Latest Articles Include:
- Techniques for cryopreservation of individual or small numbers of human spermatozoa: a systematic review
AbdelHafez F Bedaiwy M El-Nashar SA Sabanegh E Desai N - Hum Reprod Update 15(2):153-164 (2009)
BACKGROUNDDespite interest in cryopreservation of individual or small number of human spermatozoa, to date, little data is available as regards its effectiveness. We systematically reviewed the outcome after cryopreservation of individual or small numbers of human spermatozoa in patients with severe male factor of infertility. METHODSWe searched the MEDLINE, EMBASE, Cochrane Systematic Reviews, CENTRAL, Web of Science, Scopus databases for relevant studies up to June of 2008. The search used terms referring to cryopreservation of small amount of sperm. Included studies were limited to human studies with no language restrictions. RESULTSWe identified 30 reports including 9 carriers used for cryopreservation of small quantities/numbers of human spermatozoa (7 non-biological and 2 biological carriers). A wide variety of cryopreservation vehicles were reported. The recovery rate of spermatozoa cryopreserved in a known small number varied widely from 59 to 100%. Fertiliza! tion rates were in the range of 18-67%. Frozen-thawed spermatozoa, using this method, were subsequently used for intracytoplasmic sperm injection in only five studies, with few pregnancies reported so far. To date, there remains no consensus as to the ideal carrier for cryopreservation of small number of spermatozoa for clinical purposes. CONCLUSIONSCryopreservation of individual or small numbers of human spermatozoa may replace the need for repeated surgical sperm retrieval. A controlled multicenter trial with sufficient follow-up would provide valid evidence of the potential benefit of this approach. - Contraception and HIV infection in women
Heikinheimo O Lähteenmäki P - Hum Reprod Update 15(2):165-176 (2009)
BACKGROUNDMore than 15 million women, many of reproductive age, were infected with human immunodeficiency virus (HIV) at the end of 2007. As the HIV epidemic evolves, heterosexual intercourse is increasingly risky: the risk of infection in exposed young women is 4- to 7-fold higher than in young men and nearly half a million newborns annually have HIV. This review aims to show the effect of contraceptive choices on risk of HIV and on the course of disease in women with HIV. METHODSRelevant citations were selected by agreement between the authors after a search of MEDLINE using the terms HIV/AIDS and contraception. RESULTSRisk of transmission of HIV varies from 1 in 200 to 1 in 10 000 coital incidents, depending in part on the integrity of the vaginal epithelium. Consistent use of male condoms has been proven to reduce horizontal transmission of HIV by 80% among HIV-serodiscordant couples. Hormonal contraception may increase the risk of HIV acquisition in high-risk wo! men such as commercial sex workers, but not in women at low risk of HIV. While hormonal contraception did not affect progression of disease in two cohort studies involving 370 women, in a randomized trial among women not receiving antiretroviral medication, clinical disease accelerated in the oral contraception group (13.2/100 woman-years) compared with the copper intrauterine devices group (8.6/100 woman-years; hazard ratio, 1.5; 95% confidence interval, 1.04-2.1). Hormonal contraception does not interfere with antiviral drug effectiveness. CONCLUSIONSAll the available reversible contraceptive methods can generally be used by women at risk of HIV infection and by HIV-infected women. Further studies are needed to investigate the safety and efficiency of hormonal contraception in women living with HIV/AIDS. - The effect of surgery for symptomatic endometriosis: the other side of the story
Vercellini P Crosignani PG Abbiati A Somigliana E Viganò P Fedele L - Hum Reprod Update 15(2):177-188 (2009)
BACKGROUNDSurgery is often considered the best treatment option in women with symptomatic endometriosis. However, extent and duration of the therapeutic benefit are still poorly defined. METHODSThe best available evidence on surgery for endometriosis-associated pain has been reviewed to estimate the effect size of interventions in the most frequently encountered clinical conditions. RESULTSMethodological drawbacks limit considerably the validity of observational, non-comparative studies on the effect of laparoscopy for stage I-IV disease. As indicated by the results of three RCTs, the absolute benefit increase of destruction of lesions compared with diagnostic only operation in terms of proportion of women reporting pain relief was between 30% and 40% after short follow-up periods. The effect size tended to decrease with time and the re-operation rate, based on long-term follow-up studies, was as high as 50%. In most case series on excisional surgery for rectovaginal! endometriosis, substantial short-term pain relief was experienced by [~]70-80% of the subjects who continued the study. However, at 1 year follow-up, [~]50% of the women needed analgesics or hormonal treatments. Major complications were observed in 3-10% of the patients. Medium-term recurrence of lesions was observed in [~]20% of the cases, and around 25% of the women underwent repetitive surgery. CONCLUSIONSPain recurrence and re-operation rates after conservative surgery for symptomatic endometriosis are high and probably underestimated. Clinicians and patients should be aware that the expected benefit is operator-dependent. - Reproductive outcome after bariatric surgery: a critical review
Guelinckx I Devlieger R Vansant G - Hum Reprod Update 15(2):189-201 (2009)
BACKGROUNDAfter many cycles of weight loss and weight gain, more and more morbidly obese patients undergo bariatric surgery, like gastric banding or gastric bypass, as the ultimate treatment for their obesity-problem. Since women of reproductive age are candidates for bariatric surgery, concerns arise regarding the potential impact on future pregnancy. METHODSEnglish-language articles were identified in a PUBMED search from 1982 to January 2008 using the keywords for pregnancy and bariatric surgery or gastric bypass or gastric banding. RESULTSThe few reported case-control and cohort studies clearly show improved fertility and a reduced risk in obstetrical complications, including gestational diabetes, macrosomia and hypertensive disorders of pregnancy, in women after operatively induced weight loss when compared with morbidly obesity women. The incidence of intrauterine growth restriction (IUGR) appears to be increased, however. No conclusions can be drawn concerning! the risk for preterm labour and miscarriage, although these risks are probably increased compared with controls matched for body mass index. Operative complications are not uncommon with bariatric surgery and several cases have pointed to the increased risk for intestinal hernias and nutritional deficiencies in subsequent pregnancy. Deficiencies in iron, vitamin A, vitamin B12, vitamin K, folate and calcium can result in both maternal complications, such as severe anaemia, and fetal complications, such as congenital abnormalities, IUGR and failure to thrive. CONCLUSIONSClose supervision before, during and after pregnancy following bariatric surgery and nutrient supplementation adapted to the patient's individual requirements can help to prevent nutrition-related complications and improve maternal and fetal health, in this high-risk obstetric population. - The role of kisspeptin in the control of gonadotrophin secretion
Roseweir AK Millar RP - Hum Reprod Update 15(2):203-212 (2009)
BACKGROUNDKisspeptins, and their cognate receptor gpr-54, were first found to regulate the hypothalamic-pituitary-gonadal (HPG) axis in 2003, when two groups demonstrated that mutations in gpr-54 cause idiopathic hypogonadotropic hypogonadism characterized by delayed or absent puberty. This review aims to highlight discoveries in the KiSS-1/gpr-54 system, focusing on their regulation of the HPG axis in male and female reproductive systems of both mammalian and non-mammalian vertebrates. METHODSA search of PUBMED and the authors' files was done without limitations by language or species for citations relevant to kisspeptin, reproduction and signal transduction. RESULTSKisspeptins and gpr-54 are critical for puberty and the regulation of reproduction. Kisspeptins have been implicated in mediating many of the important signals relayed to the gonadotrophin-releasing hormone (GnRH) neuron such as positive and negative feedback, metabolic input and photoperiod. The ability! of kisspeptin neurons to co-ordinate different signals impinging on the HPG axis makes it one of the most important regulators of GnRH and the reproductive axis. CONCLUSIONSKisspeptins are pivotal regulators of the HPG axis and reproduction, with the ability to integrate signals from both internal and external sources. Knowledge about the signalling mechanisms involved in kisspeptin stimulation of GnRH would help improve the understanding of the importance of this critical pathway in reproduction. - New insights into epididymal biology and function
Cornwall GA - Hum Reprod Update 15(2):213-227 (2009)
BACKGROUNDThe epididymis performs an important role in the maturation of spermatozoa including their acquisition of progressive motility and fertilizing ability. However, the molecular mechanisms that govern these maturational events are still poorly defined. This review focuses on recent progress in our understanding of epididymal function including its development, role of the luminal microenvironment in sperm maturation, regulation and novel mechanisms the epididymis utilizes to carry out some of its functions. METHODSA systematic search of Pubmed was carried out using the search term epididymis'. Articles that were published in the English language until the end of August 2008 and that focused on the specific topics described above were included. Additional papers cited in the primary reference were also included. RESULTSWhile the majority of these findings were the result of studies in animal models, recent studies in the human epididymis are also presented inc! luding gene profiling studies to examine regionalized expression in normal epididymides as well as in those from vasectomized patients. CONCLUSIONSSignificant progress has been made in our understanding of epididymal function providing new insights that ultimately could improve human health. The data also indicate that the human epididymis plays an important role in sperm maturation but has unique properties compared with animal models. - Pinopodes: a questionable role in endometrial receptivity
Quinn CE Casper RF - Hum Reprod Update 15(2):229-236 (2009)
BACKGROUNDA better understanding of endometrial receptivity is crucial to the creation and optimization of tests to assess the window of implantation in a clinical setting. Testing endometrial receptivity via scanning electron microscopy of endometrial samples reveals that pinopodes are a very good marker of endometrial receptivity in the rat. There is still disagreement in the literature as to their usefulness as a receptivity marker in both mice and humans. METHODSPublications related to the discovery, study and usefulness of pinopodes as a marker of endometrial preparation for implantation in both rodents and humans were identified through MEDLINE and other bibliographic databases. RESULTSThere is substantial evidence that pinopodes are good markers of endometrial receptivity in the rat. Pinopodes are not useful in the mouse or human as consistent markers of endometrial receptivity for implantation. In the human, pinopodes have a prolonged (>5 days) presence in th! e luteal phase and fail to delineate the brief (24-48 h) window of receptivity. CONCLUSIONSWhile there are many publications arising from one group supporting the use of pinopodes as a reliable marker of human endometrial receptivity, few independent groups have been able to confirm these results. The clinical usefulness of pinopodes to delineate a period of endometrial receptivity seems unlikely following recent findings that pinopodes are present throughout the luteal phase of the menstrual cycle. - Proprotein convertase subtilisin/kexin type 4 in mammalian fertility: a review
Gyamera-Acheampong C Mbikay M - Hum Reprod Update 15(2):237-247 (2009)
BACKGROUNDProprotein convertase subtilisin/kexin type 4 (PCSK4), also known as proprotein convertase 4, belongs to a family of endoproteinases involved in the proteolytic conversion of secretory precursor proteins to their active forms. Its amino acid sequence is highly conserved in mammals, an indication of its biological importance. METHODSWe have searched PubMed and molecular biology databases for information relating to the structure, expression and biological functions of PCSK4. RESULTSPCSK4 is predominantly expressed in male germ cells and located on the plasma membrane overlying the acrosome of sperm. It is also present in ovary and placenta. Inactivation of its gene in mouse does not alter spermatogenesis, but renders sperm incapable of fertilizing oocytes. This incapacity results in part from sperm susceptibility to a premature acrosome reaction and their reduced ability to bind to the zona pellucida. In female mice, a lack of PCSK4 causes subfertility assoc! iated with impaired folliculogenesis. In addition, this enzyme has been shown to stimulate the invasiveness of human placental trophoblasts in culture, suggesting that it may facilitate placentation in vivo. CONCLUSIONSPCSK4 appears to be a crucial enzyme for reproduction. Alterations of PCSK4 expression or activity could be the underlying cause of some unexplained cases of human infertility. Conversely, inactivation of this protease represents a potential strategy for non-hormonal contraception. - Monoamine transporters in human endometrium and decidua
Hansson SR Bottalico B Noskova V Casslén B - Hum Reprod Update 15(2):249-260 (2009)
BACKGROUNDMonoamines play important roles in decidualization, implantation, immune modulation and inflammation. Furthermore, monoamines are potent vasoactive mediators that regulate blood flow and capillary permeability. Regulation of the uterine blood flow is important both during menstruation and pregnancy. Adequate monoamine concentrations are essential for a proper implantation and physiological development of pregnancy. Unlike most transmitter substances, monoamines are recycled by monoamine transporters rather than enzymatically inactivated. Their intracellular fate is influenced by their lower affinity for inactivating enzymes than for vesicular transporters located in intracellular vesicles. Thus, cells are capable not only of recapturizing and degrading monoamines, but also of storing and releasing them in a controlled fashion. METHODSThe general objective of the present review is to summarize the role of the monoamine transporters in the female human reprodu! ction. Since the transporter proteins critically regulate extracellular monoamine concentrations, knowledge of their distribution and cyclic variation is of great importance for a deeper understanding of the contribution of monoaminergic mechanisms in the reproductive process. MEDLINE was searched for relevant publications from 1950 to 2007. RESULTSTwo families of monoamine transporters, neuronal and extraneuronal monoamine transporters, are present in the human endometrium and deciduas. CONCLUSIONSNew knowledge about monoamine metabolism in the endometrium during menstruation and pregnancy will increase understanding of infertility problems and may offer new pharmacological approaches to optimize assisted reproduction. - Current evidence about treatments for ectopic pregnancy: need for a rethink on RCTs
Bignardi T Condous G - Hum Reprod Update 15(2):261-262 (2009)
- Low dose aspirin and IVF: 'Is it time for a meta-analysis'? Continued: the consequences of the choices made
Lambers MJ Mijatovic V Hompes PG - Hum Reprod Update 15(2):262-263 (2009)
- Letrozole in ovulation induction: time to make decisions
Polyzos NP Mauri D Tzioras S - Hum Reprod Update 15(2):263-264 (2009)
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