vTK/GCV induced liver failure in chimeric SCID/uPA mice.

GCV dosing in chimeric SCID/uPA/vTK and vTK− littermates. The degree of human chimerism was determined by serum ELISA for hAAT of blood drawn at 8 weeks post-transplant (baseline), just 1 hour prior to administration of 0, 25 and 100 mg/kg GCV (i.p.) every 48 hours for up to 14 days at which time the experiment had to be terminated, and all animals sacrificed, due to morbidity of vTK expressing mice that received 25 and 100 mg/kg GCV (with the exception of V241, which had to be euthanized after 10 days of GCV dosing). Health status at the end of the treatment period ranged from excellent (+++), to poor (++), to critical and requiring euthenasia (+) as displayed by weight loss (>10% of pretreatment body mass), decreased activity and lethargy, ruffled fur, and hunched posture. ND: not determined.