• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.56.2-56.2
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• 2015

Nonthermal Atmospheric Pressure Plasmas and their Applications to Plasma Bioscience and Medicines have been introduced for next generation human healthcare's quantum developments. Various kinds of nonthermal atmospheric pressure plasmas have been introduced and their electron temperature and plasma densities along with reactive oxygen and nitrogen species have been diagnosed and analyzed for biological cell interactions, especially, used in Plasma Bioscience Research Center (PBRC), Korea. Herein, we have also introduced the plasma-initiated ultraviolet photolysis, which might be a generation mechanism for the reactive oxygen and nitrogen species (RONS) intracellular and extracellular regions inside the liquid when the plasma has been bombarded onto the water. Finally we have investigated the interactions of these RONS with the various cancer cells resulting in apoptotic cell death.

• Proceedings of the Korean Nutrition Society Conference
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• 1996.06b
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• pp.42-42
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• 1996

• YAKHAK HOEJI
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• v.38 no.2
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• pp.123-130
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• 1994

Physicochemical properties and hydrolysis kinetics of new some oral cephalosporins were examined in buttered solution and human plasma or rat liver homogenate. The test cephalosporins were 7-[(Z)-2-(2-aminothiazole-4-yl)-2- methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazinyl] thiocarbonylthhiomethyl-3-cephem-4-carboxylic acid (CEN1), 7-[(Z)-2-(2-aminoth iazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyrimidyl)piperazinyl]th iocarbonylthiomethyl-3-cephem-4-carboxylic acid (CEN2), pivaloyloxymethyl-7-[ (Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazi nyl]thiocarbonylthiomethy1-3-cephem-4-carboxylate (CEN1P), and pivaloyloxymethyl-7-[(Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[ 4-(2-pyrimidyl)piperazinyl]thiocarbonyl-thiomethyl-3-cephem-4-carboxylate (CEN2P). The partition coefficient(Ko/w) of CEN1P, CEN2P were higher than those of CEN1, CEN2. The calculated pKa values of CEN1, CEN2, CEN1P, and CEN2P were 7.09, 7.75, 4.92, and 5.39, respectively. The hydrolysis of CEN1P and CEN2P were not depend on the composition of pH of the test medium except weak alkaline buffered solution (pH 8.00). CEN1 and CEN2 were very stable in pH 6.80 and 8.00 buffer solutions. CEN1P and CEN2P were rapidly deesterified to CEN1 and CEN2 in human plasma and in rat liver homogenate. Half-lives$(t_{1/2})$ of CEN1 and CEN2 were 3.49 and 4.93 hr in human plasma, 1.47 and 1.26 hr in rat liver homogenate, respectively.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3284-3288
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• 2013

This paper describes first development and validation of pentafluorophenylprophyl ligand-based liquid chromatography coupled to tandem mass spectrometry (PFPLC-MS/MS) method to determine metformin, a highly polar compound, in human plasma. Metformin and Phenformin (internal standard) were extracted from human plasma 50 ${\mu}L$ with a single-step protein precipitation. The chromatographic separation was performed using a linear gradient elution of mobile phase involving 5.0 mM ammonium formate solution with 0.1% formic acid (A) and acetonitrile (B) over 3.0 min of run time on a Phenomenex Luna PFP column. The detection was performed using a triple-quadrupole tandem mass spectrometer (Waters Quattro micro) with electrospray ionization in the mode of positive ionization and multiple-reaction monitoring (MRM). The developed method was validated with 5.0 ng/mL of lower limit of quantification (LLOQ). The calibration curve was linear over 5-3000 ng/mL of the concentration range ($R^2$ > 0.99). The specificity, selectivity, carry-over effect, precision, accuracy and stability of the method met the acceptance criteria. The method developed in this study had had rapidness, simplicity and ruggedness. The reliable method was successfully applied to high throughput analysis of real samples for a practical purpose of a pharmacokinetic study.

• Nutritional Sciences
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• v.9 no.1
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• pp.48-54
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• 2006

Methods have been developed to evaluate the total antioxidant capacity of foods and plasma but limitations are associated with their ability to determine precisely the contribution of lipophilic antioxidants in a lipid milieu as well as interactions among them Thus, we modified the Oxygen Radical Absorbance Capacity (ORAC) assay to determine the peroxyradical scavenging ability of both hydrophilic and lipophilic compartments in plasma The hydrophilic ORAC assay was performed in a phosphate buffer system utilizing 2,2'-azobis (2-amidinopropane) dihydrochloride as a peroxyradical generator and fluorescein as the target The lipophilic ORAC assay was carried out in a dimethylsulfoxide :butyronitrile (DMSO/BN, 9:1 v/v) system using 2,2'-azobis (2,4-dimethyl valeronitrile) as a peroxyradical generator and BODIPY C11 581/591 as the target Analyses were conducted in bovine serum supplemented with water - and lipid - soluble antioxidants and in human plasma. Albumin (0.5$\sim$5 g/dL) and uric acid (0.1$\sim$0.5 $\mu$mol/L) increased hydrophilic ORAC values in a dose-dependent fashion ($R^{2}$=0.97 and 0.98, respectively) but had no impact on lipophilic ORAC values. $\alpha$-Tocopherol (15$\sim$200 $\mu$mol/L) increased lipophilic ORAC values in a dose-dependent fashion ($R^{2}$=0.94); neither $\alpha$-tocopherol nor $\beta$-carotene had an impact on hydrophilic ORAC values. However, addition of $\beta$-carotene at physiological concentration (0.23$\sim$1.86 $\mu$mol/L), either alone or in combination with other carotenoids, had no significant impact on lipophilic ORAC values. Thus, while assays of 'total antioxidant capacity' in biological matrices would be a useful research and clinical tool, existing methods are limited by the lack of complete responsiveness to the full range of dietary antioxidants.

• Mass Spectrometry Letters
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• v.10 no.1
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• pp.18-26
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• 2019

We developed a bioanalytical method for simultaneous determination of nine NBOMe derivatives (25H-NBOMe, 25B-NBOMe, 25E-NBOMe, 25N-NBOMe, 25C-NBOH, 25I-NBOH, 25B-NBF, 25C-NBF, and 25I-NBF) in human plasma using liquid chromatography tandem mass spectrometry (LC-MS/MS). Human plasma samples were pre-treated using solid-phase extraction. Separation was achieved on a C18 column under gradient elution using a mobile phase containing 0.1% formic acid in acetonitrile and 0.1% formic acid in water at a flow rate of 0.3 mL/min. Mass detection was performed in the positive ion mode using multiple reaction monitoring. The calibration range was 1-100 ng/mL for all quantitative analytes, with a correlation coefficient greater than 0.99. The intra- and inter-day precision and accuracy varied from 0.85 to 6.92% and from 90.19 to 108.69%, respectively. The recovery ranged from 86.36 to 118.52%, and the matrix effects ranged from 27.09 to 99.72%. The stability was acceptable in various conditions. The LC-MS/MS method was validated for linearity, accuracy, precision, matrix effects, recovery and stability in accordance with the FDA guidance. The proposed method is suitable for reliable and robust routine screening and analysis of nine NBOMe derivatives in forensic field.

• Journal of Pharmaceutical Investigation
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• v.35 no.6
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• pp.461-465
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• 2005

A simple HPLC method with ultraviolet detection of nicardipine in human plasma was developed and validated. After drug extraction with solid phase extraction (SPE) method, chromatographic separation of nicardipine in plasma was achieved at $30^{\circ}C$ with a $C_{18}$ column and acetonitrile-0.02% phosphate buffer mixture (with 0.02% triethylamine, final pH 7.0), as mobile phase. Quantitative determination was performed by ultraviolet detection at 254 nm. The method was specific and validated with a limit of quantification of 5 ng/mL. The intra- and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification. The applicability of the method was demonstrated by analysis of plasma after oral administration of a single 40 mg dose to 8 healthy subjects. From the plasma nicardipine concentration versus time curves, the mean $AUC_{t}$, was $134.04{\pm}59.72\;ng\;hr/mL$ and $C_{max}$ of $108.65{\pm}69.17\;ng/mL$ reached 1.5 hr after administration. The mean biological half-life of nicardipine was $3.93{\pm}0.82\;hr$. Based on the results, this simple and validated assay method could readily be used in any pharmacokinetic or bioequivalence studies using human.

• Nutritional Sciences
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• v.8 no.2
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• pp.97-103
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• 2005

The goal of this study was to investigate abnotmalities in camitine metabolism present by determining blood camitine and lipid concentrations in Korean diabetic patients. The study subjects included 108 Korean diabetic patients (64 males and 44 females) who were hospitalized in Chonbuk National University Hospital and 27 subjects were also hospitalized as non-diabetic controls (10 males and 17 females). Glucose, total cholesterol, triglyceride (TG) and HDL-cholesterol in plasma were enzymatically assayed and insulin was measured by immunoradiometric assay. Nonesterified camitine (NEC), acid-soluble acylcarnitine (ASAC), and acid-insoluble acylcarnitine (AIAC) were determined by a modified radioisotopic method Glucose and insulin levels were significantly elevated in diabetic patients compared with controls. Total cholesterol was elevated in female but not male diabetic patients and triglycerides were elevated both in male and female diabetics. Plasma and urinary total carnitine (TCNE) were significantly elevated in diabetics as compared with normal controls. In male diabetics, NEC concentrations were significantly elevated above controls, but not in female subjects. Plasma NEC and TCNE concentrations were significantly increased in male diabetics, but significantly decreased in female diabetics. All urinary carnitine concentrations were significantly increased in diabetics as compared with controls. Urinary NEC concentrations were four times higher in male diabetics and three times higher in female diabetics than in controls. The ratios of serum and urinary acylcarnitine/NEC were also significantly higher in diabetics than in controls. This study suggested that there was a remarkable abnormality in lipid and carnitine metabolism in Korean diabetic patients, and the further study on carnitine metabolism and the effects of carnitine supplementation for Korean diabetic patients are needed.

• YAKHAK HOEJI
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• v.54 no.4
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• pp.295-299
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• 2010

The aim of this study was to develop and validate for determination of alibendol in human plasma by HPLC method. After precipitation of 500 ${\mu}l$ plasma samples by 50% methanol 50 ${\mu}l$ and 60% perchloric acid 30 ${\mu}l$ and the supernatant 50 ${\mu}l$ was injected into HPLC. The assay was performed isocratically using 10 mM potassium phosphate (pH 3.0) and acetonitrile (80 : 20, v/v) as mobile phase. The $C_{18}$ column (particle size $3.5{\mu}m$, $4.6{\times}50$ mm, Zorbax Eclipse) was used as a solid phase. The mobile phase was delivered at a flow-rate of 1.7 ml/min, detection was by ultraviolet absorption at 232 nm and concentrations were calculated on the basis of peak areas. In these conditions, alibendol can be separated from ethylparaben, the internal standard, and endogenous substances. The retention times of alibendol and ethylparaben were just about 2.6 and 3.5 minutes, respectively. This rapid HPLC method was validated by examining the precision and accuracy for inter- and intra-day analysis. The standard curve was linear ($R^2$=1.0000) over the concentration range of 0.05~20 ${\mu}g$/ml. The inter-day relative standard deviation (R.S.D.) and accuracy were 0.2~12.2% and 94.4~101.2% (82.7% at the lower limit of quatitation). The intra-day R.S.D. and accuracy were 0.1~11.8% and 98.8~102.5%, respectively. The method was successfully applied to the determination of alibendol in plasma for a pharmacokinetic study.

• Journal of Nutrition and Health
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• v.41 no.6
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• pp.518-529
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• 2008

Lactating women have an increased need of folate in the breastfeeding period and, as a consequence, may be in risk of folate deficiency. Folate content of breast milk, furthermore, is important for infants to support exponential growth. However, little is known about the folate content of breast milk from Korean lactating women and their folate nutritional status. In this study, therefore, we investigated the folate status of Korean lactating women and the folate content of their breast milk during extended lactation. A total of 10 subjects who delivered full-term infants participated this study voluntarily. Dietary folate intakes were measured and blood and breast milk were collected at 1, 2, 3, and 6 months postpartum. The women who did not take folic acid supplements failed to meet the recommended intake(RI) of folate for lactating women during all the study periods but those who did met the RI. The unsupplemented women showed lower plasma folate concentrations compared to the supplemented women and all the women were in suboptimal folate status determined by plasma folate concentration throughout the study periods. But the supplemented women showed lower prevalence of suboptimal folate status only at 3 or 6 months postpartum. Plasma folate concentrations of both groups decreased with the progression of lactation. Erythrocyte folate concentrations were not different between the two groups, however, that of the unsupplemented reduced further as time progressed. Plasma homocysteine levels were not different between the two groups. Concentrations of erythrocyte folate and plasma homocysteine were not changed throughout the study periods. Folate contents of their breast milk through the study periods were not different between the two groups and it decreased as lactation progressed in both groups. The results of this study suggest that the folate nutritional status of Korean lactating women might be deteriorated with the progression of lactation without folic acid supplements.