超声多普勒检测内皮功能的临床应用

目的应用超声多普勒观察祛瘀消斑胶囊对动脉粥样硬化患者(AS)肱动脉内皮依赖性舒张功能的改善作用.方法应用高分辨率血管外超声技术,对31例AS患者治疗前后和30例正常对照者的肱动脉内皮依赖性舒张和非内皮依赖性舒张进行检测.结果治疗前AS患者肱动脉血流介导的舒张校正常对照组明显减弱,(2.51±2.36)%比(8.17±4.82)%,P＜0.001,而两组对硝酸甘油的反应无显著性差异.动脉粥样硬化患者服用祛瘀消斑胶囊6个月后,血浆胆固醇水平显著降低,同时肱动脉内皮依赖性舒张较治疗前明显改善,(7.53±3.24)%比(2.51±2.36)%,P＜0.001,而治疗前后肱动脉对硝酸甘油的反应无显著性差异.结论祛瘀消斑胶囊能明显改善动脉弱样硬化的内皮依赖性血管舒张功能.     

心元胶囊对冠心病患者血管内皮功能的影响

目的 观察心元胶囊对冠心病患者血脂和血管内皮功能影响.方法 对照组给予冠心病标准化治疗3个月;治疗组为标准化治疗 心元胶囊,两组患者在入选时及入选3个月后检测血脂指标,用超声检测肱动脉流量介导性扩张的血管内皮依赖性舒张功能.结果 治疗3个月后,对照组的TC、LDL-C水平较治疗前明显降低;治疗组的TC、LDL-C水平较治疗前明显降低.两组间治疗后血脂各项水平改善程度无明显差别.两组治疗后血流介导的血管舒张功能均较治疗前明显改善,治疗组较对照组的改善程度明显增加.结论 心元胶囊可以改善冠心病患者血管内皮依赖性舒张功能.     

动脉粥样硬化患者血管内皮功能的超声评价

目的 :用高分辨力超声检测动脉粥样硬化 (AS)患者的血管内皮功能。方法 :用高分辨力超声检测38例 AS患者和 30例正常对照组肱动脉反应性充血和含服硝酸甘油后变化 ,并测定血浆 NO、ET- 1及血脂水平。结果 :AS组肱动脉血流介导性舒张较对照组明显减弱 [(2 .6 3± 1.5 6 ) %比 (8.2 5± 4 .16 ) % ,P<0 .0 0 1],而两组对硝酸甘油的反应无显著性差异 [(16 .93± 6 .74 ) %比 (2 0 .35± 3.2 1) % ,P>0 .0 5 ]。 AS组血浆 ET- 1较对照组显著升高 ,NO/ ET- 1显著降低 (P<0 .0 1)。血管内皮功能与总胆固醇 (TC)、低密度脂蛋白 (L DL - C)水平均呈负相关关系 (r=- 0 .4 1、 - 0 .6 6 ,P均 <0 .0 1) ,与高密度脂蛋白 (HDL - C)呈正相关 (r=0 .6 2 ,P<0 .0 5 )。结论 :AS患者存在血管内皮依赖性舒张功能障碍 ,超声是评价血管内皮功能简便可靠的方法     

阿托伐他汀对混合型高脂血症患者血管内皮依赖性舒张功能的影响

目的　观察阿托伐他汀对混合型高脂血症患者血管内皮依赖性舒张功能的影响。方法　 60例混合型高脂血症患者进行 8周阿托伐他汀片 10mg/d ,口服治疗 ,60例健康人群为对照组 ,治疗前后测定血脂以及用超声多普勒测定肱动脉血管内径、血流量以及反应性充血和含服硝酸甘油片后肱动脉内径和血流量变化。 2 8例经阿托伐他汀治疗 8周后血脂正常的患者停药 4周、8周 ,再次测定血脂以及肱动脉血管内径和血流量。结果　混合型高脂血症患者血管内皮依赖性舒张功能明显受损 (P <0 .0 0 1) ,而对硝酸甘油反应两组无差异 (P >0 .0 5 ) ,阿托伐他汀治疗 8周后血清TG、TC、LDL C、ApoB显著下降 ,对肱动脉内皮依赖性舒张功能较治疗前明显改善 (P <0 .0 0 1) ,停药后 4周、8周肱动脉血管内皮依赖性舒张功能明显下降 (P <0 .0 0 1) ,而治疗前后肱动脉内径以及对硝酸甘油的反应无变化。结论　阿托伐他汀治疗混合型高脂血症疗效明显 ,并显著改善肱动脉内皮依赖性舒张功能 ,这一作用源于其对内皮细胞的直接作用 ,可能独立于降脂作用之外     

高血压患者血管内皮标志物与内皮依赖性血管舒张功能的关系

目的探讨高血压患者血管内皮标志物与内皮依赖性血管舒张功能的关系。方法用放射免疫分析法和酶联荧光免疫测定法检测56例高血压患者和32例正常对照组血浆内皮素(ET-1)和血管性假血友病因子(vWF),并用高分辨彩色多谱勒超声仪检测肱动脉内皮依赖性血管舒张功能。56例高血压患者按危险度分层,分为低/中危险度30例,高/极高危险度26例;其中50例用药物治疗后复查血浆ET-1、vWF和肱动脉内皮依赖性血管舒张功能。结果高血压组血浆ET-1、vWF水平显著高于正常对照组[(53.3±16.2)pg/mlvs(42.5±8.5)pg/ml,(158.2±28.6)%vs(130.6±35.2)%],高/极高危组明显高于低/中危组(P<0.001);高血压组肱动脉反应性充血诱导下血管内径舒张率较正常对照组明显减弱[(7.5±4.2)%vs(12.3±4.3)%],高/极高危组明显高于低/中危组(P<0.001),低/中危组也较正常对照组明显减弱(P<0.05)。经抗高血压药物治疗后,血浆内皮标志物和内皮依赖性血管舒张功能明显改善。相关分析显示,血浆内皮标志物和内皮依赖性血管舒张功能存在显著的负相关关系(P<0.01)。结论高血压患者存在血浆vWF、ET-1水平升高和内皮依赖性血管舒张功能障碍,且与靶器官的损伤相关;血浆内皮细胞标志物可反映内皮依赖性血管舒张功能。     

高分辨率超声检测血管内皮功能的临床应用

目的：应用高分辨率超声观察血脂康对血脂正常的冠心病患肱动脉的内皮依赖性舒张功能的改善作用。方法：应用高分辨率血管外超声技术对56例冠心病患（分为血脂康组和安慰剂组）治疗前后的血管内皮功能进行检测。结果：56例冠心病患治疗前肱动脉血管内皮舒张功能减低，8周后，血脂康组肱动脉血管内皮依赖性舒张功能较治疗前明显改善（P＜0．01）。安慰剂组则无明显差异（P＞0．05）。结论：高分辨率超声可应用于检测冠心病患的内皮依赖性舒张功能及药物治疗前后的改善情况。     

高分辨率超声检测非酒精性脂肪性肝病患者血管内皮依赖性舒张功能

目的 应用高频超声无创评价非酒精性脂肪性肝病(NAFLD)患者的血管内皮依赖性舒张功能.方法 分别选取34例NAFLD患者和30例健康对照者,应用高频超声分别测量静息状态下和加压反应后右肱动脉舒张末期内径,计算肱动脉内径变化率,同时检测体重指数、血糖、血脂、肝功能和c反应蛋白等指标并进行统计学分析.结果 NAFLD组与对照组间体重指数、空腹血糖、高密度脂蛋白、甘油三酯、丙氨酸氨基转移酶、C反应蛋白差异均有显著性(P<0.05),NAFLD组血管内皮依赖性舒张功能显著低于对照组(P<0.05).结论 NAFLD患者血管内皮依赖性舒张功能较正常人群减退,高频超声可早期发现患者血管内皮功能异常.     

糖尿病前期患者血管内皮舒张功能与血脂关系的超声研究

目的通过高频超声检测糖耐量低减（IGT）和空腹血糖调节受损（IFG）患者的血管内皮舒张功能，并探讨其与血脂的关系。方法选择经临床诊断为IGT，IFG的患者各20例，同时选择健康人群30例作为对照。采用高频超声测定肱动脉内皮依赖性和非内皮依赖性舒张功能。同时测定空腹血糖、总胆固醇（TC）、三酰甘油（TG）、高密度脂蛋白胆固醇（HDL）及低密度脂蛋白胆固醇（LDL）。结果IGT及IFG患者空腹血糖，TC，TG，LDL—C较正常对照组增高（P〈0．05），反应性充血后肱动脉内径变化百分率较正常对照组降低（P〈0.05）。硝酸甘油介导的血管扩张肱动脉内径变化百分率在各组问无显著差异性（P〉0．05）。糖尿病前期患者肱动脉血管内皮依赖性舒张功能与血糖、TG水平呈明显负相关。结论糖尿病前期患者存在着血糖、血脂异常和血管内皮依赖性舒张功能障碍，且血管内皮舒张功能与血糖、TG水平密切相关。     

2型糖尿病一级亲属血管内皮依赖性舒张功能和血浆内皮素的变化

目的观察2型糖尿病糖耐量正常一级亲属(FDR s)血管内皮功能受损情况及血浆内皮素(ET-1)水平的变化。方法选择61例糖耐量正常的2型糖尿病一级亲属及39例健康对照者,测定其血管内皮功能、ET-1水平,空腹胰岛素(FINS)及血脂等。结果FDR s组血浆ET-1水平显著高于对照组(P<0.05),由肱动脉反应性充血介导的血管舒张程度较对照组明显降低,具有显著性差异(P<0.05),而两组间由硝酸甘油介导的血管舒张程度和基础内径与对照组相比无显著性差异(P>0.05)。结论2型糖尿病糖耐量正常一级亲属存在血管内皮功能障碍。     

超声评价冠心病患者血管内皮舒张功能

目的 通过超声检测肱动脉内径评价冠心病患者肱动脉血管内皮舒张功能变化.方法 采用高分辨率超声检测稳定型心绞痛、不稳定型心绞痛、急性心肌梗死患者及正常对照组血流介导的肱动脉血管舒张功能和硝酸甘油介导的肱动脉血管舒张功能.结果 冠心病各组血流介导的血管舒张反应均较正常对照组降低（P〈0.05）.稳定型心绞痛组与正常对照组,硝酸甘油介导的血管舒张反应无显著性差异（P〉0.05）,而不稳定型心绞痛组和急性心肌梗死组硝酸甘油介导的血管舒张反应均低于正常对照组与稳定型心绞痛组（P〈0.05）.结论 冠心病患者存在内皮舒张功能损害,这种损害呈渐进性发展.     

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.