164 research outputs found

    Complete Determination of the Pin1 Catalytic Domain Thermodynamic Cycle by NMR Lineshape Analysis

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    The phosphorylation-specific peptidyl-prolyl isomerase Pin1 catalyzes the isomerization of the peptide bond preceding a proline residue between cis and trans isomers. To best understand the mechanisms of Pin1 regulation, rigorous enzymatic assays of isomerization are required. However, most measures of isomerase activity require significant constraints on substrate sequence and only yield rate constants for the cis isomer, kciscatand apparent Michaelis constants, KAppM . By contrast, NMR lineshape analysis is a powerful tool for determining microscopic rates and populations of each state in a complex binding scheme. The isolated catalytic domain of Pin1 was employed as a first step towards elucidating the reaction scheme of the full-length enzyme. A 24-residue phosphopeptide derived from the amyloid precurser protein intracellular domain (AICD) phosphorylated at Thr668 served as a biologically-relevant Pin1 substrate. Specific 13C labeling at the Pin1-targeted proline residue provided multiple reporters sensitive to individual isomer binding and on-enzyme catalysis. We have performed titration experiments and employed lineshape analysis of phosphopeptide 13Cā€“1H constant time HSQC spectra to determine kciscat , ktranscat , KcisD , and KtransD for the catalytic domain of Pin1 acting on this AICD substrate. The on-enzyme equilibrium value of [EĀ·trans]/[EĀ·cis] = 3.9 suggests that the catalytic domain of Pin1 is optimized to operate on this substrate near equilibrium in the cellular context. This highlights the power of lineshape analysis for determining the microscopic parameters of enzyme catalysis, and demonstrates the feasibility of future studies of Pin1-PPIase mutants to gain insights on the catalytic mechanism of this important enzyme

    A Noncanonical Binding Site in the EVH1 Domain of Vasodilator-Stimulated Phosphoprotein Regulates Its Interactions with the Proline Rich Region of Zyxin

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    Vasodilator-stimulated phosphoprotein (VASP) is a processive actin polymerase with roles in the control of cell shape and cell migration. Through interaction with the cytoskeletal adaptor protein Zyxin, VASP can localize to damaged stress fibers where it serves to repair and reinforce these structures. VASP localization is mediated by its N-terminal Ena/VASP homology (EVH1) domain, which binds to the (W/F)Px phi P motif (most commonly occurring as FPPPP) found in cytoskeletal proteins such as vinculin, lamellipodin, and Zyxin. Sequentially close clusters of four or five of these motifs frequently occur, as in the proline rich region of Zyxin with four such motifs. This suggests that tetrameric VASP might bind very tightly to Zyxin through avidity, with all four EVH1 domains binding to a single Zyxin molecule. Here, quantitative nuclear magnetic resonance titration analysis reveals a dominant bivalent 1:1 (Zyxin:EVH1)interaction between the Zyxin proline rich region and the VASP EVH1 domain that utilizes the EVH1 canonical binding site and a novel secondary binding site on the opposite face of the EVH1 domain. We further show that binding to the secondary binding site is specifically inhibited by mutation of VASP EVH1 domain residue Y39 to E, which mimics Abl-induced phosphorylation of Y39. On the basis of these findings, we propose a model in which phosphorylation of Y39 acts as a stoichiometry switch that governs binding partner selection by the constitutive VASP tetramer. These results have broader implications for other multivalent VASP EVH1 domain binding partners and for furthering our understanding of the role of Y39 phosphorylation in regulating VASP localization and cellular function

    The Burden of Uterine Fibroids for African-American Women: Results of a National Survey

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    Uterine fibroids have a disproportionate impact on African-American women. There are, however, no data to compare racial differences in symptoms, quality of life, effect on employment, and information-seeking behavior for this disease

    The impact of uterine leiomyomas: a national survey of affected women

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    To characterize the impact of uterine leiomyomas (fibroids) in a racially diverse sample of women in the United States

    The experience of admission to psychiatric hospital among Chinese adult patients in Hong Kong

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    <p>Abstract</p> <p>Background</p> <p>The paper reports on a study to evaluate the psychometric properties and cultural appropriateness of the Chinese translation of the Admission Experience Survey (AES).</p> <p>Methods</p> <p>The AES was translated into Chinese and back-translated. Content validity was established by focus groups and expert panel review. The Chinese version of the Admission Experience Survey (C-AES) was administered to 135 consecutively recruited adult psychiatric patients in the Castle Peak Hospital (Hong Kong SAR, China) within 48 hours of admission. Construct validity was assessed by comparing the scores from patients admitted voluntarily versus patients committed involuntarily, and those received physical or chemical restraint versus those who did not. The relationship between admission experience and psychopathology was examined by correlating C-AES scores with the Brief Psychiatric Rating Scale (BPRS) scores.</p> <p>Results</p> <p>Spearman's item-to-total correlations of the C-AES ranged from 0.50 to 0.74. Three factors from the C-AES were extracted using factor analysis. Item 12 was omitted because of poor internal consistency and factor loading. The factor structure of the Process Exclusion Scale (C-PES) corresponded to the English version, while some discrepancies were noted in the Perceived Coercion Scale (C-PCS) and the Negative Pressure Scale (C-NPS). All subscales had good internal consistencies. Scores were significantly higher for patients either committed involuntarily or subjected to chemical or physical restrain, independent on severity of psychotic symptoms.</p> <p>Conclusion</p> <p>The Chinese AES is a psychometrically sound instrument assessing the three different aspects of the experience of admission, namely "negative pressure, "process exclusion" and "perceived coercion". The potential of C-AES in exploring subjective experience of psychiatric admission and effects on treatment adherence should be further explored.</p

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25Ā·4% (95% CI 19Ā·1-31Ā·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7Ā·8%, 4Ā·8-10Ā·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27Ā·2%, 17Ā·6-36Ā·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33Ā·0%, 18Ā·3-47Ā·6; I2 =98%) than in other migrant groups (6Ā·6%, 1Ā·8-11Ā·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33Ā·1%, 11Ā·1-55Ā·1; I2 =96%) than in migrants in hospitals (24Ā·3%, 16Ā·1-32Ā·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Family day care educators : an exploration of their understanding and experiences promoting children\u27s social and emotional wellbeing

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    This study aimed to explore family day care (FDC) educators&rsquo; knowledge of child social and emotional wellbeing and mental health problems, the strategies used to promote children&rsquo;s wellbeing, and barriers and opportunities for promoting children&rsquo;s social and emotional wellbeing. Thirteen FDC educators participated in individual semi-structured interviews. FDC educators were more comfortable defining children&rsquo;s social and emotional wellbeing than they were in identifying causes and early signs of mental health problems. Strategies used to promote children&rsquo;s mental health were largely informal and dependent on educator skills and capacities rather than a systematic scheme-wide approach. Common barriers to mental health promotion were limited financial resources, a need for more training and hesitance raising child mental health issues with parents. There is a need to build FDC educators&rsquo; knowledge of child social and emotional wellbeing and for tailored mental health promotion strategies in FDC.<br /

    Prolactin-induced mouse mammary carcinomas model estrogen resistant luminal breast cancer.

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    INTRODUCTION: Tumors that express estrogen receptor alpha (ERĪ±+) comprise 75% of breast cancers in women. While treatments directed against this receptor have successfully lowered mortality rates, many primary tumors initially or later exhibit resistance. The paucity of murine models of this luminal tumor subtype has hindered studies of factors that promote their pathogenesis and modulate responsiveness to estrogen-directed therapeutics. Since epidemiologic studies closely link prolactin and the development of ERĪ±+ tumors in women, we examined characteristics of the aggressive ERĪ±+ and ERĪ±- carcinomas which develop in response to mammary prolactin in a murine transgenic model (neu-related lipocalin- prolactin (NRL-PRL)). To evaluate their relationship to clinical tumors, we determined phenotypic relationships among these carcinomas, other murine models of breast cancer, and features of luminal tumors in women. METHODS: We examined a panel of prolactin-induced tumors for characteristics relevant to clinical tumors: histotype, ERĪ±/progesterone receptor (PR) expression and estrogen responsiveness, Activating Protein 1 (AP-1) components, and phosphorylation of signal transducer and activator of transcription 5 (Stat5), extracellular signal regulated kinase (ERK) 1/2 and AKT. We compared levels of transcripts in the ERĪ±-associated luminal signature that defines this subtype of tumors in women and transcripts enriched in various mammary epithelial lineages to other well-studied genetically modified murine models of breast cancer. Finally, we used microarray analyses to compare prolactin-induced ERĪ±+ and ERĪ±- tumors, and examined responsiveness to estrogen and the anti-estrogen, Faslodex, in vivo. RESULTS: Prolactin-induced carcinomas were markedly diverse with respect to histotype, ERĪ±/PR expression, and activated signaling cascades. They constituted a heterogeneous, but distinct group of murine mammary tumors, with molecular features of the luminal subtype of human breast cancer. In contrast to morphologically normal and hyperplastic structures in NRL-PRL females, carcinomas were insensitive to ERĪ±-mediated signals. These tumors were distinct from mouse mammary tumor virus (MMTV)-neu tumors, and contained elevated transcripts for factors associated with luminal/alveolar expansion and differentiation, suggesting that they arose from physiologic targets of prolactin. These features were shared by ERĪ±+ and ERĪ±- tumors, suggesting a common origin, although the former exhibited transcript profiles reflecting greater differentiation. CONCLUSIONS: Our studies demonstrate that prolactin can promote diverse carcinomas in mice, many of which resemble luminal breast cancers, providing a novel experimental model to examine the pathogenesis, progression and treatment responsiveness of this tumor subtype
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