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Background. Organophosphate and carbamate pesticides are widely used, and their adverse health effects remain a serious problem. Objectives. This investigation aimed to describe risk factors, erythrocyte acetylcholinesterase (AChE) inhibition, and self-reported symptoms and to derive an association between influence factors and erythrocyte AChE inhibition among farmers in Thailand. Methods. A cross-sectional study was conducted on 71 farmers from August to October 2022. General characteristics and pesticide exposure factors were elicited via a questionnaire-based interview. The erythrocyte AChE inhibition was assessed using the EQM Test-mate Cholinesterase (Model 400) instrument. Data were presented descriptively and analyzed statistically using Chi-square and binary logistic regression. Results. Most farmers were over 50 years old and had an abnormal body mass index (BMI) without alcohol consumption and smoking. Aprons (18.31%) and protective eyewear (12.68%) as personal protective equipment (PPE) were found to be used less often. The level of hemoglobin-adjusted erythrocyte AChE (Q) was considered normal when it was 59.15% and abnormal when it was 40.85%. Self-reported symptoms were confirmed to be associated with lower erythrocyte AChE levels. The Chi-square analysis showed that shortness of breath, irritation, headache, dizziness, sleep fragmentation, and memory problems were significantly associated with erythrocyte AChE (p < 0.05). The bivariate analysis revealed that farmers who consumed alcohol while using pesticides (mixing, loading, and spraying) (OR=35.821, 95% CI=4.591–279.490), who did not wear a mask while using pesticides (OR=11.898, 95% CI=1.061–133.440), and who did not wear boots while using pesticides (OR=0.166, 95% CI=0.031–0.890) had an increased likelihood of having a severe inhibition of erythrocyte AChE. Conclusions. These findings suggest that the promotion of risk prevention practices must be imposed on appropriate pesticide handling and PPE use among farmers.

This study compared mean of erythrocyte acetylcholinesterase (EAChE) and plasma cholinesterase (PChE) activity levels, and levels of psychological distress due to organophosphate (OP) exposure between rainy and dry seasons among farmworkers. This was a longitudinal study conducted in rainy and dry seasons on 30 farmworkers at a village in Brebes Regency, Indonesia. These EAChE and PChE levels were measured from 10μL fingerprick blood samples using the Test-mate ChE field kit. Meanwhile, psychological distress levels were measured by a 10-item questionnaire developed by Kessler et al. (2002). Mean EAChE activity levels in rainy season (29.45 ± 3.68 U/g Hb) were higher than in dry season (26.33 ± 3.69 U/g Hb) (p<0.05). In contrast, mean PChE activity levels in dry season (1.62 ± 0.50 U/mL) were slightly higher than in rainy season (1.61 ± 0.39 U/mL). Most of the farmworkers felt some symptoms of psychological distress both in rainy and dry season measurements. In addition, majority of them were categorized suffering from mental disorders in both measurements. However, the difference of EAChE and PChE activity levels between rainy and dry seasons could be related to the time elapsed since last exposure. A proportion of the research participants suffered from mental disorders in the dry season was higher than that of in the rainy season. The difference of psychological distress levels between both seasons might be related to other external factors like high temperature, high humidity, or economic factors and not to the last OP application. [ABSTRACT FROM AUTHOR]

Self-organized lipid monolayers at the air-water interface (Langmuir films, LF) are commonly used for measuring the catalytic properties of membrane-bound enzymes. This methodology allows to provide a consistent flat topography molecular density, packing defects and thickness. The aim of the present work was to show the methodological advantages of using the horizontal transfer method (Langmuir-Schaefer) with respect to the vertical transfer method (Langmuir-Blodgett) when mounting a device to measure catalytic activity of membrane enzymes. Based on the results obtained we can conclude that it is possible to prepare stable Langmuir-Blodgett (LB) and Langmuir-Schaefer (LS) films from Bovine Erythrocyte Membranes (BEM) preserving the catalytic activity of its native Acetylcholinesterase (BEA). In comparison, the LS films showed V max values more similar to the enzyme present in the vesicles of natural membranes. In addition, it was much easier to produce large amounts of transferred areas with the horizontal transfer methodology. It was possible to decrease the time required to mount an assay with numerous activity points, such as building activity curves as a function of substrate concentration. The present results show that LS BEM provides a proof of concept for the development of biosensors based on transferred purified membrane for the screening of new products acting on an enzyme embedded on its natural milieu. In the case of BEA, the application of these enzymatic sensors could have medical interest, providing drug screening tools for the treatment of Alzheimer's disease. [Display omitted] • Monolayers from bovine erythrocyte membranes (BEM) were transferred to alkylated glass surfaces. • Langmuir-Schaefer (LS) and Langmuir-Blodgett (LB) transference methods were compared. • LS BEM preserved the activity of the acetylcholinesterase (AChE) located in BEM • LS BEM allowed a one-step full kinetic analysis of AChE catalytic activity. • LS BEM stand for a prototype of optical biosensor for monoterpene pesticides. [ABSTRACT FROM AUTHOR]

Background: Organophosphate and carbamate pesticides are widely used, and their adverse health effects remain a serious problem., Objectives: This investigation aimed to describe risk factors, erythrocyte acetylcholinesterase (AChE) inhibition, and self-reported symptoms and to derive an association between influence factors and erythrocyte AChE inhibition among farmers in Thailand., Methods: A cross-sectional study was conducted on 71 farmers from August to October 2022. General characteristics and pesticide exposure factors were elicited via a questionnaire-based interview. The erythrocyte AChE inhibition was assessed using the EQM Test-mate Cholinesterase (Model 400) instrument. Data were presented descriptively and analyzed statistically using Chi-square and binary logistic regression., Results: Most farmers were over 50 years old and had an abnormal body mass index (BMI) without alcohol consumption and smoking. Aprons (18.31%) and protective eyewear (12.68%) as personal protective equipment (PPE) were found to be used less often. The level of hemoglobin-adjusted erythrocyte AChE (Q) was considered normal when it was 59.15% and abnormal when it was 40.85%. Self-reported symptoms were confirmed to be associated with lower erythrocyte AChE levels. The Chi-square analysis showed that shortness of breath, irritation, headache, dizziness, sleep fragmentation, and memory problems were significantly associated with erythrocyte AChE (p < 0.05). The bivariate analysis revealed that farmers who consumed alcohol while using pesticides (mixing, loading, and spraying) (OR=35.821, 95% CI=4.591-279.490), who did not wear a mask while using pesticides (OR=11.898, 95% CI=1.061-133.440), and who did not wear boots while using pesticides (OR=0.166, 95% CI=0.031-0.890) had an increased likelihood of having a severe inhibition of erythrocyte AChE., Conclusions: These findings suggest that the promotion of risk prevention practices must be imposed on appropriate pesticide handling and PPE use among farmers., Competing Interests: The authors declare that there are no conflicts of interest., (Publisher: National Institute of Public Health NIH - National Research Institute.)

Background As pesticide use is increasing and proper handling training is lacking, exposure to pesticides and intoxications are an important public health problems among farmers in developing countries. This study describes pesticide use among farmers and compares symptoms of possible acute intoxication and Erythrocyte Acetylcholinesterase(AChE) levels among vegetable farmers with a control group of blood donors in Nepal. Methods A cross-sectional study was carried out among 90 pesticide-exposed farmers and a control group of 90 blood donors. Participants were randomly selected and data were gathered through questionnaires, observation and blood test. Chi-square test, logistic regression and Student's t-test were used for data analysis to describe pesticide use and compare symptoms and AChE levels between the two groups. This study was approved by Nepal Health Research Council. Results The majority of pesticides used were WHO class II, classified as moderately hazardous. The mean numbers of personal protective equipment used by farmers were 2.22 (95% CI: 1.89; 2.54). Out of five hygienic practices asked, farmers followed 3.63 (95% CI: 3.40; 3.86) hygienic practices on the average. Farmers reported more symptoms of possible pesticide intoxication in the past month than did controls, mean 5.47 (95% CI: 4.70; 6.25) versus 2.02 (95% CI: 1.63; 2.40) (p < 0.05). The mean haemoglobin-adjusted AChE(Q) was significantly lower among farmers compared to controls, 28.92 (95% CI: 28.28; 29.56) U/g versus 30.05 (95% CI: 29.51; 30.60) U/g, (p = 0.01). The risk of a farmer having lower Q level was about 3 times (OR = 2.95; 95% CI: 1.16; 7.51) greater than controls. Conclusion Nepalese farmers exposed to pesticides have significantly more symptoms of possible pesticide intoxication than a control group of healthy individuals. A lower mean haemoglobin- adjusted AChE level was seen among farmers compared to the controls. The use of highly toxic pesticides, inadequate use of personal protective equipment and poor hygienic practices might explain the reason for symptoms of pesticide intoxication and a lower AChE level among farmers. Education and information of farmers should be undertaken to remediate these problems. [ABSTRACT FROM AUTHOR]

BACKGROUND: Serological tests have not been validated in the diagnosis of Hirschsprung's disease. The aim of the present study was to evaluate the role of erythrocyte acetylcholinesterase in the diagnosis of Hirschsprung's disease. METHODS: This study was a prospective study conducted on 30 patients clinically suspected to have Hirschsprung's disease who were admitted in a tertiary care referral center in Srinagar, India. All patients had erythrocyte acetylcholinesterase measured and underwent a full thickness rectal biopsy. RESULTS: In our study, the mean (± standard deviation) age at presentation was 3.51 ± 0.4 years. Most patients were males (76.7%). Rectal biopsy was considered as the gold standard for the diagnosis of Hirschsprung's disease with absent ganglion cells in 22 (73.3%) and absent ganglion cells with nerve hypertrophy in other 4 (13.3%) patients. Preoperative erythrocyte acetylcholinesterase had a diagnostic accuracy of 66.7% and a sensitivity of 84.6% with a specificity of 75%, positive predictive value (PPV) of 95.6% and negative predictive value (NPV) of 42.9%. Mean postoperative acetylcholinesterase levels were 11.5 KU/L, significantly lower than the mean preoperative levels of 17.6 KU/L (p < 0.05). CONCLUSION: Erythrocyte acetylcholinesterase can be used as an initial screening test in clinically suspected cases of Hirschsprung's disease due to its high sensitivity. It confers an additional advantage in that it is comparatively non-invasive and does not require any preparation. [ABSTRACT FROM AUTHOR]

In this study we have examined 532 migrant farm workers engaged mainly in the cultivation of vegetable crops, in both greenhouses and openfarms, and an equal number of controls. Erythrocyte acetylcholinesterase activity (AChE) was measured to determine the degree of toxicity due to exposure to organophosphate and carbamate pesticides in the farm workers employed either as foremen (41.5%) or farmers (58.5%). The mean ages of the farm workers and controls were 35.2±7.4 (mean±SD) years and 34.6±7.1 years. AChE activity of the farm workers and controls was 3.89±0.64 Ul/ml (mean±SD) and 4.15±0.29 Ul/ml. The haemoglobin adjusted erythrocyte cholinesterase activity (HAChE) was 29.96±4.14(mean±SD) for farm workers and 32.10±2.26 for controls. AChE activity was very highly significantly lower for the foremen (3.76±0.69) compared to farmers (3.98±0.59) (Student's t-test=4.13, p=0.0001). HAChE was also very highly significantly lower for foremen (29.24±4.37) compared to farmers (30.46±3.88) (Student's t-test=3.64, p=0.0001). The poorly controlled use of pesticides in the farms appeared to have caused sub-clinical intoxication in the farm workers and indicated the need for training and implementation of hygiene practices. [ABSTRACT FROM PUBLISHER]

Langmuir films prepared from bovine erythrocyte membranes (LF BEM) were studied and transferred to alkylated glasses (Langmuir-Blodgett films, LB BEM) in order to assess the effects of membrane molecular packing on B ovine E rythrocyte A cetylcholinesterase (BEA) catalytic activity. Surface pressure (π) vs Area isotherms showed three 2D-transitions at ~7, ~18 and ~44 mN/m and a collapse pressure at π c = 49 mN/m. The 0–12–0 mN/m compression-decompression cycles resulted reversible while those 0–40–0 mN/m exhibited a significant hysteresis. Taken together, EFM, BAM and AFM images and the stability of the film after 3C-D cycles, we can suggest that over the air-water interface as well as over the silanized glass substrate the surface is mostly covered by a monolayer with a few particles dispersed. Acetylthiocholine hydrolysis was assayed with BEA in bovine erythrocyte membrane suspensions (S BEM) and in LB BEM packed at 10 (LB BEM,10) and 35 mN/m (LB BEM,35), which gave the following kinetic parameters: V max = 3.41 ± 0.15, 0.021 ± 0.002 and 0.030 ± 0.003 nmol.min−1·μg prot−1 and K M = 0.11 ± 0.02, 0.047 ± 0.017 and 0.026 ± 0.017 mM, respectively. Although from S BEM to LB BEM we lost active enzyme, the catalytic efficiency (V max /K M) increased ~750 times. Eugenol and 1,8-cineol inhibited BEA catalytic activity in LB BEM,35. Our results demonstrate the transmission of information between the membrane and the environment within the subphase immediately below the membrane, where anchored proteins are hosted. This was reflected by the membrane packing-induced modulation of BEA catalytic activity. Furthermore, LB BEM provides a proof of concept for the development of biosensors to screen new green pesticides acting through BEA interaction. Bovine erythrocyte acetylcholinesterase (BEA) in Langmuir Blodgett films. Biosensor building and ligand detection. Bovine Erythrocyte Membranes (BEM), obtained from cattle blood, were used as an acetylcholinesterase source to form a Langmuir film at the air-water interface. One-layer Langmuir-Blodgett films (LB BEM) were obtained by transferring the BEM monolayer to alkylated glass substrates at a constant π. The catalytic efficiency exhibited a huge increase with BEA in LB BEM compared with BEA in BEM vesicles. Moreover, the supported BEA was able to sense the presence of monoterpenes in the incubation medium, reproducing the previously described inhibition effect. Unlabelled Image • B ovine E rythrocyte M embrane (BEM) forms stable liquid-expanded Langmuir films (LF BEM). • Langmuir-Blodgett films (LB BEM) are successfully built from LF BEM. • LB BEM retain the activity of B ovine E rythrocyte A cetylcholinesterase (BEA). • BEA catalytic activity serves to probe the molecular packing and dynamics in LB BEM. • LB BEM may stand for a prototype of an optical biosensor for monoterpene pesticides. [ABSTRACT FROM AUTHOR]

Blood lead level (BLL) is insufficiently sensitive for early detection of Lead-induced neurotoxicity (LIN). This study determined the possible role of the combination of BLL, intelligent quotient (IQ) and erythrocyte acetylcholinesterase (AChE) activity in the early detection of LIN in Children. Apparently healthy children (n=309) from eight public primary schools in Ibadan, Nigeria were recruited and classified into: children with Elevated BLL (EBLL) and children with Acceptable BLL (control) based on CDC cut-off for childhood lead exposure. Neurological indices (speech, memory, cranial nerves and cerebellar functions), IQ, BLL and erythrocyte AChE activity were assessed using standard methods, Standard Progressive Matrices, AAS and HPLC respectively. Statistical analysis involved Student's t-test, Pearson's correlation and multivariate regression. p<0.05 was considered significant. There were 169 (54.7%) children with EBLL while there were 140 (45.3%) control children. Both groups exhibited normal speech, memory, cranial nerves and cerebellar functions. However, IQ was lower in EBLL children (85.9±11.6) compared with control (91.5±14.0) while BLL and AChE activity were higher in EBLL children (0.4±0.1 μmol/l; 117.5±25.5 μkat/l) compared with control (0.2±0.0 μmol/l; 59.4±10.2 μkat/l). BLL showed inverse correlation with IQ (r=-0.134, p =0.019) but positive correlation with AChE (r=0.978, p ≤0.001). 16.2% of the observed variation in BLL could be accounted for by AChE using the equation; [BLL=-0.007+0.003 AChE] p <0.05. Elevated blood lead level is prevalent among the school children and appears to have adverse effect on their IQ. Erythrocyte AChE could be a promising marker for early recognition of significant environmental lead exposure and lead-induced neurotoxicity in children., (Copyright © 2019 SETOX & Institute of Experimental Pharmacology and Toxicology, SASc.)

Acetylcholinesterase expression is modulated in various types of tumor, which suggests it is associated with tumor development; however, the mechanism of acetylcholinesterase gene regulation in tumors remains unclear. Here, we report that acetylcholinesterase is aberrantly expressed in non-small cell lung cancer and is an evolutionarily conserved functional target of miR-212. Acetylcholinesterase expression was negatively regulated by miR-212 in vitro and was inversely correlated with miR-212 expression in vivo. In addition, acetylcholinesterase levels were increased, and miR-212 levels decreased, in non-small cell lung cancer cells during cisplatin-induced apoptosis. We further determined that acetylcholinesterase acted as a pro-apoptotic gene in non-small cell lung cells; and attenuated the growth of xenografts in nude mice when upregulated. In contrast, elevated miR-212 levels preserved the protective effect of acetylcholinesterase silencing by RNA interference against cisplatin-induced apoptosis, whereas restoration of miR-212-resistant synaptic acetylcholinesterase expression inhibited the miR-212 anti-apoptotic function. The results demonstrated that miR-212 exerted an anti-apoptotic effect through direct repression of synaptic acetylcholinesterase expression in non-small cell lung cancer cells. Taken together, our study revealed that synaptic acetylcholinesterase may be a tumor suppressor and is modulated by miR-212 in non-small cell lung cancer., (Copyright © 2013 Elsevier Ltd. All rights reserved.)