彩色多普勒超声在原发性高血压患者颈动脉粥样硬化中的临床应用价值

目的 探讨彩色多普勒超声在原发性高血压患者颈动脉粥样硬化中的临床诊断及应用价值.方法 选择100例原发性高血压患者(观察组)和100例健康体检正常者(对照组),分析比较两组颈动脉彩色多普勒超声检查结果 .结果 观察组患者颈总动脉(CCA)及颈内动脉(ICA)的收缩期峰值流速(PSV)、舒张末期血液速度(EDV)均显著低于对照组,搏动指数(PI)及阻力指数(RI)均显著高于对照组,差异有统计学意义(P<0.05).观察组患者颈动脉主干及分叉内膜中层厚度(IMT)均厚于对照组,差异有统计学意义(P<0.05).观察组患者颈动脉检出软斑50例、硬斑22例和混合性斑块12例,斑块检出率为84.00%;对照组颈动脉检出软斑10例、硬斑3例和混合性斑块4例,斑块检出率为17.00%;观察组颈动脉斑块检出率及物理特征与对照组比较,差异有统计学意义(P<0.05).观察组患者颈动脉狭窄程度大于对照组,差异有统计学意义(P<0.05).结论 彩色多普勒超声能有效识别原发性高血压患者颈动脉粥样硬化的位置及斑块性质,评估血管狭窄程度及血流动力学,为临床治疗提供重要依据.     

糖尿病患者颈动脉彩超检测的应用价值

目的 应用彩色多普勒超声检测Ⅱ型糖尿病患者颈动脉病变情况。方法 对117例糖尿病患者双侧颈动脉检测结果与对照组127例健康人群进行比较分析。结果 糖尿病组Ⅲ级粥样斑块检出率(44.4％)与对照组(9.6％)有明显差异(P<0.01);糖尿病组血流速度降低、血管阻力指数及搏动指数增高,与对照组存在差异(P<0.05)。结论 糖尿病患者颈动脉病变以粥样硬化斑块形成、血流减速、血管阻力增高为主要特点。彩超可直观反映病变的分期、轻重程度,在糖尿病血管病变的诊断中具有重要的实用价值。     

探讨老年高血压病患者血压昼夜节律变化与颈动脉斑块的关系

目的探讨老年高血压病患者血压昼夜节律对颈动脉粥样硬化斑块的影响。方法将130例老年原发性高血压病患者按照24h动态血压检测结果分为两组：非杓形组62例,杓形组68例;超声检测颈动脉粥样硬化斑块程度及性质,并对斑块进行分级。结果非杓形组颈动脉粥样硬化斑块检出率为93．55％,高于杓形组斑块检出率77．94％（P〈0．05）;非杓形组的斑块程度分级高于杓形组（P〈0．05）;非杓形组颈动脉斑块软斑及溃疡斑多于杓形组（P〈0．01）。结论血压昼夜节律异常是颈动脉粥样硬化斑块形成的危险因素。     

高频超声在高血压患者颈动脉粥样硬化中的诊断价值

目的探讨高频超声在高血压患者颈动脉粥样硬化中的诊断价值。方法使用高频超声诊断仪分别对110例高血压患者（高血压组,其中Ⅰ级30例,Ⅱ级35例,Ⅲ级45例）及100例正常健康体检者（对照组）的颈动脉内-中膜厚度（IMT）和斑块形成进行检测。结果高血压组各级患者颈动脉IMT及斑块发生率较对照组均明显增高,差异有统计学意义（P〈0.01）;高血压组IMT逐级增厚,斑块检出率逐级增高,其中高血压Ⅲ级IMT最厚,斑块检出率最高,与高血压Ⅰ、Ⅱ级比较差异均有统计学意义（P〈0.05或P〈0.01）。结论高频超声可清晰显示颈动脉内-中膜厚度及斑块形成情况,对高血压动脉粥样硬化的防治具有重要意义。     

老年高血压患者颈动脉超声检测

目的:探讨彩色多普勒超声对老年高血压患者的颈动脉变化特点。方法:应用彩色多普勒超声诊断仪对100例原发性老年高血压患者双侧颈动脉超声观察,并与50例健康老年人进行对照检查分析。结果:(1)老年人高血压病组颈动脉阳性检出率为84％,斑块检出率为67％,明显高于健康老年人组,两组有显著差异(P<0.01);(2)老年高血压病组SPV、EDV较健康老年人组降低,血流动力学变化以血流减慢为主;(3)颈动脉血管病变彩色多普勒多有相应特征性改变。结论:老年高血压患者颈动脉病变多以动脉硬化粥样斑块形成、血流减慢、血管阻力指数增高和顺应性降低为主要特点。彩色多普勒超声直观、动态地了解颈动脉硬化程度及粥样斑块性质,有助于临床的诊治,对预防脑卒中的发生也具有重要的实用价值。     

超声评价非酒精性脂肪肝患者颈动脉病变的价值

目的探讨超声评价不同程度非酒精性脂肪肝(NAFLD)患者颈动脉形态学及血流动力学的价值。方法将90例NAFLD患者按脂肪肝程度分为3组,即脂肪肝轻度、中度和重度组,每组30例。各组行颈动脉超声检测颈动脉形态学及血流动力学指标。结果与轻度组比较,中、重度组左右两侧颈总动脉主干及膨大处内中膜厚度(IMT)增厚,斑块检出率增高,收缩期峰值血流速度(PSV)﹑舒张末期血流速度(EDV)及平均血流速度(MV)降低,阻力指数(RI)增高,差异均有统计学意义(均P<0.05);与中度组比较,重度组左右两侧颈总动脉主干及膨大处IMT增厚,斑块检出率增高,PSV﹑EDV及MV降低,RI增高,差异均有统计学意义(均P<0.05)。NAFLD患者的脂肪肝程度与PSV﹑EDV及MV呈显著负相关(r=0.46、0.51及0.53,P<0.01),与双侧颈总动脉主干及膨大处IMT、双侧颈动脉斑块检出率以及RI呈显著正相关(r=0.61、0.62、0.48及0.57,P<0.01)。结论颈动脉超声检查可评价NAFLD患者颈动脉病变的程度,并可辅助NAFLD分级。     

彩超在高血压患者颈动脉粥样硬化与血流动力学变化评价中的应用

以我院86例高血压患者为观察组,86例健康体检者为对照组,两组均接受颈动脉彩超检查,比较颈总动脉内膜-中层厚度、颈总动脉斑块和血流动力学指标。结果观察组颈总动脉内膜-中层厚度0.88±0.18mm,斑块检出率67.4%,对照组颈总动脉内膜-中层厚度0.58±0.24mm,斑块检出率9.3%,组间比较差异显著(P<0.05);观察组收缩期峰值血流速度、舒张末期血流速度、平均流速明显低于对照组(P<0.05),血管阻力指数、血管搏动指数明显高于对照组(P<0.05)。彩超检测可较准确反映颈动脉损害情况,对颈动脉粥样硬化的诊断有较好的指导价值。     

超声在评估老年高血压病患者脉压和昼夜节律异常与颈动脉斑块形成关系中的应用

目的：探讨老年高血压病患者脉压及血压昼夜节律异常对颈动脉粥样硬化斑块形成的影响。方法150例老年原发性高血压患者根据24 h动态血压检测结果,按照昼夜血压下降率分为2组,＜10%为非杓型组（72例）,≥10%为杓型组（78例）。超声检测颈动脉粥样硬化斑块程度及性质,并对斑块进行分级。计算不同脉压水平[≤60 mmHg（1 mmHg=0.133 kPa）、61~89 mmHg、≥90 mmHg]高血压患者颈动脉斑块检出率。结果杓型组高血压病患者中检出斑块61例,位于双侧20例,右侧15例,左侧26例,斑块检出率为78%（61/78）;非杓型组高血压病患者中检出斑块68例,位于双侧38例,右侧14例,左侧16例,斑块检出率为94%（68/72）。非杓型组斑块检出率高于杓型组,差异有统计学意义（χ^2=8.07,P＜0.01）。杓型组中硬斑30例、软斑13例、混合斑8例,非杓型组中硬斑12例、软斑24例、混合斑32例;杓型组中斑块分级为0级、1级、2级、3级的患者分别为17、33、13、15例,非杓型组中0级、1级、2级、3级的患者分别为6、8、25、33例。2组患者斑块性质及斑块分级的差异均有统计学意义（χ^2=5.29、8.75,P均＜0.01）。43例患者脉压≤60 mmHg,斑块检出率为72%（30/43）;65例脉压为61-89 mmHg,斑块检出率为88%（57/65）;42例脉压≥90 mmHg,斑块检出率为98%（41/42）。脉压≤60 mmHg、61-89 mmHg、≥90 mmHg的高血压病患者斑块检出率间差异有统计学意义（χ^2=11.65,P=0.00）。结论脉压增大及血压昼夜节律异常是颈动脉粥样硬化斑块形成的危险因素。     

高血压患者昼夜节律异常与下肢动脉硬化的关系

目的 观察高血压患者血压昼夜节律异常与下肢动脉硬化的关系.方法 对高血压患者行24h无创动态血压监测,根据夜间血压下降率选择杓型组患者29例,非杓型组患者32例,反杓型组30例.采用飞利浦超凡C5-2B超仪测定股动脉、腘动脉、胫后动脉内径,内—中膜厚度及粥样斑块.结果 非杓型组较杓型组患者下肢动脉舒张期内径增宽,内—中膜增厚,差异有统计学意义(P＜0.05)斑块检出例数虽无明显差异,但仍有增多趋势.反杓型组与杓型组相比,上述检测项目差异均有统计学意义(P＜0.01).结论 高血压患者血压昼夜节律异常与动脉硬化程度直接相关,治疗高血压时应调整用药时间,是血压昼夜节律恢复正常.     

彩色多普勒超声检测老年高血压患者颈动脉重构与血流动力学变化

目的 探讨老年高血压患者颈动脉结构及血流动力学特征.方法 老年高血压患者81例,按高血压类型分为单纯收缩期高血压组42例(A组),收缩压和舒张压均增高组39例(B组).对照组为30名健康老年人.二维超声测量颈总动脉内膜-中层厚度(IMT)、收缩期、舒张期内径,观察颈总动脉斑块情况;脉冲多普勒超声测量颈总动脉收缩期峰速度(PSV)、舒张末期流速(EDV)、平均流速(Vmean)、阻力指数(RI)、搏动指数(PI).结果 与对照组比较,A、B组颈总动脉IMT、僵硬度、RI升高(P<0.01),扩张性、EDV、Vmean降低(P均<0.05),A组PI升高(P<0.01),B组PSV降低(P<0.05);A组颈总动脉僵硬度、PSV、RI、PI高于B组(P均<0.05),扩张性和EDV低于B组(P<0.01);A、B组斑块发生率均高于对照组(P均<0.05);收缩压、脉压与颈总动脉内径、IMT、EDV、Vmean、RI、PI密切相关.结论 老年高血压患者颈动脉发生重构及血流动力学改变,单纯收缩期高血压患者血管壁顺应性差于收缩压和舒张压均增高患者.收缩压及脉压对颈动脉重构及血流动力学影响较大.     

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.