1. National Medical Center (Siglo XXI); Cardiology Hospital; IMSS; Mexico City Mexico
2. Division of Cardiovascular Disease; University of Alabama at Birmingham; Birmingham AL USA
3. Division of Internal Medicine; University of Alabama at Birmingham; Birmingham AL USA
4. Asthma and Allergy Center; Lewisville and Flower Mound TX USA
5. Division of Allergy and Immunology; University of Texas Southwestern Medical Center; Dallas TX USA
6. Allergy and Asthma Center; McLean VA USA
7. National Medical Center (Siglo XXI); Specialties Hospital (Dr. Bernardo Sepulveda); IMSS; Mexico City Mexico