33 research outputs found
Automated entire thrombus density measurements for robust and comprehensive thrombus characterization in patients with acute ischemic stroke
Background and Purpose: In acute ischemic stroke (AIS) management, CT-based thrombus density has been associated with treatment success. However, currently used thrombus measurements are prone to inter-observer variability and oversimplify the heterogeneous thrombus composition. Our aim was first to introduce an automated method to assess the entire thrombus density and then to compare the measured entire thrombus density with respect to current standard manual measurements. Materials and Method: In 135 AIS patients, the density distribution of the entire thrombus was determined. Density distributions were described usingmedians, interquartile ranges (IQR), kurtosis, and skewedness. Differences between themedian of entire thrombusmeasurements and commonly applied manualmeasurements using 3 regions of interest were determined using linear regression. Results: Density distributions varied considerably with medians ranging from 20.0 to 62.8 HU and IQRs ranging from 9.3 to 55.8 HU. The average median of the thrombus density distributions (43.5 ± 10.2 HU) was lower than the manual assessment (49.6 ± 8.0 HU) (p<0.05). The difference between manual measurements and median density of entire thrombus decreased with increasing density (r = 0.64; p<0.05), revealing relatively higher manual measurements for low density thrombi such that manual density measurement tend overestimates the real thrombus density. Conclusions: Automatic measurements of the full thrombus expose a wide variety of thrombi density distribution, which is not grasped with currently used manual measurement. Furthermore, d
Two-year clinical follow-up of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands (MR CLEAN): Design and statistical analysis plan of the extended follow-up study
Background: MR CLEAN was the first randomized trial to demonstrate the short-term clinical effectiveness of endovascular treatment in patients with acute ischemic stroke caused by large vessel occlusion in the anterior circulation. Several other trials confirmed that endovascular treatment improves clinical outcome at three months. However, limited data are available on long-term clinical outcome. We aimed to estimate the effect of endovascular treatment on functional outcome at two-year follow-up in patients with acute ischemic stroke. Secondly, we aimed to assess the effect of endovascular treatment on major vascular events and mortality during two years of follow-up. Methods: MR CLEAN is a multicenter clinical trial with randomized treatment allocation, open-label treatment, and blinded endpoint evaluation. Patients included were 18 years or older with acute ischemic stroke caused by a proven anterior proximal artery occlusion who could be treated within six hours after stroke onset. The intervention contrast was endovascular treatment and usual care versus no endovascular treatment and usual care. The current study extended the follow-up duration from three months to two years. The primary outcome is the score on the modified Rankin scale at two years. Secondary outcomes include all-cause mortality and the occurrence of major vascular events within two years of follow-up. Discussion: The results of our study provide information on the long-term clinical effectiveness of endovascular treatment, which may have implications for individual treatment decisions and estimates of cost-effectiveness. Trial registration:NTR1804. Registered on 7 May 2009; ISRCTN10888758. Registered on 24 July 2012 (main MR CLEAN trial); NTR5073. Registered on 26 February 2015 (extended follow-up study)
Renal Epithelial Monolayer Formation on Monomeric and Polymeric Catechol Functionalized Supramolecular Biomaterials
Induction of a functional, tight monolayer of renal epithelial cells on a synthetic membrane to be applied in a bioartificial kidney device requires for bio-activation of the membrane. The current golden standard in bio-activation is the combination of a random polymeric catechol (L-DOPA) coating and collagen type IV (Col IV). Here the possibility of replacing this with defined monomeric catechol functionalization on a biomaterial surface using supramolecular ureido-pyrimidinone (UPy)-moieties is investigated. Monomeric catechols modified with a UPy-unit are successfully incorporated and presented in supramolecular UPy-polymer films and membranes. Unfortunately, these UPy-catechols are unable to improve epithelial cell monolayer formation over time, solely or in combination with Col IV. L-DOPA combined with Col IV is able to induce a tight monolayer capable of transport on electrospun supramolecular UPy-membranes. This study shows that a random polymeric catechol coating cannot be simply mimicked by defined monomeric catechols as supramolecular additives. There is still a long way to go in order to synthetically mimic simple natural structures
Renal Epithelial Monolayer Formation on Monomeric and Polymeric Catechol Functionalized Supramolecular Biomaterials
Induction of a functional, tight monolayer of renal epithelial cells on a synthetic membrane to be applied in a bioartificial kidney device requires for bio-activation of the membrane. The current golden standard in bio-activation is the combination of a random polymeric catechol (L-DOPA) coating and collagen type IV (Col IV). Here the possibility of replacing this with defined monomeric catechol functionalization on a biomaterial surface using supramolecular ureido-pyrimidinone (UPy)-moieties is investigated. Monomeric catechols modified with a UPy-unit are successfully incorporated and presented in supramolecular UPy-polymer films and membranes. Unfortunately, these UPy-catechols are unable to improve epithelial cell monolayer formation over time, solely or in combination with Col IV. L-DOPA combined with Col IV is able to induce a tight monolayer capable of transport on electrospun supramolecular UPy-membranes. This study shows that a random polymeric catechol coating cannot be simply mimicked by defined monomeric catechols as supramolecular additives. There is still a long way to go in order to synthetically mimic simple natural structures
The Effect of Postoperative Complications After Minimally Invasive Esophagectomy on Long-term Survival
Background: Esophagectomy is a technically challenging procedure, associated with significant morbidity. The introduction of minimally invasive esophagectomy (MIE) has reduced postoperative morbidity.
Objective: Although the short-term effect on complications is increasingly being recognized, the impact on long-term survival remains unclear. This study aims to investigate the association between postoperative complications following MIE and long-term survival.
Methods: Data were collected from the EsoBenchmark Collaborative composed by 13 high-volume, expert centers routinely performing MIE. Patients operated between June 1, 2011 and May 31, 2016 were included. Complications were graded using the Clavien-Dindo (CD) classification. To correct for short-term effects of postoperative complications on mortality, patients who died within 90 days postoperative were excluded. Primary endpoint was 5-year overall survival.
Results: A total of 915 patients were included with a mean follow-up time of 30.8 months (standard deviation 17.9). Complications occurred in 542 patients (59.2%) of which 50.2% had a CD grade â„III complication [ie, (re)intervention, organ dysfunction, or death]. The incidence of anastomotic leakage (AL) was 135 of 915 patients (14.8%) of which 84 patients were classified as a CD grade â„III. Multivariable analysis showed a significantly deteriorated long-term survival in all patients with AL [hazard ratio (HR) 1.68, 95% confidence interval (CI) 1.25-2.24]. This inverse relation was most distinct when AL was scored as a CD grade â„III (HR 1.83, 95% CI 1.30-2.58). For all other complications, no significant association with long-term survival was found.
Conclusion: The occurrence and severity of AL, but not overall complications, after MIE negatively affect long-term survival of esophageal cancer patients
Mapping of Gene Expression Reveals CYP27A1 as a Susceptibility Gene for Sporadic ALS
Amyotrophic lateral sclerosis (ALS) is a progressive, neurodegenerative disease characterized by loss of upper and lower motor neurons. ALS is considered to be a complex trait and genome-wide association studies (GWAS) have implicated a few susceptibility loci. However, many more causal loci remain to be discovered. Since it has been shown that genetic variants associated with complex traits are more likely to be eQTLs than frequency-matched variants from GWAS platforms, we conducted a two-stage genome-wide screening for eQTLs associated with ALS. In addition, we applied an eQTL analysis to finemap association loci. Expression profiles using peripheral blood of 323 sporadic ALS patients and 413 controls were mapped to genome-wide genotyping data. Subsequently, data from a two-stage GWAS (3,568 patients and 10,163 controls) were used to prioritize eQTLs identified in the first stage (162 ALS, 207 controls). These prioritized eQTLs were carried forward to the second sample with both gene-expression and genotyping data (161 ALS, 206 controls). Replicated eQTL SNPs were then tested for association in the second-stage GWAS data to find SNPs associated with disease, that survived correction for multiple testing. We thus identified twelve cis eQTLs with nominally significant associations in the second-stage GWAS data. Eight SNP-transcript pairs of highest significance (lowest p = 1.27 x 10(-51)) withstood multiple-testing correction in the second stage and modulated CYP27A1 gene expression. Additionally, we show that C9orf72 appears to be the only gene in the 9p21.2 locus that is regulated in cis, showing the potential of this approach in identifying causative genes in association loci in ALS. This study has identified candidate genes for sporadic ALS, most notably CYP27A1. Mutations in CYP27A1 are causal to cerebrotendinous xanthomatosis which can present as a clinical mimic of ALS with progressive upper motor neuron loss, making it a plausible susceptibility gene for ALS
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Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study 2010
BACKGROUND: Reliable and timely information on the leading causes of death in populations, and how these are changing, is a crucial input into health policy debates. In the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010), we aimed to estimate annual deaths for the world and 21 regions between 1980 and 2010 for 235 causes, with uncertainty intervals (UIs), separately by age and sex. METHODS: We attempted to identify all available data on causes of death for 187 countries from 1980 to 2010 from vital registration, verbal autopsy, mortality surveillance, censuses, surveys, hospitals, police records, and mortuaries. We assessed data quality for completeness, diagnostic accuracy, missing data, stochastic variations, and probable causes of death. We applied six different modelling strategies to estimate cause-specific mortality trends depending on the strength of the data. For 133 causes and three special aggregates we used the Cause of Death Ensemble model (CODEm) approach, which uses four families of statistical models testing a large set of different models using different permutations of covariates. Model ensembles were developed from these component models. We assessed model performance with rigorous out-of-sample testing of prediction error and the validity of 95% UIs. For 13 causes with low observed numbers of deaths, we developed negative binomial models with plausible covariates. For 27 causes for which death is rare, we modelled the higher level cause in the cause hierarchy of the GBD 2010 and then allocated deaths across component causes proportionately, estimated from all available data in the database. For selected causes (African trypanosomiasis, congenital syphilis, whooping cough, measles, typhoid and parathyroid, leishmaniasis, acute hepatitis E, and HIV/AIDS), we used natural history models based on information on incidence, prevalence, and case-fatality. We separately estimated cause fractions by aetiology for diarrhoea, lower respiratory infections, and meningitis, as well as disaggregations by subcause for chronic kidney disease, maternal disorders, cirrhosis, and liver cancer. For deaths due to collective violence and natural disasters, we used mortality shock regressions. For every cause, we estimated 95% UIs that captured both parameter estimation uncertainty and uncertainty due to model specification where CODEm was used. We constrained cause-specific fractions within every age-sex group to sum to total mortality based on draws from the uncertainty distributions. FINDINGS: In 2010, there were 52*8 million deaths globally. At the most aggregate level, communicable, maternal, neonatal, and nutritional causes were 24*9% of deaths worldwide in 2010, down from 15*9 million (34*1%) of 46*5 million in 1990. This decrease was largely due to decreases in mortality from diarrhoeal disease (from 2*5 to 1*4 million), lower respiratory infections (from 3*4 to 2*8 million), neonatal disorders (from 3*1 to 2*2 million), measles (from 0*63 to 0*13 million), and tetanus (from 0*27 to 0*06 million). Deaths from HIV/AIDS increased from 0*30 million in 1990 to 1*5 million in 2010, reaching a peak of 1*7 million in 2006. Malaria mortality also rose by an estimated 19*9% since 1990 to 1*17 million deaths in 2010. Tuberculosis killed 1*2 million people in 2010. Deaths from non-communicable diseases rose by just under 8 million between 1990 and 2010, accounting for two of every three deaths (34*5 million) worldwide by 2010. 8 million people died from cancer in 2010, 38% more than two decades ago; of these, 1*5 million (19%) were from trachea, bronchus, and lung cancer. Ischaemic heart disease and stroke collectively killed 12*9 million people in 2010, or one in four deaths worldwide, compared with one in five in 1990; 1*3 million deaths were due to diabetes, twice as many as in 1990. The fraction of global deaths due to injuries (5*1 million deaths) was marginally higher in 2010 (9*6%) compared with two decades earlier (8*8%). This was driven by a 46% rise in deaths worldwide due to road traffic accidents (1*3 million in 2010) and a rise in deaths from falls. Ischaemic heart disease, stroke, chronic obstructive pulmonary disease (COPD), lower respiratory infections, lung cancer, and HIV/AIDS were the leading causes of death in 2010. Ischaemic heart disease, lower respiratory infections, stroke, diarrhoeal disease, malaria, and HIV/AIDS were the leading causes of years of life lost due to premature mortality (YLLs) in 2010, similar to what was estimated for 1990, except for HIV/AIDS and preterm birth complications. YLLs from lower respiratory infections and diarrhoea decreased by 45-54% since 1990; ischaemic heart disease and stroke YLLs increased by 17-28%. Regional variations in leading causes of death were substantial. Communicable, maternal, neonatal, and nutritional causes still accounted for 76% of premature mortality in sub-Saharan Africa in 2010. Age standardised death rates from some key disorders rose (HIV/AIDS, Alzheimer's disease, diabetes mellitus, and chronic kidney disease in particular), but for most diseases, death rates fell in the past two decades; including major vascular diseases, COPD, most forms of cancer, liver cirrhosis, and maternal disorders. For other conditions, notably malaria, prostate cancer, and injuries, little change was noted. INTERPRETATION: Population growth, increased average age of the world's population, and largely decreasing age-specific, sex-specific, and cause-specific death rates combine to drive a broad shift from communicable, maternal, neonatal, and nutritional causes towards non-communicable diseases. Nevertheless, communicable, maternal, neonatal, and nutritional causes remain the dominant causes of YLLs in sub-Saharan Africa. Overlaid on this general pattern of the epidemiological transition, marked regional variation exists in many causes, such as interpersonal violence, suicide, liver cancer, diabetes, cirrhosis, Chagas disease, African trypanosomiasis, melanoma, and others. Regional heterogeneity highlights the importance of sound epidemiological assessments of the causes of death on a regular basis. FUNDING: Bill & Melinda Gates Foundation
Seventy-five genetic loci influencing the human red blood cell
Stress-related psychiatric disorders across the life spa