• IMMUNE NETWORK
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• 제4권2호
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• pp.81-87
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• 2004

Background: In the thymus, developing thymocytes continually interact with thymic epithelial cell components. Self MHC restriction of mature T cells are imposed in the thymus through interaction of immature double positive thymocytes and thymic cortical epithelial cells. The site of negative selection, however, is a matter of debate. Through systemic injection of anti-TCR antibody or antigenic peptides, investigators suggested that most of the negative selection occurs in the thymic cortex. But the requirements for negative selection, i.e cellular counterparts and costimulatory molecules are more available in the medulla or cortico-medullary junction rather than in the thymic cortex. Methods: The direct and indirect pathways of thymocyte death after systemic anti-TCR antibody injection were separated through several experimental systems. B6 mice were either adrenalectomized or sham-adrenalectomized to evaluate the role of endogenous glucocorticoids from adrenal gland. Role of TNF were evaluated through using TNF receptor double knockout mice. Results: We found that without indirectly acting mediators such as $TNF-\alpha$ or corticosteroid, double positive thymocyte death were minimal by systemic injection of anti-TCR antibody in TNF receptor double knockout neonatal mice. Also by analyzing neonatal wild-type mice with adoptively transferred mature T cells, only peripheral activation of mature T cells could induce extensive double positive thymocyte death. Conclusion: Thus, systemically injected anti-TCR antibody mediated thymocyte death are mostly induced through indirect pathway.

• 동의신경정신과학회지
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• 제29권3호
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• pp.121-134
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• 2018

Objectives: The purpose of this in vivo study is to observe anti-amnesic effects of Yeongkyekamjotanggayonggolmoryo (YGYM), a novel mixed herbal prescription, Ossis Mastodi and Ostreae Testa added Yeongkyekamjo-tang, on scopolamine induced amnesia in C57BL/6 mice through acetylcholine (ACh) and acetylcholinesterase (AChE) activity, Choline acetyltransferase (ChAT) mRNA expression, and antioxidant effects. Methods: Six groups, total 20 intact or 100 Sco treated mice were used in this study after one week of acclimatization period. Half the animals were used for passive avoidance task tests and hippocampus ACh content, AChE activity, and ChAT mRNA expression were measured. The other half was subjected to an underwater maze test and then the cerebral cortex antioxidant defense system was measured. Results: In the passive avoidance experiment, there was significant decrease in residence time in the bright room and in the underwater maze test, escape latency to escape from the esophagus significantly increased compared with the normal control group. At the final sacrifice, ACh content and ChAT mRNA expression decreased, AChE activity increased, and cerebral cortical MDA increased GSH content, SOD and CAT activity in Sco control mice, as compared to intact vehicle control mice. However, these Sco treatment-related memory loss through AChE activation destroyed the cerebral cortex antioxidant defense system, and was inhibited dose-dependently by 28 days consecutive oral pretreatments of YGYM extracts 500, 250, 125 mg/kg. Conclusions: In the above results, YGYM extract that oral administration of YGYM extracts alleviates the antioxidant defense system, through preservation of ACh mediated by upregulation of ChAT mRNA expression, and increase of AChE inhibition and brain antioxidant defense systems.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.352-355
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• 2002

The purpose of this study was to investigate whether or not acupuncture of GB34 produces a significant response of the modulation of somatomotor areas by functional magnetic resonance imaging (fMRI) study. The acupoint, GB34, located in the back of the knee, is known to be effective in recovering motor function after stroke. Using 3T MRI scanner, functional MR imaging of the whole brain was performed in 12 normal healthy subjects during two stimulation paradigms; acupuncture manipulation on GB 34 and sham points. This study investigates the activation of the mortor cortex elicited by a soft and an intensified stimulation of GB 34. Three different paradigms were carried out to detect any possible modulation of the Blood Oxygenation Level Dependent (BOLD) response in the somatomortor area to motor stimulation through acupuncture. Group analysis from seven individuals showed that bilateral sensorimotor areas (BA 3,4,6 and 7) showed stimulation related BOLD signal contrast of approximately 6% whereas very few areas were activated when sham stimulation is given. The present study shows that acupuncture fMRI study can be safely conducted in 3T MRI environment, and acupuncture stimulation in GB34 modulates the cortical activities of the somatomotor area in human. The present findings may shed light on the CNS mechanism of motor function by acupuncture and form a basis for future investigations of motor modulation circuits in the stroke patients.

• 재활치료과학
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• 제5권2호
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• pp.11-22
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• 2016

목적: 본 연구는 국외 뇌졸중 환자에게 적용한 한 말초감각신경자극의 효과에 대하여 고찰하기 위한 것으로 국외 학술지를 대상으로 체계적 문헌고찰 연구방법을 시행하였다. 연구방법: 2015년 10월 이전까지 국외 학술지에 게재된 논문을 Pubmed를 통하여 검색하였다. 주요 검색 용어로는 'peripheral nerve stimulation', 'electrical stimulation', 'sensory stimulation', 'somatosensory stimulation', 'stroke', 'hemiplegia', 'hemiparesis' 와 'hand', 'arm', 'upper limb'를 사용하였다. 최초 검색된 논문은 501편이었으나 선정 및 배제기준을 거쳐 10편의 연구가 선정되었다. 결과: 임상적으로 널리 사용되고 있는 말초감각신경자극은 뇌졸중 환자들에게 적용이 될 때에 보다 다양한 중재방법으로 연구에 적용이 되고 있었다. 말초감각신경자극치료는 뇌졸중 환자의 상지 기능에 효과를 나타냈으며, 대뇌피질의 활성화에도 긍정적인 영향을 나타냈다. 결론: 본 연구는 말초감각신경자극치료의 적용에 대한 근거를 제시하며, 향후 국내연구에서는 다양한 중재방법을 적용하여 말초감각신경자극의 효과를 더 정확하게 측정을 할 수 있는 방법에 대한 연구가 필요하다.

• Clinical and Experimental Pediatrics
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• 제60권6호
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• pp.181-188
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• 2017

Purpose: Hypoxic-ischemic encephalopathy is a significant cause of neonatal morbidity and mortality. Erythropoietin (EPO) is emerging as a therapeutic candidate for neuroprotection. Therefore, this study was designed to determine the neuroprotective role of recombinant human EPO (rHuEPO) and the possible mechanisms by which mitogen-activated protein kinase (MAPK) signaling pathway including extracellular signal-regulated kinase (ERK1/2), JNK, and p38 MAPK is modulated in cultured cortical neuronal cells and astrocytes. Methods: Primary neuronal cells and astrocytes were prepared from cortices of ICR mouse embryos and divided into the normoxic, hypoxia (H), and hypoxia-pretreated with EPO (H+EPO) groups. The phosphorylation of MAPK pathway was quantified using western blot, and the apoptosis was assessed by caspase-3 measurement and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Results: All MAPK pathway signals were activated by hypoxia in the neuronal cells and astrocytes (P<0.05). In the neuronal cells, phosphorylation of ERK-1/-2 and apoptosis were significantly decreased in the H+EPO group at 15 hours after hypoxia (P<0.05). In the astrocytes, phosphorylation of ERK-1/-2, p38 MAPK, and apoptosis was reduced in the H+EPO group at 15 hours after hypoxia (P<0.05). Conclusion: Pretreatment with rHuEPO exerts neuroprotective effects against hypoxic injury reducing apoptosis by caspase-dependent mechanisms. Pathologic, persistent ERK activation after hypoxic injury may be attenuateed by pretreatment with EPO supporting that EPO may regulate apoptosis by affecting ERK pathways.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1998년도 추계학술발표 논문집
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• pp.225-229
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• 1998

The purpose of the current study was comparative analysis of autonomic and electrocortical responses to passive and active touch of the tektites with different subjective emotional preference. Perspective goal of the project is development of a template for classification of tactile stimuli according to subjective comfort and associated physiological manifestations. The study was carried out on 36 female college students. Physiological signals were acquired by Grass and B10PAC 100 systems with AcqKnowledge III software. Frontal, parietal and occipital EEG (relative power spectrum /percents/ of EEG bands - delta, theta, slow and fast alpha, low and fast beta), and autonomic variables, namely heart rate (HR), respiratory sinus arrhythmia (RSA), pulse transit time (PTT), respiration rate (RSP) and skin conductance parameters (SCL, amplitude, rise time and number of SCRs) were analyzed for rest baseline and stimulation conditions. Analysis of the overall pattern of reaction indicated that autonomic response to tactile stimulation was manifested in a form of moderate HR acceleration, RSP increase, RSA decrease (lowered vagal tone), decreased n and increased electrodermal activity (increased SCL, several SCRs) that reflects general sympathetic activation. Parietal EEG effects (on contra-lateral side to stimulated hand) were featured by short-term alpha-blocking, slightly reduced theta and significantly increased delta and enhanced fast beta activity with few variations across stimuli. The main finding of the study was that most and least preferred textures exhibited significant differences in autonomic (HR, RSP, PTT, SCR, and at less extent in RSA and SCL) and electrocortical responses (delta, slow and fast alpha, fast beta relative power). These differences were recorded both in passive and active stimulation modes, thus demonstrating reproducibility of distinction between most and least emotionally preferred tactile stimuli, suggesting influence of psychological factors, such as emotional property of stimulus, on physiological outcome. Nevertheless, development of sufficiently sensitive .and reliable template for classification of emotional responses to tactile stimulation based on physiological response pattern may require more extensive empirical database.

• Childhood Kidney Diseases
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• 제11권2호
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• pp.152-160
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• 2007

목 적 : 이식신 생검은 이식신 기능 이상의 원인, 거부반응의 정도, 예후 등을 확인하는데 도움이 된다. 그러나 이식신의 조직학적 변화가 신피질에 고르게 분포하지 않는 경우를 흔히 보게 된다. 따라서 본 연구는 이러한 이식신 생검에서의 잠재적인 표본추출의 오류를 평가하기 위하여 시행되었다. 방법 : 569개의 이식신 생검 표본 중에서 Banff criteria에 준하는 급성 거부반응을 보이고 있으며, 신피막부터 수질까지의 전 층을 포함하고 있는 신생검 표본 26개를 조사하였다. Banff criteria를 변형하여 조직의 변화를 간질성 염증(0-3+), 부종(0-3+), 요세관간질염(0-3+)으로 구분하여 급성거부반응의 등급을 표면 피질, 깊은 피질과 피질에 근접한 수질층 각각을 비교하여 조직학적 분석을 시행하였다. 결과 : 간질성 염증(P=0.019), 부종(P=0.023), 요세관 거부등급(P=0.019)에서 깊은 피질에서 표면 피질에 비해 급성 거부반응의 정도가 심하였다. 결론 : 이식신의 급성 거부반응을 진단하기 위하여 신생검을 실시 할 경우 깊은 피질이 포함되지 않으면 급성 거부반응을 과소 평가 할 수 있으므로 주의해야 할 것으로 사료된다.

• 감성과학
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• 제1권2호
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• pp.13-22
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• 1998

The sense of touch has both objective and subjective characteristics. During hand evaluation of the fabrics. psycho physiological processes such as emotion and stimulation. On other site, the mode of touch (passive vs. active) is also capable to modulate somatosensory responses. I.e., suppress somatocensory perception during active electrocortical responses to passive and active touch of the textiles with different subjective emotional preference. The study was carried out on 36 female college students. Physiological signals were acquired by Grass and BIOPAC 100 systems with AcqKnowledge variables, namely heart rate (HR), respiratory sinus arrhythmia (RSA), pulse transit time (PTT), respiration rate (RSP) and skin conductance parameters (SCL, amplitude, risetime and number of SCRs) were analyzed for baseline and stimulation conditions. Analysis was manifested in a form of moderate HR acceleration. RSP increase, RSA decrease (lowered vagal tone), decreased PTT and increased electrodermal activity (increased SCL, several SCRs) that reflects general sympathetic activation. Parietal EEG effects (on contra-lateral side to stimulated hand)were featured by short-term alpha-blocking, slightly reduced theta, significantly increased delta and enhanced fast beta activity with few variations across stimuli. The main finding of the study was that most and least preferred textures exhibited significant differences in autonomic (HR, RSP, PTT, SCR, and at less extent in RSA and SCL) and electrocortical responses (delta, slow and fast alpha, fast beta relative power). These differences were recorded both in passive and active stimulation modes, thus demonstrating reproducibility of distinction between most and least emotionally preferred tactile stimuli, suggesting influence of psychological factors, such as emotional property of stimulus, on physiological outcome.

• Molecules and Cells
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• 제22권1호
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• pp.8-12
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• 2006

Neuron-derived orphan receptor (NOR-1) is a member of the thyroid/steroid receptor superfamily that was originally identified in forebrain neuronal cells undergoing apoptosis. In addition to apoptotic stimuli, activation of several signal transduction pathways including direct neuronal depolarization regulates the expression of NOR-1. In this study we tested whether the expression of NOR-1 is changed following transient ischemic injury in the adult rat brain. NOR-1 mRNA increased rapidly in the dentate gyrus of the hippocampal formation and piriform cortex 3 h after transient global ischemia and returned to basal level at 6 h. On the other hand, oxygen-glucose deprivation of cultured cerebral cortical neurons did not alter the expression of NOR-1. These results suggest that expression of NOR-1 is differentially regulated in different brain regions in response to globally applied brain ischemia, but that hypoxia is not sufficient to induce its expression.

• Corrosion Science and Technology
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• 제7권3호
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• pp.162-167
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• 2008

Degradable implants have been in use for bone surgery for decades. However, degradable metal implants are one of the new research areas of biomaterials science. Magnesium has good biocompatibility due to its low toxicity, and it is a corroding, i.e. dissolvable, metal. Furthermore, magnesium is needed in human body, and naturally found in bone tissue. There have been some published reports also asserting the potential bone cell activation or bone healing effect of high magnesium ion concentrations. The classic method for achieving intertransverse process fusion involves autogenous iliac crest bone graft. Several investigations have been performed to enhance this type of autograft fusion. However, there is no research which has been undertaken to investigate the efficiency of pure magnesium particles in posterolateral spinal fusion. In this study, corrosion behavior of magnesium metal at the bone interface, the possibility of new bone cell formation and the degree of effectiveness in producing intertransverse process lumbar fusion in a sheep model have been investigated. Cortical bone screws were machined from magnesium alloy AZ31 extruded rod and implanted to hip-bones of sheep via surgery. Three months after surgery, the bone segments carrying these screws were removed from the sacrificed animals. Samples were sectioned to reveal Mg/bone interfaces and investigated using optical microscope, SEM-EDS and radiography. Optical and SEM images showed that there was a significant amount of corrosion on the magnesium screw. The elemental mapping results indicate, due to the presence of calcium and phosphorus elements, that there exists new bone formation at the interface. Furthermore, sixteen sheep were subjected to intertransverse process spinal fusions with pedicle screw fixation at various locations along their spines. Each animal was treated with 5cc autograft bone at one fusion level and 1cc magnesium+5cc autograft bone at the other. Six months after surgery, bone formation was evaluated by gross inspection and palpation, and radiological, histological, scanning electron microscopic and x-ray diffraction analyses. It may be stated that the potential for using useful corrosion of magnesium alloys in medical applications is expected to be significant.