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To evaluate the effects of pulsatile reperfusion on the post ischemic myocardium, two categories of sheep were put on cardiopulmonary bypass (CPB). In Category I, the hearts of 23 sheep were arrested by global ischemia for 30 min, reperfused with pulsatile flow in 10 animals (P group), and non pulsatile flow in 13 animals (NP group), and then defibrillated. The incidence of ventricular fibrillation was much higher in the NP group than the P group, 77% versus 40% (p < 0.05). The lipoperoxide products and creatinine kinase from coronary sinus blood were elevated, but there were no significant differences between the two groups during 2 hour reperfusion. In the P group, less ultrastructural damage was observed, and Na+ and H2O accumulations in the subendomyocardium were significantly less than in the NP group, at 7.11 +/- 0.60 versus 9.98 +/- 1.10 mg/g dry weight (p < 0.05) and 82.58 +/- 0.47% versus 84.3 +/- 0.38% (p < 0.05), respectively. In Category II, the ischemic time of 17 sheep (eight in the P group, nine in the NP group) was prolonged to 45 min, and animals were supported by CPB after defibrillation. Myocardial energy phosphates were measured with high-performance liquid chromatography, and triphenyltetrazolium chloride was used to delineate the infarct size. After 2 hour of reperfusion, there were no significant differences in myocardial AMP and ADP between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

The ionization degree and equation of state of dense xenon plasma were calculated by using self-consistent fluid variational theory for temperature of 4-30kK and density of 0.01-8.5gcm;{3} . The dense fluid xenon will be ionized at high pressures and temperatures. The ionization energy of xenon will be lowered due to the interactions among all particles of Xe, Xe+ , Xe2+ , and e . The ionization degree is obtained from nonideal ionization equilibrium, taking into account the correlative contributions to the chemical potential which is determined self-consistently by the free energy function. The composition of xenon has been calculated with given densities and temperatures in the region of partial ionization. The calculated results show a pressure softening regime at the onset of ionization. Comparison is performed with available shock-wave experiments and other theoretical calculations.