摘要:

AbstractRats and guinea pigs were injected with 2,4‐dichlorophenoxyacetate (2,4‐D) in amounts sufficient to keep them myotonic for over 12 hr daily. The biceps brachii muscles were studied by histochemistry, epoxy resin histology, and electron microscopy after one to five days. Changes observed include proliferation of the longitudinal component of the sarcoplasmic reticulum, production of new myofilaments on the periphery of cells and in nuclei, activation of satellite cells, accumulation of lipid droplets, myofibrillar damage with Z‐disc streaming, necrosis, and regeneration. The action mechanisms of 2,4‐D are not well understood. Some of the phenomena observed could be classified as proliferative and may be analogous to the auxin action of 2,4‐D in plants. The production of intranuclear filaments is probably related to the diffusion of newly formed cytoplasmic proteins in

ISSN:0148-639X    

DOI:10.1002/mus.880010202

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

年代:1978

数据来源: WILEY

摘要:

AbstractA patient with a long history of exercise‐induced pain developed myoglobinuria and respiratory failure following extensive exercise (football). Although muscle histochemistry was normal, tissue oxidation of14Clabeled palmitate was decreased, and muscle carnitine palmityltransferase (CPT) activity was one‐tenth of normal. During fasting, his creatine kinase (CK) rose from 127 mu/ml to 278 mu/ml and blood ketones failed to exhibit a normal rise. Triglycerides were normal, as was fatty‐acid mobilization. Prolonged exercise resulted in an inordinately increased CK with only moderate elevations in lactate. Treatment with medium‐chain triglycerides did not alter his symptoms or improve exercise performance. Pain on exercise is a common complaint, but the occurrence of myoglobinuria points to a defect of energy metabolism. Screening for defects of fat utilization may be accomplished by the prolonged‐exercise test, invitro oxidation of14C‐labeled substrates, and prolon

ISSN:0148-639X    

DOI:10.1002/mus.880010203

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

年代:1978

数据来源: WILEY

摘要:

AbstractThis is a review of clinical, cardiologic, electrophysiologic, pathologic, and serum creatine kinase changes in eight families with slowly progressive X‐linked Becker‐type muscular dystrophy. All but one of the patients were able to walk until the age of 16 years, and most lived beyond 20. In every family, electromyography and muscle biopsy showed features which, on the basis of classical criteria, were interpreted as those of both myopathy and denervation, although among patients and among families, one or the other of these processes predominated. The most frequent biopsy picture was of fiber atrophy and hypertrophy, with many split and angulated fibers, and clumps of pyknotic nuclei. Necrosis, phagocytosis, regeneration, endomysial fibrosis, and some fatty infiltration were commonly seen. Review of a family originally described by Becker showed a similar biopsy picture. These pathologic changes are separable from those of Duchenne muscular dystrophy, but they often overlap with those seen in other chronic neuromuscular disea

ISSN:0148-639X    

DOI:10.1002/mus.880010204

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

年代:1978

数据来源: WILEY

摘要:

AbstractA quantitive study of the terminal innervation ratio (TIR) was conducted using 18 amyotrophic lateral sclerosis (ALS) and 12 Charcot‐Marie‐Tooth disease (CMT) muscle biopsies. Morphometric and histochemical analyses of muscle fibers were performed in 9 ALS and 6 CMT biopsies. The results revealed that TIR and type grouping were significantly greater in CMT than in ALS. The proportion of type 3 fibers was higher in ALS, though the proportion of intermediate and type 0 fibers was significantly higher in CMT. The atrophy factor was significantly greater in type 3 than in types 1 and 2 fibers, but it was not significantly different in type 0 and intermediate fibers as compared to types 1 and 2. It appears, therefore, that CMT has a better capacity for collateral reinnervation than ALS. Type 0 and intermediate fibers may represent altered endproducts of successful collateral reinnervat

ISSN:0148-639X    

DOI:10.1002/mus.880010205

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

年代:1978

数据来源: WILEY

摘要:

AbstractAntisera to acetylcholine receptor purified from the electric organs of Torpedo and Electrophorus were highly species specific, but showed limited cross‐reaction with receptors from all mammalian species tested. Antisera to receptor purified from rat muscle cross‐reacted extensively with receptor from the muscles of other mammals. Antibodies to receptor from Electrophorus cross‐reacting with receptor from Torpedo were affinity purified. Subsequently these showed increased cross‐reaction with receptor from mammalian muscle. Sera from patients with myasthenia gravis reacted best with receptor from human muscle, but such sera also cross‐reacted with receptor from other mammals, especially squirrel monkeys. These sera cross‐reacted slightly with receptor from Torpedo, but not detectably with receptor from El

ISSN:0148-639X    

DOI:10.1002/mus.880010206

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

年代:1978

数据来源: WILEY

摘要:

AbstractNeonatal rats born of and nursed by mothers immunized with Torpedo acetylcholine receptor protein developed a defect of neuromuscular transmission as indicated by reduced miniature endplate potential amplitudes. It is likely that antibodies to the Torpedo receptor protein were passively transferred to the neonates in the milk. With the exception of the route of transfer, this neonatal from of experimental autoimmune myasthenia gravis appears to be similar to its human counterpart, and thus can serve as an experimental model.

ISSN:0148-639X    

DOI:10.1002/mus.880010207

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

年代:1978

数据来源: WILEY

摘要:

AbstractA review of our current knowledge of the etiology and pathogenesis of myasthenia gravis is presented, with particular emphasis on the immunological aspects of the disease. Part 1, published in the January/February issue of MUSCLE&NERVE, dealt with the clinical and genetic features of myasthenia gravis which led to the autoimmune theory of the etiology of the disease. Part 2, which appears in this issue, provides a review of the dysfunction of physiology, pharmacology, and structure of the neuromuscular junction in myasthenia gravis, and the part played by the autoimmune process.

ISSN:0148-639X    

DOI:10.1002/mus.880010208

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

年代:1978

数据来源: WILEY

摘要:

AbstractThe activities of choline acetyltransferase (CAT) and acetylcholinesterase (AChE) were assayed in various tissues of dystrophic (dy/dy) and normal mice of Bar Harbor strain 129. The brain weights of these dystrophic mice were not significantly different from those of normal mice, but the average body weight of these dystrophic mice was only 66.8% of that of the controls. The activity of CAT (expressed as unit activity per mg of protein) was very similar in the brains of both groups of animals, but the CAT activity (per mg of protein) in the hindlimb muscles of the dystrophic mice was significantly higher than that of the controls. The patterns of AChE activity, as separated by sucrose density gradient centrifugation, were distinctly different in extracts of dystrophic and normal muscle. Compared with controls, decreased activity of the 15‐S and 10‐S forms of AChE, with increased activity of a 4.3‐S forrn of AChE, was observed in dystrophic m

ISSN:0148-639X    

DOI:10.1002/mus.880010209

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

年代:1978

数据来源: WILEY

摘要:

AbstractAn electrophysiologic technique for studying sensory fibers in the rat sural nerve is described. The conduction velocity of the sural nerve in rats is much slower than in humans, probably because of the lack of large myelinated nerve fibers in rats. An experimental neuropathy (induced by hexachlorophene) that predominantly causes a myelin disorder produced a slowing of sural nerve conduction velocity and a potential of normal amplitude and duration. An experimental neuropathy (induced by zinc pyrithione) that primarily causes axonal degeneration produced a sensory potential of lower amplitude and shorter duration that had a normal conduction velocity.

ISSN:0148-639X    

DOI:10.1002/mus.880010210

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

年代:1978

数据来源: WILEY

摘要:

AbstractPeripheral neuropathy and hypertension caused by lead intoxication are reported in two children with sickle cell anemia. One child had generalized weakness in the initial occurrence and distal paralysis during a relapse two years later. The second child had foot and wrist drop. Both had slow peripheral nerve conduction velocities during the episodes. Chelation therapy was successful and resulted in a return of strength (over a period of several months) and a normalization of the blood pressures. Children with sickle cell anemia who are subjected to lead intoxication appear to be predisposed to peripheral nerve damage.

ISSN:0148-639X    

DOI:10.1002/mus.880010211

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

年代:1978

数据来源: WILEY