• 한국수산과학회지
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• 제31권6호
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• pp.852-858
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• 1998

1996년 7월 마산만의 해수를 0.8 $\mu$m filter에 여과한 여과액과 f/2배지에서 배양한 P. micans와의 혼합배양액에서 P. micans를 사멸시키는 해양세균을 분리하였다. 분리균의 형태학적 및 생화학적 검사와 균체지방산을 분석하여 동정한 결과 Pseudomonas 속으로 동정되어 Pseudomonas sp. LG-2로 명명하였으며, 그 살조특성을 조사한 결과는 아래와 같다. Pseudomonas sp. LG-2의 개체수와 배양여과액의 농도가 높을수록 P. micans의 사멸효과가 높게 나타났다. $1.3\times10^5,\;1.3\times10^6$ cells/ml의 농도로 접종한 시험관의 P. micans는 급격히 감소하여 배양 7일 후에는 $10^2$ cells/ml 이하로 사멸되었다. 또한, 배양석과액의 최종농도가 $30\%$일 경우에는 급격히 감소하여 배양 3일 후 거의 사멸하였다. Pseudomonas sp. LG-2의 성장시기에 따른 배양여과액의 사멸효과는 잠복기의 경우 P. micans의 성장에 큰 영향을 미치지 않았으나, 대수증식기 중기의 배양여과액은 접종 5일 후 P. micans의 개체수를 1/2로 감소시켰으며, 정상기의 배양여과액은 접종 후 급격히 감소시켜 배양 3일 후 대부분 사멸시켰다. Alexandrium tamarense, Prorocentrum micans, Scrippsiella trochoidea, Gymnodinium sanguineum, Cochlodinium polykrikoides의 5종의 적조원인 편모조류에 대한 Pseudomonas sp. LG-2의 살조특이성은 P. micans와 S. trochoidea에 살조효과를 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제25권5호
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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.

• 환경위생공학
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• 제20권3호
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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

• 한국수산과학회지
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• 제29권6호
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• pp.912-913
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• 1996

• Biomolecules & Therapeutics
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• 제22권2호
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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.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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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.

• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.920-929
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• 2024

As a pivotal defensive line against multitudinous malignant tumors, natural killer (NK) cells exist in the tumor microenvironment (TME). RAD18 E3 Ubiquitin Protein Ligase (RAD18) has been reported to foster the malignant progression of multiple cancers, but its effect on NK function has not been mined. Here, the study was designed to mine the mechanism by which RAD18 regulates the killing effect of NK cells on colorectal cancer (CRC) cells. Expression of E2F Transcription Factor 7 (E2F7) and RAD18 in CRC tissues, their correlation, binding sites, and RAD18 enrichment pathway were analyzed by bioinformatics. Expression of E2F7 and RAD18 in cells was assayed by qRT-PCR and western blot. Dual-luciferase assay and chromatin immunoprecipitation (ChIP) assay verified the regulatory relationship between E2F7 and RAD18. CCK-8 assay was utilized to assay cell viability, colony formation assay to detect cell proliferation, lactate dehydrogenase (LDH) test to assay NK cell cytotoxicity, ELISA to assay levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), and immunofluorescence to detect expression of toxic molecules perforin and granzyme B. High expression of RAD18 and E2F7 was found in CRC tissues and cells. Silencing RAD18 could hamper the proliferation of CRC cells, foster viability and cytotoxicity of NK cells, and increase the secretion of GM-CSF, TNF-α, IFN-γ as well as the expression of perforin and granzyme B. Additionally, ChIP and dual-luciferase reporter assay ascertained the binding relationship between RAD18 promoter region and E2F7. E2F7 could activate the transcription of RAD18, and silencing RAD18 reversed the inhibitory effect of E2F7 overexpression on NK cell killing. This work clarified the inhibitory effect of the E2F7/RAD18 axis on NK cell killing in CRC, and proffered a new direction for immunotherapy of CRC in targeted immune microenvironment.

• Asian Pacific Journal of Cancer Prevention
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• 제13권3호
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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.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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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.

• 생명과학회지
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• 제15권4호
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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.