The effect of He-Ne laser (632.8 nm) and Solcoseryl in vitro.

He-Ne laser (632.8 nm) and Solcoseryl (SS), a non-protein calf haemodialysate, were used in the enhancement of wound healing. Nonetheless, a study on the use of He-Ne laser with SS has not been done. The purpose of this study is to determine the effect of He-Ne laser biostimulation in combination with SS on Chinese hamster ovary (CHO) and human skin fibroblast (HSF). A dose response for the cloning efficiency (CE) of CHO and HSF cells in 5% fetal bovine serum in minimum essential medium (FBS-MEM) with 6-125 micrograms/ml SS and He-Ne laser using an optimum power density of 1.25 mW/cm2 and cumulative doses (CD) of 60-600 mJ/cm2 given for three consecutive days, were done. The combined effects of He-Ne laser 180 mJ/cm2 with 6 and 12 micrograms/ml SS were determined. Quadruplicate cultures were done. Student t-test was used to determine differences of treatment groups from controls. CHO and HSF CE were increased using 180 mJ/cm2 laser by 13.1% +/- 4.5% (p < 0.0025) and 39.1% +/- 7.9% (p < 0.0005); SS 6 micrograms/ml by 14.4% +/- 8.7% (p = 0.01) and 20.7% +/- 10.9% (p = 0.01); SS 12 micrograms/ml by 17.7% +/- 6.3% (p = 0.001) and 23.9% +/- 5.6% (p < 0.0025); laser + SS 6 micrograms/ml by 15.1% +/- 8.8% (p < 0.01) and 60.9% +/- 9.4% (p < 0.0001); laser + SS 12 micrograms/ml by 23.0% +/- 1.5% (p < 0.0001) and 70.7% +/- 11.4% (p < 0.0001), respectively. Additional significant increases in CE were observed on CHO using laser + SS 12 micrograms/ml by 8.6% +/- 1.3% (p < 0.025) and on HSF using laser + SS 6 micrograms/ml and laser + SS 12 micrograms/ml by 15.6% +/- 6.8% (p < 0.025) and 22.7% +/- 10.6% (p = 0.01), respectively, when compared to the effect of 180 mJ/cm2 laser. Results suggest that further stimulation can be achieved by using He-Ne laser with SS. This could be exploited as a new treatment modality.

Effect of He-Ne laser (632.8 nm) and Polygen on CHO cells.

OBJECTIVE: We determined the effect of He-Ne laser biostimulation in combination with Polygen (PG) on Chinese hamster ovary (CHO) cells. BACKGROUND DATA: Several studies have shown that He-Ne laser (632.8 nm), growth factors, and growth hormone can enhance cellular proliferation and that the use of low-level laser stimulation combined with growth factor stimulation has scientific support. PG, an animal protein extract containing a blend of growth factors and growth hormone, was used together with a He-Ne laser to determine their efficacy in the enhancement of cellular proliferation. METHODS: The dose-response curves for the colony-forming ability of CHO cells in 5% FCS-MEM with 6-125 microg/ml PG and He-Ne laser with an optimum power density of 1.25 mW/cm2 and cumulative doses of 60-600 mJ/cm2 was given for 3 consecutive days. The combined effects of He-Ne laser 180 mJ/cm2 with 6 and 12 microg/ml PG were determined. Quadruplicate cultures were performed. The student's t-test was used to ascertain differences of treated groups from controls. RESULTS: The mean number of colonies (MNC) was increased using 180 mJ/cm2 laser by 13.2% (p < 0.01); 6 and 12 microg/ml PG by 19.2% (p < 0.0025) and 13.2% (p = 0.01); laser + PG 6 microg/ml by 23.2% (p < 0.001) and laser + PG 12 microg/ml by 20.5% (p < 0.001). An additional significant increase of 8.8% (p < 0.05) and an insignificant 6.4% (p = 0.086) by laser + PG 6 microg/ml and laser + PG 12 microg/ml were observed, respectively, when compared to the solitary effect of laser. CONCLUSIONS: Results suggest that the He:Ne laser or PG can stimulate CHO cell proliferation and that further stimulation can be achieved by using the He:Ne laser and PG simultaneously. This combination could be useful as a new treatment modality.

Comparison of wound healing process using Argon and Krypton lasers.

OBJECTIVE: We compared the wound healing process on Sprague-Dawley rats between Argon Laser and Krypton Laser, and calculated the laser actual doses after correction on wound healing on rats and estimated the clinical doses on wound healing for human skin. SUMMARY BACKGROUND DATA: Laboratory work provided some support for the use of low-intensity laser radiation in wound healing. Some studies found that laser irradiation may either enhance, inhibit, or has no effect on the function of a variety of microorganisms and cells. Animal studies also offered some basis for treatment. Improvements, particularly in the earliest phases of wound healing, have been reported following laser irradiation. METHODS: We used Argon Laser (488-514 nm) and Krypton Laser (670 nm) in the study. The laser beam was delivered through a system of fiber optic in Argon Laser and reflector in Krypton Laser. The rats treated were restrained in a Plexiglas cage without anesthesia during the laser irradiation period. The percentage of the wound healing acceleration in days and size, actual doses, and estimated clinical doses were calculated as follows: AccD = (1-TD/CD) x 100%, AccS = (1-TA/CA) x 100%, AD = D(in) - D(gl) - D(SR) and ECD = AD = D(sr), respectively. RESULTS: The acceleration effects of wound healing in days (AccD) were 22.93% and 14.54%, size reductions (AccS) were 41.93% and 30.41% at the optimal stimulative incident dose of 20 J/cm2. Zero bioactivation shown at the incident doses of 80 J/cm2 and 100 J/cm2. The inhibitory effects of wound healing in days were -7.72% and -3.37%, in size reduction were -13.35% and -12.88% at the maximal inhibitory incident dose of 140 J/cm2 for Argon and Krypton Lasers, respectively. The actual doses were 5.21 J/cm2 and 4.03 J/cm2, the estimated clinical doses were 5.50 J/cm2 and 4.25 J/cm2 at optimal stimulative incident dose 20 J/cm2 for Argon and Krypton Lasers, respectively. CONCLUSIONS: Low power laser therapy at the appropriate dosimetric parameters can provide the acceleration effects of wound healing on rats. The effects were dependent with the doses and laser wavelengths used. In this experiment, the optimum stimulative dose was 20 J/cm2 and the Argon Laser with 488 nm was more effective than the Krypton Laser with 670 nm. The zero bioactivation and inhibition effect of wound healing on rats occurred in Argon Laser and Krypton Laser.

Photodynamic therapy: tumor volume limitation and tumor response for murine fibrosarcoma.

The clonogenic survival rates and tumor growths following photodynamic therapy (PDT) were studied as a function of tumor volume for RIF-1 using C3H mice as an animal model. The clonogenic survival rates showed a saturation level approaching a 99.8% survival rate for large volumes (above 1,900 mm3), possibly indicating poor light utilization of 630 nm because of the limited tissue penetration and/or tumor hypoxia. With a small tumor volume [less than 150 mm3], the survival rate (less than 0.3%) showed an exponential increase with volume. The survival rates (less than 0.03%) corresponding to a volume lower than 50 mm3 gave complete tumor eradication. On the other hand, partial response and recurrence were noticed with volumes larger than 90 mm3, which had more than approximately 0.1% survival rates. After PDT, all tumors responded with immediate swelling and skin discoloration, followed by necrosis, tumor delay, and regrowth. Regrowth rate and tumor cell doubling time were slower than the control growths and decreased further following superficial irradiation with a second interstitial illumination. The regrowth rates were slow for small initial tumor volumes and fast for large initial tumor volumes. Also, the delay period was longer for the small initial tumor volumes in comparison to a shorter period for the medium tumor volumes and very low probability of delay for the large volumes.

Repair of potentially lethal damage in yeast induced by fast neutrons.

Survival curves of 3 diploid (D7) yeast strains: one wild-type, one deficient in excision of pyrimidine dimers (UV-sensitive) and one blocked in DNA double-strand-break repair (X-ray-sensitive), were compared after irradiation with cyclotron-produced fast neutrons. It was observed that both the UV-sensitive (rad3/rad3) and the X-ray-sensitive (rad52/rad52) mutants were more sensitive to neutrons than the wild-type. The role of DNA double-strand-breaks in neutron-induced cell death was further studied by comparing the relative sensitivity of the rad52/rad52 mutant to gamma-rays and fast neutrons. A comparison of the dose modification factors revealed that the deficiency in DNA double-strand-break repair did not make the yeast cells more sensitive to neutrons than to photons, which suggests that lesions of a different type may also be produced by neutrons. Survival curves obtained upon immediate plating and after delayed plating of neutron-irradiated cells showed that all 3 yeast strains were efficient in liquid holding recovery. The role of different repair pathways in cellular recovery from neutron-induced lethal damage is discussed.