97 research outputs found

    American postmodernist fiction and the past by Theophilus Savvas

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    A review of American Postmodernist Fiction and the Past by Theophilus Savva

    Preface

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    Preface to first issue of Orbit

    Selective EGF-Receptor Inhibition in CD4+ T Cells Induces Anergy and Limits Atherosclerosis.

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    BACKGROUND: Several epidermal growth factor receptor (EGFR) inhibitors have been successfully developed for the treatment of cancer, limiting tumor growth and metastasis. EGFR is also expressed by leukocytes, but little is known about its role in the modulation of the immune response. OBJECTIVES: The aim of this study was to determine whether EGFR expressed on CD4+ T cells is functional and to address the consequences of EGFR inhibition in atherosclerosis, a T cell-mediated vascular chronic inflammatory disease. METHODS: The authors used EGFR tyrosine kinase inhibitors (AG-1478, erlotinib) and chimeric Ldlr-/-Cd4-Cre/Egfrlox/lox mouse with a specific deletion of EGFR in CD4+ T cells. RESULTS: Mouse CD4+ T cells expressed EGFR, and the EGFR tyrosine kinase inhibitor AG-1478 blocked in vitro T cell proliferation and Th1/Th2 cytokine production. In vivo, treatment of Ldlr-/- mice with the EGFR inhibitor erlotinib induced T cell anergy, reduced T cell infiltration within atherosclerotic lesions, and protected against atherosclerosis development and progression. Selective deletion of EGFR in CD4+ T cells resulted in decreased T cell proliferation and activation both in vitro and in vivo, as well as reduced interferon-γ, interleukin-4, and interleukin-2 production. Atherosclerotic lesion size was reduced by 2-fold in irradiated Ldlr-/- mice reconstituted with bone marrow from Cd4-Cre/Egfrlox/lox mice, compared to Cd4-Cre/Egfr+/+ chimeric mice, after 4, 6, and 12 weeks of high-fat diet, associated with marked reduction in T cell infiltration in atherosclerotic plaques. Human blood T cells expressed EGFR and EGFR inhibition reduced T cell proliferation both in vitro and in vivo. CONCLUSIONS: EGFR blockade induced T cell anergy in vitro and in vivo and reduced atherosclerosis development. Targeting EGFR may be a novel strategy to combat atherosclerosis

    Modulation of RNA splicing enhances response to BCL2 inhibition in leukemia.

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    Therapy resistance is a major challenge in the treatment of cancer. Here, we performed CRISPR-Cas9 screens across a broad range of therapies used in acute myeloid leukemia to identify genomic determinants of drug response. Our screens uncover a selective dependency on RNA splicing factors whose loss preferentially enhances response to the BCL2 inhibitor venetoclax. Loss of the splicing factor RBM10 augments response to venetoclax in leukemia yet is completely dispensable for normal hematopoiesis. Combined RBM10 and BCL2 inhibition leads to mis-splicing and inactivation of the inhibitor of apoptosis XIAP and downregulation of BCL2A1, an anti-apoptotic protein implicated in venetoclax resistance. Inhibition of splicing kinase families CLKs (CDC-like kinases) and DYRKs (dual-specificity tyrosine-regulated kinases) leads to aberrant splicing of key splicing and apoptotic factors that synergize with venetoclax, and overcomes resistance to BCL2 inhibition. Our findings underscore the importance of splicing in modulating response to therapies and provide a strategy to improve venetoclax-based treatments

    Speciation and fate of trace metals in estuarine sediments under reduced and oxidized conditions, Seaplane Lagoon, Alameda Naval Air Station (USA)

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    We have identified important chemical reactions that control the fate of metal-contaminated estuarine sediments if they are left undisturbed (in situ) or if they are dredged. We combined information on the molecular bonding of metals in solids from X-ray absorption spectroscopy (XAS) with thermodynamic and kinetic driving forces obtained from dissolved metal concentrations to deduce the dominant reactions under reduced and oxidized conditions. We evaluated the in situ geochemistry of metals (cadmium, chromium, iron, lead, manganese and zinc) as a function of sediment depth (to 100 cm) from a 60 year record of contamination at the Alameda Naval Air Station, California. Results from XAS and thermodynamic modeling of porewaters show that cadmium and most of the zinc form stable sulfide phases, and that lead and chromium are associated with stable carbonate, phosphate, phyllosilicate, or oxide minerals. Therefore, there is minimal risk associated with the release of these trace metals from the deeper sediments contaminated prior to the Clean Water Act (1975) as long as reducing conditions are maintained. Increased concentrations of dissolved metals with depth were indicative of the formation of metal HS(- )complexes. The sediments also contain zinc, chromium, and manganese associated with detrital iron-rich phyllosilicates and/or oxides. These phases are recalcitrant at near-neutral pH and do not undergo reductive dissolution within the 60 year depositional history of sediments at this site. The fate of these metals during dredging was evaluated by comparing in situ geochemistry with that of sediments oxidized by seawater in laboratory experiments. Cadmium and zinc pose the greatest hazard from dredging because their sulfides were highly reactive in seawater. However, their dissolved concentrations under oxic conditions were limited eventually by sorption to or co-precipitation with an iron (oxy)hydroxide. About 50% of the reacted CdS and 80% of the reacted ZnS were bonded to an oxide-substrate at the end of the 90-day oxidation experiment. Lead and chromium pose a minimal hazard from dredging because they are bonded to relatively insoluble carbonate, phosphate, phyllosilicate, or oxide minerals that are stable in seawater. These results point out the specific chemical behavior of individual metals in estuarine sediments, and the need for direct confirmation of metal speciation in order to constrain predictive models that realistically assess the fate of metals in urban harbors and coastal sediments

    Time to treatment with bridging intravenous alteplase before endovascular treatment:subanalysis of the randomized controlled SWIFT-DIRECT trial.

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    BACKGROUND We hypothesized that treatment delays might be an effect modifier regarding risks and benefits of intravenous thrombolysis (IVT) before mechanical thrombectomy (MT). METHODS We used the dataset of the SWIFT-DIRECT trial, which randomized 408 patients to IVT+MT or MT alone. Potential interactions between assignment to IVT+MT and expected time from onset-to-needle (OTN) as well as expected time from door-to-needle (DTN) were included in regression models. The primary outcome was functional independence (modified Rankin Scale (mRS) 0-2) at 3 months. Secondary outcomes included mRS shift, mortality, recanalization rates, and (symptomatic) intracranial hemorrhage at 24 hours. RESULTS We included 408 patients (IVT+MT 207, MT 201, median age 72 years (IQR 64-81), 209 (51.2%) female). The expected median OTN and DTN were 142 min and 54 min in the IVT+MT group and 129 min and 51 min in the MT alone group. Overall, there was no significant interaction between OTN and bridging IVT assignment regarding either the functional (adjusted OR (aOR) 0.76, 95% CI 0.45 to 1.30) and safety outcomes or the recanalization rates. Analysis of in-hospital delays showed no significant interaction between DTN and bridging IVT assignment regarding the dichotomized functional outcome (aOR 0.48, 95% CI 0.14 to 1.62), but the shift and mortality analyses suggested a greater benefit of IVT when in-hospital delays were short. CONCLUSIONS We found no evidence that the effect of bridging IVT on functional independence is modified by overall or in-hospital treatment delays. Considering its low power, this subgroup analysis could have missed a clinically important effect, and exploratory analysis of secondary clinical outcomes indicated a potentially favorable effect of IVT with shorter in-hospital delays. Heterogeneity of the IVT effect size before MT should be further analyzed in individual patient meta-analysis of comparable trials. TRIAL REGISTRATION NUMBER URL: https://www. CLINICALTRIALS gov ; Unique identifier: NCT03192332

    Phase 3 trials of ixekizumab in moderate-to-severe plaque psoriasis

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    BACKGROUND Two phase 3 trials (UNCOVER-2 and UNCOVER-3) showed that at 12 weeks of treatment, ixekizumab, a monoclonal antibody against interleukin-17A, was superior to placebo and etanercept in the treatment of moderate-to-severe psoriasis. We report the 60-week data from the UNCOVER-2 and UNCOVER-3 trials, as well as 12-week and 60-week data from a third phase 3 trial, UNCOVER-1. METHODS We randomly assigned 1296 patients in the UNCOVER-1 trial, 1224 patients in the UNCOVER-2 trial, and 1346 patients in the UNCOVER-3 trial to receive subcutaneous injections of placebo (placebo group), 80 mg of ixekizumab every 2 weeks after a starting dose of 160 mg (2-wk dosing group), or 80 mg of ixekizumab every 4 weeks after a starting dose of 160 mg (4-wk dosing group). Additional cohorts in the UNCOVER-2 and UNCOVER-3 trials were randomly assigned to receive 50 mg of etanercept twice weekly. At week 12 in the UNCOVER-3 trial, the patients entered a long-term extension period during which they received 80 mg of ixekizumab every 4 weeks through week 60; at week 12 in the UNCOVER-1 and UNCOVER-2 trials, the patients who had a response to ixekizumab (defined as a static Physicians Global Assessment [sPGA] score of 0 [clear] or 1 [minimal psoriasis]) were randomly reassigned to receive placebo, 80 mg of ixekizumab every 4 weeks, or 80 mg of ixekizumab every 12 weeks through week 60. Coprimary end points were the percentage of patients who had a score on the sPGA of 0 or 1 and a 75% or greater reduction from baseline in Psoriasis Area and Severity Index (PASI 75) at week 12. RESULTS In the UNCOVER-1 trial, at week 12, the patients had better responses to ixekizumab than to placebo; in the 2-wk dosing group, 81.8% had an sPGA score of 0 or 1 and 89.1% had a PASI 75 response; in the 4-wk dosing group, the respective rates were 76.4% and 82.6%; and in the placebo group, the rates were 3.2% and 3.9% (P<0.001 for all comparisons of ixekizumab with placebo). In the UNCOVER-1 and UNCOVER-2 trials, among the patients who were randomly reassigned at week 12 to receive 80 mg of ixekizumab every 4 weeks, 80 mg of ixekizumab every 12 weeks, or placebo, an sPGA score of 0 or 1 was maintained by 73.8%, 39.0%, and 7.0% of the patients, respectively. Patients in the UNCOVER-3 trial received continuous treatment of ixekizumab from weeks 0 through 60, and at week 60, at least 73% had an sPGA score of 0 or 1 and at least 80% had a PASI 75 response. Adverse events reported during ixekizumab use included neutropenia, candidal infections, and inflammatory bowel disease. CONCLUSIONS In three phase 3 trials involving patients with psoriasis, ixekizumab was effective through 60 weeks of treatment. As with any treatment, the benefits need to be weighed against the risks of adverse events. The efficacy and safety of ixekizumab beyond 60 weeks of treatment are not yet known

    Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID-19 pandemic

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    BACKGROUND: During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study\u27s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines. METHODS: We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March-31 May 2020. The prior 1-year control period (1 March-31 May 2019) was obtained to account for seasonal variation. FINDINGS: There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI -24.3% to -20.7%, p\u3c0.0001). Embolisation of ruptured aneurysms declined with 1170-1035 procedures, respectively, representing an 11.5% (95%CI -13.5% to -9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI -28.0% to -22.1%, p\u3c0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile. INTERPRETATION: There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction

    Mechanisms of Resistance to Noncovalent Bruton's Tyrosine Kinase Inhibitors

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    BackgroundCovalent (irreversible) Bruton's tyrosine kinase (BTK) inhibitors have transformed the treatment of multiple B-cell cancers, especially chronic lymphocytic leukemia (CLL). However, resistance can arise through multiple mechanisms, including acquired mutations in BTK at residue C481, the binding site of covalent BTK inhibitors. Noncovalent (reversible) BTK inhibitors overcome this mechanism and other sources of resistance, but the mechanisms of resistance to these therapies are currently not well understood.MethodsWe performed genomic analyses of pretreatment specimens as well as specimens obtained at the time of disease progression from patients with CLL who had been treated with the noncovalent BTK inhibitor pirtobrutinib. Structural modeling, BTK-binding assays, and cell-based assays were conducted to study mutations that confer resistance to noncovalent BTK inhibitors.ResultsAmong 55 treated patients, we identified 9 patients with relapsed or refractory CLL and acquired mechanisms of genetic resistance to pirtobrutinib. We found mutations (V416L, A428D, M437R, T474I, and L528W) that were clustered in the kinase domain of BTK and that conferred resistance to both noncovalent BTK inhibitors and certain covalent BTK inhibitors. Mutations in BTK or phospholipase C gamma 2 (PLCγ2), a signaling molecule and downstream substrate of BTK, were found in all 9 patients. Transcriptional activation reflecting B-cell-receptor signaling persisted despite continued therapy with noncovalent BTK inhibitors.ConclusionsResistance to noncovalent BTK inhibitors arose through on-target BTK mutations and downstream PLCγ2 mutations that allowed escape from BTK inhibition. A proportion of these mutations also conferred resistance across clinically approved covalent BTK inhibitors. These data suggested new mechanisms of genomic escape from established covalent and novel noncovalent BTK inhibitors. (Funded by the American Society of Hematology and others.)
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