• 제목/요약/키워드: Membrane resistance

검색결과 859건 처리시간 0.032초

대황견우산(大黃牽牛散) 에탄올 추출물의 Methicillin 내성 Staphylococcus aureus에 대한 항균활성 연구 (A Study on Antibacterial Activity of Daehwanggeonwoo-san(Dahwangqianniu-san) Ethanol Extract against Methicillin-Resistant Staphylococcus Aureus)

  • 박주영;나용수;오공천;이상미;최병권;이윤승;송용선
    • 한방재활의학과학회지
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    • 제28권2호
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    • pp.21-35
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    • 2018
  • Objectives The objective of this study is to determine the antimicrobial effect of Daehwanggyeonu-san(Dahwangqianniu-san,DGE) and synergistic effects with antibiotics oxacillin, ampicillin, and gentamicin against Methicillin-Resistant Staphylococcus aureus(MRSA). Methods The antibacterial activity of DGE extract was evaluated againest MRSA strains by using the Disc diffusion method, broth microdilution method(minimal inhibitory concentration; MIC), checkerboard dilution test. The checkerboard dilution test was used to examined synergetic effect of oxacillin, ampicillin, gentamicin, ciprofloxacin with DGE extract. Results DGE showed antimicrobial activity against MRSA with an MIC value of $125{\sim}250{\mu}g/mL$. In the checkerboard test, the interation of DGE with all tested antibiotics produced almost synergy or partial synergy against MRSA. Conclusions This study shows that DGE reduced the MICs of several antibiotics tested, and a remarkable antibacterial effect of DGE, with membrane permeability enhancers and ATP synthase inhibitors. This study can be a valuable source for the development of a new drug with low MRSA resistance.

약물의 in vitro 투과 실험을 위한 사람의 비강점막상피세포 단층막의 일차배양 (Primary Culture of Human Nasal Epithelial Cell Monolayer for In Vitro Drug Transport Studies)

  • 유진욱;김유선;이민기;노환중;이치호;김대덕
    • Journal of Pharmaceutical Investigation
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    • 제32권1호
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    • pp.21-26
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    • 2002
  • The primary culture of human nasal epithelial cell monolayer was performed on a Transwell. The effect of various factors on the tight junction formation was observed in order to develop an in vitro experimental system for nasal transport studies. Human nasal epithelial cells, collected from human normal inferior turbinates, were plated onto diverse inserts. After 4 days, media of the apical surface was removed for air-liquid interface (ALI) culture. Morphological characteristics was observed by transmission electron microscopy (TEM). A polyester membrane of $0.4\;{\mu}m$ pore size was determined as the most effective insert based on the change in the transepithelial electric resistance (TEER) value as well as the $^{14}C-mannitol$ transport study. The ALI method was effective in developing the tight junction as observed in the further increase in the TEER value and reduction in the permeability coefficient $(P_{app})$ of $^{14}C-mannitol$ transport. Results of the transport study of a model drug, budesonide, showed that the primary culture system developed in this study could be further developed and applied for in vitro nasal transport studies.

Effects of Discontinuous Percoll Gradient Containing Alpha-linolenic Acid on Characteristics of Frozen-thawed Boar Spermatozoa

  • Kim, Doo-San;Hwangbo, Yong;Cheong, Hee-Tae;Park, Choon-Keun
    • 한국동물생명공학회지
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    • 제35권1호
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    • pp.58-64
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    • 2020
  • This present study was conducted to investigate protective effect of discontinuous Percoll gradient containing alpha-linolenic acid (ALA) before freezing process on viability, acrosome damage, mitochondrial activity, and oxidative stress of frozen-thawed boar spermatozoa. The separation of spermatozoa by discontinuous Percoll gradient was performed by different concentration of Percoll solution (45/90%) containing ALA combined with bovine serum albumin (BSA), and collected sperm in each Percoll layer was cryopreserved. To evaluate viability, acrosome damage, mitochondrial activity, and reactive oxygen species (ROS) level of frozen-thawed sperm, flow cytometry was used. Morphological abnormalities were observed under light microscope. In results, viability of sperm from 90% Percoll layer was higher than control and 45% Percoll group (p < 0.05). Separated sperm in 90% Percoll layer had lower acrosome damage and morphological abnormalities than control as well as viability, whereas 45% Percoll group was higher (p < 0.05). Similar with acrosome damage and abnormalities, mitochondrial activity was slightly enhanced and the population of live sperm with high ROS level was decreased by 90% Percoll separation, however, there was no significant difference. Supplementation of 3 ng/mL ALA into Percoll solution increased sperm viability and decreased population of live sperm with high ROS compared to control (p < 0.05). In conclusion, discontinuous Percoll gradient before freezing process could improve efficiency of cryopreservation of boar sperm through selection of sperm with high freezing resistance, and supplement of ALA during Percoll gradient might contribute suppression of ROS generation via stabilizing of plasma membrane during cryopreservation.

간기능 개선용 복합 식물 추출물(Hepa-1000)의 tert-butyl hydroperoxide(t-BHP)로 유도한 간세포 독성에 대한 보호 효과 (Hepatoprotective Effects of Poly Herbal Formulation (Hepa-1000) on t-BHP Induced Toxicity in Human Hepatoma Cells)

  • 이유진;김경범;정종문
    • 한국식품영양과학회지
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    • 제35권9호
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    • pp.1121-1126
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    • 2006
  • In the present study, the potential hepatoprotective effects of poly herbal formulation, Hepa-1000, against oxidative damages induced by t-BHP were evaluated in HepG2 cells in order to relate in vitro antioxidant activity with cytoprotective effects. The t-BHP induced considerable cell damage in HepG2 cells was shown by significant glutamic oxaloacetic transaminase (GOT) and lactate dehydrogenase (LDH) leakage, and increased lipid peroxidation. Hepa-1000-treated cells showed an increased resistance to oxidative challenge, as revealed by higher survival capacity than the one of control cells against t-BHP induced oxidative stress and hepatotoxicity. In addition, the Hepa-1000 had hepatoprotective effects lowering the activity of GOT and LDH, simultaneously. That is, it could inhibit the cell membrane damages resulting in the increased activities of GOT and LDH in the cell culture media. Furthermore, the Hepa-1000 could reduce t-BHP enhanced lipid peroxidation, which was evaluated by measuring the production of malonedialdehyde. Based on the data described above, it could be suggested that the Hepa-1000 has significant hepatoprotective effects and plays a protective role against lipid peroxidation by free radicals.

백출 및 발효백출의 장점막 투과성 개선 효과 및 항염증효과 (Effect of Unfermented and Fermented Atractylodes macrocephalae on Gut Permeability and Lipopolysaccharide-Induced Inflammation)

  • 한경선;김기철;왕경화;김호준
    • 한방비만학회지
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    • 제13권1호
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    • pp.24-32
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    • 2013
  • Objectives: The aim of this study is to investigate anti-imflammatory and protective effect for intestinal epithelial cells with Atractylodes macrocephae (AM), a traditional Korean Herbal medicine and fermented Atractylodes macrocephae (FAM) with Lactobacillus plantarum. Methods: HCT-116 and Raw 264.7 cells were used in this study. Using NO assay, we measured lipopolysaccharide (LPS)-induced anti-inflammatory effect. We measured permeability of intestinal epithelial cells with transepithelial electrical resistance and horseradish peroxide flux assay. Water soluble tetrazolium salt assay was used to see cell proliferation. All the results were presented in mean and standard deviation. We used Student's t-test for analyzing significance of results. Results: In Raw 264.7 cells NO production decreased 22.4% with pre-treatment of AM and FAM, especially with FAM in high concentration. In HCT-116 cells LPS-induced intestinal permeability had a protective effect with both AM and FAM, which was also tend to be proportional to the concentration. Cell viability increased up to 135.52% after treatment of high concentration of FAM in HCT-116, while there was no significant change in Raw 264.7 cells with herb treatments. Conclusions: These results show evidence that AM, especially fermented ones, significantly reduced intestinal membrane permeability. They also had a protective effect as well as an anti-inflammation effect for HCT-116 and Raw 264.7 cells. This suggest that FAM may be a therapeutic agent for Leaky gut syndrome by reducing intestinal permeability.

Developing a Virus-Binding Bacterium Expressing Mx Protein on the Bacterial Surface to Prevent Grouper Nervous Necrosis Virus Infection

  • Lin, Chia-Hua;Chen, Jun-Jie;Cheng, Chiu-Min
    • Journal of Microbiology and Biotechnology
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    • 제31권8호
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    • pp.1088-1097
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    • 2021
  • Grouper nervous necrosis virus (GNNV) infection causes mass grouper mortality, leading to substantial economic loss in Taiwan. Traditional methods of controlling GNNV infections involve the challenge of controlling disinfectant doses; low doses are ineffective, whereas high doses may cause environmental damage. Identifying potential methods to safely control GNNV infection to prevent viral outbreaks is essential. We engineered a virus-binding bacterium expressing a myxovirus resistance (Mx) protein on its surface for GNNV removal from phosphate-buffered saline (PBS), thus increasing the survival of grouper fin (GF-1) cells. We fused the grouper Mx protein (which recognizes and binds to the coat protein of GNNV) to the C-terminus of outer membrane lipoprotein A (lpp-Mx) and to the N-terminus of a bacterial autotransporter adhesin (Mx-AIDA); these constructs were expressed on the surfaces of Escherichia coli BL21 (BL21/lpp-Mx and BL21/Mx-AIDA). We examined bacterial surface expression capacity and GNNV binding activity through enzyme-linked immunosorbent assay; we also evaluated the GNNV removal efficacy of the bacteria and viral cytotoxicity after bacterial adsorption treatment. Although both constructs were successfully expressed, only BL21/lpp-Mx exhibited GNNV binding activity; BL21/lpp-Mx cells removed GNNV and protected GF-1 cells from GNNV infection more efficiently. Moreover, salinity affected the GNNV removal efficacy of BL21/lpp-Mx. Thus, our GNNV-binding bacterium is an efficient microparticle for removing GNNV from 10‰ brackish water and for preventing GNNV infection in groupers.

Expression and Purification of Transmembrane Protein MerE from Mercury-Resistant Bacillus cereus

  • Amin, Aatif;Sarwar, Arslan;Saleem, Mushtaq A.;Latif, Zakia;Opella, Stanley J.
    • Journal of Microbiology and Biotechnology
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    • 제29권2호
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    • pp.274-282
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    • 2019
  • Mercury-resistant ($Hg^R$) bacteria were isolated from heavy metal polluted wastewater and soil collected near to tanneries of district Kasur, Pakistan. Bacterial isolates AZ-1, AZ-2 and AZ-3 showed resistance up to $40{\mu}g/ml$ against mercuric chloride ($HgCl_2$). 16S rDNA ribotyping and phylogenetic analysis were performed for the characterization of selected isolates as Bacillus sp. AZ-1 (KT270477), Bacillus cereus AZ-2 (KT270478) and Bacillus cereus AZ-3 (KT270479). Phylogenetic relationship on the basis of merA nucleotide sequence confirmed 51-100% homology with the corresponding region of the merA gene of already reported mercury-resistant Gram-positive bacteria. The merE gene involved in the transportation of elemental mercury ($Hg^0$) via cell membrane was cloned for the first time into pHLV vector and transformed in overexpressed C43(DE3) E. coli cells. The recombinant plasmid (pHLMerE) was expressed and the native MerE protein was obtained after thrombin cleavage by size exclusion chromatography (SEC). The purification of fusion/recombinant and native protein MerE by Ni-NTA column, dialysis and fast protein liquid chromatography (FPLC/SEC) involved unfolding/refolding techniques. A small-scale reservoir of wastewater containing $30{\mu}g/ml$ of $HgCl_2$ was designed to check the detoxification ability of selected strains. It resulted in 83% detoxification of mercury by B. cereus AZ-2 and B. cereus AZ-3, and 76% detoxification by Bacillus sp. AZ-1 respectively (p < 0.05).

축전식 탈염 시스템에서 전하량 제어를 통한 경도물질의 안정적인 탈염 (Stable Desalination of Hardness Substances through Charge Control in a Capacitive Deionization System)

  • 김윤태;최재환
    • 공업화학
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    • 제30권4호
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    • pp.472-478
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    • 2019
  • 막 축전식 탈염(MCDI) 셀에 공급하는 총 전하(TC)를 조절하여 경도물질($Ca^{2+}$)을 안정하게 탈염할 수 있는 방법을 연구하였다. 흡착과정에서 TC를 변화시키면서 흡착(1.5 V)과 탈착(0.0 V)을 30회 반복하였다. 탈염과정에서 유출수의 농도와 pH, 흡착 및 탈착량, 전류밀도와 셀 전위의 변화를 분석하였다. MCDI 셀에 사용된 탄소전극의 최대허용전하(MAC)는 46 C/g로 측정되었다. MAC 이하의 TC (40 C/g)에서 운전한 결과 전극반응이 일어나지 않아 장기간 운전에서도 안정적인 탈염특성을 얻을 수 있었다. 반면, MAC 이상의 TC (50, 60 C/g)에서 운전한 경우 유출수의 농도와 pH가 크게 변하였다. 또한 전극반응으로 인해 전극표면에 스케일이 생성되어 셀의 전기저항이 점차 증가하였다. 이를 통해 흡착과정에서 MCDI 셀에 공급하는 전하를 제어함으로써 전극반응 없이 경도물질을 안정하게 제거할 수 있음을 확인하였다.

고분자 전해질 연료전지 스택용 고무 개스킷의 노화특성 연구 (Aging Property Studies on Rubber Gasket for Polymer Electrolyte Membrane Fuel Cell Stack)

  • 강동국;허병기;이동원;서관호
    • 공업화학
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    • 제22권2호
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    • pp.149-154
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    • 2011
  • 연료전지 스택 작동환경에서의 열노화 특성을 살펴보기 위하여 다양한 고무 compound의 내열 및 압축 영구 줄음률의 평가를 실시하고, 스택의 장시간 운전을 통해 접합할 수 있는 대상액인 $H_2SO_4$, $H_2O$, LLC (Ethylene glycol : $H_2O=50:50$)에 대하여 장시간 평가를 실시하였다. NBR과 EPDM은 시간이 경과할수록 침적액의 변색하는 것을 알 수 있었으며, VMQ는 $H_2SO_4$ 분위기에서 시간에 따라 고무가 노화되는 것을 TGA, SEM, EDS 분석을 통하여 확인하였다.

Inhibition of mitoNEET induces Pink1-Parkin-mediated mitophagy

  • Lee, Seunghee;Lee, Sangguk;Lee, Seon-Jin;Chung, Su Wol
    • BMB Reports
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    • 제55권7호
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    • pp.354-359
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    • 2022
  • MitoNEET, a mitochondrial outer membrane protein containing the Asn-Glu-Glu-Thr (NEET) sequence, controls the formation of intermitochondrial junctions and confers autophagy resistance. Moreover, mitoNEET as a mitochondrial substrate undergoes ubiquitination by activated Parkin during the initiation of mitophagy. Therefore, mitoNEET is linked to the regulation of autophagy and mitophagy. Mitophagy is the selective removal of the damaged or unnecessary mitochondria, which is crucial to sustaining mitochondrial quality control. In numerous human diseases, the accumulation of damaged mitochondria by impaired mitophagy has been observed. However, the therapeutic strategy targeting of mitoNEET as a mitophagy-enhancing mediator requires further research. Herein, we confirmed that mitophagy is indeed activated by mitoNEET inhibition. CCCP (carbonyl cyanide m-chlorophenyl hydrazone), which leads to mitochondrial depolarization, induces mitochondrial dysfunction and superoxide production. This, in turn, contributes to the induction of mitophagy; mitoNEET protein levels were initially increased before an increase in LC3-II protein following CCCP treatment. Pharmacological inhibition of mitoNEET using mitoNEET Ligand-1 (NL-1) promoted accumulation of Pink1 and Parkin, which are mitophagy-associated proteins, and activation of mitochondria-lysosome crosstalk, in comparison to CCCP alone. Inhibition of mitoNEET using NL-1, or mitoNEET shRNA transfected into RAW264.7 cells, abrogated CCCP-induced ROS and mitochondrial cell death; additionally, it activated the expression of PGC-1α and SOD2, regulators of oxidative metabolism. In particular, the increase in PGC-1α, which is a major regulator of mitochondrial biogenesis, promotes mitochondrial quality control. These results indicated that mitoNEET is a potential therapeutic target in numerous human diseases to enhance mitophagy and protect cells by maintaining a network of healthy mitochondria.