University of Vienna

About: University of Vienna is a education organization based out in Vienna, Austria. It is known for research contribution in the topics: Population & Stars. The organization has 44686 authors who have published 95840 publications receiving 2907492 citations.

Defective valves and abnormal mural cell recruitment underlie lymphatic vascular failure in lymphedema distichiasis

Abstract: Lymphatic vessels are essential for the removal of interstitial fluid and prevention of tissue edema. Lymphatic capillaries lack associated mural cells, and collecting lymphatic vessels have valves, which prevent lymph backflow. In lymphedema-distichiasis (LD), lymphatic vessel function fails because of mutations affecting the forkhead transcription factor FOXC2. We report that Foxc2−/− mice show abnormal lymphatic vascular patterning, increased pericyte investment of lymphatic vessels, agenesis of valves and lymphatic dysfunction. In addition, an abnormally large proportion of skin lymphatic vessels was covered with smooth muscle cells in individuals with LD and in mice heterozygous for Foxc2 and for the gene encoding lymphatic endothelial receptor, Vegfr3 (also known as Flt4). Our data show that Foxc2 is essential for the morphogenesis of lymphatic valves and the establishment of a pericyte-free lymphatic capillary network and that it cooperates with Vegfr3 in the latter process. Our results indicate that an abnormal interaction between the lymphatic endothelial cells and pericytes, as well as valve defects, underlie the pathogenesis of LD.

Active cell death induced by the anti-estrogens tamoxifen and ICI 164 384 in human mammary carcinoma cells (MCF-7) in culture: the role of autophagy†

Abstract: Active cell death in hormone-dependent cells was studied using cultured human mammary carcinoma cells (MCF-7) treated with the anti-estrogens (AEs) tamoxifen (TAM), 4-hydroxy-tamoxifen (OH-TAM) or ICI 164 384 (10 -8 -10 -5 M) as a model. The following results were obtained. (i) In untreated MCF-7 cells a wave of replication occurred in the first 5 days of culture. All three AEs caused a dose-dependent inhibition of cell replication. (ii) TAM and OH-TAM at 10 -5 M, but not ICI 164 384, caused lytic cell death (necrosis) within 24 h, which was not inhibited by estradiol (10 -9 -10 -6 M). (iii) Lower concentrations of TAM or OH-TAM (up to 10 -6 M) or ICI 164 384 induced a more gradual appearance of cell death beginning at day 3. This type of cell death was inhibited by estradiol (10 -9 M), indicating its active nature. (iv) Nuclei showed two distinct patterns of alteration : (a) apoptosis-like condensation and fragmentation of chromatin to crescent masses abutting the nuclear envelope ; (b) condensation of the chromatin to a single, pyknotic mass in the center of the nucleus, detached from the nuclear envelope. Quantitative histological evaluation revealed the predominance of pyknosis. (v) Biochemical DNA analysis revealed that only a relatively small amount of the total DNA was finally degraded into low molecular weight fragments (20 kb and less). (vi) Active cell death, with both apoptotic and pyknotic nuclear morphology, was associated with extensive formation of autophagic vacuoles (AV). 3-Methyladenine, a known inhibitor of AV formation, partially prevented cell death as detected by nuclear changes. (vii) ICI 164 384 was about 10 times more effective than TAM or OH-TAM at inhibiting DNA synthesis, but had equal potency in inducing active cell death. It is concluded that AEs have anti-proliferative and anti-survival effects on MCF-7 human mammary cancer cells in culture. These two effects are under separate control because they differ by kinetics, dose dependence and sensitivity to the various AEs. Active cell death in MCF-7 cells seems to be initiated by autophagy, in contrast to concepts of apoptosis, and thus corresponds to autophagic/lysosomal or type II death as previously defined. This may be important because of biochemical and molecular differences between these various subtypes of active cell death.

Full range complex spectral optical coherence tomography technique in eye imaging

Abstract: We demonstrate a new implementation of complex spectral optical coherence tomography (OCT) in biomedical imaging. By reconstruction of both amplitude and phase we are able to use the negative and positive optical path differences to get images of objects of considerable thickness. An accompanying reduction of coherent noise improves the quality of the images. The property of the complex spectral OCT that permits the measurement range to be increased and permits the simultaneous use of phase and amplitude in spectral systems was not described previously. To show the potential of this technique we measured an anterior chamber of a porcine eye in vitro.

Biochemical aspects of Parkinson's disease

Abstract: The importance of the striatal dopamine (DA) deficiency and the DA substituting property of levodopa for the pathophysiology and therapy of Parkinson9s disease (PD) is reiterated. In addition, it is shown that in PD, significantly reduced DA levels are also found in the nucleus accumbens, external and internal segments of the globus pallidus, the substantia nigra reticulata, and the subthalamic nucleus. It is proposed that, in addition to the critical role played by the striatal DA loss, the DA changes in the extrastriatal nuclei of the basal ganglia are importantly involved in the pathophysiologic mechanisms resulting in the parkinsonian movement disorder, and that the therapeutic and/or side effects of DA substitution therapy may, in part, be mediated through these brain regions which, like the striatum, suffer DAergic deafferentation in PD. From observations in brain of patients with secondary parkinsonism, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine parkinsonism in the rhesus monkey, as well as the regional DA transporter distribution in the primate substantia nigra, it is concluded that PD may be caused by any exogenous and/or endogenous toxin using the transporter system for DA and to some degree the other brain monoamines (noradrenaline, serotonin), to enter, and damage, the respective monoamine neurons. Based on converging evidence, the view is advanced that endogenous, genetically based(excessive) formation, or accumulation, of toxic DA transporter substrates, such as isoquinoline or β-carboline derivatives, may in fact represent the primary cause of substantia nigra cell degeneration in patients with PD.

The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory

Abstract: The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in 2014 July. It pursues three core programs: the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2), Mapping Nearby Galaxies at APO (MaNGA), and the Extended Baryon Oscillation Spectroscopic Survey (eBOSS). As well as its core program, eBOSS contains two major subprograms: the Time Domain Spectroscopic Survey (TDSS) and the SPectroscopic IDentification of ERosita Sources (SPIDERS). This paper describes the first data release from SDSS-IV, Data Release 13 (DR13). DR13 makes publicly available the first 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA. It includes new observations from eBOSS, completing the Sloan Extended QUasar, Emission-line galaxy, Luminous red galaxy Survey (SEQUELS), which also targeted variability-selected objects and X-ray-selected objects. DR13 includes new reductions of the SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification, and new reductions of the SDSS-III APOGEE-1 data, improving stellar parameters for dwarf stars and cooler stars. DR13 provides more robust and precise photometric calibrations. Value-added target catalogs relevant for eBOSS, TDSS, and SPIDERS and an updated red-clump catalog for APOGEE are also available. This paper describes the location and format of the data and provides references to important technical papers. The SDSS web site, http://www.sdss.org, provides links to the data, tutorials, examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ∼6 yr operations of SDSS-IV.