Platelet u-PA and β-actin mRNA, analyzed by RT-PCR.

u-PA and β-actin transcripts were amplified separately before running the products in lanes of the gel. Lanes compare transcripts amplified from platelets of 2 controls (C) and 3 patients with the QPD (Q), with transcripts from TPA-stimulated K562 cells. QPD platelets contained normal amounts of β-actin mRNA and increased u-PA mRNA, which was not detectable in control platelets.