Toxins, adsorption

Mackenzie, L., V. Beuzenberg, P. Holland, P. McNabb, and A. Selwood. 2004. Solid phase adsorption toxin tracking (Spatt) A new monitoring tool that simulates the biotoxin contamination of filter feeding bivalves. Toxicon 44 901-918. 

MacKenzie, L., Holland, P, McNabb, R, Beuzenberg, V, Selwood, A., and Suzuki, T. 2002. Complex toxin profiles in phytoplankton and Greenshell mussels (Rerna canaliculus), revealed by LC-MS/MS analysis. Toxicon 40, 1321-1330. MacKenzie, A.L., Beuzenberg, Y, Holland, R.T., McNabb, R, and Selwood, A.R. 2004. Solid-phase adsorption toxin tracking (SPATT) a new monitoring tool that simulates the biotoxin contamination of filter-feeding bivalves. Toxicon 44 901-918. 

It has also been demonstrated that styrene—DVB copolymer resins Sepabeads SP825, Sepabeads SP850, Optipore L-493, Diaion HP-20, and Amberlite XAD-4, of which the first three have a surface area of 1000 m /g and might be attributed to hypercrosshnked sorbents, accumulate lipophilic marine toxins okadaic acid and dinophysistoxin-1 from Prorocentrum lima cultures [298]. The procedure developed in the study represents a simple and efficient method suitable for solid-phase adsorption toxin tracking in both cultural fiquids and natural waters. The toxins are eluted from the resins with methanol and subjected to LC-MS analysis. 

Anthrax Medium from cuitures of B. anthracis 1 Separation of protective antigen from medium 2 Adsorption 3 + 3 quantal assay in guinea-pigs using challenge with B. anthracis Exclusion of live 6. anthracis and of anthrax toxin... 

Diphtheria (adsorbed) Cultures of C. diphtheriae in liquid medium 1 Separation and concentration of toxin 2 Conversion of toxin to toxoid 3 Adsorption of toxoid to adjuvant 3+3 quantal assay in guinea-pigs using intra-dermal challenge Inoculation of guinea-pigs to exclude residual toxin... 

Tetanus (adsorbed) Cultures of Cl. tetani in liquid medium 1 Conversion of toxin to toxoid 2 Separation and purification of toxoid 3 Adsorption to adjuvant 3 + 3 quantal assay in mice using subcutaneous challenge with tetanus toxin Inoculation of guinea-pigs to exclude presence of untoxoided toxin... 

Sophisticated and veiy sensitive methods have been developed in the food industry for detecting many other microbial toxins. For example, aflatoxin deteetion in seedstuffs and their oils is performed by solvent extraction, adsorption onto columns containing selective antibodies for them, and detected by exposure to ultraviolet light. 

Minimization of agricultural losses from soil toxins Toxins from soils appear to be responsible for inhibition of nitrogen fixation, metabolism and nodulation in legumes. Removal of toxins could be achieved by proper adsorption techniques and also by growing companion plants that contribute organic matter to microoranisms which help to destroy or degrade toxic chemicals. 

The nature section of the BBC Website describes several examples of animals eating kaolin clay to immobilize toxins by adsorption on the clay s surface. For example, see the first entry on the page http //www.bbc.co.uk/nature/weird/az/mo.shtml. Alternatively, read The Life of Mammals by Sir David Attenborough, BBC Books, 2002, p. 170. 

Decker, S.R Klabunde, J.S. Khaleel, A. Klabunde, K.J. Catalyzed destructive adsorption of environmental toxins with nanocrystalline metal oxides. Fluoro-, chloro-, bromocarbons, sulfur, and organophosphorus compounds. Environ. Sci. Technol. 2002, 36, 762-768. 

In order for allelochemicals to enter the body of a herbivore, absorption must occur across the gut lining. Curtailing the initial absorption of dietary allelochemicals may be a herbivore s first line of defense against plant toxins. Studies have citied the lack of absorption or metabolism of lipophilic plant secondary metabolites (i.e., terpenes), conducive to phase I or II detoxification, in the gut of terrestrial herbivores rather these compounds are excreted unchanged in the feces (Marsh et al. 2006b). While physical barriers or surfactants have been used to explain this limited adsorption in both marine and terrestrial herbivores (Lehane 1997 Barbehenn and Martin 1998 Barbehenn 2001 for review of marine herbivores, see Targett and Arnold 2001), active efflux of plant allelochemicals out of enterocytes into the gut lumen has received limited attention until now. 

Soil colloids are capable of adsorbing most allelopathic chemicals. Such adsorption would result in temporary loss of toxin activity. Chemical changes could occur during adsorption that would permanently deactivate the toxin. The adsorption reactions are usually reversible, however, so that some or all of the toxin would still be available for uptake by a receiver plant. 

The toxin is also likely to be adsorbed or complexed by soil humic acids. If the reaction is a simple adsorption reaction, all or part of the toxin might later become available for absorption by a receiver plant. If the toxin is complexed or precipitated by its reaction with soil humic substances, then it would be deactivated. 

Contrary to carbon enterosorbents, Enterosgel does not possess an ability for selective removal of albumin-bound ligands regardless of their affinity with the protein carrier - weak (L-tryptophane), medium (sodium caprylate, deoxycholic acid), or strong (indole-3-carboxylic acid and unconjugated bilirubin). It means that if protein-bound toxins are removed by Enterosgel, this occurs simultaneously with adsorption of the carrier protein. 

Weber V, Linsberger I, Hauner M et al (2008) Neutral styrene divinylbenzene copolymers for adsorption of toxins in Liver failure. Biomacromolecules 9(4) 1322-8... 

Colloidal bismuth compounds Subsalicylate and citrate salts available. OTC preparations popular and have some value in travelers diarrhea due to adsorption of toxins... 

Although certain simple functions of the liver, such as the removal of some toxins, can be performed by using dialysis and adsorption with activated charcoal, it is clear that such a simple artificial approach cannot perform the complex functions of the liver, and that any practical liver support system must use living hepatocytes. It should be mentioned at this point that hepatocytes have an anchorage-dependent nature that is, they require a form of anchor (i.e., a solid surface or scaffold) on which to grow. Thus, the use of single-cell suspensions is not appropriate for liver cell culture, and fiver cells attached to solid surfaces are normally used. Encapsulated fiver cells and spheroids (i.e., spherical aggregates of fiver cells) may also be used for this purpose. 

Ellipsometry can follow the interactions between two types of biological macromolecules, the first of those two bound physically to the surface, the other acting from the solution. The binding of conconavalin A to adsorbed mannan 180) and of cholera toxin to adsorbed ganglioside t83) are examples. The adsorption of complement factors to an antibody-coated surface was monitored by ellipsometry and a modification of the same method was used for quantification of migration inhibition of human polymorphonuclear leucocytes 182). Interaction of proteins and cells with affinity ligands covalently coupled to silicon surfaces has been also studied 183). 

Fux, E., C. Marcaillou, F. Mondeguer, R. Bire, and P. Hess. 2008. Field and mesocosm trials on passive sampling for the study of adsorption and desorption behaviour of lipophilic toxins with a focus on OA and DTX1. Harmful Algae 7 574-583. 

For this purpose, the removal procedures are mainly based on membrane separation that ideally should bring free and bound toxins to a nonspedfic adsorption device (ion-exchangers and/or activated charcoal). Blood should not perfuse directly such components, due to bioincompatibity aspeds. Therefore, several processes have been proposed to correctly handle toxins carried by plasma [27]. They are described in the following sections. All of them need a physical barrier between the blood cells and the adsorption system. This physical sieve is always a membrane with adequate properties, through which toxins can be transferred by diffusion or convection. 

The following processes can be described as selective therapeutic plasmapheresis. In a first step, blood is withdrawn from the patient and separated by crossflow filtration in a hollow-fiber membrane cartridge water and some plasma solutes are transferred through a semipermeable membrane under a convection process. The transmembrane pressure applied from blood to filtrate compartment ensures flow and mass transfers. Then, the filtrate perfuses the adsorption columns where toxins are retained and is finally mixed with blood cells and other plasma components before returning to the patient (Figure 18.11). 

The biologic activity of the silica surface depends on (1) high hydrophilicity of the surface, (2) high protein-sorbing activity, (3) binding of great numbers of microorganisms and microbial toxins, and (4) adsorption of low-molecular... 

Silica is known to have unique adsorption properties with respect to proteins, which makes it an ideal enterosorbent for protein-based toxins.13,14 A study was thus undertaken to investigate the origin of the affinity of albumin with silica. 

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