[1] HARVARD UNIV, SCH MED, HOWARD HUGHES MED INST LAB, BOSTON, MA 02115 USA
[2] HARVARD UNIV, SCH MED, DEPT MED, BOSTON, MA 02115 USA
[3] MASSACHUSETTS GEN HOSP, MED SERV, BOSTON, MA 02114 USA
[4] MASSACHUSETTS GEN HOSP, DIABET UNIT, BOSTON, MA 02114 USA