[1] Univ Iowa, Coll Med, Dept Internal Med, Iowa City, IA 52242 USA
[2] Univ Iowa, Coll Med, Dept Pharmacol, Iowa City, IA 52242 USA
[3] Vet Affairs Med Ctr, Iowa City, IA 52246 USA
[4] Univ N Carolina, Dept Pathol, Chapel Hill, NC 27599 USA
[5] Oregon Reg Primate Res Ctr, Beaverton, OR 97006 USA