An extracellular bacterial pathogen modulates host metabolism to regulate its own sensing and proliferation.

Successful infection depends on the ability of the pathogen to gain nutrients from the host. The extracellular pathogenic bacterium group A Streptococcus (GAS) causes a vast array of human diseases. By using the quorum-sensing sil system as a reporter, we found that, during adherence to host cells, GAS delivers streptolysin toxins, creating endoplasmic reticulum stress. This, in turn, increases asparagine (ASN) synthetase expression and the production of ASN. The released ASN is sensed by the bacteria, altering the expression of ∼17% of GAS genes of which about one-third are dependent on the two-component system TrxSR. The expression of the streptolysin toxins is strongly upregulated, whereas genes linked to proliferation are downregulated in ASN absence. Asparaginase, a widely used chemotherapeutic agent, arrests GAS growth in human blood and blocks GAS proliferation in a mouse model of human bacteremia. These results delineate a pathogenic pathway and propose a therapeutic strategy against GAS infections.

Dromedary camel nanobodies broadly neutralize SARS-CoV-2 variants.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike is a trimer of S1/S2 heterodimers with three receptor-binding domains (RBDs) at the S1 subunit for human angiotensin-converting enzyme 2 (hACE2). Due to their small size, nanobodies can recognize protein cavities that are not accessible to conventional antibodies. To isolate high-affinity nanobodies, large libraries with great diversity are highly desirable. Dromedary camels (Camelus dromedarius) are natural reservoirs of coronaviruses like Middle East respiratory syndrome CoV (MERS-CoV) that are transmitted to humans. Here, we built large dromedary camel VHH phage libraries to isolate nanobodies that broadly neutralize SARS-CoV-2 variants. We isolated two VHH nanobodies, NCI-CoV-7A3 (7A3) and NCI-CoV-8A2 (8A2), which have a high affinity for the RBD via targeting nonoverlapping epitopes and show broad neutralization activity against SARS-CoV-2 and its emerging variants of concern. Cryoelectron microscopy (cryo-EM) complex structures revealed that 8A2 binds the RBD in its up mode with a long CDR3 loop directly involved in the ACE2 binding residues and that 7A3 targets a deeply buried region that uniquely extends from the S1 subunit to the apex of the S2 subunit regardless of the conformational state of the RBD. At a dose of ≥5 mg/kg, 7A3 efficiently protected transgenic mice expressing hACE2 from the lethal challenge of variants B.1.351 or B.1.617.2, suggesting its therapeutic use against COVID-19 variants. The dromedary camel VHH phage libraries could be helpful as a unique platform ready for quickly isolating potent nanobodies against future emerging viruses.

Postoperative thrombotic events following major surgery in patients with a history of COVID-19: a retrospective cohort analysis of commercially insured beneficiaries in the USA.

PURPOSE: We sought to evaluate the synergistic risk of postoperative thrombosis in patients with a history of COVID-19 who undergo major surgery. Major surgery and SARS-CoV-2 infection are independently associated with an increased risk of thrombosis, but the magnitude of additional risk beyond surgery conferred by a COVID-19 history on the development of perioperative thrombotic events has not been clearly elucidated in the literature. METHODS: We conducted a retrospective cohort study among commercially insured adults in the USA from March 2020 to June 2021 using the Optum Labs Data Warehouse (OLDW), a longitudinal, real-world data asset containing deidentified administrative claims and electronic health records. We compared patients with prior COVID-19 who underwent surgery with control individuals who underwent surgery without a COVID-19 history and with control individuals who did not undergo surgery with and without a COVID-19 history. We assessed the interaction of surgery and previous COVID-19 on perioperative thrombotic events (venous thromboembolism and major adverse cardiovascular events) within 90 days using multivariable logistic regression and interaction analysis. RESULTS: Two million and two-hundred thousand eligible patients were identified from the OLDW. Patients in the surgical cohorts were older and more medically complex than nonsurgical population controls. After adjusting for confounders, only surgical exposure-not COVID-19 history-remained associated with perioperative thrombotic events (adjusted odds ratio [aOR], 4.07; 95% confidence interval [CI], 3.81 to 4.36). The multiplicative interaction term (aOR, 1.25; 95% CI, 0.96 to 1.61) and the synergy index (0.76; 95% CI, 0.56 to 1.04) suggest minimal effect modification of prior COVID-19 on surgery with regards to overall thrombotic risk. CONCLUSIONS: We found no evidence of synergistic thrombotic risk from previous COVID-19 in patients who underwent selected major surgery relative to the baseline thrombotic risk from surgery alone.

RéSUMé: OBJECTIF: Nous avons cherché à évaluer le risque synergique de thrombose postopératoire chez les patient·es ayant des antécédents de COVID-19 qui bénéficient d'une intervention chirurgicale majeure. La chirurgie majeure et l'infection par le SRAS-CoV-2 sont indépendamment associées à un risque accru de thrombose, mais l'ampleur du risque supplémentaire d'apparition de complications thrombotiques périopératoires, au-delà de la chirurgie et conféré par des antécédents de COVID-19, n'a pas été clairement élucidée dans la littérature. MéTHODE: Nous avons mené une étude de cohorte rétrospective auprès d'adultes assuré·es commercialement aux États-Unis de mars 2020 à juin 2021 à l'aide de la base de données Optum Labs Data Warehouse (OLDW), un actif de données longitudinales du monde réel contenant des requêtes administratives anonymisées et des dossiers de santé électroniques. Nous avons comparé les patient·es ayant déjà souffert de COVID-19 et ayant bénéficié d'une intervention chirurgicale avec des personnes témoins ayant bénéficié d'une intervention chirurgicale sans antécédents de COVID-19 et avec des personnes témoins n'ayant pas bénéficié de chirurgie, avec et sans antécédents de COVID-19. Nous avons évalué l'interaction de la chirurgie et des antécédents de COVID-19 avec les complications thrombotiques périopératoires (thromboembolie veineuse et événements cardiovasculaires indésirables majeurs) dans les 90 jours à l'aide d'une régression logistique multivariée et d'une analyse des interactions. RéSULTATS: Deux millions deux cent mille personnes admissibles ont été identifiées à partir du registre OLDW. Les patient·es des cohortes chirurgicales étaient plus âgé·es et présentaient une plus grande complexité médicale que les personnes témoins de la population non chirurgicale. Après ajustement pour tenir compte des facteurs de confusion, seule l'exposition chirurgicale ­ et non les antécédents de COVID-19 ­ est restée associée aux complications thrombotiques périopératoires (rapport de cotes ajusté [RCa], 4,07; intervalle de confiance [IC] à 95 %, 3,81 à 4,36). Le terme d'interaction multiplicative (RCa, 1,25; IC 95 %, 0,96 à 1,61) et l'indice de synergie (0,76; IC 95 %, 0,56 à 1,04) suggèrent une modification minimale de l'effet d'un diagnostic antérieur de COVID-19 sur la chirurgie en matière de risque thrombotique global. CONCLUSION: Nous n'avons trouvé aucune preuve de risque thrombotique synergique lié à une COVID-19 antérieure chez les patient·es ayant bénéficié d'une intervention chirurgicale par rapport au risque thrombotique de base lié à la chirurgie seule.

Challenges to decarbonizing medication prescribing and use practices: A call to action.

Climate change undeniably impacts the social and environmental determinants of one's health. The healthcare sector, encompassing medications and the pharmaceutical industry supply chain, accounts for a significant portion of global health care contributions to greenhouse gas (GHG) and waste production. Despite these realities, healthcare professionals - physicians, pharmacists, nurses, and others - may be unaware of GHG emissions and the long-term environmental effects of the medications they prescribe, dispense, and administer daily. In this commentary, we identify existing challenges and explore potential strategies to recognize and reduce the climate change impacts associated with medication use.

Intraoperative Use of Albumin in Major Noncardiac Surgery: Incidence, Variability, and Association With Outcomes.

BACKGROUND: The impact of albumin use during major surgery is unknown, and a dearth of evidence governing its use in major noncardiac surgery has long precluded its standardization in clinical guidelines. OBJECTIVE: In this study, we investigate institutional variation in albumin use among medical centers in the United States during major noncardiac surgery and explore the association of intraoperative albumin administration with important postoperative outcomes. METHODS: The study is an observational retrospective cohort analysis performed among 54 U.S. hospitals in the Multicenter Perioperative Outcomes Group and includes adult patients who underwent major noncardiac surgery under general anesthesia between January 2014 and June 2020. The primary endpoint was the incidence of albumin administration. Secondary endpoints are acute kidney injury (AKI), net-positive fluid balance, pulmonary complications, and 30-day mortality. Albumin-exposed and albumin-unexposed cases were compared within a propensity score-matched cohort to evaluate associations of albumin use with outcomes. RESULTS: Among 614,215 major surgeries, predominantly iso-oncotic albumin was administered in 15.3% of cases and featured significant inter-institutional variability in use patterns. Cases receiving intraoperative albumin involved patients of higher American Society of Anesthesiologists physical status and featured larger infused crystalloid volumes, greater blood loss, and vasopressor use. Overall, albumin was most often administered at high-volume surgery centers with academic affiliation, and within a propensity score-matched cohort (n=153,218), the use of albumin was associated with AKI (aOR 1.24, 95% CI 1.20-1.28, P <0.001), severe AKI (aOR 1.45, 95% CI 1.34-1.56, P <0.001), net-positive fluid balance (aOR 1.18, 95% CI 1.16-1.20, P <0.001), pulmonary complications (aOR 1.56, 95% CI 1.30-1.86, P <0.001), and 30-day all-cause mortality (aOR 1.37, 95% CI 1.26-1.49, P <0.001). CONCLUSIONS: Intravenous albumin is commonly administered among noncardiac surgeries with significant inter-institutional variability in use in the United States. Albumin administration was associated with an increased risk of postoperative complications.

Development of a Radiomics-Based Model to Predict Graft Fibrosis in Liver Transplant Recipients: A Pilot Study.

Liver Transplantation is complicated by recurrent fibrosis in 40% of recipients. We evaluated the ability of clinical and radiomic features to flag patients at risk of developing future graft fibrosis. CT scans of 254 patients at 3-6 months post-liver transplant were retrospectively analyzed. Volumetric radiomic features were extracted from the portal phase using an Artificial Intelligence-based tool (PyRadiomics). The primary endpoint was clinically significant (≥F2) graft fibrosis. A 10-fold cross-validated LASSO model using clinical and radiomic features was developed. In total, 75 patients (29.5%) developed ≥F2 fibrosis by a median of 19 (4.3-121.8) months. The maximum liver attenuation at the venous phase (a radiomic feature reflecting venous perfusion), primary etiology, donor/recipient age, recurrence of disease, brain-dead donor, tacrolimus use at 3 months, and APRI score at 3 months were predictive of ≥F2 fibrosis. The combination of radiomics and the clinical features increased the AUC to 0.811 from 0.793 for the clinical-only model (p = 0.008) and from 0.664 for the radiomics-only model (p < 0.001) to predict future ≥F2 fibrosis. This pilot study exploring the role of radiomics demonstrates that the addition of radiomic features in a clinical model increased the model's performance. Further studies are required to investigate the generalizability of this experimental tool.

Reducing Volatile Anesthetic Waste Using a Commercial Electronic Health Record Clinical Decision Support Tool to Lower Fresh Gas Flows.

BACKGROUND: Volatile anesthetic consumption can be reduced by minimizing excessive fresh gas flows (FGFs). Currently, it is unknown whether decision support tools embedded within commercial electronic health record systems can be successfully adopted to achieve long-term reductions in FGF rates. The authors describe the implementation of an electronic health record-based clinical decision support tool aimed at reducing FGF and evaluate the effectiveness of this intervention in achieving sustained reductions in FGF rates and volatile anesthetic consumption. METHODS: On August 29, 2018, we implemented a decision support tool within the Epic Anesthesia Information Management System (AIMS) to alert providers of high FGF (>0.7 L/min for desflurane and >1 L/min for sevoflurane) during maintenance of anesthesia. July 22, 2015, to July 10, 2018, served as our baseline period before the intervention. The intervention period spanned from August 29, 2018, to December 31, 2019. Our primary outcomes were mean FGF (L/min) and volatile agent consumption (mL/MAC-h). Because a simple comparison of 2 time periods may result in false conclusions due to underlying trends independent of the intervention, we performed segmented regression of the interrupted time series to assess the change in level at the start of the intervention and the differences in slopes before and after the intervention. The analysis was also adjusted for potential confounding variables. Data included 44,899 cases using sevoflurane preintervention with 26,911 cases postintervention, and 17,472 cases using desflurane with 1185 cases postintervention. RESULTS: Segmented regression of the interrupted times series demonstrated a decrease in mean FGF by 0.6 L/min (95% CI, 0.6-0.6 L/min; P < .0001) for sevoflurane and 0.2 L/min (95% CI, 0.2-0.3 L/min; P < .0001) for desflurane immediately after implementation of the intervention. For sevoflurane, mL/MAC-h decreased by 3.8 mL/MAC-h (95% CI, 3.6-4.1 mL/MAC-h; P < .0001) after implementation of the intervention and decreased by 4.1 mL/MAC-h (95% CI, 2.6-5.6 mL/MAC-h; P < .0001) for desflurane. Slopes for both FGF and mL/MAC-h in the postintervention period were statistically less negative than the preintervention slopes (P < .0001 for sevoflurane and P < .01 for desflurane). CONCLUSIONS: A commercial AIMS-based decision support tool can be adopted to change provider FGF management patterns and reduce volatile anesthetic consumption in a sustainable fashion.

Interactive Patient Safety and Quality Improvement capstone during transition-to-residency program: virtual and in-person focused workshop for EPA 13.

Identifying systems failures and contributing to a safety culture is the Association of American Colleges (AAMC's) thirteenth Entrustable Professional Activity (EPA). While most curricula teach Patient Safety (PS) and Quality Improvement (QI) principles, student participation in live QI/PS activities remains limited. This workshop enabled late Clerkship phase students to apply these Health Systems Science (HSS) principles to real adverse patient event cases through team-based simulation.This 3-h capstone included both a didactic review of QI, PS, and TeamSTEPPS® tools and an experiential component where student-led interactive small group discussions were augmented by resident and faculty preceptors. Collaboratively, students composed an adverse patient event report, conducted a Root Cause Analysis (RCA) during role-play, and proposed error prevention ideas after identifying systems problems. In April 2020, the in-person workshop became fully virtual due to the COVID-19 pandemic.A statistically significant increase in ability to identify Serious Safety Events, Escalation Chain of Command, and define a Plan-Do-Study-Act (PDSA) cycle was observed. Comfort with RCA increased from 48 to 87% and comfort with TeamSTEPPS® principles increased from 68% to 85.5%This novel capstone provided students with the tools to synthesize HSS concepts through problem-solving processes and recognize EPA 13's importance. Their increased capability to identify appropriate chain of command, escalate concerns, and recognize serious adverse patient events also has training and practice readiness implications.

Characterization and Outcomes of Hospitalized Children With Coronavirus Disease 2019: A Report From a Multicenter, Viral Infection and Respiratory Illness Universal Study (Coronavirus Disease 2019) Registry.

OBJECTIVES: Multicenter data on the characteristics and outcomes of children hospitalized with coronavirus disease 2019 are limited. Our objective was to describe the characteristics, ICU admissions, and outcomes among children hospitalized with coronavirus disease 2019 using Society of Critical Care Medicine Discovery Viral Infection and Respiratory Illness Universal Study: Coronavirus Disease 2019 registry. DESIGN: Retrospective study. SETTING: Society of Critical Care Medicine Viral Infection and Respiratory Illness Universal Study (Coronavirus Disease 2019) registry. PATIENTS: Children (< 18 yr) hospitalized with coronavirus disease 2019 at participating hospitals from February 2020 to January 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome was ICU admission. Secondary outcomes included hospital and ICU duration of stay and ICU, hospital, and 28-day mortality. A total of 874 children with coronavirus disease 2019 were reported to Viral Infection and Respiratory Illness Universal Study registry from 51 participating centers, majority in the United States. Median age was 8 years (interquartile range, 1.25-14 yr) with a male:female ratio of 1:2. A majority were non-Hispanic (492/874; 62.9%). Median body mass index (n = 817) was 19.4 kg/m2 (16-25.8 kg/m2), with 110 (13.4%) overweight and 300 (36.6%) obese. A majority (67%) presented with fever, and 43.2% had comorbidities. A total of 238 of 838 (28.2%) met the Centers for Disease Control and Prevention criteria for multisystem inflammatory syndrome in children, and 404 of 874 (46.2%) were admitted to the ICU. In multivariate logistic regression, age, fever, multisystem inflammatory syndrome in children, and pre-existing seizure disorder were independently associated with a greater odds of ICU admission. Hospital mortality was 16 of 874 (1.8%). Median (interquartile range) duration of ICU (n = 379) and hospital (n = 857) stay were 3.9 days (2-7.7 d) and 4 days (1.9-7.5 d), respectively. For patients with 28-day data, survival was 679 of 787, 86.3% with 13.4% lost to follow-up, and 0.3% deceased. CONCLUSIONS: In this observational, multicenter registry of children with coronavirus disease 2019, ICU admission was common. Older age, fever, multisystem inflammatory syndrome in children, and seizure disorder were independently associated with ICU admission, and mortality was lower among children than mortality reported in adults.

Graph Convolutional Network-Based Screening Strategy for Rapid Identification of SARS-CoV-2 Cell-Entry Inhibitors.

The cell entry of SARS-CoV-2 has emerged as an attractive drug development target. We previously reported that the entry of SARS-CoV-2 depends on the cell surface heparan sulfate proteoglycan (HSPG) and the cortex actin, which can be targeted by therapeutic agents identified by conventional drug repurposing screens. However, this drug identification strategy requires laborious library screening, which is time consuming, and often limited number of compounds can be screened. As an alternative approach, we developed and trained a graph convolutional network (GCN)-based classification model using information extracted from experimentally identified HSPG and actin inhibitors. This method allowed us to virtually screen 170,000 compounds, resulting in ∼2000 potential hits. A hit confirmation assay with the uptake of a fluorescently labeled HSPG cargo further shortlisted 256 active compounds. Among them, 16 compounds had modest to strong inhibitory activities against the entry of SARS-CoV-2 pseudotyped particles into Vero E6 cells. These results establish a GCN-based virtual screen workflow for rapid identification of new small molecule inhibitors against validated drug targets.

The Triple Bottom Line and Stabilization Wedges: A Framework for Perioperative Sustainability.

We present a narrative review of environmental sustainability aimed at perioperative clinicians. The review will familiarize readers with the triple bottom line framework, which aims to align the goals of delivering high-quality patient care, promoting environmental sustainability, and improving the financial position of health care organizations. We introduce the stabilization wedges model for climate change action adopted for the perioperative setting and discuss areas in which perioperative leaders can make sustainable choices. The goal of this review is to increase awareness among perioperative physicians of the environmental impacts of surgical and anesthetic care, promote engagement with sustainability efforts as a topic of professional concern for our specialty, and inspire new research in perioperative environmental sustainability.

Synergistic and Antagonistic Drug Combinations against SARS-CoV-2.

Antiviral drug development for coronavirus disease 2019 (COVID-19) is occurring at an unprecedented pace, yet there are still limited therapeutic options for treating this disease. We hypothesized that combining drugs with independent mechanisms of action could result in synergy against SARS-CoV-2, thus generating better antiviral efficacy. Using in silico approaches, we prioritized 73 combinations of 32 drugs with potential activity against SARS-CoV-2 and then tested them in vitro. Sixteen synergistic and eight antagonistic combinations were identified; among 16 synergistic cases, combinations of the US Food and Drug Administration (FDA)-approved drug nitazoxanide with remdesivir, amodiaquine, or umifenovir were most notable, all exhibiting significant synergy against SARS-CoV-2 in a cell model. However, the combination of remdesivir and lysosomotropic drugs, such as hydroxychloroquine, demonstrated strong antagonism. Overall, these results highlight the utility of drug repurposing and preclinical testing of drug combinations for discovering potential therapies to treat COVID-19.

Identification of a major determinant for serine-threonine kinase phosphoacceptor specificity.

Eukaryotic protein kinases are generally classified as being either tyrosine or serine-threonine specific. Though not evident from inspection of their primary sequences, many serine-threonine kinases display a significant preference for serine or threonine as the phosphoacceptor residue. Here we show that a residue located in the kinase activation segment, which we term the "DFG+1" residue, acts as a major determinant for serine-threonine phosphorylation site specificity. Mutation of this residue was sufficient to switch the phosphorylation site preference for multiple kinases, including the serine-specific kinase PAK4 and the threonine-specific kinase MST4. Kinetic analysis of peptide substrate phosphorylation and crystal structures of PAK4-peptide complexes suggested that phosphoacceptor residue preference is not mediated by stronger binding of the favored substrate. Rather, favored kinase-phosphoacceptor combinations likely promote a conformation optimal for catalysis. Understanding the rules governing kinase phosphoacceptor preference allows kinases to be classified as serine or threonine specific based on their sequence.

Opioid prescribing practices at hospital discharge for surgical patients before and after the Centers for Disease Control and Prevention's 2016 opioid prescribing guideline.

BACKGROUND: The Centers for Disease Control and Prevention's (CDC) March 2016 opioid prescribing guideline did not include prescribing recommendations for surgical pain. Although opioid over-prescription for surgical patients has been well-documented, the potential effects of the CDC guideline on providers' opioid prescribing practices for surgical patients in the United States remains unclear. METHODS: We conducted an interrupted time series analysis (ITSA) of 37,009 opioid-naïve adult patients undergoing inpatient surgery from 2013-2019 at an academic medical center. We assessed quarterly changes in the discharge opioid prescription days' supply, daily and total doses in oral morphine milligram equivalents (OME), and the proportion of patients requiring opioid refills within 30 days of discharge. RESULTS: The discharge opioid prescription declined by -0.021 (95% CI, -0.045 to 0.003) days per quarter pre-guideline versus -0.201 (95% CI, -0.223 to -0.179) days per quarter post-guideline (p < 0.0001). Likewise, the mean daily and total doses of the discharge opioid prescription declined by -0.387 (95% CI, -0.661 to -0.112) and -7.124 (95% CI, -9.287 to -4.962) OME per quarter pre-guideline versus -2.307 (95% CI, -2.560 to -2.055) and -20.68 (95% CI, -22.66 to -18.69) OME per quarter post-guideline, respectively (p < 0.0001). Opioid refill prescription rates remained unchanged from baseline. CONCLUSIONS: The release of the CDC opioid guideline was associated with a significant reduction in discharge opioid prescriptions without a concomitant increase in the proportion of surgical patients requiring refills within 30 days. The mean prescription for opioid-naïve surgical patients decreased to less than 3 days' supply and less than 50 OME per day by 2019.

Severe liver dysfunction in a toddler receiving nonprescription phytocannabinoid.

BACKGROUND: Nonprescription cannabis products are becoming widely available and being promoted for various health conditions. Safety profile of these products apart from psychoactive effects has not been studied and published well. Liver dysfunction is well described in literature with high doses of recreational tetrahydrocannabinol and cannabidiol products but not with nonprescription phytocannabinoids products used for various medicinal values. CASE SUMMARY: A 2-year-old unimmunized male with infantile spasms and refractory seizures, managed with clobazam and zonisamide, presented for respiratory illness and incidentally diagnosed with severe liver dysfunction with elevated coagulation markers. He did not manifest any clinical signs of liver failure. On further review, it was found that parents were using nonprescription phytocannabinoids (hemp extract) for his neurological condition. He required supportive care for his liver dysfunction, and liver enzymes down trended gradually after holding his phytocannabinoid products. The World Health Organization-Uppsala Monitoring Centre approach puts the presentation as probable/likely category of adverse reaction for liver dysfunction with phytocannabinoid ingestion. PRACTICAL IMPLICATIONS: The case we present shows the detrimental effects of over-the-counter phytocannabinoid products, which could point toward the role of phytocannabinoids in this pathophysiology. The case highlights the importance of awareness of potential life-threatening consequences of these products and educating the patient and the caregivers of these risks. The case also emphasizes the need for serial liver enzymes monitoring for patients receiving these therapies as well as extensive research focusing on safety profile of these products in terms of different organ system affection other than their psychoactive potential.

A role for abdominal ultrasound in discriminating suspected necrotizing enterocolitis in congenital heart disease patients.

PURPOSE: We evaluated the diagnostic utility of abdominal ultrasound (AUS), an adjunct to abdominal X-ray (AXR), for necrotizing enterocolitis (NEC) in congenital heart disease (CHD) patients. METHODS: 86 patients with suspected NEC from 2009 to 2018 were classified as with CHD (n = 18) if they required cardiac intervention versus without CHD (n = 68). Clinical and radiological data were collected, including AXR and AUS concordance. Wilcoxon rank-sum test and Fisher's exact test were performed. RESULTS: CHD patients had higher birth weights (p < 0.001) and gestational ages (p < 0.001) than non-CHD patients. CHD patients presented more frequently with hypotension (p = 0.041) and less frequently with bilious emesis (p < 0.001). Overall, CHD patients were less likely to have AUS findings of pneumatosis (33.3 vs. 72.1%; p = 0.005) and decreased mural flow (0 vs. 20.6%; p = 0.035) compared to non-CHD patients. On concordance analysis, CHD patients had 3.9-fold more discordant studies with pneumatosis on AXR but not on AUS (33.3 vs. 8.8%; p = 0.016) compared to non-CHD patients. Urgent surgery was required in 5.6% of CHD patients versus 16.2% of non-CHD patients. CONCLUSION: CHD patients with suspected NEC represent a distinct clinical population. AUS has particular utility in assessing findings of bowel viability in the CHD NEC population, reflecting reduced rates of surgical NEC.

Risk surveillance and mitigation: autoantibodies as triggers and inhibitors of severe reactions to SARS-CoV-2 infection.

COVID-19 clinical presentation differs considerably between individuals, ranging from asymptomatic, mild/moderate and severe disease which in some cases are fatal or result in long-term effects. Identifying immune mechanisms behind severe disease development informs screening strategies to predict who are at greater risk of developing life-threatening complications. However, to date clear prognostic indicators of individual risk of severe or long COVID remain elusive. Autoantibodies recognize a range of self-antigens and upon antigen recognition and binding, important processes involved in inflammation, pathogen defence and coagulation are modified. Recent studies report a significantly higher prevalence of autoantibodies that target immunomodulatory proteins including cytokines, chemokines, complement components, and cell surface proteins in COVID-19 patients experiencing severe disease compared to those who experience mild or asymptomatic infections. Here we discuss the diverse impacts of autoantibodies on immune processes and associations with severe COVID-19 disease.

Preoperative Medical Testing and Falls in Medicare Beneficiaries Awaiting Cataract Surgery.

PURPOSE: Delaying cataract surgery is associated with an increased risk of falls, but whether routine preoperative testing delays cataract surgery long enough to cause clinical harm is unknown. We sought to determine whether the use of routine preoperative testing leads to harm in the form of delayed surgery and falls in Medicare beneficiaries awaiting cataract surgery. DESIGN: Retrospective, observational cohort study using 2006-2014 Medicare claims. PARTICIPANTS: Medicare beneficiaries 66+ years of age with a Current Procedural Terminology claim for ocular biometry. METHODS: We measured the mean and median number of days between biometry and cataract surgery, calculated the proportion of patients waiting ≥ 30 days or ≥ 90 days for surgery, and determined the odds of sustaining a fall within 90 days of biometry among patients of high-testing physicians (testing performed in ≥ 75% of their patients) compared with patients of low-testing physicians. We also estimated the number of days of delay attributable to high-testing physicians. MAIN OUTCOME MEASURES: Incidence of falls occurring between biometry and surgery, odds of falling within 90 days of biometry, and estimated delay associated with physician testing behavior. RESULTS: Of 248 345 beneficiaries, 16.4% were patients of high-testing physicians. More patients of high-testing physicians waited ≥ 30 days and ≥ 90 days to undergo surgery (31.4% and 8.2% vs. 25.0% and 5.5%, respectively; P < 0.0001 for both). Falls before surgery in patients of high-testing physicians increased by 43% within the 90 days after ocular biometry (1.0% vs. 0.7%; P < 0.0001). The adjusted odds ratio of falling within 90 days of biometry in patients of high-testing physicians versus low-testing physicians was 1.10 (95% confidence interval [CI], 1.03-1.19; P = 0.008). After adjusting for surgical wait time, the odds ratio decreased to 1.07 (95% CI, 1.00-1.15; P = 0.06). The delay associated with having a high-testing physician was approximately 8 days (estimate, 7.97 days; 95% CI, 6.40-9.55 days; P < 0.0001). Other factors associated with delayed surgery included patient race (non-White), Northeast region, ophthalmologist ≤ 40 years of age, and low surgical volume. CONCLUSIONS: Overuse of routine preoperative medical testing by high-testing physicians is associated with delayed surgery and increased falls in cataract patients awaiting surgery.

A Novel Metric for Developing Easy-to-Use and Accurate Clinical Prediction Models: The Time-cost Information Criterion.

BACKGROUND: Guidelines recommend that clinicians use clinical prediction models to estimate future risk to guide decisions. For example, predicted fracture risk is a major factor in the decision to initiate bisphosphonate medications. However, current methods for developing prediction models often lead to models that are accurate but difficult to use in clinical settings. OBJECTIVE: The objective of this study was to develop and test whether a new metric that explicitly balances model accuracy with clinical usability leads to accurate, easier-to-use prediction models. METHODS: We propose a new metric called the Time-cost Information Criterion (TCIC) that will penalize potential predictor variables that take a long time to obtain in clinical settings. To demonstrate how the TCIC can be used to develop models that are easier-to-use in clinical settings, we use data from the 2000 wave of the Health and Retirement Study (n=6311) to develop and compare time to mortality prediction models using a traditional metric (Bayesian Information Criterion or BIC) and the TCIC. RESULTS: We found that the TCIC models utilized predictors that could be obtained more quickly than BIC models while achieving similar discrimination. For example, the TCIC identified a 7-predictor model with a total time-cost of 44 seconds, while the BIC identified a 7-predictor model with a time-cost of 119 seconds. The Harrell C-statistic of the TCIC and BIC 7-predictor models did not differ (0.7065 vs. 0.7088, P=0.11). CONCLUSION: Accounting for the time-costs of potential predictor variables through the use of the TCIC led to the development of an easier-to-use mortality prediction model with similar discrimination.

Application of niclosamide and analogs as small molecule inhibitors of Zika virus and SARS-CoV-2 infection.

Zika virus has emerged as a potential threat to human health globally. A previous drug repurposing screen identified the approved anthelminthic drug niclosamide as a small molecule inhibitor of Zika virus infection. However, as antihelminthic drugs are generally designed to have low absorption when dosed orally, the very limited bioavailability of niclosamide will likely hinder its potential direct repurposing as an antiviral medication. Here, we conducted SAR studies focusing on the anilide and salicylic acid regions of niclosamide to improve physicochemical properties such as microsomal metabolic stability, permeability and solubility. We found that the 5-bromo substitution in the salicylic acid region retains potency while providing better drug-like properties. Other modifications in the anilide region with 2'-OMe and 2'-H substitutions were also advantageous. We found that the 4'-NO2 substituent can be replaced with a 4'-CN or 4'-CF3 substituents. Together, these modifications provide a basis for optimizing the structure of niclosamide to improve systemic exposure for application of niclosamide analogs as drug lead candidates for treating Zika and other viral infections. Indeed, key analogs were also able to rescue cells from the cytopathic effect of SARS-CoV-2 infection, indicating relevance for therapeutic strategies targeting the COVID-19 pandemic.