Biomedical subjects

R S Reneman

Publications and source records attributed to R S Reneman.

363 records · Page 21Linked to original sources

PubMedDate not supplied

Influence of therapeutic doses of amoxicillin on aerobic work capacity and some strength characteristics.

The purpose of this study was to investigate whether or not amoxicillin in therapeutic doses could have an influence on maximal aerobic work capacity and some strength characteristics in trained subjects. Fifteen volunteers (men; age range, 21 to 38 years; mean, 28.8 years) were examined once weekly for 4 consecutive weeks, and on these occasions the following variables and parameters were measured: maximum workload attained on the bicycle ergometer, maximum heart rate, maximum serum lactate concentration, heart rate and serum lactate concentration after 10 min at 80% of the maximum workload attained, maximum isometric extension force of the legs, vertical jump height, and body weight. During the baseline period, the determined variables and parameters did not show any significant difference between Test 1 and Test 2. During the 3rd and 4th week of the test period, the subjects received at random either placebo (6-aminopenicillanic acid) or amoxicillin in therapeutic doses (375 mg, 3 times a day) every day for 5 days. After the third test in the 3rd week, there was a cross-over, ensuring that each volunteer was examined during placebo as well as during amoxicillin medication. The serum amoxicillin levels were determined. After statistical analysis, no influence of amoxicillin or placebo on the parameters and physiologic variables was demonstrable.

Adult↗

PubMedDate not supplied

Cardiac and hemodynamic effects of intravenous R 80122, a new phosphodiesterase III inhibitor, in anesthetized and awake dogs.

R 80122 is a newly synthesized, selective phosphodiesterase III inhibitor. The cardiac and hemodynamic effects of this compound following intravenous administration were studied in closed-chest anesthetized as well as in conscious chronically instrumented dogs. The findings in the closed-chest anesthetized dogs indicate that R 80122 has positive inotropic and possibly moderate vasodilating properties [maximum increase in LV dp/dtmax/pd: 61%, and maximum decrease in systemic vascular resistance: 29% (a 12.5% decrease for the solvent)]. As a result, cardiac output maximally increased to 149% of the control value. The most striking effect of R 80122 was its positive lusitropic effect (maximal decrease in the time constant of relaxation [T] of 46%). This pronounced lusitropic effect of R 80122 can be regarded as beneficial, because of the increasing evidence that lusitropic defects play an important role in disorders related to heart failure. These effects of R 80122 were associated with only slight changes in arterial blood pressure. The effects of R 80122 lasted about 75 min after stopping the infusion. No ventricular arrhythmias were noted during and after infusion of the compound. The positive inotropic effects seen in anesthetized dogs were confirmed in conscious nonsedated dogs. It may be concluded that R 80122 has a clinically favorable cardiovascular profile for acute applications in heart failure, because its combined positive inotropic and positive lusitropic effects, and moderate vasodilating properties lead to a pronounced increase in cardiac output and only minimal changes in aortic blood pressure.

Anesthesia↗

PubMedDate not supplied

Ultrasonic imaging in the diagnosis of extracranial carotid artery disease.

Basically two principles have to be distinguished in ultrasonic imaging of arteries. In velocity imaging blood flow velocities are visualized with continuous wave or pulsed Doppler devices. In pulsed echo-systems artery wall structures are visualized by picking up echoes reflected by the vessel walls. Velocity imaging is mainly used to localize the site of velocity sampling which is of importance in screening the carotid artery bifurcation and in follow-up studies. Although promising results have been obtained in diagnosing atherosclerotic lesions with echo-imaging systems, these systems have their limitations. To improve the diagnostic accuracy these systems should be combined with a single- or multi-gate pulsed Doppler system.

Blood Flow Velocity↗