tilt aftereffect is an illusion apparent following adaptation to stimuli angled 5 50 from vertical and thought to be affected by lateral inhibition between occipital neurons. A recent study identified an enhanced tilt aftereffect among ecstasy users, but only in a subset that were recently abstinent from amphetamines. The current study examined the effects of ecstasy use, cannabis use and their interacting effect on the magnitude of the tilt aftereffect among Selleckchem PF299 participants with no recent history of amphetamine consumption. Materials and Methods: Eleven ecstasy users, 15 cannabis users, 15 ecstasy plus cannabis users and 15 drug-naive controls were compared on the magnitude of the tilt aftereffect elicited following adaptation to stimuli angled 15, 30, 40 or 60 degrees from vertical. Results: At a 40 degrees adaptation condition, ecstasy users had a greater magnitude of the tilt aftereffect compared to those that had not taken the drug. Additionally, the extent of ecstasy use was positively associated with the magnitude of the tilt aftereffect generated following 15, 30 and 40 degrees adaptation conditions, but not at 60 degrees. Conclusions: Given that lateral inhibition mediates the tilt aftereffect following adaptation to GSK3326595 5-50 degrees, the findings of a relationship between ecstasy use and tilt magnitude at the 15-40 degrees
but not 60 degrees adaptation conditions support a role for serotonin in visual orientation
processing via lateral inhibition. Copyright (C) 2009 S. Karger AG, Basel”
“Objective: Reoperation rates to correct left atrioventricular valve regurgitation after primary Clomifene repair of atrioventricular canal defects remain relatively high. The causes of valvular regurgitation are likely multifactorial, and simple cleft closure is often insufficient to prevent recurrence.
Methods: To elucidate the mechanisms leading to regurgitation, we conducted hemodynamic studies using isolated native mitral valves. Anatomy of these valves was altered to mimic atrioventricular canal type valves and studied under pediatric hemodynamic conditions. The impact of subvalvular geometry, cleft closure, annular dilatation, and annular undersizing on regurgitation were investigated.
Results: Papillary muscle position did not have a significant effect on regurgitation. Cleft closure had a significant impact on valvular competence, with reduction in regurgitation volume with increased cleft closure. Regurgitation volume decreased from 12.5 +/- 2.4 mL/beat for an open cleft to 4.9 +/- 1.9 mL/beat for a partially closed cleft and to 1.4 +/- 1.6 mL/beat when the cleft was completely closed. Annular dilatation had a significant impact on regurgitation even after cleft closure. A 40% increase in annular size increased regurgitation by 59% for a partially closed cleft and by 84% for a fully closed cleft.