Effects of the interval between irradiation and a single injection of PEG-rHuMGDF on peripheral blood cell recovery in irradiated myelosuppressed mice. Mice were irradiated at a dose of 3.5 Gy and intravenously given 80 μg/kg PEG-rHuMGDF 1 (•), 12 (▵), 24 (▴), 36 (□), 48 (▪), or 60 (▿) hours after irradiation, or vehicle (○) 1 hour after irradiation. The data represent 1 of 2 separate experiments.