• Journal of Periodontal and Implant Science
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• v.31 no.3
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• pp.611-623
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• 2001

Cyclosporin A is a cyclic polypeptide produced by the metabolism of fungi. It is widely used at present as immunosuppressive treatment following organ transplants. It is also used to deal with autoimmune diseases such as rheumatoid arthritis or type II diabetes. Gingival hyperplasia is one of the most frequent side-effects associated with the prescription of Cyclosporin A. The mechanisms involved in Cyclosporin A induced gingival hyperplasia are not yet clear. In vitro Cyclosporin A promotes proliferation of gingival fibroblasts, that Cyclosporin A act as a mitogen. Its action is based on mitosis of gingival fibroblasts regulated by cell cycle regulatory proteins. It was the purpose of the present study to examine the effects of Cyclosporin A on human gingival fibroblasts by means of biological and biochemical criteria. In this present study, we examined change of cell proliferation, cell activity, cell viability and cell cycle progression after application of Cyclosporin A. We also examined expression of cell cycle regulatory proteins by western blot analysis. Human gingival fibroblasts were cultured for 48 hours with application of Cyclosporin A at concentrations of 0.01, 0.1, 1, and 10 ng/ml. Cyclosporin A(1 ng/ml) significantly increased the cell activity of gingival fibroblast. Proliferation and viability of gingival fibroblasts were also increased in group treated with 1 ng/ml of Cyclosporin A compared to control group. In the cell cycle analysis, S phase was increased and G1 phase was decreased in the group treated with 1 ng/ml of Cyclosporin A. Cyclosporin A increased the expression of cdk4 and inhibited the expression of pRB and p21. These results suggest that 1 ng/ml of Cyclosporin A may increase the cell cycle progression of human gingival fibroblasts, and its mechanisms may increase the expression of cdk4 and decrease the expression of pRB and p21.

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.583-592
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• 2003

The gas phase identity nucleophilic substitution reactions of halide anions (X = F, Cl, Br) with cyclopentadienyl halides (1) are investigated at the B3LYP/6-311+G**, MP2/6-311+G** and G2(+)MP2 levels involving five reaction pathways: σ-attack $S_N2$, β-$S_N$2'-syn, β-$S_N$2'-anti, γ-$S_N$2'-syn and γ-$S_N$2'-anti paths. In addition, the halide exchange reactions at the saturated analogue, cyclopentyl halides (2), and the monohapto circumambulatory halide rearrangements in 1 are also studied at the same three levels of theory. In the σ-attack $S_N2$ transition state for 1 weak positive charge develops in the ring with X = F while negative charge develops with X = Cl and Br leading to a higher energy barrier with X = F but to lower energy barriers with X = Cl and Br than for the corresponding reactions of 2. The π-attack β-$S_N$2' transition states are stabilized by the strong $n_C-{\pi}^{*}_{C=C}$ charge transfer interactions, whereas the π-attack γ-$S_N$2' transition states are stabilized by the strong $n_C-{\sigma}^{*}_{C-X}$ interactions. For all types of reaction paths, the energy barriers are lower with X = F than Cl and Br due to the greater bond energy gain in the partial C-X bond formation with X = F. The β-$S_N$2' paths are favored over the γ-$S_N$2' paths only with X = F and the reverse holds with X = Cl and Br. The σ-attack $S_N2$ reaction provides the lowest energy barrier with X = Cl and Br, but that with X = F is the highest energy barrier path. Activation energies for the circumambulatory rearrangement processes are much higher (by more than 18 kcal $mol^{-1}$) than those for the corresponding $S_N2$ reaction path. Overall the gas-phase halide exchanges are predicted to proceed by the σ-attack $S_N2$ path with X = Cl and Br but by the β-$S_N$2'-anti path with X = F. The barriers to the gas-phase halide exchanges increase in the order X = F < Br < Cl, which is the same as that found for the gas-phase identity methyl transfer reactions.

• Journal of Life Science
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• v.21 no.9
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• pp.1288-1294
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• 2011

Resveratrol, a kind of phytochemical, is presented in grape skins. Resveratorl exerts antiproliferative, anti-cancer and pro-apoptotic activities in cancer cells. Mammalian target of rapamycin (mTOR) is a critical regulator of cellular growth and proliferation, and it is known to be a strategic target for anti-cancer therapeutic uses. mTOR is a major downstream of the PI3K/Akt pathway, which is activated in various cancer cells. It also plays an important role in the survival, proliferation and angiogenesis of cells. Cyclooxygenase-2 (COX-2) is an important protein that mediates inflammatory processes. It plays an important role in various tumors by affecting cell proliferation, mitosis, apoptosis and angiogenesis. In this study, we have investigated the effects of resveratrol on apoptosis through mTOR and COX-2 expression in MCF-7 breast cancer cells. The treatment of resveratrol with different concentrations inhibited proliferation of MCF-7. The data showed that resveratrol induced apoptotic cell death of cancer cells and decreased mTOR and COX-2 expression. These results suggest that resveratrol induces apoptosis of MCF-7 breast cancer cells by inhibiting mTOR and COX-2 expression.

• Molecules and Cells
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• v.37 no.11
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• pp.785-794
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• 2014

Mitophagy, a cellular process that selectively targets dysfunctional mitochondria for degradation, is currently a hot topic in research into the pathogenesis and treatment of many human diseases. Considering that hypoxia causes mitochondrial dysfunction, which results in cell death, we speculated that selective activation of mitophagy might promote cell survival under hypoxic conditions. In the present study, we introduced the Regulator of calcineurin 1-1L (Rcan1-1L) to initiate the mitophagy pathway and aimed to evaluate the effect of Rcan1-1L-induced mitophagy on cell survival under hypoxic conditions. Recombinant adenovirus vectors carrying Rcan1-1L were transfected into human umbilical vein endothelial cells and human adult cardiac myocytes. Using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide MTT assay and Trypan blue exclusion assay, Rcan1-1L overexpression was found to markedly reverse cell growth inhibition induced by hypoxia. Additionally, Rcan1-1L overexpression inhibited cell apoptosis under hypoxic conditions, as detected by annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) apoptosis assay. Meanwhile, the mitochondria-mediated cell apoptotic pathway was inhibited by Rcan1-1L. In contrast, knockdown of Rcan1-1L accelerated hypoxia-induced cell apoptosis. Moreover, Rcan1-1L overexpression significantly reduced mitochondrial mass, decreased depolarized mitochondria, and downregulated ATP and reactive oxygen species production. We further delineated that the loss of mitochondrial mass was due to the activation of mitophagy induced by Rcan1-1L. Rcan1-1L overexpression activated autophagy flux and promoted translocation of the specific mitophagy receptor Parkin into mitochondria from the cytosol, whereas inhibition of autophagy flux resulted in the accumulation of Parkin-loaded mitochondria. Finally, we demonstrated that mitochondrial 1permeability transition pore opening was significantly increased by Rcan1-1L overexpression, which suggested that Rcan1-1L might evoke mitophagy through regulating mitochondrial permeability transition pores. Taken together, we provide evidence that Rcan1-1L overexpression induces mitophagy, which in turn contributes to cell survival under hypoxic conditions, revealing for the first time that Rcan1-1L-induced mitophagy may be used for cardioprotection.

• Current Research on Agriculture and Life Sciences
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• v.18
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• pp.53-60
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• 2000

Seedling characteristics of rice sowed at different sowing date in an automatic facility were studied at different days after sowing (DAS). The objective was to determine the optimum sowing date and age of rice seedlings at three locations in the Kyongbuk Province of Korea viz, Andong, Euisung and Kyongsan. Heigbt and shoot dry weight of rice seedlings increased from 10 to 20 DAS and with a delay in sowing time from April to June. In these intervals shoot dry weight-height ratio decreased. For rice seeded in the last ten days of April, optimum seedling characteristics were attained between 15 to 20 DAS at Andong and Euisong and 15 DAS at Kyongsan. At the three locations, 10-day-seedlings exhibited superior characteristics to 15- and 20-day-seedlings for rice seeded in May and June. Rice seedlings of different ages were transplanted at a paddy field to determine the effect of seedling age on yield potential. The mean yield of 10-day-seedlings was 5% higher than that of 35-day-seedlings raised by the conventional method. The yield of 20-day-seedlings was 9% lower than that of 35-day-seedlings. Varietal differences in seedling characteristics of 13 rice cultivars were evaluated for the seedlings seeded in the automatic facility on June. Ten-day old seedlings ranged in height from 13.3 to 17.5 cm and shoot dry weight from 7.7 to 9.4 mg. Two cultivars, Daesanbyeo and Hwayeongbyeo, exhibited superior seedling traits compared to the remaining 11 cultivars and were, therefore, better adapted to the automatic seedling-raising facility.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.1
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• pp.143-149
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• 2016

This study evaluated the shear behavior of geogrid reinforced ballast material using a large scale direct shear test and discrete element method (DEM) based on PFC 3D program. The direct shear test was conducted on ballast materials that have different particle size distributions. Whereas the test results revealed that the shear strength generally increased with the larger particle size of ballast material without geogrid reinforcement, the shear behavior of ballast material was found to change pertaining to the relationship between particle size distribution and geogrid rib size. Generally, it is deemed the effectiveness of reinforcement can be achieved when the rib size is two times greater than average particle size. A numerical analysis based on DEM was conducted to verify the test results. The geogrid modeling was successfully completed by calibration process along with sensitivity analysis to have actual tensile strength provided by manufacturer. With a given geogrid model, the parametric evaluation was further carried out to examine the interactive behavior between geogrid and ballast material. Consequently, it was found that the effectiveness zone of geogrid reinforcement generated within a specific depth.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2125-2134
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• 2000

This research was to develope the economical treatment processes of the landfill leachate to meet the legal discharge standards. To achieve this purpose, experiments were conducted in laboratory to choose the optimum process and to obtain the design factors before a pi!ot-scale test. The concept of the process developing in this research was using the reverse osmosis system. The submerged membrane bio-reactor was used to achieve pre-treatment of reverse osmosis system and the concentrate was treated by evaporator with land fill gas as a fuel. The results of the research showed that SS, $BOD_5$, $COD_{cr}$, $NH_4{^+}-N$ and T-N were removed 99.0%, 43.0%, 12.9%, 48.5% and 18.7% respectively in the submerged membrane bio-reactor. The reverse osmosis system could remove $BOD_5$, $COD_{cr}$, $NH_4{^+}-N$ and T-N as an efficiency of97.5%, 97.6%, 79.7% and 85.4% respectively. The evaporator could remove $COD_{cr}$, $NH_4{^+}-N$ and T-N as an efficiency of 90.5%, 50.6% and 63.3% respectively. However the condensed water of the evaporator was not satisfied the legal standard and should be treated in reverse osmosis with the pre-treated leachate.

• Herbal Formula Science
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• v.25 no.1
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• pp.51-68
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• 2017

Objectives : Oxidative stress due to excessive accumulation of reactive oxygen species (ROS) is one of the risk factors for the development of several chronic diseases, including neurodegenerative diseases. Methods : In the present study, we investigated the protective effects of cheongnoemyeongsin-hwan (CNMSH) against oxidative stress‑induced cellular damage and elucidated the underlying mechanisms in neuronal-derived SH-SY5Y cells. Results : Our results revealed that treatment with CNMSH prior to hydrogen peroxide (H2O2) exposure significantly increased the SH-SY5Y cell viability, indicating that the exposure of the SH-SY5Y cells to CNMSH conferred a protective effect against oxidative stress. CNMSH also effectively attenuated H2O2‑induced comet tail formation, and decreased the phosphorylation levels of the histone ${\gamma}H2AX$, as well as the number of apoptotic bodies and Annexin V‑positive cells. In addition, CNMSH exhibited scavenging activity against intracellular ROS generation and restored the mitochondria membrane potential (MMP) loss that were induced by H2O2, suggesting that CNMSH prevents H2O2‑induced DNA damage and cell apoptosis. Moreover, H2O2 enhanced the cleavage of caspase-3 and degradation of poly (ADP-ribose)-polymerase, a typical substrate protein of activated caspase-3, as well as DNA fragmentation; however, these events were almost totally reversed by pretreatment with CNMSH. Furthermore, CNMSH increased the levels of heme oxygenase-1 (HO-1), which is a potent antioxidant enzyme, associated with the induction of nuclear factor-erythroid 2-related factor 2 (Nrf2). According to our data, CNMSH is able to protect SH-SY5Y cells from H2O2-induced apoptosis throughout blocking cellular damage related to oxidative stress through a mechanism that would affect ROS elimination and activating Nrf2/HO-1 signaling pathway. Conclusions : Therefore, we believed that CNMSH may potentially serve as an agent for the treatment and prevention of neurodegenerative diseases caused by oxidative stress.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.29-36
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• 1999

A series of N-phenyl-O-phenylthionocarbamate derivatives were synthesized and determinated fungicidal activities in vitro against gray mold (Botrytis cinerea) and capsicum phytophthora blight (Phytophthora capsici) which showed resistance and sensitivity to benomyl and metalaxyl as systemic fungicides, respectively. The structure-activity relationship (SAR) was investigated by Free-Wilson analysis method and Hansch method. From the basis on the findings, the N-phenyl(X) groups had more contributions than O-phenyl(Y) groups did and ortho-substituents on the N-phenyl group showed high fungicidal activities. Especially, 4-cyano substituent, 2 as X-group showed 50% inhibition($pI_{50}=5.50$) of hyphae growth at 0.8ppm against resistance P. capsici (RPC) And hydroxyl substituents, 12 and 23 displayed the highest fungicidal activity against resistant B. cinerea (RBC), sensitive B. cinerea (SBC), and sensitive P. capsici (SPC). Antifungal activities of SPC were dependent upon molar refractivity (MR) constant and those of others relied on hydrophobic parameters (${\sigma}$ and logP). For increasing fungicidal activity against RPC and SBC, the optimum values of the sigma (${\sigma}$) and field(F) constants as electron withdrawing groups were 0.32 and 0.18, respectively.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.263-271
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• 2006

The purpose of this study was undertaken to compare ability of frozen-thawed sperm characteristics between two strains (miniature pig and Duroc). The semen was collected by gloved-hand method into a pre-warmed ($37^{\circ}C$) thermos bottle. The semen was diluted with same volume extender and added to LEY solution for freezing. The diluted semen was placed in 0.5 ml straws, and freezing was initiated by exposing the straws to liquid nitrogen ($LN_2$) vapours for 10 min before placing them into $LN_2$ for cryopreservation. The frozen-semen straw were thawed at 20, 37 and $50^{\circ}C$ for 1 min, 45 sec and 10 sec within water-bath. The semen sample were evaluated at 0, 3, 6, 9, and 12 h after incubation at $37^{\circ}C$ for analysis of sperm ability. Abnormality of spermatozoa in miniature pig was significantly (p<0.05) higher than that in Duroc at 0, 9 and 12 h of post-thawing incubation after frozen-thawing. The percentage of F-patterned spermatozoa in miniature pig was significantly (p<0.05) lower, while the percentage of AR (acrosome reacted spermatozoa) pattern was higher in the miniature than in the Duroc. On the other hand, there was no significant difference in the viability of spermatozoa thawed at different temperature ($20^{\circ}C\;and\;37^{\circ}C$) between two species, but the viability in miniature pig was higher (p<0.05) than in Duroc when sperm was thawed at $50^{\circ}C$. In conclusion, this study suggest that suitable freezing method for miniature pig semen is required for increasing post-thawing viability and fertilization capacity.