Abstract:Objective:To establish the model of human herpesvirus (HHV)-6A subtype latent infection of human glioma cell line U251 in vitro. Methods: U251 cells infected by HHV-6A were cultured and passaged for model establishment. The cell morphology changing, virus replication and viral gene expression were detected to identify the latent infection stage. Results: With increase of HHV-6A infection of U251 cells algebra, the viral gene copy number was gradually decreased to a stable low level. The HHV-6A U94 gene, a representative of the latent stage of infection of the virus, was gradually decreased and then maintained at a stable level. Conclusion: HHV-6A was successfully transferred from the acute infection stage to the latent infection stage in U251 cells in vitro.

Abstract:Objective:To explore the protective effects of small interference RNA (siRNA) targeted interleukin 28 receptor alpha(IL28RA) gene on the hypoxia reoxygenation cardiomyocytes injury. Methods:A complex was designed and synthesized,which consisted of three pairs of siRNA(siRNA-6158,siRNA-6160,siRNA-6162) interfering IL28RA gene expression. Liposome transfection method was used to transfect the siRNA into primary neonatal rat cardiomyocytes. The cells were divided into six groups including the normal control group,hypoxia and reoxygenation group (H/R group),H/R group+negative control transfection group,H/R+siRNA-6158 transfection group,H/R +siRNA-6160 transfection group,and H/R +siRNA-6162 transfection group. The cell survival rate and lactate dehydrogenase (LDH)level in the supernatant were detected. The appropriate transfection concentration was explored. The IL28RA protein expression was observed in the H/R process by using Western blot method. Results:The siRNA of 80 nmol/L is the appropriate transfection concentration. Compared with the H/R group and H/R group+negative control transfection group,the LDH activity in the H/R +siRNA-6158 group and H/R +siRNA-6160 group was significantly decreased(P < 0.05), the survival rate in the both groups was significantly increased(P < 0.05), and the IL28RA protein in the both groups was significantly reduced (P <0.05). Conclusion:Inhibiting IL28RA gene expression was expected to be an important method of protecting anoxic myocardial disease. [Key words] IL28RA; siRNA transfection; hypoxia and reoxygenation; cardiomyocytes; myocardial damage

Abstract:Objective:To study the effects of metformin on oxygen glucose deprivation and reoxygenation (OGD/R)-induced microglial inflammatory reaction. Methods: To establish the OGD/R model of microglia (BV-2 cells), BV-2 cells were pretreated with different concentrations (0.02, 0.20 and 2.00 mmol/L) of metformin, the effective concentration of metformin was determined by MTT and lactate dehydrogenase (LDH) assays. The supernatant of IL-1-茁 was determined by enzyme-linked immunosorbent assay, expressions of nuclear factor kappaB and CD11b were analyzed by Western blot and immunofluorescence,respectively. Results: Metformin (2.00 mmol/L) decreased the release of OGD/R-induced LDH from BV-2 cells and increased MTT activity, reduced the expression of cell surface molecule CD11b, inhibited nuclear translocation of NF-kappaB, and decreased production and release of IL-1-茁. Conclusion: Pretreatment with metformin could reduce OGD/R-induced microglia inflammatory response.

Abstract:Objective:To study the role of G-protein coupled receptor kinase-interacting protein 1 (GIT1) in fracture healing. Methods: GIT1 knockout(KO) mice (n=30) and GIT1 wildtype(WT) mice (n=30) were used to established the femoral model according to our pervious study. Immunohistochemical (IHC) staining was used to detect the endochondral mineralization and the expression of Smad1/5/8 in callus area. Bone marrow mesenchymal stem cells (BMSCs) of GIT1 WT and KO mice were collected and stimulated with 10 ng/mL BMP2,and then the expression of p-Smad1/5/8 and the level of p-Smad1/5/8 translocated into the nuclei of BMSCs were detected. One μg of GIT1-siRNA (or control-siRNA) was co-transfected into C3H10T1/2 cells. Luciferase reporter genes was used to detecte the influence of GIT1 on BMP2 transcription. Results:GIT1 KO mice exhibited delayed fracture healing,chondrocyte accumulation in the fracture area,and reduced staining intensity of phosphorylated Smad1/5/8 (p-Smad1/5/8). BMSCs extracted from GIT1 KO mice showed a decline of p-Smad1/5/8 levels and of p-Smad1/5/8 translocated into the cell nucleus after BMP2 stimulus. The results of luciferase reporter gene assay showed that the level of intracellular GIT1 protein significantly affected the level of BMP2 transcription through p-Smad1/5/8. Conclusion: GIT1 regulates Smad1/5/8 phosphorylation and mediates BMP2 regulation,thus affecting endochondral ossification.

Abstract:Objective:To observe the effects of TLR7 agonist on the immune function of IL-10 transfected bone-marrow derived dendritic cell(mDC). Methods:The IL-10 plasmid was transfected to mouse mDC,and TLR7 agonist,Imiquimod,was added to mDC for 48 h. The expression of MHCⅡ,CD80,CD86,FasL in mDC were detected with flow cytometry,and the production of the IL-6 and TNF-α was detemined by ELISA. Results:IL-10 suppressed the expression of MHCⅡ,CD80,CD86,decreased the production of IL-6 and TNF-α,and increased the expression of FasL on mDC. Imiquimod increased the expression of MHCⅡ,CD80 and CD86,which enhanced the production of IL-6 and TNF-α,but inhibited of FasL expression by the IL-10 transfected mDC. Conclusion:TLR7 activation reverses IL-10 induced low response of mDC.

Abstract:Objective:To observe the effects of fine particulate matter (PM2.5) by different dosages at short-term exposure on airway inflammation in asthmatic mice, and study the mechanisms of PM2.5 on airway inflammation in asthmatic mice. Methods: A total of 40 BALB/c mice were randomly assigned into 5 groups, including the PBS control group, the OVA group (asthma group), the OVA PM2.5 (10 μg) group, the OVA PM2.5 (31.6 μg) group,and the OVA PM2.5 (100 μg) group. Asthma model was reproduced by sensitization with intraperitoneal injection and inhalation of OVA. On day 26, 28 and 30, the mice were performed with PM2.5 intranasal stimulation, and then sacrificed on day 31. We observed the pathological changes and inflammatory cell infiltration by hematoxylin-eosin (HE) staining of lung tissues of mice alveolar fluid (BALF) cells in each group. IL-4/IL-13 and serum IgE levels were examined by the method of ELISA. Results: Compared with the asthma group, the differences in cell count and levels of IL-4/IL-13 were not statistically significant in the PM2.5 (10 μg)/OVA group(P > 0.05), while those in the PM2.5(31.6 μg)/OVA group and the PM2.5(100 μg)/OVA group were increased (P < 0.05). The level of serum IgE in the PM2.5 (10 μg)/OVA group and the PM2.5 (31.6 μg)/OVA group was increased slightly compared with the OVA group, but there was no significant difference(P > 0.05). However, the level of serum IgE in the PM2.5(100 μg)/OVA group was significantly increased than that of the OVA group(P < 0.05). Conclusion: The asthma airway inflammation may further aggravate in the PM2.5(31.6 μg)/OVA and PM2.5 (100 μg)/OVA, and no significant effect was from the PM2.5 (10 μg)/OVA.

Abstract:Objective:To study the effect of vitamin D deficiency on airway inflammation in rats with asthma. Methods:Sixteen Sprague-Dawley rats were divided into 2 groups randomly,including normal control group and vitamin D deficiency experiment model group,with 8 rats in each group. On days 1 and 7,the rats were sensitized with ovalbumin via introperitoneal injection and challenged with daily ovalbumin inhalation for 7 consecutive days since day 14. After the challenge,the bronchial alveolar lavage fluid (BALF) was collected for examining the total cell number and eosinophil count,and the lung tissue was taken to evaluate the airway inflammation. Results:Compared with the control group,the total BALF cell count and eosinophil percentage were found to increase in the vitamin D deficient model group (P < 0.05). More serious pathological changes and asthmatic airway inflammation were found in the lung tissues of rats lack of vitamin D. Conclution:Vitamin D deficiency could give rise to more frequent asthmatic attack and aggravate airway inflammation in asthmatic rats.

Abstract:Objective:To investigate the protective effects of resveratrol against α-naphthylisothiocyanate (ANIT)-induced cholestasis and its relationship with the metabolism of bile acid. Methods:The liver injury model rats with cholestasis were established by using ANIT,and then the protective effects of resveratrol were investigated. In sandwich-cultured rat hepatocytes,the effects of resveratrol on hepatocyte bile excretion and the metabolism of bile acid from cholesterol were investigated. The mRNA levels of enzymes and transporters related to bile acid excretion were determined by Q-PCR. Results: Resveratrol significantly decreased the activity of alanine aminotransferase (ALT),aspartate aminotransferase (AST),the serum content of total bilirubin (TBIL),direct bilirubin (DBIL) and indirect bilirubin (IBIL) in ANIT-induced hepatic injury rat models with cholestasis. In sandwich-cultured rat hepatocytes,resveratrol restored ANIT-induced decrease of biliary excretion index(BEI). It also decreased total bile acid and total bilirubin but increased total cholesterol in ANIT-injured hepatocytes. Data from Q-PCR showed that resveratrol made a recovery of ANIT-induced decrease of Bsep,Mrp2,Ntcp,Cyp7a1 and Cyp8b1 mRNA levels in hepatocytes. Conclusion:Resveratrol exerted protective effects against ANIT-induced liver injury and alleviated the cholestasis. The mechanism may be involved in the regulation of metabolism enzymes and transporters related to bile acid excretion.

Abstract:Objective:This study was conducted to explore whether zinc supplementation improves the disturbance of glucose and lipid metabolism in type 2 diabetes mellitus (T2DM) rats and how did these produce. Methods: T2DM rat model was established by feeding with high-sucrose-fat diet for 8 weeks followed by streptozotocin (STZ) (30 mg/kg, i.p). T2DM rats were randomly divided into four groups. The zinc supplementation groups were respectively administrated 1.6 mg/kg, 3.2 mg/kg and 6.4 mg/kg elemental zinc as zinc sulfate by gavage, while both the normal control group and untreated diabetic group received ultrapure water. After 6 weeks, we detected the indexes about serum zinc, blood glucose, lipid metabolism, oxidative stress and inflammatory cytokines, which including fasting blood glucose (FBG), fasting insulin (FINS), homeostasis model assessment-insulin resistance (HOMA-IR), serum total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), free fatty acids (FFA), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), malonaldehyde (MDA), tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6. The results indicated that zinc supplementation significantly increased serum zinc and HDL-C levels and reduced FBG, FINS, HOMA-IR and serum TC, TG, LDL-C, FFA levels. The activities of antioxidant enzymes were significantly enhanced, while inflammatory cytokines were decreased in the zinc supplementation groups. The high dose of the zinc supplementation group (6.4 mg/kg·d) showed the best curative effects. Conclusion: The present study showed that zinc supplementation could improve metabolic disturbance of type 2 diabetic rats, and that could be related to augmenting antioxidant and anti-inflammatory ability.

Abstract:Objective:To study the effect of isoliquiritigenin on the proliferation of human pancreatic cancer SW1990 cells and survivin expression. Methods: SW1990 cells were treated with different concentrations of isoliquiritigenin and then the cell proliferation was analyzed by MTT. Survivin mRNA and protein expressions were detected with Real-time PCR and Western blot, respectively. Results: In a certain concentration range, isoliquiritigenin significantly inhibited the proliferation of SW1990 cells in a dose- and time-dependent manner. Real-time PCR revealed that isoliquiritigenin down-regulated mRNA expression of survivin in SW1990 cells. The protein expression of survivin was also decreased by isoliquiritigenin treatment. Conclusion: Isoliquiritigenin can inhibit SW1990 cells proliferation and down-regulate survivin expression.

Abstract:Objective:To investigate the effect and mechanism of anesthetic ketamine and morphine on the proliferation of cultured human lung adenocarcinoma A549 cell. Methods:Human lung adenocarcinoma A549 cells were treated with different concentration of ketamine(K1,K2,K3 is 100,200,and 400 μg/mL,respectively)and morphine(M1,M2,M3 is 25,50 and 100 μg/mL,respectively)for 24 and 48 h. After cultured for 24 h,the effect of ketamine and morphine on the invasive ability of A549 cells were measured by transwell invasion. NF-κB transcription activity were determined by luciferase assay. After cultured for 48 h,the proliferation inhibition rates of A549 cells were assessed by methyl thiazolyl tetrazolium (MTT) assay. Protein expressions of NF-κB P65 were determined by Western blot. IL-1β and COX-2 expression were determined by QPCR. Results:(1)Compared with the control group,M1 and M2 enhanced A549 cell proliferation and migration (P < 0.05),while K1,K2 and K3 suppressed A549 cells migration(P < 0.05). (2)M1,M2 and M3 enhanced IL-1β and COX-2 expression(P < 0.05),but K2 and K3 had opposing effects(P < 0.05). M1,M2,and M3 enhanced NF-κB and P65 transcription activity and protein expressions(P < 0.05),while K1,K2 and K3 had opposing effects(P < 0.05). Conclusion:Unlike opioids,ketamine inhibits the proliferation and migration of A549 through NF-κB and its down stream factor IL-1β and COX-2,may be more suitable for lung cancer patients postoperative analgesia.

Abstract:Objective:To learn the anatomic features of the axillary vein in chronic heart failure (CHF) patients and to explore the feasibility and safety of left ventricular lead placement via axillary vein pathway in cardiac resynchronization therapy procedure. Methods: Fifty nine CHF patients (35 male with mean age of 62.32 ± 10.33 years old) underwent CRT or CRTD device implantation from January 2013 to February 2015 were randomly divided into the axillary vein group (n=23) and the subclavian vein group (n=36). The successful rate and time-consuming of the left ventricular lead piacement and related complications were compared. Sixty seven patients (41 male with mean age of 64.34 ± 11.77 years old) underwent dual-chamber pacemaker (DDD) implantation were recruited during the same period for comparison of axillary vein diameter with CHF patients. All patients received axillary venography before procedure. Diameter of the axillary vein was compared between CRT/CRTD patients and DDD patients. Results: All patients successfully implanted the devices. There were no significant differences of axillary vein diameter between the CRT/CRTD group and the DDD group [(10.77 ± 2.19) mm vs. (10.11 ± 2.02) mm, P > 0.05]. The successful implantation time of left ventricular lead was similar between the two groups. No left ventricular lead implantation related complications occurred. There were no significant differences of pacing threshold, sense and impedance of right atrium, right ventricle and left ventricular lead (P > 0.05). Conclusion: The diameter of the axillary vein was normal in chronic heart failure patients. The left ventricular lead placement via the axillary vein is safe and feasible in cardiac resynchronization therapy procedure.

Abstract:Objective:This study was designed to investigate the diagnostic value of serum oxidized low density lipoprotein (oxLDL) for carotid atherosclerotic plaque stability. Methods:From Oct.2013 to Apr.2014,we enrolled 130 patients with carotid atherosclerotic plaque as the study group. All these patients were further divided into the unstable atherosclerotic plaque group and the stable atherosclerotic plaque group according to the results of color Doppler ultrasonography. Meanwhile,120 people receiving physical examination in medical examination room and diagnosed with no carotid atherosclerotic plaque were recruited as the control group. The levels of serum TC,LDL-C and oxLDL were examined in all 250 patients. Results:The difference of serum oxLDL level among three groups was statistically significant (F=213.11,P < 0.001). The level of serum oxLDL was much higher in the unstable atherosclerotic plaque group than that of the stable atherosclerotic plaque group,and was lowest in the control group. The area under ROC curve about oxLDL were 0.863 (P < 0.01). Conclusion:The level of serum oxLDL has the diagnostic value for the stability of carotid atherosclerotic plaque.

Abstract:Objective:To investigate the expression of serum miR-29c in the patients with non-proliferating diabetic retinopathy (NPDR) and explore the role of miR-29c in diabetic retinopathy (DR). Methods: Patients with NPDR (n=30) and without DR (n=30) were enrolled. Total RNAs including miRNA was extracted from serum samples. The levels of miR-29c were detected by quantitative Real-time PCR. PicTar, TargetScan and MiRanda were performed to comprehensively predict target genes of miR-29c, and the intersection of the three softwares was set as the final target genes. Results: The expression of serum miR-29c was significantly elevated in the NPDR group than that in the NDR group (P < 0.05). Positive correlation between miR-29c expression and HbA1c level (r=0.379, P < 0.05) was observed. The target genes of miR-29c were significantly enriched in inositol phosphate metabolism, interaction between cytokine and cytokine receptor, and ECM and receptor. Conclusion: The serum levels of miR-29c were significantly increased in the NPDR group. MiR-29c may play an important role in pathogenesis of DR by regulating cytokines interaction and inositol phosphate metabolism.

Abstract:Objective: To detect the expression of Rab27b in human colorectal cancer (CRC) and investigate the relationship between Rab27b expression and clinical characteristics, especially the prognosis of CRC. Methods: Immunohistochemistry analysis by tissue microarrays (80 CRC samples and 20 tumor-adjacent tissue samples) was performed to characterize Rab27b expression in CRC. Cox regression and Kaplan-Meier survival analyses were carried out to evaluate the prognosis of CRC. Results: Immunohistochemistry analysis showed that the expression of Rab27b in CRC was significantly higher than that in normal tumor-adjacent tissues (P = 0.041). Moreover, the expression level of Rab27b protein in CRC was significantly related to gender (P = 0.012), serum CEA level (P = 0.014), distant metastasis (P = 0.021) and TNM stage (P = 0.013). COX multi-factor analysis showed that Rab27b expression (P = 0.021) could be recognized as an independent prognosis factor for CRC. Conclusion: Rab27b expression was abnormally highly expressed and correlated with malignant phenotypes of CRC. It may serve as a novel prognostic factor for CRC.

Abstract:Objective:To determine the association of plasma brain natriuretic peptide (BNP) level and left ventricular remodeling in patients with maintenance haemodialysis (MHD) and to evaluate the risk factors for increased BNP levels in this population. Methods: We measured the left ventricular diastolic dimension (LVDD), interventricular septal thickness (IVST), left ventricular posterior wall thickness (PWT), according to ratio of early to late left ventricular filling velocity (Ve/Va) by tissue Doppler imaging in 85 patients with MHD. The patients were divided into two groups: left ventricular diastolic dysfunction (Ve/Va<1,n=36) and without left ventricular diastolic dysfunction (Ve/Va≥1, n=49). Plasma high sensitivity C-reactive protein (hs-CRP), parathyroid hormone (PTH) and BNP levels were determined from medical records. Results: Plasma BNP levels were significantly higher in patients with left ventricular diastolic dysfunction than in those without left ventricular diastolic dysfunction (P < 0.01). The area under the receiver-operating characteristic curve for BNP to detect left ventricular diastolic dysfunction was 0.724 (95% CI: 0.606-0.842, P < 0.001). According to LVDD, LVST and PWT, patients were further divided into three groups: the left ventricle with normal structure group, left ventricle with concentric hypertrophy group, and the left ventricle with eccentric hypertrophy group. Plasma BNP levels had significantly positive correlation with systolic blood pressure, pulse pressure, IVST, and PWT. Stepwise multiple regression analysis further revealed that SBP, IVST and PWT were independent risk factors for increased BNP levels (F=3.217, P=0.028). Conclusion: Plasma BNP level is significantly higher in MHD patients with left ventricular concentric hypertrophy and may be a biomarker for assessing left ventricular function. SBP, IVST and PWT are independent risk factors for increased BNP level.

Abstract:Objective:To investigate the level of CCL5 in patients with systemic lupus erythematosus (SLE), and to analyze the relationship between CCL5 expression, SLE disease activity and organ involvement. Methods: The plasma levels of CCL5 were measured by enzyme-linked immunosorbent assay (ELISA) in 31 SLE patients and 16 healthy people. Of the 31 SLE patients, according to renal involvement, there were 21 cases of lupus nephritis and 10 cases of SLE without renal involvement. CCL5 level was detected by enzyme-linked immunosorbent assay (ELISA), and its relationship with SLE clinical parameters was analyzed. Results: The expression of CCL5 was significantly increased in the SLE group compared with that of the normal controls. The expression level of CCL5 was significantly higher in the lupus nephritis group than that of the no kidney involvement group and the healthy control group. The expression level of CCL5 was positive correlated to SLE disease activity index (DAI) (r=0.54). Conclusion: Chemokine CCL5 may play a key role in the pathogenesis of SLE, including the renal involvement. CCL5 is also a serological marker of disease activity in patients with SLE.

Abstract:Objective:We aimed to explore sensitive serum biomarkers for the early evaluation of the occurrence and severity of bronchopulmonary dysplasia (BPD)by investigating the correlation between BPD and serum biomarkers including serum soluble receptor for advanced glycation end products (sRAGE)-endogenous secretory receptor for advanced glycation end products(esRAGE)-surfactant protein D(SP-D)and Clara cell 16 KD protein(CC-16)in the very low birth weight infants(VLBW). Methods The levels of sRAGE,esRAGE,SP-D and CC-16 in serum in 60 VLBW infants were detected by ELISA within 48 hours after birth.Meanwhile,we recorded their occurrence and valued the severity of BPD.Then we used statistical methods to analyze the correlation between serum biomarkers and the incidence and degree of BPD. Results:Compared with the normal control group,the levels of serum sRAGE and esRAGE increased significantly(P < 0.01)in the BPD group,while there was no significant difference in SP-D and CC-16 levels (P > 0.05).Additionally,the serum levels of sRAGE and esRAGE also showed statistic significance among the mild,moderate and severe BPD groups. Serum levels of sRAGE and esRAGE were not associated with gestational age. Conclusion:Serum levels of sRAGE and esRAGE can be early serum biomarkers for the occurrence and severity of BPD in VLBW infants.

Abstract:Objective:To explore the epidemiology of human rhinovirus (HRV) infection in children with acute low respiratory tract infection and its relationship with meteorological conditions in Suzhou. Methods: A total of 1 926 children with acute low respiratory tract infection were participated in the trial during January to December 2013,and the nasopharyngeal aspirates were collected for HRV detection with real time PCR. Meanwhile meteorological conditions including mean temperature, relative humidity, total month rainfall, sum of sunshine, and mean wind velocity were collected monthly during the same period. The relationship between the epidemic of HRV and meteorological conditions were analyzed by Spearman rank correlation analysis. Results: HRV was identified in 11.1% of 1 926 specimens,81.3% patients with HRV infection were younger than 3 years old;The prevalence of acute HRV infection was higher during summer and spring. HRV detection rate was positively correlated with the monthly mean temperature. Conclusion: HRV is a common pathogen in hospitalized children with lower respiratory tract infection in Suzhou. Meteorological factor,especially temperature may affect the prevalence of HRV.

Abstract:Objective:To explore and compare the results of the treatment of hypertrophic nonunion of limb fractures by using extracorporeal shock wave therapy (ESWT) or traditional iliac autograft and internal fixation. Method: A prospective randomized control study was designed. A total of 72 patients were recruited from June 2012 to June 2013 according to inclusion-exclusion criteria, and randomly divided into two groups. Group A referred to using ESWT with 39 cases for 3 times with interval of 7 days, while 33 cases in Group B treated with traditional iliac autograft and internal fixation. The baseline of the two groups had no significant difference (P > 0.05). Mean follow-up was 18.2 months. The appearance time of callus, the final healing time of fractures, the cost of treatments and postoperative complications were record. Results: No significant difference was found in the final cure rates of the two groups (P > 0.05). Group B presented earlier in the appearance time of callus (P < 0.05), however, the final healing time of fractures showed no significant difference between the two groups (P > 0.05). Group B showed higher cost of treatment(P < 0.05). Conclusion: Treatment of hypertrophic nonunion of fractures by ESWT is safe and effective with advantages of minimal invasive, high cure rate, low expense and less complications. ESWT is suggested to be used for the hypertrophic nonunion patients before traditional iliac autograft and internal fixation.

Abstract:Objective: To assess the effects of a closed-loop implanted chip system on heart rate regulation in conscious rabbits. Methods: Twelve rabbits with normal heart rate (HR) were randomly divided into the control and the vagus nerve stimulation (VNS) groups. In the VNS group, all the animals were implanted the self-developed closed-loop chip for a week. The right vagus nerve of rabbit was randomly stimulated by the chip according to real-time feedback of HR at different times. Each rabbit underwent 1 hour of regulation and 1 hour of recovery. The control group was implanted the chip without any stimulation. MD2000WL software recorded the real-time electrocardiogram (ECG). HR was calculated by the chip according to the ECG. Results: The implanted closed-loop chip system worked well in conscious rabbits in vivo. The chip recorded complete ECG. There was a significant decrease of HR during the regulation [(265.2 ± 15.2) bpm vs. (289.5 ± 15.7) bpm, P < 0.05] compared with the baseline HR in the VNS group. The HR was also significantly decreased during regulation in the VNS group [(-24.3 ± 3.6) bpm vs. (-4.6 ± 5.1) bpm, P < 0.05] compared with the control group. Conclusion: The implanted closed-loop chip system can successfully regulate the heart rate of conscious rabbits in long term.

Abstract:Objective:The aim of the study was to determine the position of ligation and control infarct size in the establishing of a rat myocardial infarction model (MI). Methods:Experimental group models (n=58) were produced by the ligation of left anterior descending coronary artery in left ventricular peak point along a line connecting the insertion of the left auricular appendage with the apex of the heart. MI control group (n=38) was produced by using the conventional method. Triphenyltetrazolium chloride (TTC) staining was performed to compare infarct size (IS,%) in two groups,and electrocardiogram (ECG) and echocardiography changes were observed also. Results:ECG monitoring showed that the success rate of the experimental group was significantly higher than that of the control group (88.9% vs 65.5%,P< 0.05). Moreover,there were 40 rats had medium-size infarction among experimental group detected by TTC. In contrast,only 11 rats had medium-size infarction among control group. It did differ significantly among rats with medium MI (P < 0.01). Conclusion:Accurately identify anterior descending coronary artery ligation site could help control the myocardial infarct size and improve the success rate of establishing myocardial infarction model.

Abstract:Objective:We aimed to assess the left atrial (LA) myocardial function using two-dimensional (2D) speckle tracking echocardiography (STE) in hypertension patients with preserved LV ejection fraction and to explore the relationship between LV remodeling and LA function. Methods:The routing 2D echocardiography data sets were acquired of 102 hypertensive patients and 102 age and gender matched normal subjects. Preatrial contraction volume (LAVpreA), minimal LA volume (LAVmin) and maximal LA volume(LAVmax) were measured. LA EF[(LAVmax-LAVmin)/LAVmax],passive[(LAVmax-LAVpreA)/LAVmax] and active empty EF[(LAVpreA-LAVmin)/LAVpreA]were calculated. The LA strain during systole,early and late diastole(εs,εa and εe=εs-εa); srtrain rate(SRs,SRe and SRa) and velocity(Vs,Ve and Va) were analyzed by GE EchoPAC. Results:Global LA εs,εe,and εa,SRs,SRe and SRa as well as Vs,Ve and Va were significantly lower in patients than control group (P < 0.000 1,except εa,which the P was 0.006). The LAVmax,LAVpreA,LAVmin were significantly higher in patients than controls (P < 0.000 1),and empty EF was statistically lower in patients than normal (P < 0.05). The global LA 2DSTE parameters were significantly correlated with LA volumes and empty EF,which represented LA function. The global LA Ve/Va was significantly correlated LV mass index(r=-0.39,P < 0.000 1). Conclusion:Our results indicated that the LA volumes were increased and functions were decreased,which were related with LV remodeling in patients with hypertension.