passages.id: split_1_test_1126_passage
passages.type: progene_text
passages.text: The concentrations of tissue plasminogen activator (t-PA ) , urokinase plasminogen activator ( u-PA ) , and plasminogen activator inhibitor type 1 ( PAI-1 ) in cell conditioned medium were determined by ELISA and the level of PAI-1 mRNA was determined using northern hybridisation .