Pubmed du 14/09/10

Pubmed du jour

2010-09-14 12:03:50

1. Ashwood P, Krakowiak P, Hertz-Picciotto I, Hansen R, Pessah IN, Water JV. {{Altered T cell responses in children with autism}}. {Brain Behav Immun} (Sep 9)

Autism spectrum disorders (ASD) are characterized by impairment in social interactions, communication deficits, and restricted repetitive interests and behaviors. A potential etiologic role for immune dysfunction in ASD has been suggested. Dynamic adaptive cellular immune function was investigated in 66 children with a confirmed diagnosis of ASD and 73 confirmed typically developing (TD) controls 2-5 years-of-age. In vitro stimulation of peripheral blood mononuclear cells with PHA and tetanus was used to compare group-associated cellular responses. The production of GM-CSF, TNFalpha, and IL-13 were significantly increased whereas IL-12p40 was decreased following PHA stimulation in ASD relative to TD controls. Induced cytokine production was associated with altered behaviors in ASD children such that increased pro-inflammatory or TH1 cytokines were associated with greater impairments in core features of ASD as well as aberrant behaviors. In contrast, production of GM-CSF and T(H)2 cytokines were associated with better cognitive and adaptive function. Following stimulation, the frequency of CD3+, CD4(+) and CD8(+) T cells expressing activation markers CD134 and CD25 but not CD69, HLA-DR or CD137 were significantly reduced in ASD, and suggests an altered activation profile for T cells in ASD. Overall these data indicate significantly altered adaptive cellular immune function in children with ASD that may reflect dysfunctional immune activation, along with evidence that these perturbations may be linked to disturbances in behavior and developmental functioning. Further longitudinal analyzes of cellular immunity profiles would delineate the relationship between immune dysfunction and the progression of behavioral and developmental changes throughout the course of this disorder.

2. Hodgetts S, Magill-Evans J, Misiaszek JE. {{Weighted Vests, Stereotyped Behaviors and Arousal in Children with Autism}}. {J Autism Dev Disord} (Sep 14)

The homeostatic theory of stereotyped behaviors assumes that these behaviors modulate arousal. Weighted vests are used to decrease stereotyped behaviors in persons with autism because the input they provide is thought to serve the same homeostatic function. This small-n, randomized and blinded study measured the effects of wearing a weighted vest on stereotyped behaviors and heart rate for six children with autism in the classroom. Weighted vests did not decrease motoric stereotyped behaviors in any participant. Verbal stereotyped behaviors decreased in one participant. Weighted vests did not decrease heart rate. Heart rate increased in one participant. Based on this protocol, the use of weighted vests to decrease stereotyped behaviors or arousal in children with autism in the classroom was not supported.

3. Jou RJ, Minshew NJ, Keshavan MS, Vitale MP, Hardan AY. {{Enlarged Right Superior Temporal Gyrus in Children and Adolescents with Autism}}. {Brain Res} (Sep 9)

The superior temporal gyrus has been implicated in language processing and social perception. Therefore, anatomical abnormalities of this structure may underlie some of the deficits observed in autism, a severe neurodevelopmental disorder characterized by impairments in social interaction and communication. In this study, volumes of the left and right superior temporal gyri were measured using magnetic resonance imaging obtained from 18 boys with high-functioning autism (mean age=13.5 +/-3.4years; full-scale IQ=103.6 +/-13.4) and 19 healthy controls (mean age=13.7 +/-3.0years; full-scale IQ=103.9 +/-10.5), group-matched on age, gender, and handedness. When compared to the control group, right superior temporal gyral volumes were significantly increased in the autism group after controlling for age and total brain volume. There was no significant difference in the volume of the left superior temporal gyrus. Post-hoc analysis revealed significant increase of posterior superior temporal gyral volume in the autism group, before and after controlling for age and total brain volume. Examination of the symmetry index for the superior temporal gyral volumes did not yield statistically significant between-group differences. Findings from this preliminary investigation suggest the existence of volumetric alterations in the right superior temporal gyrus in children and adolescents with autism, providing support for a neuroanatomical basis of the social perceptual deficits characterizing this severe neurodevelopmental disorder.

4. Krebs JF, Biswas A, Pascalis O, Kamp-Becker I, Remschmidt H, Schwarzer G. {{Face Processing in Children with Autism Spectrum Disorder: Independent or Interactive Processing of Facial Identity and Facial Expression?}}. {J Autism Dev Disord} (Sep 14)

The current study investigated if deficits in processing emotional expression affect facial identity processing and vice versa in children with autism spectrum disorder. Children with autism and IQ and age matched typically developing children classified faces either by emotional expression, thereby ignoring facial identity or by facial identity disregarding emotional expression. Typically developing children processed facial identity independently from facial expressions but processed facial expressions in interaction with identity. Children with autism processed both facial expression and identity independently of each other. They selectively directed their attention to one facial parameter despite variations in the other. Results indicate that there is no interaction in processing facial identity and emotional expression in autism spectrum disorder.

5. Lane AE, Dennis SJ, Geraghty ME. {{Brief Report: Further Evidence of Sensory Subtypes in Autism}}. {J Autism Dev Disord} (Sep 14)

Distinct sensory processing (SP) subtypes in autism have been reported previously. This study sought to replicate the previous findings in an independent sample of thirty children diagnosed with an Autism Spectrum Disorder. Model-based cluster analysis of parent-reported sensory functioning (measured using the Short Sensory Profile) confirmed the triad of sensory subtypes reported earlier. Subtypes were differentiated from each other based on degree of SP dysfunction, taste/smell sensitivity and vestibular/proprioceptive processing. Further elucidation of two of the subtypes was also achieved in this study. Children with a primary pattern of sensory-based inattention could be further described as sensory seekers or non-seekers. Children with a primary pattern of vestibular/proprioceptive dysfunction were also differentiated on movement and tactile sensitivity.

6. Lickenbrock DM, Ekas NV, Whitman TL. {{Feeling Good, Feeling Bad: Influences of Maternal Perceptions of the Child and Marital Adjustment on Well-being in Mothers of Children with an Autism Spectrum Disorder}}. {J Autism Dev Disord} (Sep 14)

Mothers of children with an autism spectrum disorder (n = 49) participated in a 30-day diary study which examined associations between mothers’ positive and negative perceptions of their children, marital adjustment, and maternal well-being. Hierarchical linear modeling results revealed that marital adjustment mediated associations between positive perceptions and maternal well-being. Mothers who reported higher levels of positive perceptions of the child were higher in marital adjustment and well-being. Results also revealed that marital adjustment moderated the relation between negative perceptions and negative maternal affect. Mothers low in marital adjustment had a positive association between negative maternal perceptions of the child and negative maternal affect. These findings highlight the dynamic roles that mothers’ perceptions and marital adjustment play in determining maternal psychological outcomes.

7. Lyall K, Pauls DL, Santangelo SL, Spiegelman D, Ascherio A. {{Erratum to: Maternal Early Life Factors Associated with Hormone Levels and the Risk of Having a Child with an Autism Spectrum Disorder in the Nurses Health Study II}}. {J Autism Dev Disord} (Sep 14)

8. Thomas C, Humphreys K, Jung KJ, Minshew N, Behrmann M. {{The anatomy of the callosal and visual-association pathways in high-functioning autism: A DTI tractography study}}. {Cortex} (Aug 3)

There is increasing recognition that many of the core behavioral impairments that characterize autism potentially emerge from poor neural synchronization across nodes comprising dispersed cortical networks. A likely candidate for the source of this atypical functional connectivity in autism is an alteration in the structural integrity of intra- and inter-hemispheric white matter (WM) tracts that form large-scale cortical networks. To test this hypothesis, in a group of adults with high-functioning autism (HFA) and matched control participants, we used diffusion tensor tractography to compare the structural integrity of three intra-hemispheric visual-association WM tracts, the inferior longitudinal fasciculus (ILF), the inferior fronto-occipito fasciculus (IFOF) and the uncinate fasciculus (UF), with the integrity of three sub-portions of the major inter-hemispheric fiber tract, the corpus callosum. Compared with the control group, the HFA group evinced an increase in the volume of the intra-hemispheric fibers, particularly in the left hemisphere, and a reduction in the volume of the forceps minor (F-Mi) and body of the corpus callosum. The reduction in the volume of the F-Mi also correlated with an increase in repetitive and stereotypical behavior as measured by the Autism Diagnostic Interview. These findings suggest that the abnormalities in the integrity of key inter- and intra-hemispheric WM tracts may underlie the atypical information processing observed in these individuals.