Intraventricular administration of antivasopressin serum inhibits retention in mice.

Elevations and decrements in the levels of the posterior pituitary hormone vasopressin result in facilitations and deficits in retention, respectively, in rats. Despite the frequent use of mice in studies of pharmacological influences on retention, there is a paucity of information regarding the role of endogenous peptides, particularly vasopressin, in the memory processes of mice. In the present experiment, mice suffering from acute inactivation of central vasopressin, induced by an immediately posttraining, 2 microliters, intracerebroventricular injection of antivasopressin serum, displayed a retention deficit for passive avoidance training. The results of this experiment suggest that endogenous vasopressin modulates the memory processes of mice, as well as rats.

Wide-complex tachycardia: continued evaluation of diagnostic criteria.

OBJECTIVE: To evaluate the accuracy of the Brugada algorithm for analysis of wide-complex tachycardia (WCT) when applied by board-certified emergency physicians and board-certified cardiologists. METHODS: A database consisting of 157 electrocardiograms of WCTs were evaluated in a blinded fashion using the Brugada criteria to determine the presence of ventricular tachycardia (VT) or supraventricular tachycardia with aberrancy. These results were then compared with the electrophysiologically proven diagnosis for each tracing. Sensitivity and specificity of the Brugada criteria for diagnosis of VT were calculated. Two board-certified emergency physicians and two board-certified cardiologists analyzed each tracing, and interobserver agreement was determined using the kappa statistic. RESULTS: Sensitivity and specificity for the determination of VT using the Brugada algorithm were 85% [95% confidence interval (95% CI) = 79% to 91%] and 60% (95% CI = 43% to 78%) for cardiologist 1 (C 1) and 91% (95% CI = 86% to 96%) and 55% (95% CI = 37% to 72%) for C 2. Emergency physician (EP 1) achieved a sensitivity of 83% (95% CI = 78% to 91%) and a specificity of 43% (95% CI = 25% to 59%), while EP 2 attained 79% (95% CI = 73% to 87%) and 70% (95% CI = 51% to 84%), respectively. The original authors achieved a sensitivity of 98.7% and specificity of 96.5% when determining VT in their study population. Interobserver agreement for the emergency physicians and the cardiologists in determining VT was 82% and 81%, respectively. CONCLUSIONS: Neither the emergency physicians nor the cardiologists were able to achieve a sensitivity or specificity as high as that reported by the original investigators when using the Brugada algorithm to determine the presence of VT.