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Biomedical subjects

R Wadsworth

Publications and source records attributed to R Wadsworth.

At least 37 records · Page 2Linked to original sources
PubMed1996

The effect of four different surgical prone positions on cardiovascular parameters in healthy volunteers.

Twenty healthy volunteers were placed in four different surgical prone positions: on pillows, on an evacuatable mattress, on pelvic props and in the knee-chest position. The normal supine position was used as a control for the measurement of cardiovascular parameters. Mean arterial pressure was measured by automated oscillotonometry. Transthoracic electrical bioimpedance was used to measure cardiac output and heart rate. Cardiac index and total vascular resistance index were derived from these data. No significant changes in heart rate or mean arterial pressure occurred when the volunteers were moved from the supine position to any of the four prone positions or when returned to the supine position again. Cardiac index decreased significantly on going from the supine to the knee-chest position (20%) and onto the props (17%) but not onto the evacuatable mattress (11%) or the pillows (3%).

Adult↗
PubMed1995

Effects of diltiazem and its analogue siratiazem on contraction and 45Ca2+ uptake in sheep coronary artery rings.

1. Siratiazem, an analogue of diltiazem designed to be resistant to N-demethylation, was compared with diltiazem for inhibition of Ca(2+)-induced contraction of depolarized coronary artery rings from the sheep. There was no significant difference in potency between siratiazem and diltiazem in the presence of normal physiological salt solution (IC25 for siratiazem 0.13 +/- 0.04 microM and for diltiazem 0.08 +/- 0.02 microM) or one mimicking some of the conditions that occur during myocardial ischaemia (hypoxia, acidosis, reduced glucose and addition of lactate). 2. K(+)-stimulated 45Ca2+ uptake in coronary artery rings was also inhibited by siratiazem and diltiazem with similar potencies. 3. It is concluded that siratiazem inhibits Ca2+ entry in coronary vascular smooth muscle equipotently with diltiazem and that this effect is not modified by some of the changes that occur during myocardial ischaemia.

Animals↗