[1] Merck Res Labs, Dept Biostat, Rahway, NJ 07065 USA
[2] Hop Laval, Ctr Rech, Bronchol Unit, Ste Foy, PQ, Canada
[3] Merck Res Labs, Dept Pulm Immunol, Stat Program, Rahway, NJ 07065 USA
[4] New England Res Ctr Inc, N Dartmouth, MA USA
[5] Ctr Diagnost & Readaptat Resp, Paris, France