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1.
A. Nemes M. L. Geleijnse R-J. van Geuns O. I. I. Soliman W. B. Vletter B. J. Krenning F. J. ten Cate 《Netherlands heart journal》2008,16(6):217-218
Dobutamine stress magnetic resonance imaging is considered the superior stress modality to detect wall motion abnormalities. In this report we demonstrate the strengths of a newly developed stress modality: dobutamine stress contrastenhanced real-time three-dimensional echocardiography. This stress modality may become a competitor of stress magnetic resonance imaging allowing fast acquisition and an unlimited number of left ventricular cross sections. Unfortunately, at the moment adequate imaging with stress realtime three-dimensional echocardiography is only possible in a minority of cardiac patients. (Neth Heart J 2008;16:217-8.) 相似文献
2.
J. Mahdiabadi A.A. Gaeini T. Kazemi M.A. Mahdiabadi 《Biology of sport / Institute of Sport》2013,30(3):207-211
Exercise plays an important role to improve cardiovascular performance. The aim of this study was to compare the effect of aerobic continuous and interval training on the left ventricular structure and function. Twenty untrained healthy male students (aged 18-22 years) were randomly divided into two groups: continuous (C; n = 10) and interval (I; n = 10). The training programme consisted of countryside jogging for 45 min during 8 weeks three times a week at 70% of maximum heart rate (MHR). In each session group C was jogging for 45 min and in group I jogging was performed in 5 nine-minute stages with a four-minute inactive rest between them. M-mode, 2-dimensional, colour and Doppler transthoracic echocardiography were performed, during resting conditions, before and after the training period. After 8-week training the end diastolic diameter, systolic blood pressure and diastolic blood pressure in groups C and I, and the posterior wall thickness and the end systolic diameter in group I showed no significant difference (P > 0.05). On the other hand, the percentage of ejection fraction and shortening fraction in groups C and I, the end systolic diameter and the posterior wall thickness in group C and the interventricular septum thickness in group I demonstrated a significant difference (P ≤ 0.05). Comparing the two groups, only the value of the interventricular septum thickness was significant (P ≤ 0.05). In general, eight-week aerobic continuous and interval training can affect left ventricular structure and function. 相似文献
3.
T. Kullmer G. Kneissl T. Katova H. Kronenberger A. Urhausen W. Kindermann W. M?rz J. Meier-Sydow 《European journal of applied physiology and occupational physiology》1995,70(2):169-174
To clarify whether or not systolic and diastolic function of the human left ventricle (LV) were decreased during acute hypoxia, at rest and with exercise, 14 healthy male volunteers [age 25.9 (SD 3.0) years, height 182.9 (SD 7.1) cm, body mass 75.9 (SD 6.9)kg] were examined using M-mode and 2D-mode echocardiography to determine the systolic LV function as well as Doppler-echocardiography for the assessment of diastolic LV function on 2 separate test days. In random order, the subjects breathed either air on 1 day (N) or a gas mixture with reduced oxygen content on the other (H; oxygen fraction in inspired gas 0.14). Measurements on either day were made at rest, several times during incremental cycle exercise in a supine position (6-min increments of 50 W, maximal load 150 W) and in 6th min of recovery. Corresponding measurements during N and H were compared statistically. Arterial O2 tension (P
aO2) was normal on N-day. All subjects showed a marked acute hypoxia at rest [P
aO2, 54.5 (SD 4.6) mmHg], during exercise and recovery on H-day. The latter was associated with tachycardia compared to N-day. All echocardiographic measurements at rest were within the limits of normal values on both test days. Ejection time, end-systolic and end-diastolic left ventricular dimensions as well as the thickness of left posterior wall and of interventricular septum showed no statistically significant influence of H either at rest or during exercise. Stroke volume and cardiac output were always higher on H-day, which could be attributed to a slight reduction in end-systolic volume with unaffected end-diastolic volume as well as to increased heart rates. Among the indices of systolic LV function the fractions of thickening in the left ventricular posterior wall and interventricular septum showed no differences between H and N at rest or during exercise. However, fibre shortening, ejection fraction and mean circumferential fibre shortening were increased on H-day on all occasions. The mitral-valve-Doppler ratio, the index of diastolic LV function, was decreased with H at rest, showed a more pronounced reduction during exercise and was still lower in 6th min of recovery compared to N-day. It was concluded that with acute hypoxia of the severity applied in this study left ventricular systolic function in our healthy subjects showed a pronounced improvement and left ventricular diastolic function was reduced, both at rest and with exercise. 相似文献
4.
超声对比剂的使用使得超声诊断更加准确,扩大了超声成像的应用范围。但单一影像技术难以满足肿瘤等重大疾病临床诊断和治疗的需求。因此开发以超声对比剂为核心,具有多模式成像功能,或同时兼备肿瘤诊断和治疗功能的多模式功能化对比剂是目前的一大研究热点。多模式成像的结合可以实现优势互补,诊断和治疗功能的结合为使得肿瘤等重大疾病的解决提供了新理念和新希望,具有重要意义。本文就基于超声的多模式功能化对比剂进行综述。 相似文献
5.
目的:研究心肌造影负荷超声心动图(MCSE)定量心肌血流判断存活心肌的可行性与可靠性。方法:对20例冠心病患者行持续静脉滴注法MCSE,按1:4的比例于收缩末期触发的方式提取图像,采集图像后脱机分析及彩色编码。计算灌注正常区域和灌注缺损区域的A.β值,根据A.β值确定心肌存活与否,将判定结果正电子断层显像(PET)进行对照。结果:17例病人(85%)获得满意图像,灌注正常区和灌注缺损区的A.β值分别为59.32±11.54和5.69±1.78;灌注正常区在Dob 5μg、10μg时的A.β均值分别为69.57±8.13和76.65±13.61,且均高于静息时A.β值,与PET判定坏死的心肌节段一致。结论:MCSE能从血流定量水平判断存活心肌。 相似文献
6.
Miller DL 《Progress in biophysics and molecular biology》2007,93(1-3):314-330
Ultrasound exposure can induce bioeffects in mammalian tissue by the nonthermal mechanism of gas body activation. Pre-existing bodies of gas may be activated even at low-pressure amplitudes. At higher-pressure amplitudes, violent cavitation activity with inertial collapse of microbubbles can be generated from latent nucleation sites or from the destabilization of gas bodies. Mechanical perturbation at the activation sites leads to biological effects on nearby cells and structures. Shockwave lithotripsy was the first medical ultrasound application for which significant cavitational bioeffects were demonstrated in mammalian tissues, including hemorrhage and injury in the kidney. Lithotripter shockwaves can also cause hemorrhage in lung and intestine by activation of pre-existing gas bodies in these tissues. Modern diagnostic ultrasound equipment develops pressure amplitudes sufficient for inertial cavitation, but the living body normally lacks suitable cavitation nuclei. Ultrasound contrast agents (UCAs) are suspensions of microscopic gas bodies created to enhance the echogenicity of blood. Ultrasound contrast agent gas bodies also provide nuclei for inertial cavitation. Bioeffects from contrast-aided diagnostic ultrasound depend on pressure amplitude, UCA dose, dosage delivery method and image timing parameters. Microvascular leakage, capillary rupture, cardiomyocyte killing, inflammatory cell infiltration, and premature ventricular contractions have been reported for myocardial contrast echocardiography with clinical ultrasound machines and clinically relevant agent doses in laboratory animals. Similar bioeffects have been reported in intestine, skeletal muscle, fat, lymph nodes and kidney. These microscale bioeffects could be induced unknowingly in diagnostic examinations; however, the medical significance of bioeffects of diagnostic ultrasound with contrast agents is not yet fully understood in relation to the clinical setting. 相似文献
7.
J. A. van der Heide S. A. Kleijn M. F. A. Aly J. Slikkerveer O. Kamp 《Netherlands heart journal》2011,19(10):423-431
One of the earliest applications of clinical echocardiography is evaluation of left ventricular (LV) function and size. Accurate, reproducible and quantitative evaluation of LV function and size is vital for diagnosis, treatment and prediction of prognosis of heart disease. Early three-dimensional (3D) echocardiographic techniques showed better reproducibility than two-dimensional (2D) echocardiography and narrower limits of agreement for assessment of LV function and size in comparison to reference methods, mostly cardiac magnetic resonance (CMR) imaging, but acquisition methods were cumbersome and a lack of user-friendly analysis software initially precluded widespread use. Through the advent of matrix transducers enabling real-time three-dimensional echocardiography (3DE) and improvements in analysis software featuring semi-automated volumetric analysis, 3D echocardiography evolved into a simple and fast imaging modality for everyday clinical use. 3DE provides the possibility to evaluate the entire LV in three spatial dimensions during the complete cardiac cycle, offering a more accurate and complete quantitative evaluation the LV. Improved efficiency in acquisition and analysis may provide clinicians with important diagnostic information within minutes. The current article reviews the methodology and application of 3DE for quantitative evaluation of the LV, provides the scientific evidence for its current clinical use, and discusses its current limitations and potential future directions. 相似文献
8.
Patrick H. Kee Todd A. Abruzzo Denise A.B. Smith Jonathan A. Kopechek Boyu Wang Shaoling L. Huang 《Journal of liposome research》2013,23(4):263-277
Background: development of encapsulated therapeutics that could be released upon ultrasound exposure has strong implications for enhancing drug effects at the target site. We have developed echogenic liposomes (ELIP) suitable for ultrasound imaging of blood flow and ultrasound-mediated intravascular drug release. Papaverine was chosen as the test drug because its clinical application requires high concentration in the target vascular bed but low concentration in the systemic circulation. Methods: the procedure for preparation of standard ELIP was modified by including Papaverine hydrochloride in the lipid hydration solution, followed by three freeze-thaw cycles to increase encapsulation of the drug. Sizing and encapsulation pharmacokinetics were performed using a Coulter counter and a phosphodiesterase activity assay. Stability of Papaverine-loaded ELIP (PELIP) was monitored with a clinical diagnostic ultrasound scanner equipped with a linear array transducer at a center frequency of 4.5 MHz by assessing the mean digital intensity within a region of interest over time. The stability of PELIP was compared to those of standard ELIP and Optison?. Results: relative to standard ELIP, PELIP were larger (median diameter?=?1.88?±?0.10 μm for PELIP vs 1.08?±?0.15 μm for ELIP) and had lower Mean Gray Scale Values (MGSV) (92?±?24.8 for PELIP compared to 142.3?±?10.7 for ELIP at lipid concentrations of 50 μg/ml). The maximum loading efficiency and mean encapsulated concentration were 24%?±?7% and 2.1?±?0.7 mg/ml, respectively. Papaverine retained its phosphodiesterase inhibitory activity when associated with PELIP. Furthermore, a fraction of this activity remained latent until released by dissolution of liposomal membranes with detergent. The stability of both PELIP and standard ELIP were similar, but both are greater than that of Optison?. Conclusions: our results suggest that PELIP have desirable physical, biochemical, biological, and acoustic characteristics for potential in vivo administration and ultrasound-controlled drug delivery. 相似文献
9.
Wang J Lv F Fei X Cui Q Wang L Gao X Yuan Z Lin Q Lv Y Liu A 《International journal of biological sciences》2011,7(5):600-606
Angiogenesis is a critical factor in tumor growth and metastasis, and microvessel density (MVD) was an important parameter for assessing vessels in tumors. However, radiologic assessment of tumor vascularity is not yet well established. In our study, we aimed at investigating the efficacy of contrast-enhanced ultrasonography (CEUS) in exploring the vascularity of the ovarian tumors or tumor-like lesions to assess the relationship between the parameters of the peak intensity (PI) and area under curve (AUC) on CEUS and MVD in ovarian masses. Compared to the contrast-enhanced ultrasound technique, conventional ultrasound shows limitation in differentiating benign and malignant ovarian tumors. The former is promising in improving the sensitivity of detecting small vessels and blood flow in ovarian tumors. Our results showed clear differences in enhancement patterns between benign and malignant ovary tumors or tumor-like lesions. The PI and AUC in the malignant tumors were significantly higher than those in the benign tumors or tumor-like lesions (p=0.001 and =0.01, respectively). The MVD was 43.1 ± 20.4 in the benign tumors or tumor-like lesions and was 65.3 ± 22.3 in the malignant ones (p= 0.01). In both the benign and malignant groups, the PI and AUC were correlated significantly with the MVD (r=0.595, p = 0.001; r =0.533, p = 0.003, respectively). The PI and AUC in CEUS can reflect the MVD in ovarin tumors. The PI and AUC of the ovarian masses in the contrast transvaginal sonography show significant correlation with the angiogenesis and may help in assessing tumor vascularity in ovarian masses. 相似文献
10.
BACKGROUND: Achieving specificity of delivery represents a major problem limiting the clinical application of retroviral vectors for gene therapy, whilst lack of efficiency and longevity of gene expression limit non-viral techniques. Ultrasound and microbubble contrast agents can be used to effect plasmid DNA delivery. We therefore sought to evaluate the potential for ultrasound/microbubble-mediated retroviral gene delivery. METHODS: An envelope-deficient retroviral vector, inherently incapable of target cell entry, was combined with cationic microbubbles and added to target cells. The cells were exposed to pulsed 1 MHz ultrasound for 5 s and subsequently analysed for marker gene expression. The acoustic pressure profile of the ultrasound field, to which transduction efficiency was related, was determined using a needle hydrophone. RESULTS: Ultrasound-targeted gene delivery to a restricted area of cells was achieved using virus-loaded microbubbles. Gene delivery efficiency was up to 2% near the beam focus. Significant transduction was restricted to areas exposed to > or = 0.4 MPa peak-negative acoustic pressure, despite uniform application of the vector. An acoustic pressure-dependence was demonstrated that can be exploited for targeted retroviral transduction. The mechanism of entry likely involves membrane perturbation in the vicinity of oscillating microbubbles, facilitating fusion of the viral and cell membranes. CONCLUSIONS: We have established the basis of a novel retroviral vector technology incorporating favourable aspects of existing viral and non-viral gene delivery vectors. In particular, transduction can be controlled by means of ultrasound exposure. The technology is ideally suited to targeted delivery following systemic vector administration. 相似文献
11.
The development of ultrasound has created great opportunities for diagnostic cardiac imaging. For more than 30 years, echocardiography has been the most important and cost-effective diagnostic imaging modality in clinical cardiology. Many developments originated in the Netherlands, including the very first practical real-time crosssectional imaging of the moving heart with a linear array. Milestones include the first portable echo apparatus, early versions of echo catheters and transoesophageal echocardiography probes as well as many clinical ‘firsts’ with reference to the more than 100 Dutch dissertations related to echocardiography. The future of echocardiography promises to be as productive and exciting as it has been in the previous three decades, including threedimensional echocardiography, myocardial perfusion echocardiography, tissue Doppler imaging and speckle tracking. New potential therapeutic applications are upcoming. In this article, the advances of echocardiography in the Netherlands are described, in the past and during 30 years of education, as was recently presented by three Dutch pioneers during the ‘Echomiddagen 2006-2007’ organised by the CVOI. (Neth Heart J 2008;16: 16-20.) 相似文献
12.
《现代生物医学进展》2024,(24):4743-4745
摘要 目的:探讨经胸超声心动图(TTE)与经胸右心声学造影(c-TTE)诊断卵圆孔未闭(PFO)所致偏头痛以及右向左分流(RLS)的价值。方法:选择82例疑似PFO所致的偏头痛患者,所有患者均接受TTE和c-TTE检查,以数字减影血管造影(DSA)结果为金标准,采用Kappa系数检验TTE、c-TTE与DSA检查结果的一致性,采用四格表法和受试者工作特征(ROC)曲线分析TTE、c-TTE诊断PFO所致偏头痛及RLS的效能。结果:82例偏头痛患者中,经DSA检查确诊60例PFO。TTE共检出42例PFO,与DSA诊断结果一致性一般(Kappa=0.294,P<0.05);c-TTE共检出57例PFO,与DSA诊断结果一致性很强(Kappa=0.879,P<0.05)。TTE共检出36例RLS,与DSA诊断结果一致性一般(Kappa=0.260,P<0.05);c-TTE共检出53例RLS,与DSA诊断结果一致性较强(Kappa=0.706,P<0.05)。与TTE相比,c-TTE诊断PFO的灵敏度、特异度、准确度、阳性预测值、阴性预测值均更高(Z=4.889,P<0.05)。与TTE相比,c-TTE诊断RLS的灵敏度、特异度、准确度、阳性预测值、阴性预测值均更高(Z=4.412,P<0.05)。结论:相对于TTE,c-TTE可更加灵敏、准确地诊断PFO及RLS分级,在PFO所致偏头痛患者中具有更高的诊断价值。 相似文献
13.
目的:探讨高强度聚焦超声(high intensity focused ultrasound,HIFU)治疗子宫肌瘤的临床疗效及其安全性。方法:回顾性分析我院2007年1月~2011年1月300例采用高强度聚焦超声治疗的子宫肌瘤患者的临床资料,比较分析治疗前后瘤体大小、病灶内部回声、临床症状改善情况、血流的变化及超声造影图像改变。结果:HIFU治疗后1、3、6及12个月,瘤体体积均较治疗前显著缩小(P〈0.05),显效率80.33%(241例),有效率19.33%(58例),无效率0.33%(1例),肌瘤所致的临床症状减轻或消失,瘤体内部回声增强,彩色血流均消失,超声造影瘤体内无灌注。治疗期间,患者出现治疗部位疼痛、骶尾部酸胀及肛门坠胀,治疗结束时症状消失;治疗过程中出现腿部疼痛、麻木症状,经过重新定位后症状消失,少数出现阴道少量流血,给予止血药;治疗后出现血尿,经大量喝水排尿后消失。结论:HIFU治疗子宫肌瘤是安全有效的,在妇科领域便于推广。 相似文献
14.
J. M. HASTINGS K. D. MORRIS D. ALLAN H. WILSON R. P. MILLAR H. M. FRASER C. M. MORAN 《American journal of primatology》2012,74(12):1088-1096
The development of a functional vascular tree within the primate ovary is critical for reproductive health. To determine the efficacy of contrast agents to image the microvascular environment within the primate ovary, contrast ultrasonography was performed in six reproductive‐aged female common marmosets (Callithrix jacchus) during the late luteal phase of the cycle, following injection of Sonovue?. Regions of interest (ROIs), representing the corpus luteum (CL) and noncorpus luteum ovarian tissue (NCLOT), were selected during gray‐scale B‐mode ultrasound imaging. The magnitude of backscatter intensity of CL and NCLOT ROIs were calculated in XnView, post hoc: subsequent gamma‐variate modeling was implemented in Matlab to determine perfusion parameters. Histological analysis of these ovaries revealed a total of 11 CL, nine of which were identified during contrast ultrasonography. The median enhancement ratio was significantly increased in the CL (5.54AU; 95% CI ?2.21–68.71) compared to the NCLOT (2.82AU; 95% CI 2.73–15.06; P < 0.05). There was no difference in time parameters between the CL and NCLOT. An additional avascular ROI was identified in the ovary of Animal 5, both histologically and by ultrasonography. This cystic ROI displayed a markedly lower enhancement ratio (0.79AU) and higher time parameters than mean CL and NCLOT, including time to peak and time to wash out. These data demonstrate, for the first time, the ability of commercially available contrast agents, to differentiate structures within the nonhuman primate ovary. Contrast‐enhanced ultrasonography has a promising future in reproductive medicine. Am. J. Primatol. 74:1088‐1096, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
15.
Longling Fan Jing Yao Chun Yang Di Xu Dalin Tang 《Molecular & cellular biomechanics : MCB》2016,13(1):33-55
Modeling ventricle active contraction based on in vivo data is extremely challenging because of complex ventricle geometry, dynamic heart motion and active contraction where the reference geometry (zero-stress geometry) changes constantly. A new modeling approach using different diastole and systole zero-load geometries was introduced to handle the changing zero-load geometries for more accurate stress/strain calculations. Echo image data were acquired from 5 patients with infarction (Infarct Group) and 10 without (Non-Infarcted Group). Echo-based computational two-layer left ventricle models using one zero-load geometry (1G) and two zero-load geometries (2G) were constructed. Material parameter values in Mooney-Rivlin models were adjusted to match volume data. Effective Young’s moduli (YM) were calculated for easy comparison. For diastole phase, begin-filling (BF) mean YM value in the fiber direction (YMf) was 738%higher than its end-diastole (ED) value (645.39 kPa vs. 76.97 kPa, p=3.38E-06). For systole phase, end-systole (ES) YMf was 903% higher than its begin-ejection (BE) value (1025.10 kPa vs. 102.11 kPa, p=6.10E-05). Comparing systolic and diastolic material properties, ES YMf was 59% higher than its BF value (1025.10 kPa vs. 645.39 kPa. p=0.0002). BE mean stress value was 514% higher than its ED value (299.69 kPa vs. 48.81 kPa, p=3.39E-06), while BE mean strain value was 31.5% higher than its ED value (0.9417 vs. 0.7162, p=0.004). Similarly, ES mean stress value was 562% higher than its BF value (19.74 kPa vs. 2.98 kPa, p=6.22E-05), and ES mean strain value was 264% higher than its BF value (0.1985 vs. 0.0546, p=3.42E-06). 2G models improved over 1G model limitations and may provide better material parameter estimation and stress/strain calculations. 相似文献
16.
S. Rasoul J-H.E. Dambrink A. Breeman A. Elvan A.W.J. van ’t Hof 《Netherlands heart journal》2010,18(1):25-30
Background. Myocardial blush grade (MBG) and myocardial contrast echocardiography (MCE) are both indices for myocardial perfusion in patients with ST-elevation acute myocardial infarction (STEMI). We aimed to compare MBG with MCE in the infarct-related artery segment for assessing infarct size in patients with STEMI treated with primary percutaneous coronary intervention (PCI).Methods. 43 patients underwent successful (postprocedural TIMI flow 3) primary PCI for STEMI. MBG was assessed at the end of the PCI procedure and MCE was assessed 1.7±1.8 days after PCI. Enzymatic infarct size was estimated by measurementof enzyme activities by using lactate dehydrogenase (LDH) as the referenceenzyme. Cumulative enzyme release (LDHQ48) from at least five serial measurements up to 48 hours after symptom onset was calculated. Also peak creatine kinase, CK-MB and peak LDH were measured.Results. MBG 0/1, 2 and 3 were observed in 14, 12 and 17 patients, respectively, and was compared with tertiles of MCE. We found a parallel correlation between both MBG and MCE and LDHQ48. However, there was no correlation between MCE and MBG. Patients with both normal MCE and a normal MBG had least myocardial damage and those with both impaired MCE and an impaired MBG had most myocardial damage.Conclusion. Both MBG and MCE are good predictors of infarct size in STEMI patients treated with PCI. However, these markers are not mutually related, possibly due to time-related changes in myocardial perfusion. Combining these two markers may yield a more accurate prediction of final myocardial damage. (Neth Heart J 2010;18:25-30.) 相似文献
17.
三维超声心脏图像的模糊聚类分割 总被引:3,自引:0,他引:3
采用三维超声心动图对小儿先天性心脏病进行诊断与治疗能达到比传统二维超声心动图更直观的效果。然而由于超声图像质量较差,三维超声心动图的可视化效果往往无法达到医生的要求。本文对三维超声心脏图像进行分割,以改进超声图像的可视化效果,并为参数提取等提供基础。首先采用快速的模糊c均值聚类得到初始分割结果;然后利用图像多分辨率技术进行修正;接着结合图像的对比度进行进一步的分割;最后,把处理后的图像用绘制的方法显示出来。本文的结果对超声图像的可视化效果有一定的改善. 相似文献
18.
Rahim AA Taylor SL Bush NL ter Haar GR Bamber JC Porter CD 《The journal of gene medicine》2006,8(11):1347-1357
BACKGROUND: Ultrasound/microbubble-mediated gene delivery has the potential to be targeted to tissue deep in the body by directing the ultrasound beam following vector administration. Application of this technology would be minimally invasive and benefit from the widespread clinical experience of using ultrasound and microbubble contrast agents. In this study we evaluate the targeting ability and spatial distribution of gene delivery using focused ultrasound. METHODS: Using a custom-built exposure tank, Chinese hamster ovary cells in the presence of SonoVue microbubbles and plasmid encoding beta-galactosidase were exposed to ultrasound in the focal plane of a 1 MHz transducer. Gene delivery and cell viability were subsequently assessed. Characterisation of the acoustic field and high-resolution spatial analysis of transfection were used to examine the relationship between gene delivery efficiency and acoustic pressure. RESULTS: In contrast to that seen in the homogeneous field close to the transducer face, gene delivery in the focal plane was concentrated on the ultrasound beam axis. Above a minimum peak-to-peak value of 0.1 MPa, transfection efficiency increased as acoustic pressure increased towards the focus, reaching a maximum above 1 MPa. Delivery was microbubble-dependent and cell viability was maintained. CONCLUSIONS: Gene delivery can be targeted using focused ultrasound and microbubbles. Since delivery is dependent on acoustic pressure, the degree of targeting can be determined by appropriate transducer design to modify the ultrasound field. In contrast to other physical gene delivery approaches, the non-invasive targeting ability of ultrasound makes this technology an attractive option for clinical gene therapy. 相似文献
19.
目的:调查与分析四维子宫输卵管超声造影假阳性与假阴性的原因.方法:选择2015年6月到2019年8月在本院妇产科临床初步诊断为输卵管不孕症患者125例,所有患者都给予X线子宫输卵管碘油造影(Hysterosalp ingography,HSG)与四维子宫输卵管超声造影,记录诊断效果、不良反应,判断假阳性与假阴性的发生原... 相似文献
20.
Wynter J. Duncanson Kelleny Oum John R. Eisenbrey Robin O. Cleveland Margaret A. Wheatley Joyce Y. Wong 《Biotechnology and bioengineering》2010,106(3):501-506
In order for site‐directed polymer ultrasound contrast agents (UCAs) to provide acoustic enhancement at disease sites to distinguish normal tissue from diseased tissue, the surface of these agents must be functionalized with mixtures of grafted polymers. Here a combination of longer liganded polyethylene glycol (PEG)‐lipids and shorter unliganded PEG‐lipids were introduced into the oil phase of a modified solvent evaporation double emulsion method for preparing UCAs. UCAs with different lengths of both liganded and unliganded lipids were imaged under 7.5 MHz ultrasound. The B‐mode image brightness of the mixed PEG‐lipid UCAs was within 1 dB the brightness of the unliganded surface. After 15 min of continuous insonation, 70% of the contrast signal remained. The peptide arginine–glycine–aspartic acid (RGD) was added to the surface of these UCAs through a biotin–avidin linkage and binding was assessed under static and shear conditions. Binding was significant after 30 min of static incubation and the adherence of the UCA increased under shear flow from 3 UCA/cell (static) to 5 UCA/cell (shear). Biotechnol. Bioeng. 2010; 106: 501–506. © 2010 Wiley Periodicals, Inc. 相似文献