1,289 research outputs found

    Design of a Phase 4 Randomized, Double-Blind, Placebo-Controlled Trial Assessing the ImPact of Residual Inflammation Detected via Imaging TEchniques, Drug Levels, and Patient Characteristics on the Outcome of Dose TaperIng of Adalimumab in Clinical Remission Rheumatoid ArThritis (RA) Patients (PREDICTRA)

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    Introduction: The current American College of Rheumatology and European League Against Rheumatism treatment recommendations advise tapering biological disease-modifying antirheumatic drug (bDMARD) therapy in patients with rheumatoid arthritis (RA) who achieve stable clinical remission while receiving bDMARDs. However, not all patients maintain remission or low disease activity after tapering or discontinuation of bDMARDs. The aim of the ImPact of Residual Inflammation Detected via Imaging TEchniques, Drug Levels and Patient Characteristics on the Outcome of Dose TaperIng of Adalimumab in Clinical Remission Rheumatoid ArThritis (RA) study, or PREDICTRA, is to generate data on patient and disease characteristics that may predict the clinical course of a fixed dose-tapering regimen with the bDMARD adalimumab. Methods and analysis: PREDICTRA is an ongoing, multicentre, phase IV, randomised, double-blind, parallel-group study of adalimumab dose tapering controlled by withdrawal in participants with RA who achieved stable clinical remission while receiving adalimumab. The study includes a screening period, a 4-week lead-in period with open-label adalimumab 40 mg every other week and a subsequent 36-week double-blind period during which participants are randomised 5:1 to adalimumab 40 mg every 3 weeks (taper arm) or placebo (withdrawal arm). The primary explanatory efficacy variables are lead-in baseline hand and wrist MRI-detected synovitis and bone marrow oedema scores, as well as a composite of both scores; the dependent variable is the occurrence of flare up to week 40. Additional efficacy variables, safety, pharmacokinetics, biomarkers and immunogenicity will also be assessed, and an ultrasound substudy will be conducted. Ethics and dissemination: The study is conducted in accordance with the International Conference on Harmonisation guidelines, local laws and the ethical principles of the Declaration of Helsinki. All participants are required to sign a written informed consent statement before the start of any study procedures

    Adalimumab dose tapering in patients with rheumatoid arthritis who are in long-standing clinical remission: results of the phase IV PREDICTRA study

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    Objective: To investigate the association between baseline disease activity and the occurrence of flares after adalimumab tapering or withdrawal in patients with rheumatoid arthritis (RA) in sustained remission. Methods: The PREDICTRA phase IV, randomised, double-blind (DB) study (ImPact of Residual Inflammation Detected via Imaging TEchniques, Drug Levels, and Patient Characteristics on the Outcome of Dose TaperIng of Adalimumab in Clinical Remission Rheumatoid ArThritis (RA) Patients) enrolled patients with RA receiving adalimumab 40 mg every other week who were in sustained remission ≥6 months. After a 4-week, open-label lead-in (OL-LI) period, patients were randomised 5:1 to DB adalimumab taper (every 3 weeks) or withdrawal (placebo) for 36 weeks. The primary endpoint was the association between DB baseline hand and wrist MRI-detected inflammation with flare occurrence. Results: Of 146 patients treated during the OL-LI period, 122 were randomised to taper (n=102) or withdrawal (n=20) arms. Patients had a mean 12.9 years of active disease and had received adalimumab for a mean of 5.4 years (mean 2.2 years in sustained remission). Overall, 37 (36%) and 9 (45%) patients experienced a flare in the taper and withdrawal arms, respectively (time to flare, 18.0 and 13.3 weeks). None of the DB baseline disease characteristics or adalimumab concentration was associated with flare occurrence after adalimumab tapering. Approximately half of the patients who flared regained clinical remission after 16 weeks of open-label rescue adalimumab. The safety profile was consistent with previous studies. Conclusions: Approximately one-third of patients who tapered adalimumab versus half who withdrew adalimumab experienced a flare within 36 weeks. Time to flare was numerically longer in the taper versus withdrawal arm. Baseline MRI inflammation was not associated with flare occurrence. Trial registration number: NCT02198651, EudraCT 2014-001114-26

    Re-treatment with abatacept plus methotrexate for disease flare after complete treatment withdrawal in patients with early rheumatoid arthritis: 2-year results from the AVERT study

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    Objectives: To complete reporting of outcomes after total withdrawal of all rheumatoid arthritis (RA) therapy and re-treatment after flare in Assessing Very Early Rheumatoid arthritis Treatment study (NCT01142726). Methods: Patients with early RA were initially randomised to double-blind, weekly subcutaneous abatacept plus methotrexate, or abatacept or methotrexate monotherapy. At month 12, patients with Disease Activity Score (DAS)28 C reactive protein (CRP) <3.2 had all RA treatments rapidly withdrawn and were observed for ≤12 months or until flare. After ≥3 months’ withdrawal, patients with protocol-defined RA flare received open-label abatacept plus methotrexate for 6 months (re-treatment). Results: Proportion of patients in DAS28-CRP–defined remission remained numerically higher in original abatacept plus methotrexate and abatacept arms versus methotrexate arm up to day 253 of withdrawal. At the end of the withdrawal period, few patients remained in remission across all arms: 9/73 (12.3%), 7/50 (14.0%) and 6/53 (11.3%), respectively. For patients entering re-treatment, after 6 months’ re-treatment, 95/124 (76.6%) and 78/124 (62.9%) patients achieved DAS28-CRP <3.2 and <2.6, respectively; mean changes in DAS28-CRP and Health Assessment Questionnaire–Disability Index scores from re-treatment baseline were –2.87 and 0.76, respectively. Re-treatment was well tolerated; exposure-adjusted infection rates per 100 patient-years were lower with abatacept plus methotrexate during withdrawal (7.2) and re-treatment (17.2) versus initial treatment periods of months 0–6 (116.6) and 6–12 (64.6). Conclusions: Most patients flared within 6 months of therapy withdrawal and few sustained major responses for 1 year. Re-treatment with abatacept plus methotrexate was effective and well tolerated in this controlled setting

    Beliefs about the Minds of Others Influence How We Process Sensory Information

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    Attending where others gaze is one of the most fundamental mechanisms of social cognition. The present study is the first to examine the impact of the attribution of mind to others on gaze-guided attentional orienting and its ERP correlates. Using a paradigm in which attention was guided to a location by the gaze of a centrally presented face, we manipulated participants' beliefs about the gazer: gaze behavior was believed to result either from operations of a mind or from a machine. In Experiment 1, beliefs were manipulated by cue identity (human or robot), while in Experiment 2, cue identity (robot) remained identical across conditions and beliefs were manipulated solely via instruction, which was irrelevant to the task. ERP results and behavior showed that participants' attention was guided by gaze only when gaze was believed to be controlled by a human. Specifically, the P1 was more enhanced for validly, relative to invalidly, cued targets only when participants believed the gaze behavior was the result of a mind, rather than of a machine. This shows that sensory gain control can be influenced by higher-order (task-irrelevant) beliefs about the observed scene. We propose a new interdisciplinary model of social attention, which integrates ideas from cognitive and social neuroscience, as well as philosophy in order to provide a framework for understanding a crucial aspect of how humans' beliefs about the observed scene influence sensory processing

    An Investigation into the Cognition Behind Spontaneous String Pulling in New Caledonian Crows

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    The ability of some bird species to pull up meat hung on a string is a famous example of spontaneous animal problem solving. The “insight” hypothesis claims that this complex behaviour is based on cognitive abilities such as mental scenario building and imagination. An operant conditioning account, in contrast, would claim that this spontaneity is due to each action in string pulling being reinforced by the meat moving closer and remaining closer to the bird on the perch. We presented experienced and naïve New Caledonian crows with a novel, visually restricted string-pulling problem that reduced the quality of visual feedback during string pulling. Experienced crows solved this problem with reduced efficiency and increased errors compared to their performance in standard string pulling. Naïve crows either failed or solved the problem by trial and error learning. However, when visual feedback was available via a mirror mounted next to the apparatus, two naïve crows were able to perform at the same level as the experienced group. Our results raise the possibility that spontaneous string pulling in New Caledonian crows may not be based on insight but on operant conditioning mediated by a perceptual-motor feedback cycle

    D-brane potentials in the warped resolved conifold and natural inflation

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    In this paper we obtain a model of Natural Inflation from string theory with a Planckian decay constant. We investigate D-brane dynamics in the background of the warped resolved conifold (WRC) throat approximation of Type IIB string compactifications on Calabi-Yau manifolds. When we glue the throat to a compact bulk Calabi-Yau, we generate a D-brane potential which is a solution to the Laplace equation on the resolved conifold. We can exactly solve this equation, including dependence on the angular coordinates. The solutions are valid down to the tip of the resolved conifold, which is not the case for the more commonly used deformed conifold. This allows us to exploit the effect of the warping, which is strongest at the tip. We inflate near the tip using an angular coordinate of a D5-brane in the WRC which has a discrete shift symmetry, and feels a cosine potential, giving us a model of Natural Inflation, from which it is possible to get a Planckian decay constant whilst maintaining control over the backreaction. This is because the decay constant for a wrapped brane contains powers of the warp factor, and so can be made large, while the wrapping parameter can be kept small enough so that backreaction is under control.Comment: 41 pages, 3 appendices, 1 figure, PDFLaTex; various clarifications added along with a new appendix on b-axions and wrapped D5 branes;version matches the one published in JHE

    Ovine pedomics : the first study of the ovine foot 16S rRNA-based microbiome

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    We report the first study of the bacterial microbiome of ovine interdigital skin based on 16S rRNA by pyrosequencing and conventional cloning with Sanger-sequencing. Three flocks were selected, one a flock with no signs of footrot or interdigital dermatitis, a second flock with interdigital dermatitis alone and a third flock with both interdigital dermatitis and footrot. The sheep were classified as having either healthy interdigital skin (H), interdigital dermatitis (ID) or virulent footrot (VFR). The ovine interdigital skin bacterial community varied significantly by flock and clinical condition. The diversity and richness of operational taxonomic units was greater in tissue from sheep with ID than H or VFR affected sheep. Actinobacteria, Bacteriodetes, Firmicutes and Proteobacteria were the most abundant phyla comprising 25 genera. Peptostreptococcus, Corynebacterium and Staphylococcus were associated with H, ID and VFR respectively. Sequences of Dichelobacter nodosus, the causal agent of ovine footrot, were not amplified due to mismatches in the 16S rRNA universal forward primer (27F). A specific real time PCR assay was used to demonstrate the presence of D. nodosus which was detected in all samples including the flock with no signs of ID or VFR. Sheep with ID had significantly higher numbers of D. nodosus (104-109 cells/g tissue) than those with H or VFR feet

    Tool-Use Training in a Species of Rodent: The Emergence of an Optimal Motor Strategy and Functional Understanding

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    Tool use is defined as the manipulation of an inanimate object to change the position or form of a separate object. The expansion of cognitive niches and tool-use capabilities probably stimulated each other in hominid evolution. To understand the causes of cognitive expansion in humans, we need to know the behavioral and neural basis of tool use. Although a wide range of animals exhibit tool use in nature, most studies have focused on primates and birds on behavioral or psychological levels and did not directly address questions of which neural modifications contributed to the emergence of tool use. To investigate such questions, an animal model suitable for cellular and molecular manipulations is needed.) to use a rake-like tool with their forelimbs to retrieve otherwise out-of-reach rewards. Eventually, they mastered effective use of the tool, moving it in an elegant trajectory. After the degus were well trained, probe tests that examined whether they showed functional understanding of the tool were performed. Degus did not hesitate to use tools of different size, colors, and shapes, but were reluctant to use the tool with a raised nonfunctional blade. Thus, degus understood the functional and physical properties of the tool after extensive training.Our findings suggest that tool use is not a specific faculty resulting from higher intelligence, but is a specific combination of more general cognitive faculties. Studying the brains and behaviors of trained rodents can provide insights into how higher cognitive functions might be broken down into more general faculties, and also what cellular and molecular mechanisms are involved in the emergence of such cognitive functions

    New Caledonian crows rapidly solve a collaborative problem without cooperative cognition

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    There is growing comparative evidence that the cognitive bases of cooperation are not unique to humans. However, the selective pressures that lead to the evolution of these mechanisms remain unclear. Here we show that while tool-making New Caledonian crows can produce collaborative behavior, they do not understand the causality of cooperation nor show sensitivity to inequity. Instead, the collaborative behavior produced appears to have been underpinned by the transfer of prior experience. These results suggest that a number of possible selective pressures, including tool manufacture and mobbing behaviours, have not led to the evolution of cooperative cognition in this species. They show that causal cognition can evolve in a domain specific manner-understanding the properties and flexible uses of physical tools does not necessarily enable animals to grasp that a conspecific can be used as a social tool

    Gaze following in multiagent contexts: Evidence for a quorum-like principle

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    Research shows that humans spontaneously follow another individual’s gaze. However, little remains known on how they respond when multiple gaze cues diverge across members of a social group. To address this question, we presented participants with displays depicting three (Experiment 1) or five (Experiment 2) agents showing diverging social cues. In a three-person group, one individual looking at the target (33% of the group) was sufficient to elicit gaze-facilitated target responses. With a five-person group, however, three individuals looking at the target (60% of the group) were necessary to produce the same effect. Gaze following in small groups therefore appears to be based on a quorum-like principle, whereby the critical level of social information needed for gaze following is determined by a proportion of consistent social cues scaled as a function of group size. As group size grows, greater agreement is needed to evoke joint attention
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