1. H. Yang, Institute of Human Nutrition, Columbia University College of Physicians and Surgeons, 630 West 168th Street, New York, NY 10032, USA.
2. M. Bard and D. A. Bruner, Biology Department, Indiana University-Purdue University at Indianapolis, Indianapolis, IN 46202, USA.
3. A. Gleeson, Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
4. R. J. Deckelbaum, Institute of Human Nutrition and Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
5. G. Aljinovic and T. M. Pohl, GATC-Gesellschaft fur Analyse-Technik und Consulting mbH, Fritz-Arnold-Strasse 23, D-78467 Konstanz, Germany.
6. R. Rothstein, Department of Genetics and Development, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
7. S. L. Sturley, Institute of Human Nutrition and Departments of Pediatrics, Physiology, and Molecular Biophysics, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.