Effect of a melatonin-free extract from bovine pineal on plasma and urinary steroids and on serum prolactin in hirsute amenorrheic adolescents.

Basal and post-suppressive dexamethasone (dxm) levels of some urinary androgen metabolites, plasma testosterone (T), 17 hydroxyprogesterone (17 OHP) and of basal serum prolactin were determined in 34 hirsute amenorrheic adolescents aged 13-17 in whom a five day course of bovine pineal extract (4 ml a day i.m.) was instituted. No convincing effect of pineal extract administration on plasma T and 17 OHP and on serum prolactin was detectable in most of pineal-treated patients. Suppressibility to dxm of plasma T and 17 OHP was not a relevant index of both the origin of androgens or the clinical course of the patients.

Gonadotropin secretion dynamics in patients with Klinefelter's syndrome in relation to age.

In 28 chromatin-positive patients distributed into age-decade lots, the circulating levels of gonadotropins as shown by radioimmunoassay (RIA), were higher than normal. FSH was especially high while LH had significant fluctuations between the lots. A hypothalamic determinism for these anomalies is suggested.

Myasthenia in patients with dermatomyositis: clinical, electrophysiological and ultrastructural studies.

In 4 patients with clinical signs of dermatomyositis, confirmed by electromyography and muscle biopsy, a form of muscle fatigue was detected which was expressed clinically by predominantly proximal motor deficit, with phonation and deglutition disturbances, slightly influenced by prostigmine. In all patients, stimulation of the ulnar nerve at 3--10 Hz induced a decrement of muscle-evoked potentials in abductor digiti minimi and at 15--50 Hz an increment at the end of the trains (1.2 sec in duration) of repetitive stimulation (preceded in two cases by a decrement in the response to the fifth stimulus in the train). Stimulation at 30 Hz for 10 sec resulted in a transient facilitation, followed (at 3 Hz stimulation) by postactivation exhaustion which disappeared after 5--15 min. The post-tetanic facilitation, the incremental response and the myasthenic symptoms reverted to normal under treatment with corticosteroids, an immunosuppressor agent and guanidine hydrochloride. A mixed, pre- and postsynaptic mechanism is presumed to underlie the muscle fatigue in our patients. Electron microscopy of muscle biopsies disclosed zones of necrosis and, in incipient stages, large agglomerations of glycogen that had disorganized the structure of myofibrils. The end-plates in the biopsies were larger than normal and the cholinesterase reaction was hyperactive. Serum immunoelectrophoretic and electrophoretic data--increase of IgG and IgM, decrease of IgA and hypergammaglobulinaemia -- point to a possible autoimmune mechanism of the neuromuscular disorders in our patients.