182 research outputs found

    A retrospective analysis of the accuracy of radioactively labeled autologous leukocytes in patients with infected prosthetic joints

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    BACKGROUND: Labeled leukocyte scintigraphy (LS) is considered a valuable tool in preoperative diagnosis of prosthetic joint infections (PJI). The aim of this study was to determine the accuracy of LS combined with bone marrow scintigraphy (BMS), as well as inflammation markers CRP and WBC, in detecting infection in patients with prosthetic joints. MATERIAL AND METHODS: This study included patients suspected of having PJI between January and September 2013 at the Vienna General Hospital who underwent imaging with 99mTc-HMPAO labeled autologous leukocytes and subsequent BMS. Diagnostic accuracy was assessed in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: A total of 48 patients were included. The most common joint investigated was knee (25), followed by hip (9), shoulder (2), and elbow (1). Other parts of the body investigated included the femur (6), tibia (2), leg (2), and foot (1). The pathogens most frequently isolated included Staphylococcus epidermidis and Candida albicans. The sensitivity of LS was 60%, specificity 97%, PPV 86% and NPV 90%. Overall accuracy was calculated to be 90%. CONCLUSIONS: This study was able to demonstrate that 99mTc-HMPAO labeled autologous leukocytes in patients presenting with symptoms of PJI is accurate. In contrast, however, inflammation markers CRP and WBC are not accurate pre-diagnostic markers for PJI

    Adaptive planar integrierte Freiraum-optische Systeme

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    Planar integrierte Freiraum-optische Systeme sind für eine Vielzahl an Anwendungen sehr gut geeignet. Dazu gehören die optische Verbindungstechik und Sicherheitsanwendungen. Durch die Integration adaptiver Flüssigkristall-elemente (LC-Elemente) können wir hier zum ersten Mal dynamische Funktionen in solchen mikrooptischen Systemen demonstrieren

    Continuously variable diffraction gratings using electroconvection in liquid crystals for beam steering applications

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    There is a great technological need for the development of devices capable of producing wide-angle and efficient, transmissive optical beam steering. In this article, variable pitch phase diffraction gratings using electroconvection in liquid crystals are considered for applications in electrically controllable beam-steerers. The devices contain thin layers of nematic liquid crystal mixtures of negative dielectric anisotropy, which are doped with different concentrations of an ionic species to determine the effect of conductivity on the beam-steering characteristics. The devices are seen to act as continuously variable diffraction gratings, where the pitch increases with the frequency of the applied electric field. The second order diffraction peak is found to be the most efficient, with absolute efficiency ranging from 5% to 15%, and continuous steering from 4° to 8° within 20 μm spaced devices. Devices with thinner layers of liquid crystal were also examined; these demonstrated wider angle steering but had substantial losses of efficiency due to lowering of optical contrast. Suggestions for possible methodologies for optimizing such devices are discussed

    Lack of effect of dihydroergotamine on endothelial and smooth muscle cell proliferation and endothelial cell prostanoid production

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    The most important effect of dihydroergotamine is venoconstriction, but certain metabolic effects and changes in vessel prostanoid activity have also been suggested. In this study endothelial cell production of 6-keto PGF 1α and TxB 2 was quantitated in vitro. No evidence of altered prostanoid production was noted after incubation with dihydroergotamine (exposure ranging from 5×10 −3 to 5×10 −7 g/l). Similarly, no effect of dihydroergotamine on the growth rates of endothelial cells or smooth muscle cells in vitro was documented.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42798/1/18_2005_Article_BF01941713.pd
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