Glucose Derivatives as Efficient Markers of Cell Reversible Electropermeabilization

Abstract— Molecules spontaneously transported inside the cells, like glucose derivatives, can also be used as electropermeabilization markers. In a previous study, we evaluated the uptake of a fluorescent deoxyglucose derivative (2-NBDG) by normal and electropermeabilized Chinese hamster cells. We extend here our previous study to two murine tumor model cells and investigate the effect of rolipram, a selective PDDE4 inhibitor, on 2-NBDG uptake by tumor cells, with or without electric pulses.2-NBDG was added to cell suspensions, and the cells exposed or not to eight square-wave electric pulses of 100- µs duration and of appropriate field amplitude delivered, were incubated at 37˚C and uptake was measured by flow cytometry. In rolipram experiments, cells were similarly processed after a 15 min pre-incubation with rolipram. In spite of significant uptake of 2-NBDG, mediated by GLUT transporters into non permeabilized cells, electric pulses significantly increased the 2-NBDG uptake into both murine tumor cells, even though the electrical parameters allowing a maximal uptake were different. Pretreatment with rolipram, only at high concentrations reduced 2-NBDG uptake in non-electropermeabilized cells, affecting more severely the DC-3F cells than the LPB cells. On the contrary, rolipram treatment did not attenuated the uptake of 2-NBDG in the electropermeabilized cells. We extended to other cell lines our previous observation that glucose derivatives can be used to detect cells reversible electropermeabilization. Moreover, our data suggest that rolipram could probably be used as a tool for improving the visualization of tumor using glucose derivatives, by affecting the uptake in the surrounding normal tissue

Effects of combined 5-Fluorouracil and ZnO NPs on human breast cancer MCF-7 Cells: P53 gene expression, Bcl-2 signaling pathway, and invasion activity

Objective(s): The significant contribution of nanoparticles to cancer treatment has attracted therapeutic attention. The present study aimed to evaluate the synergistic effects of 5-fluorouracil (5-FU) and zinc oxide nanoparticles (ZnO NPs) as multimodal drug delivery on human breast cancer MCF-7 cells. Materials and Methods: In this in-vitro study, the impact of 5-FU and ZnO NPs in the single or combined forms was evaluated on cell viability, colony formation, apoptosis, p53 gene expression, and Bcl-2 signaling protein in MCF-7 breast cancer cell line using several techniques, such as MTT, clonogenic assay, flow cytometry, real-time quantitative polymerase chain reaction, and Western blot. Results: In this study, 5-FU combined with ZnO NPs showed synergistic effects against MCF-7 within 48 hours. In addition, the combination of 5-FU and ZnO NPs at the respective concentrations of 1 mu M and 45 mu g/ml exhibited significant apoptosis (79.53%), p53 gene expression (3.6 folds), reduction of cell invasion (9.82%), and plating efficiency (5%), thereby leading to the significant reduction of cell viability (40 +/- 0.9%) and decreased Bcl-2 anti-apoptotic protein relative to untreated control cells. Conclusion: According to the results, the synergistic effects of combined ZnO NPs and 5-FU on MCF-7 human breast cancer cells were exerted via Bcl-2 inhibition and the up-regulation of p53 expressio

Quarkonium Suppression

I discuss quarkonium suppression in equilibriated strongly interacting matter. After a brief review of basic features of quarkonium production I discuss the application of recent lattice data on the heavy quark potential to the problem of quarkonium dissociation as well as the problem of direct lattice determination of quarkonium properties in finite temperature lattice QCD.Comment: Invited plenary talk presented on 4th International Conference on Physics and Astrophysics of Quark Gluon Plasma (ICPAQGP-2001), November 26-30, 2001, Jaipur; 12 pp, LaTeX, uses pramana.st

Double-Spin Asymmetry of J/psi Production in Polarized pp Collisions at HERA-N⃗\vec N

We calculated the color-octet contribution to the double spin asymmetry of $J/\psi$ hadroproduction with nonzero transverse momenta at fixed target energies $\sqrt{s}\simeq40$ GeV. It is shown that the color-octet contribution is dominant in the asymmetries. The expected asymmetries and statistical errors in a future option of HERA with longitudinally polarized protons at HERA-$\vec N$ should allow one to distinguish between different parametrizations for the polarized gluon distribution in the proton.Comment: 14 pages with 6 figures (epsfig), LaTeX; Some figures are changed and misprint is correcte

Psi prime to J/psi Ratio Measurements in PHENIX at RHIC

The ratio of the $\psi'$ over the $J/\psi$ production cross section in the dielectron channel has been measured in $\sqrt{s}=$ 200 GeV $p+p$ collisions with the PHENIX detector at RHIC. The analysis is based on fitting of the dielectron invariant mass spectra in the area around the $J/\psi$ and $\psi'$ signals in order to extract a ratio $\psi'$ over $J/\psi$ of 0.019$\pm 0.005($stat$)\pm 0.002($sys$)$ and a fractional feed-down contribution to $J/\psi$ from $\psi^\prime$ of $8.6 \pm 2.5$.Comment: 4 pages, 7 figures submitted to: Indian Journal of Physics (2010) - Proceedings of the 20th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (QM2008

Hadroproduction and Polarization of Charmonium

In the limit of heavy quark mass, the production cross section and polarization of quarkonia can be calculated in perturbative QCD. We study the $p_\perp$-averaged production of charmonium states in $\pi N$ collisions at fixed target energies. The data on the relative production rates of \jp and $\chi_J$ is found to disagree with leading twist QCD. The polarization of the \jp indicates that the discrepancy is not due to poorly known parton distributions nor to the size of higher order effects ($K$-factors). Rather, the disagreement suggests important higher twist corrections, as has been surmised earlier from the nuclear target $A$-dependence of the production cross section.Comment: 19 page

Ψ′/Ψ\Psi'/\Psi ratio in Nucleus-Nucleus Collisions : a Measure for the Chiral Symmetry Restoration Temperature ?

We argue that a decrease of the chiral scalar meson mass is responsible for re-creation of $\Psi'$ from $J/\Psi$ in ultrarelativistic nucleus-nucleus collisions. This causes the charmonium yields to freeze out at temperatures close to the chiral symmetry restoration temperature $T_c$. As a result $\Psi'/\Psi$ may serve as a thermometer for $T_c$ itself. Results in a detailed reaction model support the conjecture. They show good agreement with recent data of NA38 and NA50 for $J/\Psi$ and $\Psi'$ production in S on U and Pb on Pb collisions.Comment: 4 pages revtex including 3 postscript figure

Color-Octet J/ψJ/\psi Production at Low p⊥p_\perp

We study contributions from color-octet quarkonium formation mechanisms to $J/\psi$ hadroproduction at low $p_\perp$. We include transitions of color-octet $c\bar{c}$ states into ``direct'' $J/\psi$ and into $\chi_{1,2}$ which decay radiatively into a $J/\psi$. Together with earlier work, this calculation constitutes a complete analysis of $p_\perp$-integrated $J/\psi$ production at leading twist. We find that the leading-twist contribution is not sufficient to reproduce the observed production rates and polarization of the $J/\psi$ and $\chi_{1,2}$. Hence there must exist other important quarkonium production mechanisms at low $p_\perp$.Comment: REVTEX, 18 pages, 4 figures include

Measurement of the relative rate of prompt χc0, χc1 and χc2 production at √s=7TeV

Prompt production of charmonium χc0, χc1 and χc2 mesons is studied using proton-proton collisions at the LHC at a centre-of-mass energy of √s=7TeV. The χc mesons are identified through their decay to J/ψγ, with J/ψ→μ+mu− using photons that converted in the detector. A data sample, corresponding to an integrated luminosity of 1.0fb−1 collected by the LHCb detector, is used to measure the relative prompt production rate of χc1 and χc2 in the rapidity range 2.0<y<4.5 as a function of the J/ψ transverse momentum from 3 to 20 GeV/c. First evidence for χc0 meson production at a hadron collider is also presented