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)

The osmotic effect of intravenous glucose was investigated in eight healthy volunteers. Increases in plasma glucose can induce water movement from the intracellular to the extracellular space. Serum choline esterase was used as an endogenous marker of serum dilution. Intravenous tests with 5, 15, 30 and 35 g of glucose showed that the water shift was proportional to the amount infused. The respective dilutions of choline esterase were 1.3 +/- 0.7%, 3.3 +/- 0.9%, 6.3 +/- 0.8% and 7.8 +/- 0.5%. The effect on extracellular water was maintained when plasma glucose remained elevated (inhibition of insulin secretion with a somatostatin analogue). In comparison to glucose, infusion of 10 g of a mixture of amino acids produced a less pronounced effect than expected. The acute water shift after intravenous glucose dilutes serum components including glucose (8% of total extracellular glucose at 35 g). This can be misinterpreted as glucose clearance when calculating metabolic rates. For estimated amounts a proportional correction should be made (3.5% per 5 mmol l-1 increase). A measured plasma glucose of 22.2 mmol l-1 should be corrected to 24.8 mmol l-1, while a plasma glucose value of 5.0 mmol l-1 needs no correction.
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PMID:Glucose-induced water movement from the intracellular to the extracellular space and its influence on calculations of glucose metabolism. 835 32

Unilateral nucleus basalis magnocellularis (NBM) ablation, which causes partial cholinergic denervation of the ipsilateral anterior neocortex, results in an acute but transient depression of regional cerebral metabolic rates for glucose (rCMRglc) in deafferented areas; rCMRglc normalizes within 2 weeks. To seek possible compensatory changes in cholinergic mechanisms following NBM ablation that could lead to rapid metabolic normalization, we studied rCMRglc responses to the receptor agonists nicotine and arecoline and the cholinesterase inhibitor physostigmine in rats at 2 weeks after unilateral NBM destruction. Physostigmine increased rCMRglc in 10 of 30 cortical areas contralateral to the NBM lesion. Compared to the unlesioned side, rCMRglc after physostigmine in the lesioned cortex was significantly lower in 2, significantly higher in 1 and not different (P < 0.05) in 27 areas. Neither arecoline nor nicotine treatment produced rCMRglc asymmetry in lesioned rats. These results demonstrate that responsivity to physostigmine is maintained in most regions of the rat neocortex after extrinsic cholinergic denervation by NBM ablation. This adaptive response appears not to result from cholinergic receptor upregulation and may reflect instead reorganization of cholinergic synapses.
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PMID:Sustained cortical metabolic responsivity to physostigmine after nucleus basalis magnocellularis ablation in rats. 836 28

Cholinesterase activity is detectable in the Japanese quail embryo, in the yolk and subembryonic liquid, but not in the albumen. Obviously, this enzyme is deposited by the hen into the yolk and from there it is transferred to the subembryonic liquid. In contrast, in the embryo the enzyme is synthesized by itself and the amount increases with the age of the embryo. By using BW284c51 1,5-bis-(4-allyldimethylammoniumphenyl)pentan-3-one bromide and ISO-OMPA tetraisoprophylpyrophosphoramide as inhibitors, it was found that the enzyme in the embryo is predominantly acetylcholinesterase (EC 3.1.1.7), whereas that in the yolk and subembryonic liquid is butyrylcholinesterase (EC 3.1.1.8). Both types are inhibited by dichlorphos. However, the embryonic enzyme activity is restored within 8 hr, whereas that in the subembryonic liquid remained inactive at least for 72 hr after inhibition. Enzyme inhibition leads to retardation of the development, to reduced accumulation of glucose and amino acids in the subembryonic liquid and finally to death of the embryo, suggesting that the developmental retardation is due to the restricted supply of glucose and amino acids. Surprisingly, most of the embryos die when the embryonic enzyme activity has again been restored.
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PMID:Activity of cholinesterases in the Japanese quail embryo. Effects of dichlorphos on the embryonic development. 842 27

The aim of this study was to investigate the regulation of various proteins of the GHIGF axis during progression of liver failure and to search for potential prognostic markers of functional hepatic reserve. Serum levels of growth hormone (GH) and high affinity growth hormone binding protein (GHBP), insulin-like growth factor I (IGF-I) and IGF binding proteins (IGFBP) -1, -2 and -3 were determined in patients with liver cirrhosis. A continuous decline in the concentrations of IGF-I, IGFBP-3 and serum GH-binding activity (GHBP) was observed during progression of cirrhosis and the data correlated significantly with choline esterase, total serum protein and the Child score. In addition, GHBP showed a significant correlation with the enzymatic activity of glutamate dehydrogenase or transaminases and seems so to be influenced by the degree of liver cell damage. In contrast, IGFBP-1 and IGFBP-2 levels were significantly elevated in preterminal disease suggesting an upregulatory mechanism is still effective in this situation. Only when liver function had markedly deteriorated, the serum levels of these two parameters decreased again, possibly due to an impaired synthesis. The excellent correlation between the serum levels of IGF-I (r = -0.64, p < 0.001) or IGFBP-3 (r = -0.67, p < 0.001) and the Child score index suggests that they reflect the hepatic functions just as conventional indicators. For an appropriate interpretation of the liver function the measurement of the growth related peptides can be a valuable tool to estimate pathological alteration in the functional hepatic reserve or in the glucose homeostasis.
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PMID:Regulation of growth hormone (GH), insulin-like growth factor (IGF)I, IGF binding proteins -1, -2, -3 and GH binding protein during progression of liver cirrhosis. 853 56

Various types of potentiometric and amperometric biosensors are characterized: microbial sensors with Gluconobacter oxydans cells with potentiometric (pH-sensitive field-effect transistor) and amperometric (Clark-type) electrodes for determining glucose; a potentiometric enzymatic electrode with butyrylcholinesterase, which is used in the biosensor designed to detect pesticides; immunosensors with pH-sensitive field-effect transistors which detect the herbicide 2, 4-D; a biosensor for human immunoglobulin G; biosensors with anaerobic bacteria Clostridium thermocellum; chemical and enzymatic sensors containing a photosensitive membrane for determining ammonium ions and urea; and amperometric microbial sensors prepared with Pseudomonas cells for determining naphthalene, biphenyl, and polychlorinated benzoates. Practical applications of the developed models of biosensors to medicine, biotechnology, and environmental monitoring are discussed.
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PMID:[Biosensor models based on potentiometric and amperometric transducers for use in medicine, biotechnology, and environmental monitoring (review)]. 863 42

We have analyzed diagnostic efficiencies of the individual "Essential laboratory test" items when these tests were applied to 520 new outpatients in the division of comprehensive medicine in a teaching hospital. The integration of these test results with history-taking and physical examination resulted in 544 primary clinical diagnoses which corresponded to the patient's illness complained and in 361 additional diagnoses unrelated to their chief complaints but found by chance by the addition of the test results. Clinical usefulness of these test items were variable depending on the disease category, demonstrating a superior diagnostic efficiency in infectious or inflammatory diseases, liver and biliary tract diseases, hematological disorders or metabolic diseases such as hyperlipidemia and diabetes mellitus, but a lesser degree of usefulness in gastro-intestinal or neurogenic diseases. Urine urobilinogen could not establish its clinical usefulness because of extremely low diagnostic sensitivity even in liver diseases. The leukocyte differential count provided confirmatory information for infectious or inflammatory diseases and was helpful for the estimation of the etiologic nature of infectious diseases. This study failed to terminate a controversy for the adoption of sialic acid instead of erythrocyte sedimentation rate (ESR) in the "Essential laboratory test" items, since the former test showed lower sensitivity, even though higher specificity, in infectious or inflammatory status than ESR. Low albumin globulin ratio (A/G) revealed equivalent diagnostic sensitivity and specificity to the elevated levels in alpha 1 and/or alpha 2 globulin fractions in infectious or inflammatory status, being helpful for the evaluation of patient's general condition at a glance. Incidental analysis for diagnostic values of cholinesterase and random blood glucose for the detection of fatty liver and diabetes mellitus, respectively, suggested that these two tests may be included in the "Essential laboratory tests". Simultaneous measurement of serum creatinine and blood urea nitrogen levels was recommended for the ambulatory screening of renal insufficiency, rather than the measurement either alone. The results in this study provide scientific bases on the usefulness of the individual test items and should be taken into account in the next version of the "Essential laboratory tests".
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PMID:The results of the "essential laboratory tests" applied to new outpatients--re-evaluation of diagnostic efficiencies of the test items. 875 34

The effects of the centrally acting anti-cholinesterase metrifonate (MFT) and its metabolite dichlorvos (2,2-dichlorovinyl dimethyl phosphate; DDVP) on local cerebral glucose utilization (LCGU) have been studied in 3- and 27-month-old rats, using the autoradiographic [14C]deoxyglucose technique. In 3-month-old rats, MFT (80 mg/kg i.p.) increased LCGU significantly in 17 of the 54 regions studied, including insular, cingulate, and temporal cortices, ventral hippocampus, thalamus, lateral habenula, substantia nigra, and superior colliculus. In these regions, the average MFT-induced increase in LCGU was 23% above control. The average hemispheric LCGU increased by 10% (p < 0.01). DDVP (5 mg/kg) increased LCGU in 19 regions (average increase 26%). The average hemispheric LCGU increased by 9% (p < 0.01). Regional distributions of MFT- and DDVP-induced increases in LCGU were similar and overlapped the distribution of the acetylcholinesterase activity. In 27-month-old rats, MFT was active in 18 regions (average increase 25%). The whole-brain mean LCGU increased by 10% (p < 0.01). MFT compensated for the age-related hypometabolism in some brain areas including insular, temporal, and retrosplenial cortices, substantia nigra, and superior colliculus. The effects of MFT on LCGU were preserved in old rats, at variance with other anticholinesterases (tacrine, physostigmine). Which are less active in the aged rat brain.
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PMID:Effects of metrifonate, a cholinesterase inhibitor, on local cerebral glucose utilization in young and aged rats. 878 47

Functional imaging techniques offer new possibilities for further understanding of changes in functional correlates of structural and biological changes in dementia disorders like Alzheimer's disease (AD). Regional disturbances in glucose metabolism and cerebral blood flow are known to occur in AD brains and probably roughly correlate to changes in neurotransmitter activities. A proper estimate would be to visualize the neuroreceptors themselves. In this study the cholinergic nicotinic and muscarinic receptors were studied in brain by positron emission tomography (PET). The rate constant k2* (s) (-)11C-nicotine was significantly higher (+43%) in temporal cortex of AD patients compared to controls (p < 0.017) indicating a lower binding of 11C-nicotine in AD brains compared to controls. Treatment with the cholinesterase inhibitor tacrine (80 mg daily) during 3 months to AD patients resulted in a mean plasma concentration of 7.7 +/- 0.8 ng/ml and a corresponding inhibition of the cholinesterase activity in plasma by 34 +/- 5%. A significantly lower k2* (increased binding) for 11C-nicotine binding (-15%; p < 0.006) was obtained in the temporal cortex after 3 months of treatment compared to prior treatment. The muscarinic antagonist 11C-benztropine was used to visualize muscarinic receptors and the binding capacity of 11C-benztropine (KR) was found to be decreased in the temporal cortex after 3 months of tacrine treatment.
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PMID:Imaging of nicotinic and muscarinic receptors in Alzheimer's disease: effect of tacrine treatment. 906 19

The effects of scopolamine, a muscarinic cholinergic receptor antagonist and physostigmine, a cholinesterase inhibitor, on the regional cerebral blood flow (rCBF) response to vibrotactile stimulation of the forepaw were studied in the brain of unanesthetized monkeys using 15O-labeled water and high resolution positron emission tomography. Before scopolamine administration, vibrotactile stimulation produced a significant increase in the rCBF response in the contralateral somatosensory cortex of the monkey brain. Intravenous administration of scopolamine at doses ranging from 1 to 500 microg/kg resulted in a dose-dependent reduction of the rCBF response. The rCBF response abolished by scopolamine (50 microg/kg) was recovered by administration of physostigmine (10 microg/kg). On the other hand, the regional cerebral metabolic rate of glucose (rCMRglc) response, measured with [18F]-2-fluoro-2-deoxy-D-glucose, to the same stimulation was unchanged by administration of either scopolamine and/or physostigmine. These results suggested that cholinergic mechanisms might be involved in regulation of the coupling between neuronal activity and rCBF response, not between the activity and rCMRglc response.
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PMID:Regulation of cerebral blood flow response to somatosensory stimulation through the cholinergic system: a positron emission tomography study in unanesthetized monkeys. 907 Jun 22

The Japan Society of Clinical Pathology has proposed guidelines for efficacious utilization of laboratory tests in primary care medicine. In a series of our studies, attempts were made to assess the usefulness of the "Essential laboratory tests" which are common laboratory tests to be applied for new outpatients regardless of the clinics and disease categories. We looked the individual test item again in the aspect of diagnostic efficiency for the next version of the guideline. An analysis of 1026 new outpatients in Comprehensive Medicine, National Defense Medical College, demonstrated the usefulness of the "Essential laboratory tests" not only for the establishment of more accurate initial diagnosis but also for the screening of the occult diseases unrelated to the patient's chief complaints. Another clinical study with 520 new outpatients established diagnostic efficiency of the individual test item by calculating diagnostic sensitivity, specificity and positive predictive value. There were test items such as urine urobilinogen to be taken away from the guideline because of its extremely low sensitivity, and such as random blood glucose and serum cholinesterase to be added for the screening of urine-glucose negative diabetes mellitus and possible fatty liver, respectively. There have been some controversies in the selection of inflammation markers such as erythrocyte sedimentation rate or serum sialic acid; the former revealed higher diagnostic sensitivity but had lower specificity in infectious or inflammatory diseases than the latter.
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PMID:[Assessment of the guidelines for efficacious utilization of laboratory tests in primary care medicine]. 913 98


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