Que Zhu

Chongqing Medical University, Ch’ung-ch’ing-shih, Chongqing Shi, China

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Publications (9)59.27 Total impact

  • No preview · Article · Oct 2015 · Journal of the American College of Cardiology

  • No preview · Article · Aug 2015 · Hypertension
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    ABSTRACT: Objectives: The objective of this study was to determine the effect of inhibiting malonyl-CoA decarboxylase (MCD) on cardiac remodeling following myocardial infarction (MI) in rats. We used an ultrasound (US)-mediated microbubble (MB) approach for targeted delivery of a microRNA (miRNA) interference plasmid to the myocardium to silence MCD expression. Methods: Five pairs of RNA interference sequences were screened and ranked according to their highest inhibition rates in HEK293 cells. The plasmid with the highest inhibition rate was transfected by US into the rat myocardium after mixing with lipid MB. Twelve and 16 weeks after MI, cardiac function was measured by echocardiography, and glucose transporter-4 (GLUT-4) and high-energy phosphate levels were monitored in the myocardium before and after transfection. Results: Ejection fraction (EF) decreased by 16% in the control MI group, while it decreased by 8% in the MCD inhibition group that utilized the US-mediated MB approach. Concomitant with the improved EF, high-energy phosphates were increased and lactic acid was decreased in the left ventricle (LV), with no changes in triglyceride or GLUT-4 levels. Conclusions: Inhibiting MCD by an US-mediated injection of miRNA into the rat myocardium increased energy reserves in the LV after MI, most likely by limiting lactic acidosis and improving cardiac function without increasing lipid toxicity.
    No preview · Article · Jan 2014 · Cardiology
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    ABSTRACT: High-intensity focused ultrasound (HIFU) can achieve accurate and focused deep tissue ablation through an extracorporeal emission. Cardiac ablation using HIFU applied transthoracically must overcome potential interference from intervening thoracic structures. The aim of this study was to explore the efficacy and safety of septal ablation that was induced using transthoracic HIFU. Twenty-one canines were pretreated to improve acoustic transmission. Single ablations were induced by targeting transthoracic HIFU with acoustic power of 400 W for 3 sec at the middle and basal septum in eight canines. Extended ablations were performed to create larger lesions at the basal septum in eight more canines. The three-dimensional morphology of a basal septum lesion induced by a single ablation was analyzed. The temperature at the ablative targets was measured in the other five canines. The cardiomyocytes in the lesions underwent necrosis with a clear boundary. The three-dimensional morphology of the lesions appeared approximately as ellipsoids with a flatter endocardial side. The peak temperature at a power of 400 W for 3 sec was 93.27 ± 2.54°C, and it remained >50°C for nearly 10 sec. No procedure-related complications were observed. Ultrasound-guided transthoracic HIFU has the potential to safely create small dot or large mass lesions in the septum without a thoracotomy or a catheter.
    No preview · Article · Jul 2013 · Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography
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    ABSTRACT: OBJECTIVES: The feasibility of noninvasive renal sympathetic denervation (RSD) using the novel approach of extracorporeal high-intensity focused ultrasound (HIFU) was investigated in this study. BACKGROUND: Catheter-based RSD has achieved promising clinical outcomes. METHODS: Under the guidance of Doppler flow imaging, therapeutic ablations (250 W×2 seconds) were performed by extracorporeal HIFU on the bilateral renal nerves (36.3±2.8 HIFU emissions in each animal) in an average 27.4-minute procedure in 18 healthy canines of the ablation group. Similar procedures without acoustic energy treatment were conducted in 5 canines of the sham group. The animals were sacrificed on day 6 or 28. The blood pressure (BP), plasma noradrenaline (NA) level and renal function were determined on days 0, 6 and 28. Pathological examinations were performed on all retrieved samples. RESULTS: All of the animals survived the treatment. After ablation, the BP and NA significantly decreased compared to the baseline values (Bp changed -15.9/-13.6mmHg, NA changed -55.4%, p<0.001, respectively, on 28 days after ablation) and compared to the sham group on days 6 and 28. Ablation lesions around the renal artery adventitia were observed on day 6. A histologic examination revealed the disruption of nerve fibers, necrosis of Schwann cells and neurons, and apparent denervation on day 28. No procedure-related complications were observed. CONCLUSIONS: Effective RSD was successfully achieved using the extracorporeal HIFU method in canines. Thus, noninvasive HIFU may be further explored as an important and novel strategy for RSD.
    Full-text · Article · Mar 2013 · Journal of the American College of Cardiology
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    Full-text · Article · Feb 2013 · International journal of cardiology
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    ABSTRACT: The purpose of this study was to investigate whether transmyocardial jet revascularization (TMJR) with chitosan scaffolds retains channel patency and enhances angiogenesis after acute myocardial infarction (AMI) in a canine model. A total of 32 canines were randomly divided into four groups: myocardial infarction (MI), normal saline (NS), chitosan hydrogel (CH), and chitosan plus growth factor (CH + GF) groups. TMJR was performed surgically using a needle-free injector from the epicardium of canines in the NS, CH, and CH + GF groups; channels were filled with NS, CH, and CH + GF, respectively. After 6 weeks, the patency of the channels and angiogenesis around the channels were assessed by hematoxylin-eosin staining, immunohistochemistry, and Masson's trichrome staining. Results suggest that the channels in the CH and CH + GF groups may retain patency with luminal endothelization. Moreover, the vessel densities of the NS, CH, and CH + GF groups were significantly higher than that of the MI group, and that of the CH + GF group was the highest (p < 0.05). This study suggests that TMJR with chitosan scaffolds may help retain transmyocardial channel patency and enhance angiogenesis after AMI in canines. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
    No preview · Article · Feb 2013 · Journal of Biomedical Materials Research Part A
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    ABSTRACT: BACKGROUND: Transendocardial gene delivery may expose patients to the risk of pericardial perfusion due to excessive needle injections. This study investigated the feasibility and safety of transendocardial gene injection using a newly developed multifunctional intracardiac echocardiography catheter. METHODS: This new system integrated intracardiac echocardiography, a retractable 29-G needle, and other accessories into a single catheter (10F) that could be delivered into the left ventricle via a retrograde aortic approach. In three canines, the catheter was used to inject 0.2ml of Evan's blue; six canines received myocardial injections of plasmid containing the EGFP transgene. In addition, two canines received transendocardial injections of a pAdTrace-bFGF plasmid. All canines receiving gene delivery were sacrificed after 3days. The hearts were harvested for gross, histological examination and gene expression assessment. RESULTS: This catheter provided visual guidance for accurate needle-tip positioning within the target myocardium; the needle position was subsequently confirmed by microbubble infusion. No animal had pericardial effusion or sustained ventricular arrhythmia. Tissue staining showed well-demarcated margins within the target myocardium. In animals injected with pEGFP-N1, confocal microscopy demonstrated successful gene expression. In zones where pAdTrace-bFGF was injected, immunohistochemistry also showed positive staining. Compared to normal tissue (0.38±0.04), RT-PCR showed high levels of bFGF expression (0.63±0.02) in the target area (P<0.01). CONCLUSIONS: Transendocardial gene injection using a multifunctional intracardiac echocardiography catheter is feasible and could improve procedure-related safety which may provide a new strategy for transgene delivery in future.
    No preview · Article · Oct 2011 · International journal of cardiology
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    ABSTRACT: To evaluate the feasibility and safety of a novel multifunctional intracardiac echocardiography catheter for target septal ablation with transendocardial ethanol injection in canines. Percutaneous transluminal septal myocardial ablation has been the primary catheter-based strategy for the treatment of hypertrophic obstructive cardiomyopathy (HOCM). However, inherent limitations of the technique have reduced its therapeutic efficacy. A new catheter (10 F), integrated with a nitinol needle (29 G) and a 6.5-10-MHz, 32-element, side-fire ultrasound imaging transducer, was delivered into the right ventricle in nine canines and the left ventricle in three canines. A 0.3-ml microbubble and 0.5-1.5 ml absolute ethanol were sequentially injected into the interventricular septum. Electrocardiograph recordings were obtained during the whole procedure. Three hours after this operation, the heart was harvested for gross and histological examination. In all canines, the catheter provided the structural support and helped guide proper needle position within the septum. The microbubble further allowed the confirmation of the needle location through focal echo-density enhancement. Different amounts of ethanol infusion produced a dose-related effect on myocardial ablation. Macroscopic examination showed that the target myocardium became pale with a distinct border between lesions and normal tissue. Hematoxylin and eosin staining further confirmed necrosis within the injection region. Transendocardial ethanol injection at the interventricular septum resulted in controlled myocardial infarction. In addition, the injection depth could be visually followed using this new system, which may provide a safer and more intuitive method for the treatment of HOCM or other cardiomyopathies.
    No preview · Article · Aug 2011 · Catheterization and Cardiovascular Interventions