ARIAS, IRWIN M., LOIS JOHNSON, AND SONIA WOLFSON. Biliary excretion of injected conjugated and unconjugated bilirubin by normal and Gunn rats. Am. J. Physiol. 200(5) : I 091-1094. I 961. -Conjugated and unconjugated bilirubin were injected intravenously at different times into normal rats and homozygous, jaundiced Gunn rats. As was expected, Gunn rats did not excrete injected unconjugated bilir...

Hepatic biotransformation of bilirubin to the hydrophilic species bilirubin mono- (BMG) and diglucuronide (BDG) by microsomal bilirubin UDP-glucuronosyl-transferase (GT) is a prerequisite for its physiologic excretion into bile. The reaction mechanism of bilirubin-GT and the access of bilirubin and BMG (the intermediate substrate) to the active site of bilirubin-GT are undefined. Highly purifie...

OBJECTIVE To compare transcutaneous bilirubin with total serum bilirubin in preterm neonates after initiation of phototherapy. METHODS Jaundice was assessed in 30 preterm neonates with transcutaneous bilirubin and total serum bilirubin before initiation of phototherapy and at 12 hr after initiation of phototherapy. A photo-occlusive patch was applied over the sternum. RESULTS Transcutaneous...

Neonatal jaundice can be best understood as a balance between the production and elimination of bilirubin, with a multitude of factors and conditions affecting each of these processes. When an imbalance results because of an increase in circulating bilirubin (or the bilirubin load) to significantly high levels (severe hyperbilirubinemia), it may cause permanent neurologic sequelae (kernicterus)...

Increased serum levels of unconjugated bilirubin are associated with the development of brain damage in newborns. In current clinical settings, there are no methods for directly determining serum levels of unconjugated bilirubin. UnaG, a fluorescent protein from Japanese eel muscle that specifically binds to unconjugated bilirubin was used in this study. Linear regression analysis was carried o...

It has been stated by McDonagh, Palma & Lightner [(1982) J. Am. Chem. Soc. 104, 6867-6871] that complexing of bilirubin with serum albumin has a marked species-dependent influence on bilirubin photoisomerization in vitro and in vivo. Therefore the kinetics for the quantitatively important reaction: (Formula: see text) of the photochemical interconversion between bilirubin and its photoisomers b...

We compared data obtained with the Kodak Ektachem and Hitachi 717 Analysers and HPLC from 83 neonates under phototherapy. Total bilirubin values determined with the Kodak and Hitachi are in good agreement, but we observed a large discrepancy in the results for conjugated (Kodak) and direct (Hitachi) bilirubin. HPLC revealed that all the samples contained configurational isomers, while only 7.7%...

The accuracy of transcutaneous bilirubin meters has been assessed in newborns from various ethnic backgrounds. However, there are limited data on Greek newborns. Our study examined the accuracy of transcutaneous bilirubin measurements in clinically jaundiced healthy-term Greek newborns, using total serum bilirubin as the reference standard, in order to re-evaluate our local guidelines about neo...

An enzymatic assay is described for non-albuminbound bilirubin in the serum of newborn infants. Unbound bilirubin is oxidized to colorless compounds by ethyl hydroperoxide in the presence of horseradish peroxidase (EC 1.11.1.7), while albumin-bound bilirubin is protected from oxidation. Because the equilibrium between albumin and bilirubin occurs rapidly, the oxidation step is rate limiting, an...