1. William S. Middleton Memorial Veterans Hospital, 2500 Overlook Terrace, Madison, WI 53705.
2. Department of Surgery, University of Wisconsin School of Medicine and Public Health, 750 Highland Ave, Madison, WI 53726.
3. Department of Medicine, University of Wisconsin School of Medicine and Public Health, 750 Highland Ave, Madison, WI 53726.
4. Durham Veterans Affairs Medical Center, 508 Fulton St, Durham, NC 27705.
5. Department of Medicine, Duke University, Durham, NC 27708.