Characterizing the extent and morphology of intraductal mucinous biliary neoplasm using a novel cholangioscope and treatment with ampullectomy.

Video 1A case characterizing the extent and morphology of an intraductal mucinous biliary neoplasm using a novel cholangioscope and treatment with ampullectomy.

Advanced endoscopic imaging for detection of Barrett's esophagus.

Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC), and is caused by chronic gastroesophageal reflux. BE can progress over time from metaplasia to dysplasia, and eventually to EAC. EAC is associated with a poor prognosis, often due to advanced disease at the time of diagnosis. However, if BE is diagnosed early, pharmacologic and endoscopic treatments can prevent progression to EAC. The current standard of care for BE surveillance utilizes the Seattle protocol. Unfortunately, a sizable proportion of early EAC and BE-related high-grade dysplasia (HGD) are missed due to poor adherence to the Seattle protocol and sampling errors. New modalities using artificial intelligence (AI) have been proposed to improve the detection of early EAC and BE-related HGD. This review will focus on AI technology and its application to various endoscopic modalities such as high-definition white light endoscopy, narrow-band imaging, and volumetric laser endomicroscopy.

Serum metabolomic analysis in cirrhotic alcohol-associated liver disease patients identified differentially altered microbial metabolites and novel potential biomarkers for disease severity.

BACKGROUND: Alcohol-Associated Liver Disease (ALD) is a leading cause of liver mortality. Mechanisms responsible for severe ALD and the roles of gut microbiota are not fully understood. Multi-omics tools have enabled a better understanding of metabolic alterations and can aid in identifying metabolites as biomarkers for severe ALD. AIMS: Examine differences between cirrhotic and non-cirrhotic ALD, investigate microbial contributions to such changes, and identify potential diagnostic and prognostic metabolites for severe ALD. METHODS: Untargeted metabolomics were performed on the serum of 11 non-cirrhotic and 11 cirrhotic ALD patients. Data were analyzed using MetOrigin and Metaboanalyst to identify enriched pathways. RESULTS: Increased methylated nucleotides, gamma-glutamyl amino acids, bile acids, and specific metabolites kynurenine and campesterol were increased in ALD cirrhosis, whereas branched-chain amino acids, serotonin, and xanthurenate were decreased. Microbial contributions included increases in the short-chain fatty acid indolebutyrate and methionine sulfoxide in ALD cirrhosis. The analysis also identified the potential for serum levels of 3-ureidopropionate, cis-3,3-methyleneheptanoylglycine, retinol, and valine to be used as biomarkers for clinical assessment of alcohol-associated cirrhosis. CONCLUSION: We have identified a set of metabolites that are differentially altered in cirrhotic compared to non-cirrhotic ALD that can potentially be used as biomarkers for the severity of the disease.

Siglec-9 Restrains Antibody-Dependent Natural Killer Cell Cytotoxicity against SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection alters the immunological profiles of natural killer (NK) cells. However, whether NK antiviral functions are impaired during severe coronavirus disease 2019 (COVID-19) and what host factors modulate these functions remain unclear. We found that NK cells from hospitalized COVID-19 patients degranulate less against SARS-CoV-2 antigen-expressing cells (in direct cytolytic and antibody-dependent cell cytotoxicity [ADCC] assays) than NK cells from mild COVID-19 patients or negative controls. The lower NK degranulation was associated with higher plasma levels of SARS-CoV-2 nucleocapsid antigen. Phenotypic and functional analyses showed that NK cells expressing the glyco-immune checkpoint Siglec-9 elicited higher ADCC than Siglec-9- NK cells. Consistently, Siglec-9+ NK cells exhibit an activated and mature phenotype with higher expression of CD16 (FcγRIII; mediator of ADCC), CD57 (maturation marker), and NKG2C (activating receptor), along with lower expression of the inhibitory receptor NKG2A, than Siglec-9- CD56dim NK cells. These data are consistent with the concept that the NK cell subpopulation expressing Siglec-9 is highly activated and cytotoxic. However, the Siglec-9 molecule itself is an inhibitory receptor that restrains NK cytotoxicity during cancer and other viral infections. Indeed, blocking Siglec-9 significantly enhanced the ADCC-mediated NK degranulation and lysis of SARS-CoV-2-antigen-positive target cells. These data support a model in which the Siglec-9+ CD56dim NK subpopulation is cytotoxic even while it is restrained by the inhibitory effects of Siglec-9. Alleviating the Siglec-9-mediated restriction on NK cytotoxicity may further improve NK immune surveillance and presents an opportunity to develop novel immunotherapeutic tools against SARS-CoV-2 infected cells. IMPORTANCE One mechanism that cancer cells use to evade natural killer cell immune surveillance is by expressing high levels of sialoglycans, which bind to Siglec-9, a glyco-immune checkpoint molecule on NK cells. This binding inhibits NK cell cytotoxicity. Several viruses, such as hepatitis B virus (HBV) and HIV, also use a similar mechanism to evade NK surveillance. We found that NK cells from SARS-CoV-2-hospitalized patients are less able to function against cells expressing SARS-CoV-2 Spike protein than NK cells from SARS-CoV-2 mild patients or uninfected controls. We also found that the cytotoxicity of the Siglec-9+ NK subpopulation is indeed restrained by the inhibitory nature of the Siglec-9 molecule and that blocking Siglec-9 can enhance the ability of NK cells to target cells expressing SARS-CoV-2 antigens. Our results suggest that a targetable glyco-immune checkpoint mechanism, Siglec-9/sialoglycan interaction, may contribute to the ability of SARS-CoV-2 to evade NK immune surveillance.

Markers of fungal translocation are elevated during post-acute sequelae of SARS-CoV-2 and induce NF-κB signaling.

Long COVID, a type of post-acute sequelae of SARS-CoV-2 (PASC), has been associated with sustained elevated levels of immune activation and inflammation. However, the mechanisms that drive this inflammation remain unknown. Inflammation during acute coronavirus disease 2019 could be exacerbated by microbial translocation (from the gut and/or lung) to blood. Whether microbial translocation contributes to inflammation during PASC is unknown. We did not observe a significant elevation in plasma markers of bacterial translocation during PASC. However, we observed higher levels of fungal translocation - measured as ß-glucan, a fungal cell wall polysaccharide - in the plasma of individuals experiencing PASC compared with those without PASC or SARS-CoV-2-negative controls. The higher ß-glucan correlated with higher inflammation and elevated levels of host metabolites involved in activating N-methyl-d-aspartate receptors (such as metabolites within the tryptophan catabolism pathway) with established neurotoxic properties. Mechanistically, ß-glucan can directly induce inflammation by binding to myeloid cells (via Dectin-1) and activating Syk/NF-κB signaling. Using a Dectin-1/NF-κB reporter model, we found that plasma from individuals experiencing PASC induced higher NF-κB signaling compared with plasma from negative controls. This higher NF-κB signaling was abrogated by piceatannol (Syk inhibitor). These data suggest a potential targetable mechanism linking fungal translocation and inflammation during PASC.

Recently Graduated Medical Students Lack Exposure to and Comfort with Chronic Liver Diseases.

BACKGROUND: The prevalence of chronic liver disease (CLD) is rising, but it remains unclear if medical school curricula are emphasizing CLD to reflect its growing epidemiology. AIMS: To assess comfort levels and knowledge of CLD among recently graduated medical students METHODS: An anonymous survey was distributed to incoming categorical Internal Medicine (IM) interns at a single academic institution during a 2-year period. The survey consisted of 38 Likert-like questions evaluating comfort levels and self-assessed knowledge for several general medicine and liver diseases, as well as 12 multiple-choice questions to objectively test knowledge. Wilcoxon ranked sum and Fisher's exact test were then used. RESULTS: There was a 100% (n = 65) completion rate. Only 14 (22%) of those surveyed reported exposure to a hepatology rotation in medical school. Highest mean comfort levels (1 = not at all comfortable, 5 = very comfortable) were for managing congestive heart failure (3.59) and chronic obstructive pulmonary disease (3.77). Mean comfort levels for various liver diseases were significantly lower (2.22-3.03, all p < 0.01). Mean self-rated knowledge (1 = no knowledge, 5 = strong knowledge) was also low (2.14-3.13). Although 98% agreed that hepatology is critical to IM training, only 42% agreed that their hepatology education during medical school was adequate. CONCLUSIONS: Recently graduated medical students are less comfortable managing liver diseases compared to other general medical conditions. Only a minority report satisfaction with hepatology education during medical school. These findings suggest that medical curricula need to be modified to better emphasize CLD.

Corrigendum: Plasma Markers of Disrupted Gut Permeability in Severe COVID-19 Patients.

[This corrects the article DOI: 10.3389/fimmu.2021.686240.].

Mandatory Hepatology Education for Internal Medicine Residents: Long-Term Effects and Implications for Workforce Needs.

We previously created a mandatory, inpatient, hepatology resident curriculum that immediately improved comfort, knowledge, and career interest in chronic liver disease (CLD). The durability of these effects needs to be known to use this intervention to address the hepatologist shortage. Thus, we aimed to assess this curriculum's long-term outcomes on internal medicine (IM) residents' CLD comfort, knowledge, and career interest. From 2015 to 2019 at a single institution, one IM resident was always assigned to the rotation. Similar anonymous assessments were administered to incoming postgraduate year (PGY)-1 residents and graduating PGY-3 residents, including a historic control cohort that graduated in June 2015. At residency completion, the intervention cohort (n = 61) had significantly higher comfort (1, not at all comfortable/strongly disagree; 5, very comfortable/strongly agree) with both hepatology (e.g., hepatitis C, 2.5 vs. 3.3, P < 0.001) and common IM topics (e.g., heart failure, 3.6 vs. 4.8, P < 0.001) but not specialty topics lacking curricula (e.g., inflammatory bowel disease, 2.8 vs. 2.7, P = 0.54). Compared to the historic cohort (n = 27), the intervention cohort was more comfortable in several CLD topics (e.g., cirrhosis, 3.2 vs. 3.8; P = 0.005) and answered more questions correctly (65% vs. 55%; P = 0.04), but career interest was unchanged (1.9 vs. 1.8; P = 0.45). Many residents (33%) would consider a hepatology career if training were separated from gastroenterology. Conclusion: With the completion of a mandatory hepatology curriculum, residents' CLD comfort and knowledge durably improved and exceeded that of historic counterparts. Initial career interest was not sustained, perhaps due to prerequisite gastroenterology training. These findings suggest IM educational initiatives may better address hepatology workforce needs by generating comanagers than by recruiting trainees.

Plasma Markers of Disrupted Gut Permeability in Severe COVID-19 Patients.

A disruption of the crosstalk between the gut and the lung has been implicated as a driver of severity during respiratory-related diseases. Lung injury causes systemic inflammation, which disrupts gut barrier integrity, increasing the permeability to gut microbes and their products. This exacerbates inflammation, resulting in positive feedback. We aimed to test whether severe Coronavirus disease 2019 (COVID-19) is associated with markers of disrupted gut permeability. We applied a multi-omic systems biology approach to analyze plasma samples from COVID-19 patients with varying disease severity and SARS-CoV-2 negative controls. We investigated the potential links between plasma markers of gut barrier integrity, microbial translocation, systemic inflammation, metabolome, lipidome, and glycome, and COVID-19 severity. We found that severe COVID-19 is associated with high levels of markers of tight junction permeability and translocation of bacterial and fungal products into the blood. These markers of disrupted intestinal barrier integrity and microbial translocation correlate strongly with higher levels of markers of systemic inflammation and immune activation, lower levels of markers of intestinal function, disrupted plasma metabolome and glycome, and higher mortality rate. Our study highlights an underappreciated factor with significant clinical implications, disruption in gut functions, as a potential force that may contribute to COVID-19 severity.

COVID-19 Severity Is Associated with Differential Antibody Fc-Mediated Innate Immune Functions.

Beyond neutralization, antibodies binding to their Fc receptors elicit several innate immune functions including antibody-dependent complement deposition (ADCD), antibody-dependent cell-mediated phagocytosis (ADCP), and antibody-dependent cell-mediated cytotoxicity (ADCC). These functions are beneficial, as they contribute to pathogen clearance; however, they also can induce inflammation. We tested the possibility that qualitative differences in SARS-CoV-2-specific antibody-mediated innate immune functions contribute to coronavirus disease 2019 (COVID-19) severity. We found that anti-S1 and anti-RBD antibodies from hospitalized COVID-19 patients elicited higher ADCD but lower ADCP compared to antibodies from nonhospitalized COVID-19 patients. Consistently, higher ADCD was associated with higher systemic inflammation, whereas higher ADCP was associated with lower systemic inflammation during COVID-19. Our study points to qualitative, differential features of anti-SARS-CoV-2 specific antibodies as potential contributors to COVID-19 severity. Understanding these qualitative features of natural and vaccine-induced antibodies will be important in achieving optimal efficacy and safety of SARS-CoV-2 vaccines and/or COVID-19 therapeutics.IMPORTANCE A state of hyperinflammation and increased complement activation has been associated with coronavirus disease 2019 (COVID-19) severity. However, the pathophysiological mechanisms that contribute to this phenomenon remain mostly unknown. Our data point to a qualitative, rather than quantitative, difference in SARS-CoV-2-specific antibodies' ability to elicit Fc-mediated innate immune functions as a potential contributor to COVID-19 severity and associated inflammation. These data highlight the need for further studies to understand these qualitative features and their potential contribution to COVID-19 severity. This understanding could be essential to develop antibody-based COVID-19 therapeutics and SARS-CoV-2 vaccines with an optimal balance between efficacy and safety.

Inappropriate medication use and polypharmacy in end-stage cancer patients: Isn't it the family doctor's role to de-prescribe much earlier?

BACKGROUND: Elderly patients are exposed to increased number of medications, often with no proof of a positive benefit/risk ratio. Unfortunately, this trend does not spare those with limited life expectancy, including end-stage cancer patients who require only palliative treatment. For many medications in this subpopulation, the risk of adverse drug events outweighs the possible benefits and yet, many are still poly-medicated during their last year of life. AIM: To describe the extent of polypharmacy among end-stage cancer patients, at the time of admission to homecare hospice. METHODS: A retrospective chart review of 202 patients admitted to Homecare Hospice of the Israel Cancer Association and died before January 2015. RESULTS: Average lifespan from admission until death was 39.2 ± 5.4 days. 63% died within the first month, 89% within 3 months. Excluding oncological treatments, 181 (90%) and 46 (23%) patients were treated with ≥ 6 and ≥ 12 drugs for chronic diseases, respectively. Two months before death, 32 (16%) patients were treated with ≥ 3 blood pressure lowering drugs, 62 (31%) with statins and 48 (23%) with aspirin. CONCLUSION: Though not representative of the whole end-stage cancer patient population, our study demonstrates that these patients are exposed to extensive polypharmacy. Most of these medications could have probably been safely de-prescribed much earlier in the course of the malignant disease. Considering the prolonged trust-based relationship with their patients, the family physicians are those who should be encouraged to implement the palliative approach and reduce polypharmacy much before reaching hospice settings.

Critical role of mitochondrial ROS is dependent on their site of production on the electron transport chain in ischemic heart.

Reactive oxygen species (ROS) generation has been implicated in many pathologies including ischemia/reperfusion (I/R) injury. This led to multiple studies on antioxidant therapies to treat cardiovascular diseases but paradoxically, results have so far been mixed as ROS production can be beneficial as a signaling mechanism and in cardiac protection via preconditioning interventions. We investigated whether the differential impact of increased ROS in injury as well as in protection could be explained by their site of production on the mitochondrial electron transport chain. Using amplex red to measure ROS production, we found that mitochondria isolated from hearts after I/R produced more ROS than non-ischemic when complex I substrate (glutamate/malate) was used. Interestingly, the substrates of complex II (succinate) and ubiquinone (sn-glycerol 3-phosphate, G3P) produced less ROS in mitochondria from I/R hearts compared to normal healthy hearts. The inhibitors of complex I (rotenone) and complex III (antimycin A) increased ROS production when glutamate/malate and G3P were used; in contrast, they reduced ROS production when the complex II substrate was used. Mitochondrial calcium retention capacity required to induce mitochondrial permeability transition pore (mPTP) opening was measured using calcium green fluorescence and was found to be higher when mitochondria were treated with G3P and succinate compared to glutamate/malate. Furthermore, Langendorff hearts treated with glutamate/malate exhibited reduced cardiac functional recovery and increased myocardial infarct size compared to hearts treated with G3P. Thus, ROS production by the stimulated respiratory chain complexes I and III has opposite roles: cardio-deleterious when produced in complex I and cardio-protective when produced in complex III. The mechanism of these ROS involves the inhibition of the mPTP opening, a key event in cell death following ischemia/reperfusion injury.