Dibutyltin activates MAP kinases in human natural killer cells, in vitro

Previous studies have shown that dibutyltin (DBT) interferes with the function of human natural killer (NK) cells, diminishing their capacity to destroy tumor cells, in vitro. DBT is a widespread environmental contaminant and has been found in human blood. As NK cells are our primary immune defense against tumor cells, it is important to understand the mechanism by which DBT interferes with their function. The current study examines the effects of DBT exposures on key enzymes in the signaling pathway that regulates NK responsiveness to tumor cells. These include several protein tyrosine kinases (PTKs), mitogen-activated protein kinases (MAPKs), and mitogen-activated protein kinase kinases (MAP2Ks). The results showed that in vitro exposures of NK cells to DBT had no effect on PTKs. However, exposures to DBT for as little as 10 min were able to increase the phosphorylation (activation) of the MAPKs. The DBT-induced activations of these MAPKs appear to be due to DBT-induced activations of the immediate upstream activators of the MAPKs, MAP2Ks. The results suggest that DBT-interference with the MAPK signaling pathway is a consequence of DBT exposures, which could account for DBT-induced decreases in NK function

Myxoid fibroblastic tumor of the maxillary sinus in a 21-month-old child: An unusual diagnosis.

Myxoid tumors of the soft tissue are a heterogeneous group of lesions with significant differences in behavior, from being totally harmless to malignant tumors with metastasizing potential. We describe the unusual case of a 21-month-old boy who developed a paranasal low-grade myxoid neoplasm with recurrent potential. The histological findings showed a proliferation of spindle cells within a vascular and myxoid background. The immunohistochemistry had the features of myofibroblasts and fibroblasts with strong Vimentin and light Smooth Muscle Actin reactivity. Close collaboration between clinician and pathologist is necessary to deal with these unusual lesions to predict their local aggressiveness and long-term behavior. Most of these cellular myxomas have been described in adults, involving primarily the limbs, but this case shows that any localization is possible

Distinguishing among Scalar Field Models of Dark Energy

We show that various scalar field models of dark energy predict degenerate luminosity distance history of the Universe and thus cannot be distinguished by supernovae measurements alone. In particular, models with a vanishing cosmological constant (the value of the potential at its minimum) are degenerate with models with a positive or negative cosmological constant whose magnitude can be as large as the critical density. Adding information from CMB anisotropy measurements does reduce the degeneracy somewhat but not significantly. Our results indicate that a theoretical prior on the preferred form of the potential and the field's initial conditions may allow to quantitatively estimate model parameters from data. Without such a theoretical prior only limited qualitative information on the form and parameters of the potential can be extracted even from very accurate data.Comment: 15 pages, 5 figure

First results from the Very Small Array -- IV. Cosmological parameter estimation

We investigate the constraints on basic cosmological parameters set by the first compact-configuration observations of the Very Small Array (VSA), and other cosmological data sets, in the standard inflationary LambdaCDM model. Using a weak prior 40 < H_0 < 90 km/s/Mpc and 0 < tau < 0.5 we find that the VSA and COBE_DMR data alone produce the constraints Omega_tot = 1.03^{+0.12}_{-0.12}, Omega_bh^2 = 0.029^{+0.009}_{-0.009}, Omega_cdm h^2 = 0.13^{+0.08}_{-0.05} and n_s = 1.04^{+0.11}_{-0.08} at the 68 per cent confidence level. Adding in the type Ia supernovae constraints, we additionally find Omega_m = 0.32^{+0.09}_{-0.06} and Omega_Lambda = 0.71^{+0.07}_{-0.07}. These constraints are consistent with those found by the BOOMERanG, DASI and MAXIMA experiments. We also find that, by combining all the recent CMB experiments and assuming the HST key project limits for H_0 (for which the X-ray plus Sunyaev--Zel'dovich route gives a similar result), we obtain the tight constraints Omega_m=0.28^{+0.14}_{-0.07} and Omega_Lambda= 0.72^{+0.07}_{-0.13}, which are consistent with, but independent of, those obtained using the supernovae data.Comment: 10 pages, 6 figures, MNRAS in pres

Interacting Ghost Dark Energy in Non-Flat Universe

A new dark energy model called "ghost dark energy" was recently suggested to explain the observed accelerating expansion of the universe. This model originates from the Veneziano ghost of QCD. The dark energy density is proportional to Hubble parameter, $\rho_D=\alpha H$, where $\alpha$ is a constant of order $\Lambda_{\rm QCD}^3$ and $\Lambda_{\rm QCD}\sim 100 MeV$ is QCD mass scale. In this paper, we extend the ghost dark energy model to the universe with spatial curvature in the presence of interaction between dark matter and dark energy. We study cosmological implications of this model in detail. In the absence of interaction the equation of state parameter of ghost dark energy is always $w_D > -1$ and mimics a cosmological constant in the late time, while it is possible to have $w_D < -1$ provided the interaction is taken into account. When $k = 0$, all previous results of ghost dark energy in flat universe are recovered. To check the observational consistency, we use Supernova type Ia (SNIa) Gold sample, shift parameter of Cosmic Microwave Background radiation (CMB) and the Baryonic Acoustic Oscillation peak from Sloan Digital Sky Survey (SDSS). The best fit values of free parameter at $1\sigma$ confidence interval are: $\Omega_m^0= 0.35^{+0.02}_{-0.03}$, $\Omega_D^0=0.75_{-0.04}^{+0.01}$ and $b^2=0.08^{+0.03}_{-0.03}$. Consequently the total energy density of universe at present time in this model at 68% level equates to $\Omega_{\rm tot}^0=1.10^{+0.02}_{-0.05}$.Comment: 19 pages, 9 figures. V2: Added comments, observational consequences, references, figures and major corrections. Accepted for publication in General Relativity and Gravitatio

Vector field as a quintessence partner

We derive generic equations for a vector field driving the evolution of flat homogeneous isotropic universe and give a comparison with a scalar filed dynamics in the cosmology. Two exact solutions are shown as examples, which can serve to describe an inflation and a slow falling down of dynamical ``cosmological constant'' like it is given by the scalar quintessence. An attractive feature of vector field description is a generation of ``induced mass'' proportional to a Hubble constant, which results in a dynamical suppression of actual cosmological constant during the evolution.Comment: 14 pages, LaTeX file, iopart class, discussion extended, reference adde

Haploinsufficiency and reduced expression of genes localized to the 8p chromosomal region in human prostate tumors

Cytogenetic and molecular studies have suggested that deletion or rearrangement of sequences that map to the short arm of chromosome 8 may be permissive for tumorigenesis in several organ systems, and in human prostate tumors in particular. In this study, we hypothesized that genes deleted for one copy and localized to the 8p chromosomal region may be transcriptionally down-regulated or ablated in affected human prostate tumor tissues. To test this hypothesis, we used cDNA microarray analysis to determine the transcriptional profiles for 259 transcribed sequences mapping to the 8p chromosomal region for seven human prostate tumor xenografts, completely characterized for numerical and structural alterations on chromosome 8, and five normal human prostate tissues. These experiments identified 33 genes differentially expressed between normal and malignant prostate tissues, the majority of which (28/33, 85%) were transcriptionally down-regulated in malignant compared to normal human prostate tissues. These findings, that haploinsufficiency and transcriptional down-regulation for genes mapping to 8p are largely coincident in human prostate tumors, should provide a powerful tool for the identification of tumor-suppressor genes associated with human prostate cancer initiation and progression. © 2003 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35134/1/10226_ftp.pd

Observational constraints on the braneworld model with brane-bulk energy exchange

We investigate the viability of the braneworld model with energy exchange between the brane and bulk, by using the most recent observational data related to the background evolution. We show that this energy exchange behaves like a source of dark energy and can alter the profile of the cosmic expansion. The new Supernova Type Ia (SNIa) Gold sample, Supernova Legacy Survey (SNLS) data, the position of the acoustic peak at the last scattering surface from the Wilkinson Microwave Anisotropy Probe (WMAP) observations and the baryon acoustic oscillation peak found in the Sloan Digital Sky Survey (SDSS) are used to constrain the free parameters of this model. To infer its consistency with the age of the Universe, we compare the age of old cosmological objects with what computed using the best fit values for the model parameters. At 68% level of confidence, the combination of Gold sample SNIa, Cosmic Microwave Background (CMB) shift parameter and SDSS databases provide $\Omega_m=0.29_{-0.02}^{+0.03}$, $\Omega_{A}=-0.71_{-0.03}^{+0.03}$ and $\mu=-0.40_{-0.26}^{+0.28}$, hence a spatially flat Universe with $\Omega_K=0.00_{-0.04}^{+0.04}$. The same combination with SNLS supernova observation give $\Omega_m=0.27_{-0.02}^{+0.02}$, $\Omega_{A}=-0.74_{-0.02}^{+0.04}$ and $\mu=0.00_{-0.30}^{+0.30}$ consequently provides a spatially flat Universe $\Omega_K=-0.01_{-0.03}^{+0.04}$. These results obviously seem to be compatible with the most recent WMAP results indicating a flat Universe.Comment: 17 pages and 18 figures, V2: Added comments, references, explained some topics related to the matter power spectrum as a robust constraint, accepted for publication in Mon. Not. R. Astron. So

How do parents of children with juvenile idiopathic arthritis (JIA) perceive their therapies?

<p>Abstract</p> <p>Background</p> <p>Complementary and alternative medical (CAM) therapies are commonly used by pediatric patients with chronic medical conditions. Little is known about parents' perceptions of these therapies. This study describes the views of parents of patients with juvenile idiopathic arthritis (JIA) regarding conventional and CAM therapies.</p> <p>Methods</p> <p>Parents of children with JIA seen at a pediatric rheumatology clinic were surveyed between June 1 and July 31, 2007. Questionnaires asked about patients' use of over 75 therapies in the past 30 days, their perceived helpfulness (0 = not helpful; 3 = very helpful), perceived side effects (0 = none; 3 = severe), and whether each therapy would be recommended to other patients with JIA (Yes, No, Not sure).</p> <p>Results</p> <p>Questionnaires were returned by 52/76 (68%) parents; patients' average age was 10.9 years and 87% were Caucasian. Medications were used by 45 (88%) patients; heat (67%) and extra rest (54%) were also commonly used. CAM therapies were used by 48 (92%), e.g., massage (54%), vitamins and other supplements (54%), avoiding foods that worsened pain (35%) and stress management techniques (33%). Among the therapies rated by 3 or more parents, those that scored 2.5 or higher on helpfulness were: biologic medications, methotrexate, naproxen, wheelchairs, orthotics, heat, vitamins C and D, music, support groups and prayer. CAM therapies had 0 median side effects and parents would recommend many of them to other families.</p> <p>Conclusion</p> <p>JIA patients use diverse therapies. Parents report that many CAM therapies are helpful and would recommend them to other parents. These data can be used in counseling patients and guiding future research.</p