298 research outputs found

    A Stealth Supersymmetry Sampler

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    The LHC has strongly constrained models of supersymmetry with traditional missing energy signatures. We present a variety of models that realize the concept of Stealth Supersymmetry, i.e. models with R-parity in which one or more nearly-supersymmetric particles (a "stealth sector") lead to collider signatures with only a small amount of missing energy. The simplest realization involves low-scale supersymmetry breaking, with an R-odd particle decaying to its superpartner and a soft gravitino. We clarify the stealth mechanism and its differences from compressed supersymmetry and explain the requirements for stealth models with high-scale supersymmetry breaking, in which the soft invisible particle is not a gravitino. We also discuss new and distinctive classes of stealth models that couple through a baryon portal or Z' gauge interactions. Finally, we present updated limits on stealth supersymmetry in light of current LHC searches.Comment: 45 pages, 16 figure

    Effect of prenatal glucocorticoid treatment on size at birth among infants born at term gestation

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    ObjectiveTo determine whether prenatal treatment with a single course of glucocorticoids (GCs) affects size at birth among full-term infants independent of fetal size before GC administration or exposure to preterm labor (PTL).Study designIn all, 105 full-term infants were recruited into three study groups (30 GC treated; 60 controls matched for gestational age (GA) at birth and sex; and 15 PTL controls without GC exposure). Size of the infants was estimated before treatment using two-dimensional (2D) ultrasound and by direct measurement at birth.ResultsLength, weight and head circumference at birth were smaller among GC-treated infants compared with matched controls (P's<0.01), although fetal size did not differ before treatment (P's>0.2). Exposure to PTL did not account for this effect.ConclusionsPrenatal treatment with a single course of GCs was associated with a reduction in size at birth among infants born at term gestation. This effect cannot be explained by differences in fetal size before treatment or exposure to PTL

    Asymmetry of Early Endosome Distribution in C. elegans Embryos

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    development, we examined the distribution and dynamics of early endosomes (EEs) in embryos.EEs are primarily found at the cell periphery with an initially uniform distribution after fertilization. Strikingly, we find that during the first cell cycle, EEA-1 positive EEs become enriched at the anterior cortex. In contrast, the Golgi compartment shows no asymmetry in distribution. Asymmetric enrichment of EEs depends on acto-myosin contractility and embryonic PAR polarity. In addition to their localization at the cortex, EEs are also found around the centrosome. These EEs move rapidly (1.3um/s) from the cortex directly to the centrosome, a speed comparable to that of the minus end directed motor dynein.We speculate that the asymmetry of early endosomes might play a role in cell asymmetries or fate decisions

    Acute atomoxetine treatment of younger and older children with ADHD: A meta-analysis of tolerability and efficacy

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    <p>Abstract</p> <p>Background</p> <p>Atomoxetine is FDA-approved as a treatment of attention-deficit/hyperactivity disorder (ADHD) in patients aged 6 years to adult. Among pediatric clinical trials of atomoxetine to date, six with a randomized, double-blind, placebo-controlled design were used in this meta-analysis. The purpose of this article is to describe and compare the treatment response and tolerability of atomoxetine between younger children (6–7 years) and older children (8–12 years) with ADHD, as reported in these six acute treatment trials.</p> <p>Methods</p> <p>Data from six clinical trials of 6–9 weeks duration were pooled, yielding 280 subjects, ages 6–7 years, and 860 subjects, ages 8–12 years with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)-diagnosed ADHD. Efficacy was analyzed using the ADHD Rating Scale-IV (ADHD-RS), Conners' Parent Rating Scale-revised (CPRS-R:S), and the Clinical Global Impression of ADHD Severity (CGI-ADHD-S).</p> <p>Results</p> <p>Atomoxetine was superior to placebo in both age categories for mean (SD) change in ADHD-RS total, total T, and subscale scores; 3 CPRS-R:S subscales; and CGI-ADHD-S from baseline. Although there were no significant treatment differentials between the age groups for these efficacy measures, the age groups themselves, regardless of treatment, were significantly different for ADHD-RS total (younger: ATX = -14.2 [13.8], PBO = -4.6 [10.4]; older: ATX = -15.4 [13.2], PBO = -7.3 [12.0]; p = .001), total T (younger: ATX = -15.2 [14.8], PBO = -4.9 [11.2]; older: ATX = -16.4 [14.6], PBO = -7.9 [13.1]; p = .003), and subscale scores (Inattentive: younger: ATX = -7.2 [7.5], PBO = -2.4 [5.7]; older: ATX = -8.0 [7.4], PBO = -3.9 [6.7]; p = .043; Hyperactive/Impulsive: younger: ATX = -7.0 [7.2], PBO = -2.1 [5.4]; older: ATX = -7.3 [7.0], PBO = -3.4 [6.3]; p < .001), as well as the CGI-ADHD-S score (younger: ATX = -1.2 [1.3], PBO = -0.5 [0.9]; older: ATX = -1.4 [1.3], PBO = -0.7 [1.1]; p = .010). Although few subjects discontinued from either age group due to adverse events, a significant treatment-by-age-group interaction was observed for abdominal pain (younger: ATX = 19%, PBO = 6%; older: ATX = 15%, PBO = 13%; p = .044), vomiting (younger: ATX = 14%, PBO = 2%; older: ATX = 9%, PBO = 6%; p = .053), cough (younger: ATX = 10%, PBO = 6%; older: ATX = 3%, PBO = 9%; p = .007), and pyrexia (younger: ATX = 5%, PBO = 2%; older: ATX = 3%, PBO = 5%; p = .058).</p> <p>Conclusion</p> <p>Atomoxetine is an effective and generally well-tolerated treatment of ADHD in both younger and older children as assessed by three recognized measures of symptoms in six controlled clinical trials.</p> <p>Trial Registration</p> <p>Not Applicable.</p

    Evaluation of the in vitro skin permeation of antiviral drugs from penciclovir 1% cream and acyclovir 5% cream used to treat herpes simplex virus infection

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    <p>Abstract</p> <p>Background</p> <p>Herpes simplex virus infection (HSV) is a common and ubiquitous infection of the skin which causes mucocutaneous lesions called cold sores (herpes labialis) or fever blisters. It is estimated that approximately 80% of the population worldwide are carriers of the Herpes simplex virus, approximately 40% suffer from recurrent recurrent infections. This study evaluates the <it>in vitro </it>skin permeation and penetration of penciclovir and acyclovir from commercialized creams for the treatment of herpes labialis (cold sores), using non viable excised human abdominal skin samples, which were exposed to 5 mg/cm<sup>2 </sup>of acyclovir 5% cream or penciclovir 1% cream.</p> <p>Methods</p> <p>After 24 h of cream application, excess cream was washed off and layers of stratum corneum were removed by successive tape stripping. Amounts of active ingredients having penetrated through the skin were measured, as well as the amounts in the washed-off cream, in skin strips and creams remaining in the skin. Molecular modelling was used to evaluate physico-chemical differences between the drugs. Western blot analysis enabled to determine whether the marker of basal cells keratin 5 could be detected in the various tape strips.</p> <p>Results</p> <p>Application of penciclovir 1% cream yielded higher concentration of drug in the deeper layers of the epidermis as well as a higher drug flux through the skin. Molecular modelling showed two higher hydrophobic moieties for acyclovir. Presence of the basal cell marker keratin 5 was underscored in the deeper tape strips from the skin, giving evidence that both drugs can reach their target cells.</p> <p>Conclusion</p> <p>Penciclovir 1% cream has the tendency to facilitate the diffusion of the drug through the stratum corneum into the deeper epidermis layers, in which it could reach the target basal cells at effective therapeutical concentration. The small difference in the surface properties between both molecules might also contribute to favour the passage of penciclovir through the epidermis into the deeper basal cells.</p

    Selective inhibition of tropomyosin-receptor-kinase A (TrkA) reduces pain and joint damage in two rat models of inflammatory arthritis

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    Background: Inflammation is an essential component of arthritis pain. Nerve growth factor (NGF) plays a key role in acute and chronic pain states especially those associated with inflammation. NGF acts through tropomyosin-receptor-kinase A (TrkA). NGF blockade has reduced arthritis pain in clinical trials. We explored the mechanisms within the joint which may contribute to the analgesic effects of NGF by selectively inhibiting TrkA in carrageenan-induced or collagen-induced joint pain behaviour. The goal of the current study was to elucidate whether inflammation is central to the efficacy for NGF blockade. Methods: Rats were injected in their left knees with 2 % carrageenan or saline. Collagen-induced arthritis (CIA) was induced by intradermal injections of a mixture of bovine type II collagen (0.2 mg) and incomplete Freund’s adjuvant (0.2 mg). Oral doses (30 mg/kg) of AR786 or vehicle control were given twice daily after arthritis induction. Ibuprofen-treated (35 mg/kg, orally, once daily) rats with CIA were used as positive analgesic controls. Pain behaviour was measured as hind-limb weight-bearing asymmetry and hind-paw withdrawal thresholds to von Frey hair stimulation (carrageenan synovitis), or withdrawal to joint compression using a Randall Selitto device (CIA). Inflammation was measured as increased knee joint diameter and by histopathological analysis. Results: Intra-articular injections of carrageenan or induction of CIA was each associated with pain behaviour and synovial inflammation. Systemic administration of the TrkA inhibitor AR786 reduced carrageenan-induced or CIA-induced pain behaviour to control values, and inhibited joint swelling and histological evidence of synovial inflammation and joint damage. Conclusions: By using two models of varying inflammation we demonstrate for the first time that selective inhibition of TrkA may reduce carrageenan-induced or CIA-induced pain behaviour in rats, in part through potentially inhibiting synovial inflammation, although direct effects on sensory nerves are also likely. Our observations suggest that inflammatory arthritis causes pain and the presence of inflammation is fundamental to the beneficial effects (reduction in pain and pathology) of NGF blockade. Further research should determine whether TrkA inhibition may ameliorate human inflammatory arthritis

    Exposure to GSM RF fields does not affect calcium homeostasis in human endothelial cells, rat pheocromocytoma cells or rat hippocampal neurons

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    In the course of modern daily life, individuals are exposed to numerous sources of electromagnetic radiation that are not present in the natural environment. The strength of the electromagnetic fields from sources such as hairdryers, computer display units and other electrical devices is modest. However, in many home and office environments, individuals can experience perpetual exposure to an "electromagnetic smog", with occasional peaks of relatively high electromagnetic field intensity. This has led to concerns that such radiation can affect health. In particular, emissions from mobile phones or mobile phone masts have been invoked as a potential source of pathological electromagnetic radiation. Previous reports have suggested that cellular calcium (Ca2+) homeostasis is affected by the types of radiofrequency fields emitted by mobile phones. In the present study, we used a high-throughput imaging platform to monitor putative changes in cellular Ca2+ during exposure of cells to 900 MHz GSM fields of differing power (specific absorption rate 0.012-2 W/Kg), thus mimicking the type of radiation emitted by current mobile phone handsets. Data from cells experiencing the 900 Mhz GSM fields were compared with data obtained from paired experiments using continuous wave fields or no field. We employed three cell types (human endothelial cells, PC-12 neuroblastoma and primary hippocampal neurons) that have previously been suggested to be sensitive to radiofrequency fields. Experiments were designed to examine putative effects of radiofrequency fields on resting Ca2+, in addition to Ca2+ signals evoked by an InsP(3)-generating agonist. Furthermore, we examined putative effects of radiofrequency field exposure on Ca2+ store emptying and store-operated Ca2+ entry following application of the Ca2+ATPase inhibitor thapsigargin. Multiple parameters (e.g., peak amplitude, integrated Ca2+ signal, recovery rates) were analysed to explore potential impact of radiofrequency field exposure on Ca2+ signals. Our data indicate that 900 MHz GSM fields do not affect either basal Ca2+ homeostasis or provoked Ca2+ signals. Even at the highest field strengths applied, which exceed typical phone exposure levels, we did not observe any changes in cellular Ca2+ signals. We conclude that under the conditions employed in our experiments, and using a highly-sensitive assay, we could not detect any consequence of RF exposure

    Identification of Gemin5 as a Novel 7-Methylguanosine Cap-Binding Protein

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    A unique attribute of RNA molecules synthesized by RNA polymerase II is the presence of a 7-methylguanosine (m(7)G) cap structure added co-transcriptionally to the 5' end. Through its association with trans-acting effector proteins, the m(7)G cap participates in multiple aspects of RNA metabolism including localization, translation and decay. However, at present relatively few eukaryotic proteins have been identified as factors capable of direct association with m(7)G.Employing an unbiased proteomic approach, we identified gemin5, a component of the survival of motor neuron (SMN) complex, as a factor capable of direct and specific interaction with the m(7)G cap. Gemin5 was readily purified by cap-affinity chromatography in contrast to other SMN complex proteins. Investigating the underlying basis for this observation, we found that purified gemin5 associates with m(7)G-linked sepharose in the absence of detectable eIF4E, and specifically crosslinks to radiolabeled cap structure after UV irradiation. Deletion analysis revealed that an intact set of WD repeat domains located in the N-terminal half of gemin5 are required for cap-binding. Moreover, using structural modeling and site-directed mutagenesis, we identified two proximal aromatic residues located within the WD repeat region that significantly impact m(7)G association.This study rigorously identifies gemin5 as a novel cap-binding protein and describes an unprecedented role for WD repeat domains in m(7)G recognition. The findings presented here will facilitate understanding of gemin5's role in the metabolism of non-coding snRNAs and perhaps other RNA pol II transcripts

    Colorectal cancer prevention for low-income, sociodemographically-diverse adults in public housing: baseline findings of a randomized controlled trial

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    Background: This paper presents the study design, intervention components, and baseline data from Open Doors to Health, a study designed to address social contextual factors in colorectal cancer (CRC) prevention for low-income, racial/ethnic minority populations. Methods: A cluster randomized design with 12 housing sites as the primary sampling units was used: 6 sites were assigned to a Peer-led plus Screening Access (PL) condition, and 6 were assigned to Screening Access only (SCR) condition. Study-related outcomes were CRC screening, physical activity (measured as mean steps/day), and multivitamin use. Results: At baseline (unweighted sample size = 1554), two-thirds self-reported that they were current with screening recommendations for CRC (corrected for medical records validation, prevalence was 52%), with half having received a colonoscopy (54%); 96% had health insurance. Mean steps per day was 5648 (se mean = 224), and on average 28% of the sample reported regular multivitamin use. Residents reported high levels of social support [mean = 4.40 (se = .03)] and moderately extensive social networks [mean = 2.66 (se = .02)]. Conclusion: Few studies have conducted community-based studies in public housing communities; these data suggest areas for improvement and future opportunities for intervention development and dissemination. Findings from the randomized trial will determine the effectiveness of the intervention on our health-related outcomes as well as inform future avenues of research
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