• 대한설비공학회지:설비저널
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• 제12권4호
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• pp.252-263
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• 1983

In the briquet-burning hot water boiler the $SO_x$-dew point is calculated and found to be between $130^{\circ}C\;and\;154^{\circ}C$. The corrosion rate depends on the surface temperature and the concentration of the condensate on the surface. The concentration of the condensate is decided acoording to the difference detween $SO_x$-dew point and the surface temperature. When the surface temperature is $80^[\circ}C$, the concentration of the condensate is also high (0.15N). Therefore the high concentration and high temperature promote the high corrosion rate of $14{\times}13^{-3}g/100cm^2{\cdot}hr$ on the SS41 material. On the other hand, when the surface temperatures are $60^{\circ}C\;and\;40^{\circ}C$, the concentrations and the co..sion rates are reduced dramatically to $0.11\;N,\;8.6{\tiems}10^{-3}g/100cm^2{\cdot}hr$ and $5{\tiems}10^{-4}g/100cm^2{\cdot}hr$ respectively.

• Reproductive and Developmental Biology
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• 제31권4호
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• pp.267-272
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• 2007

Human embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo and have the capacity to differentiate into various types of cells in the body. Hence, these cells may potentially be an indefinite source of cells for cell therapy in various degenerative diseases including neuronal disorders. For clinical applications of human ES cells, directed differentiation of these cells would be necessary. The objective of this study is to develop the culture condition for the expansion of neural precursor cells derived from human ES cells. Human ES cells were able to differentiate into neural precursor cells upon a stepwise culture condition. Neural precursor cells were propagated up to 5000-fold in cell numbers over 12-week period of culture and evaluated for their characteristics. Expressions of sox1 and pax6 transcripts were dramatically up-regulated along the differentiation stages by RT-PCR analysis. In contrast, expressions of oct4 and nanog transcripts were completely disappeared in neural precursor cells. Expressions of nestin, pax6 and sox1 were also confirmed in neural precursor cells by immunocytochemical analysis. Upon differentiation, the expanded neural precursor cells differentiated into neurons, astrocytes, and oligodendrocytes. In immunocytochemical analysis, expressions of type III ${\beta}$-tubulin and MAP2ab were observed Presence of astrocytes and oligodendrocytes were also confirmed by expressions of GFAP and O4, respectively. Results of this study demonstrate the feasibility of long-term expansion of human ES cell-derived neural precursor cells in vitro, which can be a potential source of the cells for the treatment of neurodegenerative disorders.

• Clinical and Experimental Reproductive Medicine
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• 제35권1호
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• pp.39-48
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• 2008

목 적: 본 연구에서는 신생 생쥐 고환으로부터 다분화능 생식줄기세포주 (MGSCs)를 확립하고, 배아체 형성을 통한 삼배엽성 세포로의 분화 가능성을 확인하고자 하였다. 연구방법: 고환에서 유래한 MGSCs를 확립하기 위하여 생후 $2{\sim}3$일된 생쥐 고환 조직으로부터 세포들을 분리하여 1% FBS를 첨가한 생쥐 배아줄기세포주 배양조건에서 배양하였다. MGSCs 콜로니가 형성된 후에는 배양액의 FBS의 농도를 15%로 높였다. 이러한 과정으로 확립된 MGSCs의 미분화 및 분화 특성을 배아줄기세포주와 비교, 분석하였다. 결 과: 신생 생쥐 고환 조직에서 수획한 세포들로 실시한 9번의 배양실험에서 2개의 MGSCs 세포주를 확립하였다. MGSCs 세포주와 생쥐 배아줄기세포 모두에서 미분화 표지인자인 Thy-1, Oct-4, Nanog, Sox2의 발현과 alkaline phosphatase 활성을 관찰할 수 있었으며, MGSCs의 미세구조 또한 생쥐 배아줄기세포와 유사하였다. MGSCs에서 형성된 배아체에서 삼배엽성 표지유전자의 발현을 확인하였다. 결 론: 본 연구의 결과는 배아줄기세포의 윤리적인 문제점을 극복할 수 있는 고환 유래의 다분화능 MGSCs가 생물공학과 재생의학에서 효율적으로 이용될 수 있는 가능성을 보여준 것으로 생각된다.

• 미생물학회지
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• 제53권4호
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• pp.320-322
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• 2017

그람 음성이며 긴 막대 모양의 betaproteobacteria에 속하는 GR16-43을 한강 발원지 검룡소에서 분리하였다. GR16-43 균주에 대한 유전체분석을 실시하였으며, G + C 비율이 67.12%인 4,806,848 bp 크기의 염기서열을 얻었다. 유전체 특징은 황산화와 관련된 다량의 유전자를 보유하고 있어 균주의 잠재적 중요성을 보여준다. 이러한 결과는 GR16-43 균주가 빈영양 담수 환경에서의 적응 연구를 위한 유전체 정보를 제공한다.

• BMB Reports
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• 제53권12호
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• pp.622-627
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• 2020

Cancer stem cells (CSCs) or tumor-initiating cells are thought to play critical roles in tumorigenesis, metastasis, drug resistance, and tumor recurrence. For the diagnosis and targeted therapy of CSCs, the molecular identity of biomarkers or therapeutic targets for CSCs needs to be clarified. In this study, we identified CD166 as a novel marker expressed in the sphere-forming CSC population of A2780 epithelial ovarian cancer cells and primary ovarian cancer cells. The CD166+ cells isolated from A2780 cells and primary ovarian cancer cells highly expressed CSC markers, including ALDH1a1, OCT4, and SOX2, and ABC transporters, which are implicated in the drug resistance of CSCs. The CD166+ cells exhibited enhanced CSC-like properties, such as increased sphere-forming ability, cell migration and adhesion abilities, resistance to conventional anticancer drugs, and high tumorigenic potential in a xenograft mouse model. Knockdown of CD166 expression in the sphere-forming ovarian CSCs abrogated their CSC-like properties. Moreover, silencing of CD166 expression in the sphere-forming CSCs suppressed the phosphorylation of focal adhesion kinase, paxillin, and SRC. These results suggest that CD166 plays a key role in the regulation of CSC-like properties and focal adhesion kinase signaling in ovarian cancer.

• 한국수정란이식학회지
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• 제29권1호
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• pp.91-99
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• 2014

Oxygen consumption is a useful parameter for evaluating mammalian embryo quality, since individual bovine embryos was noninvasively quantified by scanning electrochemical microscopy (SECM). Recently, several approaches have been used to measure the oxygen consumption rates of individual embryos, but relationship between oxygen consumption and pregnancy rates of Hanwoo following embryo transfer has not yet been reported. In this study, we measured to investigate the correlation between oxygen consumption rate and pregnancy rates of Hanwoo embryo using a SECM. In addition to, the expression of pluripotent gene and anti-oxidant enzyme was determined using real-time PCR by extracting RNA according to the oxygen consumption of in vivo embryo. First, we found that the oxygen consumption significantly increased in blastocyst-stage embryos (blastocyst) compared to early blastocyst stage embryos, indicating that oxygen consumption reflects the embryo quality (Grade I). Oxygen consumption of blastocyst was measured using a SECM and total cell number of in vitro blastocyst was enumerated by counting cells stained by propidium iodide. The oxygen consumption or GI blastocysts were significantly higher than those of GII blastocysts ($10.2{\times}10^{15}/mols^{-1}$ versus $6.4{\times}10^{15}/mols^{-1}$, p<0.05). Total cell numbers of in vitro blastocysts were 74.8, 90.7 and 110.2 in the oxygen consumption of below 10.0, 10.0~12.0 and over $12.0{\sim}10^{15}/mols^{-1}$, respectively. Pregnant rate in recipient cow was 0, 60 and 80% in the transplantation of embryo with the oxygen consumption of below 10.0, 10.0~12.0 and over $12.0{\times}10^{15}/mols^{-1}$, respectively. GPX1 and SOD1 were significantly increased in over -10.0 group than below 10.0 groups but in catalase gene, there was no significant difference. On the other hand, In OCT-4 and Sox2, pluripotent gene, there was a significant difference (p<0.05) between the below-10.0 ($0.98{\pm}0.1$) and over 10.0 ($1.79{\pm}0.2$). In conclusion, these results suggest that measurement of oxygen consumption maybe help increase the pregnant rate of Hanwoo embryos.

• BMB Reports
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• 제54권10호
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• pp.528-533
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• 2021

Osteoarthritis (OA) is a degenerative disorder that can result in the loss of articular cartilage. No effective treatment against OA is currently available. Thus, interest in natural health products to relieve OA symptoms is increasing. However, their qualities such as efficacy, toxicity, and mechanism are poorly understood. In this study, we determined the efficacy of avenanthramide (Avn)-C extracted from oats as a promising candidate to prevent OA progression and its mechanism of action to prevent the expression of matrix-metalloproteinases (MMPs) in OA pathogenesis. Interleukin-1 beta (IL-1β), a proinflammatory cytokine as a main causing factor of cartilage destruction, was used to induce OA-like condition of chondrocytes in vitro. Avn-C restrained IL-1β-mediated expression and activity of MMPs, such as MMP-3, -12, and -13 in mouse articular chondrocytes. Moreover, Avn-C alleviated cartilage destruction in experimental OA mouse model induced by destabilization of the medial meniscus (DMM) surgery. However, Avn-C did not affect the expression of inflammatory mediators (Ptgs2 and Nos) or anabolic factors (Col2a1, Aggrecan, and Sox9), although expression levels of these genes were upregulated or downregulated by IL-1β, respectively. The inhibition of MMP expression by Avn-C in articular chondrocytes was mediated by p38 kinase and c-Jun N-terminal kinase (JNK) signaling, but not by ERK or NF-κB. Interestingly, Avn-C added with SB203580 and SP600125 as specific inhibitors of p38 kinase and JNK, respectively, enhanced its inhibitory effect on the expression of MMPs in IL-1β treated chondrocytes. Taken together, these results suggest that Avn-C is an effective candidate to prevent OA progression and a natural health product to relieve OA pathogenesis.

• Journal of Ginseng Research
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• 제45권4호
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• pp.510-518
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• 2021

Background: Gintonin is a newly derived glycolipoprotein from the roots of ginseng. The purpose of this study is to investigate the anti-arthritic efficacy of Gintonin on various proteases and inflammatory mediators that have an important role in arthritis. Methods: Fibroblast-like synoviocytes (FLS) were treated with Gintonin and stimulated with interleukin (IL)-1β 1 hour later. The antioxidant effect of Gintonin was measured using MitoSOX and H₂DCFDA experiments. The anti-arthritic efficacy of Gintonin was examined by analyzing the expression levels of inflammatory mediators using RT-PCR, western blot, and ELISA. The phosphorylation of mitogen-activated protein kinase (MAPK) pathways and translocation of nuclear factor kappa B (NF-κB)/p65 into the nucleus were also analyzed using western blot, ELISA, and immunocytochemistry. Collagen-induced arthritis (CIA) mice model was used. Mice were orally administered with Gintonin (25, 50, and 100 mg/kg) every 2 days for 45 days. The body weight, arthritis score, squeaking score, and paw volume were measured as the behavioral parameters. After sacrifice, H&E and safranin-O staining were performed for histological analysis. Results: Gintonin significantly inhibited the expression of inflammatory intermediates. Gintonin prevented NF-κB/p65 from moving into the nucleus through the JNK and ERK MAPK phosphorylation in FLS cells. Moreover, Gintonin suppressed the symptoms of arthritis in the CIA mice model. Conclusion: As a result, the antioxidant and anti-inflammatory effects of Gintonin were demonstrated, and ultimately the anti-arthritic effect was proved. Collectively, Gintonin has a great potential as a therapeutic agent for arthritis treatment.

• 한국동물생명공학회지
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• 제38권3호
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• pp.109-120
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• 2023

Background: Pluripotent stem cells (PSCs) including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) offer the immense therapeutic potential in stem cell-based therapy of degenerative disorders. However, clinical trials of human ESCs cause heavy ethical concerns. With the derivation of iPSCs established by reprogramming from adult somatic cells through the transgenic expression of transcription factors, this problems would be able to overcome. In the present study, we tried to differentiate porcine iPSCs (piPSCs) into endothelial cells (ECs) for stem cell-based therapy of vascular diseases. Methods: piPSCs (OSKMNL) were induced to differentiation into ECs in four differentiation media (APEL-2, APEL-2 + 50 ng/mL of VEGF, EBM-2, EBM-2 + 50 ng/mL of VEGF) on cultured plates coated with matrigel^® (1:40 dilution with DMEM/F-12 medium) for 8 days. Differentiation efficiency of these cells were exanimated using qRT-PCR, Immunocytochemistry, Western blotting and FACS. Results: As results, expressions of pluripotency-associated markers (OCT-3/4, SOX2 and NANOG) were higher observed in all porcine differentiated cells derived from piPSCs (OSKMNL) cultured in four differentiation media than piPSCs as the control, whereas endothelial-associated marker (CD-31) in the differentiated cells was not expressed. Conclusions: It can be seen that piPSCs (OSKMNL) were not suitable to differentiate into ECs in the four differentiation media unlike porcine epiblast stem cells (pEpiSCs). Therefore, it would be required to establish a suitable PSCs for differentiating into ECs for the treatment of cardiovascular diseases.

• 한국발생생물학회지:발생과생식
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• 제12권1호
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• pp.87-95
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• 2008

만능성 인간 배아줄기세포로부터 확립된 신경줄기세포 또는 신경전구세포는 퇴행성 신경질환 세포치료제로 이용될 수 있는 다양한 종류의 신경세포로 분화 유도될 수 있다. 하지만, 인간 배아줄기세포로부터 신경세포를 생산하기 위한 기술은 아직 많은 장애를 가지고 있다. 인간 배아줄기세포 유래 신경전구세포에서 특징적으로 나타나는 신경관 유사로제트에 대한 이해는 인간 배아줄기세포 신경 분화의 효율을 높이는데 유용한 정보를 제공할 것으로 사료된다. 일반적으로 신경로제트(neural rosette)는 분화 중인 배아체를 부착 배양함으로써 유도하지만, 이 방법은 시간이 걸리고 복잡하다는 단점이 있다. 본 연구에서는 신경로제트가 부착배양을 하지 않고 부유배양으로 형성될 수 있는지 조사하였다. 우선적으로, 배아체 형성 및 신경분화에 인간 배아줄기세포 클럼프(clump) 크기가 영향을 주는지를 조사하였고, 사방 $500\;{\mu}m$ 크기의 인간 배아줄기세포 클럼프가 신경 분화 유도에 가장 효과적임을 확인하였다. 로제트 형성을 유도하기 위해, 사방 $500\;{\mu}m$ 크기의 인간 배아줄기세포 클럼프를 1주일 동안 EB 배양배지에 부유 배양함으로써 균일한 크기의 배아체를 얻은 후, NES 배양 배지에서 부가적으로 $1{\sim}2$주 동안 계속 부유 배양한 결과, $7{\sim}10$일 사이에 신경관 유사 로제트가 형성됨을 확인하였다. 로제트 형성 세포의 신경전구세포로서 특성은 RT-PCR과 면역형광염색법을 이용한 신경전구세포 특이적 마커(vimentivi, nestin, MSI1, MSI2, Sox1, Tuj1) 발현을 통해 확인하였다. 또한, 성장인자를 제외한 NES 배양 배지에서 신경로제트를 $2{\sim}6$주 동안 지속적으로 배양하면 성숙 신경세포로의 말단 분화가 유도됨을 확인하였다. 신경세포 특이적 마커(Tuj1, MAP2, GABA)와 신경아교 특이적 마커($S100{\beta}$, GFAP)는 $2{\sim}3$주 또는 4주 후에 각각 발현이 유도됨을 확인하였고, 희소 돌기아교 특이적 마커(O1과 CNPase)는 $5{\sim}6$주 후에 발현이 증가함을 확인하였다. 본 연구결과는 신경로제트가 부유 배양시스템에서 성공적으로 형성됨을 보여주고 있으며, 이는 인간 배아줄기세포의 신경 분화를 이해하고, 신경전구세포 유도 과정을 단순화하는데 효과적으로 이용될 수 있을 것으로 사료된다.