Coordinated nuclease activities counteract Ku at single-ended DNA double-strand breaks.

Repair of single-ended DNA double-strand breaks (seDSBs) by homologous recombination (HR) requires the generation of a 3' single-strand DNA overhang by exonuclease activities in a process called DNA resection. However, it is anticipated that the highly abundant DNA end-binding protein Ku sequesters seDSBs and shields them from exonuclease activities. Despite pioneering works in yeast, it is unclear how mammalian cells counteract Ku at seDSBs to allow HR to proceed. Here we show that in human cells, ATM-dependent phosphorylation of CtIP and the epistatic and coordinated actions of MRE11 and CtIP nuclease activities are required to limit the stable loading of Ku on seDSBs. We also provide evidence for a hitherto unsuspected additional mechanism that contributes to prevent Ku accumulation at seDSBs, acting downstream of MRE11 endonuclease activity and in parallel with MRE11 exonuclease activity. Finally, we show that Ku persistence at seDSBs compromises Rad51 focus assembly but not DNA resection.EMBO (long-term fellowship (ALTF 93-2010)), Cancer Research UK (Grant IDs: C6/A11224, C6/A18796, C6946/A14492), La Ligue Nationale Contre le Cancer (senior post-doctoral fellowship, Equipe Labellisée 2013), Wellcome Trust (WT092096), University of Cambridge, INSERMThis is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/ncomms1288

Development and evaluation of the Walking Estimated-Limitation Calculated by History questionnaire in patients with claudication

BACKGROUND: The Walking Impairment Questionnaire (WIQ) is used to estimate walking impairment in patients with peripheral artery disease; however, it faces frequent errors when self-completed and is complex to score. We aimed to validate an alternative, easily scored four-item tool, the Walking Estimated-Limitation Calculated by History (WELCH) questionnaire. METHODS: The WIQ and WELCH were prospectively tested in five centers. We studied 434 patients, among which 298 had a treadmill test (3.2 km/h; 10% slope) to determine their maximum walking time (MWT), and 30 were seen twice during the study period. RESULTS: After self-completion, we found at least one error in 177 WIQ (40.8%; 95% confidence interval [CI], 36.3%-45.5%) vs 56 WELCH (12.9%; 95% CI, 10.1%-16.4%) questionnaires (P < .0001). When scoring only questionnaires without missing or duplicate answers, 267 WIQ (61.5%; 95% CI, 56.9%-66.0%) vs 393 WELCH (90.6%; 95% CI, 87.4%-93.0%) questionnaires could be scored (P < .001). The median MWT was 233 seconds (interquartile range, 133-654 seconds) for the 298 patients who had a treadmill test. When the 296 patients who had both questionnaire scores available were studied, no difference was found between the Pearson r coefficient of correlation of the WIQ (r = 0.615) and the WELCH (r = 0.653) with MWT (P = .211). In the 30 patients who completed the WELCH twice, correlation was r = 0.839 (P < .001) between the two scores in 22 nonrevascularized patients, and the area under the receiver-operating characteristic curve was 0.830 +/- 0.105 (P < .01) to discriminate the eight revascularized from the 22 nonrevascularized patients. CONCLUSIONS: The WELCH questionnaire is a simple tool to estimate walking limitation in patients with suspected peripheral artery disease. It is easily scored by mental calculation. It may help to standardize the estimation of walking limitation in routine clinical practice

Quiescence: early evolutionary origins and universality do not imply uniformity

Cell cycle investigations have focused on relentless exponential proliferation of cells, an unsustainable situation in nature. Proliferation of cells, whether microbial or metazoan, is interrupted by periods of quiescence. The vast majority of cells in an adult metazoan lie quiescent. As disruptions in this quiescence are at the foundation of cancer, it will be important for the field to turn its attention to the mechanisms regulating quiescence. While often presented as a single topic, there are multiple forms of quiescence each with complex inputs, some of which are tied to conceptually challenging aspects of metazoan regulation such as size control. In an effort to expose the enormity of the challenge, I describe the differing biological purposes of quiescence, and the coupling of quiescence in metazoans to growth and to the structuring of tissues during development. I emphasize studies in the organism rather than in tissue culture, because these expose the diversity of regulation. While quiescence is likely to be a primitive biological process, it appears that in adapting quiescence to its many distinct biological settings, evolution has diversified it. Consideration of quiescence in different models gives us an overview of this diversity

Using street view imagery for 3-D survey of rock slope failures

We discuss here different challenges and limitations of surveying rock slope failures using 3-D reconstruction from image sets acquired from street view imagery (SVI). We show how rock slope surveying can be performed using two or more image sets using online imagery with photographs from the same site but acquired at different instances. Three sites in the French alps were selected as pilot study areas: (1) a cliff beside a road where a protective wall collapsed, consisting of two image sets (60 and 50 images in each set) captured within a 6-year time frame; (2) a large-scale active landslide located on a slope at 250m from the road, using seven image sets (50 to 80 images per set) from five different time periods with three image sets for one period; (3) a cliff over a tunnel which has collapsed, using two image sets captured in a 4-year time frame. The analysis include the use of different structure from motion (SfM) programs and a comparison between the extracted photogrammetric point clouds and a lidar-derived mesh that was used as a ground truth. Results show that both landslide deformation and estimation of fallen volumes were clearly identified in the different point clouds. Results are site- and software-dependent, as a function of the image set and number of images, with model accuracies ranging between 0.2 and 3.8m in the best and worst scenario, respectively. Although some limitations derived from the generation of 3-D models from SVI were observed, this approach allowed us to obtain preliminary 3-D models of an area without on-field images, allowing extraction of the pre-failure topography that would not be available otherwise

Multiple Integrated Non-clinical Studies Predict the Safety of Lentivirus-Mediated Gene Therapy for \u3b2-Thalassemia

Gene therapy clinical trials require rigorous non-clinical studies in the most relevant models to assess the benefit-to-risk ratio. To support the clinical development of gene therapy for \u3b2-thalassemia, we performed in vitro and in vivo studies for prediction of safety. First we developed newly GLOBE-derived vectors that were tested for their transcriptional activity and potential interference with the expression of surrounding genes. Because these vectors did not show significant advantages, GLOBE lentiviral vector (LV) was elected for further safety characterization. To support the use of hematopoietic stem cells (HSCs) transduced by GLOBE LV for the treatment of \u3b2-thalassemia, we conducted toxicology, tumorigenicity, and biodistribution studies in compliance with the OECD Principles of Good Laboratory Practice. We demonstrated a lack of toxicity and tumorigenic potential associated with GLOBE LV-transduced cells. Vector integration site (IS) studies demonstrated that both murine and human transduced HSCs retain self-renewal capacity and generate new blood cell progeny in the absence of clonal dominance. Moreover, IS analysis showed an absence of enrichment in cancer-related genes, and the genes targeted by GLOBE LV in human HSCs are well known sites of integration, as seen in other lentiviral gene therapy trials, and have not been associated with clonal expansion. Taken together, these integrated studies provide safety data supporting the clinical application of GLOBE-mediated gene therapy for \u3b2-thalassemia

Eddy-Permitting Ocean Circulation Hindcasts of Past Decades

International audienc

Reinforced Concretes of Tomorrow: Corrosion Behaviour according to Exposure Classes

Reinforced concrete is the most widely used building material but its durability in terms of concrete cover performance and corrosion of steel rebar is still a key point to be studied. To address this topic, within the frame of the national project PERFDUB, two series of eleven reinforced concrete specimens (with metric dimensions) were cast with innovative concrete mixes representative of the French experience, two shapes of rebar and two concrete covers. Then, these specimens were exposed in two natural exposure sites, one in Epernon for carbonation (XC4) and a second one in La Rochelle in the Atlantic Ocean in a tidal zone for chloride ions (XS3m). Their corrosion was carried out using non-destructive testing. In addition, in order to follow the corrosion evolution more accurately in a continuous way, two series of three specimens were casted with embedded sensors and were exposed in two other outdoor sites in Marne-la-Vallée (XC4) and in Eqiom facility (XS3e). The first results of this 20-year project in terms of corrosion of these reinforced concrete specimens obtained with laboratory and field equipment and with monitoring are presented in this paper

Should we consider Dupuytren's contracture as work-related? A review and meta-analysis of an old debate

International audienceABSTRACT: BACKGROUND: In view of the conflicting opinions published, a meta-analysis was undertaken on epidemiological studies in order to assess any association between Dupuytren's contracture and work exposure. METHODS: Using the key words: "occupational disease", "work" and "Dupuytren contracture" without limitation on language or year of publication, epidemiological studies were selected from four databases (Pub-Med, Embase, Web of science, BDSP) after two rounds (valid control group, valid work exposure). A quality assessment list was constructed and used to isolate papers with high quality methodological criteria (scores of 13 or above, HQMC). Relevant associations between manual work, vibration exposure (at work) and Dupuytren's contracture were extracted from the articles and a metarisk calculated using the generic variance approach (meta-odds ratios, meta-OR). RESULTS: From 1951 to 2007, 14 epidemiological studies (including 2 cohort studies, 3 case-control studies, and 9 cross-sectional studies/ population surveys) were included. Two different results could be extracted from five studies (based on different types of exposure), leading to 19 results, 12 for manual work (9 studies), and 7 for vibration exposure (5 studies). Six studies met the HQMC, yielding 9 results, 5 for manual work and 4 for vibration exposure. Five studies found a dose-response relationship. The meta-OR for manual work was 2.02[1.57;2.60] (HQMC studies only: 2.01[1.51;2.66]), and the meta-OR for vibration exposure was 2.88 [1.36;6.07] (HQMC studies only: 2.14[1.59;2.88]). CONCLUSION: These results support the hypothesis of an association between high levels of work exposure (manual work and vibration exposure) and Dupuytren's contracture in certain cases