Platelet activation via PAR4 is involved in the initiation of thrombin generation and in clot elasticity development.

Thrombin is a pivotal enzyme formed in the coagulation cascade and an important and potent platelet activator. The two protease-activated thrombin receptors on human platelets are denoted PAR1 and PAR4. The physiological relevance of PAR4 is still unclear, as both aggregation and secretion can be accomplished by PAR1 activation alone.

Measurement of paclitaxel and its metabolites in human plasma using liquid chromatography/ion trap mass spectrometry with a sonic spray ionization interface.

A quantitative liquid chromatography/ion trap mass spectrometry method for the simultaneous determination of paclitaxel, 6alpha-hydroxypaclitaxel and p-3'-hydroxypaclitaxel in human plasma has been developed and validated. 6alpha-,p-3'-Dihydroxypaclitaxel was also quantified using paclitaxel as a reference and docetaxel as an internal standard. The substances were extracted from 0.