Regional cerebral blood flow in normal blood circulated and perfluorocarbon transfused rats

Perfluorocarbon blood substitutes have been shown to exert a protective effect in animal models of cerebral ischemia. The mechanisms by which PFCs improve cerebral hemodynamics are uncertain, however decreased viscosity, small particle size and high oxygen solubility relative to plasma are important factors. Extensive perfluorocarbon exchange transfusion (FC-43) in the rat to a hematocrit of 1%, produces a 100% increase in total cerebral blood flow (FIO2 = 1.0, CaO2 = 6 vol%). Similar increases were seen in normal blood circulated animals breathing 12% O2 (CaO2 = 12 vol%). Therefore, immediately following PFC exchange and the resulting decrease in CaO2, oxygen delivery to the brain is maintained by increasing total blood flow in a manner similar to hypoxic hypoxia.

Growth hormone therapy for patients with Turner's syndrome

The linear growth of 8 patients with Turner's syndrome during human growth hormone (GH) administration was documented. Mean growth velocity was significantly greater during GH treatment (4.9 +/- 0.8 cm/year) than before treatment (3.3 +/- 0.8 cm/year, p less than 0.001). Growth velocity was related to dosage but not correlated with chronologic age, skeletal age or weight.

A relationship between gonadotropins and visuospatial function

Follicle Stimulating Hormone (FSH) levels were negatively correlated with visuospatial function in two successive testing sessions in 32 young adult men. Men with high concentrations of FSH performed poorly on three-dimensional tests and tests of point localization. Men with low concentrations tended to perform better. Luteinizing Hormone (LH) tended to correlate positively with verbal/sequential skills and with two of the visuospatial skills for one session; testosterone was positively correlated with one spatial test. Multiple regression between the average performance on visuospatial tests and the three hormones produced Rs of 0.67 and 0.60, accounting for 39% and 29% of the variance, respectively, in Sessions 1 and 2. In women, the hormonal/behavior relationships were less clear although in many ways similar. For example, FSH was negatively correlated with one visuospatial test but only after the effects of estradiol and progesterone were partialled out. FSH was positively correlated with word fluency as was LH. With respect to sex differences women were poorer than men on the visuospatial tests and better on verbal fluency which is consistent with women's generally higher FSH levels and the negative relationship between FSH and visuospatial skills and the positive relationship with fluency.

Circadian variation of plasma 17-hydroxyprogesterone among heterozygotic carriers of 21-hydroxylase deficiency (salt-losing form)

The circadian variation of 17-hydroxyprogesterone levels in 3 male obligatory carriers of 21-hydroxylase deficiency (salt-losing form) was not significantly different from that of normal noncarrier male subjects.

Growth hormone therapy and tumor recurrence. Findings in children with brain neoplasms and hypopituitarism

We report the outcome of growth hormone (GH) therapy in 34 children (17 boys and 17 girls) with brain tumors in whom hypopituitarism developed. The types of tumors included the following: craniopharyngiomas (18); germinomas (four); astrocytomas (three); chromophobe adenomas (three); medulloblastomas (two); glioma (one); dermoid (one); retinoblastoma (one); and metastatic rhabdomyosarcoma from the pelvis (one). Ninety-four percent of the patients were GH deficient post-tumor therapy, which consisted of surgery with and without radiotherapy. Twenty-four of 34 patients received GH. Eight of 24 patients receiving GH had recurrence of tumor; 16 were tumor free eight to 72 months after initial therapy. Eleven patients had 12 recurrences. Patients with tumor recurrence had a considerably lower growth rate during the first year of GH therapy than those without recurrence (mean, 3.5 +/- 1.3 cm/yr v 6.2 +/- 2.5 cm/yr). Three of 11 patients with recurrence had not received GH therapy; however, one was receiving testosterone intramuscularly monthly at the time of a second recurrence. Thus, 24 of 34 patients with brain tumors and hypopituitarism received GH therapy. Eight (33%) of 24 had tumor recurrence, compared with three (30%) of ten who did not receive GH. The data suggest that GH therapy is probably not associated with increased rate of tumor recurrence.

Etiologic evaluation of male pseudohermaphroditism in infancy and childhood

We outlined a diagnostic scheme for use with prepubertal patients with male pseudohermaphroditism (MPH) that included karyotyping, a genitourethrogram, a human chorionic gonadotropin stimulation test with plasma hormone level determinations, and determination of 5 alpha-reductase activity and androgen receptor binding in genital skin fibroblasts. A thorough evaluation is warranted in all patients since the correct diagnosis may assist in determining gender assignment and providing appropriate genetic counseling. We studied 25 patients by the prescribed diagnostic scheme: seven of them had a partial gonadal dysgenesis, two were deficient in 5 alpha-reductase activity, two showed partial androgen insensitivity, four had multiple congenital malformations, one had a Wilms' tumor, and nine were considered as having an idiopathic form of MPH.

The voluntary food intake by growing pigs of diets containing 'treated' rapeseed meals or extracts of rapeseed meal

The intake by growing pigs of a diet containing British rapeseed meal (Brsm) extracted once with water was greater than that of a similar diet containing untreated Brsm, and a diet containing Brsm extracted twice with water was eaten more readily than one containing Brsm extracted once with water. Treatment of Brsm with slaked lime increased slightly its acceptability by growing pigs. The addition of a water extract of Brsm to a soya-bean meal (Sbm) diet reduced voluntary intake compared with the voluntary intake of the same Sbm diet with water added. Addition to the diet of a water extract passed through an anion exchange column increased food intake but if a cation exchange column was used there was no effect on intake. Treated rapeseed meals and extracts were analysed for glucosinolates, sinapine and tannins; the results indicated that glucosinolates rather than sinapine or tannin were associated with low feed intake.

Comparison of physiologic and pharmacologic assessment of growth hormone secretion

To determine if pharmacologic and physiologic tests are equally effective in the assessment of growth hormone (GH) secretory status, serum GH levels were measured during sequential tests with intravenous arginine infusion and insulin-induced hypoglycemia (arginine-insulin tolerance test [ AITT ] ) and during sleep in 62 children, aged 2.1 to 17.3 years. Responses during AITT and sleep were concordant in 53 patients and discordant in nine patients. Arginine-insulin tolerance test results were consistent with the subsequent clinical course in 80% of the patients while nocturnal sampling was consistent with the subsequent clinical course in 93% of the patients. Thus, the failure of a normal serum GH response to pharmacologic stimuli is not always a diagnostic indicator of GH deficiency. Additional investigation of discordant GH responses to pharmacologic and physiologic stimuli may lead to a further understanding of the control mechanisms of GH secretion.

Treatment of sexual precocity by removal of a luteinizing hormone-releasing hormone secreting hamartoma

A 1-year-old infant was initially seen with precocious puberty that progressed rapidly and was associated with episodic gonadotropin release. A computed tomographic metrizamide cisternogram showed a pedunculated mass below the tuber cinereum; the mass was resected. His pubertal development regressed, his accelerated growth ceased, and his hormone levels returned to the normal prepubertal range. Immunocytochemical studies of the tissue demonstrated luteinizing hormone-releasing hormone (LHRH) granules in the perikaryon of neurons and axons in the hamartoma and axons connecting the hamartoma to the tuber cinereum. These data suggest that such lesions cause pubertal development by stimulating gonadotropin secretion via episodic release of LHRH. If such lesions are pedunculated, operative resection may be the treatment of choice.

Localization, Interactions, and the Metal-Insulator Transition

Recent advances in our understanding of electronic conduction have pointed up deficiencies in traditional thinking. For a metal at a sufficiently low temperature, it is known both theoretically and experimentally that the conventional picture in terms of the Boltzmann theory breaks down. Improved understanding of both electron localization and the effects of electron-electron interactions in a disordered medium has led to experimentally verifiable predictions. These effects have an important influence on the nature of the metal-insulator transition.