RT Journal Article SR Electronic T1 Measurement of tumour necrosis factor α JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 454 OP 455 DO 10.1136/gut.49.3.454a VO 49 IS 3 A1 A AUSTIN YR 2001 UL http://gut.bmj.com/content/49/3/454.2.abstract AB