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Rapid and Sensitive Detection of Hepatitis C Virus in Clinical Blood Samples Using Reverse Transcriptase Polymerase Spiral Reaction

  • Sun, Wenying;Du, Ying;Li, Xingku;Du, Bo
    • Journal of Microbiology and Biotechnology
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    • v.30 no.3
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    • pp.459-468
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    • 2020
  • This study established a new polymerase spiral reaction (PSR) that combines with reverse transcription reactions for HCV detection targeting 5'UTR gene. To avoid cross-contamination of aerosols, an isothermal amplification tube (IAT), as a separate containment control, was used to judge the result. After optimizing the RT-PSR reaction system, its effectiveness and specificity were tested against 15 different virus strains which included 8 that were HCV positive and 7 as non-HCV controls. The results showed that the RT-PSR assay effectively detected all 8 HCV strains, and no false positives were found among the 7 non-HCV strains. The detection limit of our RT-PSR assay is comparable to the real-time RT-PCR, but is more sensitive than the RT-LAMP. The established RT-PSR assay was further evaluated for detection of HCV in clinical blood samples, and the resulting 80.25% detection rate demonstrated better or similar effectiveness compared to the RT-LAMP (79.63%) and real-time RT-PCR (80.25%). Overall, the results showed that the RT-PSR assay offers high specificity and sensitivity for HCV detection with great potential for screening HCV in clinical blood samples.

Toward Functional Genomics of Plant-Pathogen Interactions: Isolation and Analysis of Defense-related Genes of Rot Pepper Expressed During Resistance Against Pathogen

  • Park, Do-Il;Lee, Sang-Hyeob
    • The Plant Pathology Journal
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    • v.18 no.2
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    • pp.63-67
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    • 2002
  • To understand plant-pathogen interactions, a complete set of hot pepper genes differentially expressed against pathogen attack was isolated. As an initial step, hundreds of differentially expressed cDNAS were isolated from hot pepper leaves showing non-host resistance against bacterial plant pathogens (Xanthomonas campestris pv. glycines and Pseudomonas syringae pv. syringae) using differential display reverse transcription polymerase chain reaction (DDDRT-PCR) technique. Reverse Northern and Northern blot analyses revealed that 50% of those genes were differentially expressed in pepper loaves during non-host resistance response. Among them, independent genes without redundancy were micro-arrayed for further analysis. Random EST sequence database were also generated from various CDNA libraries including pepper tissue specific libraries and leaves showing non-host hypersensitive response against X. campestris pv. glycines. As a primary stage, thousands of cDNA clones were sequenced and EST data were analyzed. These clones are being spotted on glass slide to study the expression profiling. Results of this study may further broaden knowledge on plant-pathogen interactions.

Identification of a novel type of small molecule inhibitor against HIV-1

  • Kim, Byung Soo;Park, Jung Ae;Kim, Min-Jung;Kim, Seon Hee;Yu, Kyung Lee;You, Ji Chang
    • BMB Reports
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    • v.48 no.2
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    • pp.121-126
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    • 2015
  • Here we report a new chemical inhibitor against HIV-1 with a novel structure and mode of action. The inhibitor, designated as A1836, inhibited HIV-1 replication and virus production with a 50% inhibitory concentration ($IC_{50}$) of $2.0{\mu}M$ in an MT-4 cell-based and cytopathic protection antiviral assay, while its 50% cytotoxic concentration ($CC_{50}$) was much higher than $50{\mu}M$. Examination of the effect of A1836 on in vitro HIV-1 reverse transcriptase (RT) and integrase showed that neither were molecular targets of A1836. The characterization and re-infection assay of the HIV-1 virions generated in the presence of A1836 showed that the synthesis of early RT products in the cells infected with the virions was inhibited dose-dependently, due in part to abnormal protein formation within the virions, thus resulting in an impaired infectivity. These results suggest that A1836 might be a novel candidate for the development of a new type of HIV-1 inhibitor.

Identification and Functional Characterization of an afsR Homolog Regulatory Gene from Streptomyces venezuelae ATCC 15439

  • Maharjan, Sushila;Oh, Tae-Jin;Lee, Hei-Chan;Sohng, Jae-Kyung
    • Journal of Microbiology and Biotechnology
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    • v.19 no.2
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    • pp.121-127
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    • 2009
  • Sequencing analysis of a 5-kb DNA fragment from Streptomyces venezuelae ATCC 15439 revealed the presence of one 3.1-kb open reading frame(ORF), designated as afsR-sv. The deduced product of afsR-sv(1,056 aa) was found to have high homology with the global regulatory protein AfsR. Homology-based analysis showed that aftR-sv represents a transcriptional activator belonging to the Streptomyces antibiotic regulatory protein(SARP) family that includes an N-terminal SARP domain containing a bacterial transcriptional activation domain(BTAD), an NB-ARC domain, and a C-terminal tetratricopeptide repeat domain. Gene expression analysis by reverse transcriptase PCR(RT-PCR) demonstrated the activation of transcription of genes belonging to pikromycin production, when aftR-sv was overexpressed in S. venezuelae. Heterologous expression of the aftR-sv in different Streptomyces strains resulted in increased production of the respective antibiotics, suggesting that afsR-sv is a positive regulator of antibiotics biosynthesis.

CLONGING OF GENES EXPRESSED UPON FLORAL INDUCTION IN PHARBITIS COTYLEDONS

  • Kim, Kang-Chang;Hur, Yoon-Kang;Maeng, Jue-Son
    • Journal of Photoscience
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    • v.5 no.3
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    • pp.131-135
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    • 1998
  • Using differential display reverse transcription technique, the present study attempted to isolate and characterize genes specifically expressed in cotyledons of Pharbitis nil Choisy cv. Violet during floral induction. A total of 107 bands specific to the inductive condition were initially obtained with 80 primer sets of 20 different arbitrary primers combined with 4 kinds of T12MN. In northern blot analysis with reamplified cDNAs as probes, three cDNAs were detected to be expressed specificcally in the induced cotyledon tissues, and designated PnFL-1, PnFL-2 and PnFL-3 , the size of which were 228 bp, 317 bp and 272 bp, respectively. A search for sequences similar to the decuced amino acid sequences was conducted using GenBank and EMBL database ; seequence encoded by PnFL-1 had 29% identity with the clone of Arabidopsis thaliana similiar to reverse trascriptase (Genbank Acc. N0.3047086), PnFL-2 shared 50% identity with hydroxiyproline-rich glycoprotein of Glycine max(GenBank Acc. No.347455), and PnFL-3 had 46% identity with TAMU 4. Thaliana genomic clone T23E16 (GenBank Acc. No.B67574). None of them was known gene in the plant system up to date, implying that the fragments may comprise parts of genes which are associated with the floral induction in Pharbitis nil.

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Protective Effect of Right Ventricular Mitochondrial Damage by Cyclosporine A in Monocrotaline-induced Pulmonary Hypertension

  • Lee, Dong Seok;Jung, Yong Wook
    • Korean Circulation Journal
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    • v.48 no.12
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    • pp.1135-1144
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    • 2018
  • Background and Objectives: Mitochondria play a key role in the pathophysiology of heart failure and mitochondrial permeability transition pore (MPTP) play a critical role in cell death and a critical target for cardioprotection. The aim of this study was to evaluate the protective effects of cyclosporine A (CsA), one of MPTP blockers, and morphological changes of mitochondria and MPTP related proteins in monocrotaline (MCT) induced pulmonary arterial hypertension (PAH). Methods: Eight weeks old Sprague-Dawley rats were randomized to control, MCT (60 mg/kg) and MCT plus CsA (10 mg/kg/day) treatment groups. Four weeks later, right ventricular hypertrophy (RVH) and morphological changes of right ventricle (RV) were done. Western blot and reverse transcription polymerase chain reaction (RT-PCR) for MPTP related protein were performed. Results: In electron microscopy, CsA treatment prevented MCT-induced mitochondrial disruption of RV. RVH was significantly increased in MCT group compared to that of the controls but RVH was more increased with CsA treatment. Thickened medial wall thickness of pulmonary arteriole in PAH was not changed after CsA treatment. In western blot, caspase-3 was significantly increased in MCT group, and was attenuated in CsA treatment. There were no significant differences in voltage-dependent anion channel, adenine nucleotide translocator 1 and cyclophilin D expression in western blot and RT-PCR between the 3 groups. Conclusions: CsA reduces MCT induced RV mitochondrial damage. Although, MPTP blocking does not reverse pulmonary pathology, it may reduce RV dysfunction in PAH. The results suggest that it could serve as an adjunctive therapy to PAH treatment.

Development of reverse-transcription loop-mediated isothermal amplification assays for point-of-care testing of human influenza virus subtypes H1N1 and H3N2

  • Ji-Soo Kang;Mi-Ran Seo;Yeun-Jun Chung
    • Genomics & Informatics
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    • v.20 no.4
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    • pp.46.1-46.7
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    • 2022
  • Influenza A virus (IAV) is the most widespread pathogen causing human respiratory infections. Although polymerase chain reaction (PCR)-based methods are currently the most commonly used tools for IAV detection, PCR is not ideal for point-of-care testing. In this study, we aimed to develop a more rapid and sensitive method than PCR-based tools to detect IAV using loop-mediated isothermal amplification (LAMP) technology. We designed reverse-transcriptional (RT)-LAMP primers targeting the hemagglutinin gene. RNAs from reference H1N1 and H3N2 showed specific RT-LAMP signals with the designed primers. We optimized the reaction conditions and developed universal reaction conditions for both LAMP assays. Under these conditions, the detection limit was 50 copies for both RT-LAMP assays. There was no non-specific signal to 19 non-IAV respiratory viruses, such as influenza B virus, coronaviruses, and respiratory syncytial viruses. Regarding the reaction time, a positive signal was detected within 25 min after starting the reaction. In conclusion, our RT-LAMP assay has high sensitivity and specificity for the detection of the H1 and H3 subtypes, making it suitable for point-of-care IAV testing.

Inhibition Effect of Gamisoyo-san on MITF, TRP-1, TRP-2, Tyrosinase mRNA Expression in Melanoma Cells (B16F10) (멜라노마 세포에서 가미소요산(加味逍遙散)의 MITF, TRP-1, TRP-2, Tyrosinase mRNA 발현 억제 효과)

  • Joo, Da-Hye;Lee, Soo-Yeon;Yoo, Dan-Hee;Lee, Jin-Young
    • The Korea Journal of Herbology
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    • v.29 no.6
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    • pp.157-163
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    • 2014
  • Objectives : Gamisoyo-san complex prescription were made with Angelicae Gigantis Radix, Paeoniae Radix, Atractylodes rhizome white, Hoelen, Bupleuri Radix, Moutan Cortex Radicis, Gardeniae Fructus, Zingiberis Rhizoma Crudus, Menthae Herba. The purpose of this study was to research the whitening effect of the extract from Gamisoyo-san, which is one of the used herbal complex prescription. Methods : This study investigated inhibitory effect of Gamisoyo-san in tyrosinase activity. Cell viability were performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Then, Gamisoyo-san measured reversed-transcription-PCR for mRNA expression using B16F10 mouse melanoma cells. Results : For whitening effects, the tyrosinase inhibition effect of extract was shown to 52.4% at $5,000{\mu}g/m{\ell}$ concentration. The cell viability on B16F10 melanoma cells of Gamisoyo-san extract showed higher than 75% at $1,000{\mu}g/m{\ell}$ concentration. In this study, an experiment was performed by setting the non-toxic concentration range of 50, 150, $250{\mu}g/m{\ell}$. The Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as a positive control. The microphthalmia-associated transcription factor (MITF), tyrosinase related protein-1 (TRP-1), tyrosinase related protein-2 (TRP-2), tyrosinase mRNA expression inhibitory by reverse transcription-PCR of Gamisoyo-san extract were decreased by 95.3%, 98.8%, 96.3% and 49.5% at $250{\mu}g/m{\ell}$ which the highest concentration. Conclusions : All these findings could verify that whitening effects of Gamisoyo-san extract by tyrosinase inhibitory activity and mRNA expression. The Gamisoyo-san could be used as material for functional cosmetics, such as skin whitening products.

Valproic Acid Induces Transcriptional Activation of Human GD3 Synthase (hST8Sia I) in SK-N-BE(2)-C Human Neuroblastoma Cells

  • Kwon, Haw-Young;Dae, Hyun-Mi;Song, Na-Ri;Kim, Kyoung-Sook;Kim, Cheorl-Ho;Lee, Young-Choon
    • Molecules and Cells
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    • v.27 no.1
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    • pp.113-118
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    • 2009
  • In this study, we have shown the transcriptional regulation of the human GD3 synthase (hST8Sia I) induced by valproic acid (VPA) in human neuroblastoma SK-N-BE(2)-C cells. To elucidate the mechanism underlying the regulation of hST8Sia I gene expression in VPA-stimulated SK-N-BE(2)-C cells, we characterized the promoter region of the hST8Sia I gene. Functional analysis of the 5'-flanking region of the hST8Sia I gene by the transient expression method showed that the -1146 to -646 region, which contains putative binding sites for transcription factors c-Ets-1, CREB, AP-1 and NF-${\kappa}B$, functions as the VPA-inducible promoter of hST8Sia I in SK-N-BE(2)-C cells. Site-directed mutagenesis and electrophoretic mobility shift assay indicated that the NF-${\kappa}B$ binding site at -731 to -722 was crucial for the VPA-induced expression of hST8Sia I in SK-N-BE(2)-C cells. In addition, the transcriptional activity of hST8Sia I induced by VPA in SK-N-BE(2)-C cells was strongly inhibited by SP600125, which is a c-Jun N-terminal kinase (JNK) inhibitor, and $G{\ddot{O}}6976$, which is a protein kinase C (PKC) inhibitor, as determined by RT-PCR (reverse transcription-polymerase chain reaction) and luciferase assays. These results suggest that VPA markedly modulated transcriptional regulation of hST8Sia I gene expression through PKC/JNK signal pathways in SK-N-BE(2)-C cells.

Vibrio alginolyticus MviN is a LuxO-regulated Protein and Affects Cytotoxicity Towards Epithelioma Papulosum Cyprini (EPC) Cells

  • Cao, Xiaodan;Wang, Qiyao;Liu, Qin;Liu, Huan;He, Honghong;Zhang, Yuanxing
    • Journal of Microbiology and Biotechnology
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    • v.20 no.2
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    • pp.271-280
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    • 2010
  • Vibrio alginolyticus, a Gram-negative marine bacterium, is one of the causative agents of fish vibriosis. Its virulence factors and pathogenesis mechanism are barely known, except for some extracellular products (ECPs) that are known to be regulated by quorum sensing system. Therefore, the present study used a microarray to analyze the transcription profiles of the wild-type V. alginolyticus and a deletion mutant of luxO, the pivotal regulator in Vibrio quorum sensing systems, which resulted in the identification of a putative virulence factor, MviN. Quantitative real-time reverse transcription PCR confirmed that the transcription of mviN was upregulated in the luxO mutant when compared with wild-type, and down regulated in a luxO-con complemented strain. Furthermore, Western blotting indicated that MviN was greatly induced during the late-exponential and stationary phases of growth, indicating that the expression of MviN was cell-density dependent and quorum sensing regulated in V. alginolyticus. Meanwhile, the mviN null mutant displayed a much slower growth rate than the wild type, signifying the essential role of MviN in V. alginolyticus. Western blotting also revealed that MviN was present as an extracellular protein in V. alginolyticus. When epithelioma papulosum cyprini (EPC) cells were treated with the ECPs of the mviN mutant, no cytotoxicity was observed, whereas EPC cells treated with the wild type exhibited pathological changes, which increased with the ECPs concentration and treatment time. Therefore, the results demonstrated that MviN is a LuxO-regulated ECPs component and involved in the pathogenicity of V. alginolyticus.