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The growing complexities of clinical medicine and biomedical research have clouded the career path for physician-scientists. In this perspective piece, we address one of the most opaque career stage transitions along the physician-scientist career path, the transition from medical school to research-focused internal medicine residency programs, or physician-scientist training programs (PSTPs). We present the perspectives of medical scientist training program (MSTP) and PSTP directors on critical features of PSTPs that can help trainees proactively align their clinical and scientific training for successful career development. We aim to provide both trainees and MSTP directors with a conceptual framework to better understand and navigate PSTPs. We also offer interview-specific questions to help trainees gather data and make informed decisions in choosing a residency program that best supports their career.

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of liver diseases in the United States and can progress to cirrhosis, end-stage liver disease and need for liver transplantation. There are limited therapies for NAFLD, in part, due to incomplete understanding of the disease pathogenesis, which involves different cell populations in the liver. Endoplasmic reticulum stress and its adaptative unfolded protein response (UPR) signaling pathway have been implicated in the progression from simple hepatic steatosis to nonalcoholic steatohepatitis (NASH). We have previously shown that mice lacking the UPR protein X-box binding protein 1 (XBP1) in the liver demonstrated enhanced liver injury and fibrosis in a high fat sugar (HFS) dietary model of NAFLD. In this study, to better understand the role of liver XBP1 in the pathobiology of NAFLD, we fed hepatocyte XBP1 deficient mice a HFS diet or chow and investigated UPR and other cell signaling pathways in hepatocytes, hepatic stellate cells and immune cells. We demonstrate that loss of XBP1 in hepatocytes increased inflammatory pathway expression and altered expression of the UPR signaling in hepatocytes and was associated with enhanced hepatic stellate cell activation after HFS feeding. We believe that a better understanding of liver cell-specific signaling in the pathogenesis of NASH may allow us to identify new therapeutic targets.

Background and aimsWe hypothesized that a drug's clinical signature (or phenotype) of liver injury can be assessed and used to quantitatively develop a computer-assisted DILI causality assessment-tool (DILI-CAT). Therefore, we evaluated drug-specific DILI-phenotypes for amoxicillin-clavulanate (AMX/CLA), cefazolin, cyproterone, and Polygonum multiflorum using data from published case series, to develop DILI-CAT scores for each drug.MethodsDrug specific phenotypes were made up of the following three clinical features: (1) latency, (2) R-value, and (3) AST/ALT ratio. A point allocation system was developed with points allocated depending on the variance from the norm (or "core") for the 3 variables in published datasets.ResultsThe four drugs had significantly different phenotypes based on latency, R-value, and AST/ALT ratio. The median cyproterone latency was 150 days versus < 43 days for the other three drugs (median: 26 for AMX/CLA, 20 for cefazolin, and 20 for Polygonum multiflorum; pConclusionsDILI-CAT is a data-driven, diagnostic tool built to define drug-specific phenotypes for DILI adjudication. The data provide proof of principle that a drug-specific, data-driven causality assessment tool can be developed for different drugs and raise the possibility that such a process could enhance causality assessment methods.

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease such as simple steatosis, nonalcoholic steatohepatitis (NASH), cirrhosis and fibrosis. However, the molecular pathogenesis and genetic variations causing NAFLD are poorly understood. The high prevalence and incidence of NAFLD suggests that genetic variations on a large number of genes might be involved in NAFLD. To identify genetic variants causing inherited liver disease, we used zebrafish as a model system for a large-scale mutant screen, and adopted a whole genome sequencing approach for rapid identification of mutated genes found in our screen. Here, we report on a forward genetic screen of ENU mutagenized zebrafish. From 250 F2 lines of ENU mutagenized zebrafish during post-developmental stages (5 to 8 days post fertilization), we identified 19 unique mutant zebrafish lines displaying visual evidence of hepatomegaly and/or steatosis with no developmental defects. Histological analysis of mutants revealed several specific phenotypes, including common steatosis, micro/macrovesicular steatosis, hepatomegaly, ballooning, and acute hepatocellular necrosis. This work has identified multiple post-developmental mutants and establishes zebrafish as a novel animal model for post-developmental inherited liver disease.

Smooth muscle α actin (Acta2) expression is largely restricted to smooth muscle cells, pericytes and specialized fibroblasts, known as myofibroblasts. Liver injury, associated with cirrhosis, induces transformation of resident hepatic stellate cells into liver specific myofibroblasts, also known as activated cells. Here, we have used in vitro and in vivo wound healing models to explore the functional role of Acta2 in this transformation. Acta2 was abundant in activated cells isolated from injured livers but was undetectable in quiescent cells isolated from normal livers. Both cellular motility and contraction were dramatically increased in injured liver cells, paralleled by an increase in Acta2 expression, when compared with quiescent cells. Inhibition of Acta2 using several different techniques had no effect on cytoplasmic actin isoform expression, but led to reduced cellular motility and contraction. Additionally, Acta2 knockdown was associated with a significant reduction in Erk1/2 phosphorylation compared to control cells. The data indicate that Acta2 is important specifically in myofibroblast cell motility and contraction and raise the possibility that the Acta2 cytoskeleton, beyond its structural importance in the cell, could be important in regulating signaling processes during wound healing in vivo.

Background: The aim of this study was to investigate the impact of blood transfusion (BT) on mortality and rebleeding in patients with gastrointestinal bleeding (GIB) and whether BT at a threshold of ≤7 g/dL may improve these outcomes., Methods: A prospective study was conducted in patients admitted with GIB between 2013 and 2021. Antithrombotic (AT) use and clinical outcomes were compared between transfused and non-transfused patients, and between those transfused at a threshold of ≤7 vs. >7 g/dL. Multivariate analysis was performed to identify predictors of mortality and rebleeding., Results: A total of 667 patients, including 383 transfused, were followed up for a median of 56 months. Predictors of end-of-follow-up mortality included: age-adjusted Charlson Comorbidity Index, stigmata of recent hemorrhage (SRH), and being on anticoagulants only upon presentation (P=0.026). SRH was a predictor of end-of-follow-up rebleeding, while having been on only antiplatelet therapy (AP) upon presentation was protective (P<0.001). BT was not associated with mortality or rebleeding at 1 month or end of follow up. Among transfused patients, being discharged only on AP protected against mortality (P=0.044). BT at >7 g/dL did not affect the risk of short or long-term rebleeding or mortality compared to BT at ≤7 g/dL., Conclusions: Short- and long-term mortality and rebleeding in GIB were not affected by BT, nor by a transfusion threshold of ≤7 vs. >7 g/dL, but were affected by the use of AT. Further studies that account for AT use are needed to determine the best transfusion strategy in GIB., Competing Interests: Conflict of Interest: None, (Copyright: © Hellenic Society of Gastroenterology.)

Significant amounts of medical waste are generated in endoscopy units. Improper disposal has significant health, cost, and environmental implications. The aim of this study was to better understand the appropriateness of handling of medical waste in the endoscopy unit. This is a validated survey completed online and in person by endoscopy staff and gastroenterologists. Main outcome measurements include the method of disposal of endoscopic accessories (snares, dilating balloons, endoscopic retrograde cholangiopancreatography wires, and sphincterotomes) and nasogastric tubes and whether or not in the appropriate disposal bin (i.e., in sharps container, red bags, or regular trash). The appropriateness of the method of disposal was determined per Occupational Safety and Health Administration guidelines. Respondents included 783 endoscopy staff members and 352 gastroenterologists. Fifty-eight percent of endoscopy staff members and 65% of gastroenterologists handled simple endoscopic accessories as regulated medical waste instead of regular trash. Furthermore, 27% of respondents discarded endoscopic accessories as sharps, although they are not considered sharps. Nearly one third of respondents discarded nasogastric tubes and other endoscopic accessories differently, even though both would have same degree of contamination. Only 7 respondents (0.6%) understood disposal costs. All but 23 respondents (2%) felt that medical personnel should be better informed about medical waste. Most medical waste from endoscopy laboratories is handled inappropriately. Endoscopy staff and gastroenterologists' understanding of recommended disposal methods for endoscopic accessories is poor. The data have major financial and environmental implications.