1,606 research outputs found

    Cone photoreceptor definition on adaptive optics retinal imaging

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    To quantitatively analyse cone photoreceptor matrices on images captured on an adaptive optics (AO) camera and assess their correlation to well-established parameters in the retinal histology literature

    Awe and Wonder in Scientific Practice: Implications for the Relationship Between Science and Religion

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    This paper examines the role of awe and wonder in scientific practice. Drawing on evidence from psychological research and the writings of scientists and science communicators, I argue that awe and wonder play a crucial role in scientific discovery. They focus our attention on the natural world, encourage open-mindedness, diminish the self (particularly feelings of self-importance), help to accord value to the objects that are being studied, and provide a mode of understanding in the absence of full knowledge. I will flesh out implications of the role of awe and wonder in scientific discovery for debates on the relationship between science and religion. Abraham Heschel argued that awe and wonder are religious emotions because they reduce our feelings of self-importance, and thereby help to cultivate the proper reverent attitude towards God. Yet metaphysical naturalists such as Richard Dawkins insist that awe and wonder need not lead to any theistic commitments for scientists. The awe some scientists experience can be regarded as a form of non-theistic spirituality, which is neither a reductive naturalism nor theism. I will attempt to resolve the tension between these views by identifying some common ground

    Identification and Correction of Mechanisms Underlying Inherited Blindness in Human iPSC-Derived Optic Cups

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    Leber congenital amaurosis (LCA) is an inherited retinal dystrophy that causes childhood blindness. Photoreceptors are especially sensitive to an intronic mutation in the cilia-related gene CEP290, which causes missplicing and premature termination, but the basis of this sensitivity is unclear. Here, we generated differentiated photoreceptors in three-dimensional optic cups and retinal pigment epithelium (RPE) from iPSCs with this common CEP290 mutation to investigate disease mechanisms and evaluate candidate therapies. iPSCs differentiated normally into RPE and optic cups, despite abnormal CEP290 splicing and cilia defects. The highest levels of aberrant splicing and cilia defects were observed in optic cups, explaining the retinal-specific manifestation of this CEP290 mutation. Treating optic cups with an antisense morpholino effectively blocked aberrant splicing and restored expression of full-length CEP290, restoring normal cilia-based protein trafficking. These results provide a mechanistic understanding of the retina-specific phenotypes in CEP290 LCA patients and potential strategies for therapeutic intervention

    Anti-influenza hyperimmune intravenous immunoglobulin for adults with influenza A or B infection (FLU-IVIG): a double-blind, randomised, placebo-controlled trial

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    BACKGROUND: Since the 1918 influenza pandemic, non-randomised studies and small clinical trials have suggested that convalescent plasma or anti-influenza hyperimmune intravenous immunoglobulin (hIVIG) might have clinical benefit for patients with influenza infection, but definitive data do not exist. We aimed to evaluate the safety and efficacy of hIVIG in a randomised controlled trial. METHODS: This randomised, double-blind, placebo-controlled trial was planned for 45 hospitals in Argentina, Australia, Denmark, Greece, Mexico, Spain, Thailand, UK, and the USA over five influenza seasons from 2013-14 to 2017-18. Adults (≥18 years of age) were admitted for hospital treatment with laboratory-confirmed influenza A or B infection and were randomly assigned (1:1) to receive standard care plus either a single 500-mL infusion of high-titre hIVIG (0·25 g/kg bodyweight, 24·75 g maximum; hIVIG group) or saline placebo (placebo group). Eligible patients had a National Early Warning score of 2 points or greater at the time of screening and their symptoms began no more than 7 days before randomisation. Pregnant and breastfeeding women were excluded, as well as any patients for whom the treatment would present a health risk. Separate randomisation schedules were generated for each participating clinical site using permuted block randomisation. Treatment assignments were obtained using a web-based application by the site pharmacist who then masked the solution for infusion. Patients and investigators were masked to study treatment. The primary endpoint was a six-category ordinal outcome of clinical status at day 7, ranging in severity from death to resumption of normal activities after discharge. The choice of day 7 was based on haemagglutination inhibition titres from a pilot study. It was analysed with a proportional odds model, using all six categories to estimate a common odds ratio (OR). An OR greater than 1 indicated that, for a given category, patients in the hIVIG group were more likely to be in a better category than those in the placebo group. Prespecified primary analyses for safety and efficacy were based on patients who received an infusion and for whom eligibility could be confirmed. This trial is registered with ClinicalTrials.gov, NCT02287467. FINDINGS: 313 patients were enrolled in 34 sites between Dec 11, 2014, and May 28, 2018. We also used data from 16 patients enrolled at seven of the 34 sites during the pilot study between Jan 15, 2014, and April 10, 2014. 168 patients were randomly assigned to the hIVIG group and 161 to the placebo group. 21 patients were excluded (12 from the hIVIG group and 9 from the placebo group) because they did not receive an infusion or their eligibility could not be confirmed. Thus, 308 were included in the primary analysis. hIVIG treatment produced a robust rise in haemagglutination inhibition titres against influenza A and smaller rises in influenza B titres. Based on the proportional odds model, the OR on day 7 was 1·25 (95% CI 0·79-1·97; p=0·33). In subgroup analyses for the primary outcome, the OR in patients with influenza A was 0·94 (0·55-1·59) and was 3·19 (1·21-8·42) for those with influenza B (interaction p=0·023). Through 28 days of follow-up, 47 (30%) of 156 patients in the hIVIG group and in 45 (30%) of 152 patients in the placebo group had the composite safety outcome of death, a serious adverse event, or a grade 3 or 4 adverse event (hazard ratio [HR] 1·06, 95% CI 0·70-1·60; p=0·79). Six (4%) patients in the hIVIG group and five (3%) in the placebo group died, but these deaths were not necessarily related to treatment. INTERPRETATION: When administered alongside standard care (most commonly oseltamivir), hIVIG was not superior to placebo for adults hospitalised with influenza infection. By contrast with our prespecified subgroup hypothesis that hIVIG would result in more favourable responses in patients with influenza A than B, we found the opposite effect. The clinical benefit of hIVIG for patients with influenza B is supported by antibody affinity analyses, but confirmation is warranted. FUNDING: NIAID and NIH. Partial support was provided by the Medical Research Council (MRC_UU_12023/23) and the Danish National Research Foundation

    Lack of MHC class I surface expression on neoplastic cells and poor activation of the secretory pathway of cytotoxic cells in oral squamous cell carcinomas

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    Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells use the secretory pathway of perforin/granzymes to kill their target cells. In contrast to NK cells, CTL responses are MHC class I restricted. In this study we analysed the relative activation of CTL and NK cells in relation with MHC class I expression on oral squamous cell carcinomas (OSCCs). MHC class I expression was investigated in 47 OSCCs by immunohistochemistry using HCA2, HC10 and β2-m antibodies. The presence of CTLs, NK cells, and its activation, was investigated in 21 of these OSCCs using respectively, CD8, CD57 and GrB7 antibodies. The Q-Prodit measuring system was used for quantification of cytotoxic cells. All OSCCs showed weak or absent staining of β2-m on the cell surface. The absence of β2-m was significantly associated with absent expression of MHC class I heavy chain as detected by HC10 antibody (P = 0.004). In tumour infiltrates CTLs always outnumbered NK cells, as reflected by the ratio CD57/CD8 being always inferior to one (mean: 0.19; SD: 0.15). The proportion of activated cytotoxic cells as detected by granzyme B expression was generally low (mean: 8.6%; SD 8.9). A clear correlation between MHC class I expression and the relative proportion of NK cells/CTLs was not found. This study shows that the majority of OSCCs show weak or absent expression of MHC class I molecules on the cell surface, possibly due to alterations in the normal β2-m pathway. The low proportion of granzyme B-positive CTLs/NK cells indicates that the secretory pathway of cytotoxicity is poor in these patients. The lack of correlation between MHC class I expression and CTL/NK cell activation as detected by granzyme B expression suggests that, next to poor antigen presentation, also local factors seem to determine the final outcome of the cytotoxic immune response. © 1999 Cancer Research Campaig

    The CEACAM1 expression is decreased in the liver of severely obese patients with or without diabetes

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    <p>Abstract</p> <p>Background</p> <p>Type 2 diabetes is mainly caused by insulin resistance. The carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is an important candidate for causing insulin resistance.</p> <p>Methods</p> <p>The CEACAM1 expression was evaluated immunohistochemically in the liver tissues of 99 severely obese or non-obese subjects with or without diabetes. The CEACAM1 expression was classified into two categories: a normal expression or a decreased expression.</p> <p>Results</p> <p>The CEACAM1 expression was markedly decreased in the hepatocytes with macrovesicular steatosis. A decreased CEACAM1 expression was noted in 29 (29%) of 99 cases. The incidence of a decreased CEACAM1 expression was significantly higher in high grade fatty liver as well as severe obesity with or without diabetes (p < 0.05). The incidence of a decreased CEACAM1 expression was not different between the diabetic and non-diabetic groups.</p> <p>Conclusions</p> <p>This data supports that a decreased CEACAM1 expression is related to obesity and a fatty liver.</p
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