• IMMUNE NETWORK
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• v.16 no.5
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• pp.261-270
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• 2016

The human immune system has evolved to fight against foreign pathogens. It plays a central role in the body's defense mechanism. However, the immune memory geared to fight off a previously recognized pathogen, tends to remember an original form of the pathogen when a variant form subsequently invades. This has been termed 'original antigenic sin'. This adverse immunological effect can alter vaccine effectiveness and sometimes cause enhanced pathogenicity or additional inflammatory responses, according to the type of pathogen and the circumstances of infection. Here we aim to give a simplified conceptual understanding of virus infection and original antigenic sin by comparing and contrasting the two examples of recurring infections such as influenza and dengue viruses in humans.

• Pediatric Infection and Vaccine
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• v.25 no.1
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• pp.8-16
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• 2018

Purpose: In this study, the clinical and epidemiological characteristics of patients admitted for viral croup were analyzed to evaluate disease severity based on the organism that caused the infection. Methods: We retrospectively reviewed the medical records of 302 patients who were admitted to the Department of Pediatrics at the Wonju Severance Hospital between May 2013 and December 2016 for viral croup. Patients who showed positive results on multiplex polymerase chain reaction were subsequently diagnosed with respiratory virus infection. The Westley scoring system was used to evaluate the severity of viral croup. Results: Of the 302 patients, 149 were admitted due to severe viral croup, including 88 boys and 61 girls, with a boy-to-girl ratio of 1.44:1. About 110 cases of parainfluenza virus infection have been reported, which accounted for almost half of the total cases. The other identified viruses included influenza virus, human rhinovirus, and respiratory syncytial virus. Analysis of the association between severe viral croup and causative pathogen revealed that only parainfluenza type 2 virus showed a significantly high risk. Parainfluenza type 2 virus did not show an age-based difference in frequency but showed relatively a higher frequency of infections during the summer and fall. Conclusions: In this study, parainfluenza virus type 2 was the only virus associated with severe viral croup. To facilitate proper preventive management, treatment, and prognosis evaluation of viral croup, prospective and multicenter studies should assess the additional variables and the severity of the virus. Additionally, further studies should be conducted to assess age-dependent influences, as well as the regional and seasonal incidence of viral infection.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.4953-4960
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• 2013

Primary liver cancer is one of the most common cancers at the global level, accounting for half of all cancers in some undeveloped countries. This disease tends to occur in livers damaged through alcohol abuse, or chronic infection with hepatitis B and C, on a background of cirrhosis. Various cancer-causing substances are associated with primary liver cancer, including certain pesticides and such chemicals as vinyl chloride and arsenic. The strong association between HBV infection and liver cancer is well documented in epidemiological studies. It is generally acknowledged that the virus is involved through long term chronic infection, frequently associated with cirrhosis, suggesting a nonspecific mechanism triggered by the immune response. Chronic inflammation of liver, continuous cell death, abnormal cell growth, would increase the occurrence rate of genetic alterations and risk of disease. However, the statistics indicated that only about one fifth of HBV carries would develop HCC in lifetime, suggesting that individual variation in genome would also influence the susceptibility of HCC. The goal of this review is to highlight present level of knowledge on the role of viral infection and genetic variation in the development of liver cancer.

• Korean Journal of Organic Agriculture
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• v.23 no.1
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• pp.123-131
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• 2015

In this study, viral disease samples were obtained between 2006 and 2010 from pepper fields in 11 major pepper-growing districts in Gangwon-do, and in 83 areas from other provinces, with the exception of Gyeongsangnam-do and Jeju island in Korea. In order to assess the type of infection, field surveys were conducted with regard to viral disease severity and virus type, based on typical symptoms on leaves. The means of single and mixed-virus infections were 46.6% and 48.0%, respectively, during those periods, suggesting that viruses are the agents that most severely decrease pepper production in field cultivation in Korea. In terms of single infection, Cucumber mosaic virus (CMV) was the most prevalent virus based on its disease severity ratings (34.8%). Next, Pepper mild mottle virus (PMMoV) and Pepper mottle virus (PepMoV) were shown to cause severe viral diseases in pepper, with disease severities of around 5-10%. On the other hand, Tomato spotted wilt virus (TSWV) occurs in a limited area in Chungcheongnam-do and Jeollanam-do. Thus, the viral disease caused by CMV, PMMoV, and PepMoV in pepper can be severe, and these virus types should remain considered critical reasons for decreased pepper production in field cultivation in Korea. In addition to single infection, mixed infections are frequently observed in collected pepper samples from all areas. The ratios of mixed infection were therefore studied to evaluate the disease severity of mixed infections and to define individual virus types. These data showed that different types of viruses were present, and CMV was the most abundant virus for mixed infection, as in the case of single infection. Among mixed infections, the highest disease severity was seen with CMV+Broad beam wilt virus 2 (BBWV2), followed by other types of mixed infection such as CMV+PepMoV and CMV+PMMoV. However, further work is needed to reduce the severe damage caused by viruses and to assess mixed infection types involving three or more viruses.

• 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.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.18 no.4
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• pp.317-335
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• 2014

In this work, we investigate the global stability analysis of a viral infection model with antibody immune response. The incidence rate is given by a general function of the populations of the uninfected target cells, infected cells and free viruses. The model has been incorporated with two types of intracellular distributed time delays to describe the time required for viral contacting an uninfected cell and releasing new infectious viruses. We have established a set of conditions on the general incidence rate function and determined two threshold parameters $R_0$ (the basic infection reproduction number) and $R_1$ (the antibody immune response activation number) which are sufficient to determine the global dynamics of the model. The global asymptotic stability of the equilibria of the model has been proven by using Lyapunov theory and applying LaSalle's invariance principle.

• IMMUNE NETWORK
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• v.3 no.1
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• pp.29-37
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• 2003

Background: CC chemokine receptor (CCR) 7 and cognate CCR7 ligands, CCL21 (formerly secondary lymphoid tissue chemokine [SLC]) and CCL19 (formerly Epstein-Barr virus-induced molecule 1 ligand chemokine [ELC]), were known to establish microenvironment for the initiation of immune responses in secondary lymphoid tissue. As described previously, coadministration of DNA vaccine with CCR7 ligand-encoding plasmid DNA elicited enhanced humoral and cellular immunity via increasing the number of dendritic cells (DC) in secondary lymphoid tissue. The author hypothesized here that CCR7 ligand DNA could effectively expand memory CD4+ T cells to protect from viral infection likely via increasing DC number. Methods: To evaluate the effect of CCR7 ligand DNA on the expansion of memory CD4+ T cells, DO11.10.BALB/c transgenic (Tg)-mice, which have highly frequent ovalbumin $(OVA)_{323-339}$ peptide-specific CD4+ T cells, were used. Tg-mice were previously injected with CCR7 ligand DNA, then immunized with $OVA_{323-339}$ peptide plus complete Freund's adjuvant. Subsequently, memory CD4+ T cells in peripheral blood lymphocytes (PBL) were analyzed by FACS analysis for memory phenotype ($CD44^{high}$ and CD62 $L^{low}$) at memory stage. Memory CD4+ T cells recruited into inflammatory site induced with OVA-expressing virus were also analyzed. Finally, the protective efficacy against viral infection was evaluated. Results: CCR7 ligand DNA-treated Tg-mice showed more expanded $CD44^{high}$ memory CD4+ T cells in PBL than control vector-treated animals. The increased number of memory CD4+ T cells recruited into inflammatory site was also observed in CCR7 ligand DNA-treated Tg-mice. Such effectively expanded memory CD4+ T cell population increased the protective immunity against virulent viral infection. Conclusion: These results document that CCR7 and its cognate ligands play an important role in intracellular infection through establishing optimal memory T cell. Moreover, CCR7 ligand could be useful as modulator in DNA vaccination against viral infection as well as cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1755-1760
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• 2013

Objective: To investigate the prevalence of genital high-risk human papillomavirus (HR-HPV) in male sexual partners of HR-HPV infected women and the concordance of viral types in couples in China, and comprehend the role of men play in HPV transmission to women. Methods/Materials: 94 asymptomatic women and their husbands from rural Chaozhou participated in epidemiologic screening for HPV infection. Cervical cells from females were collected for high risk HPV screening by real time-PCR, and they were positive for at least 1 of 13 HR-HPV subtypes, then these samples were genotyped. Approximately one mouth later, penile epithelial cells from 94 asymptomatic husbands were collected for HPV genotyping. At the same time, a cross-sectional study was conducted in 366 male patients from sexually transmitted disease (STD) outpatient clinic in China for the prevalence of genital HR-HPV infection in men having frequent sex behavior. Penial epithelial cells were collected for HPV 6/11 and HPV 16/18 detection by fluorescent real-time quantified PCR. Results: Among 94 couples, the prevalence of genital HR-HPV infection in men whose wife was positive for cervical HR-HPV was 5.32% (5/94). Only 2.63% (2/76) had the same high risk viral type presented by their wife. HPV 16 proved to be the most prevalent viral type in men and in couples. Of 366 male patients from STD outpatient clinic, the prevalence of HPV 16/18 infection in men with or without HPV 6/11 was 6.85% and 8.16%, respectively. The incidence of HPV 16/18 was higher in men aged more than 35 years than the young men (18-35 years). Conclusion: The prevalence of genital HR-HPV infection in male sexual partners of HPV-positive women in China was lower than that expected, and the concordance of high risk viral type between couples was extremely low. These data suggested that infected men consitute an important viral reservoir, contributing to transmission of HR-HPV to women and maintenance of infection, but HR-HPV infection may be less likely to persist in men than in women.

• The Journal of Korean Society of Virology
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• v.29 no.1
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• pp.1-9
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• 1999

Hantaan virus is widely distributed among rodent populations in Korea. Two antigenically distinct hantaviruses were isolated from Apodemus agrarius in 1976 and Rattus norvegicus in 1980 in Korea. This study was designed to investigate the serological evidence of hantavirus infection among indegenous wild rodents, which were captured in 11 mountains located in Kyunggi, Kangwon, Chungnam, Chunbug and Kyungnam province of South Korea. A total 252 wild rodents of 3 species were trapped from Myungsung Mt., Chumbong Mt., Kali Mt., Hansuk Mt., Chachil peak, Kyebang Mt., Odae Mt., Kyerong Mt., Kaya Mt., Togju Mtand Chiri Mtin 1997. Serologic test for hantavirus infection was performed using hantavirus antigens by indirect immunofluorescent antibody techniqueAmong 122 Apodemus agrarius, 88 Apodemus peninsulae and 42 Eothenomys regulus; 18 A. agrarius (14.8%), 12 A. peninsulae (13.6%) and 4 E. regulus (9.5%) were immunofluorescent antibody (IFA) positive against hantaan virus. IFA titers 3 Eothenomys regulus sera were higher against puumalavirus than hantaan virus. These data imply that above three species of rodent might be natural reservoirs of hantaviruses in Korea.

• The Journal of Korean Society of Virology
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• v.28 no.3
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• pp.287-293
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• 1998

Hantaan virus are widely distributed in rodents populations in Korea. Two antigenically distinct hantaviruses have been isolated from Apodemus agrarius in 1976 and Rattus norvegicus in 1980 in Korea. This study was designed to find the serological evidence of hantavirus infection among indigenous wild rodents captured in 7 Mountains located in Kangwon province of south Korea. A total 191 wild rodents of 3 species were trapped in Chumbong mountain, Kali mountain, Hansuk mounatin, Chachil peak, Bukam ridge, Kyebang mountain and Odae mountain in 1997. Serologic evidence for hantavirus infection were tested using hantavirus antigens by indirect immunofluorescent antibody technique (IFA). Among 85 Apodemus agrarius, 77 Apodemus peninsulae and 29 Eothenomys regulus; 8 A. agrarius (9.4%), 11 A. peninsulae (14.3%) and 4 E. regulus (13.8%) were immunofluorescent antibody positive against hantaan virus. IF antibody titers against Puumala virus of 3 E. regulus sera were higher than against hantaan virus. This data suggest that several antigenically distinct hantaviruses have been circulated in rodent populations in Korea.