超声辐照瘤内注射微泡空化效应的病理学研究

目的探讨超声辐照瘤内注射微泡引起的生物学效应。 方法将12只已建立24个Walker-256皮下移植瘤模型的SD大鼠随机分3组，A组超声监视下瘤内注射超声微泡，并用频率1MHz，强度2．0w／cm^2的超声辐照10min，B组单纯采用同等超声辐照相同时间，C组单纯瘤内注射超声微泡。各组作用后1h取肿瘤组织，HE染色观察病理改变以及用透射电镜硝酸镧示踪法观察边缘瘤组织细胞膜通透性的变化。 结果A组光镜可见大片肿瘤细胞凝固性坏死，电镜可见镧颗粒不但进入细胞间隙而且进入细胞内、以及血管内皮细胞连接。B、C组光镜均未见坏死，电镜B组偶可见少量镧颗粒进入细胞内，C组仅见镧颗粒分布于细胞间隙。 结论瘤内注射超声微泡联合超声辐照可增加细胞膜通透性并引起部分瘤细胞坏死。     

诊断超声介导微泡提高肝纤维化通透性及促进基因传递

目的 探讨诊断超声联合微泡对肝纤维化组织通透性的影响及其介导基因转染肝纤维化大鼠的有效性。方法 采用二甲基亚硝胺(DMN)法建立大鼠肝纤维化模型,80只大鼠在建模第4周末随机分为:模型对照组、单纯微泡组、单纯超声组和诊断超声联合微泡组。分别进行肝纤维化微血管通透性实验和基因转染实验,采用激光共聚焦显微镜观察伊文思蓝(EB)在肝纤维化组织内分布情况,同时定量检测肝纤维化组织内EB的含量,评估不同分组微血管通透性。荧光显微镜下观察含增强型绿色荧光蛋白报告基因的质粒转染大鼠肝纤维化模型的基因表达情况。结果 激光共聚焦显微镜显示诊断超声联合微泡组纤维化肝实质内可见明显的EB红色荧光。诊断超声联合微泡组纤维化肝组织中EB含量明显高于其他3组(P<0.05)。荧光显微镜下观察,相比其余3组,诊断超声联合微泡组增强型绿色荧光蛋白最多,基因转染效率最高。结论 诊断超声联合微泡在提高纤维化肝脏微血管通透性的同时可促进基因传递。     

不同参数对低频诊断超声联合微泡下肝血管通透性影响的研究

目的 探讨不同低频诊断级超声参数联合微泡对正常肝血管通透性的影响,优化超声参数以实现肝血管高通透性,减少对正常肝细胞的影响.方法 使用低频诊断超声辐照造影剂显影的肝脏,按实验分组设置不同水平的辐照时间、机械指数( mechanical index,MI)、微泡剂量,经大鼠尾静脉注入50 mg/kg伊文氏蓝(Evens blue,EB).观察辐照后肝组织中EB渗出情况,定量检测肝组织中EB含量的改变以探索不同参数条件下肝血管通透性的变化,同时对肝脏进行组织学检查观察细胞损伤情况.结果 随着辐照时间的延长、MI的升高、微泡浓度的增加,肝组织中EB含量均有明显增加;HE染色检测肝细胞无明显损伤.结论 低频诊断超声联合微泡可增加肝脏血管通透性,辐照时间、机械指数、微泡浓度是其重要影响因素.     

超声声致孔隙效应增强兔前列腺组织通透性的研究

目的 探讨超声联合造影剂微泡的超声声致孔隙效应开放血-前列腺屏障,提高前列腺组织通透性的可行性.方法 15只健康8月龄性成熟新西兰兔,随机分为单纯微泡组、单纯超声组、超声联合微泡辐照组,超声直接辐照前列腺,荧光显微镜、体视显微镜、伊文思蓝(EB)示踪观察前列腺组织通透性的变化.结果 体视显微镜下超声联合微泡辐照组前列腺组织可见蓝色EB分布于前列腺包膜,部分EB渗透到腺体实质,腺体呈均匀蓝染,单纯超声组及单纯微泡组EB均分布于包膜,腺体实质部分渗透不明显.单纯超声组、单纯微泡组、超声联合微泡辐照组前列腺冰冻切片均可见红色EB荧光分布;经苏木素复染后可见超声联合微泡辐照组腺体管腔内有EB荧光,而单纯超声组、单纯微泡组均未见管腔内红色EB荧光;超声联合微泡辐照组前列腺EB平均浓度较单纯超声组、单纯微泡组高,差异有统计学意义(P<0.01),单纯微泡组及单纯超声组EB浓度均值未见显著差异(P>0.05).结论 超声联合造影剂微泡的超声声致孔隙效应可以有效开放血-前列腺屏障,明显提高兔前列腺组织通透性.     

超声微泡造影剂对心肌组织毛细血管通透性的影响实验研究

目的　研究超声破坏微泡造影剂对靶区内心肌组织毛细血管通透性的影响 ;探讨超声微泡造影剂增强基因转染的机制。方法　 2 4只健康雄性 Wistar大鼠 ,取 15只分为 3组 ,第 1组经静脉输入含有伊文思蓝 (Evans blue,EB)的微泡造影剂 ,并采用超声波在鼠胸壁辐照约 6 min破坏心肌组织内造影剂 ;第 2组采用超声照射 ,同时经静脉单纯输入 EB溶液 ;第 3组单纯经静脉输入 EB作为对照。照射完毕 2 h后放血处死大鼠 ,使用标准曲线和分光光度法测量各组大鼠心肌组织中 EB含量 (作为反映血管通透性的指标 )。另 9只大鼠随机分为 3组 ,每组 3只。第 1组经静脉输入微泡造影剂 ,并采用超声波在鼠胸壁辐照约 6 min破坏心肌组织内造影剂 ;第 2组单纯采用超声照射 ;第 3组不加任何处理 ,作为对照。照射完毕即刻处死大鼠 ,取心肌组织进行电镜观察毛细血管的改变。结果　采用超声照射 ,并经静脉输入微泡造影剂的大鼠 ,心肌组织中 EB含量为 (75 .33± 16 .80 )μg/ g,比单纯超声照射[(32 .2 1± 9.5 3)μg/ g]及心肌正常组织 EB含量 [(37.16± 7.98)μg/ g]明显增加 (P<0 .0 5 )。电镜结果显示超声破坏微泡后 ,能使毛细血管破裂 ,红细胞溢出于毛细血管外。结论　超声波触发破坏微泡造影剂后能使心肌组织毛细血管通透性增加 ,可     

实时三维诊断超声激励瘤内注射微泡增强兔VX2移植瘤化疗效果

目的 探讨实时三维诊断超声激励瘤内注射微泡增强VX2移植瘤化疗效果的价值。方法 将24个兔VX2移植瘤模型随机分为4组,每组6只,分别为空白对照组(A组)、单纯多柔比星(Dox)组(B组)、实时三维诊断超声+微泡组(C组)、实时三维诊断超声+微泡+Dox组(D组)。对实验兔静脉注射Dox 1.2 ml/kg,瘤内注射微泡、约为肿瘤体积的1/2,辐照时间为20 min,机械指数(MI)1.3。于第1、3、5、8天对每组肿瘤进行治疗,共治疗4次。治疗后第10天剥离肿瘤,计算各组肿瘤体积总体生长率。结果 治疗后第10天,D组肿瘤体积明显小于其余3组(P<0.05);4组肿瘤体积总体生长率分别为A组100%,B组15.11%,C组118.22%,D组-30.81%。D组肿瘤体积在治疗后1~3天内略有增大,之后明显下降。结论 实时三维诊断超声激励瘤内注射微泡联合静脉注射Dox能够明显抑制兔VX2移植瘤的生长。     

低频超声微泡抑制裸鼠卵巢癌皮下移植瘤生长的初步研究

目的探讨低频超声联合微泡造影剂对裸鼠皮下卵巢癌移植瘤的治疗效果。方法 A2780卵巢癌模型鼠随机分为四组(10只/组):超声+微泡组(A组)、超声组(B组)、微泡组(C组)、对照组(D组)。按照实验参数每组隔天进行治疗,治疗两周,于治疗前及治疗后第14天行超声造影检查,于治疗前、治疗后第5、10、14天行二维超声,记录各组造影峰值强度(PI)及肿瘤体积(TV)大小,绘制肿瘤生长曲线等,最后行瘤体组织病理学检查。结果治疗前四组瘤体体积和PI值无明显差异(P0.05)。治疗后第5、10、14天后,A组瘤体体积和PI值均小于B、C、D组(均P0.05),B、C、D 3组间无显著性差异(均P0.05)。首次治疗14d后剥离瘤体,HE染色后光镜下观察A组瘤体组织细胞出现大部分坏死。结论低频超声联合微泡造影剂治疗可有效地破坏卵巢癌血管,抑制肿瘤的生长,或将成为一种非创伤性治疗肿瘤的新方法。     

超声辐射微泡剂抑制SMMC-7721移植瘤的实验研究及其作用机制探讨

目的研究低频超声辐射微泡剂对裸鼠移植肿瘤增长抑制情况和组织病理学变化,并探讨其与局部氧自由基代谢产物SOD浓度改变的关系。方法建立SMMC-7721系肝癌Balb/c裸鼠移植瘤模型,随机分为五组,对照组(A),微泡组(B),单纯超声组(C),超声微泡隔日组(D),超声微泡每日组(E)。连续一周观察肿瘤组织病理学损伤,肿瘤体积生长曲线和体积增长率。应用免疫组化的方法分析局部氧自由基代谢产物SOD的变化。分析增长率与SOD浓度之间的相关性。结果超声辐射D组、E组肿瘤体积明显小于对照组(P<0.05),超声辐射D组(73.20%±0.138%),E组(57.24%±0.1653%)肿瘤增长率明显低于对照的A组(121.24%±0.347%)、B组(123.13%±0.232%)和C组(108.74%±0.221%)(P<0.05),病理学检查见瘤内血栓形成和梗死,瘤组织细胞坏死。免疫组化法得出局部SOD阳性率D组(28.83%±2.483%)、E组(32.50%±3.017%)高于A组(11.50%±2.881%),(P<0.01)。并且SOD阳性率与肿瘤生长率间呈负相关(r=-0.663)。结论低频超声辐射微泡剂可以抑制肝癌移植瘤裸小鼠肿瘤的增长,并增加局部氧自由基代谢产物SOD浓度。肿瘤增长率与SOD浓度间有负相关关系。     

低频超声辐照联合微泡抑制裸鼠人前列腺癌移植瘤的实验研究

目的 观察低频超声(20 kHz)辐照联合静脉注射微泡造影剂SonoVue对裸鼠人前列腺癌Du145移植瘤的抑瘤效应,并探讨其可能的抑瘤机制.方法 通过细胞移植和瘤块移植方法建立24只裸鼠人前列腺癌Du145移植瘤模型,随机分为超声微泡组、单纯超声组、单纯微泡组和对照组,每组6只.超声微泡组:尾静脉注射0.2 mL SonoVue的同时对瘤体行20 kHz超声辐照,辐照强度2 W/cm2,辐照2 min;单纯超声组:尾静脉持续缓慢推注生理盐水0.2 mL,同时超声辐照2 min;单纯微泡组:尾静脉持续缓慢推注SonoVue 0.2 mL同时行假照;对照组不做任何处理.各组均隔天治疗1次,共3次.治疗后测量瘤体大小,绘制瘤体生长曲线,计算抑瘤率.首次治疗后14 d剥离瘤体,通过光镜、电镜观察肿瘤组织病理改变.免疫组织化学法观察CD34阳性染色血管,计算肿瘤微血管密度(MVD),比较各组间MVD的差异.结果 24只裸鼠均成功植瘤.治疗后超声微泡组瘤体体积明显小于其他各组(P＜0.05),抑瘤率为62.70%.HE染色观察超声微泡组瘤体组织大部分损伤坏死,电镜下超声微泡组肿瘤内微血管的内皮细胞损伤,线粒体肿大,基底膜断裂.超声微泡组瘤体内CD34阳性染色微血管数减少,其MVD值显著低于其他各组(P＜0.05).结论 20 kHz低频超声辐照联合微泡造影剂SonoVue可有效抑制裸鼠人前列腺癌移植瘤的生长,其抑瘤机制是超声空化效应破坏肿瘤的微血管.     

超声破坏微泡造影剂促进心肌梗死大鼠血管新生的实验研究

目的 探讨超声破坏微泡造影剂刺激大鼠心肌血管内皮生长因子(VEGF)分泌、促进新血管生成的作用.方法 建立大鼠心肌梗死模型,随机分为4组.A组行超声破坏微泡治疗,B组行单纯超声治疗,C组单纯注射微泡,D组注射生理盐水作为对照,每组均处理3次.4周后取材,免疫组化检测心肌组织中VEGF、CD34表达,ELISA及Western blot检测VEGF表达.结果 A组心肌组织中见大量VEGF和CD34表达,新生血管较多;B组有较少VEGF和CD34表达,新生血管较少;C组和D组仅有极少量VEGF和CD34表达,未见明显新生血管.ELISA检测显示,A组VEGF表达量明显增高[(8.194±1.129)Pg/g],与其他三组[B组(4.339±0.753)Pg/g,C组(2.304±0.762)Pg/g,D组(2.411士0.801)Pg/g]比较,差异均有统计学意义(P＜0.05).Western blot检测显示A组有一条约21 kD的明显的蛋白质条带表达.结论 超声破坏微泡可刺激心肌内源性 VEGF 分泌,促进血管新生.     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.