Accuracy, repeatability, and interplatform reproducibility of T1 quantification methods used for DCEâ MRI: Results from a multicenter phantom study

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142505/1/mrm26903_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142505/2/mrm26903.pd

Conduct disorder in girls: neighborhoods, family characteristics, and parenting behaviors

<p>Abstract</p> <p>Background</p> <p>Little is known about the social context of girls with conduct disorder (CD), a question of increasing importance to clinicians and researchers. The purpose of this study was to examine the associations between three social context domains (neighborhood, family characteristics, and parenting behaviors) and CD in adolescent girls, additionally testing for race moderation effects. We predicted that disadvantaged neighborhoods, family characteristics such as parental marital status, and parenting behaviors such as negative discipline would characterize girls with CD. We also hypothesized that parenting behaviors would mediate the associations between neighborhood and family characteristics and CD.</p> <p>Methods</p> <p>We recruited 93 15–17 year-old girls from the community and used a structured psychiatric interview to assign participants to a CD group (n = 52) or a demographically matched group with no psychiatric disorder (n = 41). Each girl and parent also filled out questionnaires about neighborhood, family characteristics, and parenting behaviors.</p> <p>Results</p> <p>Neighborhood quality was not associated with CD in girls. Some family characteristics (parental antisociality) and parenting behaviors (levels of family activities and negative discipline) were characteristic of girls with CD, but notll. There was no moderation by race. Our hypothesis that the association between family characteristics and CD would be mediated by parenting behaviors was not supported.</p> <p>Conclusion</p> <p>This study expanded upon previous research by investigating multiple social context domains in girls with CD and by selecting a comparison group who were not different in age, social class, or race. When these factors are thus controlled, CD in adolescent girls is not significantly associated with neighborhood, but is associated with some family characteristics and some types of parental behaviors. However, the mechanisms underlying these relationships need to be further investigated. We discuss possible explanations for our findings and suggest directions for future research.</p

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Effects of Sulfur Dioxide on abdA Gene Expression and Larval Development in Drosophila melanogaster

In this experiment, we tested the effects sulfur dioxide exposure had on abd-A gene expression and larval development in Drosophila melanogaster. Previous studies showed that sulfur dioxide exposure inhibits development of gonads in adult flies and increases development time. We hypothesized that expression of abd-A would decrease in developing Drosophila exposed to sulfur dioxide. The abd-A gene is in the Hox gene family, which functions in the development of body segmentation. The abd-A gene is specific to the abdominal region of the fly, and is also important to the development of gonads and fat bodies. To test our hypothesis, we randomly selected three sets of mating pairs and allowed them to lay eggs in larval culture dishes. The experimental group of larvae was subjected to sulfur dioxide continuously for seven days, while the control group was not exposed to sulfur dioxide, but kept under the exact same conditions. After the exposure, fly larvae were extracted from their culture dishes, sorted by developmental stage, and counted. RNA was then extracted from the larvae after counting. Reverse-Transcription Polymerase Chain Reaction (RT-PCR) was performed to determine abd-A expression in experimental and control groups. Due to sulfur dioxide having detrimental effects on gonad and larval development, it was predicted that, in the presence of sulfur dioxide, abd-A gene expression would decrease, and developmental time course of larval development would be delayed

Self-Face Identification Is Increased with Left Hand Responses

Evidence suggests that autobiographical memory, self-related semantic category judgements, and self-identification tasks may be lateralised, with preferential activity in the right anterior temporal and prefrontal cortex. To test this hypothesis, participants (N = 10) were presented with morphed images of themselves (self) combined with a famous face. A further set of images was generated in which the face of one of the participant\u27s co-workers (familiar) was combined with a famous face. When compared to morphed images composed of a familiar face, the participants identified images less often as being famous if the images were composed of self, but only when responding with their left hands. This greater \u27self-effect\u27 found in left-hand responses may imply that when the right hemisphere is preferentially active, participants have a tendency to refer images to self. These data provide further support for a preferential role of the right hemisphere in processing self-related material

Hand Response Differences in a Self-Face Identification Task

Evidence has indicated that the right frontal cortex is preferentially involved in self-face recognition. To test this further, we employed a face identification task and examined hand response differences (N=10). Pictures of famous faces were combined with pictures of the participants\u27 faces (self) and their co-workers\u27 faces (familiar). These images were presented as a \u27movie\u27 in which one face transformed into another. Under the first instruction set, the movies began with either the participant\u27s face or a co-worker\u27s face, and the sequences gradually morphed into a famous face. When told to stop the movie when the face in the sequence became famous, a significantly later \u27frame\u27 was identified when the movies were composed of self-faces and the participants responded with their left hand. When the movies started with the famous faces and participants had to stop the movie when it became their own or their familiar co-worker\u27s image (Instruction set 2), a significantly earlier frame was identified in the \u27Self: Left hand\u27 condition. The data suggest that participants are inclined to identify images as their own when the right hemisphere is preferentially accessed. Copyright (C) 2000 Elsevier Science Ltd

Left Hand Advantage in a Self-Face Recognition Task

Subjects were exposed to pictures of self and others (e.g., friend, stranger, and famous people) to determine if there was an advantage in reaction time and accuracy in identifying the self. It was found that upright and inverted self-faces were identified more rapidly than non-self faces when subjects responded with their left hand, which in other tasks has corresponded with contralateral hemispheric dominance. These data suggest that self-recognition may be correlated with neural activity in the right hemisphere, and that the differences observed may not be unique to self-face recognition. These results are in agreement with previous research indicating that self-directed awareness is correlated with right prefrontal activity. Copyright (C) 1999 Elsevier Science Ltd