This study investigated the effects of rare-earth fertilizer on the shoot cuttings’ rooting of Vitex rotundifolia L. and Tamarix chinensis Lour. The shoot cutting test was carried in 2008 and the main results are summarized as follows. The rate of rooting and the average roots increased in both number and length when rare-earth fertilizer is treated in V. rotundifolia and T. chinensis in comparison to those of the untreated control plot. In particular, when rare-earth fertilizer is diluted with water 1/2500, the rooting outstandingly increases. This result is almost similar to the effect of the rooting stimulant, IAA. Although there is no differentiation in its rooting rate according to the density, the rooting of T. chinensis shows a 100 percent effect on in the entire treated plot but not in the untreated control plot, so it is usable as a rooting stimulant. As for shoot cuttings' rooting, depending on the time immersed in diluted solution of rare-earth fertilizer, both V. rotundifolia and T. chinensis showed relatively higher percentages in all treatment plot immersed for 60 minutes than for 10 minutes. In conclusion, considering the results of the rooting percentage and the average number and length of roots of V. rotundifolia and T. chinensis, the shoot cuttings' rooting appeared higher in percentage when they were immersed in the rooting stimulant for sixty minutes with a lower density than 1/2500. This result shows that rare-earth fertilizer can be utilized as an alterative for IAA rooting stimulants currently available in the market.

It has been reported that light-emitting diodes(LED) can be used in the treatment of oral diseases. Although bio-stimulatory effects of LED irradiation such as promotion of wound healing have been well known, there are few reports about molecular mechanisms associated with wound healing by LED irradiation. The purpose of the present study was to investigate the expression pattern of various extracellular matrix(ECM) molecules in relation to wound healing after LED irradiation on primary human gingival fibroblasts(hGFs) in vitro. The source of light for irradiation was a continuous-wave LED emitting at a wavelength of 635 nm, and manufactured that energy density was 5 mW/cm2 on sample surfaces. The hGFs were irradiated for 1 hour at 37℃ in 5% CO2 humidified chamber. Experimental samples were acquired at 0 (right after irradiation), 24 and 48 hour after irradiation. To investigate the molecular mechanisms associated with wound healing, we examined the mRNA expression of 6 types of collagens, 7 types of matrix metalloproteinases(MMPs) and 4 types of tissue inhibition of metalloproteinases(TIMPs) after LED irradiation by RT-PCR. The mRNA expression of collagen 4, MMP-3, 9, and 16, and TIMP-3 was influenced by LED irradiation. Generally, the collagen expression of the irradiation group was slightly increased, particularly collagen 4 was significantly increased at 0 hour. The expression of MMP-3 was increased at 0 and 24 hours and MMP-16 was increased at 24 hours, respectively. The expression of MMP-9 was decreased at 0 hour and increased at 24 and 48 hours. The mRNA expression of TIMP-3 was significantly decreased at 24 and 48 hours after irradiation. These results suggest that the altered expression of ECM molecules after LED irradiation may contribute to the accelerated wound healing.

It has been reported that light-emitting diodes(LED) can be used in the treatment of oral diseases. Although bio-stimulatory effects of LED irradiation such as promotes stimulation of wound healing have been well known, there are few reports about molecular mechanism associated with cell cycle by LED irradiation. The purpose of present study was to examine the molecular event in cell cycle of LED irradiation on primary human gingival fibroblast(hGF) in vitro. The source of light for irradiation was a continuous-wave LED emitting at a wavelength of 635nm, and manufactured that energy density was 5mW/cm2 on sample surface. The hGF were irradiated for 1 hour at 37℃ in 5% CO2 humidified chamber. Experimental samples were acquired at 0 (right after irradiation), 8 and 24 hour after irradiation. To investigate the molecular mechanisms associated with cell cycle, growth phase was determined by flow cytometry and mRNA expression of cyclin A, cyclin B, cyclin D1, cyclin E, cdc2, PCNA, p18, p27, p21, and p53 were determined by real time RT-PCR. Flow cytometric analysis demonstrated the percentage of cells in the G1 and S phase were decreased, but the G2 phase increased, which showed cells irradiated by LED were transitioned from S to G2 phase. For mRNA expression, cyclin B, cdc2, PCNA and p53 were increased at 0 hour after irradiation, and most of cell cycle molecules were increased at 8 hour after irradiation. At 24 hour after irradiation, cyclin A, cyclin E, PCNA and p18 were increased. Taken together, LED irradiation induced proliferation of hGF cells through transition from S to G2 phase.