• 한국환경보건학회지
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• 제28권2호
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• pp.71-80
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• 2002

To evaluate the skin toxicity of topical cyclohexane application (25mg/$\textrm{cm}^2$) was sequentially applied to the rat skin for four days. On the histopathological findings in the light micrographs, neutrophils and engulfed neutrophils are seen, and many cytoplasmic processes were appeared in proliferated layer whereas in the dermis area, increased numbers of fibroblast, accumulation of neutrophil and lipid droplets are demonstrated. On the other hand, applying the cyclohexane to the rat skin led to the remarkable rise of cutaneous xanthine oxidase activity and similar activities of superoxide dismutase and glutathione peroxidase and glutathione content and declined activity of glutathione S-transferase compared with control group. Especially the remarkably decreased activity of aniline hydroxylase (AH) was appeared in skin as little as scarcely determined. Furthermore, the applying the cyclohexane to skin led to the significantly increased activity of hepatic AH and alcohol dehydrogenase. These results indicate that oxygen free radical and intermediate metabolite of cyclohexane may be responsible for structural changes in skin by cyclohexane application to rat skin.

• 대한의생명과학회지
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• 제8권2호
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• pp.83-88
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• 2002

To investigate the skin toxicity of xylene, xylene (25 mg/$\textrm{cm}^2$) has been sequentially applied to the rat skin for four days. On the light microscopic examination, epithelium was left out with infiltration of inflammatory cells in border with dermis, and formation of new epithelial layer was shown under the inflammatory zone. Application of xylene to the rat skin showed the marked rise of cutaneous xanthine oxidase activity whereas, He activities of oxygen free radical scavenging enzymes, superoxide dismutase and glutathione S-transferase, were significantly declined. Furthermore, the content of cutaneous glutathione was more and less decreased in rat skin applied with xylene. In conclusion, these results suggest that a part of oxygen free radical may be responsible for morphological changes in skin by applying xylene to the rat skin.

• Toxicological Research
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• 제17권1호
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• pp.33-39
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• 2001

To evaluate the skin toxicity oj topical toluene application, toluene (35 mg/$cm^2$) was sequentially applied to the portion rat skin for five days. The topical toluene application resulted in increased xanthine oxidase activity and CYP content, and significantly decreased superoxide dismutase and glutathione peroxidase activities at five days in rat skin. Especially catalase activity was remarkably decreased in toluene-applied rat skin. And benzylalcohol dehydrogenase activity showed also a significant decrease in toluene-applied skin. On the other hand, histopathological ultrastructural examination revealed disrupted epidermal basement membrane, rared intercellular adhensions and degenerated keratin layer due to topical toluene application. Increased deposit of cerrous perhydroxide resulted from reaction with $H_2O_2$was abserved in toluene-treated animals. These results indicate that oxygen free radical may be responsible for ultrastructural changes in skin tissue by toluene application to rat skin.

• 한국방사선학회논문지
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• 제10권6호
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• pp.375-379
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• 2016

방사선장해 극복을 위한 조직공학실험에서는 다양한 실험방법이 존재한다. 그중에서도 방사선 장해모델을 구현함에 있어서 쥐는 가장 많이 사용되는 실험동물이다. 이번 실험에서는 쥐 피부를 벗긴 후 일정한 두께로 만든 후에 피부 두께에 따른 방사선량을 측정하였다. 또한 쥐의 피부 두께에 따른 방사선 흡수선량을 유추해 날수 있는 수식을 도식화 하였다. 결론적으로 이러한 수식을 적용한다면 방사선장해극복을 위한 조직공학 연구에서 사용하는 다양한 지지체삽입시에 지지체가 받을 수 있는 방사선량의 정도를 유추해 낼 수 있으며 이것을 통하여 쥐 피부두께 피하에 관한 체내 (in-vitro)실험모델 구현 시 방사선량의 정보를 제공하고자 한다. 따라서 이번 연구의 결과를 기반으로 사용한다면 방사선이 노출된 쥐의 피하조직 체내 (in-vitro) 조직공학 실험에서 효과적으로 사용 될 수 있을 것이다.

• 한국전기전자재료학회논문지
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• 제20권12호
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• pp.1087-1092
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• 2007

We developed the 4-channel Light Medical Therapy Apparatus for Skin Injury Cure using a high brightness LED. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity and reservation. In this paper, the designed device was used to find out how high brightness LED light affects the skin injury of SD-Rat(Sprague-Dawley Rat). In the experiment, $1\;cm^2$ wounds on the skin injury of SD-Rat(Sprague-Dawley Rat) were made. Light irradiation group and none light irradiation group divided, each group was irradiated one hour a day for 14 days. In result, compared with none light irradiation group, the lower incidence of inflammation and faster recovery was shown in light irradiation group.

• 대한의생명과학회지
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• 제7권1호
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• pp.47-51
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• 2001

To investigate an effect of the topical toluene application to .at skin on the liver injury, toluene (35 mg/$cm^2$) was sequentially applied for 3 or 5 days to rat skin and then the animals were sacrificed. 5 day toluene-treated rats showed the slight increase of live. weight per body weight(%) compared with control. Serum levels of xanthine oxidase and alanine aminotransferase activity were significantly increased both in 3 days and 5 days toluene-treated animals compared with control. In the histopathological findings, cytoplasmic degeneration of hepatocytes around the central vein was noted in the liver of rats applied with toluene to the skin. These results indicate toluene application to rat skin feds to somewhat slight liver injury. On the other hand, the hepatic benzylalcohol or aldehyde dehydrogenase activities were significantly decreased by toluene application to rat skin. In conclusion, the liver min was induced by toluene application to rat skin, and it can be hypothesized that accumulation of benzaldehyde in liver cell may be responsible for liver injury.

• 대한화장품학회지
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• 제27권1호
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• pp.29-42
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• 2001

We had prepared MLV liposome with Hibiscus Esculentus Ext.(HEE) which have fluorescent light in order to evaluate its percutaneous absorption about hairless rat skin. Then we investigated particle size of MLV using confocal laser scanning microscope(CLSM) and transmission electron microscope(TEM), respectively. Stability of MLV liposome and penetration of MLV liposome to hairless rat skin was measured by CLSM. As a result of experiments, MLV was globular shape and the rage of particle size was 0.3-0.5$\mu\textrm{m}$ mostly. Cream-type MLV had high stability comparatively. When we treated with MLV to rat skin, skin penetration was enhanced, especially, the optimum concentration of MLV on penetration to rat skin was 10%. Optimum penetration time was 6hr-12hr. And MLV-type HEE was more effective on percutaneous absorption than HEE-cream or liposome-type HEE.

• Archives of Pharmacal Research
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• 제19권2호
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• pp.116-121
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• 1996

Antisense oligonucleotides seem to provide a promising new tool for the therapy. Choi et al. (1995) reported antisense phosphorothioate oligonucleotides (PS-ODN, 25 mer) complementary to TGF-.betha. mRNA designed for scar formation inhibitor to eliminate scars, which was caused by undesired collagen deposition due to overexpression of TGF-.betha., in wounded skin. PS-ODN were evaluated in vitro for skin penetration using normal and tape-stripped damaged rat skin. The in vitro skin transports were carried out with partially modified PS-ODN (6S) and fully modified PS-ODN (25S). The cumulative amount of PS-ODN (6S) penetrated through normal rat skin was $0.234{\pm}0.041{\mu}g/cm^2$ and that of tape-stripped damaged rat skin was $1.077{\pm}0.301{\mu}g/cm^2$ over 8 hrs. PS-ODN (25S) can not be found in receptor medium through normal skin due to high molecular weight (Mol.Wt.=8,000) and polyanionic charge. However, the cumulative amount of PS-ODN (25S) penetrated across damaged rat skin in PBS was $0.340{\pm}0.296{\mu}g/cm^2$ over 8 hrs. The absense of dermis raised the cumulative amount of PS-ODN (6S) penetrated through rat skin. And the fluxes of PS-ODN (6S) and PSODN (25S) at 8hrs across damaged rat skin were $134.63{\pm}37.67{\mu}g/cm^2$ h, and $42.50{\pm}36.95ng/cm^2$ h, respectively. While PS-ODN (25S) was stable in 10% heat inactivated fetal bovine serum (FBS) during 24 hrs, PS-ODN (6S) was less stable than PS-ODN (25S), but was markedly stable than unmodified phosphodiester. It is suggested that the cumulative amount of PS-ODN (6S) penetrated through damaged rat skin is larger than that of PS-ODN (25S) since the former is easier to degrade by nuclease than the latter and then is apt to penetrate into skin. Thus, PS-ODN represents a logical candidate for further evaluation due to the potential for delivery into the wounded skin.

• Journal of Pharmaceutical Investigation
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• 제24권3호spc1호
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• pp.27-32
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• 1994

In order to reduce systemic side effects following oral administration, flurbiprofen was formulated as transdermal gels consisting of the drug, poloxamer 407 and ethanol in buffer solutions. The effect of formulation variables in the preparation of flurbiprofen gels on skin permeation of the drug was evaluated using Keshary-Chien diffusion cells fitted with excised rat skins. The permeation rate of flurbiprofen through rat skin was directly proportional to initial drug concentration (between 0.1% and 1.0%) in the gel while it was inversely proportional to poloxamer 407 concentration (between 17.5% and 25%). The skin permeation of flurbiprofen was substantially influenced by the gel pH between 3 and 7, exhibiting a maximum at pH 4. The concentration effect of ethanol on the permeation of the drug was negligible in the concentration range of $10{\sim}20%$.

• 한국식품영양과학회지
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• 제19권6호
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• pp.583-590
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• 1990

Free and esterified forms of provitamin D in 30-day-old mele rat skin were isolated and quantitated using silicic acid column chromatography and high-performance liquid chromatography(HPLC) systems. Two forms of free provitamin D(cholesta-5, 7-dien-$3{\beta}$-ol and cholesta-5, 7, 24-trien-$3{\beta}$-ol) and at least thirteen esterified forms of provitamin D were isolated. The average total concentration of provitamin D in the whole skin was $6,056ng/cm^2$. The skin contained $846ng/cm^2$ of free provitamin D and $5,209ng/cm^2$ of esterified provitamin D. The proportion of esterified provitamin D in the skin was 86%.