线粒体肌病与线粒体脑肌病的酶组织化学和超微结构改变

目的：探讨原发性线粒体肌病与脑肌病的病理特征及临床特点。方法：对11例原发性线粒体肌病与脑肌病患者的临床表现，酶组织化学及超微结构进行分析，结果：11例MGT染色均发现有不整红边纤维（RRF），其中单纯表现为肌无力的患者7例，合并中构神经系统受累者4例，RRF出现比例为6．4％－10．3％，电镜观察11例，9例表现为线粒体数目增多，形态异常，嵴排列紊乱等。均可见线粒体内类结晶状包涵体。2例线粒体改变只见数量增多，未见其他异常。结论：光镜下酶组化染色发现典型RRF，对线粒体肌病与脑肌病的初步论断有重要价值。电镜观察肌膜下线粒体异常增多且形态异常，特别是线粒体内类结晶状包涵体的出现，对本病的确诊有重要意义。     

线粒体肌病和线粒体脑肌病组织化学及电镜的研究

本文报告了2例线粒体肌病、3例线粒体脑肌病(MALES1例、MER-RF2例)。所有病例的速冻连续切片的GT染色均见有RRF。在HE—NADH—TR、ATP酶、PAS、、磷酸化酶及SND染色中均见有RRF样增强纤维。细胞色素C氧化酶染色中有2例的切片出现阴性染色肌纤维、考虑为复合体Ⅳ活性低下,余3例染色正常。电镜下观察到除有大量形态异常的线粒体外,并在这些线粒体内见有结晶状、板层状及同心圆样的包涵体。     

线粒体肌病与其它神经肌病破碎红纤维的对比研究

为了探讨破碎红纤维（ＲＲＦｓ）对线粒体肌病的诊断价值，对线粒体肌病、多发性肌炎／皮肌炎（ＰＭ／ＤＭ）和脊髓性肌萎缩（ＳＭＡ）３组病人ＲＲＦｓ的形态特点和出现频率进行了对比研究，同时对３组病人线粒体的超微结构改变进行了对比观察。结果发现总ＲＲＦｓ出现频率线粒体肌病组３．０％～１５．２％，ＰＭ／ＤＭ组５．２％～１１．１％，ＳＭＡ组４．５％～４９％。线粒体肌病组以典型ＲＲＦｓ为主，ＰＭ／ＤＭ组以均匀红染纤维为主，ＳＭＡ组以红边纤维为主。线粒体的超微结构观察发现线粒体肌病组线粒体形态改变、嵴排列异常及嵴内包涵体多见，受累线粒体较多。ＰＭ／ＤＭ组和ＳＭＡ组线粒体主要改变是数量增多，形态变小，而外形改变和嵴排列异常少见。未见嵴内包涵体。本研究结果提示ＲＲＦｓ及出现频率不能作为诊断线粒体肌病的形态学标准，典型ＲＲＦｓ对线粒体肌病的诊断较有价值。电镜观察线粒体超微结构改变的不同特点有助于线粒体肌病的鉴别诊断     

慢性进行性眼外肌瘫痪型线粒体肌病(附3个家系报告)

目的 探讨家族性慢性进行性眼外肌瘫痪（CPEO）型线粒体肌病的临床、遗传和病理特点。方法 回顾性分析CPEO型线粒体肌病3个家系21例患者的临床表现、家系调查及5例肌活检病理学资料。结果 患者临床均表现为眼睑下垂和眼球运动障碍,伴或不伴有肌无力。1家系符合常染色体显性遗传规律,另2个家系符合母系遗传规律。病理改变：光镜下为破碎红纤维（RRFs）和细胞色素C氧化酶（COX）缺失纤维;电镜为肌膜下、肌原纤维间线粒体数量增多,嵴内可见电子致密颗粒或晶格样包涵体。结论 3个家系及其亲子代问临床与病理表现相似,提示不同遗传方式所致CPEO型线粒体肌病临床表现是相同的。     

成人发病的肌原纤维肌病的临床和病理学特征(附2例报告)

目的 探讨成人发病的肌原纤维肌病的临床和病理学特征.方法 回顾性分析2例成年发病的肌原纤维肌病患者的临床资料.结果 2例患者表现为近端或远近端肌肉无力,进行性加重.光镜下可见肌纤维内和肌膜下颗粒样或团块样物质沉积,免疫组化为结蛋白.电镜发现1例肌膜下及肌原纤维间存在大小不一的包涵体,另1例肌原纤维排列紊乱,Z线不规则样增粗.常见突变基因检测未见异常.结论 成人发病的肌原纤维肌病临床无特异性表现,其病理学特征为肌纤维内可见异常物质沉积,电镜发现肌原纤维间包涵体结构或Z线异常.     

多种形态类结晶包涵体并存的线粒体肌病1例报告

线粒体肌病是一组由于线粒体遗传基因缺陷而导致的以线粒体功能障碍为主要特征的肌病，目前认为，肌纤维内线粒体类结晶包涵体的存在对诊断该病具有重要意义。本文报告1例线粒体肌病患者，发现超微病理表现丰富,特别是线粒体内类结晶包涵体形态、数目之异常，不同于以往国内、外报告的特征，现报告如下。     

线粒体脑肌病的临床与病理

目的探讨线粒体脑肌病的临床与肌肉病理特点。方法对16例肌活检证实的线粒体脑肌病病例的临床表现、肌肉组织化学及超微结构进行分析。结果16例患者破碎红纤维(RRF)的平均比例为5.9%,11例有中央核增多,13例的SDH/CCO双染示12例有蓝纤维,且与RRF的分布一致。超微结构观察有4例找到典型晶格状包涵体。结论SDH/CCO双染有蓝纤维为线粒体肌病的诊断提供了依据,借此可与其他肌病鉴别。     

线粒体胃肠肌病二例的临床与病理研究

目的 报道2例以胃肠道功能异常和肌无力为主要表现的线粒体病，探讨本病的诊断规律。方法 2例男性患者分别为13岁和6岁，在6岁和4岁5个月时起反复出现胃肠道症状和持续性肌无力，无眼外肌瘫痪和中枢神经系统损害的表现，头颅CT和MRI检查无异常，对2例患者进行肌肉活检和线粒体基因检查。结果 肌肉活检证实2例患者的骨骼肌存在大量典型的不整红边纤维和琥珀酸脱氢酶深染的肌纤维，肌纤维内糖原和脂肪滴增多。电镜检查显示肌纤维内出现大量巨大线粒体，部分线粒体内出现环状排列的嵴或类结晶包涵体，肌纤维内糖原和脂肪滴增多。基因检查示2例患者分别存在线粒体基因3243点突变和3271点突变。结论 胃肠道功能异常和肌无力可以作为主要临床症状组合出现在线粒体病中，由于2例患者的临床表现不同于以前报道的线粒体脑肌病，应诊断为线粒体胃肠肌病，可能属于线粒体病一个新的临床病理亚型。在寻找儿童慢性胃肠功能异常的病因时应考虑到本病的可能。     

青年脑出血与线粒体脑肌病的关系

目的 研究青年脑出血与线粒体脑肌病(MEM)的关系。方法 对4例与线粒体脑肌病有关的青年脑出血患者的肌活检标本进行电镜观察、Gomori组化染色、血乳酸测定及肌电图检测。结果 4例青年脑出血患者的肌活检标本均可见不整红边纤维(RRF)，血乳酸值增高，线粒体形态异常。结论 提示部分青年脑出血患者发病与MEM有关。     

线粒体肌病及脑肌病的PGA标记法免疫电镜研究

检测线粒体肌病及脑肌病时线粒体嵴上的酶复合体Ⅰ、Ⅱ、Ⅲ、Ⅳ含量，以探讨其发病机理。用９例线粒体肌病及脑肌病患者和３例正常人的肌肉组织进行蛋白Ａ胶体金法（ＰＧＡ）标记后，在电镜下定量分析比较。结果表明：患者肌肉组织中线粒体内与ＰＧＡ结合的酶复合体Ⅰ、Ⅱ、Ⅲ、Ⅳ金粒子均有程度不同的减少，尤其是在ＣＣＯ染色呈阴性的患者肌肉组织中与酶复合体Ⅳ结合的金粒子减少更为显著。作者认为：线粒体肌病及线粒体脑肌病时患者肌肉组织线粒体内酶复合体Ⅰ、Ⅱ、Ⅲ、Ⅳ活性均降低，尤其是在ＣＣＯ染色呈阴性者中酶复合体Ⅳ活性减少更为明显。线粒体内酶复合体活性降低对本病的发生至为重要。     

Immaturity of muscle fibers in the congenital form of myotonic dystrophy: its consequences and its origin

Skeletal muscle maturation is impaired in children with congenital myotonic dystrophy. This immaturity is characterized at the light microscopy level by an abnormal presence of myotubes, small fascicles of muscle fibers, thin myofibers, and delayed muscle fiber type differentiation with a peripheral halo lacking mitochondrial oxidative enzyme activity. At an ultrastructural level, the characteristics are a paucity of myofibrils with a peripheral rim devoid of mitochondria and myofibrils in the fibers. In time the muscle is able to gain a certain degree of maturity as shown in one of our cases who had two successive muscle biopsies. The muscle, however, never becomes normal but retains discrepancies in fiber size and fiber type distribution and shows some fiber necrosis. Maturation of the motoneurons is normal, which may explain necrosis of immature muscle fibers. In an experimental study carried out to look for evidence of a circulatory factor in mothers of children with congenital myotonic dystrophy, it was found that sera from these mothers administered intra-peritoneally to newborn rats does in fact impair muscle maturation, whereas rats injected similarly with sera from control women showed normal muscle maturation.     

脂质沉积性肌病的电镜诊断

目的脂质沉积性肌病是神经内科一种少见肌病，观察脂质沉积性肌病的超微结构特点，探讨电镜检查对脂质沉积性肌病的诊断价值及其与线粒体病的关系。方法对7例临床上出现肌无力的患者进行肌肉活检，取股四头肌或腓肠肌进行常规电镜标本制备，半薄切片甲苯胺蓝染色选取部位后进行超薄切片，铅、铀染色后透射电镜观察、分析。结果所有患者的肌肉活检均显示肌纤维内出现大量的脂滴，脂滴排列密集，呈串珠状分布在残存的肌丝间，存在明显脂滴融合现象。1例线粒体明显异常，出现明显的结晶样包涵体。毛细血管内皮细胞内和成纤维细胞的胞质内也能发现脂滴。1例有明显神经痛，电镜检查发现外周神经髓鞘板层分离，雪旺氏（Schwann）细胞内出现脂滴沉积。1例间质有胶原纤维增生，并可见再生肌纤维。结论脂质沉积性肌病是一组有独特超微结构特点的肌病，与线粒体异常有一定关系，电镜检查有助于该病的确诊。     

The Kearns-Shy syndrome. A multisystem disease with mitochondrial abnormality demonstrated in skeletal muscle and skin

An 11-year-old girl presented with external ophthalmoplegia and lid ptosis, pigmentary degeneration of the retina, complete heart block, skeletal muscle weakness, cerebellar deficit, stunted physical growth, fatigue and some mental subnormality. Total protein and IgM, IgA and IgG immunoglobulins were increased in the cerebrospinal fluid. Histochemical studies on the gastrocnemius and quadriceps muscle biopsies revealed many abnormal histochemical type I fibres in which excessive amounts of granular material having strong oxidative enzyme activity were prominent. On electron microscopy these muscle cells contained clusters of many abnormally large mitochondria in which the normal arrangement of the cristae was disturbed, the matrix was increased and sometimes contained dense deposits, and crystalloids were present in the intracristal space. Analogous mitochondrial abnormalities were present in many secretory cells of eccrine sweat glands in a skin biopsy. In skeletal muscle excessive lipid droplets (presumably glycerides) were present close to the abnormal mitochondria. Many patients exhibiting the main clinical and laboratory features of our patient have been recognized and reported in the literature. A clinically identifiable entity emerges which we propose to designate the Kearns-Shy syndrome. While the described mitochondrial abnormalities in muscle cells are not found only in this syndrome, their demonstration is useful in confirmation of the diagnosis, since they have been observed in all cases of the syndrome where muscle biopsies were studied by histochemistry and electron microscopy. Mitochondrial alterations have also been reported in liver cells, cerebellar cortical cells and extraocular muscle fibres. The relationship between the mitochondrial abnormalities and the disturbed tissue function remains obscure. The aetiology of this disorder is unknown; there has been no documented familial occurrence to suggest a genetically determined process.     

Endothelial ultrastructural alterations of intramuscular capillaries in infantile mitochondrial cytopathies: “Mitochondrial angiopathy”

Electron microscopy (EM) is a reliable method for diagnosing mitochondrial diseases in striated muscle biopsy in infancy. Ultrastructural alterations in mitochondria of myofibers are well documented, but there are few studies of endothelial involvement in intramuscular capillaries. Quadriceps femoris biopsies of five representative infants and toddlers, ages neonate to 3.5 years, were performed because of clinical and laboratory data consistent with mitochondrial disease without mitochondrial DNA (mtDNA) mutations and likely with nuclear DNA mutations. Pathological studies included histochemistry, EM, respiratory chain enzymatic assay and mtDNA sequencing and deletion/duplication analysis. EM demonstrated frequent and severe alterations of mitochondria in capillary endothelium. The most constant changes included: either too few or fragmented cristae; stacked and whorled cristae; paracrystallin structures that often were large and spheroid with stress fractures; closely apposed membranes of granular endoplasmic reticulum surrounding mitochondria with loss of the normal intervening layer of cytoplasm; long narrow, thin looped microvilli extending into the lumen; and thick microvilli containing large, abnormal mitochondria. We conclude that mitochondrial cytopathies in early life exhibit more severe ultrastructural alterations in the endothelium than in myofibers and that paracrystallin body structure differs, perhaps due to less rigid surrounding structures. This distribution may explain the frequent lack of prominent histochemical and biochemical abnormalities in muscle biopsies of young patients. Endothelial changes do not distinguish the genetic defects. Vascular involvement in brain contributes to cerebral lesions and neuronal death by impairment of molecular and nutrient transport and ischemia; endothelium in muscle may reflect similar changes.     

Origin of the ring muscle fibers in neuromuscular diseases.

Morphological histochemical and ultrastructural examination of the ring fibers in one case of myotonic dystrophy and one case of mitochondrial myopathy provides evidence that the ring fibers develop in the course of fiber splitting and reinnervation of muscle fiber fragments. The reinnervation may have been due to a neurogenic lesion coexisting in both cases with the myopathic picture. The histologically different type of annular myofibrils observed in one case of cap disease is probably due to delayed embryonic development and abnormal relations between the myofibrils and elements of the cytoskeleton.     

Fatal infantile mitochondrial myopathy due to cytochrome c oxidase deficiency

A case of cytochrome c oxidase deficiency primarily affecting skeletal muscle is described. The child was admitted at 4 weeks due to failure to thrive and examination at that time revealed weakness and hypotonia. His condition deteriorated until at 11 weeks respiratory arrest necessitated artificial ventilation and death occurred at 14 weeks. Biochemical investigation showed lactic acidaemia and generalised aminoaciduria. Histochemical examination of muscle obtained at biopsy showed strong reactions for some oxidative enzymes, but by contrast cytochrome c oxidase could not be detected. Cytochrome c oxidase activity was less than 5% of control values in an extract of fresh muscle. The reduced-minus oxidised absorption spectra of muscle mitochondrial fractions prepared from postmortem tissue showed an absence of cytochrome aa₃ and a partial deficiency of cytochrome b. Ultra-structural examination showed abnormal mitochondria with loss of cristae and an abnormal granular matrix. The family history suggests autosomal recessive inheritance.     

Pathological Findings of the Sural Nerve in Mitochondrial Encephalomyopathy

Abstract: We examined the muscle and peripheral nerve of a 55–year-old woman with familial mitochondrial encephalomyopathy. In the gastrocnemius muscle, many ragged red fibers and mitochondria containing paracrystalline inclusions in those fibers were observed by light and electron microscopy, respectively. Histopathological studies of the sural nerve revealed a marked decrease in the number of large myelinated fibers. Electron microscopic studies showed an accumulation of glycogen particles and mitochondria containing abnormal, structurally obscure cristae in the Schwann cell cytoplasm. These results suggest that the cause of loss of the large myelinated fibers may be some disturbance of metabolism in the Schwann cells due to mitochondrial dysfunction.     

Involvement of extraocular muscle in mitochondrial encephalomyopathy

Summary We carried out a histological examination of the extraocular muscles (EOMs) in a case of myoclonus epilepsy associated with ragged-red fibers (MERRF) and two cases of mitochondrial myopathy, encephalopathy, laetic acidosis, and stroke-like episodes (MELAS), which did not manifest external ophthalmoplegia clinically. By light microscopy, many granular and vesicular fibers were seen associated with endomysial fibrosis. Electron microscopy revealed that the fibers showed prominent accumulation of abnormal mitochondria, extensive loss of myofibrils, proliferation of free sarcoplasmic reticulum and an increased amount of lipid vacuoles. These changes were more pronounced in MELAS than in MERRF. Hirano bodies were often seen in the subsarcolemmal area of muscle fibers and also in the intramuscular myelinated nerve fibers and axon terminals. These findings suggest the presence of mitochondrial myopathy of the EOMs in cases of MELAS and MERRF.     

Mitochondrial abnormalities in human sural nerves: fine structural evaluation of cases with mitochondrial myopathy,hereditary and non-hereditary neuropathies,and review of the literature

Summary Fifteen cases of mitochondrial myopathy, three cases of hereditary motor and sensory neuropathy (HMSN) VI, and 280 cases of neuropathies of different etiologies were examined by electron microscopy for the presence of mitochondrial abnormalities in the sural nerve. Altered mitochondria were found in most cases of mitochondrial myopathy, in all cases of HMSN VI, and in 25 cases out of the series of unselected neuropathies. The mitochondrial changes comprised enlargement with an amorphous matrix and distorted cristae, with hexagonal paracrystalline inclusions, and with prominent cristae containing oblique striations, and a variety of rare changes. Most mitochondrial abnormalities were found in Schwann cells. An increase of the number of mitochondria was noted in smooth muscle and endothelial cells of epineurial arterioles of two cases with mitochondrial encephalomyopathy. Neuropathy was present in all cases of mitochondrial myopathy according to morphometrical analysis. Whether neuropathy is caused directly by mitochondrial dysfunction or by other pathogenetic mechanisms remains to be determined.Presented in part at the 9th meeting of the Peripheral Nerve Study Group, Praglia, Italy, August 31–September 2, 1989, and at the 9. Kongreß des wissenschaftlichen Beirates der DGBM über neuromuskuläre Erkrankungen, Hamburg, Germany, September 21–23, 1989