41 research outputs found

    Molecular detection of Grapevine fleck virus-like viruses

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    Molecular reagents have been developed for virus-specific and simultaneous (virus-non-specific) detection of Grapevine fleck virus (GFkV) and allied viruses, ie. Grapevine asteroid mosaic-associated virus (GAMaV) and Grapevine red globe virus (GRGV). Degenerate primers designed on nucleotide sequences of the RNA-dependent RNA polymerase (RD) and methyltransferase (MTR) domains of the GFkV genome, were able to give amplification products of the expected size from total nucleic acid extracts of:vines infected with GFkV, GAMaV, and GRGV;a Californian grapevine accession infected by a marafi-like virus;Greek grapevine accessions infected by an unidentified agent that induced symptoms reminiscent of those elicited by GAMaV in Vitis rupestris.Degenerate primers designed on the nucleotide sequence of the helicase (HEL) domain of the GFLV genome recognized all the above viruses except for GAMaV and the unidentified Greek viral agent. RD primer set worked well also with crude grapevine cortical scrapings, thus constituting a useful universal reagent for the non-specific molecular identification of GFkV-like viruses in Vitis . The marafi-like virus from California was amplified by all sets of primers, but was recognized only by the GRGV-specific probe, suggesting that it is a likely isolate of GRGV: Likewise, the unidentified virus from Greek vines shared sequence homology with GFkV and allied viruses (GAMaV and GRGV) but exhibited differences relevant enough that call for further investigations to establish its taxonomic position. While GRGV was identified, though with a very low incidence, in some 11 southern Italian grapevine cultivars, no evidence was obtained for infection by GAMaV in any of 50 cultivars analyzed.

    Preterm Delivery Disrupts the Developmental Program of the Cerebellum

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    A rapid growth in human cerebellar development occurs in the third trimester, which is impeded by preterm delivery. The goal of this study was to characterize the impact of preterm delivery on the developmental program of the human cerebellum. Still born infants, which meant that all development up to that age had taken place in-utero, were age paired with preterm delivery infants, who had survived in an ex-utero environment, which meant that their development had also taken place outside the uterus. The two groups were assessed on quantitative measures that included molecular markers of granule neuron, purkinje neuron and bergmann glia differentiation, as well as the expression of the sonic hedgehog signaling pathway, that is important for cerebellar growth. We report that premature birth and development in an ex-utero environment leads to a significant decrease in the thickness and an increase in the packing density of the cells within the external granular layer and the inner granular layer well, as a reduction in the density of bergmann glial fibres. In addition, this also leads to a reduced expression of sonic hedgehog in the purkinje layer. We conclude that the developmental program of the cerebellum is specifically modified by events that follow preterm delivery

    Identification of the allosteric P2X7 receptor antagonist [11C]SMW139 as a PET tracer of microglial activation

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    The P2X7 receptor plays a significant role in microglial activation, and as a potential drug target, the P2X7 receptor is also an interesting target in positron emission tomography. The current study aimed at the development and evaluation of a potent tracer targeting the P2X7 receptor, to which end four adamantanyl benzamide analogues with high affinity for the human P2X7 receptor were labelled with carbon-11. All four analogues could be obtained in excellent radiochemical yield and high radiochemical purity and molar activity, and all analogues entered the rat brain. [11C]SMW139 showed the highest metabolic stability in rat plasma, and showed high binding to the hP2X7 receptor in vivo in a hP2X7 receptor overexpressing rat model. Although no significant difference in binding of [11C]SMW139 was observed between post mortem brain tissue of Alzheimer's disease patients and that of healthy controls in in vitro autoradiography experiments, [11C]SMW139 could be a promising tracer for P2X7 receptor imaging using positron emission tomography, due to high receptor binding in vivo in the hP2X7 receptor overexpressing rat model. However, further investigation of both P2X7 receptor expression and binding of [11C]SMW139 in other neurological diseases involving microglial activation is warranted

    Identification of new molecular targets for PET imaging of the microglial anti-inflammatory activation state

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    Microglia are potential targets for therapeutic intervention in neurological and neurodegenerative diseases affecting the central nervous system. In order to assess the efficacy of therapies aimed to reduce the tissue damaging activities of microglia and/or to promote the protective potential of these cells, suitable pre-clinical and clinical tools for the in vivo analysis of microglia activities and dynamics are required. The aim of this work was to identify new translational markers of the anti-inflammatory / protective state of microglia for the development of novel PET tracers. Methods: New translational markers of the anti-inflammatory/protective activation state of microglia were selected by bioinformatic approaches and were in vitro and ex vivo validated by qPCR and immunohistochemistry in rodent and human samples. Once a viable marker was identified, a novel PET tracer was developed. This tracer was subsequently confirmed by autoradiography experiments in murine and human brain tissues. Results: Here we provide evidence that P2RY12 expression increases in murine and human microglia following exposure to anti-inflammatory stimuli, and that its expression is modulated in the reparative phase of experimental and clinical stroke. We then synthesized a novel carbon-11 labeled tracer targeting P2RY12, showing increased binding in brain sections of mice treated with IL4, and low binding to brain sections of a murine stroke model and of a stroke patient. Conclusion: This study provides new translational targets for PET tracers for the anti-inflammatory/protective activation state of microglia and shows the potential of a rationale-based approach. It therefore paves the way for the development of novel non-invasive methodologies aimed to monitor the success of therapeutic approaches in various neurological diseases

    A trajectories of behavior, attention, social and emotional problems from childhood to early adulthood following extremely preterm birth: a prospective cohort study

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    © 2018, The Author(s). To investigate trajectories of behavior, attention, social and emotional problems to early adulthood in extremely preterm survivors compared to a term-born comparison group. Longitudinal analysis of a prospective, population-based cohort of 315 surviving infants born < 26 completed weeks of gestation recruited at birth in 1995, from the UK/Republic of Ireland, and a term-born comparison group recruited at age 6. The parent-report Strengths and Difficulties Questionnaire was completed at age 6, 11, 16 and 19 years. The Total Behavioral Difficulties Score was 4.81 points higher in extremely preterm individuals compared to their term-born peers over the period (95% CI 3.76–5.87, p < 0.001) and trajectories were stable in both groups. The impact of difficulties on home life, friendships, school or work and/or leisure activities was greater in the EPT group (RR 4.28, 95% CI 2.89–6.35, p < 0.001), and hyperactivity/inattention and peer problems accounted for the largest differences. A clinically significant behavioral screen at age 2.5 was associated with a higher Total Behavioral Difficulties Score from 6 years onwards in extremely preterm participants (Mean difference 6.90, 95% CI 5.01–8.70, p < 0.0.01), as was moderate/severe cognitive impairment at last assessment (Mean difference: 4.27, 95% CI 2.76–5.77, p < 0.001). Attention, social and emotional problems in extremely preterm individuals persist into early adulthood with significant impact on daily life. A positive behavioral screen in infancy and moderate/severe cognitive impairment are associated with early adult outcomes.NIHR Doctoral Research Fellowship, NIHRDRF-2012-05-206. The EPICure Study was funded by a Medical Research Council Programme Grant to NM (Ref no: MR/J01107X/1

    Positron Emission Tomography Imaging of Macaques with Tuberculosis Identifies Temporal Changes in Granuloma Glucose Metabolism and Integrin α4β1-Expressing Immune Cells

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    Positron emission tomography and computed tomography imaging (PET/CT) is an increasingly valuable tool for diagnosing tuberculosis (TB). The glucose analog [18F]fluoro-2-deoxy-2-d-glucose ([18F]-FDG) is commonly used in PET/CT that is retained by metabolically active inflammatory cells in granulomas, but lacks specificity for particular cell types. A PET probe that could identify recruitment and differentiation of different cell populations in granulomas would be a useful research tool and could improve TB diagnosis and treatment. We used the Mycobacterium-antigen murine inflammation model and macaques with TB to identify [64Cu]-labeled CB-TE1A1P-PEG4-LLP2A ([64Cu]-LLP2A), a high affinity peptidomimetic ligand for very late Ag-4 (VLA-4; also called integrin α4β1) binding cells in granulomas, and compared [64Cu]-LLP2A with [18F]-FDG over the course of infection. We found that [64Cu]-LLP2A retention was driven by macrophages and T cells, with less contribution from neutrophils and B cells. In macaques, granulomas had higher [64Cu]-LLP2A uptake than uninfected tissues, and immunohistochemical analysis of granulomas with known [64Cu]-LLP2A uptake identified significant correlations between LLP2A signal and macrophage and T cell numbers. The same cells coexpressed integrin α4 and β1, further supporting that macrophages and T cells drive [64Cu]-LLP2A avidity in granulomas. Over the course of infection, granulomas and thoracic lymph nodes experienced dynamic changes in affinity for both probes, suggesting metabolic changes and cell differentiation or recruitment occurs throughout granuloma development. These results indicate [64Cu]-LLP2A is a PET probe for VLA-4, which when used in conjunction with [18F]-FDG, may be a useful tool for understanding granuloma biology in TB
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