ISSN:0148-639X    

DOI:10.1002/mus.880040402

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

年代:1981

数据来源: WILEY

摘要:

AbstractIn order to investigate whether Schwann cell or myelin was the principal antigen responsible for nerve graft reiection, fresh nerve grafts and those in which myelin had been previously allowed to degenerate (predegenerate grafts) from both isogeneic BALB/c and allogeneic C57/B1 mice were inserted into trembler BALB/c mice. Schwann cells within nerve allografts from C57/B1 mice were rejected, whether or not the grafts contained myelin. Nerve isografts from normal BALB/c animals produced normally myelinated trembler axons within the grafted segments, and across these segments conduction velocity was restored towards the normal value. It is concluded that Schwann cells, not myelin, constitute the principlal antigen within nerve allografts and it is Schwann‐cell rejection that limits the sucessful use of nerve allograft

ISSN:0148-639X    

DOI:10.1002/mus.880040403

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe heterogeneity of the specificities of anti‐acetylcholine receptor (anti‐AChR) antibodies of myasthenia gravis (MG) patients has been demonstrated by comparing reactions against a panel of xenogeneic AChR. For each patient there was a more or less unique cross‐reactivity profile. Such heterogeneity emphasizes the need to use human AChR for the routine detection of anti‐AChR. In vitro cross‐reactivity was important in predicting the effect of anti‐AChR after passive transfer to rats. Specificity may influence the outcome in human neonates receiving maternal anti‐AChR via the placenta. In contrast to the extreme heterogeneity seen in spontaneous MG, the antibodies associated with D‐penicillamine–induced MG were

ISSN:0148-639X    

DOI:10.1002/mus.880040404

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

年代:1981

数据来源: WILEY

摘要:

AbstractIn the acquired form of myasthenia gravis in dogs, there are circulating antibodies to acetylcholine receptors (AChRs) and a reduction in the number of AChRs in the postsynaptic membrane. In this study, immune complexes were localized at the neuromuscular junctions in biopsy samples from 10 myasthenic dogs by immunocytochemical means employing conjugates of staphylococcal protein A and horseradish peroxidase. Immune complexes were observed in approximately 70% of the neuromuscular junctions studied in both type 1 and type 2 myofibers. Thus, acquired canine myasthenia gravis appears to involve immune‐mediated mechanisms that destroy AChRs in a manner similar to myasthenia gravis in humans. Protein A was also observed to bind principally to elastic fibers in small arteries and arterioles of some myasthenic and control dogs; however, the significance of that localization is unknow

ISSN:0148-639X    

DOI:10.1002/mus.880040405

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

年代:1981

数据来源: WILEY

摘要:

AbstractAn 81‐year‐old man from a family with a history of oculopharyngeal muscular dystrophy (OPMD) involving 6 members over 4 generations is described. The patient first noted drooping of his eyelids at the age of 65. Dysphagia and dysarthria occurred soon thereafter. At age 78, impairment of gait developed and progressive wasting occurred in the limbs with an initial distal distribution. Electromyography of several limb muscles displayed a mixed myopathic and neurogenic pattern with giant potentials. Examination at autopsy revealed slight loss of neurons in the anterior horns of the spinal cord, with scanty ghost cells, neuronophagia, and central chromatolysis. By light microscopy the limb muscles showed moderate small‐group atrophy with severe myopathy and target fibers. The viscerocranial muscles, including the ocular, vocal, and tongue muscles, demonstrated only myopathic change with the typical features of progressive muscular dystrophy. Advanced replacement by fibrous connective tissue and fat had occurred in both the viscerocranial and the lower limb muscles. The significance of neurogenic involvement in OPMD is disc

ISSN:0148-639X    

DOI:10.1002/mus.880040406

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe nature of the defect in congenital myasthenia was investigated in biopsy specimens of intercostal muscle from 5 male patients whose symptoms presented between birth and 2 years of age. Miniature end‐plate potentials were reduced in amplitude in all 5 patients. The number of acetylcholine receptors as determined by α‐bungarotoxin binding was normal in case 1 and reduced in cases 2, 4, and 5. The shape of the endplates as shown by autoradiography and cholinesterase staining was normal in case 1 and elongated in cases 2, 4, and 5. In case 3, α‐bungarotoxin binding was slowly reversible, and there were some muscle fibers with multiple end‐plate regions. The acetylcholine content of the muscle was normal in all 5 cases. None of the patients had serum antibody to human acetylcholine receptor as measured by immunoprecipitation or inhibition of α‐bungarotoxin binding. We conclude that congenital myasthenia is a heterogeneous condition of nonimmune etiology in which both presynaptic and postsynaptic defects

ISSN:0148-639X    

DOI:10.1002/mus.880040407

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

年代:1981

数据来源: WILEY

摘要:

AbstractTellurium is known to induce a neuropathy in young rats but not in adult rats. In the present study adult rats were fed a diet containing 1.25% tellurium every day for 30 days. By the end of this period, the rats moved with difficulty but did not show paralysis. Study of teased nerve fiber preparations in conjunction with light and electron microscopy revealed myelin abnormalities consisting of myelin bubbling, segmental demyelination, and remyelination. In some animals, these abnormalities had a patchy distribution, affecting several adjoining nerve fibers in sciatic nerves, brachial plexus, and spinal roots. The intramyelinic edema sometimes was associated with splitting of the axons.

ISSN:0148-639X    

DOI:10.1002/mus.880040408

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

年代:1981

数据来源: WILEY

摘要:

AbstractUndifferentiated type 2C fibers, which are dark on ATPase staining with both alkaline and acid preincubation, comprised on average 16.1% of the muscle fibers in 12 patients with Duchenne muscular dystrophy (DMD). Many of type 2C fibers had characteristics of regenerating fibers: basophilic cytoplasm, vesicular nuclei with occasional prominent nucleoli, high alkaline phosphatase and nonspecific esterase activity, and also high oxidative enzyme activity at the periphery of the fiber. A localized high acetylcholinesterase activity suggested the presence of a neuromuscular junction in some of the type 2C fibers. In serial sections, histochemical reactions characteristic of the type 2C fiber were present in segments of a single fiber, which in other parts was either a type 1 or a type 2 fiber. Since most of the opaque (hyaline, dark) fibers, which previously have been thought to be precursors of necrotic fibers, behaved as differentiated type 1 or type 2 fibers, the presence of type 2C fibers in DMD may not reflect “dedifferentiation” of fiber type, but rather indicate an active regenerating process. It remains unknown whether the type 2C fiber segments in DMD develop into fully differentiated functional fibers or remain as incompletely regenerated fib

ISSN:0148-639X    

DOI:10.1002/mus.880040409

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

年代:1981

数据来源: WILEY

摘要:

AbstractDisorders of neuromuscular transmission in humans are caused by a wide variety of agents including systemic diseases, drugs, environmental toxins, animal envenomation, cations, and hormones. Some are genetically determined. Many are of unknown etiology. All such disorders interfere with one or more events in the sequence whereby a nerve impulse excites a muscle action potential. In many disorders of neuromuscular transmission, abnormal fatigue occurs, and some cases respond dramatically to treatment. Investigation of the microphysiology, microanatomy, and pharmacology of both normal and diseased neuromuscular junctions has increased our knowledge of these disorders.

ISSN:0148-639X    

DOI:10.1002/mus.880040410

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe myofiber type composition was studied in 42 different muscles of the dog to determine if there are unique features that might explain the preferential involvement of the muscles of mastication by inflammatory myopathies. The principal myofiber types for most muscles studied were type 1 and type 2A and, to a lesser extent, type 2C, wherease the dorsal group of muscles innervated by the mandibular nerve (Mm. temporalis, masseter, pterygoideus lateralis, pterygoideus medialis, tensor tympani, and tensor veli palatini) was composed only of type 2C myofibers and a variant of the type 1 myofiber whose staining intensity was not fully reversed after preincubation in acid media. The distribution of this myofiber type composition was associated with the innervation and embryologic development of the dorsal muscles innervated by the mandibular nerve. This unique myofiber type composition could provide the basis for the preferential susceptibility of these muscles to agents (e.g., immune and/or infectious) that produce myositis; however, further studies are required to assess that possiblity.

ISSN:0148-639X    

DOI:10.1002/mus.880040411

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

年代:1981

数据来源: WILEY