ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The endocrine system recently has become appreciated as a potential target site for HIV infection. Abnormal endocrine gland function can occur as a result of direct HIV Infection, secondary infectious or malignant processes, or as a complication of therapies for AIDS. In this context, the adrenals are most important because unrecognized adrenal insufficiency in AIDS inevitably will lead to rapid demise of the patient. Fortunately, frank adrenal insufficiency is most uncommon. Also. uncommon are clinical manifestations of other endocrine organ dysfunction, but the thyroid gland, pancreas, and gonads are all potential targets. Electrolyte abnormalities and disordered energy metabolism are additional potential complications of HIV infection

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

This review highlights recent advances in the understanding of the biosynthesis of the adrenal-specific steroid hormones, the mineralocorticoids and glucocorticoids. The genes, or complementary DNAs encoding each of the enzymes required for catalyzing biosynthesis of aldosterone and cortisol from cholesterol were all cloned before 1992-As each of the gene sequences and structures has become known, mutations have been found in patients with corresponding specific inherited disorders of steroid biosynthesis, simultaneously defining the genetic basis of the disorder and confirming thein vivorole of the enzyme. Isolation of the steroidogenic genes and characterization of their promoters is now leading to the identification of the transcription factors required for their expression.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Six structurally distinct binding proteins for the insulin-like growth factors (IGFs) have been identified. The IGF binding proteins (IGFBPs), IGFBP-1 through IGFBP-6, modulate the Bioavailability and actions of IGFs in the circulation and the extracellular environment. IGFBP-1 is metabolically regulated and suppressed by insulin administration, except when hypoglycemia ensues. IGFBP-3 is the major IGF carrier in serum, where it is found complexed with an acid-labile glycoprotein. The roles of IGFBP-2 and other circulating IGFBPs are as yet poorly defined. Most cell types secrete IGFBPs, with fibrobiasts, hepatocytes, osteobiasts. and granulosa cells being particularly well-studied sources. The actions of IGFBPs in local IGF regulation are complex and are modified by limited proteolysis, phosphorylation, and other posttranslational events. The current intense research focus on the IGF-IGFBP axis will lead to a better understanding of the regulation of IGF action in ceil growth and metabolism and allow the therapeutic utility of the IGFs to be optimized.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Tissue metabolism of ligand is now established as an important prereceptor signaling pathway in endocrinology. 11β-Hydroxysteroid dehydrogenase activity, by inactivating cortisol and corticosterone, regulates ligand access to the glucocorticoid receptor and in the kidney and distal colon enables the much lower circulating concentrations of aldosterone to occupy the mineralocorticoids receptor. Two distinct 5α-reductase and 5 deiodinase enzymes, respectively, convert testosterone and rhyroxine to the potent ligands dihydrotestosterone and triiodothyronine iodothronine. Other enzymes, such as aromatase, and 3β- and 17β-hydroxysteroid dehydrogenase, also play a key role in mediating peripheral sex hormone action. Finally, an uncharacterized isomerase, by catalyzing the conversion of ail-transretinoic acid to 9-cisretinoic acid, dictates specificity of retinoid action. This review focuses on the recent clinical and scientific advances in this area. The role of these enzymes in normal physiology is apparent, and alterations in their activities can have profound consequences Factors that control the tissue expression and activity of these enzymes are emerging and will be a major impetus of research in the future.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

This review covers recent data concerning normal patterns of linear and head circumference growth, changes in body composition and shape, and bone mineral accretion in normal infants, children, and adolescents. The importance of the normal pubertal process on bone mineralization is emphasized. The roles of growth-determining genes, exercise, and nutrition are discussed. The long-term adverse consequences of very low (but gestationally appropriate) birth weight and of intrauterine growth retardation on adult height are described. The growth-inhibiting effects of chronic renal insufficiency and inflammatory bowel disease present important therapeutic challenges. On the other hand, asthma that is treatabte by inhaled glucocorticoids does not appear to significantly impair attainment of genetic height potential. Poverty, homelessness. neglect, abuse, and lead exposure result in slow linear growth during childhood.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Normal production, regulation, serum binding, and action of growth hormone (GH) have been studied extensively during the past several years. The use of sophisticated deconvolution analysis to assess GH pulsatility, the importance of sex steroids in modulating GH secretion at puberty, the recognition of important relationships between the glycoprotein circulating GH-binding protein—highly similar to the extracellular portion of the GH receptor—and GH production and nutrition, and the mechanisms of GH action at the cellular level are briefly reviewed. Responses to exogenous GH are discussed in conditions of GH deficiency, Turner syndrome, chronic renal disease, and glucocorticoid therapy. Clinical uses of exogenous insulin-like growth factor-I are noted

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Recent clinical and biochemical discoveries bring insight into normal and abnormal puberty. Analogues of gonadotropin-releasing hormone are used for diagnosis and therapy and shed light on normal physiologic processes of puberty. Insight into the etiology of unique disorders of puberty arises from recent molecular biology studies. Clinical studies using modem assay techniques supplement the information first presented decades ago.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID