A note on the analysis of ligand binding by the 'double-logarithmic' plot.

The double-logarithmic plot has been employed for the fluorometric analysis of ligand binding. This analysis is valid only for 1:1 binding of a non-aggregating ligand and if the plot is based on the free, and not the total, ligand concentration.

Photosensitization of red blood cell hemolysis by lutetium texaphyrin.

Lutetium (III) texaphyrin photosensitizes postirradiation or "delayed" photohemolysis (DPH) of human and bovine red blood cells at 730 nm by a Type-2 pathway mediated by singlet molecular oxygen. The DPH rate increases with increasing incubation temperature and with the second power of the incident fluence. The experimental DPH curves are in good agreement with a multi-hit kinetics model based on target theory.

PDT light dosimetry revisited.

A versatile PDT light dosimetry model is described incorporating the effects of drug photobleaching, drug elimination, and normal tissue damage. The dependence of the necrosis depth (dn) on the incident light dose for the four major modes of PDT light delivery has the form: dn = delta loge(DG), where delta is the optical penetration depth of the tumor tissue, D is the ratio of the incident light dose to the energy fluence at the necrosis threshold, and G is a function of the tissue optical constants. Light dosimetry graphs were calculated for Photofrin at standard conditions.

Sensitization of photohemolysis by hypericin and Photofrin.

Sensitization of post-irradiation (delayed) photohemolysis (DPH) and "during irradiation" (continuous) photohemolysis (CPH) were investigated for sodium hypericin and Photofrin. The photohemolysis rate and relative steepness of the photohemolysis curves were measured for a range of sensitizer concentrations and DPH irradiation times. The data are analyzed by a multihit model based on the assumption that photohemolysis requires thermal activation of light-activated damage.

Cytotoxic effect of photodynamic therapy with Photofrin II on intimal hyperplasia.

This study evaluates the effect of photodynamic therapy using Photofrin II on prevention and treatment of intimal hyperplasia in a rabbit model of common carotid artery balloon injury. An established model was used. One week after injury (inhibition arm) or 6 weeks after injury (treatment arm), each common carotid artery was exposed to continuous external laser irradiation 48 hours after a 5 mg/kg intravenous dose of Photofrin II (fluency = 7.