• Journal of Korean Neurosurgical Society
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• v.66 no.3
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• pp.316-323
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• 2023

Objective : Owing to advances in critical care treatment, the overall survival rate of preterm infants born at a gestational age (GA) <32 weeks has consistently improved. However, the incidence of severe intraventricular hemorrhage (IVH) has persisted, and there are few reports on in-hospital morbidity and mortality. Therefore, the aim of the present study was to investigate trends surrounding in-hospital morbidity and mortality of preterm infants with severe IVH over a 14-year period. Methods : This single-center retrospective study included 620 infants born at a GA <32 weeks, admitted between January 2007 and December 2020. After applying exclusion criteria, 596 patients were included in this study. Infants were grouped based on the most severe IVH grade documented on brain ultrasonography during their admission, with grades 3 and 4 defined as severe. We compared in-hospital mortality and clinical outcomes of preterm infants with severe IVH for two time periods : 2007-2013 (phase I) and 2014-2020 (phase II). Baseline characteristics of infants who died and survived during hospitalization were analyzed. Results : A total of 54 infants (9.0%) were diagnosed with severe IVH over a 14-year period; overall in-hospital mortality rate was 29.6%. Late in-hospital mortality rate (>7 days after birth) for infants with severe IVH significantly improved over time, decreasing from 39.1% in phase I to 14.3% in phase II (p=0.043). A history of hypotension treated with vasoactive medication within 1 week after birth (adjusted odds ratio, 7.39; p=0.025) was found to be an independent risk factor for mortality. When comparing major morbidities of surviving infants, those in phase II were significantly more likely to have undergone surgery for necrotizing enterocolitis (NEC) (29.2% vs. 0.0%; p=0.027). Additionally, rates of late-onset sepsis (45.8% vs. 14.3%; p=0.049) and central nervous system infection (25.0% vs. 0.0%; p=0.049) were significantly higher in phase II survivors than in phase I survivors. Conclusion : In-hospital mortality in preterm infants with severe IVH decreased over the last decade, whereas major neonatal morbidities increased, particularly surgical NEC and sepsis. This study suggests the importance of multidisciplinary specialized medical and surgical neonatal intensive care in preterm infants with severe IVH.

• Journal of Ginseng Research
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• v.47 no.3
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• pp.458-468
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• 2023

Background: As a complication of Type II Diabetes Mellitus (T2DM), the etiology, pathogenesis, and treatment of cognitive dysfunction are still undefined. Recent studies demonstrated that Ginsenoside Rg1 (Rg1) has promising neuroprotective properties, but the effect and mechanism in diabetes-associated cognitive dysfunction (DACD) deserve further investigation. Methods: After establishing the T2DM model with a high-fat diet and STZ intraperitoneal injection, Rg1 was given for 8 weeks. The behavior alterations and neuronal lesions were judged using the open field test (OFT) and Morris water maze (MWM), as well as HE and Nissl staining. The protein or mRNA changes of NOX2, p-PLC, TRPC6, CN, NFAT1, APP, BACE1, NCSTN, and Ab1-42 were investigated by immunoblot, immunofluorescence or qPCR. Commercial kits were used to evaluate the levels of IP3, DAG, and calcium ion (Ca²⁺) in brain tissues. Results: Rg1 therapy improved memory impairment and neuronal injury, decreased ROS, IP3, and DAG levels to revert Ca²⁺ overload, downregulated the expressions of p-PLC, TRPC6, CN, and NFAT1 nuclear translocation, and alleviated Aβ deposition in T2DM mice. In addition, Rg1 therapy elevated the expression of PSD95 and SYN in T2DM mice, which in turn improved synaptic dysfunction. Conclusions: Rg1 therapy may improve neuronal injury and DACD via mediating PLC-CN-NFAT1 signal pathway to reduce Aβ generation in T2DM mice.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.331-341
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• 2022

This study was conducted to identify yeast species isolated from domestic pear blossom through gene sequencing and analysis of morphological characteristics, and to confirm specific yeast species inhibitory effects toward fire blight in immature apples, pears, and crab apple blossoms. Yeast morphological characteristics were consistent with the known characteristics of Aureobasidium pullulans. Nucleotide sequencing of the D1/D2 region of large-subunit (LSU) 26S ribosomal DNA and the internal transcribed spacer (ITS) region confirmed its identity as A. pullulans (MHAU2101). Inoculation of immature fruits with A. pullulans MHAU2101 before exposure to Erwinia amylovora prevented fire blight symptoms in apples and pears. A. pullulans MHAU2101 treated crab apple blossoms had a significantly lower flower infection rate than untreated blossoms, revealing 64% of the potency of streptomycin. The A. pullulans MHAU2101 treated group also displayed lower E. amylovora density in both pistil and hypanthium compared to the untreated group, especially in the hypanthium. This study confirms that A. pullulans MHAU2101 isolated from domestic pear blossom can effectively suppress the onset of fire blight.

• The Korean Journal of Mycology
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• v.50 no.3
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• pp.217-224
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• 2022

This study aimed to isolated wild yeasts from freshwater in Korea. The strains were identified by using the D1/D2 domains of the 26S rDNA regions. Consequently, six strains were named as Apiotrichum chiropterorum (NNIBRFG36995), A. domesticum (NNIBRFG32938), A. dulcitum (NNIBRFG33144), A. laibachii (NNIBRFG36991), Saprochaete quercus (NNIBRFG33183) and Tausonia pullulans (NNIBRFG33181). These yeasts have not previously been recorded in Korea, this paper is the first report. We were investigated to the morphological and cultural characteristics of these yeasts. All the strains grew well on Yeast extract peptone dextrose (YPD), Potato dextrose (PD), and Yeast mold (YM) media and in temperature range of 15-30℃. A. domesticum (NNIBRFG32938), A. laibachii (NNIBRFG36991) and T. pullulans (NNIBRFG33181) grew even in 20% glucose containing YPD medium, so they had glucose tolerance. A. domesticum (NNIBRFG32938) and A. laibachii (NNIBRFG36991) had salt resistance as growing even in 5% NaCl containing YPD medium.

• The Korean Journal of Mycology
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• v.50 no.1
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• pp.31-40
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• 2022

We aimed to produce a potent β-glucuronidase inhibitor from wild yeast that could inactivate toxic substances in the colon. Culture supernatants and cell-free extracts of non-pathogenic wild yeasts were prepared and their β-glucuronidase inhibitory activities were measured. Cell-free extract from Candida oleophila WP5-19-1 showed the highest β-glucuronidase inhibitory activity (49.0%). The β-glucuronidase inhibitor was maximally produced (IC₅₀ value; 8.4 mg) when C. oleophila WP5-19-1 was cultured in potato dextrose medium containing 5% dextrose (initial pH; 6.0) at 30℃ for 24 hours. β-glucuronidase inhibitor of C. oleophila WP5-19-1 was partially purified by trypsin hydrolysis, ultrafiltration (3 kDa), and Sephadex G-50 filtration. The partially purified β-glucuronidase inhibitor was stable from 30℃ to 60℃ and at pH 6.0 9.0, and showed residual inhibitory activity of about 80%.

• The Korean Journal of Mycology
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• v.50 no.1
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• pp.65-73
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• 2022

This study aimed to isolate wild yeasts from seawaters and soils samples of the Haeundae and Mongdol beaches on the southern coast of Korea, and to characterize these unrecorded wild yeast strains. In total, 41 strains, representing 37 different species of wild yeast were isolated from 70 samples collected from the beaches. Among these, 14 strains were isolated from the alkalophilic medium of yeast extract-peptone-dextrose (YPD) medium (pH 9.0), and 27 strains were isolated concurrently on general YPD medium (pH 6.5). Among the 41 isolated wild yeast strains, Candida insectorum HUD 16-3(JSL-KSS-002) and Metschnikowia citriensis HUD 12-5(JSL-KSS-001) had not previously been recorded. We investigated the microbiological characteristics of these two unrecorded yeast strains and three other strains-, Cystobasidium lysinophilum JSC 52-2(JSL-GGU-019), Candida takata NMD 11-1(JSL-GGU-017) and Candida panamensis ASG 58M-2(JSL-GGU-018) from Jangseoncheon in Jellabuk-do and Jangtaesan in Deajeon city. All five previously unrecorded yeasts were oval and did not form spores. All strains grew well in YPD and yeast extract-malt extract media in a vitamin-free medium. Two strains, including C. insectorum HUD 16-3(JSL-KSS-002) grew well in a 15% NaCl-containing YPD medium. Three strains, including Cys. lysinophilum JSC52-2(JSL-GGU-019) assimilated lactose, and all strains assimilated starch.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.291-300
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• 2022

In this study, the physical properties of the medium and changes in the wood chemical composition of the sawdust were investigated during the cultivation of oak mushroom sawdust bags, and the following results were obtained. After inoculation, the weight of the medium decreased during the incubation period. It is determined that this is not due to evaporation of moisture containing the medium or decomposition of sawdust, but to decomposition of rice bran, a low molecular substance added to the medium. It was confirmed that the moisture content of the medium was steadily increased during incubation, and it was estimated that the organic substrates such as rice brane in the medium was decomposed by mycelium, and water, one of the decomposition products of organic substrates, caused an increase in the moisture content of the medium. Along with the increase in the harvest of oak mushrooms, the proportion of organic substances such as holocellulose and lignin, the main components of the wood cell wall of sawdust, steadily decreased. In particular, the degradation characteristics of the wood cell wall component of shiitake, which is a white rot fungi, were confirmed by higher lignin reduction rate than that of holocellulose. On the other hand, ash, which is an inorganic material, increased with an increase in the number of mushroom harvests. The increase in the amount of ash in the medium may have been due to the decrease in the organic matter content such as holocellulose and lignin.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.301-310
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• 2022

Lentinula edodes is a type of mushroom widely consumed in East Asia, and many of the components contained in them are used as raw materials for pharmaceuticals or as health supplements. Ergothioneine, a sulfur-containing amino acid in L. edodes, is attracting attention due to its antioxidant and anti-inflammatory effects. L. edodes generally contain an ergothioneine content of about 200 to 800 mg per kg; there are some differences in this value depending on the cultivation conditions. In this study, 24 domestic sawdust-cultivated L. edodes cultivars were cultured under the same conditions, and the morphological characteristics and ergothioneine content of the fruiting bodies were investigated. The yield and morphological characteristics of the fruiting bodies were different in each cultivar. Taehyanggo and Sanjo 713ho had the largest and thickest pileus. The pileus of L. edodes had a higher ergothioneine content than the stipe. Sanjo 715ho had the highest ergothioneine content in the pileus and the stipe at 1,225 mg/kg and 753 mg/kg, respectively. An ergothioneine content of more than 1,000 mg/kg in the pileus was observed in Bambithyang, Sansanhyang, Sulbaekhyang, Taehyanggo, Sanjo 705ho, Sanjo 709ho, Sanjo 715ho, and Sanjo 716ho. These cultivars can be used as parental strains to develop new cultivars with enhanced ergothioneine functionalities.

• The Korean Journal of Mycology
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• v.50 no.2
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• pp.93-102
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• 2022

A new cultivar of oak mushroom Lentinula edodes 'Jadam' was bred from monokaryotic strains of 'Hwadam-18' and 'GMLE36295-22'. The optimum temperature for mycelial growth of 'Jadam' on potato dextrose agar was 22-25℃. Total cultivation period of the new cultivar, from inoculation to its first harvest, was 122-124 days, shorter to that of the control cultivar 'Hwadam'. Total yield of 'Jadam' was 623.8 g per 3 kg substrate, and is higher than that of 'Hwadam' (455.2 g). In the fruiting body of the new cultivar, the stipe was shorter and thinner than those of 'Hwadam'. A farmhouse field test showed that the period of mycelial growth and browning was shorter than that of control cultivar 'L808'. The total yield for 2 flush was 543.3 g for 'Jadam'. It was similar to the 585.3 g of the control cultivar. Therefore, the new cultivar 'Jadam' could be a substitute for 'L808' in the field of farms.

• The Korean Journal of Mycology
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• v.50 no.3
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• pp.149-160
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• 2022

The goal of this study was to investigate the diversity of wild yeasts from the waters and soils of Haegeumgang in Gyungsangnam-do, and Namdaecheon and Geumsancheon in upstream of Geumgang, Korea and to characterize any previously unrecorded wild yeast strains. In total, 52 strains comprising 22 different species of wild yeasts were isolated from 35 samples obtained from Haegeumgang. Forty three and sevent nine wild yeast strains were isolated from 90 samples taken from Namdaecheon and Geumsancheon, respectively. Among the total 174 isolated wild yeast strains, 4 strains, i.e., Exobasidium rhododendri HGG10-5 (NNIBR2022633FG1), Udeniomyces pyricola NDC29-1 (NNIBR2022633FG2), Diddensiella caesifluorescens GSC2-2 (NNIBR2022633FG5) and Pichia scaptomyzae BAC2-3 (NNIBR2022633FG4) were previously unrecorded yeasts were oval or spherical in shape, only Pichia scaptomyzae BAC 2-3 formed ascospores. Three strains with the exception of Udeniomyces pyricola NDC 29-1 grew well in vitamin-free medium and Exobasidium rhododendri HGG 10-5 grew well in YPD medium containing 10% NaCl. All four novel strains assimilated fructose, lactose, raffinose, starch and xylose.