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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
PubMed2002

[Influenza virus infection in progressing atherosclerosis].

AIM: To study relationship between influenza virus infection and activity of clinical presentations of atherosclerosis. METHODS AND RESULTS: Average blood level of IgG to influenza A virus was significantly higher in patients with progressing forms of ischemic heart disease then in patients without objective signs of exacerbation of atherosclerotic process. Mean titles of antibodies to parainfluenza virus and adenoviruses were similar in both groups of patients. Direct detection of viral DNA by polymerase chain reaction was carried out in samples of aortic wall taken during coronary artery bypass surgery with the use of primers for hemagglutinin of H1N1, H3N2 viruses. RNA of influenza virus was found in these samples. CONCLUSION: The presence of viral RNA in vascular atherosclerotic lesions could be indicative of possible pathogenetic role of influenza infection in progression of clinical course of atherosclerosis.

Antibodies, Viral↗
PubMed1999

[Platelet adhesion to collagen in whole blood: a simple and rapid quantitative method].

A simple, rapid, and easily reproducible method for quantitative assessment and graphic representation of platelet adhesion of whole blood specimens is proposed. It is based on registration (by means of impedance aggregometer) of changes in the module of complex resistance of an EDTA-stabilized blood specimen by collagen. The amplitude of the process initiated under such conditions directly depends on collagen concentration, weakly decreases if blood is incubated with high concentrations of acetylsalicylic acid (500 micromol/liter), and significantly decreases in the presence of RGD-containing peptides in a concentration of 20-40 micromol/liter). A relatively higher collagen adhesion capacity of blood platelets from coronary patients correlates with their high aggregation activity.

Collagen↗
PubMed1999

[Pathogenetic significance of cholesterol-containing immune complexes and lipid peroxidation in ischemic heart disease].

AIM: To ascertain a relationship between cholesterol content in circulating immune complexes (CIC) and plasm lipid peroxidation (LPO) in patients with ischemic heart disease (IHD). MATERIALS AND METHODS: Blood samples from 33 IHD patients 23 of which had a history of myocardial infarction and from 8 healthy subjects were examined for total cholesterol, high and low density lipoproteins cholesterol, CIC, the ability of blood serum to induce free radicals, superoxide dismutase. RESULTS: A statistically significant positive correlation was found between CIC cholesterol level and content of free radicals while a negative correlation existed between superoxide dismutase activity and high density lipoprotein cholesterol level in blood plasm of healthy individuals and patients with IHD. After myocardial infarction an inversion of the above parameters was seen as a result of disorders in both antioxidant and immune systems. CONCLUSION: The level of both LPO and CIC cholesterol, their interaction are important atherogenic factors in development of IHD.

Adult↗
PubMed1997

Antithrombotic and vasorelaxant properties of a novel synthetic RGD peptide containing nitric oxide.

We have developed a novel synthetic peptide containing both the antiadhesive Arg-Gly-Asp (RGD) amino acid sequence and a nitric oxide (NO) moiety well known for its vasorelaxant properties. The main objective of this study was to determine whether this hybrid molecule is concurrently effective with regard to antithrombotic and vasorelaxation actions. Studies of in vitro platelet adhesion and of in vivo platelet thrombus formation in the rat demonstrated that the RGD-NO peptide increased the antithrombotic characteristics of the RGD peptide alone. The RGD-NO peptide also caused relaxation of rat aortic rings, while the RGD peptide did not induce relaxation. These characteristics of Ac-RGDC-SNO suggest that this or similar compounds may have potential as effective antithrombotic agents in coronary and peripheral artery disorders.

Animals↗
PubMed1996

Platelet activation during provocation of coronary artery spasm by ergonovine and cold pressor testing in patients with angina pectoris.

The role of coronary spasm in variant angina is well established. We have studied the time course of platelet activation during Ergonivine provocation to determine one significance of platelet indices for spasm testing. The results showed that spontaneous platelet aggregates and beta-thromboglobulin levels in patients with coronary vasospasm were increased during provocation and that platelet activation during a positive Ergonivine test precede ECG changes and chest pain.

Adenosine Diphosphate↗
PubMed1996

[Some factors of atherosclerosis risk in obese youths].

A total of 215 obese youths aged from 15 to 20 years were studied for lipid and carbohydrate metabolism, blood pressure and hormonal factors that regulated them (the performance of the thyroid gland and zona fasciculata of the adrenal cortex). The majority of the examinees revealed such atherosclerotic risk factors as arterial hypertension, diabetic pattern of carbohydrate metabolism disorders and type IIB, IV and IIA atherogenic dislipoproteinemia. In patients with juvenile dispituitarism there was dysfunction of hypophyseoadrenal systems which probably was important in pathogenesis of lipid and carbohydrate disbolism and arterial hypertension in them.

Adolescent↗
PubMed1993

Antioxidative activity of high density lipoproteins in vivo.

The present study consists of experimental and clinical investigations. It was shown that a single intravenous injection of a large dose of human HDL3 (200 mg protein) to rabbits with induced hypercholesterolemia (plasma cholesterol 500-700 mg/dl) was accompanied by a significant elevation of plasma HDL and led to a decrease (P < 0.05) of conjugated dienes and trienes by 20-30% after 6 h. Conjugated dienes remained stable for 24 h after HDL administration. In the clinical investigations a weak but statistically significant negative correlation (r = 0.262; P = 0.006) between HDL cholesterol and the content of conjugated dienes in the plasma of a total group of healthy subjects and patients with coronary heart disease (CHD) was found. The data allowed us to conclude that, in addition to other antioxidative systems, HDL also take part in the protection of plasma lipids from peroxidation.

Animals↗
PubMed1993

[The effect of L-glutamic acid on the ADP-induced aggregation and Ca, Mg-ATpase activity of human thrombocytes].

In the study of L-glutaminic acid effects on human platelet functional activity it was established that 30-60-min treatment of platelet-rich plasma with glutamate in concentration 0.1-1.0 mM at 37 degrees C results in a marked platelet activation. The latter noticeably enhances ADP-induced aggregation persistent against antiaggregation adenosine concentrations. With increasing duration of the incubation a glutaminic acid minimal effective concentration lowers. Proaggregatory and anti-adenosine effects of L-glutaminic acid are inhibited by kainic acid. The experiments evidence that 30-min preincubation of platelet membranes with 1 mM L-glutaminic acid produces inhibition of cAMP-induced activation of Ca, Mg-ATPase returning the activity of the enzyme to baseline levels. No glutamate-related changes in calcium pump of platelets are reported.

Adenosine Diphosphate↗
PubMed1993

[The thrombocyte function of subjects with atherogenic hyperlipidemias during lovastatin treatment].

The effects of lovastatin on in vivo spontaneous and in vitro ADP-induced platelet aggregability were studied in the blood of 36 persons with primary hyperlipidemias (HLP) of Types IIIa and IIb. In addition to decreases in blood cholesterol levels by an average of 33% and the atherogenicity coefficient to the normal levels, there was an increase in spontaneous and/or ADP-induced platelet aggregability in the first 2-3 months of lovastatin therapy. Lovastatin-induced in anti- and proaggregatory potential in the platelet-vascular wall system towards of the latter and spontaneous intravascular platelet formation suggest that there is a higher risk for thromboembolic events in the examined patients with Type II HLP, especially if they have coronary heart disease, during early stages of the drug administration. Therefore, there are reasons for recommending that lovastatin should be given under the control of the platelet hemostatic system.

Adenosine Diphosphate↗
PubMed1993

Evidence of combined therapy of dyslipoproteinemia by HMG-CoA reductase inhibitors and "essential" phospholipids.

Platelets are involved in the initiation of atheromas and arterial thrombosis and thus may play a cardinal role in the pathogenesis of myocardial and cerebral infarction. In 18 patients with coronary artery disease and hypercholesterolemia resistant to low-lipid diet a 12 week treatment with lovastatin (HMG-CoA reductase inhibitor) leads to the reduction of total cholesterol, LDL-cholesterol and triglycerides but also to a marked increase of platelet activity. Lovastatin is an inactive lacton prodrug which must be enzymatically or chemically transformed to the active form. In in-vitro experiments, it was discovered that both chemically hydrolysed lovastatin and plasma containing lovastatin metabolites stimulate induced platelet aggregation in whole blood samples. "Essential" phospholipids (Lipostabil) added to the blood samples in concentrations according to those which are used clinically prevent this stimulation. This corresponds to data obtained earlier from Lipostabil-treated ischemic heart disease patients. Besides a lipid-lowering effect Lipostabil showed a 50% reduction of spontaneous aggregates in plasma, an increase of the susceptibility threshold to aggregation inducers and a decrease of the platelet aggregation amplitude in whole blood samples. Therefore, it would be promising to combine the therapy by lovastatin with "essential" phospholipids possessing a remarkable improving effect on the platelet function based on a molecular action independent of their moderate lipid-reducing action.

Adult↗
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↗