3,223 research outputs found

    Regression of murine lung tumors by the let-7 microRNA.

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    MicroRNAs (miRNAs) have recently emerged as an important new class of cellular regulators that control various cellular processes and are implicated in human diseases, including cancer. Here, we show that loss of let-7 function enhances lung tumor formation in vivo, strongly supporting the hypothesis that let-7 is a tumor suppressor. Moreover, we report that exogenous delivery of let-7 to established tumors in mouse models of non-small-cell lung cancer (NSCLC) significantly reduces the tumor burden. These results demonstrate the therapeutic potential of let-7 in NSCLC and point to miRNA replacement therapy as a promising approach in cancer treatment

    Extramural venous invasion is a potential imaging predictive biomarker of neoadjuvant treatment in rectal cancer

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    BACKGROUND: Extramural venous invasion (EMVI) is a poor prognostic factor in rectal cancer and identified on magnetic resonance imaging (MRI) (mrEMVI). The clinical relevance of improvement in mrEMVI following neoadjuvant therapy is unknown. This study aimed to demonstrate that regression of mrEMVI following neoadjuvant chemoradiotherapy (CRT) results in improved outcomes and mrEMVI can be used as an imaging biomarker METHODS: Retrospective analysis of prospectively collected data was conducted examining the staging and post-treatment MRIs of patients who had presented with EMVI-positive rectal cancer. All patients had undergone neoadjuvant CRT and curative surgery. Changes in mrEMVI were graded with a new MRI-based TRG scaleā€“mr-vTRG; and related to disease-free survival (DFS). The study fulfilled Reporting Recommendations for Tumour Marker Prognostic Studies criteria for biomarkers. RESULTS: Sixty-two patients were included. Thirty-five patients showed more than 50% fibrosis of mrEMVI (mr-vTRG 1-3); 3-year DFS 87.8% and 9% recurrence. Twenty-seven patients showed less than 50% fibrosis (mr-vTRG 4-5); 3-year DFS 45.8% with 44% recurrence ā€“ P<0.0001. On multivariate Cox-regression, only mr-vTRG 4-5 increased risk of disease recurrence ā€“ HR=5.748. CONCLUSION: Patients in whom there has been a significant response of EMVI to CRT show improved DFS. Those patients with poor response should be considered for intensive treatment. As an imaging biomarker in rectal cancer, mrEMVI can be used

    Defining response to radiotherapy in rectal cancer using magnetic resonance imaging and histopathological scales

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    Aim: To define good and poor regression using pathology and MRI regression scales after neo-adjuvant chemotherapy for rectal cancer. Methods: A systematic review of all studies up to December 2015, without language restriction that were identified from MEDLINE, Cochrane Controlled Trials Register (1960ā€“2015), and EMBASE (1991ā€“2015). Searches were performed of article bibliographies and conference abstracts. MeSH and text words, included ā€œtumour regressionā€, ā€œmrTRGā€, ā€œpoor responseā€ and ā€œcolorectal cancersā€. Clinical studies using either MRI or histopathological TRG scales to define good and poor responders were included in relation to outcomes (local (LR), distant recurrence (DR), disease free (DFS), overall survival (OS)). There was no age restriction to included patients nor stage of cancer.Data was extracted by two authors independently using pre-defined outcome measures. Results: Quantitative data (prevalence) were extracted and analysed according to meta-analytical techniques using comprehensive meta-analysis. Qualitative data (LR, DR, DFS &OS) were presented as ranges. The overall proportion of poor responders after neo-adjuvant CRT was 37.7% (CI: 30.1 to 45.8). There were 19 different reported histopathological scales and one MRI regression scale (mrTRG). Clinical studies used nine and six histopathological scales for poor and good responders respectively. All studies using MRI to define good and poor response used one scale. The most common histopathological definition for good response was the Mandard grades 1&2 or Dworak grades 3&4; Mandard 3,4&5 and Dworak 0,1&2 were used for poor response. For histopathological grades, the 5-year outcomes for poor responders were LR 3.4-4.3%, DR 14.3-20.3%, DFS 61.7-68.1% and OS 60.7-69.1. Good pathological response 5-year outcomes were LR, 0-1.8%; DR, 0-11.6%; DFS, 78.4-86.7%; and, OS, 77.4-88.2%. A poor response on MRI (mrTRG 4,5) resulted in 5-year LR 4-29%, DR 9%, DFS 31-59% and OS 27-68%. The 5-year outcomes with a good response on MRI (mrTRG 1,2 & 3) was LR 1-14%, DR 3%, DFS 64-83% and OS 72-90%. Conclusions: For histopathology regression assessment Mandard1,2/Dworak3,4 should be used for good and Mandard3,4,5/Dworak0,1,2 for poor response. MRI indicates good and poor response by mrTRG1-3 and mrTRG4-5 respectively

    Establishing the values for patient engagement (PE) in health-related quality of life (HRQoL) research: an international, multiple-stakeholder perspective

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    PurposeActive patient engagement is increasingly viewed as essential to ensuring that patient-driven perspectives are considered throughout the research process. However, guidance for patient engagement (PE) in HRQoL research does not exist, the evidence-base for practice is limited, and we know relatively little about underpinning values that can impact on PE practice. This is the first study to explore the values that should underpin PE in contemporary HRQoL research to help inform future good practice guidance. MethodsA modified ā€˜World CafĆ©ā€™ was hosted as a collaborative activity between patient partners, clinicians and researchers: self-nominated conference delegates participated in group discussions to explore values associated with the conduct and consequences of PE. Values were captured via post-it notes and by nominated note-takers. Data were thematically analysed: emergent themes were coded and agreement checked. Association between emergent themes, values and the Public Involvement Impact Assessment Framework were explored. ResultsEighty participants, including 12 patient partners, participated in the 90-min event. Three core values were defined: (1) building relationships; (2) improving research quality and impact; and (3) developing best practice. Participants valued the importance of building genuine, collaborative and deliberative relationshipsā€”underpinned by honesty, respect, co-learning and equityā€”and the impact of effective PE on research quality and relevance. Conclusions An explicit statement of values seeks to align all stakeholders on the purpose, practice and credibility of PE activities. An innovative, flexible and transparent research environment was valued as essential to developing a trustworthy evidence-base with which to underpin future guidance for good PE practice.Peer reviewe

    Extended lymphadenectomy for locally advanced and recurrent rectal cancer

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    Purpose The purpose of this study is to assess the value of extended (lateral) lymphadenectomy (EL) in the operative management of locally advanced and recurrent rectal cancer. Methods Patients that underwent exenterative surgery for locally advanced or recurrent rectal cancer between 2006 and 2009 were included in the study. A decision for EL was taken at the local multidisciplinary meeting based on the radiological findings. Perioperative and oncological outcomes were assessed and compared between the EL and non-EL group prospectively. Results Forty-one consecutive patients were included in the study (EL = 17). The median age was 57 (40ā€“71) for EL and 66 (39ā€“81) years for non-EL. Of patients, 27 (EL = 13) and 14 (EL = 4) underwent pelvic exenteration and abdominosacral resection, respectively. Twelve (EL = 7) patients were diagnosed with locally advanced primary rectal cancer. Thirty-one (EL = 12) patients received neoadjuvant radiotherapy. The median intraoperative time, blood loss and hospital stay were 9 h (3ā€“13), 1.5 l (0.3ā€“7) and 14 days (12ā€“72), respectively, for the EL group, and 8 h (4ā€“15), 1.6 l (0.25ā€“17) and 14 days (10ā€“86), respectively, for the non-EL (p ā‰„ 0.394). Morbidity was similar between the two groups (EL = 4, non-EL = 9; p = 0.344). Complete tumour resection (R0) was achieved in 30 (73.17%) patients, 12 (70.58%) in the EL group and 18 (75%) in the non-EL group (p = 0.649). There was no significant difference in 5-year survival (EL = 60.7%, non-EL = 75.2%; p = 0.447), local recurrence (EL = 53.6%, non-EL = 65.4%; p = 0.489) and disease-free survival (EL = 53.6%, non-EL = 51.4%; p = 0.814). Conclusions The present study demonstrated that EL does not provide a statistically significant advantage in survival or recurrence rates, for patients with locally advanced primary or recurrent rectal cancer

    Poor survival outcomes in HER2 positive breast cancer patients with low grade, node negative tumours

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    We present a retrospective analysis on a cohort of low-grade, node-negative patients showing that human epidermal growth factor receptor 2 (HER2) status significantly affects the survival in this otherwise very good prognostic group. Our results provide support for the use of adjuvant trastuzumab in patients who are typically classified as having very good prognosis, not routinely offered standard chemotherapy, and who as such do not fit current UK prescribing guidelines for trastuzumab

    Counting supersymmetric branes

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    Maximal supergravity solutions are revisited and classified, with particular emphasis on objects of co-dimension at most two. This class of solutions includes branes whose tension scales with g_s^{-\sigma} for \sigma>2. We present a group theory derivation of the counting of these objects based on the corresponding tensor hierarchies derived from E11 and discrete T- and U-duality transformations. This provides a rationale for the wrapping rules that were recently discussed for \sigma<4 in the literature and extends them. Explicit supergravity solutions that give rise to co-dimension two branes are constructed and analysed.Comment: 1+33 pages. To the memory of Laurent Houart. v2: Published version with added reference

    Type I interferon signaling deficiency results in dysregulated innate immune responses to SARS-CoV-2 in mice

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    SARS-CoV-2 is a newly emerged coronavirus, causing the global pandemic of respiratory coronavirus disease (COVID-19). The type I interferon (IFN) pathway is of particular importance for anti-viral defence and recent studies identified that type I IFNs drive early inflammatory responses to SARS-CoV-2. Here, we use a mouse model of SARS-CoV-2 infection, facilitating viral entry by intranasal recombinant Adeno-Associated Virus (rAAV) transduction of hACE2 in wildtype (WT) and type I IFN-signalling-deficient (Ifnar1-/- ) mice, to study type I IFN signalling deficiency and innate immune responses during SARS-CoV-2 infection. Our data show that type I IFN signaling is essential for inducing anti-viral effector responses to SARS-CoV-2, control of virus replication and to prevent enhanced disease. Furthermore, hACE2-Ifnar1-/- mice had increased gene expression of the chemokine Cxcl1 and airway infiltration of neutrophils as well as a reduced and delayed production of monocyte-recruiting chemokine CCL2. hACE2-Ifnar1-/- mice showed altered recruitment of inflammatory myeloid cells to the lung upon SARS-CoV-2 infection, with a shift from Ly6C+ to Ly6C- expressing cells. Together, our findings suggest that type I IFN deficiency results in a dysregulated innate immune response to SARS-CoV-2 infection. This article is protected by copyright. All rights reserved

    A comparison of standard and high dose adenosine protocols in routine vasodilator stress cardiovascular magnetic resonance: dosage affects hyperaemic myocardial blood flow in patients with severe left ventricular systolic impairment

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    Background: Adenosine stress perfusion cardiovascular magnetic resonance (CMR) is commonly used in the assessment of patients with suspected ischaemia. Accepted protocols recommend administration of adenosine at a dose of 140Ā Āµg/kg/min increased up to 210Ā Āµg/kg/min if required. Conventionally, adequate stress has been assessed using change in heart rate, however, recent studies have suggested that these peripheral measurements may not reflect hyperaemia and can be blunted, in particular, in patients with heart failure. This study looked to compare stress myocardial blood flow (MBF) and haemodynamic response with different dosing regimens of adenosine during stress perfusion CMR in patients and healthy controls. Methods: 20 healthy adultĀ subjects were recruited as controls to compare 3 adenosine perfusion protocols: standard dose (140Ā Āµg/kg/min for 4Ā min), high dose (210Ā Āµg/kg/min for 4Ā min) and long dose (140Ā Āµg/kg/min for 8Ā min). 60 patients with either known or suspected coronary artery disease (CAD) or with heart failure and different degrees of left ventricular (LV) dysfunction underwent adenosine stress with standard and high dose adenosine within the same scan. All studies were carried out on a 3Ā T CMR scanner. Quantitative global myocardial perfusion and haemodynamic response were compared between doses. Results: In healthy controls, no significant difference was seen in stress MBF between the 3 protocols. In patients with known or suspected CAD, and those with heart failure and mild systolic impairment (LV ejection fraction (LVEF) ā‰„ 40%) no significant difference was seen in stress MBF between standard and high dose adenosine. In those with LVEF < 40%, there was a significantly higher stress MBF following high dose adenosine compared to standard dose (1.33 Ā± 0.46 vs 1.10 Ā± 0.47Ā ml/g/min, p = 0.004). Non-responders to standard dose adenosine (defined by an increase in heart rate (HR) < 10Ā bpm) had a significantly higher stress HR following high dose (75 Ā± 12 vs 70 Ā± 14Ā bpm, p = 0.034), but showed no significant difference in stress MBF. Conclusions: Increasing adenosine dose from 140 to 210Ā Āµg/kg/min leads to increased stress MBF in patients with significantly impaired LV systolic function. Adenosine dose in clinical perfusion assessment may need to be increased in these patients

    Medical causes of admissions to hospital among adults in Africa: a systematic review.

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    BACKGROUND: Despite the publication of several studies on the subject, there is significant uncertainty regarding the burden of disease among adults in sub-Saharan Africa (sSA). OBJECTIVES: To describe the breadth of available data regarding causes of admission to hospital, to systematically analyze the methodological quality of these studies, and to provide recommendations for future research. DESIGN: We performed a systematic online and hand-based search for articles describing patterns of medical illnesses in patients admitted to hospitals in sSA between 1950 and 2010. Diseases were grouped into bodily systems using International Classification of Disease (ICD) guidelines. We compared the proportions of admissions and deaths by diagnostic category using Ļ‡2. RESULTS: Thirty articles, describing 86,307 admissions and 9,695 deaths, met the inclusion criteria. The leading causes of admission were infectious and parasitic diseases (19.8%, 95% confidence interval [CI] 19.6-20.1), respiratory (16.2%, 95% CI 16.0-16.5) and circulatory (11.3%, 95% CI 11.1-11.5) illnesses. The leading causes of death were infectious and parasitic (17.1%, 95% CI 16.4-17.9), circulatory (16%, 95% CI 15.3-16.8) and digestive (16.2%, 95% CI 15.4-16.9). Circulatory diseases increased from 3.9% of all admissions in 1950-59 to 19.9% in 2000-2010 (RR 5.1, 95% CI 4.5-5.8, test for trend p<0.00005). The most prevalent methodological deficiencies, present in two-thirds of studies, were failures to use standardized case definitions and ICD guidelines for classifying illnesses. CONCLUSIONS: Cardiovascular and infectious diseases are currently the leading causes of admissions and in-hospital deaths in sSA. Methodological deficiencies have limited the usefulness of previous studies in defining national patterns of disease in adults. As African countries pass through demographic and health transition, they need to significantly invest in clinical research capacity to provide an accurate description of the disease burden among adults for public health policy
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