经静脉声学造影定量心肌局部血流量的实验研究

目的：研究应用自制声学造影剂进行心肌造影超声心动图（MCE）定量显示不同冠状动脉血流量时局部心肌血流量（MB）变化的能力，以及与放射性微球的心肌血流量间的关系。了解其用于评价微循环的价值。方法：开胸犬6条，取乳头肌短轴观，采用经静脉连续滴注造影剂的方法，分别在基础状态，静脉给予潘生丁造成的充血状态，左冠状动脉回旋支（LCx）不同程度狭窄状态下通过逐渐递增触发间歇进行MC，以公式y=A(1-e^βt）拟合感兴趣区的时间－强度化曲线，以A(反映心肌局部血容量）与β（反映心肌局部血流速度）的乘积代表MBF。在最后狭窄状态，于MCE结束后左房内注入放射性微球测量局部心肌血流量，结果：（1）应用递增触发间歇的方法可清晰准确显示局部心肌显影程度的变化。（2）充血状态下，随冠状动脉血流量下降，A．β（LCx）亦减低，每条犬的LCx冠状动脉血流量变化与LCx供血区的A．β（LCx）变化呈正相关(r值分别为0.92,0.83,0.96,0.66,0.83,0.82,P值分别为0.04,0.03,0.003,0.01,0.03,0.03)。（3）A．β（LCx）／A．β（LAD）与放射微球测得MBF（LCx）／MBF（LAD）相关（Y＝0．76X＋0．0.07,r=0.82,P=0.01)，结论：经静脉连续滴注自制声学造影剂对开胸犬行MCE可获得清淅的心肌造影图像，并能够定量反映开胸犬的心肌局部血流量变化。     

多巴酚丁胺负荷心肌声学造影评价冠状动脉狭窄

目的　为评价多巴酚丁胺负荷心肌声学造影 (MCE)诊断静息无血流限制冠脉狭窄的准确性。方法　在慢性冠脉狭窄闭胸犬模型上同步进行MCE和放射性微球测定心肌血流量 (MBF)。结果　负荷状态时 ,异常冠脉供血区 (MBF储备 <3)呈现灌注缺损 ,峰值声强度 (VI)较正常冠脉供血区低 (33± 13与 48± 14;P <0 0 1) ;且异常和正常冠脉供血区峰值VI比值 (0 7± 0 2 )与相应MBF比值呈良好的线性正相关 (r =0 86 ,P <0 0 0 0 1)。结论　多巴酚丁胺可作为一种负荷药物用于MCE评价冠脉狭窄     

对慢性闭胸犬评价潘生丁负荷心肌声学造影探测冠状动脉狭窄

目的 :为评价潘生丁负荷心肌声学造影 ( MCE)诊断静息状态无血流限制的冠脉狭窄的准确性。方法 :以安放“水膨胀式”缩窄器 ( Ameroid)的方法建立慢性多支冠脉狭窄犬模型 ,术后 7天～ 10天同步进行经外周静脉注射微泡法 MCE和放射性微球测定心肌血流量 ( MBF)。结果 :静息状态未见明显灌注缺损。负荷状态时 ,异常冠脉供血区 ( MBF储备 <3)呈现灌注缺损 ,峰值声强度 ( VI)较正常冠脉供血区低 ( 33± 13与 5 0± 12 ;P<0 .0 1) ;且异常和正常冠脉供血区峰值 VI比值 ( 0 .6± 0 .2 )与相应 MBF比值呈良好的线性正相关 ( r=0 .89,P<0 .0 0 0 1)。结论 :潘生丁负荷 MCE可用于临床定性和定量的评价静息状态无血流限制的冠脉狭窄     

应用间歇触发显像技术定量各节段心肌血流的可行性及准确性研究

目的　应用自制的声学造影剂 ,建立谐波能量多普勒间歇触发显像技术 (ITI)定量节段心肌血流量的完整方法 ,并评价该技术定量心肌血流 (MBF)的准确性和可行性。方法　取 6条开胸犬 ,显示乳头肌中部水平短轴切面 ,静脉连续滴注造影剂 ,分别在基础状态、静脉给予潘生丁造成的充血状态及充血状态下左冠状动脉回旋支 (LCx)不同程度狭窄状态进行心肌造影超声心动图 ,将左室壁分成前壁、侧壁、后壁、下壁、后间隔和前间隔 6个节段分析。在最后狭窄状态 ,于心肌声学造影 (MCE)结束后左房内注入放射性微球 (MIC)测量MBF ,并与ITI测值进行对比。结果　在各节段显像中 ,位于聚焦区附近的前间隔和后壁的显像成功率最高 ,均为 88% ( 2 9/ 3 3 ) ,位于近场的侧壁显像成功率最低 ,为 61% ( 2 0 / 3 3 )。标准化后ITI测量的后壁 /前壁、后壁 /侧壁及后壁 /前间隔的MBF比值与MIC测值相关 ,其中以后壁 /前间隔的相关性最强(r =0 .97,P <0 .0 0 1)。非缺血区ITI测得的MBF绝对值 (前壁、下壁、后间隔和前间隔 )和MBF比值 (前间隔 /前壁、前间隔 /下壁、前间隔 /后间隔 )与MIC测值相关有显著性 ,但相关性较差 (r =0 .5 2 ,P =0 .0 1和r =0 .44 ,P =0 .0 1)。在缺血区 (后壁和侧壁 ) ,ITI测得的MBF绝对值和MBF比值 (前间隔 /侧     

多巴酚丁胺和腺苷对心肌血流速度和容积的影响及其评价冠脉狭窄的意义

目的　评价多巴酚丁胺和腺苷对冠脉微循环的直接效应。方法　建立 8条一支冠脉 (左前降支或左回旋支 )轻中度狭窄的犬模型 ,直接冠脉内输注多巴酚丁胺和腺苷。采用经外周静脉微泡连续输注法 ,在谐波和递增性间断超声发射下进行心肌声学造影 (MCE) ,测定微泡速度 (MV)和心肌血流容积 (MBV )。以放射性微球测定心肌血流量 (MBF)。结果　在正常冠脉供血区中 ,虽然两种药物引起MBF明显增加 [静息时 ( 1.1± 0 .4)ml/(min·g) ;输注多巴酚丁胺和腺苷时分别为 ( 3 .7± 1.2 )ml/(min·g)和 ( 4 .7± 1.0 )ml/(min·g) ] ,而MBV仅轻微增加 (分别为 13 % ,17% ) ,但是MV增加的程度与MBF相一致 (静息时 5 .0± 0 .9;多巴酚丁胺和腺苷分别为12 .3± 4.1,13 .8± 4.1)。在狭窄冠脉供血区中 ,虽然两种药物引起了一定程度的MBF增加 (P <0 .0 5 ) ,但MBV较静息状态降低 (P <0 .0 5 ) ;然而MV明显高于静息状态 (P <0 .0 5 ) ,两种药物间比较无差异。两种药物负荷时的MV比值 (狭窄 /正常 )与MBF比值之间有良好的线性相关 (P <0 .0 0 5 ,r分别为 0 .85和 0 .68)。结论　冠脉内直接输注多巴酚丁胺和腺苷时 ,两种药物对狭窄和正常冠脉供血区微循环的影响相似。因此 ,两种药物可在冠脉狭窄的评价中交互使用。     

能量反向脉冲多普勒技术心肌造影评价急性高血糖对心肌血流的影响

目的采用能量反向脉冲多普勒技术(Power pulse inversion imaging,PPI)进行心肌声学造影超声心动图(Mvocardial Contrast Echocardiography,MCE),评价急性高血糖(Hyperglycemia,HG)对正常和缺血心肌的心肌血流量(Mvocardial Blood Flow,MBF)的影响.方法采用ATLHDI 5000超声诊断仪,P3-2MHz谐波探头(基础频率1.7MHz).静脉连续滴注氟碳类造影剂PESDA.5条开胸犬,先于基础状态及静脉推注潘生丁(DIP),引起充血状态后行MCE.待冠脉血流量和血压恢复至基础水平后,静脉推注50%葡萄糖溶液(600mg/kg)和DIP(0.56mg/kg)的混合液,造成急性高血糖和平稳的充血状态,再次MCE.最后结扎冠脉至流量为原来的10%,重复测定高血糖前后充血反应时的MBF.结果1、在正常心肌,DIP引起充血反应后PPI测定的心内膜下区(EN)和心外膜下区(EP)MBF较基础状态下MBF明显增加(EN9.18±3.09至18.45±4.84,P＜0.0001;EP7.56±5.06至1 6.78±8.59,P＜0.0008),但在充血反应的同时注射高浓度葡萄糖时EN和EP的MBF都降低(EN9.2±4.43,P＜0.0001;EP8.1 6±4.93,P=0.001).HG时EN与EP区的MFR均下降(EN2.09±0.42和1.10±0.61;EP2.69+1.50和1.57±1.4 7,P均＜0.0001).2.在缺血心肌,当在充血反应同时注射高浓度葡萄糖时,EN和EP的MBF都略升高,但差别无显著意义(P=0.43和P=0.36).HG前后缺血心肌的MFR亦无显著差异(ENP=0.33;EPP=0.18).结论急性HG会使正常心肌的MBF及MFR下降.但对缺血心肌的MBF及MFR无明显影响.     

急性心肌梗塞后心肌血流的MCE与MRI实验研究

目的　探讨心肌声学造影 (MCE)和MRI对急性心肌梗塞 (AMI)后残余心肌血流的诊断作用。方法　 7只犬开胸结扎冠状动脉左前降支制作AMI动物模型 ,行活体MCE及离体灌注MRI检查 ,伊文思蓝和TTC染色分别确定缺血和梗塞区 ,放射微球99Tcm MAA测定心肌血流量 (MBF)。通过免疫组化和体视学方法测量和计算心肌微血管体积分数和微血管平均宽度。结果　正常心肌、缺血心肌和梗塞心肌声学造影强度分别为 5 3 .2 3± 6.14、2 3 .67± 6.14和 4.3 2± 4.11。MCE的A·β值与放射微球所测MBF高度一致和相关 ,缺血和梗塞区触发间隔 声强度曲线与灌注MRI时间 信号强度曲线表现一致。缺血和梗塞区心肌微血管的宽度和体积分数较正常心肌显著减少。结论　MCE和造影剂灌注MRI可反映AMI后心肌微血管损伤程度及残余血流量     

双嘧达莫与多巴酚丁胺负荷心肌超声造影探测冠脉狭窄的对比研究

目的对比双嘧达莫和多巴酚丁胺负荷心肌超声造影(MCE)探测静息状态下无心肌血流限制性冠脉狭窄的能力.方法用放置"水膨胀”式缩窄器于冠脉主干近端的方法,建立15只慢性多支冠脉狭窄闭胸犬模型.术后7～10d进行静息、双嘧达莫和多巴酚丁胺的小剂量微泡弹丸式注射法MCE,并同步用放射性标记微球测量心肌血流(MBF).以MBF储备≥3为正常和＜3为异常供血区.结果两种药物引起MBF增加,在正常和异常供血区均相近.两种药物负荷时,MCE示异常供血区灌注缺损的范围和程度相同.两种药物作用下异常供血区的峰值声强度(VI)均较正常供血区低(P＜0.05),异常和正常供血区峰值VI比值非常接近;且双嘧达莫和多巴酚丁胺的峰值VI比值均与相应的MBF比值呈良好的线性正相关(r=0.90和0.87,P＜0.0001).结论双嘧达莫和多巴酚丁胺负荷MCE探测冠脉狭窄的能力相近.因此,两者均可用于慢性冠脉狭窄的诊断.     

白细胞在创伤后心功能不全中的作用

目的　探讨创伤后心肌组织是否存在着白细胞浸润 ,并研究白细胞在心脏功能不全中的作用。方法　麻醉后的雄性小鼠被随机分为创伤组和对照组 (2 5只 /组 ) ,在创伤后 6h测定两组小鼠平均动脉压(MAP)、心脏功能指标和心肌组织髓过氧化物酶 (MPO)活性。结果　创伤组小鼠出现了明显的低血压和心脏功能不全 [创伤组平均动脉压 (MAP)、等容收缩期室内压最大变化速率 (+dp dtmax) ,心脏指数(CI)分别为 (70± 9)mmHg ,(3492± 2 76 )mmHg/s ,(6 2± 6 )ml/min/ 10 0g ;对照组分别为 (90± 8)mmHg ,(474 5± 2 19)mmHg/s,(72± 7)ml/min/ 10 0g ,P <0 0 5 ];创伤组小鼠心肌组织MPO活性明显增高 [创伤组为 (8 4 6± 1 70 )U/ 10 0mg ,对照组为 (4 5 2± 0 94 )U/ 10 0mg,P <0 0 5 ],且MPO活性与心脏功能呈明显负相关。结论　创伤后心肌组织的炎症反应是导致创伤后心功能不全的一个重要因素 ,提示抗炎治疗对于改善创伤后心功能不全具有潜在的治疗价值     

双嘧达莫负荷超声心动图探测冠状动脉狭窄的病理生理基础

目的 探讨双嘧达莫负荷超声评价冠状动脉狭窄的病理生理基础,方法 双嘧达莫负荷超声评价慢性冠脉狭窄犬的室壁增厚率（％WT）,放射性微球定量心肌血流量（MBF）,结果 负荷状态,MBF储备＜2的心肌节段％WT减小;2小于等于MBF储备＜3的节段％WT无明显变化,而BF储备大于等于3的节段％WT反而增加,结论 狭窄冠脉MBF储备的异常程度可能是双嘧达莫负荷超声评价冠脉狭窄的主要病理生理基础。     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.     

Systematic Reviews Published in the January 2011 Issue of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly as a DVD and monthly online. The January 2011 issue (first quarterly DVD for 2011) contains 4515 complete reviews, 1985 protocols for reviews in production, and 13,521 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 641,000 randomized controlled trials, and 14,018 cited papers in the Cochrane methodology register. The health technology assessment database contains over 9300 citations. One hundred and seven new reviews have been published in the last 3 months, of which five have potential relevance for practitioners in pain and palliative medicine.     

Interprofessional approaches to creating safe,high quality health care

Three supplementary perspectives are presented arguing that interprofessional collaboration is both necessary and desirable. Nonetheless, there are often too many serious intra-professional barriers and obstacles to interprofessional collaboration to make it successful. Some of these barriers, it is argued and illustrated, are found in the multiple ways in which professional identity is tacitly acquired and embodied in the practitioners' habitual, everyday practice. The paper then explores ways in which reflection, especially Second order reflection, can help to elucidate and overcome these obstacles, as well as increasing professional adaptability and competence.     

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.     

Prise en charge des entorses externes de cheville : étude clinique préliminaire sur l’efficacité du dispositif Myolux™

Ankle sprains are the most common injury of the musculoskeletal system and are associated with significant societal and economic impacts. It has been proven that classical therapeutic strategies may not be effective in preventing recurrent injuries: the recurrence rates reported in the literature can reach 73%. In order to provide an effective rehabilitation solution, a destabilizing orthosis was developed. This device is equipped with a mechanical articulator reproducing the subtalar mechanics and placed under the heel. In this paper, we present the main results of a preliminary clinical study conducted between 2004 and 2007. All subjects included in this study were treated with the abovementioned orthosis during 10 rehabilitation sessions of 30 minutes each. Data show a relatively low recurrence rate of 12% for the overall population. Moreover, it's of primary importance to note that this satisfactory ratio is largely reduced (3% of recurrence rate) for the 29 patients who performed one training session per month after the 10th initial rehabilitation sessions. Hence, the destabilizing orthosis appears to be an effective solution to prevent recurrent ankle sprains. However, joint protection requires long-term and regular training sessions. This result has motivated the development of a similar device allowing patients to perform training sessions at home. Finally, data obtained in this study are promising awaiting the final results of the comparative, multicentric and independent clinical trials currently managed by the Hospices Civils de Lyon.     

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.