Effects of Argon Ions on Synchronized Chinese Hamster Cells

Effect of Neon Ions on Synchronized Chinese Hamster Cells

“…of neon ions for late S-phase cells decreases rapidly with increasing dose, whereas it is nearly constant at the G x /S boundary. This trend of r.b.e.variation with dose for cells in late S and G 1 /S-boundary phases exposed to neon ions at the distal peak is similar to observations made earlier for fast neutrons and argon ions (Gragg et al 1978, Raju et al 1980. Figure 5 shows the percentage of surviving cells plotted as a function of time after release from HU for cells exposed to 5 Gy at the plateau or 3-6 Gy at the distal peak of the neon ion beam, or 108 Gy 6 0 Co y-rays.…”

“…Cells were synchronized by mitotic selection and resynchronized at the G 1 /S boundary using 10-3 hydroxyurea (HU) as described previously (Raju et al 1975(Raju et al , 1980. This procedure spares the cells from any S-phase-specific cytotoxic effects of hydroxyurea.…”

“…beams used in therapy. We have previously reported such measurements for argon ions (Raju et al 1980) where no significant variation in sensitivity was observed as a function of position in the cell cycle. We report here cell-cycle variability in the radiosensitivity of cultured hamster cells (CHO) exposed to neon ions or 6 0 Co y-rays.…”

Heavy-Ion Radiobiology: Cellular Studies

“…Per unit of absorbed dose, the difference in survival response between the two ages is approximately the same for both radiations; however, at doses of each radiation that give the same level of cell killing, the difference in survival Raju et al, 1980b). response between the two ages is much reduced for neon compared to x rays.…”

“…It was not, however, until the late 1960s and early 1970s that the high LET radiations were found to diminish the amplitude of the variation between the most sensitive and the most resistant phases. This effect has been observed with fast neutrons (Sinclair, 1970;Hall, 1969;Masuda, 1971;Hall et al, 1975;Sapozink and Djordjevic, 1974;Gragg et al, 1978), with alpha particles from an isotonic source (Hall et al, 1972;Raju et al, 1975}, with pions (Raju et al, 1978d, with helium ions and with heavy-ion particle beams {Skarsgard 1967; Elkind, 1970;Bird, 1972;Burki, 1971, 1975;Hall et al, 1977;Raju et al, 1980b).…”