• 대한수의학회지
• /
• 제29권4호
• /
• pp.531-540
• /
• 1989

A new sudden death in rabbits appeared in China and Korea in 1984 and 1985, respectively, and was recognized to be an acute infectious disease caused by a virus. The disease was reported as a "new viral disease," and thereafter, a tentative name of "viral hemorrhagic disease", "hemorrhagic pneumonia" or "viral hemorrhagic pneumonia" has been described in the case reports. But authors had called the viral disease "rabbit viral hepatitis" due to picornavirus infection, because the principal lesion of the disease was an acute hepatitis. The purpose of this report is to describe the electron microscopic findings on the livers in experimentally infected rabbits. All the livers of the affected rabbits were shown to have degenerative changes of a type that is characteristic of acute hepatitis. In the liver cells, there were dilation of rER and mitochondria, vacuole formation of various sizes, and appearances of many virus-like particles in the vicinity of rER, granular bodies and crystalline arrays of viral particles in the cytoplasm with necrotic changes of the nucleus. Clusters of virus-like particles and viral crystals appeared in the cytoplasm of sinusoid endothelial cells and Kupffer's cells with morphological changes of organelles. Also viral crystals were demonstrated in the cytoplasm of macrophages among the liver cells. On the whole, the liver cells had many virus-like particles and a few crystalline arrays of viral particles. Therefore, this implies that the liver cells are the main site of the viral replication in inducing the viremia. It was concluded that the liver was the primary target organ of this viral disease, and the pathological and the ultrastructural evidence suggest that the virus may be belong to genus enterovirus.

• 대한수의학회지
• /
• 제60권4호
• /
• pp.195-202
• /
• 2020

Feline calicivirus (FCV) infection results in a common upper respiratory disease associated with oral ulceration in cats. Although FCV infection has been reported in cats worldwide, the biologic and genetic features of South Korean FCV are unclear. We aimed to investigate the biological and genetic features of South Korean FCV isolates. Crandell-Rees feline kidney (CRFK) cells were used to isolate FCV from 58 organ homogenate samples. The FCV isolates were confirmed by cytopathic effects, immunofluorescence, electron microscopy, and reverse transcription polymerase chain reaction assays. Viral genetic analysis was carried out with VP2 gene and complete genomes of FCVs. Five viruses propagated in CRFK cells were confirmed to be FCVs. The FCV17D283 isolate showed the highest viral titer of 107.2 TCID50/mL at 36 h post-inoculation. Korean FCV isolates did not grow well in Vero, BHK-21, A72, or Madin-Darby canine kidney cells. The FCV17D03 and FCV17D283 isolates had the highest genetic similarity (80.1% and 86.9%) with the UTCVM-H1 and 14Q315 strains, which were isolated in the United States and South Korea in 1995 and 2014, respectively. We isolated five FCVs from cats and detected important genetic differences among them. FCV isolates did not show any virulent effects in mice.

• IMMUNE NETWORK
• /
• 제14권4호
• /
• pp.187-200
• /
• 2014

Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) are the most common cause of genital ulceration in humans worldwide. Typically, HSV-1 and 2 infections via mucosal route result in a lifelong latent infection after peripheral replication in mucosal tissues, thereby providing potential transmission to neighbor hosts in response to reactivation. To break the transmission cycle, immunoprophylactics and therapeutic strategies must be focused on prevention of infection or reduction of infectivity at mucosal sites. Currently, our understanding of the immune responses against mucosal infection of HSV remains intricate and involves a balance between innate signaling pathways and the adaptive immune responses. Numerous studies have demonstrated that HSV mucosal infection induces type I interferons (IFN) via recognition of Toll-like receptors (TLRs) and activates multiple immune cell populations, including NK cells, conventional dendritic cells (DCs), and plasmacytoid DCs. This innate immune response is required not only for the early control of viral replication at mucosal sites, but also for establishing adaptive immune responses against HSV antigens. Although the contribution of humoral immune response is controversial, $CD4^+$ Th1 T cells producing IFN-${\gamma}$ are believed to play an important role in eradicating virus from the hosts. In addition, the recent experimental successes of immunoprophylactic and therapeutic compounds that enhance resistance and/or reduce viral burden at mucosal sites have accumulated. This review focuses on attempts to modulate innate and adaptive immunity against HSV mucosal infection for the development of prophylactic and therapeutic strategies. Notably, cells involved in innate immune regulations appear to shape adaptive immune responses. Thus, we summarized the current evidence of various immune mediators in response to mucosal HSV infection, focusing on the importance of innate immune responses.

• 대한바이러스학회지
• /
• 제29권3호
• /
• pp.165-174
• /
• 1999

To investigate viral pathogenesis and in vivo efficacy of acyclovir (ACV) in mouse HSV-1 encephalitis models, female BALB/c mice aged 5 weeks were inoculated with strain F either intranasally (IN) or intracerebrally (IC). ACV-treatment by intraperitomeal injection with 0, 5, 10 and 25 mg/kg b.i.d. for 6 days was commenced 1 h after infection. Body weight and signs of clinical disease were noted daily up to 2 weeks. $ED_{50}$ of ACV in IN infection was <5 mg/kg and 14.1 mg/kg in IC infection. Tissues of central nervous system were collected from 2 mice per group everyday up to 5 day p.i. and the virus titers were measured. In IN infection model, high titers in eyes and trigeminal nerves were observed. ACV-treatment showed significant reduction of the titers in all the isolated. In IC infection model, cerebrum, cerebellum and brain stem showed high virus titers. ACV-treatment showed less significant reduction of virus titers than that in IN infection model. Reactivation of explanted trigeminal nerves from mice 30 day p.i. was monitored. In all of ACV treated mice reactivation was observed, i.e. even the highest dose of ACV did not inhibit the establishment of viral latency.

• Pediatric Infection and Vaccine
• /
• 제10권1호
• /
• pp.87-94
• /
• 2003

목 적 : 호흡기 바이러스는 인간에게 가장 전염성이 강한 병원체의 하나로 급성 호흡기 감염 특히 하기도 감염증은 소아에서의 유병률과 사망률의 주요 원인이 되고 있다. 저자들은 하기도 감염증에 이환된 환아들을 대상으로 influenza A, B virus, adenovirus, enterovirus의 감염 연령 분포와 계절적 유행 양상, 바이러스별 임상 양상을 알기 위하여 이 연구를 시작하였다. 방 법 : 2002년 1월부터 2002년 12월까지 부산 메리놀병원에 입원하거나 외래 방문한 하기도 감염증 소아들을 대상으로 인후 가검물, 콧물, 타액 분비물 등을 채취하여 바이러스를 동정하였고, 검사를 시행한 568명 중 바이러스가 동정된 54명을 대상으로 호발 연령, 유행 시기, 임상 증상을 후향적으로 조사하였다. 결 과 : 1) 대상 환아의 연령 분포는 2개월부터 14세 사이였고, 남녀비는 1.8 : 1이었다. 3~6세가 29.6%로 가장 많았고, 2~3세 사이가 14.8%, 12세 이상이 13% 순이었다. 2) 동정된 바이러스는 influenza A virus가 59.3%로 가장 많았고, enterovirus가 33.3%, adenovirus 5.6%, influenza B virus 1.9%였고, parainfluenza virus와 RSV는 동정되지 않았다. 3) 임상 양상은 폐렴이 51.9%로 가장 많았고, 기관지염이 31.5%, 크루프 9.3%, 모세기관지염 7.4%의 순이었다. 4) 호흡기 바이러스는 각각의 유행 시기가 있어, influenza A virus는 3~5월, 11월에 2차례의 유행이 있어 주로 겨울에 유행하는 양상을 보였으며, influenza B virus는 3월에, adenovirus는 3월과 7월에, enterovirus는 3~7월에 유행하여 주로 봄부터 여름까지 유행하는 양상을 보였다. 결 론 : 2002년 부산 지역 호흡기 바이러스 감염의 주된 원인은 influenza virus였다. 이러한 결과는 influenza virus의 유행을 보여주는 것으로 이에 대한 지속적인 감시와 예방, 조기 진단과 치료가 필요하다고 하겠다.

• 대한수의학회지
• /
• 제64권1호
• /
• pp.3.1-3.8
• /
• 2024

Canine distemper virus (CDV), canine adenovirus type 2 (CAV-2), canine parvovirus (CPV), and canine parainfluenza virus 5 (CPIV-5) are the major viral pathogens in dogs. Despite the availability of vaccines for dogs against these 4 viral pathogens, investigations of antibodies against these pathogens have rarely been reported in South Korea. In this study, we investigated the recent incidence of viral diseases in dogs and conducted sero-surveillance for CDV, CAV-2, CPV, and CPIV-5 in Korean dogs. The most frequently diagnosed canine viral disease in Korean dog samples from 2000 to 2022 was CPV infection, which accounted for 48.7% (464/953) of the cases. A total of 400 dog serum samples collected between 2019 and 2022 were screened for the presence of virus-neutralizing antibodies against CDV, CAV-2, CPV, and CPIV-5. The overall seropositivity rates for CDV, CAV-2, CPV, and CPIV-5 were 83.8%, 77.8%, 99.3%, and 82.0%, respectively. The protection rate against CPV was the highest (98.3%) and that against CAV-2 was the lowest (44.8%) in dog sera. Male and female dogs showed no significant differences in seropositivity rates. CDV and CPIV-5 seropositivity increased with age in dogs, and the highest incidence and seropositivity rates of CPV indicated that Korean dogs have been continuously exposed to wild CPV, and that CPV is a pathogen that urgently requires attention among canine viral diseases.

• KSBB Journal
• /
• 제22권5호
• /
• pp.282-287
• /
• 2007

The antiviral mechanism of KT5720 is known to inhibit the cAMP-dependent protein kinase (PKA), on the VSV infection in BHK-21 cell cultures. The virus inducted CPE (cell rounding) was almost completely suppressed by KT5720 at 5 uM. The inhibitor, however, did not affect the replication of the virus and the synthesis of viral macromolecules. Immunological studies showed the viral matrix (M) protein displayed intimate association with the cytoskeletal components and probably the cell rounding. KT5720, did not block the cytoskeletal disruption, while the cell rounding was suppressed. These observations suggest that the interaction between the viral M protein and the cytoskeletal components may not be enough to cause the morphological change of the cell. And, the KT5720-sensitive function may be involved in developing the VSV-induced CPE, but not essential for the virus replications.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제31권3호
• /
• pp.193-197
• /
• 2009

Background: Though it is clear that many types of viruses can infect the oral mucosa, its condition for infection is unclear. The purpose of this study was to analyze the conditions for viral infection of normal oral mucosa and explore the possibility of topical gene therapy to oral mucosa using a viral vector. Methods: Freshly taken fragments of the palate and the tongue of mice were used for organ culture. The specimens were exposed to green fluorescent protein (GFP)-adenoviral vector for 1 hour except for the control. Initial viral titer was $6.3{\times}10^{11}\;pfu/ml$ and the virus was diluted to working concentrations. The dilution ratio was 1:1,000 ($6.3{\times}10^8\;pfu/ml$), 1:10,000 ($6.3{\times}10^7\;pfu/ml$), and 1:100,000 ($6.3{\times}10^6\;pfu/ml$). They were then cultured on a stainless steel wire mesh in an organ culture dish. The specimens were stereoscopically examined every 24 hours for 6 days, after which they were fixed and analyzed through immunohistochemical methods Results: There was no visible expression in the control, $6.3{\times}10^6\;pfu/ml$, and $6.3{\times}10^7\;pfu/ml$ groups. Initial expression was observed at 24 hours after infection in both the palate and the tongue in $6.3{\times}10^8\;pfu/ml$ and the expression significantly increased until 3 days in the palate and 2 days in the tongue after infection (P<0.05). In both groups, the expression was mostly observed at the resection margin. Immunohistochemical studies showed that the epithelial cells were positive to GFP. Conclusion: The present study showed that topically applied adenovirus containing specific genetic information of GFP could successfully transduce GFP in normal oral epithelial cells at the resection margin in organ culture in terms of dose and exposure time.

• Tuberculosis and Respiratory Diseases
• /
• 제82권4호
• /
• pp.328-334
• /
• 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.

• BMB Reports
• /
• 제29권2호
• /
• pp.180-182
• /
• 1996

One of the essential functions of virus surface proteins is the recognition of specific receptors on target cell membranes, and cellular receptors play an important role in viral pathogenesis. But the earliest steps of hepatitis B virus (HBV) infection, such as hepatocyte receptor interaction with the virus, are poorly understood. Previous work has suggested an important role of the preS1 region of HBV envelope protein in mediating viral binding to hepatocytes. Although hepatitis B virus (HBV) infection appears to be initiated by specific binding of virions to cell membrane structures via one or potentially several viral surface proteins, data showing the identification or isolation of the HBV receptor (s) are not yet available. The receptor-like proteins on the plasma membrane surface of HepG2 cells that bind to PreS1 were separated and identified using affinity chromatography, and the amino-terminal amino acid sequences of the receptor-like proteins were determined.