349 research outputs found

    Measurement of endothelial function and its clinical utility for cardiovascular risk

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    Over the past two decades, the central role of the endothelium in the initiation, progression, and clinical sequelae of atherosclerosis has been increasingly recognized. Assessment of the pathobiology of the endothelium and its ability to act as a potential therapeutic target remains an area of active research interest. Whilst endothelial function has been shown to be a marker for risk of cardiovascular events in high-risk groups, there remains considerable debate about the most appropriate way to assess this. We discuss the different clinical methods to assess endothelial function, focusing on flow-mediated dilatation (FMD) of the brachial artery, highlighting the importance of using a standardized methodology, as well as discussing the clinical limitations of using FMD in individuals

    Spin-up of low mass classical bulges in barred galaxies

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    Secular evolution is one of the key routes through which galaxies evolve along the Hubble sequence. Not only the disk undergoes morphological and kinematic changes, but also a preexisting classical bulge may be dynamically changed by the secular processes driven primarily by the bar. We study the influence of a growing bar on the dynamical evolution of a low mass classical bulge such as might be present in galaxies like the Milky Way. Using self-consistent high resolution {\it N}-body simulations, we study how an initially isotropic non-rotating small classical bulge absorbs angular momentum emitted by the bar. The basic mechanism of this angular momentum exchange is through resonances and a considerable fraction of the angular momentum is channeled through Lagrange point (-1:1) and ILR (2:1) orbits. In the phase of rapid dynamical growth, also retrograde non-resonant orbits absorb significant angular momentum. As a result of this angular momentum gain, the initially non-rotating classical bulge transforms into a fast rotating, radially anisotropic and triaxial object, embedded in the similarly fast rotating boxy bulge formed from the disk. Towards the end of the evolution, the classical bulge develops cylindrical rotation. By that time, its inner regions host a "classical bulge-bar" whose distinct kinematics could serve as direct observational evidence for the secular evolution in the galaxy. Some implications of these results are discussed briefly.Comment: 15 pages, 16 figures, accepted for publication by MNRA

    DCE-MRI for pre-treatment prediction and post-treatment assessment of treatment response in sites of squamous cell carcinoma in the head and neck

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    Background and Purpose It is important to identify patients with head and neck squamous cell carcinoma (SCC) who fail to respond to chemoradiotherapy so that they can undergo post-treatment salvage surgery while the disease is still operable. This study aimed to determine the diagnostic performance of dynamic contrast enhanced (DCE)-MRI using a pharmacokinetic model for pre-treatment predictive imaging, as well as post-treatment diagnosis, of residual SCC at primary and nodal sites in the head and neck. Material and Methods Forty-nine patients with 83 SCC sites (primary and/or nodal) underwent pre-treatment DCEMRI, and 43 patients underwent post-treatment DCE-MRI, of which 33 SCC sites had a residual mass amenable to analysis. Pre-treatment, post-treatment and %change in the mean Ktrans, kep, ve and AUGC were obtained from SCC sites. Logistic regression was used to correlate DCE parameters at each SCC site with treatment response at the same site, based on clinical outcome at that site at a minimum of two years. Results None of the pre-treatment DCE-MRI parameters showed significant correlations with SCC site failure (SF) (29/83 sites) or site control (SC) (54/83 sites). Post-treatment residual masses with SF (14/33) had significantly higher kep (p = 0.05), higher AUGC (p = 0.02), and lower % reduction in AUGC (p = 0.02), than residual masses with SC (19/33), with the% change in AUGC remaining significant on multivariate analysis. Conclusion Pre-treatment DCE-MRI did not predict which SCC sites would fail treatment, but post-treatment DCE-MRI showed potential for identifying residual masses that had failed treatment

    DCE-MRI for pre-treatment prediction and post-treatment assessment of treatment response in sites of squamous cell carcinoma in the head and neck

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    Background and Purpose It is important to identify patients with head and neck squamous cell carcinoma (SCC) who fail to respond to chemoradiotherapy so that they can undergo post-treatment salvage surgery while the disease is still operable. This study aimed to determine the diagnostic performance of dynamic contrast enhanced (DCE)-MRI using a pharmacokinetic model for pre-treatment predictive imaging, as well as post-treatment diagnosis, of residual SCC at primary and nodal sites in the head and neck. Material and Methods Forty-nine patients with 83 SCC sites (primary and/or nodal) underwent pre-treatment DCEMRI, and 43 patients underwent post-treatment DCE-MRI, of which 33 SCC sites had a residual mass amenable to analysis. Pre-treatment, post-treatment and %change in the mean Ktrans, kep, ve and AUGC were obtained from SCC sites. Logistic regression was used to correlate DCE parameters at each SCC site with treatment response at the same site, based on clinical outcome at that site at a minimum of two years. Results None of the pre-treatment DCE-MRI parameters showed significant correlations with SCC site failure (SF) (29/83 sites) or site control (SC) (54/83 sites). Post-treatment residual masses with SF (14/33) had significantly higher kep (p = 0.05), higher AUGC (p = 0.02), and lower % reduction in AUGC (p = 0.02), than residual masses with SC (19/33), with the% change in AUGC remaining significant on multivariate analysis. Conclusion Pre-treatment DCE-MRI did not predict which SCC sites would fail treatment, but post-treatment DCE-MRI showed potential for identifying residual masses that had failed treatment

    Galaxy Zoo: the dependence of morphology and colour on environment

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    We analyse the relationships between galaxy morphology, colour, environment and stellar mass using data for over 100,000 objects from Galaxy Zoo, the largest sample of visually classified morphologies yet compiled. We conclusively show that colour and morphology fractions are very different functions of environment. Both are sensitive to stellar mass; however, at fixed stellar mass, while colour is also highly sensitive to environment, morphology displays much weaker environmental trends. Only a small part of both relations can be attributed to variation in the stellar mass function with environment. Galaxies with high stellar masses are mostly red, in all environments and irrespective of their morphology. Low stellar-mass galaxies are mostly blue in low-density environments, but mostly red in high-density environments, again irrespective of their morphology. The colour-density relation is primarily driven by variations in colour fractions at fixed morphology, in particular the fraction of spiral galaxies that have red colours, and especially at low stellar masses. We demonstrate that our red spirals primarily include galaxies with true spiral morphology. We clearly show there is an environmental dependence for colour beyond that for morphology. Before using the Galaxy Zoo morphologies to produce the above results, we first quantify a luminosity-, size- and redshift-dependent classification bias that affects this dataset, and probably most other studies of galaxy population morphology. A correction for this bias is derived and applied to produce a sample of galaxies with reliable morphological type likelihoods, on which we base our analysis.Comment: 25 pages, 20 figures (+ 6 pages, 11 figures in appendices); moderately revised following referee's comments; accepted by MNRA

    Maternal eating disorders influence sex ratio at birth

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    We explored sex ratio at birth, defined as the proportion of male live births, in women with anorexia nervosa, bulimia nervosa, binge eating disorder, and eating disorders not otherwise specified-purging type (EDNOS-P) relative to a referent group in a large population based sample of 38,340 pregnant women in Norway. Poisson regressions were adjusted for mother’s age, pre-pregnancy BMI, lifetime smoking status, maternal education, income, marital status, gestational age, and parity. Lower proportions of male live births were observed in the anorexia and bulimia groups, while binge eating disorder and EDNOS-P were associated with a higher proportion of male births. These data suggest that maternal eating disorders may influence offspring sex and that the direction of effect may vary by eating disorder subtype. If confirmed, this finding could provide evidence in formulating hypotheses regarding the consequences of eating disorders and determinants of sex ratio at birth

    Tislelizumab in Patients with Previously Treated Advanced Hepatocellular Carcinoma (RATIONALE-208): A Multicenter, Non-Randomized, Open-Label, Phase 2 Trial

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    Introduction: Tislelizumab (anti-programmed cell death protein 1 antibody) showed preliminary antitumor activity and tolerability in patients with advanced solid tumors, including hepatocellular carcinoma (HCC). This study aimed to assess the efficacy and safety of tislelizumab in patients with previously treated advanced HCC. Methods: The multi-regional phase 2 study, RATIONALE-208, examined single-agent tislelizumab (200 mg intravenously every three weeks) in patients with advanced HCC with Child-Pugh A, Barcelona Clinic Liver Cancer stage B or C, and who had received one or more prior lines of systemic therapy. The primary endpoint was objective response rate (ORR), radiologically confirmed per Response Evaluation Criteria in Solid Tumors version 1.1 by Independent Review Committee. Safety was assessed in patients who received ≥1 dose of tislelizumab. Results: Between April 9, 2018 and February 27, 2019, 249 eligible patients were enrolled and treated. After a median study follow-up of 12.7 months, ORR was 13% (n = 32/249; 95% confidence interval [CI], 9–18), including five complete and 27 partial responses. Number of prior lines of therapy did not impact ORR (one prior line, 13% [95% CI, 8–20]; two or more prior lines, 13% [95% CI, 7–20]). Median duration of response was not reached. Disease control rate was 53% and median overall survival was 13.2 months. Of the 249 total patients, grade ≥3 treatment-related adverse events were reported in 38 (15%) patients; the most common was liver transaminase elevations in 10 (4%) patients. Treatment-related adverse events led to treatment discontinuation in 13 (5%) patients or dose delay in 46 (19%) patients. No deaths were attributed to the treatment per investigator assessment. Conclusion: Tislelizumab demonstrated durable objective responses, regardless of the number of prior lines of therapy, and acceptable tolerability in patients with previously treated advanced HCC

    Phosphorylation of silk fibroins improves the cytocompatibility of silk fibroin derived materials: a platform for the production of tuneable material

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    Silk fibroin demonstrates great biocompatibility and is suitable for many biomedical applications, including tissue engineering and regenerative medicine. Current research focuses on manipulating the physico-chemical properties of fibroin, and examining the effect of this manipulation on firobin's biocompatibility. Regenerated silk fibroin was modified by in vitro enzymatic phosphorylation and cast into films. Films were produced by blending, at several ratios, the phosphorylated and un-phosphorylated fibroin solutions. Fourier transform infra-red spectroscopy was used to determine the specific P–OH vibration peak, confirming the phosphorylation of the regenerated silk fibroin solution. Differential scanning calorimetry showed that phosphorylation altered the intra- and inter-molecular interactions. Further experiments demonstrated that phosphorylation can be used to tailor the hydrophylicity/hydrophobicity ratio as well as the crystalinity of silk fibroin films. Release profiling of a model drug was highly dependent on silk modification level. Cytotoxicity assays showed that exposure to lixiviates of phosphorylated films only slightly affected cellular metabolism and proliferation, although direct contact resulted in a strong direct correlation between phosphorylation level and cell proliferation. This new method for tuning silk biomaterials to obtain specific structural and biochemical features can be adapted for a wide range of applications. Phosphorylation of silk fibroins may be applied to improve the cytocompatibility of any silk-based device that is considered to be in contact with live animals or human tissues.The authors would like to acknowledge the support granted to the authors by European NOVO Project, contract no. FP7-HEALTH 2011-two-stage 278402
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