自体骨髓单核细胞移植治疗急性心肌梗死实验研究

目的探讨自体骨髓单核细胞(ABM-MNCs)移植至心肌梗死区及周边区后的存活、分化状况,以及对心功能的影响。方法将40只日本大耳雄兔随机分为细胞移植组和对照组各20只。采用结扎左冠状动脉前降支的方法建立急性心肌梗死(AMI)模型。细胞移植组于梗死后第6天于自体髂骨处抽取骨髓,分离得到单核细胞后,以Brdu标记,经心外膜注射到梗死区及周边区。对照组仅注射等量的生理盐水。移植6周后,进行组织学及免疫组织化学检查。结果移植后6周,两组动物的心功能均有改善,但两组间有显著性差异。Brdu标记示移植组梗死区内存在阳性染色的移植细胞,而周边区可见Brdu染色阳性的心肌细胞及血管内皮细胞。免疫荧光染色示梗死区内Brdu染色阳性的移植细胞抗心肌特异性肌动蛋白抗体阴性,而周边区内Brdu染色阳性的移植细胞抗心肌特异性肌动蛋白抗体阳性。对照组未发现Brdu染色阳性的细胞。移植组梗死周边区及远离梗死区的毛血管密度均高于对照组(P<0.05),但梗死区内的毛细血管密度两组间无显著性差异(P>0.05)。结论ABM-MNCs移植至急性梗死心肌后,可在梗死区内及周边区存活,并可在周边区分化为具有心肌功能的细胞及血管内皮细胞,增加梗死周边区的血管密度,改善心功能。     

内皮祖细胞移植对犬心肌梗死后血管新生、心肌修复及心功能的影响

目的:本实验采用犬外周血血管内皮祖细胞(EPCs)体外扩增后,经皮穿刺行心肌梗死犬心外膜下移植,观察其对急性心肌梗死后心肌再生及心功能改变的影响。方法:犬自体EPCs体外扩增后,在超声引导下,经皮穿刺行心肌梗死犬心外膜下局部注射移植入心肌梗死区域,1、2、4、8周后取心肌标本,应用超声心动图检测心功能,应用TTC染色法检测梗死心肌面积及免疫组织化学方法检测梗死区血管密度。结果:自体血管内皮祖细胞移植1、2、4、8周后梗死区血管密度高于对照组(P<0.01),且随移植观察时间的延长,血管密度逐渐增加。移植1、2、4、8周后梗死心肌面积明显小于对照组(P<0.01),且随移植观察时间的延长,梗死心肌面积逐渐减少。内皮祖细胞移植组梗死心肌瘢痕边缘毛细血管密度明显高于对照组。内皮祖细胞移植组的左室射血分数较对照组明显提高(P<0.01),且随移植观察时间的延长,左室射血分数逐渐升高。结论:自体血管内皮祖细胞移植到心肌梗死犬缺血心肌后能分化为毛细血管内皮细胞,促进梗死后心肌血管新生及心肌修复,改善心功能。     

核素显像评价自体骨髓单个核细胞移植治疗心肌梗死后心力衰竭

目的 核素显像观察经冠状动脉自体骨髓单个核细胞移植治疗后心肌梗死心力衰竭患者的心肌血流灌注及心功能的变化,研究自体骨髓单个核细胞移植对于心肌修复和心功能的影响.方法 24例前壁心肌梗死合并心力衰竭的患者,非随机法(患者意愿)分为两组.细胞移植组(BM-MNCs组)10例,经冠状动脉骨髓细胞注射+介入治疗+标准药物治疗;对照组14人,介入治疗+标准药物治疗.所有患者分别于移植术前、术后12个月行超声心动、心肌灌注静息显像及平衡法门控心室显像.结果 术后12个月BM-MNCs组心肌血流灌注评分明显改善(46.67±3.44 vs 29.00±4.50,P=0.0015),对照组较术前无明显改变(46.33±2.80 vs 47.00±4.12,P>0.05),两组间差异具有统计学意义(29.00±4.50 vs 47.00±4.12,P=0.0157).BM-MNCs组心肌梗死区面积明显减少[(38.00±3.86)% vs (29.44±4.73)%,P=0.0009],对照组术后无显著变化[(32.70±5.02)% vs (30.30±4.92)%],两组间的变化无统计学意义.门控心血池显像结果示:移植组术后12个月LVEF值可见轻度升高,但是差异无统计学意义,结果与超声心动图一致.结论 核素心肌显像对心肌梗死后心力衰竭患者BM-MNCs移植后的疗效判断有重要价值,自体骨髓单个核细胞移植后,心肌梗死区域血流灌注得到了明显的改善,心功能得到一定的提高.     

静脉移植人脐血单个核细胞与心肌梗死家兔心肌细胞凋亡及凋亡基因bcl-2、bax

背景:研究表明经冠状动脉或经心肌内脐血干细胞移植可促进心肌梗死区血管新生、减低心肌梗死范围和改善心功能等,但脐血干细胞静脉移植对心肌细胞凋亡的影响尚不清楚.目的:观察人脐血单个核细胞静脉移植对急性心肌梗死心肌细胞凋亡及凋亡基因Bcl-2、Bax蛋白表达的影响.方法:45只成年家兔随机分3组:移植组15只,于急性心肌梗死后24h,经耳缘静脉注入2x107BrdU标记人脐血单个核细胞悬液500 μL;对照组15只,于急性心肌梗死后24h,同途径注入生理盐水500μL;假手术组15只,左前降支穿线不结扎,术后24h同途径注入生理盐水500 μL.移植后1,2,4周超声检测心功能;移植后4周心肌组织切片苏木精-伊红染色观测心肌病理变化;脱氧核糖核酸末端转移酶介导末端标记法(TUNEL)检测心肌细胞凋亡;免疫组化法检测心肌BrdU阳性细胞及Bcl-2、Bax蛋白在心肌细胞表达水平.结果与结论:①与对照组比较,移植组心功能显著改善.②移植组梗死周边区存在BrdU阳性细胞.③与对照组比较,移植组Bcl-2蛋白水平显著升高,Bax蛋白水平显著降低.④移植术后4周移植组心肌细胞凋亡数显著低于对照组.实验证实经静脉移植人脐血单个核细胞可迁移至急性心肌梗死周边区:调控急性心肌梗死后心肌细胞Bcl-2及Bax蛋白表达水平,抑制梗死周边区域心肌细胞凋亡,并改善心肌梗死后心功能.     

骨髓间充质干细胞移植对心肌梗死后心功能的影响

目的 探讨移植同种异体骨髓间充质干细胞（MSCs）是否具有改善家兔心肌梗死后心功能、缩小梗死面积的作用以及两者间的相关关系。方法 将24只大白兔随机分为急性心肌梗死（AMI）组和MSCs组,每组12只。采用局部注射法,将5-溴脱氧尿核苷（BrdU）标记的MSCs移植到兔梗死心肌边缘带和中心区。通过超声心动图测定两组手术前和术后6周心功能指标。取心脏标本用免疫组化法鉴定植入细胞,病理组织学测定梗死面积。分析心功能与梗死面积的关系。结果 MSCs组梗死心肌边缘带和中心区可见BrdU阳性细胞,AMI组未见BrdU阳性细胞。与AMI组比较,MSCs组术后6周左室舒张末期内径（LVEDD）、左室收缩末期内径（LVESD）均明显缩小（P均〈0.05）,左室射血分数（LVEF）、短轴缩短率（ΔFS%）明显增大（P均〈0.05）,组织学测量梗死面积明显缩小（P〈0.05）。两组LVEF与梗死面积均成显著负相关（P均〈0.01）。结论 MSCs移植可能通过缩小心肌梗死面积改善心功能,可用于心肌梗死的治疗。     

冠状动脉内自体骨髓干细胞移植治疗急性心肌梗死

目的观察自体骨髓干细胞冠状动脉内移植对患者心功能和心肌梗死面积的影响。方法2005年01月～2005年12月收治的36例急性心肌梗死患者在入院后随机分为骨髓干细胞移植组(n=16)和对照组(n=20)。干细胞移植组于入院后在常规治疗基础上加用自体骨髓干细胞经冠状动脉注入;对照组按急性心肌梗死常规方法治疗。于入院后第7天,术后2、4、6、8周及6月,行核素心肌灌注断层显像,测量心功能及心肌梗死面积。结果干细胞移植组术前及术后第2周与对照组的心功能及梗死面积无明显差别(P>0.05);术后第4周,患者心功能较第二周明显改善(P<0.01);第6周优于第4周(P<0.01);术后第8周与第6周无明显区别,但明显优于对照组,6月后与第6周相仿。心肌梗死面积由术前的(30.3±6.6)%下降至术后第4周(25.7±7.5)%,第6周(18.5±8.2)%,6月后为(8.2±8.5)%;而对照组变化不明显(P>0.05)。结论自体骨髓干细胞移植可减小心机梗死的范围,有效改善心功能,术后第6周效果最佳,并维持到术后6月。     

自体骨髓单核细胞移植对急性心肌梗死的作用

目的探讨未经诱导的自体骨髓单核细胞可否在梗死心肌环境中存活并分化为心肌细胞及血管内皮细胞。方法40只日本大耳雄兔随机分为两组：移植组及对照组,每组各20只。采用结扎冠状动脉左前降支的方法建立急性心梗模型,以心电图证实模型成功,由超声心动图评价心功能。模型建立后7天,将BrdU标记的自体骨髓单核细胞注射到移植组动物心肌梗死区及周边区,而对照组动物相同部位仅注射等量生理盐水。移植后6周,收集动物心脏进行组织学及免疫组化分析。结果抗BrdU免疫组化发现移植组动物心肌梗死区及周边区内均存在染色阳性的移植细胞,且周边区内的移植细胞呈心肌细胞及血管内皮细胞的形态特点,同时这些细胞抗心肌特异性肌动蛋白抗体染色阳性,证实其肌源性分化。另外,移植组动物梗死周边区血管密度显著高于对照组（P〈0.05）,但两组动物在心肌梗死区内的血管密度没有统计学差异（P〉0.05）。移植后6周,两组动物心功能均有改善,移植组明显优于对照组（P〈0.05）。结论自体骨髓单核细胞移植于梗死心肌后,可在梗死区及周边区存活,并在周边区分化为血管内皮细胞及具有心肌细胞形态特点的细胞、增加梗死周边区的血管密度,改善心功能。     

自体骨髓单个核细胞冠状动脉内移植的应用与护理

急性心肌梗死早期血运重建能减少梗死面积 ,却不能逆转心肌的坏死过程。心肌收缩单位的丢失最终导致心功能衰竭。所以心肌梗死的近期死亡率有降低 ,但远期死亡率未见明显改善[1] 。骨髓单个核细胞移植不存在免疫排斥和伦理问题 ,可以明显缩小心肌梗死面积 ,改善心功能[2 ] 。 2 0 0 3年 3月～ 2 0 0 4年 7月 ,我院对 33例患者实施了自体骨髓单个核细胞经冠状动脉内移植 ,经 6～ 12个月随访无明显副作用 ,经小样本临床观察 :多巴酚丁胺试验、PET检查、心脏超声检查证实对心肌梗死后心功能具有保护作用。在此期间成立专门的护理小组对这些患…     

经冠状动脉移植自体骨髓单个核细胞治疗犬急性心肌梗死

背景:近年的研究表明,细胞移植可以修复受损的心肌组织,促进缺血区域新生血管的形成,改善缺血心肌的灌注和收缩功能.目的:观察白体骨髓单个核细胞经冠状动脉移植至犬心肌梗死模型后在体内的分化及对心功能的影响.设计、时间及地点:随机列照动物实验,于2006-09/2008-04在天津泰达国际心血管病医院动物实验室完成.材料:成年杂种犬16只,体质量15～25 kg,通过结扎冠状动脉前降支中段建立急性心肌梗死模型.方法:16只杂种犬投币法随机分为移植组(n=10)和对照组(n=6),移植组于心肌梗死后2 h经冠状动脉内移植CM-Dil标记的骨髓单个核细胞:对照组注射等量生理盐水.冠状动脉结扎后2 h及6周时行超声心动图检查,移植后6周处死所有动物于梗死区及其邻近部位取材.主要观察指标:①心肌梗死后6局两组心功能指标比较.②荧光显微镜下观察骨髓单个核细胞在心肌组织中的分化情况.③透射电镜观察移植组梗死区心肌组织的变化.结果:纳入杂种犬16只,全部存活.左前降支结扎2 h后可见结扎点远端心肌组织变紫,室壁活动减弱,心电图出现ST段弓背样抬高.①对照组心肌梗死后6周和心肌梗死后2 h相比各项指标均无显著改善(P0.05).移植组术后6周时左心室射血分数、左心室收缩期末内径及左心室短轴缩短率均较心肌梗死后2 h有明显改善(P<0.01),其中左心室射血分数与对照组相比亦有明显改善(P<0.05),移植组射血分数较对照组提高7%左右.②荧光显微镜下可见移植组自体骨髓单个核细胞经冠状动脉移植后可分布于梗死区及梗死周边区.并表达肌球蛋白重链:正常心肌组织及对照组心肌组织内未见移植细胞.③透射电镜下可见移植组分化完全的血管内皮细胞及类心肌样细胞.结论:骨髓单个核细胞可在梗死区梗死周边区存活并逐渐分化成心肌样细胞,促进缺血心肌血管新生,改善心功能.     

人脐血单个核细胞多次静脉移植家兔急性心肌梗死后的胶原重构

背景:以往干细胞移植治疗心肌梗死的研究,均为单次经静脉或冠脉注射移植。目的:进一步验证人脐血单个核细胞多次静脉移植对家兔急性心肌梗死胶原重构及心功能影响。方法:取家兔45只结扎冠脉左前降支制备急性心肌梗死模型,随机分为3组,①多次移植组:造模后7,9,11,13d经耳缘静脉注入BrdU标记人脐血单个核细胞生理盐水。②单次移植组:造模后7d注入BrdU标记人脐血单个核细胞生理盐水,9,11,13d注入生理盐水。③心梗对照组:仅注入生理盐水。另取家兔5只为假手术组。结果与结论:与对照组相比,两移植组心功能左室短轴缩短率、左室射血分数明显升高(P<0.05);且多次移植组改善效果优于单次移植组(P<0.05);免疫组织化学显示两移植组造模后2,4周心梗周边区均存在BrdU阳性细胞,但多次移植组BrdU阳性细胞计数多于单次移植组;改良Masson’s染色显示与假手术组比较,对照组梗死区及非梗死区胶原密度显著增加,梗死区域胶原纤维部分融合,排列较紊乱,心肌基本组织结构破坏;与对照组比较,两移植组造模后2,4周梗死周边区域心肌细胞间胶原含量、胶原纤维明显减少,胶原纤维排列较为有序;与单次细胞移植组比较,多次细胞移植组进一步改善。提示多次静脉移植脐血单个核细胞改善急性心肌梗死心功能、阻抑心肌胶原纤维重构疗效优于单次静脉移植。     

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.     

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.     

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.