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Biomedical subjects

W Weuffen

Publications and source records attributed to W Weuffen.

At least 37 records · Page 2Linked to original sources
PubMed1983

[The contribution of Robert Koch to the founding of the doctrine of disinfection and present priorities in disinfection research and practice].

Robert Kochs studies on disinfection are distinguished by well defined, clear experimental arrangement and commitment to practice. He investigated the effectiveness of disinfection by following recultivation tests in vitro and in animal experiments. He examined chemical substances of different origin, the action of hot air and superheated steam with a spectrum of microorganisms, including bacterial spores. Priorities of the recent development in disinfection are among other things the application of steam disinfectors and of chemical disinfectants in the gas-phase e.g. for disinfection of tubes, the use of combinations of tensides with disinfectants, of disinfectants effective against spores of clostridium and against hepatitis viruses, of disinfectants with low corrosiveness and low toxicity against men and domestic animals. Disinfection is a component of a system of measures in antimicrobial regimes and in protective systems.

Animals↗
PubMed1982

[Subacute and subchronic percutaneous tolerance testing (28-day and 90-day test) of epicutaneously applied dis-infectants as demonstrated by the example of peroxyethanoic acid (author's transl)].

As compared to control animals, guinea-pigs to the shaved backs of which a dose of 0.16 ml of a 0.12% solution of PES/100g. of body mass had been applied twice daily for periods of 28 and 90 d, respectively (5 d of application being followed by 2 d without treatment), showed erythema, loss of hair, slower increase in mass, increased heart rate, smaller body mass/kidney mass and body mass/spleen mass ratios, increases in leucocytes, ASAT, ALAT, LDH I and LDH III. In the 28-d test, slight inflammatory symptoms of the liver, kidneys and heart were observed in the experimental animals. These symptoms were more marked in the 90-d test, granulomata in the livers being particularly striking. A pneumonia of moderate to very marked degree is suggestive of the activation of a clinically latent PES infect whereby the inflammatory alterations in the kidneys might be explained by the formation of metastases.

Acetates↗
PubMed1982

[2-Chloro-6-methyl-4-benzylphenol (CMB), a potential antimicrobial agent Part 1: Microbiostatic Efficiency (author's transl)].

The antimicrobial agent 2-chloro-6-methyl-4-benzylphenol (CMB) can be made from a by-product of herbicide synthesis. CMB is of good to very good effectiveness against dermatophytes and yeast-like moulds and also against Gram-positive cocci. Its activity against Gram-negative rod-shaped bacilli is poor, but the contemplated concentration of 1% will be sufficient for practical purpose. A comparison with commercially available antimicrobial agents gives the impression that its closer examination will be promising. Possibilities of application studies aiming at discovering convenient fields of application are indicated.

Ascaris↗
PubMed1982

[Comparative studies on the determination of thiocyanate in biological materials (author's transl)].

On verifying methods for the determination of thiocyanate in biological materials, we started from the technique as described by Boxer and Rickards [5]. In different methods, the accuracy of the data obtained is affected by the deproteinization process or interfered with iron (III) ions or pyridine/benzidine, the deproteinization process being the decisive factor. This holds true especially in respect of interfering factors that remain in the supernatant (low-molecular amino compounds) and in respect of the coprecipitation of thiocyanate, the nature of the respective biological material playing an important part in both cases. At higher thiocyanate concentrations, pretreatment with a denaturing agent that is commonly used to deproteinization of human and bovine sera involves a small loss of thiocyanate due to coprecipitation. In case of high demands on reproducibility and accuracy of the analytical results, and in case of special analytical problems, isolation of thiocyanate is absolutely necessary (chromatography on Sephadex, aeration after conversion to hydrogen cyanide). Gas chromatography is suited for determining thiocyanate in whole blood.

Amino Acids↗
PubMed1982

[Studies on the effect of low concentrations of thiocyanate on the protein human serum albumin].

By means of fluorescence and absorption measurements the authors studied the interaction of the protein human serum albumin with relatively low concentrations (up to 5 mmol/l at the most) of thiocyanate ions. Such concentrations lead to a slight quenching of the tryptophan fluorescence in human serum albumin. The effect of thiocyanate is not due to an overall action on the protein (as sometimes observed with higher thiocyanate concentrations), but to a local interaction of the fluorophore tryptophan with the neighbouring anion-binding site which is occupied by thiocyanate.

Binding Sites↗
PubMed1982

[Use of paraformaldehyde tablets for bacterial count reduction, disinfection, cold sterilization, and sterile preservation of medical instruments. 3: On the use of paraformaldehyde tablets in medical institutions].

Paraformaldehyde tablets are very effective against a wide spectrum of organisms. They may be recommended for targeted degerming measures in medical practice. Their utilization requires the observance of the conditions necessary for their efficient use. The tablets should be employed only in containers which are as tight-fitting as possible (preferentially instrument cabinets, Heynemann cabinets, catheter boxes and plastic bags). Paraformaldehyde tablets are well suited for the reduction of the bacterial population and the storage of nonwrapped sterilized instruments. For this purpose, 1 tablet/dm3 is needed. The exposure time required for bacterial count reduction is no less than 3 h. Despite certain limitations, paraformaldehyde tablets may be used for disinfecting. The objects to be disinfected should be neither too contaminated nor too soiled. The minimum period of exposure is 5 h, and 10 tablets/dm3 are necessary. Cold sterilization requires 10 tablets/dm3, too; but the exposure time ranges from 15 to 24 h. This method (which must be considered an expedient) should be employed only if the respective device or instrument cannot be sterilized by other sterilizing techniques. In any case, 80% relative air humidity is a must in the devices in which paraformaldehyde tablets are used.

Bacteria↗
PubMed1981

[Studies on influence of thiocyanate on immune response by use of the hemolytic plaque technique (author's transl)].

Mice immunized with sheep red blood cells produce more direct plaque-forming cells, estimated with the hemolytic plaque-technique, during the primary immune response if they receive in that time 150 mg NaSCN/kg body mass with the drinking-water every day. The thiocyanate quantity of serum in immunized animals is higher than that in non-immunized animals. The titers of antibodies estimated by the hemagglutination test is about 1 titer step higher in thiocyanate-treated animals than in non-thiocyanate-treated animals. That applies also to the secondary immune response, in which course thiocyanate was not supplied. It is possible, that for instance a greater number of memory-cells was produced during the primary immune response in consequence of the thiocyanate application. Studies in similar arrangement with guinea-pigs confirm these statements in certain parameters.

Animals↗
PubMed1981

[Gas chromatographic determination of thiocyanate in vegetable and animal foods and in human serum following paper chromatographic separation (author's transl)].

Paper chromatographic separation of thiocyanate is the first step in determining non-bound thiocyanate in homogenized animal and vegetable foods and in human serum. The thiocyanate eluated from the paper chromatogram is brominated and then determined as cyanogen bromide using a gas chromatograph equipped with an electron-capture detector. Interfering substances (mainly ethanol-unprecipitable protein components, amino acids and cyanide from glycosidic precursors) are eliminated by this procedure.

Chromatography, Paper↗
PubMed1980

Definition, prophylactic value and toxic hazard in the use of antiseptics.

Antiseptics are mainly microbiostatic, relatively insoluble compounds, with little ability to penetrate into the skin or the mucous membranes. They can be used prophylactically or therapeutically on various areas of the body surface (skin and the mucous membranes, e.g., of mouth, intestinal-, respiratory-, and urogenital tract). If used in this way, they do not generally cause toxic effects, though sensitization to safe antiseptics may occur. The use of chemotherapeutic agents as antiseptics should be avoided wherever possible, because of the risk of emergence of resistant bacteria; but it would be clearly indicated if this were the only way to save a patient's life. Resistance to antiseptics is less likely to emerge than to antibiotics.

Anti-Infective Agents, Local↗
PubMed1980

[Studies on the relationship between 2-iminothiazolidine-4-carboxylic acid and the thiocyanate metabolism in the guinea-pig (author's transl)].

In vitro and in vivo experiments have been carried out to elucidate the metabolism of 2-iminothiazolidine-4-carboxylic acid (ITC). By using 35S-ITC, the formation of 35SCN as well as of 35S-containing ITC metabolites could be excluded. As compared to the findings from control animals, the serum thiocyanate levels determined in guinea-pigs after oral administration of ITC were unchanged.

Animals↗
PubMed1980

[Use of a modified Aldridge method for the elimination of certain amino acids and protein components interfering with the determination of thiocyanate in human and animal sera (author's transl)].

Since the amino acids and protein components remaining in the supernatant after protein precipitation react with bromine to give cyanogen bromide just as thiocyanate, they interfere with the determination of human and animal sera by the Aldridge method. This interference is widely eliminated by hydrochlorination of the amino acids or by reduction of the redox potential of bromine in an acid medium.

Amino Acids↗
PubMed1979

[On the influence of thiocyanates on the delayed immune response in intact and epinephrectomised guinea pigs (author's transl)].

Daily application of 32 mg/kg sodium thiocynate from 1--11th respectively 12th--21st experimental day causes in epinephrectomised guinea pigs at the 26th experimental day an inhibition of cell-mediated immune response (sensitization was induced by intraperitoneal injection of horse serum at the 5th and 7th experimental day). The inhibition of cell-mediated immune response could be demonstrated by means of migration inhibition of spleen cells. Epinephrectomy was performed by operation procedures twice a week. Gluco- and mineralocorticoids were applied supplementary. -- Also other proved thiocyanates respectively compounds with thiocyanate groups such as potassium thiocyanate, ammonium thiocyanate and d,1-2-imino-3.4-dimethyl-5-phenyl-thiacolidinhydrothiocyanate showed the same effect. The results are only pointed out in intact animals, but distinct in epinephrectomised guinea pigs. Finally a significant weaker effect, but of the same kind was observed by potassium- and sodium iodate. Every used dose of prednisolone and cyclophosphamide suppress the migration inhibition. The influence of 2-iminothiacolidin-4-carbon acid and desoxycorticosteronacetat on the migration inhibition is different and depends on the antigen dose applied for sensitization. -- Simulated daily injections undertaken in form of stitches and application of aqua destillata are inefficacious.

Adrenal Glands↗