Joint research towards a better radiation protection-highlights of the Fifth MELODI Workshop.

MELODI is the European platform dedicated to low-dose radiation risk research. From 7 October through 10 October 2013 the Fifth MELODI Workshop took place in Brussels, Belgium. The workshop offered the opportunity to 221 unique participants originating from 22 countries worldwide to update their knowledge and discuss radiation research issues through 118 oral and 44 poster presentations. In addition, the MELODI 2013 workshop was reaching out to the broader radiation protection community, rather than only the low-dose community, with contributions from the fields of radioecology, emergency and recovery preparedness, and dosimetry. In this review, we summarise the major scientific conclusions of the workshop, which are important to keep the MELODI strategic research agenda up-to-date and which will serve to establish a joint radiation protection research roadmap for the future.

The role of combined assessment of defense against oxidative stress and inflammation in the evaluation of peripheral arterial disease.

Atherosclerosis in symptomatic peripheral arterial disease affects wide portions of numerous arteries in lower extremities. The resulting active inflammation in a considerable amount of arterial tissue facilitates systemic detection via measurement of inflammation-related variables. We reasoned that the combined assessment of defense against oxidative stress, in the form of paraoxonase-1 (PON1), and monocyte migration measured as circulating (C-C motif) ligand 2 (CCL2), may play a role in the evaluation of these patients. Plasma CCL2 and serum PON1-related variables, assessed by their interaction with functional genetic variants, were measured in a cross-sectional study in patients with symptomatic PAD. We found that PON1 activity and concentration were significantly lower and CCL2 concentration higher in PAD patients compared to controls, that the combination of plasma CCL2 and PON1- related values, especially PON1 concentration differentiated, almost perfectly, controls from patients and that the expression of CCL2 and PON1 generally co-localized in the atherosclerotic lesion. Since no association with genetic variants was found, such a relationship is probably the result of the disease. Our data suggest a coordinated role between CCL2 and PON1 that may be detected in blood with simple measurements and may represent an indicator of the extent of atherosclerosis.

In vivo diagnostic assessment of dentinal caries by junior and senior students using red acid dye.

The aim of this study was firstly to determine and compare the ability of inexperienced junior dental students (Fourth-year) and senior students (Fifth-year) versus a dental school instructor to identify demineralized dentine with the aid of a caries-disclosing solution and secondly to evaluate an eventual improvement of the caries diagnosis accuracy of junior (Fourth-year) and senior (Fifth-year) dental students. Three successive stages were used to check the ability of the dental students to diagnose and excavate the de-mineralized dentine. This study pointed out that 96% of junior dental students versus a teacher failed to remove all of the demineralized dentine without the use of a caries detector at the first stage and 79% at the second stage in the same condition. 100% of senior students versus a teacher, also failed to diagnose dental caries without a caries detector, but only at the first stage. However, at the second stage, unlike the junior students, all of the senior students were able to remove all of the demineralized dentine. Without the use of a caries detector dye, the risks of the dental students leaving demineralized dentine are high. This technique may be particularly helpful for the fourth-year students who are performing their first restorative treatment.

Aspects of performance assessment of whole body imaging systems.

Regular quality control is one of the cornerstones of nuclear medicine and a prerequisite for adequate diagnostic imaging. Many papers have been published on quality control of planar and tomographic imaging systems. Up to now, however, only minor attention has been given to the assessment of the performance of whole body imaging systems. In this paper we present a comprehensive set of test procedures including acceptance testing and regular quality control. It is not our purpose to present a thorough analysis of the methods and results. The selection of the tests is discussed and the tests are described; some results are presented. In addition action thresholds are proposed. The quality control tests can be applied to systems with either a moving detector or a moving imaging table, and to both detectors with a large field of view and detectors with a small field of view. The tests presented in this paper do not require special phantoms or sources other than those used for quality control of stationary gamma cameras. They can be applied for acceptance testing and for performance testing in a regular quality assurance programme.

Assessment of peripheral vascular effects of antimigraine drugs in humans.

The vascular beds of the forearm and finger can be used to study the peripheral effects of antimigraine drugs under normal and pathologic circumstances. We have investigated the novel antimigraine drug sumatriptan, a selective agonist for 5HT1 receptors. Its antimigraine effect may be attributed, at least in part, to constriction of cranial arteriovenous anastomoses (AVAs). In assessing the peripheral vascular effects of sumatriptan we used a forearm and finger blood flow model. Forearm blood flow (FBF) is mainly determined by resistance vessels, whereas finger blood flow (FiBF) mainly involves skin vessels, which contain many AVAs. Changes in FBF and FiBF can be assessed using venous occlusion plethysmography. Changes in AVA flow are determined by measuring the patency of the vascular beds of the forearm and hand to well-defined radiolabelled microspheres, which are injected into the brachial artery. We report the effects of sumatriptan on FBF, FiBF and AVA flow when administered into the brachial artery of healthy volunteers, and discuss the peripheral vascular effects of therapeutic doses of sumatriptan when given subcutaneously in migraine patients during and between attacks.

Detection of hepatitis C virus antibodies with new recombinant antigens: assessment in chronic liver diseases.

A new serological assay to detect antibodies against hepatitis C, based on a recombinant protein (BHC10) which incorporates structural and non-structural viral antigens, was tested in 67 healthy subjects and 409 patients with various forms of liver disease. Results were compared with the current assay based on the recombinant non-structural viral antigen c100 and with the recently introduced second-generation assay, Ortho2. None of the healthy subjects was positive by any of the assays. In patients with chronic non-A, non-B hepatitis the prevalence of anti-BHC10 was 96.8%, higher than anti-c100 (83.3%, p less than 0.001) and similar to Ortho2 (94.3%). False-positive results were less frequently found when BHC10 was used. These findings show that assays incorporating structural and non-structural antigens provide higher sensitivity to detect hepatitis C virus infection and they define an almost exclusive role of hepatitis C virus in the genesis of chronic non-A, non-B hepatitis.

Urine ethanol assessment: a helpful method for controlling abstinence in alcoholic liver disease.

The usefulness of a urine-alcohol determination in the evaluation of abstinence in alcoholic liver disease has been investigated in 181 patients. Alcohol was tested in morning urine samples collected on a follow-up visit in 103 patients, and the results were compared with those in 78 patients, where three samples were collected within the same week; one in the morning and two in the evening. Although the percentage of urine samples containing alcohol measured in a morning sample was similar to the patients' self-report (31% and 34%, respectively), urine analysis identified an additional 7% of patients who denied alcohol intake. Alternatively, serial urine-alcohol determinations were significantly more effective than patient reports (54% and 35.9%, respectively, P less than 0.01), particularly when urine was collected in the evenings. This difference was due mainly to the reluctance of women to admit drinking (7.4% of positive self reports vs 51% of women with alcohol positive urine samples, P less than 0.001). We conclude that serial measurements of alcohol in urine were useful tests which should be used to complement personal interview in the control of abstinence in patients with alcoholic liver disease.