蛋白微泡声学造影剂在缺血再灌注心肌中排空现象及其机制的探讨

目的　探讨蛋白外壳含氟烷微泡声学造影剂在缺血再灌注 (I/R)心肌中的排空现象及其机制。方法　建立开胸犬I/R模型 ,再灌注前后采用氟烷微泡声学造影剂及间歇谐波技术行心肌声学造影 ,测定造影剂在心肌内的排空时间。光镜及电镜观察离体白细胞与蛋白微泡的粘附过程 ,流式细胞仪测定白细胞与微泡混合后 ,整合素对荧光强度的影响。结果　蛋白微泡声学造影剂流经I/R心肌时出现显著的延迟排空现象。蛋白微泡与佛波醇 (PMA )激活的白细胞接触后 5min大量结合到白细胞表面 ,未激活的白细胞表面少有微泡粘附 ( 2 0 .3± 2 .7对 4.5± 1.4,P <0 .0 1)。15min时微泡被吞噬入细胞内 ,并保持形态完整至 3 0min。两者的结合可被Mac 1mAb大部分阻止 ( P <0 .0 1) ,VLA 4mAb轻度阻止 ( P <0 .0 5 )。结论　蛋白微泡声学造影剂在I/R心肌延迟排空的可能机制是蛋白微泡经 β2 整合素Mac 1和VLA 4介导与I/R后激活的白细胞结合 ,并进入细胞内从而在炎症部位停留。     

miRNA－92a在缺血再灌注肾损伤中的表达变化

目的 观察miRNA-92a在缺血再灌注(I/R)损伤4h、24h后小鼠肾组织的表达变化,探讨肾脏缺血损伤后血管生成的可能机制.方法 采用双侧夹闭小鼠肾蒂的方法 制备急性缺血再灌注肾损伤模型,术后灌注24h后收集血清和肾脏标本,分别检测肾功能及观察肾组织病理学改变.实时定量逆转录聚合酶链反应(real-time RT-PCR)的方法 检测小鼠I/R损伤4h和24h组中miRNA-92a的表达水平.结果 (1)采用血清肌酐(Scr)和尿素氮(UN)评估肾功能,肾脏I/R 24h组与假手术组(sham)比较有显著性差异(P<0.05);HE染色观察肾组织病理改变明显,肾缺血再灌注模型成功.(2)而I/R4h和24h后,miRNA-92a的表达上调,其上调倍数分别为3.23±0.74,1.53±0.33 (P<0.05).结论 小鼠I/R损伤中miRNA-92a表达显著上调,miRNA-92a可能参与缺血再灌注肾组织损伤的血管再生的调控过程.     

兔心肌缺血再灌注损伤模型制备的心肌声学造影研究

目的探讨简单有效的兔心肌缺血再灌注损伤模型制备方法,并利用心肌声学造影评价兔心肌缺血再灌注损伤。方法将70只日本大耳白兔随机分为2组:35只心肌缺血/再灌注组(I/R)和35只假手术组(SH)。I/R组阻断冠状动脉左前降支90min,再灌注60、120、180min及1周;SH组开胸后同一部位只穿线不阻断。观察两组兔术前及术后各时段心肌声学造影的变化,最后行HE及MASSON染色。结果成功制备兔心肌缺血再灌注损伤模型30只,I/R组缺血90min至再灌注180min兔损伤节段造影剂视频强度超声均值对比术前及SH组均有不同程度减低,且差异有统计学意义(P0.05)。I/R组兔术后HE及MASSON染色均证实有心肌损伤病理表现,随着早期再灌注时间的延长损伤程度逐渐加重。结论通过阻断兔冠状动脉左前降支90min后解除阻断使其再灌注可成功建立心肌缺血再灌注损伤模型,心肌声学造影可以有效评价心肌缺血再灌注损伤。     

超声造影定量分析L-精氨酸改善大鼠肾缺血再灌注损伤的应用价值

目的应用超声造影技术定量分析L-精氨酸对大鼠肾缺血再灌注损伤肾皮质血流灌注的影响,探讨超声造影技术在评价药物干预肾缺血再灌注损伤疗效中的应用价值。方法健康雄性大鼠24只随机分成假手术组(Sham组)、缺血再灌损伤组(I/R组)和L-精氨酸组(L-arg组),每组8只。行超声造影检查观察肾皮质血流灌注情况并脱机分析时间-强度曲线(TIC)。实验结束后,行肾组织病理学检查。结果与假手术组比较,I/R组和L-arg组肾脏病理改变明显,达峰时间(TTP)和平均通过时间(MTT)延长,曲线下面积(AUC)显著增加(P0.05);与I/R组比较,L-arg组病理改变显著,峰值浓度(Peak)增高,TTP、MTT缩短,AUC减少(P0.05)。结论超声造影结合时间-强度曲线能定量分析L-精氨酸对大鼠肾缺血再灌注损伤肾皮质血流灌注的改善。     

携带抗P-选择素单抗靶向微泡和对比超声评价肾缺血再灌注损伤

目的探讨携带抗小鼠P-选择素单抗的靶向超声微泡（MBp）和对比超声（CEU）评价肾缺血再灌注损伤的可行性。方法12只实验小鼠随机均分为2组：缺血再灌注（IR组）和假手术组（SH组）,应用＂亲和素-生物素＂桥连法构建MBp。所有小鼠分别随机（间隔30min）经静脉弹丸注射给予普通脂质微泡（MB）和MBp,10min后行肾CEU检查,测量肾显影的声强度（VI）,最后进行肾组织免疫组化检测。结果第一帧CEU图像显示MBp及MB在IR组缺血再灌注肾分别可见显著及轻度的超声显影,而两者在SH组假手术肾均无明显的超声显影。VI值在IR组MBp较IR组MB及SH组MBp均明显增大（P〈0.05）;而在IR组MB较SH组MB轻度增大（P〈0.05）。免疫组化检测显示缺血再灌注肾血管内皮P-选择素表达较假手术肾明显增加。结论应用MBp行CEU检查可有效评价小鼠肾缺血再灌注损伤,将可用于评价微血管炎症或相关的血管内皮反应。     

超声组织定征视频法监控兔缺血再灌注肾靶向声学造影实验研究

目的定量评价自制靶向超声造影剂对兔缺血再灌注肾显像的靶向增强效果。方法将磷脂酰丝氨酸(phos-phatidylserine,PS)加在自制表面活性剂类超声造影剂微泡壁上,用有和无PS造影剂分别对6只肾缺血再灌注损伤兔进行声学造影,谐波显像观察肾实质回声的变化,用国产“DFY-2型超声图像定量分析诊断仪”对兔肾实质灰阶(GS)值进行动态定量分析。结果造影后,有和无PS组GS峰值分别高于造影前(P<0.001和P<0.05);有PS组GS峰值高于无PS组(P<0.001)。结论超声组织定征视频法可定量评价兔缺血再灌注肾靶向声学造影的增强效果。     

超声分子成像对小鼠肾脏急性微血管炎症的可视性评价

目的 应用超声分子成像技术可视性评价小鼠肾脏急性微血管炎症.方法 缺血再灌注处理制备小鼠肾急性微血管炎症模型 (IR组,6只)及肾假手术处理模型(SH组,6只),所有实验小鼠均经静脉随机(间隔30 min)弹丸注射携带抗小鼠P-选择素单抗靶向超声微泡(MBp)、同型对照抗体超声微泡(MBc)及普通脂质超声微泡(MB),10 min后行肾对比超声(CEU)检查,测量肾脏显影的声强度(VI).并采用平行板流动腔技术在微血管生理血流条件下体外评价MBp的靶向黏附效能.结果 在缺血再灌注肾,MBp呈显著的超声显影,而MBc和MB呈轻度的超声显影;3种超声微泡在假手术肾均无明显的超声显影.MBp的VI值在缺血再灌注肾较假手术肾明显增大(P<0.05),同时较MBc和MB在缺血再灌注肾的VI值也都明显增大(P<0.05);而MBc及MB在缺血再灌注肾的VI值较各自假手术肾轻度增大(P<0.05).在微血管生理血流剪切应力环境下MBp可与小鼠P-选择素Fc段(PSFc)实现有效的靶向性特异结合.结论 超声分子成像技术可对肾脏急性微血管炎症进行有效的可视性评价,该技术将可用于可视性评价微血管炎症或相关的血管内皮反应.MBp在微血管生理血流条件下具有良好的靶向黏附效能.     

依达拉奉预处理对大鼠脑缺血再灌注后血管内皮功能的影响

目的:观察依达拉奉用于大鼠脑缺血预处理对血管内皮的影响。方法:健康成年雄性SD大鼠36只随机平均分入假手术组(N/A组)、缺血再灌注损伤组(I/R组)和依达拉奉预处理组(EP组),采用线栓法制备大鼠大脑中动脉闭塞再通模型,EP组在建立模型前30min给予依达拉奉3mg/kg,N/A组和I/R组则给予生理盐水2mg/kg。分别于缺血前(T0)、缺血30min(T1)、缺血1h(T2)、缺血2h(T3)、再灌注30min(T4)、再灌注1h(T5)、再灌注6h(T6)及再灌注12h(T7)采血检测丙二醛(MDA)、一氧化氮(NO)、血浆可溶性血栓调节蛋白(sTM)浓度及血管性血友病因子(vWF)含量,T0和T7时点测循环内皮细胞(CEC)计数。结果:I/R组与EP组缺血后各检测指标均高于N/A组(P<0.05),与I/R组相比,EP组缺血后各时点MDA、NO、sTM浓度及vWF含量均显著降低(P<0.05),T7时点的CEC计数亦显著低于I/R组(P<0.05)。结论:依达拉奉预处理通过降低氧自由基水平能减轻大鼠脑缺血再灌注对血管内皮细胞的损伤,有明显的血管内皮保护作用。     

大鼠实验性肠缺血再灌注损伤过程中组织因子表达的研究

目的 :研究大鼠肠缺血再灌注损伤过程中组织因子(tissue factor,TF)和相关调控分子及凝血系统的变化。方法:将40只雄性Wistar大鼠随机等分为假手术(Sham)组和肠缺血再灌注损伤(ischemia reperfusion injury,I/R)组。夹闭I/R组大鼠的肠系膜上动脉60 min后恢复血供,再灌注15 min;Sham组大鼠只开腹暴露肠系膜上动脉,不予夹闭,持续75 min。分别于缺血前、缺血60 min和再灌注15 min取血液标本,于再灌注结束后取缺血再灌注区的肠黏膜组织进行检测。结果:I/R组大鼠肠缺血60 min和再灌注15 min时,血液中TF、凝血酶-抗凝血酶复合物(thrombin-antithrombin complex,TAT)和丙二醛(malonal dehyde,MDA)含量分别为(33.45±6.12)ng/L和(46.12±8.16)ng/L、(9.64±2.19)μg/L和(20.11±6.29)μg/L、(23.65±4.25)μmol/L和(37.69±6.43)μmol/L,均明显高于Sham组(P均<0.01)。结论:大鼠肠缺血再灌注损伤以及由此诱发的过氧化损伤引起TF合成与释放增多,进而激活凝血系统,导致TAT水平增高。NF-κB和EGR-1作为TF的2个重要调控因子在大鼠肠缺血再灌注损伤过程中上调了TF的基因转录和表达。     

miRNA－92a在缺血再灌注肾损伤中的表达变化

目的观察miRNA-92a在缺血再灌注（I／R）损伤4h、24h后小鼠肾组织的表达变化,探讨肾脏缺血损伤后血管生成的可能机制。方法采用双侧夹闭小鼠肾蒂的方法制备急性缺血再灌注肾损伤模型,术后灌注24h后收集血清和。肾脏标本,分别检测肾功能及观察肾组织病理学改变。实时定量逆转录聚合酶链反应（real—time RT-PCR）的方法检测小鼠I／R损伤4h和24h组中miRNA-92a的表达水平。结果（1）采用血清肌酐（Scr）和尿素氮（UN）评估肾功能,肾脏I／R 24h组与假手术组（sham）比较有显著性差异（P〈0．05）;HE染色观察肾组织病理改变明显,肾缺血再灌注模型成功。（2）而I／R4h和24h后,miRNA-92a的表达上调,其上调倍数分别为3．23±0．74．1．53±0．33（P〈0．05）。结论小鼠I／R损伤中miRNA-92a表达显著上调,miRNA-92a可能参与缺血再灌注肾组织损伤的血管再生的调控过程。     

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.     

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.     

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.     

护理干预对面部中重度寻常型痤疮的临床疗效影响分析

目的研究护理干预对面部中重度寻常型痤疮的临床疗效影响。方法选取本院在2014年4月~2016年7月诊治的136例面部中重度寻常型痤疮患者,随机分为研究组与对照组,每组68例;所有患者均依据其情况给予对应的治疗,其中对照组在治疗期间给予常规护理,研究组在对照组的基础上再给予综合性护理干预,比较两组的治疗效果及护理满意度情况等。结果患者在接受治疗和护理后,研究组中度与重度患者的治疗效果较对照组均明显提高(P0.05),研究组护理满意度较对照组明显增高(P0.05)。结论对面部中重度寻常型痤疮患者在其治疗期间给予综合性护理干预,具有良好的效果。