• Title/Summary/Keyword: Negative Activation

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Mast Cell Increase and Stem Cell Factor Receptor (c-kit) Expression in Helicobacter pylori-infected Gastritis (Helicobacter pylori 감염 위염에서의 비만세포 증가와 Stem Cell Factor Receptor (c-kit)의 발현)

  • Jekal, Seung-Joo
    • Korean Journal of Clinical Laboratory Science
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    • v.37 no.1
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    • pp.41-46
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    • 2005
  • It is known that mast cells (MCs) are increased in H. pylori-infected gastritis and its increase is mediated by stem cell factor (c-kit ligand). To determine the mechanism of mast cell recruitment and activation by stem cell factor, weinvestigated the expression of stem cell factor receptor (c-kit) in H. pylori-positive and -negative gastric mucosa. Biopsy specimens from 16 H. pylori-negative and 20 positive subjects were examined. H. pylori infection in gastric mucosa was examined by the Warthin-Starry method. MC and c-kit were identified by immunohistochemisty, using a monoclonal antihuman MC tryptase antibody and a polyclonal anti-human c-kit antibody. Densities of MC and c-kit positive cell were measured by a computerized image analysis system. MCs were detected in the lamina propria of both H. pylori-positive and -negative gastric mucosa. Densities of MC and c-kit positive cell were significantly greater in H. pylori-positive than -negative subjects. c-kit was located on the surface of MCs. These results indicate that stem cell factors may be one of the factors involved in mast cell increase and that they activate mast cells by binding with c-kit.

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Effect of Oocyte Maturation Medium, Cytochalasin Treatment and Electric Activation on Embryonic Development after Intracytoplasmic Sperm Injection in Pigs

  • Lee, Joohyeong;Choi, Jung Hoon;Lee, Seung Tae;Hyun, Sang-Hwan;Lee, Eunsong
    • Journal of Embryo Transfer
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    • v.28 no.2
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    • pp.127-132
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    • 2013
  • The objective of this study was to examine the effect of in vitro maturation (IVM) medium, cytochalasin B (CB) treatment during intracytoplasmic sperm injection (ICSI), and electric activation on in vitro development ICSI-derived embryos in pigs. Immature pig oocytes were matured in vitro in medium 199 (M199) or porcine zygote medium (PZM)-3 that were supplemented with porcine follicular fluid, cysteine, pyruvate, EGF, insulin, and hormones for the first 22 h and then further cultured in hormone-free medium for an additional 21~22 h. ICSI embryos were produced by injecting single sperm directly into the cytoplasm of IVM oocytes. The oocytes matured in PZM-3 with 61.6 mM NaCl (low-NaCl PZM-3) tended to decrease (0.05

The Cerebral Activation of the Emotional and Linguistic Attributes during Visual Word Recognition: fMRI Study (시각 단어 재인동안 정서적 속성과 언어적 속성에 의해 활성화되는 대뇌 영역 : fMRI 연구)

  • Park, Chang-Su;Han, Jong-Hye;Choi, Moon-Gee;Nam, Ki-Chun
    • Proceedings of the Korean Society for Cognitive Science Conference
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    • 2006.06a
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    • pp.53-58
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    • 2006
  • We examined the cerebral activation of the emotional and linguistic attributes during the visual word recognition. This research investigated the affective priming effect preserving the behavioral paradigm. We used the primed-evaluation task in which the participants classify the target as positive or negative, and manipulated the emtional attributes by emtional relations of the prime-target word pairs(PP, PN, NP, NN). ROIs analyses for the semantic processing and emotional processing were performed. The results showed that the semantic processing areas including the IPL, SMG, and aSTS were activated differently according to the experimental condition. The activations of the IPL were increased only on the NN condition, whereas the activation of the SMG was decreased only on the PP condition. Furthmore, the activation of the emotional processing areas including the mPFC and ACC, was different according to the emotional realtions of word pairs. Similar to the SMG, the BOLD signal of the mPFC was decreaed only on the PP condition, whereas the activation of ACC was Increased only on the NN condition. These results were seemed to show the interact ive cerebral activations for processing the emtoional and linguistic attributes in a word, during visual word recognition.

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The Effect of Pressure on the Electrophilic Substitution Reaction of Tetramethyltin with Iodine (Tetramethyltin과 Iodine의 친전자 치환반응에 대한 압력의 영향)

  • Kwun Oh Cheun;Lee Young Hoon
    • Journal of the Korean Chemical Society
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    • v.37 no.6
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    • pp.555-561
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    • 1993
  • Ultraviolet spectrophotometric investigation has been carried out on the system of iododestannylation iodine and tetramethyltin in methanol. The transient CT absorption spectrum can be observed and the subsequent disappearance of CT absorption spectrum was accompained by the cleavage of tetramethyltin with iodine. From there, the rate constants for the iododestannylation were determined at 10, 25 and 35$^{\circ}C$ up to 1600 bar and the reaction rates were increased with increasing temperature and pressure. From these rate constants, the values of the activation parameters (${\Delta}V^\neq,\;{\Delta}{\beta}^{\neq},\;{\Delta}H^{\neq},\;{\Delta}S^{\neq}\;and\;{\Delta}G^{\neq}$) were obtained. The activation volumes and activation compressibility coefficients were both negativity. The activation enthalpies were positive and activation entropies had large negative values. From these values discussed in terms of solvent structure variation of transition state and mechanism. From these results, it was found that the reaction is followed with $S_E2$ mechaenism and weakened $S_E2$ mechanism nature by increasing pressure.

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Correlation between Pelvic Tilt Angle with Trunk Motion and Trunk Extensor during Trunk Forward Flexion in Adults Aged 2,30 (2,30대 정상 성인남녀의 몸통 굽힘 시 골반의 기울임과 몸통 움직임 및 몸통 폄 근의 상관관계 연구)

  • Park, Youngju;Lee, Sangyeol
    • Journal of The Korean Society of Integrative Medicine
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    • v.7 no.1
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    • pp.81-88
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    • 2019
  • Purpose : The purpose of this study was to examine if there is any correlation between pelvic tilt angle and trunk motion and trunk extensor during trunk forward flexion and to measure trunk motion, onset time of trunk motion, and onset time of trunk extensor activation. Methods : The subjects of this study were 42 healthy adults. The subjects had no back pain due to neurological disease and no experience of back surgery. After pelvic tilt angle was measured, each trunk forward flexion was performed three times. Trunk motion and onset time of trunk motion were measured using Myomotion. Four sensors were used, with one located at the upper thoracic (below $C_7$), the lower thoracic ($T_{12}-L_1$), the sacrum ($S_1$), and at the center of the anterior femur. Onset time of trunk extensors (spinalis, longissimus, gluteus medius, gluteus maximus, biceps femoris, and gastrocnemius) activation was measured using a wireless surface EMG. The EMG amplitude was normalized by using the reference voluntary contraction (RVC). The statistical significance of the results were evaluated using Pearson's correlation test. Results : The correlation between pelvic tilt angle and lumbar motion, onset time of pelvis motion, and onset time of gluteus medius activation was statistically significant in a positive direction (p<.05). The correlation between pelvic tilt angle with pelvis motion, onset time of lumbar motion, and onset time of longissimus activation showed a statistically significant negative correlation (p<.05). Conclusion : The study results provide a significant contribution to our understanding of the lumbar load at the initial stage of trunk flexion. Therefore, it may be possible to provide basic data for evaluation and treatment, such as orthodontic treatment for alignment of the spine and back pain. In addition, it is necessary to focus on normal exercise pattern reeducation as well as pelvic correction during exercise in daily life or in industrial fields.

Kinetic Study on the Reaction of para-substitued Benzylbromide with Isoquinoline under High Pressure (고압하에서의 이소퀴놀린과 브롬화 벤질류의 반응에 관한 속도론적인 연구)

  • Kim, Young Cheul;Lim, Jong Wan;Choi, Sung Yong
    • Journal of the Korean Chemical Society
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    • v.42 no.2
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    • pp.150-155
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    • 1998
  • Kinetic studies on the reaction of isoquinoline with para-substituted benzylbromides were conducted under various pressures (1 ~1000 bar) in acetonitrile. From the rate constants obtained, the activation parameters such as$\DeltaV^{\neq}, \Delta\beta^{\neq}, \DeltaH^{\neq}, \DeltaS^{\neq}, \DeltaG^{\neq}$ and Ea were evaluated. Reaction rate increasing the pressure and temperature. The activation compressibility coefficient and the activation entropy showed negative values. From the substituent effect and the results, it was found that the reaction proceeds through $S_N2$ mechanism, but the structure of transition state was slightly changed with substituents and pressure.

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The Effects of Chungganhaeju-tang(Qingganjiejiu-tang) on $NF{\kappa}B$ Activation and Apoptosis of Kupffer Cells (청간해주탕(淸肝解酒湯)이 kupffer cell의 $NF{\kappa}B$ 활성화 및 세포사멸에 미치는 영향)

  • Han Chang-Woo;Kim Young-Chul;Woo Hong-Jung;Lee Jang-Hoon
    • The Journal of Internal Korean Medicine
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    • v.25 no.1
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    • pp.59-70
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    • 2004
  • Objectives : Previous studies showed that treatment with Chungganhaeju-tang prevents hepatic inflammation and apoptosis in alcoholic liver disease. The purpose of our study is to determine if any relations exsists between the transcription factor $NF{\kappa}B$, an orchestrating expression of a large number of genes and inhibitory effects of Chungganhaeju-tang on ethanol induced apoptosis. Materials and Methods : To assess the role of $NF{\kappa}B$, we blocked NFkB activation by delivering to the kupffer cells $I{\kappa}B{\Delta}N$, a dominant negative $NF{\kappa}B$ inhibitor, and investigated if Chungganhaeju-tang still prevented apoptosis. Results : When $NF{\kappa}B$ activation was blocked, there was no inhibitory effect of Chungganhaeju-tang on ethanol induced apoptosis of kupffer cells. Conclusion : This result suggests that Chungganhaeju-tang protects the liver from ethanol induced apoptosis by activating the $NF{\kappa}B$ that plays a key role in porotecting mechanism and reducing inflammatory cytokine gene expression.

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Independent Regulation of Endothelial Nitric Oxide Synthase by Src and Protein Kinase A in Mouse Aorta Endothelial Cells

  • Boo, Yong-Chool
    • Journal of Applied Biological Chemistry
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    • v.48 no.3
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    • pp.120-126
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    • 2005
  • Endothelial nitric oxide synthase (eNOS) plays a critical role in vascular biology and pathophysiology. Its activity is regulated by multiple mechanisms such as calcium/calmodulin, protein-protein interactions, sub-cellular locations and phosphorylation at various sites. Phosphorylation of eNOS-Ser1177 (based on mouse sequence) has been identified as an important mechanism of eNOS activation. However, signaling pathway leading to it phosphorylation remains controversial. The regulation of eNOS-Ser1177 phosphorylation by Src and protein kinase A (PKA) was investigated in the present study using cultured mouse aorta endothelial cells. Expression of a constitutively active Src mutant in the cells enhanced phosphorylation of eNOS and protein kinase B (Akt). The Src-stimulated phosphorylation was not attenuated by the expression of a dominant negative PKA regulatory subunit. Neither activation nor inhibition of PKA activity had any significant effect on tyrosine phosphorylation of activation or inactivation site in Src. Based on the results of this study, it is suggested that Src/Akt pathway and PKA signaling may regulate eNOS phosphorylation independently. The existence of multiple mechanisms for eNOS phosphorylation may guarantee endothelial nitric oxide production in various cellular contexts which is essential for maintenance of vascular health.

Mechanistic insights into differential requirement of receptor dimerization for oncogenic activation of mutant EGFR and its clinical perspective

  • Cho, Jeonghee
    • BMB Reports
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    • v.53 no.3
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    • pp.133-141
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    • 2020
  • The epidermal growth factor receptor (EGFR), a member of the ErbB family (EGFR, ErbB2, ErbB3 and ErbB4), plays a crucial role in regulating various cellular responses such as proliferation, differentiation, and survival. As a result, aberrant activation of EGFR, mostly mediated through different classes of genomic alterations occurring within EGFR, is closely associated with the pathogenesis of numerous human cancers including lung adenocarcinoma, glioblastoma, and colorectal cancer. Thus, specific suppression of oncogenic activity of mutant EGFR with its targeted drugs has been routinely used in the clinic as a very effective anti-cancer strategy in treating a subset of tumors driven by such oncogenic EGFR mutants. However, the clinical efficacy of EGFR-targeted therapy does not last long due to several resistance mechanisms that emerge in the patients following the drug treatment. Thus, there is an urgent need for the development of novel therapeutic tactics specifically targeting mutant EGFR with the focus on the unique biological features of various mutant EGFR. Regarding this point, our review specifically emphasizes the recent findings about distinct requirements of receptor dimerization and autophosphorylation, which are critical steps for enzymatic activation of EGFR and signaling cascades, respectively, among wildtype and mutant EGFR and further discuss their clinical significance. In addition, the molecular mechanisms regulating EGFR dimerization and enzymatic activity by a key negative feedback inhibitor Mig6 as well as the clinical use for developing potential novel drugs targeting it are described in this review.

Oak Wood Vinegar Suppresses the Expression of Cyclooxygenase-2 Induced by TLR4 Agonist

  • Yun, Sae-Mi;Park, Se-Jeong;Lee, A-Neum;Ahn, Sang-Il;Youn, Hyung-Sun
    • Biomedical Science Letters
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    • v.15 no.3
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    • pp.257-260
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    • 2009
  • Toll-like receptors (TLRs) recognize molecular structures derived from microbes including bacteria, viruses, yeast, and fungi. TLRs have emerged as a major signaling component of the mammalian host defense. TLR4 is a member of the Toll family that senses lipopolysaccharide (LPS), a cell wall component of gram negative bacteria. LPS recognition by TLR4 requires an additional accessory molecule, MD-2. LPS induces the activation of NF-${\kappa}B$ and IRF3 through MyD88 or TRIF-dependent pathways. The activation of NF-${\kappa}B$ leads to the induction of inflammatory gene products including cytokines and cyclooxygenase-2 (COX-2). This study was carried out to investigate the anti-inflammatory effects of oak wood vinegar. Oak wood vinegar inhibits the NF-${\kappa}B$ activation and COX-2 expression induced by LPS. These results provide new ideas to understand the mechanism of oak wood vinegar for its anti-bacterial and anti-inflammatory activities.

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