• Title/Summary/Keyword: EphA

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Erythropoietin-producing Human Hepatocellular Carcinoma Receptor B1 Polymorphisms are Associated with HBV-infected Chronic Liver Disease and Hepatocellular Carcinoma in a Korean Population

  • Kim, Kyoung-Yeon;Lee, Seung-Ku;Kim, Min-Ho;Cheong, Jae-Youn;Cho, Sung-Won;Yang, Kap-Seok;Kwack, Kyu-Bum
    • Genomics & Informatics
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    • v.6 no.4
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    • pp.192-201
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    • 2008
  • Erythropoietin-producing human hepatocellular carcinoma receptor B1 (EPHB1) is a member of the Eph family of receptor tyrosine kinases that mediate vascular system development. Eph receptor overexpression has been observed in various cancers and is related to the malignant transformation, metastasis, and differentiation of cancers, including hepatocellular carcinoma (HCC). Eph receptors regulate cell migration and attachment to the extracellular matrix by modulating integrin activity. EphrinB1, the ligand of EPHB1, has been shown to regulate HCC carcinogenesis. Here, we sought to determine whether EPHB1 polymorphisms are associated with hepatitis B virus (HBV)-infected liver diseases, including chronic liver disease (CLD) and HCC. We genotyped 26 EPHB1 single nucleotide polymorphisms (SNPs) in 399 Korean CLD, HCC, and LD (CLD+HCC) cases and seroconverted controls (HBV clearance, CLE) using the GoldenGate assay. Two SNPs (rs6793828 and rs11717042) and 1 haplotype that were composed of these SNPs were associated with an increased risk for CLD, HCC, and LD (CLD+HCC) compared with CLE. Haplotypes that could be associated with HBV-infected liver diseases by affecting downstream signaling were located in the Eph tyrosine kinase domain of EPHB1. Therefore, we suggest that EPHB1 SNPs, haplotypes, and diplotypes may be genetic markers for the progression of HBV-associated acute hepatitis to CLD and HCC.

Earthquake effects on the energy demand of tall reinforced concrete walls with buckling-restrained brace outriggers

  • Beiraghi, Hamid
    • Structural Engineering and Mechanics
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    • v.63 no.4
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    • pp.521-536
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    • 2017
  • Reinforced concrete core-wall structures with buckling-restrained brace outriggers are interesting systems which have the ability to absorb and dissipate energy during strong earthquakes. Outriggers can change the energy demand in a tall building. In this paper, the energy demand was studied by using the nonlinear time history analysis for the mentioned systems. First, the structures were designed according to the prescriptive codes. In the dynamic analysis, three approaches for the core-wall were investigated: single plastic hinge (SPH), three plastic hinge (TPH) and extended plastic hinge (EPH). For SPH approach, only one plastic hinge is allowed at the core-wall base. For TPH approach, three plastic hinges are allowed, one at the base and two others at the upper levels. For EPH approach, the plasticity can extend anywhere in the wall. The kinetic, elastic strain, inelastic and damping energy demand subjected to forward directivity near-fault and ordinary far-fault earthquakes were studied. In SPH approach for all near-fault and far-fault events, on average, more than 65 percent of inelastic energy is absorbed by buckling-restrained braces in outrigger. While in TPH and EPH approaches, outrigger contribution to inelastic energy demand is reduced. The contribution of outrigger to inelastic energy absorption for the TPH and EPH approaches does not differ significantly. The values are approximately 25 and 30 percent, respectively.

In Vivo Expression of EphrinA5-Fc in Mice Results in Cephalic Neural Crest Agenesis and Craniofacial Abnormalities

  • Noh, Hyuna;Park, Eunjeong;Park, Soochul
    • Molecules and Cells
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    • v.37 no.1
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    • pp.59-65
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    • 2014
  • Eph receptors and their ligands ephrins have been implicated in guiding the directed migration of neural crest cells (NCCs). In this study, we found that Wnt1-Cre-mediated expression of ephrinA5-Fc along the dorsal midline of the dien- and mesencephalon resulted in severe craniofacial malformation of mouse embryo. Interestingly, expression of cephalic NCC markers decreased significantly in the frontonasal process and branchial arches 1 and 2, which are target areas for the migratory cephalic NCCs originating in the dien- and mesencephalon. In addition, these craniofacial tissues were much smaller in mutant embryos expressing ephrinA5-Fc. Importantly, EphA7-positive cephalic NCCs were absent along the dorsal dien- and mesencephalon of mutant embryos expressing ephrinA5-Fc, suggesting that the generation of cephalic NCCs is disrupted due to ephrinA5-Fc expression. NCC explant experiments suggested that ephrinA5-Fc perturbed survival of cephalic NCC precursors in the dorsal midline tissue rather than affecting their migratory capacity, which was consistent with our previous report that expression of ephrinA5-Fc in the dorsal midline is responsible for severe neuroepithelial cell apoptotic death. Taken together, our findings strongly suggest that expression of ephrinA5-Fc decreases a population of cephalic NCC precursors in the dorsal midline of the dien- and mesencephalon, thereby disrupting craniofacial development in the mouse embryos.

Energy demands in reinforced concrete wall piers coupled by buckling restrained braces subjected to near-fault earthquake

  • Beiraghi, Hamid
    • Steel and Composite Structures
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    • v.27 no.6
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    • pp.703-716
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    • 2018
  • In this study, the different energy demands in reinforced concrete (RC) wall piers, coupled by buckling restrained braces (BRBs), are investigated. As well as this, a single plastic hinge approach (SPH) and an extended plastic hinge (EPH) approach is considered for the wall piers. In the SPH approach, plasticity can extend only in the 0.1H adjacent to the wall base while, in the EPH approach, the plasticity can extend anywhere in the wall. The seismic behavior of 10-, 20- and 30-storey structures, subjected to near-fault (NF) as well as far-fault (FF) earthquakes, is studied with respect to the energy concepts involved in each storey. Different kinds of energy, including inelastic, damping, kinetic, elastic and total input energy demand, are investigated. The energy contribution from the wall piers, as well as the BRBs in each model, are studied. On average, for EPH approach, the inelastic demand portion pertaining to the BRBs for NF and FF records, is more than 60 and 80%, respectively. In the SPH approach, these ratios are 77 and 90% for the NF and FF events, respectively. It appears that utilizing the BRBs as energy dissipation members between two wall piers is an efficient concept.

Multiple Regulation of Roundabout (Robo) Phosphorylation in a Heterologous Cell System

  • Park, Hwan-Tae
    • The Korean Journal of Physiology and Pharmacology
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    • v.8 no.2
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    • pp.111-115
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    • 2004
  • Roundabout (Robo) is the transmembrane receptor for slit, the neuronal guidance molecule. In this study, the tyrosine phosphorylation of Robo was observed in Robo-transfected human embryonic kidney cells and developing rat brains, and found to be increased by the treatment with protein kinase A activator, forskolin. In contrast, protein kinase C activation by phorbol-12-myristate-13-acetate decreased the phosphorylation of Robo. Intracellular calcium was required for the tyrosine phosphorylation. Furthermore, the transfection of an Eph receptor tyrosine kinase dramatically enhanced the tyrosine phosphorylation. These findings indicate that the tyrosine phosphorylation of Robo is regulated by multiple mechanisms, and that Eph receptor kinases may play a role in the regulation of tyrosine phosphorylation of Robo in the rat brain.

Study on the Soil Sample Number of Total Petroleum Hydrocarbons Fractionation for Risk Assessment in Contaminated Site (석유계총탄화수소의 위해성평가 시 적정 분획 시료수 결정에 대한 고찰)

  • Jeon, Inhyeong;Kim, Sang Hyun;Chung, Hyeonyong;Jeong, Buyun;Noh, Hoe-Jung;Kim, Hyun-Koo;Nam, Kyoungphile
    • Journal of Soil and Groundwater Environment
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    • v.24 no.5
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    • pp.11-16
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    • 2019
  • In this study, a reliable number of soil samples for TPH fractionation was investigated in order to perform risk assessment. TPH was fractionated into volatile petroleum hydrocarbons (VPH) with three subgroups and extractable petroleum hydrocarbons (EPH) with four subgroups. At the study site, concentrations of each fraction were determined at 18 sampling points, and the 95% upper confidence limit (UCL) value was used as an exposure concentration of each fraction. And then, 5 sampling points were randomly selected out of the 18 points, and an exposure concentration was calculated. This process was repeated 30 times, and the results were compared statistically. Exposure concentrations of EPH obtained from 18 points were 99.9, 339.1, 27.3, and 85.9 mg/kg for aliphatic $C_9-C_{18}$, $C_{19}-C_{36}$, $C_{37}-C_{40}$, and aromatic $C_{11}-C_{22}$, respectively. The corresponding exposure concentrations obtained from 5 points were 139.8, 462.8, 35.1 and 119.4 mg/kg, which were significantly higher than those from 18 points results (p <0.05). Our results suggest that limited number of samples for TPH fractionation may bias estimation of exposure concentration of TPH fractions. Also, it is recommended that more than 30 samples need to be analyzed for TPH fractionation in performing risk assessment.

Relevance of the Watson-Jones anterolateral approach in the management of Pipkin type II fracture-dislocation: a case report and literature review

  • Nazim Sifi;Ryad Bouguenna
    • Journal of Trauma and Injury
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    • v.37 no.2
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    • pp.161-165
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    • 2024
  • Femoral head fractures with associated hip dislocations substantially impact the functional prognosis of the hip joint and present a surgical challenge. The surgeon must select a safe approach that enables osteosynthesis of the fracture while also preserving the vascularization of the femoral head. The optimal surgical approach for these injuries remains a topic of debate. A 44-year-old woman was involved in a road traffic accident, which resulted in a posterior iliac dislocation of the hip associated with a Pipkin type II fracture of the femoral head. Given the size of the detached fragment and the risk of incarceration preventing reduction, we opted against attempting external orthopedic reduction maneuvers. Instead, we chose to perform open reduction and internal fixation using the Watson-Jones anterolateral approach. This involved navigating between the retracted tensor fascia lata muscle, positioned medially, and the gluteus medius and minimus muscles, situated laterally. During radiological and clinical follow-up visits extending to postoperative month 15, the patient showed no signs of avascular necrosis of the femoral head, progression toward coxarthrosis, or heterotopic ossification. The Watson-Jones anterolateral approach is a straightforward intermuscular and internervous surgical procedure. This method provides excellent exposure of the femoral head, preserves its primary vascularization, allows for anterior dislocation, and facilitates the anatomical reduction and fixation of the fracture.

Differential Evolution between Monotocous and Polytocous Species

  • Ahn, Hyeonju;Kim, Kyu-Won;Kim, Hyeon Jeong;Cho, Seoae;Kim, Heebal
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.4
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    • pp.464-470
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    • 2014
  • One of the most important traits for both animal science and livestock production is the number of offspring for a species. This study was performed to identify differentially evolved genes and their distinct functions that influence the number of offspring at birth by comparative analysis of eight monotocous mammals and seven polytocous mammals in a number of scopes: specific amino acid substitution with site-wise adaptive evolution, gene expansion and specific orthologous group. The mutually exclusive amino acid substitution among the 16 mammalian species identified five candidate genes. These genes were both directly and indirectly related to ovulation. Furthermore, in monotocous mammals, the EPH gene family was found to have undergone expansion. Previously, the EPHA4 gene was found to positively affect litter size in pigs and supports the possibility of the EPH gene playing a role in determining the number of offspring per birth. The identified genes in this study offer a basis from which the differences between monotocous and polytocous species can be studied. Furthermore, these genes may harbor some clues to the underlying mechanism, which determines litter size and may prove useful for livestock breeding strategies.

Caspase Cleavage of Receptor Tyrosine Kinases in the Dependence Receptor Family

  • Gyu Hwan Park;Yoo Kyung Kang;Seung-Mann Paek;Chan Young Shin;Sun-Young Han
    • Biomolecules & Therapeutics
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    • v.31 no.4
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    • pp.359-369
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    • 2023
  • Dependence receptors are a group of receptor proteins with shared characteristics of transducing two different signals within cells. They can transduce a positive signal of survival and differentiation in the presence of ligands. On the other hand, dependence receptors can transduce an apoptosis signal in the absence of ligands. The function of these receptors depends on the availability of their ligands. Several receptor tyrosine kinases (RTKs) have been reported as dependence receptors. When cells undergo apoptosis by dependence receptors, the intracellular domain of some RTKs is cleaved by the caspases. Among the RTKs that belong to dependence receptors, we focused on eight RTKs (RET, HER2, MET, ALK, TrkC, EphA4, EphB3, and c-KIT) that are cleaved by caspases. In this review, we describe the features of the receptors, their cleavage sites, and the fate of the cleaved products, as well as recent implications on them being used as potential therapeutics for cancer treatment.

Increased Expression of P2RY2, CD248 and EphB1 in Gastric Cancers from Chilean Patients

  • Aquea, Gisela;Bresky, Gustavo;Lancellotti, Domingo;Madariaga, Juan Andres;Zaffiri, Vittorio;Urzua, Ulises;Haberle, Sergio;Bernal, Giuliano
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.1931-1936
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    • 2014
  • Background: Gastric cancer (GC) ranks as one of the major causes of mortality due to cancer worldwide. In Chile, it is currently the leading cause of cancer death. Identification of novel molecular markers that may help to improve disease diagnosis at early stages is imperative. Materials and Methods: Using whole-genome DNA microarrays we determined differential mRNA levels in fresh human GC samples compared to adjacent healthy mucosa from the same patients. Genes significantly overexpressed in GC were validated by RT-PCR in a group of 14 GC cases. Results: The genes CD248, NSD1, RAB17, ABCG8, Ephb1 and P2RY2 were detected as the top overexpressed in GC biopsies. P2RY2, Ephb1 and CD248 showed the best sensitivity for GC detection with values of 92.9%, 85.7% and 64.3% (p<0.05), respectively. Specificity was 85.7%, 71.4% and 71.4% (p<0.05), for each respectively.