Cytofluorometric study of the glycogen content in DNA-synthesizing and -nonsynthesizing hepatocytes in the regenerating liver

Using a combined cytochemical method that allows to determine glycogen, DNA and 3H-thymidine label in the same cell, glycogen amounts were measured both in 3H-TdR-marked and non-marked hepatocytes of the regenerating 3H-thymidine. During mitosis, the glycogen amount is reduced if compared with that in cells being in presynthetic phase. It is proposed that the decrease in glycogen content in the regenerating liver may partly depend on energetic expenses of cells that started DNA synthesis and mitotic division. The phenotypic expression of genes responsible for glycogen synthesis and splitting in di-, tetra- and octoploid hepatocytes of the regenerating liver liver was proportional to the corresponding values.     

Effect of emotionality, exploratory activity and pain sensitivity on manifestation of agonistic behavior in the mouse

Mice of C57BL/6J line with higher exploratory and motor activities and with lower emotionality and pain threshold recorded in standard tests, as compared with the animals of CBA/Lac line, have also been found to manifest a more expressed aggression in their intermale contacts in reaction to a syngeneous partner. It is suggested that the studied physiological and behavioural parameters may determine in considerable degree the character of aggressive and submissive mice behaviour in an agonistic interaction.     

Electron microscopic study of the interaction of virulent and avirulent Shigella flexneri strains with the macrophages of murine peritoneal exudate

The electron microscopic dynamic study of the interaction of S. flexneri virulent strain 2a and S. flexneri avirulent strain, genetically related to strain 2a and having the same antigenic structure, with peritoneal macrophages of CBA mice at an early period showed differences in the cytotoxic action of these strains. Even at the early period of the interaction between macrophages and virulent shigellae structural changes were observed in macrophages: ruptures in the membranes of parasitophore phagosomes, the vacuolization of the cytoplasm, the destruction of mitochondria. These changes were indicative of the early cytotoxic action of shigellae belonging to the virulent strain. In macrophages infected with avirulent shigellae the manifestations of this cytotoxicity were less pronounced and appeared later than in macrophages infected with S. flexneri virulent strain.     

Change in the dry weight of hepatocytes during chronic intoxication of rats with CCl4

Dry weigHT of rat hepatocytes (DWH) was measured microinterferometrically during a chronic CCl4 intoxication. Following a long chronic intoxication of rats by hepatotropic poison results in the increase in DWH by 63%. The increase in the DWH due to CCl4 intoxication may be associated either with cell hypertrophy or with the cell polyploidy, depending on the test animal. Thus the trigger mechanisms of hypertrophy or polyploidy in cell population are not identical. It is supposed that the hypertrophy of hepatocytes accompanying liver cirrhosis is perhaps one of the mechanisms involved in the normal cell reparative reaction on the increased organ functioning.     

Fractionation of stable sulfur isotopes during microbiological processes in Slavyansk lakes]

The isotopic content of sulphur in sulphates increases with depth in waters containing hydrogen sulphide of the meromictic lakes Repnoe and Veisovo as a result of microbiological reduction of sulphates. At the same time, hydrogen sulphide enrichments 19 to 25% of the light isotope 32S in the lake Veisovo, and 24 to 32% in the lake Repnoe. The fractionation of sulphur isotopes, manifested in the enrichment of sulphides with lighter isotopes, and that of sulphates with heavier isotopes, was found also in the bottom deposits of the lake Repnoe. The isotope and microbiological data suggest that, in the zone of mass growth of the phototrophic sulphur bacteria in the lake Repnoe, there are two processes of fractionation: (a) due to the bacterial reduction of sulphates; and (b) due to anaerobic oxidation of hydrogen sulphide, resulting in the enrichment of hydrogen sulphide with the light isotope 32S by 5 to 7 promille.