58 research outputs found

    Model wine solutions: Colour and composition changes during ageing

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    The interaction between malvidin 3-glucoside, the main anthocyanin in red wine made from Vitis vinifera grapes, and (+)-catechin and the effect on this interaction of ferric ions and acetaldehyde was examined. In the models not containing acetaldehyde losses of malvidin 3-glucoside were observed, but there were only negligible losses of catechin; no new compounds were observed. In the presence of acetaldehyde the formation of new compounds was determined by high performance liquid chromatography; this formation coincided with rapid losses in the concentrations of malvidin 3-glucoside and catechin. A molecular ion at m/z 809 was determined by FAB MS, corresponding to a dimer consisting of malvidin 3-glucoside linked to catechin by an acetaldehyde bridge, according to a mechanism previously suggested by TIMBER-LAKE and BRIDLE (1976). Concurrent with the losses in anthocyanins, qualitative and quantitative changes in visible colour were also observed, consisting of changes in the wavelength of maximum absorbance (λmax) and in maximum absorbance intensity (Amax). Models containing malvidin 3-glucoside plus catechin or catechin plus ferric ions showed a marked decrease in their λmax from 525 nm to 440 nm; there was little net effect of the ferric ions on these changes. The model containing acetaldehyde showed a large increase in Amax while the λmax showed a bathochromic shift from 524 nm to 557 nm; colour decreased after achieving a maximum and the λmax decreased slightly. Changes in colour monitored by measuring hue angle, chroma and L* value are also reported

    Model vine solutions: Caffeic acid is not an important factor in colour and composition changes during red wine aging

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    Research NoteThe effect of caffeic acid and SO, on the interaction between malvidin 3-glucoside, (+)-catechin and acetaldehyde was investigated in model wine systems. Reactions were monitored by HPLC, spectrophotometry and tristimulus colorimetry. Caffeic acid had only a marginal effect on the reactions involving the other components in these model wine solutions

    Yield of array-CGH analysis in Tunisian children with autism spectrum disorder

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    Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder with strong genetic underpinnings. Microarray-based comparative genomic hybridization (aCGH) technology has been proposed as a first-level test in the genetic diagnosis of ASD and of neurodevelopmental disorders in general. Methods: We performed aCGH on 98 Tunisian children (83 boys and 15 girls) diagnosed with ASD according to DSM-IV criteria. Results: “Pathogenic” or “likely pathogenic” copy number variants (CNVs) were detected in 11 (11.2%) patients, CNVs of “uncertain clinical significance” in 26 (26.5%), “likely benign” or “benign” CNVs were found in 37 (37.8%) and 24 (24.5%) patients, respectively. Gene set enrichment analysis involving genes spanning rare “pathogenic,” “likely pathogenic,” or “uncertain clinical significance” CNVs, as well as SFARI database “autism genes” in common CNVs, detected eight neuronal Gene Ontology classes among the top 10 most significant, including synapse, neuron differentiation, synaptic signaling, neurogenesis, and others. Similar results were obtained performing g: Profiler analysis. Neither transcriptional regulation nor immune pathways reached significance. Conclusions: aCGH confirms its sizable diagnostic yield in a novel sample of autistic children from North Africa. Recruitment of additional families is under way, to verify whether genetic contributions to ASD in the Tunisian population, differently from other ethnic groups, may involve primarily neuronal genes, more than transcriptional regulation and immune-related pathways

    Phenotypic spectrum of NRXN1 mono- and bi-allelic deficiency: A systematic review

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    Neurexins are presynaptic cell adhesion molecules critically involved in synaptogenesis and vesicular neurotransmitter release. They are encoded by three genes (NRXN1-3), each yielding a longer alpha (α) and a shorter beta (β) transcript. Deletions spanning the promoter and the initial exons of the NRXN1 gene, located in chromosome 2p16.3, are associated with a variety of neurodevelopmental, psychiatric, neurological and neuropsychological phenotypes. We have performed a systematic review to define (a) the clinical phenotypes most associated with mono-allelic exonic NRXN1 deletions, and (b) the phenotypic features of NRXN1 bi-allelic deficiency due to compound heterozygous deletions/mutations. Clinically, three major conclusions can be drawn: (a) incomplete penetrance and pleiotropy do not allow reliable predictions of clinical outcome following prenatal detection of mono-allelic exonic NRXN1 deletions. Newborn carriers should undergo periodic neuro-behavioral observations for the timely detection of warning signs and the prescription of early behavioral intervention; (b) the presence of additional independent genetic risk factors should always be sought, as they may influence prognosis; (c) children with exonic NRXN1 deletions displaying early-onset, severe psychomotor delay in the context of a Pitt-Hopkins-like syndrome 2 phenotype, should undergo DNA sequencing of the spared NRXN1 allele in search for mutations or very small insertions/deletions

    Analyzing sensory data using non-linear preference learning with feature subset selection

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    15th European Conference on Machine Learning, Pisa, Italy, September 20-24, 2004The quality of food can be assessed from different points of view. In this paper, we deal with those aspects that can be appreciated through sensory impressions. When we are aiming to induce a function that maps object descriptions into ratings, we must consider that consumers’ ratings are just a way to express their preferences about the products presented in the same testing session. Therefore, we postulate to learn from consumers’ preference judgments instead of using an approach based on regression. This requires the use of special purpose kernels and feature subset selection methods. We illustrate the benefits of our approach in two families of real-world data base

    Molecular Etiology Disclosed by Array CGH in Patients With Silver–Russell Syndrome or Similar Phenotypes

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    Introduction: Silver-Russell syndrome (SRS) is an imprinting disorder primarily caused by genetic and epigenetic aberrations on chromosomes 11 and 7. SRS is a rare growth retardation disorder often misdiagnosed due to its heterogeneous and non-specific clinical features. The Netchine-Harbison clinical scoring system (NH-CSS) is the recommended tool for differentiating patients into clinical SRS or unlikely SRS. However, the clinical diagnosis is molecularly confirmed only in about 60% of patients, leaving the remaining substantial proportion of SRS patients with unknown genetic etiology. Materials and Methods: A cohort of 34 Italian patients with SRS or SRS-like features scored according to the NH-CSS and without any SRS-associated (epi)genetic alterations was analyzed by high-resolution array-based comparative genomic hybridization (CGH) in order to identify potentially pathogenic copy number variants (CNVs). Results and Discussion: In seven patients, making up 21% of the initial cohort, five pathogenic and two potentially pathogenic CNVs were found involving distinct genomic regions either previously associated with growth delay conditions (1q24.3-q25.3, 17p13.3, 17q22, and 22q11.2-q11.22) and with SRS spectrum (7p12.1 and 7p15.3-p14.3) or outlined for the first time (19q13.42), providing a better definition of reported and as yet unreported SRS overlapping syndromes. All the variants involve genes with a defined role in growth pathways, and for two genes mapping at 7p, IGF2BP3 and GRB10, the association with SRS turns out to be reinforced. The deleterious effect of the two potentially pathogenic variants, comprising GRB10 and ZNF331 genes, was explored by targeted approaches, though further studies are needed to validate their pathogenic role in the SRS etiology. In conclusion, we reconfirm the utility of performing a genome-wide scan to achieve a differential diagnosis in patients with SRS or similar features and to highlight novel chromosome alterations associated with SRS and growth retardation disorders
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