• 대한생식의학회:학술대회논문집
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• 2003.12a
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• pp.154-155
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• 2003

• 대한생식의학회:학술대회논문집
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• 2003.12a
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• pp.102-103
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• 2003

• The korean journal of orthodontics
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• v.25 no.6 s.53
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• pp.697-704
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• 1995

Chicken calvarial bone is known to contain various cell types, but their exact composition is unknown. By characterizing the chicken calvarial bone biochemically, it can be used to study biochemical, histochemical actions of bone cells in general. Calvaria of 18-day-old white leg horn embryo was aseptically dissected and bone cell populations were isolated by sequential enzymatic digestion. Histochemical study for osteoclast-like bone cell. population was performed with tartrate resistant acid phosphatase(TRAP) stain and for osteoblast-like bone cell population, alkaline phosphatase(ALP) stain was performed. Biochemical study for osteoblast-like bone cell population was performed using alkaline phosphatase(ALP) assay. Following conclusions were obtained from this study. 1. TRAP positive multi and mononuclear cells were mostly observed in group I and II, indicating that osteoclast-like bone cell population is mostly found in these groups. 2. All the cultured groups showed almost equal ALP activities and were positive for ALP stain, indicating that osteoblast-like bone cell population is evenly dispersed in all culture groups. 3. Experimental group treated with $1,25(OH)_{2}D_3$ showed increase in ALP activity in contrast to the control group, confirming previous studies that $1,25(OH)_{2}D_3$ increases ALP activities in in vitro bone cultures. 4. Results from von Kossa's stain indicated that in vitro bone formation had occured after 3 weeks of culture with beta-glycero phosphate.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.3
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• pp.127-143
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• 2016

This study explored the variability in the accuracy of dasymetric population estimation with different grid cell sizes. Dasymetric population maps for Fulton County, Georgia in the US were generated from 30m to 420m at intervals of 30m using an automated intelligent dasymetric mapping technique, population data, and original and simulated land use and cover data. The accuracies of dasymetric population maps were evaluated using RMSE and adjusted RMSE statistics. Lumped fractal dimension values were calculated for the dasymetric population maps generated from resolutions of 30m to 420m using the triangular prism surface area (TPSA) method. The results show that a grid cell size of 210m or smaller is required to estimate population more accurately in terms of thematic accuracy, but a grid cell size of 30m is required to meet an acceptable spatial accuracy of dasymetric population estimation in the study area. The fractal analysis also indicates that a grid cell size of 120m is the optimal resolution for dasymetric population estimation in the study area.

• Microbiology and Biotechnology Letters
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• v.39 no.4
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• pp.364-373
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• 2011

Human embryonic stem cells have been highlighted as a valuable cellular source in the regenerative medicine field, due to their pluripotency. However, there is the challenge of the establishment of specific functional cell type forms of undifferentiated human embryonic stem cells (hESC). To establish and purify functional cell types from hESCs, we differentiated undifferentiated hESCs into vascular lineage cells and sorted the specific cell population from the whole cell population, depending on their cell volume, and compared them with the non-sorted cell population. We observed that about 10% of the PECAM positive population existed in the VEGF induced differentiating human embryoid body (hEB), and differentiated hEBs were made into single cells for cell transplantation. After making single cells, we performed cell sorting using a fluorescence-activated cell sorter (FACs), according to their cell volume on the basis of FSC region gating, and compared their therapeutic capacity with the non-sorted cell population through cell transplantation into hindlimb ischemic disease model mice. 4 Weeks after cell transplantation, the recovery rate of blood perfusion reached 54% and 17% in the FSC regions of sorted cells- and non-sorted cells, respectively. This result suggests that derivation of a functional cell population from hESCs can be performed through cell sorting on the basis of cell volume after preliminary differentiation induction. This approach may then greatly contribute to overcoming the limitations of marker sorting.

• Korean Journal of Clinical Pharmacy
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• v.28 no.1
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• pp.24-29
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• 2018

Background: Cyclosporine is an immunosuppressive agent used to treat and prevent graft versus host reaction (GVHR)-a complication associated with stem cell transplantation. This study aimed to develop a population pharmacokinetic model of cyclosporine and investigate factors affecting cyclosporine clearance in pediatric hematopoietic stem cell transplant patients. Methods: A total of 650 cyclosporine concentrations recorded in 65 patients who underwent hematopoietic stem cell transplantation were used. Data including age, sex, weight, height, body surface area (BSA), type of disease, chemotherapy before stem cell transplantation, type of donor, serum creatinine levels, total bilirubin concentration, hematocrit value, and type of concomitant anti-fungal agents and methylprednisolone used were retrospectively collected. Data related to cyclosporine dosage, administration time, and blood concentration were also collected. All data were analyzed using the non-linear mixed effect model; a two-compartment model with first-order elimination was used. Results: The population pharmacokinetic model of cyclosporine using the NONMEM program was as follows: $CL(L/h)=5.9{\times}(BSA/1.2)^{0.9}$, V2 (L) = 54.5, Q (L/h) = 3.5, V3 (L) = 1080.0, $k_a(h^{-1})=0.000377$. BSA was selected as a covariate of cyclosporine clearance, which increased with an increase in BSA. Conclusion: A population pharmacokinetic model for Korean pediatric hematopoietic stem cell transplant patients was developed, and the important factor affecting cyclosporine clearance was found to be BSA. The model might contribute to the development of the most appropriate dosing regimen for cyclosporine. Further studies on population pharmacokinetics should be carried out, prospectively targeting pediatric patients.

• Biomedical Science Letters
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• v.20 no.3
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• pp.147-155
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• 2014

It has well studied that immune cells are strongly related to tumor progression and tumor suppression. To identify the difference of immune cell between tumor bearing mice and normal mice, we examined systemically the immune cell of CT26 tumor bearing mice on 21 days after tumor cell administration. As previously reported, CD4+ and CD8+ T cells population of tumor bearing mice significantly decreased 38% and 30% on day 21 compared to that of normal mice, respectively. All subpopulation of CD4 and CD8+ T cell significantly decreased, except CD49b+ T cell subpopulation. But, myeloid cell population ($CD11b^{high}$ and all Gr-1+ subpopulation) of tumor bearing mice significantly increased on day 21. Especially, all subpopulation of CD11b+Gr-1+ cell of tumor bearing mice significantly increased on day 21. Also, Foxp3+$CD25^{high}$ CD4 T cell (regulatory T cells) population significantly increased on day 21. These results suggest that tumor can induce the decline of T lymphocyte and the expansion of myeloid cells and regulatory T cells, and provide the basic information for the study of tumor immunology.

• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.21-26
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• 2012

Suspension culture is a useful tool for culturing embryonic stem (ES) cells in large-scale, but the stability of pluripotency and karyotype has to be maintained $in$ $vitro$ for clinical application. Therefore, we investigated whether the chromosomal abnormality of ES cells was induced in suspension culture or not. The ES cells were cultured in suspension as a form of aggregate with or without mouse embryonic fibroblasts (MEFs), and 0 or 1,000 U/ml leukemia inhibitory factor (LIF) was treated to suspended ES cells. After culturing ES cells in suspension, their karyotype, DNA content, and properties of pluripotency and differentiation were evaluated. As a result, the formation of tetraploid ES cell population was significantly increased in suspension culture in which ES cells were co-cultured with both MEFs and LIF. Tetraploid ES cell population was also generated when ES cells were cultured alone in suspension regardless of the existence of LIF. On the other hand, the formation of tetraploid ES cell population was not detected in LIF-free condition, in which MEFs were included. The origin of tetraploid ES cell population was turned out to be E14 ES cells and not MEFs by microsatellite analysis and the basic properties of them were still maintained despite ploidy-conversion to tetraploidy. Furthermore, we identified the ploidy shift from tetraploidy to near-triploidy as tetraploid ES cells were differentiated spontaneously. From these results, we demonstrated that suspension culture system could induce ploidy-conversion generating tetraploid ES cell population. Moreover, optimization of suspension culture system may make possible mass-production of ES cells.

• Archives of Plastic Surgery
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• v.33 no.4
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• pp.433-439
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• 2006

Purpose: DNA in most cell is regularly damaged by endogenous and exogenous mutagens. Unrepaired damage resulted in apoptosis or may lead to unregulated cell growth and cancer. Inheritance of genetic variants at one or more loci results in an reduced DNA repair capacity. These polymorphisms are highly prevalent in the population, and therefore the attributable risks for cancer could be high. Several studies have documented that polymorphisms of XRCC1, XPD and XRCC3 are associated with skin cancer, especially, XRCC1 among of them has been reported frequently. So, this study involves the relationship between mutation of XRCC1 of squamous cell and basal cell cancer of the skin and risk of cancer development in Korean population. Methods: In case control study, study population (n=100, each cancer) is patients who were pathologically diagnosed as skin cancer(squamous cell carcinoma and basal cell carcinoma) in Yonsei Wonju Christian Hospital and Bundang CHA General Hospital between 1998 and 2004. The samples of DNA from whom no history of premalignant skin lesion and other malignant diseases were reported belonged to the control group(n=210). Blood and tissue samples were analyzed for presence of XRCC1 Arg399Glu, Arg280His, Arg194Trp using PCR/ RFLP method. Results: For Korean, there was a significant correlation between XRCC1 Arg399Gln gene mutation and risk of basal cell carcinoma development(Arg 399Gln(GA), p=0.012, OR=2.016, 95% CI; 1.230-3.305) /Arg399Gln (AA), p=0.011, OR=1.864, 95% CI; 1.149-3.026)). And, there was also significant correlation between XRCC1 Arg194Trp and risk of skin squamous cell carcinoma development (Arg194Trp (CT+TT), p=0.041, OR=0.537, 95% CI; 0.301-0.960)). In contrast, there was no significant correlation between XRCC1 Arg280His and risk of either basal cell carcinoma or squamous cell carcinoma development. Conclusions: Our result present that XRCC1 Arg399 Gln in basal cell carcinoma and XRCC1 Arg194Trp in squamous cell carcinoma have possibility of cancer risk and biomarker in Korean population. But XRCC1 Arg280 His known having cancer risk on other studies is not associated with cancer risk to squamous cell carcinoma and basal cell carcinoma in Korean population.

• Biomedical Science Letters
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• v.21 no.4
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• pp.172-180
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• 2015

It is well reported that tumor cells can regulate host immune systems. To identify the detailed changes of immune cells between tumor bearing mice and normal mice, we evaluated the systemic immune cell phenotype of B16F10 tumor bearing mice in a time dependent manner. The lymphocytic population (CD4+ and CD8+ T cells) of tumor bearing mice significantly decreased compared to that of normal mice. We found that the Foxp3+CD25+ CD4 T cell decreased, but the Foxp3+$CD25^{high}$ CD4 T cell significantly increased. All subpopulations of CD8 T cells decreased, except the CD62L-CD44+ CD8 T cell subpopulation. The myeloid cell population (CD11b+ and Gr-1+ cells) of tumor bearing mice significantly increased. Specifically, Foxp3+$CD25^{high}$ CD4 T cell and CD11b+Gr-1+ cells significantly increased in early phase of tumor progression. These results are helpful to understand the change of the systemic immune cell subpopulation of tumor bearing mice in a time-dependent manner.