摘要:

AbstractImmature fibers in Duchenne muscular dystrophy (DMD) and congenital muscular dystrophies (CMD) were compared with human fetal muscles and experimentally‐induced regenerating muscle fibers using the acridine orange (AO) technique on fluorescent microscropy and histochemical methods. Strong AO activity was observed on immature fibers in dystrophies and on experimentally‐induced fibers in the early stages of regeneration. These young fibers showed type 2C histochemical reactions on ATPase stains. Human fetal muscles failed to show these fibers which were seen in the muscular dystrophies and the experimental regenerating muscle. From these results it is concluded that immature fibers in muscular dystrophies are early stages of regenerating fibers and not maturationally arrested fetal muscle fibers. In addition, these immature fibers formed small groups composed of 10 to 50 fibers in muscular dystrophies and sometimes large groups in CMD. It is suggested that the investigation of immature fibers and their grouping is quite important for revealing the pathogenesis of the muscular dystroph

ISSN:0148-639X    

DOI:10.1002/mus.880060802

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe response of human muscle triceps brachii (TB) to training, which consisted of skiing with sledges 500 miles over a period of 36 days, has been investigated by means of histochemical fiber typing (myofibrillar ATPase,n= 7). Muscle biopsies were taken in the right TB during pretraining, and in the right as well as in the left TB after training. The percentage of type 2 fibers and intermediate fibers (type 2C and 1B) in the right TB decreased and increased, respectively, by 13%. The fiber type distribution in the left TB after training was very similar to that in the right TB after training. This concordance indicates that the change in fiber type distribution was a result of the training per se, and not related to any eventual effect of the biopsy‐samplin

ISSN:0148-639X    

DOI:10.1002/mus.880060803

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

年代:1983

数据来源: WILEY

摘要:

AbstractMuscle pyruvate metabolism was studied in rats following sciatic nerve crush. Control studies showed high pyruvate dehydrogenase and lipoamide dehydrogenase enzyme activity in muscle with type 1 fiber predominance (soleus) and low activities in muscle with type 2 fiber predominance (extensor digitorum longus), whereas lactate dehydrogenase was much higher in the latter. Following denervation, both muscles showed a significant reduction in pyruvate dehydrogenase enzyme activity. During reinnervation, muscle with type 2 predominance developed significantly elevated pyruvate oxidation enzyme activities.

ISSN:0148-639X    

DOI:10.1002/mus.880060804

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

年代:1983

数据来源: WILEY

摘要:

AbstractLumbar dorsal root ganglia were sampled at autopsy from 27 diabetics and 22 nondiabetics. Using quantitative ultrastructural morphometry, the perineurial cell basement membrane thickness was estimated for each case, and a highly significant difference was found between the patient means for each group (nondiabetics 114 ± 18 nm vs. diabetics 203 ± 64 nm,P<0.001). These results indicate that perineurial cell basement membrane thickening probably is present diffusely throughout the diabetic peripheral nervous system because it has been reported in the sural nerves and dermal nerves. The increased permeability of the blood‐nerve barrier of the dorsal root ganglia is apparently not a factor in the development of this basement membrane hypertro

ISSN:0148-639X    

DOI:10.1002/mus.880060805

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

年代:1983

数据来源: WILEY

摘要:

AbstractTwo‐dimensional crystalline arrays of the Ca2+transport ATPase develop after treatment of sarcoplasmic reticulum vesicles with Na3VO4. The dimensions of the crystal lattice are similar in sarcoplasmic reticulum membranes isolated from normal and genetically dystrophic human, mouse, and chicken muscles. These observations indicate similar requirements for ATPase‐ATPase interactions in sarcoplasmic reticulum of normal and dystrophic muscles and lessen the likelihood of a molecular defect of the Ca2+pump in the various forms of genetic muscular dystroph

ISSN:0148-639X    

DOI:10.1002/mus.880060806

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe absolute number of satellite cells (SC) in young and adult rat skeletal muscle was estimated by correlating data from light and electron microscopic quantitation of myofiber nuclei (myonuclei and satellite cell nuclei) with biochemical assays for determining total muscle DNA content. Expressed both as a proportion of total myofiber nuclei and as absolute numbers, satellite cells are more numerous in the predominantly oxidative soleus muscle than in the mixed glycolytic/oxidative extensor digitorum longus (EDL) muscle at 1, 12, and 24 months of age. Satellite cell proportions decline gradually in both muscles with advancing age, but absolute numbers increase significantly in the soleus between 1 and 12 months, while EDL exhibits a continuous significant decline in satellite cells between each of the ages examined.

ISSN:0148-639X    

DOI:10.1002/mus.880060807

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

年代:1983

数据来源: WILEY

摘要:

AbstractThere is a need for a practical and statistically manageable quantitative index of fiber type co‐dispersion in skeletal muscle to allow investigation of the distribution of motor units in normal muscle and their rearrangement in pathological states. A new measure for this purpose, the Co‐Dispersion Index (CDI), is introduced. This measure is based on contingency table analysis of nearest‐neighbor relationships between muscle fibers. The CDI has a continuous range of values from −1 to +1, in which larger negative values indicate a greater tendency toward regular intermixing of fibers of different types, and larger positive values a greater segregation of fiber types. CDI evaluation overcomes the limitations of previously published quantitative methods for codispersion measurement and is well correlated with subjective human estimates of fiber type g

ISSN:0148-639X    

DOI:10.1002/mus.880060808

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe effects of aging on the total number and size of fibers, and the proportion and distribution of type 1 (slow twitch) and type 2 (fast twitch) fibers were studied in cross sections (15 μ thick) of autopsied wholem. vastus lateralisfrom two age groups. Each group consisted of six, previously physically healthy males (mean age 72 ± 1 years and 30 ± 6 years, respectively). The size of the muscles of the older individuals was 18% smaller (P<0.01) and the total number of fibers was 25% lower (P<0.01) than those of the young individuals (mean number 364,000 ± 50,000 vs 478,000 ± 56,000). There was, however, no significant difference in the mean fiber size (indirectly determined) orthe proportion of the two fiber types, though a preferential reduction in type 2 fiber number in the aged individuals was seen. The relative occurrence of the fiber types at various depths in the aged muscles was found to be more even than in muscles from the young individuals. The results suggest that the aging atrophy inm. vastus lateralis, at least up to the age of 70, is primarily the result of a loss of fi

ISSN:0148-639X    

DOI:10.1002/mus.880060809

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe susceptibility to exercise‐induced myopathy was studied by histological and biochemical methods in various skeletal muscles of mice 3–4 days after a single bout of prolonged running. The degree of exercise injuries varied greatly in different muscles. Soleus and the red deep parts of quadriceps femoris were the most severely affected muscles. Extensive or scattered necrosis of muscle fibers was associated with focal inflammation and a five‐ to nine‐fold increase in the activity of β‐glucuronidase in these muscles. Slight necrotic changes and a two‐ to three‐fold increase in the activity of β‐glucuronidase were observed in tibialis anterior, plantaris, and the red deep parts of gastrocnemius. A statistically significant increase in β‐glucuronidase activity was also observed in the white distal part of quadriceps femoris, biceps femoris, gracilis, extensor digitorum longus, and peroneal muscles but necrotic lesions were infrequent in these muscles. The degree of exercise injuries is probably affected by the different recruitment of muscles during running and by the anatomical location of muscles in separate compartments, which could expose them to differnt levels of ischemic compression b

ISSN:0148-639X    

DOI:10.1002/mus.880060810

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

年代:1983

数据来源: WILEY

摘要:

AbstractEnd‐plate potentials were recorded from superficial muscle fibers of the frog sartorius nerve‐muscle preparation. Exposure of the preparation to a medium containing a high divalent cation concentration, produced a temperature dependent failure of neuromuscular transmission. Failure of transmission developed in an “all‐or‐none” mode and was reversed by decreasing the bath temperature or divalent cation concentration. This blockage of the neurotransmission is attributed to a presynaptic block of impulse

ISSN:0148-639X    

DOI:10.1002/mus.880060811

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

年代:1983

数据来源: WILEY