• BMB Reports
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• v.51 no.3
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• pp.157-162
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• 2018

Angiogenesis is a complex, multistep process involving dynamic changes in endothelial cell (EC) shapes and behaviors, especially in specialized cell types such as tip cells (with active filopodial extensions), stalk cells (with less motility) and phalanx cells (with stable junction connections). The Hippo-Yes-associated protein (YAP)/ transcription activator with PDZ binding motif (TAZ) signaling plays a critical role in development, regeneration and organ size by regulating cell-cell contact and actin cytoskeleton dynamics. Recently, with the finding that YAP is expressed in the front edge of the developing retinal vessels, Hippo-YAP/TAZ signaling has emerged as a new pathway for blood vessel development. Intriguingly, the LATS1/2-mediated angiomotin (AMOT) family and YAP/TAZ activities contribute to EC shapes and behaviors by spatiotemporally modulating actin cytoskeleton dynamics and EC junction stability. Herein, we summarize the recent understanding of the role of Hippo-YAP/TAZ signaling in the processes of EC sprouting and junction maturation in angiogenesis.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.64-69
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• 1998

This paper presents a lip print recognition by the pattern kernels for a personal identification. A lip print recognition is developed less than the other physical attributes of a fingerprint, a voice pattern, a retinal blood/vessel pattern, or a facial recognition. A new method is proposed to recognize a lip print bi the pattern kernels. The pattern kernels are a function consisted of some local lip print pattern masks. This function converts the information on a lip print into the digital data. The recognition in the multi-resolution system is more reliable than recognition in the single-resolution system. The results show that the proposed algorithm by the multi-resolution architecture can be efficiently realized.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.902-906
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• 2000

망막 혈관 구조의 분석은 망막에 관련된 환자의 진단 및 치료에 중요한 정보를 제공하기 때문에 다양한 연구가 진행되어 왔다. 본 연구에서는 ICG(IndoCyanine Green) 기술을 이용한 망막 영상의 혈관 구조를 분석하기 위해 원의 방정식으로 묘사된 혈관 영역 에너지 함수와 분기점 추정 템플릿을 사용하여 혈관의 특징점들을 추정한 후 혈관의 형체(body)를 자동으로 추적하는 동시에 분기점을 추출하는 방법을 제안한다. 전체 혈관의 자동추적과 분기점 추출을 가능하게 하는 특징점 추정 방법과 혈관 형체의 자동추적 알고리즘 및 분기점 추출 방법을 ICG 망막 영상에 적용하여 실험한 결과 만족할 만한 성능을 보였다.

• Journal of Environmental Science International
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• v.18 no.11
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• pp.1247-1259
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• 2009

We investigated the toxic effects of carbaryl on early embryo development in the African clawed frog, Xenopus laevis. To test the toxic effects, frog embryo teratogenesis assays using Xenopus were performed. Embryos were exposed to various concentrations of carbaryl ($5{\sim}320\;{\mu}M$). $LC_{100}$ for carbaryl was $320\;{\mu}M$, and the $LC_{50}$ determined by probit analysis was the concentration of $235.68\;{\mu}M$. Exposure to $160\;{\mu}M$ of carbaryl resulted in 10 different types of severe external malformations. Histological examination revealed dysplasia of the eyes, heart, guts, somatic muscle, dorsal, liver, blood vessel and swelling of the pronephric ducts. Malformation of neural tissue and brain was not severe even in the high dose of carbaryl. Benzidine blood stain showed distinct inhibition of inducing erythrocytes in embryos and animal cap explants. Electron micrographs of embryo revealed retinal detachment, loose photoreceptor lamella and the degeneration of sarcomeres in the carbaryl-treated group. The mitochondrial degeneration was also observed in the test group.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12A
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• pp.2067-2073
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• 2001

Biometric systems are forms of technology that use unique human physical characteristics to automatically identify a person. They have sensors to pick up some physical characteristics, convert them into digital patterns, and compare them with patterns stored for individual identification. However, lip-print recognition has been less developed than recognition of other human physical attributes such as the fingerprint, voice patterns, retinal at blood vessel patterns, or the face. The lip print recognition by a CCD camera has the merit of being linked with other recognition systems such as the retinal/iris eye and the face. A new method using multi-resolution architecture is proposed to recognize a lip print from the pattern kernels. A set of pattern kernels is a function of some local lip print masks. This function converts the information from a lip print into digital data. Recognition in the multi-resolution system is more reliable than recognition in the single-resolution system. The multi-resolution architecture allows us to reduce the false recognition rate from 15% to 4.7%. This paper shows that a lip print is sufficiently used by the measurements of biometric systems.

• Progress in Medical Physics
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• v.2 no.2
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• pp.183-192
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• 1991

Ophthalmoscopy following the intravenous injection of fluorescein has gained great diagnostic importance in ophthalmology. This technique provides sequential evaluation of the anatomic and physiologic status of the choroidal and retinal vasculature. In order to detect the changes between fluorescein ocular fundus image frames, the direct subtraction of the two frames is inadequate because of geometric distortions and background gray level differences in two images. In this study, a scheme for the correction of the geometric distortions is proposed. Precise control point coordinate values for transformation functions are manually determined after the process including a series of blood vessel detection and thinning, and one frame is mapped to another, and then a geometric distortion corrected image is obtained. When the corrected image is used in interframe change detections, a sucessful result is ensured.

• Parasites, Hosts and Diseases
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• v.56 no.2
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• pp.135-145
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• 2018

Due to the critical location and physiological activities of the retinal pigment epithelial (RPE) cell, it is constantly subjected to contact with various infectious agents and inflammatory mediators. However, little is known about the signaling events in RPE involved in Toxoplasma gondii infection and development. The aim of the study is to screen the host mRNA transcriptional change of 3 inflammation-related gene categories, PI3K/Akt pathway regulatory components, blood vessel development factors and ROS regulators, to prove that PI3K/Akt or mTOR signaling pathway play an essential role in regulating the selected inflammation-related genes. The selected genes include PH domain and leucine- rich-repeat protein phosphatases (PHLPP), casein kinase2 (CK2), vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), glutamate-cysteine ligase (GCL), glutathione S-transferase (GST), and NAD(P)H: quinone oxidoreductase (NQO1). Using reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), we found that T. gondii up-regulates PHLPP2, $CK2{\beta}$, VEGF, GCL, GST and NQO1 gene expression levels, but down-regulates PHLPP1 and PEDF mRNA transcription levels. PI3K inhibition and mTOR inhibition by specific inhibitors showed that most of these host gene expression patterns were due to activation of PI3K/Akt or mTOR pathways with some exceptional cases. Taken together, our results reveal a new molecular mechanism of these gene expression change dependent on PI3K/Akt or mTOR pathways and highlight more systematical insight of how an intracellular T. gondii can manipulate host genes to avoid host defense.