低频超声对卵巢癌细胞的生物学效应

目的　研究低频超声对体外培养的人卵巢癌细胞的急、慢性生物学效应。方法　人卵巢癌细胞 3AO受不同剂量、频率为 0 .2 4MHz超声波辐照 ,根据剂量 -效应曲线确定两种不致细胞急性损伤的声波剂量 ,观察受此两种剂量超声处理后细胞的增殖能力和克隆形成力的变化。结果　 3 .92W /cm2 × 10s和 5 .12W /cm2 × 5s未致细胞急性死亡。受 3 .92W /cm2 × 10s、5 .12W /cm2 × 5s辐照和对照组细胞倍增时间分别为 45 .2h、3 4 .4h和 2 8.6h ,克隆形成率分别为 2 1.3 %、5 0 .3 %和 46.0 % ,受 3 .92W /cm2 × 10s辐照细胞增殖和克隆形成均受到抑制 (P值均 <0 .0 1)。结论　 3AO对超声的敏感性较高 ,超声的迟发效应更决定于辐照持续时间。     

低频超声联合盐酸氨溴索对表皮葡萄球菌生物被膜的影响

目的 研究低频超声联合盐酸氨溴索对表皮葡萄球菌(Sepidermidis)RP62A生物被膜(biofilm,BF)结构的影响.方法 建立成熟RP62A BF模型.分组处理,XTT法测BF细菌活性变化;激光共聚焦显微镜结合ISA软件定量分析BF;扫描电镜观察BF结构改变.结果 单独低频超声作用BF无效果,1.875 mg/mL浓度氨溴索能有效清除BF,较空白对照组区域孔率增大,平均扩散距离和结构熵减小,P＜0.05;氨溴索联合低频超声(1、0.5h)组效果更加显著,与单独氨溴索组相比,P＜0.05;扫描电镜显示低频超声能明显促进氨溴索对BF的作用,使BF变薄,结构趋于单一疏松.结论 低频超声能显著促进氨溴索对表皮葡萄球菌BF的清除作用.     

低频超声对大鼠主动脉平滑肌细胞凋亡的作用

目的观察低频超声波对体外培养的大鼠主动脉平滑肌细胞（VSMCs）凋亡的影响。方法42.6kHz超声辐照大鼠主动脉平滑肌细胞,台盼蓝染色分析辐照后即刻细胞存活率,流式细胞仪观察24小时后细胞凋亡。结果低频超声辐照可以诱导培养的VSMCs凋亡,该作用在50秒内随辐照时间的增加有增加的趋势。结论低频超声在无明显杀伤细胞的情况下可在短时间内诱导培养的VSMCs凋亡,提示低频超声是一种潜在的治疗PCI术后再狭窄的手段。     

低频脉冲超声与关节软骨损伤修复

外伤或疾病所致的关节软骨损伤在临床上十分常见。由于软骨组织自身修复能力很差,关节软骨损伤后的修复一直是骨科、矫形外科及运动医学界的难点。近年来人们发现低频脉冲超声辐照对损伤软骨具有促修复作用,可望发展成为一种极具应用前景的促进关节软骨损伤修复的新手段。本文拟就关节软骨损伤修复的研究概况及低频脉冲超声辐照在关节软骨损伤修复中的作用做一扼述和探讨。     

低频超声终止妊娠作用机制研究

目的：探讨低频超声终止兔妊娠的机制及对胚胎组织的影响。方法：应用220KHz,9W／cm^2超声处理126只兔胚胎,超声辐照时间及例数分别为3分钟20只,5分钟20只,7分钟20只,10分钟40只,15分钟26只,其它频率超声处理胚胎60只。于超声处理前后分别测试胚胎温度变化并对超声处理的胚胎胎盘进行病理学检查。结果：220KHz,9W/cm^2超声辐照胚胎组织时间不超过10分钟时,胚胎温度均不超过40℃。幅照7分钟,胎盘血管破裂;幅照10分钟。胎盘与子宫壁间出血和出现间隙,台盘与子宫壁分离,胎盘细胞内未见明显空泡。结论：220KHz,9W/cm^2超声幅照胚胎7－10分钟,可主要通过机械效应而终止妊娠。     

高强度聚焦超声对大鼠坐骨神经组织学影响的实验研究

目的 应用高强度聚焦超声(HIFU)辐照大鼠坐骨神经干,观察辐照后神经的组织学变化,为HIFU在周围神经领域的应用提供实验基础.方法 健康雄性SD大鼠24只,随机分为辐照1 min(相对低剂量)和辐照2 min(相对高剂量)两组,每组12只,以左侧股骨大转子后0.5 cm为中心,取其周围1 cm区域为辐照靶区,用HIFU进行辐照.辐照后于靶区内取长1 cm的坐骨神经及周围组织行HE染色和masson染色光镜下观察,右侧相应部位作为对照.结果 对照组神经纤维呈现正常的组织形态;辐照1 min病变轻微,部分神经纤维出现轴突断裂、轴突空泡,髓鞘裂解脱失;辐照2 min病变严重,大量神经纤维轴突变性、出现大量空泡,髓鞘裂解脱失、施万细胞裂解坏死.此外,两辐照组的周围组织未见明显病理改变.结论 该实验显示神经组织在不同剂量的HIFU作用下可出现部分或完全损伤,甚至是不可逆坏死.因此,HIFU有望成为一种治疗慢性神经病理性疼痛的新方法.     

诊断超声对大鼠胚胎脂质过氧化的近期和远期影响

本文观察了诊断超声辐照对大鼠胚胎脂质过氧化（ＬＰＯ）的近期和远期影响。将孕１３日龄（１３ＧＤ）鼠胚胎持续宫内超声辐照３０分钟，分别于孕１４、１６、１８及２１日龄取鼠胚胎或胎肝组织测定ＬＰＯ各指标，并与同孕龄对照组进行比较。结果表明：超声辐照后孕１４日龄鼠胚胎组织ＭＤＡ含量增加（Ｐ〈０．０５），ＳＯＤ活性降低（Ｐ〈０．０５），我们认为与超声空化产生的自由基、脂质过氧化有关。而上述改变在超声辐照后７２     

低频超声联合环丙沙星对铜绿假单胞菌生物被膜的杀菌作用及其结构的影响

目的 研究低频超声联合环丙沙星对铜绿假单胞菌PAO1菌株生物被膜(biofilm,BF)的杀菌作用及其结构的影响.方法 建立PAO1菌株BF模型,设空白对照组,低频超声组,环丙沙星组,环丙沙星+低频超声组(超声辐射前给药),低频超声+环丙沙星组(超声辐射后给药),XTT比色法测定BF细菌活力的变化;激光共聚焦显微镜观察并结合图像结构分析软件对BF结构进行定量分析;扫描电镜观察BF结构的改变.结果 环丙沙星+低频超声组和低频超声+环丙沙星组BF细菌活力明显降低,BF厚度变薄,区域孔径增大,平均扩散距离与结构熵减小,与空白对照组、低频超声组、环丙沙星组比有显著性差异(P＜0.05);扫描电镜显示,低频超声联合环丙沙星对BF清除明显.结论 低频超声联合环丙沙星对PAO1菌株BF有很好的杀菌作用,且能破坏其结构.     

低频超声的作用和研究前景

概述了低频超声的生物学作用机理和特点,临床治疗中的应用情况,及对进一步研究的 展望。     

低频超声心肌消融的生物学效应

目的：探讨低频超声心肌消融用以治疗心律失常的可行性及副作用。方法：以３４ＫＨｚ连续波超声作用于活体兔外膜心肌,记录工作中心肌细胞动作电位的变化及结构变化。结果：超声处理后心肌未见搏动及传导异常,经８Ｗ／ｃｍ超声消融后心肌细胞静息电位水平明显提高,０相最大除极速度及动作电位幅度明显降低。以２６Ｗ／ｃｍ声强消融后跨膜动作电位消失。观察发现消融近端心肌凝固样坏死,内膜心肌（距外膜４～６ｍｍ）细胞器空化、破坏及肌丝溶解。结论：低频超声可有效消融心肌,损伤心肌有潜在致心律失常的基础     

Upgraded Nerve Growth Factor Expression Induced by Low-Intensity Continuous-Wave Ultrasound Accelerates Regeneration of Neurotometicly Injured Sciatic Nerve in Rats

Low-intensity ultrasound (LIU) can stimulate injured nerve regeneration but the mechanism is still unclear. We investigated the stimulating effect and its mechanism of continuous-wave LIU on neurotometic injury of sciatic nerve. The right sciatic nerves of 64 adult Wistar rats were first crushed and then exposed (32 rats) or sham-exposed (32 rats) to LIU at the crush site. The LIU had a spatial averaged and temporal averaged intensity of 0.25W/cm² operated at 1.0 MHz for 1 min every other day. At various stages (the second, fourth, sixth and eighth weeks) after LIU exposure, the sciatic nerve function index (SFI), the sensory nerve conduction velocity (SNCV), the expression of nerve growth factor (NGF) and sample histology were studied. It was found that the density of nerve fibers with myelin sheath, SFI, SNCV and NGF expression of the treatment group were higher than that of control group (p < 0.05). It has been determined that LIU treatment can accelerate the regeneration and functional recovery of neurotometic injured sciatic nerve at earlier stages after injury, the upgraded expression of NGF induced by LIU may be the primary mechanism of the acceleration effects. (E-mail: wangzhibiao@haifu.com.cn)     

The Effect of Low-Intensity Ultrasound on Brain-Derived Neurotropic Factor Expression in a Rat Sciatic Nerve Crushed Injury Model

Low-intensity ultrasound (LIU) can improve nerve regeneration and functional recovery after peripheral nerve crush injury, but the underlying mechanism is not clear. The objective of this study was to examine the effects of LIU on rat sciatic crush injury and to investigate a possible molecular mechanism. Adult male Sprague-Dawley rats underwent left sciatic nerve crush surgery and were then randomized into two groups: a treatment group that received LIU every other d, and a control group that received sham exposure. Compared with rats in the control group, rats in the treatment group had higher sciatic nerve function indexes, compound muscle action potentials, wet weight ratios of the target muscle and mRNA expression of brain-derived neurotropic factor (BDNF) in the crushed nerve and ipsilateral dorsal root ganglia. Our findings suggest that LIU might promote injured nerve regeneration by stimulating BDNF release.     

Fibronectin促进周围神经再生的实验研究

目的：探讨局部应用Fibronectin（FN）对周围神经再生的影响。方法：将34只SD大鼠分为4组,1～3组每组10只,手术切除双侧10mm坐骨神经并用硅胶管套接,左侧套管内注入FN10μg;右侧注入生理盐水作为对照。术后1、3、4个月分别进行电生理和组织学检查。第4组另4只鼠于术后3个月行辣根过氧化物酶（HRP）逆行示踪检查。结果：FN治疗组术后1、3、4个月时的电生理和形态学检查结果均明显优于对照组。术后HRP逆行示踪检查发现相应节段的治疗组脊髓前角和背根神经节标记神经元明显多于对照组。结论：FN可促进周围神经损伤后的再生。     

Focused Ultrasound Effects on Nerve Action Potential in vitro

Minimally invasive applications of thermal and mechanical energy to selective areas of the human anatomy have led to significant advances in treatment of and recovery from typical surgical interventions. Image-guided focused ultrasound allows energy to be deposited deep into the tissue, completely noninvasively. There has long been interest in using this focal energy delivery to block nerve conduction for pain control and local anesthesia. In this study, we have performed an in vitro study to further extend our knowledge of this potential clinical application. The sciatic nerves from the bullfrog (Rana catesbeiana) were subjected to focused ultrasound (at frequencies of 0.661MHz and 1.986MHz) and to heated Ringer's solution. The nerve action potential was shown to decrease in the experiments and correlated with temperature elevation measured in the nerve. The action potential recovered either completely, partially or not at all, depending on the parameters of the ultrasound exposure. The reduction of the baseline nerve temperature by circulating cooling fluid through the sonication chamber did not prevent the collapse of the nerve action potential; but higher power was required to induce the same endpoint as without cooling. These results indicate that a thermal mechanism of focused ultrasound can be used to block nerve conduction, either temporarily or permanently. (E-mail: khynynen@sri.utoronto.ca)     

超声对鼠周围神经损伤后肌肉神经再支配作用的研究

为探讨超声有否促进周围神经再生及肌肉神经再支配的作用，我们对大鼠腓神经实行钳夹损伤造模并进行超声治疗４天。通过测量趾长伸肌收缩张力曲线及对神经、肌肉标本进行光镜、电镜和组织化学检查，结果表明超声能促进周围神经再生及肌肉神经再支配。     

高强度超声对兔外周神经传导速度影响的观察

目的　观察高强度超声 (highintensityultrasound ,HIU)作用于兔坐骨神经干后 ,其神经生理变化及转归 ,为超声在治疗临近大神经的器官、组织病变时 ,提供神经保护相关的实验依据。方法　以不同的HIU剂量 (强度×时间 )辐照兔坐骨神经干 ,然后分别于不同时间点观察从辐照点近端到远端踝部胫神经、腓浅神经电生理指标 (传导速度、动作电位幅值、潜伏期 )变化。结果　坐骨神经受HIU辐照后神经电生理出现不同程度改变 ,变化程度与剂量大小有关。剂量小 ,传导轻微减慢 ,剂量大 ,传导明显减慢甚至完全阻滞 ;损伤后的恢复与损伤程度有关 ,损伤轻 ,恢复快而完全 ,损伤重 ,难以恢复。结论　坐骨神经受损伤程度与剂量大小有关 :剂量小 ,损伤轻 ;剂量大 ,损伤重。在一定剂量范围内 ,受损神经可以完全恢复 ;剂量过大 ,受损神经难以恢复。     

Applications of Exogenous Mesenchymal Stem Cells and Low Intensity Pulsed Ultrasound Enhance Fracture Healing in Rat Model

The present study aimed to investigate the effects of combined treatment of exogenous mesenchymal stem cells (MSCs) and low intensity pulsed ultrasound (LIPUS) on fracture healing by comparing LIPUS-MSC, MSC and control (CTL) groups. Radiography and quantitative callus width/area demonstrated that the MSC-LIPUS group had the best healing, MSC group the second and CTL group the poorest with significant differences among each at different time points. Micro-CT data supported that MSC-LIPUS had the highest bone volume/tissue volume. Histomorphometry showed a significantly faster remodeling in late phase in MSC-LIPUS and MSC groups. These indicated that the combined treatment of MSCs and LIPUS was beneficial to fracture healing. Regenerative power and homing ability of MSCs were shown by promotion in fracture healing and locally found green fluorescent protein (GFP)-labeled MSCs at fracture calluses. This evidence reflects that co-treatment of MSCs and LIPUS may be developed as an intervention for delayed union or nonunion.     

超声造影分析二乙基亚硝胺诱发性大鼠肝癌模型的实验研究

目的探讨超声造影评估二乙基亚硝胺诱发性大鼠肝癌模型的可行性。方法20只雄性Wistar大鼠采用30mg/kg腹腔注射二乙基亚硝胺。第14周开始每周轮流抽取5只大鼠进行超声检查,发现肝脏结节的大鼠,进行超声造影(CEUS)检查。检查后处死取标本进行病理诊断。结果大鼠超声检查前死亡率45%(9/20),肝癌造模成功率80%(16/20)。肝细胞癌(HCC)病灶超声检出率72.5%(29/40)。55.2%(16/29)HCC病灶呈“高回声增强-无廓清”为主要CEUS增强模式。结论此动物肝癌模型成瘤率较高,CEUS可用于此模型的评估。