Search results for "toxin"
showing 10 items of 1434 documents
Bioactive compounds from mustard flours for the control of patulin production in wheat tortillas
2016
Abstract Patulin (PAT) is a toxic fungal metabolite produced by Penicillium, Aspergillus and Byssochlamys growing especially in fruit and cereals. PAT exhibits a number of toxic effects in animals and its presence in food is undesirable. In this study the reduction of the mycotoxin PAT produced by a strain of Penicillium expansum, on wheat tortillas was studied using volatile bioactive compounds present in the oriental and yellow mustard flour and also using the standard solution of the antifungal compound allyl isothiocyanate (AIT), developing an active packaging with two different systems of release of those bioactive compounds. Also the kinetic of volatilization of the compounds used in …
Selection of distinct Valpha/beta T-cell receptor families during in vivo and in vitro T-cell maturation.
1999
The experimental conditions influencing the use of Valphabeta TCR families were examined in lymph node (LN) cells from peptide-immunized C57BL/6 and Vbeta8.2 transgenic mice. Expanded proportions of Vbeta5, Vbeta8.2, Vbeta9, Vbeta12 and Vbeta14 positive cells and an association of Vbeta8.2 with Valpha11 was found in freshly harvested 8-day or 34-day immune LN cells. In contrast, peptide-specific T-cell lines generated in vitro from 8-day immune lymph node cells were found to be almost exclusively of the Valpha2/Vbeta12 family. However, T-cell lines originating from Vbeta8.2 transgenic mice did not show preferential Valpha usage. Anti-Vbeta8.2 antibody produced different effects: when added …
Procalcitonin and long-term prognosis after an admission for acute heart failure
2014
Abstract Background Traditionally, procalcitonin (PCT) is considered a diagnostic marker of bacterial infections. However, slightly elevated levels of PCT have also been found in patients with heart failure. In this context, it has been suggested that PCT may serve as a proxy for underrecognized infection, endotoxemia, or heightened proinflammatory activity. Nevertheless, the clinical utility of PCT in this setting is scarce. We aimed to evaluate the association between PCT and the risk of long-term outcomes. Methods and results We measured at admission PCT of 261 consecutive patients admitted for acute heart failure (AHF) after excluding active infection. Cox and negative binomial regressi…
Cytotoxicity of medicinal plants of the West-Canadian Gwich׳in Native Americans towards sensitive and multidrug-resistant cancer cells
2015
Abstract Ethnopharmacological relevance Traditional medicine of the Native Americans has a long tradition of medicinal plants, which also influenced modern oncology. For instance, podophyllotoxin the active ingredient of Podophyllum peltatum L. (Berberidaceae) used by Native Americans to treat warts led to the development of etoposide and teniposide. In the present investigation, we studied 10 medicinal plants used by the Gwich׳in First Nation of West-Canada, which have been used against diverse diseases including cancer. Material and methods Sensitive and multidrug-resistant (MDR) tumor cell lines expressing various ATP-binding cassette (ABC) transporters (P-glycoprotein/ ABCB1/MDR1 , MRP1…
TP53 mutations and hepatocellular carcinoma: insights into the etiology and pathogenesis of liver cancer.
2007
Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and the major risk factors include chronic infections with the hepatitis B (HBV) or C (HCV) virus, and exposure to dietary aflatoxin B(1) (AFB(1)) or alcohol consumption. Multiple genetic and epigenetic changes are involved in the molecular pathogenesis of HCC, for example, somatic mutations in the p53 tumor suppressor gene (TP53) and the activation of the WNT signal transduction pathway. AFB(1) frequently induces G:C to T:A transversions at the third base in codon 249 of TP53 and cooperates with HBV in causing p53 mutations in HCC. The detection of TP53 mutant DNA in plasma is a biomarker of both AFB(1) exposur…
Holo-APP and G-protein-mediated signaling are required for sAPPa-induced activation of the Akt survival pathway
2014
International audience; Accumulating evidence indicates that loss of physiologic amyloid precursor protein (APP) function leads to reduced neuronal plasticity, diminished synaptic signaling and enhanced susceptibility of neurons to cellular stress during brain aging. Here we investigated the neuroprotective function of the soluble APP ectodomain sAPPa (soluble APPa), which is generated by cleavage of APP by a-secretase along the non-amyloidogenic pathway. Recombinant sAPPa protected primary hippocampal neurons and SH-SY5Y neuroblastoma cells from cell death induced by trophic factor deprivation. We show that this protective effect is abrogated in neurons from APP-knockout animals and APP-de…
Tetanus Toxin Inhibits Neuroexocytosis Even When Its Zn2+-dependent Protease Activity Is Removed
1995
Tetanus toxin (TeTX) is a dichain protein that blocks neuroexocytosis, an action attributed previously to Zn(2+)-dependent proteolysis of synaptobrevin (Sbr) by its light chain (LC). Herein, its cleavage of Sbr in rat cerebrocortical synaptosomes was shown to be minimized by captopril, an inhibitor of certain metalloendoproteases, whereas this agent only marginally antagonized the inhibition of noradrenaline release, implicating a second action of the toxin. This hypothesis was proven by preparing three mutants (H233A, E234A, H237A) of the LC lacking the ability to cleave Sbr and reconstituting them with native heavy chain. The resultant dichains were found to block synaptosomal transmitter…
Cytotoxic effects and degradation products of three mycotoxins: Alternariol, 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol in liver hepatocell…
2015
This work is focused in studying the cytotoxic effects on HepG2 cells of the mycotoxins alternariol (AOH), 3-acetyl-deoxynivalenol (3-ADON) and 15-acetyl-deoxynivalenol (15-ADON) by the MTT assay, as well as in the identification of the degradation products and/or metabolites originated after treatment by liquid chromatography tandem mass spectrometry (LC-MS/MS) equipment and extracted from culture media. HepG2 cells were treated at different concentrations over 24, 48 and 72 h. The IC50 values were from 65 to 96 μM, from 3.6 to 6.2 μM and from 5.2 to 8.1 μM for AOH, 3-ADON and 15-ADON, respectively. Among all three mycotoxins assayed, deoxynivalenol (DON) derivated presented the highest to…
Intracoronary application of C1 esterase inhibitor improves cardiac function and reduces myocardial necrosis in an experimental model of ischemia and…
1997
Background Myocardial injury from ischemia can be aggravated by reperfusion of the jeopardized area. The precise underlying mechanisms have not been clearly defined, but proinflammatory events, including complement activation, leukocyte adhesion, and infiltration and release of diverse mediators, probably play important roles. The present study addresses the possibility of reducing reperfusion damage by the application of C1 esterase inhibitor (C1-INH). Methods and Results Cardioprotection by C1-INH 20 IU/kg IC was examined in a pig model with 60 minutes of coronary occlusion, followed by 120 minutes of reperfusion. C1-INH was administered during the first 5 minutes of coronary reperfusion…
C1-esterase inhibitor in ischemia and reperfusion.
2002
Summary Myocardial injury from ischemia can be aggravated by reperfusion of the jeopardized area. The precise underlying mechanisms have not been clearly defined, but proinflammatory events including complement activation play important roles. Cardioprotection by complement inhibition inter alia C1-esterase-inhibitor (C1-INH) was examined in several experimental models and under clinical conditions with ischemia and reperfusion. C1-INH reduced local anaphylatoxin release revealing the importance of the classical complement pathway. Inhibition of local complement activation was accompanied by improvement of myocardial function and perfusion of the previously ischemic myocardium. Leukocyte en…