High frequency oscillation and exogenous surfactant in the treatment of neonatal respiratory distress syndrome

Surfactant therapy has become widely used in neonates suffering from respiratory distress syndrome. High frequency oscillation has been shown to be efficient and safe in animal models, but somewhat less convincing in human neonates. An overview is given of the experimental and clinical data assessing the combination of these two techniques. Personal preliminary data are briefly presented.     

A prospective analysis of cholestasis in infants supported with extracorporeal membrane oxygenation.

Cholestasis develops in many infants supported with extracorporeal membrane oxygenation. We prospectively investigated the role of hemolysis and di-(2-ethylhexyl) phthalate exposure in the development of this cholestasis. Both di-(2-ethylhexyl) phthalate levels and hemolysis, as measured by maximum free hemoglobin, were significantly (p less than 0.025) associated with the degree of cholestasis. Other clinical and laboratory factors that may contribute to cholestasis were also investigated and not found to be related to the degree of cholestasis. We speculate that hemolysis during extracorporeal membrane oxygenation support produces a large bilirubin load whose excretion is inhibited by mechanisms similar to the inspissated bile syndrome and/or by di-(2-ethylhexyl) phthalate. This would result in a predominantly direct hyperbilirubinemia with little evidence of hepatocellular or canalicular injury.     

Identification, chromosomal mapping and tissue-specific expression of hREV3 encoding a putative human DNA polymerase zeta

The Saccharomyces cerevisiae REV3 gene encodes the catalytic subunit of a non-essential DNA polymerase zeta, which is required for mutagenesis. The rev3 mutants significantly reduce both spontaneous and DNA damage- induced mutation rates. We have identified human cDNA clones from two different libraries whose deduced amino acid sequences bear remarkable homology to the yeast Rev3, and named this gene hREV3. The hREV3 gene was mapped to chromosome 1p32-33 by fluorescence in situ hybridization. The hREV3 encodes an mRNA of >10 kb, and its expression varies in different tissues and appears to be elevated in some but not all of the tumor cell lines we have examined. In light of recent reports of a putative mouse REV3, these results indicate that mammalian cells may also contain a mutagenic pathway which aids in cell survival at the cost of increased mutation.