Biomedical subjects
Publications and source records attributed to T V Vorob'eva.
The state of usage of food supplements was studies in Kiev and some Ukrainian regions. Remains of widely using food supplements were determined. The attempt to determine food supplements load on the person. The results of investigation have shown a possibility of food supplements consumption in amounts bordering upon permissible daily level or exceeding them.
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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.
Using light and electron microscopy, the frontal, temporal and parietal cortical neurons were studied in 10 cases of senile dementia. It was found that along with general age-specific disorders of the ultrastructure of neurons and glial cells (varying degrees of chromatolysis, accumulation of lipofuscin, mitochondrial changes) the examination revealed ultrastructural shifts which might be characteristic of senile dementia. They include rearrangement of nuclear chromatin, destruction of nuclear membrane with the subsequent vacuolization of the nucleus and karyolysis, the appearance of polymorphic fibrillar inclusions in the cytoplasm of neurons and gliocytes, as well as the disappearance of subsuperficial cysterns. Destructive processes were also attended by signs of compensatory changes, i.e. displacement of the nucleolus to the nuclear periphery, the development of desmosomophide contacts at the site of the neuron and glial satellite cell contact, the grouping of cells, and frequent fusion of the adjacent cellular elements.
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.
Ultrastructural aspects of the secondary brain stem syndrome in patients with hemorrhages and infarcts in the brain hemispheres are considered. The secondary brain stem syndrome is manifested by diverse clinical symptomatology suggestive of dysfunction of different levels of the brain stem: a diminished level of awakening, oculomotor disturbances, changes in the muscle tone and reflexes, cardiorespiratory and other vegetative disorders. Examining the reticular formation of the brain stem under the electron microscope the authors revealed changes in neurons in the form of chromatolysis, an increase in the cellular cytoplasm of the number of lipid inclusions and lysosomes, swelling of mitochondria and (less frequently) the appearance of cells with an elevated osmiophilia of the cytoplasm. Also observed was a systemic increase in lysosomes and lipid granules in capillary structures, and in glial and nervous cells. The pathogenetic factors of secondary brain stem syndrome are discussed.
Changes in spatial interrelations of the spinal cord capillaries and motoneurons and capillary ultrastructure were studied under hypokinesia. Spatial interrelations between the capillaries and neurons were not demonstrated to change under hypokinesia. They were estimated by the following parameters: area of neuronal profile field, number of capillaries, their length, distance from the nerve cell body, capillary bed area and index of capillary-neuronal interrelations. Quantitative investigation revealed capillary stenosis: their diameter was one and a half times less under hypokinesia. Morphologically, capillary stenosis was accompanied by the basal membrane thickening and endothelial cytoplasm vacuolization. There was a direct relation between endothelial villi and the places of the endothelial cells contacts, dilatation of the contact interstices and solidifying of their borders. Changes in the capillaries were followed by reactions in the pericapillary structures, such as: fibrillae were formed, mitochondrii accumulated in the perivascular glial projections, the membrane next to capillary astrocyte projections underwent desmosome-like condensation. Mitochondrial accumulations were also observed in the nerve cell projections and in their cytoplasm sites contacting with the blood vessels.
By means of optical and electron microscopy the authors studied some morphological symptoms of the glial reaction to hypoxia in different periods of a posthypoxic states. The obtained data were compared with neuron changes in compensatory-adaptative, reparative and pathological states developing during the same period. A study of the changes in the satellite glia was performed with a calculation of the number of nuclei and a subsequent statistical analysis of these data. The achieved data indicate that there is an increase of the amount of satellites around the neuron when the morphological signs of reparation are most expressed as well as changes of the ultrastructure in the satellites. Such facts may speak of an active involvement of the neurons in reparation. The achieved data are discussed in the aspect of their connection with astrocyte glia and oxidative metabolism.
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.
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.
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