Philipp Hess
Ifremer, Laboratoire Phycotoxines, Department Member
Background: Seafood toxins pose an important risk to human health, and maximum levels were imposed by regulatory authorities throughout the world. Several toxin groups are known, each one with many analogues of the major toxin. Regulatory... more
Background: Seafood toxins pose an important risk to human health, and maximum levels were imposed by regulatory authorities throughout the world. Several toxin groups are known, each one with many analogues of the major toxin. Regulatory limits are set to ensure that commercially available seafood is not contaminated with unsafe levels. Scope and approach: The mouse bioassay was used to measure the toxicity in seafood extracts to determine if a sample exceeded regulatory limits. The advantage of this approach was to provide an estimation of the total toxicity in the sample. As instrumental methods of analysis advance and serve as replacements to the mouse bioassay, the challenge is translating individual toxin concentrations into toxicity to determine whether regulatory limits have been exceeded. Such analyses provide accurate quantitation of the toxin analogues, by they have widely dissimilar potencies. Thus, knowledge of the relative toxicities is required for risk assessment and determining overall toxicity. The ratios between the toxicity of the analogues and that of a reference compound within the same toxin group are termed " Toxicity Equivalency Factors " (TEFs). Key findings and conclusions: In this document, the requirements for determining TEFs of toxin analogues are described, and recommendations for research to further refine TEFs are identified. The proposed TEFs herein, when applied to toxin analogue concentrations determined using analytical methods, will provide a base to determine overall toxicity, thereby protecting human health.
Research Interests:
Background: Seafood toxins pose an important risk to human health, and maximum levels were imposed by regulatory authorities throughout the world. Several toxin groups are known, each one with many analogues of the major toxin. Regulatory... more
Background: Seafood toxins pose an important risk to human health, and maximum levels were imposed by regulatory authorities throughout the world. Several toxin groups are known, each one with many analogues of the major toxin. Regulatory limits are set to ensure that commercially available seafood is not contaminated with unsafe levels. Scope and approach: The mouse bioassay was used to measure the toxicity in seafood extracts to determine if a sample exceeded regulatory limits. The advantage of this approach was to provide an estimation of the total toxicity in the sample. As instrumental methods of analysis advance and serve as replacements to the mouse bioassay, the challenge is translating individual toxin concentrations into toxicity to determine whether regulatory limits have been exceeded. Such analyses provide accurate quantitation of the toxin analogues, by they have widely dissimilar potencies. Thus, knowledge of the relative toxicities is required for risk assessment and determining overall toxicity. The ratios between the toxicity of the analogues and that of a reference compound within the same toxin group are termed " Toxicity Equivalency Factors " (TEFs). Key findings and conclusions: In this document, the requirements for determining TEFs of toxin analogues are described, and recommendations for research to further refine TEFs are identified. The proposed TEFs herein, when applied to toxin analogue concentrations determined using analytical methods, will provide a base to determine overall toxicity, thereby protecting human health.
Research Interests:
Research Interests:
Background: Seafood toxins pose an important risk to human health, and maximum levels were imposed by regulatory authorities throughout the world. Several toxin groups are known, each one with many analogues of the major toxin. Regulatory... more
Background: Seafood toxins pose an important risk to human health, and maximum levels were imposed by regulatory authorities throughout the world. Several toxin groups are known, each one with many analogues of the major toxin. Regulatory limits are set to ensure that commercially available seafood is not contaminated with unsafe levels. Scope and approach: The mouse bioassay was used to measure the toxicity in seafood extracts to determine if a sample exceeded regulatory limits. The advantage of this approach was to provide an estimation of the total toxicity in the sample. As instrumental methods of analysis advance and serve as replacements to the mouse bioassay, the challenge is translating individual toxin concentrations into toxicity to determine whether regulatory limits have been exceeded. Such analyses provide accurate quantitation of the toxin analogues, by they have widely dissimilar potencies. Thus, knowledge of the relative toxicities is required for risk assessment and determining overall toxicity. The ratios between the toxicity of the analogues and that of a reference compound within the same toxin group are termed " Toxicity Equivalency Factors " (TEFs). Key findings and conclusions: In this document, the requirements for determining TEFs of toxin analogues are described, and recommendations for research to further refine TEFs are identified. The proposed TEFs herein, when applied to toxin analogue concentrations determined using analytical methods, will provide a base to determine overall toxicity, thereby protecting human health.
Research Interests:
Background: Seafood toxins pose an important risk to human health, and maximum levels were imposed by regulatory authorities throughout the world. Several toxin groups are known, each one with many analogues of the major toxin. Regulatory... more
Background: Seafood toxins pose an important risk to human health, and maximum levels were imposed by regulatory authorities throughout the world. Several toxin groups are known, each one with many analogues of the major toxin. Regulatory limits are set to ensure that commercially available seafood is not contaminated with unsafe levels. Scope and approach: The mouse bioassay was used to measure the toxicity in seafood extracts to determine if a sample exceeded regulatory limits. The advantage of this approach was to provide an estimation of the total toxicity in the sample. As instrumental methods of analysis advance and serve as replacements to the mouse bioassay, the challenge is translating individual toxin concentrations into toxicity to determine whether regulatory limits have been exceeded. Such analyses provide accurate quantitation of the toxin analogues, by they have widely dissimilar potencies. Thus, knowledge of the relative toxicities is required for risk assessment and determining overall toxicity. The ratios between the toxicity of the analogues and that of a reference compound within the same toxin group are termed " Toxicity Equivalency Factors " (TEFs). Key findings and conclusions: In this document, the requirements for determining TEFs of toxin analogues are described, and recommendations for research to further refine TEFs are identified. The proposed TEFs herein, when applied to toxin analogue concentrations determined using analytical methods, will provide a base to determine overall toxicity, thereby protecting human health.
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Research Interests:
ABSTRACT
... Carney Jimmy Sea Fisheries Protection Authority Chamberlain Tara Marine Institute Costello Patrick Marine Institute Condon Jim SFPA ... April Agri-Food & Bioscience Institute, Northern Ireland Mhic Ghiolla Chuda Clíona Meitheal... more
... Carney Jimmy Sea Fisheries Protection Authority Chamberlain Tara Marine Institute Costello Patrick Marine Institute Condon Jim SFPA ... April Agri-Food & Bioscience Institute, Northern Ireland Mhic Ghiolla Chuda Clíona Meitheal Trá Mulcahy Diarmuid Aquatask Enterprises Ltd. ...
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Monitoring for amnesic shellfish poisons (ASP) in wild and cultivated molluscs from Scottish waters commenced in 1998, following the of introduction of revised legislation from the European Community. The principle toxic compound, domoic... more
Monitoring for amnesic shellfish poisons (ASP) in wild and cultivated molluscs from Scottish waters commenced in 1998, following the of introduction of revised legislation from the European Community. The principle toxic compound, domoic acid (DA), was detected in a range of species and in some instances at concentrations above the regulatory limit. Although some harvesting closures were implemented in 1998, ASP caused much greater problems the following year. In 1999, the majority of scallop
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For decades, many aspects of Dinophysis biology have remained intractable due to our inability to maintain these organisms in laboratory cultures. Recent breakthroughs in culture methods have opened the door for detailed investigations of... more
For decades, many aspects of Dinophysis biology have remained intractable due to our inability to maintain these organisms in laboratory cultures. Recent breakthroughs in culture methods have opened the door for detailed investigations of these important algae. Here, for the first time, we demonstrate toxin production in cultures of North American Dinophysis acuminata, isolated from Woods Hole, MA. These findings show that, despite the rarity of Dinophysis-related DSP events in North America, D. acuminata from this area has the ability to produce DSP toxins just as it does in other parts of the world where this species is a major cause of DSP toxicity. In our cultures, D. acuminata cells were observed feeding on Myrionecta rubra using a peduncle. Culture extracts were analyzed using LC–MS/MS, providing unequivocal evidence for the toxin DTX1 in the Dinophysis cultures. In addition, a significant amount of an okadaic acid diol ester, OA-D8, was detected. These results suggest that th...
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For many years, the study of toxic Dinophysis species was primarily restricted to field populations until it was recently demonstrated that some of these organisms can be mixotrophically cultured in the laboratory with the ciliate prey,... more
For many years, the study of toxic Dinophysis species was primarily restricted to field populations until it was recently demonstrated that some of these organisms can be mixotrophically cultured in the laboratory with the ciliate prey, Myrionecta rubra. which had previously been fed with cryptophytes of the genus Teleaulax and Geminigera. Here we investigated the influence of growth phase and light intensity on the production of diarrhetic shellfish poisoning (DSP) toxins and pectenotoxins (PTXs) in cultures of Dinophysis acuminata from the northeastern United States. The cell toxin content of okadaic acid (OA), dinophysistoxin-1 (DTX1), pectenotoxin-2 (PTX2), and the okadaic acid diol ester (OA-D8) varied significantly with growth phase under all light treatments, at 6 degrees C. Each toxin quota remained low during middle and late exponential phases, but significantly increased by mid-plateau phase. DTX1 and OA-D8 were variable through plateau phase, while OA and PTX2 significant...
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Liquid chromatography coupled to mass spectrometry (LC-MS) is seen as an integral part of methods of choice for the replacement of animal tests in the determination of lipophilic shellfish toxins. However, these techniques are prone to... more
Liquid chromatography coupled to mass spectrometry (LC-MS) is seen as an integral part of methods of choice for the replacement of animal tests in the determination of lipophilic shellfish toxins. However, these techniques are prone to matrix effects that need to be considered when developing and validating methods. The analysis of shellfish is a challenging task due to the complexity of the shellfish matrix and the number of shellfish species encountered in monitoring laboratories. Therefore, it is crucial that the cause and the extent of matrix effects is fully understood in order to apply corrective measures to the analytical method and to develop efficient sample clean-up steps. This paper presents different approaches to evaluate matrix effects associated with the analysis of okadaic acid (OA), azaspiracid-1 (AZA1) and pectenotoxin-2 (PTX2) in cooked and raw mussel flesh. Post-extraction addition and standard addition experiments were carried out and analysed using various LC-M...
Research Interests: Mass Spectrometry, Animals, Marine Toxins, High Performance Liquid Chromatography, High Pressure Liquid Chromatography, and 10 moreLiquid Chromatography / Electrospray Ionization Mass Spectrometry, Analytical Method, Liquid Chromatography, Mytilus edulis, Food Contamination, Food Sciences, Condition Assessment, Furans, *Hot Temperature, and Okadaic acid
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Azaspiracids (AZAs) are marine biotoxins produced by dinoflagellates that can accumulate in shellfish, which if consumed can lead to poisoning events. AZA7-10, 7-10, were isolated from shellfish and their structures, previously proposed... more
Azaspiracids (AZAs) are marine biotoxins produced by dinoflagellates that can accumulate in shellfish, which if consumed can lead to poisoning events. AZA7-10, 7-10, were isolated from shellfish and their structures, previously proposed on the basis of only LC-MS/MS data, were confirmed by NMR spectroscopy. Purified AZA4-6, 4-6, and 7-10 were accurately quantitated by qNMR and used to assay cytotoxicity with Jurkat T lymphocyte cells for the first time. LC-MS(MS) molar response studies performed using isocratic and gradient elution in both selected ion monitoring and selected reaction monitoring modes showed that responses for the analogues ranged from 0.3 to 1.2 relative to AZA1, 1. All AZA analogues tested were cytotoxic to Jurkat T lymphocyte cells in a time- and concentration-dependent manner; however, there were distinct differences in their EC50 values, with the potencies for each analogue being: AZA6 > AZA8 > AZA1 > AZA4 ≈ AZA9 > AZA5 ≈ AZA10. This data contributes to the understanding of the structure-activity relationships of AZAs.
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In the present study, okadaic acid (OA) and dinophysistoxin-1 (DTX1) were spiked into artificial seawater at low, medium and high estuarine salinities (9‰, 13.5‰ and 27‰). Passive samplers (HP20 resin) used for solid phase adsorption... more
In the present study, okadaic acid (OA) and dinophysistoxin-1 (DTX1) were spiked into artificial seawater at low, medium and high estuarine salinities (9‰, 13.5‰ and 27‰). Passive samplers (HP20 resin) used for solid phase adsorption toxin tracking (SPATT) technology were exposed in these seawaters for 12-h periods. Adsorption curves well fitted a pseudo-secondary kinetics model. The highest initial sorption rates of both toxins occurred in the seawater of medium salinity, followed by seawater of low and high estuarine salinity. Pore volumes of micropores (<2 nm) and small mesopores (2 nm<diameter<10nm) of HP20 resin decreased after adsorption of toxins in seawater at high and low salinity but not in seawater at medium salinity, which demonstrated that the toxin molecules entered into micropores and mesopores (below 10nm in size) in seawaters of high and low salinity. More toxin or other matrix agglomerates were displayed on the surface of resin deployed in the seawater of ...
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The European Marine Board recently published a position paper on linking oceans and human health as a strategic research priority for Europe. With this position paper as a reference, the March 2014 Cornwall Oceans and Human Health... more
The European Marine Board recently published a position paper on linking oceans and human health as a strategic research priority for Europe. With this position paper as a reference, the March 2014 Cornwall Oceans and Human Health Workshop brought together key scientists, policy makers, funders, business, and non governmental organisations from Europe and the US to review the recent interdisciplinary and cutting edge research in oceans and human health specifically the growing evidence of the impacts of oceans and seas on human health and wellbeing (and the effects of humans on the oceans). These impacts are a complex mixture of negative influences (e.g. from climate change and extreme weather to harmful algal blooms and chemical pollution) and beneficial factors (e.g. from natural products including seafood to marine renewable energy and wellbeing from interactions with coastal environments). Integrated approaches across disciplines, institutions, and nations in science and policy ...
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... of ascorbic acid and dehydroascorbic acid. Lucie Nováková a , Corresponding Author Contact Information , E-mail The Corresponding Author , Dagmar Solichová b and Petr Solich a. a Department of Analytical Chemistry, Faculty ...
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... 5Research Centre for Pathogenic Fungi &amp;amp; Microbial Toxicoses, Chiba University, 1-8-1, Inohanam, Chuo-ku, Chiba 260-8673, Japan. 6Japan Food Research Laboratories, Tama Laboratory, 6-11-10, Nagayama, Tama-shi, Tokyo 2060025... more
... 5Research Centre for Pathogenic Fungi &amp;amp; Microbial Toxicoses, Chiba University, 1-8-1, Inohanam, Chuo-ku, Chiba 260-8673, Japan. 6Japan Food Research Laboratories, Tama Laboratory, 6-11-10, Nagayama, Tama-shi, Tokyo 2060025 Japan. ...
ABSTRACT The bioactivity of phytoplankton toxins that accumulate in shellfish is almost always tested on animal model (mice assay). In spite of these advantages, the ability of this test to explain the nature of the bioactivity remains... more
ABSTRACT The bioactivity of phytoplankton toxins that accumulate in shellfish is almost always tested on animal model (mice assay). In spite of these advantages, the ability of this test to explain the nature of the bioactivity remains limited. Besides, the current sanitary control based on targeted methods of identification and quantification (LC-MS/MS) of known toxins, do not permit to detect unknown toxins. In order to cope with this need of identification of unknown toxic substances, a next approach based on global and differential metabolomic profiling was proposed. The first results obtained from extracts that have shown a positive toxicity in mice without the substances potentially responsible for these toxic effects have been measured by targeted methods, clearly open new perspectives regarding this atypical toxicity issue. This concept allows identifying a biological signature associated with this toxicity and shows the interest of characterizing biomarkers, which are potential candidates for the establishment of a new control strategy. Validity and robustness of this approach have now to be confirmed at a larger scale.