[1] Chiba Univ, Grad Sch Med, Dept Mol Pathol, Chiba, Japan
[2] Hokkaido Univ, Grad Sch Med, Dept Pathol Pathophysiol, Div Pathophysiol Sci, Sapporo, Hokkaido 060, Japan
[3] Tohoku Univ, Grad Sch Med, Dept Pathol, Div Anat Pathol, Sendai, Miyagi 980, Japan