Clinical endocrinology
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Clinical endocrinology · Aug 1995
Randomized Controlled Trial Comparative Study Clinical TrialOestrogen effects on calcitriol levels in post-menopausal women: a comparison of oral versus transdermal administration.
In some studies oral oestrogen therapy in post-menopausal women has been shown to increase both total and free 1,25-dihydroxyvitamin D (calcitriol) levels, suggesting that oestrogen therapy may prevent post-menopausal bone loss, in part, by increasing calcium absorption as a result of raised calcitriol levels. Transdermal oestrogen, however, has not been shown to increase calcitriol levels although it prevents bone loss. These two routes of administration have not previously been directly compared in the same subjects at bioequivalent doses as assessed by FSH and LH suppression. ⋯ These results show that in this study the total calcitriol rose after oral but not transdermal oestrogen due to a rise in vitamin D-binding protein. Free calcitriol was not affected by oral or transdermal oestrogen treatment despite a fall in plasma phosphorus and a rise in PTH, both of which are considered agonists for calcitriol production. We may therefore conclude that neither oral nor transdermal oestrogen replacement routinely stimulates free calcitriol levels. In the studies where a rise in free calcitriol was noted, the degree of suppression of bone resorption by oestrogen may have been greater, thus producing a larger demand for calcium due to filling of a larger bone remodelling space with consequent stimulation of calcitriol levels.
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Clinical endocrinology · Aug 1995
Temperature-induced down-regulation of the glucocorticoid receptor in peripheral blood mononuclear leucocyte in patients with sepsis or septic shock.
Activation of the hypothalamic-pituitary-adrenal axis is of vital importance during critical illness. We have studied the adaptive mechanisms which occur at the level of the glucocorticoid receptor in glucocorticoid target tissues in patients with sepsis or septic shock. ⋯ There is no obvious regulation of the number of glucocorticoid receptors by plasma cortisol concentrations in vivo. The decreased affinity of the glucocorticoid receptor together with the negative correlation between hyperthermia and the number of glucocorticoid receptors in patients with sepsis or septic shock suggest that hypothalamic-pituitary-adrenal axis activation during critical illness is accompanied by peripheral adaptation in glucocorticoid receptor number and affinity.
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Clinical endocrinology · Jul 1995
Investigation, management and therapeutic outcome in 12 cases of childhood and adolescent Cushing's syndrome.
Cushing's syndrome in childhood and adolescence is rare. We analysed the clinical presentation, investigation, management and therapeutic outcome in 12 paediatric patients with Cushing's syndrome. ⋯ This series describes the clinical features, aetiologies and management of juvenile Cushing's syndrome. Investigation with low and high-dose dexamethasone suppression tests and hCRH test identified the aetiology in each case. Collaboration between paediatric and adult endocrine units together with an experienced neurosurgeon and a radiotherapist contributed to the successful therapeutic outcome of these patients.
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Clinical endocrinology · May 1995
Prevalence of sporadic medullary thyroid carcinoma: the importance of routine measurement of serum calcitonin in the diagnostic evaluation of thyroid nodules.
The prevalence of sporadic forms of medullary thyroid carcinoma (MTC) has been studied in patients living in an area of moderate iodine deficiency. Such forms of MTC are usually diagnosed after surgery and have little chance of definitive cure. Using the measurement of basal serum calcitonin (CT) levels in a large series of patients with both thyroid disease and normal 24-hour urinary iodine excretion, we assessed the prevalence of MTC and, in patients affected with the disease, we also evaluated the stage of the disease according to surgical findings and post surgical plasma CT levels. ⋯ This study demonstrates a surprisingly high prevalence of sporadic forms of medullary thyroid carcinoma in patients with nodular thyroid disease. Such forms of medullary thyroid carcinoma seem to be unrelated to iodine intake and may be pure or mixed with a follicular carcinoma. In these mixed thyroid carcinomas, only the neoplastic follicular pattern was seen on both cytological and histological examination. Routine measurements of serum calcitonin levels should therefore be considered an integral part of the diagnostic evaluation of thyroid nodules. Indeed, increasing the accuracy of diagnosis of medullary thyroid carcinoma encourages the surgeon to perform more radical treatment, thus achieving more frequent normalization of post-operative serum calcitonin levels.
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Clinical endocrinology · Jan 1995
Randomized Controlled Trial Clinical TrialReplacement treatment with biosynthetic human growth hormone in growth hormone-deficient hypopituitary adults.
The physiological role of growth hormone in adult life has recently attracted increased interest. We have studied the clinical effects and the effects on body composition of prolonged replacement with biosynthetic human GH in a large number of hypopituitary adults. ⋯ Growth hormone replacement therapy in adults for 6 months increased lean body mass, total body water and exercise tolerance, and decreased body fat. Growth hormone replacement for longer than 6 months maintains the advantageous effects seen in shorter-term studies and may have additional effects on body fat distribution, muscle strength and psychological well-being.