In the present study the effects of artificial magnetic fields on pineal serotonin-N-acetyltransferase (NAT) activity and melatonin content in male Sprague-Dawley rats were investigated to study the secretory activity of the pineal gland. Experimental inversion of the horizontal component of the natural magnetic field, performed at night-time, led to a significant decrease of both parameters investigated. During day-time, this effect was less conspicuous. During night-time, inversion of the horizontal component is followed by a reduced pineal secretory activity for about 2 h. After 24 h exposure to the inverted horizontal component, return to the natural condition was followed by a renewed clear depression of pineal NAT activity and melatonin content, indicating that the main stimulus is not the inverted magnetic field itself but rather its change. Changing the inclination of the local magnetic field from 63 degrees to 58 degrees, 68 degrees or 78 degrees, respectively also decreased the secretory activity of the rat pineal gland.
Management of craniopharyngiomas is still controversial. 28 children with this tumor were studied. GH deficiency was present in 22 patients following surgery, 10 of these GH-lacking patients had normal or accelerated growth (usually associated with rapid weight gain) postoperatively. Somatomedin levels were normal in three of six normally growing patients. After craniotomy their basal and TRH-stimulated prolactin levels were in the normal range, but their insulin secretion was markedly increased. Postoperatively there was a significant correlation between peak insulin levels following arginine infusion and growth velocity in all patients. Complete tumor removal could be performed in 28% of our patients. Altogether 36% of all patients had at least one tumor recurrence. Recent literature with the addition of our series showed tumor recurrence in 22% of patients with "total" tumor excision and in 72% of patients with partial tumor removal. Radiotherapy seems to be capable of destroying craniopharyngioma tissue. The recurrence rate was only 26% in patients with subtotal excision plus radiotherapy. Unless radical tumor removal can be attempted with safety, subtotal tumor removal plus radiotherapy appears to be the treatment of choice for craniopharyngioma.
Cushing's disease resulting from intrasellar corticotropin-releasing hormone (CRH)-secreting gangliocytomas is very rare, and only two such cases have been reported in the literature to date. The authors present a third case in which an adrenocorticotropic hormone-secreting pituitary adenoma was found in addition to a gangliocytoma in a 10-year-old girl with clinical and endocrinological symptoms of Cushing's disease. Computed tomographic and magnetic resonance imaging scans showed a suprasellar and parasellar tumor. A green-colored, heterogeneous tumor and a small adenoma were removed transsphenoidally. Histological examination revealed a large gangliocytoma immunoreactive for CRH and a small, mucoid cell pituitary adenoma immunoreactive for ACTH. This is the first case of such a tumor causing Cushing's disease in a child. It might exemplify induction of an ACTH-secreting pituitary adenoma by means of chronic overstimulation of CRH.
To delineate the development of melatonin (MLT) production during childhood, we measured the excretion of MLT and 6-hydroxymelatonin sulfate (MLTS) in the urine of children (n = 134) from the 26th week of gestation until the age of 20 years. MLTS excretion showed a diphasic pattern with declining values in preterm babies with lowest values around term. After birth, the values remained low for the first 6 months of life. The highest values were reached between 4 and 7 years of age with a smooth but steady decline thereafter. A night-day difference was not detectable before the age of 6 months; the greatest night-day variations occurred at the time of the highest MLTS excretions. The MLT values showed an identical pattern but with amounts 1,000 times smaller; the ratio of MLTS to MLT increased from 40:1 in preterm babies to 900:1 in prepubertal children. In summary, the MLT/MLTS excretion exhibits the highest activity with respect to total secretory capacities as well as night-day differences at the time of gonadal quiescence during childhood. The strong inverse correlation of MLT and MLTS excretion with the hypothalamic-pituitary-gonadal activity points to a causal relationship between pineal gland activity and pubertal development.
Abstract. Stahnke, N., Ilicki, A. and Willig, R. P. (Department of Paediatrics, University Hospital, Hamburg, West Germany). Effect of cyproterone acetate (CA) on growth and endocrine function in precocious puberty. Acta Paediatr Scand, Suppl. 277: 32, 1979.–16 girls with precocious puberty have been studied. Following low dosage cyproterone acetate (CA) therapy (mean daily dosage 65 mg/m2 BSA) a beneficial effect on growth and skeletal maturation was observed. During high dosage therapy (150 mg/m2 per day) endocrinological studies were performed in 10 of these patients. There was no significant difference in HGH levels (insulin‐and arginine‐test), T3 and TSH values (TRH‐test) between patients and controls, T4 concentration was significantly increased. Basal prolactin levels and prolactin response to TRH was definitely elevated. Oral glucose load and arginine infusion resulted in a significantly enhanced insulin release. There was a significant reduction in basal LH levels and an increase in FSH response to LH‐RH. Basal and diurnal plasma cortisol values were markedly reduced and the cortisol release due to corticotrophin injection, (lsinevasopressin (LVP) injection and insulin‐hypoglycemia as well. A definite increase in basal ACTH levels was observed, during LVP‐and insulin‐hypoglycemia test ACTH concentrations were within or significantly above normal range. In our patients a primary adrenocortical insufficiency due to CA treatment was evident.
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