803 research outputs found

    Characterization of amoxicillin‐ and clavulanic acid‐specific T cells in patients with amoxicillin‐clavulanate–induced liver injury

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    Drug‐induced liver injury (DILI) frequently has a delayed onset with several human leukocyte antigen (HLA) genotypes affecting susceptibility, indicating a potential role for the adaptive immune system in the disease. The aim of this study was to investigate whether drug‐responsive T lymphocytes are detectable in patients who developed DILI with the combination, antimicrobial amoxicillin‐clavulanate. Lymphocytes from 6 of 7 patients were found to proliferate and/or secrete interferon‐gamma (IFN‐γ) when cultured with amoxicillin and/or clavulanic acid. Amoxicillin (n = 105) and clavulanic acid (n = 16) responsive CD4+ and CD8+ T‐cell clones expressing CCR, chemokine (C‐C motif) receptor 4, CCR9, and chemokine (C‐X‐C motif) receptor 3 were generated from patients with and without HLA risk alleles; no cross‐reactivity was observed between the two drug antigens. Amoxicillin clones were found to secrete a heterogeneous panel of mediators, including IFN‐γ, interleukin‐22 and cytolytic molecules. In contrast, cytokine secretion by the clavulanic acid clones was more restricted. CD4+ and CD8+ clones were major histocompatability complex class II and I restricted, respectively, with the drug antigen being presented to CD4+ clones in the context of HLA‐DR molecules. Several pieces of evidence indicate that the clones were activated by a hapten mechanism: First, professional antigen‐presenting cells (APCs) were required for optimal activation; second, pulsing APCs for 4‐16 hours activated the clones; and third, inhibition of processing abrogated the proliferative response and cytokine release. Conclusion: Both amoxicillin‐ and clavulanic acid–specific T cells participate in the liver injury that develops in certain patients exposed to amoxicillin‐clavulanate. (Hepatology 2015;62:887‐899

    What\u27s new in online news?

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    This paper examines aspects of the field of Information Systems (IS) concerned with its diversity and with the rapid changes within the discipline that have been incurred by the continued evolution of the IS artefact. This examination is done in order to establish the suitability of the Cynefin framework, developed for knowledge management, as a suitable tool for sense-making in IS. A description and assessment of the Cynefin framework is provided with its varied applications in both organisational practice and research. The paper then applies the framework to make sense of some historical trends and contemporary issues of IS emphasising their diversity and changing nature. We conclude with speculation on how this approach may help guide future sense-making in IS research

    Continuous Flow Synthesis of ZSM-5 Zeolite on the Order of Seconds

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    Zeolites have typically been synthesized via hydrothermal treatment, a process designed to artificially mimic the geological formation conditions of natural zeolites. This synthesis route, typically carried out in batch reactors like autoclaves, takes a time so long (typically, on the order of days) that the crystallization of zeolites had long been believed to be very slow in nature. Long periods of hydrothermal treatment also cause a burden on both energy efficiency and operational costs. Recently, we have reported the ultrafast syntheses of a class of industrially important zeolites within several minutes.[1,2] Further shortening the crystallization time to the order of seconds would be a great challenge but can significantly benefit the mass product of zeolites as well as the fundamental understanding of the crystallization mechanism

    Elevated Serum BAFF Levels in Patients with Systemic Sclerosis (SSc): Enhanced BAFF Signaling in SSc B Lymphocytes

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    Objective. To determine serum levels of BAFF, a potent B cell survival factor, in patients with systemic sclerosis (SSc) and relate the results to the clinical features of SSc. Methods. Serum BAFF levels in 83 patients with SSc were examined by enzyme-linked immunosorbent assay (ELISA). In a longitudinal study, 131 serum samples obtained from 21 patients with SSc were analyzed. The expression of BAFF messenger RNA (mRNA) in the skin was quantified by real-time reverse transcription-polymerase chain reaction. The expression of BAFF receptor (BAFFR) on CD19+ B cells was assessed by flow cytometry. The production of IgG and interleukin-6 (IL-6) by isolated B cells was examined by ELISA. Results. Serum BAFF levels were elevated in SSc patients compared with healthy controls and correlated positively with the extent of skin fibrosis. Among the 21 patients with SSc in the longitudinal study, 7 had decreased BAFF levels, 11 had levels that remained unchanged, and 3 patients had increased levels. Decreasing BAFF levels were accompanied by regression of skin sclerosis, whereas increasing levels of BAFF were associated with the new onset or worsening of organ involvement. BAFF mRNA expression was up-regulated in the affected skin of patients with early diffuse cutaneous SSc. BAFFR expression on B cells was increased in SSc patients relative to healthy controls. Furthermore, SSc B cells that were stimulated by BAFF exhibited an enhanced ability to produce IgG and IL-6. Conclusion. These results suggest that BAFF and its signaling in B cells contribute to B cell abnormalities and disease development in patients with SSc. © 2006, American College of Rheumatology

    IL-10 is Predominantly Produced by CD19(low)CD5(+) Regulatory B Cell Subpopulation: Characterisation of CD19 (high) and CD19(low) Subpopulations of CD5(+) B cells

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    IL-10 production by CD19(+)CD5(+) B cells was investigated, by determining the expression levels of CD19, a classical B cell marker. Peripheral mononuclear cells were stained with fluorescence-conjugated anti-CD5, anti-CD19, anti-IL-10, and Annexin V. Interestingly, IL-10-producing B cells were found to be localised within the CD19(low)CD5(+) B cell subset. Apoptotic changes were also observed mainly in CD19(low) cells among B cells. Thus, CD5(+) B cells should be classified as CD19(high) and CD19(low) cells, and the immunological significance of CD19 for the IL-10 production by CD5(+) B cells requires further studies

    Proteasome Inhibitor Bortezomib Ameliorates Intestinal Injury in Mice

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    Background: Bortezomib is a proteasome inhibitor that has shown impressive efficacy in the treatment of multiple myeloma. In mice, the addition of dextran sulfate sodium (DSS) to drinking water leads to acute colitis that can serve as an experimental animal model for human ulcerative colitis. Methodology/Principal Findings: Bortezomib treatment was shown to potently inhibit murine DSS-induced colitis. The attenuation of DSS-induced colitis was associated with decreased inflammatory cell infiltration in the colon. Specifically, bortezomib-treated mice showed significantly decreased numbers of CD4 + and CD8 + T cells in the colon and mesenteric lymph nodes. Bortezomib treatment significantly diminished interferon (IFN)-c expression in the colon and mesenteric lymph nodes. Furthermore, cytoplasmic IFN-c production by CD4 + and CD8 + T cells in mesenteric lymph nodes was substantially decreased by bortezomib treatment. Notably, bortezomib enhanced T cell apoptosis by inhibiting nuclear factor-kB activation during DSS-induced colitis. Conclusions/Significance: Bortezomib treatment is likely to induce T cell death, thereby suppressing DSS-induced colitis by reducing IFN-c production

    A portable dermatoscope for easy, rapid examination of periungual nailfold capillary changes in patients with systemic sclerosis.

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    Microvascular lesions are a predominant feature in systemic sclerosis (SSc) and seem to play a central pathogenic role. The presence of nailfold capillary abnormalities is useful in diagnosing SSc. Capillaroscopy, however, usually requires special equipment and may be time consuming. Dermatoscope has been presented as a new diagnostic tool for quick and efficient examination of nailfold capillaries for circumstances when standard microscope equipment is not available. To assess the practical utility of dermatoscope for assessment of capillary morphology in patients with SSc, 83 Japanese patients with SSc (68 women, 15 men) and 68 healthy controls were examined in the study. Twenty-one patients (16 women, 5 men) had diffuse cutaneous SSc and 62 (52 women, 10 men) had limited cutaneous SSc. Enlarged capillaries and hemorrhages were evaluated in all 10 fingers with either naked eyes or DermLite((R)) DL100 dermatoscope. Enlarged capillaries and hemorrhages were significantly more frequently detected with dermatoscope than without it. These findings were observed most frequently in the fourth finger. The presence of two or more enlarged capillaries in one or more fingers showed 83.1% sensitivity and 100% specificity for SSc. Among patients with SSc with anti-topoisomerase I antibody, the disease duration correlated negatively with the dermatoscopic number of enlarged capillaries and hemorrhages. Dermatoscope allows the easy and rapid identification of capillary nailfold morphological changes in SSc and should be routinely used for diagnosing SSc.The original publication is available at www.springerlink.co

    NFATc1 supports imiquimod-induced skin inflammation by suppressing IL-10 synthesis in B cells

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    Epicutaneous application of Aldara cream containing the TLR7 agonist imiquimod (IMQ) to mice induces skin inflammation that exhibits many aspects of psoriasis, an inflammatory human skin disease. Here we show that mice depleted of B cells or bearing interleukin (IL)-10-deficient B cells show a fulminant inflammation upon IMQ exposure, whereas ablation of NFATc1 in B cells results in a suppression of Aldara-induced inflammation. In vitro, IMQ induces the proliferation and IL-10 expression by B cells that is blocked by BCR signals inducing NFATc1. By binding to HDAC1, a transcriptional repressor, and to an intronic site of the Il10 gene, NFATc1 suppresses IL-10 expression that dampens the production of tumour necrosis factor-α and IL-17 by T cells. These data indicate a close link between NFATc1 and IL-10 expression in B cells and suggest NFATc1 and, in particular, its inducible short isoform, NFATc1/αA, as a potential target to treat human psoriasis

    The Role of B Cells in Transplantation and Immunopathic Diseases

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    B cells, by virtue of their diverse roles in immune responses to foreign and self antigens, have become of increasing interest to the clinician as well as the basic immunologist. In particular, it is now apparent that the development of B cell unresponsiveness in antibody and T cell mediated autoimmune disorders and the transplant setting is both worthwhile and achievable
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