• 한국식품영양학회지
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• 제11권1호
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• pp.107-113
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• 1998

홍삼의 추출물인 50% ethanol extract, crude saponin, 그리고 lipid soluble fraction이 마우스 대식세포의 oxidative burst를 유발할 수 있는지 여부를 알아보고자 in vitro와 in vivo에 각각의 추출물을 처치하고 hydrogen peroxide 생산을 DCFH-DA를 이용한 형광분광광도법으로 측정하였다. 형광분광법에 의한 hydrogen peroxide의 측정을 최적화하기 위한 DCFH-DA의 농도는 3.2$mu extrm{m}$이었고, oxidative burst를 유도하기 위한 zymosan A, PNA의 최적 농도는 각각 100$\mu\textrm{g}$, 250'기호'를 사용하였다. In vitro의 경우, 홍삼의 3가지 추출물은 모두 oxidative burst를 유발하지 못하였지만, zymosan A로 유발한 경우에는 50% ethanol extract에서 가장 높은 hydrogen peroxide를 생산하였다. In vivo 실험에서는, lipid soluble extract에서만 유의하게 증가한(P<0.01) oxidative burst를 유발하였고, ginsenoside(saponin)가 어느 정도 포함되어 있는 50% ethanol extract와 crude saponin은 대조군에 배하여 유의하게 낮은(P<0.05) hydrogen peroxide를 생산하였다. 이는 ginsenoside가 마우스의 nitric oxide 생산을 억제한다는 다른 연구자들의 보고와 일치하는 결과이다. Oxidative burst를 유발한 lipid soluble extract에는 phenol계 화합물, polyactylence계 화합물, 미량성분 등이 함유되어 있으므로 차후 연구를 통하여 과연 어느 성분이 hydrogen peroxide를 증가시키는지 규명하는 것이 필요하다.

• ALGAE
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• 제27권1호
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• pp.21-32
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• 2012

We report an oxidative burst triggered by prostaglandin $A_2(PGA_2)$ in the brown algal kelp Laminaria digitata, constituting the first such discovery in an alga and the second finding of an oxidative burst triggered by a prostaglandin in a living organism. The response is more powerful than the oxidative burst triggered by most other chemical elicitors in Laminaria. Also, it is dose-dependent and cannot be inhibited by diphenylene iodonium, suggesting that another source than NAD(P)H oxidase is operational in the production of reactive oxygen species. Despite the very strong oxidative response, rather few effects at other levels of signal transduction pathways could be identified. $PGA_2$ does not increase lipolysis (free fatty acids) in Laminaria, and only one oxylipin (15-hydroxyeicosatetraenoic acid; 15-HETE) was found to be upregulated in Laminaria. In a subsequent set of experiments in the genome model Ectocarpus siliculosus, none of 5 selected candidate genes, all established participants in various stress responses, showed any significant differences in their expression profiles.

• BLOOD RESEARCH
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• 제53권4호
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• pp.299-306
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• 2018

Background IgG-mediated anaphylaxis occurs after infusion of certain monoclonal antibody-based therapeutics. New in vitro tests are urgently needed to diagnose such reactions. We investigated whether allergens trigger neutrophil oxidative burst (OB) and if neutrophil OB occurs due to allergen-specific IgG (sIgG). Methods Neutrophil OB was measured by dihydrorhodamine 123 flow cytometry using a leukocyte suspension spiked with a very small patch of the allergen crude extract, Dermatophagoides farinae (Der f). The mean fluorescence intensity ratio of stimulated to unstimulated samples was calculated as the neutrophil oxidative index (NOI). Results The Der f-specific NOI (Der f-sNOI) showed a time-dependent increase after Der f extract addition. At 15 min activation, higher Der f-sIgG levels were associated with lower Der f-sNOI values in 31 subjects (P<0.05). This inverse relationship occurs due to the initial blocking effect of free Der f-sIgG. Additionally, neutrophil OB was nearly absent (Der f-sNOI of -1) in two cases: a subject with undetectable Der f-sIgG levels and washed leukocyte suspensions deprived of Der f-sIgG. Conclusion Allergens can trigger neutrophil OB via preexisting allergen-sIgG. Neutrophil OB can be easily measured in a leukocyte suspension spiked with the allergen. This assay can be used to diagnose IgG-mediated anaphylaxis.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.64.1-64
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• 2003

Inoculation of primary pepper leaves with an avirulent strain of Xanthomonas campestris pv. vesicatoria induced systemic acquired resistance (SAR) in secondary leaves. This SAR response was accompanied by the systemic expression of defense-related genes, a systemic microoxidative burst generating H2O2, and the systemic induction of ion-leakage and callose deposition in the non-inoculated, secondary leaves. Some defense-related genes encoding PR-1, chitinase, peroxidase, PR10, thionin, defensin and zinc-finger protein were distiilctly induced in the systemic leaves. The systemically striking accumulation of H$_2$O$_2$and strong increase in peroxidase activity in pepper was suggested to contribute to the triggering of cell death In the systemic micro-HRs, leading to the induction of SAR. Treatment of non-inoculated, secondary leaves with diphenylene iodinium (DPI), an inhibitor of the oxidative burst, substantially reduced the induction of some defense-related genes and subsequently SAR.

• 한국임상수의학회지
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• 제21권3호
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• pp.236-242
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• 2004

1,2-benzopyrone can stimulate macrophages to increase the ability of phagocytosis. Peripheral blood polymorphonuclear cells (PMN) and macrophages destroy microbial organisms with reactive oxygen species (ROS), called oxidative burst activity (OBA). This study was undertaken to determine whether 1,2-benzopyrone affects the OBA on the phagocytic response of canine peripheral blood phagocytes. The OBA of phagocytes in the addition or absence of latex beads was analyzed by flow cytometry system using dihydrorhodamine 123 (DHR). The direct treatments of 1,2-benzopyrone have no effect on the OBA of peripheral blood mononuclear cells (PBMC), PMN and monocyte-rich cells regardless of addition of latex beads. When latex beads are added to PMN, the OBA of PMN was remarkably enhanced by culture supernatant from PBMC but not PMN treated with 1,2-benzopyrone. Similary, it was also enhanced by human recombinant (hr) $TNF-\alpha.$ However, when latex beads were not added to PMN, its OBA was not enhanced by culture supernatant from either PBMC or PMN treated with 1,2-benzopyrone. The OBA of latex beads-phagocytized PBMC and monocyte-rich cells was not enhanced by culture supernatant from either PBMC or PMN treated with 1,2-benzopyrone. These results strongly suggested that 1,2-benzopyrone has an immunoenhancing effect on the OBA of PMN when phagocytic response occurred only. This enhanced OBA may be mediated through active humoral substance(s), such as $TNF-\alpha,$ produced by PBMC stimulated with 1,2-benzopyrone.

• The Plant Pathology Journal
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• 제21권3호
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• pp.283-287
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• 2005

Since the discovery of generation of $O_2^-$ in plant, many evidence for the oxidative burst (OXB) has been accumulated in various combinations of plant and pathogen or elicitor systems. $O_2^-$ generating system responsible for the OXB was coupled with oxidation of reduced nicotinamide adenine dinucleotide phosphate (NADPH) in microsomal fraction isolated from sliced aged potato tuber slices which were treated by hyphal wall components elicitor from Phytophthora infestans (HWC). We developed new assay method for quantitative measurement of oxygen radical $O_2^-$ by using electron spin resonance (ESR) analysis during elicitor­induced OXB on the surface of plant tissues. The ESR analysis using an $O_2^-$ trapper, Tiron (1,2-dihydroxy-3,5­benzenedisulfonic acid), provided a convenient assay for detecting only $O_2^-$ during elicitor-induced OXB producing various active oxygen species (AOS) on plant tissue surface. Tiron was oxidized to Tiron semiquinon radical by $O_2^-$. Quantity of the radical signal was measured by specific spectra on ESR spectroscopy. The level of $O_2^-$ was high in from surface of potato tuber tissue treated with hyphal cell wall elicitor (HWC) from Phytophthora infestans. There was no secondary OXB induction by $H_2O_2$ treatment in plant.

• Molecules and Cells
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• 제28권4호
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• pp.321-329
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• 2009

Rapid production of nitric oxide (NO) and reactive oxygen species (ROS) has been implicated in the regulation of innate immunity in plants. A potato calcium-dependent protein kinase (StCDPK5) activates an NADPH oxidase StRBOHA to D by direct phosphorylation of N-terminal regions, and heterologous expression of StCDPK5 and StRBOHs in Nicotiana benthamiana results in oxidative burst. The transgenic potato plants that carry a constitutively active StCDPK5 driven by a pathogen-inducible promoter of the potato showed high resistance to late blight pathogen Phytophthora infestans accompanied by HR-like cell death and $H_2O_2$ accumulation in the attacked cells. In contrast, these plants showed high susceptibility to early blight necrotrophic pathogen Alternaria solani, suggesting that oxidative burst confers high resistance to biotrophic pathogen, but high susceptibility to necrotrophic pathogen. NO and ROS synergistically function in defense responses. Two MAPK cascades, MEK2-SIPK and cytokinesis-related MEK1-NTF6, are involved in the induction of NbRBOHB gene in N. benthamiana. On the other hand, NO burst is regulated by the MEK2-SIPK cascade. Conditional activation of SIPK in potato plants induces oxidative and NO bursts, and confers resistance to both biotrophic and necrotrophic pathogens, indicating the plants may have obtained during evolution the signaling pathway which regulates both NO and ROS production to adapt to wide-spectrum pathogens.

• Tuberculosis and Respiratory Diseases
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• 제48권2호
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• pp.246-259
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• 2000

연구배경: 패혈증에 의해 발병하는 ARDS의 기전은 아직까지 명확히 알려져 있지 않다. 특히 패혈증시 폐 혈관내피세포 및 제 1, 2형 폐포세포의 손상이 호중구의 respiratory burst에 따른 oxidative stress에 의한 것인지는 아직도 논란의 대상이다. 또한 이때 oxidative stress의 직접적인 원인인 산소기 생성기전도 명확하지가 않다. 본 연구에서는 패혈증에 의한 ARDS 발병기전을 $PLA_2$의 작용과 호중구의 산소기 생성을 연관시켜 알아보고자 하였다. 방 법: Sprague-Dawley종 흰쥐에서 diethylmaleate(DEM)를 이용하여 glutathione을 고갈시킨 뒤 내독소를 기도 내로 분무하여 급성 폐손상을 유발하였다. 이때 oxidative stress를 평가할 수 있는 방법들, 즉 단백누출지수, 폐세척액 내 단백함량, 폐장 내 myelo-peroxidase(MPO)의 활동도 malondialdehyde(MDA)의 측정 및 GGT의 활성도를 측정하고 동시에 oxidative stress에 관여하는 $PLA_2$의 역할을 확인하기 위하여 비특이적 $PLA_2$ 억제제인 mepacrine(50mg/kg)을 복강 내 투여한 후 폐장 내 $PLA_2$의 활성도를 측정하였다. 또한 미세구조적 변화 및 세포화학적인 방법을 통해 조직 내 산소기의 생성을 확인, 비교하여 산소기 형성에 관여하는 $PLA_2$의 역할을 규명하였다. 결 과: Diethylmaleate에 의해 폐장 내 glutathione을 고갈시킨 뒤 내독소를 투여한 흰쥐에서, 내독소는 폐장 내 현저한 조직의 손상을 유발하였고, 동시에 oxidative stress의 증가를 관찰하였다. 즉 lipid peroxidation의 증가 및 GGT 활성도의 증가를 관찰하였다. 이러한 변화들은 폐장 내 호중구 침윤의 증가 및 $PLA_2$ 활성도와 관계가 있음을 확인하였고, 미세구조적 및 세포화학적인 방법으로 조직 내의 산소기 형성의 증가도 관찰하였다. 이러한 변화들이 비특이적 $PLA_2$ 억제제인 mepacrine의 작용에 의해 감소하는 것으로 미루어 보아 $PLA_2$가 내독소에 의한 oxidative stress에 관여한다고 생각되었다. 결 론: 내독소에 의해 유발되는 급성 폐손상에서 조직손상의 원인은 호중구의 respiratory burst에 따른 oxidative stress임을 확인하였고 이때 oxidative stress에 $PLA_2$의 활성화에 따라 생성되는 지질분자가 그 원인으로 사료되었다.

• Molecules and Cells
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• 제39권5호
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• pp.426-438
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• 2016

Plant disease resistance occurs as a hypersensitive response (HR) at the site of attempted pathogen invasion. This specific event is initiated in response to recognition of pathogen-associated molecular pattern (PAMP) and subsequent PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). Both PTI and ETI mechanisms are tightly connected with reactive oxygen species (ROS) production and disease resistance that involves distinct biphasic ROS production as one of its pivotal plant immune responses. This unique oxidative burst is strongly dependent on the resistant cultivars because a monophasic ROS burst is a hallmark of the susceptible cultivars. However, the cause of the differential ROS burst remains unknown. In the study here, we revealed the plausible underlying mechanism of the differential ROS burst through functional understanding of the Magnaporthe oryzae (M. oryzae) AVR effector, AVR-Pii. We performed yeast two-hybrid (Y2H) screening using AVR-Pii as bait and isolated rice NADP-malic enzyme2 (Os-NADP-ME2) as the rice target protein. To our surprise, deletion of the rice Os-NADP-ME2 gene in a resistant rice cultivar disrupted innate immunity against the rice blast fungus. Malic enzyme activity and inhibition studies demonstrated that AVR-Pii proteins specifically inhibit in vitro NADP-ME activity. Overall, we demonstrate that rice blast fungus, M. oryzae attenuates the host ROS burst via AVR-Pii-mediated inhibition of Os-NADP-ME2, which is indispensable in ROS metabolism for the innate immunity of rice. This characterization of the regulation of the host oxidative burst will help to elucidate how the products of AVR genes function associated with virulence of the pathogen.

• Tuberculosis and Respiratory Diseases
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• 제51권6호
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• pp.503-516
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• 2001

연구배경 : 급성 출혈성 쇼크에서 발생하는 급성폐손상의 병인론을 호중구의 산소기 생성과 연관하여 규명하고자 본 연구를 시행하였다. 급성출혈성쇼크에서 폐장내 산소기 생성의 주된 원인이 호중구의 침윤에 의한 것이며 이 때 PLA2의 활성화가호중구의 respiratory burst의 직접적인 원인임올 밝히고지 하였다. 방 법 : 체중 300-350 g 정도의 흰쥐에서 체중/kg 당 20ml정도의 혈액을 5분 동안 뽑아내어 급성 출혈성 쇼크를 유발하고 이 출혈성 쇼크 상태를 1시간 동안 유지하였다. 그 후 급성 폐손상의 지표들을 측정하였다. 동시에 폐장의 미세구조의 변화 및 세포화학적인 검사를 통하여 폐장조직내의 산소기의 형성을 확인하였다. 또한 PLA2 억제제인 mepacrine을 출혈직전에 투여하여 PLA2의 억제에 따른 변화도 검사, 비교하였다. 결 과 : 급성 출혈성 쇼크에 의해 유도된 급성 폐손상에서 호중구의 폐장내 침윤이 확인되었고 이 때 폐부종 및 조직내 산소기 형성의 증가가 관찰되었으며, 폐장내 PLA2의 활성도도 증가하였다. 그러나 mepacrine을 이용하여 PLA2를 억제한 결과, 폐부종의 감소, 산소기 형성의 감소가 확인되었다. 결 론 : 급성 출혈성 쇼크에 의한 급성폐손상은 호중구에 의한 산화성스트레스가 그 원인으로 생각되고 이 때 호중구에 의한 산화성스트레스의 발생에는 PLA2가 주된 역할을 한다고 사료된다.