GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Morphometry  (3)
  • Reinnervation  (3)
  • 1
    ISSN: 1432-2307
    Keywords: Muscle spindle ; Elastic fibres ; Elaunin fibres ; Oxytalan fibres ; Denervation ; Reinnervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Muscle spindles in the lower lumbrical muscles of rats were studied by transmission electron microscopy following denervation with or without reinnervation. The number and total area of elastic fibres per muscle spindle increased at 3–12 months following various experimental procedures: (1) denervation and reinnervation after a single crush lesion to the sciatic nerve; (2) reinnervation after four-fold repeated crush injuries; and (3) transection and suture of the nerve. The increased number of oxytalan and elaunin fibres, the precursors of mature elastic fibres, within these muscle spindles provided further evidence for their numerical and dimensional increase. An attachment site of elastic fibres at the spindle pole was identified at the inner cells of the outer spindle capsule. The processes of these cells embraced terminating elastic fibres tightly. Attachment of elastic fibres to intrafusal muscle fibres was less conspicuous since they were not similarly embraced but were rather indistinctly, though closely, associated with the basal lamina along longitudinal surface indentations of intrafusal muscle fibres. It is concluded from this series of experiments that muscle spindles, as dynamic mechanoreceptors, maintain their elastic properties even under pathological conditions. The increase of elastic fibres following denervation and reinnervation represents an obviously meaningful reaction that may compensate for loss of tonic properties of muscle spindles without causing stiffness.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 80 (1990), S. 163-171 
    ISSN: 1432-0533
    Keywords: Neuromuscular spindle ; Reinnervation ; Nerve endings ; Autonomic innervation ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Muscle spindles from the lower lumbrical muscles of rats were studied by transmission and scanning electron microscopy following reinnervation (i) after a single sciatic nerve crush lesion and (ii) after transection and immediate epineurial suture of the sciatic nerve. In all muscle spindles, regenerated sensory or motor nerve endings were encountered 3 months after making the lesions although in the nerve-transection group, regenerated nerve endings were seen less frequently before 6 months of recovery. Abnormalities in reinnervated spindles following neurotomy comprised: (1) multiplicity of axonal sprouts (hyperinnervation), sometimes irregularly related to, although never in direct contact with, regenerated sensory nerve endings; (2) altered contact relationships between sensory nerve endings and intrafusal muscle fibers; (3) abnormal structure of nerve endings; and (4) irregular association of Schwann cell processes to regenerated sensory nerve endings. These findings indicate that reinnervation of muscle spindles following transection and suture of a peripheral nerve, i.e., after complete interruption of its continuity, in fact, occurs although the fine structural abnormalities observed are supposed to interfere with adequate functional restoration.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0533
    Keywords: Key words Schwann cell inclusions ; Demyelination ; Myelinated nerve fibers ; Morphometry ; Peripheral ; neuropathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In the cytoplasm of Schwann cells of a sural nerve biopsy from a 21-year-old female patient with chronic neuropathy we noted numerous unique, usually double membrane-bound, osmiophilic, granular or globular inclusions, approximately 30–600 μm in diameter. Some of these membrane-bound vesicular or tubular structures contained less dense or no osmiophilic inclusions. Morphometry revealed a reduction of the myelin area per endoneural area to approximately 13% (normal value: 20– 30%) and of the density of myelinated nerve fibers to 5,412/mm2 (normal value at this age: 6,000–9,000/mm2). Large myelinated nerve fibers were predominantly reduced in number, and no myelinated nerve fibers with diameters larger than 4.5 μm were seen. Numerous, usually small onion bulb formations indicated a predominantly demyelinating type of neuropathy. This is to the best of our knowledge the first case of a chronic demyelinating neuropathy in which this kind of presumably pathognostic deposits in the cytoplasm of Schwann cells was detected.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 99 (2000), S. 39-47 
    ISSN: 1432-0533
    Keywords: Key words Sural nerve ; Muscle fiber diameter ; Morphometry ; Electron microscopy ; Myotonic ¶dystrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We compared peripheral nerve fibers and muscle fibers in myotonic dystrophy (MD) using a computer-assisted device for morphometry. In the 17 cases with MD studied, the sural nerves of 14 cases (82%) showed various degrees of reduction of the myelin sheath area (MSA) per endoneurial area. Of these, 8 cases (47%) presented with a mild reduction of the MSA, 5 cases (29.4%) with moderate reduction, and one case (6%) with severe reduction. The number of myelinated nerve fibers was not significantly reduced in MD when compared with control nerves, due to clusters of small regenerated nerve fibers. The mean diameter of the muscle fibers in 6 of the 17 cases was less than 40 μm. Of these 6 severely affected cases, ¶5 revealed a considerable reduction of the MSA. Other cases, which appeared to be normal in respect to the diameter of muscle fibers, showed various degrees of reduction of the MSA. Thus, there is usually, but not always a morphometric correlation of the severity of changes between peripheral nerves and muscle. The severity of the peripheral neuropathy appears to depend largely on the patient’s age, the stage of the disorder, and the time of progression. Electron microscopic examination of sural nerves showed significant, though non-specific pathological changes.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0533
    Keywords: Muscle spindle ; Denervation ; Reinnervation ; Muscle fiber atrophy ; Mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of normal, denervated, and reinnervated muscle spindles in lower lumbrical muscles of rats was studied morphometrically at time intervals ranging from 3–14 months. In control spindles, the mean transverse area of mitochondria was estimated to be more than twice as large in nuclear chain than in typical nuclear bag fibers. Following denervation, there was a severe decrease of the mean number and transverse area of mitochondria, and a moderate, but statistically significant decrease of the mean transverse area of intrafusal muscle fibers (IMFs) despite an increase of the number of IMFs. At 12–14 months of reinnervation, changes of the transverse areas of IMFs were statistically insignificant, but the mean values for the mitochondria were incompletely restored. At 4×3 months, after fourfold repeated crush injuries to the nerve, most of the values estimated (transverse area of mitochondria; number, shape, and transverse area of IMFs and nuclei) tended to approach those in denervated rather than in reinnervated IMFs. The differences of the reactions of intra- and extrafusal muscle fibers following complete motor and sensory denervation appeared to be in accordance with their normal dimensional dissimilarities.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-1459
    Keywords: Ethylene oxide ; Peripheral neuropathy ; Morphometry ; Electron microscopy ; Demyelination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case is reported of ethylene oxide polyneuropathy after 5 months of exposure. There was symmetrical distal weakness of both lower extremities and transitory reduced nerve conduction velocities with increased latencies. Sural nerve biopsy revealed nerve fibre degeneration of the Wallerian type, associated with reduction of axonal cross-sectional areas and some degree of nerve fibre regeneration that could be confirmed morphometrically. In addition, there was conspicuous paranodal vesicular disintegration of individual myelin lamellae. Unusual cisternae with introverted hemidesmosomes were noted in endoneurial fibroblasts.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...