The toxicity and intraspecific variability of Alexandrium andersonii Balech

The toxicity of Alexandrium andersonii Balech is unclear and its intraspecific variability has yet to be studied. To address these gaps in our knowledge, in the present work five strains of A. andersonii from four different localities were characterized. The results showed that despite genetic homogeneity in the 5.8-ITS (internal transcribed spacer) and large subunit (LSU) regions and similar growth rates, strains originating from different locations varied with respect to cell size, the ratios of certain pigments, and their growth patterns. Cultures of the strains grown at 20 8C were analyzed for toxicity using four different methodologies. The two officially established methods, mouse bioassay and high-performance liquid chromatography with fluorescence detection (HPLC-FLD) and post-column reaction analysis of PSP toxins, failed to show the toxicity of any strain. Strains grown at 14 8C were also negative for PSP toxins by HPLC-FLD. However, strains grown at 20 8C exhibited both a response characteristic of the presence of toxin-inhibiting voltage-gated sodium channels, as demonstrated in a neuroblastoma neuro- 2a cell-based assay, as well as hemolytic activity in a sheep red blood cell assay

Predictive score and probability of CTX-like toxicity in fish samples from the official control of ciguatera in the Canary Islands

This research identifies factors associated with the contamination by ciguatoxins (CTXs) in a population of fish and proposes a predictive score of the presence of CTX-like toxicity in amberjack samples from the official control program of ciguatera in the Canary Islands of the Directorate-General (DG) Fisheries (Canary Government). Out of the 970 samples of fish studied, 177 (18.2%) samples showed CTX-like toxicity. The fish were classified according to the species, amberjack (Seriola dumerili and S. rivoliana) (n = 793), dusky grouper (Epinephelus marginatus) (n = 145) and wahoo (Acanthocybium solandri) (n = 32). The data were separated by species category and statistically examined, resulting in 137 (17.3%) amberjack and 39 (26.9%) grouper samples showing CTX-like toxicity; regarding wahoo species, only 1 toxic sample (3.1%) was found. According to fishing location the contamination rates suggested grouping the islands in four clusters; namely: {El Hierro: HI; La Gomera: LG; La Palma: LP}, {Gran Canaria: GC; Tenerife: TF}, {Fuerteventura: FU} and {Lanzarote: LZ}. For the amberjack species, the multivariate logistic regression showed the factors that maintained independent association with the outcome, which were the warm season (OR = 3.617; 95% CI = 1.249–10.474), the weight (per kg, 1.102; 95% CI = 1.069–1.136) and the island of fish catching. A prediction score was obtained for the probability of contamination by CTX in amberjack fish samples. The area under de curve (AUC) obtained using the validation data was 0.747 (95% CI = 0.662–0.833). Regarding grouper species, the island of fishing was the only factor that showed significant differences associated with the presence of CTX-like toxicity. We provide herein data for a better management and prediction of ciguatera in the Canary Islands, suggesting a review of the minimum limits of fish weight established by the Canary Government for the control program.info:eu-repo/semantics/acceptedVersio

Ciguatoxin occurrence in food-web components of a Cuban Coral Reef Ecosystem: Risk-assessment implications

In Cuba, ciguatera poisoning associated with fish consumption is the most commonly occurring non-bacterial seafood-borne illness. Risk management through fish market regulation has existed in Cuba for decades and consists of bans on selected species above a certain weight; however, the actual occurrence of ciguatoxins (CTXs) in seafood has never been verified. From this food safety risk management perspective, a study site locally known to be at risk for ciguatera was selected. Analysis of the epiphytic dinoflagellate community identified the microalga Gambierdiscus. Gambierdiscus species included six of the seven species known to be present in Cuba (G. caribaeus, G. belizeanus, G. carpenteri, G. carolinianus, G. silvae, and F. ruetzleri). CTX-like activity in invertebrates, herbivorous and carnivorous fishes were analyzed with a radioligand receptor-binding assay and, for selected samples, with the N2A cell cytotoxicity assay. CTX activity was found in 80% of the organisms sampled, with toxin values ranging from 2 to 8 ng CTX3C equivalents g−1 tissue. Data analysis further confirmed CTXs trophic magnification. This study constitutes the first finding of CTX-like activity in marine organisms in Cuba and in herbivorous fish in the Caribbean. Elucidating the structure–activity relationship and toxicology of CTX from the Caribbean is needed before conclusions may be drawn about risk exposure in Cuba and the wider Caribbean.info:eu-repo/semantics/publishedVersio

Bioaccessibility of contaminants of emerging concern in raw and cooked commercial seafood species: insights for food safety risk assessment.

Autoria na publicação: FABIOLA FOGAÇA

A multifactorial approach including tumoural epidermal growth factor receptor, p53, thymidylate synthase and dihydropyrimidine dehydrogenase to predict treatment outcome in head and neck cancer patients receiving 5-fluorouracil

The prognostic value of tumoural epidermal growth factor receptor (EGFR), p53, thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) was analysed on 82 advanced head and neck cancer patients (71 men, 11 women; mean age 59). Induction treatment was cisplatin–5-FU ± folinic acid (61 patients, Chem group) or concomitant cisplatin–5-FU–radiotherapy (21 patients, RChem group). EGFR (binding assay), p53 protein (Sangtec immunoluminometric assay), TS and DPD activities (radioenzymatic assays) were measured on biopsies obtained at time of diagnosis. Significant positive correlation was demonstrated between p53 and EGFR. In the RChem group, p53 was higher in non-complete responders (median 1.03 ng mg−1) than in complete responders (median 0.08 ng mg−1) (P = 0.057). Univariate Cox analyses stratified on treatment group showed that specific survival (33 events) was significantly related to T staging, p53 taken as continuous or categorial (below vs over 0.80 ng mg−1) variable, and EGFR (below vs over 220 fmol mg−1); survival increased when EGFR and p53 were below thresholds. Multivariate stepwise analysis including T staging, EGFR and p53 revealed that T staging and EGFR were independent predictors of survival; relative risks were 3.68 for T staging and 2.65 for EGFR. Overall, EGFR remained an independent prognostic factor when response to treatment and T staging were considered in the multivariate analysis. © 1999 Cancer Research Campaig

Interrelación de laboratorios de control y laboratorios de investigación en España para la armonización de metodologías de determinación de toxinas paralizantes

XII Congreso Nacional de Agricultura, Madrid 24-26 de noviembre de 2009Marketing of cultured and harvested shellfish is linked to monitoring programs for granting food safety. Its complexity requires constant cooperation between research and monitoring laboratories in order to improve sampling and analysing performances, achieve legal requirements, etc. for increasing consumer’s health protection but not reducing producer’s benefits. The JACUMAR project «Comparison of methodologies for the evaluation of Paralytic Shellfish Poisoning (PSP) toxins in bivalves. Application for aquaculture in Spain» groups research and monitoring laboratories from Galicia, Andalucía and Cataluña. Efforts are focused on detection and quantification of PSP toxins, searching an analytical method able to fulfil technical and management requirementsEste proyecto está financiado por la Junta Asesora de Cultivos Marinos (JACUMAR), y los programas de control por los gobiernos autónomos de Galicia, Andalucía y CataluñaN

First approach towards the implementation of passive sampling adsorption devices for the identification of lipophilic toxins in the shellfish monitoring program in the coastal embayments of the Ebro Delta

Molluscan safety monitoring programs search for control systems able to give an estimation of the concentration levels of marine toxins present in water, which could represent a risk for the health of consumers of shellfish products. In this study a deployment of passive sampling devices consisting of resin filled sachets was carried out weekly during two years in Alfacs Bay, a coastal embayment of the Ebro Delta in the NW Mediterranean, Spain. Lipophilic marine toxin concentration profiles were obtained analyzing the content of the polymeric resins after extraction and analysis by liquid chromatography coupled to a quadrupole ion trap mass spectrometer