Action mechanism of microRNA-484 involved in myocardial fibrosis in hypertrophic cardiomyopathy / 中国胸心血管外科临床杂志

@#Objective     To search for the key microRNAs (miRNAs) involved in myocardial fibrosis in hypertrophic cardiomyopathy, and to further explore the mechanisms involved in the regulation of myocardial fibrosis. Methods    Forty-two patients with hypertrophic cardiomyopathy diagnosed and treated surgically in West China Hospital of Sichuan University from January 2014 to June 2018 were selected, including 29 males and 13 females, with a median age of 46 (15-69) years. In the myocardial tissue of patients with hypertrophic cardiomyopathy with different degrees of fibrosis, miRNAs with significantly different expression were screened and further verified at the cellular level. By regulating the expression of the target miRNAs, the expressions of fibrosis-related proteins and target genes were detected respectively. Finally, the target-binding relationship was verified by dual-luciferase reporter gene detection. Results    miR-484 was up-regulated in severely fibrotic myocardial tissue and activated cardiac fibroblasts. After cardiac fibroblasts were activated by TGF-β1, the expression of miR-484 was significantly up-regulated, the expression of fibrosis-related proteins (CollagenⅠ, α-SMA) increased, and the expression of the target gene HIPK1 decreased (P<0.05). After inhibiting the expression of miR-484 by transfection of miR-484 antagomir, the expression of fibrosis-related proteins decreased, while expression of HIPK1 was up-regulated (P<0.05). The detection of dual luciferase reporter gene showed that the luciferase activity of the transfected WT-miRNA-484 mimics group was lower than that of the control group (P<0.05). Conclusion    miR-484 is a pro-fibrotic miRNA that participates in the process of myocardial fibrosis by negatively regulating the expression of HIPK1. It can be used as a regulatory target to provide a therapeutic strategy for myocardial fibrosis.

Mid-term outcomes of tricuspid valve detachment versus non-detachment for ventricular septal defect closure / 中国胸心血管外科临床杂志

@#Objective 聽 聽To evaluate the mid-term outcomes between tricuspid valve detachment (TVD) and non-detachment (NTVD) for ventricular septal defect (VSD). Methods 聽 聽 The patients who underwent perimembranous VSD repair in the Department of Cardiovascular Surgery, West China Hospital from 2015 to 2020 were included. According to the surgical method, the patients were divided into a TVD group and a NTVD group. The clinical data of the two groups were compared. Results 聽 聽 Totally 538 patients were included in the study. There were 240 patients in the TVD group, including 121 males and 119 females, with an average age of 3.85卤8.42 years and an average weight of 14.12卤12.97 kg. There were 298 patients in the NTVD group, including 149 males and 149 females, with an average age of 4.42卤9.36 years and an average weight of 14.87卤12.51 kg. There was no statistical difference in the age, weight, sex, preoperative New York Heart Association (NYHA) classification or tricuspid regurgitation (TR) degree between the two groups (P>0.05). Median follow-up was 30 (23, 40) months in the TVD group, and 29 (23, 41) months in the NTVD group (P=0.600). After operation, one patient in each group developed third-degree atrioventricular block and recovered to sinus rhythm before discharge (P=0.848). No pacemaker was needed. There was no statistical difference in the length of stay (P=0.054), mortality (P=1.000), in-hospital reoperation (P=0.199), or follow-up reoperation (P=0.505). More than 98% of patients in both groups had postoperative TR less than moderate (P=0.926). At the last follow-up, only 7 (2.9%) patients in the TVD group were detected trivial residual shunting, and 14 (4.7%) in the NTVD group (P=0.289). No one needed to have reoperation because of residual VSD. The TVD group showed less TR during the follow-up (P=0.019). Conclusion     TVD is an alternative technique which can be safely used in the closure of VSD, especially in technologically mature medical center. Appropriate tricuspid valve detachment for those hard-to-expose VSDs does not result in poorer tricuspid valve function or higher risk of atrioventricular block, and might reduce the incidence of residual shunting.

The mechanism of volume-related mitral regurgitation from anatomy of mitral valve / 中国胸心血管外科临床杂志

@#Objective    To explore the mechanism of volume-related mitral regurgitation (MR) from the anatomy of mitral valve. Methods    A total of 32 patients with ventricular septal defect (VSD) combined MR meeting inclusion criteria in West China Hospital from September 2018 to November 2019 were enrolled in this study. The direction relative to the cardiac axis: the deviation of the MR bundle along the left atrial wall was eccentric, otherwises it was central. There were 23 patients of VSD and eccentric MR (EMR, a VSD-EMR group), including 10 males and 13 females aged 21 (10, 56) months, and 9 patients of VSD and central MR (CMR, a VSD-CMR group), including 4 males and 5 females aged 26 (12, 87) months. Besides, 9 healthy children were enrolled in a control group, including 4 males and 5 females aged 49 (15, 72) months. All patients underwent transthoracic echocardiography (TTE) examination at 2 weeks before surgery and 6 months after surgery, respectively, The MR degree, end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), antero-posterior diameter (AP), annulus circumference (AC), commissural diameter (CD) were assessed. Results    Before operation, EDV, ESV, SV, AP, AC and CD in the VSD-EMR and VSD-CMR groups were significantly larger or longer than those in the control group (P<0.05); after operation, EDV, ESV, SV, AP and CD decreased compared with those before operation (P<0.05), but there was no significant difference compared with the control group (P>0.05). Compared with the control group, AC was slightly decreased (P<0.05). There was no significant difference in EF between and within groups before and after operation (P>0.05). The improvement rate of MR was 78.9%(15/19) in the VSD-EMR group and 100.0% (9/9) in the VSD-CMR group. Conclusion    After unloading of volume, the valve structure is back to normal except AC. The improvement rate of MR in the VSD-EMR group is lower than that in the VSD-CMR group, which may indicate that the mechanism of VSD-EMR is more complicated.

Mid-term follow-up of perventricular device closure of subarterial ventricular septal defect / 中国胸心血管外科临床杂志

@#Objective    To evaluate the mid-term safety, efficacy and feasibility of perventricular device closure for subarterial ventricular septal defect. Methods    Clinical data of 97 patients diagnosed with subarterial ventricular septal defect through echocardiography in West China Hospital from September 2013 to December 2015 were retrospectively analyzed. There were 66 males and 31 females aged 3 (1.8, 5.9) years. All the patients underwent perventricular device closure under the guidance of transesophageal echocardiography using eccentric occlusion device. Possible complications such as residual shunt, valvular regurgitation, atrioventricular conduction block and arrhythmias were recorded during the 1-year, 3-year and 5-year follow-up. Results    All the patients received perventricular device closure successfully except that 1 patient underwent open surgical repair under cardiopulmonary bypass 3 months later because of the migration of device. So the rate of complete closure was 99.0%. No residual shunt, moderate or severe valvular regurgitation, atrioventricular conduction block or arrhythmias were observed 5 years later. Conclusion    Treating subarterial ventricular septal defect through perventricular device closure exhibits remarkable mid-term efficacy, safety and feasibility with high success rate.

Left ventricular outflow tract obstruction secondary to cone reconstruction for Ebstein’s anomaly: A case report / 中国胸心血管外科临床杂志

@#Left ventricular outflow tract obstruction (LVOTO) in Ebstein's anomaly is a rare complication, and LVOTO related to surgery is rarer. We present a 46 years old female patient who was dignosed with Ebstein's anomaly, then suffered from cardiac arrest because of LVOTO secondary to cone reconstruction in ICU.

Usefulness of real-time three-dimensional transesophageal echocardiography in the perventricular device occlusion of the ventricular septal defect / 中华超声影像学杂志

Objective To evaluate the usefulness of real-time three-dimensional transesophageal echocardiography (RT-3D TEE) in the perventricular device occlusion of the ventricular septal defect (VSD).Methods Sixty patients underwent perventricular device occlusion of VSD were divided into two groups.Group A:30 patients,3D images of VSD were obtained intraoperatively by RT-3D TEE.3D images were analyzed and the maximal and minimum area and maximal diameter of VSD were measured in the cardiac cycle.The size of selected VSD occluder was the diameter calculated from the maximal area based on the formula πD2/4 and plus 1～2 mm.Simultaneously,two dimensional transesophageal echocardiography (2D TEE) images of VSD were obtained and measured on standard views.Group B:other 30 patients,intraoperative 2D TEE was performed to measure the diameter of VSD on standard views.The selection VSD occluder was based on the maximal diameter plus 1～2 mm.Results The VSDs shape showed oval,class round and irregular by RT-3D TEE imaging.There was a significant difference between the maximal area and smallest area of VSD appeared in the cardiac cycle obtained by RT-3D TEE (P<0.01).There was a significant difference between the maximal diameter by measurement of RT-3D TEE and 2D TEE (P<0.01).Of all 30 patients with evaluation of VSD size based on the RT-3D TEE,1.1 times attempts of device occlusion were performed on one patient (33/30).Of the other 30 cases with evaluation of VSD size by 2D TEE,2 cases were failed with device occlusion because of instant residual shunt.Of the remaining 28 cases,1.43 attempts of device occlusion were performed on one patient (40/28).Conclusions RT-3D TEE can accurately reveal the size of VSD,and aid in the selection of VSD occluder in the device occluding procedure of VSD.

Modification of the method for establishing myocardial infarction model in rats / 生物医学工程学杂志

This study was conducted to modify the method for establishing the model of myocardial infarction by ligation of the left anterior descending branch (LAD) of coronary artery in rats, and then observations on them were made with the use of electrocardiography, heart function exam and histomorphology. 30 adult male inbred strain Wistar rats were randomly divided into two groups: sham group (n = 5) and model group (n = 25). Each rat in the model group underwent a ligation of the left anterior descending branch. Subsequently, the two groups were compared by use of electrocardiography, heart function and histomorphology. The results have demonstrated that, after being improved, the ligation of the left anterior descending branch of coronary artery is a good method to establish the stable model of myocardial infarction. It can be applied to the research in mechanism and treatment of myocardial infarction.

Application of transesophageal echocardiography on minimally invasive surgical closure of atrial and ventricular septal defects / 中华超声影像学杂志

Objective To evaluate the clinical value of transesophageal echocardiography (TEE) on minimally invasive surgical closure of heart septal defects. Methods Thirty-four patients with atrial septal defect (ASD) and 38 patients with ventricular septal defect(VSD) were selected by transthoracic echocardiography (TTE) prepared for minimally invasive surgical closure. TEE was performed to choose appropriate occluder and guide occluder release during the procedure. The immediate closure effect also evaluated by using TEE. A week follow-up was done by using TTE. Results Successful occlusion was in 32 patients with ASD and 29 patients with VSD. On 1 week follow-up,neither displacement for the occluders nor residual shunt except minimal residual shunt in 3 patients. The ventrieular remodeling was improved, the valvular regurgitation and pulmonary arterial pressure decreased. Conclusions TEE is important in minimally invasive surgical closure of atrial, ventricular septal defects, especially in choosing the candidate for the procedure and occluder, guiding occluder released and evaluating the procedure.

Changes of the metabolism of anti-oxidation competence of endothelial cells induced from mesenchymal stem cells after fluid shear stress loading / 生物医学工程学杂志

This study examined the effects of flow shear stress on the bio-capacity of the endothelial cells' induced from mesenchymal stem cells (MSCs). After cultivating the SD rat mesenchymal stem cells in vitro, we exposed them under different intensity of flow shear stress and induced these cells to endothelial cells. The variations of total anti-oxidation competence (T-AOC) and quantity of nitrogen monoxide (NO) were tested. The results showed that shear stress has an enhanced effect on the T-AOC and NO of endothelial cells induced from MSCs in an intensity-dependent manner. Flow shear stress could provide a protective action on the in vitro induction of endothelial cells, thus formulating a theoretical foundation for the therapeutics of ischemic heart diseases and vascular tissue engineering.

Synergistic myoprotection of L-arginine and adenosine in a canine model of global myocardial ischaemic reperfusion injury / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Endogenous nitric oxide and adenosine increase simultaneously to keep the balance of energy demand and supply when the oxygen supply is insufficient, which suggests that nitric oxide and adenosine might exert a synergistic myoprotection during tissue hypoxia. In this study, we tested this hypothesis utilizing a canine model of prolonged global myocardial ischaemic reperfusion injury.</p><p><b>METHODS</b>In this double blind, controlled study, the hearts of 24 anaesthetized mongrel dogs were arrested for 2 hours with aortic cross clamping and blood cardioplegia. The treatment groups were those supplemented with 2 mmol/L L-arginine (ARG), supplemented with 1 mmol/L adenosine (ADO), ARG + ADO supplemented with both, and no supplementation (control) (n = 6 in each group). Haemodynamics, biochemical indices, adenosine triphosphate (ATP) content and myeloperoxidase activities of myocardium were determined to evaluate myocardial injury. Statistical comparison was performed by two way ANOVA.</p><p><b>RESULTS</b>Although the requirements for inotropic supports were higher, the cardiac outputs were lower in control group than in ARG, ADO and the combination groups. Plasma cardiac troponin I levels were higher and the areas of hydropic changes were larger in control group than in ARG and ADO groups. Combination of arginine and adenosine provided further myoprotection with respect to better cardiac performance, lower release of cardiac troponin I, and smaller areas of hydropic changes compared with ARG and ADO groups. ATP content was higher, but myeloperoxidase activities of myocardium were significantly lower in the combination group than in control, ARG and ADO groups (P < 0.05).</p><p><b>CONCLUSIONS</b>Combination of L-arginine and adenosine provides synergistic myoprotection in a canine model of global myocardial ischaemia. Thus, the combination is recommended when the heart is exposed to a prolonged ischaemia during cardiac surgery.</p>

Effect of RGD peptide on adhesive stability of human umbilical vein endothelial cell on polyethylene terephthalate surface / 生物医学工程学杂志

In this study for exploring the effect of RGD peptide on adhesive stability of endothelial cells biomaterial surface, all materials were divided into three groups, RGD group (PET covalently grafted synthetic RGD peptides), control group (PET precoated with fibronectin) and blank group (Non-coated surface). Cultured human umbilical vein endothelial cells (HUVECs) were seeded on the materials, then adhesive stability of HUVECs on the varied PET surfaces was observed under steady flow condition, and effects of shear stress and shear time on adherent cells were compared. The results showed that the resistance adherent endothelial cells to detachment by flow was shear stress and shear time dependent. Comparison three groups under the same condition revealed that the ECs retention rates of RGD-grafted or fibronectin-coated group were much higher than that of the non-coated group. Under 8.19 dyne/cm2 shear stress after 4h, retention rates were 13.73% (blank group), 43.33% (RGD group) and 40.75% (control group) respectively. These data indicated that RGD peptide can improve the adhesive stability of endothelial cell on biomaterial and the effect of RGD in vivo needs further studies.

Effect of turbulent flow on adhesion molecules expression of vascular endothelial cells / 生物医学工程学杂志

Mechanical environment seems to be one of the most important surviving environment for vessel conduit and vascular endothelial cells(ECs), while adhesion is one of the most important physical characteristics of ECs. In this study, Flow chambers of steady laminar and turbulent flow are made and improved. Different flow-derived VCAM-1, ICAM-1 expressions are detected by laser confocal microscope. Spacial and temporal curves of the adhesion molecules are protracted. In laminar flow, expression of VCAM-1 is dramatically elevated, whereas the expression of ICAM-1 is transiently elevated and it immediately falls back to the baseline. In turbulent flow, expression of VCAM-1 declines, while expression of ICAM-1 slowly rises to a peak. These results indicate that such pathological flow field as turbulence exerts different influence on the adhesion of vascular ECs from laminar flow, and turbulence could be one of the most important reasons of the ECs structural and functional lesion.