137 research outputs found

    GeneBase 1.1: a tool to summarize data from NCBI gene datasets and its application to an update of human gene statistics

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    We release GeneBase 1.1, a local tool with a graphical interface useful for parsing, structuring and indexing data from the National Center for Biotechnology Information (NCBI) Gene data bank. Compared to its predecessor GeneBase (1.0), GeneBase 1.1 now allows dynamic calculation and summarization in terms of median, mean, standard deviation and total for many quantitative parameters associated with genes, gene transcripts and gene features (exons, introns, coding sequences, untranslated regions). GeneBase 1.1 thus offers the opportunity to perform analyses of the main gene structure parameters also following the search for any set of genes with the desired characteristics, allowing unique functionalities not provided by the NCBI Gene itself. In order to show the potential of our tool for local parsing, structuring and dynamic summarizing of publicly available databases for data retrieval, analysis and testing of biological hypotheses, we provide as a sample application a revised set of statistics for human nuclear genes, gene transcripts and gene features. In contrast with previous estimations strongly underestimating the length of human genes, a 'mean' human protein-coding gene is 67 kbp long, has eleven 309\u2009bp long exons and ten 6355\u2009bp long introns. Median, mean and extreme values are provided for many other features offering an updated reference source for human genome studies, data useful to set parameters for bioinformatic tools and interesting clues to the biomedical meaning of the gene features themselves.Database URL: http://apollo11.isto.unibo.it/software/

    Systematic analysis of mRNA 5' coding sequence incompleteness in Danio rerio: an automated EST-based approach

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    <p>Abstract</p> <p>Background</p> <p>All standard methods for cDNA cloning are affected by a potential inability to effectively clone the 5' region of mRNA. The aim of this work was to estimate mRNA open reading frame (ORF) 5' region sequence completeness in the model organism <it>Danio rerio </it>(zebrafish).</p> <p>Results</p> <p>We implemented a novel automated approach (<it>5'_ORF_Extender</it>) that systematically compares available expressed sequence tags (ESTs) with all the zebrafish experimentally determined mRNA sequences, identifies additional sequence stretches at 5' region and scans for the presence of all conditions needed to define a new, extended putative ORF. Our software was able to identify 285 (3.3%) mRNAs with putatively incomplete ORFs at 5' region and, in three example cases selected (<it>selt1a</it>, <it>unc119.2</it>, <it>nppa</it>), the extended coding region at 5' end was cloned by reverse transcription-polymerase chain reaction (RT-PCR).</p> <p>Conclusion</p> <p>The implemented method, which could also be useful for the analysis of other genomes, allowed us to describe the relevance of the "5' end mRNA artifact" problem for genomic annotation and functional genomic experiment design in zebrafish.</p> <p>Open peer review</p> <p>This article was reviewed by Alexey V. Kochetov (nominated by Mikhail Gelfand), Shamil Sunyaev, and Gáspár Jékely. For the full reviews, please go to the Reviewers' Comments section.</p

    Adolescent idiopathic scoliosis screening: Could a school-based assessment protocol be useful for an early diagnosis?

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    BACKGROUND: Adolescent idiopathic scoliosis screening still needs a considerable implementation, particularly throughout a school-based assessment protocol. OBJECTIVE: This study aims to evaluate the effectiveness of clinical examinations currently in use for the diagnosis of adolescent idiopathic scoliosis, through a survey carried out in secondary schools to standardize a screening protocol that could be generalized. METHODS: In their classrooms, the adolescents underwent an idiopathic scoliosis screening through three examinations: Adam’s test, axial trunk rotation (ATR) and plumb line. In case of single positivity to one of the three examinations, a column X-ray examination was recommended. RESULTS: The sensitivity and diagnostic specificity of Adam’s test or ATR were 56.3% and 92.7%, respectively. The positivity to at least one between ATR or plumb line showed that sensitivity was higher than specificity: 91.3% versus 80.8%; the positivity to at least one between Adams’s test or plumb line showed a sensitivity of 95.2% and a specificity of 81.5%. Finally, the positivity to all three examinations showed an increase in specificity (99.7%). CONCLUSIONS: Taken together, our findings show that this school-based screening protocol had a very high specificity in early diagnosis of adolescent idiopathic scoliosis

    Uncertainty principle of genetic information in a living cell

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    BACKGROUND: Formal description of a cell's genetic information should provide the number of DNA molecules in that cell and their complete nucleotide sequences. We pose the formal problem: can the genome sequence forming the genotype of a given living cell be known with absolute certainty so that the cell's behaviour (phenotype) can be correlated to that genetic information? To answer this question, we propose a series of thought experiments. RESULTS: We show that the genome sequence of any actual living cell cannot physically be known with absolute certainty, independently of the method used. There is an associated uncertainty, in terms of base pairs, equal to or greater than ÎĽs (where ÎĽ is the mutation rate of the cell type and s is the cell's genome size). CONCLUSION: This finding establishes an "uncertainty principle" in genetics for the first time, and its analogy with the Heisenberg uncertainty principle in physics is discussed. The genetic information that makes living cells work is thus better represented by a probabilistic model rather than as a completely defined object

    Systematic reanalysis of partial trisomy 21 cases with or without Down syndrome suggests a small region on 21q22.13 as critical to the phenotype

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    A "Down Syndrome critical region" (DSCR) sufficient to induce the most constant phenotypes of Down syndrome (DS) had been identified by studying partial (segmental) trisomy 21 (PT21) as an interval of 0.6-8.3 Mb within human chromosome 21 (Hsa21), although its existence was later questioned. We propose an innovative, systematic reanalysis of all described PT21 cases (from 1973 to 2015). In particular, we built an integrated, comparative map from 125 cases with or without DS fulfilling stringent cytogenetic and clinical criteria. The map allowed to define or exclude as candidates for DS fine Hsa21 sequence intervals, also integrating duplication copy number variants (CNVs) data. A highly restricted DSCR (HR-DSCR) of only 34 kb on distal 21q22.13 has been identified as the minimal region whose duplication is shared by all DS subjects and is absent in all non-DS subjects. Also being spared by any duplication CNV in healthy subjects, HR-DSCR is proposed as a candidate for the typical DS features, the intellectual disability and some facial phenotypes. HR-DSCR contains no known gene and has relevant homology only to the chimpanzee genome. Searching for HR-DSCR functional loci might become a priority for understanding the fundamental genotype-phenotype relationships in DS

    Sequence, "subtle" alternative splicing and expression of the CYYR1 (cysteine/tyrosine-rich 1) mRNA in human neuroendocrine tumors

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    BACKGROUND: CYYR1 is a recently identified gene located on human chromosome 21 whose product has no similarity to any known protein and is of unknown function. Analysis of expressed sequence tags (ESTs) have revealed high human CYYR1 expression in cells belonging to the diffuse neuroendocrine system (DNES). These cells may be the origin of neuroendocrine (NE) tumors. The aim of this study was to conduct an initial analysis of sequence, splicing and expression of the CYYR1 mRNA in human NE tumors. METHODS: The CYYR1 mRNA coding sequence (CDS) was studied in 32 NE tumors by RT-PCR and sequence analysis. A subtle alternative splicing was identified generating two isoforms of CYYR1 mRNA differing in terms of the absence (CAG(- )isoform, the first described mRNA for CYYR1 locus) or the presence (CAG(+ )isoform) of a CAG codon. When present, this specific codon determines the presence of an alanine residue, at the exon 3/exon 4 junction of the CYYR1 mRNA. The two mRNA isoform amounts were determined by quantitative relative RT-PCR in 29 NE tumors, 2 non-neuroendocrine tumors and 10 normal tissues. A bioinformatic analysis was performed to search for the existence of the two CYYR1 isoforms in other species. RESULTS: The CYYR1 CDS did not show differences compared to the reference sequence in any of the samples, with the exception of an NE tumor arising in the neck region. Sequence analysis of this tumor identified a change in the CDS 333 position (T instead of C), leading to the amino acid mutation P111S. NE tumor samples showed no significant difference in either CYYR1 CAG(- )or CAG(+ )isoform expression compared to control tissues. CYYR1 CAG(- )isoform was significantly more expressed than CAG(+ )isoform in NE tumors as well as in control samples investigated. Bioinformatic analysis revealed that only the genomic sequence of Pan troglodytes CYYR1 is consistent with the possible existence of the two described mRNA isoforms. CONCLUSION: A new "subtle" splicing isoform (CAG(+)) of CYYR1 mRNA, the sequence and the expression of this gene were defined in a large series of NE tumors

    La personalidad jurĂ­dica internacional

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    Powerpoint del Tema 4 de la asignatura "Derecho Internacional PĂşblico". Curso 2017-2018.Tema 4. La personalidad jurĂ­dica internacional. 1. Significado y adquisiciĂłn de la personalidad jurĂ­dica internacional. 2. Sujetos consagrados: los Estados y las Organizaciones Internacionales. 3. Sujetos controvertidos: entidades polĂ­ticas y entidades religiosas. 4. Otros actores internacionales: las empresas multinacionales y las organizaciones no gubernamentales. 5. La condiciĂłn del individuo en el Derecho Internacional

    Partial trisomy 21 with or without highly restricted Down syndrome critical region (HR-DSCR): report of two new cases and reanalysis of the genotype-phenotype association

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    Background: Down syndrome (DS) is caused by the presence of an extra copy of full or partial human chromosome 21 (Hsa21). Partial (segmental) trisomy 21 (PT21) is the duplication of only a delimited region of Hsa21 and can be associated or not to DS: the study of PT21 cases is an invaluable model for addressing genotype-phenotype correlation in DS. Previous works reported systematic reanalyses of 132 subjects with PT21 and allowed the identification of a 34-kb highly restricted DS critical region (HR-DSCR) as the minimal region whose duplication is shared by all PT21 subjects diagnosed with DS. Methods: We report clinical data and cytogenetic analysis of two children with PT21, one with DS and the other without DS. Moreover, we performed a systematic bibliographic search for any new PT21 report. Results: Clinical and cytogenetic analyses of the two PT21 children have been reported: in Case 1 the duplication involves the whole long arm of Hsa21, except for the last 2.7&nbsp;Mb, which are deleted as a consequence of an isodicentric 21: the HR-DSCR is within the duplicated regions and the child is diagnosed with DS. In Case 2 the duplication involves 7.1&nbsp;Mb of distal 21q22, with a deletion of 2.1&nbsp;Mb of proximal 20p, as a consequence of an unbalanced translocation: the HR-DSCR is not duplicated and the child presents with psychomotor development delay but no clinical signs of DS. Furthermore, two PT21 reports recently published (named Case 3 and 4) have been discussed: Case 3 has DS diagnosis, nearly full trisomy for Hsa21 and a monosomy for the 21q22.3 region. Case 4 is a baby without DS and a 0.56-Mb duplication of 21q22.3. Genotype-phenotype correlation confirmed the presence of three copies of the HR-DSCR in all DS subjects and two copies in all non-DS individuals. Conclusions: The results presented here are fully consistent with the hypothesis that the HR-DSCR is critically associated with DS diagnosis. No exception to this pathogenetic model was found. Further studies are needed to detect genetic determinants likely located in the HR-DSCR and possibly responsible for core DS features, in particular intellectual disability

    One-carbon pathway metabolites are altered in the plasma of subjects with Down syndrome: Relation to chromosomal dosage

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    Introduction: Down syndrome (DS) is the most common chromosomal disorder and it is caused by trisomy of chromosome 21 (Hsa21). Subjects with DS show a large heterogeneity of phenotypes and the most constant clinical features present are typical facies and intellectual disability (ID). Several studies demonstrated that trisomy 21 causes an alteration in the metabolic profile, involving among all the one-carbon cycle. Methods: We performed enzyme-linked immunosorbent assays (ELISAs) to identify the concentration of 5 different intermediates of the one-carbon cycle in plasma samples obtained from a total of 164 subjects with DS compared to 54 euploid subjects. We investigated: tetrahydrofolate (THF; DS n = 108, control n = 41), 5-methyltetrahydrofolate (5-methyl-THF; DS n = 140, control n = 34), 5-formyltetrahydrofolate (5-formyl-THF; DS n = 80, control n = 21), S-adenosyl-homocysteine (SAH; DS n = 94, control n = 20) and S-adenosyl-methionine (SAM; DS n = 24, control n = 15). Results: Results highlight specific alterations of THF with a median concentration ratio DS/control of 2:3, a decrease of a necessary molecule perfectly consistent with a chromosomal dosage effect. Moreover, SAM and SAH show a ratio DS/control of 1.82:1 and 3.6:1, respectively. Discussion: The relevance of these results for the biology of intelligence and its impairment in trisomy 21 is discussed, leading to the final proposal of 5-methyl-THF as the best candidate for a clinical trial aimed at restoring the dysregulation of one-carbon cycle in trisomy 21, possibly improving cognitive skills of subjects with DS
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