Lester G. Sultatos

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Organophosphorus compounds have been utilized as pesticides for almost five decades. They continue to be used as insecticides, helminthicides, ascaricides, nematocides, and to a lesser degree as fungicides and herbicides. While they have been and continue to be extremely useful in agricultural pest control throughout the world, their extensive use has led(More)
The Food Quality Protection Act of 1996 (FQPA) requires the EPA to consider "available information concerning the cumulative effects of such residues and other substances that have a common mechanism of toxicity ... in establishing, modifying, leaving in effect, or revoking a tolerance for a pesticide chemical residue." This directive raises a number of(More)
We review pharmacokinetic and pharmacodynamic factors that should be considered in the design and interpretation of developmental neurotoxicity studies. Toxicologic effects on the developing nervous system depend on the delivered dose, exposure duration, and developmental stage at which exposure occurred. Several pharmacokinetic processes (absorption,(More)
Chlorpyrifos [0,0-diethyl-0-(3,5,6-trichloro-2-pyridyl) phosphorothioate] was metabolized to chlorpyrifos oxon [0,0-diethyl-0-(3,5,6-trichloro-2-pyridyl) phosphate] and to 3,5,6-trichloro-2-pyridinol by mouse hepatic microsomes. Formation of both chlorpyrifos oxon and 3,5,6-trichloro-2-pyridinol required NADPH, and was inhibited by carbon monoxide. Kinetic(More)
Chronic exposure to excessive ethanol consumption has adverse effects on virtually all organs and tissues in the body, including but not limited to the liver, pancreas, reproductive organs, central nervous system, and the fetus. Exposure to ethanol can also enhance the toxicity of other chemicals. Not all persons exposed to the same amount of ethanol(More)
A-esterase(s), an enzyme(s) that hydrolyzes certain organophosphate compounds, is located in mammals, primarily in serum and liver. Although considerable information is available regarding serum A-esterase(s), little is known about the hepatic form(s) of this enzyme. In the present study, hepatic A-esterase activity was quantified by measuring the(More)
The mechanism of acute toxicity of the organophosphorus insecticides has been known for many years to be inhibition of the critical enzyme acetylcholinesterase (EC, with the resulting excess acetylcholine accumulation leading to symptoms of cholinergic excess. The bimolecular inhibition rate constant k(i) has been used for decades to describe the(More)
The apparent (app) Km and app Vmax for mouse hepatic microsomal oxidative detoxification of chlorpyrifos to 3,5,6-tricholoro-2-pyridinol were 16.10 +/- 6.8 microM and 263.2 +/- 22.5 nmol/liver/min, respectively. The app Km and app Vmax for the oxidative activation of chlorpyrifos to chlorpyrifos oxon were 20.0 +/- 6.5 microM and 126.1 +/- 14.6(More)
Diabetic neuropathy is associated with functional and morphological changes of the neuromuscular junction (NMJ) associated with muscle weakness. This study examines the effect of type 1 diabetes on NMJ function. Swiss Webster mice were made diabetic with three interdaily ip injections of streptozotocin (STZ). Mice were severely hyperglycemic within 7 days(More)