Pubmed du 9/04/09

Pubmed du jour

2009-04-09 12:03:50

1. Campbell JM, Marino CA. {{Brief Report: Sociometric Status and Behavioral Characteristics of Peer Nominated Buddies for a Child with Autism}}. {J Autism Dev Disord};2009 (Apr 9)

We examined social and behavioral correlates of children selected by their peers to serve as peer buddies for an unfamiliar child with autism (CWA). Participants were 293 children from two public elementary schools who completed social status, behavioral, and peer buddy nomination measures. Peer buddy nominations for a CWA were related to: (a) perceived unpopularity; (b) being viewed as helpful and smart; and (c) lacking influence regarding popularity within the classroom. In contrast, peer buddy nominations for a typical boy were related to being viewed as popular, helpful, and self-confident. Students may select a social niche for CWA based on principles of peer homophily. Limitations and suggestions for future research are discussed.

2. Grandgeorge M, Hausberger M, Tordjman S, Deleau M, Lazartigues A, Lemonnier E. {{Environmental factors influence language development in children with autism spectrum disorders}}. {PLoS ONE};2009;4(4):e4683.

BACKGROUND: While it is clearly admitted that normal behavioural development is determined by the interplay of genetic and environmental influences, this is much less the case for psychiatric disorders for which more emphasis has been given in the past decades on biological determinism. Thus, previous studies have shown that Autistic Spectrum Disorders (ASD) were not affected by parental style. However, animal research suggests that different behavioural traits can be differentially affected by genetic/environmental factors. METHODOLOGY/ PRINCIPAL FINDINGS: In the present study we hypothesized that amongst the ASD, language disorders may be more sensitive to social factors as language is a social act that develops under social influences. Using the Autism Diagnostic Interview-Revised, we compared the early characteristics of sensori-motor and language development in a large sample of children with ASD (n = 162) with parents belonging to different levels of education. The results showed that children raised by parents with a high level of education displayed earlier language development. Moreover, they showed earlier first words and phrases if their mother was at a high level of education, which reveals an additional gender effect. CONCLUSIONS/SIGNIFICANCE: To our knowledge this study may trigger important new lines of thought and research, help equilibrate social and purely biological perspectives regarding ASD and bring new hopes for environmentally based therapies.

3. Koegel RL, Vernon TW, Koegel LK. {{Improving Social Initiations in Young Children with Autism Using Reinforcers with Embedded Social Interactions}}. {J Autism Dev Disord};2009 (Apr 9)

Children with autism often exhibit low levels of social engagement, decreased levels of eye contact, and low social affect. However, both the literature and our direct clinical observations suggest that some components of intervention procedures may result in improvement in child-initiated social areas. Using an ABAB research design with three children with autism, this study systematically assessed whether embedding social interactions into reinforcers, delivered during language intervention, would lead to increased levels of child-initiated social behaviors. We compared this condition with a language intervention condition that did not embed social interactions into the reinforcers. Results indicated that embedding social interactions into the reinforcers resulted in increases in child-initiated social engagement during communication, improved nonverbal dyadic orienting, and improvements in general child affect. Theoretical and applied implications are discussed.

4. Lim SM, Kim HJ, Nam M, Chung JH, Park YH. {{Association study of DISC1 in Korean population with autism spectrum disorders}}. {Psychiatr Genet};2009 (Apr 4)

5. Lind SE, Bowler DM. {{Recognition Memory, Self-Other Source Memory, and Theory-of-Mind in Children with Autism Spectrum Disorder}}. {J Autism Dev Disord};2009 (Apr 8)

This study investigated semantic and episodic memory in autism spectrum disorder (ASD), using a task which assessed recognition and self-other source memory. Children with ASD showed undiminished recognition memory but significantly diminished source memory, relative to age- and verbal ability-matched comparison children. Both children with and without ASD showed an « enactment effect », demonstrating significantly better recognition and source memory for self-performed actions than other-person-performed actions. Within the comparison group, theory-of-mind (ToM) task performance was significantly correlated with source memory, specifically for other-person-performed actions (after statistically controlling for verbal ability). Within the ASD group, ToM task performance was not significantly correlated with source memory (after controlling for verbal ability). Possible explanations for these relations between source memory and ToM are considered.

6. McAlonan GM, Cheung C, Cheung V, Wong N, Suckling J, Chua SE. {{Differential effects on white-matter systems in high-functioning autism and Asperger’s syndrome}}. {Psychol Med};2009 (Apr 9):1-9.

BACKGROUND: Whether autism spectrum maps onto a spectrum of brain abnormalities and whether Asperger’s syndrome (ASP) is distinct from high-functioning autism (HFA) are debated. White-matter maldevelopment is associated with autism and disconnectivity theories of autism are compelling. However, it is unknown whether children with ASP and HFA have distinct white-matter abnormalities.MethodVoxel-based morphometry mapped white-matter volumes across the whole brain in 91 children. Thirty-six had autism spectrum disorder. A history of delay in phrase speech defined half with HFA; those without delay formed the ASP group. The rest were typically developing children, balanced for age, IQ, gender, maternal language and ethnicity. White-matter volumes in HFA and ASP were compared and each contrasted with controls. RESULTS: White-matter volumes around the basal ganglia were higher in the HFA group than ASP and higher in both autism groups than controls. Compared with controls, children with HFA had less frontal and corpus callosal white matter in the left hemisphere; those with ASP had less frontal and corpus callosal white matter in the right hemisphere with more white matter in the left parietal lobe. CONCLUSIONS: HFA involved mainly left hemisphere white-matter systems; ASP affected predominantly right hemisphere white-matter systems. The impact of HFA on basal ganglia white matter was greater than ASP. This implies that aetiological factors and management options for autism spectrum disorders may be distinct. History of language acquisition is a potentially valuable marker to refine our search for causes and treatments in autism spectrum.

7. Russo N, Zecker S, Trommer B, Chen J, Kraus N. {{Effects of Background Noise on Cortical Encoding of Speech in Autism Spectrum Disorders}}. {J Autism Dev Disord};2009 (Apr 8)

This study provides new evidence of deficient auditory cortical processing of speech in noise in autism spectrum disorders (ASD). Speech-evoked responses (~100-300 ms) in quiet and background noise were evaluated in typically-developing (TD) children and children with ASD. ASD responses showed delayed timing (both conditions) and reduced amplitudes (quiet) compared to TD responses. As expected, TD responses in noise were delayed and reduced compared to quiet responses. However, minimal quiet-to-noise response differences were found in children with ASD, presumably because quiet responses were already severely degraded. Moreover, ASD quiet responses resembled TD noise responses, implying that children with ASD process speech in quiet only as well as TD children do in background noise.

8. Sajdel-Sulkowska EM, Xu M, Koibuchi N. {{Increase in Cerebellar Neurotrophin-3 and Oxidative Stress Markers in Autism}}. {Cerebellum};2009 (Apr 9)

Autism is a neurodevelopmental disorder characterized by social and language deficits, ritualistic-repetitive behaviors and disturbance in motor functions. Data of imaging, head circumference studies, and Purkinje cell analysis suggest impaired brain growth and development. Both genetic predisposition and environmental triggers have been implicated in the etiology of autism, but the underlying cause remains unknown. Recently, we have reported an increase in 3-nitrotyrosine (3-NT), a marker of oxidative stress damage to proteins in autistic cerebella. In the present study, we further explored oxidative damage in the autistic cerebellum by measuring 8-hydroxydeoxyguanosine (8-OH-dG), a marker of DNA modification, in a subset of cases analyzed for 3-NT. We also explored the hypothesis that oxidative damage in autism is associated with altered expression of brain neurotrophins critical for normal brain growth and differentiation. The content of 8-OH-dG in cerebellar DNA isolated by the proteinase K method was measured using an enzyme-linked immunosorbent assay (ELISA); neurotrophin-3 (NT-3) levels in cerebellar homogenates were measured using NT-3 ELISA. Cerebellar 8-OH-dG showed trend towards higher levels with the increase of 63.4% observed in autism. Analysis of cerebellar NT-3 showed a significant (p = 0.034) increase (40.3%) in autism. Furthermore, there was a significant positive correlation between cerebellar NT-3 and 3-NT (r = 0.83; p = 0.0408). These data provide the first quantitative measure of brain NT-3 and show its increase in the autistic brain. Altered levels of brain NT-3 are likely to contribute to autistic pathology not only by affecting brain axonal targeting and synapse formation but also by further exacerbating oxidative stress and possibly contributing to Purkinje cell abnormalities.