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Lancet (London, England) May 1978
Topics: Agricultural Workers' Diseases; Humans; Paraquat; Skin
PubMed: 77397
DOI: 10.1016/s0140-6736(78)90945-5 -
Brain Research Mar 2009Environmental factors have long been thought to have a role in the etiology of idiopathic Parkinson's disease (PD). Since the discovery of the selective neurotoxicity of...
Environmental factors have long been thought to have a role in the etiology of idiopathic Parkinson's disease (PD). Since the discovery of the selective neurotoxicity of MPTP to dopamine cells, suspicion has focused on paraquat, a common herbicide with chemical structure similar to 1-methyl-4-phenylpyridinium (MPP+), the MPTP metabolite responsible for its neurotoxicity. Although in vitro evidence for paraquat neurotoxicity to dopamine cells is well established, its in vivo effects have been ambiguous because paraquat is di-cationic in plasma, which raises questions about its ability to cross the blood brain barrier. This study assessed the brain uptake of [(11)C]-paraquat in adult male rhesus macaques using quantitative PET imaging. Results showed minimal uptake of [(11)C]-paraquat in the macaque brain. The highest concentrations of paraquat were seen in the pineal gland and the lateral ventricles. Global brain concentrations including those in known dopamine areas were consistent with the blood volume in those structures. This acute exposure study found that paraquat is excluded from the brain by the blood brain barrier and thus does not readily support the causative role of paraquat exposure in idiopathic Parkinson's disease.
Topics: Animals; Blood-Brain Barrier; Brain; Carbon Radioisotopes; Image Processing, Computer-Assisted; Macaca mulatta; Magnetic Resonance Imaging; Male; Neurotoxins; Paraquat; Positron-Emission Tomography
PubMed: 19135428
DOI: 10.1016/j.brainres.2008.12.033 -
The Journal of Burn Care &... 2001Paraquat is a bipyridyl compound widely used as a contact herbicide. Since its introduction in 1962, hundreds of deaths have occurred, usually after suicidal or...
Paraquat is a bipyridyl compound widely used as a contact herbicide. Since its introduction in 1962, hundreds of deaths have occurred, usually after suicidal or accidental ingestion. Death after dermal absorption of paraquat is uncommon, but has occurred after either contact with undiluted paraquat, disruption of skin integrity, or prolonged exposure. It is the purpose of this case report to describe a patient who had fatal dermal paraquat absorption after a crop-dusting accident in which he sustained 37% TBSA burns. After 9.5 hours of cutaneous exposure, a paraquat level of 0.169 mg/ml was obtained at 20 hours, the standard lethal dose at 16 hours being 0.16 mg/ml. In light of the apparently irreversible pathophysiology of paraquat poisoning with plasma levels as low as 3 mg/L, prevention and early intervention are the best treatments. Our patient may have survived an otherwise routine thermal injury had his wounds been aggressively irrigated in the field.
Topics: Accidents, Occupational; Agriculture; Burns; Herbicides; Humans; Male; Middle Aged; Paraquat; Skin Absorption
PubMed: 11570536
DOI: 10.1097/00004630-200109000-00011 -
Postgraduate Medical Journal Nov 1989We describe a fatal case of paraquat poisoning as a result of per vaginal contact with the herbicide. Death occurred 18 days later from hepatic, renal and respiratory...
We describe a fatal case of paraquat poisoning as a result of per vaginal contact with the herbicide. Death occurred 18 days later from hepatic, renal and respiratory failure.
Topics: Administration, Intravaginal; Adult; Female; Humans; Paraquat; Tampons, Surgical
PubMed: 2616419
DOI: 10.1136/pgmj.65.769.835 -
Journal of Chromatographic Science Sep 1978Methods for the determination of paraquat are reviewed. Procedures are described in detail for the determination of paraquat in diverse materials such as food stuffs,...
Methods for the determination of paraquat are reviewed. Procedures are described in detail for the determination of paraquat in diverse materials such as food stuffs, body fluids, and water. The recommended procedures include visual spot test, spectrophotometric, gas chromatographic, and high performance liquid chromatographic techniques.
Topics: Chromatography, Gas; Chromatography, High Pressure Liquid; Colorimetry; Food Analysis; Humans; Paraquat; Water Pollutants, Chemical
PubMed: 730819
DOI: 10.1093/chromsci/16.9.390 -
Analytical Biochemistry Dec 2011Paraquat (PQ) is widely used in the laboratory to induce in vivo oxidative stress, particularly in the fruit fly, Drosophila melanogaster. PQ administration to the fly...
Paraquat (PQ) is widely used in the laboratory to induce in vivo oxidative stress, particularly in the fruit fly, Drosophila melanogaster. PQ administration to the fly traditionally involves feeding in a 1% sucrose solution; however, a diet high in sucrose can itself be stressful. We examined a novel method of PQ administration: incorporation into the fly's standard cornmeal-sucrose-yeast diet. This method successfully delivers PQ to the fly at concentrations similar to those of the traditional method but with fewer possibly confounding complications.
Topics: Animals; Biochemistry; Chromatography, High Pressure Liquid; Drosophila melanogaster; Oxidative Stress; Paraquat
PubMed: 21910964
DOI: 10.1016/j.ab.2011.08.023 -
Human Toxicology Jan 1987Paraquat can be removed by haemodialysis and haemoperfusion but, although clearance values are high, the quantities recovered are insignificant. Prevention of death is...
Paraquat can be removed by haemodialysis and haemoperfusion but, although clearance values are high, the quantities recovered are insignificant. Prevention of death is most unlikely except perhaps in patients with plasma paraquat concentrations very close to the previously proposed line separating concentrations in fatal cases and survivors at different time intervals. Even if delays incurred in measuring plasma paraquat concentrations and in setting up haemodialysis or haemoperfusion could be reduced to a minimum, elimination by these procedures would achieve little because paraquat disappears rapidly from the plasma in the first few hours after ingestion as it is taken up by the tissues and excreted into the urine. Further studies on patients at borderline risk are required and the value of 'continuous' haemoperfusion requires further assessment.
Topics: Adult; Female; Hemoperfusion; Humans; Male; Paraquat; Renal Dialysis
PubMed: 3817831
DOI: 10.1177/096032718700600111 -
Journal of Pharmaceutical Sciences Aug 1978
Topics: Cannabis; Methods; Paraquat
PubMed: 671232
DOI: 10.1002/jps.2600670803 -
Lancet (London, England) Feb 1975
Topics: Humans; Paraquat
PubMed: 46420
DOI: 10.1016/s0140-6736(75)91178-2 -
Journal of Toxicology. Clinical... 1993Knowledge of the kinetics of an intoxicant is required for designing potential therapies in poisoned patients. In the case of paraquat, elucidating the kinetics has been...
Knowledge of the kinetics of an intoxicant is required for designing potential therapies in poisoned patients. In the case of paraquat, elucidating the kinetics has been made difficult by the paraquat-induced renal failure and the consequent dose- and time-dependent elimination of the herbicide. In the current study, we have modelled the plasma and urinary concentrations of paraquat in dogs given a toxic dose, the elimination of which was nonlinear. This enabled us, in turn, to simulate the apparent concentrations of paraquat in the deep tissue compartment, part of which is constituted by the major target organ for paraquat toxicity, the lung. Finally, we defined conditions, if any, under which charcoal hemoperfusion could reduce exposure of the deep compartment to paraquat by > or = 25%. We found that the plasma concentrations of paraquat could be described by a two compartment model with non-linear elimination from the central compartment. Use of a three compartment model did not improve the fit over that for a two compartment. The volume of distribution of paraquat at steady state approximated that of total body water. Simulated hemoperfusion performed for eight or eighty hours did not reduce exposure of the deep compartment to paraquat by > or = 25%, unless begun at times < or = two hours of the infusion commencing. This is consistent with our experimental data in the dog. The lack of efficacy of hemoperfusion is due to the rapid renal elimination of most of the absorbed dose of paraquat over the first 12 hours after its administration, and the later limitation of the rate of removal of paraquat from the body by the slow efflux rate from the deep to central compartment.
Topics: Animals; Dogs; Female; Hemoperfusion; Infusions, Intravenous; Male; Metabolic Clearance Rate; Models, Biological; Paraquat
PubMed: 8492337
DOI: 10.3109/15563659309000391