Effect of maternal antibiotic treatment on fetal periventricular white matter cell death in a rabbit intrauterine infection model

Molecular mechanisms involved in injury to the preterm brain

Injury to the premature brain is a major contributor to infant mortality and morbidity, often leading to mental retardation and sensory-motor impairment. The disease process is believed to be caused, sustained, and aggravated by multiple perinatal factors that team up in a multi-hit fashion. Clinical, epidemiological, and experimental studies have revealed that key factors such as inflammation, excitotoxicity, and oxidative stress contribute considerably to white- and gray-matter injury in premature infants, whose brains are particularly susceptible to damage. Depending on the timing, lesions of the immature brain may influence developmental events in their natural sequence and redirect subsequent development. We review current concepts on molecular mechanisms underlying injury to the premature brain.

Inflammatory brain damage in preterm newborns--dry numbers, wet lab, and causal inferences

Epidemiologic observations support the contention that infection, inflammation, and neonatal white matter damage (WMD) are associated. We also have documentation from multiple experimental models that infection/inflammation can damage developing white matter. Based on these observations in humans and animals, we offer causal inferences using widely accepted causal criteria and the multivariable model of causation. As much as we want to, however, we are reluctant to state unequivocally that inflammation causes WMD in humans born much before term. The main reason is that we lack convincing evidence that inflammation precedes WMD (temporal evidence). We also need more (and more detailed) observational studies clarifying the presumed infection --> inflammation --> WMD sequence before we can initiate intervention trials to reduce the risk of WMD.

Animal models of hypoxic-ischemic brain damage in the newborn

Controversy continues over which animal model to use as a reflection of human disease states. With respect to perinatal brain disorders, scientists must contend with a disease in evolution. In that regard, the perinatal brain is at risk during a time of extremely rapid development and maturation, involving processes that are required for normal growth. Interfering with these processes, as part of therapeutic intervention must be efficacious and safe. To date, numerous models have provided tremendous information regarding the pathophysiology of brain damage to term and preterm infants. Our challenges will continue to be in identifying those infants at greatest risk for permanent injury, and adapting therapies that provide more benefit than harm. Using animal models to conduct these studies will bring us closer to that goal.