Neurodevelopmental effects of maternal nutritional status and exposure to methylmercury from eating fish during pregnancy

Fish contain nutrients that promote optimal brain growth and development but also contain methylmercury (MeHg) that can have toxic effects. The present study tested the hypothesis that the intake of selected nutrients in fish or measures of maternal nutritional status may represent important confounders when estimating the effects of prenatal methylmercury exposure on child development. The study took place in the Republic of Seychelles, an Indian Ocean archipelago where fish consumption is high. A longitudinal cohort study design was used. A total of 300 mothers were enrolled early in pregnancy. Nutrients considered to be important for brain development were measured during pregnancy along with prenatal MeHg exposure. The children were evaluated periodically to age 30 months. There were 229 children with complete outcome and covariate data for analysis. The primary endpoint was the Bayley Scales of Infant Development-II (BSID-II), administered at 9 and 30 months of age. Combinations of four secondary measures of infant cognition and memory were also given at 5, 9 and 25 months. Cohort mothers consumed an average of 537 g of fish (nine meals containing fish) per week. The average prenatal MeHg exposure was 5.9 ppm in maternal hair. The primary analysis examined the associations between MeHg, maternal nutritional measures and children's scores on the BSID-II and showed an adverse association between MeHg and the mean Psychomotor Developmental Index (PDI) score at 30 months. Secondary analyses of the association between the PDI and only MeHg alone or nutritional factors alone showed only a borderline significant association between MeHg and the PDI at 30 months and no associations with nutritional factors. One experimental measure at 5 months of age was positively associated with iodine status, but not prenatal MeHg exposure. These findings suggest a possible confounding role of maternal nutrition in studies examining associations between prenatal MeHg exposures and developmental outcomes in children.     

Nonverbal Communication Skills in Young Children with Autism

Objective The study was to examine nonverbal communication in young children with autism. Methods The participants were 23 young children with autism (mean CA = 32.79 months), 23 CA and MA-matched children with developmental delay and 22 18–20-month-old, and 22 13–15-month-old typically developing toddlers and infants. The abbreviated Early Social Communication Scales [Mundy et al. 1996, Early social communication scales (ESCS)] were used to test three types of nonverbal communicative skills, i.e., joint attention, requesting, and social interaction. Both frequency and proportion analyses were done in group comparisons. Results (1) Two- to three-year-old children with autism displayed deficits in joint attention ability, especially high-level skills. (2) The deficit in terms of frequency of communication was marked even compared with typically developing infants with younger mental age. (3) Young children with autism had different nonverbal communication profile compared with all three comparison groups. Conclusion Early social-communicative difficulties in autism involve early triadic communications involving joint attention and possibly dyadic turn-taking skills, which has implications for both early screening and early intervention.     

The Autism Spectrum Quotient: Children’s Version (AQ-Child)

The Autism Spectrum Quotient-Children's Version (AQ-Child) is a parent-report questionnaire that aims to quantify autistic traits in children 4-11 years old. The range of scores on the AQ-Child is 0-150. It was administered to children with an autism spectrum condition (ASC) (n = 540) and a general population sample (n = 1,225). Results showed a significant difference in scores between those with an ASC diagnosis and the general population. Receiver-operating-characteristic analyses showed that using a cut-off score of 76, the AQ-Child has high sensitivity (95%) and specificity (95%). The AQ-Child showed good test-retest reliability and high internal consistency. Factor analysis provided support for four of the five AQ-Child design subscales. Future studies should evaluate how the AQ-C performs in population screening.     

Friendship in High-functioning Children with Autism Spectrum Disorder: Mixed and Non-mixed Dyads

Friendships containing a child with autism and a friend with typical development ("mixed" friendships, n = 26) and those of children with autism and a friend with a disability ("non-mixed," n = 16) were contrasted with friendships of typically developing subjects and their friends (n = 31). Measures included dyadic interaction samples, and interview and questionnaire data from subjects, friends, and parents. Mixed friendship interactions resembled typical friendships. Participants in mixed friendships were more responsive to one another, had stronger receptive language skills, exhibited greater positive social orientation and cohesion, and demonstrated more complex coordinated play than in the non-mixed dyads. Exposure to typical peers appears to have significant effects on friendship behaviors.     

The Early Development of Joint Attention in Infants with Autistic Disorder Using Home Video Observations and Parental Interview

The aim in the current study was to investigate the early development of joint attention, eye contact and affect during the first 2 years of life, by using retrospective parental interviews and analyses of home videos of infants who were later diagnosed with Autistic Disorder (AD). The 36 children with AD and the 27 matched control children were all aged between 3 and 5 years at recruitment. Reported anomalies in gaze and affect emerged in the children with AD as early as the first 6 months of life, generally becoming more severe just prior to the second birthday. Video data confirmed these anomalies from as early as the first year. Joint attention impairments were found throughout the second year of life. The results suggest that early dyadic behaviours—eye contact and affect—may play a role in the joint attention impairment in AD.

Narrative Discourse in Adults with High-Functioning Autism or Asperger Syndrome

We report a study comparing the narrative abilities of 12 adults with high-functioning autism (HFA) or Asperger Syndrome (AS) versus 12 matched controls. The study focuses on the use of referential expressions (temporal expressions and anaphoric pronouns) during a story-telling task. The aim was to assess pragmatics skills in people with HFA/AS in whom linguistic impairments are more subtle than in classic autism. We predicted no significant differences in general narrative abilities between the two groups, but specific pragmatic deficits in people with AS. We predicted they use fewer personal pronouns, temporal expressions and referential expressions, which require theory of mind abilities. Results confirmed both predictions. These findings provide initial evidence of how social impairments can produce mild linguistic impairments.     

Long-range correlation of renal sympathetic nerve activity in both conscious and anesthetized rats

In this study we employed both detrended fluctuation analysis (DFA) and multiscale entropy (MSE) measurements to compare the long-range temporal correlation (LRTC) of multifibre renal sympathetic nerve activity (RSNA) between conscious and anesthetized Wistar rats. It was found that both methods showed the obvious LRTC properties in conscious state. Moreover, the scaling exponent of the RSNA in conscious rats was significantly higher than that in anesthetized rats. The results of MSE analysis showed that the entropy values, derived from the conscious group, increased on small time scales and then stabilized to a relatively constant value whereas the entropy measure, derived from anesthetized animals, almost monotonically decreased. This suggests that the fractal properties of underlying dynamics of the system have been reduced by anesthesia. The results demonstrate that apparently random fluctuations in multifibre RSNA are dictated by a complex deterministic process that imparts "long-term" memory to the dynamic system. However, this memory is significantly weakened by anesthesia.