Do men with normal testosterone–oestradiol ratios benefit from letrozole for the treatment of male infertility?

Research question

Previous studies of aromatase inhibitors on male infertility have focused on men with low testosterone–oestradiol ratio of less than 10. Can aromatase inhibitors improve spermatogenesis in men with idiopathic male infertility with normal testosterone–oestradiol ratio?

Estimating the prevalence of problem gambling among older adults in Singapore

This study examined the prevalence rates of problem gambling among older adults in Singapore. A stratified sampling method was used to select the nationally representative sample of 3010 older adults aged 55 years and above. The survey participants were of varying ethnicities living in the community, including Chinese, Malay, and Indian (and others). A structured questionnaire, including the Canadian Problem Gambling Index, gambling attitudes and behaviors, and demographic information was administered face-to-face at participants' homes, using one of the four language versions preferred by the participants. Among those who had gambled lifetime, 69.7% (or weighted population = 39.2%) gambled in the past 12 months and 2.2% (or weighted population = .9%) met the problem gambling criteria. Individuals with problem gambling were likely to have started gambling at an younger age and to have gambled in activities characterized by continuity and no set money limits. Future research should examine changes in gambling behaviors of older adults over time in non-Western societies.     

Suppressive effect of acetylcholine on automaticity of cannine atrioventricular node

The effects of acetylcholine on the spontaneous activity of the AV node of dog hearts were studied by recording transmembrane potentials of its fibers. Action potentials of most nodal fibers were characterized by prominent phase 4 depolarization and a smooth transition from phases 4 to 0. On the isolated AV nodes, acetylcholine at 1.0 μg/m1 suppressed the rate of phase 4 depolarization and increased the amplitude of the maximum diastolic potential, resulting in a slowing of spontaneous activity. At 2.0 μg/m1, spontaneous activity was completely suppressed. In comparison, spontaneous activity of the isolated His bundle was relatively insensitive to the suppressive effect of acetylcholine at the same concentrations. In the AV node-His bundle preparations in which the AV node was the pacemaker, acetylcholine decreased spontaneous activity by suppressing the phase 4 depolarization of the nodal fibers and shifted the pacemaker of the preparation to the His bundle. The findings provide a basis for predicting that under strong vagal influence, the automaticity of the AV node will be suppressed and the pacemaker of the junctional rhythm will be located at the His bundle.