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Sample records for acute organophosphate op

  1. Organophosphate Poisoning and Subsequent Acute Kidney Injury Risk

    PubMed Central

    Lee, Feng-You; Chen, Wei-Kung; Lin, Cheng-Li; Lai, Ching-Yuan; Wu, Yung-Shun; Lin, I-Ching; Kao, Chia-Hung

    2015-01-01

    Abstract Small numbers of the papers have studied the association between organophosphate (OP) poisoning and the subsequent acute kidney injury (AKI). Therefore, we used the National Health Insurance Research Database (NHIRD) to study whether patients with OP poisoning are associated with a higher risk to have subsequent AKI. The retrospective cohort study comprised patients aged ≥20 years with OP poisoning and hospitalized diagnosis during 2000–2011 (N = 8924). Each OP poisoning patient was frequency-matched to 4 control patients based on age, sex, index year, and comorbidities of diabetes, hypertension, hyperlipidemia, chronic obstructive pulmonary disease, coronary artery disease, and stroke (N = 35,696). We conducted Cox proportional hazard regression analysis to estimate the effects of OP poisoning on AKI risk. The overall incidence of AKI was higher in the patients with OP poisoning than in the controls (4.85 vs 3.47/1000 person-years). After adjustment for age, sex, comorbidity, and interaction terms, patients with OP poisoning were associated with a 6.17-fold higher risk of AKI compared with the comparison cohort. Patients with highly severe OP poisoning were associated with a substantially increased risk of AKI. The study found OP poisoning is associated with increased risk of subsequent AKI. Future studies are encouraged to evaluate whether long-term effects exist and the best guideline to prevent the continuously impaired renal function. PMID:26632728

  2. Organophosphate Poisoning and Subsequent Acute Kidney Injury Risk: A Nationwide Population-Based Cohort Study.

    PubMed

    Lee, Feng-You; Chen, Wei-Kung; Lin, Cheng-Li; Lai, Ching-Yuan; Wu, Yung-Shun; Lin, I-Ching; Kao, Chia-Hung

    2015-11-01

    Small numbers of the papers have studied the association between organophosphate (OP) poisoning and the subsequent acute kidney injury (AKI). Therefore, we used the National Health Insurance Research Database (NHIRD) to study whether patients with OP poisoning are associated with a higher risk to have subsequent AKI.The retrospective cohort study comprised patients aged ≥20 years with OP poisoning and hospitalized diagnosis during 2000-2011 (N = 8924). Each OP poisoning patient was frequency-matched to 4 control patients based on age, sex, index year, and comorbidities of diabetes, hypertension, hyperlipidemia, chronic obstructive pulmonary disease, coronary artery disease, and stroke (N = 35,696). We conducted Cox proportional hazard regression analysis to estimate the effects of OP poisoning on AKI risk.The overall incidence of AKI was higher in the patients with OP poisoning than in the controls (4.85 vs 3.47/1000 person-years). After adjustment for age, sex, comorbidity, and interaction terms, patients with OP poisoning were associated with a 6.17-fold higher risk of AKI compared with the comparison cohort. Patients with highly severe OP poisoning were associated with a substantially increased risk of AKI.The study found OP poisoning is associated with increased risk of subsequent AKI. Future studies are encouraged to evaluate whether long-term effects exist and the best guideline to prevent the continuously impaired renal function.

  3. Increased Risk of Dementia in Patients With Acute Organophosphate and Carbamate Poisoning

    PubMed Central

    Lin, Jiun-Nong; Lin, Cheng-Li; Lin, Ming-Chia; Lai, Chung-Hsu; Lin, Hsi-Hsun; Yang, Chih-Hui; Kao, Chia-Hung

    2015-01-01

    Abstract Organophosphate (OP) and carbamate (CM) are the most commonly used pesticides against insects. Little is known regarding the relationship between dementia and acute OP and CM poisoning. A nationwide population-based cohort study was conducted from the National Health Insurance Research Database in Taiwan. The incidence and relative risk of dementia were assessed in patients hospitalized for acute OP and CM poisoning from 2000 to 2011. The comparison cohort was matched with the poisoned cohort at a 4:1 ratio based on age, sex, and the year of hospitalization. During the follow-up period, the incidence of dementia was 29.4 per 10,000 person-years in the poisoned group, and represented a 1.98-fold increased risk of dementia compared with the control cohort (95% confidence interval, 1.59–2.47). This study provides evidence on the association between dementia and acute OP and CM poisoning. Regular follow-up of poisoned patients for dementia is suggested. PMID:26200627

  4. Respiratory failure of acute organophosphate and carbamate poisoning.

    PubMed

    Tsao, T C; Juang, Y C; Lan, R S; Shieh, W B; Lee, C H

    1990-09-01

    Respiratory failure (RF) developed in 43 (40.2 percent) of 107 patients with acute organophosphate or carbamate poisoning; 22 (51.2 percent) died. The 64 patients who did not develop RF survived. All cases of RF developed within 96 hours after poisoning: within 24 hours in 35 patients (acute onset) and between 24 and 96 hours in eight patients (subacute onset). Severity of poisoning was the primary determinating factor for RF. Cardiovascular collapse and pneumonia were also associated with RF. In 19 patients with cardiovascular collapse, 17 had acute onset of RF and two had subacute onset. In 28 patients with pneumonia, 17 developed acute onset of RF and eight developed subacute onset. No organophosphorus compound caused RF more frequently than another. The duration of ventilator support for subacute RF was significantly longer than for acute RF (287 +/- 186 vs 115 +/- 103 hours, p = 0.02). The use of pralidoxime did not reduce the incidence of RF. We found that severity of poisoning, cardiovascular collapse, and pneumonia were the predisposing factors to RF. The golden time for treatment of acute organophosphate or carbamate poisoning was the initial 96 hours. No RF occurred after this time. Aggressive treatment and prevention of the above three factors will reduce the incidence of RF, or in other words, reduce the mortality.

  5. Transient and reversible parkinsonism after acute organophosphate poisoning.

    PubMed

    Arima, Hajime; Sobue, Kazuya; So, MinHye; Morishima, Tetsuro; Ando, Hirkoshi; Katsuya, Hirotada

    2003-01-01

    Parkinsonism is a rare complication in patients with organophosphate poisoning. To date there have been two cases of transient parkinsonism after acute and severe cholinergic crisis, both of which were successfully treated using amantadine, an anti-parkinsonism drug. We report on an 81-year-old woman who was admitted for the treatment of acute severe organophosphate poisoning. Although acute cholinergic crisis was treated successfully with large doses of atropine and 2-pyridine aldoxime methiodide (PAM), extrapyramidal manifestations were noticed on hospital day 6. The neurological symptoms worsened, and the diagnosis of parkinsonism was made by a neurologist on hospital day 9. Immediately, biperiden (5mg), an anti-parkinsonism drug, was administered intravenously, and her symptoms markedly improved. From the following day, biperiden (5 mg/day) was given intramuscularly for eight days. Subsequently, neurological symptoms did not relapse, and no drugs were required. Our patient is the third case of parkinsonism developing after an acute severe cholinergic crisis and the first case successfully treated with biperiden. Patients should be carefully observed for the presence of neurological signs in this kind of poisoning. If present, an anti-parkinsonism drug should be considered.

  6. Increased Risk of Dementia in Patients With Acute Organophosphate and Carbamate Poisoning: A Nationwide Population-Based Cohort Study.

    PubMed

    Lin, Jiun-Nong; Lin, Cheng-Li; Lin, Ming-Chia; Lai, Chung-Hsu; Lin, Hsi-Hsun; Yang, Chih-Hui; Kao, Chia-Hung

    2015-07-01

    Organophosphate (OP) and carbamate (CM) are the most commonly used pesticides against insects. Little is known regarding the relationship between dementia and acute OP and CM poisoning. A nationwide population-based cohort study was conducted from the National Health Insurance Research Database in Taiwan. The incidence and relative risk of dementia were assessed in patients hospitalized for acute OP and CM poisoning from 2000 to 2011. The comparison cohort was matched with the poisoned cohort at a 4:1 ratio based on age, sex, and the year of hospitalization. During the follow-up period, the incidence of dementia was 29.4 per 10,000 person-years in the poisoned group, and represented a 1.98-fold increased risk of dementia compared with the control cohort (95% confidence interval, 1.59-2.47). This study provides evidence on the association between dementia and acute OP and CM poisoning. Regular follow-up of poisoned patients for dementia is suggested.

  7. Mechanism for the acute effects of organophosphate pesticides on the adult 5-HT system

    PubMed Central

    Judge, Sarah J.; Savy, Claire Y.; Campbell, Matthew; Dodds, Rebecca; Gomes, Larissa Kruger; Laws, Grace; Watson, Anna; Blain, Peter G.; Morris, Christopher M.; Gartside, Sarah E.

    2016-01-01

    The neurotransmitter serotonin (5-HT) is involved in mood disorder aetiology and it has been reported that (organophosphate) OP exposure affects 5-HT turnover. The aim of this study was to elucidate the mechanism underlying OP effects on the adult 5-HT system. First, acute in vivo administration of the OP diazinon (0, 1.3, 13 or 39 mg/kg i.p.) to male Hooded Lister rats inhibited the activity of the cholinergic enzyme acetylcholinesterase in blood and in the hippocampus, dorsal raphe nucleus (DRN), striatum and prefrontal cortex. Diazinon-induced cholinesterase inhibition was greatest in the DRN, the brain's major source of 5-HT neurones. Second, acute in vivo diazinon exposure (0 or 39 mg/kg i.p.) increased the basal firing rate of DRN neurones measured ex vivo in brain slices. The excitatory responses of DRN neurones to α1-adrenoceptor or AMPA/kainate receptor activation were not affected by in vivo diazinon exposure but the inhibitory response to 5-HT was attenuated, indicating 5-HT1A autoreceptor down-regulation. Finally, direct application of the diazinon metabolite diazinon oxon to naive rat brain slices increased the firing rate of DRN 5-HT neurones, as did chlorpyrifos-oxon, indicating the effect was not unique to diazinon. The oxon-induced augmentation of firing was blocked by the nicotinic acetylcholine receptor antagonist mecamylamine and the AMPA/kainate glutamate receptor antagonist DNQX. Together these data indicate that 1) acute OP exposure inhibits DRN cholinesterase, leading to acetylcholine accumulation, 2) the acetylcholine activates nicotinic receptors on 5-HT neurones and also on glutamatergic neurones, thus releasing glutamate and activating 5-HT neuronal AMPA/kainate receptors 3) the increase in 5-HT neuronal activity, and resulting 5-HT release, may lead to 5-HT1A autoreceptor down-regulation. This mechanism may be involved in the reported increase in risk of developing anxiety and depression following occupational OP exposure. PMID

  8. Unequal Efficacy of Pyridinium Oximes in Acute Organophosphate Poisoning

    PubMed Central

    Antonijevic, Biljana; Stojiljkovic, Milos P.

    2007-01-01

    The use of organophosphorus pesticides results in toxicity risk to non-target organisms. Organophosphorus compounds share a common mode of action, exerting their toxic effects primarily via acetylcholinesterase (AChE) inhibition. Consequently, acetylcholine accumulates in the synaptic clefts of muscles and nerves, leading to overstimulation of cholinergic receptors. Acute cholinergic crisis immediately follows exposure to organophosphate and includes signs and symptoms resulting from hyperstimulation of central and peripheral muscarinic and nicotinic receptors. The current view of the treatment of organophosphate poisoning includes three strategies, i.e. the use of an anticholinergic drug (e.g., atropine), cholinesterase-reactivating agents (e.g., oximes) and anticonvulsant drugs (e.g., benzodiazepines). Oximes, as a part of antidotal therapy, ensure the recovery of phosphylated enzymes via a process denoted as reactivation of inhibited AChE. However, both experimental results and clinical findings have demonstrated that different oximes are not equally effective against poisonings caused by structurally different organophosphorus compounds. Therefore, antidotal characteristics of conventionally used oximes can be evaluated regarding how close the certain substance is to the theoretical concept of the universal oxime. Pralidoxime (PAM-2), trimedoxime (TMB-4), obidoxime (LüH-6), HI-6 and HLö-7 have all been demonstrated to be very effective in experimental poisonings with sarin and VX. TMB-4 and LüH-6 may reactivate tabun-inhibited AChE, whereas HI-6 possesses the ability to reactivate the soman-inhibited enzyme. An oxime HLö-7 seems to be an efficient reactivator of AChE inhibited by any of the four organophosphorus warfare agents. According to the available literature, the oximes LüH-6 and TMB-4, although relatively toxic, are the most potent to induce reactivation of AChE inhibited by the majority of organophosphorus pesticides. Since there are no reports of

  9. An electrophysiological study of the intermediate syndrome of organophosphate poisoning.

    PubMed

    Lorenzoni, Paulo José; Gasparetto, Juliano; Kay, Cláudia Suemi Kamoi; Scola, Rosana Herminia; Werneck, Lineu César

    2010-09-01

    Acute organophosphate (OP) poisoning is commonly seen in emergency medicine. Neurologists must be alert to detect neuromuscular transmission failure and other neurological complications that follow OP poisoning. We report a 37-year-old male with acute OP poisoning to emphasize the electrophysiological abnormalities during the intermediate syndrome (IMS). Motor nerve conduction studies revealed that a single nerve stimulation evoked a repetitive compound muscle action potential, whereas repetitive nerve stimulation resulted in a combination of a decrement-increment pattern and a repetitive fade response. Thus, electrophysiological studies can be used to monitor patients with IMS, and these test results correlate well with clinical findings in acute OP poisoning. PMID:20483619

  10. Organophosphate poisoning complicated by a tachyarrhythmia and acute respiratory distress syndrome in a child.

    PubMed

    Nel, L; Hatherill, M; Davies, J; Andronikou, S; Stirling, J; Reynolds, L; Argent, A

    2002-10-01

    A 9-year-old child presented with documented organophosphate insecticide poisoning. His course was initially complicated by a tachyarrhythmia with QT-interval prolongation that responded promptly to intravenous magnesium. However, following partial recovery, he developed progressive acute respiratory distress syndrome characterized by irreversible fibrosis and obliteration of the lung parenchyma. PMID:12354276

  11. Cardiac manifestations of acute carbamate and organophosphate poisoning.

    PubMed Central

    Saadeh, A. M.; Farsakh, N. A.; al-Ali, M. K.

    1997-01-01

    OBJECTIVE: To study the frequency, extent, and pathogenesis of the cardiac complications accompanying organophosphate and carbamate poisoning. DESIGN: Retrospective study. SETTING: A medical intensive care unit (MICU) of a general hospital. SUBJECTS: 46 adult patients admitted over a five year period with a diagnosis of organophosphate or carbamate poisoning. RESULTS: Cardiac complications developed in 31 patients (67%). These were: non-cardiogenic pulmonary oedema, 20 (43%); cardiac arrhythmias, 11 (24%); electrocardiographic abnormalities including prolonged Q-Tc interval, 31 (67%); ST-T changes, 19 (41%); and conduction defects, 4 (9%). Sinus tachycardia occurred in 16 patients (35%) and sinus bradycardia in 13 (28%). Hypertension developed in 10 patients (22%) and hypotension in eight (17%). Eight patients (17%) needed respiratory support because of respiratory depression. Although more than two thirds of the patients (67%) had a prolonged Q-Tc interval, none had polymorphic ventricular tachycardia of the torsade de pointes type. Two patients died from ventricular fibrillation, an in hospital mortality of 4%. CONCLUSIONS: Cardiac complications often accompany poisoning with these compounds, particularly during the first few hours. Hypoxaemia, acidosis, and electrolyte derangements are major predisposing factors. Intensive supportive treatment in intensive or coronary care facilities with administration of atropine in adequate doses early in the course of the illness will reduce the mortality. PMID:9196418

  12. Metabolic complications of organophosphate and carbamate poisoning.

    PubMed

    Saadeh, A M

    2001-07-01

    The clinical manifestations of acute organophosphate (OP) and carbamate poisoning have already been well described. Most of these reports were on the cardiac, neurologic, respiratory and other clinical complications of these compounds. However, very little attention has been given to the metabolic aspects of this problem, particularly those accompanying carbamate poisoning. This paper describes the metabolic complications seen in 84 adult patients after acute poisoning with these compounds.

  13. Mass Spectrometric Analyses of Organophosphate Insecticide Oxon Protein Adducts

    PubMed Central

    Thompson, Charles M.; Prins, John M.; George, Kathleen M.

    2010-01-01

    Objective Organophosphate (OP) insecticides continue to be used to control insect pests. Acute and chronic exposures to OP insecticides have been documented to cause adverse health effects, but few OP-adducted proteins have been correlated with these illnesses at the molecular level. Our aim was to review the literature covering the current state of the art in mass spectrometry (MS) used to identify OP protein biomarkers. Data sources and extraction We identified general and specific research reports related to OP insecticides, OP toxicity, OP structure, and protein MS by searching PubMed and Chemical Abstracts for articles published before December 2008. Data synthesis A number of OP-based insecticides share common structural elements that result in predictable OP–protein adducts. The resultant OP–protein adducts show an increase in molecular mass that can be identified by MS and correlated with the OP agent. Customized OP-containing probes have also been used to tag and identify protein targets that can be identified by MS. Conclusions MS is a useful and emerging tool for the identification of proteins that are modified by activated organophosphate insecticides. MS can characterize the structure of the OP adduct and also the specific amino acid residue that forms the key bond with the OP. Each protein that is modified in a unique way by an OP represents a unique molecular biomarker that with further research can lead to new correlations with exposure. PMID:20056576

  14. Investigation on acute toxicity and behavioral changes in Channa punctatus (Bloch) due to organophosphate pesticide profenofos.

    PubMed

    Pandey, Atindra Kumar; Nagpure, N S; Trivedi, Sunil P; Kumar, Ravindra; Kushwaha, Basdeo; Lakra, Wazir S

    2011-10-01

    Acute toxicity of an organophosphate pesticide profenofos (O-4-bromo-2- chlorophenyl-O-ethyl S-propyl phosphorothioate) to freshwater fish, Channa punctatus (Bloch), was studied in a static bioassay. Estimated 96-hour LC(50) of profenofos was found to be 2.68 μgL(-1). On the basis of the obtained LC(50) values for 96-hour exposure intervals, profenofos can be rated as highly toxic to C. punctatus. Fish exposed to profenofos showed hyper excitability, discoloration, erratic swimming, and secretion of excess amounts of mucus on the body and gills with eventual exhaustion and death. PMID:21770742

  15. To identify morbidity and mortality predictors in acute organophosphate poisoning

    PubMed Central

    Muley, Arti; Shah, Chaitri; Lakhani, Jitendra; Bapna, Mani; Mehta, Jigar

    2014-01-01

    Background: Organophosphorus poisoning remains an important cause of morbidity and mortality, but no definite parameters have been identified as predictors of outcome. Prediction of morbidity at presentation might help in decision making in places of limited resources like rural settings in developing countries. Materials and Methods: A total of 76 cases were included in this retrospective cohort study. Logged relative risk of requirement of mechanical ventilation and hospital stay >7 days was measured in patients with serum acetylcholinesterase (s. acetylcholinesterase) <1000 versus >1000, presenting in <2 h versus ≥ 2 h after exposure, with Glasgow Coma Scale (GCS) ≤12 versus >12 and in patients with SpO2 <85% versus ≥85% at room air at presentation. Results: S. acetylcholinesterase <1000, time elapsed after ingestion to presentation ≥ 2 h and SpO2 (at room air) at presentation <85% were found to have positive association with requirement of ventilation. GCS ≤ 12 had a significant association with both requirement of ventilation and hospital stay >7 days. Conclusion: S. acetylcholinesterase, SpO2 at room air, GCS, and duration of exposure at presentation can be used to identify the requirement of special care in acute organophosphorus poisoning. This can aid in decision making regarding admission to intensive care unit and referral in the places with limited resources. PMID:24914258

  16. Paradox findings may challenge orthodox reasoning in acute organophosphate poisoning.

    PubMed

    Eyer, Peter; Worek, Franz; Thiermann, Horst; Eddleston, Michael

    2010-09-01

    It is generally accepted that inhibition of acetylcholinesterase (AChE) is the most important acute toxic action of organophosphorus compounds, leading to accumulation of acetylcholine followed by a dysfunction of cholinergic signaling. However, the degree of AChE inhibition is not uniformly correlated with cholinergic dysfunction, probably because the excess of essential AChE varies among tissues. Moreover, the cholinergic system shows remarkable plasticity, allowing modulations to compensate for dysfunctions of the canonical pathway. A prominent example is the living (-/-) AChE knockout mouse. Clinical experience indicates that precipitous inhibition of AChE leads to more severe poisoning than more protracted yet finally complete inhibition. The former situation is seen in parathion, the latter in oxydemeton methyl poisoning. At first glance, this dichotomy is surprising since parathion is a pro-poison and has to be activated to the oxon, while the latter is still the ultimate inhibitor. Also oxime therapy in organophosphorus poisoning apparently gives perplexing results: Oximes are usually able to reactivate diethylphosphorylated AChE, but the efficiency may be occasionally markedly smaller than expected from kinetic data. Dimethylphosphorylated AChE is in general less amenable to oxime therapy, which largely fails in some cases of dimethoate poisoning where aging was much faster than expected from a dimethylphosphorylated enzyme. Similarly, poisoning by profenofos, an O,S-dialkyl phosphate, leads to a rapidly aged enzyme. Most surprisingly, these patients were usually well on admission, yet their erythrocyte AChE was completely inhibited. Analysis of the kinetic constants of the most important reaction pathways, determination of the reactant concentrations in vivo and comparison with computer simulations may reveal unexpected toxic reactions. Pertinent examples will be presented and the potentially underlying phenomena discussed. PMID:19883634

  17. Spatiotemporal pattern of neuronal injury induced by DFP in rats: A model for delayed neuronal cell death following acute OP intoxication

    SciTech Connect

    Li Yonggang; Lein, Pamela J.; Liu Cuimei; Bruun, Donald A.; Tewolde, Teclemichael; Ford, Gregory; Ford, Byron D.

    2011-06-15

    Organophosphate (OP) neurotoxins cause acute cholinergic toxicity and seizures resulting in delayed brain damage and persistent neurological symptoms. Testing novel strategies for protecting against delayed effects of acute OP intoxication has been hampered by the lack of appropriate animal models. In this study, we characterize the spatiotemporal pattern of cellular injury after acute intoxication with the OP diisopropylfluorophosphate (DFP). Adult male Sprague-Dawley rats received pyridostigmine (0.1 mg/kg, im) and atropine methylnitrate (20 mg/kg, im) prior to DFP (9 mg/kg, ip) administration. All DFP-treated animals exhibited moderate to severe seizures within minutes after DFP injection but survived up to 72 h. AChE activity was significantly depressed in the cortex, hippocampus, subcortical brain tissue and cerebellum at 1 h post-DFP injection and this inhibition persisted for up to 72 h. Analysis of neuronal injury by Fluoro-Jade B (FJB) labeling revealed delayed neuronal cell death in the hippocampus, cortex, amygdala and thalamus, but not the cerebellum, starting at 4 h and persisting until 72 h after DFP treatment, although temporal profiles varied between brain regions. At 24 h post-DFP injection, the pattern of FJB labeling corresponded to TUNEL staining in most brain regions, and FJB-positive cells displayed reduced NeuN immunoreactivity but were not immunopositive for astrocytic (GFAP), oligodendroglial (O4) or macrophage/microglial (ED1) markers, demonstrating that DFP causes a region-specific delayed neuronal injury mediated in part by apoptosis. These findings indicate the feasibility of this model for testing neuroprotective strategies, and provide insight regarding therapeutic windows for effective pharmacological intervention following acute OP intoxication. - Research Highlights: > DFP induced neuronal FJB labeling starting at 4-8 h after treatment > The pattern of DFP-induced FJB labeling closely corresponded to TUNEL staining > FJB

  18. Bioconcentration and Acute Intoxication of Brazilian Freshwater Fishes by the Methyl Parathion Organophosphate Pesticide

    PubMed Central

    Bosco de Salles, João; Matos Lopes, Renato; de Salles, Cristiane M. C.; Cassano, Vicente P. F.; de Oliveira, Manildo Marcião; Cunha Bastos, Vera L. F.; Bastos, Jayme Cunha

    2015-01-01

    Three species of freshwater Brazilian fishes (pacu, Piaractus mesopotamicus; piavussu, Leporinus macrocephalus, and curimbatá, Prochilodus lineatus) were exposed to an acute dose of 5 ppm methyl parathion organophosphate pesticide. Three to five individuals per species were exposed, one at a time, to 40 liters tap water spiked with Folidol 600. Pesticide concentrations and cholinesterase (ChE) activities were evaluated in serum, liver, brain, heart, and muscle. The bioconcentration of methyl parathion was similar for all studied fishes. Brain tissue showed the highest pesticide concentration, reaching 80 ppm after exposure for 30 min to methyl parathion. Three to 5 hours of 5 ppm methyl parathion exposure provoked the death of all P. lineatus at 92% brain AChE inhibition, whereas fish from the other two species survived for up to 78 hours with less than 80% brain AChE inhibition. Our results indicate that acute toxic effects of methyl parathion to fish are correlated with brain AChE sensitivity to methyl paraoxon. PMID:26339593

  19. Bioconcentration and Acute Intoxication of Brazilian Freshwater Fishes by the Methyl Parathion Organophosphate Pesticide.

    PubMed

    de Salles, João Bosco; Lopes, Renato Matos; de Salles, Cristiane M C; Cassano, Vicente P F; de Oliveira, Manildo Marcião; Bastos, Vera L F Cunha; Bastos, Jayme Cunha

    2015-01-01

    Three species of freshwater Brazilian fishes (pacu, Piaractus mesopotamicus; piavussu, Leporinus macrocephalus, and curimbatá, Prochilodus lineatus) were exposed to an acute dose of 5 ppm methyl parathion organophosphate pesticide. Three to five individuals per species were exposed, one at a time, to 40 liters tap water spiked with Folidol 600. Pesticide concentrations and cholinesterase (ChE) activities were evaluated in serum, liver, brain, heart, and muscle. The bioconcentration of methyl parathion was similar for all studied fishes. Brain tissue showed the highest pesticide concentration, reaching 80 ppm after exposure for 30 min to methyl parathion. Three to 5 hours of 5 ppm methyl parathion exposure provoked the death of all P. lineatus at 92% brain AChE inhibition, whereas fish from the other two species survived for up to 78 hours with less than 80% brain AChE inhibition. Our results indicate that acute toxic effects of methyl parathion to fish are correlated with brain AChE sensitivity to methyl paraoxon. PMID:26339593

  20. Acute poisoning in a child following topical treatment of head lice (pediculosis capitis) with an organophosphate pesticide.

    PubMed

    Hamad, Muddathir H; Adeel, Ahmed Awad; Alhaboob, Ali Abdu N; Ashri, Ahmed M; Salih, Mustafa A

    2016-01-01

    This is a case report of acute organophosphate poisoning in a child treated with topical application of Diazinon-60 (WHO Class II toxicity) for head lice (pediculosis capitis). The patient presented with neurological symptoms and signs. After emergency respiratory and circulatory resuscitation the patient underwent dermal decontamination and was treated with atropine, high flow oxygen and pralidoxime. Scanning electron micrographs of scalp hair specimens revealed both viable and empty head lice nits (lice eggs that attach to the hair shaft). The patient was hospitalized for seven days and discharged after full recovery. The case highlights the importance of raising the awareness of health workers and the community about the danger of misusing pesticides for the treatment of head lice. PMID:27651556

  1. Acute poisoning in a child following topical treatment of head lice (pediculosis capitis) with an organophosphate pesticide

    PubMed Central

    Adeel, Ahmed Awad; Alhaboob, Ali Abdu N; Ashri, Ahmed M; Salih, Mustafa A

    2016-01-01

    This is a case report of acute organophosphate poisoning in a child treated with topical application of Diazinon-60 (WHO Class II toxicity) for head lice (pediculosis capitis). The patient presented with neurological symptoms and signs. After emergency respiratory and circulatory resuscitation the patient underwent dermal decontamination and was treated with atropine, high flow oxygen and pralidoxime. Scanning electron micrographs of scalp hair specimens revealed both viable and empty head lice nits (lice eggs that attach to the hair shaft). The patient was hospitalized for seven days and discharged after full recovery. The case highlights the importance of raising the awareness of health workers and the community about the danger of misusing pesticides for the treatment of head lice. PMID:27651556

  2. Organophosphate and carbamate poisoning.

    PubMed

    King, Andrew M; Aaron, Cynthia K

    2015-02-01

    Organophosphates (OPs) and carbamates have a wide variety of applications, most commonly as pesticides used to eradicate agricultural pests or control populations of disease-carrying vectors. Some OP and carbamates have therapeutic indications such as physostigmine. Certain organophosphorus compounds, known as nerve agents, have been employed in chemical warfare and terrorism incidents. Both classes inhibit acetylcholinesterase (AChE) enzymes, leading to excess acetylcholine accumulation at nerve terminals. In the setting of toxicity from either agent class, clinical syndromes result from excessive nicotinic and muscarinic neurostimulation. The toxic effects from OPs and carbamates differ with respect to reversibility, subacute, and chronic effects. Decontamination, meticulous supportive care, aggressive antimuscarinic therapy, seizure control, and administration of oximes are cornerstones of management.

  3. Noninvasive Biomonitoring Approaches to Determine Dosimetry and Risk Following Acute Chemical Exposure: Analysis of Lead or Organophosphate Insecticide in Saliva

    SciTech Connect

    Timchalk, Chuck; Poet, Torka S.; Kousba, Ahmed A.; Campbell, James A.; Lin, Yuehe

    2004-04-01

    There is a need to develop approaches for assessing risk associated with acute exposures to a broad-range of chemical agents and to rapidly determine the potential implications to human health. Non-invasive biomonitoring approaches are being developed using reliable portable analytical systems to quantitate dosimetry utilizing readily obtainable body fluids, such as saliva. Saliva has been used to evaluate a broad range of biomarkers, drugs, and environmental contaminants including heavy metals and pesticides. To advance the application of non-invasive biomonitoring a microfluidic/ electrochemical device has also been developed for the analysis of lead (Pb), using square wave anodic stripping voltammetry. The system demonstrates a linear response over a broad concentration range (1 2000 ppb) and is capable of quantitating saliva Pb in rats orally administered acute doses of Pb-acetate. Appropriate pharmacokinetic analyses have been used to quantitate systemic dosimetry based on determination of saliva Pb concentrations. In addition, saliva has recently been used to quantitate dosimetry following exposure to the organophosphate insecticide chlorpyrifos in a rodent model system by measuring the major metabolite, trichloropyridinol, and saliva cholinesterase inhibition following acute exposures. These results suggest that technology developed for non-invasive biomonitoring can provide a sensitive, and portable analytical tool capable of assessing exposure and risk in real-time. By coupling these non-invasive technologies with pharmacokinetic modeling it is feasible to rapidly quantitate acute exposure to a broad range of chemical agents. In summary, it is envisioned that once fully developed, these monitoring and modeling approaches will be useful for accessing acute exposure and health risk.

  4. Coronary artery bypass grafting in a patient with organophosphate poisoning.

    PubMed

    Pieris, Rajeeva R; Fernando, Ravindra

    2015-01-01

    A 43-year-old male, with no previous history of mental illness, was diagnosed with coronary heart disease, after which he became acutely depressed and attempted suicide by ingesting an organophosphate pesticide. He was admitted to an intensive care unit and treated with pralidoxime, atropine, and oxygen. His coronary occlusion pattern required early coronary artery bypass grafting (CABG) surgery. His family, apprehensive of a repeat suicidal attempt, requested surgery be performed as soon as possible. He recovered well from the OP poisoning and was mentally fit to express informed consent 2 weeks after admission. Seventeen days after poisoning, he underwent coronary artery bypass grafting and recovered uneventfully. Six years later, he remains in excellent health. We report this case because to the best of our knowledge there is no literature regarding CABG performed soon after organophosphate poisoning.

  5. Acute toxicity of organophosphate insecticide, dichlorvos in relation to selected water hardness for the freshwater zooplankters.

    PubMed

    Gupta, Ashok Kumar; Verma, Girraj Prasad; Jain, Khyali Lal

    2008-11-01

    Toxicity of organophosphate insecticide, i.e. dichlorvos has been investigated in relation to selected water hardness for the freshwater zooplankters such as Moina, Daphnia, cyclops and nauplii. Results revealed that dichlorvos was highly toxic to the tested zooplankters, as the LC50 values are noticed in ppb. Trend of sensitivity for different zooplankters to dichlorvos was recorded as Moina < Daphnia < nauplii < cyclops. The LC50 were found to change significantly with the change in water hardness. The zooplankters were more susceptible to dichlorvos at water hardness of 275 mgl(-1) as compared to water hardness of 540 mgl(-1) as revealed from low LC50 values. The range of safe dischargeable concentrations (1.063-1.137ppb) were too low as compared to harmless or safe concentrations (43.895-89.194 ppb) for the zooplankters at both the hardness.

  6. The effect of stress on the acute neurotoxicity of the organophosphate insecticide chlorpyrifos

    SciTech Connect

    Hancock, Sandra; Ehrich, Marion; Hinckley, Jonathan; Pung, Thitiya; Jortner, Bernard S. . E-mail: bjortner@vt.edu

    2007-03-15

    A study was conducted to determine if multiple exposures to several stress paradigms might affect the anticholinesterase effect of subsequently administered organophosphate insecticide chlorpyrifos. Male Sprague-Dawley rats were subject to daily periods of restraint, swimming, a combination of the two, or neither of the two (controls) (n = 8/group) for 5 days per week over a six-week period. The most profound stress, as measured by reduced body weight gain and elevated levels of plasma corticosterone, was swimming. On day 39 of the study, shortly after the daily stress episode, one half of the rats in each group was dosed with 60 mg/kg chlorpyrifos subcutaneously. This had no effect on subsequent levels of plasma corticosterone. There were no stress-related differences in the degree of chlorpyrifos-induced inhibition of brain acetylcholinesterase in animals sacrificed on day 43.

  7. Acute toxicity of organophosphate insecticide, dichlorvos in relation to selected water hardness for the freshwater zooplankters.

    PubMed

    Gupta, Ashok Kumar; Verma, Girraj Prasad; Jain, Khyali Lal

    2008-11-01

    Toxicity of organophosphate insecticide, i.e. dichlorvos has been investigated in relation to selected water hardness for the freshwater zooplankters such as Moina, Daphnia, cyclops and nauplii. Results revealed that dichlorvos was highly toxic to the tested zooplankters, as the LC50 values are noticed in ppb. Trend of sensitivity for different zooplankters to dichlorvos was recorded as Moina < Daphnia < nauplii < cyclops. The LC50 were found to change significantly with the change in water hardness. The zooplankters were more susceptible to dichlorvos at water hardness of 275 mgl(-1) as compared to water hardness of 540 mgl(-1) as revealed from low LC50 values. The range of safe dischargeable concentrations (1.063-1.137ppb) were too low as compared to harmless or safe concentrations (43.895-89.194 ppb) for the zooplankters at both the hardness. PMID:19297975

  8. Organophosphate and carbamate pesticide poisoning: the usefulness of a computerized clinical information system.

    PubMed

    Lerman, Y; Hirshberg, A; Shteger, Z

    1984-01-01

    Organophosphate (OP) and carbamate poisoning are still a worldwide health problem causing numerous fatalities in humans. Physicians who have no clinical toxicological experience with these compounds may have difficulties in promptly identifying the etiologic agent and managing the acute phase of the poisoning. We describe the potential use of a computerized medical information system that includes clinical data on 236 cases of OP and carbamate poisoning, and may improve the management of such poisoning. The methods of constructing the system, the first results of using the system, and the medical institutions that can benefit from such systems are discussed.

  9. Use of OpdA, an organophosphorus (OP) hydrolase, prevents lethality in an African green monkey model of acute OP poisoning.

    PubMed

    Jackson, Colin J; Carville, Angela; Ward, Jeanine; Mansfield, Keith; Ollis, David L; Khurana, Tejvir; Bird, Steven B

    2014-03-20

    Organophosphorus (OP) pesticides are a diverse class of acetylcholinesterase (AChE) inhibitors that are responsible for tremendous morbidity and mortality worldwide, killing approximately 300,000 people annually. Enzymatic hydrolysis of OPs is a potential therapy for acute poisoning. OpdA, an OP hydrolase isolated from Agrobacterium radiobacter, has been shown to decrease lethality in rodent models of OP poisoning. This study investigated the effects of OpdA on AChE activity, plasma concentrations of OP, and signs of toxicity after administration of dichlorvos to nonhuman primates. A dose of 75 mg/kg dichlorvos given orally caused apnea within 10 min with a progressive decrease in heart rate. Blood AChE activity decreased to zero within 10 min. Respirations and AChE activity did not recover. The mean dichlorvos concentration rose to a peak of 0.66 μg/ml. Treated monkeys received 1.2mg/kg OpdA iv immediately after poisoning with dichlorvos. In Opda-treated animals, heart and respiratory rates were unchanged from baseline over a 240-minute observation period. AChE activity slowly declined, but remained above 25% of baseline for the entire duration. Dichlorvos concentrations reached a mean peak of 0.19 μg/ml at 40 min after poisoning and decreased to a mean of 0.05 μg/ml at 240 min. These results show that OpdA hydrolyzes dichlorvos in an African green monkey model of lethal poisoning, delays AChE inhibition, and prevents lethality.

  10. Acute large-dose exposure to organophosphates in patients with and without diabetes mellitus: analysis of mortality rate and new-onset diabetes mellitus

    PubMed Central

    2014-01-01

    Background We investigated the mortality rates of patients with and without diabetes mellitus after acute large-dose exposure to organophosphate insecticides. All patients without diabetes mellitus were traced to examine the long-term risk of new-onset diabetes mellitus. Previous reports indicated that organophosphate exposure might increase the risk of new-onset diabetes mellitus. Methods We analyzed the records of 118 patients referred to Chang Gung Memorial Hospital for management of intentional organophosphate poisoning between 2000 and 2011. Patients were stratified by diabetes mellitus status. Demographic, clinical, laboratory and mortality data were analyzed. Results Most patients were middle aged (53.45 ± 16.20 years) and male (65.3%) and were referred to our hospital after a relatively short amount of time had elapsed since poisoning (median 3.0 hours). 18 (15.2%) of 118 patients died, including 15 (13.8%) of 109 patients without diabetes mellitus and 3 (33.3%) of 9 with diabetes mellitus. There was no significant difference in mortality between these groups (P = 0.117). In a multivariate Cox regression model, hypotension (P = 0.000), respiratory failure (P = 0.042), coma (P = 0.023), and corrected QT interval prolongation (P = 0.002) were significant risk factors for mortality. Conversely, diabetes mellitus status was not a significant variable in this model. At routine outpatient follow up a median of 1.25 months post exposure, random blood glucose measurements gave no evidence of new-onset diabetes in patients without pre-existing diabetes. Conclusions Diabetes mellitus status might not increase mortality risk following acute large-dose exposure to organophosphates, and the risk of new-onset diabetes mellitus also might be minimal in the short term. Larger prospective studies with formal testing for diabetes at later times post-exposure are required. PMID:24597539

  11. Effects of acute organophosphate poisoning on pituitary target gland hormones at admission, discharge and three months after poisoning: A hospital based pilot study

    PubMed Central

    Dutta, Pinaki; Kamath, Shruthi S.; Bhalla, Ashish; Shah, V.N.; Srinivasan, Anand; Gupta, Prakamya; Singh, Surjit

    2015-01-01

    Background: Organophosphate compound (OPC) poisoning is common in the developing countries such as India. The acute and later effects of OPC poisoning on pituitary and target gland hormones is largely unknown. Materials and Methods: This prospective study was conducted at Postgraduate Institute of Medical Education and Research between January 2012 and March 2013. Fourteen patients (8 males, age 18-50 years) with acute OPC poisoning were included in the study based on the history and clinical features, documented decreased in plasma cholinesterase activity or presence of the OPC in gastric lavage/blood samples. The hormonal parameters were done at baseline, at the time of discharge and at three months of follow-up. Results: A total of 14 patients out of 46 with the mean age of 30.1 ± 10.3 years were finally eligible for the study. Hormonal alterations at admission were similar to sick euhormonal syndrome. Overall 7 of them had nine hormonal deficits at three months of follow up, 4 having sub normal basal cortisol level and two each had low testosterone and growth hormone and only one had thyroxine deficiency. Conclusion: Acute organophosphate poisoning results in endocrine dysfunction akin to sick euhormonal syndrome. However, in a small subset of patients, varying level of hormonal insufficiency may occur either at admission or later. These observations need re-validation in a larger group of patients with specific OPC. PMID:25593838

  12. Multi-organ Dysfunction Syndrome with Dual Organophosphate Pesticides Poisoning.

    PubMed

    Mishra, Ajay; Pandya, Himanshu V; Dave, Nikhil; Mehta, Manan

    2013-09-01

    Organophosphate (OP) pesticide self-poisoning is common in developing countries. Poisoning with dual OP compounds is rare. Multi-organ dysfunction after OP poisoning has a high mortality rate. We report the case of a 27-year-old man who developed multi-organ dysfunction syndrome with fatal outcome after intentional ingestion of 50:50 mixture of two OP compounds, dichlorvos and profenofos.

  13. Multi-organ Dysfunction Syndrome with Dual Organophosphate Pesticides Poisoning

    PubMed Central

    Mishra, Ajay; Pandya, Himanshu V.; Dave, Nikhil; Mehta, Manan

    2013-01-01

    Organophosphate (OP) pesticide self-poisoning is common in developing countries. Poisoning with dual OP compounds is rare. Multi-organ dysfunction after OP poisoning has a high mortality rate. We report the case of a 27-year-old man who developed multi-organ dysfunction syndrome with fatal outcome after intentional ingestion of 50:50 mixture of two OP compounds, dichlorvos and profenofos. PMID:24403738

  14. ORGANOPHOSPHATE PESTICIDE EXPOSURES - WHERE ARE THE HIGH RISK CHILDREN?

    EPA Science Inventory

    Methods to identify children at high-risk for organophosphate (OP) pesticide exposure are difficult to develop because biological markers reflect only recent "snapshots" of exposure due to the short half-life of OP compounds (generally about 24 hours). We conducted a series of p...

  15. ORGANOPHOSPHATE PESTICIDE DEGRADATION PATHWAYS DURING DRINKING WATER TREATMENT

    EPA Science Inventory

    Free chlorine has been found to react with organophosphate (OP) pesticides resulting in the more toxic oxon products. We will discuss OP pesticide degradation pathways and modeling in the presence of chlorine and chloramines, as well as present a relationship between structure a...

  16. Clinical features of organophosphate poisoning: A review of different classification systems and approaches

    PubMed Central

    Peter, John Victor; Sudarsan, Thomas Isiah; Moran, John L.

    2014-01-01

    Purpose: The typical toxidrome in organophosphate (OP) poisoning comprises of the Salivation, Lacrimation, Urination, Defecation, Gastric cramps, Emesis (SLUDGE) symptoms. However, several other manifestations are described. We review the spectrum of symptoms and signs in OP poisoning as well as the different approaches to clinical features in these patients. Materials and Methods: Articles were obtained by electronic search of PubMed® between 1966 and April 2014 using the search terms organophosphorus compounds or phosphoric acid esters AND poison or poisoning AND manifestations. Results: Of the 5026 articles on OP poisoning, 2584 articles pertained to human poisoning; 452 articles focusing on clinical manifestations in human OP poisoning were retrieved for detailed evaluation. In addition to the traditional approach of symptoms and signs of OP poisoning as peripheral (muscarinic, nicotinic) and central nervous system receptor stimulation, symptoms were alternatively approached using a time-based classification. In this, symptom onset was categorized as acute (within 24-h), delayed (24-h to 2-week) or late (beyond 2-week). Although most symptoms occur with minutes or hours following acute exposure, delayed onset symptoms occurring after a period of minimal or mild symptoms, may impact treatment and timing of the discharge following acute exposure. Symptoms and signs were also viewed as an organ specific as cardiovascular, respiratory or neurological manifestations. An organ specific approach enables focused management of individual organ dysfunction that may vary with different OP compounds. Conclusions: Different approaches to the symptoms and signs in OP poisoning may better our understanding of the underlying mechanism that in turn may assist with the management of acutely poisoned patients. PMID:25425841

  17. Efficacy of an organophosphate mixture against an organophosphate-resistant strain of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of an organophosphate (OP) mixture acaricide, Ravap®, was evaluated as a whole-body spray treatment applied at 0.15 and 0.3% active ingredient (AI) to cattle infested with all parasitic stages of a highly OP-resistant strain of Rhipicephalus (Boophilus) microplus (Canestrini). Laborator...

  18. Paradoxical effect of salbutamol in a model of acute organophosphates intoxication in guinea pigs: role of substance P release.

    PubMed

    Chávez, Jaime; Segura, Patricia; Vargas, Mario H; Arreola, José Luis; Flores-Soto, Edgar; Montaño, Luis M

    2007-04-01

    Organophosphates induce bronchoobstruction in guinea pigs, and salbutamol only transiently reverses this effect, suggesting that it triggers additional obstructive mechanisms. To further explore this phenomenon, in vivo (barometric plethysmography) and in vitro (organ baths, including ACh and substance P concentration measurement by HPLC and immunoassay, respectively; intracellular Ca2+) measurement in single myocytes) experiments were performed. In in vivo experiments, parathion caused a progressive bronchoobstruction until a plateau was reached. Administration of salbutamol during this plateau decreased bronchoobstruction up to 22% in the first 5 min, but thereafter airway obstruction rose again as to reach the same intensity as before salbutamol. Aminophylline caused a sustained decrement (71%) of the parathion-induced bronchoobstruction. In in vitro studies, paraoxon produced a sustained contraction of tracheal rings, which was fully blocked by atropine but not by TTX, omega-conotoxin (CTX), or epithelium removal. During the paraoxon-induced contraction, salbutamol caused a temporary relaxation of approximately 50%, followed by a partial recontraction. This paradoxical recontraction was avoided by the M2- or neurokinin-1 (NK1)-receptor antagonists (methoctramine or AF-DX 116, and L-732138, respectively), accompanied by a long-lasting relaxation. Forskolin caused full relaxation of the paraoxon response. Substance P and, to a lesser extent, ACh released from tracheal rings during 60-min incubation with paraoxon or physostigmine, respectively, were significantly increased when salbutamol was administered in the second half of this period. In myocytes, paraoxon did not produce any change in the intracellular Ca2+ basal levels. Our results suggested that: 1) organophosphates caused smooth muscle contraction by accumulation of ACh released through a TTX- and CTX-resistant mechanism; 2) during such contraction, salbutamol relaxation is functionally antagonized by the

  19. Organophosphate pesticide exposure and neurodegeneration.

    PubMed

    Sánchez-Santed, Fernando; Colomina, Maria Teresa; Herrero Hernández, Elena

    2016-01-01

    Organophosphate pesticides (OPs) are used extensively throughout the world. The main sources of contamination for humans are dietary ingestion and occupational exposures. The major concerns related to OP exposure are delayed effects following high level exposures as well as the impact of low level exposures during the lifespan which are suggested to be a risk factor for nervous system chronic diseases. Both high and low level exposures may have a particularly high impact in population subgroups such as aged or genetically vulnerable populations. Apart from the principle action of OPs which involves inhibition of the acetylcholinesterase (AChE) enzyme, several molecular targets, such as hormones; neurotransmitters; neurotrophic factors; enzymes related to the metabolism of beta amyloid protein as well as inflammatory changes have been identified for OP compounds. Here we review the main neurological and/or cognitive deficits described and the experimental and epidemiological relationships found between pesticide exposure and Alzheimer's, Parkinson's, and Amyotrophic Lateral Sclerosis (ALS) diseases. This report also focuses on possible individual differences making groups resilient or vulnerable to these toxicants. A critical discussion of the evidence obtained from experimental models and possible sources of bias in epidemiological studies is included. In particular this review aims to discuss common targets and pathways identified which may underlie the functional deficits associated with both pesticide exposure and neurodegeneration. PMID:26687930

  20. INCREASED SUSCEPTIBILITY OF THE SPONTANEOUSLY HYPERTENSIVE RAT TO CHLORPYRIFOS, AN ORGANOPHOSPHATE PESTICIDE.

    EPA Science Inventory

    Hypertension and hypothermia are common symptoms in rats exposed to chlorpyrifos (CHP), an organophosphate (OP)-based pesticide. CHP inhibits acetylcholinesterase (AChE) activity resulting in central and peripheral stimulation of cholinergic pathways involved in blood pressure ...

  1. Midazolam as an anticonvulsant antidote for organophosphate intoxication− A pharmacotherapeutic appraisal

    PubMed Central

    Reddy, Sandesh D.; Reddy, Doodipala Samba

    2015-01-01

    SUMMARY Objective This review summarizes the therapeutic potential of midazolam as an anticonvulsant antidote for organophosphate (OP) intoxication. Methods Benzodiazepines are widely used for acute seizures and status epilepticus (SE), a neurological emergency of persistent seizures that can lead to severe neuronal damage or death. Midazolam is a benzodiazepine hypnotic with a rapid onset and short duration of action. Results Midazolam is considered the new drug of choice for persistent acute seizures and SE, including those caused by neurotoxic OPs and nerve agents. Midazolam is a positive allosteric modulator of synaptic GABA-A receptors in the brain. It potentiates GABAergic inhibition and thereby controls hyperexcitability and seizures. Midazolam is administered intravenously or intramuscularly to control acute seizures and SE. Due to its favorable pharmacokinetic features, midazolam is being considered as a replacement anticonvulsant for diazepam in the antidote kit for nerve agents. Clinical studies such as the recent RAMPART trial have confirmed the anticonvulsant efficacy of midazolam in SE in prehospital settings. Significance In experimental models, midazolam is effective when given at the onset of seizures caused by nerve agents. However, benzodiazepines are less effective at terminating seizures when given 30 min or later after OP exposure or seizure onset likely because of internalization or down-regulation of synaptic, but not extrasynaptic, GABA-A receptors, which can lead to diminished potency and seizure recurrence. PMID:26032507

  2. Survival pattern in patients with acute organophosphate poisoning on mechanical ventilation: A retrospective intensive care unit-based study in a tertiary care teaching hospital

    PubMed Central

    Ahmed, Syed M; Das, Bikramjit; Nadeem, Abu; Samal, Rajiv K

    2014-01-01

    Background and Aims: Organophosphorus (OP) compound poisoning is one of the most common poisonings in India. The aim of the study was to study the outcomes and predictors of mortality in patients with acute OP poisoning requiring mechanical ventilation. Methods: A retrospective study was conducted in the intensive care unit and 117 patients were included. Diagnosis was performed from the history taken either from the patient or from the patient's relatives. Demographic data, month of the year, mode of poisoning, common age group, duration of mechanical ventilation, time of starting pralidoxime (PAM), and mortality were recorded. Chi square test, Pearson correlation test, and multivariate binary logistic regression analysis was used. Data are presented as mean ± SD. Results: 91.86% (79/86) of cases were suicidal and remaining cases were accidental. Duration of mechanical ventilation varied from less than 48 hours to more than 7 days. Mortality rate was 33.3%, 7.2%, and 100% in those who required mechanical ventilation for more than 7 days, 5 to 7 days, and 2 to 4 days, respectively. Lag time was less than 6 hrs in 13 patients and all of them survived. 17.1% and 28.1% patients died in whom PAM was started 6 to 12 hrs and 13 to 24 hrs after poisoning, respectively. There was statistically significant positive correlation between lag time of starting of PAM with duration of mechanical ventilation and total dose of PAM (P < 0.0001). None of the predictors age, lag time, severity of poisoning, and duration of ventilation were independent predictors of death. Overall mortality rate was 18.6%. Conclusion: Mortality from OP compound poisoning is directly proportionate to the severity of poisoning, delay in starting PAM, and duration of mechanical ventilation. Death is not dependent on a single factor, rather contributory to these factors working simultaneously. PMID:24700893

  3. Organophosphate pesticides exposure among farmworkers: pathways and risk of adverse health effects.

    PubMed

    Suratman, Suratman; Edwards, John William; Babina, Kateryna

    2015-01-01

    Organophosphate (OP) compounds are the most widely used pesticides with more than 100 OP compounds in use around the world. The high-intensity use of OP pesticides contributes to morbidity and mortality in farmworkers and their families through acute or chronic pesticides-related illnesses. Many factors contributing to adverse health effects have been investigated by researchers to determine pathways of OP-pesticide exposure among farmers in developed and developing countries. Factors like wind/agricultural pesticide drift, mixing and spraying pesticides, use of personal protective equipment (PPE), knowledge, perceptions, washing hands, taking a shower, wearing contaminated clothes, eating, drinking, smoking, and hot weather are common in both groups of countries. Factors including low socioeconomic status areas, workplace conditions, duration of exposure, pesticide safety training, frequency of applying pesticides, spraying against the wind, and reuse of pesticide containers for storage are specific contributors in developing countries, whereas housing conditions, social contextual factors, and mechanical equipment were specific pathways in developed countries. This paper compares existing research in environmental and behavioural exposure modifying factors and biological monitoring between developing and developed countries. The main objective of this review is to explore the current depth of understanding of exposure pathways and factors increasing the risk of exposure potentially leading to adverse health effects specific to each group of countries.

  4. Pharmacological blockade of the calcium plateau provides neuroprotection following organophosphate paraoxon induced status epilepticus in rats.

    PubMed

    Deshpande, Laxmikant S; Blair, Robert E; Huang, Beverly A; Phillips, Kristin F; DeLorenzo, Robert J

    2016-01-01

    Organophosphate (OP) compounds which include nerve agents and pesticides are considered chemical threat agents. Currently approved antidotes are crucial in limiting OP mediated acute mortality. However, survivors of lethal OP exposure exhibit delayed neuronal injury and chronic behavioral morbidities. In this study, we investigated neuroprotective capabilities of dantrolene and carisbamate in a rat survival model of paraoxon (POX) induced status epilepticus (SE). Significant elevations in hippocampal calcium levels were observed 48-h post POX SE survival, and treatment with dantrolene (10mg/kg, i.m.) and carisbamate (90mg/kg, i.m.) lowered these protracted calcium elevations. POX SE induced delayed neuronal injury as characterized by Fluoro Jade C labeling was observed in critical brain areas including the dentate gyrus, parietal cortex, amygdala, and thalamus. Dantrolene and carisbamate treatment provided significant neuroprotection against delayed neuronal damage in these brain regions when administered one-hour after POX-SE. These results indicate that dantrolene or carisbamate could be effective adjuvant therapies to the existing countermeasures to reduce neuronal injury and behavioral morbidities post OP SE survival. PMID:27224207

  5. MICROCHIP ENZYMATIC ASSAY OF ORGANOPHOSPHATE NERVE AGENTS. (R830900)

    EPA Science Inventory

    An on-chip enzymatic assay for screening organophosphate (OP) nerve agents, based on a pre-column reaction of organophosphorus hydrolase (OPH), electrophoretic separation of the phosphonic acid products, and their contactless-conductivity detection, is described. Factors affec...

  6. ORGANOPHOSPHATE PESTICIDE DEGRADATION UNDER DRINKING WATER TREATMENT CONDITIONS

    EPA Science Inventory

    Chlorpyrifos (CP) was used as a model compound to develop experimental methods and prototype modeling tools to forecast the fate of organophosphate (OP) pesticides under drinking water treatment conditions. CP was found to rapidly oxidize to chlorpyrifos oxon (CPO) in the presen...

  7. Intensive care management of organophosphate insecticide poisoning

    PubMed Central

    Sungur, Murat; Güven, Muhammed

    2001-01-01

    Introduction Organophosphate (OP) insecticides inhibit both cholinesterase and pseudo-cholinesterase activities. The inhibition of acetylcholinesterase causes accumulation of acetylcholine at synapses, and overstimulation of neurotransmission occurs as a result of this accumulation. The mortality rate of OP poisoning is high. Early diagnosis and appropriate treatment is often life saving. Treatment of OP poisoning consists of intravenous atropine and oximes. The clinical course of OP poisoning may be quite severe and may need intensive care management. We report our experience with the intensive care management of serious OP insecticide poisonings. Methods A retrospective study was performed on the patients with OP poisoning followed at our medical intensive care unit. Forty-seven patients were included. Diagnosis was performed from the history taken either from the patient or from the patient's relatives about the agent involved in the exposure. Diagnosis could not be confirmed with serum and red blood cell anticholinesterase levels because these are not performed at our institution. Intravenous atropine and pralidoxime was administered as soon as possible. Pralidoxime could not be given to 16 patients: 2 patients did not receive pralidoxime because they were late admissions and 14 did not receive pralidoxime because the Ministry of Health office was out of stock. Other measures for the treatment were gastric lavage and administration of activated charcoal via nasogastric tube, and cleansing the patient's body with soap and water. The patients were intubated and mechanically ventilated if the patients had respiratory failure, a depressed level of consciousness, which causes an inability to protect the airway, and hemodynamic instability. Mechanical ventilation was performed as synchronized intermittent mandatory ventilation + pressure support mode, either as volume or pressure control. Positive end expiratory pressure was titrated to keep SaO2 above 94% with 40

  8. A comprehensive review on experimental and clinical findings in intermediate syndrome caused by organophosphate poisoning

    SciTech Connect

    Abdollahi, Mohammad Karami-Mohajeri, Somayyeh

    2012-02-01

    Acute organophosphate (OP) intoxication is important because of its high morbidity and mortality and occurrence of muscular paralysis associated by inhibition of acetylcholinesterase (AChE) activity at the neuromuscular junction. Cholinergic crisis, intermediate syndrome (IMS), and OP-induced delayed neuropathy (OPIDN) are the evidences that can be observed in OP intoxication. The main cause of morbidity due to OP poisoning is IMS that occurs 24–96 h after poisoning. Mechanisms underlying the IMS are not fully known. Although the electrophysiological aspects of delayed neuropathy are best characterized, the IMS remain very little studied. The aim of this study was to revisit current knowledge related to OP and the IMS. For this purpose, a systematic review without date limitation was performed. A total of 599 relevant articles were found and reviewed. Data were categorized according to experimental and clinical studies. Occurrences of persistent AChE inhibition, electromyography changes, muscle cell injury, and oxidative stress are the most important pieces of evidence for involvement of IMS in OP toxicity. Delayed AChE inhibition, muscle necrosis, down regulation or desensitization of postsynaptic ACh receptors, failure of postsynaptic ACh release, and oxidative stress-related myopathy are involved in IMS. Toxicokinetic factors, such as a high lipid-solubility, duration of AChE inhibition and metabolite excretion, evolution of alterations on repetitive nerve stimulation (RNS), type and frequency of muscle lesions can estimate the probability of the IMS. Plasma AChE of less than 200 units is a predictor and the 30 Hz RNS decremental response could be a useful marker for the IMS.

  9. DETERMINING ACTIVE OXIDANT SPECIES REACTING WITH ORGANOPHOSPHATE PESTICIDES IN CHLORINATED DRINKING WATER

    EPA Science Inventory

    Chlorpyrifos (CP) is an organophosphate (OP) pesticide that was used as a model compound to investigate the transformation of OP pesticides at low pH and in the presence of bromide and natural organic matter (NOM) under drinking water treatment conditions. Raman spectroscopy was...

  10. Gold-Nanoparticle-Based Colorimetric Sensor Array for Discrimination of Organophosphate Pesticides.

    PubMed

    Fahimi-Kashani, Nafiseh; Hormozi-Nezhad, M Reza

    2016-08-16

    There is a growing interest in developing high-performance sensors monitoring organophosphate pesticides, primarily due to their broad usage and harmful effects on mammals. In the present study, a colorimetric sensor array consisting of citrate-capped 13 nm gold nanoparticles (AuNPs) has been proposed for the detection and discrimination of several organophosphate pesticides (OPs). The aggregation-induced spectral changes of AuNPs upon OP addition has been analyzed with pattern recognition techniques, including hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA). In addition, the proposed sensor array has the capability to identify individual OPs or mixtures of them in real samples. PMID:27412472

  11. Central nervous system function and organophosphate insecticide use among pesticide applicators in the Agricultural Health Study

    PubMed Central

    Starks, Sarah E; Gerr, Fred; Kamel, Freya; Lynch, Charles F; Jones, Michael P; Alavanja, Michael C; Sandler, Dale P; Hoppin, Jane A

    2011-01-01

    Acute organophosphate (OP) pesticide exposure is associated with adverse central nervous system (CNS) outcomes, however, little is known about the neurotoxicity of chronic exposures that do not result in acute poisoning. To examine associations between long-term pesticide use and CNS function, neurobehavioral (NB) tests were administered to licensed pesticide applicators enrolled in the Agricultural Health Study (AHS) in Iowa and North Carolina. Between 2006 and 2008, 701 male participants completed nine NB tests to assess memory, motor speed and coordination, sustained attention, verbal learning and visual scanning and processing. Data on ever-use and lifetime days of use of 16 OP pesticides were obtained from AHS interviews conducted before testing between 1993 and 2007 and during the NB visit. The mean age of participants was 61 years (SD = 12). Associations between pesticide use and NB test performance were estimated with linear regression controlling for age and outcome-specific covariates. NB test performance was associated with lifetime days of use of some pesticides. Ethoprop was significantly associated with reduced performance on a test of motor speed and visual scanning. Malathion was significantly associated with poor performance on a test of visual scanning and processing. Conversely, we observed significantly better test performance for five OP pesticides. Specifically, chlorpyrifos, coumaphos, parathion, phorate, and tetrachlorvinphos were associated with better verbal learning and memory; coumaphos was associated with better performance on a test of motor speed and visual scanning; and parathion was associated with better performance on a test of sustained attention. Several associations varied by state. Overall, our results do not provide strong evidence that long-term OP pesticide use is associated with adverse CNS-associated NB test performance among this older sample of pesticide applicators. Potential reasons for these mostly null associations

  12. Organophosphate poisoning in the developed world - a single centre experience from here to the millennium.

    PubMed

    Hrabetz, Heidi; Thiermann, Horst; Felgenhauer, Norbert; Zilker, Thomas; Haller, Bernhard; Nährig, Jörg; Saugel, Bernd; Eyer, Florian

    2013-12-01

    Organophosphate (OP) poisoning is still associated with high morbidity and mortality rates, both in resource-poor settings and in well-developed countries. Despite numerous publications dealing with this particular poison, detailed clinical data on more severe overdoses with these agents are relatively sparsely reported. A retrospective study was consequently conducted on 33 patients with OP poisoning admitted to our intensive care unit (ICU) to provide additional data on clinical features. We included moderate to severe poisonings between 2000 and 2012 who required admission to ICU. Patients ingested dimethyl-OPs in 19 cases, diethyl-OPs in 8 cases and otherwise classified OPs in 6 cases. Death (5/33) occurred rather late and only one of these fatalities died during on-going cholinergic crisis. Of the survivors (28/33), 71% recovered fully while 29% showed predominantly neurological disabilities before being transferred to neurologic rehabilitation. Aspiration pneumonia predominated in 27/33 patients and one patient died in refractory acute respiratory distress syndrome (ARDS). The intermediate syndrome occurred twice and cardiopulmonary resuscitation had to be performed in 6/33 patients. Fatalities showed a higher Poison-severity-score, APACHE-II-score and SOFA-score on admission compared with survivors and they showed significantly longer QTc-time in the ECG, lower systolic blood pressure and heart rate, a lower pH and a lower base excess on admission. Patients with diethyl-OPs required intubation significantly earlier and showed lower and more sustained inhibited activity of the plasma-cholinesterase on admission compared with patients ingesting dimethyl-OPs. Treatment with atropine and obidoxime was comparable between these groups and severity of poisoning, outcome, hemodynamics on admission, duration of mechanical ventilation and length of stay in the ICU did not significantly differ between the involved group of dimethyl- and diethyl-OPs. We conclude that

  13. Accidental organophosphate insecticide intoxication in children: a reminder

    PubMed Central

    2011-01-01

    Misuse of organophosphate insecticides, even in case of domestic application, can be life threatening. We report the case of siblings admitted with respiratory distress, pinpoint pupils and slurred speech. The symptoms appear after spraying the skin by insecticides. Plasma pseudocholinesterase level appeared to be very low, consistent with acute intoxication with organophosphate insecticide. Management of organophosphate poisoning consists of airway management, administration of oxygen and fluid, as well as atropine in increasing doses and pralidoxime. Decontamination of the patient's skin and the removal of the patient's clothes are mandatory in order to avoid recontamination of the patient as well as the surrounding healthcare personnel. Plasma pseudocholinesterase analysis is a cheap and an easy indicator for organophosphate insecticides intoxications and could be used for diagnosis and treatment monitoring. PMID:21676238

  14. Electrochemical Stripping Analysis of Organophosphate Pesticides and Nerve Agents

    SciTech Connect

    Liu, Guodong; Lin, Yuehe

    2005-03-17

    A sensitive electrochemical stripping voltammetric method for analyzing organophosphate (OP) compounds was developed using a carbon paste electrochemical (CPE) transducer. OPs strongly adsorb on a CPE surface and provide facile electrochemical quantitative methods for electroactive OP compounds. Operational parameters have been optimized, and the stripping voltammetric performance has been studied using square wave voltammetry. The adsorptive stripping voltammetric response is highly linear over the 1-60 μM methyl parathion range examined (2-min adsorption), with a detection limit of 0.05 μmol/L (10 min accumulation) and good precision (RSD=3.2%, n =10). These findings can lead to a widespread use of electrochemical sensors to detect OP contaminates.

  15. The Long-Term Effects of Organophosphates Poisoning as a Risk Factor of CVDs: A Nationwide Population-Based Cohort Study

    PubMed Central

    Lin, Cheng-Li; Chang, Shih-Yu; Sung, Fung-Chang; Tai, Sally C. W.

    2015-01-01

    Background Organophosphorus pesticides are widely used throughout the world. Because of their ease of availability, organophosphorus compounds are commonly used for self-poisoning in developing countries. The acute effects of exposure to organophosphorus pesticides are well known, but the chronic effects are unclear. Recent studies suggest that abnormalities of the central and peripheral nervous systems persisted for up to 5 years after acute poisoning due to a single large dose of organophosphates (OPs). However, the long-term effects on cardiovascular diseases are poorly understood. Methodology/Principal Findings An OPs-exposed cohort (N = 7,561) and an age- and gender-matched control cohort (N = 30,244), both identified from the National Health Insurance Research Database, were compared. We utilized the multivariable Cox proportional model to estimate the risks of developing arrhythmia, coronary artery disease (CAD) and congestive heart failure (CHF). The patients with acute poisoning from OPs had higher incidence rates of arrhythmia (5.89 vs. 3.61 per 1,000 person-years), CAD (9.10 vs. 6.88 per 1,000 person-years), and CHF (3.89 vs. 2.98 per 1,000 person-years) compared with that of the non-OPs poisoning cohort, with a crude subhazard ratio (SHR) of 1.40, 1.13, and 1.12, respectively. Additionally, a significantly higher risk of arrhythmia was observed in the OPs poisoning cohort (adjusted SHR = 1.25) compared with the non-OPs poisoning cohort, particularly in male patients (adjusted SHR = 1.33) and those under 49 years of age (adjusted SHR = 3.16). After accounting for the competing risks of death, there was a higher risk of arrhythmia and CAD during a three year follow-up period (adjusted SHR = 1.50 for arrhythmia; adjusted SHR = 1.10 for CAD). We also found an adjusted SHR of 1.36 associated with developing CHF after 6 years of follow-up for OPs poisoning cohort. Conclusions Acute OPs poisoning may continuously impact human health through mechanisms that are

  16. Neuregulin-1 is neuroprotective in a rat model of organophosphate-induced delayed neuronal injury

    SciTech Connect

    Li, Yonggang; Lein, Pamela J.; Liu, Cuimei; Bruun, Donald A.; Giulivi, Cecilia; Ford, Gregory D.; Tewolde, Teclemichael; Ross-Inta, Catherine; Ford, Byron D.

    2012-07-15

    Current medical countermeasures against organophosphate (OP) nerve agents are effective in reducing mortality, but do not sufficiently protect the CNS from delayed brain damage and persistent neurological symptoms. In this study, we examined the efficacy of neuregulin-1 (NRG-1) in protecting against delayed neuronal cell death following acute intoxication with the OP diisopropylflurophosphate (DFP). Adult male Sprague–Dawley rats were pretreated with pyridostigmine (0.1 mg/kg BW, i.m.) and atropine methylnitrate (20 mg/kg BW, i.m.) prior to DFP (9 mg/kg BW, i.p.) intoxication to increase survival and reduce peripheral signs of cholinergic toxicity but not prevent DFP-induced seizures or delayed neuronal injury. Pretreatment with NRG-1 did not protect against seizures in rats exposed to DFP. However, neuronal injury was significantly reduced in most brain regions by pretreatment with NRG-1 isoforms NRG-EGF (3.2 μg/kg BW, i.a) or NRG-GGF2 (48 μg/kg BW, i.a.) as determined by FluroJade-B labeling in multiple brain regions at 24 h post-DFP injection. NRG-1 also blocked apoptosis and oxidative stress-mediated protein damage in the brains of DFP-intoxicated rats. Administration of NRG-1 at 1 h after DFP injection similarly provided significant neuroprotection against delayed neuronal injury. These findings identify NRG-1 as a promising adjuvant therapy to current medical countermeasures for enhancing neuroprotection against acute OP intoxication. -- Highlights: ► NRG-1 blocked DFP induced neuronal injury. ► NRG-1 did not protect against seizures in rats exposed to DFP. ► NRG-1 blocked apoptosis and oxidative stress in the brains of DFP-intoxicated rats. ► Administration of NRG-1 at 1 h after DFP injection prevented delayed neuronal injury.

  17. Predicting outcomes in organophosphate poisoning based on APACHE II and modified APACHE II scores.

    PubMed

    Eizadi-Mood, N; Saghaei, M; Jabalameli, M

    2007-07-01

    The aim of this study was to evaluate the scores of the Acute Physiology and Chronic Health Evaluation (APACHE) II and a modified APACHE II system (MAS), without parameters of biochemical tests; and to find prognostic value of individual elements of the APACHE II and MAS in predicting outcomes in organophosphate (OP) poisoning. Data were collected from 131 patients. The median (25th-75th percentiles) of APACHE II score for survivors without intubation were found to be lower than those of non survivors or survivors with intubation and ventilation, [4 (1-7); versus 17.5 (7.8-29), and 13.5 (7.8-16.3)]. Logistic regression analysis identified white blood cell (WBC), potassium, Glasgow coma scale (GCS), age and sodium in APACHE II; GCS and mean arterial pressure in MAS system as prognostically valuable. There was no statistically significance difference between APACHE II and MAS scores in terms of area under Receiver Operating Characteristic Curve [(0.902, 95% confidence interval: (0.837-0.947) for APACHE II), and (0.892, 95% confidence interval: (0.826-0.940) for MAS); P=0.74) to predict need for intubation. It is concluded usage of MAS facilitates the prognostication of the OP poisoned patients due to simplicity, less time-consuming and effectiveness in an emergency situation.

  18. Semen quality in Peruvian pesticide applicators: association between urinary organophosphate metabolites and semen parameters

    PubMed Central

    Yucra, Sandra; Gasco, Manuel; Rubio, Julio; Gonzales, Gustavo F

    2008-01-01

    Background Organophosphates are broad class of chemicals widely used as pesticides throughout the world. We performed a cross-sectional study of associations between dialkylphosphate metabolites of organophosphates and semen quality among pesticide applicators in Majes (Arequipa), Peru. Methods Thirty-one men exposed to organophosphate (OP) pesticides and 31 non-exposed were recruited (age, 20–60 years). In exposed subjects, semen and a blood sample were obtained one day after the last pesticide application. Subjects were grouped according to levels of OP metabolites in urine. Semen samples were analyzed for sperm concentration, percentage of sperm motility, percentage of normal morphology, semen leucocytes and concentrations of fructose and zinc. Exposure to OP was assessed by measuring six urinary OP metabolites (dimethyl and diethyl phosphates and thiophosphates) by gas chromatography using a single flame photometric detector. Results Diethyldithiophosphate (p = 0.04) and diethylthiophosphate (p = 0.02) better reflected occupational pesticide exposure than other OP metabolites. Semen analysis revealed a significant reduction of semen volume and an increase in semen pH in men with OP metabolites. Multiple regression analysis showed that both occupational exposure to pesticides and the time of exposure to pesticides were more closely related to alterations in semen quality parameters than the single measurement of OP metabolites in urine. Conclusion The study demonstrated that occupational exposure to OP pesticides was more closely related to alterations in semen quality than a single measurement of urine OP metabolites. Current measurement of OP metabolites in urine may not reflect the full risk. PMID:19014632

  19. Mechanism-Based Analysis of Acetylcholinesterase Inhibitory Potency of Organophosphates, Carbamates, and Their Analogs

    EPA Science Inventory

    Acetylcholinesterase (AChE) is a key enzyme in the nervous system of animals, terminating impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine. Organophosphate (OP) and carbamate esters can inhibit acetylcholinesterase (AChE) by binding covalently to a s...

  20. BIOSENSOR FOR DIRECT DETERMINATION OF ORGANOPHOSPHATE NERVE AGENTS. 1. POTENTIOMETRIC ENZYME ELECTRODE. (R823663)

    EPA Science Inventory

    A potentiometric enzyme electrode for the direct measurement of organophosphate (OP)
    nerve agents was developed. The basic element of this enzyme electrode was a pH electrode
    modified with an immobilized organophosphorus hydrolase (OPH) layer formed by cross-linking
    OPH ...

  1. The Association Between Ambient Exposure to Organophosphates and Parkinson’s Disease Risk

    PubMed Central

    Wang, Anthony; Cockburn, Myles; Ly, Thomas T.; Bronstein, Jeff; Ritz, Beate

    2014-01-01

    Objectives There is a general consensus that pesticides are involved in the etiology of Parkinson’s disease (PD), although associations between specific pesticides and the risk of developing Parkinson’s disease have not been well studied. This study examines the risk of developing PD associated with specific organophosphate pesticides and their mechanisms of toxicity. Methods This case-control study uses a geographic information system (GIS)-based exposure assessment tool to estimate ambient exposure to 36 commonly used organophosphates (OPs) from 1974-1999. All selected OPs were analyzed individually and also in groups formed according to their presumed mechanisms of toxicity. Results The study included 357 incident PD cases and 752 population controls living in the Central Valley of California. Ambient exposure to each OP evaluated separately increased the risk of developing PD. However, most participants were exposed to combinations of OPs rather than a single pesticide. Risk estimates for OPs grouped according to different presumed functionalities and toxicities were similar and did not allow us to distinguish between them. However, we observed exposure-response patterns with exposure to an increasing number of OPs. Conclusions This study adds strong evidence that OPs are implicated in the etiology of idiopathic PD. However, studies of OPs at low doses reflective of real-world ambient exposure are needed to determine the mechanisms of neurotoxicity. PMID:24436061

  2. Developmental exposure to organophosphate flame retardants elicits overt toxicity and alters behavior in early life stage zebrafish (Danio rerio).

    PubMed

    Dishaw, Laura V; Hunter, Deborah L; Padnos, Beth; Padilla, Stephanie; Stapleton, Heather M

    2014-12-01

    Organophosphate flame retardants (OPFRs) are common replacements for the phased-out polybrominated diphenyl ethers (PBDEs) and have been detected at high concentrations in environmental samples. OPFRs are structurally similar to organophosphate pesticides and may adversely affect the developing nervous system. This study evaluated the overt toxicity, uptake, and neurobehavioral effects of tris (1,3-dichloro-2-propyl) phosphate (TDCPP), tris (2-chloroethyl) phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCPP), and tris (2,3-dibromopropyl) phosphate (TDBPP) in early life stage zebrafish. Chlorpyrifos was used as a positive control. For overt toxicity and neurobehavioral assessments, zebrafish were exposed from 0 to 5 days postfertilization (dpf). Hatching, death, or malformations were evaluated daily. Teratogenic effects were scored by visual examination on 6 dpf. To evaluate uptake and metabolism, zebrafish were exposed to 1 µM of each organophosphate (OP) flame retardant and collected on 1 and 5 dpf to monitor accumulation. Larval swimming activity was measured in 6 dpf larvae to evaluate neurobehavioral effects of exposures below the acute toxicity threshold. TDBPP elicited the greatest toxicity at >1 µM. TDCPP and chlorpyrifos were overtly toxic at concentrations ≥10 µM, TCEP, and TCPP were not overtly toxic at the doses tested. Tissue concentrations increased with increasing hydrophobicity of the parent chemical after 24 h exposures. TDCPP and TDBPP and their respective metabolites were detected in embryos on 5 dpf. For all chemicals tested, developmental exposures that were not overtly toxic significantly altered larval swimming activity. These data indicate that OPFRs adversely affect development of early life stage zebrafish.

  3. Developmental Exposure to Organophosphate Flame Retardants Elicits Overt Toxicity and Alters Behavior in Early Life Stage Zebrafish (Danio rerio)

    PubMed Central

    Dishaw, Laura V.; Hunter, Deborah L.; Padnos, Beth; Padilla, Stephanie; Stapleton, Heather M.

    2014-01-01

    Organophosphate flame retardants (OPFRs) are common replacements for the phased-out polybrominated diphenyl ethers (PBDEs) and have been detected at high concentrations in environmental samples. OPFRs are structurally similar to organophosphate pesticides and may adversely affect the developing nervous system. This study evaluated the overt toxicity, uptake, and neurobehavioral effects of tris (1,3-dichloro-2-propyl) phosphate (TDCPP), tris (2-chloroethyl) phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCPP), and tris (2,3-dibromopropyl) phosphate (TDBPP) in early life stage zebrafish. Chlorpyrifos was used as a positive control. For overt toxicity and neurobehavioral assessments, zebrafish were exposed from 0 to 5 days postfertilization (dpf). Hatching, death, or malformations were evaluated daily. Teratogenic effects were scored by visual examination on 6 dpf. To evaluate uptake and metabolism, zebrafish were exposed to 1 µM of each organophosphate (OP) flame retardant and collected on 1 and 5 dpf to monitor accumulation. Larval swimming activity was measured in 6 dpf larvae to evaluate neurobehavioral effects of exposures below the acute toxicity threshold. TDBPP elicited the greatest toxicity at >1 µM. TDCPP and chlorpyrifos were overtly toxic at concentrations ≥10 µM, TCEP, and TCPP were not overtly toxic at the doses tested. Tissue concentrations increased with increasing hydrophobicity of the parent chemical after 24 h exposures. TDCPP and TDBPP and their respective metabolites were detected in embryos on 5 dpf. For all chemicals tested, developmental exposures that were not overtly toxic significantly altered larval swimming activity. These data indicate that OPFRs adversely affect development of early life stage zebrafish. PMID:25239634

  4. NMDA antagonists exert distinct effects in experimental organophosphate or carbamate poisoning in mice

    SciTech Connect

    Dekundy, Andrzej . E-mail: andrzej.dekundy@merz.de; Kaminski, Rafal M.; Zielinska, Elzbieta; Turski, Waldemar A.

    2007-03-15

    Organophosphate (OP) and carbamate acetylcholinesterase (AChE) inhibitors produce seizures and lethality in mammals. Anticonvulsant and neuroprotective properties of N-methyl-D-aspartate (NMDA) antagonists encourage the investigation of their effects in AChE inhibitor-induced poisonings. In the present study, the effects of dizocilpine (MK-801, 1 mg/kg) or 3-((RS)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP, 10 mg/kg), alone or combined with muscarinic antagonist atropine (1.8 mg/kg), on convulsant and lethal properties of an OP pesticide dichlorvos or a carbamate drug physostigmine, were studied in mice. Both dichlorvos and physostigmine induced dose-dependent seizure activity and lethality. Atropine did not prevent the occurrence of convulsions but decreased the lethal effects of both dichlorvos and physostigmine. MK-801 or CPP blocked or attenuated, respectively, dichlorvos-induced convulsions. Contrariwise, NMDA antagonists had no effect in physostigmine-induced seizures or lethality produced by dichlorvos or physostigmine. Concurrent pretreatment with atropine and either MK-801 or CPP blocked or alleviated seizures produced by dichlorvos, but not by physostigmine. Both MK-801 and CPP co-administered with atropine enhanced its antilethal effects in both dichlorvos and physostigmine poisoning. In both saline- and AChE inhibitor-treated mice, no interaction of the investigated antidotes with brain cholinesterase was found. The data indicate that both muscarinic ACh and NMDA receptor-mediated mechanisms contribute to the acute toxicity of AChE inhibitors, and NMDA receptors seem critical to OP-induced seizures.

  5. NMDA antagonists exert distinct effects in experimental organophosphate or carbamate poisoning in mice.

    PubMed

    Dekundy, Andrzej; Kaminski, Rafal M; Zielinska, Elzbieta; Turski, Waldemar A

    2007-03-01

    Organophosphate (OP) and carbamate acetylcholinesterase (AChE) inhibitors produce seizures and lethality in mammals. Anticonvulsant and neuroprotective properties of N-methyl-D-aspartate (NMDA) antagonists encourage the investigation of their effects in AChE inhibitor-induced poisonings. In the present study, the effects of dizocilpine (MK-801, 1 mg/kg) or 3-((RS)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP, 10 mg/kg), alone or combined with muscarinic antagonist atropine (1.8 mg/kg), on convulsant and lethal properties of an OP pesticide dichlorvos or a carbamate drug physostigmine, were studied in mice. Both dichlorvos and physostigmine induced dose-dependent seizure activity and lethality. Atropine did not prevent the occurrence of convulsions but decreased the lethal effects of both dichlorvos and physostigmine. MK-801 or CPP blocked or attenuated, respectively, dichlorvos-induced convulsions. Contrariwise, NMDA antagonists had no effect in physostigmine-induced seizures or lethality produced by dichlorvos or physostigmine. Concurrent pretreatment with atropine and either MK-801 or CPP blocked or alleviated seizures produced by dichlorvos, but not by physostigmine. Both MK-801 and CPP co-administered with atropine enhanced its antilethal effects in both dichlorvos and physostigmine poisoning. In both saline- and AChE inhibitor-treated mice, no interaction of the investigated antidotes with brain cholinesterase was found. The data indicate that both muscarinic ACh and NMDA receptor-mediated mechanisms contribute to the acute toxicity of AChE inhibitors, and NMDA receptors seem critical to OP-induced seizures.

  6. Microbial biosensors for organophosphate pesticides.

    PubMed

    Mulchandani, Ashok; Rajesh

    2011-09-01

    Organophosphates, amongst the most toxic substance known, are used widely in agriculture around the world. Their extensive use, however, has resulted in their occurrence in the water and food supply threatening humans and animals. Therefore, there is a need for determination of these neurotoxic compounds sensitively, selectively, and rapidly in the field. The present work is a brief review on the recent advancements in amperometric, potentiometric, and optical biosensors using genetically engineered microorganisms expressing organophosphate hydrolyzing enzyme intracellularly or anchored on the cell surface for the detection of organophosphate pesticides. The benefits and limitations associated with such microbial biosensors are delineated.

  7. Body mass index as a prognostic factor in organophosphate-poisoned patients.

    PubMed

    Lee, Duk Hee; Jung, Koo Young; Choi, Yoon Hee; Cheon, Young Jin

    2014-07-01

    Organophosphate poisoning is a serious clinical entity and considerable morbidity and mortality. Several factors have been identified to predict outcomes of organophosphate poisoning. Organophosphates are lipophilic and therefore predicted to have a large volume of distribution and to rapidly distribute into tissue and fat. Thus, toxic effects of organophosphate would be expected to last longer in obese patients. We investigated the relationship between obesity and clinical course in 112 acute organophosphate-poisoned patients from an initial medical record review of 234 patients. One hundred twenty-two patients were excluded: 6 were children, 14 had an uncertain history of exposure and of uncertain agent, 10 were transferred to another hospital, 67 were discharged from the emergency department because their toxicity was mild, 21 had carbamate poisoning, and 4 did not have height or weight checked. Clinical features, body mass index, Glasgow Coma Scale, laboratory findings, serum cholinesterase activity, electrocardiogram finding, management, and outcomes were examined. The lipid solubility of the implicated organophosphate was characterized by its octanol/water coefficient. Forty of 112 patients were obese. Obese patients who were poisoned by high lipophilicity organophosphate compounds had a need for longer use of mechanical ventilation, intensive care unit care, and total length of admission. Body mass index can provide a guide to physicians in predicting clinical course and management in organophosphate-poisoned patients.

  8. Organophosphate and carbamate poisoning.

    PubMed

    Bardin, P G; van Eeden, S F; Moolman, J A; Foden, A P; Joubert, J R

    1994-07-11

    Organophosphate insecticides may cause serious poisoning either accidentally or by deliberate ingestion. Toxic symptoms are produced by acetylcholine accumulation at cholinergic receptors. Diagnosis is based on history of exposure or ingestion, symptoms and signs of cholinergic overactivity and a decrease in serum pseudocholinesterase levels. Following diagnosis, grading of disease severity may identify patients with serious poisoning who should receive treatment in intensive care using adequate doses of anticholinergic drugs. Complications, particularly ventricular arrhythmias, central nervous system depression or seizures, and respiratory failure, should be anticipated and treated. Relapse may occur after seemingly successful treatment. Public education with regard to symptoms of toxicity must be encouraged, and physicians must provide skilled treatment for a potentially lethal condition.

  9. Organophosphate pesticides-induced changes in the redox status of rat tissues and protective effects of antioxidant vitamins.

    PubMed

    Mishra, Vibhuti; Srivastava, Nalini

    2015-04-01

    Organophosphates (OPs) pesticides are among the most toxic synthetic chemicals purposefully added in the environment. The common use of OP insecticides in public health and agriculture results in an environmental pollution and a number of acute and chronic poisoning events. Present study was aimed to evaluate the potential of monocrotophos and quinalphos to effect the redox status and glutathione (GSH) homeostasis in rat tissues and find out whether antioxidant vitamins have some protection on the pesticide-induced alterations. The results showed that these pesticides alone or in combination, caused decrease in the levels of GSH and the corresponding increase in the levels of GSSG, decreasing the GSH/GSSG ratio. The results also showed that NADPH/NADP(+) and NADH/NAD(+) ratios were decreased in the liver and brain of rats on exposure with mococrotophos, quinalphos, and their mixture. These pesticides, alone or in combination, caused alterations in the activities of GSH reductase and glucose-6-phosphate dehydrogenase in the rat tissues. However, the expression of the GSH recycling enzymes did not show significant alterations as compared to control. From the results, it can be concluded that these pesticides generate oxidative stress but their effects were not synergistic when given together and prior feeding of antioxidant vitamins tend to reduce the toxicities of these pesticides.

  10. Dichlorvos exposure to the Kölliker-fuse nuclei is sufficient but not necessary for OP induced apnea.

    PubMed

    Gaspari, Romolo J; Dunn, Courtney

    2013-12-01

    Patients exposed to organophosphate (OP) compounds demonstrate a central apnea. The Kölliker-fuse nuclei (KF) are cholinergic nuclei in the brainstem involved in central respiratory control. We hypothesize that exposure of the KF is both necessary and sufficient for OP induced central apnea. We performed an animal study of acute OP exposure. Anesthetized and spontaneously breathing Wistar rats (n=24) were exposed to a lethal dose of dichlorvos using three experimental models. Experiment 1 (n=8) involved systemic OP poisoning using subcutaneous (SQ) 2,2-dichlorovinyl dimethyl phosphate (dichlorvos) at 100mg/kg or 3× LD50. Experiment 2 (n=8) involved isolated poisoning of the KF using stereotactic microinjections of dichlorvos (625μg in 50μl) into the KF. Experiment 3 (n=8) involved systemic OP poisoning with isolated protection of the KF using SQ dichlorvos (100mg/kg) and stereotactic microinjections of organophosphatase A (OpdA), an enzyme that degrades dichlorvos. Respiratory and cardiovascular parameters were recorded continuously. Animals were followed post exposure for 1h or until death. There was no difference in respiratory depression between animals with SQ dichlorvos and those with dichlorvos microinjected into the KF. Despite differences in amount of dichlorvos (100mg/kg vs. 1.8mg/kg) and method of exposure (SQ vs. CNS microinjection), 10min following dichlorvos both groups (SQ vs. microinjection respectively) demonstrated a similar percent decrease in respiratory rate (51.5 vs. 72.2), minute ventilation (49.2 vs. 68.8) and volume of expired gas (17.5 vs. 0.0). Animals with OpdA exposure to the KF during systemic OP exposure demonstrated less respiratory depression, compared to SQ dichlorvos alone (p<0.04). No animals with SQ dichlorvos survived past 25min post exposure, compared to 50% of animals with OpdA exposure to the KF. In conclusion, exposure of the KF is sufficient but not necessary for OP induced apnea. Protection of the KF during systemic OP

  11. Organophosphate Flame Retardants and Plasticizers in Aqueous Solution: pH-Dependent Hydrolysis, Kinetics, and Pathways.

    PubMed

    Su, Guanyong; Letcher, Robert J; Yu, Hongxia

    2016-08-01

    Despite the growing ubiquity of organophosphate (OP) triesters as environmental contaminants, parameters affecting their aquatic chemical stabilities are currently unknown. The present study examined the pH-dependent (7, 9, 11, or 13) hydrolysis of 16 OP triesters in mixtures of 80 ng/mL for each OP triester over a period of 35 days at 20 °C. For the pH = 7, 9, and 11 solutions, 10 of the 16 OP triesters were stable and with no significant (p > 0.05) degradation. For the remaining 6 OP triesters, significant degradation occurred progressing from the pH = 7 to 11 solutions. At pH = 13, except for tributyl phosphate and tris(2-ethylhexyl) phosphate, 14 OP triesters were degraded with half-lives ranging from 0.0053 days (triphenyl phosphate) to 47 days (tripropyl phosphate). With increasingly basic pH the order of OP triester stability was group A (with alkyl moieties) > group B (chlorinated alkyl) > group C (aryl). Numerous OP diesters were identified depending on the pH level of the solution, whereas OP monoesters were not detectable. This is consistent with no significant (p > 0.05) depletion observed for 5 OP diesters in the same 4 solutions and over same 35 day period, suggesting OP diesters are end products of base-catalyzed hydrolysis of OP triesters. Our results demonstrated that pH-dependent hydrolysis of OP triesters does occur, and such instability would likely affect the fate of OP triesters in aqueous environments where the pH can be variable and basic.

  12. Organophosphate Flame Retardants and Plasticizers in Aqueous Solution: pH-Dependent Hydrolysis, Kinetics, and Pathways.

    PubMed

    Su, Guanyong; Letcher, Robert J; Yu, Hongxia

    2016-08-01

    Despite the growing ubiquity of organophosphate (OP) triesters as environmental contaminants, parameters affecting their aquatic chemical stabilities are currently unknown. The present study examined the pH-dependent (7, 9, 11, or 13) hydrolysis of 16 OP triesters in mixtures of 80 ng/mL for each OP triester over a period of 35 days at 20 °C. For the pH = 7, 9, and 11 solutions, 10 of the 16 OP triesters were stable and with no significant (p > 0.05) degradation. For the remaining 6 OP triesters, significant degradation occurred progressing from the pH = 7 to 11 solutions. At pH = 13, except for tributyl phosphate and tris(2-ethylhexyl) phosphate, 14 OP triesters were degraded with half-lives ranging from 0.0053 days (triphenyl phosphate) to 47 days (tripropyl phosphate). With increasingly basic pH the order of OP triester stability was group A (with alkyl moieties) > group B (chlorinated alkyl) > group C (aryl). Numerous OP diesters were identified depending on the pH level of the solution, whereas OP monoesters were not detectable. This is consistent with no significant (p > 0.05) depletion observed for 5 OP diesters in the same 4 solutions and over same 35 day period, suggesting OP diesters are end products of base-catalyzed hydrolysis of OP triesters. Our results demonstrated that pH-dependent hydrolysis of OP triesters does occur, and such instability would likely affect the fate of OP triesters in aqueous environments where the pH can be variable and basic. PMID:27347783

  13. Fe2O3 nanoparticles for airborne organophosphate detection

    NASA Astrophysics Data System (ADS)

    Phillips, Joshua; Soliz, Jennifer; Hauser, Adam

    Dire need for early detection of organophosphates (OP) exists in both civilian (pesticide/herbicide buildup) and military (G/V nerve agents) spheres. Nanoparticle materials are excellent candidates for the detection and/or decontamination of hazardous materials, owing to their large surface to volume ratios and tailored surface functionality. Within this category, metal oxides include structures that are stable with the range of normal environmental conditions (temperature, humidity), but have strong, specific reaction mechanisms (hydrolysis, oxidation, catalysis, stoichiometric reaction) with toxic compounds. In this talk, we will present on the suitability of Fe2O3 nanoparticles as airborne organophosphate detectors. 23 nm particles were exposed to a series of organophosphate compounds (dimethyl methylphosphonate, dimethyl chlorophosphonate, diisopropyl methylphosphonate), and studied by x-ray magnetic circular dichroism and x-ray absorption spectroscopy to confirm the stoichiometric Fe2O3 to FeO mechanism and determine magnetic sensor feasibility. AC Impedance Spectroscopy shows both high sensitivity and selectivity via frequency dependence in both impedance and resistivity, suggesting some feasibility for impedimetric devices. We acknowledge funding under Army Research Office STIR Award #W911F-15-1-0104. J.R.S. acknowledges funding from the Defense Threat Reduction Agency under Projects BA13PHM210 and BA07PRO104. J.R.S. also acknowledges funding under a NRC fellowship.

  14. AMPEROMETRIC THICK-FILM STRIP ELECTRODES FOR MONITORING ORGANOPHOSPHATE NERVE AGENTS BASED ON IMMOBILIZED ORGANOPHOSPHORUS HYDROLASE. (R823663)

    EPA Science Inventory

    An amperometric biosensor based on the immobilization of organophosphorus hydrolase
    (OPH) onto screen-printed carbon electrodes is shown useful for the rapid, sensitive, and low-cost
    detection of organophosphate (OP) nerve agents. The sensor relies upon the sensitive and ra...

  15. Genetic factors potentially reducing fitness cost of organophosphate-insensitive acetylcholinesterase(s) in Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acaricidal activity of organophosphate (OP) and carbamate acaricides is believed to result from inhibition of acetylcholinesterase (AChE). Previous studies in Rhipicephalus (Boophilus) microplus demonstrated the presence of three presumptive AChE genes (BmAChEs). Biochemical characterization of re...

  16. Role of the calcium plateau in neuronal injury and behavioral morbidities following organophosphate intoxication.

    PubMed

    Deshpande, Laxmikant S; Blair, Robert E; Phillips, Kristin F; DeLorenzo, Robert J

    2016-06-01

    Organophosphate (OP) chemicals include nerve agents and pesticides, and there is a growing concern of OP-based chemical attacks against civilians. Current antidotes are essential in limiting immediate mortality associated with OP exposure. However, further research is needed to identify the molecular mechanisms underlying long-term neurological deficits following survival of OP toxicity in order to develop effective therapeutics. We have developed rat survival models of OP-induced status epilepticus (SE) that mimic chronic mortality and morbidity following OP intoxication. We have observed significant elevations in hippocampal calcium levels after OP SE that persisted for weeks following initial survival. Drugs inhibiting intracellular calcium-induced calcium release, such as dantrolene, levetiracetam, and carisbamate, lowered OP SE-mediated protracted calcium elevations. Given the critical role of calcium signaling in modulating behavior and cell death mechanisms, drugs targeted at preventing the development of the calcium plateau could enhance neuroprotection, help reduce morbidity, and improve outcomes following survival of OP SE. PMID:27327161

  17. The prognostic value of the Glasgow coma scale, serum acetylcholinesterase and leukocyte levels in acute organophosphorus poisoning

    PubMed Central

    Cander, Basar; Dur, Ali; Yildiz, Mesut; Koyuncu, Feridun; Girisgin, Abdullah Sadik; Gul, Mehmet; Okumus, Mehmet

    2011-01-01

    BACKGROUND AND OBJECTIVES: Organophosphate poisoning (OP) is a serious clinical condition that may sometimes be fatal. The aim of this study was to determine whether the Glasgow coma scale (GCS), and serum acetylcholinesterase and leukocyte levels have prognostic value in acute OP poisoning. DESIGN AND SETTING: Retrospective review of records of patients admitted to the intensive care unit of Selcuk University, Meram Medical Faculty, Emergency Department, Konya, Turkey, between January 2006 and January 2009. METHODS: We studied acutely OP-poisoned patients admitted within 24 hours after OP exposure. RESULTS: The mean age of the 25 patients was 37 years (range, 20-80 years). Three (12%) of the 25 patients (male-female ratio, 12:13) died. The mean GCS values of the patients who died were significantly lower compared to those of the group that survived (4 vs 11.7, respectively P<.05). While the mean serum acetylcholinesterase levels were lower in the patients who died, the difference in the mean serum acetylcholinesterase levels between the patients who died and the ones who survived was not statistically significant (3841 IU/L vs. 1768 IU/L, respectively). CONCLUSION: Although serum cholinesterase values can be used in the quick diagnosis, their efficiency at predicting outcome in patients with OP poisoning has not been established. It has also been determined that serum leukocyte values have no prognostic value in OP poisoning, but GCS values have been found to be effective in predicting the outcome. PMID:21422653

  18. Caramiphen edisylate: an optimal antidote against organophosphate poisoning.

    PubMed

    Raveh, Lily; Eisenkraft, Arik; Weissman, Ben Avi

    2014-11-01

    Potent cholinesterase inhibitors such as sarin, induce an array of harmful effects including hypersecretion, convulsions and ultimately death. Surviving subjects demonstrate damage in specific brain regions that lead to cognitive and neurological dysfunctions. An early accumulation of acetylcholine in the synaptic clefts was suggested as the trigger of a sequence of neurochemical events such as an excessive outpour of glutamate and activation of its receptors. Indeed, alterations in NMDA and AMPA central receptors' densities were detected in brains of poisoned animals. Attempts to improve the current cholinergic-based treatment by adding potent anticonvulsants or antiglutamatergic drugs produced unsatisfactory results. In light of recent events in Syria and the probability of various scenarios of military or terrorist attacks involving organophosphate (OP) nerve agent, research should focus on finding markedly improved countermeasures. Caramiphen, an antimuscarinic drug with antiglutamatergic and GABAergic facilitating properties, was evaluated in a wide range of animals and experimental protocols against OP poisoning. Its remarkable efficacy against OP exposure was established both in prophylactic and post-exposure therapies in both small and large animals. The present review will highlight the outstanding neuroprotective effect of caramiphen as the optimal candidate for the treatment of OP-exposed subjects.

  19. Quantitative structure-toxicity relationship (QSTR) studies on the organophosphate insecticides.

    PubMed

    Can, Alper

    2014-11-01

    Organophosphate insecticides are the most commonly used pesticides in the world. In this study, quantitative structure-toxicity relationship (QSTR) models were derived for estimating the acute oral toxicity of organophosphate insecticides to male rats. The 20 chemicals of the training set and the seven compounds of the external testing set were described by means of using descriptors. Descriptors for lipophilicity, polarity and molecular geometry, as well as quantum chemical descriptors for energy were calculated. Model development to predict toxicity of organophosphate insecticides in different matrices was carried out using multiple linear regression. The model was validated internally and externally. In the present study, QSTR model was used for the first time to understand the inherent relationships between the organophosphate insecticide molecules and their toxicity behavior. Such studies provide mechanistic insight about structure-toxicity relationship and help in the design of less toxic insecticides.

  20. Recent advancements in sensing techniques based on functional materials for organophosphate pesticides.

    PubMed

    Kumar, Pawan; Kim, Ki-Hyun; Deep, Akash

    2015-08-15

    The use of organophosphate pesticides (OPs) for pest control in agriculture has caused serious environmental problems throughout the world. OPs are highly toxic with the potential to cause neurological disorders in humans. As the application of OPs has greatly increased in various agriculture activities, it has become imperative to accurately monitor their concentration levels for the protection of ecological systems and food supplies. Although there are many conventional methods available for the detection of OPs, the development of portable sensors is necessary to facilitate routine analysis with more convenience. Some of these potent alternative techniques based on functional materials include fluorescence nanomaterials based sensors, molecular imprinted (MIP) sensors, electrochemical sensors, and biosensors. This review explores the basic features of these sensing approaches through evaluation of their performance. The discussion is extended further to describe the challenges and opportunities for these unique sensing techniques.

  1. Organophosphate pesticide method development and presence of chlorpyrifos in the feet of nearctic-neotropical migratory songbirds from Canada that over-winter in Central America agricultural areas.

    PubMed

    Alharbi, Hattan A; Letcher, Robert J; Mineau, Pierre; Chen, Da; Chu, Shaogang

    2016-02-01

    Recent modeling analysis suggests that numerous birds may be at risk of acute poisoning in insecticide-treated fields. Although the majority of avian field studies on pesticides have focused on treated seed, granule, insect or vegetation (oral exposure) ingestion, dermal exposure is an important exposure route when birds come into contact with deposited pesticides on foliage and other surfaces. Some nearctic-neotropical migratory songbirds are likely exposed to pesticides on their non-breeding habitats and include treated crops, plantations or farmlands. In the present study, we developed a method for four environmentally-relevant organophosphate (OP) pesticides (fenthion, fenamiphos, chlorpyrifos and diazinon) in the feet of migratory songbirds (i.e. Common yellowthroat, Gray catbird, Indigo bunting, America redstart, Northern waterthrush, Northern parula, and an additional 12 species of warblers). A total of 190 specimens of the 18 species of songbirds were sampled from available window-killed birds (spring of 2007 and 2011) in downtown Toronto, Canada. The species that were available most likely over-wintered in Mexican/Central American crops such as citrus, coffee and cacao. The feet of the dead birds were sampled and where OP foot exposure likely occurred during over-wintering foraging on pesticide-treated crops. Chlorpyrifos was the only measurable OP (pg mg feet weight(-1)) and in the 2011-collected feet of Black throated blue warbler (0.5), Tennessee warbler (1.0), Northern parula (1.2), Northern waterthrush (0.6), Common yellowthroat (1.0) and the Blue winged warbler (0.9). Dermal contact with OP pesticides during over-wintering in agricultural areas resulted in low levels of chlorpyrifos and long time retention on the feet of a subset of songbirds. PMID:26421621

  2. Organophosphate pesticide method development and presence of chlorpyrifos in the feet of nearctic-neotropical migratory songbirds from Canada that over-winter in Central America agricultural areas.

    PubMed

    Alharbi, Hattan A; Letcher, Robert J; Mineau, Pierre; Chen, Da; Chu, Shaogang

    2016-02-01

    Recent modeling analysis suggests that numerous birds may be at risk of acute poisoning in insecticide-treated fields. Although the majority of avian field studies on pesticides have focused on treated seed, granule, insect or vegetation (oral exposure) ingestion, dermal exposure is an important exposure route when birds come into contact with deposited pesticides on foliage and other surfaces. Some nearctic-neotropical migratory songbirds are likely exposed to pesticides on their non-breeding habitats and include treated crops, plantations or farmlands. In the present study, we developed a method for four environmentally-relevant organophosphate (OP) pesticides (fenthion, fenamiphos, chlorpyrifos and diazinon) in the feet of migratory songbirds (i.e. Common yellowthroat, Gray catbird, Indigo bunting, America redstart, Northern waterthrush, Northern parula, and an additional 12 species of warblers). A total of 190 specimens of the 18 species of songbirds were sampled from available window-killed birds (spring of 2007 and 2011) in downtown Toronto, Canada. The species that were available most likely over-wintered in Mexican/Central American crops such as citrus, coffee and cacao. The feet of the dead birds were sampled and where OP foot exposure likely occurred during over-wintering foraging on pesticide-treated crops. Chlorpyrifos was the only measurable OP (pg mg feet weight(-1)) and in the 2011-collected feet of Black throated blue warbler (0.5), Tennessee warbler (1.0), Northern parula (1.2), Northern waterthrush (0.6), Common yellowthroat (1.0) and the Blue winged warbler (0.9). Dermal contact with OP pesticides during over-wintering in agricultural areas resulted in low levels of chlorpyrifos and long time retention on the feet of a subset of songbirds.

  3. α-Linolenic Acid, A Nutraceutical with Pleiotropic Properties That Targets Endogenous Neuroprotective Pathways to Protect against Organophosphate Nerve Agent-Induced Neuropathology.

    PubMed

    Piermartiri, Tetsade; Pan, Hongna; Figueiredo, Taiza H; Marini, Ann M

    2015-01-01

    α-Linolenic acid (ALA) is a nutraceutical found in vegetable products such as flax and walnuts. The pleiotropic properties of ALA target endogenous neuroprotective and neurorestorative pathways in brain and involve the transcription factor nuclear factor kappa B (NF-κB), brain-derived neurotrophic factor (BDNF), a major neuroprotective protein in brain, and downstream signaling pathways likely mediated via activation of TrkB, the cognate receptor of BDNF. In this review, we discuss possible mechanisms of ALA efficacy against the highly toxic OP nerve agent soman. Organophosphate (OP) nerve agents are highly toxic chemical warfare agents and a threat to military and civilian populations. Once considered only for battlefield use, these agents are now used by terrorists to inflict mass casualties. OP nerve agents inhibit the critical enzyme acetylcholinesterase (AChE) that rapidly leads to a cholinergic crisis involving multiple organs. Status epilepticus results from the excessive accumulation of synaptic acetylcholine which in turn leads to the overactivation of muscarinic receptors; prolonged seizures cause the neuropathology and long-term consequences in survivors. Current countermeasures mitigate symptoms and signs as well as reduce brain damage, but must be given within minutes after exposure to OP nerve agents supporting interest in newer and more effective therapies. The pleiotropic properties of ALA result in a coordinated molecular and cellular program to restore neuronal networks and improve cognitive function in soman-exposed animals. Collectively, ALA should be brought to the clinic to treat the long-term consequences of nerve agents in survivors. ALA may be an effective therapy for other acute and chronic neurodegenerative disorders. PMID:26569216

  4. Detoxification of Organophosphate Poisoning Using Nanoparticle Bioscavengers

    PubMed Central

    Pang, Zhiqing; Hu, Che-Ming J.; Fang, Ronnie H.; Luk, Brian T.; Gao, Weiwei; Wang, Fei; Chuluun, Erdembileg; Angsantikul, Pavimol; Thamphiwatana, Soracha; Lu, Weiyue; Jiang, Xinguo; Zhang, Liangfang

    2016-01-01

    Organophosphate poisoning is highly lethal as organophosphates, which are commonly found in insecticides and nerve agents, cause irreversible phosphorylation and inactivation of acetylcholinesterase (AChE), leading to neuromuscular disorders via accumulation of acetylcholine in the body. Direct interception of organophosphates in the systemic circulation thus provides a desirable strategy in treatment of the condition. Inspired by the presence of acetylcholinesterase on red blood cell (RBC) membranes, we explored a biomimetic nanoparticle consisting of a polymeric core surrounded by RBC membranes to serve as an anti-organophosphate agent. Through in vitro studies, we demonstrated that the biomimetic nanoparticles retain the enzymatic activity of membrane-bound AChE and are able to bind to a model organophosphate, dichlorvos, precluding its inhibitory effect on other enzymatic substrates. In a mouse model of organophosphate poisoning, the nanoparticles were shown to improve the AChE activity in the blood and markedly improved the survival of dichlorvos-challenged mice. PMID:26053868

  5. The effectiveness of an educational intervention to improve knowledge and perceptions for reducing organophosphate pesticide exposure among Indonesian and South Australian migrant farmworkers

    PubMed Central

    Suratman, Suratman; Ross, Kirstin E; Babina, Kateryna; Edwards, John William

    2016-01-01

    Background Farmworkers are at risk of exposure to organophosphate pesticides (OPs). Improvements of knowledge and perceptions about organophosphate (OP) exposure may be of benefit for the reduction in OP exposure. Purpose The purpose of this study was to examine the effectiveness of an educational intervention to improve knowledge and perceptions for reducing OP exposure among Indonesian and South Australian (SA) migrant farmworkers. Methods This was a quasi-experimental study. The educational intervention used a method of group communication for 30 Indonesian farmworkers and individual communication for seven SA migrant farmworkers. Knowledge and perceptions about OP exposure were measured pre-intervention and 3 months after the intervention. Results Unadjusted intervention effects at follow-up showed statistically significantly improved scores of knowledge (both adverse effects of OPs and self-protection from OP exposure), perceived susceptibility, and perceived barriers among Indonesian farmworkers compared with SA migrant farmworkers. Furthermore, these four significant variables in the unadjusted model and the two other variables (perceived severity and perceived benefits) were statistically significant after being adjusted for the level of education and years working as a farmworker. In contrast, knowledge about adverse effects of OPs was the only variable that was statistically significantly improved among SA migrant farmworkers. The results of this study suggests educational interventions using a method of group communication could be more effective than using individual intervention. Conclusion These improvements provide starting points to change health behavior of farmworkers, particularly to reduce OP exposure, both at the workplace and at home. PMID:26855602

  6. Signal-on electrochemiluminescence of biofunctional CdTe quantum dots for biosensing of organophosphate pesticides.

    PubMed

    Liang, Han; Song, Dandan; Gong, Jingming

    2014-03-15

    A new, highly sensitive and selective ECL assay biosensor based on target induced signal on has been developed for the detection of organophosphate pesticides (OPs), whereby the smart integration of graphene nanosheets (GNs), CdTe quantum dots (CdTe QDs), and acetylcholinesterase (AChE) enzymatic reaction yields a biofunctional AChE-GNs-QDs hybrid as cathodic ECL emitters for OPs sensing. The electrochemically synthesized GNs were selected as a supporting material to anchor CdTe QDs, exhibiting a significantly amplified ECL signal of QDs. On the basis of the effect of OPs on the ECL signal of AChE-QDs-GNs modified glassy carbon electrode (GCE), a highly sensitive GNs-anchored-QDs-based signal-on ECL biosensor was developed for sensing OPs, combined with the enzymatic reactions and the dissolved oxygen as coreactant. The conditions for OPs detection were optimized by using methyl parathion (MP) as a model OP compound. Under the optimized experimental conditions, such a newly designed system shows remarkably improved sensitivity and selectivity for the sensing of OPs. The detection limit was found to be as low as about 0.06 ng mL(-1) (S/N=3). Toward the goal for practical applications, the resulting sensor was further evaluated by monitoring MP in spiked vegetable samples, showing fine applicability for the detection of MP in real samples.

  7. Organophosphate-induced brain damage: mechanisms, neuropsychiatric and neurological consequences, and potential therapeutic strategies.

    PubMed

    Chen, Yun

    2012-06-01

    Organophosphate (OP)-induced brain damage is defined as progressive damage to the brain, resulting from the cholinergic neuronal excitotoxicity and dysfunction induced by OP-induced irreversible AChE inhibition. This delayed secondary neuronal damage that occurs mainly in the cholinergic regions of the brain that contain dense accumulations of cholinergic neurons and the majority of cholinergic projection, might be largely responsible for persistent profound neuropsychiatric and neurological impairments (memory, cognitive, mental, emotional, motor and sensory deficits) in the victims of OP poisoning. Neuroprotective strategies for attenuating OP-induced brain damage should target different development stages of OP-induced brain damage, and may include but not limited to: (1) Antidote therapies with atropine and related efficient anticholinergic drugs; (2) Anti-excitotoxic therapies targeting attenuation of cerebral edema and inflammatory reaction, blockage of calcium influx, inhibition of apoptosis program, and the control of seizures; (3) Neuroprotective strategies using cytokines, antioxidants and NMDAR antagonists (a single drug or a combination of drugs) to slow down the process of secondary neuronal damage; and (4) Therapies targeting individual symptoms or clusters of chronic neuropsychiatric and neurological symptoms. These neuroprotective strategies may help limit or prevent secondary neuronal damage at the early stage of OP poisoning and attenuate the subsequent neuropsychiatric and neurological impairments, thus reducing the long-term disability caused by exposure to OPs. PMID:22498093

  8. Electrochemical Sensor for Organophosphate Pesticides and Nerve Agents Using Zirconia Nanoparticles as Selective Sorbents

    SciTech Connect

    Liu, Guodong; Lin, Yuehe

    2005-09-15

    Electrochemical sensor for detection of organophosphate (OP) pesticides and nerve agents using zirconia (ZrO₂) nanoparticles as selective sorbents is presented. Zirconia nanoparticles were electrodynamically deposited onto the polycrystalline gold electrode by cyclic voltammetry. Because of a strong affinity of zirconia to the phosphoric group, nitroaromatic OPs strongly bind to the ZrO₂ nanoparticle surface. The electrochemical characterization and anodic stripping voltammetric performance of bound OPs were evaluated using cyclic voltammetric and square-wave voltammetric (SWV) analysis. SWV was used to monitor the amount of bound OPs and provide simple, fast, and facile quantitative methods for nitroaromatic OP compounds. The sensor surface can be regenerated by successively running SWV scanning. Operational parameters, including the amount of nanoparticles, adsorption time, and the pH of the reaction medium have been optimized. The stripping voltammetric response is highly linear over the 5–200 ng/mL (ppb) methyl parathion range examined (2-min adsorption), with a detection limit of 1 ng/mL (10 min accumulation), and good precision (RSD=5.3 %, n = 10). The promising stripping voltammetric performances open new opportunities for fast, simple, and sensitive analyzing of OPs in environmental and biological samples. These findings can lead to a widespread use of electrochemical sensors to detect OP contaminates.

  9. Increased Risk of Deep Vein Thrombosis and Pulmonary Thromboembolism in Patients With Organophosphate Intoxication

    PubMed Central

    Lim, Yun-Ping; Lin, Cheng-Li; Hung, Dong-Zong; Ma, Wei-Chih; Lin, Yen-Ning; Kao, Chia-Hung

    2015-01-01

    Abstract Organophosphate (OP) poisoning is a critical cause of morbidity and mortality worldwide. We conducted a nationwide longitudinal cohort study to investigate the development of deep vein thrombosis (DVT) and pulmonary thromboembolism (PTE) among patients admitted with OP intoxication. We identified patients with OP intoxication by using the Taiwan National Health Insurance Research Database and enrolled 9223 patients who were hospitalized for OP intoxication between 2000 and 2011. OP intoxication was diagnosed based on a clinical assessment and serum acetylcholinesterase levels at the time of hospital admission. Each patient in the OP intoxication cohort was randomly frequency matched with 4 patients without OP intoxication based on their age, sex, and index year (36,892 patients as control cohort), and all patients were observed from the index date until the appearance of a DVT or a PTE event, or until December 31, 2011. We analyzed the risks of DVT and PTE by using Cox proportional hazards regression models that included the demographic variables of sex, age, and comorbidities (eg, hypertension, diabetes, cerebral vascular disease, heart failure, all cancer types, and lower leg fracture or surgery). The results revealed a significantly increased risk of developing DVT among patients with OP poisoning (adjusted hazard ratio [HR] = 1.55; 95% confidence interval [CI] = 1.03–2.34) but not PTE (adjusted HR = 1.44; 95% CI = 0.83–2.52). Among the patients without comorbidities, the OP poisoning patients compared with controls had a higher adjusted HR of 2.12 (95% CI = 1.21–3.71) for DVT. The results of this nationwide cohort study indicate that the risk of developing DVT is markedly higher in patients with OP intoxication compared with that of the general population. PMID:25569651

  10. A Mechanism-based 3D-QSAR Approach for Classification and Prediction of Acetylcholinesterase Inhibitory Potency of Organophosphate and Carbamate Analogs

    EPA Science Inventory

    Organophosphate (OP) and carbamate esters can inhibit acetylcholinesterase (AChE) by binding covalently to a serine residue in the enzyme active site, and their inhibitory potency depends largely on affinity for the enzyme and the reactivity of the ester. Despite this understandi...

  11. In vitro studies on organophosphate pesticides induced oxidative DNA damage in rat lymphocytes.

    PubMed

    Ojha, A; Srivastava, N

    2014-02-01

    Organophosphate (OP) pesticides are widely used for agricultural and household pest control. We studied the genotoxicity of the commonly used OP pesticides chlorpyrifos (CPF), methyl parathion (MPT), and malathion (MLT), individually and in combination, in Wistar rat peripheral blood lymphocytes in vitro. DNA single-strand and double-strand breaks were measured by single cell gel electrophoresis (SCGE; comet assay). To test whether the DNA lesions were caused by oxidative stress, the DNA repair enzymes formamidoaminopyrimidineglycosylase (Fpg) and endonuclease (Endo III), which convert base damages to strand breaks, were used. Significant increases in strand breaks and in levels of the reactive oxygen species (ROS) superoxide anion and hydrogen peroxide were observed in lymphocytes treated with pesticides. MPT exposure caused the greatest DNA damage and ROS production, followed by CPF and ML. Our results demonstrate genotoxic potential of these OP pesticides.

  12. Case histories of organophosphate pesticides killing birds of prey in the United States

    USGS Publications Warehouse

    Henny, C.J.; Kolbe, E.J.; Hill, E.F.; Blus, L.J.

    1985-01-01

    Since 1982 when secondary. poisoning of Red-tailed Hawks (Buteo jamaicensis) was documented following the recommended use of famphur on cattle, the Patuxent Wildlife Research Center has tested for organophosphate (OP) poisoning in selected birds of prey found dead. This report documents the circumstances for a number of. cases where birds of prey were killed by OP pesticides in the United States. Many of the cases were brought to our attention by the U S. Fish and Wildlife Service Division of Law Enforcement The cases may be divided into three categories: misuse, approved use, and unknown. Now that we are looking for OP poisoning of birds of prey, we are finding it more frequently than previously suspected.

  13. Current and emerging strategies for organophosphate decontamination: special focus on hyperstable enzymes.

    PubMed

    Jacquet, Pauline; Daudé, David; Bzdrenga, Janek; Masson, Patrick; Elias, Mikael; Chabrière, Eric

    2016-05-01

    Organophosphorus chemicals are highly toxic molecules mainly used as pesticides. Some of them are banned warfare nerve agents. These compounds are covalent inhibitors of acetylcholinesterase, a key enzyme in central and peripheral nervous systems. Numerous approaches, including chemical, physical, and biological decontamination, have been considered for developing decontamination methods against organophosphates (OPs). This work is an overview of both validated and emerging strategies for the protection against OP pollution with special attention to the use of decontaminating enzymes. Considerable efforts have been dedicated during the past decades to the development of efficient OP degrading biocatalysts. Among these, the promising biocatalyst SsoPox isolated from the archaeon Sulfolobus solfataricus is emphasized in the light of recently published results. This hyperthermostable enzyme appears to be particularly attractive for external decontamination purposes with regard to both its catalytic and stability properties. PMID:26832878

  14. Surrealism Meets OP

    ERIC Educational Resources Information Center

    Bowden, Jennifer

    2006-01-01

    Kids always seem to like Surrealism and Op Art. This is a fun project that is popular with students. With Op Art patience and attention to details are required while Surrealistic collage needs strong composition skills for the image placement. Often, many images must be left out to create a clean design. Artistic decisions must be based on the art…

  15. Distribution of PON1 polymorphisms PON1Q192R and PON1L55M among Chinese, Malay and Indian males in Singapore and possible susceptibility to organophosphate exposure.

    PubMed

    Chia, Sin Eng; Mohamed Ali, Safiyya; Yap, Peng Huat Eric; Gan, Linda; Ong, Yeong Bing; Chia, Kee Seng

    2009-03-01

    Organophosphate (OP)-containing pesticides are widely used worldwide for domestic and industrial purposes. Studies on acute and chronic exposure to OPs have revealed numerous health effects attributed mainly to acetylcholinesterase (AChE) inhibition. The enzyme human serum paraoxonase (PON1) is involved in the detoxification of OP compounds. PON1 polymorphisms have been shown to affect susceptibility to OP exposure. We studied the effect of OP exposure on pest control workers and assessed the distribution of two common PON1 polymorphisms in our local population. The exposed group consisted of 103 workers from various pest control companies under the Singapore Pest Management Association while the 91 unexposed workers were from a lead stabilizer factory. For all workers, the mean age was 36.9 (20-70) years and the ethnic distribution was 38.1% Chinese, 44.3% Malay and 17.5% Indian. The mean+/-S.D. exposure duration among the pesticide workers was 10.4+/-8.4 years. The mean+/-S.D. RBC cholinesterase level was 18436.2+/-2078U/L and 18079.6+/-1576U/L for the exposed and unexposed groups, respectively (p=0.216). The mean+/-S.D. serum pseudocholinesterase was 11028.4+/-2867.4U/L and 9433.6+/-2022.6U/L in the exposed and unexposed groups, respectively (p<0.0001). Mean paraoxonase activity was similar among Chinese and Malays (266.5 and 266.3U/L, respectively) whereas that of the Indians was significantly lower (165.6U/L). Our study showed that cholinesterase levels among the exposed were not lower than those in the unexposed group. PON1 polymorphisms differed among ethnic groups, implying that ethnicity could be an important surrogate for identifying susceptible groups in case of OP exposure. Although OP poisoning is rare among occupationally exposed workers in Singapore, this information is useful for other developing countries that have large populations of Chinese, Malays and Indians where OP exposure could be very high especially in agricultural settings.

  16. Organophosphate poisoning in a group of replacement heifers and dry cows.

    PubMed Central

    Khan, O

    2001-01-01

    Terbufos ingestion caused acute organophosphate poisoning in 67 Holstein heifers and dry cows, 7 months to 5 years old. Overall mortality was 31%, with attack rates of 4% and 48% for the dry cows and heifers, respectively. Less severely affected animals were treated with atropine sulfate for 7 days. PMID:11467187

  17. Changes in male hormone profile after occupational organophosphate exposure. A longitudinal study.

    PubMed

    Aguilar-Garduño, C; Lacasaña, M; Blanco-Muñoz, J; Rodríguez-Barranco, M; Hernández, A F; Bassol, S; González-Alzaga, B; Cebrián, M E

    2013-05-10

    There is a growing concern about the endocrine effects of long-term, low-level exposure to organophosphate (OP) compounds. Studies on experimental animals have found that OP pesticides have an impact on the endocrine system and a few clinical and epidemiological studies have also shown that OPs may affect the male hormone profile, although results are inconsistent. We have evaluated the effect of exposure to OP pesticides, measured through urinary levels of six dialkylphosphate (DAP) metabolites, on male hormone profile in 136 floriculture workers from the State of Mexico and Morelos during two agricultural periods with different degree of pesticide exposure. Generalized estimated equations (GEE) models were developed and adjusted for several potential confounders, including PON1 enzyme activity, as a biomarker of susceptibility, and serum levels of p,p'-DDE, a metabolite of the pesticide DDT widely used in Mexico until 1999 for control of agricultural pests and malaria. Exposure of male floriculture workers to OP pesticides was associated with increased serum levels of follicle-stimulating hormone (FSH) and prolactin and with decreased serum testosterone and inhibin B levels. Among all DAPs tested, only DETP was inversely associated with luteinizing hormone (LH). Estradiol showed a marginally significant positive trend with DEP and DETP derivatives. In conclusion, OP pesticides may have an impact on the endocrine function because of their potential to modify the male hormone profile as a function of the type of pesticide used as well as the magnitude of exposure.

  18. Aquatic hazard assessment of the organophosphate insecticide fonofos

    USGS Publications Warehouse

    Fairchild, James F.; Little, Edward E.; Huckins, James N.

    1992-01-01

    This study determined the acute and chronic toxicity of the organophosphate insecticide fonofos to standard freshwater aquatic organisms under laboratory conditions. Fonofos was acutely toxic to bluegill (Lepomis macrochirus), Daphnia (D. magna), and midge (Chironomous riparius) at 5.3, 2.7, and 39 μg/L, respectively. Three fonofos formulations (technical, 94.8% A.I.; 20G, field granular 20% A.I.; and 4E, field liquid 4#/gal A.I.) exhibited similar acute toxicities to bluegill. Exposure to fonofos delayed reproduction and decreased the intrinsic rate of increase of Daphnia during 21-d chronic exposure at the lowest tested concentration (0.08 μg/L). The no observable effect concentration (NOEC) for Daphnia survival was 0.42 μg/L; 0% survival occurred at the lowest observable effect concentration (LOEC) of 1.45 μg/L. The NOEC for midge emergence was 3.42 μg/L; only 34% emergence occurred at the LOEC of 8.24 μg/L. Chronic 30-d exposure of juvenile bluegills decreased growth and survival at 5.65 μg/L (LOEC), but no effects occurred at 2.33 μg/L (NOEC). The relative hazard of fonofos to aquatic life is similar to other carbamate and organophosphate corn insecticides.

  19. Seizure activity post organophosphate exposure.

    PubMed

    Tattersall, John

    2009-01-01

    Electrographic seizures are a feature of organophosphate anticholinesterase intoxication. Clinical studies of pesticide poisonings suggest that seizures are more common in children than in adults. Since flaccid paralysis, a characteristic sign of organophosphate poisoning, can mask convulsions, the most reliable indicator of seizures is the electroencephalogram, but this has not been widely used in clinical studies. Seizures can rapidly progress to status epilepticus, contributing to mortality and, in survivors, to neuronal damage and neurological impairment. Anticonvulsant drugs can significantly reduce the lethal and toxic effects of these compounds. A benzodiazepine, usually diazepam, is the treatment currently indicated for control of seizures. Animal studies have indicated that the early phase of seizure activity (0-5 min after seizure onset) is purely cholinergic, predominantly involving muscarinic mechanisms. Seizure activity subsequently progresses through mixed cholinergic and noncholinergic modulation (5-40 min) into a final noncholinergic phase. Neuropathology caused by seizures is most likely associated with glutamatergic excitotoxicity. Future prospects for improved treatments include new benzodiazepines, glutamate receptor antagonists, antimuscarinics with additional antiglutamatergic activity and adenosine receptor antagonists.

  20. Atropine maintenance dosage in patients with severe organophosphate pesticide poisoning.

    PubMed

    Thiermann, Horst; Steinritz, Dirk; Worek, Franz; Radtke, Maria; Eyer, Peter; Eyer, Florian; Felgenhauer, Norbert; Zilker, Thomas

    2011-09-25

    Although the importance of atropine in therapy of organophosphate (OP) poisoning is generally recognized, its dosing is a matter of debate. A retrospective analysis of atropine dosing was undertaken in 34 patients who had been enrolled in a clinical study assessing obidoxime effectiveness in OP-poisoning. All patients were severely intoxicated (suicidal attempts) and required artificial ventilation. Atropine was administered routinely by intensive care physicians for life-threatening muscarinic symptoms, with the recommendation to favor low dosage. The pharmacological active enantiomere S-hyoscyamine was determined by a radioreceptor assay. When RBC-AChE activity ranged between 10% and 30%, S-hyoscyamine plasma concentrations of approx. 5 nmol L⁻¹ were sufficient. This concentration could be maintained with about 0.005 mg h⁻¹ kg⁻¹ atropine. Only when RBC-AChE was completely inhibited, therapy of cholinergic crisis required atropine doses up to 0.06 mg h⁻¹ kg⁻¹. Elimination half-life of S-hyoscyamine was 1.5 h, showing occasionally a second slow elimination phase with t(½)=12 h. Malignant arrhythmias were observed in some 10% of our cases, which occurred late and often in the absence of relevant glandular cholinergic signs, when the S-hyoscyamine concentration was below 2.5 nmol L⁻¹. Arrhythmias mostly resolved on reinstitution of atropine.

  1. Effects of postharvest preparation on organophosphate insecticide residues in apples.

    PubMed

    Rawn, Dorothea F K; Quade, Sue C; Sun, Wing-Fung; Smith, Mark; Fouquet, André; Bélanger, André

    2008-02-13

    Apples were sampled directly from orchard trees at 96, 45, and 21 days postapplication with one of three organophosphate insecticides (azinphos methyl, phosalone, or phosmet, respectively). Individual apples were prepared for analysis following one of three postharvest preparations: no preparation, rinsed with deionized water for 10-15 s, or rinsed and peeled. Azinphos methyl, phosalone, and phosmet concentrations ranged from below the level of detection to 5.26 ng/g, 94.7 to 5720 ng/g, and 0.011 to 663 ng/g in the apples that received no postharvest preparation, respectively. Although rinsed apples had lower maximum concentrations than observed in apples with no preparation, levels were not significantly lower. Concentrations of all three OP insecticides in apples that were rinsed followed by peeling, however, were much lower (below detection limits to 0.733 ng/g, azinphos methyl; 0.322-219 ng/g, phosalone; and below detection limits to 44.0 ng/g, phosmet) than observed in apples that had been rinsed alone. Rinsing and peeling of apples resulted in a 74.5-97.9% reduction in OP residues, while rinsing alone lowered mean concentrations by 13.5-28.7% relative to apples that received no postharvest preparation.

  2. Does Early-Life Exposure to Organophosphate Insecticides Lead to Prediabetes and Obesity?

    PubMed Central

    Slotkin, Theodore A.

    2010-01-01

    Human exposures to organophosphate insecticides are ubiquitous. Although regarded as neurotoxicants, increasing evidence points toward lasting metabolic disruption from early-life organophosphate exposures. We gave neonatal rats chlorpyrifos, diazinon or parathion in doses devoid of any acute signs of toxicity, straddling the threshold for barely-detectable cholinesterase inhibition. Organophosphate exposure during a critical developmental window altered the trajectory of hepatic adenylyl cyclase/cyclic AMP signaling, culminating in hyperresponsiveness to gluconeogenic stimuli. Consequently, the animals developed metabolic dysfunction resembling prediabetes. When the organophosphate-exposed animals consumed a high fat diet in adulthood, metabolic defects were exacerbated and animals gained excess weight compared to unexposed rats on the same diet. At the same time, the high fat diet ameliorated many of the central synaptic defects caused by organophosphate exposure, pointing to nonpharmacologic therapeutic interventions to offset neurodevelopmental abnormalities, as well as toward fostering dietary choices favoring high fat intake. These studies show how common insecticides may contribute to the increased worldwide incidence of obesity and diabetes. PMID:20850519

  3. Coacervate Core Micelles for the Dispersion and Stabilization of Organophosphate Hydrolase in Organic Solvents

    NASA Astrophysics Data System (ADS)

    Mills, Carolyn; Obermeyer, Allie; Dong, Xuehui; Olsen, Bradley D.

    Bulk organophosphate (OP) nerve agents are difficult to decontaminate on site and dangerous to transport. The organophosphate hydrolase (OPH) enzyme is an efficient catalyst for hydrolyzing, and thus decontaminating, these compounds, but suffers from poor stability in the hydrophobic bulk OP environment. Here, we exploit the complex coacervation phase separation phenomenon to form complex coacervate core micelles (C3Ms) that can protect this OPH enzyme under these conditions. Stable C3Ms form when mixing a charged-neutral block copolymer methyl-quaternized poly(4-vinylpyridine)-block-poly(oligo(ethylene glycol) methacrylate) (Qp4vp- b-POEGMA), a homopolymer poly(acrylic acid) (PAA), and OPH under a certain conditions. The C3Ms are then transferred into two organic solvents, ethanol and dimethyl methylphosphonate (DMMP), which is a good simulant for the physical properties of the OP compounds. The C3Ms retain their nanostructures in the organic solvents. The activity test of OPH indicates that the C3Ms successfully protect OPH activity in organic solvents.

  4. Longitudinal trends in organophosphate incidents reported to the National Pesticide Information Center, 1995–2007

    PubMed Central

    2009-01-01

    Background Regulatory decisions to phase-out the availability and use of common organophosphate pesticides among the general public were announced in 2000 and continued through 2004. Based on revised risk assessments, chlorpyrifos and diazinon were determined to pose unacceptable risks. To determine the impact of these decisions, organophosphate (OP) exposure incidents reported to the National Pesticide Information Center (NPIC) were analyzed for longitudinal trends. Methods Non-occupational human exposure incidents reported to NPIC were grouped into pre- (1995–2000) and post-announcement periods (2001–2007). The number of total OP exposure incidents, as well as reports for chlorpyrifos, diazinon and malathion, were analyzed for significant differences between these two periods. The number of informational inquiries from the general public was analyzed over time as well. Results The number of average annual OP-related exposure incidents reported to NPIC decreased significantly between the pre- and post-announcement periods (p < 0.001). A significant decrease in the number of chlorpyrifos and diazinon reports was observed over time (p < 0.001). No significant difference in the number of incident reports for malathion was observed (p = 0.4), which was not phased-out of residential use. Similar to exposure incidents, the number of informational inquiries received by NPIC declined over time following the phase-out announcement. Conclusion Consistent with other findings, the number of chlorpyrifos and diazinon exposure incidents reported to NPIC significantly decreased following public announcement and targeted regulatory action. PMID:19379510

  5. Interactions of organophosphates with keratins in the cornified epithelium of human skin.

    PubMed

    Verstappen, Daan R W; Hulst, Albert G; Fidder, Alex; Vermeulen, Nico P E; Noort, Daan

    2012-05-30

    Methods to unequivocally assess and quantify exposure to organophosphate anti-cholinesterase agents are highly valuable, either from a biomonitoring or a forensic perspective. Since for both OP pesticides and various nerve agents the skin is a predominant route of entry, we hypothesized that proteins in the skin might represent an ideal source of unequivocal and persistent biomarkers for exposure to these compounds. In this exploratory study we show that keratin proteins in human skin are relevant binding sites for organophosphates. The thick cornified epithelium of human plantar skin (callus) was exposed to a selection of relevant organophosphorus compounds and keratin proteins were subsequently extracted. After carboxymethylation of cysteine residues, enzymatic digestion of the keratins with pronase and trypsin was performed and the resulting amino acid and peptides were analyzed to assess whether covalent adducts had formed. LC-tandem MS analysis of the pronase digests demonstrated that tyrosine and to a lesser extent serine residues were selectively modified by organophosphate pesticides (both phosphorothioates and the corresponding oxon forms) under physiological conditions. In addition, modification of tyrosine with the nerve agent VX was unequivocally assessed. In order to elucidate specific binding sites, LC-tandem MS analysis of trypsin digests showed two separate tryptic keratin fragments, i.e. LASY*LDK and SLY*GLGGSK, with Y* the modified tyrosine residues, originating from keratin 1/6 and keratin 10, respectively. These preliminary findings, revealing novel binding targets for anti-cholinesterase organophosphates, will form a firm basis for the development of novel (non-invasive) methods for assessment of exposure to organophosphates. Whether this binding will also have biological implications remains an issue for further investigations.

  6. Organophosphates in aircraft cabin and cockpit air--method development and measurements of contaminants.

    PubMed

    Solbu, Kasper; Daae, Hanne Line; Olsen, Raymond; Thorud, Syvert; Ellingsen, Dag Gunnar; Lindgren, Torsten; Bakke, Berit; Lundanes, Elsa; Molander, Paal

    2011-05-01

    Methods for measurements and the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils among flying personnel in the aviation industry are described. Different sampling methods were applied, including active within-day methods for OPs and VOCs, newly developed passive long-term sample methods (deposition of OPs to wipe surface areas and to activated charcoal cloths), and measurements of OPs in high-efficiency particulate air (HEPA) recirculation filters (n = 6). In total, 95 and 72 within-day OP and VOC samples, respectively, have been collected during 47 flights in six different models of turbine jet engine, propeller and helicopter aircrafts (n = 40). In general, the OP air levels from the within-day samples were low. The most relevant OP in this regard originating from turbine and engine oils, tricresyl phosphate (TCP), was detected in only 4% of the samples (min-max OPs, as dibutylphenyl phosphate (DBPP) and tri-n-butyl phosphate (TnBP) originating from hydraulic oils were more prominent in the samples, illustrated by determination of TnBP in all of the within-day samples collected from airplanes (n = 76, min-max 0.02-4.1 µg m(-3)). All samples were collected under normal flight conditions. However, the TCP concentration during ground testing in an airplane that had experienced leakage of turbine oil with subsequent contamination of the cabin and cockpit air, was an order of magnitude higher as compared to after engine replacement (p = 0.02).

  7. Exposure to airborne organophosphates originating from hydraulic and turbine oils among aviation technicians and loaders.

    PubMed

    Solbu, Kasper; Daae, Hanne Line; Thorud, Syvert; Ellingsen, Dag Gunnar; Lundanes, Elsa; Molander, Paal

    2010-12-01

    This study describes the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils, among ground personnel within the aviation industry. The OPs tri-n-butyl phosphate (TnBP), dibutyl phenyl phosphate (DBPP), triphenyl phosphate (TPP) and tricresyl phosphate (TCP) have been emphasized due to their use in such oils. Oil aerosol/vapor and total volatile organic compounds (tVOCs) in air were also determined. In total, 228 and 182 OPs and oil aerosol/vapor samples from technician and loader work tasks during work on 42 and 21 aircrafts, respectively, were collected in pairs. In general, the measured exposure levels were below the limit of quantification (LOQ) for 84%/98% (oil aerosol) and 82%/90% (TCP) of the samples collected during technician/loader work tasks. The air concentration ranges for all samples related to technician work were OPs) mg m(-3), with the highest OP exposure levels measured during wheel well maintenance. For loader work the corresponding air concentration ranges were OPs) mg m(-3), with the highest exposure levels measured during loading from jet engine aircrafts. Investigation of provoked exposure situations revealed substantially higher exposure levels of the contaminants when compared to regular conditions, illustrated by oil aerosol and TCP concentrations up to 240 and 31 mg m(-3), respectively. The tailored OP and the general oil aerosol sampling methods were compared, displaying the advantages of tailored OP sampling for such exposure assessments.

  8. Organophosphates in aircraft cabin and cockpit air--method development and measurements of contaminants.

    PubMed

    Solbu, Kasper; Daae, Hanne Line; Olsen, Raymond; Thorud, Syvert; Ellingsen, Dag Gunnar; Lindgren, Torsten; Bakke, Berit; Lundanes, Elsa; Molander, Paal

    2011-05-01

    Methods for measurements and the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils among flying personnel in the aviation industry are described. Different sampling methods were applied, including active within-day methods for OPs and VOCs, newly developed passive long-term sample methods (deposition of OPs to wipe surface areas and to activated charcoal cloths), and measurements of OPs in high-efficiency particulate air (HEPA) recirculation filters (n = 6). In total, 95 and 72 within-day OP and VOC samples, respectively, have been collected during 47 flights in six different models of turbine jet engine, propeller and helicopter aircrafts (n = 40). In general, the OP air levels from the within-day samples were low. The most relevant OP in this regard originating from turbine and engine oils, tricresyl phosphate (TCP), was detected in only 4% of the samples (min-max OPs, as dibutylphenyl phosphate (DBPP) and tri-n-butyl phosphate (TnBP) originating from hydraulic oils were more prominent in the samples, illustrated by determination of TnBP in all of the within-day samples collected from airplanes (n = 76, min-max 0.02-4.1 µg m(-3)). All samples were collected under normal flight conditions. However, the TCP concentration during ground testing in an airplane that had experienced leakage of turbine oil with subsequent contamination of the cabin and cockpit air, was an order of magnitude higher as compared to after engine replacement (p = 0.02). PMID:21399836

  9. Exposure to airborne organophosphates originating from hydraulic and turbine oils among aviation technicians and loaders.

    PubMed

    Solbu, Kasper; Daae, Hanne Line; Thorud, Syvert; Ellingsen, Dag Gunnar; Lundanes, Elsa; Molander, Paal

    2010-12-01

    This study describes the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils, among ground personnel within the aviation industry. The OPs tri-n-butyl phosphate (TnBP), dibutyl phenyl phosphate (DBPP), triphenyl phosphate (TPP) and tricresyl phosphate (TCP) have been emphasized due to their use in such oils. Oil aerosol/vapor and total volatile organic compounds (tVOCs) in air were also determined. In total, 228 and 182 OPs and oil aerosol/vapor samples from technician and loader work tasks during work on 42 and 21 aircrafts, respectively, were collected in pairs. In general, the measured exposure levels were below the limit of quantification (LOQ) for 84%/98% (oil aerosol) and 82%/90% (TCP) of the samples collected during technician/loader work tasks. The air concentration ranges for all samples related to technician work were OPs) mg m(-3), with the highest OP exposure levels measured during wheel well maintenance. For loader work the corresponding air concentration ranges were OPs) mg m(-3), with the highest exposure levels measured during loading from jet engine aircrafts. Investigation of provoked exposure situations revealed substantially higher exposure levels of the contaminants when compared to regular conditions, illustrated by oil aerosol and TCP concentrations up to 240 and 31 mg m(-3), respectively. The tailored OP and the general oil aerosol sampling methods were compared, displaying the advantages of tailored OP sampling for such exposure assessments. PMID:20949195

  10. Zero valent iron reduces toxicity and concentrations of organophosphate pesticides in contaminated groundwater.

    PubMed

    Fjordbøge, Annika S; Baun, Anders; Vastrup, Troels; Kjeldsen, Peter

    2013-01-01

    The potential of zero valent iron (ZVI) for remediation of contaminated groundwater from an abandoned chemical disposal site was examined through batch and column experiments. The key contaminants were organophosphate pesticides but the chemical analysis also comprised additional 22 compounds including synthesis intermediates and degradation products of organophosphates. The ZVI treatment showed that all the contaminants were degraded with the exception of two diesters (phosphorothioates). The most rapid reduction was found for methyl parathion, ethyl parathion and malathion, which had first-order degradation rate constants on the order of 10(-3) min(-1). In the study, acute toxicity towards freshwater crustaceans (Daphnia magna) was included to evaluate the overall efficiency of ZVI treatment of the complex mixture. The acute toxicity tests with D. magna showed that the untreated groundwater was highly toxic. Thus, 50% of the daphnids were unable to swim upon 24h exposure to groundwater diluted 770 times. ZVI facilitated degradation resulted in a complete toxicity removal for the first four pore volumes, where after a three times dilution caused 50% inhibition of the mobility of the daphnids. The rapid degradation of the highly toxic organophosphates combined with the significant decrease in the ecotoxicological potential shows a promising potential for site remediation of organophosphates with ZVI technologies.

  11. Enzyme-linked immunosorbent assay for detection of organophosphorylated butyrylcholinesterase: A biomarker of exposure to organophosphate agents

    SciTech Connect

    Wang, Liming; Du, Dan; Lu, Donglai; Lin, Chiann Tso; Smith, Jordan N.; Timchalk, Charles; Liu, Fengquan; Wang, Jun; Lin, Yuehe

    2011-05-05

    A sandwich enzyme-linked immunosorbent assay (sELISA) is developed for detection of organophosphorylated butyrylcholinesterase (OP-BChE), a potential biomarker for human exposure to organophosphate insecticides and nerve agents. A pair of antibodies specific to OP-BChE adduct were identified through systematic screening of several anti BChE antibodies (anti-BChE) and anti-phosphoserine antibodies (anti-Pser) from different sources. The selected anti-BChE (set as capture antibody) antibodies recognize both phosphorylated and nonphosphorylated BChE. These antibodies can therefore be used to capture both BChE and OP-BChE from the sample matrices. The anti- Pser (set as detecting antibody) was used to recognize the OP moiety of OP-BChE adducts. With the combination of the selected antibody pair, several key parameters (such as the concentration of anti-BChE and anti-Pser, and the blocking agent) were optimized to enhance the sensitivity and selectivity of the sELISA. Under the optimal conditions, the sELISA has shown a wide linear range from 0.03 nM to 30 nM, with a detection limit of 0.03 nM. Furthermore, the sELISA was successfully applied to detect OP-BChE using in-vitro biological samples such as rat plasma spiked with OP-BChE with excellent adduct recovery (z>99 %). These results demonstrate that this novel approach holds great promise to develop an ELISA kit and offers a simple and cost-effective tool for screening/evaluating exposure to organophosphate insecticides and nerve agents.

  12. [Acute poisoning by pesticides in children].

    PubMed

    Leveau, P

    2016-07-01

    Acute pesticide poisoning in children is rare but potentially serious. Some clinical patterns (toxidromes) are suggestive of the drug class: cholinergic crisis for organophosphate or carbamate insecticides; neurological syndrome for rodenticides; digestive and respiratory syndrome for herbicides. Treatment is symptomatic and only a few patients are treated with an antidote: atropine and pralidoxime for organophosphate insecticides, vitamin K for anticoagulant rodenticides. PMID:27266642

  13. Peripheral Nervous System Function and Organophosphate Pesticide Use among Licensed Pesticide Applicators in the Agricultural Health Study

    PubMed Central

    Starks, Sarah E.; Hoppin, Jane A.; Kamel, Freya; Lynch, Charles F.; Jones, Michael P.; Alavanja, Michael C.; Sandler, Dale P.

    2012-01-01

    Background: Evidence is limited that long-term human exposure to organophosphate (OP) pesticides, without poisoning, is associated with adverse peripheral nervous system (PNS) function. Objective: We investigated associations between OP pesticide use and PNS function by administering PNS tests to 701 male pesticide applicators in the Agricultural Health Study (AHS). Methods: Participants completed a neurological physical examination (NPx) and electrophysiological tests as well as tests of hand strength, sway speed, and vibrotactile threshold. Self-reported information on lifetime use of 16 OP pesticides was obtained from AHS interviews and a study questionnaire. Associations between pesticide use and measures of PNS function were estimated with linear and logistic regression controlling for age and outcome-specific covariates. Results: Significantly increased odds ratios (ORs) were observed for associations between ever use of 10 of the 16 OP pesticides and one or more of six NPx outcomes. Most notably, abnormal toe proprioception was significantly associated with ever use of 6 OP pesticides, with ORs ranging from 2.03 to 3.06; monotonic increases in strength of association with increasing use was observed for 3 of the 6 pesticides. Mostly null associations were observed between OP pesticide use and electrophysiological tests, hand strength, sway speed, and vibrotactile threshold. Conclusions: This study provides some evidence that long-term exposure to OP pesticides is associated with signs of impaired PNS function among pesticide applicators. PMID:22262687

  14. Use of biomarkers to indicate exposure of children to organophosphate pesticides: implications for a longitudinal study of children's environmental health.

    PubMed Central

    Wessels, Denise; Barr, Dana B; Mendola, Pauline

    2003-01-01

    Because of their history of widespread use in the United States and unknown long-term health effects, organophosphate pesticides (OPs) are being considered as a chemical class of interest in planning for the National Children's Study, a longitudinal study of children's environmental health. The availability and appropriate use of biomarkers to determine absorbed doses of environmental chemicals such as OPs are critical issues. Biomarkers of OP exposure are typically measured in blood and urine; however, postpartum meconium has been shown to be a promising matrix for assessing cumulative in utero exposure to the fetus, and studies are currently in progress to determine the utility of using saliva and amniotic fluid as matrices. In this article, we discuss the advantages and disadvantages of the currently available OP exposure monitoring methods (cholinesterase inhibition in blood, pesticides in blood, metabolites in urine and alternative matrices); study design issues for a large, long-term study of children's environmental health; and current research and future research needs. Because OPs are rapidly metabolized and excreted, the utility of one-time spot measurements of OP biomarkers is questionable unless background exposure levels are relatively stable over time or a specific time frame of interest for the study is identified and samples are collected accordingly. Biomarkers of OP exposure can be a valuable tool in epidemiology of children's environmental health, as long as they are applied and interpreted appropriately. PMID:14644670

  15. Neurodevelopmental effects in children associated with exposure to organophosphate pesticides: A systematic review

    PubMed Central

    Muñoz-Quezada, María Teresa; Lucero, Boris A.; Barr, Dana B.; Steenland, Kyle; Levy, Karen; Ryan, P. Barry; Iglesias, Veronica; Alvarado, Sergio; Concha, Carlos; Rojas, Evelyn; Vega, Catalina

    2013-01-01

    Many studies have investigated the neurodevelopmental effects of prenatal and early childhood exposures to organophosphate (OP) pesticides among children, but they have not been collectively evaluated. The aim of the present article is to synthesize reported evidence over the last decade on OP exposure and neurodevelopmental effects in children. The Data Sources were PubMed, Web of Science, EBSCO, SciVerse Scopus, SpringerLink, SciELO and DOAJ. The eligibility criteria considered were studies assessing exposure to OP pesticides and neurodevelopmental effects in children from birth to 18 years of age, published between 2002 and 2012 in English or Spanish. Twenty-seven articles met the eligibility criteria. Studies were rated for evidential consideration as high, intermediate, or low based upon the study design, number of participants, exposure measurement, and neurodevelopmental measures. All but one of the 27 studies evaluated showed some negative effects of pesticides on neurobehavioral development. A positive dose–response relationship between OP exposure and neurodevelopmental outcomes was found in all but one of the 12 studies that assessed dose–response. In the ten longitudinal studies that assessed prenatal exposure to OPs, cognitive deficits (related to working memory) were found in children at age 7 years, behavioral deficits (related to attention) seen mainly in toddlers, and motor deficits (abnormal reflexes) seen mainly in neonates. No meta-analysis was possible due to different measurements of exposure assessment and outcomes. Eleven studies (all longitudinal) were rated high, 14 studies were rated intermediate, and two studies were rated low. Evidence of neurological deficits associated with exposure to OP pesticides in children is growing. The studies reviewed collectively support the hypothesis that exposure to OP pesticides induces neurotoxic effects. Further research is needed to understand effects associated with exposure in critical windows

  16. Neurodevelopmental effects in children associated with exposure to organophosphate pesticides: a systematic review.

    PubMed

    Muñoz-Quezada, María Teresa; Lucero, Boris A; Barr, Dana B; Steenland, Kyle; Levy, Karen; Ryan, P Barry; Iglesias, Veronica; Alvarado, Sergio; Concha, Carlos; Rojas, Evelyn; Vega, Catalina

    2013-12-01

    Many studies have investigated the neurodevelopmental effects of prenatal and early childhood exposures to organophosphate (OP) pesticides among children, but they have not been collectively evaluated. The aim of the present article is to synthesize reported evidence over the last decade on OP exposure and neurodevelopmental effects in children. The Data Sources were PubMed, Web of Science, EBSCO, SciVerse Scopus, SpringerLink, SciELO and DOAJ. The eligibility criteria considered were studies assessing exposure to OP pesticides and neurodevelopmental effects in children from birth to 18 years of age, published between 2002 and 2012 in English or Spanish. Twenty-seven articles met the eligibility criteria. Studies were rated for evidential consideration as high, intermediate, or low based upon the study design, number of participants, exposure measurement, and neurodevelopmental measures. All but one of the 27 studies evaluated showed some negative effects of pesticides on neurobehavioral development. A positive dose-response relationship between OP exposure and neurodevelopmental outcomes was found in all but one of the 12 studies that assessed dose-response. In the ten longitudinal studies that assessed prenatal exposure to OPs, cognitive deficits (related to working memory) were found in children at age 7 years, behavioral deficits (related to attention) seen mainly in toddlers, and motor deficits (abnormal reflexes) seen mainly in neonates. No meta-analysis was possible due to different measurements of exposure assessment and outcomes. Eleven studies (all longitudinal) were rated high, 14 studies were rated intermediate, and two studies were rated low. Evidence of neurological deficits associated with exposure to OP pesticides in children is growing. The studies reviewed collectively support the hypothesis that exposure to OP pesticides induces neurotoxic effects. Further research is needed to understand effects associated with exposure in critical windows of

  17. Ecotoxicity of two organophosphate pesticides chlorpyrifos and dichlorvos on non-targeting cyanobacteria Microcystis wesenbergii.

    PubMed

    Sun, Kai-Feng; Xu, Xiang-Rong; Duan, Shun-Shan; Wang, You-Shao; Cheng, Hao; Zhang, Zai-Wang; Zhou, Guang-Jie; Hong, Yi-Guo

    2015-10-01

    Organophosphate pesticides (OPs), as a replacement for the organochlorine pesticides, are generally considered non-toxic to plants and algae. Chlorpyrifos and dichlorvos are two OPs used for pest control all over the world. In this study, the dose-response of cyanobacteria Microcystis wesenbergii on OPs exposure and the stimulating effect of OPs with and without phosphorus source were investigated. The results showed that high concentrations of chlorpyrifos and dichlorvos caused significant decrease of chlorophyll a content. The median inhibitory concentrations (EC50) of chlorpyrifos and dichlorvos at 96 h were 15.40 and 261.16 μmol L(-1), respectively. Growth of M. wesenbergii under low concentration of OPs (ranged from 1/10,000 to 1/20 EC50), was increased by 35.85 % (chlorpyrifos) and 41.83 % (dichlorvos) at 120 h, respectively. Correspondingly, the highest enhancement on the maximum quantum yield (F v/F m) was 4.20 % (24 h) and 9.70 % (48 h), respectively. Chlorophyll fluorescence kinetics, known as O-J-I-P transients, showed significant enhancements in the O-J, J-I, and I-P transients under low concentrations of dichlorvos at 144 h, while enhancements of chlorophyll fluorescence kinetics induced by low concentrations of chlorpyrifos were only observed in the J-I transient at 144 h. Significant decreases of chlorophyll content, F v/F m and O-J-I-P transients with OPs as sole phosphorus source were found when they were compared with inorganic phosphate treatments. The results demonstrated an evidently hormetic dose-response of M. wesenbergii to both chlorpyrifos and dichlorvos, where high dose (far beyond environmental concentrations) exposure caused growth inhibition and low dose exposure induced enhancement on physiological processes. The stimulating effect of two OPs on growth of M. wesenbergii was negligible under phosphate limitation.

  18. Care of nestlings by wild female starlings exposed to an organophosphate pesticide

    USGS Publications Warehouse

    Grue, C.E.; Powell, G.V.N.; McChesney, M.J.

    1982-01-01

    (1) Our objective was to determine the effect of exposure to an organophosphate pesticide (OP), dicrotophos (3-hydroxy-N,N-dimethyl-cis-scrotonamide dimethyl phosphate), on care of nestlings by wild female starlings (Sturnus vulgaris)....(2) We selected twelve pairs of active nests based on synchrony in the reproductive cycle. When nestlings were 10 days old (day 10), adult males were captured and killed and brood size was adjusted to four. The frequency and temporal distribution of sorties made by each pair of females to feed their young were recorded for 2 h at 18.00 hours on day 11 and 06.00 hours on day 12. One female from each pair was given a single oral dose of dicrotophos (2.5 mg/kg of body weight) dissolved in corn oil; the second female received an equivalent exposure of pure corn oil. Birds were released and their nestlings weighed. Parental care was again monitored between 18.00 and 20.00 hours on day 12 and 06.00 and 08.00 hours on day 13. Females were then captured and they with their young were weighed and killed. Changes in parental care in OP-dosed and control females were compared using paired t-tests. ....(3) The OP-dosed females made significantly (P < 0.5) fewer sorties to feed their young and remained away from their boxes for longer periods of time than controls. Nestlings of OP-treated females lost significantly more weight (X = 9.3%) than nestlings of controls (X = 3.2%). Brain ChE activity in OP-treated females was inhibited an average of 50.7% compared with controls. Weight changes in OP-dosed (X = -8.9%) and control females (X = -8.3%) were similar.....(4) Results indicate that parental care may be significantly reduced in songbirds receiving severe but sublethal exposure to organophosphate pesticides. The potential for a reduction or modification in parental care to alter reproductive success in passerines is discussed..... (5) Techniques utilized, or modifications thereof, may be useful in collecting the additional data needed to

  19. Association between urinary biomarkers of exposure to organophosphate insecticides and serum reproductive hormones in men from NHANES 1999–2002

    PubMed Central

    Omoike, Ogbebor; Lewis, Ryan C.; Meeker, John D.

    2015-01-01

    Exposure to organophosphate (OP) insecticides may alter reproductive hormone levels in men and increase the risk for poor reductive health and other adverse health outcomes. However, relevant epidemiology studies in men are limited. We evaluated urinary concentrations of OP metabolites (3,5,6-trichloro-2-pyridinol and six dialkyl phosphates) in relation to serum concentrations of testosterone (T) and estradiol among 356 men aged 20–55 years old from the U.S. National Health and Nutrition Examination Survey. Biomarkers were detected in greater than 50% of the samples, except for diethyldithiophosphate, dimethylphosphate, and dimethyldithiophosphate. In adjusted regression models, we observed a statistically significant inverse relationship between diethyl phosphate (DEP) and T when DEP was modeled as either a continuous or categorical variable. These findings add to the limited evidence that exposure to certain OP insecticides is linked to altered T in men, which may have important implications for male health. PMID:25908234

  20. A simultaneous extraction method for organophosphate, pyrethroid, and neonicotinoid insecticides in aqueous samples.

    PubMed

    de Perre, Chloé; Whiting, Sara A; Lydy, Michael J

    2015-05-01

    A method was developed for the extraction and analysis of 2 organophosphate, 8 pyrethroid, and 5 neonicotinoid insecticides from the same water sample. A salted liquid-liquid extraction (LLE) was optimized with a solid-phase extraction (SPE) step that separated the organophosphates (OPs) and pyrethroids from the neonicotinoids. Factors that were optimized included volume of solvent and amount of salt used in the LLE, homogenization time for the LLE, and type and volume of eluting solvent used for the SPE. The OPs and pyrethroids were quantified using gas chromatography-mass spectrometry, and the neonicotinoids were quantified using liquid chromatography-diode array detector. Results showed that the optimized method was accurate, precise, reproducible, and robust; recoveries in river water spiked with 100 ng L(-1) of each of the insecticides were all between 86 and 114 % with RSDs between 2 and 8 %. The method was also sensitive with method detection limits ranging from 0.1 to 27.2 ng L(-1) depending on compounds and matrices. The optimized method was thus appropriate for the simultaneous extraction of 15 widely applied insecticides from three different classes and was shown to provide valuable information on their environmental fate from field-collected aqueous samples.

  1. Urinary Metabolites of Organophosphate and Pyrethroid Pesticides and Neurobehavioral Effects in Chinese Children.

    PubMed

    Wang, Na; Huang, Mengying; Guo, Xinyan; Lin, Ping

    2016-09-01

    Organophosphate (OP) and pyrethroid (PYR) pesticides are widely used in China. However, few studies have investigated the neurobehavioral outcomes of Chinese children exposed to low levels of OP and PYR. We investigated urinary metabolite levels and their association with exposure characteristics and the neurobehavior of children. For all children, biomarker measurements were made in the same interval relative to neurobehavioral testing. We analyzed the morning urine samples of 406 children aged 3-6 years from Nanjing, China. The Kruskal-Wallis and Wilcoxon rank sum tests were used to identify the associations between urinary metabolite levels and exposure characteristics. Multiple linear regression models were used to test the associations between urinary metabolite levels and neurobehavioral test scores after adjusting for covariates (e.g., sex, age, and education expense). The detection of 3,5,6-trichloropyridinol (TCP) and 3-phenoxybenzoic acid (3-PBA) in the urine was positively associated with living areas adjacent to agricultural fields and using indoor mosquito repellent incense. These two metabolites were negatively associated with the soaking time of fruits and vegetables. When treated as dichotomous variables, TCP was significantly associated with arithmetic test scores in adjusted models, and 3-PBA was significantly associated with the scores on the Chinese Binet and arithmetic tests. When treated as a continuous variable, higher urinary 3-PBA levels were significantly associated with lower cancellation test scores. Our findings suggest that exposure to organophosphate and pyrethroid pesticides may have a significant impact on children's working memory and verbal comprehension. PMID:27524288

  2. Carbamate and organophosphate poisoning in early childhood.

    PubMed

    Sofer, S; Tal, A; Shahak, E

    1989-12-01

    Twenty-five infants and young children intoxicated by carbamate and organophosphorus compounds are described. Presenting signs and symptoms in children differed from those described in adults and were mainly related to severe CNS depression, coma and stupor, dyspnea, and flaccidity. Other clinical signs such as miosis, excessive salivation and tearing, sweaty, cold skin, and gastrointestinal symptoms were less frequent, while fasciculations and bradycardia were quite uncommon on arrival. Only two patients presented with all typical signs of organophosphate poisoning as described in adults. Signs of carbamate poisoning were indistinguishable from those of organophosphate poisoning and included signs of myoneural and CNS cholinergic receptor involvement, in addition to parasympathetic muscarinic dysfunction. Atropine sulfate was found to have a clear beneficial CNS effect in addition to its known peripheral antimuscarinic effect. Our data suggest that the clinical presentation of carbamate and organophosphate poisoning in early childhood and its response to therapy are quite different from those of adults and older children.

  3. Visualizing Organophosphate Precipitation at the Calcite-Water Interface by in Situ Atomic-Force Microscopy.

    PubMed

    Wang, Lijun; Qin, Lihong; Putnis, Christine V; Ruiz-Agudo, Encarnación; King, Helen E; Putnis, Andrew

    2016-01-01

    Esters of phosphoric acid constitute a large fraction of the total organic phosphorus (OP) in the soil environment and, thus, play an important role in the global phosphorus cycle. These esters, such as glucose-6-phosphate (G6P), exhibit unusual reactivity toward various mineral particles in soils, especially those containing calcite. Many important processes of OP transformation, including adsorption, hydrolysis, and precipitation, occur primarily at mineral-fluid interfaces, which ultimately governs the fate of organophosphates in the environment. However, little is known about the kinetics of specific mineral-surface-induced adsorption and precipitation of organophosphates. Here, by using in situ atomic-force microscopy (AFM) to visualize the dissolution of calcite (1014) faces, we show that the presence of G6P results in morphology changes of etch pits from the typical rhombohedral to a fan-shaped form. This can be explained by a site-selective mechanism of G6P-calcite surface interactions that stabilize the energetically unfavorable (0001) or (0112) faces through step-specific adsorption of G6P. Continuous dissolution at calcite (1014)-water interfaces caused a boundary layer at the calcite-water interface to become supersaturated with respect to a G6P-Ca phase that then drives the nucleation and growth of a G6P-Ca precipitate. Furthermore, after the introduction of the enzyme alkaline phosphatase (AP), the precipitates were observed to contain a mixture of components associated with G6P-Ca, amorphous calcium phosphate (ACP)-hydroxyapatite (HAP) and dicalcium phosphate dihydrate (DCPD). These direct dynamic observations of the transformation of adsorption- and complexation-surface precipitation and enzyme-mediated pathways may improve the mechanistic understanding of the mineral-interface-induced organophosphate sequestration in the soil environment. PMID:26636475

  4. Visualizing Organophosphate Precipitation at the Calcite-Water Interface by in Situ Atomic-Force Microscopy.

    PubMed

    Wang, Lijun; Qin, Lihong; Putnis, Christine V; Ruiz-Agudo, Encarnación; King, Helen E; Putnis, Andrew

    2016-01-01

    Esters of phosphoric acid constitute a large fraction of the total organic phosphorus (OP) in the soil environment and, thus, play an important role in the global phosphorus cycle. These esters, such as glucose-6-phosphate (G6P), exhibit unusual reactivity toward various mineral particles in soils, especially those containing calcite. Many important processes of OP transformation, including adsorption, hydrolysis, and precipitation, occur primarily at mineral-fluid interfaces, which ultimately governs the fate of organophosphates in the environment. However, little is known about the kinetics of specific mineral-surface-induced adsorption and precipitation of organophosphates. Here, by using in situ atomic-force microscopy (AFM) to visualize the dissolution of calcite (1014) faces, we show that the presence of G6P results in morphology changes of etch pits from the typical rhombohedral to a fan-shaped form. This can be explained by a site-selective mechanism of G6P-calcite surface interactions that stabilize the energetically unfavorable (0001) or (0112) faces through step-specific adsorption of G6P. Continuous dissolution at calcite (1014)-water interfaces caused a boundary layer at the calcite-water interface to become supersaturated with respect to a G6P-Ca phase that then drives the nucleation and growth of a G6P-Ca precipitate. Furthermore, after the introduction of the enzyme alkaline phosphatase (AP), the precipitates were observed to contain a mixture of components associated with G6P-Ca, amorphous calcium phosphate (ACP)-hydroxyapatite (HAP) and dicalcium phosphate dihydrate (DCPD). These direct dynamic observations of the transformation of adsorption- and complexation-surface precipitation and enzyme-mediated pathways may improve the mechanistic understanding of the mineral-interface-induced organophosphate sequestration in the soil environment.

  5. Nosocomial poisoning associated with emergency department treatment of organophosphate toxicity--Georgia, 2000.

    PubMed

    Geller, R J; Singleton, K L; Tarantino, M L; Drenzek, C L; Toomey, K E

    2001-01-01

    Emergency department (ED) staff caring for patients contaminated with toxic chemicals are at risk for developing toxicity from secondary contamination. This report describes three cases of occupational illnesses associated with organophosphate toxicity caused by exposure to a contaminated patient and underscores the importance of using personal protection equipment (PPE) and establishing and following decontamination procedures in EDs and other areas of acute care hospitals. PMID:11327219

  6. Nosocomial poisoning associated with emergency department treatment of organophosphate toxicity--Georgia, 2000.

    PubMed

    2001-01-01

    Emergency department (ED) staff caring for patients contaminated with toxic chemicals are at risk for developing toxicity from secondary contamination. This report describes three cases of occupational illnesses associated with organophosphate toxicity caused by exposure to a contaminated patient and underscores the importance of using personal protection equipment (PPE) and establishing and following decontamination procedures in EDs and other areas of acute care hospitals. PMID:11198947

  7. Creation of a protective pulmonary bioshield against inhaled organophosphates using an aerosolized bioscavenger.

    PubMed

    Rosenberg, Yvonne J; Fink, James B

    2016-06-01

    In addition to the global use of organophosphate (OP) pesticides for agriculture, OP nerve agents and pesticides have been employed on battlefields and by terrorists (e.g., a recent sarin attack in Syria). These occurrences highlight the need for an effective countermeasure against OP exposure. Human butyrylcholinesterase (HuBChE) is a leading candidate, but injection of the high doses required for protection present pharmacokinetic challenges. An aerosolized recombinant form (aer-rHuBChE) that can neutralize inhaled OPs at the portal of entry has been assessed for its efficacy in protecting macaques against respiratory toxicity following inhalation exposure to the pesticide paraoxon (aer-Px). While protection in macaques has been demonstrated using the MicroSprayer® delivery device, administration to humans will likely employ a vibrating mesh nebulizer (VMN). Compared to the 50-70% lung deposition achieved in adult humans with a VMN, deposition in macaques is <5%, an initial major obstacle to demonstrating protection. Such problems have been partly overcome by using a more efficient modified VMN and proportionally higher doses, which together generate an effective rHuBChE pulmonary bioshield and protect against high levels of inhaled Px. PMID:27371808

  8. Novel nucleophiles enhance the human serum paraoxonase 1 (PON1)-mediated detoxication of organophosphates.

    PubMed

    Chambers, Janice E; Chambers, Howard W; Meek, Edward C; Funck, Kristen E; Bhavaraju, Manikanthan H; Gwaltney, Steven R; Pringle, Ronald B

    2015-01-01

    Paraoxonase 1 (PON1) is a calcium-dependent hydrolase associated with serum high-density lipoprotein particles. PON1 hydrolyzes some organophosphates (OPs), including some nerve agents, through nucleophilic attack of hydroxide ion (from water) in the active site. Most OPs are hydrolyzed inefficiently. This project seeks to identify nucleophiles that can enhance PON1-mediated OP degradation. A series of novel nucleophiles, substituted phenoxyalkyl pyridinium oximes, has been synthesized which enhance the degradation of surrogates of sarin (nitrophenyl isopropyl methylphosphonate; NIMP) and VX (nitrophenyl ethyl methylphosphonate; NEMP). Two types of in vitro assays have been conducted, a direct assay using millimolar concentrations of substrate with direct spectrophotometric quantitation of a hydrolysis product (4-nitrophenol) and an indirect assay using submicromolar concentrations of substrate with quantitation by the level of inhibition of an exogenous source of acetylcholinesterase from non-hydrolyzed substrate. Neither NIMP nor NEMP is hydrolyzed effectively by PON1 if one of these novel oximes is absent. However, in the presence of eight novel oximes, PON1-mediated degradation of both surrogates occurs. Computational modeling has created a model of PON1 embedded in phospholipid and has indicated general agreement of the binding enthalpies with the relative efficacy as PON1 enhancers. PON1 enhancement of degradation of OPs could be a unique and unprecedented mechanism of antidotal action. PMID:25304213

  9. The Organophosphate Paraoxon and Its Antidote Obidoxime Inhibit Thrombin Activity and Affect Coagulation In Vitro

    PubMed Central

    Golderman, Valery; Shavit-Stein, Efrat; Tamarin, Ilia; Rosman, Yossi; Shrot, Shai; Rosenberg, Nurit

    2016-01-01

    Organophosphates (OPs) are potentially able to affect serine proteases by reacting with their active site. The potential effects of OPs on coagulation factors such as thrombin and on coagulation tests have been only partially characterized and potential interactions with OPs antidotes such as oximes and muscarinic blockers have not been addressed. In the current study, we investigated the in vitro interactions between coagulation, thrombin, the OP paraoxon, and its antidotes obidoxime and atropine. The effects of these substances on thrombin activity were measured in a fluorescent substrate and on coagulation by standard tests. Both paraoxon and obidoxime but not atropine significantly inhibited thrombin activity, and prolonged prothrombin time, thrombin time, and partial thromboplastin time. When paraoxon and obidoxime were combined, a significant synergistic effect was found on both thrombin activity and coagulation tests. In conclusion, paraoxon and obidoxime affect thrombin activity and consequently alter the function of the coagulation system. Similar interactions may be clinically relevant for coagulation pathways in the blood and possibly in the brain. PMID:27689805

  10. Efficacy of an oximate-based skin decontaminant against organophosphate nerve agents determined in vivo and in vitro.

    PubMed

    Sawyer, T W; Parker, D; Thomas, N; Weiss, M T; Bide, R W

    1991-05-01

    Recent Canadian research efforts have been directed towards the development of a reactive skin decontaminant (RSD) lotion active against classical nerve agents and mustard. The formulation presently under study consists of a 1.25 molal solution of potassium 2,3-butanedione monoximate (KBDO) in polyethylene glycol methylether 550. Although this formulation has shown good efficacy, concern has been expressed as to the potential toxicity of the reaction products of KBDO and organophosphate (OP) nerve agents. This report details the high efficacy of this lotion in inactivating OPs as measured by the systemic toxicity of the OP/RSD mixtures in rats. In addition, primary cultures of chick embryo neurons were also used to test the efficacy of the RSD. By relating the anticholinesterase activity in these cultures of the OP/RSD mixture to that of pure OP standards, a sensitive measure of the value of the RSD in inactivating tabun, sarin, soman and VX was obtained. Experiments with all four nerve agents in this in vitro system provided a good correlation with the in vivo data, and also indicated that the inactivation process was time- and agent-dependent and also related to the ratio of OP to RSD.

  11. Efficacy of an oximate-based skin decontaminant against organophosphate nerve agents determined in vivo and in vitro.

    PubMed

    Sawyer, T W; Parker, D; Thomas, N; Weiss, M T; Bide, R W

    1991-05-01

    Recent Canadian research efforts have been directed towards the development of a reactive skin decontaminant (RSD) lotion active against classical nerve agents and mustard. The formulation presently under study consists of a 1.25 molal solution of potassium 2,3-butanedione monoximate (KBDO) in polyethylene glycol methylether 550. Although this formulation has shown good efficacy, concern has been expressed as to the potential toxicity of the reaction products of KBDO and organophosphate (OP) nerve agents. This report details the high efficacy of this lotion in inactivating OPs as measured by the systemic toxicity of the OP/RSD mixtures in rats. In addition, primary cultures of chick embryo neurons were also used to test the efficacy of the RSD. By relating the anticholinesterase activity in these cultures of the OP/RSD mixture to that of pure OP standards, a sensitive measure of the value of the RSD in inactivating tabun, sarin, soman and VX was obtained. Experiments with all four nerve agents in this in vitro system provided a good correlation with the in vivo data, and also indicated that the inactivation process was time- and agent-dependent and also related to the ratio of OP to RSD. PMID:2048130

  12. Organophosphate and carbamate poisoning: review of the current literature and summary of clinical and laboratory experience in southern Israel.

    PubMed

    Leibson, Tom; Lifshitz, Matitiahu

    2008-11-01

    Organophosphate and carbamate are mainly used to kill insects, thereby protecting livestock, crops, homes and communities. Yet, these compounds also convey great danger. OP and CRB poisoning is an important clinical problem, often life-threatening, especially in the pediatric population in rural areas where reaching a physician or hospital on time is difficult. We present a summary of accumulated toxicological knowledge as well as clinical and laboratory experience from a medical center serving a relatively vast rural area and pediatric population. We stress the importance of knowing how to recognize the classic signs of OP and CRB poisoning and when it is appropriate to investigate for such poisoning even in the absence of those signs. Like any medical emergency, OP and CRB poisoning requires prompt resuscitation and use of antidotes. Atropine, oxygen and fluids are the mainstay of therapy. Oximes, which were found useful in some cases of OP poisoning and useless in some cases of CRB poisoning, are absolutely safe as empiric treatment, which is often needed since the major differential diagnosis of OP poisoning is CRB poisoning, which is clinically indistinguishable. We hope that continuing research will offer further insights into the management of such events, and we are confident that improved medical management of OP and CRB poisoning will result in a reduction of morbidity and other complications associated with intensive care procedures and hospitalization.

  13. Organophosphates and their impact on the global environment.

    PubMed

    Satoh, T; Hosokawa, M

    2000-01-01

    methylphosphonic acid, the hydrolysis product of sarin, bound to AChE in the cerebellums of the victims was separated and identified using GCMS. (3) A sensitive and rapid biomarker of OP-poisoning. Beta-glucuronidase (beta-G) is loosely bound to egasyn which is one of carboxylesterase isozymes in the liver microsomes. The oxon formed from OP in the liver microsomes is covalently bound to egasyn and causes the cleavage of the egasyn-glucuronidase complex, leading to the release of beta-G into the blood. In fact, plasma beta-G activities is a much more sensitive and rapid biomarker than the blood cholinesterase inhibition. In conclusion, OPs cause serious toxicity in both acute and chronic exposures. The epidemiological data in Taiwan and Thailand show that paraquat intoxication cause the most serious irreversible damage in the patients. In 1995, terrorists attack using sarin which is one of the most toxic OP, on the Tokyo subway, and 12 people died. This is an example of the acute intoxication of OP and some people have been still in hospitalized. Recently, the present authors have reported that the plasma beta-G activity is a novel biomarker of OP intoxication. The plasma beta-G is rapidly and significantly increased after OP exposure, and this is a much more sensitive to OP intoxication than ChE inhibition.

  14. Quantitative structure-activity relationships for organophosphates binding to trypsin and chymotrypsin.

    PubMed

    Ruark, Christopher D; Hack, C Eric; Robinson, Peter J; Gearhart, Jeffery M

    2011-01-01

    Organophosphate (OP) nerve agents such as sarin, soman, tabun, and O-ethyl S-[2-(diisopropylamino) ethyl] methylphosphonothioate (VX) do not react solely with acetylcholinesterase (AChE). Evidence suggests that cholinergic-independent pathways over a wide range are also targeted, including serine proteases. These proteases comprise nearly one-third of all known proteases and play major roles in synaptic plasticity, learning, memory, neuroprotection, wound healing, cell signaling, inflammation, blood coagulation, and protein processing. Inhibition of these proteases by OP was found to exert a wide range of noncholinergic effects depending on the type of OP, the dose, and the duration of exposure. Consequently, in order to understand these differences, in silico biologically based dose-response and quantitative structure-activity relationship (QSAR) methodologies need to be integrated. Here, QSAR were used to predict OP bimolecular rate constants for trypsin and α-chymotrypsin. A heuristic regression of over 500 topological/constitutional, geometric, thermodynamic, electrostatic, and quantum mechanical descriptors, using the software Ampac 8.0 and Codessa 2.51 (SemiChem, Inc., Shawnee, KS), was developed to obtain statistically verified equations for the models. General models, using all data subsets, resulted in R(2) values of .94 and .92 and leave-one-out Q(2) values of 0.9 and 0.87 for trypsin and α-chymotrypsin. To validate the general model, training sets were split into independent subsets for test set evaluation. A y-randomization procedure, used to estimate chance correlation, was performed 10,000 times, resulting in mean R(2) values of .24 and .3 for trypsin and α-chymotrypsin. The results show that these models are highly predictive and capable of delineating the complex mechanism of action between OP and serine proteases, and ultimately, by applying this approach to other OP enzyme reactions such as AChE, facilitate the development of biologically based

  15. Effects of organophosphate compounds on a soil protist, Colpoda inflata (Ciliophora, Colpodidae).

    PubMed

    Trielli, Francesca; Chessa, Maria Giovanna; Amaroli, Andrea; Ognibene, Marzia; Delmonte Corrado, Maria Umberta

    2006-12-01

    Many investigations on protists indicate that they play an important role in agricultural soils. We have tested the effects of three organophosphate (OP) pesticides, basudin, cidial, and fenix, on the soil ciliate Colpoda inflata, and examined its viability, fission rate, ability to excyst and extrude macronuclear chromatin into cytoplasm. Exposure to these OPs caused a dose-dependent effect on cell viability, and significantly reduced the mean fission rate at a concentration of 1/10(5) v/v. After exposure of resting cysts to 1/10(5) v/v or 1/10(6) v/v concentrations of basudin or cidial, the number of excysted cells was significantly lower than that of the controls. Conversely, exposure to a 1/10(5) v/v fenix concentration did not affect excystment and exposure to 1/10(6) v/v was found to promote excystment. Moreover, exposure to these OPs (1/10(4) v/v or 1/10(5) v/v) interferred with the ability to extrude macronuclear chromatin. The median lethal concentration in 60 min for each OPs tested was at least a hundred times lower than the doses recommended by the manufacturer. Finally, as the inhibition of cholinesterase (ChE) activity is the first target of OPs, the presence of ChE activity was checked in C. inflata. Three ChE activities were found, hydrolyzing the substrates acetyl-beta-methyl thiocholine iodide, propionyl thiocholine iodide and butyryl thiocholine iodide, that appeared to be very low and not inhibited by OP-exposure.

  16. Microplate spectroscopic methods for determination of the organophosphate soman.

    PubMed

    Prokofieva, Daria Stanislavovna; Voitenko, Natalia Gennadievna; Gustyleva, Lyudmila Konstantinovna; Babakov, Vladimir Nikolaevich; Savelieva, Elena Igorevna; Jenkins, Richard Owen; Goncharov, Nikolay Vasilievich

    2010-06-01

    Two microplate spectroscopic methods for determination of organophosphates, based on inhibition of acetylcholinesterase activity, have been elaborated and evaluated for determination of the chemical weapon agent soman. The principal difference between the methods is that one measures reaction substrate concentration (elaborated from Hestrin), while the other measures reaction product (elaborated from Ellman). The linear ranges of the two methods were found to be similar. Although the limit of quantification was lower for the Ellman method (110 pM), the sensitivity coefficient was in favor of the Hestrin method (1.55-fold higher). The effects of the main soman hydrolysis products were consistent for the two methods: both methylphosphonic acid and pinacolyl methylphosphonic acid did not inhibit acetylcholinesterase activity. The main components of decontaminating solutions showed differential effects: while monoethanolamine had no influence upon results obtained by either method, hydrogen peroxide interfered with the Ellman method at far lower concentrations than with the Hestrin method. In practical applications involving samples containing hydrogen peroxide, the method based on Hestrin should be regarded as much more specific for OP determination than the Ellman method. PMID:20411202

  17. Possible role for anisodamine in organophosphate poisoning.

    PubMed

    Eisenkraft, Arik; Falk, Avshalom

    2016-06-01

    In cases of organophosphate poisoning, patients are treated with a combination of antidotes. In addition to these poison-directed antidotes, patients may require extra oxygen and artificial ventilation; other modalities may also be needed due to the wide range of toxic effects. Anisodamine is a belladonna alkaloid, and like other drugs from this family is non subtype-selective muscarinic, and a nicotinic cholinoceptor antagonist, which has been employed in traditional Chinese medicine. As a muscarinic antagonist, it displays similar pharmacological effects to atropine and scopolamine. However, anisodamine is not only less potent than atropine and scopolamine but also less toxic. Current in vitro and animal model studies have demonstrated that anisodamine has protective effects in a variety of diseases. Organophosphate poisoning involves not only the central and peripheral nervous systems, but also the cardiac and respiratory systems, as well as activation of inflammatory processes and oxidative stress. Therefore, the anticholinergic and additional activities of anisodamine appear to be relevant and justify its consideration as an addition to the existing remedies. However, more research is needed, as at present data on the role of anisodamine in the management of organophosphate poisoning are limited. Here, we review the beneficial effects of anisodamine on processes relevant to organophosphate poisoning.

  18. Liquid chromatography-electrospray-tandem mass spectrometry method for determination of organophosphate diesters in biotic samples including Great Lakes herring gull plasma.

    PubMed

    Su, Guanyong; Greaves, Alana K; Gauthier, Lewis; Letcher, Robert J

    2014-12-29

    Environmentally relevant organophosphate (OP) triester flame retardants are known to degrade to OP diester phosphoric acids. In this study, a quantitatively sensitive method was developed for OP diesters in biological samples of varying complexity, bovine serum, chicken egg homogenate and pork liver. Fortified with 1ng or 10ng each of the six OP diester and six OP triester standards, samples were extracted by accelerated solvent extraction that completely separated OP diesters and triesters. OP diester fractions were cleaned up using weak anion exchange solid phase extraction and eluted with high ionic strength ammonium acetate buffer. Optimal analysis of chlorinated OP diesters was via decamethonium hydroxide dicationic reagent derivatization and by LC-ESI(+)-MS/MS, and for all non-chlorinated OP diesters by non-derivatized LC-ESI(-)-MS/MS. Except for derivatization LC-ESI(+)-MS/MS analysis of liver, at the 10ng spiking level for the three matrices, recovery efficiencies, matrix effects and method limits of quantification (MLOQs) of OP diesters ranged from 55-116%, 92-119%, and 0.02-0.31ng/g wet weight (ww) respectively. Plasma samples of n=6 herring gulls (2010, Chantry Is., Laurentian Great Lakes) contained triphenyl phosphate and tris(1-3-dichloro-2-propyl) phosphate ranging from 1.3 to 4.0ng/g ww and OP diesters bis(1,3-dichloro-2-propyl) phosphate, bis-(2-butoxyethyl) phosphate and di(2-ethylhexyl) phosphate ranged from 0.7 to 3.5ng/g ww, 0.08 to 29.4ng/g ww and OP triester to diester metabolism occurs in exposed wild herring gulls.

  19. Co-op

    2007-05-25

    Co-op is primarily middleware software, a runtime system for the support of the Cooperative Parallel Programming model. This model is based on using whole SPMD applications as components in a scalable programming, and having them treat one another as single objects and communicate via remote method invocation. Also included is some application level software: (1) a metric space database library for managing data items located in an arbitrary metric space and retrieving based on nearestmore » neighbor queries; and (2) a Krieging extrapolation library for use in implementing adaptive sampling for generic multiscale simulations.« less

  20. Co-op

    SciTech Connect

    Nathan Barton, LLNL; Richard Becker, LLNL; Robert Chen, LLNL; Richard Hornung, LLNL; Jaroslaw Knap, LLNL; Gary Kumfert, LLNL; James Leek, LLNL; John May, LLNL; Miller, Patrick; Morrone, Chris; Tannahill, John

    2007-05-25

    Co-op is primarily middleware software, a runtime system for the support of the Cooperative Parallel Programming model. This model is based on using whole SPMD applications as components in a scalable programming, and having them treat one another as single objects and communicate via remote method invocation. Also included is some application level software: (1) a metric space database library for managing data items located in an arbitrary metric space and retrieving based on nearest neighbor queries; and (2) a Krieging extrapolation library for use in implementing adaptive sampling for generic multiscale simulations.

  1. Interpreting population estimates of birds following pesticide applications--behavior of male starlings exposed to an organophosphate pesticide

    USGS Publications Warehouse

    Grue, C.E.; Shipley, B.J.; Ralph, C. John; Scott, J. Michael

    1981-01-01

    We determined activity budgets for 10 pairs of captive male Starlings between 7 May and 18 July 1980. Our objective was to quantify changes in behavior after exposure to an organophosphate (OP) pesticide and to assess the impact of changes in behavior on the interpretation of population estimates of birds following pesticide applications. We observed each pair of males for an hour at 07:30 and 09:30 for four days and classified their behavior into one of four categories: flying, perching, foraging, or singing and displaying. At 06:30 on day 2, one male received a single oral dose of 2.5 mg dicrotophos (3-hydroxy-N, N-dimethyl-cis-crotonamide dimethyl phosphate) per kg of body weight; the other male received an equivalent exposure of corn oil. Changes in the activity budgets of OP-dosed and control males were compared using t-tests. Activity of OP-dosed males was significantly (P _ 0.05) reduced within the 2-4 h following exposure. OP-dosed males spent more time perching (46.1%) than controls and less time flying (-96.6%), foraging (-28.5%), and singing and displaying (-49.5%). The frequency of perching (-75.3%), flying (-83.8%), foraging (-54.1%), and singing and displaying (- 59.2%) was significantly reduced. Activity in OP-dosed males returned to normal by 26-28 h posttreatment. Results suggest that movement and vocalization may be significantly reduced in birds exposed to organophosphate and carbamate pesticides. Conventional censusing techniques and population estimating procedures may, therefore, be inadequate to assess changes in bird populations after pesticide applications because of the difficulty in separating decreases in density due to mortality or emigration from reductions in activity.

  2. Unidirectional cross-tolerance between the carbamate insecticide propoxur and the organophosphate disulfoton in mice.

    PubMed

    Costa, L G; Murphy, S D

    1983-01-01

    Previous studies have shown that subchronic treatment of mice with the organophosphate insecticide, disulfoton, or the carbamate insecticide, propoxur, leads to the development of tolerance to their toxicity. Tolerance to disulfoton was due to a decrease in the number of muscarinic cholinergic receptors, while tolerance to propoxur appeared to be due to an induction of hepatic microsomal enzymes. In the present study we investigated if cross-tolerance between disulfoton and propoxur would occur. Cross-tolerance was evaluated by measuring acute toxicities, cholinesterase and carboxylesterase inhibition and hypothermic and antinociceptive effects. Mice tolerant to propoxur were cross-tolerant to the hypothermic and anticholinesterase effects of disulfoton. Similarly, when mice were pretreated with the microsomal enzyme inducer, phenobarbital, the toxicity of disulfoton was decreased. Mice made tolerant to disulfoton were cross-tolerant to the organophosphate chlorpyrifos, but were more sensitive than controls to the toxicity of propoxur. The acute toxicity of the organophosphate malathion was also increased in disulfoton-tolerant mice. Propoxur is metabolized by mixed function oxidases and possibly by a carboxylesterase. While hepatic microsomal enzymes appeared to be unchanged in disulfoton-tolerant mice, brain and liver carboxylesterase activities were significantly inhibited. Pretreatment of mice with the specific carboxylesterase inhibitor triorthotolylphosphate is known to greatly potentiate the toxicity of malathion and also potentiated, to a lesser extent, the toxicity of propoxur.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Prenatal Exposure to Organophosphate Pesticides and Reciprocal Social Behavior in Childhood

    PubMed Central

    Furlong, Melissa A.; Engel, Stephanie M.; Barr, Dana Boyd; Wolff, Mary S.

    2014-01-01

    Prenatal exposure to organophosphate pesticides (OPs) has been associated with adverse neurodevelopmental outcomes in childhood, including low IQ, Pervasive Developmental Disorder (PDD), attention problems and ADHD. Many of these disorders involve impairments in social functioning. Thus, we investigated the relationship between biomarkers of prenatal OP exposure and impaired reciprocal social behavior in childhood, as measured by the Social Responsiveness Scale (SRS). Using a multi-ethnic urban prospective cohort of mother-infant pairs in New York City recruited between 1998 and 2002 (n=404) we examined the relation between third trimester maternal urinary levels of dialkylphosphate (ΣDAP) OP metabolites and SRS scores among 136 children who returned for the 7–9 year visit. Overall, there was no association between OPs and SRS scores, although in multivariate adjusted models, associations were heterogeneous by race and by sex. Among blacks, each 10-fold increase in total diethylphosphates (ΣDEP) was associated with poorer social responsiveness (β = 5.1 points, 95% confidence interval (CI) 0.8, 9.4). There was no association amongst whites or Hispanics, or for total ΣDAP or total dimethylphosphate (ΣDMP) biomarker levels. Additionally, stratum-specific models supported a stronger negative association among boys for ΣDEPs (β = 3.5 points, 95% CI 0.2, 6.8), with no notable association among girls. Our results support an association of prenatal OP exposure with deficits in social functioning among blacks and among boys, although this may be in part reflective of differences in exposure patterns. PMID:24934853

  4. Environmental exposure to organophosphate pesticides: assessment of endocrine disruption and hepatotoxicity in pregnant women.

    PubMed

    Cecchi, A; Rovedatti, M G; Sabino, G; Magnarelli, G G

    2012-06-01

    In utero exposure is the first point of contact with environmental xenobiotics that may affect the maternal-placental-fetal balance. Considering that maternal pathophysiological changes affect intrauterine development, this pilot study was conducted to address how environmental exposure to organophosphate pesticides (OPs) during pregnancy may contribute to maternal endocrine disruption and disturbed hepatic function. A prospective study was carried out with pregnant women (n=97) living in a rural area of the Rio Negro province where OPs are intensively applied throughout 6 months of the year. Blood samples were obtained and biomarkers of OPs exposure (cholinesterases and β-glucuronidase), cortisol (CT) and progesterone (PG) levels, as well as glycemia, were determined. Parameters of liver injury were assayed by measuring aspartate aminotransferase (AST) and alanine aminotransferase (ALT); liver function was assayed by measuring albumin. Biomonitoring carried out during the pre-spraying period (PreS) and spraying period (SP) showed that the population studied was exposed to OPs, proven by the fact that plasma (PCh) and erythrocyte cholinesterase (AChE) decreased very significantly (p<0.01) during SP. CT values increased very significantly (p<0.01) in the first trimester of pregnancy during SP with respect to PreS. Individual values above the upper limit of the CT and PG reference range were found both in PreS and SP. This finding could be associated with changes in hormone metabolism pathways produced by OPs exposure. During the second trimester of pregnancy there were increases in ALT values and the AST/ALT ratio in SP, suggesting subclinical hepatotoxicity. In SP, glycemia was unchanged while albuminemia increased. Although anthropometric newborn parameters and pregnancy alterations were within normal values for the general population, the increase in CT in the maternal compartment may lead to impaired newborn health later in life.

  5. Distribution and determinants of urinary biomarkers of exposure to organophosphate insecticides in Puerto Rican pregnant women

    PubMed Central

    Lewis, Ryan C.; Cantonwine, David E.; Anzalota Del Toro, Liza V.; Calafat, Antonia M.; Valentin-Blasini, Liza; Davis, Mark D.; Montesano, M. Angela; Alshawabkeh, Akram N.; Cordero, José F.

    2015-01-01

    Globally, human exposures to organophosphate (OP) insecticides may pose a significant burden to the health of mothers and their developing fetuses. Unfortunately, relevant data is limited in certain areas of the world concerning sources of exposure to OP insecticides in pregnant populations. To begin to address this gap in information for Puerto Rico, we studied repeated measures of urinary concentrations of 10 OP insecticide metabolites among 54 pregnant women from the northern karst region of the island. We also collected demographic data and self-reported information on the consumption of fruits, vegetables, and legumes in the past 48-hr before urine collection and home pest-related issues. We calculated the distributions of the urinary biomarkers and compared them to women of reproductive age from the general U.S. population. We also used statistical models accounting for correlated data to assess within-subject temporal variability of the urinary biomarkers and to identify predictors of exposure. We found that for all but two metabolites (para-nitrophenol [PNP], diethylthiophosphate [DETP]), 50th or 95th percentile urinary concentrations (the metric that was used for comparison was based on the biomarker’s detection frequency) of the other eight metabolites (3,5,6-trichloro-2-pyridinol [TCPY], 2-isopropyl-4-methyl-6-hydroxy-pyrimidine, malathion dicarboxylic acid, diethylphosphate, diethyldithiophosphate, dimethylphosphate, dimethylthiophosphate [DMTP], dimethyldithiophosphate) were somewhat lower in our cohort compared with similarly aged women from the continental United States. TCPY, PNP, DETP, and DMTP, which were the only urinary metabolites detected in greater than 50% of the samples, had poor reproducibility (intraclass correlation coefficient range: 0.19–0.28) during pregnancy. Positive predictors of OP insecticide exposure included: age; marital or employment status; consumption of cherries, grape juice, peanuts, peanut butter, or raisins; and

  6. Prenatal exposure to organophosphate pesticides and reciprocal social behavior in childhood.

    PubMed

    Furlong, Melissa A; Engel, Stephanie M; Barr, Dana Boyd; Wolff, Mary S

    2014-09-01

    Prenatal exposure to organophosphate pesticides (OPs) has been associated with adverse neurodevelopmental outcomes in childhood, including low IQ, pervasive developmental disorder (PDD), attention problems and ADHD. Many of these disorders involve impairments in social functioning. Thus, we investigated the relationship between biomarkers of prenatal OP exposure and impaired reciprocal social behavior in childhood, as measured by the Social Responsiveness Scale (SRS). Using a multi-ethnic urban prospective cohort of mother-infant pairs in New York City recruited between 1998 and 2002 (n=404) we examined the relation between third trimester maternal urinary levels of dialkylphosphate (ΣDAP) OP metabolites and SRS scores among 136 children who returned for the 7-9year visit. Overall, there was no association between OPs and SRS scores, although in multivariate adjusted models, associations were heterogeneous by race and by sex. Among blacks, each 10-fold increase in total diethylphosphates (ΣDEP) was associated with poorer social responsiveness (β=5.1 points, 95% confidence interval (CI) 0.8, 9.4). There was no association among whites or Hispanics, or for total ΣDAP or total dimethylphosphate (ΣDMP) biomarker levels. Additionally, stratum-specific models supported a stronger negative association among boys for ΣDEPs (β=3.5 points, 95% CI 0.2, 6.8), with no notable association among girls. Our results support an association of prenatal OP exposure with deficits in social functioning among blacks and among boys, although this may be in part reflective of differences in exposure patterns. PMID:24934853

  7. Distribution and determinants of urinary biomarkers of exposure to organophosphate insecticides in Puerto Rican pregnant women.

    PubMed

    Lewis, Ryan C; Cantonwine, David E; Del Toro, Liza V Anzalota; Calafat, Antonia M; Valentin-Blasini, Liza; Davis, Mark D; Montesano, M Angela; Alshawabkeh, Akram N; Cordero, José F; Meeker, John D

    2015-04-15

    Globally, human exposures to organophosphate (OP) insecticides may pose a significant burden to the health of mothers and their developing fetuses. Unfortunately, relevant data is limited in certain areas of the world concerning sources of exposure to OP insecticides in pregnant populations. To begin to address this gap in information for Puerto Rico, we studied repeated measures of urinary concentrations of 10 OP insecticide metabolites among 54 pregnant women from the northern karst region of the island. We also collected demographic data and self-reported information on the consumption of fruits, vegetables, and legumes in the past 48 h before urine collection and home pest-related issues. We calculated the distributions of the urinary biomarkers and compared them to women of reproductive age from the general U.S. population. We also used statistical models accounting for correlated data to assess within-subject temporal variability of the urinary biomarkers and to identify predictors of exposure. We found that for all but two metabolites (para-nitrophenol [PNP], diethylthiophosphate [DETP]), 50th or 95th percentile urinary concentrations (the metric that was used for comparison was based on the biomarker's detection frequency) of the other eight metabolites (3,5,6-trichloro-2-pyridinol [TCPY], 2-isopropyl-4-methyl-6-hydroxy-pyrimidine, malathion dicarboxylic acid, diethylphosphate, diethyldithiophosphate, dimethylphosphate, dimethylthiophosphate [DMTP], dimethyldithiophosphate) were somewhat lower in our cohort compared with similarly aged women from the continental United States. TCPY, PNP, DETP, and DMTP, which were the only urinary metabolites detected in greater than 50% of the samples, had poor reproducibility (intraclass correlation coefficient range: 0.19-0.28) during pregnancy. Positive predictors of OP insecticide exposure included: age; marital or employment status; consumption of cherries, grape juice, peanuts, peanut butter, or raisins; and

  8. Poisoning severity score, APACHE II and GCS: effective clinical indices for estimating severity and predicting outcome of acute organophosphorus and carbamate poisoning.

    PubMed

    Sam, Kishore Gnana; Kondabolu, Krishnakanth; Pati, Dipanwita; Kamath, Asha; Pradeep Kumar, G; Rao, Padma G M

    2009-07-01

    Self-poisoning with organophosphorus (OP) compounds is a major cause of morbidity and mortality across South Asian countries. To develop uniform and effective management guidelines, the severity of acute OP poisoning should be assessed through scientific methods and a clinical database should be maintained. A prospective descriptive survey was carried out to assess the utility of severity scales in predicting the outcome of 71 organophosphate (OP) and carbamate poisoning patients admitted during a one year period at the Kasturba Hospital, Manipal, India. The Glasgow coma scale (GCS) scores, acute physiology and chronic health evaluation II (APACHE II) scores, predicted mortality rate (PMR) and Poisoning severity score (PSS) were estimated within 24h of admission. Significant correlation (P<0.05) between PSS and GCS and APACHE II and PMR scores were observed with the PSS scores predicting mortality significantly (P< or =0.001). A total of 84.5% patients improved after treatment while 8.5% of the patients were discharged with severe morbidity. The mortality rate was 7.0%. Suicidal poisoning was observed to be the major cause (80.2%), while other reasons attributed were occupational (9.1%), accidental (6.6%), homicidal (1.6%) and unknown (2.5%) reasons. This study highlights the application of clinical indices like GCS, APACHE, PMR and severity scores in predicting mortality and may be considered for planning standard treatment guidelines.

  9. Predictors of exposure to organophosphate pesticides in schoolchildren in the Province of Talca, Chile

    PubMed Central

    Muñoz-Quezada, Maria Teresa; Iglesias, Verónica; Lucero, Boris; Steenland, Kyle; Barr, Dana Boyd; Levy, Karen; Ryan, P. Barry; Alvarado, Sergio; Concha, Carlos

    2012-01-01

    Background Few data exist in Latin America concerning the association between organophosphate (OP) urinary metabolites and the consumption of fruits and vegetables and other exposure risk variables in schoolchildren. Methods We collected samples of urine from 190 Chilean children aged 6-12 years, fruits and vegetables, water and soil from schools and homes, and sociodemographic data through a questionnaire. We measured urinary dialkylphosphate (DAP) OP metabolites and OP pesticide residues in food consumed by these 190 children during two seasons: December 2010 (summer) and May 2011(fall). We analyzed the relationship between urinary DAP concentrations and pesticide residues in food, home pesticide use, and residential location. Results Diethylalkylphosphates (DEAP) and dimethylalkylphosphates (DMAP) were detected in urine in 76% and 27% of samples, respectively. Factors associated with urinary DEAP included chlorpyrifos in consumed fruits (p<0.0001), urinary creatinine (p<0.0001), rural residence (p=0.02) and age less than 9 years (p=0.004). Factors associated with urinary DMAP included the presence of phosmet residues in fruits (p<0.0001), close proximity to a farm (p=0.002), home fenitrothion use (p=0.009), and season (p<0.0001). Conclusions Urinary DAP levels in Chilean school children were high compared previously reported studies. The presence of chlorpyrifos and phosmet residues in fruits was the major factor predicting urinary DAP metabolite concentrations in children. PMID:22732215

  10. The organophosphate-degrading enzyme from Agrobacterium radiobacter displays mechanistic flexibility for catalysis.

    PubMed

    Ely, Fernanda; Hadler, Kieran S; Gahan, Lawrence R; Guddat, Luke W; Ollis, David L; Schenk, Gerhard

    2010-12-15

    The OP (organophosphate)-degrading enzyme from Agrobacterium radiobacter (OpdA) is a binuclear metallohydrolase able to degrade highly toxic OP pesticides and nerve agents into less or non-toxic compounds. In the present study, the effect of metal ion substitutions and site-directed mutations on the catalytic properties of OpdA are investigated. The study shows the importance of both the metal ion composition and a hydrogen-bond network that connects the metal ion centre with the substrate-binding pocket using residues Arg254 and Tyr257 in the mechanism and substrate specificity of this enzyme. For the Co(II) derivative of OpdA two protonation equilibria (pKa1 ~5; pKa2 ~10) have been identified as relevant for catalysis, and a terminal hydroxide acts as the likely hydrolysis-initiating nucleophile. In contrast, the Zn(II) and Cd(II) derivatives only have one relevant protonation equilibrium (pKa ~4-5), and the μOH is the proposed nucleophile. The observed mechanistic flexibility may reconcile contrasting reaction models that have been published previously and may be beneficial for the rapid adaptation of OP-degrading enzymes to changing environmental pressures.

  11. Gas chromatography with pulsed flame photometric detection multiresidue method for organophosphate pesticide and metabolite residues at the parts-per-billion level in representatives commodities of fruits and vegetable crop groups.

    PubMed

    Podhorniak, L V; Negron, J F; Griffith, F D

    2001-01-01

    A gas chromatographic method with a pulsed flame photometric detector (P-FPD) is presented for the analysis of 28 parent organophosphate (OP) pesticides and their OP metabolites. A total of 57 organophosphates were analyzed in 10 representative fruit and vegetable crop groups. The method is based on a judicious selection of known procedures from FDA sources such as the Pesticide Analytical Manual and Laboratory Information Bulletins, combined in a manner to recover the OPs and their metabolite(s) at the part-per-billion (ppb) level. The method uses an acetone extraction with either miniaturized Hydromatrix column partitioning or alternately a miniaturized methylene dichloride liquid-liquid partitioning, followed by solid-phase extraction (SPE) cleanup with graphitized carbon black (GCB) and PSA cartridges. Determination of residues is by programmed temperature capillary column gas chromatography fitted with a P-FPD set in the phosphorus mode. The method is designed so that a set of samples can be prepared in 1 working day for overnight instrumental analysis. The recovery data indicates that a daily column-cutting procedure used in combination with the SPE extract cleanup effectively reduces matrix enhancement at the ppb level for many organophosphates. The OPs most susceptible to elevated recoveries around or greater than 150%, based on peak area calculations, were trichlorfon, phosmet, and the metabolites of dimethoate, fenamiphos, fenthion, and phorate. PMID:11417651

  12. Organophosphates dysregulate dopamine signaling, glutamatergic neurotransmission, and induce neuronal injury markers in striatum.

    PubMed

    Torres-Altoro, Melissa I; Mathur, Brian N; Drerup, Justin M; Thomas, Rachel; Lovinger, David M; O'Callaghan, James P; Bibb, James A

    2011-10-01

    The neurological effects of organophosphate (OP) pesticides, commonly used on foods and in households, are an important public health concern. Furthermore, subclinical exposure to combinations of organophosphates is implicated in Gulf War illness. Here, we characterized the effects of the broadly used insecticide chlorpyrifos (CPF) on dopamine and glutamatergic neurotransmission effectors in corticostriatal motor/reward circuitry. CPF potentiated protein kinase A (PKA)-dependent phosphorylation of the striatal protein dopamine- and cAMP-regulated phosphoprotein of M(r) 32 kDa (DARPP-32) and the glutamate receptor 1 (GluR1) subunit of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in mouse brain slices. It also increased GluR1 phosphorylation by PKA when administered systemically. This correlated with enhanced glutamate release from cortical projections in rat striatum. Similar effects were induced by the sarin congener, diisopropyl fluorophosphate, alone or in combination with the putative neuroprotectant, pyridostigmine bromide and the pesticide N,N-diethyl-meta-toluamide (DEET). This combination, meant to mimic the neurotoxicant exposure encountered by veterans of the 1991 Persian Gulf War, also induced hyperphosphorylation of the neurofibrillary tangle-associated protein tau. Diisopropyl fluorophosphate and pyrodostigmine bromide, alone or in combination, also increased the aberrant activity of the protein kinase, Cdk5, as indicated by conversion of its activating cofactor p35 to p25. Thus, consistent with recent findings in humans and animals, organophosphate exposure causes dysregulation in the motor/reward circuitry and invokes mechanisms associated with neurological disorders and neurodegeneration.

  13. Organophosphate Pesticide Exposures, Nitric Oxide Synthase Gene Variants, and Gene–Pesticide Interactions in a Case–Control Study of Parkinson’s Disease, California (USA)

    PubMed Central

    Paul, Kimberly C.; Sinsheimer, Janet S.; Rhodes, Shannon L.; Cockburn, Myles; Bronstein, Jeff; Ritz, Beate

    2015-01-01

    Background: Nitric oxide synthase (NOS) genes are candidates for Parkinson’s disease (PD) because NOS enzymes produce nitric oxide (NO), a pro-oxidant that can damage neurons. Widely used organophosphate (OP) pesticides can induce oxidative stress and are reported to increase PD risk. Additionally, two single nucleotide polymorphisms (SNPs) from the PON1 (paraoxonase 1) gene influence the ability to metabolize OPs. Objective: Here, we investigated contributions of NOS genes and OP pesticides to PD risk, controlling for PON1 status. Methods: In 357 incident PD cases and 495 population controls, we investigated eight NOS SNPs and interactions with both household and ambient agricultural OP exposures assessed with geographic information system (GIS). Results: In comparing PD in homozygous variant carriers of NOS2A rs1060826 versus homozygous wild-type or heterozygotes, we estimate an adjusted odds ratio (OR) of 1.51 (95% CI: 0.95, 2.41). When considering interactions between NOS1 rs2682826 and OP exposure from household use, the OR for frequent OP use alone was 1.30 (95% CI: 0.72, 2.34) and for the CT+TT genotype alone was 0.89 (95% CI: 0.58, 1.39), and for frequent OP use combined with the CT+TT genotype the OR was 2.84 (95% CI: 1.49, 5.40) (interaction p-value 0.04). Similar results were seen for ambient OP exposure. Interactions between OP exposure and three other NOS1 SNPs and a genetic risk score combining all NOS1 SNPs reached statistical significance. Conclusions: We found that OP pesticides were more strongly associated with PD among participants with variant genotypes in NOS1, consistent with the importance of oxidative stress-inducing mechanisms. Our data provide evidence for NOS1 modifying PD risk in OP exposed populations. Citation: Paul KC, Sinsheimer JS, Rhodes SL, Cockburn M, Bronstein J, Ritz B. 2016. Organophosphate pesticide exposures, nitric oxide synthase gene variants, and gene–pesticide interactions in a case–control study of Parkinson

  14. Developments in alternative treatments for organophosphate poisoning.

    PubMed

    Iyer, Rupa; Iken, Brian; Leon, Alex

    2015-03-01

    Organophosphosphates (OPs) are highly effective acetylcholinesterase (AChE) inhibitors that are used worldwide as cheap, multi-purpose insecticides. OPs are also used as chemical weapons forming the active core of G-series and V-series chemical agents including tabun, sarin, soman, cyclosarin, VX, and their chemical analogs. Human exposure to any of these compounds leads to neurotoxic accumulation of the neurotransmitter acetylcholine, resulting in abnormal nerve function and multiple secondary health complications. Suicide from deliberate exposure to OPs is particularly prevalent in developing countries across the world and constitutes a major global health crisis. The prevalence and accessible nature of OP compounds within modern agricultural spheres and concern over their potential use in biochemical weapon attacks have incentivized both government agencies and medical researchers to enact stricter regulatory policies over their usage and to begin developing more proactive medical treatments in cases of OP poisoning. This review will discuss the research undertaken in recent years that has investigated new supplementary drug options for OP treatment and support therapy, including progress in the development of enzymatic prophylaxis.

  15. Method for the determination of organophosphate insecticides in water, sediment and biota.

    PubMed

    Tse, Hung; Comba, Michael; Alaee, Mehran

    2004-01-01

    A procedure for the determination of 13 organophosphate insecticides (OPs) in water, sediment and biota at low ppb levels is described. Samples were extracted with dichloromethane or acetone/hexane and cleaned up with micro-column silica gel chromatography. Measurements were made by dual capillary column gas chromatography using both nitrogen-phosphorus (NPD) and electron capture (ECD) detection. Recoveries from fortified water samples ranged from 76% to 102% for all sample types. Practical detection limits ranged between 0.003 and 0.029 microg/l in natural water samples, 0.0004-0.005 microg/g w.w. for sediments, and 0.001-0.005 microg/g w.w for biota using the NPD and ECD method. Losses in sediments were experienced when sulphur was removed. Precision and accuracy were not affected in sediment samples where sulphur was not removed.

  16. Cell surface display of organophosphorus hydrolase for sensitive spectrophotometric detection of p-nitrophenol substituted organophosphates.

    PubMed

    Tang, Xiangjiang; Liang, Bo; Yi, Tuyong; Manco, Giuseppe; Palchetti, Ilaria; Ilariapalchetti; Liu, Aihua

    2014-02-01

    Organophosphates (OPs) widely exist in ecosystem as toxic substances, for which sensitive and rapid analytical methods are highly requested. In the present work, by using N-terminal of ice nucleation protein (INP) as anchoring motif, a genetically engineered Escherichia coli (E. coli) strain surface displayed mutant organophosphorus hydrolase (OPH) (S5) with improved enzyme activity was successfully constructed. The surface location of INP-OPH fusion was confirmed by SDS-PAGE analysis and enzyme activity assays. The OPH-displayed bacteria facilitate the hydrolysis of p-nitrophenol (PNP) substituted organophosphates to generate PNP, which can be detected spectrometrically at 410 nm. Over 90% of the recombinant protein present on the surface of microbes demonstrated enhanced enzyme activity and long-term stability. The OPH activity of whole cells was 2.16 U/OD₆₀₀ using paraoxon as its substrate, which is the highest value reported so far. The optimal temperature for OPH activity was around 55 °C, and suspended cultures retained almost 100% of its activity over a period of one month at room temperature, exhibiting the better stability than free OPH. The recombinant E. coli strain could be employed as a whole-cell biocatalyst for detecting PNP substituted OPs at wider ranges and lower detection limits. Specifically, the linear ranges of the calibration curves were 0.5-150 μM paraoxon, 1-200 μM parathion and 2.5-200 μM methyl parathion, and limits of detection were 0.2 μM, 0.4 μM and 1 μM for paraoxon, parathion and methyl parathion, respectively (S/N=3). These results indicate that the engineered OPH strain is a promising multifunctional bacterium that could be used for further large-scale industrial and environmental applications. PMID:24411452

  17. Early-life Exposure to Organophosphate Pesticides and Pediatric Respiratory Symptoms in the CHAMACOS Cohort

    PubMed Central

    Harley, Kim G.; Balmes, John R.; Bradman, Asa; Lipsett, Michael; Eskenazi, Brenda

    2014-01-01

    Background: Although pesticide use is widespread, the possible effect of early-life exposure to organophosphate (OP) on pediatric respiratory health is not well described. Objectives: We investigated the relationship between early-life exposure to OPs and respiratory outcomes. Methods: Participants included 359 mothers and children from the CHAMACOS birth cohort. Dialkyl phosphate (DAP) metabolites of OP pesticides, specifically diethyl (DE) and dimethyl (DM) phosphate metabolites, were measured in urine from mothers twice during pregnancy (mean = 13 and 26 weeks gestation) and from children five times during childhood (0.5–5 years). Childhood DAP concentrations were estimated by the area under curve (AUC). Mothers reported their child’s respiratory symptoms at 5 and 7 years of age. We used generalized estimating equations (GEE) to examine associations of prenatal and childhood DAP concentrations with repeated measures of respiratory symptoms and exercise-induced coughing at 5 and 7 years of age, adjusting for child’s sex and age, maternal smoking during pregnancy, secondhand tobacco smoke, season of birth, PM2.5, breastfeeding, mold and cockroaches in home, and distance from highway. Results: Higher prenatal DAP concentrations, particularly DE, were nonsignificantly associated with respiratory symptoms in the previous 12 months at 5 or 7 years of age [adjusted odds ratio (aOR) per 10-fold increase = 1.44; 95% CI: 0.98, 2.12]. This association was strongest with total DAP and DE from the second half of pregnancy (aOR per 10-fold increase = 1.77; 95% CI: 1.06, 2.95; and 1.61; 95% CI: 1.08, 2.39, respectively). Childhood DAP, DE, and DM concentrations were associated with respiratory symptoms and exercise-induced coughing in the previous 12 months at 5 or 7 years of age (total DAPs: aOR per 10-fold increase = 2.53; 95% CI: 1.32, 4.86; and aOR = 5.40; 95% CI: 2.10, 13.91, respectively). Conclusions: Early-life exposure to OP pesticides was associated with

  18. Organophosphate Hydrolase in Conductometric Biosensor for the Detection of Organophosphate Pesticides.

    PubMed

    Mulyasuryani, Ani; Prasetyawan, Sasangka

    2015-01-01

    The research has developed an enzyme biosensor for the detection organophosphate pesticide residues. The biosensor consists of a pair of screen-printed carbon electrode (SPCEs). One of electrodes contains immobilized organophosphate hydrolase (OPH) on a chitosan membrane by cross-linking it with glutaraldehyde. The area of the electrodes was optimized to 3, 5, and 7 mm(2). The OPH was isolated from Pseudomonas putida, and was purified by the ammonium sulfate precipitation method, with 6444 ppm (A) and 7865 ppm (B). The organophosphate pesticide samples were 0-100 ppb in tris-acetate buffer 0.05 M, pH 8.5. The results showed that the best performance of the biosensor was achieved by the enzyme A with an electrode area of 5 mm(2). The sensitivity of the biosensor was between 3 and 32 µS/ppb, and the detection limit for the organophosphate pesticides was 40 ppb (diazinon), 30 ppb (malathion), 20 ppb (chlorpyrifos), and 40 ppm (profenofos). PMID:26483607

  19. Organophosphate Hydrolase in Conductometric Biosensor for the Detection of Organophosphate Pesticides

    PubMed Central

    Mulyasuryani, Ani; Prasetyawan, Sasangka

    2015-01-01

    The research has developed an enzyme biosensor for the detection organophosphate pesticide residues. The biosensor consists of a pair of screen-printed carbon electrode (SPCEs). One of electrodes contains immobilized organophosphate hydrolase (OPH) on a chitosan membrane by cross-linking it with glutaraldehyde. The area of the electrodes was optimized to 3, 5, and 7 mm2. The OPH was isolated from Pseudomonas putida, and was purified by the ammonium sulfate precipitation method, with 6444 ppm (A) and 7865 ppm (B). The organophosphate pesticide samples were 0–100 ppb in tris-acetate buffer 0.05 M, pH 8.5. The results showed that the best performance of the biosensor was achieved by the enzyme A with an electrode area of 5 mm2. The sensitivity of the biosensor was between 3 and 32 µS/ppb, and the detection limit for the organophosphate pesticides was 40 ppb (diazinon), 30 ppb (malathion), 20 ppb (chlorpyrifos), and 40 ppm (profenofos). PMID:26483607

  20. ANDROGEN RECEPTOR ANTAGONISM BY THE ORGANOPHOSPHATE INSECTICIDE FENITROTHION

    EPA Science Inventory

    Androgen receptor antagonism by the organophosphate insecticide fenitrothion. Tamura, H., Maness, S.C., Reischmann, K. Dorman, D.C., Gray, L.E., and Gaido, K.W. (2000). Toxicol. Sci.

    Organophosphate insecticides represent one of the most widely used classes of pesticide...

  1. Sensitivity of nestling and adult starlings to dicrotophos, an organophosphate pesticide

    USGS Publications Warehouse

    Grue, C.E.; Shipley, B.K.

    1984-01-01

    The 24-hr median lethal dose (LD50) of dicrotophos (3-hydroxy-N,N-dimethyl-cis-crotonamide dimethyl phosphate) for free-living 5-day-old nestling European starlings (Sturnus vulgaris, LDso = 4.92 mg/kg body wt) was about one-half that obtained for free-living 15day-old nestlings (9.59 mg/kg) and captive adult males (8.37 mg/kg) and females (8.47 mg/ kg). Nestlings and adults with low pretreatment body weights appeared to be more vulnerable to organophosphate (OP) exposure. Brain cholinesterase (ChE) activity was severely depressed in all birds that died (74-94%); the degree of inhibition did not vary with age or sex. Inhibition of brain ChE in 5-day-old nestlings alive 24 hr post dose (X = 28-43%) was lower than that of 15-day-old (X = 55-68%) and adult (X = 55-77%) survivors. Body weights of OP-dosed birds that died were depressed an average of 20 to 46% in 5-day-olds, 7 to 20% in 15-day-olds, and 0 to 10% in adults; weight losses varied inversely with age and dosage, and directly with time to death. Average weight losses in 5- and 15-day-old survivors (X < 31 and 26%, respectively) varied directly with dose and exceeded comparable values for adults (X = 3-15%). Results suggest that (1) young nestling songbirds may be nearly twice as sensitive as adults to OPs, (2) growth of nestlings may be severely depressed following OP exposure, and (3) recovery of brain ChE activity following exposure to ChE inhibitors may be more rapid in nestlings than adults.

  2. Mechanism behind Resistance against the Organophosphate Azamethiphos in Salmon Lice (Lepeophtheirus salmonis).

    PubMed

    Kaur, Kiranpreet; Helgesen, Kari Olli; Bakke, Marit Jørgensen; Horsberg, Tor Einar

    2015-01-01

    Acetylcholinesterase (AChE) is the primary target for organophosphates (OP). Several mutations have been reported in AChE to be associated with the reduced sensitivity against OP in various arthropods. However, to the best of our knowledge, no such reports are available for Lepeophtheirus salmonis. Hence, in the present study, we aimed to determine the association of AChE(s) gene(s) with resistance against OP. We screened the AChE genes (L. salmonis ace1a and ace1b) in two salmon lice populations: one sensitive (n=5) and the other resistant (n=5) for azamethiphos, a commonly used OP in salmon farming. The screening led to the identification of a missense mutation Phe362Tyr in L. salmonis ace1a, (corresponding to Phe331 in Torpedo californica AChE) in all the samples of the resistant population. We confirmed the potential role of the mutation, with reduced sensitivity against azamethiphos in L. salmonis, by screening for Phe362Tyr in 2 sensitive and 5 resistant strains. The significantly higher frequency of the mutant allele (362Tyr) in the resistant strains clearly indicated the possible association of Phe362Tyr mutation in L. salmonis ace1a with resistance towards azamethiphos. The 3D modelling, short term survival experiments and enzymatic assays further supported the imperative role of Phe362Tyr in reduced sensitivity of L. salmonis for azamethiphos. Based on all these observations, the present study, for the first time, presents the mechanism of resistance in L. salmonis against azamethiphos. In addition, we developed a rapid diagnostic tool for the high throughput screening of Phe362Tyr mutation using High Resolution Melt analysis. PMID:25893248

  3. Occupational determinants of serum cholinesterase inhibition among organophosphate-exposed agricultural pesticide handlers in Washington State

    PubMed Central

    Hofmann, Jonathan N; Keifer, Matthew C; De Roos, Anneclaire J; Fenske, Richard A; Furlong, Clement E; van Belle, Gerald; Checkoway, Harvey

    2010-01-01

    Objective To identify potential risk factors for serum cholinesterase (BuChE) inhibition among agricultural pesticide handlers exposed to organophosphate (OP) and N-methyl-carbamate (CB) insecticides. Methods We conducted a longitudinal study among 154 agricultural pesticide handlers who participated in the Washington State cholinesterase monitoring program in 2006 and 2007. BuChE inhibition was analyzed in relation to reported exposures before and after adjustment for potential confounders using linear regression. Odds ratios estimating the risk of ‘BuChE depression’ (>20% from baseline) were also calculated for selected exposures based on unconditional logistic regression analyses. Results An overall decrease in mean BuChE activity was observed among study participants at the time of follow-up testing during the OP/CB spray season relative to pre-season baseline levels (mean decrease of 5.6%, P < 0.001). Score for estimated cumulative exposure to OP/CB insecticides in the past 30 days was a significant predictor of BuChE inhibition (β = −1.74, P < 0.001). Several specific work practices and workplace conditions were associated with greater BuChE inhibition, including mixing/loading pesticides and cleaning spray equipment. Factors that were protective against BuChE inhibition included full-face respirator use, wearing chemical-resistant boots, and storing personal protective equipment in a locker at work. Conclusions Despite existing regulations, agricultural pesticide handlers continue to be exposed to OP/CB insecticides at levels resulting in BuChE inhibition. These findings suggest that modifying certain work practices could potentially reduce BuChE inhibition. Replication from other studies will be valuable. PMID:19819864

  4. Exposure of Preschool-Age Greek Children (RHEA Cohort) to Bisphenol A, Parabens, Phthalates, and Organophosphates.

    PubMed

    Myridakis, Antonis; Chalkiadaki, Georgia; Fotou, Marianna; Kogevinas, Manolis; Chatzi, Leda; Stephanou, Euripides G

    2016-01-19

    Phthalate esters (PEs), bisphenol A (BPA), and parabens (PBs), which are used in numerous consumer products, are known for their endocrine disrupting properties. Organophosphate chemicals (OPs), which form the basis of the majority of pesticides, are known for their neurotoxic activity in humans. All of these chemicals are associated with health problems to which children are more susceptible. Once they enter the human body, PEs, BPA, PBs, and OPs are metabolized and/or conjugated and finally excreted via urine. Hence, human exposure to these substances is examined through a determination of the urinary concentrations of their metabolites. This study assessed the exposure of Greek preschool-age children to PEs, BPA, PBs, and OPs by investigating the urinary levels of seven PEs metabolites, six PBs, BPA, and six dialkyl phosphate metabolites in five-hundred samples collected from 4-year-old children, subjects of the "RHEA" mother-child cohort in Crete, Greece. Daily intake of endocrine disruptors, calculated for 4 year old children, was lower than the corresponding daily intake for 2.5 year old children, which were determined in an earlier study of the same cohort. In some cases the daily intake levels exceeded the U.S. Environmental Protection Agency Tolerable Daily Intake (TDI) values and the EFSA Reference Doses (RfD) (e.g., for di-2-ethyl-hexyl phthalate, 3.6% and 1% of the children exceeded RfD and TDi, respectively). Exposure was linked to three main sources: PEs-BPA to plastic, PBs-diethyl phthalate to personal hygiene products, and OPs to food. PMID:26654094

  5. Exposure of Preschool-Age Greek Children (RHEA Cohort) to Bisphenol A, Parabens, Phthalates, and Organophosphates.

    PubMed

    Myridakis, Antonis; Chalkiadaki, Georgia; Fotou, Marianna; Kogevinas, Manolis; Chatzi, Leda; Stephanou, Euripides G

    2016-01-19

    Phthalate esters (PEs), bisphenol A (BPA), and parabens (PBs), which are used in numerous consumer products, are known for their endocrine disrupting properties. Organophosphate chemicals (OPs), which form the basis of the majority of pesticides, are known for their neurotoxic activity in humans. All of these chemicals are associated with health problems to which children are more susceptible. Once they enter the human body, PEs, BPA, PBs, and OPs are metabolized and/or conjugated and finally excreted via urine. Hence, human exposure to these substances is examined through a determination of the urinary concentrations of their metabolites. This study assessed the exposure of Greek preschool-age children to PEs, BPA, PBs, and OPs by investigating the urinary levels of seven PEs metabolites, six PBs, BPA, and six dialkyl phosphate metabolites in five-hundred samples collected from 4-year-old children, subjects of the "RHEA" mother-child cohort in Crete, Greece. Daily intake of endocrine disruptors, calculated for 4 year old children, was lower than the corresponding daily intake for 2.5 year old children, which were determined in an earlier study of the same cohort. In some cases the daily intake levels exceeded the U.S. Environmental Protection Agency Tolerable Daily Intake (TDI) values and the EFSA Reference Doses (RfD) (e.g., for di-2-ethyl-hexyl phthalate, 3.6% and 1% of the children exceeded RfD and TDi, respectively). Exposure was linked to three main sources: PEs-BPA to plastic, PBs-diethyl phthalate to personal hygiene products, and OPs to food.

  6. Mechanism behind Resistance against the Organophosphate Azamethiphos in Salmon Lice (Lepeophtheirus salmonis)

    PubMed Central

    Kaur, Kiranpreet; Helgesen, Kari Olli; Bakke, Marit Jørgensen; Horsberg, Tor Einar

    2015-01-01

    Acetylcholinesterase (AChE) is the primary target for organophosphates (OP). Several mutations have been reported in AChE to be associated with the reduced sensitivity against OP in various arthropods. However, to the best of our knowledge, no such reports are available for Lepeophtheirus salmonis. Hence, in the present study, we aimed to determine the association of AChE(s) gene(s) with resistance against OP. We screened the AChE genes (L. salmonis ace1a and ace1b) in two salmon lice populations: one sensitive (n=5) and the other resistant (n=5) for azamethiphos, a commonly used OP in salmon farming. The screening led to the identification of a missense mutation Phe362Tyr in L. salmonis ace1a, (corresponding to Phe331 in Torpedo californica AChE) in all the samples of the resistant population. We confirmed the potential role of the mutation, with reduced sensitivity against azamethiphos in L. salmonis, by screening for Phe362Tyr in 2 sensitive and 5 resistant strains. The significantly higher frequency of the mutant allele (362Tyr) in the resistant strains clearly indicated the possible association of Phe362Tyr mutation in L. salmonis ace1a with resistance towards azamethiphos. The 3D modelling, short term survival experiments and enzymatic assays further supported the imperative role of Phe362Tyr in reduced sensitivity of L. salmonis for azamethiphos. Based on all these observations, the present study, for the first time, presents the mechanism of resistance in L. salmonis against azamethiphos. In addition, we developed a rapid diagnostic tool for the high throughput screening of Phe362Tyr mutation using High Resolution Melt analysis. PMID:25893248

  7. Nanoparticle-Based Electrochemical Immunosensor for the Detection of Phosphorylated Acetylcholinesterase: An Exposure Biomarker of Organophosphate Pesticides and Nerve AgentsOrganophosphate Pesticides and Nerve Agents

    SciTech Connect

    Liu, Guodong; Wang, Jun; Barry, Richard C.; Petersen, Catherine E.; Timchalk, Charles; Gassman, Paul L.; Lin, Yuehe

    2008-11-01

    A nanoparticle-based electrochemical immunosensor has been developed for the detection of phosphorylated acetylcholinesterase (AChE) adducts, which is a potential exposure biomarker for organophosphate pesticides (OP) and chemical warfare nerve agent exposures. Zirconia nanoparticles (ZrO2 NPs) were used as selective sorbents to capture the phosphorylated AChE adduct, and quantum dots (ZnS@CdS, QDs) were used as tags to label monoclonal anti-AChE antibody to track the immunorecognition events. The sandwich-like immunoreactions were performed among the ZrO2 NPs, which were pre-coated on a screen printed electrode (SPE) by electrodeposition, phosphorylated AChE and QD-anti-AChE. The captured QD tags were determined on the SPE by electrochemical stripping analysis of its metallic component (cadmium) after an acid-dissolution step. Paraoxon was used as a model OP insecticide to prepare the phosphorylated AChE adduct to demonstrate the proof of principle for this sensor technology. The paraoxon-AChE adduct was characterized by Fourier Transform Infrared Spectrum, and the binding affinity of anti-AChE to the paraoxon-AChE was validated with an enzyme-linked immunosorbent assay. The parameters (e.g., amount of ZrO2 NP, QD-anti-AChE concentration,) that govern the electrochemical response of immunosensors were optimized. The voltammetric response of the immunosensor is highly linear over the range of 10 pM to 4 nM paraoxon-AChE, and the limit of detection is estimated to be 8 pM. This new nanoparticle-based electrochemical immunosensor thus provides a sensitive and quantitative tool for biomonitoring exposure to OP pesticides and nerve agents.

  8. Detoxification of organophosphate nerve agents by bacterial phosphotriesterase

    SciTech Connect

    Ghanem, Eman; Raushel, Frank M. . E-mail: raushel@tamu.edu

    2005-09-01

    Organophosphates have been widely used as insecticides and chemical warfare agents. The health risks associated with these agents have necessitated the need for better detoxification and bioremediation tools. Bacterial enzymes capable of hydrolyzing the lethal organophosphate nerve agents are of special interest. Phosphotriesterase (PTE) isolated from the soil bacteria Pseudomonas diminuta displays a significant rate enhancement and substrate promiscuity for the hydrolysis of organophosphate triesters. Directed evolution and rational redesign of the active site of PTE have led to the identification of new variants with enhanced catalytic efficiency and stereoselectivity toward the hydrolysis of organophosphate neurotoxins. PTE has been utilized to protect against organophosphate poisoning in vivo. Biotechnological applications of PTE for detection and decontamination of insecticides and chemical warfare agents are developing into useful tools. In this review, the catalytic properties and potential applications of this remarkable enzyme are discussed.

  9. Organophosphates induce distal axonal damage, but not brain oedema, by inactivating neuropathy target esterase

    SciTech Connect

    Read, David J.; Li Yong; Chao, Moses V.; Cavanagh, John B.; Glynn, Paul

    2010-05-15

    Single doses of organophosphorus compounds (OP) which covalently inhibit neuropathy target esterase (NTE) can induce lower-limb paralysis and distal damage in long nerve axons. Clinical signs of neuropathy are evident 3 weeks post-OP dose in humans, cats and chickens. By contrast, clinical neuropathy in mice following acute dosing with OPs or any other toxic compound has never been reported. Moreover, dosing mice with ethyloctylphosphonofluoridate (EOPF) - an extremely potent NTE inhibitor - causes a different (subacute) neurotoxicity with brain oedema. These observations have raised the possibility that mice are intrinsically resistant to neuropathies induced by acute toxic insult, but may incur brain oedema, rather than distal axonal damage, when NTE is inactivated. Here we provide the first report that hind-limb dysfunction and extensive axonal damage can occur in mice 3 weeks after acute dosing with a toxic compound, bromophenylacetylurea. Three weeks after acutely dosing mice with neuropathic OPs no clinical signs were observed, but distal lesions were present in the longest spinal sensory axons. Similar lesions were evident in undosed nestin-cre:NTEfl/fl mice in which NTE had been genetically-deleted from neural tissue. The extent of OP-induced axonal damage in mice was related to the duration of NTE inactivation and, as reported in chickens, was promoted by post-dosing with phenylmethanesulfonylfluoride. However, phenyldipentylphosphinate, another promoting compound in chickens, itself induced in mice lesions different from the neuropathic OP type. Finally, EOPF induced subacute neurotoxicity with brain oedema in both wild-type and nestin-cre:NTEfl/fl mice indicating that the molecular target for this effect is not neural NTE.

  10. Organophosphate pesticide exposure in school-aged children living in rice and aquacultural farming regions of Thailand.

    PubMed

    Rohitrattana, Juthasiri; Siriwong, Wattasit; Tunsaringkarn, Tanasorn; Panuwet, Parinya; Ryan, P Barry; Barr, Dana Boyd; Robson, Mark G; Fiedler, Nancy

    2014-01-01

    Organophosphate pesticides (OPs) are widely used in agricultural sectors in Thailand. Previous studies have documented that children residing in agricultural areas have higher exposure to OPs than children living in other residential areas. The objective of this study was to quantify urinary biomarkers of OP exposure and determine the environmental conditions and activities that predict their levels among children living in Central Thailand farming regions. In October 2011, 53 6-8-year-old participants were recruited from Pathum Thani Province, Thailand. Twenty-four lived in rice farming communities at Khlong Luang District where OPs are the pesticides used frequently. Twenty-nine participants, living in aquacultural farming communities at Lum Luk Ka District where OPs are not used, were recruited to serve as controls for pathways of exposure (e.g., residential, dietary) other than occupational/paraoccupational exposures encountered in rice farming. Household environments and participants' activities were assessed using a parental structured interview. Urine samples (first morning voids) were collected from participants for OP urinary metabolite (i.e., dialkylphosphates [DAPs] and 3,5,6-trichloro-2-pyridinol [TCPy]) measurements. The levels of most urinary OP metabolites were significantly higher in participants who lived in a rice farming community than those who lived in an aquacultural farming community (P < .05). The results from linear regression analysis revealed that the frequency of OP application on rice farms (∑DAP: P = .001; TCPy: P = .001) and living in a rice farming community (∑DAP: P = .009; TCPy: P < .001) were significant predictors of urinary DAP metabolite levels in participants. Increasing TCPy levels were significantly related to proximity to rice farm (P = .03), being with parent while working on a farm (P = .02), playing on a farm (P = .03), and the presence of observable dirt accumulated on the child's body (P = .02). In conclusion, OP

  11. Determination of organophosphate diesters in urine samples by a high-sensitivity method based on ultra high pressure liquid chromatography-triple quadrupole-mass spectrometry.

    PubMed

    Su, Guanyong; Letcher, Robert J; Yu, Hongxia

    2015-12-24

    Organophosphate (OP) diesters in urine samples have potential use as biomarkers of organism exposure to environmentally relevant OP triester precursors and in particular OP triester flame retardants. This present study developed a quantitatively sensitive ultra high pressure liquid chromatography (UHPLC-MS) based method for urine and the determination of OP diesters (i.e. diphenyl phosphate (DPHP), bis(2-chloroethyl) phosphate (BCEP), bis(2-chloroisopropyl) phosphate (BDCIPP), di-n-butyl phosphate (DNBP), di(2-ethylhexyl) phosphate (DEHP), bis(1-chloro-2-propyl) phosphate (BCIPP), and bis(2-butoxyethyl) phosphate (BBOEP)). Fortified with the 7 OP diesters, 1mL of human urine sample was cleaned up using weak anion exchange solid phase extraction and eluted with high ionic strength ammonium acetate buffer. Subsequently, 4 non-chlorinated OP diesters were directly determined using UHPLC-electrospray(-)-triple quadrupole-MS (UHPLC-ESI(-)-QqQ-MS), and UHPLC-ESI(+)-QqQ-MS was used for determination of 3 chlorinated OP diesters after methylation using diazomethane. Recovery efficiencies of OP diesters ranged from 88 to 160% at three spiking levels (0.4, 2 and 10ng/mL urine). Matrix effects (MEs) and method limits of quantification (MLOQs) were 15-134% and 0.10-0.32ng/mL urine, respectively. Concentrations of OP diesters in n=12 urine samples (from 4 Canadian residents, 2014) varied as follows, nd-<0.28 (DNBP), nd-1.29 (DPHP), nd-<0.28 (DEHP), <0.16-12.33 (BCEP), nd-1.17 (BCDIPP) and nd-0.68ng/mL (BCIPP).

  12. A mechanism-based 3D-QSAR approach for classification and prediction of acetylcholinesterase inhibitory potency of organophosphate and carbamate analogs.

    PubMed

    Lee, Sehan; Barron, Mace G

    2016-04-01

    Organophosphate (OP) and carbamate esters can inhibit acetylcholinesterase (AChE) by binding covalently to a serine residue in the enzyme active site, and their inhibitory potency depends largely on affinity for the enzyme and the reactivity of the ester. Despite this understanding, there has been no mechanism-based in silico approach for classification and prediction of the inhibitory potency of ether OPs or carbamates. This prompted us to develop a three dimensional prediction framework for OPs, carbamates, and their analogs. Inhibitory structures of a compound that can form the covalent bond were identified through analysis of docked conformations of the compound and its metabolites. Inhibitory potencies of the selected structures were then predicted using a previously developed three dimensional quantitative structure-active relationship. This approach was validated with a large number of structurally diverse OP and carbamate compounds encompassing widely used insecticides and structural analogs including OP flame retardants and thio- and dithiocarbamate pesticides. The modeling revealed that: (1) in addition to classical OP metabolic activation, the toxicity of carbamate compounds can be dependent on biotransformation, (2) OP and carbamate analogs such as OP flame retardants and thiocarbamate herbicides can act as AChEI, (3) hydrogen bonds at the oxyanion hole is critical for AChE inhibition through the covalent bond, and (4) π-π interaction with Trp86 is necessary for strong inhibition of AChE. Our combined computation approach provided detailed understanding of the mechanism of action of OP and carbamate compounds and may be useful for screening a diversity of chemical structures for AChE inhibitory potency. PMID:27055524

  13. Effects of organophosphate and carbamate pesticides on acetylcholinesterase and choline acetyltransferase activities of the polychaete Nereis diversicolor.

    PubMed

    Scaps, P; Demuynck, S; Descamps, M; Dhainaut, A

    1997-08-01

    A toxicity test for organophosphates (OP) and carbamates (C) was improved with the adult ragworm Nereis diversicolor. Animals were maintained in U-shaped glass tubes of 4-mm inner diameter fixed vertically on a plastic plate and placed in glass aquaria. Each tank was covered with glass in order to reduce evaporation and heat dissipation. Temperature varied between 15 and 16 degrees C and salinity was constant (34 per thousand) during the entire length of the experiment. Experiments were performed with a fixed day length of 12 h and seawater was gently aerated. The maintenance system allowed the administration of OP and C compounds via the seawater. An acclimatization period of 48 h was not sufficient to accomodate worms to their artificial burrows; accordingly, we chose to acclimate worms for a week before beginning the exposure. Choline acetyltransferase (ChAT) activity was very low and was not significantly modified by two OP compounds: malathion and parathion-ethyl. ChAT is not a target for these pesticides and should not be used for future studies about OP and C toxicity. On the other hand, inhibitory effects on acetylcholinesterase (AChE) activity were determined at concentrations of 10(-6) M for three OP compounds-malathion, parathion-ethyl, and phosalone-and a carbamate pesticide-carbaryl. We measured only short-term effects and no cumulative effect was determined, the maximum percentage of AChE activity inhibition being between 2 (carbaryl) and 7 (OP compounds) days after exposure and then remaining stable. Mortality occured only after a period of intoxication of 14 days. N diversicolor, which can be easily maintained at the laboratory, seems to be a good candidate for future laboratory studies to test the toxicity of other pollutants.

  14. Quaternary and tertiary aldoxime antidotes for organophosphate exposure in a zebrafish model system

    SciTech Connect

    Schmidt, Hayden R.; Radić, Zoran; Taylor, Palmer; Fradinger, Erica A.

    2015-04-15

    The zebrafish is rapidly becoming an important model system for screening of new therapeutics. Here we evaluated the zebrafish as a potential pharmacological model for screening novel oxime antidotes to organophosphate (OP)-inhibited acetylcholinesterase (AChE). The k{sub i} values determined for chlorpyrifos oxon (CPO) and dichlorvos (DDVP) showed that CPO was a more potent inhibitor of both human and zebrafish AChE, but overall zebrafish AChE was less sensitive to OP inhibition. In contrast, aldoxime antidotes, the quaternary ammonium 2-PAM and tertiary amine RS-194B, showed generally similar overall reactivation kinetics, k{sub r}, in both zebrafish and human AChE. However, differences between the K{sub ox} and k{sub 2} constants suggest that zebrafish AChE associates more tightly with oximes, but has a slower maximal reactivation rate than human AChE. Homology modeling suggests that these kinetic differences result from divergences in the amino acids lining the entrance to the active site gorge. Although 2-PAM had the more favorable in vitro reactivation kinetics, RS-194B was more effective antidote in vivo. In intact zebrafish embryos, antidotal treatment with RS-194B rescued embryos from OP toxicity, whereas 2-PAM had no effect. Dechorionation of the embryos prior to antidotal treatment allowed both 2-PAM and RS-194B to rescue zebrafish embryos from OP toxicity. Interestingly, RS-194B and 2-PAM alone increased cholinergic motor activity in dechorionated embryos possibly due to the reversible inhibition kinetics, K{sub i} and αK{sub i}, of the oximes. Together these results demonstrate that the zebrafish at various developmental stages provides an excellent model for investigating membrane penetrant antidotes to OP exposure. - Highlights: • Zebrafish AChE shares significant structural similarities with human AChE. • OP-inhibited zebrafish and human AChE exhibit similar reactivation kinetics. • The zebrafish chorion is permeable to BBB penetrant and not

  15. Development of enzyme-based biosensors for the detection of organophosphate neurotoxins

    NASA Astrophysics Data System (ADS)

    Paliwal, Sheetal

    Elevated concerns of ecological safety and environmental pollution have facilitated massive research in the area of chemical and biological agent detection. Large numbers of anthropogenic chemicals were introduced in the environment within last 50 years, which posed a serious threat to the natural ecological balance. The series of unfortunate events in the past could have been avoided or minimized by the availability of adequately selective and sensitive detectors, capable of discriminating between common use pesticides and chemical warfare agents. Organophosphates (OPs) in particular are more of a concern because of their toxicity and inhibition of esterase enzymes which are involved in nerve transmission. They have been an integral part of agricultural industry for past decades owing to their specificity. In addition, to their wide usage, they have also been exploited for the development of chemical warfare agents. Consequently, there is an emergent need for rapid and sensitive detection methods. Enzyme-based studies have been investigated in an effort to develop simple, rapid, user-friendly and sensitive detection of OPs. The methods described have been developed using OPH, an enzyme capable of hydrolyzing OPs. A rapid detection method using a fiber-optic waveguide and a portable fluorimeter Analyte 2000 was developed. Immobilization of OPH was accomplished using avidin-biotin chemistry. Change in fluorescence intensity was observed upon hydrolysis of substrate by OPH, concentration as low as 0.05 muM paraoxon (PX) was qualitatively measured. A novel detection method for p-nitrophenol and p-nitrophenyl substituent OPs based on fluorescence quenching of coumarin1, a dye similar in structure to some OPs have also been developed. Decrease in fluorescence intensity of coumarin1 was proportional to paraoxon concentration in the range of 0.7--170 muM. To preserve OPH activity and stability, encapsulation using lysozyme-mediated silica nanoparticles was accomplished

  16. Differentiation between organophosphate and carbamate poisoning.

    PubMed

    Rotenberg, M; Shefi, M; Dany, S; Dore, I; Tirosh, M; Almog, S

    1995-01-31

    We propose a novel and simple assay for the real-time differentiation between carbamate and organophosphate inhibition of cholinesterase, based on our observations of the kinetic behavior of inhibited enzyme. The assay of carbamylated cholinesterase activity over time follows a non-linear kinetic pattern, whereas that of phosphorylated enzyme activity is linear. This feature can be exploited to differentiate between carbamate and organophosphate cholinesterase inhibition. The non-linear pattern characteristic of carbamates is easily discernible at degrees of inhibition of 40% or more. In this setting, cholinesterase activity ought to be measured continuously for about 1 h to obtain the kinetic pattern of enzyme activity. The initial activity, measured during the first 5 min of assay, represents the activity of enzyme in vivo. In vitro reactivation of inhibited cholinesterase allows the estimation of full potential activity of enzyme prior to poisoning, so that percentage of inhibition can be calculated. Reactivation of carbamylated cholinesterase is obtained by the incubation of diluted enzyme at 37 degrees C for 2.5 h prior to assay, whereas phosphorylated (non-aged) enzyme is reactivated by a 30 min incubation with oximes. In cases of mild exposure to cholinesterase inhibitors (< 40% inhibition), the response of enzyme to in vitro reactivation serves as a complementary test for exposure and for the nature of the inhibitor. All the results presented in this work refer to plasma cholinesterase. Erythrocyte cholinesterase was found to behave very similarly to plasma enzyme and its results have not been reported here.

  17. Functional Consequences of Repeated Organophosphate Exposure: Potential Non-Cholinergic Mechanisms

    PubMed Central

    Terry, A.V.

    2012-01-01

    The class of chemicals known as the “organophosphates” (OPs) comprises many of the most common agricultural and commercial pesticides that are used worldwide as well as the highly toxic chemical warfare agents. The mechanism of the acute toxicity of OPs in both target and non-target organisms is primarily attributed to inhibitory actions on various forms of cholinesterase leading to excessive peripheral and central cholinergic activity. However, there is now substantial evidence that this canonical (cholinesterase-based) mechanism cannot alone account for the wide-variety of adverse consequences of OP exposure that have been described, especially those associated with repeated exposures to levels that produce no overt signs of acute toxicity. This type of exposure has been associated with prolonged impairments in attention, memory, and other domains of cognition, as well as chronic illnesses where these symptoms are manifested (e.g., Gulf War Illness, Alzheimer’s disease). Due to their highly reactive nature, it is not surprising that OPs might alter the function of a number of enzymes and proteins (in addition to cholinesterase). However, the wide variety of long-term neuropsychiatric symptoms that have been associated with OPs suggests that some basic or fundamental neuronal process was adversely affected during the exposure period. The purpose of this review is to discuss several non-cholinesterase targets of OPs that might affect such fundamental processes and includes cytoskeletal and motor proteins involved in axonal transport, neurotrophins and their receptors, and mitochondria (especially their morphology and movement in axons). Potential therapeutic implications of these OP interactions are also discussed. PMID:22465060

  18. Efficacy of the bone injection gun in the treatment of organophosphate poisoning.

    PubMed

    Eisenkraft, Arik; Gilat, Eran; Chapman, Shira; Baranes, Shlomo; Egoz, Inbal; Levy, Aharon

    2007-04-01

    Immediate administration of antidotal treatment is crucial in severe organophosphate (OP) poisoning and the use of an open intravenous (i.v.) line might also be required. The state of casualties might prevent getting access to their veins. The bone injection gun (BIG) was established as a simple method for introducing an intraosseous (i.o.) line and could be applied while wearing a protective suit. The present study followed the pharmacokinetics of the anticonvulsive drug midazolam after i.o. administration in pigs compared with i.v. and the common intramuscular (i.m.) administration. A new method for monitoring midazolam concentrations in plasma was developed. Plasma concentrations following both i.v. and i.o. administrations peaked at 2 min post injection and only at 10 min following the i.m. route. In an antidotal treatment study against paraoxone poisoning, the anticonvulsive effect of midazolam appeared immediately following i.o. administration, while it took 5-10 min to exhibit a similar effect following i.m. administration. This study indicates that the use of i.o. administration after OP poisoning might provide the necessary fast response for rapid termination of convulsions. The BIG might offer a convenient method for treating casualties in the chemical arena by teams wearing full protective gear.

  19. A screen-printed, amperometric biosensor array incorporated into a novel automated system for the simultaneous determination of organophosphate pesticides.

    PubMed

    Crew, A; Lonsdale, D; Byrd, N; Pittson, R; Hart, J P

    2011-02-15

    Organophosphate pesticides present serious risks to human and environmental health. A rapid reliable, economical and portable analytical system will be of great benefit in the detection and prevention of contamination. A biosensor array based on six acetylcholinesterase enzymes for use in a novel automated instrument incorporating a neural network program is described. Electrochemical analysis was carried out using chronoamperometry and the measurement was taken 10s after applying a potential of 0 V vs. Ag/AgCl. The total analysis time for the complete assay was less than 6 min. The array was used to produce calibration data with six organophosphate pesticides (OPs) in the concentration range of 10(-5) M to 10(-9) M to train a neural network. The output of the neural network was subsequently evaluated using different sample matrices. There were no detrimental matrix effects observed from water, phosphate buffer, food or vegetable extracts. Furthermore, the sensor system was not detrimentally affected by the contents of water samples taken from each stage of the water treatment process. The biosensor system successfully identified and quantified all samples where an OP was present in water, food and vegetable extracts containing different OPs. There were no false positives or false negatives observed during the evaluation of the analytical system. The biosensor arrays and automated instrument were evaluated in situ in field experiments where the instrument was successfully applied to the analysis of a range of environmental samples. It is envisaged that the analytical system could provide a rapid detection system for the early warning of contamination in water and food.

  20. A systematic review of the influence of occupational organophosphate pesticides exposure on neurological impairment

    PubMed Central

    Takahashi, Noriko; Hashizume, Masahiro

    2014-01-01

    Objective The aim of this study was to conduct a systematic review of the published literature and to estimate whether or not there is a causal relationship between occupational exposure to organophosphate pesticides (OPs) and either neurological impairment or depressive symptoms. Data sources EMBASE, MEDLINE, Global Health and PsycINFO (1980 to April 2014). Setting Observational studies (cross-sectional, cohort and case–control studies) with exposed and unexposed groups. Participants People who occupationally use OPs for more than 1 month and their family. Primary outcome Results of neurological core test batteries or depressive symptoms such as headaches, anxiety and dizziness. Study appraisal and synthesis methods After an extensive search of various literature databases, one author screened titles and abstracts, searched the relevant publications manually and conducted data extraction. All extracted data from the selected articles were synthesised for analysis. Quality appraisal was conducted using the Newcastle Ottawa Scale. Results Of the 1024 articles retrieved by database search, 24 studies that met the inclusion and exclusion criteria were selected for analysis. Of the selected studies, 17 were cross-sectional and the remaining 7 were cohort and nested case–control studies. The geographical areas included in the studies were the USA (10 studies), the UK (4 studies), Africa (4 studies), Asia (3 studies), Europe (2 studies) and South America (1 study). Each of the included studies used different exposure and outcome assessments such as neurological scores and depressive symptoms, making it difficult to compare the results exactly. Most studies showed that exposed groups had poorer results than unexposed groups; however, owing to the inconsistent neurological test batteries, there was not enough pooling evidence to conduct a meta-analysis. Conclusions The findings of this literature review indicate that it is necessary to standardise the neurological or

  1. Altered GPI modification of insect AChE improves tolerance to organophosphate insecticides.

    PubMed

    Kakani, Evdoxia G; Bon, Suzanne; Massoulié, Jean; Mathiopoulos, Kostas D

    2011-03-01

    The olive fruit fly Bactrocera oleae is the most destructive and intractable pest of olives. The management of B. oleae has been based on the use of organophosphate (OP) insecticides, a practice that induced resistance. OP-resistance in the olive fly was previously shown to be associated with two mutations in the acetylcholinesterase (AChE) enzyme that, apparently, hinder the entrance of the OP into the active site. The search for additional mutations in the ace gene that encodes AChE revealed a short deletion of three glutamines (Δ3Q) from a stretch of five glutamines, in the C-terminal peptide that is normally cleaved and substituted by a GPI anchor. We verified that AChEs from B. oleae and other Dipterans are actually GPI-anchored, although this is not predicted by the "big-PI" algorithm. The Δ3Q mutation shortens the unusually long hydrophilic spacer that follows the predicted GPI attachment site and may thus improve the efficiency of GPI anchor addition. We expressed the wild type B. oleae AChE, the natural mutant Δ3Q and a constructed mutant lacking all 5 consecutive glutamines (Δ5Q) in COS cells and compared their kinetic properties. All constructs presented identical K(m) and k(cat) values, in agreement with the fact that the mutations did not affect the catalytic domain of the enzyme. In contrast, the mutants produced higher AChE activity, suggesting that a higher proportion of the precursor protein becomes GPI-anchored. An increase in the number of GPI-anchored molecules in the synaptic cleft may reduce the sensitivity to insecticides.

  2. Prenatal Exposure to Organophosphate Pesticides and IQ in 7-Year-Old Children

    PubMed Central

    Bouchard, Maryse F.; Chevrier, Jonathan; Harley, Kim G.; Kogut, Katherine; Vedar, Michelle; Calderon, Norma; Trujillo, Celina; Johnson, Caroline; Bradman, Asa; Barr, Dana Boyd

    2011-01-01

    Context: Organophosphate (OP) pesticides are neurotoxic at high doses. Few studies have examined whether chronic exposure at lower levels could adversely affect children’s cognitive development. Objective: We examined associations between prenatal and postnatal exposure to OP pesticides and cognitive abilities in school-age children. Methods: We conducted a birth cohort study (Center for the Health Assessment of Mothers and Children of Salinas study) among predominantly Latino farmworker families from an agricultural community in California. We assessed exposure to OP pesticides by measuring dialkyl phosphate (DAP) metabolites in urine collected during pregnancy and from children at 6 months and 1, 2, 3.5, and 5 years of age. We administered the Wechsler Intelligence Scale for Children, 4th edition, to 329 children 7 years of age. Analyses were adjusted for maternal education and intelligence, Home Observation for Measurement of the Environment score, and language of cognitive assessment. Results: Urinary DAP concentrations measured during the first and second half of pregnancy had similar relations to cognitive scores, so we used the average of concentrations measured during pregnancy in further analyses. Averaged maternal DAP concentrations were associated with poorer scores for Working Memory, Processing Speed, Verbal Comprehension, Perceptual Reasoning, and Full-Scale intelligence quotient (IQ). Children in the highest quintile of maternal DAP concentrations had an average deficit of 7.0 IQ points compared with those in the lowest quintile. However, children’s urinary DAP concentrations were not consistently associated with cognitive scores. Conclusions: Prenatal but not postnatal urinary DAP concentrations were associated with poorer intellectual development in 7-year-old children. Maternal urinary DAP concentrations in the present study were higher but nonetheless within the range of levels measured in the general U.S. population. PMID:21507776

  3. Exposures of children to organophosphate pesticides and their potential adverse health effects.

    PubMed Central

    Eskenazi, B; Bradman, A; Castorina, R

    1999-01-01

    Recent studies show that young children can be exposed to pesticides during normal oral exploration of their environment and their level of dermal contact with floors and other surfaces. Children living in agricultural areas may be exposed to higher pesticide levels than other children because of pesticides tracked into their homes by household members, by pesticide drift, by breast milk from their farmworker mother, or by playing in nearby fields. Nevertheless, few studies have assessed the extent of children's pesticide exposure, and no studies have examined whether there are adverse health effects of chronic exposure. There is substantial toxicologic evidence that repeated low-level exposure to organophosphate (OP) pesticides may affect neurodevelopment and growth in developing animals. For example, animal studies have reported neurobehavorial effects such as impairment on maze performance, locomotion, and balance in neonates exposed (italic)in utero(/italic) and during early postnatal life. Possible mechanisms for these effects include inhibition of brain acetylcholinesterase, downregulation of muscarinic receptors, decreased brain DNA synthesis, and reduced brain weight in offspring. Research findings also suggest that it is biologically plausible that OP exposure may be related to respiratory disease in children through dysregulation of the autonomic nervous system. The University of California Berkeley Center for Children's Environmental Health Research is working to build a community-university partnership to study the environmental health of rural children. This Center for the Health Assessment of Mothers and Children of Salinas, or CHAMACOS in Monterey County, California, will assess (italic)in utero(/italic) and postnatal OP pesticide exposure and the relationship of exposure to neurodevelopment, growth, and symptoms of respiratory illness in children. The ultimate goal of the center is to translate research findings into a reduction of children

  4. Paper-based acetylcholinesterase inhibition assay combining a wet system for organophosphate and carbamate pesticides detection

    PubMed Central

    Apilux, Amara; Isarankura-Na-Ayudhya, Chartchalerm; Tantimongcolwat, Tanawut; Prachayasittikul, Virapong

    2015-01-01

    A dramatic increase in pesticide usage in agriculture highlights the need for on-site monitoring for public health and safety. Here, a paper-based sensor combined with a wet system was developed for the simple and rapid screening of organophosphate (OP) and carbamate (CM) pesticides based on the inhibition of acetylcholinesterase (AChE). The paper-based sensor was designed as a foldable device consisting of a cover and detection sheets pre-prepared with indoxyl acetate and AChE, respectively. The paper-based sensor requires only the incubation of a sample on the test zone for 10 minutes, followed by closing of the foldable sheet to initiate the enzymatic reaction. Importantly, the buffer loading hole was additionally designed on the cover sheet to facilitate the interaction of the coated substrate and the immobilized enzyme. This subsequently facilitates the mixing of indoxyl acetate with AChE, resulting in the improved analytical performance of the sensor. The absence or decrease in blue color produced by the AChE hydrolysis of indoxyl acetate can be observed in the presence of OPs and CMs. Under optimized conditions and using image analysis, the limit of detection (LOD) of carbofuran, dichlorvos, carbaryl, paraoxon, and pirimicarb are 0.003, 0.3, 0.5, 0.6, and 0.6 ppm, respectively. The assay could be applied to determine OP and CM residues in spiked food samples. Visual interpretation of the color signal was clearly observed at the concentration of 5 mg/kg. Furthermore, a self-contained sample pre-concentration approach greatly enhanced the detection sensitivity. The paper-based device developed here is low-cost, requires minimal reagents and is easy to handle. As such, it would be practically useful for pesticide screening by non-professional end-users. PMID:26417364

  5. Paper-based acetylcholinesterase inhibition assay combining a wet system for organophosphate and carbamate pesticides detection.

    PubMed

    Apilux, Amara; Isarankura-Na-Ayudhya, Chartchalerm; Tantimongcolwat, Tanawut; Prachayasittikul, Virapong

    2015-01-01

    A dramatic increase in pesticide usage in agriculture highlights the need for on-site monitoring for public health and safety. Here, a paper-based sensor combined with a wet system was developed for the simple and rapid screening of organophosphate (OP) and carbamate (CM) pesticides based on the inhibition of acetylcholinesterase (AChE). The paper-based sensor was designed as a foldable device consisting of a cover and detection sheets pre-prepared with indoxyl acetate and AChE, respectively. The paper-based sensor requires only the incubation of a sample on the test zone for 10 minutes, followed by closing of the foldable sheet to initiate the enzymatic reaction. Importantly, the buffer loading hole was additionally designed on the cover sheet to facilitate the interaction of the coated substrate and the immobilized enzyme. This subsequently facilitates the mixing of indoxyl acetate with AChE, resulting in the improved analytical performance of the sensor. The absence or decrease in blue color produced by the AChE hydrolysis of indoxyl acetate can be observed in the presence of OPs and CMs. Under optimized conditions and using image analysis, the limit of detection (LOD) of carbofuran, dichlorvos, carbaryl, paraoxon, and pirimicarb are 0.003, 0.3, 0.5, 0.6, and 0.6 ppm, respectively. The assay could be applied to determine OP and CM residues in spiked food samples. Visual interpretation of the color signal was clearly observed at the concentration of 5 mg/kg. Furthermore, a self-contained sample pre-concentration approach greatly enhanced the detection sensitivity. The paper-based device developed here is low-cost, requires minimal reagents and is easy to handle. As such, it would be practically useful for pesticide screening by non-professional end-users. PMID:26417364

  6. Paraoxonase-1 genetic polymorphisms and susceptibility to DNA damage in workers occupationally exposed to organophosphate pesticides.

    PubMed

    Singh, Satyender; Kumar, Vivek; Thakur, Sachin; Banerjee, Basu Dev; Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen; Jain, Sudhir Kumar; Ichhpujani, Rattan Lal; Rai, Arvind

    2011-04-15

    Human paraoxonase 1 (PON1) is a lipoprotein-associated enzyme involved in the detoxification of organophosphate pesticides (OPs) by hydrolyzing the bioactive oxons. Polymorphisms of the PON1 gene are responsible for variation in the expression and catalytic activity of PON1 enzyme. In the present study, we have determined (a) the prevalence of two common PON1 polymorphisms, (b) the activity of PON1 and acetylcholinesterase enzymes, and (c) the influence of PON1 genotypes and phenotypes variation on DNA damage in workers exposed to OPs. We examined 230 subjects including 115 workers exposed to OPs and an equal number of normal healthy controls. The results revealed that PON1 activity toward paraoxon (179.19±39.36 vs. 241.52±42.32nmol/min/ml in controls) and phenylacetate (112.74±17.37 vs. 134.28±25.49μmol/min/ml in controls) was significantly lower in workers than in control subjects (p<0.001). No significant difference was observed in the distribution of genotypes and allelic frequencies of PON1(192)QR (Gln/Arg) and PON1(55)LM (Leu/Met) in workers and control subjects (p>0.05). The PON1 activity toward paraoxonase was found to be significantly higher in the R/R (Arg/Arg) genotypes than Q/R (Gln/Arg) and lowest in Q/Q (Gln/Gln) genotypes in both workers and control subjects (p<0.001). For PON1(55)LM (Leu/Met), PON1 activity toward paraoxonase was observed to be higher in individuals with L/L (Leu/Leu) genotypes and lowest in individuals with M/M (Met/Met) genotypes in both groups (p<0.001). No influence of PON1 genotypes and phenotypes was seen on the activity of acetylcholinesterase and arylesterase. The DNA damage was observed to be significantly higher in workers than in control subjects (p<0.05). Further, the individuals who showed least paraoxonase activity i.e., those with (Q/Q [Gln/Gln] and M/M [Met/Met]) genotypes showed significantly higher DNA damage compared to other isoforms in workers exposed to OPs (p<0.05). The results indicate that the

  7. Paraoxonase-1 genetic polymorphisms and susceptibility to DNA damage in workers occupationally exposed to organophosphate pesticides

    SciTech Connect

    Singh, Satyender; Kumar, Vivek; Thakur, Sachin; Banerjee, Basu Dev; Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen; Jain, Sudhir Kumar; Ichhpujani, Rattan Lal; Rai, Arvind

    2011-04-15

    Human paraoxonase 1 (PON1) is a lipoprotein-associated enzyme involved in the detoxification of organophosphate pesticides (OPs) by hydrolyzing the bioactive oxons. Polymorphisms of the PON1 gene are responsible for variation in the expression and catalytic activity of PON1 enzyme. In the present study, we have determined (a) the prevalence of two common PON1 polymorphisms, (b) the activity of PON1 and acetylcholinesterase enzymes, and (c) the influence of PON1 genotypes and phenotypes variation on DNA damage in workers exposed to OPs. We examined 230 subjects including 115 workers exposed to OPs and an equal number of normal healthy controls. The results revealed that PON1 activity toward paraoxon (179.19 {+-} 39.36 vs. 241.52 {+-} 42.32 nmol/min/ml in controls) and phenylacetate (112.74 {+-} 17.37 vs. 134.28 {+-} 25.49 {mu}mol/min/ml in controls) was significantly lower in workers than in control subjects (p < 0.001). No significant difference was observed in the distribution of genotypes and allelic frequencies of PON1{sub 192}QR (Gln/Arg) and PON1{sub 55}LM (Leu/Met) in workers and control subjects (p > 0.05). The PON1 activity toward paraoxonase was found to be significantly higher in the R/R (Arg/Arg) genotypes than Q/R (Gln/Arg) and lowest in Q/Q (Gln/Gln) genotypes in both workers and control subjects (p < 0.001). For PON1{sub 55}LM (Leu/Met), PON1 activity toward paraoxonase was observed to be higher in individuals with L/L (Leu/Leu) genotypes and lowest in individuals with M/M (Met/Met) genotypes in both groups (p < 0.001). No influence of PON1 genotypes and phenotypes was seen on the activity of acetylcholinesterase and arylesterase. The DNA damage was observed to be significantly higher in workers than in control subjects (p < 0.05). Further, the individuals who showed least paraoxonase activity i.e., those with (Q/Q [Gln/Gln] and M/M [Met/Met]) genotypes showed significantly higher DNA damage compared to other isoforms in workers exposed to OPs (p < 0

  8. Exposure characterization of three major insecticide lines in urine of young children in Japan-neonicotinoids, organophosphates, and pyrethroids.

    PubMed

    Osaka, Aya; Ueyama, Jun; Kondo, Takaaki; Nomura, Hiroshi; Sugiura, Yuka; Saito, Isao; Nakane, Kunihiko; Takaishi, Ayuko; Ogi, Hiroko; Wakusawa, Shinya; Ito, Yuki; Kamijima, Michihiro

    2016-05-01

    The use of neonicotinoid (NEO) insecticides has increased over the past decade not only in Japan but also worldwide, while organophosphate (OP) and pyrethroid (PYR) insecticides are still conventionally used in agriculture and domestic pest control. However, limited data are currently available on the NEO exposure levels, especially in children, who are particularly vulnerable to environmental toxicants. Thus, the purpose of this study was to characterize the exposure to NEOs, as well as OPs and PYRs, in three-year-old Japanese children by assessing the range, distribution, and seasonal differences of the urinary concentrations of seven NEOs (acetamiprid, clothianidin, dinotefuran, thiacloprid, thiamethoxam, imidacloprid, and nitenpyram); four OP metabolites (dialkylphosphates [DAPs]), including dimethylphosphate, dimethylthiophosphate, diethylphosphate, and diethylthiophosphate; and three PYR metabolites (3-phenoxybenzoic acid, trans-chrysanthemumdicarboxylic acid, and 3-(2,2-dichlorovinyl)-2,2- dimethylcyclopropane carboxylic acid). Urine samples were collected from 223 children (108 males and 115 females) in the summer and winter months. The detection rates of NEOs were 58% for dinotefuran, 25% for thiamethoxam, 21% for nitenpyram, and <16% for all other NEOs. The median and maximum concentrations of the sum of the seven NEOs (ΣNEO) were 4.7 and 370.2nmol/g creatinine, respectively. Urinary ΣNEO, dimethylphosphate, and all PYR metabolite concentrations were significantly higher in the summer than in the winter (p<0.05). The creatinine-adjusted concentration of ΣNEO significantly correlated with those of all DAPs (p<0.05) but not with those of the PYR metabolites. Moreover, the NEO-detected group showed higher urinary ΣDAP (sum of four OP metabolites) concentrations than the group without NEO detection. These findings suggest that children in Japan are environmentally exposed to the three major insecticide lines, and that the daily exposure sources of NEOs

  9. Exposure characterization of three major insecticide lines in urine of young children in Japan-neonicotinoids, organophosphates, and pyrethroids.

    PubMed

    Osaka, Aya; Ueyama, Jun; Kondo, Takaaki; Nomura, Hiroshi; Sugiura, Yuka; Saito, Isao; Nakane, Kunihiko; Takaishi, Ayuko; Ogi, Hiroko; Wakusawa, Shinya; Ito, Yuki; Kamijima, Michihiro

    2016-05-01

    The use of neonicotinoid (NEO) insecticides has increased over the past decade not only in Japan but also worldwide, while organophosphate (OP) and pyrethroid (PYR) insecticides are still conventionally used in agriculture and domestic pest control. However, limited data are currently available on the NEO exposure levels, especially in children, who are particularly vulnerable to environmental toxicants. Thus, the purpose of this study was to characterize the exposure to NEOs, as well as OPs and PYRs, in three-year-old Japanese children by assessing the range, distribution, and seasonal differences of the urinary concentrations of seven NEOs (acetamiprid, clothianidin, dinotefuran, thiacloprid, thiamethoxam, imidacloprid, and nitenpyram); four OP metabolites (dialkylphosphates [DAPs]), including dimethylphosphate, dimethylthiophosphate, diethylphosphate, and diethylthiophosphate; and three PYR metabolites (3-phenoxybenzoic acid, trans-chrysanthemumdicarboxylic acid, and 3-(2,2-dichlorovinyl)-2,2- dimethylcyclopropane carboxylic acid). Urine samples were collected from 223 children (108 males and 115 females) in the summer and winter months. The detection rates of NEOs were 58% for dinotefuran, 25% for thiamethoxam, 21% for nitenpyram, and <16% for all other NEOs. The median and maximum concentrations of the sum of the seven NEOs (ΣNEO) were 4.7 and 370.2nmol/g creatinine, respectively. Urinary ΣNEO, dimethylphosphate, and all PYR metabolite concentrations were significantly higher in the summer than in the winter (p<0.05). The creatinine-adjusted concentration of ΣNEO significantly correlated with those of all DAPs (p<0.05) but not with those of the PYR metabolites. Moreover, the NEO-detected group showed higher urinary ΣDAP (sum of four OP metabolites) concentrations than the group without NEO detection. These findings suggest that children in Japan are environmentally exposed to the three major insecticide lines, and that the daily exposure sources of NEOs

  10. The influence of tomato processing on residues of organochlorine and organophosphate insecticides and their associated dietary risk.

    PubMed

    Reiler, Emilie; Jørs, Erik; Bælum, Jesper; Huici, Omar; Alvarez Caero, Maria Mercedes; Cedergreen, Nina

    2015-09-15

    Due to the increasing food demand, the use of pesticides in agriculture is increasing. Particularly in low income countries poor training among farmers, combined with the use of obsolete pesticides may result in a high risk for the consumers. In this study six organochlorines and five organophosphates were analyzed in 54 samples of tomatoes from small scale farmers in Bolivia. The analyses were done on unprocessed, stored, washed and peeled tomatoes. The cumulated risk associated with consumption of the tomatoes after different storage times and processing treatments was evaluated using the Hazard Index (HI) for acute risk assessment. All 11 pesticides were detected in the analyses although several of them are obsolete and included in the Stockholm convention ratified by Bolivia. The organochlorines were found in the μg pesticide/kg tomato range and below the HI, while the organophosphates were present in the mg pesticide/kg tomato range and most often above the HI. The low organochlorine concentrations were not significantly affected by time or treatment, but storage significantly decreased the concentrations of organophosphates. Washing decreased the initial concentrations to between 53% (malathion) down to 2% (ethyl parathion), while peeling had a larger effect reducing the initial concentrations to between 33% (malathion) and 0.7% (chlorpyriphos). Both the acute and chronic cumulative risk assessment of organophosphates showed a dietary risk for unprocessed tomatoes three days after harvest. For children, also the consumption of washed tomatoes constituted a dietary risk. To reduce the dietary risk of pesticide residues in Bolivia, there is an urgent need of farmer education and introduction of less hazardous pesticides as well as resources for surveillance and enforcement of legislation in order to ensure public health. PMID:25965039

  11. Design of a macroalgae amperometric biosensor; application to the rapid monitoring of organophosphate insecticides in an agroecosystem.

    PubMed

    Nunes, G S; Lins, J A P; Silva, F G S; Araujo, L C; Silva, F E P S; Mendonça, C D; Badea, M; Hayat, A; Marty, J-L

    2014-09-01

    The immobilization of enzymes onto transducer support is a mature technology and has been successfully implemented to improve biocatalytic processes for diverse applications. However, there exists still need to design more sophisticated and specialized strategies to enhance the functional properties of the biosensors. In this work, a biosensor platform based on innovative fabrication strategy was designed, and employed for the detection of organophosphate (OP) in natural waters. The biosensor was prepared by incorporating acetylcholinesterase enzyme (AChE) to the graphite paste modified with tetracyanoquinodimethane (TCNQ) mediator, along with the use of a macroalgae (Cladaphropsis membranous) as a functional immobilization support. The novel immobilization design resulted in a synergic effect, and led to enhanced stability and sensitivity of the biosensor. The designed biosensor was used to analyze methyl parathion OP insecticide in water samples collected from a demonstrably contaminated lake of São Luis Island, Maranhão, Northeast of Brazil. Water analysis revealed that the aquatic ecosystem was polluted by sub-ppm concentrations of the OP insecticide, and a good correlation was found between values obtained through biosensor and GC-MS techniques. Our results demonstrated that macroalgae-biosensor could be used as a low-cost and sensitive screening method to detect target analyte. PMID:24997974

  12. Engineering Pseudomonas putida KT2440 for simultaneous degradation of organophosphates and pyrethroids and its application in bioremediation of soil.

    PubMed

    Zuo, Zhenqiang; Gong, Ting; Che, You; Liu, Ruihua; Xu, Ping; Jiang, Hong; Qiao, Chuanling; Song, Cunjiang; Yang, Chao

    2015-06-01

    Agricultural soils are usually co-contaminated with organophosphate (OP) and pyrethroid pesticides. To develop a stable and marker-free Pseudomonas putida for co-expression of two pesticide-degrading enzymes, we constructed a suicide plasmid with expression cassettes containing a constitutive promoter J23119, an OP-degrading gene (mpd), a pyrethroid-hydrolyzing carboxylesterase gene (pytH) that utilizes the upp gene as a counter-selectable marker for upp-deficient P. putida. By introduction of suicide plasmid and two-step homologous recombination, both mpd and pytH genes were integrated into the chromosome of a robust soil bacterium P. putida KT2440 and no selection marker was left on chromosome. Functional expression of mpd and pytH in P. putida KT2440 was demonstrated by Western blot analysis and enzyme activity assays. Degradation experiments with liquid cultures showed that the mixed pesticides including methyl parathion, fenitrothion, chlorpyrifos, permethrin, fenpropathrin, and cypermethrin (0.2 mM each) were degraded completely within 48 h. The inoculation of engineered strain (10(6) cells/g) to soils treated with the above mixed pesticides resulted in a higher degradation rate than in noninoculated soils. All six pesticides could be degraded completely within 15 days in fumigated and nonfumigated soils with inoculation. Theses results highlight the potential of the engineered strain to be used for in situ bioremediation of soils co-contaminated with OP and pyrethroid pesticides.

  13. Reliability of concentrations of organophosphate pesticide metabolites in serial urine specimens from pregnancy in the Generation R Study.

    PubMed

    Spaan, Suzanne; Pronk, Anjoeka; Koch, Holger M; Jusko, Todd A; Jaddoe, Vincent W V; Shaw, Pamela A; Tiemeier, Henning M; Hofman, Albert; Pierik, Frank H; Longnecker, Matthew P

    2015-05-01

    The widespread use of organophosphate (OP) pesticides has resulted in ubiquitous exposure in humans, primarily through their diet. Exposure to OP pesticides may have adverse health effects, including neurobehavioral deficits in children. The optimal design of new studies requires data on the reliability of urinary measures of exposure. In the present study, urinary concentrations of six dialkyl phosphate (DAP) metabolites, the main urinary metabolites of OP pesticides, were determined in 120 pregnant women participating in the Generation R Study in Rotterdam. Intra-class correlation coefficients (ICCs) across serial urine specimens taken at <18, 18-25, and >25 weeks of pregnancy were determined to assess reliability. Geometric mean total DAP metabolite concentrations were 229 (GSD 2.2), 240 (GSD 2.1), and 224 (GSD 2.2) nmol/g creatinine across the three periods of gestation. Metabolite concentrations from the serial urine specimens in general correlated moderately. The ICCs for the six DAP metabolites ranged from 0.14 to 0.38 (0.30 for total DAPs), indicating weak to moderate reliability. Although the DAP metabolite levels observed in this study are slightly higher and slightly more correlated than in previous studies, the low to moderate reliability indicates a high degree of within-person variability, which presents challenges for designing well-powered epidemiological studies. PMID:25515376

  14. Organophosphate agents induce plasma hypertriglyceridemia in mouse via single or dual inhibition of the endocannabinoid hydrolyzing enzyme(s).

    PubMed

    Suzuki, Himiko; Ito, Yuki; Noro, Yuki; Koketsu, Mamoru; Kamijima, Michihiro; Tomizawa, Motohiro

    2014-02-10

    Diverse serine hydrolases including endocannabinoid metabolizing enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) have been suggested as secondary targets for organophosphate (OP) agents to exert adverse toxic effects such as lipid homeostasis disruption. The goal of this investigation is to verify that a major OP insecticide fenitrothion (FNT) induces plasma hypertriglyceridemia through the inhibition of FAAH and/or MAGL in comparison with that elicited by isopropyl dodecylfluorophosphonate (IDFP), a potent FAAH/MAGL inhibitor. Fasted mice were treated intraperitoneally with FNT or IDFP and were subsequently sacrificed for evaluations of plasma triglyceride (TG) levels and liver FAAH/MAGL activities. Plasma TG levels were significantly enhanced by the FNT or IDFP treatment (1.7- or 4.8-fold, respectively) compared with that of vehicle control. The IDFP exposure reduced the liver FAAH and MAGL activities, whereas the FNT exposure led to the preferential FAAH inhibition. The brain acetylcholinesterase was almost unaffected by the FNT or IDFP treatment, thus leading to no neurotoxic sign. Intriguingly, the TG elevations were averted by concomitant administration with the cannabinoid receptor antagonist AM251. The present findings suggest that OP agents induce plasma hypertriglyceridemia in mouse through single or dual inhibition of FAAH or/and MAGL, apparently leading to overstimulation of cannabinoid signal regulating energy metabolism. PMID:24361246

  15. Design of a macroalgae amperometric biosensor; application to the rapid monitoring of organophosphate insecticides in an agroecosystem.

    PubMed

    Nunes, G S; Lins, J A P; Silva, F G S; Araujo, L C; Silva, F E P S; Mendonça, C D; Badea, M; Hayat, A; Marty, J-L

    2014-09-01

    The immobilization of enzymes onto transducer support is a mature technology and has been successfully implemented to improve biocatalytic processes for diverse applications. However, there exists still need to design more sophisticated and specialized strategies to enhance the functional properties of the biosensors. In this work, a biosensor platform based on innovative fabrication strategy was designed, and employed for the detection of organophosphate (OP) in natural waters. The biosensor was prepared by incorporating acetylcholinesterase enzyme (AChE) to the graphite paste modified with tetracyanoquinodimethane (TCNQ) mediator, along with the use of a macroalgae (Cladaphropsis membranous) as a functional immobilization support. The novel immobilization design resulted in a synergic effect, and led to enhanced stability and sensitivity of the biosensor. The designed biosensor was used to analyze methyl parathion OP insecticide in water samples collected from a demonstrably contaminated lake of São Luis Island, Maranhão, Northeast of Brazil. Water analysis revealed that the aquatic ecosystem was polluted by sub-ppm concentrations of the OP insecticide, and a good correlation was found between values obtained through biosensor and GC-MS techniques. Our results demonstrated that macroalgae-biosensor could be used as a low-cost and sensitive screening method to detect target analyte.

  16. Organophosphate agents induce plasma hypertriglyceridemia in mouse via single or dual inhibition of the endocannabinoid hydrolyzing enzyme(s).

    PubMed

    Suzuki, Himiko; Ito, Yuki; Noro, Yuki; Koketsu, Mamoru; Kamijima, Michihiro; Tomizawa, Motohiro

    2014-02-10

    Diverse serine hydrolases including endocannabinoid metabolizing enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) have been suggested as secondary targets for organophosphate (OP) agents to exert adverse toxic effects such as lipid homeostasis disruption. The goal of this investigation is to verify that a major OP insecticide fenitrothion (FNT) induces plasma hypertriglyceridemia through the inhibition of FAAH and/or MAGL in comparison with that elicited by isopropyl dodecylfluorophosphonate (IDFP), a potent FAAH/MAGL inhibitor. Fasted mice were treated intraperitoneally with FNT or IDFP and were subsequently sacrificed for evaluations of plasma triglyceride (TG) levels and liver FAAH/MAGL activities. Plasma TG levels were significantly enhanced by the FNT or IDFP treatment (1.7- or 4.8-fold, respectively) compared with that of vehicle control. The IDFP exposure reduced the liver FAAH and MAGL activities, whereas the FNT exposure led to the preferential FAAH inhibition. The brain acetylcholinesterase was almost unaffected by the FNT or IDFP treatment, thus leading to no neurotoxic sign. Intriguingly, the TG elevations were averted by concomitant administration with the cannabinoid receptor antagonist AM251. The present findings suggest that OP agents induce plasma hypertriglyceridemia in mouse through single or dual inhibition of FAAH or/and MAGL, apparently leading to overstimulation of cannabinoid signal regulating energy metabolism.

  17. A comparative study on the relationship between acetylcholinesterase activity and acute toxicity in Daphnia magna exposed to anticholinesterase insecticides.

    PubMed

    Printes, Liane Biehl; Callaghan, Amanda

    2004-05-01

    Acetylcholinesterase (AChE) activity was measured in Daphnia magna that had been exposed to four organophosphates (OPs; parathion, chlorpyrifos, malathion, and acephate) and one carbamate (propoxur) for 48 h. These results were related to acute toxicity (median effective concentration [EC50] for immobility). For the four OPs, the EC50s were 7.03 pM, 3.17 pM, 10.56 pM, and 309.82 microM, respectively. The EC50 for propoxur was 449.90 pM. Reduction in AChE activity was directly related to an increase in immobility in all chemicals tested. However, the ratio between the EC50 and the AChE median inhibiting concentration ranged from 0.31 to 0.90. A 50% reduction in AChE activity generally was associated with detrimental effects on mobility. However, for acephate, high levels of AChE inhibition (70%) were observed in very low concentrations and were not associated with immobility. In addition, increasing the concentration of acephate further had a slight negative effect on AChE activity but a strong detrimental effect on mobility. Binding sites other than AChE possibly are involved in acephate toxicity to D. magna. Our findings demonstrate different associations between AChE inhibition and toxicity when different chemicals are compared. Therefore, the value of using AChE activity as a biomarker in D. magna will be dependent on the chemical tested.

  18. Oxidative stress related to chlorpyrifos exposure in rainbow trout: Acute and medium term effects on genetic biomarkers.

    PubMed

    Benedetto, A; Brizio, P; Squadrone, S; Scanzio, T; Righetti, M; Gasco, L; Prearo, M; Abete, M C

    2016-05-01

    Organophosphates (OPs) are derivatives of phosphoric acid widely used in agriculture as pesticides. Chlorpyrifos (CPF) is an OP that is extremely toxic to aquatic organisms. Rainbow trout (Oncorhynchus mykiss) is considered as a sentinel model species for ecotoxicology assessment in freshwater ecosystems. An exposure study was carried out on rainbow trout to investigate genetic responses to CPF-induced oxidative stress by Real-Time PCR, and to determine the accumulation dynamics of CPF and toxic metabolite chlorpyrifos-oxon (CPF-ox) in edible parts, by HPLC-MS/MS. Among the genes considered to be related to oxidative stress, a significant increase in HSP70 mRNA levels was observed in liver samples up to 14 days after CPF exposure (0.05 mg/L). CPF concentrations in muscle samples reach mean values of 285.25 ng/g within 96 hours of exposure, while CPF-ox concentrations were always under the limit of quantification (LOQ) of the applied method. Our findings lead us to consider HSP70 as a suitable genetic marker in rainbow trout for acute and medium-term monitoring of CPF exposure, complementary to analytical determinations.

  19. Scenario of organophosphate pollution and toxicity in India: A review.

    PubMed

    Kumar, Shardendu; Kaushik, Garima; Villarreal-Chiu, Juan Francisco

    2016-05-01

    The present study on organophosphate deals with the reports on pollution and toxicity cases throughout India. The use of pesticides was introduced in India during the 1960s which are now being used on a large scale and represents the common feature of Indian agriculture. Use of organophosphates as a pesticide came as an alternative to chlorinated hydrocarbons due to their easy degradability. Although these xenobiotics degrade under natural condition, their residues have been detected in soil, sediments, and water due to their non-regulated usage practice. The over-reliance on pesticides has not only threatened our environment but contaminations of organophosphate residues have been also detected in certain agricultural products like tea, sugars, vegetables, and fruits throughout India. This paper highlights many of the cases where different organophosphates have been detected exceeding their respective MRL values. Some organophosphates detected are so hazardous that even WHO has listed them in class 1a and class 1b hazardous group. Presence of their residues in blood, milk, honey, and tissues of human and animals revealed their excessive use and bioaccumulating capabilities. Their intentional or unintentional uptake is causing thousands of deaths and severity each year. Most of the toxicity cases presented here are due to their uptake during a suicidal attempt. This shows how easily these harmful substances are available in the market. PMID:26916265

  20. Modulation of dopaminergic neurotransmission induced by sublethal doses of the organophosphate trichlorfon in cockroaches.

    PubMed

    Stürmer, Graziele Daiane; de Freitas, Thiago Carrazoni; Heberle, Marines de Avila; de Assis, Dênis Reis; Vinadé, Lúcia; Pereira, Antônio Batista; Franco, Jeferson Luis; Dal Belo, Cháriston André

    2014-11-01

    Organophosphate (OP) insecticides have been used indiscriminately, based on their high dissipation rates and low residual levels in the environment. Despite the toxicity of OPs to beneficial insects is principally devoted to the acetylcholinesterase (AChE) inhibition, the physiological mechanisms underlying this activity remain poorly understood. Here we showed the pharmacological pathways that might be involved in severe alterations in the insect locomotion and grooming behaviors following sublethal administration of the OP Trichlorfon (Tn) (0.25, 0.5 and 1 µM) in Phoetalia pallida. Tn inhibited the acetylcholinesterase activity (46±6, 38±3 and 24±6 nmol NADPH/min/mg protein, n=3, p<0.05), respectively. Tn (1 µM) also increased the walking maintenance of animals (46±5 s; n=27; p<0.05). Tn caused a high increase in the time spent for this behavior (344±18 s/30 min, 388±18 s/30 min and 228±12 s/30 min, n=29-30, p<0.05, respectively). The previous treatment of the animals with different cholinergic modulators showed that pirenzepine>atropine>oxotremorine>d-tubocurarine>tropicamide>methoctramine induced a decrease on Tn (0.5 µM)-induced grooming increase, respectively in order of potency. Metoclopramide (0.4 µM), a DA-D2 selective inhibitor decreased the Tn-induced grooming activity (158±12 s/30 min; n=29; p<0.05). Nevertheless, the effect of the selective DA-D1 receptor blocker SCH 23390 (1.85 µM) on the Tn (0.5 µM)-induced grooming increase was significative and more intense than that of metoclopramide (54±6 s/30 min; n=30; p<0.05). Taken together the results suggest that a cross-talking between cholinergic M1/M3 and dopaminergic D1 receptors at the insect nervous system may play a role in the OP-mediated behavioral alterations.

  1. Inhalation exposure of organophosphate pesticides by vegetable growers in the Bang-Rieng subdistrict in Thailand.

    PubMed

    Jaipieam, Somsiri; Visuthismajarn, Parichart; Siriwong, Wattasit; Borjan, Marija; Robson, Mark G

    2009-01-01

    This study investigated inhalation exposure to organophosphate pesticides (OPPs) and evaluated the associated health risks to vegetable growers living in the Bang-Rieng agricultural community. Air samples were collected by using personal sampling pumps with sorbent tubes placed in the vegetable growers' breathing zone. Samples were collected during both wet and dry seasons. Residues of organophosphate pesticides, that is, chlorpyrifos, dicrotofos, and profenofos, were analyzed from 33 vegetable growers and 17 reference subjects. Results showed that median concentrations of OPPs in air in farm areas were in the range of 0.022-0.056 mg/m(3) and air in nonfarm areas in the range of <0.0016-<0.005 mg/m(3). The concentration of the three pesticides in the vegetable growers was significantly higher than that of the references during both seasons. The results also indicate that the vegetable growers may be at risk for acute adverse effects via the inhalation of chlorpyrifos and dicrotofos during pesticide application, mixing, loading, and spraying. It is suggested that authorities and the community should implement appropriate strategies concerning risk reduction and risk management. PMID:20168980

  2. Plant Esterase-Chitosan/Gold Nanoparticles-Graphene Nanosheet Composite-Based Biosensor for the Ultrasensitive Detection of Organophosphate Pesticides.

    PubMed

    Bao, Jing; Hou, Changjun; Chen, Mei; Li, Junjie; Huo, Danqun; Yang, Mei; Luo, Xiaogang; Lei, Yu

    2015-12-01

    As broad-spectrum pesticides, organophosphates (OPs) are widely used in agriculture all over the world. However, due to their neurotoxicity in humans and their increasing occurrence in the environment, there is growing interest in their sensitive and selective detection. This paper reports a new cost-effective plant esterase-chitosan/gold nanoparticles-graphene nanosheet (PLaE-CS/AuNPs-GNs) biosensor for the sensitive detection of methyl parathion and malathion. Highly pure plant esterase is produced from plants at low cost and shares the same inhibition mechanism with OPs as acetylcholinesterase, and then it was used to prepare PLaE-CS/AuNPs-GNs nanocomposites, which were systematically characterized using SEM, TEM, and UV-vis. The PLaE-CS/AuNPs-GNs composite-based biosensor measured as low as 50 ppt (0.19 nM) of methyl parathion and 0.5 ppb (1.51 nM) of malathion (S/N = 3) with a calibration curve up to 200 ppb (760 nM) and 500 ppb (1513.5 nM) for methyl parathion and malathion, respectively. There is also no interference observed from most of common species such as metal ions, inorganic ions, glucose, and citric acid. In addition, its applicability to OPs-contaminated real samples (carrot and apple) was also demonstrated with excellent response recovery. The developed simple, sensitive, and reliable PLaE-CS/AuNPs-GNs composite-based biosensor holds great potential in OPs detection for food and environmental safety.

  3. Plant Esterase-Chitosan/Gold Nanoparticles-Graphene Nanosheet Composite-Based Biosensor for the Ultrasensitive Detection of Organophosphate Pesticides.

    PubMed

    Bao, Jing; Hou, Changjun; Chen, Mei; Li, Junjie; Huo, Danqun; Yang, Mei; Luo, Xiaogang; Lei, Yu

    2015-12-01

    As broad-spectrum pesticides, organophosphates (OPs) are widely used in agriculture all over the world. However, due to their neurotoxicity in humans and their increasing occurrence in the environment, there is growing interest in their sensitive and selective detection. This paper reports a new cost-effective plant esterase-chitosan/gold nanoparticles-graphene nanosheet (PLaE-CS/AuNPs-GNs) biosensor for the sensitive detection of methyl parathion and malathion. Highly pure plant esterase is produced from plants at low cost and shares the same inhibition mechanism with OPs as acetylcholinesterase, and then it was used to prepare PLaE-CS/AuNPs-GNs nanocomposites, which were systematically characterized using SEM, TEM, and UV-vis. The PLaE-CS/AuNPs-GNs composite-based biosensor measured as low as 50 ppt (0.19 nM) of methyl parathion and 0.5 ppb (1.51 nM) of malathion (S/N = 3) with a calibration curve up to 200 ppb (760 nM) and 500 ppb (1513.5 nM) for methyl parathion and malathion, respectively. There is also no interference observed from most of common species such as metal ions, inorganic ions, glucose, and citric acid. In addition, its applicability to OPs-contaminated real samples (carrot and apple) was also demonstrated with excellent response recovery. The developed simple, sensitive, and reliable PLaE-CS/AuNPs-GNs composite-based biosensor holds great potential in OPs detection for food and environmental safety. PMID:26554573

  4. Multimedia transport and risk assessment of organophosphate pesticides and a case study in the northern San Joaquin Valley of California.

    PubMed

    Luo, Yuzhou; Zhang, Minghua

    2009-05-01

    This paper presents a framework for cumulative risk characterization of human exposure to pesticides through multiple exposure pathways. This framework is illustrated through a case study of selected organophosphate (OP) pesticides in the northern San Joaquin Valley of California. Chemical concentrations in environmental media were simulated using a multimedia environmental fate model, and converted to contamination levels in exposure media. The risk characterization in this study was based on a residential-scale exposure to residues of multiple pesticides through everyday activities. Doses from a mixture of OP pesticides that share a common mechanism of toxicity were estimated following US Environmental Protection Agency guidelines for cumulative risk analysis. Uncertainty in the human exposure parameters was included in the Monte Carlo simulation in order to perform stochastic calculations for intakes and corresponding risks of OP pesticides. Risk of brain acetylcholinesterase inhibition was reported as margins of exposure (MOEs) of the 99.9th population percentile for two age groups living in the northern San Joaquin Valley during 1992-2005. Diet was identified as the dominant exposure pathway in cumulative exposure and risk, while the temporal trend and spatial variation in total MOE levels were associated with exposures to contaminated drinking water and ambient air. Uniformly higher risks were observed for children because of their greater inhalation and ingestion rates per body weight, relative to adults. The results indicated that exposures for children were about twice of those estimated for adults. Concerns over children's exposure to OP pesticide through food and water ingestion were suggested based on the spatiotemporal variations predicted for the subchronic MOEs at the 99.9th percentile of exposure in the study area.

  5. Evaluating organophosphate poisoning in human serum with paper.

    PubMed

    Yen, Tzung-Hai; Chen, Kuan-Hung; Hsu, Min-Yen; Fan, Shu-Ting; Huang, Yu-Fen; Chang, Chia-Ling; Wang, Yu-Ping; Cheng, Chao-Min

    2015-11-01

    This manuscript describes the development and clinical testing of a paper-based, metabolic assay designed for rapid, semi-quantitative measurement of organophosphate poisoning. Paper-based platforms, including point-of-care devices and 96-well plates, provided semi-quantitative information regarding the concentration of AchE (a biomarker for organophosphate poisoning). The paper-based 96-well-plate developed and implemented in this study was used to measure the level of organophosphate poisoning in three different clinical patients. Results were comparable to those obtained using conventional hospital methods currently considered the "gold standard". This diagnostic device offers several advantages over conventional methods, including short operating time (twice as fast as conventional methods), procedure simplicity, and reduced fabrication cost. With further commercialization efforts, the methods described in this manuscript could be applied to a wide range of potential diagnostic applications in the field.

  6. Reprint of 'Evaluating organophosphate poisoning in human serum with paper'.

    PubMed

    Yen, Tzung-Hai; Chen, Kuan-Hung; Hsu, Min-Yen; Fan, Shu-Ting; Huang, Yu-Fen; Chang, Chia-Ling; Wang, Yu-Ping; Cheng, Chao-Min

    2015-12-01

    This manuscript describes the development and clinical testing of a paper-based, metabolic assay designed for rapid, semi-quantitative measurement of organophosphate poisoning. Paper-based platforms, including point-of-care devices and 96-well plates, provided semi-quantitative information regarding the concentration of AchE (a biomarker for organophosphate poisoning). The paper-based 96-well-plate developed and implemented in this study was used to measure the level of organophosphate poisoning in three different clinical patients. Results were comparable to those obtained using conventional hospital methods currently considered the "gold standard". This diagnostic device offers several advantages over conventional methods, including short operating time (twice as fast as conventional methods), procedure simplicity, and reduced fabrication cost. With further commercialization efforts, the methods described in this manuscript could be applied to a wide range of potential diagnostic applications in the field.

  7. Organophosphate pesticide concentrations in coral tissues of Indonesian coastal waters.

    PubMed

    Sabdono, Agus; Kang, Suil; Hur, Hor-Gil; Grossart, Hans-Peter; Simon, Meinhard; Radjasa, Ocky Kama

    2007-06-01

    In this study we evaluated the persistence of diazinon, chlorpyrifos, profenofos, parathion, malathion and ethion in dead coral tissues of Indonesian coastal waters (Java, Bali, Sulawesi and Komodo). Comparison of the residue levels in coral tissues showed that the highest presence of organophosphate concentrations was detected in a coral sample collected from Java coastal waters. While medium amounts of a contaminant diazinon can still lead to detectable in Bali and Sulawesi coastal waters. Prominent contamination of organophosphate was not found in a sample collected from Komodo. Neither parathion nor malathion were detected in any of the samples. This result implies that the geographical variations of organophosphate compounds are determined by the possible usage of these chemicals around coastal waters at the present or in the past. There is need for further work to identify sources and fate of pesticide contaminants, as well as to improve monitoring of pesticide use. PMID:19086563

  8. Interaction of organophosphate pesticides and related compounds with the androgen receptor.

    PubMed Central

    Tamura, Hiroto; Yoshikawa, Hiromichi; Gaido, Kevin W; Ross, Susan M; DeLisle, Robert K; Welsh, William J; Richard, Ann M

    2003-01-01

    Identification of several environmental chemicals capable of binding to the androgen receptor (AR) and interfering with its normal function has heightened concern about adverse effects across a broad spectrum of environmental chemicals. We previously demonstrated AR antagonist activity of the organophosphate (OP) pesticide fenitrothion. In this study, we characterized AR activity of analogues of fenitrothion to probe the structural requirements for AR activity among related chemicals. AR activity was measured using HepG2 human hepatoma cells transfected with human AR plus an androgen-responsive luciferase reporter gene, MMTV-luc. AR antagonist activity decreased as alkyl chain length of the phosphoester increased, whereas electron-donating properties of phenyl substituents of the tested compounds did not influence AR activity. Oxon derivatives of fenitrothion, which are more likely to undergo hydrolytic degradation, had no detectable AR antagonist activity. Molecular modeling results suggest that hydrogen-bond energies and the maximum achievable interatomic distance between two terminal H-bond capable sites may influence both the potential to interact with the AR and the nature of the interaction (agonist vs. antagonist) within this series of chemicals. This hypothesis is supported by the results of recent AR homology modeling and crystallographic studies relative to agonist- and antagonist-bound AR complexes. The present results are placed in the context of structure-activity knowledge derived from previous modeling studies as well as studies aimed toward designing nonsteroidal antiandrogen pharmaceuticals. Present results extend understanding of the structural requirements for AR activity to a new class of nonsteroidal, environmental, OP-related chemicals. PMID:12676613

  9. Organophosphate Pesticide Exposure and Neurodevelopment in Young Mexican-American Children

    PubMed Central

    Eskenazi, Brenda; Marks, Amy R.; Bradman, Asa; Harley, Kim; Barr, Dana B.; Johnson, Caroline; Morga, Norma; Jewell, Nicholas P.

    2007-01-01

    Background Organophosphate (OP) pesticides are widely used in agriculture and homes. Animal studies suggest that even moderate doses are neurodevelopmental toxicants, but there are few studies in humans. Objectives We investigated the relationship of prenatal and child OP urinary metabolite levels with children’s neurodevelopment. Methods Participating children were from a longitudinal birth cohort of primarily Latino farm-worker families in California. We measured six nonspecific dialkylphosphate (DAP) metabolites in maternal and child urine as well as metabolites specific to malathion (MDA) and chlorpyrifos (TCPy) in maternal urine. We examined their association with children’s performance at 6 (n = 396), 12 (n = 395), and 24 (n = 372) months of age on the Bayley Scales of Infant Development [Mental Development (MDI) and Psychomotor Development (PDI) Indices] and mother’s report on the Child Behavior Checklist (CBCL) (n = 356). Results Generally, pregnancy DAP levels were negatively associated with MDI, but child measures were positively associated. At 24 months of age, these associations reached statistical significance [per 10-fold increase in prenatal DAPs: β = −3.5 points; 95% confidence interval (CI), −6.6 to −0.5; child DAPs: β = 2.4 points; 95% CI, 0.5 to 4.2]. Neither prenatal nor child DAPs were associated with PDI or CBCL attention problems, but both prenatal and postnatal DAPs were associated with risk of pervasive developmental disorder [per 10-fold increase in prenatal DAPs: odds ratio (OR) = 2.3, p = 0.05; child DAPs OR = 1.7, p = 0.04]. MDA and TCPy were not associated with any outcome. Conclusions We report adverse associations of prenatal DAPs with mental development and pervasive developmental problems at 24 months of age. Results should be interpreted with caution given the observed positive relationship with postnatal DAPs. PMID:17520070

  10. Modeling effectiveness of agricultural BMPs to reduce sediment load and organophosphate pesticides in surface runoff.

    PubMed

    Zhang, Xuyang; Zhang, Minghua

    2011-04-15

    Quantifying effectiveness of agricultural BMPs at the watershed scale is a challenging issue, requiring robust algorithms to simulate not only the agricultural production system but also pollutant transport and fate. This research addresses the challenge to simulate performances of BMPs in reducing organophosphates (OPs) runoff at the watershed scale. The SWAT model is calibrated and validated following a sensitivity analysis combining Latin Hypercube sampling and One-factor-At-a-Time simulation. The calibrated model is then applied in the Orestimba Creek Watershed to simulate BMPs including buffer strips, sediment ponds, vegetated ditches, use reduction, and their combinations. BMP simulation suggested that sediment ponds trap 54-85% of sediment from field runoff, but less than 10% of dissolved diazinon and chlorpyrifos. Use reduction can reduce pesticide load in a close-to-linear fashion. Effectiveness of vegetated ditches and buffers depends on their physical dimension and vegetation cover. Combining individual BMPs provides enhanced mitigation effects. The combination of vegetated ditches, buffer strips and use reduction decreases diazinon and chlorpyrifos load by over 94%. This study has suggested that the SWAT model reasonably predicts BMP effectiveness at the watershed scale. Results will assist decision making in implementing BMPs to reduce pesticide loads in surface runoff. PMID:21377192

  11. Acetylcholinesterase 1 in populations of organophosphate-resistant North American strains of the cattle tick, Rhipicephalus microplus (Acari: Ixodidae).

    PubMed

    Bendele, Kylie G; Guerrero, Felix D; Miller, Robert J; Li, Andrew Y; Barrero, Roberto A; Moolhuijzen, Paula M; Black, Michael; McCooke, John K; Meyer, Jason; Hill, Catherine A; Bellgard, Matthew I

    2015-08-01

    Rhipicephalus microplus, the cattle fever tick, is a global economic problem to the cattle industry due to direct infestation of cattle and pathogens transmitted during feeding. Cattle fever tick outbreaks continue to occur along the Mexico-US border even though the tick has been eradicated from the USA. The organophosphate (OP) coumaphos targets acetylcholinesterase (AChE) and is the approved acaricide for eradicating cattle fever tick outbreaks. There is evidence for coumaphos resistance developing in cattle ticks in Mexico, and OP-resistant R. microplus ticks were discovered in outbreak populations of Texas in 2005. The molecular basis of coumaphos resistance is not known, and our study was established to gather further information on whether AChE1 is involved in the resistance mechanism. We also sought information on allele diversity in tick populations with different levels of coumaphos resistance. The overarching project goal was to define OP resistance-associated gene mutations such that a DNA-based diagnostic assay could be developed to assist the management of resistance. Three different AChE transcripts have been reported in R. microplus, and supporting genomic and transcriptomic data are available at CattleTickBase. Here, we report the complete R. microplus AChE1 gene ascertained by sequencing a bacterial artificial chromosome clone containing the entire coding region and the flanking 5' and 3' regions. We also report AChE1 sequences of larval ticks from R. microplus strains having different sensitivities to OP. To accomplish this, we sequenced a 669-bp region of the AChE1 gene corresponding to a 223 amino acid region of exon 2 to assess alleles in seven strains of R. microplus with varying OP resistance phenotypes. We identified 72 AChE1 sequence variants, 2 of which are strongly associated with OP-resistant phenotypes. Esterase-like sequences from the R. microplus transcriptome RmiTr Version 1.0 were compared to the available sequence databases to

  12. ORGANOPHOSPHORUS HYDROLASE-BASED ASSAY FOR ORGANOPHOSPHATE PESTICIDES

    EPA Science Inventory

    We report a rapid and versatile Organophosphorus hydrolase (OPH)-based method for measurement of organophosphates. This assay is based on a substrate-dependent change in pH at the local vicinity of the enzyme. The pH change is monitored using fluorescein isothiocyanate (FITC), ...

  13. Metallic organophosphates as catalysts in asymmetric synthesis: a return journey.

    PubMed

    Parra, Alejandro; Reboredo, Silvia; Martín Castro, Ana M; Alemán, José

    2012-07-14

    This perspective article provides a general overview of the most relevant topics in the applications of chiral metallic organophosphates. A brief introduction along with a historic comparative profile of the BINOL and phosphoric acid analogues are given. Next, a selection of the most outstanding uses of the catalysts according to the employed metal is presented.

  14. Biosensor based on acetylcholinesterase immobilized onto layered double hydroxides for flow injection/amperometric detection of organophosphate pesticides.

    PubMed

    Gong, Jingming; Guan, Zhangqiong; Song, Dandan

    2013-01-15

    We developed a highly sensitive flow injection/amperometric biosensor for the detection of organophosphate pesticides (OPs) using layered double hydroxides (LDHs) as the immobilization matrix of acetylcholinesterase (AChE). LDHs provided a biocompatible microenvironment to keep the bioactivity of AChE, due to the intrinsic properties of LDHs (such as a regular structure, good mechanical, chemical and thermal stabilities, and swelling properties). By integrating the flow injection analysis (FIA) with amperometric detection, the resulting AChE-LDHs modified electrode greatly catalyzed the oxidation of the enzymatically generated thiocholine product, and facilitated the detection automation, thus increasing the detection sensitivity. The analytical conditions for the FIA/amperometric detection of OPs were optimized by using methyl parathion (MP) as a model. The inhibition of MP was proportional to its concentration ranging from 0.005 to 0.3μg mL(-1) and 0.3 to 4.0μg mL(-1) with a detection limit 0.6ng mL(-1) (S/N=3). The developed biosensor exhibited good reproducibility and acceptable stability.

  15. Oxime-mediated in vitro reactivation kinetic analysis of organophosphates-inhibited human and electric eel acetylcholinesterase.

    PubMed

    Sahu, Arvind Kumar; Sharma, Rahul; Gupta, Bhanushree; Musilek, Kamil; Kuca, Kamil; Acharya, Jyotiranjan; Ghosh, Kallol K

    2016-06-01

    Organophosphate (OP)-based pesticides and nerve agents are highly toxic compounds which interrupt the catalytic mechanism of acetylcholinesterase (AChE) by phosphorylating the hydroxyl moiety of serine residue. The inhibited enzyme can be reactivated by the nucleophilic action of oxime reactivators. To analyze the effect of different AChE sources on reactivation efficacy of reactivators, several in vivo studies have carried out using variety of AChE sources like pig, rat and monkey. Investigations on species differences provide a better insight for the development of new reactivators. Hence, present study was mainly targeted on comparative analysis of the reactivation of electric eel and human AChE inhibited by different OP. A series of butene-linked bis-pyridinium mono oximes which vary in functional groups present at the second pyridinium ring have been examined against sarin, VX, tabun and ethyl-paraoxon-poisoned AChE. In case of tabun-inhibited AChEs, tested oximes were better than reference oximes. For VX-poisoned human AChE, reactivator K251 (kr2;1.51 mM (-) (1 )min (-) (1)) showed good reactivation efficacy with standard oximes. Studies stipulated that butene-linked oximes consisting of different functional moieties are good reactivators and found to have better efficacy to reactivate nerve agent-inhibited human AChE in comparison to eel AChE. PMID:27101948

  16. Identification of a major Quantitative Trait Locus determining resistance to the organophosphate temephos in the dengue vector mosquito Aedes aegypti.

    PubMed

    Paiva, Marcelo H S; Lovin, Diane D; Mori, Akio; Melo-Santos, Maria A V; Severson, David W; Ayres, Constância F J

    2016-01-01

    Organophosphate insecticides (OP) have extensively been used to control mosquitoes, such as the vector Aedes aegypti. Unfortunately, OP resistance has hampered control programs worldwide. We used Quantitative Trait Locus (QTL) mapping to evaluate temephos resistance in two F1 intercross populations derived from crosses between a resistant Ae. aegypti strain (RecR) and two susceptible strains (MoyoD and Red). A single major effect QTL was identified on chromosome 2 of both segregating populations, named rtt1 (resistance to temephos 1). Bioinformatics analyses identified a cluster of carboxylesterase genes (CCE) within the rtt1 interval. qRT-PCR demonstrated that different CCEs were up-regulated in F2 resistant individuals from both crosses. However, none exceeded the 2-fold expression. Primary mechanisms for temephos resistance may vary between Ae. aegypti populations, yet also appear to support previous findings suggesting that multiple linked esterase genes may contribute to temephos resistance in the RecR strain as well as other populations.

  17. Performance assessment of the SOFA, APACHE II scoring system, and SAPS II in intensive care unit organophosphate poisoned patients.

    PubMed

    Kim, Yong Hwan; Yeo, Jung Hoon; Kang, Mun Ju; Lee, Jun Ho; Cho, Kwang Won; Hwang, SeongYoun; Hong, Chong Kun; Lee, Young Hwan; Kim, Yang Weon

    2013-12-01

    This study assessed the ability of the Sequential Organ Failure Assessment (SOFA) and Acute Physiology, Chronic Health Evaluation (APACHE) II scoring systems, as well as the Simplified Acute Physiology Score (SAPS) II method to predict group mortality in intensive care unit (ICU) patients who were poisoned with organophosphate. The medical records of 149 organophosphate poisoned patients admitted to the ICU from September 2006 to December 2012 were retrospectively examined. The SOFA, APACHE II, and SAPS II were calculated based on initial laboratory data in the Emergency Department, and during the first 24 hr of ICU admission. The probability of death was calculated for each patient based on the SOFA score, APACHE II score, and SAPS II equations. The ability to predict group mortality by the SOFA score, APACHE II score, and SAPS II method was assessed using two by two decision matrices and receiver operating characteristic (ROC) curve analysis. A total of 131 patients (mean age, 61 yr) were enrolled. The sensitivities, specificities, and accuracies were 86.2%, 82.4%, and 83.2% for the SOFA score, respectively; 65.5%, 68.6%, and 67.9% for the APACHE II scoring system, respectively; and 86.2%, 77.5%, and 79.4% for the SAPS II, respectively. The areas under the curve in the ROC curve analysis for the SOFA score, APACHE II scoring system, and SAPS II were 0.896, 0.716, and 0.852, respectively. In conclusion, the SOFA, APACHE II, and SAPS II have different capability to discriminate and estimate early in-hospital mortality of organophosphate poisoned patients. The SOFA score is more useful in predicting mortality, and easier and simpler than the APACHE II and SAPS II.

  18. Histopathological alterations, biochemical responses and acetylcholinesterase levels in Clarias gariepinus as biomarkers of exposure to organophosphates pesticides.

    PubMed

    Doherty, V F; Ladipo, M K; Aneyo, I A; Adeola, A; Odulele, W Y

    2016-05-01

    Organophosphate pesticides, commonly used in large scale farming, have been found to be major contaminants in aquatic environment. Clarias gariepinus was exposed to acute and sublethal concentrations of phostoxin and DD Force to evaluate single and joint action toxicity of the organophosphates. Effects of phostoxin and DD force on antioxidant enzymes, fish organs and acetylcholinesterase levels in fingerlings and juveniles of C. gariepinus were also investigated. The lethal concentrations (96 h LC50) for phostoxin and DD Force were 0.631 and 1.759 mg/l, respectively. The results obtained from the bioassay showed that phostoxin was 2.8× more toxic than DD Force after exposure of C. gariepinus. Joint action toxicity evaluations of phostoxin and DD Force showed that the interaction between the chemicals was synergistic (RTU >1). The biochemical responses in the exposed fish differed significantly (P < 0.05) from the control fish. The result of acetylcholinesterase study revealed significant difference between acetylcholinesterase levels in the exposed fish and control, with reduction in the acetylcholineterase level in fish exposed to sublethal concentrations of phostoxin and DD Force. Haematological studies revealed an increase in WBC, RBC, PCV and platelets in the exposed fish. Histopathology of the gills showed shortened primary lamellae, loss of secondary lamellae and loss of ceratobrachial bones. In the acute toxicity studies, respiratory stress, erratic swimming and instant death of fish were observed in the exposed fish. This study reveals that changes in histopathology and acetylcholinesterase level are good biomarkers and can be successfully used to detect exposure to organophosphates pesticides in fish. PMID:27121169

  19. Performance Assessment of the SOFA, APACHE II Scoring System, and SAPS II in Intensive Care Unit Organophosphate Poisoned Patients

    PubMed Central

    Kim, Yong Hwan; Yeo, Jung Hoon; Kang, Mun Ju; Cho, Kwang Won; Hwang, SeongYoun; Hong, Chong Kun; Lee, Young Hwan; Kim, Yang Weon

    2013-01-01

    This study assessed the ability of the Sequential Organ Failure Assessment (SOFA) and Acute Physiology, Chronic Health Evaluation (APACHE) II scoring systems, as well as the Simplified Acute Physiology Score (SAPS) II method to predict group mortality in intensive care unit (ICU) patients who were poisoned with organophosphate. The medical records of 149 organophosphate poisoned patients admitted to the ICU from September 2006 to December 2012 were retrospectively examined. The SOFA, APACHE II, and SAPS II were calculated based on initial laboratory data in the Emergency Department, and during the first 24 hr of ICU admission. The probability of death was calculated for each patient based on the SOFA score, APACHE II score, and SAPS II equations. The ability to predict group mortality by the SOFA score, APACHE II score, and SAPS II method was assessed using two by two decision matrices and receiver operating characteristic (ROC) curve analysis. A total of 131 patients (mean age, 61 yr) were enrolled. The sensitivities, specificities, and accuracies were 86.2%, 82.4%, and 83.2% for the SOFA score, respectively; 65.5%, 68.6%, and 67.9% for the APACHE II scoring system, respectively; and 86.2%, 77.5%, and 79.4% for the SAPS II, respectively. The areas under the curve in the ROC curve analysis for the SOFA score, APACHE II scoring system, and SAPS II were 0.896, 0.716, and 0.852, respectively. In conclusion, the SOFA, APACHE II, and SAPS II have different capability to discriminate and estimate early in-hospital mortality of organophosphate poisoned patients. The SOFA score is more useful in predicting mortality, and easier and simpler than the APACHE II and SAPS II. PMID:24339715

  20. Candidate OP Phyla: Importance, Ecology and Cultivation Prospects.

    PubMed

    Rohini Kumar, M; Saravanan, V S

    2010-10-01

    OP phyla were created in the domain bacteria, based on the group of 16S rRNA gene sequences recovered from the Obsidian Pool. However, due to the lack of cultured representative it is referred to as candidate phyla. Wider ecological occurrence was predicted for the OP phyla, especially OP3, OP10 and OP11. Recently, members of phylum OP5 and OP10 were cultured, providing clues to their cultivation prospects. At last the bioprospecting potentials of the OP members are discussed herein. PMID:22282618

  1. Candidate OP Phyla: Importance, Ecology and Cultivation Prospects.

    PubMed

    Rohini Kumar, M; Saravanan, V S

    2010-10-01

    OP phyla were created in the domain bacteria, based on the group of 16S rRNA gene sequences recovered from the Obsidian Pool. However, due to the lack of cultured representative it is referred to as candidate phyla. Wider ecological occurrence was predicted for the OP phyla, especially OP3, OP10 and OP11. Recently, members of phylum OP5 and OP10 were cultured, providing clues to their cultivation prospects. At last the bioprospecting potentials of the OP members are discussed herein.

  2. THE EFFECTS OF AN ORGANOPHOSPHATE (OP)-CARBAMATE (CB) PESTICIDE MIXTURE ON CORE TEMPERATURE AND MOTOR ACTIVITY IN THE RAT.

    EPA Science Inventory

    Pesticide risk assessment has traditionally been based on the toxicological response to single agents. Dose-additivity has been the default in risk assessment evaluations of pesticides with a common mechanism of action, but there could be supra-additive or infra-additive inter...

  3. Structure-Based and Random Mutagenesis Approaches Increase the Organophosphate-Degrading Activity of a Phosphotriesterase Homologue from Deinococcus radiodurans

    SciTech Connect

    Hawwa, Renda; Larsen, Sonia D.; Ratia, Kiira; Mesecar, Andrew D.

    2010-11-09

    An enzyme from the amidohydrolase family from Deinococcus radiodurans (Dr-OPH) with homology to phosphotriesterase has been shown to exhibit activity against both organophosphate (OP) and lactone compounds. We have characterized the physical properties of Dr-OPH and have found it to be a highly thermostable enzyme, remaining active after 3 h of incubation at 60 C and withstanding incubation at temperatures up to 70 C. In addition, it can withstand concentrations of at least 200 mg/mL. These properties make Dr-OPH a promising candidate for development in commercial applications. However, compared to the most widely studied OP-degrading enzyme, that from Pseudomonas diminuta, Dr-OPH has low hydrolytic activity against certain OP substrates. Therefore, we sought to improve the OP-degrading activity of Dr-OPH, specifically toward the pesticides ethyl and methyl paraoxon, using structure-based and random approaches. Site-directed mutagenesis, random mutagenesis, and site-saturation mutagenesis were utilized to increase the OP-degrading activity of Dr-OPH. Out of a screen of more than 30,000 potential mutants, a total of 26 mutant enzymes were purified and characterized kinetically. Crystal structures of w.t. Dr-OPH, of Dr-OPH in complex with a product analog, and of 7 mutant enzymes were determined to resolutions between 1.7 and 2.4 {angstrom}. Information from these structures directed the design and production of 4 additional mutants for analysis. In total, our mutagenesis efforts improved the catalytic activity of Dr-OPH toward ethyl and methyl paraoxon by 126- and 322-fold and raised the specificity for these two substrates by 557- and 183-fold, respectively. Our work highlights the importance of an iterative approach to mutagenesis, proving that large rate enhancements are achieved when mutations are made in already active mutants. In addition, the relationship between the kinetic parameters and the introduced mutations has allowed us to hypothesize on those

  4. Influence of CYP2C9, GSTM1, GSTT1 and NAT2 genetic polymorphisms on DNA damage in workers occupationally exposed to organophosphate pesticides.

    PubMed

    Singh, Satyender; Kumar, Vivek; Singh, Priyanka; Banerjee, Basu Dev; Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen; Jain, Sudhir Kumar; Rai, Arvind

    2012-01-24

    Previous studies have revealed that organophosphate pesticides (OPs) are primarily metabolized by xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticides-exposed workers. Present study was designed to determine the influence of CYP2C9, GSTM1, GSTT1 and NAT2 genetic polymorphisms on DNA damage in workers occupationally exposed to OPs. We examined 268 subjects including 134 workers occupationally exposed to OPs and an equal number of normal healthy controls. The DNA damage was evaluated using alkaline comet assay and genotyping was done using individual polymerase chain reaction (PCR) or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Acetylcholinesterase and paraoxonase activity were found to be significantly lowered in workers as compared to control subjects which were analyzed as biomarkers of toxicity due to OPs exposure (p<0.001). Workers showed significantly higher DNA tail moment (TM) compared to control subjects (14.32±2.17 vs. 6.24±1.37 tail % DNA, p<0.001). GSTM1 null genotype was found to influence DNA TM in workers (p<0.05). DNA TM was also found to be increased with concomitant presence of NAT2 slow acetylation and CYP2C9*3/*3 or GSTM1 null genotypes (p<0.05). DNA TM was found increased in NAT2 slow acetylators with mild and heavy smoking habits in control subjects and workers, respectively (p<0.05). The results of this study suggest that GSTM1 null genotypes, and an association of NAT2 slow acetylation genotypes with CYP2C9*3/*3 or GSTM1 null genotypes may modulate DNA damage in workers occupationally exposed to OPs.

  5. Enzymatic reaction modulated gold nanorod end-to-end self-assembly for ultrahigh sensitively colorimetric sensing of cholinesterase and organophosphate pesticides in human blood.

    PubMed

    Lu, Linlin; Xia, Yunsheng

    2015-08-18

    We present herein the first reported self-assembly modulation of gold nanorods (AuNRs) by enzymatic reaction, which is further employed for colorimetric assays of cholinesterase (ChE) and organophosphate pesticides (OPs) in human blood. ChE catalyzes its substrate (acetylthiocholine) and produces thiocholine and acetate acid. The resulting thiols then react with the tips of the AuNRs by S-Au conjunction and prevent subsequent cysteine-induced AuNR end-to-end (EE) self-assembly. Correspondingly, the AuNR surface plasmon resonance is regulated, which results in a distinctly ratiometric signal output. Under optimal conditions, the linear range is 0.042 to 8.4 μU/mL, and the detection limit is as low as 0.018 μU/mL. As ChE is incubated with OPs, the enzymatic activity is inhibited. So, the cysteine-induced assembly is observed again. On the basis of this principle, OPs can be well determined ranging from 0.12 to 40 pM with a 0.039 pM detection limit. To our knowledge, the present quasi pU/mL level sensitivity for ChE and the quasi femtomolar level sensitivity for OPs are at least 500 and 7000 times lower than those of previous colorimetric methods, respectively. The ultrahigh sensitivity results from (1) the rational choice of anisotropic AuNRs as building blocks and reporters and (2) the specific structure of the enzymatic thiocholine. Because of ultrahigh sensitivity, serum samples are allowed to be extremely diluted in the assay. Accordingly, various nonspecific interactions, even from glutathione/cysteine, are well avoided. So, both ChE and OPs in human blood can be directly assayed without any prepurification, indicating the simplicity and practical promise of the proposed method.

  6. Organophosphate Insecticide Metabolites in Prenatal and Childhood Urine Samples and Intelligence Scores at 6 Years of Age: Results from the Mother–Child PELAGIE Cohort (France)

    PubMed Central

    Cartier, Chloé; Warembourg, Charline; Le Maner-Idrissi, Gaïd; Lacroix, Agnès; Rouget, Florence; Monfort, Christine; Limon, Gwendolina; Durand, Gaël; Saint-Amour, Dave; Cordier, Sylvaine; Chevrier, Cécile

    2015-01-01

    Background: Several studies suggest that exposure to organophosphate insecticides (OP) during pregnancy impairs neurodevelopment in children. Objectives: We evaluated associations between biomarkers of prenatal and postnatal OP exposure and cognitive function of 6-year-olds in a French longitudinal birth cohort. Methods: In 2002–2006, the PELAGIE mother–child cohort enrolled pregnant women from Brittany. For a random subcohort, we measured nonspecific dialkylphosphate metabolites (DAP) of OP in one maternal urine sample, collected before 19 weeks’ gestation, and in one urine sample collected from their 6-year-old children. Six subtests of the Wechsler Intelligence Scale for Children, 4th edition (WISC-IV) were administered when the children were 6 years of age to evaluate cognitive function (n = 231). Linear regression models controlling for factors including maternal intelligence and the Home Observation for Measurement of the Environment score were used. Results: WISC-IV scores were not significantly associated with prenatal or childhood total DAP metabolites. WISC verbal comprehension score was significantly higher in association with the highest maternal urinary concentrations of diethylphosphate (DE) metabolites (5.5; 95% CI: 0.8, 10.3 for > 13.2 nmol/L vs. < LOQ), whereas WISC working memory score was significantly lower in association with the highest urinary concentrations of DE metabolites at age 6 years (–3.6; 95% CI: –7.8, –0.6 for > 11.1 nmol/L vs. < LOD). Conclusion: We found no evidence that prenatal OP exposure adversely affected cognitive function in 6-year-olds, perhaps because of the population’s socioeconomic status, which was higher than in previous studies, though other causal and noncausal explanations are also possible. The negative association between WISC score and concurrent DE urinary concentrations requires replication by longitudinal studies investigating childhood OP exposure. Citation: Cartier C, Warembourg C, Le Maner

  7. Cumulative organophosphate pesticide exposure and risk assessment among pregnant women living in an agricultural community: a case study from the CHAMACOS cohort.

    PubMed Central

    Castorina, Rosemary; Bradman, Asa; McKone, Thomas E; Barr, Dana B; Harnly, Martha E; Eskenazi, Brenda

    2003-01-01

    Approximately 230,000 kg of organophosphate (OP) pesticides are applied annually in California's Salinas Valley. These activities have raised concerns about exposures to area residents. We collected three spot urine samples from pregnant women (between 1999 and 2001) enrolled in CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas), a longitudinal birth cohort study, and analyzed them for six dialkyl phosphate metabolites. We used urine from 446 pregnant women to estimate OP pesticide doses with two deterministic steady-state modeling methods: method 1, which assumed the metabolites were attributable entirely to a single diethyl or dimethyl OP pesticide; and method 2, which adapted U.S. Environmental Protection Agency (U.S. EPA) draft guidelines for cumulative risk assessment to estimate dose from a mixture of OP pesticides that share a common mechanism of toxicity. We used pesticide use reporting data for the Salinas Valley to approximate the mixture to which the women were exposed. Based on average OP pesticide dose estimates that assumed exposure to a single OP pesticide (method 1), between 0% and 36.1% of study participants' doses failed to attain a margin of exposure (MOE) of 100 relative to the U.S. EPA oral benchmark dose(10) (BMD(10)), depending on the assumption made about the parent compound. These BMD(10) values are doses expected to produce a 10% reduction in brain cholinesterase activity compared with background response in rats. Given the participants' average cumulative OP pesticide dose estimates (method 2) and regardless of the index chemical selected, we found that 14.8% of the doses failed to attain an MOE of 100 relative to the BMD(10) of the selected index. An uncertainty analysis of the pesticide mixture parameter, which is extrapolated from pesticide application data for the study area and not directly quantified for each individual, suggests that this point estimate could range from 1 to 34%. In future analyses, we

  8. Comparative study on short- and long-term behavioral consequences of organophosphate exposure: relationship to AChE mRNA expression.

    PubMed

    López-Granero, Caridad; Cardona, Diana; Giménez, Estela; Lozano, Rafael; Barril, José; Aschner, Michael; Sánchez-Santed, Fernando; Cañadas, Fernando

    2014-01-01

    Organophosphates (OPs) affect behavior by inhibiting acetylcholinesterase (AChE). While the cognitive short-term effects may be directly attributed to this inhibition, the mechanisms that underlie OP's long-term cognitive effects remain controversial and poorly understood. Accordingly, two experiments were designed to assess the effects of OPs on cognition, and to ascertain whether both the short- and long-term effects of are AChE-dependent. A single subcutaneous dose of 250 mg/kg chlorpyrifos (CPF), 1.5mg/kg diisopropylphosphorofluoridate (DFP) or 15 mg/kg parathion (PTN) was administered to male Wistar rats. Spatial learning was evaluated 72 h or 23 weeks after exposure, and impulsive choice was tested at 10 and 30 weeks following OPs administration (experiment 1 and 2, respectively). Brain soluble and membrane-bound AChE activity, synaptic AChE-S mRNA, read-through AChE-R mRNA and brain acylpeptide hydrolase (APH) activity (as alternative non-cholinergic target) were analyzed upon completion of the behavioral testing (17 and 37 weeks after OPs exposure). Both short- and long-term CPF treatment caused statistically significant effects on spatial learning, while PTN treatment led only to statistically significant short-term effects. Neither CPF, DFP nor PTN affected the long-term impulsivity response. Long-term exposure to CPF and DFP significantly decreased AChE-S and AChE-R mRNA, while in the PTN treated group only AChE-S mRNA levels were decreased. However, after long-term OP exposure, soluble and membrane-bound AChE activity was indistinguishable from controls. Finally, no changes were noted in brain APH activity in response to OP treatment. Taken together, this study demonstrates long-term effects of OPs on AChE-S and AChE-R mRNA in the absence of changes in AChE soluble and membrane-bound activity. Thus, changes in AChE mRNA expression imply non-catalytic properties of the AChE enzyme.

  9. Development of an autofluorescent whole-cell biocatalyst by displaying dual functional moieties on Escherichia coli cell surfaces and construction of a coculture with organophosphate-mineralizing activity .

    PubMed

    Yang, Chao; Zhu, Yaran; Yang, Jijian; Liu, Zheng; Qiao, Chuanling; Mulchandani, Ashok; Chen, Wilfred

    2008-12-01

    Surface display of the active proteins on living cells has enormous potential in the degradation of numerous toxic compounds. Here, we report the codisplay of organophosphorus hydrolase (OPH) and enhanced green fluorescent protein (GFP) on the cell surface of Escherichia coli by use of the truncated ice nucleation protein (INPNC) and Lpp-OmpA fusion systems. The surface localization of both INPNC-OPH and Lpp-OmpA-GFP was demonstrated by Western blot analysis, immunofluorescence microscopy, and a protease accessibility experiment. Anchorage of GFP and OPH on the outer membrane neither inhibits cell growth nor affects cell viability, as shown by growth kinetics of cells and stability of resting cultures. The engineered E. coli can be applied in the form of a whole-cell biocatalyst and can be tracked by fluorescence during bioremediation. This strategy of codisplay should open a new dimension for the display of multiple functional moieties on the surface of a bacterial cell. Furthermore, a coculture comprised of the engineered E. coli and a natural p-nitrophenol (PNP) degrader, Ochrobactrum sp. strain LL-1, was assembled for complete mineralization of organophosphates (OPs) with a PNP substitution. The coculture degraded OPs as well as PNP rapidly. Therefore, the coculture with autofluorescent and mineralizing activities can potentially be applied for bioremediation of OP-contaminated sites. PMID:18952884

  10. Microbiological and biotechnological aspects of metabolism of carbamates and organophosphates.

    PubMed

    Chapalamadugu, S; Chaudhry, G R

    1992-01-01

    Several carbamate and organophosphate compounds are used to control a wide variety of insect pests, weeds, and disease-transmitting vectors. These chemicals were introduced to replace the recalcitrant and hazardous chlorinated pesticides. Although newly introduced pesticides were considered to be biodegradable, some of them are highly toxic and their residues are found in certain environments. In addition, degradation of some of the carbamates generates metabolites that are also toxic. In general, hydrolysis of the carbamate and organophosphates yields less toxic metabolites compared with the metabolites produced from oxidation. Although microorganisms capable of degrading many of these pesticides have been isolated, knowledge about the biochemical pathways and respective genes involved in the degradation is sparse. Recently, a great deal of interest in the mechanisms of biodegradation of carbamate and organophosphate compounds has been shown because (1) an efficient mineralization of the pesticides used for insect control could eliminate the problems of environmental pollution, (2) a balance between degradation and efficacy of pesticides could result in safer application and effective insect control, and (3) knowledge about the mechanisms of biodegradation could help to deal with situations leading to the generation of toxic metabolites and bioremediation of polluted environments. In addition, advances in genetic engineering and biotechnology offer great potential to exploit the degradative properties of microorganisms in order to develop bioremediation strategies and novel applications such as development of economic plants tolerant to herbicides. In this review, recent advances in the biochemical and genetic aspects of microbial degradation of carbamate and organophosphates are discussed and areas in need of further investigation identified.

  11. Piezoelectric Biosensors for Organophosphate and Carbamate Pesticides: A Review

    PubMed Central

    Marrazza, Giovanna

    2014-01-01

    Due to the great amount of pesticides currently being used, there is an increased interest for developing biosensors for their detection. Among all the physical transducers, piezoelectric systems have emerged as the most attractive due to their simplicity, low instrumentation costs, possibility for real-time and label-free detection and generally high sensitivity. This paper presents an overview of biosensors based on the quartz crystal microbalance, which have been reported in the literature for organophosphate and carbamate pesticide analysis. PMID:25587424

  12. Action of organophosphates on the electroretinogram of rainbow trout.

    PubMed

    Kreft, W D; Hoffert, J R; Fromm, P O

    1985-01-01

    Electroretinograms (ERGs) were recorded in vitro from eyes of rainbow trout that had received intraperitoneal injections of either TOCP (triorthocresyl phosphate) or DEF (S, S, S-tributyl phosphorotrithioate). Data obtained after 24 h indicated that these organophosphates caused alterations in four of five ERG parameters in the case of TOCP and all five parameters in the DEF treated specimens. These data were compared with data obtained from experiments with eserine and carbachol and led to the conclusion that the effects of the organophosphates on the retina were independent of any cholinesterase inhibitor activity of the compounds. These organophosphates affect (a) the non-cholinergic photoreceptor layer of the retina which produces the a-wave ERG component, and (b) the other neural layers of the retina known to be responsible for generation of the b-wave component. Based on data obtained 15 days after exposure there was no evidence that TOCP or DEF has any delayed neurotoxic effect on the retina of rainbow trout.

  13. Prevalence of tinnitus in workers exposed to noise and organophosphates

    PubMed Central

    Delecrode, Camila Ribas; de Freitas, Thais Domingues; Frizzo, Ana Claúdia Figueiredo; Cardoso, Ana Claúdia Vieira

    2012-01-01

    Summary Introduction: Research on the workplace has emphasized the effects of noise exposure on workers' hearing, but has not considered the effects of agrochemicals. Aim: To evaluate and correlate the hearing level and tinnitus of workers exposed simultaneously to noise and organophosphates in their workplace and to measure tinnitus distress on their quality of life. Method: A retrospective clinical study. We evaluated 82 organophosphate sprinklers from the São Paulo State Regional Superintendence who were active in the fight against dengue and who were exposed to noise and organophosphates. We performed pure tone audiometry and applied the translated THI (Tinnitus Handicap Inventory) questionnaire. Results: Of the sample, 28.05% reported current tinnitus or had presented tinnitus, and the workers with tinnitus had an increased incidence of abnormal audiometry. The average hearing threshold for the 4–8-kHz frequency range of the workers with current tinnitus was higher than that of the others, and was most affected at the 4-kHz frequency. The THI score ranged 0–84, with an average score of 13.1. Twelve (52.17%) workers had THI scores consistent with discrete handicap. Conclusion: There is an increased incidence of abnormal pure tone audiometry in workers with tinnitus, and its impact on the workers' quality of life was discrete. The correlation between average hearing threshold and tinnitus distress was weak. PMID:25991953

  14. Gas co-ops pose solution, problems

    SciTech Connect

    Haines, L.

    1995-10-01

    Gas co-ops can give smaller producers advantages of scale, but they also will add cost and complexity to the work loads of their members. The biggest argument for co-ops is the economics of scale that large volumes bring. Even with that advantage, gas marketing margins have slimmed considerably, prompting a rash of mergers among the marketing-gathering companies and between producers and pipelines.

  15. An unusual case of organophosphate intoxication of a worker in a plastic bottle recycling plant: an important reminder.

    PubMed

    Wang, C L; Chuang, H Y; Chang, C Y; Liu, S T; Wu, M T; Ho, C K

    2000-11-01

    A young man was sent to our emergency unit because he had suffered from vomiting and cold sweating for 2 days. At the time he was admitted, he had no acute abdominal pains or gastrointestinal symptoms, and a physical examination revealed nothing but a faster heart rate and moist, flushing skin. The patient had worked for 6 years at a plastic bottle-recycling factory, but none of his co-workers had the same symptoms. Nevertheless, because the plant also recycled pesticide bottles, we suspected organophosphate pesticide intoxication. The patient's plasma acetylcholinesterase level was checked, revealing 1498.6 microU/L (normal range: 2,000-5, 000) on the first day and 1,379 microU/L on the second day. Upon questioning, the patient recalled that one of his shoe soles had been damaged and that his foot had been wet from walking all day in rain collected on the factory floor on the day that his symptoms first occurred. We conducted a study in the change of preshift and postshift acetylcholinesterase levels among six of his co-workers on a rainy day. We used the Wilcoxon signed rank test to compare the preshift and postshift plasma acetylcholinesterase levels; no significant difference was revealed (p = 0.600), leaving contamination via the damaged shoe sole suspect. We reviewed the literature on organophosphate intoxication; pesticide bottle-recycling factories were reported to be at a low risk of organophosphate toxicity in the working environment. However, because the potential risk of intoxication is still present, protective equipment such as clothing, gloves, and water-proof shoes should be worn, and employees should be educated on the potential risks.

  16. Detection and location of OP-degrading activity: A model to integrate education and research.

    PubMed

    Iyer, Rupa; Smith, Kevin; Kudrle, Bill; Leon, Alex

    2015-06-25

    The Environmental Sampling Research Module (ESRM) is an investigative/discovery module that provides undergraduate research experiences for students as part of an interdisciplinary research-based biotechnology curriculum at the University of Houston campus. As part of the ESRM, students collect soil samples from various locations to test for the presence of organophosphorous (OP) degrading bacteria. At the end of this research project students submit a research paper on their field and laboratory activities and discuss their experimental data and observations. Students also record the date, location of collection, and the results of testing the sample for the degradation of two pesticides, methyl parathion or paraoxon, in an electronic laboratory notebook (ELN). Each collection site is recorded on a Google Maps module and the data from student research activities is made available to other undergraduate students. This data is then used to generate a microorganism database of pesticide degrading activity and promote reading, critical thinking, and analytical skills as part of the curriculum. Our sampling of agricultural sites and wastewater within and around the city of Houston has identified seven distinct genera of OP degrading organisms, including Pseudomonas, Stenotrophomonas, Exiguobacterium, Delftia, Agrobacterium, Aeromonas, and Rhizobium. Collected strains exhibit phosphotriesterase-like enzymatic activity with isolates of Pseudomonas putida and Stenotrophomonas maltophilia capable of degrading both the phosphotriester paraoxon and the phosphorothioate methyl parathion. Using this collection of OP-degrading microorganisms, undergraduate students have evaluated their potential for enhancing the removal of harmful organophosphates and their toxic metabolites from contaminated agricultural soil and adjacent bodies of water. This analytical data can potentially be utilized for environmental and industrial applications in bioremediation and ecology providing an

  17. Factors predicting trust between GPs and OPs

    PubMed Central

    Nauta, A.P.; von Grumbkow, J.

    2001-01-01

    Abstract Purpose To study possible differences in trust between general practitioners (GPs) and occupational physicians (OPs) and the explanatory factors for trust. Insight into the factors predicting trust can improve programmes for stimulating the co-operation of GPs and OPs. Theory On the basis of theories of trust and of social identity theory we expected, (1) in both professions a higher level of knowledge-based trust than of identification-based trust, (2) a relationship between higher levels of identification-based trust and higher frequency of contact, (3) OPs to have a higher level of identification-based trust than GPs. We hypothesised (4) that OPs perceiving an equal status have higher levels of trust and (5) GPs perceiving a higher status have lower levels of trust. Methods A mail survey sent to 2297 doctors (1728 GPs and 569 OPs) of which we used 547 questionnaires. Results Hypotheses 1 and 2 were supported. Hypothesis 3 was not supported. Hypotheses 4 and 5 were supported for knowledge-based trust. On the basis of these findings it is possible that co-operation between the two groups is still in its early stages. Conclusions Programmes to improve the co-operation of GPs and OPs should focus on equalising status and stimulating contacts to build (identification-based) trust. PMID:16896412

  18. Blood acylpeptide hydrolase activity is a sensitive marker for exposure to some organophosphate toxicants.

    PubMed

    Quistad, Gary B; Klintenberg, Rebecka; Casida, John E

    2005-08-01

    Acylpeptide hydrolase (APH) unblocks N-acetyl peptides. It is a major serine hydrolase in rat blood, brain, and liver detected by derivatization with (3)H-diisopropyl fluorophosphate (DFP) or a biotinylated fluorophosphonate. Although APH does not appear to be a primary target of acute poisoning by organophosphorus (OP) compounds, the inhibitor specificity of this secondary target is largely unknown. This study fills the gap and emphasizes blood APH as a potential marker of OP exposure. The most potent in vitro inhibitors for human erythrocyte and mouse brain APH are DFP (IC(50) 11-17 nM), chlorpyrifos oxon (IC(50) 21-71 nM), dichlorvos (IC(50) 230-560 nM), naled (IC(50) 370-870 nM), and their analogs with modified alkyl substituents. (3)H-diisopropyl fluorophosphate is a potent inhibitor of mouse blood and brain APH in vivo (ED(50) 0.09-0.2 mg/kg and 0.02-0.03 mg/l for ip and vapor exposure, respectively). Mouse blood and brain APH and blood butyrylcholinesterase (BChE) are of similar sensitivity to DFP in vitro and in vivo (ip and vapor exposure), but APH inhibition is much more persistent in vivo (still >80% inhibition after 4 days). The inhibitory potency of OP pesticides in vivo in mice varies from APH selective (dichlorvos, naled, and trichlorfon), to APH and BChE selective (profenofos and tribufos), to ChE selective or nonselective (many commercial insecticides). Sarin administered ip at a lethal dose to guinea pigs inhibits blood acetylcholinesterase and BChE completely but erythrocyte APH only partially. Blood APH activity is therefore a sensitive marker for exposure to some but not all OP pesticides and chemical warfare agents. PMID:15888665

  19. In Vitro Rat Hepatic and Intestinal Metabolism of the Organophosphate Pesticides Chlorpyrifos and Diazinon

    SciTech Connect

    Poet, Torka S. ); Wu, Hong ); Kousba, Ahmed A. ); Timchalk, Charles

    2003-04-01

    Chlorpyrifos (CPF) and diazinon (DZN) are thionophosphorus organophosphate, insecticides; their toxicity is mediated through CYP450 metabolism to CPF-oxon and DZN-oxon, respectively. Conversely, CYP450s also detoxify these OPs to trichloropyridinol (TCP) and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMHP), respectively. In addition, A-esterase metabolism of CPF- and DZN-oxon also form TCP and IMHP. This study evaluated the role intestinal and hepatic metabolism may play in the first-pass elimination of CPF and DZN. Similar CYP450- and A-esterase-mediated metabolic profiles were demonstrated in microsomes from liver or isolated intestinal enterocytes. In enterocyte microsomes, the CYP450 metabolic efficiency (Vmax/Km) for metabolism to the oxon metabolites was~5-fold greater for CPF than DZN. Compared on a per nmol P450 basis, the Vmax for CPF in enterocytes was~2-3 times higher than in liver microsomes for the production of CPF-oxon and TCP. The affinity (Km) for the metabolism of CPF to CPF-oxon was comparable in liver and enterocyte microsomes, however the enterocyte Km for TCP production was higher (lower affinity). The smaller volume of intestine, lower amount of CYP450, and higher Km for TCP in the enterocyte microsomes, resulted in a lower catalytic efficiency (2 and 62 times) than in liver for oxon and TCP. A-esterase-mediated metabolism of CPF- and DZN-oxon was also demonstrated in liver and enterocyte microsomes. Although A-esterase affinity for the substrates were comparable in hepatic and enterocyte microsomes, the Vmax were 48 - to 275-fold, in the liver. These results suggest that intestinal metabolism may impact first-pass metabolism of CPF and DZN, especially following low-dose oral exposures.

  20. Enhancing enzyme stability by construction of polymer-enzyme conjugate micelles for decontamination of organophosphate agents.

    PubMed

    Suthiwangcharoen, Nisaraporn; Nagarajan, Ramanathan

    2014-04-14

    Enhancing the stability of enzymes under different working environments is essential if the potential of enzyme-based applications is to be realized for nanomedicine, sensing and molecular diagnostics, and chemical and biological decontamination. In this study, we focus on the enzyme, organophosphorus hydrolase (OPH), which has shown great promise for the nontoxic and noncorrosive decontamination of organophosphate agents (OPs) as well as for therapeutics as a catalytic bioscavanger against nerve gas poisoning. We describe a facile approach to stabilize OPH using covalent conjugation with the amphiphilic block copolymer, Pluronic F127, leading to the formation of F127-OPH conjugate micelles, with the OPH on the micelle corona. SDS-PAGE and MALDI-TOF confirmed the successful conjugation, and transmission electron microscopy (TEM) and dynamic light scattering (DLS) revealed ∼100 nm size micelles. The conjugates showed significantly enhanced stability and higher activity compared to the unconjugated OPH when tested (i) in aqueous solutions at room temperature, (ii) in aqueous solutions at higher temperatures, (iii) after multiple freeze/thaw treatments, (iv) after lyophilization, and (v) in the presence of organic solvents. The F127-OPH conjugates also decontaminated paraoxon (introduced as a chemical agent simulant) on a polystyrene film surface and on a CARC (Chemical Agent Resistant Coating) test panel more rapidly and to a larger extent compared to free OPH. We speculate that, in the F127-OPH conjugates (both in the micellar form as well as in the unaggregated conjugate), the polypropylene oxide block of the copolymer interacts with the surface of the OPH and this confinement of the OPH reduces the potential for enzyme denaturation and provides robustness to OPH at different working environments. The use of such polymer-enzyme conjugate micelles with improved enzyme stability opens up new opportunities for numerous civilian and Warfighter applications.

  1. Chemotaxis and degradation of organophosphate compound by a novel moderately thermo-halo tolerant Pseudomonas sp. strain BUR11: evidence for possible existence of two pathways for degradation.

    PubMed

    Pailan, Santanu; Saha, Pradipta

    2015-01-01

    An organophosphate (OP) degrading chemotactic bacterial strain BUR11 isolated from an agricultural field was identified as a member of Pseudomonas genus on the basis of its 16S rRNA gene sequence. The strain could utilize parathion, chlorpyrifos and their major hydrolytic intermediates as sole source of carbon for its growth and exhibited positive chemotactic response towards most of them. Optimum concentration of parathion for its growth was recorded to be 200 ppm and 62% of which was degraded within 96 h at 37 °C. Growth studies indicated the strain to be moderately thermo-halo tolerant in nature. Investigation based on identification of intermediates of parathion degradation by thin layer chromatography (TLC), high performance liquid chromatography (HPLC), gas chromatography (GC) and liquid chromatography mass spectrometry (LC-MS/MS) provided evidence for possible existence of two pathways. The first pathway proceeds via 4-nitrophenol (4-NP) while the second proceeds through formation of 4-aminoparathion (4-APar), 4-aminophenol (4-AP) and parabenzoquinone (PBQ). This is the first report of chemotaxis towards organophosphate compound by a thermo-halo tolerant bacterium. PMID:26587344

  2. Chemotaxis and degradation of organophosphate compound by a novel moderately thermo-halo tolerant Pseudomonas sp. strain BUR11: evidence for possible existence of two pathways for degradation

    PubMed Central

    Pailan, Santanu

    2015-01-01

    An organophosphate (OP) degrading chemotactic bacterial strain BUR11 isolated from an agricultural field was identified as a member of Pseudomonas genus on the basis of its 16S rRNA gene sequence. The strain could utilize parathion, chlorpyrifos and their major hydrolytic intermediates as sole source of carbon for its growth and exhibited positive chemotactic response towards most of them. Optimum concentration of parathion for its growth was recorded to be 200 ppm and 62% of which was degraded within 96 h at 37 °C. Growth studies indicated the strain to be moderately thermo-halo tolerant in nature. Investigation based on identification of intermediates of parathion degradation by thin layer chromatography (TLC), high performance liquid chromatography (HPLC), gas chromatography (GC) and liquid chromatography mass spectrometry (LC-MS/MS) provided evidence for possible existence of two pathways. The first pathway proceeds via 4-nitrophenol (4-NP) while the second proceeds through formation of 4-aminoparathion (4-APar), 4-aminophenol (4-AP) and parabenzoquinone (PBQ). This is the first report of chemotaxis towards organophosphate compound by a thermo-halo tolerant bacterium. PMID:26587344

  3. The CO-OP Guide

    SciTech Connect

    Michael, J.; /Fermilab

    1991-08-16

    You are at D0, the newest and most advanced experiment at Fermilab. Its goal is to find the 'top quark', nicknamed 'truth'. theoretically one of the six fundamental building blocks of matter. Combinations of the six quarks are said to make up electrons, protons and neutrons. Your group at D0 is the cryogenic division. Its goal is to provide and maintain a cryogenic system which ultimately supplies and controls the liquid argon used in the giant cryostats for the experiment. The high purity liquid argon is needed to keep the detector modules inside the cryostats cold, so that they will operate properly. Your job at D0 is to be a co-op for the research and development group of the cryogenics division. Your goals are dependent on the needs of the cryo group. D0 is where you will spend most of your time. The co-op office is located on what is known as the 3rd floor, but is actually on the ground floor. The floor directly above the 3rd floor is the 5th floor, which contains your immediate superiors and the D0 secretary. The 6th and top floor is above that, and contains the D0 secretary for official and important business. On the other side of the D0 assembly building is the cryo control room. This is where the cryogenic piping system is remotely monitored and controlled. Other important sites at D0 include the trailer city on the north parking lot, which has the D0 secretary who handles all the payroll matters (among other duties), and the portakamp in the south parking lot. Besides D0, which is named for its location on the particle accelerator ring. the most important place is Wilson Hall. That is the large building shaped like a big Atact symbol. It contains various important people such as the safety group. the personnel department (which you have already encountered. being hired), the minor stock room, the cafeteria, the Fermi library. Ramsey Auditorium. etc. Behind Wilson Hall is the Booster Ring, which accelerates particles before they are injected into the main

  4. Associations of maternal organophosphate pesticide exposure and PON1 activity with birth outcomes in SAWASDEE birth cohort, Thailand.

    PubMed

    Naksen, Warangkana; Prapamontol, Tippawan; Mangklabruks, Ampica; Chantara, Somporn; Thavornyutikarn, Prasak; Srinual, Niphan; Panuwet, Parinya; Ryan, P Barry; Riederer, Anne M; Barr, Dana Boyd

    2015-10-01

    Prenatal organophosphate (OP) pesticide exposure has been reported to be associated with adverse birth outcomes and neurodevelopment. However, the mechanisms of toxicity of OP pesticides on human fetal development have not yet been elucidated. Our pilot study birth cohort, the Study of Asian Women and Offspring's Development and Environmental Exposures (SAWASDEE cohort) aimed to evaluate environmental chemical exposures and their relation to birth outcomes and infant neurodevelopment in 52 pregnant farmworkers in Fang district, Chiang Mai province, Thailand. A large array of data was collected multiple times during pregnancy including approximately monthly urine samples for evaluation of pesticide exposure, three blood samples for pesticide-related enzyme measurements and questionnaire data. This study investigated the changes in maternal acetylcholinesterase (AChE) and paraoxonase 1 (PON1) activities and their relation to urinary diakylphosphates (DAPs), class-related metabolites of OP pesticides, during pregnancy. Maternal AChE, butyrylcholinesterase (BChE) and PON1 activities were measured three times during pregnancy and urinary DAP concentrations were measured, on average, 8 times from enrollment during pregnancy until delivery. Among the individuals in the group with low maternal PON1 activity (n=23), newborn head circumference was negatively correlated with log10 maternal ∑DEAP and ∑DAP at enrollment (gestational age=12±3 weeks; β=-1.0 cm, p=0.03 and β=-1.8 cm, p<0.01, respectively) and at 32 weeks pregnancy (β=-1.1cm, p=0.04 and β=-2.6 cm, p=0.01, respectively). Furthermore, among these mothers, newborn birthweight was also negatively associated with log10 maternal ∑DEAP and ∑DAP at enrollment (β=-219.7 g, p=0.05 and β=-371.3g, p=0.02, respectively). Associations between maternal DAP levels and newborn outcomes were not observed in the group of participants with high maternal PON1 activity. Our results support previous findings from US birth

  5. A single method for detecting 11 organophosphate pesticides in human plasma and breastmilk using GC-FPD.

    PubMed

    Naksen, Warangkana; Prapamontol, Tippawan; Mangklabruks, Ampica; Chantara, Somporn; Thavornyutikarn, Prasak; Robson, Mark G; Ryan, P Barry; Barr, Dana Boyd; Panuwet, Parinya

    2016-07-01

    Organophosphate (OP) pesticides are widely used for crop protection in many countries including Thailand. Aside from causing environmental contamination, they affect human health especially by over-stimulating of the neurotransmission system. OP pesticides, as with other non-persistent pesticides, degrade quickly in the environment as well as are metabolized quite rapidly in humans. Assessing human exposures to these compounds requires analytical methods that are sensitive, robust, and most importantly, suitable for specific laboratory settings. The aim of this study was to develop and validate an analytical method for measuring 11 OP pesticide residues in human plasma and breast milk. Analytes in both plasma and breast milk samples were extracted with acetone and methylene chloride, cleaned-up using aminopropyl solid phase extraction cartridges, and analyzed by gas chromatography with flame photometric detection. The optimized method exhibited good linearity, with the coefficients of determination of 0.996-0.999 and <7% error about the slope. Extraction recoveries from spiked plasma and breast milk samples at low and medium concentrations (0.8-5.0 and 1.6-10ngmL(-1), respectively) ranged from 59.4% (ethion) to 94.0% (chlorpyrifos). Intra-batch and inter-batch precisions ranged from 2.3-18.9% and 5.8-19.5%, respectively. Method detection limits of plasma and breast milk ranged from 0.18-1.36 and 0.09-2.66ngmL(-1), respectively. We analyzed 63 plasma and 30 breastmilk samples collected from farmworkers in Chiang Mai Province to determine the suitability of this method for occupational exposure assessment. Of the 11 pesticides measured, seven were detected in plasma samples and five were detected in breast milk samples. Mass spectrometry was used to confirm results. Overall, this method is rapid and reliable. It offers the laboratories with limited access to mass spectrometry a capacity to investigate levels OP pesticides in plasma and breastmilk in those

  6. Behavior of organophosphates and hydrophilic ethers during bank filtration and their potential application as organic tracers. A field study from the Oderbruch, Germany.

    PubMed

    Stepien, D K; Regnery, J; Merz, C; Püttmann, W

    2013-08-01

    The behavior of organophosphates and ethers during riverbank filtration and groundwater flow was assessed to determine their suitability as organic tracers. Four sampling campaigns were conducted at the Oderbruch polder, Germany to establish the presence of chlorinated flame retardants (TCEP, TCPP, TDCP), non-chlorinated plasticizers (TBEP, TiBP, TnBP), and hydrophilic ethers (1,4-dioxane, monoglyme, diglyme, triglyme, tetraglyme) in the Oder River, main drainage ditch, and anoxic aquifer. Selected parameters were measured in order to determine the hydro-chemical composition of both, river water and groundwater. The results of the study confirm that organophosphates (OPs) are more readily attenuated during bank filtration compared to ethers. Both in the river and the groundwater, TCPP was the most abundant OP with concentrations in the main drainage ditch ranging between 105 and 958 ng L(-1). 1,4-dioxane, triglyme, and tetraglyme demonstrated persistent behavior during bank filtration and in the anoxic groundwater. In the drainage ditch concentrations of 1,4-dioxane, triglyme, and tetraglyme ranged between 1090 and 1467 ng L(-1), 37 and 149 ng L(-1), and 496 and 1403 ng L(-1), respectively. A positive correlation was found for the inorganic tracer chloride with 1,4-dioxane and tetraglyme. These results confirm the possible application of these ethers as environmental organic tracers. Both inorganic and organic compounds showed temporal variability in the surface- and groundwater. Discharge of the river water, concentrations of analytes at the time of infiltration and attenuation were identified as factors influencing the variable amounts of the analytes in the surface and groundwater. These findings are also of great importance for the production of drinking water via bank filtration and natural and artificial groundwater recharge as the physicochemical properties of ethers create challenges in their removal.

  7. Organophosphate acetylcholine esterase inhibitor poisoning from a home-made shampoo.

    PubMed

    Sadaka, Yair; Broides, Arnon; Tzion, Raffi Lev; Lifshitz, Matitiahu

    2011-07-01

    Organophosphate acetylcholine esterase inhibitor poisoning is a major health problem in children. We report an unusual cause of organophosphate acetylcholine esterase inhibitor poisoning. Two children were admitted to the pediatric intensive care unit due to organophosphate acetylcholine esterase inhibitor poisoning after exposure from a home-made shampoo that was used for the treatment of head lice. Owing to no obvious source of poisoning, the diagnosis of organophosphate acetylcholine esterase inhibitor poisoning in one of these patients was delayed. Both patients had an uneventful recovery. Organophosphate acetylcholine esterase inhibitor poisoning from home-made shampoo is possible. In cases where the mode of poisoning is unclear, direct questioning about the use of home-made shampoo is warranted, in these cases the skin and particularly the scalp should be rinsed thoroughly as soon as possible.

  8. Organophosphate acetylcholine esterase inhibitor poisoning from a home-made shampoo

    PubMed Central

    Sadaka, Yair; Broides, Arnon; Tzion, Raffi Lev; Lifshitz, Matitiahu

    2011-01-01

    Organophosphate acetylcholine esterase inhibitor poisoning is a major health problem in children. We report an unusual cause of organophosphate acetylcholine esterase inhibitor poisoning. Two children were admitted to the pediatric intensive care unit due to organophosphate acetylcholine esterase inhibitor poisoning after exposure from a home-made shampoo that was used for the treatment of head lice. Owing to no obvious source of poisoning, the diagnosis of organophosphate acetylcholine esterase inhibitor poisoning in one of these patients was delayed. Both patients had an uneventful recovery. Organophosphate acetylcholine esterase inhibitor poisoning from home-made shampoo is possible. In cases where the mode of poisoning is unclear, direct questioning about the use of home-made shampoo is warranted, in these cases the skin and particularly the scalp should be rinsed thoroughly as soon as possible. PMID:21887044

  9. Quantitative structure-activity relationships for organophosphates binding to acetylcholinesterase.

    PubMed

    Ruark, Christopher D; Hack, C Eric; Robinson, Peter J; Anderson, Paul E; Gearhart, Jeffery M

    2013-02-01

    Organophosphates are a group of pesticides and chemical warfare nerve agents that inhibit acetylcholinesterase, the enzyme responsible for hydrolysis of the excitatory neurotransmitter acetylcholine. Numerous structural variants exist for this chemical class, and data regarding their toxicity can be difficult to obtain in a timely fashion. At the same time, their use as pesticides and military weapons is widespread, which presents a major concern and challenge in evaluating human toxicity. To address this concern, a quantitative structure-activity relationship (QSAR) was developed to predict pentavalent organophosphate oxon human acetylcholinesterase bimolecular rate constants. A database of 278 three-dimensional structures and their bimolecular rates was developed from 15 peer-reviewed publications. A database of simplified molecular input line entry notations and their respective acetylcholinesterase bimolecular rate constants are listed in Supplementary Material, Table I. The database was quite diverse, spanning 7 log units of activity. In order to describe their structure, 675 molecular descriptors were calculated using AMPAC 8.0 and CODESSA 2.7.10. Orthogonal projection to latent structures regression, bootstrap leave-random-many-out cross-validation and y-randomization were used to develop an externally validated consensus QSAR model. The domain of applicability was assessed by the William's plot. Six external compounds were outside the warning leverage indicating potential model extrapolation. A number of compounds had residuals >2 or <-2, indicating potential outliers or activity cliffs. The results show that the HOMO-LUMO energy gap contributed most significantly to the binding affinity. A mean training R (2) of 0.80, a mean test set R (2) of 0.76 and a consensus external test set R (2) of 0.66 were achieved using the QSAR. The training and external test set RMSE values were found to be 0.76 and 0.88. The results suggest that this QSAR model can be used in

  10. Application of ultraperformance liquid chromatography/mass spectrometry-based metabonomic techniques to analyze the joint toxic action of long-term low-level exposure to a mixture of organophosphate pesticides on rat urine profile.

    PubMed

    Du, Longfei; Wang, Hong; Xu, Wei; Zeng, Yan; Hou, Yurong; Zhang, Yuqiu; Zhao, Xiujuan; Sun, Changhao

    2013-07-01

    In previously published articles, we evaluated the toxicity of four organophosphate (OP) pesticides (dichlorvos, dimethoate, acephate, and phorate) to rats using metabonomic technology at their corresponding no observed adverse effect level (NOAEL). Results show that a single pesticide elicits no toxic response. This study aimed to determine whether chronic exposure to a mixture of the above four pesticides (at their corresponding NOAEL) can lead to joint toxic action in rats using the same technology. Pesticides were administered daily to rats through drinking water for 24 weeks. The above mixture of the four pesticides showed joint toxic action at the NOAEL of each pesticide. The metabonomic profiles of rats urine were analyzed by ultraperformance liquid chromatography/mass spectrometry. The 16 metabolites statistically significantly changed in all treated groups compared with the control group. Dimethylphosphate and dimethyldithiophosphate exclusively detected in all treated groups can be used as early, sensitive biomarkers for exposure to a mixture of the OP pesticides. Moreover, exposure to the OP pesticides resulted in increased 7-methylguanine, ribothymidine, cholic acid, 4-pyridoxic acid, kynurenine, and indoxyl sulfate levels, as well as decreased hippuric acid, creatinine, uric acid, gentisic acid, C18-dihydrosphingosine, phytosphingosine, suberic acid, and citric acid. The results indicated that a mixture of OP pesticides induced DNA damage and oxidative stress, disturbed the metabolism of lipids, and interfered with the tricarboxylic acid cycle. Ensuring food safety requires not only the toxicology test data of each pesticide for the calculation of the acceptable daily intake but also the joint toxic action.

  11. Aquatic life water quality criteria derived via the UC Davis method: I. Organophosphate insecticides.

    PubMed

    Palumbo, Amanda J; Tenbrook, Patti L; Fojut, Tessa L; Faria, Isabel R; Tjeerdema, Ronald S

    2012-01-01

    A new methodology for deriving freshwater aquatic life water quality criteria,developed by the University of California Davis, was used to derive criteria for three organophosphate insecticides. The UC Davis methodology resulted in similar criteria to other accepted methods, and incorporated new approaches that enable criteria generation in cases where the existing USEPA guidance cannot be used.Acute and chronic water quality criteria were derived for chlorpyrifos (10 and 10 ng/L, respectively), diazinon (200 and 70 ng/L, respectively), and malathion(170 and 28 ng/L, respectively). For acute criteria derivation, Burr Type III SSDs were fitted to the chlorpyrifos and diazinon acute toxicity data sets while an alternative assessment factor procedure was used for malathion because that acute data set did not contain adequate species diversity to use a distribution.ACRs were used to calculate chronic criteria because there was a dearth of chronic data in all cases, especially for malathion, for which there was a lack of paired acute and chronic invertebrate data. Another alternate procedure enabled calculation of the malathion chronic criterion by combining a default ratio with the experimentally derived ratios. A review of the diazinon chronic criterion found it to be under protective of cladoceran species, so a more protective criterion was calculated using a lower distributional estimate. The acute and chronic data sets were assembled using a transparent and consistent system for judging the relevance and reliability of studies, and the individual study review notes are included.The resulting criteria are unique in that they were reviewed to ensure particular protection of sensitive and threatened and endangered species, and mixture toxicity is incorporated into criteria compliance for all three compounds.For chlorpyrifos and diazinon, the UCDM generated criteria similar to the long-standing USEPA (1985) method, with less taxa requirements, a more statistically

  12. Thermal desorption-gas chromatography-mass spectrometry method to determine phthalate and organophosphate esters from air samples.

    PubMed

    Aragón, M; Borrull, F; Marcé, R M

    2013-08-16

    A method based on thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) has been developed to determine four organophosphate esters, seven phthalate esters, and bis(2-ethylhexyl) adipate in the gas phase from harbour and urban air samples. The method involves the sampling of 1.5L of air in a Tenax TA sorbent tube followed by thermal desorption (using a Tenax TA cryogenic trap) coupled to gas chromatography-mass spectrometry. The repeatability of the method expressed as %RSD (n=3) is less than 15% and the MQLs are between 0.007μgm(-3) (DMP, TBP, BBP, TPP and DnOP) and 6.7μgm(-3) (DEHP). The method was successfully applied in two areas (urban and harbour) testing two and three points in each one, respectively. Some of these compounds were found in both urban and harbour samples. Di-(2-ethylhexyl)phthalate was the most abundant compound found in both areas at concentration levels between 6.7μgm(-3) and 136.4μgm(-3). This study demonstrates that thermal desorption is an efficient method for the determination of these semi-volatile compounds in the gas phase fraction of air samples.

  13. Environmentally relevant organophosphate triesters in herring gulls: In vitro biotransformation and kinetics and diester metabolite formation using a hepatic microsomal assay.

    PubMed

    Greaves, Alana K; Su, Guanyong; Letcher, Robert J

    2016-10-01

    The in vitro biotransformation and kinetics of six organophosphate triester (OPE) flame retardants were investigated in herring gulls (Larus argentatus) from the Great Lakes using a hepatic microsomal metabolism assay. Administration of each individual OPE (tri-n-butyl phosphate (TNBP), tris(2-butoxyethyl) phosphate (TBOEP), triphenyl phosphate (TPHP), triethyl phosphate (TEP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris(2-chloroisopropyl) phosphate (TCIPP)) to the in vitro assay (concentration range 0.01 to 10μM) resulted in rapid depletion with the exception of TEP. Following the Michaelis-Menten enzyme kinetics model, a preliminary 2-minute incubation period was used to estimate the Vmax (±SE) values (i.e., the maximal rate of reaction for a saturated enzyme system), which ranged from 5.0±0.4 (TPHP) to 29±18pmol/min/mg protein (TBOEP), as well as the KM (±SE) values (i.e., the OPE concentration corresponding to one half of the Vmax), which ranged from 9.8±1 (TPHP) to 189±135nM (TBOEP). Biotransformation assays over a 100-minute incubation period revealed that TNBP was metabolized most rapidly (with a depletion rate of 73±4pmol/min/mg protein), followed by TBOEP (53±8pmol/min/mg), TCIPP (27±1pmol/min/mg), TPHP (22±2pmol/min/mg) and TDCIPP (8±1pmol/min/mg). In vitro biotransformation of OP triesters was clearly structure-dependent where non-halogenated alkyl OP triesters were metabolized more rapidly than halogenated alkyl triesters. Halogenated OP triesters were transformed to their respective diesters more efficiently relative to non-halogenated OP triesters. To our knowledge, this is the first study to investigate OP triester metabolism and OP diester formation in an avian or wildlife model system, which is important to understand the fate and biological activity of OPEs in an exposed organism.

  14. Monte Carlo QSAR models for predicting organophosphate inhibition of acetycholinesterase.

    PubMed

    Veselinović, J B; Nikolić, G M; Trutić, N V; Živković, J V; Veselinović, A M

    2015-06-01

    A series of 278 organophosphate compounds acting as acetylcholinesterase inhibitors has been studied. The Monte Carlo method was used as a tool for building up one-variable quantitative structure-activity relationship (QSAR) models for acetylcholinesterase inhibition activity based on the principle that the target endpoint is treated as a random event. As an activity, bimolecular rate constants were used. The QSAR models were based on optimal descriptors obtained from Simplified Molecular Input-Line Entry System (SMILES) used for the representation of molecular structure. Two modelling approaches were examined: (1) 'classic' training-test system where the QSAR model was built with one random split into a training, test and validation set; and (2) the correlation balance based QSAR models were built with two random splits into a sub-training, calibration, test and validation set. The DModX method was used for defining the applicability domain. The obtained results suggest that studied activity can be determined with the application of QSAR models calculated with the Monte Carlo method since the statistical quality of all build models was very good. Finally, structural indicators for the increase and the decrease of the bimolecular rate constant are defined. The possibility of using these results for the computer-aided design of new organophosphate compounds is presented.

  15. Organophosphate and carbamate poisoning in infants and children.

    PubMed

    Zwiener, R J; Ginsburg, C M

    1988-01-01

    The clinical and laboratory features of moderate to severe organophosphate and carbamate toxicity in 37 infants and children are presented. Ingestion of an improperly stored liquid pesticide was the most common route of intoxication (76% of patients); five (14%) children became intoxicated after playing on carpets and floors of homes that had been sprayed or fogged by unlicensed exterminators. The transfer diagnoses were incorrect for 16 or 20 patients who were transferred to our center from another institution. Miosis (73%), excessive salivation (70%), muscle weakness (68%), and lethargy (54%) were the most common abnormal signs; 49% and 22% of patients had tachycardia and seizures, respectively, and 38% of children had respiratory insufficiency that required endotracheal intubation and mechanical ventilation. The results of erythrocyte and serum cholinesterase activity assays were concordant in 83% of patients. Thirty-four (92%) patients were treated with atropine and/or pralidoxime; three patients required only supportive care. Most patients had a prompt response to therapy; however, two patients with organophosphate toxicity required multiple doses of atropine during a 24-hour period; in both instances, the doses of atropine were subtherapeutic. There were no deaths. Pneumonitis and/or atelectasis developed in ten patients, including six who had ingested a petroleum distillate-containing insecticide.

  16. Globalizing Engineers through International Co-op.

    ERIC Educational Resources Information Center

    Nolan, Riall W.; Elliott, Gayle G.

    2000-01-01

    Describes the International Co-Op Program at the University of Cincinnati (Ohio) which provides students with work opportunities in Germany, Japan, and Latin America. Emphasis is on the program structure and philosophy as it applies to engineering students. Lessons learned concern the need to work with all stakeholders and constant program…

  17. A Complex Interaction Between Reduced Reelin Expression and Prenatal Organophosphate Exposure Alters Neuronal Cell Morphology

    PubMed Central

    Mullen, Brian R.; Ross, Brennan; Chou, Joan Wang; Khankan, Rana; Khialeeva, Elvira; Bui, Kimberly

    2016-01-01

    Genetic and environmental factors are both likely to contribute to neurodevelopmental disorders including schizophrenia, autism spectrum disorders, and major depressive disorders. Prior studies from our laboratory and others have demonstrated that the combinatorial effect of two factors—reduced expression of reelin protein and prenatal exposure to the organophosphate pesticide chlorpyrifos oxon—gives rise to acute biochemical effects and to morphological and behavioral phenotypes in adolescent and young adult mice. In the current study, we examine the consequences of these factors on reelin protein expression and neuronal cell morphology in adult mice. While the cell populations that express reelin in the adult brain appear unchanged in location and distribution, the levels of full length and cleaved reelin protein show persistent reductions following prenatal exposure to chlorpyrifos oxon. Cell positioning and organization in the hippocampus and cerebellum are largely normal in animals with either reduced reelin expression or prenatal exposure to chlorpyrifos oxon, but cellular complexity and dendritic spine organization is altered, with a skewed distribution of immature dendritic spines in adult animals. Paradoxically, combinatorial exposure to both factors appears to generate a rescue of the dendritic spine phenotypes, similar to the mitigation of behavioral and morphological changes observed in our prior study. Together, our observations support an interaction between reelin expression and chlorpyrifos oxon exposure that is not simply additive, suggesting a complex interplay between genetic and environmental factors in regulating brain morphology. PMID:27364165

  18. Effect of stress at dosing on organophosphate and heavy metal toxicity

    SciTech Connect

    Jortner, Bernard S.

    2008-11-15

    This paper reviews recent studies assessing the effect of well-defined, severe, transient stress at dosing on two classical models of toxicity. These are the acute (anticholinesterase) toxicity seen following exposure to the organophosphate insecticide chlorpyrifos, and the nephrotoxicity elicited by the heavy metal depleted uranium, in rats. Stress was induced by periods of restraint and forced swimming in days to weeks preceding toxicant exposure. Forced swimming was far more stressful, as measured by marked, if transient, elevation of plasma corticosterone. This form of stress was administered immediately prior to administration of chlorpyrifos or depleted uranium. Chlorpyrifos (single 60 mg/kg subcutaneously) elicited marked inhibition of brain acetylcholinesterase 4-day post-dosing. Depleted uranium (single intramuscular doses of 0.1, 0.3 or 1.0 mg/kg uranium) elicited dose-dependent increase in kidney concentration of the metal, with associated injury to proximal tubular epithelium and increases in serum blood urea nitrogen and creatinine during the 30-day post-dosing period. Stress at dosing had no effect on these toxicologic endpoints.

  19. Ultrastructure of the ankylotic area in the osteopetrotic op/op mouse.

    PubMed

    Okada, H; Sato, Y; Sakae, T; Yamamoto, H

    1996-07-01

    The op/op mouse, which carries an osteopetrotic mutation, suffers from complete failure of tooth eruption. Commonly the teeth are ankylosed to the bone. Previous reports of ankylosis in the op/op mouse have been based on light microscopy. The aim of this study was to clarify the ultrastructural features of the ankylotic area using the oolong tea extract (OTE) staining technique. The ultrastructural features of ankylosis did not parallel the findings of light microscopy. OTE staining clearly stained the collagen fibers of bone and tooth, and the space dividing the tooth and bone was revealed by transmission electron microscopy. In comparison, light microscopy failed to reveal this space and the ankylosis was unclear. The true ankylotic area was smooth and the tooth was tightly ankylosed to the bone. PMID:8854598

  20. EQCM Immunoassay for Phosphorylated Acetylcholinesterase as a Biomarker for Organophosphate Exposures Based on Selective Zirconia Adsorption and Enzyme-Catalytic Precipitation

    SciTech Connect

    Wang, Hua; Wang, Jun; Choi, Daiwon; Tang, Zhiwen; Wu, Hong; Lin, Yuehe

    2009-03-01

    A zirconia (ZrO2) adsorption-based immunoassay by electrochemical quartz crystal microbalance (EQCM) has been initially developed, aiming at the detection of phosphorylated acetylcholinesterase (AChE) as a potential biomarker for bio-monitoring exposures to organophosphate (OP) pesticides and chemical warfare agents. Hydroxyl-derivatized monolayer was preferably chosen to modify the crystal serving as the template for directing the electro-deposition of ZrO2 film with uniform nanostructures. The resulting ZrO2 film was utilized to selectively capture phosphorylated AChE from the sample media. Horseradish peroxidase (HRP)-labeled anti-AChE antibodies were further employed to recognize the captured phosphorylated protein. Enzyme-catalytic oxidation of the benzidine substrate resulted in the accumulation of insoluble product on the functionalized crystal. Ultrasensitive EQCM quantification by mass-amplified frequency responses as well as rapid qualification by visual color changes of product could be thus achieved. Moreover, 4-chloro-1-naphthol (CN) was comparably studied as an ideal chromogenic substrate for the enzyme-catalytic precipitation. Experimental results show that the developed EQCM technique can allow for the detection of phosphorylated AChE in human plasma. Such an EQCM immunosensing format opens a new door towards the development of simple, sensitive, and field-applicable biosensor for biologically monitoring low-level OP exposures.

  1. Evaluation of exposure to organophosphate, carbamate, phenoxy acid, and chlorophenol pesticides in pregnant women from 10 Caribbean countries.

    PubMed

    Forde, Martin S; Robertson, Lyndon; Laouan Sidi, Elhadji A; Côté, Suzanne; Gaudreau, Eric; Drescher, Olivia; Ayotte, Pierre

    2015-09-01

    Pesticides are commonly used in tropical regions such as the Caribbean for both household and agricultural purposes. Of particular concern is exposure during pregnancy, as these compounds can cross the placental barrier and interfere with fetal development. The objective of this study was to evaluate exposure of pregnant women residing in 10 Caribbean countries to the following commonly used classes of pesticides in the Caribbean: organophosphates (OPs), carbamates, phenoxy acids, and chlorophenols. Out of 438 urine samples collected, 15 samples were randomly selected from each Caribbean country giving a total of 150 samples. Samples were analyzed for the following metabolites: six OP dialkylphosphate metabolites [dimethylphosphate (DMP), dimethylthiophosphate (DMTP), dimethyldithiophosphate (DMDTP), diethylphosphate (DEP), diethylthiophosphate (DETP) and diethyldithiophosphate (DEDTP)]; two carbamate metabolites [2-isopropoxyphenol (2-IPP) and carbofuranphenol]; one phenoxy acid 2,4-dichlorophenoxyacetic acid (2,4-D); and five chlorophenols [2,4-dichlorophenol (DCP), 2,5-dichlorophenol (2,5-DCP), 2,4,5-trichlorophenol (TCP), 2,4,6-trichlorophenol (2,4,6-TCP), and pentachlorophenol (PCP)]. OP metabolites were consistently detected in ≥60% of the samples from Antigua and Barbuda, Bermuda, and Jamaica. Of the carbamate metabolites, 2-IPP was detected in seven of the 10 Caribbean countries with a detection frequency around 30%, whereas carbofuranphenol was detected in only one sample. The detection frequency for the phenoxy acid 2,4-D ranged from 20% in Grenada to a maximum of 67% in Belize. Evidence of exposure to chlorophenol pesticides was also established with 2,4-DCP by geometric means ranging from 0.52 μg L(-1) in St Lucia to a maximum of 1.68 μg L(-1) in Bermuda. Several extreme concentrations of 2,5-DCP were detected in four Caribbean countries-Belize (1100 μg L(-1)), Bermuda (870 μg L(-1)), Jamaica (1300 μg L(-1)), and St Kitts and Nevis (1400 μg L(-1

  2. An unusual case of homicide by use of repeated administration of organophosphate insecticides.

    PubMed

    De Letter, E A; Cordonnier, J A C M; Piette, M H A

    2002-03-01

    We present an unusual murder case by use of repeated administration of organophosphate insecticides. A 49-year-old woman suffering from mental retardation, epileptic fits and acromegaly was poisoned by her husband. At first, her death was considered as a 'sudden and unexpected' natural death. Abdominal abscesses of pancreatic origin found at autopsy were compatible with repeated administration of pesticides with anticholinergic action. In her medical history at least one episode consistent with an organophosphate intoxication was retrieved. Thorough inquiry revealed that the victim had ingested phosphamidon and/or omethoate orally. Organophosphate intoxication should be considered when unexplained neurological symptoms are associated with pancreatic disturbances.

  3. Pilot study on the combination of an organophosphate-based insecticide paint and pyrethroid-treated long lasting nets against pyrethroid resistant malaria vectors in Burkina Faso.

    PubMed

    Mosqueira, Beatriz; Soma, Dieudonné D; Namountougou, Moussa; Poda, Serge; Diabaté, Abdoulaye; Ali, Ouari; Fournet, Florence; Baldet, Thierry; Carnevale, Pierre; Dabiré, Roch K; Mas-Coma, Santiago

    2015-08-01

    A pilot study to test the efficacy of combining an organophosphate-based insecticide paint and pyrethroid-treated Long Lasting Insecticide Treated Nets (LLINs) against pyrethroid-resistant malaria vector mosquitoes was performed in a real village setting in Burkina Faso. Paint Inesfly 5A IGR™, comprised of two organophosphates (OPs) and an Insect Growth Regulator (IGR), was tested in combination with pyrethroid-treated LLINs. Efficacy was assessed in terms of mortality for 12 months using Early Morning Collections of malaria vectors and 30-minute WHO bioassays. Resistance to pyrethroids and OPs was assessed by detecting the frequency of L1014F and L1014S kdr mutations and Ace-1(R)G119S mutation, respectively. Blood meal origin was identified using a direct enzyme-linked immunosorbent assay (ELISA). The combination of Inesfly 5A IGR™ and LLINs was effective in killing 99.9-100% of malaria vector populations for 6 months regardless of the dose and volume treated. After 12 months, mortality rates decreased to 69.5-82.2%. The highest mortality rates observed in houses treated with 2 layers of insecticide paint and a larger volume. WHO bioassays supported these results: mortalities were 98.8-100% for 6 months and decreased after 12 months to 81.7-97.0%. Mortality rates in control houses with LLINs were low. Collected malaria vectors consisted exclusively of Anopheles coluzzii and were resistant to pyrethroids, with a L1014 kdr mutation frequency ranging from 60 to 98% through the study. About 58% of An. coluzzii collected inside houses had bloodfed on non-human animals. Combining Inesfly 5A IGR™ and LLINs yielded a one year killing efficacy against An. coluzzii highly resistant to pyrethroids but susceptible to OPs that exhibited an anthropo-zoophilic behaviour in the study area. The results obtained in a real setting supported previous work performed in experimental huts and underscore the need to study the impact that this novel strategy may have on clinical

  4. Pilot study on the combination of an organophosphate-based insecticide paint and pyrethroid-treated long lasting nets against pyrethroid resistant malaria vectors in Burkina Faso.

    PubMed

    Mosqueira, Beatriz; Soma, Dieudonné D; Namountougou, Moussa; Poda, Serge; Diabaté, Abdoulaye; Ali, Ouari; Fournet, Florence; Baldet, Thierry; Carnevale, Pierre; Dabiré, Roch K; Mas-Coma, Santiago

    2015-08-01

    A pilot study to test the efficacy of combining an organophosphate-based insecticide paint and pyrethroid-treated Long Lasting Insecticide Treated Nets (LLINs) against pyrethroid-resistant malaria vector mosquitoes was performed in a real village setting in Burkina Faso. Paint Inesfly 5A IGR™, comprised of two organophosphates (OPs) and an Insect Growth Regulator (IGR), was tested in combination with pyrethroid-treated LLINs. Efficacy was assessed in terms of mortality for 12 months using Early Morning Collections of malaria vectors and 30-minute WHO bioassays. Resistance to pyrethroids and OPs was assessed by detecting the frequency of L1014F and L1014S kdr mutations and Ace-1(R)G119S mutation, respectively. Blood meal origin was identified using a direct enzyme-linked immunosorbent assay (ELISA). The combination of Inesfly 5A IGR™ and LLINs was effective in killing 99.9-100% of malaria vector populations for 6 months regardless of the dose and volume treated. After 12 months, mortality rates decreased to 69.5-82.2%. The highest mortality rates observed in houses treated with 2 layers of insecticide paint and a larger volume. WHO bioassays supported these results: mortalities were 98.8-100% for 6 months and decreased after 12 months to 81.7-97.0%. Mortality rates in control houses with LLINs were low. Collected malaria vectors consisted exclusively of Anopheles coluzzii and were resistant to pyrethroids, with a L1014 kdr mutation frequency ranging from 60 to 98% through the study. About 58% of An. coluzzii collected inside houses had bloodfed on non-human animals. Combining Inesfly 5A IGR™ and LLINs yielded a one year killing efficacy against An. coluzzii highly resistant to pyrethroids but susceptible to OPs that exhibited an anthropo-zoophilic behaviour in the study area. The results obtained in a real setting supported previous work performed in experimental huts and underscore the need to study the impact that this novel strategy may have on clinical

  5. How to Form a Food Co-op.

    ERIC Educational Resources Information Center

    Dodge, Philip; And Others

    Based on questions asked during an adult education course at Truman College (Chicago), this booklet was designed to be a simple organizing manual for small neighborhood preorder food cooperatives (co-ops). The guide covers basic information for organizing a co-op, definition of a co-op, what jobs are needed, getting the food, wholesale sources,…

  6. Organophosphate insecticide poisoning of Canada geese in the Texas panhandle

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Wynn, L.D.; Flickinger, Edward L.; Kolbe, E.J.

    1982-01-01

    Sixteen hundred waterfowl, mostly Canada Geese, died near Etter, Texas, in late January 1981 from anticholinesterase poisoning. Winter wheat in the area of the die-off had been treated with organophosphate insecticides to control greenbugs. Cholinesterase (ChE) levels in brains of a sample of geese found dead were 75% below normal, enough to account for death (Ludke et al. 1975). The gastrointestinal (G I) tracts of geese found dead were packed with winter wheat; gas chromatography techniques identified parathion and methyl parathion in the GI tract contents. Residues of both chemicals were confirmed by mass spectrometry. We recommend that less toxic materials, such as malathion, be used on grain crops when waterfowl are in the vicinity of treatment.

  7. Joint SatOPS Compatibility Efforts

    NASA Technical Reports Server (NTRS)

    Smith, Danford

    2010-01-01

    This slide presentation reviews NASA Goddard Space Flight Center's (GSFC) participation in the interagency cooperation committee, the Joint SatOps Compatibility Committee (JSCC), and the compatible Sat 2 efforts. Part of GSFC's participation in the JSCC is to work with the Goddard Mission Systems Evolution Center (GMSEC) to provides a publish/subscribe framework to enable rapid integration of commercially available satellite control products.

  8. Genetic polymorphisms of GSTM1, GSTT1 and GSTP1 and susceptibility to DNA damage in workers occupationally exposed to organophosphate pesticides.

    PubMed

    Singh, Satyender; Kumar, Vivek; Singh, Priyanka; Thakur, Sachin; Banerjee, Basu Dev; Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen; Jain, Sudhir Kumar; Rai, Arvind

    2011-10-01

    GSTM1, T1 and P1 are important enzymes of glutathione S-transferases (GSTs), involved in the metabolism of many endogenous and exogenous compounds. Individual genetic variation in these metabolizing enzymes may influence the metabolism of their substrates. The present study was designed to determine the genotoxic effects using DNA damage and its association with GSTM1, GSTT1, and GSTP1 (Ile105Val) genetic polymorphisms in workers occupationally exposed to organophosphate pesticides (OPs). We examined 230 subjects including 115 workers occupationally exposed to OPs and an equal number of normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using individual PCR or PCR-RFLP. Significantly higher DNA tail moment (TM) was observed in workers as compared to control subjects (14.41 ± 2.25 vs. 6.36 ± 1.41 tail % DNA, p<0.001). The results revealed significantly higher DNA TM in workers with GSTM1 null genotype than those with GSTM1 positive (15.18 vs. 14.15 tail % DNA, p=0.03). A significantly higher DNA TM was also observed in workers with homozygous Ile-Ile GSTP1 genotype than heterozygous (Ile-Val) and mutant (Val-Val) GSTP1 genotype (p=0.02). In conclusion, the results show that null deletion of GSTM1 and homozygote wild GSTP1 genotype could be related to inter-individual differences in DNA damage arises from the gene-environment interactions in workers occupationally exposed to OPs.

  9. Development of a Computer-Based Survey Instrument for Organophosphate and N-Methyl-Carbamate Exposure Assessment among Agricultural Pesticide Handlers

    PubMed Central

    Hofmann, Jonathan N.; Checkoway, Harvey; Borges, Ofelio; Servin, Flor; Fenske, Richard A.; Keifer, Matthew C.

    2010-01-01

    Background: Assessment of occupational pesticide exposures based on self-reported information can be challenging, particularly with immigrant farm worker populations for whom specialized methods are needed to address language and cultural barriers and account for limited literacy. An audio computer-assisted self-interview (A-CASI) survey instrument was developed to collect information about organophosphate (OP) and N-methyl-carbamate (CB) exposures and other personal characteristics among male agricultural pesticide handlers for an ongoing cholinesterase biomonitoring study in Washington State. Objectives: To assess the feasibility of collecting data using the A-CASI instrument and evaluate reliability for a subset of survey items. Methods: The survey consisted of 64 items administered in Spanish or English on a touch-screen tablet computer. Participants listened to digitally recorded questions on headphones and selected responses on the screen, most of which were displayed as images or icons to facilitate participation of low literacy respondents. From 2006–2008, a total of 195 participants completed the survey during the OP/CB application seasons on at least one occasion. Percent agreement and kappa coefficients were calculated to evaluate test–retest reliability for selected characteristics among 45 participants who completed the survey on two separate occasions within the same year. Results: Almost all participants self-identified as Hispanic or Latino (98%), and 97% completed the survey in Spanish. Most participants completed the survey in a half-hour or less, with minimal assistance from on-site research staff. Analyses of test–retest reliability showed substantial agreement for most demographic, work history, and health characteristics and at least moderate agreement for most variables related to personal protective equipment use during pesticide applications. Conclusions: This A-CASI survey instrument is a novel method that has been used successfully

  10. Lipid peroxidation and oxidative stress responses in juvenile salmon exposed to waterborne levels of the organophosphate compounds tris(2-butoxyethyl)- and tris(2-chloroethyl) phosphates.

    PubMed

    Arukwe, Augustine; Carteny, Camilla Catarci; Eggen, Trine

    2016-01-01

    There is limited knowledge on the toxicological, physiological, and molecular effects attributed to organophosphate (OP) compounds currently used as flame retardants or additives in consumer products. This study investigated the effects on oxidative stress and lipid peroxidation in juvenile Atlantic salmon liver and brain samples after exposure to two OP compounds, tris(2-butoxyethyl) phosphate (TBOEP) and tris(2-chloroethyl) phosphate (TCEP). In this study, groups of juvenile Atlantic salmon were exposed using a semistatic experimental protocol over a 7-d period to 3 different concentrations (0.04, 0.2, or 1 mg/L) of TBOEP and TCEP. When toxicological factors such as bioaccumulation and bioconcentration, and chemical structural characteristics and behavior, including absorption to solid materials, are considered, these concentrations represent environmentally relevant concentrations. The concentrations of the contaminants were derived from levels of their environmental occurrence. The expression of genes related to oxidative stress-glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST)-and to lipid peroxidation-peroxisome proliferator-activated receptors (PPAR)-were determined using quantitative (real-time) polymerase chain reaction (PCR). The presence of PPAR proteins was also investigated using immunochemical methods. Levels of thiobarbituric acid-reactive substances (TBARS) in liver were used as a measure of lipid peroxidation. Overall, our data show an increase in lipid peroxidation, and this was associated with an augmented expression of genes from the glutathione family of responses. Interestingly, PPAR expression in liver after exposure to TBOEP and TCEP was consistently decreased compared to controls, while expression in brain did not show a similar trend. The results suggest that OP contaminants may induce oxidative stress and thus production of reactive oxygen substances (ROS), and modulate lipid peroxidation processes

  11. Comparative toxicities of organophosphate and pyrethroid insecticides to aquatic macroarthropods.

    PubMed

    Halstead, Neal T; Civitello, David J; Rohr, Jason R

    2015-09-01

    As agricultural expansion and intensification increase to meet the growing global food demand, so too will insecticide use and thus the risk of non-target effects. Insecticide pollution poses a particular threat to aquatic macroarthropods, which play important functional roles in freshwater ecosystems. Thus, understanding the relative toxicities of insecticides to non-target functional groups is critical for predicting effects on ecosystem functions. We exposed two common macroarthropod predators, the crayfish Procambarus alleni and the water bug Belostoma flumineum, to three insecticides in each of two insecticide classes (three organophosphates: chlorpyrifos, malathion, and terbufos; and three pyrethroids: esfenvalerate, λ-cyhalothrin, and permethrin) to assess their toxicities. We generated 150 simulated environmental exposures using the US EPA Surface Water Contamination Calculator to determine the proportion of estimated peak environmental concentrations (EECs) that exceeded the US EPA level of concern (0.5×LC50) for non-endangered aquatic invertebrates. Organophosphate insecticides generated consistently low-risk exposure scenarios (EECs<0.5×LC50) for both P. alleni and B. flumineum. Pyrethroid exposure scenarios presented consistently high risk (EECs>0.5×LC50) to P. alleni, but not to B. flumineum, where only λ-cyhalothrin produced consistently high-risk exposures. Survival analyses demonstrated that insecticide class accounted for 55.7% and 91.1% of explained variance in P. alleni and B. flumineum survival, respectively. Thus, risk to non-target organisms is well predicted by pesticide class. Identifying insecticides that pose low risk to aquatic macroarthropods might help meet increased demands for food while mitigating against potential negative effects on ecosystem functions.

  12. Comparative toxicities of organophosphate and pyrethroid insecticides to aquatic macroarthropods.

    PubMed

    Halstead, Neal T; Civitello, David J; Rohr, Jason R

    2015-09-01

    As agricultural expansion and intensification increase to meet the growing global food demand, so too will insecticide use and thus the risk of non-target effects. Insecticide pollution poses a particular threat to aquatic macroarthropods, which play important functional roles in freshwater ecosystems. Thus, understanding the relative toxicities of insecticides to non-target functional groups is critical for predicting effects on ecosystem functions. We exposed two common macroarthropod predators, the crayfish Procambarus alleni and the water bug Belostoma flumineum, to three insecticides in each of two insecticide classes (three organophosphates: chlorpyrifos, malathion, and terbufos; and three pyrethroids: esfenvalerate, λ-cyhalothrin, and permethrin) to assess their toxicities. We generated 150 simulated environmental exposures using the US EPA Surface Water Contamination Calculator to determine the proportion of estimated peak environmental concentrations (EECs) that exceeded the US EPA level of concern (0.5×LC50) for non-endangered aquatic invertebrates. Organophosphate insecticides generated consistently low-risk exposure scenarios (EECs<0.5×LC50) for both P. alleni and B. flumineum. Pyrethroid exposure scenarios presented consistently high risk (EECs>0.5×LC50) to P. alleni, but not to B. flumineum, where only λ-cyhalothrin produced consistently high-risk exposures. Survival analyses demonstrated that insecticide class accounted for 55.7% and 91.1% of explained variance in P. alleni and B. flumineum survival, respectively. Thus, risk to non-target organisms is well predicted by pesticide class. Identifying insecticides that pose low risk to aquatic macroarthropods might help meet increased demands for food while mitigating against potential negative effects on ecosystem functions. PMID:25966044

  13. In vitro inhibition of acetylcholinesterase from four marine species by organophosphates and carbamates

    SciTech Connect

    Galgani, F.; Bocquene, G. )

    1990-08-01

    The literature on the biological, physical, and pharmaceutical chemistry of cholinesterase is considerable and includes data on activators and inhibitors. Most of the work on specific anticholinesterasic agents has been concerned with carbamates and organophosphates. Because of the sensitivity of acetylcholinesterase to carbamates and organophosphates, the enzyme has been used as a biochemical indicator of pollution by these agents. However, the chemical reactivity of such chemicals has not been correlated with their effect on Ache and it is impossible to accurately predict biological effects based only on structure. The objectives of this study were to investigate the sensitivity of various marine animals to both organo-phosphates and carbamates. The study was conducted by assessing the in vitro effect of five organophosphates and three carbamates on acetylcholinesterase activity from the muscle of the shrimp Palaemon serratus, the fishes Scomber and Pleuronectes platessa, and from the whole mussels Mytilus edulis. All these species could be used for the monitoring of effect of pollutants.

  14. Pesticide loadings of select organophosphate and pyrethroid pesticides in urban public housing.

    EPA Science Inventory

    We investigated the magnitude and distribution of pyrethroid and organophosphate pesticide loadings within public housing dwellings in Boston, Massachusetts and compared the results using various sampling methods. We collected dust matrices from living room and kitchen in 42 apar...

  15. REMOTE BIOSENSOR FOR IN SITU MONITORING OF ORGANOPHOSPHATE NERVE AGENTS. (R823663)

    EPA Science Inventory

    A remote electrochemical biosensor for field monitoring of organophosphate nerve agents is described. The new sensor relies on the coupling of the effective biocatalytic action of organophosphorus hydrolase (OPH) with a submersible amperometric probe design. This combination resu...

  16. DETOXIFICATION OF ORGANOPHOSPHATE PESTICIDES BY IMMOBILIZED ESCHERICHIA COLI EXPRESSING ORGANOPHOSPHORUS HYDROLASE ON CELL SURFACE. (R823663)

    EPA Science Inventory

    An improved whole-cell technology for detoxifying organophosphate nerve agents was recently developed based on genetically engineered Escherichia coli with organophosphorus hydrolase anchored on the surface. This article reports the immobilization of these novel biocatalys...

  17. ORGANOPHOSPHATE PESTICIDE DEGRADATION IN THE PRESENCE OF NATURALLY OCCURRING AQUATIC CONSTITUENTS UNDER DRINKING WATER TREATMENT CONDITIONS

    EPA Science Inventory

    Little work to date has solely investigated the kinetics and pathways of pesticide transformations under drinking water treatment conditions. Free chlorine has been found to react with s-triazine, carbamate, and organophosphate pesticides. However, these experimental conditions...

  18. Structural Characterization and Reversal of the Natural Organophosphate Resistance of a D-Type Esterase, Saccharomyces cerevisiae S-Formylglutathione Hydrolase

    SciTech Connect

    Legler,P.; Kumaran, D.; Swaminathan, S.; Studier, F.; Millard, C.

    2008-01-01

    Saccharomyces cerevisiae expresses a 67.8 kDa homodimeric serine thioesterase, S-formylglutathione hydrolase (SFGH), that is 39.9% identical with human esterase D. Both enzymes possess significant carboxylesterase and S-formylglutathione thioesterase activity but are unusually resistant to organophosphate (OP) inhibitors. We determined the X-ray crystal structure of yeast (y) SFGH to 2.3 Angstroms resolution by multiwavelength anomalous dispersion and used the structure to guide site-specific mutagenesis experiments addressing substrate and inhibitor reactivity. Our results demonstrate a steric mechanism of OP resistance mediated by a single indole ring (W197) located in an enzyme 'acyl pocket'. The W197I substitution enhances ySFGH reactivity with paraoxon by >1000-fold (kiW197I = 16 {+-} 2 mM-1 h-1), thereby overcoming natural OP resistance. W197I increases the rate of OP inhibition under pseudo-first-order conditions but does not accelerate OP hydrolysis. The structure of the paraoxon-inhibited W197I variant was determined by molecular replacement (2.2 Angstroms); it revealed a stabilized sulfenic acid at Cys60. Wild-type (WT) ySFGH is inhibited by thiol reactive compounds and is sensitive to oxidation; thus, the cysteine sulfenic acid may play a role in the regulation of a 'D-type' esterase. The structure of the W197I variant is the first reported cysteine sulfenic acid in a serine esterase. We constructed five Cys60/W197I variants and show that introducing a positive charge near the oxyanion hole, W197I/C60R or W197I/C60K, results in a further enhancement of the rates of phosphorylation with paraoxon (ki = 42 or 80 mM-1 h-1, respectively) but does not affect the dephosphorylation of the enzyme. We also characterized three histidine substitutions near the oxyanion hole, G57H, L58H, and M162H, which significantly decrease esterase activity.

  19. THE MUSCARINIC ANTAGONIST SCOPOLAMINE ATTENUATES CHLORPYRIFOS INDUCED HYPOTHERMIA IN THE DEVELOPING RAT.

    EPA Science Inventory

    Chlorpyrifos (CHP), an anticholinesterase organophosphate (OP) pesticide, induces acute hypothermia in adult and developing rats. Previously we demonstrated that thermoregulation in preweanling pups is markedly more sensitive to the neurotoxic effects of CHP than in adults. The c...

  20. A visible light photoelectrochemical biosensor coupling enzyme-inhibition for organophosphates monitoring based on a dual-functional Cd(0.5)Zn(0.5)S-reduced graphene oxide nanocomposite.

    PubMed

    Liu, Qian; Cai, Jianrong; Huan, Juan; Dong, Xiaoya; Wang, Chengke; Qiu, Baijing; Wang, Kun

    2014-03-01

    A novel visible light photoelectrochemical (PEC) platform coupled with enzyme-inhibition for rapid and sensitive determination of organophosphates (OPs) was constructed based on a dual-functional Cd0.5Zn0.5S-reduced graphene oxide (Cd0.5Zn0.5S-rGO) nanocomposite. Due to the inherent biocompatibility of the Cd0.5Zn0.5S-rGO nanocomposite, acetylcholinesterase (AChE) immobilized on the Cd0.5Zn0.5S-rGO modified electrode can hydrolyze acetylthiocholine chloride into thiocholine, which could increase the photocurrent of the enzyme electrode, and the further inhibition of OPs on the enzyme electrode could decrease the photocurrent response. Based on the notable change in the PEC response of the AChE-Cd0.5Zn0.5S-rGO modified electrode and using Dursban as a model, a simple and effective way for PEC monitoring of OPs is proposed, which showed a wide linear range of 0.001-1 μg mL(-1) with a low detection limit of 0.3 ng mL(-1) (S/N = 3). Moreover, the biosensor was successfully challenged with water samples, demonstrating a new method for rapid and sensitive screening/evaluating exposure to organophosphorus pesticides and other hazardous substances.

  1. Organophosphate hydrolases as catalytic bioscavengers of organophosphorus nerve agents.

    PubMed

    Trovaslet-Leroy, Marie; Musilova, Lucie; Renault, Frédérique; Brazzolotto, Xavier; Misik, Jan; Novotny, Ladislav; Froment, Marie-Thérèse; Gillon, Emilie; Loiodice, Mélanie; Verdier, Laurent; Masson, Patrick; Rochu, Daniel; Jun, Daniel; Nachon, Florian

    2011-09-25

    Bioscavengers are molecules able to neutralize neurotoxic organophosphorus compounds (OP) before they can reach their biological target. Human butyrylcholinesterase (hBChE) is a natural bioscavenger each molecule of enzyme neutralizing one molecule of OP. The amount of natural enzyme is insufficient to achieve good protection. Thus, different strategies have been envisioned. The most straightforward consists in injecting a large dose of highly purified natural hBChE to increase the amount of bioscavenger in the bloodstream. This proved to be successful for protection against lethal doses of soman and VX but remains expensive. An improved strategy is to regenerate prophylactic cholinesterases (ChE) by administration of reactivators after exposure. But broad-spectrum efficient reactivators are still lacking, especially for inhibited hBChE. Cholinesterase mutants capable of reactivating spontaneously are another option. The G117H hBChE mutant has been a prototype. We present here the Y124H/Y72D mutant of human acetylcholinesterase; its spontaneous reactivation rate after V-agent inhibition is increased up to 110 fold. Catalytic bioscavengers, enzymes capable of hydrolyzing OP, present the best alternative. Mesophilic bacterial phosphotriesterase (PTE) is a candidate with good catalytic efficiency. Its enantioselectivity has been enhanced against the most potent OP isomers by rational design. We show that PEGylation of this enzyme improves its mean residence time in the rat blood stream 24-fold and its bioavailability 120-fold. Immunogenic issues remain to be solved. Human paraoxonase 1 (hPON1) is another promising candidate. However, its main drawback is that its phosphotriesterase activity is highly dependent on its environment. Recent progress has been made using a mammalian chimera of PON1, but we provide here additional data showing that this chimera is biochemically different from hPON1. Besides, the chimera is expected to suffer from immunogenic issues. Thus, we

  2. Urinary Metabolites of Organophosphate and Pyrethroid Pesticides and Behavioral Problems in Canadian Children

    PubMed Central

    Oulhote, Youssef

    2013-01-01

    Background: Exposure to organophosphate pesticides has been associated with neurobehavioral deficits in children, although data on low levels of exposure experienced by the general population are sparse. Pyrethroids are insecticides rapidly gaining popularity, and epidemiological evidence on their potential effects is lacking. Objective: We examined the association between exposure to organophosphate and pyrethroid pesticides, indicated by urinary metabolites, and parentally reported behavioral problems in children. Methods: We used data on children 6–11 years of age from the Canadian Health Measures Survey (2007–2009). We used logistic regressions to estimate odds ratios (ORs) for high scores on the Strengths and Difficulties Questionnaire (SDQ), which may indicate behavioral problems, in association with concentrations of pyrethroid and organophosphate metabolites in the urine of 779 children, adjusting for covariates (sex, age, race/ethnicity, income, parental education, blood lead levels, maternal smoking during pregnancy, and others). Results: At least one urinary metabolite for organophosphates was detected in 91% of children, and for pyrethroids in 97% of children. Organophosphate metabolites were not significantly associated with high SDQ scores. The pyrethroid metabolite cis-DCCA [3-(2,2-dichlorovinyl)-2,2-dimethylycyclopropane carboxylic acid] was significantly associated with high scores for total difficulties on the SDQ (OR for a 10-fold increase = 2.0; 95% CI: 1.1, 3.6), and there was a nonsignificant association with trans-DCCA (OR = 1.6; 95% CI: 0.9, 3.0). Conclusion: In contrast with previous studies, we did not observe an association between exposure to organophosphate pesticides and behavioral scores in children. However, some pyrethroid urinary metabolites were associated with a high level of parent-reported behavioral problems. Longitudinal studies should be conducted on the potential risks of pyrethroids. Citation: Oulhote Y, Bouchard MF

  3. Phylogenetic diversity and metagenomics of candidate division OP3.

    PubMed

    Glöckner, Jana; Kube, Michael; Shrestha, Pravin Malla; Weber, Marc; Glöckner, Frank Oliver; Reinhardt, Richard; Liesack, Werner

    2010-05-01

    Except for environmental 16S rRNA gene sequences, no information is available for members of the candidate division OP3. These bacteria appear to thrive in anoxic environments, such as marine sediments, hypersaline deep sea, freshwater lakes, aquifers, flooded paddy soils and methanogenic bioreactors. The 16S rRNA phylogeny suggests that OP3 belongs to the Planctomycetes/Verrucomicrobia/Chlamydiae (PVC) superphylum. Metagenomic fosmid libraries were constructed from flooded paddy soil and screened for 16S rRNA gene-containing fragments affiliated with the PVC superphylum. The screening of 63 000 clones resulted in 23 assay-positive fosmids, of which three clones were affiliated with OP3. The 16S rRNA gene sequence divergence between the fragments OP3/1, OP3/2 and OP3/3 ranges from 18% to 25%, indicating that they belong to different OP3 subdivisions. The 23S rRNA phylogeny confirmed the membership of OP3 in the PVC superphylum. Sequencing the OP3 fragments resulted in a total of 105 kb of genomic information and 90 ORFs, of which 47 could be assigned a putative function and 11 were conserved hypothetical. Using BLASTP searches, a high proportion of ORFs had best matches to homologues from Deltaproteobacteria, rather than to those of members of the PVC superphylum. On the fragment OP3/3, a cluster of nine ORFs was predicted to encode the bacterial NADH dehydrogenase I. Given the high proportion of homologues present in deltaproteobacteria and anoxic conditions in the natural environment of OP3 bacteria, the detection of NADH dehydrogenase I may suggest an anaerobic respiration mode. Oligonucleotide frequencies calculated for OP3/1, OP3/2 and OP/3 show high intraphylum correlations. This novel sequence information could therefore be used to identify OP3-related fragments in large metagenomic data sets using marker gene-independent procedures in the future. In addition to the OP3 fragments, a single metagenomic fragment affiliated with the candidate division BRC1 was

  4. Organophosphate Esters in Canadian Arctic Air: Occurrence, Levels and Trends.

    PubMed

    Sühring, Roxana; Diamond, Miriam L; Scheringer, Martin; Wong, Fiona; Pućko, Monika; Stern, Gary; Burt, Alexis; Hung, Hayley; Fellin, Philip; Li, Henrik; Jantunen, Liisa M

    2016-07-19

    Fourteen organophosphate esters (OPEs) were measured in the filter fraction of 117 active air samples from yearly ship-based sampling campaigns (2007-2013) and two land-based stations in the Canadian Arctic, to assess trends and long-range transport potential of OPEs. Four OPEs were detected in up to 97% of the samples, seven in 50% or less of the samples, and three were not detected. Median concentrations of ∑OPEs were 237 and 50 pg m(-3) for ship- and land-based samples, respectively. Individual median concentrations ranged from below detection to 119 pg m(-3) for ethanol, 2-chloro-, phosphate (3:1) (TCEP). High concentrations of up to 2340 pg m(-3) were observed for Tri-n-butyl phosphate (TnBP) at a land-based sampling location in Resolute Bay from 2012, whereas it was only detected in one ship-based sample at a concentration below 100 pg m(-3). Concentrations of halogenated OPEs seemed to be driven by river discharge from the Nelson and Churchill Rivers (Manitoba) and Churchill River and Lake Melville (Newfoundland and Labrador). In contrast, nonhalogenated OPE concentrations appeared to have diffuse sources or local sources close to the land-based sampling stations. Triphenyl phosphate (TPhP) showed an apparent temporal trend with a doubling-time of 11 months (p = 0.044). The results emphasize the increasing relevance of halogenated and nonhalogenated OPEs as contaminants in the Arctic.

  5. Inhibition of monocyte esterase activity by organophosphate insecticides.

    PubMed

    Lee, M J; Waters, H C

    1977-11-01

    Organophosphate insecticides, such as Vapona, Naled, and Rabon, are highly potent inhibitors of an enzyme found in human monocytes. The enzyme, a specific monocyte esterase, could be inhibited by Vapona in blood samples via airborne contamination at levels easily achieved from commercial slow-release insecticide strips. Fifty percent inhibition (I50)--as measured on the Hemalog D (Technicon Corp.)--occurred at solution concentrations of 0.22, 1.5, and 2.6 X 10(-6) g/liter for Vapona, Rabon, and Naled, respectively. Parathion (a thiophosphate) and Baygon (a carbamate) were less potent, with I50 values of 3.7 X 10(-5) and 1.5 X 10(-4) g/liter, respectively. Dursban (another thiophosphate) and Carbaryl (a carbamate) showed only marginal inhibition. Eserine, malathion, nicotine and pyrethrum had no inhibitory effect up to 0.5 g/liter. The occurrence of this effect in vivo has not yet been shown, nor is it clear what the implications of such an effect would be. The inhibition of this enzyme by airborne contaminants, however, may interfere with the proper functioning of the Hemalog D. PMID:907842

  6. Occurrence of organophosphate flame retardants in drinking water from China.

    PubMed

    Li, Jun; Yu, Nanyang; Zhang, Beibei; Jin, Ling; Li, Meiying; Hu, Mengyang; Zhang, Xiaowei; Wei, Si; Yu, Hongxia

    2014-05-01

    Several organophosphate flame retardants (OPFRs) have been identified as known or suspected carcinogens or neurotoxic substances. Given the potential health risks of these compounds, we conducted a comprehensive survey of nine OPFRs in drinking water in China. We found total concentrations of OPFRs in tap water ranging from 85.1 ng/L to 325 ng/L, and tris(2-butoxyethyl) phosphate (TBEP), triphenyl phosphate (TPP), and tris(2-chloroisopropyl) phosphate (TCPP) were the most common components. Similar OPFR concentrations and profiles were observed in water samples processed through six different waterworks in Nanjing, China. However, boiling affected OPFR levels in drinking water by either increasing (e.g., TBEP) or decreasing (e.g., tributyl phosphate, TBP) concentrations depending on the particular compound and the state of the indoor environment. We also found that bottled water contained many of the same major OPFR compounds with concentrations 10-25% lower than those in tap water, although TBEP contamination in bottled water remained a concern. Finally, we concluded that the risk of ingesting OPFRs through drinking water was not a major health concern for either adults or children in China. Nevertheless, drinking water ingestion represents an important exposure pathway for OPFRs.

  7. Organophosphate Esters in Canadian Arctic Air: Occurrence, Levels and Trends.

    PubMed

    Sühring, Roxana; Diamond, Miriam L; Scheringer, Martin; Wong, Fiona; Pućko, Monika; Stern, Gary; Burt, Alexis; Hung, Hayley; Fellin, Philip; Li, Henrik; Jantunen, Liisa M

    2016-07-19

    Fourteen organophosphate esters (OPEs) were measured in the filter fraction of 117 active air samples from yearly ship-based sampling campaigns (2007-2013) and two land-based stations in the Canadian Arctic, to assess trends and long-range transport potential of OPEs. Four OPEs were detected in up to 97% of the samples, seven in 50% or less of the samples, and three were not detected. Median concentrations of ∑OPEs were 237 and 50 pg m(-3) for ship- and land-based samples, respectively. Individual median concentrations ranged from below detection to 119 pg m(-3) for ethanol, 2-chloro-, phosphate (3:1) (TCEP). High concentrations of up to 2340 pg m(-3) were observed for Tri-n-butyl phosphate (TnBP) at a land-based sampling location in Resolute Bay from 2012, whereas it was only detected in one ship-based sample at a concentration below 100 pg m(-3). Concentrations of halogenated OPEs seemed to be driven by river discharge from the Nelson and Churchill Rivers (Manitoba) and Churchill River and Lake Melville (Newfoundland and Labrador). In contrast, nonhalogenated OPE concentrations appeared to have diffuse sources or local sources close to the land-based sampling stations. Triphenyl phosphate (TPhP) showed an apparent temporal trend with a doubling-time of 11 months (p = 0.044). The results emphasize the increasing relevance of halogenated and nonhalogenated OPEs as contaminants in the Arctic. PMID:27309668

  8. Age-related differences in acute neurotoxicity produced by mevinphos, monocrotophos, dicrotophos, and phosphamidon

    EPA Science Inventory

    Age-related differences in the acute neurotoxicity of cholinesterase (ChE)-inhibiting pesticides have been well-studied for a few organophosphates, but not for many others. In this study, we directly compared dose-responses using brain and red blood cell (RBC) ChE measurements, a...

  9. Estimates of Tiber River organophosphate pesticide loads to the Tyrrhenian Sea and ecological risk.

    PubMed

    Montuori, Paolo; Aurino, Sara; Garzonio, Fatima; Sarnacchiaro, Pasquale; Polichetti, Salvatore; Nardone, Antonio; Triassi, Maria

    2016-07-15

    The organophosphate pesticides pollution in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. Eight selected organophosphate pesticides (diazinon, dimethoate, malathion, chlorpyrifos, pirimiphos-methyl, fenitrothion, methidathion, tolclofos-methyl) were determined in the water dissolved phase, suspended particulate matter and sediment samples collected from 21 sites in different seasons. Total organophosphate pesticides concentrations ranged from 0.40 to 224.48ngL(-1) in water (as the sum of the water dissolved phase and suspended particulate matter) and from 1.42 to 68.46ngg(-1) in sediment samples. Contaminant discharges of organophosphate pesticides into the sea were calculated in about 545.36kgyear(-1) showing that this river should be consider as one of the main contribution sources of organophosphate pesticides to the Tyrrhenian Sea. In relation to the eco-toxicological assessment, the concentrations of most OPPs in the water and sediments from the Tiber River and its estuary were lower than guideline values. PMID:27065443

  10. Cognitive disorders and occupational exposure to organophosphates: results from the PHYTONER study.

    PubMed

    Blanc-Lapierre, Audrey; Bouvier, Ghislaine; Gruber, Anne; Leffondré, Karen; Lebailly, Pierre; Fabrigoule, Colette; Baldi, Isabelle

    2013-05-15

    The involvement of organophosphate insecticides in cognitive disorders is supported by epidemiologic and biological evidence, but the effects of long-term exposure remain debated. We studied the association between organophosphate exposure and cognitive performance in vine workers from the PHYTONER study cohort in the Bordeaux area of France. Results from interviews of 614 subjects conducted at the 4-year follow-up between 2001 and 2003 were analyzed. Exposure to pesticides since 1950 was assessed with cumulative exposure scores for 34 organophosphates combining an historical crop-exposure pesticide matrix and field exposure studies, taking into account the characteristics of treatment (mixing, spraying, equipment cleaning) and reentry tasks. For the 11 organophosphates retained in the analysis, exposure (ever vs. never) was associated with low cognitive performance. No dose-effect relationship was found, but an increased risk was observed with a 50-mg increase in the cumulative score, which was greater with mevinphos (Benton Visual Retention Test: odds ratio = 3.26, 95% confidence interval: 1.54, 6.88; Trail Making Test, part A: odds ratio = 3.03, 95% confidence interval: 1.39, 6.62). Our results support the hypothesis that cognitive disorders observed in vine workers may be associated with exposure to specific organophosphates. PMID:23535900

  11. Developmental exposure of zebrafish larvae to organophosphate flame retardants causes neurotoxicity.

    PubMed

    Sun, Liwei; Xu, Wenbin; Peng, Tao; Chen, Haigang; Ren, Lin; Tan, Hana; Xiao, Dan; Qian, Haifeng; Fu, Zhengwei

    2016-01-01

    With the gradual ban on brominated flame retardants (FRs), the application of organophosphate flame retardants (OPFRs) has increased remarkably. Considering the structural similarity between OPFRs and organophosphate pesticides, hypotheses that OPFRs may interfere with neurodevelopment as organophosphate pesticides are reasonable. In this study, the neurotoxicity of three OPFRs, including tri-n-butyl phosphate (TNBP), tris (2-butoxyethyl) phosphate (TBOEP) and tris (2-chloroethyl) phosphate (TCEP), was evaluated in zebrafish larvae and then compared with the neurotoxicity of organophosphate pesticide chlorpyrifos (CPF). The results showed that similar to CPF, exposure to OPFRs for 5days resulted in significant changes in locomotor behavior, either in free swimming or in photomotor response. However, given the transcriptional changes that occur in nervous system genes in response to OPFRs and CPF, as well as the altered enzyme activity of AChE and its mRNA level, the underlying mechanisms for neurotoxicity among these organophosphate chemicals might be varied. In summary, the results confirm the potential neurodevelopmental toxicity of OPFRs and underscore the importance of identifying the mechanistic targets of the OPFRs with specific moieties. Furthermore, as the neurobehavioral responses are well conserved among vertebrates and the exposure of children to OPFRs is significant, a thorough assessment of the risk of OPFRs exposure during early development should be highly emphasized in future studies. PMID:27018022

  12. Developmental exposure of zebrafish larvae to organophosphate flame retardants causes neurotoxicity.

    PubMed

    Sun, Liwei; Xu, Wenbin; Peng, Tao; Chen, Haigang; Ren, Lin; Tan, Hana; Xiao, Dan; Qian, Haifeng; Fu, Zhengwei

    2016-01-01

    With the gradual ban on brominated flame retardants (FRs), the application of organophosphate flame retardants (OPFRs) has increased remarkably. Considering the structural similarity between OPFRs and organophosphate pesticides, hypotheses that OPFRs may interfere with neurodevelopment as organophosphate pesticides are reasonable. In this study, the neurotoxicity of three OPFRs, including tri-n-butyl phosphate (TNBP), tris (2-butoxyethyl) phosphate (TBOEP) and tris (2-chloroethyl) phosphate (TCEP), was evaluated in zebrafish larvae and then compared with the neurotoxicity of organophosphate pesticide chlorpyrifos (CPF). The results showed that similar to CPF, exposure to OPFRs for 5days resulted in significant changes in locomotor behavior, either in free swimming or in photomotor response. However, given the transcriptional changes that occur in nervous system genes in response to OPFRs and CPF, as well as the altered enzyme activity of AChE and its mRNA level, the underlying mechanisms for neurotoxicity among these organophosphate chemicals might be varied. In summary, the results confirm the potential neurodevelopmental toxicity of OPFRs and underscore the importance of identifying the mechanistic targets of the OPFRs with specific moieties. Furthermore, as the neurobehavioral responses are well conserved among vertebrates and the exposure of children to OPFRs is significant, a thorough assessment of the risk of OPFRs exposure during early development should be highly emphasized in future studies.

  13. Implications of estimates of residential organophosphate exposure from dialkylphosphates (DAPs) and their relevance to risk.

    PubMed

    Krieger, R I; Chen, L; Ginevan, M; Watkins, D; Cochran, R C; Driver, J H; Ross, J H

    2012-11-01

    Recent epidemiological studies have claimed to associate a variety of toxicological effects of organophosphorus insecticides (OPs) and residential OP exposure based on the dialkyl phosphates (DAPs; metabolic and environmental breakdown products of OPs) levels in the urine of pregnant females. A key premise in those epidemiology studies was that the level of urinary DAPs was directly related to the level of parent OP exposure. Specific chemical biomarkers and DAPs representing absorbed dose of OPs are invaluable to reconstruct human exposures in prospective occupational studies and even in non-occupational studies when exposure to a specific OP can be described. However, measurement of those detoxification products in urine without specific knowledge of insecticide exposure is insufficient to establish OP insecticide exposure. DAPs have high oral bioavailability and are ubiquitously present in produce at concentrations several-fold greater than parent OPs. Studies relying on DAPs as an indicator of OP exposure that lack credible information on proximate OP exposure are simply measuring DAP exposure and misattributing OP exposure. PMID:22922654

  14. Aryl organophosphate flame retardants induced cardiotoxicity during zebrafish embryogenesis: by disturbing expression of the transcriptional regulators.

    PubMed

    Du, Zhongkun; Wang, Guowei; Gao, Shixiang; Wang, Zunyao

    2015-04-01

    As a result of the ban on some brominated flame retardants (BFRs), the use of organophosphate flame retardants (OPFRs) increases, and they are detected in multi-environment media at higher frequency and concentrations. However, the toxicity data of OPFRs, especially those on developmental toxicology are quite limited, which prevents an accurate evaluation of their environmental and health risk. Because a previous study reported that two aryl-OPFRs induced cardiotoxicity during zebrafish embryogenesis, we designed experiments to compare the heart developmental toxicity of a series of aryl-OPFRs with alkyl-OPFRs and explored possible internal mechanism. First, acute toxicity of 9 frequently used OPFRs were studied with zebrafish embryos (2-96 hpf). By comparing the LC50 and EC50 (pericardium edema) data, two aryl-OPFRs, triphenyl phosphate (TPhP) and cresyl diphenyl phosphate (CDP) showed greater heart developmental toxicity than the others. It was also found that the acute toxicity of OPFRs varied mainly depending on their hydrophobicity. Further study on the cardiotoxicity of TPhP and CDP showed that the cardiac looping progress can be impeded by 0.10mg/L TPhP or CDP exposure. Bradycardia and reduction of myocardium were also observed in 0.50 and 1.0mg/L TPhP groups and 0.10, 0.50, and 1.0mg/L CDP groups. 0-48 hpf is the vulnerable window of zebrafish cardiogenesis that can be easily affected by TPhP and CDP. RT-qPCR measurement on the expressions of key transcriptional regulators in cardiogenesis showed that BMP4, NKX2-5, and TBX5 were significantly inhibited at the exposure points of 12 hpf and 24 hpf which may be the internal factors related to the heart developmental toxicity. As zebrafish is a good model organism for human health study, the present results call for a greater attention to the health risk of fetus in pregnant women exposed to such OPFRs. PMID:25661707

  15. Role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to organophosphate pesticides.

    PubMed

    Singh, Satyender; Kumar, Vivek; Vashisht, Kapil; Singh, Priyanka; Banerjee, Basu Dev; Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen; Jain, Sudhir Kumar; Rai, Arvind

    2011-11-15

    Organophosphate pesticides (OPs) are primarily metabolized by several xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticide-exposed workers. The present study was designed to determine the role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to OPs. We examined 284 subjects including 150 workers occupationally exposed to OPs and 134 normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using PCR-RFLP. The results revealed that the PONase activity toward paraoxonase and AChE activity was found significantly lowered in workers as compared to control subjects (p<0.001). Workers showed significantly higher DNA damage compared to control subjects (14.37±2.15 vs. 6.24±1.37 tail% DNA, p<0.001). Further, the workers with CYP2D6*3PM and PON1 (QQ and MM) genotypes were found to have significantly higher DNA damage when compared to other genotypes (p<0.05). In addition, significant increase in DNA damage was also observed in workers with concomitant presence of certain CYP2D6 and PON1 (Q192R and L55M) genotypes which need further extensive studies. In conclusion, the results indicate that the PON1 and CYP2D6 genotypes can modulate DNA damage elicited by some OPs possibly through gene-environment interactions.

  16. Tera-Ops Processing for ATR

    NASA Technical Reports Server (NTRS)

    Udomkesmalee, Suraphol; Padgett, Curtis; Zhu, David; Lung, Gerald; Howard, Ayanna

    2000-01-01

    A three-dimensional microelectronic device (3DANN-R) capable of performing general image convolution at the speed of 1012 operations/second (ops) in a volume of less than 1.5 cubic centimeter has been successfully built under the BMDO/JPL VIGILANTE program. 3DANN-R was developed in partnership with Irvine Sensors Corp., Costa Mesa, California. 3DANN-R is a sugar-cube-sized, low power image convolution engine that in its core computation circuitry is capable of performing 64 image convolutions with large (64x64) windows at video frame rates. This paper explores potential applications of 3DANN-R such as target recognition, SAR and hyperspectral data processing, and general machine vision using real data and discuss technical challenges for providing deployable systems for BMDO surveillance and interceptor programs.

  17. 2011 Internship & Co-Op Survey. Research Brief

    ERIC Educational Resources Information Center

    National Association of Colleges and Employers (NJ1), 2011

    2011-01-01

    The National Association of Colleges and Employers' (NACE's) "2011 Internship & Co-op Survey" indicates that internships are an integral and ever-important part of the college recruiting scene. The survey finds that employers expect to increase internship hiring by about 7 percent this year and co-op positions by nearly 9 percent. Furthermore,…

  18. Inhalation a significant exposure route for chlorinated organophosphate flame retardants.

    PubMed

    Schreder, Erika D; Uding, Nancy; La Guardia, Mark J

    2016-05-01

    Chlorinated organophosphate flame retardants (ClOPFRs) are widely used as additive flame retardants in consumer products including furniture, children's products, building materials, and textiles. Tests of indoor media in homes, offices, and other environments have shown these compounds are released from products and have become ubiquitous indoor pollutants. In house dust samples from Washington State, U.S.A., ClOPFRs were the flame retardants detected in the highest concentrations. Two ClOPFRs, tris(1,3-dichloro-2-propyl)phosphate (TDCPP or TDCIPP) and tris(2-chloroethyl)phosphate (TCEP), have been designated as carcinogens, and there is growing concern about the toxicity of the homologue tris(1-chloro-2-propyl)phosphate (TCPP or TCIPP). In response to concerns about exposure to these compounds, the European Union and a number of U.S. states have taken regulatory action to restrict their use in certain product categories. To better characterize exposure to ClOPFRs, inhalation exposure was assessed using active personal air samplers in Washington State with both respirable and inhalable particulate fractions collected to assess the likelihood particles penetrate deep into the lungs. Concentrations of ∑ClOPFRs (respirable and inhalable) ranged from 97.1 to 1190 ng m(-3) (mean 426 ng m(-3)), with TCPP detected at the highest concentrations. In general, higher levels were detected in the inhalable particulate fraction. Total intake of ClOPFRs via the inhalation exposure route was estimated to exceed intake via dust ingestion, indicating that inhalation is an important route that should be taken into consideration in assessments of these compounds.

  19. In vitro inhibition of lysine decarboxylase activity by organophosphate esters.

    PubMed

    Wang, Sufang; Wan, Bin; Zhang, Lianying; Yang, Yu; Guo, Liang-Hong

    2014-12-01

    Organophosphate esters (OPEs), a major group of organophosphorus flame retardants, are regarded as emerging environmental contaminants of health concern. Amino acid decarboxylases catalyze the conversion of amino acids into polyamines that are essential for cell proliferation, hypertrophy and tissue growth. In this paper, inhibitory effect of twelve OPEs with aromatic, alkyl or chlorinated alkyl substituents on the activity of lysine decarboxylase (LDC) was assessed quantitatively with an economic and label-free fluorescence sensor and cell assay. The sensor comprises a macrocyclic host (cucurbit[7]uril) and a fluorescent dye (acridine orange) reporter. The twelve OPEs were found to vary in their capacity to inhibit LDC activity. Alkyl group substituted OPEs had no inhibitory effect. By contrast, six OPEs substituted with aromatic or chlorinated alkyl groups inhibited LDC activity significantly with IC50 ranging from 1.32 μM to 9.07 μM. Among them, the inhibitory effect of tri-m-cresyl phosphate (TCrP) was even more effective as an inhibitor than guanosine 5'-diphosphate-3'-diphosphate (ppGpp) (1.60 μM), an LDC natural inhibitor in vivo. Moreover, at non-cytotoxic concentrations, these six OPEs showed perceptible inhibitory effects on LDC activity in PC12 living cells, and led to a marked loss in the cadaverine content. Molecular docking analysis of the LDC/OPE complexes revealed that different binding modes contribute to the difference in their inhibitory effect. Our finding suggested that LDC, as a new potential biological target of OPEs, might be implicated in toxicological and pathogenic mechanism of OPEs. PMID:25264276

  20. Inhalation a significant exposure route for chlorinated organophosphate flame retardants.

    PubMed

    Schreder, Erika D; Uding, Nancy; La Guardia, Mark J

    2016-05-01

    Chlorinated organophosphate flame retardants (ClOPFRs) are widely used as additive flame retardants in consumer products including furniture, children's products, building materials, and textiles. Tests of indoor media in homes, offices, and other environments have shown these compounds are released from products and have become ubiquitous indoor pollutants. In house dust samples from Washington State, U.S.A., ClOPFRs were the flame retardants detected in the highest concentrations. Two ClOPFRs, tris(1,3-dichloro-2-propyl)phosphate (TDCPP or TDCIPP) and tris(2-chloroethyl)phosphate (TCEP), have been designated as carcinogens, and there is growing concern about the toxicity of the homologue tris(1-chloro-2-propyl)phosphate (TCPP or TCIPP). In response to concerns about exposure to these compounds, the European Union and a number of U.S. states have taken regulatory action to restrict their use in certain product categories. To better characterize exposure to ClOPFRs, inhalation exposure was assessed using active personal air samplers in Washington State with both respirable and inhalable particulate fractions collected to assess the likelihood particles penetrate deep into the lungs. Concentrations of ∑ClOPFRs (respirable and inhalable) ranged from 97.1 to 1190 ng m(-3) (mean 426 ng m(-3)), with TCPP detected at the highest concentrations. In general, higher levels were detected in the inhalable particulate fraction. Total intake of ClOPFRs via the inhalation exposure route was estimated to exceed intake via dust ingestion, indicating that inhalation is an important route that should be taken into consideration in assessments of these compounds. PMID:26775187

  1. Frequencies of organophosphate resistance-associated mutations in the acetylcholinesterase gene of field collected olive fly (Bactrocera oleae) populations under different insecticide regimes.

    PubMed

    Başkurt, S Ibel; Doğaç, E; Taşkın, V; Taşkın, Belg In Göçmen

    2011-03-01

    In the present study, the frequencies of three organophosphate (OP) resistance-associated mutations in acetylcholinesterase gene of Bactrocera oleae (BoAce) populations collected from 8 different important olivegrowing areas in the west part of Turkey were determined. Populations were sampled from the areas that have been treated with only the pyrethroid α-cypermethrin; pyrethroids plus OPs; deltamethrin with pheromone eco-traps, and no insecticide treatment applied areas for many years. For Ile214Val and Gly488Ser point mutations PCR-RFLP and for Δ3Q deletion mutation PCR diagnostic tests were carried out. Seventy-two percent of the total individuals analyzed in the study were exhibited heterozygous genotype (RS) for both Ile214Val and Gly488Ser point and homozygous susceptible genotype (SS) for Δ3Q deletion mutations. This RS/RS/SS combination together with RS/RR/SS with the frequency of 13% were the most common two combinations observed in all of the populations under different insecticide regimes, even in the populations under no insecticide pressure for many years. Independent evaluation of the three mutations resulted in 0.450, 0.534 and 0.037 frequency values for the resistant alleles of 214Val, 488Ser and Δ3Q mutations, respectively. Among the studied populations, the frequencies of resistant alleles for the positions of 214 and 488 were not differed from each other. However, in 3 of the populations the frequency of the R allele of Δ3Q was zero and it changed between 0.025 and 0.100 in the remaining five populations. Results of this study contributed to the distribution pattern of the two point mutations in Europe and a pattern for Δ3Q mutation was determined for the first time in the field collected olive fly samples.

  2. [Health risk control for organophosphate pesticides in Mexico: challenges under the Free Trade Treaty].

    PubMed

    Ortega-Ceseña, J; Espinosa-Torres, F; López-Carrillo, L

    1994-01-01

    This paper discusses recent trends concerning the commercialization of pesticides in Mexico and focuses on organophosphates and their potential health risk impact. It points out the existing lack of knowledge on health effects associated to chronic exposure to organophosphate pesticides. A need for both toxicological and epidemiologic studies of chronic exposure is identified. Regulatory programs for pesticides in Mexico and the United States are also compared. The paper also addresses the possibility of effective enforcement of environmental and health regulations in Mexico as a result of more rigorous surveillance under NAFTA.

  3. Construction of a green fluorescent protein (GFP)-marked multifunctional pesticide-degrading bacterium for simultaneous degradation of organophosphates and γ-hexachlorocyclohexane.

    PubMed

    Yang, Chao; Liu, Ruihua; Yuan, Yulan; Liu, Jianli; Cao, Xiangyu; Qiao, Chuanling; Song, Cunjiang

    2013-02-13

    An autofluorescent whole-cell biocatalyst capable of simultaneously degrading organophosphates (OPs) and γ-hexachlorocyclohexane (γ-HCH) was constructed by display of organophosphorus hydrolase (OPH) and green fluorescent protein (GFP) fusion on the cell surface of a γ-HCH-degrading Sphingobium japonicum UT26 using the truncated ice nucleation protein (INPNC) as an anchoring motif. The surface localization of INPNC-OPH-GFP fusion was verified by cell fractionation, Western blot, proteinase accessibility, and immunofluorescence microscopy. Surface display of macromolecular OPH-GFP fusion (63 kDa) neither inhibits cell growth nor affects cell viability. In sterile and nonsterile soil samples, a mixture of parathion (100 mg kg(-1)) and γ-HCH (10 mg kg(-1)) could be degraded completely within 15 days when inoculated with the engineered UT26, and the strain could be easily monitored by fluorescence during bioremediation. These results indicate that the engineered UT26 is a promising multifunctional bacterium that could be used for the bioremediation of environments contaminated with multiple pesticides.

  4. Co-op Essay - Tour 1

    NASA Technical Reports Server (NTRS)

    Porter, Derrick

    2014-01-01

    The Mission Operations Directorate (MOD) is responsible for the training, planning and performance of all U.S. manned operations in space. Within this directorate all responsibilities are divided up into divisions. The EVA, Robotics & Crew Systems Operations Division performs ground operations and trains astronauts to carry out some of the more "high action" procedures in space. For example they orchestrate procedures like EVAs, or ExtraVehicular Activities (spacewalks), and robotics operations external to the International Space Station (ISS). The robotics branch of this division is responsible for the use of the Mobile Servicing System (MSS). This system is a combination of two robotic mechanisms and a series of equipment used to transport them on the ISS. The MSS is used to capture and position visiting vehicles, transport astronauts during EVAs, and perform external maintenance tasks on the ISS. This branch consists of two groups which are responsible for crew training and flight controlling, respectively. My first co-op tour took place Fall 2013. During this time I was given the opportunity to work in the robotics operations branch of the Mission Operations Directorate at NASA's Johnson Space Center. I was given a variety of tasks that encompassed, at a base level, all the aspects of the branch.

  5. FIBER-OPTIC BIOSENSOR FOR DIRECT DETERMINATION OF ORGANOPHOSPHATE NERVE AGENTS. (R823663)

    EPA Science Inventory

    A fiber-optic enzyme biosensor for the direct measurement of organophosphate nerve
    agents was developed. The basic element of this biosensor is organophosphorus hydrolase
    immobilized on a nylon membrane and attached to the common end of a bifurcated optical fiber
    bundle....

  6. Pyrethroid and DDT Resistance and Organophosphate Susceptibility among Anopheles spp. Mosquitoes, Western Kenya

    PubMed Central

    Wanjala, Christine L.; Mbugi, Jernard P.; Ototo, Edna; Gesuge, Maxwell; Afrane, Yaw A.; Atieli, Harrysone E.; Zhou, Guofa; Githeko, Andrew K.

    2015-01-01

    We conducted standard insecticide susceptibility testing across western Kenya and found that the Anopheles gambiae mosquito has acquired high resistance to pyrethroids and DDT, patchy resistance to carbamates, but no resistance to organophosphates. Use of non–pyrethroid-based vector control tools may be preferable for malaria prevention in this region. PMID:26583525

  7. CAN FLU-LIKE ILLNESS BE AN INDICATION OF RECENT ORGANOPHOSPHATE PESTICIDE EXPOSURE IN PRESCHOOL CHILDREN?

    EPA Science Inventory

    Can flu-like illness be an indication of recent organophosphate pesticide exposure in preschool children? P Mendola*, D Barr, D Walsh, S Hern, S Rhoney, L Needham, E Hilborn, M Gonzales, C Carty, G Robertson, J Creason (US EPA, ORD, NHEERL, Research Triangle Park, NC 27711)
    <...

  8. Pyrethroid and DDT Resistance and Organophosphate Susceptibility among Anopheles spp. Mosquitoes, Western Kenya.

    PubMed

    Wanjala, Christine L; Mbugi, Jernard P; Ototo, Edna; Gesuge, Maxwell; Afrane, Yaw A; Atieli, Harrysone E; Zhou, Guofa; Githeko, Andrew K; Yan, Guiyun

    2015-12-01

    We conducted standard insecticide susceptibility testing across western Kenya and found that the Anopheles gambiae mosquito has acquired high resistance to pyrethroids and DDT, patchy resistance to carbamates, but no resistance to organophosphates. Use of non-pyrethroid-based vector control tools may be preferable for malaria prevention in this region. PMID:26583525

  9. Pyrethroid and DDT Resistance and Organophosphate Susceptibility among Anopheles spp. Mosquitoes, Western Kenya.

    PubMed

    Wanjala, Christine L; Mbugi, Jernard P; Ototo, Edna; Gesuge, Maxwell; Afrane, Yaw A; Atieli, Harrysone E; Zhou, Guofa; Githeko, Andrew K; Yan, Guiyun

    2015-12-01

    We conducted standard insecticide susceptibility testing across western Kenya and found that the Anopheles gambiae mosquito has acquired high resistance to pyrethroids and DDT, patchy resistance to carbamates, but no resistance to organophosphates. Use of non-pyrethroid-based vector control tools may be preferable for malaria prevention in this region.

  10. RESIDENTIAL PESTICIDE USE AND URINARY ORGANOPHOSPHATE METABOLITES IN PRE-SCHOOL CHILDREN

    EPA Science Inventory

    Residential Pesticide Use and Urinary Organophosphate Metabolites in Pre-School Children
    CL Carty1, P Mendola1, D Barr2, L Needham2, D Walsh1

    1Epidemiology and Biomarkers Branch, Human Studies Division, National Health and Environmental Effects Research Laboratory, U.S....

  11. Draft Genome Sequence of Organophosphate-Degrading Ochrobactrum anthropi FRAF13

    PubMed Central

    Damania, Ashish

    2016-01-01

    Ochrobactrum anthropi FRAF13 was isolated from farmland soil in Jersey Village, Texas. FRAF13 is a bacterial microorganism with broad antibiotic resistance that possesses a number of metal-dependent β-lactam enzymes with secondary phosphotriesterase activity that can initiate the breakdown of organophosphate compounds. PMID:27103720

  12. Role of paraoxonase 1 (PON1) in organophosphate metabolism: Implications in neurodegenerative diseases

    SciTech Connect

    Androutsopoulos, Vasilis P.; Kanavouras, Konstantinos; Tsatsakis, Aristidis M.

    2011-11-15

    Organophosphate pesticides are a class of compounds that are widely used in agricultural and rural areas. Paraoxonase 1 (PON1) is a phase-I enzyme that is involved in the hydrolysis of organophosphate esters. Environmental poisoning by organophosphate compounds has been the main driving force of previous research on PON1 enzymes. Recent discoveries in animal models have revealed the important role of the enzyme in lipid metabolism. However although PON1 function is well established in experimental models, the contribution of PON1 in neurodegenerative diseases remains unclear. In this minireview we summarize the involvement of PON1 genotypes in the occurrence of Parkinson's disease, Alzheimer's disease and amyotrophic lateral sclerosis. A brief overview of latest epidemiological studies, regarding the two most important PON1 coding region polymorphisms PON1-L55M and PON1-Q192R is presented. Positive and negative associations of PON1 with disease occurrence are reported. Notably the MM and RR alleles contribute a risk enhancing effect for the development of some neurodegenerative diseases, which may be explained by the reduced lipoprotein free radical scavenging activity that may give rise to neuronal damage, through distinct mechanism. Conflicting findings that fail to support this postulate may represent the human population ethnic heterogeneity, different sample size and environmental parameters affecting PON1 status. We conclude that further epidemiological studies are required in order to address the exact contribution of PON1 genome in combination with organophosphate exposure in populations with neurodegenerative diseases.

  13. Acetylcholinesterase of Haematobia irritans (Diptera: Muscidae): Baculovirus expression, biochemical properties and organophosphate insensitivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study reports the baculovirus expression and biochemical characterization of recombinant acetylcholinesterase from Haematobia irritans (L) (rHiAChE) and the effect of the previously described G262A mutation on enzyme activity and sensitivity to selected organophosphates. The rHiAChE was confirm...

  14. Characterization of seizures induced by acute exposure to an organophosphate herbicide, glufosinate-ammonium.

    PubMed

    Calas, André-Guilhem; Perche, Olivier; Richard, Olivier; Perche, Astrid; Pâris, Arnaud; Lauga, Fabien; Herzine, Ameziane; Palomo, Jennifer; Ardourel, Marie-Yvonne; Menuet, Arnaud; Mortaud, Stéphane; Pichon, Jacques; Montécot-Dubourg, Céline

    2016-05-01

    Glufosinate-ammonium (GLA), the active component of a widely used herbicide, induces convulsions in rodents and humans. In mouse, intraperitoneal treatment with 75 mg/kg GLA generates repetitive tonic-clonic seizures associated with 100% mortality within 72 h after treatment. In this context, we characterized GLA-induced seizures, their histological consequences and the effectiveness of diazepam treatment. Epileptic discharges on electroencephalographic recordings appeared simultaneously in the hippocampus and the cerebral cortex. Diazepam treatment at 6 h immediately stopped the seizures and prevented animal death. However, intermittent seizures were recorded on electroencephalogram from 6 h after diazepam treatment until 24 h, but had disappeared after 15 days. In our model, neuronal activation (c-Fos immunohistochemistry) was observed 6 h after GLA exposure in the dentate gyrus, CA1, CA3, amygdala, piriform and entorhinal cortices, indicating the activation of the limbic system. In these structures, Fluoro-Jade C and Cresyl violet staining did not show neuronal suffering. However, astroglial activation was clearly observed at 24 h and 15 days after GLA treatment in the amygdala, piriform and entorhinal cortices by PCR quantitative, western blot and immunohistochemistry. Concomitantly, glutamine synthetase mRNA expression (PCR quantitative), protein expression (western blot) and enzymatic activity were upregulated. In conclusion, our study suggests that GLA-induced seizures: (a) involved limbic structures and (b) induced astrocytosis without neuronal degeneration as an evidence of a reactive astrocyte beneficial effect for neuronal protection. PMID:27031874

  15. Association between organophosphate pesticides exposure and thyroid hormones in floriculture workers

    SciTech Connect

    Lacasana, Marina; Lopez-Flores, Inmaculada; Rodriguez-Barranco, Miguel; Aguilar-Garduno, Clemente; Blanco-Munoz, Julia; Perez-Mendez, Oscar; Gamboa, Ricardo; Bassol, Susana; Cebrian, Mariano E.

    2010-02-15

    The ability of organophosphate pesticides to disturb thyroid gland function has been demonstrated by experimental studies on animal, but evidence of such effects on human remains scarce. The aim of this study was to assess the association between exposure to organophosphate compounds and serum levels of thyroid hormones in floriculture workers. A longitudinal study was conducted on 136 male subjects from the State of Mexico and Morelos, Mexico, occupationally exposed to organophosphate pesticides, during agricultural periods of high (rainy season) and low (dry season) levels of pesticide application. Using a structured questionnaire, a survey was carried out on sociodemographic characteristics, anthropometry, clinical history, alcohol and tobacco consumption, residential chemical exposure, and occupational history. Urine and blood samples were taken the day after pesticide application to determine urine dialkylphosphate (DAP) levels, serum levels of TSH, total T{sub 3}, total T{sub 4}, serum PON1 activity, and serum p,p'-DEE levels. The analysis of the association between DAP levels and thyroid hormonal profile was carried out using multivariate generalized estimating equation (GEE) models. Our results showed an increase in both TSH and T{sub 4} hormones in serum associated with a increase in total dimethylphosphate levels (SIGMADMP) in urine (p-trend < 0.001) and a decrease in total T{sub 3} serum levels with an increase of SIGMADMP levels in the urine (p-trend = 0.053). These results suggest that exposure to organophosphate pesticides may be responsible of increasing TSH and T{sub 4} serum hormone levels and decreasing T{sub 3} serum hormone levels, therefore supporting the hypothesis that organophosphate pesticides act as endocrine disruptors in humans.

  16. Association between organophosphate pesticides exposure and thyroid hormones in floriculture workers.

    PubMed

    Lacasaña, Marina; López-Flores, Inmaculada; Rodríguez-Barranco, Miguel; Aguilar-Garduño, Clemente; Blanco-Muñoz, Julia; Pérez-Méndez, Oscar; Gamboa, Ricardo; Bassol, Susana; Cebrian, Mariano E

    2010-02-15

    The ability of organophosphate pesticides to disturb thyroid gland function has been demonstrated by experimental studies on animal, but evidence of such effects on human remains scarce. The aim of this study was to assess the association between exposure to organophosphate compounds and serum levels of thyroid hormones in floriculture workers. A longitudinal study was conducted on 136 male subjects from the State of Mexico and Morelos, Mexico, occupationally exposed to organophosphate pesticides, during agricultural periods of high (rainy season) and low (dry season) levels of pesticide application. Using a structured questionnaire, a survey was carried out on sociodemographic characteristics, anthropometry, clinical history, alcohol and tobacco consumption, residential chemical exposure, and occupational history. Urine and blood samples were taken the day after pesticide application to determine urine dialkylphosphate (DAP) levels, serum levels of TSH, total T(3), total T(4), serum PON1 activity, and serum p,p'-DEE levels. The analysis of the association between DAP levels and thyroid hormonal profile was carried out using multivariate generalized estimating equation (GEE) models. Our results showed an increase in both TSH and T(4) hormones in serum associated with a increase in total dimethylphosphate levels (SigmaDMP) in urine (p-trend<0.001) and a decrease in total T(3) serum levels with an increase of SigmaDMP levels in the urine (p-trend=0.053). These results suggest that exposure to organophosphate pesticides may be responsible of increasing TSH and T(4) serum hormone levels and decreasing T(3) serum hormone levels, therefore supporting the hypothesis that organophosphate pesticides act as endocrine disruptors in humans.

  17. Intranasal delivery of obidoxime to the brain prevents mortality and CNS damage from organophosphate poisoning.

    PubMed

    Krishnan, Jishnu K S; Arun, Peethambaran; Appu, Abhilash P; Vijayakumar, Nivetha; Figueiredo, Taíza H; Braga, Maria F M; Baskota, Sudikshya; Olsen, Cara H; Farkas, Natalia; Dagata, John; Frey, William H; Moffett, John R; Namboodiri, Aryan M A

    2016-03-01

    Intranasal delivery is an emerging method for bypassing the blood brain barrier (BBB) and targeting therapeutics to the CNS. Oximes are used to counteract the effects of organophosphate poisoning, but they do not readily cross the BBB. Therefore, they cannot effectively counteract the central neuropathologies caused by cholinergic over-activation when administered peripherally. For these reasons we examined intranasal administration of oximes in an animal model of severe organophosphate poisoning to determine their effectiveness in reducing mortality and seizure-induced neuronal degeneration. Using the paraoxon model of organophosphate poisoning, we administered the standard treatment (intramuscular pralidoxime plus atropine sulphate) to all animals and then compared the effectiveness of intranasal application of obidoxime (OBD) to saline in the control groups. Intranasally administered OBD was effective in partially reducing paraoxon-induced acetylcholinesterase inhibition in the brain and substantially reduced seizure severity and duration. Further, intranasal OBD completely prevented mortality, which was 41% in the animals given standard treatment plus intranasal saline. Fluoro-Jade-B staining revealed extensive neuronal degeneration in the surviving saline-treated animals 24h after paraoxon administration, whereas no detectable degenerating neurons were observed in any of the animals given intranasal OBD 30min before or 5min after paraoxon administration. These findings demonstrate that intranasally administered oximes bypass the BBB more effectively than those administered peripherally and provide an effective method for protecting the brain from organophosphates. The addition of intranasally administered oximes to the current treatment regimen for organophosphate poisoning would improve efficacy, reducing both brain damage and mortality. PMID:26751814

  18. Addiction Risk Low for Seniors Taking Post-Op Opioids

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_160358.html Addiction Risk Low for Seniors Taking Post-Op Opioids: ... many worry that post-surgical use might trigger addiction. But a new study suggests that painkiller abuse ...

  19. DEVELOPMENT, VALIDATION AND FIELD USE OF NOVEL METHOD FOR EXTRACTING AND ANALYZING ORGANOPHOSPHATE (OP) AND PYRETHROID PESTICIDE METABOLITES AND CREATININE FROM COMMERCIALLY AVAILABLE DISPOSABLE DIAPERS

    EPA Science Inventory

    The ability to efficiently extract urine from disposable diapers ensures an easy to use urine collection protocol and ready compliance for caregivers of very young children. The use of disposable diapers is also desirable because of their high capacity- urine is retained effecti...

  20. Dorothy Jorgensen - Co-Op Tour Summary

    NASA Technical Reports Server (NTRS)

    Jorgensen, Dorothy

    2014-01-01

    NASA is a household name in this day and age, known commonly as America's government-run powerhouse of innovation and space exploration. It is a common dream for students to be a part of NASA's workforce, but I did not realize that it was my dream until I found that I could not imagine working anywhere else. From August to December, I had the privilege of a co-op tour with NASA at the Johnson Space Center. The National Aeronautics and Space Administration (NASA) first formed in the early hysteria of the Cold War, and in its early days it received enormous funding and political support. It was America's response to the Russian Sputnik, which was a not only a stark symbol of what was suddenly possible, but also of how far behind the United States had fallen in the race for technology. The political atmosphere in the world has since changed, but NASA's drive to push the boundaries of the impossible has not faded: NASA's primary mission has been exploration for the betterment of mankind, and it works towards that mission to this day. The specific NASA site that I worked in was by a coast near Houston, TX, at the Johnson Space Center (Figure 1). I was led on my first day of work to a building dedicated to Structural Engineering (Building 13), which was where I would be spending most of my time in the months to come. It was here that I had my desk and cubicle, and would later do the bulk of my computer modeling and theoretical planning. Later that day we traveled to the Vibrations and Acoustics Test Facility (Building 49), and here I was shown the parts we would use for our technical project and the locations we would work in. I worked in the Loads and Dynamics Branch of the Structural Engineering Division, in the Engineering Directorate.

  1. Long-term time series prediction using OP-ELM.

    PubMed

    Grigorievskiy, Alexander; Miche, Yoan; Ventelä, Anne-Mari; Séverin, Eric; Lendasse, Amaury

    2014-03-01

    In this paper, an Optimally Pruned Extreme Learning Machine (OP-ELM) is applied to the problem of long-term time series prediction. Three known strategies for the long-term time series prediction i.e. Recursive, Direct and DirRec are considered in combination with OP-ELM and compared with a baseline linear least squares model and Least-Squares Support Vector Machines (LS-SVM). Among these three strategies DirRec is the most time consuming and its usage with nonlinear models like LS-SVM, where several hyperparameters need to be adjusted, leads to relatively heavy computations. It is shown that OP-ELM, being also a nonlinear model, allows reasonable computational time for the DirRec strategy. In all our experiments, except one, OP-ELM with DirRec strategy outperforms the linear model with any strategy. In contrast to the proposed algorithm, LS-SVM behaves unstably without variable selection. It is also shown that there is no superior strategy for OP-ELM: any of three can be the best. In addition, the prediction accuracy of an ensemble of OP-ELM is studied and it is shown that averaging predictions of the ensemble can improve the accuracy (Mean Square Error) dramatically.

  2. Long-term time series prediction using OP-ELM.

    PubMed

    Grigorievskiy, Alexander; Miche, Yoan; Ventelä, Anne-Mari; Séverin, Eric; Lendasse, Amaury

    2014-03-01

    In this paper, an Optimally Pruned Extreme Learning Machine (OP-ELM) is applied to the problem of long-term time series prediction. Three known strategies for the long-term time series prediction i.e. Recursive, Direct and DirRec are considered in combination with OP-ELM and compared with a baseline linear least squares model and Least-Squares Support Vector Machines (LS-SVM). Among these three strategies DirRec is the most time consuming and its usage with nonlinear models like LS-SVM, where several hyperparameters need to be adjusted, leads to relatively heavy computations. It is shown that OP-ELM, being also a nonlinear model, allows reasonable computational time for the DirRec strategy. In all our experiments, except one, OP-ELM with DirRec strategy outperforms the linear model with any strategy. In contrast to the proposed algorithm, LS-SVM behaves unstably without variable selection. It is also shown that there is no superior strategy for OP-ELM: any of three can be the best. In addition, the prediction accuracy of an ensemble of OP-ELM is studied and it is shown that averaging predictions of the ensemble can improve the accuracy (Mean Square Error) dramatically. PMID:24365536

  3. Quantitative trait locus mapping and functional genomics of an organophosphate resistance trait in the western corn rootworm, Diabrotica virgifera virgifera

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The western corn rootworm (WCR), Diabrotica virgifera virgifera, is an insect pest of corn, and population suppression with chemical insecticides is an important management tool. Traits conferring organophosphate insecticide resistance have increased in frequency among WCR populations, resulting in...

  4. A case report of motor neuron disease in a patient showing significant level of DDTs, HCHs and organophosphate metabolites in hair as well as levels of hexane and toluene in blood

    SciTech Connect

    Kanavouras, Konstantinos; Tzatzarakis, Manolis N.; Mastorodemos, Vasileios; Plaitakis, Andreas; Tsatsakis, Aristidis M.

    2011-11-15

    Motor neuron disease is a devastating neurodegenerative condition, with the majority of sporadic, non-familial cases being of unknown etiology. Several epidemiological studies have suggested that occupational exposure to chemicals may be associated with disease pathogenesis. We report the case of a patient developing progressive motor neuron disease, who was chronically exposed to pesticides and organic solvents. The patient presented with leg spasticity and developed gradually clinical signs suggestive of amyotrophic lateral sclerosis, which was supported by the neurophysiologic and radiological findings. Our report is an evidence based case of combined exposure to organochlorine (DDTs), organophosphate pesticides (OPs) and organic solvents as confirmed by laboratory analysis in samples of blood and hair confirming systematic exposure. The concentration of non-specific dialkylphosphates metabolites (DAPs) of OPs in hair (dimethyphopshate (DMP) 1289.4 pg/mg and diethylphosphate (DEP) 709.4 pg/mg) and of DDTs (opDDE 484.0 pg/mg, ppDDE 526.6 pg/mg, opDDD 448.4 pg/mg, ppDDD + opDDT 259.9 pg/mg and ppDDT 573.7 pg/mg) were considerably significant. Toluene and n-hexane were also detected in blood on admission at hospital and quantified (1.23 and 0.87 {mu}g/l, respectively), while 3 months after hospitalization blood testing was found negative for toluene and n-hexane and hair analysis was provided decrease levels of HCHs, DDTs and DAPs. -- Highlights: Black-Right-Pointing-Pointer Exposure to pesticides and organic solvents might be a risk factor for sporadic MND. Black-Right-Pointing-Pointer We report a patient who developed progressive upper and lower motor neuron disease. Black-Right-Pointing-Pointer The patient had a history of occupational exposure to pesticides and solvents. Black-Right-Pointing-Pointer High DDTs' levels and increased levels of DMP and DEP were measured in his hair. Black-Right-Pointing-Pointer The patients' exposure to chemicals might have played

  5. Role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to organophosphate pesticides

    SciTech Connect

    Singh, Satyender; Kumar, Vivek; Vashisht, Kapil; Singh, Priyanka; Banerjee, Basu Dev; Rautela, Rajender Singh; Grover, Shyam Sunder; Rawat, Devendra Singh; Pasha, Syed Tazeen; Jain, Sudhir Kumar; Rai, Arvind

    2011-11-15

    Organophosphate pesticides (OPs) are primarily metabolized by several xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticide-exposed workers. The present study was designed to determine the role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to OPs. We examined 284 subjects including 150 workers occupationally exposed to OPs and 134 normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using PCR-RFLP. The results revealed that the PONase activity toward paraoxonase and AChE activity was found significantly lowered in workers as compared to control subjects (p < 0.001). Workers showed significantly higher DNA damage compared to control subjects (14.37 {+-} 2.15 vs. 6.24 {+-} 1.37 tail% DNA, p < 0.001). Further, the workers with CYP2D6*3 PM and PON1 (QQ and MM) genotypes were found to have significantly higher DNA damage when compared to other genotypes (p < 0.05). In addition, significant increase in DNA damage was also observed in workers with concomitant presence of certain CYP2D6 and PON1 (Q192R and L55M) genotypes which need further extensive studies. In conclusion, the results indicate that the PON1 and CYP2D6 genotypes can modulate DNA damage elicited by some OPs possibly through gene-environment interactions. -- Highlights: Black-Right-Pointing-Pointer Role of CYP1A1, CYP3A5, CYP2C, CYP2D6 and PON1 genotypes on DNA damage. Black-Right-Pointing-Pointer Workers exposed to some OPs demonstrated increased DNA damage. Black-Right-Pointing-Pointer CYP2D6 *3 PM and PON1 (Q192R and L55M) genotypes are associated with DNA damage. Black-Right-Pointing-Pointer Concomitant presence of certain CYP2D6 and PON1 genotypes can increase DNA damage.

  6. Fluorescence Spectroscopy Approaches for the Development of a Real-Time Organophosphate Detection System Using an Enzymatic Sensor

    PubMed Central

    Carullo, Paola; Cetrangolo, Giovanni Paolo; Mandrich, Luigi; Manco, Giuseppe; Febbraio, Ferdinando

    2015-01-01

    Organophosphates are organic substances that contain a phosphoryl or a thiophosphoryl bond. They are mainly used around the world as pesticides, but can also be used as chemical warfare agents. Their detection is normally entrusted to techniques like GC- and LC-MS that, although sensitive, do not allow their identification on site and in real time. We have approached their identification by exploiting the high-affinity binding of these compounds with the esterase 2 from Alicyclobacillus acidocaldarius. Using an in silico analysis to evaluate the binding affinities of the enzyme with organophosphate inhibitors, like paraoxon, and other organophosphate compounds, like parathion, chlorpyriphos, and other organophosphate thio-derivatives, we have designed fluorescence spectroscopy experiments to study the quenching of the tryptophan residues after esterase 2 binding with the organophosphate pesticides. The changes in the fluorescence signals permitted an immediate and quantitative identification of these compounds from nano- to picomolar concentrations. A fluorescence based polarity-sensitive probe (ANS) was also employed as a means to understand the extent of the interactions involved, as well as to explore other ways to detect organophosphate pesticides. Finally, we designed a framework for the development of a biosensor that exploits fluorescence technology in combination with a sensitive and very stable bio-receptor. PMID:25671511

  7. An Observational Study to Evaluate Associations Between Low-Level Gestational Exposure to Organophosphate Pesticides and Cognition During Early Childhood.

    PubMed

    Donauer, Stephanie; Altaye, Mekibib; Xu, Yingying; Sucharew, Heidi; Succop, Paul; Calafat, Antonia M; Khoury, Jane C; Lanphear, Bruce; Yolton, Kimberly

    2016-09-01

    Prenatal exposure to organophosphate pesticides, which is ubiquitous, may be detrimental to neurological development. We examined 327 mother/infant pairs in Cincinnati, Ohio, between 2003 and 2006 to determine associations between prenatal exposure to organophosphate pesticides and neurodevelopment. Twice during pregnancy urinary concentrations of 6 common dialkylphosphates, nonspecific metabolites of organophosphate pesticides, were measured. Aggregate concentrations of diethylphosphates, dimethylphosphates, and total dialkylphosphates were calculated. Bayley Scales of Infant Development, Second Edition-Mental and Psychomotor Developmental indices were administered at ages 1, 2, and 3 years, the Clinical Evaluation of Language Fundamentals-Preschool, Second Edition, at age 4, and the Wechsler Preschool and Primary Scale of Intelligence, Third Edition, at age 5. Mothers with higher urinary total dialkylphosphate concentrations reported higher levels of socioeconomic status and increased fresh fruit and vegetable intake. We found no associations between prenatal exposure to organophosphate pesticides and cognition at 1-5 years of age. In our cohort, exposure to organophosphate pesticides during pregnancy was not associated with cognition during early childhood. It is possible that a higher socioeconomic status and healthier diet may protect the fetus from potential adverse associations with gestational organophosphate pesticide exposure, or that dietary exposure to the metabolites is innocuous and not an ideal measure of exposure to the parent compound. PMID:27539379

  8. GABA and Dopamine Release from Different Brain Regions in Mice with Chronic Exposure to Organophosphate Methamidophos

    PubMed Central

    Noriega-Ortega, Blanca Rosa; Armienta-Aldana, Ernesto; Cervantes-Pompa, José Ángel; Armienta-Aldana, Eduardo; Hernández-Ruíz, Enrique; Chaparro-Huerta, Verónica; Bravo-Cuellar, Alejandro; Beas-Zárate, Carlos

    2011-01-01

    Organophosphates such as methamidophos, usually used in the agricultural field, have harmful effects on humans. Exposures to insecticides has been associated with many disorders, including damage to the central and peripheral nervous system. Chronic exposure to organophosphates may lead to persistent neurological and neurobehavioral effects. This study was conducted to determine the effect of methamidophos on [3H]-dopamine (DA) and gamma aminobutyric acid (GABA) release from different brain regions after chronic exposure to it for 3, 6 or 9 months. After a six-month methamidophos treatment, the mice showed high susceptibility to convulsive seizures and a reduction in stimulated gamma aminobutyric acid release from the cerebral cortex and hippocampal slices, whereas stimulated (DA) release was slightly decreased from the striatum after three months of methamidophos exposure. The results indicate changes in gamma aminobutyric acid and dopamine neurotransmission, suggesting a specific neuronal damage. PMID:22272056

  9. Microplate assay analysis of the distribution of organophosphate and carbamate resistance in Guatemalan Anopheles albimanus

    PubMed Central

    Brogdon, W. G.; Beach, R. F.; Stewart, J. M.; Castanaza, L.

    1988-01-01

    Simple microplate assay methods for determining the frequency of insecticide resistance in single mosquitos were used to study the distribution and localization of organophosphate and carbamate resistance in field populations of Anopheles albimanus Weidemann in Guatemala, where such resistance, caused by heavy use of agricultural pesticides, has long been assumed to be widespread. Areas of complete susceptibility to organophosphates and carbamates were observed, as well as areas where the resistant phenotypes represented up to 98% of the population. Overall, the resistance levels were lower and more localized than expected. Two mechanisms of resistance were identified by the microassay methods. These were the elevated esterase (nonspecific esterase) and insensitive acetylcholinesterase mechanisms which were selected independently, the former (documented for the first time in Central American anophelines) being predominant. These methods represent a promising new technology for the detection and assessment of resistance and will facilitate improved control strategy decisions. PMID:3262440

  10. Organophosphate pesticide exposure and neurobehavioral performance in agricultural and non-agricultural Hispanic workers.

    PubMed

    Rothlein, Joan; Rohlman, Diane; Lasarev, Michael; Phillips, Jackie; Muniz, Juan; McCauley, Linda

    2006-05-01

    Our understanding of the health risks of farmworkers exposed to pesticides in their work and home environments is rapidly increasing, although studies designed to examine the possible neurobehavioral effects of low-level chronic pesticide exposure are limited. We measured dialkyl phosphate urinary metabolite levels, collected environmental dust samples from a subset of homes, obtained information on work practices, and conducted neurobehavioral tests on a sample of farmworkers in Oregon. Significant correlations between urinary methyl metabolite levels and total methyl organophosphate (azinphos-methyl, phosmet, malathion) house dust levels were observed. We found the neurobehavioral performance of Hispanic immigrant farmworkers to be lower than that observed in a nonagricultural Hispanic immigrant population, and within the sample of agricultural workers there was a positive correlation between urinary organophosphate metabolite levels and poorer performance on some neurobehavioral tests. These findings add to an increasing body of evidence of the association between low levels of pesticide exposure and deficits in neurobehavioral performance. PMID:16675422

  11. Distribution of organophosphate and carbamate resistance in Culex pipiens quinquefasciatus (Diptera: Culicidae) in West Africa.

    PubMed

    Chandre, F; Darriet, F; Doannio, J M; Rivière, F; Pasteur, N; Guillet, P

    1997-11-01

    The distribution of organophosphate and carbamate resistance was investigated in 33 samples of Culex pipiens quinquefasciatus Say from 25 cities in Côte d'Ivoire and Burkina Faso. Organophosphate resistance levels were higher in Côte d'Ivoire than in Burkina Faso. Chlorpyrifos resistance ratios at LC95 ranged from 4 to 30 times in Côte d'Ivoire and from 3 to 6 times in Burkina Faso. For temephos, ratios ranged from 3 to 18 and from 1 to 2, respectively. Of 27 samples from Côte d'Ivoire, 25 also displayed cross resistance to carbamates as shown by a mortality plateau in bioassays with propoxur and carbosulfan (similar to chlorpyrifos). Cross resistance to organophosphates and carbamates was caused by an insensitive acetylcholinesterase allele (AceR). This gene was absent from Burkina Faso, except in Niangoloko near the Côte d'Ivoire border. Organophosphate resistance also was associated with the presence of A2-B2 overproduced esterases which had higher frequencies in Côte d'Ivoire (75-100%) than in Burkina Faso (40-50%). Two other esterases with the same electrophoretic mobility as C2 from Puerto Rico and B1 from California were identified for the 1st time in West Africa. "C2" was widespread, whereas "B1" was present in only a few mosquitoes from Côte d'Ivoire. These differences in resistance patterns should be taken into consideration in planning urban mosquito control strategies within 2 countries.

  12. Interaction between organophosphate pesticide exposure and PON1 activity on thyroid function

    SciTech Connect

    Lacasana, Marina; Lopez-Flores, Inmaculada; Rodriguez-Barranco, Miguel; Aguilar-Garduno, Clemente; Blanco-Munoz, Julia; Perez-Mendez, Oscar; Gamboa, Ricardo; Gonzalez-Alzaga, Beatriz; Bassol, Susana; Cebrian, Mariano E.

    2010-11-15

    Organophosphate pesticides are widely used in agricultural purposes. Recently, a few studies have demonstrated the ability of these chemicals to alter the function of the thyroid gland in human. Moreover, the paraoxonase-1 enzyme (PON1) plays an important role in the toxicity of some organophosphate pesticides, with low PON1 activity being associated with higher pesticide sensitivity. This study evaluates the interaction between exposure to organophosphate compounds and PON1 enzyme activity on serum levels of TSH and thyroid hormones in a population of workers occupationally exposed to pesticides. A longitudinal study was conducted on a population of floriculture workers from Mexico, during two periods of high and low-intensity levels of pesticide application. A structured questionnaire was completed by workers containing questions on sociodemographic characteristics and other variables of interest. Urine and blood samples were taken, and biomarkers of exposure (dialkylphosphates), susceptibility (PON1 polymorphisms and activity) and effect (thyroid hormone levels) were determined. Interaction between dialkylphosphates and PON1 polymorphisms or PON1 activity on hormone levels was evaluated by generalized estimating equation (GEE) models. A significant interaction was found between serum diazoxonase activity and total dialkylphosphates ({Sigma}DAP) on TSH levels. Thus, when PON1 activity was increased we observed a decrease in the percentage of variation of TSH level for each increment in one logarithmic unit of the {Sigma}DAP levels. This interaction was also observed with the PON1{sub 192}RR genotype. These results suggest a stronger association between organophosphate pesticides and thyroid function in individuals with lower PON1 activity.

  13. Levels of metabolites of organophosphate pesticides, phthalates, and bisphenol A in pooled urine specimens from pregnant women participating in the Norwegian Mother and Child Cohort Study (MoBa).

    PubMed

    Ye, Xibiao; Pierik, Frank H; Angerer, Jürgen; Meltzer, Helle Margrete; Jaddoe, Vincent W V; Tiemeier, Henning; Hoppin, Jane A; Longnecker, Matthew P

    2009-09-01

    Concerns about reproductive and developmental health risks of exposure to organophosphate (OP) pesticides, phthalates, and bisphenol A (BPA) among the general population are increasing. Six dialkyl phosphate (DAP) metabolites, 3,5,6-trichloro-2-pyridinol (TCPy), BPA, and fourteen phthalate metabolites were measured in 10 pooled urine samples representing 110 pregnant women who participated in the Norwegian Mother and Child Birth Cohort (MoBa) study in 2004. Daily intakes were estimated from urinary data and compared with reference doses (RfDs) and daily tolerable intakes (TDIs). The MoBa women had a higher mean BPA concentration (4.50 microg/L) than the pregnant women in the Generation R Study (Generation R) in the Netherlands and the National Health and Nutrition Examination Survey (NHANES) in the United States. The mean concentration of total DAP metabolites (24.20 microg/L) in MoBa women was higher than that in NHANES women but lower than that in Generation R women. The diethyl phthalate metabolite mono-ethyl phthalate (MEP) was the dominant phthalate metabolite in all three studies, with the mean concentrations of greater than 300 microg/L. The MoBa and Generation R women had higher mean concentrations of mono-n-butyl phthalate (MnBP) and mono-isobutyl phthalate (MiBP) than the NHANES women. The estimated average daily intakes of BPA, chlorpyrifos/chlorpyrifos-methyl and phthalates in MoBa (and the other two studies) were below the RfDs and TDIs. The higher levels of metabolites in the MoBa participants may have been from intake via pesticide residues in food (organophosphates), consumption of canned food, especially fish/seafood (BPA), and use of personal care products (selected phthalates).

  14. Oxygen-organophosphate linkage in hemoglobin A. The double hump effect.

    PubMed Central

    Kister, J; Poyart, C; Edelstein, S J

    1987-01-01

    At low concentrations of chloride ions, and in the presence of nonsaturating concentrations of organophosphates, the oxygen equilibrium curves (OEC) for solutions of human adult hemoglobin exhibit a biphasic shape conveniently revealed by graphical analysis of the first derivative of the Hill equation with a characteristic form that we call "the double hump effect." This shape, observed for sub-saturating concentrations of organophosphates, stands in marked contrast to the simple lateral shifts of the OEC represented largely by scaling factors when pH or chloride are varied. In the case of protons or chloride, there is a self-buffering effect due to the presence of a large reservoir of proton or chloride binding sites not necessarily linked to oxygen, whereas such sites do not exist in the case of organophosphates. In addition, in the former case, we are dealing with curves measured at constant activity of the effector, while in the latter, at constant concentration. In the presence of saturating concentrations of inositol hexaphosphate (IHP), at low chloride concentration, the entire OEC is shifted to the right, including both its upper and lower asymptotes, indicating a decrease in the intrinsic oxygen affinities of both the T and R states. Theoretical considerations leading to a successful modeling of OEC obtained under nonsaturating and saturating concentrations of IHP required an expanded two-state allosteric model in which IHP-dependent variations in oxygen association constants for both the T and R conformations are taken into account. PMID:3676434

  15. New Onset Refractory Status Epilepticus as an Unusual Presentation of a Suspected Organophosphate Poisoning

    PubMed Central

    Waheed, Shahan; Sabeen, Amber; Ullah Khan, Nadeem

    2014-01-01

    New onset refractory status epilepticus (NORSE) is a new entity in medical literature. It has different infectious and noninfectious etiologies showing a devastating impact onto the clinical outcome of patients. Therapy with anaesthetic and antiepileptic agents often fails to improve the condition, unless the primary cause is rectified. Here is presented the case of a young female with a history of depression who after a recent bereavement came to the Emergency Department of Aga Khan University Hospital with complaints of drowsiness that lasted for few hours. Though she had no history of organophosphate poisoning, her physical examination and further investigations were suggestive of the diagnosis. During her hospital stay, she developed refractory status epilepticus. Her seizures did not respond to standard antiepileptic and intravenous anesthetic agents and subsided only after intravenous infusion of atropine for a few days. Organophosphate poisoning is a very common presentation in the developing world and the associated status epilepticus poses a devastating problem for emergency physicians. In patients with suspected organophosphate poisoning with favoring clinical exam findings, the continuation of atropine intravenous infusion can be a safe option to abate seizures. PMID:25580311

  16. Carbon Dioxide Observational Platform System (CO-OPS), feasibility study

    NASA Technical Reports Server (NTRS)

    Bouquet, D. L.; Hall, D. W.; Mcelveen, R. P.

    1987-01-01

    The Carbon Dioxide Observational Platform System (CO-OPS) is a near-space, geostationary, multi-user, unmanned microwave powered monitoring platform system. This systems engineering feasibility study addressed identified existing requirements such as: carbon dioxide observational data requirements, communications requirements, and eye-in-the-sky requirements of other groups like the Defense Department, the Forestry Service, and the Coast Guard. In addition, potential applications in: earth system science, space system sciences, and test and verification (satellite sensors and data management techniques) were considered. The eleven month effort is summarized. Past work and methods of gathering the required observational data were assessed and rough-order-of magnitude cost estimates have shown the CO-OPS system to be most cost effective (less than $30 million within a 10 year lifetime). It was also concluded that there are no technical, schedule, or obstacles that would prevent achieving the objectives of the total 5-year CO-OPS program.

  17. Exposure of male mice to two kinds of organophosphate flame retardants (OPFRs) induced oxidative stress and endocrine disruption.

    PubMed

    Chen, Guanliang; Jin, Yuanxiang; Wu, Yan; Liu, Ling; Fu, Zhengwei

    2015-07-01

    Triphenyl phosphate (TPP) and tris(2-chloroethyl) phosphate (TCEP) are two of the most common organophosphate flame retardants in the ecosystem. Effects of TPP and TCEP on the induction of oxidative stress and endocrine disruption were evaluated in five weeks old male mice. After receiving 100, 300 mg/kg/bodyweight oral exposure to TPP and TCEP for 35 days, the body and testis weights decreased in 300 mg/kg TPP and TCEP treated groups. Hepatic malondialdehyde (MDA) contents increased significantly in both TPP treated groups, while the contents of glutathione (GSH) decreased significantly in 300 mg/kg TPP and both TCEP treated groups. In addition, the hepatic activities of antioxidant enzymes including glutathione peroxidase (GPX), catalase (CAT) and glutathione S-transferase (GST) as well as their related gene expression were affected by TPP or TECP exposure. On the other hand, 300 mg/kg of TPP or TECP treatment resulted in histopathological damage and the decrease of testicular testosterone levels. Moreover, the expression of main genes related to testosterone synthesis including steroidogenic acute regulatory protein (StAR), low-density lipoprotein receptor (LDL-R), cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc) and cytochrome P450 17α-hydroxysteroid dehydrogenase (P450-17α) in the testes also decreased after the exposure to 300 mg/kg TPP or TCEP for 35 days. Combined with the effects on physiology, histopathology and the expression of genes, TPP and TCEP can induce oxidative stress and endocrine disruption in mice.

  18. Population-Based Biomonitoring of Exposure to Organophosphate and Pyrethroid Pesticides in New York City

    PubMed Central

    Jacobson, J. Bryan; Kass, Daniel; Barr, Dana Boyd; Davis, Mark; Calafat, Antonia M.; Aldous, Kenneth M.

    2013-01-01

    Background: Organophosphates and pyrethroids are the most common classes of insecticides used in the United States. Widespread use of these compounds to control building infestations in New York City (NYC) may have caused higher exposure than in less-urban settings. Objectives: The objectives of our study were to estimate pesticide exposure reference values for NYC and identify demographic and behavioral characteristics that predict exposures. Methods: The NYC Health and Nutrition Examination Survey was a population-based, cross-sectional study conducted in 2004 among adults ≥ 20 years of age. It measured urinary concentrations of organophosphate metabolites [dimethylphosphate (DMP), dimethylthiophosphate (DMTP), dimethyldithiophosphate, diethylphosphate, diethylthiophosphate, and diethyldithiophosphate] in 883 participants, and pyrethroid metabolites [3-phenoxybenzoic acid (3-PBA), trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (trans-DCCA), 4-fluoro-3-phenoxybenzoic acid, and cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid] in 1,452 participants. We used multivariable linear regression to estimate least-squares geometric mean total dialkylphospate (ΣDAP) and 3-PBA concentrations across categories of predictors. Results: The dimethyl organophosphate metabolites had the highest 95th percentile concentrations (87.4 μg/L and 74.7 μg/L for DMP and DMTP, respectively). The highest 95th percentiles among pyrethroid metabolites were measured for 3-PBA and trans-DCCA (5.23 μg/L and 5.94 μg/L, respectively). Concentrations of ΣDAP increased with increasing age, non-Hispanic white or black compared with Hispanic race/ethnicity, professional pesticide use, and increasing frequency of fruit consumption; they decreased with non-green vegetable consumption. Absolute differences in geometric mean urinary 3-PBA concentrations across categories of predictors were too small to be meaningful. Conclusion: Estimates of exposure to

  19. Analysis of 1,000 consecutive cases of acute poisoning in the suburb of Tokyo leading to hospitalization.

    PubMed

    Yamashita, M; Matsuo, H; Tanaka, J; Yamashita, M

    1996-02-01

    We have analyzed retrospectively 1,000 consecutive admissions due to acute poisonings over 13 years. Total mortality was 27%. Acute poisonings due to pesticides, therapeutic drugs and other substances were 518, 332 and 150 cases with mortalities of 51, 1 and 5%, respectively. The most frequent cause of acute poisoning was paraquat/diquat products, whose mortality reached 76% (220 deaths/291 cases). The second most frequent cause was organophosphate/carbamate products with a mortality of 24% (37/155). When these 2 pesticides are excluded, the mortality was only 3% (15/554). To reduce instances of paraquat/diquat poisoning, dilution of the available product or formulation in other than liquid form would be desirable, because no effective treatment is currently available. In cases of organophosphate/carbamate poisoning, early hospitalization and stabilization is crucial.

  20. Crossing Boundaries: Co-Op Students Relearning to Write

    ERIC Educational Resources Information Center

    Brent, Doug

    2012-01-01

    This article reviews the deeply conflicted literature on learning transfer, especially as it applies to rhetorical knowledge and skill. It then describes a study in which six students are followed through their first co-op work term to learn about which resources they draw on as they enter a new environment of professional writing. It suggests…

  1. Co-op Education in the Canadian Curriculum.

    ERIC Educational Resources Information Center

    Munby, Hugh; Hutchinson, Nancy; Chin, Peter

    2000-01-01

    Research on co-op education in Canadian secondary schools indicates that it was under-appreciated in ministry policy. However, participants felt that cooperative education was a career exploration opportunity, contextualized the academic curriculum, taught work ethics, and prepared students for postsecondary programs. A clearer commitment to…

  2. Engaging the public through writing an op-ed

    NASA Astrophysics Data System (ADS)

    Labosier, Chris; Zhu, Laiyin; Quiring, Steven

    2012-10-01

    In May, prior to the start of the 2012 hurricane season, AGU asked us to write an op-ed for the Houston Chronicle on the importance of funding hurricane research. We were excited to be asked and pleased that AGU facilitated the process by providing us with some guidance on writing the op-ed. Given the impact that Hurricane Ike had in Texas just a few years ago, we felt it was important to remind the citizens of the greater Houston metropolitan area of the societal benefits of funding hurricane research. Thanks to the assistance of AGU staff, writing the article required only a few hours of time. Our op-ed was published in the print edition of the Houston Chronicle on 1 June 2012, the official start of the hurricane season (http://www.chron.com/default/article/Tight-budgets-posing-threat-to-Texas-hurricane-3600363.php). It was picked up by the media relations office in the College of Geosciences at Texas A&M University and featured on the college's Web site in the dean's biweekly briefing and on its Facebook page. As a result, the op-ed reached a large and diverse audience.

  3. Low-cost OP-FTIR spectrometer for workplace monitoring

    NASA Astrophysics Data System (ADS)

    Rentz, Julia H.; Engel, James R.; Carlson, David L.; Mansur, David J.; Vaillancourt, Robert M.; Genetti, George J.; Griffiths, Peter R.; Yang, Husheng

    2004-03-01

    OPTRA has developed a low-cost, extremely compact, rugged open-path Fourier transform infrared (OP-FTIR) spectrometer for workplace air quality monitoring. This research was funded under a United States Air Force ABIR Phase II contract. The goal of the program has been to identify and alleviate all aspects of currently available OP-FTIR systems which result in high-cost and complex user requirements. This low-resolution ssytem (Δσ = 8 cm-1) employs an uncooled DLATGS detector and a novel encoder-based reference metrology. Other design economies include a plastic injection-molded retroreflector array to return the open-path beam. This effort has included the development of a set of algorithms based on artificial neural networks (ANNs) and partial least squares (PLS) by the University of Idaho; these algorithms are specifically tailored to low-resolution systems applied to multi-component analysis of large, organic molecules characterized by broad infrared resonance bands. The algorithms, coupled with our OP-FTIR, are designed to autonomously identify and quantify a list of 105 common industrial organic molecules in the presence of varying humidity levels. Our system includes two PCI boards which host all OP-FTIR processing and servo electronics; the boards reside in a small suit-case PC along with a user-friendly Graphical User Interface.

  4. Cystitis - acute

    MedlinePlus

    Uncomplicated urinary tract infection; UTI - acute; Acute bladder infection; Acute bacterial cystitis ... International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: A 2010 ...

  5. Does the Op-Ed Page Have a Chance to Become a Public Forum?

    ERIC Educational Resources Information Center

    Ciofalo, Andrew; Traverso, Kim

    1994-01-01

    Surveys op-ed page editors, finding that fewer than half of the responding papers have op-ed pages; that professional journalists, public figures, and propagandists dominate the pages; and that editors firmly control the agenda. (SR)

  6. Influence of organophosphate poisoning on human dendritic cells.

    PubMed

    Schäfer, Marina; Koppe, Franziska; Stenger, Bernhard; Brochhausen, Christoph; Schmidt, Annette; Steinritz, Dirk; Thiermann, Horst; Kirkpatrick, Charles James; Pohl, Christine

    2013-12-01

    Organophosphourus compounds (OPC, including nerve agents and pesticides) exhibit acute toxicity by inhibition of acetylcholinesterase. Lung affections are frequent complications and a risk factor for death. In addition, epidemiological studies reported immunological alterations after OPC exposure. In our experiments we investigated the effects of organophosphourus pesticides dimethoate and chlorpyrifos on dendritic cells (DC) that are essential for the initial immune response, especially in the pulmonary system. DC, differentiated from the monocyte cell line THP-1 by using various cytokines (IL-4, GM-CSF, TNF-α, Ionomycin), were exposed to organophosphourus compounds at different concentrations for a 24h time period. DC were characterized by flow cytometry and immunofluorescence using typical dendritic cell markers (e.g., CD11c, CD209 and CD83). After OPC exposure we investigated cell death, the secretion profile of inflammatory mediators, changes of DC morphology, and the effect on protein kinase signalling pathways. Our results revealed a successful differentiation of THP-1 into DC. OPC exposure caused a significant concentration-dependent influence on DC: Dendrites of the DC were shortened and damaged, DC-specific cell surface markers (i.e., CD83and CD209) decreased dramatically after chlorpyrifos exposure. Interestingly, the effects caused by dimethoate were in general less pronounced. The organophosphourus compounds affected the release of inflammatory cytokines, such as IL-1ß and IL-8. The anti-inflammatory cytokine IL-10 was significantly down regulated. Protein kinases like the Akt family or ERK, which are essential for cell survival and proliferation, were inhibited by both OPC. These findings indicate that the tested organophosphourus compounds induced significant changes in cell morphology, inhibited anti-inflammatory cytokines and influenced important protein signalling pathways which are involved in regulation of apoptosis. Thus our results highlight

  7. Emissions of organophosphate and brominated flame retardants from selected consumer products and building materials

    NASA Astrophysics Data System (ADS)

    Kemmlein, Sabine; Hahn, Oliver; Jann, Oliver

    The emissions of selected flame retardants were measured in 1- and 0.02-m 3 emission test chambers and 0.001-m 3 emission test cells. Four product groups were of interest: insulating materials, assembly foam, upholstery/mattresses, and electronics equipment. The experiments were performed under constant environmental conditions (23°C, 50% RH) using a fixed sample surface area and controlled air flow rates. Tris (2-chloro-isopropyl)phosphate (TCPP) was observed to be one of the most commonly emitted organophosphate flame retardants in polyurethane foam applications. Depending on the sample type, area-specific emission rates (SER a) of TCPP varied between 20 ng m -2 h -1 and 140 μg m -2 h -1. The emissions from electronic devices were measured at 60°C to simulate operating conditions. Under these conditions, unit specific emission rates (SER u) of organophosphates were determined to be 10-85 ng unit -1 h -1. Increasing the temperature increased the emission of several flame retardants by up to a factor of 500. The results presented in this paper indicate that emissions of several brominated and organophosphate flame retardants are measurable. Polybrominated diphenylethers exhibited an SER a of between 0.2 and 6.6 ng m -2 h -1 and an SER u of between 0.6 and 14.2 ng unit -1 h -1. Because of sink effects, i.e., sorption to chamber components, the emission test chambers and cells used in this study have limited utility for substances low vapour pressures, especially the highly brominated compounds; hexabromocyclododecane had an SER a of between 0.1 and 29 ng m -2 h -1 and decabromodiphenylether was not detectable at all.

  8. Characterizing biological variability in livestock blood cholinesterase activity for biomonitoring organophosphate nerve agent exposure

    SciTech Connect

    Halbrook, R.S.; Shugart, L.R.; Watson, A.P.; Munro, N.B.; Linnabary, R.D. )

    1992-09-01

    A biomonitoring protocol, using blood cholinesterase (ChE) activity in livestock as a monitor of potential organophosphate nerve agent exposure during the planned destruction of US unitary chemical warfare agent stockpiles, is described. The experimental design included analysis of blood ChE activity in individual healthy sheep, horses, and dairy and beef cattle during a 10- to 12-month period. Castrated and sexually intact males, pregnant and lactating females, and adult and immature animals were examined through at least one reproductive cycle. The same animals were used throughout the period of observation and were not exposed to ChE-inhibiting organophosphate or carbamate compounds. A framework for an effective biomonitoring protocol within a monitoring area includes establishing individual baseline blood ChE activity for a sentinel group of 6 animals on the bases of blood samples collected over a 6-month period, monthly collection of blood samples for ChE-activity determination during monitoring, and selection of adult animals as sentinels. Exposure to ChE-inhibiting compounds would be suspected when all blood ChE activity of all animals within the sentinel group are decreased greater than 20% from their own baseline value. Sentinel species selection is primarily a logistical and operational concern; however, sheep appear to be the species of choice because within-individual baseline ChE activity and among age and gender group ChE activity in sheep had the least variability, compared with data from other species. This protocol provides an effective and efficient means for detecting abnormal depressions in blood ChE activity in livestock and can serve as a valuable indicator of the extent of actual plume movement and/or deposition in the event of organophosphate nerve agent release.

  9. Organophosphate inhibition of avian salt gland Na, K-ATPase activity

    USGS Publications Warehouse

    Eastin, W.C.; Fleming, W.J.; Murray, H.C.

    1982-01-01

    1. Adult black ducks (Anas rubripes) were given freshwater or saltwater (1.5% NaCl) for 11 days and half of each group was also given an organophosphate (17 p.p.m. fenthion) in the diet on days 6-11. 2. After 11 days, ducks drinking saltwater had lost more weight and had higher plasma Na and uric acid concentrations and osmolalities than birds drinking freshwater. 3. Saltwater treatment stimulated the salt gland to increased weight and Na, K-ATPase activity. 4. Fenthion generally reduced plasma and brain cholinesterase activity and depressed cholinesterase and Na, K-ATPase activities in salt glands of birds drinking saltwater.

  10. [Pharmacological tolerance to medical therapy of organophosphate poisoning and ways of tolerance management].

    PubMed

    Iudin, M A; Bykov, V N; Chepur, S V; Sarana, A M; Tsygan, V N; Anokhin, A G

    2014-05-01

    Authors consider causes of low efficiency of antidote therapy and ways of pharmacological tolerance management during medical treatment of organophosphate poisoning. One of the promising ways is a preventive antidote on the base of enzyme agents and allosteric modulators of a cholinesterase activity. Authors showed a expediency of a study of new acetylcholinesterase reactivators, its compositions and ways of drug delivery. Authors specified ways of searching for anticonvulsants from classes of quick-closing benzodiatines and NMDA-antagonists. Authors defined ways of improvement of methods of special antidotes delivery with targeted transport system. Authors made an assumption about the necessity of symptomatic treatment.

  11. Microbial Community Responses to Organophosphate Substrate Additions in Contaminated Subsurface Sediments

    PubMed Central

    Martinez, Robert J.; Wu, Cindy H.; Beazley, Melanie J.; Andersen, Gary L.; Conrad, Mark E.; Hazen, Terry C.; Taillefert, Martial; Sobecky, Patricia A.

    2014-01-01

    Background Radionuclide- and heavy metal-contaminated subsurface sediments remain a legacy of Cold War nuclear weapons research and recent nuclear power plant failures. Within such contaminated sediments, remediation activities are necessary to mitigate groundwater contamination. A promising approach makes use of extant microbial communities capable of hydrolyzing organophosphate substrates to promote mineralization of soluble contaminants within deep subsurface environments. Methodology/Principal Findings Uranium-contaminated sediments from the U.S. Department of Energy Oak Ridge Field Research Center (ORFRC) Area 2 site were used in slurry experiments to identify microbial communities involved in hydrolysis of 10 mM organophosphate amendments [i.e., glycerol-2-phosphate (G2P) or glycerol-3-phosphate (G3P)] in synthetic groundwater at pH 5.5 and pH 6.8. Following 36 day (G2P) and 20 day (G3P) amended treatments, maximum phosphate (PO43−) concentrations of 4.8 mM and 8.9 mM were measured, respectively. Use of the PhyloChip 16S rRNA microarray identified 2,120 archaeal and bacterial taxa representing 46 phyla, 66 classes, 110 orders, and 186 families among all treatments. Measures of archaeal and bacterial richness were lowest under G2P (pH 5.5) treatments and greatest with G3P (pH 6.8) treatments. Members of the phyla Crenarchaeota, Euryarchaeota, Bacteroidetes, and Proteobacteria demonstrated the greatest enrichment in response to organophosphate amendments and the OTUs that increased in relative abundance by 2-fold or greater accounted for 9%–50% and 3%–17% of total detected Archaea and Bacteria, respectively. Conclusions/Significance This work provided a characterization of the distinct ORFRC subsurface microbial communities that contributed to increased concentrations of extracellular phosphate via hydrolysis of organophosphate substrate amendments. Within subsurface environments that are not ideal for reductive precipitation of uranium, strategies that

  12. The effect of extracellular polysaccharides on the goethite-surface promoted hydrolysis of organophosphates.

    NASA Astrophysics Data System (ADS)

    Kenney, J. P. L.; Olsson, R.; Giesler, R.; Persson, P.

    2012-04-01

    Organophosphate monoesters comprise a significant fraction of phosphate in soils. In order to access phosphorus needed for growth, plants and microorganisms often require the hydrolysis of large organophosphate molecules. This hydrolysis can be enzymatic or a reaction promoted by contact with an environmental surface. Because phosphorus strongly adsorbs to environmental particles, the fate and transport of phosphorus in the biosphere can be significantly impacted by reactions at the surfaces of these particles. Soil minerals, including the common Fe(III) mineral goethite, have been shown to increase the rate of hydrolysis of organophosphates by acting as catalysts. Many enzyme-secreting microbes and plants can also release extracellular polysaccharides (EPS) into their local environments. EPS is known to adsorb to environmental particles, including goethite. The adsorption of EPS may alter the physico-chemistry of the mineral-phosphate-enzyme system by impacting either the adsorption or enzymatic hydrolysis of organophosphate. Currently, there is little information available regarding the ability of EPS to enhance or inhibit the availability of essential nutrients, such as phosphate, in the environment. In this study we have investigated the hydrolysis of the phosphate monoesters, glucose phosphate (GP) and p-nitrophenyl phosphate (pNPP). To investigate the hydrolysis mechanisms and extent of hydrolysis of phosphate monoesters we studied three systems: 1) abiotic hydrolysis, where monoesters are adsorbed on goethite surfaces; 2) enzymatic hydrolysis where the monoesters are adsorbed to goethite then exposed to an enzyme; and 3) testing whether the presence of alginate, which is used as a model for EPS, can inhibit or enhance the abiotic or enzymatic hydrolysis. To investigate this we used infrared spectroscopy and the ATR sampling technique. Abiotic hydrolysis was examined using goethite as the environmental surface. Adsorption of each monoester to the goethite was

  13. DSN G/T(sub op) and telecommunications system performance

    NASA Technical Reports Server (NTRS)

    Stelzried, C.; Clauss, R.; Rafferty, W.; Petty, S.

    1992-01-01

    Provided here is an intersystem comparison of present and evolving Deep Space Network (DSN) microwave receiving systems. Comparisons of the receiving systems are based on the widely used G/T sub op figure of merit, which is defined as antenna gain divided by operating system noise temperature. In 10 years, it is expected that the DSN 32 GHz microwave receiving system will improve the G/T sub op performance over the current 8.4 GHz system by 8.3 dB. To compare future telecommunications system end-to-end performance, both the receiving systems' G/T sub op and spacecraft transmit parameters are used. Improving the 32 GHz spacecraft transmitter system is shown to increase the end-to-end telecommunications system performance an additional 3.2 dB, for a net improvement of 11.5 dB. These values are without a planet in the field of view (FOV). A Saturn mission is used for an example calculation to indicate the degradation in performance with a planet in the field of view.

  14. Pyrethroid and organophosphate pesticide-associated toxicity in two coastal watersheds (California, USA).

    PubMed

    Phillips, Bryn M; Anderson, Brian S; Hunt, John W; Siegler, Katie; Voorhees, Jennifer P; Tjeerdema, Ron S; McNeill, Katie

    2012-07-01

    Portions of the Santa Maria River and Oso Flaco Creek watersheds in central California, USA, are listed as impaired under section 303(d) of the Clean Water Act and require development of total maximum daily load (TMDL) allocations. These listings are for general pesticide contamination, but are largely based on historic monitoring of sediment and fish tissue samples that showed contamination by organochlorine pesticides. Recent studies have shown that toxicity in these watersheds is caused by organophosphate pesticides (water and sediment) and pyrethroid pesticides (sediment). The present study was designed to provide information on the temporal and spatial variability of toxicity associated with these pesticides to better inform the TMDL process. Ten stations were sampled in four study areas, one with urban influences, and the remaining in agriculture production areas. Water toxicity was assessed with the water flea Ceriodaphnia dubia, and sediment toxicity was assessed with the amphipod Hyalella azteca. Stations in the lower Santa Maria River had the highest incidence of toxicity, followed by stations influenced by urban inputs. Toxicity identification evaluations and chemical analysis demonstrated that the majority of the observed water toxicity was attributed to organophosphate pesticides, particularly chlorpyrifos, and that sediment toxicity was caused by mixtures of pyrethroid pesticides. The results demonstrate that both agriculture and urban land uses are contributing toxic concentrations of these pesticides to adjacent watersheds, and regional water quality regulators are now using this information to develop management objectives. PMID:22549911

  15. Calcium-activated butyrylcholinesterase in human skin protects acetylcholinesterase against suicide inhibition by neurotoxic organophosphates

    SciTech Connect

    Schallreuter, Karin U.; University of Bradford ). E-mail: K.Schallreuter@bradford.ac.uk; Gibbons, Nicholas C.J.; Elwary, Souna M.; Parkin, Susan M.; Wood, John M.

    2007-04-20

    The human epidermis holds an autocrine acetylcholine production and degradation including functioning membrane integrated and cytosolic butyrylcholinesterase (BuchE). Here we show that BuchE activities increase 9-fold in the presence of calcium (0.5 x 10{sup -3}M) via a specific EF-hand calcium binding site, whereas acetylcholinesterase (AchE) is not affected. {sup 45}Calcium labelling and computer simulation confirmed the presence of one EF-hand binding site per subunit which is disrupted by H{sub 2}O{sub 2}-mediated oxidation. Moreover, we confirmed the faster hydrolysis by calcium-activated BuchE using the neurotoxic organophosphate O-ethyl-O-(4-nitrophenyl)-phenylphosphonothioate (EPN). Considering the large size of the human skin with 1.8 m{sup 2} surface area with its calcium gradient in the 10{sup -3}M range, our results implicate calcium-activated BuchE as a major protective mechanism against suicide inhibition of AchE by organophosphates in this non-neuronal tissue.

  16. Development of Immunochromatographic Assay for Identification of Organophosphate Pesticides in Environmental Samples.

    PubMed

    Srivastava, Shruti; Ghorpade, Ramrao; Sathe, Manisha

    2016-01-01

    Microtiter plate enzyme linked immunoassay (ELISA) experiments in competitive format were performed utilizing polyclonal antibody for establishing a detection system for organophosphate pesticides. IC50 value of and limit of detection (LOD) value was determined by standard inhibition curve and value obtained were 0.05 μgmL(-1) and 0.001 μgmL(-1), respectively. Specificity of antibody was investigated with different organophosphate pesticides. Immunochromatographic assay (ICA) experiments were also designed in competitive format by making use of immunochromatographic strip which was assembly of three main components: conjugate pad, membrane and adsorbent pad. Membrane was coated with hapten-OVA conjugate (test line) and antirabbit IgG (control line). ICA experiments were performed by employing gold-labeled antibody as a detector reagent which was applied over conjugate pad. Visual detection limit obtained from ICA was 0.5 μgmL(-1). Major advantage of strip assay was rapid result, i.e., less than 10 min. which makes it suitable for onsite applications.

  17. Investigation of gastrointestinal effects of organophosphate and carbamate pesticide residues on young children.

    PubMed

    Jones, K; Everard, M; Harding, A-H

    2014-03-01

    This prospective study was designed to investigate whether there is any association between gastrointestinal effects and pesticide residue exposure (as measured by metabolite levels in urine and faecal samples) in young children and to describe background levels of pesticide residues in samples from healthy children in the UK. Children (N=136) between the ages of 1.0 and 4.2 years were recruited. Of these, 107 provided background baseline samples and 26 provided samples when suffering from gastrointestinal symptoms. Urine samples (from all populations) were positive for (non-specific) carbaryl metabolite (urine 19/78, faeces 9/99), organophosphate metabolites (urine 103/135, faeces 47/111) and pirimicarb metabolite (urine 72/175, faeces 45/135). There were no statistically significant differences between samples from children when healthy or unwell. The urinary 95th percentile values for the healthy population of young children in this study were 31 nmol/l (carbaryl metabolite), 2156 nmol/l (total organophosphate metabolites) and 139 nmol/l (pirimicarb metabolite). In this study, samples from children suffering gastrointestinal symptoms were no more associated with anti-cholinergic pesticide metabolite levels or rotaviral infection than samples from healthy children. Background levels of anti-cholinergic pesticide metabolites in healthy UK children were in agreement with previously reported levels from the US and Germany.

  18. [Cross resistance to pyrethroids in Aedes aegypti from Cuba induced by the selection with organophosphate malathion].

    PubMed

    Rodríguez, María Magdalena; Bisset, Juan A; Díaz, Cristina; Soca, Lázaro A

    2003-01-01

    A strain from Aedes aegypti (L) collected in the municipality of Santiago de Cuba with low levels of resistance to malathion (1.79x) was subjected to selection pressure aimed at evaluating the evolution of the resistance to this organophosphate and its usefulness for control. After 5 generations of selection (SAN-F5) with malathion, it was not possible to increase the resistance and it was obtained a value of resistance factor (FR50) of 2.22x. None or little cross resistance to the following organophosphate insecticides was observed: fenthion, temephos and fenitrotion; however, it was found an elevated cross resistance to deltamethrin pyrethroid, with a value of 287.5x in the third generation of selection. It was also observed cross resistance to other pyrethroids (lambda-cyhalothrin, cypermethrin and ciflutrine). The mechansim of elevated esterases did not generate resistance to pyrethroids, which was corroborated through inhibition gel studies and through the calculation of the frequency in microtitering plaques. Nevertheless, there was an increase in the frequency of the glutathione-s-transferase mechanism from 0.049 in Santiago de Cuba to 0.42 in SAN-F5, which may be associated with the resistance to pyrethroids. The cross resistance to pyrethroids, mainly to deltamethrin, resulting from the selection with malathion may limit the use of these insecticides in the control unless a good strategy for their use is laid down. PMID:15849966

  19. Ionic liquids composed of phosphonium cations and organophosphate, carboxylate, and sulfonate as lubricant antiwear additives

    DOE PAGES

    Zhou, Yan; Dyck, Jeffrey; Graham, Todd; Luo, Huimin; Leonard, Donovan N.; Qu, Jun

    2014-10-20

    Oil-soluble phosphonium-based ionic liquids (ILs) have recently been reported as potential ashless lubricant additives. This study is to expand the IL chemistry envelope and to achieve fundamental correlations between the ion structures and ILs’ physiochemical and tribological properties. Here we present eight ILs containing two different phosphonium cations and seven different anions from three groups: organophosphate, carboxylate, and sulfonate. The oil solubility of ILs seems largely governed by the IL molecule size and structure complexity. When used as oil additives, the ranking of effectiveness in wear protection for the anions are: organophosphate > carboxylate > sulfonate. All selected ILs outperformedmore » a commercial ashless anti-wear additive. Surface characterization from the top and the cross-section revealed the nanostructures and compositions of the tribo-films formed by the ILs. Some fundamental insights were achieved: branched and long alkyls improve the IL’s oil solubility, anions of a phosphonium-phosphate IL contribute most phosphorus in the tribofilm, and carboxylate anions, though free of P, S, N, or halogen, can promote the formation of an anti-wear tribofilm.« less

  20. Pyrethroid and organophosphate pesticide-associated toxicity in two coastal watersheds (California, USA).

    PubMed

    Phillips, Bryn M; Anderson, Brian S; Hunt, John W; Siegler, Katie; Voorhees, Jennifer P; Tjeerdema, Ron S; McNeill, Katie

    2012-07-01

    Portions of the Santa Maria River and Oso Flaco Creek watersheds in central California, USA, are listed as impaired under section 303(d) of the Clean Water Act and require development of total maximum daily load (TMDL) allocations. These listings are for general pesticide contamination, but are largely based on historic monitoring of sediment and fish tissue samples that showed contamination by organochlorine pesticides. Recent studies have shown that toxicity in these watersheds is caused by organophosphate pesticides (water and sediment) and pyrethroid pesticides (sediment). The present study was designed to provide information on the temporal and spatial variability of toxicity associated with these pesticides to better inform the TMDL process. Ten stations were sampled in four study areas, one with urban influences, and the remaining in agriculture production areas. Water toxicity was assessed with the water flea Ceriodaphnia dubia, and sediment toxicity was assessed with the amphipod Hyalella azteca. Stations in the lower Santa Maria River had the highest incidence of toxicity, followed by stations influenced by urban inputs. Toxicity identification evaluations and chemical analysis demonstrated that the majority of the observed water toxicity was attributed to organophosphate pesticides, particularly chlorpyrifos, and that sediment toxicity was caused by mixtures of pyrethroid pesticides. The results demonstrate that both agriculture and urban land uses are contributing toxic concentrations of these pesticides to adjacent watersheds, and regional water quality regulators are now using this information to develop management objectives.

  1. Ionic liquids composed of phosphonium cations and organophosphate, carboxylate, and sulfonate as lubricant antiwear additives

    SciTech Connect

    Zhou, Yan; Dyck, Jeffrey; Graham, Todd; Luo, Huimin; Leonard, Donovan N.; Qu, Jun

    2014-10-20

    Oil-soluble phosphonium-based ionic liquids (ILs) have recently been reported as potential ashless lubricant additives. This study is to expand the IL chemistry envelope and to achieve fundamental correlations between the ion structures and ILs’ physiochemical and tribological properties. Here we present eight ILs containing two different phosphonium cations and seven different anions from three groups: organophosphate, carboxylate, and sulfonate. The oil solubility of ILs seems largely governed by the IL molecule size and structure complexity. When used as oil additives, the ranking of effectiveness in wear protection for the anions are: organophosphate > carboxylate > sulfonate. All selected ILs outperformed a commercial ashless anti-wear additive. Surface characterization from the top and the cross-section revealed the nanostructures and compositions of the tribo-films formed by the ILs. Some fundamental insights were achieved: branched and long alkyls improve the IL’s oil solubility, anions of a phosphonium-phosphate IL contribute most phosphorus in the tribofilm, and carboxylate anions, though free of P, S, N, or halogen, can promote the formation of an anti-wear tribofilm.

  2. Acetylcholinesterase Inhibition as an Indicator of Organophosphate and Carbamate Poisoning in Kenyan Agricultural Workers.

    PubMed

    Ohayo-Mitoko; Heederik; Kromhout; Omondi; Boleij

    1997-07-01

    Acetylcholinesterase inhibition was determined for 666 Kenyan agricultural workers; 390 (58.6%) mainly pesticide applicators exposed to organophosphate and carbamate pesticides and 276 (41.4%) unexposed controls from four rural agricultural areas during 1993 and 1994. Baseline levels were depressed in the exposed group (6.1 +/- 0.84; 4.09 +/- 0.84) but not in the unexposed group (5.83 +/- 0.91; 5.60 +/- 0.87). Acetylcholinesterase inhibition was found in all exposed individuals and led, on average, to a decrease of baseline acetylcholinesterase levels of 33% (+/-12%). The control groups had a nonsignificant decrease of only 4% (+/- 8%). The exposed subjects in Naivasha (flower growers) had the largest inhibition (36%), followed by Homabay (cotton growers) (35%) and Wundanyi (vegetable growers) (33%). Those in Migori (tobacco growers) had, by far, the least inhibition of acetylcholinesterase activity (26%), indicating inherent factors that led to less inhibition. Acetylcholinesterase activity levels of 115 exposed individuals (29.6%) and no controls were depressed to values below 60% of baseline levels. The dramatic inhibition observed could lead to chronic clinical and subclinical intoxication. These findings show that acetylcholinesterase inhibition can be used as an indicator of organophosphate and carbamate poisoning in occupationally exposed agricultural workers. There is, therefore, an urgent need for primary prevention programs to monitor and address occupational exposures to these hazardous substances in agriculture in Kenya and other developing countries, as well as to use integrated pest management strategies in crop protection.

  3. Response of common grackles to dietary concentrations of four organophosphate pesticides

    USGS Publications Warehouse

    Grue, C.E.

    1982-01-01

    Behavioral and physiological responses of common grackles to dietary concentrations of dicrotophos, fenitrothion, fenthion, and methyl parathion suggest mortality was largely due to pesticide-induced anorexia. Mortality was dose related, though consumption of treated diets was reduced such that birds on different geometrically arranged concentrations of the same pesticide ingested about the same amount of toxicant. Grackles that died lost an average of 28 to 36% of their initial body weight; visible fat was absent and muscle tissue was reduced on the sternum. Mortality of birds exposed to dicrotophos increased between May and August, although chemical intake remained relatively constant, and was associated with a natural decrease in fat and flesh condition in response to increased ambient temperatures and post-nuptial molt. Food consumption in songbirds exposed to organophosphates may be reduced significantly up to 12 hr after exposure ceases because of an unknown effect of these chemicals on their feeding behavior, but not repellency. The results caution against using median lethal dietary concentrations for other than ranking chemicals based on their relative toxicity, particularly in establishing safe environmental levels, and suggest that anorexia and physiological condition may be important factors in mortality of wild birds exposed to organophosphates.

  4. Purification and properties of an esterase from organophosphate-resistant strain of the mosquito Culex quinquefasciatus.

    PubMed Central

    Merryweather, A T; Crampton, J M; Townson, H

    1990-01-01

    Organophosphate-resistant and -susceptible strains of Culex quinquefasciatus (mosquito) have been compared on the basis of their esterase activities. The homozygous resistant strain (Dar) shows two highly active esterases after starch-gel electrophoresis, of Rm 0.2 and 0.4, which are absent from susceptible strains (Apo, Mon), and which previous selection studies have shown to be inseparable from organophosphate resistance. After SDS/polyacrylamide-gel electrophoresis and silver staining of total C. quinquefasciatus proteins, a 62 kDa band is observed in strain Dar at high concentrations, and in susceptible strains in trace amounts. After Western blotting, this 62 kDa protein is recognized by antisera raised against the two esterases eluted from starch gels. After chromatofocusing of Dar proteins, the 62 kDa protein is seen to be associated with esterase activity, and of a similar pI to that observed for esterases after isoelectric focusing. Post-translational modification is not required for recognition of the 62 kDa putative esterase, since the protein is immunoprecipitated by the anti-esterase serum from products of translation of Dar mRNA in vitro. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 6. Fig. 7. PMID:2178604

  5. Microwave-assisted extraction of organophosphate flame retardants and plasticizers from indoor dust samples.

    PubMed

    García, M; Rodríguez, I; Cela, R

    2007-06-01

    A procedure for the determination of eight organophosphate flame retardants and plasticizers in dust samples is presented. Microwave-assisted extraction and gas chromatography (GC) with nitrogen-phosphorus detection (NPD) were used for sample preparation and analytes quantification, respectively. Influence of different variables (type and volume of organic solvent, temperature, time, agitation, etc.) on the yield of the extraction step was evaluated. The most important factor was the type of solvent, with the highest efficiencies corresponding to acetone. Under final conditions 10 mL of this solvent were employed. The extraction was carried out at 130 degrees C and satisfactory yields, similar to those obtained with the Soxhlet technique, were achieved. Due to the high content of organic carbon in dust samples, primary acetone extracts had to be subjected to intensive clean-up. Dilution with ultrapure water followed by concentration on a reversed-phase sorbent and further purification using silica, allowed a significant reduction of co-extracted interferences. Application of the developed methodology to indoor dust from private houses showed important concentrations of several organophosphate esters. The highest levels, up to 19 microg/g, corresponded to tris(butoxyethyl) phosphate; moreover, average values of two chlorinated compounds, used as flame retardants and considered as the most concerning species in the group, exceeded the 1 microg/g level. PMID:17140588

  6. Transcriptional profiles for glutamate transporters reveal differences between organophosphates but similarities with unrelated neurotoxicants.

    PubMed

    Slotkin, Theodore A; Lobner, Doug; Seidler, Frederic J

    2010-08-30

    The developmental neurotoxicity of organophosphates involves mechanisms other than their shared property as cholinesterase inhibitors, among which are excitotoxicity and oxidative stress. We used PC12 cells as a neurodevelopmental model to compare the effects of chlorpyrifos and diazinon on the expression of genes encoding glutamate transporters. Chlorpyrifos had a greater effect in cells undergoing nerve growth factor-induced neurodifferentiation as compared to undifferentiated PC12 cells, with peak sensitivity at the initiation of differentiation, reflecting a global upregulation of all the glutamate transporter genes expressed in this cell line. In differentiating cells, chlorpyrifos had a significantly greater effect than did diazinon and concordance analysis indicated no resemblance in their expression patterns. At the same time, the smaller effects of diazinon were highly concordant with those of an organochlorine pesticide (dieldrin) and a metal (divalent nickel). We also performed similar evaluations for the cystine/glutamate exchanger, which provides protection against oxidative stress by moving cystine into the cell; again, chlorpyrifos had the greatest effect, in this case reducing expression in undifferentiated and differentiating cells. Our results point to excitotoxicity and oxidative stress as major contributors to the noncholinesterase mechanisms that distinguish the neurodevelopmental outcomes between different organophosphates while providing a means whereby apparently unrelated neurotoxicants may produce similar outcomes. PMID:20600679

  7. Correlation between organophosphate poisoning, acetylcholinesterase inhibition, and increased cyclic GMP levels in malathion-treated insects.

    PubMed

    Bodnaryk, R P

    1977-05-01

    Organophosphate poisoning with malathion caused large increases (up to 125 and 440%, respectively) in the level of cyclic GMP in larvae of Mamestra configurata Wlk. and in the fly Sarcophaga bullata Parker. Cyclic AMP was little affected. The malathion-induced increase in cyclic GMP was time and dose dependent. Time-course studies with the head and thorax of S. bullata demonstrated that the increase in cyclic GMP level occurred precipitously after a lag period of about 1 h, during which time the activity of acetylcholinesterase (EC 3.1.1.7) was progressively inhibited. The abrupt increase in cyclic GMP began when acetylcholinesterase activity had been inhibited to a sufficient extent to permit accumulation of acetylcholine. It is suggested that the accumulation of acetylcholine in the malathion-poisoned insects caused cyclic GMP levels to rise. Cyclic GMP may have a role in cholinergic transmission in normally functioning insect neural tissue. Increased levels of cyclic GMP induced by organophosphate and organocholorine (Bodnaryk, R. P. (1976) Can. J. Biochem. 54, 957-962) insecticides appear to be a vital and previously unrecognized biochemical lesion in insects poisoned by these compounds.

  8. Safety measures associated with the use of organophosphate insecticides in the Haitian malaria control programme*

    PubMed Central

    Warren, McWilson; Ruebush, Trenton K.; Hobbs, Jesse H.; Hippolyte, Robert; Miller, Steve

    1985-01-01

    A programme emphasizing intensive training, use of protective equipment and uniforms, daily supervision of safety measures at work, and weekly monitoring of blood cholinesterase levels by the tintometric method was instituted to prevent toxicity in Haitian malaria workers during spraying with the organophosphate insecticides fenitrothion and malathion. The programme functioned well, depressed cholinesterase activity (≤ 50% of normal) being detected rapidly prior to the development of serious symptoms. Evidence of fenitrothion overexposure appeared in spraymen early in the first spray cycle, and was associated with faulty protective clothing and a failure to observe strictly the recommended safety measures at work. After these deficiencies were corrected, insecticide application continued without serious incidents or interruption of the programme. No serious reduction of cholinesterase activity was seen in a more limited study of spraymen using malathion. It is strongly recommended that similar training and monitoring programmes should be instituted whenever organophosphate pesticides are used as residual sprays for malaria control. This is particularly important in areas where the more toxic compound, fenitrothion, is to be used. PMID:3874715

  9. Bioactive Paper Sensor Based on the Acetylcholinesterase for the Rapid Detection of Organophosphate and Carbamate Pesticides

    PubMed Central

    Badawy, Mohamed E. I.; El-Aswad, Ahmed F.

    2014-01-01

    In many countries, people are becoming more concerned about pesticide residues which are present in or on food and feed products. For this reason, several methods have been developed to monitor the pesticide residue levels in food samples. In this study, a bioactive paper-based sensor was developed for detection of acetylcholinesterase (AChE) inhibitors including organophosphate and carbamate pesticides. Based on the Ellman colorimetric assay, the assay strip is composed of a paper support (1 × 10 cm), onto which a biopolymer chitosan gel immobilized in crosslinking by glutaraldehyde with AChE and 5,5′-dithiobis(2-nitrobenzoic) acid (DTNB) and uses acetylthiocholine iodide (ATChI) as an outside reagent. The assay protocol involves introducing the sample to sensing zone via dipping of a pesticide-containing solution. Following an incubation period, the paper is placed into ATChI solution to initiate enzyme catalyzed hydrolysis of the substrate, causing a yellow color change. The absence or decrease of the yellow color indicates the levels of the AChE inhibitors. The biosensor is able to detect organophosphate and carbamate pesticides with good detection limits (methomyl = 6.16 × 10−4 mM and profenofos = 0.27 mM) and rapid response times (~5 min). The results show that the paper-based biosensor is rapid, sensitive, inexpensive, portable, disposable, and easy-to-use. PMID:25484901

  10. Detecting resistance to organophosphates and carbamates in the cattle tick Boophilus microplus, with a propoxur-based biochemical test.

    PubMed

    Baxter, G D; Green, P; Stuttgen, M; Barker, S C

    1999-11-01

    Rapid and sensitive detection of resistance to insecticides in arthropods is needed. In the cattle tick. Boophilus microplus, resistance to a variety of acaricides is widespread. The most commonly used assay for resistance, the larval packet test, takes at least two, but generally six weeks for a one-host tick like B. microplus to complete and may take up to three months to complete for three-host ticks. Here we describe a test for resistance to organophosphate acaricides that can be used on larvae and adult ticks which takes less than 24 hours. The test measures the difference in acetylcholinesterase (AChE) activity in homogenates of ticks in the presence and absence of propoxur, a carbamate acaricide. We found clear discrimination of organophosphate-susceptible and organophosphate-resistant adults with 100 microM propoxur. AChE from susceptible ticks had almost no activity at this concentration of propoxur whereas AChE from resistant ticks had 67% of its potential activity. AChE from heterozygote ticks could also be distinguished from AChE from homozygous-susceptible and homozygous-resistant ticks. This is the first biochemical test for resistance to an acaricide. Rapid, sensitive tests like ours will allow resistance to organophosphates to be detected soon after it develops in the field, thus, the spread of resistance might be slowed and the useful life of acaricides extended.

  11. Long-term neurobehavioral effects of mild poisonings with organophosphate and n-methyl carbamate pesticides among banana workers.

    PubMed

    Wesseling, Catharina; Keifer, Matthew; Ahlbom, Anders; McConnell, Rob; Moon, Jai-Dong; Rosenstock, Linda; Hogstedt, Christer

    2002-01-01

    Organophosphate poisoning has been associated with chronic neurobehavioral dysfunction, but no epidemiologic data exist with regard to long-term consequences from carbamate poisoning. This cross-sectional study evaluated the neurobehavioral performances of 81 banana workers who, on average 27 months earlier, had received medical attention not requiring hospitalization for mild occupational poisoning by either an organophosphate or a carbamate pesticide. These performances were compared with those of 130 banana workers who had never sought medical attention for pesticide poisoning. Poisoned subjects did less well than controls on tests measuring psychomotor and visuomotor skills, language function, and affect, the differences being significant for coding skills on the Digit-Symbol test and two tests of neuropsychiatric symptoms. These deficits, in particular a marked increase of neuropsychiatric symptoms, occurred among the organophosphate-poisoned subjects, but small deficits in performance were also seen in the carbamate-poisoned subjects. The performances of the previously poisoned subjects who had had contact with cholinesterase inhibitors within three months before testing were particularly poor. These findings in workers with mild poisoning are consistent with previous findings of persistent damage to the central nervous system from organophosphate poisoning. The possibility of persistent neurobehavioral effects associated with poisonings by nmethyl carbamate insecticides cannot be excluded. Workers with histories of poisoning may be more susceptible to neurobehavioral effects with subsequent exposures.

  12. Susceptibility of redbanded and conchuela stink bugs from the Texas Lower Rio Grande Valley to organophosphate and pyrethroid insecticides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report the susceptibility of 2 stink bug species, red banded stink bug (RBSB), Piezodorus guildinii, (Westwood) and conchuela stinkbug, Chlorochroa ligata (Say) collected in the Texas Lower Rio Grande Valley to selected pyrethroid and organophosphate technical grade insecticides. The adult glass ...

  13. Brain acetylcholinesterase activity recovery following acute methyl parathion intoxication in two feral rodent species: comparison to laboratory rodents

    SciTech Connect

    Roberts, D.K.; Silvey, N.J.; Bailey, E.M. Jr.

    1988-07-01

    Widespread use of organophosphorus insecticides (OPs) has produced both acute and chronic intoxication among nontarget organisms. Most such studies have included fish and birds as opposed to mammals. However, numerous OP toxicity studies have been conducted on laboratory rodents creating a temptation to apply this data to feral rodents. Chronic OP exposure has been reported to produce cholinergic adaptation which in turn lowers mortality rates following a subsequent acute anticholinesterase exposure. The relevance that these laboratory rodent studies have on feral rodents is subject to debate. Field studies involving OP exposure among nontarget feral mammals have produced contradictory results. Increased mortality as a result of repeated OP application has been reported. This observation may be of considerable importance to nontarget feral rodent populations due to the repetitive nature of OP application protocols. The ability of feral rodents to recover brain AChE activity (BAA) between OP application intervals undoubtedly promotes their survival. This study investigated and compared BAA recovery following acute oral methyl parathion intoxication among 2 feral rodent species and among 2 common laboratory rodent species.

  14. Acute Bronchitis

    MedlinePlus

    ... tightness. There are two main types of bronchitis: acute and chronic. Most cases of acute bronchitis get better within several days. But your ... that cause colds and the flu often cause acute bronchitis. These viruses spread through the air when ...

  15. Correlation between Cholinesterase and Paraoxonase 1 Activities:Case Series of Pesticide Poisoning Subjects

    PubMed Central

    Richard, S Austin; Frank, Elizabeth A; D'Souza, Cletus J M

    2013-01-01

    Introduction: Acute exposure to pesticide due to suicidal poisoning is the most extensive cause of pesticide exposure, compared with all other causes including agricultural or industrial exposure. Organophosphate (OP) and carbamate group of pesticides can inhibit acetylcholinesterase; on the other hand, paraoxonase1 can detoxify organophosphate poisoning by hydrolyzing organophosphate metabolites. Methods: We have compared the serum paraoxonase1 status and cholinesterase activity of subjects who attempted to commit suicide by consuming OP pesticide. Cholinesterase and paraoxonase1 activity were measured spectrophotometrically using butyrylthiocholine and phenyl acetate as substrates, respectively. Results: A positive correlation was found between serum paraoxonase1 activity and cholinesterase activity among pesticide consumed subjects. Conclusion: Our results suggest that subjects with higher paraoxonase1 activity may have a better chance of detoxifying the lethal effect of acute organophosphate poisoning. PMID:24163803

  16. Association of in Utero Organophosphate Pesticide Exposure and Fetal Growth and Length of Gestation in an Agricultural Population

    PubMed Central

    Eskenazi, Brenda; Harley, Kim; Bradman, Asa; Weltzien, Erin; Jewell, Nicholas P.; Barr, Dana B.; Furlong, Clement E.; Holland, Nina T.

    2004-01-01

    Although pesticide use is widespread, little is known about potential adverse health effects of in utero exposure. We investigated the effects of organophosphate pesticide exposure during pregnancy on fetal growth and gestational duration in a cohort of low-income, Latina women living in an agricultural community in the Salinas Valley, California. We measured nonspecific metabolites of organophosphate pesticides (dimethyl and diethyl phosphates) and metabolites specific to malathion (malathion dicarboxylic acid), chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridinyl) phosphoro-thioate], and parathion (4-nitrophenol) in maternal urine collected twice during pregnancy. We also measured levels of cholinesterase in whole blood and butyryl cholinesterase in plasma in maternal and umbilical cord blood. We failed to demonstrate an adverse relationship between fetal growth and any measure of in utero organophosphate pesticide exposure. In fact, we found increases in body length and head circumference associated with some exposure measures. However, we did find decreases in gestational duration associated with two measures of in utero pesticide exposure: urinary dimethyl phosphate metabolites [βadjusted = −0.41 weeks per log10 unit increase; 95% confidence interval (CI), −0.75–−0.02; p = 0.02], which reflect exposure to dimethyl organophosphate compounds such as malathion, and umbilical cord cholinesterase (βadjusted = 0.34 weeks per unit increase; 95% CI, 0.13–0.55; p = 0.001). Shortened gestational duration was most clearly related to increasing exposure levels in the latter part of pregnancy. These associations with gestational age may be biologically plausible given that organophosphate pesticides depress cholinesterase and acetylcholine stimulates contraction of the uterus. However, despite these observed associations, the rate of preterm delivery in this population (6.4%) was lower than in a U.S. reference population. PMID:15238287

  17. Lower nasopharyngeal epithelial cell repair and diminished innate inflammation responses contribute to the onset of acute otitis media in otitis-prone children.

    PubMed

    Verhoeven, David; Nesselbush, Monica; Pichichero, Michael E

    2013-08-01

    About 30 % of young children experience excessive, frequent episodes of middle ear infection and are classified as acute otitis media prone (OP). Streptococcus pneumoniae (Spn) is a predominant otopathogen in OP and non-OP (NOP) children. The pathogenesis of middle ear infection involves otopathogen nasopharyngeal (NP) colonization followed by an upper respiratory viral infection that modifies the NP environment to allow a sufficient inoculum of bacteria to reflux via the Eustachian tube into the middle ear space. Here, we analyzed the NP mucosal repair response between age-matched stringently defined OP (sOP) and NOP children who progressed to middle ear infection caused by Spn. We found lower epidermal growth factor, epidermal growth factor receptor, and angiogenin cytokine concentrations in nasal washes of sOP compared with NOP children. Despite higher expression of TLR2/4 transcript expression in nasal epithelium and in polymorphonuclear cells present in nasal secretions in sOP children, sOP children had lower expression of proinflammatory cytokines such as IL-6 and IL-8 in the NP. Chemotaxis-associated cytokine expression at onset of AOM in sOP children was also lower compared with NOP children, possibly indicating a lower capacity to signal the innate immune system. We conclude that lower epithelial cell repair responses during viral infection in the NP combined with diminished innate inflammatory responses potentiate Spn pathogenesis in the sOP child.

  18. Bio-inspired Supramolecular Assemblies and Porous Materials for the Degradation of Organophosphate Nerve Agents

    NASA Astrophysics Data System (ADS)

    Totten, Ryan K.

    This thesis reports the synthesis of bio-inspired supramolecular assemblies and porous materials that are catalytically active in the degradation of organophosphate nerve agents. The first catalysts described are a series of cofacial metalloporphyrin dimers modeled after the active site of phosphotriesterase that were modularly prepared from a single porphyrin building block and shown to catalyze the methanolysis of p-nitrophenyl diphenyl phosphate (PNPDPP), a simulant for nerve agents. Notably, tuning the active sites inside the cavities of these dimers, from ZnII metal centers to Al-OMe moieties, affords an enhanced nucleophilic environment where a high concentration of methoxy ligands becomes available for reaction with encapsulated phosphate triesters. Up to a 1300-fold rate acceleration over the uncatalyzed reaction can be achieved via a combination of cavity-localized Lewis-acid activation and methoxide-induced methanolysis. Based on the design principles learned from the aforementioned solution-phase Al(porphyrin) dimers, a heterogeneous porous organic polymer (POP) catalyst was synthesized by incorporating an Al(porphyrin) functionalized with a large axial ligand into a POP using a cobalt-catalyzed acetylene trimerization strategy. Removal of the axial ligand afforded a microporous material that is capable of encapsulating and solvolytically degrading PNPDPP. Supercritical CO 2 processing of the Al(porphyrin)-based POP dramatically increased the pore size and volume, allowing for significantly higher catalytic activities. The syntheses of porphyrin-based POPs with tunable pore diameters and volumes have also been attempted. SnIV(porphyrins) functionalized with bulky trans-diaxial ligands can be incorporated into POPs. Post-synthesis removal of the ligands reveal POPs with a tunable range of micro- and mesopores as well as tunable pore volumes. Expanding upon the idea that active sites that can both bind substrates and deliver nucleophiles should be active

  19. Op. amps in power amplification: a laboratory exercise on feedback

    NASA Astrophysics Data System (ADS)

    Borcherds, P. H.

    1984-05-01

    Rapid and continuing developments in electronics make it necessary to revise constantly the teaching of electronics and to replace obsolescent laboratory exercises. The author describes a new exercise which believes helps students' (and lecturers') understanding of negative feedback. A power amplifier is constructed from an operational amplifier (op. amp.) together with a complementary pair of transistors as an output stage. To make the exercise more realistic a low impedance (8 Omega ) loudspeaker is used as the load. The amplifier is developed and tested stage by stage, and at each stage the defects apparent at the previous stage are eliminated.

  20. Organophosphate poisoning.

    PubMed

    Gerald, Daniel R

    2002-11-01

    Stay safe! Certain scenes and scenarios invite a greater degree of caution. Wear protective gear (Level B for decon) and make sure the patient is hazmat-naked prior to decontamination. Use tincture of green soap or household dishwashing soap to decontaminate your patient. Maintain the patient's airway using oral/nasal airways; intubate if indicated. Give high-flow oxygen by nonrebreather oxygen mask or, if intubated, with a bagh-valve mask. Treat for shock by maintaining the patient's body temperature, keeping them supine if they will tolerate it, and gaining i.v. access. Administer oxygen, atropine, pralidoxime chloride and diazepam as required. Notify the ED and transport rapidly. If it is a terrorist incident, get your patient and get out. PMID:12440317

  1. Discovery of New Classes of Compounds that Reactivate Acetylcholinesterase Inhibited by Organophosphates

    PubMed Central

    Schneider, Laura; Zhu, Zhengxiang; Ton-That, Long; Luzac, Michal; Zlatanic, Viktor; Damera, Shivani; Macdonald, Joanne; Landry, Donald W.; Tong, Liang; Stojanovic, Milan N.

    2015-01-01

    Acetylcholinesterase (AChE) that has been covalently inhibited by organophosphate compounds (OPCs), such as nerve agents and pesticides, has traditionally been reactivated by using nucleophilic oximes. There is, however, a clearly recognized need for new classes of compounds with the ability to reactivate inhibited AChE with improved in vivo efficacy. Here we describe our discovery of new functional groups—Mannich phenols and general bases—that are capable of reactivating OPC-inhibited AChE more efficiently than standard oximes and we describe the cooperative mechanism by which these functionalities are delivered to the active site. These discoveries, supported by preliminary in vivo results and crystallographic data, significantly broaden the available approaches for reactivation of AChE. PMID:26350723

  2. Reflectometric cutinase assay for rapid screening of contaminants and residues of insecticidal organophosphates and carbamates.

    PubMed

    Walz, Ingrid; Schwack, Wolfgang

    2008-01-01

    Because of the extensive use of insecticides in agriculture, there is an increasing demand for rapid analytical methods for residues in food and feed control. To meet this need, a completely new application of the reflectometric lipase test (Reflectoquant, Merck) was developed. By using the cutinase-induced reaction of the substrate 5-bromo-4-chloro-3-indoxyl caprylate on the test strips, residues of organophosphates and carbamates can be determined on the basis of enzyme inhibition in a fast and inexpensive way. With this technique, we investigated the inhibition effects of representative insecticides, i.e., chlorpyrifos oxon, paraoxon, and carbaryl. The bimolecular inhibitory rate constants (ki) were found to agree well with those obtained by a previously described spectrophotometric cutinase assay in the microtiter-plate format. Recoveries determined with the strip test from spiked samples compared well with those obtained by both the cutinase microtiter-plate assay and liquid chromatographylmass spectrometry.

  3. Feasibility of hair sampling to assess levels of organophosphate metabolites in rural areas of Sri Lanka

    PubMed Central

    Knipe, D.W.; Jayasumana, C.; Siribaddana, S.; Priyadarshana, C.; Pearson, M.; Gunnell, D.; Metcalfe, C.; Tzatzarakis, M.N.; Tsatsakis, A.M.

    2016-01-01

    Measuring chronic pesticide exposure is important in order to investigate the associated health effects. Traditional biological samples (blood/urine) are difficult to collect, store and transport in large epidemiological studies in settings such as rural Asia. We assessed the acceptability of collecting hair samples from a rural Sri Lankan population and found that this method of data collection was feasible. We also assessed the level of non-specific metabolites (DAPS) of organophosphate pesticides in the hair samples. The median concentration (pg/mg) of each DAP was: diethyl phosphate: 83.3 (IQI 56.0, 209.4); diethyl thiophosphate: 34.7 (IQI 13.8, 147.9); diethyl dithiophosphate: 34.5 (IQI 23.4, 55.2); and dimethyl phosphate: 3 (IQI 3, 109.7). Total diethylphosphates were recovered in >80% of samples and were positively correlated with self-reported pesticide exposure. PMID:26894816

  4. Heart Rate-Corrected QT Interval Helps Predict Mortality after Intentional Organophosphate Poisoning

    PubMed Central

    Liu, Shou-Hsuan; Lin, Ja-Liang; Weng, Cheng-Hao; Yang, Huang-Yu; Hsu, Ching-Wei; Chen, Kuan-Hsing; Huang, Wen-Hung; Yen, Tzung-Hai

    2012-01-01

    Introduction In this study, we investigated the outcomes for patients with intentional organophosphate poisoning. Previous reports indicate that in contrast to normal heart rate-corrected QT intervals (QTc), QTc prolongation might be indicative of a poor prognosis for patients exposed to organophosphates. Methods We analyzed the records of 118 patients who were referred to Chang Gung Memorial Hospital for management of organophosphate poisoning between 2000 and 2011. Patients were grouped according to their initial QTc interval, i.e., normal (<0.44 s) or prolonged (>0.44 s). Demographic, clinical, laboratory, and mortality data were obtained for analysis. Results The incidence of hypotension in patients with prolonged QTc intervals was higher than that in the patients with normal QTc intervals (P = 0.019). By the end of the study, 18 of 118 (15.2%) patients had died, including 3 of 75 (4.0%) patients with normal QTc intervals and 15 of 43 (34.9%) patients with prolonged QTc intervals. Using multivariate-Cox-regression analysis, we found that hypotension (OR = 10.930, 95% CI = 2.961–40.345, P = 0.000), respiratory failure (OR = 4.867, 95% CI = 1.062–22.301, P = 0.042), coma (OR = 3.482, 95% CI = 1.184–10.238, P = 0.023), and QTc prolongation (OR = 7.459, 95% CI = 2.053–27.099, P = 0.002) were significant risk factors for mortality. Furthermore, it was revealed that non-survivors not only had longer QTc interval (503.00±41.56 versus 432.71±51.21 ms, P = 0.002), but also suffered higher incidences of hypotension (83.3 versus 12.0%, P = 0.000), shortness of breath (64 versus 94.4%, P = 0.010), bronchorrhea (55 versus 94.4%, P = 0.002), bronchospasm (50.0 versus 94.4%, P = 0.000), respiratory failure (94.4 versus 43.0%, P = 0.000) and coma (66.7 versus 11.0%, P = 0.000) than survivors. Finally, Kaplan-Meier analysis demonstrated that cumulative mortality was higher among patients

  5. A comparison of multiple esterases as biomarkers of organophosphate exposure and effect in two earthworm species.

    PubMed

    Henson-Ramsey, Heather; Schneider, Ashley; Stoskopf, Michael K

    2011-04-01

    Two different earthworm species, Eisenia fetida and Lumbricus terrestris, were exposed to 5 μg/cm(2) of malathion to evaluate their usefulness as sentinels of organophosphate exposure and to assess three different esterases, as biomarkers of malathion exposure and effect. Tissue xenobiotic burdens and esterase activity were determined for each species and each esterase in order to assess variability. E. fetida exhibited 4-fold less variability in tissue burdens than did L. terrestris and had less variable basal esterase activities. An attempt was made to correlate malathion and malaoxon tissue burdens with esterase activity post-exposure. There was no malaoxon present in the earthworm tissues. No significant correlations were determined by comparing acetylcholinesterase, butyrylcholinesterase, nor carboxylesterase activities with malathion burdens. PMID:21404045

  6. Feasibility of hair sampling to assess levels of organophosphate metabolites in rural areas of Sri Lanka.

    PubMed

    Knipe, D W; Jayasumana, C; Siribaddana, S; Priyadarshana, C; Pearson, M; Gunnell, D; Metcalfe, C; Tzatzarakis, M N; Tsatsakis, A M

    2016-05-01

    Measuring chronic pesticide exposure is important in order to investigate the associated health effects. Traditional biological samples (blood/urine) are difficult to collect, store and transport in large epidemiological studies in settings such as rural Asia. We assessed the acceptability of collecting hair samples from a rural Sri Lankan population and found that this method of data collection was feasible. We also assessed the level of non-specific metabolites (DAPS) of organophosphate pesticides in the hair samples. The median concentration (pg/mg) of each DAP was: diethyl phosphate: 83.3 (IQI 56.0, 209.4); diethyl thiophosphate: 34.7 (IQI 13.8, 147.9); diethyl dithiophosphate: 34.5 (IQI 23.4, 55.2); and dimethyl phosphate: 3 (IQI 3, 109.7). Total diethylphosphates were recovered in >80% of samples and were positively correlated with self-reported pesticide exposure.

  7. Effects of organophosphate pesticides and other drugs on subcortical mechanisms of visual integration.

    PubMed

    Revzin, A M

    1976-06-01

    Atropine, scopolamine, mevinphos, and eserine selectively block directional sensitivity of visual integrative neurones in the thalamus. Cholinergic drugs that do not penetrate the blood-brain barrier are without effect. The neurones studied are important links in reflex brain systems controlling visual attention and eye movements. The results suggest that any cholinergic drug that can get into the brain will disturb visual functions. Since the changes are qualitative and the system is reflex, the affected individual may be unaware of dysfunction. The resultant dangers to aerial applicator personnel are discussed, particularly with respect to atropine, which is necessary in the therapy of organophosphate and carbamate poisoning but is potentially harmful if self-administered for either pro-phylaxis or treatment.

  8. Phosphate-bound structure of an organophosphate-degrading enzyme from Agrobacterium radiobacter.

    PubMed

    Ely, Fernanda; Pedroso, Marcelo M; Gahan, Lawrence R; Ollis, David L; Guddat, Luke W; Schenk, Gerhard

    2012-01-01

    OpdA is a binuclear metalloenzyme that can hydrolyze organophosphate pesticides and nerve agents. In this study the crystal structure of the complex between OpdA and phosphate has been determined to 2.20 Å resolution. The structure shows the phosphate bound in a tripodal mode to the metal ions whereby two of the oxygen atoms of PO(4) are terminally bound to each metal ion and a third oxygen bridges the two metal ions, thus displacing the μOH in the active site. In silico modelling demonstrates that the phosphate moiety of a reaction product, e.g. diethyl phosphate, may bind in the same orientation, positioning the diethyl groups neatly into the substrate binding pocket close to the metal center. Thus, similar to the binuclear metallohydrolases urease and purple acid phosphatase the tripodal arrangement of PO(4) is interpreted in terms of a role of the μOH as a reaction nucleophile.

  9. Creation of recognition sites for organophosphate esters based on charge transfer and ligand exchange imprinting methods.

    PubMed

    Say, Ridvan

    2006-10-01

    This manuscript describes a method for the selective binding behavior of paraoxan and parathion compounds on surface imprinted polymers which were prepared using both charge transfer (CT) (methacryloyl-antipyrine, MAAP) and ligand-exchange (LE) (methacryloyl-antipyrine-gadalonium, MAAP-Gd) monomers. These polymers were prepared in the presence of azobisisobutyronitrile (AIBN) as an initiator and crosslinking EDMA and were imprinted with organophosphate esters. Influence of CT and LE imprinting on the creation of recognition sites toward paraoxan and parathion was determined applying adsorption isotherms. The effect of initial concentration of paraoxan and parathion, adsorption time and imprinting efficiency on adsorption selectivity for MIP-CT and MIP-LE was investigated. Association constant (K(ass)), number of accessible sites (Q(max)), relative selectivity coefficient (k') and binding ability were also evaluated.

  10. A rapid and inexpensive bioassay to evaluate the decontamination of organophosphates.

    PubMed

    Claborn, David M; Martin-Brown, Skylar A; Sagar, Sanjay Gupta; Durham, Paul

    2012-01-01

    An inexpensive and rapid bioassay using adult red flour beetles was developed for use in assessing the decontamination of environments containing organophosphates and related chemicals. A decontamination protocol was developed which demonstrated that 2 to 3 applications of 5% bleach solution were required to obtain nearly complete decontamination of malathion. The bioassay was also used to screen common household cleaners as potential decontaminating agents, but only 5% bleach was effective at improving survival of insects on steel plates treated with 25% malathion. A toxic degradation product (malaoxon) was detected using gas chromatography/mass spectrophotometry; this toxin affected the decontamination efficacy and resulted in continued toxicity to the beetles until subsequent decontaminations. The bioassay provides evidence to support the use of red flour beetles as a sensitive, less expensive method for determining safety levels of environments contaminated with malathion and other toxins, and may have application in the study of chemical warfare agents.

  11. Electing a candidate: a speculative history of the bacterial phylum OP10.

    PubMed

    Dunfield, Peter F; Tamas, Ivica; Lee, Kevin C; Morgan, Xochitl C; McDonald, Ian R; Stott, Matthew B

    2012-12-01

    In 1998, a cultivation-independent survey of the microbial community in Obsidian Pool, Yellowstone National Park, detected 12 new phyla within the Domain Bacteria. These were dubbed 'candidate divisions' OP1 to OP12. Since that time the OP10 candidate division has been commonly detected in various environments, usually as part of the rare biosphere, but occasionally as a predominant community component. Based on 16S rRNA gene phylogeny, OP10 comprises at least 12 class-level subdivisions. However, despite this broad ecological and evolutionary diversity, all OP10 bacteria have eluded cultivation until recently. In 2011, two reference species of OP10 were taxonomically validated, removing the phylum from its 'candidate' status. Construction of a highly resolved phylogeny based on 29 universally conserved genes verifies its standing as a unique bacterial phylum. In the following paper we summarize what is known and what is suspected about the newest described bacterial phylum, the Armatimonadetes. PMID:22497633

  12. Electing a candidate: a speculative history of the bacterial phylum OP10.

    PubMed

    Dunfield, Peter F; Tamas, Ivica; Lee, Kevin C; Morgan, Xochitl C; McDonald, Ian R; Stott, Matthew B

    2012-12-01

    In 1998, a cultivation-independent survey of the microbial community in Obsidian Pool, Yellowstone National Park, detected 12 new phyla within the Domain Bacteria. These were dubbed 'candidate divisions' OP1 to OP12. Since that time the OP10 candidate division has been commonly detected in various environments, usually as part of the rare biosphere, but occasionally as a predominant community component. Based on 16S rRNA gene phylogeny, OP10 comprises at least 12 class-level subdivisions. However, despite this broad ecological and evolutionary diversity, all OP10 bacteria have eluded cultivation until recently. In 2011, two reference species of OP10 were taxonomically validated, removing the phylum from its 'candidate' status. Construction of a highly resolved phylogeny based on 29 universally conserved genes verifies its standing as a unique bacterial phylum. In the following paper we summarize what is known and what is suspected about the newest described bacterial phylum, the Armatimonadetes.

  13. Respiratory Failure in Acute Organophosphorus Pesticide Self-Poisoning

    PubMed Central

    Eddleston, Michael; Mohamed, Fahim; Davies, James OJ; Eyer, Peter; Worek, Franz; Sheriff, MH Rezvi; Buckley, Nick A

    2006-01-01

    Background: Acute organophosphorus (OP) pesticide poisoning is a major clinical problem in the developing world. Textbooks ascribe most deaths to respiratory failure occurring in one of two distinct clinical syndromes - acute cholinergic respiratory failure or the intermediate syndrome. The delayed failure appears to be due to respiratory muscle weakness, but its pathophysiology is not yet clear. Aim: To describe the clinical patterns of OP-induced respiratory failure and to determine whether the two syndromes are clinically distinct. Design: Prospective cohort study of 376 patients with confirmed OP poisoning. Methods: Patients were observed throughout their admission to three Sri Lankan hospitals. Exposure was confirmed by butyrylcholinesterase and blood OP assays. Results: Ninety of 376 patients (24%) required intubation, 52 (58%) within 2 hrs of admission while unconscious with cholinergic features. Twenty-nine (32%) were well on admission but then required intubation after 24 hrs while conscious and without cholinergic features. These two syndromes were not clinically distinct and had much overlap. In particular, some patients who required intubation on arrival subsequently recovered conscious but could not be extubated, requiring ventilation for up to 6 days. Discussion: Respiratory failure did not occur as two discrete clinical syndromes within distinct time frames. Instead, the pattern of failure was variable and overlapped in some patients. There seemed to be two underlying mechanisms - an early acute mixed central and peripheral respiratory failure, and a late peripheral respiratory failure - rather than two defined clinical syndromes. PMID:16861715

  14. Monitoring Indoor Exposure to Organophosphate Flame Retardants: Hand Wipes and House Dust

    PubMed Central

    Hoffman, Kate; Garantziotis, Stavros; Birnbaum, Linda S.

    2014-01-01

    Background: Organophosphate flame retardants (PFRs) are becoming popular replacements for the phased-out polybrominated diphenyl ether (PBDE) mixtures, and they are now commonly detected in indoor environments. However, little is known about human exposure to PFRs because they cannot be easily measured in blood or serum. Objectives: To investigate relationships between the home environment and internal exposure, we assessed associations between two PFRs, tris(1,3-dichloropropyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP), in paired hand wipe and dust samples and concentrations of their metabolites in urine samples (n = 53). We also assessed short-term variation in urinary metabolite concentrations (n = 11 participants; n = 49 samples). Methods: Adult volunteers in North Carolina, USA, completed questionnaires and provided urine, hand wipe, and household dust samples. PFRs and PBDEs were measured in hand wipes and dust, and bis(1,3-dichloropropyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP), metabolites of TDCIPP and TPHP, were measured in urine. Results: TDCIPP and TPHP were detected frequently in hand wipes and dust (> 86.8%), with geometric mean concentrations exceeding those of PBDEs. Unlike PBDEs, dust TDCIPP and TPHP levels were not associated with hand wipes. However, hand wipe levels were associated with urinary metabolites. Participants with the highest hand wipe TPHP mass, for instance, had DPHP levels 2.42 times those of participants with the lowest levels (95% CI: 1.23, 4.77). Women had higher levels of DPHP, but not BDCIPP. BDCIPP and DPHP concentrations were moderately to strongly reliable over 5 consecutive days (intraclass correlation coefficients of 0.81 and 0.51, respectively). Conclusions: PFR exposures are widespread, and hand-to-mouth contact or dermal absorption may be important pathways of exposure. Citation: Hoffman K, Garantziotis S, Birnbaum LS, Stapleton HM. 2015. Monitoring indoor exposure to organophosphate flame retardants

  15. Sperm viability and gene expression in honey bee queens (Apis mellifera) following exposure to the neonicotinoid insecticide Imidacloprid and the organophosphate Acaricide Coumaphos

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Honey bee population declines are a global concern. Numerous factors appear to cause the decline including parasites, pathogens, malnutrition and pesticides. Residues of the organophosphate acaricide coumaphos and the neonicotinoid insecticide imidacloprid, widely used to combat Varroa mites and for...

  16. Is This Op-Amp Any Good?: Lab-Built Checker Removes All Doubt!

    ERIC Educational Resources Information Center

    Harman, Charles

    2007-01-01

    Electronics instructors and students find it very helpful to be able to check an operational amplifier at the proto-board stage. Most students lack the experience or knowledge that it takes to recognize whether an op-amp is operating normally or not. This article discusses a handy op-amp checker that allows one to check and/or test op-amps at the…

  17. GOME-2 total ozone columns from MetOp-A/MetOp-B and assimilation in the MACC system

    NASA Astrophysics Data System (ADS)

    Hao, N.; Koukouli, M. E.; Inness, A.; Valks, P.; Loyola, D. G.; Zimmer, W.; Balis, D. S.; Zyrichidou, I.; Van Roozendael, M.; Lerot, C.; Spurr, R. J. D.

    2014-09-01

    The two Global Ozone Monitoring Instrument (GOME-2) sensors operated in tandem are flying onboard EUMETSAT's (European Organisation for the Exploitation of Meteorological Satellites) MetOp-A and MetOp-B satellites, launched in October 2006 and September 2012 respectively. This paper presents the operational GOME-2/MetOp-A (GOME-2A) and GOME-2/MetOp-B (GOME-2B) total ozone products provided by the EUMETSAT Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). These products are generated using the latest version of the GOME Data Processor (GDP version 4.7). The enhancements in GDP 4.7, including the application of Brion-Daumont-Malicet ozone absorption cross sections, are presented here. On a global scale, GOME-2B has the same high accuracy as the corresponding GOME-2A products. There is an excellent agreement between the ozone total columns from the two sensors, with GOME-2B values slightly lower with a mean difference of only 0.55±0.29%. First global validation results for 6 months of GOME-2B total ozone using ground-based measurements show that on average the GOME-2B total ozone data obtained with GDP 4.7 are slightly higher than, both, Dobson observations by about 2.0±1.0% and Brewer observations by about 1.0±0.8%. It is concluded that the total ozone columns (TOCs) provided by GOME-2A and GOME-2B are consistent and may be used simultaneously without introducing systematic effects, which has been illustrated for the Antarctic ozone hole on 18 October 2013. GOME-2A total ozone data have been used operationally in the Copernicus atmospheric service project MACC-II (Monitoring Atmospheric Composition and Climate - Interim Implementation) near-real-time (NRT) system since October 2013. The magnitude of the bias correction needed for assimilating GOME-2A ozone is reduced (to about -6 DU in the global mean) when the GOME-2 ozone retrieval algorithm changed to GDP 4.7.

  18. Reflection-Based Deflection Routing in OPS Networks

    NASA Astrophysics Data System (ADS)

    Morita, Masayuki; Tode, Hideki; Murakami, Koso

    An important issue in the realization of optical packetswitched (OPS) networks is the resolution of packet contention caused by the lack of RAM-like optical buffering. Although an optical buffer using fiber delay lines (FDLs) has been proposed, its capacity is extremely limited. There have been several studies of this problem. One approach is deflection routing, which is widely used in electronic packet-switched networks or optical burst-switched (OBS) networks. However, in OPS networks, packet lengths are short, so that the speed requirement for route lookup is very stringent. If the network topology is geometric, such as a Manhattan Street Network (MSN), hop-by-hop routing can be implemented by simple optical logic devices without an electronic routing table. However, if the topology is not geometric, it is hard to implement deflection routing electronically or optically. Another approach is reflection routing, which is easy to implement but has a higher probability of packet loss than does deflection routing. In this paper, we propose a packet contention resolution scheme, reflection-based deflection routing, which is based on reflection routing and enables switching the reflected packet to an alternate path if its primary path remains congested. Our method alleviates the time limitation on setting an alternate path by making use of the packet reflection latency and also reduces the probability of packet loss. We evaluate the performance of the proposed method by simulation experiments and show its effectiveness.

  19. Nuclear localization of the dehydrin OpsDHN1 is determined by histidine-rich motif.

    PubMed

    Hernández-Sánchez, Itzell E; Maruri-López, Israel; Ferrando, Alejandro; Carbonell, Juan; Graether, Steffen P; Jiménez-Bremont, Juan F

    2015-01-01

    The cactus OpsDHN1 dehydrin belongs to a large family of disordered and highly hydrophilic proteins known as Late Embryogenesis Abundant (LEA) proteins, which accumulate during the late stages of embryogenesis and in response to abiotic stresses. Herein, we present the in vivo OpsDHN1 subcellular localization by N-terminal GFP translational fusion; our results revealed a cytoplasmic and nuclear localization of the GFP::OpsDHN1 protein in Nicotiana benthamiana epidermal cells. In addition, dimer assembly of OpsDHN1 in planta using a Bimolecular Fluorescence Complementation (BiFC) approach was demonstrated. In order to understand the in vivo role of the histidine-rich motif, the OpsDHN1-ΔHis version was produced and assayed for its subcellular localization and dimer capability by GFP fusion and BiFC assays, respectively. We found that deletion of the OpsDHN1 histidine-rich motif restricted its localization to cytoplasm, but did not affect dimer formation. In addition, the deletion of the S-segment in the OpsDHN1 protein affected its nuclear localization. Our data suggest that the deletion of histidine-rich motif and S-segment show similar effects, preventing OpsDHN1 from getting into the nucleus. Based on these results, the histidine-rich motif is proposed as a targeting element for OpsDHN1 nuclear localization. PMID:26442018

  20. Nuclear localization of the dehydrin OpsDHN1 is determined by histidine-rich motif

    PubMed Central

    Hernández-Sánchez, Itzell E.; Maruri-López, Israel; Ferrando, Alejandro; Carbonell, Juan; Graether, Steffen P.; Jiménez-Bremont, Juan F.

    2015-01-01

    The cactus OpsDHN1 dehydrin belongs to a large family of disordered and highly hydrophilic proteins known as Late Embryogenesis Abundant (LEA) proteins, which accumulate during the late stages of embryogenesis and in response to abiotic stresses. Herein, we present the in vivo OpsDHN1 subcellular localization by N-terminal GFP translational fusion; our results revealed a cytoplasmic and nuclear localization of the GFP::OpsDHN1 protein in Nicotiana benthamiana epidermal cells. In addition, dimer assembly of OpsDHN1 in planta using a Bimolecular Fluorescence Complementation (BiFC) approach was demonstrated. In order to understand the in vivo role of the histidine-rich motif, the OpsDHN1-ΔHis version was produced and assayed for its subcellular localization and dimer capability by GFP fusion and BiFC assays, respectively. We found that deletion of the OpsDHN1 histidine-rich motif restricted its localization to cytoplasm, but did not affect dimer formation. In addition, the deletion of the S-segment in the OpsDHN1 protein affected its nuclear localization. Our data suggest that the deletion of histidine-rich motif and S-segment show similar effects, preventing OpsDHN1 from getting into the nucleus. Based on these results, the histidine-rich motif is proposed as a targeting element for OpsDHN1 nuclear localization. PMID:26442018

  1. Analysis of the detection of organophosphate pesticides in aqueous solutions using polymer-coated single IDT sensors

    NASA Astrophysics Data System (ADS)

    McCarthy, Michael

    The single interdigital transducer (IDT) device was investigated as a micro-chemical sensor for the detection of organophosphates compounds in aqueous solutions. The compounds of interest are: parathion, parathion-methyl, and paraoxon. The polymers used as a partially-selective coating for the direct detection of these compounds are 2,2'-diallylbisphenol A- 1,1,3,3,5,5-hexamethyltrisiloxane (BPA-HMTS) and polyepichlorohydrin (PECH). BPA-HMTS is synthesized here at Marquette University. The measurement of interest for the single IDT is the change radiation resistance. The radiation resistance represents the energy stored in the propagating acoustic wave. As analyte absorbs into the polymer coating, changes in the film's properties will undergo resulting in a change in the radiation resistance i.e the acoustic wave properties. The film's properties changing include: added mass, viscoelastic properties, thickness, and dielectric properties. These properties will contribute to an overall change in the radiation resistance. A linear change in the radiation resistance is expected to occur for increasing concentrations of an organophosphate. The experimental results indicate that BPA-HMTS shows greater sensitivity towards the organophosphates than PECH. Both polymers showed greatest to lowest sensitivity to parathion, parathion-methyl, and paraoxon respectively. Thicker films tested for both polymers, 0.75μm thick, show a higher response due to a more pronounced effect of mass loading than the thinner films tested, 0.50μm. The response times for BPA-HMTS were much faster than for PECH. Both films showed fastest to slowest response time to paraoxon, parathion-methyl, and parathion respectively. The sensor is tested for reproducibility for the polymer BP-HMTS. A sensor array consisting of separately tested devices from this work as well as work done by a previous student is utilized to increase the selectivity of the three organophosphates. Radial plots are performed for

  2. Polymorphisms of paraoxonase (PON1) and their significance in clinical toxicology of organophosphates.

    PubMed

    Costa, Lucio G; Cole, Toby B; Furlong, Clement E

    2003-01-01

    Paraoxonase (PON1) is an HDL-associated enzyme capable of hydrolyzing multiple substrates, including several organophosphorous insecticides and nerve agents, oxidized lipids, and a number of drugs or pro-drugs. Several polymorphisms in the paraoxonase (PON1) gene have been described, which have been shown to affect either the catalytic efficiency of hydrolysis or the expression level of PON1. This review discusses the relevance of these polymorphisms for modulating sensitivity to organophosphorous compounds. Animal studies characterizing the PON1 polymorphisms have demonstrated the relevance of PON1 in modulating OP toxicity and have indicated the importance of an individual's PON1 status (i.e., genotype and phenotype taken together) rather than genotyping alone. Nevertheless, direct confirmation in humans of the relevance of PON1 status in conferring susceptibility to OP toxicity is still elusive. Recent studies examining the involvement of PON1 status in determining OP susceptibility of Gulf War veterans, sheep dippers, and individuals poisoned with chemical warfare agents represent a step in the right direction, but more studies are needed, with better documentation of both the level of exposure and the consequences of exposure.

  3. Developmental and polyamine metabolism alterations in Rhinella arenarum embryos exposed to the organophosphate chlorpyrifos.

    PubMed

    Sotomayor, Verónica; Lascano, Cecilia; de D'Angelo, Ana María Pechen; Venturino, Andrés

    2012-09-01

    Organophosphorus pesticides (OPs) are widely applied in the Alto Valle of Río Negro and Neuquén, Argentina, due to intensive fruit growing. Amphibians are particularly sensitive to environmental pollution, and OPs may transiently accumulate in ponds and channels of the region during their reproductive season. Organophosphorus pesticide exposure may alter amphibian embryonic development and the reproductive success of autochthonous species. In the present study, embryos of the common toad Rhinella arenarum were employed to assess developmental alterations and to study polyamine metabolism, which is essential to normal growth, as a possible target underlying the effects of the OP chlorpyrifos. As the duration of chlorpyrifos exposure increased and embryonic development progressed, the median lethal concentration (LC50) values decreased, and the percentage of malformed embryos increased. Developmental arrest was also observed and several morphological alterations were recorded, such as incomplete and abnormal closure of the neural tube, dorsal curvature of the caudal fin, reduction of body size and caudal fin length, atrophy, and edema. An early decrease in ornithine decarboxylase (ODC) activity and polyamine levels was also observed in embryos exposed to chlorpyrifos. The decrease in polyamine contents in tail bud embryos might be a consequence of the reduction in ODC activity. The alteration of polyamine metabolism occurred before embryonic growth was interrupted and embryonic malformations were observed and may be useful as a biomarker in environmental studies.

  4. Modeling and simulation of organophosphate-induced neurotoxicity: Prediction and validation by experimental studies.

    PubMed

    Greget, Renaud; Dadak, Selma; Barbier, Laure; Lauga, Fabien; Linossier-Pierre, Sandra; Pernot, Fabien; Legendre, Arnaud; Ambert, Nicolas; Bouteiller, Jean-Marie; Dorandeu, Frédéric; Bischoff, Serge; Baudry, Michel; Fagni, Laurent; Moussaoui, Saliha

    2016-05-01

    Exposure to organophosphorus (OP) compounds, either pesticides or chemical warfare agents, represents a major health problem. As potent irreversible inhibitors of cholinesterase, OP may induce seizures, as in status epilepticus, and occasionally brain lesions. Although these compounds are extremely toxic agents, the search for novel antidotes remains extremely limited. In silico modeling constitutes a useful tool to identify pharmacological targets and to develop efficient therapeutic strategies. In the present work, we developed a new in silico simulator in order to predict the neurotoxicity of irreversible inhibitors of acetyl- and/or butyrylcholinesterase (ChE) as well as the potential neuroprotection provided by antagonists of cholinergic muscarinic and glutamate N-methyl-d-aspartate (NMDA) receptors. The simulator reproduced firing of CA1 hippocampal neurons triggered by exposure to paraoxon (POX), as found in patch-clamp recordings in in vitro mouse hippocampal slices. In the case of POX intoxication, it predicted a preventing action of the muscarinic receptor antagonist atropine sulfate, as well as a synergistic action with the non-competitive NMDA receptor antagonist memantine. These in silico predictions relative to beneficial effects of atropine sulfate combined with memantine were recapitulated experimentally in an in vivo model of POX in adult male Swiss mice using electroencephalic (EEG) recordings. Thus, our simulator is a new powerful tool to identify protective therapeutic strategies against OP central effects, by screening various combinations of muscarinic and NMDA receptor antagonists. PMID:27108687

  5. Dynamic field sampling of airborne organophosphate triesters using solid-phase microextraction under equilibrium and non-equilibrium conditions.

    PubMed

    Isetun, Sindra; Nilsson, Ulrika

    2005-01-01

    A simple setup for dynamic air sampling using a solid-phase microextraction (SPME) device designed for use in the field was evaluated for organophosphate triester vapour under both equilibrium and non-equilibrium conditions. The effects of varying the applied airflows in the sampling device were evaluated in order to optimise the system with respect to the Reynolds number and magnitude of the boundary layer that developed near the surface. Further, the storage stability of the analytes was studied for both capped and uncapped 100-microm PDMS fibres. Organophosphate triesters are utilized on large scales as flame-retardants and/or plasticizers, for instance in upholstered furniture. In indoor working environments these compounds have become common components in the surrounding air. Measurements were performed in a recently furnished working environment and the concentration of tris(2-choropropyl) phosphate was found to be 7 microg m(-3).

  6. Comparative pulsation calculations with OP and OPAL opacities

    NASA Technical Reports Server (NTRS)

    Kanbur, Shashi M.; Simon, Norman R.

    1994-01-01

    Comparative linear nonadiabatic pulsation calculations are presented using the OPAL and Opacity Project opacities. The two sets of opacities include effects due to intermediate coupling and fine structure as well as new abundances. We used two mass luminosity (M-L) relations, one standard (BIT), and one employing substantial convective core overshoot (COV). The two sets of opacities cannot be differentiated on the basis of the stellar pulsation calculations presented here. The BIT relation can model the beat and bump Cepheids with masses between 4 and 7 solar mass, while if the overshoot relation is used, masses between 2 and 6 solar mass are required. In the RR Lyrae regime, we find the inferred masses of globular cluster RRd stars to be little influenced by the choice of OPAL or OP. Finally, the limited modeling we have done is not able to constrain the Cepheid M-L relation based upon period ratios observed in the beat and bump stars.

  7. Op GRITROCK ethics; the way of things to come?

    PubMed

    Clay, Katherine A; Henning, J D; Horne, S

    2016-06-01

    The Defence Medical Services (DMS) deployed on Op GRITROCK to Sierra Leone in support of the Ebola outbreak. This operation was the first large-scale DMS deployment since operations in Afghanistan ceased at the end of 2014. This type of operation revealed a number of ethical issues and challenges that the DMS had not faced for a long time. The ethical issues identified during the deployment are discussed in this article using the principalism approach of Beauchamp and Childress. Many of these issues were not identified prior to deployment, and troops were not adequately prepared. The article will outline the difficulties of using the principles of autonomy, beneficence, non-maleficence and justice during a public health emergency, and conclude with recommendations for ethical considerations that should be identified and mitigated against for future deployments to a public health emergency.

  8. Op GRITROCK ethics; the way of things to come?

    PubMed

    Clay, Katherine A; Henning, J D; Horne, S

    2016-06-01

    The Defence Medical Services (DMS) deployed on Op GRITROCK to Sierra Leone in support of the Ebola outbreak. This operation was the first large-scale DMS deployment since operations in Afghanistan ceased at the end of 2014. This type of operation revealed a number of ethical issues and challenges that the DMS had not faced for a long time. The ethical issues identified during the deployment are discussed in this article using the principalism approach of Beauchamp and Childress. Many of these issues were not identified prior to deployment, and troops were not adequately prepared. The article will outline the difficulties of using the principles of autonomy, beneficence, non-maleficence and justice during a public health emergency, and conclude with recommendations for ethical considerations that should be identified and mitigated against for future deployments to a public health emergency. PMID:27009319

  9. Toxicological and biochemical analysis of the susceptibility of sylvatic Triatoma infestans from the Andean Valley of Bolivia to organophosphate insecticide.

    PubMed

    Santo-Orihuela, Pablo Luis; Carvajal, Guillermo; Picollo, María Inés; Vassena, Claudia Viviana

    2013-09-01

    To increase our knowledge of the natural susceptibility of Triatoma infestans to an organophosphate insecticide, we performed toxicological and biochemical studies on three sylvatic populations from Bolivia and two populations from domestic dwellings from Bolivia and Argentina. Fifty-per-cent lethal doses (LD50) were determined based on the topical application of fenitrothion on first instar nymphs and mortality was assessed at 24 h. Both type of populations exhibited LD50ratios significantly higher than 1 with a range of the values (1.42-2.47); the maximum value were found in a sylvatic (-S) population, Veinte de Octubre-S. Samples were biochemically analysed using a glutathione S-transferase activity assay. The highest significant activity was obtained for Veinte de Octubre-S and the lowest activity was obtained for the reference population (102.69 and 54.23 pmol per minute per mg of protein respectively). Two out of the three sylvatic populations (Veinte de Octubre-S and Kirus Mayu-S) exhibited significantly higher glutathione S-transferase activity than that of the reference population. Based on this analysis of the natural susceptibility of this organism to organophosphate insecticides, continental and focal surveys of organophosphate susceptibility should be conducted to evaluate the evolution and distribution of this phenomenon.

  10. Acetylcholinesterase-Fc Fusion Protein (AChE-Fc): A Novel Potential Organophosphate Bioscavenger with Extended Plasma Half-Life.

    PubMed

    Noy-Porat, Tal; Cohen, Ofer; Ehrlich, Sharon; Epstein, Eyal; Alcalay, Ron; Mazor, Ohad

    2015-08-19

    Acetylcholinesterase (AChE) is the physiological target of organophosphate nerve agent compounds. Currently, the development of a formulation for prophylactic administration of cholinesterases as bioscavengers in established risk situations of exposure to nerve agents is the incentive for many efforts. While cholinesterase bioscavengers were found to be highly effective in conferring protection against nerve agent exposure in animal models, their therapeutic use is complicated by short circulatory residence time. To create a bioscavenger with prolonged plasma half-life, compatible with biotechnological production and purification, a chimeric recombinant molecule of HuAChE coupled to the Fc region of human IgG1 was designed. The novel fusion protein, expressed in cultured cells under optimized conditions, maintains its full enzymatic activity, at levels similar to those of the recombinant AChE enzyme. Thus, this novel fusion product retained its binding affinity toward BW284c5 and propidium, and its bioscavenging reactivity toward the organophosphate-AChE inhibitors sarin and VX. Furthermore, when administered to mice, AChE-Fc exhibits exceptional circulatory residence longevity (MRT of 6000 min), superior to any other known cholinesterase-based recombinant bioscavengers. Owing to its optimized pharmacokinetic performance, high reactivity toward nerve agents, and ease of production, AChE-Fc emerges as a promising next-generation organophosphate bioscavenger.

  11. Validation of Direct Analysis Real Time source/Time-of-Flight Mass Spectrometry for organophosphate quantitation on wafer surface.

    PubMed

    Hayeck, Nathalie; Ravier, Sylvain; Gemayel, Rachel; Gligorovski, Sasho; Poulet, Irène; Maalouly, Jacqueline; Wortham, Henri

    2015-11-01

    Microelectronic wafers are exposed to airborne molecular contamination (AMC) during the fabrication process of microelectronic components. The organophosphate compounds belonging to the dopant group are one of the most harmful groups. Once adsorbed on the wafer surface these compounds hardly desorb and could diffuse in the bulk of the wafer and invert the wafer from p-type to n-type. The presence of these compounds on wafer surface could have electrical effect on the microelectronic components. For these reasons, it is of importance to control the amount of these compounds on the surface of the wafer. As a result, a fast quantitative and qualitative analytical method, nondestructive for the wafers, is needed to be able to adjust the process and avoid the loss of an important quantity of processed wafers due to the contamination by organophosphate compounds. Here we developed and validated an analytical method for the determination of organic compounds adsorbed on the surface of microelectronic wafers using the Direct Analysis in Real Time-Time of Flight-Mass Spectrometry (DART-ToF-MS) system. Specifically, the developed methodology concerns the organophosphate group.

  12. Toxicological and biochemical analysis of the susceptibility of sylvatic Triatoma infestans from the Andean Valley of Bolivia to organophosphate insecticide

    PubMed Central

    Santo-Orihuela, Pablo Luis; Carvajal, Guillermo; Picollo, María Inés; Vassena, Claudia Viviana

    2013-01-01

    To increase our knowledge of the natural susceptibility of Triatoma infestans to an organophosphate insecticide, we performed toxicological and biochemical studies on three sylvatic populations from Bolivia and two populations from domestic dwellings from Bolivia and Argentina. Fifty-per-cent lethal doses (LD50) were determined based on the topical application of fenitrothion on first instar nymphs and mortality was assessed at 24 h. Both type of populations exhibited LD50ratios significantly higher than 1 with a range of the values (1.42-2.47); the maximum value were found in a sylvatic (-S) population, Veinte de Octubre-S. Samples were biochemically analysed using a glutathione S-transferase activity assay. The highest significant activity was obtained for Veinte de Octubre-S and the lowest activity was obtained for the reference population (102.69 and 54.23 pmol per minute per mg of protein respectively). Two out of the three sylvatic populations (Veinte de Octubre-S and Kirus Mayu-S) exhibited significantly higher glutathione S-transferase activity than that of the reference population. Based on this analysis of the natural susceptibility of this organism to organophosphate insecticides, continental and focal surveys of organophosphate susceptibility should be conducted to evaluate the evolution and distribution of this phenomenon. PMID:24037203

  13. One Bright Spot in the Current Job Crunch: Co-Op Ed.

    ERIC Educational Resources Information Center

    Weisbord, Anne

    1990-01-01

    Discusses how cooperative education (co-op) programs work, how they help career choices, and the value of the experience in job seeking. Claims the benefits of co-op programs are better than ever for students and employees alike. (ABL)

  14. Preparing for High Technology: Successful Co-op Strategies. Research and Development Series No. 263.

    ERIC Educational Resources Information Center

    Franchak, Stephen J.; Smith, O. H. Michael

    This document has been prepared to assist program administrators and practitioners in planning and implementing cooperative (co-op) programs in high technology occupational areas. Information focuses on the key elements, strategies, and procedures of successful co-op programs. The guide contains nine chapters and is based on a review of the…

  15. UTC(OP) based on LNE-SYRTE atomic fountain primary frequency standards

    NASA Astrophysics Data System (ADS)

    Rovera, G. D.; Bize, S.; Chupin, B.; Guéna, J.; Laurent, Ph; Rosenbusch, P.; Uhrich, P.; Abgrall, M.

    2016-06-01

    UTC(OP), the French national realization of the international coordinated universal time, was redesigned and rebuilt. The first step was the implementation in October 2012 of a new algorithm based on a H-maser and on atomic fountain data. Thanks to the new implementation, the stability of UTC(OP) was dramatically improved and UTC(OP) competes with the best time scales available today. Then the hardware generation and distribution of the UTC(OP) physical signals were replaced. Part of the new hardware is composed of commercial devices, but the key elements were specifically developed. One of them is a special switch that allows the UTC(OP) signals to be derived from one of two time scales, based on two different H-masers, which are generated simultaneously. This insures the continuity of the UTC(OP) signal even when a change of the reference H-maser is required. With the new hardware implementation, UTC(OP) is made available through three coherent signals: 100 MHz, 10 MHz and 1 PPS. For more than 3 years, UTC(OP) remained well below 10 ns close to UTC, with a difference even less than 5 ns if we except a short period around MJD 56650.

  16. 77 FR 27788 - Notice of Issuance of Final Determination Concerning Special Ops Flashlights and Sportsman...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-11

    ... night vision optics. The red light is used for low light illumination to preserve night vision equipment... of a Special Ops Flashlight, Sportsman Flashlight, and a light-emitting diode (LED) blank assembly... and government procurement of three items, the special ops flashlight, sportsman flashlight and...

  17. Detection of Organophosphate Flame Retardants in Furniture Foam and US House Dust

    PubMed Central

    Stapleton, Heather M.; Klosterhaus, Susan; Eagle, Sarah; Fuh, Jennifer; Meeker, John D.; Blum, Arlene; Webster, Thomas F.

    2009-01-01

    Restrictions on the use of polybrominated diphenyl ethers (PBDEs) have resulted in the increased use of alternate flame retardant chemicals to meet flammability standards. However, it has been difficult to determine which chemical formulations are currently being used in high volumes to meet flammability standards since the use of flame retardant formulations in consumer products is not transparent (i.e. not provided to customers). To investigate chemicals being used as replacements for PentaBDE in polyurethane foam, we analyzed foam samples from 26 different pieces of furniture purchased in the United States primarily between 2003 and 2009 using gas chromatography mass spectrometry. Samples included foam from couches, chairs, mattress pads, pillows, and, in one case, foam from a sound proofing system of a laboratory grade dust sieve. Fifteen of the foam samples contained the flame retardant tris(1,3-dichloro-2-propyl) phosphate (TDCPP; 1–5% by weight), four samples contained tris(1-chloro-2-propyl) phosphate (TCPP; 0.5 –2.2 % by weight), one sample contained brominated chemicals found in a new flame retardant mixture called Firemaster 550 (4.2% by weight), and one foam sample collected from a futon likely purchased prior to 2004 contained PentaBDE (0.5% by weight). Due to the high frequency of detection of the chlorinated phosphate compounds in furniture foam, we analyzed extracts from 50 house dust samples collected between 2002 and 2007 in the Boston, MA area for TDCPP, TCPP, and another high volume use organophosphate-based flame retardant used in foam, triphenylphosphate (TPP). Detection frequencies for TDCPP and TPP in the dust samples were >96% and were log normally distributed, similar to observations for PBDEs. TCPP was positively detected in dust in only 24% of the samples, but detection was significantly limited by a co-elution problem. The geometric mean concentrations for TCPP, TDCPP and TPP in house dust were 570, 1890, and 7360 ng/g, respectively

  18. Total column water vapour measurements from GOME-2 MetOp-A and MetOp-B

    NASA Astrophysics Data System (ADS)

    Grossi, M.; Valks, P.; Loyola, D.; Aberle, B.; Slijkhuis, S.; Wagner, T.; Beirle, S.; Lang, R.

    2015-03-01

    Knowledge of the total column water vapour (TCWV) global distribution is fundamental for climate analysis and weather monitoring. In this work, we present the retrieval algorithm used to derive the operational TCWV from the GOME-2 sensors aboard EUMETSAT's MetOp-A and MetOp-B satellites and perform an extensive inter-comparison in order to evaluate their consistency and temporal stability. For the analysis, the GOME-2 data sets are generated by DLR in the framework of the EUMETSAT O3M-SAF project using the GOME Data Processor (GDP) version 4.7. The retrieval algorithm is based on a classical Differential Optical Absorption Spectroscopy (DOAS) method and combines a H2O and O2 retrieval for the computation of the trace gas vertical column density. We introduce a further enhancement in the quality of the H2O total column by optimizing the cloud screening and developing an empirical correction in order to eliminate the instrument scan angle dependencies. The overall consistency between measurements from the newer GOME-2 instrument on board of the MetOp-B platform and the GOME-2/MetOp-A data is evaluated in the overlap period (December 2012-June 2014). Furthermore, we compare GOME-2 results with independent TCWV data from the ECMWF ERA-Interim reanalysis, with SSMIS satellite measurements during the full period January 2007-June 2014 and against the combined SSM/I + MERIS satellite data set developed in the framework of the ESA DUE GlobVapour project (January 2007-December 2008). Global mean biases as small as ±0.035 g cm-2 are found between GOME-2A and all other data sets. The combined SSM/I-MERIS sample and the ECMWF ERA-Interim data set are typically drier than the GOME-2 retrievals, while on average GOME-2 data overestimate the SSMIS measurements by only 0.006 g cm-2. However, the size of these biases is seasonally dependent. Monthly average differences can be as large as 0.1 g cm-2, based on the analysis against SSMIS measurements, which include only data over

  19. Emerging OP354-Like P[8] Rotaviruses Have Rapidly Dispersed from Asia to Other Continents.

    PubMed

    Zeller, Mark; Heylen, Elisabeth; Damanka, Susan; Pietsch, Corinna; Donato, Celeste; Tamura, Tsutomu; Kulkarni, Ruta; Arora, Ritu; Cunliffe, Nigel; Maunula, Leena; Potgieter, Christiaan; Tamim, Sana; Coster, Sarah De; Zhirakovskaya, Elena; Bdour, Salwa; O'Shea, Helen; Kirkwood, Carl D; Seheri, Mapaseka; Nyaga, Martin Monene; Mphahlele, Jeffrey; Chitambar, Shobha D; Dagan, Ron; Armah, George; Tikunova, Nina; Van Ranst, Marc; Matthijnssens, Jelle

    2015-08-01

    The majority of human group A rotaviruses possess the P[8] VP4 genotype. Recently, a genetically distinct subtype of the P[8] genotype, also known as OP354-like P[8] or lineage P[8]-4, emerged in several countries. However, it is unclear for how long the OP354-like P[8] gene has been circulating in humans and how it has spread. In a global collaborative effort 98 (near-)complete OP354-like P[8] VP4 sequences were obtained and used for phylogeographic analysis to determine the viral migration patterns. During the sampling period, 1988-2012, we found that South and East Asia acted as a source from which strains with the OP354-like P[8] gene were seeded to Africa, Europe, and North America. The time to the most recent common ancestor (TMRCA) of all OP354-like P[8] genes was estimated at 1987. However, most OP354-like P[8] strains were found in three main clusters with TMRCAs estimated between 1996 and 2001. The VP7 gene segment of OP354-like P[8] strains showed evidence of frequent reassortment, even in localized epidemics, suggesting that OP354-like P[8] genes behave in a similar manner on the evolutionary level as other P[8] subtypes. The results of this study suggest that OP354-like P[8] strains have been able to disperse globally in a relatively short time period. This, in combination with a relatively large genetic distance to other P[8] subtypes, might result in a lower vaccine effectiveness, underscoring the need for a continued surveillance of OP354-like P[8] strains, especially in countries where rotavirus vaccination programs are in place.

  20. Size-dependent atmospheric deposition and inhalation exposure of particle-bound organophosphate flame retardants.

    PubMed

    Luo, Pei; Bao, Lian-Jun; Guo, Ying; Li, Shao-Meng; Zeng, Eddy Y

    2016-01-15

    Atmospheric size-fractionated particles were collected at different heights in an e-waste recycling zone (QY) and urban Guangzhou (GZ), China and analyzed for organophosphate flame retardants (OPFRs). The total air concentrations of eight OPFRs were 130±130 and 138±127 ng m(-3) in QY and GZ, respectively. Compositional profiles of chlorinated OPFRs were different between QY and GZ, but the size distribution patterns of all OPFRs were not significantly different at different heights. Estimated atmospheric deposition fluxes of OPFRs were 51±67 and 55±13 μg m(-2) d(-1) in QY and GZ, respectively, and the coarse particles (Dp>1.8 μm) dominated both the dry and wet deposition fluxes. Moreover, not all particle-bound OPFRs were inhalable and deposited in the human respiratory tract. The calculated inhalation doses of OPFRs were much lower than the reference doses, suggesting that potential health risk due to inhalation exposure to particle-bound OPFRs in the e-waste recycling zone and urban site was low.

  1. Effects of primary metabolites of organophosphate flame retardants on transcriptional activity via human nuclear receptors.

    PubMed

    Kojima, Hiroyuki; Takeuchi, Shinji; Van den Eede, Nele; Covaci, Adrian

    2016-03-14

    Organophosphate flame retardants (OPFRs) have been used in a wide variety of applications and detected in several environmental matrices, including indoor air and dust. Continuous human exposure to these chemicals is of growing concern. In this study, the agonistic and/or antagonistic activities of 12 primary OPFR-metabolites against ten human nuclear receptors were examined using cell-based transcriptional assays, and compared to those of their parent compounds. As a result, 3-hydroxylphenyl diphenyl phosphate and 4-hydroxylphenyl diphenyl phosphate showed more potent estrogen receptor α (ERα) and ERβ agonistic activity than did their parent, triphenyl phosphate (TPHP). In addition, these hydroxylated TPHP-metabolites also showed ERβ antagonistic activity at higher concentrations and exhibited pregnane X receptor (PXR) agonistic activity as well as androgen receptor (AR) and glucocorticoid receptor (GR) antagonistic activities at similar levels to those of TPHP. Bis(2-butoxyethyl) 3'-hydroxy-2-butoxyethyl phosphate and 2-hydroxyethyl bis(2-butoxyethyl) phosphate act as PXR agonists at similar levels to their parent, tris(2-butoxyethyl) phosphate. On the other hand, seven diester OPFR-metabolites and 1-hydroxy-2-propyl bis(1-chloro-2-propyl) phosphate did not show any receptor activity. Taken together, these results suggest that hydroxylated TPHP-metabolites show increased estrogenicity compared to the parent compound, whereas the diester OPFR-metabolites may have limited nuclear receptor activity compared to their parent triester OPFRs.

  2. Airborne organophosphate pesticides drift in Mediterranean climate: The importance of secondary drift

    NASA Astrophysics Data System (ADS)

    Zivan, Ohad; Segal-Rosenheimer, Michal; Dubowski, Yael

    2016-02-01

    Pesticide application is a short-term air-pollution episode with near and far field effects due to atmospheric drift. In order to better evaluate resulting air concentrations in nearby communities following pesticide application, measurements of airborne pesticides were conducted at ∼70 m from field edge. This was done following three different application events of the organophosphate pesticide Chlorpyrifos in a persimmon orchard. Complementary information on larger spatial scale was obtained using CALPUFF modeling in which application and meteorological data was used to better evaluate dispersion patterns. Measurements indicated high airborne concentrations during application hours (few μg m-3 for 8 h average), which dropped to tens of ng m-3 in the following days. Measured atmospheric concentrations show that secondary drift (i.e., post-application drift) involves significant loads of pesticides and hence should not be ignored in exposure considerations. Furthermore, CALPUFF modeling revealed the complex dispersion pattern when weak winds prevailed, and showed that during the 24 h after application air concentrations reached levels above the hourly Texas effect screening level (0.1 μg m-3). Interestingly, weak winds on the night after application resulted in a secondary peak in measured and modeled air concentrations. Long exposure time (when secondary drift is considered) and concentrations measured following such common air-assisted orchard application, suggest pesticide drift may have health repercussions that are currently unknown, and emphasize the need for further epidemiological studies.

  3. Sulfhydryl-specific PEGylation of phosphotriesterase cysteine mutants for organophosphate detoxification.

    PubMed

    Daffu, Gurdip K; Lopez, Patricia; Katz, Francine; Vinogradov, Michael; Zhan, Chang-Guo; Landry, Donald W; Macdonald, Joanne

    2015-11-01

    The catalytic bioscavenger phosphotriesterase (PTE) is experimentally an effective antidote for organophosphate poisoning. We are interested in the molecular engineering of this enzyme to confer additional functionality, such as improved in vivo longevity. To this aim, we developed PTE cysteine mutants with free sulfhydryls to allow macromolecular attachments to the protein. A library of PTE cysteine mutants were assessed for efficiency in hydrolysing the toxic pesticide metabolite paraoxon, and screened for attachment with a sulfhydryl-reactive small molecule, fluorescein 5-maleimide (F5M), to examine cysteine availability. We established that the newly incorporated cysteines were readily available for labelling, with R90C, E116C and S291C displaying the highest affinity for binding with F5M. Next, we screened for efficiency in attaching a large macromolecule, a 30 000 Da polyethylene glycol (PEG) molecule. Using a solid-phase PEGylation strategy, we found the E116C mutant to be the best single-mutant candidate for attachment with PEG30. Kinetic activity of PEGylated E116C, with paraoxon as substrate, displayed activity approaching that of the unPEGylated wild-type. Our findings demonstrate, for the first time, an efficient cysteine mutation and subsequent method for sulfhydryl-specific macromolecule attachment to PTE.

  4. Organophosphate flame retardants in indoor dust from Egypt: implications for human exposure.

    PubMed

    Abdallah, Mohamed Abou-Elwafa; Covaci, Adrian

    2014-05-01

    Organophosphate flame retardants (PFRs) have been proposed as alternatives for the phased out PBDE formulations. However, there exists no information on indoor dust contamination with PFRs in Africa. In this study, we report--for the first time--on levels and profiles of PFRs in dust samples from Egyptian houses (n = 20), offices (n = 20), cars (n = 20), and public microenvironments (PMEs; n = 11). Results revealed that PFR levels in Egyptian indoor dust are among the lowest reported worldwide. This may be attributed to less strict fire-safety standards and lack of regulatory actions against PBDEs. Triphenylphosphate was the only PFR detected in all samples with highest average concentration (386 ng g(-1)). While tris-2-chloroethyl phosphate, tris(1-chloro-2-propyl)phosphate and tris-1,3-dichloropropylphosphate showed higher detection frequency (DF = 69%, 57%, and 56%; average = 233, 229, and 144 ng g(-1), respectively), tri(2-butoxyexthyl)phosphate (37%; 294 ng g(-1)) displayed the second highest average concentration. Statistical analysis revealed significantly (P < 0.05) higher concentrations of ΣPFRs in cars (average = 1011 ng g(-1)) and PMEs (2167 ng g(-1)) than in houses (310 ng g(-1)) and offices (450 ng g(-1)). Estimated exposures of adults and toddlers to PFRs via dust ingestion were much lower than the reported reference doses, indicating no immediate health risk to the Egyptian population.

  5. Distribution of Organophosphate Esters between the Gas and Particle Phase-Model Predictions vs Measured Data.

    PubMed

    Sühring, Roxana; Wolschke, Hendrik; Diamond, Miriam L; Jantunen, Liisa M; Scheringer, Martin

    2016-07-01

    Gas-particle partitioning is one of the key factors that affect the environmental fate of semivolatile organic chemicals. Many organophosphate esters (OPEs) have been reported to primarily partition to particles in the atmosphere. However, because of the wide range of their physicochemical properties, it is unlikely that OPEs are mainly in the particle phase "as a class". We compared gas-particle partitioning predictions for 32 OPEs made by the commonly used OECD POV and LRTP Screening Tool ("the Tool") with the partitioning models of Junge-Pankow (J-P) and Harner-Bidleman (H-B), as well as recently measured data on OPE gas-particle partitioning. The results indicate that half of the tested OPEs partition into the gas phase. Partitioning into the gas phase seems to be determined by an octanol-air partition coefficient (log KOA) < 10 and a subcooled liquid vapor pressure (log PL) > -5 (PL in Pa), as well as the total suspended particle concentration (TSP) in the sampling area. The uncertainty of the physicochemical property data of the OPEs did not change this estimate. Furthermore, the predictions by the Tool, J-P- and H-B-models agreed with recently measured OPE gas-particle partitioning. PMID:27144674

  6. Biochemical, metabolic, and behavioural responses and recovery of Daphnia magna after exposure to an organophosphate.

    PubMed

    Duquesne, Sabine; Küster, Eberhard

    2010-03-01

    The responses of various suborganismal and organismal endpoints of Daphnia magna to pulse exposure to sublethal levels of the organophosphate paraoxon-methyl were compared. The changes and recovery of biochemical, metabolic, and behavioural variables, as well as physiological responses, were observed. The cholinesterase (ChE), filtration, and swimming activities were all affected in a concentration-dependent manner, and these effects reached significance at concentrations of 1.0, 1.5, and 0.7 microg L(-1), respectively. The levels of these variables recovered significantly after detoxification for 24h in clean medium. ChE and swimming activities were affected significantly by lower concentrations of paraoxon-methyl than filtration activity, which had the same threshold as the physiological responses ((15)N abundance and body size). This study showed that among the parameters studied, swimming activity was the most sensitive, whereas changes in filtration activity had the most significant physiological consequences, and were therefore important in terms of effects propagation to the population level. PMID:20031215

  7. From Clothing to Laundry Water: Investigating the Fate of Phthalates, Brominated Flame Retardants, and Organophosphate Esters.

    PubMed

    Saini, Amandeep; Thaysen, Clara; Jantunen, Liisa; McQueen, Rachel H; Diamond, Miriam L

    2016-09-01

    The accumulation of phthalate esters, brominated flame retardants (BFRs) and organophosphate esters (OPEs) by clothing from indoor air and transfer via laundering to outdoors were investigated. Over 30 days cotton and polyester fabrics accumulated 3475 and 1950 ng/dm(2) ∑5phthalates, 65 and 78 ng/dm(2) ∑10BFRs, and 1200 and 310 ng/dm(2) ∑8OPEs, respectively. Planar surface area concentrations of OPEs and low molecular weight phthalates were significantly greater in cotton than polyester and similar for BFRs and high molecular weight phthalates. This difference was significantly and inversely correlated with KOW, suggesting greater sorption of polar compounds to polar cotton. Chemical release from cotton and polyester to laundry water was >80% of aliphatic OPEs (log KOW < 4), < 50% of OPEs with an aromatic structure, 50-100% of low molecular weight phthalates (log KOW 4-6), and < detection-35% of higher molecular weight phthalates (log KOW > 8) and BFRs (log KOW > 6). These results support the hypothesis that clothing acts an efficient conveyer of soluble semivolatile organic compounds (SVOCs) from indoors to outdoors through accumulation from air and then release during laundering. Clothes drying could as well contribute to the release of chemicals emitted by electric dryers. The results also have implications for dermal exposure. PMID:27507188

  8. Detection and identification of immobilized low-volatility organophosphates by desorption ionization mass spectrometry

    NASA Astrophysics Data System (ADS)

    Hagan, Nathan A.; Cornish, Timothy J.; Pilato, Robert S.; van Houten, Kelly A.; Antoine, Miquel D.; Lippa, Timothy P.; Becknell, Alan F.; Demirev, Plamen A.

    2008-12-01

    Two desorption ionization mass spectrometry (MS) techniques - ultraviolet laser desorption/ionization (LDI) and desorption electrospray ionization (DESI) - have been used to detect and identify low-volatility organophosphates when deposited on surfaces or loaded into the pore volume of porous inorganic or polymeric organic powders. The insecticides malathion and dicrotophos were chosen for this study as simulants of low vapor pressure chemical warfare agents which are inherently difficult to detect directly by traditional methods. Both liquid and powdered forms of either insecticide were readily detected by LDI or DESI MS. LDI MS was performed on a miniaturized home-built time-of-flight (TOF) mass spectrometer and a commercial TOF/TOF instrument. For DESI MS, a home-built ion source was interfaced to a commercial quadrupole ion trap. In LDI, intact molecular ion signatures could be acquired by using an appropriate cationizing agent and powder additive in positive ion mode. Tandem MS was used to confirm the identity of each analyte based on the observed characteristic fragmentation pattern. In DESI, less than 100 pg of the liquid insecticides spotted on clean surfaces were detected, while detection limits for the powder-loaded preparations were lower than 1 [mu]g. The effects of sample surface, salt additives, nanoparticle admixtures, and analyte solubility on the LDI and DESI MS sensitivity have been investigated as well.

  9. Persistence of selected organophosphate and carbamate insecticides in waters from a coastal watershed.

    PubMed

    Bondarenko, Svetlana; Gan, Jianying; Haver, Darren L; Kabashima, John N

    2004-11-01

    Organophosphate and carbamate compounds are among the most widely used pesticides. Contamination of surface water by these compounds is of concern because of potential toxicity to aquatic organisms, especially those at lower trophic levels. In this study we evaluated the persistence of diazinon, chlorpyrifos, malathion, and carbaryl in waters from various sites in the Newport Bay-San Diego Creek watershed in southern California (USA). The persistence of diazinon and chlorpyrifos was much longer than that of malathion or carbaryl and was further prolonged in seawater. Microbial degradation contributed significantly to the dissipation of diazinon and chlorpyrifos in freshwater, but was inhibited in seawater, leading to increased persistence. In contrast, degradation of malathion and carbaryl was rapid and primarily abiotic. A greater temperature dependence was observed for carbaryl degradation in all waters and for diazinon degradation in freshwater. The interactions of pesticide persistence with water location, temperature, and type of pesticides suggest that site- and compound-specific information is needed when evaluating the overall ecotoxicological risks of pesticide pollution in a watershed. Because the persistence of diazinon and chlorpyrifos may increase significantly in seawater, mitigation should occur before the pesticides reach seawater. The relatively short persistence of these compounds in freshwater suggests that practices aimed at extending residence time (e.g., diversion to wetlands) may effectively reduce pesticide output to downstream water bodies.

  10. Hair and Nails as Noninvasive Biomarkers of Human Exposure to Brominated and Organophosphate Flame Retardants.

    PubMed

    Liu, Liang-Ying; He, Ka; Hites, Ronald A; Salamova, Amina

    2016-03-15

    After the phase-out of polybrominated diphenyl ethers (PBDEs), the use of alternative flame retardants (AFRs), such as FireMaster 550, and of organophosphate esters (OPEs) has increased. However, little is known about human exposure to these chemicals. This lack of biomonitoring studies is partially due to the absence of reliable noninvasive biomarkers of exposure. Human hair and nails can provide integrated exposure measurements, and as such, these matrices can potentially be used as noninvasive biomarkers of exposure to these flame retardants. Paired human hair, fingernail, toenail, and serum samples obtained from 50 adult participants recruited at Indiana University Bloomington campus were analyzed by gas chromatographic mass spectrometry for 36 PBDEs, 9 AFRs, and 12 OPEs. BDE-47, BDE-99, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), di(2-ethylhexyl) tetrabromophthalate (TBPH), tris(1,3-dichloro-2-propyl)phosphate (TDCIPP), and triphenyl phosphate (TPHP) were the most abundant compounds detected in almost all hair, fingernail, and toenail samples. The concentrations followed the order OPEs > TBB+TBPH > Σpenta-BDE. PBDE levels in the hair and nail samples were significantly correlated with their levels in serum (P < 0.05), suggesting that human hair and nails can be used as biomarkers to assess human exposure to PBDEs. PMID:26926265

  11. Organophosphate ester flame retardants and plasticizers in human placenta in Eastern China.

    PubMed

    Ding, Jinjian; Xu, Zemin; Huang, Wei; Feng, Limin; Yang, Fangxing

    2016-06-01

    Organophosphate esters (OPEs) have been widely used in various products as alternatives to brominated flame retardants. Although widespread OPE exposure is expected in humans, the accumulation of OPEs has seldom been studied in the human body. In this study, 12 OPE analogs were analyzed in 50 human placentas collected in Eastern China. The concentrations of the 9 most frequently detected OPEs (Σ9OPEs) ranged from 34.4 to 862ng/g lipid weight (lw), with a median of 301ng/g lw. Tri(2-chloroethyl) phosphate (TCEP) was identified as the most abundant analog, with a median concentration of 142ng/g lw, followed by tributoxyethyl phosphate (TBEP) and triphenyl phosphate (TPhP). Statistical analysis showed no analog of OPEs or Σ9OPEs was positively correlated with the lipid content of the placentas. There were no correlations observed between the OPE concentrations and maternal characteristics. Food consumption habits exhibited weak effects on OPE levels in the placentas. Further investigation is required to determine the effects of OPEs on fetuses due to the expected increase in maternal exposure to these esters. PMID:26950635

  12. High Exposure to Organophosphate Flame Retardants in Infants: Associations with Baby Products.

    PubMed

    Hoffman, Kate; Butt, Craig M; Chen, Albert; Limkakeng, Alexander T; Stapleton, Heather M

    2015-12-15

    Infant products containing polyurethane foam are commonly treated with organophosphate flame retardants (PFRs), including tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and triphenyl phosphate (TPHP). Infants may have greater exposure due to greater contact with these products, yet little is known about levels of exposure or the factors contributing to higher exposure. We recruited children age 2-18 months from North Carolina to investigate PFR exposure (n = 43; recruited 2014-2015). Parents provided information on potential sources and modifiers of exposure, and reported whether they owned common infant products. We measured five PFR metabolites in urine samples collected from children. TDCIPP and TPHP metabolites (bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP)) were most commonly detected (>93% detect). Other metabolites were detected infrequently (<35% detect). Although we did not observe a clear age trend for infants, BDCIPP levels were substantially higher than those reported for adults (geometric mean = 7.3 ng/mL). The number of infant products owned was strongly associated with BDCIPP; children with >16 products had BDCIPP levels that were 6.8 times those with <13 (p = 0.02). Infants attending daycare centers also had higher BDCIPP levels (3.7 times those of others; p = 0.07), suggesting time spent in this microenvironment contributes to higher exposure. In contrast, DPHP levels were not related to products owned, time in different microenvironments, or behavior. PMID:26551726

  13. Presence and select determinants of organophosphate flame retardants in public swimming pools.

    PubMed

    Teo, Tiffany L L; Coleman, Heather M; Khan, Stuart J

    2016-11-01

    The occurrence of five organophosphate flame retardants (PFRs) consisting of tributyl phosphate (TNBP), tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCIPP), tris(1.3-dichloro-2-propyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP) in swimming pools were investigated. Fifteen chlorinated public swimming pools were sampled, including indoor pools, outdoor pools and spa pools. The analyses were carried out using isotope dilution gas chromatography tandem mass spectrometry. All five PFRs were detected in swimming pool waters with concentrations ranging from 5-27ng/L (TNBP), 7-293ng/L (TCEP), 62-1180ng/L (TCIPP), 10-670ng/L (TDCIPP) and 8-132ng/L (TPHP). The concentrations of PFRs were generally higher in indoor swimming pools compared to outdoor swimming pools. In municipal water supplies, used to fill the swimming pools in three of the sampling locations, the five PFRs were all below the limit of quantifications, eliminating this as the source. Potential leaching of PFRs from commonly used swimming equipment, including newly purchased kickboards and swimsuits was investigated. These experiments revealed that PFRs leached from swimsuits, and may be a source of PFRs in swimming pools. A quantitative risk assessment revealed that the health risk to PFRs via swimming pools was generally low and below commonly applied health risk benchmarks.

  14. Phosphate-solubility and phosphatase activity in Gangetic alluvial soil as influenced by organophosphate insecticide residues.

    PubMed

    Majumder, Shyam Prasad; Das, Amal Chandra

    2016-04-01

    An experiment was conducted under laboratory conditions to investigate the effect of four organophosphate insecticides, viz. monocrotophos, profenophos, quinalphos and triazophos at their field application rates (0.75, 1.0, 0.5 and 0.6 kg a.i.ha(-1), respectively), on the growth and activities of phosphate solubilizing microorganisms in relation to availability of insoluble phosphates in the Gangetic alluvial soil of West Bengal, India. The proliferation of phosphate solubilizing microorganisms was highly induced with profenophos (38.3%), while monocrotophos exerted maximum stimulation (20.8%) towards the solubility of insoluble phosphates in soil. The phosphatase activities of the soil (both acid phosphatase and alkaline phosphatase) were significantly increased due to the incorporation of the insecticides in general, and the augmentation was more pronounced with quinalphos (43.1%) followed by profenophos (27.6%) for acid phosphatase, and with monocrotophos (25.2%) followed by profenophos (16.1%) for alkaline phosphatase activity in soil. The total phosphorus was highly retained by triazophos (19.9%) followed by monocrotophos (16.5%), while incorporation of triazophos and quinalphos manifested greater availability of water soluble phosphorus in soil.

  15. Occurrence and dry deposition of organophosphate esters in atmospheric particles over the northern South China Sea.

    PubMed

    Lai, Senchao; Xie, Zhiyong; Song, Tianli; Tang, Jianhui; Zhang, Yingyi; Mi, Wenying; Peng, Jinhu; Zhao, Yan; Zou, Shichun; Ebinghaus, Ralf

    2015-05-01

    Nine organophosphate esters (OPEs) in airborne particles were measured during a cruise campaign over the northern South China Sea (SCS) from September to October 2013. The concentration of the total OPEs (∑OPEs) was 47.1-160.9 pg m(-3), which are lower than previous measurements in marine atmosphere environments. Higher OPE concentrations were observed in terrestrially influenced samples, suggesting that OPE concentrations were significantly influenced by air mass transport. Chlorinated OPEs were the dominant OPEs, accounting for 65.8-83.7% of the ∑OPEs. Tris-(2-chloroethyl) phosphate (TCEP) was the predominant OPE compound in the samples (45.0±12.1%), followed by tris-(1-chloro-2-propyl) phosphates (TCPPs) (28.8±8.9%). Dry particle-bound deposition fluxes ranged from 8.2 to 27.8 ng m(-2) d(-1) for the ∑OPEs. Moreover, the dry deposition input of the ∑OPEs was estimated to be 4.98 ton y(-1) in 2013 in a vast area of northern SCS. About half of the input was found to relate to air masses originating from China.

  16. Phosphate-solubility and phosphatase activity in Gangetic alluvial soil as influenced by organophosphate insecticide residues.

    PubMed

    Majumder, Shyam Prasad; Das, Amal Chandra

    2016-04-01

    An experiment was conducted under laboratory conditions to investigate the effect of four organophosphate insecticides, viz. monocrotophos, profenophos, quinalphos and triazophos at their field application rates (0.75, 1.0, 0.5 and 0.6 kg a.i.ha(-1), respectively), on the growth and activities of phosphate solubilizing microorganisms in relation to availability of insoluble phosphates in the Gangetic alluvial soil of West Bengal, India. The proliferation of phosphate solubilizing microorganisms was highly induced with profenophos (38.3%), while monocrotophos exerted maximum stimulation (20.8%) towards the solubility of insoluble phosphates in soil. The phosphatase activities of the soil (both acid phosphatase and alkaline phosphatase) were significantly increased due to the incorporation of the insecticides in general, and the augmentation was more pronounced with quinalphos (43.1%) followed by profenophos (27.6%) for acid phosphatase, and with monocrotophos (25.2%) followed by profenophos (16.1%) for alkaline phosphatase activity in soil. The total phosphorus was highly retained by triazophos (19.9%) followed by monocrotophos (16.5%), while incorporation of triazophos and quinalphos manifested greater availability of water soluble phosphorus in soil. PMID:26720809

  17. Rice ingestion is a major pathway for human exposure to organophosphate flame retardants (OPFRs) in China.

    PubMed

    Zhang, Xingli; Zou, Wei; Mu, Li; Chen, Yuming; Ren, Chaoxiu; Hu, Xiangang; Zhou, Qixing

    2016-11-15

    Although organophosphate flame retardants (OPFRs) have been shown to accumulate in abiotic and biotic environmental compartments, data about OPFRs concentrations in various foods are limited and are none in humans through diets. In this work, the concentrations of 6 typical OPFRs were investigated in 50 rice samples, 75 commonly consumed foods and 45 human hair samples from China. The dietary intakes of OPFRs for adult people via food ingestion were estimated. The concentrations of ΣOPFRs in foods ranged from 0.004ng/g to 287ng/g. OPFRs were detected in 53.3% of the human hair samples. The highest OPFRs concentrations were found in rice and vegetables. Tri(2-chloroethyl)phosphate(TCEP), tris(2-chloroisopropyl)phosphate(TCIPP), and tri(2-ethyltexyl)phosphate(TEHP) were predominant in all food samples. OPFRs concentrations in foods were not significantly affected by the packaging materials. The mean dietary intakes of ΣOPFRs for adult males and females were 539 and 601ng/kg body weight/day, respectively. The greatest contribution to these values is from rice, accounting for approximately 60% of the total intake, particularly from rice protein. Rice ingestion was considered a potential major pathway for human exposure to OPFRs, and regional differences in the levels of OPFRs in foods and dietary differences should be given more attention in the future. PMID:27484948

  18. Baseline Susceptibility to Pyrethroid and Organophosphate Insecticides in Two Old World Sand Fly Species (Diptera: Psychodidae).

    PubMed

    Li, Andrew Y; Perez de Leon, Adalberto A; Linthicum, Kenneth J; Britch, Seth C; Bast, Joshua D; Debboun, Mustapha

    2015-01-01

    Phlebotomine sand flies are blood-feeding insects that transmit Leishmania parasites that cause various forms of cutaneous and visceral leishmaniasis and sand fly fever viruses (Phlebovirus; Bunyaviridae) in humans. Sand flies pose a significant threat to US military personnel deployed to Leishmania-endemic and sand fly fever endemic regions which include Europe, the Mediterranean basin, Middle East, Central Asia, Southwest Asia, and Africa. A research project supported by the Department of Defense Deployed Warfighter Protection Program was initiated to evaluate the susceptibility of 2 Old World sand fly species, Phlebotomus papatasi and P duboscqi, to a number of commonly used pyrethroid and organophosphate insecticides. A new glass vial bioassay technique based on the CDC bottle assay was developed for this study. The exposure time-mortality relationship at a given insecticide concentration was determined for each insecticide, and their relative toxicity against the 2 sand fly species was ranked based on bioassay results. This study validated the new bioassay technique and also generated baseline insecticide susceptibility data to inform future insecticide resistance monitoring work.

  19. From Clothing to Laundry Water: Investigating the Fate of Phthalates, Brominated Flame Retardants, and Organophosphate Esters.

    PubMed

    Saini, Amandeep; Thaysen, Clara; Jantunen, Liisa; McQueen, Rachel H; Diamond, Miriam L

    2016-09-01

    The accumulation of phthalate esters, brominated flame retardants (BFRs) and organophosphate esters (OPEs) by clothing from indoor air and transfer via laundering to outdoors were investigated. Over 30 days cotton and polyester fabrics accumulated 3475 and 1950 ng/dm(2) ∑5phthalates, 65 and 78 ng/dm(2) ∑10BFRs, and 1200 and 310 ng/dm(2) ∑8OPEs, respectively. Planar surface area concentrations of OPEs and low molecular weight phthalates were significantly greater in cotton than polyester and similar for BFRs and high molecular weight phthalates. This difference was significantly and inversely correlated with KOW, suggesting greater sorption of polar compounds to polar cotton. Chemical release from cotton and polyester to laundry water was >80% of aliphatic OPEs (log KOW < 4), < 50% of OPEs with an aromatic structure, 50-100% of low molecular weight phthalates (log KOW 4-6), and < detection-35% of higher molecular weight phthalates (log KOW > 8) and BFRs (log KOW > 6). These results support the hypothesis that clothing acts an efficient conveyer of soluble semivolatile organic compounds (SVOCs) from indoors to outdoors through accumulation from air and then release during laundering. Clothes drying could as well contribute to the release of chemicals emitted by electric dryers. The results also have implications for dermal exposure.

  20. Electronic and geometric structures of the organophosphate-degrading enzyme from Agrobacterium radiobacter (OpdA).

    PubMed

    Ely, Fernanda; Hadler, Kieran S; Mitić, Nataša; Gahan, Lawrence R; Ollis, David L; Plugis, Nicholas M; Russo, Marie T; Larrabee, James A; Schenk, Gerhard

    2011-06-01

    The organophosphate-degrading enzyme from Agrobacterium radiobacter (OpdA) is a highly efficient catalyst for the degradation of pesticides and some nerve agents such as sarin. OpdA requires two metal ions for catalytic activity, and hydrolysis is initiated by a nucleophilic hydroxide that is bound to one of these metal ions. The precise location of this nucleophile has been contentious, with both a terminal and a metal-ion-bridging hydroxide as likely candidates. Here, we employed magnetic circular dichroism to probe the electronic and geometric structures of the Co(II)-reconstituted dinuclear metal center in OpdA. In the resting state the metal ion in the more secluded α site is five-coordinate, whereas the Co(II) in the solvent-exposed β site is predominantly six-coordinate with two terminal water ligands. Addition of the slow substrate diethyl 4-methoxyphenyl phosphate does not affect the α site greatly but lowers the coordination number of the β site to five. A reduction in the exchange coupling constant indicates that substrate binding also triggers a shift of the μ-hydroxide into a pseudoterminal position in the coordination sphere of either the α or the β metal ion. Mechanistic implications of these observations are discussed.

  1. Variation of Cholinesterase-Based Biosensor Sensitivity to Inhibition by Organophosphate Due To Ionizing Radiation

    PubMed Central

    Pohanka, Miroslav; Koch, Miroslav

    2009-01-01

    A cholinesterase based biosensor was constructed in order to assess the effects of ionizing radiation on exposed AChE. Although the primary objective of the experiment was to investigate the effect of ionizing radiation on the activity of the biosensor, no changes in cholinesterase activity were observed. Current provided by oxidation of thiocholine previously created from acetylthiocholine by enzyme catalyzed reaction was in a range 395–455 nA. No significant influence of radiation on AChE activity was found, despite the current variation. However, a surprising phenomenon was observed when a model organophosphate paraoxon was assayed. Irradiated biosensors seem to be more susceptible to the inhibitory effects of paraoxon. Control biosensors provided a 94 ± 5 nA current after exposure to 1 ppm paraoxon. The biosensors irradiated by a 5 kGy radiation dose and exposed to paraoxon provided a current of 49 ± 6 nA. Irradiation by doses ranging from 5 mGy to 100 kGy were investigated and the mentioned effect was confirmed at doses above 50 Gy. After the first promising experiments, biosensors irradiated by 5 kGy were used for calibration on paraoxon and compared with the control biosensors. Limits of detection 2.5 and 3.8 ppb were achieved for irradiated and non-irradiated biosensors respectively. The overall impact of this effect is discussed. PMID:22346715

  2. Amygdala kindling in immature rats: proconvulsant effect of the organophosphate insecticide-chlorpyrifos.

    PubMed

    Wurpel, J N; Hirt, P C; Bidanset, J H

    1993-01-01

    Administration of the organophosphate insecticide, chlorpyrifos to immature rats exerted a proconvulsant effect on seizures induced by kindling. Chlorpyrifos was administered to 16 or 17 day old rats in a dose range of 0.3 to 10 mg/kg, subcutaneously. Amygdala kindling was performed by stimulating the rats every 15 minutes to a total of 20 stimulations. Kindling occurred more rapidly in the chlorpyrifos treated rats than vehicle treated rats, the proconvulsant effect was dose-dependent. The proconvulsant effect of chlorpyrifos was more pronounced in the early stages of kindling, indicating a possible increase in local excitability of the amygdala in the presence of chlorpyrifos. Chlorpyrifos also reduced the after discharge threshold in the amygdala in a dose-dependent manner and increased the duration of after discharges elicited by electrical stimulus, indicating an increase in excitability of the amygdala. The effects of chlorpyrifos on kindling were additive with xylene: the proconvulsant effect in the early stages of kindling was greatly enhanced by xylene. Xylene, administered alone as a 0.2% solution, reduced the after discharge threshold of the amygdala, increased the after discharge duration and increased the rate of kindling. These experiments demonstrate a proconvulsant effect of chlorpyrifos in amygdala kindling and this proconvulsant action is additive with xylene.

  3. Organophosphate ester (OPE) flame retardants and plasticizers in the open Mediterranean and Black Seas atmosphere.

    PubMed

    Castro-Jiménez, Javier; Berrojalbiz, Naiara; Pizarro, Mariana; Dachs, Jordi

    2014-03-18

    The presence of organophosphate ester (OPE) flame retardants and plasticizers has been confirmed for the first time in the atmosphere over the Mediterranean and Black Seas. Atmospheric aerosol samples were collected during two West-East oceanographic cruises across the Mediterranean and in the southwest Black Sea. This comprehensive assessment of baseline concentrations of aerosol phase OPEs, spatial distribution, and related deposition fluxes reveals levels ranging from 0.4 to 6.0 ng m(-3) for the ∑14OPEs and a lack of significant differences among sub-basins. Levels measured across the Mediterranean Sea and in the Black Sea are in the upper range or higher than those from previous reports for the marine atmosphere, presumably due to proximity to sources. From 13 to 260 tons of OPEs are estimated to be annually loaded to the Mediterranean Sea open waters from the atmosphere. Tris-(1-chloro-2-propyl)phosphate (TCPP) was the most abundant compound over the atmosphere of all the Mediterranean and Black Sea sub-basins, and therefore the chemical reaching surface waters at a higher extent by dry deposition. The atmospheric deposition fluxes of phosphorus due to OPE deposition is a significant fraction of known atmospheric inputs of new organic phosphorus (P), suggesting the relevant role that anthropogenic organic pollutants could play in the P cycle.

  4. Hair and Nails as Noninvasive Biomarkers of Human Exposure to Brominated and Organophosphate Flame Retardants.

    PubMed

    Liu, Liang-Ying; He, Ka; Hites, Ronald A; Salamova, Amina

    2016-03-15

    After the phase-out of polybrominated diphenyl ethers (PBDEs), the use of alternative flame retardants (AFRs), such as FireMaster 550, and of organophosphate esters (OPEs) has increased. However, little is known about human exposure to these chemicals. This lack of biomonitoring studies is partially due to the absence of reliable noninvasive biomarkers of exposure. Human hair and nails can provide integrated exposure measurements, and as such, these matrices can potentially be used as noninvasive biomarkers of exposure to these flame retardants. Paired human hair, fingernail, toenail, and serum samples obtained from 50 adult participants recruited at Indiana University Bloomington campus were analyzed by gas chromatographic mass spectrometry for 36 PBDEs, 9 AFRs, and 12 OPEs. BDE-47, BDE-99, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), di(2-ethylhexyl) tetrabromophthalate (TBPH), tris(1,3-dichloro-2-propyl)phosphate (TDCIPP), and triphenyl phosphate (TPHP) were the most abundant compounds detected in almost all hair, fingernail, and toenail samples. The concentrations followed the order OPEs > TBB+TBPH > Σpenta-BDE. PBDE levels in the hair and nail samples were significantly correlated with their levels in serum (P < 0.05), suggesting that human hair and nails can be used as biomarkers to assess human exposure to PBDEs.

  5. Mutagenicity Assessment of Organophosphates using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism Assay

    PubMed Central

    Bhinder, Preety; Chaudhry, Asha

    2013-01-01

    Objectives: In this study we have evaluated the mutagenicity of organophosphate pesticides acephate, chlorpyrifos, and profenofos using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay with the mosquito Culex quinquefasciatus taken as an experimental model. Materials and Methods: Second instar larvae were treated with LC20 of each pesticide for 24 h and mutations induced in the sequence of mitochondrial COII gene (690bp) were studied from restriction patterns generated with AluI, PacI, and PsiI restriction endonucleases. Results: Variations in the number and size of digested fragments were recorded from treated individuals compared with controls showing that the restriction enzymes created a cut at different locations. In addition, sequences of COII gene from control and treated individuals were also used to confirm the RFLP patterns. From the sequence alignment data, it was found that mutations caused the destruction and generation of restriction sites in the gene sequence of treated individuals. Conclusion: This study indicates that all the three pesticides had potential to induce mutations in the normal sequence of COII gene and also advocates the use of PCR-RFLP assay as an efficient, rapid, and sensitive technique to detect mutagenicity of pesticides. PMID:24403735

  6. Pharmacotherapy to protect the neuromuscular junction after acute organophosphorus pesticide poisoning.

    PubMed

    Bird, Steven B; Krajacic, Predrag; Sawamoto, Keigo; Bunya, Naofumi; Loro, Emanuele; Khurana, Tejvir S

    2016-06-01

    Organophosphorus (OP) pesticide poisoning is a leading cause of morbidity and mortality in the developing world, affecting an estimated three million people annually. Much of the morbidity is directly related to muscle weakness, which develops 1-4 days after poisoning. This muscle weakness, termed the intermediate syndrome (IMS), leads to respiratory, bulbar, and proximal limb weakness and frequently necessitates the use of mechanical ventilation. While not entirely understood, the IMS is most likely due to persistently elevated acetylcholine (ACh), which activates nicotinic ACh receptors at the neuromuscular junction (NMJ). Thus, the NMJ is potentially a target-rich area for the development of new therapies for acute OP poisoning. In this manuscript, we discuss what is known about the IMS and studies investigating the use of nicotinic ACh receptor antagonists to prevent or mitigate NMJ dysfunction after acute OP poisoning. PMID:27258847

  7. OpWise: Operons aid the identification of differentially expressedgenes in bacterial microarray experiments

    SciTech Connect

    Price, Morgan N.; Arkin, Adam P.; Alm, Eric J.

    2005-11-23

    Differentially expressed genes are typically identified by analyzing the variation between replicate measurements. These procedures implicitly assume that there are no systematic errors in the data even though several sources of systematic error are known. Results-OpWise estimates the amount of systematic error in bacterial microarray data by assuming that genes in the same operon have matching expression patterns. OpWise then performs a Bayesian analysis of a linear model to estimate significance. In simulations, OpWise corrects for systematic error and is robust to deviations from its assumptions. In several bacterial data sets, significant amounts of systematic error are present, and replicate-based approaches overstate the confidence of the changers dramatically, while OpWise does not. Finally, OpWise can identify additional changers by assigning genes higher confidence if they are consistent with other genes in the same operon. Although microarray data can contain large amounts of systematic error, operons provide an external standard and allow for reasonable estimates of significance. OpWise is available at http://microbesonline.org/OpWise.

  8. Infantile 4-tert-octylphenol exposure transiently inhibits rat ovarian steroidogenesis and steroidogenic acute regulatory protein (StAR) expression

    SciTech Connect

    Myllymaeki, S.A. . E-mail: saanmy@utu.fi; Karjalainen, M.; Haavisto, T.E.; Toppari, J.; Paranko, J.

    2005-08-22

    Phenolic compounds, such as 4-tert-octylphenol (OP), have been shown to interfere with rat ovarian steroidogenesis. However, little is known about steroidogenic effects of infantile OP exposure on immature ovary. The aim of the present study was to investigate the effects of infantile OP exposure on plasma FSH, LH, estradiol, and progesterone levels in 14-day-old female rats. The effect on ovarian steroidogenic acute regulatory protein (StAR) and FSH receptor (FSHr) expression was analyzed by Western blotting. Ex vivo analysis was carried out for follicular estradiol, progesterone, testosterone, and cAMP production. Sprague-Dawley rats were given OP (0, 10, 50, or 100 mg/kg) subcutaneously on postnatal days 6, 8, 10, and 12. On postnatal day 14, plasma FSH was decreased and progesterone increased significantly at a dose of 100 mg OP/kg. In addition, the highest OP dose advanced the time of vaginal opening in puberty. OP had no effect on infantile LH and estradiol levels or ovarian FSHr content. Ovarian StAR protein content and ex vivo hormone and cAMP production were decreased at all OP doses compared to controls. However, hormone levels recovered independent on FSH and even increased above the control level during a prolonged culture. On postnatal day 35, no statistically significant differences were seen between control and OP-exposed animals in plasma FSH, LH, estradiol, and progesterone levels, or in ovarian StAR protein content. The results indicate that the effect of OP on the infantile ovary is reversible, while more permanent effects in the hypothalamus and pituitary, as described earlier, are involved in the reduction of circulating FSH levels and premature vaginal opening.

  9. Kauai Island Utility Co-op (KIUC) PV integration study.

    SciTech Connect

    Ellis, Abraham; Mousseau, Tom

    2011-08-01

    This report investigates the effects that increased distributed photovoltaic (PV) generation would have on the Kauai Island Utility Co-op (KIUC) system operating requirements. The study focused on determining reserve requirements needed to mitigate the impact of PV variability on system frequency, and the impact on operating costs. Scenarios of 5-MW, 10-MW, and 15-MW nameplate capacity of PV generation plants distributed across the Kauai Island were considered in this study. The analysis required synthesis of the PV solar resource data and modeling of the KIUC system inertia. Based on the results, some findings and conclusions could be drawn, including that the selection of units identified as marginal resources that are used for load following will change; PV penetration will displace energy generated by existing conventional units, thus reducing overall fuel consumption; PV penetration at any deployment level is not likely to reduce system peak load; and increasing PV penetration has little effect on load-following reserves. The study was performed by EnerNex under contract from Sandia National Laboratories with cooperation from KIUC.

  10. Quantitative comparisons of acute toxicity of organic chemicals to rat and fish

    SciTech Connect

    Janardan, S.K.; Olson, C.S.; Schaeffer, D.J.

    1984-12-01

    Relationships between the acute toxicity of chemicals to fish (LC50) and rat (LD50) were analyzed using a Model II regression analysis after logarithmic transformation. (Model II regression assumes errors in both variables.) Significant correlations were found among bluegill and fathead minnow LC50S and rat LD50 values for the priority pollutants. Fathead minnow and bluegill LC50S for 48 pesticides were highly correlated. No correlations were found between fishes and rats for carbamate plus organophosphate pesticides. Correlations were obtained among all species for the combined priority pollutant plus pesticide data and for chlorinated pesticides.

  11. Pediatric Acute Lymphoblastic Leukemia and Exposure to Pesticides

    PubMed Central

    Soldin, Offie P.; Nsouly-Maktabi, Hala; Genkinger, Jeanine M.; Loffredo, Christopher A.; Ortega-Garcia, Juan Antonio; Colantino, Drew; Barr, Dana B.; Luban, Naomi L.; Shad, Aziza T.; Nelson, David

    2013-01-01

    Organophosphates are pesticides ubiquitous in the environment and have been hypothesized as one of the risk factors for acute lymphoblastic leukemia (ALL). In this study, we evaluated the associations of pesticide exposure in a residential environment with the risk for pediatric ALL. This is a case–control study of children newly diagnosed with ALL, and their mothers (n = 41 child–mother pairs) were recruited from Georgetown University Medical Center and Children's National Medical Center in Washington, DC, between January 2005 and January 2008. Cases and controls were matched for age, sex, and county of residence. Environmental exposures were determined by questionnaire and by urinalysis of pesticide metabolites using isotope dilution gas chromatography–high-resolution mass spectrometry. We found that more case mothers (33%) than controls (14%) reported using insecticides in the home (P < 0.02). Other environmental exposures to toxic substances were not significantly associated with the risk of ALL. Pesticide levels were higher in cases than in controls (P < 0.05). Statistically significant differences were found between children with ALL and controls for the organophosphate metabolites diethylthiophosphate (P < 0.03) and diethyldithiophosphate (P < 0.05). The association of ALL risk with pesticide exposure merits further studies to confirm the association. PMID:19571777

  12. Autonomic Function following Acute Organophosphorus Poisoning: A Cohort Study

    PubMed Central

    Jayasinghe, Sudheera S.; Pathirana, Kithsiri D.

    2012-01-01

    Autonomic dysfunction after chronic low level exposure to organophosphorus (OP) pesticides has been consistently reported in the literature, but not following a single acute overdose. In order to study autonomic function after an acute OP overdose, sixty-six overdose patients were compared to 70 matched controls. Assessment of autonomic function was done by heart rate response to standing, deep breathing (HR-DB) and Valsalva manoeuvre; blood pressure (BP) response to standing and sustained hand grip; amplitude and latency of sympathetic skin response (SSR); pupil size and post-void urine volume. The patients were assessed one and six weeks after the exposure. The number of patients who showed abnormal autonomic function compared to standard cut-off values did not show statistically significantly difference from that of controls by Chi-Square test. When compared to the controls at one week the only significant differences consistent with autonomic dysfunction were change of diastolic BP 3 min after standing, HR-DB, SSR-Amplitude, SSR-Latency, post-void urine volume and size of the pupil. At 6 weeks significant recovery of autonomic function was observed and only HR-DB was decreased to a minor degree, −5 beats/min [95%CI 2–8]. This study provides good evidence for the lack of long term autonomic dysfunction following acute exposure to OP pesticides. PMID:22655091

  13. [Isolation and identification of a bacterial strain JS018 capable of degrading several kinds of organophosphate pesticides].

    PubMed

    Jiang, Yu-Ji; Deng, You-Jin; Liu, Xin-Rui; Xie, Bao-Gui; Hu, Fang-Ping

    2006-06-01

    Organophosphate pesticides are used widely all over the world and play an important role in plant pest control. However these pesticides are considered as pollutants and harmful to human health. To search for microorganisms that can degrade organophosphate pesticides with high efficiency, a bacterial strain, coded as JS018, was isolated and screened from the soil in the vicinity of Shanming Pesticides Factory, Shanming, Fujian. Laboratory tests showed that the bacterium could degrade several kinds of organophosphate pesticides, such as Parathion-methyl and phoxin. The strain's degrading rates on phoxin, Parathion-methyl, hostathion and dichlorvos in LB liquid fermentation medium for 36 h were 99%, 96%, 80.4% and 69.0% respectively. The bacterial colonies on LB plate appeared shiny and pale-pink in color. The bacteria were Gram-negative coccoids, 0.5 - 0.7 microm in diameter. They grew well at 30 - 38 degrees C and pH 7.0 - 9.0. The optimal temperature and pH for cell growth was 32 degrees C and pH 7.5 - 8.0, respectively. They did not grow in medium containing 6% or more NaCl. The antibiotic susceptibility tests showed that the strain was resistant to ampicillin, penicillin and lincomycin. It was sensitive to kanamycin, tetracycline and gentamicin. Laboratory tests also showed that the strain could ferment D-glucose, trehalose, melezitose and ethanol. It was negative in the production of indole and hydrogen sulfide. It could not liquefy gelatin, utilize citrate, nor ferment L-arabinose, sucrose, D-mannitol, D-xylose, fructose, D-galactose, maltose or lactose. The catalase, urease and nitrate reduction were positive. Based on its morphological, physiological and biochemical properties as well as the 16S rDNA sequence analysis result, the strain was tentatively identified as Roseomonas sp. PMID:16933622

  14. Measurement of organophosphate metabolites in postpartum meconium as a potential biomarker of prenatal exposure: a validation study.

    PubMed Central

    Whyatt, R M; Barr, D B

    2001-01-01

    Experimental data have linked exposure to prenatal organophosphates to adverse neurocognitive sequalae. However, epidemiologic research has been hampered by lack of reliable dosimeters. Existing biomarkers reflect short-term exposure only. Measurements of pesticides in postpartum meconium may yield a longer-term dosimeter of prenatal exposure. As the initial step in biomarker validation, this research determined background levels, detection limits, and stabilities of six organophosphate metabolites in meconium: diethylphosphate (DEP), diethylthiophosphate (DETP), diethyldithiophosphate (DEDTP), dimethylphosphate (DMP), dimethylthiophosphate (DMTP), and dimethyldithiophosphate (DMDTP). Calibration curves were also constructed. The meconium was collected from 20 newborns at New York Presbyterian Hospital; analyses were undertaken at the Centers for Disease Control and Prevention (CDC). DEP was detected in 19/20 samples (range 0.8-3.2 microg/g) and DETP was detected in 20/20 (range 2.0-5.6 microg/g). DMP and DEDTP were each detected in 1/20 (at 16 and 1.8 microg/g, respectively). DMTP and DMDTP were not detected. Detection limits were comparable to or lower than those in urine; levels were similar to those seen in adult urine in population-based research. Metabolites were stable at room temperature over 12 hr. Calibration curves were linear over the range tested (0.5-400 microg/g); recoveries ranged from 18% to 66%. Using isotope dilution, recoveries of each analyte in individual samples can be corrected automatically based on the recovery of the respective stable isotope-labeled analogue, making this method fully quantitative. Results indicate that measurements of organophosphate metabolites in meconium have promise as biomarkers of prenatal exposure. Further research is needed to determine the time frame of exposure represented by pesticide levels in meconium and to evaluate the dose-response relationship. PMID:11335191

  15. Two-dimensional ion chromatography for the separation of ionic organophosphates generated in thermally decomposed lithium hexafluorophosphate-based lithium ion battery electrolytes.

    PubMed

    Kraft, Vadim; Grützke, Martin; Weber, Waldemar; Menzel, Jennifer; Wiemers-Meyer, Simon; Winter, Martin; Nowak, Sascha

    2015-08-28

    A two-dimensional ion chromatography (IC/IC) technique with heart-cutting mode for the separation of ionic organophosphates was developed. These analytes are generated during thermal degradation of three different commercially available Selectilyte™ lithium ion battery electrolytes. The composition of the investigated electrolytes is based on 1M lithium hexafluorophosphate (LiPF6) dissolved in ethylene carbonate/dimethyl carbonate (50:50wt%, LP30), ethylene carbonate/diethyl carbonate (50:50wt%, LP40) and ethylene carbonate/ethyl methyl carbonate (50:50wt%, LP50). The organophosphates were pre-separated from PF6(-) anion on the low capacity A Supp 4 column, which was eluted with a gradient step containing acetonitrile. The fraction containing analytes was retarded on a pre-concentration column and after that transferred to the high capacity columns, where the separation was performed isocratically. Different stationary phases and eluents were applied on the 2nd dimension for the investigation of retention times, whereas the highly promising results were obtained with a high capacitive A Supp 10 column. The organophosphates generated in LP30 and LP40 electrolytes could be separated by application of an aqueous NaOH eluent providing fast analysis time within 35min. For the separation of the organophosphates of LP50 electrolyte due to its complexity a NaOH eluent containing a mixture of methanol/H2O was necessary. In addition, the developed two dimensional IC method was hyphenated to an inductively coupled plasma mass spectrometer (ICP-MS) using aqueous NaOH without organic modifiers. This proof of principle measurement was carried out for future quantitative investigation regarding the concentration of the ionic organophosphates. Furthermore, the chemical stability of several ionic organophosphates in water and acetonitrile at room temperature over a period of 10h was investigated. In both solvents no decomposition of the investigated analytes was observed and

  16. Therapy against organophosphate poisoning: The importance of anticholinergic drugs with antiglutamatergic properties

    SciTech Connect

    Weissman, Ben Avi Raveh, Lily

    2008-10-15

    Potent cholinesterase inhibitors (e.g., soman, sarin), induce a wide range of deleterious effects including convulsions, behavioral impairments and ultimately, death. Due to the likelihood of various scenarios of military or terrorist attacks by these and other chemical weapons, research has to be aimed at finding optimal therapies. Early accumulation of acetylcholine in synaptic clefts was suggested to trigger an array of toxic events including an excessive release of glutamate, culminating in the activation of its receptors. Stimulation of the N-Methyl-D-Aspartate (NMDA) subtype of these receptors was associated with the neuronal injury that initiates organophosphate-induced brain damage. The notion of a stepwise mechanism yielded treatments based on a combination of an immediate administration of enzyme reactivators and anticholinergic drugs. This strategy dramatically increased survival rates but did not abolish convulsions and failed to prevent the ensuing cognitive dysfunction. Efforts to improve this paradigm by adding anticonvulsants or antiglutamatergic drugs with anti-epileptic characteristics produced dubious results. Under these conditions, benactyzine and caramiphen, agents with anticholinergic and antiglutamatergic properties, provided improved protection when introduced as adjunct agents to oximes, reversible cholinesterase inhibitors and/or specific antimuscarinic drugs such as atropine. In contrast, the specific antimuscarinic drug scopolamine failed to block soman-induced changes in glutamatergic and behavioral parameters even when given prophylactically. These findings along with a large number of additional reports led towards the conclusion that the therapeutic advantage of drugs such as benactyzine and caramiphen could derive from their ability to modulate central cholinergic and glutamate neurotransmission.

  17. Concentrations in air of organobromine, organochlorine and organophosphate flame retardants in Toronto, Canada

    NASA Astrophysics Data System (ADS)

    Shoeib, Mahiba; Ahrens, Lutz; Jantunen, Liisa; Harner, Tom

    2014-12-01

    Concentrations of organobromine (BFRs), organochlorine (CFRs) and organophosphate esters flame retardants and plasticizers (PFRs) in air were monitored for over one year at an urban site in Toronto, Canada during 2010-2011. The mean value for polybrominated diphenyl ethers (BDEs) (gas + particle phase) was 38 pg/m3 with BDE-47 and BDE-99 as the dominant congeners. The mean concentrations in air for ∑non-BDE (BFRs and CFRs), was 9.6 pg/m3 - about four times lower than the BDEs. The brominated FRs: TBP-AE, BTBPE, EH-TBB, BEH-TEBP and the chlorinated syn- and anti-DP were detected frequently, ranging from 87% to 96%. Highest concentrations in air among all flame retardant classes were observed for the Σ-PFRs. The yearly mean concentration in air for ΣPFRs was 2643 pg/m3 with detection frequency higher than 80%. Except for TBP-AE and b- DBE-DBCH, non-BDEs (BFRs, CFRs and PFRs) were mainly associated with the particle phase. BDE concentrations in air were positively correlated with temperature indicating that volatilization from local sources was an important factor controlling levels in air. This correlation did not hold for most BFRs, CFRs and PFRs which were mainly on particles. For these compounds, air concentrations in Toronto are likely related to emissions from point sources and advective inputs. This study highlights the importance of urban air monitoring for FRs. Urban air can be considered a sentinel for detecting changes in the use and application of FRs in commercial products.

  18. Organophosphate Flame Retardants Act as Endocrine-Disrupting Chemicals in MA-10 Mouse Tumor Leydig Cells.

    PubMed

    Schang, Gauthier; Robaire, Bernard; Hales, Barbara F

    2016-04-01

    The organophosphate flame retardants (OPFRs) have emerged as alternatives to banned brominated flame retardants but little is known about their possible activity as endocrine disruptors. Our goal was to compare the effects of 7 commonly used OPFRsin vitroon MA-10 mouse Leydig tumor cells to those of a major brominated flame retardant, 2,2',4,4'-tetrabromodiphenyl ether (BDE-47). The effects of OPFRs and BDE-47 on mitochondrial activity, cell counts, oxidative stress, steroid secretion and gene expression were investigated. BDE-47 and all 7 OPFRs tested significantly reduced MA-10 cell mitochondrial activity (concentrations ≥50 μM) and cell number (concentrations ≥10 μM). All of the OPFRs significantly increased (10 μM, 1.7-4.4-fold) superoxide production whereas BDE-47 had no significant effect. Basal progesterone production was significantly increased (10 μM, 1.5 to 3-fold) by 2-ethylhexyl diphenyl phosphate, isodecyl diphenyl phosphate, isopropylated triphenyl phosphate, tert-butylphenyl diphenyl phosphate, and tricresyl phosphate, while BDE-47, triphenyl phosphate and tri-o-cresyl phosphate had no effect. Interestingly, isopropylated triphenyl phosphate enhanced dbcAMP-stimulated steroid production (∼2-fold), while tri-o-cresyl phosphate decreased (∼2/3) LH-stimulated steroid production. Several OPFRs affected the expression of genes involved in the biosynthesis of progesterone. In conclusion, all the OPFRs tested affected mitochondrial activity, cell survival, and superoxide production. Basal or stimulated steroid secretion was affected by all of the OPFRs except triphenyl phosphate; BDE-47 had no effect. Hence, the OPFRs currently used as alternatives affect Leydig cells to a greater extent than the brominated flame retardants that they have replaced.

  19. Mishandling and exposure of farm workers in Qatar to organophosphate pesticides.

    PubMed

    Shomar, Basem; Al-Saad, Khalid; Nriagu, Jerome

    2014-08-01

    We used a combination of subjective (questionnaire) and objective (urinary metabolites) measurements to evaluate factors that can predict the exposure of farm workers in Qatar to organophosphate pesticides and to assess whether the levels of exposure are associated with any self-reported health outcomes. The results show that pesticides were being extensively mishandled in the farms. Very few (<2%) of the farm workers knew the names of the pesticide they were using, and about one-third of the participants did not know the amount of pesticides to be applied to the crops. Nearly all (96%) of the participants had participated in mixing pesticides together before use and few (29%) used protective clothing while engaged in this operation. A significant number of participants (18%) had no knowledge that pesticides are a health hazard. At least one dialkyllphosphate (DAP) metabolite was detected in every worker. The geometric mean (GM) concentration of the dimethylalkylphosphates (DMAP) was 108 nM (range, from below the limit of detection (LOD) to 351 nM), and the GM for the diethylalkylphosphates (DEAP) was 43 nM (range, LOD-180 nM). The GM for total concentration of the metabolites (DAP) of 146 nM (maximum value estimated to be 531 nM) is below the values that have been reported for farmers in some countries, but higher than the levels in the general populations of many countries. We explored the influence of metal exposure and found consistent and negative relationships between the DAP metabolites and the concentrations of most of the trace elements in the urine of the farm workers; the negative associations were statistically significant for Cr, Mn, Fe, Ni, As, and Pb. We suspect that the negative associations are not source-dependent but may be reflective of antagonistic relationships in human metabolism of OPPs and trace metals; hence we recommend that metals should be included as co-factors in assessing the health effects of OPP exposure.

  20. Human exposure pathways to organophosphate triesters - a biomonitoring study of mother-child pairs.

    PubMed

    Cequier, Enrique; Sakhi, Amrit Kaur; Marcé, Rosa Maria; Becher, Georg; Thomsen, Cathrine

    2015-02-01

    The worldwide ban of several formulations of brominated flame retardants has caused an increase in the production of organophosphorus flame retardants (PFRs) to meet the existing fire regulations for a wide range of household products. This biomonitoring study surveys the occurrence of the metabolites from PFRs and related plasticizers (dialkyl and diaryl phosphates; DAPs) in urine from a Norwegian mother-child cohort (48 mothers and 54 children). Concentrations of DAPs were higher in the children than in their mothers (Wilcoxon signed-rank test p=0.001). Median urinary concentrations of diphenyl phosphate (DPHP) were 1.1 and 0.51ng/mL in children and mothers, respectively, followed by bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) with medians of 0.23 and 0.12ng/mL, respectively. Detection frequencies for bis(2-butoxyethyl) phosphate (BBOEP) in urine from children and mothers were 32 and 1%, respectively (median<0.18ng/mL), and for di-n-butyl phosphate (DNBP) 15 and 8%, respectively (median<0.12ng/mL). The concentrations of DPHP and BDCIPP in urine from children were significantly correlated with those found for their parent compounds in air and dust from the households (Spearman's rank correlations 0.30organophosphate metabolites in urine and food consumption data obtained through a 24hour recall were seen. This suggests that the residential environment is a more important exposure pathway to PFRs than the diet.

  1. Evaluation of two passive samplers for the analysis of organophosphate esters in the ambient air.

    PubMed

    Liu, Ruirui; Lin, Yongfeng; Liu, Runzeng; Hu, Fanbao; Ruan, Ting; Jiang, Guibin

    2016-01-15

    Both polyurethane foam (PUF) and sorbent-impregnated PUF (SIP) passive air sampling (PAS) methods were deployed and compared separately for the analysis of organophosphate esters (OPEs) in outdoor atmospheric environment. During an continuous period of 84 days, parallel samples were also collected by a high-volume active air sampler (HV-AAS) to assess the contamination levels and to calibrate uptake parameters of PAS. The total concentration of OPEs in both particulate and gaseous phases ranged from 1.50 to 5.64ng m(-3) in ambient air. Tris(2-chloroisopropyl) phosphate (TCPP) was the dominating analog, representing 78±9% of total OPE concentration. SIP-PAS showed longer linear-phase sampling period for TCPP, and accumulated more amount of the most volatile triethyl phosphate (TEP) and tributyl phosphate (TBP) homologues, while similar sorption performances of both PAS methods were found for most of the semi-volatile OPEs. Linear sampling rates in PUF-PAS and SIP-PAS disks were calculated for individual OPEs except for TEP and TBP, and the average uptake rates (3.3±1.1 and 3.5±1.7m(3)d(-1), respectively) were close to the acknowledged value (4m(-3)d(-1)) for persistent organic pollutants. Besides, isotopic labeled D15-Triphenyl phosphate (TPhP) could be used as a viable depuration compound to calculate site-specific sampling rates of OPEs, with a linear loss of up to ∼60% at the end of deployment time. PMID:26592578

  2. Human dermal absorption of chlorinated organophosphate flame retardants; implications for human exposure.

    PubMed

    Abou-Elwafa Abdallah, Mohamed; Pawar, Gopal; Harrad, Stuart

    2016-01-15

    Tris-2-chloroethyl phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCIPP) and tris-1,3-dichloropropyl phosphate (TDCIPP) are organophosphate flame retardants (PFRs) widely applied in a plethora of consumer products despite their carcinogenic potential. Human dermal absorption of these PFRs is investigated for the first time using human ex vivo skin and EPISKIN™ models. Results of human ex vivo skin experiments revealed 28%, 25% and 13% absorption of the applied dose (500 ng/cm(2), finite dose) of TCEP, TCIPP and TDCIPP, respectively after 24h exposure. The EPISKIN™ model showed enhanced permeability values (i.e. weaker barrier), that were respectively 16%, 11% and 9% for TCEP, TCIPP and TDCIPP compared to human ex vivo skin. However, this difference was not significant (P>0.05). Estimated permeability constants (Kp, cm/h) showed a significant negative correlation with log Kow for the studied contaminants. The effect of hand-washing on dermal absorption of PFRs was investigated. Washing reduced overall dermal absorption, albeit to varying degrees depending on the physicochemical properties of the target PFRs. Moreover, slight variations of the absorbed dose were observed upon changing the dosing solution from acetone to 20% Tween 80 in water, indicating the potential influence of the dose vehicle on the dermal absorption of PFRs. Finally, estimated dermal uptake of the studied PFRs via contact with indoor dust was higher in UK toddlers (median ΣPFRs=36 ng/kg bw day) than adults (median ΣPFRs=4 ng/kg bw day). More research is required to fully elucidate the toxicological implications of such exposure.

  3. Atmospheric transport of organophosphate pesticides from California's Central Valley to the Sierra Nevada Mountains

    USGS Publications Warehouse

    Zabik, John M.; Seiber, James N.

    1993-01-01

    Atmospheric transport of organophosphate pesticides from California's Central Valley to the Sierra Nevada mountains was assessed by collecting air- and wet-deposition samples during December, January, February, and March, 1990 to 1991. Large-scale spraying of these pesticides occurs during December and January to control insect infestations in valley orchards. Sampling sites were placed at 114- (base of the foothills), 533-, and 1920-m elevations. Samples acquired at these sites contained chlorpyrifos [phosphorothioic acid; 0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl) ester], parathion [phosphorothioic acid, 0-0-diethylo-(4-nitrophenyl) ester], diazinon {phosphorothioic acid, 0,0-diethyl 0-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] ester} diazinonoxon {phosphoric acid, 0,0-diethyl 0-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] ester}, and paraoxon [phosphoric acid, 0,0-diethyl 0-(4-nitrophenyl) ester] in both air and wet deposition samples. Air concentrations of chloropyrifos, diazinon and parathion ranged from 13 to 13 000 pg/m3 at the base of the foothills. At 533-m air concentrations were below the limit of quantification (1.4 pg/m3) to 83 pg/m3 and at 1920 m concentrations were below the limit of quantification. Concentrations in wet deposition varied with distance and elevation from the Central Valley. Rainwater concentrations at the base of the foot hills ranged from 16 to 7600 pg/mL. At 533-m rain and snow water concentrations ranged from below the limit of quantification (1.3 pg/mL) to 140 pg/mL and at 1920 m concentrations ranged from below the limit of quantification to 48 pg/mL. These findings indicate that atmospheric transport of pesticides applied in the valley to the Sierra Nevada mountains is occurring, but the levels decrease as distance and elevation increase from the valley floor.

  4. An evaluation of the inhibition of human butyrylcholinesterase and acetylcholinesterase by the organophosphate chlorpyrifos oxon

    SciTech Connect

    Shenouda, Josephine; Green, Paula; Sultatos, Lester

    2009-12-01

    Acetylcholinesterase (EC 3.1.1.7) and butyrylcholinesterase (EC 3.1.1.8) are enzymes that belong to the superfamily of alpha/beta-hydrolase fold proteins. While they share many characteristics, they also possess many important differences. For example, whereas they have about 54% amino acid sequence identity, the active site gorge of acetylcholinesterase is considerably smaller than that of butyrylcholinesterase. Moreover, both have been shown to display simple and complex kinetic mechanisms, depending on the particular substrate examined, the substrate concentration, and incubation conditions. In the current study, incubation of butyrylthiocholine in a concentration range of 0.005-3.0 mM, with 317 pM human butyrylcholinesterase in vitro, resulted in rates of production of thiocholine that were accurately described by simple Michaelis-Menten kinetics, with a K{sub m} of 0.10 mM. Similarly, the inhibition of butyrylcholinesterase in vitro by the organophosphate chlorpyrifos oxon was described by simple Michaelis-Menten kinetics, with a k{sub i} of 3048 nM{sup -1} h{sup -1}, and a K{sub D} of 2.02 nM. In contrast to inhibition of butyrylcholinesterase, inhibition of human acetylcholinesterase by chlorpyrifos oxon in vitro followed concentration-dependent inhibition kinetics, with the k{sub i} increasing as the inhibitor concentration decreased. Chlorpyrifos oxon concentrations of 10 and 0.3 nM gave k{sub i}s of 1.2 and 19.3 nM{sup -1} h{sup -1}, respectively. Although the mechanism of concentration-dependent inhibition kinetics is not known, the much smaller, more restrictive active site gorge of acetylcholinesterase almost certainly plays a role. Similarly, the much larger active site gorge of butyrylcholinesterase likely contributes to its much greater reactivity towards chlorpyrifos oxon, compared to acetylcholinesterase.

  5. Occurrence and risk assessment of organophosphate esters in drinking water from Eastern China.

    PubMed

    Ding, Jinjian; Shen, Xiaoli; Liu, Weiping; Covaci, Adrian; Yang, Fangxing

    2015-12-15

    Organophosphate esters (OPEs) are ubiquitous in the environment and may pose potential health risks to humans. Drinking water is suspected as one possible exposure pathway of OPEs to humans. In this study, we investigated the residues of 9 OPEs in five types of drinking water in Eastern China. The median concentrations of Σ9OPEs were determined to be 3.99, 4.50, 27.6, 59.2 and 192ng/L in the bottled, well, barreled, direct drinking and tap waters, respectively. Triethyl phosphate (TEP) was the most abundant OPE in the tap water and filtered drinking water with median concentrations of 50.2 and 30.2ng/L, respectively. The mixture of tri(chloropropyl) phosphate (TCPP) and tri(chloroisopropyl) phosphate (TCIPP), named here as TCPP, dominated in the barreled and well water with median concentrations of 8.04 and 2.49ng/L, respectively. The calculated average daily doses of OPEs ranged from 0.14 to 7.07ng/kgbw/day for people consuming the five different types of drinking water. Among the drinking water, the tap water exhibited the highest exposure doses of OPEs. The calculated non-cancer hazard quotients (10(-4)-10(-7)) from OPEs were much lower than the theoretical threshold of risk. The carcinogenic risks posed by TCEP were very low (<10(-7)) for all types of drinking water. The results revealed that there was currently low risk to human health from exposure to OPEs through drinking water in Eastern China.

  6. Occurrence and risk assessment of organophosphate esters in drinking water from Eastern China.

    PubMed

    Ding, Jinjian; Shen, Xiaoli; Liu, Weiping; Covaci, Adrian; Yang, Fangxing

    2015-12-15

    Organophosphate esters (OPEs) are ubiquitous in the environment and may pose potential health risks to humans. Drinking water is suspected as one possible exposure pathway of OPEs to humans. In this study, we investigated the residues of 9 OPEs in five types of drinking water in Eastern China. The median concentrations of Σ9OPEs were determined to be 3.99, 4.50, 27.6, 59.2 and 192ng/L in the bottled, well, barreled, direct drinking and tap waters, respectively. Triethyl phosphate (TEP) was the most abundant OPE in the tap water and filtered drinking water with median concentrations of 50.2 and 30.2ng/L, respectively. The mixture of tri(chloropropyl) phosphate (TCPP) and tri(chloroisopropyl) phosphate (TCIPP), named here as TCPP, dominated in the barreled and well water with median concentrations of 8.04 and 2.49ng/L, respectively. The calculated average daily doses of OPEs ranged from 0.14 to 7.07ng/kgbw/day for people consuming the five different types of drinking water. Among the drinking water, the tap water exhibited the highest exposure doses of OPEs. The calculated non-cancer hazard quotients (10(-4)-10(-7)) from OPEs were much lower than the theoretical threshold of risk. The carcinogenic risks posed by TCEP were very low (<10(-7)) for all types of drinking water. The results revealed that there was currently low risk to human health from exposure to OPEs through drinking water in Eastern China. PMID:26363608

  7. Occurrence of organophosphate esters in surface water and ground water in Germany.

    PubMed

    Fries, E; Puttmann, W

    2001-12-01

    The present investigation was carried out to quantify the three organophosphate esters, tributyl phosphate (TBP), tris(2-chloroethyl) phosphate(TCEP) and tris(2-butoxyethyl) phosphate(TBEP), in river, rain and ground water obtained from several locations in Germany, and to compare the data with those obtained about 15 years ago. Additionally, one influent and one effluent sample of waste water from a local waste water treatment plant were investigated. The applied analytical method is based on solid phase extraction (SPE), in order to concentrate polar compounds from water samples, followed by gas chromatography-mass spectrometry (GC-MS) of the extracts. A total of 5 1 of the respective water samples was used for extraction purposes and analyte recoveries were all > or = 83%. The detection limit for the target analytes was 1 ng l(-1) and the relative standard deviations for replicate injections (n = 10) were 14.0% for TBP, 12.6% for TCEP and 9.9% for TBEP. The presence of the organophosphorus compounds, TBP, TCEP and TBEP, in Germany has resulted in water concentrations of 17-1,510 ng l(-1) in the Rhine, Elbe, Main, Oder, Nidda and Schwarzbach Rivers. The maximum value of TBP measured in the Rhine River was 17 times lower than the maximum value measured 10 years ago. The maximum value of TCEP measured in the Rhine River was 100 times lower than the maximum value measured in previous investigations. The maximum concentration of TBEP measured in the Elbe River was seven times higher than the value measured 16 years ago. Similar concentrations of TBP, TCEP and TBEP were also detected in ground water and rain water. The highest levels of these compounds were detected in samples of waste water.

  8. Occupational exposure of air crews to tricresyl phosphate isomers and organophosphate flame retardants after fume events.

    PubMed

    Schindler, Birgit Karin; Weiss, Tobias; Schütze, Andre; Koslitz, Stephan; Broding, Horst Christoph; Bünger, Jürgen; Brüning, Thomas

    2013-04-01

    Aircraft cabin air can possibly be contaminated by tricresyl phosphates (TCP) from jet engine oils during fume events. o-TCP, a known neurotoxin, has been addressed to be an agent that might cause the symptoms reported by cabin crews after fume events. A total of 332 urine samples of pilots and cabin crew members in common passenger airplanes, who reported fume/odour during their last flight, were analysed for three isomers of tricresyl phosphate metabolites as well as dialkyl and diaryl phosphate metabolites of four flame retardants. None of the samples contained o-TCP metabolites above the limit of detection (LOD 0.5 μg/l). Only one sample contained metabolites of m- and p-tricresyl phosphates with levels near the LOD. Median metabolite levels of tributyl phosphate (TBP), tris-(2-chloroethyl) phosphate (TCEP) and triphenyl phosphate (TPP) (DBP 0.28 μg/l; BCEP 0.33 μg/l; DPP 1.1 μg/l) were found to be significantly higher than in unexposed persons from the general population. Median tris-(2-chloropropyl) phosphate (TCPP) metabolite levels were significantly not higher in air crews than in controls. Health complaints reported by air crews can hardly be addressed to o-TCP exposure in cabin air. Elevated metabolite levels for TBP, TCEP and TPP in air crews might occur due to traces of hydraulic fluid in cabin air (TBP, TPP) or due to release of commonly used flame retardants from the highly flame protected environment in the airplane. A slight occupational exposure of air crews to organophosphates was shown. PMID:23179756

  9. The Vida Verde Women's Co-Op: Brazilian immigrants organizing to promote environmental and social justice.

    PubMed

    Gute, David M; Siqueira, Eduardo; Goldberg, Julia S; Galvão, Heloisa; Chianelli, Mônica; Pirie, Alex

    2009-11-01

    We reviewed the key steps in the launch of the Vida Verde Women's Co-Op among Brazilian immigrant housecleaners in Somerville, MA. The co-op provides green housecleaning products, encourages healthy work practices, and promotes a sense of community among its members. We conducted in-depth interviews with 8 of the first co-op members, who reported a reduction in symptoms associated with the use of traditional cleaning agents and a new sense of mutual support. Critical to the co-op's success have been the supportive roles of its academic partners (Tufts University and the University of Massachusetts, Lowell), effective media outreach, and a focus on advancing social justice. Next steps include implementing a formal business plan and assessing the appropriateness of cooperatives in other industries.

  10. Study on multiple-hops performance of MOOC sequences-based optical labels for OPS networks

    NASA Astrophysics Data System (ADS)

    Zhang, Chongfu; Qiu, Kun; Ma, Chunli

    2009-11-01

    In this paper, we utilize a new study method that is under independent case of multiple optical orthogonal codes to derive the probability function of MOOCS-OPS networks, discuss the performance characteristics for a variety of parameters, and compare some characteristics of the system employed by single optical orthogonal code or multiple optical orthogonal codes sequences-based optical labels. The performance of the system is also calculated, and our results verify that the method is effective. Additionally it is found that performance of MOOCS-OPS networks would, negatively, be worsened, compared with single optical orthogonal code-based optical label for optical packet switching (SOOC-OPS); however, MOOCS-OPS networks can greatly enlarge the scalability of optical packet switching networks.

  11. An investigation of potential applications of OP-SAPS: Operational sampled analog processors

    NASA Technical Reports Server (NTRS)

    Parrish, E. A.; Mcvey, E. S.

    1976-01-01

    The impact of charge-coupled device (CCD) processors on future instrumentation was investigated. The CCD devices studied process sampled analog data and are referred to as OP-SAPS - operational sampled analog processors. Preliminary studies into various architectural configurations for systems composed of OP-SAPS show that they have potential in such diverse applications as pattern recognition and automatic control. It appears probable that OP-SAPS may be used to construct computing structures which can serve as special peripherals to large-scale computer complexes used in real time flight simulation. The research was limited to the following benchmark programs: (1) face recognition, (2) voice command and control, (3) terrain classification, and (4) terrain identification. A small amount of effort was spent on examining a method by which OP-SAPS may be used to decrease the limiting ground sampling distance encountered in remote sensing from satellites.

  12. Harvesting Your Prof Crop: Nine Tips for Launching an Op-Ed Program.

    ERIC Educational Resources Information Center

    Bennett, Joseph L.

    1983-01-01

    Faculty can be helpful by providing commentaries to newspaper op-ed pages, but such a public relations program requires consistency, tact, good internal communications, thoughtfulness, and marketing skills. (MSE)

  13. Usefulness of the Co-op Experience: A Study of Community College Students.

    ERIC Educational Resources Information Center

    Krebs, Uwe (Hugh)

    1987-01-01

    Analyzes the perceived usefulness of the co-op experience of community college graduates from the Production and Operating Management and the Marketing Management programs at Centennial College in Ontario. (JOW)

  14. Effect of different buffers on kinetic properties of human acetylcholinesterase and the interaction with organophosphates and oximes.

    PubMed

    Wille, T; Thiermann, H; Worek, F

    2011-03-01

    Acetylcholinesterase (AChE) is the primary target of organophosphorus compounds (OP). The investigation into interactions between AChE, OP and oximes in vitro may be affected by the experimental conditions, e.g. by the buffer system. Hence, it was tempting to investigate the Michaelis-Menten kinetics and the inhibition and reactivation kinetics of paraoxon-ethyl, sarin, soman and VX in the presence of phosphate, MOPS, Tyrode and TRIS buffer with human AChE. Compared to phosphate buffer, the inhibition and reactivation kinetics of human erythrocyte AChE were markedly changed by TRIS and in part by MOPS, whereas Tyrode showed similar results to phosphate buffer. These results indicate an effect of the tested buffers on the properties of AChE, and an interaction between OP and oximes has to be considered for the design of in vitro studies and may impair the comparison of data from different laboratories. In view of the comparability of human in vitro kinetic data determined with phosphate buffer with data from human OP poisoning, it seems to be a suitable buffer for the investigation into interactions between AChE, OP and oximes.

  15. Glyphosate poisoning with acute pulmonary edema.

    PubMed

    Thakur, Darshana Sudip; Khot, Rajashree; Joshi, P P; Pandharipande, Madhuri; Nagpure, Keshav

    2014-01-01

    GlySH-surfactant herbicide (GlySH), one of the most commonly used herbicides worldwide, has been considered as minimally toxic to humans. However, clinical toxicologists occasionally encounter cases of severe systemic toxicity. The US Environmental Protection Agency (EPA) states that 'GlySH' is of relatively low oral and acute dermal toxicity. It does not have anticholinesterase effect and no organophosphate-like central nervous system (CNS) effects. The clinical features range from skin and throat irritation to hypotension and death. Severe GlySH-surfactant poisoning is manifested by gastroenteritis, respiratory disturbances, altered mental status, hypotension refractory to the treatment, renal failure, and shock.[1] GlySH intoxication has a case fatality rate 3.2-29.3%. Pulmonary toxicity and renal toxicity seem to be responsible for mortality. Metabolic acidosis, abnormal chest X-ray, arrhythmias, and elevated serum creatinine levels are useful prognostic factors for predicting GlySH mortality.[2] There is no antidote and the mainstay of treatment for systemic toxicity is decontamination and aggressive supportive therapy. We report a case of acute pulmonary edema, which is a rare but severe manifestation of oral GlySH poisoning, where patient survived with aggressive supportive therapy. PMID:25948977

  16. Creature co-op: Achieving robust remote operations with a community of low-cost robots

    NASA Technical Reports Server (NTRS)

    Bonasso, R. Peter

    1990-01-01

    The concept is advanced of carrying out space based remote missions using a cooperative of low cost robot specialists rather than monolithic, multipurpose systems. A simulation is described wherein a control architecture for such a system of specialists is being investigated. Early results show such co-ops to be robust in the face of unforeseen circumstances. Descriptions of the platforms and sensors modeled and the beacon and retriever creatures that make up the co-op are included.

  17. Structure, Properties, and Theoretical Electronic Structure of UCuOP and Np3S5.

    SciTech Connect

    Wells, Daniel M.; Ringe, Emilie; Kaczorowski, D.; Gnida, D.; Andre, G.; Haire, Richard {Dick} G; Ellis, Donald E.; Ibers, James A.

    2010-01-01

    The compounds UCuOP and NpCuOP have been synthesized and their crystal structures were determined from low-temperature single-crystal X-ray data. These isostructural compounds crystallize with two formula units in space group P4/nmm of the tetragonal system. Each An atom (An = U or Np) is coordinated to four O and four P atoms in a distorted square antiprism; each Cu atom is coordinated to four P atoms in a distorted tetrahedron. Magnetic susceptibility measurements on crushed single crystals indicate that UCuOP orders antiferromagnetically at 224(2) K. Neutron diffraction experiments at 100 and 228 K show the magnetic structure of UCuOP to be type AFI ( - -) where ferromagnetically aligned sheets of U atoms in the (001) plane order antiferromagnetically along [001]. The electrical conductivity of UCuOP exhibits metallic character. Its electrical resistivity measured in the ordered region with the current flowing within the tetragonal plane is governed by the scattering of the conduction electrons on antiferromagnetic spin-wave excitations. The electrical resistivity of single-crystalline NpCuOP shows semimetallic character. It is dominated by a pronounced hump at low temperatures, which likely arises owing to long-range magnetic ordering below about 90 K. Density of state analyses using the local spin-density approximation show covalent overlap between AnO and CuP layers of the structure and dominant contributions from 5f-actinide orbitals at the Fermi level. Calculations on a 2 2 2 supercell of NpCuOP show ferromagnetic ordering within the Np sheets and complex coupling between these planes. Comparisons of the physical properties of these AnCuOP compounds are made with those of the family of related tetragonal uranium phosphide compounds.

  18. OpEx - a validated, automated pipeline optimised for clinical exome sequence analysis

    PubMed Central

    Ruark, Elise; Münz, Márton; Clarke, Matthew; Renwick, Anthony; Ramsay, Emma; Elliott, Anna; Seal, Sheila; Lunter, Gerton; Rahman, Nazneen

    2016-01-01

    We present an easy-to-use, open-source Optimised Exome analysis tool, OpEx (http://icr.ac.uk/opex) that accurately detects small-scale variation, including indels, to clinical standards. We evaluated OpEx performance with an experimentally validated dataset (the ICR142 NGS validation series), a large 1000 exome dataset (the ICR1000 UK exome series), and a clinical proband-parent trio dataset. The performance of OpEx for high-quality base substitutions and short indels in both small and large datasets is excellent, with overall sensitivity of 95%, specificity of 97% and low false detection rate (FDR) of 3%. Depending on the individual performance requirements the OpEx output allows one to optimise the inevitable trade-offs between sensitivity and specificity. For example, in the clinical setting one could permit a higher FDR and lower specificity to maximise sensitivity. In contexts where experimental validation is not possible, minimising the FDR and improving specificity may be a preferable trade-off for slightly lower sensitivity. OpEx is simple to install and use; the whole pipeline is run from a single command. OpEx is therefore well suited to the increasing research and clinical laboratories undertaking exome sequencing, particularly those without in-house dedicated bioinformatics expertise. PMID:27485037

  19. OpEx - a validated, automated pipeline optimised for clinical exome sequence analysis.

    PubMed

    Ruark, Elise; Münz, Márton; Clarke, Matthew; Renwick, Anthony; Ramsay, Emma; Elliott, Anna; Seal, Sheila; Lunter, Gerton; Rahman, Nazneen

    2016-01-01

    We present an easy-to-use, open-source Optimised Exome analysis tool, OpEx (http://icr.ac.uk/opex) that accurately detects small-scale variation, including indels, to clinical standards. We evaluated OpEx performance with an experimentally validated dataset (the ICR142 NGS validation series), a large 1000 exome dataset (the ICR1000 UK exome series), and a clinical proband-parent trio dataset. The performance of OpEx for high-quality base substitutions and short indels in both small and large datasets is excellent, with overall sensitivity of 95%, specificity of 97% and low false detection rate (FDR) of 3%. Depending on the individual performance requirements the OpEx output allows one to optimise the inevitable trade-offs between sensitivity and specificity. For example, in the clinical setting one could permit a higher FDR and lower specificity to maximise sensitivity. In contexts where experimental validation is not possible, minimising the FDR and improving specificity may be a preferable trade-off for slightly lower sensitivity. OpEx is simple to install and use; the whole pipeline is run from a single command. OpEx is therefore well suited to the increasing research and clinical laboratories undertaking exome sequencing, particularly those without in-house dedicated bioinformatics expertise. PMID:27485037

  20. Acute illness associated with use of pest strips - seven U.S. States and Canada, 2000-2013.

    PubMed

    Tsai, Rebecca J; Sievert, Jennifer; Prado, Joanne; Buhl, Kaci; Stone, Dave L; Forrester, Mathias; Higgins, Shelia; Mitchell, Yvette; Schwartz, Abby; Calvert, Geoffrey M

    2014-01-17

    Dichlorvos-impregnated resin strips (DDVP pest strips) are among the few organophosphate products still available for indoor residential use. The residential uses for most other organophosphate products, including most DDVP products, were canceled because they posed unreasonable risks to children. DDVP pest strips act by inhibiting acetylcholinesterase activity in the brain and nerves of insect pests and are designed to gradually release DDVP vapor for up to 4 months. Acute illnesses in humans associated with nonlethal acute exposures usually resolve completely, but recovery is not always rapid. To assess the frequency of acute illnesses associated with DDVP pest strips, cases from 2000 through June 2013 were sought from the 12 states that participate in the Sentinel Event Notification System for Occupational Risks (SENSOR)-Pe