Publications by authors named "Wing-Kuk Au"

Interferons (IFNs) are critical for immune defense against pathogens. While type-I and -III IFNs have been reported to inhibit SARS-CoV-2 replication, the antiviral effect and mechanism of type-II IFN against SARS-CoV-2 remain largely unknown. Here, we evaluate the antiviral activity of type-II IFN (IFNγ) using human lung epithelial cells (Calu3) and ex vivo human lung tissues.

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"Pan-coronavirus" antivirals targeting conserved viral components can be designed. Here, we show that the rationally engineered H84T-banana lectin (H84T-BanLec), which specifically recognizes high mannose found on viral proteins but seldom on healthy human cells, potently inhibits Middle East respiratory syndrome coronavirus (MERS-CoV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (including Omicron), and other human-pathogenic coronaviruses at nanomolar concentrations. H84T-BanLec protects against MERS-CoV and SARS-CoV-2 infection in vivo.

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Highly pathogenic coronaviruses, including severe acute respiratory syndrome coronavirus 2 (refs. ) (SARS-CoV-2), Middle East respiratory syndrome coronavirus (MERS-CoV) and SARS-CoV-1 (ref. ), vary in their transmissibility and pathogenicity.

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The airways and alveoli of the human respiratory tract are lined by two distinct types of epithelium, which are the primary targets of respiratory viruses. We previously established long-term expanding human lung epithelial organoids from lung tissues and developed a 'proximal' differentiation protocol to generate mucociliary airway organoids. However, a respiratory organoid system with bipotential of the airway and alveolar differentiation remains elusive.

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Background Strategies to improve long-term prediction of heart failure and death in valvular surgery are urgently needed because of an increasing number of procedures globally. This study sought to report the prevalence, changes, and prognostic implications of concomitant hepatorenal dysfunction and malnutrition in valvular surgery. Methods and Results In 909 patients undergoing valvular surgery, 3 groups were defined based on hepatorenal function (the modified model for end-stage liver disease excluding international normalized ratio score) and nutritional status (Controlling Nutritional Status score): normal hepatorenal function and nutrition (normal), hepatorenal dysfunction or malnutrition alone (mild), and concomitant hepatorenal dysfunction and malnutrition (severe).

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Background: The presence of tricuspid regurgitation (TR) is very common in patients with concomitant left-sided valve disease. Recent studies have advocated an additional grading of massive TR that is beyond severe. The present study sought to characterize the spectrum of TR in patients undergoing tricuspid annuloplasty (TA) and to evaluate the prognostic value of TR severity for post-operative outcome following TA.

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Article Synopsis
  • Clofazimine, an anti-leprosy drug approved by the FDA, shows promise in inhibiting various coronaviruses, including SARS-CoV-2 and MERS-CoV, by interfering with viral replication and cell fusion.
  • In studies with hamsters and in combination with remdesivir, clofazimine reduced viral loads and shedding while alleviating inflammation, making it a potential low-cost treatment option for COVID-19, especially in resource-limited settings.
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Understanding the factors that contribute to efficient SARS-CoV-2 infection of human cells may provide insights on SARS-CoV-2 transmissibility and pathogenesis, and reveal targets of intervention. Here, we analyze host and viral determinants essential for efficient SARS-CoV-2 infection in both human lung epithelial cells and ex vivo human lung tissues. We identify heparan sulfate as an important attachment factor for SARS-CoV-2 infection.

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Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging coronavirus that has resulted in more than 2 000 000 laboratory-confirmed cases including over 145 000 deaths. Although SARS-CoV-2 and SARS-CoV share a number of common clinical manifestations, SARS-CoV-2 appears to be highly efficient in person-to-person transmission and frequently causes asymptomatic or presymptomatic infections. However, the underlying mechanisms that confer these viral characteristics of high transmissibility and asymptomatic infection remain incompletely understood.

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Ventricular assist devices (VADs) are life-saving options for children with heart failure unresponsive to medical therapy as a bridge to transplantation or cardiac recovery. We present a retrospective review of 13 consecutive children who underwent implantation of VAD between 2001 and 2018 in our center. The median age was 12 years (1-17 years), weight was 45 kg (10-82 kg).

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Background: The advent of three-dimensional echocardiography (3DE) enables detailed evaluation of the tricuspid valve (TV) apparatus; nonetheless, the clinical value of preoperative 3DE is unknown in patients undergoing tricuspid annuloplasty (TA). The aim of this study was to evaluate the prognostic value of TV geometric parameters and leaflet coaptation status evaluated by 3DE in patients undergoing TA.

Methods: A total of 122 patients who underwent TA during left-sided heart valve surgery were prospectively evaluated.

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Background: Postcongenital heart surgery pulmonary regurgitation requires subsequent pulmonary valve replacement. We sought to compare the outcomes of pulmonary valve replacement after using bioprosthetic valves, porcine versus pericardial bioprosthesis.

Method: Retrospective single-center study of consecutive pulmonary valve replacement in patients with pulmonary regurgitation following initial congenital cardiac surgery.

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Background: The Model for End-stage Liver Disease excluding international normalized ratio (MELD-XI) score and the modified MELD score with albumin replacing international normalized ratio (MELD-Albumin) score, which reflect both liver and renal function, have been reported as predictors of adverse events in liver and heart disease. Nonetheless, their prognostic value in patients undergoing tricuspid annuloplasty has not been addressed.

Methods And Results: A total of 394 patients who underwent tricuspid annuloplasty were evaluated.

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Concomitant chronic kidney disease (CKD) is common in patients with significant valvular heart disease (VHD). This study sought to evaluate the clinical benefit of valvular surgery in patients with concomitant CKD.We evaluated 349 patients with significant VHD who were referred for surgery.

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Background: Large tumor suppressor 2 (LATS2) gene is a putative tumor suppressor gene with potential roles in regulation of cell proliferation and apoptosis in lung cancer. The aim of this study is to explore the association of aberrant LATS2 expression with EGFR mutation and survival in lung adenocarcinoma (AD), and the effects of LATS2 silencing in both lung AD cell lines.

Methods: LATS2 mRNA and protein expression in resected lung AD were correlated with demographic characteristics, EGFR mutation and survival.

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Cardiac progenitor cells play an important role in cardiac repair and regeneration; however, their cellular biology and electrophysiology are not understood. The present study characterizes the functional ion channels in human cardiac c-kit(+) progenitor cells using whole-cell patch voltage-clamp, RT-PCR, and Western blots. We found that several ionic currents were present in human cardiac c-kit(+) progenitor cells, including a large-conductance Ca(2+)-activated K(+) current (BKCa) in 86 % of cells, an inwardly rectifying K(+) current (I Kir) in 84 % of cells, a transient outward K(+) current (I to) in 47 % of cells, a voltage-gated tetrodotoxin-sensitive Na(+) current (I Na,TTX) in 61 % of cells.

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Transient receptor potential (TRP) channels are not well understood in human atrium, and the present study was therefore designed to investigate whether TRPC channels would mediate the nonselective cation current reported previously and are involved in the formation of store-operated Ca(2+) entry (SOCE) channels in human atrial myocytes using approaches of whole-cell patch voltage-clamp, RT-PCR, Western blotting, co-immunoprecipitation, and confocal scanning approaches, etc. We found that a nonselective cation current was recorded under K(+)-free conditions in human atrial myocytes, and the current was inhibited by the TRP channel blocker La(3+). Thapsigargin enhanced the current, and its effect was suppressed by La(3+) and prevented by pipette inclusion of anti-TRPC1 antibody.

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Tuberculous osteomyelitis of sternum after open heart surgery is a rare disease entity. We report a case of wound infection with osteomyelitis caused by Mycobacterium tuberculosis in a patient with diabetic nephropathy, requiring peritoneal dialysis after coronary artery bypass grafting, who was successfully treated with antituberculous agents and surgical debridement. In addition, we provide a literature review on reported cases of tuberculous sternal osteomyelitis and mediastinitis after open heart surgery, and discuss about the risk factors, clinical features, and treatment of this infection.

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Between October 1999 and December 2000, 52 patients (37 male) undergoing coronary artery bypass surgery were selected for overdrive biatrial pacing to determine its effectiveness in reducing atrial fibrillation. A pacing wire was attached to the right atrial appendage and another to the roof of the left atrium behind the aorta. The atria were paced continuously in AAI mode at a rate of 90 pulses per minute or 10 pulses above the underlying rate (maximum rate < 140/min) for 3 days.

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