2,000 research outputs found
Person-to-Person Transmission of Andes Virus
Epidemiologic and genetic data show that person-to-person spread likely took place during the prodromal phase or shortly after it ended
Red Scliped: Evaluación del uso de tableros de selección de contenidos online en la docencia de Fisiología Animal I
Durante el curso 2013-2014 se implementó en la asignatura de Fisiología Animal I, del Grado en Biología de la Universidad de Alicante, un entorno personal de aprendizaje (EPA), a partir de la herramienta Scliped. Esta herramienta permitió desarrollar una red social de contenidos seleccionados por el profesorado, como estrategia docente para poner a disposición del alumnado recursos de excelencia que faciliten su aprendizaje. La inversión de tiempo y dinero requerida fue sensiblemente inferior a la necesaria para el desarrollo de materiales específicos equivalentes. El alumnado tuvo a su disposición un tablero de 130 contenidos seleccionados, distribuidos en 34 colecciones. Al finalizar el curso escolar 2013-2014, el EPA había recibido un total de 60.794 visitas. La evaluación del uso y conformidad del alumnado con esta herramienta mostró que, si bien opinaban que su uso era innovador, no podría sustituir la labor del profesorado. El porcentaje de adhesión a la herramienta fue bajo, tan sólo el 16% del alumnado encuestado, sin embargo, este grupo declaró que el uso de Scliped era sencillo y atractivo, que los contenidos eran pertinentes y estaban bien organizados, y que les habían facilitado el estudio y la comprensión de la materia
First assessment of the comparative toxicity of ivermectin and moxidectin in adult dung beetles: Sub-lethal symptoms and pre-lethal consequences
Among macrocyclic lactones (ML), ivermectin (IVM) and moxidectin (MOX) potentially affect all Ecdysozoan species, with dung beetles being particularly sensitive. The comparative effects of IVM and MOX on adult dung beetles were assessed for the first time to determine both the physiological sub-lethal symptoms and pre-lethal consequences. Inhibition of antennal response and ataxia were tested as two intuitive and ecologically relevant parameters by obtaining the lowest observed effect concentration (LOEC) values and interpolating other relevant toxicity thresholds derived from concentration-response curves (IC50, as the concentration of each ML where the antennal response is inhibited by half; and pLC50, as the quantity of ingested ML where partial paralysis was observed by half of treated individuals) from concentration-response curves. Both sub-lethal and pre-lethal symptoms obtained in this study coincided in that IVM was six times more toxic than MOX for adult dung beetles. Values of LOEC, IC50 and pLC50 obtained for IVM and MOX evaluated in an environmental context indicate that MOX, despite needing more time for its elimination in the faeces, would be half as harmful to dung beetles as IVM. This approach will be valuable to clarify the real impact of MLs on dung beetle health and to avoid the subsequent environmental consequences.Project CGL2015-68207-R of the Secretaría de Estado de Investigación–Ministerio de Economía y Competitividad
A Calcium-Dependent Chloride Current Increases Repetitive Firing in Mouse Sympathetic Neurons
Ca2+-activated ion channels shape membrane excitability in response to elevations in intracellular Ca2+. The most extensively studied Ca2+-sensitive ion channels are Ca2+-activated K+ channels, whereas the physiological importance of Ca2+-activated Cl- channels has been poorly studied. Here we show that a Ca2+-activated Cl- currents (CaCCs) modulate repetitive firing in mouse sympathetic ganglion cells. Electrophysiological recording of mouse sympathetic neurons in an in vitro preparation of the superior cervical ganglion (SCG) identifies neurons with two different firing patterns in response to long depolarizing current pulses (1 s). Neurons classified as phasic (Ph) made up 67% of the cell population whilst the remainders were tonic (T). When a high frequency train of spikes was induced by intracellular current injection, SCG sympathetic neurons reached an afterpotential mainly dependent on the ratio of activation of two Ca2+-dependent currents: the K+ [IK(Ca)] and CaCC. When the IK(Ca) was larger, an afterhyperpolarization was the predominant afterpotential but when the CaCC was larger, an afterdepolarization (ADP) was predominant. These afterpotentials can be observed after a single action potential (AP). Ph and T neurons had similar ADPs and hence, the CaCC does not seem to determine the firing pattern (Ph or T) of these neurons. However, inhibition of Ca2+-activated Cl- channels with anthracene-9′-carboxylic acid (9AC) selectively inhibits the ADP, reducing the firing frequency and the instantaneous frequency without affecting the characteristics of single- or first-spike firing of both Ph and T neurons. Furthermore, we found that the CaCC underlying the ADP was significantly larger in SCG neurons from males than from females. Furthermore, the CaCC ANO1/TMEM16A was more strongly expressed in male than in female SCGs. Blocking ADPs with 9AC did not modify synaptic transmission in either Ph or T neurons. We conclude that the CaCC responsible for ADPs increases repetitive firing in both Ph and T neurons, and it is more relevant in male mouse sympathetic ganglion neurons.This work was supported by grants PB92-0347 and PM95-0107 (from the Dirección General de Investigación Científica y Técnica, Spain) to Roberto Gallego and the Instituto de Cultura Juan Gil-Albert (Diputación de Alicante, Spain) to FdC. Our current work was supported by grants SAF2016-77575-R and RD16/0015/0019 (both from Ministerio de Economía, Innovación y Competitividad-MINEICO, Spain) to FdC and Generalitat Valenciana, PROMETEOII/2015/016 to AN. CIBERDEM is an initiative of the Instituto de Salud Carlos III
Low doses of ivermectin cause sensory and locomotor disorders in dung beetles
Ivermectin is a veterinary pharmaceutical generally used to control the ecto- and endoparasites of livestock, but its use has resulted in adverse effects on coprophilous insects, causing population decline and biodiversity loss. There is currently no information regarding the direct effects of ivermectin on dung beetle physiology and behaviour. Here, based on electroantennography and spontaneous muscle force tests, we show sub-lethal disorders caused by ivermectin in sensory and locomotor systems of Scarabaeus cicatricosus, a key dung beetle species in Mediterranean ecosystems. Our findings show that ivermectin decreases the olfactory and locomotor capacity of dung beetles, preventing them from performing basic biological activities. These effects are observed at concentrations lower than those usually measured in the dung of treated livestock. Taking into account that ivermectin acts on both glutamate-gated and GABA-gated chloride ion channels of nerve and muscle cells, we predict that ivermectin’s effects at the physiological level could influence many members of the dung pat community. The results indicate that the decline of dung beetle populations could be related to the harmful effects of chemical contamination in the dung.Financial support was provided by the Project OAPN 762/2012 of the Organismo Autónomo de Parques Nacionales-Ministerio de Agricultura, Alimentación y Medio Ambiente
Identification of novel biomarkers of abdominal aortic aneurysms by 2D-DIGE and MALDI-MS from AAA-thrombus-conditioned media
In the search for novel biomarkers, noncandidate-based proteomic strategies open up new opportunities to gain a deeper insight into disease processes regarding their molecular mechanisms, the risk factors involved, and the monitoring of disease progression. To carry out these complex analyses, the combined use of gel electrophoresis with mass spectrometry (MS) represents a powerful choice. In addition, the introduction of protein dye labeling has notably improved the reliability of differential expression studies by increasing the statistical significance of the protein candidates. Here, we describe a strategy where different layers (luminal/abluminal) from the intraluminal thrombus (ILT) of human abdominal aortic aneurysm (AAA) patients were incubated in protein-free medium. Then, the levels of the proteins released were compared by two-dimensional differential in-gel electrophoresis (2D-DIGE) and the proteins of interest identified by MS. We consider that the use of tissue-conditioned media could offer a substantial advantage in the analytical study of biological fluids, as they provide a source of proteins to be released to the bloodstream, which could serve as potential circulating biomarkers.This chapter has been supported by the EC, FAD project (FP-7, HEALTH F2-2008-200647), the Spanish MICIN (SAF2010/21852), Ministerio de Sanidad y Consumo, Instituto de Salud Carlos III, Redes RECAVA (RD06/0014/0035), EUS2008-03565, and Fundacion Pro CNIC.S
G protein-coupled estrogen receptor activation by bisphenol-A disrupts the protection from apoptosis conferred by the estrogen receptors ERα and ERβ in pancreatic beta cells
17β-estradiol protects pancreatic β-cells from apoptosis via the estrogen receptors ERα, ERβ and GPER. Conversely, the endocrine disruptor bisphenol-A (BPA), which exerts multiple effects in this cell type via the same estrogen receptors, increased basal apoptosis. The molecular-initiated events that trigger these opposite actions have yet to be identified. We demonstrated that combined genetic downregulation and pharmacological blockade of each estrogen receptor increased apoptosis to a different extent. The increase in apoptosis induced by BPA was diminished by the pharmacological blockade or the genetic silencing of GPER, and it was partially reproduced by the GPER agonist G1. BPA and G1-induced apoptosis were abolished upon pharmacological inhibition, silencing of ERα and ERβ, or in dispersed islet cells from ERβ knockout (BERKO) mice. However, the ERα and ERβ agonists PPT and DPN, respectively, had no effect on beta cell viability. To exert their biological actions, ERα and ERβ form homodimers and heterodimers. Molecular dynamics simulations together with proximity ligand assays and coimmunoprecipitation experiments indicated that the interaction of BPA with ERα and ERβ as well as GPER activation by G1 decreased ERαβ heterodimers. We propose that ERαβ heterodimers play an antiapoptotic role in beta cells and that BPA- and G1-induced decreases in ERαβ heterodimers lead to beta cell apoptosis. Unveiling how different estrogenic chemicals affect the crosstalk among estrogen receptors should help to identify diabetogenic endocrine disruptors.This work was supported by Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER) grants BPU2017-86579-R (AN), PID2020-117294RB-I00 (AN, JM-P), Generalitat Valenciana PROMETEO II/2020/006 (AN) and European Union’s Horizon 2020 research and innovation programme under grant agreement GOLIATH No. 825489 (AN). Author laboratories hold grants from Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación y Fondo Europeo de Desarrollo Regional (FEDER) RTI2018-096724-B-C21 (J-AE) and PID2020-117569RA-I00 (LM). PROMETEO/2016/006 (J-AE) and SEJI/2018/023 (LM) supported by Generalitat Valenciana, Spain. Robert A. Welch Foundation (grant E-0004) (J-AG). CIBERDEM is an initiative of the Instituto de Salud Carlos III
Bisphenol A Regulates Sodium Ramp Currents in Mouse Dorsal Root Ganglion Neurons and Increases Nociception
17β-Estradiol mediates the sensitivity to pain and is involved in sex differences in nociception. The widespread environmental disrupting chemical bisphenol A (BPA) has estrogenic activity, but its implications in pain are mostly unknown. Here we show that treatment of male mice with BPA (50 µg/kg/day) during 8 days, decreases the latency to pain behavior in response to heat, suggesting increased pain sensitivity. We demonstrate that incubation of dissociated dorsal root ganglia (DRG) nociceptors with 1 nM BPA increases the frequency of action potential firing. SCN9A encodes the voltage-gated sodium channel Nav1.7, which is present in DRG nociceptors and is essential in pain signaling. Nav1.7 and other voltage-gated sodium channels in mouse DRG are considered threshold channels because they produce ramp currents, amplifying small depolarizations and enhancing electrical activity. BPA increased Nav-mediated ramp currents elicited with slow depolarizations. Experiments using pharmacological tools as well as DRG from ERβ−/− mice indicate that this BPA effect involves ERα and phosphoinositide 3-kinase. The mRNA expression and biophysical properties other than ramp currents of Nav channels, were unchanged by BPA. Our data suggest that BPA at environmentally relevant doses affects the ability to detect noxious stimuli and therefore should be considered when studying the etiology of pain conditions.The authors’ laboratories are funded by the Ministerio de Economía, Industria y Competitividad, Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER), BFU2017-86579-R (A.N.) and Generalitat Valenciana, PROMETEOII/2015/016 (A.N.). CIBERDEM is an initiative of the Instituto de Salud Carlos III. J.-A. G. was supported by a fellowship from the A. Welch Foundation (Grant E-0004)
Molecular mechanisms involved in the non-monotonic effect of bisphenol-a on ca2+ entry in mouse pancreatic β-cells
In regulatory toxicology, the dose-response relationship is a key element towards fulfilling safety assessments and satisfying regulatory authorities. Conventionally, the larger the dose, the greater the response, following the dogma “the dose makes the poison”. Many endocrine disrupting chemicals, including bisphenol-A (BPA), induce non-monotonic dose response (NMDR) relationships, which are unconventional and have tremendous implications in risk assessment. Although several molecular mechanisms have been proposed to explain NMDR relationships, they are largely undemonstrated. Using mouse pancreatic β-cells from wild-type and oestrogen receptor ERβ−/− mice, we found that exposure to increasing doses of BPA affected Ca2+ entry in an NMDR manner. Low doses decreased plasma membrane Ca2+ currents after downregulation of Cav2.3 ion channel expression, in a process involving ERβ. High doses decreased Ca2+ currents through an ERβ-mediated mechanism and simultaneously increased Ca2+ currents via oestrogen receptor ERα. The outcome of both molecular mechanisms explains the NMDR relationship between BPA and Ca2+ entry in β-cells.The author laboratories are funded by the Ministerio de Economía, Industria y Competitividad, Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER), SAF2014-58335-P (AN) and BFU2013-42789-P (IQ) and Generalitat Valenciana, PROMETEOII/2015/016 (AN). CIBERDEM is an initiative of the Instituto de Salud Carlos III. J-A G was supported by the Robert A. Welch Foundation (E-0004)
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