A host-directed oxadiazole compound potentiates antituberculosis treatment via zinc poisoning in human macrophages and in a mouse model of infection.

Antituberculosis drugs, mostly developed over 60 years ago, combined with a poorly effective vaccine, have failed to eradicate tuberculosis. More worryingly, multiresistant strains of Mycobacterium tuberculosis (MTB) are constantly emerging. Innovative strategies are thus urgently needed to improve tuberculosis treatment. Recently, host-directed therapy has emerged as a promising strategy to be used in adjunct with existing or future antibiotics, by improving innate immunity or limiting immunopathology. Here, using high-content imaging, we identified novel 1,2,4-oxadiazole-based compounds, which allow human macrophages to control MTB replication. Genome-wide gene expression analysis revealed that these molecules induced zinc remobilization inside cells, resulting in bacterial zinc intoxication. More importantly, we also demonstrated that, upon treatment with these novel compounds, MTB became even more sensitive to antituberculosis drugs, in vitro and in vivo, in a mouse model of tuberculosis. Manipulation of heavy metal homeostasis holds thus great promise to be exploited to develop host-directed therapeutic interventions.

An octameric PqiC toroid stabilises the outer-membrane interaction of the PqiABC transport system.

The E. coli Paraquat Inducible (Pqi) Pathway is a putative Gram-negative phospholipid transport system. The pathway comprises three components: an integral inner membrane protein (PqiA), a periplasmic spanning MCE family protein (PqiB) and an outer membrane lipoprotein (PqiC). Interactions between all complex components, including stoichiometry, remain uncharacterised; nevertheless, once assembled into their quaternary complex, the trio of Pqi proteins are anticipated to provide a continuous channel between the inner and outer membranes of diderms. Here, we present X-ray structures of both the native and a truncated, soluble construct of the PqiC lipoprotein, providing insight into its biological assembly, and utilise neutron reflectometry to characterise the nature of the PqiB-PqiC-membrane interaction. Finally, we employ phenotypic complementation assays to probe specific PqiC residues, which imply the interaction between PqiB and PqiC is less intimate than previously anticipated.

A measles-vectored vaccine candidate expressing prefusion-stabilized SARS-CoV-2 spike protein brought to phase I/II clinical trials: candidate selection in a preclinical murine model.

In the early COVID-19 pandemic with urgent need for countermeasures, we aimed at developing a replicating viral vaccine using the highly efficacious measles vaccine as vector, a promising technology with prior clinical proof of concept. Building on our successful pre-clinical development of a measles virus (MV)-based vaccine candidate against the related SARS-CoV, we evaluated several recombinant MV expressing codon-optimized SARS-CoV-2 spike glycoprotein. Candidate V591 expressing a prefusion-stabilized spike through introduction of two proline residues in HR1 hinge loop, together with deleted S1/S2 furin cleavage site and additional inactivation of the endoplasmic reticulum retrieval signal, was the most potent in eliciting neutralizing antibodies in mice. After single immunization, V591 induced similar neutralization titers as observed in sera of convalescent patients. The cellular immune response was confirmed to be Th1 skewed. V591 conferred long-lasting protection against SARS-CoV-2 challenge in a murine model with marked decrease in viral RNA load, absence of detectable infectious virus loads, and reduced lesions in the lungs. V591 was furthermore efficacious in an established non-human primate model of disease (see companion article [S. Nambulli, N. Escriou, L. J. Rennick, M. J. Demers, N. L. Tilston-Lunel et al., J Virol 98:e01762-23, 2024, https://doi.org/10.1128/jvi.01762-23]). Thus, V591 was taken forward into phase I/II clinical trials in August 2020. Unexpected low immunogenicity in humans (O. Launay, C. Artaud, M. Lachâtre, M. Ait-Ahmed, J. Klein et al., eBioMedicine 75:103810, 2022, https://doi.org/10.1016/j.ebiom.2021.103810) revealed that the underlying mechanisms for resistance or sensitivity to pre-existing anti-measles immunity are not yet understood. Different hypotheses are discussed here, which will be important to investigate for further development of the measles-vectored vaccine platform.IMPORTANCESARS-CoV-2 emerged at the end of 2019 and rapidly spread worldwide causing the COVID-19 pandemic that urgently called for vaccines. We developed a vaccine candidate using the highly efficacious measles vaccine as vector, a technology which has proved highly promising in clinical trials for other pathogens. We report here and in the companion article by Nambulli et al. (J Virol 98:e01762-23, 2024, https://doi.org/10.1128/jvi.01762-23) the design, selection, and preclinical efficacy of the V591 vaccine candidate that was moved into clinical development in August 2020, 7 months after the identification of SARS-CoV-2 in Wuhan. These unique in-human trials of a measles vector-based COVID-19 vaccine revealed insufficient immunogenicity, which may be the consequence of previous exposure to the pediatric measles vaccine. The three studies together in mice, primates, and humans provide a unique insight into the measles-vectored vaccine platform, raising potential limitations of surrogate preclinical models and calling for further refinement of the platform.

Retention of uninfected red blood cells causing congestive splenomegaly is the major mechanism of anemia in malaria.

Splenomegaly frequently occurs in patients with Plasmodium falciparum (Pf) or P. vivax (Pv) malarial anemia, but mechanisms underlying this co-occurrence are unclear. In malaria-endemic Papua, Indonesia, we prospectively analyzed red blood cell (RBC) concentrations in the spleen and spleen-mimetic retention in 37 subjects splenectomized for trauma or hyperreactive splenomegaly, most of whom were infected with Plasmodium. Splenomegaly (median 357 g [range: 80-1918 g]) was correlated positively with the proportion of red-pulp on histological sections (median 88.1% [range: 74%-99.4%]; r = .59, p = .0003) and correlated negatively with the proportion of white-pulp (median 8.3% [range: 0.4%-22.9%]; r = -.50, p = .002). The number of RBC per microscopic field (>95% uninfected) was correlated positively with spleen weight in both Pf-infected (r = .73; p = .017) and Pv-infected spleens (r = .94; p = .006). The median estimated proportion of total-body RBCs retained in Pf-infected spleens was 8.2% (range: 1.0%-33.6%), significantly higher than in Pv-infected (2.6% [range: 0.6%-23.8%]; p = .015) and PCR-negative subjects (2.5% [range: 1.0%-3.3%]; p = .006). Retained RBCs accounted for over half of circulating RBC loss seen in Pf infections. The proportion of total-body RBC retained in Pf- and Pv-infected spleens correlated negatively with hemoglobin concentrations (r = -.56, p = .0003), hematocrit (r = -.58, p = .0002), and circulating RBC counts (r = -.56, p = .0003). Splenic CD71-positive reticulocyte concentrations correlated with spleen weight in Pf (r = 1.0; p = .003). Retention rates of peripheral and splenic RBCs were correlated negatively with circulating RBC counts (r = -.69, p = .07 and r = -.83, p = .008, respectively). In conclusion, retention of mostly uninfected RBC in the spleen, leading to marked congestion of the red-pulp, was associated with splenomegaly and is the major mechanism of anemia in subjects infected with Plasmodium, particularly Pf.

An intranasal lentiviral booster reinforces the waning mRNA vaccine-induced SARS-CoV-2 immunity that it targets to lung mucosa.

As the coronavirus disease 2019 (COVID-19) pandemic continues and new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern emerge, the adaptive immunity initially induced by the first-generation COVID-19 vaccines starts waning and needs to be strengthened and broadened in specificity. Vaccination by the nasal route induces mucosal, humoral, and cellular immunity at the entry point of SARS-CoV-2 into the host organism and has been shown to be the most effective for reducing viral transmission. The lentiviral vaccination vector (LV) is particularly suitable for this route of immunization owing to its non-cytopathic, non-replicative, and scarcely inflammatory properties. Here, to set up an optimized cross-protective intranasal booster against COVID-19, we generated an LV encoding stabilized spike of SARS-CoV-2 Beta variant (LV::SBeta-2P). mRNA vaccine-primed and -boosted mice, with waning primary humoral immunity at 4 months after vaccination, were boosted intranasally with LV::SBeta-2P. A strong boost effect was detected on cross-sero-neutralizing activity and systemic T cell immunity. In addition, mucosal anti-spike IgG and IgA, lung-resident B cells, and effector memory and resident T cells were efficiently induced, correlating with complete pulmonary protection against the SARS-CoV-2 Delta variant, demonstrating the suitability of the LV::SBeta-2P vaccine candidate as an intranasal booster against COVID-19. LV::SBeta-2P vaccination was also fully protective against Omicron infection of the lungs and central nervous system, in the highly susceptible B6.K18-hACE2IP-THV transgenic mice.

#COVIDisAirborne: AI-enabled multiscale computational microscopy of delta SARS-CoV-2 in a respiratory aerosol.

We seek to completely revise current models of airborne transmission of respiratory viruses by providing never-before-seen atomic-level views of the SARS-CoV-2 virus within a respiratory aerosol. Our work dramatically extends the capabilities of multiscale computational microscopy to address the significant gaps that exist in current experimental methods, which are limited in their ability to interrogate aerosols at the atomic/molecular level and thus obscure our understanding of airborne transmission. We demonstrate how our integrated data-driven platform provides a new way of exploring the composition, structure, and dynamics of aerosols and aerosolized viruses, while driving simulation method development along several important axes. We present a series of initial scientific discoveries for the SARS-CoV-2 Delta variant, noting that the full scientific impact of this work has yet to be realized.

Contemporary management and natural history of aberrant right subclavian artery.

OBJECTIVE: An aberrant right subclavian artery (ARSA) is the most common congenital anomaly of the aortic arch. A paucity of reported studies is available regarding the treatment of these patients. The purpose of the present study was to evaluate the contemporary management strategies and natural history of ARSA in these patients. METHODS: A single-center retrospective review of patients with a diagnosis of ARSA from 2009 to 2019 was performed. Computed tomography scans were analyzed, and the aortic and ARSA diameters were measured at 10 different segments. The demographic data, comorbidities, and operative interventions were collected. The patients were categorized into those who had undergone intervention and those who had undergone expectant management. Linear mixed effect models were used to estimate the annual ARSA diameter changes. RESULTS: A total of 30 patients with ARSA were identified, 17 (57%) of whom were women. The average age for the cohort was 54.5 ± 14.6 years. Of the 30 patients, 20 (67%) had undergone operative repair at presentation and 10 (33%) were initially observed. The most common presenting symptom was dysphagia (30%). Of the 10 patients who had been initially treated expectantly, 4 had subsequently required intervention. Of the 24 operative interventions, 13 (54%) were hybrid procedures involving right carotid-subclavian bypass or transposition and thoracic endovascular aortic repair. The mean diameter of ARSA at its origin was 20.4 ± 5.7 mm, and the mean cross-sectional aortic diameter at the level of the ARSA was 31.8 ± 8.5 mm for the entire cohort. For the patients who had initially been observed and had subsequently required intervention, the largest change in the ARSA cross-sectional diameter was observed 1 cm distally to the vessel ostium at a rate of 3.05 mm annually (95% confidence interval, 1.54-4.56; P < .001). No statistically significant changes in the annual growth rate of the aortic segments were observed in the entire cohort or for those patients who had undergone intervention (P > .05). CONCLUSIONS: The decision to intervene on an ARSA should be individualized by the presence of symptoms (eg, dysphagia lusoria) or complications (eg, dissection, concomitant aortic aneurysmal disease, enlarging Kommerell diverticulum). Asymptomatic patients with nonaneurysmal ARSA might not require any intervention and can be safely observed. Measurement of the cross-sectional ARSA diameter 1 cm distally to the ostium of the vessel might aid in the surveillance of vessel diameter changes. Additional studies are required to determine the specific size criteria as an indication for operative repair of asymptomatic Kommerell diverticulum.

Standardizing Methods of Reading CT Maximum Aortic Diameters Amongst Experts Reduces Variations and Discordance, Improving Accuracy.

BACKGROUND: There is no consensus on the method of obtaining abdominal aortic aneurysm (AAA) maximum diameters based on computed tomographic angiography, and the reproducibility and accuracy of different methods have recently been debated due to advancements in imaging. This study compared the two most common methods based on orthogonal planes and centerline of flow to determine the discordances and accuracy amongst experiences readers. METHODS: The computed tomographic angiography max diameters of 148 AAAs were measured by three experienced observers, including a vascular surgeon, a radiologist and an imaging cardiologist. Observers used two different methods with standardized protocols: multiplanar reformations based on orthogonal planes, and a software using 3D aortic reconstructions to create centerline flow lumen providing diameters based on cross sections perpendicular to this lumen. Agreements and reliability of measurement methods were assessed by intra-class correlation coefficient and Bland - Altman analysis. Discordances between measurements of the methods and the original reported measurement, as well as outside hospitals were compared. RESULTS: The average age of the cohort was 75 years and aortic diameters ranged from 3.8 to 9.6 cm. For orthogonal readings, there were agreements within 3 mm between 86% and 92% of the time, while centerline - reading agreement was between 88% and 94%, which was not statistically significant. The intra-class correlation coefficient was high between method type and between readers. Within methods, agreement was between 0.96 and 0.97, while within - reader agreement measures was between 0.96 and 0.98. In comparison to the original and the outside hospital reports, 10% ≥ of the original and 20% ≥ of the outside hospital reported measurements were discordant between the readers. CONCLUSION: Maximal AAA measurements can have substantial variability leading to clinical significance and change in patient management and outcomes. Based on the results, orthogonal and centerline measurement methods have equally high agreements and concordance within 3 mm and low variations at a high volume center. However, when compared to the official read reports, there is high discordance rates that can significantly alter patient outcomes. A standardized method of measurement maximum diameter can reduce variations and discordances among different methods.

Intelligent resolution: Integrating Cryo-EM with AI-driven multi-resolution simulations to observe the severe acute respiratory syndrome coronavirus-2 replication-transcription machinery in action.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) replication transcription complex (RTC) is a multi-domain protein responsible for replicating and transcribing the viral mRNA inside a human cell. Attacking RTC function with pharmaceutical compounds is a pathway to treating COVID-19. Conventional tools, e.g., cryo-electron microscopy and all-atom molecular dynamics (AAMD), do not provide sufficiently high resolution or timescale to capture important dynamics of this molecular machine. Consequently, we develop an innovative workflow that bridges the gap between these resolutions, using mesoscale fluctuating finite element analysis (FFEA) continuum simulations and a hierarchy of AI-methods that continually learn and infer features for maintaining consistency between AAMD and FFEA simulations. We leverage a multi-site distributed workflow manager to orchestrate AI, FFEA, and AAMD jobs, providing optimal resource utilization across HPC centers. Our study provides unprecedented access to study the SARS-CoV-2 RTC machinery, while providing general capability for AI-enabled multi-resolution simulations at scale.

Surface-tethered planar membranes containing the ß-barrel assembly machinery: a platform for investigating bacterial outer membrane protein folding.

The outer membrane of Gram-negative bacteria presents a robust physicochemical barrier protecting the cell from both the natural environment and acting as the first line of defense against antimicrobial materials. The proteins situated within the outer membrane are responsible for a range of biological functions including controlling influx and efflux. These outer membrane proteins (OMPs) are ultimately inserted and folded within the membrane by the ß-barrel assembly machine (Bam) complex. The precise mechanism by which the Bam complex folds and inserts OMPs remains unclear. Here, we have developed a platform for investigating Bam-mediated OMP insertion. By derivatizing a gold surface with a copper-chelating self-assembled monolayer, we were able to assemble a planar system containing the complete Bam complex reconstituted within a phospholipid bilayer. Structural characterization of this interfacial protein-tethered bilayer by polarized neutron reflectometry revealed distinct regions consistent with known high-resolution models of the Bam complex. Additionally, by monitoring changes of mass associated with OMP insertion by quartz crystal microbalance with dissipation monitoring, we were able to demonstrate the functionality of this system by inserting two diverse OMPs within the membrane, pertactin, and OmpT. This platform has promising application in investigating the mechanism of Bam-mediated OMP insertion, in addition to OMP function and activity within a phospholipid bilayer environment.

Evaluation of splenic accumulation and colocalization of immature reticulocytes and Plasmodium vivax in asymptomatic malaria: A prospective human splenectomy study.

BACKGROUND: A very large biomass of intact asexual-stage malaria parasites accumulates in the spleen of asymptomatic human individuals infected with Plasmodium vivax. The mechanisms underlying this intense tropism are not clear. We hypothesised that immature reticulocytes, in which P. vivax develops, may display high densities in the spleen, thereby providing a niche for parasite survival. METHODS AND FINDINGS: We examined spleen tissue in 22 mostly untreated individuals naturally exposed to P. vivax and Plasmodium falciparum undergoing splenectomy for any clinical indication in malaria-endemic Papua, Indonesia (2015 to 2017). Infection, parasite and immature reticulocyte density, and splenic distribution were analysed by optical microscopy, flow cytometry, and molecular assays. Nine non-endemic control spleens from individuals undergoing spleno-pancreatectomy in France (2017 to 2020) were also examined for reticulocyte densities. There were no exclusion criteria or sample size considerations in both patient cohorts for this demanding approach. In Indonesia, 95.5% (21/22) of splenectomy patients had asymptomatic splenic Plasmodium infection (7 P. vivax, 13 P. falciparum, and 1 mixed infection). Significant splenic accumulation of immature CD71 intermediate- and high-expressing reticulocytes was seen, with concentrations 11 times greater than in peripheral blood. Accordingly, in France, reticulocyte concentrations in the splenic effluent were higher than in peripheral blood. Greater rigidity of reticulocytes in splenic than in peripheral blood, and their higher densities in splenic cords both suggest a mechanical retention process. Asexual-stage P. vivax-infected erythrocytes of all developmental stages accumulated in the spleen, with non-phagocytosed parasite densities 3,590 times (IQR: 2,600 to 4,130) higher than in circulating blood, and median total splenic parasite loads 81 (IQR: 14 to 205) times greater, accounting for 98.7% (IQR: 95.1% to 98.9%) of the estimated total-body P. vivax biomass. More reticulocytes were in contact with sinus lumen endothelial cells in P. vivax- than in P. falciparum-infected spleens. Histological analyses revealed 96% of P. vivax rings/trophozoites and 46% of schizonts colocalised with 92% of immature reticulocytes in the cords and sinus lumens of the red pulp. Larger splenic cohort studies and similar investigations in untreated symptomatic malaria are warranted. CONCLUSIONS: Immature CD71+ reticulocytes and splenic P. vivax-infected erythrocytes of all asexual stages accumulate in the same splenic compartments, suggesting the existence of a cryptic endosplenic lifecycle in chronic P. vivax infection. Findings provide insight into P. vivax-specific adaptions that have evolved to maximise survival and replication in the spleen.

Genetic Diversity of Collaborative Cross Mice Controls Viral Replication, Clinical Severity, and Brain Pathology Induced by Zika Virus Infection, Independently of Oas1b.

The explosive spread of Zika virus (ZIKV) has been associated with major variations in severe disease and congenital afflictions among infected populations, suggesting an influence of host genes. We investigated how genome-wide variants could impact susceptibility to ZIKV infection in mice. We first describe that the susceptibility of Ifnar1-knockout mice is largely influenced by their genetic background. We then show that Collaborative Cross (CC) mice, which exhibit a broad genetic diversity, in which the type I interferon receptor (IFNAR) was blocked by an anti-IFNAR antibody expressed phenotypes ranging from complete resistance to severe symptoms and death, with large variations in the peak and the rate of decrease in the plasma viral load, in the brain viral load, in brain histopathology, and in the viral replication rate in infected cells. The differences in susceptibility to ZIKV between CC strains correlated with the differences in susceptibility to dengue and West Nile viruses between the strains. We identified highly susceptible and resistant mouse strains as new models to investigate the mechanisms of human ZIKV disease and other flavivirus infections. Genetic analyses revealed that phenotypic variations are driven by multiple genes with small effects, reflecting the complexity of ZIKV disease susceptibility in the human population. Notably, our results rule out the possibility of a role of the Oas1b gene in the susceptibility to ZIKV. Altogether, the findings of this study emphasize the role of host genes in the pathogeny of ZIKV infection and lay the foundation for further genetic and mechanistic studies.IMPORTANCE In recent outbreaks, ZIKV has infected millions of people and induced rare but potentially severe complications, including Guillain-Barré syndrome and encephalitis in adults. While several viral sequence variants were proposed to enhance the pathogenicity of ZIKV, the influence of host genetic variants in mediating the clinical heterogeneity remains mostly unexplored. We addressed this question using a mouse panel which models the genetic diversity of the human population and a ZIKV strain from a recent clinical isolate. Through a combination of in vitro and in vivo approaches, we demonstrate that multiple host genetic variants determine viral replication in infected cells and the clinical severity, the kinetics of blood viral load, and brain pathology in mice. We describe new mouse models expressing high degrees of susceptibility or resistance to ZIKV and to other flaviviruses. These models will facilitate the identification and mechanistic characterization of host genes that influence ZIKV pathogenesis.

Spinal drainage complications after aortic surgery.

OBJECTIVE/BACKGROUND: Spinal drain (SD) placement is an adjunct used in open and endovascular aortic surgery to mitigate the risk of spinal cord injury. SD placement can lead to subdural hematoma and intracranial hemorrhage (SDH/ICH). Previous studies have highlighted a correlation between incidence of SDH/ICH and amount of cerebrospinal fluid (CSF) drained. We have two philosophies of SD management in our institution. One protocol allows fluid removal for pressure >10 cm H2O with no volume restriction. A second, similar protocol restricts CSF drainage to <25 mL/h. We examined SD complications and the influence of volume restriction. METHODS: Patients were identified according to the Current Procedure Terminology codes for SD placement, thoracic endovascular aortic repair, fenestrated/branched endovascular aortic repair, endovascular abdominal aortic repair, and open thoracic or thoracoabdominal aortic repair between January 1, 2012, and December 31, 2015. Patients' demographics included age, gender, race, body mass index, and comorbidities such as hypertension, chronic obstructive pulmonary disease, stroke, transient ischemic attack, diabetes mellitus, bleeding disorder, and connective tissue disorders. Management protocol was classified as volume independent (VI) or volume dependent (VD) by physician order. Postoperative complications related to the SD were noted. RESULTS: We identified 948 patients who had an SD placed during the study period; 473 were done before aortic surgeries. A total of 364 patients (77%) underwent endovascular aortic surgery. The mean age at the time of procedure was 67.2 years, and 66% of patients were male. Thirty-nine patients (8.3%) were noted to have connective tissue disorders. Bloody SD placement occurred in 14 patients (3.1%) requiring rescheduling of the operation. SDH/ICH occurred in 11 patients (2.3%), postoperative blood tinged SD output in 94 patients (19.9 %), and 22 patients (4.7 %) had a CSF leak after SD removal. The incidence of SDH/ICH was not affected by the management protocol (2.6% VI vs 2.0% VD, P = .66), whereas the incidence of postoperative blood tinged SD output was significantly higher in the VI group (25.1% VI vs 15.0% VD, P = .006). Perioperative low-dose aspirin (81 mg) and prophylactic subcutaneous heparin did not increase the incidence of SDH/ICH. Postoperative thrombocytopenia was found to be associated with higher incidence of SDH/ICH (median 86,000 vs 113,000, P = .002). CONCLUSIONS: Severe complications of SD placement (SDH/ICH) occur in 2.3% of SD patients undergoing aortic surgery, and the risk is higher in the setting of postoperative thrombocytopenia. SD volume limitation, blood tinged drainage, antiplatelet medication, and low-dose heparin do not affect the risk of SDH/ICH. The risks of spinal drains for aortic surgery should be balanced against potential benefits.

Decreased transfusion requirements with use of acute normovolemic hemodilution in open aortic aneurysm repair.

OBJECTIVE: Acute normovolemic hemodilution (ANH) is an operative blood conservation technique involving the removal and storage of patient blood after the induction of anesthesia, with maintenance of normovolemia by crystalloid and/or colloid replacement. Developed and used predominately in cardiac surgery, ANH has been applied to the vascular surgery population. However, data regarding the effects on transfusion requirements in this population are limited. The objective of the present study was to compare the transfusion requirements and coagulopathy for patients who had undergone open abdominal aortic aneurysm repair (oAAAR) using ANH to those for patients who had received only product replacements, as clinically indicated. METHODS: We performed a retrospective review of patients who had undergone elective oAAAR at a quaternary aortic referral center from 2017 to 2019. Those eligible for ANH, with no active cardiac ischemia, no valvular disease, normal left ventricular and right ventricular function, chronic kidney disease stage <3, hematocrit >38%, and a normal coagulation profile were included in the present study. Patient demographics and characteristics and operative variables, including aneurysm extent, clamp site, visceral and renal ischemia time, operative time, and transfusion requirements, were collected. Postoperative morbidity, mortality, and length of stay were analyzed. The patients with and without ANH were matched and compared. Continuous measures were analyzed using Wilcoxon rank sum tests and t tests. RESULTS: During the study period, 209 oAAARs had been performed. Of the 209 patients, 76 had met the inclusion criteria. Of these 76 patients, 27 had undergone ANH and 49 had not. The patients with ANH had required fewer PRBC transfusions intraoperatively (median, 0 U; interquartile range [IQR], 0-1 U; median, 1 U; IQR, 0-2 U; P = .02), at 24 hours (median, 0 U; IQR, 0-1 U; vs median, 1 U; IQR, 0-2 U; P = .008), at 48 hours (median, 0 U; IQR, 0-1 U; vs median, 1 U; IQR, 0-2; P = .007), and throughout the admission (median, 0 U; IQR, 0-1 U; vs median, 2 U; IQR, 0-2 U; P = .011). No difference was found in the number of intraoperative platelet or cryoprecipitate transfusions. At 48 hours, the ANH group had had significantly greater platelet counts (142 ± 35.8 × 103/µL vs 124 ± 37.6 × 103/µL; P = .044), lower partial thromboplastin time, and lower international normalized ratio. No difference in myocardial infarction, return to the operating room, or mortality (one death overall). The ANH patients had a shorter length of stay (7.0 ± 2.7 vs 8.8 ± 4.8 days; P = .041). CONCLUSIONS: The use of ANH during oAAAR resulted in fewer intraoperative and postoperative PRBC transfusions with improved coagulation parameters and a shorter hospital length of stay.

Timing of repair of blunt thoracic aortic injuries in the thoracic endovascular aortic repair era.

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) is the preferred operative treatment of blunt thoracic aortic injuries (BTAIs). Its use is associated with improved outcomes compared with open surgical repair and nonoperative management. However, the optimal time from injury to repair is unknown and remains a subject of debate across different societal practice guidelines. The purpose of this study was to evaluate national trends in the management of BTAI, with a specific focus on the impact of timing of repair on outcomes. METHODS: Using the National Trauma Data Bank, we identified adult patients with BTAI between 2012 and 2017. Patients with prehospital or emergency department cardiac arrest or incomplete data sets were excluded from analysis. Patients were classified according to timing of repair: group 1, <24 hours; and group 2, ≥24 hours. The primary outcome evaluated was in-hospital mortality; secondary outcomes included overall hospital and intensive care unit length of stay. Multivariable logistic regression was performed to identify independent predictors of mortality. RESULTS: The analysis was completed for 2821 patients who underwent TEVAR for BTAI with known operative times. The overall mortality in the patient cohort was 8.4% (238/2821); 75% of patients undergoing TEVAR were repaired within 24 hours. Mortality was more than twofold greater in group 1 compared with group 2 (9.8% [207/2118] vs 4.4% [31/703]; P = .001). This mortality benefit persisted across injury severity groups and was independent of the presence of serious extrathoracic injuries. Logistic regression analysis, adjusting for age ≥65 years, Glasgow Coma Scale score ≤8, systolic blood pressure ≤90 mm Hg at admission, and serious extrathoracic injuries, showed a higher adjusted mortality in group 1 (odds ratio, 2.54; 95% confidence interval, 1.66-3.91; P = .001). CONCLUSIONS: The majority of patients with BTAI undergo endovascular repair within 24 hours of injury. Patients undergoing delayed repair have improved survival compared with those repaired within the first 24 hours of injury in spite of similar injury patterns and severity. In patients with BTAIs without signs of imminent rupture, delaying endovascular repair beyond 24 hours after injury should be considered.

Insights into amebiasis using a human 3D-intestinal model.

Entamoeba histolytica is the causative agent of amebiasis, an infectious disease targeting the intestine and the liver in humans. Two types of intestinal infection are caused by this parasite: silent infection, which occurs in the majority of cases, and invasive disease, which affects 10% of infected persons. To understand the intestinal pathogenic process, several in vitro models, such as cell cultures, human tissue explants or human intestine xenografts in mice, have been employed. Nevertheless, our knowledge on the early steps of amebic intestinal infection and the molecules involved during human-parasite interaction is scarce, in part due to limitations in the experimental settings. In the present work, we took advantage of tissue engineering approaches to build a three-dimensional (3D)-intestinal model that is able to replicate the general characteristics of the human colon. This system consists of an epithelial layer that develops tight and adherens junctions, a mucus layer and a lamina propria-like compartment made up of collagen containing macrophages and fibroblast. By means of microscopy imaging, omics assays and the evaluation of immune responses, we show a very dynamic interaction between E. histolytica and the 3D-intestinal model. Our data highlight the importance of several virulence markers occurring in patients or in experimental models, but they also demonstrate the involvement of under described molecules and regulatory factors in the amoebic invasive process.

Incidental Learning and Memory Deficits on a Computerized Symbol-Digit Modalities Test in Adults with HIV/AIDS.

OBJECTIVE: Incidental learning and memory, as well as processing speed, were examined in human immunodeficiency virus (HIV)-positive adults and a seronegative control group. METHODS: Participants completed a computerized Symbol-Digit Modalities Test (cSDMT) with two blocked conditions: a set of trials with the standard symbol-digit pairings and the second set with a rearranged symbol-digit pairings. RESULTS: HIV-positive adults showed slower overall reaction time compared to the HIV-negative group. More importantly, the most cognitively impaired HIV-positive group showed no interference in the rearranged set of symbol-digit pairings from the standard pairings on the cSDMT. CONCLUSION: The relative slowing, or interference, in the HIV-negative group and two HIV-positive groups (unimpaired and impaired) was quite large (between 122 and 131 ms). We argue that the lack of such relative slowing in the most cognitively impaired HIV-positive group indicates a deficit in incidental learning and memory.

Multilevel summation for periodic electrostatics using B-splines.

Fast methods for calculating two-body interactions have many applications, and for molecular science and cosmology, it is common to employ periodic boundary conditions. However, for the 1/r potential, the energy and forces are ill-defined. Adopted here is the model given by the classic Ewald sum. For the fast calculation of two-body forces, the most celebrated method is the fast multipole method and its tree-code predecessor. However, molecular simulations typically employ mesh-based approximations and the fast Fourier transform. Both types of methods have significant drawbacks, which, in most respects, are overcome by the less well-known multilevel summation method (MSM). Presented here is a realization of the MSM, which can be regarded as a multilevel extension of the (smoothed) particle mesh Ewald (PME) method, but with the Ewald softening replaced by one having a finite range. The two-level (single-grid) version of MSM requires fewer tuning parameters than PME and is marginally faster. Additionally, higher-level versions of MSM scale well to large numbers of processors, whereas PME and other two-level methods do not. Although higher-level versions of MSM are less efficient on a single processor than the two-level version, evidence suggests that they are more efficient than other methods that scale well, such as the fast multipole method and tree codes.

Covalently linked hydrogen bond donors: The other side of molecular frustration in deep eutectic solvents.

In this work, we investigated the effects of a single covalent link between hydrogen bond donor species on the behavior of deep eutectic solvents (DESs) and shed light on the resulting interactions at molecular scale that influence the overall physical nature of the DES system. We have compared sugar-based DES mixtures, 1:2 choline chloride/glucose [DES(g)] and 1:1 choline chloride/trehalose [DES(t)]. Trehalose is a disaccharide composed of two glucose units that are connected by an α-1,4-glycosidic bond, thus making it an ideal candidate for comparison with glucose containing DES(g). The differential scanning calorimetric analysis of these chemically close DES systems revealed significant difference in their phase transition behavior. The DES(g) exhibited a glass transition temperature of -58 °C and behaved like a fluid at higher temperatures, whereas DES(t) exhibited marginal phase change behavior at -11 °C and no change in the phase behavior at higher temperatures. The simulations revealed that the presence of the glycosidic bond between sugar units in DES(t) hindered free movement of sugar units in trehalose, thus reducing the number of interactions with choline chloride compared to free glucose molecules in DES(g). This was further confirmed using quantum theory of atoms in molecule analysis that involved determination of bond critical points (BCPs) using Laplacian of electron density. The analysis revealed a significantly higher number of BCPs between choline chloride and sugar in DES(g) compared to DES(t). The DES(g) exhibited a higher amount of charge transfer between the choline cation and sugar, and better interaction energy and enthalpy of formation compared to DES(t). This is a result of the ability of free glucose molecules to completely surround choline chloride in DES(g) and form a higher number of interactions. The entropy of formation for DES(t) was slightly higher than that for DES(g), which is a result of fewer interactions between trehalose and choline chloride. In summary, the presence of the glycosidic bond between the sugar units in trehalose limited their movement, thus resulting in fewer interactions with choline chloride. This limited movement in turn diminishes the ability of the hydrogen bond donor to disrupt the molecular packing within the lattice structure of the hydrogen bond acceptor (and vice versa), a crucial factor that lowers the melting point of DES mixtures. This inability to move due to the presence of the glycosidic bond in trehalose significantly influences the physical state of the DES(t) system, making it behave like a semi-solid material, whereas DES(g) behaves like a liquid material at room temperature.

Outcomes of Hypogastric Coverage and Occlusion during Endovascular Treatment of Aortoiliac Occlusive Disease.

BACKGROUND: The risk of hypogastric occlusion (HO) following bare-metal stent (BMS) coverage of the hypogastric origin during endovascular treatment of aortoiliac occlusive disease (AIOD) is unclear. This study sought to determine the rate and clinical significance of HO following BMS coverage during iliac stenting for complex AIOD. METHODS: Consecutive patients undergoing elective iliac stenting for AIOD from 2010-2018 at Cleveland Clinic were reviewed. Patients with BMS coverage of a patent hypogastric origin were included. Rate of HO were determined by review of intraoperative angiography and follow up imaging. Predictors of HO were identified by univariable and multivariable logistic regression. Outcomes were compared between those who did and did not develop HO. RESULTS: There were 251 patients (338 limbs) with BMS coverage of the hypogastric origin during treatment of AIOD. Lesion severity was classified as TASC C/D in 249/338 (73.7%) of cases. Bilateral hypogastric coverage occurred in 93/251 (37.1%) patients. Hypogastric patency was 78.1% at 24-months following coverage. Recanalization of an ipsilateral external iliac artery (EIA) occlusion was predictive of HO (HR 3.12, 95% CI: 1.33, 7.34; P= 0.009). Increased luminal diameter of the hypogastric origin protected against HO (HR 0.64; 95% CI: 0.47, 0.88; P= 0.006). Perioperative outcomes were no different between patients with and without HO. There were no cases of gluteal necrosis, spinal cord ischemia, or pelvic organ ischemia. Four-year mortality and limb salvage were not affected by HO. HO was associated with decreased primary patency of ipsilateral iliac stents and increased risk of ipsilateral reintervention (HR 5.49; 95% CI: 1.82, 16.58; P= 0.002). CONCLUSIONS: HO is relatively infrequent following BMS coverage during treatment of AIOD. Luminal diameter of the hypogastric origin and ipsilateral EIA occlusion are associated with occlusion. HO is well tolerated in AIOD, though it is potentially associated with increased risk iliac stent occlusion and reintervention.