55 research outputs found

    Parity-Violating Electron Scattering from 4He and the Strange Electric Form Factor of the Nucleon

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    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from ^4He at an average scattering angle = 5.7 degrees and a four-momentum transfer Q^2 = 0.091 GeV^2. From these data, for the first time, the strange electric form factor of the nucleon G^s_E can be isolated. The measured asymmetry of A_PV = (6.72 +/- 0.84 (stat) +/- 0.21 (syst) parts per million yields a value of G^s_E = -0.038 +/- 0.042 (stat) +/- 0.010 (syst), consistent with zero

    Texture analysis-and support vector machine-assisted diffusional kurtosis imaging may allow in vivo gliomas grading and IDH-mutation status prediction:a preliminary study

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    We sought to investigate, whether texture analysis of diffusional kurtosis imaging (DKI) enhanced by support vector machine (SVM) analysis may provide biomarkers for gliomas staging and detection of the IDH mutation. First-order statistics and texture feature extraction were performed in 37 patients on both conventional (FLAIR) and mean diffusional kurtosis (MDK) images and recursive feature elimination (RFE) methodology based on SVM was employed to select the most discriminative diagnostic biomarkers. The first-order statistics demonstrated significantly lower MDK values in the IDH-mutant tumors. This resulted in 81.1% accuracy (sensitivity = 0.96, specificity = 0.45, AUC 0.59) for IDH mutation diagnosis. There were non-significant differences in average MDK and skewness among the different tumour grades. When texture analysis and SVM were utilized, the grading accuracy achieved by DKI biomarkers was 78.1% (sensitivity 0.77, specificity 0.79, AUC 0.79); the prediction accuracy for IDH mutation reached 83.8% (sensitivity 0.96, specificity 0.55, AUC 0.87). For the IDH mutation task, DKI outperformed significantly the FLAIR imaging. When using selected biomarkers after RFE, the prediction accuracy achieved 83.8% (sensitivity 0.92, specificity 0.64, AUC 0.88). These findings demonstrate the superiority of DKI enhanced by texture analysis and SVM, compared to conventional imaging, for gliomas staging and prediction of IDH mutational status

    Conditional Inactivation of Brca1, p53 and Rb in Mouse Ovaries Results in the Development of Leiomyosarcomas

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    Epithelial ovarian cancer (EOC) is thought to arise in part from the ovarian surface epithelium (OSE); however, the molecular events underlying this transformation are poorly understood. Germline mutations in the BRCA1 tumor suppressor gene result in a significantly increased risk of developing EOC and a large proportion of sporadic EOCs display some sort of BRCA1 dysfunction. To generate a model in which Brca1-mediated transformation can be studied, we previously inactivated Brca1 alone in murine OSE, which resulted in an increased accumulation of premalignant changes, but no tumor formation. In this study, we examined tumor formation in mice with conditionally expressed alleles of Brca1, p53 and Rb, alone or in combination. Intrabursal injection of adenovirus expressing Cre recombinase to inactivate p53 resulted in tumors in 100% of mice. Tumor progression was accelerated in mice with concomitant inactivation of Brca1 and p53, but not Rb and p53. Immunohistologic analyses classified the tumors as leiomyosarcomas that may be arising from the ovarian bursa. Brca1 inactivation in primary cultures of murine OSE cells led to a suppression of proliferation that could be rescued by concomitant inactivation of p53 and/or Rb. Brca1-deficient OSE cells displayed an increased sensitivity to the DNA damaging agent cisplatin, and this effect could be modulated by inactivation of p53 and/or Rb. These results indicate that Brca1 deficiency can accelerate tumor development and alter the sensitivity of OSE cells to chemotherapeutic agents. Intrabursal delivery of adenovirus intended to alter gene expression in the ovarian surface epithelium may, in some strains of mice, result in more rapid transformation of adjacent cells, resulting in leiomyosarcomas

    Longitudinal Molecular Trajectories of Diffuse Glioma in Adults

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    The evolutionary processes that drive universal therapeutic resistance in adult patients with diffuse glioma remain unclear ¹² . Here we analysed temporally separated DNA-sequencing data and matched clinical annotation from 222 adult patients with glioma. By analysing mutations and copy numbers across the three major subtypes of difuse glioma, we found that driver genes detected at the initial stage of disease were retained at recurrence, whereas there was little evidence of recurrence-specifc gene alterations. Treatment with alkylating agents resulted in a hypermutator phenotype at diferent rates across the glioma subtypes, and hypermutation was not associated with diferences in overall survival. Acquired aneuploidy was frequently detected in recurrent gliomas and was characterized by IDH mutation but without co-deletion of chromosome arms 1p/19q, and further converged with acquired alterations in the cell cycle and poor outcomes. The clonal architecture of each tumour remained similar over time, but the presence of subclonal selection was associated with decreased survival. Finally, there were no differences in the levels of immunoediting between initial and recurrent gliomas. Collectively, our results suggest that the strongest selective pressures occur during early glioma development and that current therapies shape this evolution in a largely stochastic manner

    Glioma imaging in Europe: A survey of 220 centres and recommendations for best clinical practice

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    Objectives: At a European Society of Neuroradiology (ESNR) Annual Meeting 2015 workshop, commonalities in practice, current controversies and technical hurdles in glioma MRI were discussed. We aimed to formulate guidance on MRI of glioma and determine its feasibility, by seeking information on glioma imaging practices from the European Neuroradiology community. Methods: Invitations to a structured survey were emailed to ESNR members (n=1,662) and associates (n=6,400), European national radiologists’ societies and distributed via social media. Results: Responses were received from 220 institutions (59% academic). Conventional imaging protocols generally include T2w, T2-FLAIR, DWI, and pre- and post-contrast T1w. Perfusion MRI is used widely (85.5%), while spectroscopy seems reserved for specific indications. Reasons for omitting advanced imaging modalities include lack of facility/software, time constraints and no requests. Early postoperative MRI is routinely carried out by 74% within 24–72 h, but only 17% report a percent measure of resection. For follow-up, most sites (60%) issue qualitative reports, while 27% report an assessment according to the RANO criteria. A minori

    Safety of bronchial thermoplasty in patients with severe refractory asthma.

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    BACKGROUND: Patients with severe refractory asthma treated with bronchial thermoplasty (BT), a bronchoscopic procedure that improves asthma control by reducing excess airway smooth muscle, were followed up for 5 years to evaluate long-term safety of this procedure. OBJECTIVES: To assess long-term safety of BT for 5 years. METHODS: Patients with asthma aged 18 to 65 years requiring high-dose inhaled corticosteroids (ICSs) (>750 μg/d of fluticasone propionate or equivalent) and long-acting β2-agonists (LABAs) (at least 100 μg/d of salmeterol or equivalent), with or without oral prednisone (≤30 mg/d), leukotriene modifiers, theophylline, or other asthma controller medications were enrolled in the Research in Severe Asthma (RISA) Trial. Patients had a prebronchodilator forced expiratory volume in 1 second of 50% or more of predicted, demonstrated methacholine airway hyperresponsiveness, had uncontrolled symptoms despite taking maintenance medication, abstained from smoking for 1 year or greater, and had a smoking history of less than 10 pack-years. RESULTS: Fourteen patients (of the 15 who received active treatment in the RISA Trial) participated in the long-term follow-up study for 5 years. The rate of respiratory adverse events (AEs per patient per year) was 1.4, 2.4, 1.7, and 2.4, respectively, in years 2 to 5 after BT. There was a decrease in hospitalizations and emergency department visits for respiratory symptoms in each of years 1, 2, 3, 4, and 5 compared with the year before BT treatment. Measures of lung function showed no deterioration for 5 years. CONCLUSION: Our findings suggest that BT is safe for 5 years after BT in patients with severe refractory asthma. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00401986

    Safety of bronchial thermoplasty in patients with severe refractory asthma

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    Background: Patients with severe refractory asthma treated with bronchial thermoplasty (BT), a bronchoscopic procedure that improves asthma control by reducing excess airway smooth muscle, were followed up for 5 years to evaluate long-term safety of this procedure. Objectives: To assess long-term safety of BT for 5 years. Methods: Patients with asthma aged 18 to 65 years requiring high-dose inhaled corticosteroids (ICSs) (>750 μg/d of fluticasone propionate or equivalent) and long-acting β2-agonists (LABAs) (at least 100 μg/d of salmeterol or equivalent), with or without oral prednisone (≤30 mg/d), leukotriene modifiers, theophylline, or other asthma controller medications were enrolled in the Research in Severe Asthma (RISA) Trial. Patients had a prebronchodilator forced expiratory volume in 1 second of 50% or more of predicted, demonstrated methacholine airway hyperresponsiveness, had uncontrolled symptoms despite taking maintenance medication, abstained from smoking for 1 year or greater, and had a smoking history of less than 10 pack-years. Results: Fourteen patients (of the 15 who received active treatment in the RISA Trial) participated in the long-term follow-up study for 5 years. The rate of respiratory adverse events (AEs per patient per year) was 1.4, 2.4, 1.7, and 2.4, respectively, in years 2 to 5 after BT. There was a decrease in hospitalizations and emergency department visits for respiratory symptoms in each of years 1, 2, 3, 4, and 5 compared with the year before BT treatment. Measures of lung function showed no deterioration for 5 years. Conclusion: Our findings suggest that BT is safe for 5 years after BT in patients with severe refractory asthma. Trial Registration: clinicaltrials.gov Identifier: NCT00401986. © 2013 American College of Allergy, Asthma and Immunology. Published by Elsevier Inc. All rights reserved
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