• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.1-8
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• 1996

Human cytomegalovirus (HCMV) replication and $Ca^{2+}$ response in human cell lines of neuronal origin were investigated. SK-N-SH (neuroblastoma cells) and A172 cells (glioblastoma cells) were used. SK-N-SH cells were permissive for HCMV multiplication with a delay of one day compared to virus multiplication in human embryo lung (HEL) cells. The delay of HCMV multiplication in SK-N-SH cells appeared to be correlated with a delay in the $Ca^{2+}$ response. The cytoplasmic free $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) began to increase at 12 h p.i. in HCMV-infected SK-N-SH cells, while $[Ca^{2+}]_i$ increase in HCMV-infected HEL cells was observed as early as 3 h p.i. On the whole, the level of the increase in $[Ca^{2+}]_i$ in SK-N-SH cells was about 30% of that in HEL cells. On the other hand, in A172 cells infected with HCMV, neither production of infectious virus nor detectable increase in $[Ca^{2+}]_i$ was observed. Treatment with TPA of HCMV-infected SK-N-SH cells resulted in $[Ca^{2+}]_i$ increase at 6 h p.i. The stimulatory effect of TPA on HCMV- induced $[Ca^{2+}]_i$ increase continued until 12 h p.i., but TPA failed to stimulate the $Ca^{2+}$ response in SK-N-SH cells at 24 h p.i., suggesting that the effect of TPA had disappeared in SK-N-SH cells at that time point. In conclusion, SK-N-SH cells are permissive for HCMV replication and the delay in $Ca^{2+}$ response may be a consequence of the lower responsiveness of SK-N-SH cells than HEL cells to HCMV infection.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.30.2-30.2
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• 2010

Nano-scale p-n junction can generate various nano-scale functional devices such as nanowire light emitting diode, nanowire solar cell, and nanowire sensor. The core shell type nanowire p-n junction has been considered for the high efficient devices in many previous reports. On the other hand, although device efficiency is relatively lower, the cross bar type p-n junction has simple topological structure, suggested by C.M. Lieber group, to integrate easily many p-n junction devices in one board. In this study, for the integration of the cross bar nanowire p-n junction device, a simple fabrication route, employed dielectrophoretic array and direct printing techniques, was demonstrated by the successful fabrication and programmable integration of the nanowire cross bar p-n junction solar cell. This direct printing process will give the single nanowire solar cell the opportunity of the integration on the circuit board with other nanowire functional devices.

• KSBB Journal
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• v.32 no.3
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• pp.193-198
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• 2017

Sialylation is important in producing therapeutic proteins such as antibody, cytokine and fusion protein. Thus, enhancement of sialylation is usually performed in CHO cell cultures. ${\alpha}2,6$-Sialyltransferase (ST), which plays a key role in the attachment of ${\alpha}2,6-sialic$ acid, is present in human cells but not in Chinese hamster ovary (CHO) cells. Overexpression of ${\alpha}2,6-ST$ can be used for enhancing the degree of sialylation and achieving human-like glycosylation. In this study, we constructed CHO cells producing human cytotoxic T-lymphocyte antigen4-immunoglobulin (hCTLA4-Ig) as well as ${\alpha}2,6-ST$. Transfected CHO cells were selected using G418 and stable cell line was established. Profiles of viable cell density and hCTLA4-Ig titer in an overexpressed cell line were similar to those of a wild-type cell line. It was confirmed that the total amount of sialic acid was increased and ${\alpha}2,6-sialic$ acid was attached to the terminal residues of N-glycan of hCTLA4-Ig by ESI-LC-MS. Compared to 100% of ${\alpha}2,3-sialic$ acid in wild type cells, 70.9% of total sialylated N-glycans were composed of ${\alpha}2,6-sialic$ acid in transfected cells. In conclusion, overexpression of ${\alpha}2,6-ST$ in CHO cells led to the increase of both the amount of total sialylated N-glycan and the content of ${\alpha}2,6-sialic$ acid, which is more resemble to human-like structure of glycosylation.

• Journal of Chest Surgery
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• v.43 no.1
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• pp.39-46
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• 2010

Background: Preoperative chemotherapy has been adopted in our hospital as a standard treatment for non-small cell lung cancer patients with N2 disease. However, there have been cases of pathologic N2 disease that have been detected after curative-intent surgical resection. We retrospectively studied the outcomes of initial surgical treatment without neoadjuvant therapy in patients with unexpected N2 non-small cell lung cancer. Material and Method: Between January 1995 and June 2007, 225 patients were diagnosed with pathologic N2 disease after they underwent initial pulmonary resection without neoadjuvant therapy. Among them, 170 patients were preoperatively diagnosed with lymph node stage N0 or N1. We retrospectively reviewed their medical record and analyzed the outcomes. Result: The overall 5-year survival rate was 35.4%. The prognostic factors that were significantly associated with survival were no adjuvant therapy, histologic cell types other than adenocarcinoma or squamous cell carcinoma, a pathologic T stage more than T1, old age (${\geq}$70 years) and no mediastinoscopic biopsy. During the follow-up, 79 patients (46.5%) experienced tumor recurrence, including loco-regional recurrence in 20 patients (25.3%) and distant metastasis in 56 (70.9%). The 5-year recurrence-free survival rate was 33.7%. Conclusion: Based on our findings, the survival was good for patients with unexpected N2 non-small cell lung cancer and who underwent initial pulmonary resection without neoadjuvant therapy. A prospective comparative analysis is needed to obtain more conclusive and persuasive results.

• Food Science and Preservation
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• v.31 no.1
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• pp.99-111
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• 2024

The antioxidant potentials of ethanolic extracts derived from Aster yomena (A. yomena) were evaluated by assessing their total phenolic and flavonoid contents and radical scavenging activities. Our findings revealed that the 60% ethanolic extract of A. yomena exhibited the most robust antioxidant properties among all extracts tested. Specifically, the IC₅₀ values for the 2,2'-azino-bis (3-ethyl benzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities of the 60% ethanolic extract from A. yomena were determined to be 1,640.30 ㎍/mL and 2,655.10 ㎍/mL, respectively. Moreover, the inhibitory effect on malondialdehyde increased with the 60% ethanolic extract from A. yomena. To assess the neuroprotective effects, we examined the impact of the 60% ethanolic extract from A. yomena against H₂O₂-induced cytotoxicity in HT-22 (mouse hippocampal neuronal cell line) and SK-N-MC (human neuroblastoma cell line) cells. The results demonstrated a significant improvement in cell viability and reduced intracellular oxidative stress. Furthermore, the major bioactive compounds present in the 60% ethanolic extract from A. yomena were identified as chlorogenic acid and rutin through high-performance liquid chromatography (HPLC) analysis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.983-987
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• 2014

Nigella sativa (N sativa), commonly known as black seed, has been used in traditional medicine to treat many diseases. The antioxidant, anti-inflammatory, and antibacterial activities of N sativa extracts are well known. Therefore, the present study was designed to investigate the anticancer activity of seed extract (NSE) and seed oil (NSO) of N sativa against a human lung cancer cell line. Cells were exposed to 0.01 to 1 mg/ml of NSE and NSO for 24 h, then percent cell viability was assessed by 3-(4, 5-dimethylthiazol-2yl)-2, 5-biphenyl tetrazolium bromide (MTT) and neutral red uptake (NRU) assays, and cellular morphology by phase contrast inverted microscopy. The results showed NSE and NSO significantly reduce the cell viability and alter the cellular morphology of A-549 cells in a concentration dependent manner. The percent cell viability was recorded as 75%, 50%, and 26% at 0.25, 0.5, and 1 mg/ml of NSE by MTT assay and 73%, 48%, and 23% at 0.25, 0.5, and 1 mg/ml of NSE by NRU assay. Exposure to NSO concentrations of 0.1 mg/ml and above for 24 h was also found to be cytotoxic. The decrease in cell viability at 0.1, 0.25, 0.5, and 1 mg/ml of NSO was recorded to be 89%, 52%, 41%, and 13% by MTT assay and 85%, 52%, 38%, and 11% by NRU assay, respectively. A-549 cells exposed to 0.25, 0.5 and 1 mg/ml of NSE and NSO lost their typical morphology and appeared smaller in size. The data revealed that the treatment of seed extract (NSE) and seed oil (NSO) of Nigella sativa significantly reduce viability of human lung cancer cells.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.912-918
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• 2003

Mitotic centromere-associated kinesin (MCAK), which is a novel kinesin with a central motor domain, is believed to playa role in mitotic segregation of chromosome during the M phase of the cell cycle. In the present study, it is shown that a rabbit polyclonal antibody has been produced using the N-terminal region (187 aa) of human MCAK expressed in E. coli as the antigen. To express the N-terminal region in E. coli, the MCAK cDNA fragment encoding N-terminal 187 aa was obtained by PCR and was then inserted into the pET 3d expression vector. Molecular mass of the N-terminal region overexpressed in the presence of IPTG was 23.2 kDa on SDS-PAGE, and the protein was insoluble and mainly localized in the inclusion body that could be easily purified from the other cellular proteins. The N-terminal region was purified by electro-elution from the gel after the inclusion body was resolved on the SDS-PAGE. The antiserum obtained after tertiary immunization with the purified protein specifically recognized HsMCAK when subjected to Western blot analysis, and showed a fluctuation of the protein level during the cell cycle of human Jurkat T cells. Synchronization of the cell-cycle progression required for recovery of cells at a specific stage of the cell cycle was performed by either hydroxyurea or nocadazole, and subsequent release from each blocking at 2, 4, and 7 h. Northern and Western analyses revealed that both mRNA and protein of HsMCAK reached a maximum level in the S phase and declined to a basal level in the G1 phase. These results indicate that a polyclonal antibody raised against the N-terminal region (187 aa) of HsMCAK, overexpressed in E. coli, specifically detects HsMCAK (81 kDa), and it can analyze the differential expression of HsMCAK protein during the cell cycle.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.285-296
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• 1995

Anatomical studies of sink tissues are required for better understanding the biological plant growth system and energy metabolism. Kinematics of root growth zones of two genotypes of tall fescue (Festuca arundinacea Schreb.) receiving 50 or 200 ppm N were determined. Longitudinal anatomy and cell dynamics of root growth zones were studied and calculated. The root growth zone is organized similarly to the leaf growth zone which has cell division, elongation, and maturation zones, but the root growth zone is only about 3.0 mm long compared to 25 to 30 mm for the leaf growth zone. The root cap extends about 0.4 to 0.5 mm from the apical initial, while the cell elongation zone for both cortical and metaxylem cells extends about 3.3 mm from the apical initial for both genotypes and N levels. Root cap cells elongate from an initial length of about 5$\mu{m}$ long to a final length of about 40$\mu{m}$ before being sloughed. Initial lengths of cortical and metaxylem cells were about 8.5 $\mu{m}$ and 13.0 $\mu{m}$, respectively. Elongation of cortex and metaxylem cell showed sigmoidal curves with final lengths of about 120 $\mu{m}$ for cortex cells and 650 $\mu{m}$ for metaxylem cells. Initial size and final size for both types were not affected by N level, but cell fluxes and cell elongation rates of cortical and metaxylem cells were about double in low N. Cell production rates were about 5 to 6 times higher in cortical cells than in metaxylem cells. Differences in N caused a larger change in cell production rate, duration of cell elongation, and relative cell elongation rate than did the genotypes. These data indicate that N application affects root growth longitudinally by changing cell production rate and elongation rate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.153-160
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• 2000

We investigated the cytotoxic effects of roots and seeds Daucus carota L. on HepG2, HeLa, MCF7, SW626, C6 and NB41A3 cell lines by the MTT assay. Among extracts, the ethylacetate partition layer (DCMEA) of root of Daucus carota L. showed the strongest cytotoxic effects on HepG2, HeLa, C6 and NB41A3 cell lines. On the other hand, methanol(DCM), n-ethylacetate(DCMEA) and n-butanol(DCMB) extract of the seeds of Daucus carota L. also showed significant cytotoxic activities for all six cell lines. $\beta$-carotene, a well-known main component of Daucus carota L. was also tested for its cytotoxic effect. However, in all six cell lines, $\beta$-carotene falied to show significant cytotoxicity. Therefore, the anticancer effect of DCMEA of root fo Daucus carota L. and DCM, DCMH, DCMEA and DCMB extracts of seeds may be caused by components other than $\beta$-carotene. Futher studies are under way to isolate the compounds responsible for the significant cytotoxic activity.

• 대한생식의학회:학술대회논문집
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• 2006.06a
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• pp.176.2-176.2
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• 2006