Journal articles: 'Organophosphate neurotoxics'

1

Eyer, P. "Review : Neuropsychopathological changes by organophosphorus compounds — a review." Human & Experimental Toxicology 14, no. 11 (November 1995): 857–64. http://dx.doi.org/10.1177/096032719501401101.

Full text

Abstract:

1 Available literature dealing with neuropsychopathologi cal changes after exposure to organophosphate insecti cides is reviewed. 2 Subacute neurological sequelae following acute organophosphate intoxication include the 'intermediate syndrome', probably a myopathy elicited by excess acetylcholine, and the 'organophosphate-induced delayed neuropathy' (OPIDN), which is caused by particularly neurotoxic organophosphates that inhibit neuropathy target esterase. 3 Long-term toxic effects affecting behaviour as well as mental and visual functions are occasionally observed after exposure to high doses of organophosphates with repeated acute, clinically significant intoxications. 4 The available data do not indicate that asymptomatic exposure to organophosphates is connected with an increasing risk of delayed or permanent neuro psychopathological effects.

APA, Harvard, Vancouver, ISO, and other styles

2

Altaf, S., F. Muhammad, B. Aslam, and MN Faisal. "Cell membrane enveloped polymeric nanosponge for detoxification of chlorpyrifos poison: In vitro and in vivo studies." Human & Experimental Toxicology 40, no. 8 (February 15, 2021): 1286–95. http://dx.doi.org/10.1177/0960327121993207.

Full text

Abstract:

Organophosphates are highly toxic compounds as they are involved in irreversible inhibition of acetylcholinesterase, causing various neurotoxic effects via acetylcholine accumulation throughout the nervous system. Traditional treatments for organophosphate poisoning are not effective enough to overcome all the toxic effects. There is a need for alternate treatment of life threatening poisoning of organophosphates. For this purpose a biomimetic nanosponge of poly (lactic- co-glycolic acid) is prepared, characterized and analysed as an antidote for organophosphate poisoning. In this nanosponge red blood cell membranes are used for coating poly lactic co-glycolic acid nanoparticles. In vitro studies are conducted to investigate the retention of acetylcholinesterase activity on the prepared nanosponge as well as to assess the scavenging ability of prepared nanosponge for model organophosphate, chlorpyrifos. In vivo studies are conducted to evaluate the detoxification potential of nanosponge in rabbit model, poisoned with chlorpyrifos. Hepatotoxicity and renal toxicity of nanosponge/chlorpyrifos complex is also studied in survived rabbits and the data is analysed statistically.

APA, Harvard, Vancouver, ISO, and other styles

3

Varfolomeyev, S., I. Kurockhin, A. Eremenko, and Elena Efremenko. "Chemical and biological safety: Biosensors and nanotechnological methods for the detection and monitoring of chemical and biological agents." Pure and Applied Chemistry 74, no. 12 (January 1, 2002): 2311–16. http://dx.doi.org/10.1351/pac200274122311.

Full text

Abstract:

The elaboration of highly sensitive and express methods for quantitative and qualitative detection and monitoring of chemical warfare agents (CWA), organophosphate and carbamate pesticides, compounds with delayed neurotoxicity, and pathogenic microorganisms and viruses is discussed. The application of potentiometric and amperometric biosensors, automatic biosensors discriminating the neurotoxins of different classes, is performed. The information about biosensors detecting the compounds with delayed neurotoxicity through the evaluation of “neurotoxic esterase”activity in the blood is presented. The use of immunochip technology for the detection of pathogenic microorganisms and viruses is demonstrated. The enzymatic methods of destruction of organophosphorus neurotoxins are considered as the base of new defense technology.

APA, Harvard, Vancouver, ISO, and other styles

4

Mason, Lisa H., Jordan P. Harp, and Dong Y. Han. "Pb Neurotoxicity: Neuropsychological Effects of Lead Toxicity." BioMed Research International 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/840547.

Full text

Abstract:

Neurotoxicity is a term used to describe neurophysiological changes caused by exposure to toxic agents. Such exposure can result in neurocognitive symptoms and/or psychiatric disturbances. Common toxic agents include heavy metals, drugs, organophosphates, bacterial, and animal neurotoxins. Among heavy metal exposures, lead exposure is one of the most common exposures that can lead to significant neuropsychological and functional decline in humans. In this review, neurotoxic lead exposure's pathophysiology, etiology, and epidemiology are explored. In addition, commonly associated neuropsychological difficulties in intelligence, memory, executive functioning, attention, processing speed, language, visuospatial skills, motor skills, and affect/mood are explored.

APA, Harvard, Vancouver, ISO, and other styles

5

Colovic, Mirjana, Danijela Krstic, Vesna Vasic, Aleksandra Bondzic, Gordana Uscumlic, and Slobodan Petrovic. "Organophosphorus insecticides: Toxic effects and bioanalytical tests for evaluating toxicity during degradation processes." Chemical Industry 67, no. 2 (2013): 217–30. http://dx.doi.org/10.2298/hemind120323060c.

Full text

Abstract:

Organophosphorus insecticides have been the most applied group of insecticides for the last two decades. Their main toxic effects are related to irreversible inactivation of acetylcholinesterase (AChE). Actually, they covalently bind to serine OH group in the enzyme active site forming phosphorylated enzyme that cannot hydrolyze acetylcholine. Organophosphorus insecticides in the environment undergo the natural degradation pathway including mainly homogeneous and heterogeneous hydrolysis (especially at high pH) generating non-inhibiting products. Additionally, thio organophosphates are easily oxidized by naturally present oxidants and UV light, forming more toxic and stable oxons. Thus, oxidative degradation procedures, generally referred as advanced oxidation processes (AOP), have been applied for their efficient removal from contaminated waters. The most applied bioassays to monitor the organophosphate toxicity i.e. the detoxification degree during AOP are Vibrio fischeri and AChE bioassays. Vibrio fischeri toxicity test exploits bioluminescence as the measure of luciferase activity of this marine bacterium, whereas AChE bioassay is based on AChE activity inhibition. Both bioanalytical techniques are rapid (several minutes), simple, sensitive and reproducible. Vibrio fischeri test seems to be a versatile indicator of toxic compounds generated in AOP for organophosphorus insecticides degradation. However, detection of neurotoxic AChE inhibitors, which can be formed in AOP of some organophosphates, requires AChE bioassays. Therefore, AChE toxicity test is more appropriate for monitoring the degradation processes of thio organophosphates, because more toxic oxo organophosphates might be formed and overlooked by Vibrio fischeri bioluminescence inhibition. In addition, during organophosphates removal by AOP, compounds with strong genotoxic potential may be formed, which cannot be detected by standard toxicity tests. For this reason, determination of incidence of micronuclei and cell proliferation index in cultivated human lymphocytes and fibroblasts is suitable for evaluation of organophosphorus insecticides and their break down products inducing cytogenetic damage.

APA, Harvard, Vancouver, ISO, and other styles

6

Xu, Tiantian, Ping Li, Siyu Wu, Lili Lei, and Defu He. "Tris(2-chloroethyl) phosphate (TCEP) and tris(2-chloropropyl) phosphate (TCPP) induce locomotor deficits and dopaminergic degeneration in Caenorhabditis elegans." Toxicology Research 6, no. 1 (2017): 63–72. http://dx.doi.org/10.1039/c6tx00306k.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Pérez-Legaspi, IA, R. Rico-Martínez, and JL Quintanar. "Reduced expression of exocytotic proteins caused by anti-cholinesterase pesticides in Brachionus calyciflorus (Rotifera: Monogononta)." Brazilian Journal of Biology 75, no. 3 (August 25, 2015): 759–65. http://dx.doi.org/10.1590/1519-6984.01614.

Full text

Abstract:

AbstractThe organophosphate and carbamate pesticides methyl-parathion and carbaryl have a common action mechanism: they inhibit acetylcholinesterase enzyme by blocking the transmission of nerve impulses. However, they can alter the expression of exocytotic membrane proteins (SNARE), by modifying release of neurotransmitters and other substances. This study evaluated the adverse effects of the pesticides methyl-parathion and carbaryl on expression of SNARE proteins: Syntaxin-1, Syntaxin-4 and SNAP-23 in freshwater rotifer Brachionus calyciflorus. Protein expression of these three proteins was analyzed before and after exposure to these two pesticides by Western Blot. The expression of Syntaxin-1, Syntaxin-4 and SNAP-23 proteins in B. calyciflorussignificantly decreases with increasing concentration of either pesticides. This suggests that organophosphates and carbamates have adverse effects on expression of membrane proteins of exocytosis by altering the recognition, docking and fusion of presynaptic and vesicular membranes involved in exocytosis of neurotransmitters. Our results demonstrate that the neurotoxic effect of anticholinesterase pesticides influences the interaction of syntaxins and SNAP-25 and the proper assembly of the SNARE complex.

APA, Harvard, Vancouver, ISO, and other styles

8

Lyagin, Ilya V., and Elena N. Efremenko. "Biomolecular engineering of biocatalysts hydrolyzing neurotoxic organophosphates." Biochimie 144 (January 2018): 115–21. http://dx.doi.org/10.1016/j.biochi.2017.10.023.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Prodanchulc, N. G., N. V. Kokshareva, P. G. Zminko, Yu S. Kagan, N. A. Shushurina, and S. V. Vekovshinina. "Prognostication of delayed neurotoxic effects of organophosphate pesticides." Toxicology Letters 95 (July 1998): 147. http://dx.doi.org/10.1016/s0378-4274(98)80586-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Wisudanti, Desie Dwi, Firman Herdiana, and Tegar Syaiful Qodar. "Diazinon Toxicity to Kidney and Liver of Wistar Male Rats in terms of Biochemical and Histopathological Parameters." Journal of Agromedicine and Medical Sciences 5, no. 2 (June 29, 2019): 51. http://dx.doi.org/10.19184/ams.v5i2.11575.

Full text

Abstract:

Diazinon is an organophosphate type pesticide that is still often used by farmers in Indonesia, with the effect of inhibiting the acetylcholinesterase enzyme, giving rise to the accumulation of acetylcholine in the synapse gap which will lead to incoordination, convulsions and death in insect pests. Apart from having the neurotoxic effects of diazinone it can also damage cells through the mechanism of oxidative stress. Diazinone poisoning has a high potential to cause damage to the kidney organs, because the diazinone excretion pathway and its active metabolites are through the urinary system. The purpose of this study was to determine the effect of diazinone on the liver and renal wistar male kidney. Diazinone dosage of 40 mg / kgBW, given to mice twice a day for 5 days, with each given as much as 5 ml using the gastric sonde. The research sample was in the form of rat blood taken intracardiac to examine BUN levels, serum creatinine, SGOT, SGPT, and GSH, then kidney and liver rats were taken to make histopathological preparations and MDA examinations. Analysis of this research data using the T-test for all variables. There were significant differences between groups of rats given diazinone and groups of rats not given diazinone based on levels of BUN, creatinine, SGOT, SGPT, GSH and MDA. In the group of mice not given diazinone, kidney histopathology was better than those given diazinon. Keywords: diazinon, pesticides, organophosphates

APA, Harvard, Vancouver, ISO, and other styles

11

Kim, J. W., E. I. Rainina, W. W. Mulbry, C. R. Engler, and J. R. Wild. "Enhanced-Rate Biodegradation of Organophosphate Neurotoxins by Immobilized Nongrowing Bacteria." Biotechnology Progress 18, no. 3 (June 7, 2002): 429–36. http://dx.doi.org/10.1021/bp0200346.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Simonian, A. ?L, A. ?W Flounders, and J. ?R Wild. "FET-Based Biosensors for The Direct Detection of Organophosphate Neurotoxins." Electroanalysis 16, no. 22 (November 2004): 1896–906. http://dx.doi.org/10.1002/elan.200403078.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Hong, Marjorie S., Evguenia Rainina, Janet K. Grimsley, Bruce E. Dale, and James R. Wild. "Neurotoxic Organophosphate Degradation with Polyvinyl Alcohol Gel-Immobilized Microbial Cells." Bioremediation Journal 2, no. 2 (September 1998): 145–57. http://dx.doi.org/10.1080/10889869891214277.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Michotte, A., I. Van Dijck, V. Maes, and H. D’Haenen. "Ataxia as the Only Delayed Neurotoxic Manifestation of Organophosphate Insecticide Poisoning." European Neurology 29, no. 1 (1989): 23–26. http://dx.doi.org/10.1159/000116371.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Comfort, Nicole, and Diane B. Re. "Sex-Specific Neurotoxic Effects of Organophosphate Pesticides Across the Life Course." Current Environmental Health Reports 4, no. 4 (October 23, 2017): 392–404. http://dx.doi.org/10.1007/s40572-017-0171-y.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Mutch, Elaine, Peter G. Blain, and Faith M. Williams. "Interindividual Variations in Enzymes Controlling Organophosphate Toxicity in Man." Human & Experimental Toxicology 11, no. 2 (March 1992): 109–16. http://dx.doi.org/10.1177/096032719201100209.

Full text

Abstract:

1 Interindividual variations in an unexposed population have been defined for five enzymes involved in organophosphate (OP) toxicity. The enzymes measured were: red blood cell acetylcholinesterase (AChE), lymphocyte neuropathy target esterase (NTE), serum cholinesterase (ChE), serum paraoxonase and serum arylesterase. 2 AChE and arylesterase were normally distributed in the population whilst the distribution of NTE, ChE and paraoxonase deviated significantly from normal. 3 Assay precision and intra-individual variability were measured for each of the enzymes; the effect on interindividual variation was assessed. 4 Variations in enzyme activities between individuals could have profound effects on susceptibility to OP toxicity. Prior determination of these enzymes may be predictive of susceptibility. 5 Lymphocyte NTE has some limitations as an indicator of exposure to neurotoxic OPs.

APA, Harvard, Vancouver, ISO, and other styles

17

Kim, Chang Sup, Jeong Hyun Seo, Dong Gyun Kang, and Hyung Joon Cha. "Engineered whole-cell biocatalyst-based detoxification and detection of neurotoxic organophosphate compounds." Biotechnology Advances 32, no. 3 (May 2014): 652–62. http://dx.doi.org/10.1016/j.biotechadv.2014.04.010.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Azam, Sarwar, Sunil Parthasarathy, Chhaya Singh, Shakti Kumar, and Dayananda Siddavattam. "Genome Organization and Adaptive Potential of Archetypal Organophosphate Degrading Sphingobium fuliginis ATCC 27551." Genome Biology and Evolution 11, no. 9 (August 27, 2019): 2557–62. http://dx.doi.org/10.1093/gbe/evz189.

Full text

Abstract:

Abstract Sphingobium fuliginis ATCC 27551, previously classified as Flavobacterium sp. ATCC 27551, degrades neurotoxic organophosphate insecticides and nerve agents through the activity of a membrane-associated organophosphate hydrolase. This study was designed to determine the complete genome sequence of S. fuliginis ATCC 27551 to unravel its degradative potential and adaptability to harsh environments. The 5,414,624 bp genome with a GC content of 64.4% is distributed between two chromosomes and four plasmids and encodes 5,557 proteins. Of the four plasmids, designated as pSF1, pSF2, pSF3, and pSF4, only two (pSF1 and pSF2) are self-transmissible and contained the complete genetic repertoire for a T4SS. The other two plasmids (pSF3 and pSF4) are mobilizable and both showed the presence of an oriT and relaxase-encoding sequences. The sequence of plasmid pSF3 coincided with the previously determined sequence of pPDL2 and included an opd gene encoding organophosphate hydrolase as a part of the mobile element. About 15,455 orthologous clusters were identified from among the cumulatively annotated genes of 49 Sphingobium species. Phylogenetic analysis done using the core genome consisting of 802 orthologous clusters revealed a close relationship between S. fuliginis ATCC 27551 and bacteria capable of degradation of polyaromatic hydrocarbon compounds. Genes coding for transposases, efflux pumps conferring resistance to heavy metals, and TonR-type outer membrane receptors are selectively enriched in the genome of S. fuliginis ATCC 27551 and appear to contribute to the adaptive potential of the organism to challenging and harsh environments.

APA, Harvard, Vancouver, ISO, and other styles

19

Lutfiyah, Lailatul. "Sublethal Toxicity of Organophosphate Pesticides and its Effect on Hematology Parameter, Histopatology Hematopoietic Organ of Silver Rasbora (Rasbora argyrotaenia)." Journal of Aquaculture Science 5, no. 2 (October 26, 2020): 68. http://dx.doi.org/10.31093/joas.v5i2.94.

Full text

Abstract:

Pesticides are pollutants that are found in rice fields and rivers. Pesticides that are often used by farmers in Indonesia in eradicating insects are organophosphate insecticides, where they can eradicate insects that are very toxic to fish due to strong neurotoxic substances that inhibit AchE (Acetylcholinesterase) activity. The research aims to examine the effect of organophosphate pesticides on hematology and histopathology of hematopoietic organs in silver rasbora fish. The research method used is an experimental method with a CRD. The parameters observed were hematology and histopathology hematopoietic organ (liver and kidney). The results of this study showed a hematological change in silver rasbora fish where there was a decrease in total erythrocytes (0,59±0,004) and hemoglobin (2,5±0,1) while total leukocytes increased (245,35±15,78). Also, there are differential changes in leukocytes, namely an increased in the number of monocytes (5±1) and neutrophils (24±3), but lymphocytes have decreased in number (72±1). The Histopathology of the fish liver also can found in this research, those damages that are found are erythrocyte infiltration, necrosis picnosis, and karyolysis. Histopathology of fish kidney also can found cloudy sweling, necrosis karyolysis and tubular necrosis.

APA, Harvard, Vancouver, ISO, and other styles

20

Scholz, Nathaniel L., Nathan K. Truelove, Barbara L. French, Barry A. Berejikian, Thomas P. Quinn, Edmundo Casillas, and Tracy K. Collier. "Diazinon disrupts antipredator and homing behaviors in chinook salmon (Oncorhynchus tshawytscha)." Canadian Journal of Fisheries and Aquatic Sciences 57, no. 9 (September 1, 2000): 1911–18. http://dx.doi.org/10.1139/f00-147.

Full text

Abstract:

Neurotoxic pesticides are known to contaminate surface waters that provide habitat for salmonids, including some listed for protection under the U.S. Endangered Species Act. Despite their widespread use, the impacts of these pesticides on the neurological health of wild salmon are not well understood. Of particular concern are the organophosphate and carbamate insecticides that block synaptic transmission by inhibiting neuronal acetylcholinesterase. Here we assess the effects of diazinon, an organophosphate insecticide, on alarm pheromone induced antipredator responses and homing behavior in chinook salmon (Oncorhynchus tshawytscha). Nominal exposure concentrations (0.1, 1.0, and 10.0 µg·L-1) were chosen to emulate diazinon pulses in the natural environment. In the antipredator study, diazinon had no effect on swimming behavior or visually guided food capture. However, the pesticide significantly inhibited olfactory-mediated alarm responses at concentrations as low as 1.0 µg·L-1. Similarly, homing behavior was impaired at 10.0 µg·L-1. Our results suggest that olfactory-mediated behaviors are sensitive to anticholinesterase neurotoxicity in salmonids and that short-term, sublethal exposures to these insecticides may cause significant behavioral deficits. Such deficits may have negative consequences for survival and reproductive success in these fish.

APA, Harvard, Vancouver, ISO, and other styles

21

Hossain, Md Mokarrom, Shaikh Nayeem Faisal, Chang Sup Kim, Hyung Joon Cha, Sang Cheol Nam, and Hye Jin Lee. "Amperometric proton selective strip-sensors with a microelliptic liquid/gel interface for organophosphate neurotoxins." Electrochemistry Communications 13, no. 6 (June 2011): 611–14. http://dx.doi.org/10.1016/j.elecom.2011.03.024.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Ferchmin, P. A., Dinely Perez, A. Henrique Martins, Brenda L. Cuadrado, Marimee Carrasco, and Vesna A. Eterovic. "A novel nicotinic antagonist protects the function of hippocampal slices against neurotoxic organophosphates." Biochemical Pharmacology 78, no. 7 (October 2009): 904–5. http://dx.doi.org/10.1016/j.bcp.2009.06.043.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Zhang, Yu, Jiao An, Wei Ye, Guangyu Yang, Zhi-Gang Qian, Hai-Feng Chen, Li Cui, and Yan Feng. "Enhancing the Promiscuous Phosphotriesterase Activity of a Thermostable Lactonase (GkaP) for the Efficient Degradation of Organophosphate Pesticides." Applied and Environmental Microbiology 78, no. 18 (July 13, 2012): 6647–55. http://dx.doi.org/10.1128/aem.01122-12.

Full text

Abstract:

ABSTRACTThe phosphotriesterase-like lactonase (PLL) enzymes in the amidohydrolase superfamily hydrolyze various lactones and exhibit latent phosphotriesterase activities. These enzymes serve as attractive templates forin vitroevolution of neurotoxic organophosphates (OPs) with hydrolytic capabilities that can be used as bioremediation tools. Here, a thermostable PLL fromGeobacillus kaustophilusHTA426 (GkaP) was targeted for joint laboratory evolution with the aim of enhancing its catalytic efficiency against OP pesticides. By a combination of site saturation mutagenesis and whole-gene error-prone PCR approaches, several improved variants were isolated. The most active variant, 26A8C, accumulated eight amino acid substitutions and demonstrated a 232-fold improvement over the wild-type enzyme in reactivity (kcat/Km) for the OP pesticideethyl-paraoxon. Concomitantly, this variant showed a 767-fold decrease in lactonase activity with δ-decanolactone, imparting a specificity switch of 1.8 × 105-fold. 26A8C also exhibited high hydrolytic activities (19- to 497-fold) for several OP pesticides, including parathion, diazinon, and chlorpyrifos. Analysis of the mutagenesis sites on the GkaP structure revealed that most mutations are located in loop 8, which determines substrate specificity in the amidohydrolase superfamily. Molecular dynamics simulation shed light on why 26A8C lost its native lactonase activity and improved the promiscuous phosphotriesterase activity. These results permit us to obtain further insights into the divergent evolution of promiscuous enzymes and suggest that laboratory evolution of GkaP may lead to potential biological solutions for the efficient decontamination of neurotoxic OP compounds.

APA, Harvard, Vancouver, ISO, and other styles

24

Kuo, Louis Y., Andrew Bennett, and Qianli Miao. "Heterogeneous Organophosphate Ethanolysis: Degradation of Phosphonothioate Neurotoxin by a Supported Molybdenum Peroxo Polymer." Inorganic Chemistry 56, no. 16 (August 2, 2017): 10013–20. http://dx.doi.org/10.1021/acs.inorgchem.7b01545.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Raheja, Geetu, and Kiran Dip Gill. "Altered cholinergic metabolism and muscarinic receptor linked second messenger pathways after chronic exposure to dichlorvos in rat brain." Toxicology and Industrial Health 23, no. 1 (February 2007): 25–37. http://dx.doi.org/10.1177/0748233707072490.

Full text

Abstract:

Chronic dichlorvos exposure (6mg/kg b.wt/day) for a period of 8 weeks resulted in significant reduction in body weight gain of the male Wistar rats. However, the dietary intake remained unchanged in experimental animals following dichlorvos treatment. Activity of the synthesizing enzyme of acetylcholine (ACh) ie, choline acetyltransferase, was found to be significantly increased and the activity of hydrolyzing enzyme, acetyl cholinesterase (AChE), was inhibited in all the three brain regions studied. Chronic dichlorvos treatment also caused significant reduction in both high affinity (HA) and low affinity (LA) choline uptake (CU), with maximal effect being observed in the brain stem followed by cerebellum and cerebrum. Muscarinic receptor binding was significantly decreased in brain stem and cerebellum as reflected in the decreased receptor number (Bmax), without any change in the binding affinity (Kd) of the receptors. Dichlorvos treatment caused marked inhibition in cAMP synthesis as indicated by decreased adenylate cyclase activity as well as cAMP levels in cerebrum, cerebellum and brain stem. Our study shows that organophosphates may interact with muscarinic receptor-linked second messenger system and this could be a potential mechanism for the neurotoxic effects observed after repeated exposure to low levels of organophosphates, which are unexplainable on the basis of cholinergic hyperactivity. Toxicology and Industrial Health 2007; 23: 25—37.

APA, Harvard, Vancouver, ISO, and other styles

26

Moretto, Angelo, and Marcello Lotti. "Promotion of Peripheral Axonopathies by Certain Esterase Inhibitors." Toxicology and Industrial Health 9, no. 6 (November 1993): 1037–46. http://dx.doi.org/10.1177/074823379300900604.

Full text

Abstract:

Certain esterase inhibitors were found to exacerbate the clinical signs of polyneuropathy caused by various neurotoxic compounds and to delay the recovery from nerve crush. This phenomenon is referred to as promotion of axonopathies. The molecular target of promotion has not yet been identified. However, all known promoters are also inhibitors of neuropathy target esterase (NTE), the putative target of organophosphate neuropathy, but it has been shown that the target of promotion is unlikely to be NTE. Available data suggest that promoters might affect a target and a mechanism present in the nervous system that is not activated by axonal lesions. Promotion may be important to understand the physiological mechanism of nerve damage and repair. This finding also implies a changing perspective for the risk assessment of exposures to esterase inhibitors, some of which are used as pesticides and might be promoters.

APA, Harvard, Vancouver, ISO, and other styles

27

Schallreuter, Karin U., Nicholas C. J. Gibbons, Souna M. Elwary, Susan M. Parkin, and John M. Wood. "Calcium-activated butyrylcholinesterase in human skin protects acetylcholinesterase against suicide inhibition by neurotoxic organophosphates." Biochemical and Biophysical Research Communications 355, no. 4 (April 2007): 1069–74. http://dx.doi.org/10.1016/j.bbrc.2007.02.078.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Simonian, A. L., E. I. Rainina, and J. R. Wild. "A New Approach For Discriminative Detection of Organophosphate Neurotoxins in the Presence of Other Cholinesterase Inhibitors." Analytical Letters 30, no. 14 (November 1997): 2453–68. http://dx.doi.org/10.1080/00032719708001757.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Zengerle, Michael, Florian Brandhuber, Christian Schneider, Franz Worek, Georg Reiter, and Stefan Kubik. "Highly efficient cyclosarin degradation mediated by a β-cyclodextrin derivative containing an oxime-derived substituent." Beilstein Journal of Organic Chemistry 7 (November 22, 2011): 1543–54. http://dx.doi.org/10.3762/bjoc.7.182.

Full text

Abstract:

The potential of appropriately substituted cyclodextrins to act as scavengers for neurotoxic organophosphonates under physiological conditions was evaluated. To this end, a series of derivatives containing substituents with an aldoxime or a ketoxime moiety along the narrow opening of the β-cyclodextrin cavity was synthesized, and the ability of these compounds to reduce the inhibitory effect of the neurotoxic organophosphonate cyclosarin on its key target, acetylcholinesterase, was assessed in vitro. All compounds exhibited a larger effect than native β-cyclodextrin, and characteristic differences were noted. These differences in activity were correlated with the structural and electronic parameters of the substituents. In addition, the relatively strong effect of the cyclodextrin derivatives on cyclosarin degradation and, in particular, the observed enantioselectivity are good indications that noncovalent interactions between the cyclodextrin ring and the substrate, presumably involving the inclusion of the cyclohexyl moiety of cyclosarin into the cyclodextrin cavity, contribute to the mode of action. Among the nine compounds investigated, one exhibited remarkable activity, completely preventing acetylcholinesterase inhibition by the (−)-enantiomer of cyclosarin within seconds under the conditions of the assay. Thus, these investigations demonstrate that decoration of cyclodextrins with appropriate substituents represents a promising approach for the development of scavengers able to detoxify highly toxic nerve agents.

APA, Harvard, Vancouver, ISO, and other styles

30

Oortgiesen, Marga, Regina G. D. M. van Kleef, Ruud Zwart, Ingeborg van den Beukel, and Henk P. M. Vijverberg. "Nicotinic Receptors of Different Species Exhibit Differential Sensitivities to Nitromethylene and Organophosphate Insecticides." Alternatives to Laboratory Animals 24, no. 3 (June 1996): 367–76. http://dx.doi.org/10.1177/026119299602400310.

Full text

Abstract:

The effects of nitromethylene heterocycle (NMH) and organophosphate (OP) insecticides were studied on nicotinic acetylcholine receptors (nAChR) in cultured cells of different species origin, in order to examine the selectivity of these compounds at the level of the target sites. In mouse muscle BC3H1, mouse NIE-115 and human SH-SY5Y neuroblastoma, and locust thoracic ganglion cells, the neurotransmitter, acetylcholine (ACh), induces a similar transient inward current. Dependent on the cell type, the six NMHs acted as agonists and/or antagonists on nAChR. Distinct agonistic effects of NMHs on nAChR are observed on insect neurons only. Further, NMHs potently block nicotinic responses in insects, while mammalian cells are only moderately affected. In all cases, the neuronal type nAChR was more sensitive to blocking than the endplate type nAChR in mammalian cells. Parathion and paraoxon at micromolar concentrations inhibit ACh-induced nicotinic inward currents. The insecticide, parathion, is a 50-fold more potent inhibitor than its acetyl-cholinesterase-inhibiting metabolite, paraoxon. Moderate differences in sensitivity to the blocking action of the OPs appear to exist among cells of different species. The results demonstrate that the experimental approach of fundamental electrophysiology and the use of cell lines are relevant tools for investigating the species specificity of neurotoxic compounds.

APA, Harvard, Vancouver, ISO, and other styles

31

Kuo, Louis Y., Kristina M. Dill, Yusef A. Shari'ati, Emily K. Bright, and Theresa McCormick. "Novel application of simple molybdates: Catalytic hydrolysis of an organophosphate neurotoxin under mild aqueous conditions." Inorganica Chimica Acta 466 (September 2017): 1–7. http://dx.doi.org/10.1016/j.ica.2017.05.007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Bellinato, Diogo Fernandes, Priscila Fernandes Viana-Medeiros, Simone Costa Araújo, Ademir J. Martins, José Bento Pereira Lima, and Denise Valle. "Resistance Status to the Insecticides Temephos, Deltamethrin, and Diflubenzuron in BrazilianAedes aegyptiPopulations." BioMed Research International 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/8603263.

Full text

Abstract:

Insecticides are still largely applied in public health to control disease vectors. In Brazil, organophosphates (OP) and pyrethroids (PY) are used againstAedes aegyptifor years. Since 2009 Insect Growth Regulators (IGR) are also employed in the control of larvae. We quantified resistance to temephos (OP), deltamethrin (PY), and diflubenzuron (IGR) ofA. aegyptisamples from 12 municipalities distributed throughout the country, collected between 2010 and 2012. High levels of resistance to neurotoxic insecticides were detected in almost all populations: RR95to temephos varied between 4.0 and 27.1; the lowest RR95to deltamethrin was 13.1, and values higher than 70.0 were found. In contrast, all samples were susceptible to diflubenzuron (RR95< 2.3). Biochemical tests performed with larvae and adults discarded the participation of acetylcholinesterase, the OP target, and confirmed involvement of the detoxifying enzymes esterases, mixed function oxidases, and glutathione-S-transferases. The results obtained were discussed taking into account the public chemical control component and the increase in the domestic use of insecticides during dengue epidemic seasons in the evaluated municipalities.

APA, Harvard, Vancouver, ISO, and other styles

33

Kuo, Louis Y., and Sara K. Glazier. "Stereochemical Inversion of Phosphonothioate Methanolysis by La(III) and Zn(II): Mechanistic Implications for the Degradation of Organophosphate Neurotoxins." Inorganic Chemistry 51, no. 1 (December 19, 2011): 328–35. http://dx.doi.org/10.1021/ic2016897.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Feng, Liping, Fengxiu Ouyang, Liangpo Liu, Xu Wang, Xia Wang, Yi-Ju Li, Amy Murtha, Heqing Shen, Junfeng Zhang, and Jun Jim Zhang. "Levels of Urinary Metabolites of Organophosphate Flame Retardants, TDCIPP, and TPHP, in Pregnant Women in Shanghai." Journal of Environmental and Public Health 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/9416054.

Full text

Abstract:

Flame retardants are widely used in consumer products to reduce their flammability. Previously used flame retardants have been sequentially banned due to their environmental and human toxicity. Currently, tris(1,3-dichloropropyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP) are among the most commonly used flame retardants. TDCIPP and TPHP are reproductive toxins and have carcinogenic, neurotoxic, and endocrine-disrupting properties. Although high levels of TDCIPP and TPHP have been found in drinking water, seawater, and office air in China, data regarding human exposure are lacking. In this study, we assessed the level of urinary TPHP and TDCIPP metabolites (DPHP and BDCIPP, resp.) in a cohort of pregnant women (N=23) from Shanghai, China, using liquid chromatography-tandem mass spectrometry. DPHP were detected in 100% urine samples, while only four urine samples had detectable level of BDCIPP in this cohort (17% detected). Geometric means of DPHP and BDCIPP concentrations were 1.1 ng/mL (interquartile range [IQR]: 0.6, 1.5 ng/mL) and 1.2 ng/mL (IQR: 0.6, 2.2 ng/mL), respectively. In this small cohort, urinary DPHP and BDCIPP levels were not significantly correlated with miscarriages, neonatal birthweight, gestational diabetes, or maternal age. These data suggest that exposure to TPHP is widespread, and they demonstrate the feasibility of using urinary biomarkers to measure exposures to modern flame-retardant chemicals.

APA, Harvard, Vancouver, ISO, and other styles

35

Makhaeva, Galina F., and Vladimir V. Malygin. "A stable preparation of hen brain neuropathy target esterase for rapid biochemical assessment of neurotoxic potential of organophosphates." Chemico-Biological Interactions 119-120 (May 1999): 551–57. http://dx.doi.org/10.1016/s0009-2797(99)00069-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Karami-Mohajeri, Somayyeh, and Mohammad Abdollahi. "Toxic influence of organophosphate, carbamate, and organochlorine pesticides on cellular metabolism of lipids, proteins, and carbohydrates." Human & Experimental Toxicology 30, no. 9 (November 11, 2010): 1119–40. http://dx.doi.org/10.1177/0960327110388959.

Full text

Abstract:

Pesticides, including organophosphate (OP), organochlorine (OC), and carbamate (CB) compounds, are widely used in agricultural and indoor purposes. OP and CB act as acetyl cholinesterase (AChE) inhibitors that affect lots of organs such as peripheral and central nervous systems, muscles, liver, pancreas, and brain, whereas OC are neurotoxic involved in alteration of ion channels. There are several reports about metabolic disorders, hyperglycemia, and also oxidative stress in acute and chronic exposures to pesticides that are linked with diabetes and other metabolic disorders. In this respect, there are several in vitro and in vivo but few clinical studies about mechanism underlying these effects. Bibliographic databases were searched for the years 1963–2010 and resulted in 1652 articles. After elimination of duplicates or irrelevant papers, 204 papers were included and reviewed. Results indicated that OP and CB impair the enzymatic pathways involved in metabolism of carbohydrates, fats and protein within cytoplasm, mitochondria, and proxisomes. It is believed that OP and CB show this effect through inhibition of AChE or affecting target organs directly. OC mostly affect lipid metabolism in the adipose tissues and change glucose pathway in other cells. As a shared mechanism, all OP, CB and OC induce cellular oxidative stress via affecting mitochondrial function and therefore disrupt neuronal and hormonal status of the body. Establishing proper epidemiological studies to explore exact relationships between exposure levels to these pesticides and rate of resulted metabolic disorders in human will be helpful.

APA, Harvard, Vancouver, ISO, and other styles

37

Cho, Catherine Mee-Hie, Ashok Mulchandani, and Wilfred Chen. "Bacterial Cell Surface Display of Organophosphorus Hydrolase for Selective Screening of Improved Hydrolysis of Organophosphate Nerve Agents." Applied and Environmental Microbiology 68, no. 4 (April 2002): 2026–30. http://dx.doi.org/10.1128/aem.68.4.2026-2030.2002.

Full text

Abstract:

ABSTRACT Organophosphorus hydrolase (OPH) is a bacterial enzyme that has been shown to degrade a wide range of neurotoxic organophosphate nerve agents. However, the effectiveness of degradation varies dramatically, ranging from highly efficient with paraoxon to relatively slow with methyl parathion. Sequential cycles of DNA shuffling and screening were used to fine-tune and enhance the activity of OPH towards poorly degraded substrates. Because of the inaccessibility of these pesticides across the cell membrane, OPH variants were displayed on the surface of Escherichia coli using the truncated ice nucleation protein in order to isolate novel enzymes with truly improved substrate specificities. A solid-phase top agar method based on the detection of the yellow product p-nitrophenol was developed for the rapid prescreening of potential variants with improved hydrolysis of methyl parathion. Two rounds of DNA shuffling and screening were carried out, and several improved variants were isolated. One variant in particular, 22A11, hydrolyzes methyl parathion 25-fold faster than does the wild type. Because of the success that we achieved with directed evolution of OPH for improved hydrolysis of methyl parathion, we believe that we can easily extend this method in creating other OPH variants with improved activity against poorly degraded pesticides such as diazinon and chlorpyrifos and nerve agents such as sarin and soman.

APA, Harvard, Vancouver, ISO, and other styles

38

Monnet-Tschudi, F., M.-G. Zurich, and P. Honegger. "Neurotoxicant-induced inflammatory response in three-dimensional brain cell cultures." Human & Experimental Toxicology 26, no. 4 (April 2007): 339–46. http://dx.doi.org/10.1177/0960327107074589.

Full text

Abstract:

Brain inflammatory response is triggered by the activation of microglial cells and astrocytes in response to various types of CNS injury, including neurotoxic insults. Its outcome is determined by cellular interactions, inflammatory mediators, as well as trophic and/or cytotoxic signals, and depends on many additional factors such as the intensity and duration of the insult, the extent of both the primary neuronal damage and glial reactivity and the developmental stage of the brain. Depending on particular circumstances, the brain inflammatory response can promote neuroprotection, regeneration or neurodegeneration. Glial reactivity, regarded as the central phenomenon of brain inflammation, has also been used as an early marker of neurotoxicity. To study the mechanisms underlying the glial reactivity, serum-free aggregating brain cell cultures were used as an in vitro model to test the effects of conventional neurotoxicants such as organophosphate pesticides, heavy metals, excitotoxins and mycotoxins. This approach was found to be relevant and justified by the complex cell—cell interactions involved in the brain inflammatory response, the variability of the glial reactions and the multitude of mediators involved. All these variables need to be considered for the elucidation of the specific cellular and molecular reactions and their consequences caused by a given chemical insult. Human & Experimental Toxicology (2007) 26, 339—346

APA, Harvard, Vancouver, ISO, and other styles

39

Rajaji, Umamaheswari, Sathishkumar Chinnapaiyan, Tse-Wei Chen, Shen-Ming Chen, G. Mani, Veerappan Mani, M. Ajmal Ali, Fahad M. A. Al-Hemaid, and M. Suliman El-Shikh. "Rational construction of novel strontium hexaferrite decorated graphitic carbon nitrides for highly sensitive detection of neurotoxic organophosphate pesticide in fruits." Electrochimica Acta 371 (March 2021): 137756. http://dx.doi.org/10.1016/j.electacta.2021.137756.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Mersal, Gaber A. M., Hamdy S. El-Sheshtawy, Mohammed A. Amin, Nasser Y. Mostafa, Amine Mezni, Sarah Alharthi, Rabah Boukherroub, and Mohamed M. Ibrahim. "Simultaneous Hydrolysis and Detection of Organophosphate by Benzimidazole Containing Ligand-Based Zinc(II) Complexes." Crystals 11, no. 6 (June 21, 2021): 714. http://dx.doi.org/10.3390/cryst11060714.

Full text

Abstract:

The agricultural use of organophosphorus pesticides is a widespread practice with significant advantages in crop health and product yield. An undesirable consequence is the contamination of soil and groundwater by these neurotoxins resulting from over application and run-off. Here, we design and synthesize the mononuclear zinc(II) complexes, namely, [Zn(AMB)2Cl](ClO4) 1 and [Zn(AMB)2(OH)](ClO4) 2 (AMB = 2-aminomethylbenzimidazole), as artificial catalysts inspired by phosphotriesterase (PTE) for the hydrolysis of organophosphorus compounds (OPs) and simultaneously detect the organophosphate pesticides such as fenitrothion and parathion. Spectral and DFT (B3LYP/Lanl2DZ) calculations revealed that complexes 1 and 2 have a square-pyramidal environment around zinc(II) centers with coordination chromophores of ZnN4Cl and ZnN4O, respectively. Both 1 and 2 were used as a modifier in the construction of a biomimetic sensor for the determination of toxic OPs, fenitrothion and parathion, in phosphate buffer by square wave voltammetry. The hydrolysis of OPs using 1 or 2 generates p-nitrophenol, which is subsequently oxidized at the surface of the modified carbon past electrode. The catalytic activity of 2 was higher than 1, which is attributed to the higher electronegativity of the former. The oxidation peak potentials of p-nitrophenol were obtained at +0.97 V (vs. Ag/AgCl) using cyclic voltammetry (CV) and +0.88 V (vs. Ag/AgCl) using square wave voltammetry. Several parameters were investigated to evaluate the performance of the biomimetic sensor obtained after the incorporation of zinc(II) complex 1 and 2 on a carbon paste electrode (CPE). The calibration curve showed a linear response ranging between 1.0 μM (0.29 ppm) and 5.5 μM (1.6 ppm) for fenitrothion and 1.0 μM (0.28 ppm) and 0.1 μM (0.028 ppm) for parathion with a limit of detection (LOD) of 0.08 μM (0.022 ppm) and 0.51 μM (0.149 ppm) for fenitrothion and parathion, respectively. The obtained results clearly demonstrated that the CPE modified by 1 and 2 has a remarkable electrocatalytic activity towards the hydrolysis of OPs under optimal conditions.

APA, Harvard, Vancouver, ISO, and other styles

41

Zhou, Lang, Bryan Chin, and Alex L. Simonian. "Catalytic Hydrolysis of Tricresyl Phosphate by Ruthenium (III) Hydroxide and Iron (III) Hydroxide towards Sensing Application." Sensors 20, no. 8 (April 18, 2020): 2317. http://dx.doi.org/10.3390/s20082317.

Full text

Abstract:

Tricresyl phosphate (TCP) is an organophosphorous neurotoxin that has been detected in water, soil and air. Exposure to TCP in cockpit and cabin air poses a severe threat to flight safety and the health of the aircraft cabin occupants. Conventional methods for the detection of TCP in various samples are gas or liquid chromatography coupled to mass spectrometry, which are complex and expensive. To develop a simple low-cost methodology for the real-time monitoring of TCP in the environment, an effective catalyst is demanded for the hydrolysis of TCP under neutral condition. In this study, Ruthenium (III) hydroxide and Iron (III) hydroxide are found to facilitate the production of the alcoholysis and hydrolysis products of TCP, suggesting their role as a catalyst. With this finding, these metal hydroxides provide new potential to realize not only simple colorimetric or electrochemical detection of TCP, but also a simple detoxication strategy for TCP in environment. In addition, the catalytic capability of Ru (III) or Fe (III) hydroxide for TCP gives a hint that they can potentially serve as catalysts for the hydrolysis of alcolyolysis of many other organophosphate compounds.

APA, Harvard, Vancouver, ISO, and other styles

42

Baldissera, Matheus D., Carine F. Souza, Renato Zanella, Osmar D. Prestes, Adriana D. Meinhart, Aleksandro S. Da Silva, and Bernardo Baldisserotto. "Behavioral impairment and neurotoxic responses of silver catfish Rhamdia quelen exposed to organophosphate pesticide trichlorfon: Protective effects of diet containing rutin." Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology 239 (January 2021): 108871. http://dx.doi.org/10.1016/j.cbpc.2020.108871.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Dodd, CA, and BG Klein. "Pyrethroid and organophosphate insecticide exposure in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson’s disease: an immunohistochemical analysis of tyrosine hydroxylase and glial fibrillary acidic protein in dorsolateral striatum." Toxicology and Industrial Health 25, no. 1 (February 2009): 25–39. http://dx.doi.org/10.1177/0748233709102752.

Full text

Abstract:

The pyrethroid insecticide permethrin and the organophosphate insecticide chlorpyrifos can experimentally produce Parkinson’s disease (PD)-associated changes in the dopaminergic nigrostriatal pathway, short of frank degeneration, although at doses considerably higher than from a likely environmental exposure. The ability of permethrin (200 mg/kg), chlorpyrifos (50 mg/kg), or combined permethrin + chlorpyrifos to facilitate nigrostriatal damage in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (30 mg/kg) C57BL/6 mouse model of PD was investigated in three separate experiments. Tyrosine hydroxylase (TH) and glial fibrillary acidic protein (GFAP) immunohistochemistry assessed nigrostriatal degeneration or nigrostriatal damage more subtle than frank degeneration. Four fields in the dorsolateral caudate-putamen were examined at two rostrocaudal locations. The dopaminergic neurotoxin MPTP decreased striatal TH immunopositive neuropil and increased GFAP immunopositive neuropil. Neither permethrin nor chlorpyrifos, alone or in combination, altered the effects of MPTP upon TH or GFAP immunostaining. Permethrin alone increased striatal GFAP immunopositive neuropil but not when combined with chlorpyrifos treatment. Therefore, combined administration of the two insecticides appeared to protect against an increase in a neuropathological indicator of striatal damage seen with permethrin treatment alone. Differences compared with analysis of entire striatum emphasize the value of varying the topographic focus used to assess nigrostriatal degeneration in studies of insecticides in PD.

APA, Harvard, Vancouver, ISO, and other styles

44

Wu, Shaoxiong, Hongpeng Zhang, Ting Miao, Haiyan Zhu, Lianyuan Wang, and Liang Ge. "Study on Kinetics of GD Hydrolysis in HCl aqueous." E3S Web of Conferences 267 (2021): 02060. http://dx.doi.org/10.1051/e3sconf/202126702060.

Full text

Abstract:

Organophosphate neurotoxic agents like Sarin (GB) and Soman (GD) are lethal to person. Except various kinds of decontaminants, they can be also decomposed in natural environment through nucleophilic reaction, where acidic or alkaline substance was to accelerate their hydrolysis. Most of the papers were about GB hydrolysis. Information on GD hydrolysis was relatively small, especially about kinetics of GD in acidic solution. In view of possible effect of positive ion and negative ion on hydrolysis reaction, a relatively simple composes solution, HCl aqueous solutions, was selected to investigate the factors affecting GD hydrolysis rate. Results showed that GD hydrolysis was accorded with the first-order kinetics equation if pH value was kept constant. Its rate constant was independent of GD initial concentration when the amount of H+ was excess than its requested amount. The apparent hydrolysis rate constant (kobs) in pH of 0.90 was about 0.202 min-1 at 20°C, no matter what initial concentration of GD was. The concentration of H+ was the most important factor affecting its rate. The rate constant (kobs) in HCl aqueous as a function of pH value (0.90~2.80) obeyed an equation in 25°C, that is kobs =0.17×10-0.82×pH. Reaction temperature had an obvious effect on hydrolysis rate of GD. Every 10°C increase in temperature, kobs of GD hydrolysis was improved about 2.5 times. The activation energy value (Ea) of GD hydrolysis in HCl aqueous with a pH value of 0.90 was approximately 64.25 kJ/mol.

APA, Harvard, Vancouver, ISO, and other styles

45

Olson, C. T., R. G. Menton, R. C. Riser, M. C. Matthews, R. R. Stotts, J. R. Romano, I. Koplovitz, B. E. Hackley, and J. B. Johnson. "Efficacies of Atropine/2-PAM and Atropine/HI-6 in Treating Monkeys Intoxicated with Organophosphonate Nerve Agents." International Journal of Toxicology 16, no. 1 (January 1997): 9–20. http://dx.doi.org/10.1080/109158197227314.

Full text

Abstract:

The efficacies of atropine (ATR)/ 2-PAM and ATRl HI-6 in treating male rhesus monkeys injected with the neurotoxic organophosphonate (OP) agents GA, GB, GD, GF, or VX were compared. Experiments were conducted using no more than 8 monkeys per OP and treatment regimen. Doses were selected using a modified up-and-down experimental design, challenging one monkey per day per OP and treatment. Results were used to approximate the median lethal dose (MLD) for groups of treated monkeys or monkeys given only a vehicle following challenge with an OP. Mortality and signs of intoxication with each treatment were statistically compared. Doses of 2-PAM (25.7 mgl kg) or HI-6 (50 mgl kg) and atropine (0.4 mg free base! kg) were given in a single intramuscular (IM) injection 1 min following challenge with an OP. Strong and well-defined relationships between agent dose and 10-h lethality were observed in untreated animals. The 10-h IM OP MLDs for untreated monkeys were estimated to be 80, 43, 8.0, 22, and 7.4 μg/kg for GA, GB, GD, GF, and VX, respectively. No statistical differences w ere found between AT Rl 2-PAM and AT Rl HI-6 treatment efficacies in preventing lethality for any of the OPs. Both oxime combinations appear to provide protection against a 2 × 10-h MLD of GA, GF, or VX; only

APA, Harvard, Vancouver, ISO, and other styles

46

Knoll-Gellida, Anja, Leslie E. Dubrana, Laure M. Bourcier, Théo Mercé, Gaëlle Gruel, Magalie Soares, and Patrick J. Babin. "Hyperactivity and Seizure Induced by Tricresyl Phosphate Are Isomer Specific and Not Linked to Phenyl Valerate-Neuropathy Target Esterase Activity Inhibition in Zebrafish." Toxicological Sciences 180, no. 1 (January 23, 2021): 160–74. http://dx.doi.org/10.1093/toxsci/kfab006.

Full text

Abstract:

Abstract Environmental exposure to tricresyl phosphate (TCP) may lead to severe neurotoxic effects, including organophosphate (OP)-induced delayed neuropathy. TCP has three symmetric isomers, distinguished by the methyl group position on the aromatic ring system. One of these isomers, tri-ortho-cresyl phosphate (ToCP), has been reported for years as a neuropathic OP, targeting neuropathic target esterase (NTE/PNPLA6), but its mode of toxic action had not been fully elucidated. Zebrafish eleuthero-embryo and larva were used to characterize the differential action of the TCP isomers. The symmetric isomers inhibited phenyl valerate (PV)-NTE enzymatic activity in vivo with different IC50, while no effect was observed on acetylcholinesterase activity. Moreover, the locomotor behavior was also affected by tri-para-cresyl phosphate and tri-meta-cresyl phosphate, only ToCP exposure led to locomotor hyperactivity lasting several hours, associated with defects in the postural control system and an impaired phototactic response, as revealed by the visual motor response test. The electric field pulse motor response test demonstrated that a seizure-like, multiple C-bend-spaghetti phenotype may be significantly induced by ToCP only, independently of any inhibition of PV-NTE activity. Eleuthero-embryos exposed to picrotoxin, a known gamma-aminobutyric acid type-A receptor inhibitor, exhibited similar adverse outcomes to ToCP exposure. Thus, our results demonstrated that the TCP mode of toxic action was isomer specific and not initially related to modulation of PV-NTE activity. Furthermore, it was suggested that the molecular events involved were linked to an impairment of the balance between excitation and inhibition in neuronal circuits.

APA, Harvard, Vancouver, ISO, and other styles

47

Piras, Ignazio Stefano, Stefano Gabriele, Laura Altieri, Federica Lombardi, Roberto Sacco, Carla Lintas, Barbara Manzi, et al. "Reevaluation of Serum Arylesterase Activity in Neurodevelopmental Disorders." Antioxidants 10, no. 2 (January 22, 2021): 164. http://dx.doi.org/10.3390/antiox10020164.

Full text

Abstract:

Organophosphate compounds (OPs) interfere with neurodevelopment and are neurotoxic for humans and animals. They are first biotransformed to the more toxic oxon form, and then hydrolyzed to specific metabolites by the enzyme paraoxonase/arylesterase, encoded by the gene PON1 located on human chr. 7q21.3. In autism spectrum disorder (ASD) and in attention-deficit/hyperactivity disorder (ADHD), a correlation between OP exposure and disease onset has been reported. In this case-control study, we aimed to replicate our previous work showing reduced levels of serum PON1 arylesterase activity in Italian and Caucasian-American ASD samples, and to extend our analysis to other neurodevelopmental disorders, namely ADHD and developmental language disorder (DLD), also known as specific language impairment (SLI). The arylesterase activity, measured using standard spectrophotometric methods, is significantly reduced in the ADHD, and not in the ASD sample compared with the controls. Our previous results seemingly stem from spuriously high arylesterase levels in the former control sample. Finally, genotyping SNPs rs705379 and rs662 using TDI-FP, a significant effect of rs705379 alleles on the serum arylesterase activity is observed in all of the subgroups tested, regardless of diagnosis, as well as a lack of association between PON1 gene polymorphisms and ASD/ADHD susceptibility in the Italian population. In summary, the serum arylesterase activity is reduced in children and adolescents with ADHD, and this reduction is not due to the functional PON1 gene variants assessed in this study. Based on previous literature, it may more likely reflect enhanced oxidative stress than specific genetic underpinnings.

APA, Harvard, Vancouver, ISO, and other styles

48

Almami, Ibtesam S., Maha A. Aldubayan, Shatha G. Felemban, Najiah Alyamani, Richard Howden, Alexander J. Robinson, Tom D. Z. Pearson, et al. "Neurite outgrowth inhibitory levels of organophosphates induce tissue transglutaminase activity in differentiating N2a cells: evidence for covalent adduct formation." Archives of Toxicology 94, no. 11 (August 4, 2020): 3861–75. http://dx.doi.org/10.1007/s00204-020-02852-w.

Full text

Abstract:

Abstract Organophosphate compounds (OPs) induce both acute and delayed neurotoxic effects, the latter of which is believed to involve their interaction with proteins other than acetylcholinesterase. However, few OP-binding proteins have been identified that may have a direct role in OP-induced delayed neurotoxicity. Given their ability to disrupt Ca2+ homeostasis, a key aim of the current work was to investigate the effects of sub-lethal neurite outgrowth inhibitory levels of OPs on the Ca2+-dependent enzyme tissue transglutaminase (TG2). At 1–10 µM, the OPs phenyl saligenin phosphate (PSP) and chlorpyrifos oxon (CPO) had no effect cell viability but induced concentration-dependent decreases in neurite outgrowth in differentiating N2a neuroblastoma cells. The activity of TG2 increased in cell lysates of differentiating cells exposed for 24 h to PSP and chlorpyrifos oxon CPO (10 µM), as determined by biotin-cadaverine incorporation assays. Exposure to both OPs (3 and/or 10 µM) also enhanced in situ incorporation of the membrane permeable substrate biotin-X-cadaverine, as indicated by Western blot analysis of treated cell lysates probed with ExtrAvidin peroxidase and fluorescence microscopy of cell monolayers incubated with FITC-streptavidin. Both OPs (10 µM) stimulated the activity of human and mouse recombinant TG2 and covalent labelling of TG2 with dansylamine-labelled PSP was demonstrated by fluorescence imaging following SDS-PAGE. A number of TG2 substrates were tentatively identified by mass spectrometry, including cytoskeletal proteins, chaperones and proteins involved protein synthesis and gene regulation. We propose that the elevated TG2 activity observed is due to the formation of a novel covalent adduct between TG2 and OPs.

APA, Harvard, Vancouver, ISO, and other styles

49

Woreta, Danuta. "Control of cockchafer Melolontha spp. grubs – a review of methods." Folia Forestalia Polonica 57, no. 1 (March 1, 2015): 33–41. http://dx.doi.org/10.1515/ffp-2015-0005.

Full text

Abstract:

Abstract The paper presents a review of information on control measures used to prevent damages due to cockchafer Melolontha spp. grubs in European countries including Poland. There are described the methods used at times when mechanical and chemical treatments were applied as well as those under advanced research. In the past, cockchafer grubs were manually removed from plowed soils. Later on, chemical pest control commenced in plant protection practice, and a range of insecticides were either spotted directly onto plants or applied into planting rows, otherwise an entire planting area was treated. In that case, powder or granular insecticide formulations were mixed with upper soil layers, but liquid insecticides were poured into the soil around seedlings. The active substance of initial plant protection products used in Poland to control cockchafer grubs was lindane (organochlorine neurotoxin), which showed pretty high efficacy. Nevertheless, organochlorine products must have been withdrawn from the market and less damaging to the environment pesticides (organophosphates and carbamates) were recommended for use in forest protection against cockchafer grubs. As a result of progressive restrictions concerning application of chemicals into forest environment, alternate solutions have been sought, e.g. biological methods of cockchafer grub control have been tested. Up to date studies showed insecticidal properties of bacteria, fungi and nematodes. However, even though the knowledge and awareness of practitioners have raised with time, the problem of cockchafer grub populations damaging forest crops has not yet been solved and seems to be more and more difficult to overcome.

APA, Harvard, Vancouver, ISO, and other styles

50

Baldissera, Matheus D., Carine F. Souza, Sharine N. Descovi, Renato Zanella, Osmar D. Prestes, Aleksandro S. da Silva, and Bernardo Baldisserotto. "Organophosphate pesticide trichlorfon induced neurotoxic effects in freshwater silver catfish Rhamdia quelen via disruption of blood-brain barrier: Implications on oxidative status, cell viability and brain neurotransmitters." Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology 218 (April 2019): 8–13. http://dx.doi.org/10.1016/j.cbpc.2018.12.006.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Organophosphate neurotoxics'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles