Melatonin replacement corrects sleep disturbances in a child with pineal tumor.

A child with a germ cell tumor involving the pineal region had marked suppression of melatonin secretion associated with severe insomnia. Exogenous melatonin (3 mg in the evening) for 2 weeks restored sleep continuity, as demonstrated by objective monitoring of rest-activity cycles. This case report provides direct evidence of the essential role of melatonin in normal sleep.

SPECT quantitation of iodine-131 concentration in phantoms and human tumors.

The validity of SPECT measurement of iodine-131 (131I) concentration was tested in vitro in phantoms and in vivo by measuring bladder urine concentrations. Phantom studies comparing known and SPECT measured concentrations showed a good correlation for 131I (r = 0.98, s.e.e. = 20.94 counts/voxel) for phantoms of 25 to 127 cc and concentrations of 0.13 to 9.5 microCi/cc. The in vivo, in vitro correlation of 131I concentrations in the urine was also good (r = 0.98, s.e.e. = 0.677 microCi/cc). Quantitative SPECT was used to calculate the effective half-life and dosimetry of radioiodine in 12 sites of thyroid carcinoma in seven patients. SPECT was also used to determine the dosimetry of [131I]MIBG (metaiodobenzylguanidine) in two patients with carcinoid, two with neuroblastoma, and one with pheochromocytoma. The radiation dose for thyroid carcinoma metastases varied between 6.3 and 276.9 rad/mCi. The dose from MIBG varied between 13.4 and 57.8 rad/mCi. These results indicate the validity of quantitative SPECT for in vivo measurement of 131I and the need to measure the concentration of 131I in individual human tumor sites.

Computer-assisted image analysis can aid the prognostication of advanced-stage neuroblastomas.

PURPOSE: The aim of this work was to detect nuclear parameters related to the prognosis of patients with stage III, IV or DS neuroblastomas. METHODS: Histological sections of 25 operation specimens obtained from children with advanced-stage neuroblastomas were subjected to computer-assisted image analysis. Statistical relationships between nuclear descriptors of the tumor cells and patients' clinical outcome were determined. RESULTS: The coefficient of variability of the mean nuclear area the mean nuclear elongation factor, and the mean nuclear averaged Feret diameter of the neuroblastoma cells were ascertained to be discriminators separating high-grade from low-grade tumors. CONCLUSIONS: The histomorphometrically gauged nuclear parameters may help oncologists to assess the prognosis of patients with advanced-stage neuroblastoma.

Pseudo-precocious puberty in a male patient and the melatonin-testosterone relationship.

We describe a 14 year-old boy with a pineal germ cell tumor which secreted beta HCG. Serum testosterone levels were markedly elevated with concomitant decreased LH secretion. 24-h serum melatonin levels were suppressed and lacked the normal nocturnal rise. Pineal radiation therapy was followed by tumor regression and the diminution of beta HCG stimulated testosterone, which in turn inhibited melatonin and LH. When beta HCG and testosterone were normalized after tumor radiation, a recovery of normal melatonin and LH secretory pattern occurred. These results indicate that circulating testosterone down-regulates pineal melatonin.