Purpose: To determine whether age modifies the effect of the number of motile spermatozoa inseminated (NMSI) as a predictor of success in Intrauterine Insemination (IUI).
Methods: This retrospective cohort study included all patients who underwent IUI at an academic infertility center between October 2004 and June 2018. The primary outcome was clinical pregnancy (CP; a gestational sac and fetal heartbeat on ultrasound).
Background: Biofortified orange-fleshed sweetpotato (OFSP) varieties are being promoted to reduce vitamin A deficiencies due to their higher beta-carotene content. For OFSP varieties to have impact they need to be accepted and consumed at scale amongst populations suffering from vitamin A deficiencies.
Objective: We investigated the sensory and cultural acceptability of OFSP varieties amongst households with children aged between 2-5 years old in two areas in Central and Southern Malawi using an integrated model of the Theory of Planned Behavior (TPB) and the Health Belief Model (HBM).
Soybean production can contribute to the nitrogen economy of smallholder farming systems, but our understanding of factors explaining variability in nitrogen fixation and rotational benefits across farms and regions is limited. Biological nitrogen fixation (BNF) was quantified with the natural abundance method in 150 farmer-managed soybean plots under different varieties and inputs in Dowa, Mchinji and Salima districts of Malawi. Soybean yielded on average 1.
View Article and Find Full Text PDFHorm Mol Biol Clin Investig
November 2015
Background: This study examined the effect of insulin sensitivity on the responsiveness of appetite regulatory brain regions to visual food cues.
Materials And Methods: Nineteen participants diagnosed with polycystic ovary syndrome (PCOS) were divided into insulin-sensitive (n=8) and insulin-resistant (n=11) groups based on the homeostatic model assessment of insulin resistance (HOMA2-IR). Subjects underwent functional magnetic resonance imaging (fMRI) while viewing food pictures following water or dextrose consumption.
We postulate that insulin regulation of food intake is compromised when insulin resistance is present. In order to investigate the effect of insulin sensitivity on appetitive brain responses, we conducted functional magnetic resonance imaging studies in a group of women diagnosed with polycystic ovary syndrome (PCOS) in which insulin sensitivity ranged from normal to resistant. Subjects (n=19) were imaged while viewing pictures of high calorie (HC) foods and low calorie (LC) foods after ingesting either 75 g glucose or an equivalent volume of water.
View Article and Find Full Text PDFObjective: Insulin is one of several molecules that transmit information about energy balance to the brain. It has been hypothesized that insulin resistance fosters non-homeostatic eating. The objective of the current study was to characterize corticolimbic brain responses to appetitive stimuli in subjects with insulin sensitivities ranging from resistant to normal.
View Article and Find Full Text PDFFood intake is decreased during the late follicular phase and increased in the luteal phase of the menstrual cycle. While a changing ovarian steroid milieu is believed to be responsible for this behavior, the specific mechanisms involved are poorly understood. Brain activity in response to visual food stimuli was compared during the estrogen dominant peri-ovulatory phase and the progesterone dominant luteal phase of the menstrual cycle.
View Article and Find Full Text PDFHum Reprod Update
July 2010
BACKGROUND Obesity affects many aspects of health, including reproduction. Despite unrelenting warnings about the health consequences of obesity, its prevalence continues to rise. Beginning with the discovery of leptin in 1994, the endocrinology of energy homeostasis has been significantly advanced.
View Article and Find Full Text PDFBackground: Measurement of mid-gestation cervix length has become a common screening tool for preterm birth. Our study was designed to assess the value of cervix length and serum relaxin in the prediction of spontaneous preterm birth at < 35 and < 37 weeks' gestation in a general obstetric population.
Methods: A prospective cohort of women with a singleton pregnancy had blood collected at 24 and 28 weeks' gestation for determination of serum relaxin immediately before transvaginal ultrasound measurement of cervical length.
Peptide YY (PYY) is produced in L cells of the intestine and is released after eating. PYY circulates in a truncated form designated PYY(3-36). PYY(3-36) is thought to be a physiologic anorexigenic peptide.
View Article and Find Full Text PDFThis paper reports the proceedings of a consensus meeting on the incidence and complications of multiple gestation in Canada. In addition to background presentations about current and possible future practice in Canada, the expert panel also developed a set of consensus points. The need for infertility to be understood, and funded, as a healthcare problem was emphasized, along with recognition of the emotional impact of infertility.
View Article and Find Full Text PDFLeptin is a cytokine produced by white adipose tissue that circulates in direct proportion to adiposity and is an important signal of energy balance. Leptin inhibits food intake in rodents by inhibiting the orexigenic neuropetides neuropeptide Y (NPY) and agouti regulated peptide (AgRP) and stimulating the anorexigenic neuropeptides alpha-melanocyte-stimulating hormone (alpha-MSH) and cocaine-amphetamine-regulated transcript (CART). In order to extend our understanding of neuroendocrine regulation of appetite in the primate, we determined the effect of a metabolic challenge on CART, NPY, and leptin receptor (Ob-R) messenger ribonucleic acid (mRNA) in the nonhuman primate (NHP) hypothalamus.
View Article and Find Full Text PDFNeuroendocrinology
February 2007
A chronic negative energy balance due to low nutritional intake or increased energy expenditure alters several neuroendocrine axes. The reproductive and thyroid axes are inhibited while the adrenal axis is stimulated. In primates, anovulation resulting from a chronic negative energy balance is a condition often referred to as nutritional amenorrhea.
View Article and Find Full Text PDFProg Neuropsychopharmacol Biol Psychiatry
June 2006
Citalopram, a selective serotonin reuptake inhibitor (SSRI), has been used as a neuroendocrine probe to assess serotonin (5-HT) function in human subjects. In an effort to characterize the oral citalopram challenge, we hypothesized that oral racemic citalopram would increase plasma cortisol, prolactin and adrenocorticotropic hormone (ACTH) concentrations; ACTH had not been measured in previous studies on the neuroendocrine effects of citalopram. Nine healthy male subjects initially received 20 mg of citalopram in an open-label study, and subsequently received placebo and 40 mg of citalopram in a single-blind, randomized, cross-over study.
View Article and Find Full Text PDFNutritional amenorrhea is defined as cessation of menstrual cycles resulting from a chronic negative energy balance. Although it is agreed that nutritional amenorrhea results from reduced secretion of GnRH, the neuroendocrine mechanisms leading to GnRH inhibition are poorly defined. Because the invasiveness of many neuroendocrine experimental approaches precludes its use in the clinical setting, we set out to establish a model of nutritional amenorrhea in rhesus monkeys.
View Article and Find Full Text PDFWe recently reported that caloric restriction inhibited ovulation in rhesus monkeys. The objective of the current study was to determine if caloric restriction affected the positive feedback response to ovarian steroids in non-human primates. Studies were conducted in four long-term ovariectomized rhesus monkeys.
View Article and Find Full Text PDFCan J Physiol Pharmacol
December 2004
Adipocytes are the primary source of circulating leptin. Leptin inhibits eating, increases metabolism, and stimulates the reproductive axis. Numerous hypothalamic neuropeptides have been implicated in leptin's behavioral and neuroendocrine effects, including neuropeptide Y (NPY) and cocaine- and amphetamine-regulated transcript (CART).
View Article and Find Full Text PDFHypoglycemia inhibits gonadotropin secretion in primates by an undefined mechanism. Some evidence suggests that hypoglycemia inhibits gonadotropin secretion independent of gonadotropin-releasing hormone (GnRH) inhibition. To this end, the effect of insulininduced hypoglycemia on the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) response to graded doses of GnRH (25, 75, and 250 ng/kg) administered at 120-min intervals was determined in rhesus monkeys.
View Article and Find Full Text PDFAcute administration of corticotrophin-releasing hormone (CRH) has been shown to inhibit gonadotropin secretion in several species including rodents, sheep, humans, and nonhuman primates. Similarly, a variety of acute stressors have been shown to inhibit tonic gonadotropin secretion and may do so through a CRH mechanism. Stress-induced inhibition of tonic gonadotropin secretion below levels required for follicular maturation would be expected to inhibit ovulation.
View Article and Find Full Text PDFObjective: To evaluate the ovarian follicular dynamics of cycle modification with the aromatase inhibitor letrozole compared with clomiphene citrate in normal ovulatory women.
Design: Randomized double-blind controlled trial.
Setting: Tertiary care hospital.
Objective: To evaluate the potential of photodynamic therapy with aminolevulinic acid (ALA-PDT) for ablation of endometrial explants in a rat endometriosis model and to compare the effect of ALA-PDT, electrosurgery, and surgical resection on normal peritoneum.
Design: Prospective controlled experimental trial.
Setting: University medical center.
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a widespread environmental contaminant that has profound deleterious effects on development and reproduction. TCDD may act at one or more levels to alter the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes. The objective of this study was to investigate whether TCDD modulates neuroendocrine systems by altering gene expression of arginine vasopressin (AVP), corticotrophin-releasing hormone (CRH), or pro-opiomelanocortin (POMC), which are important neuroregulators of the HPA and HPG axes.
View Article and Find Full Text PDFObjective: To test the effectiveness of 5-aminolevulinic acid (ALA)-induced photodynamic endometrial ablation in the rhesus monkey under varying conditions of light delivery (fractionated versus continuous) and steroid priming.
Methods: Photodynamic endometrial ablation was carried out in 17 rhesus monkeys that were either postmenopausal or in the early proliferative phase. Four hours after intralumenal injection of ALA (250 mg in 1 mL hyskon), a quartz fiber with a diffusing tip was inserted.
Background And Objective: This research evaluated the effectiveness of a new nonlaser prototype short-arc lamp to achieve photodynamic ablation of endometrium in a rat.
Study Design/materials And Methods: Thirty female Sprague-Dawley rats were divided into two groups. 5-Aminolevulinic acid (ALA), the precursor to the photosensitizer protoporphyrin IX, was injected into the left uterine horn and vehicle alone (Hyskon) was injected into the right horn of 23 rats (group 1).
Ovarian steroids increase hypothalamic-pituitary-adrenal (HPA) axis activity and sensitize the hypothalamic-pituitary-ovarian (HPO) axis to stress-induced inhibition. The present study investigated the effect of ovarian steroids on CRH and arginine vasopressin (AVP) messenger RNA (mRNA) levels in the rhesus monkey hypothalamus, as both neuropeptides have been shown to stimulate the HPA axis and inhibit the HPO axis in this species. This was accomplished by measuring CRH and AVP mRNA in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) by in situ hybridization histochemistry.
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