Risperidone exerts potent anti-aggressive effects in a developmentally immature animal model of escalated aggression.

BACKGROUND: Risperidone has been shown to be clinically effective for the treatment of aggressive behavior in children, yet no information is available regarding whether risperidone exhibits aggression-specific suppression in preclinical studies that use validated developmentally immature animal models of escalated aggression. Previously, we have shown that exposure to low doses of the psychostimulant cocaine-hydrochloride (.5 mg/kg intraperitoneally) during the majority of pubertal development (postnatal days [P]27-57) generates animals that exhibit a high level of offensive aggression. This study examined whether risperidone exerts selective aggression-suppressing effects by using this pharmacologic animal model of highly escalated offensive aggression. METHODS: Experimental hamsters were tested for offensive aggression after the acute administration of risperidone (.05-1.0 mg/kg, intraperitoneally). RESULTS: Risperidone dose-dependently reduced the highly aggressive phenotype, with a significant reduction observed at .1-.2 mg/kg for most aggressive responses measured. Experimental animals treated with higher doses of risperidone (.3-1.0 mg/kg) showed significant reductions in aggression and social interest toward intruders, indicating more general behavioral inhibition. CONCLUSIONS: These studies provide evidence that risperidone exerts specific aggression-suppressing effects in a developmentally immature animal model of escalated aggression.     

Effects of HIV antibody test knowledge on subsequent sexual behaviors in a cohort of homosexually active men.

This study assesses the effects of HIV (human immunodeficiency virus) antibody testing on subsequent (one year) sexual behavior among 270 homosexual men at a Boston community health center, 21 per cent of whom were unaware of their test result. Except for the number of steady partners, the levels of all sexual activities of all groups of study participants declined over time. No effects of test awareness of antibody status were found on protective behavior for receptive anogenital contact. Elimination of unprotected insertive anogenital contact (by elimination of the practice or by condom use) was reported somewhat more often among seropositive men who became aware of their test result. Increased negative emotional reactions were reported by HIV seropositive men who were aware of their test result. These results suggest some behavioral impact of HIV antibody test knowledge in this cohort, but may not be generalizable to other populations.     

Treatment selection for carcinoma of the base of the tongue

Between 1974 and 1984, 173 patients were treated for squamous cell carcinoma of the tongue base. Fifty-four patients had T1 or T2 primaries, while 115 patients had T3 or T4 tumors (4 were not staged). Lymph node metastasis was present in 120 patients. Early primary tumors treated with surgery or radiotherapy had a control rate of 83% (5 of 6 tumors) and 89% (40 of 45 tumors), respectively. For advanced primary tumors, definitive radiotherapy produced a local control rate of 55% (42 of 76 tumors), compared with 79% (23 of 29 tumors) for surgery and postoperative radiotherapy. If primary control was obtained, the regional failure rate was less than 10%. Tumor growth patterns were predictive of the response to radiotherapy. The primary control rate at 2 years for 21 patients with exophytic tumors was 84% as opposed to 58% for 62 patients with ulcerative-infiltrative tumors (p = 0.04). Radiotherapy is effective for early stage or exophytic tumors, whereas for advanced or deeply invasive tumors combined therapy enhances local control.     

Comparison of the interaction of agmatine and crude methanolic extracts of bovine lung and brain with alpha 2-adrenoceptor binding sites.

1. In the present study we have evaluated whether alpha 2-adrenoceptor binding sites on bovine cerebral cortex membranes labelled by [3H]-clonidine, [3H]-idazoxan and [3H]-RX-821002 can distinguish between known agonists and antagonists. This model has then been used to compare the binding profiles of the putative non-catecholamine, clonidine-displacing substance (CDS), agmatine and crude methanolic extracts of bovine lung and brain. 2. Saturation studies carried out in the presence and absence of noradrenaline, 10 mumol 1(-1), revealed that the maximum number of binding sites on bovine cerebral cortex membranes for [3H]-idazoxan and [3H]-RX-821002 were approximately 60-80% greater than those for [3H]-clonidine (62.6 fmol mg-1 protein). Rauwolscine, the selective alpha 2-adrenoceptor antagonist, was approximately 100 fold more potent against each of the ligands than the selective alpha 1-adrenoceptor diastereoisomer, corynanthine. Also, the pKi value for the selective alpha 1-adrenoceptor prazosin against each ligand was less than 6. 3. Adrenaline, UK-14034, rauwolscine, corynanthine, RX-811059 and prazosin produced concentration-dependent inhibition of binding of all three 3H-ligands. The agonists, adrenaline and UK-14304, were approximately 5 and 10 fold less potent against [3H]-idazoxan and [3H]-RX-821002, respectively, than against [3H]-clonidine. In marked contrast, the antagonists, rauwolscine, corynanthine, RX-811059 and prazosin exhibited a different profile, being approximately 2-3 fold more potent against sites labelled by [3H]-RX-821002 and [3H]-idazoxan compared to sites labelled by [3H]-clonidine.(ABSTRACT TRUNCATED AT 250 WORDS)     

HIV疫苗

尽管经过了 2 0年的努力 ,对预防HIV/AIDS感染的疫苗开发仍然没有确切的结果。本文分析了开发HIV疫苗如此艰难的原因 ,提出了通过免疫学途径研究针对发达国家感染者的最佳候选疫苗 ,然后再将最有希望的疫苗引入发展中国家 ,以努力预防感染和发病的工作计划。