• Title/Summary/Keyword: HEPES

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Transformation of Rhizobacteria Pseudomonas fluorescens by Electroporation (Electroporation에 의한 근권 미생물 Pseudomonas fluorescens의 형질전환)

  • Kim, Jong-Hyun;Rhee, Young-Hwan
    • Applied Biological Chemistry
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    • v.38 no.5
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    • pp.371-375
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    • 1995
  • The antagonistic rhizobacteria Pseudomonas(P.) fluorescens against F. oxysporum and R. solani were isolated and selected, and then, their biological and physiological characteristics were investigated. The posibility and optimum condition of the electroporation of antagonistic rhizobacteria with Ps70, one of the selected one, and plasmid pSV2-neo was studied. Its optimum condition was found with HGEB which contains 1 mM (pH 7.0) hepes and 10% glycerol at setting of 200 resistance, 25 ${\mu}F$ capacitance, and 2.5 kV applied voltage. In addition, the transformation efficiency obtained with pSV2-neo was compared to other plasmids with different sizes. The applied voltage, the buffer composition and the parallel resistor (time constant) were shown to have the greatest effect on transformation efficiency in electroporation. And the rest of the selected rhizobacteria were also successfully transformed with pSV2-neo by electroporation.

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Effects of Transport Duration on Viability of In Vitro Produced Korean Native Cattle Embryos (한우 체외수정란의 이동 소요시간이 생존율에 미치는 영향)

  • 박희성
    • Journal of Embryo Transfer
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    • v.12 no.3
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    • pp.307-313
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    • 1997
  • Experiments were conducted to assess the effect of quality and viability of bovine blastocysts derived from in-vitro culture(IVC) of in vitro matured and fertilized(IVM-IVF) oocytes during their transport 2 hours. Follicular oocytes were collected form ovaries obtained at a slaughterhouse and were cultured for 24 hours in TCM-199. The IVM oocytes were fertilized in vitro with caudal epididymis spermatozoa. Fertilized oocytes were cultured for 7 to 9 days, and embryos that developed to the blastocyst stage were used for the experiment. The blastocysts, packed in straws with storage medium that consisted TCM-199 with HEPES equilibratd in air and supplemented with 10% FCS were transported at 39~(2.0 h). The quality of blastocysts was assessed and ranked as A(excel-lent), B(Good), fair or poor after transportation. The percentages of A and B grade blastocysts after transport duration for < 1 hours(97.7%) were similar to the result from transport duration for 1~2 hours (92.9%) and 2~3 hours(89.6%), but significantly(P<0.05) higher than transpot duration for 3~4 hours(76.3%). The percentages of A and B grade blastocysts after transport duration for two hours from developed blastocyst at 7day(100%) and 8day(85.0%) were higher 9day(96.6%) and >9day (40.0%). And early to expanded blastocyst produced in vitro were transferred to recipient cow by additional embryos at 7 and 8th day after AI. Three of them were pregnant to term and produced four twin calves, and two calves was premature birth. The gestation lengths of male to female and female to female twin were 282 and 281 days, respectively. And birth weight of twin calves were male to female(22.Skg) and female to female twin(20.3Okg), respectively.

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N-acetyl-L-cysteine and cysteine increase intracellular calcium concentration in human neutrophils

  • Hasan, Md. Ashraful;Ahn, Won-Gyun;Song, Dong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.5
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    • pp.449-457
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    • 2016
  • N-acetyl-L-cysteine (NAC) and cysteine have been implicated in a number of human neutrophils' functional responses. However, though $Ca^{2+}$ signaling is one of the key signalings contributing to the functional responses of human neutrophils, effects of NAC and cysteine on intracellular calcium concentration ($[Ca^{2+}]_i$) in human neutrophils have not been investigated yet. Thus, this study was carried out with an objective to investigate the effects of NAC and cysteine on $[Ca^{2+}]_i$ in human neutrophils. We observed that NAC ($1{\mu}M{\sim}1mM$) and cysteine ($10{\mu}M{\sim}1mM$) increased $[Ca^{2+}]_i$ in human neutrophils in a concentration-dependent manner. In NAC pre-supplmented buffer, an additive effect on N-formyl-methionine-leucine-phenylalanine (fMLP)-induced increase in $[Ca^{2+}]_i$ in human neutrophils was observed. In $Ca^{2+}$-free buffer, NAC- and cysteine-induced $[Ca^{2+}]_i$ increase in human neutrophils completely disappeared, suggesting that NAC- and cysteine-mediated increase in $[Ca^{2+}]_i$ in human neutrophils occur through $Ca^{2+}$ influx. NAC- and cysteine-induced $[Ca^{2+}]_i$ increase was effectively inhibited by calcium channel inhibitors SKF96365 ($10{\mu}m$) and ruthenium red ($20{\mu}m$). In $Na^+$-free HEPES, both NAC and cysteine induced a marked increase in $[Ca^{2+}]_i$ in human neutrophils, arguing against the possibility that $Na^+$-dependent intracellular uptake of NAC and cysteine is necessary for their $[Ca^{2+}]_i$ increasing activity. Our results show that NAC and cysteine induce $[Ca^{2+}]_i$ increase through $Ca^{2+}$ influx in human neutrophils via SKF96365- and ruthenium red-dependent way.

Municipal Solid Waste-derived Syngas Fermentation Process by Pressurization (가압을 통한 도시형 생활 폐기물 기반 합성가스발효 공정 개발)

  • Subin Shin;Jae Hee Go;Myounghoon Moon;Min-Sik Kim;Mungyu Lee;In Seop Chang;Seongsoo Son;Gwon Woo Park
    • New & Renewable Energy
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    • v.19 no.4
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    • pp.35-45
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    • 2023
  • Global efforts are focused on achieving carbon neutrality due to the increases in the levels of greenhouse gases. Moreover, the greenhouse gases generated from the disposal of municipal solid waste (MSW) are the primary sources of emissions in South Korea. In this study, we conducted the biological conversion of syngas (CO, H2, and CO2) generated from MSW gasification. The MSW-derived syngas was used as a feed source for cultivating Eubacterium limosum KIST612, and pressurization was employed to enhance gas solubility in culture broth. However, the pH of the medium decreased owing to the pressurization because of the CO2 in the syngas and the cultivation-associated organic acid production. The replacement of conventional HEPES buffer with a phosphate buffer led to an approximately 2.5-fold increase in acetic acid concentration. Furthermore, compared with the control group, the pressurized reactor exhibited a maximum 8.28-fold increase in the CO consumption rate and a 3.8-fold increase in the H2 consumption rate.

Effect of Glucose Exposure on the Development of the Mouse Preimplantation Embryo In Vitro (착상전 생쥐배아의 Glucose에 대한 노출이 체외 배발생에 미치는 영향)

  • Kim, Seon-Ui;Eom, Sang-Jun;Yun, San-Hyeon;Im, Jin-Ho;Jeong, Gil-Saeng
    • Korean Journal of Animal Reproduction
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    • v.19 no.3
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    • pp.227-234
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    • 1995
  • This study was carried out to investigate the effects according to the time course of glucose exposure on the development of one-cell embryos beyond morula in CR$_laa$ medium. One-cell zygotes from B6CBA F$_1$ mice were recovered at 24 ~ 25h after hCG and cumulus cells were removed with 0.1% hyaluronidase. The embryos were pooled and subsequently divided into each groups and cultured in CR$_laa$ at 37$^{\circ}C$ in 5% CO$_2$ in aIr. The embryos were either, placed in CR$_laa$ containing various concentration (5.5, 16.5, 27.5 and 38.5 mM) of glucose for 1 min. and subsequently returned to the fresh culture medium (without glucose), or were transferred to the same media containing glucose at 72 h post hCG. The results obtained in these experiments were summarized as follows: 1. The development rates of zygotes, recovered from the oviducts in M2 and cultured in CR$_laa$ with 3mg/Im FAF-BSA, to expanded blastocysts (25.7%) and hatching bIastocysts (17.6%) were significantly higher than those of zygotes recovered in TL Hepes (0% and 0%, respectively). 2. The development rates of one-cell embryos exposed to 27.5 mM glucose at 72 h post hCG for 1 min, were 68.8% (CR$_1$+BSA) a and 77.1% (CR$_1$+FBS) of expanded blastocyst stage, but there were no significant differences between the embryos exposed for 1 min. or transferred at 72 h. 3. Regardless of glucose concentration (5.5, 16.5, 27.5 & 38.5mM), 45.7~61.5% of embryos developed to the blastocyst stage. There were no significant differences between any of the treatments on the devel-opment of one-cell embryos. Therefore, the detrimental effect of highly concentration was not appeared.

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Alteration of Phospholipase D Activity in the Rat Tissues by Irradiation (방사선 조사에 의한 쥐 조직의 포스포리파제 D의 활성 변화)

  • Choi Myung Sun;Cho Yang Ja;Choi Myung-Un
    • Radiation Oncology Journal
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    • v.15 no.3
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    • pp.197-206
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    • 1997
  • Purpose : Phospholipase D (PLD) catalyzes the hydrolysis of phosphatidylcholine to phosphatidic acid (PA) and choline. Recently, PLD has been drawing much attentions and considered to be associated with cancer Process since it is involved in cellular signal transduction. In this experiment, oleate-PLD activities were measured in various tissues of the living rats after whole body irradiation. Materials and Methods : The reaction mixture for the PLD assay contained $0.1\;\muCi\;1,2-di[1-^{14}C]palmitoyl$ phosphatidylcholine 0.5mM phosphatidylcholine, 5mM sodium oleate, $0.2\%$ taurodeoxycholate, 50mM HEPES buffer(pH 6.5), 10mM $CaCl_2$, and 25mM KF. phosphatidic acid, the reaction product, was separated by TLC and its radioactivity was measured with a scintillation counter. The whole body irradiation was given to the female Wistar rats via Cobalt 60 Teletherapy with field size of 10cmx loom and an exposure of 2.7Gy per minute to the total doses of 10Gy and 25Gy. Results : Among the tissues examined, PLD activity in lung was the highest one and was followed by kidney, skeletal muscle, brain, spleen, bone marrow, thymus, and liver. Upon irradiation, alteration of PLD activity was observed in thymus, spleen, lung, and bone marrow. Especially PLD activities of the spleen and thymus revealed the highest sensitivity toward $\gamma-rar$ with more than two times amplification in their activities In contrast, the PLD activity of bone marrow appears to be reduced to nearly $30\%$. Irradiation effect was hardly detected in liver which showed the lowest PLD activity. Conclusion : The PLD activities affected most sensitively by the whole-body irradiation seem to be associated with organs involved in immunity and hematopoiesis. This observation s1ron91y indicates that the PLD is closely related to the physiological function of these organs, Furthermore, radiation stress could offer an important means to explore the phenomena covering from cell Proliferation to cell death on these organs.

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Cellular Pathways in Agonist-induced Gallbladder Muscle Contraction in the Cat (고양이의 담낭근 수축에 있어서 세포내 기전)

  • Rhim, Byung-Yong;Kim, Chi-Dae;Kim, Dong-Heon;Biancani, Piero;Behar, Jose
    • The Korean Journal of Pharmacology
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    • v.32 no.1
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    • pp.67-74
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    • 1996
  • Cholecystokinin octapeptide (CCK-8), acetylcholine (ACh) and KCl caused a dose dependent contraction in muscle cells enzymatically digested from cat gallbladder. Maximal contraction was obtained at concentration of $10^{-9}M$ for CCK-8, $10^{-5}M$ for ACh and 20mM for KCl. CCK-8 induced contraction was unaffected in calcium free physiological salt solution (PSS) and was completely blocked by strontium substitution for calcium (p<0.001). In contrast, KCl evoked contraction was blocked in calcium free PSS (p<0.01) but was unaffected by strontium replacement of calcium. The contraction elicited by ACh was only slightly reduced in calcium free PSS (p<0.05) and was unaltered by strontium. Muscle cells permeabilized with saponin contracted in response to inositol 1,4.5-trisphosphate $(IP_3)$ and CCK-8. The contraction was blocked by the calmodulin antagonist CGS 9343B (p<0.001), whereas heparin completely blocked the effect of $IP_3$ (p<0.001). The protein kinase C (PKC) antagonist H7 had no effect on either agonist. We conclude that CCK-8 induced gallbladder muscle contraction is mediated by $IP_3$ dependent intracellular calcium release from intracellular stores and a calmodulin dependent pathway; ACh may utilize both extracellular and intracellular calcium. KCl causes muscle contracrion through influx of extracellular calcium and a calmodulin independent machanism.

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Characteristics of [$^{18}F$]fluorodeoxyglucose Uptake in Human Colon Cancer Cells (사람 대장암 세포주의 [$^{18}F$fluorodeoxyglucose 섭취의 특징)

  • Kim, Chae-Kyun;Jeong, Jae-Min;Lee, Myung-Chul;Koh, Chang-Soon;Chung, June-Key
    • The Korean Journal of Nuclear Medicine
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    • v.31 no.3
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    • pp.381-387
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    • 1997
  • Cancer tissues are characterized by increased glucose uptake. $^{18}F$-fluorodeoxyglucose(FDG), a glucose analogue is used for the diagnosis of cancer in PET studies. This study was aimed to compare the glucose uptake and glucose transporter 1(GLUT1) expression in various human colon cancer cells. We measured FDG uptake by cell retention study and expression of GLUT1 using Western blotting. Human colon cancer cells, SNU-C2A, SNU-C4 and SNU-C5, were used. The cells were incubated with $1{\mu}Ci/ml$ of FDG in HEPES-buffered saline for one hour. The FDG uptake of SNU-C2A, SNU-C4 and SNU-C5 were $16.8{\pm}1.36,\;12.3{\pm}5.55$ and $61.0{\pm}2.17cpm/{\mu}g$ of protein, respectively. Dose-response and time-course studies represent that FDG uptake of cancer cells were dose dependent and time dependent. The rate of FDG uptake of SNU-C2A, SNU-C4 and SNU-C5 were $0.29{\pm}0.03,\;0.21{\pm}0.09$ and $1.07{\pm}0.07cpm/min/{\mu}g$ of protein, respectively. Western blot analysis showed that the GLUT1 expression of SNU-C5 was significantly higher than those of SNU-C2A and SNU-C4. These results represent that FDG uptake into human colon cancer cells are different from each other. In addition, FDG uptake and expression of GLUT1 are closely related in human colon cancer cells.

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A Comparative Study of Production of [68Ga]PSMA-11 with or without Cassette Type Modules (비 카세트 방식과 카세트 방식을 이용한 [68Ga]PSMA-11의 자동 합성 방법 비교)

  • Hyun-Sik, Park;Byeong-Min, Jo;Hyun-Ho, An;Hong-Jin, Lee;Jin-Hyeong, Lee;Gyeong-Jae, Lee;Byung-Chul, Lee;Won-Woo, Lee
    • The Korean Journal of Nuclear Medicine Technology
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    • v.26 no.2
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    • pp.15-19
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    • 2022
  • Purpose [68Ga]PSMA-11 is needed the high reproducibility, excellent radiochemical yield and purity. In term of radiation safety, the radiation exposure of operator for its production also should be considered. In this work, we performed a comparative study for the fully automated synthesis of [68Ga]PSMA-11 between non-cassette type and cassette type. Materials and Methods Two different type of modules (TRACERlab FX N pro for non-cassette type and BIKBox for cassette type) were used for the automated production of [68Ga]PSMA-11. According to the previously identified elution profile, Only 2.5 ml with high radioactivity was used for the reaction. After adjusting the pH of the reaction solution with HEPES buffer solution, the precursor was added and reacted with at 95 ℃ for 15 minutes. The reaction mixture was separated and purified using a C18 light cartridge. The product was eluted with 50% EtOH/saline solution and diluted with saline. It was completed by sterilizing filter. In the non-cassette type, the aforementioned process must be prepared directly. However, in the cassette method, synthesis was possible simply by installing a kit that was already completed. Results Both total [68Ga]PSMA-11 production time were 25±3(non-cassette type) and 23±3 minutes(cassette type). The radiochemical yield of the non-cassette type(65.5±5.7%) was higher than that of the cassette type(61.6±4.8%) after sterilization filter. The non-cassette type took about 120 minutes of preparation time before synthesis due to washing of synthesizer and reagent preparation. However, since the cassette type does not require washing and reagent preparation, it took about 20 minutes to prepare before synthesis. Both type of synthesizer had a radiochemical high purity(>99%). Conclusion The non-cassette type production of [68Ga]PSMA-11 showed higher radiochemical yield and lower cost than the cassette type. However, The cassette type has an advantage in terms of preparation time, convenience, and equipment maintenance.

Effect of $H_2O_2$ on Alveolar Epithelial Barrier Properties (폐상피세포 장벽에 대한 $H_2O_2$의 영향)

  • Suh, Duk-Joon;Cho, Se-Heon;Kang, Chang-Woon
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.3
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    • pp.236-249
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    • 1993
  • Background: Among the injurious agents to which the lung airspaces are constantly exposed are reactive species of oxygen. It has been widely believed that reactive oxygen species may be implicated in the etiology of lung injuries. In order to elucidated how this oxidant causes lung cell injury, we investigated the effects of exogenous $H_2O_2$ on alveolar epithelial barrier characteristics. Methods: Rat type II alveolar epithelial cells were plated onto tissue culture-treated polycarbonate membrane filters. The resulting confluent monolayers on days 3 and 4 were mounted in a modified Ussing chamber and bathed on both sides with HEPES-buffered Ringer solution. The changes in short-circuit current (Isc) and monolayer resistance (R) in response to the exogenous hydroperoxide were measured. To determine the degree of cellular catalase participation in protection against $H_2O_2$ injury to the barrier, experiments were repeated in the presence of 20 mM aminotriazole (ATAZ, an inhibitor of catalase) in the same bathing fluid as the hydroperoxide. Results: These monolayers have a high transepithelial resistance (>2000 ohm-$cm^2$) and actively transport $Na^+$ from apical fluid. $H_2O_2$(0-100 mM) was then delivered to either apical or basolateral fluid. Resulting indicated that $H_2O_2$ decreased Isc and R gradually in dose-dependent manner. The effective concentration of apical $H_2O_2$ at which Isc (or R) was decreased by 50% at one hour ($ED_{50}$) was about 4 mM. However, basolateral $H_2O_2$ exposure led to $ED_{50}$ for Isc (and R) of about 0.04 mM. Inhibition of cellular catalase yielded $ED_{50}$ for Isc (and R) of about 0.4 mM when $H_2O_2$ was given apically, while $ED_{50}$ for basolateral exposure to $H_2O_2$ did not change in the presence of ATAZ. The rate of $H_2O_2$ consumption in apical and basolateral bathing fluids was the same, while cellualr catalase activity rose gradually with time in culture. Conclusion: Our data suggest that basolateral $H_2O_2$ may affect directly membrane component (e.g., $Na^+,\;K^+$-ATPase) located on the basolateral cell surface. Apical $H_2O_2$, on the other hand, may be largely degraded by catalase as it passes through the cells before reaching these membrane components. We conclude that alveolar epithelial barrier integrity as measured by Isc and R are compromised by $H_2O_2$ being relatively sensitive to basolateral (and insensitive to apical) $H_2O_2$.

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