Hypoxia shapes the immune landscape in lung injury and promotes the persistence of inflammation.

Hypoxemia is a defining feature of acute respiratory distress syndrome (ARDS), an often-fatal complication of pulmonary or systemic inflammation, yet the resulting tissue hypoxia, and its impact on immune responses, is often neglected. In the present study, we have shown that ARDS patients were hypoxemic and monocytopenic within the first 48 h of ventilation. Monocytopenia was also observed in mouse models of hypoxic acute lung injury, in which hypoxemia drove the suppression of type I interferon signaling in the bone marrow. This impaired monopoiesis resulted in reduced accumulation of monocyte-derived macrophages and enhanced neutrophil-mediated inflammation in the lung. Administration of colony-stimulating factor 1 in mice with hypoxic lung injury rescued the monocytopenia, altered the phenotype of circulating monocytes, increased monocyte-derived macrophages in the lung and limited injury. Thus, tissue hypoxia altered the dynamics of the immune response to the detriment of the host and interventions to address the aberrant response offer new therapeutic strategies for ARDS.

Nitration of chemokine CXCL8 acts as a natural mechanism to limit acute inflammation.

Chemokine CXCL8 is a key facilitator of the human host immune response, mediating neutrophil migration, and activation at the site of infection and injury. The oxidative burst is an important effector mechanism which leads to the generation of reactive nitrogen species (RNS), including peroxynitrite. The current study was performed to determine the potential for nitration to alter the biological properties of CXCL8 and its detection in human disease. Here, we show peroxynitrite nitrates CXCL8 and thereby regulates neutrophil migration and activation. The nitrated chemokine was unable to induce transendothelial neutrophil migration in vitro and failed to promote leukocyte recruitment in vivo. This reduced activity is due to impairment in both G protein-coupled receptor signaling and glycosaminoglycan binding. Using a novel antibody, nitrated CXCL8 was detected in bronchoalveolar lavage samples from patients with pneumonia. These findings were validated by mass spectrometry. Our results provide the first direct evidence of chemokine nitration in human pathophysiology and suggest a natural mechanism that limits acute inflammation.

Activation of the hypothalamic-pituitary-adrenal axis by exogenous and endogenous GDF15.

An acute increase in the circulating concentration of glucocorticoid hormones is essential for the survival of severe somatic stresses. Circulating concentrations of GDF15, a hormone that acts in the brain to reduce food intake, are frequently elevated in stressful states. We now report that GDF15 potently activates the hypothalamic-pituitary-adrenal (HPA) axis in mice and rats. A blocking antibody to the GDNF-family receptor α-like receptor completely prevented the corticosterone response to GDF15 administration. In wild-type mice exposed to a range of stressful stimuli, circulating levels of both corticosterone and GDF15 rose acutely. In the case of Escherichia coli or lipopolysaccharide injections, the vigorous proinflammatory cytokine response elicited was sufficient to produce a near-maximal HPA response, regardless of the presence or absence of GDF15. In contrast, the activation of the HPA axis seen in wild-type mice in response to the administration of genotoxic or endoplasmic reticulum toxins, which do not provoke a marked rise in cytokines, was absent in Gdf15-/- mice. In conclusion, consistent with its proposed role as a sentinel hormone, endogenous GDF15 is required for the activation of the protective HPA response to toxins that do not induce a substantial cytokine response. In the context of efforts to develop GDF15 as an antiobesity therapeutic, these findings identify a biomarker of target engagement and a previously unrecognized pharmacodynamic effect, which will require monitoring in human studies.

Exposure to procedural ionizing radiation and cancer risk among physicians.

BACKGROUND: Physicians in certain specialities are routinely exposed to procedural ionizing radiation. Their risk of cancer is unknown, including by cancer sub-types. AIMS: To assess cancer risk among exposed physicians. METHODS: This population-based case-control study was completed in Ontario, Canada, where healthcare is universal, using linkage of physician billing claims to a province-wide cancer registry. Up to five cancer-free physician controls were matched to each cancer-affected physician, by sex, and both age at and year of, entry into practice. Cumulative exposure to procedural ionizing radiation was captured by physician billing claims. Conditional logistic regression generated an odds ratio (OR) of cancer per 1000 procedures performed and as a binary exposure comparing physicians above the upper 95th percentile cumulative number of procedures (≥200) to those below this cut point. RESULTS: Mean (standard deviation) age of the 1265 cases and 5772 non-cancer controls was 39.7 (10.7) and 37.7 (9.0) years, and 45% and 49% were female, respectively. After a median (interquartile ranges) of 13.0 (6.9-20.4) and 12.5 (6.5-20.1) years of lookback among cases and controls, the OR of cancer was 1.02 (95% confidence interval 0.99-1.05; P = NS) per 1000 additional procedures performed. Modelling the cumulative exposure to procedures nonlinearly did not change the observed association (P > 0.40 for each). Comparing physicians above versus below the upper 95th percentile cumulative number of procedures, the OR of cancer was 1.23 (95% confidence interval 0.75-2.01, P = NS). CONCLUSIONS: Physician exposure to procedural ionizing radiation was not associated with a higher risk of cancer. Measures that minimize radiation exposure should continue.

Ultrasound assessment of humeral shaft nonunion risk: a feasibility and proof of concept study.

PURPOSE: To determine the feasibility and reliability of ultrasound in the assessment of humeral shaft fracture healing and estimate the accuracy of 6wk ultrasound in predicting nonunion. METHODS: Twelve adults with a non-operatively managed humeral shaft fracture were prospectively recruited and underwent ultrasound scanning at 6wks and 12wks post-injury. Seven blinded observers evaluated sonographic callus appearance to determine intra- and inter-observer reliability. Nonunion prediction accuracy was estimated by comparing images for patients that united (n = 10/12) with those that developed a nonunion (n = 2/12). RESULTS: The mean scan duration was 8 min (5-12) and all patients tolerated the procedure. At 6wks and 12wks, sonographic callus (SC) was present in 11 patients (10 united, one nonunion) and sonographic bridging callus (SBC) in seven (all united). Ultrasound had substantial intra- (weighted kappa: 6wk 0.75; 12wk 0.75) and inter-observer reliability (intraclass correlation coefficient: 6wk 0.60; 12wk 0.76). At 6wks, the absence of SC demonstrated sensitivity 50%, specificity 100%, positive predictive value (PPV) 100% and negative predictive value (NPV) 91% in nonunion prediction (overall accuracy 92%). The absence of SBC demonstrated sensitivity 100%, specificity 70%, PPV 40% and NPV 100% in nonunion prediction (overall accuracy 75%). Of three patients at risk of nonunion (Radiographic Union Score for HUmeral fractures < 8), one had SBC on 6wk ultrasound (that subsequently united) and the others had non-bridging/absent SC (both developed nonunion). CONCLUSIONS: Ultrasound assessment of humeral shaft fracture healing was feasible, reliable and may predict nonunion. Ultrasound could be useful in defining nonunion risk among patients with reduced radiographic callus formation.

Tracheostomy in children is associated with neutrophilic airway inflammation.

BACKGROUND: Tracheostomies in children are associated with significant morbidity, poor quality of life, excess healthcare costs and excess mortality. The underlying mechanisms facilitating adverse respiratory outcomes in tracheostomised children are poorly understood. We aimed to characterise airway host defence in tracheostomised children using serial molecular analyses. METHODS: Tracheal aspirates, tracheal cytology brushings and nasal swabs were prospectively collected from children with a tracheostomy and controls. Transcriptomic, proteomic and metabolomic methods were applied to characterise the impact of tracheostomy on host immune response and the airway microbiome. RESULTS: Children followed up serially from the time of tracheostomy up to 3 months postprocedure (n=9) were studied. A further cohort of children with a long-term tracheostomy were also enrolled (n=24). Controls (n=13) comprised children without a tracheostomy undergoing bronchoscopy. Long-term tracheostomy was associated with airway neutrophilic inflammation, superoxide production and evidence of proteolysis when compared with controls. Reduced airway microbial diversity was established pre-tracheostomy and sustained thereafter. CONCLUSIONS: Long-term childhood tracheostomy is associated with a inflammatory tracheal phenotype characterised by neutrophilic inflammation and the ongoing presence of potential respiratory pathogens. These findings suggest neutrophil recruitment and activation as potential exploratory targets in seeking to prevent recurrent airway complications in this vulnerable group of patients.

Pooled prevalence of lymphopenia in all-cause hospitalisations and association with infection: a systematic review and meta-analysis.

BACKGROUND: Lymphopenia is defined as a decrease below normal value (often 1.0 x 109 cells/L) of blood circulating lymphocyte count. In the general population, lymphopenia is associated with an increased risk of hospitalisation secondary to infection, independent of traditional clinical risk factors. In hospital, lymphopenia is associated with increased risk of healthcare-associated infection and mortality. By summarising lymphopenia's prevalence and impact on clinical outcomes, we can identify an at-risk population and inform future studies of immune dysfunction following severe illness. METHODS: Peer-reviewed search strategy was performed on three databases. Primary objective was to summarise the pooled prevalence of lymphopenia. Primary outcome was infection including pre-existing lymphopenia as a risk factor for admission with infection and as an in-hospital risk factor for healthcare-associated infection. Secondary outcomes were length of stay and mortality. Mortality data extracted included in-hospital, 28/30-day ('early'), and 90-day/1-year ('late') mortality. Meta-analysis was carried out using random-effects models for each outcome measure. Heterogeneity was assessed using I2 statistic. Joanna Briggs Institute checklist for cohort studies was used to assess risk of bias. The protocol was published on PROSPERO. RESULTS: Fifteen observational studies were included. The pooled prevalence of lymphopenia in all-cause hospitalisations was 38% (CI 0.34-0.42, I2= 97%, p< 0.01). Lymphopenia was not associated with an infection diagnosis at hospital admission and healthcare associated infection (RR 1.03; 95% CI 0.26-3.99, p=0.97, I2 = 55% and RR 1.31; 95% CI 0.78-2.20, p=0.31, I2=97%, respectively), but was associated with septic shock (RR 2.72; 95% CI 1.02-7.21, p=0.04, I2 =98%). Lymphopenia was associated with higher in-hospital mortality and higher 'early' mortality rates (RR 2.44; 95% CI 1.71-3.47, p < 0.00001, I2 = 89% and RR 2.05; 95% CI 1.64-2.56, p < 0.00001, I2 = 29%, respectively). Lymphopenia was associated with higher 'late' mortality (RR 1.59; 1.33-1.90, p < 0.00001, I2 = 0%). CONCLUSIONS: This meta-analysis demonstrates the high prevalence of lymphopenia across all-cause hospitalisations and associated increased risk of septic shock, early and late mortality. Lymphopenia is a readily available marker that may identify immune dysfunctional patients. Greater understanding of immune trajectories following survival may provide insights into longer-term poor clinical outcomes.

Phosphoinositide 3-Kinase δ Inhibition Improves Neutrophil Bacterial Killing in Critically Ill Patients at High Risk of Infection.

Acquired neutrophil dysfunction frequently develops during critical illness, independently increasing the risk for intensive care unit-acquired infection. PI3Kδ is implicated in driving neutrophil dysfunction and can potentially be targeted pharmacologically. The aims of this study were to determine whether PI3Kδ inhibition reverses dysfunction in neutrophils from critically ill patients and to describe potential mechanisms. Neutrophils were isolated from blood taken from critically ill patients requiring intubation and mechanical ventilation, renal support, or blood pressure support. In separate validation experiments, neutrophil dysfunction was induced pharmacologically in neutrophils from healthy volunteers. Phagocytosis and bacterial killing assays were performed, and activity of RhoA and protein kinase A (PKA) was assessed. Inhibitors of PI3Kδ, 3-phosphoinositide-dependent protein kinase-1 (PDK1), and PKA were used to determine mechanisms of neutrophil dysfunction. Sixty-six patients were recruited. In the 27 patients (40.9%) with impaired neutrophil function, PI3Kδ inhibition consistently improved function and significantly increased bacterial killing. These findings were validated in neutrophils from healthy volunteers with salbutamol-induced dysfunction and extended to demonstrate that PI3Kδ inhibition restored killing of clinical isolates of nine pathogens commonly associated with intensive care unit-acquired infection. PI3Kδ activation was associated with PDK1 activation, which in turn phosphorylated PKA, which drove phosphorylation and inhibition of the key regulator of neutrophil phagocytosis, RhoA. These data indicate that, in a significant proportion of critically ill patients, PI3Kδ inhibition can improve neutrophil function through PDK1- and PKA-dependent processes, suggesting that therapeutic use of PI3Kδ inhibitors warrants investigation in this setting.

Environmental metabolomics uncovers oxidative stress, amino acid dysregulation, and energy impairment in Daphnia magna with exposure to industrial effluents.

Anthropogenic activities are regarded as point sources of pollution entering freshwater bodies worldwide. With over 350,000 chemicals used in manufacturing, wastewater treatment and industrial effluents are comprised of complex mixtures of organic and inorganic pollutants of known and unknown origins. Consequently, their combined toxicity and mode of action are not well understood in aquatic organisms such as Daphnia magna. In this study, effluent samples from wastewater treatment and industrial sectors were used to examine molecular-level perturbations to the polar metabolic profile of D. magna. To determine if the industrial sector and/or the effluent chemistries played a role in the observed biochemical responses, Daphnia were acutely (48 h) exposed to undiluted (100%) and diluted (10, 25, and 50%) effluent samples. Endogenous metabolites were extracted from single daphnids and analyzed using targeted mass spectrometry-based metabolomics. The metabolic profile of Daphnia exposed to effluent samples resulted in significant separation compared to the unexposed controls. Linear regression analysis determined that no single pollutant detected in the effluents was significantly correlated with the responses of metabolites. Significant perturbations were uncovered across many classes of metabolites (amino acids, nucleosides, nucleotides, polyamines, and their derivatives) which serve as intermediates in keystone biochemical processes. The combined metabolic responses are consistent with oxidative stress, disruptions to energy metabolism, and protein dysregulation which were identified through biochemical pathway analysis. These results provide insight into the molecular processes driving stress responses in D. magna. Overall, we determined that the metabolic profile of Daphnia could not be predicted by the chemical composition of environmentally relevant mixtures. The findings of this study demonstrate the advantage of metabolomics in conjunction with chemical analyses to assess the interactions of industrial effluents. This work further demonstrates the ability of environmental metabolomics to characterize molecular-level perturbations in aquatic organisms exposed to complex chemical mixtures directly.

Regional variations and deprivation are linked to poorer access to laparoscopic and robotic colorectal surgery: a national study in England.

BACKGROUND: Laparoscopic and now robotic colorectal surgery has rapidly increased in prevalence; however, little is known about how uptake varies by region and sociodemographics. The aim of this study was to quantify the uptake of minimally invasive colorectal surgery (MIS) over time and variations by region, sociodemographics and ethnicity. METHODS: Retrospective analysis of routinely collected healthcare data (Clinical Practice Research Datalink linked to Hospital Episode Statistics) for all adults having elective colorectal resectional surgery in England from 1 January 2006 to 31 March 2020. Sociodemographics between modalities were compared and the association between sociodemographic factors, region and year on MIS was compared in multivariate logistic regression analysis. RESULTS: A total of 93,735 patients were included: 52,098 open, 40,622 laparoscopic and 1015 robotic cases. Laparoscopic surgery surpassed open in 2015 but has plateaued; robotic surgery has rapidly increased since 2017, representing 3.2% of cases in 2019. Absolute differences up to 20% in MIS exist between regions, OR 1.77 (95% CI 1.68-1.86) in South Central and OR 0.75 (95% CI 0.72-0.79) in the North West compared to the largest region (West Midlands). MIS was less common in the most compared to least deprived (14.6% of MIS in the most deprived, 24.8% in the least, OR 0.85 95% CI 0.81-0.89), with a greater difference in robotic surgery (13.4% vs 30.5% respectively). Female gender, younger age, less comorbidity, Asian or 'Other/Mixed' ethnicity and cancer indication were all associated with increased MIS. CONCLUSIONS: MIS has increased over time, with significant regional and socioeconomic variations. With rapid increases in robotic surgery, national strategies for procurement, implementation, equitable distribution and training must be created to avoid worsening health inequalities.

Fractures in elderly mice demonstrate delayed ossification of the soft callus: a cellular and radiographic study.

OBJECTIVES: The aim of this study was to assess the cellular age-related changes in fracture repair and relate these to the observed radiographic assessments at differing time points. METHODS: Transverse traumatic tibial diaphyseal fractures were created in 12-14 weeks old (young n = 16) and 18 months old (elderly n = 20) in Balb/C wild mice. Fracture calluses were harvested at five time points from 1 to 35 days post fracture for histomorphometry (percent of cartilage and bone), radiographic analysis (total callus volume, callus index, and relative bone mineral content). RESULTS: The elderly mice produced an equal amount of cartilage when compared to young mice (p > 0.08). However, by day 21 there was a significantly greater percentage of bone at the fracture site in the young group (mean percentage 50% versus 11%, p < 0.001). It was not until day 35 when the elderly group produced a similar amount of bone compared to the young group at 21 days (50% versus 53%, non-significant (ns)). The callus area and callus index on radiographic assessment was not significantly different between young and elderly groups at any time point. Relative bone mineral content was significantly greater in the young group at 14 days (545.7 versus -120.2, p < 0.001) and 21 days (888.7 versus 451.0, p < 0.001) when compared to the elderly group. It was not until day 35 when the elderly group produced a similar relative bone mineral content as the young group at 21 days (888.7 versus 921.8, ns). CONCLUSIONS: Elderly mice demonstrated a delay in endochondral ossification which was associated with a decreased relative bone mineral content at the fracture site and may help assess these cellular changes in a clinical setting.

Modelling trajectories of parentally reported and physician-confirmed atopic dermatitis in a birth cohort study.

BACKGROUND: In a population-based birth cohort, we aimed to identify longitudinal trajectories of atopic dermatitis (AD) during childhood using data from different sources (validated questionnaires and healthcare records). We investigated the impact of different AD definitions on such trajectories and their relationships with various risk factors. METHODS: Of the 1184 children born into the study, 1083 had information on current AD for at least three follow-ups from birth to age 11 years and were included in the analysis for parentally reported AD (PRAD). Data were transcribed from healthcare records for 916 of 1184 children for the analysis of doctor-diagnosed AD (DDAD). We also derived a composite definition of AD (CDAD) (at least two of the following: PRAD, DDAD, current use of AD treatment). Using latent class analysis (LCA), we determined longitudinal profiles of AD using the three definitions. Filaggrin (FLG) genotype data were available for 803 white participants. RESULTS: For PRAD, LCA identified four AD classes ('no AD', 'persistent', 'early-onset remitting' and 'late-onset'). For DDAD and CDAD, the optimal number of phenotypes was three ('no AD', 'persistent' and 'early-onset remitting'). Although AD classes at population level appeared similar in different models, a considerable proportion of children (n = 485, 45%) moved between classes. The association with FLG genotype, atopic diseases and early-life risk factors was inconsistent across different definitions, but the association with oral food challenge-confirmed peanut allergy was similar, with a nine- to 11-fold increase among children in the persistent AD class. In a CDAD model, compared with the early-onset remitting class, those with persistent AD were significantly more likely to have (at age 3 years) moderate/severe AD, polysensitization and current wheeze, and were less likely to have been breastfed. CONCLUSIONS: Standardized composite definitions of AD may help to define AD cases with more precision and identify more consistent long-term trajectories.

Oropharyngeal swallowing physiology and safety in patients with Idiopathic Pulmonary Fibrosis: a consecutive descriptive case series.

INTRODUCTION: Dysphagia occurs in multiple respiratory pathophysiologies, increasing the risk of pulmonary complications secondary to aspiration. Reflux associated aspiration and a dysregulated lung microbiome is implicated in Idiopathic Pulmonary Fibrosis (IPF), but swallowing dysfunction has not been described. We aimed to explore oropharyngeal swallowing in IPF patients, without known swallowing dysfunction. METHODS: Fourteen consecutive outpatients with a secure diagnosis of IPF were recruited and the 10-item Eating Assessment Tool (Eat 10) used to assess patient perception of swallowing difficulty. Oropharyngeal swallowing was assessed in ten patients using Videofluoroscopy Swallow Studies (VFSS). The studies were rated using validated scales: Penetration-Aspiration Scale (PAS); standardised Modified Barium Swallow Impairment Profile (MBSImP). RESULTS: EAT-10 scores indicated frank swallowing difficulty in 4/14 patients. Videofluoroscopy Studies showed that 3/10 patients had airway penetration, and one aspirated liquid without a cough response. Median MBSImp for oral impairment was 5, range [3-7] and pharyngeal impairment 4, range [1-14] indicating, overall mild alteration to swallowing physiology. CONCLUSION: We conclude that people with IPF can show a range of swallowing dysfunction, including aspiration into an unprotected airway. To our knowledge, this is the first report on swallowing physiology and safety in IPF. We believe a proportion of this group may be at risk of aspiration. Further work is indicated to fully explore swallowing in this vulnerable group.

Target inhibition of galectin-3 by inhaled TD139 in patients with idiopathic pulmonary fibrosis.

Galectin (Gal)-3 is a profibrotic ß-galactoside-binding lectin that plays a key role in the pathogenesis of idiopathic pulmonary fibrosis (IPF) and IPF exacerbations. TD139 is a novel and potent small-molecule inhibitor of Gal-3.A randomised, double-blind, multicentre, placebo-controlled, phase 1/2a study was conducted to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of inhaled TD139 in 36 healthy subjects and 24 patients with IPF. Six dose cohorts of six healthy subjects were evaluated (4:2 TD139:placebo ratio) with single doses of TD139 (0.15-50 mg) and three dose cohorts of eight patients with IPF (5:3 TD139:placebo ratio) with once-daily doses of TD139 (0.3-10 mg) for 14 days.Inhaled TD139 was well tolerated with no significant treatment-related side-effects. TD139 was rapidly absorbed, with mean time taken to reach maximum plasma concentration (C max) values ranging from 0.6 to 3 h and a plasma half-life (T 1/2) of 8 h. The concentration of TD139 in the lung was >567-fold higher than in the blood, with systemic exposure predicting exposure in the target compartment. Gal-3 expression on alveolar macrophages was reduced in the 3 and 10 mg dose groups compared with placebo, with a concentration-dependent inhibition demonstrated. Inhibition of Gal-3 expression in the lung was associated with reductions in plasma biomarkers centrally relevant to IPF pathobiology (platelet-derived growth factor-BB, plasminogen activator inhibitor-1, Gal-3, CCL18 and YKL-40).TD139 is safe and well tolerated in healthy subjects and IPF patients. It was shown to suppress Gal-3 expression on bronchoalveolar lavage macrophages and, in a concerted fashion, decrease plasma biomarkers associated with IPF progression.

Core Outcome Measures for Trials in People With Coronavirus Disease 2019: Respiratory Failure, Multiorgan Failure, Shortness of Breath, and Recovery.

OBJECTIVES: Respiratory failure, multiple organ failure, shortness of breath, recovery, and mortality have been identified as critically important core outcomes by more than 9300 patients, health professionals, and the public from 111 countries in the global coronavirus disease 2019 core outcome set initiative. The aim of this project was to establish the core outcome measures for these domains for trials in coronavirus disease 2019. DESIGN: Three online consensus workshops were convened to establish outcome measures for the four core domains of respiratory failure, multiple organ failure, shortness of breath, and recovery. SETTING: International. PATIENTS: About 130 participants (patients, public, and health professionals) from 17 countries attended the three workshops. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Respiratory failure, assessed by the need for respiratory support based on the World Health Organization Clinical Progression Scale, was considered pragmatic, objective, and with broad applicability to various clinical scenarios. The Sequential Organ Failure Assessment was recommended for multiple organ failure, because it was routinely used in trials and clinical care, well validated, and feasible. The Modified Medical Research Council measure for shortness of breath, with minor adaptations (recall period of 24 hr to capture daily fluctuations and inclusion of activities to ensure relevance and to capture the extreme severity of shortness of breath in people with coronavirus disease 2019), was regarded as fit for purpose for this indication. The recovery measure was developed de novo and defined as the absence of symptoms, resumption of usual daily activities, and return to the previous state of health prior to the illness, using a 5-point Likert scale, and was endorsed. CONCLUSIONS: The coronavirus disease 2019 core outcome set recommended core outcome measures have content validity and are considered the most feasible and acceptable among existing measures. Implementation of the core outcome measures in trials in coronavirus disease 2019 will ensure consistency and relevance of the evidence to inform decision-making and care of patients with coronavirus disease 2019.

Reproducibility of 19 F-MR ventilation imaging in healthy volunteers.

PURPOSE: To assess the reproducibility of percentage ventilated lung volume (%VV) measurements in healthy volunteers acquired by fluorine (19 F)-MRI of inhaled perfluoropropane, implemented at two research sites. METHODS: In this prospective, ethically approved study, 40 healthy participants were recruited (May 2018-June 2019) to one of two research sites. Participants underwent a single MRI scan session on a 3T scanner, involving periodic inhalation of a 79% perfluoropropane/21% oxygen gas mixture. Each gas inhalation session lasted about 30 seconds, consisting of three deep breaths of gas followed by a breath-hold. Four 19 F-MR ventilation images were acquired per participant, each separated by approximately 6 minutes. The value of %VV was determined by registering separately acquired 1 H images to ventilation images before semi-automated image segmentation, performed independently by two observers. Reproducibility of %VV measurements was assessed by components of variance, intraclass correlation coefficients, coefficients of variation (CoV), and the Dice similarity coefficient. RESULTS: The MRI scans were well tolerated throughout, with no adverse events. There was a high degree of consistency in %VV measurements for each participant (CoVobserver1 = 0.43%; CoVobserver2 = 0.63%), with overall precision of %VV measurements determined to be within ± 1.7% (95% confidence interval). Interobserver agreement in %VV measurements revealed a high mean Dice similarity coefficient (SD) of 0.97 (0.02), with only minor discrepancies between observers. CONCLUSION: We demonstrate good reproducibility of %VV measurements in a group of healthy participants using 19 F-MRI of inhaled perfluoropropane. Our methods have been successfully implemented across two different study sites, supporting the feasibility of performing larger multicenter clinical studies.

Multigene phylogenetics of euglenids based on single-cell transcriptomics of diverse phagotrophs.

Euglenids are a well-known group of single-celled eukaryotes, with phototrophic, osmotrophic and phagotrophic members. Phagotrophs represent most of the phylogenetic diversity of euglenids, and gave rise to the phototrophs and osmotrophs, but their evolutionary relationships are poorly understood. Symbiontids, in contrast, are anaerobes that are alternatively inferred to be derived euglenids, or a separate euglenozoan group. Most phylogenetic studies of euglenids have examined the SSU rDNA only, which is often highly divergent. Also, many phagotrophic euglenids (and symbiontids) are uncultured, restricting collection of other molecular data. We generated transcriptome data for 28 taxa, mostly using a single-cell approach, and conducted the first multigene phylogenetic analyses of euglenids to include phagotrophs and symbiontids. Euglenids are recovered as monophyletic, with symbiontids forming an independent branch within Euglenozoa. Spirocuta, the clade of flexible euglenids that contains both the phototrophs (Euglenophyceae) and osmotrophs (Aphagea), is robustly resolved, with the ploeotid Olkasia as its sister group, forming the new taxon Olkaspira. Ploeotids are paraphyletic, although Ploeotiidae (represented by Ploeotia spp.), Lentomonas, and Keelungia form a robust clade (new taxon Alistosa). Petalomonadida branches robustly as sister to other euglenids in outgroup-rooted analyses. Within Spirocuta, Euglenophyceae is a robust clade that includes Rapaza, and Anisonemia is a well-supported monophyletic group containing Anisonemidae (Anisonema and Dinema spp.), 'Heteronema II' (represented by H. vittatum), and a clade of Neometanema plus Aphagea. Among 'peranemid' phagotrophs, Chasmostoma branches with included Urceolus, and Peranema with the undescribed 'Jenningsia II', while other relationships are weakly supported and consequently the closest sister group to Euglenophyceae remains unresolved. Our results are inconsistent with recent inferences that Entosiphon is the evolutionarily pivotal sister either to other euglenids, or to Spirocuta. At least three transitions between posterior and anterior flagellar gliding occurred in euglenids, with the phylogenetic positions and directions of those transitions remaining ambiguous.

The levonorgestrel intrauterine system for prevention of endometrial cancer in women with obesity: A cost-effectiveness study.

OBJECTIVE: To estimate the cost-effectiveness of the levonorgestrel intrauterine system (LNG-IUS) as an endometrial cancer prevention strategy in women with obesity. METHODS: A Markov decision-analytic model was used to compare 5 strategies in women with a body mass index of 30 or greater: 1) Usual care 2) LNG-IUS for 5 years 3) LNG-IUS for 7 years 4) LNG-IUS for 5 years, replaced once for a total of 10 years 5) LNG-IUS for 7 years, replaced once for a total of 14 years. Obesity was presumed to be associated with a 3-fold relative risk of endometrial cancer incidence and a 2.65-fold disease-specific mortality. The LNG-IUS was assumed to confer a 50% reduction in cancer incidence over the period of the LNG-IUS insertion. Outcomes were incremental cost-effectiveness ratios, calculated in 2019 Canadian dollars (CAD) per year of life saved. One-way and two-way sensitivity analyses were performed. RESULTS: The LNG-IUS strategy was considered cost-effective if the cost of the intervention is less than $66,400 CAD ($50,000 US dollars) per year of life saved. The strategy becomes cost-effective if the LNG-IUS is inserted at age 57 (strategy #2), at age 52 for strategy #3, at age 51 for strategy #4 and at age 45 for strategy #5, when compared to usual care. The results are stable to variations in cost but sensitive to the estimated risk reduction of the LNG-IUS and the impact of obesity on endometrial cancer incidence and disease-specific mortality. CONCLUSION: The LNG-IUS is a cost-effective method of endometrial cancer prevention in women with obesity.

Pulmonary Aspergillosis in Patients with Suspected Ventilator-associated Pneumonia in UK ICUs.

Rationale:Aspergillus infection in patients with suspected ventilator-associated pneumonia remains uncharacterized because of the absence of a disease definition and limited access to sensitive diagnostic tests.Objectives: To estimate the prevalence and outcomes of Aspergillus infection in adults with suspected ventilator-associated pneumonia.Methods: Two prospective UK studies recruited 360 critically ill adults with new or worsening alveolar shadowing on chest X-ray and clinical/hematological parameters supporting suspected ventilator-associated pneumonia. Stored serum and BAL fluid were available from 194 nonneutropenic patients and underwent mycological testing. Patients were categorized as having probable Aspergillus infection using a definition comprising clinical, radiological, and mycological criteria. Mycological criteria included positive histology or microscopy, positive BAL fluid culture, galactomannan optical index of 1 or more in BAL fluid or 0.5 or more in serum.Measurements and Main Results: Of 194 patients evaluated, 24 met the definition of probable Aspergillus infection, giving an estimated prevalence of 12.4% (95% confidence interval, 8.1-17.8). All 24 patients had positive galactomannan in serum (n = 4), BAL fluid (n = 16), or both (n = 4); three patients cultured Aspergillus sp. in BAL fluid. Patients with probable Aspergillus infection had a significantly longer median duration of critical care stay (25.5 vs. 15.5 d, P = 0.02). ICU mortality was numerically higher in this group, although this was not statistically significant (33.3% vs. 22.8%; P = 0.23).Conclusions: The estimated prevalence for probable Aspergillus infection in this geographically dispersed multicenter UK cohort indicates that this condition should be considered when investigating patients with suspected ventilator-associated pneumonia, including patient groups not previously recognized to be at high risk of aspergillosis.