627 research outputs found
Mesenchymal and stemness circulating tumor cells in early breast cancer diagnosis
<p>Abstract</p> <p>Background</p> <p>Epithelial mesenchymal transition (EMT) is a crucial event likely involved in dissemination of epithelial cancer cells. This process enables them to acquire migratory/invasive properties, contributing to tumor and metastatic spread. To know if this event is an early one in breast cancer, we developed a clinical trial. The aim of this protocol was to detect circulating tumor cells endowed with mesenchymal and/or stemness characteristics, at the time of initial diagnosis. Breast cancer patients (n = 61), without visceral or bone metastasis were enrolled and analysis of these dedifferentiated circulating tumor cells (ddCTC) was realized.</p> <p>Methods</p> <p><it>AdnaGen </it>method was used for enrichment cell selection. Then, ddCTC were characterized by RT-PCR study of the following genes: PI3Kα, Akt-2, Twist1 (EMT markers) and ALDH1, Bmi1 and CD44 (stemness indicators).</p> <p>Results</p> <p>Among the studied primary breast cancer cohort, presence of ddCTC was detected in 39% of cases. This positivity is independant from tumor clinicopathological factors apart from the lymph node status.</p> <p>Conclusions</p> <p>Our data uniquely demonstrated that <it>in vivo </it>EMT occurs in the primary tumors and is associated with an enhanced ability of tumor cells to intravasate in the early phase of cancer disease. These results suggest that analysis of circulating tumor cells focused on cells showing mesenchymal or stemness characteristics might facilitate assessment of new drugs in clinical trials.</p
Topological Defects in the Random-Field XY Model and the Pinned Vortex Lattice to Vortex Glass Transition in Type-II Superconductors
As a simplified model of randomly pinned vortex lattices or charge-density
waves, we study the random-field XY model on square () and simple cubic
() lattices. We verify in Monte Carlo simulations, that the average
spacing between topological defects (vortices) diverges more strongly than the
Imry-Ma pinning length as the random field strength, , is reduced. We
suggest that for the simulation data are consistent with a topological
phase transition at a nonzero critical field, , to a pinned phase that is
defect-free at large length-scales. We also discuss the connection between the
possible existence of this phase transition in the random-field XY model and
the magnetic field driven transition from pinned vortex lattice to vortex glass
in weakly disordered type-II superconductors.Comment: LATEX file; 5 Postscript figures are available from [email protected]
Susceptibility of hamsters to clostridium difficile isolates of differing toxinotype
Clostridium difficile is the most commonly associated cause of antibiotic associated disease (AAD), which caused ~21,000 cases of AAD in 2011 in the U.K. alone. The golden Syrian hamster model of CDI is an acute model displaying many of the clinical features of C. difficile disease. Using this model we characterised three clinical strains of C. difficile, all differing in toxinotype; CD1342 (PaLoc negative), M68 (toxinotype VIII) and BI-7 (toxinotype III). The naturally occurring non-toxic strain colonised all hamsters within 1-day post challenge (d.p.c.) with high-levels of spores being shed in the faeces of animals that appeared well throughout the entire experiment. However, some changes including increased neutrophil influx and unclotted red blood cells were observed at early time points despite the fact that the known C. difficile toxins (TcdA, TcdB and CDT) are absent from the genome. In contrast, hamsters challenged with strain M68 resulted in a 45% mortality rate, with those that survived challenge remaining highly colonised. It is currently unclear why some hamsters survive infection, as bacterial and toxin levels and histology scores were similar to those culled at a similar time-point. Hamsters challenged with strain BI-7 resulted in a rapid fatal infection in 100% of the hamsters approximately 26 hr post challenge. Severe caecal pathology, including transmural neutrophil infiltrates and extensive submucosal damage correlated with high levels of toxin measured in gut filtrates ex vivo. These data describes the infection kinetics and disease outcomes of 3 clinical C. difficile isolates differing in toxin carriage and provides additional insights to the role of each toxin in disease progression
Deep sub-threshold production in Ar+KCl reactions at 1.76A GeV
We report first results on a deep sub-threshold production of the doubly
strange hyperon in a heavy-ion reaction. At a beam energy of 1.76A GeV
the reaction Ar+KCl was studied with the High Acceptance Di-Electron
Spectrometer (HADES) at SIS18/GSI. A high-statistics and high-purity
sample was collected, allowing for the investigation of the decay channel
. The deduced production
ratio of is significantly larger
than available model predictions.Comment: 4 pages, including 4 figure
Study of the quasi-free reaction with a deuterium beam at 1.25 GeV/nucleon
The tagged quasi-free reaction has been studied
experimentally with the High Acceptance Di-Electron Spectrometer (HADES) at GSI
at a deuteron incident beam energy of 1.25 GeV/nucleon ( 2.42
GeV/c for the quasi-free collision). For the first time, differential
distributions for production in collisions have been
collected in the region corresponding to the large transverse momenta of the
secondary particles. The invariant mass and angular distributions for the
reaction are compared with different models.
This comparison confirms the dominance of the -channel with
contribution. It also validates the changes previously introduced in the
Valencia model to describe two-pion production data in other isospin channels,
although some deviations are observed, especially for the
invariant mass spectrum. The extracted total cross section is also in much
better agreement with this model. Our new measurement puts useful constraints
for the existence of the conjectured dibaryon resonance at mass M 2.38
GeV and with width 70 MeV
Inclusive Dielectron Production in Ar+KCl Collisions at 1.76 AGeV studied with HADES
Results of the HADES measurement of inclusive dielectron production in Ar+KCl
collisions at a kinetic beam energy of 1.76 AGeV are presented. For the first
time, high mass resolution spectroscopy was performed. The invariant mass
spectrum of dielectrons is compared with predictions of UrQMD and HSD transport
codes.Comment: 4 pages, 3 figures - To appear in the conference proceedings for
Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse
Meson and di-electron production with HADES
The HADES experiment, installed at GSI, Darmstadt, measures di-electron
production in A+A, p/pi+N and p/pi+A collisions. Here, the pi0 and eta Dalitz
decays have been reconstructed in the exclusive p+p reaction at 2.2 GeV to form
a reference cocktail for long-lived di-electron sources. In the C+C reaction at
1 and 2 GeV/u, these long-lived sources have been subtracted from the measured
inclusive e+e- yield to exhibit the signal from the early phase of the
collision. The results suggest that resonances play an important role in dense
nuclear matter.Comment: Invited plenary talk at the 10th International Workshop On Meson
Production, Properties And Interaction (MESON 2008) 6-10 Jun 2008, Cracow,
Polan
Future perspectives at SIS-100 with HADES-at-FAIR
Currently, the HADES spectrometer undergoes un upgrade program to be prepared
for measurements at the upcoming SIS-100 synchrotron at FAIR. We describe the
current status of the HADES di-electron measurements at the SIS-18 and our
future plans for SIS-100.Comment: Invited contribution presented at the XLVII International Winter
Meeting on Nuclear Physics, Bormio (Italy), Jan. 26-30, 200
The High-Acceptance Dielectron Spectrometer HADES
HADES is a versatile magnetic spectrometer aimed at studying dielectron
production in pion, proton and heavy-ion induced collisions. Its main features
include a ring imaging gas Cherenkov detector for electron-hadron
discrimination, a tracking system consisting of a set of 6 superconducting
coils producing a toroidal field and drift chambers and a multiplicity and
electron trigger array for additional electron-hadron discrimination and event
characterization. A two-stage trigger system enhances events containing
electrons. The physics program is focused on the investigation of hadron
properties in nuclei and in the hot and dense hadronic matter. The detector
system is characterized by an 85% azimuthal coverage over a polar angle
interval from 18 to 85 degree, a single electron efficiency of 50% and a vector
meson mass resolution of 2.5%. Identification of pions, kaons and protons is
achieved combining time-of-flight and energy loss measurements over a large
momentum range. This paper describes the main features and the performance of
the detector system
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