• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.471-476
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• 2003

Malignant catarrhal fever (MCF) is a systemic disease of ruminants caused by ovine herpesvirus 2 (OvHV-2). OvHV-2 is a gamma herpesvirus, which induces frequent latent infection and often difficult to detect its antigens and even specific nucleic acids because of its low viral copies in the infected tissues. Histopathology, serology and polymerase chain reaction (PCR) were compared for the diagnosis of MCF using 10 bison infected with OvHV-2. Histopathological diagnosis was performed using the criteria which was based upon the pathognomic lesions. Serological diagnosis was conducted using its serum with competitive ELISA for the detection of antibodies of OvHV-2. Also, the nest PCR was performed with peripheral blood leukocytes for the detection of OvHV-2-specific DNAs. Primers 556 and 775 were used for the primary amplification, and primers 556 and 555 were used for the secondary amplification. As the results, positive cases were 6 by histopahology, 9 by serology and 10 by PCR. As comparing with other diagnostic methods, PCR was found to be more sensitive than histopathology and serology. The recent development of molecular diagnostic assays has provided powerful tools for investigating how viruses survive in nature. Development of PCR specific for viruses has dramatically improved the accuracy of diagnosis of viruses in clinically infected animals. Furthermore, amplification of viral genomic material by nest PCR represents the most sensitive method for the detection of viruses and might be detected successfully even though very low viral DNA copies. So, it could be used as the first choice for the detection of viral DNAs with low copies such as the status of latent infection. However, it has also some limitation of application like as false negative results by PCR inhibitors and false positive results by contamination. The results of this study suggest that the use of molecular biological methods like PCR may increase the accuracy for the diagnosis of infectious diseases. However, in diagnostic laboratory, it is recommended that PCR assay must be conducted with other diagnostic methods for more reliable diagnosis.

• Childhood Kidney Diseases
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• v.21 no.2
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• pp.101-106
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• 2017

Purpose: The aim of this study was to analyze the incidence and microbiological characteristics of urinary tract infection in infants aged younger three months and to compare with other infection with positive urine culture. Methods: We retrospectively reviewed the medical records of 425 infants with a tympanic temperature >$37.6^{\circ}C$, aged younger than three months, who were admitted to Cheil General Hospital in Seoul, Korea, from January 2013 to December 2016. Demographic and clinical features, laboratory findings, respiratory virus PCR and the pathogens of a urine culture were analyzed. Results: A total of 88 infants (63 males, 25 females) had urinary pathogens detected in the urine culture test. The incidence of UTI in febrile infants aged younger 3 months was 11%. The most common pathogen which causes UTI was E. coli as same as in previous studies. They were divided into a UTI group (n=48) and a non-UTI group (n=40). In comparison of both group, leukocytosis, C-reactive protein level, Absolute neutrophil count level, peak temperature is statistically significant. In both group, there were co-infections with viral pathogens in some cases, and the odd ratio of non-UTI group with viral infection was 3.28. Conclusion: The study determined the incidence and pathogen of UTI in febrile infants, aged younger three months. E. coli was responsible for the majority UTI. There were some viral co-infections in febrile infants with bacteriuria and incidence was higher in non-UTI group. WBC count, ANC count and CRP level were the differentiating factors of UTI from non-UTI group.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.4
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• pp.588-595
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• 2013

Mesenchymal stem cells (MSCs) are often known to have a therapeutic potential in the cell-mediated repair for fatal or incurable diseases. In this study, canine umbilical cord MSCs (cUC-MSCs) were isolated from umbilical cord matrix (n = 3) and subjected to proliferative culture for 5 consecutive passages. The cells at each passage were characterized for multipotent MSC properties such as proliferation kinetics, expression patterns of MSC surface markers and self-renewal associated markers, and chondrogenic differentiation. In results, the proliferation of the cells as determined by the cumulative population doubling level was observed at its peak on passage 3 and stopped after passage 5, whereas cell doubling time dramatically increased after passage 4. Expression of MSC surface markers (CD44, CD54, CD61, CD80, CD90 and Flk-1), molecule (HMGA2) and pluripotent markers (sox2, nanog) associated with self-renewal was negatively correlated with the number of passages. However, MSC surface marker (CD105) and pluripotent marker (Oct3/4) decreased with increasing the number of subpassage. cUC-MSCs at passage 1 to 5 underwent chondrogenesis under specific culture conditions, but percentage of chondrogenic differentiation decreased with increasing the number of subpassage. Collectively, the present study suggested that sequential subpassage could affect multipotent properties of cUC-MSCs and needs to be addressed before clinical applications.

• Korean Journal of Pharmacognosy
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• v.49 no.4
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• pp.291-297
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• 2018

Coxsackievirus B3 (CVB3) is a very well-known causative agent for viral myocarditis and meningitis in human. However, the effective vaccine and therapeutic drug are not developed yet. CVB3 infection activates host cell AKT signaling. Inhibition of AKT signaling pathway may attenuate CVB3 replication and prevent CVB3-mediate viral myocarditis. In this study, we determined antiviral effect of the selected natural plant extract to develop a therapeutic drug for CVB3 treatment. We screened several chemically extracted natural compounds by using HeLa cell-based cell survival assay. Among them, Linum usitatissimum L. extract was selected for antiviral drug candidate. L. usitatissimum extract significantly decreased CVB3 replication and cell death in CVB3 infected HeLa cells with no cytotoxicity. CVB3 protease 2A induced eIF4G1 cleavage and viral capsid protein VP1 production were dramatically decreased by L. usitatissimum extract treatment. In addition, virus positive and negative strand genome amplification were significantly decreased by 1 mg/ml L. usitatissimum extract treatment. Especially, L. usitatissimum extract was associated with inhibition of AKT signal and maintain mTOR activity. In contrast, Atg12 and LC3 expression were not changed by L. usitatissimum extract treatment. In this study, the potential AKT signal inhibitor, L. usitatissimum extract, was significantly inhibited viral genome replication and protein production by inhibition of AKT signal. These results suggested that L. usitatissimum extract is a novel therapeutic agent for treatment of CVB3-mediated diseases.

• Fisheries and Aquatic Sciences
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• v.25 no.6
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• pp.320-326
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• 2022

Most of the emerging diseases that threaten humans are caused by RNA viruses which are extremely mutable during evolution. The fish RNA virus, viral hemorrhagic septicemia virus (VHSV) can infect a broad range of aquatic animal hosts, but the transmissibility of VHSV to mammals has not been thoroughly investigated. Therefore, our study aimed to investigate the potential adverse effects of VHSV in mammals. Briefly, the survival of VHSV was determined using only minimum essential media (MEM-2) and mammalian SNU-1411 and hepa-1c1c7s cells at 15℃ and 37℃. Mice (Mus musculus, 27.3 ± 1.9 g) were intravenously injected with VHSV (2.37E+05 TCID₅₀·mice^-1) in triplicate. Clinical signs and survival rates were examined at 14 days post-challenge, and infection was confirmed in the surviving mice. The 50% tissue culture infective dose (TCID₅₀) and polymerase chain reaction analysis were used to determine viral titers and the infection rate, respectively. The titer of VHSV suspended in MEM-2 at 15℃ was reduced by only one log after 8 days, whereas the virus maintained at 37℃ was inactivated 8 days post-inoculation (dpi). There were no recognizable cytopathic effects in either SNU-1411 or hepa-1c1c7s cells inoculated with VHSV at 15℃ and 37℃. VHSV in those cell lines at 37℃ was rapidly decreased and eventually inactivated at 12 dpi, whereas virus at 15℃ remained at low concentrations without replication. In vivo experiment showed that there were no signs of disease, mortality, or infection in VHSV-infected mice. The results of this study indicate that it is highly unlikely that VHSV can infect mammals including humans.

• Pediatric Infection and Vaccine
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• v.17 no.2
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• pp.130-136
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• 2010

Purpose : The purpose of this study is to identify the viral etiology of acute respiratory illnesses and to determine epidemiology in outpatients in Busan, Korea. Methods : We collected nasal wash samples from 990 patients who visited the hospital for acute respiratory illnesses between January 2007 and December 2008. Extracted DNA or RNA from specimens was used for viral detection by an RT-PCR method. Results : Of a total of 990 samples, viruses were detected in 351 cases (35.5%). The ratio of male to female was 1.6:1 and 93.7% were less than 5 years old. Rhinovirus was detected year-round in 202 cases (57.5%), respiratory syncytial virus from October to March in 57 cases (16.2%), adenovirus year-round in 37 cases (10.5%), influenza virus from December to April in 21 cases (6%), bocavirus from January to August in 15 cases (4.3%), parainfluenza virus from April to July in 9 cases (2.6%), coronavirus from January to July in 7 cases (2%), and enterovirus from June to September in 3 cases (0.9%). Conclusion : We identified the etiology and epidemiology of viruses that caused the acute respiratory diseases that were prevalent in Busan, 2007-2008. Further surveillance will be necessary.

• Tuberculosis and Respiratory Diseases
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• v.82 no.4
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• pp.328-334
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• 2019

Background: Although the frequency of respiratory viral infection in patients with pulmonary acute respiratory distress syndrome (ARDS) is not uncommon, clinical significance of the condition remains to be further elucidated. The purpose of this study was to compare characteristics and outcomes of patients with pulmonary ARDS infected with influenza and other respiratory viruses. Methods: Clinical data of patients with pulmonary ARDS infected with respiratory viruses January 2014-June 2018 were reviewed. Respiratory viral infection was identified by multiplex reverse transcription-polymerase chain reaction (RT-PCR). Results: Among 126 patients who underwent multiplex RT-PCR, respiratory viral infection was identified in 46% (58/126): 28 patients with influenza and 30 patients with other respiratory viruses. There was no significant difference in baseline and clinical characteristics between patients with influenza and those with other respiratory viruses. The use of extracorporeal membrane oxygenation (ECMO) was more frequent in patients with influenza than in those with other respiratory viruses (32.1% vs 3.3%, p=0.006). Co-bacterial pathogens were more frequently isolated from respiratory samples of patients with pulmonary ARDS infected with influenza virus than those with other respiratory viruses. (53.6% vs 26.7%, p=0.036). There were no significant differences regarding clinical outcomes. In multivariate analysis, acute physiology and chronic health evaluation II was associated with 30-mortality (odds ratio, 1.158; 95% confidence interval, 1.022-1.312; p=0.022). Conclusion: Respiratory viral infection was not uncommon in patients with pulmonary ARDS. Influenza virus was most commonly identified and was associated with more co-bacterial infection and ECMO therapy.

• Childhood Kidney Diseases
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• v.19 no.2
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• pp.176-179
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• 2015

Rituximab (RTX), a monoclonal antibody against the B-cell marker CD20, is commonly used as a treatment for antibody-mediated diseases or B-lymphocyte-mediated diseases. Destruction of B cells may reverse the disease course in many conditions; however, patients who are treated with RTX cannot respond appropriately to de novo infection due to lack of B lymphocytes. Here, we report one such case. A 7-year-old renal allograft recipient presented with severe anemia due to parvovirus infection after RTX treatment. The patient had focal segmental glomerulosclerosis and had received cadaveric kidney transplantation 6 months previously. She was treated with high-dose steroid for acute rejection and RTX for Epstein Barr Virus infection 3 months previously. At presentation, her hemoglobin level was 5.4 g/dL and leukocyte and platelet counts were normal. She had microcytic normochromic anemia and high viral load of parvovirus B19(70,578 copies/mL). Intravenous immunoglobulin ($200mg/kg{\cdot}d$) treatment controlled the progression of anemia and parvovirus infection. De novo parvovirus infection during the B lymphocyte-depletion period may have precipitated the severe anemia in this case. Close monitoring of infection is required after RTX therapy.

• Pediatric Infection and Vaccine
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• v.7 no.1
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• pp.83-93
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• 2000

Purpose : Urabe AM-9 strain was known to be associated with increased aseptic meningitis. The reason for high incidence of vaccine-associated meningitis was known that nucleotide(nt) substituted form G to A at position 1081 of the hemagglutinin-neuraminidase(HN) gene and therefore, glutamic acid changed to lysine at amino acid 335. We assessed by comparing nt sequence of the HN gene form Urabe AM-9 strain with wild strain and documented the correlation between nt substitution and vaccine-associated meningitis. Methods : Two lots of Urabe AM-9 vaccine distributed in Korea and mumps wild strains isolated from 1998 through 1999 were analysed. Analysis was made by nt sequencing following amplification of HN gene by RT-PCR. Results : Nucleotide substitution at position 343, 1476, 1570 was not found in both Urabe AM-9 vaccines and wild strains. But analysis of vaccine strains and wild strains isolated from patients revealed substitution from G to A at nt 1081 of the HN gene. Therefore, it encodes lysine instead of glutamic acid at amino acid 335. There was no mixture from of G and A at nt 1081. Nt at 1470 of one lot of Urabe AM-9 vaccines changed from C to A after Vero cell passage. Nt at 1727 of vaccines and wild strains was substituted A to G, so it encodes glycine instead of aspartic acid. Conclusion : Nucleotide analysis of HN gene revealed that nt 1081 of Urabe AM-9 vaccines and wild strains had wild type AAA($Lys^{335}$) instead of variant type GAA($Glu^{335}$). The results of this study suggest that there was a probability of vaccine-associated meningitis due to Urabe AM-9 in Korea before. But incidence of actual side effect was not evaluated because there was no reporting system in Korea.

• Korean Journal of Veterinary Service
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• v.28 no.1
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• pp.49-69
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• 2005

More than 30 years have elapsed since the first report of the International Committee on Taxonomy of Viruses (ICTV) was published in 1971. Since that publication, the ICTV recognizes about 1,550 virus species, but some 30,000 virus strains and isolates are being tracked by virologists in different fields of biology. The ICTV is the 'international court' of experts that rules on names and relationships of all virus, but only to the level of species. Virus taxonomy is changing rapidly, with changes ranging from the trivial(use of italics for species names) to profound reorganization driven by the explosion of sequence information. The universal system of viral taxonomy now accepts Linnean-like classification at the levels of order, family, subfamily, genus, and species. The suffix '-virales' identifies an order, Families are identified by the suffix '-viridae' subfamilies are identified by the suffix '-virinae', and genera are identified by the suffix '-virus'. The importance of distinguishing subspecies, strains, and isolates in vaccine development, diagnostics, etc. is recognized, but these lower levels are not formally classified by ICTV. This paper mainly introduces taxonomy and classification of animal viruses on the basis of the seventh report of the ICTV edited by Van Regenmortal et al. in 2000.