• Title/Summary/Keyword: Activation agents

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Lack of Mutations in Protein Tyrosine Kinase Domain Coding Exons 19 and 21 of the EGFR Gene in Oral Squamous Cell Carcinomas

  • Mehta, Dhaval Tushar;Annamalai, Thangavelu;Ramanathan, Arvind
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4623-4627
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    • 2014
  • Background: The epidermal growth factor receptor (EGFR) plays a vital role in the activation and inactivation of receptor tyrosine kinases. Mutations in exons 19 and 21 of EGFR are commonly found to be associated with non small cell lung carcinoma and triple negative breast cancer, enhancing sensitivity to EGFR targeting chemotherapeutic agents. Since amplification and prolonged activation of EGFR molecules have been identified in oral squamous cell carcinomas (OSCC), we investigated whether OSCCs carried mutations in exons 19 and 21 of EGFR to their incidence. Materials and Methods: Tumor chromosomal DNA isolated from forty surgically excised oral squamous cell carcinoma tissues was subjected to PCR amplification with intronic primers flanking exons 19 and 21 of the EGFR gene. The PCR amplicons were subsequently subjected to direct sequencing to elucidate the mutation status. Results: Data analysis of the EGFR exon 19 and 21 coding sequences did not show any mutations in the forty OSCC samples that were analyzed. Conclusions: To the best of our knowledge, this is the first study to have investigated the genetic status of exons 19 and 21 of EGFR in Indian OSCCs and identified that mutation in EGFR exon 19 and 21 may not contribute towards their genesis. The absence of mutations also indicates that oral cancerous lesions may not be as sensitive as other cancers to chemotherapeutic agents targeting EGFR.

Biological control of Colletotrichum panacicola on Panax ginseng by Bacillus subtilis HK-CSM-1

  • Ryu, Hojin;Park, Hoon;Suh, Dong-Sang;Jung, Gun Ho;Park, Kyungseok;Lee, Byung Dae
    • Journal of Ginseng Research
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    • v.38 no.3
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    • pp.215-219
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    • 2014
  • Background: Biological control of plant pathogens using benign or beneficial microorganisms as antagonistic agents is currently considered to be an important component of integrated pest management in agricultural crops. In this study, we evaluated the potential of Bacillus subtilis strain HK-CSM-1 as a biological control agent against Colletotrichum panacicola. Methods: The potential of B. subtilis HK-CSM-1 as a biological control agent for ginseng anthracnose was assessed. C. panacicola was inoculated to ginseng plants and the incidence and severity of disease was assessed to examine the efficacy of the bacterium as a biological control against C. panacicola. Results: Inoculation of Panax ginseng plants with B. subtilis significantly suppressed the number of disease lesions of C. panacicola and was as effective as the chemical fungicide iminoctadine tris(albesilate). The antifungal activity of B. subtilis against C. panacicola was observed on a co-culture medium. Interestingly, treatment with B. subtilis did not significantly affect the diameter of the lesions, suggesting that the mechanism of protection was through the reduction in the incidence of infection related to the initial events of the infection cycle, including penetration and infection via spore germination and appressorium formation rather than by the inhibition of invasive growth after infection. Conclusion: Our results suggest that B. subtilis HK-CSM-1 can be used as an effective and ecologically friendly biological control agent for anthracnose in P. ginseng.

Relationship of Inhibitory Effects of Dichroa febrifuga and $IKK{\gamma}$ on the Activation of $NF-{\kappa}B$ (상산의 $NF-{\kappa}B$ 활성억제작용과 $IKK{\gamma}$의 연관성 연구)

  • Choi, Byung-Tae;Lee, Yong-Tae;Hwang, Jang-Sun;Moon, Hae-In;Lee, Kyung-Soo;An, Won-Gun;Kim, Dong-Wan
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.3
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    • pp.651-656
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    • 2006
  • Activation of $NF-{\kappa}B$ is known to be a trigger of various cellular disorders including inflammatory and autoimmune diseases such as rheumatoid arthritis. Numerous approaches are ongoing within laboratories to identify potential therapeutic agents which inhibit the $NF-{\kappa}B$ activation. In this study, we have tested the inhibitory effects of five traditional medicines on the activation of $NF-{\kappa}B$ by NIK. Among three medicines which exhibited inhibitory effect on the expression of $NF-{\kappa}B$ repoter plasmid, we investigated further the inhibitory mechanism of Dichroa febrifuga in connection with IKKY activity. Wild type $IKK{\gamma}$ inhibited the $NF-{\kappa}B$ activation by NIK but the C-terminal deletion mutant of IKKY did not show the inhibitory effect, indicating that the C-terminal leucine zipper domain of $NF-{\kappa}B$ is important for the inhibition of $NF-{\kappa}B$ activation. The water extract of Dichroa febrifuga(DFE) also strongly inhibited the $NF-{\kappa}B$ activation by NIK. The inhibitory activity of DFE appeared to be independent of the expression of $IKK{\gamma}$, suggesting that the pathways of inhibition by Dichroa febrifuga and $IKK{\gamma}$ are different. Our results suggest that Dichroa febrifuga can be used as a medicine for inhibition of the $NF-{\kappa}B$ activation in a wide range of cells without relation to the expression of $IKK{\gamma}$.

The Preparation of Activated Carbon from Coffee Waste: ZnCl2-Activation (커피폐기물을 이용한 활성탄의 제조: ZnCl2-활성화)

  • You, S.H.;Kim, H.H.
    • Applied Chemistry for Engineering
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    • v.9 no.4
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    • pp.509-515
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    • 1998
  • Activated coffee chars were prepared from coffee waste by chemical activation with zinc chloride. In this study, the following processes were carried out ; roasting step, carbonization step, chemical activation step, and washing and drying step. The roasting step of coffee waste was carried out at $300{\sim}400^{\circ}C$ for 10 minutes. The optimum condition of carbonization was at $650^{\circ}C$ for 1 hour. The most important parameter in chemical activation of coffee char was found to be the chemical ratio of activation agents. Activated coffee chars prepared by various activation methods were characterized in terms of the nitrogen BET surface area, the BJH pore volume and pore size distribution at 77 K. The $N_2$-BET surface areas and total pore volume of coffee chars prepared by the chemical activation with $ZnCl_2$ were determined as about $1110{\sim}1580m^2/g$ and $0.51{\sim}0.81cm^3/g$, respectively. Scanning Electron Microscopy (SEM) was used to observe the porosity and surface of activated coffee chars. From the results of SEM analysis, it was shown that active surface and many pores were formed after the chemical activation. The preparation of the activated coffee char from coffee waste was successfully carried out, which previews a possibility for exploitation of resources by recycling the waste.

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Microtubule-damaging Chemotherapeutic Agent-mediated Mitotic Arrest and Apoptosis Induction in Tumor Cells (미세소관-손상 항암제 처리에 의한 세포주기의 정지 및 에폽토시스 유도)

  • Jun, Do Youn;Kim, Young Ho
    • Journal of Life Science
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    • v.26 no.3
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    • pp.376-386
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    • 2016
  • Apoptosis induction has been proposed as an efficient mechanism by which malignant tumor cells can be removed following chemotherapy. The intrinsic mitochondria-dependent apoptotic pathway is frequently implicated in chemotherapy-induced tumor cell apoptosis. Since DNA-damaging agent (DDA)-induced apoptosis is mainly regulated by the tumor suppressor protein p53, and since more than half of clinical cancers possess inactive p53 mutants, microtubule-damaging agents (MDAs), of which apoptotic effect is mainly exerted via p53-independent routes, can be promising choice for cancer chemotherapy. Recently, we found that the apoptotic signaling pathway induced by MDAs (nocodazole, 17α-estradiol, or 2-methoxyestradiol) commonly proceeded through mitotic spindle defect-mediated prometaphase arrest, prolonged Cdk1 activation, and subsequent phosphorylation of Bcl-2, Mcl-1, and Bim in human acute leukemia Jurkat T cells. These microtubule damage-mediated alterations could render the cellular context susceptible to the onset of mitochondria-dependent apoptosis by triggering Bak activation, Δψm loss, and resultant caspase cascade activation. In contrast, when the MDA-induced Bak activation was inhibited by overexpression of anti-apoptotic Bcl-2 family proteins (Bcl-2 or Bcl-xL), the cells in prometaphase arrest failed to induce apoptosis, and instead underwent mitotic slippage and endoreduplication cycle, leading to formation of populations with 8N and 16N DNA content. These data indicate that cellular apoptogenic mechanism is critical for preventing polyploid formation following MDA treatment. Since the formation of polyploid cells, which are genetically unstable, may cause acquisition of therapy resistance and disease relapse, there is a growing interest in developing new combination chemotherapies to prevent polyploidization in tumors after MDA treatment.

Intracellular Signaling Pathways for Type II IgE Receptor (CD23) Induction by Interleukin - 4 and Anti - CD40 Antibody

  • Kim, Hyun-Il;Park, Hee-Jeoung;Lee, Choong-Eun
    • BMB Reports
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    • v.30 no.6
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    • pp.431-437
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    • 1997
  • Since the role of CD40 on the interleukin-4(IL-4) -induced B cell activation has been strongly implicated in the agumentation of IgE production and response, we have investigated the intracelluar signaling pathways utilized by IL-4 and CD40 for type II IgE receptor (CD23) expression. IL-4 and anti-CD40 antibody treatment of human B cells, independently caused a rapid induction of CD23 gene activation within 2 h. There was a noticeable synergism between the action of the two agents inducing CD23 expression: the addition of anti-CD40 to the IL-4-treated culture significantly agumented the IL-4-induced CD23 on both mRNA and surface protein levels, and the inclusion of IL-4 in the anti-CD40-treated cells caused a further increase of CD23 expression far above the maximal level induced by anti-CD40. Protein tyrosine kinase (PTK) inhibitors effectively suppressed the both IL-4- and anti -CD40-induced CD23 expression. whereas protein kinase C (PKC) inhibitors had no effects. Electrophoretic mobility shift assays (EMSA) have shown that IL-4 and anti-CD40 induce the activation of NF-IL-4 and $NF-_{K}B$, respectively, binding to the CD23 promoter, both in a PKC-independent and PTK-dependent manner. These data suggest that the synergistic activation of CD23 gene expression by IL-4 and anti-CD40 is mediated by co-operative action of distinct nuclear factors. each of which is rapidly activated via PKC-independent and PTK-dependent process.

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The Root from Heracleum moellendorffii Exerts Anti-Inflammatory Activity via the Inhibition of NF-κB and MAPK Signaling Activation in LPS-Stimulated RAW264.7 Cells

  • Park, Su Bin;Kim, Ha Na;Kim, Jeong Dong;Park, Gwang Hun;Son, Ho-Jun;Eo, Hyun Ji;Song, Jeong Ho;Jeong, Hyung Jin;Jeong, Jin Boo
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.10a
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    • pp.96-96
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    • 2018
  • Although the roots of Heracleum moellendorffii (HM-R) have been long treated for inflammatory human diseases, scientific evidence for the anti-inflammatory activity of HM-R is not sufficient. In this study, we investigated anti-inflammatory activity and mechanism of action of HM-R in LPS-stimulated RAW264.7 cells. HM-R blocked LPS-induced NO and PGE2 production, but not HM-L. HM-R inhibited LPS-induced overexpression of iNOS, COX-2, $IL-1{\beta}$ and IL-6 in RAW264.7 cells. HM-R inhibited LPS-induced $NF-{\kappa}B$ signaling activation through blocking $I{\kappa}B-{\alpha}$ degradation and p65 nuclear accumulation. In addition, HM-R inhibited MAPK signaling activation by attenuating the phosphorylation of ERK1/2, p38 and JNK. Furthermore, HM-R inhibited attenuated LPS-mediated overexpression of the osteoclast-specific factors such as NFATc1, cathepsin K, MCP-1 and TRAP. These results indicate that HM-R may exert anti-inflammatory activity by inhibiting $NF-{\kappa}B$ and MAPK signaling activation. From these findings, HM-R has potential to be a candidate for the development of chemopreventive or therapeutic agents for the inflammation and inflammatory diseases.

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Cell to Cell Interaction Can Activate Membrane-bound APRIL Which Are Expressed on Inflammatory Macrophages

  • Lee, Sang-Min;Kim, Won-Jung;Suk, Kyoung-Ho;Lee, Won-Ha
    • IMMUNE NETWORK
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    • v.10 no.5
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    • pp.173-180
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    • 2010
  • Background: APRIL, originally known as a cytokine involved in B cell survival, is now known to regulate the inflammatory activation of macrophages. Although the signal initiated from APRIL has been demonstrated, its role in cellular activation is still not clear due to the presence of BAFF, a closely related member of TNF superfamily, which share same receptors (TACI and BCMA) with APRIL. Methods: Through transfection of siRNA, BAFF-deficient THP-1 cells (human macrophage-like cells) were generated and APRIL-mediated inflammatory activities were tested. The expression patterns of APRIL were also tested in vivo. Results: BAFF-deficient THP-1 cells responded to APRIL-stimulating agents such as monoclonal antibody against APRIL and soluble form of TACI or BCMA. Furthermore, co-incubation of the siBAFF-deficient THP-1 cells with a human B cell line (Ramos) resulted in an activation of THP-1 cells which was dependent on interactions between APRIL and TACI/BCMA. Immunohistochemical analysis of human pathologic samples detected the expression of both APRIL and TACI in macrophage-rich areas. Additionally, human macrophage primary culture expressed APRIL on the cell surface. Conclusion: These observations indicate that APRIL, which is expressed on macrophages in pathologic tissues with chronic inflammation, may mediate activation signals through its interaction with its counterparts via cell-to-cell interaction.

Production of Activated Carbon from Woody Fishing Port Wastes Using Sulfuric Acid as Activating Agent (목질(木質) 어항(漁港) 폐기물(廢棄物)을 원료(原料)로 한 황산(黃酸)에 의한 활성탄(活性炭) 제조(製造))

  • Kim, Dong-Su;Lee, Jung-Eun
    • Resources Recycling
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    • v.15 no.2 s.70
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    • pp.50-57
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    • 2006
  • Production of activated carbon from woody fish parking cases has been studied using waste sulfuric acid as an activating agent for the purpose or promoted recycling of woody fishing port wastes. The adsorption capacity of produced activated carbon was observed to increase with activation temperature and reached its maximum at ca. $650^{\circ}C$ under the experimental conditions. However, the adsorption capacity of activated carbon became deteriorated above this temperature due to the thermal degeneration of its structure. Optimal activation time was found to be about 120 minutes and 1:3 weight ratio of raw material and activating agent was appropriate for increased adsorption capacity of activated carbon under the conditions of $550^{\circ}C$ and 60 minutes of activation time. Regarding the effect of the concentration of activating agent on activation, ca. 1.2 M of sulfuric acid was observed to be proper for an optimal activation or raw material. Comparison of the activation power of sulfuric acid with nitric acid showed that sulfuric acid was superior to nitric acid, however, with regard to the yield of activated carbon there was no significant difference between the two activating agents. The degree of dispersion of carbon particles was shown to be relatively high in neutral condition and the produced activated carbon was considered to be effectively employed for the treatment of metal ions in wastewater due to its negative surface charge in aqueous condition.

Genetic Toxicity Study of YH1715 Series, Antifungal Agents (YH1715계열 항진균제의 유전독성평가)

  • 하광원;오혜영;박장환;허옥순;손수정;한의식;이종영;김소희;강희일
    • Environmental Mutagens and Carcinogens
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    • v.18 no.2
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    • pp.93-97
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    • 1998
  • The results of chromosome aberration test in mammalian cells in culture (Chinese hamster lung fibroblast cells) showed no induction of structural and numerical aberrations by antifungal agents of YH1715 series regardless of metabolic activation. While positive control group (mitomycin C and benzo(a)pyrene) showed structural chromosome aberrations of 37% and 23%, respectively. The in vivo induction of micronuclei was measured in polychromatic erythrocytes in bone marrow of male ddY mouse given YH1715R and YH1729R at 1, 0.5, 0.25 g/kg by p.o. once. After 24 hours, animals were sacrificed and evaluated 40 the incidence of micronucleated polychromatic erythrocytes in whole erythrocytes. Although a positive response for induction of micronuclei in animals treated with mitomycin C demonstrated the sensitivity of the test system for detection of a chemical clastogen, YH1715R did not induce micronuclei in bone marrow of ddY male mice but induced cytotoxicity to bone marrow cells at the highest concentration (1 g/kg, p〈0.05), and YH1729R induced micronuclei in bone marrow of ddY male mice dose dependently (p<0.05) but did not induce cytotoxicity to bone marrow cells.

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