1. 1) Present address: Division for Evaluation and Analysis of Drug Information, Center of Clinical Pharmacy and Clinical Sciences, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
2. 2) Munkholm P., Langholz E., Davidsen M., Binder V., Gut, 35, 360-362 (1994).
3. 3) Greenberg G. R., Feagan B. G., Martin F., Sutherland L. R., Thomson A. B., Williams C. N., Nilsson L. G., Persson T., N. Engl. J. Med., 331, 836-841 (1994).
4. 4) Munakata A., Shimoyama T., “The Ministry of Health and Welfare of Japan,” March 1999.
5. 5) Sandborn W. J., Sutherland L. R., Pearson D. C., May G. R., Modigliani R., Prantera C., “The Cochrane Database of Systematic Reviews,” Issue 2, The Cochrane Collaboration, Oxford, 2000.