571 research outputs found

    Lung Cancer in Pulmonary Fibrosis: Tales of Epithelial Cell Plasticity

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    Lung epithelial cells exhibit a high degree of plasticity. Alterations to lung epithelial cell function are critically involved in several chronic lung diseases such as pulmonary fibrosis. Pulmonary fibrosis is characterized by repetitive injury and subsequent impaired repair of epithelial cells, which leads to aberrant growth factor activation and fibroblast accumulation. Increased proliferation and hyper- and metaplasia of epithelial cells upon injury have also been observed in pulmonary fibrosis; this epithelial cell activation might represent the basis for lung cancer development. Indeed, several studies have provided histopathological evidence of an increased incidence of lung cancer in pulmonary fibrosis. The mechanisms involved in the development of cancer in pulmonary fibrosis, however, remain poorly understood. This review highlights recently uncovered molecular mechanisms shared between lung cancer and fibrosis, which extend the current evidence of a common trait of cancer and fibrosis, as provided by histopathological observations. Copyright (C) 2011 S. Karger AG, Base

    Protocol: developing a conceptual framework of patient mediated knowledge translation, systematic review using a realist approach

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    <p>Abstract</p> <p>Background</p> <p>Patient involvement in healthcare represents the means by which to achieve a healthcare system that is responsive to patient needs and values. Characterization and evaluation of strategies for involving patients in their healthcare may benefit from a knowledge translation (KT) approach. The purpose of this knowledge synthesis is to develop a conceptual framework for patient-mediated KT interventions.</p> <p>Methods</p> <p>A preliminary conceptual framework for patient-mediated KT interventions was compiled to describe intended purpose, recipients, delivery context, intervention, and outcomes. A realist review will be conducted in consultation with stakeholders from the arthritis and cancer fields to explore how these interventions work, for whom, and in what contexts. To identify patient-mediated KT interventions in these fields, we will search MEDLINE, the Cochrane Library, and EMBASE from 1995 to 2010; scan references of all eligible studies; and examine five years of tables of contents for journals likely to publish quantitative or qualitative studies that focus on developing, implementing, or evaluating patient-mediated KT interventions. Screening and data collection will be performed independently by two individuals.</p> <p>Conclusions</p> <p>The conceptual framework of patient-mediated KT options and outcomes could be used by healthcare providers, managers, educationalists, patient advocates, and policy makers to guide program planning, service delivery, and quality improvement and by us and other researchers to evaluate existing interventions or develop new interventions. By raising awareness of options for involving patients in improving their own care, outcomes based on using a KT approach may lead to greater patient-centred care delivery and improved healthcare outcomes.</p

    Artificial graphene as a tunable Dirac material

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    Artificial honeycomb lattices offer a tunable platform to study massless Dirac quasiparticles and their topological and correlated phases. Here we review recent progress in the design and fabrication of such synthetic structures focusing on nanopatterning of two-dimensional electron gases in semiconductors, molecule-by-molecule assembly by scanning probe methods, and optical trapping of ultracold atoms in crystals of light. We also discuss photonic crystals with Dirac cone dispersion and topologically protected edge states. We emphasize how the interplay between single-particle band structure engineering and cooperative effects leads to spectacular manifestations in tunneling and optical spectroscopies.Comment: Review article, 14 pages, 5 figures, 112 Reference

    Detection of a MicroRNA Signal in an In Vivo Expression Set of mRNAs

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    Background. microRNAs (miRNAs) are approximately 21 nucleotide non-coding transcripts capable of regulating gene expression. The most widely studied mechanism of regulation involves binding of a miRNA to the target mRNA. As a result, translation of the target mRNA is inhibited and the mRNA may be destabilized. The inhibitory effects of miRNAs have been linked to diverse cellular processes including malignant proliferation, apoptosis, development, differentiation, and metabolic processes. We asked whether endogenous fluctuations in a set of mRNA and miRNA profiles contain correlated changes that are statistically distinguishable from the many other fluctuations in the data set. Methodology/Principal Findings. RNA was extracted from 12 human primary brain tumor biopsies. These samples were used to determine genome-wide mRN

    HALT (Hernia Active Living Trial): protocol for a feasibility study of a randomised controlled trial of a physical activity intervention to improve quality of life in people with bowel stoma with a bulge/parastomal hernia

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    Background Parastomal hernia (PSH) can be repaired surgically, but results to date have been disappointing, with reported recurrence rates of 30 to 76%. Other types of intervention are therefore needed to improve the quality of life of people with PSH. One potential intervention is physical activity. We hypothesise that the intervention will increase core activation and control across the abdominal wall at a site of potential weakness and thus reduce the risk of PSH progression. Increases in physical activity will improve body image and quality of life (QoL). Methods Subjects and sample There were approximately 20 adults with a bowel stoma and PSH. People with previous PSH repair will be excluded as well as people who already do core training. Study design This is a feasibility study of a randomised controlled trial with 2 months follow-up, in 2 sites using mixed methods. Stage 1 involves intervention development and in stage 2, intervention and trial parameters will be assessed. Intervention A theoretically informed physical activity intervention was done, targeting people with PSH. Main outcome of feasibility study The main outcome is the decision by an independent Study Steering Committee whether to proceed to a full randomised controlled trial of the intervention. Other outcomes We will evaluate 4 intervention parameters—fidelity, adherence, acceptability and safety and 3 trial parameters (eligible patients’ consent rate, acceptability of study design and data availability rates for following endpoints): I. Diagnosis and classification of PSH II. Muscle activation III. Body composition (BMI, waist circumference) IV. Patient reported outcomes: QoL, body image and physical functioning V. Physical activity; VI. Psychological determinants of physical activity Other data Included are other data such as interviews with all participants about the intervention and trial procedures. Data analysis and statistical power As this is a feasibility study, the quantitative data will be analysed using descriptive statistics. Audio-recorded qualitative data from interviews will be transcribed verbatim and analysed thematically. Discussion The feasibility and acceptability of key intervention and trial parameters will be used to decide whether to proceed to a full trial of the intervention, which aims to improve body image, quality of life and PSH progression. Trial registration ISRCTN1520759

    Bone mineral density and fractures in older men with chronic obstructive pulmonary disease or asthma

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    In 5,541 community dwelling men, chronic obstructive pulmonary disease, or asthma was associated with lower bone mineral density (BMD) at the spine and total hip and an increased risk of vertebral and nonvertebral fractures independent of age, body mass index, and smoking. Men prescribed with corticosteroids had the lowest BMD. It is unclear whether chronic obstructive pulmonary disease (COPD) is independently associated with BMD and fractures. In 5,541 men from the Osteoporotic Fractures in Men Study, history of COPD or asthma, current treatment with corticosteroids, BMD, bone loss after 4.5 years and fractures were ascertained. Seven hundred fourteen (13%) men reported COPD or asthma, of which 103 were prescribed an oral steroid and 177 an inhaled steroid. Independent of confounders, men prescribed corticosteroids for COPD or asthma had the lowest BMD and a 2-fold increased risk of vertebral osteoporosis compared to men with no history of COPD or asthma (OR 2.13, 95% CI (confidence interval) 1.15–3.93 oral steroids; OR 2.05, 95% CI 1.27–3.31 inhaled steroids). During follow-up, BMD increased at the spine, but there was no difference in bone loss at the hip. However, men with COPD or asthma had a 2.6- and 1.4-fold increased risk of vertebral and nonvertebral fractures, respectively. Chronic obstructive pulmonary disease or asthma was associated with lower BMD at the spine and hip and increased risk of vertebral and nonvertebral fractures independent of age, clinic site, BMI, and smoking. A history of COPD or asthma may be a useful clinical risk factor to identify patients with osteoporosis

    The excess mortality risk of diabetes associated with functional decline in older adults: Results from a 7-year follow-up of a nationwide cohort in Taiwan

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    <p>Abstract</p> <p>Background</p> <p>Diabetes is associated with an increased risk of functional decline in older adults. Few studies have investigated the contribution of functional decline to excess mortality risk in older people with diabetes. The aim of this study was to examine how diabetes in combination with different levels of functional decline affects 7-year mortality in older adults.</p> <p>Methods</p> <p>We analyzed data from a nationally representative sample of people aged 65 years and over, participating in the 2001 National Health Interview Survey in Taiwan. A total of 1873 participants were followed through 2002-2008, of whom 286 (15.3%) had a history of diabetes confirmed by a medical professional. Participants were divided into three functional status groups: (1) high functioning-no limitations involving activities of daily living (ADLs), instrumental activities of daily living (IADLs), or physical functioning; (2) low functioning-limitations in one or more ADLs; (3) middle functioning-all participants in between groups 1 and 2.</p> <p>Results</p> <p>The crude mortality rate was 52.7 per 1,000 person-years in those with diabetes and 34.1 per 1,000 person-years in those without diabetes. After adjustment for other factors, diabetes alone was not associated with an increased mortality risk in those with high functioning. However, diabetes alone had a hazard ratio (HR) for mortality of 1.90 (95%CI = [1.02-3.53]) in those with middle functioning and 3.67 (95%CI = [1.55-8.69]) in those with low functioning. The presence of diabetes and one or more other chronic conditions was associated with a HR for mortality of 2.46 (95%CI = [1.61-3.77]) in those with middle functioning and 4.03 (95%CI = [2.31-7.03]) in those with low functioning.</p> <p>Conclusions</p> <p>Our results indicate that diabetes is not associated with increased mortality in those with high functioning. There was a gradient effect of functional decline on mortality in individuals with diabetes. Additionally, among participants with other chronic conditions, functional decline was associated with a greater burden of mortality in older adults with diabetes. These findings highlight the critical importance of the prevention of cardiovascular disease morbidity and the maintenance of functional abilities in order to reduce mortality risk in older adults with diabetes.</p

    Effects of thymic selection of the T cell repertoire on HLA-class I associated control of HIV infection

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    Without therapy, most people infected with human immunodeficiency virus (HIV) ultimately progress to AIDS. Rare individuals (‘elite controllers’) maintain very low levels of HIV RNA without therapy, thereby making disease progression and transmission unlikely. Certain HLA class I alleles are markedly enriched in elite controllers, with the highest association observed for HLA-B57 (ref. 1). Because HLA molecules present viral peptides that activate CD8+ T cells, an immune-mediated mechanism is probably responsible for superior control of HIV. Here we describe how the peptide-binding characteristics of HLA-B57 molecules affect thymic development such that, compared to other HLA-restricted T cells, a larger fraction of the naive repertoire of B57-restricted clones recognizes a viral epitope, and these T cells are more cross-reactive to mutants of targeted epitopes. Our calculations predict that such a T-cell repertoire imposes strong immune pressure on immunodominant HIV epitopes and emergent mutants, thereby promoting efficient control of the virus. Supporting these predictions, in a large cohort of HLA-typed individuals, our experiments show that the relative ability of HLA-B alleles to control HIV correlates with their peptide-binding characteristics that affect thymic development. Our results provide a conceptual framework that unifies diverse empirical observations, and have implications for vaccination strategies.Mark and Lisa Schwartz FoundationNational Institutes of Health (U.S.) (Director’s Pioneer award)Philip T. and Susan M. Ragon FoundationJane Coffin Childs Memorial Fund for Medical ResearchBill & Melinda Gates FoundationNational Institute of Allergy and Infectious Diseases (U.S.)National Institutes of Health (U.S.) (contract no. HHSN261200800001E)National Institutes of Health (U.S.). Intramural Research ProgramNational Cancer Institute (U.S.)Center for Cancer Research (National Cancer Institute (U.S.)

    Photo-enhanced antinodal conductivity in the pseudogap state of high-T-c cuprates

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    A major challenge in understanding the cuprate superconductors is to clarify the nature of the fundamental electronic correlations that lead to the pseudogap phenomenon. Here we use ultrashort light pulses to prepare a non-thermal distribution of excitations and capture novel properties that are hidden at equilibrium. Using a broadband (0.5-2 eV) probe, we are able to track the dynamics of the dielectric function and unveil an anomalous decrease in the scattering rate of the charge carriers in a pseudogap-like region of the temperature (T) and hole-doping (p) phase diagram. In this region, delimited by a well-defined T*(neq)(p) line, the photoexcitation process triggers the evolution of antinodal excitations from gapped (localized) to delocalized quasiparticles characterized by a longer lifetime. The novel concept of photo-enhanced antinodal conductivity is naturally explained within the singleband Hubbard model, in which the short-range Coulomb repulsion leads to a k-space differentiation between nodal quasiparticles and antinodal excitations. \ua9 2014 Macmillan Publishers Limited. All rights reserved

    Width of Gene Expression Profile Drives Alternative Splicing

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    Alternative splicing generates an enormous amount of functional and proteomic diversity in metazoan organisms. This process is probably central to the macromolecular and cellular complexity of higher eukaryotes. While most studies have focused on the molecular mechanism triggering and controlling alternative splicing, as well as on its incidence in different species, its maintenance and evolution within populations has been little investigated. Here, we propose to address these questions by comparing the structural characteristics as well as the functional and transcriptional profiles of genes with monomorphic or polymorphic splicing, referred to as MS and PS genes, respectively. We find that MS and PS genes differ particularly in the number of tissues and cell types where they are expressed.We find a striking deficit of PS genes on the sex chromosomes, particularly on the Y chromosome where it is shown not to be due to the observed lower breadth of expression of genes on that chromosome. The development of a simple model of evolution of cis-regulated alternative splicing leads to predictions in agreement with these observations. It further predicts the conditions for the emergence and the maintenance of cis-regulated alternative splicing, which are both favored by the tissue specific expression of splicing variants. We finally propose that the width of the gene expression profile is an essential factor for the acquisition of new transcript isoforms that could later be maintained by a new form of balancing selection
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