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PubMed2004

Evaluation of techniques for control of disinfection by-products: a pilot study.

The purpose of this study was to evaluate the effects of various treatment processes as they relate to the development of disinfection by-products (DBPs). At an existing municipal water supply, several tests were performed, including: air-stripping, potassium permanganate (KMnO4) addition, pH adjustment, evaluation of corrosion control inhibitors, final disinfection, and granular activated carbon (CAC) filtration. Several HAAs were shown to increase at higher pH. The use of air stripping greatly reduced the required amount of chlorine disinfectant. Air stripping, permanganate addition, and chloramination reduced DBPs below 20 microg/L. Stiles-Kem 7840 addition effectively controlled lead and copper concentrations in the distribution system. The use of chloramination its a secondary disinfectant is recommended to meet stage 1 of the disinfection by-product rule.

Chloramines↗
PubMed2001

Oxidative regulation of large conductance calcium-activated potassium channels.

Reactive oxygen/nitrogen species are readily generated in vivo, playing roles in many physiological and pathological conditions, such as Alzheimer's disease and Parkinson's disease, by oxidatively modifying various proteins. Previous studies indicate that large conductance Ca(2+)-activated K(+) channels (BK(Ca) or Slo) are subject to redox regulation. However, conflicting results exist whether oxidation increases or decreases the channel activity. We used chloramine-T, which preferentially oxidizes methionine, to examine the functional consequences of methionine oxidation in the cloned human Slo (hSlo) channel expressed in mammalian cells. In the virtual absence of Ca(2+), the oxidant shifted the steady-state macroscopic conductance to a more negative direction and slowed deactivation. The results obtained suggest that oxidation enhances specific voltage-dependent opening transitions and slows the rate-limiting closing transition. Enhancement of the hSlo activity was partially reversed by the enzyme peptide methionine sulfoxide reductase, suggesting that the upregulation is mediated by methionine oxidation. In contrast, hydrogen peroxide and cysteine-specific reagents, DTNB, MTSEA, and PCMB, decreased the channel activity. Chloramine-T was much less effective when concurrently applied with the K(+) channel blocker TEA, which is consistent with the possibility that the target methionine lies within the channel pore. Regulation of the Slo channel by methionine oxidation may represent an important link between cellular electrical excitability and metabolism.

Animals↗
PubMed1997

Evaluation of bactericidal activity and lag of regrowth (postantibiotic effect) of five antiseptics on nine bacterial pathogens.

Lag of regrowth or postantibiotic effect (PAE) relates to suppression of bacterial regrowth following short exposure to an antimicrobial agent. A delay in regrowth has not yet been studied for antiseptics to any great extent. We therefore examined and compared the lag of regrowth and the bactericidal activity of five antiseptics (chloramine T, chlorhexidine, povidone-iodine, phenoxyethanol and mandelic-lactic acid) against nine bacterial pathogens. Delay in regrowth was determined by application of two concentration-time schedules: a test concentration at the MBC with a contact time of 1 h or using fixed suboptimum concentration of each antiseptic for 2 min (optimum concentrations sterilized the culture, impeding assessment of regrowth) followed by a neutralization-dilution step and subsequent viable counting to follow bacterial regrowth. Each antiseptic displayed a different spectrum of activity in terms of MIC or MBC, bactericidal effect and lag of regrowth. The delay in regrowth varied from 0 to 5.7 h with only a few discrepancies between the two treatment schedules. Mandelic-lactic acid and chloramine T induced a significantly longer lag as compared with the other agents, whereas phenoxyethanol produced the shortest lag values. No significant correlation between the killing rate and the lag of regrowth could be demonstrated. Information on bactericidal activity, as well as lag of regrowth, could be a useful screening method for the efficacy of antiseptics. Moreover, data on lag of regrowth could contribute to the choice of antiseptic and guide in determining the optimum interval between repeated applications of antiseptics.

Anti-Infective Agents, Local↗
PubMed2003

Methaemoglobinaemia and haemolysis associated with hydrogen peroxide in a paediatric haemodialysis centre: a warning note.

BACKGROUND: Haemodialysis exposes patients to contaminants in the dialysate. The AAMI standards deal only with two disinfectants, chlorine and chloramine. We report an event of methaemoglobinaemia and haemolysis related to an unsuspected disinfection agent. METHODS: Nine children aged 3-17 years undergoing dialysis after reconstruction of our paediatric dialysis unit developed methaemoglobinaemia of 3.1-11%, with a mean reduction in haemoglobin levels of 11.9 +/- 5.9% (P < 0.001). Air bubbles were noted in the bloodlines. The water treatment system (WTS) of the dialysis unit is disinfected when necessary by adding concentrated hydrogen peroxide (HP) to the storage tank and circulating it through the re-circulation loop with draining and subsequent flushings. Total chlorine analysis of the water is performed by DPD-iodide colorimetric method. RESULTS: Dialysis water testing yielded a high chloramine concentration in the storage tank and points- of-use stations (3.08 and 2.06 p.p.m., respectively). However, this finding was not true for the tap water, and it also failed to explain the air bubbles in the dialysis tubing. The concentration of free chlorine was within the recommended range. Further investigation revealed that the WTS was disinfected by the service company during remodelling of the unit, without notification of the hospital staff. Since the DPD-iodide test is not specific, and in effect detects not only total chlorine, but all oxidants capable of oxidizing iodide, we assumed the culprit was residual HP that was inadequately flushed from the water system. CONCLUSIONS: HP used for disinfection of the WTS can pose a serious dialysis risk if not flushed out properly. Total chlorine analysis should be performed before every dialysis session, and positive results should prompt further work-up for other oxidants. The clinical staff must always be involved in decisions regarding any intervention in the dialysis water system.

Adolescent↗
PubMed1982

Radioactive iodination of lymphocyte surface proteins and characterization of their molecular properties.

Two radioiodination methods for surface proteins on mouse lymphocyte membrane, that is, the lactoperoxidase method and the chloramine T method, were comparatively investigated. The extents of iodination under various conditions were determined by measurements of radioactivities incorporated into the cell fractions and into the protein components isolated by specific immunoprecipitation from lyzates of the labeled cells. It was demonstrated that the chloramine T method, as well as the lactoperoxidase method, was applicable to label the lymphocyte surface proteins without any significant labeling of the cytoplasmic proteins. It was also found that the iodination efficiencies of the membrane immunoglobulin polypeptide chains in these two labeling methods were different in each of the isotopes, mu and delta chains. The possibility that the differences are related to their primary structures and to their exposure or anchorage profiles on the cell membrane is discussed with reference to the reaction mechanisms of the two labeling methods.

Animals↗
PubMed1993

Home exposures to chlorine/chloramine gas: review of 216 cases.

Chlorine and chloramine gas are frequently produced in the home when cleaning products are mixed. These gases are strong irritants with the potential for tissue damage. Numerous literature citations report industrial exposures to chlorine/amine gas, but there are few reports regarding home exposures. The purpose of this study was to determine symptoms, treatment, and outcome in individuals exposed to these gases in the home. All exposures to chlorine/amine gas produced as a result of mixing cleaning products in the home and reported to a Regional Poison Information Center (RPIC) over a 12-month period were reviewed. All calls were documented and follow-up was done at appropriate intervals. All patients with respiratory embarrassment either at the initial contact or on follow-up were referred to a medical facility. Of the 216 patients (ages 12 to 81 years), 200 had resolution of symptoms within 6 hours, whereas only 16 had symptoms for more than 6 hours after exposure; 145 patients were treated at home and 71 received further medical care. Ten symptoms were identified, with the majority of patients experiencing more than one. Emergency room treatment included oxygen (62 patients), bronchodilators (9 patients), and steroid therapy (3 patients). Of the 70 patients who had chest x-ray films, only one had a positive finding; 41 had arterial blood gas measurements done, and all were within normal limits. Only one patient in the study group required admission for continued respiratory distress, but he had a preexisting chronic respiratory problem as well as an upper respiratory tract infection at the time of exposure. Although the gas produced by mixing cleaning products in the home can cause severe respiratory irritation, most of the patients exposed to chlorine and chloramine gas can safely be treated at home with comfort measures. Appropriate follow-up must be done to determine resolution of symptoms.

Adolescent↗
PubMed1980

Biological evaluation of root canal antiseptics using in vitro and in vivo methods.

Five antiseptics commonly used in endodontic treatment were evaluated with regard to cytotoxicity and initial tissue irritating effect. The cytotoxicity was evaluated in a cell culture system using HeLa cells and the initial tissue irritating effect was assessed by application of the antiseptics onto an intact nonepithelialized tissue surface. The cell response was assessed by registering changes in the DNA synthesis of the cells and the tissue response was assessed by registering changes in the oxidoreductase enzyme activity of the tissue. To evaluate the ability of the cells and the tissue to overcome an induced damage, one part of the study included a recovery period before the condition of the cells and the tissue was assessed. The most severe cell and tissue reactions were caused by 5% Chloramine-T whereas no differences in toxicity or tissue irritating effect were found between 0.04% Jodopax, 0.1% Biosept, 0.1% Hibitane, or 0.5% sodium hypochlorite. The HeLa cells showed the best recovery after having been influenced by Jodopax, Chloramine-T or sodium hypochlorite solutions, whereas the best tissue recovery was observed in the experiments with Biosept and Hibitane.

Acetrizoic Acid↗
PubMed1985

Influence of antiseptic storage solutions on physical properties of endodontic guttapercha points.

The effect of three commonly used antiseptic storage solutions on some physical properties of endodontic guttapercha points was studied. The solutions tested were: 70% isopropyl alcohol, 5% chloramine and 0.5% chlorhexidine. As a control solution, physiologic saline was used. There was a marked decrease in the force necessary to bend the points after 1 month. With few exceptions, the greatest decrease was seen with solutions containing alcohol, i.e. chlorhexidine and isopropyl alcohol. The difference between aqueous and alcoholic storage solutions was also noted for linear dimensional changes. Physiologic saline and chloramine hardly affected the length of the points. The decrease in stiffness may add to the difficulties when handling guttapercha points of small dimensions in curved root canals. From this point of view it is therefore recommended to avoid storage of points in antibacterial solutions. Rather, an effective surface disinfecting of the points immediately prior to use would be desirable.

1-Propanol↗
PubMed1973

Chlorinated urban water: a cause of dialysis-induced hemolytic anemia.

Unexplained acute hemolytic anemia is sometimes seen in uremic patients undergoing hemodialysis. Chloramines, which are oxidant compounds made up of chlorine and ammonia and are widely used as bactericidal agents in urban water supplies, have been found responsible for two recent epidemics, in dialyzed uremic patients, of acute hemolytic anemia characterized by Heinz bodies. Chloramines produce denaturation of hemoglobin, both by their direct oxidizing capacity and their ability to inhibit red cell reductive (hexose monophosphate shunt) metabolism.

Anemia, Hemolytic↗
PubMed1977

Comparison of I-bleomycin prepared by two methods stability and pharmacokinetics in tumor-bearing mice.

Bleomycin, a chemotherapeutic antibiotic agent, was radio-iodinated by the ICI and chloramine-T methods; the radiochemical stabilities and pharmacokinetics of the two I-bleomycins in tumor-bearing mice were compared. The ICI preparation was more stable with respect to deiodination in vitro. Both products were sufficiently stable in vivo that high body background due to free isotope, a disadvantage of 111In- and 99mTc-bleomycin, was not encountered. Tumor uptake of the ICI preparation was constant from 2 to 24 hrs., and the tumor/blood ratio increased with time; with chloramine-T, this ratio decreased, and was less than that for ICI. The two preparations are chemically and biologically different; the ICI product is the superior tumor radiodiagnostic agent.

Animals↗
PubMed2006

Influence of different storage methods on laser fluorescence values: a two-year study.

The aim of this study was to assess the influence on the infrared laser fluorescence response of some storage methods commonly used in dental research. Forty extracted permanent teeth, selected from a pool of frozen teeth, were divided into four groups of 10. Three groups were stored at 4 degrees C in 1% chloramine, 10% formalin or 0.02% thymol solution. The fourth group was stored at -20 degrees C (no storage solution added). Fluorescence measurements were performed at 14, 77, 113, 168, 232, 486 and 737 days. After 2 years, significant decreases in fluorescence (p<0.01) for the samples in formalin (-60%), chloramine (-72%) and thymol (-54%) were observed. The frozen teeth showed a slight but non-significant increase in fluorescence of 5% (p>0.01). Storing solutions have a significant influence on the fluorescence yield. Samples used for in vitro purposes stored frozen do not significantly change their fluorescence response. Thus, cut-off values obtained under the latter conditions could be extrapolated to the in vivo situation.

Chloramines↗
PubMed1980

Effect of radioiodination on the structural integrity, receptor and antibody-binding activity and circulatory behavior of human choriogonadotropin.

Human choriogonadotropin (hCG) was labelled with 125I using a low temperature (4 degrees C), minimal chloramine-T (10 micrograms) concentration and 20-sec oxidization. The structural integrity of labelled hCG was analyzed immediately after the labelling as well as after storage for 7 and 14 days at 4 or -15 degrees C by gel filtration on a Sepharose 6B and Sephadex G-200 column and by polyacrylamide gel electrophoresis. Gel filtrations of freshly labelled hCG revealed a single radioactive peak (Kav = 0.52 and 0.33) corresponding to the intact unlabelled hCG. Polyacrylamide gel electrophoresis also showed a high homogenity of labelled hormone. The capability of freshly labelled hCG to bind to LH(hCG) receptor was 51% and to anti-hCG gamma-globulin Sepharose 4B, 94%. Storage for 14 days at 4 degrees C caused a complete change of the molecule to a smaller conformation (Kav = 0.62 and 0.41) accompanied by a marked reduction in the binding to LH(hCG) receptor (12%). The binding to specific antibody remained high (75%). No change in the structure was found when the labelled hormone was stored for 14 days at -15 degrees C. The hormones also exhibited high binding to the LH(hCG) receptor (45%) and to specific antibody (86%). SDS-polyacrylamide gel electrophoresis indicated that over 90% of the radioiodine present in labelled hCG was associated with the alpha-subunit. No difference was found in the disappearance rate of freshly labelled and fresh unlabelled hCG from the circulation of the rat after a single intravenous injection. The rate of disappearance of the structurally changed hormone was, however, markedly increased and was found to be due to the higher uptake of the hormone by the kidneys and liver. The present observations indicate that hCG retains well its structural integrity and capability to bind to LH(hCG) receptor and specific antibody when radioiodinated with the chloramine-T method. However, there occurs a rapid structural change in labelled hormone molecules under storage at 4 degrees C leading to a smaller conformation, a marked reduction in its binding capability to LH(hCG) receptor and altered metabolic clearance in the rat.

Animals↗
PubMed1997

Tumoricidal activity of antiseptics with assessment of cell viability in mice with severe combined immunodeficiency.

Previously, we have assessed the efficacy of different cytotoxic agents on the viability of SW620 human colonic carcinoma cells in vitro. In this study, we have investigated the tumoricidal efficacy of some antiseptic agents on SW620 human colonic carcinoma cells which were subsequently inoculated into severe combined immunodeficient (SCID) mice. An inoculum of 5 x 10(6) cells suspended in 200 microliters buffer solution was found to be the minimum number of cells needed to result in tumour growth within 8 weeks after subcutaneous injection into SCID mice. The integrity of the cells was assessed in vitro with the trypan blue exclusion test after 30 min incubation in distilled water (DW), chloramine 0.5% in DW and polyvinyl pyrrolidone iodine (PVP-I) 0.01, 0.05, 0.1 and 5% in DW. DW and PVP-I 0.01% were not tumoricidal, neither in vitro nor in vivo. In contrast, PVP-I 5% and chloramine 0.5% 'killed' all or almost all tumour cells in vitro and prevented their growth in vivo. PVP-I 0.05 and 0.1% were less effective in vitro than 5%, but could prevent in vivo proliferation unless an adjustment of the residual number of viable tumour cells was performed. These data indicate the importance of the amount of the tumour inoculum and hence the need to use a maximally effective 'killing' agent.

Animals↗
PubMed1992

Dangerous mixture of household detergents in an old-style toilet: a case report with simulation experiments of the working environment and warning of potential hazard relevant to the general environment.

A housewife cleaned toilet porcelain connected directly to a sewage storage tank with a mixture of cleaning agents; sodium hypochlorite (NaOCl) and hydrochloric acid (HCl) solutions. She complained of insomnia on the night after cleaning and suffered from severe metabolic acidosis with extremely low blood pH, PCO2 and bicarbonate values. She recovered from the acidosis after bicarbonate transfusion, plasmapheresis and plasma exchange. Permanent blindness ensued, however, from the third day after the event. These clinical symptoms suggested that the toxic substances responsible were chloramine and methyl chloride. Their generation was confirmed by in-vitro experiments, mixing NaOCl, HCl and pooled urine from normal people. In the simulation, the methyl chloride level far exceeded (100,000 ppm) the maximal allowable concentration recommended (ca 400 ppm) by the American Conference of Governmental Industrial Hygienists (ACGIH). Chloramine's toxic actions were confirmed using purified enzyme assay, and the inhibition of carbonic anhydrase and aldehyde dehydrogenase and the enhancement of superoxide dismutase activity were confirmed in neutral pH. The patient's clinical symptoms suggested that insomnia and permanent blindness seemed to be partly ascribable to chronic repetitive exposure to methyl chloride; catching a cold, drug intake and alcohol intake, in addition, precipitated the patient's visual loss. The possibility of this kind of intoxication with such a mixture of agents may lie latent in any situation where sewage or garbage are exposed to the open air.

Acidosis↗
PubMed2005

Functional determination of plasminogen activator in arginine-stabilized plasma.

Reliable data on plasminogen activator (PA) activities in blood of patients receiving fibrinolytic treatment are lacking. This is due to the continuing in vitro action of PA after blood withdrawal. We have elaborated a new simple stabilization technique for plasma involving the addition of arginine in final concentrations greater than 500 mM. In this study, new assays for PA in stabilized plasma are developed. The assay was performed with substrate plasma, that is, pooled normal plasma, preoxidized with chloramine-T; oxidant amount and oxidation time were optimized. The chloramine consumption by plasma was assayed with a KJ-assay (absorbance increase at 405 nm by addition of 200 microL 4 M KJ to 25 microL oxidized plasma). The substrate plasma concentration in the PA assay and the PA acting time was optimized. The inhibition of PA by the cations Na(+), K(+), Mg(2+), and Ca(2+) was evaluated. The optimized PA assay consists of incubation of 10 microL arginine-stabilized plasma with 10 microL 1.5 M arginine, pH 8.7 and 10 microL 100 mM CT in PBS. After 30 minutes (37 degrees C), 175 microL 15 mM CT oxidized EDTA plasma are added. After 40 minutes (37 degrees C), 75 microL Stop-CS Reagent is added and DeltaA at 405 nm was determined, giving PA + plasmin activity in plasma. A control value (basal plasmin activity) consists of the addition of Stop-CS Reagent before 175 microL oxidized EDTA plasma. To obtain plasmatic PA activity, the control value has to be subtracted from the PA main value. The assay is matrix-independent and linear up to 1250 IU/mL t-PA, 790 U/mL reteplase, or 199 IU/mL u-PA (37 nM). With arginine stabilization of plasma and the described determination of plasminogen activator activity in arginine-stabilized plasma, it is feasible to determine the activity of plasminogen activators in blood of patients receiving fibrinolytic treatment without artefactual in vitro changes of the samples.

Arginine↗
PubMed1997

Comparative loss of activity of recombinant secretory leukoprotease inhibitor and alpha 1-protease inhibitor caused by different forms of oxidative stress.

Secretory leukoprotease inhibitor (SLPI) and alpha 1-protease inhibitor (alpha 1-PI) are powerful antiproteases currently under investigation for their potential to protect the lung from neutrophil elastase (NE). The aim of this study was to determine whether the recombinant form of SLPI (rSLPI) and alpha 1-PI show different grades of loss of inhibitory activity when exposed to reactive oxygen metabolites. We incubated rSLPI and alpha 1-PI with N-chlorosuccinimide (NCS), chloramines, activated polymorphonuclear leucocytes (PMNs) and activated alveolar macrophages (AMs). Under all conditions evaluated, both antiproteases were partially inactivated. The resulting anti-NE activity of rSLPI was not significantly different from that of alpha 1-PI after exposure to NCS (p > 0.5), chloramines (p > 0.6), activated PMNs (p > 0.07) and activated AMs (p > 0.9). In conclusion, recombinant secretory leukoprotease inhibitor and alpha 1-protease inhibitor lose antineutrophil elastase activity to a similar extent when exposed to conditions that may be present in inflammatory lung disorders.

Animals↗
PubMed1986

Occurrence of by-products of strong oxidants reacting with drinking water contaminants--scope of the problem.

This paper describes results of a detailed literature review of the organic and inorganic by-products that have been identified as being formed in aqueous solution with four of the strong oxidizing/disinfecting agents commonly employed in drinking water treatment. These agents are: chlorine, chlorine dioxide, chloramine, and ozone. Significant findings include the production of similar nonchlorinated organic oxidation products from chlorine, chlorine dioxide, and ozone. In addition, all three chlorinous oxidants/disinfectants can produce chlorinated by-products under certain conditions. The presence of chloronitrile compounds in drinking waters is indicated to arise from reactions of chlorine or chloramine to amine/amide functions in amino acids or proteinaceous materials, followed by dehydrohalogenation. These nitriles could hydrolyze to produce the corresponding chloroacetic acids. It is concluded that to minimize the presence of oxidation by-products in drinking waters, the concentrations of oxidizable organic/inorganic impurities should be lowered before any oxidizing agent is added.

Chemical Phenomena↗
PubMed1986

Effects of disinfectants in renal dialysis patients.

Patients receiving hemodialysis therapy risk exposure to both disinfectants and sterilants. Dialysis equipment is disinfected periodically with strong solutions of hypochlorite or formaldehyde. More recently, reuse of dialyzers has introduced the use of additional sterilants, such as hydrogen peroxide and peracetic acid. The use of these sterilants is recognized by the center staffs and the home patient as a potential risk, and residue tests are carried out for the presence of these sterilants at the ppm level. Gross hemolysis resulting from accidental hypochlorite infusion has led to cardiac arrest, probably as a result of hyperkalemia. Formaldehyde is commonly used in 4% solutions to sterilize the fluid paths of dialysis controllers and to sterilize dialyzers before reuse. It can react with red cell antigenic surfaces leading to the formation of anti-N antibodies. Such reactions probably do not occur with hypochlorite or chloramines. The major exposure risk is the low concentration of disinfectant found in municipal water used to prepare 450 L dialysate weekly. With thrice-weekly treatment schedules, the quality requirements for water used to make this solution must be met rigorously. Standards for water used in the preparation of dialysate have recently been proposed but not all patients are treated with dialysate meeting such standards. The introduction of sterilants via tap water is insidious and has led to more pervasive consequences. Both chlorine and chloramines, at concentrations found in potable water, are strong oxidants that cause extensive protein denaturation and hemolysis. Oxidation of the Fe2+ in hemoglobin to Fe3+ forms methemoglobin, which is incapable of carrying either O2 or CO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Chloramines↗