Sites in the male primate brain at which testosterone acts as an androgen

Quantitative autoradiographic analysis was used to identify regions in the brain of the male primate where androgen binding sites may be involved in the actions of testosterone. Three days after castration, adult male rhesus monkeys received a subcutaneous injection of either dihydrotestosterone propionate (DHTP, 20 mg, n = 6), testosterone propionate (TP, 100 mg, n = 2), or oil vehicle (control males, n = 4). Three hours later, 5 mCi [3H]testosterone was administered as an i.v. bolus. At 60 min, brains were rapidly removed and the left halves were used for autoradiography. In control males, highest percentages of labeled neurons (20-84% using a rigorous Poisson criterion) were observed in the ventromedial, arcuate and premammillary nuclei (n.) of the hypothalamus, medial preoptic n., bed n. of stria terminalis, intercalated mammillary n., lateral septal n. and the medial, cortical and accessory basal n. of the amygdala. Pretreatment with DHTP eliminated labeling in androgen target tissues of the genital tract, and reduced the percentages of labeled neurons to 4-22% of control values in the arcuate, lateral septal, premammillary and intercalated mammillary n., indicating that in these regions testosterone acted predominantly at androgen binding sites. However, in the medial preoptic n., the ventromedial hypothalamic n. and the accessory basal amygdaloid n., DHTP pretreatment resulted in much less blocking which, together with other data, suggested that in these sites, testosterone's actions involved aromatization and interaction with estrogen-binding sites.     

Fluoridated elastomers: effect on the microbiology of plaque.

The objective of this study was to investigate the effect of fluoridated elastomeric ligatures on the microbiology of local dental plaque in vivo. This randomized, prospective, longitudinal, clinical trial had a split-mouth crossover design. The subjects were 30 patients at the beginning of their treatment with fixed orthodontic appliances in the orthodontic departments of the Liverpool and the Sheffield dental hospitals in the United Kingdom. The study consisted of 2 experimental periods of 6 weeks with a washout period between. Fluoridated elastomers were randomly allocated at the first visit to be placed around brackets on tooth numbers 12, 11, 33 or 22, 21, 43. Nonfluoridated elastomers were placed on the contralateral teeth. Standard nonantibacterial fluoridated toothpaste and mouthwash were supplied. After 6 weeks (visit 2), the elastomers were removed, placed in transport media, and plated on agar within 2 hours. Nonfluoridated elastomers were placed on all brackets for 1 visit to allow for a washout period. At visit 3, fluoridated elastomers were placed on the teeth contralateral to those that received them at visit 1. At visit 4, the procedures at visit 2 were repeated. Samples were collected on visits 2 and 4. A logistic regression was performed, with the presence or absence of streptococcal or anaerobic growth as the dependent variable. A mixed-effects analysis of variance was carried out with the percentage of streptococcal or anaerobic bacterial count as the dependent variable. The only significant independent variables were the subject variable (P =<.001) for the percentage of streptococcal and anaerobic bacterial count and the visit variable for the percentage of streptococcal count (P =<.001). The use of fluoridated or nonfluoridated elastomers was not significant for percentage of either streptococcal (P =.288) or anaerobic count (P =.230). Fluoridated elastomers are not effective at reducing local streptococcal or anaerobic bacterial growth after a clinically relevant time in the mouth.     

Camp Okizu: Preliminary Investigation of a Psychological Intervention for Siblings of Pediatric Cancer Patients

This research was conducted at a summer camp for siblings of children with cancer. The camp is designed to address emotional problems, provide peer interaction and validation, and bolster siblings' self-esteem. Standardized measures assessing posttraumatic stress, anxiety, quality of life, and self-esteem were administered to 77 siblings (ages 6-17) prior to attending camp and again 3 months after camp. From pre- to post-camp, the siblings reported statistically significant decreases in symptoms of posttraumatic stress and anxiety, and statistically significant improvements in quality of life and self-esteem. These preliminary findings are encouraging and suggest the value of camp as a psychological intervention and provide a model for other pediatric cancer facilities designing intervention programs for siblings.