摘要:

AbstractDuchenne and Becker muscular dystrophy are caused by defects in dystrophin synthesis. Using affinity‐purified polyclonal anti‐dystrophin antibodies, we have studied immunohistochemically the subcellular localization of dystrophin in embryonic, fetal, and adult human skeletal muscle. In the embryonic stages dystrophin first appears in the sarcoplasm at the peripheral ends of the myotubes, immediately adjacent to the tendons, whereas in fetal stages dystrophin is found throughout the entire myofibers. In agreement with literature data, in adult muscle dystrophin expression was found to be restricted to the sarcolemma. The sarcoplasmic localization in embryonic and fetal tissue and the sarcolemmal localization of dystrophin in mature muscle suggests the accumulation of dystrophin in the cytoplasm prior to its integration into the membrane. These results increase our knowledge of the ontogenesis of dystrophin and may lead to a better understanding of the great diversity in pathological cases of Duchenne and Becker muscular dystro

ISSN:0148-639X    

DOI:10.1002/mus.880140102

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

年代:1991

数据来源: WILEY

摘要:

AbstractFactors that affect the shape of the so‐called “normal cloud” of the turns and amplitude measurements of the electromyographic interference pattern are investigated. As the force of voluntary contraction increase from low to moderate levels, the number of turns in the signal increase faster than does the mean amplitude change between turns. This results in a cloud that is concave downward. At higher force levels, the pattern is reversed. The overall shape of the cloud thus depends on the maximum effort at which recordings are made, which is determined by the procedure of muscle activ

ISSN:0148-639X    

DOI:10.1002/mus.880140103

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

年代:1991

数据来源: WILEY

摘要:

AbstractPreviously, embryonic tissues have been used to produce monolayer cultures containing mammalian spinal cord neurons (SCN) and motoneurons (MN) for studies of the pathophysiology of motoneuron diseases. We demonstrate here that viable SCN and MN were observed in dissociated cultures from neonatal rat and mouse. These SCN and MN produced neurites and expressed acetylcholinesterase, neuron‐specific enolase and neurofilament protein. These results indicate that cultured postnatal SCN and MN are capable of survival, neurite extension, and phenotypic expression in cultur

ISSN:0148-639X    

DOI:10.1002/mus.880140104

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

年代:1991

数据来源: WILEY

摘要:

AbstractDetailed electrophysiological studies were performed in 4 patients with myeloneuropathy induced by abuse of nitrous oxide for 1 to 4 years. All presented with paresthesias, weakness, and Lhermitte's phenomena, and exhibited signs of sensorimotor polyneuropathy, ataxia, and arreflexia. Two had subnormal serum vitamin B12levels. Baseline electrophysilogic testing revealed reduced motor unit potentials, prolonged F wave latencies, absent H refelxes, denervation potentials, and delays in motor and sensory conduction. Three had peripheral and nuchal delay after median nerve stimulation. All were reevaluated after 3 to 12 months abstinence and treatment with vitamin B12, and all showed substantial clinical improvement. Parallel improvement in electrophysiologic findings occurred, but residual minor conduction delays, loss of H reflexes, electromyographic evidence of denervation, or abnormalities of posterior tibial SEP were noted. These findings confirm the reversibility of myeloneuropathy of nitrous oxide abuse and describe the profile of electrophysiologic recovery in subjects who abstain from further neurotoxic exposure.

ISSN:0148-639X    

DOI:10.1002/mus.880140105

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

年代:1991

数据来源: WILEY

摘要:

AbstractIn anesthetized rabbits the efficiency of phrenic nerve stimulation with trains of electric current was studied either when ventilation was effected entirely by bilateral nerve stimulation (electrophrenic ventilation) or during unilateral nerve stimulation when animals were ventilated with a pump and open chest. Trains of rectangular electric pulses (RPT) with constant amplitude and frequency or sine waves, both the amplitude and frequency of which were modulated and controlled by a computer (MSWT), were used with each animal. MSWT closely reproduced the physiological shape of transdiaphragmatic pressure waves. Diaphragm fatigue, as determined from the decrease in the maximal relaxation rate of twitches, occurred after 20 minutes of bilateral or unilateral nerve stimulation with RPT, but only after 60 min (unilateral stimulation) or 98 min (bilateral stimualtion) with MSWT. These data show the importance of the motor signal pattern in long‐lasting nerve stimulatio

ISSN:0148-639X    

DOI:10.1002/mus.880140106

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

年代:1991

数据来源: WILEY

摘要:

AbstractThirteen patients with mitochondrial cytopathy were investigated. They represent different generations, ages, stages, and severities of the disease. All were assumed to have the same metabolic defect. The disease is a multisystem disorder with a metabolic defect located at complex 1 in the respiratory chain. Clinically, the disorder gives symptoms such as hearing loss, retinal pigmental degeneration, ataxia, cardiomyopathy, muscular fatiguability and neuropathy. The patients were investigated with nerve conduction studies, concentric needle EMG, SFEMG, and macro EMG examinations. Neurophysiologic studies revealed signs of myopathy in both the younger members and in those with slight muscular symptoms. In the more advanced stages, neuropathic changes of the axonal type were seen as well. Macro EMG was interpreted as indicating muscle fiber membrane abnormalities in the early stages. Single fiber EMG studies indicate that this metabolic defect does not distrub neuromuscular transmission.

ISSN:0148-639X    

DOI:10.1002/mus.880140107

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe mdx mouse, although a genetic and biochemical homologue of human Duchenne muscular dystrophy (DMD), presents a comparatively mild histopathological and clinical phenotype. These differences are partially attributable to the greater efficacy of regeneration in the mdx mouse than in DMD muscle. To lessen this disparity, we have used a single dose of X‐irradiation (16 Gy) to inhibit regeneration in one leg of mdx mice. The result is an almost complete block of muscle fiber regeneration leading to progressive loss of muscle fibers and their replacement by loose connective tissue. Surviving fibers are mainly peripherally nucleated and, surprisingly, of large diameter. Thus, X‐irradiation converts mdx muscle to a model system in which the degenerative process can be studied in isolation from the complicating effect of myofiber regeneration. This system should be of use for testing methods of a leviating the myofiber degeneration which is common to mdx and

ISSN:0148-639X    

DOI:10.1002/mus.880140108

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

年代:1991

数据来源: WILEY

摘要:

AbstractElectrophysiologic diagnosis of unilateral meralgia paresthetica is usually assessed by side‐to‐side comparison of SNAP amplitudes, SNCVs, and SEP latencies following stimulation of lateral femoral cutaneous nerves. To determine the relevance for diagnosis of these tests and side‐to‐side comparison, the results were compared in patients with unilateral meralgia paresthetica and normal subjects. The long‐term outcome was also considered, in order to determine whether electrophysiologic findings contribute to the prognosis. In our study, SNAP amplitude comparison was found to be more useful for diagnosis than SNCV and SEP latency comparisons. However the value of the SNAP amplitude on the affected side, just as the results of the other tests, was not found to be predictive of the outcome. Also the results of the tests depend on the methods used and on the nerv

ISSN:0148-639X    

DOI:10.1002/mus.880140109

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

年代:1991

数据来源: WILEY

摘要:

AbstractWe have studied the water permeability through membranes, the function of the Na pump, and glucose metabolism of erythrocytes of patients with myotonic muscular dystrophy (MyD) using1H–,23Na, and13C‐NMR techniques. A significant decrease in water permeability was recognized in the MyD erythrocyte membrane, and impaired Na pumping was suspected to be correlated with the former biochemical abnormalities in band III protein of MyD erythrocyte membrane. Significant acceleration of glycolysis in the erythrocyte for the first 160 minutes was also recognized in MyD: however, the production of lactate showed no difference between MyD and controls. The increased glucose uptake in MyD may be compensatory to the diminished pumping mechanism, but further information, such as inorganic phosphate permeability and the activity of the rate‐limiting enzyme of erythrocyte glycosis, is n

ISSN:0148-639X    

DOI:10.1002/mus.880140110

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

年代:1991

数据来源: WILEY

摘要:

AbstractWe studied the discharge pattern of single motor units (SMUs) in the left and right biceps muscles from a patient with nonspastic weakness of the left arm. Detailed statistical analysis of the behavior of discharge patterns of 4 of 4 single motor units on the affected side showed abnormalities with characteristic features of an upper motor neuron lesion. Five out of 5 single motor units recorded from the right biceps were normal. An upper motor neuron lesion affecting the left arm, predicted by our results, was confirmed by magnetic resonance imaging (MRI), which showed a lesion in the right precentral gyrus. It appears that changes in single motor unit firing characteristics, caused by an upper motor neuron lesion, can be detected at a time when there is no evidence of increased “tone” and/or hyperreflexia (spasticity) in the affected extrem

ISSN:0148-639X    

DOI:10.1002/mus.880140111

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

年代:1991

数据来源: WILEY