Effects of lanosterol on in vitro maturation of porcine oocytes

[EN] FF-MAS and T-MAS sterols, intermediaries in the cholesterol biosynthetic pathway present in all cells, may represent the physiological signal that instructs the crocyte to reinitiate meiosis. The purpose of this study was to examine the hypothesis that exogenous lanosterol could be included in the sterol biosynthetic pathway from acetate to cholesterol and induce resumption of meiosis in oocytes cultured in vitro. Porcine oocytes were in vitro matured in medium supplemented with different concentrations of lanosterol. First, after 22 h of in vitro maturation, cumulus cells were recovery and Delta 7-Reductase gene expression was quantified using real-time PCR. Second, after 44 h of in vitro maturation, chromatin configuration was evaluated using Hoechst 33342. Lipid content was also evaluated at 22 and 44 In of in vitro maturation using Nile red staining. The results showed that the addition of lanosterol increased the Delta 7-Reductase gene expression and influenced resumption of meiosis using 50 and 100 mu M, as well as enhancing higher cytoplasmic lipid accumulation after in vitro maturation. The results demonstrate that exogenous lanosterol acts in the sterol biosynthetic pathway from acetate to cholesterol and it was responsible for a higher resumption of meiosis in porcine oocytes cultured in vitro. (C) 2009 Elsevier B.V. All rights reserved.Supported by the Universidad Politecnica de Valencia (Project 20081166).Marco Jiménez, F.; Llobat, L.; Vicente Antón, JS. (2010). Effects of lanosterol on in vitro maturation of porcine oocytes. Animal Reproduction Science. 117(3-4):288-294. https://doi.org/10.1016/j.anireprosci.2009.04.008S2882941173-

Extra- and intra-ovarian factors in polycystic ovary syndrome: impact on oocyte maturation and embryo developmental competence

background: Polycystic ovary syndrome (PCOS) is a common metabolic dysfunction and heterogeneous endocrine disorder in women of reproductive age. Although patients with PCOS are typically characterized by increased numbers of oocytes retrieved during IVF, they are often of poor quality, leading to lower fertilization, cleavage and implantation rates, and a higher miscarriage rate. methods: For this review, we searched the database MEDLINE (1950 to January 2010) and Google for all full texts and/or abstract articles published in English with content related to oocyte maturation and embryo developmental competence. results: The search showed that alteration of many factors may directly or indirectly impair the competence of maturating oocytes through endocrine and local paracrine/autocrine actions, resulting in a lower pregnancy rate in patients with PCOS. The extra-ovarian factors identified included gonadotrophins, hyperandrogenemia and hyperinsulinemia, although intra-ovarian factors included members of the epidermal, fibroblast, insulin-like and neurotrophin families of growth factors, as well as the cytokines. conclusions: Any abnormality in the extra- and/or intra-ovarian factors may negatively affect the granulosa cell-oocyte interaction, oocyte maturation and potential embryonic developmental competence, contributing to unsuccessful outcomes for patients with PCOS who are undergoing assisted reproduction.Obstetrics & GynecologyReproductive BiologySCI(E)PubMed49REVIEW117-331

Estimating rural-urban nutrient flows for mega-cities

In Drechsel, P.; Kunze, D. (Eds.). Waste composting for urban and peri-urban agriculture: closing the rural-urban nutrient cycle in Sub-Saharan Africa. Colombo, Sri Lanka: International Water Management Institute (IWMI); Rome, Italy, FAO; Wallingford, UK: CAB