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421.
O. Friedrich M. Both S. Schürmann F. von Wegner R.H.A. Fink J.S. Chamberlain 《Biophysical journal》2010,98(4):606-616
Progressive force loss in Duchenne muscular dystrophy is characterized by degeneration/regeneration cycles and fibrosis. Disease progression may involve structural remodeling of muscle tissue. An effect on molecular motorprotein function may also be possible. We used second harmonic generation imaging to reveal vastly altered subcellular sarcomere microarchitecture in intact single dystrophic mdx muscle cells (∼1 year old). Myofibril tilting, twisting, and local axis deviations explain at least up to 20% of force drop during unsynchronized contractile activation as judged from cosine angle sums of myofibril orientations within mdx fibers. In contrast, in vitro motility assays showed unaltered sliding velocities of single mdx fiber myosin extracts. Closer quantification of the microarchitecture revealed that dystrophic fibers had significantly more Y-shaped sarcomere irregularities (“verniers”) than wild-type fibers (∼130/1000 μm3 vs. ∼36/1000 μm3). In transgenic mini-dystrophin-expressing fibers, ultrastructure was restored (∼38/1000 μm3 counts). We suggest that in aged dystrophic toe muscle, progressive force loss is reflected by a vastly deranged micromorphology that prevents a coordinated and aligned contraction. Second harmonic generation imaging may soon be available in routine clinical diagnostics, and in this work we provide valuable imaging tools to track and quantify ultrastructural worsening in Duchenne muscular dystrophy, and to judge the beneficial effects of possible drug or gene therapies. 相似文献
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423.
Induced by the case of a blood-donor with more than 100 donations-mostly apheresis-who suffered acute thromboembolism caused by antithrombin III depletion, nearly 60 apheresis-donors were examined before, during and after aphereses, as well manual fourfold as computerized (CS-3000 TRAVENOL) cytaphereses with special methods of coagulation, mainly antithrombin III levels and fibrin-monomeres. The findings were described and compared, multifold in manual techniques happened breaks caused by occluded tubules were accompanied with decrease of antithrombin III and positive FM-tests. It was discussed, if apheresis-techniques for themselves (extracorporal multifold manipulation in manual techniques and contact with artificial surfaces in both kinds of techniques) can be the reason for a hypercoagulation. It seems to be important, how is the situation of apheresis-donor before starting, therefore we give the recommendation, to pay more attention in examination this kind of donors, additional with testing antithrombin III levels and tests for fibrin-monomers. 相似文献
424.
We have identified three genes, expressed in zebrafish embryos, that are members of the engrailed gene family. On the basis of sequence comparisons and analyses of their expression patterns, we suggest that two of these genes, eng2 and eng3, are closely related to the En-2 gene of other vertebrates. The third gene, eng1, is probably the zebrafish homolog of En-1. Subsets of cells at the developing junction between the midbrain and hindbrain express three different combinations of these genes, revealing a previously unknown complexity of this region of the CNS. Other cells, for example, jaw and myotomal muscle precursors, express two of the three genes in combinations which, in the myotomal muscles, change during development. Cells in the developing hindbrain and fins express only a single engrailed gene. We propose that the fates and patterning of these cells may be regulated by the coordinate expression of particular combinations of these closely related homeoproteins. 相似文献