44 research outputs found

    Expression of matrix metalloproteinase-9 in the neoplastic and interstitial inflammatory infiltrate cells in gastric cancer.

    Get PDF
    Matrix metalloproteinases (MMPs) play an important role in the extracellular matrix degradation, that is an essential step in tumor invasion and metastases. The current study objective was to evaluate the expression of MMP-9 in the neoplastic and in the interstitial inflammatory infiltrate cells in gastric cancer (GC). Moreover, the relationship between expression of this enzyme and clinicopathological features of GC, such as TNM stage, the depth of tumor invasion, lymph node and distant metastases were assessed. The study comprised 54 patients with gastric cancer. Immunohistochemistry was used to determine the expression of MMP-9 in gastric cancer cells. The semi-quantitative scale was applied to evaluate the expression of metalloproteinase-9. Immunohistochemical testing revealed a positive reaction of MMP-9 in 98% of all cancer tissue specimens and in 93% of inflammatory cells. The expression of MMP-9 in the neoplastic and inflammatory cells increased with more advance tumor stage, depth of tumor invasion and presence of lymph node as well as distant metastases. These findings indicate the significance of interstitial inflammatory infiltrate cells in the MMP-9 synthesis and the role of this enzyme in the invasiveness and metastatic potential of GC

    Expression of tissue inhibitors of metalloproteinase 1 (TIMP-1) in gastric cancer tissue.

    Get PDF
    Degradation of extracellular matrix (ECM) is an essential step of invasion and metastasis of gastric cancer. The proteolysis of basement membranes depends on the balance between activities of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). The aim of the study was to assess the expression of TIMP-1 in gastric cancer (GC) and interstitial inflammatory infiltrate cells within GC tissue in relation to clinico-pathological features of tumor and to estimate the prognostic significance of TIMP-1 expression for patients' survival. The presence of TIMP-1 in 54 cases of gastric cancer samples was investigated by immunohistochemistry. The expression of TIMP-1 in cancer and interstitial inflammatory infiltrate cells was evaluated in semi-quantitative scale. The immunoreactivity of TIMP-1 in cancer and inflammatory cells was positive in 100% of cases and varied from weak to intense reaction. The intensity of TIMP-1 expression increased with more advanced tumor stages and in patients who died of cancer during 2-year observation. TIMP-1 expression in interstitial inflammatory infiltrate cells was the independent prognostic factor for patients' survival. The results suggest the role of TIMP-1 in gastric tumorigenesis, although this issue requires further investigtions

    Alkali metal distribution in composite cement pastes and its relation to accelerated ASR tests

    Get PDF
    Accelerated testing of alkali silica reaction (ASR) in concrete at elevated temperatures of 38 and 60 °C has an unknown impact on the alkali metal distribution in the cement paste. This paper investigates how the alkali metals released from hydrating Portland cement, limestone, and SCMs distribute between non-reactive and unreacted phases, C-A-S-H, and the pore solution. The SCMs investigated were fly ash and a volcanic pozzolan. The hydrate assemblage and pore solution of cement pastes cured at 20, 38 and 60 °C were analysed and related to the expansion of concrete prisms. There is little difference in alkali metal distribution at 20 and 38 °C, whereas curing at 60 °C has a large impact for the SCM containing blends. At alkali metal concentrations in the pore solution below 0.5 mol/L (Na + K) expansion of concrete was suppressed. Pore solution analysis could be used to screen new SCMs for ASR mitigation.publishedVersio

    Influence of limestone on the hydration of ternary slag cement

    Get PDF
    The hydration kinetics, microstructure and pore solution composition of ternary slag-limestone cements have been investigated. Commercial CEM I 52.5 R was blended with slag and limestone; maintaining a clinker to SCM ratio of 50:50 with up to 20% slag replaced by limestone. The sulphate content was maintained at 3% in all composite systems. Hydration was followed by a combination of isothermal calorimetry, chemical shrinkage, scanning electron microscopy, and thermogravimetric analysis. The hydration of slag was followed by the implementation of QXRD/PONKCS method. The accuracy of the calibrated PONKCS phase was assessed on slag and corundum mixes of varying ratios, at different w/s ratios. Thus, the method was used to analyse hydrated cements without dehydrating the specimens. The results show that the presence of limestone enhanced both clinker and slag hydration. The pore volume and pore solution chemistry were further examined to clarify to the synergistic effects. The nucleation effects account for enhanced clinker hydration while the space available for hydrate growth plus lowering of the aluminium concentration in the pore solution led to the improved slag hydration

    Reactivity tests for supplementary cementitious materials: RILEM TC 267-TRM phase 1

    Get PDF
    A primary aim of RILEM TC 267-TRM: “Tests for Reactivity of Supplementary Cementitious Materials (SCMs)” is to compare and evaluate the performance of conventional and novel SCM reactivity test methods across a wide range of SCMs. To this purpose, a round robin campaign was organized to investigate 10 different tests for reactivity and 11 SCMs covering the main classes of materials in use, such as granulated blast furnace slag, fly ash, natural pozzolan and calcined clays. The methods were evaluated based on the correlation to the 28 days relative compressive strength of standard mortar bars containing 30% of SCM as cement replacement and the interlaboratory reproducibility of the test results. It was found that only a few test methods showed acceptable correlation to the 28 days relative strength over the whole range of SCMs. The methods that showed the best reproducibility and gave good correlations used the R3 model system of the SCM and Ca(OH)2, supplemented with alkali sulfate/carbonate. The use of this simplified model system isolates the reaction of the SCM and the reactivity can be easily quantified from the heat release or bound water content. Later age (90 days) strength results also correlated well with the results of the IS 1727 (Indian standard) reactivity test, an accelerated strength test using an SCM/Ca(OH)2-based model system. The current standardized tests did not show acceptable correlations across all SCMs, although they performed better when latently hydraulic materials (blast furnace slag) were excluded. However, the Frattini test, Chapelle and modified Chapelle test showed poor interlaboratory reproducibility, demonstrating experimental difficulties. The TC 267-TRM will pursue the development of test protocols based on the R3 model systems. Acceleration and improvement of the reproducibility of the IS 1727 test will be attempted as well

    Identification and Visualization of CD8+ T Cell Mediated IFN-Îł Signaling in Target Cells during an Antiviral Immune Response in the Brain

    Get PDF
    CD8+ T cells infiltrate the brain during an anti-viral immune response. Within the brain CD8+ T cells recognize cells expressing target antigens, become activated, and secrete IFNÎł. However, there are no methods to recognize individual cells that respond to IFNÎł. Using a model that studies the effects of the systemic anti-adenoviral immune response upon brain cells infected with an adenoviral vector in mice, we describe a method that identifies individual cells that respond to IFNÎł. To identify individual mouse brain cells that respond to IFNÎł we constructed a series of adenoviral vectors that contain a transcriptional response element that is selectively activated by IFNÎł signaling, the gamma-activated site (GAS) promoter element; the GAS element drives expression of a transgene, Cre recombinase (Ad-GAS-Cre). Upon binding of IFNÎł to its receptor, the intracellular signaling cascade activates the GAS promoter, which drives expression of the transgene Cre recombinase. We demonstrate that upon activation of a systemic immune response against adenovirus, CD8+ T cells infiltrate the brain, interact with target cells, and cause an increase in the number of cells expressing Cre recombinase. This method can be used to identify, study, and eventually determine the long term fate of infected brain cells that are specifically targeted by IFNÎł. The significance of this method is that it will allow to characterize the networks in the brain that respond to the specific secretion of IFNÎł by anti-viral CD8+ T cells that infiltrate the brain. This will allow novel insights into the cellular and molecular responses underlying brain immune responses
    corecore