ABSTRACT
Transcription factors (TFs) regulate gene expression by binding to specific consensus motifs within the local chromatin context. The mechanisms by which TFs navigate the nuclear environment as they search for binding sites remain unclear. Here, we used single-molecule tracking and machine-learning-based classification to directly measure the nuclear mobility of the glucocorticoid receptor (GR) in live cells. We revealed two distinct and dynamic low-mobility populations. One accounts for specific binding to chromatin, while the other represents a confinement state that requires an intrinsically disordered region (IDR), implicated in liquid-liquid condensate subdomains. Further analysis showed that the dwell times of both subpopulations follow a power-law distribution, consistent with a broad distribution of affinities on the GR cistrome and interactome. Together, our data link IDRs with a confinement state that is functionally distinct from specific chromatin binding and modulates the transcriptional output by increasing the local concentration of TFs at specific sites.
Subject(s)
Intrinsically Disordered Proteins/chemistry , Receptors, Glucocorticoid/chemistry , Transcription Factors/chemistry , Animals , Female , Intrinsically Disordered Proteins/genetics , Intrinsically Disordered Proteins/metabolism , Mice , Rats , Receptors, Glucocorticoid/genetics , Receptors, Glucocorticoid/metabolism , Transcription Factors/genetics , Transcription Factors/metabolismABSTRACT
Genes are transcribed in a discontinuous pattern referred to as RNA bursting, but the mechanisms regulating this process are unclear. Although many physiological signals, including glucocorticoid hormones, are pulsatile, the effects of transient stimulation on bursting are unknown. Here we characterize RNA synthesis from single-copy glucocorticoid receptor (GR)-regulated transcription sites (TSs) under pulsed (ultradian) and constant hormone stimulation. In contrast to constant stimulation, pulsed stimulation induces restricted bursting centered around the hormonal pulse. Moreover, we demonstrate that transcription factor (TF) nuclear mobility determines burst duration, whereas its bound fraction determines burst frequency. Using 3D tracking of TSs, we directly correlate TF binding and RNA synthesis at a specific promoter. Finally, we uncover a striking co-bursting pattern between TSs located at proximal and distal positions in the nucleus. Together, our data reveal a dynamic interplay between TF mobility and RNA bursting that is responsive to stimuli strength, type, modality, and duration.
Subject(s)
Glucocorticoids/pharmacology , Promoter Regions, Genetic , RNA/biosynthesis , Receptors, Glucocorticoid/metabolism , Transcription Initiation Site , Transcription, Genetic/drug effects , Animals , Mice , RNA/geneticsABSTRACT
The molecular basis for p53-mediated tumor suppression remains unclear. Here, to elucidate mechanisms of p53 tumor suppression, we use knockin mice expressing an allelic series of p53 transcriptional activation mutants. Microarray analysis reveals that one mutant, p53(25,26), is severely compromised for transactivation of most p53 target genes, and, moreover, p53(25,26) cannot induce G(1)-arrest or apoptosis in response to acute DNA damage. Surprisingly, p53(25,26) retains robust activity in senescence and tumor suppression, indicating that efficient transactivation of the majority of known p53 targets is dispensable for these pathways. In contrast, the transactivation-dead p53(25,26,53,54) mutant cannot induce senescence or inhibit tumorigenesis, like p53 nullizygosity. Thus, p53 transactivation is essential for tumor suppression but, intriguingly, in association with a small set of novel p53 target genes. Together, our studies distinguish the p53 transcriptional programs involved in acute DNA-damage responses and tumor suppression-a critical goal for designing therapeutics that block p53-dependent side effects of chemotherapy without compromising p53 tumor suppression.
Subject(s)
DNA Repair , Tumor Suppressor Protein p53/metabolism , Animals , Apoptosis , Cell Cycle , Cellular Senescence , DNA Damage , Gene Knock-In Techniques , Humans , Mice , Mutation , Neoplasms/metabolism , Protein Structure, Tertiary , Transcriptional Activation , Tumor Suppressor Protein p53/chemistry , Tumor Suppressor Protein p53/geneticsABSTRACT
The glucocorticoid receptor (GR), like other eukaryotic transcription factors, regulates gene expression by interacting with chromatinized DNA response elements. Photobleaching experiments in living cells indicate that receptors transiently interact with DNA on the time scale of seconds and predict that the response elements may be sparsely occupied on average. Here, we show that the binding of one receptor at the glucocorticoid response element (GRE) does not reduce the steady-state binding of another receptor variant to the same GRE. Mathematical simulations reproduce this noncompetitive state using short GR/GRE residency times and relatively long times between DNA binding events. At many genomic sites where GR binding causes increased chromatin accessibility, concurrent steady-state binding levels for the variant receptor are actually increased, a phenomenon termed assisted loading. Temporally sparse transcription factor-DNA interactions induce local chromatin reorganization, resulting in transient access for binding of secondary regulatory factors.
Subject(s)
Chromatin Assembly and Disassembly , Receptors, Glucocorticoid/metabolism , Response Elements , Adenosine Triphosphate/metabolism , Animals , Cell Line, Tumor , Mammary Tumor Virus, Mouse , Mice , Models, Biological , Monte Carlo Method , Nucleosomes/metabolism , Receptors, Estrogen/metabolism , Regulatory Sequences, Nucleic Acid , Transcription Factors/metabolismABSTRACT
BACKGROUND: Diffuse coronary artery disease affects the safety and efficacy of percutaneous coronary intervention (PCI). Pathophysiologic coronary artery disease patterns can be quantified using fractional flow reserve (FFR) pullbacks incorporating the pullback pressure gradient (PPG) calculation. This study aimed to establish the capacity of PPG to predict optimal revascularization and procedural outcomes. METHODS: This prospective, investigator-initiated, single-arm, multicenter study enrolled patients with at least one epicardial lesion with an FFR ≤0.80 scheduled for PCI. Manual FFR pullbacks were used to calculate PPG. The primary outcome of optimal revascularization was defined as an FFR ≥0.88 after PCI. RESULTS: A total of 993 patients with 1044 vessels were included. The mean FFR was 0.68±0.12, PPG 0.62±0.17, and the post-PCI FFR was 0.87±0.07. PPG was significantly correlated with the change in FFR after PCI (r=0.65 [95% CI, 0.61-0.69]; P<0.001) and demonstrated excellent predictive capacity for optimal revascularization (area under the receiver operating characteristic curve, 0.82 [95% CI, 0.79-0.84]; P<0.001). FFR alone did not predict revascularization outcomes (area under the receiver operating characteristic curve, 0.54 [95% CI, 0.50-0.57]). PPG influenced treatment decisions in 14% of patients, redirecting them from PCI to alternative treatment modalities. Periprocedural myocardial infarction occurred more frequently in patients with low PPG (<0.62) compared with those with focal disease (odds ratio, 1.71 [95% CI, 1.00-2.97]). CONCLUSIONS: Pathophysiologic coronary artery disease patterns distinctly affect the safety and effectiveness of PCI. PPG showed an excellent predictive capacity for optimal revascularization and demonstrated added value compared with an FFR measurement. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04789317.
Subject(s)
Coronary Artery Disease , Fractional Flow Reserve, Myocardial , Percutaneous Coronary Intervention , Humans , Percutaneous Coronary Intervention/adverse effects , Coronary Artery Disease/physiopathology , Coronary Artery Disease/therapy , Female , Male , Aged , Middle Aged , Prospective Studies , Treatment OutcomeABSTRACT
Charge density waves (CDWs) have been observed in nearly all families of copper-oxide superconductors. But the behavior of these phases across different families has been perplexing. In La-based cuprates, the CDW wavevector is an increasing function of doping, exhibiting the so-called Yamada behavior, while in Y- and Bi-based materials the behavior is the opposite. Here, we report a combined resonant soft X-ray scattering (RSXS) and neutron scattering study of charge and spin density waves in isotopically enriched La1.8−xEu0.2SrxCuO4 over a range of doping 0.07≤x≤0.20. We find that the CDW amplitude is temperature independent and develops well above experimentally accessible temperatures. Further, the CDW wavevector shows a nonmonotonic temperature dependence, exhibiting Yamada behavior at low temperature with a sudden change occurring near the spin ordering temperature. We describe these observations using a LandauGinzburg theory for an incommensurate CDW in a metallic system with a finite charge compressibility and spin-CDW coupling. Extrapolating to high temperature, where the CDW amplitude is small and spin order is absent, our analysis predicts a decreasing wavevector with doping, similar to Y and Bi cuprates. Our study suggests that CDW order in all families of cuprates forms by a common mechanism.
ABSTRACT
PURPOSE: To determine early endophthalmitis incidence and risk factors after glaucoma surgeries in the Medicare population. DESIGN: Retrospective, longitudinal study. PARTICIPANTS: Medicare Fee-for-Service (FFS) and Medicare Advantage beneficiaries in the United States aged 65 years or older undergoing glaucoma surgery. METHODS: Medicare claims were used to identify all patients who underwent glaucoma, cataract, or combined cataract/glaucoma surgery from 2016 to 2019. Endophthalmitis cases within 42 days of the index surgery were identified using the diagnostic codes. Multivariable logistic regression models were used to evaluate factors associated with postoperative endophthalmitis. MAIN OUTCOME MEASURES: The 42-day postoperative endophthalmitis incidence and risk factors associated with endophthalmitis after glaucoma surgery. RESULTS: There were 466 928 glaucoma surgeries, of which 310 823 (66.6%) were combined with cataract surgery. Cataract surgeries alone (n = 8 460 360) served as a reference group. Microinvasive glaucoma surgeries constituted most glaucoma procedures performed (67.8%), followed by trabeculectomy (14.0%), tube shunt (10.9%), and other procedures (7.3%). There were 572 cases of endophthalmitis identified after all glaucoma surgeries. Endophthalmitis incidence after glaucoma, combined cataract/glaucoma, and cataract surgeries alone was 1.5 (95% confidence interval [CI], 1.3-1.7), 1.1 (95% CI, 1.0-1.2), and 0.8 (95% CI, 0.8-0.8) per 1000 procedures, respectively. The median day of diagnosis of endophthalmitis was later for glaucoma surgeries (16.5 days) compared with combined cataract/glaucoma or cataract surgeries alone (8 and 6 days, respectively). Compared with microinvasive glaucoma surgery (MIGS), tube shunts were the only surgery type to be a significant risk factor for endophthalmitis for both stand-alone (adjusted odds ratio [aOR], 1.8, P = 0.002) and combined surgery (aOR 1.8, P = 0.047). The other risk factor for both stand-alone (aOR 1.1, P = 0.001) and combined (aOR 1.06, P = 0.049) surgeries was the Charlson Comorbidity Index (CCI). Age (aOR 1.03, P = 0.004) and male gender (1.46, P = 0.001) were significant risk factors for combined cataract and glaucoma surgeries. CONCLUSIONS: Compared with cataract surgery, early endophthalmitis incidence was higher for both glaucoma and combined cataract/glaucoma surgeries, with the highest incidence among tube shunts. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
Subject(s)
Cataract Extraction , Cataract , Endophthalmitis , Glaucoma , Humans , Aged , Male , United States/epidemiology , Medicare , Retrospective Studies , Incidence , Longitudinal Studies , Endophthalmitis/epidemiology , Endophthalmitis/etiology , Endophthalmitis/diagnosis , Cataract Extraction/adverse effects , Risk Factors , Cataract/complications , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Glaucoma/epidemiology , Glaucoma/surgery , Glaucoma/complicationsABSTRACT
Aberrant cortical development is a key feature of neurodevelopmental disorders such as autism spectrum disorder and schizophrenia. Both genetic and environmental risk factors are thought to contribute to defects in cortical development; however, model systems that can capture the dynamic process of human cortical development are not well established. To address this challenge, we combined recent progress in induced pluripotent stem cell differentiation with advanced live cell imaging techniques to establish a novel three-dimensional neurosphere assay, amenable to genetic and environmental modifications, to investigate key aspects of human cortical development in real-time. For the first time, we demonstrate the ability to visualise and quantify radial glial extension and neural migration through live cell imaging. To show proof-of-concept, we used our neurosphere assay to study the effect of a simulated viral infection, a well-established environmental risk factor in neurodevelopmental disorders, on cortical development. This was achieved by exposing neurospheres to the viral mimic, polyinosinic:polycytidylic acid. The results showed significant reductions in radial glia growth and neural migration in three independent differentiations. Further, fixed imaging highlighted reductions in the HOPX-expressing outer radial glia scaffolding and a consequent decrease in the migration of CTIP2-expressing cortical cells. Overall, our results provide new insight into how infections may exert deleterious effects on the developing human cortex.
Subject(s)
Autism Spectrum Disorder , Induced Pluripotent Stem Cells , Virus Diseases , Humans , Neurogenesis , Cell DifferentiationABSTRACT
The recent uptick in the approval of ex vivo cell therapies highlights the relevance of lentivirus (LV) as an enabling viral vector of modern medicine. As labile biologics, however, LVs pose critical challenges to industrial biomanufacturing. In particular, LV purification-currently reliant on filtration and anion-exchange or size-exclusion chromatography-suffers from long process times and low yield of transducing particles, which translate into high waiting time and cost to patients. Seeking to improve LV downstream processing, this study introduces peptides targeting the enveloped protein Vesicular stomatitis virus G (VSV-G) to serve as affinity ligands for the chromatographic purification of LV particles. An ensemble of candidate ligands was initially discovered by implementing a dual-fluorescence screening technology and a targeted in silico approach designed to identify sequences with high selectivity and tunable affinity. The selected peptides were conjugated on Poros resin and their LV binding-and-release performance was optimized by adjusting the flow rate, composition, and pH of the chromatographic buffers. Ligands GKEAAFAA and SRAFVGDADRD were selected for their high product yield (50%-60% of viral genomes; 40%-50% of HT1080 cell-transducing particles) upon elution in PIPES buffer with 0.65 M NaCl at pH 7.4. The peptide-based adsorbents also presented remarkable values of binding capacity (up to 3·109 TU per mL of resin, or 5·1011 vp per mL of resin, at the residence time of 1 min) and clearance of host cell proteins (up to a 220-fold reduction of HEK293 HCPs). Additionally, GKEAAFAA demonstrated high resistance to caustic cleaning-in-place (0.5 M NaOH, 30 min) with no observable loss in product yield and quality.
Subject(s)
Lentivirus , Vesicular Stomatitis , Animals , Humans , Lentivirus/genetics , Lentivirus/metabolism , HEK293 Cells , Peptides/metabolism , Vesiculovirus/genetics , Genetic VectorsABSTRACT
BACKGROUND: Heart failure (HF) with preserved or mildly reduced ejection fraction includes a heterogenous group of patients. Reclassification into distinct phenogroups to enable targeted interventions is a priority. This study aimed to identify distinct phenogroups, and compare phenogroup characteristics and outcomes, from electronic health record data. METHODS: 2,187 patients admitted to five UK hospitals with a diagnosis of HF and a left ventricular ejection fraction ≥ 40% were identified from the NIHR Health Informatics Collaborative database. Partition-based, model-based, and density-based machine learning clustering techniques were applied. Cox Proportional Hazards and Fine-Gray competing risks models were used to compare outcomes (all-cause mortality and hospitalisation for HF) across phenogroups. RESULTS: Three phenogroups were identified: (1) Younger, predominantly female patients with high prevalence of cardiometabolic and coronary disease; (2) More frail patients, with higher rates of lung disease and atrial fibrillation; (3) Patients characterised by systemic inflammation and high rates of diabetes and renal dysfunction. Survival profiles were distinct, with an increasing risk of all-cause mortality from phenogroups 1 to 3 (p < 0.001). Phenogroup membership significantly improved survival prediction compared to conventional factors. Phenogroups were not predictive of hospitalisation for HF. CONCLUSIONS: Applying unsupervised machine learning to routinely collected electronic health record data identified phenogroups with distinct clinical characteristics and unique survival profiles.
Subject(s)
Electronic Health Records , Heart Failure , Stroke Volume , Ventricular Function, Left , Humans , Heart Failure/physiopathology , Heart Failure/diagnosis , Heart Failure/mortality , Female , Male , Aged , Middle Aged , Risk Assessment , United Kingdom/epidemiology , Risk Factors , Prognosis , Aged, 80 and over , Databases, Factual , Unsupervised Machine Learning , Hospitalization , Time Factors , Comorbidity , Cause of Death , Phenotype , Data MiningABSTRACT
The glucocorticoid receptor (GR) is a ubiquitously expressed transcription factor that controls metabolic and homeostatic processes essential for life. Although numerous crystal structures of the GR ligand-binding domain (GR-LBD) have been reported, the functional oligomeric state of the full-length receptor, which is essential for its transcriptional activity, remains disputed. Here we present five new crystal structures of agonist-bound GR-LBD, along with a thorough analysis of previous structural work. We identify four distinct homodimerization interfaces on the GR-LBD surface, which can associate into 20 topologically different homodimers. Biologically relevant homodimers were identified by studying a battery of GR point mutants including crosslinking assays in solution, quantitative fluorescence microscopy in living cells, and transcriptomic analyses. Our results highlight the relevance of non-canonical dimerization modes for GR, especially of contacts made by loop L1-3 residues such as Tyr545. Our work illustrates the unique flexibility of GR's LBD and suggests different dimeric conformations within cells. In addition, we unveil pathophysiologically relevant quaternary assemblies of the receptor with important implications for glucocorticoid action and drug design.
Subject(s)
Glucocorticoids , Receptors, Glucocorticoid , Receptors, Glucocorticoid/metabolism , Ligands , Protein Binding , DimerizationABSTRACT
Orbital abscesses are rarely encountered in children younger than 1 year. The literature is limited to isolated case reports and a few case series. Most such cases are reported in infants born at term, with the earliest reported gestational birth age at 34 weeks. Children are more prone to orbital cellulitis compared with adults due to their underdeveloped sinuses and immature immune systems, and the origin is most commonly an ethmoid sinus infection. Orbital cellulitis secondary to dacryocystitis is even less common, with only a few isolated cases reported in infants and children. Herein, the authors present a case of a large extraconal and intraconal orbital abscess secondary to nasolacrimal duct obstruction and dacryocystitis in an extremely preterm infant. We discuss the diagnosis and multidisciplinary management of this challenging case.
Subject(s)
Dacryocystitis , Dacryocystorhinostomy , Lacrimal Duct Obstruction , Nasolacrimal Duct , Orbital Cellulitis , Infant , Adult , Child , Humans , Infant, Newborn , Lacrimal Duct Obstruction/diagnosis , Lacrimal Duct Obstruction/etiology , Orbital Cellulitis/etiology , Orbital Cellulitis/complications , Dacryocystorhinostomy/adverse effects , Infant, Extremely Premature , Abscess/complications , Abscess/diagnosis , Dacryocystitis/complications , Dacryocystitis/diagnosisABSTRACT
BACKGROUND: Measurement of fractional flow reserve (FFR) has an established role in guiding percutaneous coronary intervention. We tested the hypothesis that, at the stage of diagnostic invasive coronary angiography, systematic FFR-guided assessment of coronary artery disease would be superior, in terms of resource use and quality of life, to assessment by angiography alone. METHODS: We performed an open-label, randomized, controlled trial in 17 UK centers, recruiting 1100 patients undergoing invasive coronary angiography for the investigation of stable angina or non-ST-segment-elevation myocardial infarction. Patients were randomized to either angiography alone (angiography) or angiography with systematic pressure wire assessment of all epicardial vessels >2.25 mm in diameter (angiography+FFR). The coprimary outcomes assessed at 1 year were National Health Service hospital costs and quality of life. Prespecified secondary outcomes included clinical events. RESULTS: In the angiography+FFR arm, the median number of vessels examined was 4 (interquartile range, 3-5). The median hospital costs were similar: angiography, £4136 (interquartile range, £2613-£7015); and angiography+FFR, £4510 (£2721-£7415; P=0.137). There was no difference in median quality of life using the visual analog scale of the EuroQol EQ-5D-5L: angiography, 75 (interquartile range, 60-87); and angiography+FFR, 75 (interquartile range, 60-90; P=0.88). The number of clinical events was as follows: deaths, 5 versus 8; strokes, 3 versus 4; myocardial infarctions, 23 versus 22; and unplanned revascularizations, 26 versus 33, with a composite hierarchical event rate of 8.7% (48 of 552) for angiography versus 9.5% (52 of 548) for angiography+FFR (P=0.64). CONCLUSIONS: A strategy of systematic FFR assessment compared with angiography alone did not result in a significant reduction in cost or improvement in quality of life. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01070771.
Subject(s)
Coronary Artery Disease , Coronary Stenosis , Fractional Flow Reserve, Myocardial , Percutaneous Coronary Intervention , Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/therapy , Coronary Stenosis/diagnosis , Humans , Quality of Life , State Medicine , Treatment OutcomeABSTRACT
Double spike (DS) method has been extensively used in determining stable isotope ratios of many elements. However, challenges remain in obtaining high-precision isotope data for ultra-trace elements owing to the limitations of instrumental signal-to-noise ratios and the systematics of precision of DS-based measurements. Here, the DS-standard addition (SA) (DSSA) technique is proposed to improve measurements of isotope compositions of ultra-trace elements in natural samples. According to the U-shaped relationship between DS measurement uncertainty and the spike/sample ratio, theoretical equations and an error propagation model (EPM) were constructed comprehensively. In our method, a spiked secondary standard solution with a high, precisely known spike/sample ratio is mixed with samples such that the mixtures have spike/sample ratios within the optimal range. The abundances of the samples relative to the added standards (sample fraction; fspl) and the samples' isotope ratios can then be obtained exactly using a standard DS data reduction routine and the isotope binary mixing model. The accuracy and precision of the DSSA approach were verified by measurements of cadmium and molybdenum isotopes at as low as 5 ng levels. Compared with traditional DS measurements, the sample size for isotope analysis is reduced to 1/6-1/5 of the original with no loss of measurement precision. The optimal mixing range fspl = 0.15-0.5 is recommended. The DSSA method can be extended to isotope measurement of more than 33 elements where the DS method is applicable, especially for the ultra-trace elements such as platinum group and rare earth element isotopes.
ABSTRACT
This article provides a review of the recent development of biomimicking behaviors in active colloids. While the behavior of biological microswimmers is undoubtedly influenced by physics, it is frequently guided and manipulated by active sensing processes. Understanding the respective influences of the surrounding environment can help to engineering the desired response also in artificial swimmers. More often than not, the achievement of biomimicking behavior requires the understanding of both biological and artificial microswimmers swimming mechanisms and the parameters inducing mechanosensory responses. The comparison of both classes of microswimmers provides with analogies in their dependence on fuels, interaction with boundaries and stimuli induced motion, or taxis.
Subject(s)
Colloids , Swimming , MotionABSTRACT
INTRODUCTION: Diffuse disease has been identified as one of the main reasons leading to low post-PCI fractional flow reserve (FFR) and residual angina after PCI. Coronary pressure pullbacks allow for the evaluation of hemodynamic coronary artery disease (CAD) patterns. The pullback pressure gradient (PPG) is a novel metric that quantifies the distribution and magnitude of pressure losses along the coronary artery in a focal-to-diffuse continuum. AIM: The primary objective is to determine the predictive capacity of the PPG for post-PCI FFR. METHODS: This prospective, large-scale, controlled, investigator-initiated, multicenter study is enrolling patients with at least 1 lesion in a major epicardial vessel with a distal FFR ≤ 0.80 intended to be treated by PCI. The study will include 982 subjects. A standardized physiological assessment will be performed pre-PCI, including the online calculation of PPG from FFR pullbacks performed manually. PPG quantifies the CAD pattern by combining several parameters from the FFR pullback curve. Post-PCI physiology will be recorded using a standardized protocol with FFR pullbacks. We hypothesize that PPG will predict optimal PCI results (post-PCI FFR ≥ 0.88) with an area under the ROC curve (AUC) ≥ 0.80. Secondary objectives include patient-reported and clinical outcomes in patients with focal vs. diffuse CAD defined by the PPG. Clinical follow-up will be collected for up to 36 months, and an independent clinical event committee will adjudicate events. RESULTS: Recruitment is ongoing and is expected to be completed in the second half of 2023. CONCLUSION: This international, large-scale, prospective study with pre-specified powered hypotheses will determine the ability of the preprocedural PPG index to predict optimal revascularization assessed by post-PCI FFR. In addition, it will evaluate the impact of PPG on treatment decisions and the predictive performance of PPG for angina relief and clinical outcomes.
ABSTRACT
To identify changes in response to experimental intraocular pressure (IOP) elevation associated with the laminin α1 nmf223 mutation in mice. Laminin mutant (LM) mice (Lama1nmf223) and C57BL/6J (B6) mice in two age groups each (4-5 months and >1 year) underwent intracameral microbead injections to produce unilaterally elevated IOP. We assessed axonal transport block of immunofluorescently labeled amyloid precursor protein (APP) after 3 days and retinal ganglion cell (RGC) axon loss after 6 weeks. Light, electron and fluorescent microscopy was used to study baseline anatomic differences and effects of 3-day IOP elevation in younger LM mice. In younger mice of both LM and B6 strains, elevated IOP led to increased APP block in the retina, prelaminar optic nerve head (preONH), unmyelinated optic nerve (UON), and myelinated optic nerve (MON). APP blockade not significantly different between younger B6 and LM mouse strains. Older LM mice had greater APP accumulation in both control and glaucoma eyes compared to older B6, however, accumulation was not significantly greater in LM glaucoma eyes compared to LM controls. Axon loss at 6 weeks was 12.2% in younger LM and 18.7% in younger B6 mice (difference between strains, p = 0.22, Mann Whitney test). Untreated LM optic nerve area was lower compared to B6 (nerve area, p < 0.0001, t-test). Aberrant axon bundles, as well as defects, thickening and reduplication of pia mater, were seen in the optic nerves of younger LM mice. Axonal transport blockade significantly differed between old B6 and old LM mice in control and glaucoma eyes, and younger LM mice had abnormal axon paths and lower optic nerve area.
Subject(s)
Glaucoma , Optic Nerve , Animals , Mice , Axons/pathology , Disease Models, Animal , Glaucoma/genetics , Intraocular Pressure , Mice, Inbred C57BL , Optic Disk/pathology , Optic Nerve/pathology , Laminin/geneticsABSTRACT
BACKGROUND: We aimed to develop a machine learning algorithm to predict the presence of a culprit lesion in patients with out-of-hospital cardiac arrest (OHCA). METHODS: We used the King's Out-of-Hospital Cardiac Arrest Registry, a retrospective cohort of 398 patients admitted to King's College Hospital between May 2012 and December 2017. The primary outcome was the presence of a culprit coronary artery lesion, for which a gradient boosting model was optimized to predict. The algorithm was then validated in two independent European cohorts comprising 568 patients. RESULTS: A culprit lesion was observed in 209/309 (67.4%) patients receiving early coronary angiography in the development, and 199/293 (67.9%) in the Ljubljana and 102/132 (61.1%) in the Bristol validation cohorts, respectively. The algorithm, which is presented as a web application, incorporates nine variables including age, a localizing feature on electrocardiogram (ECG) (≥2 mm of ST change in contiguous leads), regional wall motion abnormality, history of vascular disease and initial shockable rhythm. This model had an area under the curve (AUC) of 0.89 in the development and 0.83/0.81 in the validation cohorts with good calibration and outperforms the current gold standard-ECG alone (AUC: 0.69/0.67/0/67). CONCLUSIONS: A novel simple machine learning-derived algorithm can be applied to patients with OHCA, to predict a culprit coronary artery disease lesion with high accuracy.
Subject(s)
Cardiopulmonary Resuscitation , Coronary Artery Disease , Out-of-Hospital Cardiac Arrest , Humans , Out-of-Hospital Cardiac Arrest/diagnosis , Out-of-Hospital Cardiac Arrest/therapy , Retrospective Studies , Treatment Outcome , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/therapy , Coronary Angiography , AlgorithmsABSTRACT
Social media is an arena of debate for contentious political and social topics. One conservation topic debated online is the acceptability of trophy hunting, a debate that has implications for national and international policy. We used a mixed-methods approach (grounded theory and quantitative clustering) to identify themes in the trophy hunting debate on Twitter. We examined commonly co-occurring categories that describe people's stances on trophy hunting. We identified 12 categories and 4 preliminary archetypes opposing trophy hunting-activism, scientific, condemning, and objecting-whose opposition derived from different moral reasoning. Few tweets (22) in our sample of 500 supported trophy hunting, whereas 350 opposed it. The debate was hostile; 7% of tweets in our sample were categorized as abusive. Online debates can be unproductive, and our findings may be important for stakeholders wishing to effectively engage in the trophy hunting debate on Twitter. More generally, we contend that because social media is increasingly influential, it is important to formally contextualize public responses to contentious conservation topics in order to aid communication of conservation evidence and to integrate diverse public perspectives in conservation practice.
Caracterización del debate sobre la cacería de trofeos en Twitter Resumen Las redes sociales son arenas de debate para temas políticos y sociales polémicos. Un tema de conservación que se debate en línea es la aceptación de la cacería de trofeos, cuya discusión tiene implicaciones políticas nacionales e internacionales. Usamos una estrategia de métodos mixtos (teoría fundamentada y datos cuantitativos agrupados) para identificar los temas en el debate sobre la cacería de trofeos en Twitter. Analizamos las categorías concurrentes más comunes que describían la postura de las personas con respecto al tema. Identificamos doce categorías y cuatro arquetipos preliminares en contra de la cacería de trofeos (activista, científico, condenatorio y opositor), cuya oposición derivó de diferentes razonamientos morales. Pocos tuits (22) en nuestra muestra de 500 apoyaban la cacería de trofeos, mientras que 350 se oponían a ella. El debate era hostil, pues 7% de los tuits en nuestra muestra estuvieron categorizados como abusivos. Los debates en línea pueden ser improductivos y nuestros descubrimientos pueden ser importantes para los actores que desean participar de forma efectiva en el debate sobre la cacería de trofeos en Twitter. De manera más generalizada, sostenemos que, debido a la creciente influencia de las redes sociales, es importante que las respuestas públicas a los temas polémicos de conservación estén contextualizadas de manera formal para así auxiliar a la comunicación de la evidencia de conservación y para integrar las diferentes perspectivas públicas en la práctica de la conservación.
Subject(s)
Conservation of Natural Resources , Social Media , Humans , Communication , Conservation of Natural Resources/methods , Hunting , AnimalsABSTRACT
Environmental monitoring is increasingly shifting toward a set of systems that describe changes in real time. In ecology specifically, a series of challenges have prevented the rollout of real-time monitoring for features such as biodiversity change or ecosystem service provision. Conservation culturomics, a field concerned with interactions between people and nature, is well placed to demonstrate how monitoring might move toward a network of real-time platforms, given its existence exclusively in the digital realm. We examined a set of considerations associated with the development of real-time monitoring platforms for conservation culturomics and introduce a near real-time platform for the Species Awareness Index, a global index of changing biodiversity awareness derived from the rate of change in page views for species on Wikipedia. This platform will update automatically each month, operating in near real time (https://joemillard.shinyapps.io/Real_time_SAI/). There are plans to make the underlying data queryable via an application programing interface independent of the platform. The real-time Species Awareness Index will represent the first real-time and entirely automated conservation culturomic platform and one of the first real-time platforms in the discipline of ecology. Real-time monitoring for culturomics can provide insight into human-nature interactions as they play out in the physical realm and provide a framework for the development of real-time monitoring in ecology. Real-time monitoring metrics can be processed on private virtual machines and hosted on publicly available cloud services. Conservation now needs an online, real-time observatory that can evolve with the structure of the web.
Obtención de un sistema virtual de monitoreo en tiempo real para la culturomía de la conservación Resumen El monitoreo ambiental se enfoca cada vez más en un conjunto de sistemas que describen los cambios en tiempo real. En cuanto a la ecología, una serie de obstáculos ha impedido el despliegue del monitoreo en tiempo real para funciones como el cambio en la biodiversidad o el suministro de servicios ambientales. La culturomía de la conservación, un campo enfocado en las interacciones entre las personas y la naturaleza, es una buena opción para demostrar cómo el monitoreo podría transformarse en una red de plataformas en tiempo real, dado que sólo existe en el ámbito digital. Analizamos una serie de consideraciones asociadas con el desarrollo de plataformas de monitoreo en tiempo real para la culturomía de la conservación e introdujimos una plataforma casi en tiempo real para el Índice de Conciencia de Especies, un índice mundial del cambio en la conciencia sobre la biodiversidad derivado de la tasa de cambio en las visitas a las páginas de Wikipedia de diferentes especies. Esta plataforma se actualizará automáticamente cada mes, por lo que opera casi en tiempo real (https://joemillard.shinyapps.io/Real_time_SAI/). Existen planes para hacer que los datos subyacentes sean consultables por medio de una interfaz de programación de aplicaciones independiente de la plataforma. El Índice de Conciencia de Especies en tiempo real será la primera plataforma de culturomía de la conservación automatizada por completo y en tiempo real, así como una de las primeras plataformas de este tipo para la disciplina de la ecología. El monitoreo en tiempo real de la culturomía puede proporcionar información sobre las interacciones humano-naturaleza conforme se desarrollan en el ámbito físico y también un marco de trabajo para el desarrollo del monitoreo en tiempo real para la ecología. Las medidas del monitoreo en tiempo real pueden procesarse en máquinas virtuales privadas y albergarse en servicios públicos de nubes de almacenamiento. Hoy en día, la conservación necesita un observatorio en línea y en tiempo real que pueda evolucionar con la estructura de la web.