• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권6호
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• pp.588-593
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• 2008

There are increasing reports regarding regeneration of the defected tissues using tissue engineering technique. In this technique, multipotential stem cells are essential. There are many potential sources of adult stem cells, such as bone marrow, umbilical cord blood, fat, muscle, dental tissues and skin. Among them, skin is highly accessible and easily obtained with a minimum of donor site complications. Moreover, skin is an abundant adult stem cell sources and has the potential for self-replication and immune privilege. In this study, we isolated skin-derived precursor cells (SKPs) from the ear of adult miniature pigs. In these SKPs, the expression of transcriptional factors, Oct-4, Sox-2, and Nanog were detected by RT-PCR. In vitro osteogenesis and adipogenesis were observed at 3 weeks after transdifferentiations as assayed by positive von Kossa and Oil-red O staining, respectively. In addition, expression of osteocalcin and osteonectin in the osteogenic differentiation medium and $PPAR{\gamma}2$ and aP2 in the adipogenic differentiation medium were detected by RT-PCR. In vitro neurogenesis of porcine SKPs was observed during 24 and 72 hours after treatment of neurogenic differentiation medium. The results of this study suggest that SKPs demonstrate the properties of pluripotence or multipotence and multi-lineage differentiation. This indicates that autogenous SKPs are a reliable and useful source of adult stem cells for regenerative medicine.

• 성인간호학회지
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• 제21권3호
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• pp.269-280
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• 2009

Purpose: To examine the effect of back massage on immune response, symptom distress, and mood state of patients undergoing allogeneic hematopoietic stem cell transplantation (allogeneic HSCT). Methods: Subjects were thirty-seven patients undergoing sibling allogeneic HSCT (including 16 in the experimental group and 21 in the control group). Experimental subjects participated in an intervention group of back massage for 10 minutes, once a day and 5 times a week, from one week prior to the HSCT to the third week after the HSCT or a control group. A non-equivalent pretest-posttest design was used. t-test and Repeated measures ANOVA were used to examine group differences by using SAS. Results: No significant group differences were found in Immune response (CD4+, CD8+,CD19+, CD56+) and symptom distress. The experimental group had significantly less mood state (anxiety, confusion) than the control group. Conclusion: The back massage for the patients undergoing allogeneic HSCT may be effective in altering the anxiety and confusion during hematopoietic stem cell transplantation. However, this study did not provide evidence in improving immune response and symptom distress.

• BMB Reports
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• 제49권2호
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• pp.93-98
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• 2016

Germline stem cells (GSCs) are the best understood adult stem cell types in the nematode Caenorhabditis elegans, and have provided an important model system for studying stem cells and their cell fate in vivo, in mammals. In this review, we propose a mechanism that controls GSCs and their cell fate through selective activation, repression and mobilization of the specific mRNAs. This mechanism is acutely controlled by known signal transduction pathways (e.g., Notch signaling and Ras-ERK MAPK signaling pathways) and P granule (analogous to mammalian germ granule)-associated mRNA regulators (FBF-1, FBF-2, GLD-1, GLD-2, GLD-3, RNP-8 and IFE-1). Importantly, all regulators are highly conserved in many multi-cellular animals. Therefore, GSCs from a simple animal may provide broad insight into vertebrate stem cells (e.g., hematopoietic stem cells) and their cell fate specification.

• 대한치과교정학회지
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• 제42권6호
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• pp.307-317
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• 2012

Objective: The purpose of this study was to investigate the isolation and characterization of multipotent human periodontal ligament (PDL) stem cells and to assess their ability to differentiate into bone, cartilage, and adipose tissue. Methods: PDL stem cells were isolated from 7 extracted human premolar teeth. Human PDL cells were expanded in culture, stained using anti-CD29, -CD34, -CD44, and -STRO-1 antibodies, and sorted by fluorescent activated cell sorting (FACS). Gingival fibroblasts (GFs) served as a positive control. PDL stem cells and GFs were cultured using standard conditions conducive for osteogenic, chondrogenic, or adipogenic differentiation. Results: An average of $152.8{\pm}27.6$ colony-forming units was present at day 7 in cultures of PDL stem cells. At day 4, PDL stem cells exhibited a significant increase in proliferation (p < 0.05), reaching nearly double the proliferation rate of GFs. About $5.6{\pm}4.5%$ of cells in human PDL tissues were strongly STRO-1-positive. In osteogenic cultures, calcium nodules were observed by day 21 in PDL stem cells, which showed more intense calcium staining than GF cultures. In adipogenic cultures, both cell populations showed positive Oil Red O staining by day 21. Additionally, in chondrogenic cultures, PDL stem cells expressed collagen type II by day 21. Conclusions: The PDL contains multipotent stem cells that have the potential to differentiate into osteoblasts, chondrocytes, and adipocytes. This adult PDL stem cell population can be utilized as potential sources of PDL in tissue engineering applications.

• Molecules and Cells
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• 제25권4호
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• pp.487-493
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• 2008

HoxB4 has been shown to enhance hematopoietic engraftment by hematopoietic stem cells (HSC) from differentiating mouse embryonic stem cell (mESC) cultures. Here we examined the effect of ectopic expression of HoxB4 in differentiated human embryonic stem cells (hESCs). Stable HoxB4-expressing hESCs were established by lentiviral transduction, and the forced expression of HoxB4 did not affect stem cell features. HoxB4-expressing hESC-derived CD34+ cells generated higher numbers of erythroid and blast-like colonies than controls. The number of CD34+ cells increased but CD45+ and KDR+ cell numbers were not significantly affected. When the hESC derived CD34+ cells were transplanted into $NOD/SCID{\beta}2m-/-$ mice, the ectopic expression of HoxB4 did not alter their repopulating capacity. Our findings show that overexpression of HoxB4 in differentiating hESCs increases hematopoietic colony formation and hematopoietic cell formation in vitro, but does not affect in vivo repopulation in adult mice hosts.

• Journal of Korean Neurosurgical Society
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• 제38권2호
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• pp.121-125
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• 2005

Objective : Many recent reports have shown that the mature mammalian brain harbors multipotent stem cells, rendering the brain capable of generating new neurons and glia throughout life. Harvested stem cells from an adult rat are transplanted in order to evaluate the cell survival and differentiation. Methods : Using a percoll gradient with a high speed centrifugation method, we isolate neural stem/progenitor cells were isolated from the subventricular zone[SVZ] of a syngeneic adult Fisher 344 rats brain. For 14days expansion, the cultured cells comprised of a heterogeneous population with the majority of cells expressing nestin and/or GFAP. After expanding the SVZ cells in the presence of basic fibroblast growth factor-2, and transplanting then into the hippocampus of normal rats, the survival and differentiation of those cells were examined. For transplantation, the cultured cells were labeled with BrdU two days prior to use. In order to test their survival, the cells were transplanted into the dorsal hippocampus of normal adult Fisher 344 rats. Results : The preliminary data showed that at 7days after transplantation, BrdU+ transplanted cells were observed around the injection deposition sites. Immuno-fluorescent microscopy revealed that the cells co-expressed BrdU+ and neuronal marker ${\beta}$-tubulin III. Conclusion : The data demonstrate that the in vitro expanded SVZ cells can survive in a heterotypic environment and develop a neuronal phenotype in the neurogenic region. However more research will be needed to examine the longer survival time points and quantifying the differentiation in the transplanted cells in an injured brain environment.

• Biomaterials and Biomechanics in Bioengineering
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• 제2권2호
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• pp.61-69
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• 2015

Undifferentiated stem cells are being studied to obtain information on the therapeutic potential of isolates that are produced. Dental Pulp Stem Ccell (DPSC) may provide an abundant supply of highly proliferative, multipotent Mesenchymal Stem Cells (MSC), which are now known to be capable of regenerating a variety of human tissues including bone and other dental structures. Many factors influence DPSC quality and quantity, including the specific methods used to isolate, collect, concentrate, and store these isolates once they are removed. Ancillary factors, such as the choice of media, the selection of early versus late passage cells, and cryopreservation techniques may also influence the differentiation potential and proliferative capacity of DPSC isolates. This literature review concludes that due to the delicate nature of DPSC, more research is needed for dental researchers and clinicians to more fully explore the feasibility and potential for isolating and culturing DPSCs extracted from adult human teeth in order to provide more accurate and informed advice for this newly developing field of regenerative medicine.

• Reproductive and Developmental Biology
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• 제29권2호
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• pp.109-115
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• 2005

Hematopoietic stem cells (HSC) are multipotent cells that reside in the bone marrow and replenish all adult hematopoietic lineages throughoutthe lifetime. In this study, we analyzed the expression of receptors of $P2Y_{10}$, purinergic receptor families in murine hematopoietic stem cells, hematopoietic progenitor cells. In addition, the biological activity of $P2Y_{10}$ was investigated with B lymphocyte cell line, Ba/F3 in effect to cell growth and cell cycle. From the analysis of expression in hematopoieticstem cell. and progenitor with RT-PCR, $P2Y_{10}$ was strongly expressed in murine hematopoieticstem cells (c-kit+ Sca-l+ Lin-) and progenitor cell population, such as c-kit- Sca-l+ Lin-, c-kit+ Sca-l- Lin- and c-kit- Sca-l- Lin-. To investigate the biological effects by $P2Y_{10}$, retroviral vector from subcloned murine $P2Y_{10}$ cDNA was used fur gene introduction into Ba/F3 cells, and stable transfectant cells were obtained by flow cytometry sorting. In cell proliferation assay, the proliferation ability of $P2Y_{10}$ receptor gene­transfected cells was strongly inhibited, and the cell cycle was arrested at G1 phase. These result suggest that the $P2Y_{10}$ may be involved the biological activity in hematopoietic stem cells and immature B lymphocytes.

• BMB Reports
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• 제36권1호
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• pp.43-48
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• 2003

Understanding the process of carcinogenesis will involve both the accumulation of many scientific facts derived from molecular, biochemical, cellular, physiological, whole animal experiments and epidemiological studies, as well as from conceptual understanding as to how to order and integrate those facts. From decades of cancer research, a number of the "hallmarks of cancer" have been identified, as well as their attendant concepts, including oncogenes, tumor suppressor genes, cell cycle biochemistry, hypotheses of metastasis, angiogenesis, etc. While all these "hallmarks" are well known, two important concepts, with their associated scientific observations, have been generally ignored by many in the cancer research field. The objective of the short review is to highlight the concept of the role of human adult pluri-potent stem cells as "target cells" for the carcinogenic process and the concept of the role of gap junctional intercellular communication in the multi-stage, multi-mechanism process of carcinogenesis. With these two concepts, an attempt has been made to integrate the other well-known concepts, such as the multi-stage, multi-mechanisn or the "initiation/promotion/progression" hypothesis; the stem cell theory of carcinogenesis; the oncogene/tumor suppression theory and the mutation/epigenetic theories of carcinogenesis. This new "integrative" theory tries to explain the well-known "hallmarks" of cancers, including the observation that cancer cells lack either heterologous or homologous gap junctional intercellular communication whereas normal human adult stem cells do not have expressed or functional gap junctional intercellular communication. On the other hand, their normal differentiated, non-stem cell derivatives do express connexins and express gap junctional intercellular communication during their differentiation. Examination of the roles of chemical tumor promoters, oncogenes, connexin knock-out mice and roles of genetically-engineered tumor and normal cells with connexin and anti-sense connexin genes, respectively, seems to provide evidence which is consistent with the roles of both stem cells and gap junctional communication playing a major role in carcinogenesis. The integrative hypothesis provides new strategies for chemoprevention and chemotherapy which focuses on modulating connexin gene expression or gap junctional intercellular communication in the premalignant and malignant cells, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제20권7호
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• pp.1015-1022
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• 2007

The spermatogonial stem cell (SSCs) is unique in that it is the only cell in the adult male that can contribute genes to a subsequent generation. Permanent modification of the germ cell line may be realized if stem cells could be cultured, transfected with unique genes, and then transplanted into recipient testes. We developed a culture system that supported long-term viability of SSCs. We used a retrovirus vector (pMSCV including ${\beta}$-galactosidase) to stably transfect spermatogonia following long-term culture using the system developed. Expression of the reporter gene ${\beta}$-galactosidase controlled by the retroviral vector was stable in long-term cultured SSCs. We confirmed the retroviral-mediated ${\beta}$-galactsidase gene could be expressed in germ cells in recipient mice following SSCs transplantation.