Red Blood Cell Acetylcholinesterase Activity Research Articles

Human red blood cell acetylcholinesterase activity: a revisit after fifteen years

Human red blood cell acetylcholinesterase (RBC-AChE) activity is valuable for detecting potential exposure to cholinesterase inhibiting substances (CIS). A reliable population-based RBC-AChE activity reference range is critical for early and massive clinical and occupational toxicology screening. Previous published studies were often limited to small numbers of subjects, various testing methods, and crude statistical data analyses. We tested 4818 adult subjects with a well-established 17-minute modified Michel method over a 2-year period. We conducted a retrospective data analysis and systematically investigated on the influences to testing values from gender, age, age group, and their combinations and interactions. No significant difference was observed in the testing values between males (mean, medium, interquartile range = 0.76, 0.76, 0.71–0.80 ΔpH/h, respectively) and females (mean, medium, interquartile range = 0.76, 0.76, 0.71–0.81 ΔpH/hour, respectively), when gender was the only factor considered (p = 0.7238). However, with age progression, male testing values exhibited a consistent upward trend, while females did not show any clear patterns. Linear regression analysis of the data revealed that gender, age, and age group more or less affected testing values either as independent variables or with their combinations and interactions. However, more potential factors need to be included to achieve better testing value predictions. We recommend the toxicological testing community to adopt a new set of age group specific RBC-AChE activity reference ranges for males (0.68–0.80, 0.69–0.81, 0.70–0.83, 0.71–0.84, and 0.73–0.87 ΔpH/h for 18–29, 30–39, 40–49, 50–59, and ≥60 years old, respectively) while keeping the current reference range (0.63–0.89 ΔpH/hour) for females.

Literature Review: Impact of Organophosphate Pesticide Exposure on Cholinesterase Enzyme Activity and Associated Risk Factors for Poisoning, 2017-2020

Introduction: Organophosphate pesticides, which are used to control pests of crops, affect the nervous system by inhibiting the activity of cholinesterase enzymes in the body. This can be achieved by inhaling, eating, or applying it to the skin. This study research aims to determine the level of pesticide exposure that can inhibit the activity of the Cholinesterase enzyme in the blood. This study employed a systematic literature review with library sources used through Google Scholar and Science Direct, resulting in 16 research articles discussing cholinesterase enzyme activity due to exposure to organophosphates discussed in 2017-2020. Discussion: The results of a previous study found that exposure to organophosphates significantly reduced cholinesterase enzyme activity by 50-80%. Testing for cholinesterase as a biomarker of exposure to Organophospate (OP) through acetylcholinesterase activity in red blood cells (AChE). This study explored the relationship between gender, age, knowledge of farmers, personal protective equipment, farmers’ smoking behavior, and duration of spraying. Conclusion: Poisoning alters the activity of cholinesterase enzymes in the blood of farmers, resulting in acute and chronic health problems. Several factors have been found to correlate with organophosphate poisoning, including age, level of knowledge among farmers, use of personal protective equipment, smoking behavior, and duration of spraying activities.

An exploratory study; the gap between real reference interval and currently used reference interval of RBC AChE activities in South Korea

ABSTRACT The current reference interval (RI) FOR red blood cell acetylcholinesterase (RBC AChE) activity in South Korea was established with data obtained from populations outside the country. The aim of this study was to assess the transferability of current RI of RBC AChE activity for organophosphate (OP) poisoning and determine the biological characteristics, real RI, and interindividual variation in RBC AChE activity in South Korea. Data were retrospectively collected for RBC AChE activity as measured by the modified Ellman’s method for 782 patients who presented to our hospital. The clinical course did not differ significantly with the degree of deviation of RBC AChE activity from the currently used RI in 195 patients exposed to OP. RBC AChE activity was associated with gender and smoking status but not age or body mass index (BMI); however, a regression model incorporating age, gender, smoking status and BMI explained only a small portion of the variance in RBC AChE activity in South Korea. The RI of RBC AChE activity was 9,403–16,825 U/L, with 13.9% interindividual variation. The range of RBC AChE activity in South Korea is wider than RI currently used in clinical practice and exhibited a high degree of interindividual variation. In the absence of collecting pre-exposure values, it is recommended to conduct serial measurements, rather than one-point measurements, of RBC AChE activity as evidenced by the RI in OP poisoning.

Pro: Oximes should be used routinely in organophosphate poisoning.

In poisoning with organophosphorus compounds (OP), patients can only profit from the regeneration of acetylcholinesterase, when the poison load has dropped below a toxic level. Every measure that allows an increase of synaptic acetylcholinesterase (AChE) activity at the earliest is essential for timely termination of the cholinergic crisis. Only drug-induced reactivation allows fast restoration of the inhibited AChE. Obidoxime and pralidoxime have proved to be able to reactivate inhibited cholinesterase thereby saving life of poisoned animals. A plasma level of obidoxime or pralidoxime allowing reactivation in humans poisoned by OP can be adjusted. There is no doubt that obidoxime and pralidoxime are able to reactivate OP-inhibited AChE activity in poisoned patients, thereby increasing AChE activity and contributing substantially to terminate cholinergic crisis. Hence, a benefit may be expected when substantial reactivation is achieved. A test system allowing determination of red blood cell AChE activity, reactivatability, inhibitory equivalents and butyrylcholinesterase activity is available for relatively low cost. If any reactivation is possible while inhibiting equivalents are present, oxime therapy should be maintained. In particular, when balancing the benefit risk assessment, obidoxime or palidoxime should be given as soon as possible and as long as a substantial reactivation may be expected.

A low GLP-1 response among patients treated for acute organophosphate and carbamate poisoning: a comparative cross-sectional study from an agrarian region of Sri Lanka

Higher incidence of diabetes along with increased use of pesticides is seen in Southeast Asia. Recent hypothesis postulated a link between acetylcholinesterase inhibitor insecticides and type 2 diabetes through the GLP-1 pathway. This study compares the GLP-1 response between groups with low and high red blood cell acetylcholinesterase (RBC-AChE) activity. A comparative cross-sectional study was conducted amongst patients who were within 3months after an acute organophosphate or carbamate poisoning (acute group) and amongst vegetable farmers with low (chronic group) and high (control group) RBC-AChE activity. Acute (366mU/μM Hb) and chronic (361mU/μM Hb) groups had significantly lower RBC-AChE activity in comparison to the control (471mU/μM Hb) group (P < 0.0001). Only the acute group, which has had atropine therapy, showed a significantly lower 120min value in comparison to the control group (P = 0.0028). Also, the acute group had significantly low late (P = 0.0287) and total (P = 0.0358) responses of GLP-1 in comparison to the control group. The findings of the study allude towards attenuation of GLP-1 response amongst patients after acute organophosphate and carbamate poisoning. The possibility of an atropine-mediated attenuation of GLP-1 response was discussed.

Red blood cell acetylcholinesterase activity among healthy dwellers of an agrarian region in Sri Lanka: a descriptive cross-sectional study

BackgroundAssessment of acetylcholinesterase-inhibitor insecticide (AChEII) toxicity depends on the measurement of red blood cell acetylcholinesterase (RBC-AChE) activity. Its interpretation requires baseline values which is lacking in scientific literature. We aim to find the measures of central tendency and variation for RBC-AChE activity among dwellers of Anuradhapura, where the use and abuse of AChEIIs were rampant for the last few decades.MethodsA descriptive cross-sectional study with a community-based sampling for 100 healthy non-farmers (male:female = 1:1) was done using pre-determined selection criteria. Duplicate measurements of RBC-AChE activity were performed according to the modified Ellman procedure. Pearson’s correlation and regression analysis were sort for RBC-AChE activity against its possible determinants.ResultsRBC-AChE activity had a mean of 449.8 (SD 74.2) mU/μM Hb with a statistical power of 0.847. It was similar to values of “healthy controls” from previous Sri Lankan toxicological studies but was low against international reference value [586.1 (SD 65.1) mU/μM Hb]. None of the possible determinants showed a significant strength of relationship with RBC-AChE activity.ConclusionThe baseline RBC-AChE activity among people of Anuradhapura is low in comparison with international reference values. This arises a need to find a causative mechanism.

Protective effects of chrysin on sub-acute diazinon-induced biochemical, hematological, histopathological alterations, and genotoxicity indices in male BALB/c mice

Chrysin (CH) is a natural flavone which possesses antioxidant, anti-cancer, and anti-inflammatory properties. The aim of the present study was to investigate the effects of CH on biochemical parameters, histopathological changes, and genotoxicity and hematological indices in diazinon (DZN)-induced toxicity in BALB/c mice. We induced sub-acute toxicity in mice using DZN (20 mg/kg/day) and treated them with CH at the 12.5, 25, and 50 mg/kg/day five times/week in 28 days. In our study, DZN increased lipid profile and liver function tests (LFTs) and creatinine (Cr) but decreased the red blood cell acetylcholinesterase (RBC-AChE) activity and glucose level. Also, CH when co-treated with DZN changed the LFTs, lipid profile, creatine phosphokinase (CPK), lactate dehydrogenase (LDH) and bilirubin total (Bili-T). Moreover, a significant decrease in RBCs, hemoglobin (Hgb), hematocrit (HCT) level, and platelet counts were seen in DZN group but WBCs, lymphocytes, and neutrophils count increased. CH 25 and 50 mg/kg significantly improved alterations of WBCs, RBCs, Hgb, HCT, lymphocytes, neutrophils, and reticulocytes count when co-treated with DZN. Moreover, the co-administration of CH plus DZN recovered histopathological alterations in liver and kidney, as well as, improved the absolute and relative weight of kidney and liver. DZN induced the formation of bone marrow micronuclei (MN) but CH 50 mg/kg decreased the MN formation when co-treated with DZN. These results suggest that CH not only restores renal and hepatic markers, and histopathological alterations but also improves hematological and genotoxicity indices induced by DZN in mice.

Effects of acute exposure to chlorpyrifos on cholinergic and non-cholinergic targets in normal and high-fat fed male C57BL/6J mice

The prevalence of obesity is increasing at an alarming rate in the United States with 36.5% of adults being classified as obese. Compared to normal individuals, obese individuals have noted pathophysiological alterations which may alter the toxicokinetics of xenobiotics and therefore alter their toxicities. However, the effects of obesity on the toxicity of many widely utilized pesticides has not been established. Therefore, the present study was designed to determine if the obese phenotype altered the toxicity of the most widely used organophosphate (OP) insecticide, chlorpyrifos (CPS). Male C57BL/6J mice were fed normal or high-fat diet for 4weeks and administered a single dose of vehicle or CPS (2.0mg/kg; oral gavage) to assess cholinergic (acetylcholinesterase activities) and non-cholinergic (carboxylesterase and endocannabinoid hydrolysis) endpoints. Exposure to CPS significantly decreased red blood cell acetylcholinesterase (AChE) activity, but not brain AChE activity, in both diet groups. Further, CPS exposure decreased hepatic carboxylesterase activity and hepatic hydrolysis of a major endocannabinoid, anandamide, in a diet-dependent manner with high-fat diet fed animals being more sensitive to CPS-mediated inhibition. These in vivo studies were corroborated by in vitro studies using rat primary hepatocytes, which demonstrated that fatty acid amide hydrolase and CES activities were more sensitive to CPS-mediated inhibition than 2-arachidonoylglycerol hydrolase activity. These data demonstrate hepatic CES and FAAH activities in high-fat diet fed mice were more potently inhibited than those in normal diet fed mice following CPS exposure, which suggests that the obese phenotype may exacerbate some of the non-cholinergic effects of CPS exposure.

Fatal poisoning by terbufos following occupational exposure

Context: Terbufos (TBF) is a class Ia (extremely hazardous) organophosphate pesticide (OP) and its distribution in industrialized countries has been severely restricted. Thus, acute occupational poisoning is rather uncommon. However, it still occurs in rural areas of some developing countries, where the sale of TBF is not controlled and its use is thus not properly regulated. We report a case of a 43-year-old female farmer who died after applying TBF granules.Case: The patient died within 3 h after applying 20 bags of 5% TBF granules (900 g per bag). Investigation showed that her personal protective equipment (PPE) did not provide effective protection against dermal and inhalational exposure. Postmortem analysis revealed extremely low red blood cell acetylcholinesterase activity. Toxicological analysis of TBF showed 1.45 × 10−2 μg/ml in the heart blood and 0.17 μg/g in the liver.Discussions: This patient died as a result of toxicity from dermal and inhalational exposure to TBF. Over-application, improper equipment, inadequate and defective PPE, and lack of hygienic precautions were all contributing factors.Conclusions: TBF is a highly toxic OP. Inadequate regulatory control, improper environmental application, and ineffective PPE resulted in a fatal human exposure.

Variable response of cholinesterase activities following human exposure to different types of organophosphates.

We investigated the red blood cell (RBC) acetylcholinesterase (AChE) activities and butyrylcholinesterase (BChE) activities at presentation to the emergency department (ED) and at 24 h after presentation following poisoning by dichlorvos, fenitrothion, or ethyl p-nitrophenol thio-benzene phosphonate (EPN). Although the patients from different groups had similar characteristics at presentation such as time interval from ingestion to presentation to the ED and the amount of organophosphate ingested, the dichlorvos group had significantly lower BChE levels than the fenitrothion group and lower RBC cholinesterase activity than the EPN group. Patients poisoned with EPN or dichlorvos had significantly higher inhibition of BChE activities from baseline than RBC AChE activities at presentation. Twenty four hours after administration of pralidoxime, RBC AChE activities had increased in patients in the dichlorvos and EPN groups, while RBC AChE activities had slightly decreased in the fenitrothion group. BChE activities increased significantly in the dichlorvos group but decreased in the EPN group. The recovery patterns of RBC AChE and BChE activities did not match in any particular individual. This study showed that the patterns of inhibition and recovery of the activities of two cholinesterases after treatment are highly variable according to the organophosphate and in different individuals.

Utility of red blood cell acetylcholinesterase measurement in mechanically ventilated subjects after organophosphate poisoning.

Many patients with organophosphate poisoning require mechanical ventilation. Muscle acetylcholinesterase (AChE) activity determines the impairment of muscle force generation, and red blood cell (RBC) AChE has been regarded as a surrogate for muscle AChE in organophosphate poisoning. Therefore, this study was conducted to investigate whether RBC AChE at presentation can predict the duration of mechanical ventilatory support and whether RBC AChE at weaning can predict weaning trial outcomes in patients on mechanical ventilation for organophosphate poisoning. This retrospective observational case series identified 74 patients with a history of mechanical ventilation secondary to organophosphate poisoning and whose RBC AChE levels were available at presentation to the emergency department, at 24 h of presentation, or at weaning. Data were collected for plasma cholinesterase assay results, weaning outcome, duration of mechanical ventilation, and details of patient management (including ICU stay and amount of atropine and pralidoxime administered). RBC AChE activity levels at presentation and at 24 h of presentation had a negative correlation with duration of mechanical ventilation in subjects who ingested dimethyl organophosphate, but this correlation was not observed for those who had ingested diethyl or unclassified organophosphate. The optimal cutoff value of RBC AChE activity at presentation for predicting mechanical ventilation for < 7 d was 1,330 U/L in subjects intoxicated with dimethyl organophosphate. However, there was no difference in RBC AChE activity at the time of weaning trial between successful and failed weaning events, regardless of the chemical formulation of organophosphate. We conclude that RBC AChE activity within 24 h of presentation can help predict the duration of mechanical ventilation for dimethyl organophosphate intoxication; however, RBC AChE activity at the time of weaning trial may not be a suitable parameter for predicting a patient's ability to be weaned from mechanical ventilation.

Mixed-effect circadian rhythm model for human erythrocyte acetylcholinesterase activity—application to the proof of concept of cholinesterase inhibition by acorn extract in healthy subjects with galantamine as positive control

The aim of this study was to develop a non-linear mixed effect circadian rhythm model of acetylcholinesterase (AChE) activity variation and to evaluate the inhibitory effect of acorn extract (2 g) and galantamine (16 mg), used as positive control, on human AChE in red blood cells (RBC). This was an open-label, randomized, three-way crossover study involving 12 healthy subjects who received one of the treatments in each study period: no treatment, acorn extract, and galantamine. RBC AChE activity was measured in peripheral blood samples collected at 0 (pre-dose), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16 and 24 h post-dose administration. Non-linear mixed effect modeling was performed using NONMEM (ver. 7.0). The circadian variation of AChE activity was best described using two mixed effect cosine functions, with periods of 24 and 12 h, respectively. When the inhibitory effect terms were added, the model was significantly improved for both acorn extract and galantamine. In terms of the effect, a 2-g single dose of acorn extract showed AChE inhibition (about 5%) similar to that of a 16-mg single dose of galantamine, in the first 24 h after administration. Based on the very pronounced inter- and intra-day variation in AChE activity in RBC, we conclude that the model-based approach is essential for the proof of concept and quantitation of AChE inhibition in human subjects.

Cholinergic system of rats treated with vincristine sulphate and nandrolone decanoate

This study aimed to detect brain and red blood cell acetylcholinesterase activity (AChE and RBC-AChE, respectively) of rats treated with vincristine sulphate and different doses of nandrolone decanoate. Thirty rats were divided into six groups (n = 5). The treatments were applied once a week for 2 weeks. Sample collection was performed in the third week. The groups were divided in: G1, physiologic solution (PS) (first and second week); G2, vincristine sulphate (4 mg/m2) in the first week and PS in the second week; G3, PS in the first week and nandrolone decanoate (1.8 mg/kg−1) in the second week; G4, PS in the first week and nandrolone decanoate (10 mg/kg−1) in the second week; G5, vincristine sulphate (4 mg/m2) in the first week and nandrolone decanoate (1.8 mg/kg−1) in the second week; and G6, vincristine sulphate (4 mg/m2) in the first week and nandrolone decanoate (10 mg/kg−1) in the second week. The isolated use of nandrolone decanoate and its use in association with vincristine sulphate altered brain AChE and RBC-AChE activity. These results suggest that there is interference in cholinergic neurotransmission, which could cause an alteration of its neurotransmitter, as well as a low or high stimulation of post-synaptic receptors. The serum RBC-AChE activity results presented in this study are similar to those exhibited by brain tissue.

Monitoring of neuromuscular transmission in organophosphate pesticide-poisoned patients

Thirty-four adult patients with severe organophosphorus compounds (OP) poisoning requiring artificial ventilation were enrolled in a clinical study and received atropine and obidoxime (250mg i.v., followed by 750mg/24h) as antidotal treatment. Here, we re-analyzed the cholinesterase status (red blood cell acetylcholinesterase (RBC-AChE) activity, reactivatability of RBC-AChE, and plasma butyrylcholinesterase (Pl-BChE) activity) in relation to the neuromuscular transmission (NMT) data. When RBC-AChE activity ranged between 100% and 30% NMT was unimpaired after tetanic stimulation with frequencies up to 50Hz. A further decrease in RBC-AChE activity was accompanied by a marked disturbance of NMT, being strongly impaired at AChE activities <5% of normal. Higher stimulation frequencies (>30Hz) facilitated the discrimination of the types of impairment. The neuromuscular transmission was the best quantified by using the ratio of the ninth to the first amplitude, while the standard method was less discriminative. At RBC-AChE levels higher than 40% of normal weaning from the ventilator may be considered. Completely aged RBC-AChE as indicated by loss of reactivatability loses its guidance function. Then, steadily increasing Pl-BChE activity suggests lack of circulating poison. One-week later, neuromuscular transmission may be largely normal and patients could be weaned from the respirator if other complications are not withstanding.

Retrospective population pharmacokinetic/pharmacodynamic analysis of pyridostigmine, a cholinesterase inhibitor, in Chinese males

We have characterised the population pharmacokinetics-pharmacodynamics of pyridostigmine given as pyridostigmine bromide. Over three days 50 healthy Chinese male subjects each received seven doses of 30 mg pyridostigmine bromide orally (3 x 10 mg every 8 h). Plasma concentrations of pyridostigmine and red blood cell acetylcholinesterase (AChE) activity were determined at various times within the eight hours after the first and the seventh doses. The resulting pharmacokinetic data were fitted to a single compartment open model with first-order absorption and elimination. The pharmacodynamics were modelled using an inhibitory E(max) model. The potential influence of demographic and biological covariates on the model parameters was investigated. Nonlinear mixed effects modelling was performed using NONMEM. The apparent clearance and volume of distribution as well as absorption rate constant of plasma pyridostigmine were estimated to be 136 l/h, 130 l and 0.68 1/h, respectively. The maximum red blood cell AChE activity decrease (E(max)) and plasma pyridostigmine concentration producing 50% of this reduction (EC50) were estimated to be 9.32 AChE units per gram haemoglobin and 51.9 ng/ml, respectively. None of the tested covariates were found to be correlated with any of the model parameters. Dosing simulations suggested that 30 mg repeated every six hours might be needed to achieve steady-state trough percentage inhibition above the recommended 10% in healthy Chinese males. The pharmacokinetics and the effects of pyridostigmine on red blood cell AChE activity were described using a mixed effects model. For Chinese males, the dosing interval may have been shorter than that recommended for the Caucasian population. Additional studies are needed to confirm these findings.

Retrospective population pharmacokinetic/pharmacodynamic analysis of pyridostigmine, a cholinesterase inhibitor, in Chinese males

AbstractObjectivesWe have characterised the population pharmacokinetics-pharmacodynamics of pyridostigmine given as pyridostigmine bromide.MethodsOver three days 50 healthy Chinese male subjects each received seven doses of 30 mg pyridostigmine bromide orally (3 times 10 mg every 8 h). Plasma concentrations of pyridostigmine and red blood cell acetylcholinesterase (AChE) activity were determined at various times within the eight hours after the first and the seventh doses. The resulting pharmacokinetic data were fitted to a single compartment open model with first-order absorption and elimination. The pharmacodynamics were modelled using an inhibitory Emax model. The potential influence of demographic and biological covariates on the model parameters was investigated. Nonlinear mixed effects modelling was performed using NONMEM.Key findingsThe apparent clearance and volume of distribution as well as absorption rate constant of plasma pyridostigmine were estimated to be 136 1/h, 130 1 and 0.68 1/h, respectively. The maximum red blood cell AChE activity decrease (Emax) and plasma pyridostigmine concentration producing 50% of this reduction (EC50) were estimated to be 9.32 AChE units per gram haemoglobin and 51.9 ng/ml, respectively. None of the tested covariates were found to be correlated with any of the model parameters. Dosing simulations suggested that 30 mg repeated every six hours might be needed to achieve steady-state trough percentage inhibition above the recommended 10% in healthy Chinese males.ConclusionsThe pharmacokinetics and the effects of pyridostigmine on red blood cell AChE activity were described using a mixed effects model. For Chinese males, the dosing interval may have been shorter than that recommended for the Caucasian population. Additional studies are needed to confirm these findings.

Normal range of human red blood cell acetylcholinesterase activity

The normal range of human erythrocyte acetylcholinesterase (RBC-AChE) activity is important when monitoring exposure to pesticides and chemical warfare agents. A modification of Michel’s method measured RBC-AChE activities from 991 individuals (818 males and 173 females) presumably unexposed to nerve agents. Median age was 42 (range, 18–76) years. RBC-AChE (mean ± SD) was 0.74 ± 0.06 delta pH units/hour. Multivariate linear regression showed an association with age (slope +0.0008 delta pH units/hour for each year; P < 0.001) unlikely to be clinically significant. The findings represent the largest study of human RBC-AChE to date providing measures of central tendency and variation.

Blood Cholinesterases from Washington State Orchard Workers

Court-ordered monitoring of blood cholinesterases (ChEs) from orchard workers in Washington State is underway. In 2008, the mean red blood cell acetylcholinesterase (AChE, EC 3.1.1.7) activity was 9.65 ± 1.11 μmoles/min/ml (n = 1,793) and the mean serum (BChE, 3.1.1.6) activity was 5.19 ± 0.90 μmoles/min/ml (n = 1,811). Determinations were made using the Ellman assay and automated equipment of Pathology Associates Medical Laboratories (PAML), Spokane, Washington.

Nippostrongylus brasiliensis: Infection decreases plasma butyrylcholinesterase activity in rats

Plasma butyrylcholinesterase (BChE) hydrolyzes ester-containing compounds such as succinylcholine, as well as acting as a scavenger against neurotoxic organophosphates (OPs). We previously found that Nippostrongylus brasiliensis infection makes rats more susceptible to OP toxicity by decreasing serum paraoxonase-1 (PON1) activity. In the present study, we examined the effects of N. brasiliensis infection on acetylcholinesterase (AChE) activity in plasma, red blood cells (RBCs), brain and diaphragm, as well as serum PON1 activity, in rats at day 7 after infection. N. brasiliensis infection significantly decreased plasma BChE and PON1 activities without significantly altering AChE activity in RBCs, brain and diaphragm. These results provide further insight into the unusual deleterious effects of intestinal nematode infections on body homeostasis.

Acute cholinergic syndrome following ingestion of contaminated herbal extract

Herbal preparations are becoming more and more popular and increasingly used in the USA. Herbs are from natural plants and therefore often considered to be harmless compared with western medicines....