3.0T MRI观察兔腹主动脉粥样硬化斑块演变过程

目的 探讨MRI在识别兔动脉粥样硬化斑块中的诊断价值.方法 20只新西兰白兔,随机设置实验组16只,对照组4只,结合球囊拉伤腹主动脉和间断高脂饲料喂养,建立动脉粥样硬化模型;在建模后2、3、4个月分别行高分辨MR成像.通过测量腹主动脉管壁厚度和面积、管腔面积、管壁信号增强程度等指标,观察腹主动脉壁的重构过程,并对模型最终的斑块成分进行MRI和组织病理结果对照研究.结果 对17只兔(实验组14只,对照组3只)完成3次MR检查,并获得组织病理学结果.MRI显示,实验组腹主动脉管壁厚度和面积逐渐增厚,且与同期对照组相比差异均有统计学意义(P＜0.01);实验组腹主动脉管腔进行性扩张,管壁强化程度较对照组增加明显,但演变过程不明显.另外,MRI对兔腹主动脉硬化斑块的成分判别限制在纤维、脂质和钙化斑块,对纤维斑块、脂质斑块识别率较高.结论 高分辨MRI可以无创性地观察动脉粥样硬化动物模型腹主动脉管壁重构的演变过程,有助于对动脉硬化斑块的预后和药物干预进行探索.     

亲血栓性靶向超声造影剂增强兔腹主动脉新鲜血栓显像的实验研究

目的探讨亲血栓性白蛋白靶向超声造影剂体内增强兔腹主动脉新鲜血栓显像的效果.方法采用三氯化铁(FeCl3)溶液诱发20只健康新西兰大白兔腹主动脉非梗阻性新鲜血栓形成;经耳缘静脉团注0.04 ml/kg的白蛋白靶向超声造影剂进行声学造影;采用目测观察和视频灰阶分析技术,评价血栓显像的增强效果.结果造影后目测观察,亲血栓性白蛋白靶向超声造影剂对腹主动脉新鲜血栓增强显影达10 min以上,灰阶值为(98.463±6.3)dB,与造影前0 s[灰阶值(18.741±2.86) dB]比较相差非常显著(P＜0.001);普通白蛋白造影剂造影后血栓超声显像效果改善不明显,但灰阶值升高,为(28.862±2.15)dB,与造影前0 s比较相差显著(P＜0.05),与靶向造影剂造影后灰阶值比较相差非常显著(P＜0.001).结论亲血栓性白蛋白靶向超声造影剂可显著增强兔腹主动脉内新鲜血栓超声显像效果.     

超声造影定量分析评价兔粥样斑块内新生血管与病理的对照研究

目的 比较超声造影定量计算动脉粥样硬化动物模型斑块的增强强度与免疫组化微血管染色的结果,评价超声造影定量分析斑块内血管新生的可靠性.方法 高脂喂养建立动脉粥样硬化模型成功的实验兔9只,实时谐波超声造影观察兔腹主动脉超声造影增强,随后用QLab定量分析软件分别计算动脉斑块内增强强度(EI)及斑块内增强强度与腹主动脉管腔内增强强度的比值(ratio).免疫组织化学方法显示斑块内血管内皮细胞中的第Ⅷ因子相关抗原F8染色斑块内的微血管,比较超声造影定量分析与免疫组化微血管染色结果的相关性.结果 9只兔超声造影定量分析EI及ratio值分别为(3.91±0.87)dB及0.30±0.06,免疫组化染色显示9只兔腹主动脉标本中F8染色阳性5例,阴性4例.超声造影定量分析EI与F8染色有相关性(r =0.779,P=0.013),ratio值与F8染色有相关性(r =0.693,P=0.019).结论 超声造影定量分析的强度参数EI及ratio能够在一定程度上反映斑块内新生血管增生的程度,有助于对斑块稳定性的评价.     

超微超顺磁性氧化铁对兔动脉粥样硬化斑块的MRI研究

目的:利用超微超顺磁性氧化铁(USPIO)对兔动脉粥样硬化斑块进行磁共振成像,分析其磁共振表现特点及其价值.方法:实验组以球囊导管损伤腹主动脉内膜+高脂饮食的方法建立兔动脉粥样硬化模型12只,对照组3只行假手术和普通饲料喂饲.12周后对所有动物行USPIO增强前后的腹主动脉磁共振扫描,连续跟踪扫描6d(每隔24h 1次),在T2WI序列上观察血管壁信号变化情况,比较管壁信号噪声比(SNR),并将磁共振结果与病理学相对照.结果:USPIO增强后显示实验组在T2WI序列上腹主动脉管壁信号逐渐降低,在第4天SNR值达到最低点,较增强前信号差异有统计学意义(P＜0.05),而对照组腹主动脉在增强前后管壁信号无变化.病理证实所有动物模型兔腹主动脉都发生动脉粥样硬化病变,注射USPIO后处死的实验组兔普鲁士蓝染色为阳性,电镜显示USPIO颗粒存在于巨噬细胞胞浆的细胞器内.对照组兔腹主动脉病理检查为阴性.结论:USPIO颗粒可以被兔动脉粥样硬化斑块中的巨噬细胞特异性吞噬并引起相应的磁共振信号改变,USPIO磁共振成像有望在体观测动脉粥样硬化斑块内的炎症反应.     

磁共振成像检测实验性动脉粥样硬化斑块及血栓

目的 探讨MRI对兔主动脉动脉粥样硬化不同成分的斑块以及斑块破裂后血栓形成的识别能力。方法 20只雄性新西兰白兔,高脂饲料饲喂2周后采用球囊拉伤腹主动脉,继续间断高脂饲养16周后进行药物诱发试验,试验前、后分别行主动脉MR成像,最后处死动物获得主动脉的大体病理和组织学资料。将MRI所见与组织病理学结果进行对比。结果 模型建立过程中实验兔存活11只,其中7只(63.64%)成功诱发斑块破裂和血栓形成,MRI显示主动脉呈不同程度的粥样硬化改变。MRI对纤维斑块与脂质斑块的敏感度(分别为73.47%、84.62%)及与病理检查的一致性(K值分别为0.75、0.87)较高;而对于钙化改变的敏感性较低,钙化改变的敏感度为65.71%,K值为0.71。MRI对血栓数量的敏感度为71.42%;MRI测量的血栓位置(r=0.916,P<0.001)和血栓长度(r=0.883,P=0.001)均与病理测量值呈正相关。结论 MRI检测动脉粥样硬化斑块和血栓的敏感度较高,并可分辨斑块的成分。     

动脉血栓靶向超声显像的体内实验研究

目的探讨白蛋白血栓靶向超声造影剂体内增强动脉血栓超声显像的效果.方法采用FeCl3溶液诱发30只健康新西兰大白兔腹主动脉非梗阻性新鲜血栓形成;经耳缘静脉团注0.04 ml/kg的白蛋白超声造影剂进行超声造影,分为靶向组(20只)和非靶向组(10只);采用视觉观察评价血栓显像增强效果.结果 29只(29/30)兔模型建立成功;造影后视觉观察,靶向组18例达到2级增强效果,1例为1级增强效果,1例死亡;非靶向组仅2例达到1级增强效果,两组比较差异显著(P<0.01).结论白蛋白血栓靶向超声造影剂可显著增强兔腹主动脉内新鲜血栓超声显像效果.     

腹主动脉球囊扩张过程中白细胞介素8水平表达对血管内皮功能的影响

背景:炎性反应及内皮损伤在动脉粥样硬化疾病的发生、发展及冠状动脉介入治疗后再狭窄的过程中起重要作用,但炎性因子白细胞介素8具体作用机制尚未明确.目的:观察兔腹主动脉球囊扩张过程中自细胞介素8水平表达对血管内皮功能的影响.设计、时间及地点:随机对照动物实验,于2008-01/2009-03在河北省人民医院心脏中心导管室及临床研究中心完成.材料:新西兰大白兔24只,体质量2.5～3.5 kg,雌雄不拘,用于制备球囊扩张损伤模型.方法:24只大白兔按抽签法随机分为实验组和对照组,每组12只.实验组穿刺股动脉后留置鞘管,经鞘管送入球囊行球囊扩张,拉伤腹主动脉.对照组仅穿刺留鞘,不进行球囊拉伤.主要观察指标:分别于术前、术后4 h,1 d,3 d,7 d,14 d取耳缘静脉血,采用酶联免疫吸附双抗夹心法测定白细胞介素8、血管性假性血友病因子,放射免疫法测定内皮素1,利用硝酸还原酶法测定一氧化氮水平,2周后复查造影及苏木精-伊红染色观察腹主动脉管腔、管壁变化情况.结果:①兔腹主动脉球囊损伤后炎性因子自细胞介素8水平4 h后即开始明显升高,24 h后血管性假性血友病因子、内皮素1水平明显升高,一氧化氮水平明显降低,与术前及对照组相比,差异具有显著性意义(P＜0.01).②相关分析显示,白细胞介素8水平表达与血管性假性血友病因子、内皮素1水平呈正相关,相关系数r=0.532,0.619(P＜0.05),白细胞介素8水平表达与一氧化氮水平呈负相关,相关系数r=-0.517(P＜0.05).⑨球囊扩张拉伤后2周,实验组动物腹主动脉拉伤处与对照组相比管腔明显狭窄.④苏木精-伊红染色可见对照组动脉内膜光滑,内皮下有少量结缔组织,无平滑肌细胞存在,中膜平滑肌细胞呈梭形,环绕管腔排列.实验组动脉内膜、中膜增厚,管腔明显狭窄,内膜下平滑肌细胞增生,而且排列不规则,弹性纤维层结构不清,斑块隆起明显,内含泡沫细胞.结论:球囊扩张后引起炎性反应增强,激发加重了内皮功能损伤,引起腹主动脉管腔狭窄.在此过程中,自细胞介素8可能起到关键的调节作用.     

超声结合病理评估多种制备兔腹主动脉粥样硬化斑块模型方法

目的采用多种方法制备兔腹主动脉粥样硬化斑块模型,寻求可靠的动脉粥样硬化斑块模型制备方法。方法采用单纯高脂喂养(对照组)、高脂喂养+腹主动脉球囊拉伤术(实验组1)、高脂喂养+注射小牛血清白蛋白(实验组2)、高脂喂养+腹主动脉球囊拉伤术+注射小牛血清白蛋白(实验组3)4种方法建立兔腹主动脉粥样斑块模型,对比评估斑块形成情况。结果实验组腹主动脉内中膜复合体厚度(IMT)均明显高于对照组,实验组与对照组兔腹主动脉粥样斑块回声类型的占比均有显著性差异,实验组粥样斑块形成数目明显多于对照组,其中实验组3的斑块数量较实验组1、实验组2多。结论高脂喂养+腹主动脉球囊拉伤术+注射小牛血清白蛋白是一种稳定、高效的兔腹主动脉粥样硬化斑块模型建立方法,其建模效果优于其他3种方法,是一种稳定、高效的建立斑块模型方法。     

兔动脉粥样硬化斑块巨噬细胞表达动态变化

目的:检测巨噬细胞在兔动脉粥样硬化模型斑块中表达的动态变化。方法:24只健康雄性新西兰大耳白兔随机分为试验组(15只)和对照组(9只),试验组在球囊损伤腹主动脉内膜后喂养高脂饮食,对照组喂养普通饲料,于6,12,18周分别处死动物,分离腹主动脉,检测脂质和脂蛋白,应用光学显微镜观察动脉粥样硬化进程,采用免疫组织化学方法分析巨噬细胞在斑块处的表达及定位。结果:高脂饮食喂养后6周,兔动脉内皮受损,12周和18周可见明显动脉粥样硬化斑块形成。与对照组比较,巨噬细胞在动脉粥样硬化斑块处表达增高,主要位于内膜斑块的中下部分;巨噬细胞表达量随着动脉粥样硬化斑块的进展而增多。结论:巨噬细胞的表达随着斑块进展而增多,可能与动脉粥样硬化进展及斑块不稳定相关。     

辛伐他汀对兔动脉粥样硬化斑块结构及巨噬细胞移动抑制因子的影响

目的:通过研究辛伐他汀干预治疗兔动脉粥样硬化过程中,斑块组成结构及兔血清中巨噬细胞移动抑制因子(MIF)水平及其二者的相关性,探讨MIF在动脉粥样硬化过程中的意义及辛伐他汀的作用.方法:研究对象为新西兰大白兔,随机分为正常对照组,腹主动脉球囊拉伤、高脂饲养构建的兔动脉粥样硬化模型组,辛伐他汀干预动脉粥样硬化治疗组;观测各组实验对象腹主动脉斑块纤维帽厚度,并获得纤维帽的厚度与脂核横截面厚度的比值;采用ELISA法检测其血清巨噬细胞移动抑制因子水平.结果:动脉粥样硬化模型组斑块纤维帽较薄,脂核相对较大,他汀干预治疗组斑块纤维帽厚度明显高于动脉粥样硬化模型组,而脂核厚度则相对较小;动脉粥样硬化模型组MIF水平较对照组升高,干预治疗组MIF水平较模型组低,其差异有统计学意义(P＜0.05).结论:辛伐他汀干预可以改变斑块的组成结构,降低MIF水平,使动脉粥样硬化斑块更加趋于稳定.     

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.     

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.     

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.     

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.     

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.