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Biomedical subjects

S V Demidov

Publications and source records attributed to S V Demidov.

13 recordsLinked to original sources
PubMed1991

[Ca(2+)-dependent regulation of T-lymphocytes in experimental tuberculosis].

Ca(2+)-exchange kinetics and the content of membrane and cytoplasm fractions of calmodulin in the splenic T-lymphocytes of guinea pigs with experimental tuberculosis were studied. A tuberculous process was accompanied by the changes in the Ca2+ exchange kinetics in the form of T-lymphocyte oversaturation with Ca2+ ions which in the end leads to an inhibition of the functional status of the immunity T system. PPD, a specific allergen, brought the capacity of T lymphocytes down in relation to the cellular Ca2+ exchange, presumably causing the normalization of the immune response.

Animals↗
PubMed1991

[Lymphocyte cytotoxic activity in radiation lesions].

A study is presented of the effect of roentgen radiation on the cytotoxic activity and spontaneous rosette formation of guinea pig lymphocytes. The animals were irradiated by roentgen rays in 2.58 mC/kg and 180.60 mC/kg. Results indicate that 24 hours after irradiation there was a significant reduction of the cytotoxic activity (38% as compared with the control) and doses-dependent reduction of rosette formation cells.

Animals↗
PubMed1991

[Effect of thymus preparations and anti-tuberculosis agents on immunologic reactivity and the course of the tuberculosis process in experimental animals].

The effects of thymogen, thymalin and vilosen in combination with antituberculous drugs (isoniazid, streptomycin, rifampicin) were studied on 240 CBA mice with experimental tuberculosis. Thymus preparations supplemented to the complex treatment of experimental tuberculosis significantly increased their lifespan, contributed to a decrease in the index of spleen weight lung density and significantly increased the count of T lymphocytes and their proliferative activity as compared to those on antituberculous drugs alone. Thymogen was found to be the most effective in the complex treatment of experimental tuberculosis, whereas vilosen was the least. Thymogen plus vilosen proved to be the most beneficial combination of drugs.

Adjuvants, Immunologic↗
PubMed1990

[Effect of thymic immunomodulators on the system of cyclic nucleotides of splenic T-lymphocytes after BCG vaccination].

The experiments on guinea pigs was performed to study the effects of thymogen , thymalin and vilosene on the activity of cAMP, cGMP, adenylate cyclase, guanylate cyclase, cAMP- and cGMP-phosphodiesterases in T lymphocytes during BCG vaccination. It was shown that the disease was accompanied by increased activity of enzymes of anabolism and catabolism of cyclic nucleotides. Thymogen and thymalin mainly activated the synthesis of cGMP, thus causing the shift of cAMP/cGMP value below the reference level. At the same time vilosene increased this value in the process of a repeated BCG injection.

Adenylyl Cyclases↗
PubMed1988

Serine proteinase esterolytic activity as an assay of cytotoxic reactions.

A method for assessing cytotoxicity in cell-mediated cytolysis as well as in reactions of natural killing and antibody-dependent cellular cytotoxicity through assaying the total esterolytic activity of serine proteinases (TEASP) is both sensitive and specific. TEASP levels in all cytotoxic tests correlated with the percentage of lysis of 51Cr-labelled target cells. The method permits the differential assessment of endoproteases in both the effector cell and the target cell.

Adult↗
PubMedDate not supplied

[Effect of thymagen, thymalin and vilosen on the cAMP and cGMP levels and phosphodiesterase activity in spleen lymphocytes during sensitization and anaphylactic shock].

It is established that the effect of thymus-derived species is connected with the cyclic nucleotide system. The action of thymus-derived immunocorrectors (thymalin, thymagen, vilosen) on catabolic processes of cyclic nucleotides has been observed under conditions of anaphylaxy and sensibilization. They show that sensibilization of the animal is bound up with a decrease of the cAMP/cGMP ratio. Anaphylaxis induces levelling of the cAMP/cGMP ratio up to the reference level. So, activity of enzymes of cyclic nucleotide catabolism grows due to the influence of thymogen, thymalin and vilosen in lymphocytes of sensibilized guinea pigs and tends to an increase in lymphocytes of anaphylaxis-treated animals.

Adjuvants, Immunologic↗
PubMedDate not supplied

cAMP and cGMP (EVE) changes in immune competent cells under sensibilization and anaphylactic shock of animals of different age.

The studies performed proved that there were no substantial differences in intracellular content of cAMP and cGMP in immune systems of both old and young animals. The influence of equine serum upon lymphocytes in accompanied by the most substantial changes in concentrations of cyclic nucleotides in spleen B-cells. The amplitude of level changes in cAMP and cGMP in these cells under anaphylactic shock doubles the value of old animals. Thus together with genetically preprogrammed change in functional activity of immune competent cells, expressed in different force of immune response, the correlative changes in cyclase system of animals of different ages have been observed.

Age Factors↗
PubMedDate not supplied

[Decrease in adenylate cyclase activity in spleen T- and B-lymphocytes and thymus T-lymphocytes in CBA mice treated with levamisole].

The influence of various concentrations of levamisole on the activity of the membrane adenylate cyclase complex of lymphocytes is analyzed. It is ascertained that levamisole decreases the activity of adenylate cyclase at a concentration of 10(-9)-10(-7) M in thymic lymphocytes, and that the activity of the enzyme in spleen T- and B-lymphocytes remains constant. The influence of levamisole on the activity of adenylate cyclase thymocytes is studied under conditions of its stimulation by NaF, GTF and adrenaline. It is ascertained that levamisole at a concentration of 10(-9)-10(-7) M decreases the activity of the enzyme stimulated by NaF, GTF and adrenaline.

Adenylyl Cyclase Inhibitors↗
PubMedDate not supplied

[Comparison of acceptor activity of rabbit liver tRNA in ontogenesis].

The rabbit liver tRNA was studied in such functional states when there occurred essential qualitative and quantitative changes in the protein synthesis. On the basis of the maximum level of aminoacylation it is established that the contents of corresponding biologically active individual tRNA in the total preparation for adult animals is 1.5-3 times as high as that for 3-5 day rabbits. Exception is alanine tRNA whose number decreases sharply in the total preparation of the liver tRNA of one- and two-year animals. No correlation was found for any age group between the quantitative ratio of active individual tRNA and the amino acid composition of albumins whose synthesis in the liver is intensive. Thus, the synthesis and, respectively, the content of certain types of tRNA in the liver characterized by a wide spectrum of proteins with different functions are governed by other regularities, whose search is one of the most difficult and at the same time high-promising problems.

Aging↗