• Clinical and Experimental Pediatrics
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• v.59 no.9
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• pp.374-380
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• 2016

Purpose: Patients with unresectable, relapsed, or refractory osteosarcoma need a novel therapeutic agent. Metformin is a biguanide derivative used in the treatment of type II diabetes, and is recently gaining attention in cancer research. Methods: We evaluated the effect of metformin against human osteosarcoma. Four osteosarcoma cell lines (KHOS/NP, HOS, MG-63, U-2 OS) were treated with metformin and cell proliferation was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell cycle progression and apoptosis were evaluated using flow cytometric analysis, and migration and wound healing assay were performed. Fourteen female Balb/c-nude mice received KHOS/NP cell grafts in their thigh, and were allowed access to metformin containing water (2 mg/mL) ad libitum. Tumor volume was measured every 3-4 days for a period of 4 weeks. Results: Metformin had a significant antiproliferative effect on human osteosarcoma cells. In particular, metformin inhibited the proliferation and migration of KHOS/NP cells by activation of AMP-activated protein kinase and consequent inhibition of the mammalian target of rapamycin pathway. It also inhibited the proliferation of cisplatin-resistant KHOS/NP clone cells. Analysis of KHOS/NP xenograft Balb/c-nude models indicated that metformin displayed potent in vivo antitumor effects. Conclusion: Further studies are necessary to explore metformin's therapeutic potential and the possibilities for its use as an adjuvant agent for osteosarcoma.

• Journal of The Korean Society of Clinical Toxicology
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• v.3 no.2
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• pp.86-92
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• 2005

Purpose: The main cause of death due to acute organophosphate (OP) poisoning is believed acute respiratory failure caused by cholinergic reactions. Recently, advances in respiratory and intensive care make it possible to maintain the respiratory function of patients with OP poisoning, but the mortality rates remain high. The present study clarified the hemodynamics of patients with acute lethal OP poisoning. The purpose of this study was to analyse the outcomes and predictors of mortality in patients with acute OP poisoning requiring intensive care. Methods: We reviewed medical and intensive care records of patients with acute OP poisoning admitted to emergency department and ICU between March 1998 and Aug 2005. We collected patient information regarding poisoning, clinical, and demographic features. Results: During the study period, 67 subjects treated with intensive care and ventilator management in addition to gastric decontamination standard therapy with atropine and 2-PAM. Of 67 patients, 13 died. Kaplan-Meier survival analysis demonstrated a steep decline in the cumulative survival to $86.6\%$ during the first week. Mean arterial pressure < 60 mmHg within the first 24 hours was recognized as a poor prognostic indicators among mechanical ventilated patients. Conclusion: Most OP poisoning-related deaths occurred within the first week of poisoning. Mean arterial pressure lower than 60 mmHg might be the best predictor of poor outcome. We speculated that the refractory hypotension is the leading cause of death in patients with lethal OP poisoning that receiving mechanical ventilation and maximal supportive care.

• Annals of Clinical Neurophysiology
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• v.14 no.2
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• pp.64-71
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• 2012

Background: It is generally accepted that upper motor neuron (UMN) lesion can alter lower motor neuron (LMN) function by the plasticity of neural circuit. However there have been only few researches regarding the axonal excitability of LMN after UMN injury especially during the acute stage. The aim of this study was to investigate the nerve excitability properties of the LMNs following an acute to subacute supratentorial corticospinal tract lesion. Methods: An automated nerve excitability test (NET) using the threshold tracking technique was utilized to measure multiple excitability indices in median motor axons of 15 stroke patients and 20 controls. Testing of both paretic and non-paretic side was repeated twice, during the acute stage and subacute stage. The protocols calculated the strength-duration time constant from the duration-charge curve, parameters of threshold electrotonus (TE), the current-threshold relationship from sequential sub-threshold current, and the recovery cycle from sequential supra-threshold stimulation. Results: On the paretic side, compared with the control group, significant decline of superexcitablity and increase in the relative refractory period were observed during the subacute stage of stroke. Additionally, despite the absence of statistical significance, a mildly collapsing in ('fanning in') of the TE was found. Conclusions: Our results suggest that supratentorial brain lesions can affect peripheral axonal excitability even during the early stage. The NET pattern probably suggests background membrane depolarization of LMNs. These features could be associated with trans-synaptic regulation of UMNs to LMNs as one of the "neural plasticity" mechanisms in acute brain injury.

• Journal of Environmental Science International
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• v.16 no.6
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• pp.671-675
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• 2007

The objective of this study was to clarify the characteristics of the removed micropollutant since the breakthrough of adsorption ability was occurred in biological activated carbon(BAC) process. The removal efficiency of DOC (Dissolved Organic Carbon) was 36 % in the breakthrough of BAC occurred by NOM (Natural Organic Matter). The most of removal DOC was found out the adsorbable and biodegradable DOC (A&BDOC). But it was not clear to remove by any mechanism because A&BDOC have simultaneously the adsorption of activated carbon and biodegradation by microorganism in BAC. The removal of bromophenol was examined with BAC and rapid sand filter, for investigation of DOC removal mechanism in the breakthrough of BAC. In this experiment, BAC filter has been operated for 20 months for the treatment of reservoir water. The BAC filter was already exhausted by NOM. Bromophenol, adsorbable and refractory matter, was completely removed by BAC filter. Therefore, it might be removed by the adsorption in BAC. Adsorption isotherms of bromophenol were compared to two BACs which was preloaded with 500 daltons and 3,000 daltons of NOM. BAC preloaded with 3,000 daltons of NOM was not decreased to the adsorbability of bromophenol but BAC preloaded with 500 daltons of NOM was greatly decreased to it. These result indicated that NOM of low molecular weight can be removed by adsorption after a long period of operation and the breakthrough by NOM in BAC. Therefore, micropollutants might be removed through adsorption by saturated BAC.

• Annals of Clinical Neurophysiology
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• v.2 no.1
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• pp.27-30
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• 2000

Reflex epilepsies are distinct but not clearly understood clinical entity. Various cerebral activities induced by simple stimulation including visual, auditory, somatosensory stimulation, as well as diverse functional tasks such as reading, calculation, complex thinking are believed to be seizure-inducing factors. We experienced two patients whose seizures were readily precipitated by complex, strenuous thinking. Both patients was teen-aged boy at the onset of seizure(13, and 15 years of age each) with normal physical and mental growth. Although first seizure was precipitated by watching TV and playing puzzles in each patient, initial diagnosis was idiopathic generalized epilepsy, possibly juvenile myoclonic epilepsy( JME). For the first few years, seizures were infrequent but mostly precipitated by the tasks needs concentration such as playing computer games, decision-making, mathematics, reading, or during the examination. EEG revealed various thinking process including reading hard books, drawing complex figure, complex calculation induced epileptic discharges even if it usually needs certain period of concentration. Phenytoin, valproic acid, clonazepam, vigabatrin, and lamotrigine sometimes abated their seizures but none of these made them seizure-free. Complex reflex epilepsy induced by thinking was proposed to be a separate type of epilepsy or a variant of JME. Age, sex, stereotypic seizure-inducing factors, clinical course, and refractory epilepsies in these patients highly suggested this type of epilepsy as a variant of JME but its refractoriness and unique provocation still needs more speculation.

• Journal of the Korean GEO-environmental Society
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• v.12 no.1
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• pp.35-40
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• 2011

Magnesia-carbon brick is used to refractory material in Converter and/or Ladle furnace for molten steel manufacturing. The rapid growth of steel making industry, molten steel industry is increased. Therefore, growth of molten steel industry lead to make waste magnesia-carbon brick by repair of Converter and/or Ladle furnace. These waste magnesia-carbon brick is abandoned all. Besides, as it is loosely composed of silt and clay including sand falling according to the type of gangue, rainwater inflows and outflows relatively easily, but silt or clay particles absorb water for a long period, weakening ground. This study tried to show that when colluvial soil is solidified using waste magnesia-carbon brick powder as a way to solidify strengthen the rigidity of colluvial soil.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.25 no.4
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• pp.283-292
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• 2022

Purpose: The prevalence of eosinophilic esophagitis (EoE) has been on the rise since it was first described in the 1990s. Several diseases and exogenous factors have been associated with EoE. Our aim was to investigate the epidemiology of EoE in cystic fibrosis (CF) patients. Methods: We identified individuals with CF from September 2014 to September 2019 within a database (IBM Explorys Solutions, Inc.). The prevalence of EoE in patients with CF was compared to the general population. Results: The database included 36,111,860 patients during the 5-year study period: 12,950 with CF (0.036%) and 28,090 with EoE (0.078%). EoE prevalence was higher in CF patients than the general population (46 in 10,000 vs. 7.8 in 10,000, p<0.001). Patients with CF and EoE were more likely to be male (50% vs. 33.5%, p<0.008), children (33.3% vs. 16.5%, p<0.001), and non-Hispanic (100% vs. 88.7%, p<0.001) than CF patients without EoE. CF with EoE patients were more likely to be children than EoE only (33.3% vs. 10.5%, p<0.001). Allergic conditions were generally more prevalent in CF with EoE than CF only (83.3% vs. 68.3%, p=0.01) and EoE only (83.3% vs. 69.3%, p=0.014). Conclusion: EoE is nearly 6-times more prevalent in CF patients. Those patients had higher incidence of other atopic conditions. EoE must be considered in the differential diagnosis of patients with CF presenting with dysphagia, refractory gastroesophageal reflux, vomiting, and other esophagus-related symptoms.

• Journal of Chest Surgery
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• v.56 no.6
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• pp.414-419
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• 2023

Background: The recurrence of ventricular arrhythmias (VAs) in patients who have already undergone treatment with antiarrhythmic medication, catheter ablation, and the insertion of implantable cardioverter defibrillators is not uncommon. Recent studies have shown that bilateral cardiac sympathetic denervation (BCSD) effectively treats VAs. However, only a limited number of studies have confirmed the safety of BCSD as a viable therapeutic option for VAs. Methods: This single-center study included 10 patients, who had a median age of 54 years (interquartile range [IQR], 45-65 years) and a median ejection fraction of 58.5% (IQR, 56.2%-60.8%), with VAs who underwent video-assisted BCSD. BCSD was executed as a single-stage surgery for 8 patients, while the remaining 2 patients initially underwent left cardiac sympathetic denervation followed by right cardiac sympathetic denervation. We evaluated postoperative complications, the duration of hospital stays, and VA-related symptoms before and after surgery. Results: The median hospital stay after surgery was 2 days (IQR, 2-3 days). The median surgical time for BCSD was 113 minutes (IQR, 104-126 minutes). No significant complications occurred during hospitalization or after discharge. During the median follow-up period of 13.5 months (IQR, 10.5-28.0 months) from surgery, no VA-related symptoms were observed in 70% of patients. Conclusion: The benefits of a short postoperative hospitalization and negligible complications make BCSD a safe, alternative therapeutic option for patients suffering from refractory VAs.

• Journal of clinical neurology
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• v.18 no.2
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• pp.207-213
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• 2022

Background and Purpose Neuromyelitis optica spectrum disorder (NMOSD) is a rare demyelinating disease of the central nervous system (CNS). We investigated the medical behaviors of experts in Korea when they are diagnosing and treating NMOSD. Methods An anonymous questionnaire on the diagnosis and treatment of NMOSD was distributed to experts in CNS demyelinating diseases. Results Most respondents used the 2015 diagnostic criteria for NMOSD and applied a cerebrospinal fluid examination, magnetic resonance imaging (MRI) of the brain and spine, and anti-aquaporin-4 antibody testing to all suspected cases of NMOSD. All respondents prescribed steroid pulse therapy as an first-line therapy in the acute phase of NMOSD, and 67% prescribed azathioprine for maintenance therapy in NMOSD. However, details regarding monitoring, the tapering period of oral steroids, second-line therapy use in refractory cases, management during pregnancy, and schedule of follow-up MRI differed according to the circumstances of individual patients. We analyzed the differences in response rates between two groups of respondents according to the annual number of NMOSD patients that they treated. The group that had been treating ≥10 NMOSD patients annually preferred rituximab more often as the second-line therapy (p=0.011) and had more experience with rituximab treatment (p=0.015) compared with the group that had been treating <10 NMOSD patients. Conclusions This study has revealed that NMOSD experts in Korea principally follow the available treatment guidelines. However, the differences in specific clinical practices applied to uncertain cases that have been revealed will need to be investigated further in order to formulate suitable recommendations.

• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.295-306
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• 2001

Objectives : The management of massive brain swelling remains an unsolved problem in neurosurgical field. Despite newly developed medical and pharmacological therapy, the mortality and morbidity due to massive brain swelling remains high. According to many recent reports, surgical decompression with dura expansion is superior to medical management in patients with massive brain swelling. We performed surgical treatment on the first line of treatment, and followed medical management in case with refractory increased intracranial pressure(ICP). To show the quantitative effect of decompressive surgery on the intracranial pressure, we performed ventricular puncture and checked the ventricular ICP continuously during the decompressive surgery and postoperative period. Materials and Methods : Fifty-one patients with massive brain swelling, undergoing bilateral decompressive craniectomy with dura expansion, were studied in this study. In all patients, ventricular puncture was performed at Kocher's point on the opposite side of massive brain swelling. The ventricular pressure was monitored continuously, during the bilateral decompression procedures and postoperative period. Results : The initial ventricular ICP were varied from 13mmHg to 112mmHg. Immediately after the bilateral craniectomy, mean ventricular ICP decreased to $53.1{\pm}15.8%$ of the initial ICP(ranges from 5mmHg to 87mmHg). Dura opening decreased mean ICP by additional 36.7% and made the ventricular pressure $16.4{\pm}10.5%$ of the initial pressure (ranges from 0mmHg to 28mmHg). Postoperatively, ventricular pressure was lowered to $20.2{\pm}22.6%$(ranged from 0mmHg to 62.3mmHg) of the initial ICP. The ventricular ICP value during the first 24 hours after decompressive surgery was found to be an important prognostic factor. If ICP was over 35mmHg, the mortality was 100% instead of additional medical(barbiturate coma therapy and hypothermia) treatments. Conclusion : Bilateral decompression with dura expansion is considered an effective therapeutic modality in ICP control. To obtain favorable clinical outcome in patients with massive brain swelling, early decision making on surgical management and proper patient selection are mandatory.