micropollutants, the kinetic and mechanistic information on chlorine reactivity available in literature was critically reviewed. For most micropollutants, HOCl is the major reactive chlorine species during chlorination processes. In the case of inorganic compounds, a fast reaction of ammonia, halides (Br(-) and I(-)), SO(3)(2-), CN(-), NO(2)(-), As(III) and Fe(II) with HOCl is reported (10(3)-10(9)M(-1)s(-1)) whereas low chlorine reaction rates with Mn(II) were shown in homogeneous systems. Chlorine reactivity usually results from an initial electrophilic attack of HOCl on inorganic compounds. In the case of organic compounds, second-order rate constants for chlorination vary over 10 orders of magnitude (i.e. <0.1-10(9)M(-1)s(-1)). Oxidation, addition and electrophilic substitution reactions with organic compounds are possible pathways. However, from a kinetic point of view, usually only electrophilic attack is significant. Chlorine reactivity limited to particular sites (mainly amines, reduced sulfur moieties or activated aromatic systems) is commonly observed during chlorination processes and small modifications in the parent compound's structure are expected for the primary attack. Linear structure-activity relationships can be used to make predictions/estimates of the reactivity of functional groups based on structural analogy. Furthermore, comparison of chlorine to ozone reactivity towards aromatic compounds (electrophilic attack) shows a good correlation, with chlorine rate constants being about four orders of magnitude smaller than those for ozone.
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Affiliation(s)
- Marie Deborde
- Department of Water Resources and Drinking Water, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Dübendorf, Switzerland
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Ditor DS, Bao F, Chen Y, Dekaban GA, Weaver LC. A therapeutic time window for anti-CD 11d monoclonal antibody treatment yielding reduced secondary tissue damage and enhanced behavioral recovery following severe spinal cord injury. J Neurosurg Spine 2006; 5:343-52. [PMID: 17048772 DOI: 10.3171/spi.2006.5.4.343] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The purpose of this study was to investigate the therapeutic time window for antiinflammatory treatment within the first 24 hours of spinal cord injury (SCI). The authors have shown that an anti-CD11d antibody treatment attenuates leukocyte infiltration and improves neurological function when administered beginning 2 hours after SCI. A more clinically relevant time for the initiation of treatment after SCI, however, is 6 or more hours postinjury. METHODS In Study 1, the T-4 vertebrae in four groups of rats were injured by a 50-g clip-induced compression method, and the anti-CD11d antibody (1 mg/kg) was intravenously administered starting 2, 6, 12, or 24 hours postinjury. All groups received subsequent doses at 24 and 48 hours, and animals were killed at 72 hours. The anti-CD11d antibody treatment starting at 6 hours postinjury caused significant attenuation of leukocyte infiltration, reactive oxygen species-associated enzymes, and secondary tissue damage. Based on these findings, Study 2 included two groups of rats receiving the aforementioned injury and treatment beginning at 6 hours postinjury (with subsequent treatments at 24 and 48 hours) with the anti-CD11d or a control antibody (1B7); these rats were then observed for 5 weeks. Basso-Beattie-Bresnahan (BBB) scores were significantly higher in anti-CD11d-treated rats (mean BBB score 8.9 +/- 0.1) than controls (mean BBB score 7.7 +/- 0.1) 5 weeks postinjury. Increases in mean arterial pressure during colon distension were smaller in anti-CD11d-treated rats (19.5 +/- 3.7 mm Hg) than in controls (37.4 +/- 4.7 mm Hg). CONCLUSIONS These findings suggest that antiinflammatory treatments that reduce secondary tissue damage after SCI may be delayed until 6 hours postinjury and still be effective.
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Affiliation(s)
- David S Ditor
- Spinal Cord Injury Team, BioTherapeutics Research Group, Robarts Research Institute, London, Ontario, Canada.
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Batchinsky AI, Martini DK, Jordan BS, Dick EJ, Fudge J, Baird CA, Hardin DE, Cancio LC. Acute respiratory distress syndrome secondary to inhalation of chlorine gas in sheep. ACTA ACUST UNITED AC 2006; 60:944-56; discussion 956-7. [PMID: 16688054 DOI: 10.1097/01.ta.0000205862.57701.48] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Toxic industrial chemicals (TICs) are potential terrorist weapons. Several TICs, such as chlorine, act primarily on the respiratory tract, but knowledge of the pathophysiology and treatment of these injuries is inadequate. This study aims to characterize the acute respiratory distress syndrome (ARDS) caused by chlorine gas (Cl2) inhalation in a large-animal model. METHODS Anesthetized female sheep were ventilated with 300 L of a Cl2/air/oxygen mixture for 30 minutes. In phase 1 (n = 35), doses were 0 ppm (Group 1, n = 6); 120 ppm (Group 2, n = 6); 240 to 350 ppm (Group 3, n = 11); and 400 to 500 ppm (Group 4, n = 12). In phase 2 (n = 17), doses were 0 ppm (Group 5, n = 5); 60 ppm (Group 6, n = 5); and 90 ppm (Group 7, n = 7), and the multiple inert gas elimination technique (MIGET) was used to characterize the etiology of hypoxemia. Computed tomography (CT) scans were performed daily for all animals. RESULTS In Phase 1, lung function was well maintained in Group 1; Cl2 caused immediate and sustained acute lung injury (PaO2-to-FiO2 ratio, PFR<3.0) in Group 2 and ARDS (PFR<2.0) in Groups 3 and 4. All animals in Groups 1 and 2 survived 96 hours. Kaplan-Meier analysis showed dose-related differences in survival (log-rank test, p < 0.0001). Logistic regression identified 280 ppm as the lethal dose 50%. CT and histopathology demonstrated lesions of both small airways and alveoli. In Phase 2, MIGET showed diversion of blood flow from normal to true-shunt lung compartments and, transiently, to poorly ventilated compartments. CONCLUSIONS Cl2 causes severe, dose-related lung injury, with features seen in both smoke inhalation and in ARDS secondary to systemic disease. This model will be used to test new therapeutic modalities.
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Affiliation(s)
- Andriy I Batchinsky
- US Army Institute of Surgical Research, Fort Sam Houston, Texas 78234-6315, USA
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Malle E, Marsche G, Arnhold J, Davies MJ. Modification of low-density lipoprotein by myeloperoxidase-derived oxidants and reagent hypochlorous acid. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:392-415. [PMID: 16698314 DOI: 10.1016/j.bbalip.2006.03.024] [Citation(s) in RCA: 316] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Revised: 03/27/2006] [Accepted: 03/28/2006] [Indexed: 10/24/2022]
Abstract
Substantial evidence supports the notion that oxidative processes contribute to the pathogenesis of atherosclerosis and coronary heart disease. The nature of the oxidants that give rise to the elevated levels of oxidised lipids and proteins, and decreased levels of antioxidants, detected in human atherosclerotic lesions are, however, unclear, with multiple species having been invoked. Over the last few years, considerable data have been obtained in support of the hypothesis that oxidants generated by the heme enzyme myeloperoxidase play a key role in oxidation reactions in the artery wall. In this article, the evidence for a role of myeloperoxidase, and oxidants generated therefrom, in the modification of low-density lipoprotein, the major source of lipids in atherosclerotic lesions, is reviewed. Particular emphasis is placed on the reactions of the reactive species generated by this enzyme, the mechanisms and sites of damage, the role of modification of the different components of low-density lipoprotein, and the biological consequences of such oxidation on cell types present in the artery wall and in the circulation, respectively.
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Affiliation(s)
- Ernst Malle
- Medical University Graz, Center of Molecular Medicine, Institute of Molecular Biology and Biochemistry, Harrachgasse 21, A-8010 Graz, Austria.
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Panzella L, Di Donato P, Comes S, Napolitano A, Palumbo A, d’Ischia M. Remarkable Chichibabin-type cyclotrimerisation of 3-nitrotyrosine, tyrosine and phenylalanine to 3,5-diphenylpyridine derivatives induced by hypochlorous acid. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.07.106] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
The influence of dentin on the effectiveness of three antibacterial agents (triclosan, glutaraldehyde, NaOCl) on Streptococcus mutans, S. sobrinus, and Lactobacillus acidophilus was tested using the agar diffusion method with and without bovine dentin discs (200 mum and 500 mum thickness) placed between bacteria and test substances. The effect of 0.3% triclosan on all tester strains (100%) was reduced after passage through 500 mum dentin discs to 0% (L. acidophilus) and to 22% and 28% (S. mutans and S. sobrinus). Seal&Protect (Dentsply, Konstanz, Germany), a triclosan containing dental bonding agent, produced inhibition zones only against S. mutans, but no zone when applied on 200 mum dentin discs. The inhibition zones for 1% NaOCl and 5% glutaraldehyde against all tester strains were significantly increased up to 230% (glutaraldehyde) and 236% (NaOCl) when applied on dentin discs, compared to direct application (100%). Dentin may either decrease or increase the inhibitory effect of antibacterial agents.
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Affiliation(s)
- Zeynep Ergücü
- Department of Operative Dentistry and Periodontology, University of Regensburg, Regensburg, Germany
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Matsui E, Kagey-Sobotka A, Chichester K, Eggleston PA. Allergic potency of recombinant Fel d 1 is reduced by low concentrations of chlorine bleach. J Allergy Clin Immunol 2003; 111:396-401. [PMID: 12589362 DOI: 10.1067/mai.2003.11] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Sodium hypochlorite (NaOCl), the primary component of household bleach, has been shown to alter the purified mouse allergen Mus m 1, such that antibody recognition, or immunogenicity, is lost. Results of initial experiments suggest that antibody recognition is lost at lower concentrations of NaOCl than those required to fragment Mus m 1. OBJECTIVE We sought to determine whether NaOCl had similar effects on recombinant (r)Fel d 1 and whether the loss of antibody recognition correlated with the loss of biologic activity, as measured with a basophil histamine release assay. METHODS Recombinant Fel d 1 was treated with increasing amounts of NaOCl, and the product of the reaction was analyzed by using SDS-PAGE, Western blotting, and ELISA. The biologic activity of NaOCl-treated rFel d 1 was analyzed with a basophil histamine release assay. RESULTS The protein fragmented at an NaOCl/rFel d 1 molar ratio of 7000, whereas cat-specific IgG recognition was lost at a lower molar ratio of 560. Basophil histamine release assays were performed to determine the effect of NaOCl on the biologic activity of rFel d 1. An NaOCl/protein molar ratio of 70 caused a significant reduction in histamine release from basophils of subjects with cat allergy. A molar ratio of 140 further inhibited histamine release by rFel d 1, suggesting a dose-response relationship between NaOCl and loss of biologic activity. CONCLUSIONS NaOCl modifies rFel d 1, resulting in loss of immunogenicity and attenuation of biologic activity, as measured by its ability to stimulate basophil histamine release.
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Affiliation(s)
- Elizabeth Matsui
- Departments of Pediatrics and Medicine, Johns Hopkins School of Medicine, Johns Hopkins Hospital, 600 N. Wolfe Street, Baltimore, MD 21287, USA
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Habelitz S, Balooch M, Marshall SJ, Balooch G, Marshall GW. In situ atomic force microscopy of partially demineralized human dentin collagen fibrils. J Struct Biol 2002; 138:227-36. [PMID: 12217661 DOI: 10.1016/s1047-8477(02)00029-1] [Citation(s) in RCA: 224] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Dentin collagen fibrils were studied in situ by atomic force microscopy (AFM). New data on size distribution and the axial repeat distance of hydrated and dehydrated collagen type I fibrils are presented. Polished dentin disks from third molars were partially demineralized with citric acid, leaving proteins and the collagen matrix. At this stage collagen fibrils were not resolved by AFM, but after exposure to NaOCl(aq) for 100-240 s, and presumably due to the removal of noncollagenous proteins, individual collagen fibrils and the fibril network of dentin connected to the mineralized substrate were revealed. High-aspect-ratio silicon tips in tapping mode were used to image the soft fibril network. Hydrated fibrils showed three distinct groups of diameters: 100, 91, and 83 nm and a narrow distribution of the axial repeat distance at 67 nm. Dehydration resulted in a broad distribution of the fibril diameters between 75 and 105 nm and a division of the axial repeat distance into three groups at 67, 62, and 57 nm. Subfibrillar features (4 nm) were observed on hydrated and dehydrated fibrils. The gap depth between the thick and thin repeating segments of the fibrils varied from 3 to 7 nm. Phase mode revealed mineral particles on the transition from the gap to the overlap zone of the fibrils. This method appears to be a powerful tool for the analysis of fibrillar collagen structures in calcified tissues and may aid in understanding the differences in collagen affected by chemical treatments or by diseases.
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Affiliation(s)
- Stefan Habelitz
- Department of Preventive and Restorative Dental Sciences, University of California, 707 Parnassus Avenue D-2260, San Francisco, CA 94143, USA.
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A joint theoretical and kinetic investigation on the fragmentation of (N-halo)-2-amino cycloalkanecarboxylates. Chem Phys 2002. [DOI: 10.1016/s0301-0104(02)00487-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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