1,897 research outputs found
Detection of mRNA for the terminal complement components C5, C6, C8 and C9 in human umbilical vein endothelial cells in vitro.
No full textHuman umbilical vein endothelial cells (HUVEC) have previously been shown to synthesize the functional terminal pathway of complement based on the detection by radioimmunoassay of the terminal complement complex (TCC) on coincubated agarose beads. In addition, C7 secretion by these cells in amounts comparable to C3, as well as C7 mRNA, has recently been demonstrated. However, it has not been possible to detect C5-6 and C8 in the fluid phase, and only trace amounts of soluble C9. Against this background we examined whether mRNA for the remaining terminal complement factors was present in HUVEC. By the use of reverse transcription (RT)-polymerase chain reaction (PCR) and Northern blot the presence of mRNA for complement factors C5, C6, C8 and C9 was demonstrated
Imputing missing data of function and disease activity in rheumatoid arthritis registers : What is the best technique?
No full textObjective To compare several methods of missing data imputation for function (Health Assessment Questionnaire) and for disease activity (Disease Activity Score-28 and Clinical Disease Activity Index) in rheumatoid arthritis (RA) patients. Methods One thousand RA patients from observational cohort studies with complete data for function and disease activity at baseline, 6, 12 and 24 months were selected to conduct a simulation study. Values were deleted at random or following a predicted attrition bias. Three types of imputation were performed: (1) methods imputing forward in time (last observation carried forward; linear forward extrapolation); (2) methods considering data both forward and backward in time (nearest available observation - NAO; linear extrapolation; polynomial extrapolation); and (3) methods using multi-individual models (linear mixed effects cubic regression - LME3; multiple imputation by chained equation - MICE). The performance of each estimation method was assessed using the difference between the mean outcome value, the remission and low disease activity rates after imputation of the missing values and the true value. Results When imputing missing baseline values, all methods underestimated equally the true value, but LME3 and MICE correctly estimated remission and low disease activity rates. When imputing missing follow-up values at 6, 12, or 24 months, NAO provided the least biassed estimate of the mean disease activity and corresponding remission rate. These results were not affected by the presence of attrition bias. Conclusion When imputing function and disease activity in large registers of active RA patients, researchers can consider the use of a simple method such as NAO for missing follow-up data, and the use of mixed-effects regression or multiple imputation for baseline data
Rheumatoid Arthritis Patients after Initiation of a New Biologic Agent: Trajectories of Disease Activity in a Large Multinational Cohort Study
No full textBackground Response to disease modifying antirheumatic drugs (DMARDs) in rheumatoid arthritis (RA) is often heterogeneous. We aimed to identify types of disease activity trajectories following the initiation of a new biologic DMARD (bDMARD). Methods Pooled analysis of nine national registries of patients with diagnosis of RA, who initiated Abatacept and had at least two measures of disease activity (DAS28). We used growth mixture models to identify groups of patients with similar courses of treatment response, and examined these patients’ characteristics and effectiveness outcomes. Findings We identified three types of treatment response trajectories: ‘gradual responders’ (GR; 3576 patients, 91·7%) had a baseline mean DAS28 of 4·1 and progressive improvement over time; ‘rapid responders’ (RR; 219 patients, 5·6%) had higher baseline DAS28 and rapid improvement in disease activity; ‘inadequate responders’ (IR; 103 patients, 2·6%) had high DAS28 at baseline (5·1) and progressive worsening in disease activity. They were similar in baseline characteristics. Drug discontinuation for ineffectiveness was shorter among inadequate responders (p = 0.03), and EULAR good or moderate responses at 1 year was much higher among ‘rapid responders’ (p < 0.001). Interpretation Clinical information and baseline clinical characteristics do not allow a reliable prediction of which trajectory the patients will follow after bDMARD initiation
Photoproduction of K+ K- Pairs in Ultraperipheral Collisions
No full textK+K- pairs may be produced in photonuclear collisions, either from the decays of photoproduced φ(1020) mesons or directly as nonresonant K+K- pairs. Measurements of K+K- photoproduction probe the couplings between the φ(1020) and charged kaons with photons and nuclear targets. The kaon-proton scattering occurs at energies far above those available elsewhere. We present the first measurement of coherent photoproduction of K+K- pairs on lead ions in ultraperipheral collisions using the ALICE detector, including the first investigation of direct K+K- production. There is significant K+K- production at low transverse momentum, consistent with coherent photoproduction on lead targets. In the mass range 1.1<1.4 GeV/c2 above the φ(1020) resonance, for rapidity |yKK|<0.8 and pT,KK<0.1 GeV/c, the measured coherent photoproduction cross section is dσ/dy=3.37±0.61(stat)±0.15(syst) mb. The center-of-mass energy per nucleon of the photon-nucleus (Pb) system WγPb,n ranges from 33 to 188 GeV, far higher than previous measurements on heavy-nucleus targets. The cross section is larger than expected for φ(1020) photoproduction alone. The mass spectrum is fit to a cocktail consisting of φ(1020) decays, direct K+K- photoproduction, and interference between the two. The confidence regions for the amplitude and relative phase angle for direct K+K- photoproduction are presented
Antibiotic sensitivity screening of Klebsiella spp. and Raoultella spp. isolated from marine bivalve molluscs reveal presence of CTX-M-producing K. pneumoniae
No full textKlebsiella spp. are a major cause of both nosocomial and community acquired infections, with K. pneumoniae being responsible for most human infections. Although Klebsiella spp. are present in a variety of environments, their distribution in the sea and the associated antibiotic resistance is largely unknown. In order to examine prevalence of K. pneumoniae and related species in the marine environment, we sampled 476 batches of marine bivalve molluscs collected along the Norwegian coast. From these samples, K. pneumoniae (n = 78), K. oxytoca (n = 41), K. variicola (n = 33), K. aerogenes (n = 1), Raoultella ornithinolytica (n = 38) and R. planticola (n = 13) were isolated. The number of positive samples increased with higher levels of faecal contamination. We found low prevalence of acquired resistance in all isolates, with seven K. pneumoniae isolates showing resistance to more than one antibiotic class. The complete genome sequence of cefotaxime-resistant K. pneumoniae sensu stricto isolate 2016-1400 was obtained using Oxford Nanopore and Illumina MiSeq based sequencing. The 2016-1400 genome had two contigs, one chromosome of 5,088,943 bp and one plasmid of 191,744 bp and belonged to ST1035. The β-lactamase genes blaCTX-M-3 and blaTEM-1, as well as the heavy metal resistance genes pco, ars and sil were carried on a plasmid highly similar to one found in K. pneumoniae strain C17KP0055 from South-Korea recovered from a blood stream infection. The present study demonstrates that K. pneumoniae are prevalent in the coastal marine environment and that bivalve molluscs may act as a potential reservoir of extended spectrum β-lactamase (ESBL)-producing K. pneumoniae that may be transmitted through the food chain.publishedVersio
Measuring (KSK +/-)-K-0 interactions using Pb-Pb collisions at root S-NN=2.76 TeV
No full textWe present the first ever measurements of femtoscopic correlations between the K-S(0) and K-+/- particles. The analysis was performed on the data from Pb-Pb collisions at root S-NN = 2.76 TeV measured by the ALICE experiment. The observed femtoscopic correlations are consistent with final-state interactions proceeding via the a(0)(980) resonance. The extracted kaon source radius and correlation strength parameters for (KSK-)-K-0 are found to be equal within the experimental uncertainties to those for (KSK+)-K-0. Comparing the results of the present study with those from published identical-kaon femtoscopic studies by ALICE, mass and coupling parameters for the a(0) resonance are tested. Our results are also compatible with the interpretation of the a(0) having a tetraquark structure instead of that of a diquark. (c) 2017 The Author. Published by Elsevier B.V
The Prevalence of Workaholism: A Survey Study in a Nationally Representative Sample of Norwegian Employees
No full textWorkaholism has become an increasingly popular area for empirical study. However, most studies examining the prevalence of workaholism have used non-representative samples and measures with poorly defined cut-off scores. To overcome these methodological limitations, a nationally representative survey among employees in Norway (N = 1,124) was conducted. Questions relating to gender, age, marital status, caretaker responsibility for children, percentage of full-time equivalent, and educational level were asked. Workaholism was assessed by the use of a psychometrically validated instrument (i.e., Bergen Work Addiction Scale). Personality was assessed using the Mini-International Personality Item Pool. Results showed that the prevalence of workaholism was 8.3% (95% CI = 6.7–9.9%). An adjusted logistic regression analysis showed that workaholism was negatively related to age and positively related to the personality dimensions agreeableness, neuroticism, and intellect/imagination. Implications for these findings are discussed
Production of K∗(892)0 and φ(1020) in pp and Pb-Pb collisions at sNN =5.02 TeV
No full textThe production of K *(892)(0) and phi(1020) mesons in proton-proton (pp) and lead-lead (Pb-Pb) collisions at root s(NN) = 5.02 TeV has been measured using the ALICE detector at the Large Hadron Collider (LHC). The transverse momentum (p(T)) distributions of K*(892)(0) and phi(1020) mesons have been measured at midrapidity (vertical bar y vertical bar 8 GeV/c, the R-AA values of K *(892)(0) and phi(1020) are below unity and observed to be similar to those of pions, kaons, and (anti)protons. The R-AA values at high pT (>8 GeV/c) for K*(892)0 and f(1020) mesons are in agreement within uncertainties for root s(NN) = 5.02 and 2.76 TeV
Study of the p–p–K + and p–p–K - dynamics using the femtoscopy technique
No full textThe interactions of kaons (K) and antikaons (K ̄) with few nucleons (N) were studied so far using kaonic atom data and measurements of kaon production and interaction yields in nuclei. Some details of the three-body KNN and K ̄ NN dynamics are still not well understood, mainly due to the overlap with multi-nucleon interactions in nuclei. An alternative method to probe the dynamics of three-body systems with kaons is to study the final state interaction within triplet of particles emitted in pp collisions at the Large Hadron Collider, which are free from effects due to the presence of bound nucleons. This Letter reports the first femtoscopic study of p–p–K + and p–p–K - correlations measured in high-multiplicity pp collisions at s = 13 TeV by the ALICE Collaboration. The analysis shows that the measured p–p–K + and p–p–K - correlation functions can be interpreted in terms of pairwise interactions in the triplets, indicating that the dynamics of such systems is dominated by the two-body interactions without significant contributions from three-body effects or bound states
Constraining the K ¯ N coupled channel dynamics using femtoscopic correlations at the LHC
No full textAbstract The interaction of K - with protons is characterised by the presence of several coupled channels, systems like K ¯ 0 n and \uppi \Sigma π Σ with a similar mass and the same quantum numbers as the K - p state. The strengths of these couplings to the K - p system are of crucial importance for the understanding of the nature of the Λ ( 1405 ) resonance and of the attractive K - p strong interaction. In this article, we present measurements of the K - p correlation functions in relative momentum space obtained in pp collisions at s = 13 Te, in p–Pb collisions at s NN = 5.02 Te, and (semi)peripheral Pb–Pb collisions at s NN = 5.02 Te. The emitting source size, composed of a core radius anchored to the K + p correlation and of a resonance halo specific to each particle pair, varies between 1 and 2 fm in these collision systems. The strength and the effects of the K ¯ 0 n and \uppi \Sigma π Σ inelastic channels on the measured K - p correlation function are investigated in the different colliding systems by comparing the data with state-of-the-art models of chiral potentials. A novel approach to determine the conversion weights ω , necessary to quantify the amount of produced inelastic channels in the correlation function, is presented. In this method, particle yields are estimated from thermal model predictions, and their kinematic distribution from blast-wave fits to measured data. The comparison of chiral potentials to the measured K - p interaction indicates that, while the \uppi \Sigma π Σ – K - p dynamics is well reproduced by the model, the coupling to the K ¯ 0 n channel in the model is currently underestimated
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