Sarin poisoning on Tokyo subway

Phosphonylated tyrosine and cysteine disulfide adducts both generated from immunoglobulin G and human serum albumin indicate exposure to the nerve agent VX in vitro

Pronase-catalyzed proteolysis is shown to produce single amino acid adducts of tyrosine (Tyr) and cysteine (Cys) obtained from both human serum albumin (HSA) and immunoglobulin G (IgG) after in vitro exposure of plasma to the nerve agent VX. Total plasma as well as isolated HSA and IgG yielded the Tyr residue phosphonylated with the ethyl methylphosphonic acid moiety, Tyr(-EMP). Furthermore, a Cys residue adducted with the diisopropylaminoethane thiol leaving group of the agent bound via a disulfide bridge, Cys(-DPAET), was also obtained from both proteins. Even though Tyr(-EMP) represents an internationally well-accepted biomarker of a VX-like agent its origin from plasma IgG has never been shown before. In addition, this is the first time that Cys(-DPAET) is presented as a biomarker of VX exposure clearly identifying the chemical nature of the V-type nerve agent's leaving group. Both biomarkers were detected after selective affinity-based solid-phase extraction (SPE) from plasma that yielded highly purified HSA and IgG as documented by sodium dodecyl polyamide gel electrophoresis (SDS-PAGE). Both biomarkers were found in the corresponding protein bands of HSA and IgG each after in-gel proteolysis with pronase. A micro liquid chromatography-electrospray ionization high-resolution tandem-mass spectrometry method (LC-ESI HR-MS/MS) was developed for the simultaneous detection of Tyr(-EMP) and Cys(-DPAET). The time for proteolysis was optimized for maximum biomarker yield. The method showed excellent selectivity and sensitivity, and the adducted proteins and biomarkers were found to be highly stable during storage. Accordingly, the presented method sheds more light on the molecular toxicology of VX and broadens the spectrum of methods suited for biomedical verification.

Spatiotemporal perturbations of the plasminogen activation system in a rat model of acute organophosphate intoxication

Neuroinflammation is widely posited to be a key pathogenic mechanism linking acute organophosphate (OP)-induced status epilepticus (SE) to persistent brain injury and abnormal electrical activity that contribute to epilepsy and cognitive impairment. The plasminogen activation system (PAS) promotes neuroinflammation in diverse neurological diseases but whether it is activated following acute OP intoxication has yet to be evaluated. To address this data gap, we characterized the spatiotemporal expression patterns of multiple components of the PAS in a rat model of acute intoxication with the OP, diisopropylfluorophosphate (DFP). Adult male Sprague Dawley rats administered DFP (4 mg/kg, sc), atropine sulfate (2 mg/kg, im) and 2-pralidoxime (25 mg/kg, im) went into SE that persisted for hours. One day after acute DFP-induced SE, plasmin activity and protein concentrations of plasminogen activator inhibitor-1 (PAI-1) in the plasma were increased, though not significantly. In contrast, acute DFP intoxication significantly increased brain levels of PAI-1, tissue-type plasminogen activator (tPA), urokinase plasminogen activator (uPA), and transcripts of TGF-β in a time- and region-dependent manner. In the cortex and hippocampus, quantification of PAI-1, tPA, and uPA by ELISA indicated significantly increased levels at 1 day post-exposure (DPE). PAI-1 and uPA returned to control values by 7 DPE while tPA protein remained elevated at 28 DPE. Immunohistochemistry detected elevated PAI-1 expression in the DFP brain up to 28 DPE. Co-localization of PAI-1 with biomarkers of neurons, microglia, and astrocytes demonstrated that PAI-1 localized predominantly to a subpopulation of astrocytes. Cytologically, PAI-1 localized to astrocytic end feet, but not adjacent neurovascular endothelium. Electron microscopy revealed neuronal metabolic stress and neurodegeneration with disruption of adjacent neurovascular units in the hippocampus post-DFP exposure. These data indicate that acute DFP intoxication altered PAS expression in the brain, with aberrant PAI-1 expression in a subset of reactive astrocyte populations.

Optimizing Medical Care during a Nerve Agent Mass Casualty Incident Using Computer Simulation

INTRODUCTION

Chemical mass casualty incidents (MCIs) pose a substantial threat to public health and safety, with the capacity to overwhelm healthcare infrastructure and create societal disorder. Computer simulation systems are becoming an established mechanism to validate these plans due to their versatility, cost-effectiveness and lower susceptibility to ethical problems.

METHODS

We created a computer simulation model of an urban subway sarin attack analogous to the 1995 Tokyo sarin incident. We created and combined evacuation, dispersion and victim models with the SIMEDIS computer simulator. We analyzed the effect of several possible approaches such as evacuation policy ('Scoop and Run' vs. 'Stay and Play'), three strategies (on-site decontamination and stabilization, off-site decontamination and stabilization, and on-site stabilization with off-site decontamination), preliminary triage, victim distribution methods, transport supervision skill level, and the effect of search and rescue capacity.

RESULTS

Only evacuation policy, strategy and preliminary triage show significant effects on mortality. The total average mortality ranges from 14.7 deaths in the combination of off-site decontamination and Scoop and Run policy with pretriage, to 24 in the combination of onsite decontamination with the Stay and Play and no pretriage.

CONCLUSION

Our findings suggest that in a simulated urban chemical MCI, a Stay and Play approach with on-site decontamination will lead to worse outcomes than a Scoop and Run approach with hospital-based decontamination. Quick transport of victims in combination with on-site antidote administration has the potential to save the most lives, due to faster hospital arrival for definitive care.

Mitigation of pesticide-mediated ocular toxicity via nanotechnology-based contact lenses: a review

The xenobiotic stress exerted by pesticides leads to the deterioration of human and animal health including ocular health. Acute or prolonged exposure to these agricultural toxicants has been implicated in a number of pathological conditions of the eye such as irritation, epiphora or hyper-lacrimation, abrasions on the ocular surface, and decreased visual acuity. The issue is compounded by the fact that tissues of the eye absorb pesticides faster than other organs of the body and are more susceptible to damage as well. However, there is a lacuna in our knowledge regarding the ways by which pesticide exposure-mediated ocular insult might be counteracted. Topical instillation of drugs known to combat the pesticide induced toxicity has been explored to mitigate the detrimental impact of pesticide exposure. However, topical eye drop solutions exhibit very low bioavailability and limited drug residence duration in the tear film decreasing their efficacy. Contact lenses have been explored in this respect to increase bioavailability of ocular drugs, while nanoparticles have lately been utilized to increase drug bioavailability and increase drug residence duration in different tissues. The current review focuses on drug delivery and futuristic aspects of corneal protection from ocular toxicity using contact lenses.

Evidence of nerve agent VX exposure in rat plasma by detection of albumin-adducts in vitro and in vivo

VX is a highly toxic organophosphorus nerve agent that reacts with a variety of endogenous proteins such as serum albumin under formation of adducts that can be targeted by analytical methods for biomedical verification of exposure. Albumin is phosphonylated by the ethyl methylphosphonic acid moiety (EMP) of VX at various tyrosine residues. Additionally, the released leaving group of VX, 2-(diisopropylamino)ethanethiol (DPAET), may react with cysteine residues in diverse proteins. We developed and validated a microbore liquid chromatography-electrospray ionization high-resolution tandem mass spectrometry (µLC-ESI MS/HR MS) method enabling simultaneous detection of three albumin-derived biomarkers for the analysis of rat plasma. After pronase-catalyzed cleavage of rat plasma proteins single phosphonylated tyrosine residues (Tyr-EMP), the Cys34(-DPAET)Pro dipeptide as well as the rat-specific LeuProCys448(-DPAET) tripeptide were obtained. The time-dependent adduct formation in rat plasma was investigated in vitro and biomarker formation during proteolysis was optimized. Biomarkers were shown to be stable for a minimum of four freeze-and-thaw cycles and for at least 24 h in the autosampler at 15 °C thus making the adducts highly suited for bioanalysis. Cys34(-DPAET)Pro was superior compared to the other serum biomarkers considering the limit of identification and stability in plasma at 37 °C. For the first time, Cys34(-DPAET)Pro was detected in in vivo specimens showing a time-dependent concentration increase after subcutaneous exposure of rats underlining the benefit of the dipeptide disulfide biomarker for sensitive analysis.

Creating realistic nerve agent victim profiles for computer simulation of medical CBRN disaster response

In the last decades, Chemical, Biological, Radiological and Nuclear (CBRN) threats have become serious risks prompting countries to prioritize preparedness for such incidents. As CBRN scenarios are very difficult and expensive to recreate in real life, computer simulation is particularly suited for assessing the effectiveness of contingency plans and identifying areas of improvement. These computer simulation exercises require realistic and dynamic victim profiles, which are unavailable in a civilian context. In this paper we present a set of civilian nerve agent injury profiles consisting of clinical parameters and their evolution, as well as the methodology used to create them. These injury profiles are based on military injury profiles and adapted to the civilian population, using sarin for the purpose of illustration. They include commonly measured parameters in the prehospital setting. We demonstrate that information found in military sources can easily be adjusted for a civilian population using a few simple assumptions and validated methods. This methodology can easily be expanded to other chemical warfare agents as well as different ways of exposure. The resulting injury profiles are generic so they can also be used in tabletop and live simulation exercises. Modeling and simulation, if used correctly and in conjunction with empirical data gathered from lessons learned, can assist in providing the evidence practices for effective and efficient response decisions and interventions, considering the contextual factors of the affected area and the specific disaster scenario.

A Review of the Mental Health Sequelae of the SARS-CoV-2 (COVID-19): Preparedness Perspective

Despite the three significant epidemics that have rattled the world in the last two decades, many questions remain unanswered! The concept of unwanted psychological distress remains looming after any epidemic or pandemic. The public health burden of the COVID-19 pandemic still resonates with different aspects of life with predicted mental health sequelae. This review will focus on the role of natural disasters and past infectious epidemic-related mental health complications. Additionally, the study provides recommendations and policy suggestions for mitigating COVID-19-related mental health prevalence.

Recent Trends in SERS-Based Plasmonic Sensors for Disease Diagnostics, Biomolecules Detection, and Machine Learning Techniques

Surface-enhanced Raman spectroscopy/scattering (SERS) has evolved into a popular tool for applications in biology and medicine owing to its ease-of-use, non-destructive, and label-free approach. Advances in plasmonics and instrumentation have enabled the realization of SERS's full potential for the trace detection of biomolecules, disease diagnostics, and monitoring. We provide a brief review on the recent developments in the SERS technique for biosensing applications, with a particular focus on machine learning techniques used for the same. Initially, the article discusses the need for plasmonic sensors in biology and the advantage of SERS over existing techniques. In the later sections, the applications are organized as SERS-based biosensing for disease diagnosis focusing on cancer identification and respiratory diseases, including the recent SARS-CoV-2 detection. We then discuss progress in sensing microorganisms, such as bacteria, with a particular focus on plasmonic sensors for detecting biohazardous materials in view of homeland security. At the end of the article, we focus on machine learning techniques for the (a) identification, (b) classification, and (c) quantification in SERS for biology applications. The review covers the work from 2010 onwards, and the language is simplified to suit the needs of the interdisciplinary audience.

A survey of the antidote preparedness in Norwegian hospitals

OBJECTIVES

Antidotes are an important part of the emergency preparedness in hospitals. In the case of a major chemical accident or a fire, large quantities of antidotes may be needed within a short period of time. For time-critical antidotes it is therefore necessary that they be immediately available. We wanted to evaluate the antidote preparedness in Norwegian hospitals as regards the national recommendations and compare this with other international guidelines.

METHODS

A digital survey was sent to the 50 hospitals in Norway that treat acute poisonings. Of these, four hospitals are categorised as regional hospitals, 15 as large hospitals and 31 as small hospitals. Each hospital was asked which antidotes they stockpiled from a list of 35 antidotes. The financial costs (low, moderate, high) were added to an established efficacy scale to illustrate the cost-effectiveness of the different antidotes.

RESULTS

The response rate was 100%. Eleven of fifty (22%) hospitals stockpiled all antidotes recommended for their hospital size. All four regional hospitals had all the recommended antidotes. Large hospitals which were not regional hospitals had the least availability of antidotes, and only one large hospital stockpiled all antidotes recommended for this hospital size.

CONCLUSIONS

We found varying compliance with the national recommendations for antidote storage in hospitals. To strengthen antidote preparedness, we recommend standardised European guidelines to support national guidelines.

Long-Term Anxiety-Like Behavior and Microbiota Changes Induced in Mice by Sublethal Doses of Acute Sarin Surrogate Exposure

Anxiety disorder is one of the most reported complications following organophosphorus (OP) nerve agent (NA) exposure. The goal of this study was to characterize the long-term behavioral impact of a single low dose exposure to 4-nitrophenyl isopropyl methylphosphonate (NIMP), a sarin surrogate. We chose two different sublethal doses of NIMP, each corresponding to a fraction of the median lethal dose (one mild and one convulsive), and evaluated behavioral changes over a 6-month period following exposure. Mice exposed to both doses showed anxious behavior which persisted for six-months post-exposure. A longitudinal magnetic resonance imaging examination did not reveal any anatomical changes in the amygdala throughout the 6-month period. While no cholinesterase activity change or neuroinflammation could be observed at the latest timepoint in the amygdala of NIMP-exposed mice, important modifications in white blood cell counts were noted, reflecting a perturbation of the systemic immune system. Furthermore, intestinal inflammation and microbiota changes were observed at 6-months in NIMP-exposed animals regardless of the dose received. This is the first study to identify long-term behavioral impairment, systemic homeostasis disorganization and gut microbiota alterations following OP sublethal exposure. Our findings highlight the importance of long-term care for victims of NA exposure, even in asymptomatic cases.

Broad Spectrum Treatment for Ocular Insult Induced by Organophosphate Chemical Warfare Agents

Warfare organophosphates nerve agents constitute one of the prime threats to mankind on the battlefield and in the scenario of civilian terror. Exposure to organophosphate (OP) nerve agents dose-dependently result in incapacitation. They affect multiple organs, but the eye is one of the first and most frequently affected. Ocular OP insult may result in long-term miosis, impaired visual function, and ocular pain thus inducing functional incapacitation. The currently recommended military medical doctrine of using 1% atropine eye drops is far from being the optimal treatment. Although effective in reducing ocular pain and the miotic response, this treatment induces long-term mydriasis and cycloplegia promoting photophobia and restricted accommodation, which may result in further impairment in visual function. An optimal treatment must ameliorate the long-term ocular insult enabling rapid return of normal visual function, while avoiding the induction of mydriasis and cycloplegia side effects, which could possibly worsen the visual performance. Optimal treatment should also keep effects of misuse to a minimum. Work done in recent years examined treatments with various anticholinergic drugs alone or used in combination with oxime treatments and may offer improved efficacy in ameliorating the ocular insult. This review is a summary of the applied research in animals and will discuss clinical implications and possible alterations in treatment protocols following OP exposure. Taken together the data points toward the use of topical low concentrations of potent anticholinergic ophthalmic drops such as atropine or homatropine, which rapidly ameliorate the long-term OP-induced ocular insult.

The Tokyo subway sarin attack has long-term effects on survivors: A 10-year study started 5 years after the terrorist incident

Objectives

The Tokyo subway sarin attack in 1995 was an unprecedented act of terrorism that killed 13 people and sickened more than 6,000. The long-term somatic and psychological effects on its victims remain unknown.

Methods

We conducted analyses on the self-rating questionnaire collected annually by the Recovery Support Center (RSC) during the period from 2000 to 2009. The RSC is the only organization that has large-scale follow-up data about sarin attack victims. The prevalence of self-reported symptoms was calculated over 10 years. We also evaluated the prevalence of posttraumatic stress response (PTSR), defined as a score ≥ 25 on the Japanese-language version of the Impact of Event Scale–Revised. The multivariate Poisson regression model was applied to estimate the risk ratios of age, gender, and year factor on the prevalence of PTSR.

Results

Subjects were 747 survivors (12% of the total) who responded to the annual questionnaire once or more during the study period. The prevalence of somatic symptoms, especially eye symptoms, was 60–80% and has not decreased. PTSR prevalence was 35.1%, and again there was no change with time. The multivariate Poisson regression model results revealed “old age” and “female” as independent risk factors, but the passage of time did not decrease the risk of PTSR.

Conclusions

Although symptoms in most victims of the Tokyo subway sarin were transient, this large-scale follow-up data analysis revealed that survivors have been suffering from somatic and psychological long-term effects.

Tuning Butyrylcholinesterase Inactivation and Reactivation by Polymer-Based Protein Engineering

Organophosphate nerve agents rapidly inhibit cholinesterases thereby destroying the ability to sustain life. Strong nucleophiles, such as oximes, have been used as therapeutic reactivators of cholinesterase-organophosphate complexes, but suffer from short half-lives and limited efficacy across the broad spectrum of organophosphate nerve agents. Cholinesterases have been used as long-lived therapeutic bioscavengers for unreacted organophosphates with limited success because they react with organophosphate nerve agents with one-to-one stoichiometries. The chemical power of nucleophilic reactivators is coupled to long-lived bioscavengers by designing and synthesizing cholinesterase-polymer-oxime conjugates using atom transfer radical polymerization and azide-alkyne "click" chemistry. Detailed kinetic studies show that butyrylcholinesterase-polymer-oxime activity is dependent on the electrostatic properties of the polymers and the amount of oxime within the conjugate. The covalent coupling of oxime-containing polymers to the surface of butyrylcholinesterase slows the rate of inactivation of paraoxon, a model nerve agent. Furthermore, when the enzyme is covalently inhibited by paraoxon, the covalently attached oxime induced inter- and intramolecular reactivation. Intramolecular reactivation will open the door to the generation of a new class of nerve agent scavengers that couple the speed and selectivity of biology to the ruggedness and simplicity of synthetic chemicals.

Ocular surface histopathological insult following sarin and VX exposure and potential treatments in the rat model

Eye exposure to organophosphate (OP) chemical warfare irreversible acetylcholinesterase inhibitors, results in long-term miosis and impaired visual function. In contrast to the well-documented miotic and ciliary muscle spasm observed following chemical warfare, OP ocular exposure, little is known regarding the ocular surface histopathological insult. The aim of the present study was to determine the degree of the ocular surface insult following sarin or VX ocular exposure and to evaluate potential anti-cholinergic treatments in counteracting this insult. Rats that were whole body exposed to various sarin concentrations (0.049-43 μg/L; 5 min exposure), showed a dose-dependent miotic response and light reflex impairment. Following whole body sarin exposure, a dose dependent ocular surface histopathological insult was developed. A week following exposure to a low concentration of 0.05 μg/L, conjunctival pathology was observed, while corneal insult was noticed only following exposure to a concentration of 0.5 μg/L and above. Both tissues presented poorer outcomes when exposed to higher sarin concentrations. In contrast, eyes topically exposed to 1 μg sarin demonstrated no ocular insult a week following exposure. On the contrary, topical exposure to 1 μg VX resulted in a significant corneal insult. Anticholinergic treatments such as 0.1% atropine or 2% homatropine, given shortly following VX exposure, counteracted this insult. The results of this study show that not only do anti-cholinergic treatments counteract the miotic response, but also prevent the histopathological insult observed when given shortly following OP exposure.

Characterizing Chemical Terrorism Incidents Collected by the Global Terrorism Database, 1970-2015

BACKGROUND

The Global Terrorism Database (GTD) is an open-source database on terrorist incidents around the world since 1970, and it is maintained by the National Consortium for the Study of Terrorism and Responses to Terrorism (START; College Park, Maryland USA), a US Department of Homeland Security Center of Excellence. The consortium reviews media reports to determine if an event meets eligibility to be categorized as a terrorism incident for entry into the database.

OBJECTIVE

The objective of this study was to characterize chemical terrorism incidents reported to the GTD and understand more about the kinds of chemical agents used, the associated morbidity and mortality, the geography of incidents, and the intended targets.

METHODS

Chemical terrorism incidents from 1970 through 2015 were analyzed by chemical agent category, injury and fatality, geographic region, and target.

RESULTS

During the study period, 156,772 terrorism incidents were reported to the GTD, of which 292 (0.19%) met the inclusion criteria for analysis as a chemical terrorism incident. The reported chemical agent categories were: unknown chemical (30.5%); corrosives (23.3%); tear gas/mace (12.3%); unspecified gas (11.6%); cyanide (8.2%); pesticides (5.5%); metals (6.5%); and nerve gas (2.1%). On average, chemical terrorism incidents resulted in 51 injuries (mean range across agents: 2.5-1,622.0) and seven deaths (mean range across agents: 0.0-224.3) per incident. Nerve gas incidents (2.1%) had the highest mean number of injuries (n = 1,622) and fatalities (n = 224) per incident. The highest number of chemical terrorism incidents occurred in South Asia (29.5%), Western Europe (16.8%), and Middle East/North Africa (13.0%). The most common targets were private citizens (19.5%), of which groups of women (22.8%) were often the specific target. Incidents targeting educational institutions often specifically targeted female students or teachers (58.1%).

CONCLUSIONS

Chemical terrorism incidents rarely occur; however, the use of certain chemical terrorism agents, for example nerve gas, can cause large mass-causality events that can kill or injure thousands with a single use. Certain regions of the world had higher frequency of chemical terrorism events overall, and also varied in their frequencies of the specific chemical terrorism agent used. Data suggest that morbidity and mortality vary by chemical category and by region. Results may be helpful in developing and optimizing regional chemical terrorism preparedness activities.

Persons injured in the 2011 terror attacks in Norway - Relationship between post-traumatic stress symptoms, emotional distress, fatigue, sleep, and pain outcomes, and medical and psychosocial factors

Purpose: The main aim was to assess long-term post-traumatic stress symptoms, emotional distress, fatigue, sleep disturbances and pain in individuals hospitalized with physical injuries after two terror attacks in Oslo in 2011, approximately three years after the events. A secondary aim was to explore the relationship between these outcomes and medical and psychosocial factors.Materials and methods: Thirty of 43 potential persons participated. Injury characteristics were collected from medical charts. Level of post-traumatic stress, emotional distress, fatigue, sleep disturbances and pain was assessed and the association with injury severity, resilience, optimism, neuroticism and extroversion, and perceived access to social support was explored.Results: Nine of 30 met criteria for full or partial PTSD, and 14 of 30 displayed clinical levels of emotional distress. Fifteen reported moderate to severe fatigue, and 16 said sleep disturbances affected their daily life. Twelve indicated that pain affected daily activities and work ability, and 15 that pain affected their quality of life. I Resilience, optimism, neuroticism, and perceived social support, were associated with outcomes, but injury severity was not. When controlling for pain, many of the psychosocial variables failed to reach significance.Conclusions: Injury severity was not associated with outcomes. On the other hand, psychosocial factors were, but seemed to be influenced by pain.Implications for rehabilitationPersons who have obtained physical injuries under extreme psychological conditions such as terror, are at high risk of poor long-term outcomes, and will often be in need of comprehensive interdisciplinary rehabilitation services.Psychological outcomes are not associated with severity of physical injury, but premorbid and current psychological variables such as resilience, optimism, personality, and access to social support are highly associated with long-term outcome.Longstanding pain seems to diminish or weaken the role of protective psychological factors and should be addressed in the rehabilitation context.

Positron emission tomography studies of organophosphate chemical threats and oxime countermeasures

There is a unique in vivo interplay involving the mechanism of inactivation of acetylcholinesterase (AChE) by toxic organophosphorus (OP) compounds and the restoration of AChE activity by oxime antidotes. OP compounds form covalent adducts to this critical enzyme target and oximes are introduced to directly displace the OP from AChE. For the most part, the in vivo inactivation of AChE leading to neurotoxicity and antidote-based therapeutic reversal of this mechanism are well understood, however, these molecular-level events have not been evaluated by dynamic imaging in living systems at millimeter resolution. A deeper understanding of these critically, time-dependent mechanisms is needed to develop new countermeasures. To address this void and to help accelerate the development of new countermeasures, positron-emission tomography (PET) has been investigated as a unique opportunity to create platform technologies to directly examine the interdependent toxicokinetic/pharmacokinetic and toxicodynamic/pharmacodynamic features of OPs and oximes in real time within live animals. This review will cover two first-in-class PET tracers representing an OP and an oxime antidote, including their preparation, requisite pharmacologic investigations, mechanistic interpretations, biodistribution and imaging.

Complex View on Poisoning with Nerve Agents and Organophosphates

OP/nerve agents are still considered as important chemicals acting on living organisms and widely used in human practice. Nerve agents are the most lethal chemical warfare agents. They are characterized according to their action as compounds influencing cholinergic nerve transmission via inhibition of AChE. The symptoms of intoxication comprise nicotinic, muscarinic and central symptoms, for some OP/nerve agents, a delayed neurotoxicity is observed. Cholinesterases (AChE and BuChE) are characterized as the main enzymes involved in the toxic effect of these compounds including their molecular forms. The activity of both enzymes (and molecular forms) is influenced by inhibitors and other factors such as pathological states. There are different methods for cholinesterase determination, however, the most frequent is the method based on the hydrolysis of thiocholine esters and following detection of free SH-group of the released thiocholine. The diagnosis of OP/nerve agents poisoning is based on anamnesis, the clinical status of the intoxicated organism and on cholinesterase determination in the blood. Some principles of prophylaxis against OP/nerve agents poisoning comprising the administration of reversible cholinesterase inhibitors such as pyridostigmine (alone or in combination with other drugs), scavengers such as preparations of cholinesterases, some therapeutic drugs and possible combinations are given. Basic principles of the treatment of nerve agents/OP poisoning are described. New drugs for the treatment are under experimental study based on new approaches to the mechanism of action.

Evaluating mice lacking serum carboxylesterase as a behavioral model for nerve agent intoxication

Mice and other rodents are typically utilized for chemical warfare nerve agent research. Rodents have large amounts of carboxylesterase in their blood, while humans do not. Carboxylesterase nonspecifically binds to and detoxifies nerve agent. The presence of this natural bioscavenger makes mice and other rodents poor models for studies identifying therapeutics to treat humans exposed to nerve agents. To obviate this problem, a serum carboxylesterase knockout (Es1 KO) mouse was created. In this study, Es1 KO and wild type (WT) mice were assessed for differences in gene expression, nerve agent (soman; GD) median lethal dose (MLD) values, and behavior prior to and following nerve agent exposure. No expression differences were detected between Es1 KO and WT mice in more than 34 000 mouse genes tested. There was a significant difference between Es1 KO and WT mice in MLD values, as the MLD for GD-exposed WT mice was significantly higher than the MLD for GD-exposed Es1 KO mice. Behavioral assessments of Es1 KO and WT mice included an open field test, a zero maze, a Barnes maze, and a sucrose preference test (SPT). While sex differences were observed in various measures of these tests, overall, Es1 KO mice behaved similarly to WT mice. The two genotypes also showed virtually identical neuropathological changes following GD exposure. Es1 KO mice appear to have an enhanced susceptibility to GD toxicity while retaining all other behavioral and physiological responses to this nerve agent, making the Es1 KO mouse a more human-like model for nerve agent research.

A primer on nerve agents: what the emergency responder, anesthesiologist, and intensivist needs to know

PURPOSE

The purpose of this review article is to familiarize first responders, anesthesiologists, and intensivists with the medical management of patients exposed to nerve agents.

SOURCE

This review is based on the current medical literature available to the general medical community.

PRINCIPAL FINDINGS

Nerve agents are some of the deadliest substances known to humanity. Though they kill primarily via muscle paralysis, which leads to respiratory arrest, these agents affect virtually every organ system in the body. Their primary mechanism of action is the body-wide inhibition of cholinesterases. This inhibition leads to the accumulation of acetylcholine, stimulating both nicotinic and muscarinic receptors. After decontamination, the primary treatment is with atropine to control muscarinic symptoms and with oximes to reactivate the cholinesterases and treat the nicotinic symptoms. Atropine doses can be much higher than conventionally used. Seizures are generally best treated with benzodiazepines. Patients with substantial exposure may require ventilatory and intensive care unit support for prolonged periods of time.

CONCLUSION

While it is unlikely that most medical practitioners will ever encounter nerve agent poisoning, it is critical to be aware of the presenting symptoms and how best to treat patients exposed to these deadly agents. History has shown that rapid medical treatment can easily mean the difference between life and death for a patient in this situation.

Planarian cholinesterase: in vitro characterization of an evolutionarily ancient enzyme to study organophosphorus pesticide toxicity and reactivation

The freshwater planarian Dugesia japonica has recently emerged as an animal model for developmental neurotoxicology and found to be sensitive to organophosphorus (OP) pesticides. While previous activity staining of D. japonica, which possess a discrete cholinergic nervous system, has shown acylthiocholine catalysis, it is unknown whether this is accomplished through an acetylcholinesterase (AChE), butyrylcholinesterase (BChE), or a hybrid esterase and how OP exposure affects esterase activity. Here, we show that the majority of D. japonica cholinesterase (DjChE) activity departs from conventional AChE and BChE classifications. Inhibition by classic protonable amine and quaternary reversible inhibitors (ethopropazine, donepezil, tacrine, edrophonium, BW284c51, propidium) shows that DjChE is far less sensitive to these inhibitors than human AChE, suggesting discrete differences in active center and peripheral site recognition and structures. Additionally, we find that different OPs (chlorpyrifos oxon, paraoxon, dichlorvos, diazinon oxon, malaoxon) and carbamylating agents (carbaryl, neostigmine, physostigmine, pyridostigmine) differentially inhibit DjChE activity in vitro. DjChE was most sensitive to diazinon oxon and neostigmine and least sensitive to malaoxon and carbaryl. Diazinon oxon-inhibited DjChE could be reactivated by the quaternary oxime, pralidoxime (2-PAM), and the zwitterionic oxime, RS194B, with RS194B being significantly more potent. Sodium fluoride (NaF) reactivates OP-DjChE faster than 2-PAM. As one of the most ancient true cholinesterases, DjChE provides insight into the evolution of a hybrid enzyme before the separation into distinct AChE and BChE enzymes found in higher vertebrates. The sensitivity of DjChE to OPs and capacity for reactivation validate the use of planarians for OP toxicology studies.

Issues in Chemical and Biological Terrorism

This manuscript describes the overview presented at the 23rd Annual Meeting of the American College of Toxicology in 2002. Although it is recognized that weapons of mass destruction that can be used against our military and civilian populations include chemical, biological, radiological, and nuclear (CBRN) agents, this overview is limited primarily to chemical and biological (CB) agents. The issues of CB terrorism are discussed in terms of When, What, How, and Who. The US Army has been providing chemical and biological solutions since 1917, and has since 1996 applied these solutions to homeland defense and domestic preparedness. The use of chemical and biological agents as terrorist weapons both in the United States and elsewhere in the world is reviewed. The CB threat spectrum is presented, as is the further categorization of biological threat agents by the Centers for Disease Control and Prevention (CDC). In addition, the CB agents considered to be a potential threat to our water supply are also presented. These are agents that are water soluble, stable, and resistant to water treatment and/or disinfection. The overview concludes with the chronological accomplishments of ECBC since 1917.

Chest Compression With Personal Protective Equipment During Cardiopulmonary Resuscitation: A Randomized Crossover Simulation Study

Following a chemical, biological, radiation, and nuclear incident, prompt cardiopulmonary resuscitation (CPR) procedure is essential for patients who suffer cardiac arrest. But CPR when wearing personal protection equipment (PPE) before decontamination becomes a challenge for healthcare workers (HCW). Although previous studies have assessed the impact of PPE on airway management, there is little research available regarding the quality of chest compression (CC) when wearing PPE.A present randomized cross-over simulation study was designed to evaluate the effect of PPE on CC performance using mannequins.The study was set in one university medical center in the China.Forty anesthesia residents participated in this randomized cross-over study.Each participant performed 2 min of CC on a manikin with and without PPE, respectively. Participants were randomized into 2 groups that either performed CC with PPE first, followed by a trial without PPE after a 180-min rest, or vice versa.CPR recording technology was used to objectively quantify the quality of CC. Additionally, participants' physiological parameters and subjective fatigue score values were recorded.With the use of PPE, a significant decrease of the percentage of effective compressions (41.3 ± 17.1% with PPE vs 67.5 ± 15.6% without PPE, P < 0.001) and the percentage of adequate compressions (67.7 ± 18.9% with PPE vs 80.7 ± 15.5% without PPE, P < 0.001) were observed. Furthermore, the increases in heart rate, mean arterial pressure, and subjective fatigue score values were more obvious with the use of PPE (all P < 0.01).We found significant deterioration of CC performance in HCW with the use of a level-C PPE, which may be a disadvantage for enhancing survival of cardiac arrest.

Repeated systemic administration of the nutraceutical alpha-linolenic acid exerts neuroprotective efficacy, an antidepressant effect and improves cognitive performance when given after soman exposure

Exposure to nerve agents results in severe seizures or status epilepticus caused by the inhibition of acetylcholinesterase, a critical enzyme that breaks down acetylcholine to terminate neurotransmission. Prolonged seizures cause brain damage and can lead to long-term consequences. Current countermeasures are only modestly effective against the brain damage supporting interest in the evaluation of new and efficacious therapies. The nutraceutical alpha-linolenic acid (LIN) is an essential omega-3 polyunsaturated fatty acid that has a wide safety margin. Previous work showed that a single intravenous injection of alpha-linolenic acid (500 nmol/kg) administered before or after soman significantly protected against soman-induced brain damage when analyzed 24h after exposure. Here, we show that administration of three intravenous injections of alpha-linolenic acid over a 7 day period after soman significantly improved motor performance on the rotarod, enhanced memory retention, exerted an anti-depressant-like activity and increased animal survival. This dosing schedule significantly reduced soman-induced neuronal degeneration in four major vulnerable brain regions up to 21 days. Taken together, alpha-linolenic acid reduces the profound behavioral deficits induced by soman possibly by decreasing neuronal cell death, and increases animal survival.

Assessing Community Reactions to Ebola Virus Disease and Other Disasters: Using Social Psychological Research to Enhance Public Health and Disaster Communications

Drawing on the lessons learned from previous disaster and disease outbreak studies over the past two decades, in the following article we review research related to social psychological assessment of community attitudes, knowledge, and beliefs associated with the recent Ebola outbreak and other public health threats, and discuss the use of this information to assist in future disaster planning and crisis communications. Psychologists, physicians, and others in the healthcare field need to be aware of these developments and involved with preparations related to mitigating the psychological impact of Ebola disease outbreaks among different populations, as well as other potential public health threats in the future.

Efficacy assessment of a combined anticholinergic and oxime treatment against topical sarin-induced miosis and visual impairment in rats

BACKGROUND AND PURPOSE

Eye exposure to the organophosphorus (OP) irreversible cholinesterase inhibitor sarin results in long-term miosis and impaired visual function. We have previously shown that tropicamide is better at ameliorating this insult than topical atropine or cyclopentolate. However, to minimize side effects associated with repeated tropicamide applications and high treatment doses, we evaluated the effects of oximes (ChE re-activators) alone and combined with tropicamide at ameliorating OP-induced ocular impairments.

EXPERIMENTAL APPROACH

Rats were topically exposed to sarin, followed by topical treatment with various oximes alone or in combination with tropicamide. Pupil width and light reflex were measured by an infrared-based digital photograph system, while visual performance was assessed by employing the cueing version of the Morris water maze (MWM).

KEY RESULTS

Oxime treatment following sarin ocular exposure induced a slow persistent pupil widening with efficacy in the order of HLö-7 > HI-6 > obidoxime = TMB-4 = MMB-4. In the light reflex test, the ability of the iris to contract following oxime treatment was mostly impaired at 1 h and was back to normal at 4 h following sarin exposure. All oxime treatments ameliorated the sarin-induced visual impairment as tested in the visual task (MWM). The combined topical treatment of tropicamide with an oxime induced a rapid improvement in pupil widening, light reflex and visual performance, and enabled a reduction in tropicamide dose.

CONCLUSIONS AND IMPLICATIONS

The use of tropicamide combined with an oxime should be considered as the topical treatment of choice against the toxic effects of ocular OP exposure.

Building a National Model of Public Mental Health Preparedness and Community Resilience: Validation of a Dual-Intervention, Systems-Based Approach

Objective

Working within a series of partnerships among an academic health center, local health departments (LHDs), and faith-based organizations (FBOs), we validated companion interventions to address community mental health planning and response challenges in public health emergency preparedness.

Methods

We implemented the project within the framework of an enhanced logic model and employed a multi-cohort, pre-test/post-test design to assess the outcomes of 1-day workshops in psychological first aid (PFA) and guided preparedness planning (GPP). The workshops were delivered to urban and rural communities in eastern and midwestern regions of the United States. Intervention effectiveness was based on changes in relevant knowledge, skills, and attitudes (KSAs) and on several behavioral indexes.

Results

Significant improvements were observed in self-reported and objectively measured KSAs across all cohorts. Additionally, GPP teams proved capable of producing quality drafts of basic community disaster plans in 1 day, and PFA trainees confirmed upon follow-up that their training proved useful in real-world trauma contexts. We documented examples of policy and practice changes at the levels of local and state health departments.

Conclusions

Given appropriate guidance, LHDs and FBOs can implement an effective and potentially scalable model for promoting disaster mental health preparedness and community resilience, with implications for positive translational impact.(Disaster Med Public Health Preparedness. 2014;8:511-526)

Biphasic cuirass ventilation is better than bag-valve mask ventilation for resuscitation following organophosphate poisoning

Objective

Exposure to organophosphates (OP) may lead to a life threatening cholinergic crisis with death attributed to a rapidly progressive respiratory failure. In a toxicological mass casualty event involving organophosphate exposure, many of the victims may depend on immediate short-term ventilation to overcome the respiratory distress which may exhaust life supporting resources. In addition, the mandatory use of personal protective gear by first responders emphasizes the need for a noninvasive, easy-to-operate ventilation device. Our objective was to assess the efficacy of MRTX, a Biphasic Cuirass Ventilation device, in comparison with standard bag-valve mask ventilation following acute organophosphate poisoning.

Methods

Pigs were exposed to paraoxon poisoning (1.4 LD₅₀), and treated 8 min later with atropine (0.05 mg/kg). The control group received no further support (n = 9), the two experimental groups received ventilation support initiated 15 min post exposure and lasted for 25 min: one group was ventilated with the commonly used bag-valve mask (Mask group, n = 7) and the other was ventilated with the Biphasic Cuirass Ventilation device (Cuirass group, n = 7). Clinical signs and physiological parameters were monitored during the first hour, and mortality up to 24 h post exposure was recorded.

Results

No mortality was observed in the Cuirass group following OP poisoning, while mortality in the Control and in the Mask groups was high (67% and 71%, respectively). Mouth excretions of the cuirass-ventilated animals were frothy white as in deep suctioning, as opposed to the clear saliva-like appearance of secretions in the other two groups. No further group differences were recorded.

Conclusions

The noninvasive, easy-to-operate Biphasic Cuirass Ventilation device was effective in reducing OP-induced mortality and might be advantageous in an organophosphate mass casualty event. This finding should be validated in further investigations.

Mental health consequences of chemical and radiologic emergencies: a systematic review

This article reviews the literature pertaining to psychological impacts in the aftermath of technological disasters, focusing on the immediate psychological and mental health consequences emergency department physicians and first responders may encounter in the aftermath of such disasters. First receivers see a wide spectrum of psychological distress, including acute onset of psychiatric disorders, the exacerbation of existing psychological and psychiatric conditions, and widespread symptomatology even in the absence of a diagnosable disorder. The informal community support systems that exist after a natural disaster may not be available to communities affected by a technological disaster leading to a need for more formal mental health supportive services.

Understanding public responses to chemical, biological, radiological and nuclear incidents--driving factors, emerging themes and research gaps

This paper discusses the management of public responses to incidents involving chemical, biological, radiological and nuclear materials (CBRN). Given the extraordinary technical and operational challenges of a response to a CBRN release including, but not limited to, hazard detection and identification, casualty decontamination and multi-agency co-ordination, it is not surprising that public psychological and behavioural responses to such incidents have received limited attention by scholars and practitioners alike. As a result, a lack of understanding about the role of the public in effective emergency response constitutes a major gap in research and practice. This limitation must be addressed as a CBRN release has the potential to have wide-reaching psychological and behavioural impacts which, in turn, impact upon public morbidity and mortality rates. This paper addresses a number of key issues: why public responses matter; how responses have been conceptualised by practitioners; what factors have been identified as influencing public responses to a CBRN release and similar extreme events, and what further analysis is needed in order to generate a better understanding of public responses to inform the management of public responses to a CBRN release.

Psychosocial care to affected citizens and communities in case of CBRN incidents: a systematic review

Disasters are associated with a substantial psychosocial burden for affected individuals (including first responders) and communities. Knowledge about how to address these risks and problems is valuable for societies worldwide. Decades of research into post-disaster psychosocial care has resulted in various recommendations and general guidelines. However, as CBRN (chemical, biological, radiological, nuclear) events form a distinctive theme in emergency planning and disaster preparedness, it is important to systematically explore their implications for psychosocial care. The aim of this study is to answer two questions: 1). To what extent does psychosocial care in the case of CBRN events differ from other types of events? 2). How strong is the scientific evidence for the effectiveness of psychosocial care interventions in the context of a CBRN event? A systematic literature review was conducted. Searches were performed in Medline, PsychINFO, Embase and PILOTS. Studies since January 2000 were included and evaluated by independent reviewers. The 39 included studies contain recommendations, primarily based on unsystematic literature reviews, qualitative research and expert opinions. Recommendations address: 1) public risk- and crisis communication, 2) training, education and exercise of responders, 3) support, and 4) psychosocial counselling and care to citizens and responders. Although none of the studies meet the design criteria for effectiveness research, a substantial amount of consensus exists on aspects relevant to CBRN related psychosocial care. Recommendations are similar or complementary to general post-disaster psychosocial care guidelines. Notable differences are the emphasis on risk communication and specific preparation needs. Relevant recurring topics are uncertainty about contamination and health effects, how people will overwhelm health care systems, and the possibility that professionals are less likely to respond. However, the lack of evidence on effectiveness makes it necessary to be careful with recommendations. More evaluation research is absolutely needed.

Efficacy of antidotes (midazolam, atropine and HI-6) on nerve agent induced molecular and neuropathological changes

Background

Recent alleged attacks with nerve agent sarin on civilians in Syria indicate their potential threat to both civilian and military population. Acute nerve agent exposure can cause rapid death or leads to multiple and long term neurological effects. The biochemical changes that occur following nerve agent exposure needs to be elucidated to understand the mechanisms behind their long term neurological effects and to design better therapeutic drugs to block their multiple neurotoxic effects. In the present study, we intend to study the efficacy of antidotes comprising of HI-6 (1-[[[4-(aminocarbonyl)-pyridinio]-methoxy]-methyl]-2-[(hydroxyimino) methyl] pyridinium dichloride), atropine and midazolam on soman induced neurodegeneration and the expression of c-Fos, Calpain, and Bax levels in discrete rat brain areas.

Results

Therapeutic regime consisting of HI-6 (50 mg/kg, i.m), atropine (10 mg/kg, i.m) and midazolam (5 mg/kg, i.m) protected animals against soman (2 × LD₅₀, s.c) lethality completely at 2 h and 80% at 24 h. HI-6 treatment reactivated soman inhibited plasma and RBC cholinesterase up to 40%. Fluoro-Jade B (FJ-B) staining of neurodegenerative neurons showed that soman induced significant necrotic neuronal cell death, which was reduced by this antidotal treatment. Soman increased the expression of neuronal proteins including c-Fos, Bax and Calpain levels in the hippocampus, cerebral cortex and cerebellum regions of the brain. This therapeutic regime also reduced the soman induced Bax, Calpain expression levels to near control levels in the different brain regions studied, except a mild induction of c-Fos expression in the hippocampus.

Conclusion

Rats that received antidotal treatment after soman exposure were protected from mortality and showed reduction in the soman induced expression of c-Fos, Bax and Calpain and necrosis. Results highlight the need for timely administration of better antidotes than standard therapy in order to prevent the molecular and biochemical changes and subsequent long term neurological effects induced by nerve agents.

Ready, Willing, and Able: A Framework for Improving the Public Health Emergency Preparedness System

Every society is exposed periodically to catastrophes and public health emergencies that are broad in scale. Too often, these experiences reveal major deficits in the quality of emergency response. A critical barrier to achieving preparedness for high-quality, system-based emergency response is the absence of a universal framework and common language to guide the pursuit of that goal. We describe a simple but comprehensive framework to encourage a focused conversation to improve preparedness for the benefit of individuals, families, organizations, communities, and society as a whole. We propose that constructs associated with the well-known expression “ready, willing, and able” represent necessary and sufficient elements for a standardized approach to ensure high-quality emergency response across the disparate entities that make up the public health emergency preparedness system. The “ready, willing, and able” constructs are described and specific applications are offered to illustrate the broad applicability and heuristic value of the model. Finally, prospective steps are outlined for initiating and advancing a dialogue that may directly lead to or inform already existing efforts to develop quality standards, measures, guidance, and (potentially) a national accreditation program.

(Disaster Med Public Health Preparedness. 2010;4:161-168)

Emergency Mental Health: Lessons Learned From Flight 3407

Emergency mental health (EMH), a field that is often not well represented when considering emergency preparedness, is nonetheless a vital component to any disaster response. Emergency mental health issues must be considered not only for victims of disasters and their families, friends, and coworkers but also for both on-scene and off-scene responders and members of the community who may have witnessed the disaster. This article describes the EMH preparation for and response to the crash of Continental Airlines flight 3407 in western New York on February 12, 2009, killing all 49 crew and passengers on board and 1 person on the ground. It describes aspects of the response that went as planned and highlights areas for improvement. The lessons learned from this EMH preparation and response can be used to inform future planning for disaster response.

(Disaster Med Public Health Preparedness. 2010;4:326-331)

Who Should Worry for the “Worried Well”? Analysis of Mild Casualties Center Drills in Non-Conventional Scenarios

Introduction:

A mass toxicological event (MTE) caused by an act of terrorism or an industrial incident can create large numbers of ambulatory casualties suffering from mild intoxication, acute stress reaction (ASR), and exacerbation of chronic diseases or iatrogenic insult (such as atropine overdose). The logistical and medical management of this population may present a challenge insuch a scenario. The aim of this article is to describe the concept of the Israeli Home Front Command (HFC) of a “Mild Casualties Center” (MCC) for a chemical scenario, and to analyze the results of two large-scale drills that have been used to evaluate this concept.

Methods:

Two large-scale drills were conducted. One MCC drill was located in a school building and the second MCC drill was located in a basketball stadium. These medical centers were staffed by physicians, nurses, and medics, both military (reservists) and civilian (community, non-hospital teams). Two hundred simulated patients entered the MCC during each of the drills, and drill observers assessed how these patients were managed for two hours.

Results:

Of the casualties, 28 were treated in the “medical treatment site”, 10 of which were relocated to a nearby hospital. Only four casualties were treated in the large “mental care site”, planned for a much higher burden of “worried well” patients. Documentation of patient data and medical care was sub-optimal.

Conclusion:

A MCC is a logistically suitable solution for the challenge of managing thousands of ambulatory casualties. The knowledge of the medical team must be bolstered, as most are unfamiliar with both nerve gas poisoning and with ASR. Mild casualties centers should not be located within hospitals and must be staffed by non-hospital, medical personnel to achieve the main task of allowing hospital teams to focus on providing medical care to the moderate and severe nerve gas casualties, without the extra burden of caring for thousands of mild casualties.

Decontamination of Multiple Casualties Who Are Chemically Contaminated: A Challenge for Acute Hospitals

Patients who have been contaminated by chemical compounds present a number of difficulties to emergency departments, in particular, the risk of secondary contamination of healthcare staff and facilities. The Department of Health in the United Kingdom has provided equipment to decontaminate chemically contaminated casualties who present at emergency departments. The capacity of this equipment is limited, and although both the ambulance and fire services have equipment to cope with mass casualties at the scene of a chemical incident, there is still the possibility that acute hospitals will be overwhelmed by large numbers of self-presenting patients. The risks and potential consequences of this gap in resilience are discussed and a number of possible practical solutions are proposed.

Disaster and Terrorism: Cognitive-Behavioral Interventions

The mental health effects of disaster and terrorism have moved to the forefront in the recent past following the events of 11 September 2001 in the United States. Although there has been a protracted history by mental health researchers and practitioners to study, understand, prevent, and treat mental health problems arising as a result of disasters and terrorism, there still is much to learn about the effects and treatment of trauma. Continued communication among disaster workers, first-response medical personnel, and mental health professionals is part of this process. This paper outlines current knowledge regarding the psychological effects of trauma and best cognitive-behavioral practices used to treat trauma reactions. More specifically, the information presented is a summary of Cognitive-Behavioral Therapy (CBT) interventions that are relevant for responding to and dealing with the aftermath of disasters.

Organophosphate-induced brain damage: mechanisms, neuropsychiatric and neurological consequences, and potential therapeutic strategies

Organophosphate (OP)-induced brain damage is defined as progressive damage to the brain, resulting from the cholinergic neuronal excitotoxicity and dysfunction induced by OP-induced irreversible AChE inhibition. This delayed secondary neuronal damage that occurs mainly in the cholinergic regions of the brain that contain dense accumulations of cholinergic neurons and the majority of cholinergic projection, might be largely responsible for persistent profound neuropsychiatric and neurological impairments (memory, cognitive, mental, emotional, motor and sensory deficits) in the victims of OP poisoning. Neuroprotective strategies for attenuating OP-induced brain damage should target different development stages of OP-induced brain damage, and may include but not limited to: (1) Antidote therapies with atropine and related efficient anticholinergic drugs; (2) Anti-excitotoxic therapies targeting attenuation of cerebral edema and inflammatory reaction, blockage of calcium influx, inhibition of apoptosis program, and the control of seizures; (3) Neuroprotective strategies using cytokines, antioxidants and NMDAR antagonists (a single drug or a combination of drugs) to slow down the process of secondary neuronal damage; and (4) Therapies targeting individual symptoms or clusters of chronic neuropsychiatric and neurological symptoms. These neuroprotective strategies may help limit or prevent secondary neuronal damage at the early stage of OP poisoning and attenuate the subsequent neuropsychiatric and neurological impairments, thus reducing the long-term disability caused by exposure to OPs.