Cells, radiation effects

Nicotinamide potentiates the cytotoxic effects of chemotherapy and radiation treatment against tumor cells. This effect is probably attributable to increased... 

Genetic Effect of Radiation—Inheritable change, chiefly mutations, produced by the absorption of ionizing radiation by germ cells. Genetic effects have not been observed in any human population exposed at any dose level. 

Goldman, M., An overview of high LET radiation effects in cells, in The Health Effects of Plutonium and Radium (W. S. S. Jee, ed.), pp. 751-766, J. W. Press, Salt Lake City, Utah (1976). 

Harold J. Hovel, Introduction Carrier Collection, Spectral Response, and Photocurrent Solar Cell Electrical Characteristics Efficiency Thickness Other Solar Cell Devices Radiation Effects Temperature and Intensity Solar Cell Technology... 

The target for optimization in FTA with CL detection is to adjust all experimental factors in such a way so that the detector views as much radiation as possible while the chemiluminescent solution flows through the cell. Hence the kinetics of the flow and detector system should be monitored to match the kinetics of the reaction and generate maximum intensity inside the cell. The effect of experimental variables on the CL signal cannot be exactly predicted in advance and there is not enough theoretical background to support any suggestion. 

Investigations of the cellular effects of radiofrequency radiation provide evidence of damage to various types of avian and mammalian cells. These effects involve radiofrequency interactions with cell membranes, especially the plasma membrane. Effects include alterations in membrane cation transport, Na+/K+-ATPase activity, protein kinase activity, neutrophil precursor membrane receptors, firing rates and resting potentials of neurons, brain cell metabolism, DNA and RNA synthesis in glioma cells, and mitogenic effects on human lymphocytes (Cleary 1990). 

Arundel-Suto CM, Scavone SV, Turner WR, Suto MJ, Sebolt-Leopold JS (1991) Effect of PD 128763, a new potent inhibitor of poly(ADP-ribose) polymerase, on X-ray-induced cellular recovery processes in Chinese hamster V79 cells. Radiat Res 126 367-371... 

Mechanisms by which ionizing radiation induces leukemia are of fundamental importance. Secondary myelodysplastic syndrome (MDS) is referred as one of stochastic late radiation effects and a stage for leukemia development. CD34-h cell counts were elevated both in BM and PB and significantly higher than in non-exposed. Blasts were identified as... 

Zeflars R, Naida J, Davis MA, et al. The effect of p53 overexpression on radiation sensitivity of human colon cancer cells. Radiat Oncol Investing 1997 5 43 49. 

Although the precise mechanism of action of paclitaxel in enhancing radiation effects is not clear, one of the proposed mechanisms is its effect on the cell cycle. Its effects on the microtubules result in an M-phase arrest (55). Experiments done on synchronously dividing Chinese hamster cells have shown that cells in M and G2 are most sensitive to the effects of radiation (56). 

Ellis LC, Berliner DL. 1967. The effects of ionizing radiations on endocrine cells. Radiation Res 32 520-537. 

Some radiation effects result from nonlethal damage to a single cell. These effects are called stochastic. They have the property that there is no threshold for these effects to occur. It is the probability of occurrence rather than its severity which increases with dose. The causation of some cancers may be rooted in a stochastic effect. 

Radiation-induced genomic instability and bystander effects are now well-established consequences of exposure of living cells to ionizing radiation. Cells not directly traversed by radiation may still exhibit radiation effects. This phenomenon, known as bystander effect, has become a major activity in radiation biology and in some cases has challenged the conventional wisdom. An example is the currently accepted models used for low-dose extrapolation of radiation risks. The currently used models assume that cells in an irradiated population respond individually rather than collectively. If bystander effects have implications for health risks estimates from exposure to ionizing radiation, then the question of whether this is a general phenomenon or solely a characteristic of a particular type of cell and the radiation under test becomes an important issue. 

Radioisotopes are also used in radiation therapy to treat cancer. The goal in radiation therapy is to kill malignant cells, while protecting healthy tissue from radiation effects. Radioisotopes such as yttrium-90, a beta emitter, may be placed directly in the tumor. Alternatively, the diseased tissue may be subjected to beams of gamma radiation. Cobalt-60 used in radiation therapy is prepared by a series of transmutations ... 

Space-based solar cells are covered with a very thin layer of vitreous silica to protect against the damaging environment of space such as atomic oxygen, micrometeorites, and radiation effects. Because the silica is transparent to damaging uv radiation, it is normally coated with a uv-reflective thin film... 

It is seen from this table that, at the LD50 level, the nucleus has received about the same dose, irrespective of whether X-rays, 3H-dThd or 125I-concanavalin are used as the source of ionizing radiation, while the membrane has received an immense dose with 125I-concanavalin and very little with 3H-dThd. As expected, the cytoplasm lies in between these two extremes. Yet, irradiation of the cytoplasm (single-ion-beam experiments) is not without an effect. It may cause mutations (Wu et al. 1999) and the formation of products that induce apoptosis in nearby (unirradiated) cells (bystander effect Shao et al. 2004). 

Hall EJ (1982) CROS Conference on chemical modification - radiation and cytotoxic drugs. Welcome and overview. Int J Radiat Oncol Biol Phys 8 323-325 Hamer DH (1986) Metallothionein. In Richardson CC, Boyer PD, Dawid IB, Meister A (eds) Annual review of biochemistry. Annual Reviews, Inc., Palo Alto, pp 913-951 Han A, Sinclair WK, Kimler BF (1976) The effect of N-ethylmaleimide on the response to X rays of synchronized HeLa cells. Radiat Res 65 337-350... 

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