137 research outputs found
Microfocal X-Ray Computed Tomography Post-Processing Operations for Optimizing Reconstruction Volumes of Stented Arteries During 3D Computational Fluid Dynamics Modeling
Restenosis caused by neointimal hyperplasia (NH) remains an important clinical problem after stent implantation. Restenosis varies with stent geometry, and idealized computational fluid dynamics (CFD) models have indicated that geometric properties of the implanted stent may differentially influence NH. However, 3D studies capturing the in vivo flow domain within stented vessels have not been conducted at a resolution sufficient to detect subtle alterations in vascular geometry caused by the stent and the subsequent temporal development of NH. We present the details and limitations of a series of post-processing operations used in conjunction with microfocal X-ray CT imaging and reconstruction to generate geometrically accurate flow domains within the localized region of a stent several weeks after implantation. Microfocal X-ray CT reconstruction volumes were subjected to an automated program to perform arterial thresholding, spatial orientation, and surface smoothing of stented and unstented rabbit iliac arteries several weeks after antegrade implantation. A transfer function was obtained for the current post-processing methodology containing reconstructed 16 mm stents implanted into rabbit iliac arteries for up to 21 days after implantation and resolved at circumferential and axial resolutions of 32 and 50 μm, respectively. The results indicate that the techniques presented are sufficient to resolve distributions of WSS with 80% accuracy in segments containing 16 surface perturbations over a 16 mm stented region. These methods will be used to test the hypothesis that reductions in normalized wall shear stress (WSS) and increases in the spatial disparity of WSS immediately after stent implantation may spatially correlate with the temporal development of NH within the stented region
www.Didartic.com: Activating the Didactic, Self-Reflective Fairytale through Hypermedia As a Model for the Art Education Activist
Abstract www.Didartic.com: Activating the Didactic, Self-Reflective Fairytale through Hypermedia As a Model for the Art Education Activist Timothy W. Broadwater The struggle for meaning, reflection, and self-understanding is an important process of human development. Throughout human history didactic art -art wherein the central purpose is to instruct the viewer -has been developed to aid this human function. Focusing primarily on the didactic art of fairytales, however, one can see that the dominant role of reflection and self-understanding is lost in contemporary translation. The role of the viewer/reader of the fairytale, contemporarily, has been switched from one of inner reflection to that of passive absorption. This thesis project will argue that reflection and self-understanding (on the part of the viewer) can best be restored to the fairytale through the use of hypermedia, as well as the artist adopting an art-activist approach to art production. i
Mutant huntingtin's effects on striatal gene expression in mice recapitulate changes observed in human Huntington's disease brain and do not differ with mutant huntingtin length or wild-type huntingtin dosage
To test the hypotheses that mutant huntingtin protein length and wild-type huntingtin dosage have important effects on disease-related transcriptional dysfunction, we compared the changes in mRNA in seven genetic mouse models of Huntington's disease (HD) and postmortem human HD caudate. Transgenic models expressing short N-terminal fragments of mutant huntingtin (R6/1 and R6/2 mice) exhibited the most rapid effects on gene expression, consistent with previous studies. Although changes in the brains of knock-in and full-length transgenic models of HD took longer to appear, 15- and 22-month CHL2Q150/Q150, 18-month HdhQ92/Q92 and 2-year-old YAC128 animals also exhibited significant HD-like mRNA signatures. Whereas it was expected that the expression of full-length huntingtin transprotein might result in unique gene expression changes compared with those caused by the expression of an N-terminal huntingtin fragment, no discernable differences between full-length and fragment models were detected. In addition, very high correlations between the signatures of mice expressing normal levels of wild-type huntingtin and mice in which the wild-type protein is absent suggest a limited effect of the wild-type protein to change basal gene expression or to influence the qualitative disease-related effect of mutant huntingtin. The combined analysis of mouse and human HD transcriptomes provides important temporal and mechanistic insights into the process by which mutant huntingtin kills striatal neurons. In addition, the discovery that several available lines of HD mice faithfully recapitulate the gene expression signature of the human disorder provides a novel aspect of validation with respect to their use in preclinical therapeutic trial
Novel mesothelin antibodies enable crystallography of the intact mesothelin ectodomain and engineering of potent, T cell-engaging bispecific therapeutics
Mesothelin is a glypiated, cell-surface glycoprotein expressed at low levels on normal mesothelium but overexpressed by many cancers. Implicated in cell adhesion and multiple signaling pathways, mesothelin’s precise biological function and overall structure remain undefined. Antibodies targeting mesothelin have been engineered into immunotoxins, antibody-drug conjugates, CAR-T cells, or bispecific T cell engagers as candidate therapeutics but most face challenges, including binding epitopes that are not optimal for selected modalities. Here we describe the isolation and characterization of a novel anti-mesothelin antibody, 1A12, including crystallographic mapping of the 1A12 epitope in relation to other antibodies (amatuximab, anetumab). 1A12 possesses uniquely favorable properties, including a membrane-proximal epitope, and enabled structure determination of the complete mesothelin ectodomain. We incorporated 1A12 into two different bispecific T cell engaging architectures with various anti-CD3 co-targeting elements as candidate therapeutics, demonstrating in vitro functionality and potency
Genome-wide association scan identifies new variants associated with a cognitive predictor of dyslexia
Developmental dyslexia (DD) is one of the most prevalent learning disorders, with high impact on school and psychosocial development and high comorbidity with conditions like attention-deficit hyperactivity disorder (ADHD), depression, and anxiety. DD is characterized by deficits in different cognitive skills, including word reading, spelling, rapid naming, and phonology. To investigate the genetic basis of DD, we conducted a genome-wide association study (GWAS) of these skills within one of the largest studies available, including nine cohorts of reading-impaired and typically developing children of European ancestry (N = 2562-3468). We observed a genome-wide significant effect (p <1 x 10(-8)) on rapid automatized naming of letters (RANlet) for variants on 18q12.2, within MIR924HG (micro-RNA 924 host gene; rs17663182 p = 4.73 x 10(-9)), and a suggestive association on 8q12.3 within NKAIN3 (encoding a cation transporter; rs16928927, p = 2.25 x 10(-8)). rs17663182 (18q12.2) also showed genome-wide significant multivariate associations with RAN measures (p = 1.15 x 10(-8)) and with all the cognitive traits tested (p = 3.07 x 10(-8)), suggesting (relational) pleiotropic effects of this variant. A polygenic risk score (PRS) analysis revealed significant genetic overlaps of some of the DD-related traits with educational attainment (EDUyears) and ADHD. Reading and spelling abilities were positively associated with EDUyears (p similar to [10(-5)-10(-7)]) and negatively associated with ADHD PRS (p similar to [10(-8)-10(-17)]). This corroborates a long-standing hypothesis on the partly shared genetic etiology of DD and ADHD, at the genome-wide level. Our findings suggest new candidate DD susceptibility genes and provide new insights into the genetics of dyslexia and its comorbities.Peer reviewe
Genome-wide association scan identifies new variants associated with a cognitive predictor of dyslexia
Developmental dyslexia (DD) is one of the most prevalent learning disorders, with high impact on school and psychosocial development and high comorbidity with conditions like attention-deficit hyperactivity disorder (ADHD), depression, and anxiety. DD is characterized by deficits in different cognitive skills, including word reading, spelling, rapid naming, and phonology. To investigate the genetic basis of DD, we conducted a genome-wide association study (GWAS) of these skills within one of the largest studies available, including nine cohorts of reading-impaired and typically developing children of European ancestry (N = 2562-3468). We observed a genome-wide significant effect (p < 1 x 10(-8)) on rapid automatized naming of letters (RANlet) for variants on 18q12.2, within MIR924HG (micro-RNA 924 host gene;rs17663182 p = 4.73 x 10(-9)), and a suggestive association on 8q12.3 within NKAIN3 (encoding a cation transporter;rs16928927, p = 2.25 x 10(-8)). rs17663182 (18q12.2) also showed genome-wide significant multivariate associations with RAN measures (p = 1.15 x 10(-8)) and with all the cognitive traits tested (p = 3.07 x 10(-8)), suggesting (relational) pleiotropic effects of this variant. A polygenic risk score (PRS) analysis revealed significant genetic overlaps of some of the DD-related traits with educational attainment (EDUyears) and ADHD. Reading and spelling abilities were positively associated with EDUyears (p similar to [10(-5)-10(-7)]) and negatively associated with ADHD PRS (p similar to [10(-8)-10(-17)]). This corroborates a long-standing hypothesis on the partly shared genetic etiology of DD and ADHD, at the genome-wide level. Our findings suggest new candidate DD susceptibility genes and provide new insights into the genetics of dyslexia and its comorbities
Genome-wide association study reveals new insights into the heritability and genetic correlates of developmental dyslexia
Developmental dyslexia (DD) is a learning disorder affecting the ability to read, with a heritability of 40-60%. A notable part of this heritability remains unexplained, and large genetic studies are warranted to identify new susceptibility genes and clarify the genetic bases of dyslexia. We carried out a genome-wide association study (GWAS) on 2274 dyslexia cases and 6272 controls, testing associations at the single variant, gene, and pathway level, and estimating heritability using single-nucleotide polymorphism (SNP) data. We also calculated polygenic scores (PGSs) based on large-scale GWAS data for different neuropsychiatric disorders and cortical brain measures, educational attainment, and fluid intelligence, testing them for association with dyslexia status in our sample. We observed statistically significant (p <2.8 x 10(-6)) enrichment of associations at the gene level, forLOC388780(20p13; uncharacterized gene), and forVEPH1(3q25), a gene implicated in brain development. We estimated an SNP-based heritability of 20-25% for DD, and observed significant associations of dyslexia risk with PGSs for attention deficit hyperactivity disorder (atp(T) = 0.05 in the training GWAS: OR = 1.23[1.16; 1.30] per standard deviation increase;p = 8 x 10(-13)), bipolar disorder (1.53[1.44; 1.63];p = 1 x 10(-43)), schizophrenia (1.36[1.28; 1.45];p = 4 x 10(-22)), psychiatric cross-disorder susceptibility (1.23[1.16; 1.30];p = 3 x 10(-12)), cortical thickness of the transverse temporal gyrus (0.90[0.86; 0.96];p = 5 x 10(-4)), educational attainment (0.86[0.82; 0.91];p = 2 x 10(-7)), and intelligence (0.72[0.68; 0.76];p = 9 x 10(-29)). This study suggests an important contribution of common genetic variants to dyslexia risk, and novel genomic overlaps with psychiatric conditions like bipolar disorder, schizophrenia, and cross-disorder susceptibility. Moreover, it revealed the presence of shared genetic foundations with a neural correlate previously implicated in dyslexia by neuroimaging evidence.Peer reviewe
Genome-wide analyses of individual differences in quantitatively assessed reading- and language-related skills in up to 34,000 people
The use of spoken and written language is a fundamental human capacity. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30 to 80% depending on the trait. The genetic architecture is complex, heterogeneous, and multifactorial, but investigations of contributions of single-nucleotide polymorphisms (SNPs) were thus far underpowered. We present a multicohort genome-wide association study (GWAS) of five traits assessed individually using psychometric measures (word reading, nonword reading, spelling, phoneme awareness, and nonword repetition) in samples of 13,633 to 33,959 participants aged 5 to 26 y. We identified genome-wide significant association with word reading (rs11208009, P = 1.098 x 10(-8)) at a locus that has not been associated with intelligence or educational attainment. All five reading-/language-related traits showed robust SNP heritability, accounting for 13 to 26% of trait variability. Genomic structural equation modeling revealed a shared genetic factor explaining most of the variation in word/nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence, and educational attainment. A multivariate GWAS of word/nonword reading, spelling, and phoneme awareness maximized power for follow-up investigation. Genetic correlation analysis with neuroimaging traits identified an association with the surface area of the banks of the left superior temporal sulcus, a brain region linked to the processing of spoken and written language. Heritability was enriched for genomic elements regulating gene expression in the fetal brain and in chromosomal regions that are depleted of Neanderthal variants. Together, these results provide avenues for deciphering the biological underpinnings of uniquely human traits.Peer reviewe
Hypothesis-driven genome-wide association studies provide novel insights into genetics of reading disabilities
Peer reviewe
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