• Applied Microscopy
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• 제44권2호
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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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• 제20권2호
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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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• 제53권6호
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• pp.656-661
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• 2002

저자들은 불응성 상심실성 빈맥으로 저용량 amiodarone을 장기간 사용한 환자에서 발생한 폐독성을 경험하고 적절히 치료하였기에 이를 보고하는 바이다.

• Biomaterials and Biomechanics in Bioengineering
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• 제1권2호
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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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• 제17권sup3호
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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.

• 한국수산과학회지
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• 제49권5호
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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.

• 대한한의학방제학회지
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• 제19권2호
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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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• 제42권2호
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• pp.123-127
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• 1999

철은 사람에게 필수적인 영양소일 뿐 아니라 해로운 요소로도 작용한다. 이러한 철에 의해 진핵생물체에서 발현이 조절되는 유전자들을 밝히기 위해 철이 첨가되거나, 제거된 조건에서 배양된 HeLa세포로부터 RNA differential display 방법을 이용하여 발현 또는 억제되는 유전자들을 선별하였다. 모두 24개의 유전자가 선별되었으며, 염기배열 확인과 northern blot의 발현 확인과정을 거쳐 4개의 유전자들이 철에 의해 영향을 받는 것으로 확인되었다.

• Journal of Microbiology and Biotechnology
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• 제28권8호
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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.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.978-983
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• 2017

ADN은 환경적인 그리고 독성적인 측면에서 ammonium prochlorate를 대체하는 현재 연구중인 물질이다. 고독성의 발암물질인 하이드라진을 대체할 수 있는 액체 추진제에 적용되기도 한다. ADN의 합성은 현재 GUDN(Guanylurea dinitramide)과 potassium hydroxide를 통해 potassium dinitramide(KDN)얻을 수 있다. 두 번째 반응 단계는 KDN과 ammonium sulfate를 반응하여 ADN을 얻어진다. 우리의 새로 개선된 공정은 GUDN으로부터 한단계로 ADN을 합성하는 것이다. 부산물의 양을 줄이고 잠재적으로 낮은 단가의 ADN 제조되는 순도가 개선된 간단한 공정은 ADN 사용을 지지하기 위해 결정적이다.