28 research outputs found

    Engineering rotating apical-out airway organoid for assessing respiratory cilia motility

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    Motile cilia project from the airway apical surface and directly interface with inhaled external environment. Owing to cilia\u27s nanoscale dimension and high beating frequency, quantitative assessment of their motility remains a sophisticated task. Here we described a robust approach for reproducible engineering of apical-out airway organoid (AOAO) from a defined number of cells. Propelled by exterior-facing cilia beating, the mature AOAO exhibited stable rotational motion when surrounded by Matrigel. We developed a computational framework leveraging computer vision algorithms to quantify AOAO rotation and correlated it with the direct measurement of cilia motility. We further established the feasibility of using AOAO rotation to recapitulate and measure defective cilia motility caused by chemotherapy-induced toxicity and by CCDC39 mutations in cells from patients with primary ciliary dyskinesia. We expect our rotating AOAO model and the associated computational pipeline to offer a generalizable framework to expedite the modeling of and therapeutic development for genetic and environmental ciliopathies

    Effectiveness of biomarker-based exclusion of ventilator-acquired pneumonia to reduce antibiotic use (VAPrapid-2): study protocol for a randomised controlled trial.

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    BACKGROUND: Ventilator-acquired pneumonia (VAP) is a common reason for antimicrobial therapy in the intensive care unit (ICU). Biomarker-based diagnostics could improve antimicrobial stewardship through rapid exclusion of VAP. Bronchoalveloar lavage (BAL) fluid biomarkers have previously been shown to allow the exclusion of VAP with high confidence. METHODS/DESIGN: This is a prospective, multi-centre, randomised, controlled trial to determine whether a rapid biomarker-based exclusion of VAP results in fewer antibiotics and improved antimicrobial management. Patients with clinically suspected VAP undergo BAL, and VAP is confirmed by growth of a potential pathogen at [≥] 10(4) colony-forming units per millilitre (CFU/ml). Patients are randomised 1:1, to either a 'biomarker-guided recommendation on antibiotics' in which BAL fluid is tested for IL-1β and IL-8 in addition to routine microbiology testing, or to 'routine use of antibiotics' in which BAL undergoes routine microbiology testing only. Clinical teams are blinded to intervention until 6 hours after randomisation, when biomarker results are reported to the clinician. The primary outcome is a change in the frequency distribution of antibiotic-free days (AFD) in the 7 days following BAL. Secondary outcome measures include antibiotic use at 14 and 28 days; ventilator-free days; 28-day mortality and ICU mortality; sequential organ failure assessment (SOFA) at days 3, 7 and 14; duration of stay in critical care and the hospital; antibiotic-associated infections; and antibiotic-resistant pathogen cultures up to hospital discharge, death or 56 days. A healthcare-resource-utilisation analysis will be calculated from the duration of critical care and hospital stay. In addition, safety data will be collected with respect to performing BAL. A sample size of 210 will be required to detect a clinically significant shift in the distribution of AFD towards more patients having fewer antibiotics and therefore more AFD. DISCUSSION: This trial will test whether a rapid biomarker-based exclusion of VAP results in rapid discontinuation of antibiotics and therefore improves antibiotic management in patients with suspected VAP. TRIAL REGISTRATION: ISRCTN65937227 . Registered on 22 August 2013. ClinicalTrials.gov, NCT01972425 . Registered on 24 October 2013

    Alpha 2 agonists for sedation to produce better outcomes from critical illness (A2B Trial): protocol for a multicentre phase 3 pragmatic clinical and cost-effectiveness randomised trial in the UK

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    Introduction: Almost all patients receiving mechanical ventilation (MV) in intensive care units (ICUs) require analgesia and sedation. The most widely used sedative drug is propofol, but there is uncertainty whether alpha2-agonists are superior. The alpha 2 agonists for sedation to produce better outcomes from critical illness (A2B) trial aims to determine whether clonidine or dexmedetomidine (or both) are clinically and cost-effective in MV ICU patients compared with usual care.Methods and analysis: Adult ICU patients within 48 hours of starting MV, expected to require at least 24 hours further MV, are randomised in an open-label three arm trial to receive propofol (usual care) or clonidine or dexmedetomidine as primary sedative, plus analgesia according to local practice. Exclusions include patients with primary brain injury; postcardiac arrest; other neurological conditions; or bradycardia. Unless clinically contraindicated, sedation is titrated using weight-based dosing guidance to achieve a Richmond-Agitation-Sedation score of −2 or greater as early as considered safe by clinicians. The primary outcome is time to successful extubation. Secondary ICU outcomes include delirium and coma incidence/duration, sedation quality, predefined adverse events, mortality and ICU length of stay. Post-ICU outcomes include mortality, anxiety and depression, post-traumatic stress, cognitive function and health-related quality of life at 6-month follow-up. A process evaluation and health economic evaluation are embedded in the trial.The analytic framework uses a hierarchical approach to maximise efficiency and control type I error. Stage 1 tests whether each alpha2-agonist is superior to propofol. If either/both interventions are superior, stages 2 and 3 testing explores which alpha2-agonist is more effective. To detect a mean difference of 2 days in MV duration, we aim to recruit 1437 patients (479 per group) in 40–50 UK ICUs.Ethics and dissemination: The Scotland A REC approved the trial (18/SS/0085). We use a surrogate decision-maker or deferred consent model consistent with UK law. Dissemination will be via publications, presentations and updated guidelines

    Multiexcitation Fluorogenic Labeling of Surface, Intracellular, and Total Protein Pools in Living Cells

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    Malachite green (MG) is a fluorogenic dye that shows fluorescence enhancement upon binding to its engineered cognate protein, a fluorogen activating protein (FAP). Energy transfer donors such as cyanine and rhodamine dyes have been conjugated with MG to modify the spectral properties of the fluorescent complexes, where the donor dyes transfer energy through Förster resonance energy transfer to the MG complex resulting in binding-conditional fluorescence emission in the far-red region. In this article, we use a violet-excitable dye as a donor to sensitize the far-red emission of the MG-FAP complex. Two blue emitting fluorescent coumarin dyes were coupled to MG and evaluated for energy transfer to the MG-FAP complex via its secondary excitation band. 6,8-Difluoro-7-hydroxycoumarin-3-carboxylic acid (Pacific blue, PB) showed the most efficient energy transfer and maximum brightness in the far-red region upon violet (405 nm) excitation. These blue-red (BluR) tandem dyes are spectrally varied from other tandem dyes and are able to produce fluorescence images of the MG-FAP complex with a large Stokes shift (>250 nm). These dyes are cell-permeable and are used to label intracellular proteins. Used together with a cell-impermeable hexa-Cy3-MG (HCM) dye that labels extracellular proteins, we are able to visualize extracellular, intracellular, and total pools of cellular protein using one fluorogenic tag that combines with distinct dyes to effect different spectral characteristics

    High-Content Surface and Total Expression siRNA Kinase Library Screen with VX-809 Treatment Reveals Kinase Targets that Enhance F508del-CFTR Rescue

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    The most promising F508del-CFTR corrector, VX-809, has been unsuccessful as an effective, stand-alone treatment for CF patients, but the rescue effect in combination with other drugs may confer an acceptable level of therapeutic benefit. Targeting cellular factors that modify trafficking may act to enhance the cell surface density of F508-CFTR with VX-809 correction. Our goal is to identify druggable kinases that enhance F508del-CFTR rescue and stabilization at the cell surface beyond that achievable with the VX-809 corrector alone. To achieve this goal, we implemented a new high-throughput screening paradigm that quickly and quantitatively measures surface density and total protein in the same cells. This allowed for rapid screening for increased surface targeting and proteostatic regulation. The assay utilizes fluorogen-activating-protein (FAP) technology with cell excluded and cell permeant fluorogenic dyes in a quick, wash-free fluorescent plate reader format on live cells to first measure F508del-CFTR expressed on the surface and then the total amount of F508del-CFTR protein present. To screen for kinase targets, we used Dharmacon’s ON-TARGET<i>plus</i> SMARTpool siRNA Kinase library (715 target kinases) with and without 10 μM VX-809 treatment in triplicate at 37 °C. We identified several targets that had a significant interaction with VX-809 treatment in enhancing surface density with siRNA knockdown. Select small-molecule inhibitors of the kinase targets demonstrated augmented surface expression with VX-809 treatment
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