• Title/Summary/Keyword: fluorescence values

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A rare ginsenoside compound K (CK) induces apoptosis for breast cancer cells

  • Seun Eui Kim;Myoung-Hoon Lee;Hye-Myoung Jang;Wan-Taek Im;Joontaik Lee;Sang-Hwan Kim;Gwang Joo Jeon
    • Journal of Animal Reproduction and Biotechnology
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    • v.38 no.3
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    • pp.167-176
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    • 2023
  • Background: A breast cancer is the second leading cause of cancer death in women worldwide and among different types of breast cancers, triple-negative breast cancer (TNBC) has a poor prognosis. Methods: We investigated the potential of ginsenoside compound K (CK), an active ingredient in the bio-transformed ginsenoside, to be used as a therapeutic ingredient by examining the effects of CK on cell proliferation, apoptosis, and cancer-related gene expressions in breast cancer cells. Results: From the results of treating MCF-7, an ER and PR-positive breast cancer cells, and MDA-MB-231 (TNBC) with CK at a concentration of 0-100 µM, the half maximal inhibitory concentration (IC50) values for each cell were 52.17 µM and 29.88 µM, respectively. And also, it was confirmed that cell migration was inhibited above the IC50 concentration. In addition, fluorescence analysis of Apoptosis/Necrosis showed that CK induced apoptosis rather than necrosis of breast cancer cells. Through qPCR, it was confirmed that the expression of genes related to apoptosis and cell cycle arrest was increased in CK-treated breast cancer cells, and it acted more effectively on TNBC. However, the expression of genes related to tumor invasion and metastasis is also increased, so it is necessary to consider the timing of application of CK as a potential therapeutic anticancer compound. Conclusions: CK showed a stronger inhibitory effect in TNBC with poor prognosis but considering the high tumor invasion and metastasis-related gene expression, the timing of application of CK should be considered.

Understanding a Core Pilin of the Type IVa Pili of Acidithiobacillus thiooxidans, PilV

  • Araceli Hernandez-Sanchez;Edgar D. Paez-Perez;Elvia Alfaro-Saldana;Vanesa Olivares-Illana;J. Viridiana Garcia-Meza
    • Journal of Microbiology and Biotechnology
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    • v.34 no.3
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    • pp.525-537
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    • 2024
  • Pilins are protein subunits of pili. The pilins of type IV pili (T4P) in pathogenic bacteria are well characterized, but anything is known about the T4P proteins in acidophilic chemolithoautotrophic microorganisms such as the genus Acidithiobacillus. The interest in T4P of A. thiooxidans is because of their possible role in cell recruitment and bacterial aggregation on the surface of minerals during biooxidation of sulfide minerals. In this study we present a successful ad hoc methodology for the heterologous expression and purification of extracellular proteins such as the minor pilin PilV of the T4P of A. thiooxidans, a pilin exposed to extreme conditions of acidity and high oxidation-reduction potentials, and that interact with metal sulfides in an environment rich in dissolved minerals. Once obtained, the model structure of A. thiooxidans PilV revealed the core basic architecture of T4P pilins. Because of the acidophilic condition, we carried out in silico characterization of the protonation status of acidic and basic residues of PilV in order to calculate the ionization state at specific pH values and evaluated their pH stability. Further biophysical characterization was done using UV-visible and fluorescence spectroscopy and the results showed that PilV remains soluble and stable even after exposure to significant changes of pH. PilV has a unique amino acid composition that exhibits acid stability, with significant biotechnology implications such as biooxidation of sulfide minerals. The biophysics profiles of PilV open new paradigms about resilient proteins and stimulate the study of other pilins from extremophiles.

Improving Growth and Yield in Cherry Tomato by Using Rootstocks (대목 종류에 따른 방울토마토 생장과 수량 증가)

  • Lee, Hyewon;Lee, Jun Gu;Hong, Kue Hyon;Kwon, Deok Ho;Cho, Myeong Cheoul;Hwang, Indeok;Ahn, Yul Kyun
    • Journal of Bio-Environment Control
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    • v.30 no.3
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    • pp.196-205
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    • 2021
  • This research was conducted in order to analyze the difference in yield through the changes in growth and measuring the photosynthesis efficiency in cherry tomatoes. Seedlings of cherry tomato 'Nonari' were used as scion and non-grafted control, while 4 different grafted tomatoes 'Powerguard', 'T1', 'L1', and 'B.blocking' were used as rootstocks. Plants grafted onto 'B.blocking' produced the highest fruit yield (417.5 g plant-1), whereas non-grafted plant 'Nonari' had the lowest fruit yield, (354.2 g plant-1) at the latter period of cherry tomatoes in May. The flowering position in May, plant grafted onto 'B.blocking', showed 14-17 cm, whereas non-grafted plant 'Nonari' showed 10-14 cm. The growth strength on May 15, non-grafted plant 'Nonari', showed 8.43 mm which was the lowest value among the treatments. Grafted plants kept the growth balance until the end of the harvest that led to an increase in fruit yield, while non-grafted plant weakened the vigor earlier that led to a decrease in fruit yield. Grafted plants showed higher values of chlorophyll fluorescence variables than the values of non-grafted plant. These results indicate that grafting influenced fruit yield which was observed as maintaining growth balance for longer and an increase in photosynthesis efficiency compared to non-grafting.

Optimization of Growth Environment in the Enclosed Plant Production System Using Photosynthesis Efficiency Model (광합성효율 모델을 이용한 밀폐형 식물 생산시스템의 재배환경 최적화)

  • Kim Keesung;Kim Moon Ki;Nam Sang Woon
    • Journal of Bio-Environment Control
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    • v.13 no.4
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    • pp.209-216
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    • 2004
  • This study was aimed to assess the effects of microclimate factors on lettuce chlorophyll fluorescent responses and to develop an environment control system for plant growth by adopting a simple genetic algorithm. The photosynthetic responses measurements were repeated by changing one factor among six climatic factors at a time. The maximum Fv'/Fm' resulted when the ambient temperature was $21^{\circ}C,\;CO_2$ concentration range of 1,200 to 1,400 ppm, relative humidity of $68\%$, air current speed of $1.4m{\cdot}s^{-1}$, and the temperature of nutrient solution of $20^{\circ}C$. In PPF greater than $140{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, Fv'/Fm' values were decreased. To estimate the effects of combined microclimate factors on plant growth, a photosynthesis efficiency model was developed using principle component analysis for six microclimate factors. Predicted Fv'/Fm' values showed a good agreement to measured ones with an average error of $2.5\%$. In this study, a simple genetic algorithm was applied to the photosynthesis efficiency model for optimal environmental condition for lettuce growth. Air emperature of $22^{\circ}C$, root zone temperature of $19^{\circ}C,\;CO_2$ concentration of 1,400 ppm, air current speed of $1.0m{\cdot}s^{-1}$, PPF of $430{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and relative humidity of $65\%$ were obtained. It is feasible to control plant environment optimally in response to microclimate changes by using photosynthesis efficiency model combined with genetic algorithm.

Evaluation of Antioxidant Activity of Sugar Alcohols Using TOSC (Total Oxy-radical Scavenging Capacity) Assay (TOSC 법을 이용한 당알코올의 항산화 활성 평가)

  • Kang, Keon-Wook;Kwak, Sang-Hoon;Yun, Sei-Young;Kim, Sang-Kyum
    • Toxicological Research
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    • v.23 no.2
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    • pp.143-150
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    • 2007
  • Although animal and epidemiological studies have suggested oxidative stress as an etiological factor in pathogenesis including cancer, inflammation, sepsis, fibrosis, cardiovascularlneurodegenerative diseases and aging-related disorders, conflicting results have been obtained in clinical trial with antioxidants. The reason for this discrepancy remains unknown but may be due, in part, to the lack of a validated assay system for evaluating antioxidant capacity. The antioxidant activity of a series of sugar alcohols against peroxyl radicals, hydroxyl radicals and peroxynitrites was determined by the total oxy-radical scavenging capacity (TOSC) assay and cell-based assay using H4IIE cells. Specific TOSC values calculated from the slope of the linear regression for erythritol, xylitol, sorbitol or mannitol against peroxyl radicals was $2.1{\pm}0.2,\;3.7{\pm}0.3,\;9.1{\pm}0.3$ or $8.7{\pm}1.1$ TOSC/mM, respectively. Specific TOSC values for erythritol, xylitol, sorbitol or mannitol against peroxynitrite was $1.9{\pm}0.3,\;3.9{\pm}0.4,\;7.8{\pm}0.7$ or $7.7{\pm}0.5$ TOSC/mM, respectively. These results suggest that oxy-radical scavenging capacity is dependent on the number of aliphatic hydroxyl group in sugar alcohols of monosaccharide. Tert-butylhydroperoxide (t-BHP)-induced cell toxicity determined by MTT assay was marginally attenuated by 10 mM erythritol, but completely inhibited by 10 mM xylitol, 2 mM sorbitol or 0.75 mM maltitol, a disaccharide alcohol. Oxidative stress markers, such as glutathione (GSH) and malondial-dehyde (MDA) levels, were measured in t-BHP-treated cells using HPLC equipped with a fluorescence detector and a reverse phase column. Erythritol did not change the levels of GSH and MDA in H411E cells treated with t-BHP. The t-BHP-induced changes in cellular GSH and MDA levels were ameliorated by 10 mM xylitol and completely blocked by 10 mM sorbitol and maltitol. These results indicate that sugar alcohols protect cells against oxidative stress via scavenging oxy-radical and suggest that TOSC assay in conjunction with cell-based assay is a valid method for evaluating antioxidant capacity of natural and synthetic chemicals.

Determination of Microviscosity and Location of 1,3-Di(1-pyrenyl) propane in Brain Membranes

  • Kang, Jung-Sook;Kang, In-Goo;Yun, Il
    • Archives of Pharmacal Research
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    • v.20 no.1
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    • pp.1-6
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    • 1997
  • We determined the microviscosity of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex and liposomes of total lipids (SPMTL) and phospholipids (SPMPL) extracted from SPMV. Changes in the microviscosity induced by the range and rate of lateral diffusion were measured by the intramolecular excimerization of 1, 3-di(1-pyrenyl)propane (Py-3-Py). The microviscosity values of the direct probe environment in SPMV, SPMTL and SPMPL were 38.17, 31.11 and 27.64 cP, respectively, at$37^{\circ}C$and the activation energies $(E_a)$ of the excimer formation of Py-3-Py in SPMV, SPMTL and SPMPL were 8.236, 7.448 amd 7.025 kcal/mol, respectively. Probe location was measured by polarity and polarizability parameters of the probe Py-3-Py and probe analogues, pyrene, 1-pyrenenonanol and 1-pyrenemethyl-3${\beta}$-hydroxy-22, 23-bisnor-5-cholenate (PMC), incorporated into membranes or solubilized in reference solvents. There existed a good linear relationship between the first absorption peak of the $^1_a$ band and the polarizability parameter $(n^{2}-1)/(2n^{2}+1)$.The calculated refractive index values for SPMV, SPMTL and SPMPL were close to 1.50, which is higher than that of liquid paraffin (n=l.475). The probe location was also determined by using a polarity parameter $(f-1/2f^{I})$. Here f=$({\varepsilon}-1)/(2{\varepsilon}+1)$ is the dielectric constant function and $f^I=(n^2-1)/(2n^2+1)$ is the refractive index function. A correlation existed between the monomer fluorescence intensity ratio and the solvent polarity parameter. The probes incorporated in SPMV, SPMTL, and SPMPL report a polarity value close to that of 1-hexanol $({\varepsilon}=13.29)$. In conclusion, Py-3-Py is located completely inside the membrane, not in the very hydrophobic core, but displaced toward the polar head groups of phospholipid molecules, e.g., central methylene region of aliphatic chains of phospholipid molecules.

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Bioactive characteristics of an implant surface coated with a pH buffering agent: an in vitro study

  • Pae, Hyung-Chul;Kim, Su-Kyoung;Park, Jin-Young;Song, Young Woo;Cha, Jae-Kook;Paik, Jeong-Won;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • v.49 no.6
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    • pp.366-381
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    • 2019
  • Purpose: The purpose of this study was to evaluate the effectiveness of conventional sandblasted, large-grit, acid-etched (SLA) surface coated with a pH buffering solution based on surface wettability, blood protein adhesion, osteoblast affinity, and platelet adhesion and activation. Methods: Titanium discs and implants with conventional SLA surface (SA), SLA surface in an aqueous calcium chloride solution (CA), and SLA surface with a pH buffering agent (SOI) were prepared. The wetting velocity was measured by the number of threads wetted by blood over an interval of time. Serum albumin adsorption was tested using the bicinchoninic acid assay and by measuring fluorescence intensity. Osteoblast activity assays (osteoblast adhesion, proliferation, differentiation, mineralization, and migration) were also performed, and platelet adhesion and activation assays were conducted. Results: In both the wetting velocity test and the serum albumin adsorption assay, the SOI surface displayed a significantly higher wetting velocity than the SA surface (P=0.000 and P=0.000, respectively). In the osteoblast adhesion, proliferation, differentiation, and mineralization tests, the mean values for SOI were all higher than those for SA and CA. On the osteoblast migration, platelet adhesion, and activation tests, SOI also showed significantly higher values than SA (P=0.040, P=0.000, and P=0.000, respectively). Conclusions: SOI exhibited higher hydrophilicity and affinity for proteins, cells, and platelets than SA. Within the limits of this study, it may be concluded that coating an implant with a pH buffering agent can induce the attachment of platelets, proteins, and cells to the implant surface. Further studies should be conducted to directly compare SOI with other conventional surfaces with regard to its safety and effectiveness in clinical settings.

Effect of Lactobacillus casei and a Fermented Milk on the Growth and Aflatoxin Production of Asperillus Parasiticus (유산균과 그 발효유가 Asperigllus parasiticus의 생육과 Aflatoxin 생성에 미치는 영향)

  • 김종규;이용욱
    • Journal of Food Hygiene and Safety
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    • v.13 no.2
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    • pp.164-170
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    • 1998
  • In this study a commercial fermented milk produced in Korea and a Lactobacillus strain used for the product (L. casei) were found to affect mold growth and inhibit aflatoxin production by Aspergillus parasiticus ATCC 15517. Aflatoxins were determined using an HPLC system that consisted of a $C_{18}$ column and a fluorescence detector. When the fermented milk was added to the yeast-extract broth the levels of aflatoxin $B_{1}\;and\;G_{1}$ significantly decreased by 48.6~58.1% and 29.8~34.2%, respectively (p$B_{1}\;and\;G_{1}$ were found in comparison with the control (monoculture). L. casei was found to be very inhibitory to the growth of A. parasiticus for 5 days, but no significant difference of mycelial weight was observed between the mixed culture and control at the end of incubation. The pH values of the culture broth in mixed culture were observed to be significantly lower than those in monoculture (p

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3D Shape Reconstruction using the Focus Estimator Value from Multi-Focus Cell Images (다초점 세포 영상으로부터 추정된 초점 값을 이용한 3차원 형태 복원)

  • Choi, Yea-Jun;Lee, Dong-Woo;Kim, Myoung-Hee;Choi, Soo-Mi
    • Journal of the Korea Computer Graphics Society
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    • v.23 no.4
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    • pp.31-40
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    • 2017
  • As 3D cell culture has recently become possible, it has been able to observe a 3D shape of cell and volume. Generally, 3D information of a cell should be observed with a special microscope such as a confocal microscope or an electron microscope. However, a confocal microscope is more expensive than a conventional microscope and takes longer time to capture images. Therefore, there is a need for a method that can reconstruct the 3D shape of cells using a common microscope. In this paper, we propose a method of reconstructing 3D cells using the focus estimator value from multi-focal fluorescence images of cells. Initially, 3D cultured cells are captured with an optical microscope by changing the focus. Then the approximate position of the cells is assigned as ROI (Region Of Interest) using the circular Hough transform in the images. The MSBF (Modified Sliding Band Filter) is applied to the obtained ROI to extract the outlines of the cell clusters, and the focus estimator values are computed based on the extracted outlines. Using the computed focus estimator values and the numerical aperture (NA) of the microscope, we extract the outline of the cell cluster considering the depth and reconstruct the cells into 3D based on the extracted outline. The reconstruction results are examined by comparing with the combined in-focus portions of the cell images.

Bioequivalence and Pharmacokinetics of 70 mg Alendronate Sodium Tablets by Measuring Alendronate in Plasma

  • Yun Min-Hyuk;Woo Jong-Su;Kwon Kwang-Il
    • Archives of Pharmacal Research
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    • v.29 no.4
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    • pp.328-332
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    • 2006
  • The bioequivalence and pharmacokinetics of alendronate sodium tablets were examined by determining the plasma concentration of alendronate. Two groups, consisting of 24 healthy volunteers, each received a 70 mg reference alendronate sodium tablet and a test tablet in a $2{\times}2$ crossover study. There was a 6-day washout period between doses. The plasma alendronate concentration was monitored for 7 h after the dose, using HPLC-Fluorescence Detector (FD). The area under the plasma concentration-time curve from time 0 to the last sampling time at 7 h $(AUC_{0-7h})$ was calculated using the linear-log trapezoidal rule. The maximum plasma drug concentration $(C_{max})$ and the time to reach $C_{max}(T_{max})$ were derived from the plasma concentration-time data. Analysis of variance was performed using logarithmically transformed $AUC_{0-7h}\;and\;C_{max}$, and untransformed $T_{max}$. For the test medication versus the reference medication, the $AUC_{0-7h}\;were\;87.63{\pm}29.27\;vs.\;102.44{\pm}69.96ng\;h\;mL^{-1}$ and the $C_{max}$ values were $34.29{\pm}13.77\;vs.\;38.47{\pm}24.39ng\;mL^{-1}$ respectively. The $90\%$ confidence intervals of the mean differences of the logarithmic transformed $AUC_{0-7h}$ and $C_{max}$ values were log 0.8234-log 1.1597 and log 0.8222-log 1.1409, respectively, satisfying the bioequivalence criteria guidelines of both the US Food and Drug Administration and the Korea Food and Drug Administration. The other pharmacokinetic parameters for the test drug versus reference drug, respectively, were: $t_{1/2},\;1.87{\pm}0.62\;vs.\;1.77{\pm}0.54\;h;\;V/F,\;2061.30{\pm}986.49\;vs.\;2576.45{\pm}1826.05\;L;\;CL/F,\;835.32{\pm}357.35\;vs.\;889.48{\pm}485.87\;L\;h^{-1}; K_{el},\;0.42{\pm}0.14\;vs.\;0.40{\pm}0.18\;h^{-1};\;Ka,\;4.46{\pm}3.63\;vs.\;3.80{\pm}3.64\;h^{-1};\;and\;T_{lag},\;0.19{\pm}0.09\;vs.\;0.18{\pm}0.06\;h$. These results indicated that two alendronate formulations(70-mg alendronate sodium) were biologically equivalent and can be prescribed interchangeably.