The Experts below are selected from a list of 972 Experts worldwide ranked by ideXlab platform
Giovanni Battista Candiani - One of the best experts on this subject based on the ideXlab platform.
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Secretory changes in preovulatory endometrium during controlled ovarian hyperstimulation with buserelin acetate and human Gonadotropins
Fertility and sterility, 1991Co-Authors: Maurizio Marchini, Luigi Fedele, Stefano Bianchi, Gabriele Angelo Losa, Morena Ghisletta, Giovanni Battista CandianiAbstract:Twenty-one patients with unexplained infertility underwent controlled ovarian hyperstimulation with buserelin acetate and human menopausal and Chorionic Gonadotropins, and follicular growth was monitored by ultrasonography and daily 17 beta-estradiol (E2) assays. Endometrial biopsy was performed when E2 levels were greater than or equal to 250 pg/mL per follicle and the follicular diameter was greater than or equal to 17 mm. As controls, we studied 20 preovulatory endometrial biopsies from patients with a male infertility factor. The biopsy material was examined at light, scanning, and transmission electron microscopes, and a morphometric analysis was performed. Preovulatory endometrial mucosa during controlled ovarian hyperstimulation showed accentuated proliferative aspects in both the glandular and stromal components and more frequent early secretory phenomena compared with the controls. The preovulatory progesterone (P) levels observed in our study seem to exclude the possibility that such early secretory aspects of the hyperstimulated endometrium are because of higher P concentrations in patients compared with controls.
Yves Combarnous - One of the best experts on this subject based on the ideXlab platform.
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Comparative effects of sub-stimulating concentrations of non-human versus human Luteinizing Hormones (LH) or Chorionic Gonadotropins (CG) on adenylate cyclase activation by forskolin in MLTC cells
General and Comparative Endocrinology, 2018Co-Authors: - Thi-mong Diep Nguyen, Danièle Klett, Laura Filliatreau, Yves CombarnousAbstract:We have compared various Luteinizing Hormone (LH) and Chorionic Gonadotropin (CG) preparations from non-human and human species in their ability to synergize with 10 mu M forskolin (FSK) for cyclic AMP intracellular accumulation, in MLTC cells. LH from rat pituitary as well as various isoforms of pituitary ovine, bovine, porcine, equine and human LHs and equine and human CG were studied. In addition, recombinant human LH and CG were also compared with the natural human and non-human hormones. Sub-stimulating concentrations of all LHs and CGs (2-100 pM) were found to stimulate cyclic AMP accumulation in MLTC cells in the presence of an also non-stimulating FSK concentration (10 mu M). Like rat LH, the most homologous available hormone for mouse MLTC cells, all non-human LHs and CG exhibit a strong potentiating effect on FSK response. The human, natural and recombinant hLH and hCG also do so but in addition, they were found to elicit a permissive effect on FSK stimulation. Indeed, when incubated alone with MLTC cells at non-stimulating concentrations (2-70 pM) hLH and hCG permit, after being removed, a dose-dependent cyclic AMP accumulation with 10 mu M FSK. Our data show a clearcut difference between human LH and CG compared to their non-human counterparts on MLTC cells adenylate cyclase activity control. This points out the risk of using hCG as a reference ligand for LHR in studies using non-human cells.
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Use of the immature rat uterotrophic assay for specific measurements of Chorionic Gonadotropins and follicle-stimulating hormones in vivo bioactivities.
Theriogenology, 2010Co-Authors: François Lecompte, E. Harbeby, Claire Cahoreau, Danièle Klett, Yves CombarnousAbstract:The uterine weight growth stimulation by equine Chorionic Gonadotropin (eCG/PMSG) was found to occur at much lower eCG concentrations than ovarian growth. Human Chorionic Gonadotropin (hCG) which has only LH activity, was found to be as active as eCG in the uterotrophic assay whereas equine Luteinizing Hormone (eLH) which has dual LH+FSH activities like eCG, exhibited a much lower potency. In contrast to hCG, porcine and ovine LH as well as pFSH and oFSH exhibited no uterotrophic activity indicating that only Gonadotropins with both LH activity and long half-lives are active alone in this assay. The FSH preparations were nevertheless found to trigger a dose-dependent response, but only in the presence of a subactive dose of hCG. The uterotrophic activity of hCG was found to be suppressed in ovariectomized immature rats and to be diminished after injection of GnRH antagonist suggesting an indirect pathway implicating the hypothalamo-pituitary complex. The data in this report together with the analysis of literature suggest that chorioGonadotropins exert their stimulatory role on uterine growth by an indirect mechanism involving an increase in ovarian FSH receptors and FSH release by the pituitary. At the lowest concentrations of hCG, the increase in ovarian FSH receptors without endogenous FSH release is thought to be responsible for the sensitivity of the uterotrophic assay to exogenous FSHs. In conclusion, the immature rat uterotrophic assay is a sensitive and convenient assay for eCG and hCG as well as for FSHs in the presence of a sub-active dose of hCG.
Maurizio Marchini - One of the best experts on this subject based on the ideXlab platform.
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Secretory changes in preovulatory endometrium during controlled ovarian hyperstimulation with buserelin acetate and human Gonadotropins
Fertility and sterility, 1991Co-Authors: Maurizio Marchini, Luigi Fedele, Stefano Bianchi, Gabriele Angelo Losa, Morena Ghisletta, Giovanni Battista CandianiAbstract:Twenty-one patients with unexplained infertility underwent controlled ovarian hyperstimulation with buserelin acetate and human menopausal and Chorionic Gonadotropins, and follicular growth was monitored by ultrasonography and daily 17 beta-estradiol (E2) assays. Endometrial biopsy was performed when E2 levels were greater than or equal to 250 pg/mL per follicle and the follicular diameter was greater than or equal to 17 mm. As controls, we studied 20 preovulatory endometrial biopsies from patients with a male infertility factor. The biopsy material was examined at light, scanning, and transmission electron microscopes, and a morphometric analysis was performed. Preovulatory endometrial mucosa during controlled ovarian hyperstimulation showed accentuated proliferative aspects in both the glandular and stromal components and more frequent early secretory phenomena compared with the controls. The preovulatory progesterone (P) levels observed in our study seem to exclude the possibility that such early secretory aspects of the hyperstimulated endometrium are because of higher P concentrations in patients compared with controls.
Lijun Huo - One of the best experts on this subject based on the ideXlab platform.
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knockdown of cebpβ by rnai in porcine granulosa cells resulted in s phase cell cycle arrest and decreased progesterone and estradiol synthesis
The Journal of Steroid Biochemistry and Molecular Biology, 2014Co-Authors: Yanhong Zhen, Li Wang, Hasan Riaz, Yifeng Yuan, Li Han, Yanling Wang, Yi Zhao, Yi Dan, Lijun HuoAbstract:Cultured ovarian granulosa cells (GCs) are essential models to study molecular mechanisms of gene regulation during folliculogenesis. CCAAT enhancer binding proteins β (CEBPβ) has been identified in the ovary and is critical for follicular growth, ovulation and luteinization in mice. In the present study, hormonal treatment indicated that luteinizing hormone (LH) and exogenous human Chorionic Gonadotropins (hCG) significantly increased the expression of CEBPβ in porcine GCs. By RNAi-Ready pSIREN-RetroQ-ZsGreen Vector mediated recombinant pshRNA vectors, CEBPβ gene was successfully knocked down in porcine GCs, confirmed by mRNA and protein level analyzed by real time PCR and western blot, respectively. We further found that knockdown of CEBPβ significantly increased the expression of p-ERK1/2. Furthermore, CEBPβ knockdown arrested the GCs at S phase of cell cycle, but had no effects on cell apoptosis. More importantly, it markedly down regulated the concentration of estradiol (E2) and progesterone (P4) in the culture medium. To uncover the regulatory mechanism of CEBPβ knockdown on cell cycle and steroids synthesis, we found that the mRNA expression of bcl-2 (anti-apoptosis), StAR and Runx2 (steroid hormone synthesis) was up-regulated, while genes related to apoptosis (Caspase-3 and p53), hormonal synthesis (CYP11A1) and cell cycle (cyclinA1, cyclinB1, cyclinD1) were down-regulated, suggesting that knockdown of CEBPβ may inhibit apoptosis, regulate cell cycle and hormone secretions at the transcriptional level in porcine GCs. Furthermore, knockdown of CEBPβ significantly increased the expression of PTGS2 and decreased the expression of IGFBP4, Has2 and PTGFR which are important for folliculogenesis in porcine GCs. In conclusion, this study reveals that CEBPβ is a key regulator of porcine GCs through modulation of cell cycle, apoptosis, steroid synthesis, and other regulators of folliculogenesis.
Anita Sit - One of the best experts on this subject based on the ideXlab platform.
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Change in quantitative human Chorionic gonadotropin after manual vacuum aspiration in women with pregnancy of unknown location.
American journal of obstetrics and gynecology, 2009Co-Authors: Veronica Rivera, Phuong H. Nguyen, Anita SitAbstract:Objective To determine whether the change in human Chorionic gonadotropin after manual vacuum aspiration is predictive of an early abnormal intrauterine pregnancy in women with pregnancy of unknown location. Study Design This is a prospective cohort study of 23 clinically stable patients with an early abnormal pregnancy who had abnormally rising human Chorionic Gonadotropins and absence of sonographic evidence of an intrauterine pregnancy or ectopic pregnancy. The change in human Chorionic gonadotropin within 24 hours after manual vacuum aspiration was compared with the pathologic diagnosis and the ultimate clinical diagnosis. Results Ten patients had ≥ 50% decrease (mean, 74%; range, 58-80%) in human Chorionic gonadotropin after manual vacuum aspiration with confirmed Chorionic villi on pathology results. Two patients had a > 50% drop in human Chorionic gonadotropin but absence of Chorionic villi, clinically consistent with complete spontaneous abortion. The remaining 10 patients who had either rising or Conclusion A ≥ 50% decrease in human Chorionic gonadotropin within 24 hours after manual vacuum aspiration is predictive of an abnormal intrauterine pregnancy, thereby excluding an ectopic pregnancy and expediting the management of women with pregnancy of unknown location.