General Considerations Risk Assessment of Marine Toxins, T. Aune Analysis of Marine Toxins - Techniques, Method Validation, Calibration Standards and Screening Methods, P. Holland The Epidemiological Impact of Toxic Episodes Diarrheic Toxins, J. Gestal Neurotoxic Toxins, B. Gessner and J.B. McLaughlin Diversity of Marine Toxins as Pharmacological Tools Calcium Channels for Exocytosis: Functional Modulation with Toxins, A. Garcia The Mouse Bioassay as a Universal Detector, L.M Botana Paralytic Shellfish Poisoning (PSP) Metabolism of Paralytic Shellfish Toxins Incorporated into Bivalve, M. Kodama Chemical Analysis, B. Ben and A. Villar Pharmacology and Toxicology: Biological Detection Methods, B. Suarez Diarrheic Episodes: Phosphatase Inhibitors. Chemistry, Metabolism, Chemical Analysis of OA Group Toxins, P. MacNabb Pharmacology and Toxicology, A. Tubaro Lipophyllic Toxins: Non-phosphatase Inhibitors Planktonic Dinoflagellates which Produce Polyether Toxins of the Old "DSP Complex", B. Reguera Yessotoxins Chemistry, Metabolism, Chemical Analysis, E. Fatorusso and P. Ciminello Pharmacology and Mechanism of Action: Biological Detection, A. Alfonso Toxicology of the Yessotoxins, R. Munday Pectenotoxins Chemistry, Metabolism, and Chemical Detection Methods of Pectenotoxins, T. Suzuki Pharmacology of Pectenotoxins, N. Vilarino Toxicology of Pectenotoxins, R. Munday Domoic Acid Intoxication Ecobiology of ASP Producing Diatoms, Y. Kotaki Domoic Acid: Detection Methods, Pharmacology and Toxicology, A. Tasker Non-PSP Neurotoxic Episodes The Ecobiology of the Brevetoxin, Ciguatoxin and Cyclic Imine Producers, L. Mackenzie Ciguatera Toxins Ciguatera Toxins: Chemistry, Toxicology and Detection, R. Dickey Maitotoxin Maitotoxin: a Unique Pharmacological T ool for Elucidating Ca2+-Dependent Mechanisms, A. Darszon Brevetoxins The Molecular and Integrative Basis to Brevetoxin Toxicity, J. Ramsdell Dection of Brevetoxins in the 21st Century, M. Poli Cyclic Imines and Spirolides Cyclic Imine Toxins: Chemistry, Biogeography, Biosynthesis and Pharmacology, A. Cembella Toxicology of Cyclic Imines: Gymnodimine, Spirolides, Pinnatoxins, Pteriatoxins, Prorocentrolide, Spiro-Prorpcentrimine, and Symbiomines, R. Munday Polycavernosides: Gambierol Polycavernosides: Gambierol, Chemistry, Pharmacology, Toxicology, and Detection, C. Louzao Palytoxin, Ostreocin, Ovatatoxin Palytoxin and Analogues: Ecobiology and Origin. Chemistry, Metabolism and Chemical Analisis, P. Katikou Diverse Chemical Structures and Bioactivities of Marine Toxin: Palytoxin and Symbiodinolide, D.Uemura Palytoxins: Pharmacology and Biological Detection Methods, C. Vale Occurrence and Toxicology of Palytoxins, R. Munday Pfiesteria Toxins Pfiesteria spp. Toxins: Unresolved Questions and an Alternative Hypotheses, G. Vasta and A. Place Azaspiracids Pharmacology and Epidemiological Impact of Azaspiracids, M. Ryan Azaspiracids: Chemistry, Bioconversion and Determination, K. James Toxicology of Azaspiracid 1, E. Ito Cyanobacterial Toxins Cyanobacterial Toxins in Aquaculture, P.T Smith Neurotoxins Cyanobacterial Neurotoxins, Anatoxin-a and Analogues: Detection and Analysis, K. James Hepatotoxins Cyanobacterial Hepatotoxins: Chemistry, Biosynthesis, and Occurrence, M. Welker Hepatotoxins: Context and Chemical Determination, K. James Toxins as a Starting Point to Drugs Marine Neurotoxins as a Starting Point to Drugs, M.R. Waters Legal and Economical Views Incidence of Marine Toxins on Industrial Activity, J M Vieites Toxin Monitoring Programs and Regulatory View, M.L. Rodriguez-Velasco

Seafood and freshwater toxins : pharmacology, physiology, and detection

Several Dinophysis species produce diarrhoetic toxins (okadaic acid and dinophysistoxins) and pectenotoxins, and cause gastointestinal illness, Diarrhetic Shellfish Poisoning (DSP), even at low cell densities (<103 cells·L−1). They are the main threat, in terms of days of harvesting bans, to aquaculture in Northern Japan, Chile, and Europe. Toxicity and toxin profiles are very variable, more between strains than species. The distribution of DSP events mirrors that of shellfish production areas that have implemented toxin regulations, otherwise misinterpreted as bacterial or viral contamination. Field observations and laboratory experiments have shown that most of the toxins produced by Dinophysis are released into the medium, raising questions about the ecological role of extracelular toxins and their potential uptake by shellfish. Shellfish contamination results from a complex balance between food selection, adsorption, species-specific enzymatic transformations, and allometric processes. Highest risk areas are those combining Dinophysis strains with high cell content of okadaates, aquaculture with predominance of mytilids (good accumulators of toxins), and consumers who frequently include mussels in their diet. Regions including pectenotoxins in their regulated phycotoxins will suffer from much longer harvesting bans and from disloyal competition with production areas where these toxins have been deregulated.

/pdf/dinophysis-toxins-causative-organisms-distribution-and-fate-1jd21t8ed2.pdf

Dinophysis Toxins: Causative Organisms, Distribution and Fate in Shellfish

Publisher Summary Tumor promotion by the okadaic acid class of compounds binds to the okadaic acid receptors protein phosphatases 1 and 2A (PP-1 and PP-2A), which inhibit their activities. It results in an increase of phosphorylation of proteins in the cells. This chapter reviews the okadaic acid class of tumor promoters and discusses the significance of inhibition of PP-1 and PP-2A—the okadaic acid pathway—in the study of tumor promotion. Two-stage carcinogenesis experiments with the okadaic acid class of compounds established a general mechanism of tumor promotion for various organs. Okadaic acid was subjected to screening system for 12- O- tetradecanoylphorbol-13-acetate (TPA)-type tumor promoters, which consist of three successive tests. Okadaic acid responded differently from TPA in the three tests. Thirty okadaic acid class compounds include four structurally different types—namely, okadaic acid, calyculin, microcystin, and tautomycin. The tumor promotion on mouse skin, rat glandular stomach, and the treatment of okadaic acid with teleocidin or TPA are also discussed in the chapter. Okadaic acid and teleocidin showed about the same potencies for production of papillomas and carcinomas during tumor promotion. The structure, distribution, gene expression, and biochemical effects of okadaic acid class compounds are also summarized.

Tumor promotion by inhibitors of protein phosphatases 1 and 2A: the okadaic acid class of compounds.

The effect of structural modifications of okadaic acid (OA), a polyether C38 fatty acid, was studied on its inhibitory activity toward type 1 and type 2A protein phosphatases (PP1 and PP2A) by using OA derivatives obtained either by isolation from natural sources or by chemical processes. The dissociation constant (Ki) for the interaction of OA with PP2A was estimated to be 30 (26-33) nM [median (95% confidence limits)]. The OA derivatives used and their affinity for PP2A, expressed as Ki (in brackets) were as follows: 35-methyl-OA (DTX1) [19 (12-25) pM], OA-9,10-episulphide (acanthifolicin) [47 (25-60) pM], 7-deoxy-OA [69 (31-138) pM], 14,15-dihydro-OA [315 (275-360) pM], 2-deoxy-OA [899 (763-1044) pM], 7-O-palmitoyl-OA [greater than 100 nM], 7-O-palmitoyl-DTX1 [greater than 100 nM], methyl okadate [much greater than 100 nM], 2-oxo-decarboxy-OA [much greater than 100 nM] and the C-15-C-38 fragment of OA [much greater than 100 nM]. The sequence of the affinity of these derivatives for PP1 was essentially the same as that observed with PP2A, although the absolute values of Ki were very different for the enzymes. The inhibitory effect of OA on PP2A was reversed by applying a murine monoclonal antibody against OA, which recognizes modifications of the 7-hydroxyl group of the OA molecule. It has been shown by n.m.r. spectroscopy and X-ray analysis that one end (C-1-C-24) of the OA molecule assumes a circular conformation. The present results suggest the importance of the conformation for the inhibitory action of OA on the protein phosphatases. The ratios of the Ki values for PP1 to that for PP2A, which were within the range 10(3)-10(4), tended to be smaller for the derivatives with lower affinity, indicating that the structural changes in OA impaired the affinity for PP2A more strongly than that for PP1.

/pdf/inhibitory-effect-of-okadaic-acid-derivatives-on-protein-458hoy0sle.pdf

Inhibitory effect of okadaic acid derivatives on protein phosphatases. A study on structure-affinity relationship.

The phosphatase activities of type 2A, type 1 and type 2C protein phosphatase preparations were measured against p-nitrophenyl phosphate (pNPP), a commonly used substrate for alkaline phosphatases. Of the three types of phosphatase examined, the type 2A phosphatase exhibited an especially high pNPP phosphatase activity (119 +/- 8 mumol/min per mg of protein; n = 4). This activity was strongly inhibited by pico- to nano-molar concentrations of okadaic acid, a potent inhibitor of type 2A and type 1 protein phosphatases that has been shown to have no effect on alkaline phosphatases. The dose-inhibition relationship was markedly shifted to the right and became steeper by increasing the concentration of the enzyme, as predicted by the kinetic theory for tightly binding inhibitors. The enzyme concentration estimated by titration with okadaic acid agreed well with that calculated from the protein content and the molecular mass for type 2A phosphatase. These results strongly support the idea that the pNPP phosphatase activity is intrinsic to type 2A protein phosphatase and is not due to contamination by alkaline phosphatases. pNPP was also dephosphorylated, but at much lower rates, by type 1 phosphatase (6.4 +/- 8 nmol/min per mg of protein; n = 4) and type 2C phosphatase (1.2 +/- 3 nmol/min per mg of protein; n = 4). The pNPP phosphatase activity of the type 1 phosphatase preparation shows a susceptibility to okadaic acid similar to that of its protein phosphatase activity, whereas it was interestingly very resistant to inhibitor 2, an endogenous inhibitory factor of type 1 protein phosphatase. The pNPP phosphatase activity of type 2C phosphatase preparation was not affected by up to 10 microM-okadaic acid.

Inhibitory effect of okadaic acid on the p-nitrophenyl phosphate phosphatase activity of protein phosphatases.

Preparation of monoclonal antibodies against okadaic acid prepared from the sponge Halichondria okadai.

Preparation of monoclonal antibodies against methamphetamine.

Enzyme immunoassay using monoclonal antibody specific for diarrhetic shellfish poisons

A mycotoxin such as ochratoxin A, T-2 toxin or aflatoxin B1 is assayed under competitive reaction conditions by using an enzyme-labelled monoclonal antibody to the mycotoxin.

Mycotoxin assay reagent and assay method

A monoclonal antibody to methamphet­amine which is produced by a cell strain obtained by immunization of animal; a method for preparing a monoclonal antibody to methamphetamine which comprises culturing a cell strain producing a monoclonal antibody to methamphet­amine; a method for assay methamphetamine, which comprises allowing a methamphetamine-bound macromolecular protein immobilized on a solid phase support and meth­amphetamine in a sample to be assayed to react competi­tively with a reagent comprising a monoclonal antibody having very high specific immunoreactivity with methamphet amine labeled with an enzyme; a methamphetamine assay kit to be used in the method for assay methamphet­amine, which comprises essentially (a) a methamphetamine­bound macromolecular protein; and (b) a reagent comprising a monoclonal antibody having a very high specific immuno­reactivity with methamphetamine labeled with an enzyme; a method for assay methamphetamine, which comprises immobilizing a monoclonal antibody having a very high specific immunoreactivity with methamphetamine on a solid phase support, and allowing an enzyme-labeled methamphet­amine and methamphetamine in a sample to be assayed to react competitively with the monoclonal antibody immobi­lized on the solid phase support; and a methamphetamine assay kit to be used in the method for assay methamphetamine.

Monoclonal antibody to methamphetamine, preparation of the same, assay method and assay kit of methamphetamine

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