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The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements., authorCount :31

This paper presents the results of the 4th International Comparison of in vitro electron paramagnetic resonance dosimetry with tooth enamel, where the performance parameters of tooth enamel dosimetry methods were compared among sixteen laboratories from all over the world. The participating laboratories were asked to determine a calibration curve with a set of tooth enamel powder samples provided by the organizers. Nine molar teeth extracted following medical indication from German donors and collected between 1997 and 2007 were prepared and irradiated at the Helmholtz Zentrum Munchen. Five out of six samples were irradiated at 0.1, 0.2, 0.5, 1.0 and 1.5 Gy air kerma; and one unirradiated sample was kept as control. The doses delivered to the individual samples were unknown to the participants, who were asked to measure each sample nine times, and to report the EPR signal response, the mass of aliquots measured, and the parameters of EPR signal acquisition and signal evaluation. Critical dose and detection limit were calculated by the organizers on the basis of the calibration-curve parameters obtained at every laboratory. For calibration curves obtained by measuring every calibration sample three times, the mean value of the detection limit was 205 mGy, ranging from 56 to 649 mGy. The participants were also invited to provide the signal response and the nominal dose of their current dose calibration curve (wherever available), the critical dose and detection limit of which were also calculated by the organizers., Funding Agencies|EC project SOUL|FIP6R-516478

The retina is a highly compiex nervous tissue containing two stages of synaptic layers and at least five types of cells. The electrical response of the retina, recorded by the electrorctinogram (ERG), reflects the complexity of the anatomicai connection in the retina. When a flash of light fails on the retina, the ERG records the change of the retinai potential from the resting potentiai generated at the junction between the photoreceptors and the pigment epithelium. It consists of various components which arise in different layers of the retina. We analyse the temporal aspects of three components of the seven recordable eiectricai potentials evoked by a flash of light: the a- and b-waves, and the OPs. The a-wave is generated along a radial path from the cell body of the photoreceptors into the membrane of the outer segments and is an important component of the clinical ERG as a measure of photoreceptos activity. The a-wave consists of several components arising from cones and rods. The b-wave originates, probabiy, in Muller cells which reflect extracellular current spread due to potassium concentration changes caused by the depolarising activity and is expression of post-synaptic summed neuronal activities and thus is an important measure. The b-wave implicit time is a good indicator of receptor sensitivity and hence it correlates with the Naka-Rushton parameters. The osciiiatory potentials (OPs) of the electroretinograrn (ERG) are small waves superimposed on the b-wave of the ERG. It seems that their generators are probably located at inner plexiform layer and can reflect the activity of inhibitory feedback circuits strictly dependent on the retinal circulation. For this reason the OPs have a considerable clinical interest even if until now there is a great deal of disagreement about their measurement and analysis. The OP analysis in the frequency domain gives a measurement of the energy content and of the dominating frequency. The OPs were analysed in time and fr

The retina is a highly compiex nervous tissue containing two stages of synaptic layers and at least five types of cells. The electrical response of the retina, recorded by the electrorctinogram (ERG), reflects the complexity of the anatomicai connection in the retina. When a flash of light fails on the retina, the ERG records the change of the retinai potential from the resting potentiai generated at the junction between the photoreceptors and the pigment epithelium. It consists of various components which arise in different layers of the retina. We analyse the temporal aspects of three components of the seven recordable eiectricai potentials evoked by a flash of light: the a- and b-waves, and the OPs. The a-wave is generated along a radial path from the cell body of the photoreceptors into the membrane of the outer segments and is an important component of the clinical ERG as a measure of photoreceptos activity. The a-wave consists of several components arising from cones and rods. The b-wave originates, probabiy, in Muller cells which reflect extracellular current spread due to potassium concentration changes caused by the depolarising activity and is expression of post-synaptic summed neuronal activities and thus is an important measure. The b-wave implicit time is a good indicator of receptor sensitivity and hence it correlates with the Naka-Rushton parameters. The osciiiatory potentials (OPs) of the electroretinograrn (ERG) are small waves superimposed on the b-wave of the ERG. It seems that their generators are probably located at inner plexiform layer and can reflect the activity of inhibitory feedback circuits strictly dependent on the retinal circulation. For this reason the OPs have a considerable clinical interest even if until now there is a great deal of disagreement about their measurement and analysis. The OP analysis in the frequency domain gives a measurement of the energy content and of the dominating frequency. The OPs were analysed in time and fr