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Biomedical subjects

K Botzenhart

Publications and source records attributed to K Botzenhart.

At least 73 records · Page 4Linked to original sources
PubMed1985

[Determination of the killing rate of Bacillus spores by peracetic acid].

The sporocidal properties of peracetic acid (PAA) at defined concentrations were characterized by determination of decrease in PAA after addition of D-glucose, human albumin and suspensions of spores; concentration of PAA, which inactivates 10(6)-10(7) spores of Bacillus cereus, B. subtilis, B. megaterium and B. licheniformis within 10-30 min; inactivation constant k, decimal reduction time D and the sporocidal index (mg PAA X min X ml-1) at that concentration. In contrast to albumin, the spore suspension caused relatively little reduction of PAA concentration (less than 5% at the concentrations used). B. cereus, B. subtilis and B. megaterium had similar inactivation rates with k-values in the range of 0.368 and 0.541 min-1, D-values between 4.26 min and 6.26 min at 0.2 mg/ml PAA. B. lichenformis was much more resistant showing a k = 0.345 min-1 and D = 6.66 min at 3.0 mg/ml PAA. The sporocidal index of B. lichenformis was 180 mg X min X ml-1 while the three other species had sporocidal index-values of 7 mg X min X ml-1.

Acetates↗
PubMed1984

In vivo activity of proteases of Pseudomonas aeruginosa in a rat model.

The granuloma pouch technique was used to study the in vivo characteristics of four strains of Pseudomonas aeruginosa that differed in levels of alkaline protease and elastase production. Bacterial counts, alkaline protease and elastase concentrations, and IgG levels of pouch exudates were determined quantitatively; total protein levels were determined semiquantitatively. In vivo protease concentrations were in the nanogram range; during the investigated period individual strains either increased enzyme production or remained negative. In vitro alkaline protease:elastase ratios correlated with in vivo ratios in three of the four strains. Proteolytic strains caused a decrease in IgG and alpha 2-fraction proteins. Purified rat IgG was cleaved rapidly by elastase and slowly by alkaline protease; both cleaved IgG at the hinge region. The study determines the concentration of P aeruginosa alkaline protease and elastase after infection in a rat model, shows cleavage of rat IgG and other proteins due to alkaline protease and elastase, and suggests that enzymes other than proteases are involved in the pathogenesis of P aeruginosa infections.

Animals↗
PubMed1984

Detection of proteases of Pseudomonas aeruginosa in immune complexes isolated from sputum of cystic fibrosis patients.

Sera and sputa of 12 cystic fibrosis patients suffering from chronic Pseudomonas aeruginosa lung infections were assayed for immune complexes using the Raji cell assay. Whereas all sera were negative, 33% of the sputa were positive for immune complexes. Sera and sputa of these patients were also assayed for antibodies against P.aeruginosa alkaline protease (AP) and elastase (Ela) and sputa for AP and Ela, using radioimmunoassays. All patients revealed antibody titers to the proteases in serum (1:5-1:1000) and eight patients had antibody titers to the proteases in sputum (1:5-1:100); all sputa were negative for AP and Ela. Sputum immune complexes and IgG were separated from whole sputum on a Protein A-Sepharose C1-4B column and treated with 0.75 M 2-mercaptoethanol and iodoacetamide after elution. After treatment, 58% of the sputa were positive for AP and/or Ela (5-200 ng/ml sputum). The present study shows that proteases of P.aeruginosa are bound in immune complexes after the initiation of the immune response to these antigens and it yields new insights into the role of these proteases in chronic lung infection in cystic fibrosis.

Antigen-Antibody Complex↗
PubMed1984

[Residues of disinfectants in hospital sewage].

All of 67 samples of sewage, taken at different points from the sewers of the Bonn University hospitals, contained phenolic substances in concentrations ranging from 0.09 mg/l to 5.05 mg/l. About 0.15 mg/l might be caused by human excretion of phenolics. Six samples contained free formaldehyde (2.72-28.38 mg/l), five samples chlorine (0.1 to 1 mg/l). In the main sewer of the hospitals the substances were diluted, but a measurable concentration reached the communities sewage lines. There were no characteristic diurnal changes of the concentrations. Measurements of biological oxygen demand (BOD) in native and artificially prepared sewages using o Sapromat showed, that pure phenol, o-phenylphenol, chlorine and formaldehyde in concentrations as found do not reduce the biologic decomposition. With the exception of chlorine, the substances seem to be integrated into the aerobic microbial decomposition. 3,4 chlorcresol, instead, is able to retard the begin and reduce the amount of decomposition in concentrations, which were found as maximal concentrations for phenolic substances in the sewage samples. Two of 67 samples with the highest concentrations of disinfectants revealed measurable toxity in form of a BOD reduction. The other samples, instead, showed a faster microbiological decomposition than comparable artificial sewage.

Bacteria↗
PubMed1983

[UV irradiation of the peritoneal dialysis solution for the prevention of peritonitis].

Micro-organisms causing peritonitis during peritoneal dialysis or CAPD can reach the peritoneal cavity either along the Tenckhoff-catheter or via contaminated dialysis fluid. Laboratory experiments with UV irradiation of artificially contaminated CAPD fluid were made to demonstrate whether decontamination could be achieved during the flow through a UV-penetrable (lambda 2537 A) section of the CAPD catheter. Five CAPD bags were contaminated with a fluid culture of the following micro-organisms which frequently cause peritonitis (S. epidermidis, S. aureus, P. aeruginosa, E. coli, and Candida albicans). After UV irradiation positive cultures could not be demonstrated. UV irradiation of the peritoneal dialysis fluid before entering the peritoneal cavity is proposed as an additional preventive measure.

Candida albicans↗
PubMed1983

Proteases of Pseudomonas aeruginosa in patients with cystic fibrosis.

Radioimmunoassays were used to determine titers of antibody to alkaline protease (AP) and elastase (Ela) produced by Pseudomonas aeruginosa in sera and bronchial secretions, in vitro production of AP and Ela by P. aeruginosa isolates, and occurrence of these enzymes in bronchial secretions from patients with cystic fibrosis. Titers of serum antibodies to AP ranging from 1:10 to 1:545 and to Ela ranging from 1:10 to 1:725 were found in 83%-88% of patients with cystic fibrosis and chronic lung infections due to P. aeruginosa. Antibody titers in liquified bronchial secretions were approximately 10% of the serum titers. Thirty-one (93%) of 34 isolates produced both proteases in vitro in comparable amounts (concentration of protease in culture supernatant: AP, 0.01-480 micrograms/ml; Ela, 0.02-490 micrograms/ml). AP and Ela were detected in vivo when antibodies to the enzymes were absent. The results suggest that specific immune responses in patients with cystic fibrosis neutralize proteases of P. aeruginosa.

Adolescent↗
PubMed1983

[Effects of photochemical smog from a flow reactor on bacteria. I. Determination of the effects of photochemical smog on bacteria].

To measure the damage to bacteria from photochemical smog Serratia marcescens, Staphylococcus epidermidis, Micrococcus luteus and spores of Bacillus cereus have been exposed to defined gas-mixtures. A smog-simulation-chamber has been used which allowed adjustment of reproducible and longterm constant smog formations due to the flow system. Two methods have been applied to examine the bactericidal effects of the photo-chemical smog: adsorption of bacteria to membrane filters and spraying on silk threads. Smog mixtures formed by olefines (propene 4200 ppb, isobutene 3000 ppb, trans-2-butene 1600 ppb) and nitrogene oxides (500-700 ppb) showed bactericidal effects at ozone levels of 500 ppb. The survival of exposed bacteria is influenced less by gasing with 500 ppb ozone than with the smog mixture.

Air Microbiology↗
PubMed1983

[Effects of photochemical smog from a flow reactor on bacteria. II. Determination of bactericidal components in photochemical smog].

The mixture of substances in the photochemical smog could be detected by different reduction rates of exposed bacteria. Beside ozone other products of the ozone/olefine-reaction could reduce the survival of exposed bacteria. For Staph. epidermidis a toxic influence from the reaction products could be found only after UV-irradiation. The main components were aldehydes, hydrocarbons, radicals, peroxiradicals and radicaloxides. For peroxiacetylnitrate (PAN) no bactericidal effect could be found for bacteria adsorbed on membrane filters in concentrations of 300 ppb in the smog (UV-irradiation was put off for two hours) and even in concentrations of 1000 ppb prepared by gaschromatography. The influence on lipopolysaccharide (lps) defective mutants of Salmonella minnesota showed the protection of the lps-layer against e.g. relative humidity and ozone (500 ppb), but no specific protection against smog components.

Air Microbiology↗
PubMed1982

Extracellular toxins of Pseudomonas aeruginosa. III. Radioimmunoassay for detection of alkaline protease.

A sensitive and specific solid phase radioimmunoassay (RIA) for detection of the alkaline protease (AP) of Pseudomonas aeruginosa (PA) was developed and the RIA was used to assay 10 PA strains of various origin and serotype. A great strain variability of AP production was found which differed from 180 to 0.1 microgram per ml of culture supernatant fluid (CSF). The AP concentrations were compared to the total proteolytic activity of the CSF and the results were discussed in relation to cystic fibrosis patients suffering from chronical PA lung infections.

Hydrogen-Ion Concentration↗
PubMed1981

[Extracellular toxins of Pseudomonas aeruginosa. I. Purification and characterization of two exoproteases (author's transl)].

Alkaline protease (protease I) and a protease with elastase activity (protease II) were isolated from two different strains of Pseudomonas aeruginosa (PA). Proteolytic activity was measured during the early exponential phase of growth and was highest when cultures reached the stationary growth phase. The extracellular character of protease I and II was demonstrated by measuring the intra- and extracellular ATP-concentration. Purification was achieved by precipitation with 65% ammonium sulfate, precipitation with 70% acetone, gelfiltration on Sephadex G-100 and chromatography on DEAE-Sephacel. The purified proteases were characterized. The pH for optimal proteolytic activity of protease I was at pH 9--10, for protease II at pH 8--9. Both enzymes cleaved casein and gelatine, in addition protein II elastin. Enzymatic activity of protease II was inhibited by 10(-3) M EDTA at pH 8.1 to 82%. Inactivation of protease I was not achieved by 10(-2) M EDTA. Molecular weight of protease I was estimated at 57,000, molecular weight of protease II at 39,000. Both enzymes consist of one polypeptide chain. In isoelectric focusing the protease I was separated into two components with pH values of 8.5 and 8.7, while protease II had isoelectric points of pH 6.0 and 6.4. Further characterization of protease I was done with amino acid analysis. Protease I was fairly stable over a pH range of 6--9 at room temperature. The optimal temperature for proteolytic activity was 60 degrees C. The results are discussed in view of proteases of other PA-strains.

Amino Acids↗
PubMed1981

[Extracellular toxins of Pseudomonas aeruginosa. II. Effect of two proteases on human immunoglobulins IgG, IgA and secretory IgA (author's transl)].

Two proteolytic enzymes of Pseudomonas aeruginosa--an alkaline protease and an elastase--were incubated with human myeloma proteins IgG and IgA as well as with secretory IgA at 37 degrees C. Digest mixtures were analyzed after 1, 5, 12, 24, 48 and 72 h by SDS-polyacrylamide gel electrophoresis after reduction by 2-mercaptoethanol. Under conditions which resulted in cleavage of all three immunoglobulins by the elastase in the hinge-region, the alkaline protease cleaved only IgA. It was suggested that proteases of PA interfere with the immune-system of the host by cleavage of immunoglobulins. Elastase-positive PA strains should be more virulent compared with PA strains which produce only alkaline protease or are protease-negative at all.

Exopeptidases↗
PubMed1981

[Hygienic quality of lakes which are used as open-air bath. 2. Communication: Comparison of biochemical typed Escherichia coli strains isolated from lake water and bird excrements (author's transl)].

368 strains of Escherichia coli were isolated from lakewaters and bird excrements (mainly black-headed gulls) using mandatory methods for drinking water examination. All strains were further characterized by 43 biochemical physiological and 30 morphological features. Besides the API 30 E Enterobacteriaceae system and the Roche Enterotube system of biochemical testing were used comparatively. The analysis using numerical methods for taxonomy pointed out that a single biotop could be characterized by the small physiological variation of the strains.

Animals↗
PubMed1980

[Antibacterial substances in tamponades after tympanoplasties - an "in-vitro"-study (author's transl)].

This "in-vitro"-study is concerned with the efficiency of antibacterial agents used in packings after tympanoplasties. For this purpose, gel-foam-material was impregnated either with rolitetracyclin (mostly used in German ENT-clinics), or comparatively with a combination of bacitracin and neomycin or with antiseptics like phenylmercuriborate and povidon-iodine. It is tested, how these impregnated "packings" behave in the presence of pathogenic germs (Staph. aureus, Ps. aeruginosa). Antibacterial effects and alterations of the material were judged. It is shown, that in some regards the rolitetracyclin - very successful in clinical use - is superior to the other substances tested.

Anti-Bacterial Agents↗
PubMed1980

[Hygienic quality of lakes which are used as open-air bath. I. Communication: seasonal variation of total colony count, the number of Escherichia coli and coliforms (author's transl)].

Four lakes situated in the recultivated area of the Rhenish brown-coal district were examined bacteriologically during a period of one year. Total colony count and the number of Escherichia coli and coliforms were determined and compared with the influence of meteorological factors and human and animal impacts.

Animals↗
PubMed1979

[Studies to investigate the ecological importance of the mass development of Hydrodicyton reticulatum in infiltration basins for drinking water. II. Localization of the active components with the aid of thin-layer chromatography and bioassay detection (author's transl)].

Thin-layer chromatogramms made from ethanol extracts of the green fresh-water alga H. reticulatum were tested by bioassay detection against several strains of Bac. subtilis. The chromatogramms were overlayed with agar, seeded with the test strains. The production of two growth-inhibiting zones could be demonstrated (Fig. 1). One of them seems to be correlated with chlorophyll derivatives. The second zone--larger than the first one--was formed by a fatty acid fraction which was more active in cells harvested in 1973, than in those harvested in 1974. Only a very small cell free zone was found in bioassays of water extracts of H74, presumably caused by chlorophyll derivatives, but there was an area of weak inhibition in H73 as well as in H74.

Bacillus subtilis↗