Rositsa Hristova - Academia.edu (original) (raw)

Papers by Rositsa Hristova

Radiation Research

After large-scale radiation accidents where many individuals are suspected to be exposed to ioniz... more After large-scale radiation accidents where many individuals are suspected to be exposed to ionizing radiation, biological and physical retrospective dosimetry assays are important tools to aid clinical decision making by categorizing individuals into unexposed/minimally, moderately or highly exposed groups. Quality-controlled inter-laboratory comparisons of simulated accident scenarios are regularly performed in the frame of the European legal association RENEB (Running the European Network of Biological and Physical retrospective Dosimetry) to optimize international networking and emergency readiness in case of large-scale radiation events. In total 33 laboratories from 22 countries around the world participated in the current RENEB inter-laboratory comparison 2021 for the dicentric chromosome assay. Blood was irradiated in vitro with X rays (240 kVp, 13 mA, ∼75 keV, 1 Gy/min) to simulate an acute, homogeneous whole-body exposure. Three blood samples (no. 1: 0 Gy, no. 2: 1.2 Gy, n...

Radiation Protection Dosimetry, 2014

In the event of a mass casualty radiation incident, the gamma-H2AX foci assay could be a useful t... more In the event of a mass casualty radiation incident, the gamma-H2AX foci assay could be a useful tool to estimate radiation doses received by individuals. The rapid processing time of blood samples of just a few hours and the potential for batch processing, enabling high throughput, make the assay ideal for early triage categorisation to separate the 'worried well' from the low and critically exposed by quantifying radiation-induced foci in peripheral blood lymphocytes. Within the RENEB framework, 8 European laboratories have taken part in the first European gamma-H2AX biodosimetry exercise, which consisted of a telescoring comparison of 200 circulated foci images taken from 8 samples, and a comparison of 10 fresh blood lymphocyte samples that were shipped overnight to participating labs 4 or 24 h post-exposure. Despite large variations between laboratories in the doseresponse relationship for foci induction, the obtained results indicate that the network should be able to use the gamma-H2AX assay for rapidly identifying the most severely exposed individuals within a cohort who could then be prioritised for accurate chromosome dosimetry.

Journal of Radiation Research

The purpose of the present study is to evaluate the effect of curcumin as a natural compound agai... more The purpose of the present study is to evaluate the effect of curcumin as a natural compound against radiation induced γ-foci and stable chromosome aberrations. Whole blood samples form three human volunteers were pretreated with curcumin at different concentrations (0.5, 10, 20 and 100 μg/ml). After 1-hour incubation, the lymphocytes were exposed to γ-rays (0.05, 0.5, 1 and 2 Gy). Radiation induced changes in cells were quantified using γ-H2AX/53BP1 assay and FISH analysis. Our results have shown that curcumin significantly reduced the frequency of both γ-foci and translocations. We found concentration-dependent increase of curcumin protective effect on γ-H2AX/53BP1 foci formation at all radiation doses. Concerning the translocations, after 0.05 and 0.5 Gy γ-rays the values of genomic frequencies are comparable within each dose and we did not observe any impact of curcumin. The most protective effect after 1 Gy exposure was found at 100 μg/ml curcumin. At 2 Gy irradiation, the maxi...

International Journal of Radiation Biology, 2021

Purpose: Biological and/or physical assays for retrospective dosimetry are valuable tools to reco... more Purpose: Biological and/or physical assays for retrospective dosimetry are valuable tools to recover the exposure situation and to aid medical decision making. To further validate and improve such biological and physical assays, in 2019, EURADOS Working Group 10 and RENEB performed a field exercise in Lund, Sweden, to simulate various real-life exposure scenarios. Materials and methods: For the dicentric chromosome assay (DCA), blood tubes were located at anthropomorphic phantoms positioned in different geometries and were irradiated with a 1.36 TBq 192 Ir-source. For each exposure condition, dose estimates were provided by at least one laboratory and for four conditions by 17 participating RENEB laboratories. Three radio-photoluminescence glass dosimeters were placed at each tube to assess reference doses. Results: The DCA results were homogeneous between participants and matched well with the reference doses (!95% of estimates within ±0.5 Gy of the reference). For samples close to the source systematic underestimation could be corrected by accounting for exposure time. Heterogeneity within and between tubes was detected for reference doses as well as for DCA doses estimates. Conclusions: The participants were able to successfully estimate the doses and to provide important information on the exposure scenarios under conditions closely resembling a real-life situation.

Radiation Protection Dosimetry, 2013

In 2011, a serious radiation accident occurred in Stamboliyski, Bulgaria, in an industrial steril... more In 2011, a serious radiation accident occurred in Stamboliyski, Bulgaria, in an industrial sterilisation facility using very-high-activity (60)Co sources. For the five persons accidentally exposed, biological dosimetry based on dicentric analysis was performed in Sofia and in Paris, where the patients were transferred for treatment. Before completing the chromosomal dose assessment, and for the most exposed person, a preliminary cytogenetic evaluation based on electronically transmitted metaphase images was made. The averaged acute whole-body dose estimates for the five patients ranged from 5.2 to 1.2 Gy, and good agreement was obtained between the two laboratories. The patients were also assessed by their prodromal responses and depressed blood cell counts over the first week. The cytogenetic dose estimates were in good accord with those derived from the blood counts, and both techniques indicated that, for the two most seriously exposed persons both techniques indicated that the initial prodromal reactions had suggested somewhat less severe exposure.

Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 2002

Biology of Reproduction, 2002

Research over the past few years has clearly demonstrated that infertile men have an increased fr... more Research over the past few years has clearly demonstrated that infertile men have an increased frequency of chromosome abnormalities in their sperm. These studies have been further corroborated by an increased frequency of chromosome abnormalities in newborns and fetuses from pregnancies established by intracytoplasmic sperm injection. Most studies have considered men with any type of infertility. However, it is possible that some types of infertility have an increased risk of sperm chromosome abnormalities, whereas others do not. We studied 10 men with a specific type of infertility, asthenozoospermia (poor motility), by multicolor fluorescence in situ hybridization analysis to determine whether they had an increased frequency of disomy for chromosomes 13, 21, XX, YY, and XY, as well as diploidy. The patients ranged in age from 28 to 42 yr (mean 34.1 yr); they were compared with 18 normal control donors whose ages ranged from 23 to 58 yr (mean 35.6 yr). A total of 201 416 sperm were analyzed in the men with asthenozoospermia, with a minimum of 10 000 sperm analyzed per chromosome probe per donor. There was a significant increase in the frequency of disomy in men with asthenozoospermia compared with controls for chromosomes 13 and XX. Thus, this study indicates that infertile men with poorly motile sperm but normal concentration have a significantly increased frequency of sperm chromosome abnormalities.

Dentomaxillofacial Radiology, 2007

To evaluate the possible genotoxic effect of radiation exposure for dental diagnostic purposes as... more To evaluate the possible genotoxic effect of radiation exposure for dental diagnostic purposes as measured by the formation of micronuclei. The micronucleus test was applied to buccal epithelium cells, which are target cells for dental radiography. Specimens of exfoliated buccal cells were collected from patients subjected to panoramic radiography. Samples were obtained from 32 patients, 12 male and 20 female, aged from 24 years to 73 years, before and 10+/-2 days after panoramic radiation exposure. No significant increase in the frequency of cells with micronuclei and total number of micronuclei after panoramic tomography was detected. Mean values of buccal cells with micronuclei+/-standard deviation (SD) before and after radiation examination were 2.34+/-1.49% and 2.81+/-1.64%, respectively. A significant correlation between the age of investigated subjects and the initial frequency of micronuclei in buccal cells was observed (r=0.60, P<0.01). Panoramic radiographic examination does not induce micronuclei in target buccal epithelium cells.

The scoring of micronuclei in human peripheral blood lymphocytes is used as a biomarker and dosim... more The scoring of micronuclei in human peripheral blood lymphocytes is used as a biomarker and dosimeter of radiation exposure. In this paper we investigated a dose response curve for micronuclei in human lymphocytes following Cs-137 irradiation in vitro. The lymphocytes were obtained from 7 different donors aged between 24 and 51 years. The applied doses were: 0.0, 0.05, 0.1, 0.25, 0.5, 0.75, 1.0, 1.5, 2.0, 3.0 and 4.0 Gy. There was an increase of micronuclei frequency MN with the dose. The dose-effect relationship was expressed with the following linear-quadratic equation Y = 20,56 + 39,59.D + 17,01.D 2 , where (Y)-represents the micronuclei yield, (D)-represents the applied radiation dose. A software program for absorbed dose assessment based on this equation was created.

Curcumin is a component of natural spice Curcuma longa. It is known that this polyphenol has been... more Curcumin is a component of natural spice Curcuma longa. It is known that this polyphenol has been shown to exhibit anti-inflammatory, anticancer, antiviral, antioxidant and antibacterial activities. The mechanism of curcumin effectiveness on both healthy and cancer tissues is still unclear. Aims: In vitro assessment of curcumin effect on both double-strand breaks and chromosomal translocations frequency, after γ-irradiation. Methods: Human peripheral blood samples were pre-treated with different concentrations of curcumin (0.5 µg/ml; 10 µg/ml; 20 µg/ml and 100 µg/ml). Thereafter they were exposed to 60Co γ-rays using various irradiation doses (0.05 Gy; 0.5 Gy; 1 Gy and 2 Gy). Both γ H2AX/53BP1 foci assay and FISH analysis were used to evaluate DNA double-strand breaks and translocation frequencies. Results: Curcumin pre-treatment exhibited significant lower γ-H2AX/53BP1 foci appearance and reduced translocations frequency in irradiated compared to untreated lymphocytes. At 1 Gy irra...

OBM Genetics, Oct 15, 2018

Background: The purpose of study was to assess the cytogenetic effect of chronic low dose radiati... more Background: The purpose of study was to assess the cytogenetic effect of chronic low dose radiation exposure of nuclear power plant workers using the micronucleus centromere assay. This method allows the differentiation between centromere-positive micronuclei containing whole chromosome and centromere-negative micronuclei containing acentric fragment pointing to clastogenic action of ionizing radiation. Methods: The effect of low dose occupational exposure was estimated in 32 nuclear power plant workers using in situ hybridization (FISH) with the human pancentromeric DNA probe for peripheral blood lymphocytes. Group of 17 persons from the administrative staff served as reference control group. Results: Data on the number of micronuclei, centromere-positive micronuclei and centromere-negative micronuclei per 1000 binucleated cells for the workers were significantly higher compared with the control group (p = 0.001, p=0.01 and p=0.002 respectively). No differences in the studied indicators between smokers and non-smokers

International Journal of Radiation Biology, 2016

Purpose: In the framework of RENEB, several biodosimetry exercises were conducted analyzing diffe... more Purpose: In the framework of RENEB, several biodosimetry exercises were conducted analyzing different endpoints. Among them, the analysis of translocations is considered the most useful method for retrospective biodosimetry due to the relative stability of their frequency with post irradiation time. The aim of this study was to harmonize the accuracy of translocation-based biodosimetry within the RENEB consortium. Materials and methods: An initial telescoring exercise analyzing FISH metaphase images was done to harmonize chromosome aberration descriptions. Then two blind intercomparison exercises (IE) were performed, by sending irradiated blood samples to each partner. Samples were cultured and stained by each partner using their standard protocol and translocation frequency was used to produce dose estimates. Results: The coefficient of variation in the 1st IE (CV ¼ 0.34) was higher than in the 2nd IE (CV ¼ 0.16 and 0.23 in the two samples analyzed), for the genomic frequency of total translocations. Z-score analysis revealed that eight out of 10 and 17 out of 20 dose estimates were satisfactory in the 1st and 2nd IE, respectively. Conclusions: The results obtained indicate that, despite the problems identified in few partners, which can be corrected, the RENEB consortium is able to carry out retrospective biodosimetry analyzing the frequency of translocations by FISH.

International Journal of Radiation Biology, 2016

Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in ... more Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event. Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners. Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes). Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested.

International journal of radiation biology, Jan 20, 2016

RENEB, 'Realising the European Network of Biodosimetry and Physical Retrospective Dosimetry,&... more 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. 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. 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 fo...

Health Physics, Feb 1, 2010

This paper details the construction of a 137Cs gamma calibration curve that has been established ... more This paper details the construction of a 137Cs gamma calibration curve that has been established for dicentric assay and the testing and validation of the curve through biological dosimetry in three situations of suspected workplace overexposure that arose accidentally or through negligence or lack of appropriate safety measures. The three situations were: (1) suspected 137Cs contamination in a factory air supply; (2) suspected exposure to an industrial 192Ir source; and (3) accidental exposure of construction workers to radiation from a 60Co radiotherapy source in a hospital medical physics department. From a total of 24 potentially-exposed subjects, only one worker was found to have a statistically significant dose (0.16 Gy, 95% confidence intervals 0.02-0.43 Gy). In all other cases, the main function of the biological dosimetry was to reassure the subjects that any dose received was low.

Radiation Research

After large-scale radiation accidents where many individuals are suspected to be exposed to ioniz... more After large-scale radiation accidents where many individuals are suspected to be exposed to ionizing radiation, biological and physical retrospective dosimetry assays are important tools to aid clinical decision making by categorizing individuals into unexposed/minimally, moderately or highly exposed groups. Quality-controlled inter-laboratory comparisons of simulated accident scenarios are regularly performed in the frame of the European legal association RENEB (Running the European Network of Biological and Physical retrospective Dosimetry) to optimize international networking and emergency readiness in case of large-scale radiation events. In total 33 laboratories from 22 countries around the world participated in the current RENEB inter-laboratory comparison 2021 for the dicentric chromosome assay. Blood was irradiated in vitro with X rays (240 kVp, 13 mA, ∼75 keV, 1 Gy/min) to simulate an acute, homogeneous whole-body exposure. Three blood samples (no. 1: 0 Gy, no. 2: 1.2 Gy, n...

Radiation Protection Dosimetry, 2014

In the event of a mass casualty radiation incident, the gamma-H2AX foci assay could be a useful t... more In the event of a mass casualty radiation incident, the gamma-H2AX foci assay could be a useful tool to estimate radiation doses received by individuals. The rapid processing time of blood samples of just a few hours and the potential for batch processing, enabling high throughput, make the assay ideal for early triage categorisation to separate the 'worried well' from the low and critically exposed by quantifying radiation-induced foci in peripheral blood lymphocytes. Within the RENEB framework, 8 European laboratories have taken part in the first European gamma-H2AX biodosimetry exercise, which consisted of a telescoring comparison of 200 circulated foci images taken from 8 samples, and a comparison of 10 fresh blood lymphocyte samples that were shipped overnight to participating labs 4 or 24 h post-exposure. Despite large variations between laboratories in the doseresponse relationship for foci induction, the obtained results indicate that the network should be able to use the gamma-H2AX assay for rapidly identifying the most severely exposed individuals within a cohort who could then be prioritised for accurate chromosome dosimetry.

Journal of Radiation Research

The purpose of the present study is to evaluate the effect of curcumin as a natural compound agai... more The purpose of the present study is to evaluate the effect of curcumin as a natural compound against radiation induced γ-foci and stable chromosome aberrations. Whole blood samples form three human volunteers were pretreated with curcumin at different concentrations (0.5, 10, 20 and 100 μg/ml). After 1-hour incubation, the lymphocytes were exposed to γ-rays (0.05, 0.5, 1 and 2 Gy). Radiation induced changes in cells were quantified using γ-H2AX/53BP1 assay and FISH analysis. Our results have shown that curcumin significantly reduced the frequency of both γ-foci and translocations. We found concentration-dependent increase of curcumin protective effect on γ-H2AX/53BP1 foci formation at all radiation doses. Concerning the translocations, after 0.05 and 0.5 Gy γ-rays the values of genomic frequencies are comparable within each dose and we did not observe any impact of curcumin. The most protective effect after 1 Gy exposure was found at 100 μg/ml curcumin. At 2 Gy irradiation, the maxi...

International Journal of Radiation Biology, 2021

Purpose: Biological and/or physical assays for retrospective dosimetry are valuable tools to reco... more Purpose: Biological and/or physical assays for retrospective dosimetry are valuable tools to recover the exposure situation and to aid medical decision making. To further validate and improve such biological and physical assays, in 2019, EURADOS Working Group 10 and RENEB performed a field exercise in Lund, Sweden, to simulate various real-life exposure scenarios. Materials and methods: For the dicentric chromosome assay (DCA), blood tubes were located at anthropomorphic phantoms positioned in different geometries and were irradiated with a 1.36 TBq 192 Ir-source. For each exposure condition, dose estimates were provided by at least one laboratory and for four conditions by 17 participating RENEB laboratories. Three radio-photoluminescence glass dosimeters were placed at each tube to assess reference doses. Results: The DCA results were homogeneous between participants and matched well with the reference doses (!95% of estimates within ±0.5 Gy of the reference). For samples close to the source systematic underestimation could be corrected by accounting for exposure time. Heterogeneity within and between tubes was detected for reference doses as well as for DCA doses estimates. Conclusions: The participants were able to successfully estimate the doses and to provide important information on the exposure scenarios under conditions closely resembling a real-life situation.

Radiation Protection Dosimetry, 2013

In 2011, a serious radiation accident occurred in Stamboliyski, Bulgaria, in an industrial steril... more In 2011, a serious radiation accident occurred in Stamboliyski, Bulgaria, in an industrial sterilisation facility using very-high-activity (60)Co sources. For the five persons accidentally exposed, biological dosimetry based on dicentric analysis was performed in Sofia and in Paris, where the patients were transferred for treatment. Before completing the chromosomal dose assessment, and for the most exposed person, a preliminary cytogenetic evaluation based on electronically transmitted metaphase images was made. The averaged acute whole-body dose estimates for the five patients ranged from 5.2 to 1.2 Gy, and good agreement was obtained between the two laboratories. The patients were also assessed by their prodromal responses and depressed blood cell counts over the first week. The cytogenetic dose estimates were in good accord with those derived from the blood counts, and both techniques indicated that, for the two most seriously exposed persons both techniques indicated that the initial prodromal reactions had suggested somewhat less severe exposure.

Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 2002

Biology of Reproduction, 2002

Research over the past few years has clearly demonstrated that infertile men have an increased fr... more Research over the past few years has clearly demonstrated that infertile men have an increased frequency of chromosome abnormalities in their sperm. These studies have been further corroborated by an increased frequency of chromosome abnormalities in newborns and fetuses from pregnancies established by intracytoplasmic sperm injection. Most studies have considered men with any type of infertility. However, it is possible that some types of infertility have an increased risk of sperm chromosome abnormalities, whereas others do not. We studied 10 men with a specific type of infertility, asthenozoospermia (poor motility), by multicolor fluorescence in situ hybridization analysis to determine whether they had an increased frequency of disomy for chromosomes 13, 21, XX, YY, and XY, as well as diploidy. The patients ranged in age from 28 to 42 yr (mean 34.1 yr); they were compared with 18 normal control donors whose ages ranged from 23 to 58 yr (mean 35.6 yr). A total of 201 416 sperm were analyzed in the men with asthenozoospermia, with a minimum of 10 000 sperm analyzed per chromosome probe per donor. There was a significant increase in the frequency of disomy in men with asthenozoospermia compared with controls for chromosomes 13 and XX. Thus, this study indicates that infertile men with poorly motile sperm but normal concentration have a significantly increased frequency of sperm chromosome abnormalities.

Dentomaxillofacial Radiology, 2007

To evaluate the possible genotoxic effect of radiation exposure for dental diagnostic purposes as... more To evaluate the possible genotoxic effect of radiation exposure for dental diagnostic purposes as measured by the formation of micronuclei. The micronucleus test was applied to buccal epithelium cells, which are target cells for dental radiography. Specimens of exfoliated buccal cells were collected from patients subjected to panoramic radiography. Samples were obtained from 32 patients, 12 male and 20 female, aged from 24 years to 73 years, before and 10+/-2 days after panoramic radiation exposure. No significant increase in the frequency of cells with micronuclei and total number of micronuclei after panoramic tomography was detected. Mean values of buccal cells with micronuclei+/-standard deviation (SD) before and after radiation examination were 2.34+/-1.49% and 2.81+/-1.64%, respectively. A significant correlation between the age of investigated subjects and the initial frequency of micronuclei in buccal cells was observed (r=0.60, P<0.01). Panoramic radiographic examination does not induce micronuclei in target buccal epithelium cells.

The scoring of micronuclei in human peripheral blood lymphocytes is used as a biomarker and dosim... more The scoring of micronuclei in human peripheral blood lymphocytes is used as a biomarker and dosimeter of radiation exposure. In this paper we investigated a dose response curve for micronuclei in human lymphocytes following Cs-137 irradiation in vitro. The lymphocytes were obtained from 7 different donors aged between 24 and 51 years. The applied doses were: 0.0, 0.05, 0.1, 0.25, 0.5, 0.75, 1.0, 1.5, 2.0, 3.0 and 4.0 Gy. There was an increase of micronuclei frequency MN with the dose. The dose-effect relationship was expressed with the following linear-quadratic equation Y = 20,56 + 39,59.D + 17,01.D 2 , where (Y)-represents the micronuclei yield, (D)-represents the applied radiation dose. A software program for absorbed dose assessment based on this equation was created.

Curcumin is a component of natural spice Curcuma longa. It is known that this polyphenol has been... more Curcumin is a component of natural spice Curcuma longa. It is known that this polyphenol has been shown to exhibit anti-inflammatory, anticancer, antiviral, antioxidant and antibacterial activities. The mechanism of curcumin effectiveness on both healthy and cancer tissues is still unclear. Aims: In vitro assessment of curcumin effect on both double-strand breaks and chromosomal translocations frequency, after γ-irradiation. Methods: Human peripheral blood samples were pre-treated with different concentrations of curcumin (0.5 µg/ml; 10 µg/ml; 20 µg/ml and 100 µg/ml). Thereafter they were exposed to 60Co γ-rays using various irradiation doses (0.05 Gy; 0.5 Gy; 1 Gy and 2 Gy). Both γ H2AX/53BP1 foci assay and FISH analysis were used to evaluate DNA double-strand breaks and translocation frequencies. Results: Curcumin pre-treatment exhibited significant lower γ-H2AX/53BP1 foci appearance and reduced translocations frequency in irradiated compared to untreated lymphocytes. At 1 Gy irra...

OBM Genetics, Oct 15, 2018

Background: The purpose of study was to assess the cytogenetic effect of chronic low dose radiati... more Background: The purpose of study was to assess the cytogenetic effect of chronic low dose radiation exposure of nuclear power plant workers using the micronucleus centromere assay. This method allows the differentiation between centromere-positive micronuclei containing whole chromosome and centromere-negative micronuclei containing acentric fragment pointing to clastogenic action of ionizing radiation. Methods: The effect of low dose occupational exposure was estimated in 32 nuclear power plant workers using in situ hybridization (FISH) with the human pancentromeric DNA probe for peripheral blood lymphocytes. Group of 17 persons from the administrative staff served as reference control group. Results: Data on the number of micronuclei, centromere-positive micronuclei and centromere-negative micronuclei per 1000 binucleated cells for the workers were significantly higher compared with the control group (p = 0.001, p=0.01 and p=0.002 respectively). No differences in the studied indicators between smokers and non-smokers

International Journal of Radiation Biology, 2016

Purpose: In the framework of RENEB, several biodosimetry exercises were conducted analyzing diffe... more Purpose: In the framework of RENEB, several biodosimetry exercises were conducted analyzing different endpoints. Among them, the analysis of translocations is considered the most useful method for retrospective biodosimetry due to the relative stability of their frequency with post irradiation time. The aim of this study was to harmonize the accuracy of translocation-based biodosimetry within the RENEB consortium. Materials and methods: An initial telescoring exercise analyzing FISH metaphase images was done to harmonize chromosome aberration descriptions. Then two blind intercomparison exercises (IE) were performed, by sending irradiated blood samples to each partner. Samples were cultured and stained by each partner using their standard protocol and translocation frequency was used to produce dose estimates. Results: The coefficient of variation in the 1st IE (CV ¼ 0.34) was higher than in the 2nd IE (CV ¼ 0.16 and 0.23 in the two samples analyzed), for the genomic frequency of total translocations. Z-score analysis revealed that eight out of 10 and 17 out of 20 dose estimates were satisfactory in the 1st and 2nd IE, respectively. Conclusions: The results obtained indicate that, despite the problems identified in few partners, which can be corrected, the RENEB consortium is able to carry out retrospective biodosimetry analyzing the frequency of translocations by FISH.

International Journal of Radiation Biology, 2016

Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in ... more Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event. Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners. Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes). Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested.

International journal of radiation biology, Jan 20, 2016

RENEB, 'Realising the European Network of Biodosimetry and Physical Retrospective Dosimetry,&... more 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. 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. 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 fo...

Health Physics, Feb 1, 2010

This paper details the construction of a 137Cs gamma calibration curve that has been established ... more This paper details the construction of a 137Cs gamma calibration curve that has been established for dicentric assay and the testing and validation of the curve through biological dosimetry in three situations of suspected workplace overexposure that arose accidentally or through negligence or lack of appropriate safety measures. The three situations were: (1) suspected 137Cs contamination in a factory air supply; (2) suspected exposure to an industrial 192Ir source; and (3) accidental exposure of construction workers to radiation from a 60Co radiotherapy source in a hospital medical physics department. From a total of 24 potentially-exposed subjects, only one worker was found to have a statistically significant dose (0.16 Gy, 95% confidence intervals 0.02-0.43 Gy). In all other cases, the main function of the biological dosimetry was to reassure the subjects that any dose received was low.