A Comparison of Lyophilized Amniotic Membrane with Cryopreserved Amniotic Membrane for the Reconstruction of Rabbit Corneal Epithelium

Ahn Jae-Il,Jang In-Keun,Lee Doo-Hoon,Seo Young-Kwon,Yoon Hee-Hoon,Shin Youn-Ho,Kim Jae-Chan,Song Kye-Yong,Lee Hee-Gu,Yang Eun-Kyung,Kim Ki-Ho,Park Jung-Keung The Korean Society for Biotechnology and Bioengine 2005 Biotechnology and Bioprocess Engineering Vol.10 No.3

Many researchers have employed cryopreserved amniotic membrane (CAM) in the treatment of a severely damaged cornea, using corneal epithelial cells cultured on an amniotic membrane (AM). In this study, two Teflon rings were made for culturing the cells on the LAM and CAM, and were then used to support the AM, which is referred to in this paper as an Ahn's AM supporter. The primary corneal epithelial cells were obtained from the limbus, using an ex-plantation method. The corneal epithelium could be reconstructed by culturing the third­passage corneal epithelial cells on the AM. A lyophilized amniotic membrane (LAM) has a higher rate of graft take, a longer shelf life, is easier to store, and safer, due to gamma irradiation, than a (AM. The corneal epithelium reconstructed on the LAM and (AM, supported by the two­Teflon rings, was similar to normal corneal epithelium. However, the advantages of the LAM over that of the (AM make the former more useful. The reconstruction model of the corneal epithelium, using AM, is considered as a good in vitro model for transplantation of cornel epithelium into patients with a severely damaged cornea.

[논문]예비 과학교사의 방사선에 대한 개념 및 인식조사

강연수,안정근 釜山大學校 師範大學 科學敎育硏究所 2010 科學敎育硏究報 Vol.37 No.-

A Survey of Pre-service Science Teacher's Perception and Conceptions of Radiation

Reconstruction of Rabbit Corneal Epithelium on Lyophilized Amniotic Membrane Using the Tilting Dynamic Culture Method

Ahn, Jae-Il,Lee, Doo-Hoon,Ryu, Yang-Hwan,Jang, In-Keun,Yoon, Mun-Young,Shin, Youn Ho,Seo, Young-Kwon,Yoon, Hee-Hoon,Kim, Jae-Chan,Song, Kye-Yong,Yang, Eun-Kyung,Kim, Ki-Ho,Park, Jung-Keug Blackwell Publishing Inc 2007 Artificial Organs Vol.31 No.9

<P>Abstract: </P><P>Rabbit corneal epithelium was reconstructed using tilting dynamic culture with a self-manufactured, amniotic membrane (AM) supporter and a lyophilized amniotic membrane (LAM). Rabbit corneal epithelial (RCE) cells were cultured and cryopreserved after isolation from the limbus. The second- and third-passage RCE cells were plated onto the epithelial side of the LAM of Ahn's AM supporter. Two days later, the air–liquid interface culture was maintained with third-passage RCE cells for 6 days and second-passage corneal epithelial cells for 9 days. The average viability of thawed RCE cells, assessed using trypan blue dye exclusion, was 77.42%. The reconstructed corneal epithelium was characterized by histological (hematoxylin and eosin) and immunohistochemical staining (proliferating cell nuclear antigen) for light microscopy, and by reverse transcriptase-polymerase chain reaction, glucose assay, and transmission electron microscopy. The basal layer of the reconstructed corneal epithelium was well formed, and the epithelium was tightly constructed due to the increase in cell proliferation and differentiation caused by the tilting dynamic culture, as opposed to static culture. Tilting dynamic culture was useful for the reconstruction of the epithelium using easily damaged epithelial cells and resulted in more stratum cell layers. Moreover, cytokeratin (CK3) mRNA expression in tilting dynamic cultured third-passage RCE cells seeded onto AM was greater than in static cultured third-passage RCE cells. The morphology of the reconstructed corneal epithelium on LAM by tilting dynamic culture for 9 days resembled that of the skin epidermis. This was thought to be because the tilting dynamic culture not only accelerated the proliferation and differentiation of cells by physical or mechanical stimulation, but also ensured that the supply of medium was delivered to the basal cells more efficiently. Thus, the reconstruction of the corneal epithelium using LAM and tilting dynamic culture was considered to be a good in vitro model for autologous or allogeneic transplantation of corneal epithelium and skin epidermis in patients with damaged epithelia. </P>

자일리톨 섭취에 따른 Streptococcus mutans의 글루칸 생성관련 유전자 발현 억제효과

김지혜,이영은,안상헌,최연희,남순현,송근배 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.4

본 연구에서는 장기적인 자일리톨의 섭취가 Streptococcus mutans의 대표적인 독성인자 중 하나인 글루칸 생성에 미치는 영향을 알아보기 위하여 글루칸 합성효소인 glucosyltansferase의 mRNA 발현을 실시간 역전사 중합효소 연쇄반응을 통해 평가하여 다음과 같은 결과를 얻었다. 1. 24개월 동안 자일리톨껌을 섭취한 군에서 타액 내 Streptococcus mutans의 colony 수는 통계적으로 유의하게 감소하였다(p<0.05). 2. 비수용성 글루칸 합성에 관여하는 유전자인 gtfB, gtfC의 발현은 자일리톨껌을 섭취한 군에서 시간이 지남에 따라 유의 하게 감소하였다(p<0.05). 특히 gtfB의 발현은 12개월과 24개월째 대조군에 비하여 통계적으로 유의하게 낮았고, gtfC의 발현은 24개월째 대조군에 비하여 통계적으로 유의하게 낮았다(p<0.05). 3. 수용성 글루칸 합성에 관여하는 유전자인 gtfD의 발현 역시 자일리톨껌을 섭취한 군에서 시간이 지남에 따라 유의하게 감소하였다(p<0.05). 또한 gtfD의 발현은 12개월과 24개월째 대조군에 비하여 통계적으로 유의하게 낮았다(p<0.05). 이상의 결과들을 종합해 보았을 때, 자일리톨의 섭취는 구강 내 Streptococcus mutans의 글루칸 합성 관련 유전자들의 발현을 억제시킴으로써 Streptococcus mutans의 수적인 감소를 가져오는 것으로 생각된다. Xylitol has the ability to reduce the adherence of Streptococcus mutans(S. mutans), which can make it easier to remove plaque, decrease acid production and inhibit dental caries. There are few reports on the effects of xylitol on the expression of the virulence related genes in S. mutans. This study examined the inhibitory effect of chewing gum containing xylitol on glucan synthesis related gene expression of S. mutans. Participants were voluntarily recruited for a women's oral health prevention program, classified into two groups(a control and a xylitol group), and then followed for 2 years. Twenty salivary samples were randomly selected from each group. Colony count and real-time reverse transcription polymerase chain reaction were used to analyze the characteristics of S. mutans. The following results were obtained: The S. mutans counts decreased steadily in the xylitol group over the study period(p<0.05). The expression of the virulence related genes (gtfB, gtfC and gtfD) was significantly lower in the xylitol group than in the control groups (p<0.05). In conclusion, these results suggest that chewing xylitol gum for a long period of time may reduce the expression of the genes associated with S. mutans virulence, which can result in a decrease growth of S. mutans colonies as a result.

Profiling Transcripts by EST from Vitis coignetiae against Anthracnose Infection

Youn Jung Choi,Soon Young Ahn,Seung Hui Kim,Youn Young Hur,Hae Keun Yun 한국국제농업개발학회 2011 韓國國際農業開發學會誌 Vol.23 No.4

머루(Vitis coignetiae)는 국내에 자생하는 야생종 포도의 한 종류로서, 포도 새눈무늬병에 저항성이다. 내병성 포도 육종에 활용할 유용한 육종소재를 개발하고자 머루의 잎과 과실로부터 cDNA libraray를 제작하였다. 머루의 cDNA library의 총 5,760개의 EST 클론을 분석하여 676개의 contig와 2,306개의 singleton을 분리하여 총 2,982개의 unigene을 분리하였다. NCBI 데이터베이스의 BLAST를 통한 상동성을 검색한 결과, 2,241개의 클론이 기능이 알려진 유전자이었고, 그 중에서 1,442개는 생물학적인 대사에 관여하고 836개는 세포구성물과 관련이 있었다. EST와 contig의 평균 크기는 각각 702bp와 757bp이었다. 포도새눈무늬병균에 감염된 머루 cDNA library로부터 Proline-rich cell wall protein, thaumatin-like protein, class IV chitinase, and pathogenesis-related (PR) protein 10 등의 다양한 방어관련 유전자와 광합성관련유전자 및 수분스트레스 저항성 관련유전자가 많이 검출되었다. 본 연구를 통해 얻어진 머루의 EST 자료는 포도의 새로운 유전자원에 관한 연구 및 내병성 포도 신품종 육종 프로그램에 기본자료로 유용하게 활용될 것이다. Vitis coignetiae, a wild grape native to Korea, is resistant to anthracnose diseases. For screening useful resources for disease-resistant grape breeding, a cDNA library was constructed from leaves of wild grapes. A total of 2,982 unigenes containing 676 contigs and 2,306 singletons were obtained by sequencing 5,760 expressed sequence tag (EST) clones derived from the cDNA library of wild grape, V. coignetiae infected with Elsinoe ampelina causing anthracnose disease. In gene ontology analysis, 2,241 genes with molecular functions were annotated into 1,442 biological processes, and 836 cellular component genes. The average lengths of the ESTs and contigs were 702 and 757 bp, respectively. Various defense-related genes, such as putative proline-rich cell wall protein, thaumatin-like protein, class IV chitinase, and pathogenesis-related (PR) protein 10, photosynthesis-related genes, such as ribulose-bisphosphate carboxylase oxygenase small subunit, and water stress-related genes, such as abscisic stress ripening protein, were the most abundant in cDNAs from leaves of V. coignetiae infected with Elsinoe ampelina. These data could provide useful information in the genetic analysis of V. coignetiae and in the program for breeding disease-resistant grape cultivars.

[CF-0002] Transcriptional analysis of differentially expressed genes related with disease resistance in Vitis species for grape breeding

Hae Keun Yun(Hae Keun Yun),Soon Young Ahn(Soon Young Ahn),Hae In Lee(Hae In Lee),Youn Young Hur(Youn Young Hur) 한국육종학회 2022 한국육종학회 공동학술발표집 Vol.2022 No.-

Human adipose tissue-derived mesenchymal stem cells inhibit melanoma growth in vitro and in vivo.

Ahn, Jin-Ok,Coh, Ye-Rin,Lee, Hee-Woo,Shin, Il-Seob,Kang, Sung-Keun,Youn, Hwa-Young Potamitis Press 2015 Anticancer research Vol.35 No.1

<P>The effects of adipose tissue-derived mesenchymal stem cells (AT-MSCs) on the growth of human malignancies, including melanoma, are controversial and the underlying mechanisms are not yet-well understood. The aim of the present study was to investigate the in vitro and in vivo anti-tumor effects of human AT-MSCs on human melanoma.</P>

Software certification of safety-critical avionic systems: DO-178C and its impacts

Won Keun Youn,Seung Bum Hong,Kyung Ryoon Oh,Oh Sung Ahn IEEE 2015 IEEE aerospace and electronic systems magazine Vol.30 No.4

<P>This article presents an overview of the new guidelines for safety-critical airborne software contained in DO-178C and supplementary documents. The similarity between DO178B and DO-178C is presented by reviewing the basics of DO178 verification philosophy, and an overview of the major new guidance in DO-178C is presented to highlight what has been changed, along with a description of the impact of DO-178C on the industry. The remaining sections of the article provide a discussion of the new guidelines in the supplementary documents: DO-330 to DO-333.</P>

Sub-Halfmicron Lithography Using an I-line Modified Illumination Techniques

Lee, Youn suk,Moon, Seung Chan,Won, Tai Kyung,Lee, Jung Hwan,Kim, Hyeong Soo,Kim, Keun Young,Ahn, Dong Jun,Choi, Soo Han 대한전자공학회 1993 ICVC : International Conference on VLSI and CAD Vol.3 No.1

In this study we have investigated the effect of modified illumination techniques tv extend process limitations of an I-line in the sub-halfmicron region. The modified illumination using quadrupole or annular shape aperture can be alternative rv conventional illumination, regardless rf the, exposure wavelength ire an optical lithography. As a result resolution was improved about 20%, and over 90% DOF at the periodic pattern of 0.4㎛ compared to conventional illumination with a coherence value of 0.6. The auxiliary pattern for the isolated pattern has been demonstrated to be very helpful for an improvement of DOF and resist pattern profile. And 0.25㎛ pattern delineation which has a 1.5㎛ DOF with a vertical profile was obtained using annular illumination combined with the PS process.

HFC 망에서 상향채널의 충돌해결 알고리즘 성능비교

이수연,안종근 순천향대학교 부설 산업기술연구소 1998 순천향 산업기술연구소논문집 Vol.3 No.3

We introduced the methods of a DAVIC and IEEE 802.14 of the Medium Access Control Protocols in order to the two directions a CATV network based on HFC and proposed a new direction by the performance comparison about collision resolution algorithms that resolve an occurrent collision over an upstream channel in their protocols.