Pubmed du 31/08/10

Pubmed du jour

2010-08-31 12:03:50

1. {{International society for autism research news}}. {Autism Res} (Aug);3(4):201.

2. Burke RV, Andersen MN, Bowen SL, Howard MR, Allen KD. {{Evaluation of two instruction methods to increase employment options for young adults with autism spectrum disorders}}. {Res Dev Disabil} (Aug 26)

We evaluated the efficacy of a vocational training program including behavioral skills training, and a « performance cue system » (i.e., a proprietary iPhone application adapted for the study) to teach targeted social-vocational skills to six young adults with an Autism Spectrum Disorder. In two separate studies, participants were employed to assist in the delivery of a fire safety education program. Participants were asked to wear an inflatable firefighter WalkAround((R)) mascot costume and to perform 63 scripted behaviors in coordination with a fire prevention specialist who was the lead program presenter. In Study 1, three participants were initially exposed to established company training procedures comprised of behavioral skills training components to determine whether they met mastery of the skills. If necessary to reach criteria, participants were then exposed to a performance cue system. In Study 2, three additional participants were provided with the performance cue system alone, and then behavioral skills training if required. A single case, multiple-baseline design across subjects was used to evaluate efficacy of each intervention. Results indicate that 5 of 6 participants reached criterion only after introduction of the cue system while the sixth reached criterion with behavioral skills training alone. The program received high satisfaction ratings from participants, their parents, and consumers. Implications and potential use of the PCS in other employment settings are discussed.

3. Cook EH, Jr. {{Autism spectrum disorder: unbroken mirror neurons; rare copy number variants}}. {Autism Res} (Aug);3(4):196-197.

4. Croonenberghs J, Grieken SV, Wauters A, West DV, Brouw L, Maes M. {{Serum testosterone concentration in male autistic youngsters}}. {Neuro Endocrinol Lett} (Aug 30);31(4)

OBJECTIVE: Research on the biological pathophysiology of autism has found some evidence that alterations in androgenic hormones may play a role in the pathophysiology of that disorder. We studied morning concentrations of serum testosterone in a very homogenic group of postpubertal youngsters with autism and a group of normal controls. METHODS: This study examines the serum testosterone concentration on 9 consecutive time points between 08.00 AM and 12.00 AM in 18 high- functioning male youngsters with autism (age 12-18) and 22 healthy volunteers participated in this study. All subjects passed the onset of puberty (Tanner-stage III-IV) and were of the Caucasian race. RESULTS: Repeated measures ANOVA revealed a significant time effect, with a decline in the testosterone concentration during the test and time X diagnosis interaction.The total testosterone concentration was significantly lower in the autism group compared to the group of normal controls. CONCLUSIONS: The significant decrease in serum testosterone concentration in male youngsters with autism suggest that the turnover of testosterone may take part in the pathophysiology of autism. Suggestions for further research are discussed.

5. Fishman I, Yam A, Bellugi U, Lincoln A, Mills D. {{Contrasting patterns of language-associated brain activity in autism and Williams syndrome}}. {Soc Cogn Affect Neurosci} (Aug 27)

Two neurodevelopmental disorders, Williams syndrome (WS) and autism, are both commonly described as having opposite social profiles: social avoidance in autism vs hypersociability in individuals with WS. The goal of this study was to contrast the brain activity associated with language processing in these two populations, in order to understand the very likely interplay between the use of language and the sociability dimension, on which these disorders diverge. Towards this aim, the N400 component of the event-related potentials was used to quantify the processing of semantic integration in these two populations. Results revealed that individuals with WS showed a significantly larger N400 effect, as compared to both typical controls and individuals with autism, while the latter group demonstrated the smallest N400 effect. The findings demonstrate quite opposite profiles of neural correlates of language processing in WS and autism, mirroring their contrasting social phenotypes.

6. Gana S, Panizzon M, Fongaro D, Selicorni A, Memo L, Scandurra V, Vannucci C, Bigozzi M, Scordo MR. {{Nicolaides-Baraitser syndrome: two new cases with autism spectrum disorder}}. {Clin Dysmorphol} (Aug 27)

Nicolaides-Baraitser syndrome is a rare clinical condition characterized by mental retardation with impairment of expressive language, short stature, microcephaly, sparse hair, typical facial dysmorphisms, and interphalangeal joint swellings. To date 24 cases have been reported, most of them being sporadic. The genetic background of Nicolaides-Baraitser syndrome is unclear in terms of cause and mode of inheritance, one of the more probable explanations is de novo mutation of a dominant gene. Some reported patients presented autistic features, although in none of these patients was the diagnosis of autism spectrum disorder formally made. We describe two unrelated patients with clinical features suggesting Nicolaides-Baraitser syndrome and, in addition, autism spectrum disorder is defined by the presence of the three cardinal core features: qualitative impairments in social, communicative, and behavioral development.

7. Hebert KJ, Miller LL, Joinson CJ. {{Association of autistic spectrum disorder with season of birth and conception in a UK cohort}}. {Autism Res} (Aug);3(4):185-190.

Purpose: To examine the association between autistic spectrum disorder (ASD) and seasons of conception and birth in a UK birth cohort: Avon Longitudinal Study of Parents and Children (ALSPAC). Methods: Seasons of conception and birth were compared in children with and without ASD with season grouped as follows: spring (March-May); summer (June-August); autumn (September-November) and winter (December-February). Results: A total of 86 children with ASD were identified in the ALSPAC cohort giving a prevalence of ASD of 61.9 per 10,000. There was some evidence for an excess of children with ASD being conceived during the summer months with a rate per 1,000 conceptions of 9.5 in summer compared to 5.1, 4.6, 5.7 in spring, autumn and winter, respectively. A doubling of the odds was suggested for summer compared to autumn (Odds ratio 2.08 [1.18, 3.70]). In agreement with previous research, there was a corresponding peak in spring births. Conclusion: Conception during the summer months was associated with an over-representation of children with ASD in this UK birth cohort. There was also an association between ASD and spring births. Further investigation of seasonal influences on the aetiology of autism is required to identify possible factors in the environment, and their mechanisms and timings.

8. Kaluzna-Czaplinska J, Socha E, Rynkowski J. {{Determination of homovanillic acid and vanillylmandelic acid in urine of autistic children by gas chromatography/mass spectrometry}}. {Med Sci Monit} (Aug 7);16(9):CR445-450.

Background: Studies suggest dopamine nervous systems are involved in the pathogenesis of autistic disorder. Quantification of urinary homovanillic acid (HVA) and vanillylmandelic acid (VMA) can be a very important tool in the study of disorders of dopamine metabolism in autistic children.<br /> Material/Methods: The urine specimens were collected from 20 autistic children and 36 neurologically normal children. Urinary HVA and VMA were simultaneously analyzed by gas chromatography-mass spectrometry. The method involves extraction of HVA and VMA from urinary samples and derivatization to N,O-bis(trimethylsilyl)trifluoroacetamide derivatives.<br /> Results: The detection limits are 0.15 microg/mL and 0.23 microg/mL for VMA and HVA, respectively. The levels of HVA and VMA were higher in the urine of autistic children (28.8+/-15.5 micromol/mmol creatinine and 22.2+/-13.0 micromol/mmol creatinine, respectively) compared with those of the generally healthy children (4.6+/-0.7 micromol/mmol creatinine for HVA and 3.8+/-0.6 micromol/mmol creatinine for VMA).<br /> Conclusions: We proposed a simple, rapid method for a routine analysis of human urine to detect HVA and VMA related to an abnormal functional imbalance of the dopamine system, and showed our experience of application of this method to patients with a diagnosis of autism spectrum disorders. These results suggest significant differences in the levels of HVA and VMA between autistic and healthy children.<br />

9. Santos M, Uppal N, Butti C, Wicinski B, Schmeidler J, Giannakopoulos P, Heinsein H, Schmitz C, Hof PR. {{Von Economo neurons in autism: A stereologic study of the frontoinsular cortex in children}}. {Brain Res} (Aug 26)

The presence of von Economo neurons (VENs) in the frontoinsular cortex (FI) has been linked to a possible role in the integration of bodily feelings, emotional regulation, and goal-directed behaviors. They have also been implicated in fast intuitive evaluation of complex social situations. Several studies reported a decreased number of VENs in neuropsychiatric diseases in which the « embodied » dimension of social cognition is markedly affected. Neuropathological analyses of VENs in patients with autism are few and did not report alterations in VEN numbers. In this study we re-evaluated the possible presence of changes in VEN numbers and their relationship with the diagnosis of autism. Using a stereologic approach we quantified VENs and pyramidal neurons in layer V of FI in postmortem brains of four young patients with autism and three comparably aged controls. We also investigated possible autism-related differences in FI layer V volume. Patients with autism consistently had a significantly higher ratio of VENs to pyramidal neurons (p=0.020) than control subjects. This result may reflect the presence of neuronal overgrowth in young patients with autism, and may also be related to alterations in migration, cortical lamination, and apoptosis. Higher numbers of VENs in the FI of patients with autism may also underlie a heightened interoception, described in some clinical observations.

10. Tager-Flusberg H. {{The origins of social impairments in autism spectrum disorder: Studies of infants at risk}}. {Neural Netw} (Aug 6)

Core impairments in social and communicative behaviors are among the defining characteristics of autism spectrum disorder (ASD), making this a model syndrome for investigating the mechanisms that underlie social cognition and behavior. Current research is exploring the origins of social impairments in prospective longitudinal studies of infants who are at high risk for ASD, defined as having an older sibling with the disorder. Behavioral studies that have followed these infants through to outcomes have found that during the early months of life they are no different from typically developing infants; they are socially interested, engaged and enjoy interactions with people. By the end of the first year risk signs for later ASD can be identified though no single marker has been identified. It seems that an aggregate of risk markers together may be needed to predict ASD. Other studies have compared infants at risk for ASD to low risk controls to identify neurocognitive endophenotypes. Several differences in subtle aspects of behavior and in brain organization have been found in infants younger than 12 months, though it is not known whether these differences are also risk markers for a later ASD diagnosis. The findings from these lines of research are used to provide a new view of ASD, as a disorder defined on the basis of alterations in the developmental trajectories across multiple domains. ASD is an emergent disorder that is characterized by the loss of social communication skills in the period between 9 and 24 months. Across children the rate, timing and severity of this loss is highly variable. Future research will lead to a greater understanding of the genetic and neurocognitive mechanisms that underlie these fundamental changes in the developmental patterns of individuals with ASD.

11. Yamasaki S, Yamasue H, Abe O, Suga M, Yamada H, Inoue H, Kuwabara H, Kawakubo Y, Yahata N, Aoki S, Kano Y, Kato N, Kasai K. {{Reduced Gray Matter Volume of Pars Opercularis Is Associated with Impaired Social Communication in High-Functioning Autism Spectrum Disorders}}. {Biol Psychiatry} (Aug 27)

BACKGROUND:: Recent literature suggests that the inferior frontal gyrus, especially its posterior portion, has an important role in imitation and social reciprocity and in the pathophysiology of their disturbance in autism spectrum disorders (ASD). However, the structural abnormality of this region has not fully been clarified in subjects with ASD. METHODS:: Here we obtained magnetic resonance images from 13 right-handed men with high-functioning ASD (Asperger disorder [n = 10] or autism [n = 3]) and from 11 age-, parental socioeconomic background-, and intelligence quotient-matched right-handed typical men. A reliable manual tracing methodology was employed to measure the gray matter volume of the pars opercularis, corresponding to Brodmann area 44, and the pars triangularis, corresponding to Brodmann area 45. RESULTS:: A significant gray matter volume reduction of both the pars opercularis and triangularis was found bilaterally in the subjects with ASD compared with the typical control subjects. The effect size seemed to be larger for pars opercularis (1.25) than for pars triangularis (.90). The reduced volume of right as well as total pars opercularis showed a significant association with the increased severity of social communication problems in the ASD group. CONCLUSIONS:: The current findings support an important role of pars opercularis, a center of the mirror neuron system, in the pathophysiology of ASD.