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1.  A Case of Gastritis Associated with Gastric Capillariasis 
Journal of Korean Medical Science  2009;24(5):963-966.
This report is about the case of gastritis associated with capillariasis. The patient was a 52-yr-old Korean woman who occasionally ate raw fish and chicken. She complained of mild abdominal pain and nausea, but not diarrhea. An endoscopic examination revealed an exudative flat erosive change on the gastric mucosa of the antrum. She was microscopically diagnosed as chronic gastritis with numerous eosinophil infiltrations. The sectioned worms and eggs in mucosa were morphologically regarded as belonging to the genus Capillaria. This is the first case of gastric capillariasis reported in the Republic of Korea.
PMCID: PMC2752786  PMID: 19795001
Capillaria; Stomach; Biopsy; Endoscopy
2.  Spontaneous Thrombolysis of Multiple Thrombi at Distal Region of Hypoplastic Vertebral Artery After Stent-assisted Angioplasty on Vertebral Artery Origin Stenosis: Angiographic Follow-up 
Vertebral artery hypoplasia (VAH) can be easily overlooked if the contralateral side vertebral artery is intact, because of compensation by the contralateral artery or cerebral collateral network. The clinical relevance and hemodynamic impact of VAH is still controversial. However, VAH has recently been considered a risk factor for posterior circulation ischemia. Ischemic stroke is seldom caused by free floating thrombi (FFT) in the artery. Pathophysiology of FFT has not yet been clarified. The state of reduced blood flow such as a vertebral artery origin stenosis may cause FFT. Their instability may make them sources of recurrent artery to artery embolism. Patients with FFT will require appropriate medical and endovascular treatment.
The current case illustrates a short-term angiographic change of spontaneous thrombolysis of VAH and multiple thrombi at the distal region of the stenosed lesion after stent-assisted angioplasty for a vertebral artery origin stenosis.
PMCID: PMC4205256  PMID: 25340032
Vertebral artery hypoplasia; Free floating thrombi; Endovascular treatment; Vertebral artery origin stenosis
3.  Surgical Recanalization of Distal Middle Cerebral Artery Occlusion Due to a Coil Migration During Endovascular Coil Embolization: A Case Report 
Coil migration into the parent artery during endovascular coil embolization is a rare, but life-threatening complication, which can induce thromboembolism and result in poor outcome. A 63-year-old man was referred to Chonbuk National University Hospital emergency center due to migration of a coil for a left middle cerebral artery bifurcation unruptured aneurysm. We performed an emergency craniectomy to remove the coil migrated to the distal M2 branch and thrombus, and aneurysmal neck clipping for his aneurysm. Fortunately, at the six month follow-up, the patient did not show any noticeable neurological sequela. In case of parent artery occlusion due to coil migration an immediate recanalization should be performed by a neurovascular specialist who can provide both surgical treatment and endovascular management in order to prevent severe sequela or even death.
PMCID: PMC4205257  PMID: 25340033
Endovascular coil embolization; Cerebrovascular complication; Neurosurgical procedure
4.  Rapid Progression of Symptomatic Vertebrobasilar Artery Dissection on Magnetic Resonance Imaging: A Case Report 
Neurointervention  2014;9(2):106-108.
Spontaneous intracranial vertebrobasilar dissection can manifest with various clinical symptoms, including subarachnoid hemorrhage or ischemic symptoms from impaired posterior circulation. A 29-year-old woman came to our emergency department with a sudden onset of left sided mild motor weakness and headache. Initial magnetic resonance imaging (MRI) showed mild luminal irregularities in the vertebrobasilar arteries with an eccentric periluminal hematoma. Follow-up MRI obtained 3 days later showed a progression of vertebrobasilar dissection to multifocal stenoses with an increased intramural hematoma.
PMCID: PMC4239409  PMID: 25426307
Stroke; Vertebrobasilar dissection; Magnetic resonance imaging
5.  Early expressions of hypoxia-inducible factor 1alpha and vascular endothelial growth factor increase the neuronal plasticity of activated endogenous neural stem cells after focal cerebral ischemia 
Neural Regeneration Research  2014;9(9):912-918.
Endogenous neural stem cells become “activated” after neuronal injury, but the activation sequence and fate of endogenous neural stem cells in focal cerebral ischemia model are little known. We evaluated the relationships between neural stem cells and hypoxia-inducible factor-1α and vascular endothelial growth factor expression in a photothromobotic rat stroke model using immunohistochemistry and western blot analysis. We also evaluated the chronological changes of neural stem cells by 5-bromo-2′-deoxyuridine (BrdU) incorporation. Hypoxia-inducible factor-1α expression was initially increased from 1 hour after ischemic injury, followed by vascular endothelial growth factor expression. Hypoxia-inducible factor-1α immunoreactivity was detected in the ipsilateral cortical neurons of the infarct core and peri-infarct area. Vascular endothelial growth factor immunoreactivity was detected in bilateral cortex, but ipsilateral cortex staining intensity and numbers were greater than the contralateral cortex. Vascular endothelial growth factor immunoreactive cells were easily found along the peri-infarct area 12 hours after focal cerebral ischemia. The expression of nestin increased throughout the microvasculature in the ischemic core and the peri-infarct area in all experimental rats after 24 hours of ischemic injury. Nestin immunoreactivity increased in the subventricular zone during 12 hours to 3 days, and prominently increased in the ipsilateral cortex between 3–7 days. Nestin-labeled cells showed dual differentiation with microvessels near the infarct core and reactive astrocytes in the peri-infarct area. BrdU-labeled cells were increased gradually from day 1 in the ipsilateral subventricular zone and cortex, and numerous BrdU-labeled cells were observed in the peri-infarct area and non-lesioned cortex at 3 days. BrdU-labeled cells rather than neurons, were mainly co-labeled with nestin and GFAP. Early expressions of hypoxia-inducible factor-1α and vascular endothelial growth factor after ischemia made up the microenvironment to increase the neuronal plasticity of activated endogenous neural stem cells. Moreover, neural precursor cells after large-scale cortical injury could be recruited from the cortex nearby infarct core and subventricular zone.
PMCID: PMC4146222  PMID: 25206911
nerve regeneration; brain ischemia; neural stem cell; neural precursor cell; hypoxiainducible factor 1α; vascular endothelial growth factor; microenvironment; photothrombosis; neural regeneration
6.  Generation of Cancerous Neural Stem Cells Forming Glial Tumor by Oncogenic Stimulation 
Stem cell reviews  2012;8(2):532-545.
Neural stem cells in the brain have been shown to be ‘cells of origin’ of certain brain cancers, most notably astrocytomas and medulloblastoma. In particular, in a mouse model, the targeting of genetic modifications for astrocytoma-relevant tumor suppressors to neural stem cells causes malignant astrocytoma to arise, thereby suggesting that astrocytoma is derived from neural stem cells. However, it remains to be determined whether this important finding is reproducible in humans. Herein, we generated cancerous neural stem cells by introducing a set of oncogenes to human fetal neural stem cells (hfNSCs). Serial genetic modification with v-myc for immortalization and consequent H-Ras for oncogenic stimulation with viral gene delivery proved sufficient to induce the transformation of hfNSCs. The resultant F3.Ras cells evidenced a variety of the hallmarks of brain cancer stem cells and most importantly were tumorigenic, forming brain cancers consisting of both a large number of differentiated and a very few undifferentiated populations of cells in an in vivo mouse model. On the contrary, oligodendrocytes derived from the v-myc expressing parent neural stem cells were not transformed by H-Ras, which suggests that neural stem cells may be more susceptible to cancerous transformation by a combination of oncogenes. We also determined that v-myc expressing fetal neural stem cells were defective in p53 response upon the introduction of H-Ras; this finding suggests that an insufficient p53-dependent tumor suppressive mechanism would be associated with high oncogenic susceptibility to H-Ras introduction.
PMCID: PMC4043123  PMID: 21755312
Human neural stem cells; v-myc; H-Ras; Cancerous stem cells; p53; Glial tumor
7.  Evaluation of Protein Expression in Housekeeping Genes across Multiple Tissues in Rats 
Korean Journal of Pathology  2014;48(3):193-200.
Housekeeping genes, which show constant protein expression patterns between different tissue types, are very important in molecular biological studies as an internal control for protein research.
The protein expression profiles of seven housekeeping genes (HPRT1, PPIA, GYS1, TBP, YWHAZ, GAPDH and ACTB) in various rat tissues (cerebrum, cerebellum, cardiac ventricle and atrium, psoas muscle, femoral muscle, liver, spleen, kidney, and aorta) were analyzed by Western blot and compared by coefficient of variation (CV).
HPRT1 was stably expressed (CV≤10%) in six tissues (cerebrum, cerebellum, ventricle, femoral muscle, spleen, and kidney), PPIA was stably expressed in five tissues (cerebrum, cerebellum, ventricle, spleen and kidney), YWHAZ was stably expressed in three tissues (cerebrum, cerebellum, and kidney), and GAPDH was stably expressed in four tissues (cerebrum, ventricle, psoas muscle, and kidney). In comparison, GYS1, TBP, and ACTB were found to have CV values over 10% in all tissues. Of the seven genes examined, four (HPRT1, PPIA, YWHAZ, and GAPDH) were found to be stably expressed across multiple organs, with low CV values (≤10%).
These results will provide fundamental information regarding internal controls for protein expression studies and can be used for analysis of postmortem protein degradation patterns in forensic medicine.
PMCID: PMC4087132  PMID: 25013417
Genes, essential; Proteins; Tissues; Rats; Postmortem changes
8.  A comparison study between periosteum and resorbable collagen membrane on iliac block bone graft resorption in the rabbit calvarium 
Head & Face Medicine  2014;10:15.
To compare the different resorption patterns between resorbable membrane barrier and periosteum after iliac block bone grafting radiographically and histologically.
Eighteen mature male rabbits weighing from 2.0 to 2.5 kg were used. The recipient site was the rabbit skull, and autogenous iliac bone was used as the grafting material. The harvested iliac block bones were divided in the following groups: autogenous iliac block bone with preservation of the periosteum (the periosteum group), autogenous iliac block bone covered with a resorbable collagen membrane (Biomesh®, Samyang Co, Korea) after removing the periosteum (the collagen membrane group), and autogenous iliac block bones with removal of the periosteum (the control group). In each experimental group, periosteum or resorbable collagen membrane of the donor site was fixed directed to the periosteum of the recipient site. The specimens were examined macroscopically, radiographically, histologically, and histomorphometrically at every 2, 4, and 8 weeks.
All groups presented excellent bone graft healing state without inflammation, dehiscence, or displacement. The radiolucency increased from mild to moderate in all groups over the experiment. The mean thickness of the upper end of the cortical iliac bone graft was statistically significantly different between the control group and the periosteum group, between the four-week and eight-week control group, and between the four- week and eight-week periosteum group (p & 0.05).
This study suggests that both the periosteum and the resorbable collagen membrane may help to prevent soft tissue infiltration into the bone graft and to reduce bone graft resorption compared to block graft alone.
PMCID: PMC4024311  PMID: 24886656
9.  Adaptive Preheating Duration Control for Low-Power Ambient Air Quality Sensor Networks 
Sensors (Basel, Switzerland)  2014;14(3):5536-5551.
Ceramic gas sensors used for measuring ambient air quality have features suitable for practical applications such as healthcare and air quality management, but have a major drawback—large power consumption to preheat the sensor for accurate measurements. In this paper; the adaptive preheating duration control (APC) method is proposed to reduce the power consumption of ambient air quality sensor networks. APC reduces the duration of unnecessary preheating, thereby alleviating power consumption. Furthermore, the APC can allow systems to meet user requirements such as accuracy and periodicity factor when detecting the concentration of a target gas. A performance evaluation of the power consumption of gas sensors is conducted with various user requirements and factors that affect the preheating duration of the gas sensor. This shows that the power consumption of the APC is lower than that of continuous power supply methods and constant power supply/cutoff methods.
PMCID: PMC4004006  PMID: 24658619
air quality sensor networks; ceramic gas sensors; preheating duration; low power consumption
10.  Her4-Positive Population in the Tectum Opticum Is Proliferating Neural Precursors in the Adult Zebrafish Brain 
Molecules and Cells  2012;33(6):627-632.
Previous studies have shown that Notch signaling not only regulates the number of early differentiating neurons, but also maintains proliferating neural precursors in the neural tube. Although it is well known that Notch signaling is closely related to the differentiation of adult neural stem cells, none of transgenic zebrafish provides a tool to figure out the relationship between Notch signaling and the differentiation of neural precursors. The goal of this study was to characterize Her4-positive cells by comparing the expression of a fluorescent Her4 reporter in Tg[her4-dRFP] animals with a GFAP reporter in Tg[gfap-GFP] adult zebrafish. BrdU incorporation indicated that dRFP-positive cells were proliferating and a double labeling assay revealed that a significant fraction of the Her4-dRFP positive population was also GFAP-GFP positive. Our observations suggest that a reporter line with Notch-dependent gene expression can provide a tool to examine proliferating neural precursors and/or neuronal/glial precursors in the development of the adult nervous system to examine the model in which Notch signaling maintains proliferating neural precursors in the neural tube.
PMCID: PMC3887756  PMID: 22570150
adult brain; GFAP; Her4; neural precursor; Notch; transgenic zebrafish
11.  Pattern Recognition for Selective Odor Detection with Gas Sensor Arrays 
Sensors (Basel, Switzerland)  2012;12(12):16262-16273.
This paper presents a new pattern recognition approach for enhancing the selectivity of gas sensor arrays for clustering intelligent odor detection. The aim of this approach was to accurately classify an odor using pattern recognition in order to enhance the selectivity of gas sensor arrays. This was achieved using an odor monitoring system with a newly developed neural-genetic classification algorithm (NGCA). The system shows the enhancement in the sensitivity of the detected gas. Experiments showed that the proposed NGCA delivered better performance than the previous genetic algorithm (GA) and artificial neural networks (ANN) methods. We also used PCA for data visualization. Our proposed system can enhance the reproducibility, reliability, and selectivity of odor sensor output, so it is expected to be applicable to diverse environmental problems including air pollution, and monitor the air quality of clean-air required buildings such as a kindergartens and hospitals.
PMCID: PMC3571782  PMID: 23443378
gas sensor array; odor monitoring; pattern recognition; artificial neural networks (ANN); genetic algorithm (GA); neural-genetic classification algorithm (NGCA)
12.  Tcf3 Function Is Required for the Inhibition of Oligodendroglial Fate Specification in the Spinal Cord of Zebrafish Embryos 
Molecules and Cells  2011;32(4):383-388.
The generation of various subtypes of neurons and glial cells at the right time and place is crucial for the proper development of the vertebrate CNS. Although the mechanisms and factors for the regulation of neuronal diversity in the CNS have been well studied, the mechanisms regulating the sequential production of neuronal and glial cells from neural precursors remain poorly understood. This study shows that Tcf3, a member of the Lef/Tcf family of proteins, is required to inhibit the premature oligodendroglial fate specification of spinal cord precursors using the transgenic zebrafish, which expresses a dominant repressor form of Tcf3 under the control of a heat-shock inducible promoter. In addition, the data revealed that Tcf3 function in oligodendroglial fate specification is mediated independently of canonical Wnt signaling. Altogether, these results show a novel function for Tcf3 in regulating the timing of oligodendroglial fate specification in the spinal cord.
PMCID: PMC3887649  PMID: 21904879
neurogenesis; oligodendrocytes; spinal cord; Tcf3; zebrafish
13.  Tcf7l1 is required for spinal cord progenitor maintenance 
Neural progenitor cells must be maintained during development in order to produce the full complement of neuronal and glial derivatives. While molecular pathways have been identified that inhibit progenitor differentiation, it is unclear whether the progenitor state itself is actively maintained. In this study we have investigated the role of Tcf7l1 (formerly named Tcf3) in maintaining spinal progenitor characteristics and allowing the continued production of neurons and glia following primary neurogenesis. We find that spinal cord progenitor markers are progressively lost in embryos lacking Tcf7l1, and that the number of proliferative progenitors decreases accordingly. Furthermore, we show that the production of both neuronal and glial secondary derivatives of the pMN progenitor pool requires Tcf7l1. Together, these results indicate that Tcf7l1 plays an important role in spinal cord progenitor maintenance, indicating that this core function is conserved throughout multiple epithelial cell populations.
PMCID: PMC3177105  PMID: 21932308
zebrafish; Tcf7l1; spinal cord; neurogenesis
14.  Expression of the stem cell markers CD133 and nestin in pancreatic ductal adenocarcinoma and clinical relevance 
Background: To evaluate the prognostic implication of cancer stem cell markers in pancreac ductal adenocarcinoma (PDAC), the expression of CD133 and nestin were investigated in a series of PDAC patients in relation to the survival rate. Methods: This series included 42 cases of PDAC patients and evaluated the stem cell markers CD133 and nestin expression detected by immunohistochemistry. The presence of immunopositive tumor cells considering intensity and area was evaluated and interpreted in comparison to the patients’ clinicopathological and survival data. Results: Twenty eight cases (66.7%) showed high CD133 expression. The CD133 expression was mainly identified in the apical border of the tumor cell, but aberrant expression in the cytoplasmic or perinuclear location was also noted. High nestin expression in tumor cells were found in only 2 cases, but high nestin expression along perinuerial or stromal region was found in 15 cases (35.7%). There was no correlation between CD133, nestin expression and gemcitabine resistance. Statistically significant difference was found in patient survival in N stage (p=0.007), and CD133 expression (p= 0.014) in univariate analysis. Nestin expression wan not statistically significant, but it was helpful to identify the perineurial invasion. In Cox-regression hazard model stratified by age and sex for multivariable analysis, AJCC stage and CD133 were independent prognostic factors for overall survival. Conclusions: CD133 expression is upregulated in PDAC that is related to poor prognosis, and treatment targeted the CD133 positive cancer/cancer stem cells might be a promising therapeutic strategy for this patients.
PMCID: PMC3466976  PMID: 23071857
Pancreatic ductal adenocarcinoma; cancer stem cell; CD133; nestin; prognosis
15.  Multiple Gamma Knife Radiosurgery for Multiple Metachronous Brain Metastases Associated with Lung Cancer : Survival Time 
We compared the survival time between patients with multiple gamma knife radiosurgery (GKRS) and patients with a single GKRS plus whole brain radiation therapy (WBRT), in patients with multiple metachronous brain metastases from lung cancer.
From May 2006 to July 2010, we analyzed 31 patients out of 112 patients who showed multiple metachronous brain metastases. 20 out of 31 patients underwent multiple GKRS (group A) and 11 patients underwent a single GKRS plus WBRT (group B). We compared the survival time between group A and B. Kaplan-Meier method and Cox proportional hazards were used to analyze relationship between survival and 1) the number of lesions in each patient, 2) the average volume of lesions in each patient, 3) the number of repeated GKRS, and 4) the interval of development of new lesions, respectively.
Median survival time was 18 months (range 6-50 months) in group A and 6 months (range 3-18 months) in group B. Only the average volume of individual lesion (over 10 cc) was negatively related with survival time according to Kaplan-Meier method. Cox-proportional hazard ratio of each variable was 1.1559 for the number of lesions, 1.0005 for the average volume of lesions, 0.0894 for the numbers of repeated GKRS, and 0.5970 for the interval of development of new lesions.
This study showed extended survival time in group A compared with group B. Our result supports that multiple GKRS is of value in extending the survival time in patients with multiple metachronous brain metastases, and that the number of the lesions and the frequency of development of new lesions are not an obstacle in treating patients with GKRS.
PMCID: PMC3488641  PMID: 23133721
Survival time; Gamma knife radiosurgery; Whole brain radiation therapy; Metastases; Lung cancer
16.  Rapid Clinical Course of Cerebral Metastatic Angiosarcoma from the Heart 
We report here one case of rapid and aggressive course of cerebral metastatic angiosarcoma from the heart. A 36-year-old man presented with 10-days history of headache. Magnetic resonance imaging demonstrated subacute hemorrhage with a small region of enhancement in right parietal region and the pathological diagnosis was angiosarcoma. Transthoracic echocardiography demonstrated 3.2×3 cm sized mass on right atrial wall. Newly developed lesion was reoperated, three and four weeks later respectively, and whole brain radiotherapy of total 30 Gy was done. With the interval of two months, gamma knife surgery was done for new lesions two times, which were well controlled. Newly developed lesions rapidly happened even in the adjuvant treatment. He died 9 months after the diagnosis because of the aggravation of primary cancer. The cerebral metastatic angiosarcoma from the heart showed the rapid aggressive behavior and the closed follow-up could be needed for the adjuvant treatment.
PMCID: PMC3291707  PMID: 22396844
Angiosarcoma; Cerebral; Heart; Metastasis
17.  Meat and Fish Freshness Inspection System Based on Odor Sensing 
Sensors (Basel, Switzerland)  2012;12(11):15542-15557.
We propose a method for building a simple electronic nose based on commercially available sensors used to sniff in the market and identify spoiled/contaminated meat stocked for sale in butcher shops. Using a metal oxide semiconductor-based electronic nose, we measured the smell signature from two of the most common meat foods (beef and fish) stored at room temperature. Food samples were divided into two groups: fresh beef with decayed fish and fresh fish with decayed beef. The prime objective was to identify the decayed item using the developed electronic nose. Additionally, we tested the electronic nose using three pattern classification algorithms (artificial neural network, support vector machine and k-nearest neighbor), and compared them based on accuracy, sensitivity, and specificity. The results demonstrate that the k-nearest neighbor algorithm has the highest accuracy.
PMCID: PMC3522975  PMID: 23202222
electronic nose; machine olfaction; pattern classification
18.  Sequencing and characterization of Varicella-Zoster virus vaccine strain SuduVax 
Virology Journal  2011;8:547.
Varicella-zoster virus (VZV) causes chickenpox in children and shingles in older people. Currently, live attenuated vaccines based on the Oka strain are available worldwide. In Korea, an attenuated VZV vaccine has been developed from a Korean isolate and has been commercially available since 1994. Despite this long history of use, the mechanism for the attenuation of the vaccine strain is still elusive. We attempted to understand the molecular basis of attenuation mechanism by full genome sequencing and comparative genomic analyses of the Korean vaccine strain SuduVax.
SuduVax was found to contain a genome that was 124,759 bp and possessed 74 open reading frames (ORFs). SuduVax was genetically most close to Oka strains and these Korean-Japanese strains formed a strong clade in phylogenetic trees. SuduVax, similar to the Oka vaccine strains, underwent T- > C substitution at the stop codon of ORF0, resulting in a read-through mutation to code for an extended form of ORF0 protein. SuduVax also shared certain deletion and insertion mutations in ORFs 17, 29, 56 and 60 with Oka vaccine strains and some clinical strains.
The Korean VZV vaccine strain SuduVax is genetically similar to the Oka vaccine strains. Further comparative genomic and bioinformatics analyses will help to elucidate the molecular basis of the attenuation of the VZV vaccine strains.
PMCID: PMC3265557  PMID: 22176950
Varicella-zoster virus; SuduVax; Genome; Phylogeny
19.  Time Point Expression of Apoptosis Regulatory Proteins in a Photochemically-Induced Focal Cerebral Ischemic Rat Brain 
Chonnam Medical Journal  2011;47(3):144-149.
Apoptosis after global or focal cerebral ischemia plays a crucial role in mediating cell death. In this study, we observed the time point expression of physiologic events involving apoptosis regulatory proteins after photochemically-induced focal cerebral ischemia in Sprague-Dawley rats. Protein expression was evaluated at days 1, 3, and 7 by Western blot. Bcl-2, Bax, caspase-3, and phosphorylated Akt (pAkt) activity markedly increased in the ischemic hemisphere in a time-dependent manner, not affected. The expression of Bcl-2, Bax, and caspase-3 was dramatically changed around day 3, whereas changes in pAkt expression occurred at day 1. Differential elevation of these apoptosis regulatory proteins at various time points indicates that different modes of cell death occur in photochemically-induced focal cerebral ischemia in a rat brain.
PMCID: PMC3252501  PMID: 22247913
Brain ischemia; Apoptosis; Rose bengal
20.  Stem Cell Dynamics in an Experimental Model of Stroke 
Chonnam Medical Journal  2011;47(2):90-98.
We investigated the migration of endogenous neural stem cells (NSCs) toward an infarct lesion in a photo-thrombotic stroke model. The lesions produced by using rose bengal dye (20 mg/kg) with cold light in the motor cortex of Sprague-Dawley rats were also evaluated with sequential magnetic resonance imaging (MRI) from 30 minutes through 8 weeks. Migration of NSCs was identified by immunohistochemistry for nestin monoclonal antibody in the lesion cortex, subventricular zone (SVZ), and corpus callosum (CC). The contrast to noncontrast ratio (CNR) on MRI was greatest at 12 hours in DWI and decreased over time. By contrast, T1-weighted and T2-weighted images showed a constant CNR from the beginning through 8 weeks. MRI of the lesional cortex correlated with histopathologic findings, which could be divided into three stages: acute (edema and necrosis) within 24 hours, subacute (acute and chronic inflammatory cell infiltration) at 2 to 7 days, and chronic (gliofibrosis) at 2 to 4 weeks. The volume of the infarct was significantly reduced by reparative gliofibrosis. The number of nestin+ NSCs in the contralateral SVZ was similar to that of the ipsilateral SVZ in each group. However, the number of nestin+ NSCs in the ipsilateral cortex and CC increased at 12 hours to 3 days compared with the contralateral side (p<0.01) and was reduced significantly by 7 days (p<0.01). Active emigration of internal NSCs from the SVZ toward the infarct lesion may also contribute to decreased volume of the infarct lesion, but the self-repair mechanism by endogenous NSCs is insufficient to treat stroke causing extensive neuronal death. Further studies should be focused on amplification technologies of NSCs to enhance the collection of endogenous or transplanted NSCs for the treatment of stroke.
PMCID: PMC3214868  PMID: 22111067
Stroke; MRI; Neural stem cell; Dynamics
21.  A Rare Case of Spontaneous True Aneurysm of the Occipital Artery 
A 51-year-old man presented with a pulsatile scalp mass over the right occipital region, which had increased in size over the previous 1 month. He had no previous history of head trauma. Three-dimensional computed tomography (3D-CT) angiography of the brain revealed a 3.0 × 1.5 cm occipital artery aneurysm arising from the occipital artery. The occipital artery aneurysm was removed following the ligation of the proximal and distal portion of the occipital artery aneurysm. The histological diagnosis was true aneurysm. To the best of our knowledge, this is the first reported case in the literature.
PMCID: PMC2864828  PMID: 20461176
True aneurysm; Occipital artery; Three-dimensional computed tomography angiography
22.  Neurotoxicity Screening in a Multipotent Neural Stem Cell Line Established from the Mouse Brain 
Journal of Korean Medical Science  2010;25(3):440-448.
Neural stem cells (NSCs) have mainly been applied to neurodegeneration in some medically intractable neurologic diseases. In this study, we established a novel NSC line and investigated the cytotoxic responses of NSCs to exogenous neurotoxicants, glutamates and reactive oxygen species (ROS). A multipotent NSC line, B2A1 cells, was established from long-term primary cultures of oligodendrocyte-enriched cells from an adult BALB/c mouse brain. B2A1 cells could be differentiated into neuronal, astrocytic and oligodendroglial lineages. The cells also expressed genotypic mRNA messages for both neural progenitor cells and differentiated neuronoglial cells. B2A1 cells treated with hydrogen peroxide and L-buthionine-(S,R)-sulfoximine underwent 30-40% cell death, while B2A1 cells treated with glutamate and kainate showed 25-35% cell death. Cytopathologic changes consisting of swollen cell bodies, loss of cytoplasmic processes, and nuclear chromatin disintegration, developed after exposure to both ROS and excitotoxic chemicals. These results suggest that B2A1 cells may be useful in the study of NSC biology and may constitute an effective neurotoxicity screening system for ROS and excitotoxic chemicals.
PMCID: PMC2826742  PMID: 20191045
Growth Factors; Brain; Nestin; Stem Cells; Culture
23.  Tcf3 inhibits spinal cord neurogenesis by regulating sox4a expression 
Development (Cambridge, England)  2009;136(5):781-789.
The Lef/Tcf factor Tcf3 is expressed throughout the developing vertebrate central nervous system (CNS), but its function and transcriptional targets are uncharacterized. Tcf3 is thought to mediate canonical Wnt signaling, which functions in CNS patterning, proliferation, and neurogenesis. In this study, we examine Tcf3 function in the zebrafish spinal cord, and find that this factor does not play a general role in patterning, but is required for the proper expression of Dbx genes in intermediate progenitors. In addition, we show that Tcf3 is required to inhibit premature neurogenesis in spinal progenitors by repressing sox4a, a known mediator of spinal neurogenesis. Both of these functions are mediated by Tcf3 independently from canonical Wnt signaling. Together, our data indicate a novel mechanism for the regulation of neurogenesis by Tcf3-mediated repression.
PMCID: PMC2685945  PMID: 19176587
zebrafish; Tcf3; spinal progenitors; Wnt
24.  Mobility of Intradural Extramedullary Schwannoma at Spine : Report of Three Cases with Literature Review 
Although very rare, a few cases of intradural extramedullary (IDEM) spinal tumor migration have been reported since Tomimatsu first reported a mobile schwannoma of the cervical cord in 1974. Schwannoma is a neurogenic tumor which originates from nerve sheath that it is relatively well-marginated tumor with little attachment or adhesion to surrounding tissue. Mobility of tumor in spinal canal sometimes can result in negative exploration at the expected area. We found three interesting cases in which different tumor locations observed in repeated magnetic resonance image (MRI) findings. All tumors were intradural and extramedullary schwannoma. We reviewed the literature about moving tumor in the spine through PUBMED search.
PMCID: PMC2817519  PMID: 20157382
Intradural extramedullary; Schwannoma; Mobility
25.  A Mouse Model of Photochemically Induced Spinal Cord Injury 
A mouse model of spinal cord injury (SCI) could further increase our basic understanding of the mechanisms involved in injury and repair of the nervous system. The purpose of this study was to investigate whether methods used to produce and evaluate photochemical graded ischemic SCI in rats, could be successfully adapted to mice, in a reliable and reproducible manner.
Thirty female imprinting control region mice (weighting 25-30 g, 8 weeks of age) were used in this study. Following intraperitoneal injection of Rose bengal, the translucent dorsal surface of the T8-T9 vertebral laminae of the mice were illuminated with a fiber optic bundle of a cold light source. The mice were divided into three groups; Group 1 (20 mg/kg Rose bengal, 5 minutes illumination), Group 2 (20 mg/kg Rose bengal, 10 minutes illumination), and Group 3 (40 mg/kg Rose bengal, 10 minutes illumination). The locomotor function, according to the Basso-Beattie-Bresnahan scale, was assessed at three days after the injury and then once per week for four weeks. The animals were sacrificed at 28 days after the injury, and the histopathology of the lesions was assessed.
The mice in group 1 had no hindlimb movement until seven days after the injury. Most mice had later recovery with movement in more than two joints at 28 days after injury. There was limited recovery of one joint, with only slight movement, for the mice in groups 2 and 3. The histopathology showed that the mice in group 1 had a cystic cavity involving the dorsal and partial involvement of the dorsolateral funiculi. A larger cavity, involving the dorsal, dorsolateral funiculi and the gray matter of the dorsal and ventral horns was found in group 2. In group 3, most of the spinal cord was destroyed and only a thin rim of tissue remained.
The results of this study show that the photochemical graded ischemic SCI model, described in rats, can be successfully adapted to mice, in a reliable and reproducible manner. The functional deficits are correlated an increase in the irradiation time and, therefore, to the severity of the injury. The photothrombotic model of SCI, in mice with 20 mg/kg Rose bengal for 5 minutes illumination, provides an effective model that could be used in future research. This photochemical model can be used for investigating secondary responses associated with traumatic SCI.
PMCID: PMC2796355  PMID: 20041059
Photochemical; Spinal cord Injury; Mouse

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