• Journal of Life Science
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• v.10 no.6
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• pp.605-609
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• 2000

In order to evaluate the safety of hydroxyapatite sinter produced from tuna bone in Syrian hamsters, oral mucous membrane irritation test was carried out. Oral mucous membrane irritation test was infected in Syrian hamsters as dose of 5 g/kg BW with hydroxyapatite sinder under pentobarbital sodium anesthesia. Each animal`s left cheek pouch was everted, and the samples were loosely placed at the bottom of the pouch with a double-suture technique for 14 days. Hamsters of control group were treated without inserting the hydroxylapatite sinter. Any abnormal clinical signs in both cheek pouches of control and treatment group were not observed for 14 days. There were no significant differences in body weight changes between hamsters of control and treatment group. Therefore, it suggest that hydroxyapatite sinter produced from tuna bone has no particular changes of oral mucous membrane irritation in Syrian hamsters.

• Journal of Embryo Transfer
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• v.10 no.3
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• pp.243-250
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• 1995

Frozen storage of the oocytes has been used in a few mammalian species including mouse, hamster, human and cattle. However, frozen4hawed oocvtes show different sperm penetration on the levels of the zona pellucida and the plasma memhrane when compared with fresh oocytes. To elucidate biological changes occurring during freezing and thawing, we examined the kinetics of sperm penetration into frozen-thawed hamster oocytes. Oocytes obtained from superovulated female golden hamsters were frozen-thawed in an autofreezer according to an established method. Fresh and frozen4hawed oocytes were fertilized in vitro with capacitated hamster spermatozoa after removing the zona pellucida. The oocytes were examined at 1, 2, 3 and 6 h postinsemination. Sperm penetration found to be 1 h delayed in frozen-thawed oocytes. Other parameters such as degree of polyspermy and decondensing sperm heads were not affected by freezing and thawing. The results suggest that freezing and thawing may cause changes in the egg membrane surface and subsequently which leads to delay in the sperm-egg fusion.

• Applied Microscopy
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• v.27 no.3
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• pp.281-293
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• 1997

The effects of antimetabolite, 6-aminonicotinamide (6-AN), on ultrastrudural changes in the spinal cord of golden hamster were investigated. Intraperitoneal administration of 6-AN (10 mg/kg body weight) every two days gave rise to a marked reduction of about $30\sim40%$ in body weight after $26\sim28$ days ($13\sim14th$ injection). In the lesions of the spinal cord, neuroglial cells such as astrocytes and oligodendrocytes were severely damaged, but neurons and blood vessels were not affected by 6-AN. The myelin sheath was also affected by 6-AN. Vacuoles observed in the lesions were produced by the swelling and degenerating changes of neuropils and neuroglial cells. Numerous swollen mitochondria and cisterns of rough endoplasmic reticulum were observed in the watery cytoplasm of damaged neuroglial cells, but intermediate filaments were well preserved. Especially in the damaged astrocytes, the outer nuclear membrane were partially swollen and formed a halfmoonlike structure. It is suggested that as well as the multivesicular bodies protruding from the swollen dendrites, the conjugation of adjacent vacuoles also participated in the formation of large vacuoles.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.271-272
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• 2018

제4차 산업혁명시대에서 강조하는 SW교육은 컴퓨팅 관련 교과 뿐만 아니라 타 교과에서도 그 중요성이 대두되고 있으며, 따라서 정보과 교사가 아닌 비 정보과 교사들에게도 SW 교사 연수의 필요성이 높아지고 있다. 따라서 본 연구에서는 선행 연구들의 고찰을 통하여 비 정보과 교사를 위한 햄스터로봇을 활용한 SW 교사 연수 프로그램을 개발하였다.

• Journal of Veterinary Clinics
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• v.19 no.4
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• pp.464-466
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• 2002

A case of spindle cell tumor was presented in a 16-month-old, female syrian hamster. In the left chest area, a 3cm firm elevated recurrent mass was found, surgically removed, and submitted to the Department of Veterinary Pathology, Seoul National University for diagnosis. The mass was soft to firm and tan on sectioning, and contained hemorrhagic area. Histologically, the tumor was composed of sheets of interlacing bundles of spindle-shaped cells with moderate amount of cytoplasm and oval to fusiform nuclei. They were plemorphic and contained 1 to 3 prominent nucleoli. Based on the gross and histological findings, the tumor was diagnosed as a subcutaneous spindle cell tumor. However, the exact origin of neoplastic cells remained undetermined.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.2
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• pp.215-226
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• 1993

The purpose of this study was to investigate the effects of the low level irradiation on the mitotic index of the basal cells in the buccal pouch of hamsters{golden hamster: APG strain). After colchicine was administrated to the hamsters through the intraperitoneal, the low level radiation{5460mR) was exposed on the buccal pouch of hamsters. The mitotic index of the basal cells was estimated 2 hours after irradiation. The results were as follows: 1. The mean mitotic index of the control group was 4.32. 2. The mean mitotic index of the irradiated group was 2.46. 3. T-test of data in the irradiated group showed significant difference from the mitotic index in the control group. These results suggested the lowered mitotic index of the irradiated group resulted from the low level irradiation.

• YAKHAK HOEJI
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• v.51 no.1
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• pp.75-82
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• 2007

Reactive oxygen species (ROS) are produced in the metabolic process of oxygen in cells. The superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in cells systemize the antioxidant enzymes to control the oxidative stress. Genistein is one of the isoflavonoids, and its role in controlling cellular oxidative stress is presently the active issue at question. In this study; we analyzed genistein-induced survival rates of the CHO-K1 cells, activities of antioxidant enzymes, ROS levels, and expression levels of antioxidant enzyme genes in order to investigate the effect of genistein on cellular ROS production and antioxidative systems in CHO-K1 cells. As results, the survival rate of cells was decreased as the dose of genistein increases (12.5${\sim}$200 ${\mu}$M). Genistein increased cellular ROS levels, while it reduced total SOD activities and the expression of CuZnSOD. In conclusion, we suggest that genistein may induce oxidative stress via down-regulation of SOD.

• Journal of Life Science
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• v.20 no.1
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• pp.1-8
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• 2010

We recently reported the distributions of AMPA ($\alpha$-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate) receptor subtypes glutamate receptors (GluR) 1 and GluR4 in the superior colliculi (SC) of hamsters with antibody immunocytochemistry and the effect of enucleation on these distributions. We also compared these labelings to those of calcium-binding proteins calbindin D28K, calretinin, parvalbumin, and GABA. In the present study, we investigated whether the GluR1- and GluR4-immunoreactive (IR) neurons are interneurons or projection neurons by injection of the retrograde tracer horseradish peroxidase (HRP) into one of each major ascending and descending pathways of the SC. HRP injections were made into a tecto-reticulospinal pathway (TRS) and dorsal lateral geniculate nucleus (dLGN). Animals were then allowed to recover and to survive for 48 hr before perfusion. Sections containing retrograde-labeled neurons were then treated for GluR-immunoreactivity. HRP injections proved that only a small population of the GluR1-IR cells project into TRS (1.4%) and dLGN (2.6%). However, a large subpopulation of GluR4-IR cells project into TRS (32.7%). The differential compositions of inter/projection neurons, along with our previous studies on the separate distribution of the GluR subunits, its differential co-localization with calcium-binding proteins and GABA, and differential reactions to enucleations, strongly imply the functional variety of the receptor subunits in visual behavior responses.

• Journal of dental hygiene science
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• v.2 no.1
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• pp.25-29
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• 2002

In the present study, we tried to investigate whether poly-L-lysine(PLL)(MW 78,000 and 9,600) significantly affect mucin release from cultured hamster airway goblet cells. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled with $^3H$-glucosamine for 24 hr and chased for 30 min in the presence of varying concentrations of PLL to assess the effects on $^3H$-mucin release. Possible cytotoxicities of PLL were assessed by measuring Lactate Dehydrogenase(LDH) release during treatment. The results were as follows : (1) PLL significantly inhibited mucin release from cultured HTSE cells in a dose-dependent manner; (2) there was no significant release of LDH by treatment of PLL 9,600; (3) however, in the case of treatment of PLL 78,000, there was significant release of LDH during treatment. We conclude that PLL which has molecular weight under 10,000 might inhibit mucin release from airway goblet cells without significant cytotoxicity. This finding suggests that PLL might be used as a tool of research for the hypersecretion of airway mucus.

• Applied Biological Chemistry
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• v.44 no.2
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• pp.122-128
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• 2001

This review showed a discussion on the biofunctional activities of citrus flavonoids. The major flavonoids of citrus species, hesperidin, hesperetin, naringin, and naringenin, were selected to evaluate their biological effects on the lipid metabolism in rats and hamsters, the proliferation of human hepatocyte HepG2 cells, and the antioxidative effect in lipid peroxidation models. These flavonoids showed hypotriglyceridemic effect in hamsters and hypochloesterolemic effect in rats. They also significantly inhibited the activities of phosphatidate phophohydrolase and acyl-CoA: cholesterol acyltransferase, which are key enzymes for biosynthesis of triglyceride and cholesterol, repectively, in vivo and in vitro experiments. These biofunctional activities by citrus flavonoids were shown more potent in the aglycone flavonoids, hespreretin and naringenin, than their corresponding glycoside flavonoids, hesperidin and naringin. These aglycone flavonoids also have inhibitory effects on proliferation of human hepatocyte cancer HepG2 cells. Hesperidin showed lowering activities of cellular triglyceride and cholesterol concentrations in HepG2 cells. Citrus flavonoids have significant importance in functional food industry as biofunctional active ingredients.