Forschungsschwerpunkte der paläobotanik und palynologie der Universität Wien

An initial accent on the investigation of megafossils by some well-known Austrian paleobotanists (like Ettinghausen, Stur, Unger) changed with time to a higher degree of research on the histology and anatomy of fossil plants, especially of wood and cuticles by the late E. Hofmann. Due to the large quantity of spores and pollen grains in peat, brown coal, salt rocks, phosphorites, clay and shales in Austria, the major topic of investigation at the present time is clearly devoted to palynology. Quaternary, Neogene and Permo-Triassic microfloras occupy the first place in research. Concerning the determination of pollen and morphologic studies of a selection of modern comparison species by all kinds of light and electron microscopy have been initiated to find out whether biospecific determination could be carried out in the Quaternary and Neogene. An example of pollen-morphological features within the genus Pinus is presented.The microflora of Upper Permian and Triassic sediments of the east Alpine salt rocks, their environment and inclusions receive comprehensive microphotographic documentation and will be backed from a stratigraphic point of view by sulphur-isotope investigations, which promise to be of great value in dating the Permo-Triassic boundary.     

18β-甘草次酸抑制微动脉平滑肌细胞外向电流

本文旨在观察18β-甘草次酸(18β-glycyrrhetinic acid,18βGA)对微动脉平滑肌细胞膜电流的影响。分离出豚鼠小脑前下动脉(anterior inferior cerebellar artery,AICA)和肠系膜动脉(mesenteric artery,MA)后,用酶消化法制备单个血管平滑肌细胞(vascular smooth muscle cells,VSMCs),应用全细胞膜片钳技术记录平滑肌细胞外向电流的变化。结果显示:(1)1mmol/L4氨基吡啶(4-aminopyridine,4-AP)和1mmol/L tetraethylammonium(TEA)都可以部分抑制微动脉平滑肌细胞的外向电流。(2)18βGA电压和浓度依赖性地抑制微动脉平滑肌细胞外向电流。18βGA主要抑制0～+40mV电压区间的激活电流,其中对+40mV激活电流的抑制作用最强。10、30和100μmol/L18βGA对AICA平滑肌细胞外向电流(+40mV)的抑制率分别为(25.3±7.1)%、(43.1±10.4)%和(68.4±3.9)%,对MA平滑肌细胞外向电流(+40mV)的抑制率分别为(13.2±...     

Nutrient composition,ruminal degradability and whole tract digestibility of whole crop maize silage from nine current varieties

Since maize silage is an important forage in cattle nutrition, it is important to know its nutritive value. Much effort is put into breeding maize, and several new varieties are introduced on the market every year. This requires periodical analyses of the nutritive value of current maize varieties for the formulation of cattle rations. The aim of this study was to examine the nutritive value of whole crop maize silage (WCMS) from nine maize varieties in 3 consecutive years. For the analysis of nutrient composition and ruminal degradability of organic matter (OM), crude protein (CP), neutral detergent fibre (aNDFom) and non-fibre carbohydrates (NFC), varieties were harvested at three harvest dates (50%, 55% and 60% dry matter content in ear). Due to capacity limitations, the digestibility of WCMS was tested only for the middle harvest date. The CP and acid detergent fibre (ADFom) content was affected (p < 0.05) while aNDFom and NFC content was not influenced by variety. With advancing maturity, CP, aNDFom and ADFom content declined while NFC content increased. Variety influenced effective ruminal degradability (ED) of nutrients, except for CP. The ED of all examined nutrients decreased as maturity advanced from first to third harvest date. Digestibility of OM, ADFom and NFC was significantly and digestibility of aNDFom was tendentially (p = 0.064) influenced by variety. Additionally, an effect of year and a harvest date × year interaction was found for almost all examined parameters. In conclusion, variety, harvest date and year influence the nutritive value of WCMS. A comparison with earlier studies shows that current varieties have a higher fibre digestibility and a slower-ripening stover compared to older varieties.     

Although there is no Physical Short‐Term Scarcity of Phosphorus,its Resource Efficiency Should be Improved

The German government has adopted a law that requires sewage plants to go beyond the recovery of phosphorus from wastewater and to promote recycling. We argue that there is no physical global short‐ or mid‐term phosphorus scarcity. However, we also argue that there are legitimate reasons for policies such as those of Germany, including: precaution as a way to ensure future generations’ long‐term supply security, promotion of technologies for closed‐loop economics in a promising stage of technology development, and decrease in the current supply risk with a new resource pool.     

江西省2010年柯萨奇病毒A组24型变异株的全基因组序列分析

急性出血性结膜炎(Acute hemorrhagic conjunctivitis,AHC)是目前人类最常见的眼病之一,柯萨奇病毒A组24型变异株(Coxsackievirus A24 variant,CV-A24v)是近年来报道引起该病的主要病原体。本研究选取10株来自江西省2010年AHC暴发疫情的CV-A24v,采用特异性引物扩增并测定其全基因组序列。对该10条CV-A24v的全基因组序列进行系统发育分析以及重组分析,计算本研究测定的江西10条以及GenBank中所有22条CV-A24v的全基因组序列的氨基酸置换熵值,并预测其正向选择位点。结果表明,在江西10条CV-A24v基因组序列中未检测到重组。基于全基因组序列构建的最大似然树表明江西10株CV-A24v属于GIV基因型,且分处于两条传播链。对上述32条CV-A24v序列的氨基酸置换熵值计算,共得到25个易突变位点(熵值>0.6),易突变概率最高的区段为2A区。基于Datamonkey中FUBAR和FEL模型分析,发现位于结构蛋白VP2区的234位氨基酸为两种模型共同获得的CV-A24v的正向选择位点。本研究分析了江西10株CV-A24v的全基因组序列特征,为CV-A24v引起的AHC防控工作提供了基础资料。     

Activities of the matrix metalloproteinase stromelysin-2 (MMP-10) in matrix degradation and keratinocyte organization in wounded skin

The matrix metalloproteinase stromelysin-2 is expressed in keratinocytes of the epithelial tongue of skin wounds, suggesting a role in keratinocyte migration. Here, we show that stromelysin-2 enhances migration of cultured keratinocytes. To gain insight into the in vivo activities of stromelysin-2 in epithelial repair, we generated transgenic mice expressing a constitutively active stromelysin-2 mutant in keratinocytes. These animals had no alterations in skin architecture, and the healing rate of skin wounds was normal. Histologically, however, we found abnormalities in the organization of the wound epithelium. Keratinocytes at the migrating epidermal tip were scattered in most sections of mice with high expression level, and there was a reduced deposition of new matrix. In particular, the staining pattern of laminin-5 at the wound site was altered. This may be due to proteolytic processing of laminin-5 by stromelysin-2, because degradation of laminin-5 by this enzyme was observed in vitro. The inappropriate matrix contact of keratinocytes was accompanied by aberrant localization of beta1-integrins and phosphorylated focal adhesion kinase, as well as by increased apoptosis of wound keratinocytes. These results suggest that a tightly regulated expression level of stromelysin-2 is required for limited matrix degradation at the wound site, thereby controlling keratinocyte migration.     

Binding characterization of the interleukin-13 signaling complex and development of a ternary time-resolved fluorescence resonance energy transfer assay

Interleukin-13 (IL-13) is a critical mediator of pulmonary pathology associated with asthma. Drugs that block the biological function of IL-13 may be an effective treatment for asthma. IL-13 signals by forming a ternary complex with IL-13Rα1 and IL-4R. Genetic variants of IL-13 and of its receptor components have been linked to asthma. One in particular, IL-13R110Q, is associated with increased IgE levels and asthma. We characterized the interactions of the binary complexes composed of IL-13 or IL-13R110Q with IL-13Rα1 and the ternary complexes composed of IL-13 or IL-13R110Q and IL-13Rα1 with IL-4R using surface plasmon resonance and time-resolved fluorescence resonance energy transfer (TR-FRET). By both biophysical methods, we found no differences between IL-13 and IL-13R110Q binding in either the binary or the ternary complex. IL-4R bound to the IL-13/IL-13Rα1 complex with slow on and off rates, resulting in a relatively weak affinity of about 100 nM. We developed a TR-FRET assay targeting the interaction between the IL-4R and the binary complex. Two antibodies with known binding epitopes to IL-13 that block binding to either IL-13Rα1 or IL-4R inhibited the TR-FRET signal formed by the ternary complex. This assay will be useful to identify and characterize inhibitory molecules of IL-13 function.     

Microtubule-associated protein 2 (MAP2)-immunoreactive neurons in the retina of Bufo marinus: colocalisation with tyrosine hydroxylase and serotonin in amacrine cells

Summary Neuron populations in the retina of the toad, Bufo marinus, were labelled with a monoclonal antibody raised against microtubule-associated protein 2 (MAP2). A subpopulation of cones, probably corresponding to the blue-sensitive small single cones, large diameter amacrine cells in the most proximal row of the inner nuclear layer and some large ganglion cells in the ganglion cell layer were labelled. Double labelling experiments were carried out to establish the colocalisation of MAP2 with known putative transmitter substances of the anuran amacrine cells. MAP2 was colocalised in a subpopulation of serotonin-immunoreactive and in all tyrosine hydroxylase-immunoreactive amacrine cells. The results indicate, that the MAP2 content in the neurons of the anuran retina can be correlated with other well-defined neurochemical and/or physiological properties.On leave from Department of Zoology, Attlia József University, Szeged, Hungary