Efficacy and Safety of Liraglutide in Patients With an Ileal Pouch-Anal Anastomosis and Chronic High Bowel Frequency: A Placebo-Controlled, Crossover, Proof-of-Concept Study.

INTRODUCTION: After colectomy with ileoanal pouch anastomosis (IPAA), many patients develop high bowel frequency (BF) refractory to antimotility agents, despite normal IPAA morphology. Low circulating levels of glucagon-like protein-1 (GLP-1), a modulator of gastroduodenal motility, have been reported after colectomy. METHODS: Double-blind crossover study of 8 IPAA patients with refractory high BF treated with daily administration of the GLP-1 receptor agonist liraglutide or placebo. RESULTS: Liraglutide, but not placebo, reduced daily BF by more than 35% ( P < 0.03). DISCUSSION: Larger randomized controlled studies are warranted to delineate the treatment potential of GLP-1 receptor agonists in IPAA patients suffering from noninflammatory high BF.

Bone cement repair of malleus handle fractures: Intraoperative video and case report of two patients.

Isolated malleus fractures are a rare occurrence with few reported cases in the literature. Symptoms include sudden otalgia, hearing loss, tinnitus and aural fullness. Work-up and diagnosis are based on a combination of thorough anamnesis and careful otoscopic evaluation or high-resolution computer tomography. We present two cases of isolated malleus handle fractures who were diagnosed based on a combination of pneumatic otoscopy and tympanometry. Both fractures were surgically repaired using hydroxyapatite bone cement as showcased in the supplemental video material. Post-operative audiometry showed improvement in the pure-tone-average of both patients as well as normalisation of tympanometry. Isolated malleus fracture should be suspected in cases of sudden hearing loss and tinnitus following digital manipulation of the outer ear canal together with a conductive hearing loss with a mostly high-frequent air-bone-gap and hypercompliant tympanometry with hypermobility of the tympanic membrane on pneumatic insufflation. Surgical repair of the fracture using bone cement has good hearing outcomes and leads to improvement in auditory symptoms.

Impact of COVID-19 restrictions on self-poisoning behaviour with mild analgesics in Danish youth.

BACKGROUND: The COVID-19 pandemic prompted the implementation of precautions to contain the disease, including lockdowns and social isolation. Previous studies have investigated suicide rates among children and adolescents during the pandemic and have found varying results. We speculated how the two lockdowns influenced suicidal behaviour in children and adolescents in Denmark. OBJECTIVE: This study aimed to investigate the effect of lockdowns during the COVID-19 pandemic on suicide attempts, as measured by the incidence rate in all self-poisonings with mild analgesics among children and adolescents. METHODS: This national Danish registry-based study on children and adolescents used Poisson regression and interrupted time series analysis to examine the incidence rates and trends of self-poisonings with mild analgesics from 2019 to mid-2021. RESULTS: For the period of this study, 1655 self-poisonings were registered. During the first lockdown, there was a slight, not statistically significant, decrease in self-poisoning rates (incidence rate ratio [IRR]) 0.98) compared to no lockdown. During the second lockdown, there was a significant increase in self-poisonings for the whole Danish population (IRR 1.85) with girls being slightly higher at risk (IRR 1.87). Being a girl or between the ages of 13-17 years old were risk factors for self-poisoning. CONCLUSION: These findings indicate that the restrictions enforced during the second lockdown greatly impacted youth mental health, especially girls, leading to an 85% increase in self-poisonings. We hope for increased awareness of mental health in children and adolescents during possible future lockdowns.

On the Mechanism of the Formal [2+2] Cycloaddition - Retro-electrocyclization (CA-RE) Reaction.

The [2+2] cycloaddition - retro-electrocyclization (CA-RE) reaction is a "click-like" protocol for facile synthesis of donor-acceptor chromophores from an alkyne and tetracyanoethylene. Herein we shed light on the mechanism of this reaction by detailed kinetics studies using 1 H NMR spectroscopy. By considering several experiments simultaneously, a variety of mechanistic models was evaluated. Surprisingly, a model in which the final 1,1,4,4-tetracyanobuta-1,3-diene product promoted the first step was the only one that described well the experimental data. This autocatalysis model also involved a non-concerted, stepwise formation of the cyclobutene cycloaddition adduct. By proper choice of conditions, we were able to generate the transient cyclobutene in sufficient amount to verify it as an intermediate using 13 C NMR spectroscopy. For its final retro-electrocyclization step, simple first-order kinetics was observed and only minor solvent dependence, which indicates a concerted reaction.

Low-Cost COTS GNSS Interference Monitoring, Detection, and Classification System.

Interference signals cause position errors and outages to global navigation satellite system (GNSS) receivers. However, to solve these problems, the interference source must be detected, classified, its purpose determined, and localized to eliminate it. Several interference monitoring solutions exist, but these are expensive, resulting in fewer nodes that may miss spatially sparse interference signals. This article introduces a low-cost commercial-off-the-shelf (COTS) GNSS interference monitoring, detection, and classification receiver. It employs machine learning (ML) on tailored signal pre-processing of the raw signal samples and GNSS measurements to facilitate a generalized, high-performance architecture that does not require human-in-the-loop (HIL) calibration. Therefore, the low-cost receivers with high performance can justify significantly more receivers being deployed, resulting in a significantly higher probability of intercept (POI). The architecture of the monitoring system is described in detail in this article, including an analysis of the energy consumption and optimization. Controlled interference scenarios demonstrate detection and classification capabilities exceeding conventional approaches. The ML results show that accurate and reliable detection and classification are possible with COTS hardware.

Computational Evolution Of New Catalysts For The Morita-Baylis-Hillman Reaction.

We present a de novo discovery of an efficient catalyst of the Morita-Baylis-Hillman (MBH) reaction by searching chemical space for molecules that lower the estimated barrier of the rate-determining step using a genetic algorithm (GA) starting from randomly selected tertiary amines. We identify 435 candidates, virtually all of which contain an azetidine N as the catalytically active site, which is discovered by the GA. Two molecules are selected for further study based on their predicted synthetic accessibility and have predicted rate-determining barriers that are lower than that of a known catalyst. Azetidines have not been used as catalysts for the MBH reaction. One suggested azetidine is successfully synthesized and showed an eightfold increase in activity over a commonly used catalyst. We believe this is the first experimentally verified de novo discovery of an efficient catalyst using a generative model.

Use of an Amplatzer ASD Occlusion Device for the Closure of an Ascending Aortic Pseudoaneurysm Presenting as Hemoptysis.

Aortic pseudoaneurysms can commonly be caused by previous thoracic surgery, trauma, and infection, quickly becoming life-threatening if ruptured. This pathology is typically asymptomatic and incidentally found on imaging; however, few cases have outlined hemoptysis as a presenting symptom for aortic pseudoaneurysms. Traditionally, management of these patients included surgical correction; however, percutaneous approaches have emerged as a safe alternative, helping to reduce the risk of morbidity and mortality associated with surgical correction. This report seeks to describe a case in which hemoptysis was the symptom unveiling the finding of a thoracic ascending aortic pseudoaneurysm and the use of an Amplatzer atrial septal defect (ASD) occlusion device as a viable option to safely resolve the disease process.

Comparison of oscillometric, non-invasive and invasive arterial pressure monitoring in patients undergoing laparoscopic bariatric surgery - a secondary analysis of a prospective observational study.

BACKGROUND: Oscillometric, non-invasive blood pressure measurement (NIBP) is the first choice of blood pressure monitoring in the majority of low and moderate risk surgeries. In patients with morbid obesity, however, it is subject to several limitations. The aim was to compare arterial pressure monitoring by NIBP and a non-invasive finger-cuff technology (Nexfin®) with the gold-standard invasive arterial pressure (IAP). METHODS: In this secondary analysis of a prospective observational, single centre cohort study, systolic (SAP), diastolic (DAP) and mean arterial pressure (MAP) were measured at 16 defined perioperative time points including posture changes, fluid bolus administration and pneumoperitoneum (PP) in patients undergoing laparoscopic bariatric surgery. Absolute arterial pressures by NIBP, Nexfin® and IAP were compared using correlation and Bland Altman analyses. Interchangeability was defined by a mean difference ≤ 5 mmHg (SD ≤8 mmHg). Percentage error (PE) was calculated as an additional statistical estimate. For hemodynamic trending, concordance rates were analysed according to the Critchley criterion. RESULTS: Sixty patients (mean body mass index of 49.2 kg/m2) were enrolled and data from 56 finally analysed. Pooled blood pressure values of all time points showed a significant positive correlation for both NIPB and Nexfin® versus IAP. Pooled PE for NIBP versus IAP was 37% (SAP), 35% (DAP) and 30% (MAP), for Nexfin versus IAP 23% (SAP), 26% (DAP) and 22% (MAP). Correlation of MAP was best and PE lowest before induction of anesthesia for NIBP versus IAP (r = 0.72; PE 24%) and after intraoperative fluid bolus administration for Nexfin® versus IAP (r = 0.88; PE: 17.2%). Concordance of MAP trending was 90% (SAP 85%, DAP 89%) for NIBP and 91% (SAP 90%, DAP 86%) for Nexfin®. MAP trending was best during intraoperative ATP positioning for NIBP (97%) and at induction of anesthesia for Nexfin® (97%). CONCLUSION: As compared with IAP, interchangeability of absolute pressure values could neither be shown for NIBP nor Nexfin®, however, NIBP showed poorer overall correlation and precision. Overall trending ability was generally high with Nexfin® surpassing NIBP. Nexfin® may likely render individualized decision-making in the management of different hemodynamic stresses during laparoscopic bariatric surgery, particularly where NIBP cannot be reliably established. TRIAL REGISTRATION: The non-interventional, observational study was registered retrospectively at ( NCT03184285 ) on June 12, 2017.

Multi-Photochromic Molecules Based on Dihydroazulene Units.

Multi-photochromic systems incorporating individually addressable switching units are attractive for development of advanced data storage devices. Here, we present the synthesis and properties of a selection of such molecular systems incorporating the dihydroazulene/vinylheptafulvene (DHA/VHF) photo-/thermoswitch. The influence of the linker (meta-phenylene vs. azulene-1,3-diyl vs. thiophene-2,5-diyl) separating two DHA units on the switching properties was investigated. An azulene-1,3-diyl spacer largely inhibited both the DHA-to-VHF photoisomerizations and the thermal VHF-to-DHA back-reactions; the latter occurred ten times slower than for the related compound with a meta-phenylene spacer. A DHA trimer containing three DHA units around a central benzene ring was found to undergo stepwise DHA-to-VHF photoisomerizations, whereas the thermal back-reactions occurred at similar rates for the three VHF entities. A meta-phenylene-bridged DHA dimer was subjected to further structural modifications at position C-1 of each DHA, having strong implications for the switching events, and synthetic steps for further functionalizations at position C-7 of each DHA were investigated. Finally, the molecular structure (from X-ray crystallographic analysis) between the meta-phenylene-bridged DHA dimer and CuI is presented.

Perioperative non-invasive versus semi-invasive cardiac index monitoring in patients with bariatric surgery - a prospective observational study.

BACKGROUND: In morbidly obese patients undergoing laparoscopic bariatric surgery, the combination of obesity-related comorbidities, pneumoperitoneum and extreme posture changes constitutes a high risk of perioperative hemodynamic complications. Thus, an advanced hemodynamic monitoring including continuous cardiac index (CI) assessment is desirable. While invasive catheterization may bear technical difficulties, transesophageal echocardiography is contraindicated due to the surgical procedure. Evidence on the clinical reliability of alternative semi- or non-invasive cardiac monitoring devices is limited. The aim was to compare the non-invasive vascular unloading to a semi-invasive pulse contour analysis reference technique for continuous CI measurements in bariatric surgical patients. METHODS: This prospective observational study included adult patients scheduled for elective, laparoscopic bariatric surgery after obtained institutional ethics approval and written informed consent. CI measurements were performed using the vascular unloading technique (Nexfin®) and semi-invasive reference method (FloTrac™). At 10 defined measurement time points, the influence of clinically indicated body posture changes, passive leg raising, fluid bolus administration and pneumoperitoneum was evaluated pre- and intraoperatively. Correlation, Bland-Altman and concordance analyses were performed. RESULTS: Sixty patients (mean BMI 49.2 kg/m2) were enrolled into the study and data from 54 patients could be entered in the final analysis. Baseline CI was 3.2 ± 0.9 and 3.3 ± 0.8 l/min/m2, respectively. Pooled absolute CI values showed a positive correlation (rs = 0.76, P < 0.001) and mean bias of of - 0.16 l/min/m2 (limits of agreement: - 1.48 to 1.15 l/min/m2) between the two methods. Pooled percentage error was 56.51%, missing the criteria of interchangeability (< 30%). Preoperatively, bias ranged from - 0.33 to 0.08 l/min/m2 with wide limits of agreement. Correlation of CI was best (rs = 0.82, P < 0.001) and percentage error lowest (46.34%) during anesthesia and after fluid bolus administration. Intraoperatively, bias ranged from - 0.34 to - 0.03 l/min/m2 with wide limits of agreement. CI measurements correlated best during pneumoperitoneum and after fluid bolus administration (rs = 0.77, P < 0.001; percentage error 35.95%). Trending ability for all 10 measurement points showed a concordance rate of 85.12%, not reaching the predefined Critchley criterion (> 92%). CONCLUSION: Non-invasive as compared to semi-invasive CI measurements did not reach criteria of interchangeability for monitoring absolute and trending values of CI in morbidly obese patients undergoing bariatric surgery. TRIAL REGISTRATION: The study was registered retrospectively on June 12, 2017 with the registration number NCT03184272 .

Enterococcus faecalis Gluconate Phosphotransferase System Accelerates Experimental Colitis and Bacterial Killing by Macrophages.

Enterococcus faecalis strains are resident intestinal bacteria associated with invasive infections, inflammatory bowel diseases, and colon cancer. Although factors promoting E. faecalis colonization of intestines are not fully known, one implicated pathway is a phosphotransferase system (PTS) in E. faecalis strain OG1RF that phosphorylates gluconate and contains the genes OG1RF_12399 to OG1RF_12402 (OG1RF_12399-12402). We hypothesize that this PTS permits growth in gluconate, facilitates E. faecalis intestinal colonization, and exacerbates colitis. We generated E. faecalis strains containing deletions/point mutations in this PTS and measured bacterial growth and PTS gene expression in minimal medium supplemented with selected carbohydrates. We show that E. faecalis upregulates OG1RF_12399 transcription specifically in the presence of gluconate and that E. faecalis strains lacking, or harboring a single point mutation in, OG1RF_12399-12402 are unable to grow in minimal medium containing gluconate. We colonized germfree wild-type and colitis-prone interleukin-10-deficient mice with defined bacterial consortia containing the E. faecalis strains and measured inflammation and bacterial abundance in the colon. We infected macrophage and intestinal epithelial cell lines with the E. faecalis strains and measured intracellular bacterial survival and proinflammatory cytokine secretion. The presence of OG1RF_12399-12402 is not required for E. faecalis colonization of the mouse intestine but is associated with an accelerated onset of experimental colitis in interleukin-10-deficient mice, altered bacterial composition in the colon, enhanced E. faecalis survival within macrophages, and increased proinflammatory cytokine secretion by colon tissue and macrophages. Further studies of bacterial carbohydrate metabolism in general, and E. faecalis PTS-gluconate in particular, during inflammation may identify new mechanisms of disease pathogenesis.

Surface-Associated Lipoproteins Link Enterococcus faecalis Virulence to Colitogenic Activity in IL-10-Deficient Mice Independent of Their Expression Levels.

The commensal Enterococcus faecalis is among the most common causes of nosocomial infections. Recent findings regarding increased abundance of enterococci in the intestinal microbiota of patients with inflammatory bowel diseases and induction of colitis in IL-10-deficient (IL-10-/-) mice put a new perspective on the contribution of E. faecalis to chronic intestinal inflammation. Based on the expression of virulence-related genes in the inflammatory milieu of IL-10-/- mice using RNA-sequencing analysis, we characterized the colitogenic role of two bacterial structures that substantially impact on E. faecalis virulence by different mechanisms: the enterococcal polysaccharide antigen and cell surface-associated lipoproteins. Germ-free wild type and IL-10-/- mice were monoassociated with E. faecalis wild type OG1RF or the respective isogenic mutants for 16 weeks. Intestinal tissue and mesenteric lymph nodes (MLN) were collected to characterize tissue pathology, loss of intestinal barrier function, bacterial adhesion to intestinal epithelium and immune cell activation. Bone marrow-derived dendritic cells (BMDC) were stimulated with bacterial lysates and E. faecalis virulence was additionally investigated in three invertebrate models. Colitogenic activity of wild type E. faecalis (OG1RF score: 7.2±1.2) in monoassociated IL-10-/- mice was partially impaired in E. faecalis lacking enterococcal polysaccharide antigen (ΔepaB score: 4.7±2.3; p<0.05) and was almost completely abrogated in E. faecalis deficient for lipoproteins (Δlgt score: 2.3±2.3; p<0.0001). Consistently both E. faecalis mutants showed significantly impaired virulence in Galleria mellonella and Caenorhabditis elegans. Loss of E-cadherin in the epithelium was shown for all bacterial strains in inflamed IL-10-/- but not wild type mice. Inactivation of epaB in E. faecalis reduced microcolony and biofilm formation in vitro, altered bacterial adhesion to intestinal epithelium of germ-free Manduca sexta larvae and impaired penetration into the colonic mucus layer of IL-10-/- mice. Lipoprotein-deficient E. faecalis exhibited an impaired TLR2-mediated activation of BMDCs in vitro despite their ability to fully reactivate MLN cells as well as MLN-derived colitogenic T cells ex vivo. E. faecalis virulence factors accounting for bacterial adhesion to mucosal surfaces as well as intestinal barrier disruption partially contribute to colitogenic activity of E. faecalis. Beyond their well-known role in infections, cell surface-associated lipoproteins are essential structures for colitogenic activity of E. faecalis by mediating innate immune cell activation.

Projected shifts in fish species dominance in Wisconsin lakes under climate change.

Temperate lakes may contain both coolwater fish species such as walleye (Sander vitreus) and warmwater fish species such as largemouth bass (Micropterus salmoides). Recent declining walleye and increasing largemouth bass populations have raised questions regarding the future trajectories and management actions for these species. We developed a thermodynamic model of water temperatures driven by downscaled climate data and lake-specific characteristics to estimate daily water temperature profiles for 2148 lakes in Wisconsin, US, under contemporary (1989-2014) and future (2040-2064 and 2065-2089) conditions. We correlated contemporary walleye recruitment and largemouth bass relative abundance to modeled water temperature, lake morphometry, and lake productivity, and projected lake-specific changes in each species under future climate conditions. Walleye recruitment success was negatively related and largemouth bass abundance was positively related to water temperature degree days. Both species exhibited a threshold response at the same degree day value, albeit in opposite directions. Degree days were predicted to increase in the future, although the magnitude of increase varied among lakes, time periods, and global circulation models (GCMs). Under future conditions, we predicted a loss of walleye recruitment in 33-75% of lakes where recruitment is currently supported and a 27-60% increase in the number of lakes suitable for high largemouth bass abundance. The percentage of lakes capable of supporting abundant largemouth bass but failed walleye recruitment was predicted to increase from 58% in contemporary conditions to 86% by mid-century and to 91% of lakes by late century, based on median projections across GCMs. Conversely, the percentage of lakes with successful walleye recruitment and low largemouth bass abundance was predicted to decline from 9% of lakes in contemporary conditions to only 1% of lakes in both future periods. Importantly, we identify up to 85 resilient lakes predicted to continue to support natural walleye recruitment. Management resources could target preserving these resilient walleye populations.

Transplantation of prokaryotic two-component signaling pathways into mammalian cells.

Signaling pathway engineering is a promising route toward synthetic biological circuits. Histidine-aspartate phosphorelays are thought to have evolved in prokaryotes where they form the basis for two-component signaling. Tyrosine-serine-threonine phosphorelays, exemplified by MAP kinase cascades, are predominant in eukaryotes. Recently, a prokaryotic two-component pathway was implemented in a plant species to sense environmental trinitrotoluene. We reasoned that "transplantation" of two-component pathways into mammalian host could provide an orthogonal and diverse toolkit for a variety of signal processing tasks. Here we report that two-component pathways could be partially reconstituted in mammalian cell culture and used for programmable control of gene expression. To enable this reconstitution, coding sequences of histidine kinase (HK) and response regulator (RR) components were codon-optimized for human cells, whereas the RRs were fused with a transactivation domain. Responsive promoters were furnished by fusing DNA binding sites in front of a minimal promoter. We found that coexpression of HKs and their cognate RRs in cultured mammalian cells is necessary and sufficient to strongly induce gene expression even in the absence of pathways' chemical triggers in the medium. Both loss-of-function and constitutive mutants behaved as expected. We further used the two-component signaling pathways to implement two-input logical AND, NOR, and OR gene regulation. Thus, two-component systems can be applied in different capacities in mammalian cells and their components can be used for large-scale synthetic gene circuits.

Immune Responses to Intestinal Microbes in Inflammatory Bowel Diseases.

Inflammatory bowel diseases (IBDs), including Crohn's disease and ulcerative colitis, are characterized by chronic, T-cell-mediated inflammation of the gastrointestinal tract that can cause significant, lifelong morbidity. Data from both human and animal studies indicate that IBDs are likely caused by dysregulated immune responses to resident intestinal microbes. Certain products from mycobacteria, fungi, and Clostridia stimulate increased effector T cell responses during intestinal inflammation, whereas other bacterial products from Clostridia and Bacteroides promote anti-inflammatory regulatory T cell responses. Antibody responses to bacterial and fungal components may help predict the severity of IBDs. While most currently approved treatments for IBDs generally suppress the patient's immune system, our growing understanding of microbial influences in IBDs will likely lead to the development of new diagnostic tools and therapies that target the intestinal microbiota.

Escherichia coli heme oxygenase modulates host innate immune responses.

Induction of mammalian heme oxygenase (HO)-1 and exposure of animals to carbon monoxide (CO) ameliorates experimental colitis. When enteric bacteria, including Escherichia coli, are exposed to low iron conditions, they express an HO-like enzyme, chuS, and metabolize heme into iron, biliverdin and CO. Given the abundance of enteric bacteria residing in the intestinal lumen, our postulate was that commensal intestinal bacteria may be a significant source of CO and those that express chuS and other Ho-like molecules suppress inflammatory immune responses through release of CO. According to real-time PCR, exposure of mice to CO results in changes in enteric bacterial composition and increases E. coli 16S and chuS DNA. Moreover, the severity of experimental colitis correlates positively with E. coli chuS expression in IL-10 deficient mice. To explore functional roles, E. coli were genetically modified to overexpress chuS or the chuS gene was deleted. Co-culture of chuS-overexpressing E. coli with bone marrow-derived macrophages resulted in less IL-12p40 and greater IL-10 secretion than in wild-type or chuS-deficient E. coli. Mice infected with chuS-overexpressing E. coli have more hepatic CO and less serum IL-12 p40 than mice infected with chuS-deficient E. coli. Thus, CO alters the composition of the commensal intestinal microbiota and expands populations of E. coli that harbor the chuS gene. These bacteria are capable of attenuating innate immune responses through expression of chuS. Bacterial HO-like molecules and bacteria-derived CO may represent novel targets for therapeutic intervention in inflammatory conditions.

Carbon monoxide and heme oxygenase-1 prevent intestinal inflammation in mice by promoting bacterial clearance.

BACKGROUND & AIMS: Heme oxygenase-1 (HO-1) and its metabolic by-product, carbon monoxide (CO), protect against intestinal inflammation in experimental models of colitis, but little is known about their intestinal immune mechanisms. We investigated the interactions among CO, HO-1, and the enteric microbiota in mice and zebrafish. METHODS: Germ-free, wild-type, and interleukin (Il)10(-/-) mice and germ-free zebrafish embryos were colonized with specific pathogen-free (SPF) microbiota. Germ-free or SPF-raised wild-type and Il10(-/-) mice were given intraperitoneal injections of cobalt(III) protoporphyrin IX chloride (CoPP), which up-regulates HO-1, the CO-releasing molecule Alfama-186, or saline (control). Colitis was induced in wild-type mice housed in SPF conditions by infection with Salmonella typhimurium. RESULTS: In colons of germ-free, wild-type mice, SPF microbiota induced production of HO-1 via activation of nuclear factor erythroid 2-related factor 2-, IL-10-, and Toll-like receptor-dependent pathways; similar observations were made in zebrafish. SPF microbiota did not induce HO-1 in colons of germ-free Il10(-/-) mice. Administration of CoPP to Il10(-/-) mice before transition from germ-free to SPF conditions reduced their development of colitis. In Il10(-/-) mice, CO and CoPP reduced levels of enteric bacterial genomic DNA in mesenteric lymph nodes. In mice with S typhimurium-induced enterocolitis, CoPP reduced the numbers of live S typhimurium recovered from the lamina propria, mesenteric lymph nodes, spleen, and liver. Knockdown of HO-1 in mouse macrophages impaired their bactericidal activity against E coli, E faecalis, and S typhimurium, whereas exposure to CO or overexpression of HO-1 increased their bactericidal activity. HO-1 induction and CO increased acidification of phagolysosomes. CONCLUSIONS: Colonic HO-1 prevents colonic inflammation in mice. HO-1 is induced by the enteric microbiota and its homeostatic function is mediated, in part, by promoting bactericidal activities of macrophages.

Emergency department variation in utilization and diagnostic yield of advanced radiography in diagnosis of pulmonary embolus.

BACKGROUND: There is growing pressure to measure and reduce unnecessary imaging in the emergency department. OBJECTIVE: We study provider and hospital variation in utilization and diagnostic yield for advanced radiography in diagnosis of pulmonary embolism (PE) and to assess patient- and provider-level factors associated with diagnostic yield. METHODS: Retrospective chart review of all adult patients presenting to four hospitals from January 2006 through December 2009 who had a computed tomography or ventilation/perfusion scan to evaluate for PE. Demographic data on the providers ordering the scans were collected. Diagnostic yield (positive scans/total scans ordered) was calculated at the hospital and provider level. The study was not designed to assess appropriateness of imaging. RESULTS: There was significant variation in utilization and diagnostic yield at the hospital level (chi-squared, p < 0.05). Diagnostic yield ranged from 4.2% to 8.2%; after adjusting for patient- and provider-level factors; the two hospitals with an emergency medicine residency training program had higher diagnostic yields (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.6-2.5 and OR 1.9, 95% CI 1.5-2.4). There was no significant variation in diagnostic yield among the 90 providers after adjusting for patient, hospital, and provider characteristics. Providers with < 10 years of experience had lower odds of diagnosing a PE than more experienced graduates (OR 0.8, 95% CI 0.6-0.9). CONCLUSIONS: Although we found significant variation in utilization of advanced radiography for PE and diagnostic yield at the hospital level, there was no significant variation at the provider level after adjusting for patient-, hospital-, and provider-level factors.

A standardized protocol using clinical adjudication to define true infection status in patients presenting to the emergency department with suspected infections and/or sepsis.

In absence of a "gold standard", a standardized clinical adjudication process was developed for a registrational trial of a transcriptomic host response (HR) test. Two physicians independently reviewed clinical data to adjudicate presence and source of bacterial and viral infections in emergency department patients. Discordant cases were resolved by a third physician. Agreement among 955 cases was 74.1% (708/955) for bacterial, 75.6% (722/955) for viral infections, and 71.2% (680/955) overall. Most discordances were minor (85.2%; 409/480) versus moderate (11.7%; 56/480) or complete (3.3%; 16/480). Concordance levels were lowest for bacterial skin and soft tissue infections (8.2%) and for viral respiratory tract infections (4.5%). This robust adjudication process can be used to evaluate HR tests and other diagnostics by regulatory agencies and for educating clinicians, laboratorians, and clinical researchers. Clinicaltrials.gov NCT04094818. SUMMARY: Without a gold standard for evaluating host response tests, clinical adjudication is a robust reference standard that is essential to determine the true infection status in diagnostic registrational clinical studies.

Inflammation-induced acid tolerance genes gadAB in luminal commensal Escherichia coli attenuate experimental colitis.

Dysregulated immune responses to commensal intestinal bacteria, including Escherichia coli, contribute to the development of inflammatory bowel diseases (IBDs) and experimental colitis. Reciprocally, E. coli responds to chronic intestinal inflammation by upregulating expression of stress response genes, including gadA and gadB. GadAB encode glutamate decarboxylase and protect E. coli from the toxic effects of low pH and fermentation acids, factors present in the intestinal lumen in patients with active IBDs. We hypothesized that E. coli upregulates gadAB during inflammation to enhance its survival and virulence. Using real-time PCR, we determined gadAB expression in luminal E. coli from ex-germfree wild-type (WT) and interleukin-10 (IL-10) knockout (KO) (IL-10(-/-)) mice selectively colonized with a commensal E. coli isolate (NC101) that causes colitis in KO mice in isolation or in combination with 7 other commensal intestinal bacterial strains. E. coli survival and host inflammatory responses were measured in WT and KO mice colonized with NC101 or a mutant lacking the gadAB genes (NC101ΔgadAB). The susceptibility of NC101 and NC101ΔgadAB to killing by host antimicrobial peptides and their translocation across intestinal epithelial cells were evaluated using bacterial killing assays and transwell experiments, respectively. We show that expression of gadAB in luminal E. coli increases proportionately with intestinal inflammation in KO mice and enhances the susceptibility of NC101 to killing by the host antimicrobial peptide cryptdin-4 but decreases bacterial transmigration across intestinal epithelial cells, colonic inflammation, and mucosal immune responses. Chronic intestinal inflammation upregulates acid tolerance pathways in commensal E. coli isolates, which, contrary to our original hypothesis, limits their survival and colitogenic potential. Further investigation of microbial adaptation to immune-mediated inflammation may provide novel insights into the pathogenesis and treatment of IBDs.