• Title/Summary/Keyword: Biological agent

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Isolation, Identification and Biological Control Activity of SKU-78 Strain against Ralstonia solanacearum (풋마름병균, Ralstonia solanacearum의 길항세균 SKU-78 균주의 분리 동정 및 특성)

  • Sung, Pil-Je;Shin, Jeong-Kun;Cho, Hong-Bum;Kim, Shin-Duk
    • Applied Biological Chemistry
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    • v.48 no.1
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    • pp.48-52
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    • 2005
  • Six stains of plant growth promoting rhizobacteria were selected through germinating seed assay and root colonization assay. Among them, SKU-78 strain induced significant suppression of bacterial wilt disease in tomato and pepper plants. Seed treatment followed by soil drench application with this strain resulted in over 60% reduction of bacterial wilt disease compared with the control. It was suggested that SKU-78 strain activated the host defense systems in plants, based on lack of direct antibiosis against pathogen. According to Bergey's Manual of Systemic Bacteriology and 16S rDNA sequence data, SKU-78 stain was identified as Bacillus sp. SKU-78.

Biological Control of n Severe Viral Strain Using a Benign Viral Satellite RNA Associated with Cucumber mosaic virus

  • Montasser Magdy Shaban;Bader Al-Hamar;Bhardwai Radhika Guleri
    • The Plant Pathology Journal
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    • v.22 no.2
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    • pp.131-138
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    • 2006
  • Two strains of Cucumber mosaic virus (CMV) isolated in Kuwait were confirmed their infectivity based on symptomatology and host range on different cultivars of tomato (Lycopersicon esculentum), tobacco(Nicotiana tabacum L.) and squash (Cucurbita pepo). The pattern of symptoms differed for the two CMV strains in tomato and tobacco, showing severe stunting and mosaic symptoms with one strain designated KU2, and almost symptomless with the other strain designated KU1. A satellite RNA 5 (sat-RNA) was found to be associated with the KU1 strain and was characterized as a benign viral satellite RNA. Using reverse transcription and polymerase chain reaction (RT-PCR) with sat-RNA specific primers, an amplified PCR product of about 160bp was determined and analyzed by gel electrophoresis. This naturally occurring benign viral satellite RNA was successfully used as a biological control agent to protect tomato plants against the severe KU2 strain. Tomato plants grown in plant-growth chambers, were preinoculated with KU1 containing the benign viral satellite and then challenge inoculated with the severe KU2 strain at different time intervals. All plants challenged three weeks after preinoculation showed nearly complete protection from subsequent infection by the severe strain. This biological control technology using plant viruses was found protective and could be successfully established sooner after the preinoculation.

Molecular Identification of Adenocephalus pacificus (Cestoda) from Three Human Cases in Lima Province, Peru

  • Mondragon-Martinez, Aaron;Martinez-Rojas, Rosa;Garcia-Candela, Enrique;Delgado-Escalante, Abraham;Tantalean-Vidaurre, Manuel;Cruz-Neyra, Lidia
    • Parasites, Hosts and Diseases
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    • v.58 no.4
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    • pp.457-460
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    • 2020
  • The Pacific tapeworm Adenocephalus pacifcus (syn. Diphyllobothrium pacificum) is a causative agent of diphyllobothriosis occurred in Pacific coast of South America, mainly in Peru. Source of infections are traditional meal from raw or undercooked marine fish such as "cebiche". We confirmed 3 new cases, one including scolex and the other two headless. A strobila 46 cm long without scolex was discharged from an 8-year-old boy before treatment. Specimens were confirmed morphologically by presence of tegumental protuberances on proglottids and small sized eggs. Partial sequence of cytochrome c oxidase subunit 1 gene was congruent with A. pacificus sequences.

Anti-Melanogenic Activities of Ranunculus chinensis Bunge via ERK1/2-Mediated MITF Downregulation

  • Min-Jin Kim;Yong Tae Jeong;Buyng Su Hwang;Yong Hwang;Dae Won Jeong;Yeong Taek Oh
    • Korean Journal of Plant Resources
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    • v.35 no.6
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    • pp.704-712
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    • 2022
  • Research on whitening materials using natural alternatives is actively being conducted. The aim of this study was to investigate the in vitro inhibitory effects of Ranunculus chinensis Bunge (RCB) on melanogenesis and associated enzymes, such as tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 in B16F10 murine melanoma cells. We found that RCB extract significantly attenuated melanin synthesis and reduced the activity of intracellular tyrosinase, a rate-limiting melanogenic enzyme. Western blot analysis showed that RCB extract decreased the protein expression of tyrosinase and TRP-1. In addition, it significantly decreased the expression of microphthalmia-associated transcription factor (MITF), a key regulator of melanogenesis. Extracellular signal-regulated kinase (ERK) activation has been reported to be involved in the inhibition of melanogenesis. Thus, we investigated whether the hypopigmentary effects of RCB extract were related to the activation of ERK. RCB extract induced ERK phosphorylation in a dose-dependent manner. Furthermore, it markedly inhibited body pigmentation in a zebrafish model. Our results suggest that RCB extract inhibits melanogenesis by activating ERK pathway-mediated suppression of MITF and its downstream target genes, including tyrosinase. Therefore, RCB extract can be used as a whitening agent in the development of functional cosmetics.

Characteristics of Biological Agent and relavent case study (생물무기 특성과 사례연구)

  • Park, Minwoo;Kim, Hwami;Choi, Yeonhwa;Kim, Jusim
    • Journal of the Society of Disaster Information
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    • v.13 no.4
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    • pp.442-454
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    • 2017
  • Biological weapon is manipulated and produced from microorganisms such as bacteria, virus, rickettsia, fungi etc. It is classified as one of the Weapons of Mass Destruction (WMD) along with chemical weapon and radiological weapon. Biological weapon has a number of operational advantages over the other WMDs including ease of development and production, low cost and possibility of covert dissemination. In this study we analyze the history of biological weapon's development and the existing biological threats. Then, we predict the social impact of biological attack based on the physical properties of biological agent and infection mechanisms. By analyzing the recognition, dispersion pattern of agents, characteristics of the diseases in the biological weapon related historical events such as Sverdlovsk anthrax accident, 2001 anthrax attack, we found out some of the facts that biological attack would not likely to be recognized rapidly, produce large number of the exposed, increase number of paients who suffed from severe respiratory illness. It would lead the public health and medical service providers to be struggled with hugh burden. Base on the facts that we found from this case study, we suggested the main capabilities of public health required to respond to bioterrorism event efficiently. Syndromic surveillance and other reporting system need to be operated effeciently so that any suspicious event should be detected promptly. the pathogen which suspected to be used should be identified through laboratory diagnostic system. It is critical for the public health agency to define potentially exposed population under close cooperation with law enforcement agencies. Lastly, massive prophylaxis should be provided rapidly to the people at need by operating human and material resources effeciently. If those capacities of public health are consistantly fortified we would be able to deal with threat of bioterrorism successfully.

Development of a Novel Family of NSAIDs; Tripeptides

  • Park, Myung-Sook;Kieyoung Chang;Henry Rapoport
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.11a
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    • pp.147-152
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    • 1996
  • In order to discover new useful antiinflammatory agent, many new compounds are continually being synthesized and tested. A certain peptide which contains an anisolated glutamic acid has been reported to show considerable biological activities.

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Synthesis and Biological Activity of Indazole-Derived HMG-CoA Reductase Inhibitors

  • Kim, Jin-Il;Jahng, Yurng-Dong
    • Archives of Pharmacal Research
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    • v.18 no.3
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    • pp.206-212
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    • 1995
  • New hypolipaemic agents, in which substituted indazole nucleus is connected to tetrahydro-4-hydroxy-2H-pyran-2-one by a two-carbon bridge, were designed and synthesized to show significant inhibitory activity against microsomal HMG-CoA reductase in rat liver.

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Cure Properties of Novel Epoxy Resin Systems for WLP (Wafer Level Package) According to the Change of Hardeners (경화제 변화에 따른 WLP(Wafer Level Package)용 신규 Epoxy Resin System의 경화특성)

  • Kim, Whan Gun
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.2
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    • pp.57-67
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    • 2022
  • The curing characteristics of naphthalene type epoxy resin systems according to the change of curing agent were investigated to develop a new next-generation EMC(Epoxy Molding Compound) with excellent warpage characteristics, low thermal expansion, and excellent fluidity for WLP(Wafer Level Package). As epoxy resins, DGEBA, which are representative bisphenol type epoxy resins, NE-16, which are the base resins of naphthalene type epoxy resins, and NET-OH, NET-MA, and NET-Epoxy resins newly synthesized based on NE-16 were used. As a curing agent, DDM (Diamino Diphenyl Methane) and CBN resin with naphthalene moiety were used. The curing reaction characteristics of these epoxy resin systems with curing agents were analyzed through thermal analysis experiments. In terms of curing reaction mechanism, DGEBA and NET-OH resin systems follow the nth curing reaction mechanism, and NE-16, NET-MA and NET-Epoxy resin systems follow the autocatalytic curing reaction mechanism in the case of epoxy resin systems using DDM as curing agent. On the other hand, it was found that all of them showed the nth curing reaction mechanism in the case of epoxy resin systems using CBN as the curing agent. Comparing the curing reaction rate, the epoxy resin systems using CBN as the curing agent showed a faster curing reaction rate than them with DDM as a hardener in the case of DGEBA and NET-OH epoxy resin systems following the same nth curing reaction mechanism, and the epoxy resin systems with a different curing mechanism using CBN as a curing agent showed a faster curing reaction rate than DDM hardener systems except for the NE-16 epoxy resin system. These reasons were comparatively explained using the reaction rate parameters obtained through thermal analysis experiments. Based on these results, low thermal expansion, warpage reduction, and curing reaction rate in the epoxy resin systems can be improved by using CBN curing agent with a naphthalene moiety.

Purification and Identification of an Antifungal Agent from Streptomyces sp. KH-614 Antagonistic to Rice Blast Fungus, Pyricularia oryzae

  • Rhee, Ki-Hyeong
    • Journal of Microbiology and Biotechnology
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    • v.13 no.6
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    • pp.984-988
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    • 2003
  • The actinomycete strain KH-6l4 possessed strong antifungal activity, especially antagonistic to the rice blast fungus, Pyricularia oryzae. Diaminopimelic acid (DAP) type and morphological and physiological characteristics, examined by scanning electron microscopy (SEM), indicated that KH-614 belonged to the genus Streptomyces. Antifungal agent produced by this strain was found to be most active, when the strain was cultured in the presence of glucose, polypeptone, and yeast extract (PY) medium for 6 days at $27^{\circ}C$. Based on the spectral report data, MS and NMR, the antifungal agent was identified as cyclo(L-leucyl-L-prolyl). According to the antimicrobial activity test measured by minimal inhibitory concentration (MIC), the cyclo(1eu-pro) exhibited the activity against Candida albicans IAM 4905, Mucor ramannianus IAM6218, Rhizoctonia solani IFO 6218, Aspergilus fumigatus ATCC 42202, Glomerella cingulata IFO 9767, Trichophton mentagrophytes ATCC 18749, and Trichophyton rubrum ATCC 44766, the order of MIC values were 50, 12.5, 5, 50, 25, 5, $5\;\mu\textrm{g}/ml$, respectively. Specifically, cyclo(1eu-pro) was one of the most effective elements against Pyricularia oryzae IFO 5994 with the MIC value of $2.5\;\mu\textrm{g}/ml$, thus indicating that cyclo(leu-pro) is a potential antifungal agent.