Otávio Mitio Ohashi

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The caprine ovary is a rich source of potentially viable immature oocytes enclosed in preantral follicles (PF). Previous experiments showed that these oocytes can be successfully cryopreserved in ovarian tissue of several species. However, until now, no information about the caprine PF cryopreservation is available in the literature. The aim of the present(More)
BACKGROUND Melatonin inclusion into in vitro oocyte maturation (IVM) protocols has been suggested because it possesses a powerful free radical scavenger capability that improves the quality of the oocyte used in in vitro embryo production (IVP). The aim of our study was to investigate the presence of melatonin membrane receptors (MT1and MT2) and MT3, which(More)
Nitric oxide (NO) is a cell-signaling molecule that regulates a variety of molecular pathways. We investigated the role of NO during preimplantation embryonic development by blocking its production with an inhibitor or supplementing in vitro bovine embryo cultures with its natural precursor, L-arginine, over different periods. Endpoints evaluated included(More)
The aim of the present study was to determine the most desirable ovarian tissue section thickness to isolate preantral follicles (Experiment I), determine follicular density (follicles/mm(2) of cortex) of ovaries of fetal buffalo of different ages (Experiment II), and cultivate preantral follicles of buffalo fetuses (Experiment III). In Experiment I, ovary(More)
Studies in somatic cells have shown that glucocorticoids such as dexamethasone (DEX) may trigger or prevent apoptosis depending on the cell type in culture. Because the dysregulation of apoptosis may lower in vitro embryo production efficiency, we sought to investigate the effects of supplementing IVC medium with DEX (0.1 μg/mL) on embryo morphology,(More)
The aim of this research was to perform in situ quantification, morphometry evaluation, and apoptosis analysis of ovarian follicular wall cells in mechanically isolated follicles obtained from ovaries of bovine fetuses (Bos taurus indicus) between 3 and 9 months of age. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase-mediated dUTP(More)
Cryopreservation of ovarian tissue may be a potential alternative for the conservation of genetically superior animals, including high milk- and meat-producing goat breeds. However, until now, no information was available concerning the cryopreservation of preantral follicles (PF) enclosed in caprine ovarian tissue. The objective of the present study was to(More)
The aim of this study was to evaluate whether an in vitro culture (IVC) medium containing either or not β-mercaptoethanol (BME), bone morphogenetic protein 4 (BMP4), or pregnant mare serum gonadotrophin (PMSG) could be able to promote the development of capuchin monkeys' preantral follicles enclosed in ovarian cortical strips. Follicular viability after IVC(More)
There is no tradition in studies reporting the effect of exposure to cryoprotectants or simply hypoxia and hypothermia on gene expression in the ovarian tissue and there has been only one study on reference or target genes quantification, and comparisons of normoxic with hypoxic, hypothermic and toxic conditions. Our aim in the present study was to(More)
Adult stem cells are known for their plasticity and their potential to differentiate into several different cell types; these characteristics have implications for cell therapy and reproductive biotechnologies. In this study, we report on the isolation and characterization of mesenchymal stem cells (MSC) derived from bovine and buffalo adipose tissue. Cells(More)