A detailed examination of the in vivo and in vitro effects of ACTH on gonadotropin secretion in the adult rat

These studies were designed to: (1) determine the effects of continuous infusion of synthetic ACTH(1-24) on postcastration changes in serum and pituitary LH, FSH and prolactin in the male rat; (2) assess the effects of adrenalectomy on the gonadotropin and prolactin response to ACTH, and (3) test the hypothesis that ACTH may directly (not via adrenal factors) alter gonadotropin secretion at the brain and/or pituitary level. Adult male rats were either orchidectomized (ORX) or orchidectomized-adrenalectomized (ORX-ADX), and were treated continuously for 6 days with ACTH(1-24) (10 micrograms/day) or saline using an osmotic minipump. Animals were killed on day 6 following castration. ACTH treatment reduced serum LH and prolactin levels in ORX rats to mean values +/- SE of 204 +/- 25 and 37 +/- 3 ng/ml respectively, compared to 366 +/- 72 and 62 +/- 7 ng/ml in saline-treated ORX animals. Serum FSH concentrations were not altered by ACTH administration. Pituitary concentrations of LH and FSH, but not prolactin were enhanced by ACTH treatment. Adrenalectomy had no effect on serum and pituitary gonadotropin and prolactin levels, but abolished the effects of ACTH on these parameters. Central (intracerebroventricular) infusion of ACTH(1-24) (6 micrograms/day X 4 days) failed to alter the rise in serum LH in male rats following orchidectomy. Acute treatment with large doses of ACTH of perifused anterior pituitary glands from male rats and chronic treatment with ACTH of enzymatically dispersed anterior pituitary cells from female rats did not influence basal or GnRH-stimulated LH secretion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of the silymarin content in Silybum marianum (L.) Gaertn. Cultivated under different agricultural conditions

An HPLC assay for the determination of silymarin in the fruits of Silybum marianum is given. The effect of different water regimes and nitrogen fertilization levels on the silymarin content of cultivated plants grown in reclaimed desert land have been studied. The highest silymarin contents were obtained upon nitrogen fertilization with 100, 150 kg/feddan (1 feddan = 4200 m²) and a 60% water regime without fertilization compared to the content of silymarin in wild plants.     

Mixed gangliocytoma-adenoma: a distinct neuroendocrine tumor of the pituitary fossa

A mixed gangliocytoma-adenoma occurring in the pituitary fossa of a patient who presented with acromegaly, galactorrhea, and headaches is described. Immunohistochemical studies demonstrated the gangliocytic portion of the tumor to be composed nearly entirely of ganglion cells enmeshed in their neuritic processes and disclosed focal presence of growth hormone and prolactin-secreting cells in the adenoma. Ultrastructurally, some of the larger ganglion cells contained (and were often filled with) zebra-like bodies, while the adenoma was shown to be sparsely granulated with numerous fibrous bodies. These findings support the term of mixed gangliocytoma-adenoma for these rare intrasellar tumors and provide additional support for their nature as independent neuroendocrine units.     

Inhibition of superoxide anion release from human polymorphonuclear leukocytes by N-acetyl-galactosamine and N-acetyl-glucosamine

Summary This study shows that N-acetyl-galactosamine and N-acetyl-glucosamine and diminish the production of superoxide anion from cytochalasin-B treated PMNs stimulated with FMLP. Inhibition ranged from 80.9% to 1.8%. N-acetyl-galactosamine was superior to N-acetyl-glucosamine, but both showed their action in a dose — related fashion. The mannosamine may diminish the superoxide production, but without a statistical significance. Other sugars such as L-fucose, D-fucose and D-glucose failed to induce inhibition of superoxide generation. Previous reports showed that sugars interfere with carbohydrates lectins interaction. This study shows that aminosugars can do more than interfere with carbohydrates-lectin interaction. The mechanism is not completely known yet. The question whether aminosugars affect cell-cell interaction, regulation of respiratory burst, inflammatory mediators functions, or the glucose uptake and utilization needs further study.     

Direct oral questions to blood donors: the impact on screening for human immunodeficiency virus

BACKGROUND: In December 1990, the Food and Drug Administration recommended that all United States blood centers implement a policy of asking prospective donors direct oral questions (DOQs) about human immunodeficiency virus (HIV) risk behaviors to increase the safety of the blood supply. STUDY DESIGN AND METHODS: To evaluate the impact of the DOQ policy, HIV-related deferral and HIV seroprevalence data were analyzed at four American Red Cross blood centers for the year before the policy change and the year after. An epidemiologic analysis with stratification was conducted, including the calculation of odds ratios (OR) and 95-percent CIs. RESULTS: Two of the four blood centers showed an overall significant increase in HIV-related deferral after implementation of the DOQ policy: OR = 4.04, (95% CI = 3.41, 4.76); OR = 2.93, (95% CI = 2.67, 3.21). The increase in HIV-related deferral was higher for women. HIV seroprevalence decreased at all four centers, including the two that did not see an increase in HIV-related deferrals. Seroprevalence declined by 14 percent in the two centers with increases in HIV-related deferral, which was neither significant nor attributable to DOQs. CONCLUSION: Given that HIV antibody screening cannot detect HIV-seronegative (but infectious) "window-period" donations, the deferral of at-risk donors may offer some additional protection to the blood supply. However, evidence was not found of an increase in safety of the blood supply as measured by HIV seroprevalence.