132 research outputs found

    4H Leukodystrophy: A Brain Magnetic Resonance Imaging Scoring System

    Get PDF
    4H (hypomyelination, hypodontia and hypogonadotropic hypogonadism) leukodystrophy (4H) is an autosomal recessive hypomyelinating white matter (WM) disorder with neurologic, dental, and endocrine abnormalities. The aim of this study was to develop and validate a magnetic resonance imaging (MRI) scoring system for 4H. A scoring system (0-54) was developed to quantify hypomyelination and atrophy of different brain regions. Pons diameter and bicaudate ratio were included as measures of cerebral and brainstem atrophy, and reference values were determined using controls. Five independent raters completed the scoring system in 40 brain MRI scans collected from 36 patients with genetically proven 4H. Interrater reliability (IRR) and correlations between MRI scores, age, gross motor function, gender, and mutated gene were assessed. IRR for total MRI severity was found to be excellent (intraclass correlation coefficient: 0.87; 95% confidence interval: 0.80-0.92) but varied between different items with some (e.g., myelination of the cerebellar WM) showing poor IRR. Atrophy increased with age in contrast to hypomyelination scores. MRI scores (global, hypomyelination, and atrophy scores) significantly correlated with clinical handicap (p < 0.01 for all three items) and differed between the different genotypes. Our 4H MRI scoring system reliably quantifies hypomyelination and atrophy in patients with 4H, and MRI scores reflect clinical disease severity

    Apparent diffusion coefficient restriction in the white matter: going beyond acute brain territorial ischemia

    Get PDF
    BACKGROUND: Reduction of apparent diffusion coefficient (ADC) values in white matter is not always ischaemic in nature. METHODS: We retrospectively analysed our MRI records featuring reduced ADC values in the centrum semiovale without grey matter involvement or significant vasogenic oedema. RESULTS: Several conditions showed the aforementioned MR findings: moose-horn lesions on coronal images in X-linked Charcot-Marie-Tooth disease; small fronto-parietal lesions in Menkes disease; marked signal abnormalities in the myelinised regions in the acute neonatal form of maple syrup urine disease; strip-like involvement of the corpus callosum in glutaric aciduria type 1; persistent periventricular parieto-occipital abnormalities in phenylketonuria; diffuse signal abnormalities with necrotic evolution in global cerebral anoxia or after heroin vapour inhalation; almost completely reversible symmetric fronto-parietal lesions in methotrexate neurotoxicity; chain-like lesions in watershed ischaemia; splenium involvement that normalises in reversible splenial lesions or leads to gliosis in diffuse axonal injury. CONCLUSION: Neuroradiologists must be familiar with these features, thereby preventing misdiagnosis and inappropriate management

    The Herpesvirus Associated Ubiquitin Specific Protease, USP7, Is a Negative Regulator of PML Proteins and PML Nuclear Bodies

    Get PDF
    The PML tumor suppressor is the founding component of the multiprotein nuclear structures known as PML nuclear bodies (PML-NBs), which control several cellular functions including apoptosis and antiviral effects. The ubiquitin specific protease USP7 (also called HAUSP) is known to associate with PML-NBs and to be a tight binding partner of two herpesvirus proteins that disrupt PML NBs. Here we investigated whether USP7 itself regulates PML-NBs. Silencing of USP7 was found to increase the number of PML-NBs, to increase the levels of PML protein and to inhibit PML polyubiquitylation in nasopharyngeal carcinoma cells. This effect of USP7 was independent of p53 as PML loss was observed in p53-null cells. PML-NBs disruption was induced by USP7 overexpression independently of its catalytic activity and was induced by either of the protein interaction domains of USP7, each of which localized to PML-NBs. USP7 also disrupted NBs formed from some single PML isoforms, most notably isoforms I and IV. CK2α and RNF4, which are known regulators of PML, were dispensable for USP7-associated PML-NB disruption. The results are consistent with a novel model of PML regulation where a deubiquitylase disrupts PML-NBs through recruitment of another cellular protein(s) to PML NBs, independently of its catalytic activity

    Histone H2A and H2B Are Monoubiquitinated at AID-Targeted Loci

    Get PDF
    Background: Somatic hypermutation introduces base substitutions into the rearranged and expressed immunoglobulin (Ig) variable regions to promote immunity. This pathway requires and is initiated by the Activation Induced Deaminase (AID) protein, which deaminates cytidine to produce uracils and UG mismatches at the Ig genes. Subsequent processing of uracil by mismatch repair and base excision repair factors contributes to mutagenesis. While selective for certain genomic targets, the chromatin modifications which distinguish hypermutating from non-hypermutating loci are not defined. Methodology/Principal Findings: Here, we show that AID-targeted loci in mammalian B cells contain ubiquitinated chromatin. Chromatin immunoprecipitation (ChIP) analysis of a constitutively hypermutating Burkitt\u27s B cell line, Ramos, revealed the presence of monoubiquitinated forms of both histone H2A and H2B at two AID-associated loci, but not at control loci which are expressed but not hypermutated. Similar analysis using LPS activated primary murine splenocytes showed enrichment of the expressed V(H) and S gamma 3 switch regions upon ChIP with antibody specific to AID and to monoubiquitinated H2A and H2B. In the mechanism of mammalian hypermutation, AID may interact with ubiquitinated chromatin because confocal immunofluorescence microscopy visualized AID colocalized with monoubiquitinated H2B within discrete nuclear foci. Conclusions/Significance: Our results indicate that monoubiquitinated histones accompany active somatic hypermutation, revealing part of the histone code marking AID-targeted loci. This expands the current view of the chromatin state during hypermutation by identifying a specific nucleosome architecture associated with somatic hypermutation

    Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand

    Get PDF
    Objective: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. Design: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. Methods: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. Results: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. Conclusion: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age

    Genomic variation in tomato, from wild ancestors to contemporary breeding accessions

    Get PDF
    [EN] Background: Domestication modifies the genomic variation of species. Quantifying this variation provides insights into the domestication process, facilitates the management of resources used by breeders and germplasm centers, and enables the design of experiments to associate traits with genes. We described and analyzed the genetic diversity of 1,008 tomato accessions including Solanum lycopersicum var. lycopersicum (SLL), S. lycopersicum var. cerasiforme (SLC), and S. pimpinellifolium (SP) that were genotyped using 7,720 SNPs. Additionally, we explored the allelic frequency of six loci affecting fruit weight and shape to infer patterns of selection. Results: Our results revealed a pattern of variation that strongly supported a two-step domestication process, occasional hybridization in the wild, and differentiation through human selection. These interpretations were consistent with the observed allele frequencies for the six loci affecting fruit weight and shape. Fruit weight was strongly selected in SLC in the Andean region of Ecuador and Northern Peru prior to the domestication of tomato in Mesoamerica. Alleles affecting fruit shape were differentially selected among SLL genetic subgroups. Our results also clarified the biological status of SLC. True SLC was phylogenetically positioned between SP and SLL and its fruit morphology was diverse. SLC and “cherry tomato” are not synonymous terms. The morphologically-based term “cherry tomato” included some SLC, contemporary varieties, as well as many admixtures between SP and SLL. Contemporary SLL showed a moderate increase in nucleotide diversity, when compared with vintage groups. Conclusions: This study presents a broad and detailed representation of the genomic variation in tomato. Tomato domestication seems to have followed a two step-process; a first domestication in South America and a second step in Mesoamerica. The distribution of fruit weight and shape alleles supports that domestication of SLC occurred in the Andean region. Our results also clarify the biological status of SLC as true phylogenetic group within tomato. We detect Ecuadorian and Peruvian accessions that may represent a pool of unexplored variation that could be of interest for crop improvement.We are grateful to the gene banks for their collections that made this study possible. We thank Syngenta Seeds for providing genotyping data for 42 accessions. We would like to thank the Supercomputing and Bioinnovation Center (Universidad de Malaga, Spain) for providing computational resources to process the SNAPP phylogenetic tree. This research was supported in part by the USDA/NIFA funded SolCAP project under contract number to DF and USDA AFRI 2013-67013-21229 to EvdK and DF.Blanca Postigo, JM.; Montero Pau, J.; Sauvage, C.; Bauchet, G.; Illa, E.; Díez Niclós, MJTDJ.; Francis, D.... (2015). Genomic variation in tomato, from wild ancestors to contemporary breeding accessions. BMC Genomics. 16(257):1-19. https://doi.org/10.1186/s12864-015-1444-1S11916257Tanksley SD, McCouch SR. Seed banks and molecular maps: unlocking genetic potential from the wild. Science (80-). 1997;277:1063–6.Doebley JF, Gaut BS, Smith BD. The molecular genetics of crop domestication. Cell. 2006;127:1309–21.Gepts P. A comparison between crop domestication, classical plant breeding, and genetic engineering. Crop Sci. 2002;42:1780.Weigel D, Nordborg M. Natural variation in Arabidopsis. How do we find the causal genes? Plant Physiol. 2005;138:567–8.Peralta IE, Spooner DM, Knapp S, Anderson C. Taxonomy of wild tomatoes and their relatives (Solanum sect. Lycopersicoides, sect. Juglandifolia, sect. Lycopersicon; Solanaceae). Syst Bot Monogr. 2008;84:1–186.Rick CM, Fobes JF. Allozyme variation in the cultivated tomato and closely related species. Bull Torrey Bot Club. 1975;102:376–84.Zuriaga E, Blanca J, Nuez F. Classification and phylogenetic relationships in Solanum section Lycopersicon based on AFLP and two nuclear gene sequences. Genet Resour Crop Evol. 2008;56:663–78.Zuriaga E, Blanca J, Cordero L, Sifres A, Blas-Cerdán WG, Morales R, et al. Genetic and bioclimatic variation in Solanum pimpinellifolium. Genet Resour Crop Evol. 2008;56:39–51.Blanca J, Cañizares J, Cordero L, Pascual L, Diez MJ, Nuez F. Variation revealed by SNP genotyping and morphology provides insight into the origin of the tomato. PLoS One. 2012;7:e48198.Rick CM. Natural variability in wild species of Lycopersicon and its bearing on tomato breeding. Genet Agrar. 1976;30:249–59.Rick CM, Holle M. Andean Lycopersicon esculentum var. cerasiforme: genetic variation and its evolutionary significance. Econ Bot. 1990;44:69–78.Nakazato T, Franklin RA, Kirk BC, Housworth EA. Population structure, demographic history, and evolutionary patterns of a green-fruited tomato, Solanum peruvianum (Solanaceae), revealed by spatial genetics analyses. Am J Bot. 2012;99:1207–16.Rick CM, Butler L. Cytogenetics of the Tomato. Adv Genet. 1956;8:267–382. Advances in Genetics.Jenkins JA. The origin of the cultivated tomato. Econ Bot. 1948;2:379–92.Nesbitt TC, Tanksley SD. Comparative sequencing in the genus lycopersicon: implications for the evolution of fruit size in the domestication of cultivated tomatoes. Genetics. 2002;162:365–79.Ranc N, Muños S, Santoni S, Causse M. A clarified position for Solanum lycopersicum var cerasiforme in the evolutionary history of tomatoes (solanaceae). BMC Plant Biol. 2008;8:130.De Candolle A. Origin of cultivated plants. 2nd ed. London: Trench, Paul; 1886.Miller JC, Tanksley SD. RFLP analysis of phylogenetic relationships and genetic variation in the genus Lycopersicon. Theor Appl Genet. 1990;80:437–48.Williams CE, Clair DAS. Phenetic relationships and levels of variability detected by restriction fragment length polymorphism and random amplified polymorphic DNA analysis of cultivated and wild accessions of Lycopersicon esculentum. Genome. 1993;36:619–30.Park YH, West MAL, St Clair DA. Evaluation of AFLPs for germplasm fingerprinting and assessment of genetic diversity in cultivars of tomato (Lycopersicon esculentum L). Genome. 2004;47:510–8.Sim S-C, Robbins MD, Van Deynze A, Michel AP, Francis DM. Population structure and genetic differentiation associated with breeding history and selection in tomato (Solanum lycopersicum L.). Heredity (Edinb). 2011;106:927–35.Sim S-C, Robbins MD, Chilcott C, Zhu T, Francis DM. Oligonucleotide array discovery of polymorphisms in cultivated tomato (Solanum lycopersicum L) reveals patterns of SNP variation associated with breeding. BMC Genomics. 2009;10:466.Sim S-C, Durstewitz G, Plieske J, Wieseke R, Ganal MW, Van Deynze A, et al. Development of a large SNP genotyping array and generation of high-density genetic maps in tomato. PLoS One. 2012;7:e40563.Frary A, Nesbitt TC, Grandillo S, Knaap E, Cong B, Liu J, et al. fw2.2: a quantitative trait locus key to the evolution of tomato fruit size. Science. 2000;289:85–8.Liu J, Van Eck J, Cong B, Tanksley SD. A new class of regulatory genes underlying the cause of pear-shaped tomato fruit. Proc Natl Acad Sci U S A. 2002;99:13302–6.Xiao H, Jiang N, Schaffner E, Stockinger EJ, van der Knaap E. A retrotransposon-mediated gene duplication underlies morphological variation of tomato fruit. Science. 2008;319:1527–30.Cong B, Barrero LS, Tanksley SD. Regulatory change in YABBY-like transcription factor led to evolution of extreme fruit size during tomato domestication. Nat Genet. 2008;40:800–4.Muños S, Ranc N, Botton E, Bérard A, Rolland S, Duffé P, et al. Increase in tomato locule number is controlled by two single-nucleotide polymorphisms located near WUSCHEL. Plant Physiol. 2011;156:2244–54.Chakrabarti M, Zhang N, Sauvage C, Muños S, Blanca J, Cañizares J, et al. A cytochrome P450 regulates a domestication trait in cultivated tomato. Proc Natl Acad Sci U S A. 2013;110:17125–30.Rodríguez GR, Muños S, Anderson C, Sim S-C, Michel A, Causse M, et al. Distribution of SUN, OVATE, LC, and FAS in the tomato germplasm and the relationship to fruit shape diversity. Plant Physiol. 2011;156:275–85.Sim S-C, Van Deynze A, Stoffel K, Douches DS, Zarka D, Ganal MW, et al. High-density SNP genotyping of tomato (Solanum lycopersicum L) reveals patterns of genetic variation due to breeding. PLoS One. 2012;7:e45520.Sauvage C, Segura V, Bauchet G, Stevens R, Thi Do P, Nikoloski Z, et al. Genome Wide Association in tomato reveals 44 candidate loci for fruit metabolic traits. Plant Physiol. 2014;165:1120–32.Hamilton JP, Sim S-C, Stoffel K, Van Deynze A, Buell CR, Francis DM. Single nucleotide polymorphism discovery in cultivated tomato via sequencing by synthesis. Plant Genome J. 2012;5:17.Patterson NJ, Price AL, Reich D. Population structure and eigenanalysis. PLoS Genet. 2006;2:e190.Price AL, Patterson NJ, Plenge RM, Weinblatt ME, Shadick NA, Reich D. Principal components analysis corrects for stratification in genome-wide association studies. Nat Genet. 2006;38:904–9.Kosman E, Leonard KJ. Similarity coefficients for molecular markers in studies of genetic relationships between individuals for haploid, diploid, and polyploid species. Mol Ecol. 2005;14:415–24.Adler D. vioplot: Violin plot. 2005.Jost L. Gst and its relatives do not measure differentiation. Mol Ecol. 2008;17:4015–26.Excoffier L, Lischer H. Arlequin suite ver 3.5: A new series of programs to perform population genetics analyses under Linux and Windows. Mol Ecol Resour. 2010;10:564–7.Huson DH, Bryant D. Application of phylogenetic networks in evolutionary studies. Mol Ecol Evol. 2006;23:254–67.Knight R, Maxwell P, Birmingham A, Carnes J, Caporaso JG, Easton BC, et al. PyCogent: a toolkit for making sense from sequence. Genome Biol. 2007;8:R171.Szpiech ZA, Jakobsson M, Rosenberg NA. ADZE: a rarefaction approach for counting alleles private to combinations of populations. Bioinformatics. 2008;24:2498–504.Bradbury PJ, Zhang Z, Kroon DE, Casstevens TM, Ramdoss Y, Buckler ES. TASSEL: software for association mapping of complex traits in diverse samples. Bioinformatics. 2007;23:2633–5.Cleveland WS. Robust locally weighted regression and smoothing scatterplots. J Am Stat Assoc. 1979;74:829.R Core Team. R: A Language and Environment for Statistical Computing. 2013.Sinnot RS. Virtues of the haversine. Sky Telesc. 1984;68:159.Hijmans RJ, Etten JV. raster: Geographic data analysis and Modeling. 2013.Bryant D, Bouckaert R, Felsenstein J, Rosenberg NA, RoyChoudhury A. Inferring species trees directly from biallelic genetic markers: bypassing gene trees in a full coalescent analysis. Mol Biol Evol. 2012;29:1917–32.Drummond AJ, Rambaut A. BEAST: Bayesian evolutionary analysis by sampling trees. BMC Evol Biol. 2007;7:214.Rambaut A. Tracer v.1.5. 2009.Huang Z, van der Knaap E. Tomato fruit weight 11.3 maps close to fasciated on the bottom of chromosome 11. Theor Appl Genet. 2011;123:465–74.Guo M, Rupe MA, Dieter JA, Zou J, Spielbauer D, Duncan KE, et al. Cell Number Regulator1 affects plant and organ size in maize: implications for crop yield enhancement and heterosis. Plant Cell. 2010;22:1057–73.Sambrook J, Fritsch EF, Maniatis T. Molecular cloning. New York: Cold Spring Harbor Laboratory Press; 1989.Lin T, Zhu G, Zhang J, Xu X, Yu Q, Zheng Z, et al. Genomic analyses provide insights into the history of tomato breeding. Nat Genet. 2014;46:1220–6.Platt A, Horton M, Huang YS, Li Y, Anastasio AE, Mulyati NW, et al. The scale of population structure in Arabidopsis thaliana. PLoS Genet. 2010;6:e1000843.Pressoir G, Berthaud J. Patterns of population structure in maize landraces from the Central Valleys of Oaxaca in Mexico. Heredity (Edinb). 2004;92:88–94.Koenig D, Jiménez-Gómez JM, Kimura S, Fulop D, Chitwood DH, Headland LR, et al. Comparative transcriptomics reveals patterns of selection in domesticated and wild tomato. Proc Natl Acad Sci U S A. 2013;110:e2655–62.Nakazato T, Housworth EA. Spatial genetics of wild tomato species reveals roles of the Andean geography on demographic history. Am J Bot. 2011;98:88–98.United States. Office of Experimental Stations. Experimental Station Recod, Volumen 39. Volume 39. Washington, DC, USA: United States. Office of Experimental Stations; 1918.Merk HL, Yames SC, Van Deynze A, Tong N, Menda N, Mueller LA, et al. Trait diversity and potential for selection indeces based on variation among regionally adapted processing tomato germplasm. J Am Soc Hortic Sci. 2012;137:427–37

    Molecular basis of USP7 inhibition by selective small-molecule inhibitors

    Get PDF
    Ubiquitination controls the stability of most cellular proteins, and its deregulation contributes to human diseases including cancer. Deubiquitinases remove ubiquitin from proteins, and their inhibition can induce the degradation of selected proteins, potentially including otherwise 'undruggable' targets. For example, the inhibition of ubiquitin-specific protease 7 (USP7) results in the degradation of the oncogenic E3 ligase MDM2, and leads to re-activation of the tumour suppressor p53 in various cancers. Here we report that two compounds, FT671 and FT827, inhibit USP7 with high affinity and specificity in vitro and within human cells. Co-crystal structures reveal that both compounds target a dynamic pocket near the catalytic centre of the auto-inhibited apo form of USP7, which differs from other USP deubiquitinases. Consistent with USP7 target engagement in cells, FT671 destabilizes USP7 substrates including MDM2, increases levels of p53, and results in the transcription of p53 target genes, induction of the tumour suppressor p21, and inhibition of tumour growth in mice

    Criteria Document Fluorides

    No full text
    De engelse versie van dit rapport is verschenen onder nummer 758474010. Bij dit rapport behoort een appendix getiteld: &quot;Integrated Criteria Document Florides Effects&quot;, met nummer 758474010. (Republication of Addendum report no. 758474005, november 1988).&lt;br&gt;Dit rapport bevat een systematisch overzicht en een kritische evaluatie van de belangrijkste gegevens over de prioritaire stofgroep fluoriden ten behoeve van het effectgericht milieubeleid.DGM/SR /Cornet J
    • …
    corecore