• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.429-434
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• 2000

Isolated protoplasts from ginseng (Panax ginseng C. A. Meyer) callus tissue were cultured in modified MS media supplemented with various concentrations of dimethylsulfoxide (DMSO). The cell wall regeneration rate and cell division efficiency of the protoplasts were increased significantly by 1% DMSO treatment. However, there was no difference in the viability of protoplasts between the DMSO treatment and non-treatment. Transmission electron microscopy revealed that the microtubules were oriented in parallel manner to the plasmalemma after 3 days of culture in medium with 1% DMSO. Further, interconnected cellulose microfibrils were observed on the outer surface of the 3-day-cultured protoplasts by scanning electron microscopy These structures shown by electron microscopy were not observed in protoplasts cultured on DMSO-free media. This studies indicates that DMSO supplemented in culture media seemed to stimulate the cell wall regeneration and cell divisions of protoplasts by forming microtubule organizing centers (MTOC).

• 대한치주과학회:학술대회논문집
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• 2007.11a
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• pp.113-114
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• 2007

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2002.11a
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• pp.51-60
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• 2002

인간이라는 개체는 한 개의 수정란에서 발생을 시작하여 개체의 크기에 따라 60조에서 100조개 정도의 세포로 구성되며, 각 세포는 모두 동일한 유전자를 가지고 있다. 인간의 염색체에 존재하는 유전자의 염기서열이 밝혀진 현재, 세포의 고유 기능을 유지하기 위하여 발현되는 유전자는 약35,000개 정도로 알려져 있다. 그러나 장기 또는 조직을 이루는 세포들은 그 조직에 따라 발현되는 유전자가 서로 다르기 때문에 상피세포, 혈액세포, 근육세포 등 모양과 기능이 다른 210여 가지의 세포로 분화되어 있다. (중략)

• The Journal of the Korean dental association
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• v.47 no.11
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• pp.728-735
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• 2009

최근 10여 년 동안 치수치료 분야는 새로운 재료와 약제의 개발 뿐 아니라 새로운 치료개념이 도입되어, 지속적인 발전이 이루어지고 있다. 특히 2007년 11월에는 미국 소아치과학회 (American Academy of Pediatric Dentistry)와 미국 근관치료학회 (American Association of Endodontists)가 공동 심포지움을 열어, 유치와 미성숙 영구치 치수치료분야에서 증거-바탕 임상 (evidence-based practice)의 구현을 위한 획기적인 공동의 노력이 있었다. 또한 치수치료 분야에 조직공학(tissue engineering)의 개념이 적용되어 치수조직의 재생에 대한 연구가 활발히 이루어지고 있다. 이번 원고에서는 유치 및 미성숙 영구치의 치수치료에서 개념에 변화가 있는 분야를 정리해 보고 새로운 술식에 대하여 다루고자 한다.

• Development and Reproduction
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• v.12 no.3
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• pp.243-250
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• 2008

Mast cells containing a variety of mediators in their cytoplasmic granules are widely distributed in connective tissues and mucosal surfaces of skin, airways, and guts. Within these tissues, mast cells are involved in the pathophysiological conditions such as inflammation, self-defense, tissue-remodeling, and autoimmunity. In order to understand the functional roles of master cells in the uterus, we histologically examined the distribution and density of uterine mast cells in the different aged mice. Until 6 weeks mast cells were sparsely detected in the uterus. But at 7 weeks after birth, when estrous cycle begins, the number of mast cells within uterine tissues increased dramatically and the increment of mast cell density continued up to 32 weeks-age. After then, uterine glandular tissue degenerated gradually and density of uterine mast cell decreased. Uterine mast cells were mainly found in the myometrium and they were closely associated with smooth muscle cells, fibroblasts, and collagens, which contents were changed according to the uterine development in the myometrium. These results suggest that uterine mast cells could be involved in myometrial contractions mediated by smooth muscle cells and tissue reconstitution or remodeling during estrous cycle and parturition including the various immunological functions.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.347-351
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• 1998

Plant regeneration via organogenesis from leaf and stipule explants of micropropagated shoots of strawberry (Fragaria $\times$ ananassa cv. Suhong) was achieved. Leaf and stipule explants were detached from shoot-tip cultured shoots and cultured on MS medium with various combinations of BA and NAA under light or dark condition. Shoot regeneration from leaf explant was observed after 3 weeks in culture and was good at the high ratio of BA and NAA among various combination treatments. The highest shoot regeneration frequency from leaf explants was obtained with 1.0 mg/L BA and 0.1 mg/L NAA, in which 31.1% shoot regeneration frequency(1.7 shoots per leaf explant) was yielded. In case of stipule explants, shoot regeneration was largely affected by plant growth regulators during incubation under dark condition for initial 4 weeks but not under continuous light condition. The combination treatment with 2.0 mg/L BA and 0.1 mg/L NAA showed the most excellent shoot regeneration from stipule explants, where 44.4% regeneration frequency(4.0 shoots per explants) obtained. Regenerated shoots were rooted on MS medium with 0.1 mg/L NAA after shoot elongation, and the plantlets regenerated were transferred to soil mixtures with vermiculite and perlite for acclimation.

• Journal of the Korean Wood Science and Technology
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• v.37 no.4
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• pp.340-348
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• 2009

The recycled polyethylene was used for making wood-plastic composite panels. In this experiment, the sizes of wood particles used were 1/32", 1/4" and 1/2" in mesh number, and the contents of the recycled polyethylene were 10%, 30% and 50%. The physical and mechanical properties of the composite panels were investigated. At a given content of recycled polyethylene, the density of composite panel decreases with the increase of wood particle size. The thickness swelling and water adsorption decrease with the increase of recycled polyethylene, where significantly lower at 10%, compared with at 30%. In the water soaking experiment for 14 days, the dimensional stability of composite panel appeared good in the composite panel with recycled polyethylene content of 30% or higher. As the content of recycled polyethylene increases, the internal bonding strength and the modulus of rupture in bending strength increases. In SEM, the molten recycled polyethylene showed interlocking action through its penetration into tracheid openings including pits as well as binder between wood particles as the matrix material, thus increasing bonding strength and improving the physical and mechanical properties of composite panel.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.95-97
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• 2003

Despite recent advances in the treatment of acute myocardial infarction, the ability to repair extensive myocardial damage is limited. To develop a new therapy for myocardial infarction, we examined the possibility of regenerating myocardium by implanting bone marrow-derived mononuclear cells(BM-MNC) . Histological and immunohistochemical examination showed myocardium regeneration and angiogenesis in the cell transplantation site. Isolated perfused (Langendorff) heart experiments revealed enhanced functions of heart. These results suggest that BM-MNC transplantation induce cardiac muscle regeneration and that this approach could be applied as a possible treatment for myocardial infarction.

• Journal of Korean Academy of Nursing
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• v.36 no.3
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• pp.523-531
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• 2006

Purpose: The purpose of this study was to examine the effects of the ulmus root-bark dressing on tissue regeneration in experimentally-induced pressure ulcers in rats. Method: A randomized pretest/post-test control group time-series study design was used. Thirty-three male Sprague-Dawley rats were used in this study. The rats were anesthetized with 100mg/kg of ketamine. Pressure ulcers were induced at 140mmHg for three hours using a personally-designed pressing apparatus. For four weeks, the ulmus root-bark dressing was applied every other day in the experimental group (n=18) and a wet gauze dressing in the control group (n=15). For data analysis, the statistical program SPSS WIN 12 was used. The wounds were examined by light microscopy andelectron microscopy. Result: There were significant statistical differences in the size of the pressure ulcers as time went by(p=0.006). It should be noted that there were no significant statistical differences in the number of capillaries. Using light microscopy the inflammatory infiltration and neovascularization in the dermis in the experimental group emerged densely in the early stages, but recovered rapidly at the latter stages. In addition, the reepithelization of the epidermis occurred earlier than in the control group. By electron microscopy, the cell organelles of the capillary endothelial cells and the basal lamina of capillaries in the experimental group showed a more rapid maturation during the latter stages, compared with the control group. Conclusion: According to this study, it can be concluded that the ulmus root-bark dressing is effective regarding the healing of pressure ulcers.

• Applied Microscopy
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• v.37 no.4
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• pp.209-217
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• 2007

The system of wound healing is very complex biological processing that includes inflammatory, reepithelialization, and matrix construction. For identification of the transitional pathway of the keratinocytes, we have employed immunohistochemical analysis using cytokeratin antibody after wounding. Epithelium in skin of the frog(Bombina orientalis) was examined with transmission electron microscopy. Cytokeratin was expressed in normal basal and gland cavity cells. At 3-hour basal layer cells were strong positive, however cells of the upper layer were negative reaction. Day1 and 2 after post-wounding, regenerating epithelial cell layer was positive reaction, especially basal layer cells were strong positive. At day 10 after wounding, the degree of positive reaction to basal cells of regenerating epithelial tissue was equal to day 7 wound tissue. At day of 19th, basal and spinous layer cells were strong positive reaction. Regenerating epithelial cells were positive but some basal cells were strong positive at day 27. From this result, we identified that the migration of the keratinocytes in amphibian skin wounds is initiated from basal layer fells and the keratinocytes migrate into basal and middle of the wound area.