Search Results - (Author, Cooperation:P. Baatsen)

2016-03-25

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Carcinogenesis/genetics/pathology ; Cell Lineage ; Cell Proliferation ; Cell Survival ; Chromosomes, Human, Pair 3/genetics ; Clone Cells/metabolism/pathology ; Female ; Gene Amplification/genetics ; Gene Knockdown Techniques ; Humans ; Melanoma/*genetics/*pathology/therapy ; Mice ; Microphthalmia-Associated Transcription Factor/genetics ; Mitochondria/genetics/metabolism/pathology ; Mitochondrial Proteins/metabolism ; Mitogen-Activated Protein Kinases/antagonists & inhibitors/metabolism ; Molecular Targeted Therapy ; Oncogenes/*genetics ; RNA, Long Noncoding/*genetics/therapeutic use ; SOXE Transcription Factors/metabolism ; Xenograft Model Antitumor Assays

1573-2657

Springer Online Journal Archives 1860-2000

Biology

Medicine

Electronic Resource

1573-2657

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary Absence of dystrophin in mdx muscles may render the muscle more susceptible to damage when submitted to high stress levels. To test this, typically slow (soleus) and fast (EDL) limb muscles of dystrophic (mdx) and normal (C57BL/10) mice were submitted (in vitro) to a series of isometric contractions, followed by a series of contractions with stretches. Muscle injury was assessed by monitoring the force signal. Membrane damage was evaluated by bathing the muscle in Procion Red, a dye that does not penetrate intact fibres, and subsequent analysis by light microscopy. After isometric contractions, only a very small force drop (〈3% of maximal isometric force) was observed which indicated that no injury had occurred in soleus and EDL muscles in either mdx or C57 strains. After contractions with a stretch, a force drop of 10% was observed in soleus muscles from both strains and in EDL muscles from C57 mice. However, in mdx mice EDL muscles displayed an irreversible force drop of 40–60%. Histological analysis of the muscles indicates that force drop is associated with membrane damage. These results show that EDL muscles from mdx mice are more vulnerable than their controls, supporting the structural role hypothesis for dystrophin. Furthermore, they suggest that contractions with stretches may contribute to the muscle damage and degeneration observed in DMD-patients.

Electronic Resource

1573-2657

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary Tropomyosin localization in striated muscle was studied by means of immunoelectron microscopy. Polyclonal and monoclonal antibodies to tropomyosin were allowed to diffuse into mechanically skinned single fibres dissected from frog semitendinosus muscle. Antibodies produced transverse I-band stripes with the expected periodicity of 38 nm. However, some differences were revealed among the various antibodies. While polyclonal antibodies generally showed 23 stripes, monoclonal antibodies showed an extra 24th stripe immediately adjacent to the Z-line, implying some structural/functional uniqueness of this terminal tropomyosin. Furthermore, the stripes did not always lie parallel to the Z-line. When the Z-line was straight or slightly skewed, the stripes generally were parallel to it. However, when Z-line skew was more severe, the stripes remained perpendicular to the fibre axis, indifferent to the Z-line skew. This may imply that the coupling of tropomyosin to the thin filament is not tight. Finally, the monoclonal antibodies themselves exerted an anomalous effect on the Z-line, apparently extracting or shifting some of its mass.

Electronic Resource