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Biomedical subjects

A S Stupina

Publications and source records attributed to A S Stupina.

At least 19 recordsLinked to original sources
PubMed1991

Ultrastructural study of clinically uninvolved skin of patients with pemphigus vulgaris.

We investigated skin biopsies from pemphigus vulgaris (PV) patients by light, fluorescent and electron microscopy in order to study the ultrastructural appearances of epidermis at the pre-acantholytic stage. The biopsies were obtained from uninvolved forearm skin in 10 patients with PV in the acute stage of the disease, from perilesional skin of the same patients as well as from the forearm skin of 10 healthy subjects. Light microscopy showed no pathological changes in clinically uninvolved skin of pemphigus patients. Direct immunofluorescence confirmed the presence of IgG auto-antibodies fixed in intercellular space of the spinous-cell layer of uninvolved skin. Electron microscopy of the uninvolved skin biopsies revealed the following changes: disintegration of desmosomes of spinous cells with their replacement by finger-shaped protrusions of cytoplasm; clarification of the nuclear matrix; widening of the perinuclear slit; an increased number of secondary lysosomes in cells; oedema and swelling of mitochondria with destruction of their cristae. The cells retained their polygonal shape and the intercellular distance did not increase. We conclude that at the pre-acantholytic stage the breakage and dissolution of desmosomes precedes the increase in the intercellular space.

Acute Disease↗
PubMed1990

[The ultrastructural changes in the clinically unaffected skin of patients with pemphigus vulgaris].

Analysis of the results of light optic, immunofluorescent, and electron microscopic studies of biopsy specimens of intact skin of forearms and of the skin adjacent to lesions in 10 patients with untreated pemphigus vulgaris has lead the authors to a conclusion on the uniform pattern of ultrastructural changes in all sites of the epidermis in pemphigus patients. A combination of the signs of involvement of prickle and basal-cell structures (desmosomes and mitochondria) and of signs of cellular metabolic activation (euchromatism, active status of the nucleolus) anticipate the development of intra- and extracellular changes in pemphigus.

Adult↗
PubMed1990

[Ultrastructural manifestations of blood-tissue barrier reactions to acute hypoxia in old animals].

Readjustments occurring in different blood-tissue barriers (the brain, endocrine glands, heart, liver, jejunum) in response to acute hypoxia in old animals develop against the background of the preceding age-specific changes, including the adaptive ones. This results, first, in a significant narrowing of the adaptive reaction range and, second, acceleration and deepening of destructive processes in tissues and prolongation of the restoration period.

Acute Disease↗
PubMed1989

Effect of enterosorption on animal lifespan.

Experiments were performed on Wistar male rats, starting from the 28th month of age. The effect of dietary sorbent (non coated nitrogen-containing carbon administered as 10 day courses at 1 month intervals in dosage of 10 ml/kg) on lifespan and a number of biological indices were studied. Enterosorption resulted in the increase of mean and maximal lifespan by 43 and 34% respectively. Analysis of the effect of enterosorption on activity of microsomal enzymes, intensity of total RNA and protein biosynthesis, lipid metabolism, formation of free radicals etc. showed that it produced a positive influence on the functional state of the studied systems and increased the organism's adaptive capacities. Enterosorption was found to delay the rate of onset of age-related structural changes in the organs and tissues.

Aging↗
PubMed1989

[Age-related ultrastructural characteristics of various cells in acute hypoxia].

Ultrastructural peculiarities, concerning reaction of cells in various populations brain-sensorimotor cortex, mammillary nuclei, vascular plexus; myocardium; liver; jejunum) in mature (6-8 months) and old (24-30 months) male white Wistar rats have been studied at an experimental acute hypobaric hypoxic hypoxia. Both general changes, that are manifested in various degree in different cell groups and organo-specific ones are noted. The manifestation degree of the reactive changes is evidently connected with certain metabolic and functional peculiarities, as well as with the character of cell restoration. In the old animals hypoxic hypoxia produces more profound destructive processes in all cell populations studied. This is accompanied with a restriction in ability to adaptation.

Acute Disease↗
PubMed1988

[Morphological manifestations of compensatory-adaptive processes in the liver during aging].

Light and electron microscopy and morphometry revealed an age-related increase in the average size of hepatocytes and their nuclei in 24- and 30-month-old rats compared to 8-month-old animals, the density of hepatocytes distribution per area unit being decreased. In 24-month-old rats the number of binuclear hepatocytes increased with a subsequent decrease in their number in 30-month-old animals, which accounted for the shift in regeneration processes during ageing to predominantly intracellular one. The number of sinusoidal cells per area unit in three age groups was statistically similar. The results of morphometry and electron microscopy suggest that the compensatory-adaptive processes during hepatocyte ageing were mediated by intracellular regeneration, which led to cellular and nuclear hypertrophy similar to that observed in cells of static population (neurons, cardiomyocytes).

Adaptation, Physiological↗
PubMed1987

[Intranuclear inclusions in the cells of different tissues of the aging rat].

Ultrastructure of neuronal and glial nuclei has been studied in various parts of the CNS, in parenchymatous cells of internal organs, in endotheliocytes and pericytes of their blood capillaries in intact rats--mature (6-8-month-old) and old (26-28-month-old), as well as at certain experimental influences. In all the cellular populations studied (most often in neurons), various in their structure, intranuclear inclusions (INI) have been revealed, that are considered as five main types. The number of INI increases sharply at ageing, that is especially noticeable under experimental conditions. Some INI are situated in morphologically preserved, actively working cells, being normal components of the nucleus, others--reflect profound rearrangements of nuclear proteins, disturbances in lipid metabolism up to irreversible destructive processes in the nucleus.

Aging↗
PubMed1985

[Characteristics of the wall of the 3d cerebral ventricle in rats from the viewpoint of age].

The results of the light-, electron microscopic and cytophotometric investigation performed in the wall of the third cerebral ventricle are presented. It includes the ciliar, tanycytar ependyma and subependymal layer in male rats of three age groups (immature--1 month, mature--8-10 months and old--24-26 months of age). A certain decrease in the arrangement density of cellular elements of the ventricular wall is noted with age. A depressed functional activity of the ciliar ependymocytes is revealed with ageing. At the same time, some compensatory-adaptive rearrangements develop; they counteract age decrease of the function. A suggestion is made that the drenage function of the ciliar ependymal area is disturbed with age. Specific age features of the ultrastructure of the blood capillaries situating subependymally are revealed. The age changes of ependymocytes and tanicytes, as well as those of certain groups of tanycytes are not unitypical; this speaks in favour of their different functional role.

Aging↗
PubMed1985

[Stereologic analysis of the respiratory zone of the lungs of the laboratory rat and man during aging].

By means of stereological analysis methods, lungs of mature and ageing laboratory rats and those of human beings at the age of 21-40, 41-60 and further have been studied. During the process of ageing the fraction of nonparenchymatous structures increases, while that of parenchyma decreases. Architectonics of acini is described: the volume of central passages increases and the volume of alveolar air decreases. The form of the alveoli approaches the spherical one. The area of the internal surface and the alveolar volume increase. The total number of the alveoli and the area of the respiratory lining decrease. The total number of the alveolar capillaries does not change, however, the density of their distribution grows small. The area and volume of a separate segment of the alveolar capillaries grow large. The age rearrangement of the respiratory zone morphologically differs from the changes that are observed at the obstructive emphysema.

Adult↗
PubMed1984

Enterosorption in prolonging old animal lifespan.

The effect of repeated courses of enterosorption upon the mean and maximal lifespan and some functional and metabolic indices was determined in 28-month-old Wistar rats. Significant increase of mean and maximal lifespan of old rats was noted at certain regimens of enterosorption. The experimental animals demonstrated less marked age-related structural and ultrastructural changes in the liver, kidneys, myocardium, intestines, pancreas, as compared with control animals. Enterosorption leads to a reduction of pentobarbital-induced sleep, decrease of content of cytochrome P-450, blood cholesterol and triglycerides, cardiac and cerebral tissue cholesterol, total lipids, liver cholesterol and triglycerides. Enterosorption was found to increase the RNA and protein biosynthesis in the liver, kidneys and adrenals of old animals.

Aging↗
PubMed1981

[Age and ultrastructural features of adrenal capillaries in rats following ACTH administration and in insulin shock].

Electron microscopy was used to study age-associated features of blood capillaries of adrenal cortical substances and adrenal medulla in adult and old rats during ACTH administration and insulin shock. It has been revealed that as a result of an increase in adrenal function of the adult rats, endotheliocytes of cortical substance and medulla developed ultrastructural changes promoting the intensification of transcapillary metabolism. The old rats showed pathological changes in the endotheliocyte ultrastructure, responsible for the development of capillary insufficiency of the adrenals during stimulation of their secretory activity.

Adrenal Glands↗
PubMed1981

[Ultrastructural characteristics of the cerebral capillaries of aging animals subjected to hypoxic hypoxia].

The ultrastructure of capillary walls of the mamillary bodies was studied in rats distributed in two age groups: adult (6-8-month-old) and old (28-30-month-old) animals under hypoxic hypoxia. It was found that age-related differences in the response of brain capillary walls to the injuring agent were reduced to a rapid increase in dystrophic phenomena and less conspicuous compensatory processes seen in the old animals. More profound injuries to other brain tissues adjacent to the vessels were also indicative of less efficacy of the adaptive reactions in the old animals.

Age Factors↗
PubMed1979

Mechanisms of neurohumoral regulation of heart function in aging.

Changes in hemodynamics and myocardial contractile capacity following the stimulation of extracardial nerves and administration of various doses of acetylcholine, norepinephrine, propranolol, phentolamin, atropine, serpasil and benzohexonium were studied in albino rats, rabbits and cats of various age. The shifts in cardiac acetylcholine and norepinephrine content and the activity of some enzymes of their catabolism were determined as well. Functional changes were compared with the structural shifts in intramural nervous system. In old animals there was a rise in threshold of voltage, which induced threshold reaction at stimulation of n. vagus and n. sympaticus and there was a change in heart sensitivity to acetycholine and norepinephrine, propranolol, atropine, serpasil and benzohexonium. A relationship was shown between age changes in nervous regulation of heart and transmitter metabolism. The intensity of acetylcholine and norepinephrine synthesis was decreased in old age, the transmitter metabolism in various parts of the heart was not uniformly altered, the sensitivity of epicardial chemoreceptors to nicotine, veratrum, acetylcholine was increased. The reflexes from cardiac mechanoreceptors were diminished.

Acetylcholine↗