Effect of equal daily doses achieved by different power densities of low-level laser therapy at 635 nm on open skin wound healing in normal and diabetic rats.

BACKGROUND AND OBJECTIVE: Despite the fact that the molecular mechanism of low-level laser therapy (LLLT) is not yet known, the exploitation of phototherapy in clinical medicine and surgery is of great interest. The present study investigates the effects of LLLT on open skin wound healing in normal and diabetic rats. MATERIALS AND METHODS: Four round full-thickness skin wounds on dorsum were performed in male adult nondiabetic (n = 24) and diabetic (n = 24) Sprague-Dawley rats. AlGaInP (635 nm, wavelength; 5 J/cm(2), daily dose) was used to deliver power densities of 1, 5, and 15 mW/cm(2) three times daily until euthanasia. RESULTS: PMNL infiltration was lower in the irradiated groups (15 mW/cm(2)). The synthesis and organisation of collagen fibres were consecutively enhanced in the 5 mW/cm(2) and 15 mW/cm(2) groups compared to the others in nondiabetic rats. In the diabetic group the only significant difference was recorded in the ratio PMNL/Ma at 15 mW/cm(2). A significant difference in the number of newly formed capillaries in the irradiated group (5, 15 mW/cm(2)) was recorded on day six after injury compared to the control group. CONCLUSION: LLLT confers a protective effect against excessive inflammatory tissue response; it stimulates neovascularization and the early formation of collagen fibres.

Effects of docetaxel, doxorubicin and cyclophosphamide on human breast cancer cell line MCF-7.

BACKGROUND: Cell viability assays are important tools in oncological research. The purpose of this study was to evaluate the effect of docetaxel, doxorubicin and cyclophosphamide on the metabolic activity of MCF-7 breast cancer cell line. MATERIALS AND METHODS: Antiproliferative effect of cytostatics on MCF-7 cells was measured using the standard colorimetric test. The MCF-7 cell line was exposed to cytostatics for 24 hours. The metabolic activity was evaluated over the 24 hours. RESULTS: According to the statistical analysis, the change in the growth rate was significant (p<0.05) for the 120 nM docetaxel and above the 200 nM doxorubicin treatment in comparison with sensitive MCF-7 cells. When considering drugs in combination (60 nM docetaxel with 200 nM doxorubicin and 60 nM docetaxel with 500 nM doxorubicin) after the addition of 600 nM cyclophosphamide, we found a statistically significant decrease of metabolic activity of the MCF-7 cell line (p<0.05). CONCLUSION: Cyclophosphamide at 600 nM seems to enhance the influence of docetaxel when combined with doxorubicin.

Effects of equal daily doses delivered by different power densities of low-level laser therapy at 670 nm on open skin wound healing in normal and corticosteroid-treated rats: a brief report.

The optimal parameters for low-level laser therapy (LLLT) for wound healing are still open to discussion. Hence, our study was aimed at comparing the effects of different power densities of LLLT at 670 nm in rats. Four round full-thickness skin wounds were placed on the backs of 16 rats which were divided into two groups (non-steroid and steroid-treated). Three wounds were stimulated daily with a diode laser (daily dose 5 J/cm(2)) at different power densities (5, 15 and 40 mW/cm(2), respectively), and the fourth wound served as a control. Six days after surgery all animals were killed and samples removed for histological evaluation. Significant acceleration of fibroblast proliferation and new vessel formation was observed in wounds treated at the selected power densities. No significant differences were found in corticosteroid-treated rats. In conclusion, LLLT with the methodology used improved wound healing in non-steroid rats, but was not effective after corticosteroid-treatment.