FIG. 4.

Effect of gram-negative and gram-positive sera on neutrophil apoptosis. Neutrophils isolated from healthy subjects were incubated in media containing either 10% HS (sera from healthy subjects, control), 10% gram-negative sera (sera from gram-negative infected patients), 10% gram-positive sera (sera from gram-positive infected patients), 10% culture-negative sera (sera from infected culture-negative patients), or 10% pooled sera (infected patients) for 6, 12, and 24 h. At the end of the incubation period, cells were stained with H-33342 and propidium iodide. Results (means ± SEM) are from three series of experiments, each carried out in triplicate. ∗, P < 0.001 compared with the respective control; ∗∗, P < 0.01 compared with the respective control; ∗∗∗, P < 0.001 compared with the respective control.