The aim of this study was to evaluate the in vitro and in vivo effects of the new chemotherapy agent Casiopeina III-ia [(4,4'-dimethyl-2,2'-bipiridine)(acetylacetonate) Copper (II) nitrate] on HCT-15 (p53-/-) colon cellular line. In vitro, the drug reduced the viability and induced necrosis and apoptosis in a dose dependent manner, without affecting cell cycle phases. Apoptosis was related to Bax increasing levels, suggesting a caspase-dependent mechanism of death, as verified by nucleosomal fragmentation of DNA. In vivo, the antitumor activity of Casiopeina III-ia was tested in HCT-15 cells transplanted to nude mice. In this study we will show that the novel antineoplastic agent Casiopeina III-ia is active on this colon tumor line, setting out as a good candidate for the treatment of colon tumors refractory to chemotherapy.

The bat Corynorhinus mexicanus provides an interesting experimental model for the study of epididymal sperm maturation because after spermatogenesis and the regression of the testes, this bat stores sperm in the epididymal cauda for several months. Earlier research conducted by our group suggested that sperm maturation in this species must be completed in the caudal region of the epididymis. One of the major signal transduction events during sperm maturation is the tyrosine phosphorylation of sperm proteins. The aim of the present study was to comparatively evaluate tyrosine phosphorylation in spermatozoa obtained from the caput, corpus and cauda of the epididymis during the sperm storage period. The maturation status of the sperm was determined by the percentage of capacitation and tyrosine phosphorylation in sperm obtained from the epididymis. The highest proportion of tyrosine phosphorylation was registered after the sperm had reached the cauda epididymis during the middle of the storage period. In conclusion, in Corynorhinus mexicanus and most likely in other chiropteran species with an asynchronous male reproductive pattern, epididymal sperm maturation ends in the caudal region of the epididymis and is related to the time that the sperm remains in the epididymis before mating activity.

SummaryMalnutrition is distributed widely throughout the world and is a particular problem in developing countries. Laboratory animals have been very useful in studying the effects of varying levels of malnutrition because non-nutritional factors that affect humans may be controlled. The objective of the present study was to determine the effects of moderate and severe malnutrition on lymphocyte proportions and activation markers of T cells in experimentally malnourished rats during lactation by flow cytometry. Lower absolute (total) and relative (%) numbers of CD3 + and CD4 + lymphocyte subpopulations were observed in moderately (second degree) and severely (third degree) malnourished rats compared with well-nourished rats (P < 0·05). Both groups of malnourished rats showed a significant decrease in the percentage of CD71 + cells at 24 h post-activation with phytohaemagglutinin (PHA). After 24 h activation of spleen cells with PHA, a lower percentage of CD25+ cells was observed in malnourished than well-nourished rats (P < 0·05). In conclusion, the results of this study indicated an altered expression of CD71 and CD25 during activation of T lymphocytes in malnourished rats and may partially explain increased susceptibility to infection associated with malnutrition. Moreover, these results demonstrated that moderate malnutrition affects the response of T lymphocytes as much as severe malnutrition.

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Objectives: There is growing evidence of the relationship between sleep and the immune response. Studies aimed at elucidating the function of rapid eye movement (REM) sleep have found it difficult to separate the effects due to REM sleep deprivation and the effects due to the stress produced by the deprivation procedure. It has been claimed that immobilization is the main stressor that the animals have to face during the deprivation process. In this study, we analyzed the effects of short-term (24 h) and long-term (240 h) REM sleep deprivation on the distribution of lymphocyte subsets in the peripheral blood of rats. In addition, these effects were compared with those obtained after both short- and long-term stress by immobilization. Methods: Lymphocyte population bearing surface markers such as CD5 (T cells), CD45RA (B cells), CD4 (T helper/inducer cells), CD8 (T suppressor/cytotoxic cells) and CD161 (NK cells) were analyzed using monoclonal antibodies. Lymphocyte subsets were assessed by flow cytometry. Results: Both short- and long-term REM sleep deprivation decreased the percentage of T lymphocytes and induced a significant increase in NK cells. Short-term immobilization induced only a significant increase in the percentage of B lymphocytes and a decrease in the percentage of T lymphocytes, while long-term immobilization did not elicit any change. Conclusion: The present results support the notion that REM sleep deprivation and immobilization stress each exert particular effects on the immune system. These data suggest that the characteristics of the immune response will depend on the nature of the behavioral manipulation.

During seed germination, metabolism is reactivated, DNA is repaired and cell division is restarted in the meristems. The mechanisms that co-ordinate cell growth and division in maize embryonic axes during germination are not well understood. However, the presence of a factor similar to IGF (insulin-like growth factor) that accelerates germination has been reported. In the present work, the regulation of the cell-cycle restart by bovine insulin [which has been demonstrated to produce similar effects as insulin-like growth factor of maize (ZmIGF) in maize seeds] was studied in germinating embryonic axes. Our results showed that bovine insulin differentially stimulates growth, S6K phosphorylation, S6rp transcript accumulation on the polysomal fraction, as well as de novo DNA synthesis in the radicles and the coleoptiles of the embryonic axis. A stronger and earlier effect was observed in radicles compared to coleoptiles; therefore, the effect of insulin on the cell cycle of the root meristem was studied by flow cytometry. The G1–S transition was stimulated and cell proliferation was induced. Furthermore, it was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) that bovine insulin increased E2F and PCNA (proliferating cell nuclear antigen) transcription after 15 h of germination and PCNA de novo synthesis at 15 h of germination. These results show that bovine insulin preferentially stimulates growth in the radicles of germinating embryonic axes and suggest that its effect on the G1–S transition and the activation of cell proliferation is mediated by the induction of E2F and PCNA transcription.

The Corynorhinus mexicanus bat provides an interesting experimental model for the study of epididymal sperm maturation because after testicular regression, this bat stores sperm in epididymal cauda for several months. Earlier research conducted by our group suggested that sperm maturation in this specie must be completed in the caudal region of the epididymis, although the precise factor linked with this phenomenon is unknown. Therefore, the aim of this work was to analyze changes in the distribution of N-acetylglucosamine and/or sialic acid, Fucose and Mannose carbohydrates in different membrane domains of sperm cells as they change from the caput to the cauda of the epididymis, as well as, their changes in different dates of capture. The sperm cells present a redistribution of N-acetylglucosamine and/or sialic when they arrived in the caudal region (September 11), but after storage until October 22 the distribution of N-acetylglucosamine and/or sialic acid changed. Mannose residues were found predominantly towards the acrosome during their entry into and transit through the three regions of the epididymis. The flow cytometry assay indicated that fluorescence intensity due to the presence of of N-acetylglucosamine and/or sialic acid on the sperm decreases as the sperm pass through the epididymal duct and as storage time in the cauda goes on. The Mannose fluorescence intensity, decreased in corpus and cauda from September 24 to October 8, though no differences appeared on the latter date. The presence of Fucuse was corroborated only by flow cytometry. In conclusion, the carbohydrate distribution on sperm membrane can be considered as part of the process of epididymal sperm maturation and is associated with the phenomenon of prolonged sperm storage that is characteristic of this specie. This adaptation allows the males to synchronize with the period of receptivity of the females, and then, carry out the matings.

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