[1] USN, BLOOD RES LAB, CHELSEA, MA 02150 USA
[2] HARVARD UNIV, PETER BENT BRIGHAM HOSP, SCH MED, DEPT MED, BOSTON, MA 02115 USA
[3] BOSTON UNIV, MED CTR, DEPT HEMATOL, BOSTON, MA 02118 USA
[4] MIT, DEPT NUTR & FOOD SCI, BIOPHYS LAB, CAMBRIDGE, MA 02139 USA