射频超声技术定量评价健康成人颈部动脉内-中膜厚度及弹性功能

目的观察影响健康成人颈总动脉内-中膜厚度(IMT)及弹性功能的相关因素及各项弹性参数的正常值范围。方法 184例志愿者根据年龄分为A组(20~29岁)、B组(30~39岁)、C组(40~49岁)、D组(50~59岁)及E组(60岁以上),应用超声射频信号血管内中膜分析技术(QIMT)和超声射频信号动脉僵硬度分析技术(QAS)获取双侧颈动脉IMT、顺应性指标(膨胀系数DC、顺应系数CC)及僵硬度指标(α系数、β系数、脉搏波传导速度PWV),分析各组间及两性间各项参数的差异及其关系。结果左、右侧颈总动脉IMT、DC、CC、α系数、β系数及PWV比较差异无统计学意义。不同性别受检者IMT、DC、α系数、β系数及PWV比较均无统计学意义,CC男性高于女性,差异有统计学意义(P﹤0.05)。双侧颈总动脉IMT、α系数、β系数及PWV与年龄呈正相关,而DC和CC与年龄呈负相关。结论应用射频超声技术能准确检测颈总动脉IMT和血管弹性,并分析其主要影响因素,为临床定量评估血管性能提供了新的方法。     

应用QIMT及QAS技术对中青年高血脂患者颈总动脉结构和功能的评估

目的 探讨超声射频信号血管内中膜分析(QIMT)技术及血管硬度定量分析(QAS)技术评价中青年高血脂患者颈总动脉内-中膜厚度(IMT)和血管弹性改变及血脂与血管弹性的关系.方法 分别获取70例高血脂组患者颈总动脉IMT和颈总动脉血管僵硬度参数:脉搏波传播速度(PWV)、僵硬度(β)、顺应性系数(CC),并与健康对照组进行对比分析.结果 高血脂组颈总动脉IMT、PWW、β高于对照组,CC低于对照组,差异有统计学意义(P<0.05),IMT、PWV及β数与总胆固醇呈正相关,相关系数分别为0.8102、0.8401及0.9492(P<0.001);CC与总胆同醇呈负相关,相关系数为-0.9391(P<0.001).结论 QIMT及QAs技术能够自动、实时、准确检测高血脂患者颈总动脉IMT和血管弹性的变化,可为临床评价动脉结构和功能提供较为准确的定量指标.     

2型糖尿病合并高脂血症患者颈动脉内膜-中层厚度与动脉弹性的相关性研究

目的 应用血管内中膜分析技术(QIMT)和动脉僵硬度分析技术(QAS)评价2型糖尿病合并高脂血症患者颈动脉内膜-中层厚度与弹性的相关性.方法 随机选取2型糖尿病合并高脂血症患者56例作为病例组,48例同期健康志愿者为对照组.应用QIMT和QAS技术对颈动脉进行检查,获得颈动脉的内膜-中层厚度(IMT)、顺应性系数(CC)、扩张性系数(DC)、僵硬度系数(β).病例组再根据IMT分组;IMT＜0.9 mm为病例1组,IMT≥0.9 mm为病例2组.结果 对照组、病例1组、病例2组的β、甘油三酯(TG)、低密度脂蛋白(LDL)、胆固醇(Ch)、糖化血红蛋白(GHb)、颈动脉IMT等指标差异有统计学意义(P＜0.05),对照组＜病例1组＜病例2组.对照组、病例1组、病例2组的DC、CC差异有统计学意义(P＜0.05),对照组＞病例1组＞病例2组.病例组的β与年龄、GHb、LDL和颈动脉IMT呈明显正相关,β与年龄r=0.811,P=0.000;β与GHbr=0.764,P:0.000;β与LDLr=0.732,P=0.000;β与颈动脉IMT r=0.729,P=0.000.结论 QIMT可较准确地测量颈动脉IMT,QIMT与QAS技术联合应用使颈动脉的解剖结构成像与功能成像有机地结合,可成为深入研究颈动脉早期结构和功能改变的有效手段.     

射频数据处理技术对缺血性脑梗死患者颈动脉结构和功能的评价

目的应用射频数据处理技术评价缺血性脑梗死患者颈总动脉形态结构和弹性功能的改变。方法缺血性脑梗死患者颈动脉无斑块组(A组)75例,有斑块组(B组)55例,正常对照组(C组)108例。应用QIMT技术和QAS技术获取各组颈总动脉内中膜厚度和血管僵硬度指数,并对其参数进行比较和相关分析。结果 1A组与B组的血管内中膜厚度(IMT)、弹性系数α、β、脉搏波传导速度(PWV)、局部收缩压(LOCPsys)均较C组高,顺应性系数(CC)均较C组降低;B组的IMT、α、β、PWV、LOCPsys均较A组高,CC较A组低,差异有统计学意义(P0.05)。2各弹性参数间有一定的相关性,尤其是α、β、PWV、CC间相关性明显。结论射频超声技术能够定量评价缺血性脑梗死患者颈总动脉形态结构和弹性功能的改变,为早期预防、治疗心脑血管疾病具有重要的临床应用价值。     

超声射频信号血管内中膜分析技术评价肥胖儿童颈动脉内中膜厚度

目的:应用超声射频信号血管内中膜分析(quality intima-media thickness,QIMT)技术测量肥胖儿童的颈动脉内中膜厚度(intima-media thickness,IMT),探讨肥胖儿童代谢异常状况与颈动脉IMT间的关系。方法:由1名高年资超声医师应用QIMT技术,测量32例肥胖儿童(肥胖组)和20名正常对照儿童(对照组)的双侧颈总动脉IMT。结果:肥胖组与对照组儿童的空腹血糖(FBG)、总胆固醇(TCH)及低密度脂蛋白(LDL)差异均无统计学意义(P>0.05);肥胖组儿童的三酰甘油(TG)高于对照组,差异有统计学意义(P<0.01),高密度脂蛋白(HDL)则明显低于对照组,差异有统计学意义(P<0.05);肥胖组儿童的颈总动脉IMT明显高于对照组,差异亦有统计学意义(P<0.01)。结论:肥胖儿童的颈动脉IMT已开始增加,并可合并高脂血症,提示动脉硬化(AS)是可在小儿时期得病、成人发病。超声检查颈动脉IMT简便、安全无创,可作为早期发现AS的一个良好的预报因子。     

内-中膜厚度和动脉僵硬度分析技术定量评价肥胖儿童颈动脉弹性

目的 探讨超声射频信号内-中膜厚度(QIMT)和动脉僵硬度分析技术(QAS)评价肥胖儿童颈动脉弹性的价值.方法 单纯性肥胖儿童106例,与正常儿童120例相对照.应用QIMT软件记录两组的颈动脉内膜-中层厚度(IMT),QAS软件测量颈动脉膨胀系数(DC)、顺应性系数(CC)、弹性系数(β)、脉搏波传导速度(PWV)、局部收缩压(LOC Psys)、局部舒张压(LOC Pdia)、反射波增强指数(AIX)、等容收缩期(ICP)、射血期(ED),分析两组之间各项参数的差异.结果 肥胖组儿童DC值明显低于对照组,而PWV、LOCPsys、LOC Pdia、AIX、ICP和ED明显高于对照组,差异有统计学意义(P＜0.05);QIMT、CC和β在两组间无明显差异.结论 应用QAS技术可在肥胖儿童颈动脉内中膜增厚之前检测出动脉弹性功能及心脏功能的改变,为临床早期诊断动脉硬化提供准确的手段.     

射频数据处理技术对单纯收缩期高血压患者颈总动脉结构和功能的评估

目的 探讨高频超声射频数据处理技术(RF-data)评价单纯收缩期高血压(ISH)患者颈总动脉内-中膜厚度(IMT)和血管弹性改变及脉压(PP)与血管弹性的关系.方法 比较39例ISH患者与41例正常人颈总动脉舒张期内径(Dd)、收缩期内径(Ds)、PP、IMT、颈总动脉扩张性(CD)、单点脉搏波传播速度(PWVβ)、僵硬度(β)的改变,并分析PP与CD、PWVβ、β之间的关系.结果 ISH组SBP、PP均显著高于对照组.ISH组颈总动脉Ds、Dd 、IMT、PWVβ、β显著高于正常对照组;而CD显著低于对照组( P<0.001) .ISH组PP与PWVβ呈显著正相关(r=0.298,P<0.05),PP与β呈显著正相关(r=0.291,P<0.05),而PP与CD相关性不显著.结论 RF-data技术能够自动、实时、准确检测ISH患者颈总动脉IMT和血管弹性的变化.ISH患者颈总动脉IMT和血管僵硬度明显高于健康者.随着脉压的增大,PWVβ增快,血管僵硬度增高.     

妊娠期高血压和子痫前期患者颈总动脉内中膜厚度与弹性相关性研究

目的：本研究旨在探讨妊娠期高血压和子痫前期患者颈总动脉内中膜厚度（IMT）与弹性的相关性。方法：妊娠期高血压组32例,子痫前期组26例,同期正常妊娠者40例作为对照组。应用内中膜分析技术（QIMT）和动脉僵硬度分析技术（QAS）对所有受检者右侧颈总动脉进行检查。获得颈总动脉的IMT、顺应性系数（CC）、扩张性系数（DC）和僵硬度系数（β）。结果：妊娠期高血压组、子痫前期组和对照组的β差异有统计学意义（P<0.05）,对照组<妊娠期高血压组<子痫前期组。妊娠期高血压组、子痫前期组和对照组的CC、DC两项指标差异有统计学意义（P<0.05）,对照组>妊娠期高血压组>子痫前期组。子痫前期组的IMT高于妊娠期高血压组和对照组,差异有统计学意义（P<0.05）,妊娠期高血压组和对照组的IMT差异无统计学意义（P>0.05）。妊娠期高血压和子痫前期患者的IMT与β呈明显正相关（r=0.86,P=0.000）,与CC、DC呈明显负相关（r=－0.81,r=－0.76,P=0.000）。结论：妊娠期高血压和子痫前期患者的颈总动脉的弹性已发生明显改变,且子痫前期患者颈总动脉的IMT也发生明显改变。妊娠期高血压和子痫前期患者颈总动脉的IMT与弹性存在明显相关性。     

吸烟患者颈动脉内膜中层厚度与动脉弹性的相关性研究

目的:应用血管内中膜分析技术(QIMT)和动脉僵硬度分析技术(QAS)评价吸烟患者颈动脉内膜一中层厚度与弹性的相关性。方法:随机选取吸烟患者(年龄<35岁)80例作为病例组,40例同期健康志愿者为对照组。应用QIMT和QAS技术对颈动脉进行检查,获得颈动脉的内膜一中层厚度(IMT)、顺应性系数(CC)、扩张性系数(DC)、僵硬度系数(β)。病例组再根据IMT分组;IMT<0.9mm为病例1组,1组患者再根据吸烟量分为1a组(烟龄小于5年,且<20支/d)及1b组(烟龄>5年,且>20支/d),IMT≥0.9mm为病例2组。结果:对照组、病例1a组、病例1b组,病例2组的DC、CC差异有统计学意义(P<0.05),对照组>病例1a组>病例1b组>病例2组。病例组的β与吸烟、颈动脉IMT呈明显正相关。β与吸烟量r=0.789,P=0.00;β与颈动脉IMTr=0.715,P=0.000。结论:QIMT可较准确地测量颈动脉IMT,QIMT与QAS技术联合应用使颈动脉的解剖结构成像与功能成像有机地结合,可成为深入研究颈动脉早期结构和功能改变的有效手段。     

下肢动脉粥样硬化闭塞症患者颈动脉僵硬度改变与左心室舒张功能关系的超声评价

目的 应用超声技术评价下肢动脉粥样硬化闭塞症(AS)患者左侧颈动脉僵硬度改变与左室舒张功能的关系.方法 ①32例AS患者及34例健康志愿者,应用超声射频信号动脉僵硬度分析(quality arterial stiffness,QAS)技术分析其颈动脉僵硬度参数:扩张性系数(CC)、扩张性(DC)、僵硬度参数(α、β)和脉搏波传导速度(PWVβ).②二维超声心动图及组织多普勒技术测量左室结构和功能参数:舒张末期室间隔厚度(IVSd)、舒张末期左室内径(LVDd)、舒张末期左室后壁厚度(PWd)、左室射血分数(EF)、二尖瓣环收缩期峰值速度(s')、二尖瓣环舒张早期峰值速度(e ')、Tei指数、二尖瓣舒张早期血流峰速E与二尖瓣环舒张早期峰值速度e'比值(E/e ').将上述参数进行比较并与颈动脉僵硬度参数进行相关分析.结果 ①AS组DC、CC低于对照组,α、β、PWVβ高于对照组,差异有统计学意义(P＜0.05);②AS组IVSd、PWd大于对照组,s '、e'低于对照组,Tei指数、E/e'高于对照组,差异有统计学意义(P＜0.05).EF两组间差异无统计学意义(P＞0.05);③e '与DC、CC呈正相关(r =0.39、0.36,P＜0.01),与α、β和PWVβ呈负相关(r=-0.42、-0.42、-0.49,P＜0.01);Tei指数与DC、CC呈负相关(r=-0.50、-0.52,P＜0.01),与α、β和PWVβ呈正相关(r =0.58、0.58、0.62,P＜0.01);E/e'与CC呈负相关(r=-0.27,P＜0.05),与PWVβ呈正相关(r=0.28,P＜0.05).s'、EF与颈动脉僵硬度参数均无明显相关(P＞0.05).结论 下肢动脉粥样硬化闭塞症时左侧颈动脉僵硬度增加,左室收缩及舒张功能受损;颈动脉僵硬度与左室舒张功能存在相关性,动脉僵硬程度能反映左室舒张功能的变化.     

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.