• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권2호
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• pp.133-141
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• 2008

Stem cells have self-renewal capacity, long-term viability, and multiline age potential. Adult bone marrow contains mesenchymal stem cells. Bone marrow-derived mesenchymal stem cells (BMSCs) are progenitors of skeletal tissue components and can differentiate into adipocytes, chondrocytes, osteoblasts, and myoblasts in vitro and undergo differentiation in vivo. However, the clinical use of BMSCs has presented problems, including pain, morbidity, and low cell number upon harvest. Recent studies have identified a putative stem cell population within the adipose tissue. Human adipose tissue contains pluripotent stem cells simillar to bone marrow-derived stem cells that can differentiate toward the osteogenic, adipogenic, myogenic, and chondrogenic lineages. Human adipose tissue-derived stem cells (ATSCs) could be proposed as an alternative source of adult bone marrow stem cells, and could be obtained in large quantities, under local anesthesia, with minimal discomfort. Human adipose tissue obtained by liposuction was processed to obtain ATSCs. In this study, we compared the osteogenic differentiation of ATSCs in a specific osteogenic induction medium with that in a non-osteogenic medium. ATSCs were incubated in an osteogenic medium for 28 days to induce osteogenesis respectively. Osteogenic differentiation was assessed by von Kossa and alkaline phosphatase staining. Expression of osteocyte specific bone sialoprotein, osteocalcin, collagen type I and alkaline phosphatase, bone morphogenic protein 2, bone morphogenic protein 6 was confirmed by RT-PCR. ATSCs incubated in the osteogenic medium were stained positively for von Kossa and alkaline phosphatase staining. Expression of osteocyte specific genes was also detected. Since this cell population can be easily identified through fluorescence microscopy, it may be an ideal source of ATSCs for further experiments on stem cell biology and tissue engineering. The present results show that ADSCs have an ability to differentiate into osteoblasts. In the present study, we extend this approach to characterize adipose tissue-derived stem cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권6호
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• pp.524-529
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• 2006

For the repairing of bone defect, autogenous or allogenic bone grafting remains the standard. However, these methods have numerous disadvantages including limited amount, donor site morbidity and spread of diseases. Tissue engineering technique by culturing stem cells may allow for a smart solution for this problem. Adipose tissue contains mesenchymal stem cells that can be differentiate into bone, cartilage, fat or muscle by exposing them to specific growth conditions. In this study, the authors procured the stem cell from buccal fat pad and differentiate them into osteoblast and are to examine the bone induction capacity. Buccal fat-derived cells (BFDC) were obtained from human buccal fat pad and cultured. BFDC were analyzed for presence of stem cell by immunofluorescent staining against CD-34, CD-105 and STRO-1. After BFDC were differentiated in osteogenic medium for three passages, their ability to differentiate into osteogenic pathway were checked by alkaline phosphatase (ALP) staining, Alizarin red staining and RT-PCR for osteocalcin (OC) gene expression. Immunofluorescent and biochemical assays demonstrated that BFDC might be a distinguished stem cells and mineralization was accompanied by increased activity or expression of ALP and OC. And calcium phosphate deposition was also detected in their extracelluar matrix. The current study supports the presence of stem cells within the buccal fat pad and the potential implications for human bone tissue engineering for maxillofacial reconstruction.

• 대한음성언어의학회:학술대회논문집
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• 대한음성언어의학회 2003년도 제19회 학술대회
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• pp.183-183
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• 2003

Background and Objectives : Cartilage reconstruction is one of medical issue in otolaryngology. Tissue engineering is presently being utilized in part of cartilage repair. Sources of cells for tissue engineering are chondrocyte from mature cartilage and bone marrow mesenchymal stem cells that are able to differentiate into chondrocyte. Recent studies have shown that adipose tissue have mesenchymal stem cells which can differentiate into adipogenic, chondrogenic myogenic osteogenic cells and neural cell in vitro. In this study, we have examined chondrogenic potential of the canine adipose tissue-derived mesenchymal stem cell(ATSC). Materials and Methods : We harvested canine adipose tissue from inguinal area. ATSCs were enzymatically released from canine adipose tissue. Under appropriate culture conditions, ATSCs were induced to differentiate into the chondrocyte lineages using micromass culture technique. We used immunostain to type II collagen and toluidine blue stain to confirm chondrogenic differentiation of ATSCs. Results : We could isolate ATSCs from canine adipose tissue. ATSCs expressed CD29 and CD44 which are specific surface markers of mesenchymal stem cell. ATSCs differentiated into micromass that has positive response to immunostain of type II collagen and toluidine blue stain. Conclusion : In vitro, ATSCs differentiated into cells that have characteristic cartilage matrix molecules in the presence of lineage-specific induction factors. Adipose tissue may represent an alternative source to bone marrow-derived MSCs.

• Animal cells and systems
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• 제12권3호
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• pp.165-170
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• 2008

Cuticular hydrocarbons(CHCs) of the epicuticle wax layer are so far used to differentiate the insects in species and subspecies levels. In this study, four species of malaria vectors(genus Anopheles) were collected from various localities in southern Iran. Twenty specimens of each species were randomly selected and one epicuticular extract was prepared of every five specimens. FID-GC profiles of the extracts did not show any qualitative difference. Using significant difference of CHC mass at retention time(RT) 39.6, the two species of An. sacharovi and An. fluviatilis could be distinguished. Similarly, the two species of An. superpictus & An. sacharovi and An. dthali & An. sacharovi were differentiated by their CHC level at RT 28.5. An. sacharovi was distinguished by integratable peaks at RTs 29.7, 30.6, 30.7, 31 and 32.6 while the other three species just indicated trace peaks at the same RTs. Similarly, An. dthali could be known by an integratable peak at RT 26.2 while An. fluviatilis and An. superpictus indicated trace peaks at the same RT. Integratable peaks and traces at RTs 27.4 and 28.5 were respectively used to differentiate An. superpictus from An. fluviatilis. Lastly, CHC trace amount of An. superpictus at RT 39.6 is another indicator to distinguish it from An. fluviatilis with an integratable peak at the same RT. In harmony with other studies worldwide we hereby report that quantitative analysis of CHCs was successfully applied to differentiate the four Anopheles species of southern Iran.

• 한국산학기술학회논문지
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• 제12권9호
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• pp.4183-4191
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• 2011

구성요소가 지속적으로 생성되고 시간 흐름에 따라 변화되기도 하는 데이터 스트림의 특성을 고려하여 데이터 스트림 구성요소의 중요성을 발생 시간에 따라 차별화하기 위한 기법들이 활발히 제안되어 왔다. 기존의 방법들은 최근에 발생된 정보에 집중된 분석 결과를 제공하는데 효과적이나 보다 유연하게 다양한 형태로 정보 중요성을 차별화하는데 한계가 있다. 퍼지 개념에 기반한 정보 중요성 차별화는 이러한 한계를 보완하는 좋은 대안이 될 수 있다. 퍼지 개념은 기존의 뚜렷한 경계를 갖는 접근법의 문제점을 극복하고 실세계의 요구에 보다 부합되는 결과를 제공할 수 있는 방법으로 여러 데이터 마이닝 분야에서 널리 적용되어 왔다. 본 논문에서는 퍼지 개념을 적용하여 데이터 스트림 마이닝에서 정보 중요성 차별화에 효율적으로 활용될 수 있는 퍼지 윈도우 기법을 제안한다. 퍼지 캘린더를 포함한 기본적인 퍼지 개념에 대해서 먼저 기술하고, 다음으로 데이터 스트림 마이닝에서 퍼지 윈도우 기법을 적용한 가중치 패턴 탐색에 대한 세부 내용을 기술한다.

• Investigative Magnetic Resonance Imaging
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• 제25권2호
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• pp.101-108
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• 2021

Purpose: To identify characteristic magnetic resonance imaging (MRI) features to differentiate between Krabbe disease and metachromatic leukodystrophy (MLD) in young children. Materials and Methods: We collected all confirmed cases of Krabbe disease and MLD between October 2004 and September 2020 at Seoul National University Children's Hospital. Patients with initial MRI available were included. Their initial MRIs were retrospectively reviewed for the following: 1) presence of white matter signal abnormality involving the periventricular and deep white matter, subcortical white matter, internal capsule, brainstem, and cerebellum; 2) presence of volume decrease and signal alteration in the corpus callosum and thalamus; 3) presence of the tigroid sign; 4) presence of optic nerve hypertrophy; and 5) presence of enhancement or diffusion restriction. Results: Eleven children with Krabbe disease and 12 children with MLD were included in this study. There was no significant difference in age or symptoms at onset. Periventricular and deep white matter signal alterations sparing the subcortical white matter were present in almost all patients of the two groups. More patients with Krabbe disease had T2 hyperintensities in the internal capsule and brainstem than patients with MLDs. In contrast, more patients with MLD had T2 hyperintensities in the splenium and genu of the corpus callosum. No patient with Krabbe disease showed T2 hyperintensity in the corpus callosal genu. A decrease in volume in the corpus callosum and thalamus was more frequently observed in patients with Krabbe disease than in those with MLD. Other MRI findings including the tigroid sign and optic nerve hypertrophy were not significantly different between the two groups. Conclusion: Signal abnormalities in the internal capsule and brainstem, decreased thalamic volume, decreased splenial volume accompanied by signal changes, and absence of signal changes in the callosal genu portion were MRI findings suggestive of Krabbe disease rather than MLD based on initial MRI. Other MRI findings such as the tigroid sign could not help differentiate between these two diseases.

• Biomolecules & Therapeutics
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• 제31권3호
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• pp.264-275
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• 2023

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by tremors, bradykinesia, and rigidity. PD is caused by loss of dopaminergic (DA) neurons in the midbrain substantia nigra (SN) and therefore, replenishment of DA neurons via stem cell-based therapy is a potential treatment option. Astrocytes are the most abundant non-neuronal cells in the central nervous system and are promising candidates for reprogramming into neuronal cells because they share a common origin with neurons. The ability of neural progenitor cells (NPCs) to proliferate and differentiate may overcome the limitations of the reduced viability and function of transplanted cells after cell replacement therapy. Achaete-scute complex homolog-like 1 (Ascl1) is a well-known neuronal-specific factor that induces various cell types such as human and mouse astrocytes and fibroblasts to differentiate into neurons. Nurr1 is involved in the differentiation and maintenance of DA neurons, and decreased Nurr1 expression is known to be a major risk factor for PD. Previous studies have shown that direct conversion of astrocytes into DA neurons and NPCs can be induced by overexpression of Ascl1 and Nurr1 and additional transcription factors genes such as superoxide dismutase 1 and SRY-box 2. Here, we demonstrate that astrocytes isolated from the ventral midbrain, the origin of SN DA neurons, can be effectively converted into DA neurons and NPCs with enhanced viability. In addition, when these NPCs are inducted to differentiate, they exhibit key characteristics of DA neurons. Thus, direct conversion of midbrain astrocytes is a possible cell therapy strategy to treat neurodegenerative diseases.

• 한국식품과학회지
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• 제37권6호
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• pp.1005-1011
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• 2005

본 연구에서는 높은 분리능을 가지고 있을 뿐만 아니라 실험의 재현성과 경제성의 측면에서도 많은 장점을 갖고 있는 ERIC DNA sequence를 응용한 ERIC-PCR을 이용하여 Salmonella, E. coli, Shigella, Vibrio 등 4속의 주요 그람 음성 식중독유발 세균들의 분리 동정 방법을 확립하고자 하였다. ERIC-PCR 결과, E. coli의 경우 0.3kb, 0.42kb 및 1.2kb의 band가 모든 균주에서 공통적으로 확인되었고, Salmonella속으로부터는 0.22kb, 0.4kb 및 0.7kb의 band가 증폭되었다. Shigella속은 모든 표준균주와 분리균주로부터 0.33kb와 1.25kb의 band가 증폭되었으며, S. sonnei의 경우 위의 주요 2개 band 이외에도 대부분의 균주에서 0.44kb, 2.0kb 및 3.05kb의 band가 증폭되어 다른 종의 Shigella와 구별되는 fingerprinting pattern을 나타내었다. 그리고 V. parahaemolyticus의 경우 표준균주와 분리균주 모두 0.51kb와 1.5kb의 band가 증폭되어 V. cholerae, V. mimicus 등과 같은 다른 종의 Vibrio와 구별되는 fingerprinting pattern을 나타내었다. 이와 같이 4속의 모든 식중독 균주마다 ERIC-PCR후 생성되는 fingerprinting pattern에서 3-5개의 공통적인 band가 증폭되는 것이 확인되어 이를 이용한 속 수준의 분리 동정과 이러한 주요 band들 이외의 부수적인 band들을 고려하여 종 수준까지의 분리도 가능함을 확인하였다. 따라서 본 연구의 결과는 ERIC 반복적 DNA 염기서열을 이용한 ERIC-PCR이 식중독균의 분리 동정 방법으로 사용될 수 있음을 확인하였으며, 나아가 더 많은 속(genus)의 식중독세균을 대상으로 한 새로운 분리 동정 방법을 확립하는데도 응용이 될 수 있을 것이다.

• Archives of Pharmacal Research
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• 제13권1호
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• pp.105-107
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• 1990

The absence, in the biomass, of glutamic-oxalacetic and glutamic-pyruvic transaminases and the prevalance of gamma-glutamic transpeptidase were taken as basic criteria to differentiate between Erwinia carotovora var. carorovora from E. carotovora var, citrullis and E. toxica. For further identification, detection of cholesterol in the biomass confirmed the toxica species whereas the absence of glucose confirmed the citrullis variety.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.37.4-37
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• 2002

$\textbullet$ Feature extraction method for robot application $\textbullet$ Using ultrasonic sensor arrays $\textbullet$ Differentiate the target as plane, corner and edge $\textbullet$ Neural network approach