375 research outputs found

    Attrition in School Rowing in New Zealand: A Qualitative Descriptive Study

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    It is widely acknowledged that involvement in sport has positive physical and psychosocial benefits for adolescents. However, concerns have been expressed, both in New Zealand and internationally, about the relatively high attrition rates in youth sport. This qualitative study captured the experiences of eight (five male, three female) adolescents who were no longer participating in high school rowing programs in New Zealand. Data were gathered through semi-structured interviews, and we conducted an inductive thematic analysis. A secondary analysis was then conducted using a self-determination and basic psychological needs framework that placed specific emphasis on need satisfaction and need thwarting. Key findings from this study suggest that participants’ experiences of rowing were initially positive but were subsequently influenced by dissatisfaction and thwarting of basic psychological needs. The findings confirm the significance of coaches and parents providing an environment that supports young athletes’ needs for relatedness. Concerns are also raised about the potentially damaging effects of weight-restricted sport for adolescents. By drawing upon athlete voice, it is hoped that the findings of this study can inform coach education and result in the development of more athlete-supportive rowing programs for adolescent athletes

    Filamentous Fungal Carbon Catabolite Repression Supports Metabolic Plasticity and Stress Responses Essential for Disease Progression

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    Aspergillus fumigatus is responsible for a disproportionate number of invasive mycosis cases relative to other common filamentous fungi. While many fungal factors critical for infection establishment are known, genes essential for disease persistence and progression are ill defined. We propose that fungal factors that promote navigation of the rapidly changing nutrient and structural landscape characteristic of disease progression represent untapped clinically relevant therapeutic targets. To this end, we find that A. fumigatus requires a carbon catabolite repression (CCR) mediated genetic network to support in vivo fungal fitness and disease progression. While CCR as mediated by the transcriptional repressor CreA is not required for pulmonary infection establishment, loss of CCR inhibits fungal metabolic plasticity and the ability to thrive in the dynamic infection microenvironment. Our results suggest a model whereby CCR in an environmental filamentous fungus is dispensable for initiation of pulmonary infection but essential for infection maintenance and disease progression. Conceptually, we argue these data provide a foundation for additional studies on fungal factors required to support fungal fitness and disease progression and term such genes and factors, DPFs (disease progression factors)

    Extensive spontaneous plasticity of corticospinal projections after primate spinal cord injury.

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    Although axonal regeneration after CNS injury is limited, partial injury is frequently accompanied by extensive functional recovery. To investigate mechanisms underlying spontaneous recovery after incomplete spinal cord injury, we administered C7 spinal cord hemisections to adult rhesus monkeys and analyzed behavioral, electrophysiological and anatomical adaptations. We found marked spontaneous plasticity of corticospinal projections, with reconstitution of fully 60% of pre-lesion axon density arising from sprouting of spinal cord midline-crossing axons. This extensive anatomical recovery was associated with improvement in coordinated muscle recruitment, hand function and locomotion. These findings identify what may be the most extensive natural recovery of mammalian axonal projections after nervous system injury observed to date, highlighting an important role for primate models in translational disease research

    RbdB, a Rhomboid Protease Critical for SREBP Activation and Virulence in Aspergillus Fumigatus

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    SREBP transcription factors play a critical role in fungal virulence; however, the mechanisms of sterol regulatory element binding protein (SREBP) activation in pathogenic fungi remains ill-defined. Screening of the Neurospora crassa whole-genome deletion collection for genes involved in hypoxia responses identified a gene for an uncharacterized rhomboid protease homolog, rbdB, required for growth under hypoxic conditions. Loss of rbdB in Aspergillus fumigatus also inhibited growth under hypoxic conditions. In addition, the A. fumigatus ΔrbdB strain also displayed phenotypes consistent with defective SREBP activity, including increased azole drug susceptibility, reduced siderophore production, and full loss of virulence. Expression of the basic helix-loop-helix (bHLH) DNA binding domain of the SREBP SrbA in ΔrbdB restored all of the phenotypes linking RdbB activity with SrbA function. Furthermore, the N-terminal domain of SrbA containing the bHLH DNA binding region was absent from ΔrbdB under inducing conditions, suggesting that RbdB regulates the protein levels of this important transcription factor. As SrbA controls clinically relevant aspects of fungal pathobiology in A. fumigatus, understanding the mechanisms of SrbA activation provides opportunities to target this pathway for therapeutic development

    Exome analysis of patients with concurrent pediatric inflammatory bowel disease (PIBD) and autoimmune disease

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    BACKGROUND: Pediatric Inflammatory Bowel Disease (PIBD) is a chronic condition seen in genetically predisposed individuals. Genome-wide association studies have implicated >160 genomic loci in IBD with many genes coding for proteins in key immune pathways. This study looks at autoimmune disease burden in patients diagnosed with PIBD and interrogates exome data of a subset of patients. METHODS: Patients were recruited from the Southampton Genetics of PIBD cohort. Clinical diagnosis of autoimmune disease in these individuals was ascertained from medical records. For a subset of patients with PIBD and concurrent asthma, exome data was interrogated to ascertain the burden of pathogenic variants within genes implicated in asthma. Association testing was conducted between cases and population controls using the SKAT-O test. RESULTS: Forty-nine (28.3%) PIBD children (18.49% CD, 8.6% UC, and 21.15% IBDU patients) had a concurrent clinical diagnosis of at least one other autoimmune disorder; asthma was the most prevalent, affecting 16.2% of the PIBD cohort. Rare and common variant association testing revealed 6 significant genes (P < 0.05) before Bonferroni adjustment. Three of these genes were previously implicated in both asthma and IBD (ZPBP2 IL1R1, and IL18R1) and 3 in asthma only (PYHIN1, IL2RB, and GSTP1). CONCLUSIONS: One-third of our cohort had a concurrent autoimmune condition. We observed higher incidence of asthma compared with the overall pediatric prevalence. Despite a small sample size, SKAT-O evaluated a significant burden of rare and common mutations in 6 genes. Variant burden suggests that a systemic immune dysregulation rather than organ-specific could underpin immune dysfunction for a subset of patients

    Heterogeneity among Isolates Reveals that Fitness in Low Oxygen Correlates with Aspergillus fumigatus Virulence

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    Previous work has shown that environmental and clinical isolates of Aspergillus fumigatus represent a diverse population that occupies a variety of niches, has extensive genetic diversity, and exhibits virulence heterogeneity in a number of animal models of invasive pulmonary aspergillosis (IPA). However, mechanisms explaining differences in virulence among A. fumigatus isolates remain enigmatic. Here, we report a significant difference in virulence of two common lab strains, CEA10 and AF293, in the murine triamcinolone immunosuppression model of IPA, in which we previously identified severe low oxygen microenvironments surrounding fungal lesions. Therefore, we hypothesize that the ability to thrive within these lesions of low oxygen promotes virulence of A. fumigatus in this model. To test this hypothesis, we performed in vitro fitness and in vivo virulence analyses in the triamcinolone murine model of IPA with 14 environmental and clinical isolates of A. fumigatus Among these isolates, we observed a strong correlation between fitness in low oxygen in vitro and virulence. In further support of our hypothesis, experimental evolution of AF293, a strain that exhibits reduced fitness in low oxygen and reduced virulence in the triamcinolone model of IPA, results in a strain (EVOL20) that has increased hypoxia fitness and a corresponding increase in virulence. Thus, the ability to thrive in low oxygen correlates with virulence of A. fumigatus isolates in the context of steroid-mediated murin

    The Epithelial Cell-Derived Atopic Dermatitis Cytokine TSLP Activates Neurons to Induce Itch

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    SummaryAtopic dermatitis (AD) is a chronic itch and inflammatory disorder of the skin that affects one in ten people. Patients suffering from severe AD eventually progress to develop asthma and allergic rhinitis, in a process known as the “atopic march.” Signaling between epithelial cells and innate immune cells via the cytokine thymic stromal lymphopoietin (TSLP) is thought to drive AD and the atopic march. Here, we report that epithelial cells directly communicate to cutaneous sensory neurons via TSLP to promote itch. We identify the ORAI1/NFAT calcium signaling pathway as an essential regulator of TSLP release from keratinocytes, the primary epithelial cells of the skin. TSLP then acts directly on a subset of TRPA1-positive sensory neurons to trigger robust itch behaviors. Our results support a model whereby calcium-dependent TSLP release by keratinocytes activates both primary afferent neurons and immune cells to promote inflammatory responses in the skin and airways

    Exome analysis of rare and common variants within the NOD signaling pathway

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    Pediatric inflammatory bowel disease (pIBD) is a chronic heterogeneous disorder. This study looks at the burden of common and rare coding mutations within 41 genes comprising the NOD signaling pathway in pIBD patients. 136 pIBD and 106 control samples underwent whole-exome sequencing. We compared the burden of common, rare and private mutation between these two groups using the SKAT-O test. An independent replication cohort of 33 cases and 111 controls was used to validate significant findings. We observed variation in 40 of 41 genes comprising the NOD signaling pathway. Four genes were significantly associated with disease in the discovery cohort (BIRC2 p = 0.004, NFKB1 p =  0.005, NOD2 p = 0.029 and SUGT1 p = 0.047). Statistical significance was replicated for BIRC2 (p = 0.041) and NOD2 (p = 0.045) in an independent validation cohort. A gene based test on the combined discovery and replication cohort confirmed association for BIRC2 (p = 0.030). We successfully applied burden of mutation testing that jointly assesses common and rare variants, identifying two previously implicated genes (NFKB1 and NOD2) and confirmed a possible role in disease risk in a previously unreported gene (BIRC2). The identification of this novel gene provides a wider role for the inhibitor of apoptosis gene family in IBD pathogenesis

    16S sequencing and functional analysis of the fecal microbiome during treatment of newly diagnosed pediatric inflammatory bowel disease

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    JJA is funded by a National Institute of Health Research Academic Clinical Fellowship and has received an Action Medical Research training fellowship. TC is funded by a Crohn’s in Childhood research association fellowship. CMC received a PhD studentship from SULSA Spirit industrial studentship. The NGS analysis was made possible by the award of a grant from the Source Bioscience 110th year anniversary promotion to CMC. The Rowett Institute receives funding from the Scottish Government (RESAS).Peer reviewedPublisher PD
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