23 research outputs found

    Untersuchungen zum Gegenspielerkomplex von Lymantria dispar während einer Massenvermehrung auf einer bekannten Gradationsfläche

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    We have been surveying a gypsy moth, Lymantria dispar (Lep., Lymantriidae), population in the oak forest of Klingenbach near Eisenstadt, Austria, since 1992. During the last gradation from 1993 to 1996, we studied the natural enemy complex at this site in comparison with other locations where no outbreak occurred (HOCH et al. 2001). During the latency years, an experimental study on the impact of predators on L. dispar pupal populations was performed (GSCHWANTNER et al. 2002). The population density was recorded regularly; in the winter 2001/02, the egg mass surveys indicated a rising population after seven years of latency. We used this opportunity to study the parasitoid complex in the progradation phase. This phase of gypsy moth population dynamics was not studied in our previous work. Moreover, it allowed us to repeat the investigation during the outbreak after 11 years.Seit 1992 führen wir in einem Eichenmischwald bei Klingenbach, nahe Eisenstadt, Österreich, Abundanzerhebungen des Schwammspinners, Lymantria dispar (Lep., Lymantriidae) mittels Eigelegezählungen durch. Im Jahre 2002 zeichnete sich nach sieben Jahren der Latenz ein Anstieg der Populationsdischte ab. Die Zahl von 1,2 Gelegen/Baum im Winter 2002/03 deutete auf eine beginnende Massenvermehrung. Die Dichte an Eigelegen war im folgenden Winterhalbjahr mit 9,7 pro Baum extrem hoch. Durch stadienspezifische Aufsammlungen von L. dispar Raupen oder Puppen und deren Zucht im Labor ermittelten wir die durch Parasitoide verursachte Mortalität sowohl im Progradationsjahr 2003 als auch im Jahr der Kulmination 2004. Generell war die Mortalität der Raupen und Puppen sehr gering. Im Jahr der Progradation vermochte einzig Parasetigena silvestris (Dipt., Tachinidae) nennenswerte Mortalität von 23,7% bei Altraupen zu verursachen. Die sehr warme, trockene Witterung im Mai-Juni 2003 bedingte eine ausgesprochen schnelle Raupenentwicklung. Im Frühjahr 2004 zeigten die Raupenaufsammlungen noch geringere Parasitierungsraten. Es dominierten P. silvestris und Blepharipa sp. (Dipt., Tachinidae) mit 8,5% bzw. 8,0% bei den Altraupen. Aufsammlungen von Puppen im Jahr 2004 zeigten anhand der ypischen Fraßbilder eine Mortalität durch Calosoma spp. (Col., Carabidae) von 13% an den Zweigen des Baumbestandes bis 38% in der Strauchschicht. Die Ergebnisse unserer Untersuchung zum Antagonistenkomplex in der Phase der Progradation und Kulmination werden im Vergleich mit entsprechenden Daten aus der letzten Gradation 1993 diskutiert

    A Peptide Derived from the Highly Conserved Protein GAPDH Is Involved in Tissue Protection by Different Antifungal Strategies and Epithelial Immunomodulation

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    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has an important role not only in glycolysis but also in nonmetabolic processes, including transcription activation and apoptosis. We report the isolation of a human GAPDH (hGAPDH) (2-32) fragment peptide from human placental tissue exhibiting antimicrobial activity. The peptide was internalized by cells of the pathogenic yeast Candida albicans and initiated a rapid apoptotic mechanism, leading to killing of the fungus. Killing was dose-dependent, with 10μgml (3.1μM) and 100μgml hGAPDH (2-32) depolarizing 45% and 90% of the fungal cells in a population, respectively. Experimental C. albicans infection induced epithelial hGAPDH (2-32) expression. Addition of the peptide significantly reduced the tissue damage as compared with untreated experimental infection. Secreted aspartic proteinase (Sap) activity of C. albicans was inhibited by the fragment at higher concentrations, with a median effective dose of 160mgl−1 (50μM) for Sap1p and 200mgl−1 (63μM) for Sap2p, whereas Sap3 was not inhibited at all. Interestingly, hGAPDH (2-32) induced significant epithelial IL-8 and GM-CSF secretion and stimulated Toll-like receptor 4 expression at low concentrations independently of the presence of C. albicans, without any toxic mucosal effects. In the future, the combination of different antifungal strategies, e.g., a conventional fungicidal with immunomodulatory effects and the inhibition of fungal virulence factors, might be a promising treatment option

    The rice immune receptor XA21 recognizes a tyrosine-sulfated protein from a Gram-negative bacterium

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    Surveillance of the extracellular environment by immune receptors is of central importance to eukaryotic survival. The rice receptor kinase XA21, which confers robust resistance to most strains of the Gram-negative bacterium Xanthomonas oryzae pv. oryzae (Xoo), is representative of a large class of cell surface immune receptors in plants and animals. We report the identification of a previously undescribed Xoo protein, called RaxX, which is required for activation of XA21-mediated immunity. Xoo strains that lack RaxX, or carry mutations in the single RaxX tyrosine residue (Y41), are able to evade XA21-mediated immunity. Y41 of RaxX is sulfated by the prokaryotic tyrosine sulfotransferase RaxST. Sulfated, but not nonsulfated, RaxX triggers hallmarks of the plant immune response in an XA21-dependent manner. A sulfated, 21–amino acid synthetic RaxX peptide (RaxX21-sY) is sufficient for this activity. Xoo field isolates that overcome XA21-mediated immunity encode an alternate raxX allele, suggesting that coevolutionary interactions between host and pathogen contribute to RaxX diversification. RaxX is highly conserved in many plant pathogenic Xanthomonas species. The new insights gained from the discovery and characterization of the sulfated protein, RaxX, can be applied to the development of resistant crop varieties and therapeutic reagents that have the potential to block microbial infection of both plants and animals

    The rice immune receptor XA21 recognizes a tyrosine-sulfated protein from a Gram-negative bacterium.

    No full text
    Surveillance of the extracellular environment by immune receptors is of central importance to eukaryotic survival. The rice receptor kinase XA21, which confers robust resistance to most strains of the Gram-negative bacterium Xanthomonas oryzae pv. oryzae (Xoo), is representative of a large class of cell surface immune receptors in plants and animals. We report the identification of a previously undescribed Xoo protein, called RaxX, which is required for activation of XA21-mediated immunity. Xoo strains that lack RaxX, or carry mutations in the single RaxX tyrosine residue (Y41), are able to evade XA21-mediated immunity. Y41 of RaxX is sulfated by the prokaryotic tyrosine sulfotransferase RaxST. Sulfated, but not nonsulfated, RaxX triggers hallmarks of the plant immune response in an XA21-dependent manner. A sulfated, 21-amino acid synthetic RaxX peptide (RaxX21-sY) is sufficient for this activity. Xoo field isolates that overcome XA21-mediated immunity encode an alternate raxX allele, suggesting that coevolutionary interactions between host and pathogen contribute to RaxX diversification. RaxX is highly conserved in many plant pathogenic Xanthomonas species. The new insights gained from the discovery and characterization of the sulfated protein, RaxX, can be applied to the development of resistant crop varieties and therapeutic reagents that have the potential to block microbial infection of both plants and animals

    Impact of Intraprocedural Mitral Regurgitation and Gradient Following Transcatheter Edge-to-Edge Repair for Primary Mitral Regurgitation

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    BACKGROUND The impact of intraprocedural results following transcatheter edge-to-edge repair (TEER) in primary mitral regurgitation (MR) is controversial. OBJECTIVES This study sought to investigate the prognostic impact of intraprocedural residual mitral regurgitation (rMR) and mean mitral valve gradient (MPG) in patients with primary MR undergoing TEER. METHODS The PRIME-MR (Outcomes of Patients Treated With Mitral Transcatheter Edge-to-Edge Repair for Primary Mitral Regurgitation) registry included consecutive patients with primary MR undergoing TEER from 2008 to 2022 at 27 international sites. Clinical outcomes were assessed according to intraprocedural rMR and mean MPG. Patients were categorized according to rMR (optimal result: = 2+) and MPG (low gradient: 5 mm Hg). The prognostic impact of rMR and MPG was evaluated in a Cox regression analysis. The primary endpoint was 2-year all-cause mortality or heart failure hospitalization. RESULTS Intraprocedural rMR and mean MPG were available in 1,509 patients (median age = 82 years [Q1-Q3: 76.086.0 years], 55.1% male). Kaplan-Meier analysis according to rMR severity showed signi ficant differences for the primary endpoint between rMR = 3+ (58.0%; P = 2+ was independently linked to the primary endpoint (HR: 1.87; 95% CI: 1.32-2.65; P 5 mm Hg was not (HR: 0.78; 95% CI: 0.47-1.31; P = 0.35). CONCLUSIONS Intraprocedural rMR but not MPG independently predicted clinical outcomes following TEER for primary MR. When performing TEER in primary MR, optimal MR reduction seems to outweigh the impact of high transvalvular gradients. (JACC Cardiovasc Interv 2024;17:1559 -1573) (c) 2024 by the American College of Cardiology Foundation
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