197 research outputs found
Denjoy-Carleman differentiable perturbation of polynomials and unbounded operators
Let for be a -mapping with values unbounded
operators with compact resolvents and common domain of definition which are
self-adjoint or normal. Here stands for C^\om (real analytic), a
quasianalytic or non-quasianalytic Denjoy-Carleman class, , or a
H\"older continuity class C^{0,\al}. The parameter domain is either
or or an infinite dimensional convenient vector
space. We prove and review results on -dependence on of the
eigenvalues and eigenvectors of .Comment: 8 page
Microsatellite instability, KRAS mutations and cellular distribution of TRAIL-receptors in early stage colorectal cancer.
Thus, we evaluated the immunofluorescence pattern of TRAIL-receptors and E-cadherin to assess the fraction of membrane-bound TRAIL-receptors in 231 selected patients with early-stage CRC undergoing surgical treatment only. Moreover, we investigated whether membrane staining for TRAIL-receptors as well as the presence of KRAS mutations or of microsatellite instability (MSI) had an effect on survival and thus a prognostic effect.
The fact that the receptors for the TNF-related apoptosis inducing ligand (TRAIL) are almost invariably expressed in colorectal cancer (CRC) represents the rationale for the employment of TRAIL-receptors targeting compounds for the therapy of patients affected by this tumor. Yet, first reports on the use of these bioactive agents provided disappointing results. We therefore hypothesized that loss of membrane-bound TRAIL-R might be a feature of some CRC and that the evaluation of membrane staining rather than that of the overall expression of TRAIL-R might predict the response to TRAIL-R targeting compounds in this tumor. As expected, almost all CRC samples stained positive for TRAIL-R1 and 2. Instead, membrane staining for these receptors was positive in only 71% and 16% of samples respectively. No correlation between KRAS mutation status or MSI-phenotype and prognosis could be detected. TRAIL-R1 staining intensity correlated with survival in univariate analysis, but only membranous staining of TRAIL-R1 and TRAIL-R2 on cell membranes was an independent predictor of survival (cox multivariate analysis: TRAIL-R1: p = 0.019, RR 2.06[1.12-3.77]; TRAIL-R2: p = 0.033, RR 3.63[1.11-11.84]). In contrast to the current assumptions, loss of membrane staining for TRAIL-receptors is a common feature of early stage CRC which supersedes the prognostic significance of their staining intensity. Failure to achieve therapeutic effects in recent clinical trials using TRAIL-receptors targeting compounds might be due to insufficient selection of patients bearing tumors with membrane-bound TRAIL-receptors
An algebraic approach to manifold-valued generalized functions
We discuss the nature of structure-preserving maps of varies function
algebras. In particular, we identify isomorphisms between special Colombeau
algebras on manifolds with invertible manifold-valued generalized functions in
the case of smooth parametrization. As a consequence, and to underline the
consistency and validity of this approach, we see that this generalized version
on algebra isomorphisms in turn implies the classical result on algebras of
smooth functions.Comment: 7 page
Un-reduction
This paper provides a full geometric development of a new technique called
un-reduction, for dealing with dynamics and optimal control problems posed on
spaces that are unwieldy for numerical implementation. The technique, which was
originally concieved for an application to image dynamics, uses Lagrangian
reduction by symmetry in reverse. A deeper understanding of un-reduction leads
to new developments in image matching which serve to illustrate the
mathematical power of the technique.Comment: 25 pages, revised versio
A p38 MitogenâActivated Protein Kinase Inhibitor Arrests Active Alveolar Bone Loss in a Rat Periodontitis Model
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141943/1/jper1992.pd
Invariant higher-order variational problems II
Motivated by applications in computational anatomy, we consider a
second-order problem in the calculus of variations on object manifolds that are
acted upon by Lie groups of smooth invertible transformations. This problem
leads to solution curves known as Riemannian cubics on object manifolds that
are endowed with normal metrics. The prime examples of such object manifolds
are the symmetric spaces. We characterize the class of cubics on object
manifolds that can be lifted horizontally to cubics on the group of
transformations. Conversely, we show that certain types of non-horizontal
geodesics on the group of transformations project to cubics. Finally, we apply
second-order Lagrange--Poincar\'e reduction to the problem of Riemannian cubics
on the group of transformations. This leads to a reduced form of the equations
that reveals the obstruction for the projection of a cubic on a transformation
group to again be a cubic on its object manifold.Comment: 40 pages, 1 figure. First version -- comments welcome
High-precision molecular dynamics simulation of UO2-PuO2: superionic transition in uranium dioxide
Our series of articles is devoted to high-precision molecular dynamics
simulation of mixed actinide-oxide (MOX) fuel in the rigid ions approximation
using high-performance graphics processors (GPU). In this article we assess the
10 most relevant interatomic sets of pair potential (SPP) by reproduction of
the Bredig superionic phase transition (anion sublattice premelting) in uranium
dioxide. The measurements carried out in a wide temperature range from 300K up
to melting point with 1K accuracy allowed reliable detection of this phase
transition with each SPP. The {\lambda}-peaks obtained are smoother and wider
than it was assumed previously. In addition, for the first time a pressure
dependence of the {\lambda}-peak characteristics was measured, in a range from
-5 GPa to 5 GPa its amplitudes had parabolic plot and temperatures had linear
(that is similar to the Clausius-Clapeyron equation for melting temperature).Comment: 7 pages, 6 figures, 1 tabl
CD133 expression is an independent prognostic marker for low survival in colorectal cancer
Colon cancer cells have previously been demonstrated to contain a subpopulation of CD133+ tumour cells that have the ability to initiate tumour growth and are thus referred to as colon cancer-initiating cells or colon cancer stem cells (CSCs). As CD133 is currently one of the best markers to characterise colon CSCs, we analysed CD133+ tumour cells in colorectal cancer specimens using immunohistochemistry. We show that CD133 detection is specific and that the CD133 antigen is localised on the glandular-luminal surface of colon cancer cells, whereas undifferentiated tumour cells at the front of invasion are CD133â. In addition, CD133+ cells are characterised in situ by lack of CK20 expression, whereas they are positive for EpCAM. Moreover, we show that CD133 expression in colorectal cancer is an independent prognostic marker that correlates with low survival in a stratified patient collective. Our results indicate that in colorectal cancer, the CD133+ tumour cells can be detected by immunohistochemistry, which facilitates their further characterisation in situ
Controllability on infinite-dimensional manifolds
Following the unified approach of A. Kriegl and P.W. Michor (1997) for a
treatment of global analysis on a class of locally convex spaces known as
convenient, we give a generalization of Rashevsky-Chow's theorem for control
systems in regular connected manifolds modelled on convenient
(infinite-dimensional) locally convex spaces which are not necessarily
normable.Comment: 19 pages, 1 figur
TRAIL receptor I (DR4) polymorphisms C626G and A683C are associated with an increased risk for hepatocellular carcinoma (HCC) in HCV-infected patients
<p>Abstract</p> <p>Background</p> <p>Tumour surveillance via induction of TRAIL-mediated apoptosis is a key mechanism, how the immune system prevents malignancy. To determine if gene variants in the TRAIL receptor I (<it>DR4</it>) gene affect the risk of hepatitis C virus (HCV)-induced liver cancer (HCC), we analysed <it>DR4 </it>mutations C626G (rs20575) and A683C (rs20576) in HCV-infected patients with and without HCC.</p> <p>Methods</p> <p>Frequencies of <it>DR4 </it>gene polymorphisms were determined by LightSNiP assays in 159 and 234 HCV-infected patients with HCC and without HCC, respectively. 359 healthy controls served as reference population.</p> <p>Results</p> <p>Distribution of C626G and A683C genotypes were not significantly different between healthy controls and HCV-positive patients without HCC. <it>DR4 </it>variants 626C and 683A occurred at increased frequencies in patients with HCC. The risk of HCC was linked to carriage of the 626C allele and the homozygous 683AA genotype, and the simultaneous presence of the two risk variants was confirmed as independent HCC risk factor by Cox regression analysis (Odds ratio 1.975, 95% CI 1.205-3.236; p = 0.007). Furthermore HCV viral loads were significantly increased in patients who simultaneously carried both genetic risk factors (2.69 ± 0.36 à 10<sup>6</sup> IU/ml vs. 1.81 ± 0.23 à 10<sup>6</sup> IU/ml, p = 0.049).</p> <p>Conclusions</p> <p>The increased prevalence of patients with a 626C allele and the homozygous 683AA genotype in HCV-infected patients with HCC suggests that these genetic variants are a risk factor for HCC in chronic hepatitis C.</p
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