331 research outputs found

    Outcomes of left split graft transplantation in Europe: report from the European Liver Transplant Registry

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    Split liver transplantation (SLT) has been widely adopted across Europe, resulting in remarkable reduction in the paediatric waiting-list mortality. Left split graft (LSG) is commonly used for paediatric recipients; however, deceased donor criteria selection are not universal. The aim of this study was to analyse the LSG outcome from the European Liver Transplant Registry and to identify risk factors for graft failure. Data from 1500 children transplanted in 2006-2014 with LSG from deceased donors were retrospectively analysed. Overall, graft losses were 343(22.9%) after 5 years from transplantation, 240(70.0%) occurred within the first 3 months. Estimated patient survival was 89.1% at 3 months and 82.9% at 5 years from SLT. Re-transplantation rate was 11.5%. At multivariable analysis, significant risk factors for graft failure at 3 months included the following: urgent SLT (HR = 1.73, P = 0.0012), recipient body weight ≤6 kg (HR = 1.91, P = 0.0029), donor age >50 years (HR = 1.87, P = 0.0039), and cold ischaemic time (CIT) [HR = 1.07 per hour, P = 0.0227]. LSG has good outcomes and SLT is excellent option for paediatric recipients in the current organ shortage era. We identified practical guidelines for LSG donor and recipient selection criteria: donor age may be safely extended up to 50 years in the absence of additional risk factors; thus, children <6 kg and urgent transplantation need CIT <6 h and appropriate graft/recipient size-matching to achieve good outcomes

    Small poly-L-lysines improve cationic lipid-mediated gene transfer in vascular cells in vitro and in vivo

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    The potential of two small poly-L-lysines ( sPLLs), low molecular weight sPLL ( LMW-L) containing 7 - 30 lysine residues and L18 with 18 lysine repeats, to enhance the efficiency of liposome-mediated gene transfer ( GT) with cationic lipid DOCSPER {[}1,3- dioleoyloxy- 2-( N-5-carbamoyl-spermine)-propane] in vascular smooth muscle cells ( SMCs) was investigated. Dynamic light scattering was used for determination of particle size. Confocal microscopy was applied for colocalization studies of sPLLs and plasmid DNA inside cells. GT was performed in proliferating and quiescent primary porcine SMCs in vitro and in vivo in porcine femoral arteries. At low ionic strength, sPLLs formed small complexes with DNA ( 50 100 nm). At high ionic strength, large complexes ( 11 mu m) were observed without any significant differences in particle size between lipoplexes ( DOCSPER/ DNA) and lipopolyplexes ( DOCSPER/ sPLL/ DNA). Both sPLLs were colocalized with DNA inside cells 24 h after transfection, protecting DNA against degradation. DOCSPER/ sPLL/ DNA formulations enhanced GT in vitro up to 5- fold, in a porcine model using local periadventitial application up to 1.5- fold. Both sPLLs significantly increased liposome- mediated GT. Poly-L-lysine L18 was superior to LMW-L since it enabled maximal GT at a 10-fold lower concentration. Thus, sPLLs may serve as enhancers for GT applications in SMCs in vitro and in vivo using local delivery. Copyright (c) 2007 S. Karger AG, Basel

    Emergent Schr\"{o}dinger cat states during superradiant phase transitions

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    Superradiant phase transitions (SPTs) are important for understanding light-matter interactions at the quantum level [1, 2], and play a central role in criticality-enhanced quantum sensing [3]. So far, SPTs have been observed in driven-dissipative systems [4-9], but the emergent light fields did not show any nonclassical characteristic due to the presence of strong dissipation. Here we report an experimental demonstration of the SPT featuring the emergence of a highly nonclassical photonic field, realized with a resonator coupled to a superconducting qubit, implementing the quantum Rabi model [10, 11]. We fully characterize the light-matter state by Wigner matrix tomography. The measured matrix elements exhibit quantum interference intrinsic of a photonic Schr\"{o}dinger cat state [12], and reveal light-matter entanglement. Besides their fundamental importance, these hitherto unobserved emergent quantum phenomena are useful for quantum metrology and fault-tolerant quantum computation.Comment: 19 pages, 14 figures, 2 table

    WNT signaling regulates self-renewal and differentiation of prostate cancer cells with stem cell characteristics

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    Prostate cancer cells with stem cell characteristics were identified in human prostate cancer cell lines by their ability to form from single cells self-renewing prostaspheres in non-adherent cultures. Prostaspheres exhibited heterogeneous expression of proliferation, differentiation and stem cell-associated makers CD44, ABCG2 and CD133. Treatment with WNT inhibitors reduced both prostasphere size and self-renewal. In contrast, addition of Wnt3a caused increased prostasphere size and self-renewal, which was associated with a significant increase in nuclear Β-catenin, keratin 18, CD133 and CD44 expression. As a high proportion of LNCaP and C4-2B cancer cells express androgen receptor we determined the effect of the androgen receptor antagonist bicalutamide. Androgen receptor inhibition reduced prostasphere size and expression of PSA, but did not inhibit prostasphere formation. These effects are consistent with the androgen-independent self-renewal of cells with stem cell characteristics and the androgen-dependent proliferation of transit amplifying cells. As the canonical WNT signaling effector Β-catenin can also associate with the androgen receptor, we propose a model for tumour propagation involving a balance between WNT and androgen receptor activity. That would affect the self-renewal of a cancer cell with stem cell characteristics and drive transit amplifying cell proliferation and differentiation. In conclusion, we provide evidence that WNT activity regulates the self-renewal of prostate cancer cells with stem cell characteristics independently of androgen receptor activity. Inhibition of WNT signaling therefore has the potential to reduce the self-renewal of prostate cancer cells with stem cell characteristics and improve the therapeutic outcome.Peer reviewe

    MicroRNAs targeting oncogenes are down-regulated in pancreatic malignant transformation from benign tumors

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    BACKGROUND MicroRNA (miRNA) expression profiles have been described in pancreatic ductal adenocarcinoma (PDAC), but these have not been compared with pre-malignant pancreatic tumors. We wished to compare the miRNA expression signatures in pancreatic benign cystic tumors (BCT) of low and high malignant potential with PDAC, in order to identify miRNAs deregulated during PDAC development. The mechanistic consequences of miRNA dysregulation were further evaluated. METHODS Tissue samples were obtained at a tertiary pancreatic unit from individuals with BCT and PDAC. MiRNA profiling was performed using a custom microarray and results were validated using RT-qPCR prior to evaluation of miRNA targets. RESULTS Widespread miRNA down-regulation was observed in PDAC compared to low malignant potential BCT. We show that amongst those miRNAs down-regulated, miR-16, miR-126 and let-7d regulate known PDAC oncogenes (targeting BCL2, CRK and KRAS respectively). Notably, miR-126 also directly targets the KRAS transcript at a "seedless" binding site within its 3'UTR. In clinical specimens, miR-126 was strongly down-regulated in PDAC tissues, with an associated elevation in KRAS and CRK proteins. Furthermore, miR-21, a known oncogenic miRNA in pancreatic and other cancers, was not elevated in PDAC compared to serous microcystic adenoma (SMCA), but in both groups it was up-regulated compared to normal pancreas, implicating early up-regulation during malignant change. CONCLUSIONS Expression profiling revealed 21 miRNAs down-regulated in PDAC compared to SMCA, the most benign lesion that rarely progresses to invasive carcinoma. It appears that miR-21 up-regulation is an early event in the transformation from normal pancreatic tissue. MiRNA expression has the potential to distinguish PDAC from normal pancreas and BCT. Mechanistically the down-regulation of miR-16, miR-126 and let-7d promotes PDAC transformation by post-transcriptional up-regulation of crucial PDAC oncogenes. We show that miR-126 is able to directly target KRAS; re-expression has the potential as a therapeutic strategy against PDAC and other KRAS-driven cancers

    Health system strengthening—Reflections on its meaning, assessment, and our state of knowledge

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    Sophie Witter - ORCID 0000-0002-7656-6188 https://orcid.org/0000-0002-7656-6188Comprehensive reviews of health system strengthening (HSS) interventions are rare, partly because of lack of clarity on definitions of the term but also the potentially huge scale of the evidence. We reflect on the process of undertaking such an evidence review recently, drawing out suggestions on definitions of HSS and approaches to assessment, as well as summarising some key conclusions from the current evidence base. The key elements of a clear definition include, in our view, consideration of scope (with effects cutting across building blocks in practice, even if not in intervention design, and also tackling more than one disease), scale (having national reach and cutting across levels of the system), sustainability (effects being sustained over time and addressing systemic blockages), and effects (impacting on health outcomes, equity, financial risk protection, and responsiveness). We also argue that agreeing a framework for design and evaluation of HSS is urgent. Most HSS interventions have theories of change relating to specific system blocks, but more work is needed on capturing their spillover effects and their contribution to meeting overarching health system process goals. We make some initial suggestions about such goals, to reflect the features that characterise a “strong health system.” We highlight that current findings on “what works” are just indicative, given the limitations and biases in what has been studied and how, and argue that there is need to rethink evaluation methods for HSS beyond finite interventions and narrow outcomes. Clearer concepts, frameworks, and methods can support more coherent HSS investment.Department for International Development, Grant/Award Number: Supported by the ReBUILD and ReSYST RPCshttps://doi.org/10.1002/hpm.288234pubpub

    In Caenorhabditis elegans Nanoparticle-Bio-Interactions Become Transparent: Silica-Nanoparticles Induce Reproductive Senescence

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    While expectations and applications of nanotechnologies grow exponentially, little is known about interactions of engineered nanoparticles with multicellular organisms. Here we propose the transparent roundworm Caenorhabditis elegans as a simple but anatomically and biologically well defined animal model that allows for whole organism analyses of nanoparticle-bio-interactions. Microscopic techniques showed that fluorescently labelled nanoparticles are efficiently taken up by the worms during feeding, and translocate to primary organs such as epithelial cells of the intestine, as well as secondary organs belonging to the reproductive tract. The life span of nanoparticle-fed Caenorhabditis elegans remained unchanged, whereas a reduction of progeny production was observed in silica-nanoparticle exposed worms versus untreated controls. This reduction was accompanied by a significant increase of the ‘bag of worms’ phenotype that is characterized by failed egg-laying and usually occurs in aged wild type worms. Experimental exclusion of developmental defects suggests that silica-nanoparticles induce an age-related degeneration of reproductive organs, and thus set a research platform for both, detailed elucidation of molecular mechanisms and high throughput screening of different nanomaterials by analyses of progeny production
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