• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6663-6668
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• 2015

Background: Treatment failure in leukemia is due to either pharmacokinetic resistance or cell resistance to drugs. Materials and Methods: Gene expression of multiple drug resistance protein (MDR-1), multidrug resistance-related protein (MRP) and low resistance protein (LRP) was assessed in 45 pediatric ALL cases and 7 healthy controls by real time PCR. The expression was scored as negative, weak, moderate and strong. Results: The male female ratio of cases was 2.75:1 and the mean age was 5.2 years. Some 26/45 (58%) were in standard risk, 17/45(38%) intermediate and 2/45 (4%) in high risk categorie, 42/45 (93%) being B-ALL and recurrent translocations being noted in 5/45 (11.0%). Rapid early response (RER) at day 14 was seen in 37/45 (82.3%) and slow early response (SER) in 8/45 (17.7%) cases. Positive expression of MDR-1, LRP and MRP was noted in 14/45 (31%), 15/45 (33%) and 27/45 (60%) cases and strong expression in 3/14 (21%), 11/27 (40.7%) and 8/15 (53.3%) cases respectively. Dual or more gene positivity was noted in 17/45 (38%) cases. 46.5 % (7/15) of LRP positive cases at day 14 were in RER as compared to 100% (30/30) of LRP negative cases (p<0.05). All 8 (100%) LRP positive cases in SER had strong LRP expression (p=<0.05). Moreover, only 53.3% of LRP positive cases were in haematological remission at day 30 as compared to 100% of LRP negative cases (p=<0.05). Conclusions: Our study indicated that increased LRP expression at diagnosis in pediatric ALL predicts poor response to early treatment and hence can be used as a prognostic marker. However, larger prospective studies with longer follow up are needed, to understand the clinical relevance of drug resistance proteins.

• Korean Journal of Clinical Pharmacy
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• v.27 no.2
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• pp.83-91
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• 2017

Background: Piperacillin/tazobactam (TZP) is an antibiotic against a broad spectrum of gram-positive, gram-negative, and aerobic and anaerobic strains of bacteria. Due to changes in its pharmacokinetic and pharmacodynamic parameters by TZP-treated patients' renal functions and obesity, it is important to administrate and monitor TZP based on their renal functions and Body Mass Index (BMI) levels. The purpose of this study was to determine the appropriateness of administration doses of TZP based on renal functions of obese cancer patients in a tertiary hospital. Methods: This study was retrospectively conducted with obese cancer patients with $BMI{\geq}30kg/m^2$ in a tertiary hospital, Korea from September 2004 to August 2014. Data were collected through Electronic Medical Record (EMR) which contained laboratory data and TZP dosing of each patient. Results: Among 7,058 patients during the study period, 102 prescriptions were selected based on inclusion and exclusion criteria and classified by their renal functions. Although TZP should be used based on patients' renal functions to adjust its dose, its initial dose and dosing interval were consistently used without considering patients' renal functions on a regular basis. Especially, in the comparison with FDA dosing standard of TZP, approximately twice patients with $20mL/min{\leq}CrCl{\leq}40mL/min$ received domestically 4.5 g instead of 2.25 g as the TZP starting dose. Conclusion: The appropriate doses of TZP were administered to almost all of obese cancer patients; however, the recommended TZP dose was different between Korea and other countries by twice the amount. Further related studies are necessary to clearly determine the results, to optimize TZP treatment for obese patients with cancer in clinical practice, and to design and develop new TZP formulations for them in pharmaceutical industry.

• Analytical Science and Technology
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• v.15 no.5
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• pp.410-416
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• 2002

In this study, a new quantitative analytical method has been developed for the rapid determination of vancomycin in human plasma and urine using liquid chromatography/tandem mass spectrometry (LC - MS/MS). Chromatography was carried out on a $C_{18}$ XTerra MS column ($2.1{\times}30mm$) with a particle size of $3.5{\mu}m$. The mobile phase was 0.25% formic acid in 10% acetonitrile and the flow rate was $250{\mu}L/min$. Vancomycin and caffeine (internal standard) were detected by MS/MS using multiple reaction monitoring (MRM). Vancomycin gives a predominant doubly protonated precursor molecule ($[M+2H]^{2+}$) at m/z 725.0 and a corresponding product ion of m/z 100.0. Detection of vancomycin was good, accurate and precise, with a limit of detection of 1 nM in plasma. The calibration curves for vancomycin in human plasma was linear in a concentration range of $0.01{\mu}M$ - $100{\mu}M$ for plasma. This method has been successfully applied to determine the concentration of vancomycin in human plasma and urine from pharmacokinetic study and relative studies.

• Journal of Society of Preventive Korean Medicine
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• v.17 no.1
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• pp.77-88
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• 2013

Objectives : This study was aim to evaluate effects of pharmacodynamics and toxicity in combination therapy of donepezil with Gongjindan. Methods : After 10mg/kg of donepezil treatment, Gongjindan 100mg/kg was administered within 5 min. The plasma were collected at 30min before administration, 30min, 1, 2, 3, 4, 6, 8 and 24hrs after end of Gongjindan treatment, and plasma concentrations of donepezil were analyzed using LC-MS/MS methods. PK parameters of donepezil were analysis as compared with donepezil single administered rats. Results : Gongjindan markedly inhibited the absorption of donepezil regardless of sample time, from 30min to 8hrs after end of co-administration comparing with donepezil single treated rats. Especially the absorption of donepezil was significantly decreased at 2hrs after co-administration as compared with donepezil single treated rats, in the present study. Accordingly, the Cmax(-27.76%), $AUC_{0-t}$(-27.22%) and $AUC_{0-inf}$(-26.54%) of donepezil in co-administered rats were significantly decreased as compared with donepezil single treated rats, respectively. Conclusions : Based on the results of the present study, co-administration of Gongjindan decreases the oral bioavailability of donepezil by inhibiting the absorption. It is considered that the more detail pharmacokinetic studies should betested to conclude the effects of Gongjindan on the pharmacokinetics of donepezil, when they were co-administered, like the effects after co-administration with reasonable intervals considering the Tmax of donepezil and after repeated co-administrations.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.11a
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• pp.99-113
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• 1996

Taurine, a ${\beta}$-amino acid, plays an important role as a neuromodulator and is necessary for the normal development of the brain. Since de novo synthesis of taurine in the brain is minimal and in vivo studies suggest that taurine does not cross the blood-brain barrier, the blood-cerebrospinal fluid (CSF) barrier is likely to play a role in taurine transport between the central nervous system and the systemic circulation. Therefore, we examined in vivo elimination of taurine from the CSF in the rat to characterize in vivo kinetics of elimination for taurine from the CSF is consistent with the in vitro study. Using a stereotaxic device, cannulaes were placed into the lateral ventricle and the cisterna magna of the rat. Radio-labelled taurine and inulin (a marker of CSF flow) were injected into the lateral ventricle, and the concentrations of the labelled compounds in the CSF were monitored for up to 3 hrs in the cisterna magna. The apparent clearance of taurine from CSF was greater than the estimated CSF flow (p<0.005), indicating that there is a clearance process in addition to the CSF flow. Taurine distribution into the choroid plexus was at least 10 fold higher than that found in other brain areas (e.g., cerebellum, olfactory bulb and cortex). When unlabelled taurine was co-administered with radio-labelled taurine, the apparent clearance of the labeled taurine was reduced (p<0.01), suggesting a saturable disposition of taurine from CSF. Distribution of taurine into the choroid plexus, cerebellum, olfactory bulb and cortex was similarly diminished, indicating that the saturable uptake of taurine into these tissues is responsible for the non-linear disposition. A pharmacokinetic model involving first order elimination and saturable distribution described these data adequately. The Michaelis-Menten rate constant estimated from in vivo elimination study is similar to that obtained in the in vitro uptake experiment Collectively, our results demonstrate that taurine is transported in the choroid plexus via a taurine is cleared from the CSF via a saturable process. This process may be functionally relevant to taurine homeostasis in the brain.

• Biomolecules & Therapeutics
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• v.28 no.4
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• pp.311-319
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• 2020

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a newly emerging viral disease with fatal outcomes. However, no MERS-CoV-specific treatment is commercially available. Given the absence of previous structure-based drug discovery studies targeting MERS-CoV fusion proteins, this set of compounds is considered the first generation of MERS-CoV small molecule fusion inhibitors. After a virtual screening campaign of 1.56 million compounds followed by cell-cell fusion assay and MERS-CoV plaques inhibition assay, three new compounds were identified. Compound numbers 22, 73, and 74 showed IC₅₀ values of 12.6, 21.8, and 11.12 µM, respectively, and were most effective at the onset of spike-receptor interactions. The compounds exhibited safe profiles against Human embryonic kidney cells 293 at a concentration of 20 µM with no observed toxicity in Vero cells at 10 µM. The experimental results are accompanied with predicted favorable pharmacokinetic descriptors and drug-likeness parameters. In conclusion, this study provides the first generation of MERS-CoV fusion inhibitors with potencies in the low micromolar range.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.74-74
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• 1993

The in vitro cytotoxicity of SKI 2053R was evaluated against human tumor cell lines along with those of cisplatin and carboplatin using MTT assay. The cell lines tested were two human lung cancer cell lines and five human stomach cancer celt lines. The level of cytotoxic effects of SKI 2053R against two human lung cancer cell lines was located between cisplatin and carboplatin. However, the cytotoxic activity of SKI 2053R against five human stomach cancer cell lines was similar to that of cisplatin. SKI 2053R is considered to be selectively cytotoxic toward human stomach cancer cell lines. We carried out pharmacokinetic and ex vivo phrmacodynamic studies of SKI 2053R in beagle dogs to predict the clinical antitumor effect of SKI2053R, comparing with those of cisplatin and carboplatin. In ex vivo pharmacodynamics which used MTT assay as bioassay on the 2 lung and 5 stomach cancer cell, mean antitumor indexes (ATIs) of SKI 2053R were highest among three compounds in both lung and stomach cancer cell lines, especially in stomach cancer cell. Much higher ATI profile and maximal inhibition rates of SKI 2053R appeared in the stomach cancer cells will give desirable advantages to clinical trial s against gastric carcinoma. The anti tumor activity and target organ toxicity of SKI 2053R were compared with those of cisplatin on stomach cancer cell line, KATO III xenografted into nude BALB/c(nu/nu) mice. All groups of cisplatin and SKI 2053R showed active tumor regression. The inhibition rates(IR) of SKI 2053R were higher than that of cisplatin on the basis of mean IR. Though the loss of body weight was observed in all groups from the first week, the SKI 2053R group recovered it soon from the third week after the initiation of treatment, maintaining the most active anti tumor activity among three groups.

• Journal of Pharmaceutical Investigation
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• v.39 no.5
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• pp.321-325
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• 2009

5-HT$_{2C}$ receptors have been considered as therapeutic targets for the treatment of various central nervous system disorders such as depression, anxiety, epilepsy, schizophrenia and sleep disorders. We chemically synthesized KKHQ80114 (K14) and KKHQ80109 (K09), selective 5-HT$_{2C}$ agonists, with the purpose of developing therapeutic agents for the treatment of obesity. The objective of this work is to investigate analytical methods of these compounds in the plasma and urine of rats by gas chromatography/mass spectrometry. In this experiment, K14 was determined in plasma and urine by using K09 as internal standard. Calibration curves give a good linearity in plasma (r$^2$=0.9993) and urine (r$^2$=0.9988). Among hexane, ethyl acetate and diethyl ether, the highest peak was observed in diethyl ether. However, ethyl acetate was used since more interfering peaks were observed with diethyl ether. Inter-day precision and accuracy were determined in the ranges of 50-500 ng/mL for plasma and 10-500 ng/ml for urine. Quantitation limits were 50 ng/mL plasma and 25 ng/ mL urine. These data may be applicable for further studies of these compounds including absorption and metabolism due to no pharmacokinetic or analytical data available.

• The Journal of Korean Medicine
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• v.37 no.2
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• pp.1-11
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• 2016

Objectives: The objective of this study was to elucidate the effect of Jaeumkanghwatang (JEKHT) on the plasma concentration and pharmacokinetics of tamoxifen in combination therapy as a process of the comprehensive and integrative medicine against breast cancer. Methods: After 50 mg/kg of tamoxifen treatment, JEKHT 100 mg/kg was orally administered within 5 min. The plasma were collected at 30 min before administration, 30min, 1, 2, 3, 4, 6, 8 and 24 hrs after end of JEKHT treatment, and plasma concentrations of tamoxifen were analyzed using LC-MS/MS methods. PK parameters of tamoxifen ($T_{max}$, $C_{max}$, AUC, $t_{1/2}$ and $MRT_{inf}$) were analysis as compared with tamoxifen single administered rats. Results: JEKHT did not influenced on the plasma concentrations and pharmacokinetics of tamoxifen after single oral co-administration, within 5min except for some negligible effects on plasma concentration. The $T_{max}$, $C_{max}$, AUC, $t_{1/2}$ and $MRT_{inf}$ of tamoxifen in co-administered rats were quite similar to those of tamoxifen single treated rats. Conclusions: Based on the results of the present study, JEKHT did not influenced on the oral bioavailability of tamoxifen, when they were single co-administered within 5min. However, more detail pharmacokinetic studies should be tested to conclude the possibilities that can be used as comprehensive and integrative therapy with JEKHT and tamoxifen for breast cancers, when they were co-administered, like the effects on the pretreatment of JEKHT and after repeat co-administrations.

• Journal of Pharmaceutical Investigation
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• v.34 no.3
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• pp.161-168
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• 2004

5-Fluorouracil (5-FU) is an antimetabolite anticancer agent active against many types of solid tumors. Tegafur (TF), a prodrug of 5-FU, is frequently used in combination with uracil as dihydropyrimidine dehydrogenase (DPD) inhibitory fluoropyrimidine. We studied the stability of 5-FU and TF in biological fluids of rats and determined their bioavailability (BA) and excretion into bile, and urine. The drug concentrations were analyzed by an HPLC method. At room temperature, there was a 14-30% decrease in the concentration of 5-FU and TF in bile, urine, and plasma specimen at 10 and $100\;{\mu}g/ml$ over 240 min. No significant difference was noted among the sample types or between two different concentrations of 10 and $100{\mu}g/ml$. The decrease in drug concentration was significantly less in samples kept on ice (6-12%) for both drugs. These data indicate that biological fluid samples containing 5-FU or TF in plasma, urine, or bile should be placed on ice during the sample collection. Following these storage guidelines, samples were collected after administration 50 mg/kg of each drug via i.v. or oral route. BA was 1.5 folds greater for TF (60%) than that of 5-FU (42%). Approximately 0.52 and 3.3% of the i.v. doses of 5-FU and TF was excreted into bile, respectively. Renal clearance of 5-FU was about 16% of its total body clearance. These results suggest that instability of 5-FU and TF in biological fluids should be considered in pharmacokinetic or pharmacogenomic studies.