Temporal expression of ACE2 during development

Song and colleagues examined the temporal expression of angiotensin-converting enzyme 2 (ACE2) during renal, heart, lung, and brain organogenesis in the mouse. They demonstrated that kidney ACE2 mRNA levels are low on embryonic day 12.5, increase fourfold during development, and decline in adulthood. The investigators postulate that relatively high ACE2 protein levels and enzymatic activity observed during gestation may play a role in kidney, lung, brain, and heart organogenesis.

See Ontogeny of angiotensin-converting enzyme 2

iNOS-derived NO in hypoxic fetal hearts

Evans et al. tested the hypothesis that maternal hypoxia increases fetal cardiac matrix metalloproteinase 9 and collagen via peroxynitrite generation in fetal hearts. Maternal hypoxia induced oxidative/nitrosative stress and altered protein expression of the extracellular matrix via upregulation of the inducible nitric oxide synthase (iNOS) pathway in fetal heart ventricles. The authors conclude that iNOS-derived NO might be an important stimulus for the adverse effects of peroxynitrite in hypoxic fetal hearts.

See Chronic hypoxia increases peroxynitrite, MMP9 expression, and collagen accumulation in fetal guinea pig hearts

Immunomodulatory effects of probiotics during early infancy

To examine the immunomodulatory effects of probiotics during early infancy, Ohtsuka et al. administered Bifidobacterium breve M-16V to rat pups during the newborn or weaning period. The investigators looked at the expression of inflammatory genes using cDNA microarray and real-time PCR. Their findings support a possible role for B. breve in mediating anti-inflammatory and antiallergic reactions by modulating the expression of inflammatory molecules during the newborn period and by regulating the expression of costimulatory molecules during the weaning period.

See Effects of Bifidobacterium breve on inflammatory gene expression in neonatal and weaning rat intestine

Apoptotic potential of propylene glycol in developing CNS

Propylene glycol (PG) is a solvent commonly used in medical preparations. It is generally considered safe at regulated concentrations. To explore its apoptotic potential in the developing central nervous system, Lau and co-workers exposed C57BL/6 mice (P4-30) to PG shortly after birth. They also assessed whether PG contributes to the neurotoxic potential of phenobarbital. The agents produced significantly more apoptosis when used in combination, suggesting that finding an alternative nonapoptotic solvent might be beneficial to patients.

See Propylene glycol produces excessive apoptosis in the developing mouse brain, alone and in combination with phenobarbital

LBW piglet model of cognitive impairment

Similarities between human and piglet newborns with regard to low birth weight (LBW) and development make LBW piglets a potential naturally occurring model of cognitive impairment in LBW humans. To examine this potential model, the investigators tested pairs of LBW and normal-birth-weight piglets on a spatial hole-board task. The results suggest that LBW is associated with mild cognitive impairments.

See Cognitive performance of low- and normal-birth-weight piglets in a spatial hole-board discrimination task

Whole body cooling and neuroprotection

Corbo et al. retrospectively compared medical and neuroimaging data for 19 newborns who received 72 hours of whole-body cooling with those for 19 noncooled newborns to determine whether hypothermia was associated with improved injury severity as measured by magnetic resonance imaging (MRI) and magnetic resonance spectroscopy within the first 14 days of life. Hypothermia therapy was associated with a decrease in detectable cortical and subcortical lactate as well as in subcortical lesions on MRI.

See The effect of whole-body cooling on brain metabolism following perinatal hypoxic-ischemic injury