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PubMed1992

Disopyramide block of cardiac sodium current after removal of the fast inactivation process in guinea pig ventricular myocytes.

To determine the necessity of sodium channel fast inactivation for the block of sodium current (INa) by disopyramide, we studied the effects of disopyramide on INa in guinea pig ventricular myocytes treated with chloramine-T, which removes the fast component of INa inactivation. After exposure to chloramine-T (2 mM), INa amplitude was reduced at all voltages and INa decay was irreversibly prevented. Disopyramide (20 microM) produced both tonic block and use-dependent block of INa in chloramine-T-treated myocytes. Before treatment with chloramine-T, the time course of both the onset of and recovery from use-dependent block by disopyramide were best fit by the sum of double exponential functions, and the time constant of the slow phase of recovery increased as the membrane was hyperpolarized. After removal of the fast component of INa inactivation by chloramine-T, the fast phase of the onset block and the fast phase of recovery from block were abolished. However, the voltage dependency of the time course of recovery from block was unchanged. Thus, although the fast sodium inactivation process is not required for tonic and use-dependent block of INa by disopyramide, it contributes to the fast phase of block development and unbinding from use-dependent block.

Animals↗
PubMed1989

Yeast-suspension as soiling matter in disinfectant testing.

Using the Kelsey-Sykes capacity-test, it was found that a sterile yeast suspension used to simulate 'dirty' conditions, gave an increased effect of Chloramine T against the fungi Candida albicans, Aspergillus fumigatus, Geotrichum candidum and Penicillium sp. compared with the effect under 'clean' conditions. This effect was not found with the fungus Rhodotorula rubra nor on the various bacteria tested. The enhanced effect was found with respect to both Chloramine T and Chloramine B, but not with the sodium hypochlorite solution when tested on C. albicans. This effect was due to a diffusible factor from the yeast cells. The factor was evident in the solution after heating of the yeast-cell suspension and in unsterilized yeast-cell suspension left at room temperature for 2 h or more. The effect of Chloramine T on the fungi C. albicans and A. fumigatus was reduced as expected when the yeast suspension was replaced by 20% normal horse serum. The results indicate that using sterile yeast suspensions in this type of test, may erroneously give high fungicidal effects of Chloramine, and thus lead to an incorrect use-dilution concentration, especially if the determination is made on the basis of the effect observed only under dirty conditions.

Aspergillus fumigatus↗
PubMedDate not supplied

[Asthma caused by sodium p-toluene-n-chloro-sulfonamide: observations on a clinical case].

We describe the case of a patient exposed to chloramine-T who experienced severe asthmatic symptoms when spraying chloramine-T solutions. The patient used chloramine-T as a sterilising agent in medical facilities. Occupational asthma due to chloramine-T was diagnosed by means of specific bronchial provocation test (occupational type). We stress the risk of exposure to high levels of chloramine-T and the importance of this compound as a cause of occupational asthma.

Asthma↗
PubMed1996

Complement activation by myeloperoxidase products released from stimulated human polymorphonuclear leukocytes.

Purified human myeloperoxidase (MPO) converted human C5 to an activated form, i.e. the C5 protein adopted a configuration expressing a binding site for C6; the resulting C56 complex then reacted with C7, C8 and C9 forming a hemolytic C5-9 complex. For the activation by myeloperoxidase chloride and hydrogen peroxide were essential. This indicates that the peroxidase acted through the generation of HOCl which had been shown earlier to oxidize and activate C5. Human polymorphonuclear leukocytes (PMN) were stimulated in vitro by incubation with opsonized zymosan; thereafter the supernatants were tested for C5 activating potency. Stimulated PMN release H2O2 and MPO that produces hypochlorite and secondarily various chloramines. As a trap for the labile hypochlorite generated excess taurine was added to the PMN suspensions during the incubation. Hypochlorite is then stoichiometrically converted to the relatively stable taurine chloramine. In order to rule out interfering activities of proteolytic enzymes released from the PMN and known to attack C5, the supernatants were ultracentrifuged, and the ultrafiltrates, containing only low molecular weight compounds, were used for the further studies. They contained taurine chloramine, estimated photometrically, and they activated C5 upon incubation, assayed functionally by reactive lysis. Azide, an inhibitor of myeloperoxidase, and catalase which destroys H2O2, essential for MPO-catalyzed oxidations, prevented the generation of C5 activating potency and of chloramines. Unstimulated PMN produced neither oxidants nor C5 activating potency. When taurine was omitted from the PMN suspensions during stimulations much less oxidant was found in the supernatants and less C5 activating potency. These findings indicate that the C5 activating agent was produced by stimulated PMN through MPO-generated hypochlorite, trapped as taurine chloramine. In the absence of added taurine the hypochlorite formed by MPO oxidized endogenous amines that also activated C5. Further studies suggested that among these was some monochloramine derived from endogenous ammonia. Activation of the terminal complement reaction sequence by MPO released from stimulated PMN may represent a third pathway to complement activation contributing to and reinforcing complement and PMN functions at the site of inflammation or tissue injury.

Complement Activation↗
PubMed2001

Chlorite-hemoprotein interaction as key role for the pharmacological activity of the chlorite-based drug WF10.

WF10 is a chlorite-based drug that modulates macrophages functional states and can be safely administered to humans. WF10 potentially modulates disease-related up-regulation of immune responses both in vitro and in vivo. Thus immune response is influenced in a way that inappropriate inflammatory reactions are downregulated. The molecular mechanisms involved are not completely understood. Biochemical data suggest the reaction of chlorite with hemoproteins as the central step in the activation process of the drug. Thereby a chlorinating agent is generated, resulting in the oxidation of reduced sulfur-containing molecules and in the conversion of amino residues into more or less stable chloramines. The most prominent chloramine in vivo is taurine chloramine. Taurine chloramine is a long-lived molecule with immunomodulatory properties. For instance, taurine chloramine inhibits the generation of macrophage inflammatory mediators such as nitric oxide, prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6). This study on the biochemical mechanism of WF10 gives evidence that hemoprotein dependent chlorination of taurine is not only observed in vitro but also very likely in vivo. To characterize the oxidant, generated during heme activation, different methods were used: Chemiluminescence, EPR-spectroscopy, UV/VIS-spectroscopy, gas (GC) and size exclusion chromatography. In summary, the results indicate as the first products of hemoprotein catalyzed chlorite activation a chloroxygen-species (probably HOCl/OCl-) and a ferryl-oxygen species at the hemoprotein active site in analogy to the known peroxidase (compound I and II) intermediates. Moreover, hydrogen peroxide and chlorite seem to react in a similar way with heme centers. It is proposed that WF10 represents an "inactive" transport form of potentially active chlorine. Reactivity of the latter is restricted unless heme moieties in proteins or enzymes activate the "transport form" to perform reactions in analogy to peroxidases (i.e. myeloperoxidase-catalyzed formation of HOCl/OCl-).

Amino Acids, Cyclic↗
PubMed1985

Evidence for a role of taurine in the in vitro oxidative toxicity of neutrophils toward erythrocytes.

Production of hydrogen peroxide and secretion of myeloperoxidase by stimulated neutrophils resulted in myeloperoxidase-catalyzed oxidation of chloride to hypochlorous acid (HOCl), the reaction of HOCl with taurine to yield taurine monochloramine (TauNHCl), and accumulation of TauNHCl in the extracellular medium. When erythrocytes were present, the yield of TauNHCl was lower as the result of uptake of TauNHCl into erythrocytes. The zwitterion taurine was not taken up, but the anion TauNHCl and other anionic oxidants including taurine dichloramine (TauNCl2) and L-alanine chloramines were transported into erythrocytes by the anion-transport system. Oxidation of intracellular components such as glutathione (GSH) by taurine chloramines resulted in reduction of the chloramines and trapping of taurine within erythrocytes. At high oxidant:erythrocyte ratios, TauNHCl also oxidized hemoglobin (Hb) and depleted ATP, but caused little lysis. TauNCl2 was much more effective as a lytic agent. At low oxidant:erythrocyte ratios, the chloramines caused net loss of GSH when no glucose was provided, but Hb was not oxidized and GSH content returned to normal when glucose was added. Therefore, anionic chloramines may mediate oxidative toxicity when the neutrophil:erythrocyte ratio is high. Under more physiologic conditions, chlorination of taurine by neutrophils and the uptake and reduction of TauNHCl by erythrocytes prevents accumulation of oxidants and may protect blood cells, plasma components, and tissues against oxidative toxicity.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed2006

The determinants of prevalence of health complaints among young competitive swimmers.

OBJECTIVES: Chloramines, which are produced by the reaction of chlorine with the organic matter present in indoor pools, are potential airway irritants in swimmers. The objective of this study was to compare the prevalence of health complaints of young swimmers and young indoor soccer players and to evaluate the relationship between chloramine concentrations and the athletes' health complaints. METHODS: Health complaints were first (Part 1) documented by questionnaire in 305 competitive swimmers and 499 indoor soccer players of the Québec City region (Canada). Then, (Part 2) health complaints were documented during five training sessions in 72 competitive swimmers in comparison to 73 soccer players. The chloramines in the swimming pool air and water were measured as well as the peak expiratory flow (PEF) before and after the training session. RESULTS: In Part 1, the swimmers reported more lower (adjusted OR: 1.5; IC95%= 1.0-2.2) and upper respiratory symptoms (adjusted OR: 3.7; IC95%= 2.4-5.8). In Part 2, the swimmers experienced more frequent lower (adjusted OR: 3.5; IC95%= 2.0-6.0) and upper respiratory symptoms (adjusted OR: 3.1; IC95%= 1.8-5.4). Overall, swimmers exposed to the highest levels of chloramines in the air and water had more respiratory complaints. CONCLUSIONS: Swimmers exposed to chlorination by-products in both the water and air of indoor swimming pools experience frequent respiratory symptoms that could potentially be reduced by limiting exposure to these products.

Adolescent↗
PubMed1982

Comparison and evaluation of different methods for alpha-MSH labelling.

We have studied the behaviour of 125I-labelled alpha-MSH under different experimental conditions. Until now, the chloramine T method had been used by most investigators with variable results. We have tested three other labelling techniques based on 125I mild oxidation: (1) an enzymatic method with lactoperoxidase, (2) a sparingly soluble chloramine method (T.D.G.U.) and (3) modified chloramine T procedure, 'the iodine volatilization method'. Labelled hormone obtained after each kind of iodination was assayed for immunoreactivity. In addition, time course degradation was measured by classical RIA incubation procedures. Charcoal-dextran was used to separate bound and free antigen. We have found chloramine T-iodinated alpha-MSH to be significantly more damaged than preparations obtained by other methods and to be less stable when stored at -18 degrees C. No differences were found between the differently labelled 125I-labelled alpha-MSH fresh preparations in binding to surface receptors of human melanoma cell lines in culture.

Animals↗
PubMed1984

Immunochemical evaluation of radioiodinated protein A.

The [125I]iodoprotein A iodinated by the chloramine-T method using carrier-free 125I- to various specific activities (0.02-2.0 125I/mole protein A) displayed 85% binding activity to excess solid-phase rabbit IgG. On storage, however, the solid-phase IgG binding activity of the high specific activity [125I]iodoprotein A (approximately 2 125I/protein A) decreased rapidly while that of the low specific activity [125I]iodoprotein A (approximately 0.2 125I/protein A) remained essentially unchanged. Analysis of aged high specific activity [125I]iodoprotein A by thin-layer chromatography revealed that free 125I- was released from the [125I]iodoprotein A during storage. Removal of the released 125I- was accomplished by using anion exchange resin. High specific activity [125I]iodoprotein A was found to be more sensitive than the low specific activity [125I]iodoprotein A in quantitating aggregated IgG while the latter was as useful as the former in hybridoma screening. When protein A was labeled with the Bolton-Hunter reagent, the [125I]iodoprotein A had an IgG binding property and stability similar to the [125I]iodoprotein A labeled with the chloramine-T method. Since the chloramine-T method can yield high specific activity [125I]iodoprotein A and repurification of the aged preparation can easily be achieved by using anion exchange resin, we concluded that chloramine-T is more efficient than Bolton-Hunter reagent and that both methods yield materials with comparable immunochemical properties.

Animals↗
PubMed1992

Effect of tooth storage and cavity cleansing on cervical gap formation in Class II glass-ionomer/composite restorations.

Class II cavities with the cervical margin just below the C-E junction and with two cervical retention grooves were prepared in intact human premolars, 31 cavities in teeth stored frozen and 29 cavities in teeth stored in 1% chloramine solution. The teeth from both storage conditions were assigned to two groups; in one group, the cavities were cleaned with a water spray, in the other group, with a cleaner containing 0.2% EDTA and 1% NaF. All cavities were lined with Vitrebond and restored with P50. Cervical contraction gaps were disclosed by a fluorescent resin penetration technique. The length and width of each gap were analysed. A contraction gap was revealed in 17 of the 31 cavities in teeth stored frozen (54.8%) and in 22 of the 29 restorations in the teeth stored in chloramine (75.8%). The width of the gap was significantly greater in teeth stored in chloramine (p = 0.0004). No statistical difference in gap formation was found between cavities cleaned with water or with the detergent containing 0.2% EDTA and sodium fluoride. Since the cavity cleansing procedure was not a significant factor in gap formation, apparently removing the superficial smear layer with the cavity cleaner does not impair the bonding of Vitrebond to the dentin. However, gap formation appeared to be significantly affected by the storage conditions of the extracted teeth. It is suggested that teeth to be used in bond strength and leakage experiments should be stored frozen rather than stored in 1% chloramine solution.

Analysis of Variance↗
PubMed2004

Making chlorine greener: investigation of alternatives to sulfite for dechlorination.

Inorganic and organic chloramines pose a threat to aquatic ecosystems that are exposed to discharges of treated and disinfected wastewater. Conventionally practiced dechlorination with sulfite reduces the most refractory organic chloramines too slowly to produce wastewater effluents that meet current ecosystem protection criteria in the United States (i.e. total residual chlorine < or =0.011mg Cl(2)/L in freshwaters). Seeking faster dechlorinating agents, we have measured the rates that four test chloramines (NH(2)Cl, N-Cl-piperidine, N-Cl-leucylalanine and N-Cl-alanylalanine) react with 10 selected reducing agents at pH 7.4 and pH 8.4. The aqueous-phase reducing agents that offer speed advantages over sulfite alone include dithionite, thiosulfate, and iodide-mediated sulfite. Ascorbic acid was the most reactive of the sulfur-free agents but was found to be slow relative to sulfite. The potential biological oxygen demand might constrain the choice of aqueous reductants. Metallic iron is shown to reduce inorganic and organic chloramines effectively. The implications of these results for wastewater chlorine reduction and analysis are discussed.

Ascorbic Acid↗
PubMed2001

Chlorination of pure bacterial cultures in aqueous solution.

The fate and distribution of chlorine in aqueous solutions containing four pure bacterial cultures was studied. Solutions were subjected to chlorination at different initial free chlorine concentrations. Resulting concentrations of residual chlorine were determined by both DPD/FAS titration and membrane introduction mass spectrometry (MIMS). In all cases, false-positive breakpoint chlorination curves, probably attributable to the formation of chloroorganic-N compounds, were observed by DPD/FAS titration, while little or no inorganic residual chloramine was found by MIMS. Free chlorine was observed in similar quantities by both methods after chlorine demand by bacterial cellular materials in solution was satisfied. These results indicated the residual chloramines existed in the form of organic chloramines; these compounds are generally recognized as being poor antimicrobial agents. Further investigation confirmed that the bacterial cells were the source of organic-N compounds. The kinetics of chlorination of pure bacterial suspensions was also studied. The pattern of residual chlorine decay following chlorination of the bacterial suspensions indicated rapid initial free chlorine consumption, followed by slow free chlorine consumption, with trace quantities of inorganic chloramine being formed.

Chloramines↗
PubMed2004

Stability of cyanogen chloride in the presence of free chlorine and monochloramine.

Cyanogen chloride (CNCl) is a disinfection byproduct found in chlorinated and chloraminated drinking water. Although there is an apparent greater association of CNCI with chloraminated water relative to chlorination systems, it was not clear whether these phenomenological observations are explained by differences in the stability or formation potentials of CNCI between the two disinfectants. In this study, the stability of CNCl was examined in the presence of free chlorine and monochloramine using membrane introduction mass spectrometry. CNCI decomposes relatively rapidly when free chlorine is present but is stable in the presence of monochloramine. The decomposition kinetics and observed reaction products are consistent with a hypochlorite-catalyzed hydrolysis mechanism, and the rate law is described by (d[CNCl]/dt) = - kOCl[CNCl][OCl-]. At 25 degrees C, pH 7, and a free chlorine residual of 0.5 mg/L as Cl2, the half-life of CNCl is approximately 60 min, suggesting significant decomposition is expected over disinfection time scales. Under some winter season temperature conditions, however, the decay half-life of CNCl can be longer than typical disinfection contact times. The results of this study demonstrate that the observed association of CNCl with chloramination systems can in part be explained by the differences in its stability with chlorine and chloramines.

Chloramines↗
PubMed1978

Comparison of guinea-pig serum lipoproteins after iodination by two different methods.

1. Guinea-pig low-density lipoproteins were isolated by ultracentrifugation and iodinated either by the IC1 method or by the chloramine-T procedure. 2. The efficiency of labelling by both methods was essentially the same. 3. When the two products were compared by ultracentrifugation, gel chromatography and immunodiffusion analysis, no significant difference in their properties was detected. 4. When they were compared by gradient-gel electrophoresis, aggregates were found in the product of the IC1 method, but not in the lipoprotein iodinated by the chloramine-T process. 5. Both products were metabolized by the guinea pig with essentially the same fractional catabolic rate. 6. The fractional catabolic rate of lipoprotein iodinated by the chloramine-T method was not significantly different from that of lipoprotein biologically labelled in the protein moiety with [75Se]selenomethionine. 7. It is concluded that the products of both methods of iodination are almost equally acceptable, provided that the optimum conditions for the chloramine-T reaction are carefully established.

Animals↗
PubMed1996

Hypochlorous acid/N-chloramines are naturally produced DNA repair inhibitors.

Human mononuclear leukocytes (HML) respond to oxidative DNA damage by activation of ADP ribosylation and initiation of DNA repair synthesis (i.e. unscheduled DNA synthesis, UDS), whereas neutrophils do not. When neutrophils are added to HML cultures in ratios up to 4:1 ADP ribosylation becomes inhibited to approximately 50-60%. The ability of neutrophils to inhibit HML ADP ribosylation was shown to be dependent on H2O2, chloride ions and myeloperoxidase, which in turn are factors known to govern HOCl and N-chloramine production by phagocytic cells. HOCl and a model N-chloramine, chloramine T, were shown to give a dose-dependent inhibition of DNA repair using four independent estimates, namely ADP ribosylation, UDS and the repair of DNA strand breaks estimated by nucleoid sedimentation and alkaline elution profiles. All the DNA repair measurements used on HML were inhibited approximately 70-80% by 100 microM doses of HOCl or chloramine T, which was considered a biologically relevant dose because: (i) viable neutrophils equal in concentration to those found in blood could easily produce 100 microM levels in short-term culture; (ii) 100 microM doses of these agents were not acutely cytotoxic judged by trypan blue stained cells after 30-60 min exposure and under the conditions used for assay, but yet they abolished 86-95% of the growth response of HML to phytohemagglutinin.

Adenosine Diphosphate Ribose↗
PubMed1986

Type of disinfectant in drinking water and patterns of mortality in Massachusetts.

Chlorination has been the major strategy for disinfection of drinking water in the United States. Concern about the potential health effects of the reaction by-products of chlorine has prompted use of alternative strategies. One such method is chloramination, a treatment process that does not appear to have carcinogenic by-products, but may have less potent biocidal activity than chlorination. We examined the patterns of mortality of residents in Massachusetts who died between 1969 and 1983 and lived in communities using drinking water that was disinfected either by chlorine or chloramine. Comparison of type of disinfectant among 51,645 cases of deaths due to selected cancer sites and 214,988 controls who died from cardiovascular, cerebrovascular, or pulmonary disease, or from lymphatic cancer showed small variation in the patterns of mortality. Bladder cancer was moderately associated with residence at death in a chlorinated community (mortality odds ratio = 1.7, 95% confidence interval = 1.3-2.2) in a logistic regression analysis using controls who died from lymphatic cancer. A slight excess of deaths from pneumonia and influenza was observed in communities whose residents drank chloraminated water compared to residents from chlorinated communities, as well as to all Massachusetts residents (standardized mortality ratio = 118, 95% confidence interval = 116-120 for chloraminated communities, and standardized mortality ratio = 98, 95% confidence interval = 95-100 for chlorinated communities). These results are intended to be preliminary and crude descriptions of the relationship under study.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1978

Nitroblue tetrazolium and Limulus assays for bacteremia after dental extraction: effect of topical antiseptics.

Bacteremia that occurs after dental extraction is common. This study assessed the effect of topical antisepsis on the incidence and magnitude of post-extraction bacteremia. On hundred patients scheduled for elective tooth extraction were randomized among four groups: contr-l, mouthrinsing with sodium-p-toluene sulfonchloramide (chloramine-T), toothbrushing with chloramine-T, and irrigation with Lugol's solution. The results showed that 84% of the control group and 59% of the treatment groups had positive blood cultures (290 organisms isolated) after dental extraction. The duration and magnitude of these bacteremias were diminutive as documented by the six serial blood cultures taken for each patient, colony counts per milliliter of blood, and nitroblue tetrazolium and Limulus assays. Brushing the teeth or rinsing the mouth with chloramine-T before dental extraction significantly reduced the incidence of bacteremia (P less than .025) and the number of different organisms recovered from each patient (P less than .05). Thus, topical treatment with chloramine-T is a simple and effective means of reducing the incidence of postextraction bacteremia.

Adolescent↗
PubMed1982

Preparation of 125I-labeled gastric inhibitory polypeptide, using water-insoluble 1,2,4,6-tetrachloro-3 alpha,6 alpha-diphenylglycoluril (Iodo-gen) as the oxidizing agent.

The preparation and evaluation of a 125I-labeled gastric inhibitory polypeptide (GIP) by means of a modified Iodo-gen method are described. The portal vein fasting plasma GIP concentration was determined in 6 groups of rats with 10 rats in each group. In three of the groups, three separately prepared Iodo-gen tracers were used in the radioimmunoassay, and in the three other groups three separately prepared chloramine-T tracers were used. The mean fasting portal vein plasma GIP concentrations in the three groups were 45.0 +/- 5.0, 41.9 +/- 3.9, and 39.6 +/- 2.7 pmol/l, respectively, with the Iodo-gen tracers and 80.3 +/- 4.6, 78.4 +/- 5.4, and 85.7 +/- 3.7 pmol/l with the chloramine-T tracers. The values obtained in each of the groups with the Iodo-gen tracers were significantly lower than those obtained in each of the groups with the chloramine-T tracers. This may be due to a better preserved immunoreactivity of the Iodo-gen tracer than of the chloramine-T tracer. The explanation of this may be the water insolubility of Iodo-gen, which may prevent oxidation of easily oxidized residues of the peptide during the radioiodination procedure.

Animals↗