1. Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8501, Japan
2. Department of Gastroenterology and Department of Pathology and Oncology, Juntendo University School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
3. Department of Anatomy and Histology and Department of Organ Regulatory Surgery, Fukushima Medical University School of Medicine, Hikarigaoka, Fukushima 960-1295, Japan
4. Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
5. Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai 980-8575, Japan
6. Department of Medicine, Samsung Medical Center, Kangnam-ku, Seoul 135-710, Korea