Macular degeneration: a possible biochemical mechanism

The possible role of labile endogenous metabolites in the cause of various chronic debilitating diseases such as macular degeneration has not been adequately explored. In the metabolism of the various retinoids, namely retinal (vitamin A aldehyde), retinol (vitamin A alcohol) and retinoic acid, each has the potential for generating labile intermediates, such as their corresponding 5,6-epoxides by the action of various cytochrome P(450)s. Such retinoid epoxides may well have the capacity for acting as toxins upon the neurons in the macula unless they are rapidly hydrolyzed by epoxide hydrolases. Since the cytochrome P(450)s responsible for epoxide formation and the various epoxide hydrolases involved in their hydrolysis are determined genetically, this may serve to explain a genetic component being involved in the causation of age-related macular degeneration.     

Hemospermia following transrectal ultrasound-guided prostate biopsy: a prospective study

Hemospermia is known to be associated with transrectal ultrasound-guided prostate biopsy (TRUS-PB). The true incidence of hemospermia, its duration and implications are not well established. We performed a prospective observational study involving patients undergoing TRUS-PB for suspected prostate cancer at our institution. Sixty-three eligible men were included in the study. Most men (84%) undergoing TRUS-PB, who were able to ejaculate, experienced hemospermia, which was associated with some degree of anxiety. The mean duration of hemospermia was 3.5 (+/-1.7) weeks. The number of ejaculations before the complete resolution of hemospermia was 8 (+/-6.7). None of the clinical and pathological factors was a significant predictor of the duration of hemospermia. Patients should be adequately counseled before TRUS-PB to avoid undue anxiety and alterations in sexual activity.