Duchenne型肌营养不良症中神经元型一氧化氮合酶和utrophin的表达水平

目的研究神经元型一氧化氮合酶(n NOS)和抗肌萎缩蛋白相关蛋白(utrophin)在Duchenne型肌营养不良症(DMD)中的表达水平及与病情的关系,并探讨DMD中抗肌萎缩蛋白(dystrophin)、n NOS、utrophin 3者间的相关性。方法收集DMD患者26例,并分为轻症组(19例)和重症组(7例),收集正常对照患者21例,利用免疫荧光方法检测n NOS和utrophin的表达并进行统计分析。结果 DMD患者中23例n NOS呈完全缺失、3例明显减少,22例DMD患者utrophin表达增多,4例患者utrophin阴性表达,正常对照中n NOS均为阳性、utrophin均为阴性,DMD患者n NOS表达减少而utrophin表达增多(Z=-6.557、-5.426,P0.05)。轻症组与重症组比较n NOS、utrophin的表达水平均无统计学意义。相关分析DMD中utrophin与dystrophin的表达水平呈负相关(r=-0.419,P0.05),而n NOS与utrophin、dystrophin均无相关性。结论 DMD患者中n NOS的表达减少、utrophin的表达增多,且两者可能参与DMD的病理过程。     

DMD、BMD患者骨骼肌、皮肤立毛肌肌营养不良蛋白同时欠损

目的研究、对比肌营养不良蛋白(dystrophin)在杜兴型肌营养不良(Duchenne muscular dystrophy,DMD)和贝克型肌营养不良(Becker muscular dystrophy,BMD)患者活检骨骼肌、皮肤立毛肌中的表达。方法用肌营养不良蛋白三个不同区域的单克隆抗体(Dystrophin-N、-C、-R)对11例DMD患者,5例BMD患者和3例其他神经肌病患者同时行活检骨骼肌、皮肤免疫组织化学染色分析。结果与对照例相比,11例DMD患者抗Dystro-phin-N、-C、-R单克隆抗体免疫组织化学染色显示:骨骼肌肌纤维膜Dystrophin-N、-C、-R呈完全欠损;皮肤立毛肌Dystrophin-N、-R完全欠损,Dystrophin-C轻微表达。5例BMD患者抗Dystrophin-N、-C、-R单克隆抗体免疫组织化学染色显示:肌营养不良蛋白在骨骼肌肌纤维膜和皮肤均呈不完全欠损。结论DMD和BMD患者肌营养不良蛋白在骨骼肌肌纤维膜、皮肤立毛肌呈完全/不完全欠损,与骨骼肌活检相同,皮肤活检也是分子病理学诊断DMD、BMD简便、易行、可靠的方法。     

抗肌萎缩蛋白免疫组化在青少年肌肉疾病中的诊断价值

目的 探讨抗肌萎缩蛋白(dystrophin)表达对青少年肌肉疾病诊断和鉴别诊断的价值.方法 应用免疫组织化学染色,对84例年龄＜25岁的肌肉疾病和2名正常肌肉活检组织进行dystrophin检测,同时用组织化学三磷酸腺苷酶(ATP酶)、还原性尼克酰胺腺嘌呤二核苷酸(NADH-Tr)、改良Gomori、糖原PAS和脂肪苏丹Ⅲ染色法,同时对这些病例进行检测,以作为肌营养不良与其他肌肉疾病的鉴别诊断.结果 正常肌肉组织dystrophin表达强阳性.Duchenne型肌营养不良(Duchenne muscular dystrophy,DMD)中80%病例的肌纤维dystrophin免疫呈阴性反应,20%病例呈不连续点状或不完整线状弱阳性.在Becker型肌营养不良(Becket musculax dystrophy,BMD),所有的病例肌纤维都有不连续点状或不完整线状弱阳性,而其他类型的肌营养不良包括肢带型肌营养不良和强直型肌营养不良的肌纤维均为100%阳性率.另外,除1例糖原累积性肌病出现dystrophin弱阳性反应外,其他的肌肉疾病,包括炎症性肌病、线粒体肌病、神经源性肌萎缩、脂肪累积性肌病、轴空病和中央核肌病dystrophin阳性率为100%.结论 dystrophin免疫组化检测是诊断DMD/BMD可靠和有效的方法,结合形态学改变和组化染色,可以与其他肌肉疾病进行鉴别诊断.     

Utrophin蛋白的分子生物学研究进展

Duchenne型肌营养不良（DMD）是一种X-连锁隐性遗传的肌肉变性病,是由Xp21上的抗肌萎缩蛋白（dystrophin）基因突变所致dystrophin蛋白缺乏引起的疾病.新生男婴DMD发生率大约是1/3500,患者肌无力发展迅速,11～13岁后完全不能行走,大部分在20岁左右死于周围性呼吸循环衰竭.由于utrophin蛋白与dystrophin蛋白有着结构的同源性和相似的功能,通过转基因方法使细胞表面utrophin蛋白水平提高2～3倍,可以使DMD模型动物mdx鼠肌肉的形态和功能得到修复,而这仅是正常肾组织utrophin蛋白水平的大约50%,肺的25%,被认为是基因治疗DMD的非常有希望的替代物.现将其分子生物学研究进展综述如下.     

免疫组织化学dystrophin染色诊断Duchenne型肌营养不良症的研究

目的 探讨Duchenne型肌营养不良症(DMD)肌萎缩蛋白(dystrophin)表达规律和临床意义.方法 收集我院7例DMD患者作为试验组,7例非DMD患者为对照组.使用抗dystrophin杆状结构域单抗、免疫组织化学染色,观察肌膜dystrophin表达.结果 7例DMD患者肌细胞膜dystrophin阴性,7例非DMD患者dystrophin染色阳性.结论 证实DMD患者肌细胞膜dystrophin表达阴性,揭示dystrophin缺失是其发病机制,可以作为确诊DMD手段,对临床诊断DMD有实际意义.     

基因治疗假肥大型肌营养不良症后机体的免疫反应

假肥大型肌营养不良症(DMD)是抗肌萎缩蛋白(dystrophin)基因突变致肌膜上dystrophin完全或部分缺失引起的。基因或干细胞治疗该病的目的是使其表达有功能的dystrophin,因多数DMD患者治疗前体内没有dystrophin,基因治疗后正常的dystrophin会被患者的免疫系统识别并引发免疫反应,进一步破坏病变的肌肉组织。本文介绍了基因治疗DMD后机体产生抗dystrophin的机制及免疫耐受,并探讨了今后临床治疗DMD的策略。     

假肥大型肌营养不良肌肉组织神经元型一氧化氮合酶的变化

目的 观察假肥大型肌营养不良患者骨骼肌组织中nNOS的表达情况。方法 用NADPH－黄递酶组织化学染色法和抗nNOS抗体免疫组织化学法对正常对照（10名）、肌营养不良（36例）和其他神经肌肉病患者（18例）肌组织标本进行分析。结果 发现正常对照和非肌营养不良神经肌肉病以及LGMD、FSHD屠 肌膜上染色阳性，DMD肌膜上染色阴性，BMD肌膜上染色弱阳性或阴性。结论 正常对照和非DMD／BMD神经肌肉病肌膜上存在丰富的nNOS,DMD/BMD肌膜上nNOS缺乏或减少。nNOS参与调节肌肉的正常生理功能，其减少可能与DMD／BMD肌肉变性坏死有关。     

Duchenne型肌营养不良的临床和病理及抗肌萎缩蛋白表达

目的：归纳总结Duchenne型肌营养不良（DMD）的临床表现,组织病理特点及抗肌萎缩蛋白表达情况。方法：通过临床、病理及免疫组化染色方法,对16例DMD患者的临床表现,肌肉病理改变和肌肉抗肌萎缩蛋白表达情况进行观察分析。结果：年龄〉4岁的14例患儿均有比较典型的DMD临床表现;而年龄〈4岁的2例患儿症状较轻。肌肉病理显示2例为早期改变、11例为中期改变、3例为晚期改变,病理改变严重程度与年龄相关。免疫组化染色显示16例患者的肌肉标本抗肌萎缩蛋白均完全缺失。结论：DMD患者的临床和病理表现的严重程度与年龄有关,检查抗肌萎缩蛋白在肌纤维膜上表达是诊断DMD的金标准。     

Duchenne肌营养不良模型鼠基因型及肌肉病理的研究

目的研究Duchenne肌营养不良(DMD)模型鼠mdx基因型及肌肉病理改变。方法分别采用光镜、免疫荧光、EvansBlue染料、电镜等方法研究mdx小鼠与正常对照组C57/BL6小鼠腓肠肌病理改变,并检测mdx小鼠的基因型。结果经Dys-3、δ-sarcoglican抗体染色后mdx小鼠肌膜基本未见绿色荧光,正常对照组C57/BL6小鼠肌膜呈明显网状绿色荧光;荧光显微镜观察EvansBlue红色荧光染料,mdx小鼠肌纤维呈明显红色荧光,而肌膜完整的正常对照组C57/BL6小鼠肌纤维不摄取红色荧光染料。mdx模型鼠肌丝排列紊乱,方向不一,肌细胞核位于肌纤维中央,Z盘模糊,肌膜局部不连续,C57/BL6小鼠肌丝排列整齐,Z盘清晰可见。结论mdx小鼠以肌纤维变性、坏死为特征,肌细胞膜缺损是mdx小鼠主要病理改变之一。mdx小鼠dystrophin基因缺陷同时伴有dystrophin相关蛋白缺失,mdx小鼠肌肉病理为DMD进一步治疗研究奠定了基础。     

肌营养不良蛋白表达对肌营养不良症的诊断意义

目的：探讨肌营养不良蛋白在肌营养不良症患者肌组织中表达的意义。方法：运用免疫组化法对12例Duchenne型肌营养不良症（DMD）患者及5例Becker型肌营养不良症（BMD）患者的肌组织中肌营养不良蛋白的表达进行分析。并用6例非神经肌肉疾病患者的肌组织作为对照。结果：对照组6例肌组织标本中均可见肌营养不良蛋白表达,其阳性染色勾画出肌细胞的边界,胸及胞浆呈阴性。在DMD中有10例（83．33％）肌细胞膜肌营养不良蛋白不表达。BMD中3例（60）可见沿肌细胞膜分的不连续斑片状弱阳性染色。结论：肌营养不良蛋白的缺失或异常表达,是DMD／BMD型较为特异的改变。运用免疫组化法检测患者肌组织中肌营养不良蛋白的表达,可为DMD／BMD型的病理诊断提供特异指标。     

Exercise test in muscle channelopathies and other muscle disorders

We studied the percentage change in compound muscle action potential (CMAP) amplitude and area during and after a 5-min maximal contraction of the muscle. The exercise test (ET) was performed on 64 patients with different muscle disorders and on 46 normal controls. The range of normal ET values was defined as the mean + 2 SD of the control values. The mean sensitivity of the test was 63% in the whole group with ion channel muscle disorders, the highest sensitivity being seen in primary periodic paralysis (81%) and the lowest in chloride channelopathies (17%). In thyrotoxic periodic paralysis, the ET was abnormal in the three of the four patients studied. In patients with myotonic dystrophy, a smaller than normal increase in CMAP amplitude occurred during and after exercise, whereas in proximal myotonic myopathy a normal initial increase in CMAP amplitude was followed by an abnormal decrement. We conclude that the ET can be of use in confirming abnormal muscle membrane excitability in patients with calcium and sodium channelopathies and thyrotoxic periodic paralysis. In chloride channelopathy, the test may also be abnormal, but shows no, or only a small, increase in amplitude or area in the immediate postexercise period. The test may also be abnormal in proximal myotonic myopathy, but is normal in myotonic dystrophy.     

A case of sarcoid myopathy presenting muscle pain and muscle weakness and with muscle MRI abnormality]

We experienced a 70-year-old female diagnosed as sarcoidosis. She complained bilateral femoral pain from 70-year-old. 3 months after the onset, she developed muscle weakness extending to her upper extremities with high fever of 38-39 degrees C. The erythema appeared at the right femoral region 4 months after the onset. She admitted to our hospital because of further evaluation. When she was admitted, she had tenderness on grasping the femoral muscles, proximal limb muscle weakness and Gowers' sign. On laboratory examination, CRP, aldorase, myoglobin, lysozyme were increased mildly. The EMG demonstrated a myogenic pattern. Muscle biopsy performed from the left quadriceps femoris muscle revealed non-caseating granuloma and muscle fiber necrosis. A diagnosis of muscle sarcoidosis was made from the biopsy findings and the clinical features. With oral prednisolone administration, muscle weakness and other clinical features improved gradually. On muscle MRI, multiple small high intensity areas were scattered in the femoral muscles. Muscle MRI is considered to be useful for differential diagnosis of muscle sarcoidosis.     

Role of muscle spindle in weightlessness-induced amyotrophia and muscle pain

To date, the medium and long-term space flight is urgent in need and has become a major task of our manned space flight program. There is no doubt that medium and long-term space flight has serious damaging impact upon human physiological systems. For instance, atrophy of the lower limb anti-gravity muscle can be induced during the space flight. Muscle atrophy significantly affects the flight of astronauts in space. Most importantly, it influences the precise manipulation of the astronauts and their response capacity to emergencies on returning to the atmosphere from space. Muscle atrophy caused by weightlessness may also seriously disrupt the normal life and work of the astronauts during the re-adaptation period. Here we summarize the corresponding research concentrating on weightlessness-induced changes of muscular structure and function. By combining research on muscle pain, which is a common clinical pain disease, we further provide a hypothesis concerning a dynamic feedback model of “weightlessness condition ⇒ muscular atrophy ⇔ muscle pain”. This may be useful to explore the neural mechanisms underlying the occurrence and development of muscular atrophy and muscle pain, through the key study of muscle spindle, and furthermore provide more effective therapy for clinical treatment.     

The influence of muscle length on muscle fibre conduction velocity and development of muscle fatigue.

The influence of muscle (vastus lateralis) length on the muscle fibre conduction velocity (MFCV) and on muscle fatigue was studied in 8 healthy volunteers. In experiment 1, the electromyographic (EMG) responses were evoked by electrical stimulation of the motor point and recorded by a surface electrode array aligned along the muscle fibre direction. The MFCV (determined by cross-correlation) was measured at knee flexions of 5 degrees (full extension), 45 degrees, 90 degrees and 120 degrees with 3 different extension torques. The MFCV declined with increasing muscle length and increased with increasing background torque at knee flexions from 5 degrees to 90 degrees. From 90 degrees to 120 degrees knee flexion of MFCV tended to increase. In experiment 2, the EMG activity at a static fatiguing contraction (80% MVC) was measured at 45 degrees and 90 degrees knee flexion. The EMG was measured until the subject gave up contracting the muscle (endurance). The largest increase in the RMS amplitude and the fastest decreases in the mean power frequency (MPF) and MFCV were found at 90 degrees flexion. The MVC at 45 degrees knee flexion was 35% lower than at 90 degrees and the time until endurance was approximately twice as long for the 45 degrees contraction. The results indicate that muscle length is an important parameter for the propagation velocity of action potentials and for the development of static muscle fatigue.     

Relationship between muscle stress and intramuscular pressure during dynamic muscle contractions

Intramuscular pressure (IMP) has been used to estimate muscle stress indirectly. However, the ability of this technique to estimate muscle stress under dynamic conditions is poorly characterized. Therefore, the purpose of this study was to determine the extent to which IMP is a valid surrogate for muscle stress during dynamic contractions. IMP and muscle stress were compared under steady-state isotonic conditions and during complex dynamic length changes. During concentric contractions the shape of the IMP-velocity curve mimicked the basic shape of the force-velocity curve but with much higher variability. For eccentric contractions, a precipitous drop in IMP was observed despite increased muscle stress. The dissociation between muscle stress and IMP during dynamic contractions was partially explained by sensor movement. When the muscle was not moving, IMP explained 89% +/- 5% of the variance in muscle force. However, when transducer movement occurred the linear relationship between IMP and stress was no longer observed. These findings demonstrate the difficulty in interpreting IMP under dynamic conditions when sensor movement occurs. They also illustrate the need to control transducer movement if muscle stress is to be inferred from IMP measurements such as might be desired during clinical gait testing.     

Bradykinesia,muscle weakness and reduced muscle power in Parkinson's disease

Muscle power (force × velocity) could clarify the relationship between weakness and bradykinesia in Parkinson's disease (PD). The aims of this study were to determine if patients with PD were weaker and/or less powerful in their leg extensor muscles than a neurologically normal control group and to determine the relative contributions of force and movement velocity/bradykinesia to muscle power in PD. Forty patients with PD and 40 controls were assessed. Strength in Newtons (N) was measured as the heaviest load the participant could lift. Power in Watts (W) was measured by having the participant perform lifts as fast as possible. The PD group were 172 N weaker (95% CI 28–315) and 124 W less powerful at peak power (95% CI 32–216) than controls. However, velocity at maximal power was only reduced compared with controls when lifting light to medium loads. When lifting heavy loads bradykinesia was no longer apparent in the PD group. These results suggest that reduced muscle power in PD at lighter loads arises from weakness and bradykinesia combined, but at heavier loads arises only from weakness. The absence of bradykinesia in the PD group when lifting heavy loads warrants further investigation. © 2009 Movement Disorder Society