Linked Life Data

6287911

Source:http://linkedlifedata.com/resource/pubmed/id/6287911

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1982-10-12
pubmed:abstractText
Five familial cases (in two families) and one sporadic case of a new congenital myasthenic syndrome were investigated. Symptoms arise in infancy or later life. Typically, one finds selective involvement of cervical, scapular, and finger extensor muscles, ophthalmoparesis, and variable involvement of other muscles. There is a repetitive muscle action potential to single nerve stimulus in all muscles and a decremental response at 2 to 3 Hz stimulation in clinical affected muscles. Microelectrode studies reveal markedly prolonged end-plate potential (epp), miniature end-plate potential (mepp), and miniature end-plate current; normal quantum content of the epp; and a smaller than normal or low-normal mepp amplitude. Light microscopy demonstrates predominance of type I fibers, small groups of atrophic fibers, tubular aggregates and vacuoles near end-plates, abnormal end-plate configuration, and nonspecific myopathic changes. Abundant acetylcholinesterase activity is present at all end-plates, and the activity and kinetic properties of this enzyme in muscle are normal. Calcium accumulated at the end-plate in one patient. Quantitative electron microscopy shows decrease in the size of nerve terminals, increase in the density of synaptic vesicles, and reduction in the length of postsynaptic membranes. There is focal degeneration of junctional folds with corresponding loss of acetylcholine receptor, most marked in cases with the lowest mepp amplitude. There are no immune complexes at the end-plate. Fiber regions near end-plates display dilation, proliferation, and degeneration of the sarcoplasmic reticulum; nuclear, mitochondrial, and myofibrillar degeneration; and vacuoles resembling those found in periodic paralysis. A prolonged open time of the acetylcholine-induced ion channel is considered to be the basic abnormality and may account for the physiological, morphological, and clinical alterations.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0364-5134
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
553-69
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
A newly recognized congenital myasthenic syndrome attributed to a prolonged open time of the acetylcholine-induced ion channel.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Case Reports, Research Support, Non-U.S. Gov't