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Featured researches published by Koang Hum Bak.


Surgical Neurology | 2000

Expression of tenascin-C in astrocytic tumors: its relevance to proliferation and angiogenesis

Choong Hyun Kim; Koang Hum Bak; Young Soo Kim; Jae Min Kim; Yong Ko; Suck Jun Oh; Kwang Mung Kim; Eun Kyung Hong

BACKGROUND The expression and distribution of the extracellular matrix protein tenascin-C (TN-C) may be enhanced in human astrocytomas. The purpose of this study is to evaluate the expression of TN-C according to histological malignancy of tumor cells and its relevance to neoplastic angiogenesis in human astrocytic tumors. METHODS Between 1994 and 1998, 52 astrocytic tumor specimens including 4 pilocytic astrocytomas, 13 astrocytomas, 3 anaplastic astrocytomas, and 32 glioblastomas were used in this study. A retrospective analysis was performed to evaluate a statistical correlation between TN-C expression and proliferative indices. We characterized the expression of TN-C in neoplastic vessels, around individual tumor cells as a tumor network, and in tumor cells by immunohistochemistry using antibodies against human TN-C. The proliferative indices were also investigated by immunostaining with the MIB-1 antibody against the Ki-67 proliferation antigen. RESULTS TN-C immunoreactivity was found to be enhanced in tumor vessels and tumor networks of high-grade astrocytic tumors. The vascular TN-C deposition was greater in high-grade than in low-grade astrocytic tumors (p < 0.05). Its expression was the most intense in glioblastomas. Proliferation indices increased with tumor grade and MIB-1 labeling index (LI) was highest in glioblastomas. Moreover, expression of TN-C in tumor vessels was correlated with proliferative indices. CONCLUSIONS Our data show that TN-C in human astrocytic tumors may be identified as a factor contributing to malignant progression. And also, enhanced expression of TN-C in tumor vessels having a high proliferative index indicates that TN-C could be involved in neoplastic angiogenesis.


Clinical Neurology and Neurosurgery | 1999

Symptomatic sacral extradural arachnoid cyst associated with lumbar intradural arachnoid cyst

Choong Hyun Kim; Koang Hum Bak; Jae Min Kim; Nam Kyu Kim

A case of sacral extradural arachnoid cyst associated with lumbar intradural arachnoid cyst in a 35-year-old male is reported. The patient presented with a history of severe sacrococcygeal pain, constipation, and dysuria for several months. Computed tomographic (CT) myelograms and magnetic resonance imaging (MRI) scans showed a huge sacral cyst without neural components. A favorable outcome could be achieved by decompression of the cyst, obliteration of the fistulous channel between the cyst and the thecal sac, and fenestration of the arachnoid cyst into the subarachnoid space. The relevant literatures are also reviewed.


Journal of Clinical Neuroscience | 2008

Aneurysmal subarachnoid hemorrhage in young adults: A gender comparison study

Sang Kyu Park; Jae Min Kim; Jae Hoon Kim; Jin Hwan Cheong; Koang Hum Bak; Choong Hyun Kim

Aneurysmal subarachnoid hemorrhage is uncommon in young adults. The aim of this study was to compare clinical characteristics of ruptured aneurysms between males and females in the third or fourth decade of life. We retrospectively investigated 301 patients who underwent surgery for ruptured cerebral aneurysms over 6 years. Among them, 53 patients were aged between 20-39 years. Clinical characteristics and related variables were compared between genders. In general, there was a favorable outcome in either gender (84.9%). There was a higher incidence of multiplicity and intraoperative rupture in females, as well as a significant difference in aneurysm location between genders (p=0.030, p=0.014, and p=0.027 respectively). Overall outcome was not different between the two groups. These results suggest that aneurysm formation may differ between genders.


Scientific Reports | 2015

Prognostic role of copeptin after stroke: A systematic review and meta-analysis of observational studies

Kyu Sun Choi; Hyun Jung Kim; Hyoung Joon Chun; Jae Min Kim; Hyeong Joong Yi; Jin Hwan Cheong; Choong Hyun Kim; Suck Jun Oh; Ko Y; Young Soo Kim; Koang Hum Bak; Je Il Ryu; Wonhee Kim; Taeho Lim; Hyeong Sik Ahn; Il Min Ahn; Seon Heui Lee

Copeptin, the C-terminal part of provasopressin, has emerged as a novel prognostic marker after hemorrhagic or ischemic stroke. The aim of this study was to quantitatively assess the prognostic significance of plasma copeptin level on functional outcome and mortality in patients with acute stroke using a meta-analysis of the available evidence. Thirteen relevant studies from 2,746 patients were finally included in our study. An elevated plasma copeptin level was associated with an increased risk of unfavorable outcome and mortality after stroke (OR 1.77; 95% CI, 1.44–2.19 and OR 3.90; 95% CI 3.07–4.95, respectively). The result of the pooled measure on standardized mean difference (SMD) was that plasma copeptin levels were found to be significantly higher in patients who died compared to survivors (SMD 1.70; 95% CI, 1.36–2.03). A stratified analysis by study region showed significant differences in SMD of copeptin, and the heterogeneity among studies was significantly decreased. However, the positive association of copeptin with poor prognosis after stroke was consistent in each stratified analysis. The present meta-analysis suggests that early measurement of plasma copeptin could provide better prognostic information about functional outcome and mortality in patients with acute stroke.


Journal of Korean Neurosurgical Society | 2012

Posterior Interspinous Fusion Device for One-Level Fusion in Degenerative Lumbar Spine Disease : Comparison with Pedicle Screw Fixation - Preliminary Report of at Least One Year Follow Up

Ho Jung Kim; Koang Hum Bak; Hyoung Joon Chun; Suck Jun Oh; Tae Hoon Kang; Moon Sool Yang

Objective Transpedicular screw fixation has some disadvantages such as postoperative back pain through wide muscle dissection, long operative time, and cephalad adjacent segmental degeneration (ASD). The purposes of this study are investigation and comparison of radiological and clinical results between interspinous fusion device (IFD) and pedicle screw. Methods From Jan. 2008 to Aug. 2009, 40 patients underwent spinal fusion with IFD combined with posterior lumbar interbody fusion (PLIF). In same study period, 36 patients underwent spinal fusion with pedicle screw fixation as control group. Dynamic lateral radiographs, visual analogue scale (VAS), and Korean version of the Oswestry disability index (K-ODI) scores were evaluated in both groups. Results The lumbar spine diseases in the IFD group were as followings; spinal stenosis in 26, degenerative spondylolisthesis in 12, and intervertebral disc herniation in 2. The mean follow up period was 14.24 months (range; 12 to 22 months) in the IFD group and 18.3 months (range; 12 to 28 months) in pedicle screw group. The mean VAS scores was preoperatively 7.16±2.1 and 8.03±2.3 in the IFD and pedicle screw groups, respectively, and improved postoperatively to 1.3±2.9 and 1.2±3.2 in 1-year follow ups (p<0.05). The K-ODI was decreased significantly in an equal amount in both groups one year postoperatively (p<0.05). The statistics revealed a higher incidence of ASD in pedicle screw group than the IFD group (p=0.029). Conclusion Posterior IFD has several advantages over the pedicle screw fixation in terms of skin incision, muscle dissection and short operative time and less intraoperative estimated blood loss. The IFD with PLIF may be a favorable technique to replace the pedicle screw fixation in selective case.


Journal of Korean Medical Science | 2006

Influence of lamina terminalis fenestration on the occurrence of the shunt-dependent hydrocephalus in anterior communicating artery aneurysmal subarachnoid hemorrhage.

Jae Min Kim; Ji Young Jeon; Jae Hoon Kim; Jin Hwan Cheong; Koang Hum Bak; Choong Hyun Kim; Hyeong Joong Yi; Kwang Myung Kim

Recently, it was reported that fenestration of the lamina terminalis (LT) may reduce the incidence of shunt-dependent hydrocephalus in aneurysmal subarachnoid hemorrhage (SAH). The authors investigated the efficacy of the LT opening on the incidence of shunt-dependent hydrocephalus in the ruptured anterior communicating artery (ACoA) aneurysms. The data of 71-ruptured ACoA aneurysm patients who underwent aneurysmal clipping in acute stage were reviewed retrospectively. Group I (n=36) included the patients with microsurgical fenestration of LT during surgery, Group II (n=35) consisted of patients in whom fenestration of LT was not feasible. The rate of shunt-dependent hydrocephalus was compared between two groups by logistic regression to control for confounding factors. Ventriculo-peritoneal shunts were performed after aneurysmal obliteration in 18 patients (25.4%). The conversion rates from acute hydrocephalus on admission to chronic hydrocephalus in each group were 29.6% (Group I) and 58.8% (Group II), respectively. However, there was no significant correlation between the microsurgical fenestration and the rate of occurrence of shunt-dependent hydrocephalus (p>0.05). Surgeons should carefully decide the concomitant use of LT fenestration during surgery for the ruptured ACoA aneurysms because of the microsurgical fenestration of LT can play a negative role in reducing the incidence of chronic hydrocephalus.


Journal of Korean Neurosurgical Society | 2012

Perioperative Risk Factors Related to Lumbar Spine Fusion Surgery in Korean Geriatric Patients

Jung Hyun Lee; Hyoung-Joon Chun; Hyeong-Joong Yi; Koang Hum Bak; Ko Y; Yoon Kyoung Lee

Objective Life expectancy for humans has increased dramatically and with this there has been a considerable increase in the number of patients suffering from lumbar spine disease. Symptomatic lumbar spinal disease should be treated, even in the elderly, and surgical procedures such as fusion surgery are needed for moderate to severe lumbar spinal disease. However, various perioperative complications are associated with fusion surgery. The aim of this study was to examine perioperative complications and assess risk factors associated with lumbar spinal fusion, focusing on geriatric patients at least 70 years of age in the Republic of Korea. Methods We retrospectively investigated 489 patients with various lumbar spinal diseases who underwent lumbar spinal fusion surgery between 2003 and 2007 at our institution. Three fusion procedures and the number of fused segments were analyzed in this study. Chronic diseases were also evaluated. Risk factors for complications and their association with age were analyzed. Results In this study, 74 patients experienced complications (15%). The rate of perioperative complications was significantly higher in patients 70 years of age or older than in other age groups (univariate analysis, p=0.001; multivariate analysis, p=0.004). However, perioperative complications were not significantly associated with the other factors tested (sex, comorbidities, operation procedures, fusion segments involved). Conclusion Increasing age was an important risk factor for perioperative complications in patients undergoing lumbar spinal fusion surgery whereas other factors were not significant. We recommend good clinical judgment and careful selection of geriatric patients undergoing lumbar spinal fusion surgery.


Journal of Korean Neurosurgical Society | 2011

Targeting a Safe Entry Point for C2 Pedicle Screw Fixation in Patients with Atlantoaxial Instability

Hyoung-Joon Chun; Koang Hum Bak

OBJECTIVE This investigation was conducted to evaluate a new, safe entry point for the C2 pedicle screw, determined using the anatomical landmarks of the C2 lateral mass, the lamina, and the isthmus of the pars interarticularis. METHODS Fifteen patients underwent bilateral C1 lateral mass-C2 pedicle screw fixation, combined with posterior wiring. The C2 pedicle screw was inserted at the entry point determined using the following method : 4 mm lateral to and 4 mm inferior to the transitional point (from the superior end line of the lamina to the isthmus of the pars interarticularis). After a small hole was made with a high-speed drill, the taper was inserted with a 30 degree convergence in the cephalad direction. Other surgical procedures were performed according to Harms description. Preoperatively, careful evaluation was performed with a cervical X-ray for C1-C2 alignment, magnetic resonance imaging for spinal cord and ligamentous structures, and a contrast-enhanced 3-dimensional computed tomogram (3-D CT) for bony anatomy and the course of the vertebral artery. A 3-D CT was checked postoperatively to evaluate screw placement. RESULTS Bone fusion was achieved in all 15 patients (100%) without screw violation into the spinal canal, vertebral artery injury, or hardware failure. Occipital neuralgia developed in one patient, but this subsided after a C2 ganglion block. CONCLUSION C2 transpedicular screw fixation can be easily and safely performed using the entry point of the present study. However, careful preoperative radiographic evaluation, regardless of methods, is mandatory.


Journal of Neuro-oncology | 2006

Congenital supratentorial hemangioblastoma as an unusual cause of simultaneous supra- and infratentorial intracranial hemorrhage: case report

Jae Min Kim; Jin Hwan Cheong; Koang Hum Bak; Choong Hyun Kim; Dong Woo Park; Young Ha Oh

SummaryCongenital supratentorial hemangioblastomas are extremely rare tumors even in pediatric population. A 57-day-old female neonate presented with a pure motor seizure. On imaging studies, intracranial hemorrhagic lesions containing multiple cystic components in the cerebral and cerebellar areas were revealed, simultaneously. After the emergency surgical evacuation only to a fatal supratentorial lesion, an infratentorial lesion also regressed spontaneously. The authors report a case of full-term neonate presenting with supra- and infratentorial hemorrhagic lesions, which occurred as a result of congenital supratentorial hemangioblastoma bleeding.


Korean Journal of Neurotrauma | 2014

The Predicting Factors for Recurrence of Chronic Subdural Hematoma Treated with Burr Hole and Drainage

Dae Hyo Song; Young Soo Kim; Hyoung Joon Chun; Hyeong Joong Yi; Koang Hum Bak; Ko Y; Suck Jun Oh

Objective Chronic subdural hematoma (CSDH) is common in elderly patients. So, with an increasing number of elderly people in the general population, there is a need to investigate risk factors which increase recurrence rate. In this study, factors affecting the postoperative recurrence are investigated based on the reoperative CSDH cases. Methods Total of ninety-seven patients was enrolled in this study who had have operation for CSDH. In all patients, one burr hole trephination and drainage was the method of choice for the initial treatment of CSDH. We retrospectively evaluated several factors which affect to recurrence of CSDH. Results Retrospective analysis was performed in 97 patients. Sixteen patients experienced reoperation within 3 months (16/97, 16.5%) for recurrence of CSDH. And, when hematoma was divided by internal architecture, heterogeneous density group seems to be have close relationship with recurrence more significantly than homogeneous density group (p=0.002). Hypertension, diabetes mellitus, early removal of drainage tube, bilaterality of hematoma also have significant relationship with recurrence. Conclusion Recurrence rate of CSDH treated with one burr hole drainage is related with some various factors. There was statistically significant difference between recurred group and non-recurred group. Not only demographic factors but also internal architecture on preoperative brain computed tomography is a significant predicting factor of recurrence in CSDH patients who underwent a surgery. In this study, heterogeneous type hematoma have significantly related with recurrence of CSDH. We should give attention to these predicting factors for more effective care.

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Kim Jm

University of Ulsan

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