• Mycobiology
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• 제36권4호
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• pp.249-254
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• 2008

Minimal growth inhibitory concentrations (MICs) of chitosan acetate (M.W. 60 kDa) on heterotrophic bacteria (strains MK1, S, and R) isolated from the soft-rotten tissues of Neungee mushroom (Sarcodon aspratus) were measured. The slimy substance produced by the MK1 strain was responsible for the diseased mushroom’s appearance. The S and R strains were members of the Burkholderia cepacia complex. These strains showed different levels of susceptibility toward chitosan acetate. The MIC of chitosan acetate against the MK1 and S strains was 0.06%. The MIC against the R strain was greater than 0.10%. Survival fractions of the MK1 and S strains at the MIC were $3\;{\times}\;10^{-4}$ and $1.4\;{\times}\;10^{-3}$ after 24 h, and $2\;{\times}\;10^{-4}$ and $7\;{\times}\;10^{-4}$ after 48 h, respectively. Survival fractions of the R strain after 24 and 48 hr at 0.1% chitosan acetate were $1\;{\times}\;10^{-2}$ and $6.9\;{\times}\;10^{-3}$, respectively. Compared to the MK1 and S strains, the low susceptibility of the R stain towards chitosan acetate could be due to the ability of the R strain to utilize chitosan as a carbon source. Thirty-eight percent of Neungee pieces treated in a 0.06% chitosan acetate solution for $2{\sim}3$ second did not show any bacterial growth at 4 days, whereas bacterial growth around untreated mushroom pieces occurred within 2 days. These data suggest that chitosan acetate is highly effective in controlling growth of indigenous microorganisms on Neungee. The scanning electron micrographs of the MK1 strain treated with chitosan revealed a higher degree of disintegrated and distorted cellular structures.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1452-1459
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• 2007

The Dps protein, which is overexpressed in harsh environments, is known to playa critical role in the protection of DNA against oxidative stresses. In this study, the roles of Fur in the expression of the dps gene in Salmonella and the protection mechanisms against oxidative stress in Salmonella cells preexposed to iron-stress were investigated. Two putative Fur boxes were predicted within the promoter region of the S. typhimurium dps gene. The profile of dps expression performed by the LacZ reporter assay revealed growth-phase dependency regardless of iron-status under the culture conditions. The fur mutant, $_X4659$, evidenced a reduced level of ${\beta}$-galactosidase as compared to the wild-type strain. The results observed after the measurement of the Dps protein in various Salmonella regulatory mutants were consistent with the results acquired in the reporter assay. This evidence suggested that Fur performs a function as a subsidiary regulator in the expression of dps. The survival ability of Salmonella strains after exposure to oxidative stress demonstrated that the Dps protein performs a pivotal function in the survival of stationary-phase S. typhimurium against oxidative stress. Salmonella cells grown in iron-restricted condition required Dps for full protection against oxidative stress. The CK24 (${\Delta}dps$) cells grown in iron-replete condition survived at a rate similar to that observed in the wild-type strain, thereby suggesting the induction of an unknown protection mechanism(s) other than Dps in this condition.

• Journal of Microbiology and Biotechnology
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• 제22권4호
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• pp.571-573
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• 2012

Glyceraldehyde-3-phosphate (G-3-P), the substrate of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), is a key intermediate in several metabolic pathways. Recently, we reported that G-3-P directly inhibits caspase-3 activity in a reversible noncompetitive mode, suggesting the intracellular G-3-P level as a cell fate decision factor. It has been known that apoptotic stimuli induce the generation of NO, and NO S-nitrosylates GAPDH at the catalytic cysteine residue, which confers GAPDH the ability to bind to Siah-1, an E3 ubiquitin ligase. The GAPDH-Siah-1 complex is translocated into the nucleus and subsequently triggers the apoptotic process. Here, we clearly showed that intracellular G-3-P protects GAPDH from S-nitrosylation at above a certain level, and consequently maintains the cell survival. In case G-3-P drops below a certain level as a result of exposure to specific stimuli, G-3-P cannot inhibit S-nitrosylation of GAPDH anymore, and consequently GAPDH translocates with Siah-1 into the nucleus. Based on these results, we suggest that G-3-P functions as a molecule switch between cell survival and apoptosis by regulating S-nitrosylation of GAPDH.

• 노동경제논집
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• 제38권4호
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• pp.57-81
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• 2015

본 연구는 한국노동패널 자료를 이용하여 미혼자들이 초혼까지 걸리는 시간에 어떤 요인이 중요하게 영향을 미치는지에 대해 분석함으로써, 최근 우리나라의 만혼 현상을 설명한다. 분석 결과, 교육수준과 관련하여, 여자 대졸자는 고졸 이하에 비해 결혼하지 않을 확률 대비 결혼할 확률(Odds)이 0.91배, 약 8.5% 낮아지고, 여자 석 박사 졸업자는 여자 대졸자에 비해 결혼하지 않을 확률 대비 결혼할 확률이 0.40배(59.6%) 낮아지는 것으로 나타났다. 경제력과 관련하여, 남자 취업자의 경우 미취업자에 비해 결혼하지 않을 확률 대비 결혼할 확률이 1.65배 높아지며, 직업이 상시직이면 상시직이 아닌 경우에 비해 결혼하지 않을 확률 대비 결혼할 확률이 1.60배 높아진다. 또한, 만 14세 때의 가정 형편이 평균 이하인 경우 평균 이상인 경우에 비해 결혼할 확률이 0.65배 낮아진다. 이러한 점을 종합해볼 때, 최근 우리나라의 만혼 현상은 여성의 교육수준 향상뿐만 아니라 경제력을 갖춘 남성 청년층의 감소에 상당 부분 그 원인이 있는 것으로 판단된다.

• Molecules and Cells
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• 제42권12호
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• pp.869-883
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• 2019

Interleukin (IL)-15 is an essential immune-modulator with high potential for use in cancer treatment. Natural IL-15 has a low biological potency because of its short half-life and difficulties in mass-production. IL-15Rα, a member of the IL-15 receptor complex, is famous for its high affinity to IL-15 and its ability to lengthen the half-life of IL-15. We have double-transfected IL-15 and its truncated receptor IL-15Rα into CT26 colon cancer cells to target them for intracellular assembly. The secreted IL-15:IL-15Rα complexes were confirmed in ELISA and Co-IP experiments. IL-15:IL-15Rα secreting clones showed a higher anti-tumor effect than IL-15 secreting clones. Furthermore, we also evaluated the vaccine and therapeutic efficacy of the whole cancer-cell vaccine using mitomycin C (MMC)-treated IL-15:IL-15Rα secreting CT26 clones. Three sets of experiments were evaluated; (1) therapeutics, (2) vaccination, and (3) long-term protection. Wild-type CT26-bearing mice treated with a single dose of MMC-inactivated secreted IL-15:IL-15Rα clones prolonged survival compared to the control group. Survival of MMC-inactivated IL-15:IL-15Rα clone-vaccinated mice (without any further adjuvant) exceeded up to 100%. This protection effect even lasted for at least three months after the immunization. Secreted IL-15:IL-15Rα clones challenging trigger anti-tumor response via CD4⁺ T, CD8⁺ T, and natural killer (NK) cell-dependent cytotoxicity. Our result suggested that cell-based vaccine secreting IL-15:IL-15Rα, may offer the new tools for immunotherapy to treat cancer.

• 한국수정란이식학회지
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• 제4권1호
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• pp.1-13
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• 1989

This paper reviews the most important steps that have generated consistent progress in principles and developmental progress of embryo cryopreservation, and also study on freezing procedure and its application by conventional method and current improved method for freezing procedure and its appilcation of embryo cryopreservation in farm animals. Four were of particular interest: 1.The transport of water across the ccli membrane (zona pellucida) during freezing and thawing accordinglyplays a role in determing whether the celi survives. This movement of water is controlied mainly by extracellular phase changes and by the nature and concentration of any cryoprotective agent present. Therates of cooling, freezing and warming, and the intervals over which they are applied are further decisi've factors in determining whether a cryopreservation procedure allows survival after thawing. 2.The first successful deep freezing experiments with sheep morula and blastocysts during the seventies were based on the early procedures used for mouse embryos.Current research during the eighties is developed with the aim of simplifying and improving current procedures such as one-step dilution and rapid or ultra-rapid cooling by using the model of laboratory animals. 3.The conventional method for the embryo cryopreservation is described. An alternative to this method which may result in high survival and also in reducing of the freezing and thawing time is done by combing a permeable cryoprotectant such as glycerol, DMSO or propanediol and a non-permeable compound such as sucrose, trehalose, raffinose or lactose. 4.Finally a different approach to the preservation of embryos, named vitrification, is introduced. This procedure depends upon the ability of concentrated solutions of cryoprotective agents such as glycerol and propanediol to supercool to very low temperature (-196$^{\circ}C$) during rapid cooling before solidifying without formation of ice. However, more complete data are necessary for successful vitrification of blastocysts.

• Clinical and Experimental Reproductive Medicine
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• 제45권1호
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• pp.10-16
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• 2018

Objective: Placental oxidative stress is known to be a factor that contributes to pregnancy failure. The aim of this study was to determine whether selenium could induce antioxidant gene expression and regulate invasive activity and mitochondrial activity in trophoblasts, which are a major cell type of the placenta. Methods: To understand the effects of selenium on trophoblast cells exposed to hypoxia, the viability and invasive activity of trophoblasts were analyzed. The expression of antioxidant enzymes was assessed by reverse-transcription polymerase chain reaction. In addition, the effects of selenium treatment on mitochondrial activity were evaluated in terms of adenosine triphosphate production, mitochondrial membrane potential, and reactive oxygen species levels. Results: Selenium showed positive effects on the viability and migration activity of trophoblast cells when exposed to hypoxia. Interestingly, the increased heme oxygenase 1 expression under hypoxic conditions was decreased by selenium treatment, whereas superoxide dismutase expression was increased in trophoblast cells by selenium treatment for 72 hours, regardless of hypoxia. Selenium-treated trophoblast cells showed increased mitochondrial membrane potential and decreased reactive oxygen species levels under hypoxic conditions for 72 hours. Conclusion: These results will be used as basic data for understanding the mechanism of how trophoblast cells respond to oxidative stress and how selenium promotes the upregulation of related genes and improves the survival rate and invasive ability of trophoblasts through regulating mitochondrial activity. These results suggest that selenium may be used in reproductive medicine for purposes including infertility treatment.

• 한방안이비인후피부과학회지
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• 제33권1호
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• pp.1-11
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• 2020

Objectives : The purpose of this study was to investigate the anti-inflammatory and anti-oxidative effects of Osung-tang(OST) extract. Methods : MTT assay was performed to confirm the survival rate of RAW 264.7 cells treated with OST extract(50-400㎍/㎖) and the production of NO from LPS-induced RAW 264.7 cells was confirmed. The mRNA expression of iNOS, COX-2, and NF-κB were measured by real-time PCR. The protein expression of iNOS, COX-2 and p-IκB were measured by western blot and the anti-oxidant activity of OST extract(50-400㎍/㎖) was investigated by measuring DPPH scavenging activity. Results : OST extract showed a cell survival rate of 90% or more at 50-400㎍/㎖. The NO production was inhibited in a dose-dependent manner in RAW 264.7 cells treated with LPS on OST treated group. mRNA expression levels of iNOS, COX-2 and NF-κB decreased in a concentration-dependent manner after treatment with OST(50-400㎍/㎖). Protein expression levels of iNOS, COX-2 and p-IκB decreased in a concentration-dependent manner after treatment with OST(50-400㎍/㎖). It was found that OST has a high free-radical scavenging ability. Conclusions : These results suggest that OST extract can be used as a treatment for various skin diseases by demonstrating its anti-inflammatory and anti-oxidant effects.

• International Journal of Industrial Entomology and Biomaterials
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• 제12권1호
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• pp.29-34
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• 2006

A breeding programme was initiated during 2001 utilizing two polyvoltine silkworm breeds viz. $BL_{69}$, an evolved breed tolerant to high temperature and MAR, comparatively resistant to Bombyx mori nuclear polyhedrosis virus (BmNPV) with the objective to develop robust polyvoltine breeds and hybrids. The breed $NP_1$ was developed by exposing the fifth instar larvae to high temperature $(36{\pm}1^{\circ}C)$, high Relative Humidity ($85{\pm}5%$ R.H.) and inoculating third instar larvae with BmNPV inoculum. At $F_{12}$, the breed was tested for hybrid forming ability utilizing six bivoltine silkworm breeds viz. $CSR_2,\;CSR_4,\;CSR_{17},\;CSR_{18},\;CSR_{19}\;and\;NB_4D_2$. The hybrid $'NP_1{\times}CSR_{17}'$ exhibited its superiority by recording 97.2% survival, 1.892 g cocoon weight, 0.406 g cocoon shell weight, 21.5% cocoon shell ratio, 16.6% raw silk percentage and 890 m filament length whereas the control $(PM{\times}CSR_2)$ has recorded 90.2% survival, 1.599 g cocoon weight, 0.304 g cocoon shell weight, 18.9% cocoon shell ratio, 13.1 % raw silk percentage and 768 m filament length. Commercial exploitation of the new $polyvoltine{\times}bivoltine$ hybrid in sericulture industry has been discussed.

• 한국축산식품학회지
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• 제41권2호
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• pp.274-287
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• 2021

The purpose of this study is to examine the physiological characteristics and anti-diabetic effects of Pediococcus pentosaceus KI62. The α-amylase and α-glucosidase inhibitory activity of P. pentosaceus KI62 was 94.86±3.30% and 98.59±0.52%, respectively. In MRS broth containing 3% maltodextrin inoculated by P. pentosaceus KI62, the amounts of short chain fatty acids (SCFA) were propionic acid 18.05±1.85 mg/kg, acetic acid 1.12±0.07 g/100 mL, and butyric acid 2.19±0.061 g/kg, and those of medium chain fatty acids (MCFA) were C8 0.262±0.031 mg/kg, C10 0.279±0.021 mg/kg, and C12 0.203±0.009 mg/kg. Compared to sixteen antibiotics, P. pentosaceus KI62 had the highest sensitivity to penicillin-G and rifampicin, as well as the highest resistance to vancomycin and ampicillin. The strain also showed higher leucine arylamidase and valine arylamidase activities than other enzyme activities, but it did not produce β-glucuronidase which is carcinogenic enzymes. The survival rate of P. pentosaceus KI62 in 0.3% bile was 91.67%. Moreover, the strain showed a 98.63% survival rate in pH 2.0. P. pentosaceus KI62 exhibits resistance to Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus at rates of 29.41%, 38.10%, 51.72%, and 50.47%, respectively. P. pentosaceus (23.31%) showed a similar adhesion ability to L. rhamnosus GG, the positive control (24.49%). These results show that P. pentosaceus KI62 has possibility as a probiotic with anti-diabetic effects.