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1.
Cell ; 172(5): 897-909.e21, 2018 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-29474918

RESUMEN

X-linked Dystonia-Parkinsonism (XDP) is a Mendelian neurodegenerative disease that is endemic to the Philippines and is associated with a founder haplotype. We integrated multiple genome and transcriptome assembly technologies to narrow the causal mutation to the TAF1 locus, which included a SINE-VNTR-Alu (SVA) retrotransposition into intron 32 of the gene. Transcriptome analyses identified decreased expression of the canonical cTAF1 transcript among XDP probands, and de novo assembly across multiple pluripotent stem-cell-derived neuronal lineages discovered aberrant TAF1 transcription that involved alternative splicing and intron retention (IR) in proximity to the SVA that was anti-correlated with overall TAF1 expression. CRISPR/Cas9 excision of the SVA rescued this XDP-specific transcriptional signature and normalized TAF1 expression in probands. These data suggest an SVA-mediated aberrant transcriptional mechanism associated with XDP and may provide a roadmap for layered technologies and integrated assembly-based analyses for other unsolved Mendelian disorders.


Asunto(s)
Trastornos Distónicos/genética , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Genoma Humano , Transcriptoma/genética , Empalme Alternativo/genética , Elementos Alu/genética , Secuencia de Bases , Sistemas CRISPR-Cas/genética , Estudios de Cohortes , Familia , Femenino , Sitios Genéticos , Haplotipos/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Histona Acetiltransferasas/genética , Histona Acetiltransferasas/metabolismo , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Intrones/genética , Masculino , Repeticiones de Minisatélite/genética , Modelos Genéticos , Degeneración Nerviosa/genética , Degeneración Nerviosa/patología , Células-Madre Neurales/metabolismo , Neuronas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Elementos de Nucleótido Esparcido Corto , Factores Asociados con la Proteína de Unión a TATA/genética , Factores Asociados con la Proteína de Unión a TATA/metabolismo , Factor de Transcripción TFIID/genética , Factor de Transcripción TFIID/metabolismo
2.
Genome Res ; 27(5): 757-767, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28381613

RESUMEN

Determining the genome sequence of an organism is challenging, yet fundamental to understanding its biology. Over the past decade, thousands of human genomes have been sequenced, contributing deeply to biomedical research. In the vast majority of cases, these have been analyzed by aligning sequence reads to a single reference genome, biasing the resulting analyses, and in general, failing to capture sequences novel to a given genome. Some de novo assemblies have been constructed free of reference bias, but nearly all were constructed by merging homologous loci into single "consensus" sequences, generally absent from nature. These assemblies do not correctly represent the diploid biology of an individual. In exactly two cases, true diploid de novo assemblies have been made, at great expense. One was generated using Sanger sequencing, and one using thousands of clone pools. Here, we demonstrate a straightforward and low-cost method for creating true diploid de novo assemblies. We make a single library from ∼1 ng of high molecular weight DNA, using the 10x Genomics microfluidic platform to partition the genome. We applied this technique to seven human samples, generating low-cost HiSeq X data, then assembled these using a new "pushbutton" algorithm, Supernova. Each computation took 2 d on a single server. Each yielded contigs longer than 100 kb, phase blocks longer than 2.5 Mb, and scaffolds longer than 15 Mb. Our method provides a scalable capability for determining the actual diploid genome sequence in a sample, opening the door to new approaches in genomic biology and medicine.


Asunto(s)
Mapeo Contig/métodos , Diploidia , Análisis de Secuencia de ADN/métodos , Genoma Humano , Biblioteca Genómica , Humanos , Microfluídica/métodos , Programas Informáticos
3.
BMC Genomics ; 17: 187, 2016 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-26944054

RESUMEN

BACKGROUND: De novo reference assemblies that are affordable, practical to produce, and of sufficient quality for most downstream applications, remain an unattained goal for many taxa. Insects, which may yield too little DNA from individual specimens for long-read sequencing library construction and often have highly heterozygous genomes, can be particularly hard to assemble using inexpensive short-read sequencing data. The large number of insect species with medical or economic importance makes this a critical problem to address. RESULTS: Using the assembler DISCOVAR de novo, we assembled the genome of the African malaria mosquito Anopheles arabiensis using 250 bp reads from a single library. The resulting assembly had a contig N50 of 22,433 bp, and recovered the gene set nearly as well as the ALLPATHS-LG AaraD1 An. arabiensis assembly produced with reads from three sequencing libraries and much greater resources. DISCOVAR de novo appeared to perform better than ALLPATHS-LG in regions of low complexity. CONCLUSIONS: DISCOVAR de novo performed well assembling the genome of an insect of medical importance, using simpler sequencing input than previous anopheline assemblies. We have shown that this program is a viable tool for cost-effective assembly of a modestly-sized insect genome.


Asunto(s)
Anopheles/genética , Genoma de los Insectos , Análisis de Secuencia de ADN/métodos , Alelos , Animales , Femenino , Biblioteca de Genes , Modelos Genéticos , Polimorfismo de Nucleótido Simple
5.
J Pediatr ; 164(5): 1121-1127.e1, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24367983

RESUMEN

OBJECTIVE: To investigate the relationship between tissue-specific alterations in brain volume and neurobehavioral status in newborns with complex congenital heart defects preoperatively. STUDY DESIGN: Three-dimensional volumetric magnetic resonance imaging was used to calculate tissue-specific brain volumes and a standardized neurobehavioral assessment was performed to assess neurobehavioral status in 35 full-term newborns admitted to the hospital before cardiopulmonary bypass surgery. Multiple linear regression models were performed to evaluate relationships between neurobehavioral status and brain volumes. RESULTS: Reduced subcortical gray matter (SCGM) volume and increased cerebrospinal fluid (CSF) volume were associated with poor behavioral state regulation (SCGM, P = .04; CSF, P = .007) and poor visual orienting (CSF, P = .003). In cyanotic newborns, reduced SCGM was associated with higher overall abnormal scores on the assessment (P = .001) and poor behavioral state regulation (P = .04), and increased CSF volume was associated with poor behavioral state regulation (P = .02), and poor visual orienting (P = .02). Conversely, acyanotic newborns showed associations between reduced cerebellar volume and poor behavioral state regulation (P = .03). CONCLUSION: Abnormal neurobehavior is associated with impaired volumetric brain growth before open heart surgery in infants with complex congenital heart defects. This study highlights a need for routine preoperative screening and early intervention to improve neurodevelopmental outcomes.


Asunto(s)
Lesiones Encefálicas/etiología , Encéfalo/patología , Cardiopatías Congénitas/complicaciones , Conducta del Lactante , Lesiones Encefálicas/diagnóstico , Puente Cardiopulmonar , Femenino , Cardiopatías Congénitas/patología , Cardiopatías Congénitas/psicología , Cardiopatías Congénitas/cirugía , Humanos , Interpretación de Imagen Asistida por Computador , Imagenología Tridimensional , Recién Nacido , Modelos Lineales , Imagen por Resonancia Magnética , Masculino , Examen Neurológico , Pruebas Neuropsicológicas , Variaciones Dependientes del Observador , Tamaño de los Órganos , Periodo Preoperatorio , Estudios Prospectivos , Método Simple Ciego
6.
BMC Pediatr ; 13: 25, 2013 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-23421857

RESUMEN

BACKGROUND: The experience in the newborn intensive care nursery results in premature infants' neurobehavioral and neurophysiological dysfunction and poorer brain structure. Preterms with severe intrauterine growth restriction are doubly jeopardized given their compromised brains. The Newborn Individualized Developmental Care and Assessment Program improved outcome at early school-age for preterms with appropriate intrauterine growth. It also showed effectiveness to nine months for preterms with intrauterine growth restriction. The current study tested effectiveness into school-age for preterms with intrauterine growth restriction regarding executive function (EF), electrophysiology (EEG) and neurostructure (MRI). METHODS: Twenty-three 9-year-old former growth-restricted preterms, randomized at birth to standard care (14 controls) or to the Newborn Individualized Developmental Care and Assessment Program (9 experimentals) were assessed with standardized measures of cognition, achievement, executive function, electroencephalography, and magnetic resonance imaging. The participating children were comparable to those lost to follow-up, and the controls to the experimentals, in terms of newborn background health and demographics. All outcome measures were corrected for mother's intelligence. Analysis techniques included two-group analysis of variance and stepwise discriminate analysis for the outcome measures, Wilks' lambda and jackknifed classification to ascertain two-group classification success per and across domains; canonical correlation analysis to explore relationships among neuropsychological, electrophysiological and neurostructural domains at school-age, and from the newborn period to school-age. RESULTS: Controls and experimentals were comparable in age at testing, anthropometric and health parameters, and in cognitive and achievement scores. Experimentals scored better in executive function, spectral coherence, and cerebellar volumes. Furthermore, executive function, spectral coherence and brain structural measures discriminated controls from experimentals. Executive function correlated with coherence and brain structure measures, and with newborn-period neurobehavioral assessment. CONCLUSION: The intervention in the intensive care nursery improved executive function as well as spectral coherence between occipital and frontal as well as parietal regions. The experimentals' cerebella were significantly larger than the controls'. These results, while preliminary, point to the possibility of long-term brain improvement even of intrauterine growth compromised preterms if individualized intervention begins with admission to the NICU and extends throughout transition home. Larger sample replications are required in order to confirm these results. CLINICAL TRIAL REGISTRATION: The study is registered as a clinical trial. The trial registration number is NCT00914108.


Asunto(s)
Encéfalo/fisiología , Desarrollo Infantil/fisiología , Función Ejecutiva , Retardo del Crecimiento Fetal/terapia , Recien Nacido Prematuro , Cuidado Intensivo Neonatal/métodos , Logro , Análisis de Varianza , Encéfalo/crecimiento & desarrollo , Niño , Conducta Infantil , Cognición , Análisis Discriminante , Electroencefalografía , Femenino , Estudios de Seguimiento , Humanos , Conducta del Lactante , Recién Nacido , Imagen por Resonancia Magnética , Masculino , Pruebas Psicológicas , Resultado del Tratamiento
7.
Nat Commun ; 12(1): 463, 2021 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-33469025

RESUMEN

Splicing varies across brain regions, but the single-cell resolution of regional variation is unclear. We present a single-cell investigation of differential isoform expression (DIE) between brain regions using single-cell long-read sequencing in mouse hippocampus and prefrontal cortex in 45 cell types at postnatal day 7 ( www.isoformAtlas.com ). Isoform tests for DIE show better performance than exon tests. We detect hundreds of DIE events traceable to cell types, often corresponding to functionally distinct protein isoforms. Mostly, one cell type is responsible for brain-region specific DIE. However, for fewer genes, multiple cell types influence DIE. Thus, regional identity can, although rarely, override cell-type specificity. Cell types indigenous to one anatomic structure display distinctive DIE, e.g. the choroid plexus epithelium manifests distinct transcription-start-site usage. Spatial transcriptomics and long-read sequencing yield a spatially resolved splicing map. Our methods quantify isoform expression with cell-type and spatial resolution and it contributes to further our understanding of how the brain integrates molecular and cellular complexity.


Asunto(s)
Empalme Alternativo/fisiología , Regulación del Desarrollo de la Expresión Génica/fisiología , Hipocampo/metabolismo , Corteza Prefrontal/metabolismo , Isoformas de Proteínas/metabolismo , Animales , Animales Recién Nacidos , Biología Computacional , Femenino , Hipocampo/citología , Hipocampo/crecimiento & desarrollo , Ratones , Modelos Animales , Corteza Prefrontal/citología , Corteza Prefrontal/crecimiento & desarrollo , Isoformas de Proteínas/análisis , Isoformas de Proteínas/genética , Análisis de la Célula Individual/métodos , Análisis Espacial
8.
Nat Genet ; 53(9): 1334-1347, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34493872

RESUMEN

Breast cancers are complex cellular ecosystems where heterotypic interactions play central roles in disease progression and response to therapy. However, our knowledge of their cellular composition and organization is limited. Here we present a single-cell and spatially resolved transcriptomics analysis of human breast cancers. We developed a single-cell method of intrinsic subtype classification (SCSubtype) to reveal recurrent neoplastic cell heterogeneity. Immunophenotyping using cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) provides high-resolution immune profiles, including new PD-L1/PD-L2+ macrophage populations associated with clinical outcome. Mesenchymal cells displayed diverse functions and cell-surface protein expression through differentiation within three major lineages. Stromal-immune niches were spatially organized in tumors, offering insights into antitumor immune regulation. Using single-cell signatures, we deconvoluted large breast cancer cohorts to stratify them into nine clusters, termed 'ecotypes', with unique cellular compositions and clinical outcomes. This study provides a comprehensive transcriptional atlas of the cellular architecture of breast cancer.


Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Análisis de la Célula Individual , Transcriptoma/genética , Linfocitos B/inmunología , Antígeno B7-H1/genética , Biomarcadores de Tumor/genética , Neoplasias de la Mama/inmunología , Linfocitos T CD8-positivos/inmunología , Células Endoteliales/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Macrófagos/citología , Macrófagos/inmunología , Proteínas de la Membrana/genética , Células Mieloides/inmunología , Células Mieloides/metabolismo , Análisis de Secuencia de ARN , Microambiente Tumoral , Proteínas Supresoras de Tumor/genética
9.
Neuroimage ; 47(2): 564-72, 2009 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-19409502

RESUMEN

Quantitative brain tissue segmentation from newborn MRI offers the possibility of improved clinical decision making and diagnosis, new insight into the mechanisms of disease, and new methods for the evaluation of treatment protocols for preterm newborns. Such segmentation is challenging, however, due to the imaging characteristics of the developing brain. Existing techniques for newborn segmentation either achieve automation by ignoring critical distinctions between different tissue types or require extensive expert interaction. Because manual interaction is time consuming and introduces both bias and variability, we have developed a novel automatic segmentation algorithm for brain MRI of newborn infants. The key algorithmic contribution of this work is a new approach for automatically learning patient-specific class-conditional probability density functions. The algorithm achieves performance comparable to expert segmentations while automatically identifying cortical gray matter, subcortical gray matter, cerebrospinal fluid, myelinated white matter and unmyelinated white matter. We compared the performance of our algorithm with a previously published semi-automated algorithm and with expert-drawn images. Our algorithm achieved an accuracy comparable with methods that require undesirable manual interaction.


Asunto(s)
Algoritmos , Inteligencia Artificial , Encéfalo/anatomía & histología , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Imagen por Resonancia Magnética/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Femenino , Humanos , Aumento de la Imagen/métodos , Recién Nacido , Masculino , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
10.
Hortic Res ; 5: 4, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29423234

RESUMEN

Linked-Read sequencing technology has recently been employed successfully for de novo assembly of human genomes, however, the utility of this technology for complex plant genomes is unproven. We evaluated the technology for this purpose by sequencing the 3.5-gigabase (Gb) diploid pepper (Capsicum annuum) genome with a single Linked-Read library. Plant genomes, including pepper, are characterized by long, highly similar repetitive sequences. Accordingly, significant effort is used to ensure that the sequenced plant is highly homozygous and the resulting assembly is a haploid consensus. With a phased assembly approach, we targeted a heterozygous F1 derived from a wide cross to assess the ability to derive both haplotypes and characterize a pungency gene with a large insertion/deletion. The Supernova software generated a highly ordered, more contiguous sequence assembly than all currently available C. annuum reference genomes. Over 83% of the final assembly was anchored and oriented using four publicly available de novo linkage maps. A comparison of the annotation of conserved eukaryotic genes indicated the completeness of assembly. The validity of the phased assembly is further demonstrated with the complete recovery of both 2.5-Kb insertion/deletion haplotypes of the PUN1 locus in the F1 sample that represents pungent and nonpungent peppers, as well as nearly full recovery of the BUSCO2 gene set within each of the two haplotypes. The most contiguous pepper genome assembly to date has been generated which demonstrates that Linked-Read library technology provides a tool to de novo assemble complex highly repetitive heterozygous plant genomes. This technology can provide an opportunity to cost-effectively develop high-quality genome assemblies for other complex plants and compare structural and gene differences through accurate haplotype reconstruction.

11.
Med Image Anal ; 9(2): 145-62, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15721230

RESUMEN

During neurosurgical procedures the objective of the neurosurgeon is to achieve the resection of as much diseased tissue as possible while achieving the preservation of healthy brain tissue. The restricted capacity of the conventional operating room to enable the surgeon to visualize critical healthy brain structures and tumor margin has lead, over the past decade, to the development of sophisticated intraoperative imaging techniques to enhance visualization. However, both rigid motion due to patient placement and nonrigid deformations occurring as a consequence of the surgical intervention disrupt the correspondence between preoperative data used to plan surgery and the intraoperative configuration of the patient's brain. Similar challenges are faced in other interventional therapies, such as in cryoablation of the liver, or biopsy of the prostate. We have developed algorithms to model the motion of key anatomical structures and system implementations that enable us to estimate the deformation of the critical anatomy from sequences of volumetric images and to prepare updated fused visualizations of preoperative and intraoperative images at a rate compatible with surgical decision making. This paper reviews the experience at Brigham and Women's Hospital through the process of developing and applying novel algorithms for capturing intraoperative deformations in support of image guided therapy.


Asunto(s)
Algoritmos , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/cirugía , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Neurocirugia/métodos , Técnica de Sustracción , Cirugía Asistida por Computador/métodos , Elasticidad , Humanos , Cuidados Intraoperatorios/métodos , Movimiento , Proyectos de Investigación , Utah
12.
Nat Genet ; 46(12): 1350-5, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25326702

RESUMEN

Complete knowledge of the genetic variation in individual human genomes is a crucial foundation for understanding the etiology of disease. Genetic variation is typically characterized by sequencing individual genomes and comparing reads to a reference. Existing methods do an excellent job of detecting variants in approximately 90% of the human genome; however, calling variants in the remaining 10% of the genome (largely low-complexity sequence and segmental duplications) is challenging. To improve variant calling, we developed a new algorithm, DISCOVAR, and examined its performance on improved, low-cost sequence data. Using a newly created reference set of variants from the finished sequence of 103 randomly chosen fosmids, we find that some standard variant call sets miss up to 25% of variants. We show that the combination of new methods and improved data increases sensitivity by several fold, with the greatest impact in challenging regions of the human genome.


Asunto(s)
Variación Genética , Genoma Humano , Algoritmos , Secuencia de Bases , Mapeo Cromosómico , Frecuencia de los Genes , Genoma , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Datos de Secuencia Molecular , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa , Polimorfismo de Nucleótido Simple , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Programas Informáticos
13.
Pediatr Neurol ; 48(2): 105-10, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23337002

RESUMEN

The cerebellum plays an important role in motor learning and cognition, and structural cerebellar abnormalities have been associated with cognitive impairment. In tuberous sclerosis complex, neurologic outcome is highly variable, and no consistent imaging or pathologic determinant of cognition has been firmly established. The cerebellum calls for specific attention because mouse models of tuberous sclerosis complex have demonstrated a loss of cerebellar Purkinje cells, and cases of human histologic data have demonstrated a similar loss in patients. We hypothesized that there might be a common cerebellar finding in tuberous sclerosis complex that could be measured as morphometric changes with magnetic resonance imaging. Using a robust, automated image analysis procedure, we studied 36 patients with tuberous sclerosis complex and age-matched control subjects and observed significant volume loss among patients in the cerebellar cortices and vermis. Furthermore, this effect was strongest in a subgroup of 19 patients with a known, pathogenic mutation of the tuberous sclerosis 2 gene and impacted all cerebellar structures. We conclude that patients with tuberous sclerosis complex exhibit volume loss in the cerebellum, and this loss is larger and more widespread in patients with a tuberous sclerosis 2 mutation.


Asunto(s)
Cerebelo/patología , Esclerosis Tuberosa/patología , Adolescente , Adulto , Mapeo Encefálico , Niño , Preescolar , Femenino , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Tamaño de los Órganos
14.
J Clin Neonatol ; 1(4): 184-194, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23951557

RESUMEN

BACKGROUND: By school age, even low risk moderately preterm-born children show more neuro-cognitive deficits, underachievement, behavioral problems, and poor social adaptation than full-term peers. AIM: To evaluate the outcomes at school-age for moderately preterm-born children (29-33 weeks gestational age), appropriate in growth for gestational age (AGA) and medically at low-risk, randomized to Newborn Individualized Developmental Care and Assessment Program (NIDCAP) or standard care in the Newborn Intensive Care Unit. At school-age, the experimental (E) group will show better neuropsychological and neuro-electrophysiological function, as well as improved brain structure than the control (C) group. MATERIALS AND METHODS: The original sample consisted of 30 moderately preterm-born infants (29 to 33 weeks), 23 (8C and 15E) of them were evaluated at 8 years of age, corrected-for-prematurity with neuropsychological, EEG spectral coherence, and diffusion tensor magnetic resonance imaging (DT MRI) measures. RESULTS: E-performed significantly better than C-group children on the Kaufman Assessment Battery for Children-Second Edition (KABC-II) and trended towards better scores on the Rey-Osterrieth Complex Figure Test. They also showed more mature frontal and parietal brain connectivities, and more mature fiber tracts involving the internal capsule and the cingulum. Neurobehavioral results in the newborn period successfully predicted neuropsychological functioning at 8 years corrected age. CONCLUSION: Moderately preterm infants cared for with the NIDCAP intervention showed improved neuropsychological and neuro-electrophysiological function as well as improved brain structure at school-age.

15.
Artículo en Inglés | MEDLINE | ID: mdl-22003715

RESUMEN

PURPOSE: To develop an MRI segmentation method for brain tissues, regions, and substructures that yields improved classification accuracy. Current brain segmentation strategies include two complementary strategies. Multi-spectral classification techniques generate excellent segmentations for tissues with clear intensity contrast, but fail to identify structures defined largely by location, such as lobar parcellations and certain subcortical structures. Conversely, multi-template label fusion methods are excellent for structures defined largely by location, but perform poorly when segmenting structures that cannot be accurately identified through a consensus of registered templates. METHODS: We propose here a novel multi-classifier fusion algorithm with the advantages of both types of segmentation strategy. We illustrate and validate this algorithm using a group of 14 expertly hand-labeled images. RESULTS: Our method generated segmentations of cortical and subcortical structures that were more similar to hand-drawn segmentations than majority vote label fusion or a recently published intensity/label fusion method. CONCLUSIONS: We have presented a novel, general segmentation algorithm with the advantages of both statistical classifiers and label fusion techniques.


Asunto(s)
Mapeo Encefálico/métodos , Encéfalo/patología , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Algoritmos , Bases de Datos Factuales , Humanos , Aprendizaje , Modelos Estadísticos , Reconocimiento de Normas Patrones Automatizadas/métodos , Reproducibilidad de los Resultados , Programas Informáticos
16.
Pediatr Neurol ; 42(2): 101-6, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20117745

RESUMEN

Normal-appearing white matter has been shown via diffusion tensor imaging to be affected in tuberous sclerosis complex. Under the hypothesis that some systems might be differentially affected, including the visual pathways and systems of social cognition, diffusion properties of various regions of white matter were compared. For 10 patients and 6 age-matched control subjects, 3 T magnetic resonance imaging was assessed using diffusion tensor imaging obtained in 35 directions. Three-dimensional volumes corresponding to the geniculocalcarine tracts were extracted via tractography, and two-dimensional regions of interest were used to sample other regions. Regression analysis indicated lower fractional anisotropy in the splenium of corpus callosum and geniculocalcarine tracts in tuberous sclerosis complex group, as well as lower axial diffusivity in the internal capsule, superior temporal gyrus, and geniculocalcarine tracts. Mean and radial diffusivity of the splenium of corpus callosum were higher in the tuberous sclerosis complex group. The differences in diffusion properties of white matter between tuberous sclerosis complex patients and control subjects suggest disorganized and structurally compromised axons with poor myelination. The visual and social cognition systems appear to be differentially involved, which might in part explain the behavioral and cognitive characteristics of the tuberous sclerosis complex population.


Asunto(s)
Imagen de Difusión Tensora , Fibras Nerviosas Mielínicas/patología , Esclerosis Tuberosa/patología , Adolescente , Adulto , Niño , Preescolar , Imagen de Difusión Tensora/métodos , Humanos , Lactante , Adulto Joven
17.
Med Image Comput Comput Assist Interv ; 9(Pt 1): 199-206, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17354891

RESUMEN

The segmentation of newborn brain MRI is important for assessing and directing treatment options for premature infants at risk for developmental disorders, abnormalities, or even death. Segmentation of infant brain MRI is particularly challenging when compared with the segmentation of images acquired from older children and adults. We sought to develop a fully automated segmentation strategy and present here a Bayesian approach utilizing an atlas of priors derived from previous segmentations and a new scheme for automatically selecting and iteratively refining classifier training data using the STAPLE algorithm. Results have been validated by comparison to hand-drawn segmentations.


Asunto(s)
Inteligencia Artificial , Encéfalo/citología , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Neuronas/citología , Reconocimiento de Normas Patrones Automatizadas/métodos , Algoritmos , Humanos , Recién Nacido , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
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