Seminars in reproductive medicine
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Abnormal bleeding is a common clinical problem in adolescents, with the vast majority of cases resulting from anovulatory menstrual cycles. Although most episodes of abnormal vaginal bleeding do not cause acute medical complications, bleeding can be traumatic for young patients and their families. Health care providers with a solid knowledge of menstrual physiology and a thorough approach to differential diagnosis can evaluate and appropriately manage adolescents. In this article, we review the maturation of the hypothalamic ovarian axis, the most frequent etiologies of abnormal bleeding, as well as other less common causes and discuss diagnosis and treatment modalities.
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Semin. Reprod. Med. · May 2003
ReviewGenomics' role in understanding the pathogenesis of endometriosis.
Endometriosis is a benign, estrogen-dependent disorder that has multifactorial components presumed in its pathogenesis. The molecular mechanisms underlying endometrial tissue attachment to the peritoneal surface or metaplasia of the mesothelium, and subsequent invasion and establishment of a blood supply and survival of the endometriotic implants, are not well understood. Recent advances in molecular biology and genomics suggest an intrinsic abnormality in the eutopic endometrium of women with endometriosis that predisposes to these processes. These are discussed herein.
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Semin. Reprod. Med. · Feb 2003
ReviewRandomized clinical trials: the meeting place of medical practice and clinical research.
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 focuses on randomized trials in the context of treatment. ⋯ It is also essential to establish that the question posed is ethical, the methods of study are valid, and that follow-up is complete, with an "intent to treat" analysis. Results are best presented using both proportions and absolute numbers. By providing clinical decision-makers with numbers needed to treat or harm, decisions may be better informed and easier to understand, than if proportions alone are used.
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Semin. Reprod. Med. · Aug 2002
ReviewCongenital adrenal hyperplasia: 11beta-hydroxylase deficiency.
The most potent corticosteroids are 11beta-hydroxylated compounds. In humans, two cytochrome P450 isoenzymes with 11beta-hydroxylase activity, catalyzing the biosynthesis of cortisol and aldosterone, are present in the adrenal cortex. CYP11B1, the gene encoding 11beta-hydroxylase (P450c11), is expressed in high levels in the zona fasciculata and is regulated by adrenocorticotropic hormone (ACTH). ⋯ Molecular genetic studies of the CYP11B1 gene in 11beta-hydroxylase deficiency have led to the identification of several mutations. Transfection experiments showed loss of enzyme activity in vitro. Molecular genetic studies have practical importance for the prenatal diagnosis of virilizing CAH forms.
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Semin. Reprod. Med. · May 2002
ReviewLeptin and the onset of puberty: insights from rodent and human genetics.
Deficiency of the adipocyte-derived hormone leptin in ob/ob mice results in severe, early-onset obesity and infertility. Administration of leptin results in complete reversal of the phenotype, suggesting that leptin is needed for the development of puberty in rodents. ⋯ This work suggests that leptin is a metabolic gate for the onset of puberty in humans. Leptin's actions may be mediated by central pathways and by direct action on peripheral organs.