Comment on Mechanism of Radiation Effects with Special Reference to Transformation

Watt, D.E.

doi:10.1080/09553009214550891

Cited by 2 publications

(1 citation statement)

References 21 publications

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“…They are related to genetic processes caused by mutations of genes (oncogenes) involved in normal cell growth. Oncogenic transformations induced by IR, could provide answers to fundamental questions; i.e., whether the deoxyribonucleic acid (DNA) damage is responsible for such end-point [8]. Unrepaired or incorrectly repaired DNA damage can lead to serious genome aberrations or mutations, potentially affecting cell survival.…”

Section: Introductionmentioning

confidence: 99%

The unified approach of radiation action on biological matter: The induction of oncogenic transformation by heavy charged particles in C3H10T1/2 cells

Alkharam¹,

Yusuf²

2022

Global J. Eng. Tech. Adv.

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The induction of oncogenic transformation to C3H10T1/2 cells by different types of ionizing radiation has been widely studied in various radiological laboratories. Based on the information available in literature, a database is structured to include radiological parameters, that manifest oncogenic effects as well as cellular inactivation of C3H10T1/2 cells, resulted from exposure to different types of heavy charged ions including neutrons. We find that oncogenic transformation effective cross-section is best correlated with mean free path for linear primary ionization. A simple radiobiological model is proposed merely to quantize cross-sections against mean free path. The model reveals saturations of; cellular inactivation cross-section of about 75 mm2, and oncogenic transformation cross-section of about 3.98 x 10-2 mm2, both started at mean free path of 1.8 nm (inflection points) and lower values. Since the interspacing distance between the DNA strands is about 1.8 nm, the model explains the crucial roles of DNA lesions (caused by heavy charged particles) to play as the starting point leading to cell death or oncogenic transformation. The effective cross -sections in the sloping regions are primarily due to repairable DNA single strand breaks while saturation regions are essentially due to unrepaired or incorrectly repaired DNA double strand breaks.

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Section: Introductionmentioning

confidence: 99%

The unified approach of radiation action on biological matter: The induction of oncogenic transformation by heavy charged particles in C3H10T1/2 cells

Alkharam¹,

Yusuf²

2022

Global J. Eng. Tech. Adv.

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Application of the Constant Exposure Time Technique to Transformation Experiments with Fission Neutrons: Failure to Demonstrate Dose-rate Dependence

Balcer‐Kubiczek

Harrison²,

Torres

et al. 1994

International Journal of Radiation Biology

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A direct comparison of the effectiveness of fission neutrons at high (11.0-31.3 cGy/min) or several low dose-rates (0.14-3.2 cGy/min) was carried out under identical conditions. Monolayers of exponentially growing C3H/10T1/2 cells were exposed at 37 degrees C to reactor-produced neutrons (fluence-mean energy En = 0.68 MeV, < or = 5% gamma component, frequency mean linear energy yF = 21 keV/micron, dose mean lineal energy yD = 42 keV/micron in an 8-micron spherical cavity). Survival or transformation induction were studied at five doses from 10.5 to 94 cGy. In low dose-rate irradiations, these doses were protracted over 0.5, 1, 3 or 4.5 h, resulting in 17 different dose-rates. Up to six experiments were performed at each of five exposure times. Concurrently with transformation we studied cell proliferation in control versus cells irradiated at 40 cGy (acute and a 4.5-h protraction) and found no evidence of a shift in the cell cycle distribution among these cells. At a given dose and dose-rate, the effect of dose protraction on survival or transformation was assessed by the dose-rate modifying factor (DRMF), defined as the low:high dose-rate effect ratio at the same dose. Survival or transformation induction curves were nearly linear with initial slopes, respectively, of about 6.5 x 10(-3) or 6.2 x 10(-6) cGy-1. Consistent with dose-response curves, DRMFs were independent of the dose and dose-rate. The mean values of the DRMF with their uncertainties and 99% confidence intervals, based on measurements in individual doses and dose-rates for survival or transformation were, respectively: 1.01 +/- 0.03 (0.92, 1.09) or 0.98 +/- 0.04 (0.83, 1.08) indicating a similar precision in determining DRMF for survival or transformation, and no dose or dose-rate influence on these end points.

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Comment on Mechanism of Radiation Effects with Special Reference to Transformation

Cited by 2 publications

References 21 publications

The unified approach of radiation action on biological matter: The induction of oncogenic transformation by heavy charged particles in C3H10T1/2 cells

The unified approach of radiation action on biological matter: The induction of oncogenic transformation by heavy charged particles in C3H10T1/2 cells

Application of the Constant Exposure Time Technique to Transformation Experiments with Fission Neutrons: Failure to Demonstrate Dose-rate Dependence

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