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        검색결과 6

        1.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Selenium is an essential micronutrient which functions as an essential constituent of selenoproteins. The selenoproteins play an important role in the body’s defense from free radicals associated with chronic diseases such as cancer. The effect of selenium on colon carcinogenesis was investigated using an experimental animal model. Five-week old ICR mice were acclimated for one week, and fed on the Fe-overloaded diet (450 ppm) with different Se diets (0.02, 0.1 or 0.5 ppm) for 12 weeks. Animals were injected intraperitoneally with azoxymethane (AOM, 10 mg/㎏ B.W. weekly for 3 weeks), followed by 2% dextran sodium sulfate (DSS) in the drinking water for a week. There were three experimental groups including low Se group (Lse), medium (normal standard diet for mice) Se (MSe), and high Se (HSe). The numbers of aberrant crypt foci (ACF) and aberrant crypt (AC) were measured in the colonic mucosa. The iron and selenium concentrations in liver was measured using ICP-AES. Glutathione peroxidase (GPx) activity was determined in the liver and colon. TUNEL assay for cell apoptosis and proliferating cell nuclear antigen (PCNA) staining for cell proliferation were performed. Immunohistochemical staining of β-catenin was also performed in mucous tissue of colon. The dietary Se decreased the numbers of ACF/㎠ and AC/㎠ in a dose-dependent manner. HSe diet significantly decreased the numbers of AC/㎠, compared with LSe diet (p<0.05). The tumor incidence rate in low Se diet group was 5% higher than medium Se diet group and 20% higher than high Se diet group. The activities of GPx in the liver and colon were dependent on the content of dietary selenium. Apoptosis-positive cells were also increased by dietary Se in a dose-dependent manner. PCNA-positive staining was weak in high Se group. β-catenin stained area was increased in low Se group while it was decreased in high Se group. These findings indicate that dietary selenium exert a protecting effect on colon cancer by inhibiting the development of ACF/AC, increasing GPX and apoptosis, and decreasing cell proliferation and expression of β-catenin in mice.
        4,000원
        2.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Selenium (Se) obtained from dietary sources is an essential micronutrient for normal body function and it functions as an essential constituent of selenoproteins. We investigated the influence of Se on the formation of colonic aberrant crpyt foci (ACF) and tumor formation induced by azoxymethane (AOM) and dextran sodium sulfate (DSS) in male ICR mice. Five-week old ICR mice were acclimated for one week and fed on the low iron diet (LFe, 4.5 ppm) and different Se diet [Lse (0.02 ppm), Normal Se (0.1 ppm), HSe (0.5 ppm)] for 12 weeks. Animals received intraperitoneal injections of AOM (10㎎/㎏ B.W. in saline weekly for 3 weeks), followed by 2% DSS (molecular weight 36,000~50,000) in the drinking water for a week. There were five experimental groups, including a normal control group, AOM/DSS, LFe+AOM/DSS, LFe+AOM/DSS+LSe, LFe+AOM/DSS+HSe. After sacrifice of animals, the total numbers of AC and ACF were measured in the colonic mucosa. The number of mice bearing tumors was expressed as tumor incidence rate. The iron and selenium liver concentration was measured using ICP-AES. Glutathione peroxidase (GPx) activity was determined using a GPx assay kit in the liver and colon. TUNEL and proliferating cell nuclear antigen (PCNA) staining were performed to examine the cell apoptosis and cell proliferation. In addition, immunohistochemistry of β-catenin was also performed on the mucous membrane tissue of colon. In AOM/DSS-induced colon carcinogenesis animal model, LFe diet decreased the number of 2.95±2.5 ACF/cm2 to 1.85±1.1 ACF/cm2 but it increased the total number of 5.06±4.2 AC/cm2 to 6.19±4.8 AC/cm2 compared with normal iron diet. In the iron-deficient mice, selenium did not affect the either the number of ACF or AC. The tumor incidence rate was higher in LFe diet groups than in normal iron diet group and high selenium diet weakly reduced the tumor incidence. Low selenium diet decreased the activity of GPx in the liver and colon. Apoptotic positive cells were decreased in the low selenium diet group. In addition, on the β-catenin staining, positive cells were increased in the low selenium diet group while they were decreased in the high selenium diet group. These findings indicate that the dietary levels of selenium was not highly enough to exhibit a significant protection against colon carcinogenesis in the iron-deficient mice. However, our results also indicate that dietary selenium might exert a protecting effect against colon cancer by increasing GPx activity and apoptosis and by inhibiting cell proliferation and β-catenin over-expression.
        4,500원
        4.
        2008.09 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to examine the promoting effect of herbal extracts on hair regrowth in C3H/HeJ mice. The herbal extracts were obtained from the Damo-cosmetics Inc. There were four experimental groups including distilled water (D. W., negative control), 20% ethanol (EtOH, vehicle control), 3% minoxidil (MXD, positive control), and herbal extract (Ext). The herbal extract included the mixture of water and alcohol extract from Pleuropterus multflorus, Lonicera japonica Thunberg, Phellinus linteus, and Phaseolus radiatus. Test compounds were applied to the shaved dorsal skin of mice mouse for 3 weeks. The photograph of hair regrowth was taken at day 0, 4, 7, 10, 14, 17, and 21. The herbal extract group showed faster hair regrowth than negative control group or 20% EtOH groups after 10 and 14 days of treatments. The elongation of hair follicles in MXD and the herbal extract groups were observed. The activities of alkaline phosphatase (ALP) and γ-glutamyl transpeptidase were sfanificantly (γ-GT) increased in MXD and herbal extract groups compared with negative control group (p<0.05). The expression of epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) were also sfanificantly hfaher in MXD and herbal extract group than negative control group (p<0.05), althouah there were no sfanificant differences amoularhe groups of 20% EtOH, MXD, and herbal extract. These results suagest that the herbal extract used in this study may have grpromoting effect on hair regrowth by increasing activities of ALP and γ-GT and expression of EGF and VEGF.
        4,000원
        5.
        2008.09 구독 인증기관 무료, 개인회원 유료
        Anti-wrinkle effect of herbal extracts was investigated on the skin of in a model of animal irradiated by ultraviolet rey B (UVB). The female albino hairless mice (HR/ICR) were randomly allocated to the normal control group (NC-non irradiated-vechicle), positive control group (PC, UVB irradiated vehicle) and herbal extract (HE) group. The herbal extract included the mixture of water and alcohol extract from Pleuropterus multflorus, Lonicera japonica Thunbert, Phellinus linteus, and Phaseolus radiatus. The herbal extract was treated dorsally with 0.2 ml per mouse five times a week for 12 weeks. At fifth week of the treatment, the animals were exposed to UVB irradiation for subsequent eight weeks three times a week. The intensity of irradiation was gradually increased from 30 mJ/㎠ to 240 mJ/㎠ (1MED: 60 mJ/㎠). Dorsal skins were obtained and stained with H&E to examine histological changes and epidermal/dermal thckness. The collagen fiber was also observed in Masson-Trichrome staining. Hydroxyproline assay and western blot analysis were also carried out to detect the change of collagen amount and to investigate MMP-1 expression, respectively. The HE group showed a better appearance and weak wrinkling, compared to PC group, The treatment of herbal extract significantly increased the thickness of dermis and the amount of collagen fibers compared to PC group (p<0.05). The treatment of HE significantly increased the hydroxyproline amount compared to PC group (p<0.05). The chronic UVB irradiation to hairless mice skin increased expression of MMP-1 but the treatment of HE decreased the expression of MMP-1. These results indicate that the herbal extract used in this study have a preventive effect on the UVB-induced wrinkle in a hairless mice model, partly due to the reduction of MMP-1 expression and increment of collagen amount.
        4,000원
        6.
        2011.02 KCI 등재 서비스 종료(열람 제한)
        This paper presents a frequency-response test performed on an antagonistic actuation system consisting of two Mckibben pneumatic artificial muscles and a pneumatic circuit. A linear model, capable of estimating the dynamic characteristics of the antagonistic system in the operating range of pneumatic artificial muscles, was optimally calculated based on frequency-response results and applied to a multiple simultaneous specification control scheme. Trajectory tracking results showed that the presented multiple simultaneous specification controller, built experimentally by three PD typed sample controllers, satisfied successfully all required control specifications; rising time, maximum overshoot, steady-state error.