[1] Keio Univ, Sch Med, Div Pulm Med, Dept Med, Tokyo 1608582, Japan
[2] Hokkaido Univ, Sch Med, Dept Med 1, Sapporo, Hokkaido 060, Japan
[3] Hokkaido Univ, Sch Med, Dept Surg Oncol, Sapporo, Hokkaido 060, Japan
[4] Washington Univ, Sch Med, Dept Med, Div Pulm & Crit Care Med, St Louis, MO 63110 USA
[5] Barnes Jewish Hosp, St Louis, MO 63110 USA