• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.438-446
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• 2020

Meju and nuruk (respectively soybean and malt) are traditional Korean fermentation starters that are vulnerable to contamination by harmful microorganisms such as aflatoxigenic fungi and their associated aflatoxins (AFs). In this study, Aspergillus spp. were isolated and identified from a total of 57 meju and 18 nuruk samples collected from Korean markets. Their potential aflatoxigenicity was investigated by examining the presence of three aflatoxin biosynthetic genes (aflO, aflP, and aflR) using multiplex polymerase chain reaction (mPCR) assays. Thereafter, aflatoxin production of isolates and the natural occurrence of AFs in meju and nuruk samples were analyzed by high-performance liquid chromatography (HPLC). A total of 177 Aspergillus isolates were identified and 130 isolates were obtained from meju samples. Of these, 25 isolates (19.2%) contained all three aflatoxin biosynthetic genes, and five (20%) of these isolates produced aflatoxins. Forty-seven of the Aspergillus isolates were obtained from nuruk samples, five of which (10.6%) expressed all three AF biosynthetic genes; however, none of these strains produced AFs. HPLC analysis showed that 88% (51/58) of the meju samples and 39% (7/18) of nuruk samples were not contaminated with AFs (below limit of detection). Among the isolates isolated from meju and nuruk, there were aflatoxigenic strains containing all three aflatoxin biosynthetic genes or producing aflatoxin in medium, but the frequency of aflatoxin contamination was low in the meju and nuruk samples.

• Korean Journal of Poultry Science
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• v.43 no.4
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• pp.273-279
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• 2016

Recently, it was reported that certain polymorphisms in the growth hormone secretagogue receptor gene (GHSR) are associated with the growth of chickens. However, the correlation between GHSR polymorphisms and economic traits has not been investigated in Korean native chickens (KNCs). Therefore, the objective of this study was to confirm the suitability of the GHSR gene as a candidate for genomic selection and identify a genetic marker for KNCs. A total of 220 KNCs from six breeds raised at the National Institute of Animal Science were genotyped for the c.739+726 SNP in the GHSR gene using polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP), and the sequence for a subset of 30 birds was analyzed using direct sequencing. The association between the SNP genotypes and the economic traits of the KNCs was analyzed using the statistical package for the social science (SPSS) software program. The association analysis between the c.739+726T>C SNP and economic traits revealed that the SNP was significantly associated with body weight at 150 and 270 days (BW150 and BW270, respectively) in all KNCs (p<0.01), BW150 in KNC (Gary) (p<0.05), and egg production number in KNC (White, p<0.05). In addition, the SNPs discovered using direct sequencing (513A>G, 517A>T) had a significant effect on the body weight and egg production traits (p<0.05). In conclusion, these results might be useful as a basis for studies on the improvement of KNC breeds. Furthermore, these results suggest that the SNPs (c.739+726T>C, 513A>G, and 517A>T) located in the GHSR gene could be useful molecular genetic markers for KNCs.

• Journal of Genetic Medicine
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• v.8 no.1
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• pp.1-16
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• 2011

Owing to the risk of fetal loss associated with prenatal diagnostic procedures (amniocentesis, chorionic villus sampling), noninvasive prenatal diagnosis (NIPD) is ultimate goal of prenatal diagnosis. The discovery of circulating cell-free fetal DNA (cffDNA) in maternal plasma in 1997 has opened up new probabilities for NIPD by Dr. Lo et al. The last decade has seen great development in NIPD. Fetal sex and fetal RhD status determination by cffDNA analysis is already in clinical use in certain countries. For routine use, this test is limited by the amount of cell-free maternal DNA in blood sample, the lack of universal fetal markers, and appropriate reference materials. To improve the accuracy of detection of fetal specific sequences in maternal plasma, internal positive controls to confirm to presence of fetal DNA should be analyzed. We have developed strategies for noninvasive determination of fetal gender, and fetal RhD genotyping using cffDNA in maternal plasma, using real-time quantitative polymerase chain reaction (RT-PCR) including RASSF1A epigenetic fetal DNA marker (gender-independent) as internal positive controls, which is to be first successful study of this kind in Korea. In our study, accurate detection of fetal gender through gestational age, and fetal RhD genotyping in RhD-negative pregnant women was achieved. In this assay, we show that the assay is sensitive, easy, fast, and reliable. These developments improve the reliability of the applications of circulating fetal DNA when used in clinical practice to manage sex-linked disorders (e.g., hemophilia, Duchenne muscular dystrophy), congenital adrenal hyperplasia (CAH), RhD incompatibility, and the other noninvasive pregnant diagnostic tests on the coming soon. The study was the first successful case in Korea using cffDNA in maternal plasma, which has created a new avenue for clinical applications of NIPD.

• Development and Reproduction
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• v.10 no.4
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• pp.255-261
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• 2006

Although some phytoes rogens might have beneficiary rather than adverse effects, most endocrine disrupting compounds(EDCs) are considered to be harmful to human and wildlife health through interfering the endocrine system. Previously we found that prepubertal exposure to genistein(GS), a well-known isoflavone phytoestrogen, could activate the reproductive system of immature female rats resulting precocious puberty. Interestingly, di(2-ethyl hexyl) phthalate(DEHP) exposure brought inverse result, a delayed puberty, in the same experimental regimen. In this study, we examined whether prepubertal exposure to GS or DEHP affect the gene expressions of estrogen receptors($ER\;{\alpha}$ and $ER\;{\beta}$) and LH receptor(LHR) which represent the maturational status of ovary and uterus in immature rats. GS (100 mg/kg/day) was administered daily from postnatal day 25 to the day when the first vaginal opening(VO) was observed, and the animals were sacrificed on the next day(day 32). Similarly, DEHP(l00 mg/kg/day) was administered daily from postnatal day 25 through the day when the first V.O. in control group was observed, and the animals were sacrificed on the next day(day 36). To determine the transcriptional changes in the hormone receptors, total RNAs were extracted from ovary and uterus and were applied to semi-quantitative reverse transcription polymerase chain reaction(RT-PCR). In the GS group, the transcriptional activities of $ER\;{\alpha}$, $ER\;{\beta}$ and LHR in uterus and LHR in ovary were significantly increased when compared to those of control group. In the DEHP group, the transcriptional activities of all the hormone receptors measured were significantly lowered when compared to those of control group. These alteration of the reproductive hormone receptor expressions in ovary and uterus might be represent the phenotypic aspects(secondary sexual characteristics) such as tissue weights and reproductive hormone levels during perinatal period in immature female rats.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.1
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• pp.1-13
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• 2006

Purpose: Acute gastroenteritis in children is one of the frequently encountered diseases with relatively high admission rate. The aim of this study is to determine the isolation trends of common and emerging pathogens in acute gastroenteritis in children over a 12-month period in a community hospital. Methods: The study group included the children who were hospitalized to Seoul National University Boramae Hospital from April, 2003 to March, 2004 or visited outpatient clinic from April, 2003 to July, 2003 with presenting features of acute gastroenteritis. Stool specimens were obtained within 2 days after the visit and examined for the following pathogens: rotavirus, adenovirus, Salmonella, Shigella, Vibrio, pathogenic Escherichia coli (E.coli), Campylobacter and Yersinia species. Viral study was done with commercial kits for antigen detection. Identification of the bacterial pathogens was done by culture using selective media. For pathogenic E.coli, polymerase chain reaction (PCR) was done with the target genes related to the pathogenecity of enterotoxigenic E.coli (ETEC), enteropathogenic E.coli (EPEC) and enterohemorrhagic E.coli (EHEC). Results: The 130 hospitalized children and 28 outpatients were included in this study. The majority of children (>93%) were less than 6 years. Pathogens were isolated in 47% of inpatients and 43% of outpatients, respectively. Rotavirus was the most frequently identified pathogen, accounting for 42.3% of inpatients and 29.6% of outpatients. Nontyphoidal salmonella is the most commonly isolated bacterial pathogen (3.9%) in hospitalized children. Pathogenic E.coli (EPEC, ETEC) was detected in 2.1% (2/97) of inpatients and 25% (3/12) of outpatients. EHEC, adenovirus, Campylobacter, Yersinia and Shigella species were not detected in this study. Conclusion: Rotavirus is the most common enteropathogen in children with acute gastroenteritis. Nontyphoidal salmonella and pathogenic E.coli are important bacterial pathogens. Campylobacter species may not be commonly detected organism in hospitalized children with acute diarrhea.

• Pediatric Infection and Vaccine
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• v.16 no.1
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• pp.31-39
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• 2009

Purpose : Neisseria meningitides is one of the most common causative pathogens of bacteremia and meningitis. Recently protein-conjugated vaccines have been developed and included in the routine vaccination schedule in a few countries. In Korea, carriage rates of N. meningitides among healthy adults have been reported. However, systematic data for childhood carriage rates are not available. This study was performed to evaluate the carriage rates of N. meningitides and the serotype distribution among healthy children attending day care centers. Methods : During the period of January through May 2005, nasopharyngeal swabs and culture were obtained from 904 children attending 13 different day care centers located in Seoul and Gyeonggi Province. The Vitek NHI card was used to identify N. meningitides and the crgA gene was detected via polymerase chain reaction (PCR). Serotype determination was performed by agglutination test using N. meningitides antisera to serotypes A, B, C, D, 29E, W135, X, Y, and Z. PCR for detection of the org2 and saiD gene confirmed serotypes A, B, C, W135, and Y. Results : The mean age among 904 children was 4.5 years; 6.5% (59/904) were children <2 years old, 53.8% (486/904) were 2-5 years old, and 39.7% (359/904) were >5 years old; 52.0% (468/904) were male. N. meningitides was isolated from only 7 children attending 5 different day care centers and the overall carriage rate of N. meningitides was 0.8%. The detected serotypes of N. meningitides were serotype A (n=2), C (n=2), and Y (n=3). Conclusion : The carriage rate of N. meningitides among healthy children attending day care centers was very low in Korea and the detected serotypes were A, C, and Y.

• Annals of Clinical Microbiology
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• v.21 no.4
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• pp.86-91
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• 2018

Background: The PANA RealTyper HPV kit (PANAGENE, Korea; PANA RealTyper) was developed to genotype human papillomavirus (HPV) and was based on multiplex real-time PCR amplification and melting curve analysis. In this study, we compared PANA RealTyper to the AdvanSure HPV GenoBlot assay (LG Life Sciences, Korea; AdvanSure assay) and attempted to evaluate the performance of PANA RealTyper. Methods: A total of 60 cervical specimens were collected from women undergoing routine cervical cancer screening. The AdvanSure assay and PANA RealTyper kit identified the same 20 high-risk genotypes. However, the AdvanSure assay identified 15 low-risk genotypes, while the PANA RealTyper kit identified only 2 but detected 18 low-risk genotypes. Results: Among the total 60 specimens, 54 high-risk genotypes (40 specimens) and 20 low-risk genotypes (18 specimens) were detected. The agreement rates of the assays ranged from 94.4 to 100% for high-risk genotypes. Among 9 genotypes that were positive in the PANA RealTyper kit but negative in the AdvanSure assay, 7 were confirmed as true positive (HPV genotypes 16 (n=1), 39 (n=1), 52 (n=1), 58 (n=2), 68 (n=2)). Among 4 genotypes that were negative in the PANA RealTyper kit but positive in the AdvanSure assay, 3 were confirmed as HPV genotype 59. Among the 19 low-risk genotypes positive in the AdvanSure assay, there were 2 cases of HPV 6 and 1 case of HPV 11. In comparison, only 1 positive case of HPV 6 was determined by the PANA RealTyper kit. Conclusion: The PANA RealTyper kit was comparable with the AdvanSure assay. The PANA RealTyper kit would be useful and suitable for HPV genotyping in the clinical laboratory.

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.135-142
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• 2015

The American cockroaches, Periplaneta americana L. was the most important worldwide pest species. It has been an public health problems. We were determinated life cycle and extraction of crude extracts by chemical reagents from cockraches (P. americana L.). The extracted crude solution has been antibacterial activity to gram negative bacteria (Pseudomonas aeruginosa, $6.44{\pm}1.03mm$), gram positive bacteria (Bacillus subtilis, $1.88{\pm}0.40mm$), and fungus (Candida albicans, $5.61{\pm}0.57mm$) using radial diffusion assay. We were analysed of up-regulation of Glutathione-S-transferases (GSTs) stimulation, indicating that antioxidantial protein from various classes are simultaneously expressed in a single insect upon infection or injury. The gene from Periplaneta americana L. were cloned, analysed sequence, and measured protein expression by Real Time PCR (Polymerase Chain Reaction).

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.7
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• pp.922-929
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• 2019

Objective: Mutations in low-density lipoprotein receptor (LDLR), which encodes a critical protein for cholesterol homeostasis and lipid metabolism in mammals, are involved in cardiometabolic diseases, such as familial hypercholesterolemia in pigs. Whereas microRNAs (miRNAs) can control LDLR regulation, their involvement in circulating cholesterol and lipid levels with respect to cardiometabolic diseases in pigs is unclear. We aimed to identify and analyze LDLR as a potential target gene of SSC-miR-20a. Methods: Bioinformatic analysis predicted that porcine LDLR is a target of SSC-miR-20a. Wild-type and mutant LDLR 3'-untranslated region (UTR) fragments were generated by polymerase chain reaction (PCR) and cloned into the pGL3-Control vector to construct pGL3 Control LDLR wild-3'-UTR and pGL3 Control LDLR mutant-3'-UTR recombinant plasmids, respectively. An miR-20a expression plasmid was constructed by inserting the porcine premiR-20a-coding sequence between the HindIII and BamHI sites in pMR-mCherry, and constructs were confirmed by sequencing. HEK293T cells were co-transfected with the miR-20a expression or pMR-mCherry control plasmids and constructs harboring the corresponding 3'-UTR, and relative luciferase activity was determined. The relative expression levels of miR-20a and LDLR mRNA and their correlation in terms of expression levels in porcine liver tissue were analyzed using reverse-transcription quantitative PCR. Results: Gel electrophoresis and sequencing showed that target gene fragments were successfully cloned, and the three recombinant vectors were successfully constructed. Compared to pMR-mCherry, the miR-20a expression vector significantly inhibited wild-type LDLR3'-UTR-driven (p<0.01), but not mutant LDLR-3'-UTR-driven (p>0.05), luciferase reporter activity. Further, miR-20a and LDLR were expressed at relatively high levels in porcine liver tissues. Pearson correlation analysis revealed that porcine liver miR-20a and LDLR levels were significantly negatively correlated (r = -0.656, p<0.05). Conclusion: LDLR is a potential target of miR-20a, which might directly bind the LDLR 3'-UTR to post-transcriptionally inhibit expression. These results have implications in understanding the pathogenesis and progression of porcine cardiovascular diseases.

• Journal of Life Science
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• v.31 no.8
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• pp.710-718
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• 2021

Placenta-derived mesenchymal stem cells (PD-MSCs) are promising candidates for cell-based therapy in regenerative medicine. The migration and homing potential of PD-MSCs to injured sites is a critical property of MSC engraftment. MicroRNAs (miRNAs) have recently been shown to regulate the critical functions of MSCs, such as proliferation, survival, and migration. The objective of the present study was to identify the miRNA and target genes involved in PD-MSCs homing in a bile duct ligation (BDL) rat model. We selected candidate miRNAs targeting genes for PD-MSCs homing based on microarray analysis. PD-MSC engraftment in BDL-injured rat liver was identified by immunofluorescence assay and human-specific Alu gene expression by quantitative real-time polymerase chain reaction (qRT-PCR) one week after transplantation. Compared with migrated naïve PD-MSCs under hypoxic and normoxic conditions (Hyp/Nor), the transplanted group with PD-MSCs (Tx) showed distinct differences in miRNA expressions in BDL-injured rat liver. We also validated the miRNAs and their target genes for PD-MSCs homing. The expressions of integrin α4 (ITGA4) and integrin α5 (ITGA5) target genes for miR-199a-5p and miR-148a-3p were significantly upregulated in the Tx group (p<0.05). In addition, integrin β1 (ITGB1) and integrin β8 (ITGB8) were upregulated by suppressing miR-183-5p and miR-145-5p, respectively. These results demonstrated that PD-MSCs regulate miRNA expression related to the integrin family for their homing effects on the BDL-injured rat liver. The findings further suggest that miRNA-mediated regulation of the integrin family contributes to the therapeutic efficacy of PD-MSCs in the rat hepatic fibrosis model by BDL.