1. National Institute of Medical Sciences and Nutrition Salvador Zubirán (INCMNSZ), Mexico City, Mexico.
2. Hospital Infantil de México Federico Gómez, Mexico City, Mexico.
3. National Institute of Respiratory Diseases (INER), Mexico City, Mexico.
4. Department of Internal Medicine, Weill Cornell Medical College, New York, New York.
5. Tecnológico de Monterrey, Mexico City, Mexico.