113 research outputs found

    BMP signals and the transcriptional repressor BLIMP1 during germline segregation in the mammalian embryo

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    Molecular factors and tissue compartments involved in the foundation of the mammalian germline have been mainly described in the mouse so far. To find mechanisms applicable to mammals in general, we analyzed temporal and spatial expression patterns of the transcriptional repressor BLIMP1 (also known as PRDM1) and the signaling molecules BMP2 and BMP4 in perigastrulation and early neurulation embryos of the rabbit using whole-mount in situ hybridization and high-resolution light microscopy. Both BMP2 and BMP4 are expressed in annular domains at the boundary of the embryonic disc, which—in contrast to the situation in the mouse—partly belong to intraembryonic tissues. While BMP2 expression begins at (pregastrulation) stage 1 in the hypoblast, BMP4 expression commences—distinctly delayed compared to the mouse—diffusely at (pregastrulation) stage 2; from stage 3 onwards, BMP4 is expressed peripherally in hypoblast and epiblast and in the mesoderm at the posterior pole of the embryonic disc. BLIMP1 expression begins throughout the hypoblast at stage 1 and emerges in single primordial germ cell (PGC) precursors in the posterior epiblast at stage 2 and then in single mesoderm cells at positions identical to those identified by PGC-specific antibodies. These expression patterns suggest that function and chronology of factors involved in germline segregation are similar in mouse and rabbit, but higher temporal and spatial resolution offered by the rabbit demonstrates a variable role of bone morphogenetic proteins and makes “blimping” a candidate case for lateral inhibition without the need for an allantoic germ cell niche

    Optical and structural analysis of solar selective absorbing coatings based on AlSiOx:W cermets

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    It is reported in this work the development and study of the optical and structural properties of a solar selective absorber cermet based on AlSiOx:W. A four-layer composite film structure, W/AlSiOx:W(HA)/AlSiOx:W(LA)/AlSiOx, was deposited on stainless steel substrates using the magnetron sputtering deposition method. Numerical calculations were performed to simulate the spectral properties of multilayer stacks with varying metal volume fraction cermets and film thickness. The chemical analysis was performed using X-ray photoelectron spectroscopy and the results show that in the high metal volume fraction cermet layer, AlSiOx:W(HA), about one third of W atoms are in the W-O oxidation state, another third in the Wx+ oxidation state and the last third in the W4+, W5+ and W6+ oxidation states. The X-ray diffractograms of AlSiOx:W layers show a broad peak indicating that both, W and AlSiOx, are amorphous. These results indicate that this film structure has a good spectral selective property that is suitable for solar thermal applications, with the coatings exhibiting a solar absorptance of 94-95.5% and emissivities of 8-9% (at 100 degrees C) and 10-14% (at 400 degrees C). The samples were subjected to a thermal annealing at 450 degrees C, in air, and 580 degrees C, in vacuum and showed very good oxidation resistance and thermal stability. Morphological characterizations were carried out using scanning electron microscopy and atomic force microscopy. Rutherford Backscattering experiments were also performed to analyze the tungsten depth profile.The authors acknowledge the support of the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013. The authors are also grateful to the financial support of FCT, POCI and PORL operational programs through the project POCI-01-0145-FEDER-016907 (PTDC/CTM-ENE/2882/2014), co-financed by European community fund FEDER. The authors also acknowledge GIST Japan for using the XPS-Kratos.info:eu-repo/semantics/publishedVersio

    Effect of magnesium and vitamin B6 supplementation on mental health and quality of life in stressed healthy adults: Post‐hoc analysis of a randomised controlled trial

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    Magnesium status and vitamin B6 intake have been linked to mental health and/or quality of life (QoL). In an 8‐week Phase IV randomised controlled study in individuals with low magnesemia and severe/extremely severe stress but who were otherwise healthy, greater stress reduction was achieved with magnesium combined with vitamin B6 than with magnesium alone. We present a previously unreported secondary analysis of the effect of magnesium, with and without vitamin B6, on depression, anxiety, and QoL. Adults with Depression Anxiety Stress Scales (DASS‐42) stress subscale score >18 were randomised 1:1 to magnesium + vitamin B6 combination (Magne B6¼; daily dose 300 and 30 mg, respectively) or magnesium alone (Magnespasmyl¼; daily dose 300 mg). Outcomes included changes from baseline in DASS‐42 depression and anxiety scores, and QoL (Short Form‐36 Health Survey). DASS‐42 anxiety and depression scores significantly improved from baseline to week 8 with both treatments, particularly during the first 4 weeks. Improvement in QoL continued over 8 weeks. Participants' perceived capacity for physical activity in daily life showed greater improvement with magnesium + vitamin B6 than magnesium alone (Week 4). In conclusion, magnesium supplementation, with or without vitamin B6, could provide a meaningful clinical benefit in daily life for individuals with stress and low magnesemia

    Oval Cell Response Is Attenuated by Depletion of Liver Resident Macrophages in the 2-AAF/Partial Hepatectomy Rat

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    BACKGROUND/AIMS: Macrophages are known to play an important role in hepatocyte mediated liver regeneration by secreting inflammatory mediators. However, there is little information available on the role of resident macrophages in oval cell mediated liver regeneration. In the present study we aimed to investigate the role of macrophages in oval cell expansion induced by 2-acetylaminofluorene/partial hepatectomy (2-AAF/PH) in rats. METHODOLOGY/PRINCIPAL FINDINGS: We depleted macrophages in the liver of 2-AAF/PH treated rats by injecting liposome encapsulated clodronate 48 hours before PH. Regeneration of remnant liver mass, as well as proliferation and differentiation of oval cells were measured. We found that macrophage-depleted rats suffered higher mortality and liver transaminase levels. We also showed that depletion of macrophages yielded a significant decrease of EPCAM and PCK positive oval cells in immunohistochemical stained liver sections 9 days after PH. Meanwhile, oval cell differentiation was also attenuated as a result of macrophage depletion, as large foci of small basophilic hepatocytes were observed by day 9 following hepatectomy in control rats whereas they were almost absent in macrophage depleted rats. Accordingly, real-time polymerase chain reaction analysis showed lower expression of albumin mRNA in macrophage depleted livers. Then we assessed whether macrophage depletion may affect hepatic production of stimulating cytokines for liver regeneration. We showed that macrophage-depletion significantly inhibited hepatic expression of tumor necrosis factor-α and interleukin-6, along with a lack of signal transducer and activator of transcription 3 phosphorylation during the early period following hepatectomy. CONCLUSIONS: These data indicate that macrophages play an important role in oval cell mediated liver regeneration in the 2-AAF/PH model

    LebensqualitÀt nach 10 Jahren kombinierter Pankreas-Nieren-Transplantation

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    Ergebnisse der kombinierten Pankreas-Nieren-Transplantation: Zentrumserfahrung nach 478 Operationen

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    Verfahrenswahl und Wert des PTH-Schnelltests in der Chirurgie des renalen Hyperparathyreoidismus

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