• Animal cells and systems
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• 제4권4호
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• pp.389-394
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• 2000

The Tcf-1 (1-cell factor-1) protein binds to the T-cell specific enhancer sequences and plays an architectural role in the assembly of transcriptional machinery. One of the Tcf family proteins, Tcf-4, was found to be an important regulator for colon cancer development where it activates specific genes upon binding to $\beta$-catenin following Wnt signaling. We were interested in the transcriptional regulatory activities of Tcf-1 and Tcf-4 proteins in T-cells and colon cancer cells. Transactivation assay was developed using a reporter plasmid containing luciferase gene under the control of Tcf responsive elements. Luciferase activity was determined following co-transfection of the reporter along with Tcf-1 and/or $\beta$-catenin expressing plasmids. Transcription was significantly induced by $\beta$-catenin expression in all cells. Tcf-1 by itself did not induce transcription in the mature T-cell lines, but overexpressed Tcf-1 greatly activated transcription in the immature T-cell line. In addition, transfected $\beta$-catenin induced apoptosis, but co-transfected Tcf-1 suppressed apoptosis in HEK293 cells. These results suggest that Tcf-1 and $\beta$-catenin differently regulate transcription and apoptosis.

• 한국어병학회지
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• 제35권1호
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• pp.93-102
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• 2022

본 연구에서는 뱀장어에 대한 trichlorfon (TCF)의 잔류허용기준(maximum residue level, MRL) 설정을 위한 기초 자료를 얻기 위하여 뱀장어를 대상으로 하여 trichlorfon (TCF) 노출에 따른 체내 잔류량 및 약물동태학적 분석을 실시했다. 28℃와 18℃ 에서 각각 30 ppm 및 150 ppm의 TCF를 30분간 약욕하여 이에 따른 체내 약물잔류농도를 LC-MS/MS로 분석한 결과를 바탕으로 PK solver program 을 이용하여 혈청, 근육 및 간에서 TCF의 약동학 파라미터를 얻었다. 혈청, 근육 및 간에서 최고 농도(C_max)는 25.87-357.42, 129.91-1043.73 및 40.47-375.20였고, 최고 농도 도달시간(T_max)는 0.13-1.32 h, 1.17-3.34 h, 및 0.14-5.40 h이었으며, 배설 반감기 (T_1/2)는 2.13-3.92 h, 5.30-10.35 h, 및 0.65-13.81 h이었다. 30 mg/L농도 투여군에서는 약욕 후 96시간이 지난 뱀장어의 혈청에서 TCF가 검출되지 않았으며, 근육 및 간에서는 336시간이후 부터 검출 한계 이하로 나타났다. 반면에 150 mg/L농도 투여군에서는 약욕 후 336시간이 지난 뱀장어의 혈청에서 TCF가 검출되지 않았지만, 근육 및 간에서는 336시간에도 검출되었다. 결론적으로 본 연구를 통해 얻은 결과들은 향후 양식 뱀장어에 대한 trichlorfon (TCF)의 잔류허용기준(MRL) 설정에 유용한 기초 자료로 활용 될 것으로 기대한다.

• 한국동물학회:뉴스레터
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• 제18권1호
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• pp.16-25
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• 2001

Wnt signaling의 주요 분자인 $\beta$-catenin의 기능과 조절에 관한 연구, 특히 TCF family 단백질과 함께 작용하는 신호전달에 관한 연구가 최근에 활발히 진행되고 있다. $\beta$-catenin 단백질은 Drosophila나 Xenopus의 발생초기에 중요한 역할을 한다는 것이 알려져 있고 Wnt (Wingless) 단백질에 의하여 활성화되는 신호전달 과정에 관여한다고 알려져 있으므로, TCF 단백질들이 Wnt signalling pathway에 작용한다는 것을 의미한다. 즉, $\beta$-catenin/TCF complex는 발생초기의 세포의 운명을 결정하는 세포의 분화에 중요하리라 생각된다. 또한 $\beta$-catenin/TCF complex는 세포의 암화에도 중요하다는 것이 보고되었다. 정상세포의 경우, $\beta$-catenin은 APC 라는 tumor suppressor에 의하여 결합하고 단백질의 분해가 유도되어 핵 안의 TCF와 결합하지 못하는데, 암세포의 경우 APC가 결실되었거나 $\beta$-catenin의 양이 과도하게 발현되어 암세포화 되는 것으로 보인다. 즉, $\beta$-catenin은 일종의 oncogene으로 작용하는 단백질이며, 그 작용에 필수적인 전사인자가 TCF라는 것이다. 특히, 대장암세포에서 이 $\beta$-catenin/TCF complex에 의해 활성화되는 유전자로서 c-myc과 cyclin Dl 등이 있는 것으로 보아, $\beta$-catenin/TCF 단백질은 세포의 증식 및 사멸에 관여하는 단백질들의 발현을 조절하는 매우 중요한 인자라고 생각된다.

• 한국세라믹학회지
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• 제45권1호
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• pp.43-47
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• 2008

The photocatalyst of $TiO_2$ coated on a fly ash composites (TCF) was prepared from precipitant dropping method to remove the acetaldehyde by photocatalytic reaction. The TCF were characterized by crystal aize, crystal structure and specific surface area. The photodegradation of acetaldehyde has been investigated using a UV-illuminated fixed photocatalytic reactor with TCF catalyst and P-25 catalyst in gas phase. The effect of photodegradation reaction conditions, such as initial concentration of acetaldehyde, concentration of oxidant in mixed gas and the light intensity on the photodegradation of acetaldehyde were investigated. P-25 catalyst showed the highest photodegradation of acetaldehyde and anatase $TiO_2$ coated TCF showed higher decomposition rate than rutile coated TCF. The photodegradation rate of acetaldehyde increased with the decrease of flow rate, initial concentration of acetaldehyde ($C_i$) and water vapor, however, it was increased with the increas of UV light intensity. The optimum conditions were weight of TCF=10 g, flow rate=50 ml/min $C_i$=100 ppm, concentration of oxygen=20%, concentration of water vapor=100 ppm.

• 대한한의학회지
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• 제32권3호
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• pp.35-43
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• 2011

Objectives: This study was performed to screen target-specific inhibitors of ${\beta}$-catenin/TCF signaling whose functional activation plays an important role in early events in carcinogenesis. Methods: To investigate the activation or suppression of ${\beta}$-catenin/TCF transcription, we established a transiently transfected cell line with a constitutively active ${\beta}$-catenin mutant gene whose product is not degraded. This cell line was also co-transfected with luciferase reporter gene constructs containing either an optimized (TOPflash) or mutant (FOPflash) TCF-binding element. We investigated cytotoxic effects using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt (MTS) assay. To find effective inhibitors of ${\beta}$-catenin/TCF signaling from medicinal herbs, the crude extracts of 99 types of medicinal herbs were screened using a luciferase assay system in HEK-293 and SH-SY5y cells. Results: At a concentration of $50{\mu}g$/ml, extracts of Angelica koreanae radix, Cannabis sativa semen, Ephedrae intermedia Schrenk radix, and Vitis rotundifolia fruit showed the following inhibitory effects on ${\beta}$-catenin/TCF signaling: $40{\pm}5.6%$, $23{\pm}6.1%$, $8{\pm}5.1%$, and $22{\pm}9.8%$ in ${\beta}$-catenin-activated HEK-293 cells and $9{\pm}4.7%$, $39{\pm}8.1%$, $39{\pm}6.4%$, and $42{\pm}10.1%$ in ${\beta}$-catenin-activated SH-SY5y cells, respectively. Crude extracts of E. radix were isolated by silica gel column chromatography, and two non-polar fractions of these extracts showed inhibitory effects on ${\beta}$-catenin/TCF signaling. Conclusions: In this study, we established a transiently transfected cell line as a screening system and found that various medicinal herb extracts had inhibitory effects on ${\beta}$signaling.

• The Korean Journal of Physiology and Pharmacology
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• 제26권6호
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• pp.469-478
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• 2022

WNT signaling plays an important role in cardiac development, but abnormal activity is often associated with cardiac hypertrophy, myocardial infarction, remodeling, and heart failure. The effect of WNT signaling on regulation of atrial natriuretic peptide (ANP) secretion is unclear. Therefore, the purpose of this study was to investigate the effect of Wnt agonist 1 (Wnta1) on ANP secretion and mechanical dynamics in beating rat atria. Wnta1 treatment significantly increased atrial ANP secretion and pulse pressure; these effects were blocked by U73122, an antagonist of phospholipase C. U73122 also abolished the effects of Wnta1-mediated upregulation of protein kinase C (PKC) β and γ expression, and the PKC antagonist Go 6983 eliminated Wnta1-induced secretion of ANP. In addition, Wnta1 upregulated levels of phospho-transforming growth factor-β activated kinase 1 (p-TAK1), TAK1 banding 1 (TAB1) and phospho-activating transcription factor 2 (p-ATF2); these effects were blocked by both U73122 and Go 6983. Wnta1-induced ATF2 was abrogated by inhibition of TAK1. Furthermore, Wnta1 upregulated the expression of T cell factor (TCF) 3, TCF4, and lymphoid enhancer factor 1 (LEF1), and these effects were blocked by U73122 and Go 6983. Tak1 inhibition abolished the Wnta1-induced expression of TCF3, TCF4, and LEF1 and Wnta1-mediated ANP secretion and changes in mechanical dynamics. These results suggest that Wnta1 increased the secretion of ANP and mechanical dynamics in beating rat atria by activation of PKC-TAK1-ATF2-TCF3/LEF1 and TCF4/LEF1 signaling mainly via the WNT/Ca²⁺ pathway. It is also suggested that WNT-ANP signaling is implicated in cardiac physiology and pathophysiology.

• Animal cells and systems
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• 제2권3호
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• pp.403-410
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• 1998

The Tcf-1 (T cell specific factor-1) is a transcription factor uniquely expressed in T-lineage cells. Its expression is developmentally regulated, which is high in the specific stage of immature thymocytes, but is much lower in mature T cells. We cloned the Tcf-1 gene by subtractive hybridization and found it to be highly expressed in the thymus compared to the mRNA level in the spleen as expected. Since apoptosis occurs enormously in the thymus, we were interested in whether Tcf-1 gene expression could be regulated by such a high level of apoptotic assault. By using T cell hybridoma 70.7 cells, we induced apoptosis by incubating cells with anti-CD3 antibody in vitro. After apoptosis induction, Tcf-1 mRNA level was found to be significantly reduced compared to normal cells. Since Tcf-1 is a transcription factor for the CD3-e gene, we tested how CD3-e expression is regulated in apoptotic cells. The surface level of CD3-e protein is also down-regulated after apoptosis induction. Such a down-modulation of CD3-e protein would reduce the TCR/CD3 complex on the cell surface, which would be an important regulator for T cell apoptosis.

• 대한기관식도과학회지
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• 제1권1호
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• pp.142-145
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• 1995

The tracheocutaneous fistula(TCF) may develop infrequently as a complication after tracheostomy. Prolonged tracheostomy tube dependence increases the risk of TCF developing, and in growth of stratified squamous epithelium lines the furrow connecting the tracheal mucosa and the skin, accounting for persistence of the fistulous tract. Such fistulas are a nuisance and create nursing and social problems including poor hygiene, aspiration, difficulty with speech, and depletion of pulmonary reserve. Surgical closure has generally been successful by primary closure, fistulectomy with primary closure, and closure by secondary intention following excision of the tracheocutaneous fistula. No large series compares the efficacy of these techniques and each has its own merits. Recent literature has purposed to minimizing complications. For ten years, from January 1985 to December 1994, the authors experienced 25 cases of TCF which were analyzed in respect to incidence and interval of cannulation, duration between decanulation and fistular closure, precedent disease, closure methods, and complications of TCF repair.

• Asian Pacific Journal of Cancer Prevention
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• 제15권7호
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• pp.3331-3333
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• 2014

Background: The results of previous researches that analyzed the association between genetic polymorphisms of transcription factor-7-like 2 (TCF7L2, rs7903146) and polycystic ovary syndrome (PCOS) were conflicting. Current systematic analysis was conducted to re-explore this association using updated materials. Materials and Methods: The PubMed database was used for data collection and the final search was conducted on January 3, 2014. For TCF7L2 rs7903146, a non-signficiant slight increase in risk of PCOS development was observed under three genetic models (dominant model: OR=1.06, 95%CI: 0.93-1.21, p>0.05; recessive model: OR=1.12, 95%CI: 0.87-1.43, p> 0.05; homozygous model: OR=1.14, 95%CI: 0.87-1.47, p>0.05). In the subgroup analyses in Asian group, allele susceptibility of PCOS was calculated (allele model: OR=1.00, 95%CI: 0.74-1.35, p>0.05; dominant model: OR=0.98, 95%CI: 0.71-1.35, p>0.05; recessive model: OR=1.79, 95%CI: 0.33-9.84, p>0.05; homozygous model: OR=1.78, 95%CI: 0.32-9.80, p>0.05), the differences were again not statistically significant. Conclusions: The findings of this systemic analysis suggest that the polymorphism of TCF7L2 rs7903146 may not be associated with the susceptibility to PCOS.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.111.1-111.1
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• 2012

Interest in flexible transparent conducting films (TCFs) has been growing recently mainly due to the demand for electrodes incorporated in flexible or wearable displays in the future. Indium tin oxide (ITO) thin films, which have been traditionally used as the TCFs, have a serious obstacle in TCFs applications. SWNTs are the most appropriate materials for conductive films for displays due to their excellent high mechanical strength and electrical conductivity. In this work, the fabrication by the spraying process of transparent SWNT films and reduction of its sheet resistance on PET substrates is researched Arc-discharge SWNTs were dispersed in deionized water by adding sodium dodecyl sulfate (SDS) as surfactant and sonicated, followed by the centrifugation. The dispersed SWNT was spray-coated on PET substrate and dried on a hotplate. When the spray process was terminated, the TCF was immersed into deionized water to remove the surfactant and then it was dried on hotplate. The TCF film was then was doped with Au-ionic doping treatment, rinsed with deionized water and dried. The surface morphology of TCF was characterized by field emission scanning electron microscopy. The sheet resistance and optical transmission properties of the TCF were measured with a four-point probe method and a UV-visible spectrometry, respectively. This was confirmed and discussed on the XPS and UPS studies. We show that 87 ${\Omega}/{\Box}$ sheet resistances with 81% transmittance at the wavelength of 550nm. The changes in electrical and optical conductivity of SWNT film before and after Au-ionic doping treatments were discussed. The effect of Au-ion treatment on the electronic structure change of SWNT films was investigated by Raman and XPS.