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Biomedical subjects

G I Podoprigora

Publications and source records attributed to G I Podoprigora.

At least 37 records · Page 2Linked to original sources

[Fluorimetric determination of the concentration of histamine and serotonin in the mast cells of ordinary and germ-free rats following administration of reserpine and cyclic adenosine-3',5'-monophosphate].

The microspectrometric method was applied to the determination of the content of histamine (a test with orthophthalic aldehyde) and serotonin (Falk's test) in the mast cells of the mesentery of common and germfree rats. Reserpine (10 mg/kg of body weight, intramuscularly) failed to alter histamine content, whereas serotonin content fell by 50%. Administration of cyclic AMP (3.5 mg/kg of body weight, intraperitoneally) led to the increase in serotonin content by 80%, and histamine--by 280--320%.

Animals↗

[Barrier-fixing function in germ-free animals].

The state of barrier-fixative function was studied in germfree and conventional guinea pigs and rats. Under conditions of conventional animals contamination with E. coli 055 (in doses of 500 million and 10 milliard microbial bodies for subcutaneous and oral inoculation, respectively) only an early transitory bacteremia developed at the early postinfection periods. As to bacteriemia in gnotobiotes, it increased progressively leading to the animal death in the course of 2 to 3 days. A decreased fixative and bactericidal capacity of the regional lymphatic apparatus and deep structures of the mononuclear-phagocytic system was revealed in germfree animals. An experimental confirmation of the participance of antibodies in the manifestation of the barrier-fixative function to E. coli was obtained. These studies demonstrated an important role of the microbial factor in the formation of the macroorganism barrier-fixative function.

Animals↗

[Opsonizing activity of the serum of gnotobiotic guinea pigs contaminated with individual representatives of intestinal microflora].

The influence of contamination of germfree guinea pigs with individual representatives of the intestinal microflora (Bac. mesentericus, Bac. subtilis, S. albus, and S. faecalis) on the formation of the serum opsonic activity was studied. An increase of the opsonic activity to all the microorganisms on the 11th day after a corresponding monocontamination and a stimulating influence of the serum on the intracellular digestion of Bac. mesentericus and Bac. subtilis microbes was noted. As to the pathogenic microorganisms (E. coli 055), S. Faecalis only were capable of stimulating the serum opsonic activity. The results indicated the presence of an association between the microflora composition and the opsonic activity of the animal blood serum. The value of this index also depended on the properties of the phagocytosis object.

Animals↗

[Toxicity and proteolysis in gnotobiotic rats with thermal burns].

Experiments were conducted on germ-free (gnotobiotic) rats. A study was made of the toxic properties of the organs and the activity of proteolytic enzymes in them after thermal burns. Despite the absence of pathogenic microbial flora the germ-free rats developed the state of toxemia with an increase of the level of proteolytic enzymes. The extent of the toxic and catabolic reaction depended on the severity of the burn. Intoxication and an increase in proteolysis in the gnotobiotic rats were similar, and, in a number of cases greater than in usual animals. A conclusion was drawn on the important role of the tissue sources of intoxication in burns. A correlation between the toxemia and proteolysis was established.

Animals↗

[The gnotobiologic approach to the study of the body's non-specific resistance to infection].

A new methodological approach to the study of the organism resistance to infection with the use of experimental animals with controlled microflora (germfree and other categories of gnotobiotic animals) is considered. Characteristics of the state of natural resistance of germfree animals, revealing considerable defects of cellular and humoral protection mechanisms, are given. Findings of experimental studies into inflammation, phagocytosis and other reactions of nonspecific resistance in gnotobiotic animals, disclosing complex mechanisms of formation of these reactions under the influence of microflora, are presented. The etiological and pathogenetic role of the microbial factor in the development of infectious diseases and in the formation of mechanisms of protective reactions at various levels of integration of the organism are discussed. Conclusions concerning prospects of the gnotobiological approach in investigating the role of the microbic factor in pathology are set forth.

Animals↗

[Formation of cyclic adenosine-3',5'-monophosphate in phagocytosis].

The content of cAMP in the phagocytizing macrophages increased, especially in the phagocytosis of live microbes. cAMP formed in phagocytosis was determined in the incubation medium, whereas in the cells its content remained practically unchanged. In the administration of E. coli 055 to the germ-free guinea pigs the concentration of cAMP was found to be increased in the mucosa cells of the small intestine and in the blood serum; this fact indicated that adenylcyclase system participated in the reactions of the interrelations of the microorganisms with the epithelial cells of the smal intestiine.

Animals↗

[Effect of contamination of germ-free guinea pigs by individual representatives of the intestinal microflora on antibody and complement concentrations].

On the 3rd day after birth germ-free guinea pigs were contaminated with one of the following representatives of normal intestinal microbial flora: Bac. mesentericus, Bac. subtilis, S. albus, and S. faecalis. In the animals aged two weeks a study was made of the level of antibodies against the microorganisms used for monocontamination, and also to the E. coli O55 pathogenic for guinea pigs; the complement content in the serum was examined as well. Bac. mesentericus and Bac. subtilis contamination of guinea pigs altered the antibody content to these microbes but insignificantly, whereas S. albus and S. faecalis stimulated the antibody genesis considerably. Similar results were obtained in respect to E. coli O55. The complement level was markedly stimulated by the spore aerobes and S. albus.

Animals↗

[Study of the nature of toxic factors in burns on sterile guinea pigs].

Experiments were conducted on sterile and contaminated guinea pigs. The toxicity of the serum and the water-salt extracts of the internal organs after the burn was studied by the action on the leukocyte migration in a culture. Despite the complete absence of the microbial flora, the toxic properties of the serum and of the extracts of the internal organs of the sterile animals were the same as in the contaminated organs. The data obtained pointed to the important role of the histiogenic factors in the development of burn intoxication.

Animals↗