26 results on '"BYUNG TAE CHOI"'
Search Results
2. Glycoconjugates of the gastric mucosa in cold-treated chipmunks.
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Byung-Tae Choi, Un-Bock Jo, and Young-Gi Gil
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CHIPMUNKS , *GASTRIC mucosa , *HIBERNATION , *EPITHELIUM - Abstract
During seasonal hibernation, there is reduced gastrointestinal activity, but relatively little is known of the physiology involved. In the present experimental study, male Korean chipmunks (Tamias sibiricus barberi) were maintained in cold conditions (6 °C) for 3, 5 or 9 months to mimic conditions occurring during seasonal hibernation. Changes in the composition of glycoconjugates (Gcs) of the gastric mucosa were determined after cold-treatment. Cold-treated chipmunks, in comparison with warm control animals, revealed a thinner layer of Gcs on the free surface gastric epithelium with reduced depth of their pits. Cold-treated chipmunks showed similar staining patterns and lectin affinity for Gcs as compared with warm control animals. After long-term cold treatment, reduction in the amounts of Gcs were more severe in gastric pit epithelium and glandular mucous cells than in the free surface gastric epithelium. A significant reduction in immunostaining of nitric oxide synthase (NOS) was also observed in chipmunks after long-term cold-treatment. The changes in Gcs and NOS staining patterns may be interpreted in relation with a continued but reduced functioning of the gastric mucosa throughout hibernation. However, the findings in the present experimental model for hibernation, which shows significant changes in Gcs and NOS staining patterns, need to be demonstrated during seasonal hibernation in the wild. [ABSTRACT FROM AUTHOR]
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- 2003
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3. NEW FRAME RATE UP-CONVERSION USING BI-DIRECTIONAL MOTION ESTIMATION.
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Byung-Tae Choi and Sung-Hee Lee
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FRAME relay (Data transmission) , *MAGNETIC recorders & recording , *DIGITAL electronics - Abstract
Provides information on a study which proposed a frame rate up-conversion algorithm for high quality video. Background on frame rate up-conversion; Problems with existing motion-compensated frame rate up-conversion algorithm; Presentation of experimental results; Conclusion.
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- 2000
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4. AN EFFECTIVE DE-INTERLACING TECHNIQUE USING MOTION COMPENSATED INTERPOLATION.
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You-Young Jung and Byung-Tae Choi
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INTERPOLATION , *EQUATIONS of motion , *FILTERS (Mathematics) - Abstract
Deals with a study which proposed a de-interlacing algorithm using motion compensated interpolation. Discussion of an adaptive interpolation technique using median filtering; Presentation of results; Conclusions.
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- 2000
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5. A single fraction from Uncaria sinensis exerts neuroprotective effects against glutamate-induced neurotoxicity in primary cultured cortical neurons.
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Ha Neui Kim, Ji Yeon Jang, and Byung Tae Choi
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UNCARIA , *PLANT extracts , *NEURONS , *CELL survival , *LACTATE dehydrogenase , *CELL death , *CELLULAR signal transduction , *METHYL aspartate receptors - Abstract
We identified a neuroprotective single fraction among 62 ones of hexane extract from Uncaria sinensis (JGH43IA) and investigated its effects and mechanisms in primary cortical neurons. Pretreatment with JGH43IA showed a significantly increase cell viability in a dose-dependent manner with a decrease in the lactate dehydrogenase release. When we performed morphological assay and flow cytometry to determination of the type of cell death, pretreatment with JGH43IA showed a significant reduction of glutamate-induced apoptotic cell death. Then we explored the downstream signaling pathways of N-methyl-D-aspartate receptor (NMDAR) with calpain activation to elucidate possible pathways of neuroprotection by JGH43IA. Pretreatment with JGH43IA exhibited a significant attenuation of NMDAR GluN2B subunit activation and a decrease in active form of calpain 1 leading to subsequent cleavage of striatal-enriched protein tyrosine phosphatase (STEP). In addition, pretreatment with JGH43IA showed a marked increase of cAMP responsive element binding protein. These results suggest that JGH43IA may have neuroprotective effects through down-regulation of NMDAR GluN2B subunit and calpain 1 activation, and subsequent alleviation of STEP cleavage. This single fraction from U. sinensis might be a useful therapeutic agent for brain disorder associated with glutamate injury. [ABSTRACT FROM AUTHOR]
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- 2015
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6. N-Methyl-D-Aspartate Antagonist Inhibits NR-1 Subunit Phosphorylation of the Spinal N-Methyl-D-Aspartate Receptor Induced by Low Frequency Electroacupuncture.
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Byeol-Rim Kang, Chang-Beohm Ahn, and Byung-Tae Choi
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ELECTROACUPUNCTURE , *ANALGESIA , *METHYL aspartate , *PHOSPHORYLATION , *SPINAL cord - Abstract
We investigated whether the 2 Hz electroacupuncture (EA) analgesia is associated with phosphorylation of N-methyl-D-aspartate receptor (NMDAR) NR-1 subunits and NMDAR antagonism in the lumbar spinal cord of rats. EA stimulation produced an increase of serine phosphorylation of NMDAR NR-1 subunits in the spinal cord as compared with normal conditions. However, the intrathecal injection of NMDAR antagonist D-2-amino-5-phosphonopentanoic acid significantly prevented serine phosphorylation of NMDAR NR-1 subunits induced by EA stimulation in the dorsal horn of spinal cord. These results indicate that EA analgesia by stimulation of peripheral nerves may be involved in an increase of NR-1 serine phosphorylation in the dorsal horn of the spinal cord. [ABSTRACT FROM AUTHOR]
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- 2007
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7. Effects of Electroacupuncture with Different Frequencies on the Glycoconjugate Alterations in Articular Cartilage in the Ankle Joints of Complete Freund's Adjuvant-injected Rats.
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In-Bum Park, Chang-Beohm Ahn, and Byung-Tae Choi
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ELECTROACUPUNCTURE , *ARTHRITIS , *GLYCOCONJUGATES , *EDEMA , *LECTINS - Abstract
The aim of this study was to investigate the effects of electroacupuncture (EA) on the glycoconjugate (GC) changes in articular cartilage in the ankle of an arthritic model. Arthritis was induced by an intraplantar injection of complete Freund's adjuvant (CFA) into the hindpaw of male Sprague-Dawley rats. Bilateral EA stimulation at 2 Hz, 15 Hz and 120 Hz was applied at those acupoints corresponding to Zusanli and Sanyinjiao in man, using needles for 3-day intervals for 30 days. To determine the presence of arthritis, paw edema was measured by a water displacement plethysmometer. Edema of the hindpaw induced by CFA-injection was strongly inhibited by EA stimulation throughout the experimental period. At 30 days after CFA-injection, GC changes of articular cartilage of the ankle joint were observed using conventional and lectin histochemistry. The CFA-injected rat revealed general reduction of staining abilities and lectin affinities for GC in comparison with normal rats. Significant reductions of neutral and acidic GC were observed in interterritorial matrix and chondrocyte capsules, respectively. All lectin affinities examined except DBA were also decreased in CFA-injected rats compared to normal ones. However, EA-treated rats, showed similar staining patterns and lectin affinities for GC as to normal ones, especially neutral GC in interterritorial matrix and sWGA and RCA-1 affinities in chondrocytes. It is concluded that EA in all frequencies examined, especially 2 Hz, can attenuate inflammatory edema in CFA-injected rats through alleviation of alterations of GC components in articular cartilage. [ABSTRACT FROM AUTHOR]
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- 2006
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8. Histological and functional assessment of the efficacy of constraint-induced movement therapy in rats following neonatal hypoxic-ischemic brain injury.
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HYUNHA KIM, MIN JAE KIM, YOUNG SOO KOO, HAE IN LEE, SAE-WON LEE, MYUNG JUN SHIN, SOO-YEON KIM, YONG BEOM SHIN, YONG-IL SHIN, BYUNG TAE CHOI, YOUNG JU YUN, and HWA KYOUNG SHIN
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HEMIPLEGICS , *PEOPLE with paralysis , *MOVEMENT therapy , *ANIMAL models in research , *ARTERIAL occlusions - Abstract
Constraint-induced movement therapy (CIMT) is used in stroke rehabilitation to promote recovery of upper limb motor function. However, its efficacy in improving functional outcomes in children with hemiplegic cerebral palsy has not been clearly determined in clinical or experimental research. The aim of our study was to assess the efficacy of a new experimental model of CIMT, evaluated in terms of mortality, stress, motor and cognitive function in rats having undergone a neonatal hypoxic-ischemic (HI) brain injury. Neonatal HI injury was induced at post-natal day 7 through unilateral ligation of the common carotid artery followed by exposure to hypoxia for 2 h. CIMT was implemented at 3 weeks, post-HI injury, using a pouch to constrain the unimpaired forelimb and forcing use of the affected forelimb using a motorized treadmill. After HI injury, animals demonstrated motor and cognitive deficits, as well as volumetric decreases in the ipsilateral hemisphere to arterial occlusion. CIMT yielded a modest recovery of motor and cognitive function, with no effect in reducing the size of the HIlesion or post-HI volumetric decreases in brain tissue. Therefore, although animal models of stroke have identified benefits of CIMT, CIMT was not sufficient to enhance brain tissue development and functional outcomes in an animal model of hemiplegic cerebral palsy. Based on our outcomes, we suggest that CIMT can be used as an adjunct treatment to further enhance the efficacy of a program of rehabilitation in children with hemiplegic cerebral palsy. [ABSTRACT FROM AUTHOR]
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- 2017
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9. Beneficial effects of Jiawei Shenqi-wan and treadmill training on deficits associated with neonatal hypoxic-ischemia in rats.
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HA NEUI KIM, MALK EUN PAK, MYUNG JUN SHIN, SOO YEON KIM, YONG BEOM SHIN, YOUNG JU YUN, HWA KYOUNG SHIN, and BYUNG TAE CHOI
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ISCHEMIC preconditioning , *BODY-weight-supported treadmill training , *ISCHEMIA , *HERBAL medicine , *CEREBRAL palsy - Abstract
Jiawei Shenqi-wan (JSQW), which comprises Shenqi-wan and two additional medicinal herbs, has been widely used for the treatment of various growth impairments, including cerebral palsy. In the present study, JSQW was administered to hypoxic-ischemic Sprague-Dawley rats that underwent treadmill training from 4-7 weeks of age to examine the beneficial effects of combined JSQW and treadmill therapy. Behavioral examinations were performed and a significant improvement in cylinder test performance was observed in rats treated with treadmill training compared with hypoxic-ischemia rats (P<0.05), as well as a significant improvement in passive avoidance test performance for rats treated with JSQW (P<0.05). The thickness of the corpus callosum and the integrated optical density (IOD) of myelin basic protein (MBP) were significantly increased by treatment with treadmill therapy alone (P<0.01 and P<0.001, respectively) and treatment with both JSQW and treadmill significantly increased the IOD of MBP compared with hypoxic-ischemia rats (P<0.001). Western blot analysis revealed that the expression of neuronal nuclei (NeuN) and doublecortin (Dcx) significantly decreased (P<0.001 and P<0.05, respectively) and MBP expression markedly decreased in the ipsilateral subventricular zone of hypoxic-ischemic rats compared with the control group; however, the expression of NeuN was significantly recovered by treatment with both JSQW and treadmill training (P<0.05). Furthermore, Dcx expression was significantly recovered by treatment with JSQW (P<0.05), and MBP expression was significantly restored by treatment with treadmill training (P<0.01). In the immunohistochemical analyses, a significant increase in the number of bromodeoxyuridine (BrdU) positive cells in this region was observed in treadmill-treated rats (P<0.05), whereas significant increases in the number of Brdu/Dcx or NeuN or glial fibrillary acidic protein double-positive cells were observed only in the group co-treated with JSQW and treadmill (P<0.01, P<0.05 and P<0.001, respectively). These results suggest that JSQW and treadmill training may contribute to behavior recovery following hypoxic-ischemia, and JSQW treatment was particularly effective in promoting memory function via enhancing the differentiation of neuronal progenitor cells. The results of the present study therefore suggest that JSQW may provide an additional treatment option for functional recovery with treadmill training in cerebral palsy. [ABSTRACT FROM AUTHOR]
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- 2017
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10. Antidepressant Effects of Aripiprazole Augmentation for Cilostazol-Treated Mice Exposed to Chronic Mild Stress after Ischemic Stroke.
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Yu Ri Kim, Ha Neui Kim, Ki Whan Hong, Hwa Kyoung Shin, and Byung Tae Choi
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ANTIDEPRESSANTS , *ARIPIPRAZOLE , *PSYCHOLOGICAL stress , *STROKE , *ANHEDONIA - Abstract
The aim of this study was to determine the effects and underlying mechanism of aripiprazole (APZ) augmentation for cilostazol (CLS)-treated post-ischemic stroke mice that were exposed to chronic mild stress (CMS). Compared to treatment with either APZ or CLS alone, the combined treatment resulted in a greater reduction in depressive behaviors, including anhedonia, despair-like behaviors, and memory impairments. This treatment also significantly reduced atrophic changes in the striatum, cortex, and midbrain of CMS-treated ischemic mice, and inhibited neuronal cell apoptosis, particularly in the striatum and the dentate gyrus of the hippocampus. Greater proliferation of neuronal progenitor cells was also observed in the ipsilateral striatum of the mice receiving combined treatment compared to mice receiving either drug alone. Phosphorylation of the cyclic adenosine monophosphate response element binding protein (CREB) was increased in the striatum, hippocampus, and midbrain of mice receiving combined treatment compared to treatment with either drug alone, particularly in the neurons of the striatum and hippocampus, and dopaminergic neurons of the midbrain. Our results suggest that APZ may augment the antidepressant effects of CLS via co-regulation of the CREB signaling pathway, resulting in the synergistic enhancement of their neuroprotective effects. [ABSTRACT FROM AUTHOR]
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- 2017
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11. Electroacupuncture preconditioning reduces ROS generation with NOX4 down-regulation and ameliorates blood-brain barrier disruption after ischemic stroke.
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Yeon Suk Jung, Sae-Won Lee, Park, Jung Hwa, Hyung Bum Seo, Byung Tae Choi, and Hwa Kyoung Shin
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ELECTROACUPUNCTURE , *BLOOD-brain barrier disorders , *CEREBRAL edema , *LABORATORY mice , *REACTIVE oxygen species , *TIGHT junctions - Abstract
Background: Electroacupuncture (EA) is a modern application based on combination of traditional manual acupuncture and electrotherapy that is frequently recommended as an adjuvant treatment for ischemic stroke. EA preconditioning can ameliorate blood-brain barrier (BBB) dysfunction and brain edema in ischemia-reperfusion injury; however, its mechanism remains unclear. This study investigated the preventive effects of EA preconditioning, particularly on BBB injury, followed by a transient middle cerebral artery occlusion (MCAO) model in mice. Results: Mice were treated with EA (20 min) at Baihui (GV20) and Dazhui (GV14) acupoints once a day for 3 days before ischemic injury. Infarct volume, neurological deficits, oxidative stress, Evans blue leakage and brain edema were evaluated at 24 h after ischemia-reperfusion injury. EA preconditioning significantly decreased infarct volume and improved neurological function even after ischemic injury. In addition, both Evans blue leakage and water content were significantly reduced in EA preconditioned mice. Whereas the expression of tight junction proteins, ZO-1 and claudin-5, were remarkably increased by EA preconditioning. Mice with EA preconditioning showed the reduction of astrocytic aquaporin 4, which is involved in BBB permeabilization. In addition, we found that EA preconditioning decreased reactive oxygen species (ROS) in brain tissues after ischemic injury. The expression of NADPH oxidase 4 (NOX4), not NOX2, was significantly suppressed in EA preconditioned mice. Conclusions: These results suggest that EA preconditioning improve neural function after ischemic injury through diminishing BBB disruption and brain edema. And, the reduction of ROS generation and NOX4 expression by EA preconditioning might be involved in BBB recovery. Therefore, EA may serve as a potential preventive strategy for patients at high risk of ischemic stroke. [ABSTRACT FROM AUTHOR]
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- 2016
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12. Pre-conditioning with transcranial low-level light therapy reduces neuroinflammation and protects blood-brain barrier after focal cerebral ischemia in mice.
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Hae In Lee, Jung Hwa Park, Min Young Park, Nam Gyun Kim, Kyoung-Jun Park, Byung Tae Choi, Yong-II Shin, and Hwa Kyoung Shin
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NEURITIS , *BLOOD-brain barrier , *IMMUNOFLUORESCENCE , *LABORATORY mice , *THERAPEUTICS ,ANIMAL models of cerebral ischemia ,CEREBRAL ischemia treatment - Abstract
Purpose: Transcranial low-level light therapy (LLLT) has gained interest as a non-invasive, inexpensive and safe method of modulating neurological and psychological functions in recent years. This study was designed to examine the preventive effects of LLLT via visible light source against cerebral ischemia at the behavioral, structural and neurochemical levels. Methods: The mice received LLLT twice a day for 2 days prior to photothrombotic cortical ischemia. Results: LLLT significantly reduced infarct size and edema and improved neurological and motor function 24 h after ischemic injury. In addition, LLLT markedly inhibited Iba-1- and GFAP-positive cells, which was accompanied by a reduction in the expression of inflammatory mediators and inhibition of MAPK activation and NF-κB translocation in the ischemic cortex. Concomitantly, LLLT significantly attenuated leukocyte accumulation and infiltration into the infarct perifocal region. LLLT also prevented BBB disruption after ischemic events, as indicated by a reduction of Evans blue leakage and water content. These findings were corroborated by immunofluorescence staining of the tight junction-related proteins in the ischemic cortex in response to LLLT. Conclusions: Non-invasive intervention of LLLT in ischemic brain injury may provide a significant functional benefit with an underlying mechanism possibly being suppression of neuroinflammation and reduction of BBB disruption. [ABSTRACT FROM AUTHOR]
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- 2016
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13. PMC-12, a Prescription of Traditional Korean Medicine, Improves Amyloid β-Induced Cognitive Deficits through Modulation of Neuroinflammation.
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Min Young Park, Yeon Suk Jung, Jung Hwa Park, Young Whan Choi, Jaewon Lee, Cheol Min Kim, Jin Ung Baek, Byung Tae Choi, and Hwa Kyoung Shin
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PHYTOTHERAPY , *COGNITION disorders diagnosis , *ALZHEIMER'S disease diagnosis , *AMYLOIDOSIS diagnosis , *PROTEINS , *NONSTEROIDAL anti-inflammatory agents , *DATA analysis , *RESEARCH funding , *FISHER exact test , *LEARNING , *CYCLOOXYGENASE 2 , *DESCRIPTIVE statistics , *PLANT extracts , *MICE , *CELL culture , *PHYSICIAN practice patterns , *ALTERNATIVE medicine , *ASIAN medicine , *ANIMAL experimentation , *WESTERN immunoblotting , *ANALYSIS of variance , *DRUG prescribing , *INFLAMMATION - Abstract
PMC-12 is a prescription used in traditional Korean medicine that consists of a mixture of four herbal medicines, Polygonum multiflorum, Rehmannia glutinosa, Polygala tenuifolia, and Acorus gramineus, which have been reported to have various pharmacological effects on age-related neurological diseases. In the present study, we investigated whether PMC-12 improves cognitive deficits associated with decreased neuroinflammation in an amyloid-β-(Aβ-) induced mouse model and exerts the antineuroinflammatory effects in lipopolysaccharide-(LPS-) stimulated murine BV2 microglia. Intracerebroventricular injection of Aβ25-35 in mice resulted in impairment in learning and spatial memory, whereas this was reversed by oral administration of PMC-12 (100 and 500 mg/kg/day) in dose-dependent manners. Moreover, PMC-12 reduced the increase of Aβ expression and activation of microglia and astrocytes in the Aβ25-35-injected brain. Furthermore, quantitative PCR data showed that inflammatory mediators were significantly decreased by administration of PMC-12 in Aβ -injected brains. Consistent with the in vivo data, PMC- 12 significantly reduced the inflammatory mediators in LPS-stimulated BV2 cells without cell toxicity. Moreover, PMC-12 exhibited anti-inflammatory properties via downregulation of ERK, JNK, and p38 MAPK pathways. These findings suggest that the protective effects of PMC-12 may be mediated by its antineuroinflammatory activities, resulting in the attenuation of memory impairment; accordingly, PMC-12 may be useful in the prevention and treatment of AD. [ABSTRACT FROM AUTHOR]
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- 2015
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14. Thread Embedding Acupuncture Inhibits Ultraviolet B Irradiation-Induced Skin Photoaging in Hairless Mice.
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Yoon-Jung Kim, Ha-Neui Kim, Mi-Sook Shin, and Byung-Tae Choi
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ACUPUNCTURE , *ANIMAL experimentation , *COMPARATIVE studies , *IMMUNOHISTOCHEMISTRY , *MICE , *SKIN , *SKIN aging , *T-test (Statistics) , *ULTRAVIOLET radiation , *WESTERN immunoblotting , *DATA analysis software , *DESCRIPTIVE statistics , *MATRIX metalloproteinases - Abstract
Thread embedding acupuncture (TEA) is an acupuncture treatment applied to many diseases in Korean medical clinics because of its therapeutic effects by continuous stimulation to tissues. It has recently been used to enhance facial skin appearance and antiaging, but data from evidence-based medicine are limited. To investigate whether TEA therapy can inhibit skin photoaging by ultraviolet B (UVB) irradiation, we performed analyses for histology, histopathology, in situ zymography and western blot analysis in HR-1 hairless mice. TEA treatment resulted in decreased wrinkle formation and skin thickness (Epidermis; P = 0.001 versus UV) in UVB irradiated mice and also inhibited degradation of collagen fibers (P = 0.010 versus normal) by inhibiting proteolytic activity of gelatinase matrix-metalloproteinase-9 (MMP-9). Western blot data showed that activation of c-Jun N-terminal kinase (JNK) induced by UVB (P = 0.002 versus normal group) was significantly inhibited by TEA treatment (P = 0.005 versus UV) with subsequent alleviation of MMP-9 activation (P = 0.048 versus UV). These results suggest that TEA treatment can have anti-photoaging effects on UVB-induced skin damage by maintenance of collagen density through regulation of expression of MMP-9 and related JNK signaling. Therefore, TEA therapy may have potential roles as an alternative treatment for protection against skin damage from aging. [ABSTRACT FROM AUTHOR]
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- 2015
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15. Neuroprotective effect of 1-methoxyoctadecan-1-ol from Uncaria sinensis on glutamate-induced hippocampal neuronal cell death.
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Sung Min Ahn, Ha Neui Kim, Yu Ri Kim, Eun Young Oh, Young Whan Choi, Hwa Kyoung Shin, and Byung Tae Choi
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CELL metabolism , *REACTIVE oxygen species , *CELL physiology , *FLOW cytometry , *GLUTAMIC acid , *ASIAN medicine , *WESTERN immunoblotting , *PLANT extracts , *OXIDATIVE stress - Abstract
Ethnopharmacological relevance We isolated a single compound, 1-methoxyoctadecan-1-ol (MOD), from dried hooks and stems of Uncaria sinensis, which is used in traditional Korean medicine to provide relief from various nervous related symptoms. Materials and methods Neuroprotective effects of MOD against glutamate-induced oxidative stress in HT22 cells were investigated by analyzing cell viability, lactate dehydrogenase, flow cytometry, reactive oxygen species (ROS) and Western blot assays. Results Exposure to glutamate alone resulted in remarkable hippocampal neuronal cell death; however, pretreatment with MOD resulted in suppression of neuronal death and ROS accumulation in connection with cellular Ca2+ level after exposure to glutamate. Stimulation by glutamate also caused significant protein level of phosphorylated p38 mitogen-activated protein kinases (MAPK), and dephosphorylated phosphatidylinositol-3 kinase (PI3K), however, pretreatment with MOD resulted in inhibition of these changes in protein level. Treatment with glutamate alone led to suppressed protein level of mature brain-derived neurotrophic factor (BDNF) and phosphorylated cAMP response element binding protein (CREB); however, pretreatment with MOD resulted in significant enhancement of this level of protein. Anti-oxidant N-acetyl-L-cysteine and both Ca2+ inhibitors, BAPTA and EGTA, showed effects similar to those of MOD in all proteins examined, except mature BDNF. Conclusions Our results suggest that MOD mainly exerted neuroprotective effects in suppression of ROS accumulation and up-regulation of mature BDNF in association with p38 MAPK and PI3K signaling in hippocampal neuronal cells. [ABSTRACT FROM AUTHOR]
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- 2014
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16. Gastrodia elata Shows Neuroprotective Effects via Activation of PI3K Signaling against Oxidative Glutamate Toxicity in HT22 Cells.
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Ye Jin Han, Ju Hui Je, So Hyoung Kim, Sung Min Ahn, Ha Neui Kim, Yu Ri Kim, Young Whan Choi, Hwa Kyoung Shin, and Byung Tae Choi
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REACTIVE oxygen species , *ANIMAL experimentation , *CELLULAR signal transduction , *FLOW cytometry , *LACTATE dehydrogenase , *MEDICINAL plants , *MICE , *RESEARCH funding , *T-test (Statistics) , *WESTERN immunoblotting , *PLANT extracts , *OXIDATIVE stress , *NEUROPROTECTIVE agents , *DATA analysis software , *ACETYLCYSTEINE , *DESCRIPTIVE statistics , *PHARMACODYNAMICS - Abstract
Dried roots of Gastrodia elata have traditionally been used in Korean medicine for the treatment of neurological disorders such as scotodinia, paralysis, and epilepsy. In our study, we attempted to investigate the neuroprotective effects of methanol extract from G. elata (MEGE) against glutamate-mediated oxidative stress and to explore underlying neuroprotective mechanisms. Analyses for cell viability, lactate dehydrogenase (LDH), flow cytometry, Western blot, and reactive oxygen species (ROS) were performed in HT22 hippocampal cells. Pretreatment with MEGE resulted in a potent neuroprotective effect against oxidative glutamate toxicity and these effects were exerted mainly by the abrogation of glutamate-induced apoptotic death. Treatment with glutamate resulted in a significant expression of both phosphorylated p38 and dephosphorylated phosphatidylinositol-3-kinase (PI3K). However, pretreatment with MEGE resulted in the inhibition of these expressions. In the inhibitor studies, treatment with PI3K inhibitor LY294002 resulted in the abrogation of the neuroprotective effect of MEGE. In addition, pretreatment with MEGE also resulted in the suppression of the glutamate-induced production of ROS. Treatment with MEGE and anti-oxidant N-acetyl-L-cysteine (NAC) resulted in the enhanced phosphorylation of both PI3K and cAMP responsive element binding protein (CREB), and, in particular, treatment with MEGE resulted in significantly enhanced expression of mature brain-derived neurotrophic factor (BDNF). These results suggest that the extract from G. elata mainly exerted neuroprotective effects through the up-regulation of the PI3K signaling pathway in association with BDNF and may be a useful therapeutic agent for treatment of oxidative neuronal death. [ABSTRACT FROM AUTHOR]
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- 2014
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17. Hexane extracts of Polygonum multiflorum improve tissue and functional outcome following focal cerebral ischemia in mice.
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SOO VIN LEE, KYUNG HA CHOI, YOUNG WHAN CHOI, JIN WOO HONG, JIN UNG BAEK, BYUNG TAE CHOI, and HWA KYOUNG SHIN
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HEXANE , *POLYGONUM , *CEREBRAL ischemia , *ENDOTHELIAL cells , *LABORATORY mice - Abstract
Polygonum multiflorum is a traditional Korean medicine that has been utilized widely in East Asian countries as a longevity agent. Clinical studies have demonstrated that Polygonum multiflorum improves hypercholesterolemia, coronary heart disease, neurosis and other diseases commonly associated with aging. However, scientific evidence defining the protective effects and mechanisms of Polygonum multiflorum against ischemic stroke is incomplete. In the present study, we investigated the cerebrovascular protective effects of Polygonum multiflorum against ischemic brain injury using an in vivo photothrombotic mouse model. To examine the underlying mechanism of action, we utilized an in vitro human brain microvascular endothelial cell (HBMEC) culture system. Hexane extracts (HEPM), ethyl acetate extracts (EAEPM) and methanol extracts (MEPM) of Polygonum multiflorum (100 mg/kg) were administered intraperitone-ally 30 min prior to ischemic insult. Focal cerebral ischemia was induced in C57BL/6J mice and endothelial nitric oxide synthase knockout (eNOS KO) mice by photothrombotic cortical occlusion. We evaluated the infarct volume, as well as neurological and motor function, 24 h after ischemic brain injury. Following ischemic insult, HEPM induced a significant reduction in infarct volume and subsequent neurological deficits, compared with EAEPM and MEPM. HEPM significantly decreased infarct size and improved neurological and motor function, which was not observed in eNOS KO mice, suggesting that this cerebroprotective effect is primarily an eNOS-dependent mechanism. In vitro, HEPM effectively promoted NO production, however these effects were inhibited by the NOS inhibitor, L-NAME and the PI3K/Akt inhibitor, LY-294002. Furthermore, HEPM treatment resulted in increased phosphorylation-dependent activation of Akt and eNOS in HBMEC, suggesting that HEPM increased NO production via phosphorylation-dependent activation of Akt and eNOS. In conclusion, HEPM prevents cerebral ischemic damage through an eNOS-dependent mechanism, and thus may have clinical applications as a protective agent against neurological injury in stroke. [ABSTRACT FROM AUTHOR]
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- 2014
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18. Apoptosis Induction of Human Prostate Carcinoma DU145 Cells by Diallyl Disulfide via Modulation of JNK and PI3K/AKT Signaling Pathways.
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Dong Yeok Shin, Gi-Young Kim, Jun Hyuk Lee, Byung Tae Choi, Young Hyun Yoo, and Yung Hyun Choi
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PROSTATE cancer , *APOPTOSIS , *DIALLYL disulfide , *MITOGEN-activated protein kinases , *MEMBRANE potential , *MITOCHONDRIAL membranes - Abstract
Diallyl disulfide (DADS), a sulfur compound derived from garlic, has various biological properties, such as anticancer, antiangiogenic and anti-inflammatory effects. However, the mechanisms of action underlying the compound's anticancer activity have not been fully elucidated. In this study, the apoptotic effects of DADS were investigated in DU145 human prostate carcinoma cells. Our results showed that DADS markedly inhibited the growth of the DU145 cells by induction of apoptosis. Apoptosis was accompanied by modulation of Bcl-2 and inhibitor of apoptosis protein (IAP) family proteins, depolarization of the mitochondrial membrane potential (MMP, ??m) and proteolytic activation of caspases. We also found that the expression of death-receptor 4 (DR4) and Fas ligand (FasL) proteins was increased and that the level of intact Bid proteins was down-regulated by DADS. Moreover, treatment with DADS induced phosphorylation of mitogen-activated protein kinases (MAPKs), including extracellular-signal regulating kinase (ERK), p38 MAPK and c-Jun N-terminal kinase (JNK). A specific JNK inhibitor, SP600125, significantly blocked DADS-induced-apoptosis, whereas inhibitors of the ERK (PD98059) and p38 MAPK (SB203580) had no effect. The induction of apoptosis was also accompanied by inactivation of phosphatidylinositol 3-kinase (PI3K)/Akt and the PI3K inhibitor LY29004 significantly increased DADS-induced cell death. These findings provide evidence demonstrating that the proapoptotic effect of DADS is mediated through the activation of JNK and the inhibition of the PI3K/Akt signaling pathway in DU145 cells. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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19. Electroacupuncture Confers Antinociceptive Effects via Inhibition of Glutamate Transporter Downregulation in Complete Freund's Adjuvant-Injected Rats.
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Ha-Neui Kim, Yu-Ri Kim, Ji-Yeon Jang, Hwa-Kyoung Shin, and Byung-Tae Choi
- Abstract
When we evaluated changes of glial fibrillary acidic protein (GFAP) and two glutamate transporter (GTs) by immunohistochemistry, expression of GFAP showed a significant increase in complete Freund's adjuvant (CFA)-injected rats; however, this expression was strongly inhibited by electroacupuncture (EA) stimulation. Robust downregulation of glutamate-aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) was observed in CFA-injected rats; however, EA stimulation resulted in recovery of this expression. Double-labeling staining showed co-localization of a large proportion of GLAST or GLT-1 with GFAP. UsingWestern blot, we confirmed protein expression of two GTs, but no differences in the mRNA content of these GTs were observed. Because EA treatment resulted in strong inhibition of CFA-induced proteasome activities, we examined the question of whether thermal sensitivities and GTs expression could be regulated by proteasome inhibitor MG132. CFA-injected rats cotreated with EA and MG132 showed a significantly longer thermal sensitivity, compared with CFA-injected rats with or without MG132. Both EA and MG132 blocked CFA-induced GLAST and GLT-1 downregulation within the spinal cord. These results provide evidence for involvement of GLAST and GLT-1 in response to activation of spinal astrocytes in an EA antinociceptive effect. Antinociceptive effect of EA may be induced via proteasome-mediated regulation of spinal GTs. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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20. Effects of Electroacupuncture on N- Methyl-D-aspartate Receptor-Related Signaling Pathway in the Spinal Cord of Normal Rats.
- Author
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Ha-Neui Kim, Yu-Ri Kim, Ji-Yeon Jang, Hwa-Kyoung Shin, and Byung-Tae Choi
- Abstract
This study examined the influence of the N-methyl-D-aspartate receptor (NMDAR) on the modulation of related spinal signaling after electroacupuncture (EA) treatment in normal rats. Bilateral 2Hz EA stimulations (1-2-3.0mA) were delivered at acupoints corresponding to Zusanli (ST36) and Sanyinjiao (SP6) in men for 30 min. Thermal sensitization was strongly inhibited by EA, but this analgesia was reduced by preintrathecal injection of the NMDAR antagonist, MK801. Phosphorylation of the NMDAR NR2B subunit, cA MP response element-binding protein (CREB), and especially phosphatidylinositol 3-kinase (PI3K) were significantly induced by EA. However, these marked phosphorylations were not observed in MK801-pretreated rats. EA analgesia was reduced by preintrathecal injection with the calcium chelators Quin2 and T MB8, similar to the results evident using MK801. Phosphorylation of PI3K and CREB induced by EA was also inhibited by T MB8. Calcium influx by NMDAR activation may play an important role in EA analgesia of normal rats through the modulation of the phosphorylation of spinal PI3K and CREB. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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21. Implication of Snail in Metabolic Stress-Induced Necrosis.
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Cho Hee Kim, Hyun Min Jeon, Su Yeon Lee, Min Kyung Ju, Ji Young Moon, Hye Gyeong Park, Mi-Ae Yoo, Byung Tae Choi, Jong In Yook, Sung-Chul Lim, Song Iy Han, and Ho Sung Kang
- Subjects
- *
NECROSIS , *GANGRENE , *BLOOD plasma , *CEREBRAL anoxia , *MITOCHONDRIAL membranes , *CANCER invasiveness - Abstract
Background: Necrosis, a type of cell death accompanied by the rupture of the plasma membrane, promotes tumor progression and aggressiveness by releasing the pro-inflammatory and angiogenic cytokine high mobility group box 1. It is commonly found in the core region of solid tumors due to hypoxia and glucose depletion (GD) resulting from insufficient vascularization. Thus, metabolic stress-induced necrosis has important clinical implications for tumor development; however, its regulatory mechanisms have been poorly investigated. Methodology/Principal Findings: Here, we show that the transcription factor Snail, a key regulator of epithelialmesenchymal transition, is induced in a reactive oxygen species (ROS)-dependent manner in both two-dimensional culture of cancer cells, including A549, HepG2, and MDA-MB-231, in response to GD and the inner regions of a multicellular tumor spheroid system, an in vitro model of solid tumors and of human tumors. Snail short hairpin (sh) RNA inhibited metabolic stress-induced necrosis in two-dimensional cell culture and in multicellular tumor spheroid system. Snail shRNA-mediated necrosis inhibition appeared to be linked to its ability to suppress metabolic stress-induced mitochondrial ROS production, loss of mitochondrial membrane potential, and mitochondrial permeability transition, which are the primary events that trigger necrosis. Conclusions/Significance: Taken together, our findings demonstrate that Snail is implicated in metabolic stress-induced necrosis, providing a new function for Snail in tumor progression. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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22. The Traditional Herbal Medicine, Dangkwisoo-San, Prevents Cerebral Ischemic Injury through Nitric Oxide-Dependent Mechanisms.
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Ji Hyun Kim, Sun Haeng Park, Young Whan Kim, Jung Min Ha, Sun Sik Bae, Guem San Lee, Su In Cho, Byung Tae Choi, and Hwa Kyoung Shin
- Abstract
Dangkwisoo-San (DS) is an herbal extract that is widely used in traditional Korean medicine to treat traumatic ecchymosis and pain by promoting blood circulation and relieving blood stasis. However, the effect of DS in cerebrovascular disease has not been examined experimentally. The protective effects of DS on focal ischemic brain were investigated in a mouse model. DS stimulated nitric oxide (NO) production in human brain microvascular endothelial cells (HBMECs). DS (10-300 µg/mL) produced a concentration-dependent relaxation in mouse aorta, which was significantly attenuated by the nitric oxide synthase (NOS) inhibitor L-NAME, suggesting that DS causes vasodilation via a NO-dependent mechanism. DS increased resting cerebral blood flow (CBF), although it caused mild hypotension. To investigate the effect of DS on the acute cerebral injury, C57/BL6J mice received 90min of middle cerebral artery occlusion followed by 22.5 h of reperfusion. DS administered 3 days before arterial occlusion significantly reduced cerebral infarct size by 53.7% compared with vehicle treatment. However, DS did not reduce brain infarction in mice treated with the relatively specific endothelialNOS (eNOS) inhibitor,N5-(1-iminoethyl)-L-ornithine, suggesting that the neuroprotective effect of DS is primarily endothelium-dependent. This correlated with increased phosphorylation of eNOS in the brains of DS-treated mice. DS acutely improves CBF in eNOS-dependent vasodilation and reduces infarct size in focal cerebral ischemia. These data provide causal evidence that DS is cerebroprotective via the eNOS-dependent production of NO, which ameliorates blood circulation. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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23. Partially purified Curcuma longa inhibits alpha-melanocyte-stimulating hormone-stimulated melanogenesis through extracellular signal-regulated kinase or Akt activation-mediated signalling in B16F10 cells.
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Ji Yeon Jang, Jun Hyuk Lee, Seong Yun Jeong, Kyung Tae Chung, Yung Hyun Choi, and Byung Tae Choi
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- *
MELANOCYTES , *MELANOGENESIS , *TURMERIC , *CHROMATOGRAPHIC analysis , *PROTEINS , *PROTEIN kinases - Abstract
Bioassay-guided fractionation of Curcuma longa by solvent partitioning and purification with octadecylsilane open column chromatography yielded a partial purification. The active 80% methanol chromatographic fraction from the ethyl acetate layer [partial purification from C. longa (PPC)] was used to investigate the alpha-melanocyte-stimulating hormone (α-MSH)-stimulated melanogenesis signal pathway in B16F10 cells. In cells stimulated α-MSH, PPC inhibited cellular melanin contents, tyrosinase activity and expression of melanogenesis-related proteins including microphthalmia-associated transcription factor (MITF), tyrosinase and tyrosinase-related proteins (TRP). Melanogenesis-regulating signalling such as mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinase (PI3K)/Akt was activated by PPC in α-MSH-stimulated B16F10 cells. The suppressive activity of PPC on α-MSH-induced melanogenesis was abrogated by selective inhibition of MEK/ERK (PD98059) and PI3K (LY294002). MEK/ERK or Akt activation by PPC may contribute to reduced melanin synthesis via MITF and its downstream signal pathway including tyrosinase and TRPs in α-MSH-induced melanogenesis. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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24. Dichloromethane fraction of Cimicifuga heracleifolia decreases the level of melanin synthesis by activating the ERK or AKT signaling pathway in B16F10 cells.
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Ji Yeon Jang, Jun Hyuk Lee, Byoung Won Kang, Kyung Tae Chung, Yung Hyun Choi, and Byung Tae Choi
- Subjects
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BUGBANE , *PLANT extracts , *MELANOGENESIS , *GLUTAMIC acid , *PLANT pigments , *DICHLOROMETHANE , *THERAPEUTICS - Abstract
Cimicifuga rhizoma has long been used in traditional Korean medicine. In particular, a Cimicifuga heracleifolia extract (CHE) was reported to inhibit the formation of glutamate and the glutamate dehydrogenase activity in cultured rat islet. Glutamate activates melanogenesis by activating tyrosinase. Accordingly, it was hypothesized that a CHE might inhibit the melanogenesis-related signal pathways including the inhibition of microphthalmia-associated transcription factor (MITF)-tyrosinase signaling and/or the activation of extracellular signal-regulated kinase (ERK)-Akt signaling. The results showed that CHE inhibits the cellular melanin contents, tyrosinase activity and expression of melanogenesis-related proteins including MITF, tyrosinase and tyrosinase-related protein (TRP)s in α-melanocyte-stimulating hormone-stimulated B16 cells. Moreover, CHE phosphorylates MEK, ERK1/2 and Akt, which are melanogenesis inhibitory proteins. The data suggest that CHE inhibits melanogenesis signaling by both inhibiting the tyrosinase directly and activating the MEK-ERK or Akt signal pathways-mediated suppression of MITF and its downstream signal pathway, including tyrosinase and TRPs. Therefore, C. heracleifolia would be a useful therapeutic agent for treating hyperpigmentation and an effective component in whitening and/or lightening cosmetics. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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25. Electroacupuncture Inhibits Inflammatory Edema and Hyperalgesia Through Regulation of Cyclooxygenase Synthesis in Both Peripheral and Central Nociceptive Sites.
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Jun-Hyuk Lee, Kyung-Jeon Jang, Yong-Tae Lee, Yung-Hyun Choi, and Byung-Tae Choi
- Subjects
- *
ELECTROACUPUNCTURE , *EDEMA , *HYPERALGESIA , *NITRIC oxide , *PROSTAGLANDINS - Abstract
We investigated the anti-inflammatory effects of electroacupuncture (EA) on carrageenan-induced inflammatory model in association with peripheral and spinal COX-2 expression. EA with 2, 15 and 120 Hz, especially 2 Hz, had significant inhibitory effects on the developing of edema and hyperalgesia, which was measured in 30-min intervals after carrageenan injection. Therefore, we investigated whether the effect of 2 Hz EA on carrageenan-induced edema and hyperalgesia is associated with peripheral and spinal expression of inflammatory proteins. The expression of cyclooxygenase (COX)-1, COX-2, and inducible nitric oxide synthase (iNOS) was inhibited by 2 Hz EA in carrageenan-injected rat paws. Interestingly, we found that the mRNA of COX-1 and COX-2 expression in the spine was not induced by 2 Hz EA treatment after carrageenan-induced peripheral inflammation. In addition, synthesis of prostaglandin E2 (PGE2) was partially inhibited by 2 Hz EA treatment in both peripheral and spinal nociceptive regions. In conclusion, EA treatment might be a useful therapy for mitigation of inflammatory edema and hyperalgesia through regulation of COX-2 expression in both peripheral and central nociceptive sites. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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26. Partial Characterization and Immunostimulatory Effect of a Novel Polysaccharide–Protein Complex Extracted from Phellinus linteus.
- Author
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Gi-Young Kim, Jae-Yoon Lee, Jeong-Ok Lee, Chung-Ho Ryu, Byung Tae Choi, Yong-Ki Jeong, Ki-Wan Lee, Sang-Chul Jeong, and Yung Hyun Choi
- Subjects
- *
POLYSACCHARIDES , *BIOPOLYMERS , *PHELLINUS , *HYMENOCHAETACEAE , *IMMUNOLOGICAL adjuvants , *IMMUNOMODULATORS , *T cells , *B cells - Abstract
The article presents a study that examines partial characterization and immunostimulatory effect of a novel polysaccharide-protein complex (PPC) extracted from Phellinus linteus. The study authors have demonstrated that a novel PPC was a potent immunomodulator. Based on the results, PPC was found to markedly increase the proliferation of B cells, but not T cells. Results suggest that PPC stimulated the tumoricidal activities of macrophages and natural killer cells, and induced the proliferation of B cells in vitro.
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- 2006
- Full Text
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