Fig. 1.
DNA histograms of microvascular endothelial cells (MVEC) exposed to normal and TTP plasmas. Primary human microvascular EC from various tissues were cultured for 18 hours in human serum-free apoptosis culture medium in the presence of a 1:100 dilution of plasma from control donors and a 1:100 or 1:1,000 dilution of plasma from TTP patients. DNA histograms of ethanol-fixed, RNase-treated and propidium iodide-stained cells were obtained and analyzed by computer software, as described in the text. A0 peak values are indicated within each histogram, representing the more heavily shaded region just to the left of the large G1/S peak (see [B]). (A) Dermal, renal, and cerebral MVEC + normal plasma. (B) Dermal, renal, and cerebral MVEC + TTP plasmas.