Toward mid-infrared, subdiffraction, spectral-mapping of human cells and tissue: SNIM (scanning near-field infrared microscopy) tip fabrication

Scanning near-field infrared microscopy (SNIM) potentially enables subdiffraction, broadband mid-infrared (MIR:3–25-μm wavelength range) spectral-mapping of human cells and tissue for real-time molecular sensing, with prospective use in disease diagnosis. SNIM requires an MIR-transmitting tip of small aperture for photon collection. Here, chalcogenide-glass optical fibers are reproducibly tapered at one end to form a MIR transmitting tip for SNIM. A wet-etching method is used to form the tip. The tapering sides of the tip are Al-coated. These Al-coated tapered-tips exhibit near-field power-confinement when acting either as the launch-end or exit-end of the MIR optical fiber. We report first time optimal cleaving of the end of the tapered tip using focused ion beam milling. A flat aperture is produced at the end of the tip, which is orthogonal to the fiber-axis and of controlled diameter. A FIB-cleaved aperture is used to collect MIR spectra of cells mounted on a transflection plate, under illumination of a synchrotron- generated wideband MIR beam

Assessing functional and structural cardiotoxicity in cultured human iPSC-cardiomyocytes in a single plate format

Présentation PosterInternational audienceA comprehensive profiling of cardiotoxicity early in drug discovery and development can aid in reducing late-stage attrition and establishing risk-mitigation strategies during clinical development. In most cases, multiple assay platforms and instrument-specified plate formats are required for this type of approach. In this study, we evaluated both functional and structural endpoints associated with cardiotoxicity in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) cultured in a single 384-well plate. We measured intracellular Ca2+ transit, caspase 3/7 activation and plasma membrane permeabilization sequentially in the same plate via a series of assay readouts. A set of cardiac ion channel modulators (dofetilide, sotalol, nifedipine and mexiletine) and chemotherapeutics (tamoxifen, nilotinib, sunitinib and doxorubicin) was tested at clinically relevant concentrations for effects on intracellular Ca 2+ transits after a short-term (30 minutes) exposure, and plasma membrane permeabilization and caspase 3/7 activation after a long-term (72 hours) exposure. Intracellular Ca2+ transits were monitored by fluorescent images taken with a high-speed camera in beating cardiomyocytes loaded with Cal520® Ca2+ dye, permeabilized plasma membrane (for dead-cell detection) was identified with live-stain DRAQ7TM nuclear dye and activation of caspase 3/7 was determined biochemically with the Caspase-Glo® 3/7 Assay kit. Multiple endpoints derived from Ca 2+ transits, including beat rate, calcium transit duration (CTD) measured at 30% or 90% from peak and corrected by inter-peak interval (IPI), along with CTD triangulation, beat rhythm, short- or long-term variability of CTD90 and IPI Poincaré plots, were used to assess drug effects on intracellular Ca2+ cycling and arrhythmogenicity. Increases in positive nuclear staining for DRAQ7TM and caspase 3/7 activity represented structural cardiotoxicity. We found that increased CTD triangulation, development of arrhythmic events and both the short- and long-term variability of CTD90 or IPI were robust indicators of functional effects. Positive nuclear staining for DRAQ7TM was a robust indicator of structural effects. Accordingly, dofetilide and sotalol were identified as primarily arrhythmogenic, doxorubicin was primarily structurally toxic, while nilotinib and sunitinib were both arrhythmogenic and structurally toxic. The use of these endpoints in a single plate format simplifies the cardiotoxicity assessment and does not require multiple cell plates for measurements

Genome-Wide Association Study of Susceptibility to Idiopathic Pulmonary Fibrosis

Rationale: Idiopathic pulmonary fibrosis (IPF) is a complex lung disease characterised by scarring of the lung that is believed to result from an atypical response to injury of the epithelium. Genome-wide association studies have reported signals of association implicating multiple pathways including host defence, telomere maintenance, signalling and cell-cell adhesion. Objectives: To improve our understanding of factors that increase IPF susceptibility by identifying previously unreported genetic associations. Methods and measurements: We conducted genome-wide analyses across three independent studies and meta-analysed these results to generate the largest genome-wide association study of IPF to date (2,668 IPF cases and 8,591 controls). We performed replication in two independent studies (1,456 IPF cases and 11,874 controls) and functional analyses (including statistical fine-mapping, investigations into gene expression and testing for enrichment of IPF susceptibility signals in regulatory regions) to determine putatively causal genes. Polygenic risk scores were used to assess the collective effect of variants not reported as associated with IPF. Main results: We identified and replicated three new genome-wide significant (P<5×10−8) signals of association with IPF susceptibility (associated with altered gene expression of KIF15, MAD1L1 and DEPTOR) and confirmed associations at 11 previously reported loci. Polygenic risk score analyses showed that the combined effect of many thousands of as-yet unreported IPF susceptibility variants contribute to IPF susceptibility. Conclusions: The observation that decreased DEPTOR expression associates with increased susceptibility to IPF, supports recent studies demonstrating the importance of mTOR signalling in lung fibrosis. New signals of association implicating KIF15 and MAD1L1 suggest a possible role of mitotic spindle-assembly genes in IPF susceptibility

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

Introduction: The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures. Methods: In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025. Findings: Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2–6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p&lt;0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5–5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p&lt;0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4–10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p&lt;0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32–4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP &gt;5mg/L, OR 3·55 [1·23–11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation. Interpretation: After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification

Reading Poetry: An Introduction. 2nd Edition

Reading Poetry is a comprehensive, accessible and extremely effective guide to the arts of reading, analysing and enjoying poetry. From the opening chapter, which examines assumptions about what poetry might be, successive chapters map a path that takes the reader from the basics of simple appreciation to an understanding of the often complex theoretical and historical contexts that enrich any appreciation of poetry. While emphasising the importance of close textual analysis - or reading in slow motion - the authors clearly demonstrate how an understanding of form, language and context can combine to produce sophisticated and original responses to all types of poetry. The second edition of this best-selling book includes a number of developments that make it more user-friendly for the individual reader and more suitable as a stand-alone textbook for university courses in poetry. The poetic examples have been increased to 150, ranging from the 14th to the 21st century, and clear guidance is provided on further reading in footnotes and an expanded bibliography. This edition includes a new chapter on Post-Colonial Poetry,a substantial increase in the number of end-of-chapter exercises, and a comprehensive Glossary of Poetic Terms. The aim of the book is preserved from that of the first edition, namely to enhance readers' literary and scholarly competence, and to restore enjoyment to the reading of poetry

[Book Review] Climate change in Africa, by Camilla Toulmin

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