302 research outputs found

    Plasma cholesterol levels and brain development in preterm newborns.

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    BackgroundTo assess whether postnatal plasma cholesterol levels are associated with microstructural and macrostructural regional brain development in preterm newborns.MethodsSixty preterm newborns (born 24-32 weeks gestational age) were assessed using MRI studies soon after birth and again at term-equivalent age. Blood samples were obtained within 7 days of each MRI scan to analyze for plasma cholesterol and lathosterol (a marker of endogenous cholesterol synthesis) levels. Outcomes were assessed at 3 years using the Bayley Scales of Infant Development, Third Edition.ResultsEarly plasma lathosterol levels were associated with increased axial and radial diffusivities and increased volume of the subcortical white matter. Early plasma cholesterol levels were associated with increased volume of the cerebellum. Early plasma lathosterol levels were associated with a 2-point decrease in motor scores at 3 years.ConclusionsHigher early endogenous cholesterol synthesis is associated with worse microstructural measures and larger volumes in the subcortical white matter that may signify regional edema and worse motor outcomes. Higher early cholesterol is associated with improved cerebellar volumes. Further work is needed to better understand how the balance of cholesterol supply and endogenous synthesis impacts preterm brain development, especially if these may be modifiable factors to improve outcomes

    Research on the Prolonged Effect of Physical Education Class on University Students: Effect Verification of the Intervention Program

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    Abstract The purpose of this study was to verify the prolonged effect of the intervention program on university students in physical education class. Subjects were 211 university students who participated in physical education class. The intervention group is comprised of 81 students (40 males, 41 females), and the control group is comprised of 128 students (80 males, 48 females). All data were obtained through questionnaires. The questionnaires consisted of personal characteristics, skills relating to bachelor's degree ability (communication skill, teamwork skill, problem-solving skill, leadership skill), and exercise behavior (the stage of exercise behavior change, self-efficacy for exercise, decisional balance). The questionnaire data were obtained "at the beginning of the semester (pre)", "at the end of the semester (post)", and "two years after the end of the semester (the two-year follow-up)". Communication program and behavior change skills were applied to the intervention group. The main finding was that the stage of exercise behavior changed in the intervention group. Comparing "pre" with "post", the ratio of students with improved stage was 51.8%; the ratio of students who maintained their stage was 37.3%; and the ratio of students whose stage worsened was 10.8%. Additionally, comparing "post" with "the two-year follow-up", the ratio of students with improved stage was 19.3%; the ratio of students who maintained their stage was 43.4%; and the ratio of students whose stage worsened was 37.3%. The results of twoway repeated measures ANOVA (group-time) showed that there were significant interactions for S. Nakayama et al. 248 "perceived benefits of exercise (Pros)", "decoding skill", "properly transmitted skill", "teamwork skill", and "leadership skill". The results of one-way repeated measures ANOVA showed that "properly transmitted skill", "teamwork skill", and "leadership skill" significantly increased on account of the intervention program post and at the two-year follow-up. These results indicate that the intervention program on university students, which consists of a communication program and behavior change skills, was partly effective for improving skills relating to bachelor's degree ability two years after the end of semester

    Compounds from Silicones Alter Enzyme Activity in Curing Barnacle Glue and Model Enzymes

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    Background: Attachment strength of fouling organisms on silicone coatings is low. We hypothesized that low attachment strength on silicones is, in part, due to the interaction of surface available components with natural glues. Components could alter curing of glues through bulk changes or specifically through altered enzyme activity. Methodology/Principal Findings: GC-MS analysis of silicone coatings showed surface-available siloxanes when the coatings were gently rubbed with a cotton swab for 15 seconds or given a 30 second rinse with methanol. Mixtures of compounds were found on 2 commercial and 8 model silicone coatings. The hypothesis that silicone components alter glue curing enzymes was tested with curing barnacle glue and with commercial enzymes. In our model, barnacle glue curing involves trypsin-like serine protease(s), which activate enzymes and structural proteins, and a transglutaminase which cross-links glue proteins. Transglutaminase activity was significantly altered upon exposure of curing glue from individual barnacles to silicone eluates. Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents. Conclusions/Significance: Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties

    Chlorotetracycline As An Indicator Of The Interaction Of Calcium With Brain Membrane Fractions

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    The fluorescence of chlorotetracycline (CTC) in the presence of synaptosomes isolated from sheep brain is selectively increased by Ca2+ under conditions in which Mg2+, Na+, K+, Li+ or choline have only a small effect. The monovalent cations release bound Ca2+ from synaptosomes, and this effect is reflected by a decrease in the CTC fluorescence. Under optimal conditions there is a near parallelism between Ca2+ and CTC binding to the synaptosomes membranes, and Li+ is the monovalent cation tested which interferes the most with the binding of both substances. These results obtained in a predominantly sucrose medium become less distinct when media simulating physiological composition are utilized, which limits the usefulness of the method. Brain mitochondria and myelin also bind Ca2+ and CTC. The ratio of the fluorescence signal (or CTC bound) to Ca2+ bound is highest of all for mitochondrial membranes, and the apparent fluorescence quantum yield of CTC is also the highest in these membranes, which suggests that the Ca2+ in these membranes is localized in a more apolar region than is the case for synaptosomes and myelin

    Solution-processed blue/deep blue and white phosphorescent organic light emitting diodes (PhOLEDs) hosted by a polysiloxane derivative with pendant mCP (1, 3-bis(9-carbazolyl)benzene)

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    The synthesis and characterization is reported of an efficient polysiloxane derivative containing the 1,3-bis(9-carbazolyl)benzene (mCP) moiety as a pendant unit on the polysiloxane backbone. In comparison with mCP, the mCP-polysiloxane hybrid (PmCPSi) has significantly improved thermal and morphological stabilities with a high decomposition temperature (Td = 523 Β°C) and glass transition temperature (Tg = 194 Β°C). The silicon–oxygen linkage of PmCPSi prevents intermolecular Ο€-stacking and ensures a high triplet energy level (ET = 3.0 eV). Using PmCPSi as a host, blue phosphorescent organic light emitting devices (PhOLEDs) effectively confine triplet excitons, with efficient energy transfer to the guest emitter and a relatively low turn-on voltage of 5.8 V. A maximum external quantum efficiency of 9.24% and maximum current efficiency of 18.93 cd/A are obtained. These values are higher than for directly analogous poly(vinylcarbazole) (PVK) based devices (6.76%, 12.29 cd/A). Good color stability over a range of operating voltages is observed. A two-component β€œwarm-white” device with a maximum current efficiency of 10.4 cd/A is obtained using a blend of blue and orange phosphorescent emitters as dopants in PmCPSi host. These results demonstrate that well-designed polysiloxane derivatives are highly efficient hosts suitable for low-cost solution-processed PhOLEDs

    Development of the Pulmonary Vein and the Systemic Venous Sinus: An Interactive 3D Overview

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    Knowledge of the normal formation of the heart is crucial for the understanding of cardiac pathologies and congenital malformations. The understanding of early cardiac development, however, is complicated because it is inseparably associated with other developmental processes such as embryonic folding, formation of the coelomic cavity, and vascular development. Because of this, it is necessary to integrate morphological and experimental analyses. Morphological insights, however, are limited by the difficulty in communication of complex 3D-processes. Most controversies, in consequence, result from differences in interpretation, rather than observation. An example of such a continuing debate is the development of the pulmonary vein and the systemic venous sinus, or β€œsinus venosus”. To facilitate understanding, we present a 3D study of the developing venous pole in the chicken embryo, showing our results in a novel interactive fashion, which permits the reader to form an independent opinion. We clarify how the pulmonary vein separates from a greater vascular plexus within the splanchnic mesoderm. The systemic venous sinus, in contrast, develops at the junction between the splanchnic and somatic mesoderm. We discuss our model with respect to normal formation of the heart, congenital cardiac malformations, and the phylogeny of the venous tributaries

    Complex life forms may arise from electrical processes

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    There is still not an appealing and testable model to explain how single-celled organisms, usually following fusion of male and female gametes, proceed to grow and evolve into multi-cellular, complexly differentiated systems, a particular species following virtually an invariant and unique growth pattern. An intrinsic electrical oscillator, resembling the cardiac pacemaker, may explain the process. Highly auto-correlated, it could live independently of ordinary thermodynamic processes which mandate increasing disorder, and could coordinate growth and differentiation of organ anlage

    MMTV-Wnt1 and -Ξ”N89Ξ²-Catenin Induce Canonical Signaling in Distinct Progenitors and Differentially Activate Hedgehog Signaling within Mammary Tumors

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    Canonical Wnt/Ξ²-catenin signaling regulates stem/progenitor cells and, when perturbed, induces many human cancers. A significant proportion of human breast cancer is associated with loss of secreted Wnt antagonists and mice expressing MMTV-Wnt1 and MMTV-Ξ”N89Ξ²-catenin develop mammary adenocarcinomas. Many studies have assumed these mouse models of breast cancer to be equivalent. Here we show that MMTV-Wnt1 and MMTV-Ξ”N89Ξ²-catenin transgenes induce tumors with different phenotypes. Using axin2/conductin reporter genes we show that MMTV-Wnt1 and MMTV-Ξ”N89Ξ²-catenin activate canonical Wnt signaling within distinct cell-types. Ξ”N89Ξ²-catenin activated signaling within a luminal subpopulation scattered along ducts that exhibited a K18+ERβˆ’PRβˆ’CD24highCD49flow profile and progenitor properties. In contrast, MMTV-Wnt1 induced canonical signaling in K14+ basal cells with CD24/CD49f profiles characteristic of two distinct stem/progenitor cell-types. MMTV-Wnt1 produced additional profound effects on multiple cell-types that correlated with focal activation of the Hedgehog pathway. We document that large melanocytic nevi are a hitherto unreported hallmark of early hyperplastic Wnt1 glands. These nevi formed along the primary mammary ducts and were associated with Hedgehog pathway activity within a subset of melanocytes and surrounding stroma. Hh pathway activity also occurred within tumor-associated stromal and K14+/p63+ subpopulations in a manner correlated with Wnt1 tumor onset. These data show MMTV-Wnt1 and MMTV-Ξ”N89Ξ²-catenin induce canonical signaling in distinct progenitors and that Hedgehog pathway activation is linked to melanocytic nevi and mammary tumor onset arising from excess Wnt1 ligand. They further suggest that Hedgehog pathway activation maybe a critical component and useful indicator of breast tumors arising from unopposed Wnt1 ligand
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