• 대한기계학회논문집B
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• 제41권11호
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• pp.743-748
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• 2017

체외 및 체내 삽입형 이미징 기술 등에 의해서는 판별이 어려운 질환의 조기 진단을 위해 인체 내 삽입이 가능하며 체내 국소부위의 정밀 측정이 가능한 새로운 진단기술이 필요하다. 동맥경화로 발전할 수 있는 죽상경화반의 경우 이미징 기술로는 판별이 어려우나 건강한 조직 대비 미세한 기계적 물성치의 차이를 가질 것으로 예상되어 정밀한 국소 조직의 기계적 강도 측정을 통한 조기 진단이 가능할 것으로 기대된다. 본 연구에서는 궁극적으로 체내 삽입이 가능하며 국소 조직의 강도 측정이 가능한 압전 재료 기반 캔틸레버 센서를 제작하고자 하였다. 압전 기능을 갖는 캔틸레버 제작을 위해 $BaTiO_3$ 나노입자 기반의 압전 고분자 복합재 최적화 연구 및 열 인장 공정으로 캔틸레버 끝 단에 마이크로 콘 구조의 팁을 제작하였다. 이 압전 캔틸레버 센서를 이용하여 기계적 물성치가 다른 생체 조직의 강도 측정을 통해 센서로서의 기능을 확인하였다.

• IMMUNE NETWORK
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• 제6권4호
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• pp.169-178
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• 2006

Background: Adipose tissues were initially introduced as energy storages, but recently they have become famous as an endocrine organ which produces and secretes various kinds of molecules to make physiologic and metabolic changes in human body. It has been studied that these molecules are secreted in abundance as the adipose tissue becomes bigger along with obesity. Furthermore, it has been found that they are mediating systemic inflammation and generation of metabolic diseases such as type 2 diabetes and atherosclerosis. On the basis of these, we studied previous papers which have been researched about the interaction between preadipocytes and macrophages, adipose tissues and lymph nodes, and adipose tissue secreting molecules. Results: Firstly, preadipocytes and macrophages are expressing similar transcriptomes and proteins, and preadipocytes can be converted to mature macrophages which have phagocytic activity. Moreover, the monocytes, which initially located in the bone marrow, are filtrated to the adipose tissue by monocyte chemotatic protein-1 and are matured to macrophages by colony stimulating factor-1. Secondly, adipose tissues and their associated lymph nodes are interacting each other in terms of energy efficiency. Lymph nodes promote lipolysis in adipose tissues, and polyunsaturated fatty acids in adipocytes become energy sources for dendritic cells. Lastly, adipose tissues produce and secrete proinflammatory molecules such as leptin, adiponectin, TNF-${\alpha}$, IL-6, and acute phase proteins, which induce the inflammation and potentially generate metabolic diseases. Conclusion: According to these, we can link adipose tissues to inflammation, but we need to affirm the actual levels and roles of adipose tissue-derived proinflammatory molecules in human body.

• Archives of Plastic Surgery
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• 제42권6호
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• pp.677-685
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• 2015

Background The survival rate of grafted fat is difficult to predict, and repeated procedures are frequently required. In this study, the effects of the freezing period of harvested adipose tissue and the addition of human adipose tissue-derived stem cells (ASCs) on the process of fat absorption were studied. Methods Adipose tissue was obtained from patients who underwent a lipoaspirated fat graft. The fat tissue was cryopreserved at $-20^{\circ}C$ in a domestic refrigerator. A total of 40 nude mice were used. The mice in the experimental group received three different subcutaneous injections in the back: an injection of fresh fat and ASCs, an injection of fat that had been frozen for one month and ASCs, and an injection of fat that had been frozen for two months and ASCs. The control mice received fat grafts without ASCs. The mice were sacrificed at four or eight weeks after the procedure, and the grafted fat tissues were harvested. The extracted fat was evaluated using photographic analysis, volume measurements, and histological examination. Results In the control group, the fat resorption rates four weeks after transplantation in the grafts of fresh fat, fat that had been frozen for one month, and fat that had been frozen for two months were 21.14%, 22.46%, and 42.56%, respectively. In the experimental group, the corresponding resorption rates were 6.68%, 13.0%, and 33.9%, respectively. Conclusions ASCs can increase the fat graft survival rate. The use of ASCs in fat grafting can reduce the need for repeated fat grafts and provide good long term results.

• Animal cells and systems
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• 제13권4호
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• pp.371-379
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• 2009

The endocannabinoid system (ECS) plays a key role in the regulation of appetite, body weight and metabolism. We undertook the present study to further clarify the regulation of the cannabinoid CB1 receptor (CB1, CNR1) in human adipose tissue in obesity. CB1 receptor mRNA expression was ~1.6-fold (p<0.004) and 1.9-fold higher (P<0.05) in subcutaneous adipocytes from obese compared to non-obese subjects in microarray and quantitative real-time PCR studies, respectively. Higher CB1 receptor mRNA expression levels in both adipose tissue (~1.2 fold, P<0.05) and adipocytes (~2 fold, P<0.01) were observed in samples from visceral compared to subcutaneous depots collected from 22 obese individuals. Immunofluorescence confocal microscopy demonstrated the presence of CB1 receptor on adipocytes and also adipose tissue macrophages. These data indicate that adipocyte CB1 receptor is up-regulated in human obesity and visceral adipose tissue and also suggest a potential role for the ECS in modulating immune/inflammation as well as fat metabolism in adipose tissue.

• Archives of Plastic Surgery
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• 제40권5호
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• pp.517-521
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• 2013

Background Diabetes is characterized by chronic hyperglycemia, which can increase reactive oxygen species (ROS) production by the mitochondrial electron transport chain. The formation of ROS induces oxidative stress and activates oxidative damage-inducing genes in cells. No research has been published on oxidative damage-related extracellular superoxide dismutase (EC-SOD) protein levels in human diabetic skin. We investigated the expression of EC-SOD in diabetic skin compared with normal skin tissue in vivo. Methods The expression of EC-SOD protein was evaluated by western blotting in 6 diabetic skin tissue samples and 6 normal skin samples. Immunohistochemical staining was also carried out to confirm the EC-SOD expression level in the 6 diabetic skin tissue samples. Results The western blotting showed significantly lower EC-SOD protein expression in the diabetic skin tissue than in the normal tissue. Immunohistochemical examination of EC-SOD protein expression supported the western blotting analysis. Conclusions Diabetic skin tissues express a relatively small amount of EC-SOD protein and may not be protected against oxidative stress. We believe that EC-SOD is related to the altered metabolic state in diabetic skin, which elevates ROS production.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2003년도 제40회 국제학술심포지움
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• pp.28-37
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• 2003

Tissue engineering and stem cells show potentials to restore lost or malfunctioning human tissues or organs. Another cell source for tissue engineering of cardiovascular tissues is stem cell. This study reports the development of cardiovascular tissues using tissue engineering and mesenchymal stem cells. The blood vessels and heart valves were fabricated by culturing mesenchymal stem cells on biodegradable synthetic or natural matrices. Bone marrow was isolated from dogs or rats and mesenchymal stem cells were cultured. The cells were seeded onto biodegradable synthetic or natural matrices and implanted in dogs. Histological and immunohistochemical analyses were performed to examine the regenerated cardiovascular tissues. Histological and immunohistochemical analyses showed the complete regeneration of blood vessels and heart valves. Fluorescent labeling of cells prior to implantation and fluorescence examination of the regenerated tissues revealed that the implanted cells reconstituted the cardiovascular tissues. This study demonstrates the potential of tissue engineering and mesenchymal stem cells for the regeneration of functional cardiovascular tissues or organs.

• Laboraroty Animal Research
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• 제34권4호
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• pp.147-159
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• 2018

Genetically engineered mouse models are commonly preferred for studying the human disease due to genetic and pathophysiological similarities between mice and humans. In particular, Cre-loxP system is widely used as an integral experimental tool for generating the conditional. This system has enabled researchers to investigate genes of interest in a tissue/cell (spatial control) and/or time (temporal control) specific manner. A various tissue-specific Cre-driver mouse lines have been generated to date, and new Cre lines are still being developed. This review provides a brief overview of Cre-loxP system and a few commonly used promoters for expression of tissue-specific Cre recombinase. Also, we finally introduce some available links to the Web sites that provides detailed information about Cre mouse lines including their characterization.

• 대한치과의사협회지
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• 제9권4호
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• pp.157-160
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• 1971

To compare the effects of various pulp capping agents that are usually applied to human pulp tissue, adult dogs were bred for a certain period and each capping agent was applied experimentally to pulp tissue after vital pulpotomy. Histological observations are as follows. 1) In comparison between methods of vital pulpotomy, one and two appointment method, different courses of healing were observed. In one appointment method, the granulation tissue formation at the amputation sur face of pulp tissue had a tendency to be transformed to scar tissue formation. In two appointment method, more transformation than that of one appointment method from scar tissue to dentin matrix formation were observed. 2) Histologic changes that have appeared in pulp tissue are a) fixation at outer layer b) degeneration at middle layer c) hyperemia and round cell infiltration at inner layer 3) With use of formocresol mixed zinc oxide powder in two appointment method complete formation of dentin matrix were observed. 4) Among the methods and aagents described above formocresol mixed zinc oxide powder in two appointment method appeared to be relatively effective.

• 한국운동역학회지
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• 제19권2호
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• pp.197-204
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• 2009

It bas been hypothesized that foot ulceration might be internally initiated. Current instruments which merely allow superficial estimate of plantar loading acting on the foot, severely limit the scope of many biomechanical/clinical studies on this issue. Recent studies have suggested that peak plantar pressure may be only 65% specific for the development of ulceration. These limitations are at least partially due to surface pressures not being representative of the complex mechanical stress developed inside the subcutaneous plantar soft-tissue, which are potentially more relevant for tissue breakdown. This study established a three-dimensional and nonlinear finite element model of a human foot complex with comprehensive skeletal and soft-tissue components capable of predicting both the external and internal stresses and deformations of the foot. The model was validated by experimental data of subject-specific plantar foot pressure measures. The stress analysis indicated the internal stresses doses were site-dependent and the observation found a change between 1.5 to 4.5 times the external stresses on the foot plantar surface. The results yielded insights into the internal loading conditions of the plantar soft-tissue, which is important in enhancing our knowledge on the causes of foot ulceration and related stress-induced tissue breakdown in diabetic foot.

• Animal Bioscience
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• 제34권7호
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• pp.1089-1099
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• 2021

With the development of sequencing technology, numerous, long noncoding RNAs (lncRNAs) have been discovered and annotated. Increasing evidence has shown that lncRNAs play an essential role in regulating many biological and pathological processes, especially in cancer. However, there have been few studies on the roles of lncRNAs in livestock production. In animal products, meat quality and lean percentage are vital economic traits closely related to adipose tissue deposition. However, adipose tissue accumulation is also a pivotal contributor to obesity, diabetes, atherosclerosis, and many other diseases, as demonstrated by human studies. In livestock production, the mechanism by which lncRNAs regulate adipose tissue deposition is still unclear. In addition, the phenomenon that different animal species have different adipose tissue accumulation abilities is not well understood. In this review, we summarize the characteristics of lncRNAs and their four functional archetypes and review the current knowledge about lncRNA functions in adipose tissue deposition in livestock species. This review could provide theoretical significance to explore the functional mechanisms of lncRNAs in adipose tissue accumulation in animals.