1,555 research outputs found

    Monocyte Subset Recruitment Marker Profile Is Inversely Associated With Blood ApoA1 Levels.

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    Dyslipidemia promotes development of the atherosclerotic plaques that characterise cardiovascular disease. Plaque progression requires the influx of monocytes into the vessel wall, but whether dyslipidemia is associated with an increased potential of monocytes to extravasate is largely unknown. Here (using flow cytometry) we examined recruitment marker expression on monocytes from generally healthy individuals who differed in lipid profile. Comparisons were made between monocyte subsets, participants and relative to participants' lipid levels. Monocyte subsets differed significantly in their expression of recruitment markers, with highest expression being on either the classical or non-classical subsets. However, these inter-subset differences were largely overshadowed by considerable inter-participant differences with some participants having higher levels of recruitment markers on all three monocyte subsets. Furthermore, when the expression of one recruitment marker was high, so too was that of most of the other markers, with substantial correlations evident between the markers. The inter-participant differences were explained by lipid levels. Most notably, there was a significant inverse correlation for most markers with ApoA1 levels. Our results indicate that dyslipidemia, in particular low levels of ApoA1, is associated with an increased potential of all monocyte subsets to extravasate, and to do so using a wider repertoire of recruitment markers than currently appreciated

    Best practice for analysis of shared clinical trial data

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    BACKGROUND: Greater transparency, including sharing of patient-level data for further research, is an increasingly important topic for organisations who sponsor, fund and conduct clinical trials. This is a major paradigm shift with the aim of maximising the value of patient-level data from clinical trials for the benefit of future patients and society. We consider the analysis of shared clinical trial data in three broad categories: (1) reanalysis - further investigation of the efficacy and safety of the randomized 3 intervention, (2) meta-analysis, and (3) supplemental analysis for a research question that is not directly assessing the randomized intervention. DISCUSSION: In order to support appropriate interpretation and limit the risk of misleading findings, analysis of shared clinical trial data should have a pre-specified analysis plan. However, it is not generally possible to limit bias and control multiplicity to the extent that is possible in the original trial design, conduct and analysis, and this should be acknowledged and taken into account when interpreting results. We highlight a number of areas where specific considerations arise in planning, conducting, interpreting and reporting analyses of shared clinical trial data. A key issue is that that these analyses essentially share many of the limitations of any post hoc analyses beyond the original specified analyses. The use of individual patient data in meta-analysis can provide increased precision and reduce bias. Supplemental analyses are subject to many of the same issues that arise in broader epidemiological analyses. Specific discussion topics are addressed within each of these areas. SUMMARY: Increased provision of patient-level data from industry and academic-led clinical trials for secondary research can benefit future patients and society. Responsible data sharing, including transparency of the research objectives, analysis plans and of the results will support appropriate interpretation and help to address the risk of misleading results and avoid unfounded health scares

    Boosting BCG with recombinant modified vaccinia ankara expressing antigen 85A: Different boosting intervals and implications for efficacy trials

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    Objectives. To investigate the safety and immunogenicity of boosting BCG with modified vaccinia Ankara expressing antigen 85A (MVA85A), shortly after BCG vaccination, and to compare this first with the immunogenicity of BCG vaccination alone and second with a previous clinical trial where MVA85A was administered more than 10 years after BCG vaccination. Design. There are two clinical trials reported here: a Phase I observational trial with MVA85A; and a Phase IV observational trial with BCG. These clinical trials were all conducted in the UK in healthy, HIV negative, BCG naı¨ve adults. Subjects were vaccinated with BCG alone; or BCG and then subsequently boosted with MVA85A four weeks later (short interval). The outcome measures, safety and immunogenicity, were monitored for six months. The immunogenicity results from this short interval BCG prime–MVA85A boost trial were compared first with the BCG alone trial and second with a previous clinical trial where MVA85A vaccination was administered many years after vaccination with BCG. Results. MVA85A was safe and highly immunogenic when administered to subjects who had recently received BCG vaccination. When the short interval trial data presented here were compared with the previous long interval trial data, there were no significant differences in the magnitude of immune responses generated when MVA85A was administered shortly after, or many years after BCG vaccination. Conclusions. The clinical trial data presented here provides further evidence of the ability of MVA85A to boost BCG primed immune responses. This boosting potential is not influenced by the time interval between prior BCG vaccination and boosting with MVA85A. These findings have important implications for the design of efficacy trials with MVA85A. Boosting BCG induced anti-mycobacterial immunity in either infancy or adolescence are both potential applications for this vaccine, given the immunological data presented here. Trial Registration. ClinicalTrials.Oxford University was the sponsor for all the clinical trials reported here

    How Do Bacteria Know They Are on a Surface and Regulate Their Response to an Adhering State?

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    Bacteria adhere to virtually all natural and synthetic surfaces [1,2]. Although there are a number of different reasons as to why bacteria adhere to a surface, the summarizing answer is brief: ‘‘Adhesion to a surface is a survival mechanism for bacteria’’. Nutrients in aqueous environments have the tendency to accumulate at surfaces [1,3], giving adhering bacteria a benefit over free floating, so-called planktonic ones. This is why mountain creeks may contain crystal clear, drinkable water, while stepping stones underneath the water may be covered with a slippery film of adhering microbes. In the oral cavity, adhesion to dental hard and soft tissues is life-saving to the organisms, because microbes that do not manage to adhere and remain planktonic in saliva are swallowed with an almost certain death in the gastrointestinal tract. Bacterial adhesion is generally recognized as the first step in biofilm formation, and for the human host, the ability of

    Macrophage Subset Sensitivity to Endotoxin Tolerisation by Porphyromonas gingivalis

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    Macrophages (MΦs) determine oral mucosal responses; mediating tolerance to commensal microbes and food whilst maintaining the capacity to activate immune defences to pathogens. MΦ responses are determined by both differentiation and activation stimuli, giving rise to two distinct subsets; pro-inflammatory M1- and anti-inflammatory/regulatory M2- MΦs. M2-like subsets predominate tolerance induction whereas M1 MΦs predominate in inflammatory pathologies, mediating destructive inflammatory mechanisms, such as those in chronic P.gingivalis (PG) periodontal infection. MΦ responses can be suppressed to benefit either the host or the pathogen. Chronic stimulation by bacterial pathogen associated molecular patterns (PAMPs), such as LPS, is well established to induce tolerance. The aim of this study was to investigate the susceptibility of MΦ subsets to suppression by P. gingivalis. CD14hi and CD14lo M1- and M2-like MΦs were generated in vitro from the THP-1 monocyte cell line by differentiation with PMA and vitamin D3, respectively. MΦ subsets were pre-treated with heat-killed PG (HKPG) and PG-LPS prior to stimulation by bacterial PAMPs. Modulation of inflammation was measured by TNFα, IL-1β, IL-6, IL-10 ELISA and NFκB activation by reporter gene assay. HKPG and PG-LPS differentially suppress PAMP-induced TNFα, IL-6 and IL-10 but fail to suppress IL-1β expression in M1 and M2 MΦs. In addition, P.gingivalis suppressed NFκB activation in CD14lo and CD14hi M2 regulatory MΦs and CD14lo M1 MΦs whereas CD14hi M1 pro-inflammatory MΦs were refractory to suppression. In conclusion, P.gingivalis selectively tolerises regulatory M2 MΦs with little effect on pro-inflammatory CD14hi M1 MΦs; differential suppression facilitating immunopathology at the expense of immunity

    Neuropsychological assessment of attention in children with spina bifida

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    <p>Abstract</p> <p>Background</p> <p>Children with the severe form of spina bifida (SBM: spina bifida with myelomeningocele with accompanying hydrocephalus) may manifest attention deficits, and have a similar psychological profile to children with hydrocephalus due to other etiologies. It is unclear to what extent tests to assess attention in SBM are confounded by the accompanying cognitive or visual-motor impairments. The aim of this study was to analyse attention functions by administering two different types of attention tests, one with high and the other with low cognitive and motor requirements. This enabled the possible interaction between attention and cognitive and motor impairment to be assessed.</p> <p>Methods</p> <p>The study group comprised 31 children with SBM with shunted hydrocephalus. Twenty children with SB-only formed a closely matched comparison group. Of these, 19 children with SBM and 18 with SB had a full-scale IQ (FSIQ) higher than 70. All had undergone spinal surgery and all children with SBM had been shunted within the first months of life. Between 6 and 15 years of age, the children were assessed on focused and sustained attention, encoding, and distractibility/impulsivity, using both traditional tests and computerized attention tests.</p> <p>Results</p> <p>Compared to the SB group, attention scores of children with SBM were lower on the traditional tests, but when interfering cognitive and visual-motor requirements were eliminated using the computerised tasks, most differences disappeared. Furthermore, in contrast to traditional attention tasks, computerized tests showed no significant correlations with IQ-scores and visual-motor skills.</p> <p>Conclusion</p> <p>Assessment of attention functions in children with SBM by traditional tests may be misleading, because this paediatric population with complex cerebral malformations has difficulty with the cognitive and visual-motor requirements. To control for these interactions, the use of both traditional and computerized attention tests is recommended.</p

    Chaste: an open source C++ library for computational physiology and biology

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    Chaste - Cancer, Heart And Soft Tissue Environment - is an open source C++ library for the computational simulation of mathematical models developed for physiology and biology. Code development has been driven by two initial applications: cardiac electrophysiology and cancer development. A large number of cardiac electrophysiology studies have been enabled and performed, including high performance computational investigations of defibrillation on realistic human cardiac geometries. New models for the initiation and growth of tumours have been developed. In particular, cell-based simulations have provided novel insight into the role of stem cells in the colorectal crypt. Chaste is constantly evolving and is now being applied to a far wider range of problems. The code provides modules for handling common scientific computing components, such as meshes and solvers for ordinary and partial differential equations (ODEs/PDEs). Re-use of these components avoids the need for researchers to "re-invent the wheel" with each new project, accelerating the rate of progress in new applications. Chaste is developed using industrially-derived techniques, in particular test-driven development, to ensure code quality, re-use and reliability. In this article we provide examples that illustrate the types of problems Chaste can be used to solve, which can be run on a desktop computer. We highlight some scientific studies that have used or are using Chaste, and the insights they have provided. The source code, both for specific releases and the development version, is available to download under an open source Berkeley Software Distribution (BSD) licence at http://www.cs.ox.ac.uk/chaste, together with details of a mailing list and links to documentation and tutorials

    FIP1L1-PDGFRA molecular analysis in the differential diagnosis of eosinophilia

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    <p>Abstract</p> <p>Background</p> <p>Primary eosinophlia associated with the <it>FIP1L1-PDGFRA </it>rearrangement represents a subset of chronic eosinophilic leukaemia (CEL) and affected patients are very sensitive to imatinib treatment. This study was undertaken in order to examine the prevalence and the associated clinicopathologic and genetic features of <it>FIP1L1-PDGFRA </it>rearrangement in a cohort of 15 adult patients presenting with profound eosinophilia (> 1.5 × 10<sup>9</sup>/L).</p> <p>Methods</p> <p>Reverse transcriptase-polymerase chain reaction (RT-PCR) was used for the detection of <it>FIP1L1-PDGFRA </it>rearrangement and the results confirmed by direct sequencing. <it>C-KIT</it>-D816V mutation was analysed retrospectively by PCR and restriction-fragment-length-polymorphism (PCR-RFLP), in all cases with primary eosinophilia.</p> <p>Results</p> <p>Two male patients with splenomegaly carried the <it>FIP1L1-PDGFRA </it>rearrangement, whilst 2 others were ultimately classified as suffering from idiopathic hypereosinophlic syndrome (HES) and one from systemic mastocytosis. These patients were negative for the <it>C-KIT</it>-D816V mutation and received imatinib (100–400 mg daily). Patients with CEL and HES responded to imatinib and remained in complete haematological, clinical and molecular (for carriers of <it>FIP1L1-PDGFRA </it>rearrangement) remission for a median of 28.2 months (range: 11–54), whilst the patient with systemic mastocytosis did not respond. Interestingly, in both patients with <it>FIP1L1-PDGFRA </it>rearrangement, the breakpoints into <it>PDGFRA </it>were located within exon 12 and fused with exons 8 and 8a of <it>FIP1L1</it>, respectively.</p> <p>Conclusion</p> <p>An early diagnosis of <it>FIPIL1-PDGFRA</it>-positive CEL and imatinib treatment offer to the affected patients an excellent clinical therapeutic result, avoiding undesirable morbidity. Moreover, although the molecular mechanisms underlying disease pathogenesis remain to be determined, imatinib can be effective in patients with idiopathic HES.</p

    First-Person Perspective Effects on Theory of Mind without Self-Reference

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    This study examined dissociations between brain networks involved in theory of mind, which is needed for guessing others' mental states, and the self, which might constitute the basis for theory of mind's development. We used event-related fMRI to compare a condition that required participants to guess the mental state of a subject featured in first-person perspective sentences (1stPP condition) with a third-person perspective sentence condition (3rdPP condition). The caudate nucleus was marginally more activated in the 1stPP than in the 3rdPP condition, while the left dorsolateral prefrontal cortex (DLPFC) was significantly more activated in the 3rdPP condition as compared to the 1stPP condition. Furthermore, we examined the correlation between activation (signal intensity) of the caudate nucleus and left DLPFC with that of the right DLPFC, which is thought to be closely connected with sense of self. We found a significant correlation between caudate nucleus and right DLPFC activation in the 1stPP condition, and between left and right DLPFC activation in the 3rdPP condition. Although theory of mind and the self both appear to recruit the right DLPFC, this region seems to be accessed through the left DLPFC during theory of mind tasks, but through the caudate nucleus when tasks require self reference
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