501 research outputs found
Morphologic Spectrum of Renal Cell Carcinoma, Unclassified: An Analysis of 136 Cases
Aims
Renal cell carcinoma, unclassified (RCCU) is a category that includes a morphologically and biologically heterogeneous group of tumors that are unable to be diagnosed as other well-defined entities. We aim to describe the morphologic findings of tumors within this category and to determine the most frequent morphologic features leading to classification difficulty.
Methods and results
One hundred and thirty-six cases of RCCU were examined. Patients ranged in age from 23 to 87 years. Seventy-seven patients were men and 59 were women. International Society of Urological Pathology (ISUP) grade was most commonly 3 (n=66), followed by 2 (n=42) and 4 (n=28). Tumor size ranged from 0.6 cm to 24.9 cm. The AJCC pathologic T categories included pT1a (n=50), pT1b (n=14), pT2a (n=7), pT2b (n=4), pT3a (n=50), and pT4 (n=9). Forty-four cases included lymph node(s), of which 41% (n=18) had metastases. Tumors were assessed for a variety of histologic features and assigned to the following morphologic groups: predominantly oncocytoma/chromophobe RCC-like; clear cell RCC-like; papillary RCC-like; collecting duct-like; and pure sarcomatoid differentiation. The majority of the oncocytoma/chromophobe and clear cell RCC-like phenotypes were low stage (pT1 or pT2). The papillary RCC-like, collecting duct-like, and pure sarcomatoid phenotypes were mostly high stage (pT3 or pT4).
Conclusions
RCCU is a term that encompasses tumors with a variety of morphologic features and a wide biologic spectrum. The most common source of diagnostic difficulty was tumors composed of predominantly eosinophilic cells
Probing the Local Velocity Distribution of WIMP Dark Matter with Directional Detectors
We explore the ability of directional nuclear-recoil detectors to constrain
the local velocity distribution of weakly interacting massive particle (WIMP)
dark matter by performing Bayesian parameter estimation on simulated
recoil-event data sets. We discuss in detail how directional information, when
combined with measurements of the recoil-energy spectrum, helps break
degeneracies in the velocity-distribution parameters. We also consider the
possibility that velocity structures such as cold tidal streams or a dark disk
may also be present in addition to the Galactic halo. Assuming a
carbon-tetrafluoride detector with a 30-kg-yr exposure, a 50-GeV WIMP mass, and
a WIMP-nucleon spin-dependent cross-section of 0.001 pb, we show that the
properties of a cold tidal stream may be well constrained. However, measurement
of the parameters of a dark-disk component with a low lag speed of ~50 km/s may
be challenging unless energy thresholds are improved.Comment: 38 pages, 15 figure
Evidence of a dual histogenetic pathway of sacrococcygeal teratomas
Aims
Sacrococcygeal teratomas are rare tumours that occur most frequently in neonates, although adult cases also occur. The molecular pathogenesis of these tumours and their long-term prognosis is uncertain. We investigated the i(12p) status of a large number of primary sacrococcygeal teratomas in both children and adults, including cases with malignant germ cell tumour elements.
Methods and results
Fifty-four sacrococcygeal teratoma specimens from 52 patients were identified, and available follow-up information was obtained. Fluorescence in-situ hybridization analysis was performed to identify isochromosome 12p [i(12p)] abnormalities on paraffin blocks of the tumours. Among the 48 paediatric patients, there were 44 teratomas and four tumours with combined teratoma and yolk sac tumour (one of whom also had primitive neuroectodermal tumour). The teratomas included 37 mature teratomas and 11 immature teratomas (four grade 1, two grade 2, and five grade 3). The 44 teratomas lacking a yolk sac tumour component were all negative for i(12p). The four tumours with a yolk sac tumour component were all positive for i(12p). The four adult cases all lacked non-teratomatous germ cell tumour components, immature elements, and i(12p). Follow-up information was available for 32 patients. Two patients with teratoma had recurrence, but were alive with no evidence of disease after long-term follow-up. One patient with combined teratoma and yolk sac tumour had recurrence 7 months after resection. The other patients were alive with no evidence of disease at last follow-up.
Conclusions
Our data suggest that paediatric sacrococcygeal teratomas should be considered as two distinct groups with divergent histogenetic pathways. The prognosis of these tumours is excellent, despite rare recurrence
Preservation of Truncal Genomic Alterations in Clear Cell and Papillary Renal Cell Carcinomas with Sarcomatoid Features: An Intra- and Intertumoral, Multifocal Fluorescence in Situ Hybridization Analysis Reveals Limited Genetic Heterogeneity
Understanding tumor genomic heterogeneity may offer vital information in an age of targeted therapy for renal cell carcinoma. We sought to investigate hallmark truncal chromosomal alterations between conventional, sarcomatoid, and matched metastatic tumor foci in clear cell and papillary renal cell carcinomas. A retrospective review identified 58 cases including clear cell (CCRCC) and papillary renal cell carcinomas (PRCC). All cases contained sarcomatoid transformation. Additionally, 10 of 58 patients had matched metastatic disease available for analysis. Three separate foci of conventional and sarcomatoid morphologies were analyzed in each tumor using dual color interphase fluorescence in situ hybridization. In the CCRCC cohort, hallmark chromosome 3p deletion was identified in 71% of cases (37/52). Complete concordance of chromosomal status between intratumoral foci in sarcomatoid and conventional foci was 89% and 86%, respectively. Overall chromosome 3p status between matched conventional and sarcomatoid morphologies was identified in 98% of cases (51/52). Hallmark 3p deletion was present in 91% of CCRCC metastatic samples (10/11) and was concordant with the matched primary CCRCC tumor in 91% (10/11). In the PRCC cohort, trisomy 7 and 17 was identified in all six cases (6/6). Complete concordance between intratumoral foci of trisomy 7 and 17 was 83% (5/6). Trisomy 7 and 17 were identified in all metastatic PRCC samples with 100% concordance with the matched primary tumor. These data show the relative preservation of truncal chromosomal abnormalities between conventional and sarcomatoid morphologic as well as matched metastatic settings
: Familias populares e institução escolar : entre autonomia e heteronomia
Version française de "Familias populares e institução escolar : entre autonomia e heteronomia", Educação e Pesquisa, 2010, vol. 36, n°espcial, p. 65-76International audienceL'article se propose d'analyser quelques problèmes théoriques dans l'étude des relations entre familles populaires et école, problèmes qui sont ceux que rencontre la sociologie dans l'étude des classes populaires et de leurs relations avec le monde dominant et les institutions. Il explore la possibilité de dépasser l'alternative entre une perspective strictement légitimiste qui tend à réduire les classes populaires et leurs pratiques au rapport de domination qui les aliène (hétéronomie) et la perspective relativiste qui les envisage dans une altérité radicale (autonomie) en occultant les rapports sociaux de domination. Il insiste sur l'ambivalence des logiques et des pratiques des familles populaire
Comment on "On the subtleties of searching for dark matter with liquid xenon detectors"
In a recent manuscript (arXiv:1208.5046) Peter Sorensen claims that
XENON100's upper limits on spin-independent WIMP-nucleon cross sections for
WIMP masses below 10 GeV "may be understated by one order of magnitude or
more". Having performed a similar, though more detailed analysis prior to the
submission of our new result (arXiv:1207.5988), we do not confirm these
findings. We point out the rationale for not considering the described effect
in our final analysis and list several potential problems with his study.Comment: 3 pages, no figure
Removing krypton from xenon by cryogenic distillation to the ppq level
The XENON1T experiment aims for the direct detection of dark matter in a
cryostat filled with 3.3 tons of liquid xenon. In order to achieve the desired
sensitivity, the background induced by radioactive decays inside the detector
has to be sufficiently low. One major contributor is the -emitter
Kr which is an intrinsic contamination of the xenon. For the XENON1T
experiment a concentration of natural krypton in xenon Kr/Xe < 200
ppq (parts per quadrillion, 1 ppq = 10 mol/mol) is required. In this
work, the design of a novel cryogenic distillation column using the common
McCabe-Thiele approach is described. The system demonstrated a krypton
reduction factor of 6.410 with thermodynamic stability at process
speeds above 3 kg/h. The resulting concentration of Kr/Xe < 26 ppq
is the lowest ever achieved, almost one order of magnitude below the
requirements for XENON1T and even sufficient for future dark matter experiments
using liquid xenon, such as XENONnT and DARWIN
Solitary fibrous tumour of the genitourinary tract: a clinicopathological study of 11 cases and their association with the NAB2-STAT6 fusion gene
Aims To characterise clinicopathological features and clinical outcomes of the genitourinary tract solitary fibrous tumours, incorporating NAB2-STAT6 gene fusion status.
Methods The presence of the molecular hallmark NAB2-STAT6 gene fusion and for the defining fusion partner product STAT6 was assessed in 11 cases of the genitourinary tract solitary fibrous tumours. NAB2-STAT6 gene fusion analysis was performed using a break-apart fluorescence in situ hybridisation (FISH) probe using a probe cocktail with Bacterial artificial chromosome (BAC) clones for STAT6 and NAB2.
Results Eleven solitary fibrous tumours were diagnosed in eight male patients and three female patients with a mean age of 46 years (range: 11–64 years). Four of the tumours had malignant histological features, and three were considered moderate risk for metastasis. With a mean follow-up time of 61 months, 1 recurred locally and 2 presented at distant metastatic sites. Using a break-apart FISH probe cocktail, we found the NAB2-STAT6 gene fusion and nuclear STAT6 expression in 58% and 91% of cases, respectively. However, the NAB2-STAT6 fusion status was not correlated with STAT6 expression or useful in discriminating between malignant histological features or subsequent clinical outcomes in the genitourinary solitary fibrous tumours.
Conclusions A subset of solitary fibrous tumours of the genitourinary tract behaved aggressively. Using a break-apart FISH probe cocktail, we found the NAB2-STAT6 gene fusion in 64% of cases. However, the NAB2-STAT6 fusion status was not correlated with STAT6 expression or useful in discriminating between low-risk or high-risk tumours and subsequent clinical outcomes
Production of Medical Radioisotopes with High Specific Activity in Photonuclear Reactions with Beams of High Intensity and Large Brilliance
We study the production of radioisotopes for nuclear medicine in
photonuclear reactions or ()
photoexcitation reactions with high flux [()/s], small
diameter m and small band width () beams produced by Compton back-scattering of laser
light from relativistic brilliant electron beams. We compare them to (ion,np) reactions with (ion=p,d,) from particle accelerators like
cyclotrons and (n,) or (n,f) reactions from nuclear reactors. For
photonuclear reactions with a narrow beam the energy deposition in the
target can be managed by using a stack of thin target foils or wires, hence
avoiding direct stopping of the Compton and pair electrons (positrons).
isomer production via specially selected cascades
allows to produce high specific activity in multiple excitations, where no
back-pumping of the isomer to the ground state occurs. We discuss in detail
many specific radioisotopes for diagnostics and therapy applications.
Photonuclear reactions with beams allow to produce certain
radioisotopes, e.g. Sc, Ti, Cu, Pd, Sn,
Er, Pt or Ac, with higher specific activity and/or
more economically than with classical methods. This will open the way for
completely new clinical applications of radioisotopes. For example Pt
could be used to verify the patient's response to chemotherapy with platinum
compounds before a complete treatment is performed. Also innovative isotopes
like Sc, Cu and Ac could be produced for the first time
in sufficient quantities for large-scale application in targeted radionuclide
therapy.Comment: submitted to Appl. Phys.
Characterizing, modelling and understanding the climate variability of the deep water formation in the North-Western Mediterranean Sea
Observing, modelling and understanding the climate-scale variability of the deep water formation (DWF) in the North-Western Mediterranean Sea remains today very challenging. In this study, we first characterize the interannual variability of this phenomenon by a thorough reanalysis of observations in order to establish reference time series. These quantitative indicators include 31 observed years for the yearly maximum mixed layer depth over the period 1980–2013 and a detailed multi-indicator description of the period 2007–2013. Then a 1980–2013 hindcast simulation is performed with a fully-coupled regional climate system model including the high-resolution representation of the regional atmosphere, ocean, land-surface and rivers. The simulation reproduces quantitatively well the mean behaviour and the large interannual variability of the DWF phenomenon. The model shows convection deeper than 1000 m in 2/3 of the modelled winters, a mean DWF rate equal to 0.35 Sv with maximum values of 1.7 (resp. 1.6) Sv in 2013 (resp. 2005). Using the model results, the winter-integrated buoyancy loss over the Gulf of Lions is identified as the primary driving factor of the DWF interannual variability and explains, alone, around 50 % of its variance. It is itself explained by the occurrence of few stormy days during winter. At daily scale, the Atlantic ridge weather regime is identified as favourable to strong buoyancy losses and therefore DWF, whereas the positive phase of the North Atlantic oscillation is unfavourable. The driving role of the vertical stratification in autumn, a measure of the water column inhibition to mixing, has also been analyzed. Combining both driving factors allows to explain more than 70 % of the interannual variance of the phenomenon and in particular the occurrence of the five strongest convective years of the model (1981, 1999, 2005, 2009, 2013). The model simulates qualitatively well the trends in the deep waters (warming, saltening, increase in the dense water volume, increase in the bottom water density) despite an underestimation of the salinity and density trends. These deep trends come from a heat and salt accumulation during the 1980s and the 1990s in the surface and intermediate layers of the Gulf of Lions before being transferred stepwise towards the deep layers when very convective years occur in 1999 and later. The salinity increase in the near Atlantic Ocean surface layers seems to be the external forcing that finally leads to these deep trends. In the future, our results may allow to better understand the behaviour of the DWF phenomenon in Mediterranean Sea simulations in hindcast, forecast, reanalysis or future climate change scenario modes. The robustness of the obtained results must be however confirmed in multi-model studies
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