• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.1070-1076
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• 2009

Telomerase reverse transcriptase (TERT), which prolongs the replicative life span of cells, is highly upregulated in 85-90% of human cancers, whereas most normal somatic tissues in humans express limited levels of the telomerase activity. Therefore, TERT has been a potential target for anticancer therapy. Recently, we described a new approach to human cancer gene therapy, which is based on the group I intron of Tetrahymena thermophila. This ribozyme can specifically mediate RNA replacement of human TERT (hTERT) transcript with a new transcript harboring anticancer activity through a trans-splicing reaction, resulting in selective regression of hTERT-positive cancer cells. However, to validate the therapeutic potential of the ribozyme in animal models, ribozymes targeting inherent transcripts of the animal should be developed. In this study, we developed a Tetrahymena-based trans-splicing ribozyme that can specifically target and replace the mouse TERT (mTERT) RNA. This ribozyme can trigger transgene activity not only also in mTERT-expressing cells but hTERT-positive cancer cells. Importantly, the ribozyme could selectively induce activity of the suicide gene, a herpes simplex virus thymidine kinase gene, in cancer cells expressing the TERT RNA and thereby specifically hamper the survival of these cells when treated with ganciclovir. The mTERT-targeting ribozyme will be useful for evaluation of the RNA replacement approach as a cancer gene therapeutic tool in the mouse model with syngeneic tumors.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.5
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• pp.424-431
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• 2007

This thesis proposed H-Bridge Multi-Level Inverter for Fluidized Bed Combustion Boiler Secondary Air Fan in 200MW thermal power plant. The adjustable speed drive systems improve the efficiency in lightly load condition and extend the life span of motor by limiting the over current at starting. H-Bridge Multi-level Inverter is composed of the several series low voltage power cell inverters, which have the independent isolated do link, in each phase. KEPRI(Korea Electric Power Research Institute) has successfully completed to develop, install, and commission H-Bridge Multi-level Inverter(6.6kV, 1MVA). This thesis gives a full detail about H-Bridge Multi-level Inverter, proposed boiler DCS(Distributed Control System) logic, and commissioning test result.

• The Journal of Korean Medicine
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• v.23 no.2
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• pp.164-179
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• 2002

Object: Death rate due to hypertension, atherosclerosis, ischemic heart disease and cerebral infarction induced by Westernized diet and increased average life span is on the rise. Decrease in blood circulation, activation of thrombus generation and intravascular lipid accumulation, cited as the principal causes of the above mentioned diseases in recent studies, result in circulatory disturbance and blood vessel obstruction leading to ischemic cell death of heart, brain and peripheral vessels. Method: We investigated the biochemical changes in microvascular permeability, aggregation of platelet and the intravascular lipid accumulation in induced-diabetic rat using Streptozotocin. We also studied the effects of Woohwangcheongsirn-won after oral administration on blood circulation, platelet function and lipid metabolism. The results are as follows: I. Woohwangcheongsim-won increased blood circulation in microvessels. 2. Woohwangcheongsim-won increased the reduced erythrocyte deformability in diabetes. 3. Woohwangcheongsim-won induced the reduction of contents of 2, 3-DPG, but failed to affect the reduced contents of ATP in erythrocyte in diabetes. 4. Woohwangcheongsim-won reduced the activity of Ca/sup 2+/-ATPase in the membrane of erythrocyte. 5. Woohwangcheongsim-won reduced the platelet aggregation evoked by platelet agglutinin factor. 6. Woohwangcheongsim-won reduced the production of platelet-derived granules. 7. Woohwangcheongsim-won reduced the production of metabolites of arachidonic acid in diabetes, and also reduced the production of increased thromboxane B2. 8. Woohwangcheongsim-won reduced the synthesis of oxidized LDL-cholesterol. In conclusion, Woohwangcheongsim-won enhanced blood circulation in microvesseles, erythrocyte deformability and inhibited the increased platelet aggregation and the synthesis of oxidized LDL-cholesterol in diabetes. Therefore Woohwangcheongsim-won is believed to positively affect blood circulation (J Korean Oriental Med 2002;23(2):164-179)

• Korean Journal of Acupuncture
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• v.20 no.3
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• pp.101-114
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• 2003

To study the effects of anti-cancer, anti-metastasis and immune response improvement of herbal-acupuncture with Aucklandiae Radix diffusae herba infusion solution(AKL-HAS), we injected AKL-HAS into Zusanli(St36) of C57BL/6 mice implanted intravenously with B16-F10 melanoma. The results were obtained as follows : 1. In the experiment groups treated with Aucklandiae Radix(AKL) Herbal-Acupuncture, the spleen cell proliferation in Balb/c mouse was significantly increased compared with that of the control group. 2. In the experiment groups treated with Aucklandiae Radix(AKL) Herbal-Acupuncture, the percentage of $CD25^{+}/CD4^{+},\;CD8^{+}/CD3e^{+},\;CD69^{+}/B220^{+},\;NK1.1^{+}/CD3e^{+}$ cells in C57BL/6 mouse PBMCs was increased compared with that of the control group. 3. In the experiment groups treated with Aucklandiae Radix(AKL) Herbal-Acupuncture, the pulmonary colony number of C57BL/6 mice implanted intravenously with B16-F10 melanoma was decreased significantly compared with that of the control group. 4. In the experiment groups treated with Aucklandiae Radix(AKL) Herbal-Acupuncture, MST(Median Survial Time) and ILS(Increase of Life Span) of C57BL/6 mice implanted intravenously with B16-F10 melanoma were increased significantly compared with those of the control group.

• Journal of Obesity & Metabolic Syndrome
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• v.27 no.4
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• pp.248-253
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• 2018

Background: Sirtuins mediate metabolic responses to nutrient availability and slow aging and accompanying decline in health. This study was designed to assess the expressions of sirtuin1 (SIRT1) and sirtuin3 (SIRT3) in the liver and hypothalamus after duodenal-jejunal bypass (DJB) surgery in rats. Methods: A total of 38 rats were randomly assigned to either sham group (n=8) or DJB group (n=30). DJB group was again divided into three groups according to the elapsed time after surgery (10 weeks, DJB10; 16 week, DJB16; 28 week, DJB28). The mRNA and protein expressions of SIRT1 and SIRT3 in the liver and hypothalamus were measured by reverse transcription polymerase chain reaction, Western blot, and immunohistochemistry analyses. $NAD^+/NADH$ ratio was also measured. Results: We found increased mRNA and protein expression levels of SIRT1 in the liver of DJB16 and DJB28 groups compared with those of sham group. The mRNA and protein expressions of SIRT3 in the liver of DJB group increased proportionally to the elapsed time after DJB surgery. The mRNA expression levels of SIRT1 in the hypothalamus increased in DJB16 and DJB28 groups and protein expression levels of SIRT1 in the hypothalamus increased in DJB10, DBJ16, and DJB28 groups compared with sham group. We observed that mRNA and protein levels of SIRT3 in the hypothalamus of DJB group were not changed. Conclusion: This study proves that DJB increases SIRT1 and SIRT3 expressions in the liver and SIRT1 expression in the hypothalamus. These results suggest the possibility of sirtuins being involved in bypass surgery-induced metabolic changes.

• Journal of Life Science
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• v.9 no.4
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• pp.395-407
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• 1999

The queens of Korean native bumblebee species, Bombus ignitus were collected from the field in the spring of 1997 and reared under the various temperatures as 15$^{\circ}C$$\pm$1$^{\circ}C$, 2$0^{\circ}C$$\pm$1$^{\circ}C$, $25^{\circ}C$ $\pm$1$^{\circ}C$, 3$0^{\circ}C$$\pm$1$^{\circ}C$, 60%$\pm$5% of relative humidity and 14L : 10D, to investigate their ecological characteristics, as comparing with control(29$^{\circ}C$$\pm$1$^{\circ}C$, 60%$\pm$5% of relative humidity and red light). As a result, eggs were laid by foundation queen at 15$^{\circ}C$, but they didn't hatched out while at 2$0^{\circ}C$ eggs were laid by them and they hatched out. When a foundation queen laid eggs at $25^{\circ}C$ and they all were hatched out and normally grown. Finally they were developed to the normal colony. B. ignitus worker survived for 77days at 2$0^{\circ}C$, about 69days at $25^{\circ}C$, about 68days at 3$0^{\circ}C$ and about 63days at 29$^{\circ}C$(control). The first brood workers emerged in 25-27days from the egg which a foundation queen laid. At the various temperatures, the captive queens stand to lay eggs in about 18days at 15$^{\circ}C$, 15days at 2$0^{\circ}C$, 11days at $25^{\circ}C$, 11days at 3$0^{\circ}C$ and 4days in control. The first worker and the first drone from the egg cell of the collected queens appeared in about 27days and 72days at 2$0^{\circ}C$, 26days and 88days in $25^{\circ}C$, 24days and 65days at 3$0^{\circ}C$, 25days and 71days in control, respectively. In colony foundation, 33% of the collected queen at 2$0^{\circ}C$ and $25^{\circ}C$, 100% of the disposed queen at 3$0^{\circ}C$ and in control, and 67% of them at 3$0^{\circ}C$ and in control both produced new queens in 66days and 88days, respectively. The life span of the colony founded covered fro about 3 months at $25^{\circ}C$, 3$0^{\circ}C$ and in control. At lower temperatures, the life span of queen is shorter; 2 months at 15$^{\circ}C$ and 3 months at 2$0^{\circ}C$, respectively. A colony which normally developed, varied in size with rearing temperatures; about 20heads at 2$0^{\circ}C$, 482heads at $25^{\circ}C$, 330heads at 3$0^{\circ}C$ and 452heads in control. A foundation queen monthly oviposited 1.5egg cells at 15$^{\circ}C$, 3.0egg cells at 2 $0^{\circ}C$, 21.7egg cells at $25^{\circ}C$, 42.3egg cells at 3$0^{\circ}C$ and 47.0egg cells in control. As a colony developed in June and July, egg cells as well as daily average cells increased in number, as compared to those in May and August. Also, in June and July, interval(days) of egg laying is shorter than in May and August. Number of nectar pots during the colony development varied with rearing temperatures; 31pots at $25^{\circ}C$, 39pots at 3$0^{\circ}C$, 23pots in control. The emergence of new queen showed a distinctively different two patterns; early emerging type and late emerging type. Workers are rapidly increased from early in July to early in August at $25^{\circ}C$, but at 3$0^{\circ}C$ and in control, emergence of workers are remarkably increased from the middle of June and last until July. No new queen emerged at 15$^{\circ}C$, 2$0^{\circ}C$ and $25^{\circ}C$. New queens at 3$0^{\circ}C$ and in control emerged between late in June and early in July. Thus emergence of new queen was temperature dependent.

• Journal of Korean Traditional Oncology
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• v.15 no.1
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• pp.29-36
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• 2010

The anti-metastatic activity of water extract of Samguikoeuitang (WSGKE) consisting of Ginseng Radix, Angelicae Radix, Sophora flavescens and Coicis Semenwas examined. Ethanol extract of Samguikoeuitang (ESGKE) showed significant cytotoxicity against colon 26-M3.1 carcinoma cells, while WSGEK did not. However, WSGKE significantly increased the production of IL-6 and IL-12 in thioglycollate-induced macrophages from Balb/c mice, whereas ESGKE did not. WSGKE significantly increased natural killer (NK) cell cytotoxicity against effecter YAC-1 cells in an Effecter cells/Target ratio dependent manner. Also, WSGKE significantly suppressed lung metastasis after i.v. injection of colon26-M3.1 carcinoma cells. Inhibitory effect of WSGKE on lung metastasis totally abolished in NK cells-deficient mice by treatment with anti-asialo GM1 serum. In addition, the combination treatment of cisplatin and WSGKE (100 ${\mu}g$/mouse) prolonged the lifespan of mice inoculated by colon26-M3.1 cell. These findings suggest that WSGKE can inhibit lung metastasis and prolong life span via immunological enhancement as a Biological Response Modifier.

• KSBB Journal
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• v.20 no.3
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• pp.233-237
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• 2005

In order to investigate the feasibility of 30K protein from silkworm (Bombyx mori) hemolymph (SH) on the proliferation of human cells, a simple separating procedure by anion-exchange chromatography system with Q-Sepharose fast flow gel was established. The 30K protein was eluted with an optimized condition of 0.16 M sodium chloride in 20 mM tris buffer (pH 9.0). The separated 30K protein at three concentrations of 0.04, 0.12, and 0.4 mg/ml was added to the culture medium with various human cells, such as chondrocytes, periosteum-derived cells, and MRC-5 cells, and their growth rates were measured. The cell growth rate at protein concentration of 0.4 mg/ml was always higher than that without 30K protein in all human cells tested, suggesting that the 30K protein has positive effect on the increase of the life span of human cells.

• Archives of Pharmacal Research
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• v.21 no.5
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• pp.581-590
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• 1998

We developed a novel water-soluble camptothecin analobue, CKD602, and evaluated the inhibition of topoisomerase I and the antitumor activities against mammalian tumor cells and human tumor xenografts. CKD602 was a nanomolar inhibitor of the topoisomerase I enzyme in the cleavable complex assay. CKD602 was found to be 3 times and slightly more potent than topotecan and camptothecin as inhibitors of topoisomerase, respecitively. In tumor cell cytotoxicity, CKD602 was more potent than topotecan in 14 out of 26 human cancer cell lines tested, while it was comparable to camptothecin. CKD602 was tested for the in vivo antitumor activity against the human tumor xenograft models. CKD602 was able to imduce regression of established HT-29, WIDR and CX-1 colon tumors, LX-1 lung tumor, MX-1 breast tumor and SKOV-3 ovarian tumor as much as 80, 94, 76, 67, 87% and 88%, respectively, with comparable body weight changes to those of topotecan. Also the therapeutic margin (R/Emax: maximum tolerance dose/$ED-{58}$) of CKD602 was significantly higher than that of topotecan by 4 times. Efficacy was determined at the maximal tolerated dose levels using schedule dependent i.p. administration in mice bearing L1210 leukemia. On a Q4dx4 (every 4 day for 4 doses) schedule, the maximum tolerated dose (MTD) was 25 mg/kg per administration, which caused great weight loss and lethality in <5% tumor bearing mouse. this schedule brought significant increase in life span (ILS), 212%, with 33% of long-term survivals. The ex vivo antitumor activity of CKD602 was compared with that of topotecan and the mean antitumor index (ATI) values recorded for CKD602 were significantly higher than that noted for topotecan. From these results, CKD602 warrants further clinical investigations as a potent inhibitor of topoisomerase I.

• Korean Journal of Pharmacognosy
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• v.24 no.4
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• pp.267-281
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• 1993

To find antitumor components from higher fungi, the mycelia of Collybia confluens (Pers. ex Fr.) Kummer were cultured in artificial media. For efficient production of the mycelia, the influences of various modifications of culture conditions were examined. A water-soluble protein-bound polysaccharide fraction, Fr. A, was obtained from the mycelia by hot water extraction. When Fr. A was purified and fractionated by DEAE-cellulose and Sepbadex G-200 gel filtration chromatographies into four fractions which were designated B, C, C-I and C-II. The tumor inhibition ratios of these fractions ranged from 46% to 75% against the solid forms of sarcoma 180 in ICR mice at doses of 20 and 50 mg/kg/day when given intraperitoneally. Especially, Fr. C which was named Collyban(CB) exhibited a marked life-prolonging effect of the mice against ascitic forms of sarcoma 180 at a dose of 50 mg via i.p. administration. To extend spectra of the antitumor activities and eliminate the effects of allograft rejection, the characterization of antitumor effects of CB was performed in syngeneic host-tumor systems. It did not show any antitumor activity against L1210 murine leukemia in $CD_2Fl$ mice but prolonged their life span against ascitic forms of $MM_{46}$ carcinoma in $C_3H/He$ mice. Also it exhibited antitumor activity against human cervical cancer HeLa cells that were xenografted into nude mice having BALB/c genetic backgrounds by the i.p. injection at a dose of 100 mg/kg/day. In order to characterize the antitumor components, CB was examined by chemical analysis. It was acidic protein-bound polysaccharides composed of 31% polysaccharide, 27% protein and 3% hexosamine. CB was fractionated into two fractions, Fr. C-I(M.W.: 500 Kd) and Fr. C-II(M.W.:30 and 8 Kd) by Sephadex G-200 gel filtration chromatography.