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.