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Płódowska M, Lopez-Riego M, Akuwudike P, Sobota D, Filipek M, Kłosowski M, Kaźmierczak U, Brzozowska B, Baliga A, Lisowska H, Braziewicz J, Olko P, Lundholm L, Wojcik A. Small is beautiful: low activity alpha and gamma sources for small-scale radiation protection research experiments. Int J Radiat Biol 2021; 97:541-552. [PMID: 33395328 DOI: 10.1080/09553002.2021.1867925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 12/11/2020] [Accepted: 12/18/2020] [Indexed: 10/22/2022]
Abstract
PURPOSE Uncertainties regarding the magnitude of health effects following exposure to low doses of ionizing radiation remain a matter of concern both for professionals and for the public. There is consensus within the international radiation research community that more research is required on biological effects of radiation doses below 100 mGy applied at low dose rates. Moreover, there is a demand for increasing education and training of future radiation researchers and regulators. Research, education and training is primarily carried out at universities but university-based radiation research is often hampered by limited access to radiation sources. The aim of the present report is to describe small and cost-effective low activity gamma and alpha sources that can easily be installed and used in university laboratories. METHODS AND RESULTS A gamma radiation source was made from an euxenite-(Y) rock (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6) that was found in an abandoned mine in Sweden. It allows exposing cells grown in culture dishes to radiation at a dose rate of 50 µGy/h and lower. Three alpha sources were custom-made and yield a dose rate of 1 mGy/h each. The construction, dosimetry and cellular effects of the sources are described. CONCLUSIONS We hope that the report will stimulate research and training activities in the low dose field by facilitating access to radiation sources.
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Affiliation(s)
| | - Milagrosa Lopez-Riego
- Centre for Radiation Protection Research, Department of Molecular Biosciences, the Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Pamela Akuwudike
- Centre for Radiation Protection Research, Department of Molecular Biosciences, the Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Daniel Sobota
- Institute of Physics, Jan Kochanowski University, Kielce, Poland
| | - Mateusz Filipek
- Institute of Experimental Physics, University of Warsaw, Warszawa, Poland
- Heavy Ion Laboratory, University of Warsaw, Warszawa, Poland
| | - Mariusz Kłosowski
- Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland
| | | | - Beata Brzozowska
- Institute of Experimental Physics, University of Warsaw, Warszawa, Poland
| | - Agnieszka Baliga
- Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | - Halina Lisowska
- Institute of Biology, Jan Kochanowski University, Kielce, Poland
| | | | - Paweł Olko
- Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland
| | - Lovisa Lundholm
- Centre for Radiation Protection Research, Department of Molecular Biosciences, the Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Andrzej Wojcik
- Institute of Biology, Jan Kochanowski University, Kielce, Poland
- Centre for Radiation Protection Research, Department of Molecular Biosciences, the Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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Variation of 4 MV X-ray dose rate strongly impacts biological response both in vitro and in vivo. Sci Rep 2020; 10:7021. [PMID: 32341396 PMCID: PMC7184727 DOI: 10.1038/s41598-020-64067-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 04/10/2020] [Indexed: 01/10/2023] Open
Abstract
Whereas an RBE > 1 is described for very low-energy X-ray beams (in the range of 25–50 kV), there is a consensus that the RBE of X-rays (from 0.1 to 3 MeV) is equal to 1, whatever the energy or dose rate of the beam. Comparisons of X-ray beam dose rates are scarce even though these beams are widely used in medical diagnosis or radiotherapy. By using two dose rates (0.63 and 2.5 Gy.min−1) of high-energy X-rays on normal endothelial cells (HUVECs), we have studied the clonogenic assay, but also viability/mortality, cell cycle analysis and measured cellular senescence by flow cytometry, and have performed gene analysis on custom arrays. In order to consolidate these data, we performed localized irradiation of exteriorized small intestine at 0.63 and 2.5 Gy.min−1. Interestingly, in vivo validation has shown a significantly higher loss of weight at the higher dose when irradiating to 19 Gy a small fragment of exteriorized small intestine of C57Bl6J mice. Nevertheless, no significant differences were observed in lesioned scores between the two dose rates, while bordering epithelium staining indicated twofold greater severe damage at 2.5 Gy.min−1 compared to 0.63 Gy.min−1 at one week post-irradiation. Taken together, these experiments systematically show that the relative biological effectiveness of photons is different from 1 when varying the dose rate of high-energy X-rays. Moreover, these results strongly suggest that, in support of clonogenic assay, multiparametric analysis should be considered to provide an accurate evaluation of the outcome of irradiated cells.
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Live Dynamics of 53BP1 Foci Following Simultaneous Induction of Clustered and Dispersed DNA Damage in U2OS Cells. Int J Mol Sci 2018; 19:ijms19020519. [PMID: 29419809 PMCID: PMC5855741 DOI: 10.3390/ijms19020519] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 01/18/2018] [Accepted: 01/30/2018] [Indexed: 12/19/2022] Open
Abstract
Cells react differently to clustered and dispersed DNA double strand breaks (DSB). Little is known about the initial reaction to simultaneous induction of DSBs with different complexities. Here, we used live cell microscopy to analyse the behaviour of 53BP1-GFP (green fluorescence protein) foci formation at DSBs induced in U2OS cells by alpha particles, X-rays or mixed beams over a 75 min period post irradiation. X-ray-induced foci rapidly increased and declined over the observation interval. After an initial increase, mixed beam-induced foci remained at a constant level over the observation interval, similarly as alpha-induced foci. The average areas of radiation-induced foci were similar for mixed beams and X-rays, being significantly smaller than those induced by alpha particles. Pixel intensities were highest for mixed beam-induced foci and showed the lowest level of variability over time as compared to foci induced by alphas and X-rays alone. Finally, mixed beam-exposed foci showed the lowest level of mobility as compared to alpha and X-ray exposure. The results suggest paralysation of chromatin around foci containing clustered DNA damage.
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Sollazzo A, Brzozowska B, Cheng L, Lundholm L, Haghdoost S, Scherthan H, Wojcik A. Alpha Particles and X Rays Interact in Inducing DNA Damage in U2OS Cells. Radiat Res 2017; 188:400-411. [DOI: 10.1667/rr14803.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Alice Sollazzo
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Beata Brzozowska
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Lei Cheng
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Lovisa Lundholm
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Siamak Haghdoost
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Harry Scherthan
- Bundeswehr Institute of Radiobiology, D-80937 Munich, Germany
| | - Andrzej Wojcik
- Centre for Radiation Protection Research, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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Sollazzo A, Shakeri-Manesh S, Fotouhi A, Czub J, Haghdoost S, Wojcik A. Interaction of low and high LET radiation in TK6 cells-mechanistic aspects and significance for radiation protection. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2016; 36:721-735. [PMID: 27631423 DOI: 10.1088/0952-4746/36/4/721] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Most environmental, occupational and medical exposures to ionising radiation are associated with a simultaneous action of different radiation types. An open question remains whether radiations of different qualities interact with each other to yield effects stronger than expected based on the assumption of additivity. It is possible that DNA damage induced by high linear energy transfer (LET) radiation will lead to an opening of the chromatin structure making the DNA more susceptible to attack by reactive oxygen species (ROS) generated by the low LET radiation. In such case, the effect of mixed beams should be strongly expressed in cells that are sensitive to ROS. The present investigation was carried out to test if cells with an impaired capacity to handle oxidative stress are particularly sensitive to the effect of mixed beams of alpha particles and x-rays. Clonogenic cell survival curves and mutant frequencies were analysed in TK6 wild type (wt) cells and in TK6 cells with a knocked down hMYH glycosylase. The results showed a synergistic effect of mixed beams on clonogenic cell survival of TK6wt but not TK6MYH- cells. The frequencies of mutants showed a high degree of interexperimental variability without any indications for synergistic effects of mixed beams. TK6MYH- cells were generally more tolerant to radiation exposure with respect to clonogenic cell survival but showed a strong increase in mutant frequency. The results demonstrate that exposure of wt cells to a mixed beam of alpha particles and x-rays leads to a detrimental effect which is stronger than expected based on the assumption of additivity. The role of oxidative stress in the reaction of cells to mixed beams remains unclear.
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Affiliation(s)
- Alice Sollazzo
- MBW Department, Centre for Radiation Protection Research, Stockholm University, Sweden
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Brehwens K, Bajinskis A, Haghdoost S, Wojcik A. Micronucleus frequencies and clonogenic cell survival in TK6 cells exposed to changing dose rates under controlled temperature conditions. Int J Radiat Biol 2013; 90:241-7. [PMID: 24350915 DOI: 10.3109/09553002.2014.873831] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE In most exposure scenarios the dose rate of exposure is not constant. Despite this, very little information exists on the possible biological effects of exposing cells to radiation under the conditions of a changing dose rate. The current study highlights interesting effects following exposure under these conditions. MATERIALS AND METHODS We constructed a new exposure facility that allows exposing cells inside an incubator and used it to irradiate human lymphoblastoid TK6 cells both after a moderate (0.48 Gy) and a high (1.1 Gy) dose, where the change in dose rate was, respectively, ≈ 17-fold (2.2-37 mGy/min) and ≈ 39-fold (2.7-106 mGy/min). Clonogenic survival and micronuclei (MN) induction were the chosen endpoints. RESULTS The obtained results confirm the outcome of our first study that TK6 cells exposed to a decreasing dose rate express more MN than cells exposed to an increasing or constant dose rate. The effect was not seen after the moderate dose of 0.48 Gy or detectable at the level of clonogenic cell survival. CONCLUSIONS We speculate that the high level of MN is probably related to a delayed elimination of damaged cells by interphase death, as opposed to mechanisms relating to DNA damage and repair.
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Affiliation(s)
- Karl Brehwens
- Centre for Radiation Protection Research, Department of Molecular Biosciences, the Wenner-Gren Institute, Stockholm University , Stockholm , Sweden
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Staaf E, Brehwens K, Haghdoost S, Pachnerová-Brabcová K, Czub J, Braziewicz J, Nievaart S, Wojcik A. Characterisation of a setup for mixed beam exposures of cells to 241Am alpha particles and X-rays. RADIATION PROTECTION DOSIMETRY 2012; 151:570-579. [PMID: 22434924 DOI: 10.1093/rpd/ncs024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Exposure of humans to mixed fields of high- and low-linear energy transfer (LET) radiation occurs in many situations-for example, in urban areas with high levels of indoor radon as well as background gamma radiation, during airplane flights or certain forms of radiation therapy. From the perspective of health risk associated with exposure to mixed fields, it is important to understand the interactions between different radiation types. In most cellular investigations on mixed beams, two types of irradiations have been applied sequentially. Simultaneous irradiation is the desirable scenario but requires a dedicated irradiation facility. The authors have constructed a facility where cells can be simultaneously exposed to (241)Am alpha particles and 190-kV X-rays at 37°C. This study presents the technical details and the dosimetry of the setup, as well as validates the performance of the setup for clonogenic survival in AA8 Chinese hamster ovary cells. No significant synergistic effect was observed. The relative biological effectiveness of the alpha particles was 2.56 for 37 % and 1.90 for 10 % clonogenic survival.
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Affiliation(s)
- Elina Staaf
- Centre for Radiation Protection Research, GMT Department, Stockholm University, Svante Arrhenius väg 20C, 106 91 Stockholm, Sweden.
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Staaf E, Brehwens K, Haghdoost S, Nievaart S, Pachnerova-Brabcova K, Czub J, Braziewicz J, Wojcik A. Micronuclei in human peripheral blood lymphocytes exposed to mixed beams of X-rays and alpha particles. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2012; 51:283-293. [PMID: 22526916 DOI: 10.1007/s00411-012-0417-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 04/10/2012] [Indexed: 05/31/2023]
Abstract
The purpose of this study was to analyse the cytogenetic effect of exposing human peripheral blood lymphocytes (PBL) to a mixed beam of alpha particles and X-rays. Whole blood collected from one donor was exposed to different doses of alpha particles ((241)Am), X-rays and a combination of both. All exposures were carried out at 37 °C. Three independent experiments were performed. Micronuclei (MN) in binucleated PBL were scored as the endpoint. Moreover, the size of MN was measured. The results show that exposure of PBL to a mixed beam of high and low linear energy transfer radiation led to significantly higher than expected frequencies of MN. The measurement of MN size did not reveal any differences between the effect of alpha particles and mixed beam. In conclusion, a combined exposure of PBL to alpha particles and X-rays leads to a synergistic effect as measured by the frequency of MN. From the analysis of MN distributions, we conclude that the increase was due to an impaired repair of X-ray-induced DNA damage.
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Affiliation(s)
- Elina Staaf
- Stockholms Universitet, Svante Arrhenius väg 20C, 10691 Stockholm, Sweden
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