| 1. |
- Ainsbury, Elizabeth, et al.
(författare)
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Integration of new biological and physical retrospective dosimetry methods into EU emergency response plans - joint RENEB and EURADOS inter-laboratory comparisons
- 2017
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Ingår i: International Journal of Radiation Biology. - : Informa UK Limited. - 0955-3002 .- 1362-3095. ; 93:1, s. 99-109
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: RENEB, 'Realising the European Network of Biodosimetry and Physical Retrospective Dosimetry,' is a network for research and emergency response mutual assistance in biodosimetry within the EU. Within this extremely active network, a number of new dosimetry methods have recently been proposed or developed. There is a requirement to test and/or validate these candidate techniques and inter-comparison exercises are a well-established method for such validation. Materials and methods: The authors present details of inter-comparisons of four such new methods: dicentric chromosome analysis including telomere and centromere staining; the gene expression assay carried out in whole blood; Raman spectroscopy on blood lymphocytes, and detection of radiation induced thermoluminescent signals in glass screens taken from mobile phones. Results: In general the results show good agreement between the laboratories and methods within the expected levels of uncertainty, and thus demonstrate that there is a lot of potential for each of the candidate techniques. Conclusions: Further work is required before the new methods can be included within the suite of reliable dosimetry methods for use by RENEB partners and others in routine and emergency response scenarios.
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| 2. |
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| 3. |
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| 4. |
- Kulka, Ulrike, et al.
(författare)
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RENEB - Running the European Network of biological dosimetry and physical retrospective dosimetry
- 2017
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Ingår i: International Journal of Radiation Biology. - : Informa UK Limited. - 0955-3002 .- 1362-3095. ; 93:1, s. 2-14
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: A European network was initiated in 2012 by 23 partners from 16 European countries with the aim to significantly increase individualized dose reconstruction in case of large-scale radiological emergency scenarios. Results: The network was built on three complementary pillars: (1) an operational basis with seven biological and physical dosimetric assays in ready-to-use mode, (2) a basis for education, training and quality assurance, and (3) a basis for further network development regarding new techniques and members. Techniques for individual dose estimation based on biological samples and/or inert personalized devices as mobile phones or smart phones were optimized to support rapid categorization of many potential victims according to the received dose to the blood or personal devices. Communication and cross-border collaboration were also standardized. To assure long-term sustainability of the network, cooperation with national and international emergency preparedness organizations was initiated and links to radiation protection and research platforms have been developed. A legal framework, based on a Memorandum of Understanding, was established and signed by 27 organizations by the end of 2015. Conclusions: RENEB is a European Network of biological and physical-retrospective dosimetry, with the capacity and capability to perform large-scale rapid individualized dose estimation. Specialized to handle large numbers of samples, RENEB is able to contribute to radiological emergency preparedness and wider large-scale research projects.
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| 5. |
- Meijer, Annelie, 1967-
(författare)
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Radiation-induced apoptosis in human lymphocytes : studies on expression, function and effects of different radiation qualities
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- We are constantly exposed to radiation. Radiation causes damage to our cells. By the removal of damaged and unwanted cells, apoptosis is considered to be one of the most indispensable defence processes for a multi-cellular organism.To improve the knowledge and understanding of the expression and function of apoptosis in human cells exposed to radiation of different qualities, lymphocytes from healthy individuals and radiosensitive individuals suffering from ataxia telangiectasia (A-T) were studied. Studies on radiation-induced chromosomal aberrations (CA) in normal cells revealed that the expression of apoptosis significantly reduced the number of cells with CA after the first mitosis. For the induction of chromosomal instability observed after several cell divisions, neither a prolonged apoptotic expression time nor a lower genotoxic stress by low dose-rate (LDR) irradiation, seemed to influence the response.Further investigations on the effects of LDR exposure on apoptosis indicated a dose-rate effect, although not statistically verified. A prolonged post-irradiation time in G0-phase was shown to significantly increase the apoptotic response, which was efficiently counteracted by addition of growth factors.The apoptotic response was found to be significantly increased after exposure to high linear energy transfer (LET) radiation compared to low-LET. High-LET irradiation did not only increase the frequency of apoptotic cells, but did also induce a significantly faster apoptotic response, which revealed time-dependent relative biological effectiveness (RBE) values in the range of 1.3-3.0.In studies on the expression of radiation-induced apoptosis in A-T cells it was found that low-LET irradiation did neither induce apoptosis, G1-phase arrest nor enhanced levels of p53/p21 (WAF1) proteins. However, high-LET irradiation did induce apoptosis and G1-phase arrest in A-T cells, despite the absence of a p53/p21(WAF1) response.
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| 6. |
- Mosesso, Pasquale, et al.
(författare)
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Relationship between chromatin structure, DNA damage and repair following X-irradiation of human lymphocytes
- 2010
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Ingår i: Mutation research. Genetic toxicology and environmental mutagenesis. - : Elsevier BV. - 1383-5718 .- 1879-3592. ; 701:1, s. 86-91
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Tidskriftsartikel (refereegranskat)abstract
- Earlier studies using the technique of premature chromosome condensation (PCC) have shown that in human lymphocytes, exchange type of aberrations are formed immediately following low doses (<2 Gy) of X-rays, whereas at higher doses these aberrations increase with the duration of recovery. This reflects the relative roles of slow and fast repair in the formation of exchange aberrations. The underlying basis for slow and fast repairing components of the DNA repair may be related to differential localization of the initial damage in the genome, i.e., between relaxed and condensed chromatin. We have tried to gain some insight into this problem by (a) X-irradiating lymphocytes in the presence of dimethyl sulfoxide (DMSO) a potent scavenger of radiation-induced (center dot)OH radicals followed by PCC and (b) probing the damage and repair in two specific chromosomes, 18 and 19, which are relatively poor and rich in transcribing genes by COMET-FISH, a combination of Comet assay and fluorescence in situ hybridization (FISH) techniques. Results obtained show (a) that both fast appearing and slowly formed exchange aberrations seem to take place in relaxed chromatin, since they are affected to a similar extent by DMSO, (b) significant differential DNA breakage of chromosome 18 compared to chromosome 19 in both GO and G1 phases of the cell cycle as detected by Comet assay, indicating that relaxed chromatin containing high densities of transcriptionally active genes shows less fragmentation due to fast repair (chromosome 19) compared to chromosome 18, and (c) that relaxed chromatin is repaired or mis-repaired faster than more compact chromatin.
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| 7. |
- Natarajan, Adayapalam T., et al.
(författare)
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Influence of DMSO on Carbon K ultrasoft X-rays induced chromosome aberrations in V79 Chinese hamster cells
- 2010
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Ingår i: Mutation research. - : Elsevier BV. - 0027-5107 .- 1873-135X. ; 691:02-jan, s. 23-26
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Tidskriftsartikel (refereegranskat)abstract
- Ultrasoft X-rays have been shown to be very efficient in inducing chromosomal aberrations in mammalian cells. The present study was aimed to evaluate the modifying effects of DMSO (a potent scavenger of free radicals) on the frequencies of chromosome aberrations induced by soft X-rays. Confluent held G1 Chinese hamster cells (V79) were irradiated with Carbon K ultrasoft X-rays in the presence and absence of 1 M DMSO and frequencies of chromosome aberrations in the first division cells were determined. DMSO reduced the frequencies of exchange types of aberrations (dicentrics and centric rings) by a factor of 2.1-3.5. The results indicate that free radicals induced by ultrasoft X-rays contribute to a great extent to the induction of chromosome aberrations. The possible implications of these results in interpreting the mechanisms involved in the high efficiency of ultrasoft X-rays in the induction of chromosome aberrations are discussed.
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| 8. |
- Nilsson, Robert, et al.
(författare)
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Exposure to polycyclic aromatic hydrocarbons in women from Poland, Serbia and Italy - relation between PAH metabolite excretion, DNA damage, diet and genotype (the EU DIEPHY project)
- 2013
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Ingår i: Biomarkers. - 1354-750X .- 1366-5804. ; 18:2, s. 165-173
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Tidskriftsartikel (refereegranskat)abstract
- Exposure of the general population to polycyclic aromatic hydrocarbons (PAH) is ubiquitous. The aim of this study was to analyze biomarkers associated with the uptake of PAH in 428 non-smoking women from Lodz (Poland), Viterbo (Italy), Belgrade (Serbia) and from the Pancevo area, where the petrochemical complex was destroyed by the air raids in 1999. Urinary excretion of PAH metabolites was lowest in Italian women, intermediary for Serbian and highest in Polish women, who predominantly excreted hydroxy phenanthrenes as metabolites of phenanthrene. Bulky DNA adduct levels were highest in Italian and Polish women. Genotype or PAH ambient air levels could not explain the dissimilarities between the study groups with respect to biomarker patterns, which probably reflected differences in life style-associated factors.
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| 9. |
- Romm, Horst, et al.
(författare)
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Web based scoring is useful for validation and harmonisation of scoring criteria within RENEB
- 2017
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Ingår i: International Journal of Radiation Biology. - : Informa UK Limited. - 0955-3002 .- 1362-3095. ; 93:1, s. 110-117
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To establish a training data set of digital images and to investigate the scoring criteria and dose assessment of the dicentric assay within the European network of biodosimetry (RENEB), a web based scoring inter-comparison was undertaken by 17 RENEB partners. Materials and methods: Two sets of 50 high resolution images were uploaded onto the RENEB web site. One set included metaphases after a moderate exposure (1.3 Gy) and the other set consisted of metaphases after a high dose exposure (3.5 Gy). The laboratories used their own calibration curves for estimating doses based on observed aberration frequencies. Results: The dose estimations and 95% confidence limits were compared to the actual doses and the corresponding z-values were satisfactory for the majority; only the dose estimations from two laboratories were too low or too high. The coefficients of variation were 17.6% for the moderate and 11.2% for the high dose. Metaphases with controversial results could be identified for training purposes. Conclusions: Overall, the web based scoring of the two galleries by the 17 laboratories produced very good results. Application of web based scoring for the dicentric assay may therefore be a relevant strategy for an operational biodosimetry assistance network.
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| 10. |
- Terzoudi, Georgia I., et al.
(författare)
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Dose assessment intercomparisons within the RENEB network using G(0)-lymphocyte prematurely condensed chromosomes (PCC assay)
- 2017
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Ingår i: International Journal of Radiation Biology. - : Informa UK Limited. - 0955-3002 .- 1362-3095. ; 93:1, s. 48-57
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Dose assessment intercomparisons within the RENEB network were performed for triage biodosimetry analyzing G(0)-lymphocyte PCC for harmonization, standardization and optimization of the PCC assay. Materials and methods: Comparative analysis among different partners for dose assessment included shipment of PCC-slides and captured images to construct dose-response curves for up to 6 Gy gamma-rays. Accident simulation exercises were performed to assess the suitability of the PCC assay by detecting speed of analysis and minimum number of cells required for categorization of potentially exposed individuals. Results: Calibration data based on Giemsa-stained fragments in excess of 46 PCC were obtained by different partners using galleries of PCC images for each dose-point. Mean values derived from all scores yielded a linear dose-response with approximately 4 excess-fragments/cell/Gy. To unify scoring criteria, exercises were carried out using coded PCC-slides and/or coded irradiated blood samples. Analysis of samples received 24h post-exposure was successfully performed using Giemsa staining (1 excess-fragment/cell/Gy) or centromere/telomere FISH-staining for dicentrics. Conclusions: Dose assessments by RENEB partners using appropriate calibration curves were mostly in good agreement. The PCC assay is quick and reliable for whole- or partial-body triage biodosimetry by scoring excess-fragments or dicentrics in G(0)-lymphocytes. Particularly, analysis of Giemsa-stained excess PCC-fragments is simple, inexpensive and its automation could increase throughput and scoring objectivity of the PCC assay.
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