• The Korean Journal of Zoology
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• v.24 no.4
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• pp.189-200
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• 1981

Drastic alterations in myogenesis could be induced by ultraviolet irradiation of the myogenic cells derived from 12 day old chick embryo skeletal muscle. The effects of irradiation on various aspects, including cell division, transformation to myotubes, and morphology of myoblasts and myotubes, were examined. Irradiated cells were smaller in size, and only few cells transformed resulting in smaller size of myotubes with a narrow width. Both the inhibiting actions to cell division and to fusion were more striking when irradiated at earlier stages after plating. As well, cell division and fusion were inhibited more effectively with increasing UV dose and excessive amount caused cell death. A lowering cell density was thought to account for the decrease in myogenesis and possible reasons for the decrease in the capacity for fusion were discussed in view of the results presented in this report and of the findings from other laboratories.

• Journal of Gifted/Talented Education
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• v.13 no.4
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• pp.119-140
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• 2003

The purpose of this study is to examine the dispute over creativity domain at schools in Korea. In other words, this study is to examine the creativity domain among all subjects, a group of high level performance, and a group of low level performance in creativity. Based on ability-differentiation hypothesis, correlation among 4 domains, correlation between divergent thinking variables of domain-generality and 4 domains of domain-speciality, and multiple linear regression have been computed. The results are opposed to the hypothesis. The group of low level performance is related to domain-speciality. The group of high level performance, however, has relationships neither domain-generality nor domain-speciality. Instead of differentiation between domain-generality and domain-speciality, the results support the domain-complementarity.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.283-292
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• 2009

Objective: Human embryonic stem cells (hESCs) can proliferate indefinitely and differentiate into all kinds of cell types in vitro. Therefore, hESCs can be used as a cell source for cell-based therapy. Transduction of foreign genes to hESCs could be useful for tracing differentiation processes of hESCs and elucidation of gene function. Thus, we tried to introduce enhanced green fluorescent protein (eGFP) gene to hESCs, XX and XY cell lines in this study. Methods: Lentivirus containing eGFP was packaged in 293T cells and applied to hESCs to transduce eGFP. Expression of transduced eGFP was evaluated under the fluorescence microscope and eGFP positive population was analyzed by FACS. Expression of undifferentiation state markers such as Oct4, Nanog, SSEA4 and Tra-1-81 was examined by RT-PCR and/or immunofluorescence in eGFP-hESCs after transduction. In addition, the ability of eGFP-hESCs to form embryoid bodies (EBs) was tested. Results: eGFP was successfully transduced to hESCs by lentivirus. eGFP expression was stably maintained up to more than 40 passages. eGFP-hESCs retained expression patterns of undifferentiation state markers after transduction. Interestingly, disappearance of transduced eGFP was notably observed during spontaneous differentiation of eGFP-hESCs. Conclusion: We established eGFP expressing hESC lines using lentivirus and showed the maintenance of undifferentiation characteristics of these eGFP-hESCs. This reporter-containing hESCs could be useful for tracing the processes of differentiation of hESCs and other studies.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.4
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• pp.376-384
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• 2009

Purpose: The purpose of this study was to evaluate the response of osteoblast-like cells to Ca-P coated surface obtained via Ion beam-assisted deposition (IBAD) method and Sol-Gel process on anodized surface by cellular proliferation and differentiation. Material and methods: The surface of a commercially pure titanium (Grade IV) discs with dimension of 10mm diameter and 2 mm thickness was modified by anodic oxidation under a constant voltage of 300 V. The experimental groups were coated with Ca-P by the IBAD method and Sol-Gel process on anodized surface. The surface roughness (Ra) of specimens was measured by optical interferometer and each surface was examined by SEM. To evaluate cell response, MG63 cells were cultured and cell proliferation, ALP activity and the ability of cell differentiation were examined. Also, cell morphology was examined by SEM. The significant of each group was verified by Kruskal-Wallis Test ($\alpha$=.05). Results: The Ra value of Ca-P coated surface by IBAD method was significantly higher than Ca-P coated surface by Sol-gel process (P < .05). The level of cell proliferation and ALP activity was higher in Ca-P coated surface by IBAD method (P<.05). The expression of ALP showed higher level expression in Ca-P coated surface by IBAD method. Cells grown on Ca-P coated surface by IBAD method were uniformly distributed and developed a very close layer. Conclusion: These experiments showed better performances of Ca-P coated surface by IBAD method with respect to Ca-P coated surface by Sol-gel process. Ca-P coated surface by IBAD method appear to give rise more mature osteoblast characteristics and might result in increased bone growth and bone-implant contact.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.117-117
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• 2003

체외에서 한우 난포란의 감수분열과 배발달 능력의 획득에는 단백질 합성이 수반되어야 한다. 그러나 이러한 변화와 관련된 연구 보고는 거의 전무한 실정이다. 본 실험은 난자의 핵성숙과 관련된 세포질내 단백질 변화를 파악하기 위하여, 체외성숙 시간에 다른 배발달율과 세포질내 단백질을 비교하여 배발달능력 획득과 관련 있는 단백질을 규명하고자 실시하였다. 한우 난소에서 2-8mm의 가시난포로부터 난포란을 회수하였다. 회수된 난포란은 10% FBS와 호르몬이 첨가된 TCM199 용액에서 18시간 또는 24시간 체외성숙을 실시하였다. 난자 세포질내 단백질 변화는 2D gel electrophoresis를 이용하였고, 유의적인 변화를 나타낸 spot은 peptide mass fingerprinting을 통하여 단백질 동정을 실시하였다. 체외수정은 fer-TALP 용액을, 체외배양은 CR1aa 용액을 배양 3일째까지는 0.3% BSA, 그 이후에는 10% FBS와 난관상피세포를 첨가하여 사용하였다. 통계분석은 t-test를 이용하였다. 난자의 세포질에 대한 이차원전기영동 결과 29개의 단백질 spot들을 확인하였다. 한편 체외성숙 18시간째에 PB가 출현된 난자는 PB가 출현되지 않은 난자에 비하여 15개의 spot에서 유의적인 변화를 나타냈다. 이들 중 4개의 단백질 spot은 낮았고, 11개 spot의 수준은 높은 경향이었다. 체외성숙 18시간째와 24시간째의 배발달율을 조사한 결과 18시간째에서 유의적으로 높은 배반포 발달율을 나타냈다. 그리고 체외성숙 18시간과 24시간째 난자의 세포질내 단백질 spot들의 변화를 비교한 결과 PB가 출현된 난자 세포질에서 단백질의 변화와 유사한 경향이었다. 그러나 2개의 단백질 spot은 상반된 경향을 나타냈다. 따라서 본 실험에서 난자의 핵성숙과 관련 있는 15개의 spot을 확인하였고, 이들 단백질 spot중에서 2개가 배발달 능력과 관련이 있을 것으로 사료된다.보다는 육질등급에 많은 영향을 받는 것으로 판단된다. 한편 육질 1등급에서 배발달율이 낮은 이유는 육질 향상을 목적으로 암소를 비육 하는 경우 발생하는 번식장애와 밀접한 관계가 있는 것으로 사료된다.각각 가장 높았다. 배양 8일째 배반포의 세포수에 있어서 총세포수와 TE 세포수는 차이가 없었으나, ICM 세포수가 l0mg 첨가군에서 가장 높았다. 본 실험 결과에서 체외성숙 배지에 NEAA와 EAA 첨가가 배발달율에는 효과가 없었지만, 첨가농도의 증가에 따라 ICM 세포수가 증가하였다. 한편 체외성숙 배지에 LAH 첨가는 첨가 농도가 높을수록 배발달율은 낮았지만 ICM 세포수는 증가하였다.에 Csk가 관여하고 있음을 알 수 있다. 결론적으로 성적 성숙에 따른 생쥐 정소 내 Src-Csk loop의 발현과 Src kinase 활성의 변동은 정소 내 간충조직, 세정관 상피의 증식 및 기능적 분화 과정을 매개하는 생리적 활성분자 수용체 하위의 신호전달 과정에 Src-Csk loop에 의한 조절가능성을 확인할 수 있었다.rugrene의 향기성분이 주요 성분군으로 확인되었다. 2. 생강나무에서 생강의 향기를 발산하는 성분으로는 $\beta$-myrcene, o-terpinolene, phellandrone, ι-limonene, $\beta$-eudesmol, $\delta$-cadinone, elemol, trans-caryophyllene으로 동정되었으며 그 중에서도 phellandrene, $\beta$-eudesmol이 주된 역할을 하는 성분으로 확인하였다. 유의적인 관련성이 나타났고, 복부 비만의 지표인 허리엉덩이둘레비는 GPT, alkaline phosphatase, 공복시 혈당 및 MCV 등 다양한 건강지표와 관련성을 나타내어 향후 비만에 있어 다양한 혈액 성상의 변화 및 역할규명에 대한 연구가 이루어져야 할 것으로 본다.hat

• Development and Reproduction
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• v.11 no.3
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• pp.219-226
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• 2007

This study was conducted to identify optimistic primordial germ cells'(PGCs) migration activity using heat activated busulfan treatment for the increasing germline chimerism. Donar PGCs viability tests of important conditions for useful germ line chimerism indicated approximately $70{\sim}80%$ viability was time dependent. Transplantation experiments of PGCs into recipient embryos after busulfun treatment, showed the treatment group having 23.5% viability. By comparison, the control group showed 4.8% viability. The 96 hour treatment group and the 118 hour treatment group of the cultured PGCs showed high migration activity. Generally, the transplantation method would consider morphological and physiological characteristics before transplantation. In the present study, the effect of busulfan on migration activity showed viability highest at 53.4% after 48-hour incubation time. However, a previous study showed the best condition for transplantation time to be prior to the 48-hour incubation period, when the chicken embryo does not yet have a developed blood vessel system. In conclusion, an important condition for the production of a transgenic chicken is that most donor PGCs migrate into the recipient embryo without any inhibitory factors. The present results suggest, perhaps by using this modified method of transplantation, it can produce a more efficient chimeric germ line, transgenic chicken.

• Journal of Life Science
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• v.29 no.4
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• pp.499-508
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• 2019

Cancer stem cells (CSCs), which are primarily responsible for metastasis and recurrence, have self-renewal, differentiation, therapeutic resistance, and tumor formation abilities. Numerous studies have demonstrated the signaling pathways essential for the acquisition and maintenance of CSC characteristics, such as WNT/${\beta}$-catenin, Hedgehog, Notch, B lymphoma Mo-MLV insertion region 1 homolog (BMI1), Bone morphogenetic protein (BMP), and TGF-${\beta}$ signals. However, few therapeutic strategies have been developed that can selectively eliminate CSCs. Recently, neutralizing antibodies against Cytotoxic T-lymphocyte associated protein 4 (CTLA-4) and Programmed cell death protein 1 (PD-1)/Programmed death-ligand 1 (PD-L1), immune checkpoint inhibitors (ICIs), have shown promising outcomes in clinical trials of melanoma, lung cancer, and pancreatic cancer, as well as in hematologic malignancies. ICIs are considered to outperform conventional anticancer drugs by maintaining long-lasting anti-cancer effects, with less severe side effects. Several studies reported that ICIs successfully blocked CSC properties in head and neck squamous carcinomas, melanomas, and breast cancer. Together, these findings suggest that novel and effective anticancer therapeutic modalities using ICIs for selective elimination of CSCs may be developed in the near future. In this review, we highlight the origin and characteristics of CSCs, together with critical signaling pathways. We also describe progress in ICI-mediated anticancer treatment to date and present perspectives on the development of CSC-targeting ICIs.

• Radiation Oncology Journal
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• v.13 no.1
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• pp.1-7
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• 1995

Purpose : To evaluate the efficacy of radiotherapy for the low-grade astrocy-tomas and confirm the variables influencing treatment results. Materials and Methods : Forty-six patients with low-grade astrocytoma received radiotherapy after surgical removal (36 patients) or biopsy (10 patients) from 1979 to 1990. Twenty patients had grade I histology and 26 had grade II. External radiotherapy was done by conventional schedule with the total dose of 45 to 60 Gy (median: 54 Gy). The median follow-up period was 5 years. Results : The 2- and 5-year survival rates were $80\%$ and $72\%$, respectively and the 2- and 5-year progression-free survival was $75\%$ and $63\%$, respectively. The survival was influenced significantly by the histologic grade, the histologic type, and performance status. Major complication was not found. Conclusion: In spite of good survival, the local failure was still the major problem. Age and the extent of surgery as well as three favorable factors should be considered in the future treatments.

• Development and Reproduction
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• v.15 no.4
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• pp.281-289
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• 2011

The objective of this study was to investigate the effective cryoprotectants for the cryopreservation of porcine mesenechymal stem cells (pMSCs). In order to understand the effectiveness of various cryoprotectants on pMSCs, we studied the most commonly used cryoprotectants; dimethyl sulfoxide (DMSO), ethylene glycol (EG), DMSO and EG. pMSCs were isolated from bone marrow matrix of piglet (2 month) and characterized by alkaline phopshatase (AP) activity, colony forming, and differentiation to adipocyte. In slow cooling cryopreservation, the pMSCs were exposed to cell medium containing Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% DMSO, 1.5M EG and 5% DMSO/0.75M EG, respectively, and freezed to $-1^{\circ}C$/min from $25^{\circ}C$ up to $-80^{\circ}C$ in a cryo-container. The proportion of viable cells and the growing rates in fresh pMSCs were significantly (P<0.05) higher than those of other groups, but did not differ between the cryopreserved groups. The expression of Sox-2 and Nanog gene was increased by extending culture time in cryopreserved groups. The expression of Bax gene in cryopreserved groups was similar with fresh pMSCs. Moreover, the gene expression of adipocyte-specific marker as well as chondrogenic/osteogenic factors in cryopreserved groups was similarly to fresh pMSCs. Taken together, our results suggested that all these cryoprotectants of 10% DMSO, 1.5M EG and 5% DMSO/0.75M EG could be used for cryopreservation of the pMSCs.

• Development and Reproduction
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• v.11 no.1
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• pp.1-11
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• 2007

Specific endometrial preparation should occur during periimplantation period. That is a progress of serial differentiation and is absolute in implantation of embryo and successful pregnancy. Remodeling of tissues shown during embryogenesis is regulated by various factors including extracellular matrix (ECM). Marked changes during pregnancy are including embryo migration, decidual response, and differentiation of placenta in placental animals including human. These changes to successful implantation in embryo and uterus have to prepare the competence for attachment of embryo and uterus, and invasion defense of uterus. During these changes, ECM dramatically changes for maintaining the uterine and embryonic functions. The major component of most connective tissue is collagens. It is very complex and hard to explore the mechanisms for ECM modulation. Recently using high throughput methodology, PCR-select cDNA subtraction method, microarray, many candidate genes have been identified. Steroid hormones have fundamental role in implantation and maintenance of pregnancy. Dermatopontin, a regulator of collagen accumulation, is regulated spatio-temporally in the uterus by primarily progesterone through progesterone receptors at the time of implantation. Modulation of extracellular matrix is critically regulated by cascade of gene net-works which are regulated by cascade of sex steroid hormones. Pathological regulation of uterine extracellular matrix reported in diabetic patients. To know the extracellular modulation is essential to understanding implantation, feto-placental development and overcome the paths involved in female reproduction. Though ECM composed with very various components and it is complex, the present review focused on the fate of collagens during periimplantation period.