1. Institute of Pharmacology & Toxicology; University of Bonn; Bonn; Germany
2. Pharmacology & Toxicology Section; Institute of Pharmacy; University of Bonn; Bonn; Germany
3. Institute of Pharmaceutical Biology; University of Bonn; Bonn; Germany
4. Department Pulmonary Diseases; Med. Clinic and Policlinic II; University Bonn; Bonn; Germany