摘要:

AbstractHuman idiopathic inflammatory myopathy is an acquired disorder with an annual incidence of two to five cases per million. A genetic influence of two to five cases per million. A genetic influence on host susceptibility may also play a role. With the marked heterogeneity of the disease one of the major challenges is to identify subsets that might share a more uniform pathogenesis and manifest a less diverse profile of clinical findings, histopathological abnormalities, and natural history. Dermatomyositis can be distinguished by clinical appearance and pathological changes, but the recognition of additional disease subsets remains very inexact. Current evidence suggests that dermatomyositis occurs as a result of a vasculopathy, but immune mechanisms involved in other categories of idiopathic inflammatory myopathy may also involve cell‐mediated immunity and possibly multiple mechanisms. Even though viral‐induced muscle inflammation occurs in humans, there is no convincing evidence for a viral cause of idiopathic inflammatory myopathy. Experimental allergic myositis may be produced by the injection of animals with skeletal muscle homogenates and complete Freund's adjuvant, but the myositogenic factor is unknown and the parallels between experimental allergic myositis and human idiopathic inflammatory myopathy are limi

ISSN:0148-639X    

DOI:10.1002/mus.880050802

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractA modification of the twin pulse method is described, by which the nerve tested is stimulated at one proximal site percutaneously and the neuromuscular response to it is derived from a dependent muscle. An electronic subtraction procedure provides separation of the conditioned muscle action potential for measurement by means of a microcomputer. Several parameters were determined in the conditioned action potential and compared to the same criteria in an unconditioned single action potential. Changes of the conditioned action potential were measured at fixed stimulus intervals between 2 and 6 msec. Preliminary normal ranges interindividually and intraindividually were established. Their dependency on skin surface temperature was determined. In polyradiculoneuropathy, the data for motor nerve conduction velocity were characteristically pathologic, and neuromuscular reaction to paired stimuli data deviated minimally from normal. In vincristine neuropathy, motor nerve conduction velocity was normal, but neuromuscular reaction to paired stimuli data fell outside the normal range early in the clinical course. Since polyradiculoneuropathy is a primary demyelinating and remyelinating process and vincristine neuropathy is an example of axonal degeneration, neuromuscular reaction to paired stimuli can facilitate the differential diagnosis in polyneuropathy. Furthermore, this method seems apt to quantify axonal degeneration. In a mixed form of polyneuropathy, peroneal muscular atrophy, motor nerve conduction velocity, as well as neuromuscular reaction to paired stimuli, were abnormal, the latter resulting in abnormally high relative amplitudes. In muscle disorders such as Duchenne muscular dystrophy, neuromuscular reaction to paired stimuli data was abnormal, contrasting experiments using double stimulation of the diseased muscle itself.

ISSN:0148-639X    

DOI:10.1002/mus.880050803

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractTwo patients, a father and his 14‐year‐old son, were suffering from a facioperoneal syndrome, and muscle biopsy findings were consistent with a myotubular myopathy. The father exhibited central nuclei in most muscle fibers, but his son had typical changes exclusively in hypotrophic type I fibers. The cytochemical and ultrastructural analysis revealed a spectrum of pathological changes typical of myotubular myopathy. Energy‐dispersive electron probe x‐ray microanalysis was performed on 6‐to 12‐μm thick freeze‐dried cryosections visualized in the scanning or scanning transmission mode of electron microscopy. We found a high intracellular sodium and chlorine concentration and a low potassium concentration in comparison with control muscles. These changes pointed in the direction similar to results from human fetal muscle. The changes in the intracellular elemental composition may indicate a membrane pump dysfunction, which might be caused by a partial arrest in muscle fi

ISSN:0148-639X    

DOI:10.1002/mus.880050804

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractSodium currents from human external intercostal muscle fibers were recorded using the Hille‐Campbell voltage clamp method. Sodium currents are analyzed in terms of themandhparameters of the Hodgkin‐Huxley model. The results indicate that the kinetics and voltage dependence of sodium currents in human skeletal muscle fibers are very similar to those reported in rat fib

ISSN:0148-639X    

DOI:10.1002/mus.880050805

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractA new technique is being developed to remedy muscle weakness of hereditary myopathies. Mesenchymal cells dissected from limb‐buds of day‐12 normal mouse embryos were transplanted into the right solei of 20‐day‐old normal or dystrophic C56BL/6J‐dy2Jmice. Host and donors were immunocompatible. Unoperated left solei served as controls. Sham control solei receiving similar surgical treatment but no mesenchyme transplant did not differ from contralateral, unoperated solei. Six to seven months postoperatively the test solei (8 normal and 15 dystrophic) exhibited greater cross‐sectional area, total fiber number, and twitch and tetanus tensions than their contralateral controls. Test dystrophic solei contained more normal‐appearing and less abnormal‐appearing fibers than their controls. Their mean fiber resting potential was intermediate between those of normal and dystrophic controls. There is no difference in twitch time course between test and control solei. The results indicate that such transplantation improves the structure and function of the dys

ISSN:0148-639X    

DOI:10.1002/mus.880050806

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractThe response of human muscles triceps brachii and vastus lateralis to training, consisting of 18.5 miles a day of skiing with a backpack, 6 days a week for 8 weeks, has been investigated by means of histochemical fiber typing (myofibrillar ATPase) as well as immunohistochemical discrimination of slow and fast myosin (n= 6). A detraining period of 33 weeks was also studied. The percentage of type 2 fibers decreased by 6% in the triceps brachii during training, whereas the intermediate fiber type increased by 4%. No change was found in the distribution of fiber types in the vastus lateralis during training or in both muscles during detraining. The ATPase intermediate fibers also stained intermediately in the immunohistochemical stainings for slow and fast myosin. These results show that transformation of a fraction of the type 2 fibers into the intermediate type may occur as a response to endurace training.

ISSN:0148-639X    

DOI:10.1002/mus.880050807

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractAn 8‐month‐old child underwent a muscle biopsy because of hypotonia. The biopsy showed centronuclear myopathy and, in addition, an unusual granulomatous inflammatory infiltrate. The child died of respiratory complications and a complete autopsy failed to reveal further evidence of granulomatous disease. The lesion was reproduced in experimental animals by intramuscular injection of diphtheria and tetanus toxoids and pertussis vaccine. Granular material present in histiocytes in these lesions was shown histochemically to be an aluminum s

ISSN:0148-639X    

DOI:10.1002/mus.880050808

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractComparison of morphological features of gastrocnemius muscle fibers in normal and dystrophic (dy2J) mice during development was undertaken to determine the time course of increased oxidative capacity in dystrophic fibers. Measurements of mitochondrial volume percent and of Z‐line width were made in superficial fast‐twitch fibers using electron microscopy and stereological techniques. Dystrophic fibers develop a progressively higher mitochondrial volume percent than normal fibers after 1 month of age. Z‐line width is positively correlated with mitochondrial volume percent. The results support the hypothesis that progressive changes in muscle fiber properties result from abnormal neural activity (pseudomyotonia) in dystrophic an

ISSN:0148-639X    

DOI:10.1002/mus.880050809

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractWe report the occurrence of large clefts and branches in some amphibian vertebrate skeletal muscle fibers. Such fibers can be isolated intact from various skeletal muscles of fully mature animals and apparently are normal in other respects. Electron micrographs showed no signs of degeneration in most fibers. Electrical and mechanical studies revealed that all branches were excitable and able to contract. Branches evidently can arise in the absence of abnormal influences such as experimentally induced overload. The apparent cause may be either fusion or splitting of fibers.

ISSN:0148-639X    

DOI:10.1002/mus.880050810

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractNeurons of origin of the rat sural nerve were labelled with horseradish peroxidase. Dorsal root ganglionic cells were located in the L4 and L5 ganglia, and occasionally at the L6 level. Most of these sensory neurons measured under 35 μm in diameter. In keeping with previous electrophysiological studies suggesting the presence of motor fibers to plantar muscles in the rat sural nerve, motoneurons were identified at the caudal end of the L5 spinal segment, intermingled in the posterior aspect of the ventral horn with posterior tibial motor cells supplying the foot muscles. A quantitative analysis of HRP‐labelled motoneurons revealed no difference between normal (average 67) and deafferented animals (average 70), the values being only marginally lower than counts of motor axons in deafferented sural nerves (average 8

ISSN:0148-639X    

DOI:10.1002/mus.880050811

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY