AIM: To elucidate the effects of losartan on the expression ofmatrix metalloproteinases-2, JNK1/2 and proliferation in cardiac fibroblast. METHODS: Neonatal rat cardiac fibroblasts were cultured. The cells proliferation was determined by MTT. To determine effects of AngⅡ on JNK1/2 activity, cells were incubated (for 0, 2, 5, 10, 30, 60, 120 min) in serum-freemedia with AngⅡ, and the other group fibroblasts were exposed to serum-free media with or without AngⅡ and losartan (AngⅡ 100 nmol/L, AngⅡ 100 nmol/L+losartan 100 nmol/L, losartan100 nmol/L, losartan for 45 min before). Cells protein was collected with MBST buffer. The relative abundance of MMP-2, JNK1/2 and p-JNK1/2 in cells was determined by immunoblotting. The secretion of MMP-2 in media of cell culture was determined by ELISA. RESULTS: AngⅡ increased the proliferation of CFB in a dose-dependent manner, whereas losartan decreased the proliferation of CFB stimulated by AngⅡ in a dose-dependant manner, too (P＜0.05). The relative abundance of JNK1/2 was highest in AngⅡ of the 2-min-stimulated group. AngⅡincreased expression of JNK1/2 and MMP-2 protein (P＜0.05), on the contrary, losartan inhibited JNK1/2 and MMP-2 protein expression.CONCLUSION: AngⅡ induce the increase of proliferation of CFB, expression of JNK1/2 and MMP-2 in CFB, and losartan inhibits these effects of AngⅡ.

Objective To assess the clinical features and treatment of children with long QT syndrome (LQTS)and syncope.Methods Eleven cases of children with LQTS and syncope between January 2009 and July 2014 in Hunan Children′s Hospital were retrospectively analyzed for clinical features,treatment and long term follow -up.Results There were 11 cases of children with LQTS aged 4.0 -14.5(9.16 ±2.71)years,8 male and 3 female, with syncope more than once.The range of QTc was 460 -521(483.72 ±22.90)ms.For 3 cases of acquired LQTS,1 case was parathyroid hypothyroidism causing hypocalcemia,1 case was myocarditis complicated with third degree atrio-ventricular block,and 1 case showed atrial flutter receiving amiodarone post congenital cardiac surgery.All patients re-covered after the inducement removed and primary illness cured.For 8 cases of congenital LQTS,3 cases of LQTS un-derwent genetic test (1 case of KCNQ1 gene mutation,2 cases of KCNH2 gene mutation).One case died after frequent torsade de pointes (Tdp)and ventricular fibrillation during hospitalization,the remaining 7 patients were given oral pro-pranolol,potassium chloride sustained -release tablets after discharge.Follow -up time was 8 to 75 months,an average of (45.73 ±24.42)months.One case died suddenly at home after 25 months of follow -up.The remaining 6 cases of children with congenital LQTS could withstand general activities without syncope,in which 4 cases had normal QTc by electrocardiography(ECG),and the findings in 2 cases did not change compared with those previously.The QTc re-turned to normal in children with acquired LQTS in the follow -up review.Conclusions Children with congenital LQTS should receive early genetic screening and genotyping for rational use of drugs.For children with higher risk of sudden death,drug therapy combined with implantable cardioverter defibrillator should be considered.For acquired LQTS,it should be better to remove the inducement and treat primary disease actively.

Objective To assess the clinical short-term to mid-term efficacy of transcatheter closure of coronary artery fistula by using patent ductus arteriosus occluder in pediatric patients. Methods During the period from Jan. 2008 to May 2013 at authors’ hospital, transcatheter closure of coronary artery fistula using patent ductus arteriosus occluder was performed in 8 pediatric patients. The clinical data, including follow-up information, were retrospectively analyzed. Results A total of 8 pediatric patients with a mean age of (4.1 ± 3.8) years were enrolled in this study. The fistula originated from the right coronary artery in five cases and from the left coronary artery in three cases. The blood flow shunted to the right atrium (n=4) or to the right ventricle (n = 4). Obstruction of the fistula was successfully accomplished in all patients. All patients were followed up for (2.2 ± 1.2) years. No procedure-related complications or cardiac ischemia occurred. Conclusion For the treatment of coronary artery fistula in pediatric patients, the use of domestic patent ductus arteriosus occluder is safe and effective with satisfactory short-term to mid-term clinical efficacy.

Objective To assess the adhesive behavior of dual-targeted microbubbles carrying both Sialyl Lewisx and anti-ICAM-1 monoclonal antibodies in vitro. Methods Selectin-targeted (with Sialyl Lewisx) microbubbles (MB-S),ICAM-1-targeted (with anti-ICAM-1 monoclonal antibodies) microbubbles (MB-Ⅰ),and dual-targeted (with both ligands) microbubbles(MB-D) were prepared by attaching the ligands to the biotinylated lipid-microbubbles via multi-step avidin biotin bridging chemistry. A parallel plate flow chamber combined with a novel automated tracking algorithm,were used to analyze the transient velocities,rolling and firmly adherent numbers of microbubbles at various shear stress (0. 6,2.0 and 4.0 dyn/cm2)over 6 min. Microbubbles detachments were tested by ramping up the shear stress at 30 s intervals. Results At 0.6 dyn/cm2 shear stress, the rolling numbers of MB-S and MB-D were remarkably more than that of MB-I( P＜0.05), while at 2.0 and 4.0 dyn/cm2 MB-S performed higher rolling efficiency as compared with either MB-I and MB-D ( P＜ 0.05). In all flow conditions, the adhesive numbers of MB-D to the targets were obviously greater than those of MB-S and MB-I ( P＜ 0.05). Half-maximal detachment decreased gradually in MB-I, MB-D and MB-S by turns ( P＜ 0.05). Conclusions MB-I, MB-S and MB-D have different adhesive behaviors. MB-I exhibites primarily firm adhesion with low rolling efficiency, while MB-S reveales unstable or transient adhesion with high rolling efficiency,and MB-D exhibites firm adhesion with high rolling efficiency. MB-D may be suitable for molecular imaging in high-flow vessels.

Objective To compare the efficacy and safety of the non-invasive high frequency ventilation (NHFV) and non-invasive intermittent positive pressure ventilation (NIPPV)in neonates with respiratory distress syndrome (RDS) after extubation.Method Neonates with RDS from January 2015 to January 2016,who required high frequency ventilation after birth and were extubated after treatment were retrospectively studied.The enrolled patients were divided into NHFV group and NIPPV group to compare the rate of successful extubation within 7 days,non-invasive respiratory ventilation support time and complication incidence.Result In total 42 neonates were included,NHFV group were 21 cases and NIPPV group were 21 cases.The rates of successful extubation were not statistically different (71.4％ vs.80.9％,P ＞ 0.05);Compared with NIPPV group,NHFV group had shorter ventilation time [3.5 (2.2,4.1) d vs.4.6 (2.8,5.3)];the incidence of bronchopulmonary dysplasia,pneumothorax,intraventricular hemorrhage,periventricular leukomalacia,retinopathy of premature and necrotizing enterocolitis between groups were not statistically different (P ＞ 0.05).Conclusion NHFV is a new safe and efficient ventilation support method for extubated neonates,and needs further research.

Objectives To assess treatment outcomes and prognosis in infants with atrial flutter (AFL).Methods Thirty-four (34) cases of infants with AFL in Hunan Children's Hospital had been analyzed for clinical features, treatment outcomes and follow-up between March, 2009 and September, 2015. Based on ECG characteristics, the patients had been divided into simple and complex AFL groups. Based on age, they had been divided into neonates and non-neonates group. The aim of this study is to compare the clinical effects of drug treatment in different types of AFL.Resultsb With digitalis alone, the cardioversion rate was 37.5%,no signiflcant difference was observed between simple and complex AFL groups (45.8% vs 12.5%,P=0.206). Combining with other drugs, the cardioversion rate was 54.5%, which showed signiflcant difference between simple and complex AFL groups (76.9% vs 22.2%,P=0.036). The overall cardioversion rate was 70.6%, which showed signiflcant difference between simple and complex AFL groups(87.5% vs 30%,P=0.003). There was no signiflcant difference in pharmaceutical cardioversion rate between neonates and non-neonates group (85.7% vs 60.0%,P=0.216). Two cases with symptoms of heart failure used synchronized cardioversion. One patient restored to sinus rhythm, and another case was still recurrent of AFL after repeated electrical cardioversion, and eventually died of cardiogenic shock. After treatment, 9 patients were still with paroxysmal AFL and atrial tachycardia episodes, including 3 cases of simple type and 6 cases of complex type who were discharged with oral digoxin and propafenone treatment at home. 24 patients were followed up (3 months to 3 years and 4 months). 16 cases restored to sinus rhythm during hospitalization had no recurrence of AFL.Conclusions The overall treatment effects of AFL in infants were good. In simple type of AFL, most of patients did not need long-term antiarrhythmic drug therapy and the prognosis was good. The prognosis of treatment with conventional drug was poor in complex AFL group, with a higher rate of recurrence of AFL.

Objective To develop nanometer-scale bubbles with surfaces of N-palmitoyl chitosan(PLCS) as ultrasound contrast agent and evaluate its characteristics and acoustic effects in vivo. Methods The PLCS nanobubbles were prepared using a cutting technique at differential high-frequency of shear speed. Both optical and transmission electron micrography were performed to determine the nanobubble size and morphology. Concentration, size-distribution and zeta potential of the PLCS nanobubbles were measured by cell counting chamber, Malvern lazer particle analyzer and zeta-sizer at 1-day, 45-day and 90-day. The acoustic effects of the PLCS nanobubbles on myocardium and renal tissue in 6 normal rats were observed using bolus infusion of the nanobubbles intravenously. The maximum video intensity(VI) was measured.Results The PLCS nanobubbles with nice round-shape and uniform site-distribution were demonstrated.The mean diameter,concentration and zeta potential of the PLCS nanobubbles were (617 ± 12) nm, (7.2 ±0.6) × 109/ml and (52.9 ± 1.3)mV at the 1-day,and all of parameters did not change significantly in 45-day and 90-day ( P ＞ 0. 05). A significant contrast-enhancement was noted on myocardium and renal tissue during infusion of the nanobubbles. VI on both tissues was (15.6 ± 1.1)GU and (27.3 ± 2.5)GU,respectively. The visual contrast-enhancement last up to (10 ± 2)min. Conclusions The PLCS nanometerscale bubbles have excellent physical-features and contrast-enhanced ultrasound effects in vivo. It may develop as a novel contrast ultrasound agent which could cross endothelial cell membrances.

Objective To explore the feasibility of visually assessment of angiogenesis in a murine model of subcutaneous matrigel plugs with ultrasound molecular imaging(UMI) using microbubbles(MB)targeted to endothelial αv-integrins. Methods Matrigel angiogenesis was created by subcutaneous implantation of FGF-2 enriched matrigel in 10 mice. On day 10, UMI of the matrigel was performed in all mice at 6 minutes after intravenous injection of either αv-integrin targeting microbubbles(MBα) or isotype control microbubbles(MBc) in random with 30 min interval,and the video intensity(Ⅵ) was measured. To further test the specificity of the signal coming from MBα,antibody against αv-integrin was injected 10 min before microbubbles injection. Following UMI,all matrigels were harvested for histological analysis. Results As expected,VI of the matrigel was significantly higher ( P ＜0.05) for MBα (20. 5 ± 3.3)U as compared with MBc (4. 8 ± 1.5)U. After blocking with antibody against αv-integrin,a great decrease was observed in the MBα group [VI (4.6 ± 1.2) U, P ＜0.05] while no significant difference was noted for MBc [VI (4. 9 ±1.5)U, P ＞ 0.05 ]. Neovessels within matrigel was positive for αv-integrin. Conclusions UMI with microbubbles targeted to αv-integrins can be effective and specific in evaluating the angiogenesis in a murine model of subcutaneous matrigel plugs.

Objective To assess the binding capability of microbubbles targeted to VCAM-1 using the parallel plate flow chamber mimic the pulsatile high-shear flow conditions of artery. Methods Targeted microbubbles were designed by conjugating monoclonal antibodies against mouse VCAM-1 to the lipid shell of the microbubbles via an "avidin-biotin" bridge. The binding and retention of targeted microbubbles to VCAM-1 (MBv) immobilized on a culture dish were assessed in a flow chamber at variable shear stress (0.5～ 16.0 dynes/cm2 ). The pulsatile flow conditions were generated and compared to the continuous flow conditions. The retentive ability of MBv was evaluated by the detachment test. Results The marked binding of MBv were seen in pulsatile and continuous flow conditions at low-shear flow conditions of 0.5 ～ 2dyn/cm2 ,but the binding rate in the pulsatile flow group was higher ( P ＜0. 05) than that in the continuous flow conditions. Furthermore,the marked binding of MBv was still noted at the highest shear rates (4～8dyn/cm2) under pulsatile flow conditions, while it was not observed under continuous flow conditions. The half detachment rate of MBv was high up to (20.7 ± 3. 1)dyn/cm2. Conclusions The targeted microbubbles binding to VCAM-1 specific and effective at high-shear stress under pulsatile flow conditions. The molecular ultrasound imaging can be potentially used in the high-shear conditions artery system.

Objective To compare the accuracy of CT with other methods to measure the length of thoracic esophageal carcinoma. Methods 598 patients with thoracic esophageal squamous carcinoma were enrolled in this study.All the patients received three-field(cervical,thoracic:and abdominal)radical surgery without pre-operative radiotherapy or chemotherapy.The length of each Iesion was recorded and compared by measuring intraoperative specimen,formalin-fixed specimen,X-ray barium meal examination and CT,respectivelv. Results By the measurement of intraoperative specimen,formalin-fixed specimen,Xray barium meal examination and CT,the mean lengths of lesion were(5.22±1.94),(4.28±1.71),(5.12±1.92)and(6.71±2.52) cm,respectively.The measured length was significantly different between intraoperative specimen and formalin-fixed specimen or CT(t=16.01,P＜0.01;t=-15.54,P＜0.01),but not between intraoperative specimen and X-ray barium meal examination(t=1.62,P＞0.05).The measured lengths gradually decreased in the order of CT,intraoperative specimen,X-ray bailam meal examination and formalin-fixed specimen.For different pathological type(except intracavitary type)and different T staging,there was significant difference in lesion length between intraoperative specimen and CT(P＜0.05),but not between intraoperative specimen and X-ray barium meal examination(P＞0.05). Conclusions The length of esophageal carcinoma measured by intraoperative specimen is shorter than by CT,but longer than by X-ray barium meal examination.Specimen could shrink after foriBalin fixation.X-ray barium meal and other examinations should be referred when using CT to delineate tumor target volume of esophageal carcinoma for radiotherapy.