靶向超声介导VEGF165cDNA基因治疗大鼠心肌缺血的实验研究

目的探讨靶向超声介导VEGF165 cDNA基因治疗大鼠心肌缺血的可行性.方法将60只心肌缺血的雄性SD大鼠分为3组超声介导基因组(采用超声破坏微泡造影剂的方法将VEGF165 cDNA基因转染大鼠)、单纯基因组(尾静脉输入同等量携带VEGF165cDNA基因的造影剂)、对照组.每组又分为24 h后处死组和14d后处死组,每小组为10只.处死后分别行坏死区中性粒细胞记数,梗死区质量比测定,免疫组织化学检测缺血心肌中的VEGF蛋白表达,缺血心肌区域毛细血管记数.结果24 h处死组超声介导基因组坏死区中性粒细胞平均为(59.30±7.70)个/高倍视野,单纯基因组为(62.53±7.50)个/高倍视野.14 d后处死组超声介导基因组梗死区质量比明显小于单纯基因组,单纯基因组又明显小于对照组.超声介导基因组有大量VEGF蛋白阳性反应的棕褐色颗粒,而单纯基因组VEGF蛋白阳性反应的棕褐色颗粒少于超声介导基因组.结论超声介导微泡造影剂携带VEGF165cDNA基因能提高基因转染率,促进缺血区毛细血管再生,减少心肌梗死面积,对缺血区炎性细胞的浸润也有一些影响,且基因的转染＞24 h.     

靶向超声介导抗细胞间黏附因子-1单克隆抗体对大鼠心肌缺血再灌注损伤的实验性研究

目的探讨靶向超声能否提高抗细胞间黏附因子-1单克隆抗体对大鼠心肌缺血再灌注损伤的保护作用。方法将60只心肌缺血的雄性SD大鼠分为3组,第1组为超声介导抗细胞间黏附因子-1单克隆抗体定向于受损心肌组,第2组为单纯抗细胞间黏附因子-1单克隆抗体组;第3组为对照组。每组又分为24h后处死组和14d后处死质量分数组,每小组为10只。处死后分别行坏死区中性粒细胞记数,梗死区质量分数测定,免疫组织化学检测缺血心肌中的VEGF蛋白表达,缺血心肌区域毛细血管记数,观察用药前后心电图ST段改变。结果24h处死组超声介导组坏死区中性粒细胞平均记数少于单纯用药组,超声介导组梗死区面积明显小于单纯用药组。14d后处死组超声介导组梗死区重量比明显小于单纯用药组,且有大量VEGF蛋白阳性反应的棕褐色颗粒。结论超声介导微泡造影剂携带抗细胞间黏附因子-1单克隆抗体能提高局部药物浓度,减少中性粒细胞在缺血心肌的浸润,减少组织再损伤,促进缺血区毛细血管再生,减少心肌梗死面积。     

靶向超声介导VEGF_(165) cDNA基因及抗ICAM-1单克隆抗体治疗大鼠心肌缺血的对比性研究

目的 探讨靶向超声介导VEGF_(165) cDNA、抗ICAM-1单克隆抗体及两者协同作用于受损心肌的有效性及可行性.方法 将80只心肌缺血的雄性SD大鼠随机分为四组:第一组采用超声击破微泡造影剂的方法将VEGF_(165) cDNA基因及抗ICAM-1单克隆抗体混合物定向于受损心肌;第二组采用超声击破微泡造影剂的方法将VEGF_(165) cDNA基因定向于受损心肌;第三组采用超声击破微泡造影剂的方法将抗ICAM-1单克隆抗体定向于受损心肌;第四组为对照组只注射生理盐水1 ml,不采用超声波照射.每组分别于24 h和14 d后处死10只.处死后分别行坏死区中性粒细胞记数,梗死区测定,免疫组织化学检测缺血心肌中的VEGF蛋白表达,缺血坏死心肌区域毛细血管记数.结果 第一组大鼠心肌缺血治疗效果较第二、第三组效果显著,第一组中性粒细胞浸润以及心肌梗死区域均明显低于其他各组,VEGF蛋白表达以及毛细血管记数明显高于其他三组.结论 采用超声触发破坏含靶基因及抗体的微泡造影剂的方式,可明显对抗心肌再损伤,促进缺血心肌的新生血管再生,改善心肌缺血,且两者协同作用比单独作用效果更佳.     

超声造影剂介导血管内皮生长因子基因治疗心肌缺血的实验研究

目的探讨超声破坏造影剂微泡介导血管内皮生长因子(VEGF)基因转染兔缺血心肌的有效性。方法新西兰白兔48只，结扎兔冠状动脉左旋支，建立急性心肌梗死模型。术后3d，经胸超声检查左室壁运动情况，明确心肌缺血区域，然后将VEGF真核表达质粒与新型超声造影剂JD-95混合后，经耳缘静脉输入兔体内，同时进行超声实时造影成像，照射心脏缺血区。其他对照组包括超声和造影剂组、单独基因组、基因和超声组、基因和造影剂组以及空白对照组。术后17d处死动物，取动物缺血心肌、肝、肾及下肢骨骼肌组织，用免疫组化方法检测VEGF蛋白表达。结果在超声破坏造影剂微泡介导基因转染的实验组中5只兔的缺血心肌中VEGF蛋白的表达，2只兔肾有VEGF表达。而其他对照组中无VEGF蛋白表达。结论超声破坏造影剂微气泡的方法是将体外生物活性物质传递至心肌中的一种有效途径。     

超声微泡造影剂介导VEGF基因治疗大鼠心肌缺血的实验性研究

目的：探讨超声微泡造影剂介导血管内皮生长因子（VEGF）基因转染大鼠缺血心肌的有效性。方法：将15只急性心肌梗塞3天后的雄性Wistar大鼠分为3组，每组5只，第一组采用超声破坏微泡造影剂的方式将pcD2VEGF121基因转染大鼠心肌约6分钟；第二组尾静脉输入同等剂量携pcD2VEGF121基因的造影剂；第三组为对照。2周后，分别行免疫组织化学检测缺血心肌中的VEGF蛋白及毛细血管内皮细胞，结果：采用超声微泡造影剂介导的VEGF基因转染，能明显增强VEGF基因在大鼠心肌组织内的表达，并可促进缺血心肌组织新生血管，结论：超声微泡造影剂介导的VEGF基因治疗是一种无创、新型、高效的基因转移方法。     

超声微泡造影剂对心肌组织的生物学效应及介导VEGF基因转染大鼠心肌的实验研究

目的探讨超声微泡造影剂对心肌组织的生物学效应及其介导VEGF基因转染大鼠心肌的有效性. 方法 18只健康雄性Wistar大鼠,取3只采用超声波在鼠胸壁破坏微泡造影剂,观察对心肌组织显微结构的影响.将另15只急性心肌梗死3天后的雄性Wistar大鼠分为3组,每组5只.第一组采用超声破坏微泡造影剂的方式,将pcD2VEGF121基因转染大鼠心肌至造影剂不再显影(约6min);第二组尾静脉输入同等剂量携pcD2VEGF121基因的造影剂;第三组为对照.2周后,取缺血心肌组织行VEGF免疫组织化学染色,观察心肌组织血管内皮生长因子(VEGF)蛋白表达情况.结果超声波破坏微泡造影剂能使心肌组织充血,产生大量空泡,并有部分心肌细胞坏死.采用超声微泡造影剂介导的VEGF基因转染,能明显增强大鼠心肌组织VEGF蛋白的表达.结论超声微泡造影剂能明显增强对组织的空化效应,其介导的VEGF基因治疗是一种无创、新型、高效的基因转移方法.     

超声微泡造影剂对心肌组织的生物学效应及介导VEGF基因转染大鼠心肌的实验研究

目的 探讨超声微泡造影剂对心肌组织的生物学效应及其介导VEGF基因转染大鼠心肌的有效性。方法 18只健康雄性Wistar大鼠，取3只采用超声波在鼠胸壁破坏微泡造影剂，观察对心肌组织显微结构的影响。将另15只急性心肌梗死3天后的雄性Wistar大鼠分为3组，每组5只。第一组采用超声破坏微泡造影剂的方式，将pcDzVEGFm基因转染大鼠心肌至造影剂不再显影(约6min)；第二组尾静脉输入同等剂量携pcD。VEGF。基因的造影剂；第三组为对照。2周后，取缺血心肌组织行VEGF免疫组织化学染色，观察心肌组织血管内皮生长因子(VEGF)蛋白表达情况。结果超声波破坏微泡造影剂能使心肌组织充血，产生大量空泡，并有部分心肌细胞坏死。采用超声微泡造影剂介导的VEGF基因转染，能明显增强大鼠心肌组织VEGF蛋白的表达。结论 超声微泡造影剂能明显增强对组织的空化效应，其介导的VEGF基因治疗是一种无创、新型、高效的基因转移方法。     

超声介导微泡靶向传输基因促血管新生的实验研究

目的探讨超声介导微泡靶向传输血管内皮生长因子VEGF165促心肌血管新生即心肌“分子搭桥”的新途径。方法利用分子生物学方法构建人血管内皮生长因子真核表达质粒pcDNA3.1-/VEGF165;制备载VEGF165基因脂质体微泡,分析其理化性质和功能,在超声场利用超声辐射向大鼠梗死心肌靶向传输VEGF165;2周后取材,逆转录聚合酶链式反应(RT PCR)评价大鼠心肌中人源VEGF165mRNA表达,蛋白印迹杂交(WesternBlot)观察大鼠心肌VEGF165的蛋白表达,CD34免疫组化微血管密度(MVD)计数半定量法评价超声介导微泡靶向传输VEGF165促梗死心肌血管新生效果。结果①成功构建、克隆血管内皮生长基因VEGF165重组真核表达质粒pcDNA3.1-/VEGF165,测序分析、酶切鉴定准确无误;②研制的脂质体微泡超微结构显示可粘附或包载DNA,粒度分析显示平均粒径<5μm;③在超声介导下该脂质体载基因微泡可靶向传输VEGF165至大鼠梗死心肌,超声介导靶向传输组VEGF165的mRNA、蛋白表达及促血管新生作用(MVD表示)仅次于VEGF165基因心肌注射组。结论超声介导微泡可向大鼠心肌靶向传输VEGF165基因并产生促血管新生效应。     

血管内皮生长因子对心肌细胞移植治疗心肌梗死有改善血供作用

目的：探讨腺病毒介导血管内皮生长因子165基因（AdVEGF165）转染的乳鼠心肌细胞移植对慢性心梗（MI）大鼠一心功能的影响。方法：体外培养新生大鼠心室肌细胞、标记BrdU、转染AdVEGF165基因；收集培养液上清，ELISA法检测转染细胞VEGF的表达。结扎同种大鼠前降支建立心梗模型，4周后将心梗大鼠随机分为3组。分别注射移植转染心肌细胞（组Ⅰ）、单纯心肌细胞（组Ⅱ）、和DMEM培养基（组Ⅲ）。超声心动图检测移植前厦移植4周后的心功能。处死大鼠，留取心脏标本作HE病理染色厦免疫组化检测，并计数血管密度。结果：AdVEGF165基因转染的心肌细胞表达VEGF升高，较对照组有显著差异（P〈0．01）；超声检测心功提示转染细胞组（组Ⅰ）心功能较其他2组显著改善（P〈0．01）；免疫组化检测显示，移植细胞在移植区存活；HE染色血管计数显示转染组（组Ⅰ）有更多的新生血管形成（P〈0．01）。结论：AdVEGF165基因转染心肌细胞后表达分泌VEGF增加，可促进梗死区新生血管形成，改善心肌血供，有利于移植细胞的存活，能更好的改善心功能。     

靶向超声介导VEGF基因转染防止血管再狭窄的实验研究

目的 探讨超声造影剂SonoVue携带血管内皮生长因子(VEGF)基因靶向释放、转染损伤血管防止其再狭窄的可行性.方法 构建真核表达质粒pCDNA3.1(-)/hVEGF165.建立兔股动脉的球囊损伤模型并随机分为两组:损伤后不干预的对照组;损伤后血管腔内注射携带VEGF基因质粒的造影剂并行超声辐照的实验组.4周后取损伤处血管,HE染色计算血管内膜/中膜面积比值,免疫组化及Western Blot了解血管壁平滑肌细胞的增殖情况和VEGF的表达.结果 实验组的血管内膜/中膜面积比值显著低于对照组(P<0.05),免疫组化显示实验组血管壁平滑肌细胞增殖核抗原(PCNA)表达明显减低,同时可见大量VEGF阳性反应的棕褐色颗粒,Western Blot提示实验组VEGF的表达量明显高于对照组(P<0.05).结论 超声介导的靶向释放可以实现VEGF基因的有效转染,减轻损伤内膜的病理增生,有效阻止血管再狭窄发生,提示靶向超声可以为防止血管再狭窄的基因治疗提供新途径.     

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.