Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.1.8 (cholinesterase)
12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two cases of acquired autoimmune myasthenia gravis (MG) presenting transient amenorrhea were reported. Case 1, 28 years old, developed blepharoptosis and generalized fatigability at the age of 20 years. She had been treated only by anti-cholinesterase. Amenorrhea appeared at the age of 26 years. Then, physical examinations showed normal secondary sexual development and moderate myasthenic features. On laboratory examinations, SLE findings such as leucopenia (1,600/mm3), biologically false positivity in the serological tests for syphilis, negative Mantoux reaction, positive anti-nuclear and -DNA antibodies, were noted. Anti-AChR antibody was highly positive (max.: 353 nmol/l). Decreased E2 (13-15 pg/ml) and progesterone (0.21-0.29 ng/ml) values in serum, elevated LH (110-160 mIU/ml) and FSH (78-90 mIU/ml) and highly reactive LH-RH loading test were consistent with the hypergonadotropic hypogonadism. Thymus pathology of thymectomy which was done during amenorrhea, showed hyperplasia. Bilateral ovarian biopsy revealed a number of arrested primordial follicles, but neither inflammatory changes nor fibrosis. Immune complexes were not localized in the ovarian biopsy. The Kaufmann's therapy aggravated myasthenic symptoms. Menstruation recurred after 13 months of thymectomy. Amenorrhea continued for 18 months. Case 2, 37 years old, has had anti-epileptic regimens since the age of 4 years. She has been highly myasthenic for 15 years and treated by thymectomy, steroid hormone, plasmapheresis and some other therapies for 10 years. Amenorrhea occurred at the age of 34 years. Sexual development was normal. Myasthenia was very severe. On laboratory examinations, anti-AChR antibody was positive (max.: 941 nmol/l). Transient elevation of serum LH (37 mIU/l) and FSH (14 mIU/l) values was observed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Two cases of myasthenia gravis associated with transient amenorrhea]. 279 17

Three patients with chronic obstructive lung disease (COPD) and myasthenia gravis whose pulmonary symptoms were worsened by therapy with cholinesterase inhibitors were improved by inhaled ipratropium bromide. Two had increases in FEV1 (19 percent, 35 percent) and specific conductance (106 percent, 81 percent) and reductions in dyspnea. The third had no change in airflow with ipratropium, but improved due to decreased bronchial secretions which had limited the use of cholinesterase inhibitors. In contrast, beta agonist bronchodilators had no effect in any of these patients. This experience suggests that ipratropium may be the bronchodilator drug of choice in patients with obstructive lung disease aggravated by cholinesterase inhibitors.
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PMID:Ipratropium in patients with COPD receiving cholinesterase inhibitors. 296 27

Correlation studies on patients with myasthenia gravis are reported in which clinical assessment of fatigue and neurophysiological findings are compared to blood levels of pyridostigmine. Measurements using a high-pressure liquid chromatography method (HPLC), give reproducible results. The levels of pyridostigmine in the serum or plasma of healthy controls and of patients show no essential differences. Components of coffee, tea, chocolate and cigarettes can markedly disturb the chromatography by adding additional peaks, so that interpretation becomes difficult or impossible. Blood levels can be measured approximately one hour after oral intake of 60 mg pyridostigmine. Concentrations rise for two to four hours and then decline exponentially. The half-life of pyridostigmine was between 156 and 210 minutes. Despite identical oral dosages, the concentration differed intraindividually and interindividually among patients. While the blood level does not reach its maximum value for 1-1 1/2 to 3 hours, the maximum clinical and neurophysiological effect of pyridostigmine appears 30-60 minutes after ingestion. Variable distribution of cholinesterase inhibitors over the different compartments (blood, synaptic region) is assumed to cause this temporal lag. If the total amount of pyridostigmine is divided into 4-5 doses, the concentration profiles over the course of a day are relatively stable. There is no significant correlation between the variations in blood level throughout one day, and changes in myasthenic symptomatology. Effects of pyridostigmine can be measured at levels as low as 5 ng/ml; at levels above 40 ng/ml further improvement can be detected only rarely. Blood levels were lower if corticosteroids were administered simultaneously; azathioprine had no influence on blood levels. Blood levels assays allow better differentiation of cholinergic and myasthenic crises and the identification of disturbed absorption and interactions with other medications.
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PMID:[Serum levels of pyridostigmine in myasthenia gravis: methods and clinical significance]. 299 Oct 94

3,4-Diaminopyridine (3,4-DAP), a potent potentiator of action potential evoked release of acetylcholine from presynaptic terminals in the neuromuscular junction was given i.v. and p.o. to two patients with myasthenia gravis. Effects were monitored electrophysiologically by repetitive nerve stimulation and by standardized clinical testing. Administration of 8 mg and 9 mg 3,4-DAP i.v. produced a clear improvement in the neuromuscular transmission after approximately 20 min. When 3,4-DAP was given p.o. 24 mg was shown to be effective. At a dosage of 18-24 mg p.o. 3,4-DAP significantly potentiated the effect of the cholinesterase inhibitor pyridostigmine at an optimal dose. The maximal effect of 3,4-DAP p.o. was obtained after 2.5-3 h. No significant CNS side-effects were found which is in contrast to those reported for 4-aminopyridine. The results suggest that 3,4-DAP may be useful as an addition to the conventional treatment with cholinesterase inhibitors when immunosuppressive treatment is considered contraindicated or when it has not yet reached its full effect.
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PMID:Improvement in neuromuscular transmission in myasthenia gravis by 3,4-diaminopyridine. 299 90

In 18 patients with juvenile myasthenia gravis (MG) the mean age of disease-onset was 12.1 years. The mean observation time was 6.8 years. After classification with regard to the clinical severity of the disease (Ossermann, 1958) 4 patients (22%) could be assigned to type I, 10 patients (56%) to type II A, 2 patients (11%) to type II B, and 2 patients (11%) to type III. 14 patients (77%) could be assigned to type I and type II A, both of them rather benign types. All 4 male patients belonged to this group. The tensilon test, investigated in 15 patients, showed a positive result in 13 cases (87%). The repetitive stimulation was done in 13 patients and was positive only in 6 cases (46%). Investigations in MG-patients without limitation of age showed positive results in about 70%. Increased levels of acetylcholin-receptor-antibody were found in 10 of 11 patients (91%). In 8 patients with the diagnosis MG, type II A and III, a thymectomy was done, 16 patients received cholinesterase-blockers, 1 patient with type II A, and both patients in group III received additionally azathioprin. In 1 patient with type III plasmapheresis was done. 75% of all thymectic patients showed a remission or improvement. Related to all 18 patients we found in 16 cases (89%) a remission or correction of the symptoms. In summary the prognosis in the group of our patients with juvenile myasthenia gravis was good.
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PMID:[The prognosis of juvenile myasthenia gravis]. 318 66

This review deals mainly with the pharmacokinetics of the reversible quaternary cholinesterase inhibitors neostigmine, pyridostigmine and edrophonium, which are mainly used to antagonise non-depolarising neuromuscular blockade in general anaesthesia and in the symptomatic treatment of myasthenia gravis. Only in the last few years, since the introduction of highly sensitive and selective analytical procedures based on gas and liquid chromatography, have proper pharmacokinetic studies of these drugs become possible. Rapid cooling and addition of internal standard to samples before freezing are important precautions in view of the poor stability of the cholinesterase inhibitors in plasma and blood. Plasma clearances of the reversible quaternary cholinesterase inhibitors are in the range 0.5 to 1.0 L/h/kg and their apparent volumes of distribution range from 0.5 to 1.7 L/kg. Accordingly, the drugs have short plasma elimination half-lives, in the order of 30 to 90 minutes. One to two hours after oral administration of 60 mg pyridostigmine, peak plasma concentrations of 40 to 60 micrograms/L are observed, whereas the plasma concentrations of neostigmine after a 30 mg oral dose are only 1 to 5 micrograms/L. The oral bioavailability of these hydrophilic ionised compounds is low: that of pyridostigmine is approximately 10% and the value for neostigmine is even lower. In spite of the short elimination half-life of pyridostigmine, intraindividual variations in plasma concentration during a dose interval are small in myasthenic patients receiving oral maintenance therapy, probably as a result of slow absorption from the gastrointestinal tract. Severely impaired renal function has been shown to prolong the elimination of neostigmine and pyridostigmine, while methylcellulose has been reported to inhibit the absorption of the latter drug completely. Other pharmacokinetic drug interactions suggested so far do not seem to be of clinical significance. Although a positive correlation has been demonstrated between the plasma concentrations of these drugs and their pharmacological effects as measured by a decrement in muscle response to repetitive nerve stimulation in a single muscle, this relationship is less clear when a global evaluation of muscular function in myasthenia gravis is used. Pharmacokinetic studies of the tertiary reversible cholinesterase inhibitor physostigmine, an important tool in experimental cholinergic neuropharmacology, are still in their initial stages. This drug too is characterised by a short plasma elimination half-life of 20 to 30 minutes.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Clinical pharmacokinetics of cholinesterase inhibitors. 352 57

Administration of anti-cholinesterase before operation and high doses of prednisolone after the operation are commonly prescribed in cases of thymectomy for the treatment of myasthenia gravis. Our policy is to carry out an extended thymectomy combined with pre- and post-operative administration of prednisolone on alternate days. Our method was used in the treatment of 50 patients with generalized myasthenia gravis, from January 1979 to December 1984. The results were examined in conjunction with the necessity for preoperative administration of an anti-cholinesterase preparation and also with factors influencing the follow-up result and postoperative process. This method made it feasible to perform surgery under conditions of stabilization of clinical symptoms and satisfactory postoperative management. A postoperative period of unstable symptoms could thus be avoided. The palliation rate at one year after the operation was 96 per cent, while the remission rate at 5 years after the operation was 70 per cent. The preoperative supplement of anti-cholinesterase and preoperative per cent forced vital capacity were considered to be predictive factors concerning the necessity of artificial respiration.
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PMID:Favorable results of thymectomy combined with prednisolone alternate-day administration in myasthenia gravis. 357 41

Pyridostigmine bromide, a quaternary carbamate, is widely used in treatment of myasthenia gravis and has been suggested for use in prophylaxis against intoxication with irreversible cholinesterase inhibitors. Since there are virtually no anatomical data concerning the neuromuscular toxicity of the drug, this study was undertaken to evaluate the effects of acute and subacute doses of pyridostigmine on the ultrastrucutre of nerve terminals in rat diaphragm neuromuscular junctions (NMJs). Pyridostigmine in a Mestinon-equivalent buffer was administered by single, subcutaneous injection (acute exposure; 10-30 min) or by a subcutaneously implanted Alzet osmotic minipump (subacute exposure; 2, 7 or 14 days). Acute exposure doses ranged from 0.0036 mg/kg to 3.6 mg/kg (0.001-1.0 LD50), while subacute exposure doses ranged from 0.43 to 20 mg of the drug. Both acute and subacute exposures resulted in dose dependent alterations of presynaptic elements in diaphragmatic NMJs, which included disruption of organelles in the axon terminal, regional or total withdrawal of the nerve terminal from postsynaptic junctional folds, and invasion of Schwann cell fingers into the synaptic cleft. These ultrastructural observations suggest that the normal cell-to-cell interactions at diaphramatic NMJs are altered by this "reversible," cholinesterase inhibiting drug.
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PMID:Ultrastructural effects of pyridostigmine on neuromuscular junctions in rat diaphragm. 371 19

Fourteen patients (twelve of them were women) with severe myasthenia gravis who had not responded to any treatment at all, were treated by cytostatic drugs. Both azathioprine and cyclophosphamide single or in combination are used. All patients except two were thymectomized and almost all were treated by plasmapheresis and corticosteroid before and during the cytostatic treatment. All patients take cholinesterase inhibitors. No serious complications were observed. The patients received 100-200mg of azathioprine and/or 100-200mg of cyclophosphamide daily by oral route, the first during 20 months and the second one during 6 months. Three patients received cyclophosphamide 1g daily by venous route during 6 months at 15-20 days intervals. The preliminary results were favourable occurring important improvement in 71.4% of the cases. Their performance increased considerably. The progress of the disease was generally stabilized. Exacerbations and crises did not recur, except in one case. Only three patients had not responded to the treatment, one responded poorly but better later and one had an exacerbation after the 24th month. This patient returned to azathioprine.
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PMID:[Treatment of myasthenia gravis by immunosuppressive non-steroidal drugs]. 380 Jun 86

Ocular myasthenia is a special form of general myasthenia gravis characterized by unilateral or bilateral ptosis and eye muscle pareses of distinct variability, depending on the time of day and the state of fatigue of the patient. Most important for diagnosis is the Tensilon test, which can, however, produce negative results. In such cases a combination of the Tensilon test with electromyography is indispensable. In ocular myasthenia there is not always an increase in the antibody titer against acetylcholine receptors in the blood. The treatment of ocular myasthenia is based on the application of cholinesterase inhibitors. The drug of choice is Mestinon; however, the reaction of the eye muscles to this drug is often unsatisfactory. Local application of cholinesterase inhibitors in the form of Eserine, Prostigmin etc. is an additional important therapy. Also in ocular myasthenia the modern treatment with Cortisone (alternate-day therapy with 100 mg Prednisone every second day) has proved very useful. Another possible method of interfering with the immunological systems of myasthenia is immunosuppression with Azathioprin or Cyclophosphamide. The pathognomonic significance of the thymus in the autoimmune process of myasthenia gravis is demonstrated by the good results obtained by thymectomy, which can also be performed successfully in ocular myasthenia, not only in young patients in whom the condition is severe, but also in older patients in whom it is chronic. Often, the therapeutic measures mentioned have to be tested one after another or in combination in order to achieve an optimal therapeutic effect.
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PMID:[Ocular myasthenia]. 399 98


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