418 research outputs found

    Ruptured aneurysm of the ulnar artery in a woman with neurofibromatosis

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    A 61-year-old woman with neurofibromatosis type 1 (Recklinghausen's disease) was referred for massive swelling of the right forearm, pain, increasing numbness, and impaired movement of the fingers. Angiography demonstrated a 13- × 11-mm aneurysm and a capped rupture of the ulnar artery. Because of the complicated soft-tissue condition, interventional treatment was indicated. Two 360° coils were placed for embolization of the ruptured aneurysm. Arterial involvement in neurofibromatosis is a well known but infrequent occurrence. Stenotic lesions predominate. Aneurysmal defects are less common, and rupture of peripheral arteries is exceptional

    Functional integration of natural killer cells in a microfluidically perfused liver on-a-chip model.

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    OBJECTIVE The liver acts as an innate immunity-dominant organ and natural killer (NK) cells, are the main lymphocyte population in the human liver. NK cells are in close interaction with other immune cells, acting as the first line of defense against pathogens, infections, and injury. A previously developed, three-dimensional, perfused liver-on-a-chip comprised of human cells was used to integrate NK cells, representing pivotal immune cells during liver injury and regeneration. The objective of this study was to integrate functional NK cells in an in vitro model of the human liver and assess utilization of the model for NK cell-dependent studies of liver inflammation. RESULTS NK cells from human blood and liver specimen were isolated by Percoll separation with subsequent magnetic cell separation (MACS), yielding highly purified blood and liver derived NK cells. After stimulation with toll-like-receptor (TLR) agonists (lipopolysaccharides, Pam3CSK4), isolated NK cells showed increased interferon (IFN)-gamma secretion. To study the role of NK cells in a complex hepatic environment, these cells were integrated in the vascular compartment of a microfluidically supported liver-on-a-chip model in close interaction with endothelial and resident macrophages. Successful, functional integration of NK cells was verified by immunofluorescence staining (NKp46), flow cytometry analysis and TLR agonist-dependent secretion of interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha. Lastly, we observed that inflammatory activation of NK cells in the liver-on-a-chip led to a loss of vascular barrier integrity. Overall, our data shows the first successful, functional integration of NK cells in a liver-on-a-chip model that can be utilized to investigate NK cell-dependent effects on liver inflammation in vitro

    Molecular Features and Clinical Implications in Gastric Cancer

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    Living Donor Liver Transplantation for Intrahepatic Cholangiocarcinoma

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    Intrahepatic cholangiocarcinoma is in most transplant regions a contraindication for liver transplantation, even ruling out an active waiting list registration. However, recent studies showed that well-selected patients after a neo-adjuvant treatment benefit from liver transplantation with good long-term outcomes. The role of living donor liver transplantation is unclear for this indication. The current study focuses on LDLT for intrahepatic cholangiocarcinoma

    Lifetime of magnetic excitations in supported ferromagnetic and antiferromagnetic spin-1/2 Heisenberg chains

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    The lifetime of magnetic excitations in finite 1D-supported Heisenberg chains of magnetic atoms is studied theoretically for a model system formed of S = 1/2 spins. Both ferromagnetic and antiferromagnetic cases are considered as well as open chains and rings of atoms. Different chain lengths are considered allowing extrapolation to infinite chains. All the excited magnetic states in the finite chains and rings are studied, not only the spin-wave mode. The magnetic excitations decay by electron-hole pair creation in the substrate. As the main result, for all the systems considered, the decay rate appears to vary approximately proportionally to the excitation energy of the state, with a proportionality constant independent of the strength of the Heisenberg exchange term. In certain finite systems, a stable state is evidenced at low energy, associated with a special spin coupling structure. © 2012 American Physical Society.Peer Reviewe

    Local Haemodynamics and Shear Stress in Cuffed and Straight PTFE-venous Anastomoses: An in-vitro Comparison using Particle Image Velocimetry

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    AbstractObjectives: To use particle image velocimetry (PIV) to study the haemodynamics and shear stress associated with cuffed and straight PTFE-venous anastomoses.Methods: Silastic models of a straight and cuffed (Venaflo™) PTFE-venous anastomoses were attached to a pulsatile flow ‘Berlin Heart’ circuit filled with glycerine/water and hollow glass tracer spheres. Instantaneous velocity fields were obtained PIV and shear rates and patterns calculated from frame-by-frame analysis.Results: A high velocity jet struck the anastomotic ‘floor’ and was deflected toward the venous outflow. Shear stresses near the floor were significantly higher, in the straight anastomosis. Sites of high shear stress correlated well with the known sites of intimal hyperplasia.Conclusions: A cuffed anastomosis type may be favourable in terms of local haemodynamics so enhancing the long-term patency of PTFE-venous grafts
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