Sternoplasty for incomplete sternum separation.
Explore the source record for details and available documents.
Chronic Disease↗
Biomedical subjects
W Rizzoni
Publications and source records attributed to W Rizzoni.
In vitro photodynamic therapy of human lung cancer.
Photodynamic therapy (PDT) using a dihematoporphyrin ether (DHE) sensitizes malignant cells to damage by 630-nm light. This study investigated in vitro PDT sensitivity of human lung cancer cells (A549) and those factors which influence cell survival as determined by the colony formation assay. After incubation for 2, 4, or 6 hr with [DHE] of 2.5, 25, or 50 micrograms/ml, A549 received red light at dose rates of 0.27 or 0.09 mW/cm2 and energies of 0-250 mJ/cm2. Neither 630-nm light alone nor DHE alone affected cell survival. A dose rate of 0.27 mW/cm2 required less energy than 0.09 mW/cm2 for 90% cytotoxicity (180 mJ/cm2 vs 250 mJ/cm2, P less than 0.05). The energy required for 90% cytotoxicity with 25 micrograms/ml [DHE] was dependent on DHE incubation time (2 hr, 90% cytotoxicity not reached; 4 hr, 116 mJ/cm2; 6 hr, 69 mJ/cm2; P less than 0.05). In contrast, cellular [DHE] as measured by fluorescence, plateaued after 2 hr of incubation. Fluorescence microscopy revealed a time-dependent redistribution of fluorescence from the cell membrane to perinuclear and intracytoplasmic organelles. A 99% cytotoxicity required significantly less energy as [DHE] was increased (2.5 micrograms/ml, no cytotoxicity; 25 micrograms/ml, 243 mJ/cm2; 50 micrograms/ml, 111 mJ/cm2; P less than 0.05). Intracellular [DHE] was directly dependent on the incubating media [DHE] (2.5 micrograms/ml, 0.09 +/- 0.01 micrograms/10(6) cells; 25 micrograms/ml, 0.80 +/- 0.07 micrograms/10(6) cells; 50 micrograms/ml, 1.31 +/- 0.11 micrograms/10(6) cells; P less than 0.05). PDT cytotoxicity was inversely proportional to concentration of serum in the DHE media. These data illustrate that lung cancer in vitro is sensitive to PDT and is influenced by dose rate, energy input, and DHE environmental manipulations. These factors may be important in increasing the efficiency of PDT of thoracic malignancies in vivo.
Carcinoma↗
Potentiation of phototherapy cytotoxicity with light scattering media.
Lung cancer cells are susceptible to photodynamic therapy (PDT) using 630 nm light and dihematoporphyrin ether (DHE). A light scattering media, intralipid (IL), was compared to balanced salt solution (PBS) for PDT of A549 human lung cancer cells. Differences in cellular DHE content after IL or PBS exposure were determined. Cells were incubated in 25 micrograms/ml DHE for 2 hr and then incubated in various concentrations of IL or PBS at room temperature for 2.5 to 10.0 min. Significant amounts of DHE were lost from IL-incubated cells compared to cells incubated in PBS. After 5 min in 1% IL, cellular DHE content was 0.32 +/- 0.04 microgram DHE/10(6) cells compared to 0.56 +/- 0.11 microgram DHE/10(6) cells in PBS-incubated cells (P less than 0.05). Despite this, superior PDT cytotoxicity was noted when cells were treated in IL with energy densities greater than or equal to 105 mJ/cm2. At an energy density of 210 mJ/cm2, the survival fraction (SF) of cells treated in 1% IL was 0.004 +/- 0.001 compared to 0.071 +/- 0.022 in PBS-treated cells (P less than 0.05). SF was dependent upon the IL concentration with the greatest cell killing noted with 1% IL. An apparent loss of cellular DHE ("DHE washout") was confirmed by demonstration of a higher SF of cells incubated in IL, rinsed, and subsequently PDT-treated in PBS with 157.5 mJ/cm2 (SF = 0.85 +/- 0.11) compared to cells incubated and treated in PBS (SF = 0.50 +/- 0.03, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Cell Survival↗