• Archives of Pharmacal Research
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• v.18 no.5
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• pp.340-345
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• 1995

A nebumetone tablet in development $(Navuton^R)$ was tested for its bioequivalence to the erference tablet $(Uniton^R)$. Seventeen healthy Korean male subjects participated in this study. Each subject received a 1-g dose of nabumetone (2tables each) in an unbalanced, randomized, two-way crossover investigation. Serum concentrations of 6-methoxy-2-na-phthylacetic acid (6-MNA), a major metabolite of nebumetone, were measured over 120 hr interval by a high-performance liquid chromatography. The maximum serum concentration $(C_{max})$ and time to reach the maximum concentration$(T_{max})$ were read directly, but area under the serum concentration time curve from time 0 to 120 hr (AUC) and mean residence time serum curves showed multiple peaks of 6-MNA in most subjects, and the $C_{max}$ and $T_{max}$ were read from the highest serum peaks. calculated bioavailability parameters for test and reference tablets were 148.6 : 1377.9 $\mug \cdot hr/ml$ for AUC; 25.2:23.1 $\mu/ml$ for $C_{max}$; 11.8:16.4 hr for $T_{max}$, and 42.6 : 43.8 hr for MRT, respectively. The paired t-test revealed no significant differences in all the parameters between the two tablets. Analysis ofl variance (ANOVA) revealed no significant differences between groups and formulations in all the parameters ($C_{max}$ and $T_{max}$, AUC and MRT) indicating the crossover design of the experiment was properly performed. But significant differences (p<0.05) between subject/groups and periods were found for all the parameters indicating substantial intersubject and interperiodic variations for these parameters.

• Journal of Life Science
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• v.21 no.4
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• pp.534-541
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• 2011

Retinoic acid (RA), a metabolite of vitamin A, is known to regulate dedifferentiation of rabbit articular chondrocytes. The regulatory mechanism of dedifferentiation by RA is not yet understood. Thus, the effect of RA on the regulation of nitric oxide (NO)-induced dedifferentiation was investigated in rabbit articular chondrocytes. RA caused loss of the differentiated chondrocyte phenotype as demonstrated by inhibition of type II collagen expression and proteoglycan synthesis. RA also accelerated NO-induced dedifferentiation in rabbit articular chondrocytes as detected by expression of type II collagen and Sox-9 using Western blot analysis and production of sulfated proteoglycan using Alcain blue staining. Further, RA potentiated NO-induced activation of ERK. Inhibition of ERK with PD98059 (PD) recovered the expression of type II collagen and Sox-9 and production of sulfate proteoglycan in NO-induced dedifferentiated chondrocytes by RA treatment. Our findings suggest that RA accelerates NO-induced dedifferentiation of rabbit articular chondrocytes via the ERK pathway.

• YAKHAK HOEJI
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• v.42 no.5
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• pp.513-518
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• 1998

Fluoxetine is a nontricyclic antidepressant which blocks serotonin reuptake selectively. Its N-demethyl metabolite, norfluoxetine is also selective inhibitor of serotonin uptake . This study was carried out to compare the bioavailability of Myung-in fluoxetine (20mg/cap.) with that of Prozac$^{\circde{R}}$. The bioavailability was conducted on 24 healthy volunteers who received a single dose (80mg) of each drug in the fasting state, in a randomized balanced 2-way crossover design. After closing, serial blood samples were collected for a period of 48 hours, Plasma was analyzed for fluoxetine and norfluoxetine by a sensitive and validated HPLC assay. The major pharmacokinetic parameters ($AUC_{0-48\;hr}$, Cmax, Tmax , $AUC_{inf.}$, MRT. $T_{1/2}$, Vd and Cl) were, calculated from the plasma fluoxetine concentration-time data of each volunteer. The microcomputer program, 'WinNonlin' was used for compartmental analysis. A two-compartment model with first-order input, first-order output and no lag time was chosen as the most appropriate pharmacokinetic model. The data were best described by using a weighting factor of $1/y^2$. Though the plasma fluoxetine concentrations of Myung-in fluoxetine were higher than those of Prozac$^{\circde{R}}$ at all observed time from 7.9% to 16.9% (P<0.05 at 6.7 and 10 hr), the bioavailability of Myung-in fluoxetine appeared to be bioequivalent with that of Prozac$^{\circde{R}}$. There were no statistical significant differences between the two drugs in all pharmacokinetic parameters including $AUC_{0-48\;hr}$ of norfluoxetine.

• YAKHAK HOEJI
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• v.42 no.5
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• pp.473-479
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• 1998

Lovastatin (LOVA), a fungal metabolite isolated from cultures of Aspergillus terreus, is a competitive HMG-CoA reductase inhibitor used for the treatment of primary hyper cholesterolemia, and has also been shown to suppress growth in a variety of non-glioma tumor cell lines. A sensitive reversed-phase high-perfonnance liquid chromatographic method with ultraviolet (UV) absorbance detection has been developed to quantitate LOVA in human plasma and urine samples using liquid-liquid extraction procedure. Baseline separation of LOVA and internal standard, simvastatin was achieved on a Novapak $C_{18}$ analytical column with a mobile phase containing 0.025M $NaH_2PO_4$: CAN (35:65, v/v%), adjusted pH to 4.5. The flow rate was set at 1.5ml/min, and the column effluent was monitored by a UV detection at 238nm. The limit of quantification was determined to be 0.5${\mu}$g/ml while extraction efficiency of LOVA ranged from 73.4-82.9% at LOVA concentrations of 0.5 to 10${\mu}$g/ml. Good linearity with correlation coefficients greater than 0.999 was obtained in the range of LOVA concentrations from 0.5 to 10${\mu}$g/ml. The accuracy and the precision were proven excellent with relative standard deviation (RSD, %) and relative error (RE, %) of less than 4.2 and 4.0, respectively. Intraday precision, evaluated at five LOVA concentrations (0.5, 1, 2, 5, 10${\mu}$g/ml) and expressed as RSD ranged from 0-1.82% while the interday precision at the same concentrations ranged from 0.7-10.5%. The analytical method described was then successfully employed for the determination of LOVA concentrations in plasma samples obtained during a phase II clinical trial using high doses of LOVA (30-40mg/kg/day). This method could be further utilized for the ongoing pharmacolkinetic studies and therapeutic drug monitoring of the high-dose LOVA therapy in adenocarcinoma patients.

• Korean Journal of Clinical Pharmacy
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• v.3 no.1
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• pp.79-88
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• 1993

Bioequivalence(BE) test of commercially available sustained release tablets of diltiazem hydrochloride(DTZ) was performed to give some guidelines to BE test in korea in case of which drugs with low oral bioavaiiability(BA) due to substantial first-pass hepatic loss form pharmacologically active metabolites. In such cases, the pharmacologic activity after oral administration is greater than anticipated from BA data, based on chemical assay of drug alone. Therefore, this paper explores the use and meaning of area under the plasma concentration-time(AUC) data of parent and its metabolites to access BA if sustained release tablets. Normal healthy male volunteers(n=14) were randomly divided into 2 groups, and sustained release reference$(Herbesser^{(R)})$ and test$(Herben^{(R)})$ tablets of DTZ-30mg were given orally by balanced two-period cross-over dosing schedule. The plasma concentration of DTZ and and its active metabolite, desacetyldiitiazem(DAD), were determined by high performance liquid chromatography, and, $AUC_{DTZ},\;AUC_{DAD},\;AUC_{DTZ+DAD},\;C_{max}\;and\;T_{max}$ obtained. Analysis of varlance(ANOVA) showed that $AUC_{DTZ}\;and\;C_{max}$ passed the standard $(\alpha=0.05,\;1-\beta\geq0.8,\;\Delta\leq0.2)$ of BE test of korea, but $AUC_{DAD}$ was not satisfied from the standpoint of power. On the other hand, $AUC_{DTZ\midDAD}$ may be more avaliable than $AUC_{DAD}$ from the standpoint of statistics and pharmacologic equivalence.

• Journal of Pharmaceutical Investigation
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• v.26 no.4
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• pp.309-314
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• 1996

The purpose of this study is to explain the relationship between the pharmacological mechanism of levamisole and the cellular activity of cellular alkaline phosphatase (ALPase) in kidney cells. The results of our investigation were as follows. 1. Cellular ALPase activity in Macacus rhesus monkey kidney cells (MA 104 cells) and primary cultured rabbit kidney proximal tubular cells treated with levamisole was increased about two or three times than control. However, 50% of ALPase activity in cultured medium was inhibited by levamisole itself. 2. The proliferation of MA 104 and cultured rabbit kidney proximal tubular cells was linearly decreased in paralleled with increase of levamisole concentration $(50\;and\;500\;{mu}M)$ with MTT test. 3. In the heat stability tests, the inhibition of ALPase activity with and without levamisole at $56^{\circ}C$ in MA 104 cells showed different $IC_{50}$ values. 4. HPLC analysis of levamisole metabolites produced by cultured MA 104 cells suggested that the formation of a metabolite, that may be associated with its increase of cellular ALPase activity. Based on these results, we assumed that the increase of cellular ALPase activity by levamisole was evoked by modification of the ALPase catalytic sites.

• Microbiology and Biotechnology Letters
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• v.40 no.1
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• pp.10-16
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• 2012

The Streptomyces peucetius OIM (Overproducing Industrial Mutant) strain is a recursively-mutated and optimally-screened strain used for the industrial production of polyketide antibiotics, such as doxorubicin (DXR). Using the S. peucetius OIM mutant strain as a surrogate host, a model minimal polyketide pathway for aloesaponarin II, an actinorhodin shunt product, was cloned in a high-copy conjugative plasmid, followed by functional pathway expression and quantitative metabolite analysis. The level of aloesaponarin II production was noted as being significantly higher in the OIM strain than in the wild-type S. peucetius, as well as in the regulatory network-stimulated S. coelicolor mutant strain. Moreover, the aloesaponarin II production level was seen to be even higher in a down-regulator $wblA_{spe}$-deleted S. peucetius OIM strain, implying that the rationally-engineered S. peucetius OIM mutant strain could be used as an efficient surrogate host for the high expression of foreign polyketide pathways.

• Journal of Microbiology and Biotechnology
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• v.22 no.2
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• pp.256-263
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• 2012

A strain of bacterium producing antifungal antibiotic was isolated and identification of the strain was attempted. We could identify the bacterium as being a Bacillus sp., based on morphological observation, physiological characteristics, and 16S rDNA sequence analysis, thus leading us to designate the strain as Bacillus sp. AH-E-1. The strain showed potent antibiotic activity against phytopathogenic and human pathogenic fungi by inducing mycelial distortion and swelling and inhibiting spore germination. The antibiotic metabolite produced by the strain demonstrated excellent thermal and pH (2-11) stability, but was labile to autoclaving. From these results, we could find a broader antifungal activity of Bacillus genus. Isolation and characterization of the active agent produced by the strain are under progress.

• Toxicological Research
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• v.28 no.4
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• pp.269-277
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• 2012

The purpose of this study was to understand the mechanism of cardiovascular disease (CVD) caused by exposure to hazardous chemicals. We investigated changes in the symptoms of metabolic syndrome, which is strongly related to CVD, and in levels of other CVD risk factors, with a special emphasis on the roles of catecholamines and oxidative stress. The results revealed that neither body mass index (BMI) nor waist and hip circumferences were associated with exposure to hazardous chemicals. Among metabolic syndrome criteria, only HDL-cholesterol level increased on exposure to hazardous chemicals. Levels of epinephrine (EP) and norepinephrine (NEP) were not influenced by exposure to hazardous chemicals; however, the total antioxidative capacity (TAC) reduced because of increased oxidative stress. Both hazardous chemical exposure level and metabolite excretion were related to EP, NEP, and the oxidative stress index (OSI). Logistic regression analysis with these factors as independent variables and metabolic syndrome criteria as dependent variables revealed that EP was associated with blood pressure, and NEP with metabolic syndrome in the chemical-exposed group. In conclusion, the results suggest that reactive oxygen species generated and oxidative stress due to exposure to hazardous chemicals act as mediators and cause changes in the physiological levels of EP and NEP to increase blood pressure. This ultimately leads to the development of CVD through increase in cholesterol, triglyceride, and blood glucose levels by lipid peroxidation.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.531-535
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• 2017

In this study, Leuconostoc mesenteroides CJNU0041 was isolated from Korean traditional food kimchi and antimicrobial activity of fermented broccoli with the isolate was tested against pathogenic Clostridium difficile. L. mesenteroides CJNU0041 showed higher glucosidase activity than other isolates. As the results of physiological properties such as pH and viable cell count during broccoli fermentation with L. mesenteroides CJNU0041, we confirmed that 48 hours was optimal fermentation time. As the results of metabolite analysis by HPLC, metabolites were changed during the fermentation. Especially, the growth of C. difficile was inhibited by the fermented broccoli. Therefore, L. mesenteroides CJNU0041 might be a candidate for improving the functionality of natural materials by lactic acid fermentation.