1. a Center for Musculoskeletal Health, Department of Internal Medicine, Sacramento, California, USA
2. b Department of Emergency Medicine, Center for Difficult Diagnoses and Rare Diseases, Second Xiangya Hospital of the Central-South University, Hunan, Changsha, People's Republic of China
3. c Stem Cell Program, UC Davis Health System, Institute for Regenerative Cures, University of California Davis Medical Center, Sacramento, California, USA
4. d Adult Programs Division, California Department of Social Services, Sacramento, California, USA