Search results for "Ovulation"
showing 10 items of 127 documents
Aberrant methylation patterns at the two-cell stage as an indicator of early developmental failure
2002
The fertilized mouse egg actively demethylates the paternal genome within a few hours after fertilization, whereas the maternal genome is only passively demethylated by a replication-dependent mechanism after the two-cell stage. This evolutionarily conserved assymetry in the early diploid mammalian embryo may have a role in methylation reprogramming of the two very different sets of sperm and egg chromatin for somatic development and formation of totipotent cells. Immunofluorescence staining with an antibody against 5-methylcytosine (MeC) showed that the incidence of abnormal methylation patterns differs between mouse two-cell embryos from superovulated females, nonsuperovulated matings, an…
Physiology and Pathology of Ovarian Hyperstimulation Syndrome
2010
Ovarian hyperstimulation syndrome (OHSS) occurs when ovaries primed with follicle-stimulating hormone/leuteinizing hormone (LH) are subsequently exposed to human chorionic gonadotropin (hCG). The ultimate pathophysiological step underlying this clinical picture is increased vascular permeability (VP). With the administration of hCG, the expression vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR-2) mRNA increases significantly rising to a maximum coinciding with peaked VP. Immunohistochemistry shows the presence of VEGF and VEGFR-2 proteins in the granulosa-lutein and endothelial cells of the entire corpus luteum. These findings suggest that the syndrome can be prevented…
Social body odors
2013
Clef UT: 000324010400049; National audience
Interrelationship between reproductive hormones and acute phase proteins during estrous cycle and pregnancy in Spanish purebred broodmares
2021
Highlights • Steroid hormones and acute phase proteins in cyclic and pregnant mares were evaluated. • SAA and CRP did not discriminate cyclic and pregnant mares. • Pregnancy induced a limited acute phase response in Spanish purebred mares. • SAA, Hp and CRP were independent of E1 and P4 dynamics during pregnancy.
Concentrations of ovarian proteohormones as biological markers for the outcome of assisted reproductive technology
2002
Objective: To assess whether the ovarian proteohormones inhibin A and B, pro-alpha-C and activin A could act as direct biological markers of a poorer or better response to ovulation induction or clinical conception through assisted reproductive technology (ART). Methods: Seventy-seven women who underwent ART were included in the study and were divided into two groups: (i) 46 women with sonographically documented follicular maturation; and (ii) 36 women who demonstrated inadequate follicle development. Blood samples were analyzed for inhibin A, inhibin B, pro-alpha-C, activin A and estradiol (E2) at day 3 of stimulation with recombinant follicle-stimulating hormone (rFSH) after pituitary dow…
Effects of Environmental Lighting and Tryptophan Devoid Diet on the Rat Vaginal Cycle
1998
Cerebral serotonin level influences luteinizing hormone release and, consequently, ovulation. The present study evaluated the effects of precooked maize meal (polenta), a diet almost devoid of tryptophan the serotonin precursor on the alterations of the estrus cycle as measured by vaginal smears analysis in Wistar rats. Several conditions of environmental lighting were used in order to modify ovarian cycle: 1) natural alternating light/dark cycle; 2) continuous darkness; 3) continuous light by sodium steams: 4) continuous light by fluorescent neon tubes. Rats bred in continuous lighting showed estrus-proestrus rate significantly greater than rats bred in normal lighting or in continuous dar…
Ovarian size and blood flow in women with polycystic ovary syndrome (PCOS) and their correlations with some endocrine parameters
2005
Objective: To determine how common polycystic ovarian morphology may be in women given the clinical diagnosis of polycystic ovary syndrome (PCOS) based on chronic anovulation and hyperandrogenism and whether certain hormonal factors correlate with ovarian morphology and blood flow. Design: Prospective study. Setting: Two academic endocrinology centers in Italy. Patient(s): Three hundred twenty-six women with PCOS and 50 age-matched and weight-matched ovulatory women. Intervention(s): Ultrasound assessment of ovarian morphology in patients and controls and ovarian blood flow and fasting hormone levels in a subset of 50 patients and matched controls. Main Outcome Measure(s): Ovarian morpholog…
65 ASSOCIATION BETWEEN ALDOSTERONE AND CORTISOL LEVELS DURING THE OVULATORY PERIOD IN SPANISH PUREBRED MARES
2014
Preovulatory increased aldosterone (ALD) has been described as one of the physiological events that characterise the oestrous cycle in relation to the dynamics of the renin angiotensin aldosterone system. Within the mechanisms associated with this response are the stimulating effect of oestrogen on the synthesis of angiotensinogen, haemodynamic variations of renal blood flow, changes in sodium concentration, changes in the local sympathetic activity, and the effect of cortisol (CORT). In fact, CORT via adrenocorticotropic hormone contributes primarily to preovulatory ALD, and it is the primary regulator factor synthesis ALD (Chidambaram et al. 2002; Pechère-Bertschi et al. 2002; Szmuilowic…
Uterine Receptivity and the Ramifications of Ovarian Stimulation on Endometrial Function
2007
Controlled ovarian stimulation (COS) is widely used in assisted reproduction techniques (ART). However, hormonal treatment induces endometrial alterations that may alter implantation rates compared with natural cycles. Endometrial alterations have been observed by histological and biochemical techniques. The recent developments in functional genomics have provided objective tools to analyze the endometrium in natural cycles and evaluate the impact of COS protocols in endometrial development. This article describes the fundamental aspects of endometrial receptivity in natural cycles and reports how COS affects the morphology, biochemistry, and the genomic pattern of the endometrium.
Diagnosis, phenotype, and prevalence of polycystic ovary syndrome.
2006
New diagnostic criteria for polycystic ovary syndrome (PCOS) suggested three main phenotypes: classic (hyperandrogenism and anovulation), ovulatory, and normoandrogenic. However, it is unclear whether the normoandrogenic phenotype actually represents PCOS. Overall, 6% to 8% of reproductive-aged women suffer from PCOS, making this disorder one of the most common endocrine abnormalities.