Retour d’expérience sur les évènements déclarés à l’Autorité de sûreté nucléaire (ASN) dans le domaine médical

The ASN launched in July 2007 a system of notification of significant events dealing with ionising radiation, called ESRs. The ESRs notified to the ASN in the medical field have been increasing since 2007 and amounted to a total of 2300. The information showed that the medical activities with the most important implications for radiation protection regarding professionals are interventional radiology, with dose limit overruns, brachytherapy and nuclear medicine, with internal contamination of operators. For patients, deterministic effects were observed in interventional radiology as well as large doses in nuclear medicine, when the process of issuing radiopharmaceuticals is not managed, with the worst ESR being a partial removal of the thyroid. Many events involve leaks of radioactive waste and emphasise the need to strengthen the maintenance and monitoring facilities, and can cause major disruptions of service with delays in the delivery of care. The feedback emphasises the importance of empowering medical physicists and radiation protection officers to implement steps of quality management and risk management as well as clinical audits

Combination of iron overload plus ethanol and ischemia alone give rise to the same endogenous free iron pool.

Iron overload aggravates tissue damage caused by ischemia and ethanol intoxication. The underlying mechanisms of this phenomenon are not yet clear. To clarify these mechanisms we followed free iron (loosely bound redox-active iron) concentration in livers from rats subjected to experimental iron overload, acute ethanol intoxication, and ex vivo warm ischemia. The levels of free iron in non-homogenized liver tissues, liver homogenates, and hepatocyte cultures were analyzed by means of EPR spectroscopy. Ischemia gradually increased the levels of endogenous free iron in liver tissues and in liver homogenates. The increase was accompanied by the accumulation of lipid peroxidation products. Iron overload alone, known to increase significantly the total tissue iron, did not affect either free iron levels or lipid peroxidation. Homogenization of iron-loaded livers, however, resulted in the release of a significant portion of free iron from endogenous depositories. Acute ethanol intoxication increased free iron levels in liver tissue and diminished the portion of free iron releasing during homogenization. Similarly to liver tissue, the primary hepatocyte culture loaded with iron in vitro released significantly more free iron during homogenization compared to non iron-loaded hepatocyte culture. Analyzing three possible sources of free iron release under these experimental conditions in liver cells, namely ferritin, intracellular transferrin-receptor complex and heme oxygenase, we suggest that redox active free iron is released from ferritin under ischemic conditions whereas ethanol and homogenization facilitate the release of iron from endosomes containing transferrin-receptor complexes

On the potential effect of increased dietary intake of fruits and vegetables on biomarkers of lipid peroxidation intype 2 diabetes patients

The present study was designed to test the hypothesis that an increased consumption of fruits and vegetables up to 600 g per day in type 2 diabetes patients can reduce oxidative damages to lipids. After a clinical examination, 29 type 2 diabetes patients were divided into two groups: the first one did not receive any special instructions about the diet while the second one received fruits and vegetables consumption advices thanks to a picture catalogue describing types of fruits and vegetables as well as quantities to be eaten every day. After two months of intervention, plasma concentrations in vitamin C, β-carotene and polyphenols remained unchanged in both groups when compared to baseline values. No significant decrease in lipid peroxidation as evidenced by nine biomarkers (malonaldehyde as TBAR's, lipid peroxides, oxidized LDL, antibodies against oxidized LDL, isoprostanes, 7-keto-cholesterol, 7β- hydroxycholesterol, 4-hydroxynonenal metabolite, LDL size) was also noted. In conclusion, our findings confirmed the fact that the effect of high intake of fruits and vegetables on reducing oxidative damage to lipids remains largely controversial even in patients having an oxidative stress profile. Moreover, the present leaves open the question of the most appropriate markers of lipid peroxidation since only small correlations were evidenced between the large battery of tests investigated. © 2013 Lifescience Global.The present study was designed to test the hypothesis that an increased consumption of fruits and vegetables up to 600 g per day in type 2 diabetes patients can reduce oxidative damages to lipids. After a clinical examination, 29 type 2 diabetes patients were divided into two groups: the first one did not receive any special instructions about the diet while the second one received fruits and vegetables consumption advices thanks to a picture catalogue describing types of fruits and vegetables as well as quantities to be eaten every day. After two months of intervention, plasma concentrations in vitamin C, β-carotene and polyphenols remained unchanged in both groups when compared to baseline values. No significant decrease in lipid peroxidation as evidenced by nine biomarkers (malonaldehyde as TBAR's, lipid peroxides, oxidized LDL, antibodies against oxidized LDL, isoprostanes, 7-keto-cholesterol, 7β- hydroxycholesterol, 4-hydroxynonenal metabolite, LDL size) was also noted. In conclu