1. Department of Cerebrovascular Disease, National Cardiovascular Center, Osaka, Japan
2. Institute for Advanced Medical Sciences, Hyogo College of Medicine, Hyogo, Japan
3. Department of Hematology, Osaka Minami National Medical Center, Osaka, Japan
4. Dean's Office, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
5. Department of Internal Medicine, Hyogo College of Medicine, Hyogo, Japan