• 제목/요약/키워드: Retinal diseases

검색결과 72건 처리시간 0.019초

결절성 경화증에 동반된 폐의 임파관평활근종증 2예 (Two Cases of Pulmonary Lymphangioleiomyomatosis Associated with Tuberous Sclerosis)

  • 안정천;조원용;인광호;강경호;유세화
    • Tuberculosis and Respiratory Diseases
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    • 제39권6호
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    • pp.542-547
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    • 1992
  • 결절성경화증과 동반된 폐임파관평활근종증은 매우 드문 질환으로서 가임기의 여성에게 국한되어 발생한다. 저자들은 결절성경화증이 있던 39세의 여자 환자에게서 반복되는 자연기흉으로 폐조직 생검결과 폐임파관 평활근종증으로 확진된 예와 양측신 혈관근지반종을 동반한 결절성 경화증을 갖은 32세 여자 환자에서 호흡기 증상은 없었으나 흉부 X-선 및 고해상도 흉부 컴퓨터 단층 촬영상 폐임파관 평활근종증을 보였던 예를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

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Maturation-Resistant Dendritic Cells Ameliorate Experimental Autoimmune Uveoretinitis

  • Oh, Keun-Hee;Kim, Yon-Su;Lee, Dong-Sup
    • IMMUNE NETWORK
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    • 제11권6호
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    • pp.399-405
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    • 2011
  • Background: Endogenous uveitis is a chronic inflammatory eye disease of human, which frequently leads to blindness. Experimental autoimmune uveoretinitis (EAU) is an animal disease model of human endogenous uveitis and can be induced in susceptible animals by immunization with retinal antigens. EAU resembles the key immunological characteristics of human disease in that both are $CD4^+$ T-cell mediated diseases. Dendritic cells (DCs) are specialized antigen-presenting cells that are uniquely capable of activating naive T cells. Regulation of immune responses through modulation of DCs has thus been tried extensively. Recently our group reported that donor strain-derived immature DC pretreatment successfully controlled the adverse immune response during allogeneic transplantation. Methods: EAU was induced by immunization with human interphotoreceptor retinoid-binding protein (IRBP) $peptide_{1-20}$. Dendritic cells were differentiated from bone marrow in the presence of recombinant GM-CSF. Results: In this study, we used paraformaldehyde-fixed bone marrow-derived DCs to maintain them in an immature state. Pretreatment with fixed immature DCs, but not fixed mature DCs, ameliorated the disease progression of EAU by inhibiting uveitogenic $CD4^+$ T cell activation and differentiation. Conclusion: Application of iBMDC prepared according to the protocol of this study would provide an important treatment modality for the autoimmune diseases and transplantation rejection.

Optical Design of a Snapshot Nonmydriatic Fundus-imaging Spectrometer Based on the Eye Model

  • Zhao, Xuehui;Chang, Jun;Zhang, Wenchao;Wang, Dajiang;Chen, Weilin;Cao, Jiajing
    • Current Optics and Photonics
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    • 제6권2호
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    • pp.151-160
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    • 2022
  • Fundus images can reflect ocular diseases and systemic diseases such as glaucoma, diabetes mellitus, and hypertension. Thus, research on fundus-detection equipment is of great importance. The fundus camera has been widely used as a kind of noninvasive detection equipment. Most existing devices can only obtain two-dimensional (2D) retinal-image information, yet the fundus of the human eye also has spectral characteristics. The fundus has many pigments, and their different distributions in the eye lead to dissimilar tissue penetration for light waves, which can reflect the corresponding fundus structure. To obtain more abundant information and improve the detection level of equipment, a snapshot nonmydriatic fundus imaging spectral system, including fundus-imaging spectrometer and illumination system, is studied in this paper. The system uses a microlens array to realize snapshot technology; information can be obtained from only a single exposure. The system does not need to dilate the pupil. Hence, the operation is simple, which reduces its influence on the detected object. The system works in the visible and near-infrared bands (550-800 nm), with a volume less than 400 mm × 120 mm × 75 mm and a spectral resolution better than 6 nm.

Nrf2-mediated activation of HO-1 is required in the blocking effect of compound K, a ginseng saponin metabolite, against oxidative stress damage in ARPE-19 human retinal pigment epithelial cells

  • Cheol Park;Hee-Jae Cha;Kyoung-Seob Song;Heui-Soo Kim;EunJin Bang;Hyesook Lee;Cheng-Yun Jin;Gi-Young Kim;Yung Hyun Choi
    • Journal of Ginseng Research
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    • 제47권2호
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    • pp.311-318
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    • 2023
  • Background: The beneficial effects of compound K (CK) on different chronic diseases have been shown to be at least related to antioxidant action. Nevertheless, since its antioxidant activity in human retinal pigment epithelial (RPE) cells is still unknown, here we investigated whether CK alleviates oxidative stress-stimulated damage in RPE ARPE-19 cells. Methods: The cytoprotective consequence of CK in hydrogen peroxide (H2O2)-treated cells was evaluated by cell viability, DNA damage, and apoptosis assays. Fluorescence analysis and immunoblotting were performed to investigate the inhibitory action of CK on reactive oxygen species (ROS) production and mitochondrial dysfunction. Results: H2O2-promoted cytotoxicity, oxidative stress, DNA damage, mitochondrial impairment, and apoptosis were significantly attenuated by CK in ARPE-19 cells. Furthermore, nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation level and its shuttling to the nucleus were increased, which was correlated with upregulated activation of heme oxygenase-1 (HO-1). However, zinc protoporphyrin, a blocker of HO-1, significantly abrogated the preventive action of CK in H2O2-treated ARPE-19 cells. Conclusion: This study indicates that activation of Nrf2/HO-1 signaling by CK plays an important role in rescuing ARPE-19 cells from oxidative cellular damage.

Power-Efficient Wireless Neural Stimulating System Design for Implantable Medical Devices

  • Lee, Hyung-Min;Ghovanloo, Maysam
    • IEIE Transactions on Smart Processing and Computing
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    • 제4권3호
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    • pp.133-140
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    • 2015
  • Neural stimulating implantable medical devices (IMDs) have been widely used to treat neurological diseases or interface with sensory feedback for amputees or patients suffering from severe paralysis. More recent IMDs, such as retinal implants or brain-computer interfaces, demand higher performance to enable sophisticated therapies, while consuming power at higher orders of magnitude to handle more functions on a larger scale at higher rates, which limits the ability to supply the IMDs with primary batteries. Inductive power transmission across the skin is a viable solution to power up an IMD, while it demands high power efficiencies at every power delivery stage for safe and effective stimulation without increasing the surrounding tissue's temperature. This paper reviews various wireless neural stimulating systems and their power management techniques to maximize IMD power efficiency. We also explore both wireless electrical and optical stimulation mechanisms and their power requirements in implantable neural interface applications.

메밀의 Rutin 및 기능성 물질의 종류와 변이 (Rutin and Functional Ingredients of Buckwheat and Their Variations)

  • 최병한;김선림;김성국
    • 한국작물학회지
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    • 제41권spc1호
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    • pp.69-93
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    • 1996
  • In Korea, buckwheat has historically held a very important position because it has been used as a food and traditional medicine. The objectives of this report were to mainly review the up to present papers includings 75 references about buckwheat's rutin, functional ingredients and their variations. Buckwheat provides an abundance of such nutrition as protein, amino acids, vitamin($B_1,\;B_2$, E, P), minerals(Fe, Zn, Mn, Mg, P, Cu, Ca, Se) and dietary fiber. Buckwheat's essential amino acid, lysine, is notably higher amount than cereals. Rutin(vitamin P), one of a group of flavonoids, is abundant in buckwheat and noted for its beneficial function of reducing every kinds of radiation and vascular diseases, diabetes mellitis and retinal hemorrhage, etc. Rutin also acts as a pigment stabilizer and acetone extracts of buckwheat have a potent tyrosinase inhibitory activity.

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Array-Based Real-Time Ultrasound and Photoacoustic Ocular Imaging

  • Nam, Seung Yun;Emelianov, Stanislav Y.
    • Journal of the Optical Society of Korea
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    • 제18권2호
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    • pp.151-155
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    • 2014
  • Although various ophthalmic imaging methods, including fundus photography and optical coherence tomography, have been applied for effective diagnosis of ocular diseases with high spatial resolution, most of them are limited by shallow imaging penetration depth and a narrow field of view. Also, many of those imaging modalities are optimized to provide microscopic anatomical information, while functional or cellular information is lacking. Compared to other ocular imaging modalities, photoacoustic imaging can achieve relatively deep penetration depth and provide more detailed functional and cellular data based on photoacoustic signal generation from endogenous contrast agents such as hemoglobin and melanin. In this paper, array-based ultrasound and photoacoustic imaging was demonstrated to visualize pigmentation in the eye as well as overall ocular structure. Fresh porcine eyes were visualized using a real-time ultrasound micro-imaging system and an imaging probe supporting laser pulse delivery. In addition, limited photoacoustic imaging field of view was improved by an imaging probe tilting method, enabling visualization of most regions of the retina covered in the ultrasound imaging.

Thickness of the Macula, Retinal Nerve Fiber Layer, and Ganglion Cell-inner Plexiform Layer in the Macular Hole: The Repeatability Study of Spectral-domain Optical Coherence Tomography

  • Lee, Woo Hyuk;Jo, Young Joon;Kim, Jung Yeul
    • Korean Journal of Ophthalmology
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    • 제32권6호
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    • pp.506-516
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    • 2018
  • Purpose: We measured the thicknesses of the ganglion cell and inner plexiform layer (GCIPL), the macula, and the retinal nerve fiber layer (RNFL) using spectral-domain optical coherence tomography in patients with idiopathic macula holes to analyze the repeatability of these measurements and compare them with those of the fellow eye. Methods: We evaluated 85 patients who visited our retinal clinic. The patients were divided into two groups according to their macular hole size: group A had a size of $<400{\mu}m$, while group B had a size of ${\geq}400{\mu}m$. Repeatability was determined by comparing the thicknesses of the GCIPL, macula, and RNFL with those of the normal fellow eye. Results: The average central macular thickness in patients with macular holes was significantly thicker than that in the normal fellow eye ($343.8{\pm}78.6$ vs. $252.6{\pm}62.3{\mu}m$, p < 0.001). The average thickness of the GCIPL in patients with macular holes was significantly thinner than that in the normal fellow eye ($56.1{\pm}23.4$ vs. $77.1{\pm}12.8{\mu}m$, p < 0.001). There was no significant difference in the average RNFL thickness between eyes with macular holes and fellow eyes ($92.4{\pm}10.0$ vs. $95.5{\pm}10.7{\mu}m$, p = 0.070). There were also no significant differences in the thicknesses of the GCIPL and RNFL among the two groups (p = 0.786 and p = 0.516). The intraclass correlation coefficients for the macula and RNFL were 0.994 and 0.974, respectively, in patients with macular holes, while that for the GCIPL was 0.700. Conclusions: Macular contour change with macular hole results in low repeatability and a tendency of thinner measurement regarding GCIPL thickness determined via spectral-domain optical coherence tomography. The impact of changes in the macular shape caused by macular holes should be taken into consideration when measuring the GCIPL thickness in patients with various eye diseases such as glaucoma and in those with neuro-ophthalmic disorders.

Blood-neural Barrier: Intercellular Communication at Glio-Vascular Interface

  • Kim, Jeong-Hun;Kim, Jin-Hyoung;Park, Jeong-Ae;Lee, Sae-Won;Kim, Woo-Jean;Yu, Young-Suk;Kim, Kyu-Won
    • BMB Reports
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    • 제39권4호
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    • pp.339-345
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    • 2006
  • The blood-neural barrier (BNB), including blood-brain barrier (BBB) and blood-retinal barrier (BRB), is an endothelial barrier constructed by an extensive network of endothelial cells, astrocytes and neurons to form functional 'neurovascular units', which has an important role in maintaining a precisely regulated microenvironment for reliable neuronal activity. Although failure of the BNB may be a precipitating event or a consequence, the breakdown of BNB is closely related with the development and progression of CNS diseases. Therefore, BNB is most essential in the regulation of microenvironment of the CNS. The BNB is a selective diffusion barrier characterized by tight junctions between endothelial cells, lack of fenestrations, and specific BNB transporters. The BNB have been shown to be astrocyte dependent, for it is formed by the CNS capillary endothelial cells, surrounded by astrocytic end-foot processes. Given the anatomical associations with endothelial cells, it could be supposed that astrocytes play a role in the development, maintenance, and breakdown of the BNB. Therefore, astrocytes-endothelial cells interaction influences the BNB in both physiological and pathological conditions. If we better understand mutual interactions between astrocytes and endothelial cells, in the near future, we could provide a critical solution to the BNB problems and create new opportunities for future success of treating CNS diseases. Here, we focused astrocyte-endothelial cell interaction in the formation and function of the BNB.

심층 컨볼루션 신경망을 이용한 OCT 볼륨 데이터로부터 AMD 진단 (AMD Identification from OCT Volume Data using Deep Convolutional Neural Network)

  • 권오흠;정유진;송하주
    • 한국멀티미디어학회논문지
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    • 제20권8호
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    • pp.1291-1298
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    • 2017
  • Optical coherence tomography (OCT) is the most common medical imaging device with the ability to image the retina in eyes at micrometer resolution and to visualize the pathological indicators of many retinal diseases such as Age-Related Macular Degeneration (AMD) and diabetic retinopathy. Accordingly, there have been research activities to analyze and process OCT images to identify those indicators and make medical decisions based on the findings. In this paper, we use a deep convolutional neural network for analysis of OCT volume data to distinguish AMD from normal patients. We propose a novel approach where images in each OCT volume are grouped together into sub-volumes and the network is trained by those sub-volumes instead of individual images. We conducted an experiment using public data set to evaluate the performance of the proposed approach. The experiment confirmed performance improvement of our approach over the traditional image-by-image training approach.