• BMB Reports
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• v.42 no.2
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• pp.72-80
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• 2009

In mammals, major progress has recently been made with the dissection of early embryonic cell specification, the isolation of stem cells from early embryos, and the production of embryonic-like stem cells from adult cells. These studies have overcome long-standing species barriers for stem cell isolation, have revealed a deeper than expected similarity of embryo cell types across species, and have led to a better understanding of the lineage identities of embryo-derived stem cells, most notably of mouse and human embryonic stem (ES) cells. Thus, it has now become possible to propose a species-overarching classification of embryo stem cells, which are defined here as pre- to early post-implantation conceptus-derived stem cell types that maintain embryonic lineage identities in vitro. The present article gives an overview of these cells and discusses their relationships with each other and the conceptus. Consequently, it is debated whether further embryo stem cell types await isolation, and the study of the earliest extraembryonically committed stem cells is identified as a promising new research field.

• Journal of Embryo Transfer
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• v.27 no.3
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• pp.189-192
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• 2012

Although embryonic stem cells (ESCs) or ES-like cells are reported from many mammalian species other than the mouse, the culture system for murine ESCs may not be suitable to the other species. Previously many other research groups have modified either human or mouse ESC culture systems for bovine ESC culture. In this study, we compared three different culture mediums consisting of DMEM, ${\alpha}$-MEM or KnockOut$^{TM}$-DMEM (KO), which are modified from human or mouse ESC culture system, for the generation of bovine ESCs. In this study, some pre-requisite events which are important for establishment and long-term propagation of ESCs such as inner cell mass (ICM) attachment on feeder cells, primary colony formation and sustainability after passaging. Once the ICM clumps attached on feeder cells, this was designated as passage 0. In regards to the rate of ICM attachment, ${\alpha}$-MEM was superior to the other systems. For primary colony formation, there was no difference between DMEM and ${\alpha}$-MEM whereas KO showed lower formation rate than the other groups. For passaging, the colonies were split into 2~4 pieces and passed every 5~6 days. From passage 1 to passage 3, DMEM system seemed to be appropriate for maintaining putative bovine ESCs. On the other hand, ${\alpha}$-MEM tended to be more suitable after passage 6. Although ${\alpha}$-MEM support to maintain a ES-like cell progenies to passage 15, all three culture systems which are modified from human or mouse ESC culture media failed to retain the propagation and long-term culture of putative bovine ESCs. Our findings imply that more optimized alternative culture system is required for establishing bovine ESC lines.

• Journal of Convergence Korean Medicine
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• v.5 no.1
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• pp.55-60
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• 2023

Objectives: This study was performed to investigate the effect of TJGB on the liver of high-fat diet (HFD)-fed mice and the cell viability of HepG2 cells. Methods: After a week adaptation, 8-week-old C57BL/6N mice were fed with a 45% HFD or normal diet for 3 weeks. For the next 9 weeks, the mice were divided into 6 groups: normal diet group; HFD group; HFD plus orlistat group; HFD plus Ephedra sinica Stapf (ES) group; HFD plus low dose of TJGB group; HFD plus high dose of TJGB group. To estimate the effect of TJGB in the liver of HFD-fed mice, the protein expressions of phospho-acetyl-CoA carboxylase (p-ACC) and liver X Receptor (LXR) were determined by Western blot assay. The cell viability of ES and TJG was also evaluated in HepG2 cells. Results: The administration of TJGB had little effect on the protein expressions of p-ACC and LXR in the liver of HFD-fed mice. And the cytotoxicity was showed above 7.8 ㎍/mL in HepG2 cells. Conclusion: Further research is needed to evaluate the mechanism of TJGB on hepatic steatosis and cytotoxicity in HepG2 cells.

• Korean Journal of Animal Reproduction
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• v.25 no.1
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• pp.71-77
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• 2001

This experiment was designed to improve the production efficiency of germ-line chimeric mice from phospholipase C (PLC)-$\beta$3 or peroxiredoxin (Prx) E -targeted ($\Delta$) ES cells by the investigating the manipulation conditions and characteristics of Jl ES cells. Four targeting clones were isolated to investigate the karyotypical and morphological stability prior to injection. All clones ($\Delta$PLC$\beta$-3 C3, $\Delta$Prx II C3, C10 and I5) showed more than 80% euploidism, however, most of $\Delta$PLC$\beta$-3 C3 clones were extensively differentiated compared to the other clones. Nine of 13 $\Delta$Prx II chimeras appeared to have at least 80% chimerism, whereas $\Delta$PLC$\beta$-3 C3 chimeras had 20% chimerism at most. Therefore, the morphological stability of ES cells under stable euploidism might mainly affect the production rate of high-coat chimeric mice. To increase the collection rate of injectable blastocysts (IBs), 5 to 10 week -aged C57BL/6J female mice were sacrificed at 3.5 days post-coitum. Ten week-aged mice were the most optimal IB donors by showing the highest collection rate (2.94/mouse) of injectable blastocysts without increase of non-injectable embryos (0.29/mouse). Foster mothers might be another factor because ICR x C57BL/6J F1 foster mother showed more increased productivity in litter size (2.8 vs. 5.6) and chimera (0 vs. 35.3%) than those of ICR foster mothers. In conclusion, the efficient production of germ-line chimeras mainly depends on the maintenance of ES cell morphology during targeting procedure, and the establishment of manipulation conditions might be a key point to maximize it.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.1
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• pp.1-9
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• 2012

Because the average human life span has recently increased, the number of patients who are diagnosed with neurodegenerative diseases has escalated. Recent advances in stem cell research have given us access to unlimited numbers of multi-potent or pluripotent cells for screening for new drugs for neurodegenerative diseases. Neural stem cells (NSCs) are a good model with which to screen effective drugs that increase neurogenesis. Recent technologies for human embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) can provide human cells that harbour specific neurodegenerative disease. This article discusses the use of NSCs, ESCs and iPSCs for neurodegenerative drug screening and toxicity evaluation. In addition, we introduce drugs or natural products that are recently identified to affect the stem cell fate to generate neurons or glia.

• Physical Therapy Korea
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• v.13 no.2
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• pp.9-15
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• 2006

Skeletal muscle injury occurs frequently in sports medicine and is the most general form of injury followed by physical impact. There are growth factors which conduct proliferation, differentiation, and synthesis of myogenic prodromal cells and regulate vascular generation for the continued survival of myocytes. The purpose of the present study was to confirm the effects of electroacupuncture (EA) and electrical stimulation (ES) on muscle recovery processes according to vascular endothelial growth factor (VEGF) expression. Eighteen Sprague-Dawley rats were separated into 2 experimental groups and a controlled group. All animals had suffered from crush damage in the extensor digitorum longus for 30 seconds and were killed 1, 3, and 7 days after injury. 30 Hz and 1 mA impulsion for 15 minutes was applied to the EA experimental groups Zusanli (ST36) and Taichong (LR3) using electroacupuncture and the same stimulation was applied to the ES group using an electrical node. Hematoxyline-Eosin staining and VEGF immunohistochemistry were used to ascertain the resulting muscle recovery. There were few morphological differences between the EA and ES groups, and both groups were observed to have tendencies to decrease atrophy as time passed. In the controlled group, gradually diminishing atrophy could be observed, but their forms were mostly disheveled. There were few differences in VEGF expression between the EA and ES groups, and tendencies to have an increased quantity of VEGF with the lapse of time were observed in both groups. In the controlled group, a little VEGF expression could be observed merely 7 days after injury. In conclusion, EA and ES contributed to muscle recovery processes and could be used for the treatment of muscle injury.

• Parasites, Hosts and Diseases
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• v.53 no.4
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• pp.431-438
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• 2015

In Trichinella spiralis infection, type 2 helper T (Th2) cell-related and regulatory T ($T_{reg}$) cell-related immune responses are the most important immune events. In order to clarify which Toll-like receptors (TLRs) are closely associated with these responses, we analyzed the expression of mouse TLR genes in the small intestine and muscle tissue during T. spiralis infection. In addition, the expression of several chemokine- and cytokine-encoding genes, which are related to Th2 and $T_{reg}$ cell mediated immune responses, were analyzed in mouse embryonic fibroblasts (MEFs) isolated from myeloid differentiation factor 88 (MyD88)/TIR-associated proteins (TIRAP) and Toll receptor-associated activator of interferons (TRIF) adapter protein deficient and wild type (WT) mice. The results showed significantly increased TLR4 and TLR9 gene expression in the small intestine after 2 weeks of T. spiralis infection. In the muscle, TLR1, TLR2, TLR5, and TLR9 gene expression significantly increased after 4 weeks of infection. Only the expression of the TLR4 and TLR9 genes was significantly elevated in WT MEF cells after treatment with excretory-secretory (ES) proteins. Gene expression for Th2 chemokine genes were highly enhanced by ES proteins in WT MEF cells, while this elevation was slightly reduced in MyD88/$TIRAP^{-/-}$ MEF cells, and quite substantially decreased in $TRIF^{-/-}$ MEF cells. In contrast, IL-10 and $TGF-{\beta}$ expression levels were not elevated in MyD88/$TIRAP^{-/-}$ MEF cells. In conclusion, we suggest that TLR4 and TLR9 might be closely linked to Th2 cell and $T_{reg}$ cell mediated immune responses, although additional data are needed to convincingly prove this observation.

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.67-68
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• 2004

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2003.10a
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• pp.97-97
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• 2003

• 대한생식의학회:학술대회논문집
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• 2002.05a
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• pp.90-90
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• 2002