强直性肌营养不良临床表现、基因检测和骨骼肌活检特点分析

目的 探讨强直性肌营养不良临床表现、基因检测及骨骼肌活检特征。方法 回顾性分析我中心25例强直性肌营养不良（myotonic dystrophies,DMs）患者临床资料、分子检测及骨骼肌活检结果,为临床诊断提供科学依据。结果 25例患者经（CTG）n/（CCTG）n分子检测,22例诊断为强直性肌营养不良Ⅰ型（myotonic dystrophies1,DM1）,3例诊断为强直性肌营养不良Ⅱ型（myotonic dystrophiesⅡ,DM2）。25例DMs均呈典型肌强直电位,15例合并肌病电位。22例DM1四肢远端肌肌强直、肌萎缩、肌无力伴心脏、生殖等系统受累;3例DM2四肢近端肌伴心脏受累,余无异常。骨骼肌活检：25例DMs均可见典型中心核、核内移、核聚集,肌浆块;22例DM1 ATP酶染色呈典型Ⅰ型肌纤维萎缩为主,Ⅱ型肌纤维肌源性优势/群化,部分病例表现为部分肌纤维变性、坏死,偶见再生肌纤维,结缔组织中至重度增生,氧化酶活性局灶降低,可见虫噬、轴空样改变;3例DM2 ATP酶染色呈典型Ⅱ型肌纤维萎缩为主,Ⅰ型肌纤维优势,伴轻度肌纤维变性、坏死,结缔组织轻度增生。结论 分子生物学...     

Ⅱ型糖原累积病的临床与病理分析

目的 分析Ⅱ型糖原累积病临床与骨骼肌病理特点.方法 对1例肌无力、肌张力减低患儿,行开放式骨骼肌活检、组织化学染色病理及临床分析.结果 除骨骼肌病变外,心脏、肝脏、脾脏多脏器受累.骨骼肌特征性病理改变:大量肌纤维胞浆内可见大小不均空泡,内有糖原堆积;酸性磷酸酶活性显著增高,空泡内未见脂滴颗粒.结论 Ⅱ型糖原累积病是累及全身多脏器的代谢性肌病.骨骼肌活检病理诊断是肌糖原累积病的确诊手段.     

dysferlinopathy患者40例临床和病理分析

目的 回顾性分析40例dysferlinopathy患者临床及活检骨骼肌组织化学、免疫组织化学染色病理变化,探讨dysferlinopathy的临床、病理诊断价值.方法 对40例dysferlinopathy患者临床资料进行分析;并对活检骨骼肌进行组织化学、免疫组织化学染色病理分析.结果 患者一般临床表现:进行性加重的肌无力、萎缩;根据病初受累肌群分为:肢带型肌营养不良2B型27例,Miyoshi远端型肌营养不良12例,以及胫骨前肌起病的远端肌病1例;血肌酸激酶水平呈不同程度的升高(134～ 19 795 U/L);全部患者肌电图呈肌源性损害;12例行骨骼肌MRI,其中9例行双侧大、小腿MRI检查,3例行双侧小腿MRI检查;近端肌受累为主4例、腓肠肌受累为主7例、胫骨前肌受累为主1例.骨骼肌活检组织化学染色病理表现:肌纤维变性、坏死和再生活跃,结缔组织不同程度增生,16例可见肌内膜、肌束膜和小血管周围炎性细胞浸润;抗-dysferlin单克隆抗体免疫组织化学染色结果显示,30例dysferlinopathy患者肌纤维膜上dysferlin蛋白完全缺失,10例重度减低.结论 本病典型临床表现为进行性加重肌无力、肌萎缩,根据病初受累肌群区分临床表型;血肌酸激酶显著增高,符合膜蛋白破坏型肌营养不良特点;骨骼肌MRI可清晰判断受累肌群范围、程度,帮助判断临床表型及选择合适的骨骼肌活检部位;病理特点为肌营养不良改变,部分患者有炎性细胞浸润,需要结合临床与炎性肌病相鉴别;肌纤维膜dysferlin蛋白缺失或重度减低,是dysferlinopathy分子病理诊断的重要依据.     

中央轴空病2例临床及病理分析

目的 探讨中央轴空病的临床及病理特点.方法 开放式骨骼肌活检,组织化学染色,病理分析.结果 细胞色素C氧化酶、琥珀酸脱氢酶、还原型辅酶Ⅰ、单磷酸腺苷脱氨酶染色,大量肌纤维中均可见中央轴空现象,ATPase染色(酸性、碱性)肌纤维类型分布异常,几乎全部为Ⅰ型肌纤维.结论中央轴空现象是中央轴空病的特征性病理改变,可合并单一Ⅰ型肌纤维肌病;骨骼肌活检、病理检查是确诊本病的重要手段.     

PTMG大鼠模型眼外肌受累证据的研究

目的探讨被动转移重症肌无力(PTMG)大鼠模型眼外肌的受累情况。方法腹腔注射mAb35建立SD大鼠PTMG模型并观察其眼部症状,取大鼠眼外肌(EOM)行HE染色、琥珀酸脱氢酶染色、免疫组化以及置透射电镜下观察EOM神经-肌肉接头(NMJ)处病理变化,并与生理盐水对照组比较。结果 PTMG大鼠出现睑裂缩小和眼球内陷充血、眼部流出血性分泌物的现象;HE染色显示出现眼部症状的PTMG大鼠EOM肌纤维轻度萎缩,肌细胞周围间质有较多淋巴细胞浸润;与对照组比较,琥珀酸脱氢酶染色显示PTMG组大鼠EOMⅠ型肌纤维比例下降,ⅡA型肌纤维比例上升;免疫组化显示PTMG大鼠EOM上可与银环蛇毒结合的乙酰胆碱受体数量显著减少;透射电镜发现PTMG组大鼠EOM出现NMJ突触皱褶短缩,皱褶数量减少等类似重症肌无力的病理改变。结论 PTMG大鼠EOM确有受累并出现重症肌无力典型病理变化,可为进一步在此模型上研究EOM易感机制提供实验基础。     

脂质沉积病1例临床与病理报告

脂质沉积病１例临床与病理报告高凤琴，江新梅，林世和本文报告一中年女性脂质沉积病，肌活检示肌纤维中有大量脂肪颗粒沉积，以Ｉ型肌纤维受累为主。经大剂量强的松顿服、辅酶Ｑ１０及低脂饮食治疗，病情好转恢复正常。患者女性，３８岁，会计。因四肢无力２年，逐渐加重...     

脂质沉积性肌病的临床及病理学特点

目的探讨脂质沉积性肌病(LSM)的临床及病理学特点。方法对14例LSM患者的临床及骨骼肌病理资料进行分析。结果14例LSM患者的主要临床表现为以近端肌无力起病,渐累及全身,其中13例四肢受累,1例双下肢受累,2例颈肌受累,伴肌痛2例、肌萎缩3例;血清肌酸激酶正常5例,不同程度增高9例;14例肌电图均呈肌源性损害;14例骨骼肌病理检查(HE、MGT染色)可见大量肌纤维胞浆内散在空泡,油红"O"染色空泡红染;透射电镜分析可见沿肌纤维长轴散在串珠样膜性空泡结构。结论LSM临床表现为非特异性肌无力;肌纤维内脂质沉积是LSM主要病理表现;骨骼肌病理检查是确诊LSM的可靠方法。     

主要组织相容性复合物Ⅰ类抗原在特发性炎性肌病中的表达研究

目的 探讨主要组织相容性复合物Ⅰ类抗原(MHC-Ⅰ)在特发性炎性肌病(IIM)中的表达及其意义.方法 对15例IIM患者(IIM组,多发性肌炎14例、皮肌炎1例)、23例其他肌病患者(OM组,肢带型肌营养不良18例、脂质沉积性肌病4例、糖原累积性肌病1例)及5例无肌病对照者(NC组)的骨骼肌标本进行MHC-Ⅰ免疫组化染色.结果 NC组未见MHC-Ⅰ表达;IIM组肌纤维MHC-Ⅰ阳性率为86.7%(13/15),明显高于OM组(26.1%,6/23)(P<0.005).IIM组MHC-Ⅰ阳性表达的敏感性为86.7%,95%CI:59%～98%;特异性为73.9%,95%CI:55%～91%.结论 IIM患者肌纤维MHC-Ⅰ阳性表达高.MHC-Ⅰ免疫组化染色是一种较好的辅助IIM病理诊断的方法.     

强直性肌营养不良Ⅰ型临床、病理、骨骼肌磁共振特点

目的总结11例强直性肌营养不良Ⅰ型(DM1)患者的临床、病理和双下肢肌肉受累的特点。方法回顾性分析2012年01月至2020年10月就诊于南京鼓楼医院神经内科的11例DM1患者的临床、骨骼肌活检病理及5例双下肢骨骼肌磁共振的特点。结果11例患者均有不同程度的肌强直、伴有肌无力/肌萎缩症状,肌无力/肌萎缩远端重于近端。骨骼肌病理特点:10/11例患者可见Ⅰ型肌纤维轻度萎缩,部分患者可见核内移、核聚集、肌浆块现象。双下肢肌肉磁共振:5例患者双下肢远端脂肪浸润重于近端,双侧肌肉受累程度不对称,大腿肌肉脂肪浸润以股中间肌最严重,小腿肌肉以腓肠肌、比目鱼肌、腓骨长肌最严重。结论骨骼肌磁共振对诊断强直性肌营养不良Ⅰ型有重要的提示意义。     

脂质沉积性肌病

脂质沉积性肌病是先天性脂质代谢障碍,致脂质沉积在肌纤维中而引起的一组肌病。肌活检示肌纤维中有大量脂肪颗粒沉积,以Ⅰ型肌纤维受累为重。经低脂饮食及药物治疗,病情可控制。本文对该病的发病机制,临床表现,肌电图,肌肉病理特点,诊断,鉴别诊断及治疗等作一综述。     

类固醇肌病的临床和病理特点分析（附10例报道）

目的：探讨类固醇肌病的临床和病理特点。方法：收集2007至2011年收治的10例有使用糖皮质激素史,并经肌肉活检病理证实的类固醇肌病患者的临床资料,分析并总结其临床和病理特点。结果：10例类固醇肌病患者中女性6例、男性4例,年龄14~79（51.1±18.5）岁。使用激素后至起病时间为7 d至14个月。所有病例均表现为四肢近端无力,股四头肌均呈不同程度萎缩,7例以双下肢近端受累为主,3例同时有上臂肌群萎缩;血清肌酸激酶（CK）和CK-mb均正常,9例乳酸脱氢酶（LDH）值高于正常上限;肌电图示轻度肌源性损害;肌肉活检均可见肌纤维大小不一;酶学染色提示：Ⅱ型纤维选择性萎缩。结论：类固醇肌病好发于中老年人群,多在使用糖皮质激素数周至数月后发生,肌无力和肌萎缩以下肢近端为主,血清CK基本正常,LDH轻度增高,肌肉病理示选择性Ⅱ型纤维萎缩为其病理特点。     

Preventive effects of insulinlike growth factor-I on steroid-induced muscle atrophy

We examined the effects of simultaneous administration of recombinant insulinlike growth factor-I (IGF-I) and glucocorticoid on the diameter of muscle fibers in rats. The steroid group received subcutaneous injection of triamcinolone, the IGF-treated group received IGF-I alone, and the steroid plus IGF group received both triamcinolone and IGF-I. After 14 days, each rat was subjected to muscle biopsy of the extensor digitorum longus and soleus. Glucocorticoid treatment caused significant reduction in diameter of muscle fibers, compared to controls. Simultaneous administration of IGF-I significantly attenuated glucocorticoid-induced muscle atrophy. Glucocorticoid increased both urinary concentration of 3-methylhistidine and urinary creatine/creatinine ratio. IGF-I reduced those changes in the urine. We conclude that IGF-I administration prevents, at least partially, the development of steroid myopathy.     

Nonaka肌病伴面部肌肉受累

目的 报道1个伴随面部肌肉受累及的Nonaka型远端性肌肉病家系的临床和病理特点，讨论其发病机制。方法 先证者在中年早期起病。主要临床表现为胫前肌为主的四肢远端肌无力和肌萎缩，伴随有面肌和胸锁乳突肌力弱以及眼睑下垂，股四头肌不受累。肌酶轻度升高。肌电图提示肌源性损害。对患者进行胫前肌活检，进行组织学，酶组织化学和超微结构检查。家族中其妹妹也具有相同的临床表现。出现下肢远端为主的肌无力和肌萎缩。结果 肌肉病理改变特点是出现肌纤维肥大和萎缩。伴随核内移和肌纤维分裂现象。在部分肌纤维内可见镶边空泡和胞浆体。电镜下可见肌纤维内和核内的管丝包涵体以及髓样小体，其中出现在膜下的管丝包涵体具有细胞核的轮廓，可以看到细胞核变性后形成致密破碎结构。结论 结合患者的家庭史，临床表现和病理学改变特点。此患者可以考虑为Nonaka肌病，我们证实此病可以伴随面部肌肉的受累及。其发病机制可能与肌核的变性有关。     

Branched‐chain amino acids protect against dexamethasone‐induced soleus muscle atrophy in rats

We investigated the utility of branched‐chain amino acids (BCAA) in dexamethasone‐induced muscle atrophy. Dexamethasone (600 μg/kg, intraperitoneally) and/or BCAA (600 mg/kg, orally) were administered for 5 days in rats, and the effect of BCAA on dexamethasone‐induced muscle atrophy was evaluated. Dexamethasone decreased total protein concentration of rat soleus muscles. Concomitant administration of BCAA reversed the decrease. Dexamethasone decreased mean cross‐sectional area of soleus muscle fibers, which was reversed by BCAA. Dexamethasone increased atrogin‐1 expression, which has been reported to play a pivotal role in muscle atrophy. The increased expression of atrogin‐1 mRNA was significantly attenuated by BCAA. Furthermore, dexamethasone‐induced conversion from microtubule‐associated protein 1 light chain 3 (LC3)‐I to LC3‐II, which is an indicator of autophagy, was blocked by BCAA. These findings suggest that BCAA decreased protein breakdown to prevent muscle atrophy. BCAA administration appears to be useful for prevention of steroid myopathy. Muscle Nerve, 2010     

Endocrine myopathies

The atrophy produced by endocrine disorders is primarily due to alterations in protein and carbohydrate metabolism. Type II muscle fibers are more severely affected than are Type I fibers. Steroid myopathy and the myopathy associated with excess ACTH have a typical pattern of proximal weakness affecting the legs more than the arms. Steroid myopathy is usually not apparent until other signs of glucocorticoid excess are present. Treatments of steroid myopathy are as follows: Lower the dose of steroid, use a nonfluorinated glucocorticoid, and exercise or physical therapy. Adrenal insufficiency produces generalized weakness, muscle cramping, and fatigue in 50 per cent of patients. Some patients also develop hyperkalemic paralysis. The treatment is hormone replacement. Thyrotoxicosis produces myopathy caused by net protein catabolism, accelerated basal metabolic rate and impaired carbohydrate metabolism. Shortening of contraction time may result from accelerated myosin ATPase activity and enhanced calcium uptake by the sarcoplasmic reticulum. Depolarization of the muscle fiber and impaired Na-K activity in muscle may predispose to thyrotoxic periodic paralysis. Neuromuscular presynaptic impairment may account for the worsening of myasthenia gravis by thyrotoxicosis. In hypothyroidism, impaired energy metabolism may limit force generation. Slow contraction and relaxation reflect reduction in myosin ATPase activity and impaired calcium uptake by the sarcoplasmic reticulum. Treatment for thyroid-associated muscle disorders is restoration of a euthyroid state. Muscle weakness associated with hypopituitarism is due to loss of thyroid and adrenal cortical hormones. Children require growth hormone for muscle development. T3 and growth hormone synergize to maintain normal protein synthesis. Primary and secondary hyperparathyroidism and osteomalacia are often associated with proximal weakness and fatigability. The myopathy improves with restoration of normal PTH levels and vitamin D replacement. Hypoparathyroidism and pseudohypothyroidism are associated with tetany. Tetany is worsened by alkalosis and is treated by calcium and magnesium replacement.     

眼咽远端型肌病一家系的咽喉功能观察以及骨骼肌病理特点

目的 报道1个眼咽远端型肌病家系的病理和电生理改变特点,分析其吞咽功能障碍的变化规律.方法 先证者为24岁女性,出现进行性加重的眼外肌麻痹、吞咽困难、构音障碍及四肢远端无力和萎缩2年.肌酸激酶轻度升高.家族同代人中还有5例在20～30岁出现类似症状.对先证者进行纤维咽喉镜吞咽功能检查和肌电图检查,对胫前肌进行肌肉病理检查.结果 纤维咽喉镜检查发现软腭上抬差,肌电图检查发现胫前肌呈现肌源性损害伴随肌强直现象.肌肉病理改变特点是肌纤维出现肥大、萎缩、间质纤维化,部分肌纤维内可见镶边空泡,电镜检查显示肌纤维的胞质内存在管丝包涵体.结论 临床和病理检查证实眼咽远端型肌病的存在,软腭运动障碍是出现咽喉症状的主要原因,此病存在肌强直的电生理改变特点.     

The significance of type 1 fiber atrophy (hypotrophy) in childhood neuromuscular disorders

To determine the incidence of selective type 1 fiber atrophy (hypotrophy) and its possible significance in various muscle diseases of childhood, we reviewed 2212 muscle biopsies from children which we had examined in the past 20 years histochemically with ATPase staining. Type 1 fiber atrophy was seen in a variety of neuromuscular disorders, but predominantly in congenital myopathies, including all patients with congenital fiber type disproportion myopathy (20 patients), central core disease (12 patients) and multicore disease (four patients). Although type 1 fiber atrophy was not a constant feature in nemaline myopathy and myotubular myopathy, all patients with these diseases had abnormal fiber type distribution which included type 1 fiber predominance both with and without type 2B fiber deficiency. Together with abnormal fiber type distribution, type 1 fiber atrophy was a common finding in childhood neuromuscular disorders, especially congenital myopathies.     

The role of proteases in experimental glucocorticoid myopathy

Mature, male, New Zealand white rabbits were treated with the synthetic glucocorticoid betamethasone (0.3 mg/kg body weight/day) for 2 weeks. The glucocorticoid treatment caused a 30% decrease in muscle weight of the type 2 psoas muscle, but had no apparent effect on the type 1 soleus muscle. Cathepsin D activity was elevated twofold in the psoas muscle of treated rabbits, a finding suggesting an active role for lysosomes in mediating muscle breakdown in glucocorticoid-induced myopathy of the rabbit. There was no detectable alkaline serine protease activity in the muscles from either treated or control rabbits. Alkaline protease is localized in mast cells in some species, particularly the rat. Toluidine blue staining for mast cells was absent in rabbit muscles, a finding indicating that this species does not contain these cells. This protease, previously implicated in glucocorticoid myopathy, apparently plays no role in rabbit myopathy. There was no detectable elevation of the Ca-activated protease in muscles from glucocorticoid-treated animals. This finding suggests that if this protease plays a role in muscle degradation, its activity is controlled in vivo by special conditions (such as elevated CA levels, inhibitors, and compartmentalizations).     

Role of ubiquitin–proteasome proteolysis in muscle fiber destruction in experimental chloroquine‐induced myopathy

Previous studies have documented the presence of rimmed vacuoles, atrophic fibers, and increased lysosomal cathepsin activity in skeletal muscle from animal models of chloroquine‐induced myopathy, suggesting that muscle fibers in this type of myopathy may be degraded via the lysosomal‐proteolysis pathway. Given recent evidence of abnormal ubiquitin accumulation in rimmed vacuoles, in this study we chose to examine the significance of the ubiquitin–proteasome proteolytic system in the process of muscle fiber destruction in experimental chloroquine myopathy. Expression of ubiquitin, 26S proteasome proteins, and ubiquitin ligases, such as muscle‐specific RING finger‐1 (MuRF‐1) and atrogin‐1/muscle atrophy F‐box protein (MAFbx), was analyzed in innervated and denervated rat soleus muscles after treatment with either saline or chloroquine. Abnormal accumulation of rimmed vacuoles was observed only in chloroquine‐treated denervated muscles. Ubiquitin and proteasome immunostaining, and ubiquitin, MuRF‐1, and atrogin‐1/MAFbx mRNAs were significantly increased in denervated soleus muscles from saline‐ and chloroquine‐treated rats when compared with contralateral innervated muscles. Further, ubiquitin and ubiquitin ligase mRNA levels were higher in denervated muscles from chloroquine‐treated rats when compared with saline‐treated rats. These data demonstrate increased proteasomes and ubiquitin in denervated muscles from chloroquine‐treated rats and suggest that the ubiquitin–proteasome proteolysis pathway as well as the lysosomal‐proteolysis pathway mediate muscle fiber destruction in experimental chloroquine myopathy. Muscle Nerve 39: 521–528, 2009