[1] Univ Michigan, Sch Med, Dept Surg, Ann Arbor, MI 48105 USA
[2] Univ Michigan, Sch Med, Dept Dermatol, Ann Arbor, MI 48105 USA
[3] Univ Michigan, Sch Med, Dept Radiat Oncol, Ann Arbor, MI 48105 USA
[4] Univ Michigan, Sch Med, Dept Microbiol & Immunol, Ann Arbor, MI 48105 USA
[5] Ann Arbor Vet Affairs Hosp, Ann Arbor, MI 48105 USA