Cytopathic Changes Associated With Poliomyelitis Infections In Human Amnion Cells

The cellular changes associated with polio virus infections in human amnion cultures differ from previously studied cells (HeLa, monkey kidney, and human fetal cells) in that (1) the release of newly formed virus occurs 4–8 hours later, (2) the nucleolus becomes indistinguishable before other gross cellular changes occur, (3) spherical projections, or nodules, appear over the free surface of cells, (4) the time of appearance of such nodular cells is coincidental with the time of virus release, and (5) occasional cultures of amnion undergo different terminal degenerative changes in which the cells become very highly vacuolated.