Organophosphorus Insecticide
Mostrando 13-24 de 25 artigos, teses e dissertações.
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13. Delayed neuropathy after organophosphorus insecticide (Dipterex) poisoning: a clinical, electrophysiological and nerve biopsy study.
Clinical, electrophysiological and histological findings in four patients accidentally poisoned with the organophosphorus insecticide Dipterex are reported. Three to five weeks after insecticide ingestion signs of a distal sensorimotor (preponderantly motor) neuropathy occurred. The patients complained of paraesthesia in the lower limbs, and two of them of v
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14. Transfer and expression of an organophosphate insecticide-degrading gene from Pseudomonas in Drosophila melanogaster.
The organophosphorus acid hydrolases represent a distinct class of enzymes that catalyze the hydrolysis of a variety of organophosphate substrates, including many insecticides and their structural analogues. The plasmid-borne opd gene of Pseudomonas diminuta strain MG specifies an organophosphorus acid hydrolase, a phosphotriesterase, that has been well char
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15. Trithion Poisoning
Nineteen cases of poisoning by the organophosphorus insecticide trithion (O,O-diethyl S-p-chlorophenylthiomethyl phosphorodithioate) are reported among workers on a sugarcane estate in Trinidad. There were no fatalities. Whole blood cholinesterase values determined by a portable field kit are given for some cases. The insecticide was applied as a dust under
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16. Dominance of Insecticide Resistance Presents a Plastic Response
Dominance level of insecticide resistance provided by one major gene (an insensitive acetylcholinesterase) in the mosquito Culex pipiens was studied in two distinct environments. Dominance level was found to be very different between environments, varying from almost complete dominance to almost recessive when either propoxur (a carbamate insecticide) or chl
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17. Effect of two organophosphorus insecticides on the phosphate-dissolving soil bacteria.
Dimethoate and malathion added to soil at 10 and 100 microgram/g caused an initial stimulation of CO2 production. Total counts of bacterial propagules were increased. All insecticide applications increased bacteria producing phospholipases from week 1 until week 4 after the application; bacteria then returned to the original levels.
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18. ALTERATIONS IN SERUM ENZYMES AFTER REPEATED EXPOSURE TO MALATHION
The alterations in serum pseudo-cholinesterase, transaminases, and aldolase observed in 12 agricultural workers exposed to the organo-phosphorus insecticide, malathion, over a period of six months are recorded. A comparison with a series of unselected controls and a series of manual workers is made. Evidence is produced that the majority of the agricultural
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19. Bacterial reduction of fensulfothion and its hydrolysis product 4-methylsulfinyl phenol.
Oxygen-limited cultures of Klebsiella pneumoniae reduced 4-methylsulfinyl phenol to 4-methylthiophenol. A study of the effect of 4-methylthiophenol on the growth of K. pneumoniae revealed that the specific growth rate was retarded by 40% in the presence of 200 micrograms of the phenol per ml. A soil bacterium, Hafnia sp., was isolated that could reduce the o
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20. Parathion utilization by bacterial symbionts in a chemostat.
A continuous-culture device was used to select and enrich for microorganisms, from sewage and agricultural runoff, that were capable of using the organophosphorus insecticide parathion as a sole growth substrate. Parathion was dissimilated by the highly acclimated symbiotic activities of Pseudomonas stutzeri, which non-oxidatively and cometabolically hydroly
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21. Effect of Four Organophosphorus Insecticides on Microbial Activities in Soil 1
Laboratory tests were conducted with four organophosphorus insecticides, Bay 37289 (O-ethyl O-2,4,5-trichlorophenyl ethylphosphonothioate), diazinon [O,O-diethyl O-(2-isopropyl-4-methyl-6-pyrimidinyl) phosphorothioate], Dursban (O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate), and Zinophos (O,O-diethyl O-2-pyrazinyl phosphorothioate), applied to a
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22. Characterization of amplification core and esterase B1 gene responsible for insecticide resistance in Culex.
Organophosphorus insecticide (OP) resistance in several Culex species is associated with increased esterase activity resulting from amplification of the corresponding structural gene. In Culex pipiens quinquefasciatus, high levels of OP resistance (approximately 800 times) are due to the esterase B1 gene, which is amplified at least 250-fold. This gene has n
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23. A single amino acid substitution converts a carboxylesterase to an organophosphorus hydrolase and confers insecticide resistance on a blowfly
Resistance to organophosphorus (OP) insecticides is associated with decreased carboxylesterase activity in several insect species. It has been proposed that the resistance may be the result of a mutation in a carboxylesterase that simultaneously reduces its carboxylesterase activity and confers an OP hydrolase activity (the “mutant ali-esterase hypothesis�
The National Academy of Sciences of the USA.
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24. Toxicological Properties of the Organophosphorus Insecticide Dimethoate
The results are presented of extensive toxicological studies on the systemic organophosphate insecticide dimethoate, and compared with published results from other laboratories. It behaves as a typical indirect anticholinesterase, by conversion in the liver to at least four short-lived active metabolites, whose hydrolysis products are rapidly excreted, mainl