Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pathological changes of the fusimotor endings in parkinsonism, motor neuron disease and myasthenia were examined by the acetylcholinesterase technic on serial sections. In parkinsonism, the diffuse endings, which are thought to be supplied by the static gamma nerve fibers, showed remarkable enlargement, while en plaque and en grappe endings were atrophic. In motor neuron disease, en plaque and en grappe endings, which are thought to be innervated by the beta nerve fibers and dynamic gamma nerve fibers respectively, revealed marked atrophy. However the diffuse endings were normal. In myasthenia gravis and myasthenic syndrome (Eaton-Lambert syndrome), en plaque and en grappe endings were atrophic, though only the diffuse endings were spared. The significance of these changes in the fusimotor endings is discussed.
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PMID:Histochemical study of the muscle spindles in parkinsonism, motor neuron disease and myasthenia. An examination of the pathological fusimotor endings by the acetylcholinesterase technic. 8 59

The effect of thoracic duct lymph drainage (5-34 days) in 12 patients with myasthenia gravis on muscular function has been followed for 5-43 months. Among the results obtained were: (1) During the drainage the myasthenic symptoms decreased markedly after 1-4 days and remained so during the drainage. (2) The doses of cholinesterase inhibitors had to be markedly reduced during the lymph drainage in eight patients. (3) Discontinuation of the lymph drainage increased the myasthenic symptoms within a few days. However, after a median observation time of 14 months with conventional treatment all but one of the patients had improved. (4) Retransfusion of the patients own cell-free lymph caused a worsening of the myasthenic symptoms. This effect could also be obtained following infusion of IgG preparations from the patients lymph. Three retransfusions of cell suspensions obtained from the thoracic duct lymph from two patients had no effects on their myasthenic symptoms. (5) It is suggested that thoracic duct lymph drainage can be combined with other forms of treatment in severe cases of myasthenia gravis.
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PMID:Drainage of thoracic duct lymph in twelve patients with myasthenia gravis. 16 80

Rabbits were immunized versus either an acetylcholinesterase- or a cholinergic receptor-rich fraction isolated from the electric organ of Torpedo marmorata. In both groups of animals we obtained a production of specific antibodies detected by immunodiffusion without cross reaction for the two antigens. Only rabbits immunized with the receptor-rich fraction developed a progressive flaccid paralysis, which affected first the leg muscles, progressively the neck muscles and eventually the respiratory muscles. The paralysis lasted in several animals up to 20 days. Eserine reversed the paralysis only in the first days but was ineffective in the "chronic" stage of the disease. In these animals high frequency stimulation of sciatic nerve induced a rapid failure of the responses of the anterior tibialis muscle while the muscle responded normally to a direct stimulation. A period of rest allowed a complete recovery of the muscle from fatigue. Tetani did not evoke the post-tetanic potentiation. Abnormalities, such as lymphocytic infiltration, fibers atrophy and necrosis, smearing and widening of Z line were sometimes present in muscles of Cho-R-immunized rabbits. In ACh-E immunized animals the neuromuscular transmission and the muscle morphology were similar to that of normal animals. Glycogen, ATP, cytochrome C oxidase, phosphorylases and acetylcholinesterase did not change significantly in the muscles of the immunized animals, while a large increase of cholineacetyltransferase activity was present. Red blood cell acetylcholinesterase showed a particularly high activity in ACh-E-immunized animals. The autoimmune paralysis induced in Cho-R-immunized rabbits may be a useful experimental model for further studies on human myasthenia gravis.
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PMID:Immunization of rabbits with secific components of postsynaptic membrane. Acetylcholinesterase and cholinergic receptor. 18 67

Rabbits injected with purified acetylcholine (ACh) receptor protein produce antibodies against the receptor and develop generalized muscle weakness. The compound muscle action potentials show a decremental fall in amplitude with repetitive nerve stimulation. Both the weakness and the decrement is counteracted by reversible cholinesterase inhibitors. Intracellular recordings from muscle endplates show that the amplitude of the miniature end-plate potentials is considerably reduced. A reduced binding of neurotoxin to muscles from immunized rabbits was observed. Nerve impulses release a normal number of ACh packages (quanta) from the motor nerve terminals. The muscle weakness in immunized rabbits thus has the same features as the muscle weakness in myasthenia gravis and may be a good animal model of myasthenia gravis.
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PMID:Acetylcholine receptor protein. Neuromuscular transmission in immunized rabbits. 18 5

Acetylcholinesterases in the muscle homogenates of hamsters receiving ACTH intraperitoneally for six weeks were reduced as compared to the activities in the control samples. In polyacrylamide disc gel electrophoresis of the ACTH-treated muscles some acetylcholinesterase bands were absent. These observations may be significant in explaining the ACTH-induced improvement in myasthenia gravis patients and in the pathophysiology of steroid myopathy.
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PMID:Effect of adrenocorticotrophic hormone on muscle acetylcholinesterase and nonspecific esterase. 19 33

We studied a 57-year old woman with severe myasthenic syndrome predominantly proximal. There was no therapeutic effect using cholinesterase inhibitors. Clinical findings, electromyography, whole body scanning and biopsy revealed polymyositis. Thirteen years before the patient was operated of a benign thymoma. The history of the patient showed numerous life threatening episodes of viral and fungal infections. Autoimmune anemia was diagnosed. Investigations of the immune system in vivo and in vitro revealed severe qualitative and quantitative defects in the lymphocyte population spontaneously forming rosettes with sheep red blood cells (SRBC). Thymoma, autoimmune disorder, such as polymyositis and myasthenia gravis, unspecifically elevated antibody titers, multiple severe viral and fungal infections and the defect of the cell-mediated immunity suggest a T-lymphocyte effector- and regulatory dysfunction in this patient.
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PMID:Polymyositis, myasthenic syndrome and thymoma in a patient with defective cell-mediated immunity. 31 78

Myasthenia gravis developed in two children at 2 and 3 years of age respectively. Minimal improvement followed chronic oral administration of cholinesterase inhibitors. Patient 1 had ptosis and ophthalmoplegia but no clinical or electromyographic involvement of muscles of the extremities, although a quadriceps muscle biopsy revealed lymphorrhages. Patient 2 had progressive generalized myasthenia for 3 1/2 years. Both children were given a 3-month course of prednisone followed by thymectomy. They both are in remission, 12 and 8 months after thymectomy, with only minimal residual ocular weakness, but this weakness is much more responsive to anticholinesterase drugs than before thymectomy. Long-term administration of steroids, with the attendant complication of growth retardation, is avoided.
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PMID:Effective treatment of infantile myasthenia gravis by combined prednisone and thymectomy. 55 63

The acetylcholine receptors at the mammalian motor end plate have been counted and their distribution there determined ultrastructurally. Electron microscope autoradiography applied to muscles labeled with alpha-(3H)bungarotoxin was used for this purpose. The receptors are distributed asymmetrically along the postsynaptic membrane, being concentrated at the fold crests-that portion nearest to the presynaptic membrane. The density of receptor sites at that region is estimated to be 20,000-25,000 per mum2 of membrane surface. This density holds for the several species and muscle types thus far examined and appears to be a constant parameter of the motor end plate. It determines the limit of responsiveness to acetylcholine. By contrast, the enzyme acetylcholinesterase is found to be distributed evenly over the folds and may reside in the intersynaptic matrix. When mouse diaphragm end plates from dystrophic animals or animals following 5-day denervation were similarly examined, no significant alterations in either the density or the distribution of the receptor sites were found. Similarly, dystrophic muscles in chickens possess an unaltered number of receptors at their end plates. A model is outlined to correlate receptor and cholinesterase concentrations with known aspects of transmitter release. These findings may have relevance to some of the electrophysiological abnormalities seen in myasthenia gravis.
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PMID:Ultrastructural studies on the acetylcholine receptor at motor end plates of normal and pathologic muscles. 78 17

Plasmapheresis combined with prednisone and azathioprine therapy produced striking clinical improvement in five patients with myasthenia gravis who still had moderate to severe disability despite thymectomy, high-dose prednisone therapy and optimal doses of cholinesterase inhibitors. Serial determinations of titers of serum antibody toward the acetylcholine receptor demonstrated a fall to 21 +/- 5 per cent (mean +/- S.D.) of the original levels concurrently with the patients' increasing strength. Clinically improved patients maintained lowered titers, whereas clinical relapses were associated with a rebound in titer. Our results suggest that plasmapheresis will find a place in the management of patients with myasthenia gravis, and they implicate antibodies to acetylcholine receptor as a pathogenic factor in this disease.
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PMID:Plasmapheresis and immunosuppressive drug therapy in myasthenia gravis. 91 42

The morphology of motor end-plates in rabbits immunized with Torpedo nicotinic acetylcholine receptor (nAChR) has been studied by light and electron microscopy. Rabbits were studied either after one period of paralysis, some in parallel with electrophysiological recordings of MEPPs and EPPs and of Naja naja alpha-neurotoxin binding properties or after recovery followed by a second paralysis. Changes in the sub-neural apparatus were noted after cholinesterase staining only in the latter group. Ultrastructurally, however, most end-plates in both groups contained a wide range of abnormalities. Many were similar in appearance to those observed in human myasthenia gravis (MG). This further supports the theory that immunized rabbits can be used as a model for myasthenia gravis. In the rabbits with 1 period of paralysis an acute stage of influence on the neuromuscular junction seemed to be present while simplified motor end-plates typical for human MG were mostly found in rabbits with 2 periods of paralysis. Short post-synaptic folds in conjugation with thickeneed membrane-bound vesicles at their tops, inside the basement membrane, were frequently observed. These were interpreted as if the crests of the folds containing nAChR had degenerated and had been budded off. If so, a large number of receptor sites had been lost which would be one possible explanation for the lowered capacity of the muscles to bind Naja naja alpha-neurotoxin. Membrane thickenings with projections and striations were interpreted as reflecting ACh receptors and were observed in the post-junctional membrane without proximity to the nerve terminal. The degeneration of the top of the post-synaptic folds and the occurrence of receptors at other locations within the motor end-plate will result in a widened distance between the nerve terminal and the receptors, which can explain previous interpretations of a presynaptic defect in MG.
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PMID:Morphological observations on motor end-plates in rabbits with experimental myasthenia. 97 17


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