Evidence for altered central noradrenergic function in experimental acute liver failure in the rat

These is increasing evidence to suggest that central noradrenergic mechanisms may contribute to the central nervous system manifestations of acute liver failure. To further elucidate this possibility, extracellular brain concentrations of the monoamines, noradrenaline (NA), dopamine (DA), and serotonin, were measured by high-performance liquid chromatography with electrochemical detection in microdialysates from the extracellular compartment of frontal cortex in rats with acute (ischemic) liver failure at various times during the progression of encephalopathy and brain edema, as well as in obligate control groups of animals. In addition, binding sites for the noradrenergic receptor subtype ligands, [3H]-prazosin (alpha1 sites), [3H]-RX821002 (alpha2 sites), and [125]I-iodopindolol (beta sites), were assessed using quantitative receptor autoradiography in regions of the brains of rats at coma stage of acute liver failure and of control groups of animals. Coma stages of encephalopathy in acute liver failure were associated with selectively increased noradrenaline concentrations (P < .05) and a concomitant selective loss of alpha1 and beta1 sites in frontal cortex and thalamus. These findings add to a growing body of evidence that central noradrenergic function is modified in acute liver failure and suggest that alpha1/beta1 receptor-mediated noradrenergic mechanisms may play a role in the pathogenesis of brain edema and encephalopathy in this condition.

Excess of congenital abnormalities in French-Canadian children with neuroblastoma: a case series study from Montréal

Neuroblastoma is one of the most common cancers of childhood. Some studies have shown an excess of congenital abnormalities in children who have been diagnosed with neuroblastoma. In this study we examined the medical records of all children with neuroblastoma seen at St. Justine Children's Hospital between the years 1977 and 1993. A total of 141 children (131 of French-Canadian ancestry) were included in this study. Twelve children (8.5%) had 21 defined congenital abnormalities (1,490 per 10,000 children). This compared with a rate of 444.3 children with abnormalities per 10,000 live births (4.44%) for all congenital abnormalities in the British Columbia Health Surveillance Registry, 1979-1988 (relative risk = 1.91, P = 0.03). Six of the 12 children had cardiovascular malformations. These and previous results suggest that there may be a common developmental origin to neuroblastoma and to some congenital malformations. Genes that control development may be worthy of further study in these children.