Prenatal ultrasound and childhood autism: long-term follow-up after a randomized controlled trial of first-vs-second-trimester ultrasound

Objective: To analyze whether the frequency of autism spectrum disorder (ASD) in a cohort of Swedish children differs between those exposed to ultrasound in the 12th week and those exposed to ultrasound in the 18th week of gestation. Methods: The study cohort consisted of approximately 30 000 children born between 1999 and 2003 to mothers who had been randomized to a prenatal ultrasound examination at either 12 or 18 weeks' gestation as part of the framework for a study on nuchal translucency screening. The outcome measure in the present study was the rate of ASD diagnoses among the children. Information on ASD diagnoses was based on data from the Swedish social insurance agency concerning childcare allowance granted for ASD. Results: Between 1999 and 2003, a total of 14 726 children were born to women who underwent a 12‐week ultrasound examination and 14 596 to women who underwent an 18‐week ultrasound examination. Of these, 181 (1.2%) and 176 (1.2%) children, respectively, had been diagnosed with ASD. There was no difference in ASD frequency between the early and late ultrasound groups. Conclusions: Women subjected to at least one prenatal ultrasound examination at either 12 or 18 weeks' gestation had children with similar rates of ASD. However, this result reflects routine care 10–15 years ago in Sweden. Today, higher intensity ultrasound scans are performed more frequently, at earlier stages during pregnancy and for non‐medical purposes, implying longer exposure time for the fetus. This change in the use of ultrasound necessitates further follow‐up study of the possible effects that high exposure to ultrasound during the gestational period has on the developing brain

The tobacco homolog of mammalian calreticulin is present in protein complexes in vivo.

The analysis of protein sorting signals responsible for the retention of reticuloplasmins (RPLs), a group of soluble proteins that reside in the lumen of the endoplasmic reticulum (ER), has revealed a structural similarity between mammalian and plant ER retention signals. We present evidence that the corresponding epitope is conserved in a vast family of soluble ER resident proteins. Microsequences of RPL60 and RPL90, two abundant members of this family, show high sequence similarity with mammalian calreticulin and endoplasmin. RPL60/calreticulin cofractionates and costains with the lumenal binding protein (BiP). Both proteins were detected in the nuclear envelope and the ER, and in mitotic cells in association with the spindle apparatus and the phragmoplast. Immunoprecipitation of proteins from in vivo-labeled cells demonstrated that RPL60/calreticulin is associated with other polypeptides in a stress- and ATP-dependent fashion. RPL60/calreticulin transcript levels increased rapidly in abundance during the proliferation of the secretory apparatus and the onset of hydrolase secretion in gibberellic acid-treated barley aleurone cells. This induction profile is identical to that of the well-characterized ER chaperones BiP and endoplasmin. However, expression patterns in response to different stress conditions as well as tissue-specific expression patterns indicate that these genes are differentially regulated and may not act in concert