title: In vitro production of bilirubin photoisomers by light irradiation using neoBLUE.
abstract: BACKGROUND
  The light-emitting diode is used as one of the new light sources for phototherapy. NeoBLUE (Atom Medical, Tokyo, Japan) incorporates blue light-emitting diodes for the treatment of neonatal hyperbilirubinemia. The authors compared the in vitro efficacy of neoBLUE with conventional phototherapy devices.
  
  
  METHODS
  The three light devices used included neoBLUE and two conventional phototherapy devices with six blue-white (BW) or six green (GR) fluorescent tubes. A bilirubin/human serum albumin solution (15 mg/dL) in 200 x 300 mm elliptical bag was irradiated with each three light device. The average light intensity of neoBLUE, BW and GR was 22.5, 10.2 and 2.6 microW/cm(2) per nm, respectively, for the irradiated area. Bilirubin photoisomers and native bilirubin were measured by high-performance liquid chromatography.
  
  
  RESULTS
  In neoBLUE, BW and GR, the respective production rate of cyclobilirubin was 6.0, 3.7 and 3.9 x 10(-2) mg/dL/min, and the respective (4Z, 15E)-bilirubin/(4Z, 15Z)-bilirubin ratio after irradiation was 0.44, 0.33 and 0.12; the (4Z, 15Z)-bilirubin reduction rate at 20 min after irradiation was 60, 68 and 82%, respectively. The reduction rate of (4Z, 15Z)-bilirubin correlated with the (4Z, 15E)-bilirubin/(4Z, 15Z)-bilirubin ratio.
  
  
  CONCLUSIONS
  Phototherapy using the neoBLUE under high level may be clinically more effective than therapy using the conventional light source from the results of the production rate of cyclobilirubin.
authors.affiliation: Department of Pediatrics, Kangawa University, Kangawa, Japan. syounika@med.kagawa-u.ac.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okada
authors.forename: Tae
authors.initials: T
authors.lastname: Abe
authors.forename: Yoko
authors.initials: Y
authors.lastname: Etoh
authors.forename: Shuji
authors.initials: S
authors.lastname: Yoshino
authors.forename: Ikuko
authors.initials: I
authors.lastname: Kato
authors.forename: Takuma
authors.initials: T
authors.lastname: Iwaki
authors.forename: Kensuke
authors.initials: K
authors.lastname: Okubo
authors.forename: Saneyuki
authors.initials: S
authors.lastname: Yasuda
authors.forename: Kou
authors.initials: K
authors.lastname: Kawada
authors.forename: Takashi
authors.initials: T
authors.lastname: Kusaka
authors.forename: Masanori
authors.initials: M
authors.lastname: Namba
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nishida
authors.forename: Tadashi
authors.initials: T
authors.lastname: Imai
authors.forename: Kenichi
authors.initials: K
authors.lastname: Isobe
authors.forename: Susumu
authors.initials: S
authors.lastname: Itoh
mesh_terms: D001663:Bilirubin / Q000031:analogs & derivatives / Q000096:biosynthesis* / Q000528:radiation effects; D002851:Chromatography, High Pressure Liquid; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D006932:Hyperbilirubinemia / Q000097:blood / Q000628:therapy; D007231:Infant, Newborn; D007536:Isomerism; D008027:Light; D010789:Phototherapy / Q000379:methods*
chemical_list: C041079:cyclobilirubin; D001663:Bilirubin