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Biomedical subjects

V B Sadovnikov

Publications and source records attributed to V B Sadovnikov.

At least 37 records · Page 2Linked to original sources
PubMed1992

Extracellular diaphorase-like activity as a marker of cytolytic damage to cells.

A new variant of the enzyme release colorimetric method for NK/LAK cytotoxicity is described. Kinetic determination of diaphorase released from damaged target cells (TC) provided an exact measurement of the lytic activity of effector cells (EC). A polyenzyme testing system permitted the use of a wide spectrum of TC. The percentage cytotoxicity and the kinetics of the process coincide, within experimental error, with data from staining with Trypan blue. The method is simple and convenient and can be applied to study cell-mediated cytotoxicity (CMC).

Biomarkers↗
PubMed1991

[Immunochemical study of antigenic determinants of surface protein s of the tropical malaria pathogen Plasmodium falciparum using synthetic peptides].

To develop new approaches to diagnostics and therapy of malaria, we carried out immunochemical study of the surface proteins of the tropical malaria parasite Plasmodium falciparum with the use of synthetic peptides corresponding to the suggested antigenic determinants of the parasite proteins. Rabbit antisera raised against the synthetic peptides bound to parasite proteins as shown by ELISA and immunoblotting. Affinity purified anti-peptide antibodies inhibited, in some cases, the parasite growth in the human erythrocytes culture.

Amino Acid Sequence↗
PubMed1990

Inhibition of neutrophil-mediated lysis of syngeneic erythrocytes by components of blood serum and peritoneal fluid.

Experiments are reported in which it is shown that murine blood serum and peritoneal fluid contain compounds of high molecular mass that inhibit the lysis of murine erythrocytes caused by syngeneic neutrophils, and that these inhibitors directly affect the neutrophils. Neutrophil sensitivity to phorbol 12-myristate 13-acetate (PMA) changes in the presence of these high-molecular-mass serum components, whereas their sensitivity to opsonized zymosan does not.

Animals↗
PubMedDate not supplied

[The effect of orthofen (diclofenac) on the embryogenesis of laboratory mice].

The effect of ortophen on the embryogenesis of laboratory mice of two inbred lines BALB/c and C57B1/6 and of outbred stock NMR was studied. The drug was injected intraperitoneally on days 1-6, 6-16, and 16-18 of pregnancy in a therapeutic dose (1 mg/g) and 10-fold doses. General development of the fetuses was delayed and the condition of the pregnant females of both lines and the stock deteriorated on injection of the drug in a 10-fold dose on days 16-18 of pregnancy. BALB/c mice proved to be most sensitive to the unfavorable effects of sodium diclophenac.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

[Stimulation of murine natural killer cells by weak electromagnetic waves in the centimeter range].

Irradiation with electromagnetic waves (8.15-18 GHz, 1 Hz within, 1 microW/cm2) in vivo increases the cytotoxic activity of natural killer cells of rat spleen. In mice exposed for 24-72 h, the activity of natural killer cells increased by 130-150%, the increased level of activity persisting within 24 h after the cessation of treatment. Microwave irradiation of animals in vivo for 3.5 and 5 h, and a short exposure of splenic cells in vitro did not affect the activity of natural killer cells.

Animals↗
PubMedDate not supplied

[Effect of extremely high frequency electromagnetic radiation of low intensity on parameters of humoral immunity in healthy mice].

The modification of indices of the humoral immune response to thymus-dependent antigen (sheep erythrocytes) after a whole-body exposure of healthy mice to low-intensity extremely-high-frequency electromagnetic radiation was studied. Male NMRI mice were exposed in the far-field zone of horn antenna at a frequency of 42.0 GHz and energy flux density of 0.15 mW/cm2 under different regimes: once for 20 min, for 20 min daily during 5 and 20 successive days before immunization, and for 20 min daily during 5 successive days after immunization throughout the development of the humoral immune response. The intensity of the humoral immune response was estimated on day 5 after immunization by the number of antibody-forming cells of the spleen and antibody titers. Changes in cellularity of the spleen, thymus and red bone marrow were also assessed. The indices of humoral immunity and cellularity of lymphoid organs changed insignificantly after acute exposure and series of 5 exposures before and after immunization of the animals. However, after repeated exposures for 20 days before immunization, a statistically significant reduction of thymic cellularity by 17.5% (p < 0.05) and a decrease in cellularity of the spleen by 14.5% (p < 0.05) were revealed. The results show that low-intensity extremely-high-frequency electromagnetic radiation with the frequency and energy flux density used does not influence the humoral immune response intensity in healthy mice but influences immunogenesis under multiple repeated exposures.

Animals↗
PubMedDate not supplied

[Suppression of nonspecific resistance of the body under the effect of extremely high frequency electromagnetic radiation of low intensity].

The dynamics of leukocyte number and functional activity of peripheral blood neutrophils under whole-body exposure of healthy mice to low-intensity extremely-high-frequency electromagnetic radiation (EHF EMR, 42.0 GHz, 0.15 mW/cm2, 20 min daily) was studied. It was shown that the phagocytic activity of peripheral blood neutrophils was suppressed by about 50% (p < 0.01 as compared with the sham-exposed control) in 2-3 h after the single exposure to EHF EMR. The effect persisted for 1 day after the exposure, and then the phagocytic activity of neutrophils returned to the norm within 3 days. A significant modification of the leukocyte blood profile in mice exposed to EHF EMR for 5 days was observed after the cessation of exposures: the number of leukocytes increased by 44% (p < 0.05 as compared with sham-exposed animals), mostly due to an increase in the lymphocyte content. The supposition was made that EHF EMR effects can be mediated via the metabolic systems of arachidonic acid and the stimulation of adenylate cyclase activity, with subsequent increase in the intracellular cAMP level. The results indicated that the whole-body exposure of healthy mice to low-intensity EHF EMR has a profound effect on the indices of nonspecific immunity.

Animals↗
PubMedDate not supplied

[Effects of low-intensity extremely high frequency electromagnetic radiation on chromatin structure of lymphoid cells in vivo and in vitro].

Using a comet assay technique, it was shown for the first time that low-intensity extremely high-frequency electromagnetic radiation (EHF EMR) in vivo causes oppositely directed effects on spatial organization of chromatin in cells of lymphoid organs. In 3 hrs after single whole-body exposure of NMRI mice for 20 min at 42.0 GHz and 0.15 mW/cm2, an increase by 16% (p < 0.03 as compared with control) and a decrease by 16% (p < 0.001) in fluorescence intensity of nucleoids stained with ethidium bromide were found in thymocytes and splenocytes, respectively. The fluorescence intensity of stained nucleoids in peripheral blood leukocytes was not changed after the exposure. The exposure of cells of Raji hunan lymphoid line and peripheral blood leukocytes to the EHF EMR in vitro induced a decrease in fluorescence intensity by 23% (p < 0.001) and 18% (p < 0.05), respectively. These effects can be determined by changes in a number of physiological alkali-labile sites in DNA of exposed cells. We suggested that the effects of low-intensity EHF EMR on the immune system cells are realized with the participation of neuroendocrine and central nervous systems.

Animals↗
PubMedDate not supplied

[Decrease in the intensity of the cellular immune response and nonspecific inflammation upon exposure to extremely high frequency electromagnetic radiation].

The effect of low-intensity extremely high-frequency electromagnetic radiation (EHF EMR, 42.0 GHz, 0.1 mW/cm2, 20 min daily) on cell-mediated immunity and nonspecific inflammatory response in mice was studied. The intensity of cell-mediated immune response in the reaction of delayed-type hypersensitivity and nonspecific inflammation was estimated by a relative increase in the thickness of foot pad after immunization of animals by sheep red blood cells or zymosan. It was shown for the first time that the radiation reduces both immune and nonspecific inflammatory responses. It was shown with the use of models of acute inflammation and full-thickness skin wounds that EHF EMR suppresses the nonspecific inflammatory response but does not influence the duration of the pathological process. We suppose that the basis of the effects revealed is the modification of functional activity of phagocytic cells under the influence of EHF EMR. The results suggest that some therapeutic effects of EHF EMR can be realized via the inhibition of inflammatory processes.

Animals↗
PubMedDate not supplied

[An ACTH-like peptide immunocortin: effect on the activity of cells from the rat adrenal cortex].

The effect of immunocortin, an ACTH-like decapeptide VKKPGSSVKV corresponding to the 11-20 sequence of the variable part of the human IgG1 heavy chain on the content of 11-hydroxycorticosteroids (CS) in rat adrenal glands and blood serum in vivo was studied. An intramuscular injection of immunocortin at a dose of 10 microg/kg was found in an hour to induce a twofold decrease in CS content in the adrenal glands and a 1.8-fold increase in the blood serum CS content. At the same time, an immunocortin dose of 100 microg/kg exerted practically no effect on the CS content and its dose of 1000 microg/kg increased the CS content both in adrenal glands and in blood serum by 1.6 and 2.2 times, respectively. Four hours after the injection of any of the three doses of immunocortin, the CS content in adrenal glands did not differ from the control value, and after 24 h the content decreased threefold. Immunocortin was shown to be bound by the ACTH receptors in the membranes of the rat adrenal cortex with a high affinity and specificity (inhibiting the specific binding of 125I-labeled ACTH-(11-24) peptide with Ki of 1.2 nM).

11-Hydroxycorticosteroids↗
PubMedDate not supplied

[Ultrafast freezing of the embryos of outbred and inbred mouse strains].

Survival of 8-cell mouse embryos of inbred strains C57B1 and DBA and outbred strain NMRI was studied after ultrafast freezing. The embryos were placed in 10% glycerol for 10 min, transferred in plastic tubes filled with a mixture of glycerol and 1 M sucrose (3:7), and immersed in liquid nitrogen within 1.5 min. The tubes were thawed in air at the room temperature, the embryos were washed in 0.5 M sucrose and cultivated in a Dulbecco medium with 20% fetal calf serum at 37 degrees C for 48 h or transplanted to recipient females. The survival of embryos was estimated according to their capacity to develop in vitro to the blastocyst stage or form normal fetuses after transplantation. After thawing and cultivation, 80.4% of NMRI embryos retained viability (80.7% in the control). For C57B1 and DBA embryos, these indices were 90.2 and 88.7%, and 59.3 and 66.7%, respectively. The differences between the experiment and control was insignificant for all strains. After thawing and transplantation of NMRI embryos, 34.4% developed into normal live fetuses (in the control 33.3%). At the same time, after cryoconservation by the standard method using a programmed freezer, the viability of ICR and NMRI embryos decreased approximately by 20% even in in vitro experiments. Thus, no differences were found in survival of the embryos of the studied strains after ultrafast freezing. This method proved to be very efficient for the embryos of both inbred and outbred mouse strains, since their capacity for development practically did not decrease after cryoconservation. The method may be used for production of cryobanks of embryos of various mouse strains.

Animals↗