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Biomedical subjects

I A Morozov

Publications and source records attributed to I A Morozov.

At least 19 recordsLinked to original sources
PubMed1992

[The permeability of the barrier of the gastrointestinal tract for the macromolecules of polyethylene glycol-4000: an assessment of the mechanism and its reproducibility].

Polyethylene glycol (PEG)-4000 is proposed as a tracer of intestinal macromolecular permeability. The reproducibility of permeability testing with PEG-4000 and the mechanism of its penetration through intestinal mucosa were studied in adult rats. Permeability measurement for PEG-4000 was reproducible when repeated twice for 2 days. This makes it possible to repeat PEG-4000 permeability testing before and after any experimental impact on the intestine. I.p. administration of colchicine to rats (125 micrograms/100 g b. w.) significantly inhibited intestinal absorption of PEG-4000 fed to the animals 3 hours later. Hence, PEG-4000 penetration through the intestinal mucosa is mediated by the system of enterocyte cytoplasmic microtubules. Mucosal permeability for PEG-4000 may be consequently considered as a valuable model of permeability for protein macromolecules.

Animals↗
PubMed1991

[Differentiation of strains of bovine infectious rhinotracheitis virus using restriction analysis].

The virus of infectious rhinotracheitis of cattle (BHV-1) causes the respiratory diseases, encephalitis, vulvovaginitis, abortions, etc. in sensitive animals. The attempts to differentiate the viral strains by virology and serology methods were unsuccessful. The restriction analysis makes possible to divide the strains into the three main groups designated BHV-1.1, BHV-1.2 and BHV-1.3. Majority of authors note the lack of correlation between the restriction pattern of DNA and the syndromes caused by the strains of the first and second groups while all the representatives of the third group were isolated in case of meningoencephalitis. The restriction analysis of BHV-1 strains isolated in the USSR by restriction endonucleases EcoRI, BamHI, HpaI and ClaI is presented. The obtained results show the absence of correlation between the restriction pattern of the strain and the syndrome caused by the viruses of all three groups. The representatives of the group BHV-1.3 that are not associated with the neurological syndrome are isolated for the first time.

DNA, Viral↗
PubMed1990

[The ultrastructure of the parietal mucosal layer of the small intestine].

With light and electron microscopy structure and composition of the small intestine parietal mucous layer of rat, chicken, and man were studied. It has been shown that parietal layer is complicated and multicomponent system includes mucous glycoproteins, vesicular and membrane structures, epithelial cells fragments, food substrates particles and bacteria. It is assumed that subepithelial mucous layer components may be of significance in premembrane digestion and absorption.

Animals↗
PubMed1990

[The digestive function of the supraepithelial mucosal layer of the small intestine].

The results of biochemical estimation of the activity of intestinal proper and pancreatic enzymes in enteral contents, mucous layer and homogenate of small intestine's membrane suggest an important role of supraepithelial mucous layer in actualization of final stages of the food hydrolysis. The term "parietal digestion" is suggested for designation of a sum of hydrolytic processes in the layer of mucus.

Animals↗
PubMed1990

[Optimal method of isolation of supra-epithelial mucous layer of the small intestine in experimental animals].

Experimental data on the activity of digestive endo- and exo-hydrolases in supra-epithelium mucus layer has been presented. Mucus layer has been obtained on special vibrating setting from the turned out intestinal preparation. Different conditions of work and medium of isolation have been used. The setting permits to obtain intestinal supra-epithelium mucus more completely and also prevents epithelium damages and hiting of damaged villi.

Animals↗
PubMed1990

[The morphology of the secretory process in the gastrin-producing cells of the gastric antrum in patients with hypo- and hypersecretion of HCl].

The level of HCl secretion in humans correlates with the formation of granules and the organoid functional morphology in the gastrin-producing cells (GPC) of antral region of the stomach mucous membrane: HCl hypersecretion is followed by the enhancement of GPC activity, hyposecretion correlates with the inhibition of their activity. The juxtaposition of the GPC functional morphology indexes of the stomach juice acidity and blood gastrin concentration implies the necessity to reevaluate the significance of the latter as an adequate index of the GPC function.

Adolescent↗
PubMed1989

[Gastrin-producing cells of the stomach in duodenal ulcer before and after selective proximal vagotomy].

Morphofunctional state of the gastrin-producing cells in the antral gastric mucosa depending upon the gastric secretion and serum gastrin was investigated in patients with duodenal ulcer before and after the selective proximal vagotomy (SPV). Morphometric analysis of the hormone containing granules in G-cells showed the increase of their functional activity after SPV. It was demonstrated that serum basal gastrin reflects morphofunctional state of the gastrin-producing cells. Functional capabilities of the gastrin regulation of the gastric secretion after the vagus denervation of the acid-producing part of the stomach must be taken into consideration in duodenal ulcer surgery.

Adolescent↗
PubMed1987

[Interaction of s4U8 region of tRNA Phe with tRNA-(adenine-1-)-methyltransferase from Thermus thermophilus].

Photoaffinity labelling of tRNA (adenine-1-)-methyltransferase with an E. coli tRNA(Phe) derivative bearing 4-azidophenylmercuro group attached to s4U residue as well as direct photocross-linking of the native tRNA(Phe) with the enzyme via s4U residue has been studied. Both techniques labelling gave similar results, leading to covalent attachment of tRNA(Phe) to the enzyme within a specific complex. The data obtained indicate unambigously that s4U residue contacts with tRNA (adenine-1-)-methyltransferase within the corresponding specific complex.

Cross-Linking Reagents↗
PubMed1986

[Use of the OTO-method in electron microscopic studies].

The modification of OTO-contrasting method (O-osmium, T-thiocarbohydrazide, O-osmium) allowing one to stain the structures of biological tissue in the process of its fixation is presented. The modification consists of an intermittent treatment of tissues with osmium tetroxide and thiocarbohydrazide after the tissue prefixation. This results in the formation of osmium-thiocarbohydrazide copolymer in form of "osmium black" and high tissue contrast corresponding to the true osmiophilia. The use of this modification permits one to give up an additional slide contrasting with a lead citrate and uranyl acetate.

Animals↗
PubMed1986

[A-like cells of the gastric mucosa as a possible source of prostaglandins].

AL cells of the oxyntic stomach area were studied in rats using ultrastructurometric technique. High-threshold, short-term direct electrical vagostimulation (5 V, 4 msec, 30 Hz, 10 sec) was performed in experimental group of 12 animals. Animals were killed 1, 10 and 30 min after stimulation. High post-stimulation lipolytic activity of AL cells and intensification of "granule autophagy" phenomenon were noted. Our findings as well as the literature data suggest a hypothesis on possible prostaglandin production by AL cells. Direct evidence in favour of this hypothesis is difficult to obtain due to the lack of sufficiently reliable methods of their morphological detection in cells.

APUD Cells↗
PubMed1986

[Dynamics of morpho-functional changes in gastrin-producing cells of the stomach after electric stimulation of the vagus nerve].

In 25 white rats, direct stimulation of the vagus nerve increased the average diameter of secretory granules and decreased their number and volume, thus reflecting the release of gastrin during first 5 min after the stimulation. Subsequent increase in volume of nucleus, nucleolus, endoplasmatic reticulum, mitochondria and Golgi complex suggest rapid activation of hormone synthesis in G cells under vagostimulation. The data obtained allow to revise the existing concepts of gastrin release from cells and of ultrastructural criteria of this process.

Animals↗
PubMed1986

[Features of the ultrastructure of endocrine and immunocompetent cells of the antral portion of the stomach in patients with grade II-III obesity].

All types of endocrine cells that occur in healthy persons were identified in the mucous membrane of gastric antrum of patients with obesity. Ultrastructural changes in endocrine cells in obese patients are suggestive of degenerative processes: in D-, D1- and G-cells these are fatty, P- and EC-cells albuminoid. Endocrine cells containing granules characteristic for cells of several types were found more frequently than in control patients. However such mixed types were observed in the two above groups of endocrine cells. Infiltration of mucous membrane of gastric antrum with lymphocytes and activation of intraepithelial lymphocytes and their interaction with endocrine cells were more pronounced in obese patients.

Adult↗
PubMed1986

[Indices of the functional and secretory activity of EC cells of the stomach of the rat after electric stimulation of the vagus nerve].

Within 1, 5, 10 and 30 min after a direct short-term electrical stimulation of the vagus nerve, the amount of histochemically detectable EC-cells was counted and dynamics of changes in stereometric characteristics of their subcellular organelles were investigated in the antral part of the mucous membrane of the rat stomach. The maximum activation of mitochondria, Golgi complex, nucleus and nucleolus was observed within 1 min. A significant decrease in the volume and number of electron-dense secretum granules accompanied by a rise in number of vacuole-like granules occurred within 10 min, i. e. functional and metabolic activity of serotonin-producing EC-cells after vagostimulation increased earlier than the secretion of this monoamine started. The above changes in EC-cells were not accompanied by changes in their number in antral part. The data obtained elucidate the cellular mechanisms of neurohumoral regulation of secretory and trophic processes in the stomach.

Animals↗