• The Journal of Korean Society of Virology
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• v.28 no.1
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• pp.71-78
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• 1998

Vaccinia virus is the prototype orthopoxvirus that has been used as a vaccine strain for small pox. This virus has been used to express a variety of cellular and viral genes in mammalian cells at high levels. Interleukin-4 (IL-4) has been found to stimulate the proliferation of T cells and enhance the cytolytic activity of cytotoxic T lymphocytes. To test the immunotherapeutic potential of IL-4 delivered in vivo by poxvirus, a recombinant vaccinia virus expressing the murine IL-4 gene (RVVmIL-4) was constructed. A high level of IL-4 production was confirmed by infecting HeLa cells and measuring IL-4 in cell culture supernatant by ELISA. As a tumor model, two cell lines were used; the murine T leukemic line P388 and the murine breast cancer line TS/A. CDF1 mice were intraperitoneally inoculated with $1\;{\times}\;10^5$ cells of P388. Mice were injected at the same site with $5\;{\times}\;10^5\;PFU$ of recombinant vaccinia virus; first, 3 days after the injection of tumor cells and thereafter once every week for 3 weeks. Intraperitoneal injections of RVVmIL-4 significantly prolonged the survival time of mice inoculated with tumor cells. All mice injected with RVVmIL-4 remained alive for 30 days after the postinoculation of tumor cells, while 100% and 70% of the animals injected with saline or wild type vaccinia virus died, respectively. In another tumor model using TS/A, tumor was established by subcutaneously inoculating $2{\times}10^5$ tumor cells to BALB/c mice. After tumor formation was confirmed on day 4 in all mice, $5\;{\times}\;10^6\;PFU$ of RVVmIL-4 was inoculated subcutaneously three times, once every week for 3 weeks. The TS/A tumor was eradicated in two of the nine mice. Seven of the nine mice treated with RVVmIL-4 developed a tumor, but tumor growth was significantly delayed compared to those treated with saline or wild type vaccinia virus. These results indicate that recombinant vaccinia viruses may be used as a convenient tool for delivering immunomodulator genes to a variety of tumors.

• Pediatric Infection and Vaccine
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• v.20 no.3
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• pp.123-130
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• 2013

Purpose: Subacute sclerosing panencephalitis (SSPE) is a neurodegerative disease due to persistent measles virus infection. We investigated the role of programmed death-1 (PD-1) molecule which is related with chronic viral infection in developing SSPE in mouse. Methods: We adopt the $PD-1^{-/-}$, $PD-1^{-/+}$, and wild type BALB/c 3 week old mice to make an animal model of SSPE by injecting measles virus (SSPE strain) intraventricularly. Three months after infusion of virus, the mice were sacrificed and examined if the typical pathologic lesions had been progressed. The sera were collected from each group of mice and the serum level of IL-21 was measured with ELISA kit. Results: The necrotic lesions on white matter and gliosis were found in focal areas in wild type BALB/c. The extent of lesion was smaller in heterotype BALB/c. Scanty lesions were found in $PD-1^{-/-}$ mice. The sera level of IL-21 was not elevated in all three groups. Conclusion: Our data suggest that the PD-1 molecule may play a role in persistent viral infection.

• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.257-264
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• 2019

Mastoparan V1 was used as adjuvant of formalin-inactivated Salmonella Gallinarum whole cells vaccine against fowl typhoid in a chicken model. The 75 brown nick chickens were equally divided into 5 groups, and all chickens of each group were immunized at 6 weeks of age (0 WPPI; weeks prime post immunization), and at 9 weeks of age (3 WPPI) (except group B). Group A chickens were intramuscularly (IM) inoculated with 500 uL of sterile phosphate-buffered saline (PBS), and group B chickens were subcutaneously immunized with 0.2 ml containing 5×10⁷ viable vaccine strain/bird. The chickens in groups C~E were IM inoculated with approximately 3×10⁹ cells/0.5 mL of formalin-inactivated the S. Gallinarum whole cells, approximately 3×10⁹ cells/0.5 mL of formalin-inactivated the S. Gallinarum whole cells with mastoparan V1 as adjuvant, and 0.5 mL of PBS, respectively. S. Gallinarum outer membrane proteins-specific serum IgG titers were considerably higher in groups B~D than in groups A and E. However, the levels of IFN-γ in groups B and D only than in groups A and E were significantly higher. Following oral challenge with virulent wild-type S. Gallinarum, no chicken in groups A (no challenge group) and B was dead, and only 30% of chickens in group D was dead. However, 70% of chickens in group C and all chickens in group E were dead after oral challenge. The results of this study demonstrated that IM immunization with approximately 3×10⁹ of the formalin-inactivated S. Gallinarum whole cells containing mastoparan V1 induced robust antibody and cell-mediated immune responses in chickens. The whole cells also conferred protection against infection with wild-type S. Gallinarum.

• KSBB Journal
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• v.21 no.4
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• pp.286-291
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• 2006

Various ${\beta}$-ionone resistant mutants were isolated from the wild-type red yeast Xanthophyllomyces dendrorhous KCTC 7704. Although the growth of X. dendrorhous KCTC 7704 was strongly inhibited at 0.025 mM ${\beta}$-ionone, one of the ${\beta}$-ionone resistant mutants isolated at 0.1 mM ${\beta}$-ionone by NTG mutagenesis showed rather 70% of relative survival at 0.15 mM ${\beta}$-ionone. Fermentation kinetics study with the mutant was carried out at $20^{\circ}C$ for 4 days in 300-mL baffled flasks. The mutant yielded up to 2.3-fold higher carotenoids content(viz. $1.2{\mu}g$ of total carotenoids per mg of dry cells) compared with the wild-type strain. The production of metabolites such as organic acids could be neglected. Studies on the kinetics with various carbon substrates revealed both an increase in final dry cell mass and a higher total carotenoids content in cell mass with glucose when compared to fructose or sucrose. As a further part of study, the effect of pH on the fermentation kinetics was investigated in glucose-limited chemostat at a dilution rate of $0.04h^{-1}$. When compared to steady-state kinetic parameters obtained at pH 4.0, a significant reduction in cell concentration at pH 3.0 and a lower carotenoids content at pH 5.2 were evident.

• Journal of Microbiology
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• v.43 no.4
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• pp.337-344
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• 2005

Although pneumococcus is one of the most frequently encountered opportunistic pathogen in the world, the mechanisms responsible for its infectiveness have not yet been fully understood. In this paper, we have attempted to characterize the effects of pneumococcal transformation on the pathogenesis of the organism. We constructed three transformation-deficient pneumococcal strains, which were designated as Nos. 1d, 2d, and 22d. The construction of these altered strains was achieved via the insertion of the inactivated gene, comE, to strains 1, 2 and 22. We then conducted a comparison between the virulence of the transformation-deficient strains and that of the wild-type strains, via an evaluation of the ability of each strain to adhere to endothelial cells, and also assessed psaA mRNA expression, and the survival of hosts after bacterial challenge. Compared to what was observed with the wild-type strains, our results indicated that the ability of all of the transformation-deficient strains to adhere to the ECV304 cells had been significantly reduced (p < 0.05), the expression of psaA mRNA was reduced significantly (p < 0.05) in strains 2d and 22d, and the median survival time of mice infected with strains Id and 2d was increased significantly after intraperitoneal bacterial challenge (p < 0.05). The results of our study also clearly indicated that transformation exerts significant effects on the virulence characteristics of S. pneumoniae, although the degree to which this effect is noted appears to depend primarily on the genetic background of the bacteria.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.200-207
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• 2018

At high salt concentration, glycine betaine is transported into Bacillus subtilis and growing rate of the cell is not suppressed. Also according to recent studies, cell growth is maintained normal growth rate at low temperature. Low temperature results in a stress response of Bacillus subtilis that is characterized by strong repression of major metabolic activities such as translation machinery and membrane transport. In this regards, genes showing cold sensitive phenotype are cold-induced DEAD box RNA helicases (ydbR, yqfR) and fatty acid desaturases (bkdR, des). Therefore to understand the effect of glycine betaine on cold growth of Bacillus subtilis, we investigated the effect of glycine betaine on growth rate of these deletion mutants showing cold sensitive phenotype. Glycine betaine strongly stimulated growth of wild type Bacillus subtilis JH642 and deletion mutants of ydbR and yqfR at $20^{\circ}C$ (190~686 min $T_d$ difference). On the other hands, glycine betaine does not show growth promoting effects on deletion mutants of bkdR, and des at cold conditions. Same cold protectant growth results were shown with the precursor choline instead of glycine betaine. We investigated the effects of detergents on the cell membrane in bkdR and des deficient strains associated with cell membrane. It was identified that bkdR deficient strain shows retarded growth with detergent such as Triton X-100 or N-lauryl sarcosine compared with wild type cell. Thus, it is possible that deletion mutation of bkdR modifies membrane structure and effects on transport of glycine betaine.

• The Korean Journal of Mycology
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• v.49 no.3
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• pp.405-412
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• 2021

Wolfiporia cocos is an important medicinal fungus that has been used in regions of Northeast Asia including Korea, Japan, and China. W. cocos is classified in Korea into two types (red bokryeong and white bokryeong) based on the internal colors (yellow orange-pale pink and white) of the sclerotium. Generally, the W. cocos type cultivated on farms produces white sclerotium. In this study, we endeavored to select strains that form sclerotium in sawdust medium using 2-way cross-breeding among two cultivated strains and three wild strains. Monospores were isolated from the fruiting bodies of cultivated and wild strains on potato dextrose agar. Thirty-nine strains of 338 hybrid strains isolated formed sclerotia with white or yellow colors upon culture for 3 months in Pinus densiflora sawdust medium. Selection for sclerotium forming strains using sawdust culture follows a very simple and easy procedure that is presented for the first time in this paper. We plan to test selected strains in the field to aid in developing new varieties for the future.

• Journal of Mushroom
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• v.5 no.1
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• pp.7-12
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• 2007

All intra-specific hybrids among ASI $2172{\times}2104$, $2172{\times}2307$, $2186{\times}2172$ and $2186{\times}2307$ in P. salmoneostramineus produced pink fruiting bodies as like wild parental types. However, three hybrids of them between ASI 2186 and 2104 were white fruiting bodies. A new commercial strain "Noeul" of Pink Oyster mushroom was developed by intra-specific hyphal anastomosis. It was improved with hybridization between monokaryotic strain derived from ASI 2172 and ASI 2104. The optimum temperature of mycelial growth and fruiting body development were $25{\sim}30^{\circ}C$ and $19{\sim}24^{\circ}C$, respectively. The pileus was bright reddish pink. Commercial strain "Noeul" was as prolific as the more commonly cultivated Pleurotus ostreatus in the conversion of substrate mass to mushrooms using bottle cultivation. Mushroom cultivator can save money for mushroom growing on summer in Korea. Mushrooms should be picked when moderately young, and handled carefully so as to not bruise the brilliantly colored gills. This pink color makes marketing an interesting challenge depending upon the market niche.

• Journal of Life Science
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• v.19 no.4
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• pp.429-435
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• 2009

Oxidative stress is a consequence of an imbalance of the defense system against cellular damage generated by reactive oxygen species (ROSs) such as superoxide anions (menadione; MD). Most organisms have evolved a variety of defense systems to protect cells from adverse conditions. In order to evaluate stress tolerance against oxidative stress generating MD, comparative analyses of antioxidant capacity, or free radical scavenger ability, were performed between S. cerevisiae KNU5377 (KNU5377) and three wild-type S. cerevisiae strains. In a medium containing 0.4 mM MD, the KNU5377 strain showed higher cell viability and antioxidant ability, and contained higher levels of trehalose, superoxide dismutase, thioredoxin system, glucose-6-phosphate dehydrogenase, and some heat shock proteins. The KNU5377 strain also produced a lower level of oxidative stress biomarker than the other three yeast strains. These results indicate that S. cerevisiae KNU5377 has a higher level of tolerance to oxidative stress due to the increased expression of cell rescue proteins and molecules, thus alleviating cellular damage more efficiently than other S. cerevisiae strains.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.4
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• pp.247-253
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• 2014

In the silage quality, the process of fermentation and use of micro-organism as starter cultures are crucial. The present study investigated the effect of homo and heterofermentative lactic acid bacteria as a starter culture strain on the silage quality and its aerobic stability using meta-analysis. Total 19 studies were used in the analysis. According to the strains of lactic acid bacteria used, experimental groups were assigned to heterofermentative (HEL), mixture of hetero and homofermentative (HHO), homofermentative (HOL) and various homofermentative (HOM). In each experimental group, standardized result of the treatment (with inoculant) was compared with the control (without inoculant) using risk ratio calculation method. The effect of experimental group was also compared. Different starter culture strains did not influence on silage pH and propionic acid production. However, lactic acid and acetic acid production were significantly (p<0.05) influenced by the start culture strains. HOM showed the greatest lactic acid production and HEL was the lowest. In contrast, HEL showed the greatest in acetic acid production and HOM and HOL were the lowest. In terms of ammonia nitrogen, HHO produced more (p<0.05) than the rest of the treatment. In crude protein and water soluble carbohydrate contents, there were no significant effects among treatments. Different strain of lactic acid bacteria significantly influenced on the effect of aerobic stability (p<0.05). Use of heterofermentative showed greater aerobic stability and the use of homofermentative lactic acid bacteria.