PubMed Health⌕ Search

Biomedical subjects

L A Abramova

Publications and source records attributed to L A Abramova.

8 recordsLinked to original sources
PubMed1990

[An outbreak of ornithosis at a textile factory].

For the first time an outbreak of ornithosis at a textile factory is described. The data on the specific epidemiological features of the outbreak, the specific clinical features of the disease, the results of catamnestic observations and the study of the titers of specific antibodies in the complement fixation test are presented.

Adolescent↗
PubMed1978

[Enzymatic inactivation of levomycetin and penicillin by cells of the plague and pseudotuberculosis microbes that contain R plasmid depending on cultivation conditions].

The activity of enzymes, inactivating levomycetin and penicillin in the cells of plague and pseudotuberculosis microbes bearing extrachromosomal determinants resistant to a number of antibiotics was studied as dependent on some cultivation parameters: population age, aeration rate and temperature. It was shown that the highest capacity for levomycetin acetylation was characteristic of the cells in the late logarithmic and early stationary growth phages. Accumulation of levomycetin O-acetothers in the incubation medium markedly increased, when the cells were grown under the conditions of intensive aeration. An increase in the cultivation temperature up to 37 degrees C was accompanied by a reliable decrease in the activity of levomycetin acetylase in the transconjugant plague and pseudotuberculosis microbes though no correlation with the resistance levels in the same strains to the above antibiotics was observed. Optimal conditions for penicillinase production were determined. The maximum levels of penicillinase were found in the cells of Y. pestis 556/106 Rn with the episotic resistance type in the early exponential developmental phase under the aeration conditions and the temperature of 28 degrees C.

Acetylation↗
PubMed1975

[Study of the mechanisms of levomycetin inactivation by the palgue causative agent and Escherichia coli with episomal and chromosomal resistance. The enzymatic acetylation of levomycetin].

One of the mechanisms of levomycetin inactivation, i.e. enzymatic acetylation of the plague causative agent and Coli bacteria with chromosomic and episomic type of resistance was studied. It was shown that resistance to levomycetin in the recombinants of the plague microbe and Coli bacteria stipulated by one and the same R-factor was associated with their capacity for the antibiotic inactivation mainly with the help of levomycetinacetyltransferase. At the same time the enzyme activity in the mutants was very low and in the cells of Y. pestis and E. coli sensitive to the antibiotic it was absent. Levomycetinacetyltransferase is to somee extent soluble, still a singificant amount of it is connected with the structures of the bacterial cells and in particular with the cytoplasmic membranes. Comparison of the activity of levomycetinacetyltransferase as dependent on the incubation time, substrate concentration, pH and thermal treatment provided determination of quantitative differences in the properties of the enzyme of Y. petis and E. coli with episomic multiple drug resistance. However, under the experimental conditions transfer of R-factor from one host to the other induced no qualitative changes in the mechanism of levomycetin inactivation.

Acetylation↗
PubMedDate not supplied

[The isolation and characteristics of Yersinia pestis membranes].

A method for fractionation of membrane structures of Yersinia pestis is developed. It involves the following basic stages: the cultivation of bacteria in a liquid nutrient medium, mechanical destruction from the solid state in the X-press or ultrasound treatment of the suspension, subsequent two-stage centrifugation in the step (70-15%) and linear (70-45%) gradients of the sucrose density, collection of fractions and their storage. The method makes it possible to separate rapidly and efficiently the outer and cytoplasmic membranes which preserve biochemical and morphological integrity. This is confirmed by the distribution pattern of marker enzyme activities, by the electron microscopic control as well as by other modern sediment tests. High heterogeneity of the polypeptide composition of the isolated membrane preparations has been shown by electrophoresis in PAAG in the presence of sodium dodecyl sulphate as well as definite sensitivity of certain protein subunits to variations of the temperature (28 or 37 degrees C) during cultivation of a plague agent.

Bacteriological Techniques↗
PubMedDate not supplied

[Sublimation-dried mare's milk and the possibility of its use in creating infant and dietary food products].

The main biological parameters were studied in sublimated mare's milk: protein fraction composition, amino-acid spectrum, fatty-acid composition of lipids and the content of vitamins and mineral substances. A high biological value of the sublimated mare's milk has been proved, as well as significant proximity of its composition to human milk. Preliminary data have evidenced expediency of mare's milk use for the development of adapted milk mixtures for baby foods. However, the fatty component of the mixtures needs certain correction by addition of vegetable oil. The sublimated mare's milk can be used for the production of kumiss, that would extend its application in dietotherapy by removing season and territory limitations.

Animals↗