彩色超声多普勒评价颈动脉粥样硬化与脑梗死发生的相关性

目的评价颈动脉粥样硬化与脑梗死的相关性。方法对178例脑梗死患者进行颈动脉彩色多普勒检测。结果脑梗死患者颈总动脉和颈内动脉内膜-中层厚度(IMT)分别为(1.27±0.24),(0.98±0.09)mm,与对照组犤0.79±0.07),(0.72±0.08)mm犦比较差异有非常显著性意义(P<0.01)。脑梗死组颈总动脉及分叉、颈内动脉的粥样硬化斑块发生率较对照组明显增高(P<0.01)。椎基底动脉系统脑梗死患者锁骨下动脉起始处的斑块发生率明显多于颈动脉系统脑梗死患者(P<0.01)。脑梗死患者颈内动脉的IMT值与血浆总胆固醇、三酰甘油、纤维蛋白原的含量成正相关(P<0.01)。结论彩色多普勒可作为颈动脉粥样硬化检测的可靠方法。颈动脉粥样硬化的形成与脑梗死的发病密切相关。     

糖尿病患者颈动脉内膜中膜厚度与血管内皮功能相关性彩色多普勒超声研究

目的应用彩色多普勒超声观察糖尿病患者颈动脉内膜中膜厚度(IMT)并探讨其血管内皮功能及两者的相关性.方法对40例糖尿病患者,测定其颈动脉内膜中膜厚度及反应性充血时和舌下含服硝酸甘油后肱动脉内径的变化,并对它们进行相关性分析.结果糖尿病患者IMT(1.03±0.04mm)较正常对照组(0.77±0.03mm)明显增厚(P＜0.001).反应性充血时肱动脉内径的扩张程度为(2.92±2.65%),与正常对照组相比在统计学上有显著性差异(P＜0.001).舌下含服硝酸甘油后肱动脉内径的变化在两组间有显著性差异(P＜0.001).颈动脉内膜中膜厚度与反应性充血时和舌下含服硝酸甘油后肱动脉内径的变化呈显著负相关(r＝-0.525,P＜0.001,r＝-0.41,P＜0.01).结论糖尿病患者存在明显的血管内皮依赖性及非依赖性舒张功能的损伤.内皮功能的紊乱引起血管壁重构、肥厚、斑块形成.因此糖尿病患者的内皮功能损伤促进了功能粥样硬化的产生并加速了动脉粥样硬化的进程.     

运动对Apo E基因敲除小鼠主动脉易损斑块和MMP9、Tenascin-C的影响

摘要 目的：探讨长期中等强度负荷耐力运动对载脂蛋白（Apo E）基因敲除小鼠主动脉粥样硬化易损斑块的影响和对主动脉基质金属蛋白酶9（MMP9）、腱糖蛋白-C（tenascin-C）表达的调控作用。 方法：40只6周龄Apo E基因敲除小鼠随机分为运动干预组（20只）和对照组（20只）。运动干预组给予长期中等强度的负荷耐力跑台运动干预32周;一般对照组未予以特殊干预。实验结束后评估两组小鼠主动脉动脉粥样硬化斑块面积和动脉粥样硬化斑块脂核面积的变化情况、采用偏振光的方法测定主动脉胶原含量的变化,采用免疫组化方法测定主动脉MMP9、tenascin-C的表达。 结果：长期中等强度负荷耐力运动组主动脉粥样硬化斑块面积、 斑块脂核面积及埋藏纤维帽数目均显著下降 [（70932±4669）μm2 vs （57247±3982）μm2,P＜0.01;（21279±2104）μm2 vs （57247±3982）μm2,P＜0.01;1.03±0.42 vs 5.22±0.77,P＜0.01]、主动脉壁胶原含量显著增加（67.41%±7.88% vs 21.22%±8.63%,P＜0.01）,主动脉MMP9（47.02±8.55 vs 36.67±4.51,P＜0.01）、tenascin-C的表达显著低于对照组（39.72±6.89 vs 28.86±2.90,P＜0.01）。 结论：长期中等负荷耐力运动可显著下调Apo E基因敲除小鼠主动脉MMP9、tenascin-C的表达并具有稳定主动脉易损斑块的作用。     

急性脑梗死患者动脉粥样硬化程度与C反应蛋白的相关性研究

目的 研究急性脑梗死患者血清C反应蛋白(C-reactive protein,CRP)浓度变化与动脉粥样硬化(atherosclerosis,AS)程度、斑块稳定性关系.方法 急性脑梗死患者共416例,经颈动脉彩超确诊的颈动脉内膜厚度(carotid intima-media thickness,IMT)增厚患者284例,非IMT增厚患者132例;284例IMT增厚患者根据颈动脉斑块状态分为管壁增厚组、硬斑块组、混合性斑块组和软斑块组;416例患者根据脑梗死病灶大小分为腔隙性脑梗死组、小面积脑梗死组和大面积脑梗死组.采用免疫散射比浊法测定血清中CRP浓度,统计学分析IMT增厚组与非IMT增厚组、稳定斑块组与不稳定斑块组、不同面积腩梗死组之间CRP浓度的差别.结果 IMT增厚组较非IMT增厚组CRP浓度增高;不稳定性斑块组较稳定性斑块组CRP浓度增高;随着脑梗死面积增加,CRP浓度亦增高,差异有统计学意义(P<0.05).结论 CRP浓度与AS程度、斑块稳定性及脑梗死患者病情密切相关.     

颈动脉及股动脉内膜-中膜层厚度正常值的对比研究

目的探讨颈动脉粥样硬化与股动脉粥样硬化的超声诊断标准.方法根据125例正常健康者颈动脉及股动脉超声图像,测量颈动脉及股动脉内径(D)、颈动脉及股动脉内膜-中膜层厚度(IMT)、颈动脉及股动脉僵硬度(β)和最大剪切率(SRs).结果随年龄增加,颈动脉及股动脉IM T、D、β呈增加趋势,SRs降低;正常人颈动脉和股动脉IMT分别为(0.63±0.15)mm、(0. 68±0.21)mm,颈动脉及股动脉IMT上限分别为0.93mm、1.11mm.将正常人分为≥50岁组与< 50岁组,颈动脉上限分别为1.09mm、0.85mm;股动脉上限分别为1.26mm、0.98mm. 结论正常人颈动脉及股动脉的IMT、血管内径和僵硬度随年龄增加而增加.采用I MT≥1.2mm可用于诊断颈动脉及年龄<50岁股动脉粥样硬化斑块,对于50岁以上患者,股动脉粥样硬化斑块诊断标准取IMT≥1.3mm较为合适.     

急性脑梗死患者血浆同型半胱氨酸浓度与颈动脉粥样硬化的相关性

目的:探讨动脉粥样硬化性血栓性脑梗死与血浆同型半胱氨酸(Hcy)浓度及颈动脉粥样硬化(atherosclerosis,AS)的关系。方法:应用HPLC-FD法测定87例急性脑梗死患者和80例对照者血浆HCY浓度,应用彩色多普勒超声仪测量左右颈总动脉内膜中层厚度(carotidarteryintimal-medialwallthickness,IMT)。结果:病例组空腹血浆Hcy浓度(15.28±4.33)μmol/L较对照组(11.32±3.86)μumol/L高(t=6.28,P<0.001),两组中血浆Hcy升高者分别为31.0%(27/87)和6.3%(5/80),差异有显著性意义(χ2=14.966,P<0.001);病例组55例、对照组66例行颈动脉B超检测,左、右颈总动脉IMT差异均有显著性意义(t=3.647,4.118,P<0.001),颈AS斑块发生率差异有显著性意义(χ2=6.145,P=0.013),而颈动脉中-重度狭窄发生率差异无显著性意义(χ2=0.062,P=0.803)。结论:高HCY血症是脑梗死的独立危险因素,B超检测的颈AS与脑梗死相关。     

脑梗死患者颈动脉粥样硬化斑块与血浆脂联素水平的关系

目的：研究脑梗死患者颈动脉粥样硬化斑块与血浆脂联素水平的关系。方法：根据临床表现、影像学和颈动脉超声检查结果，将106例急性脑梗死患者分为有斑块组和无斑块组、稳定斑块组和不稳定斑块组等亚组，比较各亚组间血浆脂联素水平，同时与50例正常对照者比较。结果：①脑梗死患者血浆脂联素水平(5.7±1.8mg/L)低于正常对照者(8.8±2.4 mg/L)，差异具有统计学意义(P＜0.05)。②脑梗死患者颈动脉硬化发生率、颈动脉斑块发生率、颈动脉狭窄发生率（75.5％、65.1％、36.8％）均高于正常对照者（28.0％、20.0％、6.0％），差异具有统计学意义(P＜0.05)。③有斑块组血浆脂联素水平(5.2±1.2mg/L)低于无斑块组(7.0±1.4mg/L)，差异具有统计学意义(P＜0.05)；不稳定斑块组血浆脂联素水平(4.6±0.9mg/L)低于稳定斑块组(5.5±1.4mg/L)，差异具有统计学意义(P＜0.05)。结论：脑梗死患者低脂联素水平与颈动脉粥样硬化有一定关系，尤其与不稳定斑块形成密切相关。     

生长刺激表达基因2蛋白与动脉粥样硬化及脑梗死发病的关系研究

目的 探讨生长刺激表达基因2蛋白(growth stimulationexpressed gene 2,ST2)水平与动脉粥样硬化及脑梗死发病的关系。方法 选取脑梗死患者100例,其中患者心功能I～II级43例,III～IV级57例。健康体检者80例为对照组,检测所有研究对象血清ST2水平,应用颈动脉多普勒彩色超声检查颈动脉内膜-中层厚度(intimal-medial wall thickness,IMT)。结果 脑梗死组ST2水平和IMT明显高于正常对照组(t=12.385～15.374,均P<0.05)。脑梗死患者有斑块组血清ST2水平58.74±5.81 ng/ml,颈动脉内膜1.89±0.41 mm。无斑块组ST2水平18.31±3.38 ng/ml,颈动脉内膜1.12±0.31 mm。两组差异有统计学意义(t=37.614～21.531,均P<0.05)。心功能Ⅰ～Ⅱ级脑梗死患者组ST2水平22.53±2.95 ng/ml,心功能Ⅲ～Ⅳ级脑梗死患者组ST2水平65.32±3.65 ng/ml,两组差异有统计学意义(t=55.148,P<0.05)。结论 血清ST2水平与颈动脉粥样硬化关系密切,可作为脑梗死及有无动脉粥样硬化发生的检测指标。     

颈动脉粥样斑块稳定性与急性脑梗死发病机制关系的临床研究

目的探讨颈动脉粥样斑块稳定性及炎症反应与急性脑梗死之间的关系。方法对71例急性脑梗死患者(A组)、44例无症状颈动脉硬化患者(B组)和21例健康对照者(C组)进行研究,ELISA测定基质金属蛋白酶-9(MMP-9)、组织型基质金属蛋白酶抑制剂-1(TIMP-1)含量,免疫透射比浊法测定高敏C反应蛋白(hs-CRP)含量,应用彩色多普勒超声仪观测颈动脉内中膜厚度(IMT)、斑块类型及斑块形态。结果A组颈动脉IMT[(1.11±0.29)mm]和B组IMT[(1.14±0.26)mm]与C组[(0.77±0.15)mm]比较差异有统计学意义(P<0.05);A组颈动脉斑块以脂质型斑块(59.2%)为主,B组以纤维型斑块(32.9%)为主,A组斑块表面多呈不规则型。hs-CRP、MMP-9含量在A组[分别为(5.47±2.26)mg/L、(250.64±89.65)ng/ml]、B组[分别为(1.80±0.34)mg/L、(144.67±34.40)ng/ml]、C组[分别为(0.59±0.12)mg/L、(64.49±18.26)ng/ml]之间差异有统计学意义;TIMP-1含量在A组[(59.64±15.87)ng/ml]、B组[(73.48±21.22)ng/ml]和C组[(57.95±7.86)ng/ml]之间差异有统计学意义,但A组和C组间差异无统计学意义;A组hs-CRP与MMP-9(r=0.241,P=0.043)呈正相关。结论颈动脉粥样斑块稳定性与急性脑梗死有关,MMP-9、TIMP-1参与的炎症反应是影响颈动脉粥样斑块由结构性不稳定向功能性不稳定进展的重要机制。     

老年人脑梗死发病与颈动脉粥样硬化关系的研究

【目的】研究老年人脑梗死发病与颈动脉粥样硬化的关系。【方法】B超测定脑梗死患者 5 0例及32例对照组颈动脉内膜 -中膜厚度 (intimal mediathickness,IMT)、颈动脉狭窄程度及斑块状况 ,比较和分析有关资料。【结果】脑梗死组和对照组颈动脉粥样斑块的发生率 (% )分别为 80 % (4 0 / 5 0 ) ,明显高于对照组31.3% (10 / 32 ) (P <0 .0 1)。脑梗死组颈总动脉和颈内动脉IMT均值、斑块指数 (PI)均值及狭窄的发生率(% )分别为 0 .99± 0 .0 8、0 .96± 0 .0 7、2 .0 1± 1.0 4、80 ,对照组上述指标依次为 0 .75± 0 .0 5、0 .73± 0 .0 6、0 .4 2± 0 .18、31.3,两组相比差异有极显著性 (P <0 .0 1)。【结论】老年人颈动脉粥样硬化与脑梗死的发病机制有密切关系。     

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.