[Peculiarities of pre- and postnatal kidney development in vasopressin-deficient brattleboro rats].

The objective of this study was to examine pre- and postnatal development of the kidney in vasopressin-deficient Brattleboro rats in comparison as compared to that in Wistar rats. Histological, histochemical and morphometric methods at light microscopic level were used. The study included 50 fetuses at gestational days 16 and 18, and 46 rat pups at postnatal days 5, 10, 20, and 30. It was found that nephrogenesis sequence in both rat strains was similar, however, Brattleboro embryos and infant rats were characterized by an accelerated growth of renal corpuscles and renal tubules. The results suggest that vasopressin has no direct effect on the formation of nephron structural elements, however it may participate in the regulation of hyaluronan biosynthesis in the renal medullary interstitial tissue involved in the mechanism of urine osmotic concentration.

Statistical analysis of clone formation in cultures of human stem cells.

We performed a statistical analysis of clone formation from aneuploid cells (chromosomes 6, 8, 11, X) in cultures of bone marrow-derived human multipotent mesenchymal stromal cells by spontaneous level of aneuploidy at different terms of culturing (from 2 to 19 cell cycles). It was found that the duration of cell cycle increased from 65.6 h at passages 2-3 to 164.5 h at passage 12. The expected ratio of aneuploid cells was calculated using modeled 5, 10, 20 and 30% selective preference in reproduction. The size of samples for detecting 10, 25, and 50% increased level of aneuploidy was calculated. The presented principles for evaluation of aneuploid clone formation may be used to distinguish clones of any abnormal cells.

[Exocrinocytes of the gastric mucosa epithelium of Siberian chipmunk under different seasonal conditions].

The objective of this study was to analyze the morpho-functional remodeling of the epitheliocytes of stomach fundic glands in Siberian chipmunk under different seasonal conditions. The methods of light and electron microscopy were used. It was shown that during summer period, the structure of gastric fundic mucosa of Siberian chipmunk was similar to that one in other mammals. In contrast, in winter, during the periods of hypothermia, the cells of the fundic glands in the gastric corpus demonstrated the changes indicative of the suppression of their secretory activity. During the spontaneous arousals, all the elements of the gastric glands were activated, while the animals consumed the stored food. The present results were compared with the materials obtained earlier in the study of ground squirrels which also have a period of winter hibernation. Gastric cell remodeling in chipmunks during hypothermia was comparable in its trend with the changes taking place in ground squirrels, however, these changes were more pronounced in the latter. Food digestion in the stomach of chipmunk took place not only during the periods of normothermia, but also in the course of slow decline of the body temperature, when animals fell into a state of torpidity, and it recommenced at the early stages of animal rewarming during frequent episodes of its spontaneous arousal. Differences in the changes found in chipmunks and ground squirrels are associated with ecological peculiarities of these species and in the characteristics of the adaptation during the winter period.

[Optimization of anesthesiological maintenance of x-ray surgical interventions in children]. / Optimizatsiia anesteziologicheskogo obespecheniia rentgenokhirurgicheskikh vmeshatel'stv u detei.

Two procedures for intravenous anesthesia during X-ray surgical interventions were evaluated in 38 children aged 3 to 13 years. Initial anesthesia (with intramuscular midazole and ketamine), followed by the fractional use of the latter agents in Group 1 and propofol in Group 2, in order to maintain anesthesia. Blood pressure (BP) (noninvasively), heart rate (HR), SpO2, and respiratory rate (RR) were monitored. After the initial anesthesia, mean BP (BPmean) increased by 40 and 24% in Groups 1 and 2, respectively. So did HR by 23 and 31%, respectively. In Group these changes retained throughout the basic stage of intervention. In Group 2 on propofol infusion, BPmean and HR returned to normal values and remained at this level till the end of the intervention, SpO2 and RR did not differ from the baseline values in both groups. Thus, a combination of intravenous ketamine and intramuscular propofol provides steady-state values of BP and HR at the basic state of X-ray surgical intervention in children, which increases the reliability of studies and surgical safety in patients.

Serotonin-producing cells in duodenum of Siberian chipmunk under various seasonal conditions.

We studied species-specific characteristics of enterochromaffin cells in the duodenum in Siberian chipmunk in various physiological states. Predominance of synthetic or secretory phase in enterochromaffin cell activity depends on body temperature, metabolism, and feeding behavior.

[The morphometric characteristics of the serotonin-producing cells of the intestines in the red-cheeked suslik during its spontaneous arousal]. / Morfometricheskaia kharakteristika serotoninprodutsiruiushchikh kletok kishechnika krasnoshchekogo suslika v khode ego spontannogo probuzhdeniia.

Duodenal serotonin-producing cells of the hibernating rodent (Citellus erythrogenys Brandt) were studied at its spontaneous arousal. Morphometric analysis of EC cells revealed alterations in endoplasmic reticulum and Golgi complex changes of numeral density and ratio of different types of ribosomes, retardation of granule content resorption at the spontaneous arousal of the animal. It is concluded that synthetic processes in EC-cells are rapidly activating, which probably restores the serotonin reserves, necessary for the normal course of hibernation.

[The pepsinogen of the gastric mucosa in the red-cheeked suslik Citellus erythrogenys]. / Pepsinogen slizistoi obolochki zheludka krasnoshchekogo suslika Citellus erythrogenys.

Studies have been made on the isozymic composition of pepsinogen (polyacrylamide gel electrophoresis) and peptidase activity in gastric mucosa of the ground squirrel at various stages of hibernation. Eight pepsinogen isoforms were found in acid-producing zone of the mucosa, pyloric mucosa lacks first three of them, its peptidase activity being two times lower than in other parts of the stomach. During hibernation, no significant changes were found in fractional composition of pepsinogen, peptidase activity being decreased twofold only in the fundulus of the stomach, remaining practically constant in other parts of the latter. This finding indicates that the stomach is ready for the activity irrespectively of food uptake.

[Serotonin-producing cells during normo- and hypothermia]. / Serotoninprodutsiruiushchie kletki v periody normo- i gipotermii.

Ultrastructure of the serotonin-producing (EC) duodenum cells of a hibernant in euthermia (in summer and winter) and hypothermia has been studied. It has been found that EC cells of an active summer and spontaneously arousal animals belong to active population. This cells have protein-synthetic activity. The winter cells are characterized by the deficiency of the synthetic processes and the secretory granules disintegration. The results support the hypothesis that ES cells are an important element in the regulation of the hibernation.

Mitotic activity of stomach epithelium in the ground squirrel, Citellus erythrogenys Brandt.

1. During hibernation the epithelial cells of the stomach in ground squirrels divide upon spontaneous emergence from hibernation. In torpor periods, mitoses are blocked up. 2. In animals which have come out of hibernation in spring, one peak of mitosis has been recorded in the first few hours after emergence, and another 3 or 4 days later. 3. In summer the mitotic index is low.

[Seasonal dynamics of the gastric APUD cell count in a hibernator]. / Sezonnaia dinamika chislennosti apudotsitov zheludka gibernanta.

Light microscopy was applied to study variation in the composition and number of apudocytes in the gastric epithelium of red-cheeked sousliks over time. During hibernation, the content of serotonin-producing EC cells was elevated. This is in agreement with serotonin involvement in the maintenance of the hibernation state. The number of non-EC cells taking part in digestion, which does not occur during hibernation, was lowered. Spring awakening was accompanied with an increase in the number of non-EC cells and the lack of significant changes in cells. In souslics, which were active in winter, the content of non-cells was high, since the animals continued feeding on, and the content of EC-cells was elevated similarly to that in hibernating animals, which could be explained by genetic dependence. The number of apudocytes in the gastric mucosa was discovered to correlate in the main with the features of their function at different seasons.