[A decrease in the efficiency of radiation damage repair in HeLa tumor cells with their preliminary irradiation at low radiation doses (0.1 Gr)].

In experiments with tumor HeLa cells, a study was made of the survival rate of both the whole population and individual clonogenic cells after irradiation within different regimes at a cumulative dose of 4 Gy. The results obtained prompt a conclusion that the preirradiation with a dose of 0.1 Gy decreases the efficiency of repair of radiation-induced damages to cells.

[Photosensitized inactivation of HeLa tumor cells by phthalocyanines].

The combined effect of tetrasulfonated phthalocyanine (TSPC, 1.0 microM) or chloroaluminum phthalocyanine (CAPC, 1.0 microM) and copper vapour laser radiation (lambda = 670 nm) causes a dose dependent decrease in the survival rate of HeLa cells at exponential and stationary growth phases estimated by the trypan blue exclusion test or colony-forming ability test.