Protective effects of Mentha piperita Linn on benzo[a]pyrene-induced lung carcinogenicity and mutagenicity in Swiss albino mice

The Editor-in-Chief has retracted the published paper "ProtectiveEffects of     

Korotkoff sounds: development of the sphygmomanometry research at the Nursing School of the USP

This article pays homage to Sergei Nicolai Korotkoff, for the centenary of the auscultatory method discovery. It refers to his discover of blood pressure auscultatory method in Russia, in 1905; presents the evidence that resulted in the development of sphygmomanometry studies in Brasil; describes the important contribution of the Nursing School of the University of S?o Paulo to the development of blood pressure measurement research; and analyses the results of the research field of "Cuff width influence in blood pressure measurement", created at the Nursing School of The University of S?o Paulo, in 1974. The scientific results of doctoral studies are presented, identifying the research groups that are contributing to defying knowledge in this area. The article demonstrates the consolidation of the results related to the initial doctoral program studies developed in the area. Confirmation of hypothesis in longitudinal studies is emphasized.     

Temperature Control of Hypertensive Rats during Moderate Exercise in Warm Environment

The control of body temperature in Spontaneously Hypertensive Rat (SHR) subjected to exercise in warm environment was investigated. Male SHR and Wistar rats were submitted to moderate exercise in temperate (25°C) and warm (32°C) environments while body and tail skin temperatures, as well as oxygen consumption, were registered. Total time of exercise, workload performed, mechanical efficiency and heat storage were determined. SHR had increased heat production and body temperature at the end of exercise, reduced mechanical efficiency and increased heat storage (p < 0.05). Furthermore, these rats also showed a more intense and faster increase in body temperature during moderate exercise in the warm environment (p < 0.05). The lower mechanical efficiency seen in SHR was closely correlated with their higher body temperature at the point of fatigue in warm environment (p < 0.05). Our results indicate that SHR exhibit significant differences in body temperature control during moderate exercise in warm environment characterized by increased heat production and heat storage during moderate exercise in warm environment. The combination of these responses result in aggravated hyperthermia linked with lower mechanical efficiency.

Key Points

• The practice of physical exercise in warm environment has gained importance in recent decades mainly because of the progressive increases in environmental temperature;
• To the best of our knowledge, these is the first study to analyze body temperature control of SHR during moderate exercise in warm environment;
• SHR showed increased heat production and heat storage that resulted in higher body temperature at the end of exercise;
• SHR showed reduced mechanical efficiency;
• These results demonstrate that when exercising in a warm environment the hypertensive rat exhibit differences in temperature control.

Key words: Thermoregulation, physical exercise, hypertension, heat stress, exercise performance     

Clinical usefulness of electrophysiologic testing in patients with ventricular tachycardia and chronic chagasic cardiomyopathy treated with amiodarone or sotalol

INTRODUCTION: This study assessed the role of electrophysiologic testing to identify therapeutic strategies for the treatment of patients with sustained ventricular tachycardia (VT) and chronic chagasic cardiomyopathy treated with amiodarone or sotalol. METHODS AND RESULTS: One hundred fifteen patients [69 men (60%); mean age 52 +/- 10 years] with chagasic cardiomyopathy presenting with symptomatic VT were studied after loading with Class III antiarrhythmic drugs; 78 had a history of sustained VT, and 37 with symptomatic nonsustained VT had sustained VT induced at baseline electrophysiologic study. All but 12 patients also underwent baseline electrophysiologic study. Mean left ventricular ejection fraction was 0.49 +/- 0.14. Based on results of electrophysiologic study after loading with Class III drugs, patients were divided into three groups: group 1 (n = 23) had no sustained VT induced; group 2 (n = 45) had only tolerated sustained VT induced; and group 3 (n = 47) had hemodynamically unstable sustained VT induced. After a mean follow-up of 52 +/- 32 months, total mortality rate was 39.1%; it was significantly higher in group 3 than in groups 2 and 1 [69%, 22.2%, and 26%, respectively, P < 0.0001, hazard ratio (HR) 10.4, 95% confidence interval (CI) 3.8, 21.8]. There was no significant difference in total mortality rate between groups 1 and 2 (P = 0.40, HR 1.5, 95% CI 0.75, 4.58). Cardiac mortality and sudden cardiac death rates also were higher in group 3 patients. CONCLUSION: In patients with chagasic cardiomyopathy and sustained VT, electrophysiologic testing can predict long-term efficacy of Class III antiarrhythmic drugs. This may help in the selection of patients for implantable cardioverter defibrillator therapy.