JN, Lau SH: Time dependent changes in the functional properties of the atrioventricular conduction system in man. Circulation 52: 1012, 1975 10. Dhingra RC, Denes P, Wu D, Chuquimia R, Rosen KM: The significance of second degree atrioventricular block and bundle branch block. Observations regarding site and type of block. Circulation 49: 638, 1974 11. Dhingra RC, Denes P, Wu D, Chuquimia R, Ama...

BACKGROUND Type I antiarrhythmic drugs block the cardiac sodium channel in a use-dependent fashion. This use-dependent behavior causes increased drug binding and consequently increased sodium channel blockade at faster stimulation rates. Importantly, the kinetics of drug association and dissociation from the sodium channel differ for each type I antiarrhythmic drug. METHODS AND RESULTS Thirty...

After a frog tongue was adapted to 0.001 M quinine-HCl(Q-HCl), a change in the gustatory neural responses to salts was investigated. The initial phasic response to a variety of salt solutions such as 0.1 M NaCl, KCl, LiCl, MgCl2 and CaCl2 was greatly potentiated as a result of the Q-HCl adaptation. A weaker enhancement of the response to salts was observed after the tongue was adapted to deioni...

Infrared–ultraviolet double resonance has been used to photodissociate the free HCl bond of the HCl dimer. This creates Cl–HCl in a coherent superposition of electronic and vibrational states. Measurement of the translational energy of the departing H atom using high-n Rydberg time-of-flight spectroscopy enables the Cl–HCl potential surfaces to be probed. The features thus obtained agree with t...

The cycle length dependence of the action potential duration and the effective refractory period of the right ventricular endocardium were investigated in 24 patients undergoing electrophysiologic studies for suspected ventricular tachycardia. The action potential duration at 90% repolarization and the effective refractory period at twice diastolic threshold strength were measured at the same c...

1-Aminobenzotriazole (ABT) has been used widely as a nonselective in vitro and in vivo inhibitor of cytochrome P450 enzymes. To date, however, it has not been evaluated as an inhibitor of UDP-glucuronosyltransferase (UGT), sulfotransferase (SULT), and N-acetyltransferase (NAT). In the present study, ABT was shown not to inhibit UGT and SULT activity (acetaminophen and 7-hydroxycoumarin as subst...

The function of the enzyme butyrylcholinesterase (BChE) both in serum and in brain is unclear. In serum, BChE has been found complexed with several biomedically relevant proteins, with which it could function in concert. Here, the existence of a similar complex formed between BChE and sero-transferrin from adult chicken serum was elucidated. In order to identify both proteins unequivocally, we ...

AIMS To know the prevalence and the interaction among the principal cardiovascular risk factors such as hypercholesterolemia (HCL), hypertension (HTA), overweight, carbohydrates metabolism disturbances, and smoking, an urban survey was performed in the six Mexican Republic states, where the national population is more concentrated. METHODS This survey was transversally designed using the WHO ...

A patient with Wolff-Parkinson-White syndrome was disabled by rapid ventricular rates during atrial arrhythmia and by periods of asystole. Circus tachycardia was induced by atrial stimulation only after the administration of procainamide. Nevertheless, treatment with this drug controlled the ventricular rate and spontaneous circus tachycardia did not occur.