280 research outputs found

    Learners’ confusion: faulty prior knowledge or a metacognitive monitoring error?

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    Research often treats confusion as a turning point of the learners’ cognitive-affective dynamics in digital environments (e.g. D’Mello, Grasser and colleagues). The origin of confusion, however, is a topic of a debate. Could inaccurate prior knowledge serve as a source of confusion, or does confusion relate to metacognitive processes? In this paper we are attempting to address this question by employing case study analysis with fourteen participants who worked through simulated learning problems with feedback in a digital environment. Physiological and self-reported data were combined to examine problem-solving patterns. Preliminary findings highlighted the role of metacognitive monitoring in confusion development and its interrelation with inaccurate prior knowledge.5 page(s

    Efficacy of thalidomide in a girl with inflammatory calcinosis, a severe complication of juvenile dermatomyositis

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    We report a 14-year-old girl with juvenile dermatomyositis (JDM) complicated by severe inflammatory calcinosis successfully treated with thalidomide. She was diagnosed as JDM when she was 4 years old after a few months of increasing lethargy, muscle pain, muscle weakness, and rash. During three months, clinical manifestations and abnormal laboratory findings were effectively treated with oral prednisolone. However, calcinosis was recognized 18 months after disease onset. Generalized calcinosis rapidly progressed with high fever, multiple skin/subcutaneous inflammatory lesions, and increased level of CRP. Fifty mg/day (1.3 mg/kg day) of oral thalidomide was given for the first four weeks, and then the dose was increased to 75 mg/day. Clinical manifestations subsided, and inflammatory markers had clearly improved. Frequent high fever and local severe pain with calcinosis were suppressed. The levels of FDP-E, IgG, and tryglyceride, which were all elevated before the thalidomide treatment, were gradually returned to the normal range. Over the 18 months of observation up to the present, she has had no inflammatory calcinosis, or needed any hospitalization, although established calcium deposits still remain. Her condition became painless, less extensive and less inflammatory with the CRP level below 3.08 mg/dL. Recent examination by whole-body 18F-FDG-PET-CT over the 15 months of thalidomide treatment demonstrated fewer hot spots around the subcutaneous calcified lesions

    Transcriptomes of peripheral blood mononuclear cells from juvenile dermatomyositis patients show elevated inflammation even when clinically inactive

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    In juvenile dermatomyositis (JDM), the most common pediatric inflammatory myopathy, weakness is accompanied by a characteristic rash that often becomes chronic and is associated with vascular damage. We hoped to understand the molecular underpinnings of JDM, particularly when untreated, which would facilitate the identification of novel mechanisms and clinical targets that might disrupt disease progression. We studied the RNA-Seq data from untreated JDM peripheral blood mononuclear cells (PBMCs; n = 11), PBMCs from a subset of the same patients when clinically inactive (n = 8/11), and separate samples of untreated JDM skin and muscle (n = 4 each). All JDM samples were compared to non-inflammatory control tissues. The untreated JDM PBMCs showed a strong signature for type1 interferon response, along with IL-1, IL-10, and NF-κB. Surprisingly, PBMCs from clinically inactive JDM individuals had persistent immune activation that was enriched for IL-1 signaling. JDM skin and muscle both showed evidence for type 1 interferon activation and genes related to antigen presentation and decreased expression of cellular respiration genes. Additionally, we found that PBMC gene expression correlates with disease activity scores (DAS; skin, muscle, and total domains) and with nailfold capillary end row loop number (an indicator of microvascular damage). This included otoferlin, which was significantly increased in untreated JDM PBMCs and correlated with all 3 DAS domains. Overall, these data demonstrate that PBMC transcriptomes are informative of molecular disruptions in JDM and provide transcriptional evidence of chronic inflammation despite clinical quiescence

    Dysregulated NK cell PLCÎł2 signaling and activity in juvenile dermatomyositis

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    Juvenile dermatomyositis (JDM) is a debilitating pediatric autoimmune disease manifesting with characteristic rash and muscle weakness. To delineate signaling abnormalities in JDM, mass cytometry was performed with PBMCs from treatment-naive JDM patients and controls. NK cell percentages were lower while frequencies of naive B cells and naive CD4+ T cells were higher in JDM patients than in controls. These cell frequency differences were attenuated with cessation of active disease. A large number of signaling differences were identified in treatment-naive JDM patients compared with controls. Classification models incorporating feature selection demonstrated that differences in phospholipase CÎł2 (PLCÎł2) phosphorylation comprised 10 of 12 features (i.e., phosphoprotein in a specific immune cell subset) distinguishing the 2 groups. Because NK cells represented 5 of these 12 features, further studies focused on the PLCÎł2 pathway in NK cells, which is responsible for stimulating calcium flux and cytotoxic granule movement. No differences were detected in upstream signaling or total PLCÎł2 protein levels. Hypophosphorylation of PLCÎł2 and downstream mitogen-activated protein kinase-activated protein kinase 2 were partially attenuated with cessation of active disease. PLCÎł2 hypophosphorylation in treatment-naive JDM patients resulted in decreased calcium flux. The identification of dysregulation of PLCÎł2 phosphorylation and decreased calcium flux in NK cells provides potential mechanistic insight into JDM pathogenesis

    IgG and IgA autoantibodies against L1 ORF1p expressed in granulocytes correlate with granulocyte consumption and disease activity in pediatric systemic lupus erythematosus

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    BACKGROUND: Most patients with systemic lupus erythematosus (SLE) have IgG autoantibodies against the RNA-binding p40 (ORF1p) protein encoded by the L1 retroelement. This study tested if these autoantibodies are also present in children with pediatric SLE (pSLE) and if the p40 protein itself could be detected in immune cells. METHODS: Autoantibodies in the plasma of pSLE patients (n = 30), healthy children (n = 37), and disease controls juvenile idiopathic arthritis (JIA) (n = 32) and juvenile dermatomyositis (JDM) (n = 60), were measured by ELISA. Expression of p40 in immune cells was assessed by flow cytometry. Markers of neutrophil activation and death were quantitated by ELISA. RESULTS: IgG and IgA autoantibodies reactive with p40 were detected in the pSLE patients, but were low in healthy controls and in JIA or JDM. pSLE patients with active disease (13 of them newly diagnosed) had higher titers than the same patients after effective therapy (p = 0.0003). IgG titers correlated with SLEDAI (r = 0.65, p = 0.0001), ESR (r = 0.43, p = 0.02), and anti-dsDNA antibodies (r = 0.49, p < 0.03), and inversely with complement C3 (r = -0.55, p = 0.002) and C4 (r = -0.51, p = 0.006). p40 protein was detected in a subpopulation of CD66b(+) granulocytes in pSLE, as well as in adult SLE patients. Myeloperoxidase and neutrophil elastase complexed with DNA and the neutrophil-derived S100A8/A9 were elevated in plasma from pSLE patients with active disease and correlated with anti-p40 autoantibodies and disease activity. CONCLUSIONS: Children with active SLE have elevated IgG and IgA autoantibodies against L1 p40, and this protein can be detected in circulating granulocytes in both pediatric and adult SLE patients. P40 expression and autoantibody levels correlate with disease activity. Markers of neutrophil activation and death also correlate with these autoantibodies and with disease activity, suggesting that neutrophils express L1 and are a source of p40. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13075-021-02538-3

    Immunogenetic studies of juvenile dermatomyositis

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66141/1/j.1399-0039.1983.tb00371.x.pd

    Genome-wide imputation identifies novel associations and localises signals in idiopathic inflammatory myopathies.

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    OBJECTIVES The idiopathic inflammatory myopathies (IIM) are heterogeneous diseases, thought to be initiated by immune activation in genetically predisposed individuals. In this study we imputed variants from the Immunochip array using a large reference panel to fine-map associations and identify novel associations in IIM. METHODS We analysed 2,565 Caucasian IIM samples collected through the Myositis Genetics Consortium (MYOGEN) and 10,260 ethnically-matched controls. We imputed 1,648,116 variants from the Immunochip array using the Haplotype Reference Consortium panel and conducted association analysis on IIM, and clinical and serological subgroups. RESULTS The human leukocyte antigen (HLA) locus was consistently the most significantly associated region. Four non-HLA regions reached genome-wide significance, three in the whole IIM cohort (SDK2 and LINC00924 - both novel, and STAT4), with evidence of independent variants in STAT4, and NAB1 in the polymyositis (PM) subgroup. We also found suggestive evidence of association with loci previously associated with other autoimmune rheumatic diseases (TEC and LTBR). We identified more significant associations than those previously reported in IIM, for STAT4 and DGKQ in the total cohort, for NAB1 and FAM167A-BLK loci in PM, and CCR5 in inclusion body myositis. We found enrichment of variants among DNase I hypersensitivity sites and histone marks associated with active transcription within blood cells. CONCLUSIONS We report novel and strong associations in IIM and PM, and localise signals to single genes and immune cell types. This article is protected by copyright. All rights reserved
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