6. Must have acceptable laboratory criteria within 28 days before enrollment. Acceptable lab parameters include: -Hemoglobin: women: >11.0 g/dL; men >12.5 g/dL -White blood cell count: >3,700 cells/mm3 but <11,000 cells/mm3 -Platelets: >125,000 but <375,000 per mm3 -Urine dipstick (clean urine sample): protein <1+, glucose negative -Alanine aminotransferase and aspartate aminotransferase (ALT, AST) <1.25 x institutional upper limit of normal -Blood urea nitrogen (BUN) </=1 x institutional upper limit of normal -Total bilirubin <1.25x institutional upper limit of normal. Serum creatinine </=1 x institutional upper limit of normal -If laboratory screening tests are out of range, repeat of screening tests is permitted once, provided there is an alternative explanation for the out of range value.