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Academic Emergency Medicine : Official... Jul 2010Organophosphorus (OP) pesticides exert a tremendous health burden, particularly in the developing world. Limited resources, the severity of intentional OP ingestions,...
OBJECTIVES
Organophosphorus (OP) pesticides exert a tremendous health burden, particularly in the developing world. Limited resources, the severity of intentional OP ingestions, and a paucity of beneficial therapies all contribute to the morbidity and mortality of this broad class of chemicals. A novel theoretical treatment for OP poisoning is the use of an enzyme to degrade the parent OP in the circulation after poisoning. The aims of this study were to determine the pharmacokinetics and efficacy of an OP hydrolase (OpdA) in a rodent model of severe methyl-parathion poisoning.
METHODS
Two animal models were used. First, Wistar rats were administered two different doses of the hydrolase (0.15 and 1.5 mg/kg), and the ex vivo hydrolytic activity of plasma was determined by a fluorometric method. Second, an oral methyl-parathion animal poisoning model was developed to mimic severe human poisoning, and the efficacy of postpoisoning OpdA (as measured by survival to 4 and 24 hours) was determined.
RESULTS
The half-life of OpdA in the Wistar rat was dependent on the dose administered and ranged between 45.0 and 57.9 minutes. The poisoning model of three times the lethal dose to 50% of the population (3 x LD(50)) of methyl-parathion resulted in 88% lethality at 4 and 24 hours. Using a single dose of 0.15 mg/kg OpdA 10 minutes after poisoning resulted in 100% survival at 4 hours (p = 0.001 vs. placebo), but 0% at 24 hours postpoisoning (p = NS vs. placebo).
CONCLUSIONS
The OP hydrolase OpdA exhibits pharmacokinetics suitable for repeated dosing and increases short-term survival after severe methyl-parathion poisoning.
Topics: Animals; Aryldialkylphosphatase; Disease Models, Animal; Half-Life; Lethal Dose 50; Methyl Parathion; Rats; Rats, Wistar
PubMed: 20653588
DOI: 10.1111/j.1553-2712.2010.00798.x -
Academic Emergency Medicine : Official... May 2012Therapies exist for acute organophosphate (OP) exposure but mortality rates remain high (10% to 20%). Currently, treatment focuses on reversing the resultant cholinergic...
BACKGROUND
Therapies exist for acute organophosphate (OP) exposure but mortality rates remain high (10% to 20%). Currently, treatment focuses on reversing the resultant cholinergic excess effects through the use of atropine. Intralipid fat emulsion (IFE) has been used to treat lipophilic drug ingestions and theoretically would be beneficial for some OP agents.
OBJECTIVES
The hypothesis was that IFE would decrease the acute respiratory depressant effects following lethal OP exposure using a lipophilic OP agent (parathion).
METHODS
The authors used a previously validated animal model of OP poisoning with detailed physiologic respiratory recordings. The model consisted of Wistar rats anesthetized but spontaneously breathing 100% oxygen. Airflow, respiratory rate, tidal volume, mean arterial pressure, and pulse rate were digitally recorded for 120 minutes following OP exposure or until respiratory failure. Three study groups included parathion alone (n = 6), parathion and IFE 5 minutes after poisoning (n = 6), and parathion and IFE 20 minutes after poisoning (n = 6). In all groups, parathion was given as a single oral dose of 54 mg/kg (four times the rat oral 50% population lethal dose [LD(50) ]). Three boluses of IFE (15 mg/kg/min) were given over 3 minutes, 20 minutes apart, starting either 5 or 20 minutes after poisoning. Timing of IFE was based on parathion kinetics. In one study group IFE was initiated 5 minutes after poisoning to coincide with initial absorption of parathion. In another study group IFE was given at 20 minutes to coincide with peak intravenous (IV) parathion concentration. Primary outcome was percentage of animals with apnea. Secondary outcome was time to apnea.
RESULTS
Animals exposed to parathion alone demonstrated a steady decline in respiratory rate and tidal volume postexposure, with apnea occurring a mean of 51.6 minutes after poisoning (95% confidence interval [CI] = 35.8 to 53.2 minutes). Animals treated with IFE 5 minutes postexposure demonstrated no difference in mean time to apnea (44.5 minutes vs. 51.6 minutes, p = 0.29) or number of animals with respiratory arrest (100% vs. 100%, p = 1.00). Animals treated with IFE 20 minutes postexposure demonstrated a significantly prolonged mean time to apnea (95.3 minutes vs. 51.6 minutes, p = 0.002), but there was no difference in number of animals with respiratory arrest (100% vs. 66.7%, p = 0.45).
CONCLUSIONS
All animals exposed to 4 × LD(50) of oral parathion demonstrate apnea and respiratory arrest. IFE given immediately after oral parathion does not prolong time to apnea. IFE given 20 minutes after oral exposure to parathion decreases the acute effects of the OP and prolongs the time to apnea.
Topics: Administration, Oral; Animals; Apnea; Disease Models, Animal; Emulsions; Fat Emulsions, Intravenous; Insecticides; Male; Parathion; Phospholipids; Rats; Rats, Wistar; Respiratory Insufficiency; Soybean Oil
PubMed: 22594353
DOI: 10.1111/j.1553-2712.2012.01337.x -
Nanomaterials (Basel, Switzerland) Apr 2022Flexible sensors are highly advantageous for integration in portable and wearable devices. In this work, we propose and validate a simple strategy to achieve whole...
Flexible sensors are highly advantageous for integration in portable and wearable devices. In this work, we propose and validate a simple strategy to achieve whole wafer-size flexible SERS substrate via a one-step metal-assisted chemical etching (MACE). A pre-patterning Si wafer allows for PSi structures to form in tens of microns areas, and thus enables easy detachment of PSi film pieces from bulk Si substrates. The morphology, porosity, and pore size of PS films can be precisely controlled by varying the etchant concentration, which shows obvious effects on film integrity and wettability. The cracks and self-peeling of Psi films can be achieved by the drying conditions after MACE, enabling transfer of Psi films from Si wafer to any substrates, while maintaining their original properties and vertical alignment. After coating with a thin layer of silver (Ag), the rigid and flexible PSi films before and after transfer both show obvious surface-enhanced Raman scattering (SERS) effect. Moreover, flexible PSi films SERS substrates have been demonstrated with high sensitivity (down to 2.6 × 10 g/cm) for detection of methyl parathion (MPT) residues on a curved apple surface. Such a method provides us with quick and high throughput fabrication of nanostructured materials for sensing, catalysis, and electro-optical applications.
PubMed: 35407309
DOI: 10.3390/nano12071191 -
Heliyon Feb 2021This study assessed pesticide usage practices, knowledge and health effects of pesticides through occupational exposure in randomly selected horticultural farmers in...
This study assessed pesticide usage practices, knowledge and health effects of pesticides through occupational exposure in randomly selected horticultural farmers in Imenti North, Imenti South and Buuri Sub-counties in Meru, Kenya, where horticultural crops are grown intensively for export and local consumption. The study was done through use of questionnaire distributed to farmers' households, agricultural extension workers and health care workers. The survey established that various classes of pesticides were used in horticultural crop farming and animal production in all the three sub-counties, with the most frequently used (>60 respondents out of 173) being parathion, diazinon, dimethoate, permethrin, pirimiphos methyl, endrin, deltamethrin, dieldrin, propoxur and endosulfan. It was found that there is a gap between the existing government regulations on pesticide use and safe handling and the implementation of these regulations by dealers, farmers and farm workers in the three sub-counties as some of the pesticides that were being used such as parathion, endrin, dieldrin and carbofuran had been banned by the government. Although most farmers had general information on pesticide usage through various social groups and contact with agricultural extension workers, only 32-43 % of the farmers had received training on pesticide handling and use. Most farmers (65%) had knowledge of safe pesticide handling procedures including reading labels on packages and wearing protective clothing; but many farmers (44% in Buuri, 57% in Imenti South and 60% in Imenti North) did not wear the requisite protective clothing when applying pesticides. The agricultural extension workers (52%) and health care workers (59%) were trained in their work and had at least a certificate level qualification from a tertiary institution. Most agricultural extension workers (95%) and health care workers (71%) had experience of dealing with pesticides and knew how to administer 1 AID against pesticide poisoning, respectively. Farmers (26%) reported experiencing health effects after using pesticides, with most effects being felt after using dimethoate, malathion, carbofuran, carbaryl and heptachlor. There was a statistically significant (p < 0.05) association between various factors (availability of protective clothing, hiring of labourers, farm land size, expenditure on pesticides and expenditure on treatment, respectively) on intoxication from pesticide exposure.
PubMed: 33659728
DOI: 10.1016/j.heliyon.2021.e06118 -
Environment International Dec 2019Pesticide exposure during pregnancy is thought to adversely affect fetal growth, which in turn may impact child growth, but results have been inconsistent across studies...
BACKGROUND
Pesticide exposure during pregnancy is thought to adversely affect fetal growth, which in turn may impact child growth, but results have been inconsistent across studies and few have explored these effects in developing countries.
OBJECTIVES
To quantify urinary concentrations of pesticide biomarkers in early pregnancy (<16 weeks' gestation), and to estimate the association of these concentrations with preterm birth, low birth weight, small for gestational age, and stunting at ~1 and 2 years of age.
METHODS
Eight pesticide biomarkers were quantified in urine collected from 289 pregnant women (aged 18-40 years) participating in a birth cohort study in Bangladesh. Anthropometry measurements were conducted on the index child at birth and approximately 1 and 2 years of age. A directed acyclic graph was used to identify minimal sufficient adjustment sets. Log-binomial regression was used to estimate the relative risk (RR) with 95% confidence intervals (CI).
RESULTS
3,5,6-trichloro-2-pyridinol (TCPY), a metabolite of chlorpyrifos and chlorpyrifos methyl, and 4-nitrophenol, a metabolite of parathion and methyl parathion, were detected in nearly all women with geometric mean (95% CI) values of 3.17 (2.82-3.56) and 18.66 (17.03-20.46) µg/g creatinine, respectively. 3-phenoxybenzoic acid (3-PBA), a non-specific metabolite of several pyrethroids, and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPY), a diazinon metabolite, were detected in 19.8% and 16.1% of women, respectively. The remaining four pesticide biomarkers were detected in <10% of women. Women in the highest quartile of 4-nitrophenol were more than 3 times more likely to deliver preterm than women in the lowest quartile: unadjusted RR (95% CI), 3.57 (1.65, 7.73). Women in the highest quartile of 4-nitrophenol were also at increased risk of having a child born small for gestational age: RR (95% CI) adjusted for household income, maternal education, and maternal total energy and meat intake, 3.81 (1.10, 13.21). Women with detectable concentrations of IMPY were at increased risk of having a child born with low birth weight compared to women with non-detectable concentrations: adjusted RR (95% CI), 2.13 (1.12, 4.08). We observed no association between any of the pesticide biomarkers and stunting at 1 or 2 years of age.
DISCUSSION
Exposure to the insecticides parathion and diazinon during early pregnancy may increase the risk of adverse birth outcomes.
Topics: Adult; Bangladesh; Child, Preschool; Cohort Studies; Female; Growth Disorders; Humans; Infant; Infant, Low Birth Weight; Infant, Newborn; Maternal Exposure; Pesticides; Pregnancy; Pregnancy Outcome; Premature Birth; Rural Population; Young Adult
PubMed: 31675560
DOI: 10.1016/j.envint.2019.105243 -
Turkish Journal of Medical Sciences 2014To evaluate the usefulness of plasma glucose and serum cholinesterase levels as predictors of organophosphate-induced intermediate syndrome.
AIM
To evaluate the usefulness of plasma glucose and serum cholinesterase levels as predictors of organophosphate-induced intermediate syndrome.
MATERIALS AND METHODS
Seventy-one organophosphate poisoning patients who were admitted to our emergency department during a 4-year period were evaluated retrospectively. Four patients were excluded from the study due to a lack of medical records. Categorical variables were analyzed using the chi-square test and nonparametric variables were analyzed using the Mann-Whitney U test.
RESULTS
Thirty-five (52.2%) patients were male and 32(47.8%) were female. Patients had a mean age of 39.4 ± 15.9 years and 70.1% of the patients were married. Oral intake (68.7%) was the most common method of intoxication, and attempted suicide (67.2%) was the most common cause. The most common organophosphates were methamidophos (20.8%), dichlorvos (19.4%), parathion (7.5%), and methyl parathion (7.5%). Fifty-seven (85%) patients were treated in the emergency observation unit and 10 (15%) patients were admitted to the intensive care unit. Eleven (16%) patients developed intermediate syndrome and had significantly lower levels of serum cholinesterase (P < 0.01) and higher blood glucose levels (P = 0.037).
CONCLUSION
Initial serum cholinesterase and glucose levels measured in the emergency department may be a useful marker in predicting organophosphate-induced intermediate syndrome.
Topics: Adult; Blood Glucose; Cholinesterase Reactivators; Cholinesterases; Emergency Service, Hospital; Female; Humans; Male; Muscle Weakness; Organophosphate Poisoning; Oximes; Patient Admission; Respiratory Paralysis; Retrospective Studies; Suicide, Attempted; Turkey; Vomiting
PubMed: 25536737
DOI: 10.3906/sag-1211-31 -
BMC Genomics Nov 2012The genomes of three major mosquito vectors of human diseases, Anopheles gambiae, Aedes aegypti, and Culex pipiens quinquefasciatus, have been previously sequenced. C....
BACKGROUND
The genomes of three major mosquito vectors of human diseases, Anopheles gambiae, Aedes aegypti, and Culex pipiens quinquefasciatus, have been previously sequenced. C. p. quinquefasciatus has the largest number of predicted protein-coding genes, which partially results from the expansion of three detoxification gene families: cytochrome P450 monooxygenases (P450), glutathione S-transferases (GST), and carboxyl/cholinesterases (CCE). However, unlike An. gambiae and Ae. aegypti, which have large amounts of gene expression data, C. p. quinquefasciatus has limited transcriptomic resources. Knowledge of complete gene expression information is very important for the exploration of the functions of genes involved in specific biological processes. In the present study, the three detoxification gene families of C. p. quinquefasciatus were analyzed for phylogenetic classification and compared with those of three other dipteran insects. Gene expression during various developmental stages and the differential expression responsible for parathion resistance were profiled using the digital gene expression (DGE) technique.
RESULTS
A total of 302 detoxification genes were found in C. p. quinquefasciatus, including 71 CCE, 196 P450, and 35 cytosolic GST genes. Compared with three other dipteran species, gene expansion in Culex mainly occurred in the CCE and P450 families, where the genes of α-esterases, juvenile hormone esterases, and CYP325 of the CYP4 subfamily showed the most pronounced expansion on the genome. For the five DGE libraries, 3.5-3.8 million raw tags were generated and mapped to 13314 reference genes. Among 302 detoxification genes, 225 (75%) were detected for expression in at least one DGE library. One fourth of the CCE and P450 genes were detected uniquely in one stage, indicating potential developmentally regulated expression. A total of 1511 genes showed different expression levels between a parathion-resistant and a susceptible strain. Fifteen detoxification genes, including 2 CCEs, 6 GSTs, and 7 P450s, were expressed at higher levels in the resistant strain.
CONCLUSIONS
The results of the present study provide new insights into the functions and evolution of three detoxification gene families in mosquitoes and comprehensive transcriptomic resources for C. p. quinquefasciatus, which will facilitate the elucidation of molecular mechanisms underlying the different biological characteristics of the three major mosquito vectors.
Topics: Animals; Cholinesterases; Chromosome Mapping; Culex; Cytochrome P-450 Enzyme System; Esterases; Gene Expression Profiling; Gene Expression Regulation; Genome; Glutathione Transferase; Inactivation, Metabolic; Phylogeny
PubMed: 23140097
DOI: 10.1186/1471-2164-13-609 -
Journal of Hazardous Materials Oct 2015Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial...
Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial strain being capable of degrading O,O-dialkyl phosphorothioate and O,O-dialkyl phosphate insecticides, designated as G1, was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis suggested that strain G1 belongs to the genus Stenotrophomonas. At an initial concentration of 50 mg/L, strain G1 degraded 100% of methyl parathion, methyl paraoxon, diazinon, and phoxim, 95% of parathion, 63% of chlorpyrifos, 38% of profenofos, and 34% of triazophos in 24 h. Orthogonal experiments showed that the optimum conditions were an inoculum volume of 20% (v/v), a substrate concentration of 50 mg/L, and an incubation temperature in 40 °C. p-Nitrophenol was detected as the metabolite of methyl parathion, for which intracellular methyl parathion hydrolase was responsible. Strain G1 can efficiently degrade eight organophosphorus pesticides (OPs) and is a very excellent candidate for applications in OP pollution remediation.
Topics: Biodegradation, Environmental; Organophosphorus Compounds; Pesticides; RNA, Ribosomal, 16S; Sewage; Stenotrophomonas; Water Pollutants, Chemical
PubMed: 25938642
DOI: 10.1016/j.jhazmat.2015.04.052 -
Beilstein Journal of Nanotechnology 2022Organophosphate-based pesticides (e.g., parathion (PT)) have toxic effects on human health through their residues. Therefore, cost-effective and rapid detection...
Organophosphate-based pesticides (e.g., parathion (PT)) have toxic effects on human health through their residues. Therefore, cost-effective and rapid detection strategies need to be developed to ensure the consuming food is free of any organophosphate-residue. This work proposed the fabrication of a robust, nonenzymatic electrochemical-sensing electrode modified with electrochemically reduced graphene oxide (ERGO) to detect PT residues in environmental samples (e.g., soil, water) as well as in vegetables and cereals. The ERGO sensor shows a significantly affected electrocatalytic reduction peak at -0.58 V (vs Ag/AgCl) for rapid quantification of PT due to the amplified electroactive surface area of the modified electrode. At optimized experimental conditions, square-wave voltammetric analysis exhibits higher sensitivity (50.5 μA·μM·cm), excellent selectivity, excellent stability (≈180 days), good reproducibility, and repeatability for interference-free detection of PT residues in actual samples. This electrochemical nanosensor is suitable for point-of-care detection of PT in a wide dynamic range of 3 × 10-11 × 10 M with a lower detection limit of 10.9 pM. The performance of the nanosensor was validated by adding PT to natural samples and comparing the data via absorption spectroscopy. PT detection results encourage the design of easy-to-use nanosensor-based analytical tools for rapidly monitoring other environmental samples.
PubMed: 35957670
DOI: 10.3762/bjnano.13.65 -
Scientific Reports Oct 2020This study introduces an applicable colorimetric sensor array for the detection of pesticides in the vapor phase. The array consisted of six metal nanoparticles spotted...
This study introduces an applicable colorimetric sensor array for the detection of pesticides in the vapor phase. The array consisted of six metal nanoparticles spotted on the piece of filter paper. 3D-origami pattern was used for the fabrication of a paper-based sensor to decrease the effect of the nanoparticles leaching after exposure to analytes. Exposure to pesticide aerosols caused changes in the color of the array due to the aggregation of nanoparticles. These changes provided selective responses to thion pesticides such as malathion, parathion, chlorpyrifos, and diazinon. The sensing assay could also differentiate between aliphatic and aromatic thions and discriminate amine-containing compounds from the other studied analytes. These finding results are clearly confirmed by both visual detection and multivariate statistical methods. The proposed sensor was successfully developed for the quantitative measurement of pesticide aerosols at a very low concentration. The limit of detection of this method determined for malathion, parathion, chlorpyrifos and diazinon were 58.0, 103.0, 81.0 and 117.0, respectively. Moreover, the array could be employed to simultaneously analyze four studied pesticides. The statistcal results confirmed that the method has high performance for concurrent detection of thions as a major air pollutant without the interference of other species.
PubMed: 33057151
DOI: 10.1038/s41598-020-74509-8