ABSTRACT
A study was undertaken to examine the uptake of the organophosphate insecticide pyridaphenthion in the chlorophyta Chlorella saccharophila. Algae cultures were exposed to the initial nominal concentration 10.0 mg l(-1) pyridaphention during seven days. The insecticide bioconcentrates in the biomass to the highest level of 441.5 +/- 25.9 mg kg(-1) on the fifth day of exposure and was followed by a decrease to 76.6 +/- 5.1 mg kg(-1) on the seventh day. A model was constructed to describe the dynamic process, which estimated a bioconcentration factor (BCF) equal to 28. The study demonstrates the potential of accumulation of pyridaphenthion in aquatic organisms and helps to expand the pyridaphenthion toxicity database. The replacement of fenitrothion by pyridaphenthion concerning their use in rice flooded cultures is discussed.
Subject(s)
Biomass , Chlorella/metabolism , Environmental Monitoring/methods , Insecticides/pharmacokinetics , Organothiophosphorus Compounds/pharmacokinetics , Absorption , Insecticides/metabolism , Insecticides/toxicity , Models, Biological , Organothiophosphorus Compounds/metabolism , Organothiophosphorus Compounds/toxicity , PharmacokineticsABSTRACT
Avaliar os resultados do tratamento cirúrgico mediante ligadura de veias perfurantes suficientes em pacientes com sintomas clínicos de insuficiência venosa crônica dos membros inferiores. Trata-se de um estudo prospectivo iniciado em março de 1996 e finalizado em junho de 1997, abrangendo um grupo de 15 pacientes selecionados que foram que foram submetidos a cirurgia de veias perfurantes suficientes dos membros inferiores, sob anestesia local e em regime ambulatorial, após serem estudados com Doppler bidirecional, eco-Doppler e flebografia...