• Applied Microscopy
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• v.44 no.2
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• pp.68-73
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• 2014

With wide use of nano-materials, it is increasingly important to address their potential toxicity to mammalian cells. However, toxic effects of these materials have been mainly assessed by the cell survival assays. Considering that mitochondrial morphology and quality are highly sensitive to the condition of the cells, and the impairment of mitochondrial function greatly affect the survival of cells, here we tested the impact of multi-walled carbon nanotubes (MWNT) on the survival, mitochondrial morphology, and their membrane potential in HeLa cells. Interestingly, although MWNT did not induce cell death until 24 hours as assessed by pyknotic cell assay, mitochondrial length was elongated and the mitochondrial membrane potential was significantly reduced by exposure of HeLa cells to MWNT. These results suggest that MWNT exposure is potentially harmful to the cell, and the mechanism how MWNT alters mitochondrial quality should be further explored to assess the safety of MWNT use.

• ALGAE
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• v.20 no.2
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• pp.157-166
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• 2005

Uptake kinetics of Cd and Zn by leaves and rhizome of the seagrass Zostera marina were examined in controlled laboratory radiotracer experiments. Subsequently, acute toxicity of Cd, Cu and TBT on photosynthetic quantum yield (ΔF/Fm’ of Z. marina were determined, and the differential sensitivities of rapid light curve (RLC) to those harmful substances were also compared. All measurements on photosynthetic activity were determined by chlorophyll a fluorescence method using pulse amplitude modulation (PAM). Metal uptake by Z. marina was saturated with increasing exposure time in leaves and rhizomes. Uptake of Zn by Z. marina was faster than that of Cd. Metal uptake rates in Z. marina decreased with the increase of dissolved metal concentrations and also with the increase of biomass. The adverse effect of TBT on effective quantum yield was stronger than other pollutants. Average acute toxicity on the RLC of the seagrass exposed to TBT and two heavy metals (Cd and Cu) was going to decrease as follows: TBT > Cd > Cu. Our preliminary results in this study suggested that Z. marina potentially can be used as a biomonitor of harmful substances contamination in coastal waters.

• Tuberculosis and Respiratory Diseases
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• v.53 no.6
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• pp.656-661
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• 2002

Amidarone is one of the most commonly prescribed anti-arrythmic agents for almost all arrythmias, whether atrial or ventricular in origin. There are several side effects associated with amiodarone therapy. These include corneal deposits, abnormal liver function tests, hyper and hypothyroidism, bluish discolorations of the skin, bone marrow suppression, coagulopathies, peripheral neuropathies, and pulmonary toxicity. Amiodarone-induced pulmonary toxicity(APT), which was first described in 1980, is potentially serious side effects that are believed to develop in 5% of patients. Doctors often assume that APT occurs only when high amiodarone doses are used for a long time, but in practice a low maintenance dose of amiodarone may also be toxic. In this report, a case of amiodarone-induced pulmonary toxicity after a long course of a low dose therapy for refractory supraventricular arrythmia is described.

• Biomaterials and Biomechanics in Bioengineering
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• v.1 no.2
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• pp.63-71
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• 2014

This study aimed to develop a novel bioactive hybrid xerogel consisting of silk fibroin /$SiO_2-CaO-P_2O_5$ by sol-gel process at room temperature. Scanning electron microscopy (SEM), FT-IR Spectroscopy, pore measurement, mechanical property testing, in vitro bioactivity test and cytotoxicity assay were performed to characterize the xerogel for bone tissue engineering application. We have found that the xerogel possessed excellent pore structures and mechanical property. Once immersed in a simulated fluid (SBF), the xerogel exhibited profound bioactivity by inducing hydroxyapatite layers on its surfaces. The cell toxicity study also demonstrated that there was little toxic to MC3T3-E1 cells. These results indicate that silk fibroin /$SiO_2-CaO-P_2O_5$ hybrid xerogel potentially could be used as a bone tissue engineering material.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.299-304
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• 2016

Cytolethal distending toxin (CDT) is a secreted tripartite genotoxin produced by many pathogenic gram-negative bacteria. It is composed of three subunits, CdtA, CdtB and CdtC, and CdtB-associated deoxyribonuclease (DNase) activity is essential for the CDT toxicity. In the present study, to design a novel potentially antitumor drug against lung cancer, the possible mechanisms of cdtB anticancer properties were explored in the A549 human lung adenocarcinoma cell line. A recombinant plasmid pcDNA3.1/cdtB was constructed expressing CdtB of human periodontal bacterium Aggregatibacter actinomycetemcomitans and investigated for toxic properties in A549 cells and possible mechanisms. It was observed that plasmid pcDNA3.1/cdtB caused loss of cell viability, morphologic changes and induction of apoptosis. Furthermore, measurement of caspase activity indicated involvement of an intrinsic pathway of cell apoptosis. Consequently, the recombinant plasmid pcDNA3.1/cdtB may have potential as a new class of therapeutic agent for gene therapy of lung cancer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.594-599
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• 2016

Infection with HIV (Human immunodeficiency virus), over time, develops into acquired immunodeficiency syndrome (AIDS). The development of non-toxic and effective anti-HIV drugs is one of the most promising strategies for the treatment of AIDS. In this study, we investigated the anti-HIV-1 activity of gelatin hydrolysates from Alaska pollack skin. Gelatin hydrolysates were prepared using four enzymes (alcalase, flavourzyme, neutrase, and pronase E). Among these, the pronase E gelatin hydrolysate was found to inhibit HIV-1 infection in the human T cell-line MT4. It exhibited inhibitory activity on HIV-1_IIIB-induced cell lysis, reverse transcriptase activity, and viral p24 production at noncytotoxic concentrations. Moreover, it decreased the activation of matrix metalloproteinase-2 (MMP-2) in vitro. Because HIV infection-induced activation of MMP-2 can accelerate collagen resolution and collapse of the immune system, pronase E gelatin hydrolysate might prevent the activation of MMP-2 in cells, resulting in collagen stabilization and immune cell homeostasis consistent with anti-HIV activation. These results suggest that pronase E gelatin hydrolysate could potentially be incorporated into a novel therapeutic agent for HIV/AIDS patients.

• Herbal Formula Science
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• v.19 no.2
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• pp.93-108
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• 2011

Objectives : Angelica sinensis has been used extensively in Korean traditional medicine. Although thorough clinical trials are lacking, Various pharmacological actions for Angelica sinensis has been identified newly using animal models. In addition, it was reported that reactive intermediates, potentially causing toxic effects, was isolated from components in Angelica sinensis. In this article, it was purposed for explanation and introduction of new studies for Angelica sinensis. in terms of Pharmacological action and Toxicity. Methods : New studies for Angelica sinensis were reviewed and summarized in terms of pharmacological action and toxicity. Results and Conclusions : Angelica sinensis and its components including phthalide, phthalide dimers, polysaccharides, polyacetylenes, ligustilide와 butylidenephthalide as well as organic acid showed a variety of pharmacological actions on uterine, cardiovascular system and immune system. In addition, it was identified that three components of such as ligustilide, caffeic acid and safrole was biotransformed to reactive intermediates causing possibly toxicity.

• Applied Biological Chemistry
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• v.42 no.2
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• pp.123-127
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• 1999

Iron is an essential nutrient but potentially toxic element in human. To identify the effects of iron on the gene expression of mammalian cell, we have isolated several genes that are regulated by iron using the RNA differential display method. RNAs were isolated from HeLa cells treated with iron supplement or iron chelator. A total of 24 genes were isolated and of these, four genes were identified by DNA sequencing and northern blot.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1299-1309
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• 2018

We previously reported on lactophoricin (LPcin), a cationic ${\alpha}-helical$ antimicrobial peptide derived from bovine milk, which has antimicrobial effects on Candida albicans as well as Gram-positive and Gram-negative bacteria. In this study, we designed the LPcin-YK3 peptide, a shorter analog of LPcin, and investigated its antimicrobial activity. This peptide, consisting of 15 amino acids with + 3 net charges, was an effective antimicrobial agent against the on the Gram-positive strain, Staphylococcus aureus (MIC: $0.62{\mu}g/ml$). In addition, the hemolytic activity assay revealed that the peptide was not toxic to mouse and human erythrocytes up to $40{\mu}g/ml$. We also used circular dichroism spectroscopy to confirm that peptide in the presence of lipid has ${\alpha}-helical$ structures and later provide an overview of the relationship between each structure and antimicrobial activity. This peptide is a member of a new class of antimicrobial agents that could potentially overcome the problem of bacterial resistance caused by overuse of conventional antibiotics. Therefore, it could be used as a therapeutic or natural additive, particularly in the cosmetics industry.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.978-983
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• 2017

Ammonium dinitramide(ADN) is currently under inder investigation as a replacement for ammonium perchlorate, both for environmental and toxicological reasons. Another promising application is ADN-based liquid monopropellant as a replacement for hydarzine, which is highly toxic and carcinogenic. Production of ADN is today normally performed via guanylurea dinitramide(GUDN) by reaction with potassium hydroxide to yiela potassium dinitramide(KDN). In a second reaction step, KDN is reacted with ammonium sulfate to give ADN. In our new improved process, ADN is synthesized from GUDN in one single reaction step. The simplified process improves purity, reduces the amount of by-products and allows production of ADN at a potentially lower cost, which is crucial to favour the use of ADN.