Elliptic flow of identified hadrons in Pb-Pb collisions at 1asNN = 2.76 TeV

The elliptic flow coefficient (v2) of identified particles in Pb-Pb collisions at 1asNN = 2.76 TeV was measured with the ALICE detector at the Large Hadron Collider (LHC). The results were obtained with the Scalar Product method, a two-particle corre- lation technique, using a pseudo-rapidity gap of | 06\u3b7| > 0.9 between the identified hadron under study and the reference particles. The v2 is reported for \u3c0\ub1, K\ub1, K0S, p+p, \u3c6, \u39b+\u39b, \u39e 12+\u39e+ and \u3a9 12+\u3a9+ in several collision centralities. In the low transverse momentum (pT) region, pT 3 GeV/c

Regenerative potential of leptomeningeal-derived oligodendrocytes in rat model of spinal cord injury

Transplantation of oligodendrocytes is a promising avenue to therapies of demyelinating disorders. We have established an efficient multi-step protocol to induce oligodendrocyte differentiation from a recently described population of Leptomeningeal Stem Cells (LeSCs). With this study we want to asses regenerative and reparative potential of transplanted LeSCs in two models of spinal cord lesion associated to demyelination. The first model was based on parenchymal injection lysophosphatidylcholine (LPC) in rat spinal cord (n=11). GFP-labelled LeSCs-derived oligodendrocyte precursors (GFP-LeSC-OPCs, 200,000 cells/spinal cord) were transplanted 7 days after LPC treatment. By confocal microscopy at days 1 and 7 after transplantation (dpt) we observed GFP-LeSC-OPCs expressing markers of either proliferation, neural progenitors or differentiation. The second model was contusive spinal cord injury (SCI). Here we transplanted 400,000 GFP-LeSC-OPCs at the site of contusion 6 days after injury (dpi). Locomotor evaluation was assessed by the Basso, Beattie, and Bresnahan (BBB) rating scale and subscale, Catwalk analysis and electrophysiology. Measurements were taken 1 and 6 dpi, and at several time points between 1 and 56 dpt. From 3 weeks after GFP-LeSC-OPCs transplantation (n=11), rats showed significant improvement in locomotion subparameters compared to controls (n=12) in BBB score. Catwalk analysis showed significant differences at 56 dpt whereas electrophysiological evaluation did not. In depth histochemical and functional analysis of transplanted cells in the two models is in progress. In conclusion we show that LeSCs-derived oligodendrocyte precursors transplanted in lesioned spinal cords survive and proceed toward differentiation and can promote functional recovery

Regenerative potential of leptomeningeal-derived oligodendrocytes in rat model of spinal cord injury

Transplantation of oligodendrocytes is a promising avenue to therapies of demyelinating disorders. We have established an efficient multi-step protocol to induce oligodendrocyte differentiation from a recently described population of Leptomeningeal Stem Cells (LeSCs). With this study we want to asses regenerative and reparative potential of transplanted LeSCs in two models of spinal cord lesion associated to demyelination. The first model was based on parenchymal injection lysophosphatidylcholine (LPC) in rat spinal cord (n=11). GFP-labelled LeSCs-derived oligodendrocyte precursors (GFP-LeSC-OPCs, 200,000 cells/spinal cord) were transplanted 7 days after LPC treatment. By confocal microscopy at days 1 and 7 after transplantation (dpt) we observed GFP-LeSC-OPCs expressing markers of either proliferation, neural progenitors or differentiation. The second model was contusive spinal cord injury (SCI). Here we transplanted 400,000 GFP-LeSC-OPCs at the site of contusion 6 days after injury (dpi). Locomotor evaluation was assessed by the Basso, Beattie, and Bresnahan (BBB) rating scale and subscale, Catwalk analysis and electrophysiology. Measurements were taken 1 and 6 dpi, and at several time points between 1 and 56 dpt. From 3 weeks after GFP-LeSC-OPCs transplantation (n=11), rats showed significant improvement in locomotion subparameters compared to controls (n=12) in BBB score. Catwalk analysis showed significant differences at 56 dpt whereas electrophysiological evaluation did not. In depth histochemical and functional analysis of transplanted cells in the two models is in progress. In conclusion we show that LeSCs-derived oligodendrocyte precursors transplanted in lesioned spinal cords survive and proceed toward differentiation and can promote functional recovery

Differentiation of mature oligodendrocytes from small biopsy of adult rat spinal cord meninges

In most diseases of the spinal cord, demyelination plays an important role in the generation and progression of the neurodegenerative lesion. Regeneration of oligodendrocytes is apparently insufficient for repair and attempts with regenerative transplantation approaches have been so far limited by lack of adequate sources of oligodendrocytes. Here we report results obtained with a new protocol for production of oligodendrocyte precursors (OPCs ) from LeSCs, a population of neural stem cells of the leptomeninges. Starting from a small (approx 3x10 mm strip) biopsy of adult rat spinal cord meninges, neurospheres were produced. By adjusting culture conditions, we developed a three-step protocol (1-induction, 2-differentiation, 3-maturation) to produce oligodendrocytes. Confocal immunofluorescence and Real time-RT PCR were used to monitor cell changes. NG2 was expressed at high level at step 1 and almost disappeared at step 3. O4 expression was highest at step 2. At step 3, 100% of the cells expressed MBP at levels up to 30 folds higher than in neurosphere stage. Mature cells also expressed plp1, cnp, mag and mog, markers of mature oligodendrocytes. Efficiency was high and usually 1.8-3.6 x 1012 OPCs were obtained from 1x 105 cells from neurospheres (n=7). In conclusion, we have established an efficient and reproducible method to generate large numbers of cells of oligodendrocyte-lineage at different and controlled levels of differentiation. This observation paves the way for exploitation of LeSCs in regenerative therapies of demyelinating disorders

Regenerative potential of leptomeninges-derived oligodendrocytes in a rat model of spinal cord injury

Spinal cord injury is characterized by multiple pathological reactions resulting in loss of neurons and oligodendrocytes, demyelination of spared axons and formation of scar tissue at the lesion site. Regeneration of oligodendrocytes to prevent or limit demyelination is apparently insufficient for repair and attempts with regenerative transplantation approaches have been so far limited also because of lack of adequate sources of oligodendrocytes. Here we report results obtained with a new protocol for production of oligodendrocyte precursors (OPCs ) from LeSCs [1], a population of neural stem cells of the leptomeninges. Starting from a small biopsy of adult rat spinal cord meninges, neurospheres were produced. By adjusting culture conditions, we developed a three-step protocol (1-induction, 2-differentiation, 3-maturation) to produce oligodendrocytes. Confocal immunofluorescence and Real time-RT PCR were used to monitor cell changes. During the progression of oligodendrocytes lineage we observed different expression of maturation stage-specific markers; at the end of the maturation progression, expression of typical adult olygodendorcyte markers plp1, cnp, mag and mog was revealed by Real time-RT PCR. With this study we want to asses regenerative and reparative potential of transplanted LeSCs-derived OPCs in adult rats exposed to a moderate traumatic lesion at T8 using Impactor as described in ref. 1. Six days after injury (dpi), 600,000 GFP-LeSC-OPCs were transplanted at the site of contusion. For control, lesioned animals were injected with culture medium and no cells. Locomotor evaluation was assessed by the Basso, Beattie, and Bresnahan (BBB) rating scale and subscale, Catwalk analysis and electrophysiology. Measurements were taken 1 and 6 dpi, and at several time points between 1 and 56 days after transplantation (dpt). From 1 week after GFP-LeSC-OPCs transplantation (n=11), rats showed significant improvement in locomotion subparameters compared to controls (n=12) in BBB score. Catwalk analysis showed significant differences at 56 dpt whereas significant differences were not observed by electrophysiological evaluation. Preliminary data indicate that 63 dpt transplanted cells are present in the parenchyma of the spinal cord with tendency to accumulate in the distal regions of the lesioned tissue. Temporal analysis of the fate of transplanted cells is in progress. These findings pave the way for exploitation of LeSCs in regenerative therapies of demyelinating disorders

Production of charged pions, kaons and protons at large transverse momenta in pp and Pb–Pb collisions at sNN=2.76\sqrt{s_{NN}}=2.76 TeV

Transverse momentum spectra of pi(+/-), K-+/- and p((p) over bar) up to p(T) = 20 GeV/c at mid-rapidity in pp, peripheral (60-80%) and central (0-5%) Pb-Pb collisions at v root s(NN) = 2.76 TeV have been measured using the ALICE detector at the Large Hadron Collider. The proton-to-pion and the kaon-to-pionratios both show a distinct peak at p(T) approximate to 3 GeV/c in central Pb-Pb collisions. Below the peak, p(T) 10 GeV/c particle ratios in pp and Pb-Pb collisions are in agreement and the nuclear modification factors for pi(+/-), K-+/- and p((p) over bar) indicate that, within the systematic and statistical uncertainties, the suppression is the same. This suggests that the chemical composition of leading particles from jets in the medium is similar to that of vacuum jets

Centrality, rapidity and transverse momentum dependence of J/\u3c8 suppression in Pb-Pb collisions at 1asNN= 2.76TeV

The inclusive J/.nuclear modification factor (R-AA) in Pb-Pb collisions at root(NN)-N-S = 2.76TeVhas been measured by ALICE as a function of centrality in the e+ e-decay channel at mid-rapidity (| y| < 0.8) and as a function of centrality, transverse momentum and rapidity in the + -decay channel at forward-rapidity (2.5 < y < 4). The J/.yields measured in Pb-Pb are suppressed compared to those in ppcollisions scaled by the number of binary collisions. The RAAintegrated over a centrality range corresponding to 90% of the inelastic Pb-Pb cross section is 0.72 - 0.06(stat.) - 0.10(syst.) at mid-rapidity and 0.58 - 0.01(stat.) - 0.09(syst.) at forward-rapidity. At low transverse momentum, significantly larger values of RAAare measured at forward-rapidity compared to measurements at lower energy. These features suggest that a contribution to the J/.yield originates from charm quark (re) combination in the deconfined partonic medium