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find Author "CHEN Si" 10 results
  • Current Application and Progress of Hybrid Procedure in Cardiovascular Surgery

    Hybrid cardiovascular surgical procedure is an emerging concept that combines the skills and techniques of minimally invasive surgery and interventional catheterization. It allows surgeons to use interventional equipment and techniques during operations, which are traditionally used by physicians, in order to reduce the magnitude of therapeutic interventions and to increase therapeutic effectiveness. This review provides a snapshot of the main application and progress of current hybrid procedures in the field of cardiovascular surgery, including the hybrid therapy of coronary artery disease, congenital heart disease and thoracic aortic aneurysm, also discusses the precondition with which the hybrid procedure should ideally be performed.

    Release date:2016-08-30 06:10 Export PDF Favorites Scan
  • Preparation and osteogenic properties of poly (L-lactic acid)/lecithin porous scaffolds with open pore structure

    ObjectiveTo investigate the preparation and osteogenic properties of poly (L-lactic acid)(PLLA)/lecithin porous scaffolds with open pore structure.MethodsPLLA/lecithin porous scaffolds with different lecithin contents (0, 5%, 10%, 20%, 30%, 40%, 50%) were prepared by thermally induced phase separation (groups A, B, C, D, E, F, and G, respectively). Scanning electron microscopy (SEM) was used to observe the surface morphology of the scaffolds. Wide-angle X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to detect the crystallinity of the scaffolds. The water uptake ability of the scaffolds was measured. The cell growth and viability of bone marrow mesenchymal stem cells (BMSCs) of mouse on each scaffold was assessed by cell counting kit 8 (CCK-8) method. The osteogenic differentiation ability of BMSCs on each scaffold was evaluated by alkaline phosphatase (ALP) activity. Finally, a critical-size rat calvarial bone defect model was used to evaluate the osteogenesis of the scaffolds in vivo. Micro-CT was used to reconstruct the three-dimensional model of the defect area, and the bone volume and bone mineral density were quantitatively analyzed.ResultsSEM results showed that the lecithin could slightly reduce the pore size; when lecithin content was 50%, platelet-like structure could be observed on the scaffolds. Wide angle XRD and DSC showed that the crystallinity of scaffolds gradually decreased with the increase of lecithin content. The water uptake ability test showed that the hydrophilicity of scaffolds increased with the increase of lecithin content. CCK-8 assay showed that cell activity gradually increased with the increase of culture time. After 7 days of culture, the absorbance (A) value of groups C, D, E, and F were significantly higher than that of groups A, B, and G (P<0.05), but no significant difference was found among groups C, D, E, and F (P>0.05). After 14 days of osteogenic induction, with the increase of lecithin content, there was a significant difference in ALP activity of each group. The ALP activity in groups D, E, F, and G were significantly higher than that in groups A, B, and C (P<0.05).In vivo, the results of Micro-CT examination and bone volume and bone mineral density showed that the scaffolds with 30% lecithin had the best repairing effect.ConclusionPrepared by thermally induced phase separation, the cytocompatibility, osteogenic differentiation, and bone repair ability of the PLLA/lecithin porous scaffold is obviously better than that of pure PLLA scaffold. PLLA/lecithin porous scaffold with suitable lecithin content is a promising scaffold material for bone tissue engineering.

    Release date:2018-09-03 10:13 Export PDF Favorites Scan
  • Experimental Study of Induced Calcification in Aortic Valvular Interstitial Cells in Vitro

    Abstract: Objective To induce calcification in aortic valvular interstitial cells (VICs) in vitro and observe the shift of cellular phenotype during the process. Methods Porcine aortic VICs were isolated and expanded by collagenase methods. Fluorescent staining was performed to identify the interstitial cells. VICs at 48 passages were used for experiments. The cells were divided into two groups: the experimental group in which cells were cultured in osteogenic media supplemented with βglycerophosphate, vitamin C and dexamethasone, and the control group in which cells were cultured in normal media. After 2 weeks, calcified nodules were quantified. Calcium deposit was stained and measured by Alizarin Red S staining and assay. Real time reverse transcription polymerase chain reaction (RTPCR) was performed to measure expression of alpha smooth muscle actin (α-SMA) and calcification related factors such as osteocalcin, osteopontin and Corebinding factor α1/Runx2 (Cbfα1/Runx2). Results VICs were successfully harvested from porcine aortic valves, identified by positive staining of α-SMA, vimentin and negative staining of Von Willebrand factor (vWF). VICs could calcify after 2 weeks of osteogenic induction with calcified nodules formed. Quantification of calcified nodules and calcification deposit were significantly higher (Plt;0.05) in the experimental group than those in the control group (156.25±17.38 vs. 2.50±1.29, 17.52±2.04 vs. 1.00±0.22). Real Time RT-PCR indicated that expression of α-SMA, as well as calcification related markers like osteocalcin, osteopontin and Cbfα1/Runx2 was much higher in the experimental group than those in the control group (Plt;0.05). Conclusion VICs are activated during the progress of calcification with phenotype shifting to contraction and ossification, which might be the pathological basis of valvular calcification.

    Release date:2016-08-30 06:02 Export PDF Favorites Scan
  • Research progress of methods allowing quantitative analysis of aortic valve calcification

    With the development of social economy and medicine, degenerative heart valve disease has become the major part in heart valve disease. Calcific aortic valve disease (CAVD) is one of the most representative manifestations of degenerative valvular disease. Aortic valve calcification (AVC) has been found to be a strong predictor of major cardiovascular events, which makes it necessary to identify an effective way to evaluate the degree of AVC. Numerous methods of quantitative assessment of AVC have been reported. Here, we discuss these methods from the aspects of pathology and imageology.

    Release date:2018-09-25 04:15 Export PDF Favorites Scan
  • Synchronous or Metachronous Primary Cancers of Other Organs in 103 Patients with Gastric Cancer

    Objective To study the incidence,clinicopathological characteristics,diagnosis,treatment, and prognosis of synchronous or metachronous primary cancers in patients with gastric cancer. Methods The clinical data of 103 gastric cancer patients with synchronous or metachronous primary cancers from January 1983 to December 2010 were collected and reviewed.Results The incidence of synchronous or metachronous primary cancer in addition to gastric cancer was 2.26%(103/4 552).The age of these patients was (63.98±11.93) years (30~84 years) when gastric cancer was diagnosed.There were 29 cases of synchronous primary cancer and 74 cases of metachronous primary cancer,in which there were 46 pre-metachronous cancer patients and 28 post-metachronous cancer patients.All the patients had 113 primary tumors of other organs.Colorectal cancer was the most common type of primary cancer in other organs (27.43%, 31/113),followed by lung cancer (15.04%, 17/113).The time interval between gastric cancer and metachronous primary cancer was (87.95±92.98) months (7~506 months),and 65.49% (74/113) of other primary tumors were diagnosed within 5 years before or after gastric cancer. The overall 5-year survival rate was 48.43%. The 5-year survival rate of post-metachronous group (69.52%) was significantly better than synchronous cancer group (36.40%, P=0.009) or pre-metachronous group (42.31%, P=0.023).In 33 patients who had definite cause of death, 20 patients died of gastric cancer.Conclusions Primary cancer of other organs should be considered in treatment of gastric cancer.Gastric cancer may be the most important factor impacting the prognosis of these patients.

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  • Establishment of a benign tracheal stenosis model in rats by nylon brush scraping induced mechanical injury

    ObjectiveTo establish a simple and stable model of benign tracheal stenosis in SD rats by nylon brush scraping induced mechanical injury, and to observe the pathological changes of tracheal tissue at different time points after modeling.MethodsTwenty SD rats were divided into sham operation group (10 rats) and stenosis model group (10 rats) by random number method. Symptoms and survival conditions were observed, tracheal tissues were obtained, granulation tissue proliferation was observed, and stenosis indexes were measured and compared. Another fifteen rats were sacrificed at different time points (days 0, 2, 4, 6, and 8) after modeling. Tracheal tissues were obtained, HE staining and Masson staining were performed to observe pathological changes with time.ResultsThe survival rate of the sham operation group was 100% on the 8th day after operation, and the survival rate was 0% on the 8th day after operation in the stenosis model group. The difference in survival condition between the two groups was statistically significant (P=0.000 1) by Log-rank test. The stenosis index in the sham operation group was (6.12±1.78)%, and in the stenosis model group was (60.28±12.56)%. The difference in the stenosis between the two groups was statistically significant (P<0.000 01). HE staining results showed that the tracheal lumen was unobstructed and no granulation tissue hyperplasia or stenosis was found in the sham operation group. The epithelial mucosa was intact and smooth, and the cilia structure was clearly visible. It was a pseudo-stratified ciliated columnar epithelium, which was consistent with the characteristics of normal airway mucosa. While in stenosis model group, the lumen was significantly narrowed, and the stenosis was mainly caused by granulation tissue hyperplasia. No epithelial structure was observed, or epithelial structure was extremely abnormal. Masson staining showed that the fibroblasts in the injured site increased first and then decreased, and the collagenous fiber (blue) in the injured site gradually increased with time.ConclusionsA model of benign tracheal stenosis in rats can be successfully established by nylon brush scraping induced mechanical injury. The modeling method is simple, controllable and reproducible. The model can be widely used in the investigation of pathogenic mechanism for benign airway stenosis and efficacy exploration of new treatment.

    Release date:2019-05-23 04:40 Export PDF Favorites Scan
  • Tranexamic acid inhibits pulmonary inflammatory response induced by cardiopulmonary bypass

    ObjectiveTo investigate the effect of different administration methods of tranexamic acid on postoperative pulmonary inflammation response during cardiopulmonary bypass (CPB).MethodsA total of 64 SD rats were included in the study. They were randomly divided into eight different groups. CPB model was established for the operation groups. The rats in the operation groups were given tranexamic acid at low (25 mg/kg), medium (50 mg/kg) or high (100 mg/kg) concentrations before or after the CPB. Blood cells count and coagulation function were assessed 1 hour after surgery. The concentration of interleukin (IL)-1β、IL-6 and tumor necrosis factor (TNF)-α in blood and lung lavage fluid were measured. The infiltration of inflammatory cells in lungs was observed by hematoxylin-eosin (HE) staining.ResultsThe concentration of inflammatory cells in the operation groups was higher than that in the control group (P<0.05). The use of tranexamic acid inhibited the increase of IL-6 and TNF-α in whole blood and lung lavage fluid due to CPB (P<0.05), but there was no significant difference among the experimental groups (P>0.05). Tranexamic acid could reduce the exudation of inflammatory cells in the lungs.ConclusionThe use of tranexamic acid can effectively reduce the release of inflammatory factors and reduce acute lung injury caused by CPB in rat models. But simply increasing the dose or changing the timing of administration is not more effective in reducing the intensity of the inflammatory response.

    Release date:2020-07-30 02:32 Export PDF Favorites Scan
  • Study on the synchronization of biventricular beats with the control mode of left ventricular assist device

    Right ventricular (RV) failure has become a deadly complication of left ventricular assist device (LVAD) implantation, for which desynchrony in bi-ventricular pulse resulting from a LVAD is among the important factor. This paper investigated how different control modes affect the synchronization of pulse between LV (left ventricular) and RV by numerical method. The numerical results showed that the systolic duration between LV and RV did not significantly differ at baseline (LVAD off and cannula clamped) (48.52% vs. 51.77%, respectively). The systolic period was significantly shorter than the RV systolic period in the continuous-flow mode (LV vs. RV: 24.38% vs. 49.16%) and the LV systolic period at baseline. The LV systolic duration was significantly shorter than the RV systolic duration in the pulse mode (LV vs. RV: 28.38% vs. 50.41%), but longer than the LV systolic duration in the continuous-flow mode. There was no significant difference between the LV and RV systolic periods in the counter-pulse mode (LV vs. RV: 43.13% vs. 49.23%). However, the LV systolic periods was shorter than the no-pump mode and much longer than the continuous-flow mode. Compared with continuous-flow and pulse mode, the reduction in rotational speed (RS) brought out by counter-pulse mode significantly corrected the duration of LV systolic phase. The shortened duration of systolic phase in the continuous-flow mode was corrected as re-synchronization in the counter-pulse mode between LV and RV. Hence, we postulated that the beneficial effects on RV function were due to re-synchronizing of RV and LV contraction. In conclusion, decreased RS delivered during the systolic phase using the counter-pulse mode holds promise for the clinical correction of desynchrony in bi-ventricular pulse resulting from a LVAD and confers a benefit on RV function.

    Release date:2021-04-21 04:23 Export PDF Favorites Scan
  • Air-liquid interface culture of mouse tracheal-bronchial epithelial cells

    ObjectiveTo establish a method of air-liquid interface culture and ciliary beat frequency measurement of mouse tracheal-bronchial epithelial cells to simulate the physiological function of airway epithelium.MethodsBALB/c mouse tracheal-bronchial epithelial cells were obtained by digestion with 1 mg/mL protease in cold temperature overnight, and the digestion time was optimized to ensure the quantity and viability of the obtained cells. After removing fibroblasts by differential velocity adhesion method, the cells were cultured into collagen coated Transwell inserts. Proliferating phase and air-liquid interface culture were promoted with different culture media.ResultsCell numbers obtained by cold protease overnight digestion for 12 h, 14 h and 16 h were (1.78±0.33)×105, (1.93±0.26)×105 and (2.01±0.28)×105, respectively. Cell viability by trypan blue staining were (96.86±0.25)%, (94.73±1.63)% and (86.87±5.95)%, respectively. Cells were 100% confluent in Transwell chamber after 1-week proliferation, and the ciliary beat frequency was observed under microscope after 2 - 3 weeks of air-liquid interface culture. The cilia structure was confirmed by hematoxylin-eosin staining, electron microscopy and immunofluorescence. Ciliary beat frequency of the cells obtained by this method was consistent with that of mouse trachea in vivo, which further demonstrated its capacity in simulating the physiological function of airway epithelium. ConclusionsThe separation and air-liquid interface culture system as well as the ciliary beat frequency measurement method established in this experiment is simple, stable, efficient and reliable, which establishes a substantial foundation for exploring the pathogenesis and treatment mechanism of airway diseases. It can also provide reference for the culture of epithelium in the airway of other species and/or other organs.

    Release date:2019-07-19 02:21 Export PDF Favorites Scan
  • Mid to long-term clinical outcomes improvement through dual antiplatelet therapy after coronary artery bypass grafting: Interpretation of DACAB-FE trial

    Coronary artery bypass grafting (CABG) is one of the most effective revascularization treatments for coronary heart disease. Secondary prevention strategies, which rely on antiplatelet and lipid-lowering drugs, are crucial after CABG to ensure the durability of revascularization treatment effects and prevent adverse cardiovascular and cerebrovascular events in the medium to long term. Previous research conducted by Professor Zhao Qiang's team from Ruijin Hospital of Shanghai Jiao Tong University, known as the DACAB study, indicated that dual antiplatelet therapy (DAPT, specifically ticagrelor+aspirin) after CABG can enhance venous graft patency. However, it remains uncertain whether DAPT can further improve the medium to long-term clinical outcomes of CABG patients. Recently, the team reported the medium to long-term follow-up results of the DACAB study, termed the DACAB-FE study, finding that DAPT administered after CABG can reduce the incidence of major cardiovascular events over five years and improve patients' medium to long-term clinical outcomes. This article will interpret the methodological highlights and significant clinical implications of the DACAB-FE study.

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