[In vitro studies of DNA synthesis inhibition by hyperthermia (42.5 degrees C, 120 min) and cytostatic drugs in embryonal tumors and sarcomas in childhood].

The effect of hyperthermia (HT), (42.5 degrees C, 120 min), cytostatic agents and the simultaneous application of HT and cytostatics on embryonal tumors and sarcomas in children was studied using an autoradiographic in vitro method. The 3H-thymidine and 3H-uridine incorporation inhibition was measured. HT inhibits DNA and RNA synthesis in a range of 42.0%-51.0% and 45.6%-58.3%. HT enhances the effect of the cytostatic agents ADM, CPM, cis-PL, BLM and BCNU highly significantly. In each case and without exception the simultaneous application of HT and cytostatics overcomes primary resistance to HT or the cytostatic concerned.