• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.254-262
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• 2011

Purpose: This study aims to evaluate and prospect for current research trend and developmental perspectives via analyzing recent biomaterial coated-implants study. Materials and methods: To investigate each subject respectively, several biomaterials that are using for implant surface coating were set as 'keywords'. By these keywords, major research groups in each subject were chosen, and research trend of them was analyzed. Trend of In vivo studies that examined selected biomaterials were analyzed to evaluate commercial potential. Results: The collagen research accounted for 40% of total implant study, which was the highest, and fibronectin, BMPs (bone morphogenetic proteins) and RGD (Arg-Gly-Asp) peptides followed, which were ranked in descending order. Furthermore, figures of all four research subjects were also increased with time, especially a sharp increase in RGD research. According to the results of major research group, collagen that was combined with other organic and inorganic biomaterials was mostly examined, rather than using collagen only. Major research groups investigating BMPs mostly focused on rhBMP-2. In animal studies, collagen was used as resorbable membrane in guided bone regeneration (GBR) or drug carrier, while BMPs were used with bone graft materials or coating material for titanium implant surface. Conclusion: There is not consistency of results even in identical subjects research field. Many studies are ongoing to optimize combination between mechanical surface treatment and biomaterials such as extracellular matrix component and growth factors.

• Journal of Mushroom
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• v.2 no.1
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• pp.15-20
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• 2004

Pleurotus ostreatus, the oyster mushroom, is one of the most widely cultivated and important edible mushrooms in the world. In order to study the developmental process of P. ostreatus and its regulatory mechanism, a new culturing method needs to be established for inducing the fruiting body and sporulation in the laboratory. In this study, we have examined whether the fruiting body of P. ostreatus can be formed on the plastic petri dish which are commonly used for cell culture in the laboratory. The strain was cultured on $60{\times}15mm$ plastic petri dish with potato dextrose agar media at $28^{\circ}C$ for mycelial growth and then at $18^{\circ}C$ for the formation of primordia and fruiting bodies within plant growth chamber. The development of primordia into fruiting bodies was achieved on cultured dishes under air ventilation. At the primordia stage, the normal formation of fruiting body was blocked by sealing the plastic dish with parafilm. The periods requiring for the formation of primordia and fruiting bodies were examined on the dish culture. About 96% and 76% of cultured samples formed primordia and fruiting bodies under the optimal conditions during ten weeks of culture, respectively. These culturing periods, however, were changed by the mechanical injury treatment to mycelia. As other factors affecting the fruiting body formation, the effects of light and cold shock have been tested. No fruiting formation was observed on the cultured dishes under the dark. The cold shock treatment by storing cultured dishes for one day at $4^{\circ}C$ did not have any significant effects in the fruiting body formation. Spores of fruiting bodies acquired from the petri dishes could be germinated on culture media at $28^{\circ}C$. These results suggest that the fruiting bodies of P. ostreatus can be formed on the experimental petri dish and this dish-culturing method is useful for understanding of the developmental process of P. ostreatus in the laboratory. Furthermore, the dish-culturing method is able to shorten the life cycle of P. ostreatus without requiring large area and expensive device.

• Development and Reproduction
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• v.8 no.2
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• pp.119-122
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• 2004

It is well known that unidentified factors in sera, hormones and growth factors promote the proliferation of granulosa cells and nuclear maturation of bovine COCs in vitro. Attemps had been developed the simple composition of culture media and similar system to in vivo conditions has been applied. In the present study, we investigated the effect of TGF-${\beta}$ on in vitro maturation and in vitro development of Hanwoo COCs. When the COCs were matured in TCM 199 containing 0.1, 1 or 10 ng/ml TGF-${\beta}$ for 24 hrs, metaphaseⅡ of COCs were obtained 95.8%, 100% of matured COCs, respectively and there were no differences among the concentrations of TGF-${\beta}$. Matured COCs with TGF-${\beta}$ cultured in maturation medium after in vitro fertilization, developmental rate to blastocyst were 0~0.8%. Matured COCs with TGF-${\beta}$ were cultured in TCM 199+10% FBS, 0.8% BSA, 0.1% PVA, blastocyst formation were showed in 12.4%, 12.8%, 8.5% of those and cultured in IVMD or IVD without serum were 38.4%, 34.8%, respectively. There were significant differences among the media (P<0.05). TGF-${\beta}$ is available for i vitro maturation of bovine COCs, but further investigation would be need for finding the synergistic autocrine/paracrine fashion of other growth factors in early bovine development.

• Clinical and Experimental Pediatrics
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• v.50 no.11
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• pp.1067-1071
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• 2007

Purpose : The aim of this study was to determine whether improved survival of extremely low birth weight infants (ELBWI) was associated with decreased neurodevelopmental disability later in life, and also to identify the factors influencing this disability. Methods : ELBWI admitted to the neonatal intensive care unit of Samsung Medical Center, survived, and followed up until the corrected age of 18 months were enrolled. They were divided into two groups according to admission time: period I (1994-1999, n=36) and period II (2000-2004, n=98). Clinical data were collected retrospectively from the medical records. Results : Survival rates increased from 60.0% to 74.7%, cerebral palsy rates decreased from 22.2% to 8.2% and catch-up growth rate increased from 25.0% to 51.0% during period I and II. Despite less gestational age and birth weight, ELBWI during period II had less periventricular leukomalacia (PVL), sepsis and bronchopulmonary dysplasia compared to period I. The highest risk factors for cerebral palsy were intraventricular hemorrhage (IVH) (${\geq}$Grade III), failure of catch-up growth and PVL. Conclusion : In summary, improved viability was associated with decreased neurodevelopmental disability in ELBWI. Improved neonatal care with resultant decrease in PVL and IVH, and better nutritional support seem to be primarily responsible for this improved outcome.

• Development and Reproduction
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• v.2 no.2
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• pp.205-212
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• 1998

A sodium-independent facilitative glucose transporter 1 (Glut1) is a major route by which glucose can be transported across the plasma membrane of mouse embryo. Although it has been known that insulin-like growth factor-I (IGF-I) promotes glucose transport into the mouse embryo, whether IGF-I directly regulates transcription of Glut1 has been uncovered in mouse preimplantation embryo. This study was aimed to elucidate the role of glucose and IGF-I in development and Glut1 expression in preimplantation mouse embryo. Two-cell embryos developed in blastocyst regardless of the glucose in the presence of pyruvate. IGF-I significantly increased the number of blastomeres in the mid-blastula. Deprivation of glucose did not affect the amount of Glut1 transcripts in morula cultured from 2-cell embryo. IGF-I potentiated Glut1 expression in morula cultured from 2-cell embryo even in the absence of glucose. Taken together, it is concluded that depletion of glucose does not promote Glut1 expression the in morula cultured form 2-cell embryo, and that increment of Glut1 expression possibly mediates embryotropic effect of IGF-I on preimplantation mouse embryo.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.505-511
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• 2010

Odontoma represents 22% of all odontogenic tumors, which is characterized by slow growth pattern. Most of the odontomas usually develop during dental follicle proliferation. The growth of odontoma is limited and lesion is generally asymptomatic. It is frequently diagnosed during assessments for delayed eruption of permanent tooth and is usually founded in the second decade of life. Odontoma is usually diagnosed through radiographic views and is difficult to diagnose at the early developmental stage of odontoma. But an uncalcified developing odontoma can disturb the eruption of the tooth, so it is important to perform periodic radiographic examinations. Treatments are surgical removal and observation of odontoma followed by surgical opening or orthodontic traction of impacted tooth according to the tooth development and the location of impacted tooth. In this case, we found the radiopaque calcified odontoma in the radiographic view meanwhile follow up of the impacted tooth showing idiopathic eruption disturbance. This suggests that a developing odontoma is the cause of eruption disturbace.

• Journal of Korean Society of Forest Science
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• v.30 no.1
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• pp.50-60
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• 1976

For finding out the proper method of developing Buxus koreana var. insularis, this study was carried out in Pokil-Do, Wan-Do, Chonnam, in 1975. The ecology, morphology and characteristics of the plant were mainly investigated and analyzed. The results are summarized as follows; 1. The small islands of the southern sea of Korea; Pokil-Do, Chin-Do and So-Huk-San-Do, turn out to be the site of the natural communities of B. koreana var. insularis. 2. The growth of the plant is fairly good in the acid soil of these islands. 3. This vegetation of composed as the three-layered communities, these communities consit of Camellia, Buxus and Cares. 4. The plant is a board leaved evergreen shrub that is tolerant to shade and native to the temperate zone. 5. The size of the leaves, fruits and seeds is slightly larger than those of B. koreans. 6. As fruiting and germination of the seeds are favorable. it is easy for us to make a number of seedlings. 7. The proper times for sowing and harvesting the seeds are around the middle of July and August, respectively. 8. The seedlings is difficult to grow in the naked ground because the germinated seeds are seriously damaged by frost. 9. The plant growth per annum is about 8 to 10cm in height, 1.5mm in diameter. It is graceful looking as the branches and leaves as of the dense foliage type 10. It is possible to develop the plant in many ways, such as; ornamental plant, bee plant, sculptural and industrial materials.

• Development and Reproduction
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• v.4 no.1
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• pp.101-108
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• 2000

Objectives: The pleiotrophin (PTN) and midkine (MK) are secreted heparin-binding neurokines that share 50％ sequence homology. PTN and MK are expressed in the range of primary human tumors. The association of PTN and MK with carcinogenesis, enhancement of plasminogen activator activity and angiogenic factor are reported. Patients with endometriosis are characterized by the ability of the endometrium to implant; angiogenic and growth factors may play a significant role in the pathogenesis of endometriosis. To test the hypothesis that higher expression of PTN and MK in endometrium from women with endometriosis might be increase angiogenesis and growth ectopic endometriosis implants, we investigated PTN and MK expression by quantitative and competitive polymerase chain reaction (QC-PCR) in endometrium from women with and without endometriosis throughout the menstrual cycle. Design: MK and PTN mRNA expression in endomeoium from women with endometriosis and control patients without endometriosis were determined by QC-PCR throughout the menstrual cycle. Methods: Endometrial tissue was obtained from 25 patients with severe endometriosis and 30 patients without endometriosis undergoing hysterectomy or endometrial biopsy. Stage of endometrial cycle and a diagnosis of endometriosis were confirmed histologically. Total RNA was extracted and reverse transcribed into c-DNA. QC-PCR was performed to evaluate PTN and MK mRNA expression. Results were analysed by Post Hoc test. Results: MK and PTN were expressed throughout the menstrual cycle in both groups. MK expression was higher in follicular phase than luteal phase in endometrium from normal women. endometrium from endometriosis patients showed increased expression of PTN and MK compared to endometrium from normal women in the luteal phase (p<0.05). Conclusion: Our results suggest that uterine endometrium from women with endometriosis expresses higher levels of MK and PTN than endometrium from normal women during luteal phase. Increased MK and PTN expression may be related to the initiation of ectopic endometrial implants and their subsequent peritoneal invasion.

• Journal of Life Science
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• v.24 no.2
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• pp.196-208
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• 2014

During the life cycle of plants, water deficit leads to an adverse effect on its growth and development. To increase the productivity of crops, overcoming such drought stress is one of the most important issues in the field of plant study. Among plant hormones, the phytohormone, abscisic acid (ABA) plays a crucial role in eliciting resistance to drought stress as well as in multiple developmental processes, such as seed germination, stomatal closure, and seedling growth. Therefore, further understanding of the ABA-mediated signal transduction pathway in plants is an effective strategy to generate drought-tolerant plants. Posttranslational modification, such as phosphorylation and ubiquitination, is an efficient mechanism for plants to acquire quick adaptation against environmental stress conditions since this process directly affects pre-existing signaling components by modulating protein activity and stability. Here, recent reports on ABA signaling are reviewed, especially focusing on ABA transport, perception, signaling, and posttranslational modification in ABA-mediated cellular responses. Also, we present future prospects on how the control of such a mechanism can be applied to generate useful agricultural crops.

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.9-15
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• 2011

The functional cardiovascular system is comprised of distinct mesoderm-derived lineages including endothelial cells, vascular smooth muscle cells and other mesenchymal cells. Recent studies in the human embryonic stem cell differentiation model have provided evidence indicating that these cell lineages are developed from the common progenitors such as hemangioblasts and cardiovascular progenitor cells. Also, the studies have suggested that these progenitors have a common primordial progenitor, which expresses KDR (human Flk-1, also known as VEGFR2, CD309). We demonstrate here that sustained activation of BMP4 (bone morphogenetic protein 4) in hESC line, CHA15 hESC results in $KDR^+$ mesoderm specific differentiation. To determine whether the $KDR^+$ population derived from hESCs enhances potential to differentiate along multipotential mesodermal lineages than undifferentiated hESCs, we analyzed the development of the mesodermal cell types in human embryonic stem cell differentiation cultures. In embryoid body (EB) differentiation culture conditions, we identified an increased expression of $KDR^+$ population from BMP4-stimulated hESC-derived EBs. After induction with additional growth factors, the $KDR^+$ population sorted from hESCs-derived EBs displays mesenchymal, endothelial and vascular smooth muscle potential in matrix-coated monolayer culture systems. The populations plated in monolayer cultures expressed increased levels of related markers and exhibit a stable/homologous phenotype in culture terms. In conclusion, we demonstrate that the $KDR^+$ population is stably isolated from CHA15 hESC-derived EBs using BMP4 and growth factors, and sorted $KDR^+$ population can be utilized to generate multipotential mesodermal progenitors in vitro, which can be further differentiated into cardiovascular specific cells.