889 resultados para Plants, Protection of
Resumo:
This review summarizes the recent discovery of the cupin superfamily (from the Latin term "cupa," a small barrel) of functionally diverse proteins that initially were limited to several higher plant proteins such as seed storage proteins, germin (an oxalate oxidase), germin-like proteins, and auxin-binding protein. Knowledge of the three-dimensional structure of two vicilins, seed proteins with a characteristic beta-barrel core, led to the identification of a small number of conserved residues and thence to the discovery of several microbial proteins which share these key amino acids. In particular, there is a highly conserved pattern of two histidine-containing motifs with a varied intermotif spacing. This cupin signature is found as a central component of many microbial proteins including certain types of phosphomannose isomerase, polyketide synthase, epimerase, and dioxygenase. In addition, the signature has been identified within the N-terminal effector domain in a subgroup of bacterial AraC transcription factors. As well as these single-domain cupins, this survey has identified other classes of two-domain bicupins including bacterial gentisate 1, 2-dioxygenases and 1-hydroxy-2-naphthoate dioxygenases, fungal oxalate decarboxylases, and legume sucrose-binding proteins. Cupin evolution is discussed from the perspective of the structure-function relationships, using data from the genomes of several prokaryotes, especially Bacillus subtilis. Many of these functions involve aspects of sugar metabolism and cell wall synthesis and are concerned with responses to abiotic stress such as heat, desiccation, or starvation. Particular emphasis is also given to the oxalate-degrading enzymes from microbes, their biological significance, and their value in a range of medical and other applications.
Resumo:
We previously found that dried live bacteria of a vaccine strain can be temporarily sensitive to bile acids and suggested that Bile Adsorbing Resins (BAR) can be used in oral vaccine tablets to protect dried bacteria from intestinal bile. Here, we report a quantitative analysis of the ability of BAR to exclude the dye bromophenol blue from penetrating into matrix tablets and also sections of hard capsule shells. Based on this quantitative analysis, we made a fully optimised formulation, comprising 25% w/w of cholestyramine in Vcaps™ HPMC capsules. This gave effectively 100% protection of viability from 4% bile, with 4200-fold more live bacteria recovered from this formulation compared to unprotected dry bacteria. From the image analysis, we found that the filler material or compaction force used had no measurable effect on dye exclusion but did affect the rate of tablet hydration. Increasing the mass fraction of BAR gave more exclusion of dye up to 25% w/w, after which a plateau was reached and no further dye exclusion was seen. More effective dye exclusion was seen with smaller particle sizes (i.e. cholestyramine) and when the BAR was thoroughly dried and disaggregated. Similar results were found when imaging dye penetration into capsule sections or tablets. The predictions of the dye penetration study were tested using capsules filled with dried attenuated Salmonella vaccine plus different BAR types, and the expected protection from bile was found, validating the imaging study. Surprisingly, depending on the capsule shell material, some protection was given by the capsule alone without adding BAR, with Vcaps™ HPMC capsules providing up to 174-fold protection against 1% bile; faster releasing Vcaps Plus™ HPMC capsules and Coni Snap™ gelatin capsules gave less protection.
Resumo:
We previously demonstrated that a dry, room temperature stable formulation of a live bacterial vaccine was highly susceptible to bile, and suggested that this will lead to significant loss of viability of any live bacterial formulation released into the intestine using an enteric coating or capsule. We found that bile and acid tolerance is very rapidly recovered after rehydration with buffer or water, raising the possibility that rehydration in the absence of bile prior to release into the intestine might solve the problem of bile toxicity to dried cells. We describe here a novel formulation that combines extensively studied bile acid adsorbent resins with the dried bacteria, to temporarily adsorb bile acids and allow rehydration and recovery of bile resistance of bacteria in the intestine before release. Tablets containing the bile acid adsorbent cholestyramine release 250-fold more live bacteria when dissolved in a bile solution, compared to control tablets without cholestyramine or with a control resin that does not bind bile acids. We propose that a simple enteric coated oral dosage form containing bile acid adsorbent resins will allow improved live bacterial delivery to the intestine via the oral route, a major step towards room temperature stable, easily administered and distributed vaccine pills and other bacterial therapeutics
Resumo:
This article examines the EU’s promotion of the religious identity of Muslims within the context of European counter-terrorism measures. Counter-terrorism laws of the EU and its Member States impact on the religious identity of Muslims. They have an arguably disproportionate effect on the civil rights of individuals in the quest to combat terrorism and can be seen to increase Islamophobia in two ways: a rise in general discrimination against Muslims and a requirement on Muslims to distance their connection to Islamic practice and traditions. EU law dealing with terrorist offences speak little of this backlash that Muslims face in European countries. Although the EU has somewhat of a framework in place which concerns the protection of Islamic identity, the reluctance of the EU to take a determined stance on the issue of the protection of religious identity is illustrated through the ambiguous nature of its legislation.
Resumo:
Cash-constrained wildlife departments must increasingly look towards revenue-generating activities such as sales of permits for hunting common species combined with fines for those caught with rare species. Pertinent to west Africa, an optimal enforcement model demonstrates the conditions under which a department with neither external budget nor tourism revenue can fully protect a rare species, and the impact on other species and local hunters' livelihoods. The department's effectiveness is shown to depend critically on the extent to which hunters can discriminate among different species. Improvements in hunting technology selectivity are therefore a substitute for increased enforcement spending.
Resumo:
The European Union (EU) is embedded in a pluralistic legal context because of the EU and its Member States’ treaty memberships and domestic laws. Where EU conduct has implications for both the EU’s international trade relations and the legal position of individual traders, it possibly affects EU and its Member States’ obligations under the law of the World Trade Organization (WTO law) as well as the Union’s own multi-layered constitutional legal order. The present paper analyses the way in which the European Court of Justice (ECJ) accommodates WTO and EU law in the context of international trade disputes triggered by the EU. Given the ECJ’s denial of direct effect of WTO law in principle, the paper focuses on the protection of rights and remedies conferred by EU law. It assesses the implications of the WTO Dispute Settlement Understanding (DSU) – which tolerates the acceptance of retaliatory measures constraining traders’ activities in sectors different from those subject to the original trade dispute (Bananas and Hormones cases) – for the protection of ‘retaliation victims’. The paper concludes that governmental discretion conferred by WTO law has not affected the applicability of EU constitutional law but possibly shapes the actual scope of EU rights and remedies where such discretion is exercised in the EU’s general interest.
Resumo:
Enteric coated oral tablets or capsules can deliver dried live cells directly into the intestine. Previously, we found that a live attenuated bacterial vaccine acquired sensitivity to intestinal bile when dried, raising the possibility that although gastric acid can be bypassed, significant loss of viability might occur on release from an enteric coated oral formulations. Here we demonstrate that some food-grade lyophilised preparations of Lactobacillus casei and Lactobacillus salivarius also show temporary bile sensitivity that can be rapidly reversed by rehydration. To protect dried bacterial cells from temporary bile sensitivity, we propose using bile acid adsorbing resins, such as cholestyramine, which are bile acid binding agents, historically used to lower cholesterol levels. Vcaps™ HPMC capsules alone provided up to 830-fold protection from bile. The inclusion of 50% w/w cholestyramine in Vcaps™ HPMC capsules resulted in release of up to 1700-fold more live Lactobacillus casei into simulated intestinal fluid containing 1% bile, when compared to dried cells added directly to bile. We conclude that delivery of dried live probiotic organisms to the intestine may be improved by providing protection from bile by addition of bile adsorbing resins and the use of HPMC capsules.