Biomedical subjects

W Ovtscharoff

Publications and source records attributed to W Ovtscharoff.

65 records · Page 4Linked to original sources

PubMed1976

Ultrastructural changes in satellite cells after denervation and reinnervation of skeletal muscles.

Changes taking place in the satellite cells after denervation and reinnervation of skeletal muscles are studied. A certain degree of similarity and synchrony of the changes occurring in these cells and in the muscle fibers is established during the degenerative and regenerative processes. Formation of new satellite cells and fusion of the same with muscle cells is not observed. These findings are explained by the fact that postdenervation changes in the skeletal muscles are not so heavy as in their direct lesion when, according to literature data, the satellite cells participate directly in the reparative process.

Animals↗

PubMed1975

A method for demonstration of synaptic densities in CNS.

The synaptic densities in rat CNS were demonstrated using an alcohol solution of uranyl acetate at pH 5.0-6.0 of unosmicated material. A number of procedures were performed to establish the chemical characteristics of the structures stained by the method described.

Animals↗

PubMed1975

Cytochemistry and morphology of synaptic structures in the cerebral cortex of rat.

Studies have been carried out on the synapses in the cerebral cortex of rat by using impregnation with ethanolic solution of phosphotungstic acid, contrast staining with ruthenium red and impregnation with bismuth iodide, with or without subsequent uranyl acetate and lead citrate staining. It has been established that dense projections are adequately visualized with methods demonstrating basic chemical groups (phosphotungstic acid and bismuth iodide), whereas the synaptic vesicles are stained by techniques demonstrating acid chemical groups (ruthenium red and uranyl acetate and lead citrate). On the basis of these observations a hypothesis is forwarded concerning the mechanisms of migration of synaptic vesicles towards the presynaptic membrane. Measurements of the parameters of the dense projections suggest that the configuration of the presynaptic vesicular grid is not uniform along the presynaptic areas.

Acetates↗

PubMed1975

Distribution of ruthenium red staining material in the cerebral cortex of rat.

The ultrastructural distribution of ruthenium red staining material is studied in the cerebral cortex of rat. It is established that the material is located equally along the cell surface of the neurons, glial and endothelial cells, and within a number of cell organelles: mitochondria, smooth endoplasmic reticulum, synaptic vesicles and throughout both membranes of the nuclear envelope. Using digestion with hyaluronidase and trypsin, and lipid extraction an attempt is made to determine the participation of some chemical compounds such as acid mucopolysaccharides, glycoproteins, glycolipids and acid polypeptides in the composition of the ruthenium red-positive material. Moreover, the problem of the optimal conditions for the carrying out of ruthenium red staining in the CNS is discussed.

Animals↗

PubMed1974

Ultrastructural changes in the muscle cells of denervated muscles of rat.

The ultrastructural changes taking place in the diaphragm and plantaris of rat are followed up from the 3rd hour to 24th week after section of the peripheral nerve. The latter is either sectioned, or crushed. It is found out that the initial changes, consisting in an increase of the number of ribosomes and certain degree of mitochondrial destruction, are observed as early as the first 24 hours after denervation. The postdenervational changes are traced up to the occurrence of reinnervation with restoration of the myoneural junctions. A description is ade of the changes in the various organelles of the muscle cell, and of the appearance of spheromembranous bodies, hellical complex and destruction of the contractile apparatus. Differences in the course of the post-denervational process in the diaphragm and plantaris are outlined. The results obtained are discussed and comparatively studied with literature data.

Actins↗

PubMed1973