174 research outputs found

    Eta and Etaprime Photoproduction on the Nucleon with the Isobar Model EtaMAID2018

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    The isobar model EtaMAID has been updated with new and high precision data for eta and etaprime photoproduction on protons and neutrons from MAMI, ELSA, GRAAL and CLAS. The background is described in a recently developed Regge-cut model, and for the resonance part the whole list of nucleon resonances has been investigated with 21 N* states contributing to eta photoproduction and 12 N* states contributing to etaprime photoproduction. A new approach is discussed to avoid double counting in the overlap region of Regge and resonances. A comparison is done among four newly updated partial waves analyses for observables and partial waves. Finally, the possibility of a narrow resonance near W=1900 MeV is discussed, that would be able to explain unexpected energy and angular dependence of observables in p(gamma,etaprime)p near etaprime threshold.Comment: 31 pages, 29 figures, replaced with revised versio

    Antibodies to infliximab and adalimumab in patients with rheumatoid arthritis in clinical remission:a cross-sectional study

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    Objective. To investigate if antibodies towards biological TNF-α inhibitors (anti-TNFi Abs) are present in patients with rheumatoid arthritis (RA) in clinical remission and to relate any anti-TNFi Abs to circulating level of TNF-α inhibitor (TNFi). Methods. Patients with RA, treated with infliximab or adalimumab, and in clinical remission (DAS28(CRP) < 2.6) were included from 6 out-patient clinics. In blood samples, presence of anti-TNFi Abs was determined by radioimmunoassay, and concentration of bioactive TNFi was measured by a cell-based reporter gene assay. Results. Anti-TNFi Abs were present in 8/44 patients (18%) treated with infliximab and 1/49 patients (2%) treated with adalimumab (p=0.012). In the former group, anti-TNFi Abs corresponded with low levels of TNFi (p=0.048). Anti-TNFi Ab-positive patients had shorter disease duration at initiation of TNFi therapy (p=0.023) but were similar for the rest of the compared parameters. Conclusions. In RA patients in clinical remission, anti-TNFi Abs occur frequently in patients treated with infliximab, while they occur rarely in patients treated with adalimumab. Presence of anti-infliximab Abs is accompanied by low or undetectable levels of infliximab. These data suggest that continued infliximab treatment may be redundant in a proportion of RA patients treated with infliximab and in clinical remission

    Impact of different infliximab dose regimens on treatment response and drug survival in 462 patients with psoriatic arthritis: results from the nationwide registries DANBIO and ICEBIO.

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.The aim of this study was to describe dose regimens, dose escalation and clinical outcomes in TNF-α inhibitor (TNFi)-naive patients with PsA treated with infliximab in routine rheumatology care.We conducted an observational cohort study based on the nationwide Danish Rheumatologic Database (DANBIO) and Center for Rheumatology Research (ICEBIO) registries. Stratified by country, characteristics of patients treated with ≤3 mg infliximab/kg body weight, 3-5 mg/kg or ≥5 mg/kg every 8 weeks were described. Outcomes were evaluated by ACR 20%, 50% and 70% (ACR20/50/70) responses and European League Against Rheumatism good response after 6 months, disease activity after 12 months, Kaplan-Meier plots and regression analyses.Four hundred and sixty-two patients (376 Danish, 86 Icelandic) received treatment with infliximab. In Danish patients, the starting dose was ≤3 mg/kg in 110 patients (29%), 3-5 mg/kg in 157 (42%), ≥5 mg/kg in 38 (10%) and unregistered in 71 (19%). In Icelandic patients, corresponding numbers were 64 (74%), 17 (27%), 0 (0%) and 5 (6%). Patients with a higher body weight received lower doses per kilogram. Danish patients received higher doses than Icelandic patients at baseline [median 3.1 (interquartile range 3.0-3.8) vs 2.3 (2.1-2.9) mg/kg, P 70% of Icelandic and Danish PsA patients treated with infliximab received sustained doses below the 5 mg/kg every 8 weeks recommended in international guidelines. Lower starting doses did not affect drug survival or response

    Instantaneous wave-free ratio compared with fractional flow reserve in PCI: A cost-minimization analysis.

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadBackground: Coronary physiology is a routine diagnostic tool when assessing whether coronary revascularization is indicated. The iFR-SWEDEHEART trial demonstrated similar clinical outcomes when using instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) to guide revascularization. The objective of this analysis was to assess a cost-minimization analysis of iFR-guided compared with FFR-guided revascularization. Methods: In this cost-minimization analysis we used a decision-tree model from a healthcare perspective with a time-horizon of one year to estimate the cost difference between iFR and FFR in a Nordic setting and a United States (US) setting. Treatment pathways and health care utilizations were constructed from the iFR-SWEDEHEART trial. Unit cost for revascularization and myocardial infarction in the Nordic setting and US setting were derived from the Nordic diagnosis-related group versus Medicare cost data. Unit cost of intravenous adenosine administration and cost per stent placed were based on the average costs from the enrolled centers in the iFR-SWEDEHEART trial. Deterministic and probabilistic sensitivity analyses were carried out to test the robustness of the result. Results: The cost-minimization analysis demonstrated a cost saving per patient of 681(95681 (95% CI: 641 - 723)intheNordicsettingand723) in the Nordic setting and 1024 (95% CI: 934934 - 1114) in the US setting, when using iFR-guided compared with FFR-guided revascularization. The results were not sensitive to changes in uncertain parameters or assumptions. Conclusions: IFR-guided revascularization is associated with significant savings in cost compared with FFR-guided revascularization. Keywords: Cost-minimization analysis; Fractional flow reserve; Instantaneous wave-free ratio.Philips Volcan

    The Distinct Conformational Dynamics of K-Ras and H-Ras A59G

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    Ras proteins regulate signaling cascades crucial for cell proliferation and differentiation by switching between GTP- and GDP-bound conformations. Distinct Ras isoforms have unique physiological functions with individual isoforms associated with different cancers and developmental diseases. Given the small structural differences among isoforms and mutants, it is currently unclear how these functional differences and aberrant properties arise. Here we investigate whether the subtle differences among isoforms and mutants are associated with detectable dynamical differences. Extensive molecular dynamics simulations reveal that wild-type K-Ras and mutant H-Ras A59G are intrinsically more dynamic than wild-type H-Ras. The crucial switch 1 and switch 2 regions along with loop 3, helix 3, and loop 7 contribute to this enhanced flexibility. Removing the gamma-phosphate of the bound GTP from the structure of A59G led to a spontaneous GTP-to-GDP conformational transition in a 20-ns unbiased simulation. The switch 1 and 2 regions exhibit enhanced flexibility and correlated motion when compared to non-transitioning wild-type H-Ras over a similar timeframe. Correlated motions between loop 3 and helix 5 of wild-type H-Ras are absent in the mutant A59G reflecting the enhanced dynamics of the loop 3 region. Taken together with earlier findings, these results suggest the existence of a lower energetic barrier between GTP and GDP states of the mutant. Molecular dynamics simulations combined with principal component analysis of available Ras crystallographic structures can be used to discriminate ligand- and sequence-based dynamic perturbations with potential functional implications. Furthermore, the identification of specific conformations associated with distinct Ras isoforms and mutants provides useful information for efforts that attempt to selectively interfere with the aberrant functions of these species

    Both the C-Terminal Polylysine Region and the Farnesylation of K-RasB Are Important for Its Specific Interaction with Calmodulin

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    Background: Ras protein, as one of intracellular signal switches, plays various roles in several cell activities such as differentiation and proliferation. There is considerable evidence showing that calmodulin (CaM) binds to K-RasB and dissociates K-RasB from membrane and that the inactivation of CaM is able to induce K-RasB activation. However, the mechanism for the interaction of CaM with K-RasB is not well understood. Methodology/Principal Findings: Here, by applying fluorescence spectroscopy and isothermal titration calorimetry, we have obtained thermodynamic parameters for the interaction between these two proteins and identified the important elements of K-RasB for its interaction with Ca 2+ /CaM. One K-RasB molecule interacts with one CaM molecule in a GTP dependent manner with moderate, micromolar affinity at physiological pH and physiologic ionic strength. Mutation in the polybasic domain of K-Ras decreases the binding affinity. By using a chimera in which the C-terminal polylysine region of K-RasB has been replaced with that of H-Ras and vice versa, we find that at physiological pH, H-Ras-(KKKKKK) and Ca 2+ /CaM formed a 1:1 complex with an equilibrium association constant around 10 5 M 21, whereas no binding reaction of K-RasB-(DESGPC) with Ca 2+ /CaM is detected. Furthermore, the interaction of K-RasB with Ca 2+ /CaM is found to be enhanced by the farnesylation of K-RasB. Conclusions/Significance: We demonstrate that the polylysine region of K-RasB not only contributes importantly to th
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