490 research outputs found

    Evidence of Exponential Decay Emission in the Swift Gamma-ray Bursts

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    We present a systematic study of the steep decay emission from gamma-ray bursts (GRBs) observed by the Swift X-Ray Telescope (XRT). In contrast to the analysis described in recent literature, we produce composite Burst Alert Telescope (BAT) and XRT light curves by extrapolating the XRT data (2-10 keV) into the BAT energy range (15-25 keV) rather than extrapolating the BAT data into the XRT energy band (0.3-10 keV). Based on the fits to the composite light curves, we have confirmed the existence of an exponential decay component which smoothly connects the BAT prompt data to the XRT steep decay for several GRBs. We also find that the XRT steep decay for some of the bursts can be well fit by a combination of a power-law with an exponential decay model. We discuss this exponential component within the frame work of both the internal and the external shock model.Comment: 33 pages, 34 figures; accepted for publication in Ap

    Evidence of the Exponential Decay Emission in the Swift Gamma-ray Bursts

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    We present a systematic study of the steep decay emission of gamma-ray bursts (GRBs) observed by the Swift X-Ray Telescope (XRT). In contrast to the analysis in recent literature, instead of extrapolating the data of Burst Alert Telescope (BAT) down into the XRT energy range, we extrapolated the XRT data up to the BAT energy range, 15-25 keV, to produce the BAT and XRT composite light curve. Based on our composite light curve fitting, we have confirmed the existence of an exponential decay component which smoothly connects the BAT prompt data to the XRT steep decay for several GRBs. We also find that the XRT steep decay for some of the bursts can be well fitted by a combination of a power-law with an exponential decay model. We discuss that this exponential component may be the emission from an external shock and a sign of the deceleration of the outflow during the prompt phase

    Concurrent irinotecan, oxaliplatin and UFT in first-line treatment of metastatic colorectal cancer: a Phase I study

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    The feasibility of combining UFT plus leucovorin (LV) with alternating irinotecan and oxaliplatin was investigated in the first-line treatment of patients with advanced colorectal cancer. Twenty-five patients, median age 63 (range 24–79) years, World Health Organisation performance status 0–2 and median four marker lesions, received irinotecan 180 mg m−2 on day 1, oxaliplatin 85–100 mg m−2 on day 15 and UFT 200–300 mg m−2 day−1 with LV 90 mg day−1, days 1–21 of a 28-day cycle. Patients were treated in cohorts of three. At the highest dose (irinotecan 180 mg m−2, oxaliplatin 100 mg m−2 and UFT 300 mg m−2 day−1), three of four patients experienced grade 3 toxicity. Diarrhoea, lethargy and vomiting were dose-limiting. Three of nine patients had grade 2 toxicities at the maximum tolerated dose (irinotecan 180 mg m−2, oxaliplatin 100 mg m−2 and UFT 250 mg m−2 day−1). There were no grade 3 toxicities in the first month of therapy. The overall response rate was 71% in 21 evaluable patients; progression-free survival was 8.8 months. Alternating irinotecan and oxaliplatin plus UFT is an effective and well-tolerated first-line treatment for patients with advanced colorectal cancer. We recommend a dose of irinotecan 180 mg m−2 on day 1, oxaliplatin 100 mg m−2 on day 15 and UFT 250 mg m−2 day−1 with LV 90 mg day−1 on days 1–21 of a 28-day cycle for future studies

    Psoriasis drug development and GWAS interpretation through in silico analysis of transcription factor binding sites

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    BackgroundPsoriasis is a cytokine‐mediated skin disease that can be treated effectively with immunosuppressive biologic agents. These medications, however, are not equally effective in all patients and are poorly suited for treating mild psoriasis. To develop more targeted therapies, interfering with transcription factor (TF) activity is a promising strategy.MethodsMeta‐analysis was used to identify differentially expressed genes (DEGs) in the lesional skin from psoriasis patients (n = 237). We compiled a dictionary of 2935 binding sites representing empirically‐determined binding affinities of TFs and unconventional DNA‐binding proteins (uDBPs). This dictionary was screened to identify “psoriasis response elements” (PREs) overrepresented in sequences upstream of psoriasis DEGs.ResultsPREs are recognized by IRF1, ISGF3, NF‐kappaB and multiple TFs with helix‐turn‐helix (homeo) or other all‐alpha‐helical (high‐mobility group) DNA‐binding domains. We identified a limited set of DEGs that encode proteins interacting with PRE motifs, including TFs (GATA3, EHF, FOXM1, SOX5) and uDBPs (AVEN, RBM8A, GPAM, WISP2). PREs were prominent within enhancer regions near cytokine‐encoding DEGs (IL17A, IL19 and IL1B), suggesting that PREs might be incorporated into complex decoy oligonucleotides (cdODNs). To illustrate this idea, we designed a cdODN to concomitantly target psoriasis‐activated TFs (i.e., FOXM1, ISGF3, IRF1 and NF‐kappaB). Finally, we screened psoriasis‐associated SNPs to identify risk alleles that disrupt or engender PRE motifs. This identified possible sites of allele‐specific TF/uDBP binding and showed that PREs are disproportionately disrupted by psoriasis risk alleles.ConclusionsWe identified new TF/uDBP candidates and developed an approach that (i) connects transcriptome informatics to cdODN drug development and (ii) enhances our ability to interpret GWAS findings. Disruption of PRE motifs by psoriasis risk alleles may contribute to disease susceptibility.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155494/1/ctm2s4016901500545-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155494/2/ctm2s4016901500545-sup-0018.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155494/3/ctm2s4016901500545-sup-0002.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155494/4/ctm2s4016901500545.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155494/5/ctm2s4016901500545-sup-0009.pd

    Proteogenomic analysis of psoriasis reveals discordant and concordant changes in mRNA and protein abundance

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    Abstract Background Psoriasis is a chronic disease characterized by the development of scaly red skin lesions and possible co-morbid conditions. The psoriasis lesional skin transcriptome has been extensively investigated, but mRNA levels do not necessarily reflect protein abundance. The purpose of this study was therefore to compare differential expression patterns of mRNA and protein in psoriasis lesions. Methods Lesional (PP) and uninvolved (PN) skin samples from 14 patients were analyzed using high-throughput complementary DNA sequencing (RNA-seq) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results We identified 4122 differentially expressed genes (DEGs) along with 748 differentially expressed proteins (DEPs). Global shifts in mRNA were modestly correlated with changes in protein abundance (r = 0.40). We identified similar numbers of increased and decreased DEGs, but 4-fold more increased than decreased DEPs. Ribosomal subunit and translation proteins were elevated within lesions, without a corresponding shift in mRNA expression (RPL3, RPS8, RPL11). We identified 209 differentially expressed genes/proteins (DEGPs) with corresponding trends at the transcriptome and proteome levels. Most DEGPs were similarly altered in at least one other skin disease. Psoriasis-specific and non-specific DEGPs had distinct cytokine-response patterns, with only the former showing disproportionate induction by IL-17A in cultured keratinocytes. Conclusions Our findings reveal global imbalance between the number of increased and decreased proteins in psoriasis lesions, consistent with heightened translation. This effect could not have been discerned from mRNA profiling data alone. High-confidence DEGPs were identified through transcriptome-proteome integration. By distinguishing between psoriasis-specific and non-specific DEGPs, our analysis uncovered new functional insights that would otherwise have been overlooked.http://deepblue.lib.umich.edu/bitstream/2027.42/112309/1/13073_2015_Article_208.pd

    Analysis of long non-coding RNAs highlights tissue-specific expression patterns and epigenetic profiles in normal and psoriatic skin

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    Abstract Background Although analysis pipelines have been developed to use RNA-seq to identify long non-coding RNAs (lncRNAs), inference of their biological and pathological relevance remains a challenge. As a result, most transcriptome studies of autoimmune disease have only assessed protein-coding transcripts. Results We used RNA-seq data from 99 lesional psoriatic, 27 uninvolved psoriatic, and 90 normal skin biopsies, and applied computational approaches to identify and characterize expressed lncRNAs. We detect 2,942 previously annotated and 1,080 novel lncRNAs which are expected to be skin specific. Notably, over 40% of the novel lncRNAs are differentially expressed and the proportions of differentially expressed transcripts among protein-coding mRNAs and previously-annotated lncRNAs are lower in psoriasis lesions versus uninvolved or normal skin. We find that many lncRNAs, in particular those that are differentially expressed, are co-expressed with genes involved in immune related functions, and that novel lncRNAs are enriched for localization in the epidermal differentiation complex. We also identify distinct tissue-specific expression patterns and epigenetic profiles for novel lncRNAs, some of which are shown to be regulated by cytokine treatment in cultured human keratinocytes. Conclusions Together, our results implicate many lncRNAs in the immunopathogenesis of psoriasis, and our results provide a resource for lncRNA studies in other autoimmune diseases.http://deepblue.lib.umich.edu/bitstream/2027.42/110307/1/13059_2014_Article_570.pd

    Language matters. Addressing the use of language in the care of people with diabetes: position statement of the English Advisory Group

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    The language used by healthcare professionals can have a profound impact on how people living with diabetes, and those who care for them, experience their condition and feel about living with it day-to-day. At its best, good use of language, both verbal and written, can lower anxiety, build confidence, educate and help to improve self-care. Conversely, poor communication can be stigmatizing, hurtful and undermining of self-care and can have a detrimental effect on clinical outcomes. The language used in the care of those with diabetes has the power to reinforce negative stereotypes, but it also has the power to promote positive ones. The use of language is controversial and has many perspectives. The development of this position statement aimed to take account of these as well as the current evidence base. A working group, representing people with diabetes and key organizations with an interest in the care of people with diabetes, was established to review the use of language. The work of this group has culminated in this position statement for England. It follows the contribution of Australia and the USA to this important international debate. The group has set out practical examples of language that will encourage positive interactions with those living with diabetes and subsequently promote positive outcomes. These examples are based on a review of the evidence and are supported by a simple set of principles

    Cellular dissection of psoriasis for transcriptome analyses and the post-GWAS era

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    Abstract Background Genome-scale studies of psoriasis have been used to identify genes of potential relevance to disease mechanisms. For many identified genes, however, the cell type mediating disease activity is uncertain, which has limited our ability to design gene functional studies based on genomic findings. Methods We identified differentially expressed genes (DEGs) with altered expression in psoriasis lesions (n = 216 patients), as well as candidate genes near susceptibility loci from psoriasis GWAS studies. These gene sets were characterized based upon their expression across 10 cell types present in psoriasis lesions. Susceptibility-associated variation at intergenic (non-coding) loci was evaluated to identify sites of allele-specific transcription factor binding. Results Half of DEGs showed highest expression in skin cells, although the dominant cell type differed between psoriasis-increased DEGs (keratinocytes, 35%) and psoriasis-decreased DEGs (fibroblasts, 33%). In contrast, psoriasis GWAS candidates tended to have highest expression in immune cells (71%), with a significant fraction showing maximal expression in neutrophils (24%, P < 0.001). By identifying candidate cell types for genes near susceptibility loci, we could identify and prioritize SNPs at which susceptibility variants are predicted to influence transcription factor binding. This led to the identification of potentially causal (non-coding) SNPs for which susceptibility variants influence binding of AP-1, NF-κB, IRF1, STAT3 and STAT4. Conclusions These findings underscore the role of innate immunity in psoriasis and highlight neutrophils as a cell type linked with pathogenetic mechanisms. Assignment of candidate cell types to genes emerging from GWAS studies provides a first step towards functional analysis, and we have proposed an approach for generating hypotheses to explain GWAS hits at intergenic loci.http://deepblue.lib.umich.edu/bitstream/2027.42/109537/1/12920_2013_Article_485.pd
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