Development of two Spanish versions of the Verbal Selective Reminding Test

El Test de Recuerdo Verbal Selectivo (TRVS) es una de las pruebas más extensamente utilizadas para la evaluación del aprendizaje y la memoria verbales. Sin embargo, este test ha sido construido principalmente para evaluar a pacientes de habla inglesa, no existiendo todavía ninguna versión española que pueda ser utilizada para evaluar a pacientes de habla hispana. Para solventar este problema, se construyeron dos versiones españolas del Test de Recuerdo Verbal Selectivo administrándose a 48 sujetos sanos, 19-31 años, en dos sesiones separadas. Encontramos que las respuestas de los sujetos a las dos versiones fueron comparables, excepto para un índice. Todas las variables sobre ambas formas presentaron correlaciones positivas significativas. También se estudió la fiabilidad test-retest para cada orden, encontrándose que el orden 2 (en el que la forma 2 se administró primero) fue más fiable que el orden 1 (donde la forma 1 se administró primero).The Selective Reminding procedure has become a widely used test for evaluating verbal learning and memory. However, since this test was mainly devised for use in English speaking individuals, disadvantages could appear when translations of the test are applied to Spanish speaking patients. To overcome these difficulties, two Spanish versions of the Verbal Selective Reminding Test were devised and administered to 48 healthy individuals, 19-31 years in age, in two separate sessions. We found that performances on the two forms were comparable, except for one measure. All the variables on both forms yielded significant positive correlations. We also examined test-retest reliability separately for both possible orders, with Order 2 (Form 2 administered first) being more reliable than Order 1 (Form 1 administered first)

Composición química del caparazón del cangrejo de las nieves (Chionoecetes opilio)

The snow crab (Chionoecetes opilio) shells have potential important economical and industrial applications due to theirchemical composition. They have a high content of protein (34.2% dw) and essential amino acids; they also have fat (17.1% dw), with a high proportion of ω3 polyunsaturated fatty acids. About 28.5% dw corresponds to ash (calcium, phosphorous, and magnesium are the major minerals). The mean concentrations of vitamin E, astaxantin, and β-carotene were 23.3, 9.49, and 0.2 mg/100 g dw, respectively. Results presented in this study indicate that snow crab by-products may serve as excellent nutritional components for future applications in the health and food sectorsLos caparazones del cangrejo de las nieves (Chionoecetes opilio) pueden tener aplicaciones industriales y económicas potencialmente importantes debido a su composición química. En su composición destaca el elevado contenido en proteínas (34,2% ms) y aminoácidos esenciales, en lípidos totales (17,1% ms), con una elevada proporción de ácidos grasos poliinsaturados ω3, en cenizas (28% (ms), principalmente calcio, fosfatos y magnesio. La concentración media de vitamina E es de 23,3 mg /100 g ms, de astaxantina 9,49 mg /100 g ms, de β-caroteno 0,2 mg /100 g ms. El alto contenido en nutrientes, puesto de manifiesto en este estudio, indica que los productos de desecho del cangrejo de las nieves pueden ser utilizados como productos de alto valor añadido para su aplicación en suplementación de dietas para alimentación humana y acuiculturaThis work was supported by the Consellería de Educación e Ordenación Universitaria da Xunta de Galicia (Project PGIDIT03BTF00701CT). Technical assistance of Patricia Ferraces Casais is highly appreciatedS

Horizontal pendular nystagmus and ataxia secondary to severe hypomagnesemia

Horizontal pendular nystagmus and ataxia secondary to severe hypomagnesemia Background: Severe hypomagnesemia is an increasingly recognized cause of acute and reversible cerebellar ataxia, often accompanied by cerebellar oculomotor signs such as jerky horizontal or downbeat nystagmus and very rarely ocular flutter. Phenomenology Shown: This video illustrates horizontal pendular nystagmus in a patient with acute onset cerebellar ataxia associated with severe hypomagnesemia. Educational value: Acquired pendular nystagmus can be distinguished from macrosaccadic oscillations and ocular flutter in that the former is composed of two slow phases of equal velocity and the latter of two fast phases of saccadic type with or without intersaccadic interval, respectively. It is most commonly associated with demyelinating, toxic, metabolic, and genetic disorders, but has not been reported in association with severe hypomagnesemia

Origin and evolution of "Mytilus" mussel satellite DNAs

[Abstract] A phylogenetic reconstruction based on the amplification of 3 satellite DNAs (stDNAs) was carried out in 1 crustacean species and 15 bivalve species of the subclass Pteriomorphia (10, subfamily Mytilinae; 1, subfamily Litophaginae; 1, subfamily Modiolinae, all belonging to family Mytilidae; 1, family Arcidae; and 2, family Pectinidae). The sequences obtained showed motifs with high similarity to those of A and B boxes of tRNA promoter regions. Dot-blot hybridizations revealed that the 3 stDNAs are present mainly in high copy numbers for each species of the genus Mytilus, whereas for the other species they appear in low copy numbers. Maximum-parsimony trees evidenced a tendency to group Mytilus clones together, and species containing these sequences as a single copy were distributed among the different mytilids. Finally, the possible origin and evolution of these stDNAs is discussed.Xunta de Galicia; 10302B97Comisión Interministerial de Ciencia y Tecnología (I+D); ALI97-043

Suppression of no-longer relevant information in Working Memory: an alpha-power related mechanism?

Selective attention can enhance Working Memory (WM) performance by selecting relevant information, while preventing distracting items from encoding or from further maintenance. Alpha oscillatory modulations are a correlate of visuospatial attention. Specifically, an enhancement of alpha power is observed in the ipsilateral posterior cortex to the locus of attention, along with a suppression in the contralateral hemisphere. An influential model proposes that the alpha enhancement is functionally related to the suppression of information. However, whether ipsilateral alpha power represents a mechanism through which no longer relevant WM representations are inhibited has yet not been explored. Here we examined whether the amount of distractors to be suppressed during WM maintenance is functionally related to alpha power lateralized activity. We measure EEG activity while participants (N=36) performed a retro-cue task in which the WM load was varied across the relevant/irrelevant post-cue hemifield. We found that alpha activity was lateralized respect to the locus of attention, but did not track post-cue irrelevant load. Additionally, non-lateralized alpha activity increased with post-cue relevant load. We propose that alpha lateralization associated to retro-cuing might be related to a general orienting mechanism toward relevant representationThis work was supported by the Ministerio de Economía y Competitividad (MINECO) of Spain and European Regional Development Fund (ERDF) (UAMA13-4E-2192) to PC; and by the Ministerio de Economía y Competitividad (MINECO) of Spain (Grants PSI2012-37535 and PSI2015-68368-P) and by the Comunidad de Madrid (Grant H2015/HUM-3327) to JA

The natural frequencies of the resting human brain: an MEG-based atlas

Brain oscillations are considered to play a pivotal role in neural communication. However, detailed information regarding the typical oscillatory patterns of individual brain regions is surprisingly scarce. In this study we applied a multivariate data-driven approach to create an atlas of the natural frequencies of the resting human brain on a voxel-by-voxel basis. We analysed resting-state magnetoencephalography (MEG) data from 128 healthy adult volunteers obtained from the Open MEG Archive (OMEGA). Spectral power was computed in source space in 500 ms steps for 82 frequency bins logarithmically spaced from 1.7 to 99.5 Hz. We then applied k-means clustering to detect characteristic spectral profiles and to eventually identify the natural frequency of each voxel. Our results provided empirical confirmation of the canonical frequency bands and revealed a region-specific organisation of intrinsic oscillatory activity, following both a medial-to-lateral and a posterior-to-anterior gradient of increasing frequency. In particular, medial fronto-temporal regions were characterised by slow rhythms (delta/theta). Posterior regions presented natural frequencies in the alpha band, although with differentiated generators in the precuneus and in sensory-specific cortices (i.e., visual and auditory). Somatomotor regions were distinguished by the mu rhythm, while the lateral prefrontal cortex was characterised by oscillations in the high beta range (>20 Hz). Importantly, the brain map of natural frequencies was highly replicable in two independent subsamples of individuals. To the best of our knowledge, this is the most comprehensive atlas of ongoing oscillatory activity performed to date. Critically, the identification of natural frequencies is a fundamental step towards a better understanding of the functional architecture of the human brainThis work was supported by FEDER/Ministerio de Ciencia, Innovación y Universidades – Agencia Estatal de Investigación, Spain (grant PGC2018-100682-B-I00 to AC and PC) and the Comunidad de Madrid POEJ/FSE (grant PEJD-2017-PRE/SOC-3859 to AC). MM was supported by the Universidad Autónoma de Madrid (FPI-UAM-2017 fellowship). JG was supported by Deutsche Forschungsgemeinschaft (GR 2024/5-1 and GR 2024/8-1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

Comparative analysis of different satellite DNAs in four Mytilus species

[Abstract:] We report the characterization of three satellite DNAs in four species of mussel: Mytilus edulis, Mytilus galloprovincialis, Mytilus trossulus, and Mytilus californianus. The monomers of the Apa I satellite DNAs were 173, 161, and 166 bp long. These satellite monomers were used to construct phylogenetic trees to infer relationships among these species. The topologies obtained clearly indicate that M. californianus is the most divergent species with respect to the other three. Furthermore, localization of satellite DNAs on metaphase chromosomes was performed using fluorescent in situ hybridization (FISH). Fluorescent signals revealed a different organization and distribution of these three satellite DNAs.Ministerio de Ciencia y Tecnología; 1FD97-1295España. Dirección General de Enseñanza Superior; PB97-1136Catalunya. Direcció General de Recerca; SGR99-18

Molecular evolutionary characterization of the mussel "Mytilus" histone multigene family: first record of a tandemly repeated unit of five histone genes containing an H1 subtype with orphon features

[Abstract] The present work represents the first characterization of a clustered histone repetitive unit containing an H1 gene in a bivalve mollusk. To complete the knowledge on the evolutionary history of the histone multigene family in invertebrates, we undertake its characterization in five mussel Mytilus species, as an extension of our previous work on the H1 gene family. We report the quintet H4–H2B–H2A–H3–H1 as the major organization unit in the genome of Mytilus galloprovincialis with two 5S rRNA genes with interspersed nontranscribed spacer segments linked to the unit, which is not justified by their cotranscription with histone genes. Surprisingly, 3′ UTR regions of histone genes show two different mRNA termination signals, a stem-loop and a polyadenylation signal, both related to the evolution of histone gene expression patterns throughout the cell cycle. The clustered H1 histones characterized share essential features with “orphon” H1 genes, suggesting a common evolutionary origin for both histone subtypes which is supported by the reconstructed phylogeny for H1 genes. The characterization of histone genes in four additional Mytilus species revealed the presence of strong purifying selection acting among the members of the family. The chromosomal location of most of the core histone genes studied was identified by FISH close to telomeric regions in M. galloprovincialis. Further analysis on nucleotide variation would be necessary to assess if H1 proteins evolve according to the birth-and-death model of evolution and if the effect of the strong purifying selection maintaining protein homogeneity could account for the homologies detected between clustered and “orphon” variants.Xunta de Galicia; 10PX110304P

Common evolutionary origin and birth-and-death process in the replication-independent histone H1 isoforms from vertebrate and invertebrate genomes

[Abstract]The H1 histone multigene family shows the greatest diversity of isoforms among the five histone gene families, including replication-dependent (RD) and replication-independent (RI) genes, according to their expression patterns along the cell cycle and their genomic organization. Although the molecular characterization of the RI isoforms has been well documented in vertebrates, similar information is lacking in invertebrates. In this work we provide evidence for a polyadenylation signature in the Mytilus “orphon” H1 genes similar to the polyadenylation characteristic of RI H1 genes. These mussel genes, together with the sea urchin H1δ genes, are part of a lineage of invertebrate “orphon” H1 genes that share several control elements with vertebrate RI H1 genes. These control elements include the UCE element, H1-box and H4-box. We provide evidence for a functional evolution of vertebrate and invertebrate RI H1 genes, which exhibit a clustering pattern by type instead of by species, with a marked difference from the somatic variants. In addition, these genes display an extensive silent divergence at the nucleotide level which is always significantly larger than the nonsilent. It thus appears that RI and RD H1 isoforms display similar long-term evolutionary patterns, best described by the birth-and-death model of evolution. Notably, this observation is in contrast with the theoretical belief that clustered RD H1 genes evolve in a concerted manner. The split of the RI group from the main RD group must therefore have occurred before the divergence between vertebrates and invertebrates about 815 million years ago. This was the result of the transposition of H1 genes to solitary locations in the genome.Xunta de Galicia; 10PX110304Canadá. Canadian Institutes of Health Research; MOP-5771

Sleep time estimated by an actigraphy watch correlates with CSF tau in cognitively unimpaired elders: the modulatory role of APOE

There is increasing evidence of the relationship between sleep and neurodegeneration, but this knowledge is not incorporated into clinical practice yet. We aimed to test whether a basic sleep parameter, as total sleep estimated by actigraphy for 1 week, was a valid predictor of CSF Alzheimer’s Disease core biomarkers (amyloid-β-42 and –40, phosphorylated-tau-181, and total-tau) in elderly individuals, considering possible confounders and effect modifiers, particularly the APOE ε4 allele. One hundred and twenty-seven cognitively unimpaired volunteers enrolled in the Valdecilla Study for Memory and Brain Aging participated in this study. Seventy percent of the participants were women with a mean age of 65.5 years. After adjustment for covariates, reduced sleep time significantly predicted higher t-tau and p-tau. This association was mainly due to the APOE ε4 carriers. Our findings suggest that total sleep time, estimated by an actigraphy watch, is an early biomarker of tau pathology and that APOE modulates this relationship. The main limitation of this study is the limited validation of the actigraphy technology used. Sleep monitoring with wearables may be a useful and inexpensive screening test to detect early neurodegenerative changes.This work was supported by grants from the Instituto de Salud Carlos III (Fondo de Investigación Sanitario, PI08/0139, PI12/02288, PI16/01652, and PI20/01011), the JPND (DEMTEST PI11/03028), the CIBERNED, and the Siemens Healthineer