20 research outputs found

    Functional and Molecular Characterization of Mechanoinsensitive "Silent" Nociceptors.

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    Mechanical and thermal hyperalgesia (pain hypersensitivity) are cardinal signs of inflammation. Although the mechanism underlying thermal hyperalgesia is well understood, the cellular and molecular basis of mechanical hyperalgesia is poorly described. Here, we have identified a subset of peptidergic C-fiber nociceptors that are insensitive to noxious mechanical stimuli under normal conditions but become sensitized to such stimuli when exposed to the inflammatory mediator nerve growth factor (NGF). Strikingly, NGF did not affect mechanosensitivity of other nociceptors. We show that these mechanoinsensitive "silent" nociceptors are characterized by the expression of the nicotinic acetylcholine receptor subunit alpha-3 (CHRNA3) and that the mechanically gated ion channel PIEZO2 mediates NGF-induced mechanosensitivity in these neurons. Retrograde tracing revealed that CHRNA3+ nociceptors account for ∼50% of all peptidergic nociceptive afferents innervating visceral organs and deep somatic tissues. Hence, our data suggest that NGF-induced "un-silencing" of CHRNA3+ nociceptors significantly contributes to the development of mechanical hyperalgesia during inflammation

    Non-conventional forms of HLA-B27 are expressed in spondyloarthritis joints and gut tissue

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    AbstractObjectivesHuman leukocyte antigen (HLA)-B27 (B27) is the strongest genetic factor associated with development of Ankylosing Spondylitis and other spondyloarthropathies (SpA), yet the role it plays in disease pathogenesis remains unclear. We investigated the expression of potentially pathogenic non-conventional heavy chain forms (NC) of B27 in synovial and intestinal tissues obtained from SpA patients. We also determined the presence of NC-B27 in joints, lymphoid and gastrointestinal tissue from B27 transgenic (TG1) rats with M.tuberculosis-induced SpA.MethodsExpression of NC-B27 in human SpA joints and gut and in (21-3 × 283-2)F1 HLA-B27/Huβ2m rat tissue was determined by immunohistochemistry, flow cytometry and confocal microscopy analysis using HC10 and HD6 antibodies.ResultsBoth HC10- and HD6-reactive HLA molecules were present in synovial tissue from SpA patients. Both NC-B27 and KIR3DL2, a ligand for NC-B27, were expressed in inflamed terminal ileal tissues in patients with early SpA. Infiltrating cells in inflamed joint tissues isolated from B27 TG1 rats expressed high levels of NC-B27. NC-B27 were also expressed in joint-resident cells from ankle and tail joints of B27 TG1 rats prior to clinical arthritis. The expression of NC-B27 on B27 TG1 rat CD11b/c+, CD8α+, cells from spleens and LNs increased with animal age and disease progression.ConclusionsNon-conventional HLA class 1 molecules are expressed on resident and infiltrating cells in both synovial and GI tissues in human SpA. NC-B27 expression in joints and lymphoid tissues from B27 TG1 rats prior to the onset of arthritis is consistent with the hypothesis that they play a pathogenic role in SpA

    Pseudochelin A, a siderophore of Pseudoalteromonas piscicida S2040

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    A new siderophore containing a 4,5-dihydroimidazole moiety was isolated from Pseudoalteromonas piscicida S2040 together with myxochelins A and B, alteramide A and its cycloaddition product, and bromo- and dibromoalterochromides. The structure of pseudochelin A was established by spectroscopic techniques including 2D NMR and MS/MS fragmentation data. In bioassays selected fractions of the crude extract of S2040 inhibited the opportunistic pathogen Pseudomonas aeruginosa. Pseudochelin A displayed siderophore activity in the chrome azurol S assay at concentrations higher than 50 μM, and showed weak activity against the fungus Aspergillus fumigatus, but did not display antibacterial, anti-inflammatory or anticonvulsant activity

    Co‐developing guidance for conservation: An example for seabirds in the North‐East Atlantic in the face of climate change impacts

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    Conservation guidance—an authoritative source of information and recommendations explicitly supporting decision-making and action regarding nature conservation—represents an important tool to communicate evidence-based advice to conservation actors. Given the rapidly increasing pressure that climate change poses to biodiversity, producing accessible, well-informed guidance on how to best manage the impacts and risks of changing climatic conditions is particularly urgent. Guidance documents should ideally be produced with multistage input from stakeholders who are likely to use and implement such advice; however, this step can be complicated and costly, and remains largely unformalized. Moreover, there is currently little direct evidence synthesized for actions that specifically target climate change and guidance remains largely absent. Here, we introduce a process for co-developing guidance for species conservation in the face of climate change, using seabirds in the North-East Atlantic as a case study. Specifically, we collated evidence on climate change vulnerability and possible conservation actions using literature synthesis, stakeholder surveys, and ecological modeling. This evidence base was then discussed, refined, and expanded using structured stakeholder workshops. We summarize the knowledge gained through stakeholder engagement and provide recommendations for future international efforts to co-produce conservation guidance for managing wildlife, in the context of a rapidly changing climate.info:eu-repo/semantics/publishedVersio

    Dumb and Lazy? A Comparison of Color Learning and Memory Retrieval in Drones and Workers of the Buff-Tailed Bumblebee, Bombus terrestris, by Means of PER Conditioning

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    More than 100 years ago, Karl von Frisch showed that honeybee workers learn and discriminate colors. Since then, many studies confirmed the color learning capabilities of females from various hymenopteran species. Yet, little is known about visual learning and memory in males despite the fact that in most bee species males must take care of their own needs and must find rewarding flowers to obtain food. Here we used the proboscis extension response (PER) paradigm to study the color learning capacities of workers and drones of the bumblebee, Bombus terrestris. Light stimuli were paired with sucrose reward delivered to the insects’ antennae and inducing a reflexive extension of the proboscis. We evaluated color learning (i.e. conditioned PER to color stimuli) in absolute and differential conditioning protocols and mid-term memory retention was measured two hours after conditioning. Different monochromatic light stimuli in combination with neutral density filters were used to ensure that the bumblebees could only use chromatic and not achromatic (e.g. brightness) information. Furthermore, we tested if bees were able to transfer the learned information from the PER conditioning to a novel discrimination task in a Y-maze. Both workers and drones were capable of learning and discriminating between monochromatic light stimuli and retrieved the learned stimulus after two hours. Drones performed as well as workers during conditioning and in the memory test, but failed in the transfer test in contrast to workers. Our data clearly show that bumblebees can learn to associate a color stimulus with a sugar reward in PER conditioning and that both workers and drones reach similar acquisition and mid-term retention performances. Additionally, we provide evidence that only workers transfer the learned information from a Pavlovian to an operant situation

    Co-developing guidance for conservation: an example for seabirds in the North-East Atlantic in the face of climate change impacts

    Get PDF
    Conservation guidance—an authoritative source of information and recommendations explicitly supporting decision-making and action regarding nature conservation—represents an important tool to communicate evidence-based advice to conservation actors. Given the rapidly increasing pressure that climate change poses to biodiversity, producing accessible, well-informed guidance on how to best manage the impacts and risks of changing climatic conditions is particularly urgent. Guidance documents should ideally be produced with multistage input from stakeholders who are likely to use and implement such advice; however, this step can be complicated and costly, and remains largely unformalized. Moreover, there is currently little direct evidence synthesized for actions that specifically target climate change and guidance remains largely absent. Here, we introduce a process for co-developing guidance for species conservation in the face of climate change, using seabirds in the North-East Atlantic as a case study. Specifically, we collated evidence on climate change vulnerability and possible conservation actions using literature synthesis, stakeholder surveys, and ecological modeling. This evidence base was then discussed, refined, and expanded using structured stakeholder workshops. We summarize the knowledge gained through stakeholder engagement and provide recommendations for future international efforts to co-produce conservation guidance for managing wildlife, in the context of a rapidly changing climate

    SILS Effective Handover Project Report, December 2017

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    Scholarly Information and Learning Services (SILS) review and realignment occurred in 2015-2016, based on client perception and feedback about SILS’ purpose and effectiveness. A process for developing a new engagement model was conceived by the leadership team as a key component of implementing the new SILS structure. This process involved a number of consultation and planning workshops, including follow up experiments. These experiments were designed to test particular aspects of the suggested engagement model. A fundamental aspect of the proposed engagement model is the practice of ‘effective handovers’: that clients can contact any part of the organisation and be directed to the relevant section for assistance. Stakeholder feedback at USQ has consistently indicated that accessing appropriate SILS support is challenging. For this reason the effective handover of client enquiries was identified as a potential issue for the SILS engagement model investigation. A mixed methods approach was used based on a literature review, survey data, and a mystery shopper activity. To ensure best practice of client handovers, the following recommendations are provided: SILS to provide staff with a set of guidelines for best practice (see Appendix 2). Staff are encouraged to use handover guidelines as appropriate. As enquiries may differ a universal set of guidelines may not address the full range of scenarios. Staff to continue the positive and effective handover process, where applicable. As effective handovers requires an understanding of the roles of colleagues, staff should develop a knowledge of other departments within SILS. Information provided by other SILS engagement experiments will also inform this process

    Functional and Molecular Characterization of Mechanoinsensitive “Silent” Nociceptors

    Get PDF
    Mechanical and thermal hyperalgesia (pain hypersensitivity) are cardinal signs of inflammation. Although the mechanism underlying thermal hyperalgesia is well understood, the cellular and molecular basis of mechanical hyperalgesia is poorly described. Here, we have identified a subset of peptidergic C-fiber nociceptors that are insensitive to noxious mechanical stimuli under normal conditions but become sensitized to such stimuli when exposed to the inflammatory mediator nerve growth factor (NGF). Strikingly, NGF did not affect mechanosensitivity of other nociceptors. We show that these mechanoinsensitive “silent” nociceptors are characterized by the expression of the nicotinic acetylcholine receptor subunit alpha-3 (CHRNA3) and that the mechanically gated ion channel PIEZO2 mediates NGF-induced mechanosensitivity in these neurons. Retrograde tracing revealed that CHRNA3+ nociceptors account for ∼50% of all peptidergic nociceptive afferents innervating visceral organs and deep somatic tissues. Hence, our data suggest that NGF-induced “un-silencing” of CHRNA3+ nociceptors significantly contributes to the development of mechanical hyperalgesia during inflammation

    Exergaming in patients with a left ventricular assist device : a feasibility study

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    Aims Exercise games (exergames) have been recently proposed as a mode of facilitating physical activity in patients with chronic diseases. Although patients supported with left ventricular assist devices (LVADs) benefit from physical activity, specific LVAD-related issues hinder their ability to exercise properly. The objective of this study was to assess the feasibility and safety of exergaming in LVAD-supported patients. Methods and results Eleven LVAD-supported patients were enrolled in a 4 week exergaming programme using Nintendo Wii console with five sport games. Patients were instructed to play for 30 min a day, 5 days a week. Data on exercise capacity and exergaming were collected by using the 6 min walk test (6MWT) and a daily self-report diary, respectively. Feasibility of using the console and its safety was assessed by a semi-structured patient interview. Quality of life was assessed by the Minnesota Living with Heart failure Questionnaire (MLHFQ) and the Cantrils Ladder of Life. Safety was assessed by patients report in interview and diary. The study group consisted of 10 male patients and 1 female patient, mean age of 67 +/- 7 years, of whom 10 were supported with the HeartMate 3 LVAD for a median of 10 (interquartile range 3, 21) months. Baseline exercise capacity assessed by the 6MWT ranged from 240 to 570 m (mean 448 +/- 112). After 4 weeks of exergaming, 6MWT distance increased from a mean of 448 +/- 112 (evaluated in six patients) to 472 +/- 113 m (P = 0.023). Patients Cantrils Ladder of Life score improved numerically from an average of 6.13 to 7.67, as did their MLHFQ score from 45.9 +/- 27 to 38.7 +/- 18, with higher and lower scores, respectively, reflecting higher quality of life. No specific LVAD-related safety issues regarding exergaming were reported. Conclusions Exergaming was found to be a safe and feasible mode for encouraging physical activity in LVAD-supported patients and carries a potential for improving exercise capacity and quality of life in these patients. Larger scale studies are warranted to further investigate the effect of exergaming in this patient population.Funding Agencies|Swedish National Science Council [2016-01390]</p
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