1. Unit of Respiratory Medicine, Department of Experimental Medicine, University of Rome “Tor Vergata”, Rome, Italy
2. Unit of Pharmacology, Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
3. Division of Respiratory Medicine, University Hospital “Tor Vergata”, Rome, Italy
4. Respiratory Disease and Lung Function Unit, Department of Medicine and Surgery, University of Parma, Parma, Italy