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Biomedical subjects

G V Konovalov

Publications and source records attributed to G V Konovalov.

At least 19 recordsLinked to original sources
PubMed1991

[Dysontogenesis of the brain of the progeny born to mothers drinking alcohol during pregnancy].

A study was made of the development of the brain from 44 embryos (5-12 weeks) and 1 fetus (14 weeks) obtained from mothers who used alcohol during pregnancy. 16 cases made up the control group. In 34 cases out of 45 (75.5%), deviations in the development of the brain were established and distributed into the three degrees of gravity: mild, moderate and severe. 11 variants of brain pathology are described. Deviations in the formation of brain walls and disorders of the development of the cortical lamina occurred most frequently (70.6 and 57.9%, respectively). In alcoholic mothers, brain pathology in their progeny was revealed in 100% of cases. Provided they used alcohol systematically and frequently, brain pathology was identified in 83.3% of cases, in systematic rare use of alcohol in 77.3%, and in episodic use of alcohol in 28.5% of cases.

Adult↗
PubMed1991

[Proliferative processes in nerve tissue culture under the action of ethanol].

The authors describe the ultrastructure of an organotypic culture of rat brain cortex exposed to small doses of ethanol. It is shown that the small dose of alcohol (0.5% ethanol) present in the nutrient medium induced proliferation of cytoplasmic membrane structure: hyperplasia of the endoplasmic reticulum with the formation of concentrically located membranes; an increase of the number and size of mitochondria was accompanied by the appearance of the giant, atypical forms of mitochondria; proliferation of vesicular components of Golgi's laminar complex.

Animals↗
PubMed1990

[The pathomorphological changes in the brain and internal organs in experimental influenza infection in mice].

The possibility of long persistence of influenza virus A in the brain and other organs of mice was established on the basis of complex virological, histological and electron microscopic studies. It was shown that the perivascular oedema of choroid plexus reaches the maximum during late stages of infection, after the clinical recovery. Sharp increase of the permeability of cerebral vessels causing the perivascular oedema, especially in choroid plexus of lateral brain ventricles, proposed to be one of possible mechanisms of pathogenic action of the virus.

Animals↗
PubMed1989

[Neuromorphologic studies in pathologic anatomy].

In the USSR, pathological neuromorphology that developed at the borderline of pathological anatomy, clinical neuropathology and psychiatry was represented by historically established research schools noted for great achievements. During the past two decades, the number of those skilled in this area has been, however, drastically reduced for a variety of reasons, adversely affecting both the research designs and the pathoanatomic care itself. The paper analyses the present-day pathomorphology of the nervous system in the USSR and provides the possible ways of eliminating the lag existing in the science and the perspectives of its development.

Magnetic Resonance Imaging↗
PubMed1989

[Effect of ethanol on the morphological characteristics of the cerebral cortex in tissue culture].

Light and electron microscopy were used to study the effects of different ethanol concentrations (0.5 and 1%) on the organotypic culture of neonatal rat cerebral cortex. Ethanol produced a biphasic effect. Primarily, the adaptive response of the tissue increased and cell differentiation accelerated. Later, destruction signs accumulated. These changes correlated with the strength and duration of the stimulus. Exposure to 1% ethanol induced the destruction.

Animals↗
PubMed1988

Interconnection of demyelination processes and inflammation in the dynamics of experimental allergic encephalomyelitis.

Using a new method for the simultaneous demonstration of myelin breakdown products and cell elements in the demyelinated nervous tissue, a number of previously unknown regularities were revealed concerning interconnection between demyelination processes and inflammation in the dynamics of experimental allergic encephalomyelitis (EAE). Alterations in osmophilia and in size of myelin breakdown products in the demyelination foci are demonstrated to be the most essential in the EAE pathomorphology, a certain type of cellular reaction corresponding to each stage of periaxonal changes. A close relationship was found between demyelination processes and inflammation which determines the structure of the demyelination foci at various stages of the disease.

Animals↗
PubMed1988

[A method of detecting demyelinated nerve tissue in experimental allergic encephalomyelitis].

A method of rapid pathomorphological diagnosis of demyelinization with a simultaneous detection of cell elements in the nervous tissue has been described. The method tested on the model of experimental allergic encephalomyelitis (EAE) is a modified method of Marchi with subsequent staining of histological sections with toluidine blue. Due to a shorter period of nervous tissue exposure to potassium bichromate and osmium acid solutions (from 6-8 weeks to 5 days) the cells preserve their ability to uptake the dye and the endurance of histological sections increases. Their thickness (2-3 microns) makes it possible to examine them in immersion magnification of the light microscope. Using the above method, we succeeded in revealing hematogenic and glial elements in demyelinating foci in the central nervous system of animals with EAE. The method described can be used for studying pathomorphology of multiple sclerosis and other demyelinating diseases in humans and their experimental models, as well as for the express diagnosis of demyelinization in pathoanatomical practice.

Animals↗
PubMed1987

[Dynamics of pathomorphologic changes in experimental allergic encephalomyelitis].

The new method of simultaneous identification of myelin degradation products and cellular elements in the demyelinated nervous tissue allowed one to determine some previously unknown regularities in the interaction of demyelination and inflammation processes during experimentally induced allergic encephalomyelitis. The most significant feature in the pathomorphology of this disease is shown to be the change in osmiophilia and the amount of myelin degradation products in the demyelination foci, with every stage of periaxonal changes corresponding to a certain type of cellular reactions. A close relation is revealed between the demyelination and inflammation processes determining the structure of demyelination foci at different stages of the disease.

Animals↗
PubMed1987

[Morphologic and biochemical changes in brain cells of mice with influenza].

The influence of influenza virus infection on the brain cells was studied in mice. Virology, electron microscopy and biochemistry methods were used for this purpose. It has been shown that intracerebral injection of pathogenic strain of influenza virus A/PR/8/34 is accompanied both by the reproduction of virus in the central nervous system tissue and the morphology changes in ependial cells of the vascular plexus of the brain lateral ventricle. It has been found that the level of the lipid peroxidation products in lipid extracts of infected mouse brain is greater than their level in extracts from control mouse brain. It has been concluded that the influenza virus has a damaging effect on the central nervous system cells.

Animals↗
PubMed1986

The effects of serotonin on the morpho-functional development of rat cerebral neocortex in tissue culture.

The morpho-functional development of the visual area of the cerebral cortex of newborn rats and effects of serotonin (5-HT) on these processes were studied in long-term (up to 40 days) organotypic cultures. It was shown that systematic addition of 5-HT in physiological concentrations to the nutrient medium during cultivation of the explants stimulates glia proliferation, neuron differentiation, neuropil formation, axon myelination and synaptogenesis. Electrophysiological studies of cortical cells in 5-HT-treated cultures showed earlier exhibition of spontaneous activity, increased number (by 33%) of spontaneously firing neurons and prevalence of periodic (bursting) type of discharges. Cultivation of neurons in a medium with 5-HT approximates their sensitivity to 5-HT to that observed in situ. The data obtained are indicative of the stimulating effects of 5-HT on the morpho-functional development of the rat cerebral cortex in tissue culture.

Animals↗
PubMed1982

[Demyelinization process in acute and subacute experimental encephalomyelitis].

The authors present the results of studying encephalomyelitis caused by the neurotropic (IHM) strain of the murine hepatitis virus in 60 mice of the C3H line infected intracerebrally at the age of 4 weeks. Morphological examinations of the brain carried out on the 5th-13th day (the acute period) and the 14th-30th day (the subacute stage) have shown that it is myelin-producing cells that are affected first in this form of encephalomyelitis, while the periaxonal process observed is a consequence of this affection. Proofs of this conclusion are presented. It is shown that in subacute encephalomyelitis, similar processes develop. Degeneration and infection of oligodendrocytes are not so pronounced in that case, as in the acute disease. However, destruction of even individual oligodendrocytes may lead (due to the peculiarities of their structure and function) to an avalanche-like process of demyelinization. It is supposed that the vesicular degeneration of myelin may arise in the sites of close contact between the myelin membranes and the cells of inflammation infiltrates (release of lysosomal enzymes and toxic products formed in edema). In the latter case the viruses serve as an antigen depot that causes and maintains the inflammatory process.

Acute Disease↗
PubMed1982

[Changes in the neurons of the spinal cord and spinal ganglia in hypokinesia (a neuromorphological and histochemical study)].

On 62 white male rats at hypokinesia lasting for 7-60 days, motoneurons and neural cells of the lumbar sensitive ganglia have been studied at the level of L2--L4. Certain changes in the spinal ganglia have been neurohistologically revealed beginning from the 30th day of the experiment. In most of the neurons, mainly in large ones, phenomena of central chromatolysis are observed. In one-third of the cells, nuclear hyperchromatosis of various intensity is noted. As the experiment proceeds, the changes acquire a well developed character. In the spinal motoneurons, on the 30th-45th day of the experiment, peripheral chromatolysis, moderate nuclear hyperchromatosis nuclear hypertrophy are detected. Satellite neuroglia is increased according to the "Umklammerying" phenomenon. Cytophotometric investigation of SDG, NAD-D and AF demonstrates certain discoordination in their activity. On the 7th day, SDG and NAD-D activity in the spinal ganglia increases. Beginning from the 30th day, SDG and NAD-D activity in the objects studied decreases, while that of LDG and AF increases. Hypoxia is suggested to be the cause of the disorders observed. A supposition is made that the high AF activity could result in the disturbed activity of the enzymes localizing in mitochondria.

Animals↗
PubMed1981

[Demyelinating processes of a viral nature].

Demyelination processes due to viral infections (encephalomyelitis induced by mouse hepatitis virus, Theiler's encephalomyelitis, canine distemper, and marek's disease) were simulated in laboratory animals to study the corresponding human diseases (multiple sclerosis, multifocal leucoencephalopathy, Guillain-Barre's syndrome). The following mechanisms of tissue injury are discussed: (1) viral damage of myelin-supporting cells, (2) demyelination occurring as a side effect of specific and non-specific inflammatory reactions to the viruses persisting in the nervous system, (3) autoimmune reaction triggered by virus infection. Special attention is paid to the role of virus agents in the development of these processes.

Animals↗
PubMed1980

[Effect of noradrenaline on the growth and differentiation of cellular elements of the rat hippocampal explants].

Newborn rat dorsal hippocampal cultures of prolonged growth were cultivated in rotating tubes and Maximov's chambers. During the whole cultivation period (3-32 days) noradrenaline (NA) (3 mkg/ml) was added to the nutritional medium of the test explants. The test cultures and controls were studied at short intervals by means of supravital staining with methylene blue, Nissl's technique and electronmicroscopically. NA, unlike serotonin, inhibits proliferation of glial cells and substantially decelerates the process forming neuroglial interrelation. Inhibition of neuroglial proliferation results in decelerated axonal myelinization and in formation but a small (as compared to control cultures) number of myelinated fibres. Although NA does not significantly affect the formation of synapses, nevertheless the synapses structurally differ from those in intact media. The data obtained were compared to those in the previous investigation (Arch. anat., 1978, V. 74, p. 98-106). It is evident that biogenic amines (NA and serotonin) oppositively and essentially affect the processes of the hippocampal organization in rats at early stages of postnatal ontogenesis. This coincides with the hypothesis on reciprocal functional interrelation of serotonin- and noradrenalinergic cerebral structures.

Animals↗