Objective To investigate the changes of action potential duration (APD) and transient outward K + current (I to) and inward rectifier K + current(I K1) of ventricular myocytes after 3 weeks of myocardial infarction, and to inquire into the effect of bisoprolol. Methods APD was recorded with microelectrode. Ventricular myocytes were singly isolated from rabbit heart using modified Langendoff perfusion and soaked with collagenase. I to and I K1 of single rabbit ventricular myocytes were recorded by whole-cell path-clamp technique. Results Both APD 50 and APD 90 of the cell from noninfarcted region in MI group were markedly longer than that in sham group (P

0.05), while when the CARTO technology was used, the mean fluoroscopy time was significantly shorter (6.3?2.6min vs 16.2?7.0min,P

Objective To observe the short-term curative effect of biventricular cardiac resynchronization therapy in patients with chronic heart failure.Methods Twenty-six patients with chronic heart failure underwent biventricular cardiac resynchronization therapy,and a left ventricle lead was implanted from the coronary sinus to vein.During the 3-34(13.8?10.4)months of follow-up period,the following parameters were recorded:the cardiac function,patients' activity,heart rate at night,QRS wave width,left ventricular end-systolic dimension(LVESD),left ventricular end-diastolic dimension(LVEDD),end-systolic volume(ESV),end-diastolic volume(EDV),left ventricular ejection fraction(LVEF),left ventricular filling time,and standard deviation of time to regional peak systolic velocity(Ts-Sd-12).Results One out of the overall 26 patients died from sudden cardiac death.The cardiac function was improved in the 25 survivals in the 3-months follow-up,showing that the effective rate of CRT was 96.2%.For the 25 patients,the cardiac function was improved according to New York Heart Association(NYHA)functional class from Ⅲ-Ⅳ grade to Ⅱ-Ⅲ grade.The average total activity time was increased from 0.31?0.40 hours per day to 2.35?1.20 hours per day.Average heart rate during night-time was decreased from 84.8?15.7 beats per minute to 63.4?4.5 beats per minute,variability of cardiac rhythm was raised from 47.3?7.1ms to 96.4?15.1ms;QRS duration was shortened from 158.6?31.8ms to 129.5?30.2ms(P

Objective: To address the significance of urinary podocytes in the diagnosis of human focal segmental glomerulosclerosis(FSGS). Methods: Twelve patients with FSGS and 20 patients with minimal change disease (MCD) were diagnosed by routine renal biopsy, and 8 healthy persons as controls. Morning urinary sediments was collected and centrifuged onto glass slides. Urinary podocytes were identified by immunofluorescent staining of podocyte specific protein Podocalyxin(PCX). The state of podocytes in glomeruli was observed using immunofluorescence. Results: Urinary podocytes were found in 8 out of 12 FSGS patients(66.67%), whereas none of 20 patients with MCD and control had podocytes in their urine. FSGS patients with positives urinary podocytes had prominent manifestation of nephropathy syndrome, whereas no nephrotic syndrome in patients with negative urinary podocytes. Focal absence of the expression of PCX, a marker protein of podocytes in glomeruli was found in FSGS patients, and the locations of absence were consistent with the lesions of focal sclerosis in glomeruli. In contrast, PCX was expressed integrally in MCD patients. Conclusion: Appearances of podocytes in urine of patients with nephropathy may be used as one of the reliable, convenient and unharmful accessorial methods for distinguished diagnosis of FSGS and MCD.

Objective:To investigate the anti-fibrotic effect of sirolimus(rapamycin)at the cell level.Methods:The primary cultured rat renal cortical myofibroblasts were divided into two groups,control group and sirolimus 40 mg/L group at each time point.The protein levels of ?-SMA,Col-Ⅰ,fibronectin(FN)were analyzed by Western blot in both the whole cell lysates and supernatant culture media 12 h,24 h and 48 h after incubation,respectively.Real-time quantitative PCR was carried out to measure the levels of procollagen-ⅠmRNA 1 h,2 h,4 h,and 6 h after cell incubation.The activities of gelatinase MMP-2 and MMP-9 in the supernatant from the cultured cell media were assayed by gelatin zymography.Results:(1)Sirolimus had no effect on the expression of ?-SMA of myofibroblasts at differnet time points.(2)The expression of Col-Ⅰin the whole cell lysates both reduced at the end of 24 h and 48 h in sirolimus group significantly [(0.58?0.05)and(0.63?0.18),P

Objective To determine which parameters of reverse remodeling of left ventricular could become the effective indexes in evaluating the short-term therapeutic effect of cardiac resynchronization therapy(CRT)in heart failure(HF)patients.Methods CRT was performed in 26 HF patients with dysfunctions of wall motion.Serial echocardiography was practiced at baseline,one and three months after CRT.The parameters including left atrial end-diastolic diameter(LADD),left ventrieular end-diastolic diameter(LVDD),end-diastolic volume (LVEDV),end-systolic volume(LVESV),ejection fraction(LVEF)were measured and compared before and after CRT therapy.Results At one and three months after CRT,respectively,CRT was associated with reduced LADD,LVDD,LVEDV,LVESV and improved LVEF and filling time compared with those at baseline.Moreover,all these parameters had better correlations with the activities of these patients.Conclusions LADD,LVDD,LVEDV,LVESV and LVEF could become the effective indexes in evaluating the short-term effect of CRT in HF patients.The reduced diameters and volumes of left atria and left ventricle are more sensitive parameters than the improved LVEF.

BACKGROUND: Angiotensin Ⅱ has been found to induce atrial electrical remodeling, which can be blocked or inhibited by allicin.OBJECTIVE: To study the effects of allicin on angiotensin Ⅱ-induced calcium channel current and intracellular free calcium concentration in human atrial myocytes.DESIGN: A randomized controlled study based on human atrial myocytes freshly isolated.SETTING: Cardiology department of a military medical university of Chinese PLA.METHODS: This study was carried out from June 2003 to June 2004 in the Laboratory of Cardiology Department, Xijing Hospital, the Fourth Military Medical University of Chinese PLA. Ten patients with congenital heart disease who underwent extracorporeal circulation surgery were included in the study. Among them, there were 6 males and 4 females with the average age of 15 ± 6 years. Tissue samples were taken from their right auricle and sent to the lab, where the atrial myocytes were freshly isolated. There were four co-administration of angiotensin Ⅱ (0. 1 μmol/L)and allicin(50 μmol/L).The conventional whole-cell configuration of the patch-clamp technique was used to detect membrane electric current of Ca2 + in L type. Confocal microscope was used with Fluo-3/AM as calcium indicator to detect changes of intracellular free calcium concentration immediately and 15 minutes after drug intervention, respectively.MAIN OUTCOME MEASURES: The peak density of electric current of Ca2 + in L type and alteration of fluoresence intensity of intracellular free calcium concentration.electric current of Ca2 + in L type in human atrial myocytes was significantly increased by angiotensin Ⅱ of 0. 1 μmol/L[( - 12. 77 ± 1. 61) vs ( -5.78affect electric current of Ca2+ in L type in human atrial myocytes group, the peak density of electric current of Ca2 + in L type was significantly lower than that in angiotensin Ⅱ group[ ( - 8.75 ± 0.97) pA/pF, P ＜ 0. 05 ].in angiotensin Ⅱ group was significantly higher than that in control and allicin groups[(2 610.1±112.6, (299.2±27.3)%; 653.9±42.5, 0;simultaneously with angiotensin Ⅱ, the alteration of intracellular fluoresence intensity was much lower than that in angiotensin Ⅱ group[ ( 1284.9 ± 85.2,(96.5±8.4)%;P ＜0.05].CONCLUSION: Allicin antagonizes angiotensin Ⅱ-induced increase in the peak density of electric current of Ca2+ in L type and intracellular calcium overload, which may relieve atrial electrical remodeling.

BACKGROUND: Vascular smooth muscle cell(VSMC) is one of the major cell components of vascular wall and its pathologic effects in atherosclerosis has been verified and recognized. How to inhibit VSMC proliferation and migration becomes one of the hotspots in the researches regarding the prevention of coronary heart disease(CHD).OBJECTIVE: To observe the impacts of diethyl-2, 6-diethyl-4-furny-1,4-dihydropyridine-3, 5-dicarboxylate(EFDP) on angiotensin Ⅱ (Ang Ⅱ)-induced VSMC proliferation.DESIGN: A randomized controlled study based on VSMC of rabbit' s thoracic aorta cultured in vitro.SETTING: Department of cardiology in a military medical university of Chinese PLA.MATERIALS: The study was conducted in the Laboratory of Cardiology of Xijing Hospital of the Fourth Military Medical University of Chinese PLA between August 2003 and June 2004. Five New Zealand rabbits were selected for the harvest of VSMC. Animal cells were randomly divided into control group, Ang Ⅱ group and Ang Ⅱ + EFDP group(EFDP group).METHODS: New Zealand rabbits were fed by high-fat food. Thoracic aorta was harvested for the separation and culture of VSMC after the injury in thoracic aorta intima by sacculus. The experiment introduced the cultured rabbit VSMC to observe the impacts of EFDP on VSMC DNA synthesis and its time effect during VSMC proliferation promoted by Ang Ⅱ by 3H-TdR method.MAIN OUTCOME MEASURES: 3H-TdR intensity of radio activity in cells of each group to display the DNA synthesis during VSMC proliferation process.RESULTS: Ang Ⅱ could promote the synthesis of rabbit VSMC DNA, which hit its peak at the 36th hour compared with that of control group(358. 00± 49.01 vs 272.42 ± 54.96, P ＜ 0. 01 ) . EFDP had significant inhibitive effects on Ang Ⅱ-induced VSMC proliferation, which also displayed a significant dose-dependent relationship, i.e. with the elevation of EFDP concentration, its inhibitive rate on VSMC proliferation also gradually increased. At the 36th hour, 78.40 μ mol/L of EFDP had more significant effect than that of 0. 08 μmol/L of EFDP(281.50 ± 15.28 vs 349. 25 ±32.10, P＜ 0. 05).CONCLUSION: EFDP can significantly inhibit Ang Ⅱ-induced rabbit VSMC proliferation with certain dose-effect dependency and time responses,which provides a theoretical gist for the primary rehabilitative prevention of atherosclerosis.

Objective To investigate the effects of low frequency pulsed magnetic fields (LF-PMFs) on proliferation, the cell cycle, apoptosis, migration, cytoskeleton formation and nitric oxide (NO) secretion in cardiac microvascular endothelial cells (CMECs). Methods LF-PMFs with rectangular and triangular waveforms at 15 Hz were tested. The CMECs were randomly divided into a control group, 0.6 mT group, 1.2 mT group, 1.8 mT group and 2.4 mT group. Except for the control group, the CMECs were exposed to LF-PMFs 4 h/day for 5 days. Results After 5 days of intervention with rectangular wave LF-PMFs the proliferation of CMECs accelerated and NO secretion was enhanced significantly. The percentages of cells at ( S+G2 ) phase increased significantly, whereas apoptosis rates were significantly lower than in the control group. The migration of CMECs was facilitated, stress fibers increased and cytoskeleton components were reorganized. After 5 days of intervention with triangular wave LF-PMFs proliferation of CMECs accelerated and NO secretion was significantly enhanced. The percentages of cells at(S+G2)phase and migration increased, while apoptosis was inhibited. Cytoskeleton components were reorganized after exposure to 0.6 mT and 2.4 mT triangular waveform LF-PMFs. No significant change was detected with 1.2 mT and 1.8 mT triangular waveform LF-PMFs with regard to these variables. Conclusions The effects of LF-PMFs on proliferation, the cell cycle, apoptosis, migration, cytoskeleton formation and NO secretion function of CMECs were infiuenced by the waveform in addition to it's intensity and frequency.

AIM: To examine the effects of hydrogen peroxide on intracellular free calcium concentration([Ca~(2+)]i) in cardiomyocytes and its antagonism by taurine. METHODS: A cell culture model of neonatal rat cardiac myocytes was used. There were four groups, control group, hydrogen peroxide (H_2O_2) group, H_2O_2+taurine (simultaneously) group,and H_2O_2+taurine (in sequence) group. Confocal microscope was used with Fluo-3/AM as calcium indicator to detect changes of [Ca~(2+)]i immediately and 15 minutes after H_2O_2 intervention, respectively. RESULTS:The intracellular fluoresence intensity of singular cardiomyocyte in H_2O_2 group was significantly higher than the control group 15 minutes after intervention (P