The role of intrauterine bacteria in brain injury

Neonatal T-cell maturation and homing receptor responses to Toll-like receptor ligands differ from those of adult naive T cells: relationship to prematurity

INTRODUCTION

Inflammation and infection are associated with premature birth and with activation of the fetal immune system. We hypothesized that exposure to microbial Toll-like receptor (TLR) ligands plays an important role in neonatal T-cell maturation and that early exposure to microbial products may result in early T-cell maturation and a tendency for these matured effector cells to change their homing receptor patterns.

RESULTS

Expression of the CD45RO marker was induced in term neonatal T cells after in vitro exposure to TLR ligands for 7 days. Interestingly, naive T cells from adult blood were unaffected by TLR ligand exposure. In addition, neonatal T cells had more cells with decreased expression of the α4β7 integrins and increased expression of CCR4 after in vitro exposure of TLR ligands-similar to the expression of these molecules in adult naive T cells.

DISCUSSION

These findings are relevant for the understanding of neonatal T-cell maturation and may contribute to our understanding of multiorgan inflammatory complications of prematurity.

METHODS

Cord blood was obtained from term and preterm infants. Using flow cytometry, we identified a mature (CD45RO(+)) phenotype in preterm infant cord blood (CB) T cells that had decreased expression of the α4β7 integrins and increased expression of the C-C chemokine receptor 4 (CCR4) as compared with term infant CB.

Intrauterine penetrating direct fetal head trauma following gunshot injury: a case report and review of the literature

CASE REPORT

An unusual case of an intrauterine penetrating head injury due to a pellet from an airgun is described. A 28-year-old pregnant woman, at term, shot herself intravaginally with a toy BB gun. Following a spontaneous precipitous vaginal delivery, the neonate presented with persistent seizure disorder, meningitis, cerebritis, and a right parietal region scalp swelling. Imaging studies revealed intracranial hemorrhage, and the metallic pellet was adjacent to the right lateral ventricle, which was removed through a parietal craniotomy. Computed tomography of the brain after 1 week demonstrated early abscess formation in the left frontal operculum and a subdural empyema in the posterior fossa. The abscesses were evacuated, and the meningitis was treated vigorously with broad-spectrum antibiotics. Although well for the past 6 years, the child demonstrates significant mental handicap and developmental delay.

DISCUSSION

The pathogenesis, management, and medicolegal issues pertaining to the above case are discussed, and the relevant literature is briefly reviewed.