Melatonin Shifts Human Orcadian Rhythms According to a Phase-Response Curve

A physiological dose of orally administered melatonin shifts circadian rhythms in humans according to a phase-response curve (PRC) that is nearly opposite in phase with the PRCs for light exposure: melatonin delays circadian rhythms when administered in the morning and advances them when administered in the afternoon or early evening. The human melatonin PRC provides critical information for using melatonin to treat circadian phase sleep and mood disorders, as well as maladaptation to shift work and transmeridional air travel. The human melatonin PRC also provides the strongest evidence to date for a function of endogenous melatonin and its suppression by light in augmenting entrainment of circadian rhythms by the light-dark cycle.     

Congenital hypoaldosteronism. Thirteen year follow-up in identical twins.

Identical male twins suffering from congenital hypoaldosteronism due to a rare adrenal enzyme deficiency between corticosterone and aldosterone were followed-upfrom birth till their present age of 13 years. The symptoms of salt loss disappeared and normal growth rate resumed following treatment with DOCA and salt supplementation. Discontinuation of mineralocorticoid administration at the age of 7 years resulted during a 5-year period in a marked decline in their growth rate. Labororatory data revealed a persistent, albeit less pronounced, metabolic impairment. Mineralocorticoid administration was resumed and the twins entered normal puberty and increased their growth rate, emphasizing their need for continued mineralocorticoid administration to maintain adequate growth rate and development.