Combination of bright light and caffeine as a countermeasure for impaired alertness and performance during extended sleep deprivation

Effects of four conditions (Dim Light-Placebo, Dim Light-Caffeine, Bright Light-Placebo and Bright Light-Caffeine) on alertness, and performance were studied during the night-time hours across 45.5 h of sleep deprivation. Caffeine (200 mg) was administered at 20.00 and 02.00 hours and bright-light exposure (>2000 lux) was from 20.00 to 08.00 hours each night. The three treatment conditions, compared to the Dim Light-Placebo condition, enhanced night-time performance. Further, the combined treatment of caffeine and all-night bright light (Bright Light-Caffeine) enhanced performance to a larger degree than either the Dim Light-Caffeine or the Bright Light-Placebo condition. Beneficial effects of the treatments on performance were largest during the early morning hours (e.g. after 02.00 hours) when performance in the Dim Light-Placebo group was at its worst. Notably, the Bright Light-Caffeine condition was able to overcome the circadian drop in performance for most tasks measured. Both caffeine conditions improved objective alertness on the Maintenance of Wakefulness Test. Taken together, the above results suggest that the combined treatment of bright light and caffeine provides an effective intervention for enhancing alertness and performance during sleep loss.     

Comparative effect of truncal vagotomy and pirenzepine on postprandial secretory response of exocrine pancreas in dogs

The comparative effect of truncal vagotomy and associated pyloroplasty and orally administrated pirenzepine (75 mg, 1 h before food intake) on the exocrine pancreatic secretory response to food was studied in conscious dogs. Both pirenzepine administration and truncal vagotomy totally abolished the pancreatic hydromineral and organic secretory response to food intake while postprandial pH of intraduodenal content remained above 6. From the results of our study we conclude that the vago nerve must not be altered in order to assure a pancreatic response to food intake and that pirenzepine is as strong as truncal vagotomy in maintaining pH in postprandial intraduodenal content over 6.     

Dominantly inherited posterior subcapsular cataract

We report on a family in which many family members show dominantly inherited posterior subcapsular cataract (PSC). While PSC is not a particularly uncommon finding, especially from the influence of congenital, systemic disease, ocular disease and toxic factors, reports of genetically determined PSC are comparatively few in the ophthalmic literature.     

A New Sock Electrode for Recording Epicardial Activation from the Human Heart: One Size Fits All

Simultaneous recording of epicardial activation from multiple sites during open heart surgery is essential for studying unstable ventricular arrhythmias. A previously described sock electrode array for this purpose requires custom-woven nylon sock material and expensive machined button electrodes. The limited compiiance and elasticity of nylon requires that a new sock be individually fitted for each heart. Despite careful fitting, 17–20% of electrodes do not make satisfactory epicardial contact in dogs. Further, electrodes frequently dislodge from the sock and wires break at the button electrode solder joint. Recognizing these limitations, we formed a new sock from Xspan* tubular dressing material and devised electrodes that attach securely to the sock. In six dogs. 90%± 3% of electrodes made satisfactory contact using the same Xspan* sock. significantly (p < .01) more than with the nylon sock despite far less labor. The same size X span* sock with 60 snap electrodes was used to record from 27 human hearts of widely different dimensions. Satisfactory epicardial contact was obtained in 90%± 14% of electrodes in the 18 patients with Wolff-Parkinson-White syndrome (WPW) and 75%± 15% of electrodes in the nine patients with coronary artery disease. In no case did an accessory pathway fail to conduct following sock placement. The hemodynamic effect of the Xspan* sock was evaluated in four dogs and was found to be minimal. Both the Xspan* sock and the snap electrodes are easily made from inexpensive, readily available materials. The same Xspan* sock accommodates o wide range of heart sizes, and the electrodes supported by the Xspan* sock record significantly better and with less dislodgement and wire breakage than previous socks.