ISSN:1068-3097    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:1068-3097    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

A signal transmitting metabolic information from peripheral tissue to the human brain has long been looked for. Since the recent discovery of leptin, the product of the obesity (ob) gene, and its receptor, a rapidly growing body of research has begun to elucidate the role of leptin in body composition and reproduction. In prepubertal girls and boys, leptin concentrations increase slowly with age and body fat mass. In boys, this increase is interrupted in early puberty, when testosterone and lean body mass increase. In girls, leptin along with body fat mass continue to increase during puberty. The therapeutic response to leptin in a child with leptin deficiency confirms the importance of leptin in the regulation of appetite and body weight in humans. The first long-term results of leptin treatment indicate that adequate serum leptin concentrations are required for normal pubertal development. Whether leptin is a primary signal in the onset of human puberty or acts in a permissive way as one of several metabolic factors remains to be studied.

ISSN:1068-3097    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The dramatic bone growth during puberty encompasses three distinct but integrated processes: accelerated linear growth, bone maturation, and rapid acquisition of bone mass. Compelling evidence indicates that the estrogen-primed enhancement of the axis of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) in both sexes is the main mediator of the accelerated linear growth and increase in bone dimensions during early puberty and midpuberty. The surge in estrogen at menarche in girls and in late puberty in boys inhibits growth, closes the epiphyses, and increases true volumetric bone mineral density (vBMD). Knowledge of estrogen’s central role in these aspects of bone growth has important therapeutic implications for the management of pubertal disorders.The potential impact of calcium intake and exercise on bone mass accrual during puberty is generally supported. Genetic polymorphisms in genes thought to influence bone mass might ultimately be used in combination with known hormonal and environmental risk factors and clinical parameters to identify adolescents at risk for osteoporosis for early intervention.

ISSN:1068-3097    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Type 2 diabetes has traditionally been considered an adult disease, with increasing incidence in older age groups. However, a number of clinical and epidemiologic reports have suggested an increasing occurrence of type 2 diabetes over time among children and adolescents. Among Native Americans, the prevalence is approaching 5% in some age groups, and other minority populations are not far behind. Although the majority of children appear to have a form of diabetes that is very similar to type 2 diabetes in adults, at least two subtypes, maturity onset diabetes of the young (MODY) and “atypical diabetes,” also appear to be occurring with increased frequency. A number of attributes may indicate a predisposition to type 2 diabetes in minority youths. Significant risk factors include ethnicity, family history, obesity, low (or high) birth weight, acanthosis nigricans, and a sedentary lifestyle. To date, there is no uniform agreement on the diagnostic criteria for type 2 diabetes in adolescents. However, the combination of obesity, a positive family history of type 2 diabetes, and the absence of antibodies to islet cell antigens is highly suggestive of type 2 diabetes. Genetic testing, which is already possible for many of the MODYs, may soon allow for the identification of individuals at very high risk. As the number of treatment options for type 2 diabetes expands, it remains important to temper enthusiasm for new agents with considerable caution, in light of the possibility that unanticipated side-effects may be more common in children.

ISSN:1068-3097    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The adult height of growth hormone (GH)–treated patients with GH deficiency in some reports is still unsatisfactory, especially in patients without gonadotropin deficiency. Since total pubertal growth is not greater in children with isolated GH deficiency than in normal children on average, and since adult height in GH-treated GH-deficient patients depends on height at the onset of puberty, GH-deficient children who are short when they enter puberty will be short as adults. It seems difficult to increase total pubertal height gain by increasing GH dose during puberty. Since it has now been proven that estrogen closes the epiphyses, a rational approach for increasing adult height is to suppress sex steroid hormone and prevent epiphyseal closure by gonadotropin-releasing hormone analogue (GnRHa) and promote growth by GH. However, the adult height results in GH-deficient children after combined GH and GnRHa treatment are still controversial. Although bone age maturation decelerates during combination treatment, the pubertal growth spurt is also suppressed. Therefore, the duration of treatment must be longer to overcome the deficit caused by the loss of the pubertal growth spurt and to add extra pubertal height gain. Further well-controlled studies are necessary about the efficacy and the long-term consequences of combined GH and GnRHa treatment in isolated GH deficiency.

ISSN:1068-3097    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Insulinoma is the most common pancreatic islet cell tumor, usually presenting with symptoms of neuroglycopenia. Diagnosis depends on a high index of suspicion, together with the demonstration of endogenous hyperinsulinemic hypoglycemia. Although the requirement for preoperative localization is controversial, the minimally invasive but highly sensitive endoscopic ultrasonography allows for a more focused surgery, shorter exploration time, and the option of laparoscopic surgery. Intra-arterial calcium stimulation test can be considered in persistent or possibly multifocal disease. Intraoperative ultrasonography is also recommended to assist tumor localization and minimize complications. The use of a biostator or rapid insulin assays intraoperatively may be helpful if multiple lesions are present. The surgical cure rate for benign insulinomas approaches 100%. For those with residual or metastatic disease, symptomatic control can be achieved with diazoxide or somatostatin analogues. Multimodality therapy is usually required for metastatic disease: with control of hypoglycemia, prolonged symptom-free survival can be expected.

ISSN:1068-3097    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The health of adult hypopituitary patients with growth hormone (GH) deficiency on conventional hormone replacement therapies is impaired and their cardiovascular mortality is increased. GH-deficient adults suffer from disturbance of fuel metabolism, abnormal body composition, reduced physical performance, and impaired psychological function. These abnormalities are corrected by GH treatment, which is well-tolerated and the side effects of which are minor and dose-related. These observations provide strong evidence that adults with organic GH deficiency should have GH replacement, a principle consistent with the tenet of hormone replacement for hormone deficiency.

ISSN:1068-3097    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The use of highly active antiretroviral combination therapy (HAART) has led to a marked reduction in deaths from acquired immunodeficiency syndrome (AIDS). However, as a result of increasing viral resistance and serious metabolic toxicities associated with their long-term use, rising rates of morbidity and mortality from human immunodeficiency virus (HIV) are predicted. HAART-related lipodystrophy, which has been strongly linked to HIV-1 protease inhibitor use, is characterized by fat redistribution and profound disturbances of the lipid and glucose axes. Nucleoside analogue HIV-1 reverse transcriptase inhibitors appear to be cofactorial in its development, such that switching to protease inhibitor–sparing combinations may not be an option because of incomplete reversal of lipodystrophy and loss of virologic control. Because metabolic changes are the focus of much research at present, there has been a renewal of interest in the pathogenesis of AIDS wasting syndrome and its treatment with androgens and growth hormone.

ISSN:1068-3097    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Studies of the endocrine system, particularly the hypothalamic-pituitary-adrenal axis, in chronic fatigue syndrome are reviewed. Basal plasma cortisol concentrations have been found to be lower than in healthy control subjects in some but not all studies. The adrenocorticotropic hormone (ACTH) release induced by corticotropin-releasing hormone (CRH) is less than in control subjects and this has been interpreted to mean that hypothalamic secretion of CRH in patients with chronic fatigue syndrome is diminished. The response of serum dehydroepiandrosterone (DHEA) to ACTH in chronic fatigue syndrome patients was reduced compared with the response in normal subjects. The relationship of cortisol response to ACTH with respect to the time of sampling, sleep-wake cycles, sleep deprivation, physical inactivity, and comorbid conditions such as depression has not been fully evaluated. Growth hormone responses to insulin-induced hypoglycemia were also less than in normal controls. Hydrocortisone replacement, especially in small doses, 5 to 10 mg/day, was effective in reducing the expression of fatigue in short-term studies. Supplemental fludrocortisone was not beneficial in ameliorating symptoms in the chronic fatigue syndrome.

ISSN:1068-3097    

出版商:OVID    

年代:2000

数据来源: OVID