Collaborative Research Group for Necrotizing Enterocolitis

• Preterm infants will receive a six hour intravenous infusion of [5,5,5-2H3]leucine (2H3) through an existing intravenous line (IV) to measure EGF synthesis rate.
• Two blood samples will be obtained, one prior to the start of infusion, and one during the infusion. The enrichment of the stable isotope labeled leucine will be measured in the plasma from these samples; DNA will be extracted from the residual cell pellets. The EGF and EGF receptor genes will be sequenced.
• Saliva and urine will be obtained for 5 days following infusion to measure EGF and the rate of incorporation of leucine into EGF using liquid chromatography (LC)/mass spectroscopy (MS)/MS technology, as well as enzyme-linked immunosorbent assay (ELISA) . Saliva will be obtained by a Q tip swab and urine and stool obtained from the diaper.
• Stool will be obtained every 3 to 7 days through 5 weeks to evaluate inflammatory markers and the microbiome.
• If breastfeeding, a single sample of mother's milk will be obtained for measurement of EGF after adequate volumes for infant feeds are achieved.

Inclusion criteria

• gestation 32 weeks or less
• 1 week of age or less
• intravenous line in place for clinical purposes

Exclusion criteria

• imminent death
• active infection
• pre-existing diagnosis of NEC
• fluid or electrolyte imbalance