시험관내허혈환경에서과립구성장인자의인간뇌피질에서유래된신경세포주의보호효과

정근화 대한뇌졸중학회 2004 Journal of stroke Vol.6 No.1

Stroke & Neural Stem cell Laboratory in Clinical Research Institute, Department of Neurology, Seoul National University Hospital, Seoul National University, Seoul, South Korea*,Department of Neurology, Seoul National Hospital, Seoul, South Korea†Department of Neurology, Ilsan Paik Hospital, Inje University, Goyang, South Korea‡Background: Granulocyte colony-stimulating factor (G-CSF) has neuroprotective effects against experimentalfocal cerebral ischemia. However, its neuroprotective effect on human brain is unknown. In this study we attempt-ed to determine whether G-CSF can protect the neuronal cell line derived from human cortex against in vitroischemia.Methods: Human cortical-neuroblastoma hybrid cell line (A1G11) was exposed to hypoxia with glu-cose deprivation (6 hours). To test the protective effect of G-CSF, human recombinant G-CSF (0, 5, 25, 50, or 100ng/ml) was used. Cell viability or cytotoxicity was determined by MTT or LDH assay. Flow cytometry by annex-in-V and propidium iodide (PI) and immunocytochemistry by active caspase-3 antibody were performed to detectapoptotic or viable cells. Results: Morphological changes suggestive of neuronal damage were observed follow-ing ischemia. G-CSF promoted cell survival (42% vs 32%) and decreased cytotoxicity (9% vs 18%) at a maximal-ly effective concentration of 25 ng/ml. From the flow cytometric analysis, G-CSF reduced early apoptotic (annex-in V+/PI-), and late apoptotic or necrotic (annexin V+/PI+) cells. A decrease in immunoreactivity against activecaspase-3 in the G-CSF-treated group was correlated with the neuronal protection.Conclusions: Our results pro-vide evidence that G-CSF can protect human cortical hybrid neurons from apoptotic or necrotic cell death after anischemic insult.대한뇌졸중학회지제6권제1호2004년5월

심방세동과 허혈뇌졸중 또는 일과성허혈발작을 가진환자에서 최신 항혈전치료에 대한 지침

정근화,유경호,김영대,박종무,홍근식,나정호,권순억,배희준,허지회,이병철,윤병우 대한신경과학회 2016 대한신경과학회지 Vol.34 No.3

Cardioembolic stroke related to atrial fibrillation is problematic due to high recurrence, mortality, and morbidity rates. The optimal anticoagulant therapy therefore needs to be applied to prevent the occurrence of a second stroke in patients with nonvalvular atrial fibrillation. The oral anticoagulant warfarin has traditionally been used, but it is limited by its narrow efficacy window, complex pharmacokinetics, and multiple drug interactions, thus requiring frequent blood monitoring. New oral anticoagulants have recently been developed that target a specific coagulation component. Dabigatran (a direct thrombin inhibitor) and rivaroxaban, apixaban, and edoxaban (inhibitors of factor Xa) have advantages of rapid action time, short half-life, stable plasma concentration, and few drug interactions. Large randomized clinical trials and meta-analyses have recently been published on the efficacy and safety of these new oral anticoagulants. Based on the results obtained in recent clinical trials, we have revised the recommendations for selecting optimal anticoagulant therapy in patients with nonvalvular atrial fibrillation.

뇌졸중 치료 연구의 한계점과 도전: 기초 및 중개 뇌졸중 연구 최신지견

정근화 대한뇌졸중학회 2011 Journal of stroke Vol.13 No.1

Ischemia-reperfusion injury is complicated with multiple injury pathways. If a particular agent is used to restore blood flow and prevent cell death, many damaged neurons may come back to life. However, for stroke victims, there are no effective curative therapeutic approaches available other than thrombolytic treatment. The efficacy of neuroprotective agents are limited by low diffusion, narrow time window, strict dose titration, and lack of confidence at the preclinical level. NXY-059 reflects the fundamental limitation of neuroprotectant. There are recent attempts to overcome these limitations, with use of annexin A2, fingolimod, hydrogen, nitrite, and more. By covering two components, this report reviews what we have recently learned. In addition, it sheds light on some of the newer issues in clinical application. (Korean J Stroke 2011;13:11-15)

파킨슨병의 유전인자 고찰

정근화,전범석 대한신경과학회 2004 대한신경과학회지 Vol.22 No.4

Parkinson disease (PD) is a neurodegenerative disease characterized by the selective loss of dopaminergic neurons from the substantia nigra pars compacta leading to the impairment of motor functions. Recent genetic studies have uncovered several genes involved in inherited forms of the disease. These gene products are likely to be implicated in the biochemical pathways underlying the etiology of sporadic PD. Our review discusses the pathogenetic mechanisms of the mutated genes.

Circulating Endothelial Progenitor Cells in Cerebrovascular Disease

정근화,노재규 대한신경과학회 2008 Journal of Clinical Neurology Vol.4 No.4

Stroke is associated with high disability and mortality burdens worldwide, but there are few effective and widely available therapies. There is therefore a need to develop treatments that promote the repair and regeneration of ischemic brain tissue. In this regard, a population of adult stem cells-called endothelial progenitor cells (EPCs)-has been identified in peripheral blood that could provide novel approaches in regenerative medicine for curing patients with acute ischemic stroke. There is accumulating evidence that EPCs can repair damaged endothelia and attenuate the development and progression of atherosclerosis. Also, EPCs can be recruited in response to acute ischemic events and participate in reparative vasculogenesis. Most studies related to EPCs have involved patients with cardiovascular diseases, and there is emerging evidence that EPCs represent a risk marker and a potential therapeutic agent in cerebrovascular disease. Here we review the characteristics and biology of EPCs in cerebrovascular disease and discuss the challenges that must be addressed to clarify the role and therapeutic applicability of EPCs in cerebrovascular disease.

2009년 한국 뇌졸중 진료지침에서 뇌졸중 이차예방 중 두개강외 경동맥협착의 수술 또는 중재적 치료에 관한 내용의 부분 개정

정근화,유경호,권오기,박현선,홍근식,허지회,권순억,오창완,배희준,이병철,김성림,박인성,윤병우 대한뇌졸중학회 2011 Journal of stroke Vol.13 No.3

Since the publication of the fi rst edition of Korean clinical practice guidelines of secondary stroke prevention, encouraging data from recent large clinical trials and meta-analysis have led us to consider many therapeutic options in the treatment of symptomatic extracranial carotid stenosis. Accordingly, the writing group of Clinical Research Center for Stroke decided to provide recent views on the therapeutic revascularization of extracranial carotid stenosis, and timely evidence-based recommendations. In this updated version, new evidences about carotid angioplasty/stenting, treatment timing, and perioperative preparation are given, and qualifying conditions for operator are elucidated. This refi nement was based on current consensus between Korean Society of Intravascular Neurosurgery, Korean Society of Interventional Neuroradiology, and Korean Society of Cerebrovascular Surgery and approved by Korean Stroke Society, Korean Neurological Association, and Korean Society of Geriatric Neurology. These recommendations are subject to future correction based on new evidences from ongoing and future studies. (Korean J Stroke 2011;13:99-106)

펜데믹 이후 항공사 운항 및 객실승무원 피로관리와 안전관리의 정책적 변화 고찰

정근화,전제형,성화영,천수아 한국항공우주의학협회 2022 항공우주의학 학술대회 Vol.2022 No.11

Rapidly Progressive Toxic Leukoencephalomyelopathy with Myelodysplastic Syndrome: a Clinicopathological Correlation

정근화,주건,김영아,전범석 대한신경과학회 2007 Journal of Clinical Neurology Vol.3 No.1

Neurological disorders induced by long-term exposure to organic solvents typically have a slowly progressive clinical course, which may be arrested or even reversed following discontinuation of exposure. We report an unusual case of rapidly progressive toxic leukoencephalomyelopathy in a 29-year-old man who had worked at a chemical factory that used toluene for the manufacture of nylon 66 for 5 years. He presented with progressive weakness of legs, recurrent seizures, and cognitive decline. Widespread white-matter changes in the brain and spinal cord, and myelodysplastic syndrome were noted. He died 6 months after the onset of his symptoms, and autopsy showed discrete multifocal demyelination and necrosis in the central nervous system, and dysplastic cells of erythroid, myeloid, and megakaryotic lineages in blood vessels. The co-occurrence of leukoencephalomyelopathy and myelodysplastic syndrome highlights the vulnerability of the white matter and bone marrow to injury from organic solvents. Intravascular congestion of dysplastic hematopoietic cells might have led to his unusually rapid progression of leukoencephalomyelopathy.

都市化에 따른 大都市의 過大規模學校 및 過密學校의 實態와 改善方向

정근화 성균관대학교 교육대학원 1985 교육논총 Vol.1 No.1

공동현상을 고려한 펌프 인듀서 설계

정근화(Keun-Hwa Jung),안광운(Kwang-Woon Ahn),이승배(Seungbae Lee),김진화(Jin-Hwa Kim),강신형(Shin-Hyoung Kang) 한국유체기계학회 2001 유체기계 연구개발 발표회 논문집 Vol.- No.-

The cavitation causes suction performance and efficiency of the high-speed pump to be reduced significantly. To diminish these effects, the inducer has been used Most of the inducer is designed at a maximum efficiency point of the pump, therefore suction performance drop due to effects of flow separation and inlet inverse flow is often observed at off-design point. The objective of this study is to find out the cavitation modes at various conditions by applying event detection technique and to design an inducer reducing cavitation. The pressure fluctuations at each cavitating condition were measured at inducer inlet and outlet locations using pressure transducers, which were located 90 degrees apart from each other to identify the cavitation modes. The time-frequency characteristics were analyzed by using Choi-williams distribution. In the second part of this paper, the inducer design method which uses nominal performance characteristic and onset condition of cavitation is introduced and applied to real situation.