• Journal of Plant Biotechnology
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• v.40 no.1
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• pp.18-26
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• 2013

Genetically modified (GM) rice Agb0101, which expresses the insecticidal toxin modified cry1Ac (mcry1Ac1) gene, was developed by the Rural Development Administration in Korea. To monitor the probable release of Agb0101 in the future, it is necessary to develop a reliable detection method. Here, we developed the PCR detection method for monitoring and tracing of GM rice. The primer pair (RBEgh-1/-2) from a starch branching enzyme (RBE4) gene was designed as an endogenous reference, giving rise to an expected PCR amplicon of 101 bp. For the qualitative PCR detection, construct- and event-specific primers were designed on the basis of integration sequence of T-DNA. Event-specific PCRs amplified specifically 5'- or 3'-junction region spanning the native genome DNA and the integrated gene construct, while none of amplified product was shown on crops, rice varieties, and other insect-resistant transgenic rice lines. The event-specific real-time PCR method was performed using TaqMan probe and plasmid pRBECrR containing both rice endogenous gene RBE4 sequence and 5'-junction sequence as the reference molecule. The absolute limit of quantification (LOQ) of real-time PCR was established with around 10 copies for one plasmid molecule pRBECrR. Thereafter, the different amounts of transgenic rice (1, 3, 5, and 10%, respectively) were quantified by using the established real-time PCR method, with a range below 19.55% of the accuracy expressed as bias, 0.06-0.40 of standard deviation (SD) and 3.80-7.01% of relative standard deviations (RSD), respectively. These results indicate that the qualitative and quantitative PCR methods could be used effectively to detect the event Agb0101 in monitoring and traceability.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.164-173
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• 2000

The p16 protein is a cyclin dependent kinase inhibitor that inhibits cell cycle progression from $G_1$ phase to S phase in cell cycle. Many p16 gene mutations have been noted in many cancer-cell lines and in some primary cancers, and alterations of p16 gene function by DNA methylation have been noticed in various kinds of cancer tissues and cell-lines. There have been a large body of literature has accumulated indicating that abnormal patterns of DNA methylation (both hypomethylation and hypermethylation) occur in a wide variety of human neoplasma and that these aberrations of DNA methylation may play an important epigenetic role in the development and progression of neoplasia. DNA methylation is a part of the inheritable epigenetic system that influences expression or silencing of genes necessary for normal differentiation and proliferation. Gene activity may be silenced by methylation of up steream regulatory regions. Reactivation is associated with demethylation. Although evidence or a high incidence of p16 alterations in a variety of cell lines and primary tumors has been reported, that has been contested by other investigators. The precise mechanisms by which abnormal methylation might contribute to carcinogenesis are still not fully elucidated, but conceivably could involve the modulation of oncogene and other important regulatory gene expression, in addition to creating areas of genetic instability, thus predisposing to mutational events causing neoplasia. There have been many variable results of studies of head and neck squamous cell carcinoma(HNSCC). This investigation was studied on 13 primary HNSCC for p16 gene status by protein expression in immunohistochemistry, and DNA genetic/epigenetic analyzed to determine the incidence, the mechanisms, and the potential biological significance of its Inactivation. As methylation detection method of p16 gene, the methylation specific PCR(MSP) is sensitive and specific for methylation of any block of CpG sites in a CpG islands using bisulfite-modified DNA. The genomic DNA is modified by treatment with sodium bisulfate, which converts all unmethylated cytosines to uracil(thymidine). The primers designed for MSP were chosen for regions containing frequent cytosines (to distinguish unmodified from modified DNA), and CpG pairs near the 5' end of the primers (to provide maximal discrimination in the PCR between methylated and unmethylated DNA). The two strands of DNA are no longer complementary after bisulfite treatment, primers can be designed for either modified strand. In this study, 13 paraffin embedded block tissues were used, so the fragment of DNA to be amplified was intentionally small, to allow the assessment of methylation pattern in a limited region and to facilitate the application of this technique to samlples. In this 13 primary HNSCC tissues, there was no methylation of p16 promoter gene (detected by MSP and automatic sequencing). The p16 protein-specific immunohistochemical staining was performed on 13 paraffin embedded primary HNSCC tissue samples. Twelve cases among the 13 showed altered expression of p16 proteins (negative expression). In this study, The author suggested that low expression of p16 protein may play an important role in human HNSCC, and this study suggested that many kinds of genetic mechanisms including DNA methylation may play the role in carcinogenesis.

• The Journal of the Korean bone and joint tumor society
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• v.11 no.1
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• pp.46-53
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• 2005

Purpose: Bisphosphonates (BPs) are the analogues of endogenous pyrophosphates: they have been used in the treatment of skeletal diseases such as Paget's disease, osteoporosis, and tumorinducing ostelysis, and are used in treatment of osteolytic metastasis of breast cancer recently. They are also used as one of the therapeutic agents for metastasis of prostatic cancer of which metastasis makes the mixed nature of osteolysis and ostegenesis. Although the action mechanism of BPs are well known for diseases with excessive osteoclastic bone resorption, the direct effect of BPs has not been known yet. This study was intended to see the tumor suppression capability of Zoledronic acid(ZOL) using nude mouse with osteosarcoma. Materials and Methods: MG-63 and HOS osteosarcoma cell lines were used and the transforemed MG-63-GFP and HOS-GFP cells, which were made for detection under fluorescent light, were subcutaneously injected to make osteosarcoma. The five 6-week male mice were used for the experiment at each group. After the injection, mice were cultivated until tumor pieces grow up to $3{\times}3{\times}3$ $mm^3$ and ZOL of 120 ug/kg was subcutaneously injected twice a week. Sizes of tumor were measured twice a week and photographed under fluorescent light. Results: In in vivo test with HOS osteosarcoma cell lines, mean size of tumors was 2,520 $mm^3$ in control group and was 131 $mm^3$ in ZOL group, which showed 94% of reduction comparing with the control ; with MG-63 osteosarcoma cell lines, mean size of tumors was 2,866 $mm^3$ in control group and was 209 $mm^3$ in test group with 72% of reduction (p<0.05). Conclusion: In in vivo tests with nude mice, we suggest that ZOL has direct effect on osteosarcoma cells and it would be used as one of the therapeutic agents for osteosarcoma, especially to ZOL-sensitive osteosarcoma cells.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.75-84
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• 2008

Colored potatoes are an excellent source of dietary polyphenols including anthocyanins. Generally, anthocyanins from fruits and vegetables exhibit anti-carcinogenesis and anti-cancer properties in vitro test. This experiment was conducted to know the effects of colored potato extracts contained anthocyanins on antimutagenic activity and anticancer activity to six human cancer cell lines containing LNCaP (androgen-dependent) prostate cancer cells. Extracts of three colored potatoes ('Hongyoung', 'Jayoung' and 'Jasim') and the white potato ('Superior') cultivars were used in this study. The extracts of three colored potatoes inhibited the mutagenicities induced by direct mutagen such as 4-nitro-quinoline-1-oxide (4-NQO) and another indirect mutagens of bezo(a)pyrene (BaP). Also, the extracts of 'Hoyoung' and 'Jayoung' showed higher antimutagenic activity than 'Jasim' and 'Superior' against to direct or indirect mutagen on both strains of TA98 and TA100. The activity of growth-inhibitory of extract of four potato cultivars were screened by SRB (sulphorhodamine B) method on diverse human cancer cells representing different types of cancers. Among the extract of four potato cultivars, the extract of 'Jasim' showed moderate inhibition on proliferation of LNCaP, ACHN and MOLT-4F cells and did not inhibit the proliferation of other cancer cells. On the other hand, extract of 'Superior' did not inhibit the proliferation of any tested cancer cell lines. However, the extracts of 'Hongyoung and Jayoung' inhibited the proliferation of cancer cells with $GI_{50}$ values ranging from 2.5 to $30\;{\mu}g/mL$. On the basis of the $GI_{50}$ values, it is clear that LNCaP cells were more sensitive to extracts of colored potato cultivars than other cancer cells. The extract of 'Jayoung' at $30\;{\mu}g/mL$ were more active and inhibited cell proliferation, and induced apoptosis in LNCaP cells. This result revealed that the extracts of colored potatoes are expected to be good candidate for development into source of antimutagenic and anticancer agent.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.618-623
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• 2011

Escherichia coli O157:H7 has been considered as a significant food-borne pathogen since its role in causing hemorrhagic colitis and hemolytic uremic syndrome in humans was recognized. In this study, we developed an immunochromatography (ICG) assay for the detection of E. coli O157:H7. E. coli O157:H7 monoclonal antibody (EC MAb) and colloidal gold were conjugated and its specificity was determined by the ICG treated with EC MAb and antimouse IgG at test and control lines, respectively. The detection limit of the ICG was $1{\times}10^5$ CFU/mL, and no crossreactivity was observed to other E. coli strains and major food-borne pathogens. To determine the minimum enrichment time for the ICG, meats and sprouts were inoculated with $1{\times}10$ CFU/100 ${\mu}L$ of E. coli O157:H7. After enrichment time of 10 and 2 h for meats and sprouts, respectively, up to $1{\times}10$ CFU/100 ${\mu}L$ of E. coli O157:H7 could be detected by ICG.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.439-445
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• 2006

Purpose : ${\alpha}$-Galactosylceramide (${\alpha}$-GalCer)-stimulated human $V{\alpha}24$ natural killer T (NKT) cells exert antitumor activity against some leukemia in a CD1d dependent and TCR-mediated manner, but could not kill CD1d - negative neuroblastoma (NB) cells. There are few reports about the direct antitumor effect of highly secreted cytokines by these cells on activation. In this study, using a cell-free supernatant (SPN) collected from plate bound hCD1d/${\alpha}$ GalCer tetramers-stimulated NKT cells, we examined whether they could be helpful in the immunotherapeutic treatment of NB. Methods : Cells were cultured in IMDM. The cytokines produced by NKT cells were measured with Cytometric Bead Array (CBA) analysis. Cell viability was evaluated by calcein-AM fluorescence with digital image microscopy scanning (DIMSCAN). The percentage of specific apoptosis was calculated by flow cytometric detection of apoptosis using annexin V and 7-AAD. Results : The activated NKT cells secreted high levels of IL-2, INF-${\gamma}$, TNF-${\alpha}$. The SPN was significantly cytotoxic against four out of eight tested NB cell lines, through mainly apoptosis as evidenced by annexin-V staining and inhibition with the pretreatment of pancaspase blocker. This apoptosis was significantly inhibited when anti-TNF-${\alpha}$ and anti-IFN-${\gamma}$ neutralizing mAbs were used separately and it was completely abolished when the two mAbs were combined. Conclusion : IFN-${\gamma}$ and TNF-${\alpha}$ produced by NKT cells could exert synergistically direct antitumor activity through apoptosis on some NB cell lines.

• The Korean Journal of Nuclear Medicine
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• v.37 no.3
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• pp.178-189
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• 2003

Purpose: Cellular uptakes of $^{99m}Tc-sestamibi(MIBI)\;and\;\;^{99m}Tc-tetrofosmin$ into cancer cell lines expressing multidrug resistance(MDR) were investigated and compared. The effects of verapamil and cyclosporin A, well-known multidrug resistant reversing agents, on cellular uptakes of both tracers were also compared. Materials and Methods: Doxorubicin-resistant HCT15/CL02 human colorectal cell and doxorubicin-resistant K562(Adr) and vincristine-resistant K562(Vcr) human leukemic cells were studied. RT-PCR analysis was used for the detection of mdr1 mRNA expression. MDR-reversal effects with verapamil and cyclosporine A were evaluated at different drug concentrations after incubation with MIBI and tetrofosmin for 1, 15, 30, 45 and 60 min, using single-cell suspensions at $1{\times}10^6cells/ml$ incubated at $37^{\circ}C$. Radioactivity in supernatants and pellets were measured with gamma well counter. Results: The cellular uptakes of MIBI and tetrofosmin in K562(Adr) and K562(Vcr) were lower than those of parental K562 cell. In HCT15/CL02 cells and K562(Adr) cells, there were no significant difference in cellular uptakes of both tracers, but cellular uptake of MIBI was higher than that of tetrofosmin in K562(Vcr) cells. Coincubation with verapamil resulted in a increase In cellular uptakes of MIBI and tetrofosmin. Verapamil increased cellular uptakes of MIBI and tetrofosmin by HCT15/CL02 cell by 11.9- and 6.8-fold, by K562(Adr) cell by 14.3- and 8-fold and by K562(Vcr) cell by 7- and 5.7-fold in maximum, respectively. Cyciosporin A increased cellular uptakes of MIBI and tetrofosmin by HCT15/CL02 cell by 10- and 2.4-fold, by K562(Adr) cell by 44- and 13-fold and by K562(Vcr) cell by 18.8- and 11.8-fold in maximum, respectively Conclusion: Taking together, MIBI and tetrofosmin are considered as suitable radiopharmaceuticals for defecting multidrug resistance. However, MIBI seems to be a better tracer than tetrofosmin for evaluating MDR reversal effect of the modulators. Since cellular uptakes of both tracers might differ in different cell types, further experiments regarding differences in cellular uptakes between cell types should be explored.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.408-413
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• 2008

Rice blast resistance is considered one of the most important traits in rice breeding and the disease, caused by Magnaporthe grisea Barr, has brought significant crop losses annually. Moreover, breakdown of resistance normally occurs in two to five years after cultivar release, thus a more durable resistance is needed for better control of this disease. We developed a new variety, Keumo3, which showed strong resistance to leaf blast. It was tested in 2003 to 2007 at fourteen blast nursery sites covering entire rice-growing regions of South Korea. It showed resistance reactions in 12 regions and moderate in 2 regions without showing susceptible reactions. Durability test by sequential planting method indicated that this variety had better resistance. Results showed that Keumo3 was incompatible against 19 blast isolates with the exception of KI101 by artificial inoculation. To understand the genetic control of blast resistance in rice cultivar Keumo3 and facilitate its utilization, recombinant inbred lines (RIL) consisting of 290 F5 lines derived from Akidagomachi/Keumo3 were analyzed and genotyped with Pizt InDel marker zt56591. The recombination value between the marker allele of zt56591 and bioassay data of blast nursery test was 1.1%. These results indicated that MAS can be applied in selecting breeding populations for blast resistance using zt56591 as DNA marker.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.261-266
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• 2004

Although significant progress has been made in the surgical treatment of esophageal carcinoma as well as in the detection of early stage esophageal carcinoma by diagnostic techniques, the prognosis of the esophageal carcinoma patients remain poor. The p53 gene product is known to regulate cell growth and proliferation. And the nm23 gene was identified originally as an anti-metastatic influence whose expression was correlated inversely with tumor metastatic potential in murine melanoma cell lines. This experiment was intended to know the relationship among the p53 and nm23 gene expression versus clinicopahologic characteristics of the esophageal cancer. Total 40 cases were collected from patients who had undergone esophagectomy at St. Mary's Hospital, Catholic university of Korea. Immunohistochemical stain for p53 mutant-type protein and nm23 protein was graded as <10% positive tumor cells: negative; 10∼30% positive tumor cells: ＋ ; 30∼50% positive tumor cells: ＋＋, and >50% positive tumor cells: ＋＋＋. The tumor invasion was grades as none:－ ; mild:＋ ; moderate:＋＋ ; severe: ＋＋＋. Overexpression of p53 protein and nm23 was not associated with the survival and cliniocopathologic characteristics of the esophageal cancer. Moreover, the combination analysis of p53 and nm23 revealed that there was no relationship between the gene expression and the clinicopatholic characteristics of the esophageal cancer.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.82.2-82.2
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• 2013

The NISS (Near-infrared Imaging Spectrometer for Star formation history) onboard NEXTSat-1 is being developed by KASI. The NISS will perform the imaging low-resolution spectroscopic observation in the near-infrared range for nearby galaxies, low background regions, starforming regions and so on. The off-axis reflecting telescope with a wide field of view (2 deg. ${\times}$ 2 deg.) will be operated in the wavelength range from 0.95 to $3.8{\mu}m$. In order to reduce thermal noise, a telescope and a HgCdTe infrared sensor will be cooled down to 200K and 80K, respectively. To evade a stray light outside a field of view and use limited space efficiently, the NISS adopted the off-axis reflective optical system. The primary and secondary mirrors, optomechanical part and mechanical structure were designed to use the same material. It will lessen the degradation of optical performance due to a thermal variation. The purpose of NISS is the observation of cosmic near-infrared background in the wide wavelength range as well as the detection of near-infrared spectral lines in nearby galaxies, cluster of galaxies and star forming regions. It will give us less biased information on the star formation history. In addition, we will demonstrate the space technologies related to the development of the Korea's leading near-infrared instrument for the future large infrared telescope, SPICA.