模拟失重大鼠心肌肌浆网Ca^2＋摄取功能的变化

为研究模拟失重对大鼠心肌肌浆网Ｃａ＾２＋摄取功能的影响，采用差速离心法制备心肌肌浆网（ＣＳＲ）精制膜，测定ＣＳＲ囊泡膜各种ＡＴＰ酶活性，并用Ｍｉｌｌｉｐｏｒｅ滤过技术测定ＣＳＲ囊泡的Ｃａ＾２＋摄取功能。结果表明，４周模拟失重大鼠心肌肌浆网膜Ｃａ＾２＋，Ｍｇ＾２＋－ＡＴＰ酶活性不变，Ｃａ＾２＋－激活ＡＴＰ酶活性却较对照组降低６．８％（Ｐ＜０．０５）。模拟失重组心肌肌浆网囊泡ＡＴＰ依赖性Ｃdisplay stat     

模拟失重可能损害心内膜内皮

４周的尾部悬吊引起大鼠乳头肌等长收缩发展张力（ＤＴ）降低２９．２％，达到张力峰值的时间（ＴＰＴ）延长１０．４％和舒张一半时间（Ｔ１／２Ｒ）呈降低趋势。解除悬吊１周大鼠的心肌收缩性能并未恢复，其表现为ＤＴ仍降低２４．Ｏ％、ＴＰＴ未见延长，但Ｔ１／２Ｒ却显著地缩短了１３．３％。用ＴｒｉｔｏｎＸ－ｌ００处理乳头肌行干预实验发现，对照大鼠的ＤＴ仅稍降低，而ＴＰＴ与Ｔ１／２Ｒ则明显缩短。与此截然相反，悬吊和恢复大鼠的ＤＴ明显降低，而ＴＰＴ与Ｔ１／２Ｒ却无改变。扫描电镜显示悬吊与恢复大鼠乳头肌内皮细胞核隆起形成的起伏消失，这些均提示模拟失重可能使大鼠心内膜内皮产生一定程度的萎缩或损伤。因此，在探讨模拟失重心血管功能失调变化机理时，心内膜内皮的作用不应忽视。     

中长期模拟失重大鼠骨骼肌线粒体钙含量和肌浆网Ca~（2＋）－ATP酶活性变化

为探讨失重对肌肉功能的影响，观察了中长期模拟失重时大鼠骨骼肌细胞内Ｃａ２＋转运功能变化，测定了比目鱼肌、腓肠肌线粒体钙含量和肌浆网（ＳＲ）Ｃａ２＋－ＡＴＰａｓｅ活性。结果是悬吊１５、３０ｄ大鼠比目鱼肌和腓肠肌线粒体Ｃａ＋２含量增加，肌浆网Ｃａ２＋－ＡＴＰ酶活性降低，说明中长期模拟失重肌细胞内Ｃａ２＋转运功能发生了改变，这可能是影响肌肉收缩特性的因素之一。     

4周悬吊大鼠比目鱼肌强直收缩力降低及其机理分析

目的：观测尾部悬吊4周大鼠比目鱼肌（SOL）强直收缩力降低的动态特征，并探讨其可能机理。方法：采用离体SOL与趾长伸肌（EDL）灌流方法。测量其单次与强直收缩张力。结果：尾部悬吊模拟失重4周，大鼠SOL明显萎缩，但EDL重量保持不变。悬吊大鼠SOL欠收缩的最大张力虽然显著降低，但未见明显的刺激电压依赖性，时间参数亦未发生改变，悬吊大鼠SOL强直收缩的最大张力显著降低，且发生迅速的衰退，在强直收缩的第33秒时，其强直收缩的张力已降低了73％，悬吊大鼠SOL强直收缩张力的动态曲线与EDL的相似，EDL的强直收缩最大张力也显著降低，但衰减速率未改变。结论：悬吊4周大鼠SOL强直收缩最大张力降低且易衰退，前者可能与单位面积内收缩装置减少以及每一横桥产力减少相关，后者则可能是由于收缩与调节蛋白异构体发生转化，以及肌肉电兴奋性改变所导致。     

中长期模拟失重大鼠骨骼肌线粒体钙含量和肌浆网Ca^2＋—A…

为探讨失重对肌肉功能的影响，观察了中长期模拟失重时大鼠骨骼肌细胞内Ｃａｗ＾２＋转运功能变化，测定了比目鱼肌，腓肠肌线粒体钙含量和肌浆网（ＳＲ）Ｃａ＾２＋－ＡＴＰａｓｅ活性。结果是悬吊１５、３０ｄ大鼠比目鱼肌和腓肠肌线粒体Ｃａ＾＋２含量增加，肌浆网Ｃａ＾２＋－ＡＴＰ酶活性降低，说明中长期模拟失重肌细胞内Ｃａ＾２＋转运功能发生了改变，这可能是影响肌肉收缩特性的因素之一。     

模拟失重大鼠心肌收缩性能降低的过程及其可逆性

采用Krebs－Henseleit溶液灌流离体乳头肌标本，观察尾部悬吊大鼠心肌收缩性能降低的过程及其可逆性。发现尾部悬吊1周后，大鼠心肌收缩性能呈增高趋势，2周后趋于降低，4周（SUS－4）后显著降低。SUS－4组：等长收编张力（DT）降低了29．2％±0．32％（P＜0．01），达到张力峰值的时间（TPT）延长了10．4％±1．7％（P＜0．05），舒张一半所需的时间（T1／2R）呈缩短趋势。又观察了悬吊4周后所致心肌收缩性能降低在解除悬吊后2周内的可逆程度。结果表明，解除悬吊后1周，没有迹象显示心肌收缩性能已恢复：DT值降低了24．0％±0．96％（P＜0．01），TPT没有明显变化，T1／2R缩短了13．3％±1．5％（P＜0．05）。而当解除悬吊2周后，乳头肌的收缩性能已基本恢复。提示悬吊4周后所引起的心肌收缩性能降低可能是失重情况下对低动力状况的一种代偿反应，并且这种由于失重所导致的心肌收缩性能降低是可逆转的，但需要相当长的一段时间恢复。     

间断性站立位对抗尾部悬吊大鼠脑动脉血管反应性变化 …

目的 探讨模拟间断性人工重力刺激对抗模拟失重下大鼠脑基底动脉血管反应性改变的效果。方法 雄性ＳＤ大鼠３５只,按体重随机分为５组,即：①同步对照组;②模拟失重组（３周尾部悬吊）;③模拟失重＋站立位４ｈ组;④模拟失重＋站立位２ｈ组;⑤模拟失重＋站立位１ｈ组。每组７只,每日分别给予站立组大鼠不同持续时间（１ｈ,２ｈ或４ｈ）的站立位（ＳＴＤ）,测定大鼠离体基底动脉血管环对ＫＣＩ的收缩反应性。结果 悬吊大鼠     

长期模拟失重大鼠心肌收缩性能的改变

应用在体及离体实验对一批悬吊90d大鼠的心肌收缩性能进行了观察。在体实验结果表明：悬吊组大鼠左室舒张本压及主动脉血压与对照组无显著性差别（P＞0．05）；但悬吊组大鼠左心室内压峰值较对照组降低16％（P＜0．01），左心室内压最大上升速率与最大下降速率也分别较对照组减慢28％（P＜0．05）与21％（P＜0．05）。对同一批大鼠的离体乳头肌，又用等长收缩灌流技术观察了力学特性变化。结果是：反映心肌收缩强度的指标，如最大发展张力（DT），在两组间无显著差别；反映心肌收缩速度的指标，如最大张力发展速率对DT的校正值，悬吊组较对照组降低了17．2％（P＜0．05）；反映收缩时程的指标，如悬吊组的至峰张力收缩时间与至峰张力发展速率收缩时间分别较对照组延长了12．7％（P＜0．01）和22．2％（P＜0．05）；反映心肌舒张的时程指标，如张力下降一半时间与至峰张力下降速率舒张时间分别较对照组延长183％（P＜0．01）与20．3％（P＜0．01）。以上结果表明，长期模拟失重大鼠心肌收缩性能明显降低，并主要表现为心肌收缩速率减慢和收缩与舒张时程延长。     

心肌功能对模拟失重状态的适应

为探讨尾部悬吊大鼠心肌收缩性能是否呈进行性能及心肌肌浆网的功能，将２４只雄性大鼠分为三维，进行为期８周的尾部悬。结果大鼠心肌等长收缩的静息张力保持不变，发展张力较同步对照组明显降低，与４周悬吊组无明显差异。悬吊８周大鼠乳头肌等长收缩达到发展张力峰值的时间，较同步对照组明显延长。     

心肌收缩成分缩短加速度的测定及在运动性心脏研究中的应用

采用经颈动脉插入导管的方法，在麻醉不开胸条件下，测试了３组（正常对照组，游泳训练组和力竭游泳组）共６１只ＳＤ大鼠心肌收缩成分缩短加速度（ａ_（ＣＥ））。结果表明：（１）ａ_（ＣＥ）类指标对正性变力和负性变力因素干预敏感性高，并与心率和舒张期室内最低压无相关性，证明了ａ_（ＣＥ）是评价心肌收缩性能敏感可靠参数之一；（２）经７周游泳训练后，大鼠心肌ａ_（ＣＥ）类指标值明显提高。力竭游泳后，ａ_（ＣＥ）指标值明显降低。展现出ａ_（ＣＥ）在运动性心脏心肌收缩性的研究中有良好的应用前景。     

Knee injury and Osteoarthritis Outcome Score (KOOS) - validation of a Swedish version

The Knee injury and Osteoarthritis Outcome Score (KOOS) is a self-administered instrument measuring outcome after knee injury at impairment, disability, and handicap level in five subscales. Reliability, validity, and responsiveness of a Swedish version was assessed in 142 patients who underwent arthroscopy because of injury to the menisci, anterior cruciate ligament, or cartilage of the knee. The clinimetric properties were found to be good and comparable to the American version of the KOOS. Comparison to the Short Form-36 and the Lysholm knee scoring scale revealed expected correlations and construct validity. Item by item, symptoms and functional limitations were compared between diagnostic groups. High responsiveness was found three months after arthroscopic partial meniscectomy for all subscales but Activities of Daily Living.     

Endovascular management of carotid-cavernous fistulas

Objective To investigate endovascular treatment of traumatic direct carotid-cavernous fistulas （CCF） and their complications such as pseudoaneurysms. Methods： Over a five-year period, 22 patients with traumatic direct CCFs were treated endovascularly in our institution. Thirteen patients were treated once with the result of CCF occluded, 8 twice and 1 three times. Treatment modalities included balloon occlusion of the CCF, sacrifice of the ipsilateral internal carotid artery with detachable balloon, coll embolization of the cavernous sinus and secondary pseudoaneurysms, and covered-stem management of the pseudoaneurysms. Results All the direct CCFs were successfully managed endovascularly. Four patients developed a pseudoaneurysm after the occlusion of the CCF with an incidence of pseudoaneurysm formation of 18.2% （4/22）. A total number of 8 patients experienced permanent occlusion of the ICA with a rate of ICA occlusion reaching 36.4% （8/22）. Followed up through telephone consultation from 6 months to 5 years, all did well with no recurrence of CCF symptoms and signs. Conclusion Traumatic direct CCFs can be successfully managed with endovascular means. The pseudoaneurysms secondary to the occlusion of the CCFs can be occluded with stent-assisted coiling and implantation of covered stents.     

The role of interventional radiology in trauma

Introduction Interventional Radiology has evolved into a specialty having enormous input into the care of the traumatized patient.In all hospitals,regardless of size,the Interventional Radiologist must consider their relationships with the trauma service in order to     

The acutely limping child

Acute limping may be the result of multiple pathologies in children. The differential diagnosis varies based on the age of the child. Irrespective of age, the initial imaging work-up includes AP and frog leg radiographs of the pelvis and ultrasound; MRI may sometimes be helpful. In children less than 3 years, infections and trauma are most frequent. MRI is the imaging modality of choice when osteomyelitis is clinically suspected. Between the ages of 3 and 10 years, transient synovitis of the hip and Legg-Calvé-Perthes disease are main considerations but infection, inflammation and focal bony lesions are also considered. In children over 10 years, slipped capital femoral epiphysis also is considered.     

Diagnóstico ecográfico del neumotórax

The ultrasonographic diagnosis of pneumothorax is based on the analysis of artifacts. It is possible to confirm or rule out pneumothorax by combining the following signs: lung sliding, the A and B lines, and the lung point. One fundamental advantage of lung ultrasonography is its easy access in any critical situation, especially in patients in the intensive care unit. For this reason, chest ultrasonography can be used as an alternative to plain-film X-rays and computed tomography in critical patients and in patients with normal plain films in whom pneumothorax is strongly suspected, as well as to evaluate the extent of the pneumothorax and monitor its evolution.     

Carbohydrate Supplementation during Exercise: Does It Help? How Much is Too Much?

KEY POINTS· Carbohydrate intake during exercise can delay the onset of fatigue and improve performance of prolonged exercise as well as exercise of shorter duration and greater intensity (e.g., continuous exercise lasting about 1h and intermittent high-intensity exercise), but the mechanisms by which performance is improved are different.     

人体中的镭-226、镭-228、钋-210、铅-210

本文报道了广东阳江高本底地区6名、对照地区8名人尸体的骨²²⁶Ra、²²⁶Ra的浓度以及部分居民内脏器官中。²¹⁰Po、²¹⁰Pb的浓度。结果轰明阳江高本底地区和对照地区居民骨镭-226、镭-228的浓度分别为29.9pCi/kg, 26.9pCi/kgl 8.7pCi/kg, 8.2pCi/kg.由此估算出阳江高本底地区屠民骨中²²⁶Ra、²²⁸Ra的负薄璧及对骨衬、骨髓所产生的剂量当量分别为对照地区民民的3.4倍, 3.3倍。两地区居民内脏器官中^{210Po、210Pb的测定分析铡数较少但仍看出, 高本底地区均明显高于对照地区.}     

磁共振DWI和动态增强鉴别颅底脊索瘤和侵袭性垂体瘤的应用

目的 探讨磁共振扩散加权成像(DWI)和动态增强在颅底脊索瘤和侵袭性垂体瘤(IPA)鉴别诊断中的应用价值.方法 搜集经手术病理证实且影像学有鞍区破坏的颅底脊索瘤患者15例、向鼻咽部侵犯的IPA患者20例.测量二者的表观扩散系数(ADC)值,绘制受试者工作特征曲线(ROC),分析动态增强曲线的类型,统计达峰时间(TTP)、增强峰值(EP)和最大对比增强率(MCER),分析各个参数在鉴别诊断中的价值.结果 颅底脊索瘤的ADC值为(1.274±0.07)×10-3mm2/s,高于IPA ADC值(0.672±0.03) ×10-3 mm2/s(P ＜0.001),ADC阈值为0.964×10-3mm2/s时,ROC曲线下面积为0.997,敏感度为93.3％,特异度为100％.颅底脊索瘤时间-信号强度曲线(TIC)Ⅰ型14例,TICⅢ型1例,此例TICⅢ型者TTP约40 s;IPA TIC Ⅰ型7例,TICⅢ型13例.颅底脊索瘤和IPA的EP、MCER差异均有统计学意义(P ＜0.001).结论 ADC值和TIC的类型及其相关参数(EP,MCER)有助于颅底脊索瘤和IPA之间的鉴别.