The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 

Assessment of left ventricular end-systolic pressure-volume relations with an impedance catheter and transient inferior vena cava occlusion: use of this system in the evaluation of the cardiotonic effects of dobutamine, milrinone, Posicor and epinephrine.

The end-systolic pressure-volume relation has been postulated as a load-independent measure of cardiac contractility, but has been difficult to measure because of technical problems associated with the serial measurement of intracardiac volume over a physiologic range of ventricular loading conditions. Utilizing a multielectrode impedance catheter to assess continuous, on-line left ventricular relative volume during transient inferior vena cava occlusion, a method is described for determining the end-systolic pressure-volume relation and for assessing changes in this relation secondary to inotropic modulation. In particular, using this method, the relative inotropic properties were determined of four drugs: dobutamine, milrinone, epinephrine and an experimental cardiotonic agent (Ro 13-6438, Posicor). Left ventricular micromanometer pressure and impedance catheter volume were measured continuously in 10 open chest, anesthetized dogs and 14 pigs. Arterial pressure was altered over a range of 20 to 60 mm Hg by brief inferior vena cava constriction. A linear end-systolic pressure-volume relation was observed in pressure-volume diagrams constructed from on-line pressure and impedance catheter recordings. Administration of dobutamine, milrinone and epinephrine resulted in a leftward shift and an increase in the slope of the end-systolic pressure-volume relation as compared with baseline; Posicor did not alter the slope over a range of doses, despite an increase in the cardiac output secondary to arterial vasodilation. Volume changes as measured by the impedance method closely paralleled simultaneous changes in the ultrasonic crystal-determined segment length, and the impedance end-systolic pressure-volume relation slope was reproducible with repeated load-altering maneuvers.(ABSTRACT TRUNCATED AT 250 WORDS)[1]

References

 
WikiGenes - Universities