News Notes: Pediatric science roundup

A quick look at recent research Vector finds noteworthy.

Tracking infants’ microbiomes

cute microbes-shutterstock_317080235-croppedMicrobiome studies are blooming as rapidly as bacteria in an immunocompromised host. But few studies have been done in children, whose microbiomes are actively forming and vulnerable to outside influences. Two studies in Science Translational Medicine on June 15 tracked infants’ gut microbiomes prospectively over time. The first, led by researchers at the Broad Institute and Massachusetts General Hospital, analyzed DNA from monthly stool samples from 39 Finnish infants, starting at 2 months of age. Over the next three years, 20 of the children received at least one course of antibiotics. Those who were repeatedly dosed had fewer “good” bacteria, including microbes important in training the immune system. Overall, their microbiomes were less diverse and less stable, and their gut microbes had more antibiotic resistance genes, some of which lingered even after antibiotic treatment. Delivery mode (cesarean vs. vaginal) also affected microbial diversity. A second study at NYU Langone Medical Center tracked 43 U.S. infants for two years and similarly found disturbances in microbiome development associated with antibiotic treatment, delivery by cesarean section and formula feeding versus breastfeeding.

Urine proteomics could spare infants urologic testing

(Harald/Flickr)
(Harald/Flickr)

In up to 5 percent of infants, some degree of kidney dilation or swelling, known as hydronephrosis, is identified prenatally. This can be a sign of kidney obstruction requiring surgical correction, so after birth, many infants are subjected to invasive, costly diagnostic testing that exposes them to radiation and often has inconclusive results. Yet sometimes hydronephrosis resolves spontaneously. A study in Molecular & Cellular Proteomics, led by Boston Children’s urologist Richard Lee, MD, suggests the diagnostic promise of urine proteomics in detecting true kidney obstruction (known as ureteropelvic junction obstruction). Collaborating with the Proteomics Center, they systematically compared proteins in the urine of eight babies with an obstructed kidney versus eight healthy controls. Of 1,113 proteins identified, they found 76 whose amounts significantly differed in the babies with obstruction. Proteins involved in oxidative stress, inflammation and renal disease pathways were the most likely to be found in excess. From this initial “hit list,” Lee and colleagues hope to develop and clinically test a urine biomarker panel that could replace invasive testing.

Zebrafish EEG recordings

The electrode chamber used for EEG recordings (a), with nylon mesh and slice anchor to hold zebrafish larva in place (b) in the chamber with a drop of water (c). Once secured with the mesh (d), the microelectrode array (red dots) is positioned on the head (e).
The electrode chamber used for EEG recordings (a), with nylon mesh and slice anchor to hold zebrafish larva in place (b) in the chamber with a drop of water (c). Once secured with the mesh (d), the microelectrode array (red dots) is positioned on the head (e).

Zebrafish are valued in science for their ease of breeding and their convenience for large-scale drug testing — test chemicals need only be put in their water. Now scientists at the Epilepsy Genetics Program and F.M. Kirby Neurobiology Center at Boston Children’s Hospital have even developed a system to noninvasively measure their brain activity. In PLOS One on June 9, they describe a system for recording electrical activity from up to 61 different head locations in a live, developing zebrafish. From these EEGs in miniature, they could quantify neuronal firing frequency, spike patterns (continuous or bursting), and synchrony of neuronal firing (a hallmark of seizures). The recordings are allowing them to study the effects of seizures and observe how electrical activity changes in the presence of potential antiepileptic drugs—as in this study of PCDH19 epilepsy.