Pollen malformation and ploidy levels in Ranunculus grex parnassiifolius

Se presenta un estudio sobre la malformación polínica en Ranunculus grex parnassiifolius, un complejo poliploide cuya distribución va desde las montañas del noroeste de la Península Ibérica hasta la mayor parte de los macizos alpinos. El resultado más notable es la baja viabilidad de polen en las poblaciones tetraploides (85,27% de polen no viable) en comparación con las poblaciones diploides (17,72%); y se considera como una prueba de la existencia de procesos reproductivos parcialmente apomícticos

In Vitro Mutagenic and Genotoxic Assessment of a Mixture of the Cyanotoxins Microcystin-LR and Cylindrospermopsin

The co-occurrence of various cyanobacterial toxins can potentially induce toxic effects different than those observed for single cyanotoxins, as interaction phenomena cannot be discarded. Moreover, mixtures are a more probable exposure scenario. However, toxicological information on the topic is still scarce. Taking into account the important role of mutagenicity and genotoxicity in the risk evaluation framework, the objective of this study was to assess the mutagenic and genotoxic potential of mixtures of two of the most relevant cyanotoxins, Microcystin-LR (MC-LR) and Cylindrospermopsin (CYN), using the battery of in vitro tests recommended by the European Food Safety Authority (EFSA) for food contaminants. Mixtures of 1:10 CYN/MC-LR (CYN concentration in the range 0.04-2.5 µg/mL) were used to perform the bacterial reverse-mutation assay (Ames test) in Salmonella typhimurium, the mammalian cell micronucleus (MN) test and the mouse lymphoma thymidine-kinase assay (MLA) on L5178YTk± cells, while Caco-2 cells were used for the standard and enzyme-modified comet assays. The exposure periods ranged between 4 and 72 h depending on the assay. The genotoxicity of the mixture was observed only in the MN test with S9 metabolic fraction, similar to the results previously reported for CYN individually. These results indicate that cyanobacterial mixtures require a specific (geno)toxicity evaluation as their effects cannot be extrapolated from those of the individual cyanotoxins.España Ministerio de Economía y Competitividad AGL2015-64558-

La relación médico-paciente en el tratamiento de la diabetes tipo 1. Un estudio cualitativo

ObjetivosConocer las experiencias y las expectativas de pacientes con diabetes tipo 1 (DM1) y sus familiares sobre la relación que establecen con sus médicos y su influencia en la forma de afrontar la enfermedad y el tratamiento.DiseñoDiseño cualitativo a través de grupos focales realizado en 2001.EmplazamientoDistintos centros sanitarios de Granada y Sevilla.ParticipantesPacientes con DM1, familiars y/o cuidadores.MétodoMuestreo teórico con representación de los perfiles más característicos. Procedimiento de análisis cualitativo: asignación de códigos al texto, triangulación e interpretación de resultados.ResultadosLa relación médico-paciente influye decisivamente en la vivencia emocional de la enfermedad y en la manera en que los pacientes asumen el control. Los pacientes entrevistados aseguran que la relación con sus médicos está centrada en los signos y los síntomas de la enfermedad, y que el aspecto emocional se deja de lado. Es frecuente que los profesionales basen su comunicación en la reprimenda y en la amenaza. Los tratamientos se imponen más que se consensúan, y las posibilidades de participación en las decisiones clínicas son escasas. En consecuencia, los pacientes desarrollan estrategias para tomar sus propias decisiones sobre el tratamiento adaptándolo a su vida.ConclusionesDesean un modelo de relación con sus médicos en el que les escuchen, empaticen con su situación, comprendan los problemas que enfrentan para seguir el tratamiento, les transmitan ánimos y adapten sus recomendaciones a las circunstancias vitales y emocionales de cada paciente. Se prefiere a los profesionales que combinan la competencia técnica (incluida la dimensión relacional) con la humanidad y la amabilidad, y que asumen su corresponsabilidad en el éxito del tratamiento.ObjectivesTo know the experiences and expectations of diabetes mellitus type 1 (DM1) patients and their relatives as regards the relationships established with doctors, and the impact of such relationships on their strategies to cope with the disease and treatment.DesignQualitative design based on focus groups conducted in 2001.LocationSeveral health care centres in Granada and Seville, Spain.ParticipantsDM1 patients and their relatives and/or carers.MethodTheory-based sampling including the most representative profiles. Qualitative analysis procedure: text coding, triangulation and interpretation of results.ResultsDoctor/patient relationship highly influences the emotional experience of disease and the way patients gain control over it. Interviewed patients said that the relationship with doctors is focused on disease signs and symptoms, leaving emotional aspects aside. Very often, provider communication is built on recrimination and threat. Treatment is imposed rather than agreed, with scarce opportunities for participating in clinical decisions. Patients develop strategies to take their own decisions and adapting treatment to their daily life.ConclusionsPatients value a relationship model whereby providers listen and empathise with their situation, understand their difficulties in treatment compliance, encourage them, and adapt recommendations to the personal and emotional circumstances of each patient. They prefer doctors combining professional competence-including relational skills-with humanity and kindness, as well as being capable of assuming their co-responsibility in treatment success

The role of sulfate groups in controlling CaCO3 polymorphism

The nucleation and growth of CaCO3 phases from aqueous solutions with SO4 2-:CO3 2- ratios from 0 to 1.62 and a pH ∼ 10.9 were studied experimentally in batch reactors at 25 ºC. The mineralogy, morphology and composition of the precipitates were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and microanalyses. The solids recovered after short reaction times (5 min to 1 h) consisted of a mixture of calcite and vaterite, with a S content that linearly correlates with the SO4 2-:CO32- ratio in the aqueous solution. The solvent-mediated transformation of vaterite to calcite subsequently occurred. After 24 h of equilibration, calcite was the only phase present in the precipitate for aqueous solutions with SO4 2-:CO3 2- ≤ 1. For SO4 2-:CO3 2- > 1, vaterite persisted as a major phase for a longer time (>250 h for SO4 2-:CO3 2- = 1.62). To study the role of sulfate in stabilizing vaterite, we performed a molecular simulation of the substitution of sulfate for carbonate groups into the crystal structure of vaterite, aragonite and calcite. The results obtained show that the incorporation of small amounts (<3 mole%) of sulfate is energetically favorable in the vaterite structure, unfavorable in calcite and very unfavorable in aragonite. The computer modeling provided thermodynamic information, which, combined with kinetic arguments, allowed us to put forward a plausible explanation for the observed crystallization behavior

Crecimiento de cristales de anglesita y celestina en gel de sílice. Transferencia de masa y criterios de cristalización Sílice. Transferencia de masa y criterios de cristalización

En el presente trabajo se analiza la cristalización de Celestina (SrSO,) mediante la técnica del gel de Sílice. El dispositivo experimental consistió en un sistema doble de difusión-reacción. Los reactivos empleados fueron SrCL, y N%S04 (0.5.0.3 y 0.1M. en ambos casos). La testificación experimental de la transferencia de masa y de la evolución del pH en el gel sirvió de vehículo para establecer unos "criterios de cristalización" que. unidos a la sobresaturación, han permitido justificar la posición del primer precipitado. Asimismo, se ha estudiado la influencia de la sobresaturación y de la velocidad de sobresaturación en la morfologíade crecimiento de los cristales de Celestina. El caracter de sistema abierto de la técnica empleada da lugar a que las condiciones de cristalización se modifiquen a lo largo del tiempo y del espacio. Dicha evolución queda reflejada en diferentes estadios morfológicos que se han interpretado de acuerdo con las características fisicoquímicas del medio

Influence of cooking (microwaving and broiling) on cylindrospermopsin concentration in muscle of nile tilapia (oreochromis niloticus) and characterization of decomposition products

Cylindrospermopsin (CYN) has become increasingly important as a freshwater algal toxin, showing cytotoxic effects. This toxin is able to bioaccumulate in freshwater food webs, representing a serious human health problem. Normally, fish is cooked before consumption, and CYN concentration can be altered. For the first time, the effects of microwaving and broiling for 1 and 2 min on CYN concentration and its decomposition products in fish muscle (Oreochromis niloticus) contaminated in the laboratory were investigated, using UPLC-MS/MS and Orbitrap. The results show that cooking the fish reduced unconjugated CYN levels by 11, 10 and 15% after microwaving for 1 and 2 min, and broiling for 2 min, respectively, compared to control fish. Different CYN decomposition products with m/z 416.1234 (7-epi-CYN) and m/z 336.16663 (diasteroisomers C-3A, C-3C, C-3D, C-3E, C-3F) are generated in fish samples submitted to cooking. Based on the relative abundance of the decomposition products, the possible degradation pathways taking place by microwaving may be through the formation of 7-epi-CYN and m/z 336.16663 compounds, whereas in the case of broiling the last route is the only one observed in this study. The influence of cooking and the toxicity characterization of the degradation products generated in CYN-contaminated fish are of importance for more realistic risk evaluation related to their consumption

Toxic Effects Produced by Anatoxin-a under Laboratory Conditions: A Review

The presence of cyanotoxins and its bioaccumulation in the food chain is an increasingly common problem worldwide. Despite the toxic effects produced by Anatoxin-a (ATX-a), this neurotoxin has been less studied compared to microcystins (MCs) and cylindrospermopsin (CYN). Studies conducted under laboratory conditions are of particular interest because these provide information which are directly related to the effects produced by the toxin. Currently, the World Health Organization (WHO) considers the ATX-a toxicological database inadequate to support the publication of a formal guideline reference value. Therefore, the aim of the present work is to compile all of the in vitro and in vivo toxicological studies performed so far and to identify potential data gaps. Results show that the number of reports is increasing in recent years. However, more in vitro studies are needed, mainly in standardized neuronal cell lines. Regarding in vivo studies, very few of them reflect conditions occurring in nature and further studies with longer periods of oral exposure would be of interest. Moreover, additional toxicological aspects of great interest such as mutagenicity, genotoxicity, immunotoxicity and alteration of hormonal balance need to be studied in depth.España Ministerio de Ciencia e Innovación PID2019-104890RBI00/AEI/10.13039/50110001103

Changes on cylindrospermopsin concentration and characterization of decomposition products in fish muscle (Oreochromis niloticus) by boiling and steaming

The occurrence of cylindrospermopsin (CYN) in toxic blooms of cyanobacteria is increasing in both frequency and distribution over the world. CYN persistence in water potentiates its accumulation in a wide range of aquatic animals destined to human consumption representing a serious problem. The aim of this work was to study for the first time the influence of cooking (boiling and steaming) for 1 or 2 min, on the stability of CYN in muscle of fish (Oreochromis niloticus) contaminated under laboratory conditions, also analyzing the waters in which samples were cooked. CYN was extracted and quantification was carried out by a developed and validated UPLC-MS/MS method. The results show that concentrations of CYN in fish are dependent on the cooking method, being the steaming for 2 min the most effective in reducing CYN levels (26%), followed by boiling for 2 min (18%), and significant differences have been found between the two periods assayed (1 min vs. 2 min). CYN was also detected in waters in which fish muscles were cooked in the range 0.10–0.28 μg/L. Moreover, characteristic decomposition products depending on the type of cooking were detected for the first time among the results of these treatments. The present findings emphasize the need for further studies to evaluate the influence of cooking in the presence of CYN in fish for a more realistic risk evaluation for the human health.Ministerio de Economía y Competitividad (AGL2015-64558-R, MINECO/FEDER, UE

New Method for Simultaneous Determination of Microcystins and Cylindrospermopsin in Vegetable Matrices by SPE-UPLC-MS/MS

Cyanotoxins are a large group of noxious metabolites with different chemical structure and mechanisms of action, with a worldwide distribution, producing effects in animals, humans, and crop plants. When cyanotoxin-contaminated waters are used for the irrigation of edible vegetables, humans can be in contact with these toxins through the food chain. In this work, a method for the simultaneous detection of Microcystin-LR (MC-LR), Microcystin-RR (MC-RR), Microcystin-YR (MC-YR), and Cylindrospermopsin (CYN) in lettuce has been optimized and validated, using a dual solid phase extraction (SPE) system for toxin extraction and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for analysis. Results showed linear ranges (5–50 ng g−1 f.w.), low values for limit of detection (LOD) (0.06–0.42 ng g−1 f.w.), and limit of quantification (LOQ) (0.16–0.91 ng g−1 f.w.), acceptable recoveries (41–93%), and %RSDIP values for the four toxins. The method proved to be robust for the three variables tested. Finally, it was successfully applied to detect these cyanotoxins in edible vegetables exposed to cyanobacterial extracts under laboratory conditions, and it could be useful for monitoring these toxins in edible vegetables for better exposure estimation in terms of risk assessment.España MINECO AGL2015-64558-