• Toxicological Research
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• v.18 no.3
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• pp.227-232
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• 2002

In order to find out the appropriate in vitro method for high correlation with in vivo, we com-pared the sensitivities of phototoxicity (PT) in vitro method between in human keratinocytes, HaCaT cells and in 3T3 fibroblast cells derived from Balb/c mice. Both cells were exposed to six known phototoxic chemicals : promethazine, neutral red, chlortetracycline, amiodarone, bithionol, 8-methoxypsoralen, or non-phototoxic chemical, ALS (ammonium laureth sulfate) and then irradiated with 5 J/$cm^2$ of UVA. Cell viability ($IC_{50}$ ) was measured by neutral red uptake (NRU) assay. The ratio of $IC_{50}$ value of chemicals in the presence and absence of UVA was determined by the cut-off value. The phototoxic potential of test chemicals in NRU assay was determined by measuring the photoirriation factor (PIF) with a cut-off value of 5. In both 3T3 and HaCaT cells, all known phototoxic chemicals were positive (over 5 of PIF value), except that bithionol was found to be non-phototoxic to HaCaT cells, and ALS, non-phototoxic chemical was negative. These results suggest that Balb/c 3T3 cell was more sensitive than HaCaT cell to predict phototoxicity potential.

• Journal of Food Hygiene and Safety
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• v.11 no.4
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• pp.307-314
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• 1996

The European Economic Community four plate test(EEC 4-plate test, FPT, EU) has been used for monitoring antimicrobial drug residues in meat by Local Veterinary Service Center in Korea. This study was performed to evaluate sensitivity and group specificity of some antimicrobial drugs in FPT and to compare FPT with Charm II test. The minimal detectable levels of targeted antimicrobial drugs tested with standard solutions were 0.025∼1.0 ppm for 7 beta-lactams, 0.5∼1.0 ppm for 4 aminoglycosides, 0.05∼0.5 ppm for 5 macrolides, 0.05∼0.25 ppm for 3 tetracyclines and 0.25&1.0 ppm for 6 sulfonamides. In comparison of FPT and Charm II test, the results of FPT were not accord with those of Charm II test having the group specificity of seven families of antimicrobial drugs in meat samples except some families like tetracyclines.

• Biomolecules & Therapeutics
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• v.30 no.3
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• pp.238-245
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• 2022

Previous reports have demonstrated that genetic mechanisms greatly mediate responses to drugs of abuse, including methamphetamine (METH). The circadian gene Period 2 (Per2) has been previously associated with differential responses towards METH in mice. While the behavioral consequences of eliminating Per2 have been illustrated previously, Per2 overexpression has not yet been comprehensively described; although, Per2-overexpressing (Per2 OE) mice previously showed reduced sensitivity towards METH-induced addiction-like behaviors. To further elucidate this distinct behavior of Per2 OE mice to METH, we identified possible candidate biomarkers by determining striatal differentially expressed genes (DEGs) in both drug-naïve and METH-treated Per2 OE mice relative to wild-type (WT), through RNA sequencing. Of the several DEGs in drug naïve Per2 OE mice, we identified six genes that were altered after repeated METH treatment in WT mice, but not in Per2 OE mice. These results, validated by quantitative real-time polymerase chain reaction, could suggest that the identified DEGs might underlie the previously reported weaker METH-induced responses of Per2 OE mice compared to WT. Gene network analysis also revealed that Asic3, Hba-a1, and Rnf17 are possibly associated with Per2 through physical interactions and predicted correlations, and might potentially participate in addiction. Inhibiting the functional protein of Asic3 prior to METH administration resulted in the partial reduction of METH-induced conditioned place preference in WT mice, supporting a possible involvement of Asic3 in METH-induced reward. Although encouraging further investigations, our findings suggest that these DEGs, including Asic3, may play significant roles in the lower sensitivity of Per2 OE mice to METH.

• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.311-316
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• 1999

Background: The drug-resistant tuberculosis has recently decreased in Korea, but it is still one of the major obstacles in the treatment of pulmonary tuberculosis. Unfortunately there are no reliable ways to figure out the drug sensitivity pattern of the M. tuberculosis in the starting point of treatment. At least several months which is critical for the success of treatment have to be passed away before getting the report of drug-sensitivity test. The aim of this study was to find out the clinical and radiological parameters that make it possible to predict the drug-resistant pulmonary tuberculosis and to make a correct decision on the antituberculosis drug regimens. Method: We studied 253 pulmonary TB patients with sputum and/or bronchial washing fluid culture-positive diagnosed at the Chung-Ang University Young-San Hospital in the period of 1989-1994. The differences in the clinical and raiological variables between the drug-sensitive and the drug-resistant tuberculosis patients were evaluated. Results: In 66 out of 253 patients(26.1%), drug resistant tuberculosis to at least one antituberculosis drug were found. Patients with retreatment showed higher resistance rate than those with initial treatment(30/69, 43.5% vs 36/184, 19.5%, p<0.01). Patients with cavitary TB showed higher resistance rate than those with non-cavitary TB(24/54, 44.4% vs 42/199, 21.1%, p<0.05). Among patients with initial treatment, those with far-advanced TB showed a higher drug resistance rate than those with minimal lesion(9/23, 36.9% vs 10/82, 12.5%, p<0.05). Patients with culture positive only in the bronchial washing fluid showed lower resistance rate than those with sputum culture positive(7/63, 11.1 % vs 59/190, 31.1%, p<0.05). Conclusion: Prior treatment history for pulmonary tuberculosis, the presence of cavity & far advanced tuberculosis in the radiologic exam, sputum rather than solely bronchial washing culture positivity would be the related factors to the drug resistance. So in the patients with such characteristics, it is needed to try to find out the drug sensitivity pattern of the infecting tuberculosis organism as soon as possible.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4635-4639
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• 2013

Multi-drug resistance (MDR) is an essential aspect of human lung cancer chemotherapy failure. Recent studies have shown that vinorelbine is involved in underlying processes in human tumors, reversing the MDR inseveral types of cancer cells. However, the roles and potential mechanism are not fully clear. In this study, we explored effects of vinorelbine in multi-drug resistance reversal of human lung cancer A549/DDP cells. We found that vinorelbine increased drug sensitivity to cisplatin and intracellular accumulation of rhodamine-123, while decreasing expression of P-glycoprotein (P-gp), multi-drug resistance-associated protein (MRP1) and glutathione-S-transferase ${\pi}$ (GST-${\pi}$) in A549/DDP cells. At the same time, we also established downregulation of p-Akt and decreased transcriptional activation of NF-${\kappa}B$ and twist after vinorelbine treatment. The results indicated that vinorelbine might be used as a potential therapeutic strategy in human lung cancer.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.268-272
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• 2012

Nephrotoxicity occurs when kidney-specific detoxification and excretion do not work properly due to the damage or destruction of kidney function by exogenous or endogenous toxicants. Exposure to drugs often results in toxicity in kidney which represents the major control system maintaining homeostasis of body and thus is especially susceptible to xenobiotics. Understanding the toxic mechanisms for nephrotoxicity provides useful information on the development of drugs with therapeutic benefits with reduced side effects. Mechanisms for drug-induced nephrotoxicity include changes in glomerular hemodynamics, tubular cell toxicity, inflammation, crystal nephropathy, rhabdomyolysis, and thrombotic microangiopathy. Biomarkers have been identified for the assessment of nephrotoxicity. The discovery and development of novel biomarkers that can diagnose kidney damage earlier and more accurately are needed for effective prevention of drug-induced nephrotoxicity. Although some of them fail to confer specificity and sensitivity, several promising candidates of biomarkers were recently proved for assessment of nephrotoxicity. In this review, we summarize mechanisms of drug-induced nephrotoxicity and present the list of drugs that cause nephrotoxicity and biomarkers that can be used for early assessment of nephrotoxicity.

• Journal of Electrochemical Science and Technology
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• v.9 no.4
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• pp.292-300
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• 2018

The electrocatalytic oxidative behavior of an antiarrhythmic drug, procainamide hydrochloride (PAH) at the gold electrode surface has been examined using different voltammetric methods like cyclic, linear-sweep and differential pulse voltammetry. Voltammograms obtained in this study reveal that the electrode exhibit excellent electrocatalytic activity towards oxidation of the drug. The parameters that can affect the peak current at different pH, scan rate and concentration were evaluated. The number of electrons transferred was calculated. The current displayed a wide linear response ranging from 0.5 to $30.0{\mu}M$ with a limit of detection of 56.4 nM. The impact of potential interfering agents was also studied. The electrode displayed wide advantages such as simple sample preparation, appreciable repeatability, reproducibility and also high sensitivity. Furthermore, the feasibility of the proposed method was successfully demonstrated by determining PAH in the spiked human biological sample.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.54-55
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• 2006

Polymeric micelles, supramolecular assemblies of block copolymers, are useful nanocarriers for the systemic delivery of drugs and genes. Recently, novel polymeric micelles with various functions such as the targetability and stimuli-sensitivity have been emerged as promising carriers that enhance the efficacy of drugs and genes with minimal side effects. This presentation focuses our recent approach to the preparation of functional block copolymers that are useful for constructing smart micellar delivery systems in advanced therapeutics, including chemo-gene therapy. Particular emphasis is placed on the characteristic behaviors of intracellular environment-sensitive micelles that selectively exert drug activity and gene expression in live cells.

• BMB Reports
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• v.51 no.2
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• pp.98-103
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• 2018

Recurrence is a serious problem in patients with bladder cancer. The hypothesis for recurrence was that the proliferation of drug-resistant cells was reported, and this study focused on drug resistance due to drug efflux. Previous studies have identified FOXM1 as the key gene for recurrence. We found that FOXM1 inhibition decreased drug efflux activity and increased sensitivity to Doxorubicin. Therefore, we examined whether the expression of ABC transporter gene related to drug efflux is regulated by FOXM1. As a result, ABCG2, one of the genes involved in drug efflux, has been identified as a new target for FOXM1. We also demonstrated direct transcriptional regulation of ABCG2 by FOXM1 using ChIP assay. Consequently, in the presence of the drug, FOXM1 is proposed to directly activate ABCG2 to increase the drug efflux activation and drug resistance, thereby involving chemoresistance of bladder cancer cells. Therefore, we suggest that FOXM1 and ABCG2 may be useful targets and important parameters in the treatment of bladder cancer.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.180-189
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• 2016

The widespread occurrence of drug-resistant Mycobacterium tuberculosis places importance on the detection of TB (tuberculosis) drug susceptibility. Conventional drug susceptibility testing (DST) is a lengthy process. We developed a rapid enzymatic color-reaction-based biochip assay. The process included asymmetric multiplex PCR/templex PCR, biochip hybridization, and an enzymatic color reaction, with specific software for data operating. Templex PCR (tem-PCR) was applied to avoid interference between different primers in conventional multiplex-PCR. We applied this assay to 276 clinical specimens (including 27 sputum, 4 alveolar lavage fluid, 2 pleural effusion, and 243 culture isolate specimens; 40 of the 276 were non-tuberculosis mycobacteria specimens and 236 were M. tuberculosis specimens). The testing process took 4.5 h. A sensitivity of 50 copies per PCR was achieved, while the sensitivity was 500 copies per PCR when tem-PCR was used. Allele sequences could be detected in mixed samples at a proportion of 10%. Detection results showed a concordance rate of 97.46% (230/236) in rifampicin resistance detection (sensitivity 95.40%, specificity 98.66%) and 96.19% (227/236) in isoniazid (sensitivity 93.59%, specificity 97.47%) detection with those of DST assay. Concordance rates of testing results for sputum, alveolar lavage fluid, and pleural effusion specimens were 100%. The assay provides a potential choice for TB diagnosis and treatment.