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Biomedical subjects

L F Stebaeva

Publications and source records attributed to L F Stebaeva.

At least 19 recordsLinked to original sources
PubMed1991

[Effectiveness of dioxidine in a model of Staphylococcal necrotic-suppurative encephalomeningitis (according to electron microscopy data].

Dioxidine efficacy was studied on a model of staphylococcal necrotic suppurative encephalomeningitis. There was a relationship of the development of disease signs to the value of the contaminating dose. Dioxidine was shown to have a therapeutic effect. Purulent inflammation in the brain either undevelop or was more limited. Examination of the changes in the ultrastructure of the nervous tissue also confirmed the efficacy of dioxidine. The treated mice had single inflammation infiltrations in the presence of the intact structure of the nervous tissue, the cell composition of the infiltrations changing in the direction of predominance of the mononuclear phagocytes. The phagocytes were in the state of hyperactivity and phagocytosis was of the completed nature. Secondary phagocytosis of the phagocytes and cell detritus was recorded.

Animals↗
PubMed1990

[Effects of quinolone carboxylic acid derivatives on the ultrastructure of gram-positive and gram-negative bacteria].

The impact of oxolinic acid, pefloxacin and ciprofloxacin on the structure of Staphylococcus aureus, Pseudomonas aeruginosa and Serratia marcescens was studied. The concentration dependent effects were revealed. Comparative estimation of the action of the compounds by the content of normal, dead and changed cells in the cultures showed that ciprofloxacin had advantages. The results of the pefloxacin use were close. The time course of the oxolinic acid effect was analogous whereas the changes in the cells induced by the acid were less pronounced. Investigation of the ultrastructural changes demonstrated that the response of the gram-negative bacteria to the action of the compounds was of one type. There was noted formation of filamentous structures and vacuolized cells at low concentrations and large egg-shaped cells at high concentrations of the compounds. In the gram-positive bacteria there were detected large cells with much thicker cell walls at low concentrations of the compounds while at the high concentrations the cell walls were on the contrary thinner, the cell stiffness was lost and the cells acquired a festoon-like shape. The compounds induced significant changes in the nucleoids, cell walls and membranes. Along with insignificant changes in the nucleoid structure there were constantly detected coarse impairments of the cell walls and membranes which should be considered in estimating the effect of the quinolone carboxylic acid derivatives.

Ciprofloxacin↗
PubMed1981

[Structural changes in renal tissue in experimental staphylococcal septicopyemia].

The structure of the kidney tissue in mice with staphylococcal septicopyemia due to intraperitoneal introduction of Staph. aureus in various doses was studied. It was found that the level of acute purulent inflammation in the kidney tissue was different depending on the site of the affection: the purulent component predominated in the cortical layer, while the necrotic component in the medullary layer and papillae. The most gross changes in the glomerular filter developed in the presence of a swarm of staphylococci and deposition of electron-dense material in the basal capillary layers. It is noted that the study on the ultrastructural changes in the kidney tissue makes it possible to use them for estimation of highly active antibacterial agents.

Animals↗
PubMed1975

[Characteristics of the vascular-capillary network and the relationship between capillaries and cells in the nucleus of Luys in the cat during postnatal ontogenesis].

The development of the Luy's nucleus of the cat is not accomplished by birth-time. Complex relationships between nerve cell and capillaries continue to change during postnatal ontogenesis. The function of the Luy's nucleus becomes perfect by the third month. It should be noted that maturation of nerve cells and the vascular network goes not in parallel: the enlargement of the nerve cell occurs smoothly while the increase of the vascular-capillary network density is undulatory. There are three peaks in the development of vascular-capillary network: the 20th day, one month and a half, adult cat.

Age Factors↗
PubMedDate not supplied

[The effect of spirobromin and prospidin on acute and chronic inflammation in rats].

The effects of new antitumor drugs spirobromin and prospidin on acute (carraghenin-induced rat paw edema) and chronic ("pellet granuloma") inflammation in rats were studied. The drugs were found to exert the anti-inflammatory effect on the model of chronic proliferative inflammation but to produce no significant changes in the degree of the acute inflammatory reaction. Spirobromin is superior to prospidin by the power of the anti-inflammatory effect. The electron microscopic studies showed that spirobromin and prospidin decrease the activity of fibroblasts in the focus of chronic inflammation.

Animals↗
PubMedDate not supplied

[Study of the effect of dioxidine on the subcellular fractions of microbial cells].

Penetration of dioxidine to the cells of Staphylococcus aureus and the drug effect on subcellular fractions were examined. High pressure liquid chromatography demonstrated that after penetration to the cells of Staphylococcus aureus dioxidine was found unchanged in the cytoplasmic fraction. Differences were disclosed in the biochemical action pattern of the drug on the growing and stationary culture. Exposure of the growing culture to dioxidine resulted in an appreciable decrease in the protein and especially in nucleic acid levels, in significant changes in the composition of the intracellular protein complex. The drug produced structural alterations within the cell wall. These alterations increased with concentrations and were characterized by the loosening of the wall and by the membrane release.

Bacterial Proteins↗
PubMedDate not supplied

[Effect of riodoxol on herpes simplex virus morphogenesis in experimental eye infection].

The effect of riodoxol on herpes simplex type 1 viruses was studied. It was shown to affect multiplication and maturation of the virus as manifested in the appearance of virions with incomplete nucleoid structure and long-term presence of virions in cytoplasmic vacuoles in cells. Submicroscopic changes suggest a dual effect of riodoxol on herpes simplex virus: on the DNA replicative cycle and on the stage of late maturation of virus at the time of its release from the nucleus.'

Animals↗
PubMedDate not supplied

[Electron microscopic studies of experimental staphylococcal infections in mice as chemotherapeutic models].

Study of ultrastructural changes in the brain and renal tissues has shown that both intracerebral and intraperitoneal administration of staphylococcus in low infecting doses leads to the development in the brain and renal tissues of acute purulent inflammation, with a dramatic growth of infectious process and involvement of all parts of the organs under consideration. The presence in the brain tissues and in its meninges of inflammatory pyonecrotic foci might attest to the necrotic purulent encephalomeningitis, whereas the presence in the cortex and renal medullary substance of histiolymphocytic infiltration and foci of necrosis might be evidence of necrotic glomerulonephritis of bacterial etiology.

Animals↗
PubMedDate not supplied

[Mechanism of the antiherpetic action of bonafton].

The mechanism of antiherpetic action of bonaphthon was studied in experimental herpetic keratitis of rabbits infected with herpes simplex type I virus (Koptev and IC strains). Electron microscopy demonstrated that the drug inhibits herpes virus production and proliferation of virus infection because of partial impairment of the nucleocapsid "assembly" in the cell nucleus. It is assumed that the action of bonaphthon may be consequent on the inhibition of the cell synthesis of cytoplasmatic proteins incorporated into the capsids and on the derangement of the transport of virus capsid components to the cell nucleus, where these components are assembled. It has been shown that the intensity of virus reproduction in the cells decreases threefold under the effect of bonaphthon as compared to control.

Animals↗