PubMed Health⌕ Search

Biomedical subjects

R Machmerth

Publications and source records attributed to R Machmerth.

14 recordsLinked to original sources
PubMed1990

[Thermal sterilization in the revision of the sterilization section of the East German medical reference].

The G-value estimating sterilization-process is offered and compared with other scales selected from bibliography. Based on the kinetic of destruction of microorganisms the G-value considers every parts of sterilization-processes especially with reference to peak-sterilization. It takes into account the resistance of microorganisms, the safety index and also the influence of germ reducing measures, e.g. cleaning, before the sterilization-processes. Finally a formula is presented to transform G- and F-values each other.

Bacterial Physiological Phenomena↗
PubMed1986

[Kinetics of germ killing and damage to selected bacterial enzymes by thermal and chemical influences. I. Theoretical background of killing and enzyme inhibition kinetics].

Thermal and chemical influences on microorganisms and the kinetics of microbicidal processes are described in terms suitable to define the resistance of microbes to heat and disinfectants resp. sterilisants. Interactions between active substances (e.g. disinfectants) and enzymes are formulated in equations, and the parameters of kinetics of inactivating enzymes (e.g. Ki-values) are derived. They permit a gradual evaluation of efficacy of microbicidal agents irrespective of their concentration.

Bacteria↗
PubMed1986

[Kinetics of germ killing and damage to selected bacterial enzymes by thermal and chemical influences. II. The thermoresistance of Bacillus subtilis compared to the thermostability of enzymes of this species].

The influence of moist heat on the recultivation of Bacillus subtilis-spores and on the thermal inactivation of two enzymes prepared from this species was investigated. The velocity constant k of destroying microorganisms (determination by counts of B. subtilis-spores with microbiological methods) and the specific activity (determination by biochemical methods) of creatine kinase (EC 2.7.3.2.) and aminopeptidase (EC 3.4.11.2.) were compared. A significant correlation between the logarithm of specific activity and the velocity constant (k/2,303 = 1/D) was found. A thermal exposition for 15 min and 105 degrees C was sufficient for the total inhibition of the activity of creatine kinase and aminopeptidase in the intact spores of B. subtilis.

Aminopeptidases↗
PubMed1986

[Kinetics of germ killing and damage to selected bacterial enzymes by thermal and chemical influences. III. Damage to enzymes from Bacillus subtilis by disinfectants compared to bacterial count reduction].

In the present paper a trial is reported to determine the efficacy of disinfectants by common bacteriological means as well as by biochemical methods. The results are compared, and they reveal a remarkable correlation (r = -0.9476) between the velocity constants of disinfection (1/kw) and the lg 1/Ki(app). The Ki(app)-value is the inhibition constant for the competitive inhibition of the creatine kinase reaction from Bacillus subtilis by disinfectants. The practical impacts are discussed.

Bacillus subtilis↗
PubMed1976

[Biological and chemical indicators of thermal sterilization and their possible effect on its general concept].

Regarding to ignorance of germ thermoresistance occurring in hospital environment, the effect of sterilization in medicine is determined occasionally on samples of medium with high number of germs or tests are performed to determine the sterilization success (in pharmacy) by examining samples of sterile badges, although their degrees of contamination (mostly low) before sterilization are not known. Instead of fixed sterilization parameters, the new second Pharmacopoeia of the German Democratic Republic (1976 seqq.) allows a free choise of sterilization parameters ingeniously spaced (110 degrees C--140 degrees C vapour, 160 degrees C--200 degrees C hot air) according to diagrams. The mentioned methods both imperfect and expensive ones should be replaced by introducing sterilization indicators whose changes might render the designation "sterile" possible. Substantial differencies between biological and chemical indicators are shown.

Chromium↗
PubMed1976

[Biological and chemical indicators of thermal sterilization and their possible influence on its total conception].

Regarding to ignorance of germ thermoresistance occurring in hospotal environment, the effect of sterilization in medicine is determined occasionally on samples of medium with high number of germs or tests are performed to determine the sterilization success (in pharmacy) by examining samples of sterile badges, although their degrees of contamination (mostly low) before sterilization are not known. Instead of fixed sterilization parameters, the new second Pharmacopoeia of the German Democratic Republic (1976 seqq.) allows a free choise of sterilization parameters ingeniously spaced (110 degrees C--140 degrees C vapour, 160 degrees C--200 degrees C hot air) according to diagrams. The mentioned methods both imperfect and expensive ones should be replaced by introducing sterilization indicators whose changes might render the designation "sterile" possible. Substantial differencies between biological and chemical indicators are shown.

Cross Infection↗