Collaborative Research Group for Necrotizing Enterocolitis

Not Applicable

Completed

Interventions: Biological: [5,5,5-2H3]leucine (stable isotope labeled leucine)

Brief Summary: This proposal will test the hypothesis that synthesis and catabolism of epidermal growth factor (EGF), the genotype of the EGF gene, and the microbiome interact to influence EGF expression in infants at risk for necrotizing enterocolitis (NEC).

Detailed Description: * 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.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Arm && Interventions

Group	Intervention	Description
Preterm Infants for EGF Profiles	[5,5,5-2H3]leucine (stable isotope labeled leucine)	Premature infants born at \< 32 weeks gestation who are 7 days old or less. Infants received and intravenous infusion of \[5,5,5-2H3\]leucine (stable isotope labeled leucine) with sampling of blood, urine and saliva.

Primary Outcome Measures

Name	Time	Method
Salivary EGF (Epidermal Growth Factor) Protein Levels	Sampling occurred on average day of life 9 with a range from day of life 7 to 21	Salivary EGF protein levels obtained from oral swabs were analyzed by commercially available EGF ELISA kit (R \&D systems Inc). EGF protein levels were normalized to micrograms of protein in saliva, and expressed as picogram of EGF protein per microgram of total salivary protein.
Urinary EGF Protein Levels	Sampling occurred on average day of life 9 with a range from day of life 7 to 21	Urinary EGF protein levels obtained from free flowing urine samples retrieved from subject diaper were analyzed by commercially available EGF ELISA kit (R \&D systems Inc). EGF protein levels were normalized to milligrams of creatinine in urine, and expressed as nanograms of EGF protein per milligram of urinary creatinine.

Secondary Outcome Measures

Name	Time	Method
EGF Gene Sequencing	Sampling occurred on average day of life 9 with a range from day of life 7 to 21	Identification of computationally predicted functional variants in EGF gene