Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Temefos”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1975

Environmental impact of mosquito pesticides: influence of temefos on the brain acetylcholinesterase of killifish.

Temefos and six of its metabolites were tested for their capacity to inhibit the in vitro activity of brain acetylcholinesterase (AChE) of Fundulus heteroclitus. While temefos was not inhibitory at levels up to 10.7 mM in brain homogenate samples, its metabolites were active within the range of 2 X 10(-4)mM to 1.26 mM in causing a 50% reduction in the enzyme activity. Exposure of F. heteroclitus to temefos under laboratory conditions caused a reduction in AChE activity, which was proportional to the pesticide concentration and the exposure period. Visible symptoms of organophosphate poisoning were apparent only after the AChE inhibition reached 80%. F. heteroclitus and Cyprinidon variegatus exposed to 10 biweekly applications of temefos granules in the field showed no inhibition of brain AChE. However, exposure of F. heteroclitus to biweekly applications (four) of temefos emulsion caused a reduction in the enzyme (50%), but only in the pre-third application samples. A gradual increase in brain AChE occurred both in F. heteroclitus and C. variegatus as the season progressed from April to October.

Acetylcholinesterase↗
PubMed1976

Uptake of the mosquito larvicide Temefos by the salt marsh snail, New Jersey--1973-1974.

Uptake of the mosquito larvicide temefos (Abate) by the salt march snail (Melampus bidentatus Say) in New Jersey was measured by gas-chromatographic analysis. Measurable quantities of temefos were found in the snails within 1 day after the first treatment with a 2% granular formulation but 3 weeks elapsed before uptake occurred following treatment with a temefos emulsion. Residues in the snails exposed to the granular formulation were generally more than 10 times higher than those in snails exposed to the emulsion although application rates of the granular formulation were only about three times higher than those of the emulsion. Residues in snails exposed to the emulsion fell below detectable levels less than 3 weeks after cessation of treatments although measurable amounts were found in snails exposed to the granular formulation for more than 5 weeks after the last treatment. The persistence of temefos in M. bidentatus suggests the potential for its movement through food webs exposed to the granular formulation.

Animals↗
PubMed1976

Storage and analysis of samples of water, fish, and mud from environments contaminated with abate.

Methods for extraction, cleanup, and analysis of samples of water, mud, and fish containing trace quantities of Abate have been developed. Water was extracted by high-speed stirring of 10 ml of hexane in a 300-ml sample. The extracts were evaporated and analyzed by gas chromatography with a limit of detection of 0.00003 ppm. Dried mud samples were extracted by shaking with acetone. An aliquot of the acetone extract was diluted with water and the Abate extracted into 10 ml of hexane by high-speed stirring. The extracts were analyzed by gas chromatography. Fish were extracted with methylene chloride, cleaned up on a silica gel column, and analyzed by gas chromatography. The limit of sensitivity of the methods for mud and fish was found to be 0.001 ppm. Fish samples were stored for 3 weeks in 10% formalin containing 5% sodium thiosulfate without significant loss of Abate residues. A biological magnification of greater than 100 was observed in fish exposed to Abate for 16 hr at concentrations of 0.02 and 0.002 ppm.

Animals↗
PubMed1992

Sensitivity and accuracy of a bio-assay for the determination of the concentration of residual pesticide in natural water bodies.

Determination of pesticide levels in natural water bodies requires complex chemical methods not always available in tropical countries where such control programmes are implemented. Apart from chemical methods, effectiveness of treatment can be estimated by mortality of target and non-target species. But the latter criteria do not permit a good appraisal of dispersion and residual activity of pesticide. We propose here a simple and cheap bio-assay adaptable to water-borne vector or intermediate host control programmes. Results obtained with the bio-assay were compared with those obtained with gas liquid chromatography, a standard chemical method.

Aedes↗
PubMed1985

A small scale field trial with Temephos (Abate) for the control of four species of Mansonia (Mansonioides) (Diptera: Culicidae) in Thailand.

A 60-week control experiment with Temephos (Abate) against a largely isolated population of Mansonia annulata, Ma. annulifera, Ma. indiana and Ma. uniformis was carried out in a pool of 1.2 ha area and average depth of over 2 m in southern Thailand. Floating paper tea bags containing 24 g of 1% Abate sand granules were applied in two rounds at a density of 1 bag 4 m-2. Each round consisted of five applications at intervals of 13 days. During the application rounds mosquito larvae disappeared completely from the pool. This apparent effect of Abate was confirmed by bioassays made with pool water and larvae of Culex quinquefasciatus. Inactivation of Abate was linear during one week, with a slope of 5.8% per day. Adult densities dropped during the application rounds and, over a period of 48 weeks, were 78-85% less than during the corresponding time of the preceding reference year. The annual pattern of adult abundance that normally shows distinct seasonal peaks was strongly altered, although meterological data were comparable to the reference year.

Animals↗
PubMed2022

Expansive and Diverse Phenotypic Landscape of Field Aedes aegypti (Diptera: Culicidae) Larvae with Differential Susceptibility to Temephos: Beyond Metabolic Detoxification.

Arboviruses including dengue, Zika, and chikungunya are amongst the most significant public health concerns worldwide. Arbovirus control relies on the use of insecticides to control the vector mosquito Aedes aegypti (Linnaeus), the success of which is threatened by widespread insecticide resistance. The work presented here profiled the gene expression of Ae. aegypti larvae from field populations of Ae. aegypti with differential susceptibility to temephos originating from two Colombian urban locations, Bello and Cúcuta, previously reported to have distinctive disease incidence, socioeconomics, and climate. We demonstrated that an exclusive field-to-lab (Ae. aegypti strain New Orleans) comparison generates an over estimation of differential gene expression (DGE) and that the inclusion of a geographically relevant field control yields a more discrete, and likely, more specific set of genes. The composition of the obtained DGE profiles is varied, with commonly reported resistance associated genes including detoxifying enzymes having only a small representation. We identify cuticle biosynthesis, ion exchange homeostasis, an extensive number of long noncoding RNAs, and chromatin modelling among the differentially expressed genes in field resistant Ae. aegypti larvae. It was also shown that temephos resistant larvae undertake further gene expression responses when temporarily exposed to temephos. The results from the sampling triangulation approach here contribute a discrete DGE profiling with reduced noise that permitted the observation of a greater gene diversity, increasing the number of potential targets for the control of insecticide resistant mosquitoes and widening our knowledge base on the complex phenotypic network of the Ae. aegypti response to insecticides.

Aedes↗