• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.388-394
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• 2017

Although several analytical methods for measuring total antioxidant capacity (TAC) have been applied to biological samples, there were often dissimilar results due to the different principles of methods applied. Thus, this study aimed to validate four conventional analytical methods for measuring plasma TAC, including the ABTS assay, DPPH assay, FRAP assay, and ORAC assay, by comparing with urinary 8-isoprostane concentration. In addition, TAC results were compared with antioxidant enzyme activities including superoxide dismutase (SOD) and glutathione peroxidase in erythrocyte, and catalase in plasma. Plasma TAC measure by ABTS assay was strongly correlated with the result by FRAP assay. Plasma TAC by FRAP and ORAC assays were negatively correlated with erythrocyte SOD activity. The agreement among the four TAC assay methods and 8-isoprostane was determined using 95% prediction limits of linear regression, expressed as the mean of 8-isoprostane ${\pm}95%$ prediction limits. The ABTS method better agreed with 8-isoprostane than the other methods, demonstrating narrow prediction of limits. Furthermore, only plasma TAC determined by the ABTS assay was inversely correlated with urinary 8-isoprostane (r = -0.35, p < 0.05). In summary, the ABTS assay would be an appropriate method to measure overall plasma antioxidant capacity and predict the body's antioxidant status.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.70-79
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• 2014

In an attempt to develop a variety of expression vector systems for Corynebacterium glutamicum, six types of promoters, including $P_{tac}$, $P_{sod}$, $P_{sod}$ with a conserved Shine-Dalgarno (SD) sequence from C. glutamicum, $P_{ilvC}$, $P_{ilvC}$ with a conserved SD-1 ($P_{ilvC-M1}$), and $P_{ilvC}$ with a conserved SD-2 ($P_{ilvC-M2}$), were cloned into a modified shuttle vector, pCXM48. According to analysis of promoter strength by quantitative reverse transcription PCR, $P_{sod}$ and $P_{sod-M}$ were superior to tac and ilvC promoters in terms of transcription activity in C. glutamicum. All of the promoters have promoter activities in Escherichia coli, and $P_{sod-M}$ displayed the highest level of transcriptional activity. The protein expression in constructed vectors was evaluated by measuring the fluorescence of green fluorescent protein (GFP) and SDS-PAGE. C. glutamicum harboring plasmids showed GFP fluorescence with an order of activity of $P_{ilvC}$ > $P_{ilvC-M1}$ > $P_{sod}$ > $P_{ilvC-M2}$ > $P_{sod-M}$, whereas all plasmids except pCSP30 with $P_{sod}$ displayed fluorescence activities in E. coli. Of them, the strongest level of GFP was observed in E. coli with $P_{sod-M}$, and this seems to be due to the introduction of the conserved SD sequence in the translational initiation region. These results demonstrate that the expression vectors work well in both C. glutamicum and E. coli for the expression of target proteins. In addition, the vector systems harboring various promoters with different strengths, conserved SD sequences, and multiple cloning sites will provide a comfortable method for cloning and gene expression, and consequently contribute to the metabolic engineering of C. glutamicum.

• Journal of Community Nutrition
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• v.7 no.4
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• pp.215-219
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• 2005

Oxygen radical absorbance capacity(ORAC) is known to be a sensitive and simple method to determine total antioxidant capacity(TAC) in biological samples. While TAC has received great attention with its relation to pathogenesis in the progression of several diseases, little is known about association of ORAC with metabolic risk factors. The aim of this study is to evaluate the relationship between ORAC and serum lipid profiles, fasting glucose and anthropometric measures. One hundred seventeen volunteers participated in the study. Perchloric acid treated serum was used to determine $ORAC_{pca}$. Mean$ORAC_{pca}$ of subjects whose serum total cholesterol(TC) concentrations were $\geq$ 200 mg/dl was significantly(P < 0.05) higher than that of subjects whose TC concentrations were < 200mg/dl. There were significantly positive correlations between $ORAC_{pca}$ and serum concentrations of TC(P < 0.05) and low density lipoprotein (LDL) cholesterol(P < 0.01). The positive relation between cholesterol concentrations and $ORAC_{pca}$ in serum may suggest an elevated TAC against oxidative stress associated with the cardiovascular risk factors. (J Community Nutrition 7(4): $215\∼219$, 2005)

• Clinical and Experimental Reproductive Medicine
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• v.45 no.2
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• pp.88-93
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• 2018

Objective: The aim of this study was to measure reactive oxygen species (ROS) production and total antioxidant capacity (TAC) in the seminal fluid of the male partners in couples undergoing intrauterine insemination and to evaluate correlations between these values and their semen parameters. Methods: The study was conducted at Vamsam Fertility Center, Coimbatore, India and enrolled 110 male patients from whom semen samples were collected. ROS production was measured by a thiobarbituric acid reactive species assay, and TAC was measured by a 2,2-diphenyl-2-picrylhydrazyl free radical assay. The differences in the TAC and malondialdehyde (MDA) levels between the subfertile and fertile groups were analysed. Correlations between sperm parameters and TAC and MDA levels were statistically analysed, and cutoff values with respect to the controls were determined. All hypothesis tests used were two-tailed, with statistical significance assessed at the level of p< 0.05. Results: A total of 87 subfertile and 23 fertile men were included in the study. The mean MDA level was significantly higher in the subfertile subjects than in the fertile subjects, and the mean antioxidant level was significantly lower in the subfertile subjects than in the fertile subjects. Seminal MDA levels were negatively associated with sperm concentration, motility, and morphology, whereas the opposite was seen with TAC levels. Conclusion: Measurements of seminal TAC and ROS are valuable for predicting semen quality, and hence predicting the outcomes of fertility treatment.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.288-296
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• 1995

To investigate high-level expression of Serratia marcescens metalloprotease (SMP) in Escherichia coli and S. marcescens, we constructed various recombinant plasmids: pSP2, containing SMP gene and lac promoter; pKSP2, containing SMP gene and tac promoter; pTSP2, containing SMP gene, trc99a promoter, and lacI$^{q}$. The recombinant E. coli (pKSP2) strain expressed SMP to a high-level, about 36% of total cellular proteins but accumulated inactive SMP precursors intracellularly, which indicated that E. coli does not have activation and secretion system for SMP. To overproduce active SMP, we transformed S. marcescens with the recombinant plasmids by a modified CaCl$_{2}$ method. The recombinant S. marcescens ATCC27117 (pSP2) containing lac promoter for SMP transcription produced 530 U/ml of active SMP on LB broth, which is about 5.1 times of the SMP yield, 105 U/ml of a control strain, S. marcescens ATCC27117 (pUC19). However, S. marcescens ATCC27117 (pKSP2) containing tac promoter for SMP transcription did not grow healthy and hardly produced SMP. To overcome a harmful effect of the strong tac promoter, we constructed a regulatory plasmid pTSP2 containing a strong trc99a promoter and its repressor gene lacI$^{q}$. When S. marcescens ATCC27117 (pTSP2) was induced with 1.0 mM IPTG after 9 hr cultivation, 2,200 U/ml of SMP was obtained in LB broth, which is about 21 times of that of a control strain.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.476-480
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• 2005

Immunosuppressive therapy in pediatric renal transplant recipients is changing consequence of the increasing number of available immunosuppressive agents. The optimal use of immunosuppressive agents requires a thorough understanding of the pharmacokinetic characteristics, but the information on the pharmacokinetic characteristics of these drugs in pediatric transplant recipients is still limited. In general, patients younger than 5 years old show higher clearance rates, therefore the need for higher dosages in younger patients seems evident. By the therapeutic drug monitoring, trough($C_{min}$) and peak level($C_{max}$) are measured and the area under the blood concentration-time curve(AUC), which is taken as being representative of total systemic exposure can be calculated. Cyclosporine A (CSA) has poor bioavailability, which contributes to high inter- and intra-patient pharmacokinetic variability. CSA concentration measured 2 hours after administration($C_2$) has better correlation with the AUC than $C_{min}$ and is an alternative technique that predicts the AUC. Tacrolimus(Tac) has a great deal of inter-individual variability like CSA but intra-individual variability in systemic exposure is considered to be low. Both CSA and Tac are metabolized by a cytochrome P-450 enzyme isoform(CYP3A4). We should consider changing the dosages when CSA or Tac is used in combination with the medicines that inhibit or induce the CYP3A4. In case of steroid-free immunosuppressive therapy, the blood concentration of Tac should be frequently checked and dosage adjustment may be needed.

• Clinical and Experimental Reproductive Medicine
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• v.47 no.1
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• pp.54-60
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• 2020

Objective: Oxidative stress plays a key role in the pathogenesis of male infertility. But, the adverse effects of oxidative biomarkers on sperm quality remain unclear. This study aimed to investigate the levels of nitric oxide (NO), 8-hydroxydesoxyguanosine (8-OHdG), and total antioxidant capacity (TAC) oxidative biomarkers in seminal plasma and their relationship with sperm parameters. Methods: A total of 77 volunteers participated in the study, including fertile (n = 40) and infertile men (n = 37). NO, 8-OHdG, and TAC levels were measured using the ferric reducing ability of plasma, Griess reagent method and an enzyme-linked immunosorbent assay kit, respectively. Results: The mean values of sperm parameters in the infertile group were significantly lower than those in the fertile group (p< 0.001). The mean 8-OHdG in the seminal plasma of infertile men was significantly higher (p= 0.013) than those of controls, while the mean TAC was significantly lower (p= 0.046). There was no significant difference in NO level between the two groups. The elevated seminal 8-OHdG levels were negatively correlated with semen volume, total sperm counts and morphology (p< 0.001, p= 0.001 and p= 0.052, respectively). NO levels were negatively correlated with semen volume, total sperm counts and morphology (p= 0.014, p= 0.020 and p= 0.060, respectively). Positive correlations between TAC and both sperm count and morphology (p= 0.043 and p= 0.025, respectively) were also found. Conclusion: These results suggested that increased levels of NO and 8-OHdG in seminal plasma could have a negative effect on sperm function by inducing damage to the sperm DNA hence their fertility potentials. Therefore, these biomarkers can be useful in the diagnosis and treatment of male infertility.

• Korean Journal of Community Nutrition
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• v.13 no.1
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• pp.91-99
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• 2008

The present study was conducted to examine metabolic risk factors and total antioxidant capacity (TAC) of Korean females living in Seoul and to investigate the relationship between the metabolic risk factors and serum TAC. A total of 353 females aged between 20 and 64 participated in the study. Obesity indicators, blood pressure, serum lipid profile and fasting blood glucose were measured as metabolic risk factors. Ferric reducing antioxidant power (FRAP) assay was employed to determine serum TAC of subjects. Obesity indicators such as body mass index, waist circumference and waist-hip ratio were significantly higher in the participants aged $\geq$ 50 y (older group) than in the participants aged 20-49 y (younger group) (p < 0.001). Blood pressure, serum total cholesterol (TC), triglyceride (TG) and fasting blood glucose were also significantly higher in the older group than in the younger group (p < 0.001), demonstrating significant positive correlations between age and MS risk factors. The association between FRAP and MS risk factors were also investigated. FRAP values showed significant positive correlations with age (p = 0.001), serum TG (p = 0.002) and TC (p = 0.03). A tendency of positive association between FRAP and waist circumference was observed without any significant difference (p = 0.06). Increased serum FRAP with central obesity and serum lipids may be interpreted as results of activation of antioxidant defense system against oxidative stress induced by metabolic syndrome (MS) constituent factors. However, to verify the function of FRAP as a potential biomarker of susceptibility to MS various contributors to the plasma antioxidant capacity and their biological relevance related to MS should be elucidated further.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.54-59
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• 2020

The inconsistent methods of harvest, identification, and preparation of brown algae samples make it difficult to compare the results of certain measurements across different studies, such as total phenolic contents (TPC), total flavonoid contents (TFC), and total antioxidant capacities (TAC). Therefore, this study aims to systematically measure and compare TPC, TFC, and TAC in 10 types of standardized brown algae extracts provided by the Bio-Resource Information System of Korea. Among the ten brown algae extracts, Ishige foliacea exhibited the highest levels of TPC and TAC, followed by Sargassum nigrifolium. TAC was measured by the following four assays: ABTS, DPPH, superoxide radical scavenging activities, and ferric reducing antioxidant power. TAC was found to be positively correlated with TPC (p<0.05) but not TFC, indicating that Ishige foliacea and Sargassum nigrifolium have potential use as marine antioxidative food material.

• 대한생식의학회:학술대회논문집
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• 2000.06a
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• pp.37-42
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• 2000

Objective: To determine whether particular semen characteristics in various clinical diagnoses of infertility are associated with high oxidative stress and whether any group of infertile men is more likely to have high seminal oxidative stress. Reactive oxygen species (ROS) play an important role in sperm physiological functions, but elevated levels of ROS or oxidative stress are related to male infertility. Design: Measurement of sperm concentration, motility, morphology, seminal ROS, and total antioxidant capacity (TAC) in patients seeking infertility treatment and controls. Setting: Male infertility clinic of a tertiary care center. Patient(s): One hundred sixty-seven infertile patients and 19 controls. Intervention(s): None. Main Outcome Measure(s): Semen characteristics, seminal ROS, and TAC in samples from patients with various clinical diagnoses and controls. Result(s): Fifteen patients (9.0%) were Endtz positive and 152(91.0%) Endtz negative. Sperm concentration, motility, and morphology were significantly reduced in all groups compared with the controls (P = .02), except in varicocele associated With infection group. Mean (${\pm}$SD) ROS levels in patient groups ranged from 2.2 ${\pm}$ 0.13 to 3.2 ${\pm}$ 0.35, signilicantly higher than controls (1.3 ${\pm}$ 0.3; P<.005). Patient groups had a significantly lower mean (${\pm}$SD) TAC from 1014.75 ${\pm}$ 79.22 to 1173.05 ${\pm}$ 58.07 than controls (1653 ${\pm}$ 115.28, P<.001), except ill the vaseclony reversal group (1532.02 ${\pm}$ 74.24). Sperm concentration was negatively correlated with ROS both overall and within all groups (P${\leq}$.007), with the exception of idiopathic infertility. Conclusion(s): Irrespective of the clinical diagnosis and semen characteristics, the presence of seminal oxidative stress in infertile men suggests its role in the pathophysiology of infertility. Medical or surgical treatments for infertility in these men should include strategies to reduce oxidative stress.