155 research outputs found
Effective fermion couplings in warped 5D Higgsless theories
We consider a five dimensional SU(2) gauge theory with fermions in the bulk
and with additional SU(2) and U(1) kinetic terms on the branes. The electroweak
breaking is obtained by boundary conditions. After deconstruction, fermions in
the bulk are eliminated by using their equations of motion. In this way
Standard Model fermion mass terms and direct couplings to the internal gauge
bosons of the moose are generated. The presence of these new couplings gives a
new contribution to the epsilon_3 parameter in addition to the gauge boson
term. This allows the possibility of a cancellation between the two
contributions, which can be local (site by site) or global. Going back to the
continuum, we show that the implementation of local cancellation in any generic
warped metric leaves massless fermions. This is due to the presence of one
horizon on the infrared brane. However we can require a global cancellation of
the new physics contributions to the epsilon_3 parameter. This fixes relations
among the warp factor and the parameters of the fermion and gauge sectors.Comment: Latex file, 23 pages, 1 eps figur
Gauge invariant formulation of strong WW scattering
Models of strong scattering in the -wave can be represented in a
gauge invariant fashion by defining an effective scalar propagator that
represents the strong scattering dynamics. The \sigma(qq \ra qqWW) signal may
then be computed in U-gauge from the complete set of tree amplitudes, just as
in the standard model, without using the effective approximation (EWA). The
U-gauge ``transcription'' has a wider domain of validity than the EWA, and it
provides complete distributions for the final state quanta, including
experimentally important jet distributions that cannot be obtained from the
EWA. Starting from the usual formulation in terms of unphysical Goldstone boson
scattering amplitudes, the U-gauge transcription is verified by using BRS
invariance to construct the complete set of gauge and Goldstone boson
amplitudes in gauge.Comment: single LaTeX file, no figures, 12 page
Possible added value of thyroglobulin antibody (TgAb) testing in the evaluation of thyroidal status of subjects with overweight or obesity
Purpose: An increase in serum TSH concentrations in the absence of thyroid disease, named isolated hyperthyrotropinemia, is frequently observed in subjects with obesity. It is directly associated with body mass index, and it is reversible following weight loss. Autoimmune hypothyroidism is frequently associated with obesity, it is usually progressive and needs replacement treatment with L-thyroxine. The aim of this study was to investigate the role of thyroglobulin antibodies (TgAb) to define the thyroidal status in subjects with overweight or obesity.
Methods: This is a retrospective study including 749 consecutive adult patients with overweight or obesity. Of those, 76 were excluded from the analysis due to hyperthyroidism, previous thyroidectomy or radioiodine therapy for hyperthyroidism, hemiagenesis or drug-induced hypothyroidism. Serum thyrotropin (TSH), free thyroxine (FT4), free 3,5,3'-triiodothyronine (FT3), TgAb and thyroperoxidase antibodies (TPOAb) were measured in all patients.
Results: Out of 673 patients, 408 did not have thyroid disease. Among patients with thyroid disease (n = 265), 130 had nodular disease with no humoral signs of thyroid autoimmunity and 135 (20%) had autoimmune thyroiditis, defined by the presence of TPOAb and/or TgAb. The prevalence of hyperthyrotropinemia, either directly measured or presumed based on L-thyroxine treatment at the time of data collection, was 63.9% in patients with both TgAb and TPOAb, 47.1% in those with isolated positivity of TPOAb, 42.8% in patients with isolated positivity of TgAb, and 14.5% in those with no detectable TgAb or TPOAb.
Conclusions: Our results confirm a high prevalence of autoimmune thyroiditis (20%) in patients with obesity. TgAb may be associated with hypothyroidism in the absence of TPOAb. TgAb measurement may turn helpful to unravel a proportion of subjects that may have or may develop primary hypothyroidism requiring specific substitutive treatment
Relation of gallbladder function and Helicobacter pylori infection to gastric mucosa inflammation in patients with symptomatic cholecystolithiasis
Background. Inflammatory alterations of the gastric mucosa are commonly caused by Helicobacter pylori (Hp) infection in patients with symptomatic gallstone disease. However, the additional pathogenetic role of an impaired gallbladder function leading to an increased alkaline duodenogastric reflux is controversially discussed. Aim:To investigate the relation of gallbladder function and Hp infection to gastric mucosa inflammation in patients with symptomatic gallstones prior to cholecystectomy. Patients: Seventy-three patients with symptomatic gallstones were studied by endoscopy and Hp testing. Methods: Gastritis classification was performed according to the updated Sydney System and gallbladder function was determined by total lipid concentration of gallbladder bile collected during mainly laparoscopic cholecystectomy. Results: Fifteen patients revealed no, 39 patients mild, and 19 moderate to marked gastritis. No significant differences for bile salts, phospholipids, cholesterol, or total lipids in gallbladder bile were found between these three groups of patients. However, while only 1 out of 54 (< 2%) patients with mild or no gastritis was found histologically positive for Hp, this infection could be detected in 14 (74%) out of 19 patients with moderate to marked gastritis. Conclusion: Moderate to marked gastric mucosa inflammation in gallstone patients is mainly caused by Hp infection, whereas gallbladder function is not related to the degree of gastritis. Thus, an increased alkaline duodenogastric reflux in gallstone patients seems to be of limited pathophysiological relevance. Copyright (c) 2006 S. Karger AG, Basel
hERG1 Channels Regulate VEGF-A Secretion in Human Gastric Cancer: Clinicopathological Correlations and Therapeutical Implications
Purpose: hERG1 channels are aberrantly expressed in several types of human cancers, where they affect different aspects of cancer cell behavior. A thorough analysis of the functional role and clinical significance of hERG1 channels in gastric cancer is still lacking. Experimental Design: hERG1 expression was tested in a wide (508 samples) Italian cohort of surgically resected patients with gastric cancer, by immunohistochemistry and real-time quantitative PCR. The functional link between hERG1 and the VEGF-A was studied in different gastric cancer cell lines. The effects of hERG1 and VEGF-A inhibition were evaluated in vivo in xenograft mouse models. Results: hERG1 was positive in69% of the patients and positivity correlated with Lauren's intestinal type, fundus localization of the tumor, G1-G2 grading, I and II tumor-node-metastasis stage, and VEGF-A expression. hERG1 activity modulated VEGF-A secretion, through an AKT-dependent regulation of the transcriptional activity of the hypoxia inducible factor. Treatment of immunodeficient mice xenografted with human gastric cancer cells, with a combination of hERG1 blockers and anti-VEGF-A antibodies, impaired tumor growth more than single-drug treatments. Conclusion: Our results show that hERG1 (i) is aberrantly expressed in human gastric cancer since its early stages; (ii) drives an intracellular pathway leading to VEGF-A secretion; (iii) can be exploited to identify a gastric cancer patients' group where a combined treatment with antiangiogenic drugs and noncardiotoxic hERG1 inhibitors could be proposed. Ā© 2014 American Association for Cancer Research
On The Renormalization of Two-Higgs-Doublet Models
We perform the complete one-loop renormalization of a general
two-Higgs-doublet model. We present all the vertices for this model including
the ones in the scalar sector and calculate all the counterterms of the theory.Comment: 48 pages, 2 figures and 2 table
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