• Journal of Microbiology and Biotechnology
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• v.30 no.6
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• pp.937-945
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• 2020

N-acyl-homoserine lactone (AHL)-mediated quorum sensing (QS) plays a major role in development of biofilms, which contribute to rise in infections and biofouling in water-related industries. Interference in QS, called quorum quenching (QQ), has recieved a lot of attention in recent years. Rhodococcus spp. are known to have prominent quorum quenching activity and in previous reports it was suggested that this genus possesses multiple QQ enzymes, but only one gene, qsdA, which encodes an AHL-lactonase belonging to phosphotriesterase family, has been identified. Therefore, we conducted a whole genome sequencing and analysis of Rhodococcus sp. BH4 isolated from a wastewater treatment plant. The sequencing revealed another gene encoding a QQ enzyme (named jydB) that exhibited a high AHL degrading activity. This QQ enzyme had a 46% amino acid sequence similarity with the AHL-lactonase (AidH) of Ochrobactrum sp. T63. HPLC analysis and AHL restoration experiments by acidification revealed that the jydB gene encodes an AHL-lactonase which shares the known characteristics of the α/β hydrolase family. Purified recombinant JydB demonstrated a high hydrolytic activity against various AHLs. Kinetic analysis of JydB revealed a high catalytic efficiency (k_cat/K_M) against C4-HSL and 3-oxo-C6 HSL, ranging from 1.88 x 10⁶ to 1.45 x 10⁶ M^-1 s^-1, with distinctly low K_M values (0.16-0.24 mM). This study affirms that the AHL degrading activity and biofilm inhibition ability of Rhodococcus sp. BH4 may be due to the presence of multiple quorum quenching enzymes, including two types of AHL-lactonases, in addition to AHL-acylase and oxidoreductase, for which the genes have yet to be described.

• Clinical and Experimental Pediatrics
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• v.52 no.5
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• pp.622-626
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• 2009

Kikuchi-Fujimoto disease was initially described as a self-limiting histiocytic necrotizing lymphadenitis in Japan in 1972, and is predominantly observed in women under the age of 30 year and in Asian populations. The pathogenesis is still poorly understood but is thought to include infections, and autoimmune and neoplastic diseases. The most common clinical manifestations are fever and painless cervical lymphadenitis. Diagnosis is based on the histopathological findings, characterized by focal necrosis in the paracortical region with abundant karyorrhexis, aggregates of atypical mononuclear cells around the zone of necrosis, absence of neutrophils and plasma cells, and usually intact lymph node capsule. There is no specific therapy for the condition, and aseptic meningitis can occur as one of the complications. Here, we report the case of a patient with Kikuchi-Fujimoto disease accompanied with aseptic meningitis, which may be confused as a case of tuberculous meningitis and lymphadenitis.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.68-74
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• 2015

Based on the genomic analysis of Thermococcus pacificus P-4, we identified a putative GH1 ${\beta}$-glucosidase-encoding gene (Tpa-glu). The gene revealed a 1,464 bp encoding 487 amino acid residues, and the deduced amino acid residues exhibited 77% identity with Pyrococcus furiosus ${\beta}$-glucosidase (accession no. NP_577802). The gene was cloned and expressed in Escherichia coli system. The recombinant protein was purified by metal affinity chromatography and characterized. Tpa-Glu showed optimum activity at pH 7.5 and $75^{\circ}C$, and thermostability with a half life of 6 h at $90^{\circ}C$. Tpa-Glu exhibited hydrolyzing activity against various pNP-glycopyranosides, with kcat/Km values in the order of pNP-${\beta}$-glucopyranoside, pNP-${\beta}$-galactopyranoside, pNP-${\beta}$-mannopyranoside, and pNP-${\beta}$-xylopyranoside. In addition, the enzyme exhibited exo-hydrolyzing activity toward ${\beta}$-1,3-linked polysaccharide (laminarin) and ${\beta}$-1,3- and ${\beta}$-1,4-linked oligosaccharides. This is the first description of an enzyme from hyperthermophilic archaea that displays exo-hydrolyzing activity toward ${\beta}$-1,3-linked polysaccharides and could be applied in combination with ${\beta}$-1,3-endoglucanase for saccharification of laminarin.

• Journal of Life Science
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• v.14 no.2
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• pp.280-285
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• 2004

The ovarian hormone-deficiency induced ovariectomy rat is widely used as an aging model due to its practicality, convenience, and cost effectiveness. The surgically ovariectomized rat induces reactive oxygen species (ROS) generation like aging phenomena. Free oxygen radicals have been proposed as important causative agents of aging. The purpose of this study was to investigate the effect of chondroitin sulfate (CS) to prevent ovariectomy (OVX)-induced oxidative stress. The OVX rats were given intraperitoneally CS at doses of 100 mg/kg and 200 mg/kg daily for fifteen weeks. Malondialdehyde (MDA) levels were determined as well as the activities of superoxide dismutase (SOD), catalase (CAT), reduced-glutathione (GSH), oxidized-glutathione (GSSG), glutathione peroxidase (GPx) in the liver. The liver antioxidative enzyme activity was elevated while MDA concentration decreased in all CS treated animals. The results demonstrated that CS reduced oxidative stress in a dose dependent manner. These results suggest that CS might be a useful candidate for antioxidative reagent.

• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.383-393
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• 2019

The purpose of this study was to investigate the improvement effect of turmeric (Curcuma longa L.) on the hepatic functional enzyme and catalase activity of streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley (SD) male rats were divided into four groups (n=6), and fed experimental diets containing turmeric meal [basal diet+5% turmeric (BT), basal diet+STZ+5% turmeric (ST)], and control (basal diet, BD), BS groups (basal diet+STZ). Serum concentrations of creatinine and blood urea nitrogen (BUN) were significantly decreased (p<0.05) by 5% turmeric supplementation diet. The activities of akaline phosphatase (ALP), lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT), amylase and lipase were decreased in the BD, BT and ST group than BS group. The catalase (CAT) activity was significantly increased (p<0.05) in turmeric supplementation diet (BT, ST group) than diabetic group (BS). Furthermore, the activities of amylase and lipase in the sera of turmeric diet group were significantly decreased (p<0.05). In vivo experiments with diabetic rats showed that ingestion of turmeric supplementation diet were effective in creatinine concentration, and hepatic functional enzyme activities.

• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.119-125
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• 2006

Present study aims to study antioxidant enzyme activity due to turbidity change in various tissues of Carassius auratus. As for the changes of antioxidant enzyme activity in tissues of C. auratus pursuant to the raising period under 50, 100, and 150 NTU with turbid water levels, there was no great difference between 50 NTU and 100 NTU compared to a control (0 NTU), however, it demonstrated a relatively noticeable difference at 150 NTU high turbid water level. When considering the antioxidant capacity in tissues of C. auratus in terms of DPPH free radical scavenging activity, there was shown a high activity in gill and liver tissues, therefore, it is thought that there appears a non-enzymatic antioxidant reaction when C. auratus is reared under the condition of highly turbid water. As for the enzymatic antioxidant reaction of antioxidant enzyme activity got increased as turbid water level went higher in order of 50, 100, 150 NTU, and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione-s-transperase (GST), increased in all tissues except for an integument, up to 20th day when it was started to be reared, and they showed a gradual decrease as time passed by. However, since the activity of glutathione reductase (GR) and glutathione peroxidase (GPX) is very low in almost all tissues, it is thought that the role of those enzymes would be quite ignorable in the course of antioxidant process.

• Nutrition Research and Practice
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• v.3 no.2
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• pp.156-161
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• 2009

Hyperglycemia in the diabetic state increases oxidative stress and antioxidant therapy can be strongly correlated with decreased risks for diabetic complications. The purpose of this study is to determine antioxidant effect of garlic and aged black garlic in animal model of type 2 diabetes. The antioxidant activity of garlic and aged black garlic was measured as the activity in scavenging free radicals by the trolox equivalent antioxidant capacity (TEAC) assay. Three week-old db/db mice were fed AIN-93G diet or diet containing 5% freeze-dried garlic or aged black garlic for 7 weeks after 1 week of adaptation. Hepatic levels of lipid peroxides and activities of antioxidant enzymes were measured. TEAC values of garlic and aged black garlic were $13.3{\pm}0.5$ and $59.2{\pm}0.8{\mu}mol/g$ wet weight, respectively. Consumption of aged black garlic significantly decreased hepatic thiobarbituric acid reactive substances (TBARS) level compared with the garlic group which showed lower TBARS level than control group (p<0.05). Activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of garlic and aged black garlic group were significantly elevated compared to the control group. Catalase (CAT) activity of aged black garlic group was increased compared with the control group. These results show that aged black garlic exerts stronger antioxidant activity than garlic in vitro and in vivo, suggesting garlic and aged black garlic, to a greater extent, could be useful in preventing diabetic complications.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.6
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• pp.774-781
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• 2012

This study investigated dose-response effects of chlorogenic acid (CA) on glucose metabolism and the antioxidant system in streptozotocin (STZ)-induced diabetic mice with a high-fat diet (HFD). Male ICR mice were fed with a HFD (37% calories from fat) for 4 weeks prior to intraperitoneal injection with STZ (100 mg/kg body weight). Diabetic mice were supplemented with two doses of CA (0.02% and 0.05%, wt/wt) for 6 weeks. Both doses of CA significantly improved fasting blood glucose level, glucose tolerance and insulin tolerance without any changes in plasma insulin and C-peptide levels. Plasma leptin concentration was significantly higher in the CA-supplemented groups than in the diabetic control group. Both doses of CA significantly increased hepatic glucokinase activity and decreased glucose-6-phosphatase activity compared to the diabetic control group. The ratio of glucokinase/glucose-6-phosphatase was dose-independently higher in CA-supplemented mice than in diabetic control mice. CA supplementation dose-independently elevated superoxide dismutase and catalase activities, whereas it lowered lipid peroxide levels compared to the diabetic control mice in the liver and erythrocyte. These results suggest that low-dose CA may be used as a hypoglycemic agent in a high-fat diet and STZ-induced diabetic mice.

• Parasites, Hosts and Diseases
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• v.31 no.1
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• pp.43-48
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• 1993

Antibody test is sometimes necessary for the diagnosis of acute human metagonimiasis because eggs may not be detected in stool. The antibody test (ELISA) was evaluated for its significance by reacting human sera from clinically diagnosed metagonimiasis, fascioliasis, clonorchiasis and paragonimlasis with 4 crude extracts of Metosonimn vokognwai (metacercariael , adults of Fosciola hepatica Cronorchis sinenis and Paragonimus westermoni. By ELISA, 10 of 11 metagonimlasis sera showed the highest absorbance (abs.) to the homologous antigen. Cross reactions to M. yokogawai antigen occurred most frequently in clonorchiasis sera. The antigenic protein fractions in M. vokogawai metacercarial extract were observed by SDS-PAGElimmunoblot using patients and control sera together with experimental cat sera. Out of 14 protein bands In the extract, 11 bands were reacting. Cross reacting bands to other trematodiasis sera were frequently observed. Of the reacting bands, 66 and 22 kDa proteuls were recognized as specific for metagonimiasis.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.702-709
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• 2014

Luffa cylindrica Roem (sponge gourd) belongs to the Cucurbitaceae family and has been cultivated as an ornamental plant in Korea. Recently, its cultivation area has been increased with an increase in demand for it as an ingredient in cosmetics, herbal medicines, and health supplements. We analyzed inorganic components of sap collected from land race sponge gourds. We also measured antioxidant enzyme activities and antimicrobial activities of the plant, seed, and sap to examine functional properties of sponge gourd. The sap of the sponge gourd contained high levels of K, Ca, P, and Mg, with the most abundant mineral in the sap being K ($470mg{\cdot}L^{-1}$). The amounts of Ca and Mg were 2 and 1.7 times more than those found in cucumber (Cucumis sativus), respectively. Ascorbate peroxidase was more active than catalase and superoxide dismutase in various plant parts of sponge gourd. Antioxidant activities were much lower in stems than in other plant parts such as leaves, roots, flowers, fruits, seeds, and sap. In addition, sap showed a very low level of antimicrobial activity against two food-borne pathogens, Vibrio parahaemdyticus and Propionibacterium acne, and none against the other eight tested food-borne pathogens. Antimicrobial activities against Candida albicans and Malassezia furfur, which causes dermatitis, appeared to be higher in sap than in other parts of sponge gourd plants. Overall, the antimicrobial activity against Malassezia furfur appeared to be higher than against Candida albicans.