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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Poisoning From Oral Ingestion of Carbofuran (Furadan 4F), a Cholinesterase-Inhibiting Carbamate Insecticide, and Its Effects on Cholinesterase Activity in Various Biological Fluids

Ferslew, K. E., Hagardorn, A. N., McCormick, W. F. 01 January 1992 (has links)
A case is presented of a fatal ingestion of Furadan (carbofuran), a cholinesterase-inhibiting carbamate insecticide. A 26-year-old white male was found dead with a partially filled 1-gal (3.8-L) container of Furadan 4F insecticide-nematocide (44.9% carbofuran). The individual had ingested approximately 345 mL of the mixture. Analysis of cholinesterase activity in various biological fluids was performed spectrophotometrically using propionylthiocholine and 5,5'-dithiobis-2-nitrobenzoic acid [Sigma Diagnostics, cholinesterase procedure No. 422 (PTC)] which was measured at 405 nm and 30°C in a Gilford Stasar III Spectrophotometer. The cholinesterase activities were as follows: plasma, 245 units (U)/L (93% inhibition/7% normal activity); serum, 208 U/L (95.3% inhibition/4.7% normal activity); whole blood, 297 U/L (92.8% inhibition/7.2% normal activity); erythrocytes, 58 U/L (99% inhibition/1% normal activity); vitreous humor, 7 U/L; and bile, 148 U/L. Carbofuran was detected in the blood and gastric contents by thin-layer chromatography. No alcohol or other drugs were detected in the blood, urine, or gastric contents. Ingestion of the carbofuran produced acute visceral congestion and pulmonary edema. Death was caused by anoxia due to respiratory paralysis produced by cholinesterase inhibition from Furadan (carbofuran) ingestion.
2

Seleção de fungos de decomposição branca para a redução da toxicidade do acefato / White Fungi for Reduction of Acephate Toxicity

JARDIM, Valéria de Lima 23 August 2010 (has links)
Made available in DSpace on 2014-07-29T15:01:42Z (GMT). No. of bitstreams: 1 dissertacao valeria de Lima Jardim 2010.pdf: 266263 bytes, checksum: 0a24700be4dcac6e853b3f6e041e4a78 (MD5) Previous issue date: 2010-08-23 / Brazil is one of the top pesticides using countries in the world, being the State of Goiás a potential contributor due to its large production of industrial tomatoes. Among the most widely used pesticides is the organophosphate Acephate with toxicological characteristics capable of infecting both living beings and the environment. There are several seeking solution studies to remediate xenobiotic compounds, being microorganisms an important biotechnological tool against them. The aim of this study was to select rot-white fungal that can produce oxidative enzymes under certain conditions, in the presence of Acephate, evaluating their effectiveness in reducing its toxicity. Thus, the study was divided into three parts: testing on solid medium under different nutritional conditions, tests in liquid culture medium under two different conditions (shaking and static) and development of analytical methodology to evaluate the decrease of Acephate toxicity. We defined two levels of Acephate, 10 and 50%, which were treated by the following species: Trametes versicolor, Trametes villosa, Pycnoporus sanguineus, Phanerochaete chrysosporium and Lentinus edodes. In solid medium all species showed mycelial growth and satisfying development in the presence of Acephate under standard nutritional conditions. The concentration of 50% Acephate caused limitation to Trametes villosa in solid and liquid medium cultivation. The opposite occurred to Pycnoporus sanguineus, which had good results in the development and production of enzymes in the presence of Acephate. Lignin Peroxidase in Phanerochaete chrysosporium was present with a 15.77U.mL-1 only in Acephate 50%, suggesting that the pesticide may induce its enzyme complex. The enzyme Laccase excelled in Pycnoporus sanguineus in the two culture conditions, being the largest peak 45.95 U.mL-1 in 50% Acephate in shaking. However, the best value for the production of Laccase from Trametes villosa was in the static condition: 73.55 U.mL-1 in Acephate 10%. The toxicity tests applied, NRU and Cholinesterase Enzyme Inhibition, proved that in these conditions there was no formation of the metabolite Methamidophos. The toxicological methodology developed to assess the toxicity reduction in the treated supernatant was efficient and promising to monitor and investigate environmental contamination. The samples treated by fungi showed 100% increase of Cholinesterase compared to the control group (no treatment) for T. villosa and 91.7% for P. sanguineus. These results showed that the enzyme complex of the fungi studied is capable to reduce Acephate toxicity, proving that well managed rot-white fungal can bring environmental benefits of mitigation. / O Brasil está entre os principais países consumidores de agrotóxicos, sendo o Estado de Goiás um colaborador em potencial devido à grande produção de tomate industrial. Dentre os agrotóxicos mais utilizados, destaca-se o organofosforado Acefato com características toxicológicas capazes de contaminar os seres vivos e o meio ambiente. Várias são as pesquisas que buscam soluções na remediação de compostos xenobióticos, sendo os microrganismos importantes ferramentas biotecnológicas para esse fim. O objetivo deste estudo foi selecionar fungos de decomposição branca capazes de produzir enzimas oxidativas em determinadas condições, na presença de Acefato, avaliando a sua eficiência em reduzir a sua toxicidade. Para tanto o estudo foi dividido em três partes: ensaios em meio de cultura sólido em diferentes condições nutricionais, ensaios em meio de cultura líquido sob duas condições distintas (agitação e estática) e desenvolvimento de metodologia analítica de avaliação da redução de toxicidade do Acefato. Foram definidas duas concentrações de Acefato, 10 e 50%, as quais foram submetidas ao tratamento pelas seguintes espécies: Trametes versicolor, Trametes villosa, Pycnoporus sanguineus, Phanerochaete chrysosporium e Lentinus edodes. Em meio de cultura sólido, todas as espécies apresentaram crescimento micelial e desenvolvimento satisfatórios na presença de Acefato em condição nutricional padrão. A concentração de 50% de Acefato causou limitação para Trametes villosa no cultivo em meio de cultura sólido e líquido. O oposto ocorreu com Pycnoporus sanguineus, que teve bons resultados de desenvolvimento e produção enzimática na presença de Acefato. Lignina Peroxidase esteve presente em Phanerochaete chrysosporium com 15,77U.mL-1 somente em Acefato 50%, sugerindo que o agrotóxico possa induzir seu complexo enzimático. A enzima Lacase se destacou em Pycnoporus sanguineus nas duas condições de cultivo, sendo o maior pico de 45,95 U.mL-1 na presença de 50% de Acefato em agitação. No entanto, o melhor valor para produção de Lacase foi de Trametes villosa na condição estática: 73,55 U.mL-1 em Acefato 10%. Nos testes de toxicidade aplicados, NRU e Inibição da Enzima Colinesterase, comprovou-se que não houve formação do metabólito Metamidofós, nestas condições. A metodologia toxicológica desenvolvida para avaliar a redução de toxicidade do sobrenadante tratado mostrou-se eficaz e promissora no monitoramento e investigação de contaminação ambiental. As amostras tratadas por fungos apresentaram 100% de aumento de Colinesterase em comparação com o Grupo Controle (sem tratamento) para T. villosa e 91,7% para P. sanguineus. Esses resultados mostram que o complexo enzimático dos fungos estudados é capaz de reduzir a toxicidade do Acefato, comprovando que os fungos de decomposição branca, se bem conduzidos, podem trazer benefícios ambientais de mitigação.

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