191 research outputs found

    Structure of the Sentinel Granodiorite, Yosemite National Park, California

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    Evaluation of Endothelial Cells Differentiated from Amniotic Fluid-Derived Stem Cells

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    Amniotic fluid holds great promise as a stem cell source, especially in neonatal applications where autologous cells can be isolated and used. This study examined chemical-mediated differentiation of amniotic fluid-derived stem cells (AFSC) into endothelial cells and verified the function of AFSC-derived endothelial cells (AFSC-EC). AFSC were isolated from amniotic fluid obtained from second trimester amnioreduction as part of therapeutic intervention from pregnancies affected with twin-twin transfusion syndrome. Undifferentiated AFSC were of normal karyotype with a subpopulation of cells positive for the embryonic stem cell marker SSEA4, hematopoietic stem cell marker c-kit, and mesenchymal stem cell markers CD29, CD44, CD73, CD90, and CD105. Additionally, these cells were negative for the endothelial marker CD31 and hematopoietic differentiation marker CD45. AFSC were cultured in endothelial growth media with concentrations of vascular endothelial growth factor (VEGF) ranging from 1 to 100 ng/mL. After 2 weeks, AFSC-EC expressed von Willebrand factor, endothelial nitric oxide synthase, CD31, VE-cadherin, and VEGF receptor 2. Additionally, the percentage of cells expressing CD31 was positively correlated with VEGF concentration up to 50 ng/mL, with no increase at higher concentrations. AFSC-EC showed a decrease in stem cells markers c-kit and SSEA4 and were morphologically similar to human umbilical vein endothelial cells (HUVEC). In functional assays, AFSC-EC formed networks and metabolized acetylated low-density lipoprotein, also characteristic of HUVEC. Nitrate levels for AFSC-EC, an indirect measure of nitric oxide synthesis, were significantly higher than undifferentiated controls and significantly lower than HUVEC. These results indicate that AFSC can differentiate into functional endothelial-like cells and may have the potential to provide vascularization for constructs used in regenerative medicine strategies

    Amniotic fluid-derived stem cells for cardiovascular tissue engineering applications

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    Recent research has demonstrated that a population of stem cells can be isolated from amniotic fluid removed by amniocentesis that are broadly multipotent and non-tumorogenic. These amniotic fluid-derived stem cells (AFSC) could potentially provide an autologous cell source for treatment of congenital defects identified during gestation, particularly cardiovascular defects. In this review, the various methods of isolating, sorting and culturing AFSC are compared, along with techniques for inducing differentiation into cardiac myocytes and endothelial cells. Though research has not demonstrated complete and high yield cardiac differentiation, AFSC have been shown to effectively differentiate into endothelial cells and can effectively support cardiac tissue. Additionally, several tissue engineering and regenerative therapeutic approaches for the use of these cells in heart patches, injection after myocardial infarction, heart valves, vascularized scaffolds and blood vessels are summarized. These applications show great promise in the treatment of congenital cardiovascular defects, and further studies of isolation, culture, and differentiation of AFSC will help to develop their use for tissue engineering, regenerative medicine, and cardiovascular therapies

    The acute effects of a lunch containing capsaicin on energy and substrate utilisation, hormones, and satiety

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    BACKGROUND: Addition of capsaicin to the diet has been shown to increase satiety and thermogenesis. The effects of capsaicin on ghrelin, peptide YY (PYY) and glucagon-like peptide 1 (GLP-1), in relation to changes in hunger and satiety are unknown. AIM: To test the acute effects of a lunch containing capsaicin on gut derived hormones (GLP-1, ghrelin, and PYY), energy expenditure (EE), substrate oxidation and satiety at lunch in the postprandial state. METHODS: Thirty subjects (age: 31 +/- 14 years, BMI: 23.8 +/- 2.8 kg/m(2)) were studied twice in a crossover design. After 30 min resting on a bed, resting metabolic rate was measured by a ventilated hood system. Subsequently lunch (35% of daily energy intake) was served. The two lunch conditions were: (1) lunch without capsaicin and (2) lunch with capsaicin (CAPS). The macronutrient composition (energy percentage) of the lunches was 60% carbohydrates, 10% protein and 30% fat. During 3 h after the lunch diet-induced thermogenesis was measured. Furthermore, anchored 100 mm visual analogue scales on the appetite profile were collected (t = 0, 30, 60, 120, 150, 180 and 240) and blood samples were taken for analysis of GLP-1, PYY, and ghrelin concentrations (t = 0, 45, 60, 120, and 180). RESULTS: Satiety and EE were not different after CAPS lunch as compared to the control lunch. Fifteen minutes after lunch CAPS lunch increased GLP-1 (p < 0.05) and tended to decrease ghrelin (p = 0.07) as compared to the control lunch. PYY responses were not different between the CAPS lunch and the control lunch. CONCLUSIONS: An acute lunch containing capsaicin had no effect on satiety, EE, and PYY, but increased GLP-1 and tended to decrease ghrelin

    Neural networks as spatio-temporal pattern-forming systems

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    Hippocampal Mechanisms for the Segmentation of Space by Goals and Boundaries

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    G. I. Gurdjieff’s piano music and its application in and outside “The Work”*

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    Gurdjieff (c. 1866–1949) wrote a diverse collection of piano pieces at his “Institute for the Harmonious Development of Man” at the Chateau du PrieurĂ© d’ Avon at Fontainebleau near Paris in a unique collaboration with pupil Thomas de Hartmann, a Ukrainian composer. This music was composed most intensely between the years 1925 and 1927, after Gurdjieff’s near-fatal car accident of 1924 when all work on his “Movements” or “sacred dances” had ceased. Thus this music was not written for the Movements but for other spiritual purposes. Gurdjieff would whistle, sing, and tap Eastern-sounding melodies and rhythms, and de Hartmann was required to immediately transform these indications into written Western notation, adding suitable harmonies. Like Gurdjieff’s teaching overall, the piano music is best described as a blending of Eastern and Western elements. In Gurdjieff’s lifetime this music was not published or recorded, and was mostly performed within his circle of pupils, as is appropriate within an initiatory and personally transmitted spiritual teaching. This article explores the Gurdjieff—de Hartmann music and its relationship to Gurdjieff’s overall esoteric teachings. There will also be an examination of how Gurdjieff groups and musicians continue to keep alive this music today, and it will be shown that the large number of recordings released represent its greatest cultural penetration into wider society. Currently hundreds of these recordings are available though, interestingly, most “Work” members are critical of them, arguing that the music only has value when experienced live and in a Work context
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