• Pediatric Infection and Vaccine
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• v.4 no.1
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• pp.116-125
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• 1997

Purpose : Studies on the duration of immune response against Japanese encephalitis virus from recipients with JE vaccine (Nakayama-NIH strain) in Korea. Methods : To determinate the immune response and the duration of antibody against JE vaccine, 213 students were examined since 1994 using hemmaglutination inhibition test and plaque reduction neutralization test (PRNT). Results : 24 months after the first vaccination, haemmaglutination inhibition and neutralizing antibody maintained from the recipients 63.4% (>1:20) and 100% (>1:20), respectively. In April 1996, one dose booster to the same recipients those who were vaccinated in 1994, the GMT antibody for HI and PRNT titer were both increased from 1:11.6 to 1:13.2 and 1:275.7 to 1:348.1, respectively, after 6 months booster (after 30 months from the initial vaccination). This results showed that the antibody from the active immunity could be maintained more than 12 months after the initial vaccination. On the basis of these results, inactivated killed JE vaccine (Nakayama-NIH strain) using for preventing against JE purpose seems to produce antibody enough to protect against JE at present. Conclusions : Along with the results of this study demonstrating duration of antibody, the active immunization could be maintained as long as by initial vaccination of 2 doses, a single dose of booster vaccination made during a period of 1 month to 12 months and the successive booster vaccination by 2 or 3 year intervals. However, the immunization schedule should be concerned with both epidemiology of disease and the immune response of vaccinated individuals.

• Pediatric Infection and Vaccine
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• v.27 no.2
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• pp.102-110
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• 2020

Purpose: This study aimed to investigate the clinical characteristics of human parechovirus (HPeV) infection in sepsis-like syndrome in infants aged under 3 months. Methods: Medical records of infants aged under 3 months with sepsis-like symptoms who were admitted between July 1, 2018 and August 31, 2018 were reviewed. A multiplex reverse transcription-polymerase chain reaction panel test was performed on the cerebrospinal fluid (CSF). Thirty-nine enrolled infants were categorized into three groups: 11 in group 1 (HPeV detected in the CSF), 13 in group 2 (enterovirus detected in the CSF), and 15 in group 3 (no virus detected in the CSF). Results: Compared with groups 2 and 3, a higher proportion of group 1 had tachycardia, tachypnea, apnea, and hypotension (P<0.05). A significantly lower white blood cell (WBC) count was noted in group 1 than in groups 2 and 3 (5,622±2,355/μL, 9,397±2,282/μL, and 12,312±7,452/μL, respectively; P=0.005). The CSF WBC count was lower in group 1 than in groups 2 and 3 (0.9±1.7/μL, 85.1±163.6/μL, and 3.7±6.9/μL, respectively; P=0.068). The proportion of patients requiring inotrope support (36.6% vs. 0% and 6.6%), mechanical ventilation (18.1% vs. 0% and 0%), and high flow nasal cannula (45.4% vs. 15.3% and 6.6%) was higher in group 1 than in groups 2 and 3. All patients recovered completely without complications. Conclusions: HPeV infection shows a severe clinical course and can cause a severe sepsis-like syndrome in infants aged under 3 months. Early diagnosis and proper treatment of HPeV infection are required.

• Pediatric Infection and Vaccine
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• v.23 no.3
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• pp.165-171
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• 2016

Purpose: Human parechovirus (HPeV) is an increasingly recognized pathogenic cause of central nervous system (CNS) infection in neonates. However, HPeV infections have not been studied in older children. This study determined the prevalence and clinical features of HPeV CNS infection in children in Korea. Methods: Reverse transcription polymerase chain reaction assays were performed using HPeV-specific, 5' untranslated, region-targeted primers to detect HPeV in cerebrospinal fluid (CSF) samples from children presenting with fever or neurologic symptoms from January 1, 2013, to July 31, 2014. HPeV genotyping was performed by sequencing the viral protein 3/1 region. Clinical and laboratory data were retrospectively abstracted from medical records and compared with those of enterovirus (EV)-positive patients from the same period. Results: Of 102 CSF samples, six (5.9%) were positive for HPeV; two of 21 EV-positive samples were co-infected with HPeV. All samples were genotype HPeV3. Two HPeV-positive patients were <3 months of age and four others were over 1 year old. While HPeV-positive infants under 1 year of age presented with sepsis-like illness without definite neurologic abnormalities, HPeV-positive children over 1 year of age presented with fever and neurologic symptoms such as seizures, loss of consciousness, and gait disturbance. The CSF findings of HPeV-positive patients were mostly within the normal range, whereas most (73.7%) EV-positive patients had pleocytosis. Conclusions: Although HPeV is typically associated with disease in young infants, the results of this study suggest that HPeV is an emerging pathogen of CNS infection with neurologic symptoms in older childhood.

• The Journal of the Korean Society for Microbiology
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• v.35 no.2
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• pp.191-201
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• 2000

The viruses of Herpes Simplex Virus 1 (HSV-1), Herpes Simplex Virus 2 (HSV-2) and Varicella-Zoster virus (VZV) which belong to the alpha herpes subfamily are important human pathogens. When eruptions were not fully developed from these viral infections, clinical diagnosis was not always easy and required virological confirmation test. The above viruses were reactivated in individuals who were compromised in immune competence for one reason or another. Polymerase chain reaction (PCR) enables rapid and sensitive detection of HSV and VZV DNAs. Its sensitivity was largely influenced by choice of primers. Authors conducted a study to detect of those three viruses in human specimens including vesicle fluid and joint fluid and serum using PCR methods. Primers used for this study were the general primer pair GPHV-RU which was known to amplify within the genes enjoying the highest degree of homology between UL15 of HSV and UL42 of VZV. PCR with primers hybridized pair GPHV-RU amplifies a 396 bp with THP-1 and HSV-2 standard strain DNA and 405 bp with VZV standard strain DNA. Restriction enzyme cleavage with HpaII and DdeI were used to detect and distinguish DNAs of THP-1 and HSV-2 and VZV. The purpose of this study was a rapid and easy detection of VZV and THP-1 or HSV-2 from various clinical specimens (vesicle fluid, serum and joint fluid) by PCR method. Used methods were: HSV PCR with primer 1, 2 and HpaII RE digestion; VZV nested PCR; HSV PCR with primer A, Band BssHII RE digestion. 1) In 33 cases (33/42, 78.6%) VZV was detected single or mixed infection from 42 clinical specimens which included vesicle fluid (5), serum form respiratory infected children (10), serum from immune suppressed adult cancer patients (7) and joint fluid from arthritis patients (20). 2) In 20 cases (20/42, 47.6%) HSV was detected singly or mixed infection and 19 of those cases were HSV-2 and 1 case was THP-1. 3) In 19 cases (19/42, 45.2%) VZV was singly detected which included serum from respiratory infected children (6 cases), joint fluid from arthritis patients (9 cases), vesicle fluid (2 cases) and serum form immunosuppressed cancer patients (2 cases). 4) HSV was singly detected in 6 cases (6/42, 14.3%) which included joint fluid from arthritis patients (5 cases) and serum form respiratory infected children (1 cases). 5) 14 cases of VZV and HSV mixed infection (14/42, 33.3%) were detected. They included vesicle fluid (3 cases), serum form immunosuppressed cancer patients (4 cases), serum from respiratory infected children (2 cases) and joint fluid from arthritis patients (5 cases). 6) HSV-1 and HSV-2 detection and typing by HSV PCR with primer A, Band BssHII RE digestion method was more sensitive and the results were easier to detect than on other method.

• Pediatric Infection and Vaccine
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• v.16 no.2
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• pp.142-149
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• 2009

Purpose : The aim of this study was to determine the diagnostic value of serum procalcitonin (PCT) compared with that of C-reactive protein (CRP) and the total white blood cell count (WBC) in predicting bacterial infections in febrile infants<6 months of age. Methods : A prospective study was performed with infants <6 months of age who were admitted to the Department of Pediatrics with a fever of uncertain source between July and September 2008. Spinal taps were performed according to clinical symptoms and physical examination. Serum PCT levels were measured using an enzyme-linked fluorescent assay. Results : Seventy-one infants (mean age, 2.62 months) were studied. Twenty-six infants (36.6%) had urinary tract infections (UTIs), and 22 infants (31.0%) had viral meningitis. The remaining infants had acute pharyngitis (n=1), herpangina (n=1), upper respiratory tract infections (n=7), acute bronchiolitis (n=8), acute gastroenteritis (n=4), and bacteremia (n=2). The median WBC and CRP levels were significantly higher in infants with UTIs than in infants with viral meningitis. However, there were no differences in the median PCT levels between the groups (0.14 ng/mL vs. 0.11 ng/mL, P=0.419). The area under the receiver operating characteristic curve was 0.792 (95% CI, 0.65-0.896) for WBC, 0.77 (95% CI, 0.626-0.879) for CRP, and 0.568 (95% CI, 0.417-0.710) for PCT. An elevated WBC count (>11,920/${\mu}L$) and an increased CRP level (>1.06mg/dL) were significant predictors of UTIs based on multiple logistic regression analysis. Conclusion : Serum PCT concentrations should be interpreted with caution in infants <6 months of age with a fever of uncertain source.

• Journal of Life Science
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• v.24 no.1
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• pp.86-91
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• 2014

Trichoplusia ni cells are used as a host permissive cell line in the baculovirus expression system, which is useful for large-scale production of human sugar transport proteins. However, the activity of endogenous sugar transport systems in insect cells is extremely high. Therefore, the transport activity resulting from the expression of exogenous transporters is difficult to detect. Furthermore, very little is known about the nature of endogenous insect transporters. To exploit the expression system further, the effect of D-fructose on 2-deoxy-D-glucose (2dGlc) transport by T. ni cells was investigated, and T. ni cell-expressed human transporters were photolabeled with [$^3H$] cytochalasin B to develop a convenient method for measuring the biological activity of insect cell-expressed transporters. The uptake of 1 mM 2dGlc by uninfected- and recombinant AcMPV-GTL infected cells was examined in the presence and absence of 300 mM of D-fructose, with and without $20{\mu}M$ of cytochalasin B. The sugar uptake in the uninfected cells was strongly inhibited by fructose but only poorly inhibited by cytochalasin B. Interestingly, the AcMPV-GTL-infected cells showed an essentially identical pattern of transport inhibition, and the rate of 2dGlc uptake was somewhat less than that seen in the non-infected cells. In addition, a sharply labeled peak was produced only in the AcMPV-GTL-infected membranes labeled with [$^3H$] cytochalasin B in the presence of L-glucose. No peak of labeling was seen in the membranes prepared from the uninfected cells. Furthermore, photolabeling of the expressed protein was completely inhibited by the presence of D-glucose, demonstrating the stereoselectivity of labeling.

• Pediatric Infection and Vaccine
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• v.25 no.3
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• pp.156-164
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• 2018

Purpose: We aimed to identify the epidemiology and the clinical characteristics of human parainfluenza virus type 4 (HPIV-4) infection compared to HPIVs 1-3 infections in Korean children. Methods: We reviewed medical records of children with HPIV infection who visited Seoul National University Children's Hospital from 2015 to 2017. Detection of respiratory viruses was performed using real time-polymerase chain reaction (rt-PCR), which could differentiate HPIVs 1-4. Diagnosis was classified as a febrile illness, upper respiratory tract infection (URI), croup, bronchiolitis, or pneumonia. The epidemiology, demographic features, and clinical characteristics among HPIV types were compared. The clinical data were analyzed only for the previously healthy children. Results: Of the 472 children diagnosed with HPIV infection, 108 (22.9%) were previously healthy: 24 (22.2%), 19 (17.6%), 39 (36.1%), and 26 (24.1%) in HPIV types 1, 2, 3, and 4, respectively. The median age of children with HPIV-4 infection was 11 (0-195) months: the proportion of children aged < 2 years and 2 to < 5 years were 65.4% and 19.2%, respectively. Clinical diagnoses of HPIV-4 infection were bronchiolitis (38.5%), pneumonia (30.8%), and URI (30.8%). Croup was the most prevalent in HPIV-2 (21.1%) and none in HPIV-4 infection (P=0.026). Hospital admission rates among HPIV types were not significantly different (P>0.05). Conclusions: We observed seasonal peak of HPIV-4 infection in 2015 and 2017. HPIV-4 was a common respiratory pathogen causing lower respiratory tract infection in hospitalized children.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.449-456
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• 2018

Cervical cancer is the fourth most frequently diagnosed cancer in women worldwide. In lower Human Development Index countries, it has the second highest incidence and mortality among cancer in women. Therefore, better diagnosis and treatment systems are needed. Among them, estrogen receptor alpha ($ER-{\alpha}$) mRNA expression has been analyzed with RT-qPCR since several studies reported that $ER-{\alpha}$ is necessary in the maturation of the uterus and is related to cervical cancer. In this study, $ER-{\alpha}$ quantitative analysis was performed on various lesions and normal tissue samples. Based on the receiver operating characteristic (ROC) curve, its sensitivity and specificity were 85% and 75%, respectively, showing higher or similar results to those of conventional HPV tests. In addition, its expression level was analyzed with clinical information. With regression analysis, the R square value between the $ER-{\alpha}$ mRNA expression level and menopause status was 0.5041, indicating a strong correlation. This study was performed as part of a pilot study and suggests that $ER-{\alpha}$ is related to carcinogenesis. Future studies will examine other hormones and menopausal factors with a larger sample size.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.4
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• pp.218-227
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• 2006

Purpose: The HSV1-tk reporter gene system is the most widely used system because of its advantage that direct monitoring is possible without the introduction of a separate reporter gene in case of HSV1-tk suicide gene therapy. In this study, we investigate the usefulness of the reporter probe (substrate), $9-(4-[^{18}F]Fluoro-3-hydroxymethylbutyl)$guanine ($[^{18}F]FHBG$) for non-invasive reporter gene imaging using PET in HSV1-tk expressing hepatoma model. Materials and Methods: Radiolabeled FHBG was prepared in 8 steps from a commercially available triester. The labeling reaction was carried out by NCA nucleophilic substitution with $K[^{18}F]/K2.2.2.$ in acetonitrile using N2-monomethoxytrityl-9-14-(tosyl)-3-monomethoxytritylmethylbutyl]guanine as a precursor, followed by deprotection with 1 N HCl. Preliminary biological properties of the probe were evaluated with MCA cells and MCA-tk cells transduced with HSV1-tk reporter gene. In vitro uptake and release-out studies of $[^{18}F]FHBG$ were performed, and was analyzed correlation between $[^{18}F]FHBG$ uptake ratio according to increasing numeric count of MCA-tk cells and degree of gene expression. MicroPET scan image was obtained with MCA and MCA-tk tumor bearing Balb/c-nude mouse model. Results: $[^{18}F]FHBG$ was purified by reverse phase semi-HPLC system and collected at around 16-18 min. Radiothemical yield was about 20-25%) (corrected for decay), radiochemical purity was >95% and specific activity was around >55.5 $GBq/{\mu}\;mol$. Specific accumulation of $[^{18}F]FHBG$ was observed in HSV1-tk gene transduced MCA-tk cells but not in MCA cells, and consecutive 1 hour release-out results showed more than 86% of uptaked $[^{18}F]FHBG$ was retained inside of cells. The uptake of $[^{18}F]FHBG$ was showed a highly significant linear correlation ($R^2=0.995$) with increasing percentage of MCA-tk numeric cell count. In microPET scan images, remarkable difference of accumulation was observed for the two type of tumors. Conclusion: $[^{18}F]FHBG$ appears to be a useful as non-invasive PET imaging substrate in HSV1-tk expressing hepatoma model.

• Journal of fish pathology
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• v.26 no.2
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• pp.111-116
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• 2013

In this study, the disinfectant efficacy of Aqua farmsafe$^{(R)}$, composed of didecyldimethylammonium chloride (DDAC) and yucca extract was evaluated against Salmonella typhimurium and fish pathogens. Determination of the anti-microbial or anti-viral efficacy of the disinfectant was based on Animal, Plant and Fisheries Quarantine and Inspection Agency Regulation No. 2011-26, Korea. Anti-bacterial efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to test bacteria for 30 min at $4^{\circ}C$. Aqua farmsafe and test bacteria or virus were diluted with distilled water (DW), standard hard water (SW) or organic matter dilution (OM) according to treatment condition. Under the our results, disinfectant efficacy of Aqua farmsafe$^{(R)}$ possesses 30~40 fold against fish pathogens including bacteria and virus compared to that on animal pathogenic bacteria, S. typhimurim. As the efficacy of Aqua farmsafe$^{(R)}$ against fish pathogen was investigated in vitro, a controlled field trial is required to determine whether the use of Aqua farmsafe$^{(R)}$ will be able to reduce fish diseases.