α8 Integrin in glomerular mesangial cells and in experimental glomerulonephritis

α8 Integrin in glomerular mesangial cells and in experimental glomerulonephritis.BackgroundMesangial cell (MC) proliferation and extracellular matrix accumulation are typical responses of renal glomeruli to injury. Extracellular matrix components are known to affect MC behavior, which is mediated primarily via integrin receptors of the β1 family. In addition to α1, α3, α5, and α6 chains of β1 integrins, recent studies have shown the α8 chain to be expressed in glomeruli and renal vasculature. α8β1 can serve as a receptor for fibronectin, which is abundant in the mesangium. We investigated the glomerular expression pattern of the α8 chain in renal tissues of mouse, rat, and humans as well as in cultured MCs. In addition, the regulation of α8 expression in MCs was studied in culture and in nephritic rats.MethodsThe expression of α8 protein in kidney tissue and cultured MCs was investigated by immunohistochemistry, immunocytochemistry, and Western blotting. The effects of TGF-β1 on α8 mRNA levels in MCs were studied by Northern blot analysis. In addition, time course studies of glomerular abundance and localization of α8 were performed in rats with mesangioproliferative anti-Thy1.1 nephritis.ResultsIn tissue sections of normal human, rat, and mouse kidney, we found strong immunohistochemical staining for α8 in the mesangium and in the media of renal arterioles. Double staining for α8 and Thy1.1, a surface antigen of rat MCs, showed α8 to be specifically expressed in MCs but not in glomerular endothelial and epithelial cells. In anti-Thy1.1 nephritis of rats, the glomerular abundance of α8 protein was reduced in the early mesangiolytic phase but was increased greatly with subsequent MC proliferation, peaking at day 6 of disease. At later stages of this reversible form of nephritis, the number of MCs and the extent mesangial α8 staining declined to control levels. Cell culture experiments revealed that freshly plated MCs organize α8 into focal contacts within one hour after attachment to fibronectin and vitronectin substrata, showing colocalization with focal contact proteins vinculin and talin. Stimulation of MCs with transforming growth factor-β1 led to increases of α8 mRNA and protein levels.ConclusionsThese results show that in human, rat, and mouse glomeruli, α8 integrin is strongly and exclusively expressed in MCs. Gene expression of α8 is regulated in cultured MCs, and α8 protein abundance is regulated in vivo and in MC culture. It is currently unclear what functional properties this integrin receptor protein has with regard to MC anchorage to extracellular matrix and modulation of the MC phenotype in normal and diseased glomeruli. However, in view of its abundance in the mesangium, α8β1 integrin could be an important MC receptor of matrix ligands and may play a role in the embryology, physiology, and pathophysiology of the glomerular capillary tuft

The liver transplant waiting list—a single-center analysis

At this transplant center 1340 patients were entered on the liver transplant waiting list during the first 25 months (October 1987 to November 1989) after the initiation of the UNOS allocation system for liver grafts. Of these 972 (72.5%) of the patients received a graft, 120 (9.0%) died waiting for a graft, 109 (8.1%) remained on the active list as of the study endpoint of December 15, 1989, 123 (9.2%) were withdrawn from candidacy, and 16 (1.2%) received a transplant at another center. A total of 1201 patients were candidates for a first graft. Of the 812 primary candidates who received a graft, 64.8% received their graft within one month of entry on the waiting list. Of the 109 primary candidates who died before a graft could be found, 79.0% died within a month of entry onto the waiting list. At time of transplantation, 135 (16.6%) primary recipients of a graft were UNOS class 1, 326 (40.1%) were UNOS class 2, 190 (23.4%) were UNOS class 3, and 161 (19.8%) were UNOS class 4. Actuarial survival rates (percentage) at 6 months for recipients in UNOS class 1, class 2, class 3, and class 4 were 88.7±2.9, 82.6+2.1, 78.4±3.2, and 68.4±3.9, respectively (P<0.001). At the time of death of recipients who failed to get a graft, 6 (5.5%) were UNOS class 1, 14 (12.8%) were UNOS class 2, 23 (21.1%) were UNOS class 3, and 66 (60.6%) were UNOS class 4. These results indicate that a high proportion of liver transplant candidates are in urgent need of a graft and that the UNOS system succeeds in giving these patients high priority. However patient mortality on the waiting list and after transplantation would lessen significantly if more patients with end-stage liver disease were referred to the transplant center in a timely manner before their condition reaches the point where the probability of survival is diminished. © 1991 by Williams & Wilkins

Analysis of the NGXO Telescope X-Ray Hartmann Data

Next Generation X-Ray Optics (NGXO) team at the Goddard Space Flight Center (GSFC) has been developing a new silicon-based grazing incidence mirror technology for future high resolution x-ray astronomical missions. Recently, the GSFC team completed the construction of first few mirror modules that contain one pair of mirrors. One of the mirror pairs was tested in GSFC 600-m long beamline facility and Panter (Neuried, Germay) 120-m long x-ray beamline facility. Both full aperture x-ray tests, Hartmann tests, and focal plane sweeps were completed. In this paper we present the data analysis process and compare the results from our models to measured x-ray centroid data, x-ray performance data, and out of focus images of the mirror pair

The imaging properties of the Gas Pixel Detector as a focal plane polarimeter

X-rays are particularly suited to probe the physics of extreme objects. However, despite the enormous improvements of X-ray Astronomy in imaging, spectroscopy and timing, polarimetry remains largely unexplored. We propose the photoelectric polarimeter Gas Pixel Detector (GPD) as an instrument candidate to fill the gap of more than thirty years of lack of measurements. The GPD, in the focus of a telescope, will increase the sensitivity of orders of magnitude. Moreover, since it can measure the energy, the position, the arrival time and the polarization angle of every single photon, allows to perform polarimetry of subsets of data singled out from the spectrum, the light curve or the image of source. The GPD has an intrinsic very fine imaging capability and in this work we report on the calibration campaign carried out in 2012 at the PANTER X-ray test facility of the Max-Planck-Institut f\"ur extraterrestrische Physik of Garching (Germany) in which, for the first time, we coupled it to a JET-X optics module with a focal length of 3.5 m and an angular resolution of 18 arcsec at 4.5 keV. This configuration was proposed in 2012 aboard the X-ray Imaging Polarimetry Explorer (XIPE) in response to the ESA call for a small mission. We derived the imaging and polarimetric performance for extended sources like Pulsar Wind Nebulae and Supernova Remnants as case studies for the XIPE configuration, discussing also possible improvements by coupling the detector with advanced optics, having finer angular resolution and larger effective area, to study with more details extended objects.Comment: Accepted for publication in The Astrophysical Journal Supplemen

First Light Measurements of Capella with the Low Energy Transmission Grating Spectrometer aboard the Chandra X-ray Observatory

We present the first X-ray spectrum obtained by the Low Energy Transmission Grating Spectrometer (LETGS) aboard the Chandra X-ray Observatory. The spectrum is of Capella and covers a wavelength range of 5-175 A (2.5-0.07 keV). The measured wavelength resolution, which is in good agreement with ground calibration, is $\Delta \lambda \simeq$ 0.06 A (FWHM). Although in-flight calibration of the LETGS is in progress, the high spectral resolution and unique wavelength coverage of the LETGS are well demonstrated by the results from Capella, a coronal source rich in spectral emission lines. While the primary purpose of this letter is to demonstrate the spectroscopic potential of the LETGS, we also briefly present some preliminary astrophysical results. We discuss plasma parameters derived from line ratios in narrow spectral bands, such as the electron density diagnostics of the He-like triplets of carbon, nitrogen, and oxygen, as well as resonance scattering of the strong Fe XVII line at 15.014 A.Comment: 4 pages (ApJ letter LaTeX), 2 PostScript figures, accepted for publication in ApJ Letters, 200

Mehanička svojstva i mikrostrukturna karakterizacija Au-Pt dentalne slitine

Development of a dental alloy with high Au content is based on the ternary system of Au-Pt-Zn with a nominal composition of 86,9Au-9,9Pt-1,5Zn, and about 1,5 wt.% micro-alloying elements (In, Ir, Rh). The results analyses of different heat-treated states showed that the optimal mechanical properties and hardness of an Au-Pt-Zn alloy can be reached with combinations of heat treatment for 20 minutes at 723 K and then slowly cooling, if the alloy was annealed at 1223 K for 30 minutes and the water quenched. Research results confirmed that the microstructure of the Au-Pt-Zn alloy consists of two phases: _1-phase rich in Au (main phase) and _2-phase rich in Pt (minor phase). During XRD analysis and use of the Rietveld method, it was found that the _1-phase content is about 98,5 wt.% while the content of _2-phase is 1,5 wt.%. STA analyses show that the Au-Pt-Zn alloy has a solidus temperature of about 1292 K and a liquidus temperature of about 1412 K.Razvoj dentalne slitine s visokim sadržajem zlata zasnovan je na ternarnom sustavu Au-Pt-Zn s nominalnim sastavom 86,9Au-9,9Pt-1,5Zn i oko 1,5 mas. % mikrolegirajučih elemenata (In, Ir, Rh). Rezultati analize su pokazali da se u slučaju slitine odžarene kod 1223 K u trajanju od 30 minuta i zakaljena u vodi optimalna mehanička svojstva i tvrdoća Au-Pt-Zn slitine mogu postići kombinacijom toplinske obrade na 720 oC u trajanju 20 minuta s naknadnim sporim hlađenjem. Rezultati istraživanja su potvrdili da se mikrostruktura Au-Pt-Zn slitine sastoji od dvije faze: _1-faze bogate sa zlatom (primarna faza) i _2 - faze bogate s platinom (sekundarna faza). Tijekom XRD analize i primjenom Rietveldove metode utvrđeno je da je sadržaj _1-faze oko 98,5 mas. %, dok je sadržaj _2-faze iznosio oko 1,5 mas. %. STA analiza je pokazala da je Au-Pt-Zn slitina imala solidus temperaturu oko 1292 K, a likvidus temperaturu oko 1412 K

Economy-wide benefits and costs of local-level energy transition in Austrian Climate and Energy Model Regions

To achieve a low-carbon transition in the electricity sector, countries combine national-scale policies with regional renewable electricity (RES-E) initiatives. Taking Austria as an example, we investigate the economy-wide effects of implementing national-level feed-in tariffs alongside local-level ‘climate and energy model (CEM) regions’, taking account of policy externalities across the two governance levels. We distinguish three types of CEM regions by means of a cluster analysis and apply a sub-national Computable General Equilibrium (CGE) model to investigate two RES-E scenarios. We find that whether the net economic effects are positive or negative depends on three factors: (i) RES-E potentials, differentiated by technology and cluster region; (ii) economic competitiveness of RES-E technologies relative to each other and to the current generation mix; and (iii) support schemes in place which translate into policy costs. We conclude that the focus should mainly be on economically competitive technologies, such as PV and wind, to avoid unintended macroeconomic side-effects. To achieve that, national support policies for RES-E have to be aligned with regional energy initiatives

Contemporary Dental Ceramics

The aim of this study was to provide an overview of evolution of ceramic systems and future perspectives related to computer-aided design and computer-aided manufacturing (CAD/CAM) technology. Dental ceramics were introduced to restorative dentistry at the beginning of the XX century as porcelain jacket crowns. However, their limited use in clinical practice was mainly associated to the mechanical shortcomings. In the early sixties porcelain-fused to-metal restorations were developed and for years have represented the “gold standard”, thanks to their good mechanical properties and to somewhat satisfactory esthetics. In the last thirty years, the growing demand for highly esthetic restorations has led to development of new all-ceramic materials and techniques. All-ceramic restorations combine esthetic veneering porcelains (consisting of a glass and a crystalline phase of fluoroapatite, aluminum oxide, or leucite) with strong ceramic cores, mainly made of lithium-disilicate, aluminum-oxide or zirconium-oxide. The most common complication is fracture that can initiate from several different sites on the surface, at interfaces, or within the material. While conventional methods of ceramic fabrication usually contain internal porosity, CAD/CAM technology ensures almost no internal defects. Such improvements in ceramic processing have allowed better structural reliability and greatly contributed to the success of all ceramic systems

RNA editing signature during myeloid leukemia cell differentiation

Adenosine deaminases acting on RNA (ADARs) are key proteins for hematopoietic stem cell self-renewal and for survival of differentiating progenitor cells. However, their specific role in myeloid cell maturation has been poorly investigated. Here we show that ADAR1 is present at basal level in the primary myeloid leukemia cells obtained from patients at diagnosis as well as in myeloid U-937 and THP1 cell lines and its expression correlates with the editing levels. Upon phorbol-myristate acetate or Vitamin D3/granulocyte macrophage colony-stimulating factor (GM-CSF)-driven differentiation, both ADAR1 and ADAR2 enzymes are upregulated, with a concomitant global increase of A-to-I RNA editing. ADAR1 silencing caused an editing decrease at specific ADAR1 target genes, without, however, interfering with cell differentiation or with ADAR2 activity. Remarkably, ADAR2 is absent in the undifferentiated cell stage, due to its elimination through the ubiquitin–proteasome pathway, being strongly upregulated at the end of the differentiation process. Of note, peripheral blood monocytes display editing events at the selected targets similar to those found in differentiated cell lines. Taken together, the data indicate that ADAR enzymes play important and distinct roles in myeloid cells