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Biomedical subjects

A S Kuznetsov

Publications and source records attributed to A S Kuznetsov.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

[Oxidation of low density lipoproteins in the presence of silica gel treated with fullerene].

This study estimated the effects of low density lipoprotein (LDL) oxidation in the presence of fullerene silicagel in comparison with ions of Cu+2 in the wide region of oxidation times and reagent concentrations. Investigation is directed to reveal the reagent parameters, that promote to increase the oxidation rate of the LDL solution. It revealed only qualitative coincidence of the LDL oxidation kinetics in the presence as Cu+2 as fullerene, that indicated on the identity of the oxidation mechanism in both cases. At the same time the revealed quantitative difference between the oxidation process parameters are interpreted in the terms of oxidation potential and the electron affinity that characterize the reagent activity in the reaction accompanied by the electron transfer. The good correlation between above mentioned parameters and the oxidation rate of the aqueous LDL solution is observed: its increasing takes place at the increase of the electron affinity or at the decrease of the oxidation potential.

Carbon↗
PubMedDate not supplied

[Effectiveness and mechanism of action of a new plant complex drug in nonspecific inflammatory processes in the bronchopulmonary system].

The elixir Bronchofit is an aqueous-alcoholic extract from 7 kinds of plants. It is a balanced compound, rich in biologically active substances including essential oils and flavonoids, possessing a wide spectrum of pharmacological activity. On the model of frog's palate the elixir enhanced the transport function of the ciliated epithelium. On the model "karragenin edema" bronchofit showed a marked anti-inflammatory activity. A noticeable therapeutic effect was registered in rats with induced bronchopulmonary inflammation. Bronchial secretion contained reduced content of glycosaminoglycans while bronchial lavage did of histamine. Also, bronchofit demonstrated a prominent antioxidative activity, an antibacterial action in relation to Str. pyogenes and Bac. cereus. By a total complex of the activities bronchofit is a promising medicine against bronchopulmonary inflammation.

Animals↗
PubMedDate not supplied

[Mathematical modelling of charge properties of protein molecules].

A procedure of theoretical determination of the dependence of protein molecule charge on the medium pH has been developed. The suggested procedure allows calculating the protein pI value, the molecule charge at the definite pH value, as well as the corresponding values for the protein molecule. Calculations for insulin, apo A-I and apo A-II molecules have been carried out. Calculated pI values are equal to 5.25, 5.64 and 4.86, respectively. A comparison of the theoretical curves and experimental data allows obtaining information of the molecule structure. Carboxyl groups with abnormally high pK values are discovered, that, probably, indicates to the direct interaction of two COOH-groups. A supposition is made on the most probable arrangement of the functional fragments in apo A-I and apo A-II molecules.

Apolipoprotein A-I↗
PubMedDate not supplied

[Stomach mucosa prostaglandins in liver cirrhosis].

Distinct decrease in content of prostaglandins PGE, PGF2 alpha and 6-keto-PGF1 alpha was detected in biopsy material, using radioimmunoassay, from gastric mucosal membrane of patients with liver tissue cirrhosis complicated and not complicated by ulcerous disease of stomach or duodenum which correlated with a decrease in secretion of gastric juice (basal and histamine-stimulated secretion). These data suggest considerable impairments of endogenous biosynthesis of prostaglandins in gastric mucosal membrane under conditions of liver tissue cirrhosis, which are of importance in development of ulcerous disease in these patients.

Duodenal Ulcer↗
PubMedDate not supplied

The charge and atherogenicity of low density lipoproteins.

It is concluded on the basis of literature data, that apolipoprotein B-100 is the most high-molecular, hydrophobic, and positive charged protein compared to the other apoproteins of the plasma lipoproteins. Low density lipoproteins of healthy subjects, mainly containing apo B-100, have little heterogeneity on both charge and isoelectric point, in spite of heterogeneity on sizes and apolipoprotein composition. The reason of formation of subfraction with elevated negative charge is the damage with the free radicals and/or aldehydes. The reason of formation of more cationized subfraction is unclear. LDL charge changes are noted in some diseases and syndromes (ischemic heart diseases, familial hyper-alpha-lipoproteinemia, Tangier disease, X-bound ichthyosis and, possibly, others). Some IHD patients treatment with antioxidants leads to the disappearance of negative charged LDL subfraction, that shows participation of peroxidation products in their formation. Electrical characteristics of LDL of tissue fluids and of aorta wall differ essentially from those of the same class plasma lipoproteins. Lipid peroxidation and influences of several enzymes play the main role in these differences.

Apolipoproteins↗
PubMedDate not supplied

[Glycosaminoglycans in the makeup of the lipid-protein complexes of the human aorta].

Lipoprotein complexes were studied in intact parts of human aorta as well as in areas of aorta impaired with atherosclerosis. The arterial walls contained particles, which were similar to pre-beta and beta-lipoproteins as evidenced by immunological properties and by size. At the same time, lipoproteins of the vascular walls differed distinctly from those of blood serum because these former lipoproteins possesed altered electrophoretic mobilities in acetyl cellulose, contained glycosamineglycans, exhibited lower rate of flotation in salt-free solution as compared with the salt-containing solution under conditions of analytical ultracentrifugation. The data obtained suggest that the lipoproteins formed complexes with glycosamineglucans in vascular walls.

Adolescent↗
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[Study of lipoprotein changes in the vessel wall by ultracentrifugation of aortic extracts in discontinuous density gradients].

As shown by stepwise density gradient ultracentrifugation, atherogenic lipoproteins pentrating into aorta wall, underwent conversions, which were accompanied by alterations in their hydratation density. The data obtained suggest that complex formation of lipoproteins with components of connective tissue matrix is one of important steps responsible for conversion of atherogenic lipoproteins in vessel wall.

Aged↗
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[Complexes of apo-B-containing lipoproteins and glycosaminoglycans with a density greater than 1.063 gML in the human aorta].

Interaction of lipoproteins of very low and low density with glycosaminoglycans was studied in vitro. Using analytical and preparative ultracentrifugation the complexes formed were shown to possess a density above 1.063 g/ml. Similar complexes were identified in extracts of human aorta. The formation of the complexes was stimulated in atherosclerotic impairments of aorta.

Animals↗
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[Properties of plasma low density lipoproteins in patients with hypertriglyceridemia and ischemic heart disease].

It has been shown that low-density plasma lipoproteins in patients with ischemic heart disease and hypertriglyceridemia are heavier in density, smaller in size, more negatively charged and more inclined to peroxide modification and aggregation than in healthy persons. The protein in the composition of such lipoproteins deviates towards the water phase, which may result in the masking of the domen, recognized by the BE-receptor and may lead to hyperlipidemia of a retaining character.

Chemical Phenomena↗
PubMedDate not supplied

[Peroxide modification of low density lipoproteins in ischemic heart disease].

It is shown that the LDL peroxide lipid products level is 1.6-4 times higher in patients with the ischemic heart diseases (IHD) than in normal subjects. At the same time the LDL uptake by macrophages was identical in case of normal subjects and of IHD patients. It is suggested that the LDL premodification in the blood flow in the IHD patients promotes the further modification of LDL particles after their penetration into the vessel wall.

Coronary Disease↗
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[Protein conformation and localization in low density lipoproteins in health and in ischemic heart disease].

The study has shown that the ratio of elements in the secondary structure of LDL protein from patients with the coronary heart disease from health subjects is similar. However LDL protein is displaced by 0.5 nm towards the water phase in patients with CHD comparing with healthy subjects. It is likely that such differences are a result of the lower stability of LDL protein in CHD. It is supposed that the damage of lipoprotein particles (premodification) in CHD becomes atherogenic in the vessel wall after the action of additional factors.

Circular Dichroism↗
PubMedDate not supplied

[Effect of the catalytic subunit of cAMP-dependent protein kinase on the electrical activity of the rat heart in isadrine myocarditis].

The content of cAMP in the rat heart under neoepinephrine myocarditis does not differ from the control values and less increases relative to the control at the adrenalin concentrations of 5 X 10(-5) and 5 X 10(-4) M in the in vitro experiments (control: myocardium of healthy animals). Under these conditions dissociation of holoenzyme of cAMP-dependent protein kinase is disturbed in the presence of endogene-developed nucleotide and the phosphorylating activity decreases, respectively. The injection of the catalytic subunit of cAMP-dependent protein kinase encapsulated into neutral liposomes increases the duration of the myocarditis action potential for animals with the metabolic myocardial insufficiency.

Action Potentials↗