Let
C
be a nonempty, closed and convex subset of a real Hilbert space
H
. Let
T
i
:
C
→
H
,
i
=
1
,
2
,
…
,
N
, be a finite family of generalized asymptotically nonexpansive mappings. It is our ...purpose, in this paper to prove strong convergence of Mann’s type method to a common fixed point of
{
T
i
:
i
=
1
,
2
,
…
,
N
}
provided that the interior of common fixed points is nonempty. No compactness assumption is imposed either on
T
or on
C
. As a consequence, it is proved that Mann’s method converges for a fixed point of nonexpansive mapping provided that interior of
F
(
T
)
≠
0̸
. The results obtained in this paper improve most of the results that have been proved for this class of nonlinear mappings.
Metastasis is the primary cause of cancer death. The inflammatory tumor microenvironment contributes to metastasis, for instance, by recruiting blood and lymph vessels. Among tumor-infiltrating ...immune cells, tumor-associated macrophages (TAMs) take a center stage in promoting both tumor angiogenesis and metastatic spread. We found that genetic deletion of the S1P receptor 1 (
) alone in CD11b
CD206
TAMs infiltrating mouse breast tumors prevents pulmonary metastasis and tumor lymphangiogenesis. Reduced lymphangiogenesis was also observed in the nonrelated methylcholanthrene-induced fibrosarcoma model. Transcriptome analysis of isolated TAMs from both entities revealed reduced expression of the inflammasome component
in S1PR1-deficient TAMs. Macrophage-dependent lymphangiogenesis in vitro was triggered upon inflammasome activation and required both S1PR1 signaling and IL-1β production. Finally, NLRP3 expression in tumor-infiltrating macrophages correlated with survival, lymph node invasion, and metastasis of mammary carcinoma patients. Conceptually, our study indicates an unappreciated role of the NLRP3 inflammasome in promoting metastasis via the lymphatics downstream of S1PR1 signaling in macrophages.
In 2012, Samet, Vetro and Vetro introduced
α
-
ψ
-contractive mappings and gave some results on a fixed point of the mappings (Samet et al. in Nonlinear Anal. 75:2154-2165, 2012). In fact, their ...technique generalized some ordered fixed point results (see (Alikhani et al. in Filomat, 2012, to appear) and (Samet et al. in Nonlinear Anal. 75:2154-2165, 2012)). By using the main idea of (Samet et al. in Nonlinear Anal. 75:2154-2165, 2012), we give some new results for
α
-
ψ
-Ciric generalized multifunctions and some related self-maps. Also, we give an affirmative answer to a recent open problem which was raised by Haghi, Rezapour and Shahzad in 2012.
Mucosal inflammation in conditions ranging from infective acute enteritis or colitis to inflammatory bowel disease is accompanied by alteration in serotonin (5-hydroxytryptamine 5-HT) content in the ...gut. Recently, we have identified an important role of 5-HT in the pathogenesis of experimental colitis. 5-HT type 7 (5-HT7) receptor is one of the most recently identified members of the 5-HT receptor family, and dendritic cells express this receptor. In this study, we investigated the effect of blocking 5-HT7 receptor signaling in experimental colitis with a view to develop an improved therapeutic strategy in intestinal inflammatory disorders. Colitis was induced with dextran sulfate sodium (DSS) or dinitrobenzene sulfonic acid (DNBS) in mice treated with selective 5-HT7 receptor antagonist SB-269970, as well as in mice lacking 5-HT7 receptor (5-HT7(-/-)) and irradiated wild-type mice reconstituted with bone marrow cells harvested from 5-HT7(-/-) mice. Inhibition of 5-HT7 receptor signaling with SB-269970 ameliorated both acute and chronic colitis induced by DSS. Treatment with SB-269970 resulted in lower clinical disease, histological damage, and proinflammatory cytokine levels compared with vehicle-treated mice post-DSS. Colitis severity was significantly lower in 5-HT7(-/-) mice and in mice reconstituted with bone marrow cells from 5-HT7(-/-) mice compared with control mice after DSS colitis. 5-HT7(-/-) mice also had significantly reduced DNBS-induced colitis. These observations provide us with novel information on the critical role of the 5-HT7 receptor in immune response and inflammation in the gut, and highlight the potential benefit of targeting this receptor to alleviate the severity of intestinal inflammatory disorders such as inflammatory bowel disease.
On fixed points of α-ψ-contractive multifunctions Asl, J Hasanzade; Rezapour, S; Shahzad, N
Fixed point theory and applications (Hindawi Publishing Corporation),
26/11, Letnik:
2012, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Recently Samet, Vetro and Vetro introduced the notion of
α
-
ψ
-contractive type mappings and established some fixed point theorems in complete metric spaces. In this paper, we introduce the notion ...of
α
∗
-
ψ
-contractive multifunctions and give a fixed point result for these multifunctions. We also obtain a fixed point result for self-maps in complete metric spaces satisfying a contractive condition.
Leukocytes and especially macrophages are a major cellular constituent of the tumor mass. The tumor microenvironment not only determines their activity but in turn these cells also contribute to ...tumor initiation and progression. Recent Advances: Proinflammatory stimulated macrophages upregulate inducible nitric oxide synthase (NOS2) and produce high steady-state NO concentrations. NO provokes tumor cell death by initiating apoptosis and/or necrosis. Mechanisms may comprise p53 accumulation, immunestimulatory activities, and an increased efficacy of chemo- and/or radiotherapy. However, the potential cytotoxic activity of macrophages often is compromised in the tumor microenvironment and instead a protumor activity of macrophages dominates. Contributing factors are signals generated by viable and dying tumor cells, attraction and activation of myeloid-derived suppressor cells, and hypoxia. Limited oxygen availability not only attenuates NOS2 activity but also causes accumulation of hypoxia-inducible factors 1 and 2 (HIF-1/HIF-2). Activation of the HIF system is tightly linked to NO formation and affects the expression of macrophage phenotype markers that in turn add to tumor progression.
To make use of the cytotoxic arsenal of activated macrophages directed against tumor cells, it will be critical to understand how, when, and where these innate immune responses are blocked and whether it will be possible to reinstall their full capacity to kill tumor cells.
Low-dose irradiation or proinflammatory activation of macrophages in the tumor microenvironment may open options to boost NOS2 expression and activity and to initiate immunestimulatory features of NO that may help to restrict tumor growth. Antioxid. Redox Signal. 26, 1023-1043.
A pleiotropic signaling lipid, sphingosine-1-phosphate (S1P), has been implicated in various pathophysiological processes supporting tumor growth and metastasis. However, there are only a few ...descriptive studies suggesting a role of S1P in tumor lymphangiogenesis, which is critical for tumor growth and dissemination. Corroborating own data, the literature suggests that apoptotic tumor cell-derived S1P alters the phenotype of tumor-associated macrophages (TAMs) to gain protumor functions. However, mechanistically, the role of TAM-induced lymphangiogenesis has only been poorly described, mostly linked to the production of lymphangiogenic factors such as vascular endothelial growth factor C (VEGF-C) and VEGF-D, or transdifferentiation into lymphatic endothelial cells. Recent findings highlight a rather underappreciated role of S1P in tumor lymphangiogenesis, referring to the production of interleukin-1β (IL-1β) and lipocalin-2 (LCN2) by a tumor-promoting macrophage phenotype. In this review, we aim to provide to the readers with the current understanding of the molecular mechanism how apoptotic cell-derived S1P triggers TAMs to promote lymphangiogenesis.
In this paper, we investigate an iterative scheme for finding a common point of the solution set of a variational inequality and the fixed point set of a Bregman relatively nonexpansive mapping. ...Moreover, a numerical example which shows the conclusion of our result is presented. Our results improve and generalize many known results in the current literature.
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•N719 dye loading optimization of sheet-like ZnO photoanodes has been carried out.•Dye adsorption on photoanodes is monitored by two UV–vis spectroscopic approaches.•An active real ...time methodology is compared with the standard passive technique.•Passive techniques give insights of reaction between dye and front surface of oxide.•Active monitoring technique gives information regarding actual sensitization time.
The peculiarly critical sensitization of zinc oxide with Ru-based dyes is the serious problem that prevents this semiconductor oxide from achieving photoconversion efficiencies in dye-sensitized solar cells (DSCs) comparable to those obtained with TiO2. Within this framework, methodologies for the optimization of the sensitization procedure of this material in acidic environments prove to be essential. In this paper, in view of streamlining the critical sensitization procedure of sheet-like zinc oxide-based DSC photoanodes with Ru-based dye, a comparative study on active and passive evaluations of N719 dye loading on sheet-like ZnO nanostructures are reported. For the active in-situ spectroscopic approach, a home-made set-up has been appropriately designed and developed for real time monitoring the dye adsorption on the ZnO-based photoanodes, whereas the standard passive dye loading measurements were performed after the electrodes had been sensitized for different time periods in the dye solutions of different concentrations. The dye adsorption results are carefully analyzed and correlated to the photovoltaic conversion efficiency and the incident photon-to-electron conversion efficiency (IPCE) of the corresponding ZnO-based DSCs, fabricated by employing our customized microfluidic architecture. The obtained results show that the real time monitoring of the dye absorption can be successfully employed for optimizing the sensitization conditions of ZnO-based photoanodes for DSCs. When applied online in a large scale production system for dye-sensitized solar cells, the proposed active method will permit to save both time and materials.
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