2,487 research outputs found

    A Sox2–Sox9 signalling axis maintains human breast luminal progenitor and breast cancer stem cells

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    Increased cancer stem cell content during development of resistance to tamoxifen in breast cancer is driven by multiple signals, including Sox2-dependent activation of Wnt signalling. Here, we show that Sox2 increases and estrogen reduces the expression of the transcription factor Sox9. Gain and loss of function assays indicate that Sox9 is implicated in the maintenance of human breast luminal progenitor cells. CRISPR/Cas knockout of Sox9 reduces growth of tamoxifen-resistant breast tumours in vivo. Mechanistically, Sox9 acts downstream of Sox2 to control luminal progenitor cell content and is required for expression of the cancer stem cell marker ALDH1A3 and Wnt signalling activity. Sox9 is elevated in breast cancer patients after endocrine therapy failure. This new regulatory axis highlights the relevance of SOX family transcription factors as potential therapeutic targets in breast cancer

    An optical supernova associated with the X-ray flash XRF 060218

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    Long-duration gamma-ray bursts (GRBs) are associated with type Ic supernovae that are more luminous than average and that eject material at very high velocities. Less-luminous supernovae were not hitherto known to be associated with GRBs, and therefore GRB-supernovae were thought to be rare events. Whether X-ray flashes - analogues of GRBs, but with lower luminosities and fewer gamma-rays - can also be associated with supernovae, and whether they are intrinsically 'weak' events or typical GRBs viewed off the axis of the burst, is unclear. Here we report the optical discovery and follow-up observations of the type Ic supernova SN 2006aj associated with X-ray flash XRF 060218. Supernova 2006aj is intrinsically less luminous than the GRB-supernovae, but more luminous than many supernovae not accompanied by a GRB. The ejecta velocities derived from our spectra are intermediate between these two groups, which is consistent with the weakness of both the GRB output and the supernova radio flux. Our data, combined with radio and X-ray observations, suggest that XRF 060218 is an intrinsically weak and soft event, rather than a classical GRB observed off-axis. This extends the GRB-supernova connection to X-ray flashes and fainter supernovae, implying a common origin. Events such as XRF 060218 are probably more numerous than GRB-supernovae.Comment: Final published versio

    Hepatitis B Sero-Prevalence and Risk Behaviors Among Immigrant Men in a Population-Based Household Survey in Low-Income Neighborhoods of Northern California

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    Background Despite an effective vaccine, 60,000 new HBV infections were reported in the US in 2004; 95% in adults. We evaluate HBV sero-prevalence, risk behaviors and self-reported vaccination among Latino immigrant, Asian immigrant and US born low income men in five northern California counties. Methods Population based, cross sectional survey of HBV sero-prevalence and risk behaviors in men aged 18 to 35 years. Results Among 1,512 men screened, Asian immigrants were most likely to have had prior HBV infection (15.1%) and chronic infection (3.8%) compared to US born (prior 5.1%, chronic 0.6%) and Latino immigrant men (prior 2.0%, chronic 0.3%.) Reported HBV vaccination was lowest for Latino immigrants (12%) compared to Asian immigrants and US born men (35% in both.) Latino immigrants reported less educational attainment, medical insurance coverage and access to a physician in the last six months. Discussion Healthcare providers should routinely screen Asian immigrants for HBV regardless of their self reported vaccination status. Latino immigrants may comprise an important group of under-vaccinated, at risk persons in California. HBV testing and vaccination of immigrants soon after US arrival should be encouraged

    Role of mitochondrial raft-like microdomains in the regulation of cell apoptosis

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    Lipid rafts are envisaged as lateral assemblies of specific lipids and proteins that dissociate and associate rapidly and form functional clusters in cell membranes. These structural platforms are not confined to the plasma membrane; indeed lipid microdomains are similarly formed at subcellular organelles, which include endoplasmic reticulum, Golgi and mitochondria, named raft-like microdomains. In addition, some components of raft-like microdomains are present within ER-mitochondria associated membranes. This review is focused on the role of mitochondrial raft-like microdomains in the regulation of cell apoptosis, since these microdomains may represent preferential sites where key reactions take place, regulating mitochondria hyperpolarization, fission-associated changes, megapore formation and release of apoptogenic factors. These structural platforms appear to modulate cytoplasmic pathways switching cell fate towards cell survival or death. Main insights on this issue derive from some pathological conditions in which alterations of microdomains structure or function can lead to severe alterations of cell activity and life span. In the light of the role played by raft-like microdomains to integrate apoptotic signals and in regulating mitochondrial dynamics, it is conceivable that these membrane structures may play a role in the mitochondrial alterations observed in some of the most common human neurodegenerative diseases, such as Amyotrophic lateral sclerosis, Huntington's chorea and prion-related diseases. These findings introduce an additional task for identifying new molecular target(s) of pharmacological agents in these pathologies

    Expression of EBV Encoded viral RNA 1, 2 and anti-inflammatory Cytokine (interleukin-10) in FFPE lymphoma specimens: a preliminary study for diagnostic implication in Pakistan

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    <p>Abstract</p> <p>Background</p> <p>Epstein Barr Virus (EBV) plays a significant role as a cofactor in the process of tumorigenesis and has consistently been associated with a variety of malignancies. EBV encoded RNAs (EBER1 and EBER2) are the most abundant viral transcripts in latently EBV-infected cells and their role in viral infection is still unclear. Formalin Fixed Paraffin Embedded (FFPE) tissues of surgically removed carcinoma biopsies are widely available form but have never been exploited for expressional studies previously in Pakistan. Immunohistochemistry (IHC) and <it>in situ </it>hybridization (ISH) in FFPE biopsy tissues remains the gold standard for proving EBV relationship in a histopathological lesion but their reagents associated limitations confines their reliability in some applications. Recently introduced targeted drug delivery systems induce viral lytic gene expression and therefore require more sensitive method to quantify viral as well as cellular gene expression.</p> <p>Methods</p> <p>Eight (8) lymphoma samples were screened to detect the EBV genome. Qualitative and quantitative expression of EBV Encoded RNAs (EBER1, EBER2) and anti-inflammatory cytokine (interleukin-10) in FFPE EBV positive lymphoma tissue samples were then analysed by using Reverse transcriptase Polymerase Chain Reaction (RT-PCR) and Real Time Polymerase Chain Reaction (qRT-PCR), respectively.</p> <p>Results</p> <p>In this study we have successfully quantified elevated expressional levels of both cellular and viral transcripts, namely EBER1, EBER2 and anti-inflammatory cytokine (IL-10) in the FFPE Burkitt's lymphoma (BL) specimens of Pakistani origin.</p> <p>Conclusions</p> <p>These results indicate that FFPE samples may retain viral as well as cellular RNA expression information at detectable level. To our knowledge, this is first study which represents elevated expressional levels of EBER1, EBER2 and IL-10 in FFPE tissue samples of Burkitt's lymphoma in Pakistan. These observations will potentially improve current lacunas in clinical as well as diagnostic practices in Pakistan and can be further exploited to develop new strategies for studying cellular and/or viral gene expression.</p

    Gaps in beliefs and practice in dyslipidaemia management in Japan, Germany, Colombia and the Philippines : insights from a web-based physician survey

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    Q3Q1Artículo completo1-9Background: Implementing evidence-based management of dyslipidaemia is a challenge worldwide. Objectives: To understand physician beliefs and behaviour and identify uncertainties in dyslipidaemia management across four world regions. Methods: Web-based survey of 1758 physicians in Japan, Germany, Colombia and the Philippines who were selected randomly from existing databases. Key inclusion criteria were 1) for cardiologists and diabetes/ endocrinology specialists: ≥50 dyslipidaemia patients examined in the last month; 2) for specialists in neurology/ neurosurgery/stroke medicine: ≥50 dyslipidaemia patients and ≥ 20 patients with a history of ischaemic stroke examined in the last month; and 3) for specialists in nephrology and general medicine: based at centres with ≥20 beds and ≥ 50 dyslipidaemia patients examined in the last month. The self-report survey covered dyslipidaemia management, target low-density lipoprotein cholesterol (LDL-C) levels in different patient groups, and statin safety. All physicians gave voluntary consent and all data were anonymised. Analysis was solely descriptive. Results: The survey highlighted key areas of uncertainty in dyslipidaemia management in the four countries. These related to LDL-C targets in different patient groups, the safety of low LDL-C levels, the safety of statins, especially for effects on cognitive, renal and hepatic function and for haemorrhagic stroke risk, and lipid management strategies in patients with chronic kidney disease, including those with concomitant hypertriglyceridaemia. Conclusions: This survey of physicians in Japan, Germany, Colombia and the Philippines has identified key gaps in knowledge about dyslipidaemia management. These relate to the safety of low LDL-C levels, the safety of statins, and lipid management of chronic kidney disease. The findings from this survey highlight the need for further education to improve the implementation of guideline recommendations for dyslipidaemia managemen

    Bcl-2 protein family: Implications in vascular apoptosis and atherosclerosis

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    Apoptosis has been recognized as a central component in the pathogenesis of atherosclerosis, in addition to the other human pathologies such as cancer and diabetes. The pathophysiology of atherosclerosis is complex, involving both apoptosis and proliferation at different phases of its progression. Oxidative modification of lipids and inflammation differentially regulate the apoptotic and proliferative responses of vascular cells during progression of the atherosclerotic lesion. Bcl-2 proteins act as the major regulators of extrinsic and intrinsic apoptosis signalling pathways and more recently it has become evident that they mediate the apoptotic response of vascular cells in response to oxidation and inflammation either in a provocative or an inhibitory mode of action. Here we address Bcl-2 proteins as major therapeutic targets for the treatment of atherosclerosis and underscore the need for the novel preventive and therapeutic interventions against atherosclerosis, which should be designed in the light of molecular mechanisms regulating apoptosis of vascular cells in atherosclerotic lesions

    The Eurolight project: the impact of primary headache disorders in Europe. Description of methods

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    The Eurolight project is the first at European Union level to assess the impact of headache disorders, and also the first of its scale performed by collaboration between professional and lay organizations and individuals. Here are reported the methods developed for it. The project took the form of surveys, by structured questionnaire, conducted in ten countries of Europe which together represented 60% of the adult population of the European Union. In Lithuania, the survey was population-based. Elsewhere, truly population-based studies were impractical for reasons of cost, and various compromises were developed. Closest to being population-based were the surveys in Germany, Luxembourg, the Netherlands, Italy and Spain. In Austria, France and UK, samples were taken from health-care settings. In addition in the Netherlands, Spain and Ireland, samples were drawn from members of national headache patient organizations and their relatives. Independent double data-entry was performed prior to analysis. Returned questionnaires from 9,269 respondents showed a moderate female bias (58%); of respondents from patients’ organizations (n = 992), 61% were female. Mean age of all respondents was 44 years; samples from patients’ organizations were slightly older (mean 47 years). The different sampling methods worked with differing degrees of effectiveness, as evidenced by the responder-rates, which varied from 10.8 to 90.7%. In the more population-based surveys, responder-rates varied from 11.3 to 58.8%. We conclude that the methodology, although with differences born of necessity in the ten countries, was sound overall, and will provide robust data on the public ill-health that results from headache in Europe

    Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron

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    We study the underlying event in proton-antiproton collisions by examining the behavior of charged particles (transverse momentum pT > 0.5 GeV/c, pseudorapidity |\eta| < 1) produced in association with large transverse momentum jets (~2.2 fb-1) or with Drell-Yan lepton-pairs (~2.7 fb-1) in the Z-boson mass region (70 < M(pair) < 110 GeV/c2) as measured by CDF at 1.96 TeV center-of-mass energy. We use the direction of the lepton-pair (in Drell-Yan production) or the leading jet (in high-pT jet production) in each event to define three regions of \eta-\phi space; toward, away, and transverse, where \phi is the azimuthal scattering angle. For Drell-Yan production (excluding the leptons) both the toward and transverse regions are very sensitive to the underlying event. In high-pT jet production the transverse region is very sensitive to the underlying event and is separated into a MAX and MIN transverse region, which helps separate the hard component (initial and final-state radiation) from the beam-beam remnant and multiple parton interaction components of the scattering. The data are corrected to the particle level to remove detector effects and are then compared with several QCD Monte-Carlo models. The goal of this analysis is to provide data that can be used to test and improve the QCD Monte-Carlo models of the underlying event that are used to simulate hadron-hadron collisions.Comment: Submitted to Phys.Rev.
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