摘要:

AbstractA large kinship with an autosomal hereditary‐motor‐and‐sensory‐neuropathy (HMSN) form of Charcot‐Marie‐Tooth disease (CMTD) is described. The affected members have the clinical features and reduced motor nerve conduction velocities of the hypertrophic type of CMTD, or HMSN I. Biopsies of the sural nerves of five affected members showed a large variability of demyelination and remyelination and onion bulb formation, independent of axonal atrophy and the severity of the disease. These findings are discussed in relation to recent

ISSN:0148-639X    

DOI:10.1002/mus.880050303

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

年代:1982

数据来源: WILEY

摘要:

AbstractIn order to determine whether branched‐chain ketoacids can reduce the excessive rate of muscle protein degradation that characterizes Duchenne muscular dystrophy, nine boys affected with the disease were studied in a metabolic ward while receiving meat‐free diets. After a three‐day equilibration period, excretion rates of 3‐methylhistidine and creatinine were measured in two consecutive four‐day periods. In the second period, a supplement containing a mixture of ornithine α‐ketoisocaproate, α‐ketoisovalerate, and α‐keto‐β‐methylvalerate in a proportion of 4 : 1 : 1 was administered orally at a dosage of 0.45 gm/kg/day. During treatment with the ketoacids, 3‐methylhistidine excretion fell by a small (mean: 14%) but highly significant (P<0.01) extent, whether expressed in absolute terms or in relation to creatinine excretion. No adverse effects were noted. We conclude that this mixture of ketoacids acutely reduces muscle protein degradation in patients with Du

ISSN:0148-639X    

DOI:10.1002/mus.880050304

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

年代:1982

数据来源: WILEY

摘要:

AbstractElectromyographic potentials of fasciculations were studied in ten patients with amyotrophic lateral sclerosis (ALS). The EMG recordings were made from the extensor digitorum brevis muscle. The EMG recording was so selective that only one motor unit potential appeared on maximal voluntary effort and on supramaximal electrical stimulation of the peroneal nerve. In a series of fasciculations, the shapes of the EMG potentials varied, while in a series of voluntary twitch activations of electrical nerve stimulations the EMG potentials were mainly constant. Fasciculations were followed by antidromic impulses in the test unit axon as judged from collision tests, and they persisted after lidocaine blockades of the nerve to the muscle. The findings are compatible with a conclusion of distal multifocal triggering of fasciculation. Fasciculating motor units had voluntary firing properties close to those of normal low‐threshold motor units. Widespread fasciculations were abolished by a nonparalytic dose of a synthetic curare derivative (Pavulon) and augmented by administration of neostigmine in two cases. The fasciculations in ALS thus have the same characteristics as experimental fasciculations evoked by cholinesterase inhibitors, and there is reason to believe that the underlying pathophysiological mechanism is similar in the two case

ISSN:0148-639X    

DOI:10.1002/mus.880050305

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

年代:1982

数据来源: WILEY

摘要:

AbstractFocal lesions in the plasma membrane overlying wedge‐shaped defects in muscle fibers (“delta lesions”) are an early pathological change in Duchenne muscular dystrophy (DMD). Abnormalities in the plasma membrane have been suggested as a cause of these lesions and of the degeneration of muscle fibers in DMD. We investigated the role of plasma membrane defects in the production of delta lesions by examining the effects of a series of membrane‐active agents—lysolecithin, deoxycholate, Triton X‐100, and melittin—on the muscles of rats in vivo. Within minutes after treatment with these agents, the muscle fibers developed typical delta lesions. Identical morphological changes were produced by the calcium ionophore A23187, suggesting that calcium entry may play an important role in this process. We conclude that damage to the plasma membrane or calcium entry can reproduce characteristic features of the muscle pathology seen in DMD. This model should prove useful in elucidating the mechanisms of muscle fiber damage and degene

ISSN:0148-639X    

DOI:10.1002/mus.880050306

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

年代:1982

数据来源: WILEY

摘要:

AbstractIn a study of 71 patients with myasthenia gravis, the local fiber density of muscle fibers within motor units was estimated with single fiber electromyography (SFEMG). The fiber density was increased significantly in the patient group, compared to normal controls. This increase was not correlated to disease severity or duration, but was significantly higher in patients treated with cholinesterase inhibitors as compared to untreated patients. The study indicates a slight reorganization of the motor unit in untreated patients with myasthenia gravis and more pronounced changes in patients treated with cholinesterase inhibitors.

ISSN:0148-639X    

DOI:10.1002/mus.880050307

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

年代:1982

数据来源: WILEY

摘要:

AbstractMany of the histological characteristics of neuromuscular disorders, including central core lesions and nemaline rods, can be produced experimentally by tenotomy of the soleus muscle in the rat. Using the freeze fracture technique, a decrease in the number of intramembrane particles of both the P and E faces of the plasma membranes of tenotomized soleus muscle fibers was observed. While many of the degenerative changes which occur after tenotomy are known, the causes of the degeneration are still unknown. The decrease in intramembrane particles may reflect some significant change in the function of the plasma membrane resulting in the appearance of the degenerative changes which follow tenotomy.

ISSN:0148-639X    

DOI:10.1002/mus.880050308

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe evaluation of palmitate oxidation in muscle tissue may be a useful screening test for detecting defects in fatty acid metabolism in human neuromuscular disease. If the test is to be useful, it is necessary to obtain data on a wide variety of muscle illnesses for comparative purposes. We report our experience with palmitate oxidation, muscle carnitine, and carnitine palmityl transferase (CPT) activity in 148 muscle biopsies from a variety of illnesses. The efficacy of using total protein, citrate synthase, and (1‐14C) pyruvate oxidation as internal references was investigated. Palmitate oxidation was significantly less than normal (P≤ 0.01) in Duchenne muscular dystrophy, congenital nonprogressive myopathy, congenital muscular dystrophy, malignant hyperpyrexia, and denervation, depending on the internal reference used. Muscle carnitine levels followed a similar pattern, however, CPT activity did not. The possibility of these findings being secondary to inactivity is discus

ISSN:0148-639X    

DOI:10.1002/mus.880050309

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe influence of testosterone on neuromuscular transmission was studied in levator ani (LA) and extensor digitorum longus (EDL) muscles taken from normal rats, castrated rats, and castrated rats treated with testosterone. Thirty days after castration LA muscle weights were reduced by 60%, but the frequency and amplitude of the miniature end‐plate potentials (mepps) were increased by 40% and 50%, respectively. The weights and mepp frequencies of the EDL muscles were not altered after castration, but the mepp amplitudes increased by 30%. The quantal content of the endplate potentials was not affected in either muscle. Administration of testosterone to the castrated rats prevented such changes in the LA muscles. The results indicate that castration of adult rats affects the spontaneous transmitter release in both muscles, but the changes are more pronounced in the levator ani, which is a target muscle for testosteron

ISSN:0148-639X    

DOI:10.1002/mus.880050310

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe structure of striated muscle (thick and thin filaments, filament lattice, and collagen), peripheral nerve myelin, and tendon collagen were studied in tissues from dystrophic and normal mice using small‐angle x‐ray diffraction. There were increases in the amount of disorganized tissue in the dystrophic mice, and the time course of the changes was monitored over the first 42 weeks of life. As the dystrophic mice became older, the contractile apparatus of the muscles appeared to atrophy, while the amount of collagen increased. In general, the molecular structure and packing appeared to remain unchanged as the disease progressed, although changes in the relative amounts and the organization of proteins were noted. In both normal and dystrophic mice, the collagen periodicity (65.7 nm) was 2% smaller when detected in muscle tissue compared with that detected in tendon tis

ISSN:0148-639X    

DOI:10.1002/mus.880050311

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

年代:1982

数据来源: WILEY

摘要:

AbstractFour cases are described in which the patients developed an isolated lesion of the median nerve in the proximal part of the arm during sleep. In the three patients that were available for follow‐up the course was favorable with complete recovery in several months. The causes of the lesions are unknown; several factors that could have played roles in causing the lesions are discusse

ISSN:0148-639X    

DOI:10.1002/mus.880050312

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

年代:1982

数据来源: WILEY