神经肌肉功能重建术式对大鼠肱二头肌生物学功能影响的实验研究

目的:分析靶向肌肉神经功能重建术(TMR)和靶向神经功能替代术(TNFR)对大鼠肱二头肌生物学功能的影响。方法:SPF级SD大鼠随机分为两组,分别离断尺神经和肌皮神经,一组将尺神经的近端植入肱二头肌构建TMR动物模型,另一组将已离断的尺神经近端与肌皮神经远端吻合,构建TNFR动物模型。通过检测肱二头肌肌张力,计算肌湿重维持率,进行运动终板染色等方式评价两种手术模式的应用效果。结果:(1)TNFR组肱二头肌的最大单收缩力(12.17±5.03)g明显高于TMR组肱二头肌的最大单收缩力(3.00±1.54)g(P0.05);(2)TNFR组的肌湿重维持率(1.02±0.09)g高于TMR组(0.78±0.22)g(P0.05);(3)两组模型均能染出运动终板,但是TNFR组运动终板数量(8.17±1.47)较TMR组数量(3.00±1.79)多(P0.05)。结论:相较于TMR模型,TNFR模型能够减缓肌肉因失神经支配而出现的肌萎缩现象,更加有效支配肱二头肌。     

睫状神经营养因子基因转染延缓失神经肌萎缩的作用

背景睫状神经营养因子(CNTF)对失神经支配骨骼肌萎缩有防治作用,但是否可以应用CNTF基因转染方法延缓失神经支配骨骼肌萎缩尚不清楚.目的探索一次性电穿孔介导CNTF转染延缓失神经骨骼肌萎缩的疗效.设计随机对照研究.地点和对象在上海交通大学附属第一人民医院动物房完成,雄性SD大鼠36只,年龄两三个月,体质量250～300 g,由上海中科院实验动物中心提供.干预制备36只大鼠右下肢腓肠肌失神经支配模型,随机平均分成失神经对照组,CNTF基因转染组.两组于术后2,4,8周分别取6只大鼠进行实验评价.主要观察指标两组术后2,4,8周肌湿重维持率、肌细胞截面积、肌肉蛋白含量、胶原纤维与肌细胞面积比和细胞凋亡数.结果2周和4周CNTF基因转染组的肌湿重维持率、肌细胞截面积和肌肉蛋白含量均明显高于失神经对照组(P＜0.05),而胶原纤维与肌细胞面积比和细胞凋亡数明显低于失神经对照组(P＜0.05).8周后,两组间各参数无明显区别(P＞0.05).结论一次性电穿孔介导CNTF基因转染可延缓失神经骨骼肌萎缩4周.     

经皮电刺激大鼠骨骼肌失神经肌萎缩时成肌调节因子基因的表达

背景:在去神经早期大鼠骨髂肌成肌调节因子(MyoD)表达明显上调,有明显延缓骨骼肌肌萎缩的作用.临床实验证实电刺激是治疗失神经肌萎缩的有效方法.尚未有实验证实电刺激对失神经肌萎缩MyoD表达的影响.目的:验证电刺激对大鼠骨骼肌MyoD基因表达的影响.设计、时间及地点:随机对照动物实验,于2008-07/11在山西医科大学动物实验中心完成.材料:健康的SD大鼠36只,雌雄不限.随机分成3组,即空白对照组、去神经组、电刺激组,每组12只.方法:空白对照组不做任何处理;去神经组和电刺激组大鼠制作右侧坐骨神经离断,腓肠肌失神经支配模型.用电刺激对电刺激组进行刺激,1次/d,30 min/次.分别于去神经第2,7,14,28天,处死大鼠,取小腿的腓肠肌肉标本.主要观察指标:用反转录聚合酶链式反应技术检测MyoD mRNA的表达变化,免疫组织化学检测MyoD蛋白表达的变化.结果:在去神经支配后第2,7,14,28天,去神经组和电刺激组标本中MyoDmRNA和蛋白含量表达上调,与空白对照组比较差异有显著性意义(P＜0.05),电刺激组表达高于去神经组(P＜0.05).结论:通过电刺激可以上调大鼠腓肠肌失神经模型MyoD的表达,说明电刺激是延缓骨骼失神经肌萎缩的有效方法.     

低频电刺激对坐骨神经损伤大鼠不同类型骨骼肌萎缩及内源性胰岛素样生长因子1表达的影响

背景：低频电刺激可以缓解骨骼肌的萎缩,但对肌纤维类型的影响尚不清楚,同时内源性胰岛素样生长因子1在萎缩后的肌纤维中的表达与电刺激的关系尚无公识。目的：观察低频电刺激对坐骨神经损伤大鼠不同类型骨骼肌纤维萎缩情况及内源性胰岛素样生长因子1表达的影响。方法：将健康雄性SD大鼠随机分为3组,切断模型组和电刺激组大鼠左侧坐骨神经制备失神经支配模型,适应5d后,对电刺激组大鼠损伤侧腓肠肌施以2Hz的电刺激,2次/d,每次持续20min,正常组和模型组常规饲养。30d后,取大鼠腓肠肌腹部,检测其肌纤维直径和数量;免疫组织化学法检测肌组织中胰岛素样生长因子1的水平。结果与结论：失神经支配后,大鼠腓肠肌Ⅰ、Ⅱ型肌纤维直径减小,Ⅰ型肌纤维数比例增大。与模型组比较,电刺激组大鼠腓肠肌Ⅰ、Ⅱ型肌纤维直径有所增大,尤以Ⅰ型肌纤维直径增大更明显（P〈0.05）。同时,电刺激组大鼠腓肠肌中胰岛素样生长因子1的表达也明显高于模型组（P〈0.05）。提示,2Hz的电刺激可促进胰岛素样生长因子1的表达,减轻Ⅰ型肌纤维的萎缩。     

低频电刺激对坐骨神经损伤大鼠不同类型骨骼肌萎缩及内源性胰岛素样生长因子1表达的影响

背景:低频电刺激可以缓解骨骼肌的萎缩,但对肌纤维类型的影响尚不清楚,同时内源性胰岛素样生长因子1在萎缩后的肌纤维中的表达与电刺激的关系尚无公识。目的:观察低频电刺激对坐骨神经损伤大鼠不同类型骨骼肌纤维萎缩情况及内源性胰岛素样生长因子1表达的影响。方法:将健康雄性SD大鼠随机分为3组,切断模型组和电刺激组大鼠左侧坐骨神经制备失神经支配模型,适应5d后,对电刺激组大鼠损伤侧腓肠肌施以2Hz的电刺激,2次/d,每次持续20min,正常组和模型组常规饲养。30d后,取大鼠腓肠肌腹部,检测其肌纤维直径和数量;免疫组织化学法检测肌组织中胰岛素样生长因子1的水平。结果与结论:失神经支配后,大鼠腓肠肌Ⅰ、Ⅱ型肌纤维直径减小,Ⅰ型肌纤维数比例增大。与模型组比较,电刺激组大鼠腓肠肌Ⅰ、Ⅱ型肌纤维直径有所增大,尤以Ⅰ型肌纤维直径增大更明显(P<0.05)。同时,电刺激组大鼠腓肠肌中胰岛素样生长因子1的表达也明显高于模型组(P<0.05)。提示,2Hz的电刺激可促进胰岛素样生长因子1的表达,减轻Ⅰ型肌纤维的萎缩。     

睫状神经营养因子基因转染延缓失神经肌萎缩的作用

背景：睫状神经营养因子(CNTF)对失神经支配骨骼肌萎缩有防治作用，但是否可以应用CNTF基因转染方法延缓失神经支配骨骼肌萎缩尚不清楚。目的：探索一次性电穿孔介导CNTF转染延缓失神经骨骼肌萎缩的疗效。设计：随机对照研究。地点和对象：在上海交通大学附属第一人民医院动物房完成，雄性SD大鼠36只，年龄两三个月，体质量250-300g，由上海中科院实验动物中心提供。干预：制备36只大鼠右下肢腓肠肌失神经支配模型，随机平均分成失神经对照组，CNTF基因转染组。两组于术后2，4，8周分别取6只大鼠进行实验评价。主要观察指标：两组术后2，4，8周肌湿重维持率、肌细胞截面积、肌肉蛋白含量、胶原纤维与肌细胞面积比和细胞凋亡数。结果：2周和4周CNTF基因转染组的肌湿重维持率、肌细胞截面积和肌肉蛋白含量均明显高于失神经对照组(P&;lt;0．05)，而胶原纤维与肌细胞面积比和细胞凋亡数明显低于失神经对照组(P&;lt;0．05)。8周后，两组间各参数无明显区别(P&;gt;0．05)。结论：一次性电穿孔介导CNTF基因转染可延缓失神经骨骼肌萎缩4周。     

骨髓间充质干细胞成肌诱导后移植对延缓失神经肌肉萎缩的作用

目的:实验将化学和应力协同诱导后的大鼠骨髓间充质干细胞移植到失神经骨骼肌内,观察体内的成肌效应,以达到延缓失神经骨骼肌萎缩的目的.方法:实验于2007-04/10在上海交通大学医学院附属新华医院动物实验中心和中心实验室完成.①实验材料:SD大鼠由上海西普尔-必凯实验动物有限公司提供,实验过程中对动物处置符合动物伦理学标准.②实验方法:采用密度梯度离心法分离培养雄性SD大鼠股骨、胫骨中骨髓间充质干细胞.取第3代细胞进行化学诱导后,再进行应力诱导,于移植前1d以DAPI标记.取8周龄SD大鼠36只,随机分为对照组与实验组,18只,组.两组均切断大鼠左侧后肢坐骨神经,并造成1 cm神经缺损,形成失神经支配腓肠肌动物模型.实验组大鼠腓肠肌的内、外侧头经皮注入骨髓间充质干细胞,对照组大鼠以同样方法注入无细胞、不含胎牛血清低糖DMEM培养液.⑨实验评估:术后第4,8,12周检测大鼠双侧腓肠肌运动单位电位及纤颤电位,取双侧腓肠肌测定肌湿重,然后行苏木精-伊红染色,并作图象分析,测定肌纤维横截面积,采用BCA法测双侧腓肠肌蛋白总量.结果:①切断坐骨神经后2周大鼠腓肠肌均发生不同程度的萎缩.左侧腓肠肌运动单位电位波形逐渐变单一,时限逐渐延长,电压逐渐变小,纤颤电位的正向波逐渐增多.4、8周时实验组与对照组有差异,12周时两组无差异.②实验组骨髓间充质干细胞移植处可观察到带荧光的细胞核及肌纤维,对照组未见此现象.实验组第4,8周失神经支配腓肠肌湿重残存率、腓肠肌纤维横截面积残存率、蛋白总量残存率均明显低于对照组(P<0.01),12周时两组差异无统计学意义.结论:骨髓间充质干细胞移植到失神经骨骼肌内可明显延缓失神经支配骨骼肌的萎缩,并且这一作用只在细胞移植8周以内比较明显.     

成肌调节因子Myf-5在失神经骨骼肌萎缩不同时段的表达

背景:成肌调节因子Myf-5是参与肌肉发生过程分子调控、启动和维持骨骼肌细胞生长发育的重要基因,可能与失神经骨骼肌萎缩的发生有关.目的:观察不同部位、不同时段骨骼肌失神经支配后成肌调节因子Myf-5基因的表达情况.设计、时间及地点:随机对照动物实验,于2008-03104在山西医科大学完成.材料:选择健康8周龄雄性SD大鼠24只,随机分成4组,即假手术组(有神经支配)、去神经2 d组、去神经7 d组、去神经28 d组,每组6只.方法:假手术组不切断坐骨神经,仅做假手术.去神经组右下肢后部中段切断坐骨神经1 cm以上,分别于去神经第2,7,28天用脊椎脱臼法处死大鼠,分离出右小腿的胫骨前肌、比目鱼肌、腓肠肌、跖肌标本.主要观察指标:用反转录-聚合酶链反应技术检测各组肌肉Myf5 mRNA表达情况,抗Myf-5多克隆抗体免疫组织化学染色(ABC法),测量灰度值.结果:去神经骨骼肌早期,Myf-5的mRNA在去神经支配后第2,7,28天均表达上调(P<0.05).Myf-5抗体阳性染色细胞核数在SD大鼠骨骼肌失神经28 d时的肌卫星细胞中最多.结论:Myf-5在大鼠失神经骨骼肌萎缩早期不同肌肉表达均为上调.大鼠骨骼肌失神经支配后早期肌卫星细胞中Myf-5表达上调.     

失神经支配的骨骼肌萎缩与防治

背景:随着当今医学的发展,失神经支配骨骼肌萎缩的防治已取得了显著的进步,但临床疗效仍不十分满意.目的:对火神经支配骨骼肌萎缩防治方法的研究现状作一总结,试图寻找更为有效的失神经支配骨骼肌萎缩防治方法.方法:以denervation,muscle atrophy,treatment为检索词,检索Medline数据库(1998-01/2008-01).以失神经,肌萎缩,治疗为检索词,检索中国期刊全文数据库(1998-01/2008-01)、万方数据库(1998-01/2008-01)和<中国临床康复>杂志(1998-01/2008-01).文献柃索语种限制为英文和中文.以肌肉的耐力及收缩力、失神经的肌湿重和骨骼肌的修复情况为评价指标.纳入研究失神经支配骨骼肌萎缩的显微外科手术方法、物理疗法、生物和化学疗法、基因疗法.排除上述方法之外失神经支配骨骼肌萎缩的其他疗法.结果与结论:周围神经损伤后,骨骼肌失神经支配将不可避免的发生萎缩.因此,探索失神经支配骨骼肌萎缩的防治方法,吸引了国内外许多学者的兴趣,必将成为21世纪周围神经领域内的重要任务和研究热点.显微外科手术、物理疗法、生物和化学疗法、基因疗法等都是失神经支配骨骼肌萎缩有效的防治手段.目前,该领域的研究已经呈现多角度、多方面的趋势.失神经肌萎缩的防治方面已经有了针对性的措施,但在改善微循环、防止细胞凋亡、抑制胶原过度生长以及如何应用基因治疗的方法在基因水平改变生肌调节因子的表达等方面,还有大量工作需要进行.随着组织工程学、细胞培养学、分子生物学、基因工程等方面的不断发展,防治失神经肌萎缩必定会有新的突破.     

咀嚼肌瓣面神经再支配的实验研究

目的 :探讨失神经支配的咬肌瓣获得面神经再支配后的结构特性变化。方法 :取 2 0只新西兰大白兔 ,分为两组 (每组 10只 ) :A组行面神经 -咬肌神经端端移植吻合 ;B组行面神经咬肌内移植植入。术后分别在第1、3、6个月进行大体观察及肌湿重测定、电生理检查、酶组织化学检查及超微结构观察。结果 :失神经咬肌可重获面神经再支配 ,并在面神经支配下行使收缩功能 ,肌纤维的组化型别发生改变 ,从而使咬肌的肌纤维类似于表情肌。两种神经支配方法在术后 3个月MCV的恢复均有显著差异 (P <0 0 1) ;术后 6个月 ,两者无显著差异 (P >0 0 5 )。结论 :两种方法结果相似 ,均能使移植肌重获神经支配 ,恢复收缩功能。但在一期手术时 ,神经肌内植入方法简单 ,效果较移植吻合法相同 ,对临床手术治疗面瘫有一定的借鉴作用     

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.     

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.     

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.