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Showing papers by "Medical Research Council published in 2012"


Journal ArticleDOI
Rafael Lozano1, Mohsen Naghavi1, Kyle J Foreman2, Stephen S Lim1  +192 moreInstitutions (95)
TL;DR: The Global Burden of Diseases, Injuries, and Risk Factors Study 2010 aimed to estimate annual deaths for the world and 21 regions between 1980 and 2010 for 235 causes, with uncertainty intervals (UIs), separately by age and sex, using the Cause of Death Ensemble model.

11,809 citations


Journal ArticleDOI
TL;DR: In this paper, the authors describe physical activity levels worldwide with data for adults (15 years or older) from 122 countries and for adolescents (13-15-years-old) from 105 countries.

4,373 citations


Journal ArticleDOI
TL;DR: These guidelines are presented for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes.
Abstract: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.

4,316 citations


Journal ArticleDOI
25 May 2012-Cell
TL;DR: This work generated catalogs of somatic mutation from 21 breast cancers and applied mathematical methods to extract mutational signatures of the underlying processes, finding a remarkable phenomenon of localized hypermutation, termed “kataegis,” was observed.

1,699 citations


Journal ArticleDOI
TL;DR: It is found that episodic selection is widespread and it is concluded that the number of sites experiencing positive selection may have been vastly underestimated.
Abstract: The imprint of natural selection on protein coding genes is often difficult to identify because selection is frequently transient or episodic, i.e. it affects only a subset of lineages. Existing computational techniques, which are designed to identify sites subject to pervasive selection, may fail to recognize sites where selection is episodic: a large proportion of positively selected sites. We present a mixed effects model of evolution (MEME) that is capable of identifying instances of both episodic and pervasive positive selection at the level of an individual site. Using empirical and simulated data, we demonstrate the superior performance of MEME over older models under a broad range of scenarios. We find that episodic selection is widespread and conclude that the number of sites experiencing positive selection may have been vastly underestimated.

1,327 citations


Journal ArticleDOI
TL;DR: Progress in understanding the structure and function of HGF/SF, MET and associated signalling components has led to the successful development of blocking antibodies and a large number of small-molecule MET kinase inhibitors, as well as results from recent clinical studies that demonstrate that inhibiting MET signalling in several types of solid human tumours has major therapeutic value.
Abstract: Uncontrolled cell survival, growth, angiogenesis and metastasis are essential hallmarks of cancer. Genetic and biochemical data have demonstrated that the growth and motility factor hepatocyte growth factor/scatter factor (HGF/SF) and its receptor, the tyrosine kinase MET, have a causal role in all of these processes, thus providing a strong rationale for targeting these molecules in cancer. Parallel progress in understanding the structure and function of HGF/SF, MET and associated signalling components has led to the successful development of blocking antibodies and a large number of small-molecule MET kinase inhibitors. In this Review, we discuss these advances, as well as results from recent clinical studies that demonstrate that inhibiting MET signalling in several types of solid human tumours has major therapeutic value.

1,180 citations


Journal ArticleDOI
TL;DR: GCaMP5 fluorescence provides a more reliable measure of neuronal activity than its predecessor GCaMP3, which allows more sensitive detection of neural activity in vivo and may find widespread applications for cellular imaging in general.
Abstract: Genetically encoded calcium indicators (GECIs) are powerful tools for systems neuroscience. Recent efforts in protein engineering have significantly increased the performance of GECIs. The state-of-the art single-wavelength GECI, GCaMP3, has been deployed in a number of model organisms and can reliably detect three or more action potentials in short bursts in several systems in vivo. Through protein structure determination, targeted mutagenesis, high-throughput screening, and a battery of in vitro assays, we have increased the dynamic range of GCaMP3 by severalfold, creating a family of “GCaMP5” sensors. We tested GCaMP5s in several systems: cultured neurons and astrocytes, mouse retina, and in vivo in Caenorhabditis chemosensory neurons, Drosophila larval neuromuscular junction and adult antennal lobe, zebrafish retina and tectum, and mouse visual cortex. Signal-to-noise ratio was improved by at least 2- to 3-fold. In the visual cortex, two GCaMP5 variants detected twice as many visual stimulus-responsive cells as GCaMP3. By combining in vivo imaging with electrophysiology we show that GCaMP5 fluorescence provides a more reliable measure of neuronal activity than its predecessor GCaMP3. GCaMP5 allows more sensitive detection of neural activity in vivo and may find widespread applications for cellular imaging in general.

1,179 citations


Journal ArticleDOI
TL;DR: The global number of deaths during the first 12 months of virus circulation in each country and the estimate of respiratory and cardiovascular mortality associated with the 2009 pandemic influenza A H1N1 was 15 times higher than reported laboratory-confirmed deaths.
Abstract: Summary Background 18 500 laboratory-confirmed deaths caused by the 2009 pandemic influenza A H1N1 were reported worldwide for the period April, 2009, to August, 2010. This number is likely to be only a fraction of the true number of the deaths associated with 2009 pandemic influenza A H1N1. We aimed to estimate the global number of deaths during the first 12 months of virus circulation in each country. Methods We calculated crude respiratory mortality rates associated with the 2009 pandemic influenza A H1N1 strain by age (0–17 years, 18–64 years, and >64 years) using the cumulative (12 months) virus-associated symptomatic attack rates from 12 countries and symptomatic case fatality ratios (sCFR) from five high-income countries. To adjust crude mortality rates for differences between countries in risk of death from influenza, we developed a respiratory mortality multiplier equal to the ratio of the median lower respiratory tract infection mortality rate in each WHO region mortality stratum to the median in countries with very low mortality. We calculated cardiovascular disease mortality rates associated with 2009 pandemic influenza A H1N1 infection with the ratio of excess deaths from cardiovascular and respiratory diseases during the pandemic in five countries and multiplied these values by the crude respiratory disease mortality rate associated with the virus. Respiratory and cardiovascular mortality rates associated with 2009 pandemic influenza A H1N1 were multiplied by age to calculate the number of associated deaths. Findings We estimate that globally there were 201 200 respiratory deaths (range 105 700–395 600) with an additional 83 300 cardiovascular deaths (46 000–179 900) associated with 2009 pandemic influenza A H1N1. 80% of the respiratory and cardiovascular deaths were in people younger than 65 years and 51% occurred in southeast Asia and Africa. Interpretation Our estimate of respiratory and cardiovascular mortality associated with the 2009 pandemic influenza A H1N1 was 15 times higher than reported laboratory-confirmed deaths. Although no estimates of sCFRs were available from Africa and southeast Asia, a disproportionate number of estimated pandemic deaths might have occurred in these regions. Therefore, efforts to prevent influenza need to effectively target these regions in future pandemics. Funding None.

1,170 citations


Journal ArticleDOI
Joshua A. Salomon1, Theo Vos, Daniel R Hogan1, Michael L. Gagnon1, Mohsen Naghavi2, Ali Mokdad2, Nazma Begum3, Razibuzzaman Shah1, Muhammad Karyana, Soewarta Kosen, Mario Reyna Farje, Gilberto Moncada, Arup Dutta, Sunil Sazawal, Andrew Dyer4, Jason F. S. Seiler4, Victor Aboyans, Lesley Baker2, Amanda J Baxter5, Emelia J. Benjamin6, Kavi Bhalla1, Aref A. Bin Abdulhak, Fiona M. Blyth, Rupert R A Bourne, Tasanee Braithwaite7, Peter Brooks, Traolach S. Brugha8, Claire Bryan-Hancock, Rachelle Buchbinder, Peter Burney9, Bianca Calabria10, Honglei Chen11, Sumeet S. Chugh12, Rebecca Cooley2, Michael H. Criqui13, Marita Cross5, Kaustubh Dabhadkar, Nabila Dahodwala14, Adrian Davis15, Louisa Degenhardt16, Cesar Diaz-Torne17, E. Ray Dorsey3, Tim Driscoll, Karen Edmond18, Alexis Elbaz19, Majid Ezzati20, Valery L. Feigin21, Cleusa P. Ferri22, Abraham D. Flaxman2, Louise Flood8, Marlene Fransen, Kana Fuse, Belinda J. Gabbe23, Richard F. Gillum24, Juanita A. Haagsma25, James Harrison8, Rasmus Havmoeller16, Roderick J. Hay26, Abdullah Hel-Baqui, Hans W. Hoek27, Howard J. Hoffman28, Emily Hogeland29, Damian G Hoy5, Deborah Jarvis2, Ganesan Karthikeyan1, Lisa M. Knowlton30, Tim Lathlean8, Janet L Leasher31, Stephen S Lim2, Steven E. Lipshultz32, Alan D. Lopez, Rafael Lozano2, Ronan A Lyons33, Reza Malekzadeh, Wagner Marcenes, Lyn March6, David J. Margolis14, Neil McGill, John J. McGrath34, George A. Mensah35, Ana-Claire Meyer, Catherine Michaud36, Andrew E. Moran, Rintaro Mori37, Michele E. Murdoch38, Luigi Naldi39, Charles R. Newton12, Rosana E. Norman, Saad B. Omer40, Richard H. Osborne, Neil Pearce18, Fernando Perez-Ruiz, Norberto Perico41, Konrad Pesudovs8, David Phillips42, Farshad Pourmalek43, Martin Prince, Jürgen Rehm, G. Remuzzi41, Kathryn Richardson, Robin Room44, Sukanta Saha45, Uchechukwu Sampson, Lidia Sanchez-Riera46, Maria Segui-Gomez47, Saeid Shahraz48, Kenji Shibuya, David Singh49, Karen Sliwa50, Emma Smith50, Isabelle Soerjomataram51, Timothy J. Steiner, Wilma A. Stolk, Lars Jacob Stovner, Christopher R. Sudfeld1, Hugh R. Taylor, Imad M. Tleyjeh4, Marieke J. van der Werf52, Wendy L. Watson53, David J. Weatherall12, Robert G. Weintraub, Marc G. Weisskopf1, Harvey Whiteford, James D. Wilkinson32, Anthony D. Woolf52, Zhi-Jie Zheng54, Christopher J L Murray2 
Harvard University1, University of Queensland2, Johns Hopkins University3, ICF International4, Centre for Mental Health5, Boston University6, University of Sydney7, University of Melbourne8, Imperial College London9, University of New South Wales10, University of California, San Diego11, Emory University12, University of Pennsylvania13, Autonomous University of Barcelona14, University of London15, National Institutes of Health16, French Institute of Health and Medical Research17, Medical Research Council18, Auckland University of Technology19, Federal University of São Paulo20, National Institute of Population and Social Security Research21, Howard University22, Flinders University23, Erasmus University Rotterdam24, King's College London25, Karolinska Institutet26, University of California, San Francisco27, All India Institute of Medical Sciences28, Nova Southeastern University29, University of Miami30, Swansea University31, Tehran University of Medical Sciences32, Queen Mary University of London33, Allen Institute for Brain Science34, University of Cape Town35, Columbia University36, Watford General Hospital37, Centro Studi GISED38, University of Oxford39, Deakin University40, University of British Columbia41, University of Toronto42, Box Hill Hospital43, Vanderbilt University44, University of Washington45, Brandeis University46, University of Tokyo47, The Queen's Medical Center48, Norwegian University of Science and Technology49, China Medical Board50, University of Cambridge51, Royal Cornwall Hospital52, Cedars-Sinai Medical Center53, Shanghai Jiao Tong University54
TL;DR: In this paper, a comprehensive re-estimation of disability weights for the Global Burden of Disease Study 2010 through a large-scale empirical investigation in which judgments about health losses associated with many causes of disease and injury were elicited from the general public in diverse communities through a new, standardised approach.

1,130 citations


Journal ArticleDOI
Stephen Kaptoge1, Emanuele Di Angelantonio1, Lisa Pennells1, Angela M. Wood1, Ian R. White2, Pei Gao1, Matthew G. Walker1, Alexander M. W. Cargill Thompson1, Nadeem Sarwar1, Muriel J. Caslake3, Adam S. Butterworth1, Philippe Amouyel4, Gerd Assmann, Stephan J. L. Bakker5, Elizabeth L M Barr6, Elizabeth Barrett-Connor7, Emelia J. Benjamin8, Cecilia Björkelund9, Hermann Brenner10, Eric J. Brunner11, Robert Clarke12, Jackie A. Cooper11, Peter Cremer13, Mary Cushman14, Gilles R. Dagenais, Ralph B. D'Agostino8, Rachel Dankner, George Davey-Smith15, Dorly J. H. Deeg16, Jacqueline M. Dekker16, Gunnar Engström17, Aaron R. Folsom18, F. Gerry R. Fowkes19, John Gallacher20, J. Michael Gaziano21, Simona Giampaoli22, Richard F. Gillum23, Albert Hofman24, Barbara V. Howard25, Erik Ingelsson26, Hiroyasu Iso27, Torben Jørgensen28, Stefan Kiechl29, Akihiko Kitamura, Yutaka Kiyohara30, Wolfgang Koenig31, Daan Kromhout32, Lewis H. Kuller33, Debbie A Lawlor15, Tom W. Meade34, Aulikki Nissinen35, Børge G. Nordestgaard28, Altan Onat36, Demosthenes B. Panagiotakos37, Bruce M. Psaty38, Beatriz L. Rodriguez39, Annika Rosengren9, Veikko Salomaa35, Jussi Kauhanen40, Jukka T. Salonen41, Jonathan A. Shaffer42, Steven Shea42, Ian Ford3, Coen D.A. Stehouwer43, Timo E. Strandberg44, Robert W. Tipping45, Alberto Tosetto, Sylvia Wassertheil-Smoller46, Patrik Wennberg47, Rudi G. J. Westendorp48, Peter H. Whincup49, Lars Wilhelmsen9, Mark Woodward50, Gordon D.O. Lowe3, Nicholas J. Wareham2, Kay-Tee Khaw1, Naveed Sattar3, Chris J. Packard3, Vilmundur Gudnason51, Paul M. Ridker21, Mark B. Pepys11, Simon G. Thompson1, John Danesh1 
TL;DR: It is estimated that under current treatment guidelines, assessment of the CRP or fibrinogen level in people at intermediate risk for a cardiovascular event could help prevent one additional event over a period of 10 years for every 400 to 500 people screened.
Abstract: Background There is debate about the value of assessing levels of C-reactive protein (CRP) and other biomarkers of inflammation for the prediction of first cardiovascular events. Methods We analyzed data from 52 prospective studies that included 246,669 participants without a history of cardiovascular disease to investigate the value of adding CRP or fibrinogen levels to conventional risk factors for the prediction of cardiovascular risk. We calculated measures of discrimination and reclassification during follow-up and modeled the clinical implications of initiation of statin therapy after the assessment of CRP or fibrinogen. Results The addition of information on high-density lipoprotein cholesterol to a prognostic model for cardiovascular disease that included age, sex, smoking status, blood pressure, history of diabetes, and total cholesterol level increased the C-index, a measure of risk discrimination, by 0.0050. The further addition to this model of information on CRP or fibrinogen increased the C-index by 0.0039 and 0.0027, respectively (P = 20%) (P = 20% and for those with certain other risk factors, such as diabetes, irrespective of their 10-year predicted risk), additional targeted assessment of CRP or fibrinogen levels in the 13,199 remaining participants at intermediate risk could help prevent approximately 30 additional cardiovascular events over the course of 10 years. Conclusions In a study of people without known cardiovascular disease, we estimated that under current treatment guidelines, assessment of the CRP or fibrinogen level in people at intermediate risk for a cardiovascular event could help prevent one additional event over a period of 10 years for every 400 to 500 people screened. (Funded by the British Heart Foundation and others.)

938 citations


Journal ArticleDOI
01 May 2012-Heart
TL;DR: An overview is provided of the consecutive steps for the assessment of the model's predictive performance in new individuals, how to adjust or update existing models to local circumstances or with new predictors, and how to investigate the impact of the uptake of prediction models on clinical decision-making and patient outcomes (impact studies).
Abstract: Clinical prediction models are increasingly used to complement clinical reasoning and decision-making in modern medicine, in general, and in the cardiovascular domain, in particular. To these ends, developed models first and foremost need to provide accurate and (internally and externally) validated estimates of probabilities of specific health conditions or outcomes in the targeted individuals. Subsequently, the adoption of such models by professionals must guide their decision-making, and improve patient outcomes and the cost-effectiveness of care. In the first paper of this series of two companion papers, issues relating to prediction model development, their internal validation, and estimating the added value of a new (bio)marker to existing predictors were discussed. In this second paper, an overview is provided of the consecutive steps for the assessment of the model's predictive performance in new individuals (external validation studies), how to adjust or update existing models to local circumstances or with new predictors, and how to investigate the impact of the uptake of prediction models on clinical decision-making and patient outcomes (impact studies). Each step is illustrated with empirical examples from the cardiovascular field.

Journal ArticleDOI
Daniel I. Swerdlow1, Michael V. Holmes1, Karoline Kuchenbaecker2, Engmann Jel.1, Tina Shah1, Reecha Sofat1, Yiran Guo, C Chung1, Anne Peasey1, Roman Pfister3, Simon P. Mooijaart4, Helen Ireland1, Maarten Leusink5, Claudia Langenberg3, KaWah Li1, Jutta Palmen1, Phil Howard1, Jackie A. Cooper1, Fotios Drenos1, John Hardy1, Mike A. Nalls6, Yun Li7, Gordon D.O. Lowe8, Marlene C. W. Stewart9, S. J. Bielinski10, Julian Peto11, Nicholas J. Timpson12, John Gallacher13, Malcolm G. Dunlop9, Richard S. Houlston, Ian Tomlinson14, Ioanna Tzoulaki15, Jian'an Luan2, Boer Jma.2, Nita G. Forouhi2, N. C. Onland-Moret5, Y. T. van der Schouw16, Renate B. Schnabel16, Jaroslav A. Hubacek, Růžena Kubínová, Migle Baceviciene17, Abdonas Tamosiunas17, Andrzej Pajak18, Roman Topor-Madry18, Sofia Malyutina19, Damiano Baldassarre, Bengt Sennblad20, Elena Tremoli, U de Faire21, Luigi Ferrucci21, S Bandenelli, Tetsu Tanaka21, James F. Meschia10, AB Singleton6, Gerjan Navis22, I. Mateo Leach22, Bakker Sjl.22, Ron T. Gansevoort, Ian Ford8, Stephen E. Epstein23, Mary-Susan Burnett23, Joe Devaney23, Johan Wouter Jukema4, Westendorp Rgj.5, G Jan de Borst5, Y. van der Graaf5, P A de Jong5, Mailand-van der Zee A-H.5, Olaf H. Klungel5, A. de Boer5, P. A. Doevendans5, Jeffrey W. Stephens24, Charles B. Eaton25, Jennifer G. Robinson26, JoAnn E. Manson27, F G Fowkes28, Timothy M. Frayling28, Jenna Price9, Peter H. Whincup11, Richard W Morris1, Debbie A Lawlor12, George Davey Smith12, Yoav Ben-Shlomo12, Susan Redline27, Leslie A. Lange29, Meena Kumari1, Nicholas J. Wareham2, Verschuren Wmm.30, Emelia J. Benjamin30, John C. Whittaker11, Anders Hamsten20, Frank Dudbridge11, Delaney Jac.31, Andrew Wong31, Diana Kuh31, Rebecca Hardy31, Berta Almoguera Castillo7, John Connolly7, P. van der Harst, Eric J. Brunner1, Michael Marmot1, Christina L. Wassel32, Steve E. Humphries1, P.J. Talmud1, Mika Kivimäki1, Folkert W. Asselbergs5, Mikhail I. Voevoda19, Martin Bobak1, Hynek Pikhart1, James G. Wilson33, Hakon Hakonarson7, Alexander P. Reiner34, Brendan J. Keating7, Naveed Sattar8, Aroon D. Hingorani1, Juan P. Casas11 
TL;DR: IL6R blockade could provide a novel therapeutic approach to prevention of coronary heart disease that warrants testing in suitably powered randomised trials and could help to validate and prioritise novel drug targets or to repurpose existing agents and targets for new therapeutic uses.

Journal ArticleDOI
TL;DR: It is shown that at least 40% of the total heritable cis effect on expression cannot be accounted for by common cis variants, a finding that reveals the contribution of low-frequency and rare regulatory variants with respect to both transcriptional regulation and complex trait susceptibility.
Abstract: Sequence-based variation in gene expression is a key driver of disease risk. Common variants regulating expression in cis have been mapped in many expression quantitative trait locus (eQTL) studies, typically in single tissues from unrelated individuals. Here, we present a comprehensive analysis of gene expression across multiple tissues conducted in a large set of mono- and dizygotic twins that allows systematic dissection of genetic (cis and trans) and non-genetic effects on gene expression. Using identity-by-descent estimates, we show that at least 40% of the total heritable cis effect on expression cannot be accounted for by common cis variants, a finding that reveals the contribution of low-frequency and rare regulatory variants with respect to both transcriptional regulation and complex trait susceptibility. We show that a substantial proportion of gene expression heritability is trans to the structural gene, and we identify several replicating trans variants that act predominantly in a tissue-restricted manner and may regulate the transcription of many genes.

Journal ArticleDOI
TL;DR: The restorative macrophage phenotype was recapitulated in vitro by the phagocytosis of cellular debris with associated activation of the ERK signaling cascade, offering a therapeutic strategy to this orphan pathological process.
Abstract: Although macrophages are widely recognized to have a profibrotic role in inflammation, we have used a highly tractable CCl4-induced model of reversible hepatic fibrosis to identify and characterize the macrophage phenotype responsible for tissue remodeling: the hitherto elusive restorative macrophage. This CD11Bhi F4/80int Ly-6Clo macrophage subset was most abundant in livers during maximal fibrosis resolution and represented the principle matrix metalloproteinase (MMP) -expressing subset. Depletion of this population in CD11B promoter–diphtheria toxin receptor (CD11B-DTR) transgenic mice caused a failure of scar remodeling. Adoptive transfer and in situ labeling experiments showed that these restorative macrophages derive from recruited Ly-6Chi monocytes, a common origin with profibrotic Ly-6Chi macrophages, indicative of a phenotypic switch in vivo conferring proresolution properties. Microarray profiling of the Ly-6Clo subset, compared with Ly-6Chi macrophages, showed a phenotype outside the M1/M2 classification, with increased expression of MMPs, growth factors, and phagocytosis-related genes, including Mmp9, Mmp12, insulin-like growth factor 1 (Igf1), and Glycoprotein (transmembrane) nmb (Gpnmb). Confocal microscopy confirmed the postphagocytic nature of restorative macrophages. Furthermore, the restorative macrophage phenotype was recapitulated in vitro by the phagocytosis of cellular debris with associated activation of the ERK signaling cascade. Critically, induced phagocytic behavior in vivo, through administration of liposomes, increased restorative macrophage number and accelerated fibrosis resolution, offering a therapeutic strategy to this orphan pathological process.

Journal ArticleDOI
01 May 2012-Heart
TL;DR: This first article focuses on the different aspects of model development studies, from design to reporting, how to estimate a model's predictive performance and the potential optimism in these estimates using internal validation techniques, and how to quantify the added or incremental value of new predictors or biomarkers to existing predictors.
Abstract: Prediction models are increasingly used to complement clinical reasoning and decision making in modern medicine in general, and in the cardiovascular domain in particular. Developed models first and foremost need to provide accurate and (internally and externally) validated estimates of probabilities of specific health conditions or outcomes in targeted patients. The adoption of such models must guide physician's decision making and an individual's behaviour, and consequently improve individual outcomes and the cost-effectiveness of care. In a series of two articles we review the consecutive steps generally advocated for risk prediction model research. This first article focuses on the different aspects of model development studies, from design to reporting, how to estimate a model's predictive performance and the potential optimism in these estimates using internal validation techniques, and how to quantify the added or incremental value of new predictors or biomarkers (of whatever type) to existing predictors. Each step is illustrated with empirical examples from the cardiovascular field.

Journal ArticleDOI
TL;DR: Adding shear-wave (SW) elastographic features to BI-RADS feature analysis improved specificity of breast US mass assessment without loss of sensitivity.
Abstract: Adding consideration of mass stiffness, as determined with shear-wave elastographic qualitative or quantitative features, can help reduce unnecessary biopsies of low-suspicion Breast Imaging Reporting and Data System category 4a masses.

Journal ArticleDOI
06 Jul 2012-Science
TL;DR: The existence of a specific mitochondrial pyruvate carrier (MPC) has been anticipated, but its molecular identity remained unknown and it is reported that MPC is a heterocomplex formed by two members of a family of previously uncharacterized membrane proteins that are conserved from yeast to mammals.
Abstract: The transport of pyruvate, the end product of glycolysis, into mitochondria is an essential process that provides the organelle with a major oxidative fuel. Although the existence of a specific mitochondrial pyruvate carrier (MPC) has been anticipated, its molecular identity remained unknown. We report that MPC is a heterocomplex formed by two members of a family of previously uncharacterized membrane proteins that are conserved from yeast to mammals. Members of the MPC family were found in the inner mitochondrial membrane, and yeast mutants lacking MPC proteins showed severe defects in mitochondrial pyruvate uptake. Coexpression of mouse MPC1 and MPC2 in Lactococcus lactis promoted transport of pyruvate across the membrane. These observations firmly establish these proteins as essential components of the MPC.

Journal ArticleDOI
TL;DR: In this article, the authors report genome-wide association meta-analyses and replication for mean bilateral hippocampal, total brain and intracranial volumes from a large multinational consortium.
Abstract: Identifying genetic variants influencing human brain structures may reveal new biological mechanisms underlying cognition and neuropsychiatric illness. The volume of the hippocampus is a biomarker of incipient Alzheimer's disease and is reduced in schizophrenia, major depression and mesial temporal lobe epilepsy. Whereas many brain imaging phenotypes are highly heritable, identifying and replicating genetic influences has been difficult, as small effects and the high costs of magnetic resonance imaging (MRI) have led to underpowered studies. Here we report genome-wide association meta-analyses and replication for mean bilateral hippocampal, total brain and intracranial volumes from a large multinational consortium. The intergenic variant rs7294919 was associated with hippocampal volume (12q24.22; N = 21,151; P = 6.70 × 10(-16)) and the expression levels of the positional candidate gene TESC in brain tissue. Additionally, rs10784502, located within HMGA2, was associated with intracranial volume (12q14.3; N = 15,782; P = 1.12 × 10(-12)). We also identified a suggestive association with total brain volume at rs10494373 within DDR2 (1q23.3; N = 6,500; P = 5.81 × 10(-7)).

Journal ArticleDOI
TL;DR: An updated systematic review of the reliability and validity characteristics of existing and more recently developed physical activity questionnaires and to quantitatively compare the performance between existing and newly developed PAQs is provided.
Abstract: Physical inactivity is one of the four leading risk factors for global mortality. Accurate measurement of physical activity (PA) and in particular by physical activity questionnaires (PAQs) remains a challenge. The aim of this paper is to provide an updated systematic review of the reliability and validity characteristics of existing and more recently developed PAQs and to quantitatively compare the performance between existing and newly developed PAQs. A literature search of electronic databases was performed for studies assessing reliability and validity data of PAQs using an objective criterion measurement of PA between January 1997 and December 2011. Articles meeting the inclusion criteria were screened and data were extracted to provide a systematic overview of measurement properties. Due to differences in reported outcomes and criterion methods a quantitative meta-analysis was not possible. In total, 31 studies testing 34 newly developed PAQs, and 65 studies examining 96 existing PAQs were included. Very few PAQs showed good results on both reliability and validity. Median reliability correlation coefficients were 0.62–0.71 for existing, and 0.74–0.76 for new PAQs. Median validity coefficients ranged from 0.30–0.39 for existing, and from 0.25–0.41 for new PAQs. Although the majority of PAQs appear to have acceptable reliability, the validity is moderate at best. Newly developed PAQs do not appear to perform substantially better than existing PAQs in terms of reliability and validity. Future PAQ studies should include measures of absolute validity and the error structure of the instrument.

Journal ArticleDOI
09 Nov 2012-Science
TL;DR: It is described how hepcidin integrates signals from diverse physiological inputs, forming a key molecular bridge between iron trafficking and response to infection.
Abstract: Iron lies at the center of a battle for nutritional resource between higher organisms and their microbial pathogens. The iron status of the human host affects the pathogenicity of numerous infections including malaria, HIV-1, and tuberculosis. Hepcidin, an antimicrobial-like peptide hormone, has emerged as the master regulator of iron metabolism. Hepcidin controls the absorption of dietary iron and the distribution of iron among cell types in the body, and its synthesis is regulated by both iron and innate immunity. We describe how hepcidin integrates signals from diverse physiological inputs, forming a key molecular bridge between iron trafficking and response to infection.

Journal ArticleDOI
TL;DR: A series of consensus documents called International Consensus ON (ICON) are being developed to serve as an important resource and support physicians in managing different allergic diseases.
Abstract: Food allergies can result in life-threatening reactions and diminish quality of life. In the last several decades, the prevalence of food allergies has increased in several regions throughout the world. Although more than 170 foods have been identified as being potentially allergenic, a minority of these foods cause the majority of reactions, and common food allergens vary between geographic regions. Treatment of food allergy involves strict avoidance of the trigger food. Medications manage symptoms of disease, but currently, there is no cure for food allergy. In light of the increasing burden of allergic diseases, the American Academy of Allergy, Asthma & Immunology; European Academy of Allergy and Clinical Immunology; World Allergy Organization; and American College of Allergy, Asthma & Immunology have come together to increase the communication of information about allergies and asthma at a global level. Within the framework of this collaboration, termed the International Collaboration in Asthma, Allergy and Immunology, a series of consensus documents called International Consensus ON (ICON) are being developed to serve as an important resource and support physicians in managing different allergic diseases. An author group was formed to describe the natural history, prevalence, diagnosis, and treatment of food allergies in the context of the global community.

Journal ArticleDOI
TL;DR: Transformation of the health system into a national institution that is based on equity and merit and is built on an effective human-resources system could still place South Africa on track to achieve Millennium Development Goals 4, 5, and 6 and would enhance the lives of its citizens.

Journal ArticleDOI
TL;DR: The genetic contribution to BMI appears to vary with age and may have a greater influence during childhood than adult life, and study design factors explained nearly half the heterogeneity reported in twin studies.
Abstract: Evidence for a major role of genetic factors in the determination of body mass index (BMI) comes from studies of related individuals. However, heritability estimates for BMI vary widely between studies and the reasons for this remain unclear. While some variation is natural due to differences between populations and settings, study design factors may also explain some of the heterogeneity. We performed a systematic review that identified eighty-eight independent estimates of BMI heritability from twin studies (total 140,525 twins) and twenty-seven estimates from family studies (42,968 family members). BMI heritability estimates from twin studies ranged from 0.47 to 0.90 (5th/50th/95th centiles: 0.58/0.75/0.87) and were generally higher than those from family studies (range: 0.24-0.81; 5th/50th/95th centiles: 0.25/0.46/0.68). Meta-regression of the results from twin studies showed that BMI heritability estimates were 0.07 (P=0.001) higher in children than in adults; estimates increased with mean age among childhood studies (+0.012 per year, P=0.002), but decreased with mean age in adult studies (-0.002 per year, P=0.002). Heritability estimates derived from AE twin models (which assume no contribution of shared environment) were 0.12 higher than those from ACE models (P<0.001), whilst lower estimates were associated with self-reported versus DNA-based determination of zygosity (-0.04, P=0.02), and with self-reported versus measured BMI (-0.05, P=0.03). Together, the above factors explained 47% of the heterogeneity in estimates of BMI heritability from twin studies. In summary, while some variation in BMI heritability is expected due to population-level differences, study design factors explained nearly half the heterogeneity reported in twin studies. The genetic contribution to BMI appears to vary with age and may have a greater influence during childhood than adult life.

Journal ArticleDOI
TL;DR: Findings from a collaborative, individual patient-level meta-analysis of treatment outcomes among patients with multidrug-resistant tuberculosis are reported.
Abstract: Background Treatment of multidrug resistant tuberculosis (MDR-TB) is lengthy, toxic, expensive, and has generally poor outcomes. We undertook an individual patient data meta-analysis to assess the impact on outcomes of the type, number, and duration of drugs used to treat MDR-TB. Methods and Findings Three recent systematic reviews were used to identify studies reporting treatment outcomes of microbiologically confirmed MDR-TB. Study authors were contacted to solicit individual patient data including clinical characteristics, treatment given, and outcomes. Random effects multivariable logistic meta-regression was used to estimate adjusted odds of treatment success. Adequate treatment and outcome data were provided for 9,153 patients with MDR-TB from 32 observational studies. Treatment success, compared to failure/relapse, was associated with use of: later generation quinolones, (adjusted odds ratio [aOR]: 2.5 [95% CI 1.1–6.0]), ofloxacin (aOR: 2.5 [1.6–3.9]), ethionamide or prothionamide (aOR: 1.7 [1.3–2.3]), use of four or more likely effective drugs in the initial intensive phase (aOR: 2.3 [1.3–3.9]), and three or more likely effective drugs in the continuation phase (aOR: 2.7 [1.7–4.1]). Similar results were seen for the association of treatment success compared to failure/relapse or death: later generation quinolones, (aOR: 2.7 [1.7–4.3]), ofloxacin (aOR: 2.3 [1.3–3.8]), ethionamide or prothionamide (aOR: 1.7 [1.4–2.1]), use of four or more likely effective drugs in the initial intensive phase (aOR: 2.7 [1.9–3.9]), and three or more likely effective drugs in the continuation phase (aOR: 4.5 [3.4–6.0]). Conclusions In this individual patient data meta-analysis of observational data, improved MDR-TB treatment success and survival were associated with use of certain fluoroquinolones, ethionamide, or prothionamide, and greater total number of effective drugs. However, randomized trials are urgently needed to optimize MDR-TB treatment. Please see later in the article for the Editors' Summary.

Journal ArticleDOI
TL;DR: In this paper, the authors defined credible sets of SNPs that were 95% likely, based on posterior probability, to contain the causal disease-associated SNPs, and showed the value of more detailed mapping to target sequences for functional studies.
Abstract: To further investigate susceptibility loci identified by genome-wide association studies, we genotyped 5,500 SNPs across 14 associated regions in 8,000 samples from a control group and 3 diseases: type 2 diabetes (T2D), coronary artery disease (CAD) and Graves' disease. We defined, using Bayes theorem, credible sets of SNPs that were 95% likely, based on posterior probability, to contain the causal disease-associated SNPs. In 3 of the 14 regions, TCF7L2 (T2D), CTLA4 (Graves' disease) and CDKN2A-CDKN2B (T2D), much of the posterior probability rested on a single SNP, and, in 4 other regions (CDKN2A-CDKN2B (CAD) and CDKAL1, FTO and HHEX (T2D)), the 95% sets were small, thereby excluding most SNPs as potentially causal. Very few SNPs in our credible sets had annotated functions, illustrating the limitations in understanding the mechanisms underlying susceptibility to common diseases. Our results also show the value of more detailed mapping to target sequences for functional studies.

Journal ArticleDOI
10 Sep 2012-PLOS ONE
TL;DR: In HIV-infected individuals, IL-6, hsCRP and D-dimer are associated with an increased risk of CVD independent of other CVD risk factors.
Abstract: Background: The SMART study was a trial of intermittent use of antiretroviral therapy (ART) (drug conservation [DC]) versus continuous use of ART (viral suppression [VS]) as a strategy to reduce toxicities, including cardiovascular disease (CVD) risk. We studied the predictive value of high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6) and D-dimer with CVD morbidity and mortality in HIV-infected patients who were enrolled in SMART beyond other measured CVD risk factors. Methods: A blood sample was available in 5098 participants who were enrolled in the SMART study for the measurement of IL-6, hsCRP and D-dimer. Hazard ratios (HR) with 95% CI for CVD events were estimated for each quartile (Q) for each biomarker vs the 1 st quartile and for 1 SD higher levels. For both treatment groups combined, unadjusted and adjusted HRs were determined using Cox regression models. Results: There were 252 participants who had a CVD event over a median follow-up of 29 months. Adjusted HRs (95% CI) for CVD for Q4 vs Q1 were 4.65 (2.61, 8.29), 2.10 (1.40, 3.16), and 2.14 (1.38, 3.33) for IL-6, hsCRP and D-dimer, respectively. Associations were similar for the DC and VS treatment groups (interaction p-values were .0.30). The addition of the three biomarkers to a model that included baseline covariates significantly improved model fit (p,0.001). Area under the curve (AUC) estimates improved with inclusion of the three biomarkers in a model that included baseline covariates corresponding to other CVD risk factors and HIV factors (0.741 to 0.771; p,0.001 for difference). Conclusions: In HIV-infected individuals, IL-6, hsCRP and D-dimer are associated with an increased risk of CVD independent of other CVD risk factors. Further research is needed to determine whether these biomarkers can be used to improve CVD risk prediction among HIV positive individuals.

Journal ArticleDOI
09 Aug 2012-Brain
TL;DR: It is demonstrated in a true population study that delirium is a strong risk factor for incident dementia and cognitive decline in the oldest-old and the relationship did not appear to be mediated by classical neuropathologies associated with dementia.
Abstract: Recent studies suggest that delirium is associated with risk of dementia and also acceleration of decline in existing dementia. However, previous studies may have been confounded by incomplete ascertainment of cognitive status at baseline. Herein, we used a true population sample to determine if delirium is a risk factor for incident dementia and cognitive decline. We also examined the effect of delirium at the pathological level by determining associations between dementia and neuropathological markers of dementia in patients with and without a history of delirium. The Vantaa 85+ study examined 553 individuals (92% of those eligible) aged ≥85 years at baseline, 3, 5, 8 and 10 years. Brain autopsy was performed in 52%. Fixed and random-effects regression models were used to assess associations between (i) delirium and incident dementia and (ii) decline in Mini-Mental State Examination scores in the whole group. The relationship between dementia and common neuropathological markers (Alzheimer-type, infarcts and Lewy-body) was modelled, stratified by history of delirium. Delirium increased the risk of incident dementia (odds ratio 8.7, 95% confidence interval 2.1-35). Delirium was also associated with worsening dementia severity (odds ratio 3.1, 95% confidence interval 1.5-6.3) as well as deterioration in global function score (odds ratio 2.8, 95% confidence interval 1.4-5.5). In the whole study population, delirium was associated with loss of 1.0 more Mini-Mental State Examination points per year (95% confidence interval 0.11-1.89) than those with no history of delirium. In individuals with dementia and no history of delirium (n = 232), all pathologies were significantly associated with dementia. However, in individuals with delirium and dementia (n = 58), no relationship between dementia and these markers was found. For example, higher Braak stage was associated with dementia when no history of delirium (odds ratio 2.0, 95% confidence interval 1.1-3.5, P = 0.02), but in those with a history of delirium, there was no significant relationship (odds ratio 1.2, 95% confidence interval 0.2-6.7, P = 0.85). This trend for odds ratios to be closer to unity in the delirium and dementia group was observed for neuritic amyloid, apolipoprotein e status, presence of infarcts, α-synucleinopathy and neuronal loss in substantia nigra. These findings are the first to demonstrate in a true population study that delirium is a strong risk factor for incident dementia and cognitive decline in the oldest-old. However, in this study, the relationship did not appear to be mediated by classical neuropathologies associated with dementia.

Journal ArticleDOI
25 May 2012-Cell
TL;DR: It is reported that RNase H2 is an essential enzyme in mice, required for embryonic growth from gastrulation onward, and it is demonstrated that ribonucleotides are the most commonly occurring endogenous nucleotide base lesion in replicating cells.

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TL;DR: The prerequisites for data commoning are described and an established and growing ecosystem of solutions using the shared 'Investigation-Study-Assay' framework to support that vision are presented.
Abstract: To make full use of research data, the bioscience community needs to adopt technologies and reward mechanisms that support interoperability and promote the growth of an open 'data commoning' culture. Here we describe the prerequisites for data commoning and present an established and growing ecosystem of solutions using the shared 'Investigation-Study-Assay' framework to support that vision.

Journal ArticleDOI
Jian Yang1, Jian Yang2, Ruth J. F. Loos3, Ruth J. F. Loos4  +195 moreInstitutions (63)
11 Oct 2012-Nature
TL;DR: The authors performed a meta-analysis of genome-wide association studies of phenotypic variation using ∼170,000 samples on height and body mass index (BMI) in human populations.
Abstract: There is evidence across several species for genetic control of phenotypic variation of complex traits, such that the variance among phenotypes is genotype dependent. Understanding genetic control of variability is important in evolutionary biology, agricultural selection programmes and human medicine, yet for complex traits, no individual genetic variants associated with variance, as opposed to the mean, have been identified. Here we perform a meta-analysis of genome-wide association studies of phenotypic variation using ∼170,000 samples on height and body mass index (BMI) in human populations. We report evidence that the single nucleotide polymorphism (SNP) rs7202116 at the FTO gene locus, which is known to be associated with obesity (as measured by mean BMI for each rs7202116 genotype), is also associated with phenotypic variability. We show that the results are not due to scale effects or other artefacts, and find no other experiment-wise significant evidence for effects on variability, either at loci other than FTO for BMI or at any locus for height. The difference in variance for BMI among individuals with opposite homozygous genotypes at the FTO locus is approximately 7%, corresponding to a difference of ∼0.5 kilograms in the standard deviation of weight. Our results indicate that genetic variants can be discovered that are associated with variability, and that between-person variability in obesity can partly be explained by the genotype at the FTO locus. The results are consistent with reported FTO by environment interactions for BMI, possibly mediated by DNA methylation. Our BMI results for other SNPs and our height results for all SNPs suggest that most genetic variants, including those that influence mean height or mean BMI, are not associated with phenotypic variance, or that their effects on variability are too small to detect even with samples sizes greater than 100,000.