ISSN:1068-3097    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:1068-3097    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:1068-3097    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Molecular advances have helped elucidate the genetics of various disorders of sex differentiation. Consensus now exists that SRY (sex-determining region Y) is identical to TDF (testis-determining factor). The SRY gene is comprised of two open reading frames of 99 and 273 amino acids, respectively; the key sequence involves an HMG (high mobility group) box that shares characteristics with other DNA binding sequences. The Y chromosome also contains a locus or loci integral for spermatogenesis long postulated to reside on Yq, located in the nonfluorescent region. More recently this locus has been called DAZ (Deleted Azoospermia). The X chromosome has gained added relevance for testicular development because Xp has been shown to contain a region that if duplicated suppresses testicular development despite presence of SRY. Autosomal genes are also important for testicular differentiation. Foremost is the gene causing campomelic dysplasia and XY sex reversal located on 17q24.3-q25; other autosomal regions that could influence testicular development include 3p, 9p, 10q, and 11 p. Genes responsible for many forms of male pseudohermaphroditism have also been localized and dissected molecularly-androgen insensitivity, enzymes in the adrenal biosynthetic pathway, Leydig cell aplasia, and persistence of müllerian derivatives in men. With rare exceptions, these disorders are characterized by molecular heterogeneity. No single mutation is universally observed in affected siblings.

ISSN:1068-3097    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Cytokines are local immunoneuroendocrine mediators of reproductive function acting through specific receptors. Ovulation and embryonic implantation are two essential mechanisms for a normal reproductive process. The study of individual cytokines implicated in these processes teaches us a new paracrine-autocrine point of view. This review examines recently acquired knowledge about the most relevant cytokines regulating the molecular events leading to ovulation and favoring the adhesion phase of the implantation process.

ISSN:1068-3097    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Erectile dysfunction is a common problem, but recent developments in medical therapies have made it possible to provide satisfactory erectile function for most patients. Here we review the available nonsurgical therapies including intracavernosal vasodilator injections, vacuum devices, exogenous androgen therapy, and various oral and topical agents. We particularly focus on the use of intracavernosal prostaglandin E, therapy because recent trials have suggested that it is the most effective medical therapy with minimal side effects available. With the advent of these nonsurgical therapies, most men with erectile dysfunction can enjoy satisfactory erections without requiring surgical intervention such as vascular surgery or penile prostheses.

ISSN:1068-3097    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Classically, the pituitary gonadotropins (ie, luteinizing hormone and follicle-stimulating hormone) have been assigned the role of primary regulators of the ovarian life cycle. As the complexities of the process of follicular growth and maturation are elucidated, the inadequacies of this hypothesis have become evident. To better explain observed phenomena such as recruitment and selection of the dominant follicle, a system of intraovarian regulators has been proposed that would work in concert with gonadotropins amplifying or attenuating gonadotropin action. Over the preceding year, data have been presented supporting the concept that growth factors are likely to be key in vivo players in this regulatory system. Of special note were studies illustrating the importance of the insulinlike growth factor system. This included observations in mice that spontaneous ovulation does not occur without insulinlike growth factor-I, nor is it inducible with physiologic stimuli. Other recently presented data include the finding of a differential expression of vascular endothelial growth factor in healthy versus atretic follicles, and the regulation of transforming growth factor β receptors in hamsters by gonadotropins and sex steroids.

ISSN:1068-3097    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Menopause results in significant changes in the hormonal milieu of the female cardiovascular system. Estrogen levels drop dramatically and are no longer cyclic, leading to many vasomotor, physiologic, and psychologic changes. This review discusses the role steroids play in protecting the cardiovascular system and how hormone replacement therapy with estrogen or estrogen and progesterone can modulate the vasculature. Evidence suggests that basal estrogen levels may play an important role in regulating both vascular responses to vasoactive substances as well as systemic and coronary vascular resistance. These changes appear to be modulated by alterations in synthesis of endothelial cell vasodilators (prostacyclin and nitric oxide) or vasoconstrictors (thromboxane A2and endothelin-1). Although estrogens have limited effects on blood pressure, at therapeutic levels they can produce significant peripheral vasodilation leading to increased heart rate and cardiac output as well as increased coronary artery blood flow. In contrast to estrogen, progesterone and possibly androgens may partially antagonize the beneficial endothelial effects of estrogen.

ISSN:1068-3097    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

An inherited predisposition is known to be an important risk factor for many malignancies, including breast, ovarian, endometrial, and colon cancer. In 1994, BRCAI, the first breast-ovarian cancer gene, was identified. Inherited germline mutations in this tumor suppressor gene are known to account for disease in nearly half of breast cancer families and in the majority of hereditary breast-ovarian and site-specific ovarian cancer families. Since that time, additional genes important in the development of reproductive tract malignancies have been identified. Clearly, the ability to identify women at high risk for ovarian cancer by virtue of their family history provides a unique opportunity to prevent ovarian cancer deaths through screening and prophylactic surgery. More importantly, as our understanding of the biology of these cancer-causing genes grows, it is hoped that we will be able to develop strategies to prevent this biologically aggressive malignancy.

ISSN:1068-3097    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:1068-3097    

出版商:OVID    

年代:1996

数据来源: OVID