RESUMEN
This study is among the first employing anatomical partial hepatectomy and exposure of the remnant organ to lasers before closure for comparison of biological changes with those of exposed sham-operated groups and the respective controls. Adult male rats were partially hepatectomized leading to removal of two-thirds of the organ and the lateral lobe exposed to Argon (514 nm, 270 mW-3.0 W for up to 120 s; tunable dye, 630 nm, 200 and 500 mW for up to 240 s) and Nd:YAG (1064 nm; 3-8 W, 60-180 s) lasers. Sham-operated rats were treated similarly and with several, 1 or 2 additional sites in the quadrate lobes were irradiated. Possibly, liver damage and penetrability were somewhat greater for the intact rats treated with the Nd:YAG laser and which also displayed liver profile changes over the controls in contrast to the partially hepatectomized. In general, the extent of liver regeneration over a period of 10 days post-operative was not affected by the laser treatment. The mixed function oxidase system reflected small decrements in aminopyrine demethylase and in benzo[a]pyrene hydroxylase for adjacent lesion-free microsomes from the partially hepatectomized and intact groups exposed to Nd:YAD laser (5.0 W, 120 s), respectively.
Asunto(s)
Rayos Láser/efectos adversos , Regeneración Hepática , Hígado/efectos de la radiación , Animales , Hepatectomía , Lípidos/análisis , Hígado/química , Hígado/patología , Masculino , Microsomas Hepáticos/enzimología , Microsomas Hepáticos/efectos de la radiación , Tamaño de los Órganos/efectos de la radiación , Ratas , Ratas Endogámicas , Rayos Ultravioleta/efectos adversosRESUMEN
Photosensitization in a light scattering matrix was investigated with a tissue model consisting of polystyrene microsphere scattering particles, in the presence of a Photofrin II as a photosensitizing agent, and subtilisin Carlsberg as an enzyme target. The photodynamic rate constant for irradiation at 435 nm, 545 nm, and red light was measured at different microsphere concentrations. The reaction rate was almost independent of the microspheres, ruling out a significant effect of light scattering on the integrated photosensitization efficiency. Modeling with the one-dimensional diffusion approximation showed that increasing scatterer concentrations led to lower transmission and higher diffuse reflection, such that the fractional absorption was almost constant. The quantum efficiency of enzyme inactivation in the light-scattering systems was 0.0014 +/- 0.0003. In terms of incident dose, red and green light had approximately the same effectiveness and blue light was two-fold more efficient.