Related Experiment Videos
Intranuclear inclusions in a myopathy of late onset
Abstract:
Filamentous intranuclear inclusions in a case of myopathy of late onset are described. The filaments were usually in parallel array although occasionally they were haphazardly arranged in bundles ranging up to 5 mu in length. The filaments were approximately 120 A in diameter and were separated by a space measuring 180-220 A. Possible explanations of their occurrence in the nucleoplasm are discussed, including possible origin from the cytoplasm as a result of invagination of nuclear membrane and intranuclear entrapment of myofibrils from the cytoplasm. Their appearance does not suggest any recognizable structure such as myofilaments or virus. It is possible that the filaments are protein newly synthesized as a direct result of virus infection with invasion of the nuclei of the muscle cell.
Insights
This study describes unusual filamentous intranuclear inclusions found in late-onset myopathy. These filaments, approximately 120 Å in diameter, may represent newly synthesized proteins possibly linked to viral infection.
Area of Science:
- Neurology
- Cell Biology
- Pathology
Background:
- Myopathies can present with diverse cellular abnormalities.
- Intranuclear inclusions are observed in various neuromuscular disorders.
- The specific nature and origin of filamentous intranuclear inclusions require elucidation.
Purpose of the Study:
- To describe the morphology and arrangement of filamentous intranuclear inclusions in a patient with late-onset myopathy.
- To discuss potential origins and implications of these inclusions within the muscle cell nucleus.
Main Methods:
- Light and electron microscopy were used to examine muscle biopsy samples.
- Morphometric analysis of the filamentous inclusions was performed.
Main Results:
- Filamentous intranuclear inclusions were observed, typically arranged in parallel arrays.
- Filaments measured approximately 120 Å in diameter with inter-filamentous spacing of 180-220 Å.
- Inclusions did not resemble known structures like myofilaments or viruses.
Conclusions:
- The observed filaments may be de novo synthesized proteins, potentially related to viral infection.
- Possible origins include cytoplasmic invagination or intranuclear entrapment of myofibrils.
- Further investigation is needed to confirm the etiology of these inclusions.