Tissue factor activity of endothelial cells incubated with A fumigatus. Time course of tissue factor activity of endothelial cells incubated for 4, 8, and 16 hours with viable and nonviable conidia or germ tubes of A fumigatus. Endothelial cells were also stimulated with LPS as a positive control (insert). Tissue factor activity was expressed as fold increase (stimulation index) relative to the basal level of activity of unstimulated cells. The results are means ± standard deviation of at least 3 independent experiments. Error bars indicate standard deviation. *P < .05 compared with control.