Unexpected activation of pituitary-adrenal axis in healthy young and elderly subjects during somatostatin infusion

In this study we explored, in man, the effect of acute attenuation of growth hormone (GH) release induced by somatostatin (SRIH) on ACTH and cortisol plasma levels. Sixteen young (8 women, aged 23-32 years, and 8 men, aged 18-27 years) and 14 elderly (8 women, aged 65-82 years, and 6 men, aged 65-70 years) healthy subjects volunteered to participate in this investigation. Each subject was tested on two separate occasions by: (1) a 90-min i.v. infusion of SRIH given in 50 ml 0.9% saline delivered at a rate of 9 microg/kg/h, and (2) a 90-min i.v. infusion of isovolumetric amounts of 0.9% saline. Plasma GH, ACTH, cortisol and glucose concentrations were determined prior and up to 180 min after SRIH or saline infusion. SRIH induced a significant (p < 0.05) decrease in plasma GH levels from basal values of 0.6 +/- 0.15 and 0.5 +/- 0.15 microg/l to nadir values 0.25 +/- 0.1 and 0.2 +/- 0.1 microg/l in young and elderly subjects, respectively. The administration of SRIH was associated with a clear-cut increase in plasma ACTH levels both in young (peak, 10.6 +/- 1.6 pmol/l; AUC, 558.6 +/- 147.5 pmol/l/h) and in elderly (peak, 21.3 +/- 5.6 pmol/l; AUC, 841.9 +/- 153.8 pmol/l/h) subjects with a significant (p < 0.01) difference as compared to saline infusion. Consistent with these results, SRIH infusion resulted in an unequivocal rise in plasma cortisol levels both in young (peak, 394.8 +/- 36.4 nmol/l; AUC, 18,591.62 +/- 1,372.45 nmol/l/h) and in elderly (peak, 585.6 +/- 51.5 nmol/l; AUC, 24,871.05 +/- 1,837.03 nmol/l/h) subjects. The ACTH and cortisol responses to SRIH were significantly (p < 0.05 and p < 0.01) higher in elderly than in young subjects. No sex-related differences occurred in the SRIH-induced activation of hypothalamic-pituitary-adrenocortical (HPA) axis. We conclude that (1) infusion of SRIH, at a dose that inhibited basal GH secretion, was associated with an activation of HPA axis, and (2) this response was higher in elderly individuals compared with younger adults. The reason for this novel and unexpected SRIH effect is presently unclear; however, the latter may be mediated, at least in part, by some central nervous system ACTH-releasing mechanisms activated by SRIH-induced decrease in GH secretion

European Confederation of Medical Mycology (ECMM) prospective survey of cryptococcosis : report from Italy

Italy is one of the countries participating in a prospective epidemiological survey of cryptococcosis set up in July 1997 by the European Confederation of Medical Mycology (ECMM). Over a 30-month period 156 cases, all caused by Cryptococcus neoformans var. neoformans, were reported by 29 hospitals in 9 regions. An ECMM questionnaire was used to report the clinical presentation and the diagnostic and treatment approach used. Cryptococcosis was associated with HIV infection in 147 cases and was considered indicative of AIDS in 65%. The estimated incidence in the Lombardy region was 0.85/100 in the AIDS population. One isolate from each of 129 patients was serotyped and genotyped. PCR fingerprinting using the primer (GACA)4 proved to be a more reproducible typing method than the slide agglutination test. Genotypes VN1 (serotype D), VN6 (serotype A) and VN3-VN4 (serotype AD hybrid strains) occurred in Italy at similar levels nationwide, but VN1 (D) was prevalent in the North. In vitro resistance to antifungals was uncommon