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Objective To investigate whether ultrasound (US)-targeted microbubble (MB) destruction (UTMD) can influence the biofilm and bacteria in morphology.Methods Twenty-hour biofilms of Staphylococcus epidermidis RP62A were treated with US or UTMD.The acoustic intensity was 0.5-1.5W/cm2,the duty cycle was 50％ and the duration was 10 minutes.After treatment,the absorbance values (A570) of biofilms stained with the crystal violet were measured to assess the biofilm density.The biofilms were observed with macroscopy and light microscopy.The biofilms were examined by confocal laserscanning microscopy (CLSM) and scanning electron microscopy (SEM).Results A thick and compact biofilm was observed in the untreated control group,and there were no obvious micropores in biofilms under macrology and light micrology.Although there were no significant changes under macroscopy in both biofilms treated with US only and UTMD with 0.5 W/cm2 acoustic intensity,interestingly,many micropores could be found under microscopy.The diameters of micropores increased with increasing acoustic intensity,and the micropores in biofilms treated with UTMD were bigger than those treated with US-only in the same condition of acoustic intensity (P ＜0.05).The largest diameters of micropores were up to 1 mm in biofilms treated with UTMD using 1.5 W/cm2 (P ＜0.05).The biofilm density (A570 value) decreased with increasing of the acoustic intensity,and the values in UTMD group of 1.5 W/cm2 were the lowest (P ＜ 0.05).Micropores also could be observed under CLSM.There were no obvious dead bacteria in biofilms treated with US and UTMD compared with untreated control group (P ＞0.05).Under SEM,the shape of bacteria in biofilms treated with US and UTMD became irregular,and many rounded projection could be observed in the surface of the bacteria treated with UTMD.Conclusions US and UTMD can produce micropores in biofilms,which might help to promote antibiotic activity against biofilms
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Objective To varify contrast-enhanced ultrasound (CEUS) quantitative analysis plaque enhancement is able to assess the intraplaque neovascularization.Methods The abdominal aortas were examined with CEUS in 9 atherosclerosis rabbits established by feeding high-fat diet.Sonographic examinations were performed with ultrasound instruments equipped with low mechanical index contrast imaging software.Contrast agent SonoVue was used with a dose of 0.2 ml,The enhanced intensity (EI) with the plaque and the ratio of EI within the plaque to that in the lumen of the carotid artery was calculated with QLab software,Each aorta specimen was stained with F8 (von willebrand factor) for mierovessel.The quantitative parameters EI and ratio were compared with the immunohistochemical study results.Results The mean value of EI and ratio were (3.91 ± 0.87)dB and 0.30 ± 0.06,respectively.Five specimens showed positive F8 staining and 4 showed negative.EI and ratio were significantly greater in positive group than in negative group [(4.47 ± 0.60) dB vs (3.22 ± 0.62) dB,0.34 ± 0.05 vs 0.25 ± 0.05].CEUS quantitative parameters EI ( r =0.779,P =0.013) and ratio ( r =0.693,P =0.019) were correlated to microvessels marked with F8,respectively.Conclusions It is histologically validated that CEUS quantifies the neovascularization in atherosclerosis plaques.CEUS provides a window for plaque risk stratification.
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Objective To investigate the effect of gene transfection to mice's muscle combining polyethyleneimine (PEI) with ultrasound (US)-targeted microbubble (MB) destruction (UTMD).Methods Twenty-five female Balb/c mice were divided into 5 groups (5 mice per group) randomly.Plasmid DNA (20 μg) encoding green fluorescent protein (GFP) was used as expresion vector.The transfection materials were injected into the bilateral tibialis anterior muscles of mice respectively and delivered as follows:(a) untreated control,(b) plasmid + US,(c) plasmid + US + MB,(d) plasmid + PEI,(e) plasmid + PEI + US,(f) plasmid + PEI + MB+ US.SonoVue MB was used at a final concentration of 30％ (v/v).The acoustic intensity and duty cycle were optimized before the study and set at 2.0 W/cm2 and 50％ respectively.Transfection efficiency was assessed by counting the number of GFP-positive fibers under fluorescence microscopy 10 days after gene delivery.Hematoxylin-Eosin staining was performed on separate specimen and examined with light microscopy for tissue damage.Results No GFP-positive fiber was found in the untreated control group.There were 14 ± 3,58 ± 6,96 ± 7,119 ± 11 and 158 ± 18 GFP-positive fibers respectively found in plasmid+ US,plasmid + MB + US,plasmid + PEI,plasmid + PEI + US,and plasmid + PEI + MB + US groups.The plasmid + PEI + MB + US group had the maximal GFP-positive fibers,the differences were significant compared with other groups (P ＜0.05).No evidence of inflammation or necrosis was revealed in histological examination with hematoxylin-eosin staining.Conclusions PEI combining with UTMD can significantly improve efficiency of gene transfection in vivo and has great potential in gene therapy.
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Objective To probe the correlation between the short-axis diameter(SD) of coagulation necosis and the microwave power(P) using a new type of internally cooled microwave antenna in ex vivo and in vivo liver model.Methods Fourteen microwave ablations were performed in swine livers ex vivo and canine livers in vivo under the microwave powers of 30-90W and the durations of 10 min and 20 min, respectively.The short-axis diameter(SD) and the long-axis diameter(LD) of the coagulation were measured.The difference of SD, LD and SD/LD in swine liver ex vivo and canine liver in vivo were compared.The relationship between the SD and microwave power was analysised using linear regression model.Results Under the same conditions,the SDs and LDs of the coagulations of canine livers in vivo were smaller than those of swine livers in ex vivo (P <0.01).There was such a higher linear relationship(r = 0.96-0.99, P <0.01) between the SD of coagulation and the power in vivo liver model as the results acquired in ex vivo.Conclusions Although the blood flow decreased the SDs of the coagulation of microwave ablation in liver in vivo, but there was still a higher linear relationship between SD and microwave power.
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2, but precise estimation of stenoses was impossible on CDUS. The stenosis degree and the length of stenosis measured by contrast-enhanced harmonic gray scale imaging were correlated well with those of DSA(r= 0.94 and 0.63 , respectively). Conclusions Microbubbles fill the arterial lumen with echoes at contrast-enhanced harmonic gray scale imaging. The ability to visualize the inner and outer surfaces of the vascular wall improved the evaluation of luminal abnormalities.
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Objective To probe the correlation between the short-axis diameter(SD) of microwave coagulation and the time(T) and/or power(P) using a new type of internally cooled microwave antenna. Methods A MTC-3 microwave apparatus with a new type of internally-cooled microwave antenna was used to coagulate a fresh porcine liver in vitro. The correlation was analyzed between the SD of coagulation necrosis and the time and/or power. Results ①Under the same power, there was high linear relationship(r= 0.94- 0.98,P
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Objective To evaluate the diagnosis value of contrast-enhanced real-time harmonic gray scale imaging in the diagnosis of renal artery stenosis.Methods Sixteen patients with renal artery stenosis including 4 patients after stent placement were enrolled.Ultrasound contrast agent SonoVue was used.All patients were examined with conventional color Doppler sonography and real-time harmonic gray scale imaging.The diagnostic results were divided into three scales:①no diagnosis result;②doubted diagnosis;③unequivocal diagnosis. The results were compared with those of digital subtraction angiography,CT and MRI.Results Unequivocal diagnosis were achieved in 50.0% (8/16) patients,doubted diagnosis in 31.3% (5/16),no diagnostic result in 18.7% (3/16) on conventional color Doppler sonography;the ratio was 81.3% (13/16), 12.5% (2/16), 6.2% (1/16),respectively on contrast-enhanced real-time harmonic gray scale imaging.The sensitivity,specificity and accuracy of conventional color Doppler scanning were 63.6% (7/11), 40.0% (2/5) and 56.3% (9/16),respectively;those of real-time harmonic gray scale imaging were 83.3% (10/12),100%(4/4) and 87.5% (14/16),respectively.Conclusions Contrast-enhanced real-time harmonic gray scale imaging depicts the margin of the vascular lumen and outer wall directly.Therefore real-time harmonic gray scale imaging may be more helpful in the diagnosis of renal artery stenosis.