1. Medicine Service, Veterans Affairs San Diego Healthcare System, San Diego, California, USA
2. Department of Medicine, University of California, San Diego, California, USA
3. Department of Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
4. Department of Physiological Chemistry, University of Veterinary Medicine, Hannover, Germany
5. Department of Pediatrics, University of California, San Diego, California, USA
6. Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, California, USA