1. Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
2. Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea.
3. Department of Internal Medicine, BHS Hanseo Hospital, Busan, Korea.
4. Department of Internal Medicine, Hwa Myung Il Sin Christian Medical Center, Busan, Korea.
5. Dr. Hong's Internal Medicine, Yangsan, Korea.