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Takashi Kusaka - One of the best experts on this subject based on the ideXlab platform.
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Bilirubin photoisomers in rhesus monkey serum
Journal of photochemistry and photobiology. B Biology, 2018Co-Authors: Hitoshi Okada, Susumu Itoh, Kohichiroh Nii, Masashiro Sugino, Noriko Fuke, Kosuke Koyano, Saneyuki Yasuda, Takashi KusakaAbstract:Abstract As rhesus monkeys exhibit physiological jaundice during the neonatal period, we used rhesus monkey serum to examine changes in Bilirubin photoisomers. Bilirubin-rhesus monkey serum solution was irradiated with blue light-emitting diode, and changes in the absorbance and Bilirubin fraction were compared with those in Bilirubin- human serum albumin (HSA) and Bilirubin-rat albumin solutions. The λmax decreased with light irradiation. The mean production rate of cycloBilirubin IXα was 1.98, 199 and 0.76 × 10−2/min in rhesus monkey serum, HSA and rat albumin, respectively. There was no significant difference between rhesus monkey serum and HSA. The (ZE)-Bilirubin IXα/(ZZ)-Bilirubin IXα ratio was 0.33, 0.45, and 0.10, respectively, differing significantly among the groups. The (EZ)-Bilirubin IXα/(ZZ)-Bilirubin IXα ratio was 0.020, 0.010, and 0.062, respectively, with no significant difference between rhesus monkey serum and HSA. The production rate of (EZ)-cycloBilirubin XIIIα(= (ZE)-cycloBilirubin XIIIα) was 0.73, 1.60, and 0.51 × 10−2/min, respectively, with differing significantly among the groups. The (EZ)-Bilirubin IIIα/(ZZ)-Bilirubin IIIα ratio was significantly different among the groups at 0.20, 0.38, and 0.15, respectively. This is the first report demonstrating the photoisomerization of Bilirubin in rhesus monkey serum and the animal with the same cycloBilirubin production rate as HSA.Rhesus monkeys may be used as an animal model for neonatal hyperBilirubinemia in humans to evaluate the efficacy of phototherapy.
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Reactivity of Bilirubin photoisomers on the measurement of direct Bilirubin using vanadic acid method
Annals of clinical biochemistry, 2017Co-Authors: Hitoshi Okada, Susumu Itoh, Shohei Kawamoto, Miyo Ozaki, Takashi KusakaAbstract:Objective Investigation of the reactivity of fractions of Bilirubin photoisomers with the vanadic acid oxidation method. Methods Bilirubin photoisomers were prepared by irradiating a Bilirubin/human serum albumin solution with blue light emitting diode. Direct Bilirubin and Bilirubin fractions were measured using the vanadic acid oxidation method and high-performance liquid chromatography in the sample before and after irradiation. Results Direct Bilirubin was increased in the solution containing Bilirubin photoisomers. ( EE)-/( EZ) -cycloBilirubin-IXα and ( ZE)-/( EZ)-Bilirubin-IXα completely disappeared after the addition of vanadic acid. Conclusion Bilirubin photoisomers reacted as direct Bilirubin in the vanadic acid oxidation method.
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Influence of Bilirubin photoisomers on unbound Bilirubin measurement in clinical settings.
Annals of clinical biochemistry, 2012Co-Authors: Hitoshi Okada, Kosuke Koyano, Saneyuki Yasuda, Takashi Kusaka, Kaori Koyano, Jun Kunikata, Takashi Iwase, Kenichi Isobe, Susumu ItohAbstract:Measured unbound Bilirubin concentration is influenced by Bilirubin photoisomers. Bilirubin photoisomers are produced even with only a slight light exposure, and clinical samples are inevitably exposed to light. The objective of the study was to evaluate the influence of Bilirubin photoisomers on the measurement of unbound Bilirubin using serum of jaundiced neonates during blue light phototherapy. Five neonates treated with phototherapy for hyperBilirubinaemia were enrolled. The samples were taken 12 h after initiation of phototherapy. Samples were processed by irradiation with blue light, by indoor ceiling light, by both blue light and indoor ceiling light or shaded. Bilirubin subfractions, total Bilirubin and unbound Bilirubin were measured. Compared with the non-irradiated samples, the (EZ)-cycloBilirubin concentration and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the blue light-irradiated samples, the (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the indoor ceiling light-irradiated samples, and the (EZ)-cycloBilirubin, (EZ)-Bilirubin and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the samples irradiated with both lights. No change was noted in unbound Bilirubin in any group. We consider that changes in Bilirubin photoisomers induced by light exposure during clinical practice do not influence the measured unbound Bilirubin concentration.
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Influence of Bilirubin photoisomers on unbound Bilirubin measurement in clinical settings
Annals of Clinical Biochemistry: International Journal of Laboratory Medicine, 2012Co-Authors: Hitoshi Okada, Kosuke Koyano, Saneyuki Yasuda, Takashi Kusaka, Kaori Koyano, Jun Kunikata, Takashi Iwase, Kenichi Isobe, Susumu ItohAbstract:BackgroundMeasured unbound Bilirubin concentration is influenced by Bilirubin photoisomers. Bilirubin photoisomers are produced even with only a slight light exposure, and clinical samples are inevitably exposed to light. The objective of the study was to evaluate the influence of Bilirubin photoisomers on the measurement of unbound Bilirubin using serum of jaundiced neonates during blue light phototherapy.MethodsFive neonates treated with phototherapy for hyperBilirubinaemia were enrolled. The samples were taken 12 h after initiation of phototherapy. Samples were processed by irradiation with blue light, by indoor ceiling light, by both blue light and indoor ceiling light or shaded. Bilirubin subfractions, total Bilirubin and unbound Bilirubin were measured.ResultsCompared with the non-irradiated samples, the (EZ)-cycloBilirubin concentration and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the blue light-irradiated samples, the (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increase...
Hitoshi Okada - One of the best experts on this subject based on the ideXlab platform.
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Bilirubin photoisomers in rhesus monkey serum
Journal of photochemistry and photobiology. B Biology, 2018Co-Authors: Hitoshi Okada, Susumu Itoh, Kohichiroh Nii, Masashiro Sugino, Noriko Fuke, Kosuke Koyano, Saneyuki Yasuda, Takashi KusakaAbstract:Abstract As rhesus monkeys exhibit physiological jaundice during the neonatal period, we used rhesus monkey serum to examine changes in Bilirubin photoisomers. Bilirubin-rhesus monkey serum solution was irradiated with blue light-emitting diode, and changes in the absorbance and Bilirubin fraction were compared with those in Bilirubin- human serum albumin (HSA) and Bilirubin-rat albumin solutions. The λmax decreased with light irradiation. The mean production rate of cycloBilirubin IXα was 1.98, 199 and 0.76 × 10−2/min in rhesus monkey serum, HSA and rat albumin, respectively. There was no significant difference between rhesus monkey serum and HSA. The (ZE)-Bilirubin IXα/(ZZ)-Bilirubin IXα ratio was 0.33, 0.45, and 0.10, respectively, differing significantly among the groups. The (EZ)-Bilirubin IXα/(ZZ)-Bilirubin IXα ratio was 0.020, 0.010, and 0.062, respectively, with no significant difference between rhesus monkey serum and HSA. The production rate of (EZ)-cycloBilirubin XIIIα(= (ZE)-cycloBilirubin XIIIα) was 0.73, 1.60, and 0.51 × 10−2/min, respectively, with differing significantly among the groups. The (EZ)-Bilirubin IIIα/(ZZ)-Bilirubin IIIα ratio was significantly different among the groups at 0.20, 0.38, and 0.15, respectively. This is the first report demonstrating the photoisomerization of Bilirubin in rhesus monkey serum and the animal with the same cycloBilirubin production rate as HSA.Rhesus monkeys may be used as an animal model for neonatal hyperBilirubinemia in humans to evaluate the efficacy of phototherapy.
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Reactivity of Bilirubin photoisomers on the measurement of direct Bilirubin using vanadic acid method
Annals of clinical biochemistry, 2017Co-Authors: Hitoshi Okada, Susumu Itoh, Shohei Kawamoto, Miyo Ozaki, Takashi KusakaAbstract:Objective Investigation of the reactivity of fractions of Bilirubin photoisomers with the vanadic acid oxidation method. Methods Bilirubin photoisomers were prepared by irradiating a Bilirubin/human serum albumin solution with blue light emitting diode. Direct Bilirubin and Bilirubin fractions were measured using the vanadic acid oxidation method and high-performance liquid chromatography in the sample before and after irradiation. Results Direct Bilirubin was increased in the solution containing Bilirubin photoisomers. ( EE)-/( EZ) -cycloBilirubin-IXα and ( ZE)-/( EZ)-Bilirubin-IXα completely disappeared after the addition of vanadic acid. Conclusion Bilirubin photoisomers reacted as direct Bilirubin in the vanadic acid oxidation method.
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Influence of Bilirubin photoisomers on unbound Bilirubin measurement in clinical settings.
Annals of clinical biochemistry, 2012Co-Authors: Hitoshi Okada, Kosuke Koyano, Saneyuki Yasuda, Takashi Kusaka, Kaori Koyano, Jun Kunikata, Takashi Iwase, Kenichi Isobe, Susumu ItohAbstract:Measured unbound Bilirubin concentration is influenced by Bilirubin photoisomers. Bilirubin photoisomers are produced even with only a slight light exposure, and clinical samples are inevitably exposed to light. The objective of the study was to evaluate the influence of Bilirubin photoisomers on the measurement of unbound Bilirubin using serum of jaundiced neonates during blue light phototherapy. Five neonates treated with phototherapy for hyperBilirubinaemia were enrolled. The samples were taken 12 h after initiation of phototherapy. Samples were processed by irradiation with blue light, by indoor ceiling light, by both blue light and indoor ceiling light or shaded. Bilirubin subfractions, total Bilirubin and unbound Bilirubin were measured. Compared with the non-irradiated samples, the (EZ)-cycloBilirubin concentration and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the blue light-irradiated samples, the (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the indoor ceiling light-irradiated samples, and the (EZ)-cycloBilirubin, (EZ)-Bilirubin and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the samples irradiated with both lights. No change was noted in unbound Bilirubin in any group. We consider that changes in Bilirubin photoisomers induced by light exposure during clinical practice do not influence the measured unbound Bilirubin concentration.
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Influence of Bilirubin photoisomers on unbound Bilirubin measurement in clinical settings
Annals of Clinical Biochemistry: International Journal of Laboratory Medicine, 2012Co-Authors: Hitoshi Okada, Kosuke Koyano, Saneyuki Yasuda, Takashi Kusaka, Kaori Koyano, Jun Kunikata, Takashi Iwase, Kenichi Isobe, Susumu ItohAbstract:BackgroundMeasured unbound Bilirubin concentration is influenced by Bilirubin photoisomers. Bilirubin photoisomers are produced even with only a slight light exposure, and clinical samples are inevitably exposed to light. The objective of the study was to evaluate the influence of Bilirubin photoisomers on the measurement of unbound Bilirubin using serum of jaundiced neonates during blue light phototherapy.MethodsFive neonates treated with phototherapy for hyperBilirubinaemia were enrolled. The samples were taken 12 h after initiation of phototherapy. Samples were processed by irradiation with blue light, by indoor ceiling light, by both blue light and indoor ceiling light or shaded. Bilirubin subfractions, total Bilirubin and unbound Bilirubin were measured.ResultsCompared with the non-irradiated samples, the (EZ)-cycloBilirubin concentration and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the blue light-irradiated samples, the (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increase...
Charles E. Ahlfors - One of the best experts on this subject based on the ideXlab platform.
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the Bilirubin binding panel a henderson hasselbalch approach to neonatal hyperBilirubinemia
Pediatrics, 2016Co-Authors: Charles E. AhlforsAbstract:Poor plasma Bilirubin binding increases the risk of Bilirubin neurotoxicity in newborns with hyperBilirubinemia. New laboratory tests may soon make it possible to obtain a complete Bilirubin binding panel when evaluating these babies. The 3 measured components of the panel are the plasma total Bilirubin concentration (BTotal), which is currently used to guide clinical care; the Bilirubin binding capacity (BBC); and the concentration of non-albumin bound or free Bilirubin (BFree). The fourth component is the Bilirubin-albumin equilibrium dissociation constant, KD, which is calculated from BTotal, BBC, and BFree The Bilirubin binding panel is comparable to the panel of components used in the Henderson-Hasselbalch approach to acid-base assessment. Bilirubin binding population parameters (not prospective studies to determine whether the new Bilirubin binding panel components are better predictors of Bilirubin neurotoxicity than BTotal) are needed to expedite the clinical use of Bilirubin binding. At any BTotal, the BFree and the relative risk of Bilirubin neurotoxicity increase as the KD/BBC ratio increases (ie, Bilirubin binding worsens). Comparing the KD/BBC ratio of newborns with BTotal of concern with that typical for the population helps determine whether the risk of Bilirubin neurotoxicity varies significantly from the inherent risk at that BTotal Furthermore, the Bilirubin binding panel individualizes care because it helps to determine how aggressive intervention should be at any BTotal, irrespective of whether it is above or below established BTotal guidelines. The Bilirubin binding panel may reduce anxiety, costs, unnecessary treatment, and the likelihood of undetected Bilirubin neurotoxicity.
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Evaluation of a Model for Brain Bilirubin Uptake in Jaundiced Newborns
Pediatric Research, 2005Co-Authors: Charles E. Ahlfors, Anne E ParkerAbstract:A model for brain Bilirubin uptake (BBU) predicts that BBU in jaundiced newborns typically depends on the plasma total Bilirubin concentration (TBC) and the Bilirubin-albumin dissociation rate constant (k_1) rather than the unbound Bilirubin (B_f). The model's validity was tested by 1) evaluating its requirement that k_3 >>> k_2, where k_3 and k_2 are the rate constants for BBU and B_f-albumin association, respectively, and 2) determining whether the calculated BBU is ≤5% of the Bilirubin production rate, the approximate BBU expected if brain Bilirubin levels are
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Unbound Bilirubin in a term newborn with kernicterus.
PEDIATRICS, 2003Co-Authors: Charles E. Ahlfors, Oded HerbsmanAbstract:In premature newborns, Bilirubin-induced changes in the auditory brainstem response (ABR) begin at unbound (nonalbumin-bound or “free”) Bilirubin levels above .5 μg/dL,1 and kernicterus becomes likely at levels between ∼1 and 1.5 μg/dL (.017-.026 μmol/L).2,3 In term newborns, however, unbound Bilirubin levels between .9 and 2 μg/dL, which would be associated kernicterus in premature newborns, produce only subtle, reversible changes in ABR wave latency and amplitude.4 Although the unbound Bilirubin levels associated with kernicterus in term newborns are unknown, they clearly are greater than the levels associated with kernicterus in premature infants. This indicates that, as with the total Bilirubin and total Bilirubin/albumin ratio, the unbound Bilirubin levels associated with kernicterus increase as birth weight and gestation increase.1,5 We have been using a Food & Drug Administration-approved method6 for measuring unbound Bilirubin in jaundiced newborns as an adjunct to their clinical care since 1998. We use a weight-based unbound Bilirubin reference value of 1.3 μg/dL/kg (the level of unbound Bilirubin at which exchange transfusion should be considered) up to a maximum of 4 μg/dL to accommodate the need to increase the reference unbound Bilirubin as birth weight increases and to incorporate the solubility limits of unbound Bilirubin at ph 7.4 (∼4 μg/dL) into the reference criteria.1–5,7–9 We recently encountered a term, jaundiced newborn that developed acute shock and died, apparently from kernicterus. This report describes the infant’s clinical course and Bilirubin-albumin binding data. This case provides insight into the levels of unbound Bilirubin associated with kernicterus in term infants as well as the acute changes in distribution of the Bilirubin load (miscible Bilirubin pool) between the tissues and the vascular space following the onset of kernicterus. A 110-hour-old (4.5-day-old) Nigerian male newborn presented to … Reprint requests to (C.E.A.) Division of Neonatology, Department of Pediatrics, California Pacific Medical Center, 3850 California St, San Francisco, CA 94118. E-mail: ligand{at}centurytel.net
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Bilirubin-albumin binding and free Bilirubin.
Journal of Perinatology, 2001Co-Authors: Charles E. AhlforsAbstract:The relevance of plasma Bilirubin-albumin binding and, in particular, the nonalbumin-bound or "free" Bilirubin concentration to neonatal Bilirubin toxicity is controversial. The pivotal role that "free" Bilirubin played in the Bilirubin toxicity that occurred following administration of sulfisoxazole or benzyl alcohol to jaundiced newborns, and the correlation of "free" Bilirubin with Bilirubin-induced changes in the auditory brainstem response are strong support for measuring "free" Bilirubin when evaluating neonatal jaundice. Reliable methods for measuring "free Bilirubin" are available, and population reference values are needed to help determine its proper clinical use.
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Unbound Bilirubin associated with kernicterus: a historical approach.
The Journal of pediatrics, 2000Co-Authors: Charles E. AhlforsAbstract:Abstract Objective: To determine the unbound Bilirubin concentration (UBC) associated with kernicterus with the use of clinical data from clusters of kernicterus after sulfisoxazole and benzyl alcohol administration. Design: Sulfisoxazole at 12 mg/dL and benzoate at 10 mmol/L are associated with kernicterus at total Bilirubins near 12 and 10 mg/dL, respectively. The concurrent UBC was estimated by first measuring the drug-induced increases in UBC in plasma and artificial sera (peroxidase-diazo method). The increases were then applied to baseline UBC, determined by linear regression analysis of binding data (peroxidase method) from 86 newborns, at total Bilirubins of 12 mg/dL for sulfisoxazole and 10 mg/dL for benzoate. Sensitivity and specificity were determined with existing data. Results: Sulfisoxazole and benzoate increased UBC in artificial sera 2.1-fold and 4.1-fold, respectively, and in plasma (sulfisoxazole) 2.4-fold. Benzoate would increase baseline UBC from 0.29 to 1.19 μg/dL and sulfisoxazole from 0.36 to 0.86 μg/dL. The sensitivity and specificity of a UBC of 0.86 μg/dL for predicting kernicterus are 79% and 92% and for 1.19 μg/dL, 50% and 98%, respectively. Conclusion: Historic data predict that the unbound Bilirubin above which kernicterus becomes likely lies between 0.86 and 1.19 μg/dL, in good agreement with existing information. (J Pediatr 2000;137:540-4)
Susumu Itoh - One of the best experts on this subject based on the ideXlab platform.
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Bilirubin photoisomers in rhesus monkey serum
Journal of photochemistry and photobiology. B Biology, 2018Co-Authors: Hitoshi Okada, Susumu Itoh, Kohichiroh Nii, Masashiro Sugino, Noriko Fuke, Kosuke Koyano, Saneyuki Yasuda, Takashi KusakaAbstract:Abstract As rhesus monkeys exhibit physiological jaundice during the neonatal period, we used rhesus monkey serum to examine changes in Bilirubin photoisomers. Bilirubin-rhesus monkey serum solution was irradiated with blue light-emitting diode, and changes in the absorbance and Bilirubin fraction were compared with those in Bilirubin- human serum albumin (HSA) and Bilirubin-rat albumin solutions. The λmax decreased with light irradiation. The mean production rate of cycloBilirubin IXα was 1.98, 199 and 0.76 × 10−2/min in rhesus monkey serum, HSA and rat albumin, respectively. There was no significant difference between rhesus monkey serum and HSA. The (ZE)-Bilirubin IXα/(ZZ)-Bilirubin IXα ratio was 0.33, 0.45, and 0.10, respectively, differing significantly among the groups. The (EZ)-Bilirubin IXα/(ZZ)-Bilirubin IXα ratio was 0.020, 0.010, and 0.062, respectively, with no significant difference between rhesus monkey serum and HSA. The production rate of (EZ)-cycloBilirubin XIIIα(= (ZE)-cycloBilirubin XIIIα) was 0.73, 1.60, and 0.51 × 10−2/min, respectively, with differing significantly among the groups. The (EZ)-Bilirubin IIIα/(ZZ)-Bilirubin IIIα ratio was significantly different among the groups at 0.20, 0.38, and 0.15, respectively. This is the first report demonstrating the photoisomerization of Bilirubin in rhesus monkey serum and the animal with the same cycloBilirubin production rate as HSA.Rhesus monkeys may be used as an animal model for neonatal hyperBilirubinemia in humans to evaluate the efficacy of phototherapy.
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Reactivity of Bilirubin photoisomers on the measurement of direct Bilirubin using vanadic acid method
Annals of clinical biochemistry, 2017Co-Authors: Hitoshi Okada, Susumu Itoh, Shohei Kawamoto, Miyo Ozaki, Takashi KusakaAbstract:Objective Investigation of the reactivity of fractions of Bilirubin photoisomers with the vanadic acid oxidation method. Methods Bilirubin photoisomers were prepared by irradiating a Bilirubin/human serum albumin solution with blue light emitting diode. Direct Bilirubin and Bilirubin fractions were measured using the vanadic acid oxidation method and high-performance liquid chromatography in the sample before and after irradiation. Results Direct Bilirubin was increased in the solution containing Bilirubin photoisomers. ( EE)-/( EZ) -cycloBilirubin-IXα and ( ZE)-/( EZ)-Bilirubin-IXα completely disappeared after the addition of vanadic acid. Conclusion Bilirubin photoisomers reacted as direct Bilirubin in the vanadic acid oxidation method.
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Influence of Bilirubin photoisomers on unbound Bilirubin measurement in clinical settings.
Annals of clinical biochemistry, 2012Co-Authors: Hitoshi Okada, Kosuke Koyano, Saneyuki Yasuda, Takashi Kusaka, Kaori Koyano, Jun Kunikata, Takashi Iwase, Kenichi Isobe, Susumu ItohAbstract:Measured unbound Bilirubin concentration is influenced by Bilirubin photoisomers. Bilirubin photoisomers are produced even with only a slight light exposure, and clinical samples are inevitably exposed to light. The objective of the study was to evaluate the influence of Bilirubin photoisomers on the measurement of unbound Bilirubin using serum of jaundiced neonates during blue light phototherapy. Five neonates treated with phototherapy for hyperBilirubinaemia were enrolled. The samples were taken 12 h after initiation of phototherapy. Samples were processed by irradiation with blue light, by indoor ceiling light, by both blue light and indoor ceiling light or shaded. Bilirubin subfractions, total Bilirubin and unbound Bilirubin were measured. Compared with the non-irradiated samples, the (EZ)-cycloBilirubin concentration and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the blue light-irradiated samples, the (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the indoor ceiling light-irradiated samples, and the (EZ)-cycloBilirubin, (EZ)-Bilirubin and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the samples irradiated with both lights. No change was noted in unbound Bilirubin in any group. We consider that changes in Bilirubin photoisomers induced by light exposure during clinical practice do not influence the measured unbound Bilirubin concentration.
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Influence of Bilirubin photoisomers on unbound Bilirubin measurement in clinical settings
Annals of Clinical Biochemistry: International Journal of Laboratory Medicine, 2012Co-Authors: Hitoshi Okada, Kosuke Koyano, Saneyuki Yasuda, Takashi Kusaka, Kaori Koyano, Jun Kunikata, Takashi Iwase, Kenichi Isobe, Susumu ItohAbstract:BackgroundMeasured unbound Bilirubin concentration is influenced by Bilirubin photoisomers. Bilirubin photoisomers are produced even with only a slight light exposure, and clinical samples are inevitably exposed to light. The objective of the study was to evaluate the influence of Bilirubin photoisomers on the measurement of unbound Bilirubin using serum of jaundiced neonates during blue light phototherapy.MethodsFive neonates treated with phototherapy for hyperBilirubinaemia were enrolled. The samples were taken 12 h after initiation of phototherapy. Samples were processed by irradiation with blue light, by indoor ceiling light, by both blue light and indoor ceiling light or shaded. Bilirubin subfractions, total Bilirubin and unbound Bilirubin were measured.ResultsCompared with the non-irradiated samples, the (EZ)-cycloBilirubin concentration and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the blue light-irradiated samples, the (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increase...
Kosuke Koyano - One of the best experts on this subject based on the ideXlab platform.
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Bilirubin photoisomers in rhesus monkey serum
Journal of photochemistry and photobiology. B Biology, 2018Co-Authors: Hitoshi Okada, Susumu Itoh, Kohichiroh Nii, Masashiro Sugino, Noriko Fuke, Kosuke Koyano, Saneyuki Yasuda, Takashi KusakaAbstract:Abstract As rhesus monkeys exhibit physiological jaundice during the neonatal period, we used rhesus monkey serum to examine changes in Bilirubin photoisomers. Bilirubin-rhesus monkey serum solution was irradiated with blue light-emitting diode, and changes in the absorbance and Bilirubin fraction were compared with those in Bilirubin- human serum albumin (HSA) and Bilirubin-rat albumin solutions. The λmax decreased with light irradiation. The mean production rate of cycloBilirubin IXα was 1.98, 199 and 0.76 × 10−2/min in rhesus monkey serum, HSA and rat albumin, respectively. There was no significant difference between rhesus monkey serum and HSA. The (ZE)-Bilirubin IXα/(ZZ)-Bilirubin IXα ratio was 0.33, 0.45, and 0.10, respectively, differing significantly among the groups. The (EZ)-Bilirubin IXα/(ZZ)-Bilirubin IXα ratio was 0.020, 0.010, and 0.062, respectively, with no significant difference between rhesus monkey serum and HSA. The production rate of (EZ)-cycloBilirubin XIIIα(= (ZE)-cycloBilirubin XIIIα) was 0.73, 1.60, and 0.51 × 10−2/min, respectively, with differing significantly among the groups. The (EZ)-Bilirubin IIIα/(ZZ)-Bilirubin IIIα ratio was significantly different among the groups at 0.20, 0.38, and 0.15, respectively. This is the first report demonstrating the photoisomerization of Bilirubin in rhesus monkey serum and the animal with the same cycloBilirubin production rate as HSA.Rhesus monkeys may be used as an animal model for neonatal hyperBilirubinemia in humans to evaluate the efficacy of phototherapy.
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Influence of Bilirubin photoisomers on unbound Bilirubin measurement in clinical settings.
Annals of clinical biochemistry, 2012Co-Authors: Hitoshi Okada, Kosuke Koyano, Saneyuki Yasuda, Takashi Kusaka, Kaori Koyano, Jun Kunikata, Takashi Iwase, Kenichi Isobe, Susumu ItohAbstract:Measured unbound Bilirubin concentration is influenced by Bilirubin photoisomers. Bilirubin photoisomers are produced even with only a slight light exposure, and clinical samples are inevitably exposed to light. The objective of the study was to evaluate the influence of Bilirubin photoisomers on the measurement of unbound Bilirubin using serum of jaundiced neonates during blue light phototherapy. Five neonates treated with phototherapy for hyperBilirubinaemia were enrolled. The samples were taken 12 h after initiation of phototherapy. Samples were processed by irradiation with blue light, by indoor ceiling light, by both blue light and indoor ceiling light or shaded. Bilirubin subfractions, total Bilirubin and unbound Bilirubin were measured. Compared with the non-irradiated samples, the (EZ)-cycloBilirubin concentration and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the blue light-irradiated samples, the (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the indoor ceiling light-irradiated samples, and the (EZ)-cycloBilirubin, (EZ)-Bilirubin and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the samples irradiated with both lights. No change was noted in unbound Bilirubin in any group. We consider that changes in Bilirubin photoisomers induced by light exposure during clinical practice do not influence the measured unbound Bilirubin concentration.
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Influence of Bilirubin photoisomers on unbound Bilirubin measurement in clinical settings
Annals of Clinical Biochemistry: International Journal of Laboratory Medicine, 2012Co-Authors: Hitoshi Okada, Kosuke Koyano, Saneyuki Yasuda, Takashi Kusaka, Kaori Koyano, Jun Kunikata, Takashi Iwase, Kenichi Isobe, Susumu ItohAbstract:BackgroundMeasured unbound Bilirubin concentration is influenced by Bilirubin photoisomers. Bilirubin photoisomers are produced even with only a slight light exposure, and clinical samples are inevitably exposed to light. The objective of the study was to evaluate the influence of Bilirubin photoisomers on the measurement of unbound Bilirubin using serum of jaundiced neonates during blue light phototherapy.MethodsFive neonates treated with phototherapy for hyperBilirubinaemia were enrolled. The samples were taken 12 h after initiation of phototherapy. Samples were processed by irradiation with blue light, by indoor ceiling light, by both blue light and indoor ceiling light or shaded. Bilirubin subfractions, total Bilirubin and unbound Bilirubin were measured.ResultsCompared with the non-irradiated samples, the (EZ)-cycloBilirubin concentration and (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increased in the blue light-irradiated samples, the (ZE)-Bilirubin/(ZZ)-Bilirubin ratio significantly increase...
