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Biomedical subjects

N I Shevchenko

Publications and source records attributed to N I Shevchenko.

8 recordsLinked to original sources
PubMed1991

[An electron microscopic study of the effector link in immune reactions in stomach cancer].

21 surgically removed gastric carcinomas of different histologic structure and stage of development were studied ultrastructurally. A variety of morphological manifestations of local immune reactions and nonspecific antitumour resistance were observed. These manifestations were characterized by the contacts of lymphocytes, macrophages, polymorphonuclear leukocytes, plasma cells with each other and with tumour cells and by the presence of variable changes in tumour cells. The causes of such a variety are discussed and they may be due to different types of cytotoxicity, stage of the interaction between the effector and the target and so on.

Cell Communication↗
PubMed1990

[Ultrastructure of breast cancer vessels].

Vascular bed of the infiltrating mammary gland carcinomas characterized by the incomplete maturity, atypia and polymorphism is studied electron microscopically. Two groups of vascular structures were investigated: avascular part represented by pseudovessels and vascular part with protocapillaries, capillaries, sinusoids and venulae that are distinguished by their morphofunctional properties and the degree of maturity. The vascular bed is characterized by a structural and functional heterogeneity. Ultrastructural properties characterizing the stages of the vascular bed morphogenesis are presented: angiogenesis activation, relative vascular differentiation and regression of some parts which occur asynchronically and are due to the properties of the stromal parenchymal relations in different microareas, and to the heterogeneity of the tumour on the whole.

Adult↗
PubMed1979

[Degree of maturity and histogenesis of stomach cancer and their importance for prognosis].

The intensity of differentiation of adenocarcinoma and non-differentiated cancer cells was studied histochemically and electron microscopically. A higher ratio of nucleus volume to cytoplasm volume and nucleus nuclei acids to cytoplasm RNA, low secretory activity in adenocarcinoma cells as compared to nondifferentiated cancers were found. Adenocarcinomas were shown to have a higher activity of NADP-dependent dehydrogenases, more numerous free ribosomes as compared to nondifferentiated carcinoma. This suggests a lower degree of cell differentiation and high proliferative activity in adenocarcinomas than in nondifferentiated carcinoma. Differences in the intensity of cell and tissue differentiation in adenocarcinomas and nondifferentiated carcinoma and due to differences in their histogenesis and must be taken into account in evaluations of the prognosis.

Adenocarcinoma↗
PubMed1978

[Ultrastructural characteristics of renal cancer cells].

The ultrastructural study of the renal carcinoma revealed some differences in the fine structure of the two main cell types: clear and dark cells. The cytoplasm of clear cells is rich in fat and glycogen. Fat is found in lipid vacuoles and glycogen in diffuse granularity in the cell cytoplasm. Dark cells contain small amounts of fat and glycogen but have well developed mitochondria and other organelles. Comparison of these cell types shows some features of their similarity such as microvilli on the cell surface, desmosomes and interdigitations in the region of cell contacts and channels between tumour cells. These features suggest that clear and dark cells have a common origin from the epithelium of the proximal tubules.

Adenocarcinoma↗