Biomedical subjects

C J van den Oord

Publications and source records attributed to C J van den Oord.

3 recordsLinked to original sources

PubMed1990

Morphological changes in the human end plate with age.

We carried out a light and electron microscopic study on end plates and related structures in external intercostal muscles from subjects aged between 4 and 77 years. Light microscopically end plates maintained the same size, did not increase in number and showed no sprouting of terminal axons, all indicating that major compensatory histological changes to maintain adequate neuromuscular transmission with age were not required. At the ultrastructural level end plates became more complex mainly at the postsynaptic side. The latter included increased length and branching of the postsynaptic membrane with enlargement of the postsynaptic area, and degeneration of junctional folds. However, some neuromuscular junctions (NMJs) showed little branching of the postsynaptic membrane, even in old age. At the presynaptic side nerve terminals with an irregular shape were noted in the aged. Schwann cell processes were seen to intrude into the primary synaptic cleft. From these data we suggest that degeneration of the postsynaptic membrane with consequent focal denervation of NMJs is a primary event in the age-related changes of end plates. The muscle fibres showed a minor degree of type grouping in old age doubtless due to loss of motor neurons with age.

Adult↗

PubMed1989

A light and electron microscopical study of B-50 (GAP-43) in human intramuscular nerve and neuromuscular junctions during development.

The growth associated protein B-50 (GAP-43) is demonstrated in human intramuscular nerves and neuromuscular junctions by light microscopy and electron microscopy. Nearly all fetal endplates are shown to be immunoreactive for B-50. The percentage of B-50 positive endplates decreases significantly during the peri- and neonatal period, but in children and adults a low percentage of B-50 positive endplates remains present. These data indicate that also in the human peripheral nervous system the expression of B-50 is developmentally regulated.

Adult↗

PubMed1988

Histological investigations of muscle atrophy and end plates in two critically ill patients with generalized weakness.

We describe pathological alterations at the light microscopical and ultrastructural level of motor end plates and muscle fibres in 2 critically ill patients with generalized muscular atrophy and weakness. Axonal degeneration of intramuscular nerve fibres was not conspicuous. The sural nerve in one patient showed only minor abnormalities. There was a marked atrophy of type 1 and especially type 2 muscle fibres. Nodal and ultraterminal nerve sprouts were seen in both biopsies. Motor end plates showed features of regeneration. They were enlarged in one patient. This patient was treated for a prolonged period with vecuronium bromide. Pharmacological denervation may explain the presence of fibrillation potentials, and, partially, of the histological abnormalities. Another factor which must be considered is inhibition of neuromuscular transmission by antibiotics. In addition to disuse atrophy and a minor degree of axonal neuropathy, the production of muscle proteolytic factors may be involved in the rapidly occurring massive loss of muscle fibre size in critically ill patients.

Atrophy↗