• Journal of Radiation Protection and Research
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• 제36권1호
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• pp.1-7
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• 2011

A simple mathematical model of simultaneous combined action of environmental agents has been proposed to describe the synergistic interaction of microwave and high ambient temperature treatment on animal heating. The model suggests that the synergism is caused by the additional effective damage arising from an interaction of sublesions induced by each agent. These sublesions are considered to be ineffective if each agent is taken individually. The additional damage results in a higher body temperature increment when compared with that expected for an independent action of each agent. The model was adjusted to describe the synergistic interaction, to determine its greatest value and the condition under which it can be achieved. The prediction of the model was shown to be consistent with experimental data on rabbit heating. The model appears to be appropriate and the conclusions are valid.

• Archives of Pharmacal Research
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• 제22권3호
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• pp.232-236
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• 1999

In this study, we present evidence that cotreatment of aloesin and arbutin inhibits tyrosinase activity in a synergistic manner by acting through a different action mechanism. Aloesin or arbutin similarly inhibited enzyme activity of human- and mushroom-tyrosinases with an IC50 value of 0.1 or 0.04 mM, respectively. Lineweaver-Burk plots of the enzyme kinetics data showed that aloesin inhibited tyrosinase activity noncompetitively with a Ki value of 5.3 mM, whereas arbutin did it competitively (Maeda, 1996). We then examined whether cotreatment of these agents inhibits the tyrosinase activity in a synergistic manner. The results showed that 0.01 mM aloesin in the presence of 0.03 mM arbutin inhibited activity of mushroom by 80% of the control value and the reverse was also true. The inhibitory effects were calculated to be synergistic according to the B rgi method. Taken together, we suggest that aloesin along with arbutin inhibits in synergy melanin production by combined mechanisms of noncompetitive and competitive inhibitions of tyrosinase activity.

• 혜화의학회지
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• 제4권1호
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• pp.211-223
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• 1995

연구배경: 간암은 우리나라에서 암의 사망율 중 2위인데 한방임상에서 간암의 치료에 인진, 포공영, 시호등이 자주 사용되고 있는데 이들 한약의 간암세포에 대한 항종양효과와 간암치료에 사용되는 항암제와의 상승작용을 실험적으로 입증할 필요가 있어 실험에 착수하였다. 방법: in vitro에서 시호, 인진, 포공영 및 포공영 EE층의 인체 간암세포인 PLC(hepatoma), Hep 3B(hepatocellular carcinoma) 및 Hep G2(hepatocellular carcinoma) 등에 대한 세포독성과 간암치료에 다용되는 mitomycin C(MMC), cisplatin(CPT), 5-fluorouracil(5-FU) 등의 항암제와의 상승효과를 MTT법에 의해 측정하였다. 결과: 인진은 비교적 PLC와 Hep 3B에 대하여 항종양효과가 있고, 시호는 Hep G2에 대해 보다 효과적이고, 항암제중 MMC와의 상승적 작용이 뚜렷하여 앞으로 인진으로 부터 항암활성물질의 분리가 필요하며 한약과 항암제와의 병용투여 가능성을 제시한다고 사료된다.

• 환경생물
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• 제27권2호
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• pp.140-145
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• 2009

All organisms are being exposed to harmful factors present in the environmental. The combined action of various factors is a distinguishing feature of modern life. An interaction between two chemicals is considered as synergistic when the effect produced is greater than the sum of the two single responses. The biological effects due to the combined action of ionizing radiation with the other factor are hard to estimate and predict in advance. In the current study, we investigated the synergistic effects between ionizing and $HgCl_2$ using fish hepatoma cells (PLHC-1 cells). The results showed a dramatic decrease of cell viability after simultaneous treatment of PLHC-1 cells with ionizing radiation and $HgCl_2$. Neiither of the two had any cytotoxic effect when treated alone. The cytotoxicity of ionizing radiation was enhanced in the presence of $HgCl_2$. The synergistic effects were observed after exposure of the PLHC-1 cells to ionizing radiation combined with $HgCl_2$. The synergistic interaction was due to an increase of irreversibly damaged cells after the combined exposure. Analysis of the extent of synergistic interaction enables to make quantitative estimation of irreversibly damaged cells after the combined exposure. The present study suggests that PLHC-1 cells can serve as rapid screening tools for detecting the toxicity of harmful factors.

• 한국응용곤충학회지
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• 제28권1호
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• pp.32-36
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• 1989

Cypermethrin과 pirimicarb도태 저항성계통 복수아흑진딧물(Myzus persicae Sulzer)에 대한 acephate, cypermethrin, demeton-S-methyl, pirimicarb 상호 혼합시의 연합독작용을 검토한 결과는 다음과 같다. Cypermethrin 도태 저항성계통에 Cypermethrin+acephate, cypermethrin+demeton-S-methyl, cypermethrin_pirimicarb를 처리하였을 때, 혼합비에 따른 정도의 차이는 있었으나. 독립작용 또는 길항작용을 보였다. Pirimicarb 도태 저항성계통에 pirimicarb+acephate, pirimicarb+cypermethrin을 각각 8:2, 2:8 혼합처리하였을 때 최대의 협동결과를 보였으나, pirimicarb+demeton-S-methyl의 경웨는 혼합비에 관계없이 길항작용을 나타내었다.

• Food Science and Biotechnology
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• 제18권4호
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• pp.904-909
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• 2009

The beneficial effects derived from consuming natural antioxidants may not depend on the action of an individual antioxidant, but rather on the concerted action of several antioxidants naturally present. The aim of this study was to determine the concentrations and combinations of antioxidants that can produce synergistic effects (SyEs). Quantification of the lipoperoxyl radical scavenging capacity of antioxidants was carried out in a homogeneous model system where the free radicals were produced by the oxidation of methyl linoleate, initiated by the 2,2'-azobis (2,4-dimethylvaleronitrile). The greatest SyE (2.21, p<0.05) was seen in mixtures of all 4 antioxidants when used with concentrations of 15 ${\mu}M$ lycopene, 2.5 ${\mu}M$ vitamin E, 0.16 ${\mu}M$ vitamin C, and 10 ${\mu}M$ ${\beta}-carotene$. Doubling the vitamin E concentration from 2.5 to 5.0 ${\mu}M$ in the mixture with all 4 antioxidant reduced the SyE to 1.69 (p<0.05). Other combinations produced synergistic effects that ranged from 1.28 to 1.41.

• 미생물학회지
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• 제5권1호
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• pp.7-14
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• 1967

The synergistic actions of certain antimetabolic agents for Saccharomyces cerevisiae and Lactobacillus plantarum on radiation sterilization have been studied. The used chemical agents are sorbic acid, vitamin-$K_3$, dehydroacetic acid, p-oxybutyl benzoate and nitrofurazone, those are the permitted as food preservatives. Experimental results are as following, 1) Survival fraction of yeast which was gamma-irradiated and influenced by sorbic acid or vitamin $K_3$ is much reduced than that of only irradiated respectively. 2) It seems like that the used chemicals acts synergistically on radiation sterilization. Sodium-dehydroacetate and p-oxybutyl benzoate are proved to be also synergistic but weakly. 3) Survival fraction of Lact. plantarum which was gamma-irradiated and influenced by sorbic acid, dehydroacetic acid or nitrofurazone respectively much reduced than that of only irradiated group, it can be estimated as synergistic action of chemical affected on radiation sterilization. 4) It was found that nutrient componets can affect radiation sterilization of microorganisms protectively.

• 한국응용곤충학회지
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• 제32권2호
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• pp.176-183
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• 1993

야외계통 점박이응애에 대한 amitraz와 bifenthrin, propargite, fenbutatin oxide, dicofol을 여러 비율로 혼합하여 연합독작용을 시험한 결과, 살비제 혼합에 의한 협력작용은 살비제 조합 또는 그들의 혼합비율에 따라 큰 차이가 있었다. 모든 약제조합에서 협력작용이 나타나, amitraz와 bifenthrin의 혼합에서 2:8, amitraz와 fenbutatin oxide의 조합에서 8:2, amitraz와 propagite의 혼합에서 4:6 그리고 amitraz와 dicofol의 조합에서는 6:4의 비율에서 최대의 협력 효과를 나타내었다.

• 환경생물
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• 제20권4호
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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.

• Journal of Plant Biology
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• 제10권3_4호
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• pp.1-3
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• 1967

Observations were made on Crinum and Catharanthus pollen growth in artificial media by an ultraviolet transmission fluorescence microscope showing synergistic effect on pollen growth with calcium (Ca) and aureomycin. Bright yellow fluorescence of aureomycin enabling to trace out at tissue or cellular level did reveal that the greater accumulation of fluorescence occurred in the pollen tube wall if Ca was supplemented to the media than when aureomycin alone was present. The promotive pollen growth the media of Ca alone was further enhanced by the addtion of aureomycin. It was assumed that the promoted pollen growth with aureomycin in the Ca media was probably brought about by a supporting role of aureomycin in the Ca action.