• 대한임상검사과학회지
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• 제36권1호
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• pp.33-37
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• 2004

In order to study the effect of temperature of denaturation, annealing and extension and cycles on amplification of DNA by PCR method, We isolated the hepatitis B virus DNA from hepatitis B patient blood and compared the density of DNA amplified by Reference PCR Program (denaturation at $94^{\circ}C$ for 30 sec., annealing at $60^{\circ}C$ for 1 min., extension at $72^{\circ}C$ for 1 min., holding at $72^{\circ}C$ for 5min., 30 cycles) that is usually used in laboratory to the density of DNA amplified by PCR program changed only the denaturation temperature or annealing temperature or extension temperature. We amplified about 341bp of hepatitis B virus DNA by Reference PCR Program from hepatitis patient blood, but the DNAs denatured at $72^{\circ}C$ or $60^{\circ}C$ were not detectable on photoradiography film. The DNA amplified at $37^{\circ}C$ of annealing temperature was not detectable, but the DNA annealed at $72^{\circ}C$ was detectable the lower density of DNA than the DNA amplified by Reference PCR Program. Each DNA amplified by PCR program changed only the extension temperature to $37^{\circ}C$ or $60^{\circ}C$ was almost same density as DNA amplified by Reference PCR Program. We compared the density of hepatitis B virus DNA amplified by Reference PCR Program for 30 cycles, 20 cycles, 10 cycles, and 5 cycles. The DNA cycled for 20 cycles was not amplified well as cycled for 30 cycles, but the DNA was detectable on the photoradiography film. The DNAs amplified for 10 cycles or 5 cycles were not detectable on photoradiorgaphy film. The concentration of hepatitis B virus DNA amplified in Reference PCR condition for 30 cycles, 20 cycles, 10 cycles, and 5 cycles were $72{\mu}g/m{\ell}$, $83{\times}10^{-3}{\mu}g/m{\ell}$, $27{\times}10^{-6}{\mu}g/m{\ell}$, and nondetectable, respectively.

• Biomolecules & Therapeutics
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• 제23권4호
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• pp.345-349
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• 2015

Betulinic acid, a pentacyclic triterpene isolated from Jujube tree (Zizyphus jujuba Mill), has been known for a wide range of biological and medicinal properties such as antibacterial, antimalarial, anti-inflammatory, antihelmintic, antinociceptive, and anticancer activities. In the study, we investigated the antiviral activity on influenza A/PR/8 virus infected A549 human lung adenocarcinoma epithelial cell line and C57BL/6 mice. Betulinic acid showed the anti-influenza viral activity at a concentration of $50{\mu}M$ without a significant cytotoxicity in influenza A/PR/8 virus infected A549 cells. Also, betulinic acid significantly attenuated pulmonary pathology including increased necrosis, numbers of inflammatory cells and pulmonary edema induced by influenza A/PR/8 virus infection compared with vehicle- or oseltamivir-treated mice in vivo model. The down-regulation of IFN-${\gamma}$ level, which is critical for innate and adaptive immunity in viral infection, after treating of betulinic acid in mouse lung. Based on the obtained results, it is suggested that betulinic acid can be the potential therapeutic agent for virus infection via anti-inflammatory activity.

• 한국어병학회지
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• 제35권1호
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• pp.41-46
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• 2022

Since viral haemorrhagic septicaemia virus (VHSV) was first reported in European rainbow trout (Oncorhynchus mykiss) in the 1930s, it has caused high prices in freshwater and saltwater fish around the world, causing enormous economic damage to the aquaculture industry. We have been seeking required countermeasures against viruses because of economic damage to the aquaculture industry. However, commercial vaccines have the limitations of being costly to use in farms and being effective to only one pathogen. The aquaculture industry these days is taking on new alternatives to vaccines, antibiotics and chemicals. In this study, the suitability of antiviral effects against VHSV was evaluated in vitro for various plant extracts to judge their effectiveness. Atriplex gmelinii, Ixeris repens, Arctium lappa, and Sargassum coreanum were tested to know the correlation between the amount of virus and the concentration of extract investigates if these extracts have antiviral effects. Virus and extracts at various concentrations were inoculated simultaneously as 1:1 ratio into EPC cell lines. There are no antiviral effects with Atriplex gmelinii, Ixeris repens and Arctium lappa. Extract of Sargassum coreanum only has the antiviral activity in a dose-dependent manner. These results show that extract of Sargassum coreanum can be used in aquaculture industry as an antiviral materials.

• Korean Chemical Engineering Research
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• 제50권4호
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• pp.738-742
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• 2012

본 연구에서는 알루미나 나노 템플레이트(anodic alumina oxide; AAO)를 이용하여 신속하면서도 효과적으로 나노입자 및 바이오물질을 분리, 농축할 수 있는 나노필터 소자를 개발하였다. 본 연구에서 사용한 나노필터 소자는 유체의 주입 및 흐름이 가능한 미세유체채널(microfluidic channel)을 PDMS에 패터닝하였다. 위아래로 형성된 PDMS 미세유체채널 사이로, 다양한 크기의 나노 다공을 형성하고 있는 AAO 막을 삽입하여 크기에 따른 나노입자 및 바이오 물질을 분리할 수 있었다. 위아래로 PDMS 유체채널과 AAO 분리막을 집적하고, 최종적으로 아크릴레이트 플락스틱(acrylic plastic)으로 전체 소자를 고정하여 나노필터유체소자를 제작하였다. 완성된 나노필터소자를 이용하여 나노입자의 농축효율 및 은나노입자가 뭉쳐져있는 필터존(filtration zone)으로부터 뎅기 바이러스(dengue virus)를 표면증강라만(surface enhanced Raman scattering)분석법에 의해 검출할 수 있었다.

• 대한수의학회지
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• 제40권3호
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• pp.611-625
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• 2000

For the improvement of quality control of laboratory mouse, we investigated the environmental condition, histopathological findings and serological test using ELISA to mouse hepatitis virus(MHV), Mycoplasma pulmonis(MP), Clostridium piliforme(TZ) and Sendai virus (HVJ) of ICR, C57BL/6, CBA and C3H/He mice that were supplied from conventional laboratory animal facility. 1. The ammonia concentration of facility was below the recommended concentration, 15ppm, by the KNIH, and the room temperature($21{\sim}23^{\circ}C$) and relative humidity(40~60%) was optimum range recommend by the Ministry of Health and Welfare, respectively. 2. The incidence rate of inapparent disease was 86.6% and the major findings in the liver were vacuolar degeneration with nucleic pleomorphism. The lung was shown the thickening of alveolar wall and interstitial pneumonia with congestion. The kidney and spleen were observed the mild congestion and extramedullary hematopoiesis, respectively. 3. The positive reaction rates against MHV and MP in serological test was 97.9% and 37.5%, respectively but HVJ and TZ were negative. These results suggest that laboratory mice could be infected with MHV and MP under conventional environments. Therefore we recommend to select thoroughly inapparent infected mice and to convert conventional system into SPF facility as soon as possible.

• Preventive Nutrition and Food Science
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• 제5권3호
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• pp.170-173
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• 2000

The inhibitory effect of extracts from 15 edible plants on the protease of human immunodeficiency virus (HIV) type 1 was investigated. Protease activity was determined by incubating the extracts in a reaction mixture containing protease and substrate His-Lys-Ala-Arg-Val-Leu-(p-NO$_2$-Phe)-Glu-Ala-Nle-Ser-NH$_2$ to inhibit proteolytic cleavage. Of various plants tested, the leaves of Cedrela sinensis inhibited the HIV-1 protease by 42% at a concentration of 100$\mu\textrm{g}$/ml. A major flavonoid isolated from the leaves of C. sinensis, quercetin 3-O-$\alpha$-L-rhamnoside showed inhibitory activity of 19% at a concentration of 100$\mu$M.

• 생약학회지
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• 제30권2호
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• pp.151-157
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• 1999

In order to find less toxic antiherpetic agents, the effect of natural quercetin on the plaque formation of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) was studied in vitro in cell culture monolayers employing the technique of viral plaque reduction assay. Quercetin caused a concentration-dependent reduction in the plaque formation of herpesviruses. It also exhibited more potent antiherpetic activity on HSV-1 with effective concentration $(EC_{50})$ of $18.7\;{\mu}g/ml$ than on HSV-2 with $EC_{50}$ of $24.5\;{\mu}g/ml$. The combined antiherpetic effects of quercetin with nucleoside antiherpetic agents, acyclovir and vidarabine, were examined on the multiplication of these two strains of herpesviruses in Vero cells by the combination assay. The results of combination assay were evaluated by the combination index (CI) that was calculated by the multiple drug effect analysis. The combinations of quercetin with acyclovir on HSV-1 and HSV-2 showed more potent synergism with CI values of $0.19{\sim}0.89$ for 50%, 70%, 90% effective levels than those with vidarabine with CI values of $0.43{\sim}1.46$.

• BMB Reports
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• 제32권5호
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• pp.492-496
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• 1999

We have investigated the biochemical properties of the herpes simplex virus type 1 (HSV-1) DNA polymerase without the UL42 protein (Pol), purified from insect cells infected with a recombinant baculovirus containing the UL30 gene. BSA and DTT have inhibitory effects on dAMP incorporation. Pol showed a greater turnover rate of steady-state single nucleotide incorporation at 12 mM $MgCl_2$ than at 2 mM $MgCl_2$. However, it showed a greater processivity of DNA synthesis at lower $MgCl_2$ concentration (1 mM, 2 mM) than at a higher $MgCl_2$ concentration (12.5 mM). These results are consistent with a slow DNA dissociation at lower $MgCl_2$ concentrations. Pol does not incorporate a correct nucleotide into the primer with an incorrect nucleotide at the end; instead, it preferentially excises the incorrect nucleotide at the 3' end of the primer. Pol has DNA polymerase activity at pHs 6.5 and 7.5 but little at pHs 5.5, 8.5, and 9.5. It has exonuclease activity at pHs 6.5, 7.5, and 8.5 but little at pHs 4.5, 5.5, and 9.5. The finding that Pol has exonuclease activity but not DNA polymerase at pH 8.5 suggests that DNA binds to Pol, but deoxynucleotide binding or incorporation does not occur at pH 8.5.

• Biomolecules & Therapeutics
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• 제7권2호
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• pp.158-163
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• 1999

In order to find less toxic antiherpetic agents, antiviral activities of quercitrin against two strains of pathogenic viruses such as herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) were determined in Vero cells using plaque reduction assay in vitro. Quercitrin showed a concentration-dependent decrease in plaque formation of HSV-1 and HSV-2. It also exhibited more potent antiherpetic activity on HSV-1 with 50% effective concentration (EC$_{50}$) of 20.4 $\mu$g/ml than on HSV-2 with EC$_{50}$ of 30.4 $\mu$g/ml. The combined antiherpetic effects of quercitrin with nucleoside antiherpetic agents, acyclovir and vidarabine, were examined on the multiplication of these two strains of herpesviruses in Vero cells by the combination assay. The results of combination assay were evaluated by the combination index (CI) that was calculated by the multiple drug effect analysis. The combinations of quercitrin with acyclovir and vidarabine on HSV-1 showed more potent synergism with CI values of 0.27-0.81 for 50%, 70%, 90% effective levels than those on HSV-2 with CI values of 1.03~2.20..20.

• KSBB Journal
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• 제13권6호
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• pp.662-668
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• 1998

Viruses belonging to the Hantavirus genus cause two acute severe illness in humans, i.e., Haemorrhagic Fever with Renal Syndrome (HFRS) and Hantavirus Pulmonary Syndrome(HPS). Among them, Hantaan virus is one of the most important viruses causing HFRS. Recombinant expression vectors, pKK-NP and pET-NP, with Hantaan viral nucleocapsid gene were constructed, and used to transform Eschericia coli BL21(DE3). Stability of the vectors in the host strain, and effects of some environmental conditions on the expression of nucleocapsid gene were studied. Expression vector, pKK-NP, was very unstable, and the expression level of nucleocapsid gene was very low compared to that of pET-NP. BL21(pET-NP) produced about 100 mg of N protein per liter of culture broth. Induction time did not show any significant difference on the expression level of nucleocapsid gen and cell growth. BL21(pET-NP) culture at 35$^{\circ}C$ showed a little higher expression level than at 30$^{\circ}C$ during growth phase, but reached to the same level at stationary phase. Total expression level was proportional to supplemented glucose concentration of media up to 0.5% along with cell growth, but expression level per unit cell mass was inversely proportional to glucose concentration and maximal when glucose was not supplemented at all.