00303nas a2200133   4500000000100000000000100001008004100002100001300043700001200056245005300068300001000121490000600131022003200137       1998                            d1 aL. Derby1 aH. Jick00aAppendectomy protects against ulcerative colitis  a205-70 v9  a1044-3983 (Print) 1044-3983