1. Medical Research Council, PROMEC Unit, Tygerberg 7505, South Africa
2. Toxicology and Mycotoxin Research Unit, U.S. Department of Agriculture-ARS, Athens, GA 30605
3. Division of Infectious Disease Epidemiology and Surveillance, Texas Department of Health, Austin, TX 78756
4. Epidemiology and Surveillance Research, American Cancer Society, Atlanta, GA 30329
5. Center for Human Molecular Genetics, Department of Cell Biology & Anatomy Twin Bridges, MT 59754
6. Center for Human Molecular Genetics, Department of Cell Biology & Anatomy; Munroe-Meyer Institute, Nebraska Medical Center, Omaha, NE 68198
7. Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115
8. Genetics Clinic, Department of Pediatrics, Hospital General San Juan de Dios, Guatemala City, Guatemala
9. Instituto de Nutricion de Centroamerica y Panama (INCAP/OPS), Guatemala City, Guatemala
10. School of Chemistry and Biochemistry
11. School of Biology, Georgia Institute of Technology, Atlanta, GA 30332
12. Department of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada