You searched for:"Márcia Marly Winck Yamamoto"
We found (5) results for your search.Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2021;43(6):480-486
The process of ovulation involves multiple and iterrelated genetic, biochemical, and morphological events: cessation of the proliferation of granulosa cells, resumption of oocyte meiosis, expansion of cumulus cell-oocyte complexes, digestion of the follicle wall, and extrusion of the metaphase-II oocyte. The present narrative review examines these interrelated steps in detail. The combined or isolated roles of the folliclestimulating hormone (FSH) and luteinizing hormone (LH) are highlighted. Genes indiced by the FSH genes are relevant in the cumulus expansion, and LH-induced genes are critical for the resumption ofmeiosis and digestion of the follicle wall. A nonhuman model for follicle-wall digestion and oocyte release was provided.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2012;34(7):344-344
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2010;32(11):541-548
DOI 10.1590/S0100-72032010001100005
PURPOSE: to reassess the adrenal function of patients with PCOS after the introduction of the Rotterdam's criteria. METHODS: descriptive and cross-sectional study including 53 patients 26±5.1 years old. Glucose, glycosylated hemoglobin, lipids, estradiol, progesterone, 17-OHP4, DHEAS, FSH, LH, TSH, PRL, androstenedione, free thyroxine, insulin, total testosterone, SHBG, and free androgen index were measured. Insulin resistance was considered to be present with a homeostatic model assessment index >2.8. The adrenal response to cortrosyn was assessed by the hormonal rise observed at 60 minutes, and by the area under the response curve. RESULTS: biochemical hyperandrogenism was found in 43 of 53 eligible patients (81.1%). Thirty-three women had adrenal hyperandrogenism (62.2%). The weight of these 33 women, aging 25.1±5.0 years, was 74.9±14.9 kg, BMI was 28.8±6.0 and the waist/hip ratio was 0.8±0.1. DHEAS was >6.7 nmol/L in 13 (39.4%) and androstenendione was >8.7 nmol/L in 31 (93.9%). The increments in 17-OHP4, cortisol, A, and progesterone were 163%, 153%, 32%, and 79%, respectively. The homeostatic insulin resistance model was >2.8 in 14 (42.4%). Insulin and estradiol were not correlated with cortisol or androgens. CONCLUSIONS: the use of multiple endocrine parameters showed a high prevalence of biochemical hyperandrogenism in patients with PCOS. Two thirds of the patients had adrenal hyperandrogenism, and estradiol and insulin did not influence adrenal secretion.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2007;29(1):48-55
DOI 10.1590/S0100-72032007000100008
Changes in the levels of gonadotropins throughout the reproductive life depend on a fine tuned functional development of neural pathways and GnRH-neurones, pituitary gonadotrophs and granulosa-theca cells of the follicular wall. Both, LH and FSH levels change according to the day-time, menstrual cycle phase, and gynecological age. Initiating the puberty, changes in LH pulses are remarkable, showing higher frequency and amplitude at night. Later in puberty, the pulses of LH are also maintained during the day, remaining its levels with very little variation within the 24 hours period. During the menstrual cycle, the FSH levels increase at the end of the luteal phase, decrease during the medium and late follicular phase, increase rapidly in the ovulatory phase and remain at low basal levels until the late luteal phase. The levels of LH remain unaltered during the whole follicular phase, increase in the ovulatory surge, and decrease to the basal levels in the luteal phase. At the forth decade of life, the GnRH secretion changes, with hypothalamic loss of sensitivy to the estradiol positive feedback and decrease in frequency and prolongation of the GnRH pulses. The pituitary response is atenuated due to decrease in the density of GnRH receptors on gonadotroph cells, loss of gonadotroph sensitivity, secretion of more basic FSH and LH molecules, decrease in frequency and increase in amplitude of LH and FSH pulses. These modifications result in monotropic increase of the FSH secretion. Current studies show that the selective increase in the FSH levels in the early follicular phase is gradual, beginning as early as the third decade of life. These alterations in FSH are associated with an accelerated follicular depletion in women after 37-38 years old. On the other side, the LH levels remain almost constant up to the end of reproductive life. The different levels of FSH and LH seen throughout the reproductive years may be due to yet unknown regulatory mechanisms in the hypothalamic-pituitary-ovarian axis.