• Bulletin of the Korean Chemical Society
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• v.29 no.7
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• pp.1386-1390
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• 2008

Artemisinin, the effective ingredient of Chinese herb Artemisia annua L (Qinghao in Chinese), has been proved to be effective to antimalarial. Herein, a reliable, sensitive and convenient electrochemical method was developed for the determination of artemisinin utilizing the excellent properties of multi-wall carbon nanotube (MWNT). The electrochemical behavior of artemisinin was investigated. It is found that the reduction peak current of artemisinin remarkably increases and the peak potential shifts positively by 240 mV at the MWNT film-modified electrode. These phenomena indicate that the MWNT film exhibits efficient catalytic activity to the electrochemical reduction of artemisinin. The effects of pH value, amount of MWNT, scan rate and accumulation time were examined. The limit of detection (S/N = 3) is as low as 10 $\mu$ g $L^{-1}$. Finally, this newly developed method was used to determine the content of artemisinin in Artemisia annua L.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5427-5433
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• 2013

5-Azacytidine (5-azaC) was originally identified as an anticancer drug (NSC102876) which can cause hypomethylation of tumor suppressor genes. To assess its effects on runt-related transcription factor 3 (RUNX3), expression levels and the promoter methylation status of the RUNX3 gene were assessed. We also investigated alteration of biologic behavior of esophageal carcinoma TE-1 cells. MTT assays showed 5-azaC inhibited the proliferation of TE-1 cells in a time and dose-dependent way. Although other genes could be demethylated after 5-azaC intervention, we focused on RUNX3 gene in this study. The expression level of RUNX3 mRNA increased significantly in TE-1 cells after treatment with 5-azaC at hypotoxic levels. RT-PCR showed 5-azaC at $50{\mu}M$ had the highest RUNX3-induction activity. Methylation-specific PCR indicated that 5-azaC induced RUNX3 expression through demethylation. Migration and invasion of TE-1 cells were inhibited by 5-azaC, along with growth of Eca109 xenografts in nude mice. In conclusion, we demonstrate that the RUNX3 gene can be reactivated by the demethylation reagent 5-azaC, which inhibits the proliferation, migration and invasion of esophageal carcinoma TE-1 cells.

• Fibers and Polymers
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• v.2 no.2
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• pp.51-57
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• 2001

Tissue engineering is one exciting approach to treat patients who need a new organ or tissue. A critical element in this approach is the polymer scaffold, as it provides a space for new tissue formation and mimics many roles of natural extra-cellular matrices. In this review, we describe several design parameters of polymer matrices that can significantly affect cellular behavior, as well as various polymers which are frequently used to date or potentially useful in many tissue engineering applications. Interactions between cells and polymer scaffolds, including specific receptor-ligand interactions, physical and degradation feature of the scaffolds, and delivery of soluble factors, should be considered in the design and tailoring of appropriate polymer matrices to be used in tissue engineering applications, as these interactions control the function and structure of engineered tissues.

• The Korean Journal of Cytopathology
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• v.8 no.1
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• pp.62-68
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• 1997

Acinic cell carcinoma is a slow-growing solid neoplasm of salivary gland. Although their cytological and histological finding is bland-looking, their biological behavior is unpredictable. We experienced two cases of acinic cell carcinoma of the salivary gland diagnosed by fine needle aspiration biopsy and confirmed by tissue examination. They showed different clinical courses. We compared their cytologic and histologic findings. The first case was a right preauricular mass in a 58 year-old female of 3 years duration. The cytologic smear revealed sheets or small clusters of monotonous cells mimicking normal serous acinar cells with little cellular pleomorphism. She underwent superficial parotid lobectomy. The tumor was a well demarcated 1.5cm sized nodular mass without infiltration into surrounding parenchyme. The second case was a left submandibular mass in a 23 year-old male of 4 years duration. The smear showed more severe pleomorphism of the tumor cells than those of previous case. Excisional biopsy was done. The excised tumor was $5.5{\times}3.5{\times}3cm$ sized multilobulated solid mass with invasion into surrounding parenchyme. The tumor recurred after 20months, thus total excision of the mass and modified radical neck dissection was carried out. From the above findings, cytologic atypism, infiltrative growth pattern and type of initial therapy may be correlated with biologic behavior.

• Korean Journal of Head & Neck Oncology
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• v.17 no.2
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• pp.210-215
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• 2001

Objectives: Salivary gland neoplasms are a diverse group of benign and malignant tumors with a wide range of biologic behaviors. The surgeon must understand the pathologic behavior of each tumor type to develop an appropriate treatment plan. The authors planned this study to evaluate our clinical experiences and establish a new treatment strategy. Materials and Methods: From Sep. 1997 to June 2001, 25 cases of major salivary gland tumors which were underwent surgery were evaluated retrospectively. Results: 20 cases were benign and 5 were malignant. Most(17) of benign cases were pleomorphic adenoma and they showed wide distribution in age. Also we experienced other benign such as warthin's tumor, oncocytoma. In malignant, there were 2 cases of carcinoma ex-pleomorphic adenoma, 2 cases of adenoid cystic carcinoma, and one lymphoma. In carcinoma ex-pleomorphic adenoma, one showed dismal prognosis in spite of multimodality and the other were recurrent to be salvaged. Conclusion: We concluded that salivary gland neoplasms are challenging because of their relative infrequency, inconsistent classification, and highly variable biologic behavior. We need to establish new effective strategies with the regard of factors influencing survival.

• Journal of Gastric Cancer
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• v.9 no.3
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• pp.71-77
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• 2009

Endoscopic resection is one of the curative options for early gastric cancer. However, based on large-scale data about the risk of lymph node metastasis in early gastric cancer, endoscopic resection has been attempted for the following: differentiated intramucosal gastric cancer, regardless of size and without ulcers; differentiated intramucosal cancer, 30 mm in size with ulcers; minute submucosal differentiated cancer <30 mm in size; and undifferentiated intramucosal cancer, <20 mm in diameter without venous or lymphatic involvement. However, undifferentiated early gastric cancer exhibits different biologic behavior from differentiated early gastric cancer. Thus, the application of endoscopic resection for undifferentiated early gastric cancer remains controversial. In this review, we discuss the application of endoscopic resection for undifferentiated early gastric cancer based on analysis of biologic behavior and data of endoscopic resection.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.85-85
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• 1993

The clinical staging system for laryngeal cancers is not sufficient for prognosticator due to different biologic characteristics and their microenvironment according to primary sites. For determining the prognosticators, the authors peformed immunohistochemical staining to EGFR, p53 protein, and pRB in 40 cases of surgically treated squamous cell carcinomas of larynx in our institute during the past 5 years. The results are as followings; 1. The positive expression rate of p53 protein and negative expression rate of pRB showed correlations with clinical parameters. 2. The three-year survival rate for p53 protein positive cases was worse than the p53 protein negative cases. 3. Expression rate of EGFR was not correlated with the clinical parameters. As a conclusion, expression rates of p53 protein and pRB not only reflect well the biologic behavior of laryngeal cancer, but correlate closely with the tumor factors. Therefore they may be useful as the prognosticator to predict the malignant potency of laryngeal squamous cell carcinomas.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.6
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• pp.751-763
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• 2005

Statement of problem. To improve a direct implant fixation to the bone, various strategies have been developed focusing on the surface of materials. The surface quality of the implant depends on the chemical, physical, mechanical and topographical properties of the surface. The different properties will interact with each other and a change in thickness of the oxide layer may also result in a change in surface energy, the surface topography and surface, chemical composition. However, there is limited the comprehensive study with regard to changed surface and biologic behavior of osteoblast by anodization. Purpose of study. The aim of this study was to analyze the characteristics of an oxide layer formed and to evaluate the cellular biologic behaviors on titanium by anodic oxidation (anodization) by cellular proliferation, differentiation, ECM formation and gene expression. And the phospholipase activity was measured on the anodized surface as preliminary study to understand how surface properties of Ti implant are transduced into downstream cellular events. Methods and Materials. The surface of a commercially pure titanium(Grade 2) was modified by anodic oxidation. The group 1 samples had a machined surface and other three experimental specimens were anodized under a constant voltage of 270 V(Group 2), 350 V(Group 3), and 450 V(Group 4). The specimen characteristics were inspected using the following five categories; the surface morphology, the surface roughness, the thickness of oxide layer, the crystallinity, and the chemical composition of the oxide layer. Cell numbers were taken as a marker for cell proliferation. While the expression of alkaline phosphatase and Runx2 (Cbfa1) was used as early differentiation marker for osteoblast. The type I collagen production was determined, which constitutes the main structural protein of the extracellular matrix. Phospholipase $A_2$ and D activity were detected. Results. (1) The anodized titanium had a porous oxide layer, and there was increase in both the size and number of pores with increasing anodizing voltage. (2) With increasing voltage, the surface roughness and thickness of the oxide film increased significantly (p<0.01), the $TiO_2$phase changed from anatase to rutile. During the anodic oxidization, Ca and P ions were more incorporated into the oxide layer. (3) The in vitro cell responses of the specimen were also dependant on the oxidation conditions. With increasing voltage, the ALP activity, type I collagen production, and Cbfa 1 gene expression increased significantly (p<0.01), while the cell proliferation decreased. (4) In preliminary study on the relation of surface property and phospholipase, PLD activity was increased but $PLA_2$ activity did not changed according to applied voltage. Conclusion. The anodized titanium shows improved surface characteristics than the machined titanium. The surface properties acquired by anodization appear to give rise more mature osteoblast characteristics and might result in increased bone growth, and contribute to the achievement of a tight fixation. The precise mechanism of surface property signaling is not known, may be related to phospholipase D.

• Korean Journal of Biological Psychiatry
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• v.20 no.4
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• pp.129-135
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• 2013

Aggression can be defined as 'behavior intended to harm another' which can be seen both from humans and animals. However, trying to understand aggression in a simplistic view may make it difficult to develop an integrated approach. So, we tried to explain aggression in a multidisciplinary approach, affected by various factors such as neuroanatomical structures, neurotransmitter, genes, and sex hormone. Parallel with animal models, human aggression can be understood with two phenomena, offensive aggression and defensive aggression. Neurobiological model of aggression give a chance to explain aggression with an imbalance between prefrontal regulatory influences and hyper-reactivity of the subcortical areas involved in affective evaluation, finally in an aspect of brain organization. Serotonin and GABA usually inhibit aggression and norepinephrine while glutamate and dopamine precipitate aggressive behavior. As there is no one gene which has been identified as a cause of aggression, functions between gene to gene interaction and gene to environment interaction are being magnified. Contributions of sex hormone to aggression, especially molecular biologic interaction of testosterone and regulation of estrogen receptor have been emphasized during the research on aggression. This multidisciplinary approach on aggression with types, neurochemical bases, and animal models can bring integrated interpretation on aggression.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.1
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• pp.121-126
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• 1990

Primary squamous cell carcinoma occuring in the salivary glands involves a grave prognosis since the tumor exhibit infiltrative properties, metastasizes early and recurs readily. But it is so rare that the clinician may see only a few in a lifetime of practice. The following report describes a case of primary squamous cell carcinoma arising from the submaxillary gland treated by combined therapy including surgery, radiotherapy and hyperthermia. The biologic behavior of the tumor was quite abnormal that immediate recurrence was noticed in two weeks after surgery. The progress was dismal and the disease became overwhelming before long.