692 research outputs found

    CD98hc facilitates B cell proliferation and adaptive humoral immunity.

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    The proliferation of antigen-specific lymphocytes and resulting clonal expansion are essential for adaptive immunity. We report here that B cell-specific deletion of the heavy chain of CD98 (CD98hc) resulted in lower antibody responses due to total suppression of B cell proliferation and subsequent plasma cell formation. Deletion of CD98hc did not impair early B cell activation but did inhibit later activation of the mitogen-activated protein kinase Erk1/2 and downregulation of the cell cycle inhibitor p27. Reconstitution of CD98hc-deficient B cells with CD98hc mutants showed that the integrin-binding domain of CD98hc was required for B cell proliferation but that the amino acid-transport function of CD98hc was dispensable for this. Thus, CD98hc supports integrin-dependent rapid proliferation of B cells. We propose that the advantage of adaptive immunity favored the appearance of CD98hc in vertebrates

    Creating a positive casual academic identity through change and loss

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    Neoliberalism has significantly impacted higher education institutes across the globe by increasing the number of casual and non-continuing academic positions. Insecure employments conditions have not only affected the well-being of contingent staff, but it has also weakened the democratic, intellectual and moral standing of academic institutions. This chapter provides one practitioner’s account of the challenges of casual work, but rather than dwelling on the negativities, it outlines the potential richness of an identity based on insecurity and uncertainty. This exploration draws on the literature of retired academics and identity theory to illustrate the potential generative spaces within an undefined and incoherent identity

    Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

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    Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

    CHD7 Mutational Analysis and Clinical Considerations for Auditory Rehabilitation in Deaf Patients with CHARGE Syndrome

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    BACKGROUND: Otologic manifestations are one of the most consistent findings of CHARGE syndrome found in more than 90%. Since genetic analysis of the CHD7 gene has rarely been performed in previous reports dealing with ear abnormalities, the genotypic spectrum of CHD7 mutations was analyzed in deaf patients with CHARGE syndrome, and the clinical considerations concerning auditory rehabilitation were investigated. METHODS: Nine Korean patients with CHARGE syndrome showing profound hearing loss and semicircular canal aplasia were included. All 38 exons of CHD7 were analyzed by direct sequencing. For splice site variations, in silico and exon-trapping analyses were performed to verify the pathogenicity of nucleotide variations. Clinical features and the outcome of auditory rehabilitation were also analyzed. RESULTS: Eight of 9 patients revealed alterations of the CHD7 gene including 3 frameshift, 2 nonsense, 2 splice site, and 1 missense mutations. Five of 9 patients were clinically diagnosed as atypical CHARGE syndrome but demonstrated various mutations of the CHD7 gene. One familial case showed intra-familial variability. Radiologic findings suggesting cochleovestibular nerve deficiency were identified in most of the patients. Of the 8 patients who underwent cochlear implantation, 5 patients demonstrated favorable outcome. Larger diameter of the cochleovestibular nerve on imaging and absence of severe mental retardation were factors related to better outcome after cochlear implantation rather than the type of CHD7 mutations. Auditory brainstem implantation was performed in two patients who did not benefit from cochlear implantation. CONCLUSIONS: Genetic analysis of the CHD7 gene should be performed in cases with semicircular canal aplasia even when other typical features of CHARGE syndrome are absent. For auditory rehabilitation in CHARGE syndrome, cochlear implantation should be strongly recommended in selected cases with favorable prognostic factors. Auditory brainstem implantation may be a viable option in patients with CHARGE syndrome who have failed to benefit from cochlear implantation

    Factors associated with commencing smoking in 12-year-old students in Catalonia (Spain): a cross-sectional population-based study

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    <p>Abstract</p> <p>Background</p> <p>Over the last decade notable progress has been made in developed countries on monitoring smoking although experimenting with cigarettes and smoking in young people remains a serious public health problem. This paper reports a cross-sectional study at the beginning of the 3-year follow-up community study TA_BES. The aim was to study the prevalence of smoking in addition to determining predictive factors for when smoking commences in a representative population of 12-year-old first year compulsory secondary education students.</p> <p>Methods</p> <p>Twenty-nine secondary schools (N = 29) from an area of Catalonia participated in the study. In these schools 2245 students answered a questionnaire to study the attitudes, behaviors, and tobacco consumption in the subject's surrounding circle and family in relation to smoking; carbon monoxide measurements were taken by means of co-oximetry on 2 different occasions. A smoker was defined as a student who had smoked daily or occasionally in the last 30 days. For non-smokers the criteria of not considering was set up for those who answered that in the future they would not be smokers and considering those who answered that they did not rule out becoming a smoker in the future.</p> <p>Results</p> <p>Among the total 2245 students included in the analysis 157(7%) were classified as smokers. Among non-smokers we differentiated between those not considering smoking 1757 (78.3%) and those considering smoking 288 (12.8%).</p> <p>Age is among the factors related to commencing smoking. The risk of becoming a smoker increases 2.27 times/year. The influence of the group of friends with a very high risk for boys OR 149.5 and lower, albeit high, in girls OR 38.1. Tobacco consumption of parents produces different effects in young people. A smoking father does not produce alterations in the smoking behavior of young people. However having a smoking mother or former smoking is a risk factor for boys and a protective factor for girls.</p> <p>We detected a gradual risk of becoming a smoker by means of the co-oximetry test. A boy/girl with a test between 6 p.p.m and 10 p.p.m increased the probability of smoking by 2.29 and co-oximetry values > 10 p.p.m multiplied the risk 4 times over.</p> <p>Conclusions</p> <p>Results indicate that the age of commencing smoking is maintained in spite of prevalence having decreased in the last few years. The risk factors identified should be used to involve families and the educational community by offering them tobacco weaning programmes.</p

    Rapid response of Helheim Glacier in Greenland to climate variability over the past century

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    Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature Geoscience 5 (2012): 37-41, doi:10.1038/ngeo1349.During the early 2000s the Greenland Ice Sheet experienced the largest ice mass loss observed on the instrumental record1, largely as a result of the acceleration, thinning and retreat of major outlet glaciers in West and Southeast Greenland2-5. The quasi-simultaneous change in the glaciers suggests a common climate forcing and increasing air6 and ocean7-8 temperatures have been indicated as potential triggers. Here, we present a new record of calving activity of Helheim Glacier, East Greenland, extending back to c. 1890 AD. This record was obtained by analysing sedimentary deposits from Sermilik Fjord, where Helheim Glacier terminates, and uses the annual deposition of sand grains as a proxy for iceberg discharge. The 120 year long record reveals large fluctuations in calving rates, but that the present high rate was reproduced only in the 1930s. A comparison with climate indices indicates that high calving activity coincides with increased Atlantic Water and decreased Polar Water influence on the shelf, warm summers and a negative phase of the North Atlantic Oscillation. Our analysis provides evidence that Helheim Glacier responds to short-term (3-10 years) large-scale oceanic and atmospheric fluctuations.This study has been supported by Geocenter Denmark in financial support to the SEDIMICE project. CSA was supported by the Danish Council for Independent Research│Nature and Universe (Grant no. 09-064954/FNU). FSt was supported by NSF ARC 0909373 and by WHOI’s Ocean and Climate Change Institute and MHRI was supported by the Danish Agency for Science, Technology and Innovation.2012-06-1

    A First Generation BAC-Based Physical Map of the Asian Seabass (Lates calcarifer)

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    BACKGROUND: The Asian seabass (Lates calcarifer) is an important marine foodfish species in Southeast Asia and Australia. Genetic improvement of this species has been achieved to some extent through selective breeding programs since 1990s. Several genomic tools such as DNA markers, a linkage map, cDNA and BAC libraries have been developed to assist selective breeding. A physical map is still lacking, although it is essential for positional cloning of genes located in quantitative trait loci (QTL) and assembly of whole genome sequences. METHODOLOGY/PRINCIPAL FINDINGS: A genome-wide physical map of the Asian seabass was constructed by restriction fingerprinting of 38,208 BAC clones with SNaPshot HICF FPC technique. A total of 30,454 were assembled into 2,865 contigs. The physical length of the assembled contigs summed up to 665 Mb. Analyses of some contigs using different methods demonstrated the reliability of the assembly. CONCLUSIONS/SIGNIFICANCE: The present physical map is the first physical map for Asian seabass. This physical map will facilitate the fine mapping of QTL for economically important traits and the positional cloning of genes located in QTL. It will also be useful for the whole genome sequencing and assembly. Detailed information about BAC-contigs and BAC clones are available upon request
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