540 research outputs found

    Regulatory T cells expressing granzyme B play a critical role in controlling lung inflammation during acute viral infection

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    The inflammatory response to lung infections must be tightly regulated, enabling pathogen elimination while maintaining crucial gas exchange. Using recently described “depletion of regulatory T cell” (DEREG) mice, we found that selective depletion of regulatory T cells (Tregs) during acute respiratory syncytial virus (RSV) infection enhanced viral clearance but increased weight loss, local cytokine and chemokine release, and T-cell activation and cellular influx into the lungs. Conversely, inflammation was decreased when Treg numbers and activity were boosted using interleukin-2 immune complexes. Unexpectedly, lung (but not draining lymph node) Tregs from RSV-infected mice expressed granzyme B (GzmB), and bone marrow chimeric mice with selective loss of GzmB in the Treg compartment displayed markedly enhanced cellular infiltration into the lung after infection. A crucial role for GzmB-expressing Tregs has not hitherto been described in the lung or during acute infections, but may explain the inability of children with perforin/GzmB defects to regulate immune responses to infection. The effects of RSV infection in mice with defective immune regulation closely parallel the observed effects of RSV in children with bronchiolitis, suggesting that the pathogenesis of bronchiolitis may involve an inability to regulate virus-induced inflammation

    Perfectionism and training performance: The mediating role of other-approach goals

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    Recent research found perfectionistic strivings to predict performance in a novel basketball task among novice basketball players. The current study builds on this research by examining whether this is also the case for performance in a familiar basketball training task among experienced basketball players, and whether achievement goals mediated any observed relationships. Perfectionistic strivings, perfectionistic concerns, and 3 × 2 achievement goals were assessed prior to basketball training performance in 90 basketball players (mean age 20.9 years). Regression analyses showed that perfectionistic strivings predicted better performance. Furthermore, mediation analyses showed that other-approach goals (e.g., beliefs that one should and can outperform others) accounted for this relationship. The findings suggest that perfectionistic strivings may predict better performance in both novel and familiar athletic contexts. In addition, beliefs about the importance and ability to outperform others may explain this relationship

    Metagenomic Analysis of RNA Viruses in a Fresh Water Lake

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    Freshwater lakes and ponds present an ecological interface between humans and a variety of host organisms. They are a habitat for the larval stage of many insects and may serve as a medium for intraspecies and interspecies transmission of viruses such as avian influenza A virus. Furthermore, freshwater bodies are already known repositories for disease-causing viruses such as Norwalk Virus, Coxsackievirus, Echovirus, and Adenovirus. While RNA virus populations have been studied in marine environments, to this date there has been very limited analysis of the viral community in freshwater. Here we present a survey of RNA viruses in Lake Needwood, a freshwater lake in Maryland, USA. Our results indicate that just as in studies of other aquatic environments, the majority of nucleic acid sequences recovered did not show any significant similarity to known sequences. The remaining sequences are mainly from viral types with significant similarity to approximately 30 viral families. We speculate that these novel viruses may infect a variety of hosts including plants, insects, fish, domestic animals and humans. Among these viruses we have discovered a previously unknown dsRNA virus closely related to Banna Virus which is responsible for a febrile illness and is endemic to Southeast Asia. Moreover we found multiple viral sequences distantly related to Israeli Acute Paralysis virus which has been implicated in honeybee colony collapse disorder. Our data suggests that due to their direct contact with humans, domestic and wild animals, freshwater ecosystems might serve as repositories of a wide range of viruses (both pathogenic and non-pathogenic) and possibly be involved in the spread of emerging and pandemic diseases

    Physical mechanisms of ESCRT-III-driven cell division

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    Living systems propagate by undergoing rounds of cell growth and division. Cell division is at heart a physical process that requires mechanical forces, usually exerted by assemblies of cytoskeletal polymers. Here we developed a physical model for the ESCRT-III-mediated division of archaeal cells, which despite their structural simplicity share machinery and evolutionary origins with eukaryotes. By comparing the dynamics of simulations with data collected from live cell imaging experiments, we propose that this branch of life uses a previously unidentified division mechanism. Active changes in the curvature of elastic cytoskeletal filaments can lead to filament perversions and supercoiling, to drive ring constriction and deform the overlying membrane. Abscission is then completed following filament disassembly. The model was also used to explore how different adenosine triphosphate (ATP)-driven processes that govern the way the structure of the filament is changed likely impact the robustness and symmetry of the resulting division. Comparisons between midcell constriction dynamics in simulations and experiments reveal a good agreement with the process when changes in curvature are implemented at random positions along the filament, supporting this as a possible mechanism of ESCRT-III-dependent division in this system. Beyond archaea, this study pinpoints a general mechanism of cytokinesis based on dynamic coupling between a coiling filament and the membrane

    Sulforaphane represses matrix-degrading proteases and protects cartilage from destruction in vitro and in vivo:Sulforaphane is protective in the articular Joint

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    Sulforaphane (SFN) has been reported to regulate signaling pathways relevant to chronic diseases. The aim of this study was to investigate the impact of SFN treatment on signaling pathways in chondrocytes and to determine whether sulforaphane could block cartilage destruction in osteoarthritis

    Detecting new microRNAs in human osteoarthritic chondrocytes identifies miR-3085 as a human, chondrocyte-selective, microRNA

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    Objective: To use deep sequencing to identify novel microRNAs in human osteoarthritic cartilage which have a functional role in chondrocyte phenotype or function. Design: A small RNA library was prepared from human osteoarthritic primary chondrocytes using in-house adaptors and analysed by Illumina sequencing. Novel candidate microRNAs were validated by northern blot and qRT-PCR. Expression was measured in cartilage models. Targets of novel candidates were identified by microarray and computational analysis, validated using 3’-UTR-luciferase reporter plasmids. Protein levels were assessed by western blot and functional analysis by cell adhesion. Results: We identified 990 known microRNAs and 1621 potential novel microRNAs in human osteoarthritic chondrocytes, 60 of the latter were expressed in all samples assayed. MicroRNA-140-3p was the most highly expressed microRNA in osteoarthritic cartilage. Sixteen novel candidate microRNAs were analysed further, of which 6 remained after northern blot analysis. Three novel microRNAs were regulated across models of chondrogenesis, chondrocyte differentiation or cartilage injury. One sequence (novel #11), annotated in rodents as microRNA-3085-3p, was preferentially expressed in cartilage, dependent on chondrocyte differentiation and, in man, is located in an intron of the cartilage-expressed gene CRTAC-1. This microRNA was shown to target the ITGA5 gene directly (which encodes integrin alpha5) and inhibited adhesion to fibronectin (dependent on alpha5beta1 integrin). Conclusion: Deep sequencing has uncovered many potential microRNA candidates expressed in human cartilage. At least three of these show potential functional interest in cartilage homeostasis and osteoarthritis. Particularly, novel #11 (microRNA-3085-3p) which has been identified for the first time in man

    Synthesis of a series of novel 3,9-disubstituted phenanthrenes as analogues of known <i>N</i>-methyl-D-aspartate receptor allosteric modulators

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    9-Substituted phenanthrene-3-carboxylic acids have been reported to have allosteric modulatory activity at the NMDA receptor. This receptor is activated by the excitatory neurotransmitter L-glutamate and has been implicated in a range of neurological disorders such as schizophrenia, epilepsy and chronic pain and neurodegenerative disorders such as Alzheimer’s disease. Herein, the convenient synthesis of a wide range of novel 3,9-disubstituted phenanthrene derivatives starting from a few common intermediates is described. These new phenanthrene derivatives will help to clarify the structural requirements for allosteric modulation of the NMDA receptor

    Does wearing arthritis gloves help with hand pain and function? A qualitative study into patients’ views and experiences

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    Objectives: Arthritis gloves are frequently prescribed to people with undifferentiated inflammatory (UIA) or rheumatoid arthritis (RA), to help reduce hand pain and improve function. Nested within a randomised controlled trial testing the effectiveness of arthritis gloves (Isotoner gloves versus loose-fitting placebo gloves) in people with RA and UIA, this qualitative study aimed to explore participants’ views on the impact of wearing arthritis gloves on their hand pain and function. Methods: Semi-structured one-to-one interviews were conducted with purposively selected participants following 12-weeks of glove wear. Participants and the interviewer were blinded to the treatment allocation. Interviews were audio-recorded, transcribed verbatim and analysed using thematic analysis. Results: Participants (intervention n=10; control n=9) recruited from 13 NHS hospital sites in the UK participated in the interviews. Two main themes, with sub-themes, were elicited from the data: (1) Mechanisms determining glove use: ‘As soon as your joints get a bit warmer, the pain actually eases’ (thermal qualities; glove-use in daily activities; glove-use during sleep); and (2) Ambivalence about benefits of arthritis gloves: ‘I suppose a normal pair of gloves would do the same sort of thing?’ (are they a help or hindrance?; aesthetic appeal; future use of gloves). Conclusion: Participants had ambivalent views on the impact of both the intervention and loose-fitting placebo gloves on their hand pain and function, identifying warmth as the main benefit. Ordinary mid-finger length gloves widely accessible from high street suppliers could deliver warmth and provide perceived benefits to hand pain and function

    Collagen fingerprinting traces the introduction of caprines to island Eastern Africa

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    The human colonization of eastern Africa's near- and offshore islands was accompanied by the translocation of several domestic, wild and commensal fauna, many of which had long-term impacts on local environments. To better understand the timing and nature of the introduction of domesticated caprines (sheep and goat) to these islands, this study applied collagen peptide fingerprinting (Zooarchaeology by Mass Spectrometry or ZooMS) to archaeological remains from eight Iron Age sites, dating between ca 300 and 1000 CE, in the Zanzibar, Mafia and Comoros archipelagos. Where previous zooarchaeological analyses had identified caprine remains at four of these sites, this study identified goat at seven sites and sheep at three, demonstrating that caprines were more widespread than previously known. The ZooMS results support an introduction of goats to island eastern Africa from at least the seventh century CE, while sheep in our sample arrived one–two centuries later. Goats may have been preferred because, as browsers, they were better adapted to the islands' environments. The results allow for a more accurate understanding of early caprine husbandry in the study region and provide a critical archaeological baseline for examining the potential long-term impacts of translocated fauna on island ecologies.1. Introduction 2. Background 2.1. Island colonization and species translocations 2.2. Tracing the introduction of caprines to insular Eastern Africa 3. Methods 3.1. Sites 3.2. Sample selection 3.3. ZooMS protocol 3.3.1. Acid-insoluble protocol 3.3.2. Acid-soluble protocol 3.3.3. Lyophilized collagen for stable isotope analysis 3.3.4. C18 clean-up and MALDI-ToF analysis 4. Results 5. Discussion 5.1. Diachronic patterns in the introduction of caprines 5.2. Island herd compositions 5.3. Wild faunal extirpations and translocations 5.4. Long-term ecological impacts of caprines on Eastern Africa’s islands 6. Conclusio
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