• Microbiology and Biotechnology Letters
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• v.24 no.5
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• pp.529-533
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• 1996

Melittin (ME) from honeybee venom has a broad range of strong antimicrobial activity, but it has hemolytic activity against eukaryotic cells. In order to design peptides with powerful antifungal activity without cytotoxic property of ME and understand structure-antifungal activity relationships, the hybrid peptides derived from the sequences of ME and cecropin A (CA) or magainin 2 (MA), MA(10-17)ME(1-12) and CA(1-8)ME(1-12). were synthesized by solid phase method. MA(10-17)ME(1-12) showed potent antifungal activity comparable to ME against Fusarium oxysporum with no hemolytic activity against human red blood cells. The hybrid peptides showed strong inhibi- tion of (1, 3)-$\beta$-D-glucan synthase. This result indicates that the antifungal activity of the hybrid peptides against Fusarium oxysporum is attributed to the inhibition of cell wall synthesis. The results therefore showed a successful design of a peptide having antifungal activity without hemolytic property.

• Journal of Ginseng Research
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• v.17 no.1
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• pp.52-60
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• 1993

Panax ginseng has been extensively used in the traditional oriental medicine as a restorative, tonic and Prophylactic agent. Recently, several reports regarding to anticancer effects of Panax ginseng has accumulated. These studies emphasized the fact that the anticancer activities might be due to a glycoside group called ginsenoside or pan.u saponin which has a water soluble characteristic. However, the authors and collaborates demonstrated that a highly lipid soluble component in extract of Panax ginseng roots contains a considerable cytotoxic activities against marine leukemic cells (L1210, P388) and human censer cells (HRT-18, HT-29, HCT48). This study was devised to observe the cytotoxic activities of Petroleum-ether extract of Panax giuseng roots (crude GBD and its Partially Purified fraction from silicic acid column chromatography (7 : 3 GX) against sarcoma-180 (5-180) and Walker carcinosar- coma 256 (Walker 256) in vivo, and murine leukemic Lymphocytes (L1210) and human rectal cancer cells (HRT-18) and human colon cancer cells (HT-29 and HCT48) in vitro. Each cell-line was cultured in medium containing serial concentration of the crude GX or 7 : 3 GX in vitro. A highly lipid soluble compound in the extract of Panax ginseng root was cytocidal to murine leukemic cells and human colon and rectal cancer cells in vitro. In the meantime, ginseng saponin derivatives did not have cytotoxic effects at its corresponding concentration. The growth rates of the cancer cells in medium containing ginseng extracts were inhibited gradually to a significant degree roughly in proportion to the increase of the extract concentration. The cytotoxic activity of 7 : 3 GX was about 3 times more potent than that of crude GX, one unit of cytotoxic activity against L1210 cells being equivalent to 2.54 Ug and 058 Ug for the crude GX and 7 : 3 GX, respectively. The Ri value of the active compound on silica- gel thin layer chromatography with petroleum-ether/ethyl ether/acetic acid mixture (90 : 10 : 1, v/v/v) as a developing so lvent was 053. While, the Panaxydol and Panaxynol as active compounds were purified from Petroleum-ether extract of Panax ginseng root by Drs. Ahn and Kim, and author found out that the one unit of cytotoxic activity of the Panaxydol and Panaxynol against L1210 cells being equivalent to 056 Ug and 0.3918 respectively. The survival times of mice inoculated with S-180 cells were extended about 1.5 to 2 times by the 7 : 3 GX treatment compared with their control group. The significantly decreased hemoglobin values of rats after inoculation with Walker 256 were recovered to normal range by oral administration of the crude Gt The synthetic levels of protein, DNA and RNA in human colon and rectal cancer cells were significantly diminished by treatment with the crude GX, which can explain a part of the origin of its anticancer activity.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.763-764
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• 2010

• Molecules and Cells
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• v.26 no.5
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• pp.454-458
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• 2008

Sex steroid hormone receptors play a central role in modulating telomerase activity, especially in cancer cells. However, information on the regulation of steroid hormone receptors and their distinct functions on telomerase activity within the mesenchymal stem cell are largely unavailable due to low telomerase activity in the cell. In this study, the effects of estrogen ($E_2$) treatment and function of estrogen receptor alpha ($ER{\alpha}$) and estrogen receptor beta ($ER{\beta}$) on telomerase activity were investigated in human mesenchymal stem cells (hMSCs). Telomerase activity and mRNA expression of the catalytic subunit of telomerase (hTERT) were upregulated by treatment of the cells with $E_2$. The protein concentration of $ER{\alpha}$ was also increased by $E_2$ treatment, and enhancement of $ER{\alpha}$ accumulation in the nucleus was clearly detected with immunocytochemistry. When $ER{\alpha}$ expression was reduced by siRNA transfection into hMSCs, the effect of $E_2$ on the induction of hTERT expression and telomerase activity was diminished. In contrast, the transient overexpression of $ER{\alpha}$ increased the effect of $E_2$ on the expression of hTERT mRNA. These findings indicate that the activation of hTERT expression and telomerase activity by $E_2$ in hMSCs depends on $ER{\alpha}$, but not on $ER{\beta}$.

• Safety and Health at Work
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• v.6 no.3
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• pp.192-199
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• 2015

Background: Overweight, obesity, and cardiovascular disease risk factors are prevalent among firefighters in some developed countries. It is unclear whether physical activity and cardiopulmonary fitness reduce cardiovascular disease risk and the cardiovascular workload at work in firefighters. The present study investigated the relationship between leisure-time physical activity, cardiopulmonary fitness, cardiovascular disease risk factors, and cardiovascular workload at work in firefighters in Hong Kong. Methods: Male firefighters (n = 387) were randomly selected from serving firefighters in Hong Kong (n = 5,370) for the assessment of cardiovascular disease risk factors (obesity, hypertension, diabetes mellitus, dyslipidemia, smoking, known cardiovascular diseases). One-third (Target Group) were randomly selected for the assessment of off-duty leisure-time physical activity using the short version of the International Physical Activity Questionnaire. Maximal oxygen uptake was assessed, as well as cardiovascular workload using heart rate monitoring for each firefighter for four "normal" 24-hour working shifts and during real-situation simulated scenarios. Results: Overall, 33.9% of the firefighters had at least two cardiovascular disease risk factors. In the Target Group, firefighters who had higher leisure-time physical activity had a lower resting heart rate and a lower average working heart rate, and spent a smaller proportion of time working at a moderate-intensity cardiovascular workload. Firefighters who had moderate aerobic fitness and high leisure-time physical activity had a lower peak working heart rate during the mountain rescue scenario compared with firefighters who had low leisure-time physical activities. Conclusion: Leisure-time physical activity conferred significant benefits during job tasks of moderate cardiovascular workload in firefighters in Hong Kong.

• Korean Journal of Pharmacognosy
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• v.36 no.1 s.140
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• pp.56-59
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• 2005

Urease plays an important role in the urea metabolism and the effect of urease activity on human and environment is enormous. For instance, urease acts as a virulence factor of the urinary and gastrointestinal tracts infections in human and animal, being involved in kidney stone formation, catheter encrusatation, pyelonephritis, ammonia encephalopathy, hepatic coma, and urinary tract infections. Widespread urease activity in soil induces a plant damage due to ammonia toxicity and pH increase. Therefore, urease activity regulation through urease inhibitors would lead to an enhanced efficiency of urea nitrogen uptake in plants and to the improved therapeutic strategies for ureolytic bacterial infections. To search for new inhibitory compounds on urease activity from herbs, MeOH extracts of herbs were screened. Among of them, the MeOH extracts of Areca catechu exhibited an excellent inhibitory effect on urease activity. Two compounds were isolated from the ethyl acetate fraction by the activity guided fractionation. Their chemical structures were identified as (+)-catechin(compound I) and allantoin(compound II) by spectroscopic evidence, respectively. Compound I showed a stronger inhibitory effect on urease activity than compound II.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.2070-2086
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• 2014

As a kind of personal lifelog data, activity data have been considered as one of the most compelling information to understand the user's habits and to calibrate diagnoses. In this paper, we proposed a robust algorithm to sampling rates for human activity recognition, which identifies a user's activity using accelerations from a triaxial accelerometer in a smartphone. Although a high sampling rate is required for high accuracy, it is not desirable for actual smartphone usage, battery consumption, or storage occupancy. Activity recognitions with well-known algorithms, including MLP, C4.5, or SVM, suffer from a loss of accuracy when a sampling rate of accelerometers decreases. Thus, we start from particle swarm optimization (PSO), which has relatively better tolerance to declines in sampling rates, and we propose PSO with an adaptive boundary correction (ABC) approach. PSO with ABC is tolerant of various sampling rate in that it identifies all data by adjusting the classification boundaries of each activity. The experimental results show that PSO with ABC has better tolerance to changes of sampling rates of an accelerometer than PSO without ABC and other methods. In particular, PSO with ABC is 6%, 25%, and 35% better than PSO without ABC for sitting, standing, and walking, respectively, at a sampling period of 32 seconds. PSO with ABC is the only algorithm that guarantees at least 80% accuracy for every activity at a sampling period of smaller than or equal to 8 seconds.

• Journal of Life Science
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• v.18 no.6
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• pp.884-890
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• 2008

Genistein, an isoflavone in soybean products, is a potential chemopreventive agent against various types of cancer. There are several studies documenting molecular alterations leading to cell cycle arrest at G2/M phase and induction of apoptosis; however, its mechanism of action and its molecular targets on the prostaglandin $E_2$ ($PGE_2$) production and telomere length regulation in human cancer remain unclear. In this study, we investigated the effect of genistein on the levels of cyclooxygenases (COXs) and telomere regulatory components of several human cancer cell lines (T24, human bladder carcinoma cells; U937, human leukemic cells; AGS, human stomach adenocarcinoma cells and SK-MEL-2, human skin melanoma cells). Genistein treatment resulted in the inhibition of cancer cell proliferation in a concentration-dependent manner. It was found that genistein treatment markedly decreased the levels of COX-2 mRNA and protein expression without significant changes in the expression of COX-1, which was correlated with a decrease in $PGE_2$ synthesis. Genistein treatment also partly inhibited the levels of human telomerase reverse transcriptase (hTERT) as well as human telomerase RNA (hTR) and telomerase-associated protein (TEP)-1, and the activity of telomerase. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of genistein.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.720-732
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• 1995

The use of transforming growth $factor-{\beta}1$ which functions as a potent biologic mediator regulating numerous activities of wound healing has been suggested for the promotion of periodontal regeneration. The mitogenic effects of transforming growth $factor-{\beta}1$ on human periodontal ligament cells and human gingival fibroblasts were evaluated by determining the incorporation of $[^3H]-thymidine$ into DNA of the cells dose-dependently. Cells were prepared with primary cultured fibroblasts and periodontal ligament cells from humans, and used in experiments were the fourth or sixth subpassage. Cells were seeded with serum free Dulbecco's modified Eagle medium containing 0.1% bovine serum albumine. The added concentrations of transforming growth $factor-{\beta}1$ were 0.25, 0.5, 1, 2.5, 5ng/ml and transforming growth $factor-{\beta}1$ were added to the quiescent cells for 24hours, 48hours, 72hours. They were labeled with lnCi/ml $[^3H]$ thymidine for the last 24hour of the each culture. The results were presented as the mean counts per minute (CPM) per well and S.D. of four determinations. The results were as follows. : The DNA synthetic activity of human gingival fibroblasts was increased dose-dependently by transforming growth $factor-{\beta}1$ at 24 hours, 48 hours and 72 hours. The maximum mitogenic effects were at the 48 hour application of transforming growth $factor-{\beta}1$. The DNA synthetic activity was generally more decreased at the 72 hour application than at the 48 hour the application of transforming growth $factor-{\beta}1$. The DNA synthetic activity of human periodontal ligament cells was increased dose-dependently by transforming growth $factor-{\beta}1$ at 24 hours and 48 hours. But the DNA synthetic activity was decreased at 5ng/ml of the 72 hour application. The maximum mitogenic effects were also at the 48 hour application of transforming growth $factor-{\beta}1$. The DNA synthetic activity of human periodontal ligament cells was generally more decreased at the 72 hour application than at the 48 hour application of transforming growth $factor-{\beta}1$. In the comparision of DNA synthetic activity between the human gingival fibroblasts and human periodontal ligament cells, the human gingival fibroblasts had more activity than the human periodontal ligament cells at all time application with the concentration of transforming growth $factor-{\beta}1$. In conclusion, transforming growth $factor-{\beta}1$ has an important roles in the stimulation of DNA synthesis in human periodontal ligament cells and human gingival fibroblasts, which means an increase in collagen synthesizing cells and thus, may be useful for clinical application in periodontal regenerative procedures.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2003.06a
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• pp.119-119
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• 2003