Search results for "Thrombasthenia"

Identifying human platelet glycoproteins IIb and IIIa by capillary electrophoresis.

1998

Glanzmann thrombasthenia (GT) is an inherited hemorrhagic defect due to a failure of the platelet membrane glycoprotein (GP) IIb–IIIa complex. Capillary electrophoresis (CE) analysis of solubilized platelet membranes from normal individuals showed the presence of two peaks with a migration time of 27 and 29 min, respectively. An excellent run-to-run and day-to-day reproducibility of the technique (< 1% variation of the retention time) was documented. Using an automated Ferguson method, the apparent molecular masses were 100.0 kDa and 138.5 kDa, respectively. Immunoprecipitation with monoclonal antibodies anti-GP IIIa (B59.2.1) and anti-IIb (61.9.1.3) showed the two peaks as IIIa and IIb, re…

Gpibα Engagement Induces Activation of Human Platelet TF and Association with Constitutively Platelet Surface-Bound FVIIa

2019

The membranes of activated platelets assemble clotting protein complexes and enzymatic reactions needed for hemostasis and causing pathological thrombosis. Several reports have shown that human platelets contain TF, but controversies remain on the functional contributions of platelet TF to coagulation initiation. Here, we delineate the mechanism that converts platelet-associated TF to a procoagulant molecule. By combining specific inhibitors with human platelets from normal probands or patients with Glanzmann thrombasthenia or homozygous GPVI deficiency, we analyzed the procoagulant activation of platelet TF by biochemical methods, confocal microscopy, platelet adhesion under flow on VWF an…

2014

AbstractAssays measuring platelet aggregation (thrombus formation) at arterial shear rate mostly use collagen as only platelet-adhesive surface. Here we report a multi-surface and multi-parameter flow assay to characterize thrombus formation in whole blood from healthy subjects and patients with platelet function deficiencies. A systematic comparison is made of 52 adhesive surfaces with components activating the main platelet-adhesive receptors, and of eight output parameters reflecting distinct stages of thrombus formation. Three types of thrombus formation can be identified with a predicted hierarchy of the following receptors: glycoprotein (GP)VI, C-type lectin-like receptor-2 (CLEC-2)&g…