• Archives of Craniofacial Surgery
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• v.20 no.1
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• pp.10-16
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• 2019

Background: Physicians tend to overcorrect when applying the acellular dermal matrix for reconstructive option because of volume decrement problem after absorption comparing with initial volume. However, there are no studies on the exact volume decrement and absorption rate with commercial products in South Korea. To figure out absorption rate of acellular dermal matrix product in South Korea (Megaderm), authors designed this experiment. Methods: Nine mice were used and randomly divided into three groups by the time with sacrificing. The implant (Megaderm) was tailored to fit a cuboid form ($1.0cm{\times}1.0cm$ in length and width and 2.0 mm in thickness). A skin incision was made at anterior chest with blade #15 scalpel with exposing the pectoralis major muscle. As hydrated Megaderm was located upon the pectoralis major muscle, the skin was sutured with Ethilon #5-0. After the surgical procedure, each animal group was sacrificed at 4, 8, and 12 weeks, respectively, for biopsies and histological analysis of the implants. All samples were stained with routine hematoxylin and eosin staining and Masson's trichrome staining and the thickness were measured. A measurements were analyzed using Friedman test. Statistically, the correlation between thicknesses of Megaderm before and after implantation was analyzed. Results: After sacrificing the animal groups at postoperative 4, 8, 12 weeks, the mean tissue thickness values were $2.10{\pm}1.03mm$, $2.17{\pm}0.21mm$, and $2.40{\pm}0.20mm$ (p= 0.368), respectively. The remaining ratios after absorption comparing with after initial hydrated Megaderm were 82.7%, 85.4%, and 94.5%, respectively. In histopathological findings, neovascularization and density of collagenous fiber was increased with time. Conclusion: Author's hypothesis was absorption rate of implant would be increased over time. But in this experiment, there is no statistical significance between mean absorption thickness of implant and the time (p= 0.368). Also it can be affected by graft site, blood supply, and animals that were used in the experiment.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.652-663
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• 1999

Craniosynostosis, the premature fusion of cranial sutures, presumably involves disturbance of the interactions between different tissues within the cranial sutures. Interestingly, point mutaions in the genes encoding for the fibroblast growth factor receptors(FGFRs), especially FGFR2, cause various types of human craniosynostosis syndromes. To elucidate the function of these genes in the early morphogenesis of mouse cranial sutures, we first analyzed by in situ hybridization the expression of FGFR2(BEK) and osteopontin, an early marker of osteogenic differentiation, in the sagittal suture of calvaria during embryonic(E15-E18) and postnatal stage(P1-P3). FGFR2(BEK) was intensely expressed in the osteogenic fronts, whose cells undergo differentiation into osteoprogenitor cells that ultimately lay down the bone matrix. Osteopontin was expressed throughout the parietal bones excluding the osteogenic fronts, the periphery of the parietal bones. To further examine the role of FGF-mediated FGFR signaling in cranial suture, we did in vitro experiments in E15.5 mouse calvarial explants. Interestingly, implantation of FGF2 soaked beads onto both the osteogenic fronts and mid-mesenchyme of sagittal suture after 36 hours organ culture resulted in the increase of the tissue thickness and cell number around FGF2 beads, moreover FGF4-soaked beads implanted onto the osteogenic fronts stimulated suture closure due to an accelerated bone growth, compared to FGF4 beads placed onto mid-mesenchyme of sagittal suture and BSA control beads. In addition FGF2 induced the ectopic expression of osteopontin and Msx1 genes. Taken together, these data indicate that FGF-mediated FGFR signaling has a important role in regulating the cranial bone growth and maintenance of cranial suture, and suggest that FGF-mediated FGFR signaling is involved in regulating the balance between the cell proliferation and differentiation through inducing the expression of osteopontin and Msx1 genes.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.1
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• pp.87-92
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• 1998

This study was carried out to investigate in vitro/in vivo development of vitrified mouse oocytes. Mouse oocytes were vitrified using EFS30, 35 and 40 (30, 35 and 40% ethylene glycol, 18% ficoll and 0.5 M sucrose in M2 medium). After being exposed or vitrified-thawed, oocytes of normal morphology were inseminated in vitro by $1-2\times10^6/ml$ of epididymal sperm. The rates of fertilization, in vitro/in vivo development and cell number (inner cell mass and tropectoderm cell) of blastocysts in each treatment group were examined. The results obtained in these experiments were summarized as follows: The cleavage rates were obtained in EFS35 containing 35% ethylene glycol higher than in EFS30 and EFS40. The development rate of vitrified-thawed oocytes to two-cell stage after in vitro fertilization (51.1%) was significantly different compared to that of exposed to vitrification solution without cooling (60.0%) and control (68.2%) (p<0.05). However, there were no differences in the blastocyst formation from the cleaved embryos among groups (75.0, 73.3 and 80.0%). Also, the mean number of cells per blastocysts of vitrified group $(92.5{\pm}2.9)$ was similar to that of the exposed $(98.5{\pm}5.3)$ and control $(100.9{\pm}4.8)$. In vivo development of the blastocysts derived from vitrified-thawed oocytes resulted in fetal development (50.7%) and implantation rates (80.0%) which are very similar to those of control (58.2, 78.2%). These results suggest that mouse oocytes could be cryopreserved using vitrification solution (EFS35) based on ethylene glycol.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1470-1475
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• 1998

Two kinds of Korean rice-wine (Yakju) with different process and ingredients, and Japanese rice-wine (Sake) were chosen for this study, and throughly dried and solubilized in water or cell culture medium. In vitro cytotoxicity assays of the solubilized wine solids exhibited that maximum dilution factors for inhibition of B 16BL6 mouse melanoma cell growth were 16X for herbal medicine-added rice-wine (Korean rice-wine I) and typical Korean rice-wine (Korean rice-wine II), and 8X for Japanese rice-wine. Their cytotoxic effects on HRT18 human colon adenocarcinoma cells were even lower than those on B16BL6 cells. The morphology of the tumor cells were changed by addition of the solubilized wine solids. Inhibitory effect of the rice-wine on in vivo tumor growth and metastasis were monitored after implantation of B16BL6 cells into C57BL/6 mice with daily feeding the solubilized wine solids. Compared to non-fed control groups, B16BL6 tumor growth and metastasis to lung were clearly inhibited by feeding the wine solids, in order of Korean rice-wine I > Korean rice-wine II > Japanese rice-wine. The data of in vitro cytotoxicity and the cell shape changes indicate that the inhibitory effect of tumor progression may be attributed to tumor cell differentiation or immune stimulation induced by certain components in the rice-wine, rather than direct cytotoxicity of the components.

• Journal of Radiation Protection and Research
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• v.21 no.4
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• pp.273-284
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• 1996

Embryos and fetuses are more sensitive to various environmental agents than are adults or children. The biological effects such as intrauterine death and malformation are closely connected with prenatal exposure very various agents. The sensitivity of these embryonic/fetal effects depends on the stage of pregnancy. From the viewpoint of fetal development, embryonic and fetal stages can be divided into three stages : Preimplantation, organogenetic and fetal. Each stage corresponds to 0 to 4.5days, 4.5 to 13.5days, and 13.5days of gestation in mice, respectively. Many studies on the biologcal effects of mice irradiated by ${\gamma}-rays$ at various stages during organogenesis and fetal period have been performed. Based on these results, the dose-effect and dose-response relationships in malformations, intrauterine death, or retardation of the physical growth have been practically modeled by the ICRP(International Commission on Radiological Protection) and other international bodies for radiation protection. Many experimental studies on mice have made it clear that mice embryos in the preimplantation period have a higher sensitivity to radiation for lethal effects than the embryos/fetuses on other prenatal periods. However, no eratogenic effects of radiation at preimplantation stages of mice have been described in many textbooks. It has been believed that 'all or none action results' for radiation of mice during the preimplantation period were applied. The teratogenic and lethal effects during the preimplantation stage are one of the most important problems from the viewpoint of radiological protection, since the preimplantation stage is the period when the pregnancy itself is not noticed by a pregnant woman. There are many physical or chemical agents which affect embryos/fetuses in the environment. It is assumed that each agents indirectly effects a human. Then, a safety criterion on each agent is determined independently. The pregnant ICR mice on 2, 48, 72 or 96 hours post-conception (hpc), at which are preimplantation stage of embryos, were irradiated whole body Cesium-gamma radiation at doses of 0.1, 0.25, 0.5, 1.5, and 2.5 Gy with dose rate of 0.2 Gy/min. In the embryos from the fetuses from the mice irradiated at various period in preimplantation, embryonic/fetal mortalities, incidence of external gross malformation, fetal body weight and sex ratio were observed at day 18 of gestation. The sensitivity of embryonic mortalities in the mice irradiated at the stage of preimplantation were higher than those in the mice irradiated at the stage of organogenesis. And the more sensitive periods of preimplantation stage for embryonic death were 2 and 48 hpc, at which embryos were one cell and 4 to 7 cell stage, respectively. Many types of the external gross malformations such as exencephaly, cleft palate and anophthalmia were observed in the fetuses from the mice irradiated at 2, 72 and 96 hpc. However, no malformations were observed in the mice irradiated at 48 hpc, at which stage the embryos were about 6 cell stage precompacted embryos. So far, it is believed that the embryos on preimplantation stage are not susceptible to teratogens such as radiation and chemical agents. In this study, the sensitivity for external malformations in the fetuses from the mice irradiated at preimplantation were higher than those in the fetuses on stage of organogenesis.

• Development and Reproduction
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• v.2 no.2
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• pp.179-187
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• 1998

The effects of prostaglandins in hatching and implantation have been studied but the results were various, and those are not well known by the embryonic stage. The present study examined the effects of prostaglandin $E_2$(PG $E_2$) and prostaglandin $F_2$$_{\alpha}$ (PG $F_2$$_{\alpha}$) on the expansion and hatching of mouse embryos by embryonic stage. Also we tried to measure the concentration of prostaglandins of morula, expanded, and hatching embryos. In early morula stage embryos, high concentration of PG $E_2$(>100$\mu$M) showed cytotoxicity but PG $F_2$$_{\alpha}$ did not. The hatching was inhibited all groups but not gave negative effects on expansion. In 84 hr and 96 hr stage embryos, the hatching rate was decreased at all treatment groups but not inhibited the expansion. When combine prostaglandin with indomethacin, the hatching rate was increased significantly compared to the prostaglandin-treated groups, and as lower and lower the PG $E_2$ concentration, the hatching rate increased to the control level. The embryonic synthesis of PG $E_2$ increased dramatically but that of PG $F_2$$_{\alpha}$ increased gradually. PG $E_2$ showed cytotoxicity at early stage embryos much than late stage embryos, but PG $F_2$$_{\alpha}$ did not. Hatching was inhibited by the high PG $F_2$$_{\alpha}$ concentration. It is suggested that the inhibition of hatching might be at resulted from cytotoxicity of PG $E_2$ on embryo. However, it is thought that the mechanisms of inhibition of hatching are different between PG $E_2$ and PG $F_2$$_{\alpha}$. In conclusion, it can be suggested that PG $E_2$ and PG $F_2$$_{\alpha}$ concerned with the expansion and hatching, and their effects on hatching were different by the embryonic stage.$/ concerned with the expansion and hatching, and their effects on hatching were different by the embryonic stage.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.1
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• pp.33-46
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• 2005

연구목적: ADAMs은 metalloprotease/disintegrin domain을 가진 transmemebrane glycoprotein으로써 지금까지 30개 이상의 ADAM 및 10개 이상의 ADAMTS가 알려져 있다. 이들의 기능은 포유동물의 수정 시 sperm-egg binding과 fusion, myoblast fusion, integrin과의 결합 등에 직접 관여하거나, TNF-alpha 등의 생체신호전달물질이 세포로부터 분비될 때에 이들의 구조를 변화시켜 활성화시키는 효소작용, 그리고 dendritic cell differentiation 등에 관여하는 것으로 알려져 있다. 그러나 자궁내막 조직에서의 유전자 및 단백질 발현 여부에 관해서는 거의 보고되어 있지 않고 있다. 본 연구에서는 착상 전후 시기의 생쥐 자궁조직에서 ADAM-8, 9, 10, 12, 15, 17 그리고 ADAMTS-1의 유전자가 발현하는 지를 알아보았다. 연구 재료 및 방법: 본 연구에서는 생쥐의 자궁조직을 대상으로 ADAM-8, 9, 10, 12, 15, 17 그리고 ADAMTS-1을 선정하여, 초기 임신 기간에서의 유전자 발현 여부를 조사하였고 이 결과를 바탕으로 자궁조직에서의 이들 유전자들의 생리적인 기능을 규명하고자 하였다. 결 과: 임신한 생쥐 자궁조직에서의 ADAM-8, 9, 10, 12, 15, 17 그리고 ADAMTS-1의 유전자 및 단백질의 발현 양상을 RT-PCR 방법을 이용하여 알아본 결과, 조사된 ADAM 종류와 임신 날짜별로 다르게 나타났다. ADAM-8의 유전자 전사체는 임신 1일째 매우 강하게 발현되었으나 임신 3일째로 진행되면서 감소하다가 이후 다시 임신 5일째가 되면서 증가하는 양상을 보였다. ADAM-9, 10, 17 그리고 ADAMTS-1의 경우는 임신 1일째에서 5일째까지 유전자의 발현 양상이 크게 변하지 않았고 ADAM-12와 ADAM-15의 유전자 전사체는 임신 1일에서 5일로 진행되면서 현저하게 증가되는 양상을 보였다. 이후 임신 6일에서 8일에서는 생쥐 배아가 착상된 부위와 비 착상부위로 나누어 유전자의 발현 양상을 관찰한 결과, 조사된 ADAM 모두 비착상 부위보다 착상부위에서 유전자 전사체의 발현이 크게 증가되는 것으로 나타났다. 결 론: 이상의 결과로 미루어 ADAM 유전자는 임신초기 착상과정과 임신 단계에 따른 자궁의 조직 재구성에 중요한 역할을 할 것으로 생각된다.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.2
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• pp.97-106
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• 2010

Aim of the study: An alternative source of adult stem cells that could be obtained in large quantities, under local anesthesia, with minimal discomfort would be advantageous. Adipose tissue could be processed to obtain a fibroblast-like population of cells or adipose tissue-derived stromal cells (ATSCs). This study was performed to confirm the availability of ATSCs in bone tissue engineering. Materials amp; Methods: In this study, adipose tissue-derived mesenchymal stem cell was extracted from the liposuctioned abdominal fat of 24-old human and cultivated, and the stem cell surface markers of CD 105 and SCF-R were confirmed by immunofluorescent staining. The proliferation of bone marrow mesenchymal stem cell and ATSCs were compared, and evaluated the osteogenic differentiation of ATSCs in a specific osteogenic induction medium. Osteogenic differentiation was assessed by von Kossa and alkaline phosphatase staining. Expression of osteocyte specific BMP-2, ALP, Cbfa-1, Osteopontin and osteocalcin were confirmed by RT-PCR. With differentiation of ATSCs, calcium concentration was assayed, and osteocalcin was evaluated by ELISA (Enzyme-linked immunosorbant assay). The bone formation by 5-week implantation of HA/TCP block loaded with bone marrow mesenchymal stem cells and ATSCs in the subcutaneous pocket of nude mouse was evaluated by histologic analysis. Results: ATSCs incubated in the osteogenic medium were stained positively for von Kossa and alkaline phosphatase staining. Expression of osteocyte specific genes was also detected. ATSCs could be easily identified through fluorescence microscopy, and bone formation in vivo was confirmed by using ATSC-loaded HA/TCP scaffold. Conclusions: The present results show that ATSCs have an ability to differentiate into osteoblasts and formed bone in vitro and in vivo. So ATSCs may be an ideal source for further experiments on stem cell biology and bone tissue engineering.

• Journal of Life Science
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• v.28 no.7
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• pp.811-818
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• 2018

This study was performed to investigate the localization and concentration changes of mercury compound in female reproductive organs with time. Methylmercuric chloride was subcutaneously injected weekly into pubescent female mice for 3 weeks. For the concentration changes of mercury with time, the mice were sacrificed at 10, 150, and 300 days post treatment (DPT). Body and organ weights were not significantly different between the control and mercury-treated groups, except for 10 DPT in body weight. Localization of accumulated mercury was identified by the autometallography method. Localization of mercury compounds in the uterus, ovary, and ovum was analyzed with a light microscope. In the uterus, mercury was densely located in the stroma cells and surface epithelium of the perimetrium at 10 DPT. Mercury concentration was decreased at 150 DPT and did not appear at 300 DPT. In the ovary, mercury particles were distributed in the stroma cells of the cortex region, cells of the theca around the follicle, and the corpus luteum at 10 DPT. Mercury was concentrated in the medulla region at 150 DPT and was not distributed at 300 DPT. In the ovum, mercury particles were mainly located in the marginal region at 10 and 150 DPT. Mercury concentration was decreased and evenly distributed at 300 DPT. These results suggest that hormone synthesis, implantation, and developing embryos will be affected by mercury compound in the female mouse.

• Journal of Biomedical Engineering Research
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• v.16 no.3
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• pp.331-336
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• 1995

A composite material was produced as an artificial bone substitute which is gradually degrAded and replaced by the regenerated natural bones after implantation. To detect the effect of the material on the cell's activity, the composite specimens were placed in MEMs and incubated at $37^{\circ}C$ for one week. Human uterus cervical cancer origin HeLa 3 cells and mouse subcutaneous origin L929 cells were cul- tured in the specimen dissolved MEMs for 5 days to investigate cytotoxicity via cell growth rates. ${Na_2}^{51}CrO_4$ solution was added to the media, to label the HeLa 53 cells, and the released amount of $^{51}Cr$ was measured by a $\gamma$-counter. On the cell growth investigation, no significant cytotoxic phenomena were revealed in both HeLa S3 and L929 cell cultures. On the released 51CR from the incubated HeLa 53 cells, no significant cell degeneration was observed from the composite embedded MEMs.