Journal ArticleDOI
Radioadaptive response revisited.
Soile Tapio,Vesna Jacob +1 more
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TLDR
Although adaptive response seems to function by an on/off principle, it is a phenomenon showing a high degree of inter- and intraindividual variability, it remains to be seen to what extent adaptive response is functional in humans at relevant dose and dose-rate exposures.Abstract:
Radiation-induced adaptive response belongs to the group of non-targeted effects that do not require direct exposure of the cell nucleus by radiation. It is described as the reduced damaging effect of a challenging radiation dose when induced by a previous low priming dose. Adaptive responses have been observed in vitro and in vivo using various indicators of cellular damage, such as cell lethality, chromosomal aberrations, mutation induction, radiosensitivity, and DNA repair. Adaptive response can be divided into three successive biological phenomena, the intracellular response, the extracellular signal, and the maintenance. The intracellular response leading to adaptation of a single cell is a complex biological process including induction or suppression of gene groups. An extracellular signal, the nature of which is unknown, may be sent by the affected cell to neighbouring cells causing them to adapt as well. This occurs either by a release of diffusible signalling molecules or by gap-junction intercellular communication. Adaptive response can be maintained for periods ranging from of a few hours to several months. Constantly increased levels of reactive oxygen species (ROS) or nitric oxide (NO) have been observed in adapted cells and both factors may play a role in the maintenance process. Although adaptive response seems to function by an on/off principle, it is a phenomenon showing a high degree of inter- and intraindividual variability. It remains to be seen to what extent adaptive response is functional in humans at relevant dose and dose-rate exposures. A better understanding of adaptive response and other non-targeted effects is needed before they can be confirmed as risk estimate factors for the human population at low levels of ionising radiation.read more
Citations
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Journal ArticleDOI
Assessing cancer risks of low-dose radiation
TL;DR: Whether differences exist between the effects mediated by high- and low- dose radiation exposure and how this affects the assessment of low-dose cancer risk is considered.
Journal ArticleDOI
γ-H2AX Foci as a Biomarker for Patient X-Ray Exposure in Pediatric Cardiac Catheterization Are We Underestimating Radiation Risks?
TL;DR: &ggr;-H2AX foci as a biomarker for DNA damage indicate that radiation risk estimates according to the linear-no-threshold hypothesis are possibly underestimates, and great care should be taken to minimize and optimize patient radiation exposure.
Journal ArticleDOI
Cellular radiosensitivity: how much better do we understand it?
Penny A. Jeggo,Martin F. Lavin +1 more
TL;DR: This review discusses the current understanding of the impact of radiation on the cell and the organism gained from the array of past and present studies and attempts to provide an explanation for what it is that determines the response to radiation.
Journal ArticleDOI
Review and evaluation of updated research on the health effects associated with low-dose ionising radiation
Lawrence T. Dauer,Antone L. Brooks,David G. Hoel,William F. Morgan,Daniel O. Stram,Phung K. Tran +5 more
TL;DR: It is concluded that the mechanisms of action for many biological endpoints may be different at low doses from those observed at high doses; that acute doses <100 mSv may be too small to allow epidemiological detection of excess cancers given the background of naturally occurring cancers.
Journal ArticleDOI
Chronic exposure to low-dose radiation at Chernobyl favours adaptation to oxidative stress in birds
Ismael Galván,Andrea Bonisoli-Alquati,Shanna Jenkinson,Ghanem Elias Ghanem,Kazumasa Wakamatsu,Timothy A. Mousseau,Anders Pape Møller +6 more
TL;DR: These findings represent the first evidence of adaptation to ionizing radiation in wild animals, and confirm that pheomelanin synthesis represents an evolutionary constraint under stressful environmental conditions because it requires GSH consumption.
References
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sources and effects of ionizing radiation
TL;DR: This annex is aimed at providing a sound basis for conclusions regarding the number of significant radiation accidents that have occurred, the corresponding levels of radiation exposures and numbers of deaths and injuries, and the general trends for various practices, in the context of the Committee's overall evaluations of the levels and effects of exposure to ionizing radiation.
Journal ArticleDOI
Induction of tumors in mice by genomic hypomethylation.
François Gaudet,J. Graeme Hodgson,Amir Eden,Laurie Jackson-Grusby,Jessica Dausman,Joe W. Gray,Heinrich Leonhardt,Rudolf Jaenisch +7 more
TL;DR: Results indicate that DNA hypomethylation plays a causal role in tumor formation, possibly by promoting chromosomal instability.
Journal ArticleDOI
Singlet oxygen-mediated damage to proteins and its consequences
TL;DR: This paper reviews the data available on singlet oxygen-mediated protein oxidation and concentrates primarily on the mechanisms by which this excited state species brings about changes to both the side-chains and backbone of amino acids, peptides, and proteins.
Journal ArticleDOI
Adaptive Response of Human Lymphocytes to Low Concentrations of Radioactive Thymidine
TL;DR: When human lymphocytes were cultured with [3H]thymidine, which acts as a source of low-level chronic radiation, and then exposed to 150 rad of x-rays at 5, 7, 9, or 11 hours before fixation, the yield of chromatid aberrations was less than the sum of the yields of aberration induced by [3 H]thcyidine and x-ray separately.