456 research outputs found

    Prenatal Stress due to a Natural Disaster Predicts Adiposity in Childhood: The Iowa Flood Study

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    Prenatal stress can affect lifelong physical growth, including increased obesity risk. However, human studies remain limited. Natural disasters provide models of independent stressors unrelated to confounding maternal characteristics. We assessed degree of objective hardship and subjective distress in women pregnant during severe flooding. At ages 2.5 and 4 years we assessed body mass index (BMI), subscapular plus triceps skinfolds (SS + TR, an index of total adiposity), and SS: TR ratio (an index of central adiposity) in their children (n=106). Hierarchical regressions controlled first for several potential confounds. Controlling for these, flood exposure during early gestation predicted greater BMI increase from age 2.5 to 4, as well as total adiposity at 2.5. Greater maternal hardship and distress due to the floods, as well as other nonflood life events during pregnancy, independently predicted greater increase in total adiposity between 2.5 and 4 years. These results support the hypothesis that prenatal stress increases adiposity beginning in childhood and suggest that early gestation is a sensitive period. Results further highlight the additive effects of maternal objective and subjective stress, life events, and depression, emphasizing the importance of continued studies on multiple, detailed measures of maternal mental health and experience in pregnancy and child growth

    A comprehensive analysis of normal variation and disease-causing mutations in the human DSPP gene

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    Within nine dentin dysplasia (type II) and dentinogenesis imperfecta (type II and III) patient/families, seven have one of four net −1 deletions within the ~2kb coding repeat domain of the DSPP gene while the remaining two patients had splice-site mutations. All frameshift mutations are predicted to change the highly soluble DSPP protein into proteins with long hydrophobic amino acid repeats that could interfere with processing of normal DSPP and/or other secreted matrix proteins. We propose that all previously reported missense, nonsense, and splice-site DSPP mutations (all associated with exons 2 and 3) result in dominant phenotypes due to disruption of signal peptide-processing and/or related biochemical events that also result in interference with protein processing. This would bring the currently known dominant forms of the human disease phenotype in agreement with the normal phenotype of the heterozygous null Dspp (−/+) mice. A study of 188 normal human chromosomes revealed a hypervariable DSPP repeat domain with extraordinary rates of change including 20 slip-replication indel events and 37 predominantly C-to-T transition SNPs. The most frequent transition in the primordial 9-bp DNA repeat was a sense-strand CpG site while a CpNpG (CAG) transition was the second most frequent SNP. Bisulfite-sequencing of genomic DNA showed that DSPP repeat can be methylated at both motifs. This suggests that, like plants and some animals, human methylate some CpNpG sequences. Analysis of 37 haplotypes of the highly variable DSPP gene from geographically diverse people suggests it may be a useful autosomal marker in human migration studies

    Exclusion of known gene for enamel development in two Brazilian families with amelogenesis imperfecta

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    Amelogenesis imperfecta (AI) is a genetically heterogeneous group of diseases that result in defective development of tooth enamel. Mutations in several enamel proteins and proteinases have been associated with AI. The object of this study was to evaluate evidence of etiology for the six major candidate gene loci in two Brazilian families with AI. Genomic DNA was obtained from family members and all exons and exon-intron boundaries of the ENAM, AMBN, AMELX, MMP20, KLK4 and Amelotin gene were amplified and sequenced. Each family was also evaluated for linkage to chromosome regions known to contain genes important in enamel development. The present study indicates that the AI in these two families is not caused by any of the known loci for AI or any of the major candidate genes proposed in the literature. These findings indicate extensive genetic heterogeneity for non-syndromic AI

    Comparative genomics of isolates of a pseudomonas aeruginosa epidemic strain associated with chronic lung infections of cystic fibrosis patients

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    Pseudomonas aeruginosa is the main cause of fatal chronic lung infections among individuals suffering from cystic fibrosis (CF). During the past 15 years, particularly aggressive strains transmitted among CF patients have been identified, initially in Europe and more recently in Canada. The aim of this study was to generate high-quality genome sequences for 7 isolates of the Liverpool epidemic strain (LES) from the United Kingdom and Canada representing different virulence characteristics in order to: (1) associate comparative genomics results with virulence factor variability and (2) identify genomic and/or phenotypic divergence between the two geographical locations. We performed phenotypic characterization of pyoverdine, pyocyanin, motility, biofilm formation, and proteolytic activity. We also assessed the degree of virulence using the Dictyostelium discoideum amoeba model. Comparative genomics analysis revealed at least one large deletion (40-50 kb) in 6 out of the 7 isolates compared to the reference genome of LESB58. These deletions correspond to prophages, which are known to increase the competitiveness of LESB58 in chronic lung infection. We also identified 308 non-synonymous polymorphisms, of which 28 were associated with virulence determinants and 52 with regulatory proteins. At the phenotypic level, isolates showed extensive variability in production of pyocyanin, pyoverdine, proteases and biofilm as well as in swimming motility, while being predominantly avirulent in the amoeba model. Isolates from the two continents were phylogenetically and phenotypically undistinguishable. Most regulatory mutations were isolate-specific and 29% of them were predicted to have high functional impact. Therefore, polymorphism in regulatory genes is likely to be an important basis for phenotypic diversity among LES isolates, which in turn might contribute to this strain's adaptability to varying conditions in the CF lung

    <html>Human and Mouse Enamel Phenotypes Resulting from Mutation or Altered Expression of <i>AMEL, ENAM</i>, <i>MMP20</i> and <i>KLK4</i></html>

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    Amelogenesis imperfecta (AI) is caused by AMEL, ENAM, MMP20 and KLK4 gene mutations. Mice lacking expression of the AmelX, Enam and Mmp20 genes have been generated. These mouse models provide tools for understanding enamel formation and AI pathogenesis. This study describes the AI phenotypes and relates them to their mouse model counterparts. Human AI phenotypes were determined in a clinical population of AI families and published cases. Human and murine teeth were evaluated using light and electron microscopy. A total of 463 individuals from 54 families were evaluated and mutations in the AMEL, ENAM and KLK4 genes were identified. The majority of human mutations for genes coding enamel nonproteinase proteins (AMEL and ENAM) resulted in variable hypoplasia ranging from local pitting to a marked, generalized enamel thinning. Specific AMEL mutations were associated with abnormal mineralization and maturation defects. Amel and Enam null murine models displayed marked enamel hypoplasia and a complete loss of prism structure. Human mutations in genes coding for the enamel proteinases (MMP20 and KLK4) cause variable degrees of hypomineralization. The murine Mmp20 null mouse exhibits both hypoplastic and hypomineralized defects. The currently available Amel and Enam mouse models for AI exhibit enamel phenotypes (hypoplastic) that are generally similar to those seen in humans. Mmp20 null mice have a greater degree of hypoplasia than humans with MMP20 mutations. Mice lacking expression of the currently known genes associated with the human AI conditions provide useful models for understanding the pathogenesis of these conditions

    Mismatches in scale between highly mobile marine megafauna and marine protected areas

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    Marine protected areas (MPAs), particularly large MPAs, are increasing in number and size around the globe in part to facilitate the conservation of marine megafauna under the assumption that large-scale MPAs better align with vagile life histories; however, this alignment is not well established. Using a global tracking dataset from 36 species across five taxa, chosen to reflect the span of home range size in highly mobile marine megafauna, we show most MPAs are too small to encompass complete home ranges of most species. Based on size alone, 40% of existing MPAs could encompass the home ranges of the smallest ranged species, while only < 1% of existing MPAs could encompass those of the largest ranged species. Further, where home ranges and MPAs overlapped in real geographic space, MPAs encompassed < 5% of core areas used by all species. Despite most home ranges of mobile marine megafauna being much larger than existing MPAs, we demonstrate how benefits from MPAs are still likely to accrue by targeting seasonal aggregations and critical life history stages and through other management techniques.Fil: Conners, Melinda G.. University of Washington; Estados Unidos. State University of New York. Stony Brook University; Estados UnidosFil: Sisson, Nicholas B.. Old Dominion University; Estados UnidosFil: Agamboue, Pierre D.. Wildlife Conservation Society; GabónFil: Atkinson, Philip W.. British Trust For Ornithology; Reino UnidoFil: Baylis, Alastair M. M.. Macquarie University; Australia. South Atlantic Environmental Research Institute; Reino UnidoFil: Benson, Scott R.. Noaa National Marine Fisheries Service Southwest Regional Office; Estados Unidos. Moss Landing Marine Laboratories; Estados UnidosFil: Block, Barbara A.. University of Stanford; Estados UnidosFil: Bograd, Steven J.. Noaa National Marine Fisheries Service Southwest Regional Office; Estados UnidosFil: Bordino, Pablo. Mote Marine Laboratory; Estados UnidosFil: Bowen, W.D.. Bedford Institute Of Oceanography, Fisheries And Oceans Canada; Canadá. Dalhousie University Halifax; CanadáFil: Brickle, Paul. South Atlantic Environmental Research Institute; Reino Unido. University of Aberdeen; Reino Unido. University Of Aberdeeen; Reino UnidoFil: Bruno, Ignacio Matias. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: González Carman, Victoria. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Champagne, Cory D.. University of Washington; Estados UnidosFil: Crocker, Daniel E.. Sonoma State University; Estados UnidosFil: Costa, Daniel P.. University of California; Estados UnidosFil: Dawson, Tiffany M.. University Of Central Florida; Estados Unidos. Old Dominion University; Estados UnidosFil: Deguchi, Tomohiro. Yamashina Institute For Ornithology; JapónFil: Dewar, Heidi. Noaa National Marine Fisheries Service Southwest Regional Office; Estados UnidosFil: Doherty, Philip D.. University of Exeter; Reino UnidoFil: Eguchi, Tomo. Noaa National Marine Fisheries Service Southwest Regional Office; Estados UnidosFil: Formia, Angela. Wildlife Conservation Society; Gabón. African Aquatic Conservation Fund; Estados UnidosFil: Godley, Brendan J.. University of Exeter; Reino UnidoFil: Graham, Rachel T.. Maralliance; PanamáFil: Gredzens, Christian. Padre Island National Seashore; Estados UnidosFil: Hart, Kristen M.. United States Geological Survey; Estados UnidosFil: Hawkes, Lucy A.. University of Exeter; Reino UnidoFil: Henderson, Suzanne. Scottish Natural Heritage; Reino UnidoFil: Henry, Robert William. Groundswell Coastal Ecology; Estados UnidosFil: Hückstädt, Luis A.. University of Exeter; Reino Unido. University of California; Estados Unido

    Mutations causing medullary cystic kidney disease type 1 (MCKD1) lie in a large VNTR in MUC1 missed by massively parallel sequencing

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    While genetic lesions responsible for some Mendelian disorders can be rapidly discovered through massively parallel sequencing (MPS) of whole genomes or exomes, not all diseases readily yield to such efforts. We describe the illustrative case of the simple Mendelian disorder medullary cystic kidney disease type 1 (MCKD1), mapped more than a decade ago to a 2-Mb region on chromosome 1. Ultimately, only by cloning, capillary sequencing, and de novo assembly, we found that each of six MCKD1 families harbors an equivalent, but apparently independently arising, mutation in sequence dramatically underrepresented in MPS data: the insertion of a single C in one copy (but a different copy in each family) of the repeat unit comprising the extremely long (~1.5-5 kb), GC-rich (>80%), coding VNTR in the mucin 1 gene. The results provide a cautionary tale about the challenges in identifying genes responsible for Mendelian, let alone more complex, disorders through MPS
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