Publications by authors named "Victor Chu"

Obeldesivir (ODV, GS-5245) is an orally administered prodrug of the parent nucleoside of remdesivir (RDV) and is presently in phase 3 trials for COVID-19 treatment. In this work, we show that ODV and its circulating parent nucleoside metabolite, GS-441524, have similar in vitro antiviral activity against filoviruses, including Marburg virus, Ebola virus, and Sudan virus (SUDV). We also report that once-daily oral ODV treatment of cynomolgus monkeys for 10 days beginning 24 hours after SUDV exposure confers 100% protection against lethal infection.

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Marburg virus (MARV) causes severe disease and high mortality in humans. The objective of this study was to characterize disease manifestations and pathogenesis in cynomolgus macaques exposed to MARV. The results of this natural history study may be used to identify features of MARV disease useful in defining the ideal treatment initiation time for subsequent evaluations of investigational therapeutics using this model.

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Article Synopsis
  • - The study aimed to evaluate how different anti-arrhythmic drugs (AADs) affect the restoration and maintenance of sinus rhythm in patients with atrial fibrillation (AF) undergoing electrical cardioversion.
  • - A systematic review and network meta-analysis of 28 randomized controlled trials found that Class III AADs and amiodarone significantly improved the acute restoration of sinus rhythm compared to no treatment or rate control.
  • - Amiodarone was shown to be the most effective in maintaining sinus rhythm long-term after electrical cardioversion, while Class Ic and Class III AADs also proved effective, albeit to a lesser extent.
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Objective: Diabetic macular edema (DME) is the primary cause of vision loss among individuals with diabetes mellitus (DM). We developed, validated, and tested a deep learning (DL) system for classifying DME using images from three common commercially available optical coherence tomography (OCT) devices.

Research Design And Methods: We trained and validated two versions of a multitask convolution neural network (CNN) to classify DME (center-involved DME [CI-DME], non-CI-DME, or absence of DME) using three-dimensional (3D) volume scans and 2D B-scans, respectively.

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Objectives: Breast cancer immunohistochemistry (IHC) biomarker testing is limited in low-resource settings, and an alternative solution is needed. A point-of-care mRNA STRAT4 breast cancer assay for ESR1, PGR, ERBB2, and MKi67, for use on the GeneXpert platform, has been recently validated on tissues from internationally accredited laboratories, showing excellent concordance with IHC.

Methods: We evaluated STRAT4/IHC ESR1/estrogen receptor (ER), ERBB2/human epidermal growth factor receptor 2 (HER2) concordance rates of 150 breast cancer tissues processed in Rwanda, with undocumented cold ischemic and fixation time.

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Importance: Although the heart team approach is recommended in revascularization guidelines, the frequency with which heart team decisions differ from those of the original treating interventional cardiologist is unknown.

Objective: To examine the difference in decisions between the heart team and the original treating interventional cardiologist for the treatment of patients with multivessel coronary artery disease.

Design, Setting, And Participants: In this cross-sectional study, 245 consecutive patients with multivessel coronary artery disease were recruited from 1 high-volume tertiary care referral center (185 patients were enrolled through a screening process, and 60 patients were retrospectively enrolled from the center's database).

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Nucleic acid amplification tests (NAATs) are the primary means of identifying acute infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Accurate and fast test results may permit more efficient use of protective and isolation resources and allow rapid therapeutic interventions. We evaluated the analytical and clinical performance characteristics of the Xpert Xpress SARS-CoV-2 (Xpert) test, a rapid, automated molecular test for SARS-CoV-2.

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Background: Cardiac surgery patients are at high risk for postoperative bleeding. Intravenous (IV) tranexamic acid (TxA) is a commonly used antifibrinolytic drug, but is associated with postoperative seizures. We conducted this pilot randomized controlled trial (RCT) to determine the feasibility of a larger trial that will be designed to investigate the impact of TxA administration route, intrapericardial (IP) vs IV, on postoperative bleeding and seizures.

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Aims: Clinicians frequently pre-treat patients with amiodarone to increase the efficacy of electrical cardioversion for atrial fibrillation (AF). Our objective was to determine the precise effects of amiodarone pre- and post-treatment on conversion efficacy and sinus rhythm maintenance.

Methods And Results: We conducted a systematic review and meta-analysis of trials comparing pre- and post-treatment for electrical cardioversion with amiodarone vs.

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Purpose: The methods (IHC/FISH) typically used to assess ER, PR, HER2, and Ki67 in FFPE specimens from breast cancer patients are difficult to set up, perform, and standardize for use in low and middle-income countries. Use of an automated diagnostic platform (GeneXpert®) and assay (Xpert® Breast Cancer STRAT4) that employs RT-qPCR to quantitate ESR1, PGR, ERBB2, and MKi67 mRNAs from formalin-fixed, paraffin-embedded (FFPE) tissues facilitates analyses in less than 3 h. This study compares breast cancer biomarker analyses using an RT-qPCR-based platform with analyses using standard IHC and FISH for assessment of the same biomarkers.

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Traumatic dissection of the innominate artery is a rare clinical entity. Management of a patient with motorsensory compromise and dissection extending to the subclavian and right common carotid arteries is quite rare and can be quite involved. Here we present such a case and discuss the unique peri-operative decision-making in the context of what is reported in the literature.

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Objectives: Patients with annular areas just above nominal S3 valve areas are at increased risk of over-sizing if a larger valve is implanted. We therefore evaluated the rate of permanent pacemaker (PPM) implantation associated with avoiding over-sizing by selective deployment balloon over-filling during transcatheter aortic valve replacement (TAVR) with the Sapien 3 (S3) valve.

Methods: We included consecutive patients treated with the S3 valve from January 2016 to May 2017.

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Historically, mRNA measurements have been tested on several commercially available platforms, but none have gained broad acceptance for assessment of HER2. An mRNA measurement, as a continuous value, has the potential for use in adjudication of the equivocal category. Here we use a real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) assay in a closed, single-use cartridge, automated system.

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Introduction: Neurological injury remains the major cause of morbidity and mortality following open aortic arch repair. Systemic hypothermia along with antegrade cerebral perfusion (ACP) is the accepted cerebral protection approach, with axillary artery cannulation being the most common technique used to establish ACP. More recently, innominate artery cannulation has been shown to be a safe and efficacious method for establishing ACP.

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Background: The gold-standard treatment of severe mitral regurgitation (MR) due to degenerative disease is valve repair, which is surgically performed with either a leaflet resection or leaflet preservation approach. Recent data suggest that functional mitral stenosis (MS) may occur following valve repair using a leaflet resection strategy, which adversely affects patient prognosis. A randomised comparison of these two approaches to mitral repair on functional MS has not been conducted.

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Despite probably being the most effective prophylactic drug for postoperative atrial fibrillation (POAF), amiodarone is reserved as a second-line agent because of its potential systemic side effects. Herein, we review the available experimental and clinical trials examining the effectiveness of intrapericardial (IPC) amiodarone administration in preventing POAF which, if confirmed by future studies, can have a significant impact on cardiac surgery practice.

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Repeated therapeutic plasma exchange (TPE) has been advocated to remove heparin-induced thrombocytopenia (HIT) IgG antibodies before cardiac/vascular surgery in patients who have serologically-confirmed acute or subacute HIT; for this situation, a negative platelet activation assay (eg, platelet serotonin-release assay [SRA]) has been recommended as the target serological end point to permit safe surgery. We compared reactivities in the SRA and an anti-PF4/heparin IgG-specific enzyme immunoassay (EIA), testing serial serum samples in a patient with recent (subacute) HIT who underwent serial TPE precardiac surgery, as well as for 15 other serially-diluted HIT sera. We observed that post-TPE/diluted HIT sera-when first testing SRA-negative-continue to test strongly positive by EIA-IgG.

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Transcatheter aortic valve implantation (TAVI) has become an option for patients with symptomatic severe aortic stenosis whose co-morbidities place them at high surgical risk. However, little is known regarding treatment allocation. From May 2008 to May 2011, all high-risk patients with symptomatic severe aortic stenosis referred to an experienced single-center TAVI clinic were reviewed.

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Objectives: This study sought to evaluate the long-term outcomes after transcatheter aortic valve implantation (TAVI) in the Multicenter Canadian Experience study, with special focus on the causes and predictors of late mortality and valve durability.

Background: Very few data exist on the long-term outcomes associated with TAVI.

Methods: This was a multicenter study including 339 patients considered to be nonoperable or at very high surgical risk (mean age: 81 ± 8 years; Society of Thoracic Surgeons score: 9.

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HCV infection is a major cause of chronic liver disease and liver cancer in the United States. To address the pathogenesis caused by HCV infection, recent studies have focused on the direct cytopathic effects of individual HCV proteins, with the objective of identifying their specific roles in the overall pathogenesis. However, this approach precludes examination of the possible interactions between different HCV proteins and organelles.

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Radial artery (RA) graft spasm is a major cause of early graft failure in coronary artery bypass grafting surgeries. We explored the feasibility of thermal reduction of smooth muscle mass to attenuate vasoconstriction. Rat and rabbit femoral arteries were treated thermally in situ (45°C to 65°C; 0 s to 120 s) and then excised at various time points for histological and physiological study (pressure-diameter relationships).

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Article Synopsis
  • The study aimed to assess the outcomes of a transcatheter aortic valve implantation (TAVI) program using both transfemoral and transapical techniques, particularly in patients considered inoperable due to porcelain aorta or frailty.
  • A total of 345 procedures were analyzed, revealing a 93.3% procedural success rate, with 30-day mortality at 10.4% and a median follow-up mortality rate of 22.1%, influenced by factors like sepsis and chronic diseases.
  • Results indicated that patients with porcelain aorta or frailty had similar acute outcomes as others and even showed better 1-year survival rates, suggesting TAVI is a viable option for high-risk patients.
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