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Biomedical subjects

A A Byvalov

Publications and source records attributed to A A Byvalov.

9 recordsLinked to original sources
PubMed2005

[The role of the Yersinia plasmid of calcium-dependency in the formation of the plague immunity].

It was shown that viable variants of the Y. enterocolitica microorganisms containing the plasmid of Ca-dependency (native one or from EV/ I Y. pestis cells) were more immunogenic to plague-infected guinea pigs than isogenic non-plasmid variant. As a result of studying the protective properties of the bacteria Y. enterocolitica sub-cellular fractions it was determined that the largest quantity of immunogen per unit of protein was accumulated in the cultures of bacteria's plasmid variant. The aggregate of the obtained experimental data suggested that there was a non-identified protective antigen (or antigens) for guinea pigs to be encoded by chromosome's DNA. Besides, the Ca-dependency plasmid gene products take part in its excretion and, as the factors of pathogenicity, provide survivability of the Y. enterocolitica microorganisms in the host organism, increasing thus the immunogen accumulation in it.

Animals↗
PubMed2003

[Current understanding of the pathogenesis of infectious diseases].

New experimental data in such research fields as molecular biology, biochemistry, genomics and others as well as the changes occurring in the medical-and-epidemiological situation in respect to a number of infectious diseases dictate the necessity to systemize and to revise the appropriate knowledge for the purpose of ensuring a more profound understanding of the processes providing a foundation for the relations within the system of "host--parasite". The article deals with modern aspects of investigating the pathogenesis of infectious diseases, i.e. issues of the genetic and of structural-and-functional organization as well as of regulation of the pathogenetic potential of microorganisms; and mechanism of antimicrobial protection of microorganisms including from the standpoint of evolutionary biology.

Communicable Diseases↗
PubMed1991

[Connection of outer membrane protein composition in Yersinia pestis cells with intrinsic plasmids].

A set of isogenic derivatives of Yersinia pestis EV strain was obtained including the variants harbouring the different compositions of Yersinia own plasmids. The protein profiles of outer membranes of the set of strains were defined. The polyacrylamide gel electrophoresis has shown the small 6.1 Md plasmid to code an outer membrane protein with mol mass 29 kDa, different from pesticin I, while the heavy 60.0 Md plasmid encodes the 15-16 kDa polypeptide different from monomers of F1 and T-antigens of plague microbe.

Antigens, Viral↗
PubMed1984

[Effectiveness of revaccinating hamadryas baboons with NISS live dried plague vaccine and fraction I of the plague microbe].

The effectiveness of some vaccine preparations for the revaccination of hamadryas baboons after their primary immunization with live plague vaccine " NIIS " administered in the form of aerosol was studied. The study was carried out under the conditions of the aerosol challenge of the animals with Y. pestis. The subcutaneous injection of plague vaccine " NIIS " was found to have advantages over its aerosol administration. Revaccination with Y. pestis fraction I, absorbed, was found to be 8 times more effective than the administration of plague vaccine " NIIS " by inhalation and not inferior to the subcutaneous injection of this vaccine. Y. pestis lipopolysaccharide, when injected simultaneously with fraction I, produced an immunosuppressive effect. The development of chemical plague vaccine on the basis of fraction I, intended for revaccination, was shown to have good prospects.

Aerosols↗
PubMed1982

[Experience using fraction I of the plague microbe for revaccinating experimental animals].

Experiments on guinea pigs have shown that a pronounced revaccination effect develops in the animals receiving the booster injection of fraction I of Pasteurella pestis 1.5--4 months after the primary immunization with live plague vaccine, while the booster injection of live plague vaccine produces a low revaccination effect due to the fact that this vaccine is badly adapted in the body after the primary immunization.

Animals↗
PubMed1979

[Experimental protective of fraction I of the plague microbe].

The immunogenic properties of the freeze-dried preparation of fraction I tisolated from the culture of avirulent Pasteurella pestis strain were studied in experiments on hamadryas baboons, guinea-pigs and white mice. The preparation was found to have a pronounced protective effect in hamadryas baboons and white mice, especially when the preparation was used in mixture with incomplete Freund adjuvant. In hamadryas baboons resistance to infection was shown to correlate with hemagglutionation antibody titres.

Adjuvants, Immunologic↗
PubMedDate not supplied

[Immunogenicity of B-antigen in experimental plague and pseudotuberculosis].

The results of the evaluation of the immunogenic properties of B-antigen, earlier identified in the culture fluid of Yersinia pseudotuberculosis submerged culture, with respect to experimental plague and pseudotuberculosis are presented. B-antigen has been shown to produce protective effect in guinea pigs and, probably, hamadryas baboons, but not in white mice infected with the causative agent of plague. Immunizaton with B-antigen protects guinea pigs from primary pneumonic plague caused by both capsule-forming and noncapsular Y. pestis virulent strains. Passive immunization with antibodies to B-antigen induces limitedly pronounced protective effect in guinea pigs and is not effective for white mice with respect to experimental plague. No active or passive protection of white mice or guinea pigs, infected with Y. pseudotuberculosis cultures, has been achieved by the injection of B-antigen or antibodies to it.

Animals↗