[1] NIDDK, NIH, Digest Dis Branch, Bethesda, MD 20892 USA
[2] Univ Calif San Francisco, Dept Surg, San Francisco, CA 94143 USA
[3] San Francisco Vet Affairs Med Ctr, San Francisco, CA USA
[4] NCI, Surg Metab Sect, Surg Branch, Bethesda, MD 20892 USA
[5] NCI, Biostat & Data Management Sect, Bethesda, MD 20892 USA
[6] NIH, Dept Diagnost Radiol, Warren Grant Magnuson Clin Ctr, Bethesda, MD 20892 USA