1. Division of Geriatric Research, Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL 62702, USA
2. Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL 62702, USA
3. Current Affiliation: Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02115, USA
4. Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA
5. Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
6. The Diabetes Institute at Ohio University, Ohio University, Athens, OH 45701, USA