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Gajski G, Kašuba V, Milić M, Gerić M, Matković K, Delić L, Nikolić M, Pavičić M, Rozgaj R, Garaj-Vrhovac V, Kopjar N. Exploring cytokinesis block micronucleus assay in Croatia: A journey through the past, present, and future in biomonitoring of the general population. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2024; 895:503749. [PMID: 38575251 DOI: 10.1016/j.mrgentox.2024.503749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/06/2024] [Accepted: 03/12/2024] [Indexed: 04/06/2024]
Abstract
In this study, we used the cytokinesis-block micronucleus (CBMN) assay to evaluate the background frequency of cytogenetic damage in peripheral blood lymphocytes of the general population concerning different anthropometric data and lifestyle factors. The background frequency of CBMN assay parameters was analysed in 850 healthy, occupationally non-exposed male and female subjects (average age, 38±11 years) gathered from the general Croatian population from 2000 to 2023. The mean background values for micronuclei (MNi) in the whole population were 5.3±4.3 per 1000 binucleated cells, while the mean frequency of nucleoplasmic bridges (NPBs) was 0.7±1.3 and of nuclear buds (NBUDs) 3.1±3.2. The cut-off value, which corresponds to the 95th percentile of the distribution of 850 individual values, was 14 MNi, 3 NPBs, and 9 NBUDs. Results from our database also showed an association of the tested genomic instability parameters with age and sex but also with other lifestyle factors. These findings underscore the importance of considering several anthropometric and lifestyle factors when conducting biomonitoring studies. Overall, the normal and cut-off values attained here present normal values for the general population that can later serve as baseline values for further human biomonitoring studies either in Croatia or worldwide.
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Affiliation(s)
- Goran Gajski
- Institute for Medical Research and Occupational Health, Division of Toxicology, Mutagenesis Unit, 10000 Zagreb, Croatia.
| | - Vilena Kašuba
- Institute for Medical Research and Occupational Health, Division of Toxicology, Mutagenesis Unit, 10000 Zagreb, Croatia
| | - Mirta Milić
- Institute for Medical Research and Occupational Health, Division of Toxicology, Mutagenesis Unit, 10000 Zagreb, Croatia
| | - Marko Gerić
- Institute for Medical Research and Occupational Health, Division of Toxicology, Mutagenesis Unit, 10000 Zagreb, Croatia
| | - Katarina Matković
- Institute for Medical Research and Occupational Health, Division of Toxicology, Mutagenesis Unit, 10000 Zagreb, Croatia
| | - Luka Delić
- Institute for Medical Research and Occupational Health, Division of Toxicology, Mutagenesis Unit, 10000 Zagreb, Croatia
| | - Maja Nikolić
- Institute for Medical Research and Occupational Health, Division of Toxicology, Mutagenesis Unit, 10000 Zagreb, Croatia
| | - Martina Pavičić
- Institute for Medical Research and Occupational Health, Division of Toxicology, Mutagenesis Unit, 10000 Zagreb, Croatia
| | - Ružica Rozgaj
- Institute for Medical Research and Occupational Health, Division of Toxicology, Mutagenesis Unit, 10000 Zagreb, Croatia
| | - Vera Garaj-Vrhovac
- Institute for Medical Research and Occupational Health, Division of Toxicology, Mutagenesis Unit, 10000 Zagreb, Croatia
| | - Nevenka Kopjar
- Institute for Medical Research and Occupational Health, Division of Toxicology, Mutagenesis Unit, 10000 Zagreb, Croatia
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Chaurasia RK, Sapra BK, Aswal DK. Interplay of immune modulation, adaptive response and hormesis: Suggestive of threshold for clinical manifestation of effects of ionizing radiation at low doses? THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170178. [PMID: 38280586 DOI: 10.1016/j.scitotenv.2024.170178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 12/26/2023] [Accepted: 01/13/2024] [Indexed: 01/29/2024]
Abstract
The health impacts of low-dose ionizing radiation exposures have been a subject of debate over the last three to four decades. While there has been enough evidence of "no adverse observable" health effects at low doses and low dose rates, the hypothesis of "Linear No Threshold" continues to rule and govern the principles of radiation protection and the formulation of regulations and public policies. In adopting this conservative approach, the role of the biological processes underway in the human body is kept at abeyance. This review consolidates the available studies that discuss all related biological pathways and repair mechanisms that inhibit the progression of deleterious effects at low doses and low dose rates of ionizing radiation. It is pertinent that, taking cognizance of these processes, there is a need to have a relook at policies of radiation protection, which as of now are too stringent, leading to undue economic losses and negative public perception about radiation.
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Affiliation(s)
- R K Chaurasia
- Radiological Physics and Advisory Division, India; Health, Safety and Environment Group,Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Mumbai 400094, India.
| | - B K Sapra
- Radiological Physics and Advisory Division, India; Health, Safety and Environment Group,Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Mumbai 400094, India.
| | - D K Aswal
- Health, Safety and Environment Group,Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Mumbai 400094, India.
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Jain V, Saini D, Soren DC, Kumar VA, Vivek Kumar PR, Koya PKM, Jaikrishan G, Das B. 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. Genes Environ 2023; 45:16. [PMID: 37127760 PMCID: PMC10150514 DOI: 10.1186/s41021-023-00273-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 04/06/2023] [Indexed: 05/03/2023] Open
Abstract
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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Affiliation(s)
- Vinay Jain
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
- Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai, 400 094, India
| | - Divyalakshmi Saini
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
| | - D C Soren
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
| | - V Anil Kumar
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
| | - P R Vivek Kumar
- Low Level Radiation Research Laboratory, LLRRS, RB&HSD, BSG, BARC, IRE Campus, Beach Road, Kollam, Kerala, 691 001, India
- Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai, 400 094, India
| | - P K M Koya
- Low Level Radiation Research Laboratory, LLRRS, RB&HSD, BSG, BARC, IRE Campus, Beach Road, Kollam, Kerala, 691 001, India
| | - G Jaikrishan
- Low Level Radiation Research Laboratory, LLRRS, RB&HSD, BSG, BARC, IRE Campus, Beach Road, Kollam, Kerala, 691 001, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India.
- Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai, 400 094, India.
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Saini D, Jain V, Das B. Evaluation of natural chronic low dose radiation exposure on telomere length and transcriptional response of shelterin complex in individuals residing in Kerala coast, India. Mutat Res 2022; 825:111797. [PMID: 36116241 DOI: 10.1016/j.mrfmmm.2022.111797] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/16/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
The high level natural radiation areas (HLNRA) of Kerala coast provide unique opportunity to study the biological effect of chronic low dose ionizing radiation (LDIR) on human population below 100 mSv. The radiation level in this area varies from < 1.0-45 mGy /year due to patchy distribution of monazite in the sand, which contains 232Th (8-10%), 238U (0.3%), and their decay products. Telomere length attrition has been correlated to DNA damage due to genotoxic agents. The objective of the present study is to evaluate the effect of natural chronic LDIR exposure on telomere length and transcriptional response of telomere specific and DNA damage repair genes in peripheral blood mononuclear cells (PBMCs) of individuals from normal level natural radiation areas (NLNRA) and HLNRA of Kerala coast, southwest India. Blood samples were collected from 71 random male donors (24-80 years) from NLNRA (≤1.50 mGy/year; N = 19) and two HLNRA dose groups [1.51-10 mGy/year (N = 17); > 10 mGy/year, (N = 35)]. Genomic DNA was isolated from PBMCs and relative telomere length (RTL) was determined using real time q-PCR. Radio-adaptive response (RAR) study was carried out in PBMCs of 40 random males from NLNRA (N = 20) and HLNRA (>10 mGy/year; N = 20), where PBMCs were given a challenged dose of 2.0 Gy gamma radiation at 4 h. Transcriptional profile of telomere specific (TRF1, TRF2, POT1, TIN2, TPP1, RAP1), DNA damage response (RAD17, ATM, CHEK1) and base excision repair pathway (BER) (OGG1, XRCC1, NTH1, NEIL1, MUTYH, MBD4) genes were analysed at basal level and after a challenge dose of 2.0 Gy at 4 h. Our results did not show any significant effect of chronic LDR on RTL among the individuals from NLNRA and two HLNRA groups (p = 0.195). However, influence of age on RTL was clearly evident among NLNRA and HLNRA individuals. At basal level, TRF1, TRF2, TIN2, MBD4, NEIL1 and RAD17 showed significant up-regulation, whereas XRCC1 was significantly down regulated in HLNRA individuals. After a challenge dose of 2.0 Gy, significant transcriptional up-regulation was observed at telomere specific (TRF2, POT1) and BER (MBD4, NEIL1) genes in HLNRA individuals as compared to NLNRA suggesting their role in RAR. In conclusion, elevated level of natural chronic LDR exposure did not have any adverse effect on telomere length in Kerala coast. Significant transcriptional response at TRF2, MBD4 and NEIL1 at basal level and with a challenge dose of 2.0 Gy suggested their active involvement in efficient repair and telomere maintenance in individuals from HLNRA of Kerala coast.
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Affiliation(s)
- Divyalakshmi Saini
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India; Mumbai University, Fort Mumbai, India
| | - Vinay Jain
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India; Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai 400 094, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India; Mumbai University, Fort Mumbai, India; Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai 400 094, India.
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Ghosh A. Biological and cellular responses of humans to high-level natural radiation: A clarion call for a fresh perspective on the linear no-threshold paradigm. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 878:503478. [PMID: 35649671 DOI: 10.1016/j.mrgentox.2022.503478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/04/2022] [Accepted: 03/04/2022] [Indexed: 06/15/2023]
Abstract
There remains considerable uncertainty in obtaining risk estimates of adverse health outcomes of chronic low-dose radiation. In the absence of reliable direct data, extrapolation through the linear no-threshold (LNT) hypothesis forms the cardinal tenet of all risk assessments for low doses (≤ 100 mGy) and for the radiation protection principle of As Low As Reasonably Achievable (ALARA). However, as recent evidences demonstrate, LNT assumptions do not appropriately reflect the biology of the cell at the low-dose end of the dose-response curve. In this regard, human populations living in high-level natural radiation areas (HLNRA) of the world can provide valuable insights into the biological and cellular effects of chronic radiation to facilitate improved precision of the dose-response relationship at low doses. Here, data obtained over decades of epidemiological and radiobiological studies on HLNRA populations is summarized. These studies do not show any evidence of unfavourable health effects or adverse cellular effects that can be correlated with high-level natural radiation. Contrary to the assumptions of LNT, no excess cancer risks or untoward pregnancy outcomes have been found to be associated with cumulative radiation dose or in-utero exposures. Molecular biology-driven studies demonstrate that chronic low-dose activates several cellular defence mechanisms that help cells to sense, recover, survive, and adapt to radiation stress. These mechanisms include stress-response signaling, DNA repair, immune alterations and most importantly, the radiation-induced adaptive response. The HLNRA data is consistent with the new evolving paradigms of low-dose radiobiology and can help develop the theoretical framework of an alternate dose-response model. A rational integration of radiobiology with epidemiology data is imperative to reduce uncertainties in predicting the potential health risks of chronic low doses of radiation.
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Affiliation(s)
- Anu Ghosh
- Animal House Facility & Radiation Signaling Section, Radiation Biology & Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai 400 085, India; Homi Bhabha National Institute (HBNI), Anushaktinagar, Mumbai 400 094, India.
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Sudheer KR, Mohammad Koya PK, Prakash AJ, Prakash AM, Manoj Kumar R, Shyni S, Jagadeesan CK, Jaikrishan G, Das B. Evaluation of risk due to chronic low dose ionizing radiation exposure on the birth prevalence of congenital heart diseases (CHD) among the newborns from high-level natural radiation areas of Kerala coast, India. Genes Environ 2022; 44:1. [PMID: 34983691 PMCID: PMC8725549 DOI: 10.1186/s41021-021-00231-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 12/07/2021] [Indexed: 02/07/2023] Open
Abstract
Background The human population residing in monazite bearing Kerala coast are exposed to chronic low dose and low dose rate external gamma radiation due to Th232 deposits in its beach sand. The radiation level in this area varies from < 1.0 to 45.0 mGy/year. This area serves as an ideal source for conducting large-scale epidemiological studies for assessing risk of low dose and low dose rate radiation exposure on human population. The areas with a dose level of ≤1.50 mGy/year are considered as normal level natural radiation areas (NLNRAs) and areas with > 1.50 mGy/year, as high level natural radiation areas (HLNRAs). HLNRAs were further stratified into three dose groups of 1.51-3.0 mGy/year, 3.01-6.00 mGy/year and > 6.0 mGy/year. The present study evaluates the effects of chronic low dose radiation (LDR) exposure on the birth prevalence of Congenital Heart Diseases (CHD) among the live newborns monitored in hospital based prospective study from NLNRAs and HLNRAs of Kerala coast, India. Methodology Consecutive newborns were monitored from two hospital units located in the study area for congenital malformations. Referred CHD cases among the newborns screened were confirmed by conducting investigations such as pulse oximetry, chest X-ray, electrocardiogram and echocardiogram etc. Results Among the newborns screened, 289 CHDs were identified with a frequency of 1.49‰ among 193,634 livebirths, which constituted 6.03% of overall malformations and 16.29% of major malformations. Multiple logistic regression analysis suggested that the risk of CHD among the newborns of mothers from HLNRAs with a dose group of 1.51-3.0 mGy/year was significantly lower as compared to NLNRA (OR = 0.72, 95% CI: 0.57-0.92), whereas it was similar in HLNRA dose groups of 3.01-6.00 mGy/year (OR = 0.55, 95% CI: 0.31-1.00) and ≥ 6.0 mGy/year (OR = 0.96, 95% CI: 0.50-1.85). The frequency of CHDs did not show any radiation dose related increasing trend. However, a significant (P = 0.005) reduction was observed in the birth prevalence of CHDs among the newborns from HLNRA (1.28‰) as compared to NLNRA (1.79‰). Conclusion Chronic LDR exposure did not show any increased risk on the birth prevalence of CHDs from high-level natural radiation areas of Kerala coast, India. No linear increasing trend was observed with respect to different background dose groups. The frequency of CHD was observed to be 1.49 per 1000 livebirths, which was similar to the frequency of severe CHD rate reported elsewhere in India and was much less than the reported frequency of 9 per thousand.
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Affiliation(s)
- K R Sudheer
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group (BSG), Bhabha Atomic Research Centre (BARC), Beach Road, Kollam, Kerala, 691 001, India
| | - P K Mohammad Koya
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group (BSG), Bhabha Atomic Research Centre (BARC), Beach Road, Kollam, Kerala, 691 001, India
| | - Anu J Prakash
- Department of Paediatrics, Victoria Hospital, Kollam, 691 001, India
| | - Ambily M Prakash
- Department of Gynaecology, Victoria Hospital, Kollam, 691 001, India
| | - R Manoj Kumar
- Department of Paediatrics, Taluk Head Quarters Hospital, Karunagapally, 690 544, India
| | - S Shyni
- Department of Gynaecology, Taluk Head Quarters Hospital, Karunagapally, 690 544, India
| | - C K Jagadeesan
- Directorate of Health Services, Government of Kerala, Thiruvananthapuram, 695 011, India
| | - G Jaikrishan
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group (BSG), Bhabha Atomic Research Centre (BARC), Beach Road, Kollam, Kerala, 691 001, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section (LLRRS), Homi Bhabha National Institute (HBNI), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group (BSG), Bhabha Atomic Research Centre (BARC), Mumbai, 400 085, India. .,Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400 094, India.
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Chronic exposure of humans to high level natural background radiation leads to robust expression of protective stress response proteins. Sci Rep 2021; 11:1777. [PMID: 33469066 PMCID: PMC7815775 DOI: 10.1038/s41598-020-80405-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 12/21/2020] [Indexed: 12/13/2022] Open
Abstract
Understanding exposures to low doses of ionizing radiation are relevant since most environmental, diagnostic radiology and occupational exposures lie in this region. However, the molecular mechanisms that drive cellular responses at these doses, and the subsequent health outcomes, remain unclear. A local monazite-rich high level natural radiation area (HLNRA) in the state of Kerala on the south-west coast of Indian subcontinent show radiation doses extending from ≤ 1 to ≥ 45 mGy/y and thus, serve as a model resource to understand low dose mechanisms directly on healthy humans. We performed quantitative discovery proteomics based on multiplexed isobaric tags (iTRAQ) coupled with LC–MS/MS on human peripheral blood mononuclear cells from HLNRA individuals. Several proteins involved in diverse biological processes such as DNA repair, RNA processing, chromatin modifications and cytoskeletal organization showed distinct expression in HLNRA individuals, suggestive of both recovery and adaptation to low dose radiation. In protein–protein interaction (PPI) networks, YWHAZ (14-3-3ζ) emerged as the top-most hub protein that may direct phosphorylation driven pro-survival cellular processes against radiation stress. PPI networks also identified an integral role for the cytoskeletal protein ACTB, signaling protein PRKACA; and the molecular chaperone HSPA8. The data will allow better integration of radiation biology and epidemiology for risk assessment [Data are available via ProteomeXchange with identifier PXD022380].
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S M J M, Gh M, S A R M, M P. Is Induction of Anomalies in Lymphocytes of the Residents of High Background Radiation Areas Associated with Increased Cancer Risk? J Biomed Phys Eng 2019; 9:367-372. [PMID: 31341882 PMCID: PMC6613150 DOI: 10.31661/jbpe.v9i3jun.654] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Accepted: 12/08/2016] [Indexed: 11/16/2022]
Abstract
Man has been exposed to different levels of natural background radiation since the creation of human life. There are inhabited areas around the world with extraordinary levels of natural background radiation. The level of natural radiation in these areas is up to two orders of magnitude higher than other places. Areas such as Yangjiang, China; Guarapari, Brazil; and Kerala, India are among the areas with high levels of natural radiation. Ramsar a coastal city in North Iran has some inhabited areas with the highest known levels of background radiation around the world. People who live in high background radiation areas (HBRAs) such as Ramsar do not record any detrimental biological effects. While some cytogenetic studies conducted in HBRAs have shown increased frequencies of unstable chromosome aberration, other investigations failed to find a significant difference. This short review is an attempt to verify if induction of chromosomal anomalies in the lymphocytes of the residents of high background radiation areas is associated with increased cancer risk.
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Affiliation(s)
- Mortazavi S M J
- Professor of Medical Physics, Medical Physics Department, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mortazavi Gh
- Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mortazavi S A R
- Student of Research Committee, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Paknahad M
- Oral and Dental Disease Research Center, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
- Assistant Professor of Oral and Maxillofacial Radiology, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
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C V K, E N R, V AK, P R VK, P K M K, G J, Das B. Frequency of chromosome aberrations among adult male individuals from high and normal level natural radiation areas of Kerala in the southwest coast of India. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2018; 828:23-29. [PMID: 29555061 DOI: 10.1016/j.mrgentox.2018.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 01/15/2018] [Accepted: 02/07/2018] [Indexed: 12/20/2022]
Abstract
Chromosome aberration analysis was carried out in peripheral blood lymphocytes of adult male individuals from normal level natural radiation areas (NLNRA, ≤1.5 mGy/year, N = 27) and high level natural radiation areas (HLNRA, >1.5mGy/year, N = 70) of Kerala coast in southwest India. The mean age of individuals from NLNRA and HLNRA was 40.9 ± 9.4 and 43.7 ± 12.4 years, respectively, with an overall mean of 42.9 ± 11.6 (range: 18-80). Whole-blood cultures were set up and about 260 metaphases were scored per individual. The frequency of chromosome aberrations was calculated per 1000 cells. The overall basal frequency of unstable (dicentrics and rings), stable (translocations and inversions) and other (fragments and breaks) aberrations was 1.54 ± 0.25, 4.1 ± 0.40 and 6.66 ± 0.51, respectively. Individuals of NLNRA and HLNRA had statistically similar frequency of unstable (2.11 ± 0.64 v/s 1.39 ± 0.26; RR = 0.66; 95% CI: 0.33-1.33), stable (4.60 ± 0.94 v/s 3.97 ± 0.44; RR = 0.86; 95% CI: 0.55-1.36) and other (7.85 ± 1.23 v/s 6.36 ± 0.56; RR = 0.81; 95% CI: 0.57-1.15) chromosome aberrations. Frequencies of unstable, stable and other chromosome aberrations did not show any dose response after stratification of HLNRA samples into three dose groups (1.51-5.0 mGy/year, 5.01-10 mGy/year and >10.0 mGy/year). Smokers showed an increase in other chromosome aberrations (P < 0.001), but smoking was not associated with unstable and stable aberrations. Alcohol consumption and tobacco chewing had no significant association with any type of chromosome aberrations. In conclusion, chronic low dose radiation prevailing in Kerala coast did not show any significant effect on the basal frequency of chromosome aberrations among the adult population.
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Affiliation(s)
- Karuppasamy C V
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group (BSG), Bhabha Atomic Research Centre (BARC), Kollam 691 001, Kerala, India.
| | - Ramachandran E N
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group (BSG), Bhabha Atomic Research Centre (BARC), Kollam 691 001, Kerala, India
| | - Anil Kumar V
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group (BSG), Bhabha Atomic Research Centre (BARC), Kollam 691 001, Kerala, India
| | - Vivek Kumar P R
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group (BSG), Bhabha Atomic Research Centre (BARC), Kollam 691 001, Kerala, India
| | - Koya P K M
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group (BSG), Bhabha Atomic Research Centre (BARC), Kollam 691 001, Kerala, India
| | - Jaikrishan G
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group (BSG), Bhabha Atomic Research Centre (BARC), Kollam 691 001, Kerala, India
| | - Birajalaxmi Das
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group (BSG), Bhabha Atomic Research Centre (BARC), Kollam 691 001, Kerala, India; LLRRS, RB & HSD, BSG, BARC, Trombay, Mumbai 400 085, India.
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10
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Jain V, Das B. Global transcriptome profile reveals abundance of DNA damage response and repair genes in individuals from high level natural radiation areas of Kerala coast. PLoS One 2017; 12:e0187274. [PMID: 29161272 PMCID: PMC5697823 DOI: 10.1371/journal.pone.0187274] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 10/17/2017] [Indexed: 12/26/2022] Open
Abstract
The high level natural radiation areas (HLNRA) of Kerala coast in south west India is unique for its wide variation in the background radiation dose (<1.0mGy to 45mGy/year) and vast population size. Several biological studies conducted in this area did not reveal any adverse effects of chronic low dose and low dose rate radiation on human population. In the present study, global transcriptome analysis was carried out in peripheral blood mono-nuclear cells of 36 individuals belonging to different background dose groups [NLNRA, (Group I, ≤1.50 mGy/year) and three groups of HLNRA; Group II, 1.51–5.0 mGy/year), Group III, 5.01-15mGy/year and Group IV, >15.0 mGy/year] to find out differentially expressed genes and their biological significance in response to chronic low dose radiation exposure. Our results revealed a dose dependent increase in the number of differentially expressed genes with respect to different background dose levels. Gene ontology analysis revealed majority of these differentially expressed genes are involved in DNA damage response (DDR) signaling, DNA repair, cell cycle arrest, apoptosis, histone/chromatin modification and immune response. In the present study, 64 background dose responsive genes have been identified as possible chronic low dose radiation signatures. Validation of 30 differentially expressed genes was carried out using fluorescent based universal probe library. Abundance of DDR and DNA repair genes along with pathways such as MAPK, p53 and JNK in higher background dose groups (> 5.0mGy/year) indicated a possible threshold dose for DDR signaling and are plausible reason of observing in vivo radio-adaptive response and non-carcinogenesis in HLNRA population. To our knowledge, this is the first study on molecular effect of chronic low dose radiation exposure on human population from high background radiation areas at transcriptome level using high throughput approach. These findings have tremendous implications in understanding low dose radiation biology especially, the effect of low dose radiation exposure in humans.
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Affiliation(s)
- Vinay Jain
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Trombay, Mumbai, India
- Homi Bhabha National Institute, Anushakti Nagar, Mumbai, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Trombay, Mumbai, India
- Homi Bhabha National Institute, Anushakti Nagar, Mumbai, India
- * E-mail: ,
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11
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Efficient repair of DNA double strand breaks in individuals from high level natural radiation areas of Kerala coast, south-west India. Mutat Res 2017; 806:39-50. [PMID: 28963924 DOI: 10.1016/j.mrfmmm.2017.09.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 08/14/2017] [Accepted: 09/11/2017] [Indexed: 11/21/2022]
Abstract
High level natural radiation areas (HLNRA) of Kerala coastal strip (55km long and 0.5km wide) in southwest India exhibit wide variations in the level of background dose (< 1.0-45.0mGy/year) due to thorium deposits in the beach sand. The areas with ≤1.5mGy/year are considered as normal level natural radiation area (NLNRA), whereas areas with >1.5mGy/year are HLNRA. Individuals belonging to HLNRA were stratified into two groups, Low dose group (LDG: 1.51-5.0mGy/year) and high dose group (HDG: >5.0mGy/year). The mean annual dose received by the individuals from NLNRA, LDG and HDG was 1.3±0.1, 2.7±0.9 and 9.4±2.3mGy/year, respectively. Induction and repair of DNA double strand breaks (DSBs) in terms of gamma-H2AX positive cells were analysed in peripheral blood mononuclear cells (PBMCs) using flow cytometry. Induction of DSBs was studied at low (0.25Gy) and high challenge doses (1.0 and 2.0Gy) of gamma radiation in 78 individuals {NLNRA, N=23; HLNRA (LDG, N=21 and HDG, N=34)}. Repair kinetics of DSBs were evaluated in PBMCs of 30 individuals belonging to NLNRA (N=8), LDG (N=7) and HDG (N=15) at low (0.25Gy) and high doses (2.0Gy) of gamma radiation. Transcription profile of DNA damage response (DDR) and DSB repair genes involved in non-homologous end joining (NHEJ) and homologous recombination repair (HRR) pathways was analysed after a challenge dose of 2.0Gy in PBMCs of NLNRA (N=10) and HDG, HLNRA (N=10) group. Our results revealed significantly lower induction and efficient repair of DSBs in HLNRA groups as compared to NLNRA. Transcription profile of DCLRE1C, XRCC4, NBS1 and CDK2 showed significant up-regulation (p≤0.05) in HDG at a challenge dose of 2.0Gy indicating active involvement of DDR and DSB repair pathways. In conclusion, lower induction and efficient repair of DNA DSBs in HLNRA groups is suggestive of an in vivo radio-adaptive response due to priming effect of chronic low dose radiation prevailing in this area.
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12
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Ramachandran EN, Karuppasamy CV, Kumar VA, Soren DC, Kumar PRV, Koya PKM, Jaikrishan G, Das B. Radio-adaptive response in peripheral blood lymphocytes of individuals residing in high-level natural radiation areas of Kerala in the southwest coast of India. Mutagenesis 2017; 32:267-273. [PMID: 27831478 DOI: 10.1093/mutage/gew057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The present study investigates whether the chronic low-dose radiation exposure induces an in vivo radio-adaptive response in individuals from high-level natural radiation areas (HLNRA) of the Kerala coast. Peripheral blood samples from 54 adult male individuals aged between 26 and 65 years were collected for the study with written informed consent. Each of the whole blood sample was divided into three, one was sham irradiated, second and third was exposed to challenging doses of 1.0 and 2.0 Gy gamma radiation, respectively. Cytokinesis-block micronucleus (CBMN) assay was employed to study the radio-adaptive response. Seventeen individuals were from normal-level natural radiation area (NLNRA ≤1.5 mGy/year) and 37 from HLNRA (> 1.5 mGy/year). Based on the annual dose received, individuals from HLNRA were further classified into low-dose group (LDG, 1.51-5.0 mGy/year, N = 19) and high-dose group (HDG >5.0 mGy/year, N = 18). Basal frequency of micronucleus (MN) was comparable across the three dose groups (NLNRA, LDG and HDG, P = 0.64). Age of the individuals showed a significant effect on the frequency of MN after challenging dose exposures. The mean frequency of MN was significantly lower in elder (>40 years) individuals from HDG of HLNRA as compared to the young (≤40 years) individuals after 1.0 Gy (P < 0.001) and 2.0 Gy (P = 0.002) of challenging doses. However, young and elder individuals within NLNRA and LDG of HLNRA showed similar frequency of MN after the challenging dose exposures. Thus, increased level of chronic low-dose radiation (>5.0 mGy/year) seems to act as a priming dose resulting in the induction of an in vivo radio-adaptive response in elder individuals of the Kerala coast.
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Affiliation(s)
- E N Ramachandran
- Low Level Radiation Research Laboratory (LLRRL), Radiation Biology and Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala and
| | - C V Karuppasamy
- Low Level Radiation Research Laboratory (LLRRL), Radiation Biology and Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala and
| | - V Anil Kumar
- Low Level Radiation Research Laboratory (LLRRL), Radiation Biology and Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala and
| | - D C Soren
- Low Level Radiation Research Section (LLRRS), RB&HSD, Bio-Science Group, BARC, Trombay, Mumbai 400 085, India
| | - P R Vivek Kumar
- Low Level Radiation Research Laboratory (LLRRL), Radiation Biology and Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala and
| | - P K M Koya
- Low Level Radiation Research Laboratory (LLRRL), Radiation Biology and Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala and
| | - G Jaikrishan
- Low Level Radiation Research Laboratory (LLRRL), Radiation Biology and Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala and
| | - Birajalaxmi Das
- Low Level Radiation Research Section (LLRRS), RB&HSD, Bio-Science Group, BARC, Trombay, Mumbai 400 085, India
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13
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Dass Singh M, Thomas P, Hor M, Almond T, Owens J, Hague W, Fenech M. Infant birth outcomes are associated with DNA damage biomarkers as measured by the cytokinesis block micronucleus cytome assay: the DADHI study. Mutagenesis 2017; 32:355-370. [DOI: 10.1093/mutage/gex001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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14
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Moosavi SA, Ghanbari Z, Farhadi A, Heshmati F, Shabani S, Mofid-Nakhaei MA. Prompt cytomolecular identification of chromosome aberration in irradiated blood cells. RESEARCH IN MOLECULAR MEDICINE 2017. [DOI: 10.29252/rmm.5.1.34] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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15
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Kang CM, Yun HJ, Kim H, Kim CS. Strong Correlation among Three Biodosimetry Techniques Following Exposures to Ionizing Radiation. Genome Integr 2016; 7:11. [PMID: 28217287 PMCID: PMC5292912 DOI: 10.4103/2041-9414.197168] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Three in vitro dose calibration curves for biodosimetry such as dicentric chromosome assay, fluorescence in situ hybridization (FISH) assay for translocation, and micronuclei (MNs) in binucleated cell assay were established after exposure to ionizing radiation. Peripheral blood lymphocyte samples obtained from healthy donors were irradiated with 60Co source at a dose rate of 0.5 Gy/min to doses of 0.1–6 Gy. The results from three in vitro dose calibration curves for biodosimetry were analyzed to understand the relationship among biodosimetry assay techniques. Our comparison demonstrates that there is a very strong positive correlation among the dicentric assay, FISH, and MNs analysis, and these three biodosimetry assays strongly support the in vitro dose reconstruction and the emergency preparedness of public or occupational radiation overexposure.
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Affiliation(s)
- Chang-Mo Kang
- Division of Radiation Effect, Korea Institute of Radiological and Medical Sciences, Seoul 01812, Republic of Korea
| | - Hyun Jin Yun
- Division of Radiation Effect, Korea Institute of Radiological and Medical Sciences, Seoul 01812, Republic of Korea
| | - Hanna Kim
- Radiation Epidemiology Team, Radiation Health Institute, Korea Hydro and Nuclear Power Co., Gyeonggi-do 13605, Republic of Korea
| | - Cha Soon Kim
- Radiation Epidemiology Team, Radiation Health Institute, Korea Hydro and Nuclear Power Co., Gyeonggi-do 13605, Republic of Korea
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16
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Grujičić D, Radović M, Arsenijević S, Milošević-Djordjević O. Cytogenetic biomarkers in detection of genotoxic effects of gestagens in peripheral blood lymphocytes in vitro and in vivo. Eur J Med Genet 2016; 59:624-633. [PMID: 27793715 DOI: 10.1016/j.ejmg.2016.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 09/28/2016] [Accepted: 10/24/2016] [Indexed: 01/02/2023]
Abstract
Gestagens are the most frequently used steroid hormones in hormone-replacement therapy in the treatment of threatened miscarriage during the first trimester of pregnancy. This therapy has been applied in a large number of women with threatened abortion, despite various degrees of success of its efficacy. Genetic factors play a key role in miscarriages, especially in the initial stages. Cytogenetic biomarkers such as micronucleus (MN) test, chromosomal aberrations (CAs), and sister chromatid exchanges (SCEs) provide information on DNA damage. Cytogenetic markers detecting DNA damage have become very popular and useful in analysing genetic risk associated with hormone-replacement therapy. Cytogenetic studies presented heterogenous information. In many in vitro studies synthetic gestagens have been shown to induce genotoxic effects, and it was evaluated using three cytogenetic biomarkers. Genotoxic effects of gestagens have also been confirmed in in vivo studies that were conducted involving patients who received gestagen therapy during pregnancy and their newborns. However, some studies have shown that hormone-replacement therapy does not have genotoxic effects. In this paper, we summarize the results from previous studies. We also describe the usefulness of these biomarkers in the detection of genotoxic effects of hormone-replacement therapy.
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Affiliation(s)
- Darko Grujičić
- Faculty of Science, University of Kragujevac, 34 000, Kragujevac, Serbia.
| | - Marina Radović
- Faculty of Science, University of Kragujevac, 34 000, Kragujevac, Serbia
| | - Slobodan Arsenijević
- Faculty of Medical Sciences, University of Kragujevac, 34 000, Kragujevac, Serbia; Gynaecology Clinic, Clinical Centre Kragujevac, 34 000, Kragujevac, Serbia
| | - Olivera Milošević-Djordjević
- Faculty of Science, University of Kragujevac, 34 000, Kragujevac, Serbia; Faculty of Medical Sciences, University of Kragujevac, 34 000, Kragujevac, Serbia
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17
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Jain V, Kumar PRV, Koya PKM, Jaikrishan G, Das B. Lack of increased DNA double-strand breaks in peripheral blood mononuclear cells of individuals from high level natural radiation areas of Kerala coast in India. Mutat Res 2016; 788:50-7. [PMID: 27063255 DOI: 10.1016/j.mrfmmm.2016.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 02/14/2016] [Accepted: 03/24/2016] [Indexed: 05/19/2023]
Abstract
The high level natural radiation area (HLNRA) of Kerala is a 55km long and 0.5km wide strip in south west coast of India. The level of background radiation in this area varies from <1.0mGy/year to 45.0mGy/year. It offers unique opportunity to study the effect of chronic low dose/low dose-rate radiation directly on human population. Spontaneous level of DNA double strand breaks (DSBs) was quantified in peripheral blood mononuclear cells of 91 random individuals from HLNRA (N=61, mean age: 36.1±7.43years) and normal level natural radiation area (NLNRA) (N=30, mean age: 35.5±6.35years) using gamma-H2AX as a marker. The mean annual dose received by NLNRA and HLNRA individuals was 1.28±0.086mGy/year and 8.28±4.96mGy/year, respectively. The spontaneous frequency of DSBs in terms of gamma-H2AX foci among NLNRA and HLNRA individuals were 0.095±0.009 and 0.084±0.004 per cell (P=0.22). The individuals from HLNRA were further classified as low dose group (LDG, 1.51-5.0mGy/year, mean dose: 2.63±0.76mGy/year) and high dose group (HDG, >5.0mGy/year, mean dose: 11.04±3.57mGy/year). The spontaneous frequency of gamma-H2AX foci per cell in NLNRA, LDG and HDG was observed to be 0.095±0.009, 0.096±0.008 and 0.078±0.004 respectively. Individuals belonging to HDG of HLNRA showed marginally lower frequency of DSBs as compared to NLNRA and LDG of HLNRA. This could be suggestive of either lower induction or better repair of DSBs in individuals from HDG of HLNRA. The present study indicated that 5.0mGy/year could be a possible threshold dose for DSB induction at chronic low-dose radiation exposure in vivo. However, further studies on DNA damage induction and repair kinetics are required to draw firm conclusions.
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Affiliation(s)
- Vinay Jain
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400 094, India
| | - P R Vivek Kumar
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - P K M Koya
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - G Jaikrishan
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
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18
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Karuppasamy CV, Ramachandran EN, Kumar VA, Kumar PRV, Koya PKM, Jaikrishan G, Das B. Peripheral blood lymphocyte micronucleus frequencies in men from areas of Kerala, India, with high vs normal levels of natural background ionizing radiation. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2016; 800-801:40-5. [PMID: 27085474 DOI: 10.1016/j.mrgentox.2016.03.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/09/2016] [Indexed: 12/13/2022]
Abstract
We have measured the frequencies of micronuclei (MN) in adult male individuals living in areas of the Kerala coast, southwest India, with either high (HLNRA, >1.5mGy/year) or normal levels of natural ionizing radiation (NLNRA, ≤1.5mGy/year). Blood samples were obtained from 141 individuals, 94 from HLNRA and 47 from NLNRA, aged 18-72, and were subjected to the cytokinesis-block micronucleus (CBMN) assay. An average of 1835 binucleated (BN) cells per individual were scored. The overall frequency of MN (mean±SD) was 11.7±6.7 per 1000 BN cells. The frequencies of MN in the HLNRA (11.7±6.6) and NLNRA (11.6±6.7) were not statistically significantly different (P=0.59). However, a statistically significant (P<0.001) age-dependent increase in MN frequency was observed among individuals from both HLNRA and NLNRA. No natural background radiation dose-dependent increase in MN frequency was seen. MN frequency was not influenced by tobacco smoking or chewing but it was increased among individuals consuming alcohol. Chronic low-dose radiation in the Kerala coast did not have a significant effect on MN frequency among adult men.
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Affiliation(s)
- C V Karuppasamy
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala, India.
| | - E N Ramachandran
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala, India
| | - V Anil Kumar
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala, India
| | - P R Vivek Kumar
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala, India
| | - P K M Koya
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala, India
| | - G Jaikrishan
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala, India
| | - Birajalaxmi Das
- Low Level Radiation Research Laboratory, Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Science Group, Bhabha Atomic Research Centre (BARC), Beach Road, Kollam 691 001, Kerala, India; LLRRS, RB&HSD, BARC, Trombay, Mumbai 400 085, India.
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19
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Dobrzyński L, Fornalski KW, Feinendegen LE. Cancer Mortality Among People Living in Areas With Various Levels of Natural Background Radiation. Dose Response 2015; 13:1559325815592391. [PMID: 26674931 PMCID: PMC4674188 DOI: 10.1177/1559325815592391] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
There are many places on the earth, where natural background radiation exposures are elevated significantly above about 2.5 mSv/year. The studies of health effects on populations living in such places are crucially important for understanding the impact of low doses of ionizing radiation. This article critically reviews some recent representative literature that addresses the likelihood of radiation-induced cancer and early childhood death in regions with high natural background radiation. The comparative and Bayesian analysis of the published data shows that the linear no-threshold hypothesis does not likely explain the results of these recent studies, whereas they favor the model of threshold or hormesis. Neither cancers nor early childhood deaths positively correlate with dose rates in regions with elevated natural background radiation.
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Affiliation(s)
| | | | - Ludwig E. Feinendegen
- Heinrich-Heine University, Düsseldorf, Germany
- BECS Department, Brookhaven National Laboratory, Upton, NY, USA
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20
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Kumar PRV, Seshadri M, Jaikrishan G, Das B. Effect of chronic low dose natural radiation in human peripheral blood mononuclear cells: Evaluation of DNA damage and repair using the alkaline comet assay. Mutat Res 2015; 775:59-65. [PMID: 25879710 DOI: 10.1016/j.mrfmmm.2015.03.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 03/15/2015] [Accepted: 03/22/2015] [Indexed: 06/04/2023]
Abstract
This study investigates whether peripheral blood mononuclear cells (PBMCs) from inhabitants of Kerala in southwest India, exposed to chronic low dose natural radiation in vivo (>1 mSv year(-1)), respond with a radioadaptive response to a challenging dose of gamma radiation. Toward this goal, PBMCs isolated from 77 subjects from high-level natural radiation areas (HLNRA) and 37 subjects from a nearby normal level natural radiation area (NLNRA) were challenged with 2 Gy and 4 Gy gamma radiation. Subjects from HLNRA were classified based on the mean annual effective dose received, into low dose group (LDG) and high dose group (HDG) with mean annual effective doses of 2.69 mSv (N=43, range 1.07 mSv year(-1) to 5.55 mSv year(-1)) and 9.62 mSv (N = 34, range 6.07 mSv year(-1) to 17.41 mSv year(-1)), respectively. DNA strand breaks and repair kinetics (at 7 min, 15 min and 30 min after 4 Gy) were evaluated using the alkaline single cell gel electrophoresis (comet) assay. Initial levels of DNA strand breaks observed after either a 2 Gy or a 4 Gy challenging dose were significantly lower in subjects of the HDG from HLNRA compared to subjects of NLNRA (2 Gy, P = 0.01; 4 Gy, P = 0.02) and LDG (2 Gy P = 0.01; 4 Gy, P=0.05). Subjects of HDG from HLNRA showed enhanced rejoining of DNA strand breaks (HDG/NLNRA, P = 0.06) during the early stage of repair (within 7 min). However at later times a similar rate of rejoining of strand breaks was observed across the groups (HDG, LDG and NLNRA). Preliminary results from our study suggest in vivo chronic low-level natural radiation provides an initial exposure that allows an adaptation to a subsequent higher radiation exposure, perhaps through improving DNA repair via an unknown mechanism. Therefore, further investigations would be necessary in this population to understand the biological and health effects of chronic low-level natural radiation exposures.
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Affiliation(s)
- P R Vivek Kumar
- Low Level Radiation Research Laboratory, Radiation Biology and Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, IRE Campus, Beach Road, Kollam 691 001, Kerala, India.
| | - M Seshadri
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - G Jaikrishan
- Low Level Radiation Research Laboratory, Radiation Biology and Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, IRE Campus, Beach Road, Kollam 691 001, Kerala, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
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21
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Aliyu AS, Ramli AT. The world's high background natural radiation areas (HBNRAs) revisited: A broad overview of the dosimetric, epidemiological and radiobiological issues. RADIAT MEAS 2015. [DOI: 10.1016/j.radmeas.2015.01.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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22
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Shelke S, Das B. Dose response and adaptive response of non-homologous end joining repair genes and proteins in resting human peripheral blood mononuclear cells exposed to γ radiation. Mutagenesis 2014; 30:365-79. [PMID: 25473122 DOI: 10.1093/mutage/geu081] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Ionising radiation induces single-strand breaks, double-strand breaks (DSB) and base damages in human cell. DSBs are the most deleterious and if not repaired may lead to genomic instability and cell death. DSB can be repaired through non-homologous end joining (NHEJ) pathway in resting lymphocytes. In this study, NHEJ genes and proteins were studied in irradiated human peripheral blood mononuclear cells (PBMC) at resting stage. Dose-response, time point kinetics and adaptive-response studies were conducted in irradiated PBMC at various end points such as DNA damage quantitation, transcription and protein expression profile. Venous blood samples were collected from 20 random, normal and healthy donors with written informed consent. PBMC was separated and irradiated with various doses between 0.1 and 2.0 Gy ((60)CO-γ source) for dose-response study. Repair kinetics of DNA damage and time point changes in expression of genes and proteins were studied in post-irradiated PBMC at 2.0 Gy at various time points up to 240 min. Adaptive-response study was conducted with a priming dose of 0.1 Gy followed by a challenging dose of 2.0 Gy after 4-h incubation. Our results revealed that Ku70, Ku80, XLF and Ligase IV were significantly upregulated (P < 0.05) at 4-h post-irradiation at transcript and protein level. Adaptive-response study showed significantly increased expression of the proteins involved in NHEJ, suggesting their role in adaptive response in human PBMC at G0/G1, which has important implications to human health.
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Affiliation(s)
- Shridevi Shelke
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
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Jain V, Hassan PA, Das B. Radiation-induced conformational changes in chromatin structure in resting human peripheral blood mononuclear cells. Int J Radiat Biol 2014; 90:1143-51. [PMID: 24844371 DOI: 10.3109/09553002.2014.925605] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
UNLABELLED Abstract Background: Ionizing radiation induces a plethora of DNA damage including double-strand breaks (DSB) that may trigger a series of events such as transcription, DNA repair and alteration in the conformation of chromatin structure in human cells. We have made an attempt to study the conformational changes in chromatin fibers in irradiated human peripheral blood mononuclear cells (PBMC) using Dynamic Light Scattering (DLS) as a new tool. MATERIALS AND METHODS Venous blood samples were collected from 10 random, healthy individuals with written informed consent, approved by institutional ethics committee. PBMC were separated from blood, irradiated with different doses of gamma radiation from 0.25-1.0 Gy. Native chromatin was isolated from irradiated PBMC and changes in the hydrodynamic diameter of the chromatin fiber were measured using DLS. Both dose response and time kinetics was studied in order to see the chromatin changes. Radiation-induced DNA double-strand breaks were measured using gamma-H2AX (histone 2A member X) as a biomarker using flow cytometry and foci were visualized in confocal microscopy. RESULTS A significant alteration in hydrodynamic diameter of the chromatin fiber was observed at lower doses (0.25 and 0.50 Gy), whereas at higher dose (1.0 Gy), the size of the chromatin fiber was comparable to unirradiated control. Among the 10 individuals studied, five individuals showed significant increase (p ≤ 0.002) in hydrodynamic size at 0.25 Gy whereas four individuals showed significant decrease (p ≤ 0.009) at 0.25 Gy. One individual did not show any significant difference as compared to control. However, dose-dependent increase in gamma-H2AX fluorescence signals as well as foci number was observed. Increased fragmentation of chromatin fiber was also observed using Atomic Force Microscopy at higher doses. CONCLUSION Radiation-induced DNA damage response can lead to individual specific conformational changes in chromatin structure at lower doses (0.25 Gy and 0.50 Gy) which can be detected using dynamic light scattering method in resting human PBMC.
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Affiliation(s)
- Vinay Jain
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio Science Group, Bhabha Atomic Research Centre , Trombay, Mumbai-400 085 , India
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Alvarado-Hernandez DL, Montero-Montoya R, Serrano-García L, Arellano-Aguilar O, Jasso-Pineda Y, Yáñez-Estrada L. Assessment of exposure to organochlorine pesticides and levels of DNA damage in mother-infant pairs of an agrarian community. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2013; 54:99-111. [PMID: 23355095 DOI: 10.1002/em.21753] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 10/24/2012] [Accepted: 10/25/2012] [Indexed: 06/01/2023]
Abstract
Exposure to organochlorine pesticides was studied in a group of mother-infant pairs living in a rural area where agriculture is the main economic activity. Fumigation in this zone is performed with airplanes, thus affecting the inhabited areas around them, including schools. Heparinized venous blood of mothers and umbilical cords was used to evaluate the olive tail moment in the comet assay, and micronuclei, chromatin buds, and nucleoplasmic bridges in peripheral blood lymphocytes. Cord blood samples were taken at the moment of birth only from natural and normal parturitions. Determinations of hexachlorobenzene, aldrin, heptachlor epoxide, oxichlordane, t and c-chlordane, cis-nonachlor, mirex, alpha and beta-endosulfan, alpha, beta and gamma hexachlorocyclohexane, and p'p'-DDT, p'p'-DDE were conducted to establish the differential distribution of the toxicants between compartments, i.e., mother and umbilical cord. Significantly higher pesticide levels were found in umbilical cord plasma than in mothers' plasma for almost all compounds tested, except DDE and oxychlordane. Significantly higher olive tail moments were found in umbilical cords than in mothers, whereas micronuclei frequencies were higher in mothers than in umbilical cords. However, neither the levels of micronuclei nor the olive tail moment were correlated with pesticide levels. Given that no other exposure to toxic compounds has been identified in this region, the lack of correlation between genotoxicity biomarkers and pesticide levels may be due to the variability of the exposure and to endogenous processes related to lipid mobility during pregnancy, the metabolism of the compounds, and individual susceptibilities.
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Affiliation(s)
- Diana Lorena Alvarado-Hernandez
- Departamento de Toxicología Ambiental, Facultad de Medicina, Laboratorio de Género, Salud y Ambiente, Universidad Autónoma de San Luis Potosí, San Luis Potosí, S.L.P., México
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Ahmad S, Koya PKM, Seshadri M. Effects of chronic low level radiation in the population residing in the high level natural radiation area in Kerala, India: employing heritable DNA mutation studies. Mutat Res 2012; 751:91-5. [PMID: 23253487 DOI: 10.1016/j.mrgentox.2012.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 11/11/2012] [Accepted: 12/03/2012] [Indexed: 11/26/2022]
Abstract
To study the effect of chronic low level radiation, 4040 meiosis were screened at eight microsatellite and five minisatellite (2485 and 1555 meiosis respectively) marker loci in people residing in high and normal level natural radiation areas of Kerala. Variants in the repeat length of allele were considered as mutants. Mutation rates (expressed as the number of mutations observed in the total number of meiosis) were 6.4×10(-3) (16/2485) and 2.6×10(-3) (4/1555) at microsatellite and minisatellite respectively. The germline microsatellite mutation frequency of father was 1.78 times higher at 7.52×10(-3) (8/1064) compared to 4.22×10(-3) (6/1421) of mother (P=0.292, Fisher's Exact two-sided test). The paternal and maternal mutation rates at minisatellite loci were more or less similar at 2.78×10(-3) (2/719) and 2.39×10(-3) (2/836), respectively (P=1.0, Fisher's Exact two-sided test). Higher but statistically non-significant microsatellite mutation frequency was observed in HLNRA compared to NLNRA (7.25×10(-3) vs 3.64×10(-3); P=0.547). The apparent increase in the mutation rate of microsatellite loci with the increase in radiation dose was also not statistically significant. All the four minisatellite mutation observed were from HLNRA (1198 meiosis) and no mutation was observed among 357 meiosis screened from NLNRA families. All the markers used in the present study were in the non-coding region and hence mutations in these regions may not cause adverse health effects, but the study is important in understanding the effect of chronic low level radiation.
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Affiliation(s)
- Shazia Ahmad
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India.
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Ramachandran EN, Karuppasamy CV, Cheriyan VD, Soren DC, Das B, Anilkumar V, Koya PKM, Seshadri M. Cytogenetic studies on newborns from high and normal level natural radiation areas of Kerala in southwest coast of India. Int J Radiat Biol 2012; 89:259-67. [DOI: 10.3109/09553002.2013.747014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Møller AP, Mousseau TA. The effects of natural variation in background radioactivity on humans, animals and other organisms. Biol Rev Camb Philos Soc 2012; 88:226-54. [DOI: 10.1111/j.1469-185x.2012.00249.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 09/26/2012] [Accepted: 10/05/2012] [Indexed: 01/23/2023]
Affiliation(s)
- Anders P. Møller
- Laboratoire d'Ecologie; Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud; Bâtiment 362; F-91405; Orsay Cedex; France
| | - Timothy A. Mousseau
- Department of Biological Sciences; University of South Carolina; Columbia; SC; 29208; USA
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Study of stillbirth and major congenital anomaly among newborns in the high-level natural radiation areas of Kerala, India. J Community Genet 2012; 4:21-31. [PMID: 22875746 DOI: 10.1007/s12687-012-0113-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 07/25/2012] [Indexed: 10/28/2022] Open
Abstract
Monitoring newborns for adverse outcomes like stillbirth and major congenital anomalies (MCA) is being carried out in government hospitals since 1995 in and around high-level natural radiation areas, a narrow strip of land on the southwest coast of Kerala, India. Natural deposits of monazite sand containing thorium and its daughter products account for elevated levels of natural radiation. Among 141,540 newborns [140,558 deliveries: 139,589 singleton, 957 twins (6.81 ‰), 11 triplets (0.078 ‰), and one quadruplet] screened, 615 (4.35 ‰) were stillbirth and MCA were seen in 1,370 (9.68 ‰) newborns. Clubfoot (404, 2.85 ‰) was the most frequent MCA followed by hypospadias (152, 2.10 ‰ among male newborns), congenital heart disease (168, 1.19 ‰), cleft lip/palate (149, 1.05 ‰), Down syndrome (104, 0.73 ‰), and neural tube defects (72, 0.51 ‰). Newborns with MCA among stillbirths were about 20-fold higher at 190.24 ‰ (117/615) compared to 8.89 ‰ (1,253/140,925) among live births (P < .001). Logistic regression was carried out to compare stillbirth, overall, and specific MCA among newborns from areas with dose levels of ≤1.5, 1.51-3.0, 3.01-6.0 and >6 mGy/year after controlling for maternal age at birth, gravida, consanguinity, ethnicity, and gender of the baby. Clubfoot showed higher prevalence of 3.26 ‰ at dose level of 1.51-3.0 mGy/year compared to 2.33 ‰ at ≤1.5 mGy/year (OR = 1.39; 95 % CI, 1.12-1.72), without indication of any clear dose-response. Prevalences of stillbirth, overall MCA, and other specific MCA were similar across different dose levels and were relatively lower than that reported elsewhere in India, probably due to better literacy, health awareness, and practices in the study population.
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Das B, Saini D, Seshadri M. No evidence of telomere length attrition in newborns from high level natural background radiation areas in Kerala coast, south west India. Int J Radiat Biol 2012; 88:642-7. [DOI: 10.3109/09553002.2012.699135] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Vande Loock K, Ciardelli R, Decordier I, Plas G, Haumont D, Kirsch-Volders M. Preterm newborns show slower repair of oxidative damage and paternal smoking associated DNA damage. Mutagenesis 2012; 27:573-80. [PMID: 22553360 DOI: 10.1093/mutage/ges022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Newborns have to cope with hypoxia during delivery and a sudden increase in oxygen at birth. Oxygen will partly be released as reactive oxygen species having the potential to cause damage to DNA and proteins. In utero, increase of most (non)-enzymatic antioxidants occurs during last weeks of gestation, making preterm neonates probably more sensitive to oxidative stress. Moreover, it has been hypothesized that oxidative stress might be the common etiological factor for certain neonatal diseases in preterm infants. The aim of this study was to assess background DNA damage; in vitro H(2)O(2) induced oxidative DNA damage and repair capacity (residual DNA damage) in peripheral blood mononucleated cells from 25 preterm newborns and their mothers. In addition, demographic data were taken into account and repair capacity of preterm was compared with full-term newborns. Multivariate linear regression analysis revealed that preterm infants from smoking fathers have higher background DNA damage levels than those from non-smoking fathers, emphasizing the risk of paternal smoking behaviour for the progeny. Significantly higher residual DNA damage found after 15-min repair in preterm children compared to their mothers and higher residual DNA damage after 2 h compared to full-term newborns suggest a slower DNA repair capacity in preterm children. In comparison with preterm infants born by caesarean delivery, preterm infants born by vaginal delivery do repair more slowly the in vitro induced oxidative DNA damage. Final impact of passive smoking and of the slower DNA repair activity of preterm infants need to be confirmed in a larger study population combining transgenerational genetic and/or epigenetic effects, antioxidant levels, genotypes, repair enzyme efficiency/levels and infant morbidity.
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Affiliation(s)
- Kim Vande Loock
- Laboratory of Cell Genetics, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium.
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Kumar PRV, Cheriyan VD, Seshadri M. Evaluation of Spontaneous DNA Damage in Lymphocytes of Healthy Adult Individuals from High-Level Natural Radiation Areas of Kerala in India. Radiat Res 2012; 177:643-50. [DOI: 10.1667/rr2681.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Kaspler P, Chen R, Hyrien O, Jelveh S, Bristow RG, Hill RP. Biodosimetry using radiation-induced micronuclei in skin fibroblasts. Int J Radiat Biol 2012; 87:824-38. [PMID: 21801108 DOI: 10.3109/09553002.2011.582927] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE We assessed micronuclei in dermal fibroblasts as a local biodosimeter for estimating accidental in vivo radiation exposure. MATERIALS AND METHODS Male and female C3H/HeJ and C57Bl6 mice of four age groups (∼11, 36, 60 and 99 weeks) received a single whole body dose of gamma radiation (0-10 Gy) and radiation-induced micronuclei per 1,000 binucleated cells were assessed in skin fibroblasts in their first division after isolation from biopsies taken on days 1 and 7 post irradiation. The method of generalized estimating equations was used for statistical analyses. RESULTS Total micronuclei were increased on day 1 in a dose-dependent manner in the range of 1-10 Gy, with no significant attenuation of response between day 1 and day 7 and no significant effect of gender. Between-strain differences were observed with C3H/HeJ mice showing lower background micronuclei and a slightly steeper dose response. Age affected only the background micronuclei (moderate increase with age). The model demonstrated that the assay yields 'unbiased' prediction of the dose between 0 and 7 Gy. Within this dose range, the predicted dose was found to be accurate within ±1.5-2 Gy. When the specificity is set to 95%, the assay can distinguish between unexposed and 2 Gy exposed mice with a sensitivity of around 60%. The sensitivity approached 100% when discriminating between unexposed mice and mice receiving doses equal to or greater than 4 Gy. The percentage of binucleated cells with micronuclei was shown to be useful as a simpler and slightly faster substitute for the total micronuclei count. CONCLUSION Micronuclei in dermal fibroblasts isolated up to 1 week after irradiation can be a useful biodosimeter for local dose after accidental radiation exposure.
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Affiliation(s)
- Pavel Kaspler
- Ontario Cancer Institute/Princess Margaret Hospital, University Health Network and Campbell Family Institute for Cancer Research, Toronto, Ontario, Canada
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Vande Loock K, Fthenou E, Decordier I, Chalkiadaki G, Keramarou M, Plas G, Roelants M, Kleinjans J, Chatzi L, Merlo F, Kogevinas M, Kirsch-Volders M. Maternal and gestational factors and micronucleus frequencies in umbilical blood: the NewGeneris Rhea cohort in Crete. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:1460-5. [PMID: 21622084 PMCID: PMC3230441 DOI: 10.1289/ehp.1003246] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Accepted: 05/27/2011] [Indexed: 05/17/2023]
Abstract
BACKGROUND The use of cancer-related biomarkers in newborns has been very limited. OBJECTIVE We investigated the formation of micronuclei (MN) in full-term and preterm newborns and their mothers from the Rhea cohort (Crete), applying for the first time in cord blood a validated semiautomated analysis system, in both mono- and binucleated T lymphocytes. METHODS We assessed MN frequencies in peripheral blood samples from the mothers and in umbilical cord blood samples. We calculated MN in mononucleated (MNMONO) and binucleated (MNBN) T lymphocytes and the cytokinesis block proliferation index (CBPI) in 251 newborns (224 full term) and 223 mothers, including 182 mother-child pairs. Demographic and lifestyle characteristics were collected. RESULTS We observed significantly higher MNBN and CBPI levels in mothers than in newborns. In newborns, MNMONO and MNBN were correlated (r = 0.35, p < 0.001), and we found a moderate correlation between MNMONO in mothers and newborns (r = 0.26, p < 0.001). MNMONO frequencies in newborns were positively associated with the mother's body mass index and inversely associated with gestational age and mother's age, but we found no significant predictors of MNBN or CBPI in newborns. CONCLUSIONS Although confirmation is needed by a larger study population, the results indicate the importance of taking into account both mono- and binucleated T lymphocytes for biomonitoring of newborns, because the first reflects damage expressed during in vivo cell division and accumulated in utero, and the latter includes additional damage expressed as MN during the in vitro culture step.
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Affiliation(s)
- Kim Vande Loock
- Laboratory of Cell Genetics, Faculty of Science and Bio-engineering, Vrije Universiteit Brussel, Brussels, Belgium.
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Matsuda N, Brahmanandhan GM, Yoshida M, Takamura N, Suyama A, Koguchi Y, Juto N, Raj YL, Winsley G, Selvasekarapandian S. Background radiation and individual dosimetry in the costal area of Tamil Nadu, India. RADIATION PROTECTION DOSIMETRY 2011; 146:314-317. [PMID: 21502300 DOI: 10.1093/rpd/ncr179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
South coast of India is known as the high-level background radiation area (HBRA) mainly due to beach sands that contain natural radionuclides as components of the mineral monazite. The rich deposit of monazite is unevenly distributed along the coastal belt of Tamil Nadu and Kerala. An HBRA site that laid in 2×7 m along the sea was found in the beach of Chinnavillai, Tamil Nadu, where the maximum ambient dose equivalent reached as high as 162.7 mSv y(-1). From the sands collected at the HBRA spot, the high-purity germanium semi-conductor detector identified six nuclides of thorium series, four nuclides of uranium series and two nuclides belonging to actinium series. The highest radioactivity observed was 43.7 Bq g(-1) of Th-228. The individual dose of five inhabitants in Chinnavillai, as measured by the radiophotoluminescence glass dosimetry system, demonstrated the average dose of 7.17 mSv y(-1) ranging from 2.79 to 14.17 mSv y(-1).
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Affiliation(s)
- Naoki Matsuda
- Center for Frontier Life Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
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Comparison of the micronucleus and chromosome aberration techniques for the documentation of cytogenetic damage in radiochemotherapy-treated patients with rectal cancer. Strahlenther Onkol 2010; 187:52-8. [PMID: 21234528 DOI: 10.1007/s00066-010-2163-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Accepted: 09/16/2010] [Indexed: 01/08/2023]
Abstract
PURPOSE The goal of the interdisciplinary Clinical Research Unit KFO179 (Biological Basis of Individual Tumor Response in Patients with Rectal Cancer) is to develop an individual Response and Toxicity Score for patients with locally advanced rectal cancer treated with neoadjuvant radiochemotherapy. The aim of the present study was to find a reliable and sensitive method with easy scoring criteria and high numbers of cell counts in a short period of time in order to analyze DNA damage in peripheral blood lymphocytes. Thus, the cytokinesis-block micronucleus (CBMN) assay and the chromosome aberration technique (CAT) were tested. MATERIALS AND METHODS Peripheral blood lymphocytes obtained from 22 patients with rectal cancer before (0 Gy), during (21.6 Gy), and after (50.4 Gy) radiochemotherapy were stimulated in vitro by phytohemagglutinin (PHA); the cultures were then processed for the CBMN assay and the CAT to compare the two methods. RESULTS A significant increase of chromosomal damage was observed in the course of radiochemotherapy parallel to increasing radiation doses, but independent of the chemotherapy applied. The equivalence of both methods was shown by Westlake's equivalence test. CONCLUSION The results show that the CBMN assay and the CAT are equivalent. For further investigations, we prefer the CBMN assay, because it is simpler through easy scoring criteria, allows high numbers of cell counts in less time, is reliable, sensitive, and has higher statistical power. In the future, we plan to integrate cytogenetic damage during radiochemotherapy into the planned Response and Toxicity Score within our interdisciplinary Clinical Research Unit.
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Pandey BN, Kumar A, Tiwari P, Mishra KP. Radiobiological basis in management of accidental radiation exposure. Int J Radiat Biol 2010; 86:613-35. [DOI: 10.3109/09553001003746059] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Das B, Saini D, Seshadri M. Telomere length in human adults and high level natural background radiation. PLoS One 2009; 4:e8440. [PMID: 20037654 PMCID: PMC2793520 DOI: 10.1371/journal.pone.0008440] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 11/22/2009] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Telomere length is considered as a biomarker of aging, stress, cancer. It has been associated with many chronic diseases such as hypertension and diabetes. Although, telomere shortening due to ionizing radiation has been reported in vitro, no in vivo data is available on natural background radiation and its effect on telomere length. METHODOLOGY/PRINCIPAL FINDINGS The present investigation is an attempt to determine the telomere length among human adults residing in high level natural radiation areas (HLNRA) and the adjacent normal level radiation areas (NLNRA) of Kerala coast in Southwest India. Genomic DNA was isolated from the peripheral blood mononuclear cells of 310 individuals (HLNRA: N = 233 and NLNRA: N = 77). Telomere length was determined using real time q-PCR. Both telomere (T) and single copy gene (S) specific primers were used to calculate the relative T/S and expressed as the relative telomere length. The telomere length was determined to be 1.22+/-0.15, 1.12+/-0.15, 1.08+/-0.08, 1.12+/-0.11, respectively, among the four dose groups (=1.50, 1.51-3.00, 3.01-5.00 and >5.00 mGy per year), which did not show any dose response. The results suggested that the high level natural chronic radiation did not have significant effect on telomere length among young adult population living in HLNRA, which is indicative of better repair of telomeric ends. No significant difference in telomere length was observed between male and female individuals. In the present investigation, although the determination of telomere length was studied among the adults with an age group between 18 to 40 years (mean maternal age: 26.10+/-4.49), a negative correlation was observed with respect to age. However, inter-individual variation was (0.81-1.68) was clearly observed. CONCLUSIONS/SIGNIFICANCE In this preliminary investigation, we conclude that elevated level of natural background radiation has no significant effect on telomere length among the adult population residing in HLNRAs of Kerala coast. To our knowledge, this is the first report from HLNRAs of the world where telomere length was determined on human adults. However, more samples from each background dose group and samples from older population need to be studied to derive firm conclusions.
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Affiliation(s)
- Birajalaxmi Das
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India.
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