51.   Platelet activating factor may be involved in the pathogenesis of ulcerative colitis as well as in experimental colitis.

52.   However, the effect of specific inhibition of platelet activating factor by a specific receptor antagonist has so far been evaluated in models of experimental colitis only.

53.   We reported recently that colonic mucosa from patients with ulcerative colitis produce high values of platelet activating factor, a potent proinflammatory lipid mediator.

54.   Icos hopes to begin clinical trials this year of PAF-AH, an enzyme that shuts off platelet activating factor, a cause of inflammation.

55.   It inhibits carboxylase, the enzyme that activates clotting factors and also shuts them down before they get out of hand.