The Journal of clinical endocrinology and metabolism
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J. Clin. Endocrinol. Metab. · Jul 1999
Phytoestrogens alter adrenocortical function: genistein and daidzein suppress glucocorticoid and stimulate androgen production by cultured adrenal cortical cells.
Phytoestrogens influence a variety of biological processes. As 17beta-estradiol alters adrenocortical cell function, we examined whether the dietary phytoestrogens, genistein and daidzein, have related effects. In cultured human fetal and postnatal adrenal cortical cells, genistein and daidzein (both 0.4-40 micromol/L) decreased ACTH-stimulated cortisol production to basal levels (ED50, 1-4 micromol/L). ⋯ However, genistein and daidzein specifically inhibited the activity of 21-hydroxylase (P450c21); the activities of other steroidogenic enzymes were not affected. Thus, phytoestrogens may decrease cortisol synthesis by suppressing the activity of P450c21 and, as a consequence, increase DHEA/DHEA-S synthesis by shunting metabolites away from the glucocorticoid synthetic pathway. Therefore, consumption of foods containing phytoestrogens may alter adrenocortical function by decreasing cortisol and increasing androgen production.
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J. Clin. Endocrinol. Metab. · Feb 1999
Multicenter StudyDiagnosis and management of Cushing's syndrome: results of an Italian multicentre study. Study Group of the Italian Society of Endocrinology on the Pathophysiology of the Hypothalamic-Pituitary-Adrenal Axis.
The past 45 yr' experience with Cushing's syndrome (CS) has led to the awareness of its complex nature and, by the same token, brought about an increase in the diagnostic and therapeutic dilemmas. We carried out a retrospective multicentre study on the diagnostic work-up and treatment in 426 patients with CS, subdivided as follows: 288 with Cushing's disease (CD), 80 with an adrenal adenoma, 24 with an adrenal carcinoma, 25 with ectopic ACTH and/or CRH secretion, and 9 with ACTH-independent nodular adrenal hyperplasia. Normal urinary free cortisol (UFC) values among multiple collections were recorded in about 10% of patients with CS. ⋯ In summary, an accurate selection of the available diagnostic tools leads to the correct diagnosis in the majority of patients with CS. The therapeutic options for CD, adrenal carcinoma, and ectopic secretion are, as yet, not fully satisfactory. The high incidence of relapse after pituitary surgery calls for a prolonged follow-up.
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J. Clin. Endocrinol. Metab. · Feb 1999
Randomized Controlled Trial Clinical TrialEffects of calcium supplementation on calcium homeostasis and bone turnover in lactating women.
Lactation is a time of calcium flux, because women secrete approximately 210 mg calcium/day in breast milk, and they experience a transient bone loss. The objectives of this study were to determine the effect of calcium supplementation on adaptive responses in calcium homeostasis during lactation and after weaning. Two cohorts of women participated in a 6-month randomized calcium supplementation trial. ⋯ At 6 months, the calciuric response to calcium supplementation was less in lactating (compared with nonlactating) women (P = 0.06). Biomarkers of bone turnover were higher in lactating than in nonlactating women during lactation and after weaning but were not effected by calcium supplementation. Calcium supplementation has little effect on lactation-induced changes in the calcium economy.
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J. Clin. Endocrinol. Metab. · Jan 1999
Loss of heterozygosity on chromosome 11q13 in two families with acromegaly/gigantism is independent of mutations of the multiple endocrine neoplasia type I gene.
Familial acromegaly/gigantism occurring in the absence of multiple endocrine neoplasia type I (MEN-1) or the Carney complex has been reported in 18 families since the biochemical diagnosis of GH excess became available, and the genetic defect is unknown. In the present study we examined 2 unrelated families with isolated acromegaly/gigantism. In family A, 3 of 4 siblings were affected, with ages at diagnosis of 19, 21, and 23 yr. ⋯ Sequencing of the MEN-1 gene revealed no germline mutations in either family, nor was a somatic mutation found in tumor DNA from one subject in family A. The integrity of the MEN-1 gene in this subject was further supported by demonstration of the presence of MEN-1 messenger ribonucleic acid, as assessed by RT-PCR. These data indicate that loss of heterozygosity in these affected family members appears independent of MEN-1 gene changes and suggest that a novel (tissue-specific?) tumor suppressor gene(s) linked to the PYGM marker and expressed in the pituitary is essential for regulation of somatotrope proliferation.
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J. Clin. Endocrinol. Metab. · Nov 1998
Clinical Trial Controlled Clinical TrialLactate and glycerol release from the subcutaneous adipose tissue of obese urban women from South Africa; important metabolic implications.
Interstitial glycerol and lactate production was measured in the s.c. adipose tissue of two anatomical regions in 10 obese urban black women (BW) and 10 obese urban white women (WW) matched for age, body mass index, waist-hip ratio, diet, and physical activity. This was done with the s.c. microdialysis technique and combined with adipose tissue blood flow (ATBF) rates calculated from 133Xe clearance. Biochemical measurements were done in the postabsorptive and postprandial state. ⋯ WW have more visceral fat (150 +/- 2.0 vs. 110 +/- 5.0 cm2, P < 0.05). In conclusion, the insulinopenic BW have a brisker lipolysis and ATBF and release more glycerol and lactate from their sc adipose tissue, both in the postabsorptive state and after an oral glucose tolerance test. These variations in adipose tissue metabolism may contribute to differences observed in the disease profiles of these two groups of women.