[1] Osaka Univ, Sch Med, Dept Geriatr Med, Suita, Osaka 5650871, Japan
[2] Nippon Med Sch, Inst Gerontol, Dept Biochem & Cell Biol, Kanagawa 2118533, Japan
[3] Kanazawa Med Univ, Dept Geriatr Med, Kanazawa, Ishikawa 9200293, Japan
[4] Osaka Univ, Sch Med, Dept Anat & Neurosci, Suita, Osaka 5650871, Japan
[5] Osaka Municipal Kohsaiin Hosp, Dept Med, Suita, Osaka 5650873, Japan
[6] Osaka Med Coll, Dept Neuropsychiat, Takatsuki, Osaka 569, Japan
[7] Hyogo Prefectural Amagasaki Hosp, Dept Neuropsychiat & Neurol, Amagasaki, Hyogo 660, Japan
[8] Ehime Univ, Sch Med, Dept Geriatr Med, Matsuyama, Ehime 7920204, Japan