TMEM106B coding variant is protective and deletion detrimental in a mouse model of tauopathy

TMEM106B is a risk modifier of multiple neurological conditions, where a single coding variant and multiple non-coding SNPs influence the balance between susceptibility and resilience. Two key questions that emerge from past work are whether the lone T185S coding variant contributes to protection, and if the presence of TMEM106B is helpful or harmful in the context of disease. Here, we address both questions while expanding the scope of TMEM106B study from TDP-43 to models of tauopathy. We generated knockout mice with constitutive deletion of TMEM106B, alongside knock-in mice encoding the T186S knock-in mutation (equivalent to the human T185S variant), and crossed both with a P301S transgenic tau model to study how these manipulations impacted disease phenotypes. We found that TMEM106B deletion accelerated cognitive decline, hind limb paralysis, tau pathology, and neurodegeneration. TMEM106B deletion also increased transcriptional correlation with human AD and the functional pathways enriched in KO:tau mice aligned with those of AD. In contrast, the coding variant protected against tau-associated cognitive decline, synaptic impairment, neurodegeneration, and paralysis without affecting tau pathology. Our findings reveal that TMEM106B is a critical safeguard against tau aggregation, and that loss of this protein has a profound effect on sequelae of tauopathy. Our study further demonstrates that the coding variant is functionally relevant and contributes to neuroprotection downstream of tau pathology to preserve cognitive function.

GLP-1 Receptor Agonists Promote Weight Loss Among People with HIV

BACKGROUND

Weight gain and associated metabolic complications are increasingly prevalent among people with HIV (PWH). Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are incretin-based therapies for diabetes and weight management that have been shown to result in substantial weight loss; however, studies of their effects in PWH are limited.

METHODS

A retrospective single-center cohort study was conducted among PWH who were taking GLP-1RAs at UC San Diego Owen Clinic between 2/1/2021 to 2/1/2023. Baseline clinical data were collected and changes in weight, body mass index (BMI), and hemoglobin A1C (A1C) before starting GLP-1RAs compared to the most recent clinic visit were calculated (with a minimum of 3 months follow-up time required). Logistic regression was performed to identify variables associated with >5% of total body weight loss.

RESULTS

A total of 225 patients received on average 13 months of GLP-1RA therapy, with 85 (37.8%) achieving the maximum GLP-1RA dose. GLP-1RA therapy resulted, on average, in a loss of 5.4 kg, decrease in BMI by 1.8 kg/m2, and decrease in A1C by 0.6%. In the multivariable analysis, higher baseline BMI [OR 1.10 (1.03-1.16)], treatment duration of GLP-1RA therapy greater than 6 months [OR 3.12 (1.49-6.49], and use of tirzepatide [OR 5.46 (1.44-20.76)] were significantly more likely to be associated with >5% weight loss.

CONCLUSIONS

Use of GLP-1RAs led to declines in weight, BMI, and hemoglobin A1C among PWH and offers an additional strategy to address weight gain and diabetes.

Observation of time-reversal symmetry breaking in the band structure of altermagnetic RuO2

Altermagnets are an emerging elementary class of collinear magnets. Unlike ferromagnets, their distinct crystal symmetries inhibit magnetization while, unlike antiferromagnets, they promote strong spin polarization in the band structure. The corresponding unconventional mechanism of time-reversal symmetry breaking without magnetization in the electronic spectra has been regarded as a primary signature of altermagnetism but has not been experimentally visualized to date. We directly observe strong time-reversal symmetry breaking in the band structure of altermagnetic RuO2 by detecting magnetic circular dichroism in angle-resolved photoemission spectra. Our experimental results, supported by ab initio calculations, establish the microscopic electronic structure basis for a family of interesting phenomena and functionalities in fields ranging from topological matter to spintronics, which are based on the unconventional time-reversal symmetry breaking in altermagnets.

How sudden- versus slow-onset environmental events affect self-identification as an environmental migrant: Evidence from Vietnamese and Kenyan survey data

In response to changing climatic conditions, people are increasingly likely to migrate. However, individual-level survey data reveal that people mainly state economic, social, or political reasons as the main drivers for their relocation decision-not environmental motives or climate change specifically. To shed light on this discrepancy, we distinguish between sudden-onset (e.g., floods and storms) and slow-onset (e.g., droughts and salinity) climatic changes and argue that the salience of environmental conditions in individuals' migration decisions is shaped by the type of climate event experienced. Empirically, we combine individual-level surveys with geographic information on objective climatic changes in Vietnam and Kenya. The empirical evidence suggests that sudden-onset climate events make individuals more likely to link environmental conditions to their migration decision and, hence, to identify themselves as "environmental migrants." Regression analyses support these results and are consistent with the view that slow-onset events tend to be linked with migration decisions that are more economically motivated.

Facile Synthesis of Ru Nanoboxes with a Hexagonal Close-Packed Structure by Templating with Ag Nanocubes and Their Catalytic Properties

Noble-metal nanoboxes offer an attractive form of nanomaterials for catalytic applications owing to their open structure and highly efficient use of atoms. Herein, we report the facile synthesis of Ag-Ru core-shell nanocubes and then Ru nanoboxes with a hexagonal close-packed (hcp) structure, as well as evaluation of their catalytic activity toward a model hydrogenation reaction. By adding a solution of Ru(acac)3 in ethylene glycol (EG) dropwise to a suspension of silver nanocubes in EG at 170 °C, Ru atoms are generated and deposited onto the entire surface of a nanocube. As the volume of the RuIII precursor is increased, Ru atoms are also produced through a galvanic replacement reaction, generating Ag-Ru nanocubes with a hollow interior. The released Ag+ ions are then reduced by EG and deposited back onto the nanocubes. By selectively etching away the remaining Ag with aqueous HNO3 , the as-obtained Ag-Ru nanocubes are transformed into Ru nanoboxes, whose walls are characterized by an hcp structure and an ultrathin thickness of a few nanometers. Finally, we evaluated the catalytic properties of the Ru nanoboxes with two different wall thicknesses by using a model hydrogenation reaction; both samples showed excellent performance.

The Suitability of a Large Particle Hyaluronic Acid Filler for the Treatment of Temporal Hollowing

BACKGROUND

Hyaluronic acid (HA) fillers may be manufactured to have distinctive physical properties that optimize their use for specific indications. Fillers manufactured with large gel calibration (particle size; HA-V) may be particularly suitable for volumizing large surface areas such as the temporal hollows.

OBJECTIVE

To investigate the safety and effectiveness of HA-V for the treatment of temporal hollows.

MATERIALS AND METHODS

A prospective, open-label, single-cohort, clinical trial was conducted. Twenty-six women who presented with bilateral temporal hollows at baseline were recruited. All subjects received treatment with HA-V and were observed at 4 to 5 in-person visits over 16 weeks. Subjective and objective measures of safety and efficacy parameters were collected through 2- and 3-dimensional imagery, questionnaires/scales (i.e., subject satisfaction, global aesthetic improvement, temporal hollowing severity), and adverse event diaries.

RESULTS

To achieve optimal correction, the investigator used an average of 1.70 syringes per subject, per side. All treatments were performed using a bolus injection technique to place the product on the periosteum (bone) of the temporal region. Following optimal correction, all subjects (100%) displayed improvement in their global aesthetic appearance, and 25 of 26 subjects (96.15%) displayed ≥1 grade improvement on the temporal volume scale. Subject satisfaction was high, with 91.3% of subjects being satisfied with the appearance of their temporal regions following optimal correction.

CONCLUSION

In this pivotal trial, HA-V was evidenced to have an excellent safety profile and proven efficacy up to 16 weeks, making it a suitable HA filler for volumization of the temporal region.

Adaptive platform trials: the impact of common controls on type one error and power

Platform trials offer a framework to study multiple interventions in one trial with the opportunity of opening and closing arms. The use of common controls can increase efficiency as compared to individual controls. The need for multiplicity adjustment because of common controls is currently a debate among researchers, pharmaceutical companies, and regulators. The impact of common controls on the type one error in a fixed platform trial, i.e. when all treatments start and end recruitment at the same time, has been discussed in the literature before. We complement these findings by investigating the impact of a common control on the type one error and power in a flexible platform trial, i.e. when one arm joins the platform later. We derived the correlation of test statistics to assess the impact of the overlap and compared the results to a trial with individual controls. Furthermore, we evaluate the power, and the impact of multiplicity adjustment on the power in fixed and flexible platform trials. These methodological considerations are complemented by a regulatory guideline review. With multiple arms, the FWER is inflated when no multiplicity adjustment is applied. However, the FWER inflation is smaller with common controls than with individual controls. Even after multiplicity adjustment, a trial with common controls is often beneficial in terms of sample size and power. However, in some cases, the trial with common controls loses the efficiency gain and it might be advisable to run a separate trial rather than joining a platform trial.

The TMEM106B T186S coding variant increases neurite arborization and synaptic density in primary hippocampal neurons

The lysosomal protein TMEM106B was identified as a risk modifier of multiple dementias including frontotemporal dementia and Alzheimer's disease. The gene comes in two major haplotypes, one associated with disease risk, and by comparison, the other with resilience. Only one coding polymorphism distinguishes the two alleles, a threonine-to-serine substitution at residue 185 (186 in mouse), that is inherited in disequilibrium with multiple non-coding variants. Transcriptional studies suggest synaptic, neuronal, and cognitive preservation in human subjects with the protective haplotype, while murine in vitro studies reveal dramatic effects of TMEM106B deletion on neuronal development. Despite this foundation, the field has not yet resolved whether coding variant is biologically meaningful, and if so, whether it has any specific effect on neuronal phenotypes. Here we studied how loss of TMEM106B or expression of the lone coding variant in isolation affected transcriptional signatures in the mature brain and neuronal structure during development in primary neurons. Homozygous expression of the TMEM106B T186S variant in knock-in mice increased cortical expression of genes associated with excitatory synaptic function and axon outgrowth, and promoted neurite branching, dendritic spine density, and synaptic density in primary hippocampal neurons. In contrast, constitutive TMEM106B deletion affected transcriptional signatures of myelination without altering neuronal development in vitro. Our findings show that the T186S variant is functionally relevant and may contribute to disease resilience during neurodevelopment.

"In vivo biosynthesis of N,N-dimethyltryptamine, 5-MeO-N,N-dimethyltryptamine, and bufotenine in E.coli"

N,N-dimethyltryptamine (DMT), 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) and 5-hydroxy-N,N-dimethyltryptamine (bufotenine) are psychedelic tryptamines found naturally in both plants and animals and have shown clinical potential to help treat mental disorders, such as anxiety and depression. Advances in both metabolic and genetic engineering make it possible to engineer microbes as cell factories to produce DMT and its aforementioned derivatives to meet demand for ongoing clinical study. Here, we present the development of a biosynthetic production pathway for DMT, 5-MeO-DMT, and bufotenine in the model microbe Escherichia coli. Through the application of genetic optimization techniques and process optimization in benchtop fermenters, the in vivo production of DMT in E. coli was observed. DMT production with tryptophan supplementation reached maximum titers of 74.7 ± 10.5 mg/L under fed batch conditions in a 2-L bioreactor. Additionally, we show the first reported case of de novo production of DMT (from glucose) in E. coli at a maximum titer of 14.0 mg/L and report the first example of microbial 5-MeO-DMT and bufotenine production in vivo. This work provides a starting point for further genetic and fermentation optimization studies with the goal to increase methylated tryptamine production metrics to industrially competitive levels.

On the use of non-concurrent controls in platform trials: a scoping review

BACKGROUND

Platform trials gained popularity during the last few years as they increase flexibility compared to multi-arm trials by allowing new experimental arms entering when the trial already started. Using a shared control group in platform trials increases the trial efficiency compared to separate trials. Because of the later entry of some of the experimental treatment arms, the shared control group includes concurrent and non-concurrent control data. For a given experimental arm, non-concurrent controls refer to patients allocated to the control arm before the arm enters the trial, while concurrent controls refer to control patients that are randomised concurrently to the experimental arm. Using non-concurrent controls can result in bias in the estimate in case of time trends if the appropriate methodology is not used and the assumptions are not met.

METHODS

We conducted two reviews on the use of non-concurrent controls in platform trials: one on statistical methodology and one on regulatory guidance. We broadened our searches to the use of external and historical control data. We conducted our review on the statistical methodology in 43 articles identified through a systematic search in PubMed and performed a review on regulatory guidance on the use of non-concurrent controls in 37 guidelines published on the EMA and FDA websites.

RESULTS

Only 7/43 of the methodological articles and 4/37 guidelines focused on platform trials. With respect to the statistical methodology, in 28/43 articles, a Bayesian approach was used to incorporate external/non-concurrent controls while 7/43 used a frequentist approach and 8/43 considered both. The majority of the articles considered a method that downweights the non-concurrent control in favour of concurrent control data (34/43), using for instance meta-analytic or propensity score approaches, and 11/43 considered a modelling-based approach, using regression models to incorporate non-concurrent control data. In regulatory guidelines, the use of non-concurrent control data was considered critical but was deemed acceptable for rare diseases in 12/37 guidelines or was accepted in specific indications (12/37). Non-comparability (30/37) and bias (16/37) were raised most often as the general concerns with non-concurrent controls. Indication specific guidelines were found to be most instructive.

CONCLUSIONS

Statistical methods for incorporating non-concurrent controls are available in the literature, either by means of methods originally proposed for the incorporation of external controls or non-concurrent controls in platform trials. Methods mainly differ with respect to how the concurrent and non-concurrent data are combined and temporary changes handled. Regulatory guidance for non-concurrent controls in platform trials are currently still limited.

TMEM106B regulates microglial proliferation and survival in response to demyelination

TMEM106B, a lysosomal transmembrane protein, has been closely associated with brain health. Recently, an intriguing link between TMEM106B and brain inflammation has been discovered, but how TMEM106B regulates inflammation is unknown. Here, we report that TMEM106B deficiency in mice leads to reduced microglia proliferation and activation and increased microglial apoptosis in response to demyelination. We also found an increase in lysosomal pH and a decrease in lysosomal enzyme activities in TMEM106B-deficient microglia. Furthermore, TMEM106B loss results in a significant decrease in the protein levels of TREM2, an innate immune receptor essential for microglia survival and activation. Specific ablation of TMEM106B in microglia results in similar microglial phenotypes and myelination defects in mice, supporting the idea that microglial TMEM106B is critical for proper microglial activities and myelination. Moreover, the TMEM106B risk allele is associated with myelin loss and decreased microglial numbers in humans. Collectively, our study unveils a previously unknown role of TMEM106B in promoting microglial functionality during demyelination.

The clinical features and genomic epidemiology of carbapenem-resistant Acinetobacter baumannii infections at a tertiary hospital in Vietnam

OBJECTIVES

To characterise the clinical features of A. baumannii infections and investigate the phylogenetic structure and transmission dynamics of A. baumannii in Vietnam.

METHODS

Between 2019 and 2020, a surveillance of A. baumannii (AB) infections was conducted at a tertiary hospital in Ho Chi Minh City, Vietnam. Risk factors for in-hospital mortality were analyzed using logistic regressions. Whole-genome sequence data were used to characterise genomic species, sequence types (STs), antimicrobial resistance genes, surface antigens and phylogenetic relatedness of AB isolates.

RESULTS

Eighty-four patients with AB infections were enrolled in the study, 96% of whom were hospital-acquired. Half of the AB isolates were identified from ICU-admitted patients while the remaining isolates were from non-ICU patients. The overall in-hospital mortality was 56%, with associated risk factors including advanced age, ICU stay, exposure to mechanical ventilation/central venous catheterization, pneumonia as source of AB infection, prior use of linezolid/aminoglycosides, and AB treatment with colistin-based therapy. Nearly 91% of isolates were carbapenem-resistant; 92% were multidrug-resistant and 6% were colistin-resistant. ST2, ST571 and ST16 were the three dominant CRAB genotypes, exhibiting distinct AMR gene profiles. Phylogenetic analysis of CRAB ST2 isolates together with previously published ST2 collection provided evidence of intra- and inter-hospital transmission of this clone.

CONCLUSIONS

Our study highlights a high prevalence of carbapenem resistance and multidrug resistance in A. baumannii and elucidates the spread of CRAB within and between hospitals. Strengthening infection control measures and routine genomic surveillance are crucial to reducing the spread of CRAB and timely detecting novel pan drug-resistant variants.

TMEM106B coding variant is protective and deletion detrimental in a mouse model of tauopathy

TMEM106B is a risk modifier for a growing list of age-associated dementias including Alzheimer’s and frontotemporal dementia, yet its function remains elusive. Two key questions that emerge from past work are whether the conservative T185S coding variant found in the minor haplotype contributes to protection, and whether the presence of TMEM106B is helpful or harmful in the context of disease. Here we address both issues while extending the testbed for study of TMEM106B from models of TDP to tauopathy. We show that TMEM106B deletion accelerates cognitive decline, hindlimb paralysis, neuropathology, and neurodegeneration. TMEM106B deletion also increases transcriptional overlap with human AD, making it a better model of disease than tau alone. In contrast, the coding variant protects against tau-associated cognitive decline, neurodegeneration, and paralysis without affecting tau pathology. Our findings show that the coding variant contributes to neuroprotection and suggest that TMEM106B is a critical safeguard against tau aggregation.

Dehydration Alters Transcript Levels in the Mosquito Midgut, Likely Facilitating Rapid Rehydration following a Bloodmeal

The mosquito midgut is an important site for bloodmeal regulation while also acting as a primary site for pathogen exposure within the mosquito. Recent studies show that exposure to dehydrating conditions alters mosquito bloodfeeding behaviors as well as post-feeding regulation, likely altering how pathogens interact with the mosquito. Unfortunately, few studies have explored the underlying dynamics between dehydration and bloodmeal utilization, and the overall impact on disease transmission dynamics remains veiled. In this study, we find that dehydration-based feeding in the yellow fever mosquito, Aedes aegypti, prompts alterations to midgut gene expression, as well as subsequent physiological factors involving water control and post-bloodfeeding (pbf) regulation. Altered expression of ion transporter genes and aquaporin 2 (AQP2) in the midgut of dehydrated mosquitoes as well as the rapid reequilibration of hemolymph osmolality after a bloodmeal indicate an ability to expedite fluid and ion processing. These alterations ultimately indicate that female A. aegypti employ mechanisms to ameliorate the detriments of dehydration by imbibing a bloodmeal, providing an effective avenue for rehydration. Continued research into bloodmeal utilization and the resulting effects on arthropod-borne transmission dynamics becomes increasingly important as drought prevalence is increased by climate change.

Left ventricular assist device inflow obstruction

Inflow cannula obstruction is a rare complication of left ventricular assist device implantation. In this report, we present a case of inflow obstruction that was successfully treated with left ventricle myectomy and mitral valvectomy. Transesophageal echocardiogram was essential in diagnosing this condition.

Frustrative nonreward and the basal ganglia: Chemogenetic inhibition and excitation of the nucleus accumbens and globus pallidus externus during reward downshift

Frustrative nonreward contributes to anxiety disorders and addiction, and is included in the Research Domain Criteria initiative as a relevant endophenotype. These experiments explored the role of the basal ganglia in consummatory reward downshift (cRD) using inhibitory and excitatory DREADDs (designer receptors exclusively activated by designer drugs) infused in either the nucleus accumbens (NAc) or one of its downstream targets, the globus pallidus externus (GPe). NAc inhibition did not disrupt consummatory suppression during a 32-to-2% (Experiment 1) or 8-to-2% sucrose downshift (Experiment 2). However, NAc excitation enhanced consummatory suppression during a 32-to-2% sucrose downshift (Experiment 1). GPe inhibition caused a trend toward increased consummatory suppression after a 32-to-2% sucrose downshift, whereas GPe excitation eliminated consummatory suppression after an 8-to-2% sucrose downshift (Experiment 3). Chemogenetic manipulations of NAc and GPe had no detectable effects on open field activity. The effects of DREADD activation via clozapine N-oxide (CNO) administration were compared to controls that carried the DREADDs, but received vehicle injections. There was no evidence that CNO or vehicle injections in virus vector control (VVC) animals affected cRD or OF activity after either CNO or vehicle injections. NAc and GPe excitation led to opposite results in the cRD task, providing evidence that the basal ganglia circuit has a function in frustrative nonreward in the absence of detectable motor effects.

Association of Neighborhood Racial and Ethnic Composition and Historical Redlining With Built Environment Indicators Derived From Street View Images in the US

Importance

Racist policies (such as redlining) create inequities in the built environment, producing racially and ethnically segregated communities, poor housing conditions, unwalkable neighborhoods, and general disadvantage. Studies on built environment disparities are usually limited to measures and data that are available from existing sources or can be manually collected.

Objective

To use built environment indicators generated from online street-level images to investigate the association among neighborhood racial and ethnic composition, the built environment, and health outcomes across urban areas in the US.

Design, Setting, and Participants

This cross-sectional study was conducted using built environment indicators derived from 164 million Google Street View images collected from November 1 to 30, 2019. Race, ethnicity, and socioeconomic data were obtained from the 2019 American Community Survey (ACS) 5-year estimates; health outcomes were obtained from the Centers for Disease Control and Prevention 2020 Population Level Analysis and Community Estimates (PLACES) data set. Multilevel modeling and mediation analysis were applied. A total of 59 231 urban census tracts in the US were included. The online images and the ACS data included all census tracts. The PLACES data comprised survey respondents 18 years or older. Data were analyzed from May 23 to November 16, 2022.

Main Outcomes and Measures

Model-estimated association between image-derived built environment indicators and census tract (neighborhood) racial and ethnic composition, and the association of the built environment with neighborhood racial composition and health.

Results

The racial and ethnic composition in the 59 231 urban census tracts was 1 160 595 (0.4%) American Indian and Alaska Native, 53 321 345 (19.5%) Hispanic, 462 259 (0.2%) Native Hawaiian and other Pacific Islander, 17 166 370 (6.3%) non-Hispanic Asian, 35 985 480 (13.2%) non-Hispanic Black, and 158 043 260 (57.7%) non-Hispanic White residents. Compared with other neighborhoods, predominantly White neighborhoods had fewer dilapidated buildings and more green space indicators, usually associated with good health, and fewer crosswalks (eg, neighborhoods with predominantly minoritized racial or ethnic groups other than Black residents had 6% more dilapidated buildings than neighborhoods with predominantly White residents). Moreover, the built environment indicators partially mediated the association between neighborhood racial and ethnic composition and health outcomes, including diabetes, asthma, and sleeping problems. The most significant mediator was non-single family homes (a measure associated with homeownership), which mediated the association between neighborhoods with predominantly minority racial or ethnic groups other than Black residents and sleeping problems by 12.8% and the association between unclassified neighborhoods and asthma by 24.2%.

Conclusions and Relevance

The findings in this cross-sectional study suggest that large geographically representative data sets, if used appropriately, may provide novel insights on racial and ethnic health inequities. Quantifying the impact of structural racism on social determinants of health is one step toward developing policies and interventions to create equitable built environment resources.

Redo heart transplant without allogeneic blood transfusion

Allogeneic blood transfusion in cardiac surgery is associated with increased morbidity, mortality, and health care costs. We report a successful case of third-time redo sternotomy second-time redo heart transplantation without allogeneic blood transfusion owing to the multiple blood conservation strategies used throughout the perioperative period.

Optimizing outpatient oncology consult workflow using time-driven activity-based costing: Efficiency and financial impacts

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Background: Clinical efficiency is a key component of value-based healthcare, patient satisfaction, staff burnout, and institutional operational capacity. The objective of this study was to identify clinic inefficiencies using time driven activity-based costing (TDABC) and evaluate the implementation of a new clinical workflow in high volume, outpatient radiation oncology clinics. Methods: We conducted an IRB-approved quality improvement study in the Gastrointestinal (GI), Genitourinary (GU), and Thoracic Radiation (TRO) Oncology departments at a large academic cancer center and four additional network sites (HALs). TDABC methodology was used to create process maps and optimize consult workflow. Patient encounter metrics were captured utilizing a real-time status function in the electronic medical record (Epic Systems). Anonymous patient satisfaction telephone surveys were administered to patients at the HALs. Hourly wages were determined based on 2021 U.S. Bureau of Labor Statistics. Pre- vs post-implementation metrics were compared using the Mann-Whitney U test. Results: Consult data for 1328 patients pre-intervention and 1234 post-intervention across all sections was included. Median overall cycle time was reduced by 21% in GI (19 min, p < 0.001), 18% in GU (16 min, p < 0.001), and 12% in HALs (9 min, p < 0.001). The median interval between rooming and being seen by the attending physician decreased by 13% in GI (7 min, p < 0.001), 16% in GU (9 min, p < 0.001), 21% in TRO (10 min, p < 0.001), and 9% in HALS (4 min, p < 0.005). For each consult, there was a median financial savings of $29 for GI, $24 for GU, $5 for TRO, and $14 for HALs per consult. From patient satisfaction surveys (95/177), 99% of patients reported their providers spent adequate time with them, 85% reported their appointment began on time, and 91% reported being seen by a care provider in a timely manner. Conclusions: TDABC is a successful method to identify opportunities to improve clinical efficiency. Implementing workflow changes based upon these findings led to substantial reduction in overall encounter cycle times and patient wait times across multiple departments. Furthermore, patient satisfaction was high and there were significant financial savings with the new workflow. These findings may also have implications for reducing staff burnout and expanding clinical capacity across the magnitude of clinical enterprise.[Table: see text]

Abstract P3055: Combined Metabolomic And Transcriptomic Profiling Approaches Reveal The Cardiac Response To High-fat Diet

The response of vital organs to different types of nutrition or diet is a fundamental question in physiology. It is unclear how different diets can alter cardiac metabolism and function. We examined the cardiac response to 4 weeks of high-fat diet in adult mice, measuring cardiac metabolites and mRNA. Metabolomics showed dramatic differences after high-fat diet, including increases in several acyl-carnitine species. The RNAseq data showed changes consistent with adaptations to use more fatty acid as substrate and an increase in the anti-oxidant protein catalase. Changes in mRNA were correlated to changes in protein level for several highly responsive genes, including catalase and HMGcs2. We also found significant sex differences in both metabolomics and RNAseq datasets, both at baseline and after high fat diet. This work reveals the response of a vital organ to dietary intervention at both metabolomic and transcriptomic levels, which is a fundamental question in physiology that may have relevance for cardiovascular diseases. This work also reveals significant sex differences in cardiac metabolites and gene expression.

Figure 1: Metabolomic changes after HFD; electron microscopy shows changes in mitochondrial morphology. A. Principal component analysis (loading) of metabolites demonstrates that the first two principal components (PC) cluster the samples into 4 groups. PC1 + PC2 account for 85.47% of the proportion of variance in this metabolomic dataset.B. Graph of acyl-carnitine species, dots with lines indicated mean +/- SEM. “C#” refers to the number of carbon atoms in the lipid, that is C16 is palmitoylcarnitine, C14 is myristoylcarnitine, etc. N= 10 hearts for each group. The comparison of control (chow) to HFD is highly statistically significant by 2-way ANOVA, p<0.0001.C. Representative examples of electron microscopy from cardiac ventricular samples.D. Graphs of average mitochondrial area (um 2 ) and average number of mitochondria per high-power image. N= 4 hearts for each group, * indicates significantly different by t-test.

A robust experimental and computational analysis framework at multiple resolutions, modalities and coverages

The ability to study cancer-immune cell communication across the whole tumor section without tissue dissociation is needed, especially for cancer immunotherapy development, which requires understanding of molecular mechanisms and discovery of more druggable targets. In this work, we assembled and evaluated an integrated experimental framework and analytical process to enable genome-wide scale discovery of ligand-receptors potentially used for cellular crosstalks, followed by targeted validation. We assessed the complementarity of four different technologies: single-cell RNA sequencing and Spatial transcriptomic (measuring over >20,000 genes), RNA In Situ Hybridization (RNAscope, measuring 4-12 genes) and Opal Polaris multiplex protein staining (4-9 proteins). To utilize the multimodal data, we implemented existing methods and also developed STRISH (Spatial TRanscriptomic In Situ Hybridization), a computational method that can automatically scan across the whole tissue section for local expression of gene (e.g. RNAscope data) and/or protein markers (e.g. Polaris data) to recapitulate an interaction landscape across the whole tissue. We evaluated the approach to discover and validate cell-cell interaction in situ through in-depth analysis of two types of cancer, basal cell carcinoma and squamous cell carcinoma, which account for over 70% of cancer cases. We showed that inference of cell-cell interactions using scRNA-seq data can misdetect or detect false positive interactions. Spatial transcriptomics still suffers from misdetecting lowly expressed ligand-receptor interactions, but reduces false discovery. RNAscope and Polaris are sensitive methods for defining the location of potential ligand receptor interactions, and the STRISH program can determine the probability that local gene co-expression reflects true cell-cell interaction. We expect that the approach described here will be widely applied to discover and validate ligand receptor interaction in different types of solid cancer tumors.

Management Strategies for Descending Thoracic Aortic Thrombus: A Review of the Literature

Descending thoracic aortic thrombus (DTAT) is an under-recognized source of systemic emboli with potential catastrophic consequences. Imaging modalities such as echocardiography, computed tomography, magnetic resonance imaging, and angiography can help identify and characterize the extent of embolic events. Established guidelines regarding the management of DTAT are currently lacking. Multiple treatment modalities are available; however, the effectiveness of each approach remains to be determined. In this study, we performed a review to examine the clinical presentation, diagnostic methods and findings, and outcomes of various treatment options for patients with DTAT. Medical management is the least invasive and most frequently chosen initial approach, offering a high reported success rate, whereas endovascular therapy can have a role in thrombus exclusion should conservative management fail.

Transcatheter Versus Surgical Aortic Valve Replacement in Young, Low-risk Patients with Severe Aortic Stenosis

Aortic stenosis is a common form of acquired degenerative valvular disease associated with poor survival after the onset of symptoms. Treatment options for patients with aortic stenosis in addition to medical therapy include surgical aortic valve replacement (SAVR) with either tissue or mechanical valves, or transcatheter aortic valve replacement (TAVR) with either balloon-expandable or self-expanding valves via either transfemoral or alternative access routes. In this review, the authors discuss the current evidence and special considerations regarding the use of TAVR versus SAVR in the management of severe aortic stenosis in young (<65 years of age), low-risk patients, highlighting the history of aortic stenosis treatment, the current guidelines and recommendations, and important issues that remain to be addressed. Ultimately, until ongoing clinical trials with long-term follow-up data shed light on whether interventions for aortic stenosis can be broadened to a low-risk population, TAVR in young, low-risk patients should be undertaken with caution and with guidance from a multidisciplinary heart team.

Genomic epidemiology, antimicrobial resistance and virulence factors of Enterobacter cloacae complex causing potential community-onset bloodstream infections in a tertiary care hospital of Nepal

Objectives

Community-onset bloodstream infections (BSIs) caused by carbapenemase-producing Enterobacter cloacae complex (ECC) species are increasing internationally. This observation suggests that ECC are emerging pathogens, requiring for detailed understanding on their genomic epidemiology including transmission dynamics and antimicrobial resistance profiles.

Patients and methods

We performed WGS on 79 Enterobacter spp. isolated from the patients with clinically significant BSIs and admitted to emergency department of a major tertiary hospital in Nepal between April 2016 and October 2017.

Results

We identified 5 species and 13 STs of ECC. Enterobacter xiangfangensis ST171, one of the globally emerging carbapenem resistant ECC clones with epidemic potential, was the most prevalent (42%). Phylogenetic analysis showed a large (>19 400 SNPs) core genome SNP distance across major STs, which was minimal (<30 SNPs) among the isolates of each prevalent ST, suggesting the relatively recent importation of major STs followed by local clonal expansions. Genomic evidence for resistance to all major antimicrobial classes except for colistin and macrolides was detected. A limited number of isolates also carried bla NDM-1 (n = 2) and bla OXA-48 (n = 1) carbapenemase genes. Virulence factors encoding siderophores (24%), T6SSD (25%) and fimbriae (54%) were detected.

Conclusions

Our study highlighted that MDR ECC clones are important pathogens of BSIs in community. Though of low prevalence, carbapenem resistance observed in our ECC isolates raised concern about further community dissemination, underscoring the need for community surveillance to identify MDR ECC clones with epidemic potential.

Effects of demolishing abandoned buildings on firearm violence: a moderation analysis using aerial imagery and deep learning

PURPOSE

Demolishing abandoned buildings has been found to reduce nearby firearm violence. However, these effects might vary within cities and across time scales. We aimed to identify potential moderators of the effects of demolitions on firearm violence using a novel approach that combined machine learning and aerial imagery.

METHODS

Outcomes were annual counts of fatal and non-fatal shootings in Rochester, New York, from 2000 to 2020. Treatment was demolitions conducted from 2009 to 2019. Units of analysis were 152×152 m grid squares. We used a difference-in-differences approach to test effects: (A) the year after each demolition and (B) as demolitions accumulated over time. As moderators, we used a built environment typology generated by extracting information from aerial imagery using convolutional neural networks, a deep learning approach, combined with k-means clustering. We stratified our main models by built environment cluster to test for moderation.

RESULTS

One demolition was associated with a 14% shootings reduction (incident rate ratio (IRR)=0.86, 95% CI 0.83 to 0.90, p<0.001) the following year. Demolitions were also associated with a long-term, 2% reduction in shootings per year for each cumulative demolition (IRR=0.98, 95% CI 0.95 to 1.00, p=0.02). In the stratified models, densely built areas with higher street connectivity displayed following-year effects, but not long-term effects. Areas with lower density and larger parcels displayed long-term effects but not following-year effects.

CONCLUSIONS

The built environment might influence the magnitude and duration of the effects of demolitions on firearm violence. Policymakers may consider complementary programmes to help sustain these effects in high-density areas.

Host and gut microbial tryptophan metabolism and type 2 diabetes: an integrative analysis of host genetics, diet, gut microbiome and circulating metabolites in cohort studies

OBJECTIVE

Tryptophan can be catabolised to various metabolites through host kynurenine and microbial indole pathways. We aimed to examine relationships of host and microbial tryptophan metabolites with incident type 2 diabetes (T2D), host genetics, diet and gut microbiota.

METHOD

We analysed associations between circulating levels of 11 tryptophan metabolites and incident T2D in 9180 participants of diverse racial/ethnic backgrounds from five cohorts. We examined host genome-wide variants, dietary intake and gut microbiome associated with these metabolites.

RESULTS

Tryptophan, four kynurenine-pathway metabolites (kynurenine, kynurenate, xanthurenate and quinolinate) and indolelactate were positively associated with T2D risk, while indolepropionate was inversely associated with T2D risk. We identified multiple host genetic variants, dietary factors, gut bacteria and their potential interplay associated with these T2D-relaetd metabolites. Intakes of fibre-rich foods, but not protein/tryptophan-rich foods, were the dietary factors most strongly associated with tryptophan metabolites. The fibre-indolepropionate association was partially explained by indolepropionate-associated gut bacteria, mostly fibre-using Firmicutes. We identified a novel association between a host functional LCT variant (determining lactase persistence) and serum indolepropionate, which might be related to a host gene-diet interaction on gut Bifidobacterium, a probiotic bacterium significantly associated with indolepropionate independent of other fibre-related bacteria. Higher milk intake was associated with higher levels of gut Bifidobacterium and serum indolepropionate only among genetically lactase non-persistent individuals.

CONCLUSION

Higher milk intake among lactase non-persistent individuals, and higher fibre intake were associated with a favourable profile of circulating tryptophan metabolites for T2D, potentially through the host-microbial cross-talk shifting tryptophan metabolism toward gut microbial indolepropionate production.

POS1165 ASSOCIATION OF LDHD RARE VARIANTS WITH EARLY-ONSET GOUT IN TWO FAMILIES WITH AN ADDITIONAL ASSOCIATION OF RHBG VARIANT IN ONE

Background

Elevated lactate is known to favor urine urate reabsorption by the URAT1 urate/anion exchanger. Autosomal recessive gout caused by pathogenic variant in the LDHD gene encoding for D-lactate deshydrogenase has been recently identified in a large consanguineous Bedouin-Israeli kindred (1).

Objectives

We report here on two families in whom early-onset gout was linked to other variants leading to deficient D-LDH enzymes.

Methods

Studies of the two families were approved by appropriate Ethics committees. Whole exome sequencing (WES) was used to identify the genetic cause of familial gout. Dosages of D-lactate were performed on immediately frozen serum and urine samples by ELISA, using a D-lactate colorimetric assay kit (Abcam ab83429).

Results

Family 1 was Melanesian, living in the Lifou island of New Caledonia. The two index patients were two sisters who developed gout at the age of 13 and 16 years respectively. When seen at the ages of 25 and 27 years, they both had severe gout with frequent polyarticular flares, and multiple tophi and destructive arthropathies in the earliest age of onset one. WES, performed on the 2 affected sisters, their non-consanguine parents, and an unaffected brother, showed that the 2 affected sisters carried homozygous rare variant in DLDH gene (NM_153486.3: c.206 C>T; rs1035398551). This variant was at heterozygote level in both parents and absent in the unaffected brother. It was considered as probably damaging according to in silico prediction software. No association with any other gene was found.

The c.206C>T variant in LDHD was searched by Sanger sequencing method in 13 other extended family members. One 23 year-old brother of the two diseased sisters with atypical MTP flares, high uricemia and double contours at US examination of his MTPs, carried the c.206 C>T variant at the homozygous level. Three other heterozygous patients were found; two of whom were male with late-onset gout, the third one being a non-menopausal female with no gout. No variant carrier was found in the other 9 genotyped family members. The 3 homozygous patients for the c.206 C>T variant had very high hyperuricemia (range 738-834 was searched by Sanger sequencing method in 13 other extended family members. One 23 year-old brother of the two diseased sisters with atypical MTP flares, high uricemia and double contours at US examination of had very low or no D-lactate in plasma and urine. L-lactate blood and urine levels were normal in all subjects.

Family 2 was Vietnamese, living in a remote area of central Vietnam. The two affected children suffered from an extremely severe, destructive gout, which started at the age of 21 years in a daughter and at the age of 9 in her youngest brother, who had developed for the last 3 years, dysarthria, night shakes, memory loss, urine incontinence and an inability to read and count and died at the age of 34, a few months after being seen by us. WES was performed in the two probands, their father and mother (who denied consanguinity), and an unaffected brother. An undescribed variant in LDHD (NM_153486.3: c.1363dupG) was identified in homozygous level in the 2 juvenile gout patients and at the heterozygous level in their 2 parents and unaffected brother. This variant led to a frameshift followed by a stop codon p.(AlaGly432fsTer58). In addition, the two juvenile gout patients were homozygous for an undescribed frameshift (NR_046115.1: c.1064dup) variant of the RHBG gene encoding for a Rhesus Blood Group family ammonium transporter. The two parents carried the heterozygous variant which was not identified in the non-gout brother.

Conclusion

We report on 2 families in whom autosomal recessive juvenile gout was due to rare or undescribed, damaging LDHD gene variants. In addition, we observed in the Vietnamese family, an additional non-described frameshift homozygous variant in RHBG, the pathophysiological role of which deserves to be investigated.

References

[1]Drabkin M et al. Hyperuricemia and gout caused by missense mutation in D-lactate dehydrogenase. J Clin Invest. 2019;129:5163-5168

Disclosure of Interests

Thomas Bardin Consultant of: leo Pharma, Yves-Marie Ducrot: None declared, Quang Nguyen: None declared, Emmanuel Letavernier: None declared, Hang-Korng Ea: None declared, Frederic Touzain: None declared, Duc Minh Do: None declared, Julien Corot: None declared, Yan Barguil: None declared, Antoine Biron: None declared, Pascal Richette: None declared, Corinne Collet: None declared

A fatal outbreak of neonatal sepsis caused by mcr-10 carrying Enterobacter kobei in a tertiary care hospital in Nepal

BACKGROUND

Enterobacter kobei is an emerging cause of outbreak of nosocomial infections in neonatal intensive care units (NICUs). Between July and September of 2016, an NICU in a tertiary care hospital of Nepal observed an abrupt increase in the number of neonatal sepsis cases caused by Enterobacter spp. infecting 11 of 23 admitted neonates, 5 of whom died of an exacerbated sepsis.

AIM

Main aims of this study were to confirm the suspected outbreak, identify environmental source of infection, and characterize genetic determinants of antimicrobial resistance (AMR) and virulence of the pathogen.

METHODS

We performed whole genome sequencing of all Enterobacter spp. isolated from blood cultures of septic neonates admitted to NICU between May 2016 and December 2017. Also, an environmental sampling was intensified from fortnightly to weekly during the outbreak.

FINDINGS

The genomic analysis revealed that 10 of 11 non-duplicated E. kobei isolated from neonatal blood cultures between July and September 2016 were clonal, confirming the outbreak. The isolates carried AMR genes including bla_AmpC and mcr-10 conferring reduced susceptibility to carbapenem and colistin respectively. The environmental sampling however failed to isolate any Enterobacter spp. Reinforcement of aseptic protocols in invasive procedures, hand hygiene, environmental decontamination, fumigation, and secluded care of culture positive cases successfully terminated the outbreak.

CONCLUSION

Our study underscored the need to implement stringent infection control measures to prevent infection outbreaks. Further, for the first time, we report the emergence of carbapenem and colistin non-susceptible E. kobei carrying mcr-10 gene as an important cause of nosocomial neonatal sepsis in an NICU.

Investigating SARS-CoV-2 Test Positivity Calculations Across US Jurisdictions

Purpose

Throughout the COVID-19 pandemic, many US epidemiologists and policymakers turned to an indicator called test positivity, or the percent of tests coming back positive for SARS-CoV-2, to contextualize COVID-19 case counts with testing volume. But the nation's patchworked health data infrastructure, composed of 56 systems managed by each state and territory, complicated efforts to calculate the metric in a comparable way across US jurisdictions. We set out to map jurisdictional reporting differences in test positivity and investigate whether they interfered with its effectiveness and comparability as an indicator. Understanding these differences is important because jurisdictional test positivity informed consequential policy and individuals’ understanding of risk in their communities.

Methods & Materials

We surveyed the health department websites of all US states and territories to examine how these jurisdictions were presenting test positivity on COVID-19 dashboards. When details about definitions were unavailable on jurisdictional websites, we reached out to jurisdictional public health officials for clarification. We also scored jurisdictions' presentations against best practices we identified for calculating the metric.

Results

Among the 48 states and territories posting test positivity values, we observed no consensus on how to calculate the metric—jurisdictions used different units, test types, averaging techniques, and dating schemes. By looking at data for jurisdictions that posted multiple test positivity metrics, we observed that these definitional differences could result in variations from 31% to 300%. Only four states were following all ten of the best practices for reporting test positivity.

Conclusion

The sheer number of ways states and territories define test positivity is alarming, given how much the indicator influenced US COVID-19 policy. Based on our survey, we believe the confidence of regulators in the precision and national comparability of test positivity is misplaced: The metric's value reflects state and territorial reporting decisions as much as actual viral prevalence. These findings underscore the need to invest in centralized public health infrastructure and create national reporting standards to improve unity of state reporting.

Evaluating the Quality of Federal SARS-CoV-2 Diagnostic Testing Data

Purpose

In April 2020, the US Department of Health and Human Services (HHS) and the US Centers for Disease Control and Prevention established the COVID-19 Electronic Laboratory Reporting program (CELR) to collect data on SARS-CoV-2 laboratory tests. Over the course of the following year, the federal government, partnering with the Association for Public Health Laboratories, onboarded every state to submit laboratory results to this system—the first of its kind in the US. We set out to evaluate the quality of data collected by CELR.

Methods & Materials

We compared jurisdiction-level data collected through CELR and published by HHS to the testing data published by jurisdictions on their health department webpages. Because jurisdictions define their testing data differently, we anticipated some differences from federal testing data. However, jurisdictions also tend to prioritize their dashboard reporting—since it is what is used for policy decisions like reopening—so we hypothesized that differences from federal data absent a definitional explanation could point to problems with federal data. Where we found differences between jurisdictional and federal data, we conducted interviews with public health officials to understand their cause.

Results

Of the 56 states and territories, as of April 2021 (the first month when all states were onboarded to CELR), 38 had federal total data that diverges from state data by more than 5%. Of those states, the differences of 27 could not be explained by definitional factors. Based on our interviews, we identified three problems: non-electronic reporting streams, out-of-date surveillance systems, and deduplication of laboratory data.

Conclusion

The federal testing dataset displays major unresolved quality problems, and because states present testing data so differently, state-published data forms a poor alternative to federal datasets. The federal government, which is uniquely positioned to provide testing data on infectious diseases, must work to improve the quality of laboratory data submissions by states. To support better national laboratory data, the United States should invest in updating state and laboratory data surveillance infrastructure—including updates to state surveillance systems and laboratory system updates to eliminate outdated reporting methods like faxes—and in creating more national laboratory data infrastructure.

A Randomized, Crossover-Controlled Evaluator-Blinded Trial Evaluating Cannula- vs Needle-Assisted Hyaluronic Acid Injections for Infraorbital Deformities

BACKGROUND

Periorbital deformities can be corrected utilizing hyaluronic acid injections. However, previous studies have not evaluated the effect of utilizing different injection techniques (eg, a needle vs cannula) on efficacy and safety.

OBJECTIVES

The authors sought to investigate the efficacy and safety of HA for the correction of periorbital deformities when utilizing either needle or cannula-assisted injections.

METHODS

This was a prospective, randomized-controlled (with crossover), evaluator-blinded study. Forty-two patients with a mean age of 44.82 ± 11.62 years were recruited. Patients underwent 2 treatment sessions, spaced 2 weeks apart, and attended 1 follow-up visit at Week 4, following the last treatment. Patients were randomized in a 3:3:1 ratio, whereby 18 patients received injections by needle, 18 received injections by cannula, and 6 were randomized to act as their own control at baseline. Those in the control group were randomized (n = 3) to needle or cannula injections at Week 4 and proceeded with the same visit schedule as those treated at baseline. At Weeks 2 and 4 posttreatment, patient satisfaction was evaluated and information on adverse effects was collected. A blinded reviewer assessed patient imagery utilizing standardized efficacy scales.

RESULTS

Chi-square tests did not reveal any associations between treatment group and efficacy, safety, or patient satisfaction scores (P ≥ 0.05). Adverse effects reported in patient diaries were mild to moderate in nature and expected.

CONCLUSIONS

For the treatment of infraorbital deformities, hyaluronic acid injections performed utilizing either a cannula or needle result in similarly high efficacy and safety ratios.

LEVEL OF EVIDENCE: 2

Bloodmeal regulation in mosquitoes curtails dehydration-induced mortality, altering vectorial capacity

Mosquitoes readily lose water when exposed to any humidity less than that of near saturated air unless mitigated, leading to shifts in behavior, survival, distribution, and reproduction. In this study, we conducted a series of physiological experiments on two prominent species in the Culicinae subfamily: Culex pipiens, a vector of West Nile virus, and Aedes aegypti, a vector of yellow fever and Zika to examine the effects of dehydration. We exposed C. pipiens and A. aegypti to non-dehydrating conditions (saturated air), dehydrating conditions (air at a 0.89 kPa saturation vapor pressure deficit), several recovery conditions, as well as to bloodfeeding opportunities. We show that dehydrated mosquitoes increase bloodfeeding propensity, improve retention, and decrease excretion of a post-dehydration bloodmeal. In addition, mosquitoes that take a bloodmeal prior to dehydration exposure show increased survival over non-bloodfed counterparts. Dehydration-induced alterations in survival, reproduction, and bloodfeeding propensity of C. pipiens and A. aegypti resulted in marked changes to vectorial capacity. Ultimately, these results become increasingly important as drought intensifies in association with climate change and mosquitoes become more likely to experience arid periods.

Allele-Selective Locked Nucleic Acid Gapmers for the Treatment of Fibrodysplasia Ossificans Progressiva Knock Down the Pathogenic ACVR1R206H Transcript and Inhibit Osteogenic Differentiation

Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant disorder characterized by episodic heterotopic ossification. The median life span of people with this disorder is ∼40 years, and currently, there is no effective treatment available. More than 95% of cases are caused by a recurrent mutation (c.617G>A; R206H) of Activin A receptor, type I (ACVR1)/Activin receptor-like kinase-2 (ALK2), a bone morphogenetic protein type I receptor. The mutation renders ACVR1 responsive to activin A, which does not activate wild-type ACVR1. Ectopic activation of ACVR1^R206H by activin A induces heterotopic ossification. Since ACVR1^R206H is a hyperactive receptor, a promising therapeutic strategy is to decrease the activity of mutated ACVR1. To accomplish this goal, we developed locked nucleic acid (LNA) gapmers. These are short DNA oligonucleotides with LNA modification at both ends. They induce targeted mRNA degradation and specific knockdown of gene expression. We demonstrated that some of these gapmers efficiently knocked down ACVR1^R206H expression at RNA levels, while ACVR1^WT was mostly unaffected in human FOP fibroblasts. Also, the gapmers suppressed osteogenic differentiation induced by ACVR1^R206H and activin A. These gapmers may be promising drug candidates for FOP. This novel strategy will also pave the way for antisense-mediated therapy of other autosomal dominant disorders.

Genomic insights into the circulation of pandemic fluoroquinolone-resistant extra-intestinal pathogenic Escherichia coli ST1193 in Vietnam

Extra-intestinal pathogenic Escherichia coli (ExPEC) ST1193, a globally emergent fluoroquinolone-resistant clone, has become an important cause of bloodstream infections (BSIs) associated with significant morbidity and mortality. Previous studies have reported the emergence of fluoroquinolone-resistant ExPEC ST1193 in Vietnam; however, limited data exist regarding the genetic structure, antimicrobial resistance (AMR) determinants and transmission dynamics of this pandemic clone. Here, we performed genomic and phylogenetic analyses of 46 ST1193 isolates obtained from BSIs and healthy individuals in Ho Chi Minh City, Vietnam, to investigate the pathogen population structure, molecular mechanisms of AMR and potential transmission patterns. We further examined the phylogenetic structure of ST1193 isolates in a global context. We found that the endemic E. coli ST1193 population was heterogeneous and highly dynamic, largely driven by multiple strain importations. Several well-supported phylogenetic clusters (C1-C6) were identified and associated with distinct bla _CTX-M variants, including bla _CTXM-27 (C1-C3, C5), bla _CTXM-55 (C4) and bla _CTXM-15 (C6). Most ST1193 isolates were multidrug-resistant and carried an extensive array of AMR genes. ST1193 isolates also exhibited the ability to acquire further resistance while circulating in Vietnam. There were phylogenetic links between ST1193 isolates from BSIs and healthy individuals, suggesting these organisms may both establish long-term colonization in the human intestinal tract and induce infections. Our study uncovers factors shaping the population structure and transmission dynamics of multidrug-resistant ST1193 in Vietnam, and highlights the urgent need for local One Health genomic surveillance to capture new emerging ExPEC clones and to better understand the origins and transmission patterns of these pathogens.

Rapid Deployment Valves Are Advantageous in the Redo Setting: A Single-Centre Retrospective Study

Background

The spectrum on how to manage aortic valve disease continues to widen. The purpose of this study is to add further clarification to the role of rapid deployment valves (RDVs) by comparing their outcomes with traditional sutured valves (TSVs) in the reoperative aortic valve replacement (AVR) setting.

Methods

This study was a retrospective review of all patients undergoing a second surgical reoperation for aortic valve disease. Patients were categorized into 2 groups: RDV and TSV. Cox proportional hazards regression models were used to determine the association between exposures of interest and the primary and secondary outcomes, after adjusting for all the baseline characteristics. The primary outcome was major adverse cardiovascular events (MACE) within 3 years, which was the composite of all-cause death, readmission for myocardial infarct, readmission for stroke, and readmission for heart failure.

Results

A total of 307 patients made up the study population from 2010 to 2019. Of those, 254 patients received TSV, and 53 patients received RDV. RDV patients were significantly older than TSV patients by 10 years, on average. Shorter cardiopulmonary bypass (CPB) times were found with the RDV group. There was no significant difference in the primary outcome of MACE within 3 years.

Conclusions

This single-centre large cohort study of patients with reoperative AVR found that RDVs facilitate smoother operations by saving 1 hour of cross-clamp time and CPB time. Furthermore, RDVs have comparable outcomes with TSVs, despite the significantly older patient population.

Chronic respiratory disease disparity between American Indian/Alaska Native and white populations, 2011-2018

BACKGROUND

American Indian/Alaska Native (AI/AN) populations have been disproportionately affected by chronic respiratory diseases for reasons incompletely understood. Past research into disease disparity using population-based surveys mostly focused on state-specific factors. The present study investigates the independent contributions of AI/AN racial status and other socioeconomic/demographic variables to chronic respiratory disease disparity in an 11-state region with historically high AI/AN representation. Using data from the Behavioral Risk Factor Surveillance System (BRFSS) spanning years 2011-2018, this work provides an updated assessment of disease disparity and potential determinants of respiratory health in AI/AN populations.

METHODS

This cross-sectional study used data from the BRFSS survey, 2011-2018. The study population included AI/AN and non-Hispanic white individuals resident in 11 states with increased proportion of AI/AN individuals. The yearly number of respondents averaged 75,029 (62878-87,350) which included approximately 5% AI/AN respondents (4.5-6.3%). We compared the yearly adjusted prevalence for chronic respiratory disease, where disease status was defined by self-reported history of having asthma and/or chronic obstructive pulmonary disease (COPD). Multivariable logistic regression was performed to determine if being AI/AN was independently associated with chronic respiratory disease. Covariates included demographic (age, sex), socioeconomic (marital status, education level, annual household income), and behavioral (smoking, weight morbidity) variables.

RESULTS

The AI/AN population consistently displayed higher adjusted prevalence of chronic respiratory disease compared to the non-Hispanic white population. However, the AI/AN race/ethnicity characteristic was not independently associated with chronic respiratory disease (OR, 0.93; 95% CI, 0.79-1.10 in 2017). In contrast, indicators of low socioeconomic status such as annual household income of <$10,000 (OR, 2.02; 95% CI, 1.64-2.49 in 2017) and having less than high school education (OR, 1.37; 95% CI, 1.16-1.63 in 2017) were positively associated with disease. These trends persisted for all years analyzed.

CONCLUSIONS

This study highlighted that AI/AN socioeconomic burdens are key determinants of chronic respiratory disease, in addition to well-established risk factors such as smoking and weight morbidity. Disease disparity experienced by the AI/AN population is therefore likely a symptom of disproportionate socioeconomic challenges they face. Further promotion of public health and social service efforts may be able to improve AI/AN health and decrease this disease disparity.

Abstract 1534: Mesothelin isoform 2 is a novel target for allogenic CARγδT cell therapy in solid tumors

Mesothelin (MSLN) is a tumor-associated antigen over-expressed on the cell surface of various malignant tumor cells, including majority of mesothelioma and ovarian cancer. MSLN-directed therapy has been intensively studied in preclinical and clinical settings. However, the clinical efficacy and safety of mesothelin-targeted therapy remains to be demonstrated. To identify a safe and effective target for CAR-T cell therapy in solid tumors, we used artificial intelligent platform developed with public and private RNA transcription database to identify cancer-associated antigens caused by alternative spicing. One of interesting targets is an alternative spicing isoform from MSLN. Human MSLN transcript has at least three isoforms. The isoform 1 is the predominant transcript detected in normal and tumor tissues and has been a promising target for cancer immunotherapy. The isoform 2 is the minor transcript using alternatively spliced exons producing 8 additional amino acids insertion compared to isoform 1. The isoform 3 produces a truncated and soluble MSLN. Our data demonstrated that MSLN isoform 2 is specifically expressed in ovarian cancers but not normal tissues, confirmed by Q-PCR studies. Furthermore, we generated mouse hybridoma antibodies specifically targeting MSLN isoform 2. The antibody specificity was screened and confirmed by ELISA-based reaction to MSLN isoform 2-specific peptide and flow cytometry-based binding to 293T cells overexpressing MSLN isoform 2 but not isoform 1 proteins. We further detected the endogenous MSLN isoform 2 expression in human mesothelioma cell line NCI H226 and further confirmed MSLN isoform 2 expression on human primary mesothelioma and ovarian cancer tissue but not normal tissues by immunohistochemistry staining. To study if targeting MSLN isoform 2 with chimeric antigen receptor (CAR) can control the tumor growth, we made CAR retrovirus construct and showed that genetically modified allogenic gamma-delta T cells expressing CAR for MSLN isoform 2 can kill human mesothelioma cells in vitro and in vivo. In summary, we have demonstrated that MSLN isoform 2 is a tumor-specific antigen, which can be targeted for CAR-T cell therapy.

Citation Format: Xiaohong Wang, Yibin Chen, Anupama Gopisetty, Leonardo Mirandola, Lucia Piccotti, Quynh Nguyen, Maurizio Chiriva-Internati. Mesothelin isoform 2 is a novel target for allogenic CARγδT cell therapy in solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1534.

Abstract 1535: Allogenic CAR iNKT as a cell therapy platform targeting tumor antigen Isomesothelin

Effective chimeric antigen receptor (CAR) T-cell therapy targeting B-cell malignancies has paved the way for alternate strategies targeting cancer. Current active research is directed towards development of safe, allogeneic off the shelf cell (OTS) therapy products. This could be potentially a step forward in the targeted cancer immunotherapy field. Invariant NKT cells (iNKT) are deemed as one of the unconventional T-cell populations with semi invariantly re-arranged TCR. They recognize lipid antigens Via CD1d, an MHC Class 1 like molecule. Recognition of CD1d expressed on various hematopoietic cells is important for targeted tumor specific iNKT cytotoxicity in various leukemia, lymphoma malignancies. Through the recent years, CAR-iNKT adoptive cell therapy has drawn excitement and interest because of their intrinsic anti-tumor property. More specifically CAR-iNKTs have been shown to target solid tumors such as neuroblastoma in preclinical studies and proceeded to phase 1 clinical trials. The innate ability of iNKT cells to kill tumor cells and also cause very less GVHD provides an extremely attractive platform for developing OTS product. Allogeneic CAR iNKT cells have been less explored for cancer immunotherapy. Although the relative percentage of iNKTs are very low in peripheral blood (~0.01% of T-lymphocytes), we report an efficient method of enrichment and expanding a large and pure population of iNKTs and genetically modify them for targeting solid tumor antigens such as Isomesothelin (IsoMSLN), an alternative splice variant of mesothelin. Many pre-clinical studies have been assessed targeting mesothelin, a tumor associated antigen overexpressed in malignant cells. A safe allogenic CAR targeted therapy for IsoMSLN has yet to be demonstrated. iNKTs expanded and transduced with our novel protocol targeting IsoMSLN, are highly cytotoxic and suggests a central memory phenotype that could potentially persist longer in vivo.

Citation Format: Anupama Gopisetty, Yibin Chen, Quynh Nguyen, Maurizio Chiriva-Internati. Allogenic CAR iNKT as a cell therapy platform targeting tumor antigen Isomesothelin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1535.

Uncoupling of macrophage inflammation from self-renewal modulates host recovery from respiratory viral infection

Tissue macrophages self-renew during homeostasis and produce inflammatory mediators upon microbial infection. We examined the relationship between proliferative and inflammatory properties of tissue macrophages by defining the impact of the Wnt/β-catenin pathway, a central regulator of self-renewal, in alveolar macrophages (AMs). Activation of β-catenin by Wnt ligand inhibited AM proliferation and stemness, but promoted inflammatory activity. In a murine influenza viral pneumonia model, β-catenin-mediated AM inflammatory activity promoted acute host morbidity; in contrast, AM proliferation enabled repopulation of reparative AMs and tissue recovery following viral clearance. Mechanistically, Wnt treatment promoted β-catenin-HIF-1α interaction and glycolysis-dependent inflammation while suppressing mitochondrial metabolism and thereby, AM proliferation. Differential HIF-1α activities distinguished proliferative and inflammatory AMs in vivo. This β-catenin-HIF-1α axis was conserved in human AMs and enhanced HIF-1α expression associated with macrophage inflammation in COVID-19 patients. Thus, inflammatory and reparative activities of lung macrophages are regulated by β-catenin-HIF-1α signaling, with implications for the treatment of severe respiratory diseases.