10 research outputs found

    The Interaction of Asymptotic Giant Branch Stars with the Interstellar Medium

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    We study the hydrodynamical behavior of the gas expelled by moving Asymptotic Giant Branch Stars interacting with the ISM. Our models follow the wind modulations prescribed by stellar evolution calculations, and we cover a range of expected relative velocities (10 to 100 km/s), ISM densities (between 0.01 and 1 cm-3), and stellar progenitor masses (1 and 3.5 Msun). We show how and when bow-shocks, and cometary-like structures form, and in which regime the shells are subject to instabilities. Finally, we analyze the results of the simulations in terms of the different kinematical stellar populations expected in the Galaxy.Comment: ApJ in press, 42 pages, 12 figures, movies of the simulations will be available in the published electronic version of the pape

    The Celiac Disease and Diabetes-Dietary Intervention and Evaluation Trial (CD-DIET) protocol: A randomised controlled study to evaluate treatment of asymptomatic coeliac disease in type 1 diabetes

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    Introduction: Coeliac disease (CD) is an autoimmune condition characterised by gluten-induced intestinal inflammation, and observed at a 5-10 fold greater prevalence in type 1 diabetes. While universal screening for CD in patients with diabetes is frequently advocated, objective data is limited as to benefits on diabetes control, bone health or quality of life related to the adoption of a gluten-free diet (GFD) in the large proportion of patients with diabetes with asymptomatic CD. The Celiac Disease and Diabetes-Dietary Intervention and Evaluation Trial (CD-DIET) study is a multicenter, randomised controlled trial to evaluate the efficacy and safety of a GFD in patients with type 1 diabetes with asymptomatic CD. Methods and analysis: Children and adults (8-45 years) with type 1 diabetes will be screened for asymptomatic CD. Eligible patients with biopsy-proven CD will be randomly assigned in a 1:1 ratio to treatment with a GFD for 1 year, or continue with a gluten-containing diet. The primary outcome will evaluate the impact of the GFD on change in glycated haemoglobin. Secondary outcomes will evaluate changes in bone mineral density, blood glucose variability and health-related quality of life between GFD-treated and the regular diet group over a 1-year period. The study was initiated in 2012 and has subsequently expanded to multiple paediatric and adult centres in Ontario, Canada. Ethics and dissemination: The findings from this study will provide high-quality evidence as to the impact of GFD treatment on glycaemic control and complications in asymptomatic children and adults with CD and type 1 diabetes. Trial registration number: NCT01566110

    Gastric Biopsies: The Gap between Evidence-Based Medicine and Daily Practice in the Management of Gastric Helicobacter pylori Infection

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    BACKGROUND: Many consider histology to be the gold standard for Helicobacter pylori detection. Because the number and distribution of H pylori organisms vary, particularly in patients taking proton pump inhibitors (PPIs), the American Gastroenterological Association recommends discontinuing PPIs two weeks before endoscopy, and taking biopsies from both the body and antrum

    Primary low-grade fibromyxoid sarcoma of the large intestine with lung metastases: A case report and review of the literature

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    A 70-year old man had multiple lung nodules detected on a computed tomography (CT) performed as part of the work-up for an isolated episode of hematuria of several hours' duration. A CT-guided lung biopsy disclosed a morphologically undifferentiated neoplasm, that could not be further subclassified despite an extensive immunohistochemical panel.Four years previously the patient had undergone a left hemicolectomy in another institution to resect a 4.7 cm polypoid ulcerated area in the splenic flexure. The slides from that resection were retrieved for review at our institution. There was a variably cellular, diffuse spindle cell neoplastic proliferation involving the submucosa, muscularis propria and subserosa of the large bowel, composed of elongated spindle cells, with small, inconspicuous nucleoli, arranged in intersecting fascicles. Occasional areas of the tumor showed myxoid stroma. Mitotic activity was low.Immunohistochemistry showed strong and diffuse cytoplasmic staining for MUC4 in both the large bowel and lung tumors. Molecular profiling identified a FUS-CREB3L1 fusion gene.The constellation of morphological, immunohistochemical and molecular features are of low-grade fibromyxoid sarcoma (LGFMS) of the large bowel, with metastatic fibromyxoid sarcoma to the lung.LGFMS is a malignant, often late-metastasizing tumor, with a misleadingly bland histological appearance, that typically arises in the deep soft tissues of the proximal extremities or trunk of young adults. Accurate classification, requiring morphology and ancillary tests, is required for appropriate clinical follow-up and treatment of patients. Keywords: Colon, Low-grade fibromyxoid sarcoma, Metastasis, Lun

    Administration of Hypoxia-Activated Prodrug Evofosfamide after Conventional Adjuvant Therapy Enhances Therapeutic Outcome and Targets Cancer-Initiating Cells in Preclinical Models of Colorectal Cancer.

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    Purpose: Cancer-initiating cells (C-IC) have been described in multiple cancer types, including colorectal cancer. C-ICs are defined by their capacity to self-renew, thereby driving tumor growth. C-ICs were initially thought to be static entities; however, recent studies have determined these cells to be dynamic and influenced by microenvironmental cues such as hypoxia. If hypoxia drives the formation of C-ICs, then therapeutic targeting of hypoxia could represent a novel means to target C-ICs. Experimental Design: Patient-derived colorectal cancer xenografts were treated with evofosfamide, a hypoxia-activated prodrug (HAP), in combination with 5-fluorouracil (5-FU) or chemoradiotherapy (5-FU and radiation; CRT). Treatment groups included both concurrent and sequential dosing regimens. Effects on the colorectal cancer-initiating cell (CC-IC) fraction were assessed by serial passage in vivo limiting dilution assays. FAZA-PET imaging was utilized as a noninvasive method to assess intratumoral hypoxia. Results: Hypoxia was sufficient to drive the formation of CC-ICs and colorectal cancer cells surviving conventional therapy were more hypoxic and C-IC-like. Using a novel approach to combination therapy, we show that sequential treatment with 5-FU or CRT followed by evofosfamide not only inhibits tumor growth of xenografts compared with 5-FU or CRT alone, but also significantly decreases the CC-IC fraction. Furthermore, noninvasive FAZA-PET hypoxia imaging was predictive of a tumor's response to evofosfamide. Conclusions: Our data demonstrate a novel means to target the CC-IC fraction by adding a HAP sequentially after conventional adjuvant therapy, as well as the use of FAZA-PET as a biomarker for hypoxia to identify tumors that will benefit most from this approach. (C) 2018 AACR

    A multi-centre pathologist survey on pathological processing and regression grading of colorectal cancer resection specimens treated by neoadjuvant chemoradiation

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    To ascertain the approach and degree of consensus of pathologists in the handling and regression grading of colorectal cancer resection specimens treated with neoadjuvant chemoradiation, a ten-part questionnaire was circulated to 18 gastrointestinal pathologists in eight countries. The questions were specific and addressed pertinent issues related to colorectal cancer with neoadjuvant chemoradiation. There is a lack of consensus on how to handle the specimen, number of sections taken, correlation with pre- and post-operative radiological imaging, and especially, regression grading schema employed. Consensus in the form of guidelines is required so that the pathological assessment of these specimens will provide clinically relevant information for patient management, irrespective of location
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