RESUMEN
The effect of 0.1 and 0.5% L- and D-monomers on cultured fibroblasts was determined by studying the proliferation, morphology and cellular activity. The addition of 0.5% monomer reduced the metabolic activity of the cells by about 40%, but the proliferation and morphology were only negatively affected for the 0.5% monomer in combination with an increased osmolarity of the medium. The addition of sucrose, however, resulted in an increased proliferation and acid phosphatase activity, as well as an altered morphology. Therefore, it can be concluded from this study that the osmolarity, as well as the nature and concentration of the added material, can exert an influence on proliferation, morphology and/or cellular activity.
Asunto(s)
Ensayo de Materiales , Poliésteres/toxicidad , División Celular/efectos de los fármacos , Células Cultivadas , Medios de Cultivo , Fibroblastos/efectos de los fármacos , Humanos , Concentración Osmolar , Poliésteres/metabolismo , EstereoisomerismoRESUMEN
Four types of polylactide particulates, P-L-LA 100, 250, 550 KD and a P-DL-LA 400 KD were injected into the peritoneal cavity of mice. The inflammatory reaction showed an increase in cell number (mainly neutrophilic granulocytes) up to 48 h after which the cell numbers decreased below the control (phosphate-buffered saline). All four polylactide particulates aggregated and intermingled with inflammatory cells. The aggregates remained throughout the investigation period of 6 months. Quantitative measurements showed that standardization of the particle form and size is essential. From this study and other experiments in which calcium phosphates and asbestos were injected intraperitoneally, it is concluded that the inflammatory response observed in the peritoneal cavity is related to the type of material injected and probably to form and size of the individual particles, but not to molecular weight.
Asunto(s)
Inflamación/inducido químicamente , Macrófagos/ultraestructura , Neutrófilos/ultraestructura , Poliésteres/toxicidad , Animales , Inflamación/patología , Inyecciones Intraperitoneales , Ratones , Microscopía Electrónica , Microscopía Electrónica de Rastreo , Peso Molecular , Tamaño de la Partícula , Cavidad Peritoneal , Poliésteres/administración & dosificaciónRESUMEN
Immunohistochemical staining techniques were used to investigate the localization of the 3-methylcholanthrene inducible isoenzymes (P450 IA1 and IA2) in the rat liver. The rats were induced with different doses of 3-methylcholanthrene, ranging from 2.5 to 25 mg/kg body weight. A heterogeneous induction pattern was observed with induction doses of 2.5; 5; 7.5 and 10 mg/kg body weight with the highest concentration of the isoenzymes around the central vein. With a dose of 25 mg/kg body weight, a homogeneous pattern was found. Induction with a dose of 15 mg/kg body weight resulted in an intermediate situation.