• Maxillofacial Plastic and Reconstructive Surgery
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• 제39권
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• pp.8.1-8.8
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• 2017

Background: For an effective bone graft for reconstruction of the maxillofacial region, an adequate vascular network will be required to supply blood, osteoprogenitor cells, and growth factors. We previously reported that the secretomes of bone marrow-derived mesenchymal stem cells (MSC-CM) contain numerous growth factors such as insulin-like growth factor (IGF)-1, transforming growth factor $(TGF)-{\beta}1$, and vascular endothelial growth factor (VEGF), which can affect the cellular characteristics and behavior of regenerating bone cells. We hypothesized that angiogenesis is an important step for bone regeneration, and VEGF is one of the crucial factors in MSC-CM that would enhance its osteogenic potential. In the present study, we focused on VEGF in MSC-CM and evaluated the angiogenic and osteogenic potentials of MSC-CM for bone regeneration. Methods: Cytokines in MSC-CM were measured by enzyme-linked immunosorbent assay (ELISA). Human umbilical vein endothelial cells (HUVECs) were cultured with MSC-CM or MSC-CM with anti-VEGF antibody (MSC-CM + anti-VEGF) for neutralization, and tube formation was evaluated. For the evaluation of bone and blood vessel formation with micro-computed tomography (micro-CT) and for the histological and immunohistochemical analyses, a rat calvarial bone defect model was used. Results: The concentrations of IGF-1, VEGF, and $TGF-{\beta}1$ in MSC-CM were $1515.6{\pm}211.8pg/mL$, $465.8{\pm}108.8pg/mL$, and $339.8{\pm}14.4pg/mL$, respectively. Tube formation of HUVECs, bone formation, and blood vessel formation were increased in the MSC-CM group but decreased in the MSC-CM + anti-VEGF group. Histological findings suggested that new bone formation in the entire defect was observed in the MSC-CM group although it was decreased in the MSC-CM + anti-VEGF group. Immunohistochemistry indicated that angiogenesis and migration of endogenous stem cells were much more abundant in the MSC-CM group than in the MSC-CM + anti-VEGF group. Conclusions: VEGF is considered a crucial factor in MSC-CM, and MSC-CM is proposed to be an adequate therapeutic agent for bone regeneration with angiogenesis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권4호
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• pp.295-307
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• 2006

Styela clava, called non-native tunicate or sea squirt, is habitat which include bays and harbors in Korea and several sites in the sea faced world. We fabricate cellulose membrane nerve conduit (CMNC) from this native sea squirt skin, and evaluate the capacity of promoting peripheral nerve regeneration in the rat sciatic nerve defect model. After processing the pure cellulose membrane from the sea squirt skin as we already published before, CMNC was designed as a non-tubular sheet with 14 mm length and 4 mm width. Total eleven male Spraque-Dawley rats (12 weeks, weighing 250 to 300g) were divided into sham group (n=2), silicone tube grafted control group (n=3) and experimental group (n=6). Each CMNC grafted nerve was evaluated after 4, 8 and 12 weeks in the experimental group, and after 12 weeks, sciatic function was evaluated with sciatic function index (SFI) and gait analysis, and histomorphology of nerve conduit and the innervated tissues of sciatic nerve were all examined using image analyzer and electromicroscopic methods in the all groups. The regenerated axon and nerve sheath were found only in the inner surface of the CMNC after 4 weeks and became more thicker after 8 and 12 weeks. In the TEM study, CMNC grafted group showed more abundant organized myelinated nerve fibers with thickened extracellular matrix than silicone conduit grafted group after 12 weeks. The sciatic function index (SFI) and ankle stance angle (ASA) in the functional evaluation were $-47.2{\pm}3.9$, $35.5^{\circ}{\pm}4.9^{\circ}$ in CMNC grafted group (n=2) and $-80.4{\pm}7.4$, $29.2^{\circ}{\pm}5.3^{\circ}$ in silicone conduit grafted group (n=3), respectively. And the myelinated axon was 41.59% in CMNC group and 9.51% in silicone conduit group to the sham group. The development of a bioactive CMNC to replace autogenous nerve grafts offers a potential and available approach to improved peripheral nerve regeneration. As we already published before, small peptide fragment derived from the basement membrane matrix proteins of squirt skin, which is a kind of anchoring protein composed of glycocalyx, induced the effective axonal regeneration with rapid growth of Schwann cells beneath the inner surface of CMNC. So the possibilities of clinical application as a peripheral nerve regeneration will be able to be suggested.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.405-418
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• 2007

Mesenchymal stem cells(MSCs) have been though to be multipotent cells that can replicate that have the potential to differentiate into lineages of mesenchymal tissue including the bone, cartilage, fat, tendon, muscle, and marrow stroma. Especially, scaffolds to support cell-based tissue engineering are critical determinants of clinical efforts to regenerate and repair the body. Selection of a matrix carrier imvolves consideration of the matrix's role as a scaffold for physical support and host tissue integration as well as its ability to support of synergize the osteoinductive program of the implanted mesenchymal stem cell. The aim of this study is to evaluate the effect of autobone and Bio-$Oss^{(R)}$ to adherent mesenchymal stem cells as scaffolds on sinus augmentation with fibrin glue mixture in a rabbit model. 16 New Zealand White rabbits were divided randomly into 4 groups based on their time of sacrifice(1, 2, 4 and 8 weeks). First, mesenchymal stem cells were isolated from iliac crest marrow of rabbits and expanded in vitro. Cell culture was performed in accordance with the technique described by Tsutsumi et al. In the present study, the animals were sacrificed at 1, 2, 4 and 8 weeks after transplantation, and the bone formation ability of each sides was evaluated clinically, radiologically, histologically and histomorphologically. According to the histological observations, autobone scaffolds group showed integrated graft bone with host bone from sinus wall. At 2 and 4 weeks, it showed active newly formed bone and neovascularization. At 8 weeks, lamellae bone was observed in sinus graft material area. Radiologically, autobone with stem cell showed more radiopaque than Bio-$Oss^{(R)}$ scaffolds group. there were significant differences in bone volume between 4 and 8 weeks(p<0.05).

• 한국언론정보학보
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• 제59권
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• pp.31-49
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• 2012

디지털 미디어 기술 발달에 따라 언론인의 직업 규범과 가치가 어떻게 변하고 있는 지를 탐구하는 것이 이 논문의 목적이다. 먼저, 19세기 말 이래 확립된 객관주의, 전문직주의 언론 규범이 새로운 미디어 생태계에서 어떤 변화의 압력을 받고 있는 지를 파악했다. 미디어 환경의 변화는 직업 언론인의 직무 수행에 $\triangle$ 인식론 측면 $\triangle$ 전문직 정체성의 측면 $\triangle$ 독자와의 상호작용 측면에서 변화를 주고 있는 것으로 나타났다. 이어 한국의 역사적 사회적 맥락에서 형성돼 공유되고 있는 언론 규범에 이런 일반적인 변화가 어떻게 투영되고 있는지를 중견 언론인들을 심층 인터뷰 해 조사했다. 인터뷰에 앞서 언론인들로 부터 '기자 정신'의 역할 모델로 인정받는 리영희 선생(1929~2010)의 언론사상을 도출해 비교의 준거로 활용했다. 즉, 이 연구는 $\triangle$실증적 글쓰기를 통한 실체적 진실 추구 $\triangle$전문성에의 열정 $\triangle$독자(민중) 와의 상호교육 등 리영희의 언론 정신으로 상징되는 한국적 언론 규범이 현재의 미디어 환경에서 어떻게 변화해 가고 있는 지를 살펴보는 탐색적 연구이다. 연구결과, 미디어 환경 변화에도 불구하고 언론인들은 실체적 진실추구, 전문성 추구, 심층 탐사보도 등 리영희의 언론정신으로 상징되는 전통 저널리즘의 규범과 가치가 직무 수행에서 여전히 중요한 지침이 된다고 보았다. 또 이런 정신이 현재 한국 저널리즘이 봉착한 위기를 극복하는 데도 긴요하다고 인식하고 있었다. 다만, 언론인들은 디지털 시대에는 이런 저널리즘의 가치를 열린 자세로 수용자와 밀접히 상호작용 함으로써 성취해야 한다고 인식하고 있었다. 진실을 가려 내 제시하는 '판별자'의 역할, 시민저널리스트와 전문가 블로거의 자원을 폭넓게 활용해 뉴스를 생산하는 '네트워크 연결점', 수많은 정보를 엮고 정리하는 '뉴스 코디네이터' 등으로 역할을 확장하는 등 새로운 미디어 기술이 제공하는 환경 변화에 능동적으로 대처해야 할 것으로 지적됐다.

• 경영과정보연구
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• 제33권4호
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• pp.99-118
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• 2014

본 연구는 속성이론을 적용하여 온라인 정보의 신뢰성이 제품을 평가하거나 판단하기 위해 온라인 정보를 사용하는 사용자의 의도에 영향을 미치는 경우를 조사하였으며, 온라인 정보 신뢰성의 영향을 조사하기 위해 온라인 정보 신뢰성의 주요 효과가 지각된 위험과 유용성의 인식에 의해 매개되는지 여부를 검사하였다. 총 287의 온라인 소비자들로부터 수집된 샘플에서 여러 항목 척도의 내적 일관성을 탐색하여 안정성을 조사 하였으며, 구조의 유효성을 위해 수렴 및 판별 타당성을 조사 하였다. 연구 모델을 테스트하기 위해 PLS 기법이 사용되었으며, 응답 데이터 세트로부터 데이터를 분석 한 결과, (1) 지각된 신뢰성의 통제성과 안정성 모두 지각된 위험도 및 유용성을 인식하고 있다는 것을 알 수 있다 (2) 지각 된 위험뿐만 아니라 유용성 인식은 부분적으로 신뢰성과 사용 의도의 두 소스 사이의 연결을 중재하고 있다. 본 연구 결과 온라인 정보 신뢰성의 두 가지 차원인 통제성과 안정성은 정보를 받는 사람의 이용의도에 영향을 미친다. 통제성 및 안정성에 대한 설명을 포함하는 온라인 정보는 소비자에게 제공된 제품 및 서비스에 대한 위험을 인지하게 할 수 있다. 따라서 높은 안정성 및 통제성을 설명하는 온라인 정보는 제공하는 온라인 정보 자체의 신뢰성을 향상시킬 뿐만 아니라 지각된 위험과 유용성을 통한 온라인 정보 활용의도를 증가시킬 수 있다.

• Journal of Periodontal and Implant Science
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• 제37권4호
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• pp.859-869
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• 2007

Naked DNA and standard vectors have been previously used for gene delivery. Among these, PEI can efficiently condense DNA and has high intrinsic endosomal activities. The aim of this study is to investigate whether the cationic polycation PEI could increase the transfection efficiency of BMP expressing DNA using a vector-loaded collagen sponge model. BMP-2/pcDNA3.1 plasmid was constructed by subcloning human BMP-2 cDNA into the pcDNA3.1 plasmid vector. PEI/DNA complexes were prepared by mixing PEI and BMP-2/pcDNA3.1 and the constructed complexes were loaded into the collagen sponges. In vitro studies, BMSCs were transfected with the PEI/BMP-2/pcDNA3.1 complexes from collgen sponge. The level of secreted BMP-2 and alkaline phosphatase activities of transfected BMSCs were significantly higher in PEI/BMP-2/pcDNA3.1 group than in BMP-2/pcDNA3.1 group (p<0.05). Transfected BMSCs were cultured and mineralization was observed only in cells treated with PEI/BMP-2/pcDNA3.1 complexes. In vivo studies, PEI/BMP-2/pcDNA3.1/collagen, BMP-2/pcDNA3.1/collagen and blank collagen were grafted in skeletal muscle of nude mice. Ectopic bone formation was shown in PEI/BMP-2/pcDNA3.1/collagen grafted mouse 4 weeks postimplantation, while not in BMP-2/pcDNA3.1 grafted tissue. This study suggests that PEI-condensed DNA encoding for BMP-2 is capable of inducing bone formation in ectopic site and might increase the transfection rate of BMP-2/pcDNA3.1. As a non-viral vector, PEI offers the potential in gene therapy for bone engineering.

• Clinical and Experimental Reproductive Medicine
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• 제24권3호
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• pp.335-340
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• 1997

Fluorescence in situ hybridization (FISH) techniques allow the enumeration of chromosome abnormalities and from a great potential for many clinical applications. In order to produce quantitative and reproducible results, expensive tools such as a cooled CCD camera and a computer software are required. We have developed a Chromosome Image Processing System (Chips) using FISH that allows the detection and mapping of the genetic aberrations. The aim of our study, therefore, is to evaluate the capabilities of our original system using a black-and-white video camera. As a model system, three repetitive DNA probes (D18Z1, DXZ1, and DYZ3) were hybridized to variety different clinical samples such as human metaphase spreads and interphase nuclei obtained from uncultured peripheral blood lymphocytes, uncultured amniocytes, and germ cells. The visualization of the FISH signals was performed using our system for image acquisition and pseudocoloring. FISH images were obtained by combining images from each of probes and DAPI counterstain captured separately. Using our original system, the aberrations of single or multiple chromosomes in a single hybridization experiment using chromosomes and interphase nuclei from a variety of cell types, including lymphocytes, amniocytes, sperm, and biopsied blastomeres, were enabled to evaluate. There were no differences in the image quality in accordance with FISH method, fluorochrome types, or different clinical samples. Always bright signals were detected using our system. Our system also yielded constant results. Our Chips would permit a level of performance of FISH analysis on metaphase chromosomes and interphase nuclei with unparalleled capabilities. Thus, it would be useful for clinical purposes.

• Journal of Ginseng Research
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• 제41권1호
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• pp.103-112
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• 2017

Background: 20(S)-Protopanaxadiol 20-O-D-glucopyranoside, also called compound K (CK), exerts antidiabetic effects that are mediated by insulin secretion through adenosine triphosphate (ATP)-sensitive potassium ($K_{ATP}$) channels in pancreatic ${\beta}$-cells. However, the antidiabetic effects of CK may be limited because of its low bioavailability. Methods: In this study, we aimed to enhance the antidiabetic activity and lower the toxicity of CK by including it with ${\beta}$-cyclodextrin (CD) (CD-CK), and to determine whether the CD-CK compound enhanced pancreatic islet recovery, compared to CK alone, in an alloxan-induced diabetic zebrafish model. Furthermore, we confirmed the toxicity of CD-CK relative to CK alone by morphological changes, mitochondrial damage, and TdT-UTP nick end labeling (TUNEL) assays, and determined the ratio between the toxic and therapeutic dose for both compounds to verify the relative safety of CK and CD-CK. Results: The CD-CK conjugate ($EC_{50}=2.158{\mu}M$) enhanced the recovery of pancreatic islets, compared to CK alone ($EC_{50}=7.221{\mu}M$), as assessed in alloxan-induced diabetic zebrafish larvae. In addition, CD-CK ($LC_{50} =20.68{\mu}M$) was less toxic than CK alone ($LC_{50}=14.24{\mu}M$). The therapeutic index of CK and CD-CK was 1.98 and 9.58, respectively. Conclusion: The CD-CK inclusion complex enhanced the recovery of damaged pancreatic islets in diabetic zebrafish. The CD-CK inclusion complex has potential as an effective antidiabetic efficacy with lower toxicity.

• Journal of Ginseng Research
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• 제41권1호
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• pp.23-30
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• 2017

Background: Ginsenoside Rg1 is a class of steroid glycoside and triterpene saponin in Panax ginseng. Many studies suggest that Rg1 suppresses adipocyte differentiation in 3T3-L1. However, the detail molecular mechanism of Rg1 on adipogenesis in 3T3-L1 is still not fully understood. Methods: 3T3-L1 preadipocyte was used to evaluate the effect of Rg1 on adipocyte development in the differentiation in a stage-dependent manner in vitro. Oil Red O staining and Nile red staining were conducted to measure intracellular lipid accumulation and superoxide production, respectively. We analyzed the protein expression using Western blot in vitro. The zebrafish model was used to investigate whether Rg1 suppresses the early stage of fat accumulation in vivo. Results: Rg1 decreased lipid accumulation in early-stage differentiation of 3T3-L1 compared with intermediate and later stages of adipocyte differentiation. Rg1 dramatically increased CAAT/enhancer binding protein (C/EBP) homologous protein-10 (CHOP10) and subsequently reduced the $C/EBP{\beta}$ transcriptional activity that prohibited the initiation of adipogenic marker expression as well as triglyceride synthase. Rg1 decreased the expression of extracellular signal-regulated kinase 1/2 and glycogen synthase kinase $3{\beta}$, which are also essential for stimulating the expression of $CEBP{\beta}$. Rg1 also reduced reactive oxygen species production because of the downregulated protein level of nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase 4 (NOX4). While Rg1 increased the endogenous antioxidant enzymes, it also dramatically decreased the accumulation of lipid and triglyceride in high fat diet-induced obese zebrafish. Conclusion: We demonstrated that Rg1 suppresses early-stage differentiation via the activation of CHOP10 and attenuates fat accumulation in vivo. These results indicate that Rg1 might have the potential to reduce body fat accumulation in the early stage of obesity.

• Journal of Ginseng Research
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• 제44권2호
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• pp.291-299
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• 2020

Background: Ginseng (G) and Ligustrum lucidum Ait (LLA) are core traditional Chinese medicines in treating myelosuppression formula. The present study was designed to profile effect of G and LLA herb pair (G-LLA) on myelosuppressed mice. Methods: The mice myelosuppression model was established by intraperitoneal (i.p.) injection of cyclophosphamide (Cy). Hematopoietic function of bone marrow was measured by hemopoietic progenitor cell culture and peripheral blood count, and serum hemopoietic factors were tested by enzyme-linked immunosorbent assay. Bone marrow cell cycle was performed by flow cytometry. HPLC was used to measure 20 potential chemical components related to myelosuppression, including ginsenoside Rg₁, Re, Rb₁, Rc, Rb₂, Rb₃, Rd, Rk₃, Rh₄, 20 (S)-Rg₃, 20 (R)-Rg₃, Rk₁, Rg₅, salidroside, and so on. Results: G, LLA, and G-LLA improved the amount of peripheral blood cells and bone marrow cells of myelosuppressed mice (P < 0.01). They significantly increased the colony quantity of colony-forming unit-granulocyte macrophage, burst-forming unit-erythroid, colony-forming unit-erythroid, and colony-forming unit-megakaryocyte and amount of G₂/M and S phase cells (P < 0.01). They also significantly decreased the amount of hematopoiesis-related cytokines (P < 0.01). The content of chemical components in G-LLA changed, and the change of rare saponin was the most obvious. Conclusion: These results show that G-LLA herb pair might produce synergistic or complementary compatibility effects on bone marrow suppression after chemotherapy. It suggests that the substance basis of G-LLA for treating bone marrow suppression may be effective chemical components.