Deep eutectic solvent-based pressurized liquid extraction combined with dispersive liquid-liquid microextraction of organophosphorus pesticide residues in egg powder prior to high-performance liquid chromatography analysis.

Herein, a deep eutectic solvent (DES)-based miniaturized pressurized liquid extraction in combination with DES-based dispersive liquid-liquid microextraction (DLLME) was developed for the extraction of organophosphorus pesticides (parathion-methyl, triazophos, parathion, diazinon, and phoxim) from egg powder samples prior to their analysis by a high-performance liquid chromatography-diode array detector. In this work, first, the analytes' extraction was done by a pressurized liquid phase extraction for effective extraction of the analytes from the solid matrix, and then they were concentrated on a DLLME for more concentration of the analytes to reach low limits of detections. The use of DESs was done in both steps to omit the use of toxic organic solvents. Satisfactory results including high extraction recoveries (74-90%), great repeatability (relative standard deviations equal or less than 4.3% and 5.3% for intra- and inter-day precisions), and low limits of detection (0.11-0.29 ng/g) and quantification (0.38-0.98 ng/g) were attained under the optimum conditions. Lastly, the suggested approach was utilized for the determination of the studied pesticides in various egg powder samples marketed in Tabriz, Iran.

TRPV4 modulation participates in paraoxon-induced brain injury via NMDA and NLRP3 regulation.

BACKGROUND: Organophosphorus pesticide poisoning can lead to severe brain damage, but the specific mechanisms involved are not fully understood. Our research aims to elucidate the function of the TRPV4 ion channel in the development of brain injury induced by paraoxon (POX). METHODS: In vivo, we examined the survival rate, behavioral seizures, histopathological alterations, NMDA receptor phosphorylation, as well as the expression of the NLRP3-ASC-caspase-1 complex and downstream inflammatory factors in the POX poisoning model following intervention with the TRPV4 antagonist GSK2193874. In vitro, we investigated the effects of GSK2193874 on NMDA-induced inward current, cell viability, cell death rate, and Ca2+ accumulation in primary hippocampal neurons. RESULTS: The treatment with the TRPV4 antagonist increased the survival rate, suppressed the status epilepticus, improved pathological damage, and reduced the phosphorylation level of NMDA receptors after POX exposure. Additionally, it inhibited the upregulation of NLRP3 inflammasome and inflammatory cytokines expression after POX exposure. Moreover, the TRPV4 antagonist corrected the NMDA-induced increase in inward current and cell death rate, decrease in cell viability, and Ca2+ accumulation. CONCLUSION: TRPV4 participates in the mechanisms of brain injury induced by POX exposure through NMDA-mediated excitotoxicity and NLRP3-mediated inflammatory response.

Multifunctional 2D hemin-bridged MOF for the efficient removal and dual-mode detection of organophosphorus pesticides.

The high-residual and bioaccumulation property of organophosphorus pesticides (OPs) creates enormous risks towards the ecological environment and human health, promoting the research for smart adsorbents and detection methods. Herein, 2D hemin-bridged MOF nanozyme (2D-ZHM) was fabricated and applied to the efficient removal and ultrasensitive dual-mode aptasensing of OPs. On the one hand, the prepared 2D-ZHM contained Zr-OH groups with high affinity for phosphate groups, endowing it with selective recognition and high adsorption capacity for OPs (285.7 mg g-1 for glyphosate). On the other hand, the enhanced peroxidase-mimicking biocatalytic property of 2D-ZHM allowed rapid H2O2-directed transformation of 3,3',5,5'-tetramethylbenzidine to oxidic product, producing detectable colorimetric or photothermal signals. Using aptamers of specific recognition capacity, the rapid quantification of two typical OPs, glyphosate and omethoate, was realized with remarkable sensitivity and selectivity. The limit of detections (LODs) of glyphosate were 0.004 nM and 0.02 nM for colorimetric and photothermal methods, respectively, and the LODs of omethoate were 0.005 nM and 0.04 nM for colorimetric and photothermal methods, respectively. The constructed dual-mode aptasensing platform exhibited outstanding performance for monitoring OPs in water and fruit samples. This work provides a novel pathway to develop MOF-based artificial peroxidase and integrated platform for pollutant removal and multi-mode aptasensing.

A molecularly imprinted electrochemical sensor MIP/Cu-MOF/rGO/AuNPs/GCE for highly sensitive detection of electroneutral organophosphorus pesticide residues.

A novel electrochemical sensor, MIP/Cu-MOF/rGO/AuNPs/GCE, was developed by depositing gold nanoparticles, coating Cu-MOF/GO on the surface of glassy carbon electrode (GCE) before electroreducing graphene oxide (GO) to rGO and covering molecularly imprinted membrane by electropolymerization for highly sensitive detection of electroneutral organophosphorus pesticide residues in agricultural product. Cyclic voltammetry, differential pulse voltametry, scanning electron microscopy, energy-dispersive spectroscopy, and atomic force microscopy were used to characterize the imprinted sensor. Several key factors such as chitosan concentration, suspension volume, pH of polymerization solution, and polymerization scanning rate during preparation of the imprinted sensor were optimized in detail. When electroneutral phosmet was used as a template, the linear range of MIP/Cu-MOF/rGO/AuNPs/GCE for detecting phosmet was 1.00 × 10-14-5.00 × 10-7 mol/L with the limit of detection of 7.20 × 10-15 mol/L at working potentials of - 0.2 to 0.6 V. The selectivity, reproducibility, and repeatability of MIP/Cu-MOF/rGO/AuNPs/GCE were all acceptable. The recoveries of this method for determining phosmet in real samples ranged from 94.2 to 106.5%. The MIP/Cu-MOF/rGO/AuNPs/GCE sensor could be applied to detect electroneutral pesticide residues in organisms and agricultural products.

Flow-through electrochemical organophosphorus degradation and phosphorus recovery: The essential role of chlorine radical.

Phosphorus scarcity and the deleterious ecological impact of the release of organophosphorus pesticides have emerged as critical global issues. Previous research has shown the ability of electrochemistry to induce the precipitation of calcium phosphate from phosphorus-laden wastewater to recover the phosphorus. The current study presents a flow-through electrochemical system consisting of a column-shaped electrochemical reactor, a tubular stainless-steel (SS) cathode, and a titanium suboxides (TiSO) anode. This system simultaneously oxidizes tetrakis (hydroxymethyl) phosphonium sulfate (THPS) and recycles phosphates. The influence of current density, flow rate, and initial calcium ions concentration were examined under continuous flow operation. To enhance the electrochemical reactor's performance, we elevated the current density from 5 to 30 mA cm-2, which caused the phosphorus recovery efficiency to increase from 37% to 72% within 120 min, accompanied by an enhancement of the THPS mineralization efficiency from 57% to 90%. These improvements were likely due to the higher yield of reactive species chloride species (Cl•) formed at the TiSO anode and the higher local pH at the cathode. By investigating the formation of Cl• at the TiSO anode, we found that THPS mineralization exceeded 75% in the presence of NaCl at a current density of 20 mA cm-2. The demonstrated performance of the flow-through electrochemical system should enable the utilization of anodic oxidation-cathodic precipitation for the recovery of phosphorus from organophosphorus-contaminated wastewater.

A Laser-Induced Graphene-Based Sensor Modified with CeO2 for Determination of Organophosphorus Pesticides with Improved Performance.

In this work, a flexible electrochemical sensor was developed for the detection of organophosphorus pesticides (OPs). To fabricate the sensor, graphene was generated in situ by laser-induced graphene (LIG) technology on a flexible substrate of polyimide (PI) film to form a three-electrode array, and pralidoxime (PAM) chloride was used as the probe molecule. CeO2 was used to modify the working electrode to improve the sensitivity of the sensor because of its electrocatalytic effect on the oxidation of PAM, and the Ag/AgCl reference electrode was prepared by the drop coating method. The effects of the laser power, laser scanning speed, and CeO2 modification on the electrochemical properties of the sensor were studied in detail. The results prove that the sensor has good repeatability, stability, and anti-interference ability, and it shows an excellent linear response in the chlorpyrifos concentration range from 1.4 × 10-8 M to 1.12 × 10-7 M with the detection limit of 7.01 × 10-10 M.

Heterogeneous kinetics of the OH-initiated degradation of fenthion and parathion.

Fenthion and parathion are two representative kinds of organophosphorus pesticides and widely used in agriculture. They are directly or indirectly released into the atmosphere by spraying or volatilization processes. However, their heterogeneous reactivity toward OH radicals has not yet been well understood. Therefore, this work investigated the heterogeneous kinetics of the OH-initiated degradation of surface-bound fenthion and parathion using a flow reactor. The results showed that OH radicals played an important role in the atmospheric degradation of fenthion and parathion. Their average rate constants were (7.20 ± 0.77) × 10-12 and (10.40 ± 0.60) × 10-12 cm3/(mol· sec) at a relative humidity (RH) and temperature of 35% and 20 °C, respectively, suggesting that they have relatively short lifetimes in the atmosphere. In addition, a negative RH dependence and a positive temperature dependence of the rate constants were observed. The Arrhenius expressions of fenthion and parathion were k2 = (1.34 ± 0.48) × 10-9exp[-(1432.59 ± 105.29)/T] and k2 = (1.96 ± 1.38) × 10-9exp[-(1619.98 ± 222.02)/T], respectively, and their overall activation energy was estimated to be (11.88 ± 0.87) and (13.48 ± 1.83) kJ/mol. The experimental results will update the kinetic data of fenthion and parathion in the atmosphere and be helpful to further understand their atmospheric transportation processes.

Peptide nanotube functionalized molecularly imprinted polydopamine based single-use sensor for impedimetric detection of malathion.

In the present study, a peptide nanotube functionalized polydopamine (p-Dop) based molecularly imprinted (MIP) sensor system was constructed, characterized, and studied for the impedimetric sensing of an organophosphorus pesticide, malathion (MLT). Electropolymerization in the presence of a template (MLT) was utilized as a convenient and effective strategy to generate imprinted p-Dop films on peptide nanotubes (PNTs) modified graphite electrodes (PGEs). Upon the removal of template, the adsorption of MLT on the specific cavities formed in the MIP film was tracked using electrochemical impedance spectroscopy (EIS). To attain optimal sensor response, experimental conditions, such as film thickness, analyte/functional monomer ratio, and desorption/adsorption time, were analyzed. The obtained MIP(p-Dop)-PNT-PGE sensor exhibited high sensitivity for electrochemical MLT analysis with a wide dynamic detection range of 13 pg mL-1 - 1.3 µg mL-1 and a LOD of 1.39 pg mL-1. The combination of a bio-inspired p-Dop-based MIP with the EIS technique allowed excellent sensitivity and selectivity toward MLT sensing which also yielded high recoveries in real samples. The success of this research strategy in real samples revealed its potential for various future environmental applications.

Prenatal organophosphorus pesticide exposure and executive function in preschool-aged children in the Norwegian Mother, Father and Child Cohort Study (MoBa).

INTRODUCTION: Prenatal exposure to organophosphorus pesticides (OPPs) has been associated with neurodevelopmental deficits in children, however evidence linking OPPs with specific cognitive mechanisms, such as executive function (EF), is limited. OBJECTIVE: This study aims to evaluate the association between prenatal exposure to OPPs with multiple measures of EF in preschool-aged children, while considering the role of variant alleles in OPP metabolism genes. METHODS: We included 262 children with preschool attention-deficit/hyperactivity disorder (ADHD), and 78 typically developing children, from the Preschool ADHD substudy of the Norwegian, Mother, Father, and Child Cohort Study. Participants who gave birth between 2004 and 2008 were invited to participate in an on-site clinical assessment when the child was approximately 3.5 years; measurements of EF included parent and teacher rating on Behavior Rating Inventory of Executive Function-Preschool (BRIEF-P), and three performance-based assessments. We measured OPP metabolites in maternal urines collected at ∼17 weeks' gestation to calculate total dimethyl- (ΣDMP) and diethyl phosphate (ΣDEP) metabolite concentrations. We estimated multivariable adjusted ß's and 95% confidence intervals (CIs) corresponding to a change in z-score per unit increase in log-ΣDMP/DEP. We further characterized gene-OPP interactions for maternal variants in PON1 (Q192R, M55L), CYP1A2 (1548T > C), CYP1A1 (IntG > A) and CYP2A6 (-47A > C). RESULTS: Prenatal OPP metabolite concentrations were associated with worse parent and teacher ratings of emotional control, inhibition, and working memory. A one log-∑DMP increase was associated with poorer teacher ratings of EF on the BRIEF-P (e.g. emotional control domain: ß = 0.55, 95% CI: 0.35, 0.74), when weighted to account for sampling procedures. We found less consistent associations with performance-based EF assessments. We found some evidence of modification for PON1 Q192R and CYP2A6 -47A > C. Association with other variants were inconsistent. CONCLUSIONS: Biomarkers of prenatal OPP exposure were associated with more adverse teacher and parent ratings of EF in preschool-aged children.

Interactions of organophosphorus pesticides with ATP-binding cassette (ABC) drug transporters.

Although pharmaceutical companies have to study drug-transporter interaction, environmental contaminant interactions with these transporters are not well characterised. In this study, we demonstrated using in vitro transfected cell line that some organophosphorus pesticides are able to interact with drug efflux transporters like P-glycoprotein, BCRP and MRPs.According to our results, dibrom was found to inhibit only Hoechst binding site of P-gp with an IC50 closed to 77 µM, phosmet inhibited BCRP efflux with an IC50 of 42 µM and only profenofos was able to inhibit BCRP, MRPs and P-gp at two binding sites. As profenofos appeared to be a potent ABC transporter inhibitor, we studied its potential substrate property towards P-gp.Using a docking approach, we developed an in silico tool to study pesticide properties to be a probe or inhibitor of P-gp transporter. From both in silico and in vitro results, profenofos was not considered as a P-gp substrate.Combining both in vitro and docking methods appears to be an attractive approach to select pesticides that would not pass into the blood systemic circulation.

Fluorescence Assay for Detecting Four Organophosphorus Pesticides Using Fluorescently Labeled Aptamer.

In this work, we reported a rapid and sensitive fluorescence assay in homogenous solution for detecting organophosphorus pesticides by using tetramethylrhodamine (TAMRA)-labeled aptamer and its complementary DNA (cDNA) with extended guanine (G) bases. The hybridization of cDNA and aptamer drew TAMRA close to repeated G bases, then the fluorescence of TAMRA was quenched by G bases due to the photoinduced electron transfer (PET). Upon introducing the pesticide target, the aptamer bound to pesticide instead of cDNA because of the competition between pesticide and cDNA. Thus, the TAMRA departed from G bases, resulting in fluorescence recovery of TAMRA. Under optimal conditions, the limits of detection for phorate, profenofos, isocarbophos, and omethoate were 0.333, 0.167, 0.267, and 0.333 µg/L, respectively. The method was also used in the analysis of profenofos in vegetables. Our fluorescence design was simple, rapid, and highly sensitive, which provided a means for monitoring the safety of agricultural products.

An Aptasensor Based on a Flexible Screen-Printed Silver Electrode for the Rapid Detection of Chlorpyrifos.

In this work, we propose a novel disposable flexible and screen-printed electrochemical aptamer-based sensor (aptasensor) for the rapid detection of chlorpyrifos (CPF). To optimize the process, various characterization procedures were employed, including Fourier transform infrared spectroscopy (FT-IR), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). Initially, the aptasensor was optimized in terms of electrolyte pH, aptamer concentration, and incubation time for chlorpyrifos. Under optimal conditions, the aptasensor showed a wide linear range from 1 to 105 ng/mL with a calculated limit of detection as low as 0.097 ng/mL and sensitivity of 600.9 µA/ng. Additionally, the selectivity of the aptasensor was assessed by identifying any interference from other pesticides, which were found to be negligible (with a maximum standard deviation of 0.31 mA). Further, the stability of the sample was assessed over time, where the reported device showed high stability over a period of two weeks at 4 °C. As the last step, the ability of the aptasensor to detect chlorpyrifos in actual samples was evaluated by testing it on banana and grape extracts. As a result, the device demonstrated sufficient recovery rates, which indicate that it can find application in the food industry.

[Determination of organophosphorus pesticide residues in milk of cows and sheep by ultra-high-performance liquid chromatography- tandem mass spectrometry combined with passing type purification method].

OBJECTIVE: A method for the rapid determination of dichlorvos, trichlorfon, fenthion, fenthion-sulfone, fenthion-sulfoxide, fenthion-oxon, fenthion-oxon-sulfone, fenthion-oxon-sulfoxide, phoxim, propetamphos, malathion, diazinon and coumaphos 13 common organophosphorus pesticides and their metabolites poison residues in milk of cows and sheep by ultra-high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) with passing type solid phase extraction(SPE) purification was developed. METHODS: After centrifugation at 4 ℃, the milk was purified by passing type SPE with acetonitrile precipitating protein and determined by UPLC-MS/MS in electrospray positive ion mode(ESI+) and multi-reaction monitoring scanning(MRM), external standard method for quantitative analysis with matrix matching standard curve. RESULTS: The recoveries of 13 target compounds were between 81.5% and 107.5% and relative standard deviation was between 1.24% and 6.23% at three spiked levels of 5, 10, 20 µg/L. The detection limits of 13 target compounds were between 0.015 and 0.15 µg/L, and the quantitative limits were between 0.05 and 0.50 µg/L. No organophosphorus pesticide residues were detected in 20 samples of cows and sheep milk. CONCLUSION: The method has the advantages of good linear independence, low detection limit, high precision and accuracy, and can be used for daily monitoring of milk and related products.

[The value of renal color Doppler ultrasound in evaluating the severity and prognosis of patients with acute organophosphorus pesticide poisoning complicated by acute kidney injury].

Objective: To analyze the value of renal color Doppler ultrasound examination and clinical indicators in evaluating the severity and prognosis of acute organophosphorus pesticide poisoning (AOPP) complicated by acute kidney injury (AKI) . Methods: In November 2019, 86 AOPP patients complicated by AKI who were admitted from May 2018 to May 2019 were selected as the observation group, and they were divided into AKI stage 1 group (n=37) , AKI stage 2 group (n=32) and AKI stage 3 group (n=17) . 40 healthy people were selected as the control group. The differences in power Doppler ultrasound (PDU) score, renal interlobular artery resistance index (RI) value and related clinical indicators of each group were measured and analyzed, and the correlations between the indicators were analyzed. At the same time, binary logistic regression was used to analyze the risk factors of death in AOPP patients complicated by AKI. Results: There were statistically significant differences in Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱscore, mean arterial pressure (MAP) , serum creatinine (SCr) and the length of continuous renal replacement therapy (CRRT) between different groups (P<0.05) . Compared with the control group, the APACHE Ⅱscores and SCr of patients in the AKI stage 2 and resistance index AKI stage 3 groups increased, while the MAP decreased (P<0.05) . Compared with the control group, AKI stage 1 group and AKI stage 2 group, the PDU score of patients in the AKI stage 3 group was significantly decreased, and the renal interlobular artery RI value was significantly increased (P<0.05) . SCr was positively correlated with the RI value of renal interlobular arteries and CRRT days (r=0.435, 0.713, P<0.05) , and was negatively correlated with renal PDU score (r=-0.643, P<0.05) . The renal PDU score was negatively correlated with the RI value of renal interlobular arteries and CRRT days (r=-0.350, -0.556, P<0.01) . Binary logistic regression analysis showed that SCr (OR=1.017, 95%CI: 1.004-1.041) and APACHE Ⅱ score (OR=1.289, 95%CI: 1.019-1.827) were risk factors for death in patients with AOPP complicated by AKI (P<0.05) . Conclusion: Both PDU score and the RI value of renal interlobular artery can reflect the severity and stage of patients with AOPP complicated by AKI to a certain extent, but neither of them is a key factor affecting the death of patients.

A turn-on fluorescent nanoprobe based on N-doped silicon quantum dots for rapid determination of glyphosate.

N-Doped silicon quantum dots (N-SiQD) were synthesized using N-[3-(trimethoxysily)propyl]-ethylenediamine and citric acid as silicon source and reduction agent, respectively. The N-SiQD shows a strong blue fluorescence with a high quantum yield of about 53%. It is found that a selective static quenching process occurs between N-SiQDs and Cu2+. Glyphosate can inhibit this phenomenon and trigger the rapid fluorescence enhancement of the quenched N-SiQDs/Cu2+ system due to the specific interaction between Cu2+ and glyphosate. With such a design, a turn-on fluorescent nanoprobe based on N-SiQD/Cu2+ system was established for rapid determination of glyphosate. The determination signal of N-SiQD/Cu2+ was measured at the optimum emission wavelength of 460 nm after excitation at 360 nm. Under optimal conditions, the turn-on nanoprobe showed a linear relationship between fluorescent response and glyphosate concentrations in the range 0.1 to 1 µg mL-1. The limit of determination was calculated to 7.8 ng mL-1 (3σ/S). Satisfactory recoveries were obtained in the determination of spiked water samples, indicating the potential use for environmental monitoring. Graphical abstract Schematic representation of N-SiQD/Cu2+ system for glyphosate determination. Fluorescence quenching of N-SiQDs induced by copper ions and the succedent fluorescent "turn on" triggered by glyphosate.

Quinolone and Organophosphorus Insecticide Residues in Bivalves and Their Associated Risks in Taiwan.

Bivalves, such as freshwater clams (Corbicula fluminea) and hard clams (Meretrix lusoria), are the most extensive and widely grown shellfish in land-based ponds in Taiwan. However, few studies have examined the contamination of bivalves by quinolone and organophosphorus insecticides. Thus, we adapted an established procedure to analyze 8 quinolones and 12 organophosphorus insecticides using liquid and gas chromatography-tandem mass spectrometry. Surveys in Taiwan have not noted high residual levels of these chemicals in bivalve tissues. A total of 58 samples of freshwater or hard clams were obtained from Taiwanese aquafarms. We identified 0.03 mg/kg of enrofloxacin in one freshwater clam, 0.024 mg/kg of flumequine in one freshwater clam, 0.02 mg/kg of flumequine in one hard clam, 0.05 mg/kg of chlorpyrifos in one freshwater clam, 0.03 mg/kg of chlorpyrifos in one hard clam, and 0.02 mg/kg of trichlorfon in one hard clam. The results indicated that 5.17% of the samples had quinolone insecticide residues and 5.17% had organophosphorus residues. However, the estimated daily intake (EDI)/acceptable daily intake quotient (ADI) indicated no significant risk and no immediate health risk from the consumption of bivalves. These results provide a reference for the food-safety screening of veterinary drugs and pesticides in aquatic animals. Aquatic products should be frequently screened for residues of prohibited chemicals to safeguard human health.

Occurrence and potential risk of organophosphorus pesticides in urbanised Linggi River, Negeri Sembilan, Malaysia.

The application of organophosphorus pesticides (OPPs) increased gradually because of the rise in global food demand that triggered the agriculture sector to increase the production, leading to OPP residues in the surface water. This study elucidated the presence of OPPs and estimated its ecological risk in the riverine ecosystem of the urbanised Linggi River, Negeri Sembilan, Malaysia. The OPP concentration in surface water was determined using solid-phase extraction method and high-performance liquid chromatography coupled with diode array detection. Further, the ecological risk was estimated by using the risk quotient (RQ) method. The three OPPs, i.e. chlorpyrifos, diazinon, and quinalphos were detected with mean concentrations of 0.0275 µg/L, 0.0328 µg/L, and 0.0362 µg/L, respectively. The OPPs were at high risk (in general and worst cases) under acute exposure. The estimated risk of diazinon was observed as medium for general (RQm = 0.5857) and high for worst cases (RQex = 4.4678). Notably, the estimated risk for chlorpyrifos was high for both general and worst cases (RQm = 1.9643 and RQex = 11.5643) towards the aquatic ecosystem of the Linggi River. Chronic risk of quinalphos remains unknown because of the absence of toxicity endpoints. This study presented clear knowledge regarding OPP contamination and possible risk for aquatic ecosystems. Hence, OPPs should be listed as one of the main priority contaminants in pesticide mitigation management in the future.

A simple spectroscopic method to determine dimethoate in water samples by complex formation.

A simple and rapid method for the determination of dimethoate in water was developed based on the monitoring of the complex formation between bis 5-phenyldipyrrinate of nickel (II) and the herbicide dimethoate. The method showed a short response time (10 s), high selectivity (very low interference from other sulfate and salts), high sensitivity (limit of detection (LOD) 0.45 µM, limit of quantitation (LOQ) of 1.39 µM), and a Kd of 2.4 µM. Stoichiometry experiments showed that complex formation occurred with a 1:1 relation. The method was applied to different environmental water samples such as lagoon, stream, urban, and groundwater samples. The results indicated that independently from the water source, the method exhibited high precision (0.25-2.47% variation coefficient) and accuracy (84.42-115.68% recovery). In addition, the method was also tested using an effluent from a wastewater treatment plant from Mexico; however, the results indicated that the presence of organic matter had a pronounced effect on the detection.

Interactions of organophosphorus pesticides with solute carrier (SLC) drug transporters.

1. Organophosphorus pesticides (OPs) are known to interact with human ATP-binding cassette drug efflux pumps. The present study was designed to determine whether they can also target activities of human solute carrier (SLC) drug transporters. 2. The interactions of 13 OPs with SLC transporters involved in drug disposition, such as organic cation transporters (OCTs), multidrug and toxin extrusion proteins (MATEs), organic anion transporters (OATs) and organic anion transporting polypeptides (OATPs), were mainly investigated using transporter-overexpressing cell clones and fluorescent or radiolabeled reference substrates. 3. With a cut-off value of at least 50% modulation of transporter activity by 100 µM OPs, OAT1 and MATE2-K were not impacted, whereas OATP1B1 and MATE1 were inhibited by two and three OPs, respectively. OAT3 activity was similarly blocked by three OPs, and was additionally stimulated by one OP. Five OPs cis-stimulated OATP2B1 activity. Both OCT1 and OCT2 were inhibited by the same eight OPs, including fenamiphos and phosmet, with IC50 values however in the 3-30 µM range, likely not relevant to environmental exposure. 4. These data demonstrated that various OPs inhibit SLC drug transporter activities, especially those of OCT1 and OCT2, but only when used at high concentrations not expected to occur in environmentally-exposed humans.

Serum ubiquitin C-terminal hydrolase L1 predicts cognitive impairment in patients with acute organophosphorus pesticide poisoning.

BACKGROUND: To assess the usefulness of serum C-terminal hydrolase L1 (UCH-L1) level as a biomarker for predicting cognitive impairment in patients with acute organophosphorus pesticide poisoning (AOPP). METHODS: Two hundred and seven adult patients with AOPP were included in this study. Serum UCH-L1 levels were assessed on admission (Day 1 postpoisoning) and on Days 3 and 7 postpoisoning. The associations between serum UCH-L1 levels, other clinical predictors, and cognitive function evaluated on Day 30 postpoisoning were investigated. RESULTS: On multivariate analysis, serum UCH-L1 levels on admission (odds ratio [OR] 1.889, 95% confidence interval [CI] 1.609-3.082, P = 0.002) and 24-hour APACHE II score (OR 1.736, 95% CI 1.264-3.272, P = 0.012) were independent predictors of cognitive impairment on Day 30 postpoisoning. Based on the receiver operating characteristic curve, serum UCH-L1 levels >5.9 ng/mL on admission predicted cognitive impairment on Day 30 postpoisoning with 86.1% sensitivity and 72.5% specificity (area under the curve, 0.869; 95% CI 0.815-0.923). On admission [8.51 (6.53-10.22) ng/mL vs 4.25 (2.57-6.31) ng/mL, P < 0.001] and Day 3 [9.31 (7.92-10.98) ng/mL vs 3.32 (2.25-5.13) ng/mL, P < 0.001] and Day 7 [4.96 (3.28-7.26) ng/mL vs 2.27 (1.55-3.24) ng/mL, P < 0.001] postpoisoning, serum UCH-L1 concentration was significantly higher in patients that developed cognitive impairment compared to those that did not. CONCLUSION: This study demonstrates that serum UCH-L1 level has potential as a novel biomarker for predicting cognitive impairment 30 days after AOPP.