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Biomedical subjects

V L Bykov

Publications and source records attributed to V L Bykov.

At least 91 records · Page 5Linked to original sources
PubMed1978

Quantitative histochemical and stereological study of alkaline phosphatase in the rat thyroid gland.

The histochemical alkaline phosphatase reaction in thyroid vascular endothelium was estimated spectrophotometrically and stereologically. Thus two main characteristics of the reaction were obtained: 1. the average enzyme activity, reflecting the level of transport processes in the capillary-thyrocyte system; 2. the relative volume of functioning vessels. An index of thyroid vascularity is proposed that is equal to the product of these two characteristics. The changes of the primary characteristics as well as of the vascularity index, caused by experimental hypo- and hyperplasia of the gland, are discussed.

Alkaline Phosphatase↗
PubMed1978

[Rhythmicity of structural components of the thyroid gland at different stages of postnatal ontogenesis (morphometric study)].

Age evolution of biological rhythms in the activity of the thyroid gland has been studied at organic, tissue and cellular levels. The thyroid glands have been studied in 144 male mice, A/He strain, of three age groups: 14--17-day-old (young premature), 55--60-day-old (mature) and 160--170-day-old (ageing animals). The mean height of follicular cells, stereological index of resorption, relative volumes of follicular and interfollicular epithelium, colloid and stroma have been considered, as well as relations of volumetric fractions in certain tissue components. The data obtained have been processed with a computer. Multicomponent character of the rhythms for all indices studied has been revealed, circadian, ultradiurnal and infradiurnal components including. Spectral analysis of the rhythms has revealed steady tendency towards decreasing relative power of ultradiurnal fluctuations with age while circadian rhythmics become more pronounced. Amplitude of the circadian component of all the rhythms studied increases with growth and development of the animal and decreases for a number of indices in ageing mice. Maximal activity of the organ, as stated the data of morphometric analysis, in all three groups corresponds to the night time.

Age Factors↗
PubMed1977

[Age and biorhythms of the histophysiologic indices of the thyroid gland].

Rhythmic changes of several histophysiological parameters of the thyroid gland was studied in 144 A/He mice of three age groups: young immature, mature adults and ageing animals. The multicomponent nature of the rhythmic changes was found for each index; it included the circadian component, as well as infradian oscillations. The leading role of the circadian component in the establishment of the biorhythms of the organ functioning was shown, whereas ontogenetic changes were chiefly associated with the ultradian components' attenuation.

Age Factors↗
PubMed1976

[Age and changes in the thyroid gland of A/He mice (morphometric and histochemical studies)].

Changes in the thyroid gland of mice A/He in postnatal ontogenesis were studied at the age of from 1 to 547 days by methods of morphometry and quantitative histochemistry. During the first days of life an active growth of the organ, accumulation of colloid, increase of the relative volume of the follicular epithelium in which the intensity of the histoenzymological reactions increased were observed. In the period of sex maturation the excretion of colloid was noticed as well as an increase of the height of follicular cells with activation of some of their enzymatic systems. Later on, while aging, the follicular cells gradually become flatter, the level of some enzymatic reactions of thyrocytes drops, the relative volume of colloid increases and its histochemical properties change. In the gland of animals older than 6-7 months well pronounced cystic changes were found.

Aging↗
PubMed1976

[Method of natural periodization of processes].

The method of natural periodization of processes based on objective quantitative account of the dynamics of changing of certain parameters is described. The natural periodization has been established by analysis of the data dynamic series, the distribution of observation terms being made with regard for the a priori taken rate of changes of the parameters under study. The possibility to compare different parameters has been achieved by using centrated approximated data. The discovering of natural periods can be performed by analysis of the group of centrated data. The variation of the variation coefficient of centrated ordinates in each temporal point can be calculated for objectivization of the evaluation. The investigation of developmental changes of the thyroid of A/H mice with employment of methods of morphometry and quantitative histochemistry is taken as an example.

Age Factors↗
PubMed1975

[Morphometric study of the thyroid gland].

The article surveys the most important morphometric methods used for investigating the thyroid gland. Applicability of various histophysiological criteria for evaluation of the functional state of the organ and investigation of changes in its individual structural components in physiological and pathological processes is discussed. The connection between various quantitative indices and the most rational morphometric techniques based on the methods of planimetry and stereology are considered.

Anatomy↗
PubMed1975

[Method of complex morphofunctional study of the capillary bed of the thyroid gland].

The method is based on the cytospectrophotometric estimation of the histochemical reaction to alkaline phosphatase in the gland capillary and on determination of the relative volume occupied by the functioning capillaries. A model experiment under conditions of hyperplasia and hypoplasia of the organ has shown considerable differences in the gland blood supply. Under these conditions the changes of the functioning capillary bed were more pronounced than those of the organ mass.

Alkaline Phosphatase↗
PubMedDate not supplied

Velocity of Candida albicans invasion into host tissues.

Using 2 experimental models (candidal vaginitis in leukopenic mice and oral candidosis in neonatal rats) characterized by minimal inflammatory response to the pathogen, the rate of invasive growth of Candida albicans in stratified epithelia of mucosal membranes was defined. The pseudomycelium was found to invade animal epithelia at an average rate of 2 microns per hour, penetrating the entire epithelial thickness during 24-48 h. These data have been extrapolated to clinical pathology. On the basis of experimental data and by measuring the epithelial thickness in some human mucous membranes, the presumable periods of total epithelial penetration were calculated which may lead to vascular invasion and create the danger of dissemination. For different human mucous membranes these periods ranged from 22 to 59 h. These data emphasize the importance of cellular and tissue defense mechanisms, the inhibition of which may allow the fungi normally found on epithelial surfaces as commensals to invade the host tissues and to cause deep and disseminated mycotic lesions within several days.

Adult↗
PubMedDate not supplied

Histopathology of human vaginal candidosis.

Histological changes of vaginal and ectocervical mucosa in women of reproductive age suffering from vaginal candidosis are described. The epithelial surface is covered with adherent masses composed of desquamated and destroyed epithelial cells and leucocytes impregnated with proteinaceous fluid 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 superficial epithelial layers. The barrier between the invading pseudomycelium and the blood vessels of the lamina propria papillae in some sites is only 5 to 6 flattened epithelial cells thick. In the basal epithelial layer, increased mitotic activity is noted. Lamina propria contains lympho-plasmocytic infiltrates. The problems of pathogenesis and diagnosis of vaginal candidosis are discussed in connection with the present findings.

Adult↗
PubMedDate not supplied

Histopathology of experimental vaginal candidosis in immunosuppressed mice.

The histopathology of vaginal candidosis was studied in cyclophosphamide (CY)-immunosuppressed mice. In severely leucopenic animals acutely treated with high doses of CY the fungal inoculation resulted in a massive invasion of the pathogen, which penetrated the whole thickness of vaginal wall and was able to spread further into the surrounding tissues. In some animals, a haematogenous dissemination of the infection was detected. In mice chronically treated with lower doses of CY, moderate leucopenia combined with impaired antifungal granulocyte activity and suppressed cellular immunity resulted in the development of only superficial mycotic lesions. Pathogenetic mechanisms of vaginal candidosis in immunocompetent and immunosuppressed hosts are discussed.

Animals↗
PubMedDate not supplied

Thermoradiotherapy combined with a proteolysis inhibitor (contrical) in the treatment of head and neck cancer.

For the prophylaxis of head and neck cancer recurrence and metastases we used radiation therapy, microwave hyperthermia and adjuvant therapy (inhibitor of proteolysis contrical and alpha-interferon). One hundred forty patients with primary cancer were treated. After 1 year of observation time and absence of tumor the patients were examined once every 3 months. The use of contrical and interferon combined with radiation therapy and microwave hyperthermia increased the 3-year survival rate by 37%, the number of patients without recurrence by 39% and decreased the appearance of regional metastases to 8.4%. Adjuvant therapy is discussed.

Aprotinin↗
PubMedDate not supplied

[Human gingival immunocompetent cells in the norm and in inflammatory periodontal diseases].

The review describes characteristics of gingival immuno-competent cells (lymphocytes, macrophages, dendritic antigen-presenting and plasma cells), forming a unified system and interacting with each other in physiological conditions and in inflammatory processes. The role of microbial factors and immunocompetent cell dysfunction in the development of destructive changes in periodontal tissues is analyzed. Gingival mast cell, fibroblast and epitheliocyte participation in immune reactions is discussed.

Antigen-Presenting Cells↗
PubMedDate not supplied

[A cytomorphological analysis of the adhesion of fungi of the genus Candida to human and animal epithelial cells].

Morphological pattern of adherence of Candida genus fungi to human and animal epithelial cells have been studied using histological and cytological methods. The interspecific differences of epithelial adhesive properties were observed: in one case, the mucous membrane epitheliocytes of different localization had different adhesive properties. Adhesive properties vary significantly within one type of epithelial cells. In individual epitheliocyte, the adherence of fungal blastospores was nonuniform: the greater density was observed in peripheral areas of cytoplasm.

Animals↗
PubMedDate not supplied

[Analysis of plasma fibrinogen in evaluating the effectiveness and prognosis of polyradiomodifying therapy of malignant tumors of the upper respiratory tract].

Patients with malignant tumors of the upper respiratory tract showed higher concentrations of fibrinogen in plasma the level of which was correlated with the stage of disease. Measurements of the protein in the course of radiation therapy demonstrated that two months after effective treatment fibrinogen concentrations decreased to normal values and remained at that level throughout the remission time. If radiation therapy was ineffective, fibrinogen concentrations remained high during 2 to 4 months after exposure. Metastases and recurrent tumors caused a drastic increase in the fibrinogen content, the change occasionally occurring prior to clinical manifestations. In view of this, plasma fibrinogen can be recommended as an additional measure that can be used to evaluate therapy effectiveness, to prognose the course of disease and to identify metastases in patients with malignant tumors of the upper respiratory tract.

Brachytherapy↗