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Biomedical subjects

V S Gurevich

Publications and source records attributed to V S Gurevich.

At least 19 recordsLinked to original sources
PubMed1992

[The regulation of protein kinase C activity in normal, immortalized and transformed rat fibroblasts].

In view of recent studies showing that cell proliferation of E1Aad5+c-Ha-ras-transformed fibroblasts cannot be regulated by growth factors and phorbol eaters in contrast to normal and E1Aad5-immortalized cell lines, the present work was undertaken to examine the role of protein kinase C (PKC) in the mitogenic signal transduction machinery in rat embryonal fibroblasts. It is shown that PKC is activated by acidic growth factor and phorbol esters in all the three cell lines. These findings suggest the existence of an additional, not associated with PKC-, growth-signaling pathway in E1Aad5-Ha-ras-transformed rat embryonal fibroblasts.

Animals↗
PubMed1992

[Alterations in the functional activity of platelets in patients with angina pectoris during the cold test].

The functional activity of platelets was examined in patients with coronary heart disease and healthy individuals during cold test (CT). Patients prone to vasospastic responses to CT exhibited platelet activation along with beta-thromboglobulin release and formation of spontaneous platelet aggregates. Comparison of functional changes in platelet functional activity which occurred during cold test and intravenous ergometrine test suggest that the response to CT may be substantially higher if platelet aggregability is concurrently determined. The unidirectional changes in platelet aggregability during cold and ergometrine tests in patients with signs of dynamic coronary occlusion may indicate a relation of platelets with coronary vasoconstriction.

Adult↗
PubMed1992

[Antioxidant activity of high density lipoproteins in vivo].

The paper deals with antioxidant effect of high density lipoproteins (HDL) in vivo. The effect of intravenous injection of large-dose HDL3 (200 mg protein), isolated from human plasma to rabbits with experimental hypercholesterolemia, on the content of primary products of lipid peroxidation in rabbit blood, the correlation between HDL cholesterol level and the content of lipid peroxide products in blood plasma of healthy persons and patients with IHD were studied. Intravenous injection of HDL3 to rabbits with experimental hypercholesterolemia has been shown to lead in 6 hr to a 24-hr significant (p < 0.01) decrease of conjugated dienes and trienes. The existence of negative correlation between HDL-cholesterol level and the content of conjugated dienes in blood plasma of healthy persons (N = 47) and patients with IHD (n = 64) is revealed. Basing on the data obtained conclusion of universal character of protective antiatherogenic effect of HDL is drawn.

Adult↗
PubMed1992

[The role of cholesterol in activating lipid peroxidation in platelets].

The relationship between the cholesterol (Ch) content and the concentration of lipid peroxidation (LPO) products in activated platelets and the effect of these parameters on the structure-function characteristics of platelet membranes were studied. It was found that esterified Ch activates free radical processes occurring in platelets. Nonesterified Ch does not induce the production of primary products of LPO (dienoic conjugates) but promotes the accumulation of a secondary LPO metabolite, malonic dialdehyde, this reaction being mediated via indirect mechanisms. The higher (in comparison with normal) orderliness and orientation of membranes in platelets reflect the increase in the concentration of dienoic conjugates and nonesterified Ch. The observed differences in the aggregability of platelets are due to the changes in the Ch content as well as to the "rigidity" of blood platelets.

Blood Platelets↗
PubMed1991

[Glutamate-binding membrane proteins from human platelets].

Solubilization of the total membrane fraction of human platelets in a 2% solution of sodium deoxycholate and subsequent affinity chromatography on glutamate agarose resulted in two protein fractions possessing a glutamate-binding activity. As can be evidenced from radioligand binding data, the first fraction contains two types of binding sites (Kd1 = 1 microM, Bmax 1 = 100 pmol/mg of protein; Kd2 = 9.3 microMm Bmax2 = 395 pmol/mg of protein). The second fraction has only one type of binding sites (Kd = 1 microM, Bmax = = 110 pmol/mg of protein). SDS-PAAG electrophoresis revealed the presence in the first fraction of proteins with Mr of 14, 24, 56 and 155 kDa, whereas the second fraction was found to contain 14, 46, 71 and 155 kDa proteins. Solid phase immunoenzymatic analysis using poly- and monoclonal specific antibodies against mammalian brain glutamate-binding proteins revealed a marked immunochemical similarity of the isolated protein fractions with human brain synaptic membrane glutamate-binding proteins.

Binding Sites↗
PubMed1991

[The effect of taurine on the electrically controlled ion channels of the somatic membrane of pond snail neurons].

Isolated and internally dialysed neurons from the molluscs Lymnaea stagnalis were investigated under voltage-clamp conditions. The increasing of taurin concentration (from 1.10(-8) to 1.10(-2) mol/l) reduced the calcium inward--and delayed potassium outward currents, and exerted no effect on the fast potassium outward current. Sodium inward current was increased by taurin concentrations 1.10(-8)-1.10(-4) mol/l, and reduced by 1.10(-3)-1.10(-2) mol/l. Membrane leakage currents were reduced by small taurin concentrations and increased by large concentrations.

Animals↗
PubMed1990

[A method of determining erythrocyte deformability].

A simple method for determining red cell deformability is suggested, based on red cell packing during centrifugation. This method was used to study red cell deformability in patients with essential hypertension and angina of effort and found it reduced.

Adult↗
PubMed1990

[Various indicators of vascular-thrombocytic hemostasis and blood rheology in ergometrine tests].

The function of platelets and erythrocytes and content of Willebrand's factor in the plasma from 45 patients with exercise-induced or spontaneous angina pectoris were examined before and after ergometrine, 0.1 mg. The patients with a negative ergometrine response showed a lower platelet sensitivity to all the aggregation inductors used in vitro, spontaneous platelet aggregation being absent. The function of erythrocytes and plasma levels of Willebrand's factor remained unchanged. The patients with a significant ischemic response to ergometrine exhibited platelet activation attended by the release of granule contents and formation of blood circulating platelet microaggregates. Concurrently, there was a decrease in erythrocyte deformability, as well as spontaneous blood red cell aggregation, the plasma levels of Willebrand's factor were increased 1.5-2-fold.

Aged↗
PubMed1990

[A rapid method of isolation of platelet membranes for radioligand and enzymatic assays].

A simple and rapid procedure for isolation of the total platelet membrane fraction by chromatography on Sepharose CL 6B has been developed. This method allows a rapid (25-30 min) one-step separation of the membrane fraction on 26 x 150 mm columns with a 20-21 mg recovery. The high degree of purity of membrane preparations was confirmed by a radioligand assay using [3H]adenosine and L-[3H]glutamic acid. The purity of membrane preparations is comparable with that of membrane fractions obtained by standard ultracentrifugation methods. The homogeneity of the membrane fraction was demonstrated by using marker enzymes of plasma, microsomal and mitochondrial membranes. This finding is very important in that it allows the isolation of fractions differing in their protein content with no effect on the method reproducibility. The high utility of the membrane preparations in receptor studies was demonstrated for high affinity binding sites for [3H]adenosine and L-[3H]glutamic acid.

Blood Platelets↗
PubMed1989

[Effects of ubinon-9, a synthetic antioxidant, on intensity of lipid peroxidation in blood platelets and plasma of patients with ischemic heart disease].

The antioxidant ubinon-9 was tested for its effects on platelet and plasma lipid peroxidation parameters in patients with acute ischemic heart diseases. The use of ubinon-9 in the multimodality therapy of patients with ischemic heart disease was shown to result in a significant decrease in lipid peroxidation intensity by enhancing superoxide dismutase activity in the platelets and plasma from the patients. Ubinon-9 equally prevented lipid peroxidation activation during enzymatic and nonenzymatic induction in the platelets of patients with unstable angina or acute myocardial infarction. Unlike a daily dose of 30 mg, 90 mg a day is a more effective dose in reducing platelet and plasma lipid peroxidation parameters. One may suggest that addition of ubinon-9 into the routine treatment regimen allows the therapy for acute ischemic heart disease to be optimize.

Adult↗
PubMed1989

[Functional status of thrombocytes and the anti-aggregative activity of the vascular wall in dyslipoproteinemias and ischemic heart disease].

Parameters of platelet aggregation under the influence of different ADP concentrations and vascular endothelial antiaggregation activity using a test of shoulder compression with a sphygmomanometer cuff were investigated in 46 persons aged up to 60 [14 examinees had type IIa hyperlipoproteinemia, (HLP), 10--type IIb, 10--type IV-V HLP, and 10 healthy donors]. CHD was diagnosed in 19 of 34 HLP patients. In 2 examinees CHD was unaccompanied by HLP. A raised amplitude of the aggregation of plates and a decrease in the threshold of their sensitivity to ADP were established in the persons with types IIa and IIb HLP and in CHD without HLP. In the examinees with type IV-V HLP the amplitude of platelet aggregation was lowered significantly, and the threshold of sensitivity to the inductor was raised. Endothelial antiaggregation activity in all types of HLP and in the persons with CHD without HLP was inhibited.

Adolescent↗