• Pediatric Infection and Vaccine
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• v.30 no.2
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• pp.73-83
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• 2023

Purpose: This study aimed to investigate the viral load dynamics in children with underlying malignancies diagnosed with symptomatic coronavirus disease 2019 (COVID-19). Methods: This was a retrospective longitudinal cohort study of patients <19 years old with underlying hemato-oncologic malignancies that were diagnosed with their first symptomatic severe acute respiratory syndrome coronavirus 2 polymerase chain reaction (PCR)-confirmed COVID-19 infection during March 1 to August 30, 2022. Review of electronic medical records and telephone surveys were undertaken to assess the clinical presentations and transmission route of the patients. Thresholds of negligible likelihood of infectious virus was defined as E gene reverse transcription (RT)-PCR cycle threshold (Ct) value ≥25. Results: During the 6-month study period, a total of 43 children with 44 episodes of COVID-19 were included. Of the 44 episodes, the median age of the patients included was 8 years old (interquartile range [IQR], 4.9-10.5), and the most common underlying disease was acute lymphoid leukemia (n=30, 68.2%), followed by patients post-hematopoietic stem cell transplantation (n=8, 18.2%). Majority of the patients had mild COVID-19 (n=32, 72.7%), and three patients (7.0%) had severe/critical COVID-19. Furthermore, 2.3% (n=1) died of COVID-19 associated acute respiratory distress syndrome. The largest percentage of the patients showed E gene RT-PCR Ct value ≥25 between 15-21 days (n=13, 39.4%), followed by 22-28 days (n=10, 30.3%). In 15.2% (n=5), E gene RT-PCR Ct value remained <25 beyond 28 days after initial positive PCR. Refractory malignancy status (β, 67.0; 95% confidence interval, 7.0-17.0; P=0.030) was significantly associated with prolonged duration of E gene RT-PCR <25. A patient with prolonged duration of E gene RT-PCR Ct value <25 was suspected to have infectivity shown by the transmission of the virus to his mother at day 86 after his initial positive test. Conclusions: Children that acquire symptomatic COVID-19 during refractory malignancy state are at a high risk for prolonged shedding warranting PCR-based transmission precautions in this cohort of patients.

• The Journal of Korean Society of Virology
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• v.26 no.2
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• pp.251-258
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• 1996

The V3 loop, a hypervariable domain of envelope glycoprotein, has an essential role in viral infectivity and has a major epitope for type-specific neutralizing antibody. In order to investigate genetic diversity of V3 region of gp120 of human immunodeficiency virus type 1 (HIV-1) isolated from Korean patients, DNA sequences encoding the C2 to V3 region were amplified by nested polymerase chain reaction (PCR) from uncultured peripheral blood mononuclear cells obtained from 15 HIV-1 seropositive patients and nucleotide sequences were determined. All nucleotide sequences from fifteen patients were compared with 8 distinctive subtypes (A-H) and another subtype O. Phylogenetic analysis was carried out with PHYLIP ver 3.5 (Dnapars) program. Of the 15 isolates, 14 HIV-1 subjects were clustered with subtype B, while one was clustered with subtype C. Intra-subtype B distance at the nucleotide and deduced amino acid level were maximum 17.7% and 37.0%, respectively. Intra-patient distance at the nucleotide and deduced amino acid level were maximum 7.3% and 17.8%, respectively. Analysis of the nucleotide sequences revealed that Korean types have relatively well conserved sequences. These findings could be useful for assessing the source of infection and developing an AIDS vaccine.

• BMB Reports
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• v.34 no.1
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• pp.80-84
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• 2001

The human papillomavirus E7 protein can form a specific complex with a retinoblastoma tumor suppressor gene product (p105-Rb) that results in the release of the E2F transcription factor, which is critical for the growth-deregulation and transforming properties of the viral E7 oncoprotein. In an attempt to apply interaction between the E7 oncoprotein and a target cellular protein Rb for an in vitro screening system for drugs against human papillomavirus infection, we primarily investigated the E7Rb binding through a pull down assay and enzyme-linked immunosorbent assay. The pull down assay showed that both glutathione S-transferase-tagged E7 and His-tagged E7 immobilized on resins specifically produced complexes with bacterially expressed Rb in a dose-dependent manner, as determined by immunoblot analyses. This result coincided with that of an enzyme-linked immunosorbent assay, which is a useful system for the mass screening of potential drugs. Taken together, this screening system (based on the interaction between E7 and Rb) can be a promising system in the development of drugs against cervical cancers caused by human papillomavirus infection.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.482-490
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• 2001

The gene for glycoprotein B (gB2) of HSV-2-strain G was subcloned, sequenced, recombinated into the lacZ-HcNPV, expressed in insect cells, and compared with the homologous gene of other HSV-2 strains. The ORF of the gB2 gene was 2,715 bp. The overall nucleotide sequence homology of te gB2 gene compared ith that of the two previously reported HSV-2 strains appeared to be over 98%. A recombinant virus named Baculo-gB2 protein in insect cells. The recombination was confirmed by a PCR and the expression was demonstrated by radio immunoprecipitation. Insect cells infected with the Baculo-gB2 virus synthesized and processed gB2 with approximately 120 kDa in the cells, and then secreted it into the culture media, where it reacted with a nomoclonal antibody to gB2. The gB2 polypeptide contained two main hydrophobic regions (a signal sequence from 1 to 23 amino acid residues, and a membrane anchor sequence from aa 745 to 798), eight N-glycosylation sites evenly distributed, and was rich in alanine (11.2%). Antibodies to this recombinant protein that were raised in mice recognized the viral gB2 and neutralized the infectivity of the HSV-2 in vitro. There results show that the gB2 protein was successfully porduced in insect cells and could be used to raise a protective neutralizing antibody. Accordingly, this particular recombinant protein may be useful in the development of a subunit vaccine.

• Journal of Ginseng Research
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• v.28 no.4
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• pp.173-182
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• 2004

We have shown that long-term intake of Korean red ginseng (KRG) delays disease progression in HIV-I infected patients. In the present study to investigate whether this slow progression was associated with protective human leukocyte antigen (HLA) alleles as well as with KRG-intake, we have performed clinical analysis of 31 HIV-1 infected patients who have been living for more than 10 years without any antiretroviral therapy. Average amount of KRG-intake over $130\;{\pm}16$ months was $4,797\;{\pm}4,921\;g$ and the annual decrease in CD4 T cell (AD) was $30\;{\pm}29{\mu}L$. We observed significant correlations among amount of KRG-intake, AD(r=-0.53, P < 0.01), and plasma HIV-1 RNA copy (r=-0.35, P < 0.05), along with a significant correlation between KRG-intake and HLA score AD(r=-0.49, P < 0.01), whereas there was no significant correlation between HLA score and AD or viral load. When the 31 patients were divided into 2 groups based on the amount of KRG-intake, the $AD(14/{\mu}L)$ in the 16 patients who had taken higher amounts of KRG was significantly less than that $(49/{\mu}L)$ in the 15 patients with a little or no KRG-intake (P < 0.01). These data indicate that KRG-intake sig­nificantly slows CD4 T cell depletion in HIV-1 infected patients.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.176-183
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• 2016

In this study, disease surveillance was performed to monitor the prevalence of viral haemorrhagic septicaemia virus (VHSV) and red seabream iridovirus (RSIV) in olive flounder, Paralichthys olivaceus in 2015. The fish samples were collected in March (60 farms), May (55 farms) and July (52 farms) from different farms in Jeju. Reverse transcription polymerase chain reaction (RT-PCR) (VHSV) or PCR (RSIV) results showed that VHSV detected in 2 farms, but RSIV has not been detected in any farms. The sequences of the nucleocapsid protein (N) and glycoprotein (G) gene of the 2 VHSV isolates were successfully sequenced. Phylogenetic analysis was included VHSV isolates reported here together with a representative VHSV isolates available in GenBank. Phylogenetic analysis indicated that most of Korea VHSV isolates were closely related to the Japan and China genotype IVa which is clearly distinct from the North American genotype IVb.

• Pediatric Infection and Vaccine
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• v.3 no.1
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• pp.76-85
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• 1996

Adenoviruses(Ad) are considered to be second only to rotaviruses as the most significant cause of gastroenteritis in young children in Korea and thus it is essential to know the full spectrum of Ad serotypes routinely present in stool specimens from symptomatic patients. Sixty-six Ad isolates and three questionable ones collected over a 2-year peiord were typed by standard microneutralization, restriction endonuclease digestion and PCR of viral DNA to be able to evaluate these assays comprehensively for their ability to identify Ad associated with gastroenteritis. A total of sixty-one isolates(88.4%) were typed: the predominant types were Ad type 41(Ad41)(26.2%), Ad2(19.7%), Ad40(14.8%), Ad5(9.8%), and Ad7(9.8%) which together accounted for almost 80% of the isolates. The remaining virus isolates were typed as Ad1, 31, 34, 3, 25 and a mixture of 40/41. The incidence of Ad31(4.9%) or Ad3(1.6%) was relatively insignificant. DNA restriction analysis(77.5%) proved to be better than serum neutralization but not so when compared to a PCR-based assay for identification of the enteric Ad serotypes(90%) in stool specimens. In this work, the PCR-based assay was evaluated as a tool for the rapid, yet highly sensitive identification of adenoviral DNA sequences in fresh clinical stool specimens.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.25-30
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• 2001

Viral safety is a prerequisite for manufacturing clinical albumin and immunoglobulins from human plasma pools. This study was designed to evaluate the efficacy of cold ethanol fractionation and pasteurization (60$\^{C}$ heat treatment for 10h) for the removal/inactivation of human immunodeficiency virus type 1 (HIV-1) during the manufacturing of albumin and immunoglobulins. Samples from the relevant stages of the production process were spiked with HIV-1, and the amount of virus in each fraction was quantified by the 50% tissue culture infectious dose(TCID(sub)50). Both fraction IV fractionation and pasteurization steps during albumin processing were robust and effective in inactivating HIV-1, titers of which were reduced from an initial 8.5 log(sub)10 TCID(sub)50 to undetectable levels. The log reduction factors achieved were $\geq$ 4.5 and $\geq$ 6.5, respectively. In addition, fraction III fractionation and pasteurization during immunoglobulins processing were robust and effective in eliminating HIV-1. HIV-1 titers were reduced from an initial 7.3 log(sub)10 TCID(sub)50 to undetectable levels. The log reduction factors achieved in this case were $\geq$ 4.9 and $\geq$ 5.3, respectively. These results indicate that the process investigated for the production of albumin and immunoglobulins have sufficient HIV-1 reducing capacity to achieve a high margin of safety.

• Clinical and Experimental Pediatrics
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• v.61 no.9
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• pp.291-300
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• 2018

Purpose: Understanding changes in pathogen and pneumonia prevalence among pediatric pneumonia patients is important for the prevention of infectious diseases. Methods: We retrospectively analyzed data of children younger than 18 years diagnosed with pneumonia at 117 Emergency Departments in Korea between 2007 and 2014. Results: Over the study period, 329,380 pediatric cases of pneumonia were identified. The most frequent age group was 1-3 years old (48.6%) and the next was less than 12 months of age (17.4%). Based on International Classification of Diseases, 10th revision diagnostic codes, confirmed cases of viral pneumonia comprised 8.4% of all cases, pneumonia due to Mycoplasma pneumoniae comprised 3.8% and confirmed cases of bacterial pneumonia 1.3%. The prevalence of confirmed bacterial pneumonia decreased from 3.07% in 2007 and 4.01% in 2008 to 0.65% in 2014. The yearly rate of pneumococcal pneumonia also decreased from 0.47% in 2007 to 0.08% in 2014. A periodic prevalence of M. pneumoniae pneumonia (MP) was identified. Conclusion: The increased number of patients with pneumonia, bacterial pneumonia, pleural effusion, and empyema in 2011 and 2013-2014 resulted from an MP epidemic. We provide evidence that the frequency of confirmed cases of bacterial pneumonia and pneumococcal pneumonia has declined from 2007 to 2014, which can simultaneously reflect the effectiveness of the pneumococcal conjugate vaccine.

• Korean Journal of Poultry Science
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• v.38 no.1
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• pp.45-50
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• 2011

A case of aspergillosis in 39-day-old layer chickens having a history of gradual emaciation and subsequently death with nervous signs such as torticollis and lack of equilibrium was documented. Based on the results from serology and polymerase chain reaction (PCR) test, this flock was not affected with known viral or bacterial diseases. On postmortem examination of the affected birds, multiple white to yellow nodules measuring 1~5 mm in diameter were observed in the lungs, cerebrum, liver and kidney. Microscopically, these nodules were identified as granulomatous lesions characterized by mixed population of multinucleated giant cells and lymphocytes. By periodic acid-schiff staining and nucleotide sequencing analysis, Aspergillus flavus with characteristic septate and branched hyphae were identified in the granuloma of lung and cerebrum. This case was a chronic and multisystemic aspergillosis specialized to central nervous system caused by Aspergillus flavus infection in the layer flocks.