1. Research fellow in the Department of Thoracic and Cardiovascular Surgery at the University of Texas MD Anderson Cancer Center
2. Senior investigator in the Department of Emergency Medicine at the Boston Medical Center at the Boston University School of Medicine
3. Associate vice president of clinical research at the University of Texas Health Science Center at Houston in the McGovern Medical School
4. Professor of surgery in the Department of Thoracic and Cardiovascular Surgery at the University of Texas MD Anderson Cancer Center
5. Vice dean for clinical research at the University of Texas Health Science Center at Houston in the McGovern Medical School