RESUMO
The mitochondria toxicity assay (MTT assay) is an established method for monitoring cell viability based on mitochondrial activity. Here the MTT assay is proposed for the in situ quantification of the living cell density of microencapsulated Jurkat cells. Three systems were used to encapsulate the cells, namely a membrane consisting of an interpenetrating polyelectrolyte network of sodium cellulose sulphate/poly(diallyldimethylammonium chloride) (NaCS/PDADMAC), a calcium alginate hydrogel covered with poly(L-lysine) (Ca-alg-PLL), and a novel calcium alginate-poly(ethylene glycol) hybrid material (Ca-alg-PEG). MTT results were correlated to data obtained by the trypan blue exclusion assay after release of the cells from the NaCS/PDADMAC and Ca-alg-PLL capsules, while a resazurin-based assay was used for comparison in case of the Ca-alg-PEG material. Analysis by MTT assay allows quick and reliable determination of viable cell densities of encapsulated cells independent of the capsule material. The assay is highly reproducible with inter-assay relative standard deviations below 10%.
Assuntos
Alginatos/farmacologia , Celulose/análogos & derivados , Mitocôndrias/efeitos dos fármacos , Polietilenoglicóis/farmacologia , Polietilenos/farmacologia , Compostos de Amônio Quaternário/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Celulose/farmacologia , Ácido Glucurônico/farmacologia , Ácidos Hexurônicos/farmacologia , Humanos , Células Jurkat , Relação Estrutura-AtividadeRESUMO
A total of 194 gallbladder biles from various ethnic groups were analyzed for their composition. The solubility of cholesterol in bile was determined mainly by its relative amounts of phospholipid and bile salt present. Bile from patients with gallstones was usually supersaturated with cholesterol above the boundary of the metastable state. Biles from normal white subjects of Finland, New Zealand, and the United States were already in the metastable state of supersaturation with cholesterol. The Masai of East Africa and black subjects of the Unites States had a bile level below the limit of maximum cholesterol solubility. This study indicates that the difference in the prevalence of cholesterol cholelithiasis in various ethnic groups was related to the difference in their bile compontified factors.
