Pubmed du 17/10/13

Pubmed du jour

2013-10-17 12:03:50

1. Ahmed AA, Vander Wyk BC. {{Neural processing of intentional biological motion in unaffected siblings of children with autism spectrum disorder: An fMRI study}}. {Brain Cogn};2013 (Oct 12);83(3):297-306.

Despite often showing behaviorally typical levels of social cognitive ability, unaffected siblings of children with autism spectrum disorder have been found to show similar functional and morphological deficits within brain regions associated with social processing. They have also been reported to show increased activation to biological motion in these same regions, such as the posterior superior temporal sulcus (pSTS), relative to both children with autism and control children. It has been suggested that this increased activation may represent a compensatory reorganization of these regions as a result of the highly heritable genetic influence of autism. However, the response patterns of unaffected siblings in the domain of action perception are unstudied, and the phenomenon of compensatory activation has not yet been replicated. The present study used functional magnetic resonance imaging to determine the neural responses to intentional biological actions in 22 siblings of children with autism and 22 matched controls. The presented actions were either congruent or incongruent with the actor’s emotional cue. Prior studies reported that typically developing children and adults, but not children with autism, show increased activation to incongruent actions (relative to congruent), within the pSTS and dorsolateral prefrontal cortex. We report that unaffected siblings did not show a compensatory response, or a preference for incongruent over congruent trials, in any brain region. Moreover, interaction analyses revealed a sub-region of the pSTS in which control children showed an incongruency preference to a significantly greater degree than siblings, which suggests a localized deficit in siblings. A sample of children with autism also did not show differential activation in the pSTS, providing further evidence that it is an area of selective disruption in children with autism and siblings. While reduced activation to both conditions was unique to the autism sample, lack of differentiation to incongruent and congruent intentional actions was common to both children with ASD and unaffected siblings.

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2. Conti E, Mazzotti S, Calderoni S, Saviozzi I, Guzzetta A. {{Are children born after assisted reproductive technology at increased risk of autism spectrum disorders? A systematic review}}. {Hum Reprod};2013 (Oct 15)

STUDY QUESTION: Are children born after assisted reproductive technology (ART) at increased risk of autism spectrum disorders (ASD)? SUMMARY ANSWER: There is no evidence that ART significantly increases the risk of ASD in the offspring. WHAT IS KNOWN ALREADY: A few systematic reviews have explored the correlation between assisted conception and ASD with inconclusive results, partly due to the heterogeneity of diagnostic criteria and methodology in the different studies. STUDY DESIGN, SIZE, DURATION: Systematic review of 7 observational studies (2 cohort and 5 case-control) encompassing 9216 subjects diagnosed with ASD published since 2000. MATERIALS, SETTING, METHODS: Literature searches were conducted to retrieve observational studies on the risk of ASD in ART population. Databases searched included PubMed, EMBASE and PsycINFO. In order to obtain more consistent results, we only included the studies in which (i) subjects with either infantile autism or ASD could be identified according to international classification systems and (ii) the diagnosis was obtained from hospital records. Seven studies matched the inclusion criteria. MAIN RESULTS AND THE ROLE OF CHANCE: Four out of seven studies, including the two with the best quality scores, did not show an association between ART and ASD. The two papers supporting an increased risk of autism following ART had the lowest quality scores, due to major methodological limitations. Only one paper showed a protective role of ART. LIMITATIONS, REASONS FOR CAUTION: In spite of the strict inclusion criteria applied as to the diagnosis of ASD, the papers selected are heterogeneous in many aspects including study design, definitions of ART, data source and analysed confounders. WIDER IMPLICATIONS OF THE FINDINGS: At present, there is no evidence that ART is significantly associated with ASD and hence that current health policies should be modified. The divergent results of some of the studies suggest that further prospective, large and high-quality studies are still needed. STUDY FUNDING/COMPETING INTEREST(S): This work was supported, in part, by the Italian Ministry of Health and by Tuscany Region. The authors have no competing interests to declare. TRIAL REGISTRATION NUMBER: N/A.

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3. De Angelis M, Piccolo M, Vannini L, Siragusa S, De Giacomo A, Serrazzanetti DI, Cristofori F, Guerzoni ME, Gobbetti M, Francavilla R. {{Fecal Microbiota and Metabolome of Children with Autism and Pervasive Developmental Disorder Not Otherwise Specified}}. {PLoS One};2013;8(10):e76993.

This study aimed at investigating the fecal microbiota and metabolome of children with Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS) and autism (AD) in comparison to healthy children (HC). Bacterial tag-encoded FLX-titanium amplicon pyrosequencing (bTEFAP) of the 16S rDNA and 16S rRNA analyses were carried out to determine total bacteria (16S rDNA) and metabolically active bacteria (16S rRNA), respectively. The main bacterial phyla (Firmicutes, Bacteroidetes, Fusobacteria and Verrucomicrobia) significantly (P<0.05) changed among the three groups of children. As estimated by rarefaction, Chao and Shannon diversity index, the highest microbial diversity was found in AD children. Based on 16S-rRNA and culture-dependent data, Faecalibacterium and Ruminococcus were present at the highest level in fecal samples of PDD-NOS and HC children. Caloramator, Sarcina and Clostridium genera were the highest in AD children. Compared to HC, the composition of Lachnospiraceae family also differed in PDD-NOS and, especially, AD children. Except for Eubacterium siraeum, the lowest level of Eubacteriaceae was found on fecal samples of AD children. The level of Bacteroidetes genera and some Alistipes and Akkermansia species were almost the highest in PDD-NOS or AD children as well as almost all the identified Sutterellaceae and Enterobacteriaceae were the highest in AD. Compared to HC children, Bifidobacterium species decreased in AD. As shown by Canonical Discriminant Analysis of Principal Coordinates, the levels of free amino acids and volatile organic compounds of fecal samples were markedly affected in PDD-NOS and, especially, AD children. If the gut microbiota differences among AD and PDD-NOS and HC children are one of the concomitant causes or the consequence of autism, they may have implications regarding specific diagnostic test, and/or for treatment and prevention.

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4. Ellawadi AB, Ellis Weismer S. {{Assessing Gestures in Young Children with Autism Spectrum Disorders}}. {J Speech Lang Hear Res};2013 (Oct 15)

PURPOSE: To determine whether scoring of the gestures point, give, and show were correlated across measurement tools used to assess gesture production in children with an Autism Spectrum Disorder (ASD). METHOD: Seventy-eight children with an ASD between the ages of 23 to 37 months participated. Correlational analyses were conducted to determine whether performance of three key gestures related to joint attention and behavior regulation (point, give, show) were correlated across three different measurement tools: the Autism Diagnostic Observation Schedule, the Early Social Communication Scale, and the MacArthur-Bates Communicative Developmental Inventory: Words and Gestures. To establish whether different measures were related at different points in development, children were subdivided into two groups based on their expressive language levels. RESULTS: The scoring of gesture performance was not entirely consistent across assessment methods. The score that a child received appeared to be influenced by theoretical perspective, gesture definition, and assessment methodology, as well as developmental level. CONCLUSION: When assessing the gestures of children with ASD clinicians should determine what aspects of gesture they are interested in profiling, gather data from multiple sources, and consider performance in light of the measurement tool.

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5. Ho HS, Yi H, Griffiths S, Chan DF, Murray S. {{‘Do It Yourself’ in the parent-professional partnership for the assessment and diagnosis of children with autism spectrum conditions in Hong Kong: A qualitative study}}. {Autism};2013 (Oct 15)

Timely and appropriate care for children with autism spectrum conditions is affected by the interaction between healthcare professionals and parents. Despite the importance of the parent-professional partnership, there is a dearth of cultural-specific data on parent-professional partnership in the Chinese context. We conducted 10 in-depth life-history interviews with parents of children with autism spectrum conditions in Hong Kong who were diagnosed during preschool years. Using an interpretative phenomenological analytic method, five themes were constructed to represent the context of parent-professional partnership in Hong Kong along the pathway of seeking a diagnosis: (a) access to the assessment and diagnosis of autism spectrum conditions, (b) multiple procedures of assessment, (c) consultation prior to diagnosis and assessment, (d) communication of diagnosis and assessment result and (e) post-assessment isolation. Parental narratives highlight the important domains of parent-professional partnership and reflect the complexity of diagnosis and the lack of a cohesive system. For many parents, the assessment procedure was marred by a series of obstacles, which were further exacerbated by a poorly developed parent-professional partnership. Suggestions for parent-professional partnership development include establishing an evidence-based best practice guideline for Hong Kong, creating pre-assessment information workshops for parents to attend and equipping professionals with knowledge about autism spectrum conditions and enhanced communication skills.

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6. Lokanga R, Zhao XN, Usdin K. {{The Mismatch Repair Protein MSH2 is Rate-Limiting for Repeat Expansion in a Fragile X Premutation Mouse Model}}. {Hum Mutat};2013 (Oct 15)

Fragile X-associated tremor and ataxia syndrome, Fragile X-associated primary ovarian insufficiency and Fragile X syndrome are Repeat Expansion Diseases caused by expansion of a CGG*CCG-repeat microsatellite in the 5′ UTR of the FMR1 gene. To help understand the expansion mechanism responsible for these disorders we have crossed mice containing approximately 147 CGG*CCG repeats in the endogenous murine Fmr1 gene with mice containing a null mutation in the gene encoding the mismatch repair protein MSH2. MSH2 mutations are associated with elevated levels of generalized microsatellite instability. However, we show here for the first time that in the FX mouse model all maternally and paternally transmitted expansions require Msh2. Even the loss of one Msh2 allele reduced the intergenerational expansion frequency significantly. Msh2 is also required for all somatic expansions and loss of even one functional Msh2 allele reduced the extent of somatic expansion in some organs. Tissues with lower tissue levels of MSH2 were more sensitive to the loss of a single Msh2 allele. This suggests that MSH2 is rate-limiting for expansion in this mouse model and that MSH2 levels may be a key factor that accounts for tissue-specific differences in expansion risk. This article is protected by copyright. All rights reserved.

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7. Matsuba CA. {{Assessment of autism in children with visual impairment}}. {Dev Med Child Neurol};2013 (Oct 15)

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8. Tordjman S, Najjar I, Bellissant E, Anderson GM, Barburoth M, Cohen D, Jaafari N, Schischmanoff O, Fagard R, Lagdas E, Kermarrec S, Ribardiere S, Botbol M, Fougerou C, Bronsard G, Vernay-Leconte J. {{Advances in the Research of Melatonin in Autism Spectrum Disorders: Literature Review and New Perspectives}}. {Int J Mol Sci};2013;14(10):20508-20542.

Abnormalities in melatonin physiology may be involved or closely linked to the pathophysiology and behavioral expression of autistic disorder, given its role in neurodevelopment and reports of sleep-wake rhythm disturbances, decreased nocturnal melatonin production, and beneficial therapeutic effects of melatonin in individuals with autism. In addition, melatonin, as a pineal gland hormone produced from serotonin, is of special interest in autistic disorder given reported alterations in central and peripheral serotonin neurobiology. More specifically, the role of melatonin in the ontogenetic establishment of circadian rhythms and the synchronization of peripheral oscillators opens interesting perspectives to ascertain better the mechanisms underlying the significant relationship found between lower nocturnal melatonin excretion and increased severity of autistic social communication impairments, especially for verbal communication and social imitative play. In this article, first we review the studies on melatonin levels and the treatment studies of melatonin in autistic disorder. Then, we discuss the relationships between melatonin and autistic behavioral impairments with regard to social communication (verbal and non-verbal communication, social interaction), and repetitive behaviors or interests with difficulties adapting to change. In conclusion, we emphasize that randomized clinical trials in autism spectrum disorders are warranted to establish potential therapeutic efficacy of melatonin for social communication impairments and stereotyped behaviors or interests.

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9. Wass SV, Porayska-Pomsta K. {{The uses of cognitive training technologies in the treatment of autism spectrum disorders}}. {Autism};2013 (Oct 15)

In this review, we focus on research that has used technology to provide cognitive training – i.e. to improve performance on some measurable aspect of behaviour – in individuals with autism spectrum disorders. We review technology-enhanced interventions that target three different cognitive domains: (a) emotion and face recognition, (b) language and literacy, and (c) social skills. The interventions reviewed allow for interaction through different modes, including point-and-click and eye-gaze contingent software, and are delivered through diverse implementations, including virtual reality and robotics. In each case, we examine the evidence of the degree of post-training improvement observed following the intervention, including evidence of transfer to altered behaviour in ecologically valid contexts. We conclude that a number of technological interventions have found that observed improvements within the computerised training paradigm fail to generalise to altered behaviour in more naturalistic settings, which may result from problems that people with autism spectrum disorders experience in generalising and extrapolating knowledge. However, we also point to several promising findings in this area. We discuss possible directions for future work.

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10. Williams DM, Jarrold C, Grainger C, Lind SE. {{Diminished Time-Based, but Undiminished Event-Based, Prospective Memory Among Intellectually High-Functioning Adults With Autism Spectrum Disorder: Relation to Working Memory Ability}}. {Neuropsychology};2013 (Oct 14)

Objective: Prospective memory (PM) is the ability to remember to carry out an intended action. Working memory is the ability to store information in mind while processing potentially distracting information. The few previous studies of PM in autism spectrum disorder (ASD) have yielded inconsistent findings. Studies of working memory ability in ASD have suggested a selective impairment of « visual working memory. » However, it remains unclear whether any such impairment is the result of diminished (domain-specific; visual/verbal) storage capacity or diminished (domain-general) processing capacity. We aim to clarify these issues and explore the relation between PM and working memory in ASD. Method: Seventeen adults with ASD and 17 age- and IQ-matched comparison participants completed experimental measures of both event-based (perform action x when event y occurs) and time-based (perform action a at time b) PM, plus a self-report measure of PM skills. Participants also completed a working memory test battery. Results: Participants with ASD self-reported diminished PM skill, and showed diminished performance on the time-based, but not event-based, PM task. On the working memory test battery, visual but not verbal storage capacity was diminished among participants with ASD, as was processing ability. Whereas visual storage was associated with event-based PM task performance among comparison participants, verbal storage was associated among ASD participants. Conclusions: ASD appears to involve a selective deficit in time-based PM and a selective difficulty with aspects of working memory that depend on the storage of visual information. However, event-based PM may be achieved through compensatory strategies in ASD. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

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