365 research outputs found

    FRA2A is a CGG repeat expansion associated with silencing of AFF3

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    Folate-sensitive fragile sites (FSFS) are a rare cytogenetically visible subset of dynamic mutations. Of the eight molecularly characterized FSFS, four are associated with intellectual disability (ID). Cytogenetic expression results from CGG tri-nucleotide-repeat expansion mutation associated with local CpG hypermethylation and transcriptional silencing. The best studied is the FRAXA site in the FMR1 gene, where large expansions cause fragile X syndrome, the most common inherited ID syndrome. Here we studied three families with FRA2A expression at 2q11 associated with a wide spectrum of neurodevelopmental phenotypes. We identified a polymorphic CGG repeat in a conserved, brain-active alternative promoter of the AFF3 gene, an autosomal homolog of the X-linked AFF2/FMR2 gene: Expansion of the AFF2 CGG repeat causes FRAXE ID. We found that FRA2A-expressing individuals have mosaic expansions of the AFF3 CGG repeat in the range of several hundred repeat units. Moreover, bisulfite sequencing and pyrosequencing both suggest AFF3 promoter hypermethylation. cSNP-analysis demonstrates monoallelic expression of the AFF3 gene in FRA2A carriers thus predicting that FRA2A expression results in functional haploinsufficiency for AFF3 at least in a subset of tissues. By whole-mount in situ hybridization the mouse AFF3 ortholog shows strong regional expression in the developing brain, somites and limb buds in 9.5-12.5dpc mouse embryos. Our data suggest that there may be an association between FRA2A and a delay in the acquisition of motor and language skills in the families studied here. However, additional cases are required to firmly establish a causal relationship

    Naphthoquinone Derivatives Exert Their Antitrypanosomal Activity via a Multi-Target Mechanism

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    BACKGROUND AND METHODOLOGY: Recently, we reported on a new class of naphthoquinone derivatives showing a promising anti-trypanosomatid profile in cell-based experiments. The lead of this series (B6, 2-phenoxy-1,4-naphthoquinone) showed an ED(50) of 80 nM against Trypanosoma brucei rhodesiense, and a selectivity index of 74 with respect to mammalian cells. A multitarget profile for this compound is easily conceivable, because quinones, as natural products, serve plants as potent defense chemicals with an intrinsic multifunctional mechanism of action. To disclose such a multitarget profile of B6, we exploited a chemical proteomics approach. PRINCIPAL FINDINGS: A functionalized congener of B6 was immobilized on a solid matrix and used to isolate target proteins from Trypanosoma brucei lysates. Mass analysis delivered two enzymes, i.e. glycosomal glycerol kinase and glycosomal glyceraldehyde-3-phosphate dehydrogenase, as potential molecular targets for B6. Both enzymes were recombinantly expressed and purified, and used for chemical validation. Indeed, B6 was able to inhibit both enzymes with IC(50) values in the micromolar range. The multifunctional profile was further characterized in experiments using permeabilized Trypanosoma brucei cells and mitochondrial cell fractions. It turned out that B6 was also able to generate oxygen radicals, a mechanism that may additionally contribute to its observed potent trypanocidal activity. CONCLUSIONS AND SIGNIFICANCE: Overall, B6 showed a multitarget mechanism of action, which provides a molecular explanation of its promising anti-trypanosomatid activity. Furthermore, the forward chemical genetics approach here applied may be viable in the molecular characterization of novel multitarget ligands

    CARACTERIZAÇÃO E AVALIAÇÃO SENSORIAL DE SORVETE COM EXTRATO AQUOSO DE YACON

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    O yacon está sendo considerado um alimento nutracêutico em decorrência dos estudos sobre a diminuição dos níveis de açúcar no sangue após seu consumo repetido por de ser rico em fibras alimentares, especialmente as solúveis ou viscosas, dentre elas inulina e Frutoligossacarídeos (FOS). O crescente aumento da busca no mercado por produtos que apresentem, além de qualidade sensorial e nutricional, benefícios associados à saúde faz com que as pesquisas nesse ramo cresçam. Com isso, o objetivo do trabalho foi elaborar e avaliar um sorvete com extrato aquoso de yacon em diferentes concentrações. Foram elaboradas duas amostras (F1 com adição de 5% de extrato de yacon e F2 com 10%) e realizaram-se análises de composição centesimal (umidade, cinzas, proteínas, lipídeos e carboidratos) e sensoriais (escala hedônica para cor, sabor, textura, aroma e aspecto global), cor e textura instrumental. A composição centesimal não apresentou diferença significativa (p>0,05) para umidade, cinzas e carboidratos. O teor de proteína foi menor para F2 e o teor de lipídeo foi maior para F2. As amostras apresentaram a cor amarela clara com alta luminosidade e não diferiram significativamente na textura expressa em força de compressão. As duas formulações foram sensorialmente aceitas, não apresentando diferença significativa entre si e conferindo um alto índice de aceitação.AbstractYacon is being considered a nutraceutical food due to studies about the decrease of sugar levels in blood after its repeated consumption, and also for being rich in food fibers, specially the soluble or viscous, among them fructooligosaccharides and inulin. The increasing search in the market for products presenting beyond sensory qualities, nutritional and health benefits, makes the researches in this field grows. The goal of this task was to develop an ice cream with aqueous extract of yacon, in different concentrations. It were prepared two samples, (F1 with addition of 5% of yacon extract, and F2 with 10% of it) and were performed centesimal composition analysis (humidity, ashes, protein, lipids, carbohydrates) and sensory analysis (Hedonic scale for color, taste, texture, flavor and global aspect), beyond color and instrumental texture. The centesimal composition showed no significant difference (p> 0.05) for moisture, ash and carbohydrates. The protein content was lower for F2 and lipid content was higher for F2.Samples displayed a clear yellow coloration, with high luminosity and didn’t differ significantly in texture, expressed in compression force. The two formulations were sensory acceptable, showing no significant difference between it and confirming a high acceptance rate

    Autism as a disorder of neural information processing: directions for research and targets for therapy

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    The broad variation in phenotypes and severities within autism spectrum disorders suggests the involvement of multiple predisposing factors, interacting in complex ways with normal developmental courses and gradients. Identification of these factors, and the common developmental path into which theyfeed, is hampered bythe large degrees of convergence from causal factors to altered brain development, and divergence from abnormal brain development into altered cognition and behaviour. Genetic, neurochemical, neuroimaging and behavioural findings on autism, as well as studies of normal development and of genetic syndromes that share symptoms with autism, offer hypotheses as to the nature of causal factors and their possible effects on the structure and dynamics of neural systems. Such alterations in neural properties may in turn perturb activity-dependent development, giving rise to a complex behavioural syndrome many steps removed from the root causes. Animal models based on genetic, neurochemical, neurophysiological, and behavioural manipulations offer the possibility of exploring these developmental processes in detail, as do human studies addressing endophenotypes beyond the diagnosis itself

    Testing the FMR1 Promoter for Mosaicism in DNA Methylation among CpG Sites, Strands, and Cells in FMR1-Expressing Males with Fragile X Syndrome

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    Variability among individuals in the severity of fragile X syndrome (FXS) is influenced by epigenetic methylation mosaicism, which may also be common in other complex disorders. The epigenetic signal of dense promoter DNA methylation is usually associated with gene silencing, as was initially reported for FMR1 alleles in individuals with FXS. A paradox arose when significant levels of FMR1 mRNA were reported for some males with FXS who had been reported to have predominately methylated alleles. We have used hairpin-bisufite PCR, validated with molecular batch-stamps and barcodes, to collect and assess double-stranded DNA methylation patterns from these previously studied males. These patterns enable us to distinguish among three possible forms of methylation mosaicism, any one of which could explain FMR1 expression in these males. Our data indicate that cryptic inter-cell mosaicism in DNA methylation can account for the presence of FMR1 mRNA in some individuals with FXS

    Developmental language disorder: Early predictors, age for the diagnosis, and diagnostic tools. A scoping review

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    Background. Developmental Language Disorder (DLD) is frequent in childhood and may have long-term sequelae. By employing an evidence-based approach, this scoping review aims at identifying (a) early predictors of DLD; (b) the optimal age range for the use of screening and diagnostic tools; (c) effective diagnostic tools in preschool children. Methods. We considered systematic reviews, meta-analyses, and primary observational studies with control groups on predictive, sensitivity and specificity values of screening and diagnostic tools and psycholinguistic measures for the assessment of DLD in preschool children. We identified 37 studies, consisting of 10 systematic reviews and 27 primary studies. Results. Delay in gesture production, receptive and/or expressive vocabulary, syntactic comprehension, or word combination up to 30 months emerged as early predictors of DLD, a family history of DLD appeared to be a major risk factor, and low socioeconomic status and environmental input were reported as risk factors with lower predictive power. Optimal time for screening is suggested between age 2 and 3, for diagnosis around age 4. Because of the high variability of sensitivity and specificity values, joint use of standardized and psycholinguistic measures is suggested to increase diagnostic accuracy. Conclusions. Monitoring risk situations and employing caregivers\u2019 reports, clinical assessment and multiple linguistic measures are fundamental for an early identification of DLD and timely interventions
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