ISSN:0148-639X    

DOI:10.1002/mus.880040603

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

年代:1981

数据来源: WILEY

摘要:

AbstractIn this review, our current knowledge on the structural proteins of vertebrate skeletal muscle is briefly outlined. Structural proteins include the contractile proteins (actin and myosin), the major regulatory proteins (troponin and tropomyosin), the minor regulatory proteins (M‐protein, C‐protein, F‐protein, l‐protein, and actinins), and the scaffold proteins (connectin, desmin, and Z‐protein). In addition, the relative turnover rates of the muscle proteins (M‐proteinactin) are discussed. The changes in the turnover of muscle proteins are compared in denervated and dystrophic muscles. The properties of the various proteases in muscle, including alkaline protease, calcium‐activated neutral protease (CANP), and acidic protease (cathepsins), and the structural alterations of myofibrils by these proteases are also described. Finally, the role of proteases and their inhibitors in diseased muscle is summarized, with focus on CANP and its inhibitors,

ISSN:0148-639X    

DOI:10.1002/mus.880040604

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

年代:1981

数据来源: WILEY

摘要:

AbstractIncreased [32P]‐incorporation in tryptic peptides of the erythrocyte membrane protein spectrin Band 2 in Duchenne muscular dystrophy (DMD) was studied in a consecutive series of 10 matched DMD/control pairs. Spectrin was [32P]‐phosphorylated by cyclic AMP‐independent endogenous membrane protein kinase in the presence of [γ‐32P]ATP. [32P]‐labeled spectrin was isolated, purified, and subjected to tryptic cleavage with excess trypsin. The resulting peptides were separated on a high‐resolution 5%/15% stacking SDS‐polyacrylamide gel electrophoresis system. Liquid scintillation counting was performed on sequential slices of unstained gels. A broad [32P]‐labeled band containing a number of [32P]‐polypeptides was found to be more highly [32P]‐phosphorylated in DMD patients than in their matched controls. This band migrated with an apparent molecular mass of 4.8–5.2 kilodaltons and contained approximately 55% of total [32P] radioactivity covalently bound to spectrin peptides. These data demonstrated an increased [32P]‐phosphorylation of an identifiable tryptic peptide fraction in DMD that is consistent with previous reports of increased spectrin Band 2 [32

ISSN:0148-639X    

DOI:10.1002/mus.880040605

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

年代:1981

数据来源: WILEY

摘要:

AbstractThirty‐eight patients with myokymic discharges localized to limb muscles on needle electromyography had various neurologic lesions, both acute and chronic. Of the 38 patients, 27 had had previous radiation therapy and the clinical diagnosis of radiation‐induced plexopathy, myelopathy, or both. For the remaining 11 patients, the diagnoses included multiple sclerosis, inflammatory polyradiculoneuropathy, ischemic neuropathy, inflammatory myopathy, and chronic disorders of the spinal cord and peripheral nerves. The clinical presentations and results of local ischemia, peripheral nerve block, and percutaneous stimulation suggest that most limb myokymic discharges arise focally at the site of a chronic peripheral nerve les

ISSN:0148-639X    

DOI:10.1002/mus.880040606

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

年代:1981

数据来源: WILEY

摘要:

AbstractAcetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were studied in the diaphragm of early postnatal rats, using radiometric determination of enzyme activities, velocity sedimentation for separation of molecular forms, and electron microscopic cytochemistry to localize enzymes. AChE activity did not change significantly during the first 2 months after birth. The level of 16 S AChE was high at early stages, but decreased to adult levels between days 19 and 32 after birth. In newborn and 8‐day‐old rats, 16 S and 13 S AChE were present in both endplate and extrajunctional muscle. In newborn muscle, BuChE activity was higher than AChE activity, but decreased 6‐fold by day 32. Newborn muscle contained 16 S, 10 S, and 4 S BuChE. The principal form throughout development was 4 S BuChE, but all forms diminished as total BuChE activity decreased with maturation. At early postnatal neuromuscular junctions, end product of both AChE and BuChE was present in the cleft, as well as in Schwann cells. More Schwann cells were present in early stages than in later stages, and this might account for part of the later decrease of BuChE activity measured biochemi

ISSN:0148-639X    

DOI:10.1002/mus.880040607

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

年代:1981

数据来源: WILEY

摘要:

AbstractMitochondrial preparations derived from denervated rat skeletal muscle and paired control muscle are characterized with respect to their oxidative and phosphorylative capacities. Our data indicate that there is an impairment within the first 2 energy coupling regions of the respiratory chain and within the ATPase complex itself.

ISSN:0148-639X    

DOI:10.1002/mus.880040608

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

年代:1981

数据来源: WILEY

摘要:

AbstractEven when all known factors affecting the determination of nerve conduction velocity are controlled, large individual variations persist. In 40 normal controls, we found that peroneal and sural conduction velocities varied inversely with body height (P<0.001). This height effect is not due to temperature differences, and it explains almost 50% of the intersubject variability in conduction velocity. We hypothesize that the height influence reflects abrupt, rather than gradual, tapering of axons distally. This mode of tapering may help explain the decrements in conduction velocity from proximal to distal nerve segments and from upper to lower extremities, which have long been observed in clinical electromyography. Clinical recognition of this height effect is important lest one label as abnormal an individual with mildly slowed peripheral nerve conduction velocity solely related to large stature.

ISSN:0148-639X    

DOI:10.1002/mus.880040609

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

年代:1981

数据来源: WILEY

摘要:

AbstractPatients who have suffered an acute attack of poliomyelitis may develop a clinically evident progression of weakness later in life. A syndrome known as forme fruste amyotrophic lateral sclerosis occurs in severely affected older polio patients. Neither process is well understood. Ten subjects who had had polio at least 22 years prior to examination and had no complaints of rapid progression of weakness were studied. Single‐fiber recordings were made from the extensor digitorum communis or the tioialis anterior muscle. Fiber densities were increased in all patients. Eight of 10 patients showed marked abnormalities in jitter in more than 50% of the recordings examined. There was a significant association between the percentage of recordings with abnormal jitter and the time since the attack of polio. Blocking was seen in more than 30% of the recordings examined in 6 of 10 patients. There was a significant association between the percentage of recordings demonstrating blocking and both the chronological age and the number of years since the attack of polio. These abnormalities may represent disintegration with aging in the reinnervated motor unit

ISSN:0148-639X    

DOI:10.1002/mus.880040610

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

年代:1981

数据来源: WILEY

ISSN:0148-639X    

DOI:10.1002/mus.880040611

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

年代:1981

数据来源: WILEY

ISSN:0148-639X    

DOI:10.1002/mus.880040613

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

年代:1981

数据来源: WILEY