IR 영상 내의 이동 물체 추출 ( Extraction of the Moving Object in IR image )

류정묵,박길흠 한국통신학회 1997 한국통신학회 학술대회논문집 Vol.16 No.1

수정체 상피 세포주에서 glucocorticoid 에 의한 alpha - crystallin 유전자발현조절에 관한 연구

류정묵(Jung Mook Lyu),황은주(Eun Joo H.),이도형(Do Hyung Lee),주천기(Choun Ki Joo),김재호(Jae Ho Kim),정성근(Sung Kun Jung) 대한안과학회 2001 대한안과학회지 Vol.42 No.10

Association between Axial Length and Anthropometric Value in Korean Children

김효진,류정묵 한국안광학회 2014 한국안광학회지 Vol.19 No.3

To investigate the relationship between axial length (AL) and anthropometric parameters in Korean children. Methods: This study included 40 urban school children aged 11-12 years (mean age, 11.95±0.22 years; 45.0% girls)residing in Seoul, South Korea. AL (using partial coherence laser interferometry), corneal radius, refractive error, height(m), and weight (kg) were measured. Body mass index (BMI [kg/m2]=weight/[height]2) and degree of obesity(DO[%]=[actual weight standard weight]/standard weight) were calculated. Furthermore, the number of hours spentreading, watching television, and using a computer every day was determined using a detailed questionnaire. Results: Thestudents had a mean spherical equivalent refraction of 1.06±0.84 D. Weight (r=0.427, p=0.006), BMI (r=0.508, p=0.001),and DO (r=0.371, p=0.018) showed a significant positive correlation with AL. Furthermore, longer AL was significantlyassociated with heavier weight (p=0.041), and higher BMI (p=0.015), and higher DO quartiles (p=0.042). After adjust forage, sex, and near-work activities, multivariate linear regression models showed that weight, BMI, and DO were stillsignificantly associated with AL. Among the near-work activities, daily reading time was significantly associated with AL. Conclusions: AL was positively related to weight as well as daily reading time in Korean urban school children.

청색광에 의한 마우스 망막손상에서 선택적 광수용세포의 사멸

강서영,홍지은,최은정,류정묵 한국안광학회 2016 한국안광학회지 Vol.21 No.1

Purpose: The study was conducted to determine that photoreceptors of mouse having pigment in RPE(retinal pigment epithelium) can be damaged by blue-light and apoptosis of specific cells among photoreceptors are induced by blue-light, and to assist the investigation of AMD(Age-related macular degeneration) mechanisms and development of AMD drugs. Methods: C57Black mice were injured by irradiating 2800±10 lux of 463 nm LED for 6 hours after 24 hours dark adaptation and eyes were enucleated 1, 3, 7 days. Damage of retina induced by blue-light was determined by western blotting GFAP(Glial fibrillary acidic protein) expression. In the light-injured retina, cell death of photoreceptors was determined by TUNEL(Terminal deoxynucleotidyl transferase dUTP nick end labeling) assay. ERK(Extracellular signalregulated kinases), JNK, and SRC(sarcoma) expression were assessed by western blotting to determine regulated pathway. Blue light-injured retina were immunostained with antibodies against Opsin and Rhodopsin as markers of photoreceptors to compared the damage cone cells with rod cells. Results: After 1, 3 and 7 days from exposure to bluelight, thickness of retina was more decreased than control, and more decreased at nuclear layer than at outer plexiform layer and GFAP expression was increased day 1 after blue-light injured. While phosphorylated ERK and SRC protein expressions at day 1 were increased after blue-light injured, phosphorylated c-JUN was decreased. Fluorescence intensity analysis showed that markers of cone and rod cells were decreased after blue-light injured and Opsin was more decreased than Rhodopsin. Conclusions: The study suggests possibilities that the blue-light promotes retinal damage and causes apoptotic cell death via ERK and SRC pathway in mouse retina, and blue-light retinal damage is more induced cone cells apoptosis than rod cells directly. 목적: 본 연구는 망막색소상피층에 색소가 존재하는 mouse에서 청색광으로 인해 광수용세포 손상이 일어날 수 있는지 확인하고, 광수용세포 중 특이적 세포에서 세포사멸이 유도되는지 조사하여 청색광에 의해 야기될 수 있는 연령관련황반변성의 기전 규명과 치료제 개발에 도움이 되고자 진행되었다. 방법: C57black mice를 24시간 암순응 시켜 463 nm의청색광을 2800±10 lux로 조사한 후 1일, 3일, 7일째에 안구를 적출하였다. 청색광의 자극은 GFAP(Glial fibrillary acidic protein)단백질의 발현을 이용하여 확인하였고, 광수용세포의 세포사멸은 TUNEL(Terminal deoxynucleotidyl transferase dUTP nick end labeling)을 사용하여 분석하였다. Western blotting으로 ERK(Extracellular signal-regulated kinases), c- JUN, SRC(Sarcoma) 단백질 발현을 확인하였고, 막대세포와 원뿔세포의 손상 정도를 비교하기 위해 면역염색으로분석하였다. 결과: 청색광을 조사한 후 1, 3, 7일이 지난 망막은 대조군 보다 전체적으로 두께가 감소하였고, 각 얼기층보다 핵층에서 두께 감소를 확인할 수 있었다. 또한 청색광을 조사한 후 1일 지난 Muller glia에서 GFAP 단백질이 증가하는 것을 확인하였다. TUNEL 염색에서는 청색광을 조사한 후 1일 지난 망막의 광수용세포에서 가장 많은 발현을 보였다. 세포사멸 기전 과정 중 하나임을 확인하기 위해 ERK, c-JUN, SRC 단백질 활성을 확인한 결과청색광을 조사한 망막에서 phosphorylated ERK는 증가하였고 phosphorylated SRC는 조사 후 1일에서만 증가를 나타내었으며, 반대로 phosphorylated c-JUN은 조사 후 1일에서만 감소하였다. 청색광을 조사한 망막에서 막대세포 발색단인 로돕신과 원뿔세포의 발색단인 옵신이 감소하였으며, 옵신의 감소량은 로돕신의 감소량보다 큰 것을 확인하였다. 결론: 본 연구는 청색광이 망막에 손상자극을 주고, ERK와 SRC 신호전달과 관련하여 광수용세포의 세포사멸을 일으킬 수 있으며 청색광이 광수용세포 중 원뿔세포의 세포사멸을 직접적으로 유도하여 망막 손상을 야기할수 있다는 가능성을 제시하였다.

Ryk modulates the niche activity of mesenchymal stromal cells by fine-tuning canonical Wnt signaling

Seon-Yeong Jeong,류정묵,김진아,오일환 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

The importance of modulating the intensity of Wnt signaling has been highlighted in various biological models, but their mechanisms remain unclear. In this study, we found that Ryk—an atypical Wnt receptor with a pseudokinase domain—has a Wnt-modulating effect in bone marrow stromal cells to control hematopoiesis-supporting activities. We first found that Ryk is predominantly expressed in the mesenchymal stromal cells (MSCs) of the bone marrow (BM) compared with hematopoietic cells. Downregulation of Ryk in MSCs decreased their clonogenic activity and ability to support self-renewing expansion of primitive hematopoietic progenitors (HPCs) in response to canonical Wnt ligands. In contrast, under high concentrations of Wnt, Ryk exerted suppressive effects on the transactivation of target genes and HPC-supporting effects in MSCs, thus fine-tuning the signaling intensity of Wnt in BM stromal cells. This ability of Ryk to modulate the HPC-supporting niche activity of MSCs was abrogated by induction of deletion mutants of Ryk lacking the intracellular domain or extracellular domain, indicating that the pseudokinase-containing intracellular domain mediates the Wnt-modulating effects in response to extracellular Wnt ligands. These findings indicate that the ability of the BM microenvironment to respond to extracellular signals and support hematopoiesis may be fine-tuned by Ryk via modulation of Wnt signaling intensity to coordinate hematopoietic activity.

거짓시신경유두로 보이는 맥락망막결손 증례들의 시야 양상

김서연,진선영,김재훈,류정묵,정재훈 대한안과학회 2020 대한안과학회지 Vol.61 No.7

Purpose: We report three cases of asymptomatic pseudo-optic discs in chorioretinal colobomas highlighted on visual fields patterns. Case summary: (Case 1) A 36-year-old man was found to have a pseudo-optic disc below the optic nerve with a relatively intact neurosensory retina over the lesion. There were no obvious abnormalities on the visual field test, so he underwent no treatment and was followed up every 6 months. (Case 2) A 37-year-old woman diagnosed with glaucoma had abrupt convergence of the neurosensory retinal layers on the boundary of the pseudo-optic disc and a focal retinal nerve fiber layer defect in the inferior sector. An antiglaucoma eyedrop was used to manage the superior hemifield defect, and no significant progression was observed in the structural and functional tests during the 5-year follow-up. (Case 3) A 57-year-old man had a pseudo-optic disc with diffuse retinal nerve fiber layer atrophy in both the superior and inferior sectors. The pseudo-optic disc had protruded into the vitreous cavity. Antiglaucoma eyedrops were used to manage both the superior and inferior hemifield defects, and no significant progression was observed using the structural and functional tests during the 6-year follow-up period. Conclusions: Various visual field results may occur with pseudo-optic discs in chorioretinal colobomas depending on the status of residual retinal tissues and underlying glaucoma. Further evaluations and management options should be considered according to the patient’s condition. 목적: 우연히 발견된 거짓시신경유두로 보이는 맥락망막결손 증례들의 시야 결과를 포함한 임상양상에 대해 보고하고자 한다. 증례요약: (증례 1) 우연히 거짓시신경유두가 발견된 36세 남자로, 비교적 온전하게 사이막으로 이어지는 신경감각망막이 관찰되었고, 시야측정에서 뚜렷한 이상 소견이 보이지 않아 특별한 치료 없이 경과 관찰하기로 하였다. (증례 2) 녹내장 진단받은 37세 여자로 거짓시신경유두와 병변부위 신경감각망막의 급격한 모임 및 아래쪽 영역 망막신경섬유층결손이 관찰되었다. 위쪽 반시야 결손이 보여 안압하강제를 사용하였고, 5년 경과 관찰 기간 동안 뚜렷한 진행 소견은 관찰되지 않았다. (증례 3) 시신경 아래쪽 거짓시신경유두가 위, 아래 영역의 광범위한 망막신경섬유층 위축과 동반된 57세 남자로 병변 부위가 유리체강내로 돌출되었다. 위, 아래쪽 모두시야 결손이 보여 안압하강제를 사용하였고 6년 경과 관찰 기간 동안 뚜렷한 진행 소견은 관찰되지 않았다. 결론: 거짓시신경유두로 보이는 맥락망막결손증에서 맥락망막 조직 결손 정도와 잔류 망막 상태 및 동반된 녹내장에 따라 다앙한 시야결과가 나타날 수 있으므로 상태에 따른 검사 및 치료를 고려해야 한다.

지리정보체계를 이용한 눈 건강수준의 시각적 분포도

김효진,김희진,박창원,이은희,김희주,류정묵 한국안광학회 2014 한국안광학회지 Vol.19 No.4

This study utilized the Geographic Information System (GIS) which is one of the representativemethods for describing visual distribution, to show the distribution of visions of middle and high school studentsin 16 cities or provinces in Korea. Method: The data of National Health and Nutrition Examination Survey(NHANES) were analysed from 2009 to 2011 and designed a population-based cross-sectional study. The subjectswere total 1,049 students at the age of 13 to 18 and uncorrected vision was provided. Male subjects were 549(52.3%) and female subjects were 500 (47.7%). Subjects were divided into 16 cities or provinces and averagevision of regions were analysed. the differentials of vision among the regions were analysed by as a spatialanalysis method. Results: The average uncorrected vision were significant difference by sex (p=0.001). Howevermale and female student groups' average vision indicated no statistically significant difference by region in those16 cities and provinces. In order to show the differentials of middle and high school students' vision by regionwith a visual distribution method, the GIS was utilized for mapping. Conclusions: The differentials of visionamong regions by GIS provide a visually effective distribution map. 한국 중고등학생을 대상으로 전국 16개 시도의 지역별 시력 분포를 나타내는데 대표적인 시각적 분포기법인 지리정보체계(geographic information system, GIS)를 활용하였다. 방법: 2009년부터 2011년도의 국민건강영양조사(NHANES)의 자료를 이용하여 인구 기반 단면 연구로 디자인하였다. 나안시력의 정보가 제공된 만 13~18세의 총1,049명을 대상으로 하였고, 남자가 549명(52.3%), 여자가 500명(47.7%) 이었다. 지역은 전국을 16개 시도로 구분하였고, 각 지역별 평균 시력을 활용하였다. 공간분석 방법으로 GIS 기법을 활용하여 지역별 시력수준의 격차를 나타내었다. 결과: 연구 대상자의 평균 나안시력은 성별에 따라 유의한 차이를 보였다(p=0.001). 지역별 남학생과 여학생 그룹의 평균 시력은 16개 시도에서 통계적으로 유의한 차이가 없었다. 중고등학생의 지역별 시력 격차를 시각적 분포기법으로 나타내고자 GIS를 이용하여 지도화 하였다. 결론: 지역별 시력의 격차를 나타내는데 GIS 기법은시각적으로 효과적인 분포도를 제공하였다.

LED 조명에 대한 청색광 위험 평가

정명훈,양석준,육주성,오상영,김창진,류정묵,최은정 한국안광학회 2015 한국안광학회지 Vol.20 No.3

Purpose: To evaluate blue light hazards of LED lightings in an optical store with blue light radiance used as the quantitative indicators of photobiological hazard. Methods: The spectral radiance of each LED lightings was measured, and blue-light radiance and the corresponding maximum exposure time were calculated. Then each LED lighting was classified according to the risk group from IEC 62471 standard. Results: The yellow LED lightings used in showcases and white LED lightings used on ceilings and logo were classified into risk group RG0. But the white LED lightings used on showcases were classified into risk group RG1. The blue light radiances of white LED lightings used in showcases are dozens of times larger than that of fluorescent lamp. Conclusions: Using the value of the blue light radiance could quantitatively express the blue light hazard to various lightings. It was confirmed that white LED lightings for the showcases had high blue light hazards because of their high luminance and color temperature. Therefore, when replacing lightings in optical shop it is necessary to select the appropriate brightness and color temperature for eye health in the long term. 목적: 청색광 위험도의 정량적 지표인 청색광 복사휘도를 이용하여 안경원 내 LED 조명에 대한 청색광 위험도를평가하였다. 방법: LED 조명의 분광복사휘도를 측정하고 청색광 복사휘도와 최대노출시간을 산출한 후, IEC 62471 분류기준에 따라 위험군을 분류하였다. 결과: 진열장에 사용된 황색 LED 조명, 천장에 사용된 백색 및 황색 LED 조명, 그리고 로고에 사용된 백색 LED 조명은 위험제외군 RG0로 분류되었지만, 진열장에 사용된 백색 LED 조명은 위험군RG1으로 분류되었다. 진열장에 사용된 백색 LED 조명의 청색광 복사휘도는 형광등에 비하여 수십 배나 높은 것으로나타났다. 결론: 청색광 복사휘도의 값을 이용하여 여러 가지 조명에 대한 청색광 위험을 정량적으로 표현할 수 있었다. 진열장용 백색 LED 조명은 높은 휘도와 색온도로 청색광 위험이 높음을 확인할 수 있었으며, 안경원 내의 조명 교체 시 장기적이 측면에서 시건강을 위해 적절한 밝기와 색온도의 조명을 선택하는 것이 필요하겠다.

Sestrin2 inhibits YAP activation and negatively regulates corneal epithelial cell proliferation

Ji-Su Lee,박환우,조경진,류정묵 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

Corneal wound healing is essential for the maintenance of corneal integrity and transparency and involves a series of physiological processes that depend on the proliferation of epithelial cells. However, the molecular mechanisms that control corneal epithelial cell proliferation are poorly understood. Here, we show that Sestrin2, a stress-inducible protein, is downregulated in the corneal epithelium during wound healing and that the proliferation of epithelial basal cells is enhanced in Sestrin2-deficient mice. We also show that YAP, a major downstream effector of the Hippo signaling pathway, regulates cell proliferation during corneal epithelial wound repair and that Sestrin2 suppresses its activity. Moreover, increased levels of reactive oxygen species in the Sestrin2-deficient corneal epithelium promote the nuclear localization and dephosphorylation of YAP, activating it to enhance the proliferation of corneal epithelial cells. These results reveal that Sestrin2 is a negative regulator of YAP, which regulates the proliferative capacity of basal epithelial cells, and may serve as a potential therapeutic target for corneal epithelial damage.

Photobiomodulation therapy activates YAP and triggers proliferation and dedifferentiation of Müller glia in mammalian retina

Seo-Yeon Kim,Myung-Jun Song,In-Beom Kim,Tae Kwan Park,류정묵 생화학분자생물학회 2023 BMB Reports Vol.56 No.9

Photobiomodulation therapy has been proposed as a promisingtherapeutic approach for retinal degenerative diseases. However,its effect on the regenerative capacity in mammalian retina andits intracellular signalling mechanisms remain unknown. Here,we show that photobiomodulation with 670 nm light stimulatesMüller glia cell cycle re-entry and dedifferentiation into aprogenitor-like state in both the uninjured and injured retina. We also find that 670 nm light treatment inhibits the Hippopathway, which is activated in Müller glia following NaIO3-induced retinal injury. YAP, a major downstream effector ofthe Hippo signalling pathway was translocated into the nucleusof Müller glia along with YAP dephosphorylation in retinatreated with 670 nm light. Deficiency of YAP attenuated Müllerglia cell cycle re-entry and dedifferentiation. Our data revealthat the Hippo-YAP signalling pathway is associated with thephotostimulatory effect on regenerative response in mammalianretina, and suggest a potential therapeutic strategy for retinaldegenerative diseases.