205 research outputs found

    Pre-maturation with cAMP modulators in conjunction with EGF-like peptides during in vitro maturation enhances mouse oocyte developmental competence

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    Recent studies have independently shown that cyclic adenosine 3'5'-monophosphate (cAMP) modulation prior to in vitro maturation (IVM) and epidermal growth factor (EGF)-like peptide supplementation during IVM improve subsequent oocyte developmental outcomes. This study investigated the effects of an IVM system that incorporates these two concepts. Cumulus-oocyte complexes (COCs) were collected from pre-pubertal mice either 46 hr post-equine chorionic gonadotropin (eCG) (IVM) or post-eCG + post-human chorionic gonadotropin (hCG) stimulation (in vivo maturation; IVV). IVM COCs were treated with the cAMP modulators forskolin and IBMX for 1, 2, or 4 hr (pre-IVM phase) prior to IVM. COCs then underwent IVM with the EGF-like peptides amphiregulin or epiregulin, or with the common IVM stimulants follicle-stimulating hormone (FSH) or EGF. A pre-IVM phase increased the size of the subsequent blastocysts' inner-cell-mass compared to standard IVM, regardless of IVM treatment (P < 0.05). Unlike FSH or EGF, amphiregulin or epiregulin significantly increased blastocyst quality (trophectoderm and total cell numbers) and/or yield (P < 0.01) compared to standard IVM, and were the only treatments that produced blastocysts comparable to IVV-derived blastocysts. Forskolin acutely up-regulated EGF-like peptide mRNA expression after a 2-hr pre-IVM phase (P < 0.001), although EGF receptor and ERK1/2 activities were not significantly different than control. IVV-like levels of EGF-like peptide mRNA expression during IVM were maintained only by supplementing with EGF-like peptides and EGF, since expression levels induced by FSH were significantly lower in vitro than during IVV. However, EGF receptor and ERK1/2 phosphorylation levels were not significantly different across treatment groups. In conclusion, a pre-IVM phase in conjunction with IVM in the presence of EGF-like peptides endows high oocyte developmental competence, as evidenced by increased embryo yield and/or quality relative to FSH and EGF.D. Richani, X. Wang, H. Zeng, J.E.J. Smitz, J.G. Thompson, and R.B. Gilchris

    Pioneering contributions by Robert Edwards to oocyte in vitro maturation (IVM)

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    The history of in vitro maturation (IVM) of mammalian oocytes, especially of human oocytes, holds a special place for Robert Edwards. He was the first to comprehensively examine and demonstrate maturation of human oocytes in vitro and in so doing he changed the course of medicine by fertilizing them in vitro. In reviewing his contribution, we have examined the state of the field at the time and discuss his pioneering insights into mammalian oocyte biology. We will also discuss how some of the major concepts and challenges identified by Edwards 50 years ago remain among the major challenges facing IVM today.J.G. Thompson and R.B. Gilchris

    La stomatodynie.

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    International audienc

    Critères diagnostiques des douleurs idiopathiques orofaciales.

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    International audienc

    Méthodes de contrôle de la douleur dentaire chez l’enfant.

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    International audienc
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