Toxic cyanobacteria strains isolated from blooms in the Guadiana River (southwestern Spain)

This paper describes the occurrence of toxic cyanobacteria along the Guadiana River over its course between Mérida and Badajoz (Extremadura, Spain). Water sampling for phytoplankton quantification and toxin analysis was carried out regularly between 1999 and 2001 in six different locations, including two shallow, slow-flowing river sites, two streamed river sites and two drinking water reservoirs. The cyanobacterial community differed significantly between these locations, especially during the summer. The predominant genera were Microcystis, Oscillatoria, Aphanizomenon and Anabaena. Using an ELISA assay the total microcystin contents of natural water samples from the most eutrophic locations ranged from 0.10 – 21.86 µg mcyst-LR equivalent·L-1 in Valdelacalzada and 0.10-11.3 µg mcyst-LR equivalent·L-1 in Vitonogales, and a seasonal variation of toxin content was observed. The amount of microcystins produced by each strain was determined by ELISA assay and the detection and identification of microcystin variants of three toxic strains of Microcystis aeruginosa was performed by high performance liquid chromatography (HPLC). The analysis of microcystins of the cultured strains revealed that toxin production was variable among different strains of M. aeruginosa isolated either from different blooms or from the same bloom.Junta de Andalucía (CTS358

Comparison of Microcystis aeruginosa (PCC7820 and PCC7806) growth and intracellular microcystins content determined by liquid chromatography–mass spectrometry, enzyme-linked immunosorbent assay anti-Adda and phosphatase bioassay

Cyanobacteria are able to produce several metabolites that have toxic effects on humans and animals. Among these cyanotoxins, the hepatotoxic microcystins (MC) occur frequently. The intracellular MC content produced by two strains of Microcystis aeruginosa, PCC7806 and PCC7820, and its production kinetics during the culture time were studied in order to elucidate the conditions that favour the growth and proliferation of these toxic strains. Intracellular MC concentrations measured by liquid chromatography (LC) coupled to electrospray ionization mass spectrometer (MS) were compared with those obtained by enzyme-linked immunosorbent assay (ELISA) anti-Adda and protein phosphatase 2A (PP2A) inhibition assays. It has been demonstrated there are discrepancies in the quantification of MC content when comparing ELISA and LC-MS results. However, a good correlation has been obtained between PP2A inhibition assay and LC-MS. Three MC were identified using LC-MS in the PCC7806 strain: MC-LR, demethylated MC-LR and a new variant detected for the first time in this strain, [MeSer7] MC-LR. In PCC7820, MC-LR, D-Asp3-MCLR, Dglu(OCH3)-MCLR, MC-LY, MC-LW and MC-LF were identificated. The major one was MC-LR in both strains, representing 81 and 79% of total MC, respectively. The total MC content in M. aeruginosa PCC7820 was almost three-fold higher than in PCC7806 extracts.Centro de Investigaciones Cietíficas y Técnicas AGL 2006–06523/ AL

Toxicological interest of Microcystins

Las Microcistinas (MCs) son toxinas de estructura heptapeptídica producidas por floraciones de cianobacterias tóxicas de aguas superficiales eutróficas. Las MCs al igual que la nodularina son hepatotóxicas en humanos, aunque también dan lugar a alteraciones gastrointestinales, reacciones alérgicas o irritación y sintomatología similar a la neumonía. El principal riesgo tóxico deriva de su actividad promotora tumoral, y capacidad genotóxica. Diversos estudios epidemiológicos sugieren una mayor incidencia de cáncer de hígado en zonas cuya población está expuesta de forma prolongada a MCs, por consumo de aguas de bebida contaminadas, advirtiéndose la necesidad de conocer otras posibles fuentes de exposición humana, tales como alimentos. La Organización Mundial de la Salud ha adoptado (WHO, 1998) un valor guía provisional de 1,0 μg/L de MCLR en aguas de bebida, comprendiendo tanto las MCs intra como las extracelulares. En la Reglamentación técnico-sanitaria vigente en España para el abastecimiento y control de la calidad de las aguas potables de consumo público (RD 1138/1990 de 14 de Septiembre) no se hace referencia a la determinación y control de MCs; sin embargo en el nuevo proyecto de reglamentación, anexo D, que hace referencia a las sustancias tóxicas, se fija una concentración máxima admisible de MCs de 1 μg/L en el caso de aguas eutróficas. En esta revisión se consideran los efectos tóxicos agudos, crónicos y el mecanismo de acción de las Microcistinas.Microcystins (MCs) are toxins of heptapeptidic structure produced by the bloom of toxic cyanobacteria in surface eutrophic waters. MCs, just like nodularine, are hepatotoxic in humans, but they also cause gastrointestinal alterations, allergic reactions, irritation and neumonia-like symptomatology. The main toxic risk derives from their tumor-promoting activity and genotoxic capacities. Several epidemiological studies suggest an increased incidence of liver cancer in populations chronically exposed to MCs. The main source is contaminated drinking water, but other sources of human exposure, such as food, should be investigated. The World Health Organization adopted (WHO, 1998) a provisional guide value of 1,0 μg/L of MC-LR in drinking water, including intra- and extracellular MCs. In the present Spanish legislation regarding quality control of drinking water (RD 1138/1990 of 14 September), the determination and control of MCs are not included; however, in the draft of the new legislation, annex D, concerning toxic chemicals, a maximum tolerable concentration of 1 μg/L is fixed for MCs in eutrophic waters. Acute and chronic effects and the mechanism of action of MCs are considered in this review

Interés de la elaboración de vídeos didácticos como material de prácticas en la asignatura de "Seguridad Química"

El presente trabajo tiene por objeto presentar el proceso seguido en la elaboración de una serie videográfica constituida por tres videos didácticos, que abordan los aspectos fundamentales de los riesgos derivados de la exposición a sustancias químicas y agentes biológicos en un labo - ratorio universitario. dicho material didáctico innovador, se utilizará en los seminarios teóricos de la asignatura seguridad Química, impartida por los profesores del área de toxicología de la universidad de sevilla. los objetivos fundamentales de dichos videos han sido despertar el mayor interés posible y favorecer la asimilación de conceptos básicos en el alumnado de dicha asignatura, haciendo especial hincapié en la correcta y segura manipulación, el adecuado almacenamiento y la correcta eliminación de las sustancias, contribuyendo en definitiva a la prevención de los riesgos derivados de su exposición.The present work aims to illustrate the process followed to elaborate a set of three didactic illustrate the process followed to elaborate a set of three didactic videos, which shows the main aspects of derived risks from the exposure to the chemical substances and biological agents present in a university laboratory. this innovator didactic material will be used in the subject “chemical security” seminaries lectured by the professors from toxicology area in the university of seville. the most important aims of these videos have been to implicate the students in their learning, making easier for them to assimilate the basic concepts of the subject, such as the correct and secure way of manipulate the chemical substances, its appropriate storage and its suitable elimination, contributing to the prevention of the risks derived from their exposure

Insecticide Reproductive Toxicity Profile: Organophosphate, Carbamate and Pyrethroids

Exposure to pesticides is very common world-wide, and is broadly known the acute toxic effects to humans of pesticides following a high dose exposure; however, knowledge about chronic low-dose adverse effects to specific pesticides is more limited. Reproductive functions can be affected, with birth defects, impaired fecund ability, infertility and altered growth. This paper will focus on the deleterious effects that may appear in the offspring, during early and later stages of life, after prenatal exposure to insecticides, not only on women with direct exposure but also on subjects with indirect exposure such as consumers or residents of rural communities. Prenatal exposure to pesticides could alter normal fetal development and could threaten future welfare. The main changes observed in prenatal exposure to organophosphates are alterations in the central nervous system, in the metabolic and hormonal system as endocrine disruptor and over the birth outcomes. Carbamates may cause developmental delay when the applications of carbamates during pregnancy were nearby the home. Pyrethroids are among the most frequently used pesticides and account for more than one-third of the insecticides currently marketed in the world. For this reason the prenatal exposition used to be for long periods causing clinical, biochemical and neurological changes

Metalistería y numismática del Turro (Cacín) en los siglos VIII al XI

El trabajo está confeccionado con materiales arqueológicos de una colección particular. Son de la cortijada del Turro (Cacín, Granada) cerca de unas ruinas donde se localizó sigillata y otros materiales. Los materiales que estudiamos son del pasaje de las Higuerillas con un total de 7 piezas: dos anillos de cobre, un fragmento de despabiladera de candil y espátula, una punta de flecha, un broche, una tapadera y un resto amorfo. Además se aporta un lote de monedas andalusíes de los siglos VIII al XI. El trabajo es interesante por las noticias que aportan y por completar otros aspectos de la alta Edad Media en las tierras granadinas.The author examines archeological pieces which form part of a prívate collection, that of the "Turro" hacienda in Cacín, Granada, situated near sorne ruins wher sigilleta· and other materials have been found. The pieces studied (a total of 7) come from the Higuerillas path: two copper rings, a fragment of a lamp-snuff or spatula, an arrow-tip, a broach, a lid and a shapeless ítem. A collection of andalusi coin s from the 8th to the 1 1t h century is also described. The study is of interest, since it provides data which help to illuminate aspects of the Late Middle Ages in the Granada area

Development of a New Method for the Determination of Manganese, Cadmium, Mercury and Lead in Whole Blood and Amniotic Fluid by Inductively Coupled Plasma Mass Spectrometry

Environmental exposure to metals among women, revealed their adverse effects on pregnancy. During this stage, blood levels of some metals increase so research on heavy metals transference from the mother’s blood to the developing foetus is of special interest and much attention has been paid to this matter. The amniotic fluid can be considered as a valuable marker of this prenatal exposure to exogenous factors. The aim of this study was to develop a method for the simultaneous determination of Mn, Cd, Hg, and Pb in whole maternal blood and amniotic fluid by ICP-MS. Strategies were given to minimise memory effects related to mercury and two widespread digestion procedures (open-vessel and microwave-assisted) were compared. Several quality controls, such as methodological and reagent blanks, spiked samples and duplicates were used to test the goodness of the developed method. Once optimised, the method was applied for the monitoring of Mn, Cd, Hg and Pb in 15 maternal blood and amniotic fluid samples obtained at delivery after informed consent. This study establishes that heavy metals pass into and accumulate in amniotic fluid and maternal blood. Thus, mean concentrations of Mn were similar in the two biological fluids studied, 21.6 ng/mL in maternal blood and 20.5 ng/mL in amniotic fluid. Mean Cd and mercury levels in blood and amniotic fluid were 1.3 and 6.3 ng/mL and 3.4 and 3.8 ng/mL, respectively. Concentrations of Pb were 16.4 ng/mL in blood and 13.7 ng/mL in amniotic fluid. Further studies are needed to evaluate the long-term health effects derived from this exposure.Plan Propio of the University of SevilleFundación Farmacéutica Avenzoa

Alteration of oxidative stress biomarkers in Tilapia (Oreochromis niloticus) exposed to repeated doses of Cylindrospermopsin by different exposure routes

Ejemplar dedicado a: Monográfico sobre Seguridad Alimentaria: Las cianobacterias tienen capacidad de sintetizar una gran variedad de metabolitos secundarios, identificándose entre ellos la Cilindrospermopsina (CYN), toxina principalmente citotóxica. En general, la exposición a esta molécula se caracteriza por una toxicidad tardía sobre múltiples órganos, principalmente hígado y riñón. Se han sugerido varios mecanismos de acción tóxica: inhibición de la síntesis de proteínas y de glutatión y más recientemente el estrés oxidativo. El objetivo del presente estudio fue investigar la influencia del tiempo y de la vía de exposición sobre la inducción de estrés oxidativo como mecanismo de acción tóxica asociado a la patogenicidad de CYN, en pescados de consumo público, Tilapias (Oreochromis niloticus), expuestos a dosis repetidas de la toxina mediante inmersión en biomasa de Aphanizomenon ovalisporum o por vía oral con células liofilizadas de A. ovalisporum durante tres períodos de 7, 14 y 21 días. Los biomarcadores ensayados en hígado y riñón de los peces fueron: peroxidación lipídica, oxidación de proteínas, oxidación del ADN, las actividades glutatión-Stransferasa, glutatión peroxidasa, superóxido dismutasa, catalasa γglutamilcisteín sintetasa, y la relación glutatión reducido y oxidado (GSH/GSSG). Se observó una inducción de estrés oxidativo en hígado y riñón de las tilapias expuestas a dosis repetidas de CYN, manifestado por una alteración en los niveles de peroxidación lipídica, oxidación de proteínas y de ADN, así como en las actividades de las enzimas antioxidantes estudiadas y en los niveles de glutation a lo largo de los tres períodos de exposición. En general, las alteraciones más significativas se observaron en tilapias expuestas a CYN por inmersión en biomasa de A. ovalisporum durante un periodo de 21 días, demostrándose así que estos efectos se ven influenciados por la vía y el tiempo de exposición.Cyanobacteria are able to synthesize a large variety of secondary metabolites, including Cylindrospermopsin (CYN), a mainly cytotoxic toxin. In general, exposure to this molecule is characterized by late toxicity on multiple organs, mainly liver and kidney. Several mechanisms of action have been suggested; as inhibition of protein and glutathione synthesis and more recently oxidative stress. The aim of this study was to investigate the influence of time and route of exposure on the induction of oxidative stress as a mechanism of toxic action associated with CYN pathogenicity in public-consumed fish exposed to repeated doses of CYN by immersion, containing a culture of A. ovalisporum or orally with lyophilized cells of Aphanizomenon ovalisporum for three periods of exposure: 7, 14 and 21 days. Fish biomarkers tested in liver and kidney were: lipid peroxidation, protein oxidation, DNA oxidation, activities glutathione-Stransferase, glutathione peroxidase, superoxide dismutase, catalase, γ-glutamylcysteine synthetase, and glutathione reduced/glutathione oxidized ratio. An induction of oxidative stress was observed in liver and kidney of tilapia fishes exposed to repeated doses of CYN. Alterations in lipid peroxidation levels, protein and DNA oxidation process, as well as in the activity of the studied antioxidant enzymes and glutathione levels for all three periods of exposure tested, were observed. In general, the most significant changes were observed in tilapias exposed to CYN by immersion in a CYN-containing culture of A. ovalisporum over 21 days, thus demonstrates that these effects are influenced by the route and time of exposure.Ministerio de Ciencia e Innovación (España) AGL2009-10026ALIJunta de Andalucía (España) P09-AGR-467