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Biomedical subjects

V N Kleshchinov

Publications and source records attributed to V N Kleshchinov.

At least 19 recordsLinked to original sources
PubMed1991

[The effect of different methods of isolating thrombocytes on the surface structure and biochemical parameters of the serotonin system of these cells].

The method of platelets' isolation influences their morphofunctional state. The study of the surface structure of platelets with the method of scanning electron microscopy shows, that the nonactivated form of platelets is characterized for the cells, isolated by gel filtration, but platelets which are isolated by centrifugation are activated. Platelets' activation under centrifugation is shown to connect with the changes of biochemical parameters of platelet serotonin system: the increase of the velocity of the 3H-serotonin reuptake and of the 3H-imipramine specific binding.

Adult↗
PubMed1990

[Plastic metabolism in neurons altered according to the hypochromic type].

Ribonucleoprotein structures and condensed chromatin (CCh) have been studied electron cytochemically in neurons of the rat cerebral sensomotor cortex at their reversible (injection of aminazine) and irreversible (postmortem and posttraumatic processes) alterations according to the hypochromic type. For the hypochromic neurons, revealed after aminazine administration, increasing metabolic activity in their plastic apparatus is specific: intensification of the nuclear-cytoplasmic transport of RNA (decreasing amount of interchromatin granules and fibrils), when the acid synthesis is preserved, presence of small fibrillized clumps (SC), perichromatin fibrils (PChF); nucleolar structure is specific for the stage of active functioning. At the postmortem and posttraumatic alterations of the neurons according to the hypochromic type, the functional activity of the system DNA--RNA--protein in them is inhibited: mainly, the transcriptive activity of nuclei decreases (PChF, SC disappear and CCh appear). Combination of these processes with development of hydrolytic changes (nonidentified electron opaque material appears, CCh clumps and perichromatin granules undergo fibrillization, ribosomes decrease in their number) reflects certain irreversible lesions of hypochromic neurons.

Animals↗
PubMed1989

[Ultrastructure of mitotically dividing cells with signs of neurons in the rat brain].

Ultrastructure of mitotically dividing cells in the sensomotor cerebral cortex of mature rats has been investigated, after transplantation into them embryonal nervous tissue of 17-day-old embryos. In 4 days after the operation in the recipient's nervous tissue, arranging around the developing transplant, among various proliferating cells with mitotic figures, some cells with signs of neurons (oval bodies, electron opaque cytoplasm with developed organelles and RNP-particles, specific for the nervous cell, with axonal terminals on the body) have been found. These cells are surrounded with the satellite glia. There are no mitotic figures in the pyramidal neurons.

Animals↗
PubMed1989

[Nucleolus-like bodies and neuronal differentiation in the anterior hypothalamus of rats].

The emergence of nucleolus-like bodies was studied during differentiation of neurosecretory hypothalamic neurons. Nucleus supraopticus was studied in offspring of intact rats and in offspring of mothers injected with anti-hypothalamic antibodies stimulating hypothalamic tissue differentiation during gestation. The degree of structural and functional differentiation of neurosecretory cells correlated with the number of neurosecretory cells and of neurons with nucleolus-like bodies. The authors believe that these bodies' formation is a physiological event linked to development of specific function of neurosecretory cells. Morphologically, nucleoli and nucleolus-like bodies were different, with nucleolonemms absent in the latter.

Adolescent↗
PubMed1987

[Ultrastructure of neurons manifested by hyperchromia and vacuolization observed in nerve tissue following hypoxia].

100 days after the exposure of the rat sensorimotor cortex to hypoxic hypoxia two types of hyperchromic neurons with vacuolization of the cytoplasm were described. Using electron cytochemical method for the differential staining of ribonucleoproteins, it has been shown that the first type of hyperchromic neurons were cells with irreversible dystrophic changes and the second type were cells without irreversible dystrophy but with changes in the DNA-RNA-protein synthesizing system.

Animals↗
PubMed1986

[Neurons in the hyperchromic state].

The paper summarizes findings concerning the ultrastructure and cytochemistry of the cortical hyperchromic neurons which appear under different experimental conditions (in intact animals, in mechanical traumatization of neuronal tissue, during formation of a local focus of destruction, upon the administration of aminazine, and in the process of autolysis). Characteristics of the development of the hyperchromic status in each of the above experimental situations are specified. The authors consider the questions concerning the life-time development of neuronal hyperchromia, a relationship of hyperchromia with a certain function of the cell and the reversibility of the ultrastructural and cytochemical shifts characteristic of hyperchromia. A conclusion is made about the development of hyperchromia during life (with the exception of autolysis), its correlation with a decreased functional activity of the cell and the possibility of hyperchromia involution. Hyperchromic cells proved to be highly resistant to autolysis.

Animals↗
PubMed1986

[Electron microscopic and cytochemical research on the function of the glial cells in a focus of local cortical destruction].

The activity of DNA-RNA-protein synthesizing system of some glial cells was studied using electron cytochemical method for determination of chromatin state and RNA-particles. A dependence of functional state of satellite glial cells (oligodendroglia and astroglia) on the tinctorial neuron state (hyper- and hypochromic scale) was shown. The functional state of interfascicular oligodendroglial cells has been characterized.

Animals↗
PubMed1986

[Ultrastructure of neurons with initial signs of ischemization in schizophrenia].

The authors studied two cases of sudden death of schizophrenia patients aged 23 and 40 years who died from acute asphyxia. Two types of ultrastructural changes in their cortical neurons are described: gradual lightening of the cytoplasm and nuclei in some cells; cytoplasm lightening, perinuclear edema and increased nuclear density due to condensed chromatin in others. Cytoplasm lightening is explained by swelling of the cysterns of the endoplasmatic reticulum and loss of polysomes. The first type of changes was characteristic of cortical pyramidal neurons; the second, of cortical interneurons. The described types of neuronal changes were combined with the appearance of hyperchromic and shrunk neurons whose formation is believed to be related to the schizophrenic process. The probable reversibility of neuronal alterations in acute asphyxia is discussed.

Adult↗
PubMed1985

[Electron-cytochemical characteristics of hyperchromic neurons in schizophrenia].

During autopsy of brains from 17 schizophrenic patients and 14 mentally normal subjects the authors studied metabolic characteristics in hyperchromic neurons, using methods of electron cytochemistry. The parameters of plastic and energy metabolism investigated included ribonucleoproteins (RNP), Mg-activated ATPase and succinate dehydrogenase (SDH). Two types of neurons with a different degree of hyperchromia and a decrease in metabolic activity were identified. The type I neurons were characterized by a marked decrease in the activity of the studied enzymes and the number of RNP particles, type II neurons by almost complete absence of enzymic activity and a sharp decrease in RNP particles. The results obtained make it possible to consider the hyperchromic neuron as a cell with a diminished functional activity.

Adenosine Triphosphatases↗