• Journal of Korean Neurosurgical Society
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• v.43 no.6
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• pp.275-280
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• 2008

Objective : In order to assess the incidence of thromboembolic events and their clinical presentations, the present study prospectively examined routine brain magnetic resonance images (MRI) taken within 48 hours after a coil embolization of cerebral aneurysms. Methods : From January 2006 to January 2008, 163 cases of coil embolization of cerebral aneurysm were performed along with routine brain MRI, including diffusion-weighted magnetic resonance (DW-MR) imaging, within 48 hours after the embolization of the aneurysm to detect the silent thromboembolic events regardless of any neurological changes. If any neurological changes were observed, an immediate brain MRI follow-up was performed. High-signal-intensity lesions in the DW-MR images were considered as acute thromboembolic events and the number and locations of the lesions were also recorded. Results : Among the 163 coil embolization cases, 98(60.1%) showed high-signal intensities in the DW-MR imaging follow-up, 66 cases (67.0%) involved the eloquent area and only 6cases (6.0%) showed focal neurological symptoms correlated to the DW-MR findings. The incidence of DW-MR lesions was higher in older patients (${\geq}60$ yrs) when compared to younger patients (<60 yrs) (p=0.002, odd's ratio=1.043). The older patients also showed a higher incidence of abnormal DW-MR signals in aneurysm-unrelated lesions (p=0.0003, odd's ratio=5.078). Conclusion : The incidence of symptomatic thromboembolic attacks after coil embolization of the cerebral aneurysm was found to be lower than that reported in previous studies. While DW-MR imaging revealed a higher number of thromboembolic events, most of these were clinically silent and transient and showed favorable clinical outcomes. However, the incidence of DW-MR abnormalities was higher in older patients, along with unpredictable thromboembolic events on DW-MR images. Thus, in order to provide adequate and timely treatment and to minimize neurological sequelae, a routine DW-MR follow-up after coil embolization of cerebral aneurysms might be helpful, especially in older patients.

• Journal of Korean Neurosurgical Society
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• v.40 no.3
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• pp.143-147
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• 2006

Objective : Brachial plexus injury can produce a intractable chronic neuropathic pain. This study was undertaken to assess the long term outcome of microsurgical dorsal root entry zonotomy[MDT]. Methods : Between October 1997 and December 2002, 21 patients received MDT because of a intractable pain resulting from brachial plexus injury. Of these, 19 patients were followed for more than 2 years. Fourteen of 19 patients were male and patient ages ranged from 22 to 69 years. Mean pain duration was 36.8 months and all patients had severe pain of $9{\sim}10$ visual analogue scale. To achieve complete destruction of abnormal dorsal horns, thermocoagulation of the posterolateral sulcus were performed and careful gluing was done to prevent postoperative adhesion and pain recurrence. Results : Of the 19 patients, 15 patients had excellent [>75% reduction in pain] and good [$51{\sim}75%$ pain relief] results in a average postoperative period of 4.1 years. One patient had a poor [less than 25% pain relief] result. Three patients were considered to have a fair result [$26{\sim}50%$ pain relief]. Postoperative complications were 2 transient ipsilateral ataxia and 1 CSF fistula that resolved without surgical revision. Conclusion : These results indicate that MDT provides excellent long-term pain relief in medically intractable chronic neuropathic pain following brachial plexus injury without significant complications.

• Tuberculosis and Respiratory Diseases
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• v.67 no.1
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• pp.52-58
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• 2009

Pulmonary arteriovenous malformation (PAVM) is a rare pulmonary vascular anomaly due to an abnormal communication between the pulmonary artery and vein. The most common presenting symptom is a dyspnea on exertion related to this right-to-left shunt. If left untreated, PAVM has been known to result in serious complications. Incomplete pulmonary capillary network can be the cause of cerebral abscesses and other noninfectious neurological complications, such as stroke and transient ischemic attacks due to paradoxic embolism Transcatheter embolotherapy, using coils or balloons, has replaced surgical resection as the treatment of choice for PAVM. However, the risk of device embolization has limited the use of coil embolotherapy, while the size of PAVM is huge. Recently, Amplatzer$^{(R)}$ Vascular Plug has been proposed as an alternative endovascular occlusion device for arteriovenous malformation. We report a case of 81-year-old male patient with a giant PAVM, which was successfully treated by transcatheter embolotherapy using the Amplatzer$^{(R)}$ Vascular Plug.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.433-434
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• 2015

Dictionary meaning of circuit-breaker is a mechanical switching device, capable of making, carrying and breaking currents under normal circuit conditions and also making, carrying for a specified time and breaking currents under specified abnormal circuit conditions such as those of short circuit. and it had been recognized as being operated simultaneously. Controlled Switching System(CSS), which is technology for individual pole operation, are widely used to reduce transient phenomenon, for example switching surges, inrush current, for a all switching cases and nowadays it have become and economical solution for a switching place. The conventional solution to these problem is the use of pre-insertion resistors of $520{\Omega}$. However, it is recognised that the cost for products and maintenance are expensive and this apparatus makes more complex the circuit-breaker mechanism. Korea Electric Power Cooperation (KEPCO) has been study for relevant CCS technology since pilot application in substation in 2003 and plan to apply the actual power grid in 2017. This paper deals with the investigation of international CCS operation status and preview for application in KEPCO power grid.

• Journal of Yeungnam Medical Science
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• v.32 no.2
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• pp.152-154
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• 2015

Arrhythmias are complications of tunneled cuffed hemodialysis catheter insertion. Most complications associated with arrhythmias occur during guide-wire access, where the guide wire can cause traumatic damage to the conduction system of the heart. Conducting system injury in tunneled cuffed hemodialysis catheter insertion often involves the right bundle, causing right bundle branch block (RBBB). Transient RBBB with sinus rhythm is not usually accompanied by abnormal vital signs. However if patients already have left bundle branch block (LBBB), new onset RBBB can cause complete atrioventricular block (AVB), which can lead to fatal complications requiring invasive treatment. We report on a patient with LBBB who developed complete AVB during hemodialysis catheter insertion.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.222-227
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• 1997

To diagnose cardiac arrhythmia owing to reentry mechanism, cardiac conduction system was modeled by modified Hidden Markov modeled by evaluated. First, simulation of transient conduction states and output waves were made with initially assumed parametric values of cardiac muscle repolariztion time, conduction velocity and its automaticity. The output was a series of onset time and the name of the wave. Parameters determined the rate of beating, lengths of wave intervals, rate of abnormal beats, and the like. Several parameter sets were found to simulate normal sinus rhythm, supraventricular /ventricular tachycardia, atrial /vetricular extrasystole, etc. Then, utilizing the estimation theorems of Hidden Markov Model, the best conduction path was estimated given the previous output. With this modified estimation method, close matching between the simulated conduction path and the estimated one was confirmed.

• Korean Journal of Veterinary Research
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• v.59 no.2
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• pp.59-67
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• 2019

We investigated whether ${\beta}$-carotene (${\beta}-CA$) or ellagic acid (EA), originating from various fruits and vegetables, has a preventive effect against male infertility induced by exogenous scrotal hyperthermia. ICR adult mice were intraperitoneally treated with 10 mg/kg of ${\beta}-CA$ or EA daily for 13 days consecutively. During this time, mice were subjected to transient scrotal heat stress in a water bath at $43^{\circ}C$ for 20 min on day 7, and their testes and blood were obtained on day 14 for histopathologic and biochemical analyses. Heat stress induced significant testicular weight reduction, germ cell loss and degeneration, as well as abnormal localization of phospholipid hydroperoxide glutathione peroxidase (PHGPx) and manganese superoxide dismutase (MnSOD) in spermatogenic and Leydig cells. Heat stress also altered the levels of oxidative stress (lipid peroxidation, SOD activity, and PHGPx, MnSOD, and $HIF-1{\alpha}$ mRNAs), apoptosis (Bax, Bcl-xL, caspase 3, $NF-{\kappa}B$, and $TGF-{\beta}1$ mRNAs), and androgen biosynthesis (serological testosterone concentration and $3{\beta}$-hydroxysteroid dehydrogenase mRNA) in testes. These changes were all improved significantly by ${\beta}-CA$ treatment, but only slightly improved by EA treatment. These findings indicate that ${\beta}-CA$, through modulations of oxidative stress, apoptosis, and androgen biosynthesis, is a potent preventive agent against testicular injuries induced by scrotal hyperthermia.

• Toxicological Research
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• v.14 no.4
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• pp.547-555
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• 1998

The subchronic toxicity of a combined preparation of ticlopidine and ginkgo biloba extract (EGb 761) mixed in a ratio of 10: 4 was examined in male and female Sprague-Dawley rats. Rats were treated with the test substance at a dose of 52 mg/kg, 156 mg/kg, or 467 mg/kg intragastrically for 30 consecutive days. Control rats were treated with vehicle only. Each group consisted of 10 rats. No death or abnormal clinical signs were observed throughout the administration period. A transient decrease in body weight gain and food intake was observed in the rats treated with the high dose (467 mg/kg), which was recovered to normal in a week. There were no drug-related differences in urinalysis and hematological results. A significant increase in serum total cholesterol and total protein was observed in both sexes of the rats treated with a dose of 467 mg/kg daily, but all the other values obtained in serum chemistry appeared to be within normal range. A dose dependent increase in liver weight was observed in both male and female rats. Relative kidney weight was also increased in the high dose groups. There was no gross pathological finding at terminal sacrifice. Microscopic histopathological examination did not show any lesion in terms of correlation with administration of the test substance. The results suggest that under the conditions employed in this study no observable effect level (NOEL) of the test substance be 52 mg/kg/day.

• Journal of Ginseng Research
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• v.44 no.3
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• pp.442-452
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• 2020

Backgroud: Sleep deprivation (SD) impairs learning and memory by inhibiting hippocampal functioning at molecular and cellular levels. Abnormal autophagy and apoptosis are closely associated with neurodegeneration in the central nervous system. This study is aimed to explore the alleviative effect and the underlying molecular mechanism of stem-leaf saponins of Panax notoginseng (SLSP) on the abnormal neuronal autophagy and apoptosis in hippocampus of mice with impaired learning and memory induced by SD. Methods: Mouse spatial learning and memory were assessed by Morris water maze test. Neuronal morphological changes were observed by Nissl staining. Autophagosome formation was examined by transmission electron microscopy, immunofluorescent staining, acridine orange staining, and transient transfection of the tf-LC3 plasmid. Apoptotic event was analyzed by flow cytometry after PI/annexin V staining. The expression or activation of autophagy and apoptosis-related proteins were detected by Western blotting assay. Results: SLSP was shown to improve the spatial learning and memory of mice after SD for 48 h, accomanied with restrained excessive autophage and apoptosis, whereas enhanced activation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway in hippocampal neurons. Meanwhile, it improved the aberrant autophagy and apoptosis induced by rapamycin and re-activated phosphoinositide 3-kinase/Akt/mammalian target of rapamycin signaling transduction in HT-22 cells, a hippocampal neuronal cell line. Conclusion: SLSP could alleviate cognitive impairment induced by SD, which was achieved probably through suppressing the abnormal autophagy and apoptosis of hippocampal neurons. The findings may contribute to the clinical application of SLSP in the prevention or therapy of neurological disorders associated with SD.

• Journal of Yeungnam Medical Science
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• v.9 no.1
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• pp.149-155
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• 1992

55 consecutive anatrophic nephrolithotomies on 53 patients performed between July, 1983 and June, 1990 were reviewed. The patients(36 male and 19 female) ranged in age from 3 to 72years. The operation time averaged 219.8 minutes with a range of 120-330 minutes, and the ischemic time ranged between 20 and 90 minutes, with a mean of 43.5 minutes. Postoperative complications developed in 18 patients, which were such as persistent urinary tract infection in 5cases(9.4%), atelectasis in 4(7.5%), transient urine leak in 2(3.8%), delayed bleeding in 2(3.8%) and urinary retention in 2(3.8%), Postoperative residual stones were identified in 15(27.3%), but in 8 of these 15patients stones were delivered spontaneously and thus 48 of 55 cases(87.3%) became stone free, The recurrence of stone was noted in 2 out of 48 patients during the short followup period. Anatrophic nephrolithotomy seems to be an effective method compared to other procedure because of decreasing recurrence of stone by complete stone removal and reconstruction of abnormal collecting system.