187 research outputs found

    A new automated technique for the reconstitution of hydrophobic proteins into planar bilayer membranes. Studies of human recombinant uncoupling protein 1

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    AbstractElectrophysiological characterisation of the vast number of annotated channel and transport proteins in the postgenomic era would be greatly facilitated by the introduction of rapid and robust methods for the functional incorporation of membrane proteins into defined lipid bilayers. Here, we describe an automated technique for reconstitution of membrane proteins into lipid bilayer membranes, which substantially reduces both the reconstitution time and the amount of protein required for the membrane formation. The method allows the investigation of single protein channels as well as insertion of multiple copies (∌107) into a single bilayer. Despite a comparatively large membrane area (up to 300 Όm diameter), the high stability of the membrane permits the application of transmembrane voltages up to 300 mV. This feature is especially important for studies of inner membrane mitochondrial proteins, since they act at potentials up to ∌200 mV under physiological conditions. It is a combination of these advantages that enables the detailed investigation of the minuscule single protein conductances typical for proton transporters. We have applied the new technique for the reconstitution and electrophysiological characterisation of human recombinant uncoupling protein 1, hUCP1, that has been overexpressed in E. coli and purified from inclusion bodies. We demonstrate that hUCP1 activity in the presence of fatty acids is comparable to the activity of UCP1 isolated from brown adipose tissue

    Maternal Transmission of Resistance to Development of Allergic Airway Disease

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    Parental phenotype is known to influence the inheritance of atopic diseases, such as allergic asthma, with a maternal history being a more significant risk factor for progeny than paternal history. We hypothesized that recall Th1- or Th2-type immune responses during pregnancy would result in transfer of maternal factors that would differentially impact development of immune responsiveness in offspring. Following weaning, susceptibility and severity of allergic airway disease (a murine model of human asthma) was evaluated in progeny, disease being elicited by immunization with OVA-Al(OH)3 and challenge with aerosolized OVA. We found that progeny of mothers with Th1-biased immunity to OVA subjected to recall aerosol challenge during pregnancy had reduced levels of Ag-specific IgE and airway eosinophilia compared with progeny of mothers with Th2-biased immunity to OVA or naive mothers. Interestingly, progeny of mothers with Th1-type immunity to a heterologous albumin, BSA, were not protected from developing OVA-induced allergic airway disease. These findings demonstrated that maternal transfer of protection from development of allergic airway disease to offspring in this model of maternal Th1-type immunity was Ag specific

    Russian Arctic Vegetation Archive—A new database of plant community composition and environmental conditions

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    Motivation: The goal of the Russian Arctic Vegetation Archive (AVA-RU) is to unite and harmonize data of plot-based plant species and their abundance, vegetation structure and environmental variables from the Russian Arctic. This database can be used to assess the status of the Russian Arctic vegetation and as a baseline to document biodiversity changes in the future. The archive can be used for scientific studies as well as to inform nature protection and restoration efforts. Main types of variables contained: The archive contains 2873 open-access geobotanical plots. The data include the full species. Most plots include information on the horizontal (cover per species and morphological group) and vertical (average height per morphological group) structure of vegetation, site and soil descriptions and data quality estimations. In addition to the open-access data, the AVA-RU website contains 1912 restricted-access plots. Spatial location and grain: The plots of 1–100 m2 size were sampled in Arctic Russia and Scandinavia. Plots in Russia covered areas from the West to the East, including the European Russian Arctic (Kola Peninsula, Nenets Autonomous district), Western Siberia (Northern Urals, Yamal, Taza and Gydan peninsulas), Central Siberia (Taymyr peninsula, Bolshevik island), Eastern Siberia (Indigirka basin) and the Far East (Wrangel island). About 72% of the samples are georeferenced. Time period and grain: The data were collected once at each location between 1927 and 2022. Major taxa and level of measurement: Plots include observations of >1770 vascular plant and cryptogam species and subspecies. Software format: CSV files (1 file with species list and abundance, 1 file with environmental variables and vegetation structure) are stored at the AVA-RU website (https://avarus.space/), and are continuously updated with new datasets. The open-access data are available on Dryad and all the datasets have a backup on the server of the University of Zurich. The data processing R script is available on Dryad

    The ASCEND study: protocol for a feasibility study to evaluate an early social communication intervention for young children with Down syndrome

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    Background Down syndrome is the most common cause of learning disability, affecting approximately 1 in every 700 babies. Children with Down syndrome have particular difficulties with speech and language. This makes it challenging for them to participate fully in life, access healthcare services and educational opportunities. Improving the language skills of young children with Down syndrome is vital for their future social and emotional well-being and behaviour, and consequently contribution to society. As Down syndrome is detected before or at birth, we can provide support from early on. There are currently no standard interventions for improving the language skills of children with Down syndrome under the age of 36 months. Evidence suggests that early parent-based interventions may be effective in improving language outcomes. In partnership with parents and speech and language therapists, we have co-developed an intervention focusing on early social communication skills and our preliminary work shows that it can lead to better language in children with Down syndrome. Our aim is to carry out a feasibility study which will inform a future pilot/full trial to test whether the intervention is effective in improving language skills before children with Down syndrome start school. Methods This is a two-arm feasibility randomised controlled trial (RCT), with 1:1 randomisation stratified by trial site comparing the intervention (plus standard NHS speech and language therapy) with no intervention (standard NHS speech and language therapy only). We aim to recruit between 25 and 30 children with Down syndrome aged between 11 and 36 months. Sites are defined by the geographical boundaries of three National Health Service (NHS) Trusts. Recruitment is from NHS Speech and Language Therapist caseloads within the 3 Trusts, and self-referral. In the intervention arm, parents/guardians will receive brief training on the parent-based intervention and a manual to follow with their child for 10 weeks. The children’s language and early communication skills and family health outcomes will be assessed by a blinded assessor at baseline, post-intervention and 6 month follow-up. Questionnaire and semi-structured interviews will explore the acceptability of the intervention to parents and SLTs. Discussion The feasibility study’s outcomes will determine whether it would be viable to progress to a full-trial and whether adjustments need to made to the procedures, data collection methods, intervention delivery and the intensity of support needed. We want to assess whether our early intervention can be delivered and rolled out through NHS Speech and Language Therapy (SLT) Services. We anticipate that NHS SLT Services will need to make ongoing changes due to the COVID-19 pandemic, so it is likely that we will need to make adjustments for the definitive trial. We will also calculate descriptive statistics of the language outcome measure which we will use for any future sample size calculation

    PROTEUS Study: A Prospective Randomised Controlled Trial Evaluating the Use of Artificial Intelligence in Stress Echocardiography.

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    BACKGROUND Stress echocardiography (SE) is one of the most commonly used diagnostic imaging tests for coronary artery disease (CAD) but requires clinicians to visually assess scans to identify patients who may benefit from invasive investigation and treatment. EchoGo Pro provides an automated interpretation of SE based on artificial intelligence (AI) image analysis. In reader studies, use of EchoGo Pro when making clinical decisions improves diagnostic accuracy and confidence. Prospective evaluation in real world practice is now important to understand the impact of EchoGo Pro on the patient pathway and outcome. METHODS/DESIGN PROTEUS is a randomised, multicentre, two-armed, non-inferiority study aiming to recruit 2,500 participants from National Health Service (NHS) hospitals in the UK referred to SE clinics for investigation of suspected CAD. All participants will undergo a stress echocardiogram protocol as per local hospital policy. Participants will be randomised 1:1 to a control group, representing current practice, or an intervention group, in which clinicians will receive an AI image analysis report (EchoGo Pro, Ultromics Ltd, Oxford, UK) to use during image interpretation, indicating the likelihood of severe CAD. The primary outcome will be appropriateness of clinician decision to refer for coronary angiography. Secondary outcomes will assess other health impacts including appropriate use of other clinical management approaches, impact on variability in decision making, patient and clinician qualitative experience and a health economic analysis. DISCUSSION This will be the first study to assess the impact of introducing an AI medical diagnostic aid into the standard care pathway of patients with suspected CAD being investigated with SE

    Evasion of anti-growth signaling: a key step in tumorigenesis and potential target for treatment and prophylaxis by natural compounds

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    The evasion of anti-growth signaling is an important characteristic of cancer cells. In order to continue to proliferate, cancer cells must somehow uncouple themselves from the many signals that exist to slow down cell growth. Here, we define the anti-growth signaling process, and review several important pathways involved in growth signaling: p53, phosphatase and tensin homolog (PTEN), retinoblastoma protein (Rb), Hippo, growth differentiation factor 15 (GDF15), AT-rich interactive domain 1A (ARID1A), Notch, insulin-like growth factor (IGF), and KrĂŒppel-like factor 5 (KLF5) pathways. Aberrations in these processes in cancer cells involve mutations and thus the suppression of genes that prevent growth, as well as mutation and activation of genes involved in driving cell growth. Using these pathways as examples, we prioritize molecular targets that might be leveraged to promote anti-growth signaling in cancer cells. Interestingly, naturally-occurring phytochemicals found in human diets (either singly or as mixtures) may promote anti-growth signaling, and do so without the potentially adverse effects associated with synthetic chemicals. We review examples of naturally-occurring phytochemicals that may be applied to prevent cancer by antagonizing growth signaling, and propose one phytochemical for each pathway. These are: epigallocatechin-3-gallate (EGCG) for the Rb pathway, luteolin for p53, curcumin for PTEN, porphyrins for Hippo, genistein for GDF15, resveratrol for ARID1A, withaferin A for Notch and diguelin for the IGF1-receptor pathway. The coordination of anti-growth signaling and natural compound studies will provide insight into the future application of these compounds in the clinical setting

    Sustained proliferation in cancer: mechanisms and novel therapeutic targets

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    Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression

    Large-scale remote fear conditioning: demonstration of associations with anxiety using the FLARe smartphone app

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    Objectives We aimed to examine differences in fear conditioning between anxious and nonanxious participants in a single large sample. Materials and methods We employed a remote fear conditioning task (FLARe) to collect data from participants from the Twins Early Development Study (n = 1,146; 41% anxious vs. 59% nonanxious). Differences between groups were estimated for their expectancy of an aversive outcome towards a reinforced conditional stimulus (CS+) and an unreinforced conditional stimulus (CS−) during acquisition and extinction phases. Results During acquisition, the anxious group (vs. nonanxious group) showed greater expectancy towards the CS−. During extinction, the anxious group (vs. nonanxious group) showed greater expectancy to both CSs. These comparisons yielded effect size estimates (d = 0.26–0.34) similar to those identified in previous meta‐analyses. Conclusion The current study demonstrates that remote fear conditioning can be used to detect differences between groups of anxious and nonanxious individuals, which appear to be consistent with previous meta‐analyses including in‐person studies

    Las ciencias sociales en el noreste de MĂ©xico.

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    Texto colectivo que incluye seis ensayos donde se reflexiona sobre el estado que guardan las ciencias sociales en el noreste de MĂ©xico: antropologĂ­a, comunicaciĂłn, economĂ­a, geografĂ­a, historia y sociologĂ­a.Redactado por miembros del Grupo Gente (Grupo de Estudios sobre el Noreste de MĂ©xico y Texas) bajo la coordinaciĂłn de CĂ©sar Morado y Lucila Hinojosa

    Concern with COVID-19 pandemic threat and attitudes towards immigrants: The mediating effect of the desire for tightness

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    Tightening social norms is thought to be adaptive for dealing with collective threat yet it may have negative consequences for increasing prejudice. The present research investigated the role of desire for cultural tightness, triggered by the COVID-19 pandemic, in increasing negative attitudes towards immigrants. We used participant-level data from 41 countries (N = 55,015) collected as part of the PsyCorona project, a crossnational longitudinal study on responses to COVID-19. Our predictions were tested through multilevel and SEM models, treating participants as nested within countries. Results showed that people’s concern with COVID19 threat was related to greater desire for tightness which, in turn, was linked to more negative attitudes towards immigrants. These findings were followed up with a longitudinal model (N = 2,349) which also showed that people’s heightened concern with COVID-19 in an earlier stage of the pandemic was associated with an increase in their desire for tightness and negative attitudes towards immigrants later in time. Our findings offer insight into the trade-offs that tightening social norms under collective threat has for human groups
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