二维斑点追踪技术评价初发型心绞痛患者的左房节段功能

目的应用二维斑点追踪显像（speckle tracking imaging,STI）技术评价初发型心绞痛患者的左房壁各节段功能。方法选择50例明确诊断为初发型心绞痛患者及40名正常人测定其左房被动射血分数（LAPEF）和左房主动射血分数（LAAEF）,应用STI技术测定左房壁各节段（后侧壁、房间隔、侧壁、前壁、下壁）应变及应变率曲线,获取左室收缩期左房壁各节段峰值应变（Ss）及应变率（SRs）,左室舒张早期左房壁各节段峰值应变率（SRe）,左室舒张晚期左房各节段峰值应变率（SRa）。结果心绞痛组较正常对照组,左房存储功能指标：各节段Ss均减低,SRs减低,左房最小容积（LAVmin）显著增大;左房管道功能指标：SRe、LAPEF显著减低;左房辅泵功能指标：左房前壁及下壁SRa显著减低。LAAEF及余左房壁SRa无统计学差异。结论初发型心绞痛患者左房管道功能明显减低,存储功能增强,泵功能部分受损。二维斑点追踪技术可以评价初发型心绞痛患者左房壁各节段的功能。     

二维斑点追踪成像评价蒽环类抗肿瘤药对乳腺癌患者左房功能的影响

目的探讨二维斑点追踪成像(STI)评价蒽环类抗肿瘤药(ATC)对乳腺癌左房功能的影响。方法 40例乳腺癌患者术后行化疗为化疗组,30例乳腺癌患者术后未化疗为对照组。应用Simpson法在心尖双平面测量左房最小容积(LAVmin)、最大容积(LAVmax)及P容积(LAVp),计算左房总排空分数(LATEF)、被动射血分数(LAPEF)及主动射血分数(LAAEF)。应用STI于心尖四腔心切面测量左房收缩期峰值应变率(SRs)、舒张早期峰值应变率(SRe)、舒张晚期峰值应变率(SRa),并计算其平均峰值(m SRs、m SRe、m SRa)。结果化疗组LATEF、LAPEF、LAAEF、m SRs、m SRe、m SRa较对照组均减低(均P0.05)。两组LATEF与m SRs、LAPEF与m SRe、LAAEF与m SRa均呈正相关(r分别为0.859、0.866、0.882,P0.001)。结论使用ATC乳腺癌患者左房功能发生改变,表现为储备功能、管道功能及泵功能减低。STI与左房容积指标有良好的相关性,能够准确评价左房功能。     

超声二维斑点追踪技术评价缩窄性心包炎患者左房功能

目的 应用超声斑点追踪技术(STE)评价缩窄性心包炎(CP)患者左房功能,探讨其临床应用价值.方法 对36例CP患者应用Simpsons法计算左房被动射血分数和主动射血分数,应用斑点追踪技术测量左房侧壁及房间隔的二维应变及应变率.并与40例正常人比较.结果 (1)CP患者左房最小容积、左房被动射血分数、左房主动射血分数较对照组显著减低(P<0.05);(2)CP患者左房侧壁及房间隔处心肌应变(S)、收缩期应变率(SRs)、舒张早期应变率(SRe)较对照组显著减低;左房侧壁舒张晚期应变率(SRa)显著减低(P<0.05),房间隔处SRa较对照组无差异.结论 CP患者左房功能减低,心包粘连主要影响左房泵功能.二维斑点追踪技术可以准确评价CP患者左房功能.     

应变率成像评价不同左心室构型原发性高血压患者右心室局部功能

目的 探讨应变率成像技术检测不同左室构型原发性高血压(HBP)患者右室收缩、舒张功能的应用价值.方法 HBP患者38例,根据左室质量指数(LVMI)和相对室壁厚度(RWT)值分为左室正常构型(LVN)组和左室重构(LVR)组,对照组23例.获取各受试者心尖四腔观清晰组织速度成像(TVI)图存盘供脱机分析.测量三尖瓣环处心肌收缩期峰值运动速度(Vs)、舒张早期峰值运动速度(Ve)、舒张晚期峰值运动速度(Va),计算Ve/Va;右室游离壁中部心内膜下心肌收缩期峰值应变(Ss)、收缩期峰值应变率(SRs)、舒张早期峰值应变率(SRe)、舒张晚期峰值应变率(SRa),计算SRe/SRa.结果 与对照组比较,高血压LVN组患者三尖瓣环Vs和Ve差异无统计学意义,Ve/Va减低;与对照组及高血压LVN组比较,高血压LVR组患者Vs差异无统计学意义,Ve、Ve/Va均显著减低;与对照组比较,高血压LVN组、LVR组患者右室游离壁中部心内膜下心肌SRs差异无统计学意义,Ss、SRe、SRe/SRa均显著减低;与高血压LVN组比较,高血压LVR组患者SRs差异无统计学意义,Ss、SRe、SRe/SRa均显著减低.结论 HBP患者无论左室构型有无变化,其右室局部收缩、舒张功能已受损,应变率成像技术能准确评价其右室局部功能.     

三维斑点追踪技术评价2型糖尿病左心房功能

目的探讨三维斑点追踪技术(3D-STI)在评价2型糖尿病(T2DM)患者左心房功能的应用价值。方法收集40例常规超声心动图测量心功能及心脏大小正常的T2DM患者作为病例组,另收集40例健康志愿者作为对照组。应用三维斑点追踪技术(3D-STI)测量收缩期、舒张早期、舒张晚期左心房整体长轴应变(3D-Ss,3D-Se,3D-Sa),采用二维斑点追踪技术(2D-STI)测量收缩期、舒张早期、舒张晚期左心房整体长轴应变(Ss,Se,Sa)及整体长轴应变率(SRs,SRe,SRa)。结果与对照组相比,T2DM患者3D-Ss、3D-Se、SRs及SRe减低(P0.05),3D-Sa、SRa增高(P0.05),Ss、Se及Sa差异均无统计学意义(P0.05)。结论 3D-STI能够评价T2DM患者左心房功能的改变,且较2D-STI更早发现左心房功能改变。     

速度向量成像技术对左室不同构型的维持性血液透析患者左心房功能的临床研究

目的 运用速度向量成像技术(VVI)分析不同左室构型的维持性血液透析（MHD）患者的左心房功能。方法 分析117名MHD患者和30名正常人的心尖四腔心切面图像,获得左房整体收缩峰值应变（Ss）及峰值应变率（SRs）,舒张早期峰值应变(Se)及峰值应变率(SRe),舒张晚期峰值应变(Sa)及峰值应变率(SRa)。结果 与对照组比较,病例组的Ss、SRs、Se、SRe均减小（均P＜0.05）,正常构型组的Sa、SRa均增大（均P＜0.05）,向心性肥厚组、离心性肥厚组的Sa、SRa均减小（均P＜0.05）;与正常构型组、向心性重构组比较,向心性肥厚组、离心性肥厚组的Ss、SRs、Se、SRe、Sa、SRa均明显降低（均P＜0.05）。MHD患者左房应变及应变率参数Ss、SRs、Se、SRe、Sa、SRa与E/e呈负相关（均P＜0.01）。结论 MHD患者左心房功能减退,VVI技术可以简便、快捷、准确地评价MHD患者左心房功能变化,为早期实施临床干预提供客观依据。     

正常人群房间隔应变率成像特点的研究

目的 分析正常人房间隔应变率成像的特点.方法 应变率成像定量分析40例正常人房间隔应变率,测量应变率曲线与应变曲线的左室收缩期、舒张早期和舒张晚期参数,观察彩色曲线M-型变化特征.结果 正常人群房间隔应变率曲线包括收缩期峰值SRs、舒张早期峰值SRe、舒张晚期峰值SRa,房间隔应变曲线包括零初长Ss波、舒张早期Se波切迹,平台期、舒张晚期Sa波,彩色曲线M-型可形象直观的反映房间隔运动变化.结论 房间隔应变率成像可以直接而形象的反映心房的形变,并与左房功能密切相关.     

实时三维超声及斑点追踪技术评价心房颤动患者射频消融术前后左心房功能

目的 应用实时三维超声心动图(RT-3DE)和斑点追踪显像技术(STI)评价Carto标测系统引导下的环肺静脉消融术治疗心房颤动对左房功能的近期影响。方法 对30例因阵发性心房颤动行消融治疗的患者于术前、术后3d和术后3个月进行超声心动图检查。应用RT-3DE计算左房最大容积(LAVmax)、左房最小容积(LAVmin)、左房收缩前容积(LAVp)、左房被动射血分数(LAPEF)和左房主动射血分数(LAAEF);应用STI技术获取左房各壁各节段的应变率曲线,分别测量左室收缩期的左房峰值应变率(SRs)、左室舒张早期的左房峰值应变率(SRe)、左室舒张晚期的左房峰值应变率(SRa)。结果 与术前相比,射频消融术后3d左房各壁各节段SRs、SRe和SRa均降低;术后3个月左房前壁、下壁、房间隔各节段SRa和SRe增高,SRs无明显差异,LAVmax和LAVp减小,LAPEF和LAAEF增高。结论 环肺静脉消融术式成功的患者在术后3d左房功能处于“恶化期”,术后3个月左房辅泵功能和管道功能增高。     

应变率成像评价不同构型高血压病患者左房功能

目的探讨应变率成像（SRI）技术评价不同构型高血压病患者左房功能的价值。方法采用应变率成像技术获取58例原发性高血压患者[正常构型组（LVN）28例,左室重构组（LVR）30例]和30例正常人左室舒张早期、房缩期、左室收缩期峰值应变率（SRe、SRa和SRs）,计算E/A比值。结果E/A在高血压各组均小于1;LVN组、EH组SRs较CR组、CH组减低（P〈0.05）;高血压各组SRe较正常组减低,且LVR组小于LVN组（P〈0.05）。结论SRe、SRa和E/A能敏感反映高血压病早期左房做功的增加。     

斑点追踪评价正常成人右室长轴心肌形变能力

目的应用斑点追踪技术定量分析正常成人右室局域心肌形变能力,并探讨年龄对形变能力的影响。方法应用斑点追踪成像技术测量75例健康成人的右室游离壁各节段心肌应变及应变率,在二维应变的模式下于心尖四腔观上勾画右室心内膜面,测量并记录右室游离壁基底段、中段及心尖段收缩期峰值应变(ε)、收缩期峰值应变率(SRs)、舒张早期峰值应变率(SRe)、舒张晚期峰值应变率(SRa)及舒张早期峰值应变率与舒张晚期峰值应变率的比值(SRe/SRa),比较各节段间变化规律及各指标随年龄增加的变化规律。结果右室基底段ε、SRs、SRe、SRa显著高于心尖段,SRs、SRe高于中段,SRe/SRa各节段间无差异。SRe随年龄增长而轻度减低,与年龄呈负相关(r=-0.229～-0.301,P<0.05),SRa随年龄增长而增加,与年龄呈显著正相关(r=0.438～0.525,P<0.01),SRe/SRa随年龄增长而明显减低,与年龄呈显著负相关(r=-0.466～-0.614,P<0.01)。结论斑点追踪技术可以准确、客观的评估右室长轴心肌收缩期、舒张期形变的能力。右室舒张期形变能力随年龄增加而减低。     

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.     

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.     

Evidence-Based Pain Management and Palliative Care in Issue Four for 2009 of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly. Issue 4 for 2009 contains 4027 complete reviews, 1906 protocols for reviews in production, and 11447 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 600,000 randomized controlled trials, and 12,200 cited papers in the Cochrane methodology register. The health technology assessment database contains over 7500 citations. This edition of the Library contains 90 new reviews, of which 19 have potential relevance for practitioners in pain and palliative medicine.     

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.     

Molecular characterization of virulence and antimicrobial resistance profile of Shigella species isolated from children with moderate to severe diarrhea in northeastern Brazil

Molecular characterization of virulence and antimicrobial resistance profiles were determined for Shigella species isolated from children with diarrhea in Fortaleza, Brazil. Fecal specimens were collected along with socioeconomic and clinical data from children with moderate to severe diarrhea requiring emergency care. Shigella spp. were isolated by standard microbiological techniques, and we developed 4 multiplex polymerase chain reaction assays to detect 16 virulence-related genes (VRGs). Antimicrobial susceptibility tests were performed using disk diffusion assays. S. flexneri and S. sonnei were the predominant serogroups. S. flexneri was associated with low monthly incomes; more severe disease; higher number of VRGs; and presence of pic, set, and sepA genes. The SepA gene was associated with more intense abdominal pain. S. flexneri was correlated with resistance to ampicillin and chloramphenicol, whereas S. sonnei was associated with resistance to azithromycin. Strains harboring higher numbers of VRGs were associated with resistance to more antimicrobials. We highlight the correlation between presence of S. flexneri and sepA, and increased virulence and suggest a link to socioeconomic change in northeastern Brazil. Additionally, antimicrobial resistance was associated with serogroup specificity in Shigella spp. and increased bacterial VRGs.