Organophosphonates such as isopropyl metylphosphonofluoridate (sarin) are extremely toxic as they phosphonylate the catalytic serine residue of acetylcholinesterase (AChE), an enzyme essential to humans and other species. Design of effective AChE reactivators as antidotes to various organophosphonates requires information on how the reactivators interact with the phosphonylated AChEs. However, ...

This study compared the ability of nine oximes (HI-6, HLö7, MMB-4, TMB-4, carboxime, ICD585, ICD692, ICD3805, and 2-PAM) to reactivate in vivo cholinesterase (ChE) in blood, brain, and peripheral tissues in guinea pigs intoxicated by one of four organophosphorus nerve agents. Two bis-pyridinium compounds without an oxime group, SAD128 and ICD4157, served as non-oxime controls. Animals were inje...

This study was designed to test the hypothesis that the acute toxicity of the nerve agents S-[2-(diisopropylamino)ethyl]-O-ethyl methylphosphonothioate (VX), O-pinacolyl methylphosphonofluoridate (soman), and O-isopropyl methylphosphonofluoridate (sarin) in guinea pigs is age- and sex-dependent and cannot be fully accounted for by the irreversible inhibition of acetylcholinesterase (AChE). The ...

Epinephrine-induced arrhythmias (EPIA) are known to be associated with local cardiac cholinergic activation. The present study examined the development of QT prolongation and the effect on EPIA of whole-body exposure of animals to a potent acetylcholine esterase inhibitor. Freely moving rats were exposed to sarin vapor (34.2 +/- 0.8 microg/liter) for 10 min. The electrocardiograms (ECG) of expo...

I provide a full characterization of the set of absolutely expedient learning rules introduced in Börgers, Morales, and Sarin (2004) [“Expedient and monotone learning rules,” Econometrica, 72, 383–405]. The expected change in the expected payoff can be written as a quadratic form on the vector of relative expected payoffs of the strategies. This permits use of standard linear algebra arguments ...