不同频率和强度超声波溶栓效果的体外实验

目的探讨体外实验条件下超声频率和强度对其溶栓效率的影响。方法取健康人全血标本56份,37℃恒温水浴孵育2h后形成体外血栓。样本被分为5个辐照组和1个对照组。辐照组分别以0．7W／cm^2,0．5MHz;0．7W／cm^2,1MHz;0．7W／cm^2,2MHz;1．4W／cm^2,2MHz和1．8W／cm^2,2MHz的脉冲式超声波照射10min;对照组无超声处理。计算血栓溶栓率,比较各相同声强不同频率组之间差异和相同频率不同声强组之间差异,并分别测溶栓率与超声波频率及强度之间的关系。结果声强0．7W／cm^2条件下,频率为0．5MHz、1MHz和2MHz的超声波有明确的溶栓效果,溶栓率与频率呈负相关（r1=1．000,P〈0．01）;频率2MHz条件下,声强为0．7W／cm^2、1．4W／cm^2和1．8W／cm^2的超声波有明确效果,溶栓率与声强呈正相关（r2=0．980,P〈0．05）。结论在一定条件下,超声波有明确的直接溶栓效果,并与频率和声强相关。诊断用超声波（频率2MHz、声强〈2W／cm^2）可能具有潜在的溶栓价值。     

超声微泡介导EGFP 质粒对视网膜母细胞瘤细胞转染效率的实验研究

目的探讨不同浓度的超声微泡造影剂，在不同声强的超声辐照下，介导DNA质粒转染视网膜母细胞瘤（RB）细胞的效率及可行性，为实现外源基因高效、定向的转移奠定基础。方法将培养的RB细胞分别予以超声条件为0．25，0．5，0．75，1．0，1．25W／cm^2，60S的连续波辐照，微泡造影剂浓度为1％，100．4，20％，30％，以筛选出对RB细胞活性无明显抑制的最适超声声强、辐照时间和微泡浓度。根据以上筛选条件，转染EGFP基因入RB细胞，24～48h后，在荧光显微镜下观察EGFP表达情况，并用RT-PCR对EGFPmRNA进行半定量检测。结果声强〈0．75W／cm^2（60s），以及微泡浓度〈20％时，对RB细胞的活性无明显抑制。当微泡浓度10％，超声声强为0．5W／cm^2或0．75W／cm^2时，介导的DNA质粒对RB细胞转染具有较高的转染效率，明显高于其他实验组。超声声强为0．5W／cm^2或0．75W／cm^2介导的转染效率，在统计学上差异无显著性意义。结论浓度适当的微泡在优化的声强条件下，能够有效地提高DNA质粒在RB细胞中的转染效率。     

微泡造影剂联合超声辐照介导的绿色荧光蛋白质粒转染小鼠肝癌的实验研究

目的探讨微泡造影剂SonoVue联合超声辐照在介导体内基因转染中的作用。方法建立小鼠肝癌皮下移植瘤模型，尾静脉注入绿色荧光蛋白质粒（pEGFP），添加或不添加SonoVue，脉冲多普勒超声辐照（1MHz，2W／cm^2）瘤组织。持续时间1、5、10min，7d后流式细胞仪、荧光显微镜评价pEGFP转染率。HE染色行肿瘤病理学检查。结果SonoVue联合超声辐照组pEGFP的转染率显著高于单纯超声辐照组（P〈0．01）；仅SonoVue与单纯pEGFP2组间转染率无显著差异（P〉0．05）；辐照时间5、10min时pEGFP表达明显高于1min（P〈0．05）。5与10min组间pEGFP表达无显著差异（P〉0．05）。HE染色肿瘤组织无坏死灶出现。结论微泡造影剂联合超声辐照可明显提高基因转染率，且对组织无损害。     

低频超声联合微泡影响前列腺癌DU145细胞血管内皮细胞生长因子表达的实验研究

目的探讨低频超声联合微泡对前列腺癌DUl45细胞血管内皮细胞生长因子（VEGF）表达的影响。方法体外培养前列腺癌DUl45细胞,细胞呈对数生长时分为4组进行实验：对照组（细胞悬液1ml）、单纯微泡组（800μl细胞悬液加入200μl微泡剂SonoVue）、单纯低频超声组（1ml细胞悬液以频率80kHz、声强0．45W／cm2超声辐照30S）、低频超声联合微泡组（800μl细胞悬液加入200μl微泡剂SonoVue后立即以频率80kHz、声强0．45W／cm2超声辐照30s）。MTT法检测细胞存活率,流式细胞术检测凋亡率,Western印迹法检测细胞VEGF蛋白的表达。采用单因素方差分析比较对照组、单纯微泡组、单纯低频超声组、低频超声联合微泡组细胞存活率、凋亡率、VEGF蛋白表达量差异,进一步组间两两比较采用SNK-q检验。结果对照组、单纯微泡组、单纯低频超声组、低频超声联合微泡组细胞存活率分别为100％、（96．50±12．49）％、（93．20±5.31）％、（81．30±9．32）％;凋亡率分别为（1．10±0．26）％、（1．78±0．63）％、（5．85±0．45）％、（9．36±0．90）％;VEGF蛋白表达量分别为0．81±0．05、0．79±0．06、0．58±0．04、0．38±0．05。单纯微泡组、单纯低频超声组细胞存活率与对照组比较差异均无统计学意义,低频超声联合微泡组细胞存活率较对照组降低,且差异有统计学意义（q=5．88,P〈0．05）。单纯微泡组细胞凋亡率、VEGF蛋白表达量与对照组比较差异均无统计学意义;单纯低频超声组、低频超声联合微泡组细胞凋亡率均高于对照组,VEGF蛋白表达量均低于对照组,且差异均有统计学意义（q=14．09、24．51、8．06、14．89,P均〈0．05）。低频超声联合微泡组细胞凋亡率高于而VEGF蛋白表达量低于单纯低频超声组,且差异亦均有统计学意义（q=10．42、6．83,P均〈0．05）。结论微泡能增强低频超声抑制前列腺癌DUl45细胞增殖及促进凋亡,其机制可能与其下调前列腺癌DUl45细胞VEGF表达有关。     

超声波增强TPA溶栓效果的体外实验

目的评价在体外实验条件下，超声波辐照对组织型纤溶酶原激活物（TPA）溶栓效率的促进作用。方法取健康人全血标本54份．37C恒温水浴孵育2h后形成体外血栓。样本被分为1μg／mlTPA组、5μg／ml μl TPA组、超声辐照组、TPA＋超声组与对照组。前4组血栓分别给予单纯给予1μg／mlTPA、单纯5μg／mgTPA；频率2MHz，声强1．8W／cm。的脉冲超声波辐照；对照组无任何处理。各组处理时间10min。计算并比较各组溶栓率。结果单用或联用TPA与超声辐照组的溶栓率均显著高于对照组（P〈50．01）且联用组显著高于任一单用组（P〈0．01）。结论超声波不仅有直接溶栓作用，还能促进TPA的药物溶栓作用。联用超声波与TPA溶栓可以在降低药量的同时提高药效，降低出血性并发症的发生，有较高的潜在临床应用价值。     

超声助溶治疗大鼠急性脑梗死

目的观察体外超声辅助尿激酶溶栓治疗急性脑梗死大鼠的效果。方法取84只Wistar大鼠，随机分为梗死组、大剂量尿激酶组（尿激酶组）、超声加小剂量尿激酶组（超声组）和假手术组。采用自身血栓栓塞法制备大鼠急性脑梗死模型，尿激酶组静脉给予尿激酶，剂量为1．5万U／只；超声组静脉给予剂量为1万U／只的尿激酶，同时经颅行超声治疗（频率为800kHz，声强为1．2W／cm^2，占空比为1：5）。采用NSS评价大鼠治疗前、后的神经功能，TTC染色测量脑梗死灶体积。结果尿激酶组和超声组治疗后24h。NSS评分均明显低于治疗前（P〈0．01）及梗死组（P〈0．01），梗死灶体积也显著小于梗死组（P〈0．01），但尿激酶组与超声组之间差异均无统计学意义（P〉0．05）。结论体外超声助溶可促进急性脑梗死大鼠神经功能的恢复，减小脑梗死灶体积，减少尿激酶的用量。     

低频超声破坏微泡造影剂开放血脑屏障的实验研究

目的探讨不同强度的低频超声经颅诱导微泡造影剂破坏对大鼠血脑屏障的影响。 方法股静脉注入微泡造影剂后，采用频率43kHz，声强分别为1．2．1．5．1．8．2．3w／cm。的连续超声波经大鼠颅骨照射3min，荧光显微镜观察伊文思兰的渗出。 结果注射微泡造影剂后，声强1．2w／cm^2时超声波即可以开放血脑屏障，随声强的增加脑组织损伤加重。 结论低频超声诱导微泡造影剂破坏可以靶向开放血脑屏障。     

不同超声强度及微泡对基因和组织作用的实验研究

目的探讨不同强度超声破坏微泡对绿色荧光蛋白质粒(green fluorcscent protein，GFP)和小鼠骨骼肌组织的作用。方法分别用0．5w／cm^2、1．0w／cm^2、2．5w／cm^2的超声作用于基因及基因和微泡的混合物2min，琼脂糖凝胶电泳观察质粒基因的电泳图谱变化。并将昆明小白鼠16只分为4组，尾静脉输入白蛋白微泡，同时分别用(0．5w／cm^2、1．0W／cm^2、2．0W／cm^2、2．5w／cm^2的超声作用于小鼠骨骼肌2min．取局部组织HE染色观察超声破坏微泡后组织显微结构的变化。结果不同能量的超声和微泡作用后GFP质粒的电泳图谱结果无变化。0．5w／cm^2超声破坏微泡后无血管充血及红细胞渗出；1．0W／cm^2超声破坏微泡后可引起约30％血管充血，极少量红细胞渗出；2．0W／cm^2超声破坏微泡后可引起约60％血管充血，红细胞渗出较明显；2．5W／cm^2的超声破坏微泡后可使部分骨骼肌变性。结论用1．0W／cm^2和2．0W／cm^2超声作用2min后引起血管充血，红细胞渗出；2．5W／cm^2超声作用2min破坏微泡后可损伤组织。1．0～2．0W／cm^2超声强度破坏微泡后对GFP质粒无明显的损害。     

微泡造影剂及超声促进绿色荧光蛋白质粒在人肝癌细胞HepG2内表达的实验研究

目的研究微泡造影剂与超声辐照是否能提高绿色荧光蛋白质粒在人肝癌细胞HepG2中的转染率。方法将培养的HepG2细胞分为四组：第一组为对照组；第二组以脂质体转染；第三组加入微泡造影剂SonoVue并予以超声辐照；第四组加入脂质体和微泡造影剂SonoVue并予以超声辐照．将合有绿色荧光蛋白报告基因的真核表达质粒pEGFP-N1转染人肝癌细胞HepG2，24小时后以荧光显微镜观察人肝癌细胞HepG2中的绿色荧光蛋白表达情况，并用流式细胞仪测算转染率。结果脂质体转染组与微泡造影剂＋超声辐照组有显著性差异（P〈0．05）。脂质体＋微泡造影剂＋超声辐照组与微泡造影剂＋超声辐照组有显著性差异（P〈0．01）结论微泡造影剂和超声辐照协同脂质体能提高目标基因在肝癌细胞内的转染率。     

超声辐照微泡声学造影剂增强脂质体介导肝细胞基因转染的体外实验研究

目的研究超声破坏微泡声学造影剂提高脂质体介导肝细胞生长因子质粒（plRES—EGFP—HGF）在肝细胞中转染率的可行性。 方法将培养的肝细胞分为4组：（1）单纯对照组，（2）脂质体转染组，（3）超声辐照脂质体转染组，（4）超声辐照微泡＋脂质体转染组。第（4）组按照每孔加入造影剂剂量又分为1）10μl组，2）20μl组，3）30μl组，4）40μl组4亚组。超声辐照微泡＋脂质体转染组在脂质体介导肝细胞生长因子转染肝细胞1h后，在24孔板中每孔加入微泡声学造影剂10，20，30或40μl，超声辐照60s。24h后用荧光显微镜观察绿色荧光蛋白表达情况、MTT法检测肝细胞增殖率和流式细胞仪检测基因转染率。 结果超声频率1MHz，功率0．5W／cm。辐照60S，每孔加入造影剂30μl时肝细胞基因转染效率最高，与脂质体转染组比较有显著性。 结论在一定条件下，超声辐照微泡声学造影剂可明显提高脂质体介导肝细胞基因转染效率，为基因治疗提供了新的思路。     

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.