Oxidative metabolism of the insect repellent N,N-diethyl-m-toluamide (DEET) by pooled human liver microsomes (HLM), rat liver microsomes (RLM), and mouse liver microsomes (MLM) was investigated. DEET is metabolized by cytochromes P450 (P450s) leading to the production of a ring methyl oxidation product, N,N-diethyl-m-hydroxymethylbenzamide (BALC), and an N-deethylated product, N-ethyl-m-toluami...

A larval immersion bioassay was developed to identify susceptibility of onion maggot, Delia antiqua (Meigen) (Diptera: Anthomyiidae), to chlorpyrifos and to determine whether this assay could be used to predict control in onion fields. Laboratory colonies were established from larvae collected in New York onion fields during 2003 and 2004, providing us with test insects to use in bioassays. The...

Human volunteer studies have been conducted by orally administering the pesticides deltamethrin (0.01 mg/kg/day) or pirimicarb (0.02 mg/kg/day) at the acceptable daily intake (ADI) together with chlorpyrifos-methyl (0.01 mg/kg/day), in order to investigate any potential interactions that may occur during dietary exposure. Deltamethrin and pirimicarb are metabolised in vivo by hydrolytic enzymes...

The effects of chlorpyrifos, an organophosphorus insecticide, were examined on the activity of the nervous system enzyme acetylcholinesterase (AChE) in the threeridge mussel Amblema plicata in a 24-day laboratory test. Thirty-six mussels in each of seven treatments (18 mussels per duplicate) were exposed to chlorpyrifos (0.1, 0.2, 0.3, 0.6, and 1.2 mg/L), a solvent (acetone), and a solvent-free...

BACKGROUND Toxicity of organophosphate insecticides is mainly due to the inhibition of acetylcholinesterase (AChE). However, organophosphate insecticides in acute, as well as in chronic and subchronic intoxication may lead to oxidative stress causing the enhancement of lipid peroxidation and changing the activities of antioxidative enzymes. Paraoxonase PON1 is synthesized by the liver. This enz...

This study aimed to model long-term subtoxic human exposure to an organophosphorus pesticide, chlorpyrifos, and to examine the influence of that exposure on the response to intermittent high-dose acute challenges. Adult Long-Evans male rats were maintained at 350 g body weight by limited access to a chlorpyrifos-containing diet to produce an intake of 0, 1, or 5 mg/kg/day chlorpyrifos. During t...

OBJECTIVE The purpose of this study was to investigate the impact of prenatal exposure to chlorpyrifos on 3-year neurodevelopment and behavior in a sample of inner-city minority children. METHODS As part of an ongoing prospective cohort study in an inner-city minority population, neurotoxicant effects of prenatal exposure to chlorpyrifos were evaluated in 254 children through the first 3 year...

Several processes take place within vegetated buffer strips that affect their performance. To better understand these processes, a runoff study was conducted to evaluate vegetated buffer strips performance in reducing atrazine, metolachlor, and chlorpyrifos transport as affected by the drainage area to buffer strip area ratio. The simulated runoff water mixed with pesticide–treated soil was dis...

We examined the effects of 3 active ingredients in baits containing glucose on a behaviorally resistant (glucose-averse, T-164) strain of Blattella germanica L. Baits with glucose and hydramethylnon or chlorpyrifos killed few T-164 individuals; however, ÞpronilÐglucose baits killed 60% of the cockroaches by day 14. Although ingestion levels were low, ÞpronilÐglucose baits were consumed more tha...

Binding of the endocannabinoid anandamide or of Delta(9)-tetrahydrocannabinol to the agonist site of the cannabinoid receptor (CB1) is commonly assayed with [3H]CP 55,940. Potent long-chain alkylfluorophosphonate inhibitors of agonist binding suggest an additional, important and closely-coupled nucleophilic site, possibly undergoing phosphorylation. We find that the CB1 receptor is also sensiti...