Shigeo Koido, Toshifumi Ohkusa, Kan Uchiyama, Hiroshi Arakawa, Hisao Tajiri, Division of Gastroenterology and Hepatology, Department of Internal Medicine, the Jikei University School of Medicine, Chiba 277-8567, Japan
Hiroaki Saito, Tomoyoshi Shibuya, Naoto Sakamoto, Taro Osada, Akihito Nagahara, Sumio Watanabe, Department of Gastroenterology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
Tetsuji Yokoyama, Department of Health Promotion, National Institute of Public Health, Saitama 351-0197, Japan
Author contributions: Koido S, Ohkusa T, Saito H, Watanabe S, and Tajiri H designed the research; Koido S, Ohkusa T, Saito H, Yokoyama T, Shibuya T, Sakamoto N, Uchiyama K, Arakawa H, Osada T, and Nagahara A performed the research and analyzed the data; Koido S and Ohkusa T wrote the paper.
Supported by Grants in Aid for Scientific Research (C) from the Japanese Ministry of Education, Culture, Sports, Science, and Technology, No. 23501289
Correspondence to: Shigeo Koido, MD, Division of Gastroenterology and Hepatology, Department of Internal Medicine, the Jikei University School of Medicine, 8 Chome-3-1 Kokuryocho, Chiba 277-8564, Japan. firstname.lastname@example.org
Telephone: +81-4-71641111 Fax: +81-4-71633488.
Received: July 21, 2013
Revised: September 12, 2013
Accepted: September 29, 2013
Published online: December 21, 2013