• Korean Journal of Medicinal Crop Science
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• v.14 no.2
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• pp.70-76
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• 2006

Paeoniae radix has been widely used for its anti-allergic, anti-inflammatory and analgesic effects, and demonstrated to have anticonvulsant, memory enhancing and anxiolytic activities. The present study was performed to examine the protective effect of methanol extract of Paeoniae radix (PR) from Paeoniae Japonica Miyabe et Takeda (Paeoniaceae) on hydrogen peroxide $(H_2O_2)-induced$ neurotoxicity using cultured rat cerebral cortical neuron. $H_2O_2$ produced a concentration-dependent reduction of neuronal viability, PR, over a concentration range of 10 to $100\;{\mu}g/ml$ showed concentration-dependent decrease of the $H_2O_2$$(100\;{\mu}M)-induced$ neuronal cell death, as assessed by a 3-[4,5-dimethylthiazol-2-yl]-2,5-di-phenyl-tetrazolium bromide assay and the number of apoptotic nuclei, evidenced by Hoechst 33342 staining. PR $(100\;{\mu}g/ml$ inhibited $100\;{\mu}M$ $H_2O_2-induced$ elevation of the cytosolic $Ca^{2+}$ concentration $([Ca^{2+}]_c)$, which was measured by a fluorescent dye, flue-4 AM. PR $(50\;{\mu}g/ml$ inhibited glutamate release into medium induced by $100\;{\mu}M$ $H_2O_2$, which was measured by HPLC, and generation of reactive oxygen species (ROS). These results suggest that PR may mitigate the $H_2O_2-induced$ neurotoxiciy by interfering with the increase of $[Ca^{2+}]_c$, and then inhibiting glutamate release and generation of ROS in cultured neurons.

• Molecules and Cells
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• v.22 no.1
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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.

• The Journal of Korean Physical Therapy
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• v.27 no.3
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• pp.135-139
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• 2015

Purpose: The aim of this study was to compare EEG topographical maps in patients with chronic stroke after action observation physical training. Methods: Ten subjects were recruited from a medical hospital. Participants observed the action of transferring a small block from one box to another for 6 sessions of 1 minute each, and then performed the observed action for 3 minutes, 6 times. An EEG-based brain mapping system with 32 scalp sites was used to determine cortical reorganization in the regions of interest (ROIs) during observation of movement. The EEG-based brain mapping was comparison in within-group before and after training. ROIs included the primary sensorimotor cortex, premotor cortex, superior parietal lobule, inferior parietal lobule, superior temporal lobe, and visual cortex. EEG data were analyzed with an average log ratio in order to control the variability of the absolute mu power. The mu power log ratio was in within-group comparison with paired t-tests. Results: Participants showed activation prior to the intervention in all of the cerebral cortex, whereas the inferior frontal gyrus, superior frontal gyrus, precentral gyrus, and inferior parietal cortex were selectively activated after the training. There were no differences in mu power between each session. Conclusion: These findings suggest that action observation physical training contributes to attaining brain reorganization and improving brain functionality, as part of rehabilitation and intervention programs.

• Natural Product Sciences
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• v.21 no.2
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• pp.134-140
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• 2015

The present study aims to investigate the effect of methanol extract of Korean mistletoe (KM; Viscum album var. coloratum), on amyloid $\beta$ protein ($A\beta$) (25-35), a synthetic 25-35 amyloid peptide, -induced neurotoxicity in cultured rat cerebral cortical neurons and memory impairment in mice. Exposure of cultured neurons to $10{\mu}M$ $A\beta$ (25-35) for 24 h induced a neuronal cell death, which was measured by a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and Hoechst 33342 staining. KM (10, 30 and $50{\mu}g/ml$) significantly inhibited the $A\beta$ (25-35)-induced apoptotic neuronal death. KM ($50{\mu}g/ml$) inhibited 10 μM Aβ (25-35)-induced elevation of intracellular calcium concentration ([Ca²⁺]_i), which was measured by a fluorescent dye, Fluo-4 AM. Glutamate release into medium and generation of reactive oxygen species (ROS) induced by $10{\mu}M$ $A\beta$ (25-35) were also inhibited by KM (10, 30 and $50{\mu}g/ml$). These results suggest that KM may mitigate the $A\beta$ (25-35)-induced neurotoxicity by interfering with the increase of [Ca²⁺]_i and then inhibiting glutamate release and generation of ROS in cultured neurons. In addition, orally administered KM (25 and 50 mg/kg, 7 days) significantly prevented memory impairment induced by intracerebroventricular injection of $A\beta$ (25-35) (8 nmol). Taken together, it is suggested that anti-dementia effect of KM is due to its neuroprotective effect against $A\beta$ (25-35)-induced neurotoxicity and that KM may have therapeutic role in prevention of the progression of Alzheimer's disease.

• The Journal of Korean Medicine
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• v.25 no.3
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• pp.32-44
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• 2004

Objectives : This study was undertaken to prove the effect of GSHT on the glutamate receptor, free radical and brain damage in rats subjected to brain ischemia Methods : Levels of cultured cortical neuron death caused by toxic chemicals were measured by LDH release assay. Neuroprotective effects of GSHT on brain tissues were examined in vivo by ischemic model of middle cerebral artery (MCA) occlusion. Results : GSHT showed significant inhibitory effect on LDH release induced by NMDA-kinate-Fe/sup 2+/. GSHT remarkably decreased coma duration time in a nonfatal dose of KCN and showed higher survival rate in a fatal dose. GSHT remarkably decreased ischemic area and edema induced by the MCA blood flow block. GSHT showed high improvement of forelimb and hind limb test after MCA occlusion in neurological examination. GSHT showed no significant change after MCA occlusion in pathological observation of the normal group. Conclusions : These results indicate that GSHT can be used to treat the brain damage caused by brain ischemia. Further study will be needed about the functional mechanism, etc.

• Journal of Korean Neurosurgical Society
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• v.61 no.3
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• pp.363-375
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• 2018

Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal age-adjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.