1. Department of Medical Research (Lower Myanmar), No. 5 Ziwaka Road, 11191 Yangon, Republic of the Union of Myanmar
2. Central Research Laboratories, Nichinichi Pharmaceutical Corporation Ltd., Mie 518-1417, Japan
3. Department of Gastrointestinal Immunology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
4. Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-0811, Japan