5,512 research outputs found

    Angiogenesis-dependent and independent phases of intimal hyperplasia.

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    BACKGROUND: Neointimal vascular smooth muscle cell (VSMC) proliferation is a primary cause of occlusive vascular disease, including atherosclerosis, restenosis after percutaneous interventions, and bypass graft stenosis. Angiogenesis is implicated in the progression of early atheromatous lesions in animal models, but its role in neointimal VSMC proliferation is undefined. Because percutaneous coronary interventions result in induction of periadventitial angiogenesis, we analyzed the role of this process in neointima formation. METHODS AND RESULTS: Local injury to the arterial wall in 2 different animal models induced periadventitial angiogenesis and neointima formation. Application of angiogenesis stimulators vascular endothelial growth factor (VEGF-A165) or a proline/arginine-rich peptide (PR39) to the adventitia of the injured artery induced a marked increase in neointimal thickening beyond that seen with injury alone in both in vivo models. Inhibition of either VEGF (with soluble VEGF receptor 1 [sFlt1]) or fibroblast growth factor (FGF) (with a dominant=negative form of FGF receptor 1 [FGF-R1DN]), respectively, signaling reduced adventitial thickening induced by VEGF and PR39 to the level seen with mechanical arterial injury alone. However, neither inhibitor was effective in preventing neointimal thickening after mechanical injury when administered in the absence of angiogenic growth factor. CONCLUSIONS: Our findings indicate that adventitial angiogenesis stimulates intimal thickening but does not initiate it

    Optical coherence tomography findings in paraneoplastic pseudovitelliform lesions in melanoma-associated retinopathy

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    Michael Javaheri1, Rahul N Khurana1, Rizwan A Bhatti1, Jennifer I Lim21Doheny Retina Institute, Doheny Eye Institute, Department of Ophthalmology, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA; 2Eye and Ear Infirmary, Department of Ophthalmology, University of Illinois, Chicago, IL, USAPurpose: To report an unusual case of paraneoplastic pseudovitelliform lesions associated with melanoma-associated retinopathy (MAR).Design: Observational case report.Methods: Retrospective review of the ophthalmic examination, fundus photography, fluorescein angiography, electroretinogram (ERG), and optical coherence tomography (OCT) of a patient with MAR.Results: A 65-year-old Caucasian man with a two-year history of metastatic melanoma was referred for evaluation of a six-month history of nyctalopia. Funduscopic examination in both eyes revealed multiple, creamy, yellow, pseudovitelliform lesions in the posterior pole, varying in size from 100–500 µm, at the level of the outer retinal/retinal pigment epithelium (RPE) junction, coalescing along the inferior portion, with overlying macular neurosensory detachments. OCT showed bilateral macular neurosensory detachments with multiple small areas of high refl ectivity at the level of the outer retinal/RPE junction. ERG demonstrated a selective loss of the b-wave and a normal a-wave under dark adapted, scotopic conditions.Conclusion: Clinicians should be aware of this atypical presentation of MAR that may include pseudovitelliform retinal findings.Keywords: cancer-associated retinopathy, melanoma-associated retinopathy, optical coherence tomography, paraneoplastic syndrome, paraneoplastic pseudovitelliform retinopath

    References

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    Metformin: safety in cardiac patients http://heart.bmj.com/content/96/2/99.full.html Updated information and services can be found at

    Interaction of Saturn's magnetosphere and its moons: 3. Time variation of the Enceladus plume

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95380/1/jgra20677.pd

    Thermoelectrics Near the Mott Localization-Delocalization Transition

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    We give an overview on current status of the theoretical research on Thermoelectricity for correlated materials. We derive the theoretical formulas which become exact at low and high temperature and discuss the intermediate temperature results. In particular, we show that within Dynamical Mean Field Theory the low temperature sign of the thermopower is not necessary the same as in LDA, and that significant non-universality is expected due to strong correlations.Comment: appeared in "Properties and Applications of Thermoelectric Materials", Edited by V. Zlatic and A.C. Hewson, Springe

    Heavy Quasi-Particle in the Two-Orbital Hubbard Model

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    The two-orbital Hubbard model with the Hund coupling is investigated in a metallic phase close to the Mott insulator. We calculate the one-particle spectral function and the optical conductivity within dynamical mean field theory, for which the effective impurity problem is solved by using the non-crossing approximation. For a metallic system close to quarter filling, a heavy quasi-particle band is formed by the Hubbard interaction, the effective mass of which is not so sensitive to the orbital splitting and the Hund coupling. In contrast, a heavy quasi-particle band near half filling disappears in the presence of the orbital splitting, but is induced again by the introduction of the Hund coupling, resulting in a different type of heavy quasi-particles.Comment: 6page, 7eps figures, to appear in J. Phys. Soc. Jp

    Periodic and Quasiperiodic Motion of an Elongated Microswimmer in Poiseuille Flow

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    We study the dynamics of a prolate spheroidal microswimmer in Poiseuille flow for different flow geometries. When moving between two parallel plates or in a cylindrical microchannel, the swimmer performs either periodic swinging or periodic tumbling motion. Although the trajectories of spherical and elongated swimmers are qualitatively similar, the swinging and tumbling frequency strongly depends on the aspect ratio of the swimmer. In channels with reduced symmetry the swimmers perform quasiperiodic motion which we demonstrate explicitely for swimming in a channel with elliptical cross section
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