Testosterone substitution with a new transdermal, hydroalcoholic gel applied to scrotal or non-scrotal skin: a multicentre trial.

OBJECTIVE: Testosterone-containing gels have improved testosterone substitution therapy, but they are associated with the risk of interpersonal transfer. Therefore, we tested a new hydroalcoholic 2.5% testosterone gel (TGW), which was removed by washing 10 min after administration. DESIGN: The gel was applied to scrotal or non-scrotal skin in comparison to two 2.5 mg Androderm patches in a randomised, three-arm, parallel-group, controlled multicentre trial over a period of 24 weeks. We included symptomatic hypogonadal men whose morning testosterone levels were <10 nmol/l. Either 1 g TGW was applied to scrotal skin (n = 54) or 5 g to non-scrotal skin (n = 56) once daily; the patch group (n = 52) applied two patches/day. Dose titration was allowed. RESULTS: Whereas serum testosterone levels and the pre-post changes of the areas under the curve of testosterone and free testosterone between weeks 0 and 24 indicated equivalent treatment success for the patch and scrotal groups, the dermal gel group was significantly superior to the other two groups. Questionnaires on sexual function, mood and quality of life did not differ significantly between study groups, nor were prostate volume, prostate-specific antigen (PSA) levels and prostate symptoms different. However, tolerability was much better in the gel groups than the patch group. CONCLUSION: Efficacy, safety and tolerability suggest TGW as a favourable treatment for hypogonadal patients

A fast stimulus procedure to determine local receptive field properties of motion-sensitive visual interneurons

Krapp HG, Hengstenberg R. A fast stimulus procedure to determine local receptive field properties of motion-sensitive visual interneurons. Vision research. 1997;37(2):225-234.We present a method to determine, within a few seconds, the local preferred direction (LPD) and local motion sensitivity (LMS) in small patches of the receptive fields of wide-field motion-sensitive neurons. This allows us to map, even during intracellular recordings, the distribution of LPD and LMS over the huge receptive fields of neurons sensing self-motions of the animal. Comparisons of the response field of a given neuron with the optic flow fields caused by different movements in space, allows us to specify the particular motion of the animal sensed by that neuron