• Journal of Radiation Protection and Research
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• v.46 no.3
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• pp.98-105
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• 2021

Background: In recent events of the coronavirus disease 2019 (COVID-19) pandemic, computed tomography (CT) scans are being globally used as a complement to the reverse-transcription polymerase chain reaction (RT-PCR) tests. It will be important to be aware of major organ dose levels, which are more relevant quantity to derive potential long-term adverse effect, for Korean pediatric and adult patients undergoing CT for COVID-19. Materials and Methods: We calculated organ dose conversion coefficients for Korean pediatric and adult CT patients directly from Korean pediatric and adult computational phantoms combined with Monte Carlo radiation transport techniques. We then estimated major organ doses delivered to the Korean child and adult patients undergoing CT for COVID-19 combining the dose conversion coefficients and the international survey data. We also compared our Korean dose conversion coefficients with those from Caucasian reference pediatric and adult phantoms. Results and Discussion: Based on the dose conversion coefficients we established in this study and the international survey data of COVID-19-related CT scans, we found that Korean 7-year-old child and adult males may receive about 4-32 mGy and 3-21 mGy of lung dose, respectively. We learned that the lung dose conversion coefficient for the Korean child phantom was up to 1.5-fold greater than that for the Korean adult phantom. We also found no substantial difference in dose conversion coefficients between Korean and Caucasian phantoms. Conclusion: We estimated radiation dose delivered to the Korean child and adult phantoms undergoing COVID-19-related CT examinations. The dose conversion coefficients derived for different CT scan types can be also used universally for other dosimetry studies concerning Korean CT scans. We also confirmed that the Caucasian-based CT organ dose calculation tools may be used for the Korean population with reasonable accuracy.

• Journal of Genetic Medicine
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• v.15 no.2
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• pp.79-86
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• 2018

Purpose: This study aimed to evaluate the clinical usefulness of non-invasive prenatal testing (NIPT) as an alternative testing of invasive diagnostic testing in pregnancies with ultrasound abnormalities. Materials and Methods: This was a retrospective study of pregnant women with abnormal ultrasound findings before 24 weeks of gestation between April 2016 and March 2017. Abnormal ultrasound findings included isolated increased nuchal translucency, structural anomalies, and soft markers. The NIPT or diagnostic test was conducted and NIPT detected trisomy 21 (T21), T18, T13 and sex chromosomal abnormalities. We analyzed the false positive and residual risks of NIPT based on the ultrasound findings. Results: During the study period, 824 pregnant women had abnormal ultrasound findings. Among the study population, 139 patients (16.9%) underwent NIPT. When NIPT was solely performed in the patients with abnormal ultrasound findings, overall false positive risk was 2.2% and this study found residual risks of NIPT. However, the discordant results of NIPT differed according to the type of abnormal ultrasound findings. Discordant results were significant in the group with structural anomalies with 4.4% false positive rate. However, no discordant results were found in the group with single soft markers. Conclusion: This study found different efficacy of NIPT according to the ultrasound findings. The results emphasize the importance of individualized counseling for prenatal screening or diagnostic test based on the type of abnormal ultrasound.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.429-437
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• 2020

This study aimed to investigate the change in physicochemical properties and lactic acid bacterial communities during kimchi fermentation at different temperatures (8, 15, and 25 ℃) using two molecular genetics approaches, multiplex polymerase chain reaction and 16S rRNA gene sequencing. The pH during fermentation at 8, 15, and 25 ℃ decreased from 6.17 on the initial fermentation day to 3.92, 3.79, and 3.48 after 54, 30, and 24 days of fermentation, respectively, while the acidity increased from 0.24% to 1.12, 1.35, and 1.54%, respectively. In particular, the levels of lactic acid increased from 3.74 g/L on the initial day (day 0) to 14.43, 20.60, and 27.69 g/L during the fermentation after 24, 18, and 12 days at 8, 15, and 25 ℃, respectively, after that the lactic acid concentrations decreased slowly. The predominance of lactic acid bacteria (LAB) in the fermented kimchi was dependent on fermentation stage and temperature: Lactobacillus sakei appeared during the initial stage and Leuconsotoc mesenteroides was observed during the optimum-ripening stage at 8, 15, and 25 ℃. Lac. sakei and Lactobacillus plantarum grew rapidly in kimchi produced at 8, 15, and 25 ℃. In addition, Weissella koreensis first appeared at days 12, 9, and 6 at 8, 15, and 25 ℃ of fermentation, respectively. This result suggests that LAB population dynamics are rather sensitive to environmental conditions, such as pH, acidity, salinity, temperature, and chemical factors including free sugar and organic acids.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.652-661
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• 2021

Xanthomonas citri pv. glycines (Xcg) is a major pathogen of soybean (Glycine max) in South Korea, despite the availability of soybean varieties with some resistance. We conducted a nationwide survey of the incidence and severity of bacterial pustule caused by Xcg. The percentage of infected fields was 7% to 17% between 2015 and 2017. We characterized the diversity of a nationwide collection of 106 Xcg isolates based on avrBs3 banding patterns. The isolates fell into 11 groups, each represented by a type strain; only two of these were similar to isolates collected from 1999 to 2002. The diversity of Xcg strains increased and the dominant strains changed between 1999 and 2017, with three new type strains comprising 44% of the isolates examined in 2012 to 2017. Pathogenicity tests did not show evidence for a shift in the races or aggressiveness of Xcg strains. Korean soybean cultivars, including the widely-grown Daewon cultivar, were susceptible to the 11 new type strains. The cultivar CNS, which carries the rxp resistance gene, was susceptible to most type strains, including two representing 83% of the Korean Xcg strains. In contrast, Williams 82, which also carries rxp, showed resistance to at least five type strains. Collectively, these results suggest that Williams 82 has resistance loci in addition to rxp. The widespread distribution of Xcg, the high virulence of the current endemic strains, and the low resistance of most Korean soybean cultivars collectively favor widespread disease in Korea in years that are favorable to pustule development.

• Genomics & Informatics
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• v.20 no.1
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• pp.12.1-12.7
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• 2022

The two complete mitochondrial genomes (mitogenomes) of Paedocypris progenetica, the smallest fish in the world which belonged to the Cyprinidae family, were sequenced and assembled. The circular DNA molecules of mitogenomes P1-P. progenetica and S3-P. progenetica were 16,827 and 16,616 bp in length, respectively, and encoded 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and one control region. The gene arrangements of P. progenetica were identical to those of other Paedocypris species. BLAST and phylogenetic analyses revealed variations in the mitogenome sequences of two Paedocypris species from Perak and Selangor. The circular DNA molecule of P. progenetica yield a standard vertebrate gene arrangement and an overall nucleotide composition of A 33.0%, T 27.2%, C 23.5%, and G 15.5%. The overall AT content of this species was consistent with that of other species in other genera. The negative GC-skew and positive AT-skew of the control region in P. progenetica indicated rich genetic variability and AT nucleotide bias, respectively. The results of this study provide genomic variation information and enhance the understanding of the mitogenome of P. progenetica. They could later deliver highly valuable new insight into data for phylogenetic analysis and population genetics.

• Journal of Veterinary Science
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• v.21 no.6
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• pp.87.1-87.11
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• 2020

Background: A new, extended long-acting tilmicosin (TLAe) preparation was tested against intramammary ceftiofur (CEF) using a non-inferiority trial model during dry-cow therapy (DCT) in a farm with high bovine population density and deficient hygiene application. Objectives: To evaluate the possibility that TLAe administered parenterally can achieve non-inferiority status compared to CEF administered intramammary for DCT. Methods: Cows were randomly assigned to TLAe (20 mg/kg subcutaneous; n = 53) or CEF (CEF-HCl, 125 mg/quarter; n = 38 cows) treatment groups. California mastitis testing, colony-forming unit assessment (CFU/mL), and number of cases positive for Staphylococcus aureus were quantified before DCT and 7 d after calving. A complete cure was defined as no bacteria isolated; partial cure when CFU/mL ranged from 150 to 700, and cure-failure when CFU/mL was above 700. Results: TLAe and CEF had overall cure rates of 57% and 53% (p > 0.05) and S. aureus cure rates of 77.7% and 25%, respectively (p < 0.05). The pathogens detected at DCT and 7 days after calving were S. aureus (62.71% and 35.55%), Staphylococcus spp. (22.03% and 35.55%), Streptococcus uberis (10.16% and 13.33%), and Escherichia coli (5.08% and 15.55%). Non-inferiority and binary logistic regression analyses revealed a lack of difference in overall efficacies of TLAe and CEF. Apart from S. aureus, S. uberis was the predominant pathogen found in both groups. Conclusions: This study is the first successful report of parenteral DCT showing comparable efficacy as CEF, the gold-standard. The extended long-term pharmacokinetic activity of TLAe explains these results.

• Journal of Audiology & Otology
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• v.23 no.4
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• pp.175-180
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• 2019

Diagnosis of pre-lingual hearing loss (HL) is difficult owing to the high number of genes responsible. The most frequent cause of HL is DFNB1 due to mutations in the GJB2 gene. It represents up to 40% of HL cases in some populations. In Iran, it has previously been shown that DFNB1 accounts for 16-18% of cases but varies among different ethnic groups. Here, we reviewed results from our three previous publications and data from other published mutation reports to provide a comprehensive collection of data for GJB2 mutations and HL in northern Iran. In total, 903 unrelated families from six different provinces, viz., Gilan, Mazandaran, Golestan, Ghazvin, Semnan, and Tehran, were included and analyzed for the type and prevalence of GJB2 mutations. A total of 23 different genetic variants were detected from which 18 GJB2 mutations were identified. GJB2 mutations were 20.7% in the studied northern provinces, which was significantly higher than that reported in southern populations of Iran. Moreover, a gradient in the frequency of GJB2 mutations from north to south Iran was observed. c.35delG was the most common mutation, accounting for 58.4% of the cases studied. This study suggests that c.35delG mutation in GJB2 is the most important cause of HL in northern Iran.

• Korean Journal of Audiology
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• v.23 no.4
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• pp.175-180
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• 2019

Diagnosis of pre-lingual hearing loss (HL) is difficult owing to the high number of genes responsible. The most frequent cause of HL is DFNB1 due to mutations in the GJB2 gene. It represents up to 40% of HL cases in some populations. In Iran, it has previously been shown that DFNB1 accounts for 16-18% of cases but varies among different ethnic groups. Here, we reviewed results from our three previous publications and data from other published mutation reports to provide a comprehensive collection of data for GJB2 mutations and HL in northern Iran. In total, 903 unrelated families from six different provinces, viz., Gilan, Mazandaran, Golestan, Ghazvin, Semnan, and Tehran, were included and analyzed for the type and prevalence of GJB2 mutations. A total of 23 different genetic variants were detected from which 18 GJB2 mutations were identified. GJB2 mutations were 20.7% in the studied northern provinces, which was significantly higher than that reported in southern populations of Iran. Moreover, a gradient in the frequency of GJB2 mutations from north to south Iran was observed. c.35delG was the most common mutation, accounting for 58.4% of the cases studied. This study suggests that c.35delG mutation in GJB2 is the most important cause of HL in northern Iran.

• Journal of the Korean Child Neurology Society
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• v.25 no.3
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• pp.204-207
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• 2017

Hyperornithinemia-hyperammonemia-homocitrullinuria syndrome (HHH syndrome) is a neurometabolic disorder with highly variable clinical severity ranging from mild learning disability to severe encephalopathy. Diagnosis of HHH syndrome can easily be delayed or misdiagnosed due to insidious symptoms and incomplete biochemical findings, in that case, genetic testing should be considered to confirm the diagnosis. HHH syndrome is caused by biallelic mutations of SLC25A15, which is involved in the urea cycle and the ornithine transport into mitochondria. Here we report a boy with spastic paraplegia and asymptomatic younger sister who have compound heterozygous mutations of c.535C>T (p.R179^*) and c.116C>A (p.T39K) in the SLC25A15 gene. We identified that p.T39K mutation is a novel pathogenic mutation causing HHH syndrome and that p.R179^*, which is prevalent in Japanese and Middle Eastern heritage, is also found in the Korean population.

• Nutrition Research and Practice
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• v.17 no.5
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• pp.984-996
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• 2023

BACKGROUND/OBJECTIVES: Prior studies, mostly conducted in Western countries, have suggested that the low cost of energy-dense foods is associated with an increased risk of obesity. This study aimed to investigate the association between food costs and obesity risk among Koreans who may have different food cost and dietary patterns than those of Western populations. SUBJECTS/METHODS: We used baseline data from a cohort of 45,193 men and 83,172 women aged 40-79 years (in 2006-2013). Dietary intake information was collected using a validated food frequency questionnaire. Prudent and Western dietary patterns extracted via principal component analysis. Food cost was calculated based on Korean government data and market prices. Logistic regression analyses were performed to investigate the association of daily total, prudent, and Western food cost per calorie with obesity. RESULTS: Men in the highest total food cost quintile had 15% higher odds of obesity, after adjusting for demographic characteristics and lifestyle factors (adjusted odds ratio, 1.15; 95% confidence interval, 1.08-1.22; P-trend < 0.001); however, this association was not clear in women (P-trend = 0.765). While both men and women showed positive associations between prudent food cost and obesity (P-trends < 0.001), the association between Western food cost and obesity was only significant in men (P-trend < 0.001). CONCLUSIONS: In countries in which consumption of Western foods is associated with higher food costs, higher food costs are associated with an increased risk of obesity; however, this association differs between men and women.