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Biomedical subjects

J Davidowitz

Publications and source records attributed to J Davidowitz.

36 records · Page 2Linked to original sources
PubMed1976

Structural alterations of the junctional region in extraocular muscle of dystrophic mice. I. Modifications of sole-plate nuclei.

Sole-plate nuclei of the C57Bl/6Jdy2j dystrophic mouse showed apparent selective susceptibility to various forms of structural alteration. Pyknosis and chromatin fragmentation were seen in addition to vacuolar and membranous nuclear inclusions. These were often associated with neuromuscular junctions with markedly reduced or virtually absent junctional folding. Membranous proliferations also occurred nearby sole-plate nuclei of such flattened junctions.

Animals↗
PubMed1976

Structural alterations of the junctional region in extraocular muscle of dystrophic mice. II. Hypertrophy of the neuromuscular junctional apparatus.

The fine structure of end-plate abnormalities was studied in the Bar harbor C57Bl/6jdy2j dystrophic mouse. A marked increase in area and volume of junctional sarcoplasm was often apparent. Such hypertrophied end-plates were often penetrated by networks of axonal terminal branches. At times, pseudopod-like extensions of the junctional sarcoplasm encompassed and made protracted synaptic contact with the incoming axon. Such apparent remodeling of the neuromuscular apparatus might represent a compensatory cellular response to decreased impulse transmission efficiency, as might result from a flattening of the postjunctional folding seen on abnormal muscle fibers in these animals.

Animals↗
PubMed1976

Morphological fiber types of retractor bulbi muscle in mouse and rat.

Retractor bulbi muscles of mouse and rat were examined by light and electron microscopy. Two morphological fiber types were observed, analogous to Type I and Type II cells of skeletal musculature and comparable to fibers observed in the global region of the rectus extraocular muscles of these species.

Animals↗
PubMed1975

Particle-free and glycogen-bearing double membrane arrays in extraocular muscle of rabbit.

Smooth double membrane arrays were observed in apparently normal extraocular muscle. These were fully or partially glycogen bearing, or completely particle free. The respective structures were often closely associated. Comparable arrays have been reported in normal and pathologic muscle; in liver cells, particle-free and glycogen-bearing double membrane arrays are frequently seen under an assortment of abnormal conditions. The significance of such structures is not clear. The present observations suggest that particle-free arrays are related to those bearing glycogen and may thus be associated with anabolic functions.

Animals↗
PubMed1975

Muscle fiber and motor end plate involvement in the extraocular muscles of the myotonic mouse.

The extraocular muscles of the C57BL/6Jdy-2j myotonic mouse were studied by phase and electron microscopy. The most susceptible ocular muscle was the levator palpebrae; the other muscles manifested scattered abnormalities to varying degrees. Central nucleation and fiber splitting were prominent. Junctional abnormalities consisted of a reduction in post-junctional folding, excessive numbers of axonal terminals on hypertrophic fibers, and the presence of dense granules between axon and muscle. This study demonstrates the affection of both muscle fiber and motor end plate in mouse myotonic dystrophy.

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