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Biomedical subjects

A N Orekhov

Publications and source records attributed to A N Orekhov.

At least 199 records · Page 11Linked to original sources
PubMed1983

[Effect of dibutyryl-cAMP on the cholesterol ester content in human atherosclerotic aorta cells].

Dibutyrly-cAMP (db-cAMP) reduces the content of cholesterol esters in intimal cells obtained from atherosclerotic areas of human aorta. This effect depends on the nucleotide concentration. Db-cAMP has no effect on the content of cholesterol esters in the cells obtained from unaffected aortic areas. It can be assumed that cAMP derivatives and agents that give rise to the increased cAMP level in the cells may impede the development of the atherosclerotic manifestation such as lipoidosis.

Adult↗
PubMed1983

[Immunomorphological study of the localization of types I, III, IV and V collagen in a primary culture of human aortic cells].

Fibrosis is the most important manifestation of human vascular atherosclerosis. Primary culture of human aortic cells makes it possible to study some manifestations of fibrosis in vitro. Indirect immunofluorescence has shown that primary culture cells contain intracellular antigens to all the antibodies used but that only type I collagen forms extracellular matrix in culture. Modulation of the cultivation conditions does not lead to the appearance on the cell surface of other type collagens. It is assumed that in primary culture, human aortic cells synthesize the same collagen types as those synthesized in vitro. This circumstance might enable using such a culture as model for studying the mechanisms of fibrosis during atherosclerosis.

Aorta↗
PubMed1983

Stellate cells in the intima of human aorta. Application of alkaline dissociation method in the analysis of the vessel wall cellular content.

Cells isolated from the fixed human aorta by alkaline dissociation have been studied. Cellular content of normal and atherosclerotic intima is described. Special attention is given to stellate cells that were found in large quantities in all analyzed samples. It is found that in the fatty streak stellate cells are localized nearest to the endothelium but they have no definite localization in the fibrous plaque. In unaffected intima, stellate cells are diffusely localized, and often prevail over other cell types.

Adult↗
PubMed1983

[3H-thymidine incorporation into human aorta cells in primary culture. An autoradiographic study].

Primary cell culture has been obtained from intima and media of unaffected zones of human aorta and from atherosclerotic lesions (fatty infiltration, fatty streaks, atherosclerotic plaques). Cellular polymorphism was found in these cultures. Four morphological types of aortic cells are described: elongated, asymmetric, polygonal, and stellate cells. These cell types also differed in their proliferative activity. On the 7th day of culturing, polygonal cells do not incorporate 3H-thymidine; the thymidine index of other three cell types was similar. The thymidine index of medial cells was higher than that of intimal ones.

Aorta↗
PubMed1983

Cell proliferation in normal and atherosclerotic human aorta. I. Flow cytofluorometric determination of cellular deoxyribonucleic acid content.

By enzymatic dispersion cells were isolated from intimal and medial layers of healthy and atherosclerotic human aorta. The analysis of cell distribution according to DNA content was made using flow cytofluorometry. It was found that intimal and medial cell populations are heterogeneous with respect to DNA content and include 2 n and 4 n DNA populations. The 4 n cell content may amount to 19% of cell population. As a rule, the percentage of 4 n cells in intima is lower than in media. In atherosclerotic lesions their content is lower than in uninvolved areas. The 4 n-DNA population includes mono- and binuclear cells.

Adult↗
PubMed1983

Cell proliferation in normal and atherosclerotic human aorta. II. Autoradiographic observation on deoxyribonucleic acid synthesis in primary cell culture.

Proliferative potentiality of cells from atherosclerotic and nonatherosclerotic human aorta was evaluated in culture by the incorporation of radioactive thymidine. Thymidine index was determined autoradiographically in primary cultures of intimal and medial cells isolated from zones of fatty infiltration, fatty streaks, atherosclerotic plaques, and uninvolved areas. The thymidine index in medial cultures was higher than in the intimal ones and was unrelated to the type of lesion. In intimal cultures obtained from zones of fatty infiltration and fatty streaks the thymidine index exceeded the normal value by 4.5- and 3-fold, respectively. In cell cultures of the plaque and unaffected intima the thymidine index was the same.

Adult↗
PubMed1982

[RNA content of cells isolated from normal and arteriosclerotic human aorta].

Cells from the intimal and medial layers of the normal and atherosclerotic human aortas were isolated by enzymatic dispersion. The isolated cells were stained in suspension by intravital staining with acridine orange as fluorescent stain for nucleic acids. The intensity of red fluorescence in each cell corresponding to the RNA content was measured and recorded by flow cytofluorometer. Cell distribution as measured by two parameters: red fluorescence (the RNA content) and light scatter (the cell size) revealed two cell subpopulations as regards cell populations from the intima and media, namely A cells with low RNA content and B cells with higher RNA content. The relative cell number in subpopulation A isolated from the intima with atherosclerotic lesions was greater than that isolated from the normal intima.

Adult↗
PubMed1982

[Detection of 2 cell subpopulations each differing in incorporating low-density lipoproteins in an atherosclerotic plaque from the human aorta].

Cells were isolated by enzyme dispersion of plaques (N-cells) and unaffected areas (A-cells) of human aorta. The capacity of both types of cells to uptake LDL was compared in 7-day primary cultures. Also, these populations were analyzed to discover subpopulations with different types of LDL uptake. RITC-labeled LDL was used for the purpose. A fluorescent-activated cell sorter (FACS-II, Becton and Dickinson, USA) was used to measure the RITC-LDL content and to sort out cell subpopulations. It was shown that the A-cell population consists of two subpopulations with a different type of RITC-LDL uptake. Cells overloaded with lipid inclusions uptake RITC-LDL nonspecifically, while cells without lipid inclusions mostly uptake RITC-LDL through specific receptors.

Adult↗
PubMed1982

[Lipid metabolism in cells of human atherosclerotic aorta. Study in the primary culture].

Incorporation of 3H-acetate into the main classes of lipids in human aorta cells was studied. It was demonstrated that fractions of intimal and medial cell lipids in primary cultures of unaffected vascular areas were different as to the accumulation of the labeled precursor. Intimal cells isolated from lipid streaks and atherosclerotic plaques accumulated the labeled acetate in lipids 2.5-fold more effectively. The greatest changes in the level of 3H-acetate incorporation were registered in phospholipid fractions and cholesterol esters. Medial cells from the media underlying atherosclerotic lesions were shown to have an enhanced ability to include the label into neutral lipids. It is assumed that the changes in intracellular lipid metabolism may account for the increased lipid content in human atherosclerotic aorta.

Aorta↗
PubMed1981

[Polymorphism of human aortic cells in culture].

A method is suggested for isolation and cultivation of cells from the intima and media of human aorta. In primary cell cultures obtained by this method, cell polymorphism has been found. Four main morphologic types of cells have been described: prolonged, asymmetric, polygonal and star-shaped. Polygonal and star-shaped cells have been found only in the cell cultures taken from intact intima. Prolonged and asymmetric cells have been found in all the cultures without exception. The proportion of the prolonged and asymmetric cells in the cultures obtained from intact aorta wall and from lipofibrous plaques is approximately similar and makes 3 : 1. In the cultures obtained from the sites of a vessel with lipid stripes the part of asymmetric cells exceeds 50%.

Adult↗
PubMed1978

[Post-radiation disorders in the cyclic AMP system of mouse spleen and thymus lymphoid cells].

Early alterations in the enzyme activities controlling cyclic adenosine-3',5'-monophosphate (cAMP) metabolism after the irradiation (800 rad) of mice were found in the lymphoid cells of the spleen and thymus. Postradiation disturbances in these activities' ration induced alterations in cAMP steady-state concentrations in the cell. It was also demonstrated that irradiation reduced lymphoid cell ability to accumulate cAMP in response to isoproterenol administration.

Adenylyl Cyclases↗
PubMedDate not supplied

Effects of garlic on atherosclerosis.

This review discusses the use of garlic and garlic preparations as agents for prevention and treatment of atherosclerosis and atherosclerosis-related diseases. Garlic indirectly effects atherosclerosis by reduction of hyperlipidemia, hypertension, and probably diabetes mellitus and prevents thrombus formation. In addition, in animal models, garlic causes direct antiatherogenic (preventive) and antiatherosclerotic (causing regression) effects at the level of artery wall. Garlic's direct effect on atherosclerosis may be explained by its capacity to reduce lipid content in arterial cells and to prevent intracellular lipid accumulation. This effect, in turn, is accompanied by other atherosclerotic manifestations, i.e., stimulation of cell proliferation and extracellular matrix synthesis. Clinical trials are currently being carried out to reveal the possible effect of garlic therapy on human atherosclerosis. Positive results of these trials may open a new era in the use of garlic for prevention and treatment of many atherosclerosis-related diseases.

Animals↗
PubMedDate not supplied

Autoantibodies against modified low density lipoprotein. Nonlipid factor of blood plasma that stimulates foam cell formation.

The blood serum of patients with coronary atherosclerosis possesses an ability to induce the accumulation of cellular lipids in primary cultures of human aortic intimal cells. Factors responsible for this property of the atherosclerotic patients' sera are represented by modified (desialylated) low density lipoprotein (LDL) and a nonlipid factor interacting with LDL. It was assumed that the nonlipid factor was antibodies against LDL. Total immunoglobulin G (IgG) fraction was isolated from the sera of atherosclerotic patients, and IgGs interacting with LDL (anti-LDL) were then purified by affinity chromatography on a sorbent with immobilized LDL. From the sera of patients, a 30-fold greater amount of anti-LDL has been isolated than from the sera of healthy donors. The affinity constant of anti-LDL to the lipoprotein obtained from the blood of healthy donors was 2 x 10(7) M-1. The affinity of anti-LDL to the lipoprotein from the blood of atherosclerotic patients, as well as to LDL desialylated in vitro with neuraminidase, was much higher. Anti-LDL increased the uptake of LDL by cultured aortic cells by approximately 2.5-fold and substantially increased intracellular lipid accumulation. The obtained data suggest that autoantibodies against LDL are an essential factor of blood plasma responsible for its atherogenic potential.

Adult↗
PubMedDate not supplied

[The identification of pericyte-like cells in the subendothelium of human blood vessels].

We identified pericyte-like cells in various regions of human vascular bed using 3G5 monoclonal antibodies against brain capillary pericytes' surface antigen. Pericyte-like cells were revealed in the subendothelial layer of the arterioles, venules, brain microvascular bed and in vasa vasorum adventitia. In arteries and veins of small, medium and large caliber pericyte-like cells were found in intimal subendothelial space. Pericyte-like cells form subendothelial network and may play an important role in physiological processes of vascular wall function.

Adult↗