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PubMed1980

Studies on hyaluronic acid from the electric organ of Electrophorus electricus (L.).

This report deals with on optical rotatory dispersion and viscosity study of hyaluronic acid with the electric organ of Electrophorus electricus (L.). This acidic polysaccharide exhibits an intrinsic Cotton effect (negative) around 212 nm in aqueous solutions. Extrinsic Cotton effects are developed by its interaction with cationic dyes which is an indication of ordered conformation in solution involving the polymer anionic sites. Viscosity measurements showed that hyaluronic acid behaves, in solution, as a polyelectrolyte with a decrease in intrinsic viscosity in media of high ionic strength and of low dielectric constant. With the quaternary ammonium compounds acetylcholine and gallamine triethyliodide, this polyelectrolyte also displays an interaction which affects both its optical rotatory dispersion and viscosity properties which is indicative of a conformational change.

Acetylcholine↗
PubMed1980

Transport of choline out of the cranial cerebrospinal fluid spaces of the rabbit.

The role which carrier-mediated transport and passive diffusion play in the clearance of quaternary ammonium compounds from cerebrospinal fluid was evaluated by ventriculocisternal perfusion in rabbits by using [14C]choline as the primary test compound. Choline was transported out of cerebrospinal fluid by two processes: a saturable, carrier-mediated process with a Tmax of 70.5 ng/min and Kt of 2.2 microgram/min; and, a passive nonsaturable process with a cerebrospinal fluid perfusate clearance of 11.5 microliter/min. N1-methylnicotinamide depressed the clearance of choline as well as that of hexamethonium, suggesting that these cations share a common transport process. Ouabain reduced the clearance of choline and hexamethonium. Passage of choline into brain occurred by passive diffusion.

Animals↗
PubMed1995

Efficacy and contamination of in-use disinfectants in Rajavithi General Hospital.

Quality testing of disinfectant in-use in Rajavithi General Hospital was conducted to evaluate the germicidal activity and contamination. Two hundred and thirty-four samples of 4 commonly used disinfectants in operating rooms, labour rooms and the surgical intensive care unit were studied. Results showed that 2 of 126 samples of chlorhexidine/cetrimide 1:100 dilution were contaminated by P.maltophilia and A.xylosoxidans and failed the in-use test. One of 34 samples of phenolics yielded A.lowffii. Two of 16 hypochlorite 0.05% grew E.cloacae, Enterobacter spp., A.calcoaceticus and Pseudomonas spp. Forty-six samples of 1:500 and 1:100 of quaternary ammonium compound, and 12 samples of 1% hypochlorite were not contaminated. Bacterial contamination and failure to kill bacteria by disinfectants reflected improper preparation and use of these solutions. Periodic quality testing is clearly indicated.

Disinfectants↗
PubMed1994

Effects of bretylium tosylate on voltage-gated potassium channels in human T lymphocytes.

Using the patch-clamp technique, we determined that bretylium tosylate, a quaternary ammonium compound possessing immunomodulating activity, decreased the whole-cell K+ current in human T lymphocytes, in a dose-dependent manner, in the 0.05-5 mM extracellular concentration range. Bretylium tosylate prolonged the recovery from inactivation and accelerated the inactivation and deactivation of the K+ current but did not influence the kinetics of activation or the voltage dependence of activation and steady state inactivation of the K+ conductance. The percentage of drug-induced block was independent of membrane potential. K+ channel block by bretylium tosylate was partially and slowly removable by washing with drug-free extracellular solution. Bovine serum albumin (10 mg/ml) in the bath lifted the drug-induced block almost instantaneously, although not completely. In control experiments bovine serum albumin increased the inactivation time constant of the K+ channels but left the peak K+ current amplitude unaffected. On the basis of the experimental evidence, a gating-dependent allosteric interaction is suggested for the mechanism of drug action. The effective dose range, time of exposure, and reversibility of bretylium tosylate-induced K+ channel block correlated well with the same parameters of the drug-induced inhibition of T lymphocyte activation. The reported effects of bretylium tosylate on T cell mitogenesis can be regarded partly as a consequence of its blocking effects on voltage-gated K+ channels.

Bretylium Tosylate↗
PubMed1994

Toxic mechanism of bromate poisoning in a dog: a case study.

Efforts to link the observed signs in a canine poisoning event with 1 or more possible permanent wave solution chemicals ingested are described. A scenario is presented describing the mechanisms by which the most likely of those compounds, ammonium thioglycolate and sodium or potassium bromate, could have acted to cause both the immediate and delayed signs of acute vestibular dysfunction.

Animals↗
PubMedDate not supplied

Effect of UVB and AS101 on interleukin-2 production and helper activity in psoriatic patients.

Peripheral blood lymphocytes were obtained from eight untreated patients suffering from long-standing plaque-type psoriasis 1 h following UVB treatment and at the end of 15 UVB treatments. Before treatment and following in vivo treatment with 0.01-0.3 J/cm2, the patients' lymphocytes were tested for interleukin-2 (IL-2) production, and helper activity with and without addition of the immunomodulator AS101. AS101 is a synthetic organotellurium compound, ammonium trichloro-(O,O'-dioxyethylene) tellurate. UVB at a flow of 0.01 J/cm2 did not affect any of these functions. However, after 15 UVB treatments, when the dose given had reached 0.3 J/cm2, a complete inhibition of IL-2 production and helper activity was observed. In vitro addition of AS101 at 0.1 micrograms/ml to the in vivo UVB-treated lymphocytes raised IL-2 production to approximately double the initial level, and improved the helper activity of CD4 cells.

Adjuvants, Immunologic↗
PubMed1993

[Experimental study of the antibacterial activity of cloth impregnated with a disinfectant solution].

Disinfecting cloths were commercialized for several years. The solutions of disinfectant used are generally active in vitro in the conditions required by the french standards published by AFNOR, but it is also necessary to know the effectiveness of disinfecting cloths in conditions of use. We describe in this paper a method for this determination. Four bacterial stains recommended in the french standards were used: Staphylococcus aureus ATCC 9144, Enterococcus hirae ATCC 10541, Pseudomonas aeruginosa CIP A 22 and Escherichia coli ATCC 10536. The bacteria were layed on a test watch-glass and the disinfecting cloth was applied on it following the conditions recommended by the manufacturer. 15 minutes after using the disinfecting cloth, the bacteria on the watch-glass and those which were recovered on the disinfecting cloth during application were collected in a neutralising agent suitable for the disinfecting solution used and the surviving bacteria were counted. A similar test was performed using cloth impregnated with sterile distilled water. We studied the activity of unweaved cloths impregnated with a mixture of quaternary ammonium compounds (0.5%) and peroxides (0.1%). The results show that the method allows us to estimate the proper activity of the disinfectant used. In this study, a much higher decontamination of the watch-glass was observed with impregnated cloths than with cloths containing distilled water only. The mean reduction of the number of bacteria layed on the watch-glass was 5.95 log10 in 15 minutes in the first case and only 2.4 log10 in the second case. In addition, the disinfectant leads to the destruction of the bacteria recovered on the cloth during application.

Bedding and Linens↗
PubMed1976

[Hygienic and bacteriological comparative studies in 50 hospitals. IV. The bacterial contamination of fluids of intensiv care units, wards for premature children and new-born wards (author's transl)].

In intensive-care units and wards for prematures frequent use is made of medical apparatuses (such as oxygenators, nebulizers, respirators and incubators). These units are provided with a water reservoir which is utilized for the humidifications of the inspiratory air. They have become indispensable tools, especially in the treatment of seriously-ill patients. However, the water reservoirs of these devices have also frequently been found to harbour sometimes high concentrations of pathogens. With a view to clarifying the question as to the extent that liquids of different origin in the hospital area are contaminated with bacteria, 323 liquid samples were collected from intensive-care units, wards for premature and for newborn babies, and submitted for analysis. The senior nurse was questioned to obtain information about the measures of disinfection adopted in the respective wards. It was possible to cultivate pathogens from 22 per cent of the samples. P. aeruginosa accounted for 46 per cent, Enterobacter for 17.6% and E. coli for 12 per cent. A breakdown of the liquids by origin gives the following picture: 30 per cent of the liquids used for humidification of the inspiratory air (from respirators, inhalers etc.) were contaminated with pathogens. The analysis yielded a similar result in about 47 per cent of the cleaning water samples, in 10 per cent of the solutions in which clinical thermometers are kept and in 0 per cent of liquids from containers in which dressing forceps are kept. It emerged from inquiries that the lack of knowledge about the proper implementation of disinfection measures on the part of the nursing staff is still considerable. As a result, disinfectants of the quarternary ammonium compounds were used for the disinfection of medical apparatus in 37 per cent of all applications although their bactericidal action on gram-negative bacteria is limited. As regards the antimicrobial treatment of such parts as nebulizer chambers, connecting tubes, reservoirs of ultrasonic nebulizers, oxygen bottles and respiratory, parts with which the patient does not come into direct contact - the possibility of sterilizing them by autoclaving should be examined first. Not until this procedure has been ruled out on account of the thermolability of the materials used should another procedure such as keeping the materials in a disinfecting solution be adopted.

Bacteria↗
PubMed1993

Improved long-term stability of blood cocaine in evacuated collection tubes.

A study was undertaken to determine if a relatively minor modification of our existing specimen collection tubes could enhance the long-term stability of blood cocaine. We added cocaine, benzoylecgonine (BE) and ethanol to whole sheep blood in glass tubes that were prepared to contain one of several combinations of preservatives and anticoagulant. On day 1 and at intervals of up to one year, the drugs were measured by gas chromatography-mass spectrometry (cocaine and BE) or headspace gas chromatography (ethanol). Storage of blood containing 200 ng/mL cocaine at 4 degrees C for one year resulted in 100% loss of the drug using our normal 10 mL specimen collection tubes containing 100 mg sodium fluoride and 20 mg potassium oxalate. The substitution of oxalic acid for potassium oxalate reduced this loss to 76% without any significant effect on the benzoylecgonine or ethanol concentrations. Further addition of 10 mg echothiophate iodide, a quaternary ammonium compound, brought the cocaine loss down to 60% of the original concentration by one year. Further work will be required to determine if oxalic acid and/or echothiophate iodide could be used in blood collection vials intended for forensic toxicological purposes without any detrimental effect on other assays.

Animals↗
PubMed1993

Effects of chlorhexidine diacetate and cetylpyridinium chloride on whole cells and protoplasts of Saccharomyces cerevisiae.

Chlorhexidine diacetate (CHA) and the quaternary ammonium compound, cetylpyridinium chloride (CPC), were fungicidal to Saccharomyces cerevisiae A364A and CHA to its mannoprotein mutant LB6-5D. Both CHA and CPC induced leakage of K+ and pentose material from both strains and both agents induced protoplast lysis as well as interacting with crude cell sap. Differences were observed between CHA and CPC in protoplast lysis and in cell sap interaction. Q25 values for A364A with CHA as test agent were 5.6 and 1.6 (fungicidal activity, depending on method of calculation), 1.46 (cell sap interaction) and 0.77 (leakage of pentoses). A sub-lytic concentration of CHA reduced considerably protoplast regeneration. Although the plasma membrane is an important target site for both agents, interaction with other cellular components also contributes to fungal death.

Cetylpyridinium↗
PubMedDate not supplied

[Effect of arecoline on the structure of rest and active wakefulness in the catfish Ictalurus nebulosus].

The investigation demonstrated, that in the representative of the Osteichthyes--Ictalurus nebulosus, the hematoencephalic barrier for quaternary ammonium compounds is strongly pronounced. The difference in ability of tertiary and quaternary cholinergic substances to penetrate from the blood into the brain of this fish can be used for study of the presence and functional role of cholinoreceptive brain neurons. The pharmacological analysis showed the presence of cholinoreceptive neurons in the fish brain, participating in the activity of the functional systems which generate the "swimming automatism"--rhythmic movements of the tail, that are not accompanied by progression of the body. Apparently, this "swimming automatism" is the element of the future paradoxical sleep, which appears in its complete form in birds and mammals.

Animals↗
PubMed1997

[Allergy and preservatives. Apropos of 3 cases of allergy to benzalkonium chloride].

BACKGROUND: Ophthalmologists are not always aware of the hypersensitising potential of benzalkonium chloride (preservative widely used in ophthalmology). OBSERVATIONS: Hypersensitivity to benzalkonium chloride was asserted by allergologic exploration in the three cases reported. Contact allergy, a frequent phenomenon, was diagnosed in two cases. The third case represents one of the few cases described in ophthalmology of immediate hypersensitivity associated to vital risk: chemosis and angioneurotic edema is reported in a woman who had been already presented an anaphylactic shock to a quaternary ammonium family anaesthetic. DISCUSSION: The ocular allergologic evaluation is specified. Risk to benzalkonium chloride sensitisation factors (ophthalmology, presence of benzalkonium chloride in numerous daily used products) are reviewed. The risk of severe immediate allergy is increased due to the relationship of benzalkonium chloride to other quaternary ammonium compounds. CONCLUSION: Best risk prevention remains allergen eviction.

Adult↗
PubMed1997

[A new method of preparation of bovine colostral immunoglobulins for parenteral administration in calves].

A new simple method of preparation of bovine colostral immunoglobulins was described using a single step precipitation of skimmed bovine colostrum with dimethyllaurylbenzylammonium bromide (DMLBAB). This quaternary ammonium compound precipitated simultaneously nearly all colostral proteins lacking antibody activity. Bovine colostrum was collected mostly during of the first 24 hours after calving, at the latest however until 48 hours. Isolation of bovine colostral immunoglobulins proceeded as follows: one volume of skimmed colostrum containing 3-6% of immunoglobulins was slowly precipitated with the same volume of 2% water solution of DMLBAB at pH 7.9-8.1 along with continuous stirring. Turbid mixture was then heated to 43-45 degrees C and subsequently cooled to a room temperature standing overnight. Heavy precipitate sedimented down and supernatant fluid containing purified immunoglobulins was decanted and clarified by filtration. Residual DMLBAB occurring in the filtrate was removed by passage through a column of strongly acid catex, prepared in Na+ form. Purified colostral immunoglobulins were thickened to the required protein concentration by ultrafiltration. Dense retentate was clear and became an amber colour. Average yield of purified colostral immunoglobulins reached 18.8 g/litre of skimmed bovine colostrum (Tab. I). Electrophoretic purity of immunoglobulins fraction amounted to 90-95% (Fig. 1). For parenteral application in calves the above solution of immunoglobulins was subsequently adjusted to 9-11% content of protein, 0.9% of sodium chloride, pH 7.2, stabilized with 2% of aminoacetic acid and conserved with 0.015% of thiomersal. Finally, the preparation was sterilized by filtration, kept its content of immunoglobulins minimally 2 years at the temperature of storage between 2-8 degrees C and remained biologically harmless. Using the method described it was not necessary to remove casein from skimmed bovine colostrum prior to the purification of immunoglobulins. Hence the method provided a significant short cut especially in laboratory as well as pilot scale production of bovine colostral immunoglobulins bringing about a marked economic benefit.

Animals↗
PubMedDate not supplied

An in vitro investigation of the efficacy of CPC for use in toothbrush decontamination.

PURPOSE: A product designed as a toothbrush disinfectant containing cetylpyridinium chloride (CPC), a quaternary ammonium compound, recently was introduced. The purpose of this study was to provide additional evidence that CPC provides a practical solution for destroying residual microorganisms on air-dried toothbrushes and toothbrushes stored in a travel container. METHODS: Sterile synthetic toothbrushes were inoculated with optical density standardized laboratory cultures of Staphylococcus epidermidis or Candida albicans. Half were then disinfected with CPC and half were used as untreated controls. The toothbrushes were vortexed in sterile saline solution, diluted in a ten-fold series, and plated on 5% blood agar or Sabouraud dextrose agar. The plates were incubated at 37 degrees C in a normal atmosphere for 48 hours, and colonies were counted. RESULTS: CPC produced significant decreases in residual microorganisms. Using the CPC spray treatment on air-dried toothbrushes, Staphylococcus epidermidis essentially was reduced 100-fold, while Candida albicans had a 94% reduction of growth. Bacterial counts were higher in the samples stored in closed containers as compared to the air-dried samples. CONCLUSION: CPC appeared to be an effective toothbrush disinfectant for the organisms evaluated. It is practical and economical. CPC could easily fit into the recommendations of a practice committed to infection control.

Anti-Infective Agents, Local↗
PubMed1998

[Effect on the microbicidal efficacy of formaldehyde, glutardialdehyde, peracetic acid, chloramine T (N-chloro-4-toluenesulfonamide), m-cresol, ethanol and benzyldimethyldodecacylammonium bromide by blood (model experiments for chemical disinfection of instruments)].

In a preceding paper (Zbl. Hyg. 191 [1991] 457-477) we reported on the dependence of the microbicidal efficacy of active agents of the disinfection of instruments on the amount of coagulated blood adhering to the instruments. In the present investigation, we were interested in the dependence of the microbicidal effects on the amount of blood in the solutions of the active agents. Test areas of 2 cm2 were contaminated with 50 and 100 microliters coagulating blood, respectively, containing cells of Staphylococcus aureus as test germ. The solutions of the microbicidal agents were contaminated with heparinized blood up to a concentration of 4% immediately before starting the disinfection and 24 hours before, respectively. After a period of action lasting 1 hour at 20 degrees C, the relative number of test germs capable of multiplying (N/N0) was determined. The concentration of the microbicidal substances reducing the relative number of test germs capable to multiply to 10(-4) served for estimating the dependence of the microbicidal efficacy of the agents on the blood content of the solutions. The experimental results depended on the thickness of the layer of coagulated blood. The dependence of the efficacy of the microbicidal substances on the blood content of the solutions was the higher the thinner the blood layer was. At a thickness of the layer of the coagulated blood of 0.25 mm, a blood content of the solution of 4%, and applying it immediately after adding the blood, the concentration of glutardialdehyde had to be 1.6 times that without blood to reach the same microbicidal efficacy. When applying the solution 24 hours after adding the blood, the concentration of glutardialdehyde had to be 4.2 times that without blood. The quaternary ammonium compound reacted faster with the blood than did glutardialdehyde; the respective factors were 2.6 and 4.5. The concentration factors of chloramine T were 3.3 and 3.8. Under the conditions of the test, peracetic acid exhibited small concentration factors: 1.3 and 1.6. The microbicidal efficacy of ethanol, formaldehyde and m-cresol soap solution was not or only slightly altered by the amount of blood in the solution of the microbicidal agent.

Benzalkonium Compounds↗
PubMed1998

Influence of several adjuvants on the immune response against a recombinant meningococcal high molecular weight antigen.

Studying outer membrane proteins as vaccine candidates, our group has previously isolated, cloned, and expressed in Escherichia coli the gene encoding for a high molecular weight protein (P64k), common to many meningococcal strains. To continue the characterisation of this meningococcal antigen, we have evaluated its immunogenicity in mice alone or combined with several commercially-available adjuvants. We used as an adjuvant aluminium hydroxide (Alhydrogel and Rehydragel), aluminium phosphate, Algammulin, crude saponin, the saponin Quil A, dimethyl-dioctadecyl ammonium bromide (DDA), Freund's adjuvant, and Montanide 888. The antibody titres against the recombinant protein and whole meningococci elicited with these adjuvants were compared. We found that Quil A produced the highest titres against the recombinant P64k. Algammulin and the quaternary ammonium compound DDA induced the highest levels of antibodies against meningococci. We analysed the recognition of a set of linear peptides by antisera prepared against the protein combined with some of the adjuvants. The responses depended on the adjuvant used and the results have been confirmed by epitope mapping using overlapping peptides synthesised on pins.

Adjuvants, Immunologic↗