165 research outputs found
Corneal Thickness in Pigs Measured by Ultrasound Pachymetry In Vivo
The objective was to evaluate the normal thickness and diameter of the pig cornea using, under general anesthesia, 13 female, young, domestic Danish Landrace pigs. The thickness was measured, for the first time in vivo, and were: 666 μm centrally, 657 μm nasally, 713 μm inferiorly, 669 μm temporally, and 714 μm superiorly (mean values). The cornea diameters were also measured, using calipers, and were: 14.9 mm horizontally and 12.4 mm vertically (mean values). Conclusion: The pig cornea is only slightly thicker than the human cornea. However, unlike the human cornea, no significant difference in thickness exists between the central and the tempero-nasal peripheral locations of the pig cornea. The pig could prove useful as source for corneas in human xenotransplantation.
Engineered SPIONs functionalized with endothelin a receptor antagonist ameliorate liver fibrosis by inhibiting hepatic stellate cell activation
Endothelin-1/endothelin A receptor (ET-1/ETAR) pathway plays an important role in the progression of liver fibrosis by activating hepatic stellate cells (HSCs) - a key cell type involved in the pathogenesis of liver fibrosis. Inactivating HSCs by blocking the ET-1/ETAR pathway using a selective ETAR antagonist (ERA) represents a promising therapeutic approach for liver fibrosis. Unfortunately, small-molecule ERAs possess limited clinical potential due to poor bioavailability, short half-life, and rapid renal clearance. To improve the clinical applicability, we conjugated ERA to superparamagnetic iron-oxide nanoparticles (SPIONs) and investigated the therapeutic efficacy of ERA and ERA-SPIONs in vitro and in vivo and analyzed liver uptake by in vivo and ex vivo magnetic resonance imaging (MRI), HSCs-specific localization, and ET-1/ETAR-pathway antagonism in vivo. In murine and human liver fibrosis/cirrhosis, we observed overexpression of ET-1 and ETAR that correlated with HSC activation, and HSC-specific localization of ETAR. ERA and successfully synthesized ERA-SPIONs demonstrated significant attenuation in TGFβ-induced HSC activation, ECM production, migration, and contractility. In an acute CCl4-induced liver fibrosis mouse model, ERA-SPIONs exhibited higher liver uptake, HSC-specific localization, and ET-1/ETAR pathway antagonism. This resulted in significantly reduced liver-to-body weight ratio, plasma ALT levels, and α-SMA and collagen-I expression, indicating attenuation of liver fibrosis. In conclusion, our study demonstrates that the delivery of ERA using SPIONs enhances the therapeutic efficacy of ERA in vivo. This approach holds promise as a theranostic strategy for the MRI-based diagnosis and treatment of liver fibrosis.</p
Deficiency of the BMP Type I receptor ALK3 partly protects mice from anemia of inflammation
Background: Inflammatory stimuli induce the hepatic iron regulatory hormone hepcidin, which contributes to anaemia of inflammation (AI). Hepcidin expression is regulated by the bone morphogenetic protein (BMP) and the interleukin-6 (IL-6) signalling pathways. Prior results indicate that the BMP type I receptor ALK3 is mainly involved in the acute inflammatory hepcidin induction four and 72Â h after IL-6 administration. In this study, the role of ALK3 in a chronic model of inflammation was investigated. The intact, heat-killed bacterium Brucella abortus (BA) was used to analyse its effect on the development of inflammation and hypoferremia in mice with hepatocyte-specific Alk3-deficiency (Alk3fl/fl; Alb-Cre) compared to control (Alk3fl/fl) mice.
Results: An iron restricted diet prevented development of the iron overload phenotype in mice with hepatocyte-specific Alk3 deficiency. Regular diet leads to iron overload and increased haemoglobin levels in these mice, which protects from the development of AI per se. Fourteen days after BA injection Alk3fl/fl; Alb-Cre mice presented milder anaemia (Hb 16.7Â g/dl to 11.6Â g/dl) compared to Alk3fl/fl control mice (Hb 14.9Â g/dl to 8.6Â g/dl). BA injection led to an intact inflammatory response in all groups of mice. In Alk3fl/fl; Alb-Cre mice, SMAD1/5/8 phosphorylation was reduced after BA as well as after infection with Staphylococcus aureus. The reduction of the SMAD1/5/8 signalling pathway due to hepatocyte-specific Alk3 deficiency partly suppressed the induction of STAT3 signalling.
Conclusion: The results reveal in vivo, that 1) hepatocyte-specific Alk3 deficiency partly protects from AI, 2) the development of hypoferremia is partly dependent on ALK3, and 3) the ALK3/BMP/hepcidin axis may serve as a possible therapeutic target to attenuate AI
Interoperability of institutional data management systems
Motivation
• Awareness of FAIR data requirements is rising
• We have come FAR but: Interoperability is the remaining challenge for productive systems
Here we present
• Description of the existing infrastructures and interfaces at GEOMAR • Challenges to reach interoperability
• A roadmap with planned steps to g
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