• Title/Summary/Keyword: Enhancers

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Refolding of Fusion Ferritin by Gel Filtration Chromatography(GFC)

  • Kim, Hyung-Won;Kim, In-Ho
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.6
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    • pp.500-504
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    • 2005
  • Fusion ferritin (heavy chain ferritin, $F_H+$ light chain ferritin, $F_L$), an iron-binding protein, was primarily purified from recombinant Escherichia coli by two-step sonications with urea [1]. Unfolded ferritin was refolded by gel filtration chromatography (GFC) with refolding enhancer, where 50 mM Na-phosphate (pH 7.4) buffer containing additives such as Tween 20, PEG, and L-arginine was used. Ferritin is a multimeric protein that contains approximately 20 monomeric units for full activity. Fusion ferritin was expressed in the form of inclusion bodies (IBs). The IBs were initially solubilized in 4 M urea denaturant. The refolding process was then performed by decreasing the urea concentration on the GFC column to form protein multimers. The combination of the buffer-exchange effect of GFC and the refolding enhancers in refolding buffer resulted in an efficient route for producing properly folded fusion ferritin.

Enteral nutrition of the premature infant

  • Cho, Su Jin
    • Clinical and Experimental Pediatrics
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    • v.53 no.1
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    • pp.7-13
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    • 2010
  • Early nutritional support for preterm infants is critical because such support influences long-term outcome. Minimal enteral feeding should be initiated as soon as possible if an infant is stable and if feeding advancement is recommended as relevant to the clinical course. Maternal milk is the gold standard for enteral feeding, but fortification may be needed to achieve optimal growth in a rapidly growing premature infant. Erythromycin may aid in promoting gastrointestinal motility in cases that exhibit feeding intolerance. Selected preterm infants need vitamins, mineral supplements, and calorie enhancers to meet their nutritional needs. Despite all that is known about this topic, additional research is needed to guide postdischarge nutrition of preterm infants in order to maintain optimal growth and neurodevelopment.

Transcriptional activity of the short gastrulation primary enhancer in the ventral midline requires its early activity in the presumptive neurogenic ectoderm

  • Shin, Dong-Hyeon;Hong, Joung-Woo
    • BMB Reports
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    • v.49 no.10
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    • pp.572-577
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    • 2016
  • The short gastrulation (sog) shadow enhancer directs early and late sog expression in the neurogenic ectoderm and the ventral midline of the developing Drosophila embryo, respectively. Here, evidence is presented that the sog primary enhancer also has both activities, with the late enhancer activity dependent on the early activity. Computational analyses showed that the sog primary enhancer contains five Dorsal (Dl)-, four Zelda (Zld)-, three Bicoid (Bcd)-, and no Single-minded (Sim)-binding sites. In contrast to many ventral midline enhancers, the primary enhancer can direct lacZ expression in the ventral midline as well as in the neurogenic ectoderm without a canonical Simbinding site. Intriguingly, the impaired transcriptional synergy between Dl and either Zld or Bcd led to aberrant and abolished lacZ expression in the neurogenic ectoderm and in the ventral midline, respectively. These findings suggest that the two enhancer activities of the sog primary enhancer are functionally consolidated and geographically inseparable.

Safety Evaluation of Polyethylene Glycol (PEG) Compounds for Cosmetic Use

  • Jang, Hyun-Jun;Shin, Chan Young;Kim, Kyu-Bong
    • Toxicological Research
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    • v.31 no.2
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    • pp.105-136
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    • 2015
  • Polyethylene glycols (PEGs) are products of condensed ethylene oxide and water that can have various derivatives and functions. Since many PEG types are hydrophilic, they are favorably used as penetration enhancers, especially in topical dermatological preparations. PEGs, together with their typically nonionic derivatives, are broadly utilized in cosmetic products as surfactants, emulsifiers, cleansing agents, humectants, and skin conditioners. The compounds studied in this review include PEG/PPG-17/6 copolymer, PEG-20 glyceryl triisostearate, PEG-40 hydrogenated castor oil, and PEG-60 hydrogenated castor oil. Overall, much of the data available in this review are on PEGylated oils (PEG-40 and PEG-60 hydrogenated castor oils), which were recommended as safe for use in cosmetics up to 100% concentration. Currently, PEG-20 glyceryl triisostearate and PEGylated oils are considered safe for cosmetic use according to the results of relevant studies. Additionally, PEG/PPG-17/6 copolymer should be further studied to ensure its safety as a cosmetic ingredient.

Midline enhancer activity of the short gastrulation shadow enhancer is characterized by three unusual features for cis-regulatory DNA

  • Shin, Dong-Hyeon;Hong, Joung-Woo
    • BMB Reports
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    • v.48 no.10
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    • pp.589-594
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    • 2015
  • The shadow enhancer of the short gastrulation (sog) gene directs its sequential expression in the neurogenic ectoderm and the ventral midline of the developing Drosophila embryo. Here, we characterize three unusual features of the shadow enhancer midline activity. First, the minimal regions for the two different enhancer activities exhibit high overlap within the shadow enhancer, meaning that one developmental enhancer possesses dual enhancer activities. Second, the midline enhancer activity relies on five Single-minded (Sim)-binding sites, two of which have not been found in any Sim target enhancers. Finally, two linked Dorsal (Dl)- and Zelda (Zld)-binding sites, critical for the neurogenic ectoderm enhancer activity, are also required for the midline enhancer activity. These results suggest that early activation by Dl and Zld may facilitate late activation via the noncanonical sites occupied by Sim. We discuss a model for Zld as a pioneer factor and speculate its role in midline enhancer activity.

Transdermal permeation-enhancing activity of N-adamantyl n-alkanamides for lbuprofen in the rabbit

  • Han, Suk-Kyu;Park, Yong-Hoon;Ko, Young-Ill;Kim, Young-Mi
    • Archives of Pharmacal Research
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    • v.19 no.2
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    • pp.95-99
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    • 1996
  • Four N-adamantyl n-alkanamides were prepared by amide condensation reaction between amantadine and n-alkanoic acid. Their enhancing activity on the penetration of ibuprofen through rabbit skin from petrolatum ointment was evaluated in in-vivo experiment. The experiments showed that the compounds have a strong transdermal penetration-enhancing activity, and their activities were comparable with that of Azone. The measurements of the fluorescence polarization of DP[-i-labelled DPPC liposomes showed that these compounds considerablly decreased the phase transition temperature of the liposomes. The mechanism of the transdermal penetration-enhancing activity of the compounds was ascribed to the reduction of the resistance to drug flux of the stratum corneum lipid layers due to the loose packing of the layers when the bulk head group of the enhancers inserts into the layers.

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Effect of skin penetration enhancer on the drug release from indomethacin-soft hydrogel (인도메타신 소프트 하이드로겔로 부터 약물 방출에 미치는 피부투과촉진제의 영향)

  • Nam, Hyun-Gue;Lee, Chi-Ho;Shin, Young-Hee
    • Journal of Pharmaceutical Investigation
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    • v.32 no.1
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    • pp.35-40
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    • 2002
  • We prepared a novel dosage form, peel-off type soft hydrogel using poly(vinyl alcohol), and evaluated the effect of skin penetration enhancer on the indomethacin release from soft hydrogel by in vitro permeation and in vivo absorption test. In this study, we used four enhancers-urea, dimethyl urea, 1,1,3,3-tetramethyl urea, and pirotiodecane (1-[2(decylthio)ethyl]azacyclopentane-2-one, $HPE-101^{circledR}$). In addition, we evaluated the primary skin irritation test of soft hydrogel using rabbit. From these results, we could find the pirotiodecane was a prominent enhancer, and soft hydrogel seemed to be safe and have no irritancy.

Genetic Screen for Genes Involved in Chk2 Signaling in Drosophila

  • Park, Suk-Young;Song, Young-Han
    • Molecules and Cells
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    • v.26 no.4
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    • pp.350-355
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    • 2008
  • Chk2 is a well characterized protein kinase with key roles in the DNA damage response. Chk2 is activated by phosphorylation following DNA damage, and relays that signal to various substrate proteins to induce cell cycle arrest, DNA repair, and apoptosis. In order to identify novel components of the Chk2 signaling pathway in Drosophila, we screened 2,240 EP misexpression lines for dominant modifiers of an adult rough eye phenotype caused by Chk2 overexpression in postmitotic cells of the eye imaginal disc. The rough eye phenotype was suppressed by mutation of the ATM kinase, a well-described activator of Chk2. Twenty-five EP modifiers were identified (three enhancers and 22 suppressors), none of which correspond to previously known components of Chk2 signaling. Three EPs caused defects in G2 arrest after irradiation with incomplete penetrance when homozygous, and are likely directly involved in the response to DNA damage. Possible roles for these modifiers in the DNA damage response and Chk2 signaling are discussed.

Inhibitory effects of Thalictrum rochebrunianum var. grandisepalum on tyrosinase in IBMX-induced B16F10 melanoma cells

  • Jang, Tae-Won;Choi, Ji-Soo;Mun, Jeong-Yun;Im, Jong-Yun;Nam, Su-Hwan;Kim, Do-Wan;Lee, Seung-Hyun;Park, Jae-Ho
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.04a
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    • pp.116-116
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    • 2019
  • Thalictrum rochebrunianum var. grandisepalum (TRG) is a Korean endemic plant, and it is widely used for edible, medicinal, landscape materials. In this study, we examined the protein and mRNA expression levels of MITF, tyrosinase, TRP-1 and TRP-2 by TRG extract (TRGE) in IBMX-treated melanocytes to evaluate the possibility of using TRG as a whitening material. IBMX were reported as melanin synthesis enhancers. It could increase intracellular melanin synthesis by activation of the microphthalmia-associated transcription factor (MITF) signaling pathway. TRGE did not show cytotoxicity at concentrations below $100{\mu}g/ml$ in B16F10 cells. TREG dose-dependently inhibited protein and mRNA levels of MITF, tyrosinase, TRP-1 and TRP-2. Therefore, we suggest that TRGE is an important natural resource for cosmetic raw materials for whitening function.

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Domestic and International Trends in Technologies for Sodium Reduction (국내외 나트륨 저감 기술 동향)

  • Jung, Kwangho
    • Food Science and Industry
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    • v.49 no.2
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    • pp.18-24
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    • 2016
  • Sodium chloride (NaCl) is a very important as one of major food ingredients in food industries. Recently, as the potential risk of adult diseases such as hypertension by overingestion of sodium, health authorities of many countries are executing policies for the reduction of sodium to suppress the overingestion of sodium by intake of NaCl. As general ways, the replacement of NaCl with either alternative salts, such as solar salts and minerals, for examples calcium, magnesium, potassium, lactic acid, and so on, and the addition of flavor enhancers were used to reduce the contents of sodium in foods. Recently, controls of particle size of sodium chloride or release point are emerging as new salt-manufacturing technologies for the sodium reduction. Upon reducing NaCl in foods it is important to develop practically adaptable technologies on the basis of the consideration of the unique functions of NaCl in foods, in particular effects on rheological characters, function as a humectant, shorten shelf life time, and so on.