• Title/Summary/Keyword: killing effect

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Isolation of Marine Bacteria Killing Red Tide Microalgae II. Isolation and Algicidal Properties of Pseudomonas sp. LG-2 Possessing Killing Activity for Dinoflagellate, Prorocentrum micans (적조생물 살조세균 탐색 II. 적조생물 Prorocentrum micans 살조세균 Pseudomonas sp. LG-2의 분리와 살조특성)

  • LEE Won-Jae;PARK Young-Tae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.6
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    • pp.852-858
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    • 1998
  • We have isolated a bacterial strain that tends to kill P. micans from the mixed culture of p. minns plus seawater filtrate (poresize, 0.8 $\mu$m) collected at Masan bay in July 1996, in which the mixed culture grown in the f/2 medium. According to the experimental results of the isolated bacterium such as fatty acids analysis, morphological and biochemical characteristic tests, the strain was supposed to be a Pseudomonas and then it was named as Pseudomonas sp. LG-2. The killing effect of Pseudomonas sp. LG-2 against P. micans was proportionally increased with the concentrations of culture filtrate (pore size, 0.8 $\mu$m) is well as with the number of bacterium inoculated. In the mixed culture inoculated with $1.3\times10^6$ cells/ml of Pseudomonas sp. LG-2, the number of P. micans (2,000 cells/ml) was gradually decreased and then killed below 100 cells/ml within 7 days. In addition, the culture filtrate with $30\%$ of final concentration revealed a significant killing effect against P. micans around 3 days after culture. In the relationship between killing effects and growth stage of Pseudomonas sp. LG-2, the culture filtrate at lag phase has little effects on P. micans. In constant, the culture filtrate at mid-log phase showed the killing effect by decreasing P. micans to 112 in number within 5 days. In particular, the culture filtrate at stationary phase showed a significant killing effect against P. micans in which the majority of it was killed after 3 day culture. The species specificity of killing effects of Pseudomonas sp. LG-2 against 5 species of dinoflagellate was only found in P. micans and Scrippsiella trochoidea.

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Ursolic Acid Activates Intracellular Killing Effect of Macrophages During Mycobacterium tuberculosis Infection

  • Podder, Biswajit;Jang, Woong Sik;Nam, Kung-Woo;Lee, Byung-Eui;Song, Ho-Yeon
    • Journal of Microbiology and Biotechnology
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    • v.25 no.5
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    • pp.738-744
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    • 2015
  • Tuberculosis is one of the most threatening infectious diseases to public health all over the world, for which Mycobacterium tuberculosis (MTB) is the etiological agent of pathogenesis. Ursolic acid (UA) has immunomodulatory function and exhibits antimycobacterial activity. However, the intracellular killing effect of UA has yet to be elucidated. The aim of this study was to evaluate the intracellular killing effect of UA during mycobacterial infection. The intracellular killing activity of UA was evaluated in the macrophage cell line THP-1 by the MGIT 960 system as well as by CFU count. The production of reactive oxygen species (ROS) and the level of nitric oxide (NO) were measured using DCF-DA and Griess reagent, respectively. Phagocytosis was observed by a fluorescence-based staining method, and the colony forming units were enumerated on 7H11 agar medium following infection. In addition, MRP8 mRNA expression was measured by qRT-PCR. UA significantly decreased the number of intracellular Mycobacterium through generation of ROS and NO. In addition, it profoundly activated the phagocytosis process of THP-1 cells during MTB-infection. Furthermore, our data demonstrated that UA activated the phagocytosis process in human monocyte cells through MRP8 induction. These data suggest that UA firmly contributes to the intracellular killing effect of macrophages during mycobacterial infection.

Studies on the Susceptibility of Insecticides and Killing Effect by Thermal Fogging Against Culex pipiens pallens of Ansan Strain (안산시 서식 빨간집모기(Culex pipiens pallens)에 대한 살충제 감수성 및 가열연막 효과에 관한 연구)

  • Choi Han-Young
    • Journal of environmental and Sanitary engineering
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    • v.20 no.3 s.57
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    • pp.44-50
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    • 2005
  • Studies on the insecticides susceptibility of adults females Culex pipiens pallens were carried out in 2003. The pupae were emerged originated wild-caught larvae in Ansan city, Korea. The test methods employed, using 7 organophosphorous insecticides, four synthetic pyrethroides, and fipronil penyrazole were evaluated. The following results were obtained 1. Fipronil has showed the most strong value in $LD_{50}\;0.00075{\mu}g/female$, out of 12 kind of insecticides, and followed by deltamethrin 0.0071, $\delta-cyhalothrin\;0.008$, profenofos 0.0082 and $\beta-cyfluthrin$ 0.0088, respectively 2. The killing effect of lambdacyhalothrin and profenophos against adult females Culex pipiens pallens was examined using thermal fogging. The mortality rate were lambdacyhalothrin $41.1\%$ and profenophos $50.7\%$, respectively. The killing effect of thermal fogging was highly effectiveness to distance 6m from nozzle

Vesicular Stomatitis Virus G Glycoprotein and ATRA Enhanced Bystander Killing of Chemoresistant Leukemic Cells by Herpes Simplex Virus Thymidine Kinase/Ganciclovir

  • Hu, Chenxi;Chen, Zheng;Zhao, Wenjun;Wei, Lirong;Zheng, Yanwen;He, Chao;Zeng, Yan;Yin, Bin
    • Biomolecules & Therapeutics
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    • v.22 no.2
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    • pp.114-121
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    • 2014
  • Refractoriness of acute myeloid leukemia (AML) cells to chemotherapeutics represents a major clinical barrier. Suicide gene therapy for cancer has been attractive but with limited clinical efficacy. In this study, we investigated the potential application of herpes simplex virus thymidine kinase/ganciclovir (HSV-TK/GCV) based system to inhibit chemoresistant AML cells. We first generated Ara-C resistant K562 cells and doxorubicin-resistant THP-1 cells. We found that the HSV-TK/GCV anticancer system suppressed drug resistant leukemic cells in culture. Chemoresistant AML cell lines displayed similar sensitivity to HSV-TK/GCV. Moreover, HSV-TK/GCV killing of leukemic cells was augmented to a mild but significant extent by all-trans retinoic acid (ATRA) with concomitant upregulation of Connexin 43, a major component of gap junctions. Interestingly, HSV-TK/GCV killing was enhanced by expression of vesicular stomatitis virus G glycoprotein (VSV-G), a fusogenic membrane protein, which also increased leukemic cell fusion. Co-culture resistant cells expressing HSV-TK and cells stably transduced with VSV-G showed that expression of VSV-G could promote the bystander killing effect of HSV-TK/GCV. Furthermore, combination of HSV-TK/GCV with VSV-G plus ATRA produced more pronounced antileukemia effect. These results suggest that the HSV-TK/GCV system in combination with fusogenic membrane proteins and/or ATRA could provide a strategy to mitigate the chemoresistance of AML.

Enhancement of Nitric Oxide with nonthermal plasma jet and its effect on Escherichia coli inactivation and various type of cancer cell

  • Shaw, Priyanka;Kumar, Naresh;Attri, Pankaj;Choi, Eun Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.230.2-230.2
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    • 2016
  • A new approach for antimicrobial is based on the overproduction of reactive nitrogen species (RNS), especially; nitric oxide (NO) and peroxinitrite ($ONOO^-$-) are important factors to deactivate the bacteria. Recently, non-thermal atmospheric pressure plasma jet (APPJ) has been frequently used in the field of microbial sterilization through the generation of different kinds of RNS/ROS species. However, in previous study we showed APPJ has combine effects ROS/RNS on bacterial sterilization. It is not still clear whether this bacterial killing effect has been done through ROS or RNS. We need to further investigate separate effect of ROS and RNS on bacterial sterilization. Hence, in this work, we have enhanced NO production, especially; by applying a 1% of HNO3 vapour to the N2 based APPJ. In comparison with nitrogen plasma with inclusion of water vapour plasma, it has been shown that nitrogen plasma with inclusion of 1% of HNO3 vapour has higher efficiency in killing the E. coli and different type of cancer cell through the high production of NO. We also investigate the enhancement of NO species both in atmosphere by emission spectrum and inside the solution by ultraviolet absorption spectroscopy. Moreover, qPCR analysis of oxidative stress mRNA shows higher gene expression. It is noted that 1% of HNO3 vapour plasma generates high amount of NO for killing bacteria and cancer cell killing.

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Killing Effects of Different Physical Factors on Extracorporeal HepG2 Human Hepatoma Cells

  • Zhang, Kun-Song;Zhou, Qi;Wang, Ya-Feng;Liang, Li-Jian
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.3
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    • pp.1025-1029
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    • 2012
  • Objective: To determine the killing effects on extracorporeal HepG2 cells under different temperatures, pressures of permeability and lengths of treatment time. Method: According to different temperatures, pressures of permeability and lengths of treating time, extracorporeal HepG2 cells of human hepatoma cell-line were grouped to 80 groups. Cell index (CI) as the measurement of killing effect were calculated by monotetrazolium (MTT) methods, i.e., CI =1- (the OD value in treated group - the OD value in blank control group) / (mean of untreated control group - mean of blank control group). According to the factorial design, data were fed into SPSS 10.0 and analyzed by three-way ANOVA (analysis of variance). Result: Temperature, pressure of permeability and length of treating time all had effects on the CI (cell index) level. Length of treating time was the most influential factor of the three. Additionally, any two of them all had statistically significant interactive effects on the CI level. When treated for 5-30 min, destilled water at $46^{\circ}C$ stably generated the highest CI. Conclusion: The "$46^{\circ}C$-destilled water-60 min" was considered as the optimal combination of conditions which lead to highest CI. We suggest exerting celiac lavage for 15 min with stilled water at $40^{\circ}C-43^{\circ}C$ in surgical practice as a hyperthermia treatment to achieve ideal killing effects on free cancer cells, which is feasible, practical, and clinically effective.

Enhancement of Nitric Oxide with nonthermal plasma jet and its effect on Escherichia coli inactivation

  • Shaw, Priyanka;Kumar, Naresh;Attri, Pankaj;Kwak, Hyong Sin;Choi, Eun Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.159-159
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    • 2015
  • A new approach for antimicrobial is based on the overproduction of reactive nitrogen species (RNS), especially; nitric oxide (NO) and peroxinitrite (ONOO-) are important factors to deactivate the bacteria. Recently, non-thermal atmospheric pressure plasma jet (APPJ) has been frequently used in the field of microbial sterilization through the generation of different kinds of RNS/ROS species. However, in previous study we showed APPJ has combine effects ROS/RNS on bacterial sterilization. It is not still clear whether this bacterial killing effect has been done through ROS or RNS. We need to further investigate separate effect of ROS and RNS on bacterial sterilization. Hence, in this work, we have enhanced NO production, especially; by applying a 1% of HNO3 vapour to the N2 based APPJ. In comparison with nitrogen plasma with inclusion of water vapour plasma, it has been shown that nitrogen plasma with inclusion of 1% of HNO3 vapour has higher efficiency in killing the E. coli through the high production of NO. We also investigate the enhancement of NO species both in atmosphere by emission spectrum and inside the solution by ultraviolet absorption spectroscopy. Moreover, qPCR analysis of oxidative stress mRNA shows higher gene expression. It is noted that 1% of HNO3 vapour plasma generates high amount of NO for killing bacteria.

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The Effects of Ammonium Ion and Salts on the Killing of Red Tides Organism; Cochlodinium polykrikoides and Gymnodinium sanguieum (적조생물, Cochlodinium polykrikoides와 Gymnodinium sanguieum의 사멸에 있어 암모니아염의 효과)

  • Sohn, Jae-Hak
    • Journal of Life Science
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    • v.15 no.4 s.71
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    • pp.578-583
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    • 2005
  • Cell-free culture broth of marine halophilic bacterium, Kordia algicida was shown to possess specific algicidal ability against red tide organism, Cochlodinium polykrikides. Physiochemical characteristics of algicidal material originated in the bacterial culture broth were analyzed that its molecular weight was estimated to a 3,000 dalton and it was stable in heat and pH treatment. The algicidal fraction against C. polykrikoides obtained from gel permeable chromatography contained high concentration of ammonium ion as analyzed by ICP/Mass spectrum. C. polykrikoides by the fraction was quickly lysed within 1 min. It was shown that the effective concentration for algicide against C. polykrikoides was over 1mM of ammonium chloride. On the other hand, other metal ions presented in the algicidal fraction showed no algicidal effect against C. polykrikoides. In additon, ammonium ion exhibited species-specific killing spectrum for two species of red tide organisms, C. polykrikoides and Gymnodinium sanguieum. Therefore, further researches on the killing mechanism against C. polykrikoides exerted by ammonium ion, and subsequent development of replaceable algicidal materials will perform to provide useful tools for the control of red tide.

A Review on Experimental Research about Anticancer Drug Combined Treatment with Herbal Medicine for Killing or Inhibiting Proliferation of Cancer cells in Korea. (항암제와 한약재의 병용투여 시 암세포 증식억제 효과에 대한 국내 실험연구 문헌고찰)

  • Lee, Ji Eun;Choi, Jin Yong;Han, Chang Woo;Choi, Jun Yong;Park, Seong Ha;Kim, So Yeon
    • Herbal Formula Science
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    • v.25 no.3
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    • pp.391-412
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    • 2017
  • Objective : In this study, we searched the experimental research about combined treatment of anticancer drug and herbal medicine for killing or inhibiting proliferation of Cancer cells searched in OASIS and KISS. This study aimed to analyze the experimental research paper about anticancer drug combined treatment with herbal medicine. Methods : We collected the research paper including killing or inhibiting proliferation of Cancer cells in OASIS and KISS using keyword anticancer drug with herbal medicine, tumor suppressor with herbal medicine, inhibition of Cancer with herbal medicine and combined treatment with herbal medicine. Assorting by cancer cells, we analyzed experimental results cancer cell viability, anticancer drug dosage, tumor weight and survival rate. Also, we checked the effects of herbal medicine on cancer and additive effect reducing side effect of anticancer drug. Results : Total 45 studies were selected. 38 studies reported combined treatment of anticancer drug and herbal medicine was more effective than only anticancer drug. The death of cancer cells was synergistically induced by the cotreatment of anticancer drug and herb extracts. The studies suggest that the cotreatment of anticancer drug and herb extracts could reduce side effect of anticancer drug. In addition, some studies reported cotreatment mechanism like apoptotic death signal processes. In combined treatment of anticancer drug and herb extracts, The expression of Fas/Fas L, Bax, Bcl2, Caspase-3 etc.. was markedly increased in cancer cells. Conclusions : Our results suggest that anticancer drug combined treatment with herbal medicine could be efficient for killing or inhibiting proliferation of cancer cells. However, this paper had some limitation as follows: First, collected studies have been published only for korean journal. Second, results of research and effects of combined treatment are not collected objectively. To solve these problems, more objective and balanced studies should be performed.