• Title/Summary/Keyword: Change in occlusion

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The protective effect of methanol extract of Corni Fructus on brain injury caused by unilateral common carotid artery occlusion in mice (산수유(山茱萸) 메탄올 추출물이 편측 경동맥 폐색으로 유도된 생쥐의 허혈성 뇌손상에 미치는 영향)

  • Choi, Na Ri;Jo, Sung Hyeon;Lee, Se-Eun;Lee, Min Ji;Cho, Suin
    • The Korea Journal of Herbology
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    • v.35 no.1
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    • pp.1-8
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    • 2020
  • Objectives : This study was conducted to evaluate the effects of Corni Fructus, the dried fruits of Cornus officinalis Sieb., on unilateral common carotid artery occlusion (UCCAO) in mouse model. Methods : The Corni Fructus used in the experiment was extracted with anhydrous methanol, then filtered and freeze-dried. C57BL/6 mice used in the experiments were conducted left UCCAO surgery to set up UCCAO rodent model for mice. The mice were divided into five groups for evaluate the effect of methanol extract of Corni Fructus (COM) on UCCAO induced ischemic brain injury. The expression levels of nitric oxide in cerebrum and serum, body weight change were measured. To determine the effect of UCCAO and COM administration on brain neurons, morphological changes of the cerebrum through a microscope was conducted. And western blot was performed to confirm the underlying mechanism of neuroprotective effect of COM administration. Results : COM administered UCCAO groups (CO50, CO150, and CO500) had no significant effects on nitric oxide production in ipsilateral hemisphere proteins and sera. The CO500, 500 mg/kg COM administration, attenuated UCCAO-induced p38 inflammatory signaling pathway and inflammatory mediators such as iNOS and COX-2. The CO500 group showed resilient morphological changes of hippocampus neuronal cells about brain damage caused by decreased flow of blood. These group also showed decreased inflammation and cellular stress response in neuronal cells. Conclusions : From these results, COM has a neuroprotective property via moderating inflammatory factors and cellular stress inducing factors in brain cells.

Detection Ability of Occlusion Object in Deep Learning Algorithm depending on Image Qualities (영상품질별 학습기반 알고리즘 폐색영역 객체 검출 능력 분석)

  • LEE, Jeong-Min;HAM, Geon-Woo;BAE, Kyoung-Ho;PARK, Hong-Ki
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.3
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    • pp.82-98
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    • 2019
  • The importance of spatial information is rapidly rising. In particular, 3D spatial information construction and modeling for Real World Objects, such as smart cities and digital twins, has become an important core technology. The constructed 3D spatial information is used in various fields such as land management, landscape analysis, environment and welfare service. Three-dimensional modeling with image has the hig visibility and reality of objects by generating texturing. However, some texturing might have occlusion area inevitably generated due to physical deposits such as roadside trees, adjacent objects, vehicles, banners, etc. at the time of acquiring image Such occlusion area is a major cause of the deterioration of reality and accuracy of the constructed 3D modeling. Various studies have been conducted to solve the occlusion area. Recently the researches of deep learning algorithm have been conducted for detecting and resolving the occlusion area. For deep learning algorithm, sufficient training data is required, and the collected training data quality directly affects the performance and the result of the deep learning. Therefore, this study analyzed the ability of detecting the occlusion area of the image using various image quality to verify the performance and the result of deep learning according to the quality of the learning data. An image containing an object that causes occlusion is generated for each artificial and quantified image quality and applied to the implemented deep learning algorithm. The study found that the image quality for adjusting brightness was lower at 0.56 detection ratio for brighter images and that the image quality for pixel size and artificial noise control decreased rapidly from images adjusted from the main image to the middle level. In the F-measure performance evaluation method, the change in noise-controlled image resolution was the highest at 0.53 points. The ability to detect occlusion zones by image quality will be used as a valuable criterion for actual application of deep learning in the future. In the acquiring image, it is expected to contribute a lot to the practical application of deep learning by providing a certain level of image acquisition.

Alteration of Immunoreactivity for SNARE Proteins in the Rat Hippocampus after Middle Cerebral Artery Occlusion

  • Park, Jung-Sun;Huh, Pil-Woo;Jung, Yeon-Joo;Park, Su-Jin;Lee, Kyung-Eun
    • The Korean Journal of Physiology and Pharmacology
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    • v.8 no.3
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    • pp.141-146
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    • 2004
  • Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) proteins, composed of two presynaptic membrane proteins [synaptosomal-associated protein of 25 kDa (SNAP-25) and syntaxin] and a presynaptic vesicular protein [vesicle-associated membrane protein (VAMP)], serve as a core of exocytotic fusion machinery, which can be affected by ischemia. Synaptic protein in core region, striatum and cortex has been shown to alter after focal ischemia, however, little is known in hippocampus. Hippocampus is remote from ischemic core, but it is one of the most vulnerable regions. Using immunohistochemistry, the present study was undertaken to investigate the alteration of expression of SNAP-25, syntaxin, and VAMP in the hippocampus of rats which were subjected to middle cerebral artery occlusion (MCAO) for 2h and allowed to reperfuse. At 2 weeks of reperfusion, the SNAP-25 and syntaxin immunoreactivity was increased in the stratum oriens of the CA1 and the stratum lucidum of the CA3 in the ipsilateral hippocampus. However, VAMP immunoreactivity didn't show significant change. These results demonstrate that the level of the presynatpic plasma membrane proteins (SNAP-25 and syntaxin) in the rat hippocampus is more sensitively affected by focal ischemia than that of the synaptic vesicle protein (VAMP).

The Effect of Acupuncture in Promoting Neurogenesis and Angiogenesis after Middle Cerebral Artery Occlusion in Rats

  • Lee, Hong Min;Nam, Sang Soo;Kim, Yong Suk
    • Journal of Acupuncture Research
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    • v.30 no.3
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    • pp.1-13
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    • 2013
  • Objectives : This study was performed to choose more effective neuro-protective acupuncture point and to verify the effect of acupuncture in promoting neurogenesis and angiogenesis as a result of its neuro-vasculo-regenerative effect in middle cerebral artery occlusion model in rats. Methods : By TTc staining we chose the most effective acupuncture point with neuro-protection. We randomly divided into four groups: Such as (1) sham group(with sham-operation), (2) sham+acupuncture group(with sham-operation), (3) middle cerebral artery occlusion group, (4) MCAO+AT group. Acupuncture procedure was performed for four days. Total RNA was extracted using TRIzol reagent, according to the manufacturer's instructions, and was purified using an RNAeasy mini kit. Immuno-histochemistry was performed using primary antibody mouse anti-BrdU, NeuN, Dcx, and VEGF. Results : We found that $ST_{36}$ had the more neuroprotective effect than $LI_{11}$ and $SP_3$. The microarray analysis revealed that 54 genes were more expressed neurogenesis pathway in MCAO+AT group compared with MCAO group(fold changes greater than or equal to twofold change). 11 genes were more expressed angiogenesis pathway. And 7 genes were more expressed VEGF pathway. Immuno-histochemistry revealed that cell proliferation, cell migration and cell maturation were increased. Conclusions : This study demonstrated that acupuncture on $ST_{36}$ had neuro-protective and neuro-restorative effect in ischemic brain injuries. And its mechanism might be related to promote neurogenesis and angiogenesis. These results suggest that acupuncture have potential benefits for the treatment of ischemic stroke.

Effect of Gastrodiae Rhizoma on Apoptosis in Cerebral Infarction Induced by Middle Cerebral Artery Occlusion in Rats (천마가 중대뇌동맥 폐쇄 흰쥐의 신경세포 자연사에 미치는 영향)

  • Youn, You-Suk;Lee, Jong-Soo
    • Journal of Korean Medicine Rehabilitation
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    • v.19 no.3
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    • pp.1-13
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    • 2009
  • Objectives : This study evaluates neuroprotective effect of Gastrodiae Rhizoma on apoptosis in the cerebral infarct. Methods : Cerebral infarct was induced by the middle cerebral artery occlusion (MCAO) for 2 hours with intraluminal thread method in Sprague-Dawley rats. Then ethanol extract of Gastrodiae Rhizoma was administered orally for 3 days. Infarct area and volume were evaluated with TTC staining. Neuronal apoptosis was identified with TUNEL labeling. Apoptosis modulatory effect was observed with immunohistochemical Bax, Bcl-2, iNOS, and MMP-9 expressions in penumbra. Results : 1. Ethanol extract of Gastrodiae Rhizoma reduced infarct size partly and volume significantly of in the MCAO rat brain. 2. Ethanol extract of Gastrodiae Rhizoma reduced TUNEL positive cell ratio in the penumbra of MCAO rat brain significantly. 3. Ethanol extract of Gastrodiae Rhizoma suppressed Bax, iNOS and MMP-9 expression in the penumbra of MCAO rat brain significantly. 4. Ethanol extract of Gastrodiae Rhizoma did not change Bcl-2 expression in the penumbra of MCAO rat brain. But expression ratio of Bcl-2 against Bax was increased in the Gastrodiae Rhizoma group. Conclusions : These results suggest that Gastrodiae Rhizoma plays an anti-apoptotic neuroprotective effect through suppression of Bax, iNOS, and MMP-9 expressions and relative up-regulation of Bcl-2 in the ischemic brain tissue.

Differential Expression Patterns of Gangliosides in the Ischemic Cerebral Cortex Produced by Middle Cerebral Artery Occlusion

  • Kwak, Dong Hoon;Kim, Sung Min;Lee, Dea Hoon;Kim, Ji Su;Kim, Sun Mi;Lee, Seo Ul;Jung, Kyu Yong;Seo, Byoung Boo;Choo, Young Kug
    • Molecules and Cells
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    • v.20 no.3
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    • pp.354-360
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    • 2005
  • Neuronal damage subsequent to transient cerebral ischemia is a multifactorial process involving several overlapping mechanisms. Gangliosides, sialic acid-conjugated glycosphingolipids, reduce the severity of acute brain damage in vitro. However their in vivo effects on the cerebral cortex damaged by ischemic infarct are unknown. To assess the possible protective role of gangliosides we examined their expression in the cerebral cortex damaged by ischemic infarct in the rat. Ischemia was induced by middle cerebral artery (MCA) occlusion, and the resulting damage was observed by staining with 2, 3, 5-triphenylterazolium chloride (TTC). High-performance thin-layer chromatography (HPTLC) showed that gangliosides GM3 and GM1 increased in the damaged cerebral cortex, and immunofluorescence microscopy also revealed a significant change in expression of GM1. In addition, in situ hybridization demonstrated an increase in the mRNA for ganglioside GM3 synthase. These results suggest that gangliosides GM1 and GM3 may be synthesized in vivo to protect the cerebral cortex from ischemic damage.

Electrohydraulic Pump-Driven Closed-Loop Blood Pressure Regulatory System

  • Ahn, Jae-Mok
    • Journal of Biomedical Engineering Research
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    • v.28 no.4
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    • pp.449-454
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    • 2007
  • An electrohydraulic (EH) pump-driven closed-loop blood pressure regulatory system was developed based on flow-mediated vascular occlusion using the vascular occlusive cuff technique. It is very useful for investigating blood pressure-dependant physiological variability, in particular, that could identify the principal mediators of renal autoregulation, such as tubuloglomerular feedback (TGF) and myogenic (MYO), during blood pressure regulation. To address this issue, renal perfusion pressure (RPP) should be well regulated under various experimental conditions. In this paper, we designed a new EH pump-driven RPP regulatory system capable of implementing precise and rapid RPP regulation. A closed-loop servo-controlwas developed with an optimal proportional plus integral (PI) compensation using the dynamic feedback RPP signal from animals. An in vivo performance was evaluated in terms of flow-mediated RPP occlusion, maintenance, and release responses. Step change to 80 mmHg reference from normal RPP revealed steady state error of ${\pm}3%$ during the RPP regulatory period after PI action. We obtained rapid RPP release time of approximately 300 ms. It is concluded that the proposed EH RPP regulatory system could be utilized in in vivo performance to study various pressure-flow relationships in diverse fields of physiology, and in particular, in renal autoregulation mechanisms.

Real-time Human Pose Estimation using RGB-D images and Deep Learning

  • Rim, Beanbonyka;Sung, Nak-Jun;Ma, Jun;Choi, Yoo-Joo;Hong, Min
    • Journal of Internet Computing and Services
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    • v.21 no.3
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    • pp.113-121
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    • 2020
  • Human Pose Estimation (HPE) which localizes the human body joints becomes a high potential for high-level applications in the field of computer vision. The main challenges of HPE in real-time are occlusion, illumination change and diversity of pose appearance. The single RGB image is fed into HPE framework in order to reduce the computation cost by using depth-independent device such as a common camera, webcam, or phone cam. However, HPE based on the single RGB is not able to solve the above challenges due to inherent characteristics of color or texture. On the other hand, depth information which is fed into HPE framework and detects the human body parts in 3D coordinates can be usefully used to solve the above challenges. However, the depth information-based HPE requires the depth-dependent device which has space constraint and is cost consuming. Especially, the result of depth information-based HPE is less reliable due to the requirement of pose initialization and less stabilization of frame tracking. Therefore, this paper proposes a new method of HPE which is robust in estimating self-occlusion. There are many human parts which can be occluded by other body parts. However, this paper focuses only on head self-occlusion. The new method is a combination of the RGB image-based HPE framework and the depth information-based HPE framework. We evaluated the performance of the proposed method by COCO Object Keypoint Similarity library. By taking an advantage of RGB image-based HPE method and depth information-based HPE method, our HPE method based on RGB-D achieved the mAP of 0.903 and mAR of 0.938. It proved that our method outperforms the RGB-based HPE and the depth-based HPE.

Effects of (-)-Epigallocatechin-3-gallate on Brain Infarction and the Activity Change of Matrix Metalloproteinase-9 Induced by Middle Cerebral Artery Occlusion in Mice

  • Qian, Yong-Ri;Kook, Ji-Hyun;Hwang, Shin-Ae;Kim, Do-Kyung;Kim, Jong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • v.11 no.3
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    • pp.85-88
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    • 2007
  • Matrix metalloproteinases (MMPs) can degrade a wide range of extracellular matrix components. It has been reported that MMP-9 are activated after focal ischemia in experimental animals. (-)-Epigallocatechin-3-gallate (EGCG), a major constituent of green tea polyphenols, is a potent free radical scavenger and reduces the neuronal damage caused by oxygen free radicals. And it has been known that EGCG could reduce the infarction volume in focal brain ischemia and inhibit MMP-9 activity. To delineate the relationship between the anti-ischemic action and the MMP-9-inhibiting action of EGCG, we investigated the effect of EGCG on brain infarction and the activity of matrix metalloproteinase-9 induced by permanent middle cerebral artery occlusion (pMCAO) in ICR mice. EGCG (40 mg/kg, i.p. $15{\sim}30min$ prior to MCAO) significantly decreased infarction volume at 24 hr after MCAO. GM 6001 (50 mg/kg, i.p. $15{\sim}30min$ prior to MCAO), a MMP inhibitor, also significantly reduced infarction volume. In zymogram, MMP-9 activities began to increase at ipsilateral cortex at 2 hr after MCAO, and the increments of MMP-9 activities were attenuated by EGCG treatment. Western blot for MMP-9 also showed patterns similar to that of zymogram. These findings demonstrate that the anti-ischemic action of EGCG ire mouse focal cerebral ischemia involves its inhibitory effect on MMP-9.

Road Sign Tracking using Affine-AR Model and Robust Statistics (어파인-자기 회귀 모델과 강인 통계를 사용한 교통 표지판 추적)

  • Yoon, Chang-Yong;Cheon, Min-Kyu;Lee, Hee-Jin;Kim, Eun-Tai;Park, Mig-Non
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.5
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    • pp.126-134
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    • 2009
  • This paper describes the vision-based system to track road signs from within a moving vehicle. The proposed system has the standard architecture with particle filter due to its robust tracking performance in complex environment. In the case of tracking road signs in real environment, it has a great difficulty in predicting time series data by reason of an occlusion due to an obstacle and the rapid change of objects on roads. To overcome this problem and improve the tracking performance, this paper proposes the algorithm using an autoregressive model as an state transition model which has affine parameters as states and using robust statistics for determining occlusion due to obstacles. The experiments of this paper show that the proposed method is efficient for real time tracking of road signs and performs well in road signs under occlusion due to obstacles.