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Biomedical subjects

V L Bykov

Publications and source records attributed to V L Bykov.

At least 55 records · Page 3Linked to original sources
PubMed1990

[The morphogenesis of candidiasis of the mucous membranes after the administration of immunodepressants].

Influence of the immunosuppressants on the development and course of the experimental candidiasis was studied using the model of the murine vaginitis. As distinct from the mice with an intact immune system in which the fungi penetrate into the mucous membrane epithelium only superficially and are rapidly destroyed by the neutrophil granulocytes, the administration of immunosuppressants results in the penetration of the pseudomycelium through the epithelium and its invasion into the lamina propria, vessels and (in some cases) the development of the hematogenic dissemination. Tissue protective reactions are totally inhibited after the administration of high doses and partly depressed and inefficient after moderate doses of immunosuppressants.

Animals↗
PubMed1989

[Morphological analysis of the effect of corticosteroids on the development and course of vaginal candidiasis].

Specific features of the development and course of vaginal candidiasis were examined in corticosteroid-treated mice. Corticosteoids enhance epithelial adhesion of fungal cells and contribute to rapid invasion of the causative agent. Tissue inflammatory response in slow and weak. Pseudomycelium penetrates deep into Malpighi's layer, and, at some sites, damages the epithelial basal layer and invades the mucosal plate. In some animals, vascular invasion led to hematogenic dissemination. The described tissue and cellular mechanisms must be the basis of the stimulating effect of corticosteroids on vaginal candidiasis in the humans.

Adhesiveness↗
PubMed1989

[Histologic diagnosis of African histoplasmosis (the first case of the disease in the USSR)].

The findings obtained from histological examination of a biopsy specimen enabled a case of African histoplasmosis to be first recorded in the USSR. The disease was detected in an African student who had had a long-term latent period. The diagnosis was culturally and clinically verified. The problems of the histological differential diagnosis of African histoplasmosis are also discussed.

Adult↗
PubMed1989

[Morphohistochemical and electron microscopic characteristics of malignant tumors of the upper respiratory tract after combined local hyperthermia and radiotherapy].

The paper discusses morphohistochemical and electron microscopic characteristics of 15 primary tumors of the upper respiratory tract removed following preoperative irradiation in combination with local hyperthermia as a radio-modifying factor. Eighteen tumors removed after irradiation alone served as controls. Application of local microwave hyperthermia resulted in a higher degree of irreversible tumor cell dystrophia and damage. Hyperthermia--induced damage included disorders in ultrastructure of intracellular membranes and cell organelles mainly due to derangement of membrane--binding proteins, protein--lipid and nucleotide complexes. Thermoradiotherapy stimulated protective reaction of surrounding tissue which took the form of increase in fraction of leukocytes and macrophages with high acid phosphatase level in areas of tumor cell damage.

Adult↗
PubMed1988

[Experimental study of the effect of corticosteroid preparations on the adhesion of Candida genus fungi to the epitheliocytes of mucous membranes].

The effect of corticosteroids on the adherence of Candida cells to epithelial cells was studied with the use of the original modification of the in vitro adherence assay. The administration of hydrocortisone acetate to mice resulted in the increased adherence of the pathogenic fungi to epithelial cells: after 10-day hormone treatment the adherence number and the adherence index increased, respectively, to 230% and 360% of control values. After 20-day treatment these characteristics increased, respectively, to 260% and 700%. The adherence of C. albicans to vaginal epithelial cells in female mice receiving corticosteroids increased in comparison with that in the control animals at estrus: the adherence number increased to 220% and the adherence index, to 470% of the level observed in the controls.

Animals↗
PubMed1988

[Pathohistological characteristics of vaginal candidiasis in women of reproductive age].

Histological changes of vaginal mucosa and portio vaginalis are described in women of reproductive age suffering from candidosis. The epithelial surface is covered with adherent masses composed of desquamated and destroyed epithelial cells and leukocytes impregnated with proteins and penetrated by pseudomycelium. The outer epithelial layers are characterized by dystrophic and necrobiotic changes, desquamation, formation of fissures and small cavities. Pseudomycelium penetrates 4 to 6 layers of the epithelium. The barrier between the invading pathogen and the blood vessels of the lamina propria papillae in some sites is only 5-6 flattened epithelial cells thick. In the basal layer, high mitotic activity is noted. Lamina propria contains lympho-plasmocytic infiltrates.

Adult↗
PubMed1987

[Role of opportunistic fungi in human pathological anatomy].

The role of opportunistic fungi (OF) in modern human pathology is discussed in connection with the increased incidence of mycotic infections caused by these organisms. Due to a complex of biological properties, OF are able to survive both in the environment and in human body, exhibiting their pathogenic potential when the body defenses are compromised. The highest frequency of infections caused by OF is encountered in the presence of risk factors (immunodeficiencies, endocrinopathies, oncological and hematological diseases, organ transplantation, antibiotic and corticosteroid therapy, infancy and pregnancy). The spectrum of lesions caused by OF encompasses practically all organs and systems. Being a secondary process, mycotic infection may either have no influence on the primary process, or aggravate it. In most severe cases it may overbalance the importance of the underlying disease. Cytohistological methods play a special role in the diagnosis of mycotic infections, as they are able to reveal the invasive process, evaluate its extent and the characteristics of host defense responses.

Anti-Bacterial Agents↗
PubMed1987

[Changes in the adhesion of Candida fungi to the epithelium during the menstrual cycle].

Changes in the adhesion of Candida cells to the mucous membrane of the oral cavity were studied in vitro in experiments with epithelial cells from 12 normal women at various stages of the menstrual cycle. Fungal cells more actively adhered to the epithelial cells obtained at the follicular phase of the menstrual cycle than to those obtained at its luteal phase. At the follicular phase, both the average level of adhesion and the population of epithelial cells with most pronounced adhesive properties increased. The range of variations in adhesion levels was different in individual subjects and varied from 8% to 37% of the individual mean of the whole cycle. The results of this study indicate the existence of the hormonal control of the adhesion of Candida cells to human epithelial cells.

Adult↗
PubMed1987

[Cytohistologic and ultrastructural characteristics of the early stages of the interaction of Candida with epitheliocytes].

Cyto-histological and ultrastructural features of the initial stages of the interaction between Candida cells and epitheliocytes of human and animal mucous membranes were studied in vitro and in vivo. The population of epitheliocytes is heterogeneous in its adhesive properties, 15-20% of cells being several times more adhesive than the rest of the population. Within an individual epitheliocyte the adhesion of blastospores was nonuniform, the majority of the latter attaching to the periphery of the cell and to the intercellular boundaries. This was found in cytological smears, histological film preparations and in SEM micrographs, and was also confirmed by the results of morphometric analysis. Ultrastructural analysis has revealed two phases of the interaction between Candida blastospores and epitheliocytes during adhesion, as well as the cytological effect of the fungal cells.

Animals↗
PubMed1987

[Experimental candidiasis of the digestive organs in newborn animals].

Morphogenesis of alimentary tract candidosis was studied in the experimental neonate model. The infection was characterized by rapid progression, multiorgan involvement and weak cellular responses. Most commonly the oral cavity and esophagus were the sites of superficial lesions, while the stomach of deep ones. The penetration of the mucous membrane by fungal elements and the vascular invasion resulted in some cases in hematogenous dissemination of the infection.

Animals↗