Expression of claudin‐5 in hepatoid gland biopsies

Claudins are integral membrane proteins involved in the structure of the tight junctions found in epithelial and endothelial cells. This study evaluated the expression of claudin‐5 in 67 hyperplastic and neoplastic lesions of canine hepatoid glands. These included normal hepatoid glands (n = 10), nodular hyperplasia (n = 10), adenomas (n = 12), epitheliomas (n = 15), differentiated carcinomas (n = 15) and anaplastic carcinomas (n = 15). There was intense lateral membrane expression of claudin‐5 on epithelial cells from normal hepatoid glands, nodular hyperplasia and adenomas, but expression was weaker in hepatoid gland epitheliomas. Basal reserve cells from normal glands, nodular hyperplasia, adenomas and epitheliomas never expressed claudin‐5. There was membrane‐bound immunoreactivity for claudin‐5 in selected areas of the epitheliomas where the cells exhibited typical hepatoid features. The weak expression of claudin‐5 molecule in epitheliomas may nevertheless lead to cellular disorientation, detachment and invasion. Claudin‐5 expression seemed to be helpful in distinguishing poorly differentiated carcinomas, differentiated carcinomas and epitheliomas of the hepatoid glands. Increased claudin‐5 expression by invasive anaplastic carcinomas may facilitate invasion and metastasis through the activation of matrix metalloproteinases.     

Composition and end-use quality of 150 wheat lines selected for the HEALTHGRAIN Diversity Screen

The HEALTHGRAIN program is focused on developing new healthy food products based on wholegrains of wheat and other cereals, by combining enhanced nutritional quality with good agronomic performance and processing quality. A sample set comprising 130 winter and 20 spring wheat varieties was therefore selected to identify the range of variation in a number of phytochemical and dietary fiber components. These lines were also analyzed for their technological properties (protein and gluten contents, Zeleny sedimentation, bran yield, kernel hardness, etc.), using samples grown on adjacent sites for two successive seasons (2004-2005, 2005-2006). On the basis of the frequency distribution and principal component analysis it was concluded that significant variation for technological quality traits is present in the 150 wheat lines and that it is possible to combine enhanced nutritional quality with good agronomic performance and processing properties.     

Molecular cytogenetic characterization and SSR marker analysis of a leaf rust resistant wheat line carrying a 6G(6B) substitution from <Emphasis Type="Italic">Triticum timopheevii</Emphasis> (Zhuk.)

A disease (powdery mildew, leaf rust) resistant line was selected from the progenies of a Triticum aestivum × Triticum timopheevii amphiploid produced at Martonvásár. This line was previously identified with C-banding as a 6G(6B) substitution. In order to detect the 6G chromosome in a wheat background, fluorescence in situ hybridization (FISH) and microsatellite marker analysis were used. Ten microsatellite markers of the 43 tested generated PCR products that were polymorphic between chromosomes 6B and 6G, and four showed length-polymorphism. The FISH hybridization pattern of 6G from T. timopheevii was identified using a combination of four repetitive DNA probes (Afa-family, pSc119.2, pTa71, (GAA)₇). Genomic in situ hybridization (GISH) technique, capable of labelling the A^t and G genomes separately, was used on the same slides to differentiate the A^t and G genomes in T. timopheevii. The A^t and G genomes of T. timopheevii were grouped on the basis of the GISH patterns and a cyclic intergenomic translocation involving 6A^t-1G-4G was detected in T. timopheevii accession TRI667. The presence of 6G in the substitution line was demonstrated using FISH with the four repetitive DNA probes. Chromosome 6G was clearly identified and its FISH pattern was different from that of 6B in the parental wheat cultivar Fleischmann-481. According to field tests, the 6G(6B) substitution line has resistance to leaf rust.     

Shrub Encroachment Under the Trees Diversifies the Herb Layer in a Romanian Silvopastoral System

Rangelands with scattered trees are complex and dynamic systems with a long history in Europe. Generally referred to as “wood-pastures,” they are considered to have outstanding conservation value. Thorny shrubs are important for supporting the biodiversity of these wooded rangelands, as well as facilitating the regeneration of trees by acting as nurse species. We assess the direct effects of temporary shrub encroachment under the cover of mature sparse trees on overall plant and habitat diversity. We surveyed the herb layer of the main landscape features of a wood-pasture: open pasture, trees with a grass understory, trees with shrubs, and adjacent forest edges. The herb layer under trees with shrubs resembled that of forest edges more than open pastures and trees with grass. Trees with grass had a higher cover of ruderal species than trees with shrubs, while forest edges and open pastures had a lower cover of them. Forest species were absent from open pastures but were well represented in the other sites. The herb layer of trees with shrubs and forest edges had similar cover values, while trees with grass had a significantly lower cover of herbs than the other types. Trees with shrubs had higher species richness than any of the other three landscape features and had a much higher proportion of diagnostic species. We conclude that the scattered trees and shrubs of the studied silvopastoral system have additive facilitative effects on their understory, probably through modifying the microenvironment and grazing pressure, leading to the formation of temporary diversity hot spots with distinct vegetation. Thus maintaining a moderate level of shrub-encroachment under sparse trees is recommended for not only creating safe havens for tree recruitment but also increasing the overall species and habitat diversity of wood-pastures.     

Detection and molecular analysis of West Nile virus infections in birds of prey in the eastern part of Austria in 2008 and 2009

The emergence of West Nile virus (WNV) was expected in Austria since the initial discovery of the infection in neighbouring Hungary in 2003/2004. In 2008 six cases of West Nile disease were diagnosed at the Institute for Veterinary Disease Control M?dling, Austrian Agency for Health and Food Safety (AGES), involving five goshawks (Accipiter gentilis) and one gyrfalcon (Falco rusticolus), which were found dead in the eastern Austrian federal states of Lower Austria, Vienna and Styria, respectively. Pathomorphological and immunohistochemical findings suggested a WNV infection. Virus was isolated in embryonated specific pathogen free chicken eggs and propagated in mouse neuroblastoma cells (NA), in which a cytopathic effect occurred. The virus was identified and characterised by electron microscopic examination and molecular detection using RT-PCR, sequencing, and phylogenetic analysis. The Austrian WNV sequences exhibited nucleotide identities of 99.9% to the lineage 2 WNV sequences described in Hungary since 2004. In addition, 71 sera of 14 different bird species were screened for the presence of WNV antibodies using a commercial ELISA: 43.7% of the tested samples showed antibody titers. Selected positive sera were also subjected to WNV neutralisation tests, in which the ELISA results were verified in 66%. The results of this study confirm unambiguously the presence of a lineage 2 WNV infection in birds of prey in the eastern part of Austria.     

Role of reactive oxygen species and antioxidants in plant disease resistance

Membrane damage caused by the non-specific fungal toxin fusaric acid was less on pretreated than on control leaves when tobacco leaves were pretreated with anti-senescence plant hormones, such as kinetin, benzyladenine or the anti-ozonant N-[2-(2-oxo-1-imidazolidinyl)]ethyl-N'-phenylurea. Similarly, the necrosis caused by mercuric chloride was reduced by the above anti-senescence agents. In addition, in in vitro tests, leaves from selected paraquat-tolerant tobacco plants were less sensitive to Alternaria alternata (Fr) Keissler infection than those of the control paraquat-sensitive tobacco leaves. Paraquat-tolerant Conyza canadensis (L) Cronq weeds naturally selected in vineyards in Hungary showed similar inhibition of senescence to paraquat-tolerant tobacco, expressed as more green leaves and slower development. In accordance with this, the paraquat-tolerant Conyza leaves remained almost symptomless, while paraquat-sensitive plants showed severe symptoms after infection with Botrytis cinerea Pers. Oxidative burst (accumulation of hydrogen peroxide) was attenuated in TMV-infected leaves of Xanthi-nc tobacco as a result of treatment with salicylic acid or in leaves where systemic acquired resistance (SAR) had been induced by a previous TMV infection. Accordingly, superoxide dismutase (SOD) activity was higher in Xanthi tobacco leaves with SAR than without SAR. However, in NahG tobacco, in which SAR cannot develop, there was no augmentation of SOD activity. All the above data support the significance of delayed senescence and antioxidants in the resistance of plants to biotic and abiotic necrosis-inducing agents.     

Influence of winemaking practices on the concentration of rare earth elements in white wines studied by inductively coupled plasma mass spectrometry

Influence of clarification, filtration, and storage on the concentration of rare earth elements (REEs) was studied in white wines by inductively coupled plasma mass spectrometry (ICP-MS). Smooth and parallel chondrite-normalized (CN) plots were obtained for wines which have never been in contact with fining agents. Clarification and filtration generally used in white wine production were simulated in the laboratory using nontreated reference wines, and CN plots were compared before and after treatments. Clarification by bentonites yields an overall increase in REE concentrations resulting in substantially parallel CN curves well above the plots of the corresponding nontreated wines. Filtration using silicate (SiO2), on the other hand, changes the CN profile in a nonparallel manner due to a higher release of La, Ce, Pr, Nd, and Gd, more than other elements studied. Filtration with cellulose powder causes a small increase in the concentration of light REEs, while the concentrations of other elements remain basically unchanged. Storage conditions could also affect the REE pattern of wine. We found that the influence of glass is greater than that of stainless steel and wood. In addition, we report that commercially available finished white wines from the same region show highly different REE patterns depending on the winemaking practices employed.     

Up-regulation of antioxidants in tobacco by low concentrations of H₂O₂ suppresses necrotic disease symptoms

Pretreatment of tobacco leaves with low concentrations (5 to 10 mM) of H?O? suppressed hypersensitive-type necrosis associated with resistance to Tobacco mosaic virus (TMV) or Pseudomonas syringae pv. phaseolicola. The same pretreatment resulted in suppression of normosensitive necrosis associated with susceptibility to Botrytis cinerea. This type of H?O?-mediated, induced disease symptom resistance correlated with enhanced host antioxidant capacity, i.e., elevated enzymatic activities of catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (POX) after viral and bacterial infections. Induction of genes that encode the antioxidants superoxide dismutase (SOD), CAT, and APX was also enhanced early after TMV infection. Artificial application of SOD and CAT suppressed necroses caused by viral, bacterial, or fungal pathogens similarly as H?O? pretreatment, implying that H?O?-mediated symptom resistance operates through enhancement of plant antioxidant capacity. Pathogen multiplication was not significantly affected in H?O?-pretreated plants. Salicylic acid (SA), a central component of plant defense, does not seem to function in this type of H?O?-mediated symptom resistance, indicated by unchanged levels of free and bound SA and a lack of early up-regulation of an SA glucosyltransferase gene in TMV-infected H?O?-pretreated tobacco. Taken together, H?O?-mediated, induced resistance to necrotic symptoms in tobacco seems to depend on enhanced antioxidant capacity.     

No indication of strict host associations in a widespread mycoparasite: grapevine powdery mildew (Erysiphe necator) is attacked by phylogenetically distant Ampelomyces strains in the field

Pycnidial fungi belonging to the genus Ampelomyces are common intracellular mycoparasites of powdery mildews worldwide. Some strains have already been developed as commercial biocontrol agents (BCAs) of Erysiphe necator and other powdery mildew species infecting important crops. One of the basic, and still debated, questions concerning the tritrophic relationships between host plants, powdery mildew fungi, and Ampelomyces mycoparasites is whether Ampelomyces strains isolated from certain species of the Erysiphales are narrowly specialized to their original mycohosts or are generalist mycoparasites of many powdery mildew fungi. This is also important for the use of Ampelomyces strains as BCAs. To understand this relationship, the nuclear ribosomal DNA internal transcribed spacer (ITS) and partial actin gene (act1) sequences of 55 Ampelomyces strains from E. necator were analyzed together with those of 47 strains isolated from other powdery mildew species. These phylogenetic analyses distinguished five major clades and strains from E. necator that were present in all but one clade. This work was supplemented with the selection of nine inter-simple sequence repeat (ISSR) markers for strain-specific identification of Ampelomyces mycoparasites to monitor the environmental fate of strains applied as BCAs. The genetic distances among strains calculated based on ISSR patterns have also highlighted the genetic diversity of Ampelomyces mycoparasites naturally occurring in grapevine powdery mildew. Overall, this work showed that Ampelomyces strains isolated from E. necator are genetically diverse and there is no indication of strict mycohost associations in these strains. However, these results cannot rule out a certain degree of quantitative association between at least some of the Ampelomyces lineages identified in this work and their original mycohosts.     

A review of physiological and biochemical aspects of resistance to atrazine and paraquat in Hungarian weeds

The most important results in the field of atrazine and paraquat resistance research by Hungarian researchers are reviewed. Pleiotropic effects accompanying atrazine resistance were investigated in atrazine-resistant (AR) and susceptible (S) biotypes of horseweed (Conyza canadensis (L) Cronq). No significant difference in carbon dioxide assimilation rate was found between the AR and S plants. The rates of the Hill reaction of the AR and S chloroplasts exhibited different temperature dependence. The thylakoid membrane lipids contained a lower amount of polar lipid and the fatty acid content exhibited a higher degree of unsaturation in the AR biotype. Photosynthetic apparatus of the AR biotype had better adaptive ability at low temperature and showed enhanced susceptibility to high-temperature stress. AR horseweed plants had reduced activity of xanthophyll cycle, limited capacity of light-induced non-photochemical and photochemical quenching, higher photosensitivity and susceptibility to photo-inhibition. In the case of paraquat resistance, horseweed found in Hungary exhibited a resistance factor of 450; the resistance is not based on an elevated level and activity of the antioxidant enzyme system. The suggested role of polyamines in the resistance mechanisms can be excluded. The higher putrescine and total polyamine content of paraquat-treated R leaves can be regarded as a general stress response rather than as a symptom of paraquat resistance. A paraquat-inducible, nuclear-coded protein, which presumably functions by carrying paraquat to the vacuole, is supposed to play a role in resistance.