Extent of platelet immobilization to a collagen-coated surface in GTA. The platelet mobility index (Materials and Methods) during 2-second observation period was calculated at 1 minute (upper panels) and 7 minutes (lower panels) of perfusion of blood from a patient (numbered as “−1”) with GTA (▵) under a shear rate of 50 s−1 (left panels) and 1,500 s−1 (right panels). At either shear rate, the relatively high platelet mobility index of a normal control (•) at 1 minute of perfusion decreased significantly at 7 minutes of perfusion, indicating that firm platelet adhesion progressed as a function of time. Note that the platelet mobility index for GTA, which was higher than that of normal at 1 minute of perfusion, decreased only slightly at 7 minutes of perfusion, indicating only limited firm adhesion of platelets in GTA during perfusion.
