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Biomedical subjects

G M Vakulin

Publications and source records attributed to G M Vakulin.

At least 19 recordsLinked to original sources
PubMed2005

[Morpho-functional characteristic of kidneys in mother, fetus and the offspring subjected to vibration of industrial frequency during gestation].

The aims of the present study were to investigate the nature of morpho-functional changes in the kidneys in mother, fetus and the offspring subjected to the dosed effect of vibration during gestation. The study was performed in pregnant female Wistar rats (n = 28), fetuses (n = 26) and the offspring aged 3 months (n = 20). Rats were subjected to vibration from Day 9 to Day 19 of gestation (the period of intensive metanephros development), using vibration test bench with fixed parameters: frequency of 32 Hz and acceleration of 50 m/s2. Renal structures were studied using morphometric methods, the ultrastructure of renal cells was examined. In pregnant females and in mature offspring, the nephrons of subcapsular, inrtacortical and juxtamedullary zones were studied. Taking into account organo- and histogenesis of embryonic kidney, in fetuses only nephrons of the last three stages of differentiation and S-shaped tubules were studied. It was found that in adult animals juxtamedullary and subcapsular renal zones were most sensitive to the effect of vibration. Morpho-functional signs of the damage to the filtration barrier were also noted. In the metanephros of fetuses, the maturation of nephrons was retarded, and the regular formation of intercellular junctions was disturbed. In the kidneys of immature offspring the number of nephrons was increased.

Animals↗
PubMed2005

[Changes in liver and in some organs of immune system of animals exposed to twenty-four-hour illumination].

The aim of this research was to study the morpho-functional organization of liver and some organs of immune system in animals exposed to continous twenty-four-hour illumination (CI) for 14 days. Using the methods of light and electron microscopy and morphometric analysis of histological preparations, liver and regional lymph nodes (hepatic in rats and iliac in mice) were studied. It was found that CI resulted in a state of dyschronosis, which was structurally manifested by the changes of diurnal variations of morphometric parameters of liver and its draining lymph nodes, disturbances of hemo- and lymphocirculation, destruction of cellular membranes. Response of central and peripheral organs of immune system to CI included the changes of diurnal variations of blast forms and mature lymphocytes, that was also indicative of dyschronosis development.

Animals↗
PubMed2005

[Morpho-functional changes of liver and its regional lymph nodes after exposure to magnetic field of industrial frequency].

The aim of this research was to study the morpho-functional organization of liver and its regional lymph nodes, as well as of other organs of immune system, in animals exposed for 14 days to a magnetic field of industrial frequency (MFIF) with aperiodic oscillations of amplitude of magnetic induction in the range of 5-10 _Ts. The methods of light and electron microscopy were used. Damage to DNA in hepatocyte nuclei was determined using ethidium bromide. Quantitative analysis of the cells in the organs of immune system was performed, blood leukocyte formula was calculated and the activity of oxidative enzymes in blood cells was determined. It was found that MFIF caused micro- and ultrastructural changes in animal liver and its regional lymph nodes, which included the disturbances of hemo- and lymphocirculation, destruction of cellular membranes in some cells, dilation of rough endoplasmic reticulum cisterns, appearance of degenerate mitochondrial forms, glycogen depletion, that collectively indicated the development of tissue hypoxia. The increase in the activity of nuclear endonucleases was detected. Response of organs of immune system to MFIF was manifested by shifts of blast forms/ mature lymphocytes ratio in hepatic regional lymph nodes and by the changes of energy metabolism of blood lymphocytes.

Animals↗
PubMed2002

[Modification of the Bilshovsky method for studies of nerve tissue paraffin sections].

The Bilshovsky method is often used for studies of the morphology of neuronal fibrillar system. The classical variant of this method requires sections made with a freezing microtome, which is sometimes inconvenient. Preparation of paraffin sections often gives unsatisfactory results. The authors managed to overcome this deficiency. Their modification consists in the following: after deparaffinization of paraffin sections glued to the slides they are repeatedly fixed in warm formalin and then treated with silver nitrate with heating. This modification is easily reproducible and essentially simplifies staining; no freezing microtome is needed.

Alzheimer Disease↗
PubMed1998

Macrophage stimulation and antitumor effect of Ukrain.

It has previously been demonstrated that Ukrain administration (0.5 mg in mice of 20 g, five times) to A/Sn mice results in retardation of HA-1 tumor growth in the liver and a prolongation of lifespan compared with untreated controls. In the present study Ukrain was tested as a macrophage stimulator in intact mice and animals with HA-1 hepatoma. There were no changes to the carbon particles phagocytosis rate in the case of a single administration of Ukrain to intact mice. Significant secretion of procathepsin B into ascitic fluid was shown in tumor mice as well as marker enzyme of macrophages beta-hexosaminidase activity, suggesting an influx of macrophages into ascites. Single Ukrain administration increased this index, and repeated drug injections were followed by a tendency to normalization of secretion. The cytolytic effect of Ukrain against tumor cells (as a result of macrophage stimulation) is the most probable mechanism of its antitumor action, but this suggestion needs further experimental evidence with special attention paid to the balance of proteinases and endogenous proteinase inhibitors.

Adjuvants, Immunologic↗
PubMed1986

[Effect of the lysosomotropic preparation suramin on the ultrastructural and functional characteristics of rat liver cells in acute toxic hepatitis].

A study was made of the influence of suramin and of a combination of suramin and CCl4 on the ultrastructure of hepatocytes, structural and functional state of lysosomes and functional activity of the rat's liver. The latter was characterized by alanine aminotransferase level in blood. Increasing amounts of autophagosomes as well as lysosomal fusion disturbances were registered 24 and 48 hours after a single suramin administration. The combined suramin and CCl4 administration resulted even in a higher damage of hepatocytes. A decrease in the intralysosomal rate of proteolysis in hepatocytes, was also shown in addition to the impairment of liver functional activity. Some ultrastructural features of compensation of the insufficiency of the hepatocyte vacuolar apparatus were noted during suramin and CCl4 administration. Changes in the nucleolar structure were noticed in hepatocytes administered both suramin and CCl4. It is suggested that these changes may involve a compensatory increase in nucleologenesis due to the decrease in the activity of the protein-synthesizing apparatus in hepatocytes.

Acute Disease↗
PubMed1985

[Tubulointerstitial component of chronic glomerulonephritis. Clinico-morphological comparisons].

A total of 179 patients with chronic glomerulonephritis were examined for the development of the tubulo-interstitial component (TIC) of the disease. It was established that the rate of the development and intensity of the TIC are linked with different morphological variants of GN and increase successively in mesangiomembranous, membranous, mesangioproliferative, mesangiocapillary (and lobular) GN, reaching a maximum in diffuse fibroplastic GN. In patients with no TIC, the hematuric and latent forms of CGN were mostly encountered. The disease took a stable course, with a frequent occurrence of improvements and remission. The 5-year survival was 100%. In patients with a moderate TIC, the nephrotic form of CGN was encountered more often than in other patients. As regards other characteristics, this form occupied an intermediate position, with the 5-year survival rate amounting to 91%. Patients with a pronounced TIC were marked by progressive CGN, which was largely observed in the hypertonic and mixed patterns of the disease. The three-year survival amounted to 34% in this case. The TIC of CGN is an important prognostic factor and the dissimilar course of different morphological variants of CGN is accounted, to a considerable degree, for by the dissimilar rate of TIC development.

Basement Membrane↗
PubMed1981

[Ultrastructural and cellular functional activity changes in the zona fasciculata of the rat adrenal cortex resulting form the prolonged administration of adrenocorticotropic hormone].

The fasciculata zone cell ultrastructure has been studied in addition to the level of steroidogenesis of rat adrenal glands on days 2,7 and 13 after the administration of ACTH with prolonged action. The marked changes in the ultrastructure of different cells have been noticed, some of which suggest a compensatory stimulation of hormone production, and the others indicate irreversible subcellular injuries. Changes in the cell ultrastructure show the phase character in time to correlate with changes in the activity of the corticosteroid synthesis and secretion.

Adrenal Cortex↗
PubMed1978

[Effect of sex and phase of the estrous cycle on the intensity of the damage and recovery processes in the liver of rats following acute carbon tetrachloride poisoning].

Morphometric, histochemical, and electron microscope methods were applied to the study of peculiarities of Wistar rat liver damage and recovery, depending on sex and phase of the estrous cycle, and also under conditions of deficiency of sex hormones and after the beta-estradiol injection to ovariectomized animals. A marked increase of the structural alterations caused by CCl4 and inhibition of the restoration reactions in the liver of female animals, both during the natural increase of blood estrogen concentration and under the effect of exogenous estradiol, as well as the protective effect of ovariectomy were demonstrated. As for male rats, the structural damage in the liver was more expressed than in the females with a low blood estrogen level and differed but little from the changes in the female animals during increased sex steroids secretion.

Animals↗
PubMed1978

[Ultrastructural and functional features of the reversibility of sclerotic liver changes in rats treated with exogenous organ specific RNA].

Ultrastructural peculiarities of hepatocytes and Kupffer's cells in rats during the spontaneous reversibility of the experimental cirrhosis of the liver under the usual conditions and also under the influence of exogenous RNA, administered by different methods, were studied. The changes in cell ultrastructure proved to correlate with those of the quantitative indices of the protein synthesizing the liver function during the hepatic cirrhosis reversibility. A positive role of the RNA influence of short duration on the intracellular reparative hepatocytes regeneration, and a negative one in case of RNA influence of long duration was revealed. Participation in the resorption of collagen both of the parenchymal cells and of the stroma was shown.

Animals↗
PubMed1977

[Effect of triton WR 1339 on the ultrastructure of liver parenchymal and stromal cells in rats with chronic toxic hepatitis].

A preliminary injection of triton WR 1339 protectively influenced the chronic toxic CCl4-hepatitis. The ultrastructural peculiarities were close to the normal ones in hepatocytes, in addition to the increased triglyceride rejection from cells by means of autophagy. The revealed stimulation signs of pinocytosis in hepatocytes and the Kupfer cells are accompanied by the activation of the Golgi complex and, probably, by the increased protein catabolism in lysosomes. The signs of phagocytosis increase in the Kupfer cells were determined. It is supposed that the marked ultrastructural peculiarities of liver cells reflect a more effective restoration or a lesser injury under the influence of triton WR 1339.

Animals↗
PubMed1977

[A substrate-type induction of liver microsomal monooxygenases by phenobarbital].

A possibility of step-wise induction of microsomal monooxygenases after injection of phenobarbital in the presence of 3-methylcholanthrene-caused induction was studied. It was found that the ratio of the high- and low-spin types of cytochrome, rather than the position of the CO-peak of its reduced form is a criterion for functional specificity of hemoprotein. Induction by phenobarbital appears possible under conditions when the inductor binding to microsomal hemoprotein is lacking, since cytochrome P-488 has no binding sites for phenobarbital. It is assumed that under microsomal monooxygenases induction by phenobarbital activation of genome and subsequent protein synthesis are operated by the substrate rather than by products of its primary metabolism in microsomes.

Animals↗
PubMed1976

[Ultrastructural changes in mucosa of the distal portion of the large intestine of patients with dysentery].

The ultrastructure of the mucosa of the large intestine was studied in 10 patients with acute dysentery. The group of patients included 7 women and 3 men aged 17--50 years. Diagnosis was confirmed in all cases bacteriologically (by isolation of Sonne shigella in 4 patients and Flexner shigella in 6 patients). The electron-microscopy study of bioptats of the mucosa showed that in the inflammatory process all its cells--prismatic, gobletcells, and enterochromaffin -- took part, although not in the same degree. Early appearance of a great number of prismatic cells with a high functional activity indicated to compensatory abilities of the mucosa already during the first days of the disease.

Adolescent↗