12,964 research outputs found
Metallopanstimulin as a marker for head and neck cancer
BACKGROUND: Metallopanstimulin (MPS-1) is a ribosomal protein that is found in elevated amounts in the sera of patients with head and neck squamous cell carcinoma (HNSCC). We used a test, denoted MPS-H, which detects MPS-1 and MPS-1-like proteins, to determine the relationship between MPS-H serum levels and clinical status of patients with, or at risk for, HNSCC. PATIENTS AND METHODS: A total of 125 patients were prospectively enrolled from a university head and neck oncology clinic. Participants included only newly diagnosed HNSCC patients. Two control groups, including 25 non-smokers and 64 smokers, were studied for comparison. A total of 821 serum samples collected over a twenty-four month period were analyzed by the MPS-H radioimmunoassay. RESULTS: HNSCC, non-smokers, and smokers had average MPS-H values of 41.5 ng/mL, 10.2 ng/mL, and 12.8 ng/mL, respectively (p = 0.0001). CONCLUSION: We conclude that MPS-1 and MPS-1-like proteins are elevated in patients with HNSCC, and that MPS-H appears to be a promising marker of presence of disease and response to treatment in HNSCC patients
Stochastic Processes Crossing from Ballistic to Fractional Diffusion with Memory: Exact Results
We address the now classical problem of a diffusion process that crosses over
from a ballistic behavior at short times to a fractional diffusion (sub- or
super-diffusion) at longer times. Using the standard non-Markovian diffusion
equation we demonstrate how to choose the memory kernel to exactly respect the
two different asymptotics of the diffusion process. Having done so we solve for
the probability distribution function (pdf) as a continuous function which
evolves inside a ballistically expanding domain. This general solution agrees
for long times with the pdf obtained within the continuous random walk approach
but it is much superior to this solution at shorter times where the effect of
the ballistic regime is crucial
Two-Frequency Jahn-Teller Systems in Circuit QED
We investigate the simulation of Jahn-Teller models with two non-degenerate
vibrational modes using a circuit QED architecture. Typical Jahn-Teller systems
are anisotropic and require at least a two-frequency description. The proposed
simulator consists of two superconducting lumped-element resonators interacting
with a common flux qubit in the ultrastrong coupling regime. We translate the
circuit QED model of the system to a two-frequency Jahn-Teller Hamiltonian and
calculate its energy eigenvalues and the emission spectrum of the cavities. It
is shown that the system can be systematically tuned to an effective single
mode Hamiltonian from the two-mode model by varying the coupling strength
between the resonators. The flexibility in manipulating the parameters of the
circuit QED simulator permits isolating the effective single frequency and pure
two-frequency effects in the spectral response of Jahn-Teller systems.Comment: 8 pages, 4 figures, figures revise
Symbolic Reachability Analysis of B through ProB and LTSmin
We present a symbolic reachability analysis approach for B that can provide a
significant speedup over traditional explicit state model checking. The
symbolic analysis is implemented by linking ProB to LTSmin, a high-performance
language independent model checker. The link is achieved via LTSmin's PINS
interface, allowing ProB to benefit from LTSmin's analysis algorithms, while
only writing a few hundred lines of glue-code, along with a bridge between ProB
and C using ZeroMQ. ProB supports model checking of several formal
specification languages such as B, Event-B, Z and TLA. Our experiments are
based on a wide variety of B-Method and Event-B models to demonstrate the
efficiency of the new link. Among the tested categories are state space
generation and deadlock detection; but action detection and invariant checking
are also feasible in principle. In many cases we observe speedups of several
orders of magnitude. We also compare the results with other approaches for
improving model checking, such as partial order reduction or symmetry
reduction. We thus provide a new scalable, symbolic analysis algorithm for the
B-Method and Event-B, along with a platform to integrate other model checking
improvements via LTSmin in the future
Immunological basis of differences in disease resistance in the chicken
Genetic resistance to diseases is a multigenic trait governed mainly by the immune system and its interactions with many physiologic and environmental factors. In the adaptive immunity, T cell and B cell responses, the specific recognition of antigens and interactions between antigen presenting cells, T cells and B cells are crucial. It occurs through a network of mediator proteins such as the molecules of the major histocompatibility complex (MHC), T cell receptors, immunoglobulins and secreted proteins such as the cytokines and antibodies. The diversity of these proteins that mainly is due to an intrinsic polymorphism of the genes causes phenotypic variation in disease resistance. The well-known linkage of MHC polymorphism and Marek's disease resistance difference represents a classic model revealing immunological factors in resistance differences and diversity of mediator molecules. The molecular bases in any resistance variation to infectious pathogens are vaguely understood. This paper presents a review of the major immune mediators involved in resistance and susceptibility to infectious diseases and their functional mechanisms in the chicken. The genetic interaction of disease resistance with production traits and the environment is mentioned
Biaxial nematic phases in fluids of hard board-like particles
We use density-functional theory, of the fundamental-measure type, to study
the relative stability of the biaxial nematic phase, with respect to
non-uniform phases such as smectic and columnar, in fluids made of hard
board-like particles with sizes . A
restricted-orientation (Zwanzig) approximation is adopted. Varying the ratio
while keeping , we
predict phase diagrams for various values of which include all the
uniform phases: isotropic, uniaxial rod- and plate-like nematics, and biaxial
nematic. In addition, spinodal instabilities of the uniform phases with respect
to fluctuations of the smectic, columnar and plastic-solid type, are obtained.
In agreement with recent experiments, we find that the biaxial nematic phase
begins to be stable for . Also, as predicted by previous
theories and simulations on biaxial hard particles, we obtain a region of
biaxility centred on which widens as
increases. For \kappa_2\agt 5 the region of the
packing-fraction vs. phase diagrams exhibits interesting topologies
which change qualitatively with . We have found that an increasing
biaxial shape anisotropy favours the formation of the biaxial nematic phase.
Our study is the first to apply FMT theory to biaxial particles and, therefore,
it goes beyond the second-order virial approximation. Our prediction that the
phase diagram must be asymmetric is a genuine result of the present approach,
which is not accounted for by previous studies based on second-order theories.Comment: Preprint format. 18 pages, 5 figure
Distinct RNA profiles in subpopulations of extracellular vesicles: apoptotic bodies, microvesicles and exosomes
Introduction: In recent years, there has been an exponential increase in the number of studies aiming to understand the biology of exosomes, as well as other extracellular vesicles. However, classification of membrane vesicles and the appropriate protocols for their isolation are still under intense discussion and investigation. When isolating vesicles, it is crucial to use systems that are able to separate them, to avoid cross-contamination. Method: EVs released from three different kinds of cell lines: HMC-1, TF-1 and BV-2 were isolated using two centrifugation-based protocols. In protocol 1, apoptotic bodies were collected at 2,000×g, followed by filtering the supernatant through 0.8 µm pores and pelleting of microvesicles at 12,200×g. In protocol 2, apoptotic bodies and microvesicles were collected together at 16,500×g, followed by filtering of the supernatant through 0.2 µm pores and pelleting of exosomes at 120,000×g. Extracellular vesicles were analyzed by transmission electron microscopy, flow cytometry and the RNA profiles were investigated using a Bioanalyzer®. Results: RNA profiles showed that ribosomal RNA was primary detectable in apoptotic bodies and smaller RNAs without prominent ribosomal RNA peaks in exosomes. In contrast, microvesicles contained little or no RNA except for microvesicles collected from TF-1 cell cultures. The different vesicle pellets showed highly different distribution of size, shape and electron density with typical apoptotic body, microvesicle and exosome characteristics when analyzed by transmission electron microscopy. Flow cytometry revealed the presence of CD63 and CD81 in all vesicles investigated, as well as CD9 except in the TF-1-derived vesicles, as these cells do not express CD9. Conclusions: Our results demonstrate that centrifugation-based protocols are simple and fast systems to distinguish subpopulations of extracellular vesicles. Different vesicles show different RNA profiles and morphological characteristics, but they are indistinguishable using CD63-coated beads for flow cytometry analysis
Whole genome sequencing-based mapping and candidate identification of mutations from fixed zebrafish tissue
As forward genetic screens in zebrafish become more common, the number of mutants that cannot be identified by gross morphology or through transgenic approaches, such as many nervous system defects, has also increased. Screening for these difficult-to-visualize phenotypes demands techniques such as whole-mount in situ hybridization (WISH) or antibody staining, which require tissue fixation. To date, fixed tissue has not been amenable for generating libraries for whole genome sequencing (WGS). Here, we describe a method for using genomic DNA from fixed tissue and a bioinformatics suite for WGS-based mapping of zebrafish mutants. We tested our protocol using two known zebrafish mutant alleles, gpr126st49 and egr2bfh227, both of which cause myelin defects. As further proof of concept we mapped a novel mutation, stl64, identified in a zebrafish WISH screen for myelination defects. We linked stl64 to chromosome 1 and identified a candidate nonsense mutation in the F-box and WD repeat domain containing 7 (fbxw7) gene. Importantly, stl64 mutants phenocopy previously described fbxw7vu56 mutants, and knockdown of fbxw7 in wild-type animals produced similar defects, demonstrating that stl64 disrupts fbxw7. Together, these data show that our mapping protocol can map and identify causative lesions in mutant screens that require tissue fixation for phenotypic analysis
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