Tetramethylenedisulfotetramine: pest control gone awry

Highly efficient and precise two-step cell selection method for tetramethylenedisulfotetramine-specific monoclonal antibody production

Monoclonal antibodies (mAbs) are useful biological tools for research, diagnostics, and pharmaceuticals. Here, we proposed a new mAb discovery platform named the two-step cell selection method (TCSM) for mAbs production of some small molecule haptens as antibiotic, toxins, and pesticides. The first step was performed by a fluorescence-activated cell sorter to enrich the hapten-specific B cells, the second step was an image-based precise pick of single hapten-specific hybridoma cells by confocal laser scanning microscopy. In this study, we used tetramethylenedisulfotetramine (TETS) as a model analyte, which is a highly lethal neurotoxic rodenticide. The TETS-specific hybridoma cells selection was completed within 10 days by the TCSM, compared with at least 40 days in the traditional hybridoma method (THM). The half maximal inhibitory concentration (IC₅₀) of the best mAb 1G6 for TETS in the TCSM was 1.98 ng mL^-1, and that of mAb 2B6 in the THM was 11.49 ng mL^-1. Antibody-TETS recognition also showed more interactions in mAb 1G6 than in mAb 2B6. Then, the mAb 1G6 was then successfully applied to develop an icELISA for TETS in biological samples with satisfactory sensitivity, accuracy and precision. The results demonstrated that the TCSM was a feasible and efficient method for mAb discovering of poisonous hapten molecules.

Strain differences in the extent of brain injury in mice after tetramethylenedisulfotetramine-induced status epilepticus

Acute intoxication with tetramethylenedisulfotetramine (TETS) can trigger status epilepticus (SE) in humans. Survivors often exhibit long-term neurological effects, including electrographic abnormalities and cognitive deficits, but the pathogenic mechanisms linking the acute toxic effects of TETS to chronic outcomes are not known. Here, we use advanced in vivo imaging techniques to longitudinally monitor the neuropathological consequences of TETS-induced SE in two different mouse strains. Adult male NIH Swiss and C57BL/6J mice were injected with riluzole (10 mg/kg, i.p.), followed 10 min later by an acute dose of TETS (0.2 mg/kg in NIH Swiss; 0.3 mg/kg, i.p. in C57BL/6J) or an equal volume of vehicle (10% DMSO in 0.9% sterile saline). Different TETS doses were administered to trigger comparable seizure behavior between strains. Seizure behavior began within minutes of TETS exposure and rapidly progressed to SE that was terminated after 40 min by administration of midazolam (1.8 mg/kg, i.m.). The brains of vehicle and TETS-exposed mice were imaged using in vivo magnetic resonance (MR) and translocator protein (TSPO) positron emission tomography (PET) at 1, 3, 7, and 14 days post-exposure to monitor brain injury and neuroinflammation, respectively. When the brain scans of TETS mice were compared to those of vehicle controls, subtle and transient neuropathology was observed in both mouse strains, but more extensive and persistent TETS-induced neuropathology was observed in C57BL/6J mice. In addition, one NIH Swiss TETS mouse that did not respond to the midazolam therapy, but remained in SE for more than 2 h, displayed robust neuropathology as determined by in vivo imaging and confirmed by FluoroJade C staining and IBA-1 immunohistochemistry as readouts of neurodegeneration and neuroinflammation, respectively. These findings demonstrate that the extent of injury observed in the mouse brain after TETS-induced SE varied according to strain, dose of TETS and/or the duration of SE. These observations suggest that TETS-intoxicated humans who do not respond to antiseizure medication are at increased risk for brain injury.

Mouse model of human poisonings with tetramethylenedisulfotetramine: Characterization of the effect of exposure route on syndrome outcomes

Tetramethylenedisulfotetramine (TMDT) is a synthetic neurotoxic rodenticide and potential chemical threat agent. Signs of TMDT poisoning include convulsions which can progress into status epilepticus and death. Although clinical reports clearly show that poisoning via food and drink is the main route of exposure, experimental studies have primarily utilized parenteral routes. Here we used two different modes of oral administration of TMDT and compared the toxic outcomes with two different parenteral routes. Adult male mice were given various doses of TMDT either perorally in peanut butter or cereal pellets, or injected intraperitoneally (i.p.) or subcutaneously (s.c.). All routes produced the complete TMDT syndrome including twitches, clonic and tonic-clonic seizures and death. However potencies varied with the following rank order: i.p. > s.c. > oral (cereal)>>oral (peanut butter). Our data clearly show that ingestion of TMDT with peanut butter markedly reduces the overall syndrome severity relative to oral exposure via cereals. No significant differences were observed by substituting peanut oil for water as a vehicle for i.p. administered TMDT. In conclusion, high vs low fat food can differentially affect TMDT onset of action, probably due to differences in availability from the gastrointestinal tract. These results should be considered when searching for effective treatments for TMDT poisoning.

Tetramethylenedisulfotetramine: A Health Risk Compound and a Potential Chemical Warfare Agent

Tetramethylenedisulfotetramine (TETS, tetramine) is a toxic organic compound that is used as an effective rodenticide. However, this neurotoxin is not only toxic to rodents, it also causes poisoning in humans. Due to its high level of toxicity for humans, the use of TETS as a rodenticide has been banned and its production has been discontinued. Despite this, human poisoning by this substance is unfortunately still very common. The largest number of poisonings are reported in China, but in the United States, dozens of poisonings still happen annually. TETS is one of the most hazardous pesticides and also a possible chemical warfare agent with no known antidote. In this article, we aim to summarize the biochemical and toxicological data of TETS and hope to cast some light on the toxicological risk to human health.