Objective To access the relation between the Doppler waveform of the hepatic venous flow and the hepatic fibrosis.Methods To construct fibrosis models,20 experimental rabbits were fed with thioacetamide as the only drinking water at the concentration of 1.2 g/L,then the Doppler waveforms of the hepatic vein were detected at the time before constructing the fibrosis model,then later the 8th week,12th week and 16th week during constructing the fibrosis models,the results were compared with the hepatic biopsy ones.Results With the process of constructing the fibrosis models,the experimental rabbits had more abnormal Doppler waveforms of the hepatic venous flow.Conclusions The changes of the Doppler waveforms of the hepatic venous flow reflect the change of hepatic parenchyma.

Objective To investigate the effect of microbubbles mediated ultrasound insonation on proliferation and apoptosis of vascular smooth muscle cells (VSMCs) in different phase of cell cycle. Methods Rat thoracic aortic VSMCs were cultured in vitro by the method of tissue adherence. The cells were synchronized by the methods of serum starvation and double thymidine block. The synchronization results were detected by flow eytometer. VSMCs in different phases of cell cycle were exposed to 1 MHz continuous waves ultrasound for 120 s at intensity 0.3 W/cm2 in the presence of lipid-coated microbubbles (1 ml/L). Apoptosis of VSMCs was analyzed by AnnexinV/PI staining using flow eytometry. The proliferation and the proliferating cell nuclear antigen(PCNA) protein expression of VSMCs were detected by MTT assay and immunoeytochemistry, respectively. Results The synchronized G0/G1 and S phase VSMCs were achieved, with synchronized rates to 89.53 % and 66.87 %, respectively. Ultrasound sonication for 120 s with microbubbles could significantly inhibit the proliferation and downregulate the PCNA expression of S phase VSMCs,but the proliferation and PCNA expression of G0/G1 phase VSMCs were not affected. After treatment of ultrasound with microbubbles, the apoptotic ratio were found to reach (7.05 ± 2.04)% in G0/G1 phase VSMCs and (27.01 ±3.87)% in S phase VSMCs. Conclusions Microbubbles mediated ultrasound insonation can significantly inhabit the proliferation and induce apoptosis in VSMCs at proliferation stage.

Objective To investigate the effect of ultrasound irradiation combined with liposome membrane microbubbles on the reorgnization of cytoskeleton in vascular smooth muscle cells (VSMCs). Methods Rat thoracic aortic VSMCs were cultured in vitro. VSMCs were exposed to 1 MHz continuous waves ultrasound radiation for 120 s at intensity 0.3 W/cm2in the presence of liposome membrane microbubbles (1 μl/ml) after treated with platelet derived growth factor-BB (PDGF-BB). The reorganizations of microfilaments, microtubules and intermediate filaments were examined by using immunofluorescence and fluorocytochemistry techniques. Results There was a substantial increase in the expression of F-actin and assembly of long bundles of stress fibers in the transversed cell body when treated with PDGF-BB. Neither alterations of β-tubulin nor of vimentin cytoskeletal protein organization were observed in PDGF-BB treated cells as compared to those of the contol group. After ultrasound irradiation combined with liposome membrane microbubbles, the expression of F-actin, β-tubulin and vimentin were reduced along with the simultaneous changes in microfilaments, microtubles and intermediate filaments array. Conclusions Ultrasound irradiation combined with liposome membrane microbubbles can induce significant changes in cytoskeleton structure of VSMCs cultured in vitro.

Objective To investigate characteristics and ultrasonic imaging of the nano-scale ultrasound-enhanced contrast in vivo. Methods Nano-scale microbubbles were prepared by machine vibration and low speed centrifugation. The surface morphology and average size distribution of microbuble were measured. The contrast-enhanced effect of the hahn-scale microbubbles in the normal rabbit liver was observed,and compared with micro-scale microbubbles. Results The nano-scale microbubbles had a good shape and uniform distribution by light microscope and transmission electron microscope, with average diameter of 623.4 nm and surface electric potential of 1.3 inV. The contrast imaging study in vivo showed the nano-scale microbubbles could significantly enhance ultrasonic imaging of rabbit livers, which had no obvious difference with micro-scale microbubbles. Conclusions The nano-scale ultrasound contrast agent is stable and effective for the enhancement of ultrasound imaging, which is based on development of miniaturizing targeting ultrasound contrast agent.

Objective To promote in vitro tissue-plasminogen activator(t-PA)thrombolysis by using microbubbles augmented low frequency ultrasound(US) insonication.Two kinds of microbubbles,albumin-coated vs.lipid-coated were compared.Methods Human blood clot weighted 200～300 mg was made from of 0.8 ml fresh blood.Twenty kHz ultrasound,lipid and albumin-coated microbubbles were applied to separate clots groups with or without t-PA administration.The clots before and after processing were weighed and then the clot dissolution ratios were calculated.Results The simple ultrasound group and the basic t-PA group dissolved((24.72)?(4.83))% and((35.66)?(3.34))% of the clots,respectively.The clot dissolution ratio rised to((42.06)?(4.20))% when coordinated US and t-PA(P(0.05)).Conclusions The in vitro US augmentation of t-PA thrombolysis can be significantly promoted by introduction of microbubbles.But there is no significant thrombolysis difference between albumin and lipid-coated microbubbles.

Objective To investigate the effect of a self made liposome perfluocarbon ultrasound contrast agent in enhancing grey scale imaging of normal kidney.Methods The kidneys of 10 normal rabbits were imaged with second harmonic imaging before and after intravenous injection of the liposome contrast agent at a dose of 0.01 ml/kg. The subjective scores and video intensities were used to evaluate contrast effects. Results The renal cortex,medulla and sinus grey scale imaging were greatly enhanced after injection, and the notable enhancement time of renal cortex,medulla and sinus could last for 52 min,2 min 20 s,1 min 40 s,respectively. Conclusions The self made liposome perfluocarbon contrast agent can significantly long time enhance the grey scale of the kidney.

Objective To prepare human hepatocellular carcinoma targeted liposome microbubbles and investigate their immunological properties.Methods Human hepatocarcinoma specific monoclonal antibody HAb18 was attached to the surface of self made liposome microbubbles by electrostatic attraction to prepare immunoliposome microbubbles.The combination of HAb18 with liposome microbubbles was proved by slide agglutination test and immunofluorescent assay.Their immunological activity was measured by ELISA.Rosset formation test,rosset formation blocking test and immunofluorescent assay were used to identify the specific binding of immunoliposome microbubbles to SMMC 7721 cells,while cytotoxicity assay was used to detect their effect on human hepatocytes.Results Immunoliposome microbubbles were positive in slide agglutination test and immunofluorescent assay.ELISA indicated that the immunological activity of HAb18 on liposome microbubbles was similar to that of free HAb18.SMMC 7721 cells were surrounded by immunoliposome microbubbles to form rossets,while control cells were negative.Proliferation of human hepatocytes was not influenced by immunoliposome microbubbles.Conclusions Immunoliposome microbubbles with high specific biological activity were prepared successfully.The contrast agent can bind to human hepatocarcinoma cells specially and effectively.The results may pave the way for further studies.

Objective To explore the value of diagnostic ultrasound mediated microbubble destruction in improving the myocardial perfusion and left ventricular systolic function when cooperated with the mecsenchymal stem cells(MSCs) transplantation in rabbit myocardial ischemia. Methods One week after myocardial ischemia (MI) modeling,36 rabbits were divided into 3 groups,the control group(group Ⅰ) ,intravenous injection of MSCs group(group Ⅱ) and ultrasound + microbubble + MSCs group (group Ⅲ). Myocardial contrast enhancement (MCE) was performed and quantification analysis of anterior wall was assessed with Photoshop. Left ventrieular systolic function was assessed with M-mode echocardiography and bi-plane Simpson's method. CD34 expression in heart was detected with immunohistochemisty(IHC). Western blotting was applied to detect the level of VEGF in three groups. Results The differences of gray scale analyzed with histogram of Photoshop in anterior wall of ischemia myocardium between the group Ⅰ and group Ⅱ or group Ⅲ were significant,and P value was 0. 032 and 0. 000 , respectively. There were significant differences of FS between group Ⅲ (30. 43±4.09)% and group Ⅱ (26.29±2.93)%, P<0.01, and similar to group Ⅰ (19.28 ± 2.84)%. The difference of EF(%) between group Ⅲ and group Ⅱ was significant [(61.5±5.8 vs 53.6±4. 71), P<0. 05] ,or markedly significant between group Ⅲ and group Ⅰ [(61.5±5.8 vs 42.6± 5.0), P <0.01]. EF(%) assessed with bi-plane Simpson's method was significantly increased from (34.64 ± 4.59) in group Ⅰ to (41.78 ± 4.21) in group Ⅱ and (48.6±3.96) in group Ⅲ. The expression of CD34 assessed with immunohistochemistry was the highest in group Ⅲ. The level of VEGF with western blotting in group Ⅲ was significantly higher than other two groups. Conclusions It is an efficacious transplantation means of MSCs infusion under the ultrasound mediated microbubles destruction in improving the myocardial perfusion and cardiac systolic function.

Objective To explore the targeting homing capacity of bone-marrow derived mesenchymal stem eells(MSCs) on rabbit myocardial ischemia by intravenous injection of MSCs under the mediation of diagnostic ultrasound and microbubble. Methods Density gradient centrifugation and adherent culture method were used in the isolation and cultivation of MSCs. MSCs were labeled with DAPI. Rabbit myocardial infarction(MI) models were builded by totally ligation of left anterior descending branch of coronary artery. DAPI labeled MSCs were implanted by intravenous injection with or without the mediation of diagnostic ultrasound and microbubbles. Forty-eight hours after cell transplantation, the hearts of MI rabbits were made of frozen section and observed under fluorescent microscope. The DAPI positive cells were counted in the MI and border area of rabbit heart and compared between two groups. Pathological changes of MI area were observed with HE staining under light microscope and transmission electronic microscope. Results The number of DAPI positive cells in MI and border area of rabbit in both groups were counted under fluorescent microscope. There were more DAPI positive cells in the MI area in ultrasound + microbubble + MSCs group (213.2±26.5) than that in the intravenous injection group (146.8±18.78, P<0.01). There were erythrocytes leaking out of the vessels in MI area in HE staining section under light microscope in ultrasound + microbubble + MSCs group while there were nearly none in the intravenous injection MSCs group. The intercellular space of endothelial cells of the vessels wall was increased and serum component leaked out of the vessel wall in ultrasound + microbubble + MSCs under transmission electronic microscope. Conclusions The targeted homing capacity of BM-MSCs in the MI area of rabbit heart can be enhanced under the mediation of diagnostic ultrasound and microbubbles.

Objective To investigate the mechanism of the increased permeability of the blood-brain barrier during transcranial ultrasound contrast imaging. Methods Sprague-Dawhy (SD) rats were performed transcranial ultrasound contrast imaging, the lanthanum nitrate and the evans-blue were used as tracers,the distribution of the tracers were observed and the transports mechanism were also investigated. Results The opening of the tight junction and increased permeability of the cellular membrane were observed after the transcranial ultrasound contrast imaging. Conclusions The main mechanism of the increased permeability of the blood-brain barrier was the opening of the tight junction and increased permeability of the cellular membrane.