• 한국전자현미경학회:학술대회논문집
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• 1994.05a
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• pp.19-20
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• 1994

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1010-1014
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• 2004

High quality GaN layer and $In_xGa_{1-x}N$ alloy were obtained on (0001)sapphire substrate using ammonia$(NH_3)$ and dimethylhydrazine$(DMH_y)$ as a nitrogen source by gas source molecular hem epitaxy(GSMBE) respectively. As a result, RHEED is used to investigate the relaxation processes which take place during the growth of GaN and $In_xGa_{1-x}N$. The full Width at half maximum of the x-ray diffraction(FWHM) rocking curve measured from Plane of GaN has exhibitted as narrow as 8 arcmin. Photoluminescence measurement of GaN and $In_xGa_{1-x}N$ were investigated at room temperature, where the intensity of the band edge emission is much stronger than that of deep level emission. In content of $In_xGa_{1-x}N$ epitaxial layer according to growth condition was investigated.

• Proceedings of the KSCN Conference
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• 2002.05a
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• pp.462.1-462
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• 2002

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.431-438
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• 2019

The present study was designed to investigate the chemopreventive effects of supercritical heat radish extracts with anti-constipation acitivity in loperamide-treated rats, on 1,2-dimethylhydrazine(DMH)-induced aberrant crypt foci(ACF) in rat colonic mucosa. Supercritical heat radish extracts was administered in the drinking water(3.2 mg/ml) during the initiation (for 12 weeks) or postinitiation phase(for 9 weeks) of DMH-induced carcicogenesis. Supercritical heat radish extracts coupled with DMH for 12 weeks decreased significantly total number of aberrant crypts(pre-neoplastic lesions) and the number of ACF to 35% and 30%, respectively. The number of ACF with more than four aberrant crypts (crypt multiplicity) was significantly reduced in the colon of rats receiving Supercritical heat radish extracts for 12 weeks. In the group receiving Supercritical heat radish extracts after post-initiation for 9 weeks, only the number of ACF with ${\geq}4$ abberant crypts significantly decreased. Supercritical heat radish extracts, given alone for 12 weeks, did not induced the development of ACF. These results indicate that Supercritical heat radish extracts possess chemopreventive effects on chemically induced rat colon carcinogenesis.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.1064-1068
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• 2007

We evaluated the effect of soybean dongchunghacho [SD, cultivated dongchunghacho fungus (Paecilomyces tenuipes) on soybeans] on dimethylhydrazine (DMH)-induced DNA damage and oxidative stress in male F344 rats. The animals were divided into 3 groups and fed a casein-based high-fat, low fiber diet without (DMH group) or with 13%(w/w) of soybean (DMH+S group), or SD (DMH+SD group). One week after beginning the diets, rats were treated weekly with DMH (30 mg/kg, s.c.) for 6 weeks; dietary treatments were continued for the entire experiment and endpoints measured at 9 weeks after the first DMH injection. SD supplementation reduced DMH-induced DNA damage in colon cells and reduced plasma lipid peroxidation. Thus, SD may have therapeutic potential for early-stage colon carcinogenesis.

• Proceedings of the Korean Nutrition Society Conference
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• 2003.10a
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• pp.154-154
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• 2003

• Toxicological Research
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• v.23 no.4
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• pp.321-330
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• 2007

Garlic (Allium sativum L.) with the food supplement material and medicine was used traditionally in Asia and Europe. Epidemiological studies revealed that the intake of garlic reduced incidences of various cancer including digestive system. The present study was designed to investigate the effect of garlic ethanol extract on the development of colonic aberrant crypt foci (ACF) induced by 1,2-dimethylhydrazine (DMH) in male F344 rats. Five-week-old rats were given four times for two weeks to subcutaneous injections by DMH (30 mg/kg body weight) to induce ACF. The animals were divided into groups that fed diet containing garlic ethanol extract at five different doses (0.1, 0.2, 0.5, 2, 5%), respectively, animals were evaluated for the total number of ACF and total aberrant crypts (AC) per colon detected from methylene blue-stained rat colon. ACF were formed in animals in DMH-treated group. The feeding suppressed potently the appearance ACF in the colon of rats. Especially, fed diet containing garlic ethanol extract at intermediate dose (0.5%) significantly reduced the number of ACF and AC per colon (p < 0.05). Garlic ethanol extract inhibited DMH-induced overexpression of Activator Protein-1 (AP-1) and ${\beta}-catenin$ genes related to cell proliferation that also upregulated the expression of p21Waf1/Cip1 mRNA, a cell cycle-regulating gene. These results suggested that garlic ethanol extract may inhibit ACF formation, ${\beta}-catenin$ gene as the early preneoplastic marker of malignant potential in the process of colon carcinogenesis.

• Journal of Nutrition and Health
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• v.31 no.9
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• pp.1394-1403
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• 1998

The study was designed to observe the effect of dietary calcium and fats on plasma cholesterol level, hepatic microsomal fluidity and HMG-CoA reductase activity as well as the excretion of fecal bile acids and neutral sterols in 1, 2-dimethylhydrazine(DMH)-treated rats. Male Sprague Dawley rats, at 7 weeks of age, were divided into 2 groups, 0.3% and 1.0% Ca levels and each group again subdivided into 2 groups of corn oil and perilla oil. Each rat was intramuscularly infused with DMH for 6 weeks to give total dose of 180mg/kg body weight and also fed experimental diet containing 15%(w/w) different fit and Ca(0.3% or 1.0%) for 20 weeks. High dietary calcium(1.0%) did not significantly influence on plasma cholesterol as well as hepatic microsomal fluidity and HMG CoA reductase activity, but significantly reduced the excretion of total bile acid per gram of faces and increased the excretion of total neutral sterol. However, high dietary Ca reduced the excretion of secondary bile acid(deoxycholic and lithocholic acids) which was known as promoter for colon cancer. Perilla oil rich in n-3 ${\alpha}$-linolenic acid significantly decreased plasma cholesterol by increasing hepatic microsomal fluidity compared with corn oil, but did not influence on HMG CoA reductase activity. Perilla oil did not influence on fecal excretion of total and primary bile acids, but reduced the excretion of secondary bile acids. Therefore, it could be recommended to consume more fish product and food rich in calcium and use more perilla oil in meal preparation to prevent from coronary hear disease and colon cancer especially when high fit diet has been practiced. (Korean Nutrition 31(9) : 1394-1403, 1998)

• Archives of Plastic Surgery
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• v.34 no.1
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• pp.8-12
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• 2007

Purpose: Protein tyrosine kinase(PTK), protein kinase C(PKC), oxidase, as a mediator, have been known to take a role in signal transduction pathway of angiogenesis. The authors confirmed that PKC is the most noticeable mediator for abnormal proliferation of vascular endothelial cells through in vitro study model using the inhibitors, targeting the formation of three co-enzymes. In this study, we would investigate which isoform of PKC play an important role in abnormal angiogenesis of vascular endothelial cell. Methods: In 96 well plates, $10^4$ HUVECs(human umbilical vein endothelial cells) were evenly distributed. Two groups were established; the control group without administration of DMH(1,2-dimethylhydrazine) and the DMH group with administration of $7.5{\times}10^{-9}M$ DMH. RNA was extracted from vascular endothelial cell of each group and expression of the PKC isoform was analyzed by RT-PCR(reverse transcriptase-polymerase chain reaction) method. Results: RT-PCR analysis showed that $PKC{\alpha}$, $-{\beta}I$, $-{\beta}II$, $-{\eta}$, $-{\mu}$ and $-{\iota}$ were expressed in vascular endothelial cells of each group. DMH incresed the expression of $PKC{\alpha}$ and $PKC{\mu}$, and decreased $PKC{\beta}I$, $PKC{\beta}II$ expression dominantly. Conclusion: Based on the result of this study, it was suggested that $PKC{\alpha}$ and $PKC{\mu}$ may have significant role in abnormal proliferation of vascular endothelial cell.

• Natural Product Sciences
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• v.5 no.1
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• pp.48-53
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• 1999

There are epidemiological evidences that the population with high fecal ${\beta}-glucuronidase$ activity has greater risk of colon cancer than the population with low fecal ${\beta}-glucuronidase$. This relationship was investigated by using the mouse-dimethylhydrazine colon carcinogenesis model and the extract of antler which was a ${\beta}-glucuronidase$ inhibitor. Mice with low fecal ${\beta}-glucuronidase$ activity induced by administration of water and Folch's fraction of antler had significantly fewer aberrant crypts after injections of 1,2-dimethylhydrazine (DMH) than mice treated with DMH alone. The result supports the hypothesis that the inhibitor of ${\beta}-glucuronidase$ such as antler extract can protect an animal against the induction of colon cancer.