431 research outputs found
Stroke outcome in clinical trial patients deriving from different countries
<p><b>Background and Purpose:</b> Stroke incidence and outcome vary widely within and across geographical locations. We examined whether differences in index stroke severity, stroke risk factors, mortality, and stroke outcome across geographical locations remain after adjusting for case mix.</p>
<p><b>Methods:</b> We analyzed 3284 patients from the Virtual International Stroke Trials Archive (VISTA). We used logistic regression to examine the incidence of mild index stroke, functional, and neurological outcomes after accounting for age, medical history, year of trial recruitment, and initial stroke severity in the functional and neurological outcome analyses. We examined mortality between geographical regions using a Cox proportional hazards model, accounting for age, initial stroke severity, medical history, and year of trial recruitment.</p>
<p><b>Results</b> Patients enrolled in the USA and Canada had the most severe index strokes. Those recruited in Austria and Switzerland had the best functional and neurological outcomes at 90 days (P<0.05), whereas those enrolled in Germany had the worst functional outcome at 90 days (P=0.013). Patients enrolled in Austria, Switzerland, Belgium, Netherlands, Finland, Germany, Greece, Israel, Spain, and Portugal had a significantly better survival rate when compared with those enrolled in USA and Canada. Patients enrolled in trials after 1998 had more severe index strokes, with no significant difference in outcome compared with those enrolled before 1998.</p>
<p><b>Conclusion:</b> We identified regional variations in index stroke severity, outcome, and mortality for patients enrolled in ischemic stroke clinical trials over the past 13 years that were not fully explained by case mix. Index stroke severity was greater in patients enrolled after 1998, with no significant improvement in outcomes compared to those enrolled before 1998.</p>
Delay-Induced Transient Oscillations in a Two-Neuron Network
Finite transmission times between neurons, referred to as delays, may appear in hardware implementation of neural networks. We analyze the dynamics of a two-neuron network in which the delay modifies the transient and not the long-term behavior of the network. We show that the delay causes some trajectories to oscillate transiently before reaching stationary behavior and the duration of these transients increases exponentially with the delay. Such a phenomeno deteriorates network performance
Additional outcomes and subgroup analyses of NXY-059 for acute ischemic stroke in the SAINT I trial
<p><b>Background and Purpose:</b> NXY-059 is a free radical-trapping neuroprotectant demonstrated to reduce disability from ischemic stroke. We conducted analyses on additional end points and sensitivity analyses to confirm our findings.</p>
<p><b>Methods:</b> We randomized 1722 patients with acute ischemic stroke to a 72-hour infusion of placebo or intravenous NXY-059 within 6 hours of stroke onset. The primary outcome was disability at 90 days, as measured by the modified Rankin Scale (mRS), a 6-point scale ranging from 0 (no residual symptoms) to 5 (bed-bound, requiring constant care). Additional and exploratory analyses included mRS at 7 and 30 days; subgroup interactions with final mRS; assessments of activities of daily living by Barthel index; and National Institutes of Health Stroke Scale (NIHSS) neurological scores at 7 and 90 days.</p>
<p><b>Results:</b> NXY-059 significantly improved the distribution of the mRS disability score compared with placebo at 7, 30, and 90 days (Cochran-Mantel-Haenszel test P=0.002, 0.004, 0.038, respectively; 90-day common odds ratio 1.20; 95% CI, 1.01 to 1.42). The benefit was not attributable to any specific baseline characteristic, stratification variable or subgroup interaction. Neurological scores were improved at 7 days (odds ratio [OR], 1.46; 95% CI, 1.13, 1.89; P=0.003) and the Barthel index was improved at 7 and 30 days (OR, 1.55; 95% CI, 1.22, 1.98; P<0.0001; OR, 1.27; 95% CI, 1.01, 1.59; P=0.02).</p>
<p><b>Conclusions:</b> NXY-059 within 6 hours of acute ischemic stroke significantly reduced disability. Benefit on neurological scores and activities of daily living was detectable early but not significant at 90 days; however, our trial was underpowered to measure effects on the neurological examination. The benefit on disability is not confounded by interactions and is supported by other outcome measures.</p>
NXY-059 for the treatment of acute stroke: pooled analysis of the SAINT I and II trials
<p><b>Background and Purpose:</b> In animal models of acute ischemic stroke (AIS), the free radical-trapping agent NXY-059 showed promise as a neuroprotectant. SAINT I and II were randomized, placebo-controlled, double-blind trials to investigate the efficacy of NXY-059 in patients with AIS.</p>
<p><b>Methods:</b> Patients with AIS received an infusion of intravenous NXY-059 or placebo within 6 hours from the onset of stroke symptoms. A pooled individual patient analysis was prespecified to assess the overall efficacy and to examine subgroups. The primary end point was the distribution of disability scores measured on the modified Rankin scale (mRS) at 90 days. Neurologic and activities of daily living scores were investigated as secondary end points. We also evaluated whether treatment with NXY-059 would reduce alteplase-related intracranial hemorrhages. Finally, we evaluated possible predictors of good or poor outcome.</p>
<p><b>Results:</b> An intent-to-treat efficacy analysis was based on 5028 patients. Baseline parameters and prognostic factors were well balanced between treatment groups. The distribution of scores on the mRS was not different in the group treated with NXY-059 (n = 2438) compared with the placebo group (n = 2456): odds ratio for limiting disability = 1.02; 95% CI, 0.92 to 1.13 (P = 0.682, Cochran-Mantel-Haenszel test). Comparisons at each level of the mRS confirmed an absence of benefit. There was no evidence of efficacy in prespecified subgroups or from the secondary outcome analyses. Mortality was equal in the 2 groups (16.7% vs 16.5%), and adverse event rates were similar. Among patients treated with alteplase, there was no decrease in rates of symptomatic or asymptomatic hemorrhage associated with NXY-059 treatment versus placebo. Subgroup analyses identified National Institutes of Health Stroke Scale score, age, markers of inflammation, blood glucose, and right-sided infarct as predictors of poor outcome.</p>
<p><b>Conclusions:</b> NXY-059 is ineffective for treatment of AIS within 6 hours of symptom onset. This is also true for subgroups and the prevention of alteplase-associated hemorrhage.</p>
The Virtual International Stroke Trials Archive
BACKGROUND AND PURPOSE: Stroke has global importance and it causes an increasing amount of human suffering and economic burden, but its management is far from optimal. The unsuccessful outcome of several research programs highlights the need for reliable data on which to plan future clinical trials. The Virtual International Stroke Trials Archive aims to aid the planning of clinical trials by collating and providing access to a rich resource of patient data to perform exploratory analyses.
METHODS: Data were contributed by the principal investigators of numerous trials from the past 16 years. These data have been centrally collated and are available for anonymized analysis and hypothesis testing.
RESULTS: Currently, the Virtual International Stroke Trials Archive contains 21 trials. There are data on \u3e15,000 patients with both ischemic and hemorrhagic stroke. Ages range between 18 and 103 years, with a mean age of 69+/-12 years. Outcome measures include the Barthel Index, Scandinavian Stroke Scale, National Institutes of Health Stroke Scale, Orgogozo Scale, and modified Rankin Scale. Medical history and onset-to-treatment time are readily available, and computed tomography lesion data are available for selected trials.
CONCLUSIONS: This resource has the potential to influence clinical trial design and implementation through data analyses that inform planning
Association of Phosphodiesterase-5 Inhibitors Versus Alprostadil With Survival in Men With Coronary Artery Disease
Abstract Background Phosphodiesterase 5 inhibitor (PDE5i) treatment is associated with reduced mortality compared with no treatment for erectile dysfunction after myocardial infarction (MI). Objectives This study sought to investigate the association between treatment with PDE5i or alprostadil and outcomes in men with stable coronary artery disease. Methods All Swedish men with a prior MI or revascularization who received PDE5i or alprostadil during 2006 through 2013 at >6 months after the event were included, using the Swedish Patient Register and the Swedish Prescribed Drug Register. Cox regression was used to estimate adjusted hazard ratios with 95% confidence intervals for all-cause mortality, MI, heart failure, cardiovascular mortality, noncardiovascular mortality, cardiac revascularization, peripheral arterial disease, and stroke in men treated with PDE5i versus alprostadil. Results This study included 16,548 men treated with PDE5i and 1,994 treated with alprostadil. The mean follow-up was 5.8 years, with 2,261 deaths (14%) in the PDE5i group and 521 (26%) in the alprostadil group. PDE5i compared with alprostadil treatment was associated with lower mortality (hazard ratio: 0.88; 95% confidence interval: 0.79 to 0.98) and with similar associations for MI, heart failure, cardiovascular mortality, and revascularization. When quintiles (q) of filled PDE5i prescriptions were compared using q1 as reference, patients in q3, q4, and q5 had lower all-cause mortality. Among alprostadil users, those in q5 had a lower all-cause mortality compared to q1. Conclusions In men with stable coronary artery disease, treatment with PDE5i is associated with lower risks of death, MI, heart failure, and revascularization compared with alprostadil treatment. Although the decrease in all-cause mortality was PDE5i dose dependent, the data do not permit the inference of causality or any clinical benefits of PDE5i because of the observational study design
Effects of alteplase for acute stroke on the distribution of functional outcomes: a pooled analysis of 9 trials
Background—Thrombolytic therapy with intravenous alteplase within 4.5 hours of ischemic stroke onset increases the overall likelihood of an excellent outcome (no, or nondisabling, symptoms). Any improvement in functional outcome distribution has value, and herein we provide an assessment of the effect of alteplase on the distribution of the functional level by treatment delay, age, and stroke severity.
Methods—Prespecified pooled analysis of 6756 patients from 9 randomized trials comparing alteplase versus placebo/open control. Ordinal logistic regression models assessed treatment differences after adjustment for treatment delay, age, stroke severity, and relevant interaction term(s).
Results—Treatment with alteplase was beneficial for a delay in treatment extending to 4.5 hours after stroke onset, with a greater benefit with earlier treatment. Neither age nor stroke severity significantly influenced the slope of the relationship between benefit and time to treatment initiation. For the observed case mix of patients treated within 4.5 hours of stroke onset (mean 3 hours and 20 minutes), the net absolute benefit from alteplase (ie, the difference between those who would do better if given alteplase and those who would do worse) was 55 patients per 1000 treated (95% confidence interval, 13–91; P=0.004).
Conclusions—Treatment with intravenous alteplase initiated within 4.5 hours of stroke onset increases the chance of achieving an improved level of function for all patients across the age spectrum, including the over 80s and across all severities of stroke studied (top versus bottom fifth means: 22 versus 4); the earlier that treatment is initiated, the greater the benefit
Lumbar spine bone mineral density and trabecular bone score-adjusted FRAX, but not FRAX without bone mineral density, identify subclinical carotid atherosclerosis
Purpose: Osteoporosis and atherosclerosis share common risk factors. Aim of this study was to test if FRAX (which is an algorithm that can identify subjects at risk of fracture), without or with BMD values, also adjusted for trabecular bone score (TBS) was able to identify subclinical atherosclerosis, evaluated by measurement of carotid intima media thickness (cIMT ≥ 0.9 mm) as compared to DXA values. Methods: Ninety postmenopausal women underwent DXA measurement and cIMT evaluation. For each patient, the FRAX algorithm for major osteoporotic fracture (M) and for hip fracture (H) without BMD was computed, together with FRAX with BMD and TBS-adjusted FRAX. Serum levels of osteoprotegerin, sRANKL, and interleukin-6 were also measured. Results: There were no differences in anthropometric parameters and cardiovascular risk factors between subjects with cIMT ≥ 0.9 mm (35% of subjects, group A) compared to those with cIMT < 0.9 mm (group B). The prevalence of osteoporosis and FRAX BMD, TBS-adjusted FRAX both for M and H were higher in group A compared to group B. The best ROC curves to identify subjects with a cIMT ≥ 0.9 mm were: lumbar spine T-score, with a threshold of − 2.5 SD (area under the curve, AUC 0.64; p = 0.02) with a sensibility of 50% and a specificity of 76%; TBS-adjusted FRAX H with a sensibility of 50% and a specificity of 72% (AUC 0.64; p = 0.01 with a threshold of 3%). Interleukin-6 positively correlated with FRAX BMD H and M. Conclusions: FRAX without BMD does not identify subclinical carotid atherosclerosis, while lumbar spine T-score and TBS-adjusted FRAX H similarly detected it with higher specificity for T-score
Thickness dependant characterization of chemically exfoliated TiS2 nanosheets
Monolayer TiS2 is the lightest member of the transition metal dichalcogenides family with promising application in energy storage and conversion systems. Use of TiS2 has been limited by the lack of rapid characterisation of layer number via Raman spectroscopy and its easy oxidation in wet environment. Here, we demonstrate layer number dependent Raman modes for TiS2. 1T-TiS2 presents two characteristics Raman active modes, A1g (out-of-plane) and Eg (in-plane). We identified a characteristic peak frequency shift of the Eg mode with the layer number and an unexplored Raman mode at 372 cm-1 whose intensity changes relative to the A1g mode with the thickness of TiS2 sheets. These two characteristic features of the Raman spectra allow the determination of layer numbers between 1 and 5 in exfoliated TiS2. Further, we develop a method to produce oxidation-resistant inks of micron sized mono- and few-layered TiS2 nanosheets at concentrations up to 1 mg/mL .These TiS2 inks can be deposited to form thin films with controllable thickness and nanosheet density over cm2 areas. This opens up pathways for a wider utilization of exofliated TiS2 towards a range of applications
News vs. Advertising: Does the Audience Perceive the ‘Journalistic Distinction’?
Evidence indicates the audience does not perceive either news or advertising as a homogeneous content category, distinct from the other, in the media.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
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