Wirkung von N-Trichlormethylthio-tetrahydrophthalimid auf Weinhefen

N-Trichlormethylthio-tetrahydrophthalimid (NTT) ist in mehreren käuflichen Fungiziden enthalten, die im Rebschutz verwendet werden. Diese Substanz ist infolge der Inaktivierung einiger glykolytischer Enzyme als wirksamer Inhibitor der Weinhefengärung anzusprechen. Versuchergebnisse mit Atmungs-Hefentypen weisen auch auf Eingriffe von NTT an verschiedenen Stellen der oxidativen Phosphorylierung hin. Die Inhibition dieses Vorganges sowie der Glykolyse beruht auf einer Abänderung der Proteine, die für ihre katalytische Aktivität Thiolgruppen benötigen. Als Folge mehrfacher Eingriffe von NTT in den energetischen Stoffwechsel der Hefen kommt es zur Hemmung biosynthetischer Prozesse und damit auch zur Einstellung des Zellwachstums. Hierauf deuten die Ergebnisse von Untersuchungen über die Aufnahme 14C-markierter Präkursoren der Protein- und Nukleinsäuresynthese hin. Es werden ferner Angaben mitgeteilt, die es ermöglichen, die Hemmwirkung verschiedener Fungizidpräparate des Handels gegenüber Hefen zu vergleichen. Die Bedeutung der Hefen als Modellorganismen zur Aufklärung des Wirkungsmechanismus fungitoxischer Substanzen wird unterstrichen.Effect of N-trichloromethylthio-tetrahydropbtbalimide on wine yeastsN-trichloromethylthio-tetrahydrophthalimide (NTT), an active component of many commercial fungicidal preparations used in viticulture, is a powerful in hibitor of yeast fermentation due to the inactivation of some glycolytic enzymes. In experiments especially with respiratory yeast types the results obtained show also interferences of NTT with the oxidative phosphorylation. The inhibition of this process and also of glycolysis is a result of modificaticn of proteins requiring thiol groups for their catalytic activity. As a consequence of the multitarget effect of NTT on yeast energy metabolism, biosynthetic processes are inhibited and, finally, yeast growth is blocked. These facts are indicated by the results obtained from study of NTT influence on incorporation of 14Clabelled precursors of both protein and nucleic acid biosynthesis. Data included in the paper make it also possible to compare the antiyeast activities of different types of commercial fungicides. The importaRce of yeasts as a model for the elucidation of the mode of action of antifungal substances is emphasized

Sulforaphane Potentiates RNA Damage Induced by Different Xenobiotics

Background: The isothiocyanate sulforaphane (SFN) possesses interesting anticancer activities. However, recent studies reported that SFN promotes the formation of reactive oxygen species (ROS) as well as DNA breakage. Methodology/Principal Findings: We investigated whether SFN is able to damage RNA, whose loss of integrity was demonstrated in different chronic diseases. Considering the ability of SFN to protect from genotoxicity, we also examined whether SFN is able to protect from RNA damage induced by different chemicals (doxorubicin, spermine, S-nitroso-Nacetylpenicillamine, H2O2). We observed that SFN was devoid of either RNA damaging and RNA protective activity in human leukemic cells. It was able to potentiate the RNA damage by doxorubicin and spermine. In the first case, the effect was attributable to its ability of modulating the bioreductive activation of doxorubicin. For spermine, the effects were mainly due to its modulation of ROS levels produced by spermine metabolism. As to the cytotoxic relevance of the RNA damage, we found that the treatment of cells with a mixture of spermine or doxorubicin plus SFN increased their proapoptotic potential. Thus it is conceivable that the presence of RNA damage might concur to the overall toxic response induced by a chemical agent in targeted cells. Conclusions/Significance: Since RNA is emerging as a potential target for anticancer drugs, its ability to enhance spermineand doxorubicin-induced RNA damage and cytotoxicity could represent an additional mechanism for the potentiatin

Endophytic fungi from the roots of horseradish (Armoracia rusticana) and their interactions with the defensive metabolites of the glucosinolate myrosinase – isothiocyanate system

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The analysis of waves dispersive propagation in mechanical transducers of impulsive force and pressure sensors

Przedstawiono doświadczalną metodę wyznaczenia charakterystyki dyspersyjnej przetwornika mechanicznego stosowanego w pomiarach impulsowych wymuszeń mechanicznych. Metoda bazuje na analizie czasowo częstotliwościowej sygnału wyjściowego czujnika pomiarowego. Do analizy wykorzystano ciągłe przekształcenie falkowe z funkcją okna Gabora. Dla zobrazowania metody, zastosowano ją do wyznaczenia charakterystyki dyspersyjnej przetwornika mechanicznego przy wymuszeniu w postaci mechanicznego uderzenia stalowej kulki.This work presents an experimental method of determining the dispersive characteristic of the mechanical transducer using in impulsive force and pressure measurements. The method is based on continuous wavelet transform with the Gabor analyzing function applied to the output signal of the sensor. An experimental verification of the method is presented