Blood Cholinesterase Activity Research Articles

Pesticide exposure and blood cholinesterase levels among adolescents from farming families in Northern Thailand.

Adolescents living in agricultural communities may be at risk for the adverse effects of pesticide exposure because they are involved in agriculture either as a career or to support their families. The purpose of this study was to investigate the association of farm activities related to pesticide exposure on blood cholinesterase (ChE) levels among adolescents from farming families in the north of Thailand. This cross-sectional study included 336 adolescents aged 12-19 years from farming families in Chiang Dao District, Chiang Mai Province. Data on pesticide exposure was collected using a questionnaire, and blood ChE activity was assessed using a ChE reactive paper test kit via fingerstick blood sampling. Overall, 51.2% of participants had abnormal blood ChE levels. Univariable logistic regression analysis revealed that pesticide-related activities on farms associated with abnormal ChE levels were mixing/spraying (OR=10.54; 95%CI=4.63-23.99), assisting or working in areas with pesticide application (OR=5.54; 95%CI=3.45-8.89), and harvesting (OR=3.70; 95%CI=2.35-5.82). In a multivariable model (Nagelkerke R2=0.374), mixing/spraying (OR=4.90; 95%CI=2.03-11.83) and assisting or working in areas with pesticide application (OR=2.61; 95%CI=1.49-4.57) were significantly associated with abnormal ChE levels, but harvesting (OR=1.48; 95%CI=0.84-2.61) was not significant after adjusting for sex, age in years, and entering or walking through a farm. The findings indicated that Thai adolescents living in farming families are at risk of pesticide exposure, particularly those involved in agricultural activities such as pesticide applicators. An intervention and measure to raise awareness and reduce the risk of pesticide exposure in adolescents is required.

Assessing the effectiveness, biosafety, and resident’s perception of a micro-encapsulated propoxur paint against Aedes aegypti: a field trial in a dengue-affected community of Sonora, Mexico

Mosquito-borne diseases remain a major public health concern in the Region of the Americas. Concerning dengue, Mexico ranked as the third American country with the highest number of cases in 2023, following Brazil and Peru. In this sense, the development and production of safer, eco-friendly, cost-effective, more efficient, and target-specific insecticides have become essential in disease control strategies. This study aimed to assess the effectiveness and safety of indoor micro-encapsulated propoxur paint against Aedes aegypti, estimate residents' exposure via cholinesterase levels, and gauge resident perceptions in the rural village Poblado Miguel Alemán (PMA), Sonora, Mexico. Houses in PMA were organised into four blocks for a field trial, with different treatments on interior walls: 1) full insecticide paint coverage; 2) insecticide paint applied up to 1 meter; 3) full indoor residual spraying; and 4) no treatment (control). Mosquito surveys were conducted before and after interventions. Blood samples from residents were analysed for cholinesterase levels, while perceptions were gathered through a questionnaire. Aedes resting density correlated closely with the paint formulation and coverage. Full-surface insecticide paint showed the greatest reduction. Both paint interventions notably impacted Aedes breeding, with substantial reductions in House Index (20.1% IP, 31.2% IP 1 m) and Container Index (51.8% IP, 61.7% IP 1 m) compared to the control over one year. Post-intervention blood cholinesterase activity remained within acceptable limits. Over 80% of residents expressed satisfaction with the interventions. The use of propoxur paint proves to be a safe, effective, and well-accepted method for decreasing Ae. aegypti populations in urban areas.

Baseline physiological data from anesthetized pigs in a VX intoxication model

Over the past fifty years, swine models have been used for organophosphorus intoxication studies. Among these studies and others on the swine model in general, some physiological data, especially cholinesterase activity highly impacted by organophosphorus compounds like nerve agent VX, still need to be completed. To support and compare our model to others, we have published the experimental protocol, the physiological values of 31 juvenile anesthetized pigs, and the 6 h-follow-up of six supplementary anesthetized control animals and 7 VX-intoxicated pigs. We reported hemodynamics and respiratory parameters, blood levels in several biochemical parameters, blood gas, and complete blood count and compared them to the literature. We also focused on tissue and blood cholinesterase activities and detailed them for acetylcholinesterase and butyrylcholinesterase. After establishing a broad physiological data set consistent with the literature, we reported several cardio-respiratory parameters that seem more affected by an organophosphate intoxication, like heart rate, arterial blood pressure, cardiac output, and respiratory rate. Within the blood, oxygen saturation (SpO2), lactatemia, base excess, and glycemia can also be measured and associated with the other parameters to evaluate the life-threatening status. This swine model is currently used to develop and evaluate medical countermeasures against organophosphate nerve agent intoxications.

Relationship Between Pesticide Exposure Factors and Health Symptoms Among Chili Farmers in Northeast Thailand.

The unsafe use of pesticides in agriculture represents a major hazard to human health. This study was conducted to investigate the association between pesticide exposure and health symptoms among chili farmers in northeast Thailand. This cross-sectional analytic study included 141 chili farmers in Sakon Nakhon Province, in northeast Thailand. Data regarding health symptoms were gathered using a self-report questionnaire. A medical technician tested blood cholinesterase activity using an erythrocyte method, and an occupational medicine specialist at Ramathibodi Hospital in Bangkok, Thailand reviewed the results. Associations between personal characteristics, pesticide exposure factors, and health symptoms were analyzed using multiple logistic regression. Of the 141 chili farmers studied, 66.7% experienced pesticide poisoning, as indicated by below-normal cholinesterase levels. Fatigue was the most frequently reported symptom associated with pesticide exposure, affecting 37.6% of participants. This was followed by nausea and vomiting (31.9%), dizziness (14.9%), and dry throat (14.9%). Multivariate logistic regression analysis revealed that several factors were significantly associated with adverse symptoms: amount of work experience, volume of pesticides used, use of chemical pesticides, use of leaking containers during spraying, direct pesticide exposure while working, contact with pesticide-soaked clothing, consumption of food and drinks in the fields, and blood cholinesterase level indicating risk. This study suggests potential health risks for chili farmers stemming from exposure to and contamination by pesticides used in agricultural practices. To mitigate these risks, it is essential to supply personal protective equipment and to implement educational programs aimed at improving protective behaviors among farmers.

Effects of concomitant use of THC and irinotecan on tumour growth and biochemical markers in a syngeneic mouse model of colon cancer.

Clinical treatment with the antineoplastic drug irinotecan (IRI) is often hindered by side effects that significantly reduce the quality of life of treated patients. Due to the growing public support for products with Δ9-tetrahydrocannabinol (THC), even though relevant scientific literature does not provide clear evidence of their high antitumour potential, some cancer patients take unregistered preparations containing up to 80 % THC. This study was conducted on a syngeneic colorectal cancer mouse model to test the efficiency and safety of concomitant treatment with IRI and THC. Male BALB/c mice subcutaneously injected with CT26 cells were receiving 60 mg/kg of IRI intraperitoneally on day 1 and 5 of treatment and/or 7 mg/kg of THC by gavage a day for 7 days. Treatment responses were evaluated based on changes in body, brain, and liver weight, tumour growth, blood cholinesterase activity, and oxidative stress parameters. Irinotecan's systemic toxicity was evidenced by weight loss and high oxidative stress. The important finding of this study is that combining THC with IRI diminishes IRI efficiency in inhibiting tumour growth. However, further studies, focused on more subtle molecular methods in tumour tissue and analytical analysis of IRI and THC distribution in tumour-bearing mice, are needed to prove our observations.

"Catch-up" therapy: combining antidotal treatment with dermal application of AHA following percutaneous VX poisoning in the domestic swine.

Low-volatility organophosphorus chemical warfare agents (OP CWAs) are cholinesterase inhibitors which easily absorb into the skin, leading to the formation of a dermal depot from which they slowly enter the bloodstream. This leads to sustained cholinergic hyperstimulation, which if untreated may lead to death. However, current available countermeasures are not adequate to neutralize the agent residing in the dermal depot. Accordingly, we evaluated the efficacy of the potassium salt of acetohydroxamic acid (880 mg/ml in DMSO/H2O 1:4, AHAK), as a potential "catch-up" therapy lotion intended to neutralize the dermal depot, by penetrating the skin and decomposing it before it reaches the bloodstream. To that end, we compared the clinical outcome following skin surface decontamination combined with antidotal treatment, to that following the same antidotal treatment combined with dermal application of AHAK at the site of VX exposure, against percutaneous poisoning by a lethal neat dose (4 mg/kg) of the low-volatility nerve agent VX, in an unanesthetized swine model. Following skin surface decontamination and antidotal treatment, recurrence of intoxication signs and a prolonged recovery time were observed. In contrast, similar antidotal treatment combined with dermal application of AHAK significantly reduced intoxication signs recurrences and accordingly medical supervision duration needed, paralleled by a significantly faster recovery of whole blood cholinesterase activity. An initial evaluation demonstrated the safety of prolonged whole-body AHAK application. Hence, the AHAK lotion may act as an efficient "catch-up" therapy against percutaneous poisoning by low-volatility OP CWAs, improving the clinical outcome and reducing the burden on medical staff.

In Vitro Inhibition of Blood Cholinesterase Activities by Dichlorvos in Farmworkers Previously Exposed to Pesticides

In Vitro Inhibition of Blood Cholinesterase Activities by Dichlorvos in Farmworkers Previously Exposed to Pesticides

Changes in blood oxidative stress biomarker and cholinesterase activity after general vs spinal anesthesia for elective cesarean sections

Background & Objective: There is an increased ratio of cesarean sections (CS) compared to normal deliveries the world over. Both general and regional anesthetic techniques are in practice for CS. Limited information is available on the determination of blood cholinesterase (ChE) activity in conjunction with oxidative stress biomarkers after the CS. The purpose of the present study was to determine and compare the plasma and erythrocyte ChE activity as well as malondialdehyde (MDA) level and total antioxidant status in pregnant women before anesthesia and after the use of general anesthesia (GA) or spinal anesthesia (SA) for elective CS.
 Methodology: A pre-post study was conducted on 102 full-term pregnant women, who underwent elective CS in four hospitals at Duhok (Iraq) from January 2022 to July 2022. GA with propofol and SA with bupivacaine 0.5% were administered to 52 and 50 women, respectively. Maternal blood samples before anesthesia and after the completion of operation were assayed for the ChE activity in the plasma and erythrocytes, and plasma oxidative stress biomarkers malondialdehyde and total antioxidant status.
 Results: Plasma ChE activity significantly decreased in the GA and SA groups after the cesarean-deliveries compared to the corresponding pre-anesthetic values. The plasma MDA level in both GA and SA groups, but not the total antioxidant status, was significantly reduced. Estimation of the odds ratio and the relative risk indicated that a risk factor is associated with the reduced plasma ChE activity in women after the CS when the general anesthetic propofol is used.
 Conclusion: Both general anesthesia with propofol and spinal anesthesia with bupivacaine inhibited plasma cholinesterase activity and reduced oxidative stress biomarker malondialdehyde after the cesarean sections.
 Abbreviations: CS - Cesarean section; ChE: Cholinesterase; EChE: Erythrocyte Cholinesterase; MDA: Malondialdehyde; OS: Oxidative Stress; PChE: Plasma ChE; TAS: Total Antioxidant Status.
 Key words: Anesthesia, Spinal; Cesarean section; General anesthesia; Malondialdehyde; Oxidative stress
 Citation: Karam RS, Mohammad FK. Changes in blood oxidative stress biomarker and cholinesterase activity after general vs spinal anesthesia for elective cesarean sections. Anaesth. pain intensive care 2023;27(3):396−404; DOI: 10.35975/apic.v27i3.2244
 Received: March 23, 2023; Reviewed: May 06, 2023; Accepted: May 09, 2023

In a secondary analysis from a randomised, double-blind placebo-controlled trial Dexmedetomidine blocks cholinergic dysregulation in delirium pathogenesis in patients with major surgery

Dexmedetomidine is an alpha-2 adrenoreceptor agonist with anti-inflammatory and anti-delirogenic properties. Pathogenesis of postoperative delirium (POD) includes cholinergic dysfunction and deregulated inflammatory response to surgical trauma. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are discussed as biomarkers for both POD and severity in acute inflammation. To show whether there is a link between blood cholinesterase activities and dexmedetomidine, we performed a secondary analysis of a randomised, double-blind, placebo-controlled trial that recently showed a lower incidence of POD in the dexmedetomidine group. Abdominal or cardiac surgical patients aged ≥ 60 years were randomised to receive dexmedetomidine or placebo intra- and postoperatively in addition to standard general anaesthesia. We analysed the course of perioperative cholinesterase activities of 56 patients, measured preoperatively and twice postoperatively. Dexmedetomidine resulted in no change in AChE activity and caused a rapid recovery of BChE activity after an initial decrease, while placebo showed a significant decrease in both cholinesterase activities. There were no significant between-group differences at any point in time. From these data it can be assumed that dexmedetomidine could alleviate POD via altering the cholinergic anti-inflammatory pathway (CAIP). We advocate for further investigations to show the direct connection between dexmedetomidine and cholinesterase activity.

A novel RP-HPLC method for quantification of cholinesterase activity in human blood: An application for assessing organophosphate and carbamate insecticide exposure.

Several methods have been reported to estimate Acetylcholinesterase (AChE) enzyme activity in blood samples. The Ellman assay is the most important among all but with several shortcomings, and there is a need to develop a method which is accurate, sensitive and quick for analyzing AChE. Therefore, we have developed an assay utilizing RP-HPLC with UV detection for the determination of AChE activity. This method measured the conversion of 1-naphthol acetate to 1-naphthol to estimate AChE activity in blood samples. Performance was judged on the basis of reproducibility, sensitivity, accuracy, and the ability to screen enzyme activity within 20minutes. A series of experiments were performed, varying the concentration of blood and substrate, with optimal sensitivity using 50 μM substrate and 10μL blood. The validation parameters such as linearity (R2 of ≥ 0.9842 for 1-naphthol and ≥ 0.9897 for 1-naphthol acetate), precision (94.21-96.41%), accuracy (85.2%-99.6% and 82.6%-99.3% for 1-naphthol and 1-naphthol acetate respectively), and robustness were validated according to International Conference on Harmonization (ICH) guidelines. Blood samples were collected from healthy people, farmers exposed to spraying of pesticides, and suicidal patients who ingested pesticides and were hospitalized and were analyzed by the developed method. The AChE level was approximately 21 units/mL compared to 24units/mL in controls, whereas suicidal patients showed the least AChE levels of 1 unit/mL. The employment of this method is recommended for estimating AChE level on various matrices.

Blood cholinesterase activities and oxidative stress status among farmworkers using pesticides in Duhok, KRG, Iraq

Background: The use of pesticides by farmworkers poses considerable health risks. This study was undertaken to examine plasma and erythrocyte cholinesterase activities, plasma oxidative biomarkers malondialdehyde (MDA), and total antioxidant status (TAS) among farmworkers using different pesticide products in Duhok, northern of Iraq. Methods: This is a case-control study conducted between November 2021 to July 2022 on 92 male farmworkers who were exposed to pesticides in comparison with 44 non-exposed male subjects (control). The availability and uses of pesticides were obtained from 19 agrochemical shops and the farmworkers exposed to pesticides. Demographic data of pesticide-exposed farmworkers and their practice of pesticide applications were recorded. Plasma and erythrocyte cholinesterase activities and plasma MDA and TAS levels were determined in both groups. Results: The farmworkers had a significant 10.0% increase in plasma MDA level, with no significant changes in blood cholinesterase activities or the TAS level. Odds and risk ratios of reduced plasma cholinesterase activity (20.0%) suggested an association of health risks in pesticide-exposed farmworkers. Most of the pesticide products (278) in use were insecticides (47.0%), which comprised mainly 26.0% pyrethroids and 3.0-7.0% anticholinesterase insecticides, among others. The majority of the farmworkers (51%) were merely aware of the general target use of the pesticide, and 75% had an exposure history of > 5 years. Pesticide application was mostly (50.0%) manual, and 54.0% used insufficient personal protection equipment; 32.0% ate and drank at work, 48.0% practiced disposal of empty pesticide containers by burning and/or burying them, whereas 25.0% dumped the containers indiscriminately, and 25% disposed them at garbage sites openly. Conclusion: The farmworkers, with only a marginal increase in oxidative stress biomarker MDA, did not suffer from significant reductions in blood cholinesterase activities, although odds and risk ratios of reduced plasma cholinesterase activity suggested a health risk. Implementation of a national program is needed to measure pre-exposure blood cholinesterase activities in farmworkers.

Toxicokinetics of plasmatic VX in a swine model: comparison of a simple enzymatic titration method with a mass spectrometry method.

Recent events have shown that organophosphorus nerve agents (OPNAs) are a serious threat. Cholinesterase inhibition by OPNAs results in acetylcholine accumulation, a cholinergic crisis leading to death if untreated. Efficacy assessment of new medical countermeasures against OPNAs relies on translational animal models. We developed a swine model of percutaneous VX intoxication and a simple plate reader-based enzymatic method to quantify plasmatic VX over time. Juvenile pigs anesthetized with sevoflurane were poisoned with a single supralethal (n = 5; 1200μg/kg) or sublethal (n = 6; 320μg/kg) percutaneous dose of VX. These intoxicated animals were compared to 7 control animals. Repeated blood sampling was performed up to 6h post-intoxication. Blood cholinesterase activities were measured using the Ellman assay. Nanomolar plasma concentrations of VX were measured by exogenous butyrylcholinesterase added to an aliquot of plasma. As expected, we observed a steady increase in plasma concentration of VX over time concomitant to a decrease in blood cholinesterase activities for all intoxicated pigs. Despite the simplicity of the enzymatic method, the results obtained are in good agreement with those of the liquid chromatography-mass spectrometry method. This method is also applicable to other OPNAs such as novichoks with minor adaptations.

Association of cholinesterase activities and POD in older adult abdominal surgical patients

BackgroundPostoperative delirium (POD) is a frequent complication after surgery. Older adult patients undergoing abdominal surgery are at higher risk for developing POD. Studies on the association of cholinesterase activities and POD are rare, but leading hypotheses implicate that the cholinergic pathway might play an important role in neuroinflammation and development of POD. The objective of this study was to figure out if there is an association between the development of POD and acetyl- and butyrylcholinesterase (AChE and BuChE) activities in older adult patients undergoing abdominal surgery.MethodsThe investigation was performed with a subpopulation of BioCog study patients. The BioCog project (http://www.biocog.eu) is a prospective multicenter observational study in older adult surgical patients. Patients ≥ 65 years undergoing elective surgery of at least 60 minutes who scored more than 23 points in the Mini-Mental-State-Examination were included. POD was assessed twice a day on seven consecutive days after the surgery, using the test instruments Nursing Delirium Screening Scale (Nu-Desc) and Confusion Assessment Method (CAM and CAM-ICU) and a patient chart review. Pre- and postoperative blood cholinesterase activities were measured with a photometric rapid-point-of-care-testing. The association between cholinesterase activities and POD was analyzed in a subpopulation of abdominal surgical patients using multivariable logistic regression analysis adjusting for confounders.ResultsOne hundred twenty-seven patients were included for analysis (mean age 73 years, 59% female). Fifty-two patients (41%) fulfilled the criteria of POD. These patients were significantly older, had a longer time of surgery and anesthesia and achieved higher comorbidity scores compared to patients without POD. After adjusting for age, duration of surgery and charlson comorbity index, we found an association between pre- and postoperative AChE activity (U/gHb) and the development of POD (Odds ratio (OR), [95% confidence interval (CI)], preoperative 0.95 [0.89–1.00], postoperative 0.94 [0.89–1.00]).ConclusionsWe found an association between POD and AChE activity and provided new information considering patients with abdominal surgery. Future analyses should examine course dynamics of postoperative cholinesterase activities in order to clarify interactions between the cholinergic system and pathophysiological mechanisms leading to POD.Trial registrationClinicalTrials.gov: NCT02265263.

MONITORING BLOOD CHOLINESTERASE ACTIVITY OF FARMWORKERS: IN VITRO INHIBITION BY DIPHENHYDRAMINE AND CARBARYL

Plasma and erythrocyte cholinesterase (ChE) activities of male farm workers exposed to pesticides during their routine work were lower than those of unexposed control subjects by 14 and 4%, respectively. Diphenhydramine and Carbaryl inhibited plasma and erythrocyte ChE activities in vitro in pesticide-exposed and unexposed subjects. The percentages of in vitro ChE inhibition induced by carbaryl in the plasma and erythrocytes of unexposed controls ranged between 47-85% and 19-47%, respectively, whereas they were 35-60% and 3-12% in the pesticide-exposed group, respectively. In vitro pretreatment of plasma and erythrocyte ChE with diphenhydramine (20 μM) significantly reduced the inhibitory effect of carbaryl (10 μM) on them by 18% and 10%, respectively. In conclusion, subjects exposed to pesticides during their routine work in agriculture are at risk of reduced blood ChE activity. Diphenhydramine appeared to partially protect blood ChE in vitro from additional carbaryl-induced enzyme inhibition in both pesticide-exposed and unexposed subjects.

Aldicarb-related suicide attempt cases in North of France (2012-2021).

Aldicarb, a carbamate pesticide banned in France since 2008, represents a persistent risk of human poisoning. There is no up-to-date picture of aldicarb intentional poisonings associated to detailed diagnosis and clinical management of cases to evaluate the effect of its ban on intoxication risk reduction, including suicide. This retrospective epidemiological study describes cases of suicidal intoxication from the Hauts-de-France region between 2012 and 2021 and illustrates this situation through one analytically documented case. 60 cases were collected, mostly presenting a pathognomonic symptomatology. Thirty-five victims presented a muscarinic syndrome (58.3%), 14 a nicotinic syndrome (23.3%), and 37 a central nervous system impairment (61.7%). Hospitalization was necessary for 44 cases (73.3%), with 2 fatal evolutions. Diagnosis was based on the blood cholinesterase activities. Among the 25 cases with toxicology results, 45.8% presented a moderate decrease of acetylcholinesterase activity, whereas 87.5% presented a strong decrease of butyrylcholinesterase activity. Blood or urine detection of aldicarb and its metabolites may be considered in therapeutic management, although their quantification is unlikely to change the emergency medical care. Our study updates epidemiology of aldicarb poisoning at a regional level, highlighting a persisting health threatening situation with banned pesticides. More than 65% of national cases occurred in this agricultural area, aldicarb remaining available from storage of previously purchased products. Robust evidence is presented that acute poisoning is an ongoing major global public health challenge. There is a need for continued international efforts in risk reduction, knowledge, and information strategies.

Risk evaluation of occupational exposure of southern Brazilian flower farmers to pesticides potentially leading to cholinesterase inhibition and metals exposure

This work presents a frequency matched observational study comparing flower farmers exposed to pesticides and unexposed individuals as controls. All subjects were interviewed before plasma and urine collection. Manganese and Zinc were measured in theses samples by using dynamic reaction cell inductively coupled mass spectrometry. Cholinesterase activity was analyzed through spectrophotometry by using a modified version of the Ellman method. Seventy-eight percent of subjects reported occupational contact with pesticides, from which 37% reported exposure for over 9 years. Flower farms farmers had increased odds of having headache and irritability, respectively, by factors of 6.2 and 2.4 than the control subjects. While the odds of exposed subjects to have insomnia was smaller than control subjects by a factor of 0.34. Exposure to pesticides had a significant effect regarding the plasmatic plasma and urinary manganese levels and whole blood cholinesterase activity (p < 0.05). High levels of plasma and urinary manganese, as well as cholinesterase inhibition in whole blood, were evident in the flower farmers who participated in the study.

Statewide Evaluation of the California Medical Supervision Program Using Cholinesterase Electronic Laboratory Reporting Data: An Update

The California Medical Supervision Program is designed to protect agricultural workers from overexposure to Toxicity Category I and II organophosphate (OP) and carbamate (CB) pesticides by routinely monitoring their blood cholinesterase (ChE) activity levels. ChE testing is conducted at State-approved laboratories and electronically reported to the Department of Pesticide Regulation (DPR) and the Office of Environmental Health Hazard Assessment (OEHHA) for review. In 2015, OEHHA and DPR evaluated the effectiveness of the Program by analyzing ChE data from pesticide handlers performed between 2011 and 2013, which revealed issues with the data quality that hindered the evaluation process. Several interventions have been implemented since then to improve data quality and the overall function of the Program. A new evaluation was conducted in 2020 to 2021 using data from 2014 to 2019 to determine the effectiveness of the Program, Program compliance, and efficacy of the interventions. The analysis revealed similar data quality issues identified in the last evaluation, however, an improvement in data quality was observed. The number of individuals with ChE depression below the action level threshold have decreased in recent years, corresponding to the implementation of certain interventions, indicating that the effectiveness of the Program has improved. Spatial and temporal analysis showed the proportion of pre-exposure baseline tests inversely correlated with pesticide use data while routine follow-up ChE test results showed a positive correlation, indicating a high degree of Program compliance across the state. Major improvements in the data cleaning and analysis since the last evaluation have also improved the evaluation: pesticide handlers under the Program were able to be identified with more certainty and ChE depressions were able to be calculated with increased accuracy. However, further improvements to the data collection process could enhance future evaluations of the Program.

A new method for determining the cholinesterase activity

Aim. To develop a principally new method, which would allow achieving the necessary accuracy and reproducibility of the analysis results, for determining the activity of the blood cholinesterase; to create safe working conditions when performing the analysis. Results and discussion. The kinetic method proposed for determining the activity of cholinesterase consists in photometric measurement of the rate of the enzymatic hydrolysis of the acetylcholine substrate (by its residue) in the phosphate buffer using p-phenetidine as an indicator. The rate of the enzymatic hydrolysis of acetylcholine was determined by the tangent of the inclination angle of the linear part of the kinetic curve in the А–t coordinates at a wavelength of 358 nm. The linear dependence of the conditional reaction rate (tgα) on the enzyme concentration was observed in the concentration range of 0.12 – 0.36 mg/mL. Metrological characteristics of the method developed were: RSD = 2.0 % (n = 5; P = 0.95), correctness 0.4 %. These values indicate that the method for determining the activity of blood cholinesterase is sensitive, reliable and reproducible. Experimental part. The experiments on determining the rate of the enzymatic hydrolysis were repeated three times with a specific concentration of the enzyme. Using the data obtained the kinetic curves were constructed in the А–t coordinates; on their basis the tangents of the angles of inclination in min-1 were calculated. The calibration graph was constructed using the average values of the tangents of the angles of inclination, which corresponded to a certain concentration of the solution of the working standard sample of the enzyme. The equation of the calibration dependence of tgα-enzyme concentration was calculated by the method of least squares and found to be tgα (min-1) = –0.17с + 9.13 (r = 0.999). Conclusions. As a result of the studies conducted, a new method for determining the activity of the cholinesterase enzyme has been developed. The method is characterized by a high sensitivity, reliability and reproducibility and provides safe working conditions when performing the analysis.

Plasma cholinesterase activity is influenced by interactive effect between omethoate exposure and CYP2E1 polymorphisms

The aim of this study was to explore the association between metabolizing enzyme gene polymorphisms and the decrease in cholinesterase activity induced by omethoate exposure. A total of 180 workers exposed to omethoate over an extended period were recruited along with 115 healthy controls. Cholinesterase activity in whole blood, erythrocyte, and plasma was detected using acetylthiocholine and the dithio-bis-(nitrobenzoic acid) method. Six polymorphic loci of GSTT1(+/-), GSTM1(+/-), GSTP1 rs1695, CYP2E1 rs6413432, CYP2E1 rs3813867, and PON2 rs12026 were detected by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The gene-environment interactions were analyzed using the generalized linear model method. The cholinesterase activity of erythrocyte and plasma in the exposure group was significantly lower than that in the control group (P < 0.001) in general. The plasma cholinesterase activity in the TT + AT genotype in CYP2E1 rs6413432 was lower than that in the AA genotype in the exposure group (P = 0.016). Interaction between the AA genotype in CYP2E1 rs6413432 and omethoate exposure had a significant effect on plasma cholinesterase activity (P = 0.079). The decrease in plasma cholinesterase activity was associated with interaction between the AA genotypes in rs6413432 and omethoate exposure.

Assessment of hepatic oxidative damage, paraoxonase-1 activity, and lipid profile in cattle naturally infected with Ba7besia bigemina.

Naturally occurring Babesia bigemina infection in cattle is associated with changes in the status of oxidative stress, trace elements, sialic acid, and cholinesterase activity in blood. However, to date there is no description of hepatic damage in the infected animals. More importantly, the majority of the above-mentioned causative factors are synthesized or stored in the liver. Therefore, this study was undertaken to evaluate biomarkers of hepatic function, paraoxonase-1 activity, and lipid profile in 13 cattle infected with B. bigemina which did not respond to standard treatment. The animals were necropsied and the histopathology of the liver and DNA damage of hepatocytes were examined. Blood analysis revealed a significant parasitemia burden-dependent increase in the activities of hepatic enzymes and total bilirubin and a decrease in albumin concentrations in the infected cattle compared to the control ones. Paraoxonase-1 activity was remarkably lower in the infected animals than the control. A significant decrease in the blood concentrations of total cholesterol, low density lipoprotein, and high density lipoprotein and a significant increase in the triglyceride concentration were observed in the infected animals. Severe oxidative damages were also recorded in the haptic tissue evidenced by significant alterations in the activities of antioxidant enzymes, suppression of total antioxidant capacity, and oxidation of biomolecules. Congestion of blood vessels, bile duct hyperplasia, and hepatocyte necrosis were the evident histopathologic findings. Our results revealed significant changes in the indices of liver function in the diseased cattle, leading to the conclusion that the parasite can potentially cause liver dysfunction.