265 research outputs found

    Brane-world Kaluza-Klein reductions and Branes on the Brane

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    We present a systematic study of a new type of consistent ``Brane-world Kaluza-Klein Reduction,'' which describe fully non-linear deformations of co-dimension one objects that arise as solutions of a large class of gauged supergravity theories in diverse dimensions, and whose world-volume theories are described by ungauged supergravities with one half of the original supersymmetry. In addition, we provide oxidations of these Ansatze which are in general related to sphere compactified higher dimensional string theory or M-theory. Within each class we also provide explicit solutions of brane configurations localised on the world-brane. We show that at the Cauchy horizon (in the transverse dimension of the consistently Kaluza-Klein reduced world-brane) there is a curvature singularity for any configuration with a non-null Riemann curvature or a non-vanishing Ricci scalar that lives in the world-brane. Since the massive Kaluza-Klein modes can be consistently decoupled, they cannot participate in regulating these singularities.Comment: latex, 30 page

    Healthcare resource utilization and medical costs for children with interstitial lung diseases (chILD) in Europe

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    Background No data on healthcare utilisation and associated costs for the many rare entities of children's interstitial lung diseases (chILD) exist. This paper portrays healthcare utilisation structures among individuals with chILD, provides a pan-European estimate of a 3-month interval per-capita costs and delineates crucial cost drivers. Methods Based on longitudinal healthcare resource utilisation pattern of 445 children included in the Kids Lung Register diagnosed with chILD across 10 European countries, we delineated direct medical and non-medical costs of care per 3-month interval. Country-specific utilisation patterns were assessed with a children-tailored modification of the validated FIMA questionnaire and valued by German unit costs. Costs of care and their drivers were subsequently identified via gamma-distributed generalised linear regression models. Results During the 3 months prior to inclusion into the registry (baseline), the rate of hospital admissions and inpatient days was high. Unadjusted direct medical per capita costs (euro19 818) exceeded indirect (euro1 907) and direct non-medical costs (euro1 125) by far. Country-specific total costs ranged from euro8 713 in Italy to euro28 788 in Poland. Highest expenses were caused by the disease categories 'diffuse parenchymal lung disease (DPLD)-diffuse developmental disorders' (euro45 536) and 'DPLD-unclear in the non-neonate' (euro47 011). During a follow-up time of up to 5 years, direct medical costs dropped, whereas indirect costs and non-medical costs remained stable. Conclusions This is the first prospective, longitudinal study analysing healthcare resource utilisation and costs for chILD across different European countries. Our results indicate that chILD is associated with high utilisation of healthcare services, placing a substantial economic burden on health systems

    A Novel Porcine In Vitro Model of the Blood-Cerebrospinal Fluid Barrier with Strong Barrier Function

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    Epithelial cells of the plexus choroideus form the structural basis of the blood-cerebrospinal fluid barrier (BCSFB). In vitro models of the BCSFB presenting characteristics of a functional barrier are of significant scientific interest as tools for examination of BCSFB function. Due to a lack of suitable cell lines as in vitro models, primary porcine plexus epithelial cells were subjected to a series of selective cultivation steps until a stable continuous subcultivatable epithelial cell line (PCP-R) was established. PCP-R cells grow in a regular polygonal pattern with a doubling time of 28–36 h. At a cell number of 1.5×105 in a 24-well plate confluence is reached in 56–72 h. Cells are cytokeratin positive and chromosomal analysis revealed 56 chromosomes at peak (84th subculture). Employing reverse transcription PCR mRNA expression of several transporters and components of cell junctions could be detected. The latter includes tight junction components like Claudin-1 and -3, ZO-1, and Occludin, and the adherens junction protein E-cadherin. Cellular localization studies of ZO-1, Occludin and Claudin-1 by immunofluorescence and morphological analysis by electron microscopy demonstrated formation of a dense tight junction structure. Importantly, when grown on cell culture inserts PCP-R developed typical characteristics of a functional BCSFB including high transepithelial electrical resistance above 600 Ω×cm2 as well as low permeability for macromolecules. In summary, our data suggest the PCP-R cell line as a suitable in vitro model of the porcine BCSFB

    Role of image-guided fine-needle aspiration biopsy in the management of patients with splenic metastasis

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    BACKGROUND: Splenic metastases are very rare and are mostly diagnosed at the terminal phase of the disease or at the time of autopsy. The cytohistological diagnosis, when done, is made prevalently by splenectomy. Reports on splenic percutaneous biopsies in the diagnosis of splenic metastasis are fragmentary and very poor. The aims of this study are to analyse retrospectively the accuracy, safety and the clinical impact of ultrasound (US)-guided fine-needle aspiration biopsy (UG-FNAB) in patients with suspected splenic metastasis. METHODS: A retrospective analysis of 1800 percutaneous abdominal biopsies performed at our institute during the period from 1993 to 2003 was done and 160 patients that underwent splenic biopsy were found. Among these 160 patients, 12 cases with the final diagnosis of solitary splenic metastases were encountered and they form the basis of this report. The biopsies were performed under US guidance using a 22-gauge Chiba needle. All the patients underwent laboratory tests, CT examination of the abdomen and chest, US examination of abdomen and pelvis. RESULTS: There were 5 women and 7 men, median age 65 years (range 48–80). Eight patients had a known primary cancer at the time of the diagnosis of splenic metastasis: 3 had breast adenocarcinoma, 2 colon adenocarcinoma, 2 melanoma and 1 lung adenocarcinoma. Four patients were undiagnosed at the time of the appearance of splenic metastasis and subsequent investigations showed adenocarcinoma of the lung in 2 patients and colon adenocarcinoma in the remaining 2. There was a complete correspondence between the US and Computed Tomography (CT) in detecting focal lesions of the spleen. The splenic biopsies allowed a cytological diagnosis of splenic metastasis in all the 12 patients and changed clinical management in all cases. Reviewing the 160 patients that underwent UG-FNAB of the spleen we found no complications related to the biopsies. CONCLUSION: These results indicate that UG-FNAB is a successful technique for diagnosis of splenic metastasis allowing an adequate treatment of the affected patients

    Differential splicing using whole-transcript microarrays

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    <p>Abstract</p> <p>Background</p> <p>The latest generation of Affymetrix microarrays are designed to interrogate expression over the entire length of every locus, thus giving the opportunity to study alternative splicing genome-wide. The Exon 1.0 ST (sense target) platform, with versions for Human, Mouse and Rat, is designed primarily to probe every known or predicted exon. The smaller Gene 1.0 ST array is designed as an expression microarray but still interrogates expression with probes along the full length of each well-characterized transcript. We explore the possibility of using the Gene 1.0 ST platform to identify differential splicing events.</p> <p>Results</p> <p>We propose a strategy to score differential splicing by using the auxiliary information from fitting the statistical model, RMA (robust multichip analysis). RMA partitions the probe-level data into probe effects and expression levels, operating robustly so that if a small number of probes behave differently than the rest, they are downweighted in the fitting step. We argue that adjacent poorly fitting probes for a given sample can be evidence of <it>differential </it>splicing and have designed a statistic to search for this behaviour. Using a public tissue panel dataset, we show many examples of tissue-specific alternative splicing. Furthermore, we show that evidence for putative alternative splicing has a strong correspondence between the Gene 1.0 ST and Exon 1.0 ST platforms.</p> <p>Conclusion</p> <p>We propose a new approach, FIRMAGene, to search for differentially spliced genes using the Gene 1.0 ST platform. Such an analysis complements the search for differential expression. We validate the method by illustrating several known examples and we note some of the challenges in interpreting the probe-level data.</p> <p>Software implementing our methods is freely available as an <monospace>R</monospace> package.</p

    Apoptosis of human melanoma cells induced by inhibition of B-RAFV600E involves preferential splicing of bimS

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    Bim is known to be critical in killing of melanoma cells by inhibition of the RAF/MEK/ERK pathway. However, the potential role of the most potent apoptosis-inducing isoform of Bim, BimS, remains largely unappreciated. Here, we show that inhibition of the mutant B-RAFV600E triggers preferential splicing to produce BimS, which is particularly important in induction of apoptosis in B-RAFV600E melanoma cells. Although the specific B-RAFV600E inhibitor PLX4720 upregulates all three major isoforms of Bim, BimEL, BimL, and BimS, at the protein and mRNA levels in B-RAFV600E melanoma cells, the increase in the ratios of BimS mRNA to BimEL and BimL mRNA indicates that it favours BimS splicing. Consistently, enforced expression of B-RAFV600E in wild-type B-RAF melanoma cells and melanocytes inhibits BimS expression. The splicing factor SRp55 appears necessary for the increase in BimS splicing, as SRp55 is upregulated, and its inhibition by small interfering RNA blocks induction of BimS and apoptosis induced by PLX4720. The PLX4720-induced, SRp55-mediated increase in BimS splicing is also mirrored in freshly isolated B-RAFV600E melanoma cells. These results identify a key mechanism for induction of apoptosis by PLX4720, and are instructive for sensitizing melanoma cells to B-RAFV600E inhibitors

    Endomembrane targeting of human OAS1 p46 augments antiviral activity

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    Many host RNA sensors are positioned in the cytosol to detect viral RNA during infection. However, most positive-strand RNA viruses replicate within a modified organelle co-opted from intracellular membranes of the endomembrane system, which shields viral products from cellular innate immune sensors. Targeting innate RNA sensors to the endomembrane system may enhance their ability to sense RNA generated by viruses that use these compartments for replication. Here, we reveal that an isoform of oligoadenylate synthetase 1, OAS1 p46, is prenylated and targeted to the endomembrane system. Membrane localization of OAS1 p46 confers enhanced access to viral replication sites and results in increased antiviral activity against a subset of RNA viruses including flaviviruses, picornaviruses, and SARS-CoV-2. Finally, our human genetic analysis shows that the OAS1 splice-site SNP responsible for production of the OAS1 p46 isoform correlates with protection from severe COVID-19. This study highlights the importance of endomembrane targeting for the antiviral specificity of OAS1 and suggests that early control of SARS-CoV-2 replication through OAS1 p46 is an important determinant of COVID-19 severity
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