Application of flow cytochemistry to the evaluation of HL-60 differentiation

The application of flow cytochemistry to the analysis of previously unreported differentiation-related functions, was investigated in HL-60 cells. After 72 and 96 h of continuous RA-exposure mean peroxidase index and percentage of large unstained cells were significantly less than in time-related control cultures. Percentage neutrophils were significantly increased in induction cultures. Although total cell number increased with time in both control and induction cultures, the increase was less in induction cultures. These findings are consistent with the differentiation-associated growth limitation and with the decreased myeloperoxidase activity reported in RA-treated cultures in other studies. We propose that in the context of RA-induced HL-60 maturation, flow cytochemistry could become a useful adjunct to conventional functional differentiation assessment.

Effect of various propofol plasma concentrations on regional myocardial contractility and left ventricular afterload

The cardiovascular effects of propofol infusions, designed to maintain constant plasma concentrations, were examined in an open-chested pig model. Regional myocardial contractility was measured with the end-systolic pressure-length relationship (Ees) and left ventricular afterload quantified by the effective arterial elastance (Ea). The propofol plasma concentrations in this study varied between 0 and 7.73 (SEM 0.96) micrograms/mL. A significant correlation for the increasing propofol plasma concentration and a decrease in myocardial contractility (P = 0.0056) was demonstrated, and the Ea remained constant. This gave rise to a reduction in stroke volume (P = 0.002) and, combined with a decrease in the heart rate (P = 0.0001), led to a reduction in the cardiac output (P = 0.0001). When the propofol infusion was stopped, myocardial contractility did not recover in parallel with the decrease in plasma propofol concentration.