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Biomedical subjects

A V Nikitin

Publications and source records attributed to A V Nikitin.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Clinico-immunological aspects of idiopathic ventricular arrhythmia].

The clinicoimmunological study revealed immunocompetence dysfunction in 28 patients with idiopathic ventricular arrhythmias resistant to ritmilen. After sodium nucleinate immunomodulation, ritmilen therapy proved to be beneficial in 46.6% of the patients. A positive result was obtained only in the patients who showed the same or close values as in healthy individuals. The comparison has led to the conclusion that idiopathic ventricular arrhythmias are directly related to immune dysfunction and to the recommendation that sodium nucleinate should be used in the multimodality therapy of the arrhythmias.

Adjuvants, Immunologic↗
PubMed1992

[Study of the immunosuppressive effect of cyclosporine in experimental studies].

Specific immunosuppressive activity of cyclosporine prepared at the National Research Centre of Antibiotics by using its original producing culture was studied. It inhibited basic cellular immune responses such as DTH and transplant vs. host and prolonged the lifespan of tumor xenografts under the kidney capsule. Cyclosporine also suppressed the humoral immunity. Its inhibitory effect on lymphocyte blast transformation induced by lectins and in mixed lymphocyte cultures was shown in vitro. Cyclosporine inhibited activity of natural killer cells and T-suppressor cells induced by concanavalin A. It was demonstrated on the models of skin allotransplantation in mice and heterotopic transplantation of the heart in rats that cyclosporine prolonged the transplant lifespan. By the main indices of the cellular immunity and in the models of the transplantation immunity, cyclosporine prepared at the National Research Centre of Antibiotics was shown to be similar to that manufactured by Sandoz.

Abdomen↗
PubMed1992

[Effect of doxycycline on leukocyte adhesion in a multifactorial experiment].

The multifactorial analysis was applied to study the effect of doxycycline on leukocyte adhesion to a plastic within wide ranges of the values of experimental factors such as doxycycline concentrations and magnesium and calcium ions. The data were computer-processed and second-order equations characterizing the influence of the factors on adhesion were derived. It was shown that the effect of the ions on adhesion was non-single-valued; accurate quantitative models describing the ion effect on adhesion were developed when the concentration of doxycycline was changed.

Adhesiveness↗
PubMed1992

[Effect of doxycycline on immune response in a multifactorial experiment].

Multifactorial analysis was applied to studies on the effect of doxycycline on the primary immune response to sheep erythrocytes. The experimental factors were the following: the antibiotic dose, the antigen dose and the time of the onset of the antibiotic therapy with respect to the antigen action. Polynomial statistic models describing the delayed hypersensitivity and antibody titers within wide ranges of factor values were designed by the experimental data. It was shown that the prophylactic use of doxycycline prior to the antigenic stimulus markedly lowered the high-dose tolerance induced by high doses of the antigen.

Animals↗
PubMed1992

[Effects of rifampicin and doxycycline on the production of hydrogen peroxide by macrophages].

The influence of rifampicin and doxycycline on oxidative metabolism of macrophages was estimated in vitro by production of hydrogen peroxide. It was shown that low concentrations of rifampicin and doxycycline stimulated production of hydrogen peroxide by macrophages of guinea pigs. In concentrations of 1 to 10 micrograms/ml corresponding to the mean therapeutic ones doxycycline increased both the spontaneous and zymosan-induced production of hydrogen peroxide by the macrophages. The potentiating activity of doxycycline on the cells activated by opsonized zymosan was higher. The maximum increase in the induced production of hydrogen peroxide (by 40 per cent) was observed when the antibiotic concentration was 1 microgram/ml. Rifampicin in concentrations of 0.1 to 1 microgram/ml corresponding to the mean therapeutic ones stimulated the zymosan-induced production of hydrogen peroxide by the macrophages. The maximum increase in the production of hydrogen peroxide (by 22 per cent) was noted at the rifampicin concentration of 1 microgram/ml.

Animals↗
PubMed1992

[Experimental study of human recombinant insulin].

The experimental study of recombinant human insulin revealed its high specific activity. The kinetics of the hypoglycemic effect of various dosage forms of the insulin developed at the National Research Centre of Antibiotics and the dosage forms manufactured by Eli Lilly was similar. The pharmacological investigation of the dosage forms showed that they had no side effects on the vitally important organs and systems. It was concluded that the dosage forms of the gene engineered human insulin developed at the National Research Centre of Antibiotics did not differ by their characteristics from the analogous dosage forms manufactured in other countries.

Animals↗
PubMed1992

[Effect of combined preventive use of quadevit with antibiotics on the survival and humoral immune response in experimental studies].

An attempt to correct with quadevit immunodepression due to prophylactic administration of benzylpenicillin and gentamicin for 6 days provided positive results. There was a significant increase in the quantities of Ig 19S and Ig 7S after the animal immunization with the bacterial antigen, an increase in the number of the AFCs in the spleen of the albino mice in response to administration of sheep erythrocytes and an increase in the survival rate of the animals with salmonellosis. The simultaneous use of quadevit with cefamezine and erythromycin did not lower the unfavourable influence of the antibiotics on the immune status of the animals.

Amino Acids↗
PubMed1992

[Study of general toxic and organotropic properties of ampicillin combined with sulbactam].

The effect of sulacillin, a combination of sulbactam and ampicillin (1:2), on the functions of the liver and kidneys, peripheral blood count, cardiovascular and central nervous systems was studied in acute and chronic experiments on animals of various species. The allergenic and local irritating properties of the combination were also studied. It was shown that the combination was low toxic and the interaction of sulbactam and ampicillin by the lethal effect was additive. When the combination was administered intravenously to mice, its LD50 amounted to 6 g/kg. In chronic experiments on rats parenterally given the combination in doses equivalent to the therapeutic ones there were no changes in the examined systems and organs. When used in the doses exceeding the therapeutic ones, sulacillin used during long periods induced a transitory elevation of blood levels of transaminases and alkaline phosphatases, an increase in the relative weight of the liver and kidneys, elongation the typhlon and an increase in glycogen levels in the hepatocytes without morphological changes. The combination had no significant effect of sulacillin and the painful injections alleviated by local anesthesia were recorded. The allergenic properties of the combination were moderate and did not differ from those of ampicillin. The data indicate that the combined sulacillin preparation greatly resembles its foreign analogue.

Ampicillin↗
PubMed1992

[Multifactorial analysis of combined use of an antibiotic and peptidoglycan of microbial origin in experimental plague].

The combined effect of doxycycline and microbial peptidoglycan was studied with multifactorial analysis. The drugs were used preventively and therapeutically. The preventive use of doxycycline in the subtherapeutic doses in combination with the immunomodulator resulted in a significant increase in the survival rate rather than the average life-span (ALS) of the experimental animals. The therapeutic use of the drugs was more efficient than the preventive one and resulted in higher survival and ALS. By the results of the experiments polynomial statistic models of the second order were developed and the equal level curves characterizing the survival rate and ALS were plotted. The dose-time regimens of the combined use of doxycycline an peptidoglycan were optimized.

Animals↗
PubMed1992

[Multifactor study of combined effects of an antibiotic and polysaccharide in experimental infection].

Multifactorial analysis was applied to the study of the combined effect of doxycycline and a polysaccharide of microbial origin in experimental plague infection. A marked synergistic action of the antibiotic and polysaccharide used in subtherapeutic doses in treatment of the infection was observed. By the results of the experiments polynomial statistic models of the 2nd order were designed and nomographs or equal level lines were plotted. The models and nomographs described the animal survival rate and lifespan within a wide range of the control parameters. The dose/time regimens for the use of the polysaccharide combination with doxycycline were optimized on the basis of the multifactorial analysis.

Animals↗
PubMed1992

[Study of general toxic and organotropic properties of clindamycin in long-term experiments].

The action of clindamycin monohydrate on the general state and weight rise, liver and kidney functions, peripheral blood count and pathomorphological state of the viscera was studied on rats in chronic experiments. Clindamycin was administered to laboratory animals orally in doses of 50, 100, 150 and 300 mg/kg. It was shown that some adverse reactions to the drug and in particular disorders in blood coagulation and morphological changes in the intestine did not depend on its dose and were due to duration of the drug use and probable development of dysbacteriosis. At the same time the disorders in the liver and kidney functions though transitory did depend, to a greater extent, on the dose and were evident after the antibiotic overdosage.

Administration, Oral↗
PubMed1992

[Effect of rifampicin and doxycycline on leukocyte chemotaxis].

It was shown experimentally that in a dose corresponding to the average therapeutic one for man rifampicin was able to stimulate in vivo directed migration of neutrophils to the inflammation foci in mice CBA. Doxycycline used in a dose corresponding to the average therapeutic one was able to activate neutrophils and to increase chemotaxis. Intraperitoneal administration of doxycycline to guinea pigs induced liberation of large counts of neutrophils with marked segmentation of the nuclei to the peritoneal cavity. The cells induced by doxycycline had a higher capacity for chemotaxis under agarose as compared to the control.

Animals↗
PubMed1992

[The effect of endovascular laser therapy on the clinical course and on the mechanisms of antioxidant protection in bronchial asthma patients].

Among new non-medicamentous treatment methods, endovascular blood radiation with helium-neon laser (HNL) merits attention. The method turned out highly effective, which made it possible to reduce the maintenance doses of glucocorticosteroids, to increase the times of remission, and to restore work fitness. HNL was found to exert a stimulating effect on the blood antioxidant system.

Adult↗
PubMed1992

[Biologic activity and tolerance of a preparation of polyunsaturated fatty acids, obtained by a microbiological route ["biopolyene"]].

Biopolyene is a mixture of ethyl ethers of polyunsaturated fatty acids isolated from biomass of Entomophthora virulenta, a mycelial fungus. Its acute and chronic toxicity was studied on rats and guinea pigs. After oral administration of the preparation in single doses exceeding 50 g/kg there were no disorders in the general state of the rats. In chronic experiments with oral biopolyene in doses of 100 and 500 mg/kg and its local application to the intact skin of the animals in a dose of 1 g/kg there were no significant changes in the functional state of the liver and kidneys as well as the peripheral blood count. Insignificant changes in the serum levels of liver enzymes and coagulation were transient. The preparation showed no allergenic or immunomodulating effects. It had neither embryotoxic, teratogenic nor mutagenic action.

Administration, Cutaneous↗
PubMed1991

[Effect of rifampicin and doxycycline on the chemiluminescence of leukocytes].

The effect of rifampicin and doxycycline on spontaneous and zymosan-induced chemiluminescence of polymorphonuclear leukocytes was studied on guinea pigs. The cells were incubated in the presence of the antibiotics, washed and stimulated by zymosan. Under such conditions rifampicin in therapeutic doses of 0.1 to 10 micrograms/kg and doxycycline in a dose of 100 micrograms/kg potentiated the leukocyte chemiluminescence. Investigation of the antibiotics effect on the cells without washing failed because of the direct interference of rifampicin and doxycycline with the cell-independent stage of the chemiluminescent reaction.

Animals↗