Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.8 (cholinesterase)
 12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Six to eight months after the Tokyo subway attack in March 1995, the neurophysiological effects of acute sarin poisoning were investigated in 18 passengers exposed to sarin (sarin cases) in the subways to ascertain the focal or functional brain deficits induced by sarin. The event-related and visual evoked potentials (P300 and VEP), brainstem auditory evoked potential, and electrocardiographic R-R interval variability (CVRR), together with the score on the posttraumatic stress disorder (PTSD) checklist, were measured in the sarin cases and the same number of control subjects matched for sex and age. None of the sarin cases had any obvious clinical abnormalities at the time of testing. The P300 and VEP (P100) latencies in the sarin cases were significantly prolonged compared with the matched controls. In the sarin cases, the CVRR was significantly related to serum cholinesterase (ChE) levels determined immediately after exposure; the PTSD score was not significantly associated with any neurophysiological data despite the high PTSD score in the sarin cases. These findings suggest that asymptomatic sequelae to sarin exposure, rather than PTSD, persist in the higher and visual nervous systems beyond the turnover period of ChE; sarin may have neurotoxic actions in addition to the inhibitory action on brain ChE.
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PMID:Asymptomatic sequelae to acute sarin poisoning in the central and autonomic nervous system 6 months after the Tokyo subway attack. 940 34

Donepezil is a cholinesterase inhibitor used for the treatment of patients with mild to moderately severe Alzheimer's disease (AD). The purpose of this study was to determine the effect of treatment with donepezil 5 mg qd on cognitive evoked potentials (EPs) of patients with AD. Although treatment with donepezil did not normalize EP latencies, treatment was associated with a significant decrease in the auditory P300 latency (mean latency pretreatment=401. 5 msec; posttreatment=392.7 msec.; P=0.04), and the visual P300 latency (mean latency pretreatment=605.7 msec; posttreatment=580.3 msec; P=0.04). Treatment with donepezil had no discernible effect on auditory or visual P300 EP amplitudes.
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PMID:The effects of donepezil on the P300 auditory and visual cognitive evoked potentials of patients with Alzheimer's disease. 1052 Nov 69

The latency of P300 "cognitive" event-related potentials changes if cholinergic activities of the central nervous system are pharmacologically manipulated. We tested the hypothesis that the new cholinesterase inhibitors donepezil (DPZ) and rivastigmine (Riv) may have an effect on the frequently abnormal P300 component in patients with Alzheimer disease (AD), thereby allowing a significant evaluation of cholinesterase inhibitors. We evaluated 60 patients with mild to moderately severe probable AD, in comparison with 60 age-matched control subjects, with P300 recordings and neuropsychologic examinations. Forty patients were randomly assigned in a double-blinded trial to 5-10 mg/d DPZ versus 2,000 IU/d vitamin E, and 20 patients were instead treated in an open trial with 1.5 to 12 mg/d Riv. In patients treated with vitamin E, we observed latency increments (7.4 +/- 3.5 msec) correlated with worsening neuropsychologic test scores. In patients treated with DPZ and Riv, we found significant P300 latency reductions (15.3 +/- 3.2 msec and 22.0 +/- 3.3 msec). Shorter P300 latencies were associated with higher Wechsler Adult Intelligence Scale scores and with lower AD Assessment Scale-cognitive subscale (ADAS-cog) scores (R = 0.72). Correlations between ADAS-cog changes and P300 changes significantly separated patients treated with DPZ and Riv from those treated with vitamin E. Administration of DPZ and Riv reduced the latencies of P300 components proportionately to neuropsychologic test improvements. Combined P300 and neuropsychologic test evaluation significantly separated DPZ-treated patients and Riv-treated patients from vitamin E-treated patients.
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PMID:Donepezil, rivastigmine, and vitamin E in Alzheimer disease: a combined P300 event-related potentials/neuropsychologic evaluation over 6 months. 1129 Aug 80

Earlier studies of cognitive event-related brain potentials (ERPs) reporting diminished amplitudes and delayed latencies of the P300 potential in dementia of the Alzheimer type (DAT), together with independent findings of the P300- and performance-enhancing properties of nicotine in normal adults, stimulated this study to explore the single-dose effects of nicotine on auditory and visual P300s in DAT. Thirteen patients, 6 currently receiving treatment with the cholinesterase inhibitor tacrine (tetrahydroaminoacridine; THA) and the remaining being medication free, were administered 2 mg of nicotine polacrilex under double-blind, randomized, placebo-controlled conditions. Prior to nicotine administration, THA-treated patients exhibited shorter auditory P300 latencies than non-treated patients. Acutely administered nicotine failed to alter auditory P300, but increased the amplitudes of visual P300s in both DAT patient groups. Neither THA treatment nor single-dose nicotine altered behavioural performance in the visual and auditory task paradigms. The results are discussed in relation to nicotinic cholinergic, attentional and cognitive processes in DAT.
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PMID:Effects of acute nicotine administration on cognitive event-related potentials in tacrine-treated and non-treated patients with Alzheimer's disease. 1197 67

Centrally acting cholinesterase inhibitors (ChEls) improve cognitive functions in Alzheimer's disease (AD) and other forms of dementia. Evaluation of treatment efficacy is based mainly on subjective assessment tools which includes standardized neuropsychological tests. Therefore, an additional objective tool for the evaluation of drug response is necessary. Thirty two patients were treated with ChEls for dementia (tacrine 19, donepezil 5, rivastigmine 8). Cognitive response was assessed before ChEls (baseline) and after 26 weeks, as optimal tolerated doses were achieved and maintained (endpoint). Evaluation included repeated measurements of Mini Mental State Examination (MMSE), ADAS-cog and P300. For statistical analysis we used ANOVA with repeated measures and Pearson correlation coefficient. Results demonstrated improvement of mean ADAS-cog by 2.0 points (from 29.4 to 27.4 p = 0.08) while MMSE remained almost unchanged (20.1 to 19.8). Mean P300 latency reduced significantly by 24 msec (from 383 msec to 359 msec, p = 0.0001) thus reflecting the clinical improvement. However mean amplitudes did not change from baseline to endpoint (13 microvolts). Significant correlation was found between mean ADAS-cog and mean P300 latency at baseline and end-point (R = 0.452 p = 0.014, R = 0.567 p = 0.001 respectively). Strong correlation was found between mean MMSE and P300 latency at Baseline (R = -0.335 p = 0.07), and significant correlation was found at endpoint (R = -0.613 p < 0.001). Our data suggests that P300 is a reliable instrument for assessment of cognitive response to ChEls in demented patients.
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PMID:Evaluation of cholinergic treatment in demented patients by P300 evoked related potentials. 1200 52

Centrally acting cholinesterase inhibitors (ChEIs) improve cognitive functions in Alzheimer's disease (AD) and other forms of dementia. Evaluation of treatment efficacy is based mainly on subjective assessment methods such as standardized neuropsychological tests. Therefore, an additional objective tool for the evaluation of drug response would be most helpful.Thirty-two patients suffering from dementia of several etiologies were treated with ChEIs (tacrine 19, donepezil 5, rivastigmine 8). Cognitive response was assessed pre ChEIs initiation (baseline) and after 26 weeks, as optimal tolerated doses were achieved and maintained (endpoint). Evaluation included repeated measurements of Mini Mental State Examination (MMSE), Alzheimer's disease assessment scale cognitive part (ADAS-cog) and P300. For statistical analysis we used ANOVA with repeated measures and Pearson correlation coefficient. Results demonstrated improvement of mean ADAS-cog by 2.0 points (from 29.4, n = 31 to 27.4, n = 29; p = 0.08) while MMSE remained almost unchanged (20.1, n = 29 to 19.8, n = 28). Mean P300 latency reduced significantly by 24 ms (from 383 +/- 7.9 msec, n = 32 to 359 +/- 7 msec, n = 32; p = 0.0001). However mean amplitudes did not change significantly from baseline to endpoint (13.5 +/- 6.2, n = 31 to 12.8 +/- 6.1, n = 31). Significant correlations were found between mean ADAS-cog and mean P300 latency at baseline and end-point (R = 0.485 p = 0.019, R = 0.626 p = 0.001 respectively, n = 23) and between mean MMSE and P300 latency at baseline and endpoint (R = -0.420 p = 0.046, R = -0.703 p < 0.001 respectively, n = 23). Our data suggests that P300 is a reliable instrument for assessment of cognitive response to ChEIs in demented patients.
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PMID:The clinical use of P300 event related potentials for the evaluation of cholinesterase inhibitors treatment in demented patients. 1276 61

This article has reviewed several abnormalities in the cognitive ERPs of AD patients. These abnormalities are prominent from latencies of approximately 200 msec and later. In contrast, sensory-dependent evoked potentials, such as N100, are generally normal in AD. This finding is as one familiar with the neuropathology of AD would predict. Predilection sites in early AD include the medial temporal lobe, other limbic areas, and multimodal association cortices with sparing of primary sensory areas. Unimodal association cortex is involved in AD, but not as heavily as multimodal cortex. Particular advantages of studying a given ERP paradigm or component depend largely on the specific application or hypothesis being tested. A P300 paradigm can be useful in detecting a disorder of attention or in quantifying the effects of drugs that improve attention, such as the cholinesterase inhibitors. For the early diagnosis of AD or other memory disorders, a word-repetition paradigm with an explicit recognition task or one that fosters associative learning would be recommended. This article has discussed potential use of N400 in tracking disease progression. ERPs provide a flexible and powerful technique, with superb temporal resolution, which can be used as a probe into subtle "subclinical" abnormalities of cognitive processes. Despite being applied to AD for about 25 years since the early P300 studies, the full potential of ERPs in helping diagnose and treat AD patients has yet to be realized. In this era of rapidly evolving brain-imaging techniques, electrophysiologic data are important in advancing understanding of cognition. Brain-mapping techniques that can inform where and when key cognitive processes occur are finally emerging. A final example of potential clinical application of cognitive ERPs is in the development of rational combinational treatment of cognitive enhancing drugs. Along these lines, P300 investigations in epilepsy proved helpful in ranking the cognitive side effects of anticonvulsant drugs. Drug studies that use 2 x 2 combinational designs, which compare the effects of drug A, drug B, with A + B, are currently prohibitively expensive for full-scale clinical trials in AD. It is likely that precise ERP measures could hasten drug development in several ways. Smaller samples could be used, at lower cost, to test the cognitive effects of each specific drug combination. Optimal doses of combinational therapy perhaps could be identified by repeated within-subject ERP measures. Longitudinal changes in the ERP hold promise as a marker of individual responsivity to a particular agent, which could have diagnostic utility (eg, testing response to cholinergic or dopaminergic therapy). This horizon and many others remain wide open for well-planned explorations.
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PMID:Clinical applications of cognitive event-related potentials in Alzheimer's disease. 1502 6

Event-related potential (ERP) is a reliable neuroelectric measure of brain activity that helps to confirm the assessment of mental status and cognitive impairment. Many studies have reported that alcoholics show a significantly lower ERP P300 amplitude than the norm. In the present study, ERP P300 waves were measured to evaluate the effect of citric acid on cognitive function during excessive alcohol consumption in healthy adults. Five volunteers were selected through clinical interview, physical examination, and psychiatric assessment for participation in this study. In a double-blind placebo-controlled before-after design, each subject was treated with 5 ml/kg body weight alcohol, 5 ml/kg body weight alcohol and 1 mg citric acid, or a placebo on three separate occasions, one week apart. ERP P300, blood biochemical indicators, blood alcohol concentrations (BACs) and acetaldehyde concentrations were assessed. Repeated measure analysis of variance (ANOVA) with a within-subjects factor was used to evaluate differences in blood biochemical indicators, BACs, blood acetaldehyde concentrations, and ERP P300 in the three sessions of assessments. Several blood biochemical indicators showed significant differences between treatments, including the levels of cholinesterase (CHE), total bile acid (TBA), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), and glycylproline dipeptidyl aminopeptidase (GPDA). BACs after consumption of alcohol alone or citric acid with alcohol were significantly higher compared to those after placebo treatment (P<0.05). There were no significant differences in blood acetaldehyde concentrations between the treatments. The P300 amplitudes on the frontal (Fz), central (Cz), and parietal (Pz) regions of the scalp after consumption of alcohol were significantly lower than those after consumption of the placebo or citric acid with alcohol (P<0.05), while there were no significant differences between the latter two treatments. The results of this study suggest that citric acid could reduce the decline in ERP P300 amplitude and cognitive ability induced by acute alcohol consumption. It may also affect some blood biochemical indicators, but the specific mechanisms need further research.
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PMID:Citric acid reduces the decline in P300 amplitude induced by acute alcohol consumption in healthy adults. 2255 78