[1] HARVARD UNIV, CTR BLOOD RES, BOSTON, MA 02115 USA
[2] HARVARD UNIV, SCH PUBL HLTH, DEPT NUTR, BOSTON, MA 02115 USA
[3] MASSACHUSETTS GEN HOSP, HARVARD MED SCH, DEPT BIOL CHEM, BOSTON, MA 02114 USA
[4] MASSACHUSETTS GEN HOSP, BIOCHEM RES LAB, BOSTON, MA 02114 USA