• Title, Summary, Keyword: Synergism

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Cytokine Synergism in Apoptosis: Its Role in Diabetes and Cancer

  • Lee, Myung-Shik
    • BMB Reports
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    • v.35 no.1
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    • pp.54-60
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    • 2002
  • The effects of individual cytokine on apoptosis have been extensively studied. However, the effect of the cytokine combination, or the synergistic effect of cytokines on cell death, has not been widely studied, though synergism between cytokines has been documented in a variety of biological situations. In our effort to identify the final death effector molecule(s) in autoimmune diabetes, we inadvertently became interested in the cytokine synergism. We discovered that $IFN{\gamma}/TNF{\alpha}$ synergism, rather than the Fas ligand as currently believed, is responsible for the apoptosis of pancreatic islet cells both in vitro and in vivo. We also studied similar cytokine synergism in cancer cell deaths, and noted the similarities and dissimilarities between cancer cell death and islet cell death.

Antioxidation synergism between ZnDTC and ZnDTP in mineral oil

  • Du, Da-Chang;Kim, Seock-Sam;Chun, Jung-Sik;Kwon, Wan-Seop;Suh, Chang-Min
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.305-312
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    • 2001
  • Antioxidation synergism between ZnDTC and ZnDTP in a kind of mineral base oil was investigated by RBOT. The results indicate that there is antioxidation synergism between the two additives. FTIR analysis show that the oxidation products in the tested oils containing the two additives are much less than those in the tested oils containing the single additive alone.

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Thermal Behavior of Flame-Retardant Polyester Fibers (II) -Synergism of Bronline Compounds/Antimony Trioxide- (방염 폴리에스테르 섬유의 열적거동 (II) -브롬화합물/산화안티몬의 상승작용-)

  • Lee, Ui-So;Song, Gyeong-Geun;Go, Seok-Won
    • Textile Science and Engineering
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    • v.28 no.5
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    • pp.62-67
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    • 1991
  • This study was undertaken to elucidate bromine-antimon Synergism of the Polyester fabrics treated with a mixture of organobromine compounds/antimony trioxide. For this purpose fide aromatic bromine compounds with a relatively high bromine content such as DBDPO, OB-DPO, HBCD, PBT, and HBB were chosen. Polyester fabrics were treated with the aqueous dispersion solution of a mixture of bromine compounds/antimony trioxide together with binder. Bromine-antimony synergism was confirmed by plotting the LOI values against bromine/antimony weight ratio. Bromine-antimony synergism was inferred by comparing thermogravimetric and differential thermal analysis curves of a mixture of bromine compounds/antimony trioxide with those combined mathematically from thermogravimetric and differential thermal analysis curves of bromine compounds and antimony trioxide, respectively.

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Synergism among Endo-xylanase, $\beta$-Xylosidase, and Acetyl Xylan Esterase from Bacillus stearothermophilus

  • Suh, Jung-Han;Choi, Yong-Jin
    • Journal of Microbiology and Biotechnology
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    • v.6 no.3
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    • pp.173-178
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    • 1996
  • Synergic effects among endo-xylanase, $\beta$-xylosidase, and acetyl xylan esterase of Bacillus stearothermophilus in the hydrolysis of xylan were studied by using birchwood, oat spelt, and acetylated xylan as substrates. Synergism between endo-xylanase and $\beta$-xylosidase was observed on all three substrates tested, indicating that $\beta$-xylosidase enhanced the production of xylose by relieving the end-product inhibition upon endo-xylanase conferred by xylooligomers. Endo-xylanase and $\beta$-xylosidase also showed synergism with acetyl xylan esterase in the hydrolysis of birchwood and acetylated xylan, while no synergic effect was detected in oat spelt xylan hydrolysis. Thus, the hydrolysis of xylan containing acetic acid side chains required the action of acetyl xylan esterase, which eliminated the steric hindrance of the side chains, leading to the better hydrolysis by endo-xylanase and $\beta$-xylosidase , and the acetyl xylan esterase activity was also enhanced by endo-xylanase and $\beta$-xylosidase for the latter enzymes provided acetyl xylan esterase with shorter xylan oligomers, the better substrate for the enzyme.

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Antibacterial Activity of Magnolol and Honokiol in Combination with Antibiotics (Magnolol 및 Honokiol의 항생제와의 병용 효과)

  • Chung, Kyeong-Soo;Lee, Soo-Na;Kim, Young-Ho;Bae, Ki-Hwan
    • Korean Journal of Pharmacognosy
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    • v.31 no.4
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    • pp.407-411
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    • 2000
  • Antibacterial activities of magnolol (MGL) and honokiol (HKL) in combination with four representative antibiotics-amoxicillin (AMPC), oxytetracyclin (OTC), gentamicin (GM) and chloramphenicol (CAP)-were evaluated against four bacterial strains. When tested by disk-plate method, five out of eight combinations such as HKL-AMPC, HKL-CAP, MGL- AMPC, MGL-OTC, and MGL-CAP showed additive to synergistic interaction against gram- negative bacterium Salmonella typhimureum. Of these, MGL-AMPC combination turned out to be antagonistic against Sarcina lutea and Bacillus thurungiensis. Against these two grain-positive bacteria, only HKL-GM combination showed additivity to synergism. All the other combinations showed no interactions. Despite these results, however, no synergism was observed in checkerboard titration assay.

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Synergism effect of mixed surfactant solutions in remediation of soil contaminated with PCE

  • Lee, Dal-Heui
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.47-51
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    • 2004
  • The purpose of this research was to evaluate the effect of mixed surfactant solution for removal of perchloroethylene (PCE) in soil. Ten different surfactant solutions were used in column studies. Mixed surfactant solutions (anionic and nonionic) were most effectively worked in the sandy soil for removal of PCE as a result of synergism between the two types of surfactants. The effectiveness of the mixture of surfactants was 35 % greater than that for the anionic or nonionic surfactant alone. The results indicate that mixed surfactant solution leaching is a promising candidate for the remediation of PCE contaminated sandy soil.

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Essential Oil Compounds from Agastache rugosa as Antifungal Agents Against Trichophyton Species

  • Shin, Seung-Won
    • Archives of Pharmacal Research
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    • v.27 no.3
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    • pp.295-299
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    • 2004
  • The antifungal activities of the essential oil from Agastache rugosa and its main component, estragole, combined with ketoconazole, one of the azole antibiotics commonly used to treat infections caused by Trichophyton species, were evaluated in this study. The combined effects were measured by the checkerboard microtiter and the disk diffusion tests, against T. erinacei, T. mentagrophytes, T. rubrum, T. schoenleinii and T. soudanense. Susceptibility of the five Trichophyton species to the oil alone, or ketoconazole alone, differed distinctly. The fractional inhibitory concentration indices (FICI) of ketoconazole combined with estragole or A. rugosa essential oil, against the tested Trichophyton species, were between 0.05 and 0.27, indicating synergistic effects. These drug combinations exhibited the most significant synergism against T. mentagrophytes, with FICIs of 0.05 and 0.09 for estragole and the essential oil fraction from A. rugosa, respectively. Isobolograms based on the data from checkerboard titer tests also indicated significant synergism between ketoconazole and the Agastache oil fraction or estragole, against the Trichophyton species evaluated. Trichophyton susceptibility to ketoconazole was significantly improved by combination with the Agastache rugosa oil fraction or its main component, estragole.

Activity of Essential Oil from Mentha piperita against Some Antibiotic-Resistant Streptococcus pneumoniae Strains and Its Combination Effects with Antibiotics

  • Choi, Sung-Hee;Shin, Seung-Won
    • Natural Product Sciences
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    • v.13 no.2
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    • pp.164-168
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    • 2007
  • To investigate natural antibiotics from plant essential oils and to evaluate their synergism with current antimicrobial drugs in inhibiting antibiotic-resistant strains of Streptococcus pneumoniae. The minimal inhibitory concentrations (MICs) of eleven plant essential oils and their main components were established for two antibiotic-susceptible and two antibiotic-resistant strains of S. pneumoniae, using broth microdilution tests. Potential synergism with oxacillin, norfloxacin, or erythromycin was evaluated using a checkerboard microtitre assay. Among the tested oils, Mentha piperita oil and its main component, menthol, exhibited the strongest inhibitory activities against all of the tested strains. The activity of antibiotics against antibiotic-resistant strains of S. pneumoniae was enhanced significantly by combination with Mentha piperita oils and its main component, menthol. In conclusion, the combination Mentha piperita essential oil or menthol with antibiotics could be used to reduce the effective dose of antibiotic and to modulate the resistance of S. pneumoniae strains.

Synergistic Interactions Between Chitinase ChiCW and Fungicides Against Plant Fungal Pathogens

  • Huang, Chien-Jui;Chen, Chao-Ying
    • Journal of Microbiology and Biotechnology
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    • v.18 no.4
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    • pp.784-787
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    • 2008
  • Antifungal activity of ChiCW and synergistic interactions between ChiCW with fungicides were investigated. Conidial germinations of phytopathogenic fungi, Alternaria brassicicola, Botrytis elliptica, and Colletotrichum gloeosporioides, were inhibited by ChiCW but A. longipes was not. In addition, ChiCW showed synergistic effect with fungicides Switch (cyprodinil+fludioxonil) and tebuconazole to inhibit fungal conidial germinations. The level of synergism of ChiCW with tebuconazole was higher than that with Switch. The results indicate that ChiCW may exhibit a higher level of synergism with fungicides that have a primary effect upon membranes.

Theoretical Conception of Synergistic Interactions

  • Kim, Jin-Kyu;Vladislav G. Petin
    • Korean Journal of Environmental Biology
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    • v.20 no.4
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    • pp.277-286
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    • 2002
  • An increase in the overall biological effect under the combined action of ionizing radiation with another inactivating agent can be explained in two ways. One is the supposition that synergism may attribute to a reduced cellular capacity of damn-ge repair after the combined action. The other is the hypothesis that synergism may be related to an additional lethal or potentially lethal damage that arises from the interaction of sublesions induced by both agents. These sublesions ave considered to be in-effective when each agent is applied separately. Based on this hypothesis, a simple mathematical model was established. The model can predict the greatest value of the synergistic effect, and the dependence of synergy on the intensity of agents applied, as well. This paper deals with the model validation and the peculiarity of simultaneous action of various factors with radiation on biological systems such as bacteriophage, bacterial spores, yeast and mammalian cells. The common rules of the synergism aye as follows. (1) For any constant rate of exposure, the synergy can be observed only within a certain temperature range. The temperature range which synergistically increases the effects of radiation is shifted to the lower temperature fer thermosensitive objects. Inside this range, there is a specific temperature that maximizes the synergistic effect. (2) A decrease in the exposure rate results in a decrease of this specific temperature to achieve the greatest synergy and vice versa. For a constant temperature at which the irradiation occurs, synergy can be observed within a certain dose rate range. Inside this range an optimal intensity of the physical agent may be indicated, which maximizes the synergy. As the exposure temperature reduces, the optimal intensity decreases and vice versa. (3) The recovery rate after combined action is decelerated due to an increased number of irreversible damages. The probability of recovery is independent of the exposure temperature for yeast cells irradiated with ionizing or UV radiation. Chemical inhibitors of cell recovery act through the formation of irreversible damage but not via damaging the recovery process itself.