• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.31-39
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• 2014

Norovirus causes acute gastroenteritis in all age groups and its food poisoning outbreaks are rapidly increasing in Korea. Reverse transcription-polymerase chain reaction (RT-PCR) is most widely used for the rapid detection of foodborne viruses due to high sensitivity. However, the false positive results of RT-PCR obtained against already inactivated viruses could be a serious drawbacks in food safety area. In this study, we investigated a method to yield true positive RT-PCR results only with alive viruses. To decompose the RNA genes from dead viruses, the enzymatic treatments composed of proteinse K and Ribonuclease A were applied to the sanitized and inactivated virus particles. Another aim of this study was to quantify the efficiencies of several major sanitizing treatments using real-time RT-PCR. Feline calicivirus (FCV) that belongs to the same Caliciviridae family with norovirus was used as a surrogate model for norovirus. The initial level of virus in control suspension was approximately $10^4$ PFU/mL. Most of inactivated viruses treated with the enzymatic treatment for 30 min at $37^{\circ}C$ were not detected in RT-PCR, Quantification results to verify the inactivation efficiencies of sanitizing treatments using real-time RT-PCR showed no false positive in most cases. We could successfully develope a numerical quantification process for the inactivated viruses after major sanitizing treatments using real-time RT-PCR. The results obtained in this study could provide a novel basis of rapid virus quantification in food safety area.

• 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.

• 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.

• 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.

• BMB Reports
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• v.45 no.3
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• pp.165-170
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• 2012

We report here that an ethanol extract of Tetracera scandens, a Vietnamese medicinal plant, has anti-HIV activity and possesses strong inhibitory activity against HIV-1 reverse transcriptase (RTase). Using a MT-4 cell-based assay, we found that the T. scandens extract inhibited effectively HIV virus replication with an $IC_{50}$ value in the range of 2.0-2.5 ${\mu}g$/ml while the cellular toxicity value (CC50) was more than 40-50 ${\mu}g$/ml concentration, thus yielding a minimum specificity index of 20-fold. Moreover, the anti-HIV efficacy of the T. scandens extract was determined to be due, in part, to its potent inhibitory activity against HIV-1 RTase activity in vitro. The inhibitory activity against the RTase was further confirmed by probing viral cDNA production, an intermediate of viral reverse transcription, in virus-infected cells using quantitative DNA-PCR analysis. Thus, these results suggest that T. scandens can be a useful source for the isolation and development of new anti-HIV-1 inhibitor(s).

• Research in Plant Disease
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• v.21 no.4
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• pp.315-320
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• 2015

Soybean mosaic virus (SMV) is a prevalent pathogen that causes significant yield reduction in soybean production worldwide. SMV belongs to potyvirus and causes typical symptoms such as mild mosaic, mosaic and necrosis. SMV is seed-borne and also transmitted by aphid. Eleven SMV strains, G1 to G7, G5H, G6H, G7H, and G7a were reported in soybean varieties in Korea. A reverse transcription loop-mediated isothermal amplification (RT-LAMP) method allowed one-step detection of gene amplification by simple procedure and needed only a simple incubator for isothermal template. This RT-LAMP method allowed direct detection of RNA from virus-infected plants without thermal cycling and gel electrophoresis. In this study, we designed RT-LAMP primers named SML-F3/B3/FIP/BIP from coat protein gene sequence of SMV. After the reaction of RT-LAMP, products were identified by electrophoresis and with the detective fluorescent dye, SYBR Green I under daylight and UV light. Optimal reaction condition was at $58^{\circ}C$ for 60 min and the primers of RT-LAMP showed the specificity for nine SMV strains tested in this study.

• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.184-189
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• 2008

The proto-oncogene protein DEK has been implicated in various human disease including cancer. We have shown that DEK induces caspase-dependent apoptosis in Drosophila by regulating histone acetylation. Reverse transcription-polymerase chain reaction (RT-PCR) method based on annealing control primers was used to screen and identify differentially expressed genes (DEGs) in DEK overexpressed HeLa cells. Among the genes identified, clusterin and fibrillarin have major role in apoptosis pathway regulation. TFIIIC and RPS24 are implicated in HAT mediated transcriptional initiation and cololectal cancer, respectively. To further analyze DEK's role in apoptosis, multiplex PCR was performed. Caspase-3, -7, and -10 and proapoptotic gene bid were newly identified as possible target genes regulated by DEK expression.

• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.177-181
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• 1999

This study was undertaken to clarify the more accurate detecting method of Dirofilaria immitis. Seven dogs, average 7.47 years old, confirmed with Dirofilaria immitis infection by modified Knott's method were used as the experimental animals. cDNA was constructed using oligodT(15) primer after extracting total RNA from the blood of dogs that were confirmed with Dirofilaria immitis infection. As a result of polymerase chain reaction with template using constructed cDNA, the predicted products of a 378 base-pair DNA fragment was amplified. From these results, RT-PCR was more sensitive and effective than modified Knott's method to detect Dirofilaria immitis in dogs.

• Journal of fish pathology
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• v.33 no.1
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• pp.71-75
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• 2020

A survey was conducted to investigate viral infections in 184 whiteleg shrimp (Litopenaeus vannamei) collected from nine farms and one wholesale fish vendor during 2018 and 2019. Gill and abdominal muscle of shrimp were tested for the presence of five viruses, viz. infectious hypodermal and haematopoietic necrosis virus, taura syndrome virus, infectious myonecrosis virus, yellow head virus genotype 1, and covert mortality nodavirus by reverse transcription-polymerase chain reaction (RT-PCR) and PCR. These viruses were not detected in any of 184 samples, screened under the study.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.27-27
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• 2003

Porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) infections are considered difficult to distinguish clinically and histopathologically. Prompt differentiation between PEDV- and TGEV-associated enteritis would greatly facilitate the management of disease in countries where PEDV and TGEV are epizootic. Rapid differential diagnosis and treatment are crucial to reducing mortality and morbidity from PEDV- and TGEV-induced enteritis in piglets. The objective for this study was to develop a protocol to differentiate between PEDV and TGEV directly from formalin-fixed, paraffin-embedded tissue, using a multiplex reverse transcription-nested polymerase chain reaction (RT-nPCR) assay. (omitted)