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Biomedical subjects

N I Pavlovskaia

Publications and source records attributed to N I Pavlovskaia.

18 recordsLinked to original sources
PubMed1986

[Effect of nootropil on the ultrastructure of the cerebral cortex of the aged rat].

The brain cortex was studied in 7 Wistar rats aged 25-35 months. Rats receiving nootropil (piracetam) showed intracellular regeneration (enrichment of neuronal nuclei for chromatin, increased degree of plication of nuclear membrane, nucleolar hypertrophy, increase in the number of cellular organellae which created a picture of perinuclear hyperchromatosis). Another important effect of nootropil was dramatic reduction of hydropsy of the neural tissue. Nootropil use was also associated with the development and strengthening of the compensatory/adaptive reaction expressed on the morphological level by the development of comprehensive structural contacts of astrocytes, oligodendrocytes and capillaries with different parts and each other. The use of nootropil made it possible to ascertain the reversible pattern of some morphological changes related to physiological aging.

Aging↗
PubMed1986

[Ultrastructural changes in the dendrites during aging].

Dendrite ultrastructure was studied in different brain areas of old rats, aged 28-30 months. Different ultrastructural forms of the reactive and destructive processes in the dendrites, irregularity of their pathomorphological changes with ageing and greater destruction of large dendrites, as compared to small ones are demonstrated.

Aging↗
PubMed1984

[Ultrastructural characteristics of the tissue changes in the cerebral cortex during aging].

The sensorimotor, visual and temporal portions of the brain were studied in seven rats aged 30-35 months. It has been established that the process of the ageing of the cerebral cortex is characterized by the polymorphism of structural changes and heterochronism of their development in the areas studied. The sensorimotor cortical area underwent the most pronounced destructive changes whereas in the process of ageing per se the dominant feature was presented by alterations in the protein-synthetizing apparatus of the cells. The destructive changes in the neuronal tissue were paralleled by compensatory-adaptive reactions expressed in the predominant increase of the amount of a particular kind of cell organelles and the formation of various types of contacts between neurons and other elements of the cortex.

Aging↗
PubMed1983

[Effect of ischemia and postischemic circulatory recovery on the ultrastructure of neurons].

In the investigation performed, a comparative analysis on the effect of ischemia and postischemic recirculation upon the neuron in the rat cerebral cortex and the dog spinal ganglia, common regularities and differences in appearance of pathological ultrastructural alterations were revealed. A general tendency towards increasing gravity of the pathological alterations was noted, as the period of ischemia and recirculation grew large. A leading type of the changes in the group of the injured neurons both in the spinal ganglia and in the cerebral cortex were changes of a chromatolitic type and they made one more general regularity. Hyperchromatosis was presented by an essentially less number of cases. The differences observed were presented as a rather greater polymorphism in the cortical neurons alterations comparing to the spinal ganglia cells at ischemia and postischemic recirculation. Besides, in the cortical neurons, more sensitive to the ischemic factor, diverced forms of the compensatory-adaptive reactions were revealed, that demonstrated plastic potentials of the cortical neurons.

Animals↗
PubMed1981

[Morphologic changes in the sensomotor region of the rat cortex in chronic alcoholic intoxication].

Alcohol was given to rats in a dose of 1 ml of 35-per-cent ethanol per 100 g body weight daily for 20, 40, 60, 90, and 120 days. Each period of the alcoholic intoxication was characterized by specific changes in the neurons, glia, and capillaries. Characteristic of initial periods of the alcoholic intoxication were reactive changes in the neurons: an important place in these changes belonged to compensatory-adaptive processes. The longer the period of the alcoholic intoxication, the greater the scope of the morphological changes, up to dystrophic lesions and grave forms of cell damage. A certain relationship between vascular changes and neuronal damages were noted.

Alcoholism↗
PubMed1981

[Effect of post-ischemic restoration of blood flow on neuron-glia-capillary interrelations].

The results of the study have shown that the changes occurring in ischemia are reversible. These changes are: perivascular edema of the astrocytes, dilation of the pericaryon and the cisterns of the endoplasmic reticulum, various forms of chromatolysis, and some changes of the capillary endothelium. An increase of the number of direct contacts between the basal membrane of the capillaries and the astrocytes, oligodendrocytes, neurons and their axons was observed. Complexes characterized by direct contact of all the constituents of the neuron-glia-capillary system were encountered. Such complexes were most typical for the median layers of the cortex. The types of the neuroglia-capillary interrelations described can be regarded as evidences of increased activity of the transport through the hematoencephalic barrier after post-ischemic restoration of the circulation. The direct contacts between the neurons. The glia, and the capillaries point to a possibility of direct exchange between the microcirculatory system and the neurons during the post-ischemic restoration of the circulation.

Animals↗
PubMed1980

[Ultrastructure of paired neuron contacts during the posthypoxic period].

Peculiar contacts between bodies of double neurons were revealed in the sensomotor cortex of the rat brain under ischemia and histotoxic hypoxia by means of the electron microscopic investigation. Ultrastructure of the contacting double neurons is not homogenous. In some cases, they do not differ from the normal, in other cases, certain signs of activation are revealed. In the contact area, peripheral focal chromatolysis is sometimes observed. In the double neurons the number of microtubules is often increased. In some cases, the cytoplasmic structure is altered (demonstrating certain activation in one of the cells) and combined with destructive processes in the neighbouring cell. The double neurons revealed can be divided into 3 groups: 1) pairs of morphologically identical neurons without specialized areas in the bordering membranes, 2) double neurons with specialized areas of membranes at places of their contacts, 3) double neurons with fusion of their cytoplasm at places where the cellular bodies come into contact with each other. The types of the double neurons described reveal some additional ways along which metabolism in neurons can occur.

Animals↗
PubMed1978

[Ultrastructural changes in capillaries of the cerebral cortex during ischemia].

Electron microscopic studies of dynamic capillary changes demonstrated a tendency towards a progressive decrease of the diameter or a complete occlusion by thrombs. Acute disorders of microcirculation due to a bilateral ligation of common carotid arteries lead not only to different reactions of the capillaries, but to destructive changes in the capillary endothelium. As a result of the developing ischemia, hypoxia has an important pathogenetical significance in disorders of circulation, inasmuch as it exerts influence not only on the nervous tissue, but on the capillaries leading to their dysfunction, an increase of the wall permeability and oedema. The easily developing oedema in conditions of hypoxia, evokes further lesions of the brain tissue which concerns the ultrastructure of cell elements in the whole system: capillaries, glia, neuron.

Capillaries↗
PubMed1978

[Early changes in the cerebral cortex in acute ischemia (light--electron microscopic study)].

Studies on the cortex of rats during different periods following ligation of the carotid arteries demonstrated an early appearance of ischemic changes, which were characterized by different states of the nervous cells, glial elements and capillaries. The largest group consisted of neurons of the deep cortical layers, which showed reactive states of the nucleus and nucleoli, as well as signs of chromatolysis in the cytoplasma. Less distributed form of pathology involved changes of the "dark" type, involving small stellite and pyramidal neurons of the upper cortical layer. Changes of the glial elements may be mainly considered as signs of oedema and partial melting. These changes demonstrate not only a different sensibility of neurons of the upper and lower cortical layers, but different mechanisms of the structural regulation in the cell metabolism, providing its optimal level and organization for each functional state.

Acute Disease↗
PubMed1977

[Ultrastructure of cerebral cortex capillaries in stroke].

Analysing the data of electronomicroscopical studies on the dominant hemispheres of the cerebral cortex in 9 patients who died due to strokes, the authors consider the main types of pathological changes in the ultrastructure of capillaries that are of a diffuse generalizing character. They are the following: 1) dystrophy of the capillary wall with the accumulation in it of lysosomal inclusions, lipofuscin granules, with the disintegration of mitochondrias and disturbances of oxidation-reduction processes in the vessel tissues connected with it; 2) the growth and hyperplasia of the endothelium. These changes lead to dystrophic damages of neurons, the maintainance and loading of the course of the main pathological process. Hypoxia, as a result of local ischemia, has an important pathogenetical significance in the disturbances of brain circulation and leads to plasmorrhagia, brain edema and even greater affection of neurons.

Capillaries↗
PubMed1975

[Changes in the mitochondria of human cerebral cortex nerve cells as the result of strokes].

The paper demonstrates that mitochondrias of human brain cortex neurons take an active part in the vital processes of the cells, acutely react to brain circulation disturbances revealing various destructive and compensatory-restorative reactions. The observed forms of the mitochondrias damages are described. The compensatory-restorative reactions of the mitochondrias consisted in an increase of their number, size and the surface of the inner membranes. The authors make attempts to display correlations between the found changes of the mitochondrias and the clinical picture of the stroke.

Aged↗