| 1. |
- Carlsson, Lena, et al.
(författare)
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Cytoskeletal derangements in hereditary myopathy with a desmin L345P mutation
- 2002
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Ingår i: Acta Neuropathologica. - : Springer. - 0001-6322 .- 1432-0533. ; 104:5, s. 493-504
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Tidskriftsartikel (refereegranskat)abstract
- Patients with abnormal accumulations of desmin have been described in myopathies with or without cardiac involvement. Desmin deposits were sometimes associated with abnormal aggregates of other cytoskeletal proteins. In the present study we present how the cytoskeletal organisation of desmin, nestin, synemin, paranemin, plectin and alphaB-crystallin is altered in skeletal muscles from a patient with a L345P mutation in the desmin gene. In general, accumulations of desmin together with synemin, nestin, plectin and alphaB-crystallin were present between myofibrils and beneath the sarcolemma. However, as the biopsy samples were very myopathic, large variability in fibre size and fibre maturation was seen, thus the myofibrillar content and the cytoskeletal organisation varied considerably. In cultured satellite cells from the patient, desmin aggregates were not observed in initial passages, but occurred over time in culture in the form of perinuclear, peripheral or cytoplasmic deposits. Nestin colocalised to the abnormal desmin deposits to a larger extent than did vimentin. alphaB-Crystallin was only present in cells with a disrupted desmin network. Plectin was altered in a subset of cells with a disrupted desmin network, whereas synemin and paranemin were not detected. We conclude that the L345P desmin mutation has a profound influence on the cytoskeletal organisation both in vivo and in vitro, which reflects the pathogenesis of the desmin myopathy.
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| 2. |
- Kadi, F., et al.
(författare)
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The effects of different training programs on the trapezius muscle of women with work-related neck and shoulder myalgia
- 2000
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Ingår i: Acta Neuropathologica. - Berlin : Springer Berlin/Heidelberg. - 0001-6322 .- 1432-0533. ; 100:3, s. 253-258
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to examine the effects of training on the structural characteristics of the trapezius muscle in women with work-related trapezius myalgia. Muscle biopsies were taken before and after 10 weeks of three different training programs (strength, endurance and coordination). Enzyme-immunohistochemical analysis was performed to assess muscle fibre types, fibre area, capillary supply and cytochrome c oxidase (COX) activity. There was an increase in the proportion of type LIA fibres in strength trained group (P < 0.05). Strength training elicited a preferential increase in the area of type II fibres (P < 0.05); both strength and endurance programs induced an increase in the number of capillaries around type I and IIA muscle fibres. Finally, all training programs induced a decrease in the proportion of COX-negative fibres. In conclusion, the trapezius muscle of women with neck and shoulder myalgia is characterised by a great potential of adaptation to physical exercise over a period of 10 weeks. The significant changes in the number of capillaries and the specific changes induced by training at the level of muscle fibres might well explain the improvement of muscle function.
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| 3. |
- Soukup, T, et al.
(författare)
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Intrafusal fiber type composition of muscle spindles in the first human lumbrical muscle
- 2003
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Ingår i: Acta Neuropathologica. - : Springer-Verlag New York. - 0001-6322 .- 1432-0533. ; 105:1, s. 18-24
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Tidskriftsartikel (refereegranskat)abstract
- We studied muscle spindles in the first lumbrical muscle of adult humans using myofibrillar ATPase (mATPase) activity. We found that muscle spindles exhibited a marked variability with respect to the number, position, length and detailed histochemical features of nuclear bag1, nuclear bag2 and nuclear chain fibers. Regarding mATPase activity, the nuclear bag2 fibers displayed lower alkali-stable mATPase activity along their length and many nuclear bag1 fibers tended to have lower acid-stable activity in the outer B region, whereas nuclear chain fibers exhibited medium acid-stable mATPase activity at pH 4.6. Almost 10% of spindle fibers displayed atypical features, as they were either located only at one spindle pole or exhibited mixed characteristics at either pole. The number of intrafusal fibers per spindle varied between 8 and 24. Strikingly, only 2 pairs from 22 muscle spindles had identical allotments of their intrafusal fibers. Muscle spindles in the first human lumbrical muscle contained more intrafusal fibers (12.3 +/- 4 per spindle on average) and especially relatively more nuclear bag fibers compared to other human skeletal muscles. Since each spindle apparently represents a unique morphological and physiological entity, the observed variability in the number and characteristics of intrafusal fibers in the first human lumbrical muscle likely reflects a wide range of finely tuned muscle spindle responses.
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