Influence of photoisomers in bilirubin determinations on Kodak Ektachem and Hitachi analysers in neonatal specimens study of the contribution of structural and configurational isomers
| Autor: | Gulian Jm, Daniel Unal, Christiane Dalmasso, Véronique Millet, Michel Charrel |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Delta Bilirubin
Light Stereochemistry Bilirubin education Clinical Biochemistry Stereoisomerism High-performance liquid chromatography chemistry.chemical_compound Isomerism Spectrophotometry medicine Structural isomer Humans Chromatography High Pressure Liquid Chromatography medicine.diagnostic_test Molecular Structure Chemistry Biochemistry (medical) Infant Newborn General Medicine Phototherapy Jaundice Neonatal Kinetics Positive response Regression Analysis Isomerization |
| Zdroj: | European journal of clinical chemistry and clinical biochemistry : journal of the Forum of European Clinical Chemistry Societies. 33(8) |
| ISSN: | 0939-4974 |
| Popis: | 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% and 30.8% contained conjugated bilirubin and structural isomers, respectively. We developed a device for the specific and quantitative production of configurational or structural isomers, by irradiation with blue or green light. In vitro, total bilirubin values are coherent for the routine analysers in the presence of configurational or structural isomers. With configurational isomers, unconjugated bilirubin (Kodak) is lower than total bilirubin (Kodak), and conjugated bilirubin (Kodak) is always equal to zero, so the apparatus gives a false positive response for delta bilirubin. In contrast, the direct bilirubin (Hitachi) is constant. Furthermore, in the presence of structural isomers, unconjugated bilirubin (Kodak) is unexpectedly higher than total bilirubin (Kodak), conjugated bilirubin (Kodak) is proportional to the quantity of these isomers, and direct bilirubin (Hitachi) is constant. The contribution of photoisomers in bilirubin measurements is discussed. |
| Databáze: | OpenAIRE |
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