Manganese Enhances Prion Protein Survival in Model Soils and Increases Prion Infectivity to Cells

Prion diseases are considered to be transmissible. The existence of sporadic forms of prion diseases such as scrapie implies an environmental source for the infectious agent. This would suggest that under certain conditions the prion protein, the accepted agent of transmission, can survive in the environment. We have developed a novel technique to extract the prion protein from soil matrices. Previous studies have suggested that environmental manganese is a possible risk factor for prion diseases. We have shown that exposure to manganese is a soil matrix causes a dramatic increase in prion protein survival (∼10 fold) over a two year period. We have also shown that manganese increases infectivity of mouse passaged scrapie to culture cells by 2 logs. These results clearly verify that manganese is a risk factor for both the survival of the infectious agent in the environment and its transmissibility

Field-based supercritical fluid extraction and immunoassay method for determination of organic contaminants

The contamination of soils, particularly by organic pollutants at industrial sites, has required the development of accurate methods of analysis to determine the nature and concentration of the pollutants, thereby allowing appropriate risk assessments and remedial strategies to be implemented. Conventional methods for site assessment generally entail extensive sampling across the whole site, with subsequent sample despatch to a centralised laboratory, where complex, solvent intensive procedures, such as Soxhlet extraction and GC-MS analyses are performed. Since such processes are laborious, expensive, and time-consuming, there has been an increasing demand for rapid and reliable field-based analytical methods for the low-cost and efficient extraction and analysis of organic pollutants from contaminated sites. This thesis describes the development of a field-compatible supercritical fluid extraction (SFE) device and method for extraction of organic contaminants from soil. SFE was chosen due to its reported high extraction efficiency, selectivity and environmentally friendly nature due to the usage of supercritical fluids as opposed to liquid solvents. A compact 72(W)xS7(D)xSO(H) cm, easily-transportable and user-friendly device was developed, based on the use of a reciprocating pump and back pressure regulator system. The optimised method yielded an average extraction recovery of 80% for total polycyclic aromatic hydrocarbons (PABs) when compared to the well-validated laboratory-based Soxhlet extraction method. Tests were performed on a range of natural samples with varying water content (0- 32% w/w) without any sample pre-treatment. In comparison, the only commercially available competing field method, based on solvent shake extraction, yielded recovery values of 20-70% coupled with poor precision. The thesis then describes the optimisation of a field applicable method for analysis of the SFE extracts, based on enzyme linked immunosorbent assays (ELISAs), a method offering speed, low cost and low solvent consumption. Available as a test kit, it was readily amenable to on-site usage requiring only simple equipment. Assay optimisation using an EPA sanctioned P AH immunoassay test kit demonstrated that the kit could function in methanolic SFE extracts diluted in buffer, hence allowing the direct analysis of total P ABs in SFE extracts with minimum sample preparation. Cross-reactivity from parent compounds was found to be an issue for the generation of quantitative data. Nevertheless, the method served as a reliable semi-quantitative technique for rapid screening of P AH levels in the SFE extracts of natural samples obtained from field-based tests. Poor performance of the solvent-shake extraction method linked to immunoassay further vindicated usage of the newly developed field-based SFEI immunoassay method. The thesis concludes by reporting on the successful field-based trials of the coupled SFE/immunoassay method. The SFE system shows promise as a valid tool for the rapid and efficient on-site monitoring of organic contaminants in soil matrices, providing an innovative and alternative approach to the commonly deployed solvent shake extraction method. The combined field-based SFElimmunoassay method is of benefit for the rapid low cost assessment of site contamination, allowing site owners and consultants alike to make rapid and informed decisions regarding site characterisation, monitoring and remediation without recourse to expensive and time consuming laboratory analyses

Removal of biogenic amines from wines by chemisorption on functionalized silica and effects on other wine components

The effectiveness of several functionalized silica materials (cation-exchange materials) for the removal of biogenic amines from wines, and the effects on other wine components and organoleptic characteristics were evaluated. Results have shown that mesoporous silica material bi-functionalized with phosphonic and sulfonic acids allowed the removal of histamine, putrescine, cadaverine, spermine and spermidine from wines, although the dose must be adapted for each wine according to the removal requirements and wine characteristics. A plus of the adsorbent developed is that it can be recovered and re-used for at least 3 treatments. Immediately following the treatments, a decrease in the levels of linear ethyl esters (ethyl hexanoate, ethyl octanoate and ethyl decanoate) was observed, although these levels were re-equilibrated after several days reducing this undesired side effect. A slight, but perceptible, effect on wine color was observed, probably due to the slight decrease in the pH of the wine produced by the treatments. On the basis of the sensory analysis that focused only on the aroma of the wines, the proposed technique would be more adequate for wines aged in barrels than for young winesDepto. de Química AnalíticaFac. de Ciencias QuímicasTRUEpu

Ethanol effect on yeast strains isolated from tchapalo, a traditional sorghum beer from Côte d'Ivoire

The general trend in sorghum beer production is now the use of starter culture to alleviate the problems of variations in organoleptic quality and microbiological stability. In this study, we aimed to select strains of Saccharomyces cerevisiae and Candida tropicalis to use as starter culture based on their ability to face ethanol toxicity. All the strains exhibited a relatively high resistance up to 5% ethanol. At 7.5% ethanol, S. cerevisiae F12-7 and C. tropicalis C0-7 were the most resistant strains with viability rate of 80-97% after 24 h of incubation. These two strains showed also the highest unsaturated/saturated fatty acids ratios. Values increased from 68.86% to 80.30% and from 72.97 to 85.96% respectively for S. cerevisiae F12-7 and C. tropicalis C0-7 cultivated under 0% and 7.5% ethanol. The cellular neutral lipid composition differed markedly according to the yeast strains. With proportion of 36.73% for S. cerevisiae F12-7 and 78.75% for C. tropicalis C0-7, ergosterol was the most abundant neutral lipid founded in the strains membranes. In addition, phosphatidylethanolamine contents decreased with the increase of ethanol concentration in the culture medium on contrary to phosphatidylcholine contents. These two strains were so suggested as starter cultures for sorghum beer production. © All Rights Reserved

Le polyéthylène téréphtalate, un emballage pour le vin ? Partie 1/2 : propriétés barrière, sécurité sanitaire, analyse du cycle de vie

National audienceUn programme de recherche collaborative, le projet NOVINPAK®, s’est déroulé de décembre 2010 à Juin 2014 afin de proposer un conditionnement innovant. L’objectif était de développer une solution allégée en PET monocouche, 100% recyclable, incluant 25% de PET-recyclé minimum qui s’insère au mieux dans les filières de recyclage et de valorisation actuelles et qui possède des propriétés barrières optimales vis-à-vis de l’oxygène et des arômes pour assurer le maintien de la qualité du vin dans le temps. Ce programme, de recherche financé par le Fond Unique Interministériel, et réalisé par les industriels VAL d’ORBIEU–UCCOAR en tant que chef de file, SIDEL et PURE ENVIRONNEMENT en collaboration avec des partenaires de recherche institutionnels, a permis de développer une solution éco-conçue de bouteilles de vin en PET pour vin de qualité. Sont présentés ici les principaux résultats de cette étude, sur les axes matériaux (allègement, intégration de PET-recyclé, intégration de barrières à l’oxygène dans le PET monocouche), les résultats des tests de migration pour la sécurité sanitaire ainsi que les résultats de l’analyse du cycle de vie (ACV). Un second article présentera plus en détails, l’évolution des gaz, du SO2 et les analyses sensorielles effectuées en comparaison à un conditionnement de référence, la bouteille en verre 75cL, tout au long du stockage sur 12 mois

The antiapoptotic protein AAC-11 interacts with and regulates Acinus-mediated DNA fragmentation

The nuclear factor Acinus has been suggested to mediate apoptotic chromatin condensation after caspase cleavage. However, this role has been challenged by recent observations suggesting a contribution of Acinus in apoptotic internucleosomal DNA cleavage. We report here that AAC-11, a survival protein whose expression prevents apoptosis that occurs on deprivation of growth factors, physiologically binds to Acinus and prevents Acinus-mediated DNA fragmentation. AAC-11 was able to protect Acinus from caspase-3 cleavage in vivo and in vitro, thus interfering with its biological function. Interestingly, AAC-11 depletion markedly increased cellular sensitivity to anticancer drugs, whereas its expression interfered with drug-induced cell death. AAC-11 possesses a leucine-zipper domain that dictates, upon oligomerization, its interaction with Acinus as well as the antiapoptotic effect of AAC-11 on drug-induced cell death. A cell permeable peptide that mimics the leucine-zipper subdomain of AAC-11, thus preventing its oligomerization, inhibited the AAC-11–Acinus complex formation and potentiated drug-mediated apoptosis in cancer cells. Our results, therefore, show that targeting AAC-11 might be a potent strategy for cancer treatment by sensitization of tumour cells to chemotherapeutic drugs