• 대한바이러스학회지
• /
• 제28권3호
• /
• pp.275-285
• /
• 1998

Based on the geographic range and distribution of its rodent reservoir host, the European common vole (Microtus arvalis), Tula virus is likely to be widespread throughout Eurasia. Tula virus-infected voles have been captured in Central Russia, Austria, Czech and Slovak Republics, and the former Yugoslavia. Although serologic evidence for Hantaan (HTN) or Seoul (SEO) virus infection can be found in the vast majority of the more than 300 cases of hemorrhagic fever with renal syndrome (HFRS) occurring annually in Korea, approximately 4% of Korean patients with HFRS show a more than 4-fold higher antibody titer to Puumala (PUU) virus than to HTN or SEO virus by double-sandwich IgM ELISA, suggesting the existence of pathogenic Puumala-related hantaviruses in Korea. To further define the geographic distribution and genetic diversity of Tula virus in Eurasia and to investigate the existence of previously unrecognized Microtus-borne hantavirus in Korea, arvicolid rodents were captured in Lodz, Poland in 1995 and in Yunchon-kun, Kyungki-do during April to May, 1998. In addition, sera from 18 Korean HFRS patients who showed higher (or the same) antibody titer to Tula virus than HTN and SEO viruses were examined for hantavirus RNA by RT-PCR. Hantaviral sequences were not detected in any of the 18 patients or in 35 reed voles (Microtus fortis) in Korea. Alignment and comparison of a 208-nucleotide region of the S segment, amplified from lung tissues of two hantavirus-seropositive Marvalis captured in Poland, revealed $80.8{\sim}83.2%$ sequence similarity, respectively, with Tula virus strains from Central Russia and the Czech and Slovak Republics. Phylogenetic analysis indicated that the newfound Tula virus strains from Poland were closely related to other Tula hantaviruses from Eurasia.

• 한국응용곤충학회지
• /
• 제16권3호
• /
• pp.145-148
• /
• 1977

감자바이러스 S(PVS)의 진단, 동정 및 씨감자의 검정에 이용할 항혈청을 만들기 위하여 이병주로부터 PVS를 순수분리 순화하여 항혈청을 제조하였다. PVS는 지표식물파 전자 현미경으로 순수 분리하여 Nicotiana debneyii에서 증식하여 순화하였다. 순화된 PVS의 순화도는 1.18mg/ml이었으며 이것을 1.5ml씩 7일 간격으로 5회 .토끼에 주사하였으며 마지막 주사후 10일에 채혈하여 항혈청을 분리하였다. 제조된 PVS항혈청의 역가는 미량침강법에 의하여 1/2048로 나타났다.

• BMB Reports
• /
• 제30권3호
• /
• pp.234-236
• /
• 1997

Chronic hepatitis C virus (HCV) infection is associated with the rapid development of cirrhosis and hepatocellular carcinoma. It has been reported that the amount of HCV RNA may be correlated with the progression of hepatitis and may be a prognostic marker for treatment of HCV patients. The direct detection of HCV RNA by reverse transcription-polymerase chain reaction (RT-PCR) is widely used to determine the presence of circulating virions. The most relevant limit of this approach is the lack of quantitative information about the viral titer. In the present study, we developed the method for HCV quantitation using competitive reverse transcription (CRT)-PCR using the deleted HCV standard. The serially diluted standard was added in titrated amounts to the target HCV RNA. The mixture was then reverse transcribed and amplified in the same reaction tube. The methods were evaluated using over 110 HCV-PCR positive samples in Koreans. About 59% of the samples were judged to contain $10^{5}-10^{6}$ copies of HCV RNA in 1 ml of serum.

• 대한수의학회지
• /
• 제35권4호
• /
• pp.753-758
• /
• 1995

The study was carried out to investigate the pathogenicity of EHV isolate to hamsters and mice and immunogenicity of experimentally produced. vaccine were evaluated in the horses. Hamsters infected. intranasally with $LC_1$ isolate showed symptoms of nasal discharge, conjunctivitis and body weight loss during the observation period of 12 days after infection, while only slight depression and body weight loss were noticed with mice infected with $LC_1$ indicating that hamsters are more susceptible to the virus. Antibody titer of mice and hamsters were gradually increased to highest level of 1:2560~10240, 1:640~1280, respectively, at 7~12 days post vaccination. Horses immunized against $LC_1$ killed vaccine reached to maximum antibody titer of 1:20480 around 4 weeks after 1st vaccination and declined after 12 weeks post vaccination. No significant antibody increase were detected after 2nd vaccination. Mean body temperature and mean total leukocyte counts remained within normal range and no adverse reaction were noticed after vaccination.

• 한국동물위생학회지
• /
• 제13권1호
• /
• pp.96-102
• /
• 1990

The immune responses of commercial layer chickens against Newcastle disease(ND) were compared among different administration methods and times of vaccination during 4 weeks of age. A total of 372 day-old chickens were divided into 4 groups of 93 birds each. Each of 3 groups was received a commercially available B$_1$live vaccine via drinking water, eye instillation or spray method at one, 14 and 28 days of age. One group was used as an unvaccinated control. At two and 4 weeks after each time of vaccination, 15 birds from each group were collected randomly out and challenged with virulent ND virus at the dose of $10^5E1D_{50}$ per bird. Ten to 15 birds from each group were bled at two weeks intervals from day old to 8 weeks of age for hemagglutination inhibition antibody titer, The protection rate was generally low regardless of the times of vaccination although two or more times vaccination gave higher protection than once vaccination. The low protection was considered due to low titer of the vaccine used since the vaccine titer was less than $10^{3.5}EID_{50}$ per bird. Spray method gave better protection compared to eye instillation or drinking water method which resulted in lowest response. Majority of birds showed clinical signs of ND between 3 and 6 days after challenge. Death occured one or two days after onset of symptoms. Major clinical signs observed were depression(94%), anorexia(84%), diarrhoea(29%), difficult breath(15%) and torticollis(10%). Hemorrhagic lesions on post mortem were seen in duodenum(51%), trachea(35%), illeum(13%), ceacal tonsil(11%), proventriculus(10%) and some other odrgans.

• 한국응용곤충학회지
• /
• 제14권4호
• /
• pp.193-198
• /
• 1975

벼줄무늬잎마름병 바이러스에 대한 혈청학적인 검토결과를 다음과 같이 적요한다. 1. 벼줄무늬잎마름병 바이러스는 항원성을 갖고 있으며 항체와 특이적인 혈청반응을 타나냈다. 2. 가토 정맥주사에 의한 항혈청의 항체가는 아주 낮아 16배에 불과하였다. 3. 벼 품종 $\ulcorner$사도미노리$\lrcorner$에 있어서 침강반응혼합법으로 측정한 결과 이병엽의 병징정도에 따라 바이러스 농도에 차이가 인정되는데 병징정도가 심할수록 바이러스농도가 높았다. 4. 동정도의 병징이라도 벼품종에 따라 바이러스농도가 달랐는데 저항성품종인 $\ulcorner$통일$\lrcorner$에서는 높았고 이병성인 $\ulcorner$사도미노리$\lrcorner$, $\ulcorner$팔굉$\lrcorner$, $\ulcorner$만경$\lrcorner$, $\ulcorner$니혼바레$\lrcorner$에서는 낮았다. 그러나 저항성 품종인 $\ulcorner$유신$\lrcorner$에서는 낮았다. 5. 항체감작적혈구 응집반응에 의한 항체가는 아주 높아 512배였으며 보독충의 검정시험에서도 반응이 잘 나타나 $38\%$라는 보독충율을 나타냈다.

• 대한수의학회지
• /
• 제31권2호
• /
• pp.189-194
• /
• 1991

Getah virus is known as a causative agent of recognized febrile illness of horses characterized by fever, rash and edema. A serological survey indicated that hemagglutination inhibition antibody against Getah virus was detected in 34% of 464 racehorses from Korean Horse Affairs Association and 57% of 262 ponies from Cheju island, respectively. Several field strains of Getah virus isolated were from the racehorse that have been shown fever and febrile signs in 1989. The field isolates produced cytopathic effect in Vero, MA-104, BHK-21 cell cultures. Especially, they multiplied to the highest titer($10^6TCID_{50}/0.1ml$) in Vero cell cultures. When day-old mice were inoculated with field isolates by the intracerebral route, they showed a typical paralysis sign and died within seven days after inoculation. The guinea pig exhibited skin rash and edema, and died with neural signs after inoculation with the field isolates. In the cross neutralization test and indirect immunofuorescent assay, the field isolates were proved to be closely related to the Sakai strain of Getah virus antigenically.

• Journal of Microbiology and Biotechnology
• /
• 제21권1호
• /
• pp.100-108
• /
• 2011

A method for the rapid detection and quantification of Newcastle disease virus (NDV) produced in an animal cell culture-based production system was developed to enhance the speed of the NDV vaccine manufacturing process. A SYBR Green I-based real-time RT-PCR was designed with a conventional, inexpensive RT-PCR kit targeting the F gene of the NDV LaSota strain. The method developed in this study was validated for specificity, accuracy, precision, linearity, limit of detection (LOD), limit of quantification (LOQ), and robustness. The validation results satisfied the predetermined acceptance criteria. The validated method was used to quantify virus samples produced in an animal cell culture-based production system. The method was able to quantify the NDV samples from mid- or late-production phases, but not effective on samples from the early-production phase. For comparison with other quantifiable methods, immunoblotting, plaque assay, and tissue culture infectious dose 50 ($TCID_{50}$) assay were also performed with the NDV samples. The results demonstrated that the real-time RT-PCR method is suitable for the rapid quantification of virus particles produced in an animal cell-culture-based production system irrespective of viral infectivity.

• 생약학회지
• /
• 제30권1호
• /
• pp.25-33
• /
• 1999

In order to find less toxic antiviral agents from basidiomycetes, EA, the water soluble substance, was prepared from the carpophores of Elfvingia applanata (Pers.) Karst. EA was examined for antiviral activity against five strains of pathogenic viruses such as encephalomyocarditis virus (EMCV), vesicular stomatitis virus (VSV) Indiana and New Jersey strains, influenza A virus (Flu A), and varicella zoster virus (VZV) in vitro. Antiviral activity was evaluated by plaque reduction assay. Among five strains of viruses tested, EA exhibited the most potent antiviral activity against VSV Indiana strain with 50% effective concentration $(EC_{50})$ of 0.104 mg/ml in Vero cells, and its selectivity index (SI) was 36.5. EA was also examined for the virucidal activity, antiviral activity in preincubation on VSV Indiana strain in order to examine possible mode of antiviral activity. Preincubation of Vero cells with EA did not confer protection against VSV, however, prolonged exposure of cells to EA inhibited the replication of virus dose-dependently. In virucidal activity, the titer of infectious virus did not decrease significantly.

• KSBB Journal
• /
• 제26권2호
• /
• pp.107-111
• /
• 2011

The essential operating parameters in virus vaccine production are multiplicity of infection (MOI), harvest time, and infection time. Stimulating agents also can be applied in order to improve vaccine productivity further. We investigated the optimum operating conditions in porcine transmissible gastroenteritis virus (TGEV) vaccine production and the applicability of sodium butyrate (NaBu) as a stimulating agents for the improvement of vaccine productivity. The optimum MOI, infection time, and harvest time for high production of TGEV by swine testicle (ST) cells were found to be 0.0001 pfu/cell, 3 day after cell inoculation, and 24 hpi, respectively. NaBu is known as a histone deacetylase inhibitor that has been widely used for the high expression of recombinant protein using mammalian cells and for the enhancement of virus propagation. So we tried to examine the potential of NaBu as a stimulating agent and to determine the optimum concentration by comparing TGEV titers with different range of NaBu concentration. TGEV titer with 5 mM NaBu was 1.5 times higher than control. Therefore, we concluded that NaBu can be a promising agent for stimulating various vaccine production including TGEV and the optimum NaBu concentration for TGEV production was determined to be 5 mM.