Antiproliferative effects of BIBR1532 in primary AML blasts. (A) Mononuclear bone marrow cells from AML patients (n = 9; Table 3) were plated in 96-well plates with indicated concentrations of BIBR1532. WST-1 reagent was added after 72 hours for the determination of proliferation, which is expressed as a percentage of the controls ± standard deviation of the mean (SDM). Experiments were performed in triplicate. (B) BIBR1532 (80 μM) induced a gradual decrease of proliferation within 72 hours (> 80%). Bars represent means of percentage of proliferation measured by WST-1 assay at the indicated time points, ± SDM (n = 9). PL indicates placebo (DMSO).