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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

After discussion of the modern concepts of pathophysiology of ocular myasthenia the ocular symptoms such as ptosis and eye muscle palsies are discussed. As important diagnostic sign the Simpson lid fatigue test before and after application of Tensilon is described. For diagnosis of myasthenic eye muscle palsies electrooculography has a special significance especially in connection with the application of Edrophonium, which normalizes myasthenic hypometric saccades and transforms them even in hypermetric saccades. In doubtful cases of eye muscle palsies the electromyogram of the affected muscle in connection with the Edrophonium-test is extremely valuable. With regard to modern treatment apart from cholinesterase inhibitors (Pyridostigmine, Neostigmine) thymectomy, the application of corticosteroids, ACTH and especially also immune suppressive drugs (Imurel etc.) is discussed. Of great significance in ocular myasthenia is the local application of cholinesterase inhibitors like Eserine, Prostigmin or Phospholine Iodide.
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PMID:[Diagnosis and treatment of ocular myasthenia (author's transl)]. 20 42

In 4 patients with clinical signs of dermatomyositis, confirmed by electromyography and muscle biopsy, a form of muscle fatigue was detected which was expressed clinically by predominantly proximal motor deficit, with phonation and deglutition disturbances, slightly influenced by prostigmine. In all patients, stimulation of the ulnar nerve at 3--10 Hz induced a decrement of muscle-evoked potentials in abductor digiti minimi and at 15--50 Hz an increment at the end of the trains (1.2 sec in duration) of repetitive stimulation (preceded in two cases by a decrement in the response to the fifth stimulus in the train). Stimulation at 30 Hz for 10 sec resulted in a transient facilitation, followed (at 3 Hz stimulation) by postactivation exhaustion which disappeared after 5--15 min. The post-tetanic facilitation, the incremental response and the myasthenic symptoms reverted to normal under treatment with corticosteroids, an immunosuppressor agent and guanidine hydrochloride. A mixed, pre- and postsynaptic mechanism is presumed to underlie the muscle fatigue in our patients. Electron microscopy of muscle biopsies disclosed zones of necrosis and, in incipient stages, large agglomerations of glycogen that had disorganized the structure of myofibrils. The end-plates in the biopsies were larger than normal and the cholinesterase reaction was hyperactive. Serum immunoelectrophoretic and electrophoretic data--increase of IgG and IgM, decrease of IgA and hypergammaglobulinaemia -- point to a possible autoimmune mechanism of the neuromuscular disorders in our patients.
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PMID:Myasthenia in patients with dermatomyositis: clinical, electrophysiological and ultrastructural studies. 21 37

The effect of carbohydrates, aromatic alcohols, choline and acetylcholine on the biomass production and biosynthesis of choline esterase was studied with Arthrobacter simplex var. cholinesterasus. Fructose was found to be the best carbon source for the biomass accumulation and synthesis of choline esterase. Almost the same amount of the enzyme was produced on media with glucose and maltose as on the medium with fructose though the biomass yield was much lower. On the contrary, the biomass production was higher on media with acetylcholine and ethanol, but synthesis of the enzyme was inhibited. Choline was not assimilated by the culture. Differences in assimilation of glucose and fructose by the culture were found to depend on their concentration and the presence, or absence, of the inductor (acetylcholine) in the medium. Fructose was assimilated by the culture almost completely irrespective of its concentration and the presence of the inductor in the medium. Glucose was assimilated partly, best of all at a concentration of 0.5%. An increase of the concentration to 1% inhibited assimilation of glucose by the organism though had no effect on the biomass production and synthesis of the enzyme. The inductor stimulated assimilation of glucose by a factor of 1.5. Synthesis of choline esterase on the medium with acetylcholine at a concentration of 1% was increased more than twofold upon addition of glucose at a concentration of 0.1%. Biosynthesis of the enzyme rised with glucose concentration though accumulation of the biomass was inhibited. Inhibition of choline esterase synthesis on the medium with acetylcholine as a sole carbon source is due to a lack of energy and the absence of synthesis of carbon compounds which are acceptors of acetyl and methyl groups.
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PMID:[Effect of various carbon sources on cholinesterase formation by Arthrobacter simplex var. cholinesterasus]. 100 62

Major findings from our work on exposures and effects from organophosphate-containing pesticides in selected occupational and community patients and groups in Israel are reviewed as a basis for recommending control measures. The worker groups were pilots, ground-crews, and field workers; exposed nonworkers were adults and children living in kibbutzim with drift exposures, and household residents in houses treated by pest exterminators. In all groups, evidence of exposure-illness associations was found even though persons with acute poisoning were not seen. Complaints (headache, dizziness, fatigue, nausea, breathing problems, abdominal cramps, and tingling in extremities) were associated with within-normal depressions in cholinesterase activity. Whole blood and plasma cholinesterase activity were slightly more sensitive indicators of mixed exposure than red blood cell cholinesterase activity. High alkyl phosphate levels and symptoms were seen in individuals with within-normal limit depressions in cholinesterase activity. Complaints of weakness and tingling in hands and feet, together with low-grade changes in nerve conduction, suggest the possible influence of agents with a neurotoxic esterase-type activity independent of cholinesterase activity. Transient in-season neuropsychological changes in tests of mood status and performance were associated with exposure. Recommendations for exposure reduction include: accelerating the already declining use of pesticides in general, and organophosphates in particular; promoting the shift from more to less toxic organophosphates and other pesticides; and introducing rigid performance specifications for closed systems in loading and mixing at end-user sites. Dermal protection remains a problem. Cholinesterase activity levels and symptom interviews are useful for monitoring workers at risk, but alkyl phosphate levels are the definitive measure of exposure, surveys, investigations and surveillance.
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PMID:Health effects from exposure to organophosphate pesticides in workers and residents in Israel. 133 Sep 77

A case report of an urban family who experienced excessive exposure to organophosphate and carbamate pesticides is presented. All three family members developed symptoms that were compatible with cholinesterase inhibition: headache, lightheadedness, wheezing, shortness of breath, nausea, and fatigue. Serial measurement of red blood cell and serum cholinesterases soon after exposure and during subsequent months confirmed the diagnosis of pesticide poisoning. This report demonstrates that the misapplication of pesticides commonly used in residences in urban areas can cause acute pesticide poisoning and demonstrates the usefulness of repeated measurements of cholinesterase during the post-exposure period in establishing the correct diagnosis.
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PMID:Poisoning of an urban family due to misapplication of household organophosphate and carbamate pesticides. 158 78

Pyridostigmine bromide, a reversible inhibitor of acetylcholinesterase (AChE), is effectively used as a pre-treatment to organophosphate intoxication. Previous studies have shown that an oral dose of 30 mg twice a day produces a sufficient inhibition of the enzyme activity (20-40%) without causing any significant adverse effect. During the Persian Gulf war pyridostigmine was taken for the first time under a chemical warfare threat. We searched for symptoms and complaints that may be related to the medication. Our survey included 213 soldiers who completed a questionnaire regarding possible symptoms and their severity. AChE inhibition level was compared between groups of soldiers with and without complaints. The most frequent symptoms were nonspecific and included dry mouth, general malaise, fatigue and weakness. Typical effects, such as nausea, abdominal pain, frequent urination and rhinorrhea, were infrequent. The severity of the symptoms was generally mild. The symptoms appeared around 1.6 h after taking the medication and recurred after each intake. No correlation was found between levels of cholinesterase and type or severity of complaints. Anxiety, which accompanies wartime, may have contributed to the appearance of significant symptoms. Further investigations concerning the effects of pyridostigmine ingestion under stressful conditions are warranted.
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PMID:Survey of symptoms following intake of pyridostigmine during the Persian Gulf war. 175 41

Aerial application of organophosphates can result in exposure to drift and leaf residues for pilots, ground crews, field workers, and residents near sprayed fields. Exposure can be by either the airborne or dermal route, and can produce illness (headaches, fatigue, diarrhea, cramps, respiratory problems) even with low-grade depressions in cholinesterase. Alkyl phosphate metabolites have been shown to be "gold standard" measures of such exposures. Experience in Israel indicates that reduction of health hazards from exposure to drift and leaf residues may be attained by the use of a comprehensive "mix" of preventive measures. These measures include, first and foremost, reduction in total amount of organophosphates used, followed by substitution of less for more toxic organophosphates, reduction in length of spray season, banning the use of flaggers, and greater reliance on tractor spraying. Cotton yield per hectare cultivated has increased despite a reduction in use of pesticides of all kinds and organophosphates in particular. Enclosure and air-conditioning (to prevent heat stress) of cockpits, protective clothing, training and licensing of pilots have been implemented. Education and communication of information, in keeping with the right-to know principle on hazards and how they should be controlled and monitored, is a part of a comprehensive strategy. Aerial or ground spraying should produce no drift in adjacent residential communities. The criterion for achieving this goal is the absence of urine alkyl phosphate metabolites above the threshold of detection.
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PMID:Hazards associated with aerial spraying of organophosphate insecticides in Israel. 184 56

The prevalence of selected illnesses and symptoms during 1977-85 was compared between 175 employees potentially exposed to the organophosphate insecticide chlorpyrifos and 335 matched controls with no history of exposure to organophosphates. Subjects were subdivided into three exposure intensity groups on the basis of job title and air monitoring data for dose response testing. This classification scheme was shown roughly to correlate with plasma cholinesterase inhibition in the workers. No statistically significant differences in illness or prevalence of symptoms were observed between the exposed and unexposed groups or among the three exposure subgroups. Potentially exposed employees did report symptoms of dizziness and of malaise and fatigue relatively more often than subjects from the comparison group; however, further analyses by exposure level, process area, or time did not support a relation with exposure. No cases of peripheral neuropathy were seen among the exposed workers. Although the sample size was small and the statistical power limited, the cumulative exposures likely to have been experienced by this workforce exceed those to be expected for individuals using the product as recommended. The absence of exposure related adverse effects, including neurological impairment, is reassuring.
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PMID:Morbidity among employees engaged in the manufacture or formulation of chlorpyrifos. 246 78

A 37-year-old man suffered from photosensitivity and urinary casts with serological findings of positive anti-DNA antibody, LE cells and false positive VD reaction in September of 1979. He developed general fatigue, dyspnea and diplopia with ptosis of bilateral eyelids in November of 1979, which were improved by the anti-cholinesterase drugs. In January of 1980, he had an attack of unconsciousness and his chest X-ray film showed several tumorous shadows in the anterior mediastinum and middle and lower lung fields. Treating him with chemotherapy of VEMP, the pulmonary shadows disappeared. However, he developed severe muscle weakness with an elevated CPK (430 mU/ml) and a myogenic EMG pattern along with an increased anti-acetylcholine receptor antibody (243 n Mol/l), dysphagia and eyelid-ptosis. He died in September of 1985 and his autopsy disclosed a malignant thymoma of mixed type in the anterior mediastinum and an atrophy and fibrosis with infiltration of inflammatory cells in the striated muscles.
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PMID:[An autopsy case of a patient with myasthenia gravis who showed various symptoms of collagen diseases and complicated with malignant thymoma]. 281 7

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


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