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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, no. 3: 3.5 Gy) were sent to each participant and the task was to culture samples, to prepare slides and to assess radiation doses based on the observed dicentric yields from 50 manually or 150 semi-automatically scored metaphases (triage mode scoring). Approximately two-thirds of the participants applied calibration curves from irradiations with γ rays and about 1/3 from irradiations with X rays with varying energies. The categorization of the samples in clinically relevant groups corresponding to individuals that were unexposed/minimally (0–1 Gy), moderately (1–2 Gy) or highly exposed (>2 Gy) was successfully performed by all participants for sample no. 1 and no. 3 and by ≥74% for sample no. 2. However, while most participants estimated a dose of exactly 0 Gy for the sham-irradiated sample, the precise dose estimates of the samples irradiated with doses >0 Gy were systematically higher than the corresponding reference doses and showed a median deviation of 0.5 Gy (sample no. 2) and 0.95 Gy (sample no. 3) for manual scoring. By converting doses estimated based on γ-ray calibration curves to X-ray doses of a comparable mean photon energy as used in this exercise, the median deviation decreased to 0.27 Gy (sample no. 2) and 0.6 Gy (sample no. 3). The main aim of biological dosimetry in the case of a large-scale event is the categorization of individuals into clinically relevant groups, to aid clinical decision making. This task was successfully performed by all participants for the 0 Gy and 3.5 Gy samples and by 74% (manual scoring) and 80% (semi-automatic scoring) for the 1.2 Gy sample. Due to the accuracy of the dicentric chromosome assay and the high number of participating laboratories, a systematic shift of the dose estimates could be revealed. Differences in radiation quality (X ray vs. γ ray) between the test samples and the applied dose effect curves can partly explain the systematic shift. There might be several additional reasons for the observed bias (e.g., donor effects, transport, experimental conditions or the irradiation setup) and the analysis of these reasons provides great opportunities for future research. The participation of laboratories from countries around the world gave the opportunity to compare the results on an international level.

Arachidonic acid is one of the most abundant and ubiquitous omega-6 polyunsaturated fatty acid, present in esterified form in the membrane phospholipids of all mammalian cells and released from phospholipids by several phospholipases in response to various activating or inhibitory stimuli. Arachidonic acid is the precursor of a large number of enzymatically and non-enzymatically derived, biologically active autacoids, including prostaglandins (PGs), thromboxane (TX) A(2), leukotrienes, and epoxyeicosatetraenoic acids (collectively called eicosanoids), endocannabinoids and isoprostanes, respectively. Eicosanoids are local modulators of the physiological functions and pathophysiological rotes of blood vessels and platelets. For example, the importance of cyctooxygenase (COX)-1-derived TXA(2) from activated platelets in contributing to primary haemostasis and atherothrombosis is demonstrated in animal and human models by the bleeding complications and cardioprotective effects associated with low-dose aspirin, a selective inhibitor of platelet COX-1. The relevance of vascular COX-2-derived prostacyclin (PGI(2)) in endothelial thromboresistance and atheroprotection is clearly shown by animal and human models and by the adverse cardiovascular effects exerted by COX-2 inhibitors in humans. A vast array of arachidonic acid-transforming enzymes, downstream synthases and isomerases, transmembrane receptors, and specificity in their tissue expression make arachidonic acid metabolism a fine-tuning system of vascular health and disease. Its pharmacological regulation is central in human cardiovascular diseases, as demonstrated by biochemical measurements and intervention trials.

BackgroundGastroprotectant drugs are used for the prevention and treatment of peptic ulcer disease and might reduce its associated complications, but reliable estimates of the effects of gastroprotectants in different clinical settings are scarce. We aimed to examine the effects of proton-pump inhibitors (PPIs), prostaglandin analogues, and histamine-2 receptor antagonists (H2RAs) in different clinical circumstances by doing meta-analyses of tabular data from all relevant unconfounded randomised trials of gastroprotectant drugs. MethodsWe searched MEDLINE and Embase from Jan 1, 1950, to Dec 31, 2015, to identify unconfounded, randomised trials of a gastroprotectant drug (defined as a PPI, prostaglandin analogue, or H2RA) versus control, or versus another gastroprotectant. Two independent researchers reviewed the search results and extracted the prespecified outcomes and key characteristics for each trial. We did meta-analyses of the effects of gastroprotectant drugs on ulcer development, bleeding, and mortality overall, according to the class of gastroprotectant, and according to the individual drug within a gastroprotectant class. FindingsWe identified comparisons of gastroprotectant versus control in 849 trials (142 485 participants): 580 prevention trials (110 626 participants), 233 healing trials (24 033 participants), and 36 trials for the treatment of acute upper gastrointestinal bleeding (7826 participants). Comparisons of one gastroprotectant drug versus another were available in 345 trials (64 905 participants), comprising 160 prevention trials (32 959 participants), 167 healing trials (28 306 participants), and 18 trials for treatment of acute upper gastrointestinal bleeding (3640 participants). The median number of patients in each trial was 78 (IQR 44·0–210·5) and the median duration was 1·4 months (0·9–2·8). In prevention trials, gastroprotectant drugs reduced development of endoscopic ulcers (odds ratio [OR] 0·27, 95% CI 0·25–0·29; phet=0·0005). Gastroprotectant drugs were effective in preventing bleeding irrespective of the use of non-steroidal anti-inflammatory drugs (phet=0·56). In healing trials, gastroprotectants increased endoscopic ulcer healing (3·49, 95% CI 3·28–3·72; phethet=0·0107) and blood transfusion (phet=0·0130). InterpretationGastroprotectants, in particular PPIs, reduce the risk of peptic ulcer disease and its complications and promote healing of peptic ulcers in a wide range of clinical circumstances. However, this meta-analysis might have overestimated the benefits owing to small study bias.

Background: Gastroprotectant drugs are used for the prevention and treatment of peptic ulcer disease and might reduce its associated complications, but reliable estimates of the effects of gastroprotectants in different clinical settings are scarce. We aimed to examine the effects of proton-pump inhibitors (PPIs), prostaglandin analogues, and histamine-2 receptor antagonists (H2RAs) in different clinical circumstances by doing meta-analyses of tabular data from all relevant unconfounded randomised trials of gastroprotectant drugs. Background: Gastroprotectant drugs are used for the prevention and treatment of peptic ulcer disease and might reduce its associated complications, but reliable estimates of the effects of gastroprotectants in different clinical settings are scarce. We aimed to examine the effects of proton-pump inhibitors (PPIs), prostaglandin analogues, and histamine-2 receptor antagonists (H2RAs) in different clinical circumstances by doing meta-analyses of tabular data from all relevant unconfounded randomised trials of gastroprotectant drugs. Methods: We searched MEDLINE and Embase from Jan 1, 1950, to Dec 31, 2015, to identify unconfounded, randomised trials of a gastroprotectant drug (defined as a PPI, prostaglandin analogue, or H2RA) versus control, or versus another gastroprotectant. Two independent researchers reviewed the search results and extracted the prespecified outcomes and key characteristics for each trial. We did meta-analyses of the effects of gastroprotectant drugs on ulcer development, bleeding, and mortality overall, according to the class of gastroprotectant, and according to the individual drug within a gastroprotectant class. Findings: We identified comparisons of gastroprotectant versus control in 849 trials (142 485 participants): 580 prevention trials (110 626 participants), 233 healing trials (24 033 participants), and 36 trials for the treatment of acute upper gastrointestinal bleeding (7826 participants). Comparisons of one gastroprotectant drug versus another were available in 345 trials (64 905 participants), comprising 160 prevention trials (32 959 participants), 167 healing trials (28 306 participants), and 18 trials for treatment of acute upper gastrointestinal bleeding (3640 participants). The median number of patients in each trial was 78 (IQR 44·0–210·5) and the median duration was 1·4 months (0·9–2·8). In prevention trials, gastroprotectant drugs reduced development of endoscopic ulcers (odds ratio [OR] 0·27, 95% CI 0·25–0·29; p

Contemporary medicine is shifting towards person rather than disease-oriented care.1 With increasing life expectancy and the ageing of baby boomers, the proportion over 60 years is growing faster than the overall population, with worldwide estimates reaching 2 billion by 2050 (http://www.un.org/esa/population/publications/worldageing19502050).2 In parallel, acute coronary syndromes (ACS) and atrial fibrillation (AF)—the most frequent indications for dual platelet inhibition or anticoagulation—occur mostly in older patients.2–6 There is general agreement that people ≥75 years can be defined ‘elderly’; however, cutoffs as low as 65 years have been applied to important clinical datasets and risk scores.3,7–10 Moreover, ageing is a continuous process and life-span expansion is deflating (http://www.nber.org/papers/w18407). For these reasons, a threshold to define ‘elderly’ has been intentionally avoided in this document. Of note, over one third of patients admitted with acute myocardial infarction (MI) and two thirds dying from MI are over 75 years, but

background The use of aspirin for the prevention of thrombotic complications in polycythemia vera is controversial. methods We enrolled 518 patients with polycythemia vera, no clear indication for aspirin treatment, and no contraindication to such treatment in a double-blind, placebo-controlled, randomized trial to assess the safety and efficacy of prophylaxis with low-dose aspirin (100 mg daily). The two primary end points were the cumulative rate of nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes and the cumulative rate of nonfatal myocardial infarction, nonfatal stroke, pulmonary embolism, major venous thrombosis, or death from cardiovascular causes. The mean duration of follow-up was about three years. results Treatment with aspirin, as compared with placebo, reduced the risk of the combined end point of nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes (relative risk, 0.41; 95 percent confidence interval, 0.15 to 1.15; P=0.09) and the risk of the combined end point of nonfatal myocardial infarction, nonfatal stroke, pulmonary embolism, major venous thrombosis, or death from cardiovascular causes (relative risk, 0.40; 95 percent confidence interval, 0.18 to 0.91; P=0.03). Overall mortality and cardiovascular mortality were not reduced significantly. The incidence of major bleeding episodes was not significantly increased in the aspirin group (relative risk, 1.62; 95 percent confidence interval, 0.27 to 9.71). conclusions Low-dose aspirin can safely prevent thrombotic complications in patients with polycythemia vera who have no contraindications to such treatment.

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We set up a new denaturing high-performance liquid chromatography (DHPLC)-based protocol to screen patients with autosomal dominant hereditary spastic paraplegia (AD-HSP) for mutations in SPG4. Six patients had a complicated form and 49 a pure HSP phenotype. We also analyzed 19 unrelated patients presenting with an HSP phenotype (pure in 17 and complicated in two subjects) but no clear family history, as such patients may be cases of dominant inheritance with low penetrance. The overall frequency of SPG4 mutations in our study of HSP (in which prior linkage data were unavailable) was 32.4%, rising to 46.9% when only pure AD-HSP patients were considered. This figure falls well within the range reported in different populations. Rather as expected, the clinical data available for the patients did not support an easy genotype-phenotype correlation. Moreover, the clinical picture was not influenced by the length of the predicted residual gene product. As well as identifying novel variants in SPG4, this study constitutes the molecular characterization of the largest cohort of Italian AD-HSP patients studied to date. In addition, it provided an efficient, cost-effective, and reliable detection protocol for mutational screening of SPG4, which might facilitate medical genetic counseling.

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Previous studies have shown that platelet-activating factor (PAF) receptor blocking has a protective effect on rabbit nephrotoxic nephritis (NTN). We examined whether arachidonic acid (AA) metabolism is altered in NTN and whether a PAF receptor antagonist has any influence on such changes. Rabbits injected with anti-glomerular basement membrane antiserum in the heterologous phase had a markedly increased glomerular thromboxane B2 (TxB2) production level, whereas no changes have been detected in glomerular 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and prostaglandin E2 (PGE2). During the autologous phase of the disease, the glomerular TxB2 level was even higher than in the heterologous phase. The level of 6-keto-PGF1 alpha was significantly lower than normal, and the level of PGE2 was unchanged in respect to the basal values. The use of L-652,731 (a specific PAF receptor antagonist) reversed the abnormal generation of AA metabolites at glomerular level both in the heterologous and autologous phase of the disease. The effect of L-652,731 on AA metabolism is likely to be an indirect result of the PAF receptor blocking, because L-652,731 given to normal rabbits had no direct effect on glomerular AA metabolism. To assess whether the beneficial effect of L-652,731 in NTN is at least in part mediated by its capability of suppressing the excessive intrarenal synthesis of thromboxane A2 (TxA2), we compared the effect of L-652,731 with that of a selective TxA2-synthase inhibitor (FCE-22178). FCE-22178 ameliorated the morphologic expression of rabbit NTN and reduced function deterioration. The protective effect of L-652,731 on proteinuria in the autologous phase and on glomerular filtration rate in both phases was superior to that of FCE-22178. We conclude that an excessive intraglomerular synthesis of TxA2 occurs in rabbit NTN that can play a role in renal function deterioration. Both a specific PAF receptor antagonist and a TxA2-synthase inhibitor reduced the exaggerated TxA2 synthesis and favorably influenced the evolution of the disease.

Identification of sequence variants robustly associated with predisposition to diabetic kidney disease (DKD) has the potential to provide insights into the pathophysiological mechanisms responsible. We conducted a genome-wide association study (GWAS) of DKD in type 2 diabetes (T2D) using eight complementary dichotomous and quantitative DKD phenotypes: the principal dichotomous analysis involved 5,717 T2D subjects, 3,345 with DKD. Promising association signals were evaluated in up to 26,827 subjects with T2D (12,710 with DKD). A combined T1D+T2D GWAS was performed using complementary data available for subjects with T1D, which, with replication samples, involved up to 40,340 subjects with diabetes (18,582 with DKD). Analysis of specific DKD phenotypes identified a novel signal near GABRR1 (rs9942471, P = 4.5 × 10-8) associated with microalbuminuria in European T2D case subjects. However, no replication of this signal was observed in Asian subjects with T2D or in the equivalent T1D analysis. There was only limited support, in this substantially enlarged analysis, for association at previously reported DKD signals, except for those at UMOD and PRKAG2, both associated with estimated glomerular filtration rate. We conclude that, despite challenges in addressing phenotypic heterogeneity, access to increased sample sizes will continue to provide more robust inference regarding risk variant discovery for DKD. ASTAR (Agency for Sci., Tech. and Research, S’pore) NMRC (Natl Medical Research Council, S’pore)

Retinal tissue can receive incidental γ-rays exposure during radiotherapy either of tumors of the eye and optic nerve or of head-and-neck tumors, and during medical diagnostic procedures. Healthy retina is therefore at risk of suffering radiation-related side effects and the knowledge of pathophysiological response of retinal cells to ionizing radiations could be useful to design possible strategies of prevention and management of radiotoxicity. In this study, we have exploited an in vitro model (primary rat retinal cell culture) to study an array of biological effects induced on retinal neurons by γ-rays. Most of the different cell types present in retinal tissue - either of the neuronal or glial lineages - are preserved in primary rat retinal cultures. Similar to the retina in situ, neuronal cells undergo in vitro a maturational development shown by the formation of polarized neuritic trees and operating synapses. Since 2 Gy is the incidental dose received by the healthy retina per fraction when the standard treatment is delivered to the brain, retina cell cultures have been exposed to 1 or 2 Gy of γ-rays at different level of neuronal differentiation in vitro: days in vitro (DIV)2 or DIV8. At DIV9, retinal cultures were analyzed in terms of viability, apoptosis and characterized by immunocytochemistry to identify alterations in neuronal differentiation. After irradiation at DIV2, MTT assay revealed an evident loss of cell viability and βIII-tubulin immunostaining highlighted a marked neuritic damage, indicating that survived neurons showed an impaired differentiation. Differentiated cultures (DIV8) appeared to be more resistant with respect to undifferentiated, DIV2 cultures, both in terms of cell viability and differentiation. Apoptosis evaluated with TUNEL assay showed that irradiation at both DIV2 and DIV8 induced a significant increase in the apoptotic rate. To further investigate the effects of γ-rays on retinal neurons, we evaluated the expression of synaptic proteins, such as SNAP25 and synaptophysin. WB and immunofluorescence analysis showed an altered expression of these proteins in particular when cultures were irradiated at DIV2. To evaluate the effect of γ-rays on photoreceptors, we studied the expression of rhodopsin in WB analysis and immunofluorescence. Our results confirm data from the literature that differentiated photoreceptors appear to be more resistant to irradiation respect to other retinal cell types present in cultures. The results obtained suggest that γ-rays exposure of primary retinal cultures may contribute to shed further light on the mechanisms involved in γ-radiation-induced neurodegeneration.

Biological dosimetry is an essential tool for estimating radiation doses received from individuals when the physical dosimetry is not available or inadequate. Early knowledge about the absorbed dose levels in radiation accidents is of paramount importance for selecting the unaffected subjects from those individuals requiring medical evaluation and intervention. A lesson learned from many radiological incidents is the importance to identify the "worried well."Several assays are useful for biological dosimetry approaches, since no one single assay is sufficiently robust for all potential radiation scenarios including early-phase acute exposures, partial-body exposures, and biosampling years after exposure or in case of suspected mixed exposures (radiological and chemicals).The most commonly used biodosimetry methods are based on the evaluation of the radiation-specific dicentric chromosomes (Dic) and micronuclei (MN) in exposed individuals' peripheral blood lymphocytes (PBL).The present chapter does not claim to make an exhaustive and complete picture on the complex world of biodosimetry, to which a large number of specific guidelines for performing laboratory services by the International Organization for Standardization (ISO) are dedicated, but it aims to support the reader in understanding the application of two cytogenetic methods in the individual ionizing radiation dose assessment, suggesting some appropriate scientific sources to consult for each case.

The aim of the 'BioQuaRT' (Biologically weighted Quantities in RadioTherapy) project is to develop measurement techniques for characterising charged particle track structure on different length scales, and to correlate at the cellular level the track structure properties with the biological effects of radiation. This multi-scale approach will allow characterisation of the radiation qualities used in radiotherapy and the related biological effects. Charged-particle microbeam facilities were chosen as the platforms for all radiobiology experiments in the 'BioQuaRT' project, because they allow targeting single cells (or compartments of a cell) with a predefined number of ionising particles and correlating the cell-by-cell induced damage with type and energy of the radiation and with the number of ions per cell. Within this project, a novel in situ protocol was developed for the analysis of the misrepaired and/or unrepaired chromosome damage induced by charged-particle irradiations at the Physikalisch-Technische Bundesanstalt (PTB) ion microbeam facility. Among the cytogenetic biomarkers to detect and estimate radiation-induced DNA damage in radiobiology, chromosomal aberrations and micronuclei were chosen. The characteristics of the PTB irradiation system required the design of a special in situ assay: specific irradiation dishes with a base made from a biofoil 25-μm thick and only 3000-4000 cells seeded and irradiated per dish. This method was developed on Chinese hamster ovary (CHO) cells, one of the most commonly used cell lines in radiobiology in vitro experiments. The present protocol allows the simultaneous scoring of chromosome aberrations and micronuclei on the same irradiated dish. Thanks to its versatility, this method could also be extended to other radiobiological applications besides the single-ion microbeam irradiations. © The Author 2015.

Objective The present study was aimed at characterizing the expression and activity of cyclooxygenase (COX) isoenzymes in erythropoiesis. Methods The expression and activity of cyclooxygenase (COX) and prostaglandin (PG) synthases were investigated in: 1) erythroblasts developed in culture from human CD34 + hematopoietic progenitors, 2) erythroblasts in bone marrow specimens, and 3) peripheral erythrocytes isolated from healthy donors and from patients with a high regeneration rate of erythrocytes. Results While COX-1 protein was observed at each stage of erythroblast development, COX-2 protein was induced at later stages through a p38/MAPK-dependent pathway. Both COX isoforms were also observed in mature erythroblasts of the bone marrow. Erythroblasts developed in culture synthesized significantly more PGE 2 than TXB 2 and indomethacin delayed erythroid maturation. COX-1 and COX-2 were also observed in erythrocytes by immunostainings, although COX expression was confined to a fraction of circulating erythrocytes. Peripheral erythrocytes synthesized low but detectable amounts of PGE 2 and TXB 2 . Similarly to erythroblast progenitors, PGE 2 was the prevalent prostanoid released by erythrocytes. This biosynthetic capacity was significantly increased in erythrocytes from patients with accelerated erythropoiesis as compared to controls. Conclusions Both COX isoforms are present and enzymatically active during human erythropoiesis, although with different kinetics, and COX-derived prostanoids may play a role in erythroid maturation. Furthermore, peripheral erythrocytes retain in part the capacity of expressing COX and synthesizing prostanoids, which may contribute to the hemostatic/thrombotic response to vascular injury in different diseases, including congenital hemolytic disorders.

Background— To investigate early events possibly related to the development of diabetic angiopathy, we examined whether 8-iso-prostaglandin F 2α (8-iso-PGF 2α ) formation, a marker of in vivo oxidant stress, is altered in different stages of type 1 diabetes (T1DM) and whether it correlates with the rate of thromboxane (TX) A 2 biosynthesis, a marker of in vivo platelet activation. We also investigated the relationship between inflammatory markers and F 2 -isoprostane formation in this setting. Methods and Results— A cross-sectional study was performed in 23 insulin-treated patients aged 1 year, group B). Urinary 8-iso-PGF 2α and 11-dehydro-TXB 2 were measured in all patients and in age- and gender-matched controls. Circulating interleukin-6 (IL-6), tumor necrosis factor-α, and C-reactive protein were also determined as markers of the inflammatory response. Fifteen of the 23 children in group A were reexamined after 12 months. Compared with either controls or group B, diabetic children in group A showed significantly higher levels of 8-iso-PGF 2α , 11-dehydro-TXB 2 , IL-6, tumor necrosis factor-α, and C-reactive protein. Statistically significant correlations between IL-6 and both 8-iso-PGF 2α ( r =0.63, P 2 ( r =0.51, P P P Conclusions— These results demonstrate that enhanced lipid peroxidation and platelet activation represent early events in T1DM that are possibly related to an acute inflammatory response. These noninvasive indexes may help in further examining T1DM pathophysiology and monitoring pharmacological interventions to interfere with disease development and progression.

Parkinson's disease (PD) is one of the most common neurodegenerative disorders whose etiology is multifactorial including both hereditary and environmental factors. Currently, pathogenic mutations in at least five genes have been implicated in familial PD generally accounting for less than 10 % of all PD cases in most populations. It has been suggested that polymorphisms in other genes such as those encoding enzymes involved in oxidative metabolism and detoxification could be involved in predisposition to PD since oxidative stress in dopaminergic neurons is thought to be of central importance in the pathogenesis of the disease. The aim of our work was to study the association of genetic polymorphisms in genes involved in oxidative metabolism and detoxification mechanism, namely GSTM1, GSTT1, GSTP1, and those involved in DNA damage repair, OGG1 and XRCC1, in an Italian cohort of sporadic PD patients. We did not detect any association between GSTT1 and GTTM1 null polymorphisms and PD, whereas the 104GSTP1 polymorphism was associated with PD in male patients but not in females. Furthermore, we detected a protective effect of wild type genotype of XRCC1 in women. © 2013 Springer Science+Business Media New York.