Sehleistung des Vogelauges - Perspektiven und Konsequenzen für die Haltung von Zier- und Wirtschaftsgeflügel unter Kunstlichtbedingungen

Vögel orientieren sich primär visuell und ihr visuelles System ist stark an die äußeren, natürlichen Lichtbedingungen adaptiert. Die Sehleistung des Vogelauges unterscheidet sich teilweise grundlegend von derjenigen des Menschen. Vögel verfügen im Vergleich zum Menschen über eine tetrachromatische Farbemfindung aufgrund eines zusätzlichen UV-Photorezeptors und über eine erhöhte Flickerfusionsfrequenz. Problematisch gestaltet sich das Halten von Zier- und Wirtschaftsgeflügel unter Kunstlichtbedingungen dadurch, dass einerseits keine UV-Spektren im konventionellem Kunstlicht vorhanden sind und andererseits Leuchtstofflampen unter nominaler Netzfrequenz Flackerlicht emittieren. Die sich daraus ergebenden Konsequenzen und Perspektiven werden in der vorliegenden Arbeit ausgearbeitet und dargestellt

Automatic characterization of neointimal tissue by intravascular optical coherence tomography

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Ex Vivo Assessment of Coronary Atherosclerotic Plaque by Grating-Based Phase-Contrast Computed Tomography Correlation With Optical Coherence Tomography

Objectives: The aim of this study was to determine the diagnostic accuracy of grating-based phase-contrast computed tomography (gb-PCCT) to classify and quantify coronary vessel characteristics in comparison with optical coherence tomography (OCT) and histopathology in an ex vivo setting. Materials and Methods: After excision from 5 heart specimens, 15 human coronary arteries underwent gb-PCCT examination using an experimental imaging setup consisting of a rotating molybdenum anode x-ray tube, a Talbot-Lau grating interferometer, and a single photon counting detector. Subsequently, all vessels were imaged by OCT and histopathologically processed. Optical coherence tomography, gb-PCCT, and histopathology images were manually matched using anatomical landmarks. Optical coherence tomography and gb-PCCT were reviewed by 2 independent observers blinded to histopathology. Vessel, lumen, and plaque area were measured, and plaque characteristics (lipid rich, calcified, and fibrous) were determined for each section. Measures of diagnostic accuracy were derived, applying histopathology as the standard of reference. Results: Of a total of 286 assessed cross sections, 241 corresponding sections were included in the statistical analysis. Quantitative measures derived from gb-PCCT were significantly higher than from OCT (P = 0.85 for gb-PCCT and >= 0.61 for OCT, respectively). Results of Bland-Altman analysis demonstrated smaller mean differences between OCT and histopathology than for gb-PCCT and histopathology. Limits of agreement were narrower for gb-PCCT with regard to lumen area, for OCT with regard to plaque area, and were comparable with regard to vessel area. Based on histopathology, 228/241 (94.6%) sections were classified as fibrous, calcified, or lipid rich. The diagnostic accuracy of gb-PCCT was excellent for the detection of all plaque components (sensitivity, >= 0.95;specificity, >= 0.94), whereas the results for OCT showed sensitivities of >= 0.73 and specificities of >= 0.66. Conclusions: In this ex vivo setting, gb-PCCT provides excellent results in the assessment of coronary atherosclerotic plaque characteristics and vessel dimensions in comparison to OCT and histopathology. Thus, the technique may serve as adjunct nondestructive modality for advanced plaque characterization in an experimental setting

Packaging and ecology

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The integrin ligand c(RGDf(NMe)Nal) reduces neointimal hyperplasia in a polymer-free drug-eluting stent system

The use of highly active and selective integrin ligands in combination with stent implantation is emerging as a promising alternative to the release of classical immunosuppressive drugs by current drug-eluting stents (DES), which has been associated with delayed vascular healing and late stent thrombosis. Herein we present the development and biological evaluation of the integrin ligand c(RGDf(NMe)Nal) as a potent anti-proliferative molecule that targets coronary artery smooth muscle cells (CASMCs). This peptide showed an antagonistic activity for alpha v beta 3 and alpha v beta 5 in the low-nanomolar range, and selectivity against the platelet receptor alpha IIb beta 3. In vitro, it efficiently inhibited the proliferation of CASMCs, displaying higher potency than the anti-tumor drug candidate cilengitide. This peptide was then loaded into a polymer-free bare metal stent (BMS), and its release studied at different time points. Up to seven days of elution, the peptide-coated stents retained high antiproliferative activity toward CASMCs. Finally, the peptide was examined in vivo in a polymer-free DES system in a rabbit iliac artery model. After 28 days of implantation, histopathological analysis revealed that the peptide clearly decreased neointimal growth and improved vessel healing and re-endothelialization compared with the FDA-approved Cypher DES. Our study shows that this type of lipophilic integrin ligand, when eluted from a polymer-free stent system, has the potential to successfully decrease in-stent restenosis in the absence of delayed vascular healing.Peer Reviewe