1,014 research outputs found
When REBOA grows wings: Resuscitative endovascular balloon occlusion of the aorta to facilitate aeromedical transport
BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a helpful adjunct in the control of non-compressible truncal hemorrhage. Concerns regarding ischemia time limits its applicability in transfer. We describe the first reported case of civilian transfer via aeromedical transport to a higher level of care with a zone 3 REBOA catheter deployed.
CASE REPORT: We present the case of a patient in hemorrhagic shock with a complex pelvic fracture exceeding the capability of a rural level-two trauma center requiring the use of REBOA catheter to permit aeromedical transport to a level-one trauma center for definitive embolization.
CONCLUSION: Deployment of REBOA catheter to facilitate aeromedical transport to an appropriate level of care may be considered if travel times can be kept brief and there is a process and training in place to empower flight medics to consider transporting with a REBOA deployed
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Calibrating from Within: Multipoint Internal Calibration of a Quantitative Mass Spectrometric Assay of Serum Methotrexate.
BACKGROUND:Clinical LC-MS/MS assays traditionally require that samples be run in batches with calibration curves in each batch. This approach is inefficient and presents a barrier to random access analysis. We developed an alternative approach called multipoint internal calibration (MPIC) that eliminated the need for batch-mode analysis. METHODS:The new approach used 4 variants of 13C-labeled methotrexate (0.026-10.3 µM) as an internal calibration curve within each sample. One site carried out a comprehensive validation, which included an evaluation of interferences and matrix effects, lower limit of quantification (LLOQ), and 20-day precision. Three sites evaluated assay precision and linearity. MPIC was also compared with traditional LC-MS/MS and an immunoassay. RESULTS:Recovery of spiked analyte was 93%-102%. The LLOQ was validated to be 0.017 µM. Total variability, determined in a 20-day experiment, was 11.5%CV. In a 5-day variability study performed at each site, total imprecision was 3.4 to 16.8%CV. Linearity was validated throughout the calibrator range (r2 > 0.995, slopes = 0.996-1.01). In comparing 40 samples run in each laboratory, the median interlaboratory imprecision was 6.55%CV. MPIC quantification was comparable to both traditional LC-MS/MS and immunoassay (r2 = 0.96-0.98, slopes = 1.04-1.06). Bland-Altman analysis of all comparisons showed biases rarely exceeding 20% when MTX concentrations were >0.4 µM. CONCLUSION:The MPIC method for serum methotrexate quantification was validated in a multisite proof-of-concept study and represents a big step toward random-access LC-MS/MS analysis, which could change the paradigm of mass spectrometry in the clinical laboratory
Quantitative Clinical Chemistry Proteomics (qCCP) using mass spectrometry: general characteristics and application
Proteomics studies typically aim to exhaustively detect peptides/proteins in a given biological sample. Over the past decade, the number of publications using proteomics methodologies has exploded. This was made possible due to the availability of high-quality genomic data and many technological advances in the fields of microfluidics and mass spectrometry. Proteomics in biomedical research was initially used in ‘functional' studies for the identification of proteins involved in pathophysiological processes, complexes and networks. Improved sensitivity of instrumentation facilitated the analysis of even more complex sample types, including human biological fluids. It is at that point the field of clinical proteomics was born, and its fundamental aim was the discovery and (ideally) validation of biomarkers for the diagnosis, prognosis, or therapeutic monitoring of disease. Eventually, it was recognized that the technologies used in clinical proteomics studies [particularly liquid chromatography-tandem mass spectrometry (LC-MS/MS)] could represent an alternative to classical immunochemical assays. Prior to deploying MS in the measurement of peptides/proteins in the clinical laboratory, it seems likely that traditional proteomics workflows and data management systems will need to adapt to the clinical environment and meet in vitro diagnostic (IVD) regulatory constraints. This defines a new field, as reviewed in this article, that we have termed quantitative Clinical Chemistry Proteomics (qCCP
Reliability of causality assessment for drug, herbal and dietary supplement hepatotoxicity in the Drug‐Induced Liver Injury Network (DILIN)
Background & AimsBecause of the lack of objective tests to diagnose drug‐induced liver injury (DILI), causality assessment is a matter of debate. Expert opinion is often used in research and industry, but its test–retest reliability is unknown. To determine the test–retest reliability of the expert opinion process used by the Drug‐Induced Liver Injury Network (DILIN).MethodsThree DILIN hepatologists adjudicate suspected hepatotoxicity cases to one of five categories representing levels of likelihood of DILI. Adjudication is based on retrospective assessment of gathered case data that include prospective follow‐up information. One hundred randomly selected DILIN cases were re‐assessed using the same processes for initial assessment but by three different reviewers in 92% of cases.ResultsThe median time between assessments was 938 days (range 140–2352). Thirty‐one cases involved >1 agent. Weighted kappa statistics for overall case and individual agent category agreement were 0.60 (95% CI: 0.50–0.71) and 0.60 (0.52–0.68) respectively. Overall case adjudications were within one category of each other 93% of the time, while 5% differed by two categories and 2% differed by three categories. Fourteen per cent crossed the 50% threshold of likelihood owing to competing diagnoses or atypical timing between drug exposure and injury.ConclusionsThe DILIN expert opinion causality assessment method has moderate interobserver reliability but very good agreement within one category. A small but important proportion of cases could not be reliably diagnosed as ≥50% likely to be DILI.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111130/1/liv12540.pd
Under-reporting and Poor Adherence to Monitoring Guidelines for Severe Cases of Isoniazid Hepatotoxicity
IMPORTANCE: Mutations in known causal Alzheimer disease (AD) genes account for only 1% to 3% of patients and almost all are dominantly inherited. Recessive inheritance of complex phenotypes can be linked to long (>1-megabase [Mb]) runs of homozygosity (ROHs) detectable by single-nucleotide polymorphism (SNP) arrays.
OBJECTIVE: To evaluate the association between ROHs and AD in an African American population known to have a risk for AD up to 3 times higher than white individuals.
DESIGN, SETTING, AND PARTICIPANTS: Case-control study of a large African American data set previously genotyped on different genome-wide SNP arrays conducted from December 2013 to January 2015. Global and locus-based ROH measurements were analyzed using raw or imputed genotype data. We studied the raw genotypes from 2 case-control subsets grouped based on SNP array: Alzheimer's Disease Genetics Consortium data set (871 cases and 1620 control individuals) and Chicago Health and Aging Project-Indianapolis Ibadan Dementia Study data set (279 cases and 1367 control individuals). We then examined the entire data set using imputed genotypes from 1917 cases and 3858 control individuals.
MAIN OUTCOMES AND MEASURES: The ROHs larger than 1 Mb, 2 Mb, or 3 Mb were investigated separately for global burden evaluation, consensus regions, and gene-based analyses.
RESULTS: The African American cohort had a low degree of inbreeding (F ~ 0.006). In the Alzheimer's Disease Genetics Consortium data set, we detected a significantly higher proportion of cases with ROHs greater than 2 Mb (P = .004) or greater than 3 Mb (P = .02), as well as a significant 114-kilobase consensus region on chr4q31.3 (empirical P value 2 = .04; ROHs >2 Mb). In the Chicago Health and Aging Project-Indianapolis Ibadan Dementia Study data set, we identified a significant 202-kilobase consensus region on Chr15q24.1 (empirical P value 2 = .02; ROHs >1 Mb) and a cluster of 13 significant genes on Chr3p21.31 (empirical P value 2 = .03; ROHs >3 Mb). A total of 43 of 49 nominally significant genes common for both data sets also mapped to Chr3p21.31. Analyses of imputed SNP data from the entire data set confirmed the association of AD with global ROH measurements (12.38 ROHs >1 Mb in cases vs 12.11 in controls; 2.986 Mb average size of ROHs >2 Mb in cases vs 2.889 Mb in controls; and 22% of cases with ROHs >3 Mb vs 19% of controls) and a gene-cluster on Chr3p21.31 (empirical P value 2 = .006-.04; ROHs >3 Mb). Also, we detected a significant association between AD and CLDN17 (empirical P value 2 = .01; ROHs >1 Mb), encoding a protein from the Claudin family, members of which were previously suggested as AD biomarkers.
CONCLUSIONS AND RELEVANCE: To our knowledge, we discovered the first evidence of increased burden of ROHs among patients with AD from an outbred African American population, which could reflect either the cumulative effect of multiple ROHs to AD or the contribution of specific loci harboring recessive mutations and risk haplotypes in a subset of patients. Sequencing is required to uncover AD variants in these individuals
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Modeling hepatic fibrosis in African American and Caucasian American patients with chronic hepatitis C virus infection
Assessment of histological stage is an integral part of disease management in patients infected with the hepatitis C virus (HCV). The aim of this study was to develop a model incorporating objective clinical and laboratory parameters to estimate the probability of severe fibrosis ( i.e. , Ishak fibrosis ≥ 3) in previously untreated African American (AA) and Caucasian American (CA) patients with HCV genotype 1. The Ishak fibrosis scores of 205 CA and 194 AA patients enrolled in the Viral Resistance to Antiviral Therapy of Chronic Hepatitis C study (Virahep-C) were modeled using simple and multiple logistic regression. The model was then validated in an independent cohort of 461 previously untreated patients with HCV. The distribution of fibrosis scores was similar in the AA and CA patients as was the proportion of patients with severe fibrosis (35% vs. 39%, P = .47). After accounting for the number of portal areas in the biopsy, patient age, serum aspartate aminotransferase, alkaline phosphatase, and platelet count were independently associated with severe fibrosis in the overall cohort, and the relationship with fibrosis was similar in both the AA and CA subgroups. The area under the receiver operating characteristic curve (AUROC) of the Virahep-C model (0.837) was significantly better than in other published models ( P = .0003). The AUROC of the Virahep-C model was 0.851 in the validation population. In conclusion , a model consisting of widely available clinical and laboratory features predicted severe hepatic fibrosis equally well in AA and CA patients with HCV genotype 1 and was superior to other published models. The excellent performance of the Virahep-C model in an external validation cohort suggests the findings are replicable and potentially generalizable. (H EPATOLOGY 2006;44:925–935.)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55833/1/21335_ftp.pd
A pilot study to evaluate the application of a generic protein standard panel for quality control of biomarker detection technologies
<p>Abstract</p> <p>Background</p> <p>Protein biomarker studies are currently hampered by a lack of measurement standards to demonstrate quality, reliability and comparability across multiple assay platforms. This is especially pertinent for immunoassays where multiple formats for detecting target analytes are commonly used.</p> <p>Findings</p> <p>In this pilot study a generic panel of six non-human protein standards (50 - 10^7 pg/mL) of varying abundance was prepared as a quality control (QC) material. Simulated "normal" and "diseased" panels of proteins were prepared in pooled human plasma and incorporated into immunoassays using the Meso Scale Discovery<sup>® </sup>(MSD<sup>®</sup>) platform to illustrate reliable detection of the component proteins. The protein panel was also evaluated as a spike-in material for a model immunoassay involving detection of ovarian cancer biomarkers within individual human plasma samples. Our selected platform could discriminate between two panels of the proteins exhibiting small differences in abundance. Across distinct experiments, all component proteins exhibited reproducible signal outputs in pooled human plasma. When individual donor samples were used, half the proteins produced signals independent of matrix effects. These proteins may serve as a generic indicator of platform reliability.</p> <p>Each of the remaining proteins exhibit differential signals across the distinct samples, indicative of sample matrix effects, with the three proteins following the same trend. This subset of proteins may be useful for characterising the degree of matrix effects associated with the sample which may impact on the reliability of quantifying target diagnostic biomarkers.</p> <p>Conclusions</p> <p>We have demonstrated the potential utility of this panel of standards to act as a generic QC tool for evaluating the reproducibility of the platform for protein biomarker detection independent of serum matrix effects.</p
Big data: Finders keepers, losers weepers?
This article argues that big data’s entrepreneurial potential is based not only on new technological developments that allow for the extraction of non-trivial, new insights out of existing data, but also on an ethical judgment that often remains implicit: namely the ethical judgment that those companies that generate these new insights can legitimately appropriate (the fruits of) these insights. As a result, the business model of big data companies is essentially founded on a libertarian-inspired ‘finders, keepers’ ethic. The article argues, next, that this presupposed ‘finder, keepers’ ethic is far from unproblematic and relies itself on multiple unconvincing assumptions. This leads to the conclusion that the conduct of companies working with big data might lack ethical justification
Americans, Marketers, and the Internet: 1999-2012
This is a collection of the reports on the Annenberg national surveys that explored Americans\u27 knowledge and opinions about the new digital-marketing world that was becoming part of their lives. So far we’ve released seven reports on the subject, in 1999, 2000, 2003, 2005, 2009, 2010, and 2012. The reports raised or deepened a range of provocative topics that have become part of public, policy, and industry discourse. In addition to these reports, I’ve included three journal articles — from I/S, New Media & Society and the Journal of Consumer Affairs — that synthesize some of the findings and place them into policy frameworks. The journals have kindly allowed reproduction for this purpose
Hepatic histological findings in suspected drug‐induced liver injury: Systematic evaluation and clinical associations
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102713/1/hep26709.pd
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