Phototoxicity of two positive-charged diaryl porphyrins in multicellular tumor spheroids.

Photodynamic therapy (PDT) is a clinically approved cancer treatment in which reactive oxygen species are formed only when three harmless components, a photosensitizer (PS), light and molecular oxygen, are present at the same time, leading to cell death. Most of the PSs were tested on monolayer cells, but differences between 2D cells and solid tumors significantly limit the value of in vitro PDT studies, whereas the use of 3D spheroid might be more suitable for drug development and preclinical drug testing for PDT. In a previous work we have shown that two positive-charged diaryl porphyrins (2 and 4) were more potent than the corresponding neutral molecules (1 and 3) on a panel of 2D-cultured cancer cell lines.

Normal range of calcitonin in children measured by a chemiluminescent two-site immunometric assay.

Calcitonin (CT) assay is of considerable importance in the routine evaluation of thyroid nodules and for screening and follow-up of patients with medullary thyroid carcinoma and their relatives. Aim of this study was to assess the reference ranges for CT levels in healthy children and to evaluate possible differences in CT levels between sex and age. Serum CT levels were measured by a commercially available two-site chemiluminescence immunometric assay (sensitivity = 0.