• The Korean Journal of Physiology and Pharmacology
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• 제21권5호
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• pp.475-485
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• 2017

The present study aimed to explore the neuroprotective effect and possible mechanisms of rhGLP-1 (7-36) against transient ischemia/reperfusion injuries induced by middle cerebral artery occlusion (MCAO) in type 2 diabetic rats. First, diabetic rats were established by a combination of a high-fat diet and low-dose streptozotocin (STZ) (30 mg/kg, intraperitoneally). Second, they were subjected to MCAO for 2 h, then treated with rhGLP-1 (7-36) (10, 20, $40{\mu}g/kg$ i.p.) at the same time of reperfusion. In the following 3 days, they were injected with rhGLP-1 (7-36) at the same dose and route for three times each day. After 72 h, hypoglycemic effects were assessed by blood glucose changes, and neuroprotective effects were evaluated by neurological deficits, infarct volume and histomorphology. Mechanisms were investigated by detecting the distribution and expression of the nuclear factor erythroid-derived factor 2 related factor 2 (Nrf2) in ischemic brain tissue, the levels of phospho-PI3 kinase (PI3K)/PI3K ratio and heme-oxygenase-1 (HO-l), as well as the activities of superoxide dismutase (SOD) and the contents of malondialdehyde (MDA). Our results showed that rhGLP-1 (7-36) significantly reduced blood glucose and infarction volume, alleviated neurological deficits, enhanced the density of surviving neurons and vascular proliferation. The nuclear positive cells ratio and expression of Nrf2, the levels of P-PI3K/PI3K ratio and HO-l increased, the activities of SOD increased and the contents of MDA decreased. The current results indicated the protective effect of rhGLP-1 (7-36) in diabetic rats following MCAO/R that may be concerned with reducing blood glucose, up-regulating expression of Nrf2/HO-1 and increasing the activities of SOD.

• Korean Journal of Radiology
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• 제19권6호
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• pp.1161-1171
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• 2018

Objective: The aim of this study was to investigate diffusion tensor (DT) imaging-derived properties of benign oligemia, true "at risk" penumbra (TP), and the infarct core (IC) during the first 3 hours of stroke onset. Materials and Methods: The study was approved by the local animal care and use committee. DT imaging data were obtained from 14 rats after permanent middle cerebral artery occlusion (pMCAO) using a 7T magnetic resonance scanner (Bruker) in room air. Relative cerebral blood flow and apparent diffusion coefficient (ADC) maps were generated to define oligemia, TP, IC, and normal tissue (NT) every 30 minutes up to 3 hours. Relative fractional anisotropy (rFA), pure anisotropy (rq), diffusion magnitude (rL), ADC (rADC), axial diffusivity (rAD), and radial diffusivity (rRD) values were derived by comparison with the contralateral normal brain. Results: The mean volume of oligemia was $24.7{\pm}14.1mm^3$, that of TP was $81.3{\pm}62.6mm^3$, and that of IC was $123.0{\pm}85.2mm^3$ at 30 minutes after pMCAO. rFA showed an initial paradoxical 10% increase in IC and TP, and declined afterward. The rq, rL, rADC, rAD, and rRD showed an initial discrepant decrease in IC (from -24% to -36%) as compared with TP (from -7% to -13%). Significant differences (p < 0.05) in metrics, except rFA, were found between tissue subtypes in the first 2.5 hours. The rq demonstrated the best overall performance in discriminating TP from IC (accuracy = 92.6%, area under curve = 0.93) and the optimal cutoff value was -33.90%. The metric values for oligemia and NT remained similar at all time points. Conclusion: Benign oligemia is small and remains microstructurally normal under pMCAO. TP and IC show a distinct evolution of DT-derived properties within the first 3 hours of stroke onset, and are thus potentially useful in predicting the fate of ischemic brain.

• The Korean Journal of Physiology and Pharmacology
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• 제12권5호
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• pp.275-280
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• 2008

A brief ischemic insult induces significant protection against subsequent massive ischemic events. The molecular mechanisms known as preconditioning (PC)-induced ischemic tolerance are not completely understood. We investigated whether kinetic changes of cyclooxygenase (COX)-2 during reperfusion time-periods after PC were related to ischemic tolerance. Rats were given PC by occlusion of middle cerebral artery (MCAO) for 10 min and sacrificed after the indicated time-periods of reperfusion (1, 2, 4, 8, 12, 18 or 24 h). In PC-treated rats, focal ischemia was induced by occlusion of MCA for 24 h and brain infarct volume was then studied to determine whether different reperfusion time influenced the damage. We report that the most significant protection against focal ischemia was obtained in rats with 8 h reperfusion after PC. Administration of indomethacin (10 mg/kg, oral) or rofecoxib (5 mg/kg, oral) 48 h prior to PC counteracted the effect of PC. Immunohistochemical analysis showed that COX-2 and HO-l protein were induced in PC-treated rat brain, which was significantly inhibited by rofecoxib. Taken together, we concluded that the kinetic changes of COX-2 expression during the reperfusion period after PC might be partly responsible for ischemic tolerance.

• Korean Journal of Acupuncture
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• 제22권3호
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• pp.137-156
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• 2005

Objectives : Cnidium officinale(CO) has been used for medication for stroke in the Oriental Medicine. So this study was planned to investigate the effects of CO on the focal ischemia-induced by Middle Cerebral Artery Occlusion(MCAO) in rats Materials and methods : The focal ischemia was induced by MCAO. CO extracts through oral administration and herbal acupuncture at GB2l was carried out during 3 weeks after focal ischemia-induced. Eight-arm radial maze was used for the behavioral task. For the neuroprotective effect of CO, we investigated AchE, ChAT, and NGF-expression by immnohistochemical method. Results : The error rate in the eight-arm radial maze task was significantly decreased in normal group compared to control group on 1-6days, OA-CO1(CO oral administration, 0.8g/kg) group on 1-6days, OA-CO2(CO oral administration, 1.6g/kg) group on 1-3,5,6days, HA-CO1(CO herbal acupuncture, 0.016g/kg) group on 2,3,6days, HA-CO2(CO herbal acupuncture, 0.008g/kg) group on 1-3,5,6days. The rate of correct choice was significantly increased in OA-CO1, HA-CO2. The density of neurons in the hippocampal CA1 was the most increased in OA-CO1, HA-CO1, HA-CO2. The density of ChAT in the hippocampal CA1 was increased in OA-CO1, HA-CO2. The density of ChAT in the hippocampal CA1 was significantly increased in OA-CO1, HA-CO2. The density of NGE in the hippocampal CAI was significantly increased in OA-CO1, OA-CO2, HA-CO2. Conclusions : These results suggest that CO oral administration with 0.8g/kg and CO herbal acupuncture with 0.008g/kg might be used as a regulator of cell death of cholinergic system induced by stroke.

• 한국콘텐츠학회논문지
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• 제9권2호
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• pp.309-317
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• 2009

본 연구는 뇌손상 흰쥐에서 기억과 학습훈련을 통해 인지기능회복과 해마의 신경 성장인자에 미치는 영향을 알아보고자 하였다. 뇌손상은 Sprague-Dawley계 흰쥐 36마리를 중대뇌동맥(middle cerebral artery)을 폐색하여 유발하였고, 실험 군들은 3개 군으로 분류하였다; 실험 군 I은 뇌손상유발 군(n=12), 실험 군 II는 뇌손상 유발 후 트레드밀훈련 군(n=12), 실험 군 Ⅲ은 뇌손상 유발 후 기억과 학습훈련 군(n=12)으로 나누었다. 인지기능 검사를 위해 수중모리스미로 습득검사와 파지검사를 실시하였으며, 조직학적 검사는 해마조직의 BDNF(brain-derived neurotrophic factor) 면역조직화학 반응을 관찰하였다. 수중모리스미로 습득 검사(Morris water maze acquisition test)는 시간과 군사이의 교호작용이 유의한 차이가 나타났고(p<.001), III군에서 9일에서 12일째까지 원형도피대를 찾는 시간이 I, II군에 비해 단축되었다. 수중모리스미로 파지검사(retention test)는 군 사이에서도 유의한 차이가 나타났으며(p<.001), 13일째 III군에서 원형도피대가 있었던 사분원에 배회하는 시간이 가장 길었다. 조직학적 검사는 III군에서 7일째 해마조직의 CA1에서 BDNF의 면역조직화학반응이 I, II군에 비해 면역양성반응의 증가를 관찰하였다. 뇌손상 흰쥐에서 기억과 학습훈련이 신경성장인자 발현 변화와 이로 인한 신경연접 가소성의 변화를 통해 인지기능회복에 더 좋은 영향을 주었다.

• Journal of Ginseng Research
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• 제47권2호
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• pp.199-209
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• 2023

Background: Due to the interrupted blood supply in cerebral ischemic stroke (CIS), ischemic and hypoxia results in neuronal depolarization, insufficient NAD+, excessive levels of ROS, mitochondrial damages, and energy metabolism disorders, which triggers the ischemic cascades. Currently, improvement of mitochondrial functions and energy metabolism is as a vital therapeutic target and clinical strategy. Hence, it is greatly crucial to look for neuroprotective natural agents with mitochondria protection actions and explore the mediated targets for treating CIS. In the previous study, notoginseng leaf triterpenes (PNGL) from Panax notoginseng stems and leaves was demonstrated to have neuroprotective effects against cerebral ischemia/reperfusion injury. However, the potential mechanisms have been not completely elaborate. Methods: The model of middle cerebral artery occlusion and reperfusion (MCAO/R) was adopted to verify the neuroprotective effects and potential pharmacology mechanisms of PNGL in vivo. Antioxidant markers were evaluated by kit detection. Mitochondrial function was evaluated by ATP content measurement, ATPase, NAD and NADH kits. And the transmission electron microscopy (TEM) and pathological staining (H&E and Nissl) were used to detect cerebral morphological changes and mitochondrial structural damages. Western blotting, ELISA and immunofluorescence assay were utilized to explore the mitochondrial protection effects and its related mechanisms in vivo. Results: In vivo, treatment with PNGL markedly reduced excessive oxidative stress, inhibited mitochondrial injury, alleviated energy metabolism dysfunction, decreased neuronal loss and apoptosis, and thus notedly raised neuronal survival under ischemia and hypoxia. Meanwhile, PNGL significantly increased the expression of nicotinamide phosphoribosyltransferase (NAMPT) in the ischemic regions, and regulated its related downstream SIRT1/2/3-MnSOD/PGC-1α pathways. Conclusion: The study finds that the mitochondrial protective effects of PNGL are associated with the NAMPT-SIRT1/2/3-MnSOD/PGC-1α signal pathways. PNGL, as a novel candidate drug, has great application prospects for preventing and treating ischemic stroke.

• 대한핵의학회지
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• 제29권3호
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• pp.294-306
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• 1995

국소뇌허혈에서 MK-801의 신경세포방어효과를 검토하기 위하여 흰쥐의 중뇌동맥을 폐색시켜 뇌허혈 및 경색을 유발하기 전과 후에 MK-801을 투여한 후 국소뇌포도당이용률의 변화를 2-deoxy-D-(14C)glu-cose 자가방사기록법을 이용하여 측정하고 이를 대조군과 비교하였다. 중대뇌동맥폐색 시술 전과 후에 평균동맥압, 직장체온, 동맥혈 PH, $pCO_2,\;pO_2$의 유의한 차이는 없었다. [$^{14}C$]DG 실험 중 대조군, MK-801 전처처군과 MK-801 후처치군 사이에서 평균동맥압, 직장 체온, 동맥혈장 당농도, 동맥혈 pH, $pCO_2,\;pO_2$의 유의한 차이는 없었다. 대조군에서 중대뇌동맥폐색 24시간 후에 폐색된 대뇌반구의 전두엽피질, 두정엽피질, 담창구, 편도, 해마 CA-2 지역, CA-3 지역, 내비회, 후두엽피질, 측두엽피질의 국소뇌포도당이용률은 반대쪽정상 대뇌반구 상동부위의 국소뇌포도당이용률보다 유의하게 낮았다. MK-801 전처치군에서 전두엽피질, 두정엽피질, 편도, 해마 CA-2 지역, 내비회, 후두엽피질, 측두엽피질의 병변/정상 국소뇌포도당이용률 비는 대조군의 그것보다 유의하게 높았다. 한편 MK-801 후처치군에서는 전두엽피질, 두정엽피질, 해마 CA-2 지역, 후두엽피질, 측두엽피질의 병변/정상 국소뇌포도 당이용률 비가 대조관의 그것보다 유의하게 높았다. MK-801 전처치군 정상 대뇌반구의 미상핵-피각, 전두엽피질, 두정엽피질, 대상회전, 담창구, 시상, 뇌량, 해마 CA-1, CA-2, CA-3 지역, 후두엽피질, 측두엽피질의 국소뇌포도당이용률은 대조군 정상 대뇌반구의 그것보다 유의하게 높았다. 반면 MK-801 후처치군 정상 대뇌반구의 국소뇌포도당이용률은 대조군 정상대뇌반구의 국소뇌포도당이용률과 유의한 차이가 없었다. 뿐만 아니라 폐색된 대뇌반구에서도 정상 대뇌반구와 매우 유사한 결과를 보였다. 즉, MK-801 전처치군에서는 미상핵-피각, 전두엽피질, 두정엽피질, 대상회전, 담창구, 시상, 뇌량, 해마 CA-1, CA-2, CA-3 지역, 내비회, 후두엽피질, 측두엽피질의 국소뇌포도당이용률이 대조군보다 유의하게 높은 반면, MK-801 후처치군에서는 대조군과 유의한 국소뇌포도당이용률의 차이를 나타내지 않았다. 이상의 결과로부터 국소뇌허혈에서 MK-801은 신경세포방어효과를 나타낼 것으로 생각된다. MK-801은 뇌포도당이용률을 국소적으로 증가시키며, 이는 NMDA 수용체 길항제 투여와 뇌기능 변화의 유관성을 시사하는 것이다.

• Journal of Korean Neurosurgical Society
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• 제48권5호
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• pp.391-398
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• 2010

Objective : This study was designed to validate the cell trafficking efficiency of the in vivo bioluminescence image (BLI) study in the setting of transplantation of the luciferase expressing bone marrow-derived mesenchymal stem cells (BMSC), which were delivered at each different time after transient middle cerebral artery occlusion (MCAO) in a mouse model. Methods : Transplanting donor BMSC were prepared by primary cell culture from transgenic mouse expressing luciferase (LUC). Transient focal infarcts were induced in 4-6-week-old male nude mice. The experiment mice were divided into five groups by the time of MSC transplantation : 1) sham-operation group, 2) 2-h group, 3) 1-day group, 4) 3-day group, and 5) 1-week group. BLI for detection of spatial distribution of transplanted MSC was performed by detecting emitted photons. Migration of the transplanted cells to the infarcted area was confirmed by histological examinations. Differences between groups were evaluated by paired t-test. Results : A focal spot of bioluminescence was observed at the injection site on the next day after transplantation by Signal intensity of bioluminescence. After 4 weeks, the mean signal intensities of 2-h, 1-day, 3-day, and 1-week group were $2.6{\times}10^7{\pm}7.4{\times}10^6$. $6.1{\times}10^6{\pm}1.2{\times}10^6$, $1.7{\times}10^6{\pm}4.4{\times}10^5$, and $8.9{\times}10^6{\pm}9.5{\times}10^5$, respectively. The 2-h group showed significantly higher signal intensity (p<0.01). The engrafted BMSC showed around the infarct border zones on immunohistochemical examination. The counts of LUC-positive cells revealed the highest number in the 2-h group, in agreement with the results of BLI experiments (p<0.01). Conclusion : In this study, the results suggested that the transplanted BMSC migrated to the infarct border zone in BLI study and the higher signal intensity of LUC-positive cells seen in 2 hrs after MSC transplantation in MCAO mouse model. In addition, noninvasive imaging in real time is an ideal method for tracking stem cell transplantation. This method can be widely applied to various research fields of cell transplantation therapy.

• Journal of Korean Neurosurgical Society
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• 제58권3호
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• pp.167-174
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• 2015

Objective : This study investigates the role of a burr hole and calvarial bone marrow-derived stem cells (BMSCs) in a transient ischemic brain injury model in the rat and postulates a possible mechanism for the efficacy of multiple cranial burr hole (MCBH) surgery in moyamoya disease (MMD). Methods : Twenty Sprague-Dawley rats (250 g, male) were divided into four groups : normal control group (n=5), burr hole group (n=5), ischemia group (n=5), and ischemia+burr hole group (n=5). Focal ischemia was induced by the transient middle cerebral artery occlusion (MCAO). At one week after the ischemic injury, a 2 mm-sized cranial burr hole with small cortical incision was made on the ipsilateral (left) parietal area. Bromodeoxyuridine (BrdU, 50 mg/kg) was injected intraperitoneally, 2 times a day for 6 days after the burr hole trephination. At one week after the burr hole trephination, brains were harvested. Immunohistochemical stainings for BrdU, CD34, VEGF, and Doublecortin and Nestin were done. Results : In the ischemia+burr hole group, BrdU (+), CD34 (+), and Doublecortin (+) cells were found in the cortical incision site below the burr hole. A number of cells with Nestin (+) or VEGF (+) were found in the cerebral parenchyma around the cortical incision site. In the other groups, BrdU (+), CD34 (+), Doublecortin (+), and Nestin (+) cells were not detected in the corresponding area. These findings suggest that BrdU (+) and CD34 (+) cells are bone marrow-derived stem cells, which may be derived from the calvarial bone marrow through the burr hole. The existence of CD34 (+) and VEGF (+) cells indicates increased angiogenesis, while the existence of Doublecortin (+), Nestin (+) cells indicates increased neurogenesis. Conclusion : Based on these findings, the BMSCs through burr holes seem to play an important role for the therapeutic effect of the MCBH surgery in MMD.