336 research outputs found

    Comparison of five specific assays for determination of dabigatran plasma concentrations in patients enrolled in the START-Laboratory Register

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    Introduction: Several specific assays are commercially available to determine dabigatran anticoagulant activity. Aims of this multicenter and multiplatform study were to compare five methods for dabigatran measurement and investigate their performances in the low concentration range. Methods: Dabigatran levels were analyzed in 295 plasma samples from patients enrolled in the START-Laboratory Register by the following methods using dedicated calibrators and controls: STA-ECA II (Diagnostica Stago), standard and low range Hemoclot Thrombin Inhibitors (Hyphen BioMed), Direct Thrombin Inhibitor Assay (Instrumentation Laboratory), Direct Thrombin Inhibitor Assay (Siemens), Technoclot DTI (Technoclone). Results: Methods showed variable agreement with the Hemoclot Thrombin Inhibitors assay used as reference test, with modest under- or overestimations (Bland-Altman bias from −17.3 to 4.0 ng/mL). Limits of detection and quantification varied depending on the assay (4-52 and 7-82 ng/mL, respectively). Between-run precision and accuracy were good for all methods for both quality control levels. Assay's repeatability assessed at very low dabigatran concentrations (from 10 to 60 ng/mL) was also acceptable, variability generally increased at lower drug levels. Conclusion: The five dabigatran-specific assays evaluated in this study provided reliable assessment of dabigatran plasma levels, although showing different performances. © 2018 The Authors. International Journal of Laboratory Hematology Published by John Wiley & Sons Lt

    Electron exchange model potential: Application to positronium-helium scattering

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    The formulation of a suitable nonlocal model potential for electron exchange is presented, checked with electron-hydrogen and electron-helium scattering, and applied to the study of elastic and inelastic scattering and ionization of ortho positronium (Ps) by helium. The elastic scattering and the n=2n = 2 excitations of Ps are investigated using a three-Ps-state close-coupling approximation. The higher (n3n\ge 3) excitations and ionization of Ps atom are treated in the framework of Born approximation with present exchange. Calculations are reported of phase shifts, and elastic, Ps-excitation, and total cross sections. The present target elastic total cross section agrees well with experimental results at thermal to medium energies.Comment: 16 latex pages, 7 postscript figure

    Osteoarthritic changes in vervet monkey knees correlate with meniscus degradation and increased matrix metalloproteinase and cytokine secretion

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    Meniscus injury increases osteoarthritis risk but its pathobiology in osteoarthritis is unclear. We hypothesized that older adult vervet monkeys would exhibit knee osteoarthritic changes and the degenerative menisci from these animals would secrete matrix metalloproteinases (MMPs) and pro-inflammatory cytokines that contribute to the development of osteoarthritis

    Evaluation of the UK Public Health Skills and Knowledge Framework (PHSKF): Implications for international competency frameworks

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    Background: The value of competency frameworks for developing the public health workforce is widely acknowledged internationally. However, there is a lack of formal evaluations of such frameworks. In the UK, the Public Health Skills and Knowledge Framework (PHSKF) is a key tool for the public health workforce across the UK, and this study presents the evaluation of the PHSKF 2016 version, with the aim of reflecting on implications for international public health competency frameworks.Methods: A sequential explanatory design was employed. An online survey (n = 298) was completed with stakeholders across the four UK nations and different sectors. This was followed by 18 telephone interviews with stakeholders and survey completers. Quantitative results were analysed descriptively; qualitative transcripts were analysed with thematic analysis.Results: Most respondents had used the PHSKF occasionally or rarely, and most users found it useful (87%) and easy to use (82%). Main purposes of use included team/workforce development (e.g. setting of standards) and professional development (e.g. identify professional development opportunities). Some positive experiences emerged of uses of the PHSKF to support organisational redevelopments. However, 23% of respondents had never used the framework. Areas for improvement included greater clarity on purpose and audience, the need for more support from employers and for clear career progression opportunities, and stronger links with other competency frameworks.Conclusions: The development of a digital version of the PHSKF, together with improving buy-in from the workforce and employers could make an important contribution towards UK public health workforce development. Further evaluation and shared learning internationally of the implementation of public health competency frameworks would support global public health workforce development

    The combined effect of smoking tobacco and drinking alcohol on cause-specific mortality: a 30 year cohort study

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    <p><b>Background:</b> Smoking and consuming alcohol are both related to increased mortality risk. Their combined effects on cause-specific mortality were investigated in a prospective cohort study.</p> <p><b>Methods:</b> Participants were 5771 men aged 35-64, recruited during 1970-73 from various workplaces in Scotland. Data were obtained from a questionnaire and a screening examination. Causes of death were all cause, coronary heart disease (CHD), stroke, alcohol-related, respiratory and smoking-related cancer. Participants were divided into nine groups according to their smoking status (never, ex or current) and reported weekly drinking (none, 1-14 units and 15 or more). Cox proportional hazards models were used to obtain relative rates of mortality, adjusted for age and other risk factors.</p> <p><b>Results:</b> In 30 years of follow-up, 3083 men (53.4%) died. Compared with never smokers who did not drink, men who both smoked and drank 15+ units/week had the highest all-cause mortality (relative rate = 2.71 (95% confidence interval 2.31-3.19)). Relative rates for CHD mortality were high for current smokers, with a possible protective effect of some alcohol consumption in never smokers. Stroke mortality increased with both smoking and alcohol consumption. Smoking affected respiratory mortality with little effect of alcohol. Adjusting for a wide range of confounders attenuated the relative rates but the effects of alcohol and smoking still remained. Premature mortality was particularly high in smokers who drank 15 or more units, with a quarter of the men not surviving to age 65. 30% of men with manual occupations both smoked and drank 15+ units/week compared with only 13% with non-manual ones.</p> <p><b>Conclusions:</b> Smoking and drinking 15+ units/week was the riskiest behaviour for all causes of death.</p&gt

    Ultrafast relaxation of photoexcited carriers in semiconductor quantum wires: A Monte Carlo approach

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    A detailed analysis of the cooling and thermalization process for photogenerated carriers in semiconductor quantum wires is presented. The energy relaxation of the nonequilibrium carrier distribution is investigated for the ‘‘realistic'' case of a rectangular multisubband quantum-wire structure. By means of a direct ensemble Monte Carlo simulation of both the carrier and the phonon dynamics, all the nonlinear phenomena relevant for the relaxation process, such as carrier-carrier interaction, hot-phonon effects, and degeneracy, are investigated. The results of these simulated experiments show a significant reduction of the carrier-relaxation process compared to the bulk case, which is mainly due to the reduced efficiency of carrier-carrier scattering; on the contrary, the role of hot-phonon effects and degeneracy seems to be not so different from that played in bulk semiconductors

    Genome-wide association reveals three SNPs associated with sporadic amyotrophic lateral sclerosis through a two-locus analysis

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    <p>Abstract</p> <p>Background</p> <p>Amyotrophic lateral sclerosis (ALS) is a fatal, degenerative neuromuscular disease characterized by a progressive loss of voluntary motor activity. About 95% of ALS patients are in "sporadic form"-meaning their disease is not associated with a family history of the disease. To date, the genetic factors of the sporadic form of ALS are poorly understood.</p> <p>Methods</p> <p>We proposed a two-stage approach based on seventeen biological plausible models to search for two-locus combinations that have significant joint effects to the disease in a genome-wide association study (GWAS). We used a two-stage strategy to reduce the computational burden associated with performing an exhaustive two-locus search across the genome. In the first stage, all SNPs were screened using a single-marker test. In the second stage, all pairs made from the 1000 SNPs with the lowest p-values from the first stage were evaluated under each of the 17 two-locus models.</p> <p>Results</p> <p>we performed the two-stage approach on a GWAS data set of sporadic ALS from the SNP Database at the NINDS Human Genetics Resource Center DNA and Cell Line Repository <url>http://ccr.coriell.org/ninds/</url>. Our two-locus analysis showed that two two-locus combinations--rs4363506 (SNP1) and rs3733242 (SNP2), and rs4363506 and rs16984239 (SNP3) -- were significantly associated with sporadic ALS. After adjusting for multiple tests and multiple models, the combination of SNP1 and SNP2 had a p-value of 0.032 under the Dom∩Dom epistatic model; SNP1 and SNP3 had a p-value of 0.042 under the Dom × Dom multiplicative model.</p> <p>Conclusion</p> <p>The proposed two-stage analytical method can be used to search for joint effects of genes in GWAS. The two-stage strategy decreased the computational time and the multiple testing burdens associated with GWAS. We have also observed that the loci identified by our two-stage strategy can not be detected by single-locus tests.</p

    Cobalamin in inflammation III — glutathionylcobalamin and methylcobalamin/adenosylcobalamin coenzymes: the sword in the stone? How cobalamin may directly regulate the nitric oxide synthases

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    Several mysteries surround the structure and function of the nitric oxide synthases (NOS). The NOS oxygenase domain structure is unusually open with a large area of solvent that could accommodate an unidentified ligand. The exact mechanism of the two-step five-electron monoxygenation of arginine to NG-hydroxy-L-arginine, thence to citrulline and nitric oxide (NO), is not clear, particularly as arginine/NG-hydroxy-L-arginine is bound at a great distance to the supposed catalytic heme Fe [III], as the anti-stereoisomer. The Return of the Scarlet Pimpernel Paper proposed that cobalamin is a primary indirect regulator of the NOS. An additional direct regulatory effect of the ‘base-off’ dimethylbenzimidazole of glutathionylcobalamin (GSCbl), which may act as a sixth ligand to the heme iron, promote Co-oriented, BH4/BH3 radical catalysed oxidation of L-arginine to NO, and possibly regulate the rate of inducible NOS/NO production by the NOS dimers, is further advanced. The absence of homology between the NOS and methionine synthase/methylmalonyl CoA mutase may enable GSCbl to regulate both sets of enzymes simultaneously by completely separate mechanisms. Thus, cobalamin may exert central control over both pro-and anti-inflammatory systems

    Data monitoring roadmap. The experience of the Italian Multiple Sclerosis and Related Disorders Register

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    Introduction Over the years, disease registers have been increasingly considered a source of reliable and valuable population studies. However, the validity and reliability of data from registers may be limited by missing data, selection bias or data quality not adequately evaluated or checked.This study reports the analysis of the consistency and completeness of the data in the Italian Multiple Sclerosis and Related Disorders Register.MethodsThe Register collects, through a standardized Web-based Application, unique patients.Data are exported bimonthly and evaluated to assess the updating and completeness, and to check the quality and consistency. Eight clinical indicators are evaluated.ResultsThe Register counts 77,628 patients registered by 126 centres. The number of centres has increased over time, as their capacity to collect patients.The percentages of updated patients (with at least one visit in the last 24 months) have increased from 33% (enrolment period 2000-2015) to 60% (enrolment period 2016-2022). In the cohort of patients registered after 2016, there were &gt;= 75% updated patients in 30% of the small centres (33), in 9% of the medium centres (11), and in all the large centres (2).Clinical indicators show significant improvement for the active patients, expanded disability status scale every 6 months or once every 12 months, visits every 6 months, first visit within 1 year and MRI every 12 months.ConclusionsData from disease registers provide guidance for evidence-based health policies and research, so methods and strategies ensuring their quality and reliability are crucial and have several potential applications
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