After surgery, the animals were placed in cages and monitored in the animal laboratory under direct supervision of a physician or a technician until they recovered from anesthesia. Analgesic buprenorphine (0.02-0.05 mg/kg) was administered i.m. for pain or distress. The tumors were allowed to grow for another 10 to 14 days, at which time they reached an ellipsoidal shape with dimensions ranging between 2.5 and 3.5 cm (15).