Analysis of MPs from HPAF-II and HPAC cells. (A) Nude mice were injected intravenously with 100 μL of HPAF-II MPs (1 ng of TF activity) or HPAC MPs (1 ng of TF activity), blood was collected immediately (n = 2) or after 2 minutes (n = 3), and human TF activity in isolated MPs was determined. (B) Nude mice were injected intravenously with 100 μL of PBS (n = 6), HPAF-II MPs (1 ng of TF activity, n = 6), or HPAC MPs (1 ng of TF activity, n = 6), and blood was collected 15 minutes later. Plasma TAT levels were measured and results are shown as dot plots with means ± SEM. *P < .05. (C) MUC-1 expression on MPs from HPAF-II and HPAC cells. MPs in serum-free culture medium from HPAF-II and HPAC cells were incubated with FITC labeled anti–human MUC-1 Ab or FITC-labeled isotype control. Stained MPs were analyzed with an LSRII flow cytometer. Results are shown as histograms of the log fluorescence intensity.