• Proceedings of the Korean Society of Toxicology Conference
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• 2006.11a
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• pp.55-64
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• 2006

The fetal central nervous system (CNS) is sensitive to diverse environmental factors, such as alcohol, heavy metals, irradiation, mycotoxins, neurotransmitters, and DNA damage, because a large number of processes occur during an extended period of development. Fetal neural damage is an important issue affecting the completion of normal CNS development. As many concepts about the brain development have been recently revealed, it is necessary to compare the mechanism of developmental abnormalities induced by extrinsic factors with the normal brain development. To clarify the mechanism of fetal CNS damage, we used one experimental model in which 5-azacytidine (5AZC), a DNA damaging and demethylating agent, was injected to the dams of rodents to damage the fetal brain. 5AzC induced cell death (apoptosis)and cell cycle arrest in the fetal brain, and it lead to microencephaly in the neonatal brain. We investigated the mechanism of apoptosis and cell cycle arrest in the neural progenitor cells in detail, and demonstrated that various cell cycle regulators were changed in response to DNA damage. p53, the guardian of genome, played a main role in these processes. Further, using DNA microarray analysis, tile signal cascades of cell cycle regulation were clearly shown. Our results indicate that neural progenitor cells have the potential to repair the DNA damages via cell cyclearrest and to exclude highly affected cells through the apoptotic process. If the stimulus and subsequent DNA damage are high, brain development proceeds abnormally and results in malformation in the neonatal brain. Although the mechanisms of fetal brain injury and features of brain malformation afterbirth have been well studied, the process between those stages is largely unknown. We hypothesized that the fetal CNS has the ability to repair itself post-injuring, and investigated the repair process after 5AZC-induced damage. Wefound that the damages were repaired by 60 h after the treatment and developmental processes continued. During the repair process, amoeboid microglial cells infiltrated in the brain tissue, some of which ingested apoptotic cells. The expressions of genes categorized to glial cells, inflammation, extracellular matrix, glycolysis, and neurogenesis were upregulated in the DNA microarray analysis. We show here that the developing brain has a capacity to repair the damage induced by the extrinsic stresses, including changing the expression of numerous genes and the induction of microglia to aid the repair process.

• Journal of Gastric Cancer
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• v.3 no.2
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• pp.75-79
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• 2003

Purpose: Evidence exists that dysregulation of apoptosis is involved in the pathogenesis of cancer development. The Bcl-$x_{L}$/Bcl-2-associated death promoter (BAD), a member of the Bcl-2 family, is a critical regulatory component of the intrinsic cell-death pathway that exerts its pro-apoptotic effect upon heterodimerization with anti-apoptotic proteins Bcl-2 and Bcl-$X_{L}$. Expression of the BAD protein has been reported in several cancer types, but not in stomach cancer. The aim of this study was to explore the expression status of the BAD protein in gastric carcinomas. Materials and Methods: In the current study, we analyzed the expression of the BAD protein in 60 advanced gastric adenocarcinomas by using immunohistochemistry and a tissue microarray approach. Results: Immunopositivity (defined as $\geq\30\%$) was observed for the BAD protein in 57 ($95\%$) of the 60 cancers. Normal gastric mucosal cells showed weaker expressions of the BAD protein than gastric carcinomas. Conclusion: Taken together, these results suggest that stomach cancer cells in vivo may need BAD protein expression for apoptosis. Also, the higher expression of the BAD protein in stomach cancer cells than in normal gastric mucosal cells suggests that apoptosis might be easily triggered in susceptible stomach cancer cells, thereby producing selective pressure to make more apoptosis-resistant cells during tumor development.

• The Journal of Korean Medicine
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• v.31 no.1
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• pp.30-46
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• 2010

Objectives: This study was performed to investigate the anti-obesity effects of Gambi-bang 4 (GBB4) on obesity-induced mice. Methods: C57BL/6 mice were divided into four groups (normal, high fat diet with control, high fat diet with Reductil, high fat diet with GBB4 extract) and fed for 8 weeks. We observed body weight change, the weight change of the adipocytes in body, total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides, serum leptin level, expression of ${\beta}3AR$ and leptin genes in 3T3-L1 adipocytes and adipose tissue, and histological changes of adipose tissue and liver cells. Results: 1. Compared with the control group, the GBB4 group was significantly lower in body weight, weight of adipocytes, and amount of glucose. 2. The GBB4 group was significantly lower in the amount of total cholesterol, LDL-cholesterol and triglycerides, and HDL-cholesterol compared with the control. 3. Compared with the control group, the GBB4 group was significantly lower in the amount of serum leptin. 4. The GBB4 group was significantly higher in the revelation of ${\beta}3AR$ and leptin in 3T3-L1 adipocytes and primary adipose cells compared with the control. 5. Compared with the control group, the GBB4 group was smaller in the size of adipocytes in adipose tissue and the adipose vacuoles in liver tissue were decreased. Conclusions: These results suggested that GBB4 has inhibitory effects on obesity. GBB4 might be applied in treatment of obesity, so further studies analyzing its effects are needed.

• Development and Reproduction
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• v.15 no.1
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• pp.1-7
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• 2011

It is suggested that FGF/Ras/MEK/Erk signaling plays crucial roles in specification and cell division of the mesodermal precursor cells in ascidian embryos. To investigate how the number of cell division in tissue precursor cells is determined, we have characterized Wee1 homolog, Hr-Wee1 of the ascidian Halocynthia roretzi. We found that the Hr-Wee1 mRNA is expressed both maternally and zygotically. Maternal transcript is localized to the cytoplasm in the animal cells, while zygotic expression is seen in cells of the endoderm lineage from 32-cell to 110-cell stages. Zygotic in situ signal is detected in the A-line neural plate cells of neurulae, and in epidermal cells of the head region of tailbud embryos. Embryos treated with MEK signaling inhibitor showed a similar pattern to normal embryos in expression of Hr-Wee1. Therefore, it is likely that MEK signaling does not affect the maternal and zygotic expression of Hr-Wee1.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4707-4712
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• 2012

Annexin A1 is a 37-kDa calcium- and phospholipid-binding protein of the annexin superfamily considered to play an important role in tumorigenesis. However, associations with clinicopathological features in pancreatic ductal adenocarcinoma (PDAC) cases have yet to be fully defined. We therefore investigated the prognostic value of annexin A1 protein as a PDAC biomarker in 83 tumor and matched non-cancerous tissues or normal pancreas tissues. Expression was analyzed using real-time RT-PCR, Western blotting and immunohistochemistry. In non-tumor tissue, myoepithelial cells showed no or weak expression of annexin A1 while expression was strong and sometimes even located in the nuclei of endothelial cells in tumor tissue. High expression was significantly associated with advanced stage (P <0.05) and a worse overall survival (P <0.05). These results provide new insights to better understand the role of annexin A1 in PDAC survival, and might be relevant to prediction of prognosis and development of more effective therapeutic strategies aimed at improving survival.

• Journal of Korean Medicine Rehabilitation
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• v.28 no.3
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• pp.1-11
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• 2018

Objectives This study was designed to evaluate the efficacy of Seungyangjeseup-tang on obesity by using 3T3-L1 cells and high fat diet mice. Methods In vitro, Seungyangjeseup-tang extract (SYJST) (10, 50, 100, 200, 400, $800{\mu}g/mL$) ware added in 3T3-L1 cells. SYJST cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assasy. Adipocyte differentiation was measured by Oil Red-O staining. In vivo, the experimental animals were divided into five groups: normal diet-fed normal group (N), high-fat diet (HFD)-fed control group (Con), HFD+SYJST 100 mg/kg group (SY100), HFD+SYJST 200 mg/kg group (SY200), and HFD+olistat 60 mg/kg as a positive drug control group (Orli). Markers of obesity, such as body weight, liver weight, food intake, serum total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), liver tissue TC, TG and fecal TC, TG were measured. Results In vitro, cytotoxicity was not significant compared with the control group. 3T3-L1 cell's differentiation was significantly decreased in Oil Red-O staining. In vivo, compared with controls, mice treated with SYJST demonstrate lower body and liver weight, and reduced food intake. In addition, SYJST increased TC, TG in the serum but not significance. And SYJST showed decreasing tendency TC, TG in the liver tissue. Furthermore, SYJST increased TC, TG in the facal but not significance. Conclusions Based on the results above, Seungyangjeseup-tang may reduce adipocyte differentiation, body fat, food intake, liver weight in obesity. This suggests that Seungyangjeseup-tang may be clinically useful in obesity treatment.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.87-109
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• 1998

The present study was designed to elucidate the effects of the Co-60 γ irradiation and/or calcium­deficient diet on the dentin and cementum formation of rat molar. The pregnant three-week old Sprague­Dawley rats were used for the study. The experimental group was divided into two groups, irradiation/normal diet group and irradiation/calcium-deficient diet group. The control group was non­irradiation/normal diet group. The abdomen of the rats at the 19th day of pregnancy were irradiated with single absorbed dose of 350cGy. The rat pups were sacrificed on the 14th day after delivery and the maxillae including molar tooth germ were taken. The specimens including the 1st molar tooth germ were prepared to make tissue sections for light and transmission electron microscopy. Some of tissue sections for light microscopy were stained immunohistochemically with anti-fibronectin antibody. The results were as follows; 1. The Hertwig's epithelial root sheath cells, which are related to the differentiation of the tooth-forming cells, showed irregular cellular arrangement, decrease of intercellular junctional complex, and decreased immunoreactivity to the fibronectin after irradiation. These were more severe in the irradiation/calcium-deficient diet group. 2. The cementoblasts at the cementum-forming area showed chromatin clumpings after irradiation. The immu noreactivity to the fibronectin was weaken after irradiation, especially irradiation/calcium-deficient diet group. 3. The odontoblasts at the dentin-forming area showed increase of lysosomes in the cytoplasm and destruction of intercellular junctional complex. The irradiation/calcium-deficient diet group showed decrease of number and density of the electron dense particles and a large number of vacuoles scattered in the dentin matrix. The immunoreactivity was weaken.

• The Journal of Korean Medicine
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• v.31 no.2
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• pp.137-148
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• 2010

Objective: This study aimed to evaluate the protective effects of Gamipalmi-hwan (GPH) on elastase-induced lung cell injury. Materials and Methods: As an in vitro model of emphysema, the current study was performed to investigate potential activity of GPH in regulating injury responses of A549 human type II cell line mediated by elastase treatment. Results: GPH treatment increased the number of A549 cells which was reduced by elastase digestion. Elastin protein level, which was reduced by elastase treatment, was increased by GPH treatment. Labeling intensity with caspase 3 protein in elastase-treated cells was reduced by GPH treatment. Both Erk1/2 and Cdc2 protein levels, which were decreased by elastase treatment, were increased to a level similar to that of the normal cells. mRNA levels encoding IL-$1{\beta}$ and TNF-$\alpha$ were increased by elastase and then down-regulated by GPH. Conclusion: The present data suggest that A549 cells are subjected to inflammatory damage by elastase and can be recovered by GPH treatment. Further studies examining the protective activity of GPH in elastase-treated lung tissue would be useful for therapeutic strategies of emphysema treatment.

• Biomedical Science Letters
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• v.16 no.4
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• pp.365-376
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• 2010

The purpose of this study was to clarify the effect of light emitting diode (LED) irradiation on healing of impaired wound and alteration of mast cells in experimental diabetic rats. Twenty-four male Sprague-Dawley rats were divided into four groups: excision (Ex), excision-LED irradiation (Ex-LED), diabetes + excision (DM) and diabetes + excision + LED irradiation (DM-LED). Diabetes was induced in rats by streptozotocin (STZ) injection (70 mg/kg, single dose) and 6 mm punch excision wounds were created on the back after shaving hair. The LED-irradiated rats were treated to a daily dose of $5\;J/cm^2$ LED (630 nm) light for 11 days after surgery, and were killed at day 1, 3, 7 and 11. The lesion and adjacent skin tissues were excised, fixed with 10% buffered formalin and embedded with paraffin. For evaluation of wound healing, hematoxylin-eosin (HE) and Masson trichrome staining were performed. Mast cells (MCs) were stained with toluidine blue (pH 0.5) and quantified using a computerized image analysis system. The proliferation activity of keratinocyte in skin tissues was analyzed on sections immunostained with proliferative cell nuclear antigen (PCNA). The results showed that wound healing rate, collagen density and neo-epidermis length, number of PCNA-positive cells, fibroblasts and mast cells were significantly higher in the LED-irradiated rats than in the DM and Ex rats throughout the periods of experiment. Exceptionally, the number of MCs was significantly lower at day 11 compared with day 7 after surgery in the all groups. These findings suggest that the LED irradiation may promote the tissue repair process by accelerating keratinocyte and fibroblast proliferation and collagen production in normal rats as well as in diabetic rats, and MCs may play an important role at an early stage of skin wound healing in normal and diabetic rats.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.1
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• pp.115-119
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• 1996

Myoepithelioma is composed exclusively of myoepithelial cells. Myoepithelial cells are ectodermally derived contractile cells that can be routinely identified in many normal tissues having secretory function such as major and minor salivary glands, lacrimal gland and sweat gland. Tumors composed exclusively of myoepithelial cells, so-called myoepitheliomas, are rare-less than 1% of all salivary gland tumors. Grossly, these tumors are well demarcated. The external surface is smooth and may be bosselated. The cut surface is white and homogenous. Microscopically, these tumors are surrounded by a thin fibrous capsule. They are composed of benign-appearing spindle- shaped and/or polygonal cells. Mitoses are rare. Frequently these tumors contain myxomatous stroma which is susceptible to alcial blue stain. Clinically, myoepitheliomas present as slow-glowing, painless masses and can not distinguished from pleomorphic adenomas. Treatment is the same as for pleomorphic adenoma, and the surgical excision should include a margin of normal tissue. Although the majority of myoepitheliomas have behaved in a beingn manner, pleomorphism and mitotic activity have been associated with local aggressiveness.