Evaluation of PET imaging as a tool for detecting neonatal hypoxic-ischemic encephalopathy in a preclinical animal model.

Hypoxic-ischemic encephalopathy due to insufficient oxygen delivery to brain tissue is a leading cause of death or severe morbidity in neonates. The early recognition of the most severely affected individuals remains a clinical challenge. We hypothesized that hypoxic-ischemic injury can be detected using PET radiotracers for hypoxia ([18F]EF5), glucose metabolism ([18F]FDG), and inflammation ([18F]F-DPA). METHODS: A preclinical model of neonatal hypoxic-ischemic brain injury was made in 9-d-old rat pups by permanent ligation of the left common carotid artery followed by hypoxia (8% oxygen and 92% nitrogen) for 120 min. In vivo PET imaging was performed immediately after injury induction or at different timepoints up to 21 d later. After imaging, ex vivo brain autoradiography was performed. Brain sections were stained with cresyl violet to evaluate the extent of the brain injury and to correlate it with [18F]FDG uptake. RESULTS: PET imaging revealed that all three of the radiotracers tested had significant uptake in the injured brain hemisphere. Ex vivo autoradiography revealed high [18F]EF5 uptake in the hypoxic hemisphere immediately after the injury (P < 0.0001), decreasing to baseline even 1 d postinjury. [18F]FDG uptake was highest in the injured hemisphere on the day of injury (P < 0.0001), whereas [18F]F-DPA uptake was evident after 4 d (P = 0.029), peaking 7 d postinjury (P < 0.0001), and remained significant 21 d after the injury. Targeted evaluation demonstrated that [18F]FDG uptake measured by in vivo imaging 1 d postinjury correlated positively with the brain volume loss detected 21 d later (r = 0.72, P = 0.028). CONCLUSION: Neonatal hypoxic-ischemic brain injury can be detected using PET imaging. Different types of radiotracers illustrate distinct phases of hypoxic brain damage. PET may be a new useful technique, worthy of being explored for clinical use, to predict and evaluate the course of the injury.

Associations of breastfeeding duration with serum lipid values from infancy until age 20 years - the STRIP study.

BACKGROUND AND AIMS: The effect of breastfeeding duration on childhood lipid levels has remained controversial. In this study, we aimed to establish the long-term associations of breastfeeding duration with future levels of total cholesterol, high-density lipoprotein (HDL) cholesterol, non-HDL cholesterol and low-density lipoprotein cholesterol. In addition, we report lipid levels at the age of seven months depending on the child receiving any breastmilk. METHODS: The sample comprised 999 children participating in the prospective Special Turku Coronary Risk Factor Intervention Project (STRIP). Serum lipid profile was studied at the ages of seven months and 13 months, and annually thereafter until the age of 20 years. Duration of breastfeeding was inquired, and infants were divided into those who received or did not receive any breast milk at the age of seven months (n=533 and n=466, respectively). In addition, breastfeeding duration groups (any breastfeeding for 0-4 months, 4-6 months, 6-9 months, and >9 months) were formed. RESULTS: At the age of seven months infants who at that time received breast milk had higher serum HDL cholesterol (0.95±0.21mmol/l vs. 0.90±0.19 mmol/l; p=0.0018), non-HDL cholesterol (3.38±0.78 mmol/l vs. 3.01±0.67 mmol/l; p<0.001) and total cholesterol levels (4.33±0.80 mmol/l vs. 3.91±0.69 mmol/l; p<0.001) than their peers who did not receive breast milk. From two to 20 years of age serum lipid levels showed no consistent differences between the breastfeeding duration groups. CONCLUSIONS: Our long-term data showed that duration of breastfeeding has no consistent associations with serum lipid concentrations in healthy individuals aged two to 20 years. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov, unique identifier NCT00223600.