[1] Natl Inst Resp Dis, COPD Clin, Calzada Tlalpan 4502 Secc 16, Mexico City 14080, DF, Mexico
[2] Natl Inst Resp Dis, Dept Res Tobacco Smoking & COPD, Calzada Tlalpan 4502 Secc 16, Mexico City 14080, DF, Mexico
[3] Med Sur Clin & Fdn, Puente Piedra 150, Mexico City 14050, DF, Mexico
[4] Univ Campania Luigi Vanvitelli, Pharmacol Unit, Dept Expt Med, Viale Abramo Lincoln 5, I-81100 Naples, Italy
[5] Univ Roma Tor Vergata, Chair Resp Med, Dept Expt Med & Surg, Via Montpellier, I-00133 Rome, Italy