Search results for "toxin"
showing 10 items of 1434 documents
Influence of prebiotics, probiotics and protein ingredients on mycotoxin bioaccessibility
2015
The aim of this study was to investigate the influence of prebiotic compounds (cellulose and inulin), food ingredients (milk whey, β-lactoglobulin and calcium caseinate) and several probiotic microorganisms on the bioaccessibility of beauvericin (BEA), enniatins (ENs A, A1, B, B1), deoxynivalenol (DON) and zearalenone (ZEA) present in wheat crispy bread produced with wheat flour previously fermented with F. tricinctum, F. culmorum and G. zeae. The bioaccessibility of mycotoxins was determined by a dynamic simulated gastrointestinal digestion system, imitating the human digestive physiological conditions of the gastrointestinal tract. Mycotoxins were determined in the simulated intestinal fl…
Early steps in the European eel (Anguilla anguilla)–Vibrio vulnificus interaction in the gills: Role of the RtxA13 toxin
2015
Vibrio vulnificus is an aquatic gram-negative bacterium that causes a systemic disease in eels called warm-water vibriosis. Natural disease occurs via water born infection; bacteria attach to the gills (the main portal of entry) and spread to the internal organs through the bloodstream, provoking host death by haemorrhagic septicaemia. V.vulnificus produces a toxin called RtxA13 that hypothetically interferes with the eel immune system facilitating bacterial invasion and subsequent death by septic shock. The aim of this work was to study the early steps of warm-water vibriosis by analysing the expression of three marker mRNA transcripts related to pathogen recognition (tlr2 and tlr5) and in…
Melatonin modulates diacylglycerol and arachidonic acid metabolism in the anterior pituitary of immature rats.
1990
In pituitary glands of immature rats prelabeled in vitro with [3H]arachidonic acid, melatonin diminished the luteinizing hormone-releasing hormone (LHRH)-induced increase in [3H]diacylglycerol accumulation as well as [3H]arachidonic acid release from the tissue. Melatonin reduced also LHRH-stimulated incorporation of [3H]glycerol into pituitary [3H]diacylglycerol. The effect was day-time dependent: in the evening experiment melatonin was effective at 0.1 nM concentration while in the morning it had no effect even at 10 nM concentration. The effect of melatonin was also abolished by pretreatment with pertussis toxin. Diacylglycerol and/or arachidonic acid might serve as 2nd messengers transd…
Genetic rearrangements in the pathogenicity locus of Clostridium difficile strain 8864 – implications for transcription, expression and enzymatic act…
1998
The pathogenicity locus (PaLoc) of Clostridium difficile isolate 8864 was investigated to locate genetic rearrangements that would explain the exceptional pathogenicity of this particular isolate. Two major changes were defined: an insertion of 1.1 kb between the two genes tcdA and tcdE, coding for the enterotoxin and an accessory protein of unknown function, respectively, and a deletion of 5.9 kb encompassing the 3' ends of tcdA and tcdC. Transcription of the tcdA-E genes is severely affected by both rearrangements, explaining the demonstrated complete lack of TcdA polypeptide. We present a model of coordinate, growth-related transcription of the tcdA-E genes that confirms our previous fin…
A novel cytotoxin from Clostridium difficile serogroup F is a functional hybrid between two other large clostridial cytotoxins.
1999
Abstract The large clostridial cytotoxins (LCTs) constitute a group of high molecular weight clostridial cytotoxins that inactivate cellular small GTP-binding proteins. We demonstrate that a novel LCT (TcdB-1470) from Clostridium difficile strain 1470 is a functional hybrid between “reference” TcdB-10463 andClostridium sordellii TcsL-1522. It bound to the same specific receptor as TcdB-10463 but glucosylated the same GTP-binding proteins as TcsL-1522. All three toxins had equal enzymatic potencies but were equally cytotoxic only when microinjected. When applied extracellularly TcdB-1470 and TcdB-10463 were considerably more potent cytotoxins than TcsL-1522. The small GTP-binding protein R-R…
Immunochemical analysis of the carbohydrate moiety of yeast killer toxin K28
1990
Killer toxin K28, a 16 kd protein secreted by the wine yeast Saccharomyces cerevisiae strain 28, was reversibly bound by a column of Concanavalin A-Sepharose, confirming its glycoprotein nature. HPLC analysis of acid hydrolyzates of K28 toxin as well as Western-blots of beta-eliminated and/or endo H-treated killer toxin preparations probed with polyclonal alpha-toxin antibodies revealed that the carbohydrate moiety of K28 consists of D-mannose only, which is O-glycosidically linked via Ser/Thr residues to the protein part. The change in gel mobility of K28 after beta-elimination was caused by a decrease in molecular mass of about 1,800, corresponding to a carbohydrate moiety of 10 mannose r…
Killer toxin of Hanseniaspora uvarum
1990
The yeast Hanseniaspora uvarum liberates a killer toxin lethal to sensitive strains of the species Saccharomyces cerevisiae. Secretion of this killer toxin was inhibited by tunicamycin, an inhibitor of N-glycosylation, although the mature killer protein did not show any detectable carbohydrate structures. Culture supernatants of the killer strain were concentrated by ultrafiltration and the extracellular killer toxin was precipitated with ethanol and purified by ion exchange chromatography. SDS-PAGE of the electrophoretically homogenous killer protein indicated an apparent molecular mass of 18,000. Additional investigations of the primary toxin binding sites within the cell wall of sensitiv…
Development of a green fluorescent tagged strain of Aspergillus carbonarius to monitor fungal colonization in grapes.
2011
An enhanced green fluorescent protein has been used to tag an OTA-producing strain of Aspergillus carbonarius (W04-40) isolated from naturally infected grape berries. Transformation of the fungus was mediated by Agrobacterium tumefaciens. The most efficient transformation occurred when the co-cultivation was done with 104 conidia due to higher frequency of resistance colonies (894 per 104 conidia) and lower background obtained. To confirm the presence of the hph gene in hygromycin resistant colonies, 20 putative transformants were screened by PCR analysis. The hph gene was identified in all the transformants. Variation on the expression levels of the eGFP was detected among the transformant…
Vergleich der subcellulären Verteilung von 3H-Strophanthin und 3H-Digi-toxin im Meerschweinchenherzen / Comparison of the Subcellular Distribution of…
1969
Um Aufschlus uber den Wirkort von Herzglykosiden in der Herzmuskelzelle zu erhalten, wurde die subcellulare Verteilung von 3H-Digitoxin und 3H-Strophanthin untersucht und mit dem positiv inotropen Effekt verglichen. Meerschweinchenherzen wurden nach der Langendorff-Methode mit glykosidhaltiger Tyrodelosung (3 · 10−7 bzw. 2,8 · 10−7 g/ml; 37°C) perfundiert; die Kontraktionskraft wurde fortlaufend isotonisch registriert. Die Glykosidkonzentration in den einzelnen Fraktionen wurde nach Homogenisation, Differentialzentrifugation und Extraktion der Glykoside mit Toluol bzw. Dioxan mit einem Flussigkeitsszintillations-zahlgerat bestimmt. Die Ruckverteilung wahrend der Aufarbeitung wurde in Kontro…