Comparing the performance of published risk scores in Brugada syndrome: a multi-center cohort study.

The management of Brugada Syndrome (BrS) patients at intermediate risk of arrhythmic events remains controversial. The present study evaluated the predictive performance of different risk scores in an Asian BrS population and its intermediate risk subgroup. This retrospective cohort study included consecutive patients diagnosed with BrS from January 1 , 1997 to June 20 , 2020 from Hong Kong. The primary outcome is sustained ventricular tachyarrhythmias. Two novel risk risk scores and seven machine learning-based models (random survival forest, Ada boost classifier, Gaussian naïve Bayes, light gradient boosting machine, random forest classifier, gradient boosting classifier and decision tree classifier) were developed. The area under the receiver operator characteristic (ROC) curve (AUC) [95% confidence intervals] was compared between the different models. This study included 548 consecutive BrS patients (7% female, age at diagnosis: 50±16 years, follow-up: 84±55 months). For the whole cohort, the score developed by Sieira et al. showed the best performance (AUC: 0.806 [0.747-0.865]). A novel risk score was developed using the Sieira score and additional variables significant on univariable Cox regression (AUC: 0.855 [0.808-0.901]). A simpler score based on non-invasive results only showed a statistically comparable AUC (0.784 [0.724-0.845]), improved using random survival forests (AUC: 0.942 [0.913-0.964]). For the intermediate risk subgroup (N=274), a gradient boosting classifier model showed the best performance (AUC: 0.814 [0.791-0.832]). A simple risk score based on clinical and electrocardiographic variables showed a good performance for predicting VT/VF, improved using machine learning. Abstract: The management of Brugada Syndrome (BrS) patients at intermediate risk of arrhythmic events remains controversial. This study evaluated the predictive performance of published risk scores in a cohort of BrS patients from Hong Kong (N=548) and its intermediate risk subgroup (N=274). A novel risk score developed by modifying the best performing existing score (by. Sieira et al.) showed an area under the curve of 0.855 and 0.760 for the whole BrS cohort and the intermediate risk subgroup, respectively. The performance of the different scores was significantly improved machine learning-based methods, such as random survival forests and gradient boosting classifier. [Abstract copyright: Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.

Carboxyl-terminal truncated HBx regulates a distinct microRNA transcription program in Hepatocellular carcinoma development

Background: The biological pathways and functional properties by which misexpressed microRNAs (miRNAs) contribute to liver carcinogenesis have been intensively investigated. However, little is known about the upstream mechanisms that deregulate miRNA expressions in this process. In hepatocellular carcinoma (HCC), hepatitis B virus (HBV) X protein (HBx), a transcriptional trans-activator, is frequently expressed in truncated form without carboxyl-terminus but its role in miRNA expression and HCC development is unclear. Methods: Human non-tumorigenic hepatocytes were infected with lentivirus-expressing full-length and carboxyl-terminal truncated HBx (Ct-HBx) for cell growth assay and miRNA profiling. Chromatin immunoprecipitation microarray was performed to identify the miRNA promoters directly associated with HBx. Direct transcriptional control was verified by luciferase reporter assay. The differential miRNA expressions were further validated in a cohort of HBV-associated HCC tissues using real-time PCR. Results: Hepatocytes expressing Ct-HBx grew significantly faster than the full-length HBx counterparts. Ct-HBx decreased while full-length HBx increased the expression of a set of miRNAs with growth-suppressive functions. Interestingly, Ct-HBx bound to and inhibited the transcriptional activity of some of these miRNA promoters. Notably, some of the examined repressed-miRNAs (miR-26a, -29c, -146a and -190) were also significantly down-regulated in a subset of HCC tissues with carboxyl-terminal HBx truncation compared to their matching non-tumor tissues, highlighting the clinical relevance of our data. Conclusion: Our results suggest that Ct-HBx directly regulates miRNA transcription and in turn promotes hepatocellular proliferation, thus revealing a viral contribution of miRNA deregulation during hepatocarcinogenesis. © 2011 Yip et al.published_or_final_versio

Rapid diagnosis of a coronavirus associated with severe acute respiratory syndrome

Severe acute respiratory syndrome (SARS) is a recently emerged disease associated with pneumonia in infected patients (1). The disease is unusual in its severity, and patients suffering from this disease do not respond to empirical antimicrobial treatment for acute communityacquired typical or atypical pneumonia (2). By the end of March 2003, a cumulative total of 1622 cases and 58 deaths had been reported from 13 countries (3). The disease is highly infectious, and attach rates �56 % have been reported in healthcare workers caring for SARS patients (2). Recently, we identified a novel virus in the family Coronaviridae in SARS patients (4). Of patients from whom paired acute and convalescent sera were available, all had seroconverted or had a greater than fourfold increase in antibody titer to this novel virus (4), suggesting that i

Effect of transwell inserts on the induction of IL-6, CXCL1, CXCL8, CXCL10, CCL2 and CCL5 in co-culture of eosinophils and fibroblasts under IL-31 and IL-33 stimulation.

<p>Eosinophils (3×10⁵ cells) and confluent fibroblasts (1×10⁵ cells) were cultured together with or without IL-31 and/or IL-33 (50 ng/ml) in the presence or absence of transwell inserts for 24 h. Cytokines and chemokines released in culture supernatant were determined by either CBA or Bio-plex pro assay. Results are expressed as the arithmetic mean plus SD of three independent experiments. EF: co-culture of eosinophils and dermal fibroblasts *p<0.05 when compared with corresponding control without transwell insert.</p

Effect of IL-31 and IL-33 on the surface expression of ICAM-1 on eosinophils and fibroblasts in the co-culture.

<p>Eosinophils (3×10⁵ cells) and confluent fibroblasts (1×10⁵ cells) were cultured either together or separately with or without IL-31 and/or IL-33 (50 ng/ml) for 16 h. Surface expression of ICAM-1 on 10,000 cells was analyzed by flow cytometry as MFI. Results have been normalized by subtracting appropriate isotypic control and expressed as the arithmetic mean plus SD of three independent experiments. E: eosinophils only; coE: eosinophils in co-culture; F: dermal fibroblasts; coF: fibroblasts in co-culture *p<0.05, **p<0.01 when compared between groups denoted by horizontal lines.</p

Effects of signaling molecule inhibitors on the release of IL-6, CXCL1, CXCL8, CXCL10, CCL2 and CCL5 from co-culture of eosinophils and fibroblasts with or without IL-31 and IL-33 stimulation.

<p>Eosinophils (3×10⁵ cells) cultured together with confluent fibroblasts (1×10⁵ cells) were pretreated with BAY11-7082 (1 µM), LY294002 (5 µM), U0126 (10 µM), SP600125 (3 µM) or SB203580 (7.5 µM) for 45 min, followed by incubation with or without IL-31 or IL-33 (50 ng/ml) in the presence of inhibitors for further 24 h. Released cytokines and chemokines in culture supernatant were determined by either CBA or Bio-plex pro assay. Results are expressed as the arithmetic mean plus SD of three independent experiments. DMSO (0.1%) was used as the vehicle control. Ctrl: medium control; BAY: BAY11-7082, LY: LY294002, U: U0126, SB: SB203580, SP: SP600125 *p<0.05 when compared between treatment group and control cell group.</p

Source of IL-6, CXCL1, CXCL8, CXCL10, CCL2 and CCL5 in co-culture of eosinophils and fibroblasts under IL-31 and IL-33 stimulation.

<p>Eosinophils (3×10⁵ cells) and confluent fibroblasts (1×10⁵ cells) were treated with or without 1% paraformaldehyde for 1 h on ice prior to being cultured together with or without IL-31 and/or IL-33 (50 ng/ml) for 24 h. Cytokines and chemokines released in culture supernatant were determined by either CBA or Bio-plex pro assay. Results are expressed as the arithmetic mean plus SD of three independent experiments. E: unfixed eosinophils; E∧: fixed eosinophils; F: unfixed dermal fibroblasts; F∧: fixed dermal fibroblasts *p<0.05 when compared with corresponding unfixed control.</p

Effects of signaling molecule inhibitors on the cell surface expression of ICAM-1 on eosinophils or fibroblasts in the co-culture.

<p>Eosinophils (3×10⁵ cells) and confluent fibroblasts (1×10⁵ cells) cultured together, were pretreated with BAY11-7082 (1 µM), LY294002 (5 µM), U0126 (10 µM), SP600125 (3 µM) or SB203580 (7.5 µM) for 45 min, followed by incubation with or without IL-31 or IL-33 (50 ng/ml) in the presence of inhibitors for further 16 h. Surface expression of ICAM-1 on 10,000 cells was analyzed by flow cytometry as MFI. Results have been normalized by subtracting appropriate isotypic control and expressed as the arithmetic mean plus SD of three independent experiments. DMSO (0.1%) was used as the vehicle control. Ctrl: medium control; BAY: BAY11-7082, LY: LY294002, U: U0126, SB: SB203580, SP: SP600125 *p<0.05 when compared between treatment group and control cell group.</p

Surface expression of receptors for IL-31 and IL-33 on human eosinophils and fibroblasts.

<p>(A) Surface expression of OSMR-β, IL-31RA and ST2 on eosinophils, peripheral blood mononuclear cells (PBMC), neutrophils and fibroblasts (5×10⁵ cells) was determined Western blot. Triplicate experiments were performed with essentially identical results and representative figure is shown. Neutrophils and PBMC were served as cell controls, and β-actin was used as protein control to ensure an equal amount of loaded protein. (B) Surface expression of ST2 on fibroblasts was determined by flow cytometry. Results are expressed as representative histogram of relative cell counts with mean fluorescence intensity (MFI). (C) Functional activity of the receptor complex for IL-31 and IL-33. IL-31 or IL-33 (50 ng/ml) was added to eosinophils or fibrolasts (5×10⁵ cells) for 10 min. Phosphorylation of STAT3 (pSTAT3) in eosinophils and fibroblasts was determined by flow cytometry. Results are shown in MFI subtracting corresponding isotypic control and expressed as the arithmetic mean plus SD of three independent experiments in bar chart. Representative histograms illustrate the intracellular expression of pSTAT3 upon IL-31 or IL-33 stimulation in permeabilized eosinophils and fibroblasts. *p<0.05 comparing with corresponding medium control. EOS: eosinophils; NEU: neutrophils; FIB: dermal fibroblasts.</p