RESUMO
Release of lactate dehydrogenase (LDH) from the cytoplasmic compartment, trypan blue exclusion and methylthiazole tetrazolium (MTT) colorimetric assays were compared with regard to their sensitivity in detecting damage of human cultured epithelial cells induced by sodium fluoride or puromycin. LDH assay did not detect any difference between controls and cells treated with either of the two drugs. Cell monolayers treated with 0.3% sodium fluoride or 10(-2) M puromycin presented higher percentages of cells that took up the trypan blue dye than controls but monolayers treated with lower drug concentrations did not differ from controls. Viability measured by MTT assay was the most sensitive assay, detecting a dose-dependent impairment of cell function after treatment with the two drugs. Moreover, MTT offered major advantages in speed, simplicity and precise quantitation over the other viability assays.
Assuntos
Técnicas de Cultura de Células/métodos , Sobrevivência Celular , Fígado/citologia , Animais , Chlorocebus aethiops , Corantes , Humanos , L-Lactato Desidrogenase/metabolismo , Mamíferos , Sais de Tetrazólio , Tiazóis , Azul Tripano , Células VeroRESUMO
Release of lactate dehydrogenase (LDH) from the cytoplasmic compartment, trypan blue exclusion and methylthiazole tetrazolium (MTT) colorimetric assays were compared with regard to their sensitivity in detecting damage of human cultured epithelial cells induced by sodium fluoride or puromycin. LDH assay did not detect any difference between controls and cells treated with either of the two drugs. Cell monolayers treated with 0.3
sodium fluoride or 10(-2) M puromycin presented higher percentages of cells that took up the trypan blue dye than controls but monolayers treated with lower drug concentrations did not differ from controls. Viability measured by MTT assay was the most sensitive assay, detecting a dose-dependent impairment of cell function after treatment with the two drugs. Moreover, MTT offered major advantages in speed, simplicity and precise quantitation over the other viability assays.
RESUMO
Pulmonary infection on cystic fibrosis (CF) patients are associated with a limited qualitative number of microorganisms. During the colonization process, Staphylococcus aureus usually precedes Pseudomonas aeruginosa. This latter is at first non-mucoid, being replaced or associated to a mucoid morphotype which is rare in other diseases. In 1980, Pseudomonas cepacia appeared as an important agent in CF pulmonary infections with a mean frequency of about 6.1% isolations in different parts of the world. The primus colonization mainly occurs in the presence of pre-existent tissue lesions and the clinical progress of the disease is variable. In some patients it can be fulminant; in others it can cause a gradual and slow decrease in their pulmonary functions. The concern with this germ isolation is justified by its antibiotic multiple resistance and the possibility of direct transmission from a colonized patient to a non-colonized one. We reported the first case of P. cepacia infection in a CF patient in our area. The microbiological attendance to this patient had been made from 1986 to 1991 and the first positive culture appeared in 1988. The sensitivity profile showed that the primus colonization strain was sensitive to 9 of 17 tested antibiotics, however in the last culture the strain was resistant to all antibiotics. These data corroborate the need for monitoring the bacterial flora on CF patients respiratory system.