再次急性心肌梗死的不同时间窗rt—PA溶栓疗效对比研究

目的：探讨再次急性心肌梗死患者不同时间窗rt—PA溶栓的临床疗效。方法：51例入选患者根据再发心肌梗死到接受溶栓治疗的时间分为两组，A组28例为1—3小时；B组23例为3—6小时。两组均给予静脉内100mg rt—PA溶栓辅予相同的常规治疗。结果：A组再通率78．6％，B组再通率65．2％，A组临床症状改善和冠脉再通率与B组有显著差异（P〈0．05），2周内LEVF亦有显著差异（P〈0．05），并发症明显减少。结论：静脉内rt—PA溶栓治疗对再次急性心肌梗死患者仍有较好疗效，溶栓越早疗效越好。     

尿激酶溶栓治疗急性心肌梗死临床研究

目的：观察老年人用尿激酶（UK）治疗急性心肌梗死（AMI）的溶栓效果和不良反应。方法：对42例老年人AMI患者给予UK溶栓治疗,观察溶栓再通率、急性期病死率（35天）、不良反应发生率。结果：溶栓再通率为61．90％,急性期病死率为9．52％,不良反应发生率上消化道出血2．38％。58例老年人未溶栓组溶栓再通率22．41％,急性期病死率34．48％,不良反应率上消化道出血2．38％。结论：老年人尿激酶治疗急性心肌梗死,再通率较未溶栓组高（P＜0．001）,病死率明显降低（P＜0．001）,具有非常性显著意义。不良反应无明显改变（P＞0．05）。     

重组人尿激酶原治疗急性心肌梗死的有效性及安全性评价

目的：观察国产重组人尿激酶原（Pro—uk）溶栓治疗急性心肌梗死（AMI）的有效性及安全性。方法：将68例发病6h内的AMI患者随机分为Pro—uk组（n=43）和尿激酶（UK）组（n=25）。其中Pro—uk 50mg组22例、Pro-uk 60mg组21例。观察主要疗效及安全性指标。结果：在溶栓后90min进行冠状动脉造影，Pro—uk组总的梗死相关动脉再通率（TIMI2级＋TIMI3级）为76．7％，明显高于UK组52．2％（P〈0．05），其中Pro—uk50mg为77．3％（17／22），60mg为76．2％（16／21）。Pro—uk组轻度出血并发症显著低于UK组（P〈0．05）；两组均无颅内出血等严重并发症发生。早期心脏事件发生率以及不良反应发生率两组差异均无统计学意义。结论：AMI时应用Pro—uk50-60mg进行静脉溶栓成功率高，使用安全，副作用低。     

慢性阻塞性肺病并发急性心肌梗死的溶栓疗效探讨

目的：通过对慢性阻塞性肺病（COPD）并发急性心肌梗死（AMI）后溶栓疗效观察，评价COPD并发AMI患者对溶栓的耐受性及预后影响。方法：收集同期住院接受溶栓治疗的179例AMI的临床资料，将其中合并COPD的56例与非COPD的123例行对比分析，观察两组溶栓后冠脉再通率，住院期间并发症的发生率及住院病死率。结果：溶栓后冠脉再通率在＜4h时间段比较两组结果相似，而冠脉总再通率在COPD组（51．79％）低于非COPD组（63．42％），但无显著差异（P＞0．05）；住院期间并发肺部感染、胃出血的发生率在COPD组显著高于非COPD组（P＜0．01），而并发心律失常、心绞痛的发生率在两组间无显著差异（P＞0．05）；COPD组（17．86％）与非COPD组（9．80％）的住院期间病死率比较无显著差异（P＞0．05）。结论：COPD并AMI患者对溶栓的耐受性良好，静脉溶栓的效果与非COPD组相近。缩短开始溶栓的时间是提高冠脉再通率，改善预后的关键。     

重组组织型纤溶酶原激活剂与尿激酶溶栓治疗急性心肌梗死的疗效比较

目的：观察小剂量（50mg)重组织型纤维酶原激活剂（rt-PA)与尿激酶（UK）溶栓治疗急性心肌梗死（AMI）的疗效及安全性,方法：将116例AMI患随机分为rt-PA组和UK组,分别应用rt-PA和UK溶栓治疗,结果：冠状动脉（冠脉）总再通率分别rt-PA组80．65％和UK组为51．85％,患在发病后6h内治疗,冠脉再通率分别为rt-PA组91．18％和UK组67．86％,前明显高于后,两组比较均有显差异（P＜0．01）,5wk住院病死率分别为rt-PA组6．5％和UK组11．1％,结论：小剂量（50mg)rt-PA用于AMI溶栓治疗的临床疗效明显优于UK,血管再通率高,尤其在发病后6h内进行治疗效果更佳.rt-PA溶栓并发症少,可降低闰 率,是一种安全有效的溶栓剂.     

缺血预适应对急性心肌梗死溶栓患者冠脉再通及近期预后的影响

[目的]探讨缺血预适应对急性心肌梗死（AMI）溶栓治疗后冠脉再通及近期预后的影响。[方法]对139例AMI并予尿激酶溶栓患者的临床资料进行分析,根据梗死前3d内有无心绞痛分为缺血顸适应（IP）组和非缺血预适应（NIP）组,比较两组患者冠脉再通率、梗死面积、左室功能及心脏主要不良事件发生率的差异。[结果]iP组冠脉再通率、梗死后左室射血分数（LVEF）值恢复优于NIP组（P〈O．05）;IP组溶栓后梗死面积较溶栓前明显缩小（P〈0．05）;IP组溶栓后梗死面积、心脏主要不良事件发生率低于NIP组（分别为P〈0．05、P〈0．01）;回归分析显示：IP与冠脉再通呈正相关（b=o．962,P〈0．05）,与心脏主要不良事件呈负相关（b=0．656,P〈o．05）。[结论]IP对AMI患者缺血心肌具有保护作用,可提高溶栓后冠脉再通率,减少梗死面积,改善心功能,降低心脏主要不良事件的发生率,是影响冠脉再通及近期预后的独立因素。     

急性心肌梗死溶栓治疗后临床指标与冠脉造影判断冠脉再通的效能对比研究

目的 研究急性心肌梗死(AMI)溶栓治疗后，临床指标判定再通的敏感度。方法 72例AMI患者，采用静脉药物溶栓治疗后90min行冠状动脉造影，判定冠脉是否再通，同时与临床判断再通的指标进行比较。结果 临床判定冠脉再通的指标与冠脉造影判定冠脉再通的结果无显著性差别，两者判定再通效能相关性好(r=0．8522)，临床判定血管再通的指标敏感度97．73％，特异度85．7％，准确度93．1％。结论 临床再通指标与冠脉造影判断冠脉再通相关性好，在没有冠脉造影的条件下。临床指标仍然是判定冠脉再通的有效指征。     

依诺肝素辅助瑞替普酶静脉溶栓治疗急性心肌梗死的临床研究

目的：探讨瑞替普酶静脉溶栓辅助应用依诺肝素替代普通肝素抗凝治疗急性心肌梗死（AMI）的安全性与有效性。方法：86例AMI患者在瑞替普酶静脉溶栓时随机分为依诺肝素组（45例）和静脉普通肝素组（41例）,2周后行冠状动脉造影及冠脉介入治疗（PCI）。观察临床再通率、血管开通率、急性期并发症、出血及不良反应发生率。结果：依诺肝素组与普通肝素组临床再通率、血管开通率比较差异无统计学意义（P〉0．05）。两组急性期并发症发生率比较差异无统计学意义（P〉0．05）。依诺肝素组出血并发症低于静脉普通肝素组,两组比较差异有统计学意义（P〈0．05）。结论：瑞替普酶并依诺肝素用于AMI再灌注治疗是安全有效的。     

老年急性心肌梗死不同时间窗溶栓效果的观察

目的比较老年急性心肌梗死（acute mrocardialinfarction,AMI）发病后不同时间窗静脉溶栓治疗效果。方法120例老年AMI患者按发病到溶栓治疗开始时间分为〈5h（5h）组和6—12h组（延迟组）,在AMI常规治疗的基础上予尿激酶（UK）150万u溶栓治疗。结果5h组血管再通率、4周病死率、严重心衰发生率、半年后左室射血分数（LVEF）分别为71．67％、3．33％、6．67％、（63±8．1）％;延迟组血管再通率、4周病死率、严重心衰发生率、半年后LVEF分别为15．0％、13．33％、12．0％、（51．5±9．5）％两组比较有统计学差异（P〈0．01及P〈0．05）,而出血并发症的发生率,两组无统计学差异（P〉O．05）。结论5h组血管再通率,LVEF较高,4周病死率低。     

溶栓后梗死冠状动脉早期再通的临床预测指标

受试对象为1030例急性心肌梗死患者。皆于胸痛6小时内接受下列溶栓疗法：①链激酶加皮下注射肝素；②链激酶加静注肝素；③大剂量组织型纤维蛋白溶酶原激活物（t－PA）加静注肝素；④链激酶加t－PA加静注肝素。于溶栓后90分钟均接受冠状动脉（冠脉）造影，若结果显示原梗死冠脉再通血流达到正常视为再通。嗣后分析梗死冠脉早期再通各相关临床指标。结果显示，预测溶栓后90分钟冠脉成功再通的独立相关性临床指标包括：使用大剂量t－PA（再通率比键激酶高2．5倍P＜0．0001），梗死部位（右冠脉及左回旋支再通率比左前降支高1.6倍，P=0．00…     

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.