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Biomedical subjects

V G Kuznetsov

Publications and source records attributed to V G Kuznetsov.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

[DNA, RNA, and protein biosynthesis in cells of Yersinia pseudotuberculosis at various cultivation temperatures].

Y. pseudotuberculosis cells cultivated at temperatures of 37 degrees C and 8 degrees C were found to be capable of incorporating exogenic precursors into DNA, RNA and protein. The linear growth of thymidine incorporation occurred during 8 hours of cultivation at 37 degrees C, then the amount of the incorporated label decreased. At 8 degrees C the level of thymidine incorporation into DNA gradually increased for 80 hours and longer, but not reaching the level of incorporation observed at 37 degrees C. The incorporation of uridine into RNA of Y. pseudotuberculosis cells reached its maximum after 4 hours of cultivation at 37 degrees C, at a lower temperature of cultivation the incorporation of uridine into bacterial cells was almost linear, though slower, and lasted for 20 hours. The content of radioactive alanine in Y. pseudotuberculosis protein increased during 16 hours of cultivation at a high temperature, while at 8 degrees C the growth of the incorporation level lasted for at least 40 hours. For all precursors under study the incorporation rate into the cell biopolymers at the initial stages of cultivation was higher at 37 degrees C, than at a lower temperature.

Bacterial Proteins↗
PubMedDate not supplied

[Interactions of certain sapronotic infection pathogens in mixed cultures on a solid medium at different temperatures].

Under experimental conditions within the time limit of 21-35 days the causative agents of sapronotic infections in binary cultures, grown on a solid medium at 37 degrees C, 25-27 degrees C and 6-8 degrees C, interacted with one another transbiotically and through contact, their interactions having the character of amensalism, commensalisms-amensalism, competitive equilibrium, antibiosis. Irrespective of the initial density, a change in the species composition was observed, one of them playing the dominating role. At 37 degrees C mutual antagonism of Yersinia pseudotuberculosis and Pseudomonas aeruginosa killed both cultures. P. aeruginosa cells were also killed when cultivated at 37 degrees C jointly with Listeria monocytogenes, the most resistant species under experimental conditions. While studying the character of microorganisms interactions the method of contacting cultures on a solid medium was shown to give more information in comparison with the "cross-strip" method. Possible interspecific relationships between the causative agents of sapronotic infections under natural conditions are discussed.

Antibiosis↗
PubMedDate not supplied

[Method for the calculation of the 50% effective dose of biologically active agents].

A newly proposed method for the mathematical and graphic determination and calculation of ED50 (LD50) on the abscissa at the meeting point of the cumulate of dead and the cumulate of survived animals (in absolute figures) in "dose-effect) experiments is described. "The method of meeting cumulates) for the calculation of ED50 (LD50) is simple, eliminates unnecessary calculations, yields results, highly similar (95-100%) to those obtained by other methods and may be used in different medico-biological studies.

Animals↗
PubMedDate not supplied

[Effect of acceleration on pilot-sportsmen during aerial performances].

Cardiovascular responses of sports-pilots to aerobatic maneuvers have been inadequately studied. However many Soviet and foreign authors believe that acceleration effects may seriously deteriorate pilot performance. Our study has shown that cardiovascular changes are to maintain the necessary level of blood pressure in brain and eye arteries. During exposure to +Gz heart rate may be as high as 160 beats/min while during exposure to -Gz it may be as low as 60 beats/min. Pulse photoplethysmography recorded inflight has shown that during exposure to +Gz its amplitude decreases until pulse oscillations disappear, suggesting the development of visual disorders. Pulse photoplethysmography has revealed cardiac arrhythmias in the form of extrasystoles in some pilots. It has also been demonstrated that during flight cardiac arrhythmias can be best detected with the aid of correlation rhythmography.

Acceleration↗