105 research outputs found

    A Synthetic Loop Replacement Peptide That Blocks Canonical NFâ κB Signaling

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    Aberrant canonical NFâ κB signaling is implicated in diseases from autoimmune disorders to cancer. A major therapeutic challenge is the need for selective inhibition of the canonical pathway without impacting the many nonâ canonical NFâ κB functions. Here we show that a selective peptideâ based inhibitor of canonical NFâ κB signaling, in which a hydrogen bond in the NBD peptide is synthetically replaced by a nonâ labile bond, shows an about 10â fold increased potency relative to the original inhibitor. Not only is this molecule, NBD2, a powerful tool for dissection of canonical NFâ κB signaling in disease models and healthy tissues, the success of the synthetic loop replacement suggests that the general strategy could be useful for discovering modulators of the many proteinâ protein interactions mediated by such structures.A peptideâ based inhibitor of canonical NFâ κB signaling, in which a hydrogen bond in the NBD peptide is synthetically replaced by a nonâ labile bond, shows an about 10â fold increased potency relative to the original inhibitor. The success of the synthetic replacement of a peptide loop suggests that the general strategy could be broadly useful for discovering modulators of many proteinâ protein interactions mediated by such structures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135096/1/anie201607990.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135096/2/anie201607990-sup-0001-misc_information.pd

    Augmented pain behavioural responses to intra-articular injection of nerve growth factor in two animal models of osteoarthritis

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    Acknowledgements The authors would like to thank Paul Millns for his technical assistance with tissue (dorsal root ganglia) collection. Competing interests None. Provenance and peer review Not commissioned; externally peer reviewedPeer reviewedPublisher PD

    Structural associations of symptomatic knee osteoarthritis

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    Objective Structural changes of osteoarthritis (OA) may occur in the absence of pain. In this study, we aimed to identify histopathologic features that are associated with symptomatic knee OA. Methods Medial tibial plateaus and synovium samples were obtained at the time of total knee replacement (TKR) surgery for OA (advanced OA group) or were obtained postmortem from subjects who had not sought medical attention for knee pain during the last year of life (non-OA control group). To identify features of OA, we compared the patients with advanced OA with the age-matched non-OA controls (n = 26 per group). To identify OA features associated with symptoms, we compared two additional groups of subjects who were matched for severity of chondropathy (n = 29 per group): patients undergoing TKR for symptomatic OA (symptomatic chondropathy group) and postmortem subjects with similar severity of chondropathy who were asymptomatic during the last year of life (asymptomatic chondropathy group). The histologic features of the samples were graded, and immunoreactivities for macrophages (CD68) and nerve growth factor (NGF) in the synovium were quantified. The cellular localization of synovial NGF was determined by double immunofluorescence analysis. Results Advanced OA cases displayed more severe changes in the synovium (synovitis, increased synovial NGF, and CD68-immunoreactive macrophages) and cartilage (loss of cartilage surface integrity, loss of proteoglycan, tidemark breaching, and alterations in chondrocyte morphology) than did the non-OA controls. Synovial NGF was localized predominantly to fibroblasts and to some macrophages. The symptomatic chondropathy group displayed greater levels of synovitis, synovial NGF, and loss of cartilage integrity, in addition to alterations in chondrocyte morphology, than did the asymptomatic chondropathy group (P < 0.05 for each comparison). Conclusion Synovitis, increased synovial NGF, alterations in chondrocyte morphology, and loss of cartilage integrity are features of knee OA that may be associated with symptoms

    How can we make self-sampling packs for sexually transmitted infections and bloodborne viruses more inclusive? a qualitative study with people with mild learning disabilities and low health literacy

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    Objectives: 1.5 million people in the UK have mild to moderate learning disabilities. STIs and bloodborne viruses (BBVs) are over-represented in people experiencing broader health inequalities, which include those with mild learning disabilities. Self-managed care, including self-sampling for STIs/BBVs, is increasingly commonplace, requiring agency and health literacy. To inform the development of a partner notification trial, we explored barriers and facilitators to correct use of an STI/BBV self-sampling pack among people with mild learning disabilities. Methods: Using purposive and convenience sampling we conducted four interviews and five gender-specific focus groups with 25 people (13 women, 12 men) with mild learning disabilities (July-August 2018) in Scotland. We balanced deductive and inductive thematic analyses of audio transcripts to explore issues associated with barriers and facilitators to correct use of the pack. Results: All participants found at least one element of the pack challenging or impossible, but welcomed the opportunity to undertake sexual health screening without attending a clinic and welcomed the inclusion of condoms. Reported barriers to correct use included perceived overly complex STI/BBV information and instructions, feeling overwhelmed and the manual dexterity required for blood sampling. Many women struggled interpreting anatomical diagrams depicting vulvovaginal self-swabbing. Facilitators included pre-existing STI/BBV knowledge, familiarity with self-management, good social support and knowing that the service afforded privacy. Conclusion: In the first study to explore the usability of self-sampling packs for STI/BBV in people with learning disabilities, participants found it challenging to use the pack. Limiting information to the minimum required to inform decision-making, € easy read' formats, simple language, large font sizes and simpler diagrams could improve acceptability. However, some people will remain unable to engage with self-sampling at all. To avoid widening health inequalities, face-to-face options should continue to be provided for those unable or unwilling to engage with self-managed care

    A qualitative process evaluation using the behaviour change wheel approach: Did a whole genome sequence report form (SRF) used to reduce nosocomial SARS-CoV-2 within UK hospitals operate as anticipated?

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    PURPOSE: The aim of this study was to conduct a process evaluation of a whole-genome sequence report form (SRF) used to reduce nosocomial SARS-CoV-2 through changing infection prevention and control (IPC) behaviours within the COVID-19 pandemic. METHODS: We used a three-staged design. Firstly, we described and theorized the purported content of the SRF using the behaviour change wheel (BCW). Secondly, we used inductive thematic analysis of one-to-one interviews (n = 39) to explore contextual accounts of using the SRF. Thirdly, further deductive analysis gauged support for the intervention working as earlier anticipated. RESULTS: It was possible to theorize the SRF using the BCW approach and visualize it within a simple logic model. Inductive thematic analyses identified the SRF's acceptability, ease of use and perceived effectiveness. However, major challenges to embedding it in routine practice during the unfolding COVID-19 crisis were reported. Notwithstanding this insight, deductive analysis showed support for the putative intervention functions 'Education', 'Persuasion' and 'Enablement'; behaviour change techniques '1.2 Problem solving', '2.6 Biofeedback', '2.7 Feedback on outcomes of behaviour' and '7.1 Prompts and cues'; and theoretical domains framework domains 'Knowledge' and 'Behavioural regulation'. CONCLUSIONS: Our process evaluation of the SRF, using the BCW approach to describe and theorize its content, provided granular support for the SRF working to change IPC behaviours as anticipated. However, our complementary inductive thematic analysis highlighted the importance of the local context in constraining its routine use. For SRFs to reach their full potential in reducing nosocomial infections, further implementation research is needed

    Blocking the tropomyosin receptor kinase A (TrkA) receptor inhibits pain behaviour in two rat models of osteoarthritis

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    Objectives: Tropomyosin receptor kinase A (TrkA) mediates nociceptor sensitisation by nerve growth factor (NGF), but it is unknown whether selective TrkA inhibition will be an effective strategy for treating osteoarthritis (OA) pain. We determined the effects of a TrkA inhibitor (AR786) on pain behaviour, synovitis and joint pathology in two rat OA models. Methods: Knee OA was induced in rats by intraarticular monosodium-iodoacetate (MIA) injection or meniscal transection (MNX) and compared with saline injected or sham-operated controls. Pain behaviour was assessed as weight-bearing asymmetry and paw withdrawal threshold to punctate stimulation. Oral doses (30 mg/kg) of AR786 or vehicle were administered twice daily in either preventive (day −1 to –27) or treatment (day 14–28) protocols. Effect maintenance was evaluated for 2 weeks after treatment discontinuation. Alterations in knee structure (cartilage, subchondral bone and synovium) were examined by macroscopic visualisation of articular surfaces and histopathology. Results: Preventive AR786 treatment inhibited pain behaviour development and therapeutic treatment attenuated established pain behaviour. Weight-bearing asymmetry increased 1 week after treatment discontinuation, but remained less than in vehicle- treated arthritic rats, whereas paw withdrawal thresholds returned to levels of untreated rats within 5 days of treatment discontinuation. AR786 treatment reduced MIA-induced synovitis and did not significantly affect osteochondral pathology in either model. Conclusions: Blocking NGF activity by inhibiting TrkA reduced pain behaviour in two rat models of OA. Analgesia was observed both using preventive and treatment protocols, and was sustained after treatment discontinuation. Selective inhibitors of TrkA therefore hold potential for OA pain relief

    Therapeutic benefit for late, but not early, passage mesenchymal stem cells on pain behaviour in an animal model of osteoarthritis

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    Background: Mesenchymal stem cells (MSCs) have a therapeutic potential for the treatment of osteoarthritic (OA) joint pathology and pain. The aims of this study were to determine the influence of a passage number on the effects of MSCs on pain behaviour and cartilage and bone features in a rodent model of OA. Methods: Rats underwent either medial meniscal transection (MNX) or sham surgery under anaesthesia. Rats received intra-articular injection of either 1.5×106 late passage MSCs labelled with 10 μg/ml SiMAG, 1.5×106 late passage mesenchymal stem cells, the steroid Kenalog (200 μg/20 μL), 1.5×106 early passage MSCs, or serum-free media (SFM). Sham-operated rats received intra-articular injection of SFM. Pain behaviour was quantified until day 42 postmodel induction. Magnetic resonance imaging (MRI) was used to localise the labelled cells within the knee joint. Results: Late passage MSCs and Kenalog attenuated established pain behaviour in MNX rats, but did not alter MNX-induced joint pathology at the end of the study period. Early passage MSCs exacerbated MNX-induced pain behaviour for up to one week postinjection and did not alter joint pathology. Conclusion: Our data demonstrate for the first time the role of a passage number in influencing the therapeutic effects of MSCs in a model of OA pain

    Targeting the D-series resolvin receptor system for the treatment of osteoarthritic pain

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    Objective: Pain is a major symptom of osteoarthritis (OA); current analgesics either do not offer adequate pain relief or are associated with serious side effects. Herein we have investigated the therapeutic potential of targeting the resolvin receptor system to modify OA pain and pathology. Methods: Gene expression of two resolvin receptors (ALX and ChemR23) was quantified in synovia and medial tibial plateau collected from patients at joint replacement for OA. Two models of OA joint pain were used for mechanistic studies. Gene expression in the periphery and CNS were quantified. Effects of exogenous administration of the D-series resolvin precursor 17(R)-hydroxy Docosahexaenoic Acid (17(R)-HDoHE on pain behaviour, joint pathology, spinal microglia and astroglyosis were quantified. Plasma levels of relevant lipids, resolvin D2, 17R-HDoHE and arachidonic acid was determined in rats using LC-MS-MS. Results: There was a positive correlation between resolvin receptor and IL6 expression in human OA synovia and medial tibial plateau. In the rat, synovia gene expression of ALX was positively correlated with IL1β, TNFι and COX2. Treatment with 17(R)-HDoHE reversed established pain behaviour in two models of OA pain, but not joint pathology. This was associated with a significant elevation in plasma levels of resolvin D2 and a significant reduction in astrogliosis in the spinal cord in the MIA model. Conclusion: Our preclinical data demonstrate robust analgesics effects of activating the D series resolvin pathways in two different animal models of OA. Our data support a predominant central mechanism of action in this clinically relevant model of OA pain

    Protocol for the COG-UK hospital-onset COVID-19 infection (HOCI) multicentre interventional clinical study: evaluating the efficacy of rapid genome sequencing of SARS-CoV-2 in limiting the spread of COVID-19 in UK NHS hospitals

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    OBJECTIVES: Nosocomial transmission of SARS-CoV-2 has been a significant cause of mortality in National Health Service (NHS) hospitals during the COVID-19 pandemic. The COG-UK Consortium Hospital-Onset COVID-19 Infections (COG-UK HOCI) study aims to evaluate whether the use of rapid whole-genome sequencing of SARS-CoV-2, supported by a novel probabilistic reporting methodology, can inform infection prevention and control (IPC) practice within NHS hospital settings. DESIGN: Multicentre, prospective, interventional, superiority study. SETTING: 14 participating NHS hospitals over winter–spring 2020/2021 in the UK. PARTICIPANTS: Eligible patients must be admitted to hospital with first-confirmed SARS-CoV-2 PCR-positive test result &gt;48 hour from time of admission, where COVID-19 diagnosis not suspected on admission. The projected sample size is 2380 patients. INTERVENTION: The intervention is the return of a sequence report, within 48 hours in one phase (rapid local lab processing) and within 5–10 days in a second phase (mimicking central lab), comparing the viral genome from an eligible study participant with others within and outside the hospital site. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcomes are incidence of Public Health England (PHE)/IPC-defined SARS-CoV-2 hospital-acquired infection during the baseline and two interventional phases, and proportion of hospital-onset cases with genomic evidence of transmission linkage following implementation of the intervention where such linkage was not suspected by initial IPC investigation. Secondary outcomes include incidence of hospital outbreaks, with and without sequencing data; actual and desirable changes to IPC actions; periods of healthcare worker (HCW) absence. Health economic analysis will be conducted to determine cost benefit of the intervention. A process evaluation using qualitative interviews with HCWs will be conducted alongside the study. TRIAL REGISTRATION NUMBER: ISRCTN50212645. Pre-results stage. This manuscript is based on protocol V.6.0. 2 September 2021
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