1) Bean RH. The treatment of chronic ulcerative colitis with 6-mercaptopurine. Med J Aust 42:592-593, 1962
2) Jewell DP, Truelove SC. Azathioprine in ulcerative colitis:final report on a controlled therapeutic trial. BMJ 4:627-630, 1974
3) Rosenberg JL, Wall AJ, Levin B, et al. A controlled trial of azathioprine in the management of chronic ulcerative colitis. Gastroenterology 69:96-99, 1975
4) Kirk AP, Lennard-Jones JE. Controlled trial of azathioprine in chronic ulcerative colitis. BMJ 284:1291-1292, 1982
5) Hawthorne AB, Logan RFA, Hawkey CJ, et al. Randomised controlled trial of azathioprine withdrawal in ulcerative colitis. BMJ 205:20-22, 1992
6) Sood A, Kaushal V, Midha V, et al. The beneficial effect of azathioprine on maintenance of remission in severe ulcerative colitis. J Gastroenterol 37:270-274, 2002
7) Hibi T, Naganuma M, Kitahora T, et al. Low-dose azathioprine is effective and safe for maintenance of remission in patients with ulcerative colitis. J Gastroenterol 38:740-746, 2003
8) Holtmann MH, Krummenauer F, Claas C, et al. Long term effectiveness of azathioprine in IBD beyond 4 years:A European multicenter study in 1176 patients. Dig Dis Sci 51:1516-1524, 2006
9) Hanauer SB, Feagan BG, Lichtenstein GR, et al. Maintenance infliximab for Crohn's disease:the ACCENT I randomized trial. Lancet 359:1541-1549, 2002
10) Rutgeerts P, Diamond RH, Bala M, et al. Scheduled maintenance treatment with infliximab is superior to episodic treatment for the healing ulceration associated with Crohn's disease. Gastrointestinal Endosc 63:433-442, 2006
11) D'Haens G, Geboes K, Ponette E, et al. Healing of severe recurrent ileitis with azathioprine therapy in patients with Crohn's disease. Gastroenterology 112:1475-1481, 1997
12) D'Haens G, Geboes K, Rutgeerts P. Endoscopic and histologic healing of Crohn's(ileo-)colitis with azathioprine. Gastrointest Endosc 50:667-671, 1999
13) Matts SGF. The value of rectal biopsy in the diagnosis of ulcerative colitis. Q J Med 30:393-407, 1961
14) Tiede I, Fritz C, Strand S, et al. CD28-dependent Rac 1 activation is the molecular target of azathioprine in primary human CD4+T lymphocytes. J Clin Invest 111:1133-1145, 2003
15) Schroll S, Sarlette A, Ahrens K, et al. Effects of azathioprine and its metabolites on repair mechanisms of the intestinal epithelium in vitro. Regulatory Peptides 131:1-11, 2005
16) Rutgeerts P, Sandborn WJ, Feagan BG, et al. Infliximab for induction and maintenance therapy for ulcerative colitis. N Engl J Med 353:2462-2476, 2005
17) Ardizzone S, Macconi G, Russo A, et al. Randomised controlled trial of azathioprine and 5-aminosalicyclic acid for treatment of steroid dependent ulcerative colitis. Gut 55:47-53, 2006
18) Burke DA, Dixon MF, Axon ATR. Ulcerative colitis:prolonged remission following azathioprine induced pancytopenia. J Clin Gastroenterol 11:327-330, 1989
19) Persley KM, Present DH. Neutropenia is not required for clinical remission during azathioprine therapy in inflammatory bowel disease. Eur J Gastroenterol Hepatol 13:1053-1055, 2001
20) Glas J, Torok HP, Daczo J, et al. The leukocyte count predicts the efficacy of treatment with azathioprine in inflammatory bowel disease. Eur J Med Res 10:535-538, 2005
21) Thomas Jr. CW, Lowry PW, Franklin CL, et al. Erythrocyte mean corpuscular volume as a surrogate marker for 6-thioguanine nucleotide concentration monitoring in patients with inflammatory bowel disease treated with azathioprine or 6-mercaptopurine. Inflamm Bowel Dis 9:237-245, 2003
22) Nemoto Y, Kanai T, Makita S, et al. Bone marrow retaining colitogenic CD4+ T cells may be a pathogenic reservoir for chronic colitis. Gastroenterology 132:176-189, 2007
23) Jess T, Loftus EV, Velayos FS, et al. Risk factors for colorectal neoplasia in inflammatory bowel disease:A nested case-control study from Copenhagen County, Denmark and Olmsted County, Minnesota. Am J Gastroenterol 102:829-836, 2007