The intrasplenic inoculation of A K R lymphoma cells into I-month-old BALB mice, followed by a syngerieic intraperitoneal passage, led to the development of short-latency leukemia of host origin within 24 days; the incidence of leukemia averaged 83% in 88 mice. Electron microscopic studies revealed the presence of intracisternal A and extracellular C-type viral particles in leukemic lymph nodes. These results were obtained with eight A K R lymphoma inocula out of 107 trials and were never observed in BALB controls and with normal A K R spleen inoculum, except in one animal. In the surviving groups, the incidence of long-latency leukemia, averaging 19 months, was significantly increased to 45 % in the 541 mice which had received A K R lymphoma inocula, as compared to 30% in those receiving normal A K R spleen inocula; the latter value was also significantly higher than the 15% spontaneous incidence of the BALB strain. A number of tumors were observed in the experimental groups. Antigenic studies, using the indirect cytotoxic test, demonstrated the presence of the G (Gross) antigen, in both short-and long-latency leukemias.

No abstract

No abstract