• Title/Summary/Keyword: Cytotoxic Effect

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THE IMMUNE SUPPRESSIVE EFFECT FROM THE STRESS OF MAXILLOFACIAL OPERATIONS (구강악안면 영역의 수술이 인체내 세포면역성 억제에 미치는 영향)

  • Kim, Soung-Min;Lee, Suk-Keun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.29 no.2
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    • pp.108-115
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    • 2003
  • Suppression of cellular immunity is the host responses to surgical stress. When the body is exposed to surgical stress, decreased immunocyte function is one of the surgical stress-induced biologic responses. In all patients exposed to the surgical stress, peripheral blood lymphocyte numbers and function were suppressed until at least 2 weeks postoperatively. This immunosuppression was mainly due to a decrease of helper-inducer T cells, cytotoxic T cells, natural killer cells, and an increase of suppressor T cells. The blood levels of interleukin-6(IL-6) cytokine increase in response to surgical stress and cause an increase of so-called acute phase reactants, including C-reactive protein(CRP). In the previously damaged patients group, expected to early stress expose, immunosuppression was more developed than other normal groups. Cellular immunosuppression by surgical stress was mainly due to an increase of lymphocyte subsets that depress cellular immunity coupled with a decrease of the subsets that promote it. Overproduction of CRP in response to surgical stress may play an important role in the development of immunosuppression.

Induction of Functional Changes of Dendritic Cells by Silica Nanoparticles

  • Kang, Kyeong-Ah;Lim, Jong-Seok
    • IMMUNE NETWORK
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    • v.12 no.3
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    • pp.104-112
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    • 2012
  • Silica is one of the most abundant compounds found in nature. Immoderate exposure to crystalline silica has been linked to pulmonary disease and crystalline silica has been classified as a Group I carcinogen. Ultrafine (diameter <100 nm) silica particles may have different toxicological properties compared to larger particles. We evaluated the effect of ultrafine silica nanoparticles on mouse bone marrow-derived dendritic cells (BMDC) and murine dendritic cell line, DC2.4. The exposure of dendritic cells (DCs) to ultrafine silica nanoparticles showed a decrease in cell viability and an induction of cell death in size- and concentration-dependent manners. In addition, in order to examine the phenotypic changes of DCs following co-culture with silica nanoparticles, we added each sized-silica nanoparticle along with GM-CSF and IL-4 during and after DC differentiation. Expression of CD11c, a typical DC marker, and multiple surface molecules such as CD54, CD80, CD86, MHC class II, was changed by silica nanoparticles in a size-dependent manner. We also found that silica nanoparticles affect inflammatory response in DCs in vitro and in vivo. Finally, we found that p38 and NF-${\kappa}B$ activation may be critical for the inflammatory response by silica nanoparticles. Our data demonstrate that ultrafine silica nanoparticles have cytotoxic effects on dendritic cells and immune modulation effects in vitro and in vivo.

Stimulation of Phospholipase D in HepG2 Cells After Transfection Using Cationic Liposomes

  • Lee, Sang Yoon;Lee, Yan;Choi, Joon Sig;Park, Jong Sang;Choi, Myung-Un
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.931-935
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    • 2013
  • Lipid events in liposome-mediated transfection (lipofection) are largely unknown. Here we studied whether phospholipase D (PLD), an important enzyme responsible for phospholipid breakdown, was affected during lipofection of HepG2 cells with a luciferase plasmid. Synthetic cholesterol (Chol) derivatives, including $3{\beta}$[L-ornithinamide-carbamoyl]Chol, [polyamidoamine-carbamoyl]Chol and $3{\beta}$[N-(N',N'-dimethylaminoethane)-carbamoyl]Chol, and a cationic lipid, N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethylammonium chloride were mixed with a helper lipid dioleoylphosphatidylethanolamine to form respective cationic liposomes. All cationic liposomes were found to stimulate PLD. Although orders of magnitude effects of the cationic liposomes on PLD stimulation did not consistently match those on cytotoxicity and luciferase expression, a causal relationship between PLD activation and cytotoxic effect was remarkable. PLD stimulation by the cationic liposomes was likely due to their amphiphilic characters, leading to membrane perturbation, as supported by similar results obtained with other membrane-perturbing chemicals such as oleate, melittin, and digitonin. Our results suggest that lipofection induces cellular lipid changes such as a PLD-driven phospholipid turnover.

Syntheses of 5-Fluorouracil-Fat Conjugates and Evaluation of Their in vitro Cytotoxic Activity (5-Fluorouracil-지질 결합체 합성 및 in vitro 항암효과 평가)

  • Lee, Hee-Joo;Chang, Pan-Sup;Kim, Jae-Wan;Jung, Ki-Hwa;Shin, Soon-Hee;Shin, Hae-Soon;Jung, Soon-Bog
    • YAKHAK HOEJI
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    • v.34 no.6
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    • pp.395-400
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    • 1990
  • The FU-fat conjugates(4a-e) as a prodrug have been synthesized by condensing various fatty acids(1a-e) via isocyanates(2a-e) as carbamoyl group at $N^1-position$ of 5-fluorouracil and their structures characterized. Preliminary testing for their antitumor effect was carried out on leukemia L1210 cells in culture. Most of them(4a-d) like the parent FU exhibited less than 50% inhibition on grouth of the cultrued cells at the concentration of $1\;{\times\;10^{-7}M$. Only a dicarboxylic acid derivative, 4e, showed over 50% inhibition at the same level.

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Effect of Pleurotus ferulae Extracts on Viability of Human Lung Cancer and Cervical Cancer Cell Lines

  • Choi DuBok;Cha Wol-Suk;Kang Si-Hyung;Lee Byoung-Rai
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.5
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    • pp.356-361
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    • 2004
  • When SiHa cells were incubated for varying periods of time with extracts of PFF and PFM, the cytotoxicity of the ethanol extracts of PFF was higher than those of the other extracts. These results indicated that the extracts from fruiting bodies of p. ferulae contain antitumor Substances. When A549, SiHa and HeLa cells were incubated with different concentrations of PFF and PFM extracts, the ethanol extracts of PFF showed strong cytotoxicity against A549 tells at concentrations over $10{\mu}g/mL$ and against SiHa and HeLa cells at concentrations over $40{\mu}g/mL$. However, the differences in the cytotoxic effects of the hot water and ethanol extracts of PFM and the hot water extracts of PFF on all 3 cancer cells were not significant. Also, the PFF ethanol extracts induced synergistic effects on the TRAIL-induced apoptosis in A549 cells, which were strongly resistant to TRAIL. These results indicated that ethanol extracts of PFF were the most prominent antitumor agents toward lung cancer cells (A549).

Expression of Hepatitis B Virus X Protein in Hepatocytes Suppresses CD8+ T Cell Activity

  • Lee, Mi Jin;Jin, Young-hee;Kim, Kyongmin;Choi, Yangkyu;Kim, Hyoung-Chin;Park, Sun
    • IMMUNE NETWORK
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    • v.10 no.4
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    • pp.126-134
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    • 2010
  • Background: $CD8^+$ T cells contribute to the clearance of Hepatitis B virus (HBV) infection and an insufficient $CD8^+$ T cell response may be one of the major factors leading to chronic HBV infection. Since the HBx antigen of HBV can up-regulate cellular expression of several immunomodulatory molecules, we hypothesized that HBx expression in hepatocytes might affect $CD8^+$ T cell activity. Methods: We analyzed the activation and apoptosis of $CD8^+$ T cells co-cultured with primary hepatocytes rendered capable of expressing HBx by recombinant baculovirus infection. Results: Expression of HBx in hepatocytes induced low production of $interferon-{\gamma}$ and apoptosis of CD8+ T cells, with no effect on CD8 T cell proliferation. However, transcriptional levels of H-2K, ICAM-1 and PD-1 ligand did not correlate with HBx expression in hepatocytes. Conclusion: Our results suggest that HBx may inhibit $CD8^+$ T cell response by regulation of $interferon-{\gamma}$ production and apoptosis.

The involvement of oxygen free radicals in the onset of aging (노화에 미치는 산소 유리라디칼에 관한 연구동향)

  • Kim, Jung-Sang;Na, Chang-Su;Kim, Young-Kon
    • Korean Journal of Oriental Medicine
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    • v.3 no.1
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    • pp.229-239
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    • 1997
  • The superoxide anion radical$(O_2)$ poses a threat to macromocules and cell organelles of the living cells. This toxicity damage to all groups of proteins results in loss of enzyme function concerned with metabolism and ion transport, and peroxidation of unsaturated fatty acids and cholesterol results in a change of permeability characteristics of the membrane, and oxidative of nucleic acids results in genomic damage and thereby cause mutation, potential carcinogenesis and somatic damage that produce cellular aging Superoxide dismutase(SOD) has received substantial attention as a potential therapeutic agent. It has been investigated as a possible agent for the prevention of ontogenesis, the reduction of cytotoxic effect of anticancer drugs, and protection against damage in ischemic tissue. It is suggest that $O_2$ is concerned with cellular aging, thereafter we need to investigate herb that activated to SOD.

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Platycosides from the Roots of Platycodon grandiflorum and Their Health Benefits

  • Nyakudya, Elijah;Jeong, Jong Hoon;Lee, Nam Keun;Jeong, Yong-Seob
    • Preventive Nutrition and Food Science
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    • v.19 no.2
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    • pp.59-68
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    • 2014
  • The extracts and pure saponins from the roots of Platycodon grandiflorum (PG) are reported to have a wide range of health benefits. Platycosides (saponins) from the roots of PG are characterized by a structure containing a triterpenoid aglycone and two sugar chains. Saponins are of commercial significance, and their applications are increasing with increasing evidence of their health benefits. The biological effects of saponins include cytotoxic effects against cancer cells, neuroprotective activity, antiviral activity, and cholesterol lowering effects. Saponins with commercial value range from crude plant extracts, which can be used for their foaming properties, to high purity saponins such as platycodin D, which can be used for its health applications (e.g., as a vaccine adjuvant). This review reveals that platycosides have many health benefits and have the potential to be used as a remedy against many of the major health hazards (e.g., cancer, obesity, alzheimer's) faced by populations around the world. Methods of platycoside purification and analysis are also covered in this review.

Isolation and Characterization of Two Korean Mistletoe Lectins

  • Kang, Tae-Bong;Song, Seong-Kyu;Yoon, Taek-Joon;Yoo, Yung-Choon;Lee, Kwan-Hee;Her, Erk;Kim, Jong-Bae
    • BMB Reports
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    • v.40 no.6
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    • pp.959-965
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    • 2007
  • Two isolectins (KML-IIU and the KML-IIL) were individually isolated from the previously reported Korean mistletoe lectin, KML-C, by using an immunoaffinity column. Molecular weights of the KML-IIU and the KML-IIL were 64 kDa and 60 kDa respectively. Both of the lectins were composed of heterogeneous A and B subunits linked with a disulfide bond, and showed the same carbohydrate-binding specificities for Gal and GalNAc. However, they are different not only in biophysical properties (glycosylation and amino acid compositions) but also bioactivities (cell killing and cytokine induction). The KML-IIL showed 17-145 times stronger in cytotoxicities to various human and mouse cancer cell lines than the KML-IIU. The KML-IIL also induced TNF-$\alpha$ secretion from mouse peritoneal macrophages 4.5 times better than the KML-IIU. The results demonstrated isolectins in Korean mistletoe were varied in bioactivities and the KML-IIL may be developed as an anti-cancer agent.

Comparison of the Biological Activities of Electrodialysis-desalted Bioactive Compounds from the Halophyte Suaeda japonica (전기투석시스템을 활용한 염생식물 칠면초(Suaeda japonica) 추출물의 염분 표준화에 따른 주요 성분 및 생리활성 비교 연구)

  • Park, Hyeon-Ho;Ko, Seok-Chun;Jung, Won-Kyo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.49 no.2
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    • pp.124-130
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    • 2016
  • To effectively remove salts from Suaeda japonica, extracts, an electrodialysis system was developed. The biological activities of non-desalted (NDS) and desalted S. japonica (DS) extracts were compared. The DS extract exhibited superior polyphenolic (6.26%) and carbohydrate (28.56%) contents. The IC50 values of the DS extract against DPPH radicals and hydrogen peroxide were 0.22 and 0.68 mg/mL, respectively, which was higher than that of the NDS extract. Neither the DS nor the NDS extract was cytotoxic in RAW 264.7 macrophages. Additionally, the DS extract had a higher NO inhibitory effect compared to the NDS extract in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. These data indicate that DS extracts have greater biological activity than do ND extracts, and application of the electrodialysis process may be useful in marine bioresource applications.