665 research outputs found

    Mechanistic interrogation of combination Bevacizumab/dual PI3K/mTOR inhibitor response in Glioblastoma implementing novel MR and PET imaging biomarkers.

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    Purpose: Resistance to bevacizumab (BEV) in glioblastoma (GBM) is believed to occur via activation of molecular networks including the mTOR/PI3K pathway. Implementing an MRI/PET molecular imaging biomarker approach, we sought to interrogate response to combining BEV with the mTOR/PI3K inhibitor BEZ235. Methods: Tumors were established by orthotopically implanting U87MG-luc2 in mice. Animals were treated with BEZ235 and/or BEV, and imaged using diffusion weighted-MRI, T2 weighted (T2w), and T2* weighted (T2*w) before and following delivery of superparamagnetic iron oxide (SPIO) contrast. Maps for changes in relaxation rates: ΔR2, ΔR2* and apparent diffusion coefficient (ADC) were calculated. Vessel Size Index (VSI) and micro vessel density index (MDI) were derived. 3´-deoxy-3´-[18F]fluorothymidine ([18F]FLT)- and O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET) PET was further performed and tumor endothelium/proliferation markers assessed by immunohistochemistry. Results: Treatment with BEV resulted in a pronounced decrease in tumor volume (T2w MRI). No additive effect on tumour volume was observed in BEV/BEZ235 combination compared with BEV monotherapy. Ki67 proliferation index staining and [18F]FLT uptake studies were used to support observations. Using ΔR2* and ΔR2 values respectively, BEZ235 + BEV combination significantly reduced tumor microvessel volume in comparison to BEV alone. Decreased MDI was further observed in the combination group; supported by von Willebrand Factor (vWF) immunohistochemistry. We observed decreased [18F]FET uptake following BEV, but failed to observe further reduced [18F]FET uptake in the combination cohort. vWF IHC analysis showed mean tumor vessel size increased in all cohorts. Conclusions: Assessing MR imaging biomarker parameters together with [18F]FET and [18F]FLT PET, informed drug combination mechanism of action and provided clues as to potential clinical response. Translation of a BEZ35/BEV combination regimen could support reduction of peritumoral edemaobviating the requirement for steroids. Implementing hypothesis driven molecular imaging studies facilitates the interrogation of drug response in the pre-clinic. These data may more accurately predict the clinical potential of novel therapeutic approaches in oncology

    Tbx3 fosters pancreatic cancer growth by increased angiogenesis and activin/nodal-dependent induction of stemness

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    AbstractCell fate decisions and pluripotency, but also malignancy depend on networks of key transcriptional regulators. The T-box transcription factor TBX3 has been implicated in the regulation of embryonic stem cell self-renewal and cardiogenesis. We have recently discovered that forced TBX3 expression in embryonic stem cells promotes mesendoderm specification directly by activating key lineage specification factors and indirectly by enhancing paracrine NODAL signalling. Interestingly, aberrant TBX3 expression is associated with breast cancer and melanoma formation. In other cancers, loss of TBX3 expression is associated with a more aggressive phenotype e.g. in gastric and cervical cancer. The precise function of TBX3 in pancreatic ductal adenocarcinoma remains to be determined. In the current study we provide conclusive evidence for TBX3 overexpression in pancreatic cancer samples as compared to healthy tissue. While proliferation remains unaltered, forced TBX3 expression strongly increases migration and invasion, but also angiogenesis in vitro and in vivo. Finally, we describe the TBX3-dependency of cancer stem cells that perpetuate themselves through an autocrine TBX3–ACTIVIN/NODAL signalling loop to sustain stemness. Thus, TBX3 is a new key player among pluripotency-related genes driving cancer formation

    Human pluripotent stem cell-derived acinar/ductal organoids generate human pancreas upon orthotopic transplantation and allow disease modelling

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    Objective The generation of acinar and ductal cells from human pluripotent stem cells (PSCs) is a poorly studied process, although various diseases arise from this compartment. Design We designed a straightforward approach to direct human PSCs towards pancreatic organoids resembling acinar and ductal progeny. Results Extensive phenotyping of the organoids not only shows the appropriate marker profile but also ultrastructural, global gene expression and functional hallmarks of the human pancreas in the dish. Upon orthotopic transplantation into immunodeficient mice, these organoids form normal pancreatic ducts and acinar tissue resembling fetal human pancreas without evidence of tumour formation or transformation. Finally, we implemented this unique phenotyping tool as a model to study the pancreatic facets of cystic fibrosis (CF). For the first time, we provide evidence that in vitro, but also in our xenograft transplantation assay, pancreatic commitment occurs generally unhindered in CF. Importantly, cystic fibrosis transmembrane conductance regulator (CFTR) activation in mutated pancreatic organoids not only mirrors the CF phenotype in functional assays but also at a global expression level. We also conducted a scalable proof-of-concept screen in CF pancreatic organoids using a set of CFTR correctors and activators, and established an mRNA-mediated gene therapy approach in CF organoids. Conclusions Taken together, our platform provides novel opportunities to model pancreatic disease and development, screen for disease-rescuing agents and to test therapeutic procedures.This study was funded by the Deutsche Forschungsgemeinschaft (DFG, K.L. 2544/1-1 and 1-2), the Forschungskern SyStaR to AK, BIU (Böhringer Ingelheim Ulm to AK), the Fritz-Thyssen Foundation (Az. 10.15.2.040), the German Cancer Aid (111879) and the Else-Kröner-Fresenius-Stiftung (2011_A200). AK is indebted to the Baden-Württemberg Stiftung for the financial support of this research project by the Eliteprogramme for Postdocs. AK is also an Else-Kröner-Fresenius Memorial Fellow. LP is supported by a research fellowship of the Else-Kröner-Fresenius-Stiftung. MH was supported by the International Graduate School in Molecular Medicine and the Bausteinprogramme (L.SBN. 110), Ulm University. MM is supported by a grant of Ulm University (Baustein for Senior Clinician Scientists). IGC is funded by the Interdisciplinary Center for Clinical Research (IZKF Aachen) and Start Program, RWTH Aachen University Medical School, Aachen, German

    Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

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    Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition

    How to address smart homes with a social robot? A multi-modal corpus of user interactions with an intelligent environment

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    Holthaus P, Leichsenring C, Bernotat J, et al. How to address smart homes with a social robot? A multi-modal corpus of user interactions with an intelligent environment. In: Calzolari N, ed. LREC 2016, Tenth International Conference on Language Resources and Evaluation. [Proceedings]. Paris: European Language Resources Association (ELRA); 2016: 3440-3446.In order to explore intuitive verbal and non-verbal interfaces in smart environments we recorded user interactions with an intelligent apartment. Besides offering various interactive capabilities itself, the apartment is also inhabited by a social robot that is available as a humanoid interface. This paper presents a multi-modal corpus that contains goal-directed actions of naive users in attempts to solve a number of predefined tasks. Alongside audio and video recordings, our data-set consists of large amount of temporally aligned sensory data and system behavior provided by the environment and its interactive components. Non-verbal system responses such as changes in light or display contents, as well as robot and apartment utterances and gestures serve as a rich basis for later in-depth analysis. Manual annotations provide further information about meta data like the current course of study and user behavior including the incorporated modality, all literal utterances, language features, emotional expressions, foci of attention, and addressees

    Welcome to the future – How naïve users intuitively address an intelligent robotics apartment.

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    Bernotat J, Schiffhauer B, Eyssel FA, et al. Welcome to the future – How naïve users intuitively address an intelligent robotics apartment. In: Agah A, Cabibihan JJ, Howard AM, Salichs MA, He H, eds. Lecture Notes in Artificial Intelligence (LNAI). Vol 9979. Heidelberg/ Berlin: Springer; 2016: 982-992

    Plasma extracellular vesicle tau and TDP-43 as diagnostic biomarkers in FTD and ALS

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    Minimally invasive biomarkers are urgently needed to detect molecular pathology in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Here, we show that plasma extracellular vesicles (EVs) contain quantifiable amounts of TDP-43 and full-length tau, which allow the quantification of 3-repeat (3R) and 4-repeat (4R) tau isoforms. Plasma EV TDP-43 levels and EV 3R/4R tau ratios were determined in a cohort of 704 patients, including 37 genetically and 31 neuropathologically proven cases. Diagnostic groups comprised patients with TDP-43 proteinopathy ALS, 4R tauopathy progressive supranuclear palsy, behavior variant FTD (bvFTD) as a group with either tau or TDP-43 pathology, and healthy controls. EV tau ratios were low in progressive supranuclear palsy and high in bvFTD with tau pathology. EV TDP-43 levels were high in ALS and in bvFTD with TDP-43 pathology. Both markers discriminated between the diagnostic groups with area under the curve values &gt;0.9, and between TDP-43 and tau pathology in bvFTD. Both markers strongly correlated with neurodegeneration, and clinical and neuropsychological markers of disease severity. Findings were replicated in an independent validation cohort of 292 patients including 34 genetically confirmed cases. Taken together, the combination of EV TDP-43 levels and EV 3R/4R tau ratios may aid the molecular diagnosis of FTD, FTD spectrum disorders and ALS, providing a potential biomarker to monitor disease progression and target engagement in clinical trials.</p

    Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015

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    Background The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defi ned criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specifi c DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI).Background The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defi ned criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specifi c DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI)

    Label-free protein detection based on the heat-transfer method-a case study with the peanut allergen Ara h 1 and aptamer-based synthetic receptors

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    © 2015 American Chemical Society. Aptamers are an emerging class of molecules that, because of the development of the systematic evolution of ligands by exponential enrichment (SELEX) process, can recognize virtually every target ranging from ions, to proteins, and even whole cells. Although there are many techniques capable of detecting template molecules with aptamer-based systems with high specificity and selectivity, they lack the possibility of integrating them into a compact and portable biosensor setup. Therefore, we will present the heat-transfer method (HTM) as an interesting alternative because this offers detection in a fast and low-cost manner and has the possibility of performing experiments with a fully integrated device. This concept has been demonstrated for a variety of applications including DNA mutation analysis and screening of cancer cells. To the best our knowledge, this is the first report on HTM-based detection of proteins, in this case specifically with aptamer-type receptors. For proof-of-principle purposes, measurements will be performed with the peanut allergen Ara h 1 and results indicate detection limits in the lower nanomolar regime in buffer liquid. As a first proof-of-application, spiked Ara h 1 solutions will be studied in a food matrix of dissolved peanut butter. Reference experiments with the quartz-crystal microbalance will allow for an estimate of the areal density of aptamer molecules on the sensor-chip surface

    CMS physics technical design report : Addendum on high density QCD with heavy ions

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