Objective To quantitatively describe the texture features of myocardial image in the acute myocardiac infarction (AMI) using image texture analysis. Methods Anterior descending branch of left coronary artery was ligated to set up AMI model in 11 dogs. Image texture was analyzed using grey tone co-occurrence matrix method, and 4 kinds of texture parameters including angular second moment(ASM), contrast(CON), entropy(ENT), and inverse difference moment(IDM) in normal myocardium and infarct myocardium were observed. Results A significant difference in 4 kinds of texture parameters was found between pre- and post-infarct myocardium (P

To evaluate the morphology of atrial septum by the live three-dimensional echocardiography (L3DE) and its value of clinical application, L3DE was performed in 62 subjects to observe the morphological characteristics and dynamic change of the overall anatomic structure of atrial septum. The study examined 49 patients with atrial septal defect (ASD), including 3 patients with atrial septal aneurysm, and 10 healthy subjects. ASD in the 35 patients was surgically confirmed. The maximal diameters of ASD were measured and the percentages of area change were calculated. The parameters derived from L3DE were compared with intraoperative measurements. The results showed that L3DE could directly and clearly display the morphological features of overall anatomic structure of normal atrial septum, repaired and artificially-occluded atrial septum, atrial septal aneurysm. The defect area in ASD patients changed significantly during cardiac cycle, which reached a maximum at end-systole and a minimum at end-diastole, with a mean change percentage of 46.6%, ranging from 14.8% to 73.4%. The sizes obtained from L3DE bore an excellent correlation with intraoperative findings (r=0.90). It is concluded that L3DE can clearly display the overall morphological features and dynamic change of atrial septum and measure the size of ASD area accurately, which is important in the decision to choose therapeutic protocols.
Atrial Septum/*ultrasonography ; Echocardiography, Three-Dimensional/*methods ; Heart Septal Defects, Atrial/*pathology ; Heart Septal Defects, Atrial/*ultrasonography ; Young Adult

The effects of cardiomyocyte grafting on left ventricular (LV) remodeling and function in rats with chronic myocardial infarction were evaluated using high-frequency ultrasound. Chronic myocardial infarction was induced in 50 Wister rats by ligating the left anterior descending artery. They were randomized into two groups: a trial group that received neonatal rat cardiomyocyte transplantation (n=25) and a control group which were given intramyocardial injection of culture medium (n=25). The left ventricular (LV) geometry and function were evaluated by high-frequency ultrasound before and 4 weeks after the cell transplantation. After the final evaluation, all rats were sacrificed for histological study. The results showed that 4 weeks after the cell transplantation, as compared with the control group, the LV end-systolic dimension, end-diastolic dimension, end-systolic volume and end-diastolic volume were significantly decreased and the LV anterior wall end-diastolic thickness, LV ejection fraction and fractional shortening were significantly increased in the trial group (P<0.01). Histological study showed that transplanted neonatal rat cardiomyocytes were found in all host hearts and identified by Brdu staining. It was suggested that transplantation of neonatal rat cardiomyocytes can reverse cardiac remodeling and improve heart function in chronic myocardial infarction rats. High-frequency ultrasound can be used as a reliable technique for the non-invasive evaluation of the effect of cardiomyocyte transplantation.
Animals, Newborn ; Echocardiography/*methods ; Myocardial Infarction/physiopathology ; Myocardial Infarction/*therapy ; Myocardial Infarction/ultrasonography ; Myocytes, Cardiac/*transplantation ; Random Allocation ; Rats, Wistar ; Ventricular Function, Left/*physiology ; Ventricular Remodeling

AIM: To evaluate myocardial relaxation function changes in an adriamycin-induced cardiomyopathy model using the transmitral flow velocity to mitral annular velocity ratio (E/E'), a strong positive relationship with left ventricular filling pressure and a good indicator for evaluating left ventricular diastolic relaxation abnormality. METHODS: Twenty-eight Japanese rabbits were divided into two groups. Adriamycin was administered at cardiomyopathy model. 8 rabbits served as controls receiving the same amount of saline once a week for a total of 8 weeks. Conventional and tissue Doppler echocardiography (TDE) were performed at baseline, 4th, 6th,8th, 10th and 12th week. RESULTS: In the adriamycin-treated group, LV chamber diameter significantly increased, while ejection fraction and fraction shortening significantly decreased in 10th and 12th week (P ＜0.05). The significant changes were firstly found in 10th week. Mitral annulus systolic peak velocity (S') by TDE significantly decreased in 8th, 10th and 12th week ( P ＜0.05). The significant changes were firstly found in 8th week. The ratio of E/E' significantly increased in 6th,8th, 10th and 12th week (P ＜ 0.05). The significant changes were firstly found in 6th week. In the control group, no significant changes were found in all parameter by tissue Doppler conventional echocardiography (P ＞0.05). CONCLUSION: Myocardial function is reduced in adriamycin-induced rabbit model of dilated cardiomyopathy. The relaxation parameter (E/E') by TDE changes is earlier than contraction indices S' by TDE and conventional echocardiography in adriamycin-induced cardiomyopathy rabbits, which provides a new sensitive and reliable method to evaluate LV relaxation function.

AIM: To validate the alternations of flow velocity patterns in the infarct-related artery (IRA) during no-reflow phenomenon in a canine model of acute myocardial ischemia and reperfusion by transthoracic Doppler echocardiography (TTDE) combined with myocardial contrast echocardiography (MCE) by means of administration of Albunex. METHODS: Nineteen dogs first underwent 60 min myocardial ischemia and then followed by 60 min,120 min and 180 min reperfusion ( n = 6, 6 and 7, respectively). The perfusion defect area determined by MCE at 60 min myocardial ischemia was regarded as risk area (RAMCE). The perfusion defect area defined by MCE after reperfusion was considered as no-reflow area (NRAMCE). The ratio between NRAMCE and RAMCE ≥ 25 %was regarded as the development of no-reflow phenomenon and the ratio of NRAMCE to RAMCE＜25% was considered as the myocardial reflow. The coronary flow velocity parameters in IRA were determined through TTDE. RESULTS: Two dogs died during experiment and the remaining seventeen dogs completed throughout the procedure.There were seven dogs in reflow group and ten dogs in noreflow group. No significant difference was present in reflow group between at baseline and at 60 min reperfusion in systolic peak velocity (PVs), systolic velocity time integral (VT Is), corrected systolic flow duration (cFDs),diastolic peak velocity (PVd), diastolic velocity time integral (VT Id), corrected diastolic flow duration (cFDd),diastolic deceleration rate (DDR), corrected diastolic deceleration duration (cDDD) (P＞0.05), however, a significant difference was found in no-reflow group between at baseline and at 60 min reperfusion in PVs,VTIs, cFDs, PVd, VTId and cFDd (P＜0.05). The most marked alterations during diastolic phase were the increase of DDR and reduction of cDDD. CONCLUSION: The impaired microvasculature may profoundly affect the coronary flow velocity pattern in the IRA. The increase in microvascular resistance and decrease in coronary perfused pressure can contribute to the changes.Transthoracic Doppler echocardiography combined with MCE has the capability of noninvasive assessment of coronary flow velocity pattern in the IRA during no-reflow phenomenon.

Objective To probe into the clinical value of left atrial(LA) volme tracking method (LAVT) on the assessment of left atrial function in patients with hypertension. Methods Thirty-one patients with hypertension and 31 control subjects were involved. Images of apical two-chamber and four-chamber views were obtained by two-dimensional echocardiography. LA maximal volume (LAVmax), LA minimal volume (LAVmin), LA presystolic volume (LAVpre), systolic LA filling rate (dv/dtS), early diastolic LA emptying rate (dv/dtE) and late diastolic LA emptying rate (dv/dtA) were derived using LAVT. LA passive emptying volume(LAVp), LA passive emptying fraction(LAVpEF), LA active emptying volume(LAVa), LA active emptying fraction (LAVaEF), LA total emptying volume (LAVt), LA total emptying fraction(LAVtEF) were calculated. All volume measurements were corrected to body surface area (LAVI). Results There were significant differences in the LAVImax, LAVImin, LAVIpre, LAVpEF, LAVIa, LAVIt,dv/dtS, dv/dtA between hypertensive patients and control subjects(P <0.05~0.001), but no significant differences were found in the LAVp, LAVaEF, LAVtEF,dv/dtE between the two groups. The LAVImax has shown significant positive correlation with LAVIp, LAVIa and LAVIt(r = 0.588~0.812, P <0.001). LAVaEF has shown positive correlation with the LAVtEF(r = 0.833, P<0.001), whereas LAVpEF has not(r = 0.420, P <0.01). There was a significant positive correlation with LAVImax and LAVIpre(r = 0.908, P <0.001), LAVIpre and LAVIa(r = 0.689, P <0.001) ,dv/dtE and LAVIp(r = 0.690, P <0.001),dv/dtA and LAVIa(r = 0.600, P <0.001). Conclusions In hypertensive patients,left atrial reservoir function and booster pump function increase, while left atrial conduit function decreases. LAVT has a potential ability to evaluate left atrial function.

Objective To determine whether it could enhance gene delivery and tumor transfection in vivo by combination of ultrasound-targeted microbubble destruction(UTMD)with polyethylenimine(PEI)in tumor xenografts.Methods Two different reporter plasmid[lueiferase(pCMV-LUC)and red fluorescent protein(RFP)]were incubated with PEI to prepare cationic compound(PEI/DNA)in various nitrogen:phosphate ratios(N/P ratios,nmol of nitrogen in the PEI/nmol of phosphate in DNA).Formation of PEI/DNA complexes were confirmed by the gel retardation assay.Human cervical carcinoma(Hela)tumors were planted subcutaneously in both flanks of female nude mice.Tumor-bearing mice were administered by tail vein with PBS,plasmid,plasmid and Sono Vue microbubble,PEI/DNA and Sono Vue microbubble.One tumor was exposed to ultrasound irradiation (3 MHz,2 W/cm2,2 min exposure,duty cycle 20%),while the other served as control.The feasibility of targeted delivery and tissue specificity facilitated by UTMD and PEI was investigated.The mice were sacrificed 3 days after ultrasound exposure.Tissue specimens were viewed with microscopy to determine the presence of RFP expression.The efficiencies of luciferase transgene expression were determined.Histology analysis was detected.Results Electrophoresis experiment revealed that PEI was mixed with plasmid to condense DNA efficiently.The application of UTMD significantly increases the tissue transfection in vivo compared to plasmid alone.RFP expression was present in all sections of tumors that received ultrasound exposure but not in control tumors.Results of luciferase activity showed that the expression of luciferase was to be 14 times greater in ultrasound-exposed tumors(P＜0.01).More importantly,the increase in transgene expresgion was related to UTMD with the presence of PEI dramatically.At least 10-fold increase of luciferase gene transfer was obtained in irradiated tumors compared to non-irradiated controls(P＜0.01),111-fold increase compared to UTMD alone(P＜0.01).There was not significantly gene expression in other organs or tissues regardless of US exposure(P＞0.05).No tissue damage was seen histologically.Conclusions The combination of UTMD with PEI can enhance targeted delivery and expression of reporter gene to tumors at intravenous administration.It is a promising new and safe method for gene delivery in vivo.

Objective To investigate different ultrasound parameters and transfection conditions that would affect transfection rate of red fluorescent protein(RFP)and cell viability of cancer cells.Methods In this study,Hela cells were cultured using two different protocols:(A)24 h culture for complete adherence;(S)suspension.Subsequently,cells were transfected following different ultrasound exposure protocols[1.0W/cm2;duty cycle(DC):10%,20%and 50%;exposure 1min or 3 min].Gene transfection and cell viability were evaluated.Treatment parameters optimized in Hela cells were applied for delivery RFP in 4 other cell lines(HepG2,Ishikawa,MCF-7 and B16-F10).Results Cell injury were found to increase progressively with DC and exposure time in group A.Cell detachment was significantly accompanied by ultrasound exposure in adherent HeLa cells.Cells in group S were found more prone to be transfected than group A with the same ultrasound parameters,while the survival rate was not decreased apparently.The ideal ultrasound conditions were noted to be at 1.0 W/cm2 irradiated 3 min with 20%DC using suspended protocol,producing maximum efficiency[transfection=(28.04±2.27)%]in gene delivery with minimum cell toxicity[cell viability=(81.20±1.73)%].These experiments also revealed different response to ultrasound treatment,but for all tested cell lines,dead and transfected cells in the treated groups were significantly different from the non-irradiated groups.Conclusions Ultrasound parameters and transfection conditions have a great impact on the gene delivery and cell viability.Gene delivery of ultrasound-mediated microbubble enhance should be optimized to improve the efficiency.

Objective To study the optimized condition of transfection efficiency for MCF-7 cells enhanced by ultrasound(US) irradiation and contrast agent combined with polyethyleneimine(PEI) and observe whether the combination can have a synergistic effect to increase DNA transfection. Methods MCF-7 cells were transfected with the compounds prepared by the vector of plasmid DNA encoding luciferase (pCMV-luciferase-GL3) and PEI.SonoVue microbubble was added to the cell suspension to serve as nucleation sites for aeoustic cavitation before US irradiation. The DNA expression of luciferase plasmid and viability of cells were evaluated. The strategy of US irradiation was optimized. Furthermore, the influencing factor, such as the concentration of plasmid, incubation time, serum, the type of solvent and the volume of culture media, were examined. Results The viability of cells and US-induced enhancement of luciferase activity were influenced by the US intensity,exposure time and duty cycle.US irradiation under an appropriate condition enables ceils to accelerate the permeation of the PEI/DNA complex through the cell membrane, resulted in enhanced transfection efficiency of plasmid DNA. Optimal US condition for the enhancement was determined to be 1 W/cm2,10% DC for 3 min. In contrast to the PEI/DNA complex alone without US irradiation or US irradiation alone, the combination of US irradiation with contrast agent and PEI had a significantly enhanced luciferase activity (P<0.01). The 2 h pre-irradiation incubation with PEI/DNA complex for MCF-7 ceils exhibited a significantly enhanced lueiferase activity (P<0.01). Besides,serum,type of solvent and the volume of culture media did affect the transfection efficiency. Conclusions The optimized parameters of US and transfection provide efficient gene delivery in MCF-7 cancer cells. The combination of US irradiation with contrast agent and PEI has a synergistic effect to increase DNA transfection. This is a simple and promising method to enhance the gene expression of plasmid DNA.

Objective To investigate different pulsed ultrasound (PUS) parameters and culture conditionsthat would affect cell viability and sonoporation on cell membrane of human cervical cancer cells (HeLa). MethodsHeLa cells were cultured in two different conditions ( in suspension or in monolayer). Cells were exposed to differentPUS intensity (0.4 W/cm2, 1.0 W/cm2, 1.6 W/cm2, 2.2 W/cm2), duty cycle (10%, 20%, 50%) and expo-sure time ( 1 min or 3 min). Cell viability was analyzed by flow cytometry. Using microscope and scanning electronmicroscopy (SEM) , the changes of shape and the sonoporation on cell membrane induced by PUS were observed.Results Low intensity and duty cycle did not exert a great impact on the cell viability. Cell injury was found to in-crease progressively with high intensity ( 1.6 W/cm2 , 2.2 W/cm2 ) and duty cycle ( 50% ) ( P < 0. 01 ) , and celldetachment was significantly accompanied by PUS exposure in adherent HeLa cells. Results of factorial design showedthat the culture conditions and the PUS parameters had significant interaction ( P < 0.01 ). SEM demonstrated insome detail the phenomenon of transient pores in the cell membrane under suitable PUS irradiation. The ideal sonopo-ration conditions that cell viability was above 80% and more membrane holes were noted to be at 1.0 W/cm2 expo-sure for 3 min with a duty cycle of 20% in cell suspension. Conclusion The optimized conditions of the PUS pa-rameters and the culture conditions could lower the cell injury and exert a great impact on the sonoporation. It couldproduce remarkable membrane pores on cells and enhance cell membrane permeability, which facilitate transportationof macromolecules into cells.