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)

Conley et al., in 1971, described a special type of melanoma characterized by a superficial melanic lesion at the onset; repeated local relapses as subcutaneous tumorations with an histological picture closely resembling an atypical fibroxantoma or fibrosarcoma. After a review of all the published material the autors presents a personal case with the clinical, histological and evolutive characteristics of this disease. The most interesting findings of the published case are the following: The special stains for the melanocytes (silver stain, Dopa, tyrosinase and cholinesterase) were all negative. There was an intense positivity for the lisosomal enzymes (non specific sterases, and acid phosphatases). The ultrastructural study of the tumoral tissues as well as the cells of cultures showed abundant cells with tumoral aspects, with prominent nucleoli somewhat dilated granular endoplasmic reticulum, myelin-like figures, lipidic vacuoles and abundant lisosomes. No melanosomes or premelanosomes were observed. Beside these tumoral cells abundant typical fibroblastic elements were found. There was a great amount of collagen fibers with periodicity superior to the normal. The conclusion is that the desmoplastic melanoma must be considered as a tumor of mesenchimatous origin intervening in its development multiple local and general factors.
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PMID:[Desmoplastic melanoma]. 34 19

The dermal cells in grey, xanthic, and white goldfish integuments were cytochemically characterized for the following enzymatic activities: tyrosinase, DOPA-oxidase, cytochrome oxidase, monoamine oxidase, peroxidase, non-specific esterase, cholinesterase, NAD-diaphorase, NADP-diaphorase, aryl sulfatase, nucleotide phosphodiesterase, beta-glucuronidase, acid phosphatase, alkaline phosphatase, adenosine triphosphatase, thiamine pyrophosphatase, glucose-6-phosphatase, aldolase, as well as succinate, malate, isocitrate, glutamate, glucose-6-phosphate, 6-phosphogluconate, alpha-glycerophosphate, alcohol, lactate, and beta-hydroxybutyrate dehydrogenases. It was found that the epidermis was a significant barrier to the access of cytochemical reaction substrates. Removal of the epidermal barrier provided dermal cell localizations of enzymatic activities which were reproducible. Further, alterations in reaction times and temperatures from the mammalian methodology provided conditions fe various integumental cells were compared for possible interrelationships. The basic foundations for future work with the dermis of poikilothermic vertebrates on an experimental basis were established. In addition, a previously undescribed non-pigmented dermal cell, the "x"-cell, was found to have enzymatic characteristics similar to both melanophores and lipophores. The "x"-cell may be the common precursor of both types of pigment cells.
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PMID:Cytochemical characterization of goldfish (Carassius auratus L.) dermis with special reference to the pigment cells. 82 86

In order to clarify the histogenesis of clear cell sarcoma of tendons and aponeuroses (CCS), two cases of human and one nude mouse-transplanted CCS line were studied using an ultrastructural and enzyme cytochemical approach. Most of the tumour cells obtained from the primary and transplanted CCS demonstrated melanosomes in various stages of development within the cytoplasm, whereas no melanosomes could be identified in the metastatic CCS. However, cholinesterase and tyrosinase activities could be demonstrated not only in the melanotic primary and transplanted CCS but also in the amelanotic metastatic CCS. The results therefore support the hypothesis that CCS is a soft tissue tumour derived from the neural crest.
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PMID:Neural crest origin of clear cell sarcoma of tendons and aponeuroses. Ultrastructural and enzyme cytochemical study of human and nude mouse-transplanted tumours. 249 78

Molgula tectiformis is a new ascidian species recently described by Nishikawa (1991). In Otsuchi Bay, Iwate, Japan, they are easily obtainable from cages for culturing scallops. We report here that M. tectiformis is another example of a direct developer: their embryonic development is lacking the tadpole larva. The fertilized egg is orange and about 150 microns in diameter. At 18 degrees C, the egg cleaves at about 20 min intervals and gastrulation occurs about 5 hr after fertilization. In contrast to conventionally-developing ascidians, M. tectiformis does not form a tadpole larva. Immediately before hatching, three stolons or ampullae begin to extend from the tailless embryo. After hatching the stolons mediate the attachment of the juvenile body to the substratum. Histochemistry for tissue-specific enzyme activity did not detect muscle-specific acetyl-cholinesterase, endoderm-specific alkaline phosphatase, and pigment cell-specific tyrosinase. In addition, in situ hybridization could not prove the presence of muscle actin gene transcripts in the embryo. These results suggest that these larval tissues do not differentiate in M. tectiformis embryos. Because M. tectiformis is common and gravid year-around in Otsuchi Bay, this direct developer provides the opportunity for further analysis of molecular changes during evolution that cause an alternative mode of development.
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PMID:The recently-described ascidian species Molgula tectiformis is a direct developer. 925 52

Screen-printing technology for electrode fabrication enables construction of amperometric devices suitable for combination of several enzyme electrodes. To develop a biosensor array for characterisation of wastewaters, tyrosinase and horseradish peroxidase (HRP) or cholinesterase-modified electrodes were combined on the same array. The behaviour of the tyrosinase-modified electrode in the presence of hydrogen peroxide (required co-substrate for the HRP-modified electrode) and acetylthiocholine chloride (required co-substrate for cholinesterase) was studied. Performance of bi-enzyme biosensor arrays in the batch mode and in the flow-injection system are discussed.
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PMID:Screen-printed multienzyme arrays for use in amperometric batch and flow systems. 1285 95

Four wastewater samples of different treatment qualities; untreated, alarm, alert and normal, from a Swedish chemi-thermo-mechanical pulp mill and pure water were investigated using an amperometric bio-electronic tongue in a batch cell. The aim was to explore enzymatically modified screen-printed amperometric sensors for the discrimination of wastewater quality and to counteract the inherent drift. Seven out of eight platinum electrodes on the array were modified with four different enzymes; tyrosinase, horseradish peroxidase, acetyl cholinesterase and butyryl cholinesterase. At a constant potential the current intensity on each sensor was measured for 200s, 100s before injection and 100s after injection of the sample. The dynamic biosensor response curves from the eight sensors were used for principal component analysis (PCA). A simple baseline and sensitivity correction equivalent to multiplicative drift correction (MDC), using steady state intensities of reference sample (catechol) recordings, was employed. A clear pattern emerged in perfect agreement with prior knowledge of the samples explaining 97% of the variation in the data by two principal components (PCs). The first PC described the treatment quality of the samples and the second PC described the difference between treated and untreated samples. Horseradish peroxidase and pure platinum sensors were found to be the determinant sensors, while the rest did not contribute much to the discrimination. The wastewater samples were characterized by the chemical oxygen demand (COD), biological oxygen demand (BOD), total organic carbon (TOC), inhibition of nitrification, inhibition of respiration and toxicity towards Vibrio fischeri using Microtox, the freshwater alga Pseudokirchneriella subcapita and the freshwater crustacean Daphnia magna.
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PMID:Chemometric exploration of an amperometric biosensor array for fast determination of wastewater quality. 1620 74

Neuropathy target esterase (NTE) is a membrane protein found in human neurons and other cells, including lymphocytes. Binding of certain organophosphorus (OP) compounds to NTE is believed to cause OP-induced delayed neuropathy (OPIDN), a type of paralysis for which there is no effective treatment. Mutations in NTE have also been linked with serious neurological diseases, such as motor neuron disease. This paper describes development of the first nanostructured biosensor interface containing a catalytically active fragment of NTE known as NEST. The biosensor was fabricated using the layer-by-layer assembly approach, by immobilizing a layer of NEST on top of multilayers consisting of a polyelectrolyte (poly-L-lysine) and an enzyme (tyrosinase). The biosensor has a response time on the order of seconds and gives a concentration-dependent decrease in sensor output in response to a known NEST (and NTE) inhibitor. Potential applications of the biosensor include screening OP compounds for NTE inhibition and investigating the enzymology of wild-type and mutant forms of NTE. Although the development of a NEST biosensor was the primary purpose of this study, we found that the approach developed for NEST could also be extended to measure the activity of other esterases involved in neural processes, such as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). On the basis of measured sensitivities, phenyl valerate was the preferred substrate for NEST and BChE, whereas phenyl acetate was better for AChE.
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PMID:Nanostructured biosensor for measuring neuropathy target esterase activity. 1755 96

The screen-printed four-electrode system was used as the amperometric transducer for determination of phenols and pesticides using immobilised tyrosinase, peroxidase, acetylcholinesterase and butyrylcholinesterase. Acetylthiocholine chloride was chosen as substrate for cholinesterases to measure inhibition by pesticides, hydrogen peroxide served as co-substrate for peroxidase to measure phenols. The compatibility of hydrolases and oxidoreductases working in the same array was studied. The detection of p-cresol, catechol and phenol as well as of pesticides including carbaryl, heptenophos and fenitrothion was carried out in flow-through and steady state arrangements. In addition, the effects of heavy metals (Cu(2+), Cd(2+), Fe(3+)), fluoride (NaF), benzene and dimethylsulphoxide on cholinesterase activities were evaluated. It was demonstrated that electrodes modified with hydrolases and oxidoreductases can function in the same array. The achieved R.S.D. values obtained for the flow system were below 4% for the same sensor and less than 10% within a group of five sensors. For the steady state system, R.S.D.s were approximately twice higher. One assay was completed in less than 6min. The limit of detection for catechol using tyrosinase was equal to 0.35 and 1.7muM in the flow and steady state systems, respectively. On the contrary, lower limits of detection for pesticides were achieved in the steady state system-carbaryl 26nM, heptenophos 14nM and fenitrothion 0.58muM.
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PMID:Multienzyme electrochemical array sensor for determination of phenols and pesticides. 1896 6

The members of Scutellaria L. (Lamiaceae) is known to be rich particularly in flavonoids and among them, S. baicalensis has been recorded to be used for memory-enhancing purpose. Therefore, we initiated a study to screen the methanol extracts prepared from the aerial parts of 33 Turkish Scutellaria species for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, which are the key enzymes taking place in pathogenesis of Alzheimer's disease. Besides, the methanol extracts were tested in vitro against another enzyme, tyrosinase, which is associated with melanin hyperpigmentation. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenger effect, ferrous ion-chelating ability, and ferric-reducing antioxidant power (FRAP) of the ethyl acetate and methanol extracts were also determined. AChE, BChE, and tyrosinase inhibition of the extracts were performed on ELISA microplate reader by spectrophotometric method. The extracts showed weak inhibition against AChE and BChE, while the best tyrosinase inhibition was caused by the methanol extract of S. brevibracteata subsp. subvelutina. The extracts had a very high DDPH radical scavenging effect and moderate antioxidant activity in ferrous ion-chelating and FRAP tests.
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PMID:Acetylcholinesterase, butyrylcholinesterase, and tyrosinase inhibition studies and antioxidant activities of 33 Scutellaria L. taxa from Turkey. 2002 60

Pesticides are released intentionally into the environment and, through various processes, contaminate the environment. Three of the main classes of pesticides that pose a serious problem are organochlorines, organophosphates and carbamates. While pesticides are associated with many health effects, there is a lack of monitoring data on these contaminants. Traditional chromatographic methods are effective for the analysis of pesticides in the environment, but have limitations and prevent adequate monitoring. Enzymatic methods have been promoted for many years as an alternative method of detection of these pesticides. The main enzymes that have been utilised in this regard have been acetylcholinesterase, butyrylcholinesterase, alkaline phosphatase, organophosphorus hydrolase and tyrosinase. The enzymatic methods are based on the activation or inhibition of the enzyme by a pesticide which is proportional to the concentration of the pesticide. Research on enzymatic methods of detection, as well as some of the problems and challenges associated with these methods, is extensively discussed in this review. These methods can serve as a tool for screening large samples which can be followed up with the more traditional chromatographic methods of analysis.
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PMID:Review on the use of enzymes for the detection of organochlorine, organophosphate and carbamate pesticides in the environment. 2105 90


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