PubMed HealthSearch

Biomedical subjects

B D Bychenko

Publications and source records attributed to B D Bychenko.

At least 19 recordsLinked to original sources

[The development of a new generation of pertussis vaccine].

The results of the weight gain test on mice have shown that acellular pertussis vaccine is less toxic than the pertussis component of adsorbed diphtheria-pertussis-tetanus (DPT) vaccine due to a lower content of endotoxin in the acellular vaccine; but the leukocytosis-promoting and histamine-sensitizing activities of JNIH-6 and adsorbed DPT vaccines are indicative of incomplete inactivation of Bordetella pertussis toxin. The content of incompletely inactivated B. pertussis toxin is practically the same in both preparations, constituting 1/100-1/200 of the calculated initial activity. For this reason, the use of the new pertussis vaccine also involves a risk of development of serious postvaccinal reactions and/or complications caused by this toxin. Search for the optimum method of inactivation of B. pertussis main toxin should be continued. As shown by the enzyme immunoassay, acellular pertussis vaccine used in the same immunizing dose as adsorbed DPT vaccine induces a more intensive immune response to hemagglutinin and B. pertussis toxin. This is due to higher residual toxicity of the corpuscular component of adsorbed DPT vaccine. Induction of antibodies to B. pertussis toxin has been shown to decrease in response to injection of acellular pertussis vaccine containing a certain residual amount of incompletely inactivated B. pertussis toxin.

Animals

[Determination of the biological activity of Clostridium difficile toxins in in vivo and in vitro experiments].

The biological activity of the filtrates of 29 C. difficile strains was studied in vivo (suckling white mice) and in vitro (cell cultures of different species and origin). The action of the filtrates on the experimental models in vivo was evaluated from the cytotoxic effect index, while in vitro the intensity of the cytotoxic effect was evaluated from the percentage of dead cells in the monolayer. The results of the comparative determination of toxicity characteristics in vivo and in vitro demonstrated that cell cultures were more sensitive experimental models than suckling white mice. The use of cell cultures permitted the quantitative evaluation of the cytotoxic activity of the filtrates under study, as well as the detection of their cell-directed action at minimal concentrations.

Animals

[Differentiation of the main species of Clostridium by gas chromatography].

For the first time in the USSR the properties of microorganisms of the genus Clostridium have been studied with the use of the gas-chromatographic techniques. The analysis of the quantitative and qualitative composition of extracellular alcohols and carboxylic acids in 99 museum and newly isolated strains of 18 Clostridium species has made it possible to classify these microorganisms with 7 sharply differing groups. The above techniques permit the classification of clostridia with one of the groups within 2 hours if the microbial cultures have been grown in glucose-containing peptone yeast medium.

Chromatography, Gas

[Anaerobic bacteria from microbial foci in acute odontogenic inflammatory diseases].

Mixed microbial associations from purulent foci of 30 patients with odontogenic inflammatory diseases were studied. 18 specimens of the clinical material were subjected to three-fold investigation. Bacteroids, propionic bacteria and pentococci predominated in the mixed cultures. Nonpathogenic Neisseria, streptococci of the mitis-salivarius group and epidermal staphylococci were isolated from the facultative anaerobic flora. The anaerobic species were the most sensitive to the antibiotics used in the treatment of the patients.

Acute Disease

[Possibility of peroral revaccination against tetanus].

The authors present the results of oral revaccination of volunteers by purified tetanus toxoid. It appeared that in a dose of 500 BU tetanus toxoid covered with no special coat, produced no immunological effect. As to the coated toxoid-the same dose produced and increase in the antitoxin titre to the protective level, and greater.

Administration, Oral