1,028 research outputs found

    食管癌原發灶與淋巴結轉移灶細胞染色體變化特征的比較

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    BACKGROUND & OBJECTIVE: Local lymph node and blood metastasis could occur at early stage of esophageal squamous cell carcinoma (ESCC), which may be the key factors of its recurrence and poor prognosis. However, the mechanism of ESCC metastasis is unclear. This study was to analyze the genetic changes in primary lesion and lymph node metastases of ESCC, to screen for and locate ESCC metastasis-related genes. METHODS: Genomic alterations in 15 pairs of primary lesions and matched metastatic lymph nodes of ESCC were analyzed by comparative genomic hybridization (CGH). RESULTS: In the 15 pairs of tissues, the most common chromosomal alterations were the gains of 3q, 8q, 6p, 20p, 5p, 18p, 2p, 2q and 1q, and the losses of 10p, 10q, 17p, 18q, 4p and 13q. Of these changes, the most significant finding was the gain of 6p with a frequency of 47% in metastatic lymph nodes and 13% in primary lesions, and the gain of 20p with a frequency of 73% in metastatic lymph nodes and 33% in primary lesions. The second interesting finding was the loss of 10p with a frequency of 53% in metastatic lymph nodes and 13% in primary lesions, and the loss of 10q with a frequency of 47% in metastatic lymph nodes and 13% in primary lesions. CONCLUSION: The gains of 6p and 20p and the losses of 10p and 10q are common genomic alterations in primary lesion and lymph node metastases of ESCC, which may code ESCC metastasis-related genes.背景與目的:食管癌早期可發生局部淋巴或血行轉移,這是導致復發和預后差的主要原因。但是,食管癌轉移發生的分子機制尚不清楚。本研究旨在分析食管癌原發灶和淋巴結轉移灶腫瘤細胞染色體變化的特征,尋找或定位與食管癌轉移相關基因,加深對其轉移機制的了解。方法:應用比較基因組雜交技術(comparativegenomichybridization,CGH)分析15例食管癌患者原發灶和其對應的淋巴結轉移灶的染色體基因組改變。結果:最常見染色體DNA拷貝數增加的部位是3q,8q,6p,20p,5p,18p,2p,2q,1q;常見的染色體DNA拷貝數丟失的部位是10p,10q,17p,18q,4p,13q。其中,最有意義的發現是6p增加(原發灶:2/15,13%,轉移灶:7/15,47%),20p增加(原發灶:5/15,33.3%,轉移灶:11/15,73.3%)。第二個發現是10p丟失(原發灶:2/15,13.3%,轉移灶:8/15,53%),10q丟失(原發灶:2/15,13.3%,轉移灶:7/15,46.6%)。結論:食管癌原發灶和淋巴結轉移灶細胞染色體基因組改變最顯著的部位是6p,20p的增加和10p,10q的丟失;這些部位可能存在與食管癌細胞淋巴結轉移相關的基因。link_to_subscribed_fulltex

    Transition from steady to oscillatory convection with chaotic feature in thermocapillary convection

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    The transition process from steady to turbulent convection via subharmonic bifurcation in thermocapillary convection of half floating zone was studied by numerical simulation and experimental test. Both approaches gave structure of period doubling bifurcations in the present paper, and the Feigenbaum universal law was checked for the system of thermocapillary convection

    Signal pathways underlying homocysteine-induced production of MCP-1 and IL-8 in cultured human whole blood

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    Aim : To elucidate the mechanisms underlying homocysteine (Hcy)-induced chemokine production. Methods : Human whole blood was pretreated with inhibitors of calmodulin (CaM), protein kinase C (PKC), protein tyrosine kinase (PTK), mitogen-activated protein kinase (MAPK), and NF-ΚB and activators of PPARΓ for 60 min followed by incubation with Hcy 100 Μmol/L for 32 h. The levels of mitogen chemokine protein (MCP)-1 and interleukin-8 (IL-8) were determined by enzyme-linked immunosorbant assay (ELISA). Results : Inhibitors of PKC (calphostin C, 50-500 nmol/L and RO-31-8220, 10–100 nmol/L), CaM (W7, 28–280 Μmol/L), ERK1/2 MAPK (PD 98059, 2–20 Μmol/L), p38 MAPK (SB 203580, 0.6–6 Μmol/L), JNK MAPK (curcumin, 2–10 Μmol/L), and NF-ΚB (PDTC, 10-100 nmol/L) markedly reduced Hcy 100 Μmol/L-induced production of MCP-1 and IL-8 in human cultured whole blood, but the inhibitors of PTK (genistein, 2.6–26 Μmol/L and tyrphostin, 0.5-5 Μmol/L) had no obvious effect on MCP-1 and IL-8 production. PPARΓ activators (ciglitazone 30 Μmol/L and troglitazone 10 Μmol/L) depressed the Hcy-induced MCP-1 production but not IL-8 production in the cultured whole blood. Conclusion : Hcy-induced MCP-1 and IL-8 production is mediated by activated signaling pathways such as PKC, CaM, MAPK, and NF-ΚB. Our results not only provide clues for the signal transduction pathways mediating Hcy-induced chemokine production, but also offer a plausible explanation for a pathogenic role of hyperhomocysteinemia in these diseases.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75644/1/j.1745-7254.2005.00005.x.pd

    Maize ABP9 enhances tolerance to multiple stresses in transgenic Arabidopsis by modulating ABA signaling and cellular levels of reactive oxygen species

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    The phytohormone abscisic acid (ABA) and reactive oxygen species (ROS) play critical roles in mediating abiotic stress responses in plants. It is well known that ABA is involved in the modulation of ROS levels by regulating ROS-producing and ROS-scavenging genes, but the molecular mechanisms underlying this regulation are poorly understood. Here we show that the expression of maize ABP9 gene, which encodes a bZIP transcription factor capable of binding to the ABRE2 motif in the maize Cat1 promoter, is induced by ABA, H2O2, drought and salt. Constitutive expression of ABP9 in transgenic Arabidopsis leads to remarkably enhanced tolerance to multiple stresses including drought, high salt, freezing temperature and oxidative stresses. ABP9 expressing Arabidopsis plants also exhibit increased sensitivity to exogenously applied ABA during seed germination, root growth and stomatal closure and improved water-conserving capacity. Moreover, constitutive expression of ABP9 causes reduced cellular levels of ROS, alleviated oxidative damage and reduced cell death, accompanied by elevated expression of many stress/ABA responsive genes including those for scavenging and regulating ROS. Taken together, these results suggest that ABP9 may play a pivotal role in plant tolerance to abiotic stresses by fine tuning ABA signaling and control of ROS accumulation

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

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    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at √s=8TeV

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    The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fb−1of data collected in proton–proton collisions at √s=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV

    Differential expression of microRNAs during fiber development between fuzzless- lintless mutant and its wild-type allotetraploid cotton

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    Cotton is one of the most important textile crops but little is known how microRNAs regulate cotton fiber development. Using a well-studied cotton fiberless mutant Xu-142-fl, we compared 54 miRNAs for their expression between fiberless mutant and its wildtype. In wildtype Xu-142, 26 miRNAs are involved in cotton fiber initiation and 48 miRNAs are related to primary wall synthesis and secondary wall thickening. Thirty three miRNAs showed different expression in fiber initiation between Xu-142 and Xu- 142-fl. These miRNAs potentially target 723 protein-coding genes, including transcription factors, such as MYB, ARF, and LRR. ARF18 was newly predicted targets of miR160a, and miR160a was expressed at higher level in −2DPA of Xu-142-fl compared with Xu-142. Furthermore, the result of Gene Ontology- based term classification (GO), EuKaryotic Orthologous Groups (KOG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis shows that miRNA targets were classified to 222 biological processes, 64 cellular component and 42 molecular functions, enriched in 22 KOG groups, and classified into 28 pathways. Together, our study provides evidence for better understanding of miRNA regulatory roles in the process of fiber development, which is helpful to increase fiber yield and improve fiber quality

    MicroRNA expression profiles during cotton (Gossypium hirsutum L) fiber early development

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    The role of microRNAs (miRNAs) during cotton fiber development remains unclear. Here, a total of 54 miRNAs belonging to 39 families were selected to characterize miRNA regulatory mechanism in eight different fiber development stages in upland cotton cv BM-1. Among 54 miRNAs, 18 miRNAs were involved in cotton fiber initiation and eight miRNAs were related to fiber elongation and secondary wall biosynthesis. Additionally, 3,576 protein-coding genes were candidate target genes of these miRNAs, which are potentially involved in cotton fiber development. We also investigated the regulatory network of miRNAs and corresponding targets in fiber initiation and elongation, and secondary wall formation. Our Gene Ontology-based term classification and KEGG-based pathway enrichment analyses showed that the miRNA targets covered 220 biological processes, 67 molecular functions, 45 cellular components, and 10 KEGG pathways. Three of ten KEGG pathways were involved in lignan synthesis, cell elongation, and fatty acid biosynthesis, all of which have important roles in fiber development. Overall, our study shows the potential regulatory roles of miRNAs in cotton fiber development and the importance of miRNAs in regulating different cell types. This is helpful to design miRNA-based biotechnology for improving fiber quality and yield
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