Organophosphate chemicals such as herbicides, pesticides, and nerve agents are harmful even in small amounts, thus requiring methods for rapid ultrasensitive detection. Surface-enhanced Raman spectroscopy (SERS) is a leading method for trace-level detection of dissolved chemicals, yet our understanding of the critical influence of the solvent is currently incomplete. Rather than being recognized as a crucial aspect for generating a strong signal enhancement, the solvent is often dismissed as a secondary parameter. This has left the dual impact of solvents on the analyte and SERS substrate properties in relation to SERS largely unexplored. In this work, we evaluated the suitability of common solvents for the detection of nerve agents using SERS on gold nanopillar SERS substrates. Overall, we found large differences in the limit of detection (LOD) between solvents. VX exhibited an LOD of 0.2 ppm in water, compared to 8.7 and 6.3 ppm in ethanol and acetonitrile, respectively, with similar trends for other nerve agents. Dichloromethane and n-hexane were found to be largely ineffective as solvents for SERS in these applications. To explain these differences, we used DFT to model analyte-solvent interactions, showing that high-polarity solvents such as water generate higher electron concentrations in select analyte molecular groups, impacting analyte-substrate interactions. Furthermore, we used Raman mapping, contact angle measurements, and SEM to evaluate solvent-substrate interactions, showing that solvent-dependent capillary forces impact SERS substrate nanogeometry and thus the formation of SERS hotspots. Overall, these results provide insight into the many solvent effects that are relevant to designing future SERS sensing assays.

Organophosphates (OP) and carbamates frequently cause acute poisoning worldwide via acetylcholinesterase inhibition, leading to characteristic cholinergic toxidrome manifestations. However, some agents such as Amitraz, Fipronil, and 2,4-dichlorophenoxyacetic acid act through different mechanisms yet clinically mimic OP poisoning, complicating diagnosis and management. This case series presents three patients exposed to these mimickers, highlighting differing clinical features, investigations, and management strategies. Recognizing these pesticide mimickers is critical to avoid inappropriate therapy and optimize outcomes.

Amitraz (AMT) is a formamidine acaricide widely used in agriculture. The incidence of AMT poisoning shows an increasing trend, yet its neurotoxic effects on non-target organisms remain poorly understood. In this study, zebrafish embryos were used to investigate the developmental and neurobehavioral toxicity of AMT and the underlying mechanisms. Embryos were exposed to varying concentrations of AMT (1, 2.5, and 5 μM) from 4 to 120 h post-fertilization. The results showed that AMT concentration-dependently inhibited embryonic development. Behavioral analyses revealed significant impairments in locomotor activity, including decreased swimming distance and velocity. Mechanistically, AMT exposure was associated with cerebrovascular abnormalities, including vascular disruption and hemorrhage, as well as brain apoptosis, accompanied by oxidative stress and inflammation. Additionally, AMT disrupted energy metabolism and altered multiple neurotransmitter systems, including GABAergic, glutamatergic, and cholinergic pathways. Transcriptomic analysis further confirmed that AMT altered expression of genes involved in oxidative stress, apoptosis, inflammation, cerebrovascular development, BBB-related processes, neurodevelopment and synaptic function. Taken together, AMT triggers developmental toxicity and neurobehavioral deficits in zebrafish, which are associated with cerebrovascular/BBB-related alterations, oxidative stress, impaired neuronal development, and neurotransmitter imbalance. These findings provides insights into the mechanisms underlying AMT-induced neurodevelopmental toxicity in aquatic organisms.

Chlorpyrifos (CPF) is a broad-spectrum chlorinated organophosphate insecticide. It was classified as a persistent organic pollutant under the Stockholm Convention in 2024 due to its harmful effects on the environment and human health, including neurotoxicity. The classical mechanism of CPF-induced neurotoxicity is attributed to acetylcholinesterase inhibition by its metabolite, chlorpyrifos-oxon (CPO), in cholinergic neurons. Emerging studies indicate that CPF also induces toxicity in dopaminergic neurons through mitochondrial dysfunction. In this study, the molecular mechanisms and targets associated with CPF-induced neurotoxicity in humans were investigated using network toxicology, molecular docking, molecular dynamics, and in vitro study. Comprehensive database analyses identified 271 potential targets associated with CPF-induced neurotoxicity. Gene ontology enrichment and gene-gene interaction analyses revealed significant enrichment related to mitochondria and oxidative phosphorylation. Protein-protein interaction and centrality analyses identified 15 hub targets. Molecular docking and molecular dynamics simulations demonstrated that CPF and CPO bind to mitochondrial Complex I, especially with NDUFA2, more strongly than rotenone, a known Complex I inhibitor. In vitro analysis in SH-SY5Y cells demonstrated that CPF impaired mitochondrial complex I-associated activity in a concentration-dependent manner, with significant inhibition observed at concentrations of 75 µM and higher. These findings suggest that CPF, and to a lesser extent CPO, may exert inhibitory effects on mitochondrial complex I in neurons, thereby contributing to neurotoxicity in humans. Overall, these results are in line with previous experimental reports and highlight the effectiveness of integrated computational approaches in identifying key mitochondrial mechanisms involved in CPF-induced neurotoxicity.

The cholinergic system shows promise for pain management. Although cholinergic neurons in the ventral pallidum (VP) are involved in neuropathic pain, the anatomical organization and pharmacology of the cholinergic circuit contributing to the processing of acute and chronic pain remain unknown. In the present study, we demonstrate that VP cholinergic neurons in mice received pain signals from and mediated pain modulation by glutamatergic (Glu) neurons in the subthalamic nucleus (STN) in both physiological and neuropathic pain conditions. VP cholinergic neurons were a major source of acetylcholine released in the VP upon pain stimulation, and α4 and α7 were major subunits comprising functional nicotinic acetylcholine receptors (nAChRs) in VP cholinergic, GABAergic, and Glu neurons. In neuropathic pain mouse models, VP cholinergic neurons became hyperactive and released more acetylcholine in the VP, and α4 and α7 nAChRs were differentially modified on VP GABAergic and Glu neurons. These modifications were accompanied by hyperexcitability in VP GABAergic neurons and hypoactivity in VP Glu neurons. Reversal of upregulated α4 nAChRs on VP GABAergic neurons, but not that of downregulated α4 and α7 nAChRs on VP Glu neurons, attenuated the severity of hyperalgesia in neuropathic pain. Therefore, the STNGlu-VPChAT pathway is implicated in neuropathic pain by enhancing VP cholinergic circuits, and α4 nAChRs on VP GABAergic neurons may be potential therapeutic targets for the treatment of neuropathic pain.

Organophosphate poisoning is a major cause of acute cholinergic toxicity and can progress rapidly to respiratory failure and death. In the emergency setting, diagnosis is often clinical, and treatment should not be delayed while awaiting confirmation of the specific compound. We report a case of a 30-year-old male patient who presented after intentional ingestion of a large reported volume of diazinon-containing pesticide. Within approximately 30 minutes of ingestion, he developed acute cholinergic manifestations, including bradypnea, bradycardia, hypotension, hypersalivation, vomiting, diarrhea, and depressed level of consciousness, complicated by a generalized tonic-clonic seizure. The seizure was treated with diazepam, and atropine was initiated before transfer to the emergency department. On arrival, the patient was in severe respiratory distress with profuse secretions and required urgent endotracheal intubation and mechanical ventilation. Empiric treatment for suspected organophosphate poisoning was continued with atropine and pralidoxime, alongside supportive care. Collateral history later identified the ingested product as Diacidol 600 Emulsifiable Concentrate, containing diazinon 600 g/L, equivalent to 60% weight/volume. Plasma butyrylcholinesterase, red blood cell acetylcholinesterase, and toxicological confirmation testing were not available at our institution at the time of evaluation, which represents a limitation of this report. The patient was admitted to the intensive care unit and managed with atropine and pralidoxime infusions, ventilatory support, and close monitoring for delayed neuromuscular complications. His cholinergic features resolved, and he was successfully extubated within 24 hours. Antidotal therapy was discontinued after sustained clinical improvement, and he remained stable during subsequent ward observation. This case emphasizes that severe organophosphate poisoning remains a clinical diagnosis during initial resuscitation. Early airway protection, titrated atropinization, pralidoxime therapy, benzodiazepines for seizures, and observation for delayed complications are central to favorable outcomes.

Foodborne botulism is a severe neuroparalytic disease caused by ingestion of foods containing botulinum neurotoxins, produced by Clostridium botulinum. In 2024, a 74-year-old woman from Newfoundland and Labrador with complete bilateral flaccid paralysis and respiratory distress was hospitalized and required intubation. From the broader differential diagnosis list, botulism was favoured prior to laboratory confirmation. Serum and feces samples initially tested negative for botulinum neurotoxins by mouse bioassay, yet viable C. botulinum type A was recovered from the feces. Food history investigation included some diced garlic in a repurposed coffee container that tested negative for botulinum neurotoxins by mouse bioassay, but viable C. botulinum type A was recovered from the sample. Both the fecal and garlic enrichment cultures were positive for bont/A and bont/B genes by real-time PCR. Whole genome sequencing revealed that both fecal and garlic isolates were highly similar with conserved gene synteny, including an intact bont/A1 gene and a disrupted (silent) bont/B5 gene encoded on the chromosome. This single-case foodborne botulism outbreak from Newfoundland and Labrador in 2024 was caused by C. botulinum type A1(B5) in diced garlic.

Organophosphates (OP) have a variety of applications, including widespread use as pesticides. Although OP poisoning in the U.S. has been declining, toxicity from intentional ingestions of commercially available preparations is still a concern. We describe a case of a 17-year-old female who intentionally ingested an acephate-based fire ant insecticide and developed severe cholinergic toxicity, despite acephate's classification as a safer OP. The patient was successfully treated with atropine and pralidoxime, but had recurrence of symptoms after long asymptomatic periods requiring repeat dosing, which is atypical. We encourage clinicians to have a low threshold for prolonged observation in these patients, even in the absence of symptoms.

Cervical dystonia (CD) is a focal dystonia typically treated with botulinum toxin type A (BoNT-A), but objective biomarkers of disease state and treatment response are limited. In a prospective controlled observational study with within-subject phase comparison, we evaluated clinical, neurophysiological, and biochemical markers at two time points (waning and peak response phases) within the BoNT-A injection interval in 30 CD individuals (with caput, collis and mixed patterns) and 25 healthy controls. We measured clinical status (TWSTRS and VAS pain), neurophysiology (F-wave minimal latency (F-min) and cutaneous silent period (CSP) indices) and plasma biochemical markers (neurofilament light chain (NfL) and zonulin). Compared with controls, CD patients showed lower NfL levels, higher zonulin, shorter CSP end duration and shorter CSP-derived central conduction time (CSP-CCT); nerve conduction velocity and CSP onset were similar. From waning to peak, TWSTRS (all subscales) and VAS improved, zonulin decreased, NfL increased, CSP end duration and CSP-CCT increased, and Fmin slightly prolonged. Changes in CSP measures correlated with pain (VAS and TWSTRS pain), while zonulin changes showed no significant correlations and NfL changes correlated weakly/negatively with CSP end time. Phase-dependent changes in biochemical and neurophysiological markers were observed alongside clinical measures across the BoNT-A treatment cycle in CD, suggesting potential associations between peripheral biochemical markers, central inhibitory measures, and treatment phase. These findings may warrant further investigation of multimodal biomarker approaches in CD.

Co-contamination of foods with multiple mycotoxins highlights the need for broad-spectrum detoxification enzymes. In this study, Klebsiella pneumoniae HNGD-HS06 was isolated from contaminated peanuts and degraded aflatoxin B1 (AFB1), zearalenone (ZEN), and alternariol (AOH) by 72.52%, 63.42%, and 76.17%, respectively. Genome-guided screening and heterologous expression identified two candidate proteins, HSFtsp and HSCueO. HSCueO shared only 28.08% sequence identity with CotA laccase, while HSFtsp has not previously been associated with mycotoxin degradation. HSFtsp degraded AFB1, ZEN, and AOH by up to 99.16%, 95.12%, and 94.72%, respectively, whereas HSCueO achieved 98.97%, 99.23%, and 99.74% degradation. Product analysis and zebrafish assays suggested that both enzymes transformed these toxins into less toxic products, while molecular docking supported potential enzyme-substrate interactions. Both enzymes retained detoxification activity in contaminated peanut, corn, and wheat flour, expanding enzyme resources for multimycotoxin control in foods.

Botulinum neurotoxin (BoNT) produced by Clostridium botulinum(C. botulinum) could cause botulism in both humans and animals, with a relatively high mortality rate. It is a type of poisoning disease that has garnered widespread global concern. This article aims to systematically compile relevant literature and provide a comprehensive summary of the latest research on C. botulinum and BoNT. It elaborates in detail on the research history of botulism and its classification, the current research advancements both domestically and internationally, detection techniques, clinical treatment, prevention and control measures, the clinical applications of BoNT, as well as future development directions. The goal is to enhance professional understanding of botulism.

Exposure to organophosphorus (OP) compounds can induce transient cognitive, neurological, and somatic symptoms that may persist over time. OP poisoning mostly occurs from pesticides used in developing countries; however, several OP nerve agent (NA) events have been reported in the last decade. OP toxicity is based on cholinesterase inhibition, which leads to varying degrees of neurotoxicity. According to clinical reports, asymptomatic victims of OP exposure may experience long-term neurological sequelae. Given the continuous communication between the nervous and enteric systems, evaluating the neurotoxic effects of OP exposure on the gut-brain axis is important. A male Swiss mouse model was employed to investigate the short- and long-term consequences of acute exposure to a sublethal dose of VX at 0.5 LD50. The investigation focused on alterations in the inflammatory system and the endocrine system, with particular attention to the hypothalamic-pituitary-adrenal (HPA) axis. Additionally, the study encompassed an evaluation of the intestinal barrier structural and functional integrity and gut microbiota composition. A longitudinal behavioral study was also conducted to assess cognitive and emotional functions. Our results indicate that sublethal exposure to a VX disrupts the HPA axis and the intestinal homeostasis as evidenced by local inflammation, structural changes and gut microbiota shifts. Our data also indicate long-term neurological deficits as well as long-term neuroendocrine and metabolic effects suggesting a systemic homeostatic disorder. These findings highlight the necessity for comprehensive care for individuals exposed to NA and underscore the importance of identifying biomarkers for low-dose to sublethal exposure to facilitate early diagnosis and the development of effective treatments.

We report a case of a previously healthy 3-year-old girl who developed acute altered consciousness, agitation, and visual hallucinations consistent with an anticholinergic toxidrome. Initial examinations were unremarkable, and urine immunoassay screening (SIGNIFY™ ER) was negative. Serum analysis by liquid chromatography-quadrupole time-of-flight mass spectrometry identified chlorpheniramine and scopolamine, while excluding other agents. Concentrations were 370 ng/mL for chlorpheniramine and 1 ng/mL for scopolamine, both near reported toxic ranges. An empty blister pack of 22 pediatric motion sickness tablets was found at the patient's home, confirming accidental overdose of an over-the-counter (OTC) anti-motion sickness medication. This case demonstrates the diagnostic utility of high-resolution mass spectrometry in pediatric poisoning, particularly for drugs not detected by routine screening. It represents a rare report documenting quantitative confirmation of both chlorpheniramine and scopolamine in a child, with correlation between serum concentrations and clinical presentation. Scopolamine is highly toxic even at low concentrations, and pediatric cases with measured blood levels are exceedingly rare. Our findings highlight the need to consider additive or synergistic toxicity in OTC formulations containing multiple anticholinergic agents and emphasize the importance of caregiver education regarding the potential risks of OTC medications often perceived as safe.