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I V Markelova

Publications and source records attributed to I V Markelova.

14 recordsLinked to original sources
PubMed1981

[Comparison of the level of epithelial cell proliferation in the liver, islands of Langerhans and pancreatic acini of mice from the age and individual viewpoints].

The index of labelled nuclei (ILN) was determined in the mouse liver and pancreas epithelium within 24 hrs following five injections of 3H-thymidine. Five age groups were studied with the mean weight 15, 19, 20.4, 24.3, and 28.2 g. The ILN was equal in hepatocytes, respectively, to 5.2, 0.6, 0.03, 0.13 and 0.02%, in pancreatic islet cells to 4.6, 4.1, 1.7, 1.5, and 0.7%, and in acinar cells to 0.4, 1.1, 0.07, 0.30, and 0.10%. Marked individual ILN variations were observed. In hepatocytes the highest ILN in each age group correlated positively with maximal absolute liver weight and, in four groups, with its maximal relative weight. The maximal ILN indices did not coincide for the three cell types. A suggestion is put forward on relationship between ILN fluctuations and unequal character or organ growth and asynchrony of growth of different organs.

Aging↗
PubMed1976

[Human oogenesis in organ culture].

The authors compared the extent of development of the germ cells of the human fetus ovaries developing in the organ culture and of control ovaries obtained of fetuses of "equivalent" age. The capacity to enter the meiosis prophase under conditions of the organ culture was expressed by the germ cells of fetuses of 8-9 week of gestation, and older; only individual oocytes reached the leptotene stage in the explants of the ovaries of 7-8 week fetuses. The oocytes at the leptotene, zygotene and pachitene stage appeared in the culture at the same periods as in the organism. However, the percentage of cells of these stages in the explant was as a rule lower than in control ovaries. In case of pulse administration of thymidine-3H into the culture labeled oocytes at the zygotene stage appeared in 4, and at the pachitene stage - in 14 days.

Female↗
PubMed1976

[Autoradiographic study of the early stages of human female meiosis in organ culture].

Incorporation of H3-thymidin in developing germinative cells and the movement of the label in successive stages of preprophase and prophase of meiosis were studied in the organic culture of the ovaries of 7-12 and 23 week human embryos by the method of autoradiography. H3-thymidin was incorporated by oognia and oocytes of the last stages of preleptotene with a thin uneven network of chromatin in the nucleus and by oocytes of the stage of leptotene and, rarely, zygotene. In oocytes with prochromosomes the label appeared within 12 hours. The cells labeled in the premeiotic DNA synthesis were changed into the zygotene stage within 4 days, into the pachytene stage- within 14 days. The development took 7-14 days from the last premitosis S-period to zygotene. Oogoniums divided two times for 7 days. Gz-period of oognia -1/2 of mitosis lasts an average of 10 hours. The S-period of oogonia lasts for about 9 hours.

Female↗
PubMed1975

[Diurnal variations in the duration of mitosis in the mouse esophageal epithelium].

Considerable differences were found in the morning and the evening mitotic indices of the epithelium in the oesophagus of C57BL/6J mice. By the colchamin method it was shown that the duration of mitosis was the same in the morning and the evening hours and was equal to 34--49 minutes. The results varied and depended on the dose of colchamin and duration of its action. Thus, the diurnal differences in mitotic index of the epithelium in the oesophagus depended on the differences in mitotic activity, the number of mitoses per time unit. It is emphasized that colchamin method should be used with great caution to obtain reliable results.

Animals↗