Dibutyl phthalate released by solitary female locusts mediates sexual communication at low density.

Sex pheromones play a crucial role in mate location and reproductive success. Insects face challenges in finding mates in low-density environments. The population dynamics of locusts vary greatly, ranging from solitary individuals to high-density swarms, leading to multiple-trait divergence between solitary and gregarious phases. However, differences in sexual communication between solitary and gregarious locusts have not been sufficiently explored. Herein, we found that solitary locusts but not gregarious ones heavily rely on a single compound, dibutyl phthalate (DBP), for sexual communication. DBP is abundantly released by solitary female locusts and elicits strong attraction of male solitary and gregarious locusts. Solitary adult males display much higher electrophysiological responses to DBP than adult females. Additionally, LmigOr13 was identified as the DBP-specific odorant receptor expressed in neurons housed in basiconic sensilla. Male LmigOr13-/- mutants generated by CRISPR/Cas9 have low electrophysiological responses and behavioral attraction to DBP in both laboratory and field cage experiments. Notably, the attractiveness of DBP to male locusts becomes more evident at lower population densities imposed by controlling the cage size. This finding sheds light on the utilization of a sex pheromone to promote reproductive success in extremely low-density conditions and provides important insights into alternative approaches for population monitoring of locusts.

Development of a liver disease-specific large language model chat interface using retrieval-augmented generation.

BACKGROUND AND AIMS: Large language models (LLMs) have significant capabilities in clinical information processing tasks. Commercially available LLMs, however, are not optimized for clinical uses and are prone to generating hallucinatory information. Retrieval-augmented generation (RAG) is an enterprise architecture that allows the embedding of customized data into LLMs. This approach "specializes" the LLMs and is thought to reduce hallucinations. APPROACH AND RESULTS: We developed "LiVersa," a liver disease-specific LLM, by using our institution's protected health information-complaint text embedding and LLM platform, "Versa." We conducted RAG on 30 publicly available American Association for the Study of Liver Diseases guidance documents to be incorporated into LiVersa. We evaluated LiVersa's performance by conducting 2 rounds of testing. First, we compared LiVersa's outputs versus those of trainees from a previously published knowledge assessment. LiVersa answered all 10 questions correctly. Second, we asked 15 hepatologists to evaluate the outputs of 10 hepatology topic questions generated by LiVersa, OpenAI's ChatGPT 4, and Meta's Large Language Model Meta AI 2. LiVersa's outputs were more accurate but were rated less comprehensive and safe compared to those of ChatGPT 4. RESULTS: We evaluated LiVersa's performance by conducting 2 rounds of testing. First, we compared LiVersa's outputs versus those of trainees from a previously published knowledge assessment. LiVersa answered all 10 questions correctly. Second, we asked 15 hepatologists to evaluate the outputs of 10 hepatology topic questions generated by LiVersa, OpenAI's ChatGPT 4, and Meta's Large Language Model Meta AI 2. LiVersa's outputs were more accurate but were rated less comprehensive and safe compared to those of ChatGPT 4. CONCLUSIONS: In this demonstration, we built disease-specific and protected health information-compliant LLMs using RAG. While LiVersa demonstrated higher accuracy in answering questions related to hepatology, there were some deficiencies due to limitations set by the number of documents used for RAG. LiVersa will likely require further refinement before potential live deployment. The LiVersa prototype, however, is a proof of concept for utilizing RAG to customize LLMs for clinical use cases.

The association between mean arterial pressure and acute kidney injury reversal among patients with decompensated cirrhosis.

BACKGROUND AND AIMS: This study informs how mean arterial pressure (MAP) impacts acute kidney injury (AKI) recovery among all patients hospitalized with cirrhosis, regardless of etiology. APPROACH AND RESULTS: We identified incident AKI episodes among subjects in our cohort of patients with decompensated cirrhosis. AKI was defined as a ≥50% increase in creatinine from an outpatient baseline (≥7 days prior) that required hospitalization. Linear mixed effects models were completed to determine the impact between AKI recovery, MAP, and time. To determine the impact of MAP on AKI reversal, we completed time-dependent Cox regression models with time beginning at the time of peak creatinine and ending at death, discharge, or AKI reversal, among those hospitalized with AKI and those with persistent AKI (≥48 h) We identified 702 hospitalized patients with cirrhosis with AKI. We found those with AKI reversal had, on average, higher MAP (2.1 mm Hg, p <0.05) and a greater increase in MAP over time (0.1 mm Hg per hour, p <0.001). Among all 702 hospitalized patients with AKI and adjusted for confounders, each 5 mm Hg increase in MAP was associated with 1.07× the hazard of AKI reversal ( p <0.01). Similarly, among those with persistent AKI after adjusting for confounders, each 5 mm Hg increase in MAP was associated with a 1.19× greater likelihood of AKI reversal ( p <0.001). DISCUSSION: Our data demonstrate that MAP significantly increases the likelihood of AKI recovery regardless of severity or injury or AKI phenotype. We believe these data highlight the importance of MAP as a clinical tool to promote kidney function recovery among patients with cirrhosis hospitalized with AKI.

Evaluating the positive predictive value of code-based identification of cirrhosis and its complications utilizing GPT-4.

BACKGROUND: Diagnosis code classification is a common method for cohort identification in cirrhosis research, but it is often inaccurate and augmented by labor-intensive chart review. Natural language processing (NLP) using large language models (LLMs) is a potentially more accurate method. To assess LLMs' potential for cirrhosis cohort identification, we compared code-based versus LLM-based classification with chart review as a "gold standard." METHODS: We extracted and conducted a limited chart review of 3,788 discharge summaries of cirrhosis admissions. We engineered zero-shot prompts using Generative Pre-trained Transformer (GPT)-4 to determine whether cirrhosis and its complications were active hospitalization problems. We calculated positive predictive values (PPVs) of LLM-based classification versus limited chart review, and PPVs of code-based versus LLM-based classification as a "silver standard" in all 3,788 summaries. RESULTS: Versus gold standard chart review, code-based classification achieved PPVs of 82.2% for identifying cirrhosis, 41.7% hepatic encephalopathy, 72.8% ascites, 59.8% gastrointestinal bleeding, and 48.8% spontaneous bacterial peritonitis. Compared to chart review, GPT-4 achieved 87.8-98.8% accuracies for identifying cirrhosis and its complications. Using LLM as a silver standard, code-based classification achieved PPVs of 79.8% for identifying cirrhosis, 53.9% hepatic encephalopathy, 55.3% ascites, 67.6% gastrointestinal bleeding, and 65.5% spontaneous bacterial peritonitis. CONCLUSIONS: LLM-based classification was highly accurate versus manual chart review in identifying cirrhosis and its complications - this allowed us to assess the performance of code-based classification at scale using LLMs as a silver standard. These results suggest LLMs could augment or replace code-based cohort classification and raise questions regarding the necessity of chart review.

Common definitions and variables are needed for the United States to join the conversation on acute-on-chronic liver failure.

Acute-on-chronic liver failure (ACLF) is a variably defined syndrome characterized by acute decompensation of cirrhosis with organ failures. At least 13 different definitions and diagnostic criteria for ACLF have been proposed, and there is increasing recognition that patients with ACLF may face disadvantages in the current United States liver allocation system. There is a need, therefore, for more standardized data collection and consensus to improve study design and outcome assessment in ACLF. In this article, we discuss the current landscape of transplantation for patients with ACLF, strategies to optimize organ utility, and data opportunities based on emerging technologies to facilitate improved data collection.

Decreasing Case Fatality Rates for Patients With Cirrhosis Infected With SARS-CoV-2: A National COVID Cohort Collaborative Study.

BACKGROUND & AIMS: The virulence and severity of SARS-CoV-2 infections have decreased over time in the general population due to vaccinations and improved antiviral treatments. Whether a similar trend has occurred in patients with cirrhosis is unclear. We used the National COVID Cohort Collaborative (N3C) to describe the outcomes over time. METHODS: We utilized the N3C level 3 data set with uncensored dates to identify all patients with chronic liver disease (CLD) with and without cirrhosis who had SARS-CoV-2 infection as of November 2023. We described the observed 30-day case fatality rate (CFR) by month of infection. We used adjusted survival analyses to calculate relative hazard of death by month of infection compared with infection at the onset of the COVID-19 pandemic. RESULTS: We identified 117,811 total patients with CLD infected with SARS-CoV-2 between March 2020 and November 2023: 27,428 (23%) with cirrhosis and 90,383 (77%) without cirrhosis. The observed 30-day CFRs during the entire study period were 1.1% (1016) for patients with CLD without cirrhosis and 6.3% (1732) with cirrhosis. Observed 30-day CFRs by month of infection varied throughout the pandemic and showed a sustained downward trend since 2022. Compared with infection in Quarter 2 of 2020 (at the beginning of the pandemic), the adjusted hazards of death at 30 days for infection in Quarter 3 of 2023 were 0.20 (95% confidence interval [CI], 0.08-0.50) for patients with CLD without cirrhosis and 0.35 (95% CI, 0.18-0.69) for patients with CLD with cirrhosis. CONCLUSIONS: In this N3C study, we found that the observed 30-day CFR decreased progressively for patients with CLD both with and without cirrhosis, consistent with broader trends seen in the general population.

Outpatient mean arterial pressure: A potentially modifiable risk for acute kidney injury and death among patients with cirrhosis.

Mean arterial blood pressure (MAP), which decreases as portal hypertension progresses, may be a modifiable risk factor among patients with cirrhosis. We included adults enrolled in the Functional Assessment in Liver Transplantation study. We completed latent class trajectory analyses to define MAP trajectories. We completed time-dependent Cox-regression analyses to test the association between outpatient MAP and 3 cirrhosis-related outcomes: (1) stage 2 acute kidney injury (AKI), defined as a ≥200% increase in serum creatinine from baseline; (2) a 5-point increase in the MELD-Na score, defined as the incidence of increase from initial MELD-Na; (3) waitlist mortality, defined as death on the waitlist. For each outcome, we defined MAP cut points by determining the maximally selected Log-rank statistic after univariable Cox-regression analyses. Among the 1786 patients included in this analysis, our latent class trajectory analyses identified 3 specific outpatient MAP trajectories: "stable-low," "stable-high," and "increasing-to-decreasing." However, >80% of patients were in a "stable-low" trajectory. We found in adjusted analyses that outpatient MAP was associated with each of our outcomes: Stage 2 AKI (adjusted hazard ratio 0.88 per 10 mm Hg increase in MAP [95% CI: 0.79-0.99]); 5-point increase in MELD-Na (adjusted hazard ratio: 0.91 [95% CI: 0.86-0.96]; waitlist mortality (adjusted hazard ratio: 0.89 [95% CI: 0.81-0.96]). For each outcome, we found that an outpatient MAP of 82 mm Hg was most associated with outcomes ( p <0.05 for all). Our study informs the association between outpatient MAP and cirrhosis-related outcomes. These findings, coupled with the identification of specific thresholds, lay the foundation for the trial of targeted outpatient MAP modulation in patients with cirrhosis.

Breakthrough SARS-CoV-2 infection outcomes in vaccinated patients with chronic liver disease and cirrhosis: A National COVID Cohort Collaborative study.

BACKGROUND AND AIMS: Outcomes of breakthrough SARS-CoV-2 infections have not been well characterized in non-veteran vaccinated patients with chronic liver diseases (CLD). We used the National COVID Cohort Collaborative (N3C) to describe these outcomes. APPROACH AND RESULTS: We identified all CLD patients with or without cirrhosis who had SARS-CoV-2 testing in the N3C Data Enclave as of January 15, 2022. We used Poisson regression to estimate incidence rates of breakthrough infections and Cox survival analyses to associate vaccination status with all-cause mortality at 30 days among infected CLD patients. We isolated 278,457 total CLD patients: 43,079 (15%) vaccinated and 235,378 (85%) unvaccinated. Of 43,079 vaccinated patients, 32,838 (76%) were without cirrhosis and 10,441 (24%) with cirrhosis. Breakthrough infection incidences were 5.4 and 4.9 per 1000 person-months for fully vaccinated CLD patients without cirrhosis and with cirrhosis, respectively. Of the 68,048 unvaccinated and 10,441 vaccinated CLD patients with cirrhosis, 15% and 3.7%, respectively, developed SARS-CoV-2 infection. The 30-day outcome of mechanical ventilation or death after SARS-CoV-2 infection for unvaccinated and vaccinated CLD patients with cirrhosis were 15.2% and 7.7%, respectively. Compared to unvaccinated patients with cirrhosis, full vaccination was associated with a 0.34-times adjusted hazard of death at 30 days. CONCLUSIONS: In this N3C study, breakthrough infection rates were similar among CLD patients with and without cirrhosis. Full vaccination was associated with a 66% reduction in risk of all-cause mortality for breakthrough infection among CLD patients with cirrhosis. These results provide an additional impetus for increasing vaccination uptake in CLD populations.

Clinical decision support and electronic interventions to improve care quality in chronic liver diseases and cirrhosis.

Significant quality gaps exist in the management of chronic liver diseases and cirrhosis. Clinical decision support systems-information-driven tools based in and launched from the electronic health record-are attractive and potentially scalable prospective interventions that could help standardize clinical care in hepatology. Yet, clinical decision support systems have had a mixed record in clinical medicine due to issues with interoperability and compatibility with clinical workflows. In this review, we discuss the conceptual origins of clinical decision support systems, existing applications in liver diseases, issues and challenges with implementation, and emerging strategies to improve their integration in hepatology care.

Association between neighborhood-based material deprivation and liver transplant waitlist registrants demographics and mortality.

BACKGROUND & AIMS: Liver transplantation for alcohol-related liver disease (ARLD) has increased. We examined temporal trends in ARLD listing practices by neighborhood deprivation and evaluated the impact of neighborhood deprivation on waitlist mortality. METHODS: We included all adults > 18 years listed 2008-2019 in the UNOS registry. Our primary exposure was the neighborhood socioeconomic deprivation index based on patients' listing zip codes. We determined temporal trends in an ARLD listing diagnosis. We modeled ARLD listing diagnosis using logistic regression and waitlist mortality using Cox proportional hazards models. RESULTS: The waitlist contained an increasing proportion of patients listed with ARLD over the study period; however, this rate increased the least for patients from the most deprived tertile (p < .001). Patients from the most deprived tertile were the least likely to be listed with ARLD (OR: .97, 95CI: .95-.98). In our adjusted model, patients from the most deprived tertile had an increased hazard of waitlist mortality (OR: 1.10, 95CI: 1.06-1.14). CONCLUSION: Neighborhood deprivation was associated with a decreased likelihood of being listed with ARLD, suggesting that transplant for ARLD is inequitably available. The increased mortality associated with neighborhood deprivation demands future work to uncover the underlying reasons for this disparity.

Synthesis of N-Aryl-4-trifluoromethylthiazol-2-amines via Insertion/Annulation of Trifluoromethylimidoyl Sulfoxonium Ylides with Sodium Thiocyanate.

An efficient p-TsOH-mediated insertion of sodium thiocyanate into trifluoromethylimidoyl sulfoxonium ylides has been reported, affording annulated N-aryl-4-trifluoromethylthiazol-2-amines in 42-84% yields in a one-pot manner. This protocol encompasses a variety of trifluoromethylimidoyl sulfoxonium ylides with thiocyanate serving as the source of the "S-C═N" moiety of the thiazole ring. The versatile transformations of the resulting pharmacologically important N-aryl-4-trifluoromethylthiazol-2-amines were also demonstrated.

Clinical Characteristics Associated With Posttransplant Survival Among Adults 70 Years Old or Older Undergoing Liver Transplantation.

GOALS: We sought to identify pre-liver transplantation (LT) characteristics among older adults associated with post-LT survival. BACKGROUND: The proportion of older patients undergoing deceased-donor liver transplantation (DDLT) has increased over time. STUDY: We analyzed adult DDLT recipients in the United Network for Organ Sharing registry from 2016 through 2020, excluding patients listed as status 1 or with a model of end-stage liver disease exceptions for hepatocellular carcinoma. Kaplan-Meier methods were used to estimate post-LT survival probabilities among older recipients (age ≥70 y). Associations between clinical covariates and post-LT mortality were assessed using Cox regressions. RESULTS: Of 22,862 DDLT recipients, 897 (4%) were 70 years old or older. Compared with younger recipients, older recipients had worse overall survival ( P < 0.01) (1 y: 88% vs 92%, 3 y: 77% vs 86%, and 5 y: 67% vs 78%). Among older adults, in univariate Cox regressions, dialysis [hazards ratio (HR): 1.96, 95% CI: 1.38-2.77] and poor functional status [defined as Karnofsky Performance Score (KPS) <40] (HR: 1.82, 95% CI: 1.31-2.53) were each associated with mortality, remaining significant on multivariable Cox regressions. The effect of dialysis and KPS <40 at LT on post-LT survival (HR: 2.67, 95% CI: 1.77-4.01) was worse than the effects of either KPS <40 (HR: 1.52, 95% CI: 1.03-2.23) or dialysis alone (HR: 1.44, 95% CI: 0.62-3.36). Older recipients with KPS >40 without dialysis had comparable survival rates compared with younger recipients ( P = 0.30). CONCLUSIONS: While older DDLT recipients had worse overall post-LT survival compared with younger recipients, favorable survival rates were observed among older adults who did not require dialysis and had poor functional status. Poor functional status and dialysis at LT may be useful to stratify older adults at higher risk for poor post-LT outcomes.

Recent advances in the synthesis of trifluoromethyl-containing heterocyclic compounds via trifluoromethyl building blocks.

Trifluoromethylated heterocyclic compounds have played an increasingly significant role in pharmaceuticals, agrochemicals, and materials. This is because the introduction of trifluoromethyl could enhance the lipophilicity, metabolic stability, and pharmacokinetic properties of heterocyclic drug molecules. Therefore, the synthesis of trifluoromethylated heterocyclics has become a major subject of research. The construction of trifluoromethylated heterocyclics via the annulation of trifluoromethyl building blocks with suitable partners has been proved to be a powerful strategy. In this review, we systematically summarize and discuss recent advances in the preparation of trifluoromethyl-containing heterocyclics via trifluoromethyl building block strategies over the period from 2019 to the present.

Risk factors for severe outcomes of coronavirus disease 2019 through the waves of the pandemic: Comparing patients with and without solid organ transplantation.

BACKGROUND: While coronavirus disease 2019 (COVID-19) is no longer a public health emergency, certain patients remain at risk of severe outcomes. To better understand changing risk profiles, we studied the risk factors for patients with and without solid organ transplantation (SOT) through the various waves of the pandemic. METHODS: Using the National COVID Cohort Collaborative we studied a cohort of adult patients testing positive for COVID-19 between January 1, 2020, and May 2, 2022. We separated the data into waves of COVID-19 as defined by the Centers for Disease Control. In our primary outcome, we used multivariable survival analysis to look at various risk factors for hospitalization in those with and without SOT. RESULTS: A total of 3,570,032 patients were captured. We found an overall risk attenuation of adverse COVID-19-associated outcomes over time. In both non-SOT and SOT populations, diabetes, chronic kidney disease, and congestive heart failure were risk factors for hospitalization. For SOT specifically, longer time periods between transplant and COVID-19 were protective and age was a risk factor. Notably, asthma was not a risk factor for major adverse renal cardiovascular events, hospitalization, or mortality in either group. CONCLUSIONS: Our study provides a longitudinal view of the risks associated with adverse COVID-related outcomes amongst SOT and non-SOT patients, and how these risk factors evolved over time. Our work will help inform providers and policymakers to better target high-risk patients.

Pharmacokinetics and tissue distribution of vigabatrin enantiomers in rats.

Purpose: To investigate the pharmacokinetics and tissue distribution of VGB racemate and its single enantiomers, and explore the potential of clinic development for single enantiomer S-VGB. Methods: In the pharmacokinetics study, male Sprague-Dawley rats were gavaged with VGB racemate or its single enantiomers dosing 50, 100 or 200 mg/kg, and the blood samples were collected during 12 h at regular intervals. In the experiment of tissue distribution, VGB and its single enantiomers were administered intravenously dosing 200 mg/kg, and the tissues including heart, liver, spleen, lung and kidney, eyes, hippocampus, and prefrontal cortex were separated at different times. The concentrations of R-VGB and S-VGB in the plasma and tissues were measured using HPLC. Results: Both S-VGB and R-VGB could be detected in the plasma of rats administered with VGB racemate, reaching Cmax at approximately 0.5 h with t1/2 2-3 h. There was no significant pharmacokinetic difference between the two enantiomers when VGB racemate was given 200 mg/kg and 100 mg/kg. However, when given at the dose of 50 mg/kg, S-VGB presented a shorter t1/2 and a higher Cl/F than R-VGB, indicating a faster metabolism of S-VGB. Furthermore, when single enantiomer was administered respectively, S-VGB presented a slower metabolism than R-VGB, as indicated by a longer t1/2 and MRT but a lower Cmax. Moreover, compared with the VGB racemate, the single enantiomers S-VGB and R-VGB had shorter t1/2 and MRT, higher Cmax and AUC/D, and lower Vz/F and Cl/F, indicating the stronger oral absorption and faster metabolism of single enantiomer. In addition, regardless of VGB racemate administration or single enantiomer administration, S-VGB and R-VGB had similar characteristics in tissue distribution, and the content of S-VGB in hippocampus, prefrontal cortex and liver was much higher than that of R-VGB. Conclusions: Although there is no transformation between S-VGB and R-VGB in vivo, those two enantiomers display certain disparities in the pharmacokinetics and tissue distribution, and interact with each other. These findings might be a possible interpretation for the pharmacological and toxic effects of VGB and a potential direction for the development and optimization of the single enantiomer S-VGB.

[Effect of Naotaifang on microglial polarization and glial scar following cerebral ischemia reperfusion injury].

This study aims to investigate the effect of Naotaifang(NTF) on the proteins associated with microglial polarization and glial scar in the rat model of cerebral ischemia reperfusion injury(CIRI). The CIRI model was established by middle cerebral artery occlusion/reperfusion. The 48 successfully modeled rats were randomized into model 7 d, model 14 d, NTF 7 d, and NTF 14 d groups(n=12). In addition, 12 SD rats were selected as the sham group. The NTF group was administrated with NTF suspension at 27 g·kg~(-1)·d~(-1) by gavage, and the sham, model 7 d, and model 14 d groups were administrated with the same volume of normal saline every day by gavage for 7 and 14 days, respectively. After the intervention, Longa score was evaluated. The infarct volume was measured by 2,3,5-triphenyl-2H-tetrazolium chloride(TTC) staining. Morris water maze and open field tests were carried out to evaluate the spatial learning, memory, cognitive function, and anxiety degree of rats. Hematoxylin-eosin(HE) staining was employed to observe the morphological structure and damage of the brain tissue. The immunofluorescence assay was employed to measure the expression of glial fibrillary acidic protein(GFAP) and glial scar. Western blot was employed to determine the protein levels of GFAP, neurocan, phosphacan, CD206, arginase-1(Arg-1), interleukin(IL)-1ß, IL-6, and IL-4. Compared with the sham, model 7 d and model 14 d groups showed cerebral infarction of different degrees, severe pathological injury of cerebral cortex and hippocampus, neurological impairment, reduced spatial learning and memory, cognitive dysfunction, severe anxiety, astrocyte hyperplasia, thickening penumbra glial scar, and up-regulated protein levels of IL-1ß, IL-6, GFAP, neurocan, phosphacan, CD206, and Arg-1(P<0.01). Compared with the model group, NTF 7 d and NTF 14 d groups improved spatial learning, memory, and cognitive function, reduced anxiety, improved nerve function, reduced cerebral infarction volume, reduced astrocyte hyperplasia, thinned penumbra glial scar, down-regulated the protein levels of GFAP, neurocan, phosphacan, IL-6, and IL-1ß, and up-regulated the protein levels of IL-4, CD206, and Arg-1(P<0.05 or P<0.01). NTF exerts a neuroprotective effect on CIRI by inducing the M2 polarization of microglia, inhibiting inflammatory response, and reducing the formation of glial scar.

Solvent-Controlled Enantiodivergent Construction of P(V)-Stereogenic Molecules via Palladium-Catalyzed Annulation of Prochiral N-Aryl Phosphonamides with Aromatic Iodides.

In this work, we describe an efficient and modular method for enantiodivergent accessing P(V)-stereogenic molecules by utilizing the catalytic atroposelective Catellani-type C-H arylation/desymmetric intramolecular N-arylation cascade reaction. The enantioselectivity of this protocol was proved to be tuned by the polarity of the solvent, thus providing a wide range of both chiral P(V)-stereogenic enantiomers in moderate to good yields with good to excellent enantiomeric excesses. Noteworthy is that the strategy developed herein represents an unprecedented example of solvent-dictated inversion of the enantioselectivity of P(V)-stereogenic compounds.

Predicting post-liver transplant outcomes in patients with acute-on-chronic liver failure using Expert-Augmented Machine Learning.

Liver transplantation (LT) is a treatment for acute-on-chronic liver failure (ACLF), but high post-LT mortality has been reported. Existing post-LT models in ACLF have been limited. We developed an Expert-Augmented Machine Learning (EAML) model to predict post-LT outcomes. We identified ACLF patients who underwent LT in the University of California Health Data Warehouse. We applied the RuleFit machine learning (ML) algorithm to extract rules from decision trees and create intermediate models. We asked human experts to rate the rules generated by RuleFit and incorporated these ratings to generate final EAML models. We identified 1384 ACLF patients. For death at 1 year, areas under the receiver-operating characteristic curve were 0.707 (confidence interval [CI] 0.625-0.793) for EAML and 0.719 (CI 0.640-0.800) for RuleFit. For death at 90 days, areas under the receiver-operating characteristic curve were 0.678 (CI 0.581-0.776) for EAML and 0.707 (CI 0.615-0.800) for RuleFit. In pairwise comparisons, both EAML and RuleFit models outperformed cross-sectional models. Significant discrepancies between experts and ML occurred in rankings of biomarkers used in clinical practice. EAML may serve as a method for ML-guided hypothesis generation in further ACLF research.

Associations between COVID-19 therapies and inpatient gastrointestinal bleeding: A multisite retrospective study.

Little data is available regarding the incidence of gastrointestinal bleeding in adults hospitalized with COVID-19 infection and the influence of patient comorbidities and demographics, COVID-19 therapies, and typical medications used. In this retrospective study, we utilized the National COVID Cohort Collaborative to investigate the primary outcome of the development of gastrointestinal bleeding in 512 467 hospitalized US adults (age >18 years) within 14 days of a COVID-19 infection and the influence of demographics, comorbidities, and selected medications. Gastrointestinal bleeding developed in 0.44% of patients hospitalized with COVID-19. Comorbidities associated with gastrointestinal bleeding include peptic ulcer disease (adjusted odds ratio [aOR] 10.2), obesity (aOR 1.27), chronic kidney disease (aOR 1.20), and tobacco use disorder (aOR 1.28). Lower risk of gastrointestinal bleeding was seen among women (aOR 0.76), Latinx (aOR 0.85), and vaccinated patients (aOR 0.74). Dexamethasone alone or with remdesivir was associated with lower risk of gastrointestinal bleeding (aOR 0.69 and aOR 0.83, respectively). Remdesivir monotherapy was associated with upper gastrointestinal bleeding (aOR 1.25). Proton pump inhibitors were more often prescribed in patients with gastrointestinal bleeding, likely representing treatment for gastrointestinal bleeding rather than a risk factor for its development. In adult patients hospitalized with COVID-19, the use of dexamethasone alone or in combination with remdesivir is negatively associated with gastrointestinal bleeding. Remdesivir monotherapy is associated with increased risk of upper gastrointestinal bleeding.

Racial/ethnic disparities in wait-list outcomes are only partly explained by socioeconomic deprivation among children awaiting liver transplantation.

BACKGROUND AND AIMS: Racial/ethnic minority children have worse liver transplant (LT) outcomes. We evaluated whether neighborhood socioeconomic deprivation affected associations between race/ethnicity and wait-list mortality. APPROACH AND RESULTS: We included children (age <18) listed 2005-2015 in the Scientific Registry of Transplant Recipients. We categorized patients as non-Hispanic White, Black, Hispanic, and other. We matched patient ZIP codes to a neighborhood socioeconomic deprivation index (range, 0-1; higher values indicate worse deprivation). Primary outcomes were wait-list mortality, defined as death/delisting for too sick, and receipt of living donor liver transplant (LDLT). Competing risk analyses modeled the association between race/ethnicity and wait-list mortality, with deceased donor liver transplant (DDLT) and LDLT as competing risks, and race/ethnicity and LDLT, with wait-list mortality and DDLT as competing risks. Of 7716 children, 17% and 24% identified as Black and Hispanic, respectively. Compared to White children, Black and Hispanic children had increased unadjusted hazard of wait-list mortality (subhazard ratio [sHR], 1.44; 95% CI, 1.18, 1.75 and sHR, 1.48; 95% CI, 1.25, 1.76, respectively). After adjusting for neighborhood deprivation, insurance, and listing laboratory Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease, Black and Hispanic children did not have increased hazard of wait-list mortality (sHR, 1.12; 95% CI, 0.91, 1.39 and sHR, 1.21; 95% CI, 1.00, 1.47, respectively). Similarly, Black and Hispanic children had a decreased likelihood of LDLT (sHR, 0.58; 95% CI, 0.45, 0.75 and sHR, 0.61; 95% CI, 0.49, 0.75, respectively). Adjustment attenuated the effect of Black and Hispanic race/ethnicity on likelihood of LDLT (sHR, 0.79; 95% CI, 0.60, 1.02 and sHR, 0.89; 95% CI, 0.70, 1.11, respectively). CONCLUSIONS: Household and neighborhood socioeconomic factors and disease severity at wait-list entry help explain racial/ethnic disparities for children awaiting transplant. A nuanced understanding of how social adversity contributes to wait-list outcomes may inform strategies to improve outcomes.