2,644 research outputs found

    Primary CNS Lymphoma

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    Primary diffuse large B-cell lymphoma (DLBCL) of the central nervous system is an aggressive malignancy that exhibits unique biological features and characteristic clinical behaviour, with overall long-term survival rates of around 20–40 %. Clinical outcome has improved following the advent of chemoradiation protocols incorporating high-dose methotrexate in the mid-1980s, but disease relapse and adverse neurocognitive sequelae remain major clinical challenges. To address this, investigators have focused on improving drug therapy with novel cytotoxic combinations, monoclonal antibody therapy, and intensive chemotherapy consolidation approaches, in an attempt to improve disease control whilst reducing the requirement for whole-brain radiotherapy. Outcomes for patients that are older, immunocompromised, or have relapsed/refractory disease remain unsatisfactory and there is a paucity of clinical trial data to guide treatment of these groups. This review highlights recent advances in pathobiology, imaging, and clinical management of PCNSL and looks ahead to research priorities for this rare and challenging lymphoid malignancy

    Simulating the effect of muscle weakness and contracture on neuromuscular control of normal gait in children

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    Altered neural control of movement and musculoskeletal deficiencies are common in children with spastic cerebral palsy (SCP), with muscle weakness and contracture commonly experienced. Both neural and musculoskeletal deficiencies are likely to contribute to abnormal gait, such as equinus gait (toe-walking), in children with SCP. However, it is not known whether the musculoskeletal deficiencies prevent normal gait or if neural control could be altered to achieve normal gait. This study examined the effect of simulated muscle weakness and contracture of the major plantarflexor/dorsiflexor muscles on the neuromuscular requirements for achieving normal walking gait in children. Initial muscle-driven simulations of walking with normal musculoskeletal properties by typically developing children were undertaken. Additional simulations with altered musculoskeletal properties were then undertaken; with muscle weakness and contracture simulated by reducing the maximum isometric force and tendon slack length, respectively, of selected muscles. Muscle activations and forces required across all simulations were then compared via waveform analysis. Maintenance of normal gait appeared robust to muscle weakness in isolation, with increased activation of weakened muscles the major compensatory strategy. With muscle contracture, reduced activation of the plantarflexors was required across the mid-portion of stance suggesting a greater contribution from passive forces. Increased activation and force during swing was also required from the tibialis anterior to counteract the increased passive forces from the simulated dorsiflexor muscle contracture. Improvements in plantarflexor and dorsiflexor motor function and muscle strength, concomitant with reductions in plantarflexor muscle stiffness may target the deficits associated with SCP that limit normal gait

    Neisseria meningitidis serogroup C sepsis and septic arthritis in an HIV-positive man

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    A patient with well-controlled HIV-1 infection presented with fever and rigors, a widespread maculopapular rash, and severe generalised arthralgia. Sepsis of unknown aetiology was diagnosed, and treatment with broad-spectrum antimicrobials commenced. Following initial clinical improvement, a right knee septic arthritis developed. Microscopy and culture of the joint aspirate were negative for organisms but 16S rDNA PCR identified Neisseria meningitidis DNA, subsequently verified as capsular genogroup C, thus confirming a diagnosis of disseminated meningococcal sepsis with secondary septic arthritis

    New Constraints (and Motivations) for Abelian Gauge Bosons in the MeV-TeV Mass Range

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    We survey the phenomenological constraints on abelian gauge bosons having masses in the MeV to multi-GeV mass range (using precision electroweak measurements, neutrino-electron and neutrino-nucleon scattering, electron and muon anomalous magnetic moments, upsilon decay, beam dump experiments, atomic parity violation, low-energy neutron scattering and primordial nucleosynthesis). We compute their implications for the three parameters that in general describe the low-energy properties of such bosons: their mass and their two possible types of dimensionless couplings (direct couplings to ordinary fermions and kinetic mixing with Standard Model hypercharge). We argue that gauge bosons with very small couplings to ordinary fermions in this mass range are natural in string compactifications and are likely to be generic in theories for which the gravity scale is systematically smaller than the Planck mass - such as in extra-dimensional models - because of the necessity to suppress proton decay. Furthermore, because its couplings are weak, in the low-energy theory relevant to experiments at and below TeV scales the charge gauged by the new boson can appear to be broken, both by classical effects and by anomalies. In particular, if the new gauge charge appears to be anomalous, anomaly cancellation does not also require the introduction of new light fermions in the low-energy theory. Furthermore, the charge can appear to be conserved in the low-energy theory, despite the corresponding gauge boson having a mass. Our results reduce to those of other authors in the special cases where there is no kinetic mixing or there is no direct coupling to ordinary fermions, such as for recently proposed dark-matter scenarios.Comment: 49 pages + appendix, 21 figures. This is the final version which appears in JHE

    A nationwide causal mediation analysis of survival following ST-elevation myocardial infarction

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    Objective: International studies report a decline in mortality following ST-elevation myocardial infarction (STEMI). The extent to which the observed improvements in STEMI survival are explained by temporal changes in patient characteristics and utilisation of treatments is unknown. Methods: Cohort study using national registry data from the Myocardial Ischaemia National Audit Project between first January 2004 and 30th June 2013. 232 353 survivors of hospitalisation with STEMI as recorded in 247 hospitals in England and Wales. Flexible parametric survival modelling and causal mediation analysis were used to estimate the relative contribution of temporal changes in treatments and patient characteristics on improved STEMI survival. Results: Over the study period, unadjusted survival at 6 months and 1 year improved by 0.9% and 1.0% on average per year (HR: 0.991, 95% CI: 0.988 to 0.994 and HR: 0.990, 95% CI: 0.987 to 0.993, respectively). The uptake of primary percutaneous coronary intervention (PCI) (HR: 1.025, 95% CI: 1.021 to 1.028) and increased prescription of P2Y12 inhibitors (HR: 1.035, 95% CI: 1.031 to 1.039) were significantly associated with improvements in 1-year survival. Primary PCI explained 16.8% (95% CI: 10.8% to 31.6%) and 13.2% (9.2% to 21.9%) of the temporal survival improvements at 6 months and 1 year, respectively, whereas P2Y12 inhibitor prescription explained 5.3% (3.6% to 8.8%) of the temporal improvements at 6 months but not at 1 year. Conclusions: For STEMI in England and Wales, improvements in survival between 2004 and 2013 were significantly explained by the uptake of primary PCI and increased use of P2Y12 inhibitors at 6 months and primary PCI only at 1 year. Trial registration number: NCT0374969

    Association of Clinical Factors and Therapeutic Strategies With Improvements in Survival Following Non-ST-Elevation Myocardial Infarction, 2003-2013.

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    Importance: International studies report a decline in mortality following non–ST-elevation myocardial infarction (NSTEMI). Whether this is due to lower baseline risk or increased utilization of guideline-indicated treatments is unknown. Objective: To determine whether changes in characteristics of patients with NSTEMI are associated with improvements in outcomes. Design, Setting, and Participants: Data on patients with NSTEMI in 247 hospitals in England and Wales were obtained from the Myocardial Ischaemia National Audit Project between January 1, 2003, and June 30, 2013 (final follow-up, December 31, 2013). Exposures: Baseline demographics, clinical risk (GRACE risk score), and pharmacological and invasive coronary treatments. Main Outcomes and Measures: Adjusted all-cause 180-day postdischarge mortality time trends estimated using flexible parametric survival modeling. Results: Among 389 057 patients with NSTEMI (median age, 72.7 years [IQR, 61.7-81.2 years]; 63.1% men), there were 113 586 deaths (29.2%). From 2003-2004 to 2012-2013, proportions with intermediate to high GRACE risk decreased (87.2% vs 82.0%); proportions with lowest risk increased (4.2% vs 7.6%; P= .01 for trend). The prevalence of diabetes, hypertension, cerebrovascular disease, chronic obstructive pulmonary disease, chronic renal failure, previous invasive coronary strategy, and current or ex-smoking status increased (all P < .001). Unadjusted all-cause mortality rates at 180 days decreased from 10.8% to 7.6% (unadjusted hazard ratio [HR], 0.968 [95% CI, 0.966-0.971]; difference in absolute mortality rate per 100 patients [AMR/100], −1.81 [95% CI, −1.95 to −1.67]). These findings were not substantially changed when adjusted additively by baseline GRACE risk score (HR, 0.975 [95% CI, 0.972-0.977]; AMR/100, −0.18 [95% CI, −0.21 to −0.16]), sex and socioeconomic status (HR, 0.975 [95% CI, 0.973-0.978]; difference in AMR/100, −0.24 [95% CI, −0.27 to −0.21]), comorbidities (HR, 0.973 [95% CI, 0.970-0.976]; difference in AMR/100, −0.44 [95% CI, −0.49 to −0.39]), and pharmacological therapies (HR, 0.972 [95% CI, 0.964-0.980]; difference in AMR/100, −0.53 [95% CI, −0.70 to −0.36]). However, the direction of association was reversed after further adjustment for use of an invasive coronary strategy (HR, 1.02 [95% CI, 1.01-1.03]; difference in AMR/100, 0.59 [95% CI, 0.33-0.86]), which was associated with a relative decrease in mortality of 46.1% (95% CI, 38.9%-52.0%). Conclusions and Relevance: Among patients hospitalized with NSTEMI in England and Wales, improvements in all-cause mortality were observed between 2003 and 2013. This was significantly associated with use of an invasive coronary strategy and not entirely related to a decline in baseline clinical risk or increased use of pharmacological therapies

    Evaluation of the impact of the GRACE risk score on the management and outcome of patients hospitalised with non-ST elevation acute coronary syndrome in the UK: protocol of the UKGRIS cluster-randomised registry-based trial

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    Introduction For non-ST-segment elevation acute coronary syndrome (NSTEACS) there is a gap between the use of class 1 guideline recommended therapies and clinical practice. The GRACE risk score is recommended in international guidelines for the risk stratification of NSTEACS, but its impact on adherence to guideline-indicated treatments and reducing adverse clinical outcomes is unknown. The objective of the UKGRIS trial is to assess the effectiveness of the GRACE risk score tool and associated treatment recommendations on the use of guideline-indicated care and clinical outcomes. Methods and Analysis The UK GRACE Risk Score Intervention Study (UKGRIS), a parallel-group cluster randomised registry-based controlled trial, will allocate hospitals in a 1:1 ratio to manage NSTEACS by standard care or according to the GRACE risk score and associated international guidelines. UKGRIS will recruit a minimum of 3000 patients from at least 30 English National Health Service hospitals and collect healthcare data from national electronic health records. The co-primary endpoints are the use of guideline-indicated therapies, and the composite of cardiovascular death, non-fatal myocardial infarction, new onset heart failure hospitalisation or cardiovascular readmission at 12 months. Secondary endpoints include duration of inpatient hospital stay over 12 months, EQ-5D-5L responses and utilities, unscheduled revascularisation and the components of the composite endpoint over 12 months follow-up. Ethics and Dissemination The study has ethical approval (North East - Tyne & Wear South Research Ethics Committee ref: 4/NE/1180). Findings will be announced at relevant conferences and published in peer-reviewed journals in line with the funder’s open access policy. Registration ISRCTN29731761, registered 12th January 2017
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