RESUMO
An improved method has been developed for the quantitative determination of cyanide in human blood by headspace gas chromatography with electron-capture detection. In this novel method, cyanide was detected after conversion of hydrogen cyanide into cyanogen chloride by a reaction with chloramine T. The advantage of this new procedure lies in the fact that hydrogen cyanide formation and chlorination are carried out in a single step and in the same reaction medium. This method is simple, rapid, and specific for cyanide and does not suffer from any interference by cyanate and thiocyanate. The detection limit is 5 micrograms/L. The detection response is linear from 5 to 1000 micrograms/L, and the within-run coefficient of variation in this range is 8% or less. This method is particularly useful for routine diagnostic analysis of biological samples in case of acute cyanide poisoning.
Assuntos
Cromatografia Gasosa/instrumentação , Cromatografia Gasosa/métodos , Cianetos/sangue , HumanosAssuntos
Fígado/efeitos dos fármacos , Mutagênicos/toxicidade , Nitrosaminas/toxicidade , Ozônio/química , Animais , Carcinógenos/química , Carcinógenos/toxicidade , Cromatografia Gasosa , Interações Medicamentosas , Testes de Mutagenicidade , Mutagênicos/química , Nitrosaminas/química , Ratos , Ratos Sprague-Dawley , Poluentes Químicos da Água/toxicidadeRESUMO
The H5-6 cultured rat hepatoma cell line was used to investigate the post-translational maturation of gamma-glutamyltransferase (GGT) and the effects of acute ethanol administration on the expression and glycosylation of this membrane-bound glycoprotein. We found that the two subunits of H5-6 GGT with molecular masses of 55 and 33 kDa were derived from a single glycosylated precursor of 80 kDa. In addition, signals of high molecular mass (more than 90 kDa) were detected. In vitro deglycosylation experiments indicated that N-linked sugars represented about 25% of the molecular weight of the H5-6 enzyme. By use of serial lectin affinity technique, we showed that N-linked sugar chains were mainly of the biantennary complex and hybrid-type, without fucose linkage to the innermost N-acetyl-glucosamine. Ethanol treatment did not seem to affect the expression of GGT and the sialic acid content of the enzyme, but altered its oligosaccharide chain composition both quantitatively and qualitatively.
