• Molecules and Cells
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• v.38 no.12
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• pp.1054-1063
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• 2015

Mitochondria play a crucial role in eukaryotic cells; the mitochondrial electron transport chain (ETC) generates adenosine triphosphate (ATP), which serves as an energy source for numerous critical cellular activities. However, the ETC also generates deleterious reactive oxygen species (ROS) as a natural byproduct of oxidative phosphorylation. ROS are considered the major cause of aging because they damage proteins, lipids, and DNA by oxidation. We analyzed the chronological life span, growth phenotype, mitochondrial membrane potential (MMP), and intracellular ATP and mitochondrial superoxide levels of 33 single ETC component-deleted strains during the chronological aging process. Among the ETC mutant strains, 14 ($sdh1{\Delta}$, $sdh2{\Delta}$, $sdh4{\Delta}$, $cor1{\Delta}$, $cyt1{\Delta}$, $qcr7{\Delta}$, $qcr8{\Delta}$, $rip1{\Delta}$, $cox6{\Delta}$, $cox7{\Delta}$, $cox9{\Delta}$, $atp4{\Delta}$, $atp7{\Delta}$, and $atp17{\Delta}$) showed a significantly shorter life span. The deleted genes encode important elements of the ETC components succinate dehydrogenase (complex II) and cytochrome c oxidase (complex IV), and some of the deletions lead to structural instability of the membrane-$F_1F_0$-ATP synthase due to mutations in the stator stalk (complex V). These short-lived strains generated higher superoxide levels and produced lower ATP levels without alteration of MMP. In summary, ETC mutations decreased the life span of yeast due to impaired mitochondrial efficiency.

• International Journal of Industrial Entomology and Biomaterials
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• v.44 no.2
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• pp.65-71
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• 2022

The wild silkmoth Antheraea yamamai Guérin-Méneville, 1861 (Lepidoptera: Saturniidae) is an important producer of silk that is superior to the silk produced by traditional domesticated silkworm. In this study, we sequenced the complete mitochondrial genome (mitogenome) of An. yamamai collected from Jeju Island, which is the southernmost island approximately 100 km offshore southward from the Korean Peninsula. Determining this sequence will be necessary for tracing the biogeographic history of the species and developing molecular markers for identifying the origin of commercial products. Comparison of the sequence divergence among two available and the current mitogenomes revealed a low but substantial number of substitutions, totaling 23 nucleotides in the whole genome. CytB and ND5 showed the highest variability with five and four variations, respectively, suggesting that these regions will be prior regions to target for subsequent biogeographic and diagnosis study. Phylogenetic reconstruction based on all available sequences of Saturniidae showed that An. yamamai is a sister to the congeneric species An. pernyi, corroborating that Antheraea is a highly supported monophyletic group. The tribe Saturniini was clearly non-monophyletic and interrupted by Attacini and Bunaeini.

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.138-145
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• 2013

This study was conducted to evaluate the microbiological contamination on commonly used hand towels in the child care centers and to investigate the toxin gene and toxin production ability of food-borne pathogens. A total of 22 commonly used hand towels including 7 for before use and 15 for during use were tested. The average number of total aerobic bacteria and fungi were 6.2 log CFU/100 $cm^2$ and 4.1 log CFU/100 $cm^2$. Coliform bacteria were detected in 4 out of 7 before used towels (57.1%) and all of during used towels (100%). These results showed that the sanitary conditions of hand towels in the child care centers should be improved promptly. Among the pathogenic bacteria, Staph. aureus and B. cereus without Salmonella spp. were detected in 5 (22.7%) and 11 (50.0%) out of 22 hand towels. All of Staphy. aureus isolated in this study did not possess any toxin genes and did not produce enterotoxin. The detection rate of hblC, hblD, and hblA toxin genes in B. cereus was 72.7, 72.7, and 54.5% respectively. The possession rate of nheA, nheB, and nheC toxin genes showed 81.8, 72.7, and 54.5% respectively. The cytK and entFM toxin genes were presented at 45.5 and 90.0% in B. cereus. The HBL was detected in 8 out of 11 B. cereus isolates (72.7%) and 5 B. cereus isolates produced NHE (45.5%). Ten out of eleven B. cereus isolates (90.9%) produced one or more enterotoxin such as HBL and NHE. From the results, using a private hand towel or paper towel is required to prevent the cross-contamination between commonly used hand towel and children's hands in the child care center.

• Food Science of Animal Resources
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• v.38 no.1
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• pp.203-208
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• 2018

The objective of this study was to investigate the pathogenicity and antimicrobial resistance of foodborne pathogens isolated from farmstead cheeses. Twenty-seven isolates, including 18 Bacillus cereus, two Escherichia coli, and seven Staphylococcus aureus, were subjected to polymerase chain reaction (PCR) to detect virulence genes and toxin genes, and the antibiotic resistances of the isolates were determined. All E. coli isolates were determined by PCR to be non-pathogenic. Among the 18 B. cereus isolates, 17 isolates (94.4%) were diarrheal type, as indicated by the presence of nheA, entFM, hbIC, cytK and bceT genes, and one isolate (5.6%) was emetic type, based on the presence of the CER gene. Among the seven S. aureus isolates, three (42.9%) had the mecA gene, which is related to methicillin-resistance. Most B. cereus isolates (94.7%) showed antibiotic resistance to oxacillin and penicillin G, and some strains also showed resistance to ampicillin (26.3%), erythromycin (5.3%), tetracycline (10.5%), and vancomycin (5.3%). These results indicate that microbial food safety measures for farmstead cheese must be implemented in Korea because antibiotic resistant foodborne pathogens, with resistance even to vancomycin, harboring virulence genes were found to be present in the final products of farmstead cheese.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.2043-2048
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• 2015

Bacillus thuringiensis microbial insecticide products have been applied worldwide. Although a few cases of B. thuringiensis foodborne illness have been reported, little is known about the toxigenic properties of B. thuringiensis isolates. The aims of this study were to estimate the pathogenic potential of B. thuringiensis selected from microbial insecticide products, based on its possession of toxin genes and production of enterotoxins. Fifty-two B. thuringiensis strains selected from four kinds of microbial insecticide products were analyzed. PCR assay for detection of toxin genes and immunoassay for detection of enterotoxins were performed. The hemolysin BL complex as a major enterotoxin was produced by 17 (32.7%), whereas the non-hemolytic enterotoxin complex was detected in 1 (1.9%) of 52 B. thuringiensis strains. However, cytK, entFM, and ces genes were not detected in any of the tested B. thuringiensis strains. The potential risk of food poisoning by B. thuringiensis along with concerns over B. thuringiensis microbial insecticide products has gained attention recently. Thus, microbial insecticide products based on B. thuringiensis should be carefully controlled.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.57-57
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• 2021

Oxygen glucose deprivation/re-oxygenation (OGD/R) induces neuronal injury via mechanisms that are believed to mimic the pathways associated with brain ischemia. Stachys sieboldii Miq. (Chinese artichoke), which has been extensively used in oriental traditional medicine to treat of ischemic stroke; however, the role of S. sieboldii Miq. (SSM) in OGD/R induced neuronal injury is not yet fully understood. The present research is aimed to investigate the protective effect and possible mechanisms of SSM extract treatment in an in vitro model of OGD/R to simulate ischemia/reperfusion Injury. Pretreatment of these cells with SSM significantly attenuated OGD/R-induced production of reactive oxygen species (ROS) by increasing GPx, SOD, and decreasing MDA. SSM decreased mitochondrial damage caused by OGD/R injury and inhibited the release of cyt-c from mitochondrion to cytoplasm in SH-SY5Y cells. Furthermore, neuronal cell apoptosis caused by OGD/R injury was inhibited by SSM, and SSM could decrease apoptosis by increasing ratio of Bcl-2/Bax and inhibiting caspase signaling pathway in SH-SY5Y cells. SSM demonstrated a neuroprotective effect on the simulated cerebral ischemia in vitro model, and this effect was the inhibition of mitochondria-mediated apoptosis pathway by scavenging of ROS generation. Therefore, SSM may be a promising neuroprotective strategy against ischemic stroke.

• Journal of Food Hygiene and Safety
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• v.38 no.4
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• pp.217-227
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• 2023

The consumption of ready-to-eat side dishes is rapidly growing in South Korea. These foods are particularly vulnerable to microbiological contamination as they are often cooked without any treatment, such as heating or stored at room temperature after cooking. Hence, in 2022, we analyzed the ready-to-eat side dishes sold in Gyeongsangnam-do, South Korea for microbiological contamination. We collected 100 samples from supermarkets in 7 cities, and then examined them for presence of food-borne pathogens and sanitary indicator bacteria. In the analysis of the food-borne pathogens, Bacillus cereus and Clostridium perfringens were isolated from 51 samples (51.0%) and 3 samples (3.0%), respectively. However, both quantitatively met the Korean Food Standards Codex. Genes of five different enterotoxins and one emetic toxin were analyzed from the 51 isolated B. cereus strains. We detected enterotoxin entFM (100.0%), nheA (94.1%), hblC (58.8%), cytK (56.9%), and bceT (41.2%) in 51 isolates, and emetic toxin gene, CER, in only one (2.0%) isolate. We did not detect C. perfringens toxin gene (cpe) that causes food poisoning in any one of the three C. perfringens isolates. In the case of sanitary indicator bacteria, Kimchi had the highest levels of total aerobic bacteria and coliforms, followed by Saengchae, Jeotgal, Jeolim, Namul, and Jorim, respectively. We counted total aerobic bacteria at two different storage temperatures (4℃ and 20℃) to determine the effect of storage temperature. When stored at 20℃, total aerobic bacteria count increased in most of the ready-to-eat side dishes, except for Jeotgal. This result conclusively shows the need for refrigerating the ready-to-eat side dishes after purchase. Further research is needed to assess the risk and safety of the ready-to-eat side dishes available in the market and determine appropriate safety management practices.

• Journal of Applied Biological Chemistry
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• v.52 no.1
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• pp.1-7
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• 2009

For the development of qualitative PCR detection method of genetically modified (CM) rice, rice species-specific gene, OsCc-1 (rice cytochrome c gene), was selected as suitable far use as an endogenous gene in rice. The primer pair OsCytC-5'/3'with 111 bp amplicon was used for PCR amplification of the rice endogenous gene, OsCc-1 and no amplified product was observed from 8 different crops as templates. Qualitative PCR method was carried out with stack traits of L528$\times$CryIAc1 GM rice developed in Korea. For the qualitative PCRs, some primer pairs were designed with a construct-specific and event-specific type based on T-DNA and junction sequences of T-DNA in GM rice. Actck-5'/3' amplifying between actin promoter and OsCK1 gene introduced in LS28 gave rise to an amplicon 306 bp; also, CrLB-5'/3' from CryIAcl and CKRB-5'/3'amplifying the junction region of T-DNA and genome sequence from LS28 as event-specific primers gave rise to an amplicon 142 bp and 91 bp, respectively. These primer pairs for the detection of event-specific targets not produced PCR amplicons on non-CM rice and various crops in contrast to event lines. Therefore, in this study we verified that event-specific primers were effective to specifically detect stack trait lines and demonstrated that this method presented could be provided with the detection-method data for risk assessment analysis of GM rice to be commercialized.

• Proceedings of the Ginseng society Conference
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• 1984.09a
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• pp.21-26
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• 1984

The balance between metabolic activation of xenobiotics and detoxification of their active metabolites may playa vital role in controlling mutagenic and carcinogenic processes. To assess the possible role of P. ginseng C.A. Meyer in detoxification of xenobiotics, we studied the effects of ginseng on several parameters of the monooxygenasd system, including benzo(a) pyrene monooxygenase(AHH) and benzo(a) pyrene epoxide hydratase(EH) as well as effects of ginseng on the conjugation system. Test animals receiving ginseng saponin-fraction induced epoxide hydratase activity to over $150\%$ (20mg/kg b.w.) of the control and increased glutathione transferase activity (GSH-T) up to $140\%$ (20mg/kg b.w.) of the control, whereas no significant changes were observed in the benzopyrene monooxygenase activity (AHH). Such a selective induction of the inactivation enzyme epoxide hydratase, combined with a marked elevation of the detoxifying enzyme glutathione transferase, without a concurrent induction of benzopyrene monooxygenase which is responsible for the formation of carcinogenic intermediates, demonstrates that ginseng has the potential to alter the metabolic course of carcinogenic polycyclic aromatic hydrocarbons, and thereby enhance detoxification. Thus, ginseng may play an important role in the prevention of tumors caused by carcinogens.

• Journal of Ginseng Research
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• v.13 no.1
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• pp.42-48
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• 1989

The binding of bay region diol-epoxides of polycyclic aromatic hydrocarbons (PAHs) to target tissue DNA is thought to be essential for the initiation of cancer by these compounds. In this study we investigated the effect of polyacetylenes such as panaxynol and panaxydol on the formation of benzo(a)pyreno (BP)-metabolite-DNA adduct in the liver of ICR mice. Treatment of mice by i.p. administration of polyacetylenes produced a marked reduction in BP metabolite binding to DNA in vitro. Following i.v. administration of (3H)BP(300, ${\mu}$Ci/21 nmoles/0.1 nt DMSO) to mice, radioactivity was detected in the DNA of the liver in vivo. The result of tentative identification of the 4 peaks between the two standard markers for high pressure liquid chromatography showed that the peaks. I, II, III, and IV were BP-phenol oxide-DNA adduct (or BP-diol-epoxide-dCyt. adduct), (-) BP$.$diolepoxide I:dGuO adduct, (+) BP-diol-epoxide I: dGuo adduct, and BP-diol-epoxide II:dGuO adduct, respectively. The minor adduct, (-) BP-diol epoxide I: dGuo was reduced to 6971 of the amount of the control, while the major adduct, (+) BP-diolepoxide I: dGuO(peak II) which was produced from (-) BP-7, 8-diol was reduced to 78% of that of the control. The amount of the minor adduct, BP-diol-epoxide II:dGuo adduct(peak IV) which formed from (+) BP-7, 8-diol was 58% of the control. These results show that the panaxydol is more related to inhibition of the formation of the minor ad- ducts than of the major adducts, which were generally produced from ($\pm$) BP-7, 8-dihydro-dials.