[Quantitative study on DNA content and nucleolar organiser regions in astrocytoma]

Forty-one astrocytomas of different grades were studied by means of image analysis technique for measuring DNA content in situ, and in 28 tumors the numbers of nucleolar organiser region (NORs) associated proteins were also determined, and 12 cases of astrocytoma in frontal lobes were followed up. The results showed that the distribution of DNA content in grade I astrocytoma was 2C-4C, the peak values of grade I astrocytoma was 2C; while for grade II, 3C-4C and hypertetraploid. DNA contents of grade III and IV astrocytomas were much higher, their histograms were dispersed with many peaks, the peak values were aneuploid and heteroploid. The data confirm that heteroploid and aneuploid are the marks of malignancy. The grade II astrocytoma which possesses these features has a tendency to higher malignancy. Twenty-eight astrocytomas were stained by Argyrophil (Ag-NOR) for NOR associated proteins. The largest numbers of Ag-NORs were seen in grades III and IV astrocytoma (mean 11.71), and their Ag-NORs were irregular. Grade I astrocytoma possessed the fewest Ag-NORs (mean 6.5) which were small and uniform. The results suggest that the number of Ag-NORs is associated with the differentiation. The prognosis is significantly correlated with the numbers of Ag-NORs and the contents of DNA in astrocytomas.