698 research outputs found
Restoration of diaphragmatic function after diaphragm reinnervation by inferior laryngeal nerve; experimental study in rabbits
OBJECTIVES: To assess the possibilities of reinnervation in a paralyzed hemidiaphragm via an anastomosis between phrenic nerve and inferior laryngeal nerve in rabbits. Reinnervation of a paralyzed diaphragm could be an alternative to treat patients with ventilatory insufficiency due to upper cervical spine injuries. MATERIAL AND METHOD: Rabbits were divided into five groups of seven rabbits each. Groups I and II were respectively the healthy and the denervated control groups. The 3 other groups were all reinnervated using three different surgical procedures. In groups III and IV, phrenic nerve was respectively anastomosed with the abductor branch of the inferior laryngeal nerve and with the trunk of the inferior laryngeal nerve. In group V, the fifth and fourth cervical roots were respectively anastomosed with the abductor branch of the inferior laryngeal nerve and with the nerve of the sternothyroid muscle (originating from the hypoglossal nerve). Animals were evaluated 4 months later using electromyography, transdiaphragmatic pressure measurements, sonomicrometry and histological examination. RESULTS: A poor inspiratory activity was found in quiet breathing in the reinnervated groups, with an increasing pattern of activity during effort. In the reinnervated groups, transdiaphragmatic pressure measurements and sonomicrometry were higher in group III with no significant differencewith groups IV and V. CONCLUSION: Inspiratory contractility of an hemidiaphragm could be restored with immediate anastomosis after phrenic nerve section between phrenic nerve and inferior laryngeal nerve
Screening and brief interventions for hazardous and harmful alcohol use among patients with active tuberculosis attending primary care clinics in South Africa: a cluster randomized controlled trial protocol
<p>Abstract</p> <p>Background</p> <p>In 2008 the World Health Organization (WHO) reported that South Africa had the highest tuberculosis (TB) incidence in the world. This high incidence rate is linked to a number of factors, including HIV co-infection and alcohol use disorders. The diagnosis and treatment package for TB and HIV co-infection is relatively well established in South Africa. However, because alcohol use disorders may present more insidiously, making it difficult to diagnose, those patients with active TB and misusing alcohol are not easily cured from TB. With this in mind, the primary purpose of this cluster randomized controlled trial is to provide screening for alcohol misuse and to test the efficacy of brief interventions in reducing alcohol intake in those patients with active TB found to be misusing alcohol in primary health care clinics in three provinces in South Africa.</p> <p>Methods/Design</p> <p>Within each of the three selected health districts with the highest TB burden in South Africa, 14 primary health care clinics with the highest TB caseloads will be selected. Those agreeing to participate will be stratified according to TB treatment caseload and the type of facility (clinic or community health centre). Within strata from 14 primary care facilities, 7 will be randomly selected into intervention and 7 to control study clinics (42 clinics, 21 intervention clinics and 21 control clinics). At the clinic level systematic sampling will be used to recruit newly diagnosed TB patients. Those consenting will be screened for alcohol misuse using the AUDIT. Patients who screen positive for alcohol misuse over a 6-month period will be given either a brief intervention based on the Information-Motivation-Behavioural Skills (IMB) Model or an alcohol use health education leaflet.</p> <p>A total sample size of 520 is expected.</p> <p>Discussion</p> <p>The trial will evaluate the impact of alcohol screening and brief interventions for patients with active TB in primary care settings in South Africa. The findings will impact public health and will enable the health ministry to formulate policy related to comprehensive treatment for TB and alcohol misuse, which will result in reduction in alcohol use and ultimately improve the TB cure rates.</p> <p>Trial registration number</p> <p>PACTR: <a href="http://apps.who.int/trialsearch/trial.aspx?trialid=PACTR201105000297151">PACTR201105000297151</a></p
f(R) theories
Over the past decade, f(R) theories have been extensively studied as one of
the simplest modifications to General Relativity. In this article we review
various applications of f(R) theories to cosmology and gravity - such as
inflation, dark energy, local gravity constraints, cosmological perturbations,
and spherically symmetric solutions in weak and strong gravitational
backgrounds. We present a number of ways to distinguish those theories from
General Relativity observationally and experimentally. We also discuss the
extension to other modified gravity theories such as Brans-Dicke theory and
Gauss-Bonnet gravity, and address models that can satisfy both cosmological and
local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in
Relativity, Published version, Comments are welcom
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
HER2 induced EMT and tumorigenicity in breast epithelial progenitor cells is inhibited by coexpression of EGFR.
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This article is open access.The members of the epidermal growth factor receptor (EGFR) kinase family are important players in breast morphogenesis and cancer. EGFR2/HER2 and EGFR expression have a prognostic value in certain subtypes of breast cancer such as HER2-amplified, basal-like and luminal type B. Many clinically approved small molecular inhibitors and monoclonal antibodies have been designed to target HER2, EGFR or both. There is, however, still limited knowledge on how the two receptors are expressed in normal breast epithelium, what effects they have on cellular differentiation and how they participate in neoplastic transformation. D492 is a breast epithelial cell line with stem cell properties that can undergo epithelial to mesenchyme transition (EMT), generate luminal- and myoepithelial cells and form complex branching structures in three-dimensional (3D) culture. Here, we show that overexpression of HER2 in D492 (D492(HER2)) resulted in EMT, loss of contact growth inhibition and increased oncogenic potential in vivo. HER2 overexpression, furthermore, inhibited endogenous EGFR expression. Re-introducing EGFR in D492(HER2) (D492(HER2/EGFR)) partially reversed the mesenchymal state of the cells, as an epithelial phenotype reappeared both in 3D cultures and in vivo. The D492(HER2/EGFR) xenografts grow slower than the D492(HER2) tumors, while overexpression of EGFR alone (D492(EGFR)) was not oncogenic in vivo. Consistent with the EGFR-mediated epithelial phenotype, overexpression of EGFR drove the cells toward a myoepithelial phenotype in 3D culture. The effect of two clinically approved anti-HER2 and EGFR therapies, trastuzumab and cetuximab, was tested alone and in combination on D492(HER2) xenografts. While trastuzumab had a growth inhibitory effect compared with untreated control, the effect of cetuximab was limited. When administered in combination, the growth inhibitory effect of trastuzumab was less pronounced. Collectively, our data indicate that in HER2-overexpressing D492 cells, EGFR can behave as a tumor suppressor, by pushing the cells towards epithelial differentiation.Landspitali University Hospital Science Fund,
University of Iceland Research Fund, Science and Technology Policy Council Research
Fund and Grant of Excellence, ‘Göngum saman’, a supporting group for breast cancer
research in Iceland
Effects and feasibility of a standardised orientation and mobility training in using an identification cane for older adults with low vision: design of a randomised controlled trial
<p>Abstract</p> <p>Background</p> <p>Orientation and mobility training (O&M-training) in using an identification cane, also called symbol cane, is provided to people with low vision to facilitate independent participation in the community. In The Netherlands this training is mainly practice-based because a standardised and validly evaluated O&M-training in using the identification cane is lacking. Recently a standardised O&M-training in using the identification cane was developed. This training consists of two face-to-face sessions and one telephone session during which, in addition to usual care, the client's needs regarding mobility are prioritised, and cognitive restructuring techniques, action planning and contracting are applied to facilitate the use of the cane. This paper presents the design of a randomised controlled trial aimed to evaluate this standardised O&M-training in using the identification cane in older adults with low vision.</p> <p>Methods/design</p> <p>A parallel group randomised controlled trial was designed to compare the standardised O&M-training with usual care, i.e. the O&M-training commonly provided by the mobility trainer. Community-dwelling older people who ask for support at a rehabilitation centre for people with visual impairment and who are likely to receive an O&M-training in using the identification cane are included in the trial (N = 190). The primary outcomes of the effect evaluation are ADL self care and visual functioning with respect to distance activities and mobility. Secondary outcomes include quality of life, feelings of anxiety, symptoms of depression, fear of falling, and falls history. Data for the effect evaluation are collected by means of telephone interviews at baseline, and at 5 and 17 weeks after the start of the O&M-training. In addition to an effect evaluation, a process evaluation to study the feasibility of the O&M-training is carried out.</p> <p>Discussion</p> <p>The screening procedure for eligible participants started in November 2007 and will continue until October 2009. Preliminary findings regarding the evaluation are expected in the course of 2010. If the standardised O&M-training is more effective than the current O&M-training or, in case of equal effectiveness, is considered more feasible, the training will be embedded in the Dutch national instruction for mobility trainers.</p> <p>Trial registration</p> <p>ClinicalTrials.gov NCT00946062</p
NICE : A Computational solution to close the gap from colour perception to colour categorization
The segmentation of visible electromagnetic radiation into chromatic categories by the human visual system has been extensively studied from a perceptual point of view, resulting in several colour appearance models. However, there is currently a void when it comes to relate these results to the physiological mechanisms that are known to shape the pre-cortical and cortical visual pathway. This work intends to begin to fill this void by proposing a new physiologically plausible model of colour categorization based on Neural Isoresponsive Colour Ellipsoids (NICE) in the cone-contrast space defined by the main directions of the visual signals entering the visual cortex. The model was adjusted to fit psychophysical measures that concentrate on the categorical boundaries and are consistent with the ellipsoidal isoresponse surfaces of visual cortical neurons. By revealing the shape of such categorical colour regions, our measures allow for a more precise and parsimonious description, connecting well-known early visual processing mechanisms to the less understood phenomenon of colour categorization. To test the feasibility of our method we applied it to exemplary images and a popular ground-truth chart obtaining labelling results that are better than those of current state-of-the-art algorithms
Coordinated spatial and temporal expression of Hox genes during embryogenesis in the acoel Convolutriloba longifissura
Background: Hox genes are critical for patterning the bilaterian anterior-posterior axis. The evolution of their clustered genomic arrangement and ancestral function has been debated since their discovery. As acoels appear to represent the sister group to the remaining Bilateria (Nephrozoa), investigating Hox gene expression will provide an insight into the ancestral features of the Hox genes in metazoan evolution. Results: We describe the expression of anterior, central and posterior class Hox genes and the ParaHox ortholog Cdx in the acoel Convolutriloba longifissura. Expression of all three Hox genes begins contemporaneously after gastrulation and then resolves into staggered domains along the anterior-posterior axis, suggesting that the spatial coordination of Hox gene expression was present in the bilaterian ancestor. After early surface ectodermal expression, the anterior and central class genes are expressed in small domains of putative neural precursor cells co-expressing ClSoxB1, suggesting an evolutionary early function of Hox genes in patterning parts of the nervous system. In contrast, the expression of the posterior Hox gene is found in all three germ layers in a much broader posterior region of the embryo. Conclusion: Our results suggest that the ancestral set of Hox genes was involved in the anteriorposterior patterning of the nervous system of the last common bilaterian ancestor and were later co-opted for patterning in diverse tissues in the bilaterian radiation. The lack of temporal colinearity of Hox expression in acoels may be due to a loss of genomic clustering in this clade or, alternatively, temporal colinearity may have arisen in conjunction with the expansion of the Hox cluster in the Nephrozoa
Theology and cosmology beyond the Big Bang theory
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