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Biomedical subjects

I B Ushakov

Publications and source records attributed to I B Ushakov.

At least 91 records · Page 5Linked to original sources
PubMed1992

[The possibilities for using new integral indices of the human peripheral blood].

In medical examination of flight personnel two new statistic indexes of integral estimate of changes in peripheral blood were used: integral blood deterioration ratio and entropy of leukocyte blood formula. These indexes have a rather high sensitivity that makes it possible to determine the tendency towards pathological changes in the organism, even if the whole blood picture will be within acceptance limits.

Blood Cells↗
PubMed1989

[The effects of space flight factors on the central nervous system. Structural-functional aspects of radio-modifying action].

The monograph has been dedicated to the analysis of structural and functional changes in the central nervous system of the experimental animals exposed to the isolated and combined effects of space flight factors. There have been shown many changes, which took place in the various anatomic-physiological formations of the brain, and evaluated their significance in organism's responses to the effects of ionizing and nonionizing radiation, hyperoxia, hypoxia, accelerations, vibrations and combined effects of some of those factors. The synergistic, antagonistic and cumulative (simple addition) effects of the investigated stressors along with the radiation factor on the CNS have been stated. This review is prescribed for the specialists in space biology, for physiologists, pathophysiologists, biochemists, radiobiologists and physicians.

Acceleration↗
PubMed1988

[Early changes in the integrative systems of the brain in rats during the combined action of ethanol and gamma-irradiation].

A study was made of Wistar male rats with the body mass of 250-270 g using neurohistological, electron microscopic and biochemical methods. The animals' heads were irradiated with gamma-quanta at a dose of 50 Gy, the rate of 6.7 cGy/s. Two minutes before or right after irradiation 15% ethanol solution (0.28 and 2.25 g/kg) was administered intraperitoneally. It was established that changes of interneuronal contacts in gamma-irradiation of the head were similar in nature to those caused by ethanol (2.25 g/kg). The effects of combined action of the above factors depended on the succession of exposure and a dose of ethanol. Slightly more noticeable synaptic changes, probably associated with mitochondrion affection and hyperhydration, were noted in ethanol administration (2.25 g/kg) after irradiation of the head.

Animals↗
PubMed1988

[Synaptic function of the cerebral cortex in gamma irradiation].

In adult rats 1.6 to 4.3 hrs after a single dose of gamma-irradiation (200 Gy), with developing neurological disorders, destructive changes were found in most of the synapses of brain sensorimotor cortex. All functionally important parts on the axonal and dendritic sides of the synapses were altered: mitochondria, synaptic vesicles, pre- and postsynaptic membranes, synaptic complexes and subsynaptic consolidations axonal and dendritic plasma and their incorporations. These changes are possibly causing the neurons disconnection and provide a structural basis for neurological deficits after substantial ionizing irradiation.

Animals↗
PubMed1987

[Modification of radiation changes in the hemato-encephalic barrier using exogenous hypoxia].

The authors conducted an experimental study of a radio-modifying effect of exogenous hypoxia on the structures of the blood-brain barrier in rats early after irradiation of the head at a dose of 10 Gy. Histochemical and histological methods were used to assess the status of the endothelium, basal membrane, tissue basophils and astrocytic junction. They indicated change of these structures in irradiation and action of GGS-8 gaseous mixture. Exogenous hypoxia was shown to promote the normalization of transport through the capillary wall as a result of the prevention of injury of the structure and metabolic processes in endothelial cells and basal membrane. The astrocytic junction and, to a certain degree, tissue basophils exhibited synergy in the action of the studied factors.

Animals↗
PubMed1986

[Phase changes in the permeability of the mouse blood-brain barrier after uneven gamma-irradiation].

Two phases of changes in blood-brain-barrier permeability for sour fuchsin have been observed in the early period after head or body irradiation at 2.58 C/kg: an increase (up to 2 h) and a decrease (from 2 to 6 h). The correlation between the decrease in BBB permeability and the frequency of clinical manifestations of radiation disease has been established. BBB permeability progressively increased later after head irradiation (24-120 h) which was indicative of its absolute dysfunction. The changes observed may reflect redistribution of fluid and electrolytes in the vascular bed and tissues leading to the onset of brain tissue edema.

Animals↗
PubMed1985

[Cytochemical determination of the enzyme activity of cerebrospinal fluid lymphocytes in dogs].

Cytochemical methods commonly used in hematology were applied to studying the liquor lymphocytes of dogs. According to our observation of decreasing their activity, the enzymes examined are placed in the following order: alpha-glycerophosphate, glutamate, lactate, and succinate dehydrogenase. High and reliable values of asymmetry and excess coefficients show the absence of the normal distribution of enzymatic activity in the investigated population of lymphocytes.

Animals↗
PubMed1984

[Experimental study of the effects of acute uneven microwave irradiation].

The purpose of the study was to reveal parts of the body affected by radiation most of all in uneven microwave irradiation (current frequency of 2.4 GHz/s) by the destruction criterion taking account of some indicators of the absorbed power of electromagnetic radiation (EMR). Uneven irradiation was achieved by the screening of some parts of the body with radiopaque material leaving unshielded parts subjected to irradiation. Control over the redistribution of absorbed energy was exercised by means of multichamber phantoms. In experiments on animals (female rats) within the range of specific absorbed power of 15-40 mWg the utmost affection of the cranial segment was revealed. The results show good correlation with a curve of the effect of 50% destruction criterion in total EMR irradiation.

Animals↗
PubMedDate not supplied

State of synapses of the cortex of cerebral hemispheres on gamma-irradiation.

In adult rats with developing neurological disorders we detected destructive changes in most of the synapses of the brain sensorimotor cortex 1.6-4.3 h after a single dose of gamma-irradiation (200 Gy). All functionally important parts on the axonal and dendritic sides of the synapses had undergone changes: mitochondria, synaptic vesicles, pre- and postsynaptic membranes, synaptic complexes, and subsynaptic consolidations, axonal and dendritic plasma, and their inclusions. These changes possibly cause disconnection of the neurons and provide a structural basis for neurological deficiencies following a high substantial ionizing radiation.

Animals↗