• 제목/요약/키워드: Fluorescent assay

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Anticlastogenic Effect of Eryngium foetidum L. Assessed by Erythrocyte Micronucleus Assay

  • Promkum, Chadamas;Butryee, Chaniphun;Tuntipopipat, Siriporn;Kupradinun, Piengchai
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3343-3347
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    • 2012
  • The aim of this study was to investigate the anticlastogenicity as well as the clastogenicity of Eryngium foetidum leaf (EF) using the in vivo mouse peripheral blood erythrocyte micronucleus assay. Eighty ICR male mice were fed AIN-76 diet supplemented with ground freeze-dried EF at 0.0%, 0.8%, 1.6% and 3.2% for 2 weeks prior to the administration of both direct-acting, mitomycin C (MMC), and indirect-acting, 7, 12-dimethylbenz(a) anthracene (DMBA) clastogens. Peripheral blood samples were collected from mice just before administration of clastogen and at 24 and 48 h thereafter for MMC. Blood samples were collected at the same times and after 72 h for DMBA. Then, reticulocytes in blood samples were counted using fluorescent microscopy. The results indicated that EF had no clastogenic effect in mice. All doses of diets supplemented with EF decreased the number of micronucleated peripheral reticulocytes in all the MMC-treated groups in a dose dependent manner, but significant reduction was found only at 1.6% and 3.2% EF in the DMBA-treated groups. It can be concluded that EF has no clastogenicity, but possesses anticlastogenic potential against both direct- and indirect-acting types of clastogen in mice.

Liposome-Based Assay for Phospholipase C

  • 임수정;고유찬;이은옥;김종국
    • Bulletin of the Korean Chemical Society
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    • v.18 no.7
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    • pp.761-766
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    • 1997
  • Phospholipase C from Clostridium perfringens is known to catalyze the hydrolysis of phospholipids in biological membranes. In this study, a simple and sensitive method for assaying phospholipase C was developed by using liposomes entrapping calcein as a fluorescent marker. Phospholipase C-induced lysis of liposomes was determined by measuring the fluorescence intensity of calcein released out from liposomes, Various liposomes with different compositions were prepared by reverse-phase evaporation method to investigate the effect of liposomal composition on the lytic activity of phospholipase C. The calcein-entrapping efficiency of liposomes was affected by the chain length of fatty acid in phosphatidylcholine constituting liposomes. The lytic activity of phospholipase C was the highest against liposomes prepared with eggPC. The lytic activity decreased with increasing chain length of fatty acid in phosphatidylcholine. Incorporation of cholesterol more than 20% into the liposomal bilayer inhibited the phospholipase C-induced lysis. The lysis of liposomes was more greatly increased by the addition of 10 mM of calcium. The lytic activity of phospholipase C was also affected by the surface charge of liposomes. Taken together, it was concluded that reverse-phase evaporation vesicles composed of dipalmitoylphosphatidylcholine and cholesterol in the molar ratio of 9 : 1 allowed to detect the lowest concentration of phospholipase C (0.10 μg/assay volume). This study suggested that the use of liposomes can provide a simple, sensitive and inexpensive method for assaying phospholipase C.

Oral Manifestation of Paraneoplastic Pemphigus

  • Kim, Seurin;Park, In Hee;Park, YounJung;Kwon, Jeong-Seung;Choi, Jong-hoon;Ahn, Hyung-Joon
    • Journal of Oral Medicine and Pain
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    • v.44 no.3
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    • pp.118-122
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    • 2019
  • Paraneoplastic pemphigus (PNP) is a rare and often fatal autoimmune blistering disease accompanied by both benign and malignant neoplasms. Usually, oral, skin, and mucosal lesions are the earliest manifestations shown by PNP patients. Oral ulcers are initial lesions in various autoimmune diseases like pemphigus, bullous pemphigoid, erythema multiforme, graft-versus-host, lichen planus, it does not improved despite of high-dose steroid therapy. We report a-35-year-old female who presented oral ulceration, lip crust and skin lesions. By doing several examinations, such as enzyme-linked immunosorbent assay, incisional biopsy with indirect immunofluorescence, she was diagnosed PNP with non-Hodgkin's lymphoma on pancreas.

Characterization of Nitric Oxide (NO)-Induced Cell Death in Lung Epithelial Cells (폐상피세포에서 Nitric Oxide (NO)에 의한 세포사에 관한 연구)

  • Yong, Wha Shim;Kim, Youn Seup;Park, Jae Seuk;Jee, Young Koo;Lee, Kye Young
    • Tuberculosis and Respiratory Diseases
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    • v.56 no.2
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    • pp.187-197
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    • 2004
  • Background : Nitric Oxide (NO) is a multi-faceted molecule with dichotomous regulatory roles in many areas of biology. NO can promote apoptosis in some cells, whereas it inhibits apoptosis in other cell types. This study was performed to characterize NO-induced cell death in lung epithelial cells and to investigate the roles of cell death regulators including iron, bcl-2 and p53. Methods : A549 cells were used for lung epithelial cells. SNP (sodium nitroprusside) and SNAP (S-nitroso-N-acetyl- penicillamine) were used for NO donor. Cytoxicity assay was done by MTT assay and crystal violet assay. Apoptotic assay was done by fluorescent microscopy after double staining with propidium iodide and hoecst 33342. Iron inhibition study was done with RBCs and FeSO4. For bcl-2 study, bcl-2 overexpressing cells (A549-bcl-2) were used and for p53 study, Western blot analysis and p53 functionally knock-out cells (A549-E6) were used. Results : SNP and SNAP induced dose-dependent cell death in A549 cells and fluorescent microscopy revealed that SNAP induced apoptosis in low doses but necrosis in high doses while SNP induced exclusively necrotic cell death. Iron inhibition study using RBCs and FeSO4 significantly blocked SNAP-induced cell death. And also SNAP-induced cell death was blocked by bcl-2 overexpression. Finally, we found that SNAP activate p53 by Western blot analysis and that SNAP-induced cell death was decreased in the abscence of p53. Conclusion : In lung epithelial cells, NO can induce cell death, more precisely apoptosis in low doses and necrosis in high doses. And iron, bcl-2, and p53 play important roles in NO-induced cell death.

Identification of Heterodera glycines (Tylenchida; Heteroderidae) Using qPCR

  • Ko, Hyoung-Rai;Kang, Heonil;Park, Eun-Hyoung;Kim, Eun-Hwa;Lee, Jae-Kook
    • The Plant Pathology Journal
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    • v.35 no.6
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    • pp.654-661
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    • 2019
  • The soybean cyst nematode, Heterodera glycines, is a major plant-parasitic nematode that has caused important economic losses to Korea's soybean production. Four species of cyst nematodes, H. schachtii, H. glycines, H. trifolii, and H. sojae, all belong to schachtii group are coexist in field soil in Korea. The rapid identification of the nematode is crucial for preventing crop damage and in decision making for controlling this nematode. This study aimed to develop a species-specific primer set for quantitative PCR (qPCR) assay of H. glycines. The specific primer set (HGF1 and HGR1) for H. glycines was designed based on the cytochrome c oxidase subunit I (COI) sequence of mitochondrial DNA. After optimization, it is possible to identify the H. glycines using a qPCR assay with DNA extracted from a single cyst and single second-stage juvenile (J2). The specificity was confirmed by the absence of SYBR fluorescent signals of three other Heterodera species. A serial dilution of DNA extracted from a single cyst was obtained for the sensitivity test. The result showed that the standard curve of the test had a highly significant linearity between DNA concentration and Ct value (R2 = 0.996, slope = -3.49) and that the detection limit concentration of DNA of the primer set was 10 pg of DNA per reaction. Our findings suggested that H. glycines could be distinguished from H. sojae and other Heterodera species when a qPCR assay is used with a specific primer set.

Two-Cell Spheroid Angiogenesis Assay System Using Both Endothelial Colony Forming Cells and Mesenchymal Stem Cells

  • Shah, Sajita;Kang, Kyu-Tae
    • Biomolecules & Therapeutics
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    • v.26 no.5
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    • pp.474-480
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    • 2018
  • Most angiogenesis assays are performed using endothelial cells. However, blood vessels are composed of two cell types: endothelial cells and pericytes. Thus, co-culture of two vascular cells should be employed to evaluate angiogenic properties. Here, we developed an in vitro 3-dimensional angiogenesis assay system using spheroids formed by two human vascular precursors: endothelial colony forming cells (ECFCs) and mesenchymal stem cells (MSCs). ECFCs, MSCs, or ECFCs+MSCs were cultured to form spheroids. Sprout formation from each spheroid was observed for 24 h by real-time cell recorder. Sprout number and length were higher in ECFC+MSC spheroids than ECFC-only spheroids. No sprouts were observed in MSC-only spheroids. Sprout formation by ECFC spheroids was increased by treatment with vascular endothelial growth factor (VEGF) or combination of VEGF and fibroblast growth factor-2 (FGF-2). Interestingly, there was no further increase in sprout formation by ECFC+MSC spheroids in response to VEGF or VEGF+FGF-2, suggesting that MSCs stimulate sprout formation by ECFCs. Immuno-fluorescent labeling technique revealed that MSCs surrounded ECFC-mediated sprout structures. We tested vatalanib, VEGF inhibitor, using ECFC and ECFC+MSC spheroids. Vatalanib significantly inhibited sprout formation in both spheroids. Of note, the $IC_{50}$ of vatalanib in ECFC+MSC spheroids at 24 h was $4.0{\pm}0.40{\mu}M$, which are more correlated with the data of previous animal studies when compared with ECFC spheroids ($0.2{\pm}0.03{\mu}M$). These results suggest that ECFC+MSC spheroids generate physiologically relevant sprout structures composed of two types of vascular cells, and will be an effective pre-clinical in vitro assay model to evaluate pro- or anti-angiogenic property.

Multimodal Nonlinear Optical Microscopy for Simultaneous 3-D Label-Free and Immunofluorescence Imaging of Biological Samples

  • Park, Joo Hyun;Lee, Eun-Soo;Lee, Jae Yong;Lee, Eun Seong;Lee, Tae Geol;Kim, Se-Hwa;Lee, Sang-Won
    • Journal of the Optical Society of Korea
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    • v.18 no.5
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    • pp.551-557
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    • 2014
  • In this study, we demonstrated multimodal nonlinear optical (NLO) microscopy integrated simultaneously with two-photon excitation fluorescence (TPEF), second-harmonic generation (SHG), and coherent anti-Stokes Raman scattering (CARS) in order to obtain targeted cellular and label-free images in an immunofluorescence assay of the atherosclerotic aorta from apolipoprotein E-deficient mice. The multimodal NLO microscope used two laser systems: picosecond (ps) and femtosecond (fs) pulsed lasers. A pair of ps-pulsed lights served for CARS (817 nm and 1064 nm) and SHG (817 nm) images; light from the fs-pulsed laser with the center wavelength of 720 nm was incident into the sample to obtain autofluorescence and targeted molecular TPEF images for high efficiency of fluorescence intensity without cross-talk. For multicolor-targeted TPEF imaging, we stained smooth-muscle cells and macrophages with fluorescent dyes (Alexa Fluor 350 and Alexa Fluor 594) for an immunofluorescence assay. Each depth-sectioned image consisted of $512{\times}512$ pixels with a field of view of $250{\times}250{\mu}m^2$, a lateral resolution of $0.4{\mu}m$, and an axial resolution of $1.3{\mu}m$. We obtained composite multicolor images with conventional label-free NLO images and targeted TPEF images in atherosclerotic-plaque samples. Multicolor 3-D imaging of atherosclerotic-plaque structural and functional composition will be helpful for understanding the pathogenesis of cardiovascular disease.

Development of a New Approach to Determine the Potency of Bacille Calmette-Guérin Vaccines Using Flow Cytometry

  • Gweon, Eunjeong;Choi, Chanwoong;Kim, Jaeok;Kim, Byungkuk;Kang, Hyunkyung;Park, Taejun;Ban, Sangja;Bae, Minseok;Park, Sangjin;Jeong, Jayoung
    • Osong Public Health and Research Perspectives
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    • v.8 no.6
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    • pp.389-396
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    • 2017
  • Objectives: To circumvent the limitations of the current golden standard method, colony-forming unit (CFU) assay, for viability of Bacille Calmette-$Gu{\acute{e}}rin$ (BCG) vaccines, we developed a new method to rapidly and accurately determine the potency of BCG vaccines. Methods: Based on flow cytometry (FACS) and fluorescein diacetate (FDA) as the most appropriate fluorescent staining reagent, 17 lots of BCG vaccines for percutaneous administration and 5 lots of BCG vaccines for intradermal administration were analyzed in this study. The percentage of viable cells measured by flow cytometry along with the total number of organisms in BCG vaccines, as determined on a cell counter, was used to quantify the number of viable cells. Results: Pearson correlation coefficients of FACS and CFU assays for percutaneous and intradermal BCG vaccines were 0.6962 and 0.7428, respectively, indicating a high correlation. The coefficient of variation value of the FACS assay was less than 7%, which was 11 times lower than that of the CFU assay. Conclusion: This study contributes to the evaluation of new potency test method for FACS-based determination of viable cells in BCG vaccines. Accordingly, quality control of BCG vaccines can be significantly improved.

Protective effect of Caryophylli Flos on apoptosis caused by oxidative stress in HaCaT cells (HaCaT 세포의 산화 스트레스로 인한 세포자멸사에서 정향의 보호효과)

  • Park, Sook Jahr
    • The Korea Journal of Herbology
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    • v.36 no.5
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    • pp.93-99
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    • 2021
  • Objective : Caryophylli Flos has been used in Korean medicine to relieve vomiting and pains caused by chills that make fluid circulation difficult. This study was designed to investigate the protective effect of ethanol extract of Caryophylli Flos (CF) in hydrogen peroxide (H2O2)-induced apoptotic cell death in human keratinocyte HaCaT cells. Methods : CF was prepared by extracting 200 g of Caryophylli Flos in 2 L of ethanol for 48 h. Cell viability was measured by MTT assay, and the protein expression was monitored by Western blot analysis. Apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Reactive oxygen species (ROS) was measured using fluorescent dye, and reduced glutathione (GSH) was determined with a colorimetric commercial kit. Results : CF protected HaCaT cells from cell death caused by oxidative stress after H2O2 treatment. H2O2 amplified generation of ROS and induced depletion of GSH, whereas these changes in ROS and GSH were inhibited by GF treatment. In addition, H2O2 resulted in apoptosis as assessed by TUNEL assay and the expression of apoptosis regulator proteins. However, cells treated with CF showed a decrease in TUNEL-positive cells and restored the reduced expression of procaspase-9, -3 and PARP. Conclusion : This study showed cytoprotective effects of CF by anti-apoptotic activity while exerting antioxidative activity in H2O2-treated HaCaT cells. These results suggest that CF could be beneficial in skin damage caused by oxidative stress.

Suppression of Bacterial Wilt with Fuorescent Pseudomonads, TS3-7 strain (Fluorescent siderophore 생산균주, TS3-7에 의한 풋마름병 발병 억제)

  • Kim, Ji-Tae;Cho, Hong-Bum;Kim, Shin-Duk
    • Applied Biological Chemistry
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    • v.48 no.3
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    • pp.296-300
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    • 2005
  • Among the root colonizing and plant growth promoting bacteria isolated from the bacterial wilt suppressive soil, five strains were detected to produce siderophores by CAS agar assay. The most effective isolate, TS3-7 strain induced significant suppression of bacterial wilt disease in tomato and pepper plants. Seed treatment followed by soil drench application with this strain resulted in over 80% reduction of bacterial wilt disease compared with the control. Significant disease suppression by TS3-7 strain was related to the production of siderophore. Besides iron competition, induction of resistance of the host plant with siderophore was suggested to be another mode of action that suppress bacterial wilt, based on the lack of direct antibiosis against pathogen in vitro. According to Bergey's Manual of Systemic Bacteriology and 16S rDNA sequence data, TS3-7 stain was identified as Pseudomonas sp. TS3-7.