Comparative assessment of microplastics and microalgae as vectors of mercury and chlorpyrifos in the copepod Acartia tonsa

Microplastics (MPs) raise concerns not only as pollutants themselves, but also due to their ability to act as vectors of pollutants adsorbed from seawater, transferring them to marine organisms. However, the relevance of MPs as carriers of pollutants compared to microalgae needs further exploration. This study compared the role of MPs (2–10 μm non-oxidized and 10–15 μm oxidized high-density polyethylene) and natural organic particles (Rhodomonas lens microalgae, MA) as carriers of mercury (Hg, 2.3 μg Hg/L) and chlorpyrifos (CPF, 1.0 μg CPF/L) to adult Acartia tonsa copepods, after 24–48 h exposure. Dose-response experiments were first performed with adult female copepods exposed to oxidized MPs (0.25–4.0 mg/L), waterborne Hg (0.01–10.0 μg/L) and Ox MPs + Hg (0.25–4.0 mg oxidized MPs/L + 0.50–8.0 μg Hg/L) for 48 h, to complement previous studies that focused on the pesticide CPF. Effects were evaluated with four replicates for physiological and reproductive responses (6 females/replicate), biochemical techniques (40 individuals/replicate) and Hg/CPF bioaccumulation measurements (1000 individuals/replicate). Copepods accumulated Hg/CPF similarly from dissolved pollutants (6204 ± 2265 ng Hg/g and 1251 ± 646 ng CPF/g) and loaded MPs (3125 ± 1389 ng Hg/g and 1156 ± 266 ng CPF/g), but significantly less from loaded MA (21 ± 8 ng Hg/g and 173 ± 80 ng CPF/g). After 24–48 h, copepods exposed to MPs + Hg/CPF showed generally greater biological effects than those exposed to dissolved Hg/CPF or to MA + Hg/CPF, although differences were not statistically significant. MA + CPF had significantly lower AChE inhibition (1073.4 nmol min−1 mg−1) and MA + Hg lower GRx induction (48.8 nmol min−1 mg−1) compared to MPs + Hg/CPF and dissolved Hg/CPF (182.8–236.4 nmol min−1 mg−1 of AChE and 74.1–101.7 nmol min−1 mg−1 of GRx). Principal component analysis suggested different modes of action for Hg and CPF.Xunta de GaliciaAgencia Estatal de InvestigaciónUniversidade de Vigo/CISU

Seasonal variability of antioxidant biomarkers in mussels Mytilus galloprovincialis from the Spanish N-NW coast.

Marine organisms are highly seasonal animals in relation to their physiology which depends, among other factors, on their annual cycle of reproduction. In bivalves, reproductive cycle is regulated by two main environmental factors: temperature and food availability. Specifically, bivalves are undergoing high variable environmental conditions. Integrated pollution monitoring carried out by the IEO along the N-NW coast of Spain has evidenced that the variability of the environmental conditions produce spatial differences in mussel condition which seems to mask the biomarker responses to pollution. Thus, there is a need to study the natural variability of biological responses used as pollution biomarkers at different seasons and in different habitats in order to establish an adequate link between chemical pollution and biological responses. This study aims to assess the natural variability of some biomarker responses on the mussel Mytilus galloprovincialis in 5 different sites from the Spanish Marine Pollution Monitoring Program which are differentiated in their natural ecology and their anthropogenic pressure. The potential influence of environmental and endogenous factors that can cause biomarker´s seasonal fluctuations was examined. Biomarkers analyzed in this study are considered among the most usefull biological tools applied in pollution monitoring programs, including exposure indicators (superoxide dismutase –SOD-, catalase –CAT-, glutathione reductase –GR-, glutathione peroxidase –GPx-, glutathione-s-transfersase –GST-) and a damage indicator (lipid peroxidation –LPO-). Mussel biological characterization from a histological and anatomical point of view was also performed. Results evidenced that biomarkers were clearly influenced by the annual cycle (all of them were affected by the season) but also significant differences between sites were found in some biomarkers (GR and GST). Thus, not only environmental but also endogenous factors must be considered in monitoring programs in the study of biomarkers responses.Society of Environmenta Toxicology and Chemistry (SETAC

Electromyographic activity of the jaw muscles and mandibular kinematics in young adults with theoretically ideal dental occlusion : reference values

A necessary step to use neuromuscular analysis as diagnostic tool is to establish normal reference values for the physiological range in a healthy population. Surface electromyographic (sEMG) activity of the jaw muscles and mandibular kinematics were measured in young adults with theoretically ideal dental occlusion to determine normal reference values during different tasks. Differences between the sexes were evaluated. Forty young adults (20 men, 20 women; mean age 22.8 ± 3.9 years) with theoretically ideal dental occlusion were selected using very restrictive criteria. sEMG activity of the anterior temporalis (AT), posterior temporalis, masseter (MA), and suprahyoid muscles were evaluated in the rest position and during swallowing, mastication, and clenching. Mandibular kinematics in the rest position and during maximum excursions were assessed. Asymmetry, activity, and torque indices and MA/AT ratios were calculated. For all muscles, sEMG values were 1.01-3.57 µV at rest, 3.50-10.85 µV during swallowing, and 41.04-86.59 µV during mastication. During clenching, values were 230.08-243.55 µV for the AT and MA muscles. Mean total asymmetry, activity, and torque indices at rest were 20.34 %, -15.04 %, and 19.02 %, respectively; during clenching, these values were 6.14 %, -2.62 %, and 4.46 %. MA/AT ratios were near 1. Kinematic measurements during lateral excursion, protrusive and maximum opening were 7.54, 8.44, and 37.38 mm respectively; lateral mandibular shift was 1.41 mm; free way and lateral displacement at rest were 1.40 and 0.26 mm. Right MA activity during mastication and clenching was higher in men than women. Reference values for sEMG activity and mandibular kinematics were determined. Some muscular asymmetry and torque were observed

Presente y Futuro en el Descubrimiento de Fármacos para la Enfermedad de Chagas

Chagas disease, also known as American trypanosomiasis, is caused by infection with the Trypanosoma cruzi. The Pan American Health Organization (PAHO) estimates that 7.7 million persons currently have T cruzi infection in the 21 endemic countries. This disease can be transmitted to humans by insect vectors that are found only in the American continent, mainly, in rural areas with unhealthy housing conditions where poverty is a general concern. Nifurtimox and benznidazole are the only drugs used against this disease however sometimes they are not available. The treatment of Chagas disease with nifurtimox or benznidazole is unsatisfactory because of their limited efficacy on the prevalent chronic stage of the disease and their toxic side effects. It is, therefore, necessary the development of new effective antichagasic drugs for the suitable treatment of this disease. The development of new drugs for Chagas disease requires a multidisciplinary approach involving diverse disciplines such as molecular and cellular biology, chemistry, bioinformatics, biochemistry, pharmacology and toxicology. This revision describes the diferents strategies used for drug discovery on chagas disease treatment. The most classic stratetis as the design of analogous, sreening or biological information as well as the methods based on chemiinformatics have been discussed in this work.La enfermedad de Chagas, también conocida como Tripanosomiasis Americana es una enfermedad parasitaria causada por el Trypanosoma cruzi. Se estima que alrededor de 7,7 millones de personas se encuentran infectadas y padecen la enfermedad de Chagas. Esta enfermedad silenciosa que esta estrechamente relacionada con la pobreza, es transmitida a los humanos por unos insectos que se encuentran exclusivamente en el continente americano, principalmente en áreas rurales con muy deficientes condiciones de salubridad. Los fármacos existentes (nifurtimox y benznidazol), no siempre disponibles, constituyen un tratamiento paliativo, pero no curan la enfermedad y no son aceptables desde un punto de vista terapéutico debido a sus efectos secundarios indeseables y a su falta de eficacia. Por tanto, es necesario el desarrollo urgente de nuevos tratamientos y por tanto, sería muy conveniente la utilización del diseño racional en todas las etapas. El diseño de fármacos es una tarea compleja que requiere la colaboración interdisciplinar de muchos especialistas en diferentes campos de la ciencia. El presente trabajo describe de manera estructurada las diferentes estrategias que se han utilizado y las que se pueden utilizar en el futuro para el descubrimiento de nuevos fármacos para la enfermedad de Chagas. Se recogen las estrategias más clásicas como el diseño de análogos, el cribado sistemático o el basado en la información biológica y los métodos más novedosos basados en lo que se conoce como quimioinformática