• 대한임상검사과학회지
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• 제40권2호
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• pp.106-112
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• 2008

Bone marrow derived mesenchymal stem cells (BMSCs) are largely studied for their potential clinical use. But it is hard to get enough number of those cells for clinical trials and give serious pain to the patients. Adipose tissue is derived from the embryonic mesenchyme and contains a stroma that is easily isolated with large amount. This cell population (adipose derived stem cells: ADSCs) can be isolated from human lipoaspirates and like MSCs, differentiate toward the osteogenic, adipogenic, myogenic and chondrogenic lineages. To confirm whether adipose tissue contains stem cells, the ADSCs extracted from omental or subcutaneous fat tissue were expanded during third to fifth passages. The phenotype of the ADSCs was identified by the conventional cell surface markers using flow cytometry: positive for CD29 and CD44, but negative for CD34, CD45, CD117 and HLA-DR that similar to those observed on BMSCs. The ADSCs were able to differentiate into the osteoblast or adipocytes with induction media. Finally, ADACs expressed multiple CD marker antigens similar to those observed on BMSCs and differentiated into osteoblast, adipocyte. With this, human adipotissue contains multipotent cells and may represent an alternative stem cell source to bone marrow-derived MSCs.

• Clinical and Experimental Reproductive Medicine
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• 제42권2호
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• pp.33-44
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• 2015

The generation of artificial gametes is a real challenge for the scientific community today. In vitro development of human eggs and sperm will pave the way for the understanding of the complex process of human gametogenesis and will provide with human gametes for the study of infertility and the onset of some inherited disorders. However, the great promise of artificial gametes resides in their future application on reproductive treatments for all these people wishing to have genetically related children and for which gamete donation is now their unique option of parenthood. This is the case of infertile patients devoid of suitable gametes, same sex couples, singles and those fertile couples in a high risk of transmitting serious diseases to their progeny. In the search of the best method to obtain artificial gametes, many researchers have successfully obtained human germ cell-like cells from stem cells at different stages of differentiation. In the near future, this field will evolve to new methods providing not only viable but also functional and safe artificial germ cells. These artificial sperm and eggs should be able to recapitulate all the genetic and epigenetic processes needed for the correct gametogenesis, fertilization and embryogenesis leading to the birth of a healthy and fertile newborn.

• The Korean Journal of Physiology and Pharmacology
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• 제24권6호
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• pp.441-452
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• 2020

In vivo animal models are limited in their ability to mimic the extremely complex systems of the human body, and there is increasing disquiet about the ethics of animal research. Many authorities in different geographical areas are considering implementing a ban on animal testing, including testing for cosmetics and pharmaceuticals. Therefore, there is a need for research into systems that can replicate the responses of laboratory animals and simulate environments similar to the human body in a laboratory. An in vitro two-dimensional cell culture model is widely used, because such a system is relatively inexpensive, easy to implement, and can gather considerable amounts of reference data. However, these models lack a real physiological extracellular environment. Recent advances in stem cell biology, tissue engineering, and microfabrication techniques have facilitated the development of various 3D cell culture models. These include multicellular spheroids, organoids, and organs-on-chips, each of which has its own advantages and limitations. Organoids are organ-specific cell clusters created by aggregating cells derived from pluripotent, adult, and cancer stem cells. Patient-derived organoids can be used as models of human disease in a culture dish. Biomimetic organ chips are models that replicate the physiological and mechanical functions of human organs. Many organoids and organ-on-a-chips have been developed for drug screening and testing, so competition for patents between countries is also intensifying. We analyzed the scientific and technological trends underlying these cutting-edge models, which are developed for use as non-animal models for testing safety and efficacy at the nonclinical stages of drug development.

• International Journal of Industrial Entomology and Biomaterials
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• 제4권1호
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• pp.51-56
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• 2002

A recombinant transfer vector pBacSCF was constructed by inserting huamn stem cell factor (hSCF) cDNA into plasmid pBacPAK8. BmN cells were co-transfected with modified Bombyx mori, nuclear polyhedrosis virus (BmBacPAK) DNA and the recmbinant transfer vector to construct a recombinant baculovirus containing hSCE gene. DNA dot blotting and RNA dot blotting demonstrated that the hSCE gene was contained in the recombinant virus and transcribed. The recombinant baculovirus was infectious to BmN cells and to silkworm. SDS-PAGE analysis showed a specific band of expressed product in the extract of infected cells and in the heamolymph of infected larvae. Bioactivity of the recombinant hSCE was determined with W-1 cell line and MTT colorimetric method in synergy with interlukin-3 (IL-3). These results revealed that the hSCF gene was over-expressed in cultured cells and lavae of silkworm.

• 대한임상검사과학회지
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• 제37권1호
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• pp.41-46
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• 2005

It is known that mast cells (MCs) are increased in H. pylori-infected gastritis and its increase is mediated by stem cell factor (c-kit ligand). To determine the mechanism of mast cell recruitment and activation by stem cell factor, weinvestigated the expression of stem cell factor receptor (c-kit) in H. pylori-positive and -negative gastric mucosa. Biopsy specimens from 16 H. pylori-negative and 20 positive subjects were examined. H. pylori infection in gastric mucosa was examined by the Warthin-Starry method. MC and c-kit were identified by immunohistochemisty, using a monoclonal antihuman MC tryptase antibody and a polyclonal anti-human c-kit antibody. Densities of MC and c-kit positive cell were measured by a computerized image analysis system. MCs were detected in the lamina propria of both H. pylori-positive and -negative gastric mucosa. Densities of MC and c-kit positive cell were significantly greater in H. pylori-positive than -negative subjects. c-kit was located on the surface of MCs. These results indicate that stem cell factors may be one of the factors involved in mast cell increase and that they activate mast cells by binding with c-kit.

• Molecules and Cells
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• 제41권7호
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• pp.613-621
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• 2018

The capacity of differentiation of human pluripotent stem cells (hPSCs), which include both embryonic stem cells and induced pluripotent stem cells, into cardiomyocytes (CMs) in vitro provides an unlimited resource for human CMs for a wide range of applications such as cell based cardiac repair, cardiac drug toxicology screening, and human cardiac disease modeling. However, their applicability is significantly limited by immature phenotypes. It has been well known that currently available CMs derived from hPSCs (hPSC-CMs) represent immature embryonic or fetal stage CMs and are functionally and structurally different from mature human CMs. To overcome this critical issue, several new approaches aiming to generate more mature hPSC-CMs have been developed. This review describes recent approaches to generate more mature hPSC-CMs including their scientific principles, advantages, and limitations.

• Clinical and Experimental Pediatrics
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• 제57권3호
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• pp.110-116
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• 2014

Cord blood (CB) has been used as an important and ethical source for hematopoietic stem cell transplantation (SCT) as well as cell therapy by manufacturing mesenchymal stem cell, induced pleuripotential stem cell or just isolating mononuclear cell from CB. Recently, the application of cell-based therapy using CB has expanded its clinical utility, particularly, by using autologous CB in children with refractory diseases. For these purposes, CB has been stored worldwide since mid-1990. In this review, I would like to briefly present the historical development of clinical uses of CB in the fields of SCT and cell therapy, particularly to review the experiences in Korea. Furthermore, I would touch the recent banking status of CB.

• 보건행정학회지
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• 제23권4호
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• pp.314-325
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• 2013

Background: Stem cell research competition is accelerating globally since President Obama signed an executive order, repealing Bush-era policy that limited use of federal tax dollars for embryonic stem cell research. Methods: In this paper, we conducted a comparative analysis of stem cell research policy changes in three countries, including the Human Fertilisation Embryology Act (HFEA) of UK, executive order 13,505 (removing barriers to responsible scientific research involving human stem cells) of USA, and Bioethics and Safety Act of South Korea. Debates on stem cell research are based on conflicts of fundamental beliefs that exist in the supporting and opposing coalitions. We compared regional characteristics of the advocacy coalitions in three countries and presented various factors that might be related to the policy changes. Results: The UK government, parliament, and the HFEA have sought expert consultations and public opinions to establish guidelines. UK has made social consensus through continued discussion for a long time. US President's veto power was one strongest factors influencing policy. South Korean policy was influenced by public opinion and policy brokers. Also, South Korea has not made social consensus. UK had a strong leadership and strong adjustment of coalitions but US and South Korea had not. Dr. Hwang's scandal has had one of the greatest impacts on policy decision in South Korea. Conclusion: The power of public opinion was critical in all three countries. In particular, the influence of public opinion was noticeable in South Korea. Also it turned out that in US and South Korea, the presence of a policy broker who could pursue his or her goals was the most powerful factor among the advocacy coalition factors.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.273.2-274
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• 2002

Human epidermal keratinocytes consist of stem cells. transit amplifying cells. and postmitotic differentiating cells. Among them, stem cells playa critical role in cell renewal. wound healing. and neoplasia. However. till now, specific markers of human epidermal keratinocytes are not clearly defined. In the present study. we separated putative stem cells from other cells using fluorescence activated cell sorting (FACS). based on differences in a6-integrin and CD71 expression. (omitted)

• Archives of Plastic Surgery
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• 제32권3호
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• pp.343-346
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• 2005

It has been established that a graft of fibroblasts is able to improve wound healing. However, there has been no research on the effect of a graft of bone marrow stromal cells on wound healing. The wound healing process requires cell proliferation and production of extracellular matrix and various growth factors. The purpose of this study was to compare the abilities of human fibroblasts and bone marrow stromal cells, which contains mesenchymal stem cells, to proliferate and to produce collagen. Human bone marrow stromal cells and fibroblasts were isolated from bone marrow and dermis of the same patients and grown in culture respectively. Cell proliferation and production of type I collagen by human bone marrow stromal cells and dermal fibroblasts were examined by MTT method and by ELISA of cell culture media on day 1, 3, and 5 days post-incubating. The human bone marrow stromal cells showed 11-17% higher cell proliferation than fibroblasts at each time interval. The levels of type I collagen in the human bone marrow stromal cell group was also significantly higher than those in the fibroblast group. The results indicate that the grafts of human bone marrow stromal cells can show more promising effect than that of fibroblasts for healing of chronic wounds.