The ruthenium complex cis-(dichloro)tetrammineruthenium(III) chloride induces apoptosis and damages DNA in murine sarcoma 180 cells.

Ruthenium(III) complexes are increasingly attracting the interest of researchers due to their promising pharmacological properties. Recently, we reported that the cis-(dichloro)tetrammineruthenium(III) chloride compound has cytotoxic effects on murine sarcoma 180 (S-180) cells. In an effort to understand the mechanism responsible for their cytotoxicity, study we investigated the genotoxicity, cell cycle distribution and induction of apoptosis caused by cis- (dichloro)tetrammineruthenium(III) chloride in S-180 tumour cells. cis-(dichloro)tetrammineruthenium(III) chloride treatment induced signifi cant DNA damage in S-180 cells, as detected by the alkaline comet assay. In the cell cycle analysis, cis-(dichloro)tetrammineruthenium(III) chloride caused an increase in the number of cells in G1 phase, accompanied by a decrease in the S and G2 phases after 24 h of treatment. In contrast, the cell cycle distribution of S-180 cells treated with cis-(dichloro)tetrammineruthenium(III) chloride for 48 h showed a concentration-dependent increase in the sub-G1 phase (indicating apoptosis), with a corresponding decrease in cells in the G1, S and G2 phases. In addition, cis-(dichloro)tetrammineruthenium(III) chloride treatment induced apoptosis in a time-dependent manner, as observed by the increased numbers of annexin V-positive cells. Taken together, these fi ndings strongly demonstrate that DNA damage, cell cycle changes and apoptosis may correlate with the cytotoxic effects of cis-(dichloro)tetrammineruthenium( III) chloride on S-180 cells.

Análise espectroscópica do conteúdo de monômero residual liberado pelas resinas acrílicas termopolimerizáveis / Spectroscopic analysis of the content of residual monomer released by the heat polymerized acrylic resins

As técnicas espectroscópicas ultravioleta (UV) e infravermelho (IR) foram utilizadas neste trabalho com o objetivo de analisar o conteúdo de monômero residual em duas resinas acrílicas termopolomerizáveis de uso odontológico, com relaçäo a variaçäo nos ciclos de polimerizaçäo e nos tempos de dosagem do monômero. Os resultados obtidos mostraram que as quantidade de monômero residual liberadas pelas resinas estudadas foram baixas e dependentes do tempo e temperatura de polimerizaçäo. A liberaçäo do monômero também foi maior nas primeiras horas, diminuindo a medida que decorria o tempo de imersão em água