• Title/Summary/Keyword: Infection biology

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Metformin ameliorates bile duct ligation-induced acute hepatic injury via regulation of ER stress

  • Lee, Chi-Ho;Han, Jung-Hwa;Kim, Sujin;Lee, Heejung;Kim, Suji;Nam, Dae-Hwan;Cho, Du-Hyong;Woo, Chang-Hoon
    • BMB Reports
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    • v.53 no.6
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    • pp.311-316
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    • 2020
  • Cholestasis is a condition in which the bile duct becomes narrowed or clogged by a variety of factors and bile acid is not released smoothly. Bile acid-induced liver injury is facilitated by necrotic cell death, neutrophil infiltration, and inflammation. Metformin, the first-line treatment for type 2 diabetes, is known to reduce not only blood glucose but also inflammatory responses. In this study, we investigated the effects of metformin on liver injury caused by cholestasis with bile acid-induced hepatocyte injury. Static bile acid-induced liver injury is thought to be related to endoplasmic reticulum (ER) stress, inflammatory response, and chemokine expression. Metformin treatment reduced liver injury caused by bile acid, and it suppressed ER stress, inflammation, chemokine expression, and neutrophil infiltration. Similar results were obtained in mouse primary hepatocytes exposed to bile acid. Hepatocytes treated with tauroursodeoxycholic acid, an ER stress inhibitor, showed inhibition of ER stress, as well as reduced levels of inflammation and cell death. These results suggest that metformin may protect against liver injury by suppressing ER stress and inflammation and reducing chemokine expression.

Effect of Metals on Tobacco Mosaic Virus Infection (담배모자이크 바이러스 감염성에 대한 금속의 영향)

  • Choi, C.W
    • The Journal of Natural Sciences
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    • v.10 no.1
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    • pp.23-26
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    • 1998
  • The efficacy of various concentration of divalent copper and zinc ions was evaluated separately for the infectivity of tobacco mosaic virus. Infectivity of TMV was more enhanced by addition of zinc, while it was decreased by addition of copper. The number of local lesions were more produced on tobacco leaves inoculated with inoculum sap containing zinc than those inoculated with sap only. The effect of copper inhibited the infectivity of TMV is dependent on copper concentration. TMV particles treated with various concentration of zinc and copper, respectively, analyzed by electrophoresis, and appeared to be altered in electrophoretic behavior. When TMV was exposed to zinc concentration at more than 200mM, the viral particles were completely degraded, and at 40-20 mM they were barely detectable, but at 2 mM they were quite stable. When TMV was exposed at less than concentration of 20 mM of copper were degraded.

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Oxymatrine Causes Hepatotoxicity by Promoting the Phosphorylation of JNK and Induction of Endoplasmic Reticulum Stress Mediated by ROS in LO2 Cells

  • Gu, Li-li;Shen, Zhe-lun;Li, Yang-Lei;Bao, Yi-Qi;Lu, Hong
    • Molecules and Cells
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    • v.41 no.5
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    • pp.401-412
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    • 2018
  • Oxymatrine (OMT) often used in treatment for chronic hepatitis B virus infection in clinic. However, OMT-induced liver injury has been reported. In this study, we aim to investigate the possible mechanism of OMT-induced hepatotoxicity in human normal liver cells (L02). Exposed cells to OMT, the cell viability was decreased and apoptosis rate increased, the intracellular markers of oxidative stress were changed. Simultaneously, OMT altered apoptotic related proteins levels, including Bcl-2, Bax and pro-caspase-8/-9/-3. In addition, OMT enhanced the protein levels of endoplasmic reticulum (ER) stress makers (GRP78/Bip, CHOP, and cleaved-Caspase-4) and phosphorylation of c-Jun N-terminal kinase (p-JNK), as well as the mRNA levels of GRP78/Bip, CHOP, caspase-4, and ER stress sensors (IREI, ATF6, and PERK). Pre-treatment with Z-VAD-fmk, JNK inhibitor SP600125 and N-acetyl-l-cysteine (NAC), a ROS scavenger, partly improved the survival rates and restored OMT-induced cellular damage, and reduced caspase-3 cleavage. SP600125 or NAC reduced OMT-induced p-JNK and NAC significantly lowered caspase-4. Furthermore, 4-PBA, the ER stress inhibitor, weakened inhibitory effect of OMT on cells, on the contrary, TM worsen. 4-PBA also reduced the levels of p-JNK and cleaved-caspase-3 proteins. Therefore, OMT-induced injury in L02 cells was related to ROS mediated p-JNK and ER stress induction. Antioxidant, by inhibition of p-JNK or ER stress, may be a feasible method to alleviate OMT-induced liver injury.

Biochemical Quantitation of PM2 Phage DNA as a Substrate for Endonuclease Assay

  • Joo, Yoo-Jin;Kim, Hee-Ju;Lee, Jae-Yung;Kim, Joon
    • Journal of Microbiology
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    • v.42 no.2
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    • pp.99-102
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    • 2004
  • Bacteriophage PM2 has a closed circular form of double stranded DNA as a genome. This DNA from the phage is a useful source for nick-circle endonuclease assay in the fmol range. Due to difficulties in the maintenance of viral infectivity, storage conditions of the phage should be considered for the puri-fication of PM2 DNA. The proper condition for a short-term storage of less than 2 months is to keep the PM2 phage at 4$^{\circ}C$; whereas the proper condition for a long-term storage of the PM2 phage for over 2 months is to keep it under liquid nitrogen in 7.5 % glycerol. The optimal conditions for a high yield of phage progeny were also considered with the goal to achieve a successful PM2 DNA preparation. A MOI(Multiplicity Of Infection) of 0.03, in which the OD$\sub$600/ of the host bacteria was between 0.3 and 0.5, turned out to be optimal for the mass production of PM2 phage with a burst size of about 214. Considerations of PM2 genome size, and the concentrations and radiospecific activities of purified PM2 DNA, are required to measure the endonuclease activity in the fmol range. This study reports the proper quantitation of radioactivity and the yield of purified DNA based on these conditions.

Cordycepin Suppresses Expression of Diabetes Regulating Genes by Inhibition of Lipopolysaccharide-induced Inflammation in Macrophages

  • Shin, Seul-Mee;Lee, Sung-Won;Kwon, Jeong-Hak;Moon, Sun-Hee;Lee, Seung-Jeong;Lee, Chong-Kil;Cho, Kyung-Hae;Ha, Nam-Joo;Kim, Kyung-Jae
    • IMMUNE NETWORK
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    • v.9 no.3
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    • pp.98-105
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    • 2009
  • Background: It has been recently noticed that type 2 diabetes (T2D), one of the most common metabolic diseases, causes a chronic low-grade inflammation and activation of the innate immune system that are closely involved in the pathogenesis of T2D. Cordyceps militaris, a traditional medicinal mushroom, produces a component compound, cordycepin (3'-deoxyadenosine). Cordycepin has been known to have many pharmacological activities including immunological stimulating, anti-cancer, and anti-infection activities. The molecular mechanisms of cordycepin in T2D are not clear. In the present study, we tested the role of cordycepin on the anti-diabetic effect and anti-inflammatory cascades in LPS-stimulated RAW 264.7 cells. Methods: We confirmed the levels of diabetes regulating genes mRNA and protein of cytokines through RT-PCR and western blot analysis and followed by FACS analysis for the surface molecules. Results: Cordycepin inhibited the production of NO and pro-inflammatory cytokines such as IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ in LPS-activated macrophages via suppressing protein expression of pro-inflammatory mediators. T2D regulating genes such as $11{\beta}$-HSD1 and PPAR${\gamma}$ were decreased as well as expression of co-stimulatory molecules such as ICAM-1 and B7-1/-2 were also decreased with the increment of its concentration. In accordance with suppressed pro-inflammatory cytokine production lead to inhibition of diabetic regulating genes in activated macrophages. Cordycepin suppressed NF-${\kappa}B$ activation in LPS-activated macrophages. Conclusion: Based on these observations, cordycepin suppressed T2D regulating genes through the inactivation of NF-${\kappa}B$ dependent inflammatory responses and suggesting that cordycepin will provide potential use as an immunomodulatory agent for treating immunological diseases.

A Clinical Case Report on Guillain-Barre Syndrome with diplopia (복시(複視)(Diplopia)를 호소하는 Guillain-Barre Syndrome(GBS) 환자 치험 1례 증례보고)

  • Kang, Sung-Wook;Moon, Mi-Hyun;Hong, Suk-Hoon;Hwang, Chung-Yeon;Kang, Jeong-Ran;Park, Joon-Young
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.18 no.3
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    • pp.102-107
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    • 2005
  • Guillain-Barre Syndrome (GBS) is an acute inflammatory demyelinating polyneuropathy. It is disorder in which the body's immune system, attacks parts of the peripheral nervous system. It is characterized by the rapid onset of weakness, paralysis of the legs, arms, breathing muscles and face. But the analysis of CSF and electrical tests on nerve and muscle function can be performed to confirm the diagnosis. Most cases occur shortly after a viral infection. This is a clinical ease report on Cuillain-Barre Syndrome with diplopia. The patient, a 52-year-old man had a weakness in both legs and diplopia. His weakness and diplopia improved after oriental medical treatment, so this is reported as a potential treatment. Objective: This study was designed to evaluate the effects on oriental medicine therapy on Guillain-Barre Syndrome with diplopia. Methods & Result: The Clinical data was analyzed on a patient with Cuillain-Barre Syndrome whose main symptoms were diplopia. The patient was treated by acupuncture and oriental medicine. As a result, symptoms was improved remarkably. Conclusion: The patient showed weakness and diplopia. After acupuncture and oriental medicine treatment, weakness and diplopia was improved in 4weeks after visit to clinic. The study suggests that oriental medicine treatment is effective on Cuillain-Barre Syndrome.

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Sporulation and Dissemination of Pycnidiospores of Diaporthe citri in Yuzu Tree (Citrus junos Sieb) in Jeonnam Area (전남지역 유자과원의 검은점무늬병균 포자 형성과 비산)

  • Hur, Kil-Hyun;Park, Seur-Kee
    • Research in Plant Disease
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    • v.11 no.1
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    • pp.16-20
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    • 2005
  • Several time-course experiments were carried out to understand seasonal development of melanose on yuzu trees at koehung area, Jeonnam province, during May to October. The occurrence of dead twigs, known as a source of infection, was much more in older trees, and from June to August, mostly in July. In the experiment of pycnidia development on dead twigs seasonally collected, the number of developed pycnidia was highest on July-collected dead twigs especially with the diameter of 1.1~1.5 cm. In the collection survey of disseminated pycnidiospores, although the collected number of pycnidiospores was affected with amount of precipitation, the number of observed pycnidiospores in rainwater was relatively high from June to August, with highest in early August in 1997 and late July in 1998. In the inoculation tests on 3-year-old trees and fruits in natural condition, disease occurrences were mostly affected on twigs by inocula treatment in June, and on fruits by inocula treatment in July, respectively.

Development of Virulence Test Methods for Neck and Panicle Blast Disease (벼에 발생하는 목 도열병 및 이삭 도열병 검정을 위한 실험방법 개발)

  • Chi, Myoung-Hwan;Park, Sook-Young
    • Research in Plant Disease
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    • v.21 no.2
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    • pp.103-106
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    • 2015
  • Isolates of the rice blast fungus show a range of tissue-specificities infecting leaves, nodes, neck and panicles. Although neck and panicle blast cause significantly greater yield losses than the leaf blast, virulence tests of the blast isolates have been performed only rice leaves instead of neck and panicles. In this study, we have developed a virulence test method for neck and panicle blast. We selected three representative isolates from each of leaf, neck, and panicle blast. We observed that severe disease lesions developed on the neck and the panicles when the infected rice plants were incubated in a dew chamber for 48 h instead of 24 h when tested on leaves. Unlike the leaf blast, a typical lesion on the neck and panicles appeared after 14 days post-infection as opposed to 7 days with leaf blast. This method will be applied to examine tissue-specificity of the rice blast fungus isolates.

Mosquito Species Composition and Plasmodium vivax Infection Rates on Baengnyeong-do (Island), Republic of Korea

  • Foley, Desmond H.;Klein, Terry A.;Lee, In-Yong;Kim, Myung-Soon;Wilkerson, Richard C.;Harrison, Genelle;Rueda, Leopoldo M.;Kim, Heung-Chul
    • Parasites, Hosts and Diseases
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    • v.49 no.3
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    • pp.313-316
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    • 2011
  • Vivax malaria is a significant military and civilian health threat in the north of the Republic of Korea (ROK). The island of Baengnyeong-do is the westernmost point of the ROK and is located close to the southwestern coast of the Democratic People's Republic of Korea (DPRK). Mosquitoes were collected using a black light trap on Baengnyeong-do, and Anopheles spp. were assayed by PCR, to identify the species, and screened for sporozoites of Plasmodium vivax. Of a subsample of 257 mosquitoes, Anopheles lesteri was the most frequently collected (49.8%), followed by Anopheles sinensis (22.6%), Anopheles pullus (18.7%), Anopheles kleini (7.8%), and Anopheles belenrae (1.2%). The overall sporozoite rate was 3.1%, with the highest rates observed in An. kleini (15.0%), An. sinensis (5.2%), and An. lesteri (1.6%). No sporozoite positive An. pullus or An. belenrae were observed. The results extend our knowledge of the distribution and potential role in malaria transmission of An. kleini, An. lesteri, and An. sinensis, for an area previously considered to be at a low risk for contracting vivax malaria.

Development and Clinical Evaluation of a Rapid Serodiagnostic Test for Toxoplasmosis of Cats Using Recombinant SAG1 Antigen

  • Chong, Chom-Kyu;Jeong, Woo-Seog;Kim, Hak-Yong;An, Dong-Jun;Jeoung, Hye-Young;Ryu, Jeong-Eun;Ko, A-Ra;Kim, Yong-Joo;Hong, Sung-Jong;Yang, Zhaoshou;Nam, Ho-Woo
    • Parasites, Hosts and Diseases
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    • v.49 no.3
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    • pp.207-212
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    • 2011
  • Rapid serodiagnostic methods for Toxoplasma gondii infection in cats are urgently needed for effective control of transmission routes toward human infections. In this work, 4 recombinant T. gondii antigens (SAG1, SAG2, GRA3, and GRA6) were produced and tested for the development of rapid diagnostic test (RDT). The proteins were expressed in Escherichia coli, affinity-purified, and applied onto the nitrocellulose membrane of the test strip. The recombinant SAG1 (rSAG1) showed the strongest antigenic activity and highest specificity among them. We also performed clinical evaluation of the rSAG1-loaded RDT in 182 cat sera (55 household and 127 stray cats). The kit showed 0.88 of kappa value comparing with a commercialized ELISA kit, which indicated a significant correlation between rSAG1-loaded RDT and the ELISA kit. The overall sensitivity and specificity of the RDT were 100% (23/23) and 99.4% (158/159), respectively. The rSAG1-loaded RDT is rapid, easy to use, and highly accurate. Thus, it would be a suitable diagnostic tool for rapid detection of antibodies in T. gondii-infected cats under field conditions.