Combined autoradiographic and cytophotometric study of proliferating cell populations in human gliomas with description of a logarithmic screen method of cytophotometry.

Cell populations of 19 human brain tumors were studied by the combination of autoradiographic and cytophotometric methods. In some tumors there were up to 20% polyploid cells, but in the majority of cases the number of labeled polyploid cells was minimal. In 17 cases, labeled cells were within the range 2c to 4c or 1c to 3c: i.e., mainly near-diploid or hypodiploid cells took part in the proliferation process. In two cases (a malignant astrocytoma and an oligodendroglioma) there were two classes of proliferating cells, diploid and tetraploid. In some cases, large populations of S and G2 cells were found, which were considered to be arrested within the cycle.