Comparison of positive rates of COX-2 immunoreactivities between open and closed ulcers
| COX-1 positive (%) | COX-2 positive (%) | |
| Open ulcers (n=30) | 27 (90) | 27 (90) |
| Closed ulcers (n=15) | 15 (100) | 7 (47)2-160 |
↵2-160 p<0.005 v COX-2 positive rates at open ulcers.