100 research outputs found

    Translation Representations and Scattering By Two Intervals

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    Studying unitary one-parameter groups in Hilbert space (U(t),H), we show that a model for obstacle scattering can be built, up to unitary equivalence, with the use of translation representations for L2-functions in the complement of two finite and disjoint intervals. The model encompasses a family of systems (U (t), H). For each, we obtain a detailed spectral representation, and we compute the scattering operator, and scattering matrix. We illustrate our results in the Lax-Phillips model where (U (t), H) represents an acoustic wave equation in an exterior domain; and in quantum tunneling for dynamics of quantum states

    Fixed points for cyclic R-contractions and solution of nonlinear Volterra integro-differential equations

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    In this paper, we introduce the notion of cyclic R-contraction mapping and then study the existence of fixed points for such mappings in the framework of metric spaces. Examples and application are presented to support the main result. Our result unify, complement, and generalize various comparable results in the existing literature.http://link.springer.com/journal/11784am2016Mathematics and Applied Mathematic

    The clinical significance of tumor infiltrating lymphoctyes in breast cancer: does subtype matter?

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    Tumor infiltrating lymphocytes (TILs) are commonly detected in breast tumors but their bearing on disease outcome is uncertain. The importance of TILs appears to be subtype-specific and varies depending on the histologic characteristics of the tumor. As our understanding of tumorigenesis is increasing the relevance of immunobiology will become apparent

    Selective in vitro and in silico butyrylcholinesterase inhibitory activity of diterpenes and rosmarinic acid isolated from Perovskia atriplicifolia Benth. and Salvia glutinosa L.

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    Cholinesterase inhibition is one of the most treatment strategies against Alzheimer's disease (AD) where metal accumulation is also strongly associated with pathology of the disease. In the current study, we assessed inhibitory effect against acetyl- (AChE) and butyrylcholinesterase (BChE) and metal-chelating capacity of twelve diterpenes: arucadiol, miltirone, tanshinone IIa, 1-oxomiltirone, cryptotanshinone, 1,2-didehydromiltirone, 1,2-didehydrotanshinone IIa, 1b-hydroxycryptotanshinone, 15,16- dihydrotanshinone, tanshinone I, isotanshinone II, 1(S)-hydroxytanshinone IIa, and rosmarinic acid, isolated from Perovskia atriplicifolia and Salvia glutinosa. The compounds were tested at 10 µg/mL using ELISA microtiter assays against AChE and BChE. QSAR and molecular docking studies have been also performed on the active compounds. All of the compounds showed higher [e.g., IC50 = 1.12 ± 0.07 µg/mL for 1,2-didehydromiltirone, IC50 = 1.15 ± 0.07 µg/mL for cryptotanshinone, IC50 = 1.20 ± 0.03 µg/mL for arucadiol, etc.)] or closer [1,2-didehydrotanshinone IIa (IC50 = 5.98 ± 0.49 µg/mL) and 1(S)-hydroxytanshinone IIa (IC50 = 5.71 ± 0.27 µg/mL)] inhibition against BChE as compared to that of galanthamine (IC50 = 12.56 ± 0.37 µg/mL), whereas only 15,16-dihydrotanshinone moderately inhibited AChE (65.17 ± 1.39%). 1,2-Didehydrotanshinone IIa (48.94 ± 0.26%) and 1(S)-hydroxytanshinone IIa (47.18 ± 5.10%) possessed the highest metal-chelation capacity. The present study affords an evidence for the fact that selective BChE inhibitors should be further investigated as promising candidate molecules for AD therapy.Ciencias AmbientalesCiencias de la AlimentaciónFarmaciaIngeniería, Industria y ConstrucciónMedicin

    Loureirin B, an essential component of Sanguis Draxonis, inhibits Kv1.3 channel and suppresses cytokine release from Jurkat T cells

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    Sanguis draxonis (SD), also known as “Dragon’s Blood”, is a traditional herb medicine that has been used to treat a variety of complications with unknown mechanisms. Recent studies show that SD displays immunosuppressive activities and improves symptoms of type I diabetes in animal models. However, the mechanisms underlying SD’s immunosuppressive actions are not completely understood. The voltage-gated Kv1.3 channel plays a critical role in the pathogenesis of autoimmune diseases by regulating the functions of both T cells and B cells. Here we investigated the effect of SD and one of its active components loureirin B (LrB) on Kv1.3. Both SD and LrB inhibited Kv1.3-mediated currents, produced a membrane depolarization, and reduced Ca(2+) influx in Jurkat T cells. In addition, application of LrB inhibited phytohemagglutinin (PHA)-induced IL-2 release from activated Jurkat T cells. Furthermore, point mutations in the selective filter region significantly reduced the inhibitory effect of LrB on Kv1.3. The results of these experiments provide evidence that LrB is a channel blocker of Kv1.3 by interacting with amino acid residues in its selective filter region. Direct inhibition of Kv1.3 in T cells by SD and LrB might be the cellular and molecular basis of SD-mediated immunosuppression

    Tumour-draining axillary lymph nodes in patients with large and locally advanced breast cancers undergoing neoadjuvant chemotherapy (NAC): the crucial contribution of immune cells (effector, regulatory) and cytokines (TH1, TH2) to immune-mediated tumour cell death induced by NAC

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    Background The tumour microenvironment consists of malignant cells, stroma and immune cells. In women with large and locally advanced breast cancers (LLABCs) undergoing neoadjuvant chemotherapy (NAC), tumour-infiltrating lymphocytes (TILs), various subsets (effector, regulatory) and cytokines in the primary tumour play a key role in the induction of tumour cell death and a pathological complete response (pCR) with NAC. Their contribution to a pCR in nodal metastases, however, is poorly studied and was investigated. Methods Axillary lymph nodes (ALNs) (24 with and 9 without metastases) from women with LLABCs undergoing NAC were immunohistochemically assessed for TILs, T effector and regulatory cell subsets, NK cells and cytokine expression using labelled antibodies, employing established semi-quantitative methods. IBM SPSS statistical package (21v) was used. Non-parametric (paired and unpaired) statistical analyses were performed. Univariate and multivariate regression analyses were carried out to establish the prediction of a pCR and Spearman’s Correlation Coefficient was used to determine the correlation of immune cell infiltrates in ALN metastatic and primary breast tumours. Results In ALN metastases high levels of TILs, CD4+ and CD8+ T and CD56+ NK cells were significantly associated with pCRs.. Significantly higher levels of Tregs (FOXP3+, CTLA-4+) and CD56+ NK cells were documented in ALN metastases than in the corresponding primary breast tumours. CD8+ T and CD56+ NK cells showed a positive correlation between metastatic and primary tumours. A high % CD8+ and low % FOXP3+ T cells and high CD8+: FOXP3+ ratio in metastatic ALNs (tumour-free para-cortex) were associated with pCRs. Metastatic ALNs expressed high IL-10, low IL-2 and IFN-ϒ. Conclusions Our study has provided new data characterising the possible contribution of T effector and regulatory cells and NK cells and T helper1 and 2 cytokines to tumour cell death associated with NAC in ALNs

    Differential pattern and prognostic significance of CD4+, FOXP3+ and IL-17+ tumor infiltrating lymphocytes in ductal and lobular breast cancers

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    <p>Abstract</p> <p>Background</p> <p>Clinical relevance of tumor infiltrating lymphocytes (TILs) in breast cancer is controversial. Here, we used a tumor microarray including a large series of ductal and lobular breast cancers with long term follow up data, to analyze clinical impact of TIL expressing specific phenotypes and distribution of TILs within different tumor compartments and in different histological subtypes.</p> <p>Methods</p> <p>A tissue microarray (TMA) including 894 ductal and 164 lobular breast cancers was stained with antibodies recognizing CD4, FOXP3, and IL-17 by standard immunohistochemical techniques. Lymphocyte counts were correlated with clinico-pathological parameters and survival.</p> <p>Results</p> <p>CD4<sup>+ </sup>lymphocytes were more prevalent than FOXP3<sup>+ </sup>TILs whereas IL-17<sup>+ </sup>TILs were rare. Increased numbers of total CD4<sup>+ </sup>and FOXP3<sup>+ </sup>TIL were observed in ductal, as compared with lobular carcinomas. High grade (G3) and estrogen receptor (ER) negative ductal carcinomas displayed significantly (<it>p </it> < 0.001) higher CD4<sup>+ </sup>and FOXP3<sup>+ </sup>lymphocyte infiltration while her2/neu over-expression in ductal carcinomas was significantly (<it>p </it> < 0.001) associated with higher FOXP3<sup>+ </sup>TIL counts. In contrast, lymphocyte infiltration was not linked to any clinico-pathological parameters in lobular cancers. In univariate but not in multivariate analysis CD4<sup>+ </sup>infiltration was associated with significantly shorter survival in patients bearing ductal, but not lobular cancers. However, a FOXP3<sup>+</sup>/CD4<sup>+ </sup>ratio > 1 was associated with improved overall survival even in multivariate analysis (<it>p </it>= 0.033).</p> <p>Conclusions</p> <p>Ductal and lobular breast cancers appear to be infiltrated by different lymphocyte subpopulations. In ductal cancers increased CD4<sup>+ </sup>and FOXP3<sup>+ </sup>TIL numbers are associated with more aggressive tumor features. In survival analysis, absolute numbers of TILs do not represent major prognostic indicators in ductal and lobular breast cancer. Remarkably however, a ratio > 1 of total FOXP3<sup>+</sup>/CD4<sup>+ </sup>TILs in ductal carcinoma appears to represent an independent favorable prognostic factor.</p
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