• The Korean Journal of Zoology
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• v.37 no.3
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• pp.428-438
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• 1994

HgC12의 투여량에 따른 8일 계배의 대뇌 신경세포 분화에 미치는 영향을 규명하기 위하여 신경세포의 미세구조 변화를 전자현미경을 이용하여 관찰하였으며, 또한 탈수소효소의 활성도 및 ATP의 변화 상을 분석한 결과는 다음과 같다. 대뇌 신경세포의 미세구조의 변화는 0.1mg과 0.5mg 투여 군에서는 핵막이 약간 불규칙하게 관찰되지만 조면소포체와 Golgi복합체가 발달되고 rnltochondria가 다수 관찰되었다 그러나 1.Omg 투여군에서는 조면소포체와 Golgi복합체의 발달이 미약하였으며. 2.Omg 투여군에서는 핵막이 파괴되고 2중막이 분리되었으며, Golgi복합체의 발달이 매우 미약하였다. 탈수소효소 촬성도는 수은의 투여량이 증가할수록 감소하는 현상을 보였는데 LDH의 활성도는 1.Omg투여군이 약간 감소하였고, 2 Omg 투여 군에서는 69n로 크게 감소 현상을 보였다. MDH활성도는 2.Omg투여 군에서 82%로 활성이 감소하는 것으로 나타났다 한편 SDH활성도는 1.Omg투여 군에서 80%. 2.Omg투여군에서는 65%로 활성이 크게 감소하였다. ATP의 변화는 1.Omg투여군 이하에서는 정상군과 유의한 변화는 없으나 2.Omg투여군에서는 크게 증가하는 것으로 나타났다.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.4
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• pp.238-244
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• 2019

In this study, we compared and analyzed the performance of each Convolution Neural Network (CNN) by implementing the CNN that reflected the characteristics of the cerebral structure, in order to analyze the CNN that was used for the prediction of cybersickness, and provided the performance varying depending on characteristics of the brain. Dizziness has many causes, but the most severe symptoms are considered attributable to vestibular dysfunction associated with the brain. Brain waves serve as indicators showing the state of brain activities, and tend to exhibit differences depending on external stimulation and cerebral activities. Changes in brain waves being caused by external stimuli and cerebral activities have been proved by many studies and experiments, including the thesis of Martijn E. Wokke, Tony Ro, published in 2019. Based on such correlation, we analyzed brain wave data collected from dizziness-inducing environments and implemented the dizziness predictive artificial neural network reflecting characteristics of the cerebral structure. The results of this study are expected to provide a basis for achieving optimal performance of the CNN used in the prediction of dizziness, and for predicting and preventing the occurrence of dizziness under various virtual reality (VR) environments.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.175-175
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• 1994

녹용의 유효성분을 분리하기 위하여 지질성분을 분석하고 그 약효를 검색하였다. Folch-Suzuki 분배법, Sephadex G-50, DEAE-Sephadex A-25 Column Chromatography, High Performance Thin Layer Chromatography, HPLC로 정제한후 Mass Spectrometer, NMR, FT-IR등을 이용하여 구조를 분석하였다. 이 물질은 분자량이 1065인 polyhydroxyunsaturated lipid임을 확인하였다. Strepthzotocin으로 당뇨병을 유발시킨 쥐에 이 물질을 투여한 후 혈액과 조직에서 생화학적 변화를 조사하였다. 정상군에 비해 투여군에서 혈당이 감소하였으나 혈액에서 insulin의 양은 증가하지 않았다. 당뇨병 쥐의 적혈구가 정상에 비해 용혈이 되지 않으나 투여군의 적혈구는 정상과 비숫한 용혈현상을 보여 주었다. 대뇌조직에서 gangliosides를 분석한 결과 당뇨병에 의해 GM1이 증가하는 양상을 보여 주었으나 투여군의 경우 대뇌 gangliosides 분포는 정상과 같았다. 대뇌 lipid bound sialic acid를 정량한 결과 당뇨병에 의해 그 양이 감소되었으나 녹용을 투여하였을 때는 정상에 비해 그 양이 더 증가하였다. Strepthzotocin으로 유발시킨 당뇨병 쥐에 녹용의 지질성분을 투여하였을 때 치료효과가 있는 것으로 추정된다.

• The Korean Journal of Zoology
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• v.31 no.3
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• pp.191-206
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• 1988

Chick embryos which have received a single injection of the organophosphate compound,malathion (0.1 mg, 0.5 mg, 1.0 mg or 2.0 mg in 0.05 ml of corn oil) via the yolk sac at certain times (2 daya, 4 days or 6 days after incubation) have been investigated. After 9 days of incubation, chick embryos were harvested to investigate the effects of malathion on the development of cerebrum morphologically and biochemically. The effects of simultaneous injection of malathion and nicotinamide were also compared. On ultrastructural examination, neurons in cerebral cortex showed to be inhibited in their differentiation by malathion; nuclear irregularity, swelling of endoplasmic reticulum, and cytoplasmic vacuoles were observed. On cytochemical study of acetylcholinesterase(AChE) by electron microscope, the positive reaction products of this enryme were localized at the membrane of nucleus and endoplasmic reticulum of neurons. Inhibition of AChE activty was severe in groups treated with relatively low doses, which was consistent with the results of spectrophotometric analysis. The activity of lactate dehydrogenase(LDH) of cerebrum in groups treated with malathion was higher than that of the control group. The nicotinamide adenine dinucleotide(NAD) content of chick embruo treated with malathioti decreased significantly, and nicotinamide coinjection raised the NAD level as compared with the control group, thus preventing malathion-induced momhological alteration. In conclusion, it is suggested that malathion changes the ultrastructure of differentiating neurons and alters some enzyme activities in chick embryo cerebrum, and the severity of which is consistently dose-or age-dependent.

• Applied Microscopy
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• v.29 no.4
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• pp.459-470
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• 1999

To investigate the changes during the differentiation of the cerebral neurons of the embryogenic day (ED) 9 and 10, investigated the ultrastructural changes in the cerebral neurons by Electromicroscope, also cerebral protein, the activity of dehydronases (LDH, MDH and SDH) and changes of adenosine triphosphate concentration were analyzed, the result obtained are as follows. In the ultrastructural changes in the cerebral neurons, chromatin in 9 day-old chick embryos are comparatively distributed to even in neucleoplasm and could investigate very prominently that nuclear membrane is double-layer. Esperially, Rough endoplasmic reticulum (RER) and Golgi complex are developed well, also polysome is investigated and synaptic vesicles were scattered. In 10 day-old chick embryos, chromatin evenly spread and nuclear membrane could be differentiated prominently. Rough endoplasmic reticulum (RER) contain cytoplasm, mitochondria and Golgi complex are comparatively developed well. In 9 day-old cultural group of chick embryo cerebrum were separated 37 polypeptide bands and In 10 day-old cultural group of chick embryo cerebrum were separated 38 poly -peptide bands. The more culture time increase, the more the activity of dehydronases (LDH, MDH and SDH) increase. LDH activity was 11.07 (9th day) and 12.12 (10th day), MDH activity was 11.89 (9th day) and 13.44 (10th day) and SDH activity was 8.45 (9th day) and 10.52 (10th day) respectively. The ATP concentration degreesed 10 day-old cultural group than 9 day-old cultural group.

• The Korean Journal of Zoology
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• v.34 no.3
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• pp.382-388
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• 1991

쥐의 교핵내에서 대뇌피질(또는 소뇌핵) 면면시 소뇌교핵계(또는 대뇌교핵계)의 연접구조의 변화에 대한 전자현미경적 관찰결과, 대뇌교핵계의 수입로 차단의 경우 소뇌교핵계의 신경섬유는 교핵세포의 원위 가지돌기쪽으로 발아하며, 소뇌핵 병변시 서뇌교핵계의 신경섬유는 근위가지돌기와 연접을 형성하거나 또는 여러개의 가지돌기 부속물들과 사구체형 연접복합체를 형성함이 밝혀졌다. 이상의 연구는 광학현미경적 관찰에서 언급된 대뇌피질(또는 소뇌핵) 병변에 따른 교핵내 신경종말의 밀도증가에 대한 보고를 뒷받침해주며, 소뇌핵 병변시 운동결핍증의 시간경과에 따른 회복에 대한 신경해부학적 근거를 제시한다.

• Korean Journal of Psychosomatic Medicine
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• v.9 no.1
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• pp.81-92
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• 2001

Stress has been linked to the pathophysiology and pathogenesis of various psychiatric illnesses. Over the past few years, our understanding of the brain and neuroendocrine systems that are linked to stress responses has increased enormously. This article reviews a series of animal and human studies to understand what are the central pathways by which stress is perceived, processed, and transduced into a neuroendocrine response. We focus on the limbic-hypothalamic-pituitary-adrenal(LHPA) axis and several neurotransmitter systems such as norepinephrine, CRF, serotonin, acetylcholine, and dopamine. LHPA stress circuit is a complex system with multiple control mechanisms which are altered in pathological states. CRF and related peptides in the central nervous system appear to enhance behavioral responses to stressors. Norepinephrine systems are also activated by stressors and cause the release of catecholamines from the autonomic nervous system. CRF-norepinephrine interaction makes a feed-forward system which may be important for an organism to mobilize not only the pituitary system but also the central nervous system, in response to environmental challenges. The interactions among several neurotransmitters and endocrine systems appear to play key roles in mediating various behavioral and psychological stress responses involving abnormal responses to stressors such as anxiety and affective disorders.

• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.333-338
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• 2000

In this paper, an automated segmentation algorithm is proposed for MR brain images using T1-weighted, T2-weighted, and PD images complementarily. The proposed segmentation algorithm is composed of 3 step. In the first step, cerebrum images are extracted by putting a cerebrum mask upon the three input images. In the second step, outstanding clusters that represent inner tissues of the cerebrum are chosen among 3-dimensional(3D) clusters. 3D clusters are determined by intersecting densely distributed parts of 2D histogram in the 3D space formed with three optimal scale images. Optimal scale image is made up of applying scale space filtering to each 2D histogram and searching graph structure. Optimal scale image best describes the shape of densely distributed parts of pixels in 2D histogram and searching graph structure. Optimal scale image best describes the shape of densely distributed parts of pixels in 2D histogram. In the final step, cerebrum images are segmented using FCM algorithm with its initial centroid value as the outstanding clusters centroid value. The proposed cluster's centroid accurately. And also can get better segmentation results from the proposed segmentation algorithm with multi spectral analysis than the method of single spectral analysis.

• The Korean Journal of Nuclear Medicine
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• v.32 no.5
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• pp.397-402
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• 1998

Purpose: The purpose of this study was to evaluate the phenomenon of diaschisis in the cerebellum and cerebral cortex in patients with pure basal ganglia hemorrhage using cerebral blood flow SPECT. Materials and Methods: Twelve patients with pure basal ganglia hemorrhage were studied with Tc-99m ECD brain SPECT. Asymmetric index (AI) was calculated in the cerebellum and cerebral cortical regions as |$C_R-C_L$/$(C_R-C_L){\times}200$, where $C_R$and $C_L$ are the mean reconstructed counts for the right and left ROIs, respectively. Hypoperfusion was considered to be present when AI was greater than mean +2 SD of 20 control subjects. Results: Mean AI of the cerebellum and cerebral cortical regions in patients with pure basal ganglia hemorrhage was significantly higher than normal controls (p<0.05): Cerebellum ($18.68{\pm}8.94$ vs $4.35{\pm}0.94$, $mean{\pm}SD$), thalamus ($31.91{\pm}10.61$ vs $2.57{\pm}1.45$), basal ganglia ($35.94{\pm}16.15$ vs $4.34{\pm}2.08$), parietal ($18.94{\pm}10.69$ vs $3.24{\pm}0.87$), frontal ($13.60{\pm}10.5$ vs $4.02{\pm}2.04$) and temporal cortex ($15.92{\pm}11.95$ vs $5.13{\pm}1.69$). Ten of the 12 patients had significant hypoperfusion in the contralateral cerebellum. Hypoperfusion was also shown in the ipsilateral thalamus (n=12), ipsilateral parietal (n=12), frontal (n=6) and temporal cortex (n=10). Conclusion: Crossed cerebellar diaschisis (CCD) and cortical diaschisis may frequently occur in patients with pure basal ganglia hemorrhage, suggesting that CCD can develop without the interruption of corticopontocerebellar pathway.

• Journal of the Korean Society of Radiology
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• v.81 no.6
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• pp.1412-1423
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• 2020

Purpose Some patients with neonatal seizures show diffuse, symmetric diffusion-restricted lesions in the cerebral white matter. The aim of this study was to describe clinical and imaging findings of patients with neonatal seizures who had diffuse, symmetric diffusion-restricted lesions without any structural or metabolic etiology. Materials and Methods A total of 56 neonates aged less than 1 week underwent brain magnetic resonance imaging (MRI) for evaluation of seizures from November 2008 to February 2017. After excluding 43 patients, 13 patients showed diffuse white matter abnormality on diffusion-weighted imaging. Initial and follow-up clinical and MRI findings were analyzed retrospectively. Results All 13 patients were born at full term. Among the ten patients who underwent a stool test for viruses, six were positive for rotavirus and one for astrovirus. MRI revealed diffuse, symmetric diffusion-restricted lesions distributed along the cerebral white matter, thalami, and midbrain variably. Conclusion Diffuse, symmetric diffusion-restricted lesions involving the cerebral white matter can be seen in patients with neonatal seizures without any structural or metabolic etiology. Rotavirus is commonly but not exclusively detected in these patients. Nevertheless, viral infection-associated encephalopathy should be considered for patients with characteristic clinical and MRI findings.