Granulomatous myositis. Clinicopathologic study of 12 cases.

Granulomatous inflammation is infrequently encountered in skeletal muscle biopsy material. Of 2,985 muscle biopsy specimens reviewed over 12 years, 12 (0.4%) with granulomatous inflammation were identified. The patients included 9 women who ranged in age from 24 to 76 years (mean 50.3 years). The most common clinical findings included decreased strength or weakness in the extremities (n = 8), muscle pain (n = 5), and weight loss (n = 3). All muscles exhibited nonnecrotizing granulomas; an associated vasculitic process was identified in 2. Endomysial chronic inflammation consisting primarily of lymphocytes and plasma cells was present in 10 muscles, and perivascular chronic inflammation in 8. Degenerating muscle fibers were noted in 10 cases, and regenerating fibers in 11. Evidence of neurogenic atrophy was seen in 8 muscles. Increased endomysial fibrosis was observed in 5 muscles, and type II muscle fiber atrophy in 5 muscles. Stains for acid-fast bacilli and Gomori methenamine silver stain were performed in all but 2 cases and failed to demonstrate organisms. In 3 cases, concomitant sural nerve biopsies were performed, and granulomas were identified in 2 of those cases. Clinicopathologic diagnoses included sarcoidosis (n = 6), vasculitis (n = 2), and granulomatous myositis not otherwise specified (n = 2). In 2 cases, there was insufficient clinical information or follow-up data to determine a cause. In conclusion, granulomatous myositis is infrequently found in muscle biopsy specimens (0.5% of all biopsies in this series); most muscles demonstrate evidence of chronic endomysial or perivascular inflammation accompanied by muscle fiber degeneration and regeneration; and the most common cause for granulomatous myositis was sarcoidosis in this series.     

Reduced expression of aquaporin 4 in human muscles with amyotrophic lateral sclerosis and other neurogenic atrophies

Aquaporin 4 (AQP4) is a water channel protein that is widely distributed in human tissues. However, the precise functional role of AQP4 in skeletal muscle tissue has not yet been determined. Expression of AQP4 was reported to be reduced in muscle tissue from Duchenne muscular dystrophy patients. In the regenerating phase of skeletal muscle, AQP4 expression was reduced when nerve supply was not present. However, in diseased human muscles with neurogenic atrophy including amyotrophic lateral sclerosis, there has been no data on the changes in AQP4 expression. In the present study, we investigated the expression of AQP4 at mRNA and protein levels in human muscles with neurogenic atrophy. The mean level of AQP4 mRNA was significantly lower in muscles with neurogenic atrophy than that in muscles from normal controls. The myofiber surface immunostaining with anti-AQP4 antibody in muscles with neurogenic atrophy was reduced on the surface of scattered myofibers, small angulated myofibers, and myofibers in small- and large-group atrophy despite the presence of dystrophin. Based on the present findings, we conclude that the expression of AQP4 is affected by nerve supply and is down-regulated in human muscles with neurogenic atrophy.     

Intracellular calcium in canine muscle biopsies

Intracellular staining for calcium was studied in muscle biopsies from 15 dogs by the alizarin red S (ARS) stain. Rare positive fibres were present in normal muscle and in denervation atrophy. The percentage of positive fibres was slightly increased in polymyositis, dermatomyositis and canine temporal/masseter myositis and markedly increased in progressive muscular dystrophy. Calcium-positive fibres were usually so-called large-dark (hypercontracted) fibres or necrotic fibres, although there was occasional staining of normal and atrophied fibres. These results indicate the probable involvement of calcium in muscle injury in canine inflammatory myopathies and in canine muscular dystrophy. In addition, use of the ARS stain appears to be useful for detecting the earliest lesions of acute muscle fibre injury.     

HISTOLOGICAL STUDY OF MUSCULAR CHANGES IN PROGRESSIVE MUSCULAR DYSTROPHY

Changes of skeletal muscle of 28 patients with progressive muscular dystrophy were studied light microscopically. Slowly progressive muscular atrophy with various forms of degeneration and more acute necrosis with incomplete regeneration were the principal changes. Fatty tissue infiltration and fibrosis of the interstitial tissue seemed to occur relatively late in the course of the disease. Incidence of necrosis and regeneration of muscle fibers are significantly higher in the Duchenne-type dystrophy and in an early stage, thus giving some quantitative difference concerning the genetic clinical types and duration of the disease, though no definite specific change is found for each type of muscular dystrophy.
Significance of these changes are discussed from a morphological standpoint and under consideration of biological speciality of muscle fiber. Regenerative substitution of necrotic muscle fiber performed by survived nuclei of the necrotic fiber itself in close association of myophago-cytosis appeared to be a peculiar process exhibited by skeletal muscle as a syncytial cell.     

Linkage of scapuloperoneal spinal muscular atrophy to chromosome 12q24.1-q24.31

Scapuloperoneal (SP) syndromes are heterogeneous neuromuscular disorders which are characterized by weakness in the distribution of shoulder girdle and peroneal muscles. SP syndromes can resemble facioscapulohumeral muscular dystrophy (FSH) due to scapular weakness or Charcot-Marie-Tooth disease (CMT) due to atrophy of peroneal muscles. Both neurogenic and myopathic SP syndromes have been described. Locus for the myopathic form of SP syndrome (scapuloperoneal muscular dystrophy, SPMD) has recently been assigned to chromosome 12q. We previously described a large New England kindred exhibiting an autosomal dominant neurogenic SP syndrome (scapuloperoneal spinal muscular atrophy, SPSMA). Disease expression was more severe and progressive in successive generations, which suggested genetic anticipation. We performed genetic linkage analysis of this family with microsatellite markers and excluded the loci for FSH, CMT, SPMD and SMA (spinal muscular atrophy) in our family. Linkage in our SPSMA family (lod score > 3) was established to seven microsatellite markers that map to chromosome 12q24.1-q24.31. The highest lod score with two-point linkage analysis was 6.67 (theta = 0.00) with marker D12S353. Multipoint analysis gave maximum lod scores of 7.38 between D12S354 and D12S79, and also 7.38 between D12S369 and NOS1 (neuronal nitric oxide synthase). The gene for SPSMA lies within the 19 cM interval between D12S338 and D12S366. This report establishes a locus for the neurogenic form of SP syndrome approximately 20 cM telomeric to the one described for the myopathic form of SP syndrome.      

Oculopharyngeal muscular dystrophy. Description of a case with involvement of the central nervous system

A sporadic case of oculopharyngeal muscular dystrophy occurred in a 74-year-old woman is described. High levels of IgA and IgG in the serum, and esophageal smooth muscle involvement are shown. Electromyography of several limb muscles displayed myopathic pattern with giant polyphasic motor unit potentials, suggesting superimposed denervation. The histological examination of peroneus brevis muscle biopsy specimen showed myopathic changes with dystrophic features, associated with neurogenic changes, including atrophic angulated fibers, small-group atrophy and type-grouping: concomitant involvement of spinal motor neuron pathway is hypotized, normal values of motor and sensory nerve conduction velocities excluding associated polineuropathy. Furthermore, Somatosensory Evoked Potentials recording revealed bilaterally increased Central Conduction Time. Referring to other similar cases previously reported in the literature, the significance of neurogenic involvement in oculopharyngeal muscular dystrophy is discussed.     

Localization of O-GlcNAc-modified proteins in neuromuscular diseases

O-linked N-acetylglucosamine (O-GlcNAc) is a ubiquitous post-translational modification of nucleocytoplasmic proteins that induces the attachment of N-acetylglucosamine to serine or threonine residues of a protein. In contrast to other protein glycosylations, this modification is highly reversible and, similar to phosphorylation, it plays important roles in various cell signals. Here, we immunolocalized O-GlcNAc-modified proteins in muscle biopsy specimens from 40 patients with neuromuscular diseases and controls. In normal muscle fibers, O-GlcNAc was found along plasma membranes and in nuclei. Diffuse and increased cytoplasmic staining of O-GlcNAc was detected in (1) regenerating muscle fibers in muscular dystrophy, myositis, and rhabdomyolysis; (2) a proportion of atrophic fibers in myositis, such as those found in perifascicular regions in dermatomyositis; and (3) vacuolated fibers in sporadic inclusion body myositis (s-IBM) and distal myopathy with rimmed vacuoles (DMRV). Target formations in neurogenic muscular atrophy were O-GlcNAc positive. Increase of O-GlcNAc glycosylation could be associated with the stress response, as these lesions have been shown to be positive for several stress markers. Vacuolar rims in s-IBM and DMRV were sometimes sharply lined by O-GlcNAc-positive deposits, which reflects myonuclear breakdown occurring from the disease.     

HISTOPATHOLOGICAL STUDY ON PROGRESSIVE MUSCULAR DYSTROPHY—REPORT OF A CASE WITH AUTOPSY FINDINGS—

A typical case of the D uchenne type of progressive muscular dystrophy with autopsy findings was presented. Changes in the myocardial and smooth muscle of many organs were found, and the skeletal muscles also revealed florid changes.
Histopathological examination of the skeletal muscle was made in detail through light and electron microscopic observation.     

A case of myasthenia gravis proven by ultrastructural study

Although light microscopic features of muscle are not pathognomonic in most cases of myasthenia gravis (MG), careful examination of neuromuscular junction by electron microscopy (EM) can reveal important clues for this disease. We report here a case of MG confirmed by EM study to emphasize that tissue diagnosis is still the best adjuvant to confirm the diagnosis. An 18-year-old female visited our hospital complaining of progressive muscle weakness for 3 years. She had difficulty in running, going upstairs and doing routine activities. Symptoms were aggravated with continuous work and resolved after rest. She had weakness of bilateral masseter and facial muscles and proximal portions of extremities without definite diurnal variation. Electromyography showed myopathic changes in proximal muscles of extremities. MG was considered but tensilon test was equivocal. Repetitive nerve stimulation tests revealed 20-30 percent decrease in responses to low and high rate stimulation. Muscle biopsy revealed selective type 2 atrophy. Ultrastructurally, abnormalities of neuromuscular junctions, i.e., wide primary synaptic cleft, and wide and shallow secondary synaptic clefts with mild myopathic features were present. These findings were pathognomonic for MG. Later, her symptoms were improved completely 3 months after thymectomy. The histologic finding of thymus was follicular hyperplasia.     

Acetylcholine receptor and thymus in experimental autoimmune myasthenia gravis and experimental myositis.

This study was attempted to obtain information about biological properties of junctional acetylcholine receptor (AChR) and extrajunctional AChR, and about nerve influences on muscles AChRs under the pathological conditions of experimental myasthenia and myositis. Experimental autoimmune myasthenia gravis (EAMG) was induced in Wistar rats by immunizations with AChR purified from the electric organ of Narke Japonica without using Freund's complete adjuvant experimental myositis by immunization with rat muscle extract depleted of AChR. Thirty-five days after the initial immunization, unilateral dissection of the ischiadic nerve was performed in all immunized rats. Contents of AChR in both hind limb muscles were measured by double immunoprecipitation assay method 15 days after the experimental denervation. In the control animals the amount of AChR extractable from innervated muscles was 2.7 +/- 0.5 (mean +/- s.d.) pmole/g muscle and increased about 10-fold 15 days after the denervation (30 +/- 7.9). In rats with EAMG, AChR contents was reduced in both denervated (1.1 +/- 1.0) and innervated muscles (1.3 +/- 0.9). In experimental myositis, the increase of muscle AChR was impaired in denervated muscles (2.4 +/- 0.6), but AChR contents was not reduced in innervated muscles (2.7 +/- 0.9). These results suggest that nerves may influence AChR metabolism, keeping numbers of AChR constant even in inflammatory condition. In addition, germinal centre formation in thymic medulla was detected in EAMG rats.     

儿童常染色体显性遗传Emery-Dreifuss肌营养不良症1例并文献复习

目的 提高对常染色体显性遗传Emery-Dreifuss 肌营养不良症（EDMD）的临床和分子生物学特点的认识.方法 总结1例EDMD患儿的临床表现、诊断、肌肉活检病理学和基因检测结果,并综合文献进行分析.结果 女性,12岁,表现为进行性四肢无力,近端为著,脊柱僵硬,伴明显的双侧跟腱、肘挛缩.血浆肌酶轻度升高.肌电图提示肌源性改变,运动和感觉神经传导速度正常.股四头肌活检病理学检查显示肌肉细胞大小不均,萎缩和肥大的纤维交替存在,部分肌纤维代偿性肥大,脂肪及结缔组织增生明显,符合肌营养不良的病理表现.基因检测发现LMNA基因外显子4的序列变异c.746G〉A（p.Arg249Gln）.结论 基因分析是确诊EDMD的最可靠方法.对进行性的、双侧对称的肌肉无力,并伴有肘关节、跟腱挛缩和脊柱僵硬的患儿应进行LMNA基因分析,有助于早期诊断EDMD.     

Congenital muscular dystrophy associated with micropolygyria - report of two cases.

This is a report on two autopsy cases of congenital muscular dystrophy associated with micropolygyria. The first case was that of an 11-year-old boy and the other of a 22-year-old male adult. Both cases had similar clinical features, very early onset of disease, diffuse and extensive wasting of skeletal muscles including facial muscles, contracture of joints, hypotonia and mental retardation. In the familial histories of these two cases, the parents of the boy were consanguineous, and a sister of the adult case suffered from muscle weakness and mental retardation. Both of these two cases were clinically diagnosed as congenital cerebromuscular dystrophy (Fukuyama's type). Autopsy revealed marked dystrophy of generalized skeletal muscles and widespread micropolygyria of the brain in both cases. Spinal cords and peripheral nerves were free from any prominent changes. It was concluded that so-called congenital cerebromuscular dystrophy may be caused by myogenic as well as neurogenic abnormalities during fetal period.     

A Neurogenic Component in Muscular Dystrophy

Evidence for a neurogenic component in mouse and human muscular dystrophy is briefly reviewed. Such evidence comes from certain clinical observations, electrophysiological studies, muscle pathology, nervous system pathology, transplantation experiments in animals, and tissue culture studies. The evidence is at present rather conflicting though the results of recent tissue culture experiments are more convincing. If there is a neurogenic component in dystrophy then the basic defect may have to be sought in the central nervous system rather than in the muscle itself. It is argued, however, that a neurogenic component in dystrophy cannot be simply a defect in the anterior horn cells of the spinal cord since the clinical features and the laboratory and pathological findings are quite different from those in spinal muscular atrophy.     

Vergleichende elektrophoretische Untersuchungen über Muskelproteine bei normalem,neurogen atrophischem un myopathisch verändertem Skeletmuskel

Zusammenfassung Gewebeproben von pathologischem, menschlichen Skeletmuskel (neurogene Atrophie, Myopathie, Myositis) werden disc-elektrophoretisch aufgetrennt und mit spezifischen Protein- und Enzymfärbungen untersucht. Der Vergleich der erhaltenen Proteinmuster mit denen des normalen menschlichen Skeletmuskels zeigt deutliche Abweichungen im Aldolase- und Peroxydase-Zymogramm sowie geringe Unterschiede bei der LDH und CPK. Phosphorylase- und ATPase-Aktivität ist beim pathologischen Skeletmuskel nicht sicher nachweisbar.

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Summary Disc electrophoresis of biopsy samples from pathological, human skeletal muscle (neurogenic atrophy, muscular dystrophy, myositis) reveals distinct patterns of protein fractions. These are related to specific enzymatic activities by specific protein staining methods. The pattern of protein fractions in normal and pathological skeletal muscle are compared. There are found distinct divergences in the aldolase- and peroxydase-zymograms and small differences in LDH-and CPK-activity. Phosphorylase- and ATPase-activity is not surely demonstrable.

     

Diagnostic yield associated with multiple simultaneous skeletal muscle biopsies

Certain skeletal muscle disorders, such as inflammatory myopathies, may show regional variability, prompting consideration of simultaneous biopsy of more than 1 muscle to increase the likelihood of diagnosis. There are few data in the literature to support this approach. This study is a retrospective 8-year review of 99 cases (52 men; mean age, 61.8 years) who had multiple muscles biopsied simultaneously. The most common clinical symptoms prompting biopsy included weakness in 83 cases and myalgia in 15. The most common diagnoses were as follows: neurogenic atrophy, 48; inflammatory myopathy, excluding inclusion body myositis, 29; and type II muscle fiber atrophy, 24. Diagnoses were the same in both biopsied muscles in 54 cases (55%). In 17 cases, a diagnosis was made from only 1 biopsy. Of 29 inflammatory myopathies and vasculitis (excluding inclusion body myositis), a diagnosis could be made from only 1 of the 2 biopsies in 10 cases (34%). In a significant subset of cases, a potentially treatable inflammatory myopathic condition might have been missed if only 1 site had been biopsied, justifying biopsy of 2 sites in suspected cases of inflammatory myopathy.     

Cytofluorometric determination of nuclear DNA in heart muscles of patients with muscular dystrophy

The degree of DNA-polyploidy of cardiac muscle cells was investigated by cytofluorometry in 4 cases of progressive muscular dystrophy (DMP) and 2 cases of myotonic dystrophy (DM), and the results were compared with those for non-dystrophic hearts of normal or increased weight. The heart muscle cells from all patients with these forms of dystrophy showed marked nuclear DNA hyperploidy reaching 16c, irrespective of cardiac hypertrophy or atrophy. In the non-dystrophic group, DNA hypertrophy corresponding to that of dystrophy was only detected in cases of marked cardiac hypertrophy exceeding a weight of 400 g. The wasting of the respiratory musculature, deformity of the thorax and cardiac muscular atrophy appeared to be the principal factors causing DNA polyploidy in patients with muscular dystrophy.     

CONGENITAL MUSCULAR DYSTROPHY ASSOCIATED WITH MICROPOLYGYRIA - REPORT OF TWO CASES

This is a report on two autopsy cases of congenital muscular dystrophy assoicated with micropolygyria. The first case was that of an 11-year-old boy and the other of a 22-year-old male adult. Both cases had similar clinical features, very early onset of disease, diffuse and extensive wasting of skeletal muscles including facial muscles, contracture of joints, hypotonia and mental retardation. In the familial histories of these two cases, the parents of the boy were consanguineous, and a sister of the adult case suffered from muscle weakness and mental retardation. Both of these two cases were clinically diagnosed as congenital cerebromuscular dystrophy (Fukuyama's type). Autopsy revealed marked dystrophy of generalized skeletal muscles and widespread micropolygyria of the brain in both cases. Spinal cords and peripheral nerves were free from any prominent changes. It was concluded that so-called congenital cerebromuscular dystronphy may be caused by myogenic as well as neurogenic abnormalities during fetal period.     

Histopathology of different types of atrophy of the human tongue

Numerous studies have been devoted to the various histopathologic changes of the surface of the tongue. The muscles of the tongue and their changes in the process of ageing as well as in neurogenic atrophies, however, have not been systematically examined so far. Enlarging upon previous studies, an autopsy material of 170 tongues from all age groups was histologically examined in order to identify the steps in the development of age-related atrophy. These are characterized by a histometrically documented atrophy of the musculature with progressive lipomatosis. Fatty infiltration starts in the 2nd/3rd decade at three sites of predilection: body, root and tip of the tongue in the region of the anterior lingual gland (NUHN). The age-dependent atrophy and the known clinical behaviour of neurogenic atrophies of the tongue are correlated with the histopathology of three typical forms: a neurogenic myasthenic atrophy of the tongue with high-grade symmetrical fatty replacement as an expression of a progressive myasthenic denervation; a lipomatous atrophy of the tongue as a late stage of poliomyelitis and long-term treatment in the "Iron Lung", and a lipomatous hemiatrophy due to posttraumatic extracranial hypoglossus paresis. The paretic part of this tongue consists of 85-90% fatty tissue. The different degrees of muscular atrophy of the tongue are largely compensated by metaplasia of fatty tissue in the perimysium following muscular degeneration (in the sense of a fatty replacement). With the exception of general and severe myasthenic atrophy, size, form and function of the tongue fail to show any significant changes in age-related atrophy and hemiatrophy.     

Expression of transforming growth factor-beta 1 and its relation to endomysial fibrosis in progressive muscular dystrophy.

Progressive muscular dystrophy is characterized by muscle fiber necrosis, regeneration, and endomysial fibrosis. Although absence of dystrophin has been known as the cause of muscle fiber degeneration, pathogenesis of interstitial fibrosis is still unknown. Transforming growth factor-beta 1 (TGF-beta 1) induces accumulation of extracellular matrix in various diseases, such as liver cirrhosis and interstitial pneumonitis. To investigate its function on the pathogenesis of progressive muscular dystrophy, it was necessary to determine the degree of TGF-beta 1 expression and the site of TGF-beta 1 immunoreactivity. In Duchenne muscular dystrophy and most of Becker muscular dystrophy, high TGF-beta 1 immunoreactivity expressed on muscle fibers and extracellular space. In other myopathies with endomysial fibrosis, however, TGF-beta 1 was seldom observed. We also examined the immunoreactivity of the latent TGF-beta binding protein, which is bound to the TGF-beta precursors. In all Duchenne muscular dystrophy and half of Becker muscular dystrophy cases, high latent TGF-beta 1 binding protein immunoreactivity was seen, but in other myopathies its immunoreactivity was seldom seen on muscle fibers or extracellular space. Therefore TGF-beta 1 may play an important role in synthesis and accumulation of extracellular matrix in progressive muscular dystrophy.     

Cytofluorometric Determination of Nuclear DNA in Heart Muscles of Patients with Muscular Dystrophy

The degree of DNA polyploidy of cardiac muscle cells was investigated by cytofluorometry in 4 cases of progressive muscular dystrophy (DMP) and 2 cases of myotonic dystrophy (DM), and the results were compared with those for non dystrophic hearts of normal or increased weight. The heart muscle cells from all patients with these forms of dystrophy showed marked nuclear DNA hyperploidy reaching 16c, irrespective of cardiac hypertrophy or atrophy. In the non dystrophic group, DNA hypertrophy corresponding to that of dystrophy was only detected in cases of marked cardiac hypertrophy exceeding a weight of 400 g. The wasting of the respiratory musculature, deformity of the thorax and cardiac muscular atrophy appeared to be the principal factors causing DNA polyploidy in patients with muscular dystrophy. Acta Pathol Jpn 39: 566 572,1989.