20 research outputs found

    RENEB accident simulation exercise

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    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

    Dose assessment intercomparisons within the RENEB network using G0-lymphocyte prematurely condensed chromosomes (PCC assay)

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    Purpose: Dose assessment intercomparisons within the RENEB network were performed for triage biodosimetry analyzing G0-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 c-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 24 h 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 G0-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

    Integration of new biological and physical retrospective dosimetry methods into EU emergency response plans : joint RENEB and EURADOS inter-laboratory comparisons

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    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

    DNA content alterations in Tetrahymena pyriformis macronucleus after exposure to food preservatives sodium nitrate and sodium benzoate

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    The toxicity, in terms of changes in the DNA content, of two food preservatives, sodium nitrate and sodium benzoate was studied on the protozoan Tetrahymena pyriformis using DNA image analysis technology. For this purpose, selected doses of both food additives were administered for 2 h to protozoa cultures and DNA image analysis of T. pyriformis nuclei was performed. The analysis was based on the measurement of the Mean Optical Density which represents the cellular DNA content. The results have shown that after exposure of the protozoan cultures to doses equivalent to ADI, a statistically significant increase in the macronuclear DNA content compared to the unexposed control samples was observed. The observed increase in the macronuclear DNA content is indicative of the stimulation of the mitotic process and the observed increase in MOD, accompanied by a stimulation of the protozoan proliferation activity is in consistence with this assumption. Since alterations at the DNA level such as DNA content and uncontrolled mitogenic stimulation have been linked with chemical carcinogenesis, the results of the present study add information on the toxicogenomic profile of the selected chemicals and may potentially lead to reconsideration of the excessive use of nitrates aiming to protect public health

    Immunogenic Cell Death, DAMPs and Prothymosin α as a Putative Anticancer Immune Response Biomarker

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    The new and increasingly studied concept of immunogenic cell death (ICD) revealed a previously unknown perspective of the various regulated cell death (RCD) modalities, elucidating their immunogenic properties and rendering obsolete the notion that immune stimulation is solely the outcome of necrosis. A distinct characteristic of ICD is the release of danger-associated molecular patterns (DAMPs) by dying and/or dead cells. Thus, several members of the DAMP family, such as the well-characterized heat shock proteins (HSPs) HSP70 and HSP90, the high-mobility group box 1 protein and calreticulin, and the thymic polypeptide prothymosin α (proTα) and its immunoreactive fragment proTα(100–109), are being studied as potential diagnostic tools and/or possible therapeutic agents. Here, we present the basic aspects and mechanisms of both ICD and other immunogenic RCD forms; denote the role of DAMPs in ICD; and further exploit the relevance of human proTα and proTα(100–109) in ICD, highlighting their possible clinical applications. Furthermore, we present the preliminary results of our in vitro studies, which show a direct correlation between the concentration of proTα/proTα(100–109) and the levels of cancer cell apoptosis, induced by anticancer agents and γ-radiation

    Individual radiation sensitivity and biomarkers : molecular radiation biology

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    In recent years, scientific understanding of the changes radiation makes to the various tissues of the body has vastly increased. Identification of biological markers of radiation exposure and response has become a wide field with an increasing interest across the radiation research community. This chapter introduces the concepts of individual radiosensitivity, radiosusceptibility, and radiodegeneration, which are the key factors to classify radiation responses. Biomarkers are then introduced, and their key characteristics as well as classification are explained, with a particular focus on those biomarkers which have been identified for use in epidemiological studies of radiation risk—as this is a crucial topic of current interest within radiation protection. Brief information on collection of samples is followed by a detailed presentation of predictive assays in use in different settings including clinical applications with responses assessed chiefly in tissue biopsy or blood samples. The sections toward the end of this chapter then discuss the evidence associated with the relationship between age and separately sex, and radiosensitivity, as well as some genetic syndromes associated with radiosensitivity. The final section of this chapter provides a brief summary of how our current knowledge can further support individual, personalized, uses of radiation, particularly in clinical settings

    Salts of Clopidogrel: Investigation to Ensure Clinical Equivalence: A 12-Month Randomized Clinical Trial

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    Background: In the present clinical trial, we compared the efficacy and safety of the generic clopidogrel besylate (CB) with the innovator clopidogrel hydrogen sulfate (CHS) salt in patients eligible to receive clopidogrel. Methods: A prospective 2-arm, multicenter, open-label, phase 4 clinical trial. Consecutive patients (n = 1864) were screened and 1800 were enrolled in the trial and randomized to CHS or CB. Primary efficacy end point was the composite of myocardial infarction, stroke, or death from vascular causes, and primary safety end point was rate of bleeding events as defined by Bleeding Academic Research Consortium criteria. Results: At 12-month follow-up, no differences were observed between CB (n = 759) and CHS (n = 798) in primary efficacy and safety end points (age, sex, history of percutaneous coronary intervention adjusted odds ratio [OR], 0.70; 95% confidence interval [CI], 0.41-1.21 and OR, 0.81; 95% CI, 0.51-1.29, respectively) between CHS and CB. Analyses of efficacy and safety in subgroups that were defined according to the qualifying diagnosis revealed that there was no difference between CHS and CB. Conclusion: The efficacy and safety of CB administered for 12 months for the secondary prevention of atherothrombotic events are similar to that of CHS

    Generic Clopidogrel Besylate in the Secondary Prevention of Atherothrombotic Events: A 6-month Follow-up of a Randomised Clinical Trial

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    Background: The aim of the present interim analysis was to compare the clinical efficacy and safety of the generic clopidogrel besylate (CB) with the innovator clopidogrel hydrogen sulphate (CHS) salt in patient groups eligible to receive clopidogrel. Methods: A 2-arm, multicenter, open-label, phase IV clinical trial. Consecutive patients (n=1,864) were screened and 1,800 were enrolled in the trial and randomized to CHS (n=759) or CB (n=798). Primary efficacy end point was the composite of myocardial infarction, stroke or death from vascular causes. Primary safety end point was the rate of bleeding events as defined by Bleeding Academic Research Consortium (BARC) criteria. Results: At 6-months follow-up no differences were observed between CB and CHS in primary efficacy end point (OR, 0.80; 95% CI, 0.37 to 1.71; p=0.57). Rates of BARC-1,-2,-3a and -5b bleeding were similar between the two study groups whereas no bleeding events according to BARC-3b, -3c, -4 and -5a were observed in either CHS or CB group. Conclusion: The clinical efficacy and safety of the generic CB were similar to those of the innovator CHS salt, thus this generic clopidogrel formulation can be routinely used in the secondary prevention of atherothrombotic events for a period of at least 6 months. (Salts of Clopidogrel: Investigation to ENsure Clinical Equivalence, SCIENCE study Clinical Trials.gov Identifier: NCT02126982)

    Interlaboratory comparison of dicentric chromosome assay using electronically transmitted images

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    The bottleneck in data acquisition during biological dosimetry based on a dicentric assay is the need to score dicentrics in a large number of lymphocytes. One way to increase the capacity of a given laboratory is to use the ability of skilled operators from other laboratories. This can be done using image analysis systems and distributing images all around the world. Two exercises were conducted to test the efficiency of such an approach involving 10 laboratories. During the first exercise (E1), the participant laboratories analysed the same images derived from cells exposed to 0.5 and 3 Gy; 100 images were sent to all participants for both doses. Whatever the dose, only about half of the cells were complete with well-spread metaphases suitable for analysis. A coefficient of variation (CV) on the standard deviation of ̃15 % was obtained for both doses. The trueness was better for 3 Gy (0.6 %) than for 0.5 Gy (37.8 %). The number of estimated doses classified as satisfactory according to the z-score was 3 at 0.5 Gy and 8 at 3 Gy for 10 dose estimations. In the second exercise, an emergency situation was tested, each laboratory was required to score a different set of 50 images in 2 d extracted from 500 downloaded images derived from cells exposed to 0.5 Gy. Then the remaining 450 images had to be scored within a week. Using 50 different images, the CVon the estimated doses (79.2 %) was not as good as in E1, probably associated to a lower number of cells analysed (50 vs. 100) or from the fact that laboratories analysed a different set of images. The trueness for the dose was better after scoring 500 cells (22.5 %) than after 50 cells (26.8 %). For the 10 dose estimations, the number of doses classified as satisfactory according to the z-score was 9, for both 50 and 500 cells. Overall, the results obtained support the feasibility of networking using electronically transmitted images. However, before its implementation some issues should be elucidated, such as the number and resolution of the images to be sent, and the harmonisation of the scoring criteria. Additionally, a global website able to be used for the different regional networks, like Share Points, will be desirable to facilitate worldwide communication.Fil: García, O.. Centro de Protección e Higiene de las Radiaciones; CubaFil: Di Giorgio, Marina. Autoridad Regulatoria Nuclear. Gerencia Apoyo Científico Técnico; ArgentinaFil: Vallerga, María Belén. Autoridad Regulatoria Nuclear. Gerencia Apoyo Científico Técnico; ArgentinaFil: Radl, Analía. Autoridad Regulatoria Nuclear. Gerencia Apoyo Científico Técnico; ArgentinaFil: Taja, María Rosa. Autoridad Regulatoria Nuclear. Gerencia Apoyo Científico Técnico; ArgentinaFil: Seoane, Analia Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: de Luca, Julio Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Stuck Oliveira, Mónica. Instituto de Radioprotección y Dosimetría; BrasilFil: Valdivia, Patricia. Comision Chilena de Energia Nuclear; ChileFil: Lamadrid, Ana Ilsa. Centro de Proteccion E Higiene de Las Radiaciones; CubaFil: González, Jorge Ernesto. Centro de Proteccion E Higiene de Las Radiaciones; CubaFil: Romero, I.. Centro de Proteccion E Higiene de Las Radiaciones; CubaFil: Mandina, Tania. Centro de Proteccion E Higiene de Las Radiaciones; CubaFil: Pantelias, G.. National Center For Scientific Research ‘demokritos’; GreciaFil: Terzoudi, G.. National Center For Scientific Research ‘demokritos’; GreciaFil: Guerrero Carbajal, Citlalo. Instituto Nacional de Investigaciones Nucleares; MéxicoFil: Arceo Maldonado, Carolina. Instituto Nacional de Investigaciones Nucleares; MéxicoFil: Espinoza, Marco. Instituto Peruano de Energia Nuclear; PerúFil: Oliveros, Nilda. Universidad Nacional Mayor de San Marcos; PerúFil: Martinez Lopez, Wilner. Instituto Investigaciones Biologicas Clemente Estable; UruguayFil: Di Tomasso, Maria Vittoria. Instituto Investigaciones Biologicas Clemente Estable; UruguayFil: Mendez, Leticia Jesica. Instituto Investigaciones Biologicas Clemente Estable; UruguayFil: Puig, Nora Raquel. Universitat Autònoma de Barcelona; EspañaFil: Roy, Laurence. Institut de Radioprotection Et de Surete Nucleaire; FranciaFil: Barquinero, J.F.. Institut de Radioprotection Et de Surete Nucleaire; Franci

    Effect of cocaine and crack on the ploidy status of Tetrahymena pyriformis: a study using DNA image analysis

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    The effect of cocaine and crack on the ploidy status of Feulgen-stained Tetrahymena pyriformis macronuclei using computerized DNA image analysis system was tested. For this purpose, selected doses of 5, 10 and 20 μg (per mL culture) of both drugs were administered for 2, 5 and 20 h to protozoa cultures and DNA image analysis of T. pyriformis nuclei was performed. The analysis was based on the measurement of the following parameters: Ploidy Balance (PB), Degree of Aneuploidy (DA), skewness and kurtosis. The results have shown a positive effect of both cocaine and crack on PB and on DA of T. pyriformis macronuclei. In particular, our results reveal that the aneugenic effect (which is expressed as a decrease in PB and an increase in DA) of cocaine on T. pyriformis macronuclei follows a dose-dependent manner, while crack induces aneuploidy in a dose-independent manner. Changes in the PB and DA values would induce a disturbance in the cellular density and heterogeneity of chromatin and the increase in skewness and kurtosis values after exposure of T. pyriformis to both drugs, did confirm this hypothesis. These observations were further correlated with alterations in the chromosomal segregation and with damage in mitotic spindle microtubules observed previously. In this study the impact of cocaine and crack on genomic instability and carcinogenesis was further supported and T. pyriformis can be proposed as a model organism to test the nuclear ploidy status after exposure to harmful chemicals and drugs
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