Search results for "Gonadotropin-releasing hormone"
showing 10 items of 52 documents
Similar endometrial development in oocyte donors treated with either high- or standard-dose GnRH antagonist compared to treatment with a GnRH agonist…
2005
Background This descriptive study evaluates the impact on endometrial development of standard and high doses of a GnRH antagonist in stimulated cycles compared with GnRH agonist and natural cycles. Methods Thirty-one oocyte donors were treated with a combination of rFSH and 0.25 mg/day ganirelix (standard dose), 2 mg/day ganirelix (high dose) or 0.6 mg/day buserelin (long protocol). Vaginal progesterone (200 mg/day) was administered in the luteal phase. Endometrial biopsies were performed 2 and 7 days after HCG administration. Additional biopsies were carried out in a subset of 12 subjects, 2 and 7 days following the LH peak of their previous natural cycle. Biopsies were evaluated histologi…
Pretreatment with gonadotropin-releasing hormone (GnRH) antagonists to prevent the flare-up effect of long-acting GnRH agonists: results of a pilot s…
2007
This study evaluated in vivo whether the flare-up effect of GnRH agonists can be suppressed through pretreatment with a GnRH antagonist. The classic flare-up effect caused by 3.8 mg goserelin acetate could not be suppressed through pretreatment using a single dosage of 3.24 mg cetrorelix acetate.
The role of gonadotropin-releasing hormone in murine preimplantation embryonic development.
1999
Previous studies have established the presence of an extrahypothalamic GnRH in a variety of tissues. GnRH receptor is known to be present in the placenta, which produces and secretes the decapeptide from the very early stages of placentation. We hypothesized that GnRH may play a role in the preimplantation development of embryos. To examine this hypothesis, we assessed GnRH and GnRH receptor messenger RNA (mRNA; RT-PCR) and protein expression (Immunohistochemistry) in preimplantation murine embryos at various developmental stages. Furthermore, preimplantation murine embryos were cultured with GnRH agonist and antagonist in vitro to assess the influence of GnRH analogs on embryo development.…
Hormonal and metabolic adaptation to fasting: effects on the hypothalamic-pituitary-ovarianaxis and reproductive performance of rabbit does
2006
To assess the impact of acute caloric shortage on reproduction, rabbit does were either fed ad libitum (control, AL), or fasted for 24 (STF) or 48 h (LTF) before induction of ovulation with GnRH injection. Blood samples were collected during the last 3 h of fasting, and the following 4 h after GnRH injection, when feed was provided again, to measure plasma concentrations of LH, estradiol-17β, leptin, insulin, T3, corticosterone, glucose, and NEFA. Before re-feeding, plasma leptin, insulin, and T3 concentrations were lower (P ≤ 0.01) in both fasted groups than in controls, but then gradually increased following realimentation to match those of controls. During fasting, corticoster…
Gonadotropin-releasing hormone agonist for the prevention of chemotherapy-induced ovarian failure in patients with lymphoma: 1-year follow-up of a pr…
2013
PURPOSE To assess the efficacy of gonadotropin-releasing hormone agonist (GnRHa) in preventing chemotherapy-induced ovarian failure in patients treated for Hodgkin or non-Hodgkin lymphoma within the setting of a multicenter, randomized, prospective trial. PATIENTS AND METHODS Patients age 18 to 45 years were randomly assigned to receive either the GnRHa triptorelin plus norethisterone (GnRHa group) or norethisterone alone (control group) concomitantly with alkylating agents containing chemotherapy. The primary end point was the premature ovarian failure (POF) rate (follicle-stimulating hormone [FSH] ≥ 40 IU/L) after 1 year of follow-up. Results Eighty-four of 129 randomly assigned patients …
Neonatal Outcomes and Long-Term Follow-Up of Children Born from Frozen Embryo, a Narrative Review of Latest Research Findings
2022
In recent years, the growing use of ART (assisted reproductive techniques) has led to a progressive improvement of protocols; embryo freezing is certainly one of the most important innovations. This technique is selectively offered as a tailored approach to reduce the incidence of multiple pregnancies and, most importantly, to lower the risk of developing ovarian hyperstimulation syndrome when used in conjunction with an ovulation-triggering GnRH antagonist. The increase in transfer cycles with frozen embryos made it possible to study the effects of the technique in children thus conceived. Particularly noteworthy is the increase in macrosomal and LGA (large for gestational age) newborns, i…
Hypogonadism in β-thalassemic adolescents: A characteristic pituitary-gonadal impairment. The ineffectiveness of long-term iron chelation therapy
1990
The pituitary-gonadal function was studied in 18 beta-thalassemic female adolescents, 8 with delayed puberty and 10 with primary amenorrhea,treated with repeated transfusions and long-term iron chelation therapy by subcutaneous infusion. A 100 micrograms gonadotropin-releasing hormone (GnRH) test, a double-bolus GnRH test after estradiol administration in non-responders, a 400 micrograms thyrotropin-releasing hormone (TRH) test and a 'high dose' human menopausal gonadotropin (hMG) test were performed. LH and FSH peak levels were significantly lower in thalassemic patients than in controls, both in the 100 micrograms GnRH test (LH was 4.3 +/- 0.7 mIU/ml vs 40.8 +/- 6.0 mIU/ml and FSH 3.3 +/-…
Melatonin modulates diacylglycerol and arachidonic acid metabolism in the anterior pituitary of immature rats.
1990
In pituitary glands of immature rats prelabeled in vitro with [3H]arachidonic acid, melatonin diminished the luteinizing hormone-releasing hormone (LHRH)-induced increase in [3H]diacylglycerol accumulation as well as [3H]arachidonic acid release from the tissue. Melatonin reduced also LHRH-stimulated incorporation of [3H]glycerol into pituitary [3H]diacylglycerol. The effect was day-time dependent: in the evening experiment melatonin was effective at 0.1 nM concentration while in the morning it had no effect even at 10 nM concentration. The effect of melatonin was also abolished by pretreatment with pertussis toxin. Diacylglycerol and/or arachidonic acid might serve as 2nd messengers transd…
Serum luteinizing hormone in patients undergoing ovarian stimulation with gonadotropin-releasing hormone antagonists and recombinant follicle-stimula…
2004
The serum LH was determined on days 3, 6, and 8 of stimulation and on the day of hCG in 110 normogonadotropic patients undergoing controlled ovarian hyperstimulation (COH) for IVF induced with GnRH antagonists and recombinant FSH, creating three groups of patients according to Tukey's hinges (percentiles 25 and 75) for each determination. No differences were observed between the number of oocytes recovered or the fertilization, implantation, and pregnancy rates (PR) of the groups, although patients with high serum LH levels during stimulation showed significantly higher serum E2 levels on the day of hCG.
The effect of cancer treatment on female fertility and strategies for preserving fertility.
2006
Aggressive chemotherapy and radiotherapy in young patients with cancer has greatly enhanced the life expectancy of these patients, but these treatments often cause infertility because of the massive destruction of the ovarian reserve resulting in premature ovarian failure (POF). This review focuses on the effect of cancer treatments on fertility and on the various surgical and assisted-reproduction innovations that are available to provide the patient with the option of future pregnancies. As the emerging discipline of fertility preservation is steadily attracting increasing interest, developments in the near future promise to be very exciting. However, in everyday routine work, better inte…