单侧大脑中动脉供血区脑缺血后同侧黑质MRI特征性表现的实验研究

目的分析线栓法制作单侧大脑中动脉供血区脑缺血后同侧黑质的MR信号变化特点,评价MR显示脑缺血后远隔部位损害的价值。方法清洁级健康雄性SD大鼠(270~320g)20只,按照随机分组原则分成三组:永久性脑缺血组(MCAO)8只,脑缺血1.5h再灌注组(MCAO/R)8只,假手术对照组4只。应用线栓法制作脑缺血及再灌注模型。模型制作成功后1天、3天、7天、14天行俯卧位磁共振扫描。主要序列包括T2WI、DWI、T2map,观察脑缺血范围,计算并测量两侧黑质ADC和T2值的动态改变。结果假手术对照组各时间点磁共振图像上双侧纹状体、皮层及黑质等脑组织各部均未出现异常表现。MCAO组1天时8只大鼠MR扫描显示脑缺血范围累及左侧纹状体和左侧颞顶脑皮层,MCAO/R组5只显示上述区域异常信号,3只仅表现为左侧纹状体区信号异常。1天时两组动物双侧黑质各序列均未见异常表现。3天时MCAO和MCAO/R组所有动物均显示脑缺血同侧的黑质T2高信号,境界清楚,DWI显示为高信号,相应区域ADC减低,T2map为高信号,T2值增高。对侧黑质信号无明显变化,两侧黑质ADC和T2值差异有显著意义。7天和14天时MCAO和MCAO/R组左侧黑质异常信号消失。结论大鼠一侧纹状体缺血后3天同侧黑质出现MR异常信号,MR能够反映脑缺血后远隔部位的继发性改变。     

大鼠局灶性脑缺血后皮质水肿的7.0Tesla磁共振T2加权成像及波谱分析

目的:采用7.0 Tesla磁共振(MR(l)) T2加权成像(T2WI)结合磁共振波谱分析(MRS)研究大鼠脑缺血后脑皮质水肿情况.方法:SD大鼠40只随机分为假手术组和大脑中动脉缺血(MCAO)1 d、3d及7d组,分别于脑缺血后1、3、7d,采用7.0 Tesla MRI扫描各组大鼠脑部T2 WI序列,检测缺血侧...     

超急性脑卒中血脑屏障和相关脑代谢物变化的研究

目的利用高场强MRI序列描绘早期脑卒中血脑屏障（BBB）损伤随时间变化的影像学特征,并结合频谱中脑代谢物的变化情况,为早期溶栓治疗提供直观和个体化的影像学指导信息。材料与方法健康SD大鼠20只,采用栓线法制备大鼠大脑中动脉闭塞（MCAO）模型,在Angilent 7.0 T动物MR扫描仪上行常规扫描（T1WI、T2WI、DWI）,静脉注射MRI对比剂Gd-DTPA后行T1WI增强扫描,并利用MR频谱（1H MRS）技术测量超早期各时间段内病灶区的脑代谢物浓度变化,并用LCModel软件定量出病变区特定代谢物的绝对浓度。结果各组MCAO大鼠,大脑中动脉闭塞10 min后,DWI均能在大脑中动脉供血相应纹状体区及顶叶皮层区显示出异常的高信号,其中1.5 h组MCAO大鼠,大脑中动脉闭塞1.5 h再灌注30 min后,增强T1WI扫描出现脑室系统（第三脑室,侧脑室等）明显高信号改变;而2.0 h组MCAO大鼠再灌注30 min后局部脑实质内可出现明显T1高信号改变。未灌注组MCAO大鼠频谱发现,大脑中动脉闭塞1 h（频谱第一时间段）病变缺血区较对侧正常区Lac峰明显增高,NAA峰明显下降;谷氨酸和牛磺酸的绝对浓度于2 h内逐渐上升至峰值后,3 h段开始明显下降。结论利用MRI对比剂Gd-DTPA的T1WI成像方法可描绘出急性缺血性脑卒中BBB损伤随时间的变化,并采用MR频谱技术正确量化同时期相关脑代谢物的变化。总之,这些相关评估将对溶栓治疗提供客观和个体化的影像学信息。     

大鼠急性脑缺血扩散张量成像各参数变化的实验研究

目的明确急性脑缺血扩散张量成像DCav、Iso image、FA、RA值的动态变化。方法清洁级健康雄性SD大鼠12只，分成四组：A组MCAO脑缺血1h（3只），B组脑缺血1．5h（3只），C组脑缺血3h（3只），D组脑缺血6h（3只）。按照时间点行脑MR检查，测量病变和对侧相应区域Isoimage信号、DCav、FA、RA值。结果脑缺血各观察时间点MRI显示患侧脑皮质和纹状体等皮质下结构DCav值降低至对侧的51％～67％，各向同性图像Iso显示明确的病侧异常高信号。在MCAO1h和1．5h虽然患侧FA、RA测量值偏高，但与对侧不具备统计学差异。脑缺血3h时患侧FA、RA值降低，与对侧差别有显著意义，此种现象持续至6h。结论急性脑缺血不同MRDTI参数随时间变化各异，联合应用能全面反映缺血组织病理生理状态。     

评估量化超急性期缺血性脑卒中发病时间窗的研究

目的利用高场MR多模态成像序列评估及找出脑卒中的早期迹象影像证据,为早期rt-PA溶栓治疗时间窗提供直观和个体化的影像学信息。材料与方法利用线栓法栓塞右侧大脑中动脉,制备MCAO大鼠模型10只,在不同的时间点采用DWI、病灶的表观扩散系数（ADC）和常规T2WI评估MCAO大鼠模型脑缺血性病变区域的特性。通过MRS、并应用LCModel后处理来绝对定量在不同的时间点病灶内局部特异性代谢物浓度的变化。结果10只MCAO大鼠,6 h内T2WI均未显示明确病变灶;而大脑中动脉梗塞10 min后,DWI均能在大脑中动脉供血相应纹状体区及顶叶皮层区显示出异常的高信号,与DWI相应病变区ADC图均显示有异常的低信号。MRS研究发现,大脑中动脉梗塞1 h后病变中心区对比相应对侧正常区Lac峰明显增高,NAA峰明显下降;谷氨酸和牛磺酸绝对浓度2 h内逐渐上升达峰值,随后3 h段明显下降。结论 MR多模态成像序列,特别是利用T2WI、DWI及1H MRS可定性诊断超早期缺血性脑卒中,并能评估及量化超急性脑卒中发病时间窗,为筛选适合rt-PA溶栓治疗者提供客观和个体化的影像学信息。     

脑缺血再灌注损伤后神经细胞巢蛋白和干细胞因子基因表达

目的研究大鼠脑缺血再灌注损伤后神经细胞巢蛋白(nestin)和干细胞因子(SCF)基因表达的变化。方法成年健康雌性SD大鼠36只，以线栓法建立大脑中动脉缺血再灌注模型，随机分为缺血1．5h再灌注2h、6h、12h、24h、2d、3d、7d、14d组和假手术组，每组4只。应用原位杂交技术检测脑缺血再灌注后脑组织nestin和SCF mRNA的表达。结果假手术组皮质、纹状体和室旁区nestin mRNA表达很弱。缺血再灌注后nestin mRNA表达，皮质除2h以外、纹状体除2h、6h以外、室旁区除2h、6h、14d以外各时间点均明显高于假手术组。假手术组皮质、纹状体和室旁区SCF表达很弱。缺血再灌注后SCF mRNA表达，皮质除2h、6h、12h以外、纹状体除2h、6h以外、室旁区除2h、14d以外各时间点均明显高于假手术组。结论脑缺血再灌注后SCF mRNA表达可能具有促进神经干细胞增殖作用。     

脑缺血-再灌注诱导大鼠皮层和纹状体组织信号转导与转录激活子-3的激活变化

目的研究局灶脑缺血诱导大鼠皮层和纹状体信号转导与转录激活子-3（STAT3）的激活变化。方法采用SD雄性大鼠线栓法制作右大脑中动脉缺血（MCAO）局灶脑缺血模型。运用抗STAT3和抗磷酸化STAT3抗体做免疫印迹（IB）检测皮层和纹状体STAT3的表达及激活变化。结果缺血-再灌注不同时间并不能引起皮层及纹状体STAT3蛋白表达变化．但可诱导其磷酸化水平显著增加。缺血-再灌注24h达到峰值，与假手术组相比分别增加约5．5倍和8．4倍。结论局灶脑缺血-再灌注能引起缺血同侧皮层和纹状体STAT3磷酸化水平的显著增加，提示缺血性脑损伤诱导STAT3的激活可能参与缺血皮层区和纹状体神经元细胞的病理生理过程。     

构建大脑中动脉阻塞脑缺血模型大鼠的类型分析

背景：线栓法造成短暂性大脑中动脉阻塞是研究大鼠局灶性脑缺血普遍使用的模型制作方法。但制作大鼠脑缺血模型的类型存在一定差异,可能导致实验结果的偏差。目的：分析大脑中动脉阻塞线栓法制作大鼠脑缺血模型的类型及其影响因素。方法：雄性SD大鼠166只,参照Longa线栓法造模,术后24h行MRI扫描,根据扫描结果将大鼠分成皮质梗死组、皮质下梗死组及无梗死组,分析造模时线栓插入的深度。结果与结论：皮质梗死组、皮质下梗死组和无梗死组大鼠的线栓插入深度分别为（19.9±0.9）,（19.0±1.1）和（17.7±1.3）mm,皮质梗死组大鼠的线栓插入最深,而无梗死组的线栓插入最浅（P〈0.01）。提示插入深度不同导致的大鼠脑梗死的类型也不同,线栓插入越深,皮质梗死的概率可能越大。     

脑缺血后神经细胞黏附分子和生长相关蛋白-43的表达与神经功能恢复的关系

目的 观察大鼠局灶性脑缺血再灌注后神经细胞黏附分子-43（NCAM）和生长相关蛋白（GAP-43）基因表达在神经功能恢复过程中的作用。方法 应用线栓法建立大鼠大脑中动脉阻塞（MCAO）再灌注模型。采用Bederson神经功能评分法评价脑缺血90min再灌注2h、12h、1d、2d、3d、7d和14d等时间点大鼠神经功能情况，采用原位杂交技术检测NCAM mRNA和GAP-43 mRNA的表达。结果 大鼠脑缺血再灌注后，神经功能评分于再灌注2d开始降低，神经功能逐渐恢复。在皮质区和纹状体区，脑缺血侧GAP-43 mRNA表达于再灌注12h和2d出现峰值，以后逐渐降低，至14d恢复至假手术组水平。皮质区NCAM mRNA的表达于再灌注2h后开始增强，12h后达高峰；纹状体区NCAM mRNA的表达于再灌注后2h时开始增强，1d后达高峰，以后逐渐减少，14d降至基础水平。结论 脑缺血再灌注后，NCAM的表达可能参与了脑细胞的修复过程，GAP-43 mRNA的表达增强可能与损伤神经的功能恢复有关。     

脑缺血-再灌注诱导大鼠皮层和纹状体组织信号转导与转录激活子-3的激活变化

目的研究局灶脑缺血诱导大鼠皮层和纹状体信号转导与转录激活子-3(STAT3)的激活变化。方法采用SD雄性大鼠线栓法制作右大脑中动脉缺血(MCAO)局灶脑缺血模型。运用抗STAT3和抗磷酸化STAT3抗体做免疫印迹(IB)检测皮层和纹状体STAT3的表达及激活变化。结果缺血-再灌注不同时间并不能引起皮层及纹状体STAT3蛋白表达变化,但可诱导其磷酸化水平显著增加。缺血-再灌注24h达到峰值,与假手术组相比分别增加约5.5倍和8.4倍。结论局灶脑缺血-再灌注能引起缺血同侧皮层和纹状体STAT3磷酸化水平的显著增加,提示缺血性脑损伤诱导STAT3的激活可能参与缺血皮层区和纹状体神经元细胞的病理生理过程。     

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.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.     

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.     

Wie zuverlässig sind Angaben zu nichtentzündlichen ausgedehnten Schmerzen?

ZusammenfassungFragestellung Es wurde geprüft, wie sich der Differenziertheitsgrad zweier Schmerzmessmethoden auf Angaben zur Ausgedehntheit klinischer Schmerzen auswirkt. Zugleich wurde der Referenzzeitraum variiert, über den die Patienten berichten sollten.Methode Erfasst wurde der Einfluss zu Lasten der Befragungsdifferenziertheit durch den Vergleich zweier Körperschema-Bildvorlagen. Drei Referenzzeiträume (Schmerz aktuell, letzte Woche, letztes halbes Jahr) wurden vorgegeben.Ergebnisse Patienten mit ausgedehnten Schmerzen gaben bei differenzierter Befragung um so mehr Schmerzen an, je weiter die Schmerzen zurück lagen und je größer der Berichtszeitraum war. Patienten mit gelenknahen Schmerzen gaben bei hoch differenzierter Befragung weniger ausgedehnte Schmerzen in der Vergangenheit an als bei globaler Einschätzung. Patienten mit Rückenschmerzen berichteten bei differenzierter Befragung zum aktuellen Schmerz über weniger ausgedehnte Schmerzen als bei globaler Befragung.Schlussfolgerung Die Angaben zur Schmerzausdehnung variieren vor allem bei Patienten mit ausgedehnten Schmerzen in Abhängigkeit von der Differenziertheit der Befragung. In diesen Fällen ist die Wahrscheinlichkeit erhöht, dass sich die Beschwerdesymptomatik zumindest teilweise erst in der Reaktion auf die situativen Befragungsbedingungen konstituiert und daher nicht auf andere Befragungsbedingungen generalisiert werden kann.