Amniotic fluid levels of phospholipase A2 in fetal rats with retinoic acid induced myelomeningocele: the potential "second hit" in neurologic damage.

OBJECTIVES: There is growing evidence of ongoing, in utero neurological damage in fetuses with myelomeningocele (MMC). Phospholipase A2 (PLA2) has known neurotoxic properties and is predominantly present in its secretory isoform (sPLA2) in meconium, the passage of which is increased in MMC fetuses. The objective of this study was to determine if amniotic fluid (AF) levels of PLA2 are elevated in a rat model of MMC. METHODS: Timed pregnant Sprague-Dawley rats were gavage fed 60 mg/kg/bodyweight retinoic acid (RA) in olive oil at embryonic day 10 (E10). Amniocentesis was performed at multiple gestational time points on MMC fetuses, RA-exposed fetuses without MMC and control fetuses. AF PLA2 levels were analyzed by a fluorescent enzyme activity assay. PLA2 isoforms were determined by measuring activity in the presence of specific inhibitors. RESULTS: There was no difference in AF PLA2 activity between groups on E15. PLA2 activity was significantly increased in MMC fetuses on E17, E19 and E21 (p < 0.001). Secretory PLA2 primarily accounted for the overall greater activity. CONCLUSIONS: PLA2 levels are elevated in the AF of fetal rats with MMC and may contribute to ongoing neural injury. This pathway may be a useful drug target to limit ongoing damage and better preserve neurologic function.

Do children with autism who pass false belief tasks understand the mind as active interpreter?

Interpretive diversity is the term used by Carpendale and Chandler (1996) to refer to the fact that two individuals exposed to precisely the same stimulus may interpret it in quite different, but equally plausible, ways. An appreciation of interpretive diversity is said by Carpendale and Chandler to represent a development in understanding that is qualitatively different from that necessary to succeed on false belief tasks. A study is reported in which children with autism and children with general delay were given a battery of tasks consisting of false belief tasks and tasks designed to test for an understanding of interpretive diversity. Findings from the present study offer limited support for Carpendale and Chandler's claim that tasks which test for an understanding of interpretive diversity may be more difficult than false belief tasks. Between-group differences in the consistency and quality of responses given by participants suggest that autistic and delayed children may have differed somewhat in their approach to the tasks given.