RESUMEN
BACKGROUND: To ascertain the role of endogenous opioids in sexual response, naltrexone, an opiate receptor antagonist, was administered to men, and its effect on selected self-report measures of sexual response to masturbation was recorded. METHODS: The data are based on results from 20 healthy, sexually active (alone or with a partner) men, aged 20-29 years, who ingested naltrexone (25 mg/day x 3) or placebo in a randomized, double-blind crossover design. There was at least a 14-day interval between drug and placebo treatment. Between 18 and 22 h after the most recent dose of drug or placebo, subjects viewed sexually explicit videos in privacy for 2 h. They were instructed to masturbate and have as many orgasms as desired. The following three different self-report measures of their responses were recorded: number of orgasms; intensity of sexual arousal, and orgasmic intensity. RESULTS: Under the naltrexone condition, the volunteers experienced a significantly greater mean number of orgasms (3.4 +/- 0.2 SEM) than under the placebo condition (2.6 +/- 0.3). The total number of orgasms was 67 under the naltrexone condition and 51 under the placebo condition. At the first orgasm, the measure of intensity of arousal was significantly greater in the naltrexone (3.9 +/- 0.2) than placebo (3.4 +/- 0.2) condition, and the measure of orgasmic intensity was significantly greater in the naltrexone (3.7 +/- 0.2) than in the placebo (3.0 +/- 0.3) condition. CONCLUSIONS: The present study provides evidence that endogenous opioids modulate orgasmic response and the perceived intensity of sexual arousal and orgasm in men. The findings suggest that naltrexone could be clinically useful in cases of inhibited sexual desire and erectile dysfunction.
Asunto(s)
Naltrexona/farmacología , Antagonistas de Narcóticos/farmacología , Orgasmo/efectos de los fármacos , Adulto , Estudios Cruzados , Método Doble Ciego , Humanos , MasculinoRESUMEN
Lambda-cyhalothrin 10% WP (ICON 10WP) was sprayed from 5th November 1997 at a dose of 25 mg/m2 as indoor residual spray in 74 high risk villages. The spray was completed within 10 days in most of the villages. The monthly entomological monitoring showed nil density of Anopheles culicifacies and Aedes and very low density of non-vector Anopheles and Culex. The impact of Lambda-cyhalothrin spray was discernible right in the month of November 1997 showing 52% reduction in P. falciparum cases as compared to the same month of preceding year. The reduction of P. falciparum cases in three months post-spray period was 77% (from 47 cases to 11 cases) as compared to similar months of preceding year and overall reduction of total malaria cases was 50% during the same period. Since the major part of transmission of P. vivax infection was over by the time Lambda-cyhalothrin spray was taken up, obviously the impact on P. vivax infection was not markedly high as compared to P. falciparum infection. Neither cerebral malaria cases nor deaths due to malaria were recorded in the sprayed villages.
Asunto(s)
Vectores Artrópodos , Culicidae , Insecticidas , Malaria Falciparum/epidemiología , Animales , Humanos , Incidencia , India/epidemiología , Malaria Falciparum/prevención & control , Nitrilos , Densidad de Población , Piretrinas , Población Rural , Estaciones del AñoRESUMEN
The binding of 43 and 216 micrograms/ml sodium salicylate by a perfluorochemical emulsion, by human albumin, and by their mixtures, has been examined at ambient room temperature. Sodium salicylate was chosen as a model drug since it is bound by both sites I and II on human albumin. The concentration of free salicylate was determined through standard centrifugation followed by supernatant ultrafiltration. Sodium salicylate was weakly bound by the perfluorochemical emulsion droplets through an interaction with the emulsifiers. This binding was independent of salicylate concentration. Sodium salicylate was also bound by human albumin and the per cent free salicylate was dependent on both drug and albumin concentration. Relative to salicylate binding by 4% human albumin, addition of the emulsion to 4% human albumin resulted in an increase in the per cent free salicylate in all mixtures examined. The addition of equal or greater volumes of the emulsion to 4% human albumin resulted in the direct and/or indirect displacement of albumin bound salicylate in addition to the protein dilution effect. This displacement of albumin bound salicylate was due to the oleic acid component of the emulsion.
Asunto(s)
Salicilatos/sangre , Albúmina Sérica/metabolismo , Centrifugación , Emulsiones , Fluorocarburos/química , Humanos , Ligandos , Unión Proteica , Salicilatos/química , Ácido Salicílico , UltrafiltraciónRESUMEN
The effect of a perfluorochemical emulsion on ligand binding by human albumin was studied using a site specific approach. L-tryptophan was used as a marker for binding to site II on human albumin. Centrifugation, followed by supernatant ultrafiltration at ambient room temperature, was employed to determine the per cent tryptophan free. The partitioning of tryptophan from pH 7.4 phosphate buffer into the pure perfluorochemical liquids was insignificant. Tryptophan was not significantly bound by the perfluorochemical emulsion droplets. Binding of tryptophan by buffer dilutions of human albumin demonstrated that, at the tryptophan concentrations examined, human albumin concentration had little effect on the per cent tryptophan free. Tryptophan binding by mixtures of the perfluorochemical emulsion and human albumin showed that, at sufficiently high concentrations of the perfluorochemical emulsion, one or more of the emulsion components is responsible for the direct and/or indirect displacement of human albumin-bound tryptophan. The individual perfluorochemical emulsion components were studied for their effects on the binding of tryptophan by human albumin. Results showed that oleic acid and, to a very small degree, Pluronic F-68, were responsible for the displacement of human albumin-bound tryptophan.