[1] Merck & Co Inc, Whitehouse Stn, NJ 08889 USA
[2] Univ Hosp, Dept Resp Med & Allergol, SE-22185 Lund, Sweden
[3] Univ Copenhagen Hosp, Dept Paediat, DK-2900 Copenhagen, Denmark
[4] Hosp Arnaud Villeneuve, Serv Malad Resp, F-34295 Montpellier 5, France
[5] Univ Modena, Dept Resp Dis, I-41100 Modena, Italy
[6] Western Gen Hosp, Resp Med Unit, Edinburgh EH4 2XU, Midlothian, Scotland
[7] Helsinki Univ Hosp, Dept Allergol, FIN-00029 Helsinki, Finland
[8] Southampton Gen Hosp, Resp Cell & Mol Biol Res Div, Southampton SO16 6YD, Hants, England
[9] Univ Barcelona, Hosp Clin, Inst Pneumol, Serv Pneumol, E-08036 Barcelona, Spain