[1] OSAKA UNIV HOSP,CENT LAB CLIN INVEST,FUKUSHIMA,OSAKA,JAPAN
[2] OSAKA UNIV,SCH MED,DEPT INTERNAL MED 3,OSAKA,JAPAN
[3] OSAKA MED SCH,DEPT LEGAL MED,TAKATSUKI,JAPAN
[4] STATENS INST FOLKEHELSE,DEPT IMMUNOL,OSLO,NORWAY
[5] UNIV TOKYO,DEPT BIOPHYS & BIOCHEM,TOKYO 113,JAPAN
[6] UNIV OCCUPAT & ENVIRONM HLTH,SCH MED,KITAKYUSHU,FUKUOKA 807,JAPAN