909 research outputs found

    Lipids induce expression of serum-responsive transmembrane kinase EhTMKB1-9 in an early branching eukaryote Entamoeba histolytica

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    Mechanisms underlying the initiation of proliferative response are known only for a few organisms, and are not understood for the medically important organisms including Entamoeba histolytica. The trans membrane kinase EhTMKB1-9 of E. histolytica is one of the early indicators of proliferation and its' expression is regulated by serum, one of the components necessary for cellular proliferation in vitro. In this study we show that bovine serum albumin (BSA) can induce EhTMKB1-9 expression in place of serum, and that both follow the same mechanism. Both serum and BSA use the same promoter element and the activation process is initiated through a PI3 kinase-mediated pathway. We further show that BSA activates EhTMKB1-9 due to the lipids associated with it and that unsaturated fatty acids are responsible for activation. These results suggest that lipid molecules are ligand(s) for initiation of a signaling system that stimulates EhTMKB1-9 expression

    Screen-detected vs symptomatic breast cancer: is improved survival due to stage migration alone?

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    This paper examines whether screen-detected breast cancer confers additional prognostic benefit to the patient, over and above that expected by any shift in stage at presentation. In all, 5604 women (aged 50–70 years) diagnosed with invasive breast cancer between 1998 and 2003 were identified by the Eastern Cancer Registration and Information Centre (ECRIC) and mammographic screening status was determined. Using proportional hazards regression, we estimated the effect of screen detection compared with symptomatic diagnosis on 5-year survival unadjusted, then adjusted for age and Nottingham Prognostic Index (NPI). A total of 72% of the survival benefit associated with screen-detected breast cancer can be accounted for by age and shift in NPI. Survival analysis by continuous NPI showed a small but systematic survival benefit for screen-detected cancers at each NPI value. These data show that although most of the screen-detected survival advantage is due to a shift in NPI, the mode of detection does impact on survival in patients with equivalent NPI scores. This residual survival benefit is small but significant, and is likely to be due to differences in tumour biology. Current prognostication tools may, therefore, overestimate the benefit of systemic treatments in screen-detected cancers and lead to overtreatment of these patients

    Metastatic skull tumors: MRI features and a new conventional classification

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    Skull metastases are malignant bone tumors which are increasing in incidence. The objectives of this study were to characterize the MR imaging features, locations, and extent of metastatic skull tumors to determine the frequency of the symptomatic disease, and to assess patient outcomes. Between September 2002 and March 2008, 175 patients undergoing routine head MR imaging were found to have metastatic skull tumors. Contrast-enhanced study with fat suppression was used in some cases when required. Classification of metastases was simplified to three yes/no questions: first, with regard to location (either in the calvarium or in the cranial base); second, with regard to distribution within the plane of the cranial bone (either “circumscribed” meaning clearly demarcated and confined to one bone, or “diffuse” and likely to spread across a suture to another bone); and third, with regard to invasion (“intraosseous” in cranial bones only, or “invasive” spreading from the skull, either out into the scalp or inward to the dura and perhaps further in). Primary sites were breast cancer (55%), lung cancer (14%), prostate cancer (6%), malignant lymphoma (5%), and others (20%). The mean time from primary diagnosis to skull metastasis diagnosis was 71 months for cases of breast cancer, 26 months for prostate cancer, 9 months for lung cancer, and 4 months for malignant lymphoma. Calvarial circumscribed intraosseous metastases were found most frequently (27%). The patients were mainly asymptomatic. However, some patients suffered from local pain or cranial nerve palsies that harmed their quality of life. Treatment, mainly for symptomatic cases, was by local or whole-skull irradiation. Metastatic skull tumors are not rare, and most are calvarial circumscribed intraosseous tumors. MR images contribute to understanding their type, location, and multiplicity, and their relationship to the brain, cranial nerves, and dural sinuses. Radiation therapy improved the QOL of patients with neurological symptoms

    The Epstein-Barr Virus G-Protein-Coupled Receptor Contributes to Immune Evasion by Targeting MHC Class I Molecules for Degradation

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    Epstein-Barr virus (EBV) is a human herpesvirus that persists as a largely subclinical infection in the vast majority of adults worldwide. Recent evidence indicates that an important component of the persistence strategy involves active interference with the MHC class I antigen processing pathway during the lytic replication cycle. We have now identified a novel role for the lytic cycle gene, BILF1, which encodes a glycoprotein with the properties of a constitutive signaling G-protein-coupled receptor (GPCR). BILF1 reduced the levels of MHC class I at the cell surface and inhibited CD8+ T cell recognition of endogenous target antigens. The underlying mechanism involves physical association of BILF1 with MHC class I molecules, an increased turnover from the cell surface, and enhanced degradation via lysosomal proteases. The BILF1 protein of the closely related CeHV15 c1-herpesvirus of the Rhesus Old World primate (80% amino acid sequence identity) downregulated surface MHC class I similarly to EBV BILF1. Amongst the human herpesviruses, the GPCR encoded by the ORF74 of the KSHV c2-herpesvirus is most closely related to EBV BILF1 (15% amino acid sequence identity) but did not affect levels of surface MHC class I. An engineered mutant of BILF1 that was unable to activate G protein signaling pathways retained the ability to downregulate MHC class I, indicating that the immune-modulating and GPCR-signaling properties are two distinct functions of BILF1. These findings extend our understanding of the normal biology of an important human pathogen. The discovery of a third EBV lytic cycle gene that cooperates to interfere with MHC class I antigen processing underscores the importance of the need for EBV to be able to evade CD8+ T cell responses during the lytic replication cycle, at a time when such a large number of potential viral targets are expressed

    A Smart Toy Intervention to Promote Emotion Regulation in Middle Childhood: Feasibility Study

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    BACKGROUND: A common challenge with existing psycho-social prevention interventions for children is the lack of effective, engaging, and scalable delivery mechanisms, especially beyond in-person therapeutic or school-based contexts. Although digital technology has the potential to address these issues, existing research on technology-enabled interventions for families remains limited. This paper focuses on emotion regulation (ER) as an example of a core protective factor that is commonly targeted by prevention interventions. // OBJECTIVE: The aim of this pilot study was to provide an initial validation of the logic model and feasibility of in situ deployment for a new technology-enabled intervention, designed to support children's in-the-moment ER efforts. The novelty of the proposed approach relies on delivering the intervention through an interactive object (a smart toy) sent home with the child, without any prior training necessary for either the child or their carer. This study examined (1) engagement and acceptability of the toy in the homes during 1-week deployments, and (2) qualitative indicators of ER effects, as reported by parents and children. In total, 10 families (altogether 11 children aged 6-10 years) were recruited from 3 predominantly underprivileged communities in the United Kingdom, as low SES populations have been shown to be particularly at risk for less developed ER competencies. Children were given the prototype, a discovery book, and a simple digital camera to keep at home for 7 to 8 days. Data were gathered through a number of channels: (1) semistructured interviews with parents and children prior to and right after the deployment, (2) photos children took during the deployment, and (3) touch interactions automatically logged by the prototype throughout the deployment. // RESULTS: Across all families, parents and children reported that the smart toy was incorporated into the children's ER practices and engaged with naturally in moments the children wanted to relax or calm down. Data suggested that the children interacted with the toy throughout the deployment, found the experience enjoyable, and all requested to keep the toy longer. Children's emotional connection to the toy appears to have driven this strong engagement. Parents reported satisfaction with and acceptability of the toy. // CONCLUSIONS: This is the first known study on the use of technology-enabled intervention delivery to support ER in situ. The strong engagement, incorporation into children's ER practices, and qualitative indications of effects are promising. Further efficacy research is needed to extend these indicative data by examining the psychological efficacy of the proposed intervention. More broadly, our findings argue for the potential of a technology-enabled shift in how future prevention interventions are designed and delivered: empowering children and parents through child-led, situated interventions, where participants learn through actionable support directly within family life, as opposed to didactic in-person workshops and a subsequent skills application

    Antipsychotic withdrawal symptoms: Phenomenology and pathophysiology

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    The authors review the literature discribing non-dyskinetic antipsychotic withdrawal phenomena. Withdrawal of these agents can cause nausea, emesis, anorexia, diarrhea, rhinorrhea, diaphoresis, myalgia, paresthesia, anxiety, agitation, restlessness, and insomnia. Psychotic relapse is often presaged by increased anxiety, agitation, restlessness and insomnia, but the temporal relationship of these prodromal symptoms to reduction in the dosage or discontinuation of neuroleptics distinguishes them from the effects of abrupt withdrawal.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65190/1/j.1600-0447.1988.tb05116.x.pd

    Rasch model analysis of the Depression, Anxiety and Stress Scales (DASS)

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    <p>Abstract</p> <p>Background</p> <p>There is a growing awareness of the need for easily administered, psychometrically sound screening tools to identify individuals with elevated levels of psychological distress. Although support has been found for the psychometric properties of the Depression, Anxiety and Stress Scales (DASS) using classical test theory approaches it has not been subjected to Rasch analysis. The aim of this study was to use Rasch analysis to assess the psychometric properties of the DASS-21 scales, using two different administration modes.</p> <p>Methods</p> <p>The DASS-21 was administered to 420 participants with half the sample responding to a web-based version and the other half completing a traditional pencil-and-paper version. Conformity of DASS-21 scales to a Rasch partial credit model was assessed using the RUMM2020 software.</p> <p>Results</p> <p>To achieve adequate model fit it was necessary to remove one item from each of the DASS-21 subscales. The reduced scales showed adequate internal consistency reliability, unidimensionality and freedom from differential item functioning for sex, age and mode of administration. Analysis of all DASS-21 items combined did not support its use as a measure of general psychological distress. A scale combining the anxiety and stress items showed satisfactory fit to the Rasch model after removal of three items.</p> <p>Conclusion</p> <p>The results provide support for the measurement properties, internal consistency reliability, and unidimensionality of three slightly modified DASS-21 scales, across two different administration methods. The further use of Rasch analysis on the DASS-21 in larger and broader samples is recommended to confirm the findings of the current study.</p

    Permutation criteria to evaluate multiple clinical endpoints in a proof-of-concept study: lessons from Pre-RELAX-AHF

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    Clinically relevant endpoints cannot be routinely targeted with reasonable power in a small study. Hence, proof-of-concept studies are often powered to a primary surrogate endpoint. However, in acute heart failure (AHF) effects on surrogates have not translated into clinical benefit in confirmatory studies. Although observing an effect on one of many endpoints due to chance is likely, observing concurrent positive trends across several outcomes by chance is usually unlikely. Pre-RELAX-AHF, which compared 4 relaxin doses with placebo in AHF, has shown favourable trends versus placebo (one-sided P <0.10) on six of nine clinical endpoints in the 30 mu g/kg/day group. To illustrate evaluation of multiple, correlated clinical endpoints for evidence of efficacy and for dose selection, a permutation method was applied retrospectively. By randomly re-assigning the treatment group to the actual data for each of the 229 subjects, 20,000 permutation samples were constructed. The permutation P value for at least six favourable trends among nine endpoints in any dose groups was 0.0073 (99.9% CI 0.0053-0.0093). This is higher than would be expected if the endpoints were uncorrelated (0.00026), but much lower than the probability of observing one of nine comparisons significant at the traditional two-sided P <0.05 (0.74). Thus, the result was unlikely due to correlated endpoints or to chance. Examining consistency of effect across multiple clinical endpoints in a proof-of-concept study may identify efficacious therapies and enable dose selection for confirmatory trials. The merit of the approach described requires confirmation through prospective application in designing future studies

    Medical and Welfare Officers beliefs about post-deployment screening for mental health disorders in the UK Armed Forces: a qualitative study

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    BACKGROUND: This study aimed to examine currently serving United Kingdom (UK) military Medical and Welfare Officers views on the potential introduction of post-deployment screening for mental ill health. METHODS: Semi-structured interviews were conducted with 21 Medical and Welfare Officers. Interview transcripts were analysed using data-driven thematic analysis. RESULTS: Four themes were identified: positive views of screening; reliability of responses; impact on workload; and suggestions for implementation. Interviewees viewed the introduction of screening post-deployment as likely to increase awareness of mental health problems whilst also reporting that service personnel were likely to conceal their true mental health status by providing misleading responses to any screening tool. Concern over reliability of responses may provide one explanation for the reluctance of service personnel to seek help for problems, as they could feel they will not be taken seriously. Welfare Officers felt they would not have the knowledge or experience to respond to help-seeking. Although participants were concerned about potential impact on their personal workload, they indicated a desire to positively engage with the screening programme if research showed it was an effective tool to improve mental health care. CONCLUSIONS: Welfare and healthcare providers are well disposed towards a screening programme for mental health but highlight a few concerns in its implementation. In particular Welfare Officers appear to require more training in how to respond to mental ill health. Concerns about available funding and resources to respond to increased workload will need to be addressed should post-deployment screening for mental health be introduced in the UK military
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