载自杀基因的靶向微泡联合超声抑制视网膜母细胞瘤的实验研究

目的 探讨载自杀基因的靶向微泡联合超声对视网膜母细胞瘤（RB）的抑制作用。方法 制备携带单纯疱疹病毒Ⅰ型胸苷激酶（HSV1-tk）质粒和VEGFR2抗体的靶向微泡,分为空白对照组、细胞+质粒组、细胞+质粒+SonoVue组、细胞+靶向微泡组、细胞+质粒+超声辐照组、细胞+质粒+SonoVue+超声辐照组和细胞+靶向微泡+超声辐照组进行实验。荧光显微镜观察基因转染情况,流式细胞仪检测转染率,加入丙氧鸟苷（GCV）后,检测细胞的抑制率。结果 细胞+靶向微泡+超声辐照组的转染率为（24.78±1.04）%,较细胞+质粒+SonoVue+超声辐照组（14.31±0.69）%高。随着GCV浓度的增加,培养时间的延长,各组的抑制率逐渐升高。当GCV浓度在100 mg/l,培养96h后,细胞+靶向微泡+超声辐照组对RB细胞的抑制率达（92.91±1.71）%。结论 在加入GCV后,携带HSV1–tk的靶向微泡联合超声能有效的抑制RB细胞。     

超声联合微泡增强脂质体介导基因转染RPE细胞的实验研究

目的 比较声诺维联合超声与脂质体法介导基因转染RPE细胞的转染率和安全性,探讨超声联合微泡增强脂质体转染率的可行性.方法 RPE细胞培养在24孔板,质粒用量2 μg/孔,分为对照组、超声辐照组、超声联合微泡组(包括2 W/cm2和3 W/cm2两个亚组)、脂质体组、脂质体+超声+微泡组5组,每组10孔细胞.荧光显微镜观察基因转染情况,流式细胞仪检测基因转染率,Annexin Ⅴ-FITC和PI双染流式细胞法检测凋亡率.结果 单纯超声辐照组基因转染率为(1.06±0.13)%,超声联合微泡组分别为(15.81±1.70)%和(20.86±2.63)%,脂质体组为(30.06±3.49)%,明显高于超声联合微泡组(P<0.05).脂质体+超声+微泡组为(44.51±1.28)%,明显高于脂质体组(P<0.05).结论 脂质体介导EGFP转染RPE细胞的效率高于超声联合微泡的转染率.超声联合微泡能明显提高脂质体的转染率.     

声诺维联合超声介导视网膜色素上皮细胞基因转染的辐照条件优化研究

目的探讨微泡造影剂声诺维联合超声介导绿色荧光蛋白质粒转染人视网膜色素上皮(RPE)细胞的最佳辐照条件。方法人RPE细胞培养在24孔板,质粒用量为2μg/孔,分为不处理组、质粒 超声辐照组、造影剂浓度组、超声声强组、辐照时间组、声波形式组6组,每组5个细胞孔数,超声探头紧贴培养板底部辐照,72h后流式细胞仪测基因转染率,四甲基偶氮唑蓝法(MTT)测细胞活性。结果处理组转染率均大于不处理组(P<0.05)。加入浓度为20%的造影剂,以1W/cm2,50Hz、100Hz的脉冲波和连续波分别辐照1min,细胞生存率逐渐下降。20%的造影剂,50Hz的脉冲波,声强为3W/cm2,辐照1min组转染率最高(20.88±3.74)%,而细胞生存率为82.57%。20%的造影剂,50Hz的脉冲波,声强为2W/cm2,辐照1min组转染率为(15.73±2.52)%,细胞生存率为91.32%。结论20%的造影剂,2W/cm2,50Hz脉冲波辐照1min是RPE细胞基因传染的最佳辐照条件。     

JAR细胞靶向微泡造影剂的体外研究

目的探讨体外靶向SonoVue微泡与人绒毛膜癌细胞（JAR细胞）的结合特性、结合率及靶向微泡的稳定性,为在体研究肿瘤细胞抗原的超声定位显像奠定基础。 方法用SonoVue微泡与兔抗人HCG抗体作用制成靶向造影剂、然后分别与JAR细胞及子宫内膜间质细胞（ESC）作用,比较各自的结合率及冲洗前后的结合率。 结果SonoVue微泡与兔抗人HCG抗体的结合率为67.6%;JAR细胞与靶向SonoVue微泡的花环形成率为（84.3±5.5）%,明显高于ESC的花环形成率（11.4±1.5）%（P〈0.05）;靶向SonoVue微泡与贴壁生长的JAR细胞结合率为（85.8±3.3）%,冲洗后结合率为（82.4±3.7）%（P〉0.05）;流式细胞仪检测JAR细胞与靶向SonoVue微泡的结合率为81.0%。 结论在体外靶向SonoVue微泡与JAR细胞特异性结合力具有一定的强度,可望实现靶向显影。     

声动力学治疗对MDA-MB-231细胞增殖及侵袭能力的影响

目的 探讨超声辐照血卟啉单甲醚和声诺维对乳腺癌细胞株MDA-MB-231增殖及侵袭能力的影响。方法 将对数生长期的MDA-MB-231细胞制成细胞悬液,加入HMME和SonoVue后用超声进行辐照。分3组：对照组,不接受治疗;辐照组1：输出声强0.3 W/cm²,辐照时间60 s;辐照组2：输出声强0.6 W/cm²,辐照时间30 s。采用MTS法绘制细胞生长曲线,平板克隆方法观察细胞形成克隆的能力,并用Transwell小室法检测细胞侵袭能力。结果 对照组的生长曲线陡直,而辐照组的曲线平缓。接种2周后对照组出现肉眼可见的细胞克隆,而辐照组未出现。结晶紫染色后观察,辐照组仅可见由少许细胞聚集成的细胞团。接种后24 h、48 h观察,对照组、辐照组1、辐照组2穿越小室的细胞数分别为42.00±13.52、3.52±1.26、2.75±0.96（P<0.05）及104.25±12.61、36.25±3.40、28.75±4.99（P<0.05）。对照组穿越小室的细胞数显著高于辐照组（P<0.05）。结论 超声辐照联合HMME及SonoVue能有效抑制MB-231细胞增殖,降低细胞形成克隆的能力,并显著降低细胞的侵袭能力。     

超声靶向辐照微泡造影剂介导重组腺相关病毒转染肾癌细胞的研究

目的 以聚乙二醇-聚乳酸羟基乙醇酸-聚赖氨酸(mPEG-PLGA-PLL)阳离子复合物为骨架,构建携带Cy3-siRNA的载基因纳米粒子。探讨超声和(或)微泡造影剂SonoVue促进载Cy3-siRNA 纳米粒子转染鼠源性视网膜色素上皮(RPE)细胞的可行性。方法 采用复乳法制备载Cy3-siRNA纳米粒,检测其粒径、包封率及体外释放情况。在不同的纳米粒子浓度(0.05~0.5mg/ml)和孵育时间下(10min,1~24h),检测载Cy3-siRNA 基因纳米粒子在RPE细胞中的内化过程。载Cy3-siRNA 基因纳米粒子与培养的RPE细胞一起孵育,不同超声辐照条件下,利用倒置荧光显微镜、流式细胞仪观察测定细胞10min瞬态转染和24h稳态转染效果,MTT法检测48h后细胞增殖情况。筛选超声和(或)微泡造影剂介导载Cy3-siRNA纳米粒子转染RPE细胞的最佳转染条件。结果 动态光散射测量纳米粒子的平均直径是(150±20)nm;Zeta电位通过多普勒电泳光散射测量纳米粒子电位为(13±3)mV,高效液相色谱测得包封率为93.3%,28天后纳米粒子的释放率为78.6%。纳米粒子的内化程度随着浓度的增加而增加,在0.45mg/ml时达到了一个平台期,Cy3-siRNA 转染率为(87.0±5.6)%。孵育时间延长,转染率增高,接触时间为12h时,转染率最高。当纳米粒子浓度达到0.5mg/ml时,仍未发现细胞毒性作用。超声声强为0.5W/cm²,辐照时间60s,工作周期50%时,可以提高纳米粒子的转染率达56.3%(P=0.008)。单纯微泡组,微泡浓度为20%时,也可提高纳米粒子在RPE细胞中的转染率(P=0.012)。但是,超声联合微泡组未进一步提高基因的转染(P=0.68)。结论 超声声强为0.5W/cm²,辐照时间60s,工作周期50%时,可以提高纳米粒子的转染率。微泡浓度为20%时,也可提高纳米粒子在RPE细胞中的转染率。超声或微泡造影剂SonoVue可以促进载Cy3-siRNA纳米粒子转染RPE细胞。     

超声辐照和SonoVue微泡在介导hAng-1基因体外转染时的作用和量效关系探讨

目的 探讨超声辐照和SonoVue微泡分别使用和联用在介导hAng-1基因体外转染过程中的作用以及辐照强度和微泡浓度对转染效率和细胞活性的影响.方法 实验分四组A组:单纯超声辐照+质粒组;B组:微泡+质粒组;C组:超声辐照+微泡+质粒组和空白对照组D组. C组内转染参数分别设置为超声照射强度0.5、1.0 、1.5和2.0 W/cm~2,微泡浓度5%、10%、20%、30%和40%.将连接有eGFP-C_3-hAng-1质粒的SonoVue微泡对293T细胞进行转染,48 h后检测各组基因转染效率和细胞存活率. 结果转染48 h后C组转染效率最高,荧光阳性细胞数最多,强度最大;A组转染效率很低,见少量荧光表达;B、D组无明显基因转染发生.随着超声照射强度和微泡浓度的增加,基因转染效率会逐步升高,具有统计学意义.微泡浓度大于20%、超声照射强度超过1.5 W/cm~2后基因转染效率不再升高甚至降低,细胞死亡率显著增高(P<0.01).结论 SonoVue微泡介导外源基因转染必须联合超声辐照才能获得较好的转染效率.对于hAng-1基因和SonoVue微泡,选择声强1.5 W/cm~2,微泡浓度20%是相对最佳转染条件.     

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。     

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。     

声诺维联合超声辐照增强绿色荧光蛋白质粒转染血管内皮细胞的实验研究

目的探讨造影剂声诺维(SonoVue)联合超声辐照人脐血管内皮细胞(HUVEC)时增强型绿色荧光蛋白报告基因质粒(pEGFP)的瞬时转染效率。方法使用连续多普勒超声辐照方式介导pEGFP转染HUVEC,照射条件为频率1.9MHz,TIS0.8,SATA为80.0mW/cm2,时间持续5min,添加或不添加2%SonoVue,pEGFP浓度为50μg/ml。48h后用流式细胞仪检测绿色荧光蛋白(GFP)瞬时转染表达率,并用台盼蓝染色检测细胞活性(生存率)。结果单纯超声辐照组GFP转染率仅为1.5%±0.2%,SonoVue联合超声辐照组为16.1%±1.9%(P<0.001);两组细胞生存率分别为94.1%±2.3%和91.1%±4.1%(P>0.05)。结论SonoVue联合超声辐照条件可增强pEGFP转染HUVEC的效率,而对细胞活性无明显影响,此方法可用于目的基因转染。     

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.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.