2,315 research outputs found
LCK, survivin and PI-3K in the molecular biomarker profiling of oral lichen planus and oral squamous cell carcinoma.
T cell signaling is critical in oral lichen planus (OLP) based on the pathogenesis of this chronic inflammatory autoimmune mucocutaneous lesion. Lck plays a key role in T cell signaling; ultimately this signaling affects other targets such as PI-3K. Excessive activity in PI-3K inhibits apoptosis and promotes uncontrolled cell growth. Molecular biomarker profiling in OLP, Chronic Interface Mucosities (CIM), Epithelial Dysplasia (EpD) and Oral Squamous Cell Carcinoma (SCCA) with application of the principle of biomarker voting may represent a new frontier in the diagnosis, assessment and the arguable debate of OLP transformation to cancer. The presence of Lck, PI-3K and Survivin, a cancer specific anti-apoptotic protein was assessed, using immunohistochemistry and tissue micro-array on patient samples, in OLP, SCCA, CIM and EpD. Lck expression was very high in 78.6 % of OLP patients compared to 3.7% in SCCA; PI-3K was high in 63% of SCCA, 100% of EpD, and 35.7% OLP cases. Survivin was high in 64.3% of OLP cases, 96.3% of SCCA, and 100% of EpD. CIM cases may be slightly different molecularly to OLP. Taken together, our data suggest that biomarker protein voting can be effectively used to isolate high-risk OLP cases. Specifically, we show data with four remarkable cases demonstrating that molecular factors are predictive of histopathology. We conclude that it is safer to treat OLP as premalignant lesions, to adopt aggressive treatment measure in histopathologic described well and moderately differentiated SCCA, and to monitor progress of these diseases molecularly using individualized auto-proteomic approach. The use of Lck inhibitors in OLP management needs to be investigated in the future
A dynamo driven by zonal jets at the upper surface: Applications to giant planets
We present a dynamo mechanism arising from the presence of barotropically
unstable zonal jet currents in a rotating spherical shell. The shear
instability of the zonal flow develops in the form of a global Rossby mode,
whose azimuthal wavenumber depends on the width of the zonal jets. We obtain
self-sustained magnetic fields at magnetic Reynolds numbers greater than 1000.
We show that the propagation of the Rossby waves is crucial for dynamo action.
The amplitude of the axisymmetric poloidal magnetic field depends on the
wavenumber of the Rossby mode, and hence on the width of the zonal jets. We
discuss the plausibility of this dynamo mechanism for generating the magnetic
field of the giant planets. Our results suggest a possible link between the
topology of the magnetic field and the profile of the zonal winds observed at
the surface of the giant planets. For narrow Jupiter-like jets, the poloidal
magnetic field is dominated by an axial dipole whereas for wide Neptune-like
jets, the axisymmetric poloidal field is weak.Comment: published in Icaru
Epidemiology and Control of a Head Louse Outbreak in Ames, Iowa, 1976
At the onset of school in 1976, head lice were recognized by teachers and school nurses in the public and parochial schools in Ames, Iowa. One or more cases were identified from the 9 elementary schools and 3 secondary schools in the community. The greatest prevalence of louse infestations occurred in 2 elementary schools (1 parochial) where 16% and 14%, respectively, of the students were infested. A program was established to screen children and exclude infested individuals from class until they were effectively treated. The community was surveyed to determine the extent of infestation in each household from which at least 1 member was attending school and had a confirmed louse infestation. Data were tabulated on the incidence of louse infestations by school, grade, sex, hair color, hair length, number of persons living in homes where louse infestations were recognized and incomes of families that had infested members. Factors that contributed to louse transmission and an evaluation of an intensive community-wide control program are discussed
Conformational Entropy as a Means to Control the Behavior of Poly(diketoenamine) Vitrimers In and Out of Equilibrium.
Control of equilibrium and non-equilibrium thermomechanical behavior of poly(diketoenamine) vitrimers is shown by incorporating linear polymer segments varying in molecular weight (MW) and conformational degrees of freedom into the dynamic covalent network. While increasing MW of linear segments yields a lower storage modulus at the rubbery plateau after softening above the glass transition (Tg ), both Tg and the characteristic time of stress relaxation are independently governed by the conformational entropy of the embodied linear segments. Activation energies for bond exchange in the solid state are lower for networks incorporating flexible chains; the network topology freezing temperature decreases with increasing MW of flexible linear segments but increases with increasing MW of stiff segments. Vitrimer reconfigurability is therefore influenced not only by the energetics of bond exchange for a given network density, but also the entropy of polymer chains within the network
Bayesian inference on compact binary inspiral gravitational radiation signals in interferometric data
Presented is a description of a Markov chain Monte Carlo (MCMC) parameter
estimation routine for use with interferometric gravitational radiational data
in searches for binary neutron star inspiral signals. Five parameters
associated with the inspiral can be estimated, and summary statistics are
produced. Advanced MCMC methods were implemented, including importance
resampling and prior distributions based on detection probability, in order to
increase the efficiency of the code. An example is presented from an
application using realistic, albeit fictitious, data.Comment: submitted to Classical and Quantum Gravity. 14 pages, 5 figure
The role of the microenvironment in tumor immune surveillance
The evidence appears compelling that the microenvironment, and associated biological cellular and molecular factors, may contribute to the progression of
a variety of tumors. The effects of the microenvironment may directly influence the plasticity of T cell lineages, which was recently discussed (O'Shea &
Paul, 2010 [4]). To review the putative role of the microenvironment in modulating the commitment of tumor immune surveillance, we use the model of
oral premalignant lesions
Comparison of three molecular methods for the detection and speciation of Plasmodium vivax and Plasmodium falciparum
<p>Abstract</p> <p>Background</p> <p>Accurate diagnosis of <it>Plasmodium </it>spp. is essential for the rational treatment of malaria. Despite its many disadvantages, microscopic examination of blood smears remains the current "gold standard" for malaria detection and speciation. PCR assays offer an alternative to microscopy which has been shown to have superior sensitivity and specificity. Unfortunately few comparative studies have been done on the various molecular based speciation methods.</p> <p>Methods</p> <p>The sensitivity, specificity and cost effectiveness of three molecular techniques were compared for the detection and speciation of <it>Plasmodium falciparum </it>and <it>Plasmodium vivax </it>from dried blood spots collected from 136 patients in western Thailand. The results from the three molecular speciation techniques (nested PCR, multiplex PCR, and real-time PCR) were used to develop a molecular consensus (two or more identical PCR results) as an alternative gold standard.</p> <p>Results</p> <p>According to the molecular consensus, 9.6% (13/136) of microscopic diagnoses yielded false negative results. Multiplex PCR failed to detect <it>P. vivax </it>in three mixed isolates, and the nested PCR gave a false positive <it>P. falciparum </it>result in one case. Although the real-time PCR melting curve analysis was the most expensive method, it was 100% sensitive and specific and least time consuming of the three molecular techniques investigated.</p> <p>Conclusion</p> <p>Although microscopy remains the most appropriate method for clinical diagnosis in a field setting, its use as a gold standard may result in apparent false positive results by superior techniques. Future studies should consider using more than one established molecular methods as a new gold standard to assess novel malaria diagnostic kits and PCR assays.</p
Modelling ultrasound-induced mild hyperthermia of hyperplasia in vascular grafts
<p>Abstract</p> <p>Background</p> <p>Expanded polytetrafluoroethylene (ePTFE) vascular grafts frequently develop occlusive neointimal hyperplasia as a result of myofibroblast over-growth, leading to graft failure. ePTFE exhibits higher ultrasound attenuation than native soft tissues. We modelled the selective absorption of ultrasound by ePTFE, and explored the feasibility of preventing hyperplasia in ePTFE grafts by ultrasound heating. Specifically, we simulated the temperature profiles of implanted grafts and nearby soft tissues and blood under ultrasound exposure. The goal was to determine whether ultrasound exposure of an ePTFE graft can generate temperatures sufficient to prevent cell growth on the graft without damaging nearby soft tissues and blood.</p> <p>Methods</p> <p>Ultrasound beams from two transducers (1.5 and 3.2 MHz) were simulated in two graft/tissue models, with and without an intra-graft cellular layer mimicking hyperplasia, using the finite-difference time-domain (FDTD) method. The resulting power deposition patterns were used as a heat source for the Pennes bioheat equation in a COMSOL<sup>® </sup>Multiphysics heat transfer model. 50°C is known to cause cell death and therefore the transducer powers were adjusted to produce a 13°C temperature rise from 37°C in the ePTFE.</p> <p>Results</p> <p>Simulations showed that both the frequency of the transducers and the presence of hyperplasia significantly affect the power deposition patterns and subsequent temperature profiles on the grafts and nearby tissues. While neither transducer significantly raised the temperature of the blood, the 1.5-MHz transducer was less focused and heated larger volumes of the graft and nearby soft tissues than the 3.2-MHz transducer. The presence of hyperplasia had little effect on the blood's temperature, but further increased the temperature of the graft and nearby soft tissues in response to either transducer. Skin cooling and blood flow play a significant role in preventing overheating of the native tissues.</p> <p>Conclusions</p> <p>Modelling shows that ultrasound can selectively heat ePTFE grafts and produce temperatures that cause cell death on the graft. The temperature increase in blood is negligible and that in the adjacent soft tissues may be minimized by skin cooling and using appropriate transducers. Therefore, ultrasound heating may have the potential to reduce neointimal hyperplasia and failure of ePTFE vascular grafts.</p
Pressure-induced phonon frequency shifts in transition-metal nitrides
We report the first experiments on the high pressure phonon spectra of
transition-metal nitrides HfN, ZrN, and NbN, obtained by Raman scattering
measurements. Two pronounced bands, which are related to the acoustic part at
low frequency around 200 cm and the optical part at high frequency
around 550 cm of the phonon spectrum, respectively, shift to high
frequency values with increasing pressure. An analysis of the results allows us
to reproduce the experimental pressure dependence of the superconducting
transition temperature of ZrN and NbN.Comment: 19 pages and 6 figure
Diets high in selenium and isoflavones decrease androgen-regulated gene expression in healthy rat dorsolateral prostate
<p>Abstract</p> <p>Background</p> <p>High dietary intake of selenium or soybean isoflavones reduces prostate cancer risk. These components each affect androgen-regulated gene expression. The objective of this work was to determine the combined effects of selenium and isoflavones on androgen-regulated gene expression in rat prostate.</p> <p>Methods</p> <p>Male Noble rats were exposed from conception until 200 days of age to diets containing an adequate (0.33-0.45 mg/kg diet) or high (3.33-3.45 mg/kg) concentration of selenium as Se-methylselenocysteine and a low (10 mg/kg) or high (600 mg/kg) level of isoflavones in a 2 × 2 factorial design. Gene expression in the dorsolateral prostate was determined for the androgen receptor, for androgen-regulated genes, and for Akr1c9, whose product catalyzes the reduction of dihydrotestosterone to 5alpha-androstane-3alpha, 17beta-diol. Activity of hepatic glutathione peroxidise 1 and of prostatic 5alpha reductase were also assayed.</p> <p>Results</p> <p>There were no differences due to diet in activity of liver glutathione peroxidase activity. Total activity of 5alpha reductase in prostate was significantly lower (<it>p </it>= 0.007) in rats fed high selenium/high isoflavones than in rats consuming adequate selenium/low isoflavones. High selenium intake reduced expression of the androgen receptor, Dhcr24 (24-dehydrocholesterol reductase), and Abcc4 (ATP-binding cassette sub-family C member 4). High isoflavone intake decreased expression of Facl3 (fatty acid CoA ligase 3), Gucy1a3 (guanylate cyclase alpha 3), and Akr1c9. For Abcc4 the combination of high selenium/high isoflavones had a greater inhibitory effect than either treatment alone. The effects of selenium on gene expression were always in the direction of chemoprevention</p> <p>Conclusion</p> <p>These results suggest that combined intake of high selenium and high isoflavones may achieve a greater chemopreventive effect than either compound supplemented individually.</p
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