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Biomedical subjects

V P Fedorov

Publications and source records attributed to V P Fedorov.

At least 19 recordsLinked to original sources
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.

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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.

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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.

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PubMedDate not supplied

[Dynamics of the pathomorphological changes in the rat brain in relation to the dose of gamma irradiation].

Neurohistological, histochemical, electron-microscopic and biometric techniques were used to study the response of rat brain to irradiation within a wide range of doses. Nerve cells were shown to be highly radioresistant. At the same time, synapses and blood-brain barrier structures were highly radiosensitive. The pathomorphologic changes in different brain areas followed a dose-time function.

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PubMedDate not supplied

[Structuro-functional organization of the blood-brain barrier].

The analysis of the authors and published data allowed to conclude that the blood-brain barrier was a complex structural-functional system. Its basic components are endothelial cells, basal membrane, pericytes, tissue basophils, and astrocytes. The role of these structural elements in the permeability of blood-brain barrier has been studied. Organ-specific peculiarities of the brain tissue basophils have been established in rats, cats, and dogs. The astrocyte-capillary complexes were found to be very reactive, and at the same time, very plastic CNS structures.

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PubMedDate not supplied

[Status of the synapses of the end brain of rats exposed to the factors of space flight].

Using electron microscopy, synapses of different structures of the rat end brain related to cognitive and motor acts (sensorimotor cortex, caudate nucleus) as well as memory and behavior (hippocampus) were examined. Rats were exposed to ionizing radiation, super-high frequency, hypoxia, hyperoxia, vibration and acceleration (applied separately or in combination) which have been traditionally in the focus of space and aviation medicine. Brain interneuronal junctions were found to be very sensitive to the above effects, particularly ionizing radiation and hypoxia. Conversely, synapses were shown to be highly resistant to short-term hyperoxia and electromagnetic radiation. When combined effects were used, responses of interneuronal junctions depended on the irradiation dose and order of application of radiation and other flight factors.

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PubMedDate not supplied

[Morphological analysis of the reaction of the animal brain to short-term hyperoxia].

Reactions of various structures of the central nervous system of animals to short-term hyperoxia were investigated, using morphological methods available. Reactive, destructive and compensatory-adaptive changes in the structures taken under study were identified. These changes were nonspecific and similar in sign in rats and dogs. In most cases they were reversible but their polymorphism was different in phylogenetically dissimilar structures.

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