3,653 research outputs found

    Biochemical data from the characterization of a new pathogenic mutation of human pyridoxine-5'-phosphate oxidase (PNPO)

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    PNPO deficiency is responsible of severe neonatal encephalopathy, responsive to pyridoxal-5’-phosphate (PLP) or pyridoxine. Recent studies widened the phenotype of this condition and detected new genetic variants on PNPO gene, whose pathogenetic role and clinical expression remain to be established. One of these mutations, Arg116Gln, is of particular interest because of its later onset of symptoms (beyond the first months of life) and its peculiar epileptic manifestations in patients. This protein variant was expressed as recombinant protein in E coli, purified to homogeneity, and characterized with respect to structural and kinetic properties, stability, binding constants of cofactor flavin mononucleotide (FMN) and product (PLP) in order to define the molecular and structural bases of its pathogenicity. For interpretation and discussion of reported data, together with the description of clinical studies, refer to the article [7][1] (doi: 10.1016/j.ymgme.2017.08.003)

    Silver colloids as plasmonic substrates for direct label-free surface-enhanced Raman scattering analysis of DNA

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    Ultrasensitive direct SERS analysis offers a powerful analytical tool for the structural characterization and classification of nucleic acids. However, acquisition of reliable spectral fingerprints of such complex biomolecules poses important challenges. In recent years, many efforts have been devoted to overcome these limitations, mainly implementing silver colloids as plasmonic substrates. However, a reliable cross-comparison of results reported in the recent literature is extremely hard to achieve, mostly due to the broad set of different surface properties of the plasmonic nanoparticles. Herein, we perform a thorough investigation of the role played by the metal/liquid interface composition of silver colloids in the direct label-free SERS analysis of DNA. Target molecules of increasing complexity, from short homopolymeric strands to long genomic duplexes, were used as probes. We demonstrate how apparently subtle changes in the colloidal surface chemistry can dramatically modify the affinity and the final SERS spectral profile of DNA. This has significant implications for the future design of new analytical strategies for the detection of DNA using SERS without labels

    Falta de estructura genética en las poblaciones chipriotas de Alectoris chukar (Aves, Galliformes), deducida de los datos de secuenciación del ADNmt

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    The Chukar (Alectoris chukar cypriotes) is the most common game bird in Cyprus. Since 1990 the Cypriot Government has established a restocking program with captive–reared birds. However, this program has not been guaranteed by checking the genetic nature of wild and farmed samples, either in the areas controlled by the Cypriot Government or in northern Cyprus. The sequencing of both Cytochrome–b and Control Region of the mitochondrial DNA was carried out for 61 Cypriot representatives and 14 specimens of the same subspecies from Crete and Israel. Only the A. chukar maternal lineage was found. A partitioning of Cypriot specimens among different clades was not reliably supported, whereas robust bootstrap values weighted for an evolutionary divergence between Cypriot and Cretan Chukars. An overall genetic homogeny of the Cypriot populations was disclosed, whatever their status (captive vs. wild stocks) and origin (Government controlled vs. occupied areas) would be, a higher nucleotide diversity of the wild vs. captive representatives notwithstanding. Key words: Chukar, Control Region, Cytochrome–b, Genetic diversity, mtDNA, Partridges.Una subespecie de la perdiz chucar (Alectoris chukar cypriotes) es el ave de caza más común de Chipre. A partir de 1990 el gobierno chipriota estableció un programa de repoblación utilizando aves criadas en cautividad. No obstante, dicho programa no ha sido avalado mediante la comprobación de la naturaleza genética de muestras tanto de ejemplares salvajes como de granja, ni en las zonas controladas por el gobierno chipriota ni en el norte de Chipre. Se ha llevado a cabo la secuenciación del citocromo-b y de la región de control del ADN mitocondrial de 61 ejemplares chipriotas y de 14 especimenes de la misma subespecie de Creta y de Israel. Sólo se encontró el linaje materno de A. chukar. No se pudo demostrar con fiabilidad el reparto de los especimenes chipriotas en distintos clados, mientras que unos valores bootstrap muy consistentes sustentaban una divergencia evolutiva entre las perdices chucar chipriotas y cretenses. Se reveló la existencia de una homogeneidad genética en las poblaciones chipriotas, cualquiera que fuera su estatus (linajes cautivos frente a salvajes) o su origen (zonas controladas por el gobierno frente a zonas ocupadas), por más que se diera una mayor diversidad de nucleótidos de los ejemplares salvajes frente a los cautivos. Palabras clave: Perdiz chucar, Región de control, Citocromo-b, Diversidad genética, ADNmt, Perdices

    Heparin and Heparan Sulfate: Analyzing Structure and Microheterogeneity [chapter]

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    available in PMC 2013 August 28The structural microheterogeneity of heparin and heparan sulfate is one of the major reasons for the multifunctionality exhibited by this class of molecules. In a physiological context, these molecules primarily exert their effects extracellularly by mediating key processes of cellular cross-talk and signaling leading to the modulation of a number of different biological activities including development, cell proliferation, and inflammation. This structural diversity is biosynthetically imprinted in a nontemplate-driven manner and may also be dynamically remodeled as cellular function changes. Understanding the structural information encoded in these molecules forms the basis for attempting to understand the complex biology they mediate. This chapter provides an overview of the origin of the structural microheterogeneity observed in heparin and heparan sulfate, and the orthogonal analytical methodologies that are required to help decipher this information

    The ‘Accademia dei Lincei’ and the New World.

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    Pengendalian Frekuensi Dengan Menggunakan Kontrol Fuzzy Prediktif Pada Simulator Plant Turbin-Generator Pada PLTU

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    Sistem pembangkit dirasakan sangat perlu guna memenuhi kebutuhan tenaga listrik yang semakin meningkat, kestabilan sangat dibutuhkan pada proses pembangkit sehingga sistem pengendalian digunakan untuk menjaga variabel proses tersebut tetap stabil. Salah satunya adalah dengan melakukan pengendali frekuensi pada tubin-generator suatu pembangkit listik, contohnya PLTU (Pembangkit Listrik Tenaga Uap). Frekuensi dari turbin uap harus dijaga kestabilannya agar keluaran daya listrik di generator berjalan dengan baik. Fluktuasi frekuensi adalah salah satu kendala penyampaian daya listrik ke beban, juga waktu kembali yang tidak segera ke kondisi normal akan mengakibatkan kerusakan pada sistem seperti patahnya poros turbin-generator dan kemungkinan terjadi gangguan pada jaringan listrik, sehingga perlu dilakukan pengaturan laju aliran uap yang masuk ke turbin. Kontroler yang digunakan untuk menjaga Perubahan frekuensi adalah kontrol fuzzy prediktif, dengan penambahan gain K1 pada kontrol fuzzy prediktif sebesar 42.35 yang bekerja secara sucsessive kontroler ini dapat mengurangi error sebesar 1,04% jika sistem hanya menggunakan kontroler fuzzy pada saat terjadi Perubahan beban

    Diagnostic Targeted Resequencing in 349 Patients with Drug-Resistant Pediatric Epilepsies Identifies Causative Mutations in 30 Different Genes

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    Targeted resequencing gene panels are used in the diagnostic setting to identify gene defects in epilepsy. We performed targeted resequencing using a 30-genes panel and a 95-genes panel in 349 patients with drug-resistant epilepsies beginning in the first years of life. We identified 71 pathogenic variants, 42 of which novel, in 30 genes, corresponding to 20.3% of the probands. In 66% of mutation positive patients, epilepsy onset occurred before the age of 6 months. The 95-genes panel allowed a genetic diagnosis in 22 (6.3%) patients that would have otherwise been missed using the 30-gene panel. About 50% of mutations were identified in genes coding for sodium and potassium channel components. SCN2A was the most frequently mutated gene followed by SCN1A, KCNQ2, STXBP1, SCN8A, CDKL5, and MECP2. Twenty-nine mutations were identified in 23 additional genes, most of them recently associated with epilepsy. Our data show that panels targeting about 100 genes represent the best cost-effective diagnostic option in pediatric drug-resistant epilepsies. They enable molecular diagnosis of atypical phenotypes, allowing to broaden phenotype-genotype correlations. Molecular diagnosis might influence patients' management and translate into better and specific treatment recommendations in some conditions

    Whole-brain histogram and voxel-based analyses of apparent diffusion coefficient and magnetization transfer ratio in celiac disease, epilepsy, and cerebral calcifications syndrome

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    BACKGROUND AND PURPOSE: Diffusion and magnetization transfer (MT) techniques have been applied to the investigation with MR of epilepsy and have revealed changes in patients with or without abnormalities on MR imaging. We hypothesized that also in the coeliac disease (CD), epilepsy and cerebral calcifications (CEC) syndrome diffusion and MT techniques could reveal brain abnormalities undetected by MR imaging and tentatively correlated to epilepsy. MATERIALS AND METHODS: Diffusion and MT weighted images were obtained in 10 patients with CEC, 8 patients with CD without epilepsy and 17 healthy volunteers. The whole brain apparent diffusion coefficient (ADC) and MT ratio (MTR) maps were analyzed with histograms and the Statistical Parametric Mapping 2 (SPM2) software. We employed the non-parametric Mann-Whitney U test to assess differences for ADC and MTR histogram metrics. Voxel by voxel comparison of the ADC and MTR maps was performed with 2 tails t-test corrected for multiple comparison. RESULTS: A significantly higher whole brain ADC value as compared to healthy controls was observed in CEC (P = 0.006) and CD (P = 0.01) patients. SPM2 showed bilateral areas of significantly decreased MTR in the parietal and temporal subcortical white matter (WM) in the CEC patients. CONCLUSION: Our study indicates that diffusion and MT techniques are also capable of revealing abnormalities undetected by MR imaging. In particular patients with CEC syndrome show an increase of the whole brain ADC histogram which is more pronounced than in patients with gluten intolerance. IN CEC patients, voxel-based analysis demonstrates a localized decrease of the MTR in the parieto-temporal subcortical WM
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