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Biomedical subjects

S A Gusev

Publications and source records attributed to S A Gusev.

At least 19 recordsLinked to original sources
PubMed1996

[A quantitative analysis of the regional organizational characteristics of the aortic endotheliocyte layer in normotensive and spontaneously hypertensive rats].

Using scanning electron microscopy and semiautomatic image analyser, regularities and quantitative changes were studied in endotheliocytes in three regions of thoracic aorta during ageing of normal and spontaneously hypertensive rats of the Kyoto-Wistar line. The data of morphometric analysis and the results of simulating endothelial cell monolayer changes, by means of construction of polyrow mosaics, suggest that the number of small endotheliocytes of normotensive rats in all aorta regions is lowered in the period from 2 to 10 months to increase then from 10 to 16 months. The endothelial cell monolayer changes occur as follows: the small endotheliocytes appear and then disappear, keeping their random distribution in the endothelial layer. Within the same period, in spontaneously hypertensive rats, the behavior of the endothelial layer in the region of intercostal arteria ostia and on the dorsal surface is similar to that in normal rats, being presumably associated with age changes. In hypertensive rats, on the ventral surface of the aorta, a relative number of small cells increases at the expense of small cell foci formation. Thus, the provided evidence points to a heterogeneity of responses of endothelial layers in different regions of the aorta on the constant elevation of pressure.

Aging↗
PubMed1992

[The characteristics of the absorption in the small intestine of 2 casein hydrolysates and of an equivalent amino acid mixture].

Using casein hydrolysates and the amino-acid mixture applied to mucosal or serosal surfaces, their effect on the transport of free glycine, glycine formed during glycyl glycine hydrolysis, and galactose, was studied in the small intestine. The data obtained suggest a mechanism of peptide transport in the enterocytes as well as a possibility of a regulatory effect of the peptides contained in casein hydrolysates on the transport of some basic nutrients.

Amino Acids↗
PubMed1991

[The hydrolases of the mucosal, submucosal and muscular layers of the small intestine and their functions].

Proceeding from the newly obtained evidence on the distribution of digestive enzymes in mucosal, submucosal and muscular layers of the small intestine in rats, a hypothesis has been formulated: in addition to the enterocyte enzyme complex forming the epithelial barrier, there seems to exist a postepithelial barrier formed by the enzymes localized in subepithelial structures. The efficiency of this second barrier was manifested by the study of the peptide hydrolysis and transport using everted intact and de-epithelialized intestinal sacs.

Animals↗
PubMed1991

[The detection of the cholesterol of the erythrocyte plasmalemma by using a latex marker].

Using a new specific cholesterol marker (SCM) and scanning electron microscopy, the distribution of cholesterol in the plasmalemma of rabbit and human erythrocytes was studied. Investigation of SCM linking with the erythrocyte membranes with different cholesterol/phospholipid indices shows that the increase of cholesterol/phospholipid index of the erythrocyte membrane correlates with the increase in the number of SCM particles on the erythrocyte surface.

Animals↗
PubMed1990

Localization of peptide hydrolysis in the enterocyte and the transport mechanisms of apical membrane.

1. The absence of the effect of anoxia on the hydrolysis rate of a number of dipeptides and one tripeptide by the intact and homogenized mucosa of the small intestine in different mammals (rat, mouse and guinea pig) has been demonstrated. 2. It has been shown that in rats anoxia inhibits intestinal transport both of free glycine and glycine formed during the hydrolysis of Gly-Leu, Leu-Gly, Gly-Pro but not Pro-Gly. 3. Data obtained using the anoxic criterion suggest that the systems of membrane hydrolysis of peptides with the subsequent absorption of released amino acids presents a dominant mechanism of protein assimilation under normal physiological conditions. 4. However, they do not exclude the possibility of the transport of peptides across the apical membrane of enterocytes.

Absorption↗
PubMed1990

[Study of the latex agglutination reaction using a light-scattering method].

Light scattering techniques as a method for monitoring latex agglutination test were under study. The model system, employed in the studies, consisted of a suspension containing polystyrene latex microspheres with tetanus antitoxin immobilized on them (carrier particles) and antitetanus serum (3000 IU). The studies helped define approaches to the choice of the optimal conditions for monitoring the latex agglutination test. Light scattering method has proved to be highly sensitive, its sensitivity essentially surpassing that of slide tests and permitting the detection of early agglutination stages.

Latex Fixation Tests↗
PubMed1990

[Morphological substantiation of selection of the method of surgical treatment of patients with prolapse of internal genital organs].

Morphology of uterine ligaments and the vaginal mucosa has been examined in 61 patients with uterine prolapse in order to provide guidelines for an optimum management with respect to tissue functional status. Specimens were obtained intraoperatively and examined in a usual microscope and a S-570 Hitachi scanning electron microscope (Japan). The study suggests that morphologic evaluation of the vaginal walls and uterine ligaments provides an exact measure of tissue status, offering an optimum choice of treatment in these patients.

Adult↗
PubMed1989

[A quantitative analysis of regional features in the structure of aortal endothelial cells in short-term hypertension].

The results of quantitative analysis of regional differences in the structure of thoracic aorta endotheliocytes in normal and hypertensive rats are presented. Scanning electron microscopy and semiautomatic image analyser were employed in studying the cellular structure in three regions of aorta endothelial layer: dorsal and ventral surfaces and region of the intercostal arterial ostia. The data obtained show that in cases of a short-duration hypertension the most pronounced are the alterations in endotheliocytes of the dorsal surface. Thus, the results confirm the heterogeneity of the aortic endothelium under normal conditions and demonstrate that differences in overlapping of neighbouring endotheliocytes is the cause of the observed alterations in cases of hypertension.

Animals↗
PubMed1989

[Identification of digitonin binding sites on the plasma membrane of the rabbit aorta endotheliocytes].

Specific reagents comprising digitonin bound to latex spheres were used as visual markers for the detection of cholesterol sites on the endothelial cell surface by scanning electron microscopy. The distribution of latex markers in the plasmolemma of the endothelial cells was investigated. These markers have strong bonds with the ligands. This interaction guarantees high specificity of binding between labeled markers and cellular membrane cholesterol.

Animals↗
PubMed1988

[Detection of the intercellular borders of the endothelium using scanning electron microscopy].

Three different approaches for studying aorta endothelial cells by scanning electron microscopy (SEM) were compared to expose cell border lines and surface shape simultaneously. Staining of aorta probes with silver nitrate leads to more specific silver deposits at cell junctions, but unsatisfactory image resolution obscures any detail of cell junctions and other fine structural features. Endothelium impregnated with tannin-osmium showed enhanced cell junction detail, but this method resulted in formation of presumably artificial structures. Osmium tetraoxide was most optimal for impregnation of aorta probes, as it exposed well cell border lines, excluded artifacts of tannin-osmium staining, provided a good image resolution in SEM, and allowed to analyse the ultrastructural features of cell surface.

Animals↗
PubMed1988

[Regional characteristics of the organization of the aortic endothelium (a quantitative analysis)].

By means of SEM-analysis in 110 microphotos (from 14 aortas of white rats) with the aim to estimate heteromorphism of the thoracic part endothelium, quantitative characteristics of endotheliocytes have been studied in the ventral and dorsal surfaces, and also around the ostia of the intercostal arteries. For the quantitative analysis organization of the lines of the interendotheliocyte borders is taken into account. Endotheliocytes around the ostium are more elongated but occupy less area and have less straight contours in comparison with cells in other regions; they have also greater variability. Essential differences in arranging the endothelial cells into the layer on the ventral and dorsal surfaces of the aorta are revealed.

Animals↗
PubMed1988

[The distribution of negative charges on the luminal surface of Descemet's endothelium].

The localization of anionic sites on the surface of corneal endothelium was investigated using colloidal nickel. The distribution of the binding sites of colloidal nickel along the cell surface was examined with the scanning electron microscope. The application a special detector of high sensitivity reflection allows to register a composed contrast determined by colloidal nickel. Colloidal nickel is bound with the surface of endothelium in areas of cell junctions only. A 1 X 10(-4)% sol. adrenaline injection into the anterior rabbit eye chamber in vivo changed the distribution of colloidal nickel. These findings demonstrate that colloidal nickel allows to mark the anionic sites on the cell surface for scanning electron microscopic studies.

Animals↗
PubMed1988

[Cholesterol in the plasmalemma of endotheliocytes in the normal aorta and in hypercholesterolemia (scanning electron microscopy research)].

Using a specific latex marker (SLM) and scanning electron microscopy, distribution of cholesterin in plasmolemma of endotheliocytes of the thoracic part of the rabbit aorta has been studied under normal conditions and at experimental atherosclerosis, as well as on the surface of liposomes and flat bilayer films. SLM reacts with a high specificity directly with cholesterin of the membrane. When studying microtopography of cholesterin, it is possible to distinguish microdomains with various density of distribution of SLM particles. Amount of SLM per 1 mcm2 of the artificial membrane surfaces grows at increase of the cholesterin-phospholipid (Ch/Phl) index of the membrane; Ch/Phl can bind with the membranes beginning only with the threshold value of the Ch/Phl index equal to 0.5. At hypercholesterolemia amount of SLM on the luminal surface of plasmolemma of the aortal endotheliocytes increases by 78%. Hence, at hypercholesterolemia in the luminal part of plasmolemma of the aortal endotheliocytes the Ch/Phl index increases; this should be taken into consideration, when observing mechanisms of reorganization of the endothelial cells layer at atherosclerosis.

Animals↗