Incapacitating agents review: 20 years after Nord Ost Siege.

Incapacitating agents are chemical weapons that produce a temporary disabling condition that persists for hours or days after exposure. Their main site of action is the central nervous system and includes substances that are considered depressants or stimulants. While not intended to cause death, can produce significant morbidity in affected patients. The objective of this narrative review is to update the toxicokinetics, toxicodynamics, diagnosis, and treatment of these chemicals, considering that 20 years have passed since the Nord Ost Siege, where a fentanyl derivative was used by Russian forces to neutralize a group of Chechen dissidents. A bibliographic search was carried out in PubMed, SciELO, and Cochrane Library databases as well as nonindexed scientific literature.

Testing the Novel Weapons Hypothesis of the Argentine Ant Venom on Amphibians.

The globally invasive Argentine ant (Linepithema humile) possesses a venom lethal to some amphibian species in the invaded range. To test the novel weapons hypothesis (NWH), the effects of the toxin on the cohabiting amphibian species in the ant's native range need to be investigated. The invader should benefit from the novel chemical in the invaded range, because the species are not adapted, but the venom should not be effective in the native range. We explore the venom effects on juveniles of three amphibian species with different degrees of myrmecophagy inhabiting the ant's native range: Rhinella arenarum, Odontophrynus americanus, and Boana pulchella. We exposed the amphibians to the ant venom, determined the toxic dose, and evaluated the short- (10 min to 24 h) and medium-term (14 days) effects. All amphibian species were affected by the venom independently of myrmecophagy. In addition to amphibian sensitivity, we discuss how the differential Argentine ant abundance and density in the two ranges could be the key to the susceptibility of amphibians to the venom, resulting in the possibility of NWH. Our results confirm the potential magnitude of the impact of the Argentine ant in successfully invaded areas for the conservation of already threatened amphibians.