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| Registros recuperados: 91 | |
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| Fux, E; Marcaillou-le Baut, Claire; Mondeguer, Florence; Bire, R; Hess, Philipp. |
| It has been demonstrated that polymeric resins can be used as receiving phase in passive samplers designed for the detection of lipophilic marine toxins at sea and was referred to as solid phase adsorption toxin tracking (SPATT). The present study describes the uptake and desorption behaviour of the lipophilic marine toxins okadaic acid (OA) and dinophysistoxin-1 (DTX1) from Prorocentrum lima cultures by five styrene-divinylbenzene based polymeric resins Sepabeads (R) SP850, Sepabeads (R) SP825L, Amberlite (R) XAD4, Dowex (R) Optipore (R) L-493 and Diaion (R) HP-20. All resins accumulated OA and DTX1 from the P. lima culture with differences in adsorption rate and equilibrium rate. Following statistical evaluation, HP-20, SP850 and SP825L demonstrated... |
| Tipo: Text |
Palavras-chave: Polymeric resin; Dinophysistoxin 1; Okadaic acid; SPATT; Prorocentrum lima. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4739.pdf |
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| Twiner, Michael J.; Rehmann, Nils; Hess, Philipp; Doucette, Gregory J.. |
| Azaspiracids (AZA) are polyether marine toxins that accumulate in various shellfish species and have been associated with severe gastrointestinal human intoxications since 1995. This toxin class has since been reported from several countries, including Morocco and much of western Europe. A regulatory limit of 160 mu g AZA/kg whole shellfish flesh was established by the EU in order to protect human health; however, in some cases, AZA concentrations far exceed the action level. Herein we discuss recent advances on the chemistry of various AZA analogs, review the ecology of AZAs, including the putative progenitor algal species, collectively interpret the in vitro and in vivo data on the toxicology of AZAs relating to human health issues, and outline the... |
| Tipo: Text |
Palavras-chave: Azaspiracid (AZA); AZP; Shellfish poisoning. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00077/18805/16375.pdf |
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| Jauffrais, Thierry; Sechet, Veronique; Herrenknecht, Christine; Tillmann, Urban; Krock, Bernd; Amzil, Zouher; Hess, Philipp. |
| Azaspiracids are lipophilic marine biotoxins causing gastrointestinal symptoms similar to DSP toxins. Since 1995, azaspiracids have been encountered in Europe, Africa and more recently in North and South America and Japan. The biological primary producer remained undiscovered during many years and has now been identified as Azadinium spinosum. The organism was grown using K modified medium, at 18°C with a PFD of 200 μmol.m-2.s-1 and a photoperiod of 16L/8D. Batch cultures were carried out using 75mL and 10L flasks, while continuous cultures were produced in 100L chemostats. Cells were recovered using centrifugation or filtration. Different extraction solvents and procedures as well as evaporation modes were evaluated for yield. Quantitation was carried out... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00152/26348/24431.pdf |
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| Hess, Philipp. |
| Toxic algae producing an array of bioactive compounds may accumulate in shellfish, which in turn cause poisoning, following human consumption of contaminated shellfish. The chemistry, occurrence and toxicity of the toxins involved was reviewed. Following this review, the risk analysis and management processes are outlined for the production of shellfish. Subsequent sections describe five elements of risk characterisation to which my studies have significantly contributed: methods of analysis, distribution of toxins in the marine environment, preparative isolation of toxins, quality control tools in the determination of the toxins and characterisation of the chemical hazard in terms of lipophilicity, stability, reactivity and toxicity. The use of liquid... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00015/12661/9548.pdf |
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| Hess, Philipp. |
| An overview is given of the biological origin of phycotoxins, as well as their chemical characteristics. Major poisoning types are described and examples of poisoning events are given to illustrate the importance of the phenomenon to both shellfish consumers and the shellfish producing industry. The characteristics of phycotoxins as natural products, the lack of predictability of their occurrence, economic drivers and the freshness of shellfish consumed in many countries result in a number of requirements for methods to be used in the efficient detection of these compounds. Subsequently, the performance of mouse bioassays and mass spectrometry as detection tools are compared for examples from Irish and French monitoring programmes to assess the usefulness... |
| Tipo: Text |
Palavras-chave: Bioanalytical methods; Bioassays; Mass spectrometry; Liquid chromatography; Biological samples. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00006/11767/8989.pdf |
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| Hess, Philipp; Nicolau, Elodie. |
| Over the past seven years, methods available for the detection of phycotoxins have been extensively reviewed in a number of international expert committees, such as the consultations organised by FAO/IOC/WHO and EFSA, as well as by individual scientists. These reviews have shown that the methods available have severe limitations for the use in official control, either due to their limited scope and detection capability or due to a lack of calibration standards, reference materials and validation efforts. The present review focuses on recent developments in the detection of phycotoxins in several areas of applied research. Not being able to exhaustively describe all recent developments, the review focussed on three areas of interest to the authors: (i)... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00019/12975/9949.pdf |
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| Tong, Mengmeng; Kulis, David M.; Fux, Elie; Smith, Juliette L.; Hess, Philipp; Zhou, Qixing; Anderson, Donald M.. |
| 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... |
| Tipo: Text |
Palavras-chave: Diarrhetic shellfish poisoning (DSP); Dinophysis acuminata; Dinophysistoxin (DTX); Growth phase; Light; Okadaic acid (OA); Pectenotoxins (PTXs). |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00037/14827/12195.pdf |
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| Mccarron, Pearse; Emteborg, Hakan; Nulty, Ciara; Rundberget, Thomas; Loader, Jared I.; Teipel, Katharina; Miles, Christopher O.; Quilliam, Michael A.; Hess, Philipp. |
| The development of multi-analyte methods for lipophilic shellfish toxins based on liquid chromatography-mass spectrometry permits rapid screening and analysis of samples for a wide variety of toxins in a single run. Validated methods and appropriate certified reference materials (CRMs) are required to ensure accuracy of results. CRMs are essential for accurate instrument calibration, for assessing the complete analytical method from sample extraction to data analysis and for verifying trueness. However, CRMs have hitherto only been available for single toxin groups. Production of a CRM containing six major toxin groups was achieved through an international collaboration. Preparation of this material, CRM-FDMT1, drew on information from earlier studies as... |
| Tipo: Text |
Palavras-chave: CRM-FDMT1; Certified reference material; Shellfish toxins; Phycotoxins; Accuracy; Precision; Liquid chromatography-mass spectrometry. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00037/14826/12237.pdf |
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| Aasen, John A. B.; Espenes, Arild; Miles, Christopher O.; Samdal, Ingunn A.; Hess, Philipp; Aune, Tore. |
| For many years, the presence of yessotoxins (YTXs) in shellfish has contributed to the outcome of the traditional mouse bioassay and has on many occasions caused closure of shellfisheries. Since YTXs do not appear to cause diarrhoea in man and exert low oral toxicity in animal experiments, it has been suggested that they should be removed from regulation. Before doing so, it is important to determine whether the oral toxicity of YTXs is enhanced when present together with shellfish toxins known to cause damage to the gastrointestinal tract. Consequently, mice were given high doses of YTX, at 1 or 5 mg/kg body weight, either alone or together with azaspiracid-1 (AZA1) at 200 μg/kg. The latter has been shown to induce damage to the small intestine at this... |
| Tipo: Text |
Palavras-chave: Azaspiracid-1; AZA1; Yessotoxin; YTX; Marine algal toxins; Absorption; Pathology; Sublethal; NMRI; Mice; LC-MS/MS; Oral toxicity. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00034/14477/11776.pdf |
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| Salas, Rafael; Tillmann, Urban; John, Uwe; Kilcoyne, Jane; Burson, Amanda; Cantwell, Caoimhe; Hess, Philipp; Jauffrais, Thierry; Silke, Joe. |
| Azaspiracids (AZAs) are a group of lipophilic polyether compounds first detected in Ireland which have been implicated in shellfish poisoning incidents around Europe. These toxins regularly effect shellfish mariculture operations including protracted closures of shellfish harvesting areas for human consumption. The armoured dinoflagellate Azadinium spinosum Elbrachter et Tillmann gen. et sp. nov. (Dinophyceae) has been described as the de novo azaspiracid toxin producer; nonetheless the link between this organism and AZA toxin accumulation in shellfish has not yet been established. In August 2009, shellfish samples of blue mussel (Mytilus edulis) from the Southwest of Ireland were analysed using liquid chromatography-tandem-mass spectrometry (LC-MS/MS) and... |
| Tipo: Text |
Palavras-chave: Azaspiracids; AZP; AZA toxins; Biodeposits; Dinoflagellates; Feeding experiment; Ireland; LC-MS/MS; Mussels; Phylogeny; Taxonomy. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00049/16049/15836.pdf |
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| Jauffrais, Thierry; Kilcoyne, Jane; Sechet, Veronique; Herrenknecht, Christine; Truquet, Philippe; Herve, Fabienne; Berard, Jean-baptiste; Nulty, Ciara; Taylor, Sarah; Tillmann, Urban; Miles, Christopher O.; Hess, Philipp. |
| Azaspiracid (AZA) poisoning has been reported following consumption of contaminated shellfish, and is of human health concern. Hence, it is important to have sustainable amounts of the causative toxins available for toxicological studies and for instrument calibration in monitoring programs, without having to rely on natural toxin events. Continuous pilot scale culturing was carried out to evaluate the feasibility of AZA production using Azadinium spinosum cultures. Algae were harvested using tangential flow filtration or continuous centrifugation. AZAs were extracted using solid phase extraction (SPE) procedures, and subsequently purified. When coupling two stirred photobioreactors in series, cell concentrations reached 190,000 and 210,000 cell·mL−1 at... |
| Tipo: Text |
Palavras-chave: Solid phase extraction; Photobioreactor; Chemostat; Dinoflagellate; Micro-algae; LC-MS/MS; Tangential flow filtration; Azaspiracid; HP-20. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00088/19875/17526.pdf |
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| Mondeguer, Florence; Antignac, Jean-philippe; Guitton, Yann; Monteau, Fabrice; Le Borgne, Sabrina; Hess, Philipp. |
| 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,... |
| Tipo: Text |
Palavras-chave: Métabolomique; LC-HRMS; Biotoxines marines; Biomarqueur. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00077/18784/16352.pdf |
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| Jauffrais, Thierry; Contreras, Andrea; Herrenknecht, Christine; Truquet, Philippe; Sechet, Veronique; Tillmann, Urban; Hess, Philipp. |
| Azadinium spinosum, a small toxic dinoflagellate, was recently isolated and identified as a primary producer of azaspiracid toxins (AZAs). Previous experiments related to AZA accumulation in blue mussels upon direct feeding with A. spinosum revealed increased mussel mortality and had negative effects on the thickness of the digestive gland tubules. Therefore we conducted follow up experiments in order to study effects of A. spinosum on mussel feeding behaviour. Individual assessment of mussel feeding time activity (FTA), clearance rate (CR), filtration rate (TFR), absorption rate (AR), faeces and pseudofaeces production were carried out on mussel fed either toxic (A. spinosum) or non-toxic (Isochrisis aff. galbana (T-Iso)) diets. Furthermore, AZA... |
| Tipo: Text |
Palavras-chave: Bivalve molluscs; Mussel; Ecophysiology; AZA biotransformation; AZA accumulation; Trophic transfer; Dinoflagellate; Azaspiracid. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00090/20174/17832.pdf |
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| Hess, Philipp; Herve, Fabienne; Abadie, Eric; Sechet, Veronique; Molgo, Jordi; Amzil, Zouher; Fessard, Valerie. |
| Suite à la découverte de la Pinnatoxine G comme agent responsable des toxicités atypiques à Ingril fin 2010, une étude a été commanditée afin d’approfondir les connaissances sur l’organisme producteur de cette toxine, Vulcanodinium rugosum, les toxines associées et leur toxicité. L’organisme, étant considéré « cryptique » dû à sa faible présence dans le milieu, a été suivi de manière plus proche à Ingril. Il est apparu dans la colonne d’eau en juillet et août 2012, et quelques échantillons ont pu être prélevés pour la mise en culture de souches supplémentaires. Une corrélation directe entre la croissance de l’organisme et la température est soupçonnée mais n’a pas encore pu être corroborée sur la période d’étude, faute d’un nombre suffisant... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00094/20518/18190.pdf |
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| Jauffrais, Thierry; Herrenknecht, Christine; Sechet, Veronique; Sibat, Manoella; Tillmann, Urban; Krock, Bernd; Kilcoyne, Jane; Miles, Christopher O.; Mccarron, Pearse; Amzil, Zouher; Hess, Philipp. |
| Azaspiracids (AZAs) are secondary metabolites of Azadinium spinosum, that have been shown to cause diarrhetic shellfish poisoning when accumulated in bivalve molluscs. We describe here an analytical procedure for the determination of AZAs in cultures of A. spinosum with a focus on the potential formation of AZA methyl-esters as artefacts in the extraction and sample pre-treatment. A. spinosum cells were collected from bioreactor cultures, using centrifugation or filtration. Different extraction procedures were evaluated for formation of methyl-ester artefacts, yield, and matrix effects. Filtration of cultures using glass-fibre filters led to increased formation of methyl-esters. Hence centrifugation is recommended for recovery of cells. The type of... |
| Tipo: Text |
Palavras-chave: Extraction procedure; Extraction artefact; Matrix effects; LC-MS/MS; Azaspiracid methyl ester; Dinoflagellate; Liquid chromatography-mass spectrometry. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00077/18812/16463.pdf |
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| Jauffrais, Thierry; Marcaillou-le Baut, Claire; Herrenknecht, Christine; Truquet, Philippe; Sechet, Veronique; Nicolau, Elodie; Tillmann, Urban; Hess, Philipp. |
| Azadinium spinosum (Elbrächter and Tillmann), a small marine dinoflagellate, has been recently described as a de novo producer of azaspiracid-1 and -2 (AZA1 and -2) diarrhoeic toxins. A culture of A. spinosum was established in our laboratory and optimised for pilot-scale production of this organism, to evaluate and understand AZA1 and -2 accumulation and biotransformation in blue mussels (Mytilus edulis) fed with A. spinosum. Adult mussels were continuously exposed to A. spinosum over 1 week in 160 L cylindrical conical tanks. Three different diets were tested for contamination: 5000, 10 000 cells mL−1 of A. spinosum and a mixture of 5000 cells mL−1 of A. spinosum with 5000 cells mL−1 of Isochrysis aff. galbana (T-Iso, CCAP 927/14). During the subsequent... |
| Tipo: Text |
Palavras-chave: Azaspiracid; Azadinium spinosum; Marine biotoxins; AZA; Tissue distribution; Histology; Bivalve molluscs; Liquid chromatography coupled to tandem mass spectrometry. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00088/19877/17566.pdf |
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| Jauffrais, Thierry; Sechet, Veronique; Herrenknecht, Christine; Truquet, Philippe; Savar, Veronique; Tillmann, Urban; Hess, Philipp. |
| Azadinium spinosum, a small dinoflagellate isolated from the North Sea, is a producer of azaspiracids (AZAs), a group of biotoxins associated with human illness following ingestion of contaminated shellfish. Using batch and continuous cultures of A. spinosum, the present study investigated the effects of different environmental and nutritional factors (salinity, temperature, photon flux density, aeration, culture media, nitrogen sources, phosphate source, and N/P ratios) on growth, maximum cell concentration, and AZA cell quota. Azadinium spinosum grew in a wide range of conditions; from 10 ̊C to 26 ̊C and salinities from 30 to 40, under irradiances ranging from 50 μmol m−2 s−1 to 250 μmol m−2 s−1, with or without aeration. Growth and maximum cell... |
| Tipo: Text |
Palavras-chave: AZA; Chemostat; Dinophyceae; Nutrients; N/P ratio; Photobioreactor. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00149/26054/24411.pdf |
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| Geiger, Marie; Desanglois, Gwenaelle; Hogeveen, Kevin; Fessard, Valerie; Lepretre, Thomas; Mondeguer, Florence; Guitton, Yann; Herve, Fabienne; Sechet, Veronique; Grovel, Olivier; Pouchus, Yves-francois; Hess, Philipp. |
| Pinnatoxin G (PnTX-G) is a marine toxin belonging to the class of cyclic imines and produced by the dinoflagellate Vulcanodinium rugosum. In spite of its strong toxicity to mice, leading to the classification of pinnatoxins into the class of “fast-acting toxins”, its hazard for human health has never been demonstrated. In this study, crude extracts of V. rugosum exhibited significant cytotoxicity against Neuro2A and KB cells. IC50 values of 0.38 µg mL−1 and 0.19 µg mL−1 were estimated on Neuro2A cells after only 24 h of incubation and on KB cells after 72 h of incubation, respectively. In the case of Caco-2 cells 48 h after exposure, the crude extract of V. rugosum induced cell cycle arrest accompanied by a dramatic increase in double strand DNA breaks,... |
| Tipo: Text |
Palavras-chave: Dereplication; Cyclic imine; HRMS; Bioactivity; Pinnatoxins. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00156/26723/24802.pdf |
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| Jauffrais, Thierry; Kilcoyne, Jane; Herrenknecht, Christine; Truquet, Philippe; Sechet, Veronique; Miles, Christopher O.; Hess, Philipp. |
| The relationship between azaspiracid shellfish poisoning and a small dinoflagellate, Azadinium spinosum, has been shown recently. The organism produces AZA1 and -2, while AZA3 and other analogues are metabolic products formed in shellfish. We evaluated whether mussels were capable of accumulating dissolved AZA1 and -2, and compared the toxin profiles of these mussels at 24 h with profiles of those exposed to live or lysed A. spinosum. We also assessed the possibility of preparative production of AZA metabolites by exposing mussels to semi-purified AZA1. We exposed mussels to similar concentration of AZAs: dissolved AZA1+2 (crude extract) at 7.5 and 0.75 µg L-1, dissolved AZA1+2 (7.5 µg L-1) in combination with Isochrysis affinis galbana, and lysed and live... |
| Tipo: Text |
Palavras-chave: Dissolved marine biotoxins; AZA; Tissue distribution; Bivalve molluscs; LC-MS/MS; Azaspiracid. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00136/24757/22867.pdf |
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| Registros recuperados: 91 | |
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