Protein–protein interactions (PPIs) form the foundation of any cell signaling network. Considering that PPIs are highly dynamic processes, cellular assays are often essential for their study because ...they closely mimic the biological complexities of cellular environments. However, incongruity may be observed across different PPI assays when investigating a protein partner of interest; these discrepancies can be partially attributed to the fusion of different large functional moieties, such as fluorescent proteins or enzymes, which can yield disparate perturbations to the protein’s stability, subcellular localization, and interaction partners depending on the given cellular assay. Owing to their smaller size, epitope tags may exhibit a diminished susceptibility to instigate such perturbations. However, while they have been widely used for detecting or manipulating proteins in vitro, epitope tags lack the in vivo traceability and functionality needed for intracellular biosensors. Herein, we develop NbV5, an intracellular nanobody binding the V5-tag, which is suitable for use in cellular assays commonly used to study PPIs such as BRET, NanoBiT, and Tango. The NbV5:V5 tag system has been applied to interrogate G protein–coupled receptor signaling, specifically by replacing larger functional moieties attached to the protein interactors, such as fluorescent or luminescent proteins (∼30 kDa), by the significantly smaller V5-tag peptide (1.4 kDa), and for microscopy imaging which is successfully detected by NbV5-based biosensors. Therefore, the NbV5:V5 tag system presents itself as a versatile tool for live-cell imaging and a befitting adaptation to existing cellular assays dedicated to probing PPIs.
Crohn’s disease (CD) is characterized by the chronic inflammation of the gastrointestinal tract. A dysbiotic microbiome and a defective immune system are linked to CD, where hydrogen sulfide (H2S) ...microbial producers positively correlate with the severity of the disease. Atopobium parvulum is a key H2S producer from the microbiome of CD patients. In this study, the biochemical characterization of two Atopobium parvulum cysteine desulfurases, ApSufS and ApCsdB, shows that the enzymes are allosterically regulated. Structural analyses reveal that ApSufS forms a dimer with conserved characteristics observed in type II cysteine desulfurases. Four residues surrounding the active site are essential to catalyse cysteine desulfurylation, and a segment of short‐chain residues grant access for substrate binding. A better understanding of ApSufS will help future avenues for CD treatment.
Atopobium parvulum populates the gastrointestinal tract of patients suffering from intestinal bowel diseases (IBDs), such as Crohn’s disease, and neutralization of H2S production reduces gut inflammation. The Atopobium parvulum cysteine desulfurase SufS (ApSufS) produces H2S, which may be a virulence factor in IBDs. Structure–activity relationship studies identified four critical residues for ApSufS activity, paving the way for identifying novel treatments for IBDs.
To compare the performance of various liver disease scoring systems in predicting early mortality after transjugular intrahepatic portosystemic shunt (TIPS) creation.
In this single-institution ...retrospective study, eight scoring systems were used to grade liver disease in 211 patients (male-to-female ratio = 131:80; mean age, 54 y) before TIPS creation from 1999-2011. Scoring systems included bilirubin level, Child-Pugh (CP) score, Model for End-Stage Liver Disease (MELD) and Model for End-Stage Liver Disease sodium (MELD-Na) score, Emory score, prognostic index (PI), Acute Physiology and Chronic Health Evaluation (APACHE) 2 score, and Bonn TIPS early mortality (BOTEM) score. Medical record review was used to identify 30-day and 90-day clinical outcomes. The relationship of scoring parameters with mortality outcomes was assessed with multivariate analysis, and the relative ability of systems to predict mortality after TIPS creation was evaluated by comparing area under receiver operating characteristic (AUROC) curves.
TIPS were successfully created for variceal hemorrhage (n = 121), ascites (n = 72), hepatic hydrothorax (n = 15), and portal vein thrombosis (n = 3). All scoring systems had a significant association with 30-day and 90-day mortality (P<.050 in each case) on multivariate analysis. Based on 30-day and 90-day AUROC, MELD (0.878, 0.816) and MELD-Na (0.863, 0.823) scores had the best capability to predict early mortality compared with bilirubin (0.786, 0.749), CP (0.822, 0.771), Emory (0.786, 0.681), PI (0.854, 0.760), APACHE 2 (0.836, 0.735), and BOTEM (0.798, 0.698), with statistical superiority over bilirubin, Emory, and BOTEM scores.
Several liver disease scoring systems have prognostic value for early mortality after TIPS creation. MELD and MELD-Na scores most effectively predict survival after TIPS creation.
The purpose of this article is to characterize the temporal evolution and clinical impact of laboratory liver function parameters after transjugular intrahepatic portosystemic shunt (TIPS) creation.
...In this single-institution retrospective study, 157 patients (98 men and 59 women; median age, 55 years) underwent TIPS between 2000 and 2012 and had 1-month hepatobiliary laboratory follow-up. Medical record review was used to compare baseline, peak, and low bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, and international normalized ratio (INR) levels within 30 days after TIPS in surviving and dying patients to assess laboratory responses to shunt creation.
TIPSs were created with a hemodynamic success rate of 98%, with median pressure gradient reduction of 13 mm Hg. Ninety-day mortality was 21%. Hepatobiliary laboratory values showed significant increases in the days after TIPS compared with baseline levels (bilirubin, 1.6 vs 3.5 mg/dL; AST, 49 vs 149 U/L; ALT, 26 vs 90 U/L; alkaline phosphatase, 97 vs 177 U/L; and INR, 1.5 vs 2.0; p<0.05 in all cases). Patients surviving to 90 days experienced statistically significant but transient laboratory value elevations-up to twofold over baseline-within days of TIPS, whereas patients dying within 90 days experienced three-to fourfold increases over a longer period that did not return to baseline. Differences in laboratory evolution were statistically significant in surviving versus dying patients.
TIPS results in acute transient elevation of hepatobiliary enzymes, which may be more pronounced in patients with early mortality. An exaggerated laboratory elevation in excess of threefold greater than baseline or a prolonged increase exceeding 1 week may herald poorer clinical outcome.
The objective of this study was to examine the value of stress-echocardiography in patients with paradoxical low-flow, low-gradient (PLFLG) aortic stenosis (AS). The projected aortic valve area ...(AVAProj ) at a normal flow rate was calculated in 55 patients with PLFLG AS. In the subset of patients (n = 13) who underwent an aortic valve replacement within 3 months after stress echocardiography, AVAProj correlated better with the valve weight compared to traditional resting and stress echocardiographic parameters of AS severity (AVAProj : r = −0.78 vs. other parameters: r = 0.46 to 0.56). In the whole group (N = 55), 18 (33%) patients had an AVAProj >1.0 cm2 , being consistent with the presence of pseudo severe AS. The AVAProj was also superior to traditional parameters of stenosis severity for predicting outcomes (hazard ratio: 1.32/0.1 cm2 decrease in AVAProj ). In patients with PLFLG AS, the measurement of AVAproj derived from stress echocardiography is helpful to determine the actual severity of the stenosis and predict risk of adverse events.
Improving care transitions for older adults can reduce emergency department (ED) visits, adverse events, and empower community autonomy. We conducted an inductive qualitative content analysis to ...identify themes emerging from comments to better understand ED care transitions.
The LEARNING WISDOM prospective longitudinal observational cohort includes older adults (≥ 65 years) who experienced a care transition after an ED visit from both before and during COVID-19. Their comments on this transition were collected via phone interview and transcribed. We conducted an inductive qualitative content analysis with randomly selected comments until saturation. Themes that arose from comments were coded and organized into frequencies and proportions. We followed the Standards for Reporting Qualitative Research (SRQR).
Comments from 690 patients (339 pre-COVID, 351 during COVID) composed of 351 women (50.9%) and 339 men (49.1%) were analyzed. Patients were satisfied with acute emergency care, and the proportion of patients with positive acute care experiences increased with the COVID-19 pandemic. Negative patient comments were most often related to communication between health providers across the care continuum and the professionalism of personnel in the ED. Comments concerning home care became more neutral with the COVID-19 pandemic.
Patients were satisfied overall with acute care but reported gaps in professionalism and follow-up communication between providers. Comments may have changed in tone from positive to neutral regarding home care over the COVID-19 pandemic due to service slowdowns. Addressing these concerns may improve the quality of care transitions and provide future pandemic mitigation strategies.
To identify prognostic factors for early mortality among patients with intermediate-risk Model for End-stage Liver Disease (MELD) scores undergoing transjugular intrahepatic portosystemic shunt ...(TIPS) creation.
In this single-institution retrospective study, 47 patients (31 men; mean age, 54 y) with intermediate MELD scores (ie, 18-25) underwent TIPS creation between 1999 and 2012. Medical records were reviewed to identify demographic (age, sex), liver disease (Child-Pugh, MELD), and procedure data (indication, urgency, stent type, portosystemic pressure gradient reduction, complications), and the influence of these parameters on 90-day mortality was assessed by multivariate binary logistic regression analysis.
TIPSs were successfully created for variceal hemorrhage (n = 24), ascites (n = 17), hydrothorax (n = 5), and portal vein thrombosis (n = 1). Hemodynamic success rate was 94% (44 of 47), and mean portosystemic pressure gradient reduction was 13 mm Hg. The 90-day mortality rate was 36% (17 of 47). Patient age (P = .026) was significantly associated with 90-day mortality. Mean ages of living versus dead patients were 51 and 60 years, and mortality rates in patients aged 54 years or younger versus 55 years or older were 21% (five of 24) and 52% (12 of 23), respectively. There was no difference in MELD scores between these age groups (20.6 vs 21.0; P = .600), and MELD score was not a predictive factor on regression analysis.
Age is a prognostic factor for early mortality in TIPS recipients with intermediate MELD scores. Mortality rates are higher in patients at least 55 years of age, but MELD score does not predict survival in this subset. Age should be contemplated when selecting patients at intermediate risk for TIPS creation.
Varices commonly occur in liver cirrhosis patients and are classified as esophageal (EV), gastroesophageal (GEV), or isolated gastric (IGV) varices. These vessels may be supplied and drained by ...several different afferent and efferent pathways. A working knowledge of variceal anatomy is imperative for Interventional Radiologists performing transjugular intrahepatic portosystemic shunt and embolization/obliteration procedures. This pictorial essay characterizes the angiographic anatomy of varices in terms of type and frequency of venous filling and drainage, showing that different varices have distinct vascular anatomy. EVs typically show left gastric vein filling and "uphill" drainage, and GEVs and IGVs exhibit additional posterior/short gastric vein contribution and "downhill" outflow. An understanding of these variceal filling and drainage pathways can facilitate successful portal decompression and embolization/obliteration procedures.
Abstract Many developments have occurred since the publication of the widely-used 2009 Canadian Cardiovascular Society (CCS) Dyslipidemia guidelines. Here, we present an updated version of the ...guidelines, incorporating new recommendations based on recent findings and harmonizing CCS guidelines with those from other Societies. The G rading of R ecommendations A ssessment, D evelopment and E valuation (GRADE) system was used, per present standards of the CCS. The total cardiovascular disease Framingham Risk Score (FRS), modified for a family history of premature coronary disease, is recommended for risk assessment. Low-density lipoprotein cholesterol remains the primary target of therapy. However, non-high density lipoprotein cholesterol has been added to apolipoprotein B as an alternate target. There is an increased emphasis on treatment of higher risk patients, including those with chronic kidney disease and high risk hypertension. The primary panel has recommended a judicious use of secondary testing for subjects in whom the need for statin therapy is unclear. Expanded information on health behaviours is presented and is the backbone of risk reduction in all subjects. Finally, a systematic approach to statin intolerance is advocated to maximize appropriate use of lipid-lowering therapy. This document presents the recommendations and principal conclusions of this process. Along with associated Supplementary Material that can be accessed online, this document will be part of a program of knowledge translation. The goal is to increase the appropriate use of evidence-based cardiovascular disease event risk assessment in the management of dyslipidemia as a fundamental means of reducing global risk in the Canadian population.
To assess within-patient temporal variability in Model for End Stage Liver Disease (MELD) scores and impact on outcome prognostication after transjugular intrahepatic portosystemic shunt (TIPS) ...creation.
In this single institution retrospective study, MELD score was calculated in 68 patients (M:F = 42:26, mean age 55 years) at 4 pre-procedure time points (1, 2-6, 7-14, and 15-35 days) before TIPS creation. Medical record review was used to identify 30- and 90-day clinical outcomes. Within-patient variability in pre-procedure MELD scores was assessed using repeated measures analysis of variance, and the ability of MELD scores at different time points to predict post-TIPS mortality was evaluated by comparing area under receiver operating characteristic (AUROC) curves.
TIPS were successfully created for ascites (n = 30), variceal hemorrhage (n = 29), hepatic hydrothorax (n = 8), and portal vein thrombosis (n = 1). Pre-TIPS MELD scores showed significant (P = 0.032) within-subject variance that approached ± 18.5%. Higher MELD scores demonstrated greater variability in sequential scores as compared to lower MELD scores. Overall 30- and 90-day patient mortality was 22% (15/67) and 38% (24/64). AUROC curves showed that most recent MELD scores performed on the day of TIPS had superior predictive capacity for 30- (0.876, P = 0.037) and 90-day (0.805 P = 0.020) mortality compared to MELD scores performed 2-6 or 7-14 days prior.
In conclusion, MELD scores show within-patient variability over time, and scores calculated on the day of TIPS most accurately predict risk and should be used for patient selection and counseling.
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