Dendritic cell viability is decreased after phagocytosis of apoptotic tumor cells induced by staurosporine or vaccinia virus infection

Background and Objectives. Dendritic cells (DC) primed with tumor antigens can effectively mediate the regression of a variety of established solid malignancies in both murine and human models. Several experimental studies indicate that apoptotic bodies are an optimal source of tumor antigens for ex vivo priming of DC. However, the clinical use of killed tumor cells as a source of antigens will require an optimal methodology to induce effective tumor cell apoptosis. Design and Methods. The goal of this study was to compare the efficiency of three agents for inducing neoplastic B lymphocyte apoptosis; staurosporine, infection by modified vaccinia (MVA) viral particles and ultraviolet C (UVC) radiation. Results. The three methods were finely tuned to induce apoptosis in more than 90% of tumor cells after 24 hours of exposure. However, the viability of monocyte-derived DC, loaded with B-cell tumor apoptotic bodies induced by staurosporine or MVA viral particles, decreased dramatically within 48 hours after phagocytosis of the killed neoplastic cells. The persistence of the apoptosis-inducing agents in the apoptotic bodies and not in the tumor supernatant, was responsible for the observed damage to DC viability. In contrast, DC viability was not affected after uptake of tumor cells killed through UVC-irradiation. Furthermore, B-lymphoblastic cell line (LCL)-specific T cells were reactivated by DC loaded with apoptotic bodies induced by UVC-rays. Interpretation and Conclusions. Since the method used to induce tumor cell apoptosis might be detrimental to DC viability, these findings should be considered when designing anticancer vaccination programs

ANTARES: the first undersea neutrino telescope

The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

A perturbation solution of Michaelis-Menten kinetics in a total quasi-steady-state framework

In this paper we expand the equations governing Michaelis– Menten kinetics in a total quasi-steady-state setting, finding the first order uniform expansions. Our results improve previous approximations and work well especially in presence of an enzyme excess

Quasi-Steady-State Approximations of the Chemical Master Equation in Enzyme Kinetics - Application to the Double Phosphorylation/Dephosphorylation Cycle

The Chemical Master Equation (CME) provides an accurate stochastic description of complex biochemical processes in terms of probability distribution of the underlying chemical population. By reason of that, CMEs are usually considered {\it stochastic} methods for the analysis of biochemical reactions, in contrast to {\it deterministic} methods, handling biochemical processes by means of Ordinary Differential Equations (ODE) expressing the evolution of the concentration for each involved species. In this deterministic framework, a common practice is to exploit Quasi-Steady State Approximations (QSSAs) to reduce the dimensionality of the system and fasten numerical simulations. In the present paper, we investigate the applicability of QSSAs from a stochastic viewpoint, by making use of the CMEs in the specific case of the double phosphorylation-dephosphorylation reaction. To this end, the stochastic approach is applied to the non-approximated original chemical network, as well as to the \textit{standard} and \textit{total} QSSAs, confirming by simulations the effectiveness and superiority of the latter with respect to the former

Studio numerico di un buckling con ostacolo di un guscio sferico elastico

Consiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal