乳癌嫌発系AKRマウスに自然発生した乳癌に関する研究 第3編 乳癌の組織培養細胞に観察されたウィルス粒子の電子顕微鏡的研究

This report is concerned with electronmicroscopic studies on tissue culture cells obtained from a spontaneous mammary carcinoma and it's serially transplanted tumors of AKR mice. Numerous type C virus particles were observed in A-419 line, A-319 line, and A-162 line of tissue culture cells. These particles showed a gradual decrease during the serial passages in vitro. This finding is interesting in view of the fact that numerous type A and B particles but no type C particles were observed in the tumors from which those tissue culture cells were derived. In contrast, mature type B particles were observed in A-600 line tissue culture cells, whereas only a few immature type B particles were observed in the 26th transplant generation of the tumor from which A-600 line cells were derived. The results obtained suggest a possible interference between type A and B particles and type C particles. Bioassays of tissue culture fluids from A-419, A-162, and A-600 lines induced neither leukemia nor mammary carcinoma in test mice.