ISSN:1051-2144    

出版商:OVID    

年代:1994

数据来源: OVID

ISSN:1051-2144    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The diagnostic evaluation of Cushing's syndrome proceeds in two stages: first the definitive diagnosis of pathological hypercortisolism (Cushing's syndrome), and second the differential diagnosis of pituitary, adrenal, and ectopic causes. Proper initial diagnosis of Cushing's syndrome depends on correlation of clinical data with results of 24-hour urine free cortisol and responses to low-dose dexamethasone suppression. Although responses to corticotropin-releasing hormone (CRH) administration differ between patients with Cushing's syndrome and those with pseudo-Cushing's states such as stress, depression, and alcoholism, this test is not, at present, useful in the initial diagnosis of Cushing's syndrome. When the diagnosis of Cushing's syndrome has been secured, measurement of ACTH or β-LPH provides a reliable distinction between ACTH-dependent and adrenal-based etiologies. New criteria for the standard 48-hour high-dose dexamethasone test identify approximately 80% of patients with Cushing's disease. The CRH stimulation test may provide additional diagnostic accuracy. Inferior petrosal sinus sampling is a highly accurate test for ACTH-dependent Cushing's syndrome when other test results are inconclusive.

ISSN:1051-2144    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Albright hereditary osteodystrophy (AHO) is an autosomal dominant inherited disorder with characteristic skeletal and developmental defects and in some patients target tissue resistance to multiple hormones. Patients with AHO typically have short stature, a round face, obesity, brachydactyly, and subcutaneous ossifications. Most subjects with AHO also show resistance to parathyroid hormone and other hormones that all act via stimulation of adenylyl cyclase and production of the second messenger cAMP. This form of AHO has been termed pseudohypoparathyroidism (PHP) type Ia. The molecular basis of AHO is deficiency of G,α the α subunit of the guanine nucleotide-binding protein that couples cell surface receptors for many hormones and neurotransmitters to the stimulation of adenylyl cyclase. Remarkably, individuals with PHP type Ia often have relatives with AHO who do not develop hormone resistance despite G,α deficiency. This variant of AHO has been termed pseudo-pseudohypoparathyroidism. A variety of unique point mutations and small deletions in the G,α gene have been identified in affected members of AHO kindreds. A thorough clinical, biochemical, and genetic evaluation is required to distinguish AHO from other forms of PHP. Patients with PHP type Ic have somatic defects that are similar to those in AHO and manifest resistance to multiple hormones, yet they have apparently normal G,α activity. These subjects may have a defect in the adenylyl cyclase catalytic unit. In patients with PHP type Ib, hormone resistance is limited to parathyroid hormone (PTH) target tissues. These subjects lack somatic abnormalities and have normal levels of G,α. A defect in the PTH receptor may account for PTH resistance. Finally, subjects with PHP type II may have an acquired disorder resulting from vitamin D deficiency.

ISSN:1051-2144    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Cushing's syndrome is reported in close to 80 infants under 1 year of age. Infants present with obesity, growth failure, and cushingoid facies. Some are virilized. Adrenal tumors account for the majority of cases. The second most common cause is an adrenal hyperplasia or dysplasia that is usually nodular and may be secondary to a mutation in the stimulatory guanine nucleotide-binding protein. Pituitary adenomas and ectopic ACTH production are exceedingly rare in this age group. An infant with nodular hyperplasia is presented and the clinical features, etiology, diagnosis, and treatment are discussed.

ISSN:1051-2144    

出版商:OVID    

年代:1994

数据来源: OVID

ISSN:1051-2144    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The overall cure rate for childhood cancer is now over 60%, and for some tumors it is over 90%. It has been estimated that by the year 2000 at least 1 in 1000 young adults will have been cured of childhood cancer. This improved survival has stimulated great interest in the adverse late effects of radiotherapy and cytotoxic chemotherapy on growth and the endocrine system. Radiation therapy may directly impair hypothalamic, pituitary, thyroid, and gonadal function, or alternatively, it may induce the development of hyperparathyroidism and thyroid adenomas or carcinomas. Cytotoxic chemotherapy may damage the gonad, and both irradiation and cytotoxic chemotherapy may interfere with the normal growth of bone. A variety of clinical presentations which require endocrine expertise in management may result from these complications of treatment, including short stature, failure to undergo normal pubertal development, precocious puberty, hyperparathyroidism, hypothyroidism, thyroid tumors, gynecomastia, infertility, and varying degrees of hypopituitarism.

ISSN:1051-2144    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Cytokines are protein molecules that are produced in response to a variety of stimuli by many different cells and are responsible for coordination of the immune and inflammatory responses. Tumor necrosis factor, interleukins, and interferons are some of the well-characterized cytokines. These cytokines have many diverse functions and act on nearly every tissue and organ system, but are most noted for their effects on the cells of the immune system. The action of each cytokine on its target cell is mediated through binding to specific cell surface receptors; however, several structurally distinct cytokines may exert similar biological effects, even though they bind to different receptors. Cytokines act mainly in a paracrine or autocrine fashion on neighboring cells, but they may also be released into the circulation and act as hormones on distant cells and organs. The host response to infection is usually associated with multiple disturbances in intermediary metabolism. Infection or endotoxin administration stimulates the production of numerous cytokines by host cells, and these cytokines are involved in mediating many of the pathophysiological responses that occur during the course of infection. Recent studies have shown that cytokines also have significant effects on lipid, glucose, and protein metabolism. This review will focus on the metabolic changes that occur during infection and the role of cytokines in mediating these alterations.

ISSN:1051-2144    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Growth hormone-releasing hormone (GHRH) is limited as a diagnostic tool in both growth hormone (GH) deficiency and acromegaly. Measurement of a GHRH level may be helpful in patients with acromegaly suspected to have ectopic production of this peptide. The greatest potential of GHRH lies in its ability to be used as a therapeutic agent, either in GH-deficient states or, possibly, as an antagonist in acromegaly. Either a long-acting preparation or a preparation formulated to be active orally would greatly potentiate the clinical application of this peptide.

ISSN:1051-2144    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The choices available for treating Graves' disease have not changed dramatically in the last 20 years. The major shift has been a progressive diminution in the use of surgery as a first-line therapy. Refinements in the use of antithyroid drugs and the availability of potent β-adrenergic blockers have simplified medical management. However, most patients eventually receive radioiodine therapy and, of these, approximately 50% become hypothyroid. The major advances in unraveling the pathogenesis of Graves' disease have not yet improved the therapeutic armamentarium or outcome nor significantly sharpened the ability to predict which patients will stay in remission after antithyroid drug therapy.

ISSN:1051-2144    

出版商:OVID    

年代:1994

数据来源: OVID