• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.2
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• pp.109-112
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• 2006

The use of commercial silkworm hybrids resistant to important silkworm diseases is economical and better option particularly in tropical areas. This necessitated the evolution of productive bivoltine silkworm breeds non-susceptible to $BmDNV_1$. Non-susceptibility to $BmDNV_1$, infection was found to be controlled by a single recessive gene, nsd-l or a dominant gene, Nid-l. A major dominant/recessive gene confers resistance to $BmDNV_1$, from potent donor parents have been transferred to 10 productive but susceptible bivoltine silkworm strains through conventional breeding methods. By utilizing these breeds prepared 25 hybrids $(5{\times}5)$ and hybrid evaluation was carried out to identify most promising hybrids resistant to $BmDNV_1$. All these hybrids are inoculated with $BmDNV_1$ inoculum along with productive control hybrid $CSR2{\times}CSR4$ and reared under standard rearing procedure. Based on inoculated rearing and test reeling results, two most promising hybrids $(CSR18DR{\times}CSR29DR\;and\;CSR21DR{\times}CSR50DR)$ were selected for commercial exploitation. The selected hybrids have shown a survival rate of >85% with productive traits, where as control hybrid have shown 11.1% survival with inferior cocoon traits. The methodologies adopted were discussed.

• Genomics & Informatics
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• v.21 no.2
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• pp.26.1-26.9
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• 2023

Stevens-Johnson syndrome (SJS) produces a severe hypersensitivity reaction caused by Herpes simplex virus or mycoplasma infection, vaccination, systemic disease, or other agents. Several studies have investigated the genetic susceptibility involved in SJS. To provide further genetic insights into the pathogenesis of SJS, this study prioritized high-impact, SJS-associated pathogenic variants through integrating bioinformatic and population genetic data. First, we identified SJS-associated single nucleotide polymorphisms from the genome-wide association studies catalog, followed by genome annotation with HaploReg and variant validation with Ensembl. Subsequently, expression quantitative trait locus (eQTL) from GTEx identified human genetic variants with differential gene expression across human tissues. Our results indicate that two variants, namely rs2074494 and rs5010528, which are encoded by the HLA-C (human leukocyte antigen C) gene, were found to be differentially expressed in skin. The allele frequencies for rs2074494 and rs5010528 also appear to significantly differ across continents. We highlight the utility of these population-specific HLA-C genetic variants for genetic association studies, and aid in early prognosis and disease treatment of SJS.

• Journal of Korean Biological Nursing Science
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• v.25 no.4
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• pp.266-275
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• 2023

Purpose: Although long-term viral suppression and antiretroviral therapy (ART) success depend on sustained adherence, adolescents' adherence rates are suboptimal. Optimal adherence is influenced by various factors. Since Sub-Saharan Africa is home to over 80% of adolescents living with human immunodeficiency virus (HIV) and considering their unique characteristics and susceptibility to poor adherence, it is crucial to provide updated knowledge on adherence rates and their determinants among this population. This review aims to present up-to-date data on adherence rates and associated factors among HIV-positive adolescents in Sub-Saharan Africa. Methods: A systematic review was conducted following the PRISMA guidelines. The PubMed and Scopus databases were used to identify documents corresponding to the study's objectives. Eleven studies were included in this review after being selected from among all studies that were found online from 2017 to 2023. Results: The reported adherence rates ranged from 55% to 86%. In total, 32 factors were found to be related to adherence among HIV-positive adolescents in Sub-Saharan Africa. These included 12 adherence-facilitating factors and 20 adherence-inhibiting factors. The most often mentioned factors affecting adherence were advanced World Health Organization clinical stage (i.e., stage IV), ART dose and regimens, a lack of support, and violence victimization. Conclusion: Our findings can help healthcare providers collaborate with HIV-positive adolescents to improve ART adherence and ensure the best possible health outcomes.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10209-10215
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• 2015

To assess the contribution of tumor necrosis factor $(TNF){\beta}$ +252 polymorphisms to risk and prognosis of hepatocellular carcinoma (HCC), we enrolled 150 pairs of sex- and age-matched patients with HCC, patients with cirrhosis alone, and unrelated healthy controls. $TNF{\beta}$ +252 genotypes were determined by polymerase chain reaction with restriction fragment length polymorphism. Multivariate analysis indicated that $TNF{\beta}$ G/G genotype [odds ratio (OR), 3.64; 95%CI, 1.49-8.91], hepatitis B surface antigen (OR, 16.38; 95%CI, 8.30-32.33), and antibodies to hepatitis C virus (HCV) (OR, 39.11; 95%CI, 14.83-103.14) were independent risk factors for HCC. There was an additive interaction between $TNF{\beta}$ G/G genotype and chronic hepatitis B virus (HBV)/HCV infection (synergy index=1.15). Multivariate analysis indicated that factors associated with $TNF{\beta}$ G/G genotype included cirrhosis with Child-Pugh C (OR, 4.06; 95%CI, 1.34-12.29), thrombocytopenia (OR, 6.55; 95%CI, 1.46-29.43), and higher serum ${\alpha}$-fetoprotein concentration (OR, 2.53; 95%CI, 1.14-5.62). Patients with $TNF{\beta}$ G/G genotype had poor cumulative survival (p=0.005). Cox proportional hazard model indicated that $TNF{\beta}$ G/G genotype was a biomarker for poor HCC survival (hazard ratio, 1.70; 95%CI, 1.07-2.69). In conclusion, there are independent and additive effects between $TNF{\beta}$ G/G genotype and chronic HBV/HCV infection on risk for HCC. It is a biomarker for poor HCC survival. Carriage of this genotype correlates with disease severity and advanced hepatic fibrosis, which may contribute to a higher risk and poor survival of HCC. Chronic HBV/HCV infected subjects with this genotype should receive more intensive surveillance for early detection of HCC.

• Journal of Life Science
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• v.20 no.9
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• pp.1294-1298
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• 2010

White spot syndrome virus (WSSV) is one of the most virulent viral agents threatening the penaeid shrimp culture industry. This study was carried out to evaluate the susceptibility of the sand shrimp, Crangon affinis, to WSSV as an alternative experimental model. WSSV caused 100% mortality in C. affinis within 7 days after experimental infection by immersion. Based on challenge studies, it was confirmed that C. affinis could be a potential host in WSSV transmission. Also, the neutralization of WSSV was carried out using an antiserum raised against recombinant envelop protein rVP466 to evaluate the WSSV infection mechanism. A constant amount of WSSV (at $1{\times}10^4$ diluted stocks) was incubated with various amounts of antiserum and then mixed to 20 l reservoir for the immersion challenge of C. affinis for neutralization. At 5 days post challenge, the shrimp in the positive control immersed in the immersion reservoir containing WSSV stock showed 100% mortality. The shrimps challenged with the 3 different mixtures of WSSV and rVP466 antiserum (1:0.1, 1:0.5 and 1:1) showed 100%, 68.8% and 68.8% mortality at 14 days post challenge, respectively. These results indicated that the antiserum raised against rVP466 could block WSSV infection in C. affinis. Therefore, this study confirmed that C. affinis can be naturally infected by WSSV as another potential host and that C. affinis can be used as an alternative experimental animal instead of penaeid shrimps.

• Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.195-204
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• 2008

Viral diseases are major emerging problems of shrimp that have affected the production, and even complete losses for shrimp farms. In this study, we developed a sensitive TaqMan real-time PCR method to quantify white spot syndrome virus (WSSV) and hepatopancreatic parvovirus (HPV) in the shrimp and pond water in which fleshy shrimp, Fenneropenaeus chinensis, and Pacific white shrimp, Litopenaeus vannamei, are reared. WSSV and HPV in pond seawaters ranged from $1.65{\times}10^3$ to $2.43{\times}10^9$ and from 0 to $4.43{\times}10^5$ copies/L of seawater, respectively. Of 20 ponds analyzed, all pond water and shrimp were positive for WSSv. L. vannamei showed higher susceptibility to WSSV than F chinensis. HPV was detected only in the pond water for F chinensis. In shrimp tissue, however, HPV was found in both species, with 23-times higher infection rate in F chinensis than L. vannamei. The total bacterial counts in the pond water ranged from $2.23{\times}l0^3$ to $1.98{\times}l0^5\;CFU/mL$. The variations in total bacterial count for each pond appeared to correlate to the variations of the WSSV load. Statistical analysis indicated that there was no significant difference (P>0.05) between the WSSV load in pond water and shrimp, and there was no relationship between total bacterial load and viral load in the pond water. However, a significant difference (P<0.01) was found between HPV load and L. vannamei and F chinensis pond water.

• Journal of Veterinary Science
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• v.24 no.4
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• pp.51.1-51.17
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• 2023

Background: To date, various genotypes of infectious bronchitis virus (IBV) have co-circulated and in Korea, GI-15 and GI-19 lineages were prevailing. The spike protein, particularly S1 subunit, is responsible for receptor binding, contains hypervariable regions and is also responsible for the emerging of novel variants. Objective: This study aims to investigate the putative major amino acid substitutions for the variants in GI-19. Methods: The S1 sequence data of IBV isolated from 1986 to 2021 in Korea (n = 188) were analyzed. Sequence alignments were carried out using Multiple alignment using Fast Fourier Transform of Geneious prime. The phylogenetic tree was generated using MEGA-11 (ver. 11.0.10) and Bayesian analysis was performed by BEAST v1.10.4. Selective pressure was analyzed via online server Datamonkey. Highlights and visualization of putative critical amino acid were conducted by using PyMol software (version 2.3). Results: Most (93.5%) belonged to the GI-19 lineage in Korea, and the GI-19 lineage was further divided into seven subgroups: KM91-like (Clade A and B), K40/09-like, QX-like (I-IV). Positive selection was identified at nine and six residues in S1 for KM91-like and QX-like IBVs, respectively. In addition, several positive selection sites of S1-NTD were indicated to have mutations at common locations even when new clades were generated. They were all located on the lateral surface of the quaternary structure of the S1 subunits in close proximity to the receptor-binding motif (RBM), putative RBM motif and neutralizing antigenic sites in S1. Conclusions: Our results suggest RBM surrounding sites in the S1 subunit of IBV are highly susceptible to mutation by selective pressure during evolution.

• Biomolecules & Therapeutics
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• v.32 no.4
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• pp.481-491
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• 2024

Paxlovid is the first approved oral treatment for coronavirus disease 2019 and includes nirmatrelvir, a protease inhibitor targeting the main protease (M^pro) of SARS-CoV-2, as one of the key components. While some specific mutations emerged in M^pro were revealed to significantly reduce viral susceptibility to nirmatrelvir in vitro, there is no report regarding resistance to nirmatrelvir in patients and animal models for SARS-CoV-2 infection yet. We recently developed xenograft tumors derived from Calu-3 cells in immunodeficient mice and demonstrated extended replication of SARS-CoV-2 in the tumors. In this study, we investigated the effect of nirmatrelvir administration on SARS-CoV-2 replication. Treatment with nirmatrelvir after virus infection significantly reduced the replication of the parental SARS-CoV-2 and SARS-CoV-2 Omicron at 5 days post-infection (dpi). However, the virus titers were completely recovered at the time points of 15 and 30 dpi. The virus genomes in the tumors at 30 dpi were analyzed to investigate whether nirmatrelvir-resistant mutant viruses had emerged during the extended replication of SARS-CoV-2. Various mutations in several genes including ORF1ab, ORF3a, ORF7a, ORF7b, ORF8, and N occurred in the SARS-CoV-2 genome; however, no mutations were induced in the M^pro sequence by a single round of nirmatrelvir treatment, and none were observed even after two rounds of treatment. The parental SARS-CoV-2 and its sublineage isolates showed similar IC₅₀ values of nirmatrelvir in Vero E6 cells. Therefore, it is probable that inducing viral resistance to nirmatrelvir in vivo is challenging differently from in vitro passage.

• Journal of Life Science
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• v.30 no.11
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• pp.947-955
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• 2020

The foot-and-mouth disease virus (FMDV), a member of the Aphthovirus genus in the Picornaviridae family, affects wild and domesticated ruminants and pigs. During replication of the FMDV RNA (ribonucleic acid) genome, FMDV-encoding RNA polymerase 3D acts in a highly location-specific manner. This suggests that specific RNA structures recognized by 3D polymerase within non-coding regions of the FMDV genome assist with binding during replication. One such region is the cis-acting replication element (CRE), which functions as a template for RNA replication. The FMDV CRE adopts a stem-loop conformation with an extended duplex stem, supporting a novel 15-17 nucleotide loop that derives stability from base-stacking interactions, with the exact RNA nucleotide sequence of the CRE producing different RNA secondary structures. Here, we show that CRE sequences of FMDVs isolated in Korea from 2010 to 2017 exhibit A and O genotypes. Interestingly, variations in the RNA secondary structure of the Korean FMDVs are consistent with the phylogenetic relationships between these viruses and reveal the specificity of FMDV infections for particular host species. Therefore, we conclude that each genetic clade of Korean FMDV is characterized by a unique functional CRE and that the evolutionary success of new genetic lineages may be associated with the invention of a novel CRE motif. Therefore, we propose that the specific RNA structure of a CRE is an additional criterion for FMDV classification dependent on the host species. These findings will help correctly analyze CRE sequences and indicate the specificity of host species for future FMDV epidemics.

• Pediatric Infection and Vaccine
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• v.13 no.1
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• pp.63-70
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• 2006

Purpose : We hypothesized that mannose binding lectin gene(MBL2), a key molecule of innate immunity, may contirbute to the development and the outcome of respiratory syncytial virus(RSV) disease in early childhood. This study was performed to investigate the genetic basis of polymorphisms and haplotypes of MBL2 for RSV disease severity in Korean children. Methods : Cases with severe RSV diseases are 99 children with severe RSV lower respiratory tract infections, who were admitted to the Seoul National University Children's Hospital through 1993~2000. The control subjects consisted of 224 anonymous healthy Korean blood donors. The frequency of promoter variant(-221, X/Y) and structural variant(codon 54) were compared between the case patient group and the control subject group. Results : The mean age of patients was 11.8 months; 49% were <6 months, 39% were 6-24 months and 12% were >24 months. In the cohort of cases of severe RSV diseases, the genotypic frequencies of structural variant in codon 54 were 61% for AA, 34% for AB, and 5% for BB. Those of the promoter X/Y variant were 85% for YY and 15% for XY. There were no significant differences in overall distribution of both structural and promoter variants between the cases and the control subjects. We did not observe statistical difference in the haplotypic frequencies of MBL2. Conclusion : Common variants of MBL2 gene most likely do not contribute to the risk for severe RSV diseases in Korean children. Further genetic association studies should be conducted in a larger propsectively recruited cohort of children with RSV infection.