Cytogenetic biodosimetry for radiation accidents in China

Han, Lin; Gao, Yu Tang; Wang, Ping; Lyu, Yumin

doi:10.1016/j.radmp.2020.09.001

Cited by 4 publications

(4 citation statements)

References 31 publications

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“…In most real-life radiation accidents, little will be known about the doses received by the individuals and retrospective dose assessment can be one factor to aid clinical decision making. Biological dosimetry provides a large toolbox of methods to assess whole-or even partial-body doses in the time frame of hours up to years after a potential exposure to ionizing radiation and has proven its usefulness in many cases of accidental exposures to radiation (4)(5)(6)(7)(8)(9)(10)(11)(12). The dicentric chromosome assay (DCA) is still considered as the ''gold standard'' in biological dosimetry and has been continuously improved and validated for several years (13,14).…”

Section: Introductionmentioning

confidence: 99%

RENEB Inter-Laboratory Comparison 2021: The Dicentric Chromosome Assay

et al. 2023

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After large-scale radiation accidents where many individuals are suspected to be exposed to ionizing radiation, biological and physical retrospective dosimetry assays are important tools to aid clinical decision making by categorizing individuals into unexposed/minimally, moderately or highly exposed groups. Quality-controlled inter-laboratory comparisons of simulated accident scenarios are regularly performed in the frame of the European legal association RENEB (Running the European Network of Biological and Physical retrospective Dosimetry) to optimize international networking and emergency readiness in case of large-scale radiation events. In total 33 laboratories from 22 countries around the world participated in the current RENEB inter-laboratory comparison 2021 for the dicentric chromosome assay. Blood was irradiated in vitro with X rays (240 kVp, 13 mA, ∼75 keV, 1 Gy/min) to simulate an acute, homogeneous whole-body exposure. Three blood samples (no. 1: 0 Gy, no. 2: 1.2 Gy, no. 3: 3.5 Gy) were sent to each participant and the task was to culture samples, to prepare slides and to assess radiation doses based on the observed dicentric yields from 50 manually or 150 semi-automatically scored metaphases (triage mode scoring). Approximately two-thirds of the participants applied calibration curves from irradiations with γ rays and about 1/3 from irradiations with X rays with varying energies. The categorization of the samples in clinically relevant groups corresponding to individuals that were unexposed/minimally (0–1 Gy), moderately (1–2 Gy) or highly exposed (>2 Gy) was successfully performed by all participants for sample no. 1 and no. 3 and by ≥74% for sample no. 2. However, while most participants estimated a dose of exactly 0 Gy for the sham-irradiated sample, the precise dose estimates of the samples irradiated with doses >0 Gy were systematically higher than the corresponding reference doses and showed a median deviation of 0.5 Gy (sample no. 2) and 0.95 Gy (sample no. 3) for manual scoring. By converting doses estimated based on γ-ray calibration curves to X-ray doses of a comparable mean photon energy as used in this exercise, the median deviation decreased to 0.27 Gy (sample no. 2) and 0.6 Gy (sample no. 3). The main aim of biological dosimetry in the case of a large-scale event is the categorization of individuals into clinically relevant groups, to aid clinical decision making. This task was successfully performed by all participants for the 0 Gy and 3.5 Gy samples and by 74% (manual scoring) and 80% (semi-automatic scoring) for the 1.2 Gy sample. Due to the accuracy of the dicentric chromosome assay and the high number of participating laboratories, a systematic shift of the dose estimates could be revealed. Differences in radiation quality (X ray vs. γ ray) between the test samples and the applied dose effect curves can partly explain the systematic shift. There might be several additional reasons for the observed bias (e.g., donor effects, transport, experimental conditions or the irradiation setup) and the analysis of these reasons provides great opportunities for future research. The participation of laboratories from countries around the world gave the opportunity to compare the results on an international level.

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Section: Introductionmentioning

confidence: 99%

RENEB Inter-Laboratory Comparison 2021: The Dicentric Chromosome Assay

et al. 2023

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“…It may lead to accumulation of mutations, cell death and carcinogenesis, if not repaired and/or mis-repaired. Conventional techniques such as chromosomal aberration analysis, micronuclei, premature chromosome condensation, pulsed field electrophoresis and comet assays are used to detect DNA damage in cells exposed to IR [ 17 ]. γH2AX assay is considered as one of the most sensitive methods to measure DNA damage such as DNA DSBs for radiation exposure.…”

Section: Introductionmentioning

confidence: 99%

Non-linear dose response of DNA double strand breaks in response to chronic low dose radiation in individuals from high level natural radiation areas of Kerala coast

et al. 2023

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Background The human population living in high level natural radiation areas (HLNRAs) of Kerala coast provide unique opportunities to study the biological effects of low dose and low dose rate ionizing radiation below 100 mGy. The level of radiation in this area varies from < 1.0 to 45 mGy/year. The areas with ≤ 1.50 mGy/year are considered as normal level natural radiation areas (NLNRA) and > 1.50 mGy/year, as high level natural radiation areas (HLNRA). The present study evaluated dose response relationship between DNA double strand breaks (DSBs) and background radiation dose in individuals residing in Kerala coast. Venous blood samples were collected from 200 individuals belonging to NLNRA (n = 50) and four dose groups of HLNRA; 1.51-5.0 mGy/year (n = 50), 5.01-10.0 mGy/year (n = 30), 10.01-15.0 mGy/year (n = 33), > 15.0 mGy/year (n = 37) with written informed consent. The mean dose of NLNRA and four HLNRA dose groups studied are 1.21 ± 0.21 (range: 0.57–1.49), 3.02 ± 0.95 (range: 1.57–4.93), 7.43 ± 1.48 (range: 5.01–9.75), 12.22 ± 1.47 (range: 10.21–14.99), 21.64 ± 6.28 (range: 15.26–39.88) mGy/year, respectively. DNA DSBs were quantified using γH2AX as a marker, where foci were counted per cell using fluorescence microscopy. Results Our results revealed that the frequency of γH2AX foci per cell was 0.090 ± 0.051 and 0.096 ± 0.051, respectively in NLNRA and HLNRA individuals, which were not significantly different (t198 = 0.33; P = 0.739). The frequency of γH2AX foci was observed to be 0.090 ± 0.051, 0.096 ± 0.051, 0.076 ± 0.036, 0.087 ± 0.042, 0.108 ± 0.046 per cell, respectively in different dose groups of ≤ 1.50, 1.51-5.0, 5.01-10.0, 10.01-15.0, > 15.0mGy/year (ANOVA, F4,195 = 2.18, P = 0.072) and suggested non-linearity in dose response. The frequency of γH2AX foci was observed to be 0.098 ± 0.042, 0.078 ± 0.037, 0.084 ± 0.042, 0.099 ± 0.058, 0.097 ± 0.06 and 0.114 ± 0.033 per cell in the age groups of ≤ 29, 30–34, 35–39, 40–44, 45–49 and ≥ 50 years, respectively (ANOVA, F5,194 = 2.17, P = 0.059), which suggested marginal influence of age on the baseline of DSBs. Personal habits such as smoking (No v/s Yes: 0.092 ± 0.047 v/s 0.093 ± 0.048, t198 = 0.13; P = 0.895) and drinking alcohol (No v/s Yes: 0.096 ± 0.052 v/s 0.091 ± 0.045, t198 = 0.62; P = 0.538) did not show any influence on DSBs in the population. Conclusion The present study did not show any increase in DSBs in different dose groups of HLNRA compared to NLNRA, however, it suggested a non-linear dose response between DNA DSBs and chronic low dose radiation.

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“…Biological dosimetry (biodosimetry) is defined as the process of estimating the radiation dose received by an individual during accidental exposure using a biological marker (Perumal et al 2015;Herate and Sabatier 2020). Among many methods of the biological assay in biodosimetry, scoring of the dicentric chromosomes (DC) in peripheral blood lymphocytes (PBL) is considered a reliable and sensitive method due to the specificity for ionizing radiation and the low background frequency of DC in PBL (Mayakannan et al 2018;Han et al 2020;Pujol-Canadell et al 2020). Dicentric chromosomes, defined as chromosomes with two centromeres, are formed from the fusion of two chromosome segments (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

“…The harvest process, consisting of hypotonic treatment and fixation, is performed after culture. Slide preparation and staining of the metaphase chromosomes with Giemsa follow the harvest process (Han et al 2020;Xiao et al 2020). Unstable chromosome aberrations (CAs) such as DC, ring chromosomes (R), and acentric fragment (AF) chromosomes can be scored for dose estimation within a few days after irradiation.…”

Section: Introductionmentioning

confidence: 99%

Effects of carbon dioxide purities on mitotic index in lymphocyte culture and metaphase chromosome quality

et al. 2021

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Abstract. Purnami S, Wibisari IP, Suvifan VA, Nurhayati S, Ramadhani D. 2021. Effects of carbon dioxide purities on mitotic index in lymphocyte culture and metaphase chromosome quality. Nusantara Bioscience 13: 171-176. The metaphase chromosome spread quality is necessary for a faster individual dose prediction following radiological accidents using dicentric chromosome assay. It is well known that the low-quality metaphase chromosome spreads can lead to false positives of dicentric chromosome identification. Thus, evaluation of the main variable that influences the preparation of high-quality metaphase chromosome spreads is important to perform. Until now, no studies have assessed the effects of CO2 purities on metaphase chromosome spread quality. This study aimed to evaluate the effects of carbon dioxide (CO2) purities on lymphocyte proliferation, and the quality of metaphase chromosome spreads to improve the chromosome aberration assay for cytogenetic biodosimetry purposes. Whole blood samples from three different subjects were cultured and incubated for 48 hours with two different grades of CO2 (high purity and food grades) and without CO2. The mitotic index (MI) from each subject was assessed, and the quality of metaphase chromosome spreads was evaluated by comparing the lengths of chromosomes 1, 2, and 21. Statistical analysis revealed that the difference between manual and automatic MI under three different conditions of CO2 purity was not statistically significant (p = 0.162; p = 0.901). Comparative analysis of the lengths of chromosomes 1, 2, and 21 from 145 metaphases also showed a difference that was not statistically significant (p = 0.745; p = 0.915; p = 0.399). Overall, our findings suggest that CO2 purities do not impair lymphocyte proliferation or metaphase quality. Further investigation should include other technical improvements such as drop-slide optimization.

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Cytogenetic biodosimetry for radiation accidents in China

Cited by 4 publications

References 31 publications

RENEB Inter-Laboratory Comparison 2021: The Dicentric Chromosome Assay

RENEB Inter-Laboratory Comparison 2021: The Dicentric Chromosome Assay

Non-linear dose response of DNA double strand breaks in response to chronic low dose radiation in individuals from high level natural radiation areas of Kerala coast

Effects of carbon dioxide purities on mitotic index in lymphocyte culture and metaphase chromosome quality

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