Search results for "Parathion"
showing 10 items of 20 documents
Biomonitoring exposure assessment to contemporary pesticides in a school children population of Spain
2013
The exposure to pesticides amongst school-aged children (6-11 years old) was assessed in this study. One hundred twenty-five volunteer children were selected from two public schools located in an agricultural and in an urban area of Valencia Region, Spain. Twenty pesticide metabolites were analyzed in children's urine as biomarkers of exposure to organophosphate (OP) insecticides, synthetic pyrethroid insecticides, and herbicides. These data were combined with a survey to evaluate the main predictors of pesticide exposure in the children's population. A total of 15 metabolites were present in the urine samples with detection frequencies (DF) ranging from 5% to 86%. The most frequently detec…
Pancuronium improves the neuromuscular transmission defect of human organophosphate intoxication.
1990
Two patients with acute severe organophosphate intoxication showed (1) single evoked compound muscle action potentials (CMAP) with repetitive discharges and (2) prominent decremental responses of CMAP with 20 and 50 Hz supramaximal nerve stimulation. Following the intravenous injection of single small doses of pancuronium, marked improvement in these abnormalities occurred and persisted for several hours. We postulate that the physiologic improvement following low-dose pancuronium results from blockade of acetylcholine receptors, especially those located on the terminal axon responsible for antidromic backfiring.
Concentration dependent effects of commonly used pesticides on activation versus inhibition of the quince (Cydonia Oblonga) polyphenol oxidase
2009
Polyphenol oxidase (PPO) catalyzes the oxidation of o-diphenols to their respective quinones which undergo autopolymerization and form dark pigments. The interaction of PPO with various substrates and effectors remains the focus of intensive investigations due to the enzyme's key role in pigments biosynthesis including animal melanogenesis and fruit/fungi enzymatic browning. In this study, the effect of a range of commonly used pesticides on the enzyme activity has been evaluated using the purified quince (Cydonia oblonga Miller) PPO. The biochemical analysis showed that, in the presence of high pesticide concentrations, the enzyme was competitively inhibited, particularly with benomyl, car…
Isolation Of Organophosphorus Pesticides Bacteria Degraders From Agricultural Sicilian Soils.
2009
Pesticides are generally categorized according to their great or low persistence in the environment. Although new biological, chemical, and management technologies are continually being developed to provide more sustainable production alternatives, it is expected that the use of pesticides will continue to be an essential tool in the integrated pest management. Pesticides are biologically active compounds designed to interfere with metabolic processes. Organophosphorus pesticides (OP) pesticides are less persistent than Organochlorine pesticides (OC), they are not without environmental risks, so this justifies the social concern about their level in different kind of matrices like soil, wat…
An economical hemoperfusion system to determine in vitro clearances of various poisons with different adsorbents.
1980
An economical hemoperfusion system for clearance studies in vitro was developped. It was ascertained, that hemoperfusion using columns which contain 13 g of adsorbent and perfused at a blood flow rate of 1.25 ml/min results in the same relative clearances as when using clinical sized columns containing 300–355 g of the absorbent and run at 100 ml/min. The adsorption kinetics of toxicologically important drugs and pesticides are given as examples. To date 27 substances were tested systematically. The investigation has shown, that no adsorbent is without exception the best one, but the efficacy can vary from substance to substance.
Acute effects of low doses of methyl parathion on human EEG.
2005
Abstract Biological monitoring of workers exposed to organophosphates consists mainly of measuring serum or erythrocyte cholinesterase activity. However, animal experiments and a field study suggest that quantitative analysis of EEG may be more sensitive. In a parallel group design, 25 farmers were investigated, spraying methyl parathion or water for 50 min. EEG was recorded before and after spraying. Serum and erythrocyte cholinesterase activity was compared with intraindividual pre-exposure values. Plasma methyl parathion concentrations ranged up to 12.1 μg/l, methyl paraoxon was not detectable. Based on plasma concentrations, two exposed subgroups were defined. In EEG recorded with close…
Pseudocholinesterase Activity in Organophosphate Poisoning after Storage of Unseparated Blood Samples at Room Temperature for 3 Weeks
2005
Suppressed pseudocholinesterase activity is a well-established laboratory finding in patients with serious organophosphate poisoning (1). Recently, a 48-year-old man with suspected ingestion of methyl parathion died, and the postmortem examination was not indicative. After 3 weeks, an overlooked specimen was discovered that had been collected from the patient ∼1 h after the suspected poisoning. The determination of pseudocholinesterase activity was requested. The blood sample, which showed complete hemolysis, was separated by centrifugation, and the pseudocholinesterase activity was determined. The result of 4.21 kU/L indicated the presence of only minor organophosphate poisoning without su…
Biodiversity of organophosphorus-degrading bacteria isolated from agricultural soils
2009
Organophosphorus (OP) insecticides are used all over the world for crop protection. Although OPs are less persistent than organochlorine pesticides, they still constitute an environmental risk thus increasing the social concern about their levels in soils, surface and ground waters. Biodegradation by microorganisms is primarily responsible for elimination of the OP insecticides released to the environment. In the present study the OP degrading potential of agricultural soils with different agronomic history was investigated. Using enrichment cultures, with parathion or dimethoate as the sole C and energy sources, 47 bacterial isolates were obtained from OPs contaminated and pristine agricul…
Elimination of Parathion by Hemoperfusion in Severe E 605 ForteR Intoxication in Vivo
1978
Severe parathion (P) intoxication results in complete inhibition of cholinesterase activity and toxic accumulation of acetylcholine. Besides these well known biochemical changes, there is evidence of direct toxic effects on the cardio-vascular system which may prove fatal due to an excess of P.
Some observations on the determination of the methyl parathion-parathion ratio in binary mixtures by infrared spectroscopy
1989
Abstract The determination of the methyl parathion/parathion ratio in binary mixtures has been carried out by infrared spectroscopy using a simple and easy model for the treatment of the spectra obtained from sample thin films using sodium chloride windows. The model is based on the use of two bands, one at 974 cm−1, characteristic of parathion, and other at 1348 cm−1, common to both compounds. From the spectra of pure parathion samples and mixtures of known composition of methyl parathion and parathion, two constants have been obtained. These constants relate the absorption of each compound at 1348 cm−1 to the absorption of parathion at 974 cm−1. Eighteen synthetic samples have been analyz…