• 대한핵의학회지
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• 제29권1호
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• pp.105-109
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• 1995

Tyrosine의 유도체인 [$^{123}I$]IMT를 각종 악성종양의 SPECT에 이용하기 위하여 표지시 반응조건과 뇌종양이식 백서에서의 체내 동태를 연구하여 다음과 같은 결과를 얻었다. AMT의 [$^{123}I$] 표지에 chloramine-T 보다 Iodobead를 이용하는 것이 훨씬 간편하고 수율이 높았으며, Iodobead 1개, AMT $200{\mu}g/100{\mu}L$ phosphate buffer, PH 5.5, 상온에서 7분간 반응시키는 것이 최적 반응조건이었다. 9L glioma 이식 백서 체내동태는 [$^{123}I$]IMT가 신장으로 배설됨과 체내에서 탈요오드 반응이 일어남이 추측되었고, 정상조직의 3배 방사능 섭취가 관찰되어, 각종 뇌종양의 진단 및 치료 후 경과 관찰에 이용 가능성이 보여 임상연구의 진행이 기대된다.

• 한국멀티미디어학회논문지
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• 제25권8호
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• pp.1233-1241
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• 2022

Tumors of the brain are the deadliest, with a life expectancy of only a few years for those with the most advanced forms. Diagnosing a brain tumor is critical to developing a treatment plan to help patients with the disease live longer. A misdiagnosis of brain tumors will lead to incorrect medical treatment, decreasing a patient's chance of survival. Radiologists classify brain tumors via biopsy, which takes a long time. As a result, the doctor will need an automatic classification system to identify brain tumors. Image classification is one application of the deep learning method in computer vision. One of the deep learning's most powerful algorithms is the convolutional neural network (CNN). This paper will introduce a novel deep learning structure and image gradient to classify brain tumors. Meningioma, glioma, and pituitary tumors are the three most popular forms of brain cancer represented in the Figshare dataset, which contains 3,064 T1-weighted brain images from 233 patients. According to the numerical results, our method is more accurate than other approaches.

• Journal of Korean Neurosurgical Society
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• 제63권5호
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• pp.566-578
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• 2020

Objective : Radiation is known to induce autophagy in malignant glioma cells whether it is cytocidal or cytoprotective. Dexamethasone is frequently used to reduce tumor-associated brain edema, especially during radiation therapy. The purpose of the study was to determine whether and how dexamethasone affects autophagy in irradiated malignant glioma cells and to identify possible intervening molecular pathways. Methods : We prepared p53 mutant U373 and LN229 glioma cell lines, which varied by phosphatase and tensin homolog (PTEN) mutational status and were used to make U373 stable transfected cells expressing GFP-LC3 protein. After performing cell survival assay after irradiation, the IC₅₀ radiation dose was determined. Dexamethasone dose (10 μM) was determined from the literature and added to the glioma cells 24 hours before the irradiation. The effect of adding dexamethasone was evaluated by cell survival assay or clonogenic assay and cell cycle analysis. Measurement of autophagy was visualized by western blot of LC3-I/LC3-II and quantified by the GFP-LC3 punctuated pattern under fluorescence microscopy and acridine orange staining for acidic vesicle organelles by flow cytometry. Results : Dexamethasone increased cell survival in both U373 and LN229 cells after irradiation. It interfered with autophagy after irradiation differently depending on the PTEN mutational status : the autophagy decreased in U373 (PTEN-mutated) cells but increased in LN229 (PTEN wild-type) cells. Inhibition of protein kinase B (AKT) phosphorylation after irradiation by LY294002 reversed the dexamethasone-induced decrease of autophagy and cell death in U373 cells but provoked no effect on both autophagy and cell survival in LN229 cells. After ATG5 knockdown, radiation-induced autophagy decreased and the effect of dexamethasone also diminished in both cell lines. The diminished autophagy resulted in a partial reversal of dexamethasone protection from cell death after irradiation in U373 cells; however, no significant change was observed in surviving fraction LN229 cells. Conclusion : Dexamethasone increased cell survival in p53 mutated malignant glioma cells and increased autophagy in PTEN-mutant malignant glioma cell but not in PTEN-wildtype cell. The difference of autophagy response could be mediated though the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin signaling pathway.

• International Journal of Computer Science & Network Security
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• 제22권4호
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• pp.101-110
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• 2022

Histopathological analysis of biopsy specimens is still used for diagnosis and classifying the brain tumors today. The available procedures are intrusive, time consuming, and inclined to human error. To overcome these disadvantages, need of implementing a fully automated deep learning-based model to classify brain tumor into multiple classes. The proposed CNN model with an accuracy of 92.98 % for categorizing tumors into five classes such as normal tumor, glioma tumor, meningioma tumor, pituitary tumor, and metastatic tumor. Using the grid search optimization approach, all of the critical hyper parameters of suggested CNN framework were instantly assigned. Alex Net, Inception v3, Res Net -50, VGG -16, and Google - Net are all examples of cutting-edge CNN models that are compared to the suggested CNN model. Using huge, publicly available clinical datasets, satisfactory classification results were produced. Physicians and radiologists can use the suggested CNN model to confirm their first screening for brain tumor Multi-classification.

• Journal of the Optical Society of Korea
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• 제20권2호
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• pp.305-313
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• 2016

A number of fluorescence imaging techniques for use in the surgical removal of glioma have been developed over the course of the long history of neurosurgery. Various biomarkers, biochemical agents, and detection systems for glioma have also been developed. This review focuses on 5-aminolevulinic acid (5-ALA), which is used to detect glioma. Numerous forms of fluorescence-guided surgery use 5-ALA, which is helpful to the surgeon. The surgical microscope system is the observational method generally used with 5-ALA, while the loupe, endoscope, and exoscope are simpler alternatives. A system is needed for minimal resection and other issues that arise during neurosurgery. Such an enhanced system should be able to detect low-grade tumors and provide information on microinvasive diseases, resulting in an improved survival rate and better surgical skills. Development of systems that fulfill certain needs would help protect the brain function of the patient and broaden the use of such systems in neurosurgery.

• BMB Reports
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• 제44권7호
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• pp.452-457
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• 2011

The Egr-1 is an immediate early response gene encoding a transcription factor that functions in the regulation of cell growth, differentiation, and apoptosis. Estrogen has diverse physiological effects, including cellular proliferation and neuroprotection against brain injury. There are two types of estrogen receptors (ERs), $ER{\alpha}$ and $ER{\beta}$. $ER{\alpha}$-induced Egr-1 expression has been extensively studied; however, the role of $ER{\beta}$ is yet not known. In the present study, we investigated whether or not $ER{\beta}$ induces Egr-1 expression in C6 rat glioma cells, which express $ER{\beta}$ but not $ER{\alpha}$. Our results show that $ER{\beta}$ promoted up-regulation of Egr-1 expression via a non-genomic mechanism involving the Raf/MEK1/Erk/Elk-1 signaling cascade.

• Journal of Yeungnam Medical Science
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• 제8권2호
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• pp.63-69
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• 1991

신경교종에서 핵소체 조성부를 측정하기 위해 18예의 인체 신경교종을 대상으로 은교질염색을 시행하였다. 그 결과 정상뇌의 성상세포는 $1.17{\pm}0.07$의 핵소체 조성부수를 보였고 성상세포종의 핵소체 조성부수는 $1.53{\pm}0.25$, 악성 성상세포종은 $2.37{\pm}0.71$, 다형성 신경교아종은 $2.88{\pm}0.41$이었으며 각 군들간에 유의한 차이를 보였다. 그래서 은교질 염색법에 의한 핵소체 조성부의 측정은 환자에게 부담을 주지 않는 비교적 간단하고 빠른 방법으로 신경교종의 증식능을 판정하는데 어느정도 도움이 될 것으로 생각한다.

• Molecules and Cells
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• 제37권1호
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• pp.17-23
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• 2014

We already had reported that Bcl-w promotes invasion or migration in gastric cancer cells and glioblastoma multiforme (GBM) by activating matrix metalloproteinase-2 (MMP-2) via specificity protein 1 (Sp1) or ${\beta}$-cateinin, respectively. High expression of Bcl-w also has been reported in GBM which is the most common malignant brain tumor and exhibits aggressive and invasive behavior. These reports propose that Bcl-w-induced signaling is strongly associated with aggressive characteristic of GBM. We demonstrated that Sp1 protein or mRNA expression is induced by Bcl-w using Western blotting or RT-PCR, respectively, and markedly elevated in high-grade glioma specimens compared with low-grade glioma tissues using tissue array. However, relationship between Bcl-w-related signaling and aggressive characteristic of GBM is poorly characterized. This study suggested that Bcl-w-induced Sp1 activation promoted expression of glioma stem-like cell markers, such as Musashi, Nanog, Oct4 and sox-2, as well as neurosphere formation and invasiveness, using western blotting, neurosphere formation assay, or invasion assay, culminating in their aggressive behavior. Therefore, Bcl-w-induced Sp1 activation is proposed as a putative marker for aggressiveness of GBM.

• Journal of Korean Neurosurgical Society
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• 제66권5호
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• pp.562-572
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• 2023

Objective : Bevacizumab is a feasible option for treating cerebral radiation necrosis (RN). We investigated the clinical outcome of RN after treatment with bevacizumab and factors related to the initial response and the sustained effect. Methods : Clinical data of 45 patients treated for symptomatic RN between September 2019 and February 2021 were retrospectively collected. Bevacizumab (7.5 mg/kg) was administered at 3-week intervals with a maximum four-cycle schedule. Changes in the lesions magnetic resonance image (MRI) scans were examined for the response evaluation. The subgroup analysis was performed based on the initial response and the long-term maintenance of the effect. Results : Of the 45 patients, 36 patients (80.0%) showed an initial response, and eight patients (17.8%) showed delayed worsening of the corresponding lesion. The non-responders showed a significantly higher incidence of diffusion restriction on MRI than the responders (100.0% vs. 25.0%, p<0.001). The delayed worsening group showed a significantly higher proportion of glioma pathology than the maintenance group (87.5% vs. 28.6%, p=0.005). Cumulative survival rates with sustained effect were significantly higher in the groups with non-glioma pathology (p=0.019) and the absence of diffusion restriction (p<0.001). Pathology of glioma and diffusion restriction in MRI were the independent risk factors for non-response or delayed worsening after initial response. Conclusion : The initial response of RN to bevacizumab was favorable, with improvement in four-fifths of the patients. However, a certain proportion of patients showed non-responsiveness or delayed exacerbations. Bevacizumab may be more effective in treating RN in patients with non-glioma pathology and without diffusion restriction in the MRI.

• Journal of Korean Neurosurgical Society
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• 제40권3호
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• pp.154-158
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• 2006

Objective : We treated 10 pediatric diffuse intrinsic brain stem glioma[BSG] patients with Novalis system [linac based radiotherapy unit, Germany] and examined the efficacy of the Fractionated Stereotactic Radiotherapy[FSRT]. Methods : A retrospective review was conducted on 10 pediatric diffuse intrinsic BSG patients who were treated with FSRT between May, 2001 and August, 2004. The mean age of the patient group was 7.7 years old. Male to female ratio was 4 to 1. The mean dose of FSRT was 38.7Gy, mean fractionated dose was 2.6Gy, mean fractionation size was 16.6, and target volume was $42.78cm^3$. The mean follow up period was 14 months. Results : Four weeks after completion of FSRT, improvements on neurological status and Karnofsky performance scale[KPS] score were recorded in 9/10 (90%] patients and magnetic resonance imaging[MRI] showed decrease in target tumor volume in 8 pediatric patients. The median survival period was 13.5 months after FSRT and treatment toxicity was mild. Conclusion : It is difficult for surgeons to choose surgical treatment for diffuse intrinsic BSG due to its dangerous anatomical structures. FSRT made it possible to control the tumor volume to improve neurological symptoms with minimal complications. We expect that FSRT is a feasible treatment modality for pediatric diffuse intrinsic BSG with tolerable toxicities.