A transparent, lateral-flow test strip coupled with a smartphone-based ambient light sensor was first proposed for detecting enzymatic inhibition and phosphorylation. The principle of the platform is based on the simultaneous measurement of the total amount of the enzyme and enzyme activity to biomonitor exposure to organophosphorus (OP) pesticides. In this study, butyrylcholinesterase (BChE) was adopted as the model enzyme and ethyl paraoxon was chosen as an analyte representing OP pesticides. The total amount of BChE was quantified by a sensitive colorimetric signal originating from a sandwich immunochromatographic assay utilizing PtPd nanoparticles as a colorimetric probe, which exhibited excellent catalytic activity for phenols. In the sandwich immunoassay, only one antibody against BChE was simultaneously utilized as the recognition antibody and the labeling antibody due to the tetrameric structure of native BChE. The BChE activity was estimated by another colorimetric signal using the Ellman assay. ...

A Nanozyme- and Ambient Light-Based Smartphone Platform for Simultaneous Detection of Dual Biomarkers from Exposure to Organophosphorus Pesticides

ObjectiveTo characterize the frequency of aspiration pneumonitis in an unselected population of overdose patients and, further, to identify factors that predispose to aspiration pneumonitis and the outcomes of patients with aspiration pneumonitis compared with those without. DesignRetrospective cohort study. SettingToxicology unit of a tertiary referral hospital. PatientsAll poisoning admissions. Measurements and Main ResultsA total of 71 of 4,562 poisoning admissions to the Hunter Area Toxicology Service between January 1997 and October 2002 had definite aspiration pneumonitis (1.6%; 95% confidence interval, 1.2–2.0). Older age, Glasgow Coma Score of <15, spontaneous emesis, seizures, delayed presentation to hospital, and ingestion of tricyclic antidepressants were associated with an increased risk of aspiration pneumonitis. Paracetamol poisoning and female sex were associated with a decreased risk of aspiration pneumonitis with univariate analysis. Ingestion of alcohol, benzodiazepines, antipsychotics, and administration of activated charcoal were not associated with aspiration pneumonitis. A logistic regression model for predicting aspiration pneumonitis contained seven predictors: age, sex, Glasgow Coma Score of <15 (odds ratio, 3.14; 95% confidence interval, 1.87–5.27), emesis (odds ratio, 4.17; 95% confidence interval, 2.44–7.13), seizure, tricyclic antidepressant ingestion, and time from ingestion to presentation (delay of >24 hrs [odds ratio, 4.42; 95% confidence interval, 2.42–8.10]). The mortality for patients with aspiration pneumonitis was 8.5% compared with 0.4% for those without (odds ratio, 23; 95% confidence interval, 9–60; p < .0001), and they had a significantly higher intensive care unit admission rate. The median length of stay of patients with aspiration pneumonitis was 126 hrs (interquartile range, 62–210 hrs) compared with 14.7 hrs (interquartile range, 7–23 hrs) in patients without (p < .0001). ConclusionsOur study has shown a number of risk factors in overdose patients that are associated with aspiration pneumonitis that may allow the early identification of these patients for appropriate observation and management. Patients with aspiration pneumonitis have a significantly increased mortality and length of stay in the hospital.

Aspiration pneumonitis in an overdose population: frequency, predictors, and outcomes | NOVA. The University of Newcastle's Digital Repository

Organophosphorus insecticide self-poisoning is a major global health problem, killing over 100,000 people annually It is a complex multi-organ condition, involving the inhibition of cholinesterases, and perhaps other enzymes, and the effects of large doses of ingested solvents Variability between organophosphorus insecticides-in lipophilicity, speed of activation, speed and potency of acetylcholinesterase inhibition, and in the chemical groups attached to the phosphorus-results in variable speed of poisoning onset, severity, clinical toxidrome, and case fatality Current treatment is modestly effective, aiming only to reactivate acetylcholinesterase and counter the effects of excess acetylcholine at muscarinic receptors Rapid titration of atropine during resuscitation is lifesaving and can be performed in the absence of oxygen The role of oximes in therapy remains unclear Novel antidotes have been tested in small trials, but the great variability in poisoning makes interpretation of such trials difficult More effort is required to test treatments in adequately powered studies

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Novel clinical toxicology and pharmacology of organophosphorus insecticide self-poisoning.

Summary Organophosphorus (OP) nerve agent poisoning made the headlines in 2018 with the nerve agent ‘Novichok' poisonings in Salisbury, England. This event highlighted a gap in the knowledge of most clinicians in the UK. In response, this special article aims to enlighten and signpost anaesthetists and intensivists towards the general management of OP nerve agent poisoned patients. Drawing on a broad range of sources, we will discuss what OP nerve agents are, how they work, and how to recognise and treat OP nerve agent poisoning. OP nerve agents primarily act by inhibiting the enzyme acetylcholinesterase, causing an acute cholinergic crisis; death usually occurs through respiratory failure. The antimuscarinic agent atropine, oximes (to reactivate acetylcholinesterase), neuroprotective drugs, and critical care remain the mainstays of treatment. The risk to medical staff from OP poisoned patients appears low, especially if there is a thorough decontamination of the poisoned patient and staff wear appropriate personal protective equipment. The events in Salisbury in the past year were shocking, and the staff at Salisbury District General Hospital performed admirably in treating those affected by Novichok nerve agent poisoning. We eagerly anticipate their future clinical publications so that the medical community might learn from their valuable experiences.

Organophosphorus nerve agent poisoning: managing the poisoned patient

Context. A position paper on the use of whole bowel irrigation (WBI) was first published in 1997 by the American Academy of Clinical Toxicology (AACT) and the European Association of Poisons Centre...

http://www.emergpa.net/wp/wp-content/uploads/Position-paper-update-Whole-bowel-irrigation-for-gastrointestinal-decontamination-of-overdose-patients.pdf

Position paper update: whole bowel irrigation for gastrointestinal decontamination of overdose patients.

Organophosphorus (OP) compound poisoning is a major global public health problem. Acute OP insecticide self-poisoning kills over 200,000 people every year, the majority from self-harm in rural Asia. Highly toxic OP nerve agents (e.g., sarin) are a significant current terrorist threat, as shown by attacks in Damascus during 2013. These anticholinesterase compounds are classically considered to cause an acute cholinergic syndrome with decreased consciousness, respiratory failure, and, in the case of insecticides, a delayed intermediate syndrome that requires prolonged ventilation. Acute respiratory failure, by central and peripheral mechanisms, is the primary cause of death in most cases. However, preclinical and clinical research over the last two decades has indicated a more complex picture of respiratory complications after OP insecticide poisoning, including onset of delayed neuromuscular junction dysfunction during the cholinergic syndrome, aspiration causing pneumonia and acute respiratory distress syndrome, and the involvement of solvents in OP toxicity. The treatment of OP poisoning has not changed over the last 50 years. However, a better understanding of the multiple respiratory complications of OP poisoning offers additional therapeutic opportunities.

Alfred M. Sciuto

Papers

Respiratory complications of organophosphorus nerve agent and insecticide poisoning. Implications for respiratory and critical care.