Advances in photodynamic therapy for the treatment of hilar biliary tract cancer.

The prognosis of patients with nonresectable hilar biliary tract cancer (hBTC) is poor. Responsiveness to chemotherapy or radiochemotherapy is moderate at best, and patients are at a high risk of dying early from complications of local tumor infiltration (e.g., cholestasis, septic cholangitis, empyema or liver failure) rather than systemic disease. Therefore, palliative local therapy for the prevention of tumor complications plays a central role and still yields the longest survival times. Photodynamic therapy (PDT) is a local-ablative, tumor tissue-specific treatment currently representing the standard of care for nonresectable hBTC. Throughout the literature, PDT plus biliary drainage achieves median survival times in the range of 9-21 months (average 14-16 months), compared with approximately 6 months for drainage only. This article summarizes the recent advances in preclinical and clinical experience of PDT for hBTC, including experimental in vitro and in vivo studies, clinical studies and an overview of the ongoing clinical trials.

Antibacterial photodynamic therapy using water-soluble formulations of hypericin or mTHPC is effective in inactivation of Staphylococcus aureus.

Antibacterial photodynamic treatment (APDT) might prove valuable as an alternative to the application of chemoantibiotics for the treatment of staphylococcal infections. The rapid uptake of the photosensitizing agent into bacteria allows for selective killing of microorganisms whilst sparing the eukaryotic host tissue, but also requires removal of excessive dye after the incubation period. We tested water-soluble formulations of hypericin (PVP-hypericin) and m-tetrahydroxyphenylchlorin (Fospeg), which could be applied as aqueous sprays and removed easily by flushing with buffers, for their efficiency in killing Staphylococcus aureus. For both sensitizers, 100 nM of the photoactive substance incubated for 5 min and illuminated for 30 min at 75 mW cm(-2) lead to a 4-5 log unit reduction in bacterial count. At a concentration of 300 nM (incubation time 5 min), 30 min illumination at 25 mW cm(-2) is more effective than 10 min illumination at 75 mW cm(-2) (both resulting in the same fluence). We suggest both substances as promising candidates for treatment of staphylococcal infections in wounds with APDT.

Antioxidant systems of brown trout (Salmo trutta f. fario) semen.

The present study characterizes the antioxidant systems of brown trout, Salmo trutta, semen as supplementation of semen dilution media with antioxidants can be beneficial to improve techniques for semen storage and cryopreservation. Antioxidants and oxidant defensive enzymes of spermatozoa and seminal plasma were analyzed. To determine whether antioxidants and oxidant defensive enzymes have an effect on sperm functionality, in vitro experiments were performed. Selected antioxidants and oxidant defensive enzymes were added to sperm motility-inhibiting saline solution and their effects on sperm viability (motility when activated, membrane integrity, and lipid peroxidation) were measured. In seminal plasma and spermatozoa the enzymes catalase, glutathione reductase, methionine sulfoxide reductase, peroxidase, and superoxide dismutase and the metabolites ascorbic acid, glutathione, methionine, tocopherol, and uric acid were detected. Of the enzymes superoxide dismutase had the highest activity, of the metabolites uric acid occurred in highest concentrations. During in vitro incubation uric acid and catalase increased the sperm motility, sperm membrane integrity, and decreased the sperm lipid peroxidation in comparison to the control. However, catalase was effective only at an activity much higher than that occurring in seminal plasma. Reduced methionine increased the sperm motility and sperm membrane integrity and oxidized methionine the motility. However, neither reduced nor oxidized methionine decreased the sperm membrane lipid peroxidation. It is concluded, that uric acid is the main antioxidant of brown trout semen.