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Cystic echinococcosis is a zoonotic infection caused by the larval stage of the cestodeEchinococcus granulosus. Chemotherapy currently employs benzimidazoles; however, 40% of cases do not respond favorably. With regard to these difficulties, novel therapeutic tools are needed to optimize treatment in humans. The aim of this work was to explore thein vitroandin vivoeffects of tamoxifen (TAM) againstE. granulosus. In addition, possible mechanisms for the susceptibility of TAM are discussed in relation to calcium homeostasis, P-glycoprotein inhibition, and antagonist effects on a putative steroid receptor. After 24 h of treatment, TAM, at a low micromolar concentration range (10 to 50 μM), inhibited the survival ofE. granulosusprotoscoleces and metacestodes. Moreover, we demonstrated the chemotherapeutic and chemopreventive pharmacological effects of the drug. At a dose rate of 20 mg/kg of body weight, TAM induced protection against the infection in mice. In the clinical efficacy studies, a reduction in cyst weight was observed after the administration of 20 mg/kg in mice with cysts developed during 3 or 6 months, compared to that of those collected from control mice. Since the collateral effects of high TAM doses have been largely documented in clinical trials, the use of low doses of this drug as a short-term therapy may be a novel alternative approach for human cystic echinococcosis treatment.

Dinophysis spp. associated to detection of diarrheic shellfish toxins (DSTs) in mollusks and to human diarrhoetic disease episode (Buenos Aires Province, Argentina

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Since 2009 we have been registering the outbreak of an unknown side-gilled sea slug of the genus Pleurobranchaea in coastal waters of Argentina, southwestern Atlantic Ocean. Examination of both external macroscopic features and internal structures via electron microscopy did not allow us to conclusively identify the species. Nevertheless, since Argentinian specimens closely resemble Pleurobranchaea maculata (a species native from Australia and New Zealand known to contain a potent neurotoxin) we performed a bioassay in our specimens, which was positive for neurotoxins. The presence of this pleurobranch in Argentinian waters is of concern beyond the ecological effects of the outbreak of a marine predator and requires urgent attention. This work provides a guide to distinguish between this unidentified species and the sympatric cryptogenic Pleurobranchaea inconspicua, based on features that are readily observable in fresh and preserved specimens. We discuss the potential effects of this outbreak on local communities.

With the move away from use of mouse bioassay (MBA) to test bivalve mollusc shellfish for paralytic shellfish poisoning (PSP) toxins, countries around the world are having to adopt non-animal-based alternatives that fulfil ethical and legal requirements. Various assays have been developed which have been subjected to single-laboratory and multi-laboratory validation studies, gaining acceptance as official methods of analysis and approval for use in some countries as official control testing methods. The majority of validation studies conducted to date do not, however, incorporate shellfish species sourced from Latin America. Consequently, this study sought to investigate the performance of five alternative PSP testing methods together with the MBA, comparing the PSP toxin data generated both qualitatively and quantitatively. The methods included a receptor binding assay (RBA), two liquid chromatography with fluorescence detection (LC-FLD) methods including both pre-column and post-column oxidation, liquid chromatography with tandem mass spectrometry (LC-MS/MS) and a commercial lateral flow assay (LFA) from Scotia. A total of three hundred and forty-nine shellfish samples from Argentina, Mexico, Chile and Uruguay were assessed. For the majority of samples, qualitative results compared well between methods. Good statistical correlations were demonstrated between the majority of quantitative results, with a notably excellent correlation between the current EU reference method using pre-column oxidation LC-FLD and LC-MS/MS. The LFA showed great potential for qualitative determination of PSP toxins, although the findings of high numbers of false-positive results and two false negatives highlighted that some caution is still needed when interpreting results. This study demonstrated that effective replacement methods are available for countries that no longer wish to use the MBA, but highlighted the importance of comparing toxin data from the replacement method using local shellfish species of concern before implementing new methods in official control testing programs.

A partir de un monitoreo de microalgas toxígenas y toxinas en moluscos iniciado en 2008, llevado a cabo entre San Clemente del Tuyú y Mar Azul (Zona Norte) y en la Bahía Anegada (Zona Sur) de la Provincia de Buenos Aires fueron registrados cuatro brotes de toxicidad por toxina paralizante de moluscos (PSP) y ocho brotes por toxinas lipofílicas de moluscos (DSP/no determinadas). Los resultados obtenidos fueron empleados como herramienta técnica a partir dela cual la autoridad de aplicación (Dirección Provincial de Pesca del Ministerio de Asuntos Agrarios de la Provincia de Buenos Aires) fundó la decisión de imponer once vedas y una alerta sanitaria al consumo, extracción y comercialización de moluscos. Tres de los brotes por PSP se produjeron en la Zona Norte y la especie asociada fue Gymnodinium catenatum. El cuarto episodio se produjo en Puerto Quequén, durante un muestreo eventual, asociado a Alexandrium tamarense. En esta misma zona se produjeron tres de los eventos de toxicidad por DSP, y las especies asociadas fueron Dinophysis acuminata y D. caudata. Los restantes cinco episodios de toxicidad por toxinas lipofílicas ocurrieron en la Zona Sur, en una o más de las tres zonas clasificadas sanitariamente como A por SENASA, y ninguno pudo ser asociado a alguna de las especies toxígenas conocidas.