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Reproductive Techniques (reproductive + techniques)
Selected AbstractsVaricocelectomy: semen parameters and protamine deficiencyINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 2 2009M. H. Nasr-Esfahani Summary Different methods have been used to evaluate the beneficial effect of varicocelectomy; these include semen parameters and pregnancy rate. Because of high biological variability of semen parameters, sperm functional tests have been considered as an efficient end point in assessment of fertility. Therefore, the aim of this study was to evaluate the effect of varicocelectomy on semen parameters and sperm protamine deficiency in 192 patients. The results of the present study show that all the three semen parameters and percentage of sperms with normal protamine content have improved post-surgery. The cumulative pregnancy rate was 34.6%. Comparing the results of the semen parameters and protamine content between patients whose partner became pregnant to those who did not benefit from varicocelectomy before and 6 months after surgery, show that patients may benefit from varicocelectomy that had higher initial semen density and better sperm morphology prior to surgery. Detailed analyses of sperm morphology, along with aforementioned results reveal that the factors which account for pregnancy difference are: (i) improvement in early events of spermatogenesis, possibly during spermatocytogensis and reduction division; and (ii) late spermiogenesis events. Thus, it can be suggested that patients with low initial sperm count may benefit more from assisted reproductive techniques or varicocelectomy followed by assisted reproduction. [source] Regulation of Expression of Mammalian Gonadotrophin-Releasing Hormone Receptor GenesJOURNAL OF NEUROENDOCRINOLOGY, Issue 10 2005J. P. Hapgood Abstract Gonadotrophin-releasing hormone (GnRH), acting via its cognate GnRH receptor (GnRHR), is the primary regulator of mammalian reproductive function, and hence GnRH analogues are extensively used in the treatment of hormone-dependent diseases, as well as for assisted reproductive techniques. In addition to its established endocrine role in gonadotrophin regulation in the pituitary, evidence is rapidly accumulating to support the expression and functional roles for two forms of GnRHR (GnRHR I and GnRHR II) in multiple and diverse extra-pituitary mammalian tissues and cells. These findings, together with findings indicating that mutations of the GnRHR are linked to the disease hypogonadotrophic hypogonadism and that GnRHRs play a direct role in neuronal migration and reproductive cancers, have presented new therapeutic targets and intensified research into the structure, function and mechanisms of regulation of expression of GnRHR genes. The present review focuses on the current knowledge on tissue-specific and hormonal regulation of transcription of mammalian GnRH receptor genes. Emerging insights, such as the discovery of diverse regulatory mechanisms in pituitary and extra-pituitary cell types, nonclassical mechanisms of steroid regulation, the use of composite elements for cell-specific expression, the increasing profile of hormones involved in regulation, the complexity of kinase pathways that target the GnRHR I gene, as well as species-differences, are highlighted. Although further research is necessary to understand the mechanisms of regulation of expression of GnRHR I and GnRHR II genes, the GnRHR is emerging as a potential target gene for facilitating cross-talk between neuroendocrine, immune and stress-response systems in multiple tissues via autocrine, paracrine and endocrine signalling. [source] Observations on the female internal reproductive organs of the brown howler monkey (Alouatta guariba clamitans)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2009Mariana Matera Veras Abstract Alouatta guariba clamitans (brown howler monkey) is an endemic primate from the southeastern Brazil tropical forests, classified as near threatened by the IUCN Red List 2007. The genus Alouatta is one of the most difficult New World monkeys to breed and rear in captivity. In this study we examined the macroscopic and histological aspects of the female genital tract of wild brown howler monkeys to provide baseline information for future reproduction research. The anatomical relationship between the vagina, uterus, broad ligament, oviducts and ovaries are those of a typical primate reproductive tract. The fundic portion of the uterus is globoid, the cervix is well developed, which confers to the uterus an elongated shape, and the vagina is a long flattened channel. Histological analysis conducted in females in the follicular phase revealed large quantities of interstitial luteinized tissue in the ovaries, a stratified nonkeratinized vaginal epithelium, lack of glands in the vaginal mucosa and simple tubular endometrial glands. The observed anatomical features should be considered in the adaptation and application of assisted reproductive techniques aimed at improving captive reproduction for species conservation. Am. J. Primatol. 71:145,152, 2009. © 2008 Wiley-Liss, Inc. [source] REVIEW ARTICLE: Inflammation and ImplantationAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 1 2010Nava Dekel Approximately half of all human embryo implantations result in failed pregnancy. Multiple factors may contribute to this failure, including genetic or metabolic abnormalities of the embryo. However, many of these spontaneous early abortion cases are attributed to poor uterine receptivity. Furthermore, although many fertility disorders have been overcome by a variety of assisted reproductive techniques, implantation remains the rate-limiting step for the success of the in vitro fertilization (IVF) treatments. It has been demonstrated that endometrial biopsies performed either during the spontaneous, preceding cycle, or during the IVF cycle itself, significantly improve the rate of implantation, clinical pregnancies and live births. These observations suggest that mechanical injury of the endometrium may enhance uterine receptivity by provoking the immune system to generate an inflammatory reaction. In strong support of this idea, we recently found that dendritic cells (DCs), an important cellular component of the innate immune system, play a critical role in successful implantation in a mouse model. In this review, we discuss the hypothesis that the injury-derived inflammation in the biopsy-treated patients generates a focus for uterine DCs accumulation that, in turn, enhances the endometrial expression of essential molecules, which facilitate the interaction between the embryo and the uterine epithelium. [source] The role of food supplementation in the treatment of the infertile couple and for assisted reproductionANDROLOGIA, Issue 5 2010F. Comhaire Summary Couple infertility commonly results from the synergistic negative influence of several factors. External factors, related to life-style and environmental exposure, reinforce the effects of congenital or acquired damage through direct toxicity, hormone disruption and overload of reactive oxygen species. Combating obesity, correcting inappropriate diet, and banning the abuse of tobacco and alcohol are part of the integrated approach of the infertile couple. Nutraceuticals are judiciously formulated food supplements containing particular vitamins, antioxidants, minerals and plant extracts. There is strong evidence that complementary treatment with an appropriate nutraceutical improves the natural conception rate of infertile couples and increases the success rate of assisted reproductive techniques. [source] Effects of post-density gradient swim-up on apoptosis signalling in human spermatozoaANDROLOGIA, Issue 2 2010S. Grunewald Summary The inclusion of apoptotic spermatozoa during assisted reproductive techniques (ART) may be one reason for suboptimal success rates. The aim of our study was to evaluate the potential of routine semen preparation to eliminate spermatozoa with activated apoptosis signalling. Semen samples from 20 infertility patients scheduled for ART procedures were investigated. Following density gradient centrifugation (DGC) and swim-up, aliquots were taken from each sample to analyse motility, Caspase-3 activation (CP3) and integrity of the mitochondrial membrane potential (MMP) using flow cytometry. Aliquots from the neat semen served as controls. Semen samples of patients contained 53.8 ± 17.7% spermatozoa with disrupted MMP and 51.8 ± 14.9% with active CP3. Preparation by DGC and swim-up resulted in improvement of progressive motility (+43.5%) and reduction of spermatozoa with disrupted MMP (,34.3%) and activated CP3 (,25.7%, P < 0.01). Minimal reduction of spermatozoa with disrupted MMP and active CP3 was 6.0% and 0.7%, maximum reduction was 65.5% (disrupted MMP) and 49.3% (CP3). Semen samples of subfertile patients contain high levels of spermatozoa with activated apoptosis signalling. Although there was a reduction in the majority of the samples, profound interindividual differences in the separation effect demand further development of innovative molecular-based separation methods to deplete apoptotic spermatozoa. [source] Human sperm DNA integrity in normal and abnormal semen samples and its correlation with sperm characteristicsANDROLOGIA, Issue 4 2009A. C. Varghese Summary Reports indicate an increase in the incidence of DNA fragmentation in male factor infertility and its role in the outcome of assisted reproductive techniques (ART). However, reports are conflicting between the relationships of sperm DNA integrity with conventional semen parameters. We examined the relationship between conventional sperm parameters and DNA integrity using acridine orange (AO) test. The study included 373 patients and 28 fertile volunteers. DNA normality was compared with semen parameters between the patient and donor populations. Significant correlations were noted between DNA normality and sperm concentration (r = 0.18, P = 0.000), motility (r = 0.21, P = 0.0001), rapid motility (0.19, P = 0.000), normal morphology by World Health Organization (r = 0.15, P = 0.019) and head defects (r = ,0.15, P = 0.023). A significant difference was noted in AO levels between donors and patients with asthenozoospermia (P = 0.002) and oligoasthenozoospermia (P = 0.001). A significant difference in DNA integrity was noted in samples having <30% and >30% normal morphology. A wide range of % DNA normality was observed in the patient group. Sperm assessment for DNA status using AO is reliable and shows good correlation with sperm count, motility and morphology. Assessment of sperm DNA status with AO staining may be helpful prior to ART. [source] Bacterial risk and sperm cryopreservationANDROLOGIA, Issue 5 2004R. Levy Summary. Prior to sperm cryopreservation, French guidelines only recommend viral screening for serological status towards human immunodeficiency virus, hepatitis B and C viruses and Treponema palidum. The probability of semen infection by other bacterial pathogens is not taken into consideration by the current recommendations. The objective of the present study was to evaluate this risk and a strategy to reduce it prospectively. Ninety-six patients consulting for sperm cryopreservation underwent a semen culture simultaneously to cryopreservation. The patients were classified into three groups following semen culture results: negative culture (group 1, 77/96, 80.2%), positive culture with saprophytic agents (group 2, 9/96, 9.4%) and positive culture with pathogen agents (group 3, 10/96, 10.4%). For six patients of the latter group showing a genital infection with Ureaplasma urealyticum, a discontinuous gradient selection performed on the cryopreserved sample was efficient to discard bacteria. These data emphasize the usefulness to cultivate semen simultaneously to cryopreservation and demonstrate the ability to remove some microbial agents from semen before its use in assisted reproductive techniques. [source] | ||||||||||