abstract：:Randomized clinical trials (RCTs) have been used to assess interventions affecting health since biblical times. They provide the most valid means of measuring the true effects of intervention compared with no treatment or placebo. Although they can also be used to assess the value of diagnostic tests, this article foc...

journal_title：Seminars in reproductive medicine

authors： Hughes EG

更新日期：2003-02-01 00:00:00

abstract：:Pregnancy results in major changes in the hypothalamo-pituitary-adrenal (HPA) axis, which in turn influence fetal growth and the timing of labor. From the beginning of the second trimester maternal cortisol secretion increases, and in late pregnancy the placenta, in large part mediated through corticotroph-releasing h...

journal_title：Seminars in reproductive medicine

authors： Trainer PJ

更新日期：2002-11-01 00:00:00

abstract：:In this article the role of LH receptor gene mutations in patients with aberrant sex differentiation is discussed. In a dominant autosomal familial form of precocious puberty in boys (familial male-limited precocious puberty) LH receptor gene mutations have been identified. These single amino acid changes, mostly foun...

journal_title：Seminars in reproductive medicine

authors： Themmen AP,Verhoef-Post M

更新日期：2002-08-01 00:00:00

abstract：:Endocrine disrupters are exogenous substances that cause adverse effects in the endocrine system. Sexual differentiation is regulated by reproductive hormones. Male differentiation is critically dependent on normal androgen action, which in turn depends on normal production of luteinizing hormone. Other essential horm...

journal_title：Seminars in reproductive medicine

authors： Toppari J

更新日期：2002-08-01 00:00:00

abstract：:Leptin is a circulating protein produced by adipocytes that has been implicated in control of body weight through appetite regulation and control of reproduction, most likely through an effect on the central nervous system. From studies in mice, it is clear that the genetic background of the animal on which the mutati...

journal_title：Seminars in reproductive medicine

authors： Lado-Abeal J,Norman RL

更新日期：2002-05-01 00:00:00

abstract：:The ability of glycerol to protect cells from freezing injury was discovered accidentally. The subsequent development of cryopreservation techniques has had a huge impact in many fields, most notably in reproductive medicine. Freezing injury has been shown to have two components, direct damage from the ice crystals an...

journal_title：Seminars in reproductive medicine

authors： Pegg DE

更新日期：2002-02-01 00:00:00

abstract：:Contraceptive vaginal rings (CVRs) contain sex steroids that diffuse through a plastic polymer ring at a constant rate and are absorbed directly through the vaginal epithelium into the systemic circulation. This delivery system provides many advantages over oral contraceptives (OCs), including avoidance of the first-p...

journal_title：Seminars in reproductive medicine

authors： Harwood B,Mishell DR Jr

更新日期：2001-12-01 00:00:00

abstract：:Translocations involving the X and Y chromosomes are often associated with anomalies of gonadal development. Transfer of Yp sequences, including the testis-determining SRY gene, to the terminal portion of the short arm of the X chromosome is associated with 46,XX maleness and in rare cases 46,XX true hermaphroditism. ...

journal_title：Seminars in reproductive medicine

authors： McElreavey K,Cortes LS

更新日期：2001-06-01 00:00:00

abstract：:Luteinizing hormone (LH) and human chorionic gonadotropin (hCG) share a common receptor in gonadal cells; however, the presence of these receptors has also been detected in several nongonadal but reproduction-associated tissues of pig, human, and other species. There are no data about the ontogeny of the human LH/hCG ...

journal_title：Seminars in reproductive medicine

authors： Ziecik AJ,Derecka K,Gawronska B,Stepien A,Bodek G

更新日期：2001-01-01 00:00:00

abstract：:Gonadotropins cross the vascular endothelial barrier to reach their target organs. Hormone concentrations in blood are very low and fluctuate rapidly to give sharp biological effects. Nonspecific transendothelial transport mechanisms are slow and markedly concentration dependent. There is thus a need for specific tran...

journal_title：Seminars in reproductive medicine

authors： Ghinea N,Milgrom E

更新日期：2001-01-01 00:00:00

abstract：:Couples experiencing recurrent pregnancy loss are often concerned that toxins within the environment have contributed to their reproductive difficulty. Questions posed by these couples to their health care providers are difficult to answer because scientifically accurate information regarding the reproductive impact o...

journal_title：Seminars in reproductive medicine

authors： Gardella JR,Hill JA 3rd

更新日期：2000-01-01 00:00:00

abstract：:Over the past decade there has been a resurgence of interest in the culture media used in clinical in vitro fertilization. Unfortunately, during this time more confusion than consensus appears to have developed regarding the composition of these media. In order to facilitate a clearer understanding of this field, it i...

journal_title：Seminars in reproductive medicine

authors： Gardner DK,Pool TB,Lane M

更新日期：2000-01-01 00:00:00

abstract：:Premature ovarian failure (POF) is a disorder characterized by lack of ovulation and elevated levels of serum gonadotropins before the age of 40. The etiology of POF is not known but different environmental and genetic factors are involved, suggesting high heterogeneity of the disorder. The involvement of X-linked gen...

journal_title：Seminars in reproductive medicine

authors： Bione S,Toniolo D

更新日期：2000-01-01 00:00:00

abstract：:Despite the critical role the placenta plays in governing the outcome of pregnancy, a great deal remains to be learned about this transient organ. Several factors have contributed to our relative lack of knowledge. For example, most of the placenta's development, which precedes that of the embryo or fetus, occurs duri...

journal_title：Seminars in reproductive medicine

authors： Fisher SJ

更新日期：2000-01-01 00:00:00