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Biomedical subjects

I A Basnak'ian

Publications and source records attributed to I A Basnak'ian.

At least 19 recordsLinked to original sources
PubMed2004

[Antigen properties of oral intake whole-culture preparations from Neisseria meningitides of serogroups A, B and C].

A new technology of deriving the whole-culture peroral meningococcal mono-vaccines of serogroups A, B and C from the acetone-inactivated cultures was experimentally substantiated. The latter cultures were obtained through computer-aided continuous-flow cultivation of Neisseria meningitides of the above serogroups in the bioreactor with a synthetic nutrient medium. The whole-culture meningococcal mono-preparation of 3 serogroups comprised a complete set of antibodies, i.e. polysaccharides (PS), external membrane proteins (EMP) and lipopolysaccharides (LPP), in their native condition. High levels of IgG to PS, EMP and LPP were detected in blood sera of rabbits, which had been perorally immunized by the above preparations; such high levels persisted for a long time (303 days--observation period). It is noteworthy, that in accumulating of IgG to all investigated antigens of meningococcus of serogroups A and C, the optimal doses of whole-culture peroral monovaccines did not exceed the culture doses used to derive the hyper-immune sera at intravenous immunization.

Administration, Oral↗
PubMed2001

[Cold shock in bacteria].

Various species and genera of bacterial show the same responses to low temperature. Cold induces cold shock genes, by causing significant changes in the regulation of protein synthesis. The synthesis of major proteins in the microbial cell is suppressed. However, there is synthesis of a great deal of new proteins, the so-called cold shock ones. The chief protein in this family is E. coli CspA that activates the translation of other cold shock genes and negatively regulates the expression of its own gene. E. coli CspA homologies were identified in many bacteria. They can be also identified in other microorganisms, including the pathogens of infectious diseases. This can be attributable to the presence of common antigens in different bacteria. The data presented should be borne in mind in identifying bacteria and in designing immunodiagnostic agents if there is a culture cooling stage in their technology.

Bacillus subtilis↗
PubMed1999

[Impact of stressors on serogroup B neisseria meningitidis outer membrane proteins during cultivation in bioreactor].

The authors examined the antigenic complexes obtained from serogroup B Neisseria meningitidis strain 125 cells grown in the bioreactor to different phases of growth in the reaction of gel precipitation and counter immunophoresis in a periodical fashion. A set of serotypic antigens was shown to increase from 3 to 9 with cultural growth. Their largest quantities were seen in the cells grown till the end of the stationary growth phase, the concentration of high-molecular weight peptides rising from 19% (in the exponential growth phase cells) to 54% (in the stationary growth phase ones). The revealed regularities were evidenced by gel precipitation examinations of the sera from rabbits immunized with meningococci grown till different growth phases. At the same time, there were the largest quantities of serotypic antigenic precipitation bands when the sera obtained in the culture grown till the end of the stationary growth phase were used. It cannot be excluded that the results depend on the combined effects of several stressors on Neisseria meningitidis in the transition from the exponential to stationary growth phase, as resulted from the increased synthesis of high-molecular weight proteins that seem to act as protectors.

Animals↗
PubMed1992

[The antibody response of animals to a corpuscular meningococcal group-B preparation with different methods of immunization].

As revealed in animal experiments, the formation of antibodies to group-B N. meningitidis antigens (group-specific polysaccharide, lipopolysaccharide and outer membrane proteins) in response to administration of meningococcal corpuscular preparations depends on the method of administration, the dose, and the number of administrations. In the sera of rabbits, immunized orally, antibodies to all three antigens in sufficiently high titers have been detected.

Administration, Oral↗
PubMed1990

[A comparative study of the immunogenicity of 2 group-B meningococcal vaccines in monkeys].

The comparative study of two group B meningococcal vaccines manufactured in the USSR and in Cuba was made. The vaccine manufactured in the USSR contained the noncovalent compound of group B Neisseria meningitidis polysaccharide and outer membrane protein, and the Cuban vaccine contained group B N. meningitidis outer membrane proteins and group C N. meningitidis polysaccharide. The data obtained in this study indicated that both vaccines possessed immunological potency evaluated according to their capacity to stimulate the formation of bactericidal antibodies, whose level was found to increase eightfold after the immunization of monkeys in two injections. Besides, group B meningococcal vaccines did not induce the suppression of nonspecific protective activity characteristics of the body and did not stimulate the formation of autoantibodies to brain and liver tissues, which was indicative of the safety of these vaccines.

Animals↗
PubMed1990

[The regulating action of oxygen on the nutritional requirements of Neisseria meningitidis].

The study has revealed regularities in changing nutritional requirements of Neisseria meningitidis with changes in the degree of the oxygen saturation of the culture medium in a fermenter under the conditions of the controlled cultivation of N. meningitidis in a synthetic culture medium in the process of batch, semicontinuous and continuous flow cultivation. As shown in this study, when oxygen supply is limited, the consumption of carbohydrates prevails, while in the presence of surplus oxygen the prevalence of the consumption of amino nitrogen is observed.

Amines↗
PubMed1990

[The sorption of a protein-polysaccharide complex isolated from Neisseria meningitidis serogroup B on aluminum hydroxide gels and the immunological activity of the sorbed preparations].

The protein-polysaccharide complex, isolated from group B N. meningitidis, is a variant of vaccine for the prophylaxis of group B N. meningitidis infection. In this investigation the influence of the complex of the physical properties of aluminium hydroxide gels, the amount of gel, pH and the duration of sorption on the process of sorption has been studied. Aluminium hydroxide has been shown to produce a stimulating effect on the response of mice to the polysaccharide and protein contained in the complex after immunization made in two injections. Gels with a smaller particle size have been found to possess greater adjuvant activity, as well as greater absorbing activity. The immunological activity of the complex, adsorbed ex tempore, has proved to be no different from that of the complex adsorbed in an hour.

Aluminum Hydroxide↗
PubMed1990

[The reactogenicity and antigenic activity of a meningococcal group B vaccine made from a natural complex of the specific polysaccharide and outer membrane proteins].

Group B meningococcal vaccine consisting of the natural complex of specific polysaccharide and outer membrane protein (OMP) has been shown to be moderately reactogenic, safe with respect to the effect of undermining tolerance to human brain tissue antigens and to produce no allergization of humans. The vaccine under study possesses antigenic activity: (a) immunization with this vaccine ensures the fourfold rise of the level of antibodies to the group-specific polysaccharide of group B meningococcus in about 80% of persons with the initially low level of antibodies, this percentage being retained during the whole period of observation, i. e. 85 days; (b) the vaccine enhances the level of antibodies to meningococcal OMP, determined in the enzyme immunoassay and the passive hemagglutination test; (c) these data are indicative of the expediency of immunizing the risk groups of persons with the initially low level of antibodies.

Adult↗
PubMed1990

[The immunobiological properties of the antigenic preparations obtained from a vaccinal strain of Klebsiella pneumoniae 204 grown in media of differing compositions].

In the technology of the cultivation of K. pneumoniae vaccine strain 204 with a view to obtaining biomass for the production of antigenic preparations the traditionally used culture medium with full nutritional value has been replaced by the alternative variant of synthetic medium. The specific physiological and morphological features of this strain grown in synthetic culture medium have been studied and described. Irrespective of the composition of the culture media used for cultivation, the antigenic preparations have been shown to have no difference in their chemical composition, immunogenic and toxic properties.

Animals↗
PubMed1989

[Microcapsule formation in the cells of Neisseria meningitidis group B].

The formation of the rutheniophilic microcapsule was studied in 5 meningococcal strains, group B, in accordance with the data of transmission electron microscopy. The microcapsular group-specific meningococcal polysaccharide was shown to enter into a specific osmiophilic reaction with ruthenium red. The study revealed that the formation of the microcapsule was practically independent of the concentration of serum, ferric chloride and amino-nitrogen in the medium in the ranges used in the experiments (0-20%, 0-32 mg/l and 49-160 mg% respectively). As noted in this study, the presence of serum in the medium led to the formation of the pseudocapsule on the surface of meningococci. The intensity of the formation of the microcapsule was shown to depend on the phenotypical properties of definite strains, on the phase of bacterial growth (it reached its maximum values at the exponential phase), as well as on the concentration of glucose in the medium.

Culture Media↗