177 research outputs found

    Hair cells in the inner ear of the pirouette and shaker 2 mutant mice

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    The shaker 2 ( sh2 ) and pirouette ( pi ) mouse mutants display severe inner ear dysfunction that involves both auditory and vestibular manifestation. Pathology of the stereocilia of hair cells has been found in both mutants. This study was designed to further our knowledge of the pathological characteristics of the inner ear sensory epithelia in both the sh2 and pi strains. Measurements of auditory brainstem responses indicated that both mutants were profoundly deaf. The morphological assays were specifically designed to characterize a pathological actin bundle that is found in both the inner hair cells and the vestibular hair cells in all five vestibular organs in these two mutants. Using light microscope analysis of phalloidin-stained specimens, these actin bundles could first be detected on postnatal day 3. As the cochleae matured, each inner hair cell and type I vestibular hair cell contained a bundle that spans from the region of the cuticular plate to the basal end of the cell, then extends along with cytoplasm and membrane, towards the basement membrane. Abnormal contact with the basement membrane was found in vestibular hair cells. Based on the shape of the cellular extension and the actin bundle that supports it, we propose to name these extensions “cytocauds.” The data suggest that the cytocauds in type I vestibular hair cells and inner hair cells are associated with a failure to differentiate and detach from the basement membrane.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47461/1/11068_2004_Article_278960.pd

    Mutation update and genotype-phenotype correlations of novel and previously described mutations in TPM2 and TPM3 causing congenital myopathies

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    Mutations affecting skeletal muscle isoforms of the tropomyosin genes may cause nemaline myopathy, cap myopathy, core-rod myopathy, congenital fiber-type disproportion, distal arthrogryposes, and Escobar syndrome. We correlate the clinical picture of these diseases with novel (19) and previously reported (31) mutations of the TPM2 and TPM3 genes. Included are altogether 93 families: 53 with TPM2 mutations and 40 with TPM3 mutations. Thirty distinct pathogenic variants of TPM2 and 20 of TPM3 have been published or listed in the Leiden Open Variant Database (http://www.dmd.nl/). Most are heterozygous changes associated with autosomal-dominant disease. Patients with TPM2 mutations tended to present with milder symptoms than those with TPM3 mutations, DA being present only in the TPM2 group. Previous studies have shown that five of the mutations in TPM2 and one in TPM3 cause increased Ca2+ sensitivity resulting in a hypercontractile molecular phenotype. Patients with hypercontractile phenotype more often had contractures of the limb joints (18/19) and jaw (6/19) than those with nonhypercontractile ones (2/22 and 1/22), whereas patients with the non-hypercontractile molecular phenotype more often (19/22) had axial contractures than the hypercontractile group (7/19). Our in silico predictions show that most mutations affect tropomyosin–actin association or tropomyosin head-to-tail binding

    ‘Seeing the bigger picture’: a post-graduate online learning community facilitates political competence for occupational therapists

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    © 2019, © 2019 UCU. Occupational therapists are increasingly required to work beyond traditional health-care settings in new and emerging community roles. This study explored the learning experiences of a cohort of international students studying an online post-graduate module aimed at facilitating political competence. The evaluation used an ethnographic approach and methods included online data from online communication tools: semi-structured interviews, and tutors’ reflective diaries. Data were subjected to thematic analysis. Results showed shifts in students’ knowledge, skills and attitudes in seeing the bigger picture; developing collaborative partnerships and navigating the politics of practice at the margins of personal, political and professional positions. Themes from learning which promoted changes were interacting with online resources, valuing and sharing experiences, a safe and supportive environment, integrated learning and assessment, critical self and peer review. Importantly the democratic approach of online learning was shown to align with the principles of political and critical occupational therapy practice. Online learning within an international community can extend opportunities for developing professional knowledge and behaviours in the politics of community-based practice

    Genome-wide association and HLA fine-mapping studies identify risk loci and genetic pathways underlying allergic rhinitis

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    Allergic rhinitis is the most common clinical presentation of allergy, affecting 400 million people worldwide, with increasing incidence in westernized countries1,2. To elucidate the genetic architecture and understand the underlying disease mechanisms, we carried out a meta-analysis of allergic rhinitis in 59,762 cases and 152,358 controls of European ancestry and identified a total of 41 risk loci for allergic rhinitis, including 20 loci not previously associated with allergic rhinitis, which were confirmed in a replication phase of 60,720 cases and 618,527 controls. Functional annotation implicated genes involved in various immune pathways, and fine mapping of the HLA region suggested amino acid variants important for antigen binding. We further performed genome-wide association study (GWAS) analyses of allergic sensitization against inhalant allergens and nonallergic rhinitis, which suggested shared genetic mechanisms across rhinitis-related traits. Future studies of the identified loci and genes might identify novel targets for treatment and prevention of allergic rhinitis

    From Expert Discipline to Common Practice: A Vision and Research Agenda for Extending the Reach of Enterprise Modeling

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    The benefits of enterprise modeling (EM) and its contribution to organizational tasks are largely undisputed in business and information systems engineering. EM as a discipline has been around for several decades but is typically performed by a limited number of people in organizations with an affinity to modeling. What is captured in models is only a fragment of what ought to be captured. Thus, this research note argues that EM is far from its maximum potential. Many people develop some kind of model in their local practice without thinking about it consciously. Exploiting the potential of this “grass roots modeling” could lead to groundbreaking innovations. The aim is to investigate integration of the established practices of modeling with local practices of creating and using model-like artifacts of relevance for the overall organization. The paper develops a vision for extending the reach of EM, identifies research areas contributing to the vision and proposes elements of a future research Agenda

    Sialyllactose in Viral Membrane Gangliosides Is a Novel Molecular Recognition Pattern for Mature Dendritic Cell Capture of HIV-1

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    An accessible sialyllactose moiety on viral membrane gangliosides is shown to be essential for HIV-1 uptake into mature dendritic cells, thereby promoting viral transfer and infection of bystander CD4+ T lymphocytes
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