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【Objective】 To explore the effects of insulin on the QT interval and induced arrhythmias of cardiomyocytes derived from human induced pluripotent stem cells （hiPSC-CMs）. 【Methods】 Immunofluorescence staining and flow cytometry were used to analyze the purity of hiPSC-CMs. Microelectrode array （MEA） was utilized to detect the electrophysiological changes including heart rate （HR）， field potential duration （FPD， which is similar to QT interval in ECG）， FPDc （FPD corrected by HR）， conduction velocity （CV）， and spike amplitude before and after insulin treatment. The effects of E4031 on QT interval prolongation and induced arrhythmias of hiPSC-CMs were evaluated before and after treatment with insulin. 【Results】 hiPSC-CMs highly expressed myocardial specific marker cTnT. The purity of hiPSC-CMs was 97.1%. After 5-day insulin treatment of hiPSC-CMs， HR increased by （11.9±3.3）%， FPD shortened by （22.7±2.8）%， FPDc shortened by （15.6±1.6）%， and spike amplitude increased by （39.1±7.9）% when compared with untreated group， but CV remained unchanged. 10 nmol/L of E4031 could prolong the FPDc of hiPSC-CMs by （37.8±9.0）%， and 30 nmol/L of E4031 could induce arrhythmias. After insulin treatment， 10 nmol/L of E4031 prolonged the FPDc of hiPSC-CMs by （21.8±3.1）% （compared with the untreated group， insulin decreased FPDc prolongation by E4031， 37.8%±9.0% vs. 21.8%±3.1%， P<0.05）， while 30 nmol/L of E4031 did not induce arrhythmias. 【Conclusion】 Insulin can shorten the QT interval of hiPSC-CMs and significantly reduce the QT interval prolongation and the risk of arrhythmias induced by drugs.
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【Objective】 To explore the effect of bisoprolol on ICa，Lin volume overload combined with pressure overload heart failure in rabbits. 【Methods】 Totally 82 male New Zealand rabbits （2.5-3.0 kg） were randomly divided into three groups： SO （sham group）， HF （heart failure group）， and BF （heart failure with bisoprolol treatment group）. HF rabbits were duplicated by aortic valve insufficiency procedure combined with abdominal aorta constriction procedure. Real-time PCR and Western blot analysis were performed to detect the expression of ICa，L in left ventricular myocytes. Left ventricular myocytes were isolated； then the cell membrane capacitance， the current density， activation and inactivation of ICa，L were recorded by whole cell patch clamp. 【Results】 ① Bisoprolol could improve the heart function of heart failure rabbits according to the measurement of echocardiography and BNP. ② The expressions of ICa，L mRNA and protein decreased significantly in heart failing rabbits （P<0.01）， but remained unaltered after chronic bisoprolol treatment （P>0.05）. ③ Membrane capacitance was larger in heart failing groups than in sham group （P<0.01）. ICa，L current density decreased greatly in HF group （P<0.01）. Bisoprolol treatment could not change Cm or ICa，L density （P>0.05）. V1/2 of activation curve negative shift enlarged window currents in heart failure groups. Bisoprolol treatment caused window currents to decrease. 【Conclusion】 Bisoprolol could reverse the heart function of heart failure rabbits and also affect the function of ICa，L.
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10.3969/j.issn.2095-4344.2013.23.001
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Objective We performed experiments using Neuregulin-1β (NRG-1β) treatment to determine a mechanism for the protective role derived from its beneficial effects by remodeling gap junctions (GJs) during heart failure (HF). Methods Rat models of HF were established by aortocaval fistula. Forty-eight rats were divided randomly into the HF (HF, n = 16), NRG-1β treatment (NRG, n = 16), and sham operation (S, n = 16) group. The rats in the NRG group were administered NRG-1β (10 μg/kg per day) for 7 days via the tail vein, whereas the other groups were injected with the same doses of saline. Twelve weeks after operation, Connexin 43 (Cx43) expression in single myocytes obtained from the left ventricle was determined by immunocytochemistry. Total protein was extracted from frozen left ventricular tissues for immunoblotting assay, and the ultrastructure of myocytes was observed by transmission electron microscopy. Results Compared with the HF group, the cardiac function of rats in the NRG group was markedly improved, irregular distribution and deceased Cx43 expression were relieved. The ultrastructure of myocytes was seriously damaged in HF rats, and NRG-1β reduced these pathological damages. Conclusions Short-term NRG-1β treatment can rescue pump failure in experimental models of volume overload-induced HF, which is related to the recovery of GJs structure and the improvement of Cx43 expression.
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ObjectiveTo study the clinical value and efficacy of intracranial hemorrhage smashpuncture needle with YL-1 type disposable under CT monitoring in treatment of hypertensive intracerebral hemorrhage.MethodsThe data of 80 cases with hypertensive intracerebral hemorrhage patients who accepted the transcranial puncture under CT monitoring application of YL-1 type disposable intracranial hemorrhage smash puncture needle and drainage of hemorrhage,punctuated with urokinase washout and drainaged residual blood clot.Evaluation criteria:hemorrhage volume reduction,average operation time,preoperative and postoperative Glasgow coma scale(GCS) score,the clinical effect of long-term follow-up.ResultsOperation time was 15-45 (25.0 ± 2.8) minutes;hemorrhage volume was reduced by an average of 30％-80％ (56.8 ± 3.2)％,the average increase of GCS was(2.3 ±0.3) scores,10 cases death in 80 patients,70 survivors' activities of daily living (ADL) assessments:grade ADL 1 in 17 cases ( 24.3 ％ ),grade ADL2 in 36 cases( 51.4％ ),grade ADL3 in 13 cases ( 18.6％ ),grade ADL4 in 3 cases(4.3％ ),grade ADL5 in 1 case ( 1.4％ ).ConclusionsYL-1 type disposable intracranial hemorrhage smash puncture needle under CT monitoring in the treatment of hypertensive intracerebral hemorrhage is a simple,fast and accurate positioning,without craniotomy and blood transfusion,safe and effective operation,but should pay attention to operation indications.
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BACKGROUND: It is conceivable that bone marrow stem cells can differentiate into smooth muscle cells (SMCs) and contribute to neointimal formation in atherogenesis. However, the mechanism remains unknown. The "milieu-induced-differentiation" hypothesis focuses on the key role of cell-to-cell contact and cytokine on the differentiation of stem cells. Bone marrow mesenchymal stem cells (MSCs) have the potential to differentiate into SMCs.OBJECTIVE: To induce MSCs into SMCs in vitro, and investigate the influence of the differentiated SMCs or cell factors on MSCs differentiation.DESIGN: Controlled experiment in vitro with repeated observation and measurement based on cells.SETTING: Department of Cardiology, First Hospital of Xi'an Jiaotong University.MATERIALS: The experiment was accomplished in the Laboratory of Cardiology, First Hospital of Xi'an Jiaotong University between May 2003 and May 2004. SD rats of either gender were provided by the Animal Center of Xi'an Jiao Tong University, 60-80 g, 90-110 g. The following antibodies were used: Mouse anti human SM-α-actin (NeoMarkers),Mouse anti human Calponin (NeoMarkers), TRITC-coupled goat anti mouse IgG antibody (SBA). Mouse anti rat CD34 conjugated FITC (Santa Cruz), Mouse anti rat CD71 conjugated FITC (Oxford Biotechnology), Mouse anti rat anti-CD90 conjugated PE (Oxford Biotechnology). Lipofectamine 2000 (Invitrogen). PEGFP-N3 (the laboratory).METHODS: Bone marrow mesenchymal stem cells were obtained from rat bone marrow by using percoll density gradient centrifugation. SMCs were isolated by using tissue explantation method. Flow cytometer was used to detect the immunofluorescence stain. Then MSCs and SMCs were identified. MSCs were transfected with pEGFP-N3 by Lipofectamine 2000, while untransfected MSCs were taken as controls. Conditioned culture of MSCs and SMCs: ①MSCs at passage 3 were seeded on chamber slides in a 12-well culture plate. The medium was DMEM containing 0%, 5%,7.5% fetal bovine serum (FBS) and SMCs conditioned medium containing 0%, 5%, 7.5% FBS, respectively. The cells were cultured for 10-14 days and immunofluorescence analysis was performed by using monoclonal antibodies against SM-α-actin, calponin.②Indirect co-culture of MSCs with SMCs were established using a semi-permeable membrane cell culture insert. The inserts were plated into culture well. SMCs were cultured on the inside of inserts while MSCs were added to the outside of inserts, respectively. MSCs were culture alone in medium containing 3%, 7.5% FBS and immunofluorescence analysis was performed by using monoclonal antibodies against SM-α-actin, calponin.③MSCs were transfected with pEGFP-N3. After 24 hours, the MSCs were cocultivated with SMCs at an equal density for 7-14 days.As a control, MSCs were cultured alone. MSCs co-cultured were stained with antibodies against calponin, SM-α-actin. MAIN OUTCOME MEASURES: ①Identification of MSCs by floe cytometer.②cytoplasmic antigen expression of SMCs. RESULTS: ①Immunofluorescence analysis showed that MSCs expressed SM-α-actin, but did not express calponin. As a control, SMCs expressed both SM-α-actin and calponin.②Flow cytometry showed that MSCs expressed CD71 of low level, CD90 of high level and no expression of CD34. ③The MSCs transfected with green fluorescence protein continued to express for 2-3 weeks. ④MSCs grew well in SMCs conditioned medium or different concentrations of FBS. Cell growth was FBS concentration dependent in indirect co-culture system of MSCs and SMCs. Several double-positive cells in direct co-culture system were detected enhanced green fluorescence protein and antibodies against calponin, SM-α-actin. CONCLUSION: ①SMCs conditioned medium and cell factor only promote MSCs growth and cytoplasmic granules increase. But these do not induce MSCs differentiate into SMCs. ②The cell-to-cell contact is essential for MSCs differentiation to SMCs.
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Objective To determine the optimal condition for labeling rat bone marrow mesenchymal stem cells(MSCs) with green fluorescent protein(GFP)infection by lentiviral vector so as to establish a subgroup of MSCs which have a high level of GFP expression.Methods MSCs were infected with GFP by lentiviral vector for 12h or 24h at different MOI(25,50,100,200 and 400).The infection efficiency and fluorescence intensity were analyzed by inverted fluorescent microscopy and flow cytometry.The effect of infection at different MOI on proliferation of MSCs was evaluated by MTT.Based on those mentioned above,we could determine the optimal condition for infection.Then single cell clones of MSCs labeled with GFP under optimal condition were selected by using cloning rings.Results The efficiency of infection for 24h at MOI 100,200 and 400 was 88.94%,99.65% and 99.42%,respectively.The infection had no significant effect on the proliferation of MSCs infected at MOI 100 or 200,compared with MSCs without infection.However,those MSCs infected at MOI 400 proliferated slowly.The rate of GFP expression on single-cell clone of MSCs infected for 24h at MOI 200 was 99.95%,and their fluorescence intensity was strong and uniform.Conclusion Infection for 24h at MOI 200 is optimal for labeling rat bone marrow MSCs with GFP by a lentiviral vector.A subgroup of MSCs which have a stably high level of GFP expression can be obtained by single cell cloning technique.
