Search PubMed⌕ Search

Biomedical subjects

S A Gusev

Publications and source records attributed to S A Gusev.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1988

[Scanning electron microscopy of injected replicas in the study of the vascular system of the liver in mice and rats].

Three-dimensional organization of the liver vascular bed in (C57B1/6 X CBA)F1 mice and rats was examined by scanning electron microscopy of injection replicas. The data have been obtained on the character of branching, diameter of injection replicas in arterial and venous vasculature and different types of microvascular surface relief, depending on their location in the vascular bed.

Animals↗
PubMed1988

[Age-related changes in the ultrastructural organization of the human gingival epithelium].

By means of transmissive and scanning electron microscopy 103 gingival bioptates in practically healthy persons at the age of 18-80 years have been studied. At ageing essential changes take place in all structural elements of the epithelium. The basal membrane is intermittent and loose. In cytoplasm of the cells of the basal layer epithelium the amount of microfilaments increases essentially, and as a result it becomes electron opaque. Tonofibrillar fasciculi of the spinous layer cells are fragmented, their contours are indistinct. In cytoplasm of the granular layer cells amount of keratohyalin granules increases, their size becomes large and their typical form is lost. In cytoplasm of the basal, spinous and granular layer cells the amount of organells decreases. Mitochondria acquire the appearance of electron translucent cavities with discomplexic, and sometimes, destroyed cristae. Rather great changes occur in intercellular interrelations. In all the layers some intercellular spaces are widen, in the spaces formed isolated desmosomes and other debries of cellular structures are formed. Sharp changes of microrelief of the granular layer epitheliocytes are observed. The ultrastructural rearrangements of epitheliocytes, revealed in the human gingiva, demonstrate certain disturbances in keratinization processes, in mechanical firmness, as well as in barrier function of the epithelial layer.

Adolescent↗
PubMed1983

[Pathogenesis of cardiovascular disorders in acute experimental arterial obstruction].

Agents producing toxic myocardial effects are shown to appear in systemic blood flow as a result of acute occlusion of aortal trifurcation with subsequent recovery of blood flow in the limbs. The most pronounced effect was noted following blood infusion in dogs whose ischemia of the limbs had lasted for nine hours, instead of twelve, which must be due to specific features of circulation recovery in the ischemic area.

Acute Disease↗
PubMed1981

[Scanning electron microscopy of injection replicas of the cardiac microvessels].

The paper concerns three-dimensional study of the organization of the subepicardial network of the blood and lymphatic microvessels of the heart with the aid of scanning electron microscopy of the injected replicas. It is established that the arterioles have regular orientation of the imprints of the nucleus-containing zone of endotheliocytes. The capillaries belonging to the subepicardial network form a thick mesh and are strictly oriented along the muscular bundles. There is no characteristic relief on the surface of the capillaries. The study of the relief of the post-capillary venules made it possible to record different orientation of the imprints of the nuclei-containing zones of endotheliocytes on their surface. The study of structure of "leaks" formed as a result of leaking of resin from the venular segments of the bed enabled one to elicit their passage into the lymphatic capillaries. The latter are represented by flattened tubes, placed over the blood vessels.

Animals↗
PubMed1980

[Characteristics of the ultrastructural organization of endothelial cells in cardiac and omental blood capillaries based on cryofractographic data].

Using cryofractography, endotheliocytes of heart and omentum blood capillaries were studied, different patterns of distribution of membranous particles being observed of the "P" and "E" faces of the fracture plans of endothelial cell cytomembranes. Three types of distribution of micropinocytotic vesicles can be distinguished: the linear, hexagonal, and the clusteral type. The number of micropinocytotic vesicles was sharply reduced near the region of intercellular contacts. On the fracture plan, attached pinocytotic vesicles look like "craters" on the "E" face, and like circumvallatue papillae on the "P" face. Cell membranes, making intercellular contacts, have a network structure consisting of ridges on the "P" face and of grooves on the "E" face. Such a molecular membrane organization is discussed from the standpoint of modern concepts of the receptor--cytosceletal complex. It is supposed that this complex may control processes of transendothelial mass--transfer.

Animals↗
PubMed1980

[Action of histamine on the aortic endothelium].

Changes of the shape and surface of aortal endotheliocytes under the effect of histamine were studied by scanning electron microscopy. Incubation of fragments of the aorta in a histamine solution for 1 min results in changes of the nucleus-containing zone of some portion of the endotheliocytes into a spindle shape. The surface of the peripheral zone was characterized by the presence of spherical swellings. In some parts of the marginal zones of the cells there were numerous stomata of various sizes. Incubation of aorta for 5 min resulted in considerable alterations in the endotheliocyte stereoultrastructure. The nucleus- containing zones strongly protruded into the lumen. The cells became spherical. The peripheral zone was perforated by numerous stomata. The cell edges separated markedly at contact sites. The results suggest that the mechanism of the observed changes in the shape and surface of the cells may be associated with activation of the cytoskeletic complex (microtubules, microfilaments) under the effect of histamine.

Animals↗
PubMed1979

Mesothelial stomata overlying omental milky spots: scanning electron microscopic study.

The presence in the rat omentum of intercellular pores (the classical stomata of von Recklinghausen) between the mesothelial cells overlying aggregates of lymphoreticular cells (the classical milky spots of Ranvier) and the apparent migration of lymphocytes through these stomata were recorded for the first time by scanning electron microscopy. Previous studies on passage of cells across the peritoneum and omentum used experimentally administered cells, while in the present study no cells were administered to the rats and their own lymphocytes were observed in situ. The possible role of lymphocytes in the peritoneal cavity is also briefly discussed.

Animals↗
PubMed1979

[Production of injection replicas of microvessels for scanning electron microscopy using resin "PN-8"].

A method for obtaining injection replications of microvessels for scanning electron microscopy using nonsaturated polyether resin PH-8 is described. Possible applications of the method in question to study microcirculatory bed are discussed. With resine PH-8 it is possible to obtain complete and detailed replications which give information on three-dimensional organization both of the microcirculatory bed and of the vascular microrelief peculiarities.

Blood Vessels↗
PubMed1975

[Study of the rat parotid blood capillaries during a 3-hour feeding cycle].

Regularities attending the change in the lumen diameter and the area of the endothelial cells were studied in the capillaries of the rat parotid gland during the secretory cycle under conditions of circulatory ischemia. The mean lumen diameter and the area of endothelial cells failed to change during the secretory cycle and during the occlusion of the carotid artery. It is thus supposed that enhanced capillary blood flow during the discharge of saliva could be explained by the growing number of the functioning capillaries.

Animals↗
PubMedDate not supplied

[Intracranial cavernous angiomas: ultrastructural and immunochemical study].

43 brain cavernous angiomas (CA) were clinically and morphologically studied. The presence of smooth muscles and endotheliocytes in the trabeculae was confirmed. The sources of blood supply and the nature of medullary changes at the CA periphery were clarified. The hypothesis of CA hormonal dependence has been rejected.

Adolescent↗