[Effect of hypoxic cell sensitizer metronidazole on the radiation reaction of clonogenic cells from solid tumors]. / Vliianie sensibilizatora gipoksicheskikh kletok metronidazola na radiatsionnuiu reaktsiiu klonogennykh kletok solidnykh opukholei.

The clonogenic capacity of cells from peripheral and central zones of solid NKLy tumors of mice treated with metronidazole, a sensitizer of hypoxic cells, and with a mixture of metronidazole and radiation was studied by cloning in diffusion chambers. The cytotoxic effect of metronidazole was only noted during the prolonged interaction with cells under acute hypoxia that was observed in central tumor zones. Metronidazole increased by more than two times the radiosensitivity of cells from the central zones of the tumor and did not influence the radiation response of cells from the peripheral zones. Metronidazole was shown to inhibit the repair of potentially lethal radiation damages.

[Changes in the clonogenic ability of solid tumor cells during combined exposure to hyperthermia and irradiation]. / Izmenenie klonogennoi sposobnosti kletok solidnykh opukholei pri sovmestnom deistvii gipertermii i oblucheniia.

A study was made of the clonogenic capacity of cells from central and peripheral zones of NKLy solid tumors of mice after heating up to 42 degrees C and after the combined effect of hyperthermia and local irradiation of the tumor. Hyperthermia markedly increased the rate of radiation death of cell populations from central tumor zones, having low oxygen tension, and had no effect on radiosensitivity of cells from peripheral well oxygenated zones. In heated tumors, the repair of potentially lethal radiation damages to cells from the peripheral zones was inhibited while in conventional irradiation conditions these damages could be restored.

[Clonogenic capacity, radiosensitivity and recovery from potentially lethal damage in individual subpopulations of the murine NKLy ascitic tumor]. / Klonogennaia sposobnost', radiochuvstvitel'nost' i voostanovlenie ot potentsial'no letal'nykh povrezhdenii otdel'nykh subpopuliatsii astsitnoi opukholi NKLy myshei.

Effectiveness of the diffusion chamber cloning of subpopulations of cells isolated by the sedimentation method from intact and exposed (5 Gy) mouse tumors NKLy was determined. It was shown that cells at the G2-M stages were highly radiosensitive. The recovery from potentially lethal damages was maximum at the G0-G1 stages of the cell cycle.

[Radiation response of clonogenic cells of solid tumors. Clonogenic capacity of the murine NKLy solid tumor and its oxygen status]. / Reaktsiia klonogennykh kletok solidnykh opukholei na obluchenie. Klonogennaia sposobnost' solidnoi opukholi NKLy myshei i ee kislorodnyi status.

Clonogenic capacity and oxygen tension were determined in peripheral and central zones of solid tumors NKLy in vivo. With low pO2 in central zones (2.69 +/- 0.60 as opposed to 4.64 +/- 0.68 mm m. c. in peripheral zones) and in the presence of anoxic sites, the effectiveness of cloning, with inoculation immediately after isolation of cells from central zones, did not differ from that from peripheral ones (6.36 +/- 0.45 and 6.78 +/- 0.68%, respectively).

[Radiosensitivity of the murine NKLy solid tumor and recovery of clonogenic cells from potentially lethal radiation damage]. / Radiochuvstvitel'nost' solidnoi opukholi NKLy myshei i vosstanovlenie klonogennykh kletok ot potentsial'no letal'nykh radiatsionnykh povrezhdenii.

It was shown by the cloning method that radiosensitivity of cells of central zones was lower than that of peripheral zones (D0=6.70 and 2.91 Gy, respectively). Under conditions of recovery from potentially lethal damages radiosensitivity of clonogenic cells of peripheral zones decreased (D0=6.22 Gy) whereas that of cells from central zones changed insignificantly (D0=7.98 Gy).