Houston Pulmonologist with experience in general internal medicine, pulmonology and sleep medicine management MEDICAL CHEST ASSOCIATES (713) 467-8888. Home. Our Services. Our Doctors. Dr. George Keith; Dr. Minh Tran; Dr. Ajay Jain; Dr. Kiran Nair; Insurance. New Patient Forms/Portal. Patient Portal Access. Blog. Our Offices. More Dr. George ....