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At least 973 records · Page 54Linked to original sources
PubMed2000

Factors associated with seeking emergency treatment following suspected chemical contamination of a leisure pool.

A leisure pool was evacuated when children complained of breathing difficulties, cough, and eye irritation subsequently thought to be due to high chloramine levels. The duration of the suspected contamination before the evacuation was unknown: it was suggested that some subsequent attendances at accident and emergency (A&E) departments had been prompted by news reports of the incident. The extent and nature of symptoms, the cause of the incident, and the impact of media reporting were investigated with the help of a postal questionnaire. One hundred and thirty-seven people (all but six under 20 years of age) attended A&E departments after the incident, most commonly with sore eyes (79%), cough (76%), and sore throat (71%). The number of different symptoms was associated with the length of time spent at the pool, but not with being present at the time of the evacuation or with having heard about the incident on radio or television.

Adolescent↗
PubMed1975

[On bacterial aftergrowth in drinking and industrial water. II. Apparative and processing influence upon the growth and the possibility of disinfection of ion exchange resin filter systems (author's transl)].

The comparative examination of numerous ion exchange resin filter systems for discontinuous water softening on the market revealed that apparative and processing characteristics are of great influence upon the aftergrowth of bacteria in the water of ion exchange resin systems. Within the examination it was taken into consideration that on the end-delivery-tube of the water pipe with regard to the colony count the conditions were more unfavourable during the long standstill over a weekend (table 1) than during the week (table2). The less favourable conditions have therefore been examined separately. The work has been divided in six test series. In the first one 5 ion exchange resin systems the types A-E are simultaneously tested with regard to the colony count in the water at the inflow to the apparatus and after the passage of it; regeneration twice a week with sodium chloride. The data ascertained in the course of several weeks (without first data on mondays) and the separated mondays data are examined according to logarithmic transformation with the assistance of variance analysis and the Newman Keuls-test for differences. The results show (tab. 4 and 5) that apparative parameters and such relevant to the technical process (tab. 3) have an influence upon the bacterial after growth of the water. The most favourable ion exchange resin filter is type E because it shows more favourable values than all other systems and the tapwater. In the second test serie the systems A-E have been regenerated with 1% Chloramin T containing sodium chloride. The results show again the type E as the statistically significant most favourable system in comparison with the others and the tapwater. In the third test serie it has been examined whether the long period of standstill of the brine in the resin bed which has probably been responsible for the good results of the type E would lead to values just as favourable if transferred to another type of apparatus. ...

Bacteria↗
PubMed2002

[Decontamination of dental unit waterlines using disinfectants and filters].

Bacterial contamination of the dental unit water system can become a health problem for patients, particularly if they are immunodepressed. The present study has had the purpose of evaluating the effectiveness of methods of chemical decontamination using different disinfectants (peracetic acid, hydrogen peroxide, silver salts, chloramine T, glutaraldehyde T4) and methods of physical decontamination using synthetic membranes for the filtration of water. A preliminary removal procedure of the biofilm present in the waterline has been followed in a dental unit prepared on purpose for the research; subsequently different 2-week long maintenance procedures were applied using disinfectants injected by a pump and finally the bacterial contamination of the water flowing from the waterline was evaluated. The physical decontamination was performed using 0.22 mm membrane filters, which have been installed also in another dental unit, and the filtered water was analyzed to detect bacterial contamination. The preliminary procedure of biofilm removal succeeded obtaining germ-free water. Among the disinfectants used for the maintenance of the water quality only glutaraldehyde T4 was able to reduce the bacterial contamination under the limit suggested by the ADA. The membrane filter system was not able to purify the water, but when a disinfectant (peracetic acid) was used in the last part of the waterline good results were obtained. At present no decontamination system of dental waterline is available, and glutaraldehyde T4 seems to be the best disinfectant only if integrated with periodic biofilm removal for the maintenance of the water quality.

Biofilms↗
PubMed2003

Properties of chemically oxidized kininogens.

Kininogens are multifunctional proteins involved in a variety of regulatory processes including the kinin-formation cascade, blood coagulation, fibrynolysis, inhibition of cysteine proteinases etc. A working hypothesis of this work was that the properties of kininogens may be altered by oxidation of their methionine residues by reactive oxygen species that are released at the inflammatory foci during phagocytosis of pathogen particles by recruited neutrophil cells. Two methionine-specific oxidizing reagents, N-chlorosuccinimide (NCS) and chloramine-T (CT), were used to oxidize the high molecular mass (HK) and low molecular mass (LK) forms of human kininogen. A nearly complete conversion of methionine residues to methionine sulfoxide residues in the modified proteins was determined by amino acid analysis. Production of kinins from oxidized kininogens by plasma and tissue kallikreins was significantly lower (by at least 70%) than that from native kininogens. This quenching effect on kinin release could primarily be assigned to the modification of the critical Met-361 residue adjacent to the internal kinin sequence in kininogen. However, virtually no kinin could be formed by human plasma kallikrein from NCS-modified HK. This observation suggests involvement of other structural effects detrimental for kinin production. Indeed, NCS-oxidized HK was unable to bind (pre)kallikrein, probably due to the modification of methionine and/or tryptophan residues at the region on the kininogen molecule responsible for the (pro)enzyme binding. Tests on papain inhibition by native and oxidized kininogens indicated that the inhibitory activity of kininogens against cysteine proteinases is essentially insensitive to oxidation.

Amino Acids↗
PubMed1992

Oxidant-evoked release of acetylcholine from enteric neurons of the rat colon.

In the presence of halides, granulocytes generate hypochlorous acid and, subsequently, chlorinated amines (chloramines). These lipophilic, potent reactive oxygen metabolites may contribute to the mucosal pathophysiology associated with inflammatory bowel disease. A common symptom of inflammatory bowel disease is mucosal secretion of fluid and electrolytes, leading to diarrhea. Because acetylcholine (Ach) can stimulate colonic fluid secretion, we determined the effect of monochloramine (NH2Cl) on Ach release by mucosal/submucosal nerves. Mucosa from the rat colon was separated from outer muscle layers and minced before incubation with [14C]choline to label stores of Ach in cholinergic neurons. Release of [14C]Ach was evoked with NH2Cl in the absence and presence of 5-aminosalicylic acid, glutathione, nordihydroguaiarectic acid or the cyclooxygenase inhibitor piroxicam. NH2Cl produced concentration-related increases in [14C] Ach release into the medium; greater than 100% over base line was observed at 0.5 mM. Glutathione inhibited the NH2Cl-evoked release in a concentration-dependent fashion. Release induced by 0.1 mM NH2Cl was abolished by 5-aminosalicylic acid and significantly inhibited by nordihydroguaiarectic acid. Piroxicam also prevented the effect of NH2Cl on release of [14C] Ach. None of these agents alone had any effect on base line [14C]Ach release. Tetrodotoxin (5 microM) did not significantly inhibit the NH2Cl-evoked transmitter release. We conclude that NH2Cl, at concentrations believed to exist in inflamed tissue, causes the release of Ach from mucosal/submucosal nerves primarily through nonspecific neural membrane injury. Endogenous prostaglandins, possibly liberated as a consequence of the injury, may be involved in the Ach release process.

Acetylcholine↗
PubMed2005

Factors affecting bacterial growth in drinking water distribution system.

OBJECTIVE: To define the influence of some parameters, including assimilable organic carbon (AOC), chloramine residual, etc. on the bacterial growth in drinking water distribution systems. METHODS: Three typical water treatment plants in a northern city (City T) of China and their corresponding distribution systems were investigated. Some parameters of the water samples, such as heterotrophic plate content (HPC), AOC, COD(Mn), TOC, and phosphate were measured. RESULTS: The AOC in most water samples were more than 100 microg/L, or even more than 200 microg/L in some cases. The HPC in distribution systems increased significantly with the decrease of residual chlorine. When the residual chlorine was less than 0.1 mg/L, the magnitude order of HPC was 10(4) CFU/mL; when it was 0.5-0.7 mg/L, the HPC was about 500 CFU/mL. CONCLUSION: For controlling the biostability of drinking water, the controlling of AOC and residual chlorine should be considered simultaneously. The influence of phosphors on the AOC tests of water is not significant. Phosphors may not be the limiting nutrient in the water distribution systems.

Bacteria↗
PubMedDate not supplied

[Some properties of plasmocoagulase of the causative agents of glanders and melioidosis].

Criteria for the evaluation of the plasmocoagulase activity of natural isolates and mutant strains of the causative agents of glanders and melioidosis were worked out, which made it possible to subdivide them by this sign into pathogens with high, moderate and low activity. Plasmocoagulase produced by pathogenic Burkholderia was shown to be a thermolabile enzyme, comparatively stable with respect to the action of such chemico-biological agents as hydrogen peroxide and chloramine.

Animals↗
PubMed2005

An aminoacridine derivative for radionuclide therapy: DNA binding properties studied in a novel cell-free in vitro assay.

Radiolabelled DNA-binding compounds can be used to increase the efficiency of radionuclide cancer therapy of disseminated disease. In this work, the aminoacridine compound N-[3-(acridine-9-ylamino)-propyl]-3-iodobenzamide (A3) labelled with the Auger-emitting nuclide 125I using Chloramine-T was studied. Optimal labelling conditions of 125I-A3 were investigated and the interaction with DNA was studied using a novel cell-free in vitro assay with naked human genomic DNA in agarose plugs. This novel assay showed to be simple and reliable. The results verify that 125I-A3 specifically binds DNA with low dissociation and is potent in causing double-strand breaks, yielding 1.0-1.4 breaks per decay. In conclusion, 125I-A3 is a most suitable DNA-binding compound for future therapeutic studies of Auger-electron emitters like 125I.

Acridines↗
PubMed2005

[Optimal process combination for control of disinfection by-products and precursors].

It is compared that the efficiency of control disinfection by-products and their precursors by sequential-chlorination disinfection and traditional free chlorination disinfection following different processes combination. Compared with traditional chlorination, sequeutial chlorination, i. e. short-term free chlorine plus chloramine disinfection can lower 35.8% - 77.0% of trihalomethane formation and 36.6% - 54.8% of haloacetic acids formation. Moreover, the poorer the influent quality is, the more advantages sequential chlorination disinfection have over free chlorination disinfection. The formation of trihalomethane and haloacetic acids by sequential chlorination following the simplest traditional process is even less than their formation by free chlorination following the most complex process, pre-ozonization plus traditional one and ozonization-active carbon process. The results show that ozonization-active carbon process and pre-ozonization have better efficiency on control of disinfection by-products and their precursors. We recommend that water plants apply the sequential chlorination disinfection and ozonization-active carbon process.

Acetic Acid↗
PubMed1991

Differential effects of reactive oxygen metabolites on neurally stimulated and nonstimulated guinea pig ileum.

Large numbers of polymorphonuclear leukocytes which generate reactive oxygen metabolites are found in mucosa and submucosa of the intestinal wall of subjects suffering from inflammatory bowel disease. We have, therefore, examined the relative influences of hydrogen peroxide (H2O2), hypochlorous acid (HOCl) and N-chloramines such as NH2Cl, on the neurally stimulated and nonstimulated guinea pig ileum. In separate experiments the oxidants were tested in the presence and absence of the cyclooxygenase inhibitor piroxicam and the antioxidant glutathione. All three oxidants, in concentrations produced by activated neutrophils, increased the muscle tone (concentration-dependent, peak at 0.3 mM for NH2Cl and H2O2 and 1 mM for HOCl). Tetrodotoxin (0.5 microM) inhibited the NH2Cl and H2O2 effects by 50% and 70%, respectively. Piroxicam (5 microM) partially blocked maximal contractions induced by all three oxidants. The contractile response to carbachol (10 microM) was blocked by 0.3 mM NH2Cl, but not by H2O2 and HOCl. In electrically stimulated ileum the oxidants produced a concentration-dependent biphasic response (transient enhancement of neurally mediated twitch contraction followed by marked inhibition). This response was not modified by piroxicam, hexamethonium, atropine and pyrilamine. The inhibition of twitch contraction was irreversible for NH2Cl and HOCl, in contrast to H2O2, which was reversed by repeated washing. Neither the contractile effect nor the effects on nerve stimulation-induced contraction were affected by preincubation of the tissue with glutathione, whereas prior combination of NH2Cl with glutathione prevented the effects of NH2Cl. Oxidant-induced contraction of guinea pig ileum appears to be via release of prostaglandins and one or more neurotransmitters. High concentrations of reactive oxygen metabolites may alter receptor function.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Sensitivity of surface microorganisms to disinfectants].

The influence of humidity and temperature on survival of S. aureus and P. aeruginosa on the surfaces of titles, glass and blanket carriers has been estimated. The number of CFU was examined after exposure time 6 and 24 hours in temperatures of 21 degrees C, 37 degrees C and RH 35%, 95%. It was observed: 1. The important reduction of numbers of both microorganisms at temperature 37 degrees C and RH 95%, 2. The relatively high number of survival cells of P. aeruginosa on the surface of blankets at temp. 21 degrees C and RH 95%. The microorganisms on the carriers were previously kept for 24 h at temp. 21 degrees C, RH 35% and 95% and then exposed to solutions of chloramine, formalin, lysol and Sterinol (QAC). It was observed that there was a great dependence of the disinfecting effect on the degree of dessication of the surfaces. In all cases the resistance of contaminated carriers stored 24 h was higher at 95% RH than at 35% RH.

Bedding and Linens↗
PubMed1990

Alpha 1-antitrypsin variants produced by recombinant DNA: differences in elastase inhibitory activity and resistance to oxidant agents.

Inherited or "acquired" deficiency of alpha 1-antitrypsin (believed to be the cause of pulmonary emphysema) will probably be treated in the future by replacement with alpha 1-antitrypsin purified from human plasma or produced by recombinant DNA, which seems promising because it permits site-specific mutagenesis in the oxidizable active site of the normal human alpha 1-antitrypsin. The aim of this in-vitro study was to investigate the elastase inhibitory activity and the resistance to oxidizing agents of normal human alpha 1-antitrypsin, a recombinant yeast-produced variant (VAL 358) and a recombinant E. coli-produced variant (LEU 358). The inhibitors were exposed to chemical oxidants (NCS, H2O2, xanthine/xanthine oxidase, chloramine-T) and to PMA-activated neutrophils. The elastase inhibitory activity was assayed on porcine pancreatic elastase and neutrophil elastase. Normal alpha 1-antitrypsin and VAL 358 variant were good inhibitors of both elastases. LEU 358 variant was the best inhibitor for neutrophil elastase, but it poorly inhibited the porcine pancreatic elastase. Normal alpha 1-antitrypsin was affected by all oxidants; both variants were almost totally resistant to chemical oxidants and to activated neutrophils. We conclude that recombinant alpha 1-antitrypsin variants differ in their elastase inhibitory activity and offer increased resistance to oxidant agents.

Animals↗
PubMed1986

Sodium current and gating current experiments on the node of Ranvier.

Sodium tail currents of the frog node of Ranvier were recorded at different postpulse potentials. Inactivation was inhibited with chloramine-T. At E greater than -60 mV the tail currents decayed with two time constants, tau 1 and tau 2, reflecting presumably the turning-off and the inactivation of the sodium permeability. In the potential range -42 to -12 mV tau 1 (thought to equal tau m off) was not significantly different from the time constant of the turning-on of sodium activation m, tau m on. Similarly, no significant difference between tau on and tau off of the gating current was found if both were measured at the same potential.

Animals↗
PubMed1988

Quality control of 125I-labelled fibrinogen of various species.

The modified chloramine-T method used for radioiodination of human, rat, and bovine fibrinogen guaranteed mild labelling conditions and a satisfactory labelling efficiency. The quality of the 125I-human, rat, and bovine fibrinogen preparations obtained met the requirements with respect to clottability, low content of 125Iodide as well as in vitro and in vivo stability.

Animals↗
PubMed1989

[Tactics in using aerosols for disinfection of therapeutic and prophylactic institutions].

Two Soviet sprayers (ABD-2600H and EOC-5) are recommended for the disinfection of the surfaces and indoor air in the curative and prophylactic facilities. A special impetus has been given to the use of chloramine aerosols that ensure higher efficacy of disinfection, reduce the aerosol consumption and the period of the presence of active chlorine in the air of the treated place.

Aerosol Propellants↗
PubMed1986

Some physical and chemical properties of Bhanja virus.

Bhanja virus is acid-labile, relatively thermostable, resistant to trypsin and heparin; a complete inactivation was achieved with chloramine B or formaldehyde, while phenol was ineffective, and UV radiation only partially effective.

Animals↗
PubMed1986

[mono[125I]iodo-Tyr10,MetO17]-vasoactive intestinal polypeptide. Preparation, characterization, and use for radioimmunoassay and receptor binding.

Vasoactive intestinal polypeptide (VIP) was labeled with sodium [125I]iodide using the chloramine-T method and subsequently purified by reverse-phase high performance liquid chromatography. Three main 125I-labeled peaks designated A, B, and C resulted from the radioiodination and purification procedures. They were characterized by electrophoresis of tryptic fragments; Edman degradation (for Peaks A and C); enzymatic digestion to amino acids by leucine aminopeptidase, carboxypeptidase Y and Pronase; and treatment with cyanogen bromide. Peak A corresponds to VIP monoiodinated on Tyr10 and with the Met17 residue oxidized to methionine sulfoxide. This [mono[125I]iodo-Tyr10,MetO17]VIP displays the following characteristics. 1) It constitutes quantitatively the major product of the iodination procedure (62.5%); 2) it is well resolved from other labeled and unlabeled products; 3) it is stable (2 months at -20 degrees C); 4) it possesses a high specific activity (2050 Ci/mmol); 5) it maintains the biological activity of native VIP; and 6) it binds to antibody and membrane recognition sites in a specific, saturable, and reversible manner. Reduction of [mono[125I]iodo-Tyr10, Met-O17]VIP to [mono[125I]iodo-Tyr10]VIP does not improve the performance of the tracer in a radioimmunoassay. The method described in this article is simple and rapid and yields a molecular form of 125I-labeled VIP that has been fully characterized and is suitable for use in biological studies.

Animals↗