1,556 research outputs found

    Electroencephalogram background activity characterization with Detrended Moving Average in Alzheimer's disease patients

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    The aim of this study was to analyse the electroencephalogram (EEG) background activity in Alzheimer's disease (AD) with the Detrended Moving Average (DMA) method, a new approach to quantify correlation properties in non-stationary signals with underlying trends. EEGs were recorded from the 19 scalp loci of the international 10-20 system in 11 AD patients and 11 age-matched controls. Our results showed two scaling regions in all subjects' channels, with a clear bend when their corresponding slopes (alpha(1) and alpha(2)) were distinctly different. With the exception of electrode T4, the alpha(1) values were lower in control subjects than in AD patients, with significant differences at TS, P3, P4 and O1 (p < 0.01, Student's t-test). On the other hand, alpha(2) values were higher in control subjects than in AD patients, with significant differences only at F4. Furthermore, we evaluated the ability of alpha(2) to discriminate AD patients from control subjects at these electrodes using ROC plots. We obtained a maximum accuracy of 81.82% at O1 with alpha(1) and at F4 with alpha(2). These findings suggest that the scaling behaviour of the EEG is sensitive to AD and that the DMA method could help to increase our insight into brain dysfunction in AD

    Analysis of electroencephalograms in Alzheimer's disease patients with multiscale entropy

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    The aim of this study was to analyse the electroencephalogram (EEG) background activity of Alzheimer’s disease (AD) patients using the Multiscale Entropy (MSE). The MSE is a recently developed method that quantifies the regularity of a signal on different time scales. These time scales are inspected by means of several coarse-grained sequences formed from the analysed signals. We recorded the EEGs from 19 scalp electrodes in 11 AD patients and 11 age-matched controls and estimated the MSE profile for each epoch of the EEG recordings. The shape of the MSE profiles reveals the EEG complexity, and it suggests that the EEG contains information in deeper scales than the smallest one. Moreover, the results showed that the EEG background activity is less complex in AD patients than control subjects. We found significant difference

    Nefroblastoma espinal en un Rottweiler

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    El nefroblastoma espinal es una neoplasia infrecuente en el perro. Se diagnostica en animales jóvenes, afectando, casi exclusivamente, al segmento medular T10 -L2. En este trabajo, e describen los signos clínicos, resultados de las pruebas complementarias y los hallazgos histopatológicos de un perro con un nefroblastoma espinal.

    Development of an antibody-based capture enzyme-linked immunosorbent assay for detecting echinostoma caproni (trematoda) in experimentally infected rats: kinetics of coproantigen excretion

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    The present study reports on the development of a coproantigen capture enzyme-linked immunosorbent assay (ELISA) for detecting Echinostoma caproni in experimentally infected rats. The capture ELISA was based on polyclonal rabbit antibodies that recognize excretory–secretory (ES) antigens. The detection limit of pure ES was 3 ng/ml in sample buffer and 60 ng/ml in fecal samples. The test was evaluated using a follow-up of 10 rats experimentally infected with 100 metacercariae of E. caproni, and the results were compared with those of other diagnostic methods such as parasitological examination and antibody titers determined by indirect ELISA. Coproantigens were detected in all the infected rats from the first day postinfection (DPI). The period of maximal coproantigen excretion was between 7 and 21 DPI. The values remained positive until 49–56 DPI, coinciding with the disappearance of the eggs in the stool samples of the infected rats. The kinetics of coproantigen detection were correlated with those of egg output. The present assay provides an alternative tool for the diagnosis of the echinostome infections. The proposed capture ELISA makes possible an earlier diagnosis than that provided by parasitological examination and indirect ELISA and also allows for the differentiation of past and current infections. Our results show that this assay can also be used to monitor the course of echinostome infections.Toledo Navarro, Rafael, [email protected] ; Espert Fernandez, Ana M., [email protected] ; Marcilla Diaz, Antonio, [email protected] ; Esteban Sanchis, Jose Guillermo, [email protected]

    Explosión demográfica de un hidrozoo exótico en una isla oceánica

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    The arrival of non-indigenous species into new areas is one of the main processes altering the oceans globally. Macrorhynchia philippina is a large-sized colonial hydrozoan of an invasive nature. To obtain a deeper understanding of the process of colonization of new areas, it is essential to describe the ecological pattern through scales of temporal and spatial variation. In this study, we describe the colonization by M. Philippina of an oceanic island (Gran Canaria Island, Canary Islands, eastern Atlantic). We describe the abundance and size structure patterns of M. Philippina in three nearshore habitats, rocky reefs, seagrass meadows and rhodolith seabeds, at times before (2014), during (2016) and after (2017) the demographic explosion of this species. On rocky reefs and rhodolith seabeds, the abundance of colonies increased dramatically in 2017 rel­ative to 2014, e.g. from 0 to 138 colonies/100 m2. On seagrass meadows, however, the colonies were smaller. In summary, M. Philippina shows an ecological plasticity to rapidly colonize different types of nearshore habitats, but with varying success.La aparición de especies exóticas es uno de los principales factores que alteran los océanos de forma global. Mac­rorhynchia philippina es un hidrozoo colonial de tamaño grande y naturaleza invasora. Para tener un mejor conocimiento del proceso de colonización es fundamental describir los patrones ecológicos a escalas de variación temporal y espacial. En este estudio, describimos el proceso de colonización por M. Philippina en una isla oceánica (Gran Canaria, Islas Canarias, Atlántico oriental). Se describen los patrones de abundancia y estructura de tallas de M. Philippina en tres hábitats costeros: arrecifes rocosos, praderas de fanerógamas marinas y fondos de rodolitos, antes (2014), durante (2016) y después (2017) de la explosión demográfica de la especie. Sobre arrecifes rocosos y en fondos de rodolitos, la abundancia de las colonias se incrementó drásticamente en 2017 con relación a 2014, e.g. desde 0 hasta 138 colonias/100 m2; este incremento fue menor en las praderas de fanerógamas marinas. En las praderas marinas, la longitud de las colonias fue más pequeña que sobre ar­recifes rocosos y fondos de rodolitos. Consecuentemente, la colonización rápida por M. Philippina demuestra su plasticidad ecológica para colonizar diferentes tipos de hábitats costeros, aunque con diferente éxito

    Interstrand DNA covalent binding of two dinuclear Ru(ii) complexes. Influence of the extra ring of the bridging ligand on the DNA interaction and cytotoxic activity

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    In this work, we report experimental and computational evidences for the intercalation into the DNA base pairs of the free quinones Quinizarin (Q), Naphthazain (N) and the interstrad covalent binding of their p-cymene di-Ruthenium(II) complexes (Cl2Ru2X, with X = N, Q bridging ligands). The intercalation extent for the N complex was larger than for Q, in good agreement with higher relative contour length and melting temperature for the same CX/CDNA ratio and with the computacional mean stacking distances between the ligand and the nearest base-pair (3.34Å and 3.19Å) for N and Q, respectively. However, the apparent binding constant of Q/DNA, two orders higher than that of N/DNA, denotes that the thermal stability of X/DNA complex is more related to the degree of intercalation than to the binding constants magnitude. Cl2Ru2X complexes undergo aquation, forming the aqua-derivatives [(H2O)2Ru2X]2+. These can further bind covalently to DNA via interstrand crosslinking, through both Ru centres and two N7 sites of consecutive Guanines, to give (DNA1,2)Ru2X complexes, by a mechanism similar to that of cisplatin. To the best of our knowledge, this type of interaction with dinuclear Ru(II) complexes has not been reported hitherto. The experimental and computational results reveal that the number of rings of the aromatic moiety and the covalent binding to DNA play a key role in the behaviour of the quinones and their Ru(II) derivatives. The cytotoxicity of the ligands and the corresponding Ru(II) complexes was evaluated in the MCF-7, A2780, A2780cis tumour cells and in the healthy cell line MRC-5. The cytotoxic activity was notable for the N compound and negligible for Q. The IC50 values and the resistance (RF) and selectivity (SF) factors show that the Cl2Ru2N complex is the most promising among the four studied anticancer drugs
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