1,011 research outputs found

    Structure and Dynamics of Cholesterol-Containing Polyunsaturated Lipid Membranes Studied by Neutron Diffraction and NMR

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    A direct and quantitative analysis of the internal structure and dynamics of a polyunsaturated lipid bilayer composed of 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (18:0-22:6n3-PC) containing 29 mol% cholesterol was carried out by neutron diffraction, 2H-NMR and 13C-MAS NMR. Scattering length distribution functions of cholesterol segments as well as of the sn-1 and sn-2 hydrocarbon chains of 18:0-22:6n3-PC were obtained by conducting experiments with specifically deuterated cholesterol and lipids. Cholesterol orients parallel to the phospholipids, with the A-ring near the lipid glycerol and the terminal methyl groups 3 Å away from the bilayer center. Previously, we reported that the density of polyunsaturated docosahexaenoic acid (DHA, 22:6n3) chains was higher near the lipid–water interface. Addition of cholesterol partially redistributes DHA density from near the lipid–water interface to the center of the hydrocarbon region. Cholesterol raises chain-order parameters of both stearic acid and DHA chains. The fractional order increase for stearic acid methylene carbons C8–C18 is larger, reflecting the redistribution of DHA chain density toward the bilayer center. The correlation times of DHA chain isomerization are short and mostly unperturbed by the presence of cholesterol. The uneven distribution of saturated and polyunsaturated chain densities and the cholesterol-induced balancing of chain distributions may have important implications for the function and integrity of membrane receptors, such as rhodopsin

    Negative Regulators of Insulin Signaling Revealed in a Genome-Wide Functional Screen

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    Type 2 diabetes develops due to a combination of insulin resistance and β-cell failure and current therapeutics aim at both of these underlying causes. Several negative regulators of insulin signaling are known and are the subject of drug discovery efforts. We sought to identify novel contributors to insulin resistance and hence potentially novel targets for therapeutic intervention.An arrayed cDNA library encoding 18,441 human transcripts was screened for inhibitors of insulin signaling and revealed known inhibitors and numerous potential novel regulators. The novel hits included proteins of various functional classes such as kinases, phosphatases, transcription factors, and GTPase associated proteins. A series of secondary assays confirmed the relevance of the primary screen hits to insulin signaling and provided further insight into their modes of action.Among the novel hits was PALD (KIAA1274, paladin), a previously uncharacterized protein that when overexpressed led to inhibition of insulin's ability to down regulate a FOXO1A-driven reporter gene, reduced upstream insulin-stimulated AKT phosphorylation, and decreased insulin receptor (IR) abundance. Conversely, knockdown of PALD gene expression resulted in increased IR abundance, enhanced insulin-stimulated AKT phosphorylation, and an improvement in insulin's ability to suppress FOXO1A-driven reporter gene activity. The present data demonstrate that the application of arrayed genome-wide screening technologies to insulin signaling is fruitful and is likely to reveal novel drug targets for insulin resistance and the metabolic syndrome

    Analisis Kekuatan Massa Batugamping Dengan Menggunakan Kaidah Hoek-Brown Failure Criterion-Roclab Di Daerah Gunung Sudo Kabupaten Gunung Kidul YOGYAKARTA

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    The research area is a limestone quarry region prospect, located in Gunung Sudo, Gunung Kidul Regency, Special Region of Yogyakarta Province. Safety factor of bench in limestone quarry is extremely determined by rock mass quality. The aim of this research is analyzing of rock mass strength of limestone in the quarry prospect using the Hoek-Brown failure criterion. The research used quantitative method. To obtain rock mass strength analysis of limestone needs some parameters. The main parameters are uniaxial compressive strength of intact rock, GSI, lithology, disturbance factor, unit weight and application for slope (height).To solve this analysis is assisted by Roclab software. The Roclab is a software program for determining rock mass strength parameters based on the generalized Hoek-Brown failure criterion. Final result of the research will be used for safely mine design of the limestone quarry

    Surprisingly High Specificity of the PPD Skin Test for M. tuberculosis Infection from Recent Exposure in The Gambia

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    BACKGROUND: Options for intervention against Mycobacterium tuberculosis infection are limited by the diagnostic tools available. The Purified Protein Derivative (PPD) skin test is thought to be non-specific, especially in tropical settings. We compared the PPD skin test with an ELISPOT test in The Gambia. METHODOLOGY/PRINCIPAL FINDINGS: Household contacts over six months of age of sputum smear positive TB cases and community controls were recruited. They underwent a PPD skin test and an ELISPOT test for the T cell response to PPD and ESAT-6/CFP10 antigens. Responsiveness to M. tuberculosis exposure was analysed according to sleeping proximity to an index case using logistic regression. 615 household contacts and 105 community controls were recruited. All three tests assessed increased significantly in positivity with increasing M. tuberculosis exposure, the PPD skin test most dramatically (OR 15.7; 95% CI 6.6–35.3). While the PPD skin test positivity continued to trend downwards in the community with increasing distance from a known case (61.9% to 14.3%), the PPD and ESAT-6/CFP-10 ELISPOT positivity did not. The PPD skin test was more in agreement with ESAT-6/CFP-10 ELISPOT (75%, p = 0.01) than the PPD ELISPOT (53%, p<0.0001). With increasing M. tuberculosis exposure, the proportion of ESAT-6/CFP-10 positive contacts who were PPD skin test positive increased (p<0.0001), and the proportion of ESAT-6/CFP-10 negative contacts that were PPD skin test negative decreased (p<0.0001); the converse did not occur. CONCLUSIONS/SIGNIFICANCE: The PPD skin test has surprisingly high specificity for M. tuberculosis infection from recent exposure in The Gambia. In this setting, anti-tuberculous prophylaxis in PPD skin test positive individuals should be revisited

    Spatial chemical distance based on atomic property fields

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    Similarity of compound chemical structures often leads to close pharmacological profiles, including binding to the same protein targets. The opposite, however, is not always true, as distinct chemical scaffolds can exhibit similar pharmacology as well. Therefore, relying on chemical similarity to known binders in search for novel chemicals targeting the same protein artificially narrows down the results and makes lead hopping impossible. In this study we attempt to design a compound similarity/distance measure that better captures structural aspects of their pharmacology and molecular interactions. The measure is based on our recently published method for compound spatial alignment with atomic property fields as a generalized 3D pharmacophoric potential. We optimized contributions of different atomic properties for better discrimination of compound pairs with the same pharmacology from those with different pharmacology using Partial Least Squares regression. Our proposed similarity measure was then tested for its ability to discriminate pharmacologically similar pairs from decoys on a large diverse dataset of 115 protein–ligand complexes. Compared to 2D Tanimoto and Shape Tanimoto approaches, our new approach led to improvement in the area under the receiver operating characteristic curve values in 66 and 58% of domains respectively. The improvement was particularly high for the previously problematic cases (weak performance of the 2D Tanimoto and Shape Tanimoto measures) with original AUC values below 0.8. In fact for these cases we obtained improvement in 86% of domains compare to 2D Tanimoto measure and 85% compare to Shape Tanimoto measure. The proposed spatial chemical distance measure can be used in virtual ligand screening

    Prevalence of Borderline Personality Disorder in University Samples: Systematic Review, Meta-Analysis and Meta-Regression.

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    OBJECTIVE: To determine pooled prevalence of clinically significant traits or features of Borderline Personality Disorder among college students, and explore the influence of methodological factors on reported prevalence figures, and temporal trends. DATA SOURCES: Electronic databases (1994-2014: AMED; Biological Abstracts; Embase; MEDLINE; PsycARTICLES; CINAHL Plus; Current Contents Connect; EBM Reviews; Google Scholar; Ovid Medline; Proquest central; PsychINFO; PubMed; Scopus; Taylor & Francis; Web of Science (1998-2014), and hand searches. STUDY SELECTION: Forty-three college-based studies reporting estimates of clinically significant BPD symptoms were identified (5.7% of original search). DATA EXTRACTION: One author (RM) extracted clinically relevant BPD prevalence estimates, year of publication, demographic variables, and method from each publication or through correspondence with the authors. RESULTS: The prevalence of BPD in college samples ranged from 0.5% to 32.1%, with lifetime prevalence of 9.7% (95% CI, 7.7-12.0; p &lt; .005). Methodological factors contributing considerable between-study heterogeneity in univariate meta-analyses were participant anonymity, incentive type, research focus and participant type. Study and sample characteristics related to between study heterogeneity were sample size, and self-identifying as Asian or "other" race. The prevalence of BPD varied over time: 7.8% (95% CI 4.2-13.9) between 1994 and 2000; 6.5% (95% CI 4.0-10.5) during 2001 to 2007; and 11.6% (95% CI 8.8-15.1) from 2008 to 2014, yet was not a source of heterogeneity (p = .09). CONCLUSIONS: BPD prevalence estimates are influenced by the methodological or study sample factors measured. There is a need for consistency in measurement across studies to increase reliability in establishing the scope and characteristics of those with BPD engaged in tertiary study

    Trauma-related emotions and radical acceptance in dialectical behavior therapy for posttraumatic stress disorder after childhood sexual abuse

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    Background: Posttraumatic Stress Disorder (PTSD) related to childhood sexual abuse (CSA) is often associated with a wide range of trauma-related aversive emotions such as fear, disgust, sadness, shame, guilt, and anger. Intense experience of aversive emotions in particular has been linked to higher psychopathology in trauma survivors. Most established psychosocial treatments aim to reduce avoidance of trauma-related memories and associated emotions. Interventions based on Dialectical Behavior Therapy (DBT) also foster radical acceptance of the traumatic event. Methods: This study compares individual ratings of trauma-related emotions and radical acceptance between the start and the end of DBT for PTSD (DBT-PTSD) related to CSA. We expected a decrease in trauma-related emotions and an increase in acceptance. In addition, we tested whether therapy response according to the Clinician Administered PTSD-Scale (CAPS) for the DSM-IV was associated with changes in trauma-related emotions and acceptance. The data was collected within a randomized controlled trial testing the efficacy of DBT-PTSD, and a subsample of 23 women was included in this secondary data analysis. Results: In a multilevel model, shame, guilt, disgust, distress, and fear decreased significantly from the start to the end of the therapy whereas radical acceptance increased. Therapy response measured with the CAPS was associated with change in trauma-related emotions. Conclusions: Trauma-related emotions and radical acceptance showed significant changes from the start to the end of DBT-PTSD. Future studies with larger sample sizes and control group designs are needed to test whether these changes are due to the treatment. Trial registration: ClinicalTrials.gov, number NCT0048100

    Cholesterol Induces Specific Spatial and Orientational Order in Cholesterol/Phospholipid Membranes

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    In lipid bilayers, cholesterol facilitates the formation of the liquid-ordered phase and enables the formation of laterally ordered structures such as lipid rafts. While these domains have an important role in a variety of cellular processes, the precise atomic-level mechanisms responsible for cholesterol's specific ordering and packing capability have remained unresolved

    Cholesterol Induces Specific Spatial and Orientational Order in Cholesterol/Phospholipid Membranes

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    In lipid bilayers, cholesterol facilitates the formation of the liquid-ordered phase and enables the formation of laterally ordered structures such as lipid rafts. While these domains have an important role in a variety of cellular processes, the precise atomic-level mechanisms responsible for cholesterol's specific ordering and packing capability have remained unresolved
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