Carp R I, Merz G S, Licursi P C
Infect Immun. 1976 Jul;14(1):163-7. doi: 10.1128/iai.14.1.163-167.1976.
Exposure of PAM cells, a spontaneously transformed mouse cell line, to brain homogenates from mice infected with scrapie caused a relative decrease in total cell yield, which persisted from passage 2 or 3 to passage 18 after treatment. The effect was elicited by each of the eight independent scrapie isolates tested. Lysates prepared from cultures 16 passages after treatment with scrapie caused the decrease when applied to fresh PAM cultures. Mice inoculated with passage 14 and 18 lysates developed a reduced percentage of polymorphonuclear neutrophils by 5 weeks and scrapie disease by 6 to 9 months after inoculation. Based on the total dilution from treatment of the PAM cultures with scrapie material to the preparation of the lysates, we conclude that the agent(s) responsible for the reduced PAM cell yield, the decreased percentage of polymorphonuclear neutrophils, and the induction of scrapie disease had replicated in the PAM cells. By filtration, the diameter of the agent causing the reduction in cell yield was estimated to be between 25 and 50 nm.
将PAM细胞（一种自发转化的小鼠细胞系）暴露于感染瘙痒病的小鼠脑匀浆中，会导致总细胞产量相对下降，这种下降在处理后的第2或3代至第18代持续存在。所测试的8种独立瘙痒病分离株中的每一种都引发了这种效应。用瘙痒病处理16代后的培养物制备的裂解物应用于新鲜PAM培养物时会导致细胞产量下降。接种第14代和第18代裂解物的小鼠在接种后5周时多形核中性粒细胞百分比降低，6至9个月时出现瘙痒病。根据用瘙痒病材料处理PAM培养物到制备裂解物的总稀释度，我们得出结论，导致PAM细胞产量降低、多形核中性粒细胞百分比降低以及诱导瘙痒病的病原体已在PAM细胞中复制。通过过滤，估计导致细胞产量降低的病原体直径在25至50纳米之间。
