• Archives of Pharmacal Research
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• 제23권4호
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• pp.413-417
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• 2000

The effect of ischemia/reperfusion-induced neuronal damage on the memory impairment were investigated using active avoidance and Morris water maze tasks in Wistar rats. Focal ischemia was induced by 1 h occlusion of the right middle cerebral artery (MCA) of Wistar male rats. Reperfusion was induced by releasing the occlusion and restoring the blood circulation for 24 h. The acquisition and preservation memory tested by active avoidance showed a significant difference between the sham and ischemia/reperfusion group. The water maze acquisition performance was also significant difference between sham and ischemia/repefusion groups in both latency and moving distance. The infarction volume was increased by the ischemia/reperfusion. Furthermore, the cresyl violet staining of the ischemia/reperfusion brain showed severe neuronal damage (pyramidal cell loss) in the cortex in addition to the striatum lesion of brain. This study shows that pyramidal cell damage in the cortex lesion may be partially related to memorial disturbance in the ischemia/reperfusion brain injury.

• 대한본초학회지
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• 제25권2호
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• pp.71-79
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• 2010

Objectives : In this study, the neuroprotective effects of modified Boyanghwano-Tang (mBHT) and the major medicinal plants, Astragali Radix(AR) and Salviae Miltiorrhizae Radix(SMR) were investigated in transient middle cerebral artery occlusion (tMCAO)-induced ischemic stroke of rats. Methods : mBHT(400 mg/kg) and AR(154 mg/kg) or SMR(62 mg/kg) water extract orally injected in rats after 90 min occlusion of MCA and then allow reperfusion to 24 h. Brain infarction was measured by TTC staining and the expressions of NOS isoforms and apoptotic molecules were determined in ischemic brain by Western blot. Results : The results showed that mBHT has stronger neuropreotective property through inhibitions of the PARP cleaved and caspase-3 activation in ischemic rats, and could reduced infarction volumes comparison of those of AR or SMR, respectively. While, AR extract has an angiogenic property through increasing the expressions of eNOS and VEGF, and SMR extract has a strong anti-inflammatory effects through inhibition of iNOS expression in ischemic brains. Conclusions : These results suggest that mBHT has multifactorial therapeutic advantages through anti-apoptosis, anti-inflammation and angiogenesis for ischemic stroke based on a synergistic combination of ingradients rather than monotherapy.

• The Korean Journal of Physiology and Pharmacology
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• 제4권1호
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• pp.73-79
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• 2000

This study investigated whether propofol, an intravenous, non-barbiturate anesthetic, could reduce brain damage following global forebrain ischemia. Transient global ischemia was induced in gerbils by occlusion of bilateral carotid arteries for 3 min. Propofol (50 mg/kg) was administered intraperitoneally 30 min before, immediately after, and at 1 h, 2 h, 6 h after occlusion. Thereafter, propofol was administered twice daily for three days. Treated animals were processed in parallel with ischemic animals receiving 10% intralipid as a vehicle or with sham-operated controls. In histologic findings, counts of viable neurons were made in the pyramidal cell layer of the hippocampal CA1 area 4 days after ischemia. The number of viable neurons in the pyramidal cell layer of CA1 area was similar in animals treated with a vehicle or a subanesthetic dose of propofol. In terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) assay, semiquantitative analysis of dark-brown neuronal cells was made in the hippocampal CA1 area. There was no significant difference in the degree of TUNEL staining in the hippocampal CA1 area between vehicle-treated and propofol-treated animals. These results show that subanesthetic dose of propofol does not reduce delayed neuronal cell death following transient global ischemia in Mongolian gerbils.

• Journal of Mechanical Science and Technology
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• 제19권6호
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• pp.1313-1320
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• 2005

Stenosed coronary artery may play an important role in various coronary heart diseases. However, it has not been known how much stenosed coronary artery affects coronary circulation system, quantitatively. The present study developed a mathematical model for microcirculation in the left common coronary artery (LCCA) with adopting a previously measured morphological data and mechanical properties of the coronary vessels. We examine the effect of percent diameter stenosis on blood flow rate and shear stress for two cases. Case I comprised of one-stenosed element at $10^{th}$ order ($\%$ diameter stenosis are 10, 30, and 50, respectively). Case II consisted of completely occluded element at $10^{th}$ order (number of occluded elements are 0, 1, and 2 out of 8, respectively). As the level of stenosis becomes severe, the shear stress increases significantly but the flow rate reduction was relatively small. However, for the occluded case, there was linearly proportional reduction of flow rate according to number of occluded elements. Either such high shear stress associated with coronary artery stenosis or reduced flow rate due to occlusion may cause atherosclerosis and myocardial ischemia.

• 대한한의학회지
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• 제39권4호
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• pp.1-15
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• 2018

Objectives: Cerebral ischemia results from a variety of causes that cerebral blood flow is reduced due to a transient or permanent occlusion of cerebral arteries. Reactive astrocytes and microglial activation plays an important role in the neuronal cell death during ischemic insult. Acupunctural treatment is effective for symptom improvement in cerebrovascular accident, including cerebral ischemia. Methods: In the present study, the effects of acupuncture at the ST40 acupoint on short-term memory and apoptosis in the hippocampal CA1 region following transient global cerebral ischemia were investigated using gerbils. Transient global ischemia was induced by occlusion of both common carotid arteries with aneurysm clips for 5 min. Acupuncture stimulation was conducted once daily for 7 consecutive days, starting one day after surgery. Results: In the present results, ischemia induction deteriorated short term memory, increased apoptosis, and induced reactive astrocyte and microglial activation. Acupuncture at ST40 acupoint ameliorated ischemia-induced short-term memory impairment by suppressing apoptosis in the hippocampus through down-regulation of reactive astrocytes and microglial activation. Conclusion: The present study suggests that acupuncture at the ST40 acupoint can be used for treatment of patients with cerebral stroke.

• 대한약침학회지
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• 제26권4호
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• pp.357-365
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• 2023

Objectives: Since stroke is a serious health issue, novel therapeutic strategies are required. In a mouse model of ischemic stroke, this study analyzed the potential of electroacupuncture (EA) and tenuigenin (TE) to improve the efficacy of human mesenchymal stem cell (hMSC) transplantation. Methods: Middle cerebral artery occlusion (MCAO) with reperfusion was used to generate ischemic stroke. Forty-eight male C57BL/6 mice were randomly divided into five groups: control, MCAO-operated, MCAO-EA, MCAO-TE, or MCAO + EA + TE. Subsequently, hMSCs were transplanted into the ischemic region and EA, TE, or the combination was administered. Behavior assessments and immunohistochemistry were conducted to evaluate motor and cognitive recovery and hMSCs survival, migration, and differentiation. Results: The combined treatment of EA and TE exhibited enhanced hMSCs survival, migration and differentiation into neural cell lineages while suppressing astrocyte formation. Immunohistochemistry demonstrated increased neurogenesis through hMSCs transplantation in the ischemic brain. Immediate behavioral improvements were not significantly different between groups, but there was a gradual recovery in motor and cognitive function over time. Conclusion: These findings highlight the potential of EA and TE co-treatment as a therapeutic strategy for ischemic stroke, opening avenues for further research to optimize treatment protocols and elucidate underlying mechanisms.

• Journal of Periodontal and Implant Science
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• 제15권1호
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• pp.89-89
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• 1985

• 동의생리병리학회지
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• 제22권4호
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• pp.835-840
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• 2008

Acupuncture has long been contended to be effective in an ischemic stroke. A real-time monitoring of glutamate, an excitotoxin in the process of ischemic neuronal damage, in the striatum is tried in a rat model of global ischemia. Global ischemia was induced by the 11 vessel occlusion method for 10 minutes, during which acupuncture stimulation on GB34 and GB39 points was executed. Glutamate release in the rat striatum was monitored 256 times per second using real-time amperometric biosensor. Real time measurement data of 10 minutes prior to the induction of ischemia served as baseline data. Data acquisition continued for 30 minutes after the initiation of reperfusion. Peak concentration of glutamate release along with incidentally measured EEG and cerebral blood flow was compared between cases with and without acupuncture stimulation. Peak concentration of glutamate lowered when acupuncture stimulation was executed. A real time monitoring system of 11 vessel-occlusion induced global ischemia model was successfully established. The effect by acupuncture on acute global ischemia was successfully observed in this real-time monitoring setting, which may be one of the neuroprotective mechanism of acupuncture.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권3호
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• pp.229-237
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• 2000

According to the functional matrix theory, Delaire proposes that individual occlusal plane was determined by variable effects of teeth, maxilla, mandible, cranium, cranial base and soft tissue matrix including the orofacial musculature. and that there is the ideal occlusal plane determined by the most proper spatial position of maxilla and mandible, functionally and esthetically. This study was designed to find out the relation between Delaire's ideal occlusal plane and muscle activity of masticatory muscles in individuals who have normal maxillo-mandibular relationships. Lateral cephalometric radiographs were taken and his/her individual occlusal plane and ideal occlusal plane were analyzed with Delaire's architectural and structural craniofacial analytic method. For evaluation of muscle activities of masticatory muscles, electromyography of anterior temporal muscle, superficial masseter muscle, and anterior belly of digastric muscle was recorded in fifty Korean normal Angle class I occlusion individuals. According to the average value of ideal occlusal plane, fifty normal Angle class I occlusion individuals were classified into three groups: Ideal occlusal plane group(I group), hyperrotation group(I+ group) and hyporotation group(I- group). The result of this study was as follows: 1. The results of Delaire's architectural and structural craniofacial analysis of lateral cephalography of the fifty Korean normal Angle class I occlusion individuals are that twelve persons(24%) have consistent or parallel with ideal occlusal plane and the average of angular difference was $1.22^{\circ}{\pm}3.69^{\circ}$. 2. There is no significant difference in muscle activities of masticatory muscles during resting(p<0.05), but significant increases of muscle activity of ipsilateral anterior temporal and masseter muscle, contralateral anterior belly of digastric muscle during unilateral chewing and of anterior temporal and masseter muscle during bilateral clenching(p<0.05). 3. To find out the effect of the angular difference between Delaire's ideal occlusal plane and real occlusal plane to muscle activity, muscle activities of masticatory muscles were compared with three groups in each other; I group, I+ group and I- group. The results were no significant differences during resting, unilateral chewing and bilateral clenching.(p>0.05) 4. Although there is no significant differences of masticatory muscle activities among the three groups, the fact that increasing tendency of masseter muscle activity of ideal occlusal plane group(I+) than those of any other groups(I+ and I-) during bilateral clenching was noted. There is only the implication that occlusal plane makes some effects on masticatory muscle activities, espacially that of masseter muscle during bilateral clenching. In conclusion, the hypothesis that occlusal plane is one of the factors which affect the muscle activities of masticatory muscles and that anyone whose occlusal plane consistent with Delaire's ideal occlusal plane has an extraordinary functional advantage in masticatory muscle function cannot be proven with electromyography methods.

• The Journal of Advanced Prosthodontics
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• 제9권5호
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• pp.371-380
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• 2017

PURPOSE. The aim of this study is to evaluate and compare the stress distribution in Locator attachments in mandibular two-implant overdentures according to implant locations and different loading conditions. MATERIALS AND METHODS. Four three-dimensional finite element models were created, simulating two osseointegrated implants in the mandible to support two Locator attachments and an overdenture. The models simulated an overdenture with implants located in the position of the level of lateral incisors, canines, second premolars, and crossed implant. A 150 N vertical unilateral and bilateral load was applied at different locations and 40 N was also applied when combined with anterior load at the midline. Data for von Mises stresses in the abutment (matrix) of the attachment and the plastic insert (patrix) of the attachment were produced numerically, color-coded, and compared between the models for attachments and loading conditions. RESULTS. Regardless of the load, the greatest stress values were recorded in the overdenture attachments with implants at lateral incisor locations. In all models and load conditions, the attachment abutment (matrix) withstood a much greater stress than the insert plastic (patrix). Regardless of the model, when a unilateral load was applied, the load side Locator attachments recorded a much higher stress compared to the contralateral side. However, with load bilateral posterior alone or combined at midline load, the stress distribution was more symmetrical. The stress is distributed primarily in the occlusal and lateral surface of the insert plastic patrix and threadless area of the abutment (matrix). CONCLUSION. The overdenture model with lateral incisor level implants is the worst design in terms of biomechanical environment for the attachment components. The bilateral load in general favors a more uniform stress distribution in both attachments compared to a much greater stress registered with unilateral load in the load side attachments. Regardless of the implant positions and the occlusal load application site, the stress transferred to the insert plastic is much lower than that registered in the abutment.