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Biomedical subjects

W Ovtscharoff

Publications and source records attributed to W Ovtscharoff.

At least 55 records · Page 3Linked to original sources
PubMed1985

Distribution of negative charges of rat brain synaptosomes established by means of protamine-ferritin conjugate.

The negative electric charges on the synaptosomes from rat cerebral cortex were studied by means of protamine-ferritin conjugate. The synaptic vesicles in some synaptosomes were heavily labelled with the positively charged conjugate. The synaptosomal membranes including presynaptic and postsynaptic membranes were also stained but in a lesser degree. It was established that the major dense line and the intraperiod line of myelin contaminants were labelled, too.

Animals↗
PubMed1985

Mistletoe lectin I binding sites on the synaptosomes of the rat cerebral cortex.

By means of combined lectinological and immunological methods were demonstrated mistletoe lectin I binding sites on rat cerebral cortex synaptosomes. The mistletoe lectin I binds specifically D-galactose. Galactosyl residues were established on the junctional and nonjunctional synaptosomal membrane, on the synaptic vesicles, mitochondria and on myelin contamination. The relative number of mistletoe lectin I receptors per unit area of synaptosomal membrane was calculated.

Animals↗
PubMed1985

Cardiovascular system of the conjoined twins.

The cardiovascular system of the dicephalus (2 spines, one pelvis) conjoined twins is being described. The heart consists of 2 atria and 3 ventricles. Various malformations are evident in the layout systematic and pulmonary circulation. The vascular system can be divided into 3 zones: an upper one--with an almost symmetrical duplication, a middle one--with an atypical pattern, and a lower one--with a normal pattern.

Cardiovascular Abnormalities↗
PubMed1985

Internal organs of the conjoined twins.

Described are the alimentary system, the respiratory system, the urogenital system and the endocrine glands of conjoined female twins. There were found to be present 2 esophagi, 2 stomachs, 2 duodeni, 2 pancreas and one large liver. The intestine is unique from the region of the jejunum to it's end. There were found to be present 2 tracheae and 4 lungs. The urogenital system appeared to be normal. A single deviation was noted with respect to the endocrine glands, in particular, the right adrenal gland had an additional part which entered the thorax through a cleft in the diaphragm.

Adrenal Glands↗
PubMed1984

Demonstration of electron-dense material in clear synaptic vesicles using cationic ferrocenyl compounds.

Electron-dense material in clear synaptic vesicles in rat cerebral cortex and neuromuscular junctions of frog cutaneous pectoris muscle was demonstrated by using ferrocenyl cationics. Electron-dense spots were usually attached to the inner surface of the vesicular membrane. Control experiments (treatment with Triton X-100 or cetylpyridinium chloride; enzyme digestion with trypsin, hyaluronidase, neuraminidase, sulfatase and beta-glucuronidase) suggested that the electron-dense material is a glycoprotein.

Animals↗
PubMed1984

Localization of lectin binding sites on the rat intestinal microvillous membrane.

The distribution of peroxidase labeled Asparagus Pea Lectin and Soybean Agglutinin on the rat intestinal microvillous membrane was studied. Controls were carried out to determine the reaction specifity . Some analogy was established between the distribution of the binding sites of both lectins. The reaction product was deposited mainly on the microvillous membrane of the crypt cells and the cells from the lower part of the intestinal villi, and to a lesser extent on the upper part of the latter. Electron dense material was seen on the upper part and chiefly on the tip of the microvilli. From the results of this study and on the basis of data from our previous studies it was proposed, that changes in the carbohydrate content of the microvillous membrane appear during the differentiation and maturation of the intestinal cells.

Animals↗
PubMed1984

Peculiarities of the bones, muscles, and nervous system of the conjoined twins.

The peculiarities of the skeletal, muscular, and nervous systems of conjoined female twins (2 spines, one pelvis) is described judging from the examination of the 2 skulls, 2 vertebral columns, shoulder girdle of the intermediate connection between the trunks, deep muscles of the back, 2 separate central nervous systems, lack of changes in the muscles, of the anterior aspect of the thorax and anterolateral muscles of the abdomen; from what we have observed it is suggested that this is a case of uniovary twins whose separation began in the superior dorsal side but was incomplete in the ventral inferior parts. It is possible that this arose from accidents of fusion or fission of embryos.

Abnormalities, Multiple↗
PubMed1981

Concanavalin A binding sites on the intestinal microvillus membrane of rat.

Concanavalin A binding sites on the intestinal microvillus membrane have been studied by means of Concanavalin A-horseradish peroxidase method. Several controls were carried out to demonstrate the specifity of this technique. Reaction product on the microvillus membrane of columnar cells on the upper bigger part of intestinal villi was found, while on the intestinal cells from the base of the villi and undifferentiated crypt cells no electron dense material was established. The results of the suggested method were discussed in relation with the literature data.

Animals↗
PubMed1980

Ruthenium red staining material in Herbst and Grandry sensory corpuscles.

The penetration and distribution of ruthenium red into Herbst and Grandry sensory corpuscles has been investigated. Ruthenium red positive substances have been localized in all intercellular spaces including the collagen fibrils, basement membranes and predominately the outer leaflet of the plasmalemmae including the axolemma. Some of the numerous pinocytotic and coated vesicles of the receptor cell layers have been heavily loaded with the dye. Sometimes, the intracytoplasmic and intraaxoplasmic penetration of ruthenium red has been observed. In these cases, the dye deposits have been restricted to the elements of smooth endoplasmic reticulum, mitochondria and microtubules.

Animals↗
PubMed1979

Synaptic organization of the medial acessory olivary nucleus of the cat.

Light microscopically the morphological characteristic of neurons and ultrastructurally the synaptic organization of medial accessory olivary nucleus of cat was studied. Different types of chemically mediated as well as electric synapses were observed. The terminal boutons contain mainly clear synaptic vesicles, but small and large dense core vesicles are also available. In the neuropil of the nucleus characteristic glomeruli with central dendritic core were establish. The dendritic profiles were connected with numerous gap junctions and attachment plaques. The apposition without any synaptic specializations in a large area of the cell membrane of adjacent neurons was also observed. In some cases oval structures with size 450--650 A which we called submembraneous dense bodies were established under one of the apposite membranes.

Accessory Nerve↗
PubMed1978

Visualization of proteinaceous granules in the clear synaptic vesicles.

A method for demonstration of electron-dense particles within clear synaptic vesicles from various areas of the CNS as well as from neuromuscular junctions of rat is described. Electron-dense granules of 70-250 A were visible in the center of the synaptic vesicles, or in some cases excentrically situated and bound to the vesicular membrane. Digestion with proteolytic enzymes lead to a negative reaction, whereas treatment with hyaluronidase and neuraminidase, as well as the lipid extraction had no effect. Based on the obtained data, it may be assumed that this method manifests the proteinaceous structures.

Animals↗
PubMed1978

Ultrastructural changes in the anterior horn synapses of rat spinal cord under different locomotor conditions.

Ultrastructural changes in axodendritic synapses of the spinal cord ventral horn are studied in rats subjected to different locomotor conditions: immobilization, control and physical loading. Enhanced motor activity results in a reduction of the number of synaptic vesicles in the axon terminal, as well as flattening and diminution of their size. Other changes correlated with the different motor regimes are likewise established in the number of terminal ending's mitochondria, in "active zones", in subjunctional dense bodies, and in the bouton area. Data are treated by means of variation analysis. The significance of differences is established by "T"-criterion.

Animals↗
PubMed1977

Cytochemical localization of adenosine triphosphatase and thiamine pyrophosphatase in the synapases of rat's cerebral cortex.

Ultrastructural distribution of adenosine triphosphatase and thiamine pyrophosphatase in synapses of rat's cerebral cortex was studied. Adenosine triphosphatase activity in some synaptic vesicles and mitochondria, on pre- and postsynaptic membranes, as well as in the postsynaptic thickening was established. The reaction specificity was proved by means of some controls: various concentrations of ouabain, NaF, NiCl2, cysteine, substrate free medium and non-specific substrates - cocarboxylase and beta-glycerophosphate. At the thiamine pyrophatase reaction, the enzyme positive product was found on the membrane of some clear synaptic vesicles, on the singl sacs of smooth endoplasmic reticulum in the axon terminal, and bouton cell membrane. Substrate free medium, addition of cystein and substitution of orininal substrate with adenosine triphosphate and beta-glycerophosphate as controls were used. The fine structure localization of both enzymes in synaptic structures suggests their important role in the synaptic function.

Adenosine Triphosphatases↗
PubMed1977

Ultrastructural localization of choline acetyltransferase in the CNS of rat.

The ultrastructural localization of choline acetyltransferase in various regions of rat's CNS is studied. It is established that the reaction product is located in some structures of the neuronal perikarya--on the outer surface of the rough endoplasmic reticulum sacs, along the vesicular profiles and in the mitochondria. Electron dense material is found in the axon terminal as well as, where enzyme activity is detected in the cytoplasm, on the membrane of spherical and flat synaptic vesicles and in the mitochondria. These findings, the control results and literature data are discussed.

Animals↗