当归对宫内缺氧新生大鼠神经干细胞增殖、分化的影响

背景:实验小组前期研究发现孕鼠宫内缺氧可刺激胎鼠神经干细胞的增殖,缺氧6 h时增殖达高峰,在9 h也表现增殖,但能力开始下降.而缺氧达12 h时即表现为坏死或凋亡,但随缺氧天数的延长及时段的不同,对神经干细胞的影响又如何?目的:进一步探讨宫内缺氧对新生大鼠神经干细胞增殖、分化的影响及当归注射液的保护作用.方法:孕SD大鼠随机分为对照组、缺氧组和当归治疗组.孕14 d开始将当归组与缺氧组孕鼠置于三气培养箱中,制作缺氧性脑损伤新生鼠模型,此前1 h分别给于当归注射液和生理盐水尾静脉注射,对照组不缺氧,余同缺氧组.孕鼠分娩后立即取新生鼠大脑组织,经胶质纤维酸性蛋白、神经元特异性烯醇化酶免疫组织化学染色后行图像分析.结果与结论:①缺氧组新生鼠海马胶质纤维酸性蛋白免疫组织化学阳性细胞的表达较相应对照组增加;而神经元特异性烯醇化酶免疫组织化学阳性细胞的表达较对照组减小.②当归治疗组新生鼠海马胶质纤维酸性蛋白免疫组织化学阳性细胞的表达较相应缺氧组减少;而神经元特异性烯醇化酶免疫组织化学阳性细胞的表达较对照组增大.结果表明,一定程度的缺氧可刺激神经干细胞增殖,并可刺激神经干细胞向神经胶质细胞分化,以及导致神经元的减少;当归注射液可减弱由于缺氧导致的神经干细胞的增殖和向胶质细胞分化的能力,并可缓解神经元的减少,提示当归可能对缺氧大鼠神经系统有一定的保护作用.     

促红细胞生成素干预缺氧缺血性脑损伤新生鼠神经干细胞巢蛋白的表达

背景:巢蛋白是一种存在于神经干细胞的特异性抗原,在神经系统发生病变或损伤引起再生时广泛表达,因此巢蛋白表达常用作判定神经系统发生病变或损伤后能否促进神经再生的一种手段.目的:从神经再生和神经干细胞激活的角度,探讨外源性促红细胞生成素对新生鼠缺氧缺血性脑损伤后神经干细胞巢蛋白表达的影响.方法:结扎大鼠右侧颈总动脉和8%低氧暴露2 h制备新生大鼠缺氧缺血性脑损伤模型.对照组仅游离右侧颈总动脉,不予结扎和缺氧处理.干预组大鼠缺氧缺血后立即腹腔注射重组人促红细胞生成素5 000 IU/kg,1次/d,连用3 d.缺氧缺血性脑损伤组大鼠缺氧缺血后连续腹腔注射等量生理盐水溶液3d.每组随机取8只分别于术后4,7,14d处死.应用免疫组化方法和计算机图像分析技术检测不同时点海马齿状回巢蛋白标记阳性细胞的变化.结果与结论:各时点缺氧缺血性脑损伤组巢蛋白阳性细胞数较对照组增加(P<0.05);各时点干预组巢蛋白阳性细胞较对照组和缺氧缺血性脑损伤组均增加(P<0.05).3组大鼠海马齿状回区巢蛋白阳性细胞数均于术后7 d达高峰.结果提示早期给予重组入促红细胞生成素可促使新生鼠缺氧缺血性脑损伤后海马齿状回区巢蛋白表达增加,促进神经干细胞的增殖再生,在缺氧缺血性脑损伤后神经再生、修复中发挥一定的保护作用.     

新生鼠缺氧缺血性脑病水通道蛋白4与肿瘤坏死因子-α的变化及意义

目的：研究新生鼠缺氧缺血性脑病后大脑中水通道蛋白4（AQP4）与肿瘤坏死因子-α（TNF-α）的变化及意义。方法：35只7日龄新生SD大鼠分为7纽，包括对照纽（C纽）和实验组6组（缺氧缺血组），分别在缺氧缺血性脑病0、2、4、6、8、12h断头取脑，做病理切片，免疫组化分析。脑组织匀浆用放免法测定细胞因子TNF-α。结果：AQP4主要表达在脉络丛、室管膜上皮、海马及水肿区，随着时间的延长，AQP4表达呈增高趋势。对应的病理改变为细胞内水肿、炎症反应。脑组织内细胞因子TNF-α在缺氧缺血性脑病2h与对照纽相比即明显增加（P〈0.05）。结论：AQP4和TNF-α与新生鼠缺氧缺血后的脑水肿关系密切，且二者之间可能有某种关系，抑制AQP4和TNF-α可为治疗新生儿缺氧缺血性脑病开辟新的途径。     

雌激素对新生鼠缺氧缺血性脑损伤侧脑室区神经干细胞表达的影响

目的:观察雌激素对新生鼠缺氧缺血性脑损伤(HIBD)侧脑室区内源性神经干细胞表达的影响.方法:健康雄性7日龄SD大鼠80只,随机分为5组(n＝8):对照组(假手术组),缺氧缺血性脑损伤模型加橄榄油组,缺氧缺血性脑损伤模型加低浓度雌激素(10 μg/kg·d)组,缺氧缺血性脑损伤模型加中浓度雌激素(100 μg/kg·d)组,缺氧缺血性脑损伤模型加高浓度雌激素(1000 μg/kg·d)组,建立雌激素干预的浓度梯度.使用雌激素各组大鼠在制备缺氧缺血性脑损伤模型后给与每天1次颈部皮下注射雌激素,连用3天.同时,橄榄油组给与橄榄油做空白对照.取大鼠缺氧缺血性脑损伤后3天,7天为观察点.通过组织免疫荧光化学染色法,使用异硫氰酸荧光素(FITC)作为荧光二抗,检测大鼠侧脑室区神经干细胞标志物巢蛋白表达情况.结果:各组在荧光显微镜下侧脑室区均可见神经干细胞标志物巢蛋白存在所激发的绿色荧光.大鼠缺氧缺血性脑损伤后3天,对照组可见微弱的绿色荧光.与对照组比较,缺氧缺血性脑损伤模型加橄榄油组荧光增强(P＜0.05);使用雌激素各组雌激素浓度增加,绿色荧光明显增强(P＜0.01),高浓度雌激素组荧光强度最高.大鼠缺氧缺血性脑损伤后各组7天与3天比较,荧光强度减弱(P＜0.05),但组间变化趋势一致.结论:新生鼠侧脑室区有神经干细胞存在,缺氧缺血性脑损伤后有神经干细胞的增殖反应,以3天显著,7天时呈减弱趋势.雌激素对神经干细胞的增殖反应有促进作用.     

人神经干细胞移植到缺氧缺血性脑损伤新生大鼠脑内的存活及分布

目的:新生儿缺氧缺血性脑病是导致脑性瘫痪的重要原因,至今缺乏有效疗法.将体外培养的人神经干细胞经脑室移植入缺氧缺血性脑损伤新生鼠,观察植入细胞在宿主脑内的存活、迁移及分化.方法:实验于2005-01/09在解放军海军总医院儿科实验室完成.①对象:神经干细胞来源于孕12周流产的人胎儿脑组织,孕妇签署知情同意书,符合医院伦理委员会规定.清洁级SD新生鼠80只,随机数字表法分为细胞移植组、模型对照组,40只/组,实验过程中对动物的处置符合动物伦理学标准.②实验方法:取人胚胎脑组织,机械分散法分离单个核细胞,接种于添加表皮生长因子、碱性成纤维细胞生长因子、白血病抑制因子的N2培养基中,获取生长旺盛的人神经干细胞球,制成单细胞悬液,浓度约为5.0×1011L-1,培养6 d后行PKH标记用于植入后示踪.两组新生鼠均建立缺氧缺血性脑损伤模型,造模后3 d,细胞移植组损伤侧脑室缓慢注入5 μL人神经干细胞悬液,模型对照组于相同部位注入等量生理盐水.③实验评估:取未经PKH标记的细胞球, 通过免疫细胞化学染色鉴定巢蛋白的表达及其向神经元、星形胶质细胞的分化情况.分别于细胞移植后1,2,4周及3个月,常规取脑组织,行免疫组织化学和荧光分析,观察植入后细胞存活及分布情况.结果:在造模及细胞移植过程中,因麻醉、出血细胞移植组新生鼠死亡5只,模型对照组死亡7只,存活率85%～90%.①神经干细胞的鉴定及分化:80%活细胞巢蛋白呈阳性表达,并可分化为神经元、星形胶质细胞.②神经干细胞植入后存活及分布情况:植入后1周,神经丝蛋白阳性细胞多位于损伤侧皮质及海马处,纹状体、脑干、小脑、嗅球也有少量分布.植入后2周,海马和皮质可见神经丝蛋白阳性细胞,胞体伸出的神经微丝更长,细胞数量与1周时基本相似.植入后4周及3个月时PKH阳性细胞数量明显减少.结论:在含有表皮生长因子、碱性成纤维细胞生长因子、白血病抑制因子的N2培养基中形成的人神经干细胞球,具有良好的增殖能力,可分化为神经元,移植至缺血缺氧新生鼠脑中能够向损伤区迁移,分布范围广.     

单唾液酸四已糖神经节苷脂对新生大鼠脑缺氧缺血的保护作用

背景：目前研究认为，Mr70000热休克蛋白(HSP70)是缺氧缺血的敏感指标。单唾液酸四已糖神经节苷脂(Monosialotrahexosylganglioside,GM1)是哺乳类神经节苷脂的主要种类，HSP70及GM。在新生儿缺氧缺血性脑损伤(hypoxic-ischemic encephalopathy,HIE)中的作用及机制目前尚不清楚。目的：研究新生大鼠缺氧缺血性脑损伤(hypoxia-ischemia brain damage,HIBD)后海马CA1区Mr70000热休克蛋白(HSP70)表达、病理学损伤变化和外源性GM1对其的影响。设计：完全随机对照的实验研究地点、材料和干预：本实验在解放军第四军医大学航空医学系及第四军医大学西京医院病理科完成，实验采用7日龄SD乳鼠，按随机抽签法分成3组，正常对照组6只，缺氧缺血组24只，缺血后治疗组24只干预：建立HIBD模型，用免疫组化及苏木素-伊红(HE)染色方法检测缺氧缺血和GM．干预后不同时间点脑海马组织HSP70阳性细胞及病理学改变。主要观察指标：正常大鼠、缺氧缺血大鼠及缺氧缺后给予GM1大鼠的海马CA1区HSP70染色程度及神经损伤分级比较。结果：HI后新生大鼠海马CA1区仅能检出少量阳性HSP核蛋白，呈1级染色，海马CA1区神经元呈较严重的缺血损伤性改变，损伤程度达3—4级，而GM1组可见应激蛋白HSP70明显表达，24h达高峰，呈2—3级染色；神经元损伤程度为0—2级。结论：GM1可使新生大鼠海马CA1区HSP70表达上调，减轻脑缺氧缺血后病理损伤，对新生大鼠缺氧缺血性脑损伤具有保护作用。     

高压氧治疗缺氧缺血性脑病的应用特征

目的:了解高压氧在治疗缺氧缺血性脑病方面的应用进展。资料来源:检索Medine1980-01/2005-01与高压氧治疗缺氧缺血性脑病临床及基础研究的文章,检索词“hyperbaricoxygen,hypoxic-ischemicencephalopathy”,并限定文章语言种类为英文。检索清华全文数据库2003-01/2005-12关于高压氧治疗缺氧缺血性脑病临床及基础研究的文章,限定文章语言种类为中文,检索词“高压氧,缺氧缺血性脑病”。资料选择:对资料进行初审,筛除明显不随机的研究,对剩余的文献开始查找全文。纳入标准为①随机对照研究;②实验或临床研究包含平行对照组。排除标准:重复性研究。资料提炼:共收集到109篇关于高压氧治疗缺氧缺血性脑病应用方面的文章,25个实验或临床研究符合纳入标准。排除的84篇为未随机研究或重复性研究。资料综合:高压氧可提高血氧浓度,改善各脏器组织氧的供应,改善脑组织代谢,促进脑损伤修复;高压氧可使脑组织内供氧正常的部位血管收缩,脑血流量减少,但可使受损部位的脑血管扩张,增加缺血区脑血流量,减轻脑水肿;提高脑干网状激活系统等部位的氧分压,从而在缺氧缺血性脑病时发挥对脑的保护和修复作用。高压氧可在脑缺血/再灌注损伤中能提高人和动物的存活率,使存活时间延长、脑梗死容量减少、行为功能改善。结论:高压氧治疗缺氧缺血性脑病,除少数学者对高压氧治疗缺氧缺血性脑病的效果持异议外,多数研究者利用动物模型从多个层面证明高压氧治疗缺氧缺血性脑病有一定效果,能改善缺氧缺血性脑病急性期的临床症状和体征,促进脑功能的康复和大脑发育,减少后遗症的发生,不过,用于实验研究的动物多数为成年动物,忽略了新生婴儿大脑处于高速发育期,可塑性极大这一至关重要因素,在评价疗效时只有近期疗效;选用的缺氧缺血性脑病动物模型与人类分娩所造成的新生儿缺氧缺血性脑病的临床现实情况存在较大差异。     

脐血间充质干细胞移植修复缺氧缺血损伤新生大鼠的脑功能

背景：课题计划从神经细胞替代、促进内源性神经干细胞增殖和分化、保护神经元、促进突触重建以及减轻脑白质损伤等方面来探讨脐血间充质干细胞系统移植对新生大鼠缺氧缺血脑损伤后神经功能的修复作用及其机制。目的：观察脐血间充质干细胞由静脉途径移植透过血脑屏障进入脑组织内．对新生大鼠缺氧缺血性脑损伤后脑功能修复的影响。方法：7d龄SD新生鼠分为3组：假手术组仅分离出左侧颈总动脉而不结扎;缺氧缺血脑损伤组制备缺氧缺血脑损伤模型;细胞移植组在缺氧缺血性脑损伤后第8天尾静脉移植人脐血间充质干细胞,前两组尾静脉注射等量的生理盐水。结果与结论：免疫荧光观察显示移植后5周脐血间充质干细胞迁移到海马,Nissl染色结果显示脐血间充质干细胞移植后,左侧海马DG区锥体细胞尼氏小体明显增加,提示间充质干细胞移植后可分化为神经元。行为学测试结果显示：与假手术组相比,缺氧缺血脑损伤组在T迷宫实验中,自发改变率下降,在放射形迷宫中觅水时间延长,错误次数及重复次数明显增加（P〈0．05）：脐血间充质干细胞静脉移植5周后,上述行为学指标均显著改善（P〈0．05）。提示脐血间充质干细胞静脉移植治疗明显改善和提高了缺氧缺血脑损伤大鼠远期的学习记忆和空间辨别能力。     

高压氧对外源性人神经干细胞移植治疗损伤脑组织神经元病理状态的改善效应

目的:研究证明高压氧治疗能明显减轻缺氧后宿主脑区深部水肿,减少内源性神经元变性与坏死,并增加围产期鼠新生神经元数量与碱性成纤维生长因子活性.实验拟进一步观察缺氧缺血性脑损伤大鼠移植人神经干细胞后予高压氧治疗对脑组织神经元病理改变的影响.方法:实验于2007-04在解放军海军总医院完成.①细胞来源及动物:经医院伦理委员会授权,孕妇知情同意下留取孕12周流产的人胎儿脑组织.新生7 d龄SD大鼠20只,购自北京维通利华实验动物技术有限公司,实验过程中对动物的处置符合动物伦理学标准.②实验方法:取胎儿脑组织,在无菌条件下培养扩增并制备成人神经干细胞单细胞悬液.20只大鼠均建立缺氧缺血性脑损伤模型,3只死亡,剩余鼠随机数字表法分为2组,细胞移植 高压氧组9只,单纯细胞移植组8只.造模后3 d,两组大鼠均于左侧侧脑室进行细胞移植,注射位点以前囟为参照点,AP= -1 mm,ML= -1.5 mm,DV= -4.0 mm,缓慢注入2×106 L-1细胞悬液5 μL.移植后1 h,将细胞移植 高压氧组大鼠放入高压氧舱内,给予高压氧通气,升压及降压过程各15 min,最终达压力为1.8个绝对大气压,稳压60 min,1次/d,连续10 d.两组大鼠麻醉后断头取脑,制备组织切片.③实验评估:免疫荧光法检测神经干细胞巢蛋白的表达、人神经干细胞植入后神经丝蛋白表达及其向神经元分化情况.尼氏染色检测移植后脑组织皮质、海马神经元形态、结构的变化.结果:移植过程中细胞移植 高压氧组有1只鼠因麻醉死亡,高压氧通气过程中没有动物死亡.①人神经干细胞的鉴定:人胎儿脑组织体外培养12 d获取生长旺盛的人神经干细胞小集落,即神经球.倒置显微镜下观察可见每个小集落为数十个细胞构成,细胞折光性强,周边有清晰的光晕.免疫荧光标记大部分活细胞表达巢蛋白.②人神经干细胞植入后神经丝蛋白表达及其向神经元分化:植入后10 d,两组在皮质及海马区均可见神经丝蛋白阳性细胞,即植入细胞分化形成的神经元,其细胞形态与宿主内源性细胞相似.③神经元尼氏染色:两组大鼠均没有发现肿瘤形成.移植后10 d与单纯细胞移植组相比,细胞移植 高压氧组海马及皮质区组织细胞水肿程度明显减轻,且海马CA1区、CA3区、齿状回神经元排列更整齐,组织结构更完整.结论:缺氧缺血性脑损伤新生大鼠移植人神经干细胞后,高压氧治疗可减轻损伤易感区组织细胞水肿程度,并使海马区神经元结构更加完整,推测有可能促进细胞的成活、迁移及分化.     

高压氧治疗缺氧缺血性脑病的应用特征

目的：了解高压氧在治疗缺氧缺血性脑病方面的应用进展。资料来源：检索Medine1980-01／2005-01与高压氧治疗缺氧缺血性脑病临床及基础研究的文章，检索词“hyperbaric oxygen,hypoxic-ischemic eneephalopathy”，并限定文章语言种类为英文。检索清华全文数据库2003—01／2005-12关于高压氧治疗缺氧缺血性脑病临床及基础研究的文章，限定文章语言种类为中文，检索词“高压氧，缺氧缺血性脑病”。资料选择：对资料进行初审，筛除明显不随机的研究，对剩余的文献开始查找全文。纳入标准为①随机对照研究;②实验或临床研究包含平行对照组。排除标准：重复性研究。资料提炼：共收集到109篇关于高压氧治疗缺氧缺血性脑病应用方面的文章，25个实验或临床研究符合纳入标准。排除的84篇为未随机研究或重复性研究。资料综合：高压氧可提高血氧浓度，改善各脏器组织氧的供应，改善脑组织代谢，促进脑损伤修复；高压氧可使脑组织内供氧正常的部位血管收缩，脑血流量减少，但可使受损部位的脑血管扩张，增加缺血区脑血流量，减轻脑水肿；提高脑干网状激活系统等部位的氧分压，从而在缺氧缺血性脑病时发挥对脑的保护和修复作用。高压氧可在脑缺血／再灌注损伤中能提高人和动物的存活率，使存活时间延长、脑梗死容量减少、行为功能改善。结论：高压氧治疗缺氧缺血性脑病，除少数学者对高压氧治疗缺氧缺血性脑病的效果持异议外，多数研究者利用动物模型从多个层面证明高压氧治疗缺氧缺血性脑病有一定效果，能改善缺氧缺血性脑病急性期的临床症状和体征，促进脑功能的康复和大脑发育，减少后遗症的发生，不过，用于实验研究的动物多数为成年动物，忽略了新生婴儿大脑处于高速发育期，可塑性极大这一至关重要因素，在评价疗效时只有近期疗效；选用的缺氧缺血性脑病动物模型与人类分娩所造成的新生儿缺氧缺血性脑病的临床现实情况存在较大差异。     

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.     

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.     

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.