Effects of herbicide and insecticide interaction on soil entomofauna under maize crop.

The aim of this study was to evaluate the impact of the herbicide mixture nicosulfuron + atrazine, with or without the insecticide chlorpyrifos, onto soil entomofauna under maize crop. The treatments, applied 25 days after maize emergence, were represented by a weeded control without insecticide and herbicide, a weeded control with chlorpyrifos, and mixtures of nicosulfuron + atrazine, with or without chlorpyrifos. Arthropods populations, on the soil surface, as well as inside the soil under maize, were principally represented by mites (Arachnida: Acari), decomposer collembolans (Hexapoda:Parainsecta:Collembola) and predator ants (Hymenoptera:Formicidae). The nicosulfuron + atrazine mixture with chlorpyrifos and the isolated chlorpyrifos reduced the population dynamics of all insect groups on the soil surface compared to the weeded control. In the soil, mite and ant populations were reduced after application of the herbicide mixture with chlorpyrifos and of the isolated chlorpyrifos.

Prospective multicenter study of sulfonylurea ingestion in children.

OBJECTIVE: Sixty-eight percent of pediatric sulfonylurea ingestions reported to poison centers do not result in laboratory or behavioral effects. Consequently, if all exposed children are admitted overnight or for 24 hours for these exposures, it will result in 600 to 700 hospital admissions per year of children who will remain free of symptoms. We prospectively studied exposures reported to 10 regional poison centers to determine if it were possible to differentiate those patients who would have symptoms from those who would remain symptom free. METHODS: We analyzed all sulfonylurea exposures in children < or = 12 years old reported to the participating poison centers. Hypoglycemia was defined as blood glucose (BG) concentration < 60 mg/dl. RESULTS: Hypoglycemia developed in 56 (30%) of 185 exposed patients. Fifty-four of the 56 (96%) hypoglycemic patients had development of hypoglycemia within 8 hours of ingestion. Eighty-seven of the patients were initially managed with oral supplementation only; in 13 cases, treatment advanced to intravenous administration of glucose or glucagon with the onset of hypoglycemia. There was no statistical difference in medical outcome between patients monitored during oral supplementation versus during intravenous infusion of dextrose. Ingestions analyzed by time of day did not predict risk of hypoglycemia. Sufficient data were available for 103 (58%) of the 177 patients who ingested glyburide or glipizide to calculate a toxic dose/weight ratio. Of these 103 patients, 31 of 36 patients who ingested < or = 0.3 mg/kg remained symptom free, whereas 31 of 67 who ingested more than 0.3 mg/kg had BG concentrations < 60 mg/dl (p < 0.005, 95% confidence interval 0.05 to 0.58; sensitivity 86%, specificity 46%). CONCLUSION: A lack of onset of hypoglycemia (BG > 60 mg/dl) in the first 8 hours after ingestion is predictive of a benign outcome in accidental pediatric sulfonylurea ingestion. Clinical observation of children for onset of hypoglycemia during oral feeding alone appears safe. Some children with symptoms of hypoglycemia need to receive intravenous dextrose therapy. Time of day of ingestion is not predictive of risk of hypoglycemia. Finally, at this time it appears inappropriate to use a milligram per kilogram body weight dose as a guide for management decisions.