University of Crete

About: University of Crete is a education organization based out in Rethymno, Greece. It is known for research contribution in the topics: Population & Galaxy. The organization has 8681 authors who have published 21684 publications receiving 709078 citations. The organization is also known as: Panepistimio Kritis.

Membrane androgen receptor activation induces apoptotic regression of human prostate cancer cells in vitro and in vivo.

Abstract: Nongenomic androgen actions imply mechanisms different from the classical intracellular androgen receptor (iAR) activation. We have recently reported the identification of a membrane androgen receptor (mAR) on LNCaP human prostate cancer cells, mediating testosterone signal transduction within minutes. In the present study we provide evidence that activation of mAR by nonpermeable, BSA-coupled testosterone results in 1) inhibition of LNCaP cell growth (with a 50% inhibitory concentration of 5.08 nM, similar to the affinity of testosterone for membrane sites); 2) induction in LNCaP cells of both apoptosis and the proapoptotic Fas protein; and 3) a significant decrease in migration, adhesion, and invasion of iAR-negative DU145 human prostate cancer cells. These actions persisted in the presence of antiandrogen flutamide or after decreasing the content of iAR in LNCaP cells by iAR antisense oligonucleotides. Testosterone-BSA was also effective in inducing apoptosis of DU145 human prostate cancer cells, negative for iAR, but expressing mAR sites. In LNCaP cell-inoculated nude mice, treatment with testosterone-BSA (4.8 mg/kg body weight) for 1 month resulted in a 60% reduction of tumor size compared with that in control animals receiving only BSA, an effect that was not affected by the antiandrogen flutamide. Our findings suggest that activators of mAR may represent a new class of antitumoral agents of prostate cancer.

The programmed death 1/programmed death ligand 1 inhibitory pathway is up-regulated in rheumatoid synovium and regulates peripheral T cell responses in human and murine arthritis.

Abstract: Objective T cells play a major role in the pathogenesis of rheumatoid arthritis (RA). The programmed death 1 (PD-1)/programmed death ligand 1 (PDL-1) pathway is involved in peripheral tolerance through inhibition of T cells at the level of synovial tissue. The aim of this study was to examine the role of PD-1/PDL-1 in the regulation of human and murine RA. Methods In synovial tissue and synovial fluid (SF) mononuclear cells from patients with RA, expression of PD-1/PDL-1 was examined by immunohistochemistry and flow cytometry, while PD-1 function was assessed in RA peripheral blood (PB) T cells after stimulation of the cells with anti-CD3 and PDL-1.Fc to crosslink PD-1. Collagen-induced arthritis (CIA) was induced in PD-1−/− C57BL/6 mice, and recombinant PDL-1.Fc was injected intraperitoneally to activate PD-1 in vivo. Results RA synovium and RA SF were enriched with PD-1+ T cells (mean ± SEM 24 ± 5% versus 4 ± 1% in osteoarthritis samples; P = 0.003) and enriched with PDL-1+ monocyte/macrophages. PD-1 crosslinking inhibited both T cell proliferation and production of interferon-γ (IFNγ) in RA patients; PB T cells incubated with RA SF, as well as SF T cells from patients with active RA, exhibited reduced PD-1–mediated inhibition of T cell proliferation at suboptimal, but not optimal, concentrations of PDL-1.Fc. PD-1−/− mice demonstrated increased incidence of CIA (73% versus 36% in wild-type mice; P < 0.05) and greater severity of CIA (mean maximum arthritis score 5.0 versus 2.3 in wild-type mice; P = 0.040), and this was associated with enhanced T cell proliferation and increased production of cytokines (IFNγ and interleukin-17) in response to type II collagen. PDL-1.Fc treatment ameliorated the severity of CIA and reduced T cell responses. Conclusion The negative costimulatory PD-1/PDL-1 pathway regulates peripheral T cell responses in both human and murine RA. PD-1/PDL-1 in rheumatoid synovium may represent an additional target for immunomodulatory therapy in RA.

Multiple Concentric Gating Traffic Control in Large-Scale Urban Networks

Abstract: A new gating strategy for concentric cities based on the notion of the macroscopic or network fundamental diagram and the feedback-based gating concept is introduced and successfully tested. Different regions of large-scale urban networks may experience congestion at different levels and times during the peak period. In this paper, the zone, including the initial core of congestion, is considered as the first region, which has to be protected from congestion via gating; eventually, as the congestion continues to expand, the border of an extended network part becomes the second perimeter for gating control. Remarkable extensions while distributing the ordered controller flow to the gated traffic signals in case of low demand or occurrence of spillback are also considered. A greater part of the San Francisco urban network is used as test-bed within a microscopic simulation environment. Significant improvements in terms of network-wide mean speed and average delay per kilometer are obtained compared to the single perimeter gating and non-gating simulation scenarios.

Unveiling pseudospin and angular momentum in photonic graphene

Abstract: Pseudospin, an additional degree of freedom inherent in graphene, plays a key role in understanding many fundamental phenomena such as the anomalous quantum Hall effect, electron chirality and Klein paradox. Unlike the electron spin, the pseudospin was traditionally considered as an unmeasurable quantity, immune to Stern-Gerlach-type experiments. Recently, however, it has been suggested that graphene pseudospin is a real angular momentum that might manifest itself as an observable quantity, but so far direct tests of such a momentum remained unfruitful. Here, by selective excitation of two sublattices of an artificial photonic graphene, we demonstrate pseudospin-mediated vortex generation and topological charge flipping in otherwise uniform optical beams with Bloch momentum traversing through the Dirac points. Corroborated by numerical solutions of the linear massless Dirac-Weyl equation, we show that pseudospin can turn into orbital angular momentum completely, thus upholding the belief that pseudospin is not merely for theoretical elegance but rather physically measurable.

Striped instability of a holographic Fermi-like liquid

Abstract: We consider a holographic description of a system of strongly-coupled fermions in 2 + 1 dimensions based on a D7-brane probe in the background of D3-branes. The black hole embedding represents a Fermi-like liquid. We study the excitations of the Fermi liquid system. Above a critical density which depends on the temperature, the system becomes unstable towards an inhomogeneous modulated phase which is similar to a charge density and spin wave state. The essence of this instability can be effectively described by a Maxwell-axion theory with a background electric field. We also consider the fate of zero sound at non-zero temperature.