• 폴리머
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• 제26권4호
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• pp.415-421
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• 2002

E-beam 전조사법을 이용하여 HPP-g-styrene 공중합체와 술폰화 반응을 통한 술폰화 HPP-g-styrene 섬유이온교환체를 합성하였다. 그라프트율은 스티렌 단량체 농도가 증가함에 따라 증가하였으며 스티렌 단량체 농도가 80%에서 그라프트율이 128%로 최대를 나타냈다. 술폰화율은 그라프트율이 증가함에 따라 증가하는 경향을 나타내었으며, 그라프트율이 100%일 때 13.4%로 최대값을 나타내었다. 술폰화 HPP-g-styrene 섬유이온교환체의 이온교환용량은 약 3.42 meq/g으로써 흡착 성능이 매우 우수한 소재임을 확인하였다. BET 분석결과 술폰화 HPP-g-styrene의 비표면적은 62.54 $m^2/g$, 기공크기는 25 $\AA$으로 반응전보다 비표면적은 감소하였고 기공크기는 약간 증가하는 경향을 보였다. 또한 Bovine Serum Albumin (BSA) 흡착 실험 결과 술폰화도가 증가함에 따라 BSA 흡착 용량이 증가하는 경향을 나타내었으며, 술폰화도 13.4%에서 BSA 흡착용량 3.8 mg/g으로 최대를 나타내었다. 따라서 본 연구에서 합성한 섬유이온교환체가 BSA 흡착.분리에 적합한 소재임을 확인하였다.

• Macromolecular Research
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• 제10권3호
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• pp.150-157
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• 2002

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a microbial storage polymer with biodegradable properties. In order to improve the cell compatibility of PHBV surfaces, the physicochemical treatments have been demonstrated. In this study, physical method was corona discharge treatment and chemical method was chloric acid mixture solution treatment. The physicochemically treated PHBV film surfaces were characterized by the measurement of water contact angle, electron spectroscopy for chemical analysis, and scanning electron microscopy (SEM). The water contact angle of the physicochemically treated PHBV surfaces decreased from 75 to 30～40 degree, increased hydrophilicity. due to the introduction of oxygen-based functional group onto the PHBV backbone chain. The mouse NIH/3T3 fibroblasts cultured onto the physicochemically treated PHBV film surfaces with different wettability. The effect of the PHBV surface with different wettability was determined by SEM as counts of cell number and [$^3$H]thymidine incorporation as measures of cell proliferation. As the surface wettability increased, the number of the cell adhered and proliferated on the surface was increased. The result seems closely related with the serum protein adsorption on the physicochemically treated PHBV surface. In conclusion, this study demonstrated that the surface wettabilily of biodegradable polymer as the PHBV plays an important role for cell adhesion and proliferation behavior for biomedical application.

• Archives of Pharmacal Research
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• 제28권3호
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• pp.311-318
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• 2005

Oxidative stress has been reported to elevate ceramide level during cell death. The purpose of the present study was to modulate cell death in relation to cellular glutathione (GSH) level and GST (glutathione S-transferase) expression by regulating the sphingolipid metabolism. LLC­PK1 cells were treated with H$_2$O$_2$ in the absence of serum to induce cell death. Subsequent to exposure to H$_2$O$_2$, LLC-PK1 cells were treated with desipramine, sphingomyelinase inhibitor, and N-acetylcysteine (NAC), GSH substrate. Based on comparative visual observation with H202-treated control cells, it was observed that 0.5 $\mu$M of desipramine and 25 $\mu$M of NAC exhibited about 90 and $95\%$ of cytoprotection, respectively, against H$_2$O$_2$-induced cell death. Desipramine and NAC lowered the release of LDH activity by 36 and $3\%$ respectively, when compared to $71\%$ in H$_2$O$_2$-exposed cells. Cellular glutathione level in 500 $\mu$M H202-treated cells was reduced to 890 pmol as compared to control level of 1198 pmol per mg protein. GST P1-1 expression was decreased in H$_2$O$_2$-treated cells compared to healthy normal cells. In conclusion, it has been inferred that H$_2$O$_2$-induced cell death is closely related to cellular GSH level and GST P1-1 expression in LLC-PK1 cells and occurs via ceramide elevation by sphingomyelinase activation.

• Journal of Ginseng Research
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• 제41권2호
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• pp.159-168
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• 2017

Background: Radiotherapy is one of the most important modalities in cancer treatment; however, normal tissue damage is a serious concern. Drug development for the protection or reduction of normal tissue damage is therefore a clinical issue. Herein, we evaluated the protective properties of Panax ginseng Meyer and its corresponding mechanisms. Methods: C56BL/6 mice were orally pretreated with P. ginseng water extract (PGE; 25 mg/kg, 50 mg/kg, or 100 mg/kg) or intraperitoneally injected melatonin (20 mg/kg) for 4 d consecutively, then exposed to 15-Gy X-ray radiation 1 h after the last administration. After 10 d of irradiation, the biological properties of hematoxicity, fat accumulation, histopathology, oxidative stress, antioxidant activity, pro-inflammatory cytokines, and apoptosis signals were examined in the hepatic tissue. Results: The irradiation markedly induced myelosuppression as determined by hematological analysis of the peripheral blood. Steatohepatitis was induced by X-ray irradiations, whereas pretreatment with PGE significantly attenuated it. Oxidative stress was drastically increased, whereas antioxidant components were depleted by irradiation. Irradiation also notably increased serum liver enzymes and hepatic protein levels of pro-inflammatory cytokines. Those alterations were markedly normalized by pretreatment with PGE. The degree of irradiation-induced hepatic tissue apoptosis was also attenuated by pretreatment with PGE, which was evidenced by a terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick-end labeling assay, western blotting, and gene expressions analysis, particularly of apoptotic molecules. Conclusion: We suggest that PGE could be applicable for use against radiation-induced liver injury, and its corresponding mechanisms involve the modulation of oxidative stress, inflammatory reactions, and apoptosis.

• 한국임상수의학회지
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• 제27권1호
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• pp.23-28
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• 2010

Mycobacterium avium ssp paratuberculosis, intracellular bacteria that can cause chronic granulomatous enteritis in cattle, continues to pose significant economic losses and health problem with high prevalence. The purpose of this study is the polymerase chain reaction (PCR)-base strategy for early detection of M. avium ssp paratuberculosis in whole blood. Blood samples were collected from korean cattles in Jeonbuk, Korea. The 16 out of 88 serum samples were detected M. partuberculosis by ELISA. Then samples of infected 8 Korean cattles were amplified by PCR. The PCR amplified targets are 16s rDNA and heat shock protein 65kDa (hsp 65). The 16s rDNA provided a highly sensitive and specific tool for the direct detection of mycobacteria. In addition M. avium was confirmed characteristically by the hsp65. Finally there were sure to M. avium ssp paratuberculosis by IS900 PCR. The restriction fragment length polymorphism was identified by PCR amplifications and subsequence restriction enzyme digestions with Pst I of a hsp65. These results indicate that confirm M. avium with 16s rDNA, hsp65 and a restriction fragment length polymorphism in the hsp65 gene can be seem the other pattern. Therefore, these results can be used for clinical direct detections of M. avium ssp paratuberculosis in whole blood of Korean cattle and also to be used epidemiological researches.

• 치위생과학회지
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• 제18권3호
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• pp.188-193
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• 2018

The aim of the current study was to demonstrate the potential therapeutic efficacy of resveratrol in oral cancer patients. Lysophosphatidic acid (LPA) intensifies cancer cell invasion and metastasis, whereas resveratrol, a natural polyphenolic compound, possesses antitumor activity, suppressing cell proliferation and progression in various cancer cell lines (ovarian, gastric, oral, pancreatic, colon, and prostate cancer cells). In addition, resveratrol has been identified as an inhibitor of LPA-induced proteolytic enzyme expression and ovarian cancer invasion. Furthermore, resveratrol was shown to inhibit oral cancer cell invasion by downregulating hypoxia-inducible factor $1{\alpha}$ and vascular endothelial growth factor expression. Recently, we demonstrated that LPA is important for the expression of transcription factors TWIST and SLUG during epithelial-mesenchymal transition (EMT) in oral squamous carcinoma cells. In this study, we treated serum-starved cultures of oral squamous carcinoma cell line YD-10B with resveratrol for 24 hours prior to stimulation with LPA. To identify an optimal resveratrol concentration that does not induce apoptosis in oral squamous carcinoma cells, we determined the toxicity of resveratrol in YD-10B cells by assessing their viability using the MTT assay. Another assay was performed using Matrigel-coated cell culture inserts to detect oral cancer cell invasion activity. Immunoblotting was applied for analyzing protein expression of SLUG, TWIST1, E-cadherin, and GAPDH. We demonstrated that resveratrol efficiently inhibited LPA-induced oral cancer cell EMT and invasion by downregulating SLUG and TWIST1 expression. Therefore, resveratrol may potentially reduce oral squamous carcinoma cell invasion and metastasis in oral cancer patients, improving their survival outcomes. In summary, we identified new targets for the development of therapies against oral cancer progression and characterized the therapeutic potential of resveratrol for the treatment of oral cancer patients.

• Animal cells and systems
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• 제1권4호
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• pp.641-646
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• 1997

Lysophosphatidic acid (LPA; 1-acyl-glycerol-3-phosphate) has been known as an intercellular phospholipid messenger with a wide range of biological activities. In this study, the effect of LPA on both the proliferation and differentiation of rat E63 myoblasts has been investigated. In the serum-free Insulin-Transferrin-Selenium (ITS) media, the proliferation of E63 cells was largely restricted. Addition of LPA into the ITS media strongly promoted the cell proliferation and resulted in two to four fold increase of cell number. Furthermore, it appeared to increase the percent fusion in a dose-dependent manner up to 15 ug/ml. The synthesis of myosin heavy chain (MHC) was increased by LPA as well. These results indicate that LPA is able to promote both cell proliferation and differentiation in rat E63 myoblasts. Suramin, known to have uncoupling activity on growth factor-receptor interaction, was tested for antagonistic activity in myoblast proliferation and differentiation. Myoblasts grown in the ITS medium containing LPA were able to proliferate well even in the presence high concentration of suramin whereas myoblast differentiation was completely blocked by 30 ug/ml of suramin. The inhibitory effect of suramin on the myoblast differentiation was completely reversible by removing the suramin. This result indicates that the intracellular signaling pathway of LPA leading to cell proliferation might be distinct from that leading to cell differentiation on E63 myoblasts. Also, the antagonistic effect of suramin suggests that the differentiation activity elicited by LPA might be mediated by a specific G protein-coupled receptor.

• 한국임상수의학회지
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• 제22권2호
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• pp.108-113
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• 2005

This study was performed to investigate the growth rate, hematological and serological changes of the rats when they were fed with the high fat diets supplemented with or without the tannic acid for five weeks. Thirty-two Sprague-Dawley male rats(235.7\pm10.7g\;of\;body\;weight)$ were randomly divided into four groups, control group and three treatment groups(T1, T2 and T3). Rats in control group were fed with the high fat diet containing $15\%\;lard,\;1\%$ cholesterol and $0.5\%$ sodium cholate(wt/wt) which was modified from the formula of American Institute of Nutrition (AIN)-76 diet and rats in treatment groups were fed with above diet supplemented with $0.25\%(T1),\;0.5\%(T2)$ or $0.75\%(T3)$ of tannic acid(wt/wt), respectively. The supplementation of tannic acid(TA) did not affect the final body weight, gain of body weight and feed intake of rats in both control and treatment groups. The numbers of red blood cells, hemoglobin concentrations and hematocrit values in blood of rats showed no significant differences between control group and treatment groups. The glucose concentration and albumin/globulin(A/G) ratio of rats in treatment groups were slightly lower than that of control group without significance. The values of total protein, albumin and globulin showed no significant differences between control group and treatment groups. The values of total cholesterol, low density lipoprotein­cholesterol and atherogenic index in sera of rats in treatment groups were much lower than that of control group without significance. The values of triglycerides in sera of rats in T3 group were significantly lower than that of control group (p<0.05). The values of AST and ALT in sera of rats in T3 group were significantly lower than that of control group (p<0.05). Thus supplementation of tannic acid to high fat diet could be effective to reduce the serum lipid levels such as total cholesterol, high density lipoprotein-cholesterol and triglycerides which were regarded as to cause the cardiovascular diseases.

• Molecules and Cells
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• 제20권2호
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• pp.263-270
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• 2005

Transactivation of EGF-receptor (EGFR) by G-protein coupled receptors (GPCRs) is emerging as an important pathway in cell proliferation, which plays a crucial role in the development of atherosclerotic lesion. Angiotensin II (Ang II) has been identified to have a major role in the formation of atherosclerotic lesions, although the underlying mechanisms remain largely unclear. We hypothesize that Ang II promotes the proliferation and migration of smooth muscle cells through the release of heparin-binding epidermal growth factor like growth factor (HB-EGF), transactivation of EGFR and activation of Akt and Erk 1/2, with matrix metalloproteases (MMPs) playing a dispensable role. Primary rat aortic smooth muscle cells were used in this study. Smooth muscle cells rendered quiescent by serum deprivation for 12 h were treated with Ang II (100 nM) in the presence of either GM6001 ($20{\mu}M$), a specific inhibitor of MMPs or AG1478 ($10{\mu}M$), an inhibitor of EGFR. The levels of phosphorylation of EGFR, Akt and Erk 1/2 were assessed in the cell lysates. Inhibition of MMPs by GM6001 significantly attenuated Ang II-stimulated phosphorylation of EGFR, suggesting that MMPs may be involved in the transactivation of EGFR by Ang II receptor. Furthermore Ang II-stimulated proliferation and migration of smooth muscle cells were significantly blunted by inhibiting MMPs and EGFR and applying HB-EGF neutralization antibody, indicating that MMPs, HB-EGF and EGFR activation is necessary for Ang-II stimulated migration and proliferation of smooth muscle cells. Our results suggest that inhibition of MMPs may represent one of the strategies to counter the mitogenic and motogenic effects of Ang II on smooth muscle cells and thereby prevent the formation and development of atherosclerotic lesions.

• 한국식품과학회지
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• 제29권5호
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• pp.1067-1070
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• 1997

Chelating sepharose fast flow gel에 $Cu^{2+}$을 고정화시키고 이들과 단백질과의 친화력 정도에 의해서 용출용매를 통해 단백질을 분획하는 방식의 IMAC법을 이용하여 소의 혈장단백질로부터 IgG의 분리를 시도하였다. 대부분의 혈장단백질은 1차(0.01 M $Na_2HPO_4$, 0.5 M NaCl, pH 4.0)와 2차 용출용매(0.01 M imidazol)에 의하여 용출되었으며 역상 chromatography를 이용하여 각 분획의 단백질조성을 조사한 결과, 1차 용출용매에 의해서는 주로 albumin이, 그리고 2차 용출용매에 의해서는 IgG와 transferrin 등이 IMAC column으로부터 용출되었다. 2차 용출용매에 의해 얻어진 분획으로부터 분자량 100 kD이상의 단백질을 한외여과장치를 이용하여 농축하였을 때, IgG가 효과적으로 분리 정제 되었다.